CA2224378A1 - Adhesives containing electrically conductive agents - Google Patents

Abstract

Pressure sensitive adhesives and heat activatable adhesives that are the reaction product of an acrylic acid ester of a monohydric alcohol whose homopolymer has a Tg less than 0 ~C; a non-polar ethylenically unsaturated monomer whose homopolymer has a solubility parameter of no greater than 10.50 and a Tg greater than 15 ~C; 0-5 parts by weight of a polar ethylenically unsaturated monomer whose homopolymer has a solubility parameter of greater than 10.50 and a Tg greater than 15 ~C; and an electrically conductive agent.

Description

CA 02224378 l997-l2-lO

W O 97/03144 PCT~US96/08369 5 ADHESIVES CONTAIN~!IG ELECTRICALLY CONDUCTIVE AGENTS

Background of the Invention Field of the Invention This invention relates to adhesives co~ g electrically conductive agents.

Description of the Back~round Art Acrylate pressure sensitive adhesives are well known in the art. Many of these adhesives are copolymers of an alkyl ester of acrylic acid and a minor portion of a polar co-monomer. Due to the presence of the polar co-monomer these adhesives generally do not adhere well to low energy and oily surfaces (e.g., surfaces having a critical surface tension of wetting of no greater than about 35 dynes/cm). Although adhesion can be improved through addition of a tackifier, the degree of improvement is limited because most commercially available tackifiers are not miscible in the polar monomer-containing adhesive.
Acrylate heat activatable adhesives and the use of electrically conductive agents in adhesives are also known. However, the present invention provides superior adhesives ~,o~ .;llg electrically conductive agents.

Summary of the Invention In one aspect, the invention features a pressure sensitive adhesive that in~lndçs the reaction product of starting materials comprising:
(a) 25-97 parts by weight of an acrylic acid ester of a monohydric alcohol whose homopolymer has a Tg less than 0~C;

(b) 3-75 parts by weight of a non-polar ethylenically unsaturated ..,ono...er whose homopolyrner has a solubility pa~ er of no greater than 10.50 and a Tg greaterthan 15~C;
(c) 0-5 parts by weight of a polar ethylenically unsaturated monomer whose homopolymer has a solubility pal ~mcter of greater than 10.50 and a Tg greater than 15~C; and (d) an effective amount of an electrically conductive agent s~le~led from r~ickel, silver, copper, or gold particles. The relative amounts of the acrylic acid ester, the non-polar ethylenically unsaturated monomer, and the polar ethylenically unsaturated monomer are chosen such that the 90~ peel adhesion of the ~res:iul ~sensitive adhesive to a polypropylene surface is at least 2 Ibs/0.5 in. after a 72 hour dwell at room temperature as measured according to Test Procedure B-I, infra.
In another aspect, the invention provides a heat activatable adhesive comprising the reaction product of starting materials comprising:
(a) 25-97 parts by weight of an acrylic acid ester of a monohydric alcohol whose homopolymer has a Tg less than 0~C;
(b) 3-75 parts by weight of a non-polar ethylenically unsaturated monomer whose homopolymer has a solubility parameter of no greater than 10.50 and a Tg greater than 15~C;
(c) 0-5 parts by weight of a polar ethylenically unsaturated monomer whose homopolymer has a solubility parameter of greater than 10.50 and a Tg greater than 15~C; and (d) an effective amount of an electrically conductive agent; wherein said adhesive is çc~enti~lly nontacky at 20C and has a Tg of 30C or greater. In otheremborlim~nt~ the adhesive has a Tg of 35C or greater; 40C or g.~atel, and 50C
or greater.
In another aspect, the invention features a pressure sensitive adhesive that includes the polymerization product of:
(a) 25-97 parts by weight of an acrylic acid ester of a monohydric alcohol 30 whose homopolymer has a Tg less than 0~C;

W O 97/03144 PCT~US96/08369 (b) 3-75 parts by weight of a non-polar ethylenically unsaturated monomer whose homopolymer has a solubility pa- ~."t;ler of no greater than 10.50 and a Tg greater than 15~C; and (c) 0-5 parts by weight of a polar ethylenically unsaturated monomPr whose 5 homopolymer has a solubility palalneLe~ of greater than 10.50 and a Tg greater than 15~C. The relative ~."o~...lc ofthe acrylic acid ester, the non-polar ethylenically unsaturated monomer, and the polar ethylenically unsaturated monomer are chosen such that the 90~ peel adhesion of the pressure sensitive adhesive to a surface provided with 1.5 + 0.25 mg/in2 oil is greater than zero after a 10 second dwell at room temperature as measured according to Test Procedure B-II, infia.
In another aspect, the invention features a pressure sensitive adhesive that inf~
(a) the polymerization product of:
(i) 25-98 parts by weight of an acrylic acid ester of a monohydric alcohol whose hol.,opolymer has a Tg less than 0~C;
(ii) 2-75 parts by weight of a non-polar ethylenically unsaturated monomer whose homopolymer has a solubility parameter of no greater than 10.50 and a Tg greaterthan 15~C;
(iii) 0-5 parts by weight of a polar ethylenically unsaturated monomer whose homopolymer has a solubility parameter of greater than 10.50 and a Tg greater than 1 5~C; and (b) at least one tackifier that is miscible in the polymerization product at room te---~ re.
By "miscible" it is meant that the final pressure sensitive adhesive does not exhibit macroscopic phase separation as evidenced by optical clarity at room t~ re.
In one pl ~re. . ed embodiment, the relative amounts of the acrylic acid ester, non-polar ethylenically unsaturated monomer, and polar ethylenically unsaturatedmonomer are chosen such that the 90~ peel adhesion of the pressure sensitive adhesive to a polypropylene surface is at least 2 Ibs/0.5 in. after a 72 hour dwell at room temperature as measured according to Test Procedure B l-m, infra.

W Og7/03144 PcTiU~_.S/~D~r9 In another pl erG" ed embo~im~nt, the relative amounts of the acrylic acid ester, non-polar ethylenically unsaturated monomer, and polar ethylenically unsalu,~led lllonolll.;r are chosen such that the 90~ peel adhesion of the pressure sensitive adhesive to a surface provided with 1.5 + 0.25 mg/in2 of oil is greater than r 5 zero after a 10 second dwell at room te"~l,G~al~lre as measured according to Test Procedure B2-m, infra.
The solubility parameter referred to herein is c~lc~ ted accol~;li,~ to the technique desc,il,ed in Fedors, Polym. Eng. and Sci., 14:147 (1974). A monomer whose homopolymer has a solubility palalllGler of greater than 10.50 when measured according to the Fedors technique is referred to herein as a polar monomer, whereas a monomer whose homopolymer has a solubility parameter of 10.50 or less when measured according to the Fedors technique is referred to herein as a non-polar monomer.
The invention provides pressure sensitive adhesives and tackified pressure sensitive adhesives which, by virtue of incorporating a non-polar ethylenically unsaturated monomer and limiting the polar monomer content to no more than 5 parts, exhibit good adhesion to low energy (e.g., plastics such as polyolefin plastics) surfaces and oily surfaces. The adhesives exhibit good adhesion to high energy surfaces such as stainless steel as well. Because the non-polar monomer reduces the polarity of the adhesive, commercially available tackifiers (many of which have low polarity themselves) are miscible in the adhesives and thus may be used. Thus, rather than tailoring the tackifier to make it miscible with the acrylate polymer, the invention tailors the properties of the acrylate polymer to make it miscible with the tackifier.
The adhesives are less toxic than, e.g., adhesives cont~inins~ polar heteroatom acrylates. The adhesives further exhibit good shear p~,pe, lies both at low and high temperatures, particularly when a small amount (no more than 5 parts) of a polar co-monomer is included.
The adhesives offer the further advantage of reduced sensitivity to moisture and reduced tendency to corrode metals such as copper relative to pressure sensitive adhesives co..l~ g higher amounts of polar co-monomers. Furthermore, W O 97/03144 PCT~US96/08369 the adhesives interact to a lesser extent with polar additives and, in some cases, increase the solubility of non-polar additives co,l,pal ed to pressure sensitiveadhesives co~ ; - -;- .g higher ~nlounts of polar co-m- --c,- - -~
Other features and advantages of the invention will be app~ t;lll from the 5 following description of the pi ~re" ~d embodiments thereof, and from the claims.

Description of the Pl ~rt " ~d Embo~iiment~
One class of p,e~u~e sensitive adhesives acco~-ling to this invention displays 10 good adhesion to both low energy surfaces such as polypropylene and high energy surfaces such as stainless steel. In both cases, the 90~ peel ~l~t;nglll after a 72 hour dwell is at least 2 Ibs/0.5 in., pl-er~lably at least 2.5 Ibs/0.5 in., and more preferably at least 3 Ibs/0.5 in. measured accoldillg to Test Procedure B-I, infra. The adhesives also display good cohesive strength properties as measured by the shear 15 ~ glh. Preferably, the shear strength at both room temperature and 70~C is greater than 50 min~lte~, more preferably greater than 1,000 minlltes, and even more p, erel~bly greater than 10,000 minutes measured according to Test Procedure C-I, infra.
A second class of pressure sensitive adhesives according to this invention 20 displays good adhesion to oily surfaces (e.g., oily metal surfaces). Examples of oily surfaces include surfaces provided with mineral oil, emulsion oils, peanut oil, motor oil (e.g., 5W-30), WD40, and Ferricote 61 A US (Quaker Chemical Co.) (a common protectant for cold rolled steel). The 90~ peel adhesion to a surface provided with 1.5 ~ 0.25 mg/in2 oil after a 10 second dwell at room temperature is 25 greater than zero, plefel~bly at least 2 oz./0.5 in., and more preferably at least 4 ozlO.5 in. measured according to Test Procedure B-II, infra. After a 1 minute dwell, the adhesion preferably builds to at least 5 oz/0.5 in. and more preferably to at least 10 oz/0.5 in. measured according to Test Procedure B-II, infra. The adhesives also display good cohesive strength properties as measured by the shear 30 strength. I'I~Çt;l~bly, the shear strength at both room temperature and 70~C is -CA 02224378 l997-l2-lO

W O 97/03144 rCT~US96/08369 greater than S0 mimltçs, more preferably greater than 300 mimltçe, and even more~rt;rc,~bly greater than 600 ...;....les The t~ ifiYl pressure sensitive adhesives of this invention display good adhesion to both low energy surfaces such as polypropylene, high energy surfacesS such as s~in~s steel, and oily surfaces (e.g., oily metal). E~ ,les of oily ~ cç5 include surfaces provided with mineral oil, emulsion oils, peanut oil, motor oil (e.g., 5W-30), WD40, and Ferricote 61 A US (Quaker Chemical Co.) (a common ploLe~ for cold rolled steel).
The 90~ peel adhesion to polypropylene or to steel after a 72 hour dwell at 10 room temperature is at least 2 Ibs/O.S in., preferably at least 3 Ibs/O.S in., and more preferably at least 4 Ibs/O.S in. measured according to Test Procedure B l-III, infra.
The 90~ peel adhesion to a surface provided with 1.5 ~ 0 25 mg/in2 of oil after a 10 second dwell at room lell-pel ~ re is greater than zero, p- ere- ~bly at least 2 oz/O.S
in., and more plcrc~bly at least 4 oz./O S in measured according to Test Procedure 15 B2-III, infra. After a 1 minute dwell, the adhesion preferably builds to at least 5 oz/O S in. and more pl~;Ç~ bly to at least 10 oz/O S in measured according to Test Procedure B2-III, infra.
The tackified adhesives also display good cohesive strength properties as measured by the shear ~ll cngLll. Preferably, the shear strength at both room 20 temperature and 70~C is greater than S0 minutes, more preferably greater than1,000 mimltec and even more preferably greater than 10,000 minutes measured according to Test Procedures C l-III and C2-III, infra The plopellies ofthe pressure sensitive adhesives and tackified pressure sensitive adhesives according to the invention are achieved by controlling the 25 monomeric composition to achieve the appl Opl iate polarity (as measured by the solubility parameter of the homopolymers of the individual monomers determined according to the Fedors technique) and rheological properties (Tg as measured by the 1 radian/second tan delta maximum temperature of the adhesive polymer).
The ability to incorporate a tackifier increases the value of the peel ~LIcngl}
30 beyond what it would be in the absence of the tackifier. The tackifier also increases"formulation freedom," i e., the ability to adjust the properties ofthe CA 02224378 l997-l2-lO

W O 97/03144 PCTrUS96/08369 adhesives for particular app1ications by introducing another variable, namely, the tackifier.
A list of several C01lllll0l1 monomers and their respective Fedors' solubility pa,~ulwlel~ is shown in Table 1. Table 1 is subdivided into four sections: low Tg S acrylate ...ol-o..~e~:j, high Tg acrylate monomers, high Tg meth~s~ylate monomers, and vinyl l..onoll..,.:,.

TABLE 1: FEDORS' SOLUBILITY PARAMETERS
Repeat Unit Solubility P~l.lcler (caVcm3)0 5 Octadecyl acrylate (ODA) 8.99 Lauryl acrylate (LA) 9.15 Iso-octyl acrylate (IOA) a.

2-ethylhexyl acrylate (2-EHA) 9.",~
Butyl acrylate (BA) 9.~
Propyl acrylate (PA) 9.95 Ethyl acrylate (EA) 10.20 3,3,5 trimethylcyclohexyl acrylate 9.35 (T~CA) Iso-~ornyl acryl~te (IBA) 9.71 Cyc ohexyl acry ate (CHA) 10.: 6 :~-octyl acrJlam de (NOA) 10.33 'etrahydrolllrfuryl acrylate (THFA) 10.~3 Methyl acry ate (MA) 10. ' 6 G ycidyl acrylate (GA) 11.: 2 2?henoxyethylacrylate (2-PhEA) 11 .79 I~-vnylcaprolactam(NVC) 12.10 ~,I~;,-Dimethylacrylamide (DMA) 12.32 ~-v nyl-2-pyrrolidone (NVP) 13.38 Acrylic Acid (AA) 14.04 ~ethylmethacrylate (MMA) 9.93 Ethylm.o,th~r.rylate (EMA) 9.72 ?ropylme~h~c.rylate (PMA) 9.57 Vinyl Acetate 10.56 Styrene 1 1.87 The rheological character of the adhesive polymer can be partially but 5 usefully described by the Tg as measured by the 1 radian/second tan delta maximum tt~ .el aL~Ire. In the case of adhesives de~igned for adhesion to low energy surfaces, it is preferable for the Tg as measured by the 1 radian/second tan delta maximum of the polymer to have a value between -45~C and 15~C, more preferably between -25~C and 0~C, and even more plerel~bly between -20~C and -5~C. In the case of 10 adhesives decigned for adhesion to oily surfaces, it is preferable for the Tg as measured by the 1 radian/second tan delta maximum temperature of the polymer to W O 97/03144 PCT/u~r5~
have a value belween -45~C and 15~C, more pl~;;r~lably between -35~C and 0~C, and even more plerelably between -30~C and -5~C.
In both cases, the adhesives accoldil~g to the invention having the requisite polarity and rheological plopelLies contain 25-97 parts (more ple~,ably 40-85 5 parts) of an acrylic acid ester whose homopolymer has a Tg less than 0~C (more plt;r~ bly less than -20~C), 3-75 parts (more preferably 15-60 parts) of a non-polar ethylenically unsaturated monomer whose homopolymer has a Tg greater than 15~C, and 0-5 parts (more preferably 0-3 parts) of a polar ethylenically ~lnsaLu~led monomer whose homopolymer has a Tg greater than 15~C.
In the case of tackified pressure sensitive adhesives, it is pi crel ablc for the 1 radian/second tan delta maximum telll~t;laL-Ire of the polymer to have a value between -45~C and 15~C, more preferably between -25~C and 5~C, and even more preferably between -20~C and 0~C. The tackified adhesives according to the invention having the requisite polarity and rheological properties contain 25-9815 parts (more preferably 70-97 parts) of an acrylic acid ester whose homopolymer has a Tg less than 0~C (more preferably less than -20~C), 2-75 parts (more p~:r~bly 3-30 parts) of a non-polar ethylenically unsaturated monomer whose homopolymer has a Tg greater than 15~C, 0-S parts (more preferably 0-3 parts) of a polar ethylenically unsaturated monomer whose homopolymer has a Tg greater than 20 15~C, and one or more tackifiers.
In all cases, the acrylic acid ester is a monofunctional acrylic ester of a monohydric alcohol having from about 4 to about 18 carbon atoms in the alcohol moiety whose homopolymer has a Tg less than 0~C. Included in this class of acrylic acid esters are isooctyl acrylate, 2-ethylhexyl acrylate, isononyl acrylate, isodecyl 25 acrylate, decyl acrylate, lauryl acrylate, hexyl acrylate, butyl acrylate, and octadecyl acrylate, or combinations thereof. In the case of octadecyl acrylate, the amount is chosen such that side chain cryst~lli7~tion does not occur at room temperature.
The non-polar ethylenically-unsaturated monomer is a monomer whose homopolymer has a solubility parameter as measured by the Fedors method of not greater than 10.50 and a Tg greater than 15~C. In a pr~relled embodiment, the CA 02224378 l997-l2-lO

W O 97/03144 PCTrUS96/08369 non-polar ethylenically-unsaturated monomer is a monomer whose homopolymer has a solubility p~ ~neler as measured by the Fedors method of not greater than 10.3, more plcrel~bly not greater than 9.9. The non-polar nature ofthis monomer illl~)l u~eS the low energy surface adhesion and oily surface adhesion of the adhesive.
S It also improves the structural properties ofthe adhesive (e.g., cohesive strength) relative to a ho,-.ol)olyrner of the acrylic acid ester described above. FY;"..PI&S of suitable non-polar monomers include 3,3,5 trimethylcyclohexyl acrylate, cyclohexyl acrylate, isobornyl acrylate, N-octyl acrylamide, t-butyl acrylate, methyl methacrylate, ethyl methacrylate, and propyl methacrylate or col~billalions thereo~
The adhesive may contain a limited quantity (e.g., no more than 5 parts) of a polar ethylenically unsaturated monomer whose homopolymer has a solubility pal~lllè~er as measured by the Fedors method of greater than 10.50 and a Tg greater than 1 5~C to improve structural properties (e.g., cohesive strength). It is not desirable to include more than 5 parts of the polar monomer because the polar 15 monomer impairs low energy surface adhesion and oily surface adhesion, and reduces tackifier miscibility. Examples of suitable polar monomers include acrylic acid, itaconic acid, certain substituted acrylamides such as N,N dimethylacrylamide, N-vinyl-2-pyrrolidone, N-vinyl caprolactam, acrylonitrile, tetrahydrofurfuryl acrylate, glycidyl acrylate, 2-phenoxyethylacrylate, and benzylacrylate, or 20 co...bin~Lions thereof.
In the case of tackified compositions, the tackifier must be miscible with the acrylate-co~ g polymer of the adhesive such that macroscopic phase separation does not occur in order to improve the properties of the adhesive. Preferably, the adhesive is free of microscopic phase separation as well. Most commercially 25 available tackifiers are hydrocarbon-based and thus of low polarity. Such tackifiers ordinarily are not miscible with conventional, polar monomer-co~ il.;..g adhesives.
However, by incorporating a non-polar monomer into the adhesive (thereby increasing the non-polar character of the adhesive) the invention allows a variety of commercially available tackifiers to be used. The total amount of tackifier is preferably 5-60 parts per 100 parts acrylate-co.. ~ g polymer, and more preferably about 15-30 parts. The particular amount of tackifier depends on the CA 02224378 l997-l2-lO

W O 97/03144 PCTrUS96/08369 composition of the acrylate-cc,. .~ g polymer and is generally sPlected to .~,.,.;....-... peel plop~,lies without COIllplullliSin~, desired shear sl~ glll.
Because the adhesives are plere.~bly prepaled by poly~c~i~h~g the I~OllOlllGl ~ in the p-esellce of the tackifier accor~ling to a free radical process, it is 5 further desirable to select a tackifier that does not s-lbst~nti~lly impede the pol~,---c-i~alion process, e.g., by acting as a free radical scavenger, chain te-~ ;on agent, or chain transfer agent. A measure of the ability of the tackifier to inhibit free radical poly",e.i~alion in a bulk poly",t~ ion process for a given process condition is defined here as the "inhibition factor." The inhibition factor (IF) is 10 determined from the monomer conversion test and is the ratio of (1) the percent volatiles of the tackified sample (Ct) less the percent volatiles of an ic~entic~lly form--l~ted and processed sample without tackifier (CO) and (2) the percent volatiles of an identically forrn~ ted and processed sample without tackifier (CO) The inhibition factor equation is shown below:
1 5 (Ct-Co) IF= ----------------CO

Although a wide variety of tackifiers may be used, in cases where free radical polynl~ aLion is involved the class of tackifiers known under the tr~den~me Regalrez resins commercially available from Hercules are preferred. These tackifiers are produced by polymerization and hydrogenation of pure monomer hydrocarbon feed stock. Suitable resins include Regalrez resins 1085, 1094, 6108, and 3102.
The monomer mixture can be polymerized by various techniques, with photoiniti~ted bulk polymt;li~a~ion being p,erel,ed. An initiator is preferably added to aid in polymerization of the monomers. The type of initiator used depends on the polymerization process. Photoinitiators which are useful for polymerizing the acrylate monomers include benzoin ethers such as benzoin methyl ether or benzoinisopropyl ether, substituted benzoin ethers such as 2-methyl-2-hydro~ylpropiophenone, aromatic sulfonyl chlorides such as 2-naphthalenesulfonylchloride, and photoactive oxides such as l-phenyl-1,2-propanedione-2-(o-CA 02224378 l997-l2-lO

W O 97/03144 PCT/u'-5~ 9 ethoxycall,onyl)oxime. An example of a commercially available pholo~ or is IrgacureTM 651 available from Ciba-Geigy Corporation, having the formula 2,2-~lim.o,thnxy-1,2-diphenylethane-1-one). Generally, the photoiniti~tor is present in an amount of about 0.005 to 1 weight percent based on the weight of the mon~..w~ ~.5 E~alllples of suitable thermal il iLialo.~ include AIBN and peroxides.
The mixture ofthe polymerizable monomers may also contain a ~ s~ k;"g agent, or a coln~ alion of cro~linl-in~ agents, to increase the shear strength of the adhesive. Useful cro~ ;..p. agents include substituted triazines such as 2,4,-bis(trichloromethyl)-6-(4-methoxy phenyl)-s-triazine, 2,4-bis(trichloronlell,yl)-6-(3,4-dimethoxyphenyl)-s-triazine, and the chromophore-substituted halo-s-triazines disclosed in U.S. Patent Nos. 4,329,384 and 4,330,590 (Vesley) incorporated herein by reference. Other useful cro~.elinking agents include ml-ltifilnctional alkyl acrylate monomers such as trimetholpl upalle triacrylate, pentaerythritol tetra-acrylate, 1,2 ethylene glycol diacrylate, 1,4 butanediol diacrylate, 1,6 h~Y~ne~1iQl diacrylate, and 1,12 dodecanol diacrylate. Various other cro.~.~linking agents with di~en el~l molecular weights between (meth)acrylate functionality would also be useful. Generally, the crosslinker is present in an amount of about 0.005 to 1 weight percent based on the combined weight of the monomers.
Where a foam-like pressure sensitive adhesive tape is desired, a monomer blend cont~ining microspheres may be used. Suitable microspheres are commercially available from Kema Nord Plastics under the trade name "Expancel"
and from ~t~llmnto Yushi Seiyaku under the trade name "Micropearl". When ~oxp~n~ied the microspheres have a specific density of approximately 0.02-0.036 g/cc. It is possible to include the nn~qxr~n-led microspheres in the pressure sensitive adhesive composition and subsequently heat them to cause expansion when they are app~op~ialely processed, but it is generally plerellèd to mix the exr~nriçd microspheres into the adhesive. This process makes it easier to ensurethat the hollow microspheres in the final adhesive are substantially surrounded by at least a thin layer of adhesive.
Polymeric microspheres having an average diameter of 10 to 200 micrometers may be blended into the polymerizable composition in amounts from CA 02224378 l997-l2-lO

W O 97/03144 PCT/U~,5~'~B~9 about 15% to about 75% by volume prior to co~tin~ Also useful are glass microspheres having an average ~ mf~t~r of from S to 200 micrometers, plerel ably from about 20 to 80 micrometers. Such microspheres may co."p.ise 5% to 65% by volume of the pressure sensitive adhesive. Both polymeric and glass microspheres5 are known in the art. The pressure sensitive adhesive layer of the tape should be at least 3 times as thick as the ~ mPt~r of the microspheres, pl1rt;1ably at least 7 times.
Other tape constructions in which the pressure sensitive adhesives accoldi-lg to the invention are useful include ..~e~.h~"ical fasteners such as Dual-LockTM
10 brand fastener (Minnesota Mining and M~nllf~tllring Co., St. Paul, MN) and Scotcl....~teTM brand fastener (Minnesota Mining and M~nllf~ctllring Co., St. Paul, MN). The pressure sensitive adhesives are also useful in vibration damping applications.
Other materials which can be blended with the polymerizable monomers 15 prior to coating include plasticizers, tackifiers, coloring agents"t;i"ro~ ~;i,.g agents, fire ~ t;Lalda-l~, foaming agents, thermally conductive agents, electrically conductive agents, post-curing agents, and post-curing agent curatives and their accelerators, and the like.
In another plerelled embodiment, the adhesive composition also include~
20 electrically conductive materials. Such materials include, but are not limited to, metal particles and spheres such as nickel, gold, copper, or silver particles and spheres and particles coated with conductive coatings such as gold, silver, copper, or nickel coatings on copper spheres, nickel spheres, polymeric spheres or particles, and glass microspheres. Also useful are solder particles such as lead/tin alloys in 25 varying amounts of each metal (available from Sherritt Gordon, Ltd.). Examples of commercially available electrically conductive particles include conductive nickel spheres from Novamet, Inc. Electrically conductive materials are also available from Japan Chemicals, Inc., Potters Industries, and Sherritt Gordon T.imited In a pr~re..~d embodiment, the electrically conductive particles have a ~ meter less than ~ 30 the thickness of the layer of adhesive.
.

W O 97/03144 PCTrUS96/08369 Electrically con~-lctive particles can be used in amounts from about 1% to 10% by volume, and preferably in amounts from about 1% to about 5%, by volume.
For adhesives with electrically conductive particles, the adhesives may be heat aclivalâl~lc instead of pressure sensitive. The ~mount~ and types of co-S monom~r can be varied to provide pressure-sensitive or heat activatable pl Opcl Lies as desired for the end use. Larger ~m~ llnt~ of co-monomer will result in less tack and are suitable as heat activatable adhesives while lower amounts are more suitable for pressure-sensitive adhesives. The type of co-monomer can also be varied to obtain desired properties. Monomers such as N-vinyl caprolactam, N-vinyl 10 pyrrolidone, and isobornyl acrylate provide pressure-sensitive ,Olope~ lies to an adhesive up to about 40 parts by weight, while amounts above about 40 parts willprovide heat activatable adhesives. In addition, even for adhesives without electrically conductive particles, it may be desirable to have a heat activatable adhesive.
lS When using electrically conductive particles, a preferred embodiment comprises screen printable pressure bondable adhesives that are subst~nti~lly solvent free acrylic polymers that can be screen printed without requiring the use of additional solvent. As used herein, "pressure bondable" refers to adhesives that are applied to one surface, and will bond to a second surface under pressure. The 20 adhesives include pressure-sensitive adhesives which are tacky are room temperature, and heat activatable adhesives which are substantially non-tacky atroom te",pe,~ure, but will bond at an elevated temperature which is typically in the range of from about 25C to 200C.
As used herein, "substantially solvent free" refers to an adhesive that has 25 been pl epal ed without the use of large amounts of solvent. i.e., less than 5% by weight of a coating composition, pl er~, ably less than about 2%, and more pl~r~l~bly no additional solvent is added. The preparation of the adhesive includes processes used in the polymerization of the monomers present in the adhesive as well as processes used in coating the adhesive to make finished articles, e.g.
30 pressure-sensitive adhesive tapes. The terrn "solvent" refers to conventional W O 97/03144 PCTrUS96/08369 organic solvents used in the industry which include, for example, toluene, heplane, ethyl acetate, methyl ethyl ketone, acetone, and mixtures thereo~
For screen p~ g adhesives, a chain ll~l~sr~r agent is usually employed.
The chain transfer agents useful in the practice of the invention in~ d~, but are not limited to, carbon tetrabromide, n-dodecyl IllelcapL~, isoctyl thiolglycolate, and mixtures thereo~ The chain Ll~nsrer agent(s) are present in ~mol-nt~ from about 0.01 to about 1 part by weight per 100 parts of acrylate (pphj, i.e., 100 parts of the alkyl acrylate and the leil~l~;hlg co-monomer, and preferably in ~mol-nt~ from about 0.02 to 0.5 pph. For electrically conductive adhesives it is pler~lled that the ~mollnt~ of cro.c.cl '-in~ agents and the chain transfer agents is limited so that the adhesive flows s--fflci~ntly during bonding so that the conductive particles can come into contact with each other to provide conductive pathways. Plere-lt;d heat activated electrically conductive adhesives have a tan delta of greater than 1 at 140C and above, measured at 1 radian/sec. At these temperatures the adhesives have flow plopel lies similar to a viscous liquid.
For screen printing, the weight average molecular weight of the polymers of the useful adhesive compositions, i.e., syrup, is between about 50,000 and 1,000,000. Preferably, the molecular weight is between about 100,000 and about 800,000, and most preferably, between about 150,000 about 600,000. The lower molecular weights limit the elongational viscosity and result in less stringing of the adhesive during screen printing.
In a pl~relled embodiment, the adhesive composition also incllldes a thixotropic agent such as silica to impart thixotropy to the composition. The viscosity of a thixotropic composition decreases when it is subjected to shear stresses so that it flows when it is screen printed. Once the shear stress is removed, the thixotropic material increases rapidly in viscosity so that the printed adhesive F~c~çnti~lly does not flow once it has been printed onto a substrate. A suitable silica is commercially available silica under the Cab-O-SilTM trade name (such as M-5 and TS-720) from Cabot Corp. and AerosilTM 972 Silica from DeGussa.
The adhesives cont~ining electrically conductive agents of the invention are particularly useful for screen plillling directly onto a substrate when it is desired to W097/03144 PCT/U'_5.'~q?59 have adhesive only on select areas of the surface. One such substrate is a flexible electrical circuit. Flexible electrical circuits generally comprise a polymeric film coated with electrically conductive metals such as copper, which has been etched to provide electrically conductive circuit traces. The polymeric films are typica11y 5 polyimide, ~lthol~h other types of films such as polyester are also used. .C~lit~ble flexible circuits are cc.. ~ ,;ally available from such sources as Nippon Graphite, Ltd. Flexible circuits are also described in U.S. Patent Nos. 4,640,981, 4,659,872, 4,243,455, and 5,122,215. For these types of applications, pl c;~" ed compositions for the adhesives comprise from about 25 to 95 parts alkyl acrylate monomers and75 to 1 parts of at least one ~;il~lCi~ monomer that does not contain acid, and 1% to 10% by volume of electrically conductive particles. Preferably, the co-monomer is isobomyl acrylate and the electrically conductive particles are present in amounts of about 1 % to 5% by volume.
Flexible electrical circuits are used in electronic devices where an electrical and me~h~nical interconnection must be made, such as between two circuit boards,or between a circuit board and a liquid crystal display (LCD). Such connectors are useful in a variety of electronics such as in calculators, computers, pagers, cellular phones, and the like.
The adhesives according to the invention are preferably prepared by photoiniti~ted bulk polymerization according to the technique described in Martens et al., U.S. Patent No. 4,181,752, hereby incorporated by reference. Thepolymerizable monomers and a photoinitiator are mixed together in the absence ofsolvent and partially polymerized to a viscosity in the range of from about 500 cps to about 50,000 cps to achieve a coatable syrup. Alternatively, the monomers maybe mixed with a Ihi~o~,opic agent such as fumed hydrophilic silica to achieve a coatable thickness. The cros~linking agent and any other ingredients (inrl~-ling any tackifiers) are then added to the prepolymerized syrup. Altematively, these ingredients (in~.lu/ling any tackifiers but with the exception of the cro.~.slinking agent) can be added directly to the monomer mixture prior to pre-polymerization.The resulting composition is coated onto a substrate (which may be ~n~l)al~ to ultraviolet radiation) and polymerized in an inert (i.e., oxygen free) W O 97/03144 PCT~US96/08369 aL.,.os~,hel~;, e.g., a nitrogen atmosphere by exposure to ultraviolet ~.1;A~;OI~
Examples of suitable substrates include release liners (e.g., silicone release liners) and tape b~cl~ings (which may be primed or unl,-imed paper or plastic). A
sl-ffic;ently inert atmosrhere can also be achieved by covering a layer ofthe S poly".t;,i~ablc coating with a plastic film which is s~ y I~ ll to ultraviolet radiation, and irr~ ting through that film in air as described in the ~ ,cmel.lioned Martens et al. patent using ultraviolet lamps. Alternatively, instead of covering the poly...e- i~l~le co~tin~ an oxi~i7~ble tin compound may be added to the poly...~ able syrup to increase the tolerance of the syrup to oxygen as described in U.S. Pat. No. 4,303,485 (Levens). The ultraviolet light source p. er~ bly has 90% of the emissions between 280 and 400 nm (more preferably between 300 and 400 nm), with a maximum at 351 nm.
Tackifiers may also be added after polymerization of the acrylate monomers.
Where multi-layer tape constructions are desirable, one method of construction is multi-layer coating using conventional techn;ques. For example, the co~l;--g~ may be applied concurrently (e.g., through a die coater), after which the entire multi-layer structure is cured all at once. The coatings may also be applied sequ.onti~lly whereby each individual layer is partially or completely cured prior to application of the next layer.
The compositions of the invention are also useful for damping vibrations when in contact with vibratory parts, especially when the vibratory parts are made of oily metals or polymeric materials. In addition to the adhesives described above, the vibration damping materials of the invention may not be pressure sensitive adhesives. The invention provides both a damping construction comprising at least one layer of an adhesive applied to a vibratory solid article, and a damping construction comprising at least one layer of a viscoelastic material applied to a vibratory solid article.
The invention provides a damping construction comprising at least one layer of a viscoelastic material applied to a vibratory solid article, said viscoelastic 30 material coplising the reaction product of starting materials comprising:

W O 97/03144 PCT~US96/08369 (a) 3-97 parts by weight of an acrylic acid ester of a monohydric alcohol whose homopolymer has a Tg less than 0~C;
(b) 3-97 parts by weight of a non-polar ethylenically unsaturated n~ollol~le whose homopolymer has a solubility pal ~ eler of no greater than 10.50 and a Tg 5 greaterthan 15~C, and (c) 0-5 parts by weight of a polar ethylenically unsaturated ."onon.er whose homopolymer has a solubility pa,~"~:ler of greater than 10.50 and a Tg greater than lS~C, and s~lbst~nti~lly no epoxy co...ponent. In a p-e~-,ed emborlimPnt the starting materials comprise from 25 to 97 parts by weight of co~llpol1elll (a), 3 to 75 parts by weight of component (b) and 0 to 5 parts by weight of component (c).
Vibration damping is measured in terms of the loss factor which is a ratio of the energy ~ ip~ted to the energy stored. The greater the amount of energy sir~te~l~ the greater the loss factor, and therefore the better the damping 15 pl UpC~I Lies of the material. Vibration dampers operate over a range of Lelllpt:l~lu~e3 and the compositions can be form~ ted to provide optimal damping at a desired range of telnpel ~ul es.
The compositions can provide materials for vibration dampers that are pressure sensitive at room temperature, or are substantially non-tacky at room 20 te""~e,~ re, i.e., the sheet would not adhere instantly to a substrate at room teny~el~lure under finger pressure. Typically the compositions having higher z~mo~-ntS ofthe nonpolar co-monomer having a homopolymer Tg greater than 15~C, i.e., more than about 45-50 parts depending upon the co-monomer are not pressure sensitive at room temperature. If desired a non-tacky damper can be 25 adhered to a substrate by heating the substrate while in contact with the vibration damping sheet material or the non-tacky damper may be adhered to the substrate with known adhesives preferably rigid adhesives.
Vibration dampers of the invention are not particularly moisture sensitive and can provide advantages in areas where the damper is exposed to the 30 atmosphere, or where o~ltg~ing usually caused by moisture absorbed by the damper, may be a concern.

W O 97/03144 PCT~US96/08369 In practice, the compositions are typically formed into a sheet or a slab. The th~ n~e~ of the sheet is determined to a large degree by the application, and useful th ' ~ can range from about 0.015 mm to over 2.54 cm. The sheet can be applied to a con~L,~,ning layer that is stiffer than the sheet to form a co"")o~ile 5 ~rt;"~d to ae a con~L~ailled layer damper. Materials suitable for collsll~ layers , are sheets of metal, such as ~ mimlm and steel, and plastics, such as polyester. The collsLl aining layer is generally selected so that the stiffn~oee of the panel is greater than the stiffnf~5s, i.e., modulus, of the sheet material. Optimally, although not required, the ~ es ofthe panel is app.~x;...~ y equal to that ofthe object to be10 damped. The sheet can also be applied directly to the object to be damped as a free layer damper.
The vibration damping composites of the invention are particularly useful in automobile construction in which the composites can be applied directly to an automobile panel, such as a door panel, during the sLalllping stage without requiring 15 cle~ning and removal ofthe mill oils on the panel. During the ~Lalllping stage, the metal, usually cold rolled steel or ~lumim~rn, is still coated with mill oils used to prevent rust or oxidation.
The sheet materials are also useful as vibration dampers, either as a coll~Ll ained layer damper or as a free layer damper, for oily engine covers to damp 20 vibrations and reduce the noise from the engine. Sheet materials of the invention are especially advantageous in that they can be applied to the cover without requiring tedious cle~ning with solvents and/or detergents to remove the oil. In this application, the sheet materials do not need to be pressure-sensitive and can beapplied by heating the engine cover above the Tg of the damper.
The vibration damping materials of the invention are also of use in damping applications where o~ltg~eeing is of concern. Such applications include computercolllponents such as in suspension dampers for the read/write head, free layer or constrained layer dampers for disk drive covers, or for sealing together the disk drive covers. The vibration dampers of the invention can be made without acid;
30 they may be used advantageously where corrosion is a potential problem, such as on bare copper surfaces.

W O 97/03144 PCTrUS96/08369 Other useful applicalions of the invention include vibration rl~mrin~ for shock absorbers and seismic da.--pe- ~ for b~ ing~c The sheet materials can be die cut to a desired shape, for ~: . Ie a donut shape or a circular disk or they can be formed in a mold in the desired confi~ation, such as a molded slab.
The invention will now be further described by way of the following EXAMPLES
I. Adhesives for Low Ener~y Surfaces 10 Test Procedures-Low Ener~y Surface ~rlhl~;on Test procedures used in the c,~alllylcs to evaluate pressure sensitive adhesives useful for adhesion to low energy surfaces include the following.

Monomer Conversion Test (Test Procedure A-I) The monomer conversion was determined gravimetrically. A sample of the adhesive was weighed after it was coated and subsequently dried at 120 C for 3 hours and then re-weighed, The percent volatiles was taken to be indicative of the monomer conversion.

90~ Peel Adhesion Test (Test Procedure B-I) One-half inch wide strips of the adhesive sample were carefully cut and placed onto the substrate of interest. The adhesive thickness was 5 mils. A 5 mil anodized ~ mimlm backing (0.625 in, wide) was then l~min~ted to the adhesive which is applo~ll,alely 5 inches long. Test substrates of interest inr.hlded lowenergy surfaces such as polypropylene (2" x 5" x 3/16" natural polypropylene panels from Precision Punch and Plastic, Minneapolis, MN, with a mask on both sides that is removed prior to cle~ning and testing) and polycarbonate (LexanTM from General Electric Co.), and high energy surfaces such as stainless steel (304-2BA 28 gauge stainless steel with a surface roughness of 2.0 + 1.0 microinches). A free end of the backing to which the adhesive was l~min~te~ extended beyond the test substrate so that it could be clamped to a load cell to determine peel strength.

CA 02224378 1997-12-lLI

The sample was rolled back and forth twice with a 2 kg hard rubber roller to ensure contact between the adhesive and the test substrate. The adhesive was then removed after a given dwell time (usually 72 hours unless otherwise noted) at 12"/minute in a 90~ peel mode.
S The .. ~ steel ~ubsLl~les were washed once with ;IcetQne and 3 times with a 50/50 isop.opalloVwater mixture prior to testing. The plastic sub~Llales were washed 3 times with hept~ne prior to testing. The results are reported in Ibs/0.5 in. width as the average of 2 tests. All tests were conrl~lcted at room te,--pe-~lu, ~.
Shear Test (Test Procedure C-I) A 0.5 inch strip oftape was adhered to a piece of St~in~ steel (304-2BA
28 gauge ~l~i-J~s~ steel with a surface roughness of 2.0 + 1.0 microinches) which had been cleaned once with acetone and 3 times with 50/50 isop,opalloVwater suchthat a one-half square inch overlap was accomplished. A piece of 5 mil ~nor1i7ed15 ~ mim~m (0.625 in. wide) was then l~min~tçd to the entire area of the pressure sensitive adhesive, leaving an additional area to which a load could be applied. The adhesive thickness was 5 mils. The sample was then rolled back and forth twice with a 15 pound roller and allowed to dwell for four hours. The 70~C samples were a!lowed to dwell for an additional 10 mim-tes After dwelling the sample was tested 20 at either room te"")e~L-lre or 70~C. At room temperature a I kg load was applied to the adhesive and the time before the load fell was recorded. At 70~C a 500g load was applied to the adhesive and the time before the load fell was recorded. The results are reported as the average of 2 tests.

25 Co-"pa. ~Li~e Examples-Low Energv Surface Adhesion Comparative Example C I
A premix was prepared using 90 parts isooctyl acrylate (IOA), 10 parts acrylic acid (AA), and 0.04 parts 2 2-dimethoxy-2-phenylacetophenone photoinitiator (Irgacure TM 651, available from Ciba Geigy Corp.) This rnixture 30 was partially polymerized under a nitrogen-rich atmosphere by exposure to ultraviolet radiation to provide a coatable syrup having a viscosity of about W O 97/03144 P ~ ~US96/08369 3000 cps. 0.15 parts of 2~6-bis-trichlo~ yl-6-(4-meth~ h~i~yl)-s-triazine and an additional 0.16 parts of IrgacureTM 651 were added to the syrup and it was then knife coated onto a silicone-treated polyethylene-coated paper release liner at a thi~Pcs of S mils. The reS~lltin~ composite was then e AI~osed to ultraviolet radiation having a spectral output from 300-400 nm with at mq~imllm at 351 nm ina nitrogen-rich envil o~ An inlen~ily of about 1.0 mW/cm2 was used for the first one-third of the exposure time and an intensity of about 2.2 mW/cm2 was used for the second two-thirds of exposure time, rçs- ~lting in a total energy of 250 mJ/cm2. The adhesive was then tested according to the test methods listed above and the results are shown in Table I-2. The desi~n~tion "RT" means room te---pe. ~ re.
Co,l")a,ali~re Examples C2 and C3 Cc",.p~ e example C2 was prepared in the same way as con"~a,~ Je . '~ C 1 except that a premix of 94 parts of IOA and 6 parts of AA was used.
Cc"--p~ e e~alllple C3 was prepared in the same way as co",pa,~ e example C1 except that a premix of 100 parts of IOA and 0 parts of AA was used. Con,l)a, ~ e c~.~lllples C2 and C3 were tested accol~ -g to the test methods listed above and the results are shown in Table I-2.

Ex. Stainless Poly- R.T. Shear 70 Shear Percent SteelPeel propylene (Minutes) (minutes) Conversion Strength Peel Strength Cl 5.33 0.43 10 000+ 10 000+ ~98.5 C2 3.73 1.29 10 000+ 10 000+ >98.5n,.
C3 1.35 1.53 2 3 >98.5'~

Examples-Low Energv Surface Adhesion Examples 1-23 Example I was prepared in the same way as comparative example Cl except the premix consisted of 66 parts IOA, 33.5 parts isobornyl acrylate (IBA), and 0.5 parts of AA. In addition 0.09 parts of 2 6-bis-trichloromethyl-6-(4-W O 97103144 PCT/~-5~ ~~9 l~c;lL~ylJhell~ s-triazine were added after the premix was partia11y polymerized.
The composite was exposed to ultraviolet radiation having a spectral output from300-400 nm with at ...~ ... at 351 nm in a nitrogen-rich en~ o~ ;.-l at an a~/cl~ge hllell ~ily of about 2.05 mW/cm2. The total energy was 650 mJ/cm2.
F .1~ 2 was p.epal ed in the same way as Examp1e 1 except a premix co~ p. of 69 parts IOA, 30 parts IBA, and 1 part AA was used.
FY:lmplr 3 was prepared in the same way Example 1 except a premix con~i~Li-,g of 65.5 parts IOA, 34.25 parts IBA, and 0.25 parts AA was used.
FY~mrle 4 was prepared in the same way as Example 1 except a premix col~ lin~, of 65 parts IOA and 35 parts IBA was used and 0.05 parts of 2,5-bis-trichlolo~n~;l1lyl-6-(4-methoxyphenyl)-s-triazine was used.
Example S was prepared in the same way as Example 4 except a premix of 55 parts IOA and 45 parts (3,3,5-trimethylcyclohexyl acrylate (TMCA) was used.
Example 6 was prepared in the same way as Example 5 except 0.10 parts of 15 2,6-bis-trichlol~nt;ll.yl-4-(p-methoxyphenyl)-s-triazine was used.
Example 7 was prepared in the same way as Example 1 except a premix of 72 parts of IOA, 27 parts of IBA, and 1 part of AA was used.
Example 8 was p-~,pa-t;d in the same way as Example 1 except a premix of 66 pa~fs of IOA, 33 parts of IBA, and 1 part of AA was used.
Example 9 was prepared in the same way as Example 1 except a premix of 63 parts of IOA, 36 parts of IBA, and 1 part of AA was used.
Example 10 was p.epared in the same way as Example 1 except a premix of 70.75 parts of IOA, 29 parts of TMCA, and 0.25 parts of AA was used.
Example 11 was prepared in the same way as Example 1 except a premix of 64.5 parts of IOA, 35 parts of TMCA, and 0.5 parts of AA was used.
Example 12 was prepared in the same way as Example 1 except a premix of 49 parts of IOA, 51.5 parts of cyclohexyl acrylate (CHA), and 0.5 parts of AA was used.
Example 13 was prepared in the same way as Example 1 except a premix of 80 parts of IOA, 19.5 parts of N-octylacrylamide (NOA), and 0.5 parts of AAwas used.

W O 97/03144 PCT~US96/08369 Example 14 was prepaled in the same way as FY~mple 6 except a premix of 90 parts IOA, 10 parts IBA, and 0.5 parts AA was used.
F.Y~mple 15 was plepaled in the same way as FY~mrle 6 except a premix of 80 parts IOA, 20 parts IBA, and 0.5 parts AA was used.
S F---ml le 16 was pl~a,èd in the same way as FY~ ple 6 except a premix of 70 parts IOA, 30 parts IBA, and 0.5 parts AA was used.
Example 17 was p- è~Jal ed in the same way as Example 6 except a premix of 90 parts IOA, 10 parts TMCA, and 0.5 parts AA was used.
Example 18 was prepaled in the same way as Fx~mple 6 except a premix of 10 80 parts IOA, 20 parts TMCA, and 0.5 parts AA was used.
Example 19 was p- epa, c:d in the same way as Example 6 except a premix of 70 parts IOA, 30 parts TMCA, and 0.5 parts AA was used.
Example 20 was pl t;pal ed in the same way as Example 6 except a premix of 60 parts IOA, 40 parts TMCA, and 0.5 parts AA was used.
Example 21 was p-epaled in the same way as Example 6 except a premix of 55 parts IOA, 45 parts TMCA, and 0.5 parts AA was used.
Example 22 was prepared in the same way as Example 6 except a premix of 50 parts IOA, 50 parts CHA, and 0.5 parts AA was used.
Example 23 was plepal ed in the same way as Example 6 except a premix of 20 45 parts IOA, 55 parts CHA, and 0.5 parts AA was used.
The data of E~---ples 1-23 are shown in Table I-3. In the table "St. St."
refers to stainless steel. The desi~n?tion "n.t." means not tested. The dçci.~n~tion "RT" means room temperature. The dçci~n~tion "(1/2)" means that 1 ofthe 2 samples tested passed the test. The samples for peel testing in Examples 4 and 525 were p.t;pa.ed using a 15 lb. roller. A 24 hr. dwell period was used. BecauseExamples 13, 14, 17, 18, 22, and 23 do not meet the minimllm peel adhesion requh~ , they are incl~ded here as further comparative examples.

W O 97/03144 PCTrUS96/08369 T~iBLE --3 Ex. St.St.Polyprop. Polycarb. RT 70 C % Conv.
Shear Shear 1 3.10 ~ .11 ~.93 10 ~+ :0~ >9' .~~~g 2 ~.34 ~.62 ~.~9 10 ~+ :0~+ >9~.~~~9 .41 . .35 ~.~ 9 10~+ 0~+ >9 .r~
.50 2.~0 4.81 1409 51 >~ 9 3.0' 2.~4 nt 2960 1~ 3 >9x.~~ig 3.2~ 5 4.20 11-8 3~4 >9~.~~~
3.2~ 2.48 nt :0~C+ :0K+ >9~.'~-3.21 2.04 nt 0 fi 0'~+ >9~.5%
~ 3.14 2.12 nt 0K+ :0K+ >98.5~9 3.18 2.43 nt 3375 10~+ >98.5~~
11 2.39 2.08 2.92 lOK+ 10 ~+ >98.5~o 12 3.56 2.52 3.68 3960 10 ~+ >98.5%
13 2.10 1.71 2.61 2334 lOK+ >98.5~9 14 1.49 1.57 nt 1207 lOK+ >98.5~~
(1/2) lS 1.84 1.85 nt 3133 lOK+ >98.5%
16 2.23 2.28 nt lOK+ 2058 >98.5%
(1/2) :7 1.65 1.87 nt 1103 lOK+ >98.5 8 1.65 1.89 nt 3747 lOK+ >98.5n,~
:9 1.89 2.16 nt lOK+ lOK+ >98.5 (1/2) 2.31 2.41 nt lOK+ lOK+ >98.5%
21 1.90 2.69 nt lOK+ lOK+ >98.5~
22 2.87 1.18 nt lOK+ lOK+ >98.5~
23 3.53 0.95 nt lOK+ lOK+ >98.5'~9 The data of Table I-3 shows that the adhesion to low energy surfaces like polypropylene can be increased without decreasing the adhesion to high energy 5 surface such as stainless steel as was observed in the comparative examples of Table I-2. In addition the data of Table I-3 shows that desirable cohesive strength pl.,pel lies can also be achieved in the pressure sensitive adhesives of this invention.

II. Adhesives for Oily Surface Adhesion 10 Test Procedures-Oily Surface Adhesion - Test procedures used in the examples to evaluate pressure sensitive adhesives useful for adhesion to oily surfaces include the following.

CA 02224378 l997-l2-lO

W O 97/03144 PCT~U5~ 59 Monomer Conversion Test (Test Procedure A-II) The mr-nt)m~r conversion was dele"~ ed gravimetrically. 3 in. by 3 in.
~' were l ~ 1ed to a piece of ~l-----;------. foil, weighed, and placed in a forced 5 air oven at 250~F for 90 min. Samples were then equilibrated at room lell~e~alulë
and reweighed for weight loss. The percent volatiles was taken to be indicative of the mono~ner conversion.

90~ Peel Adhesion Test (Test Procedure B-II) 10One-half inch wide pieces of samples were cut out and 1 ~ ed to 5 mil thick anodized ~ mimlm which was 0.625 in. wide. The adhesive thickness was 5 mils. The release liner was then removed from the adhesive and the samples were placed onto either a stainless steel substrate (304 stainless steel with a #7 finish) or a cold rolled steel substrate (20 gauge cold plate CRS 1018 with mill finish). The 151~ steel ~ub~ e was cleaned prior to application of adhesive by wiping once with acetone and 3 times with heptane. The cold rolled steel substrate was cleaned prior to application of adhesive by wiping once with acetone.
Prior to application of the adhesive, an excess of mineral oil was applied to each cold rolled steel ~ubsll ~le with a small piece of cheese cloth and then removed to leave a coating of oil that was 1.5 ~ 0.25 mg/in.2. A free end of the b~ ing to which the adhesive was l~min~tecl extended beyond the test substrate so that it could be clamped to a load cell to d~lelln;lle peel strength. The sample was rolled back and forth twice with a 4.5 Ib roller to ensure contact between the adhesive and the test substrate. The adhesive was then removed after a given dwell time (10 sec., 1 minute, or 24 hours) at 12"/minute in a 90~ peel mode.
The values reported are in oz/0.5 in. and represent the average peel values (based on two tests) obtained between 1 and 4 inches on a 5 inch peel sample. All tests were done at room te"")e,al~lre.

W O 97103144 PCT/U~_~5/~9~9 Shear Test (Test Procedure C-II) One-half inch wide pieces of samples were cut out and l ~ ed to 5 mil thick ~nntli7ed ~1.. ;.. --.. which was 0.625 in. wide. This construction was placed on st~in'~~s steel panels (304 ~ s~ steel with a #7 finish) that had been cleaned S by wiping once with acetone and 3 times with hept~n~ Pl~cem~nt was such that a 1.0 in. x 0.5 in. adhesive sample (adhesive th:~~e~c = 5 mils) was in contact with the panel. The adhesive sample was rolled back and forth twice with a 4.5 Ib roller, with some excess material ove~l.A~ p. the sample for ~tt~Çl m~nt ofthe weight.
The samples were then allowed to dwell for 24 hours before the weight was hung on the sa~ ,les The 70~C samples were further allowed to dwell for an additional10 mimltes in the oven before the weight was applied. For the room te~ e~lule samples, a 1000 g weight was used whereas for the 70~C samples a 500 g weight was used.
The shear data are reported in min~ltes until the weight fell and represent the average of two tests.

Phase Separation (Test Procedure D-II) The p,ese"ce or absence of phase separation was judged by the optical clarity of the resulting polyacrylate/tackifier blend. The visual observation ofopacity was taken to be indicative of a phase separation.

Con")a,~ re Examples-Oily Surface Adhesion Co"~pa, ali~re Example C I
94 parts iso-octyl acrylate (IOA) and 6 parts acrylic acid (AA) were mixed together in a jar under a co~ llL nitrogen purge along with 0.4 parts of 2 2-1imethoxy_2_phenylacetophenone phuloi-,i~iator (IrgacureTM 651 available from Ciba Geigy Corp.) This mixture was partially polymerized under a nitrogen-rich atmosphere to provide a coatable syrup having a viscosity of about 3000 cps. 0.16 parts of 2 4-bis(trichlololllt;lhyl)-6-(3~4-~1im~thoxyphenyl)-s-tri~ine and an - 30 additional 0.16 parts of IrgacureTM 651 were added to the syrup and it was then knife coated onto a release coated paper b~ ing at a thickness of ~ mils. The W O 97/03144 PCT~US96/08369 resulting coating was then exposed to ultraviolet radiation having a spectral output from 300-400 nm with a m~ximllm at 351 nm in a nitrogen-rich environment. An i,llen;,ily of about 2.05 mW/cm2 was used for a total dosage of 650 mJ/cm2. The re~LIlli..~, adhesive was then tested accol ~iing to the test methods listed.
C~"llpal~ e Ex~ ples C2 and C3 Colllpal~ e eA~ll~lc C2 was prepared in the same way as colll~alali~e .oY~mple Cl except that a premix of 10 parts AA and 90 parts IOA was used. In addition, 0.12 parts triazine was used. Colllpal ~Live example C3 was l)f~)~t;d in the same way as co"lpdl~ e example Cl except that a premix of 14 parts AA and 86 parts IOA was used.

Examples-Oily Surface Adhesion Exa""~lcs 1-20 Example 1 was plepal~d in the same way as comparative example C 1 except the premix consisted of 25 parts N-octyl acrylamide (NOA) and 75 parts lauryl acrylate (LA). The NDA was heated to about 40 C prior to syruping and coating.
In addition, 0.08 parts of 2,4-bis-trichloromethyl-6-(3,4-dimethoxyphenyl)-s-triazine were added after the premix was partially polymerized.
Example 2 was p,~paled in the same way as example I except that the premix consisted of 35 parts NOA and 65 parts LA. The NOA was heated to about 40~C prior to syruping and co7~tin,~ In addition, 0.12 parts of 2,4-bis-trichloromethyl-6-(3,4-dimethoxyphenyl)-s-triazine were added after the premix was partially polymerized.
Example 3 was prepared in the same way as example I except that the premix consisted of 45 parts NOA and 55 parts LA. The NOA was heated to about 40~C prior to syruping and coating.
Example 4 was prepared in the same way as example 1 except that the premix consisted of 25 parts iso-bornyl acrylate (IBA) and 75 parts IOA.
Example 5 was prepared in the same way as example 1 except that the premix consisted of 30 parts IBA and 70 parts LA.

W O 97/03144 PCT~US96/08369 Examp1e 6 was p,~"aled in the same way as cAa",ple 1 except that the premix consisted of 40 parts IBA and 60 parts LA. In addition, 0.12 parts of 2,6-bis-trichlor~"~tl,yl-6-(3,4--limethc xyphenyl)-s-triazine were added after the premix was partially poly",el,~,ed.
Example 7 was prepared in the same way as eAample 1 except that the premix con~;sled of 30 parts IBA and 70 parts iso-decyl acrylate (IDA).
F.Y~mP'e 8 was plel)a,c:d in the same way as example 1 except that the premix con~ ed of 40 parts IBA and 60 parts IDA. In ~d~itiot~7 0.12 parts of 2,4-bis-trichlorc~ lhyl-6-(3~4-rlimethoxyphenyl)-s-triazine were added after the premix was partially polymerized.
Example 9 was prepared in the same way as example I except that the premix consisted of 40 parts lBA, 15 parts IOA, and 45 parts LA. In addition, 0.12 parts of 2,4-bis-trichloromethyl-6-(3,4--1imethQxyphenyl)-s-triazine were added after the premix was partially polymerized.
Example 10 was prepared in the same way as example 1 except that the premix consisted of 35 parts NOA, 15 parts IOA, and 50 parts LA. The NOA was heated to about 40~C prior to syruping and coating. In addition, 0.12 parts of 2,4-bis-trichloro.nell.yl-6-(3,4-~imethQxyphenyl)-s-triazine were added after the premix was partially polymerized.
Example 11 was prepared in the same way as example 1 except that the premix consisted of 35 parts NOA, 35 parts IOA, and 30 parts LA. The NOA was heated to about 40 C prior to syruping and coating. In addition, 0.12 parts of 2,4-bis-trichloromethyl-6-(3,4-dimethoxyphenyl)-s-triazine were added after the premix was partially polyrnerized.
Example 12 was prepared in the same way as example I except that the premix consisted of 35 parts NOA, 45 parts IOA, and 20 parts LA. The NOA was heated to about 40~C prior to syruping and coating. In addition, 0.12 parts of 2,4-bis-trichloromethyl-6-(3,4-dimethoxyphenyl)-s-triazine were added after the premix was partially polymerized.
Example 13 was prepared in the same way as example 1 except that the premix consisted of 35 parts IBA, 15 parts IOA, and 50 parts octadecyl acrylate CA 02224378 l997-l2-lO

W O 97/03144 PCT~US96/08369 (ODA). In addition, 0.12 parts of 2 4-bis-trichloromethyl-6-(3,4-~ l.o,cyl,he"yl)-s-triazine were added after the premix was partially poly~-c~i~ed.
FY; ...P!e 14 was plt;pal~d in the same way as rY~-..ple 1 except that the premix con:,;sled of 35 parts IBA, 35 parts IOA, and 30 parts ODA. In addition, 0.12 parts of 2,4-bis-trichloromethyl-6-(3,4-~imethoxyphenyl)-s-triazine were added after the premix was partially poly",e"~d.
Example 15 was pl epal ed in the same way as example 1 except that the premix cons;:iled of 35 parts IBA 45 parts IOA and 20 parts ODA. In adl1itiQn~
0.12 parts of 2~4-bis-trichloromethyl-6-(3~4-dimp~thoxyphenyl)-s-triazine were added after the premix was partially pol~"w"~ed.
Example 16 was plepaled in the same way as example 1 except that the premix consisted of 30 parts NOA 40 parts IOA, and 30 parts ODA. The NOA
was heated to about 40~C prior to syruping and coating. In addition 0.12 parts of 2 4-bis-trichloro.l.~:ll.yl-6-(3,4-dimethoxyphenyl)-s-triazine were added after the premix was partially polymerized.
Example 17 was prepared in the same way as example I except that the premix consisted of 67 parts IOA, 32.5 parts IBA and 0.5 parts AA. In addition 0.12 parts of 2 4-bis-trichloromethyl-6-(3 4-dimethoxyphenyl)-s-triazine were added after the premix was partially polymerized.
Example 18 was prepared in the same way as example 1 except that the premix cons;s~ d of 69 parts IOA, 30 parts IBA and 1 part AA. In addition, 0.12 parts of 2,4-bis-trichloromethyl-6-(3 4-dimethoxyphenyl)-s-triazine were added after the premix was partially polymerized.
Example 19 was p. epa- ed in the same way as example 1 except that the premix consisted of was 71 parts IOA 27 parts IBA~ and 2 parts AA. In addition, 0.12 parts of 2 4-bis-trichloromethyl-6-(3 4-dimethoxyphenyl)-s-triazine were added after the premix was partially polymerized.
Example 20 was pl epal ed in the same way as example 1 except that the premix consisted of 76 parts IOA, 21 parts IRA, and 3 parts AA. In addition, 0.12 parts of 2,4-bis-trichloromethyl-6-(3 4-dimethoxyphenyl)-s-triazine were added after the premix was partially polymerized.

W O 97103144 PCT~US96/08369 The data of Examples 1-20, as well as co,l,pa,~ e ~ "",les Cl, C2, and C3, are shown in Table II-2. The dç~i~n~tion "DNS" means the adhesive did not stick to the substrate. The desi~n~tion "nt" means not tested.
. _ CA 02224378 l997-l2-lO

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~ 3 ' - - ~ ~ ~ ~ ~ ~ ~ - ~ c~ v v W O 97103144 PCT~US96/08369 m. Tackified Pressure Sensitive Adhesives Test Procedures-Tackified P, es~u~ e Sensitive Adhesives Test procedures used in the cAa-llples to evaluate tackified pr~s~u~e sensitive adhesives indude the following.
s Monomer Conversion Test (Test Procedure A1-III) The monomer conversion was determined gravimetrically. A sample of the adhesive was weighed after it was coated and subsequently dried at 120~C for 3 hours and then re-weighed. The percent volatiles was taken to be indicative of the monomer conversion.

Monomer Conversion Test (Test Procedure A2-III) The monomer conversion was determined gravimetrica11y. 3 in. by 3 in.
samples were l~min~ted to a piece of all-minum foil, weighed, and placed in a forced air oven at 250~F for 90 min. Samples were then equilibrated at room te,l,l)e~ure and re-weighed for weight loss. The percent volatiles was taken to be indicative of the monomer conversion.

90~ Peel Adhesion Test (Test Procedure B I -III) One-half inch wide strips of a 5 mil adhesive sample were carefully cut and placed onto the substrate of interest. A 5 mil anodized aluminum backing, 0.625 in, wide, was then l~min~ted to the adhesive which is approximately S inches long.
Test substrates of interest included low energy surfaces such as polypropylene (2" x 5" x 3/16" natural polypropylene panels available from Precision Punch and Plastic, Minneapolis, MN, having a mask on both sides that is removed prior to cleaning and testing) and polycarbonate (LexanTM available from General Electric Co.), and high energy surfaces such as stainless steel (304-2BA 28 gauge stainless steel with a surface ro~lghnçc.c of 2.0 ~ 1.0 microinches). A free end of the backing to which the adhesive was l~min~ted extended beyond the test substrate so that it could be clamped to a load cell to determine peel strength. The sample was rolled twice back and forth with a 2 kg hard rubber roller to ensure contact between the W O97/03144 PCT~US96/08369 adhesive and the test ~ulJ~ le. The adhesive was then removed after a given dwell time (usually 72 hours unless otherwise noted) at 12"/minute in a 90~ peel mode.The peel data are reported in Ibs/0.5 in. width. and r~se~l the average oftwo tests.
The ~ steel ~ub~L-~Ies were washed once ~vith acetone and 3 times with a 50/50 isop..,panoVwater mixture prior to testing. The plastic s~sl-~les were washed 3 times with heptane prior to testing.

90~ Peel Adhesion Test (Test Procedure B2-III) One-half inch wide pieces of samples were cut out and l~min~ted to 5 mil thick anodized ~hlmimlm which was 0.625 in. wide. The adhesive thicl~ness was 5 mils. The release liner was then removed from the adhesive and the samples were placed onto either a stainless steel substrate (304 stainless steel with a #7 finish) or a cold rolled steel ~ub~ le (20 gauge cold plate CRS 1018 with mill finish). Thestainless steel substrate was cleaned prior to application of adhesive by wiping once with acetone and 3 times with heptane. The cold rolled steel substrate was cleaned prior to application of adhesive by wiping once with acetone.
Prior to application of the adhesive. an excess of mineral oil was applied to each cold rolled steel substrate with a small piece of cheese cloth and then removed to leave a coating of oil that was 1.5 + 0.25 mg/in.2. A free end of the backing to which the adhesive was l~min~ted extended beyond the test substrate so that it could be clamped to a load cell to determine peel strength. The sample was rolled back and forth twice with a 4.5 Ib roller to ensure contact between the adhesive and the test substrate. The adhesive was then removed after a given dwell time (10 sec., 1 minute, or 24 hours) at 12"/minute in a 90~ peel mode.
The values reported are in oz/0.5 in. and represent the average peel values (based on two tests) obtained between 1 and 4 inches on a 5 inch peel sample. All tests were done at room temperature.

W O 97/03144 PCT~US96/08369 Shear Test (Test Procedure C 1 -m) A 0.5 inch strip of tape was adhered to a piece of stainless steel (304 st~inl~c~ steel with a #7 finish) which had been cleaned once with acetone and 3times with 50/50 isoplopd~-ol/water such that a one-half square inch overlap wasS acco~p!~ A piece of 5 mil anodized ~Inmim~m was then ~ led to the entire area of the p. c~:,u. e sensitive adhesive, leaving an additional area to which a load could be applied. The th;~l~n~s~ of the adhesive was S mils. The sample was thenrolled twice back and forth with a 15 pound roller and allowed to dwell for fourhours. The 70~C samples were further allowed to dwell for 10 min--tes at 70~C.
10 After dwelling the sample was tested at either room temperature or 70~C. At room temperature a 1 kg load was applied to the adhesive and the time before the loadfell was recorded. At 70~C a 500g load was applied to the adhesive and the time before the load fell was recorded.
The shear data are reported in minutes and represent the average of two 15 tests.
Shear Test (Test Procedure C2-III) One-half inch wide pieces of samples were cut out and l~min~ted to S mil thick anodized alnmim~m which was 0.625 in. wide. This construction was placed on stainless steel panels (304 stainless steel with a #7 finish) that had been cleaned 20 by wiping once with acetone and 3 times with heptane. Placement was such that a 1.0 in. x 0.5 in. adhesive sample (adhesive thickness = 5 mils) was in contact with the panel. The adhesive sample was rolled back and forth twice with a 4.5 Ib roller, with some excess material overh~nging the sample for attachment of the weight.
The samples were then allowed to dwell for 24 hours before the weight was hung 25 on the samples. The 70~C samples were further allowed to dwell for an additional 10 min--tçs in the oven before the weight was applied. For the room temperature samples, a 1000 g weight was used, whereas for the 70~C samples a 500 g weight was used.
The shear data are reported in minutes until the weight fell and represent the 30 average of two tests.

CA 02224378 l997-l2-lO

W O 97/03144 PCT~US96/08369 Phase Separation (Test Procedure D-III) The presence or absence of phase separation was judged by the optical clarity ofthe resulting polyacrylate/t~t ifi~r blend. The visual observation of opacity was taken to be indicative of a phase separation.
F~ PlF.5 Tackified ~les~u~e Sensitive Adhesive Examples 1-56 h',..' '~ 1:
100 parts by weight of iso-octyl acrylate (IOA), iso-bornyl acrylate (113A), and acrylic acid (AA) with a monomer ratio of 80/ 19. S/0.5 (IOA/IBA/AA) was blended with 0.04 parts of b~n7.il~1imethylketal (KB- 1, SARTOMER Compal-y) photc,;.,;~ Qr and photopolymerized with an ultraviolet light source under a constant nitrogen purge to a viscosity of about 2000 cps. Q.16 parts of additional benzildimethylketal photoinitiator, 0.15 parts of 2,4-bis(trichloro~ llyl)-6-(4-methoxyphenyl), and 20 parts of Regalrez 1085 tackifier resin (EIercules Co.) were added to the acrylate syrup and mixed until all of the components had completelydissolved. After mixing, the blend was knife- coated at a S mil thickness onto asilicone-treated polyethylene-coated paper release liner. The composite was thenexposed to ultraviolet radiation having a spectral output from 300-400 with a m~cimllm at 351 nm in a nitrogen-rich environment. The average intensity was about 2.05 mW/cm2. r~ -lting in a total energy of 650 mJ/cm2.
Example 2 was prepared in the same way as Example I except 40 parts of Regalrez 1085 tackifier was used.
Example 3 was prepared in the same way as Example I except Regalrez 1094 tackifier (Hercules Co.) was used.
Example 4 was prepared in the same way as Example I except 40 parts of Regalrez 1094 tackifier was used.
Example S was pl epal t:d in the same way as Example I except Regalrez 1128 tackifier (Hercules Co.) was used.
Example 6 was prepared in the same way as Example 1 except 40 parts of Regalrez 1128 tackifier was used.

CA 02224378 l997-l2-lO

W O 97/03144 PCTrUS96/08369 Example 7 was pl ~al ed in the same way as Example 1 except Regalrez 6108 tackifier (Hercules Co.) was used.
F.Y~mp~e 8 was plt:paled in the same way as Example 1 except 40 parts of Regalrez 6108 tackifier was used.
S F.Y~mple 9 was pl~l)~ed in the same way as Example 1 except Regalrez 3102 t~ ifiPr ~ercules Co.) was used.
F.~Y~mple 10 was prepaled in the same way as Example 1 except 40 parts of Regalrez 3102 t~cl~ifier was used.
Example 11 was pl e~)al ed in the same way as Example 1 except Regalrez 10 5095 tackifier (Hercules Co.) was used.
Example 12 was prepared in the same way as Example 1 except 40 parts of Regalrez 5095 tackifier was used.
Example 13 was prepared in the same way as Example 1 except Escorez 5340 tackifier (Exxon Co.) was used.
Example 14 was prepare in the same way as Example 1 except 40 parts of Escorez 5340 tackifier was used.
Example 15 was prepared in the same way as Example I except Arakawa KE-311 tackifier (Arakawa) was used.
Example 16 was prepared in the same way as Example I except 40 parts of Arakawa KE-311 tackifier was used.
Example 17 was prepared in the same way as Example I except Escorez 5300 tackifier (Exxon Co.) was used.
Example 18 was prepal t;d in the same way as Example I except 40 parts of Escorez 5300 tackifier was used.
Example 19 was prepared in the same way as Example I except Arkon E90 tackifier (Arakawa) was used.
Example 20 was prepared in the same way as Example I except 40 parts of Arkon E90 tackifier was used.
Example 21 was prepared in the same way as Example I except Arkon Pl l~
tackifier (Arakawa) was used.

W O 97/03144 PCT~US96/08369 FYrm~e 22 was p.~aled in the same way as Er.al~lple 1 except 40 parts of Arkon P115 tz~ ifi~r was used.
F.Y~mple 23 was prepa,ed in the same way as Example 1 except Regalite 90 t?~ ifiPr (Hercules Co.) was used.
F - le 24 was prepaled in the same way as F.Y~mple 1 except 40 parts of Regalite 90 t~cl~ifier was used.
F.Y~ le 25 was p.epaled in the same way as FYS~ PIC 1 except Exxon ECR
165B t~r~ifiPr was used. .
r!Y~ ple 26 was pl~pa,~d in the same way as Exa~l~ple 1 except 40 parts of 10 Exxon ECR 165B tackifier was used.
F. - l le 27 was prepared in the same way as Example 1 except Exxon ECR
177 tackifier was used.
Example 28 was prepared in the same way as Example I except 40 parts of Exxon ECR 177 tackifier was used.
Example 29 was plepa,c~d in the same way as Example 1 except Arkon M100 tackifier (Arakawa) was used.
Example 30 was prepared in the same way as Example 1 except 40 parts of Arkon M100 tackifier was used.
Example 31 was prepared in the same way as Example 1 except Arkon M90 20tackifier (Arakawa) was used.
Example 32 was prepared in the same way as Example 1 except 40 parts of Arkon M90 tackifier was used.
Example 33 was prepared in the same way as example 1 except Hercotac RT110 tackifier (Hercules Co.) was used.
25Example 34 was prepared in the same way as Example 1 except 40 parts of Hercotac RT110 tackifier was used.
Example 35 was pl t;pal ~d in the same way as example 1 except Escorez 5380 tackifier (Exxon Co.) was used.
Example 36 was prepared in the same way as Example 1 except 40 parts of 30Escorez 5380 tackifier was used.

CA 02224378 l997-l2-lO

W O97/03144 PCTrUS96/08369 ;....ple 37 was p.cp~ed in the same way as Ex~ ple 1 except Foral 85 tackifier (Hercules Co.) was used.
FY~mple 38 was plepared in the same way as Example 1 except 40 parts of Foral 85 t~Lifier was used.
Example 39 was pl~;paled in the same way as Example 1 except Kristalex 5140 t~rl~ifi~r (Hercules Co.) was used.
FY~mple 40 was prepared in the same way as Example 2 except 40 parts of Kristalex 5140 tackifier was used.
Lxa..-ple 41 was p-t;pa-ed in the same way as Example 1 except Hercotac 10 lOOS tackifier (Hercules Co.) was used.
Exampie 42 was p~ epal t:d in the same way as Example 1 except 40 parts of Hercotac 100S t~cLifier was used.
Example 43 was prepared in the same way as Example 1 except Regalite 355 tackifier (Hercules Co.) was used.
Lx~-.ple 44 was prepa,c:d in the same way as Example 1 except 40 parts of Regalite 355 tackifier was used.
Example 45 was plepaled in the same way as Example 1 except Willgtack Plus tackifier (Goodyear Co.) was used.
Example 46 was prepare in the same way as Example I except 40 parts of Wingtack Plus tackifier was used.
Example 47 was prepared in the same way as Example 1 except Hercotac RT 400 tackifier (Hercules Co.) was used.
Example 48 was prepared in the same way as Example 1 except 40 parts of Hercotac RT 400 tackifier was used.
Example 49 was prepared in the same way as Example 1 except Piccotac HM2162 tackifier (Hercules Co.) was used.
Example 50 was prepared in the same way as Example 1 except 40 parts of Piccotac HM2162 tackifier was used.
Example 51 was prepared in the same way as Example 1 except Kristalex 3100 tackifier (Hercules Co.) was used.

W O 97/03144 PCT~US96/08369 ry~mrle 52 was p-~a-t;d in the same way as Example 1 except 40 parts of Kristalex 3100 tackifier was used.
FY~mrle 53 was p-~aled in the same way as Example 1 except Kristalex 1120 t~ ifiçr (Hercules Co.) was used.
F~c~mple 54 was plepdled in the same way as Example 1 except 40 parts of Kristalex 1120 tackifier was used.
E~alllple 55 was p.~al~d in the same way as Example 1 except Piccolyte A135 tackifier (Hercules Co.) was used.
rY~...p le 56 was p,~aled in the same way as Example 1 except 40 parts of 10 Piccolyte A135 tackifier was used.
The inhibition factor and phase separation characteristics of the above examples are shown in Table III-2. The polypropylene peel strength of several samples were determined acco- ding to Test Procedure B I -III and are reported in Table III-2 as well. If the samples possessed an inhibition factor greater than 1.0 15 the sample was dried in a 120 C oven to reduce the inhibition factor below 1 prior to testing. The dçeign~tion "nt" means not tested. The de~ign~tion "na" means not applicable. The designation "nc" means not conclusive.

ExampleInhibitionFactor Phase Polypropylenepeel separationstrength (Ib/0.5") 0.06 no nt 2 0.11 no nt 3 0.14 no nt 4 0.37 yes 3.37 0.16 yes 3.20 6 0.54 yes 2.71 7 0.19 no ~ .~8 8 0.40 no : . ' 2 9 0.20 no ''.78 0.39 no 1.07 11 0.34 no nt 12 0.80 no nt 13 0.46 yes nt 14 1.06 yes nt 0.51 no 2.53 16 1.42 no 3.90 17 0.73 yes nt CA 02224378 l997-l2-lO

ExampleInhibition Factor Phase Polypropylene peel sel~a,~liollsllt;~ Lh (Ib/0.5") 18 1. 0 yes r:
19 0.74 no ~."9 1.-5 no .90 21 0.-6 yes -.01 22 1." no :.60 23 0.''" no nt 24 1.' 3 no nt 0.80 yes nt 26 1.33 Yes nt 27 0.81 yes nt 28 1.22 yes nt 29 0.89 no 2.93 ~0 1.89 no 3.90 ~: 0.96 no 2.7~.
~'' 1.88 no 4.0 33 1.25 no 1.26 34 3.11 yes 0.79 1.34 yes nt 36 2.42 yes nt 37 1.52 no nt 38 2. '3 no nt 39 : .61 nc nt ".,1 nc 0.69 41 .66 no 2.29 42 4.58 no 2.10 43 2. 5 no 5.1 44 2.99 no 2.9~
2.34 no 3.06 46 5.74 no 5.33 47 2.68 no 2.90 48 5.95 no 0.72 49 2.94 no 2.82 6.50 no 3.98 51 3.03 nc nt '2 4.11 nc 0.55 53 >6.5 na nt 54 >6.5 na nt ~6.5 na nt 56 >6.5 na nt CA 02224378 l997-l2-lO

W O 97/03144 PCT~US96/08369 The data of Table m-2 shows that several COIIL llel cial tackifiers are soluble in the non-polar acrylate pressure sensitive adhesive matrix but that only the Regalrez tackifying resins have low inhibition factors as well.

Fx;3.. pl~ 57-115 F.Yr--~le 57 was pl~pal~;d in the same way as F.Y~mple 1 except an 85/15/0 IOA/IBA/AA monomer ratio was used.
F.x~rl~ 58 was plepaled in the same way as Example 57 except 40 parts of Regalrez 1085 t~çlrifi~r was used.
Example 59 was prepared in the same way as Example 1 except an 85/14/1 IOA/IBA/AA l.lollolllel ratio was used.
Example 60 was prepared in the same way as Example 1 except an 85/13/2 IOA/IBA/AA monomer ratio was used.
Example 61 was p,~pal~;d in the same way as Example 1 except an 85/11/4 IOA/IBA/AA monomer ratio was used.
Example 62 was prepared in the same way as Example 57 except 20 parts of Regalrez 6108 tackifier was used.
Example 63 was prepared in the same way as Example 62 except 40 parts of Regalrez 6108 tackifier was used.
Example 64 was prepared in the same way as Example 62 except an IOA/IBA/AA ratio of 85/14/1 was used.
Example 65 was prepared in the same way as Example 64 except 40 parts of Regalrez 6108 tackifier was used.
Example 66 was prepared in the same way as Example 64 except an IOA/IBA/AA ratio of 85/13/2 was used.
Example 67 was prepared in the same way as Example 66 except an IOA/IBA/AA ratio of 85/12/3 was used.
Example 68 was prepared in the same way as Example 57 except 20 parts of Regalrez 3102 tackifier was used.
Example 69 was prepared in the same way as Example 68 except 40 parts of Regalrez 3102 tackifier was used.

W O 97103144 PCT~US96/08369 Example 70 was plepaled in the same way as Example 68 except an IOA/IBA/AA ratio of 85/14/1 was used.
Example 71 was prepared in the same way as Example 70 except 40 parts of Regalrez 3102 t~ fier was used.
S Example 72 was pl epal ed in the same way as Example 70 except an IOA/IBA/AA ratio of 85/13/2 was used.
Example 73 was prepared in the same way as Example 72 except an IOA/IBA/AA ratio of8511213 was used.
Example 74 was prepared in the same way as Examp1e 57 except 20 parts Of Regalrez 1094 tackifier was used.
Example 75 was prepared in the same way as Example 74 except 40 parts Of Regalrez 1094 tackifier was used.
Example 76 was prepared in the same way as Example 74 except an IOA/IBA/AA ratio of 85/14/1 was used.
Example 77 was prepared in the same way as Example 74 except an IOA/IBA/AA ratio of85/13/2 was used.
Example 78 was prepared in the same way as Example 57 except an IOA/IBA/AA ratio of90/9/1 was used.
Example 79 was prepared in the same way as Example 78 except an IOA/IBA/A~ ratio of 81/13/1 was used.
Example 80 was prepared in the same way as Example 79 except 30 parts of Regalrez 1085 was used.
Example 81 was prepared in the same way as Example 79 except an IOA/IBA/AA ratio of76/23/1 was used.
Example 82 was prepared in the same way as Example 81 except 40 parts Of Regalrez 1085 was used.
Example 83 was prepared in the same way as Example 81 except an IOA/IBA/AA ratio of 81/17/2 was used.
Example 84 was prepared in the same way as Example 81 except an IOA/IBA/AA ratio of76/22/2 was used.

-W O 97103144 PCT~US96/08369 F.Y~mple 85 was prepared in the same way as Example 62 except an IOA/IBA/AA ratio of 90/9/1 was used.
Example 86 was prepa~c;d in the same way as F.Y~mple 85 except 30 parts of Regalrez 6108 was used.
F - le 87 was prepared in the same way as FY~mrle 85 except an IOA/IBA/AA ratio of 81/18/1 was used F.Y;~ P1~: 88 was pl~aled in the same way as Example 87 except 40 parts of Regalrez 5108 was used.
F . l~ 89 was p,~aled in the same way as Example 85 except an IOA/IBA/AA ratio of 76/23/1 was used.
Example 90 was prepared in the same way as Example 89 except 40 parts of Regalrez 5108 was used.
Example 91 was prepared in the same way as Example 85 except an IOA/IBA/AA ratio of 90/8/2 was used.
Example 92 was plepal ed in the same way as Example 91 except an IOA/IBA/AA ratio of 85/13/2 was used.
Example 93 was prepared in the same way as Example 92 except an IOA/IBA/AA ratio of 81/17/2 was used.
Example 94 was plepaled in the same way as Example 93 except 30 parts of Regalrez 6108 was used.
Example 95 was pl ~pa~ ~d in the same way as Example 94 except 40 parts of Regalrez 6108 was used.
Example 96 was prepared in the same way as Example 92 except an IOA/IBA/AA ratio of 76/22/2 was used.
Example 97 was prepared in the same way as Example 96 except 30 parts of Regalrez 6108 was used.
Example 98 was p~ ~pal ed in the same way as Example 97 except 40 parts of Regalrez 6108 was used.
Example 99 was prepared in the same way as Example 68 except an IOA/IBA/AA ratio of 90/9/1 was used.

F.Xr ~ 100 was prepared in the same way as Example 99 except 30 parts of Regalrez 3102 was used.
F.x~mrle 101 was pr~pal ~;d in the same way as FYA~ J1e 68 except an IOA/IBA/AA ratio of 81/18/1 was used.
F~ e 102 was pr~;~)~t;d in the same way as F.Y~n~ple 101 except 30 parts of Regalrez 3102 was used.
Example 103 was prepared in the same way as Example 68 except an IOA/IBA/AA ratio of 76/23/1 was used.
Example 104 was pl-epaled in the same way as Example 103 except 30 parts of Regalrez 3102 was used.
Example 105 was prepared in the same way as Example 68 except an IOA/IBA/AA ratio of 90/8/2 was used.
Example 106 was prepared in the same way as Example 68 except an IOA/IBA/AA ratio of 81/17/2 was used.
Example 107 was prepared in the same way as Example 106 except 40 parts of Regalrez 3102 was used.
Example 108 was prepared in the same way as Example 68 except an IOA/IBA/AA ratio of 76/22/2 was used.
Example 109 was prepared in the same was as Example 74 except 10 parts of Regalrez 1094 was used and a monomer ratio of 90/9/ 1 IOA/IBA/AA was used.
Example 110 was prepared in the same way as Example 74 except a monomer ratio of 81/18/1 IOA/IBA/AA was used.
Example 111 was prepared in the same way as Example 109 except a monomer ratio of 76/23/1 IOA/IBA/AA was used.
Example 112 was prepared in the same way as Example 111 except 20 parts of Regalrez 1094 was used.
Example 113 was prepared in the same way as Example 109 except 10 parts of Regalrez 3102 was used, 0.09 parts of 2,4-bis(trichloromethyl)-6-(4-methoxyphenyl)-s-triazine crosslinker was used, N-octyl acrylamide (NOA) was used instead of IBA, and the monomer ratio was 89/10.5/0.5 IOA/NOA/AA.

W O 97/03144 PCT~US96/08369 FY;~..jle 114 was prepa,ed in the same way as E~ e 113 except that 30 parts Regalrez 3102 was used.
F.Y~mple 115 was p,epaled in the same way as Fy~Fle 62 except an IOA/IBA/AA ratio of 9S/4.75/0.25 was used and 25 parts Regalrez 6108 was used.
Co"")~ e Example Cl 90 parts by weight of iso-octyl acrylate (IOA) and 10 parts acrylic acid (AA) were blended with 0.04 parts of 2,2-dimethoxy-2-phenylacetophenone pholoi~ r argacureTM 651, available from Ciba-Geigy Corp.) and photopolymerized with an ultraviolet light source under a constant nitrogen purge to a viscosity of about 3000 cps. 0.16 parts of additional 2 2-~im.o~thoxy-2-phenylacetophenone photoinitiator and 0.15 parts of 2 4-bis(trichloromethyl)-6-(4-methoxyphenyl)-s-tri~ine were added to the acrylate syrup and mixed until all ofthe components had co""~let~ly dissolved. After mixing the blend was knife-coated at a 5 mil thickness onto a silicone-treated polyethylene-coated paper release liner.
The composite was then exposed to ultraviolet radiation having a spectral outputfrom 300-400 with a m~ximum at 351 nm in a nitrogen-rich environment. An intensity of about 1.0 mW/cm2 was used for the first one-third of the exposure time and an intensity of about 2.2 mW/cm2 was used for the second two-thirds of the exposure time resulting in a total energy of 250 mJ/cm2.
Co",pa~Li~re example C2 was prepared in the same way as co"~pa,~ e example C 1 except a premix of 94 parts IOA and 6 parts AA was used.
Conll)a, ~ e example C3 was prepared in the same way as comparative example Cl except a premix of 100 parts IOA and 0 parts AA was used.
The data of Example 57-115 and comparative examples Cl, C2, and C3 are shown in Table III-3. Test procedures Al-III Bl-III and Cl-III were used to generate the data. The designation "nt" means not tested.

W O 97/03144 PCTrUS9~ 9 TA~BLE Il~-3 Ex. St.St.Poly- Room 70~C Percent Peel propylene TempShear Conversion (Ib/O.S") peel (Ib/0.5") Shear - J7 3.833.63 313 35 >g~ ~u~
' 8 3.73'.87 00~ ~ >9~.' ~~-rg 4.15~.OS ' 86 10~+ >9 ~ rU~s 2.66~.84 ~ 10~+ >9~.~%
61 ~.72.75 10~.+ 8~9 >98.5~~;
62 ~.lS3.64 S~S 34 >98.5U~o 63 ~.0~6.24 719 23 >98.5~
64 4.223.54 7223 lOK+ >98.5n,9 5.336.84 29 6 41 >98.5%
66 6.923.85 lO~C+ lOK+ >98.5(~9 67 4.043.30 10.~+ lOK+ >9".5'/.
6~ 3.212.52 ~0 30 >9'.~%
69 4.242.57 6 2 S >9~.SQ~
4.112.67 4900 lOK+ >9~.5Q~
71 4.943.04 13~8 12 >9~.'%
72 3.622.58 lOK+ lOK+ >9~.5~/~
73 4.273.63 lOK+ lOK+ >9~ 5U/o 74 2.583.24 708 nt >9~.'%
3.223.26 1301 nt >98.5'/o ~6 3.503.54 lOK+ lOK+ >98.5%
~7 3.903.38 lOK+ lOK+ >98.5%
8 2.69r5 2003 1870 >98. ~%
9 3.24~ . '7 I OK+ 3961 >9- r'/o ~0 2.'72.47 1865 27 >9~.5"~
~1 4.-23.34 4639 1714 >9~.5~i~
~2 3.003.91 242 5 >98.5~/~
83 3.053.00 5021 1902 >98.5C/o 84 3.393.56 3040 888 >98.51/o 3.282.82 lOK+ IOK+ >98.5'/o 8n 3.364.87 lOK+ 5307 >98.5~~
8- ~.963.01 IOK+ IOK+ >98.5~/.
8~ ~.6C5.65 2094 22 >98.' ~
8~ :.763.43 lOK+ 1376 >98.'~/~
~.763.10 5605 18 >98.5~/.
91 3.342.87 lOK+ lOK+ >98.5'/o 92 6.923.85 lOK+ IOK+ >98.5U/o 93 4.863.35 IOK+ IOK+ >98.5%
94 4.204.61 lOY+ 1287 >98.5r/o - 9S 5.733.18 10 ~+ 60 >98.5%
96 4.551.75 IOK+ IOK+ >98.5Q/o 97 5.885.44 10 ~+ 207 >98.5%

W O 97/03144 PCT~US~ C9 Ex. St.St.Poly- Room 70~C Percent Peelpropylene Temp Shear Conversion (lb/0.~")peel (lb/0.5") Shear 98 4.5" 4.38 7187 26 >gx.~
99 3.0'' ".~9 10K+ 10K+ >9~.~ ~~
00 ~.5~ ~' 16 1795 >9 :0: ~ .6~: ."," ': 96 10K+ >9'.5~
:0'' ~.~ 13 >9 . ~-:0~ 0 6 9~ 10~Y+ >9''.~~i.
0~ .'9 .64 lOV+ 1'5 >9".~~~-:0' 3.-2 ''.~1 10 -+ 10~+ >9 '.5~~9 06 3.61 .96 10~+ 10Y+ >9~ iO
:07 6.63 ~.62 4906 49 >g~ oi9 108 4.46 4.11 10K+ 10K+ >98.5~~
109 2.38 2.85 2"3 10K+ >9~,J~~3 110 3.06 3.90 10 ~+ 10K+ >9'',~Qi~
11 2.6" 3.05 10~+ 10K+ >9~.5~~
11" 4.5'' 4.54 10 ~+ 10K+ >9~ oi9 :: 2.6 2.46 2297 150 >48. %
:~ 3.66 4.06 616 12 >9~.~~~O
: :' nt nt 2504 329 >9~.5~O
Cl 5.3J 0.43 10,000+lo,ooo+ >9" 5Oi:, C2 3.7~ 1.29 10,000+10,000+ >9 C3 1.3' 1.53 2 3 >98.~~~-Examples 116- 124 83 parts IOA and 17 parts IBA were mixed together in a jar under a consl~ilL nitrogen purge along with 0.04 parts of Irgacure 651 photoinitiator from Ciba-Geigy Corp. (2,2-dimethoxy-2-phenylacetophenone) This mixture was exposed to a low intensity ultraviolet light under a constant nitrogen purge while stirring until a coatable viscosity syrup was obtained. The conversion of this syrup was between 4 and 10% and the viscosity was about 3,000 cps. 0.12 parts of 2,4-bis(trichloromethyl)-6-(3,4-dimethoxyphenyl)-s-triazine and an additional 0.16 parts Irgacure 651 were then added to the prepolymerized syrup, along with 20.5 parts of Regalrez 6108 tackifier (Hercules Co.). The ingredients were mixed thoroughly until homogeneous and then knife-coated at a 5 mil thickness onto a silicone-treated polyethylene-coated paper release liner. The composite was then exposed to ultraviolet radiation having a spectral output from 300-400 with a maximum at 351 W O 97/03144 PCT~US96/08369 nm in a lutlog~n-rich en~,;,olu"~"t. The average ;"len~ily was about 2.05 mW/cm2.
resulting in a total energy of 650 mJ/cm2.
Example 117 was pre,oalc;d in the same way as example 116 except that the mon~>m~r mixture was 77 parts IOA and 23 parts IBA. Also, 13.6 parts Regalrez 5 6108 was used.
Example 118 was p. epa, ed in the same way as eY~mrle 116 except that the mnns)m.or mixture was 71 parts IOA and 21 parts IBA. Also, 7.5 parts Regalrez 6108 was used.
Example 119 was p.t;l)aled in the same way as ~ le 116 except that the 10 lllonolner mixture was 84 parts IOA, 15 parts IBA, and I part AA. Also, 20.5 parts Regalrez 6108 was used.
Example 120 was prepared in the same way as example 116 except that the monomer mixture was 81 parts IOA, 18 parts IBA, and 1 part AA. Also, 17.6 parts Rega1rez 6108 was used.
Example 121 was prepared in the same way as example 116 except that the monomer mixture was 72 parts IOA, 27 parts IBA, and I part AA. Also, 7.5 parts Regalrez 6108 was used.
Example 122 was prepared in the same way as example 116 except that the monomer mixture was 83 parts IOA and 17 parts IBA Also, 5 parts Regalrez 6108 20 was used.
Example 123 was prepared in the same way as example 122 except that 15 parts Regalrez 6108 was used.
Example 124 was prepared in the same way as example 122 except that 30 parts Regalrez 6108 was used.
Comparativel~ m"~ C4 94 parts IOA and 6 parts AA were mixed together in a jar under a constant nitrogen purge along with 0.04 parts of Irgacure 651 photoinitiator from Ciba-Geigy Corp. (2,2-dimethoxy-2-phenylacetophenone). This mixture was partially 30 polymerized under a nitrogen-rich atmosphere to provide a coatable syrup having a viscosity of about 3,000 cps. 0.16 parts of 2,4-bis(trichloromethyl)-6-(3,4-W O 97/03144 PCTIU~ 9 ~limp~th~ yl~hellyl)-s-triazine and an additional 0.16 parts Irgacure 651 were then added to the prepolynleli~ed sy~up and it was then knife-coated onto a release coated paper backing at a th;~l~ness of 5 mils. The res--ltins~ coating was thenexposed to ultraviolet radiation having a spectral output from 300-400 with a S m~ximllm at 351 nm in a nitrogen-rich em,ilunlllenl. The average ;Illen~ y was about 2.05 mW/cm2. res -ltin~ in a total energy of 650 mJ/cm2.
C~ u~ re c,.~lllple CS was prepared in the same way as cGIllp~Li~e ~ ~ ;....ple C4 except that a premix of 10 parts AA and 90 parts IOA was used. In addition, 0.12 parts triazine was used. Col--p~alh~e examp1e C6 was p~ ;d in 10 the same way as co...pa.~Li~e example C4 except that a premix of 14 parts AA and 86 parts IOA was used.
Peel and shear data for ~x~mple5 116-124 and comparative examples C4, C5, and C6 are set forth in Table III-4. The data was generated according to Test Procedures A2-III, B2-III, and C2-III.

WO 97/03144 PCT/U:,_5/.F~i9 ~., ,., X oo oo X oo X X X oo ~
A A A A A A A A A A A A
~) _ ~_ ~ O ''1 00 0 ~ r ~ o ~
c~ _ ~) cn ¢
~ O o ~ o, ~ ~ ~ ~ ~ o~

.S v~ O ~ Z Z t--~ ~ O O ~
¢ o ~- aZ Za aZ

~ V~ ~ -- O -- O 1-- ~ ~ ~o _ 1-- _ ¢ ~ t~ O -- ~ ~, ~t S

W O 97/03144 PCTrUS96/08369 Vibration D~..ping Adhesives Example 1 A composition was pl~alc:d by mixing 67 parts isooctyl acrylate, 32 parts isoboll.~l acrylate, 1 part acrylic acid, and 0;04 part benzil dimethyl ketal S pholo;~ or (KB-l from Sa.lol~le.). The mixture was partially polyl.,~ ed in a nitrogen rich ~tmosph~re using fluor~scel-L black lights to a syrup having a viscosity of about 3000 c~:..lip~ise. An ~d-litiQn~l 0.16 part KB-1 pholoillilialor and 0.15 part hexane dioldiacrylate were added to the syrup, which was then mixed and knife coated to a thicL n~se of about 50 microns onto a silicone-treated, polyethylene10 coated paper release liner. The coated mixture was exposed to ultraviolet radiation having a major portion of the spectral output between 300 and 400 nano~e~
with a maximum at 351 nano..lele-~, and at an intensity of about 2 milliWatts/cm2.
The total energy was about 650 milliJoules/cm2. The resulting sheet material wasthen l~min~ted to a 0.165 mm thick panel of cold rolled steel to form a col~sl~Lined 15 layer damper.
The consl-ained layer damper was cut to a dimension of 20.3 c~ntimet~rs by 20.3 c~ntim~ot~ors and l~min~ted to an automotive door panel. The door panel with the damper was suspended with Tygon tubing, and an accelerometer (Model 22 from Endevco Co., San Juan Capi~L~ ano~ CA) was attached to the door panel and 20 wired to a Fast Fourier Transform (FFT) analyzer (Model 2630 Analyzer from Tek~.o~ ). The analyzer was also aKached to an impact hammer (obtained from PCB, DePew, NY). In testing, the impact hammer was used to strike the panel, which caused various modes of excitation or vibration to occur within the panel.The acceleration was then measured as a function of time, and the FFT analyzer 25 was used to convert the results to acceleration as a function of frequency. The frequencies (FREQ) of the first eight modes were determined using STAR Modal software from Structural Measurement Systems, Milipitas, CA. The average loss factors (AVG) for all eight modes were also calculated.
In comparison, the test was also contl~cted on the same door panel without 30 a damper, and also with a commercially accepted damper (measuring 20.3 cm by CA 02224378 l997-l2-lO

W O 97/03144 PCT~US96/08369 20.3 cm) having 1.78 millim.ot~rs of a black mastic material on a 0.10 mm thick mim~m con~ ll"g layer. All ofthe test results are shown in Table IV-1.

Il TABLE IV-1 Mode F . 'e 1 No Damper Con~,.. elc,;~l Damper FREQ- LOSS FREQ- LOSS F~EQ- LOSS
HZ H'' HZ
61.8 0.01036 6:.5 0.00326 60.~ .002''2 2 76.0 0.00 00 ''5.9 0.00718 76. 0.00~6 3 99.1 0.00~50 99.5 0.00538 gs.~ 0.00 4 117.0 0.00630 : :6.9 0.0037 1 :9.4 0.00~1 ' 135.1 0.01512 1: 0.9 0.00674 130.7 0.0094"
6 140.0 0.02182 136.0 0.00502 136.3 0.01988 7 146.4 0.00608 142.5 0.00350 143.5 0.00--12 8 151.0 0.01614 148.6 0.00696 147.9 0.01~86 AVG --- 0.01142 --- 0.00522 --- 0.00"90 5 The data in Table 1 show that vibration damping composites, i.e., constrained layer danll)el ~, of the invention provide superior damping as colllpared to commercial products as shown by the greater loss factor.

Adhesives Collly~i:,in~ Electrically Conductive A~ents TEST METHODS
Shorted Configuration Resistance Test (SCRT) This test is a measure of the interconnect resistance in the adhesive bond. In this particular test, it is desirable that the resistance readings are less than about 20 15 Ohms per connection, and preferably less than 10 Ohms.
A 0.025 mm thick copper coating on a polyester flexible circuit (3MTM
Brand Heat Seal Connector without adhesive available from Minnesota Mining &
Manufacturing Co., St. Paul MN) is used in a four wire resistance set-up shown in Fig. 1. A bond is p,epaled by l~ ;.-g a 0.3 cm wide by 2.5 cm long strip ofthe 20 electrically conductive adhesive film 6 across one end of the polyester flexible circuit 2 to a printed circuit board 8 (FR-4 test circuit board). Alternatively, the adhesive can be screen printed or knife coated directly onto the flexible circuit. The CA 02224378 l997-l2-lO

W O 97/03144 PCTrUS96/08369 l~min~.tion is pelr~,.,.,ed either by hand pressure for a ples~.ure-sensitive adhesive, or by a hot bar bonder with a 3 mm by 25.4 mm thermode (TCW 125, from ~ughes Aircraft) for a heat activated adhesive. The flex is shorted to allow for resi~t~nce mea~.u. t;ln~ . by providing a solid copper pattern 4 on the flex as shown in Fig. 1.
S The bonded sample is tested for i"lt;,~ e-;l r~ciet~n.~.e by using the four-wire method using the principles des~,,ibed in ASTM B 539-90 such that the net r~ iS..-ce not due to the inlelcol~le-;lion is ...;..;...;,e~l to appr~ ely 150 rnilliOhms. The samples are tested after bonding (INIT) and after aging at 60C and 95% relative humidity for 10 days (AGED) and results are I e~oo~ led in Ohrns.
Jumper Configuration P~e~ict~nce Test (JCRT) This test is a measure ofthe electrical rçci~t~nce through two adhesive bonds and a con-lncting circuit. In this particular configuration, it is desirable for r~ci~t~.nre readings to average less than about l00 Ohms, and preferably less than about 20 Ohms.
A test sample in Fig. 2 is pl~paled by bonding a straight line 8 mil (0.2 mm) pitch flexible circuit 2 (3MTMBrand Heat Seal Connector without adhesive, available from Minnesota Mining & ~.mlf~cturing Co., St. Paul MN) between a printed circuit board 8 (FR-4 circuit board) and an ITO (indium tin oxide) coated glass plate 10 (20 Ohms/ square sheet resistivity, available from Nippon Sheet Glass, Japan). The adhesive can be pre-applied to the flexible circuit by screen printing or knife coating the adhesive onto the circuit or it can be applied as a film adhesive or adhesive ll~-lsrel between the flexible circuit and the circuit board and glass at the time of bonding. The circuit traces of the flexible electrical circuit are aligned to the colle~.~olldillg traces on the circuit board and bonded by hand pressure for a pressure-sensitive adhesive, or by hot bar bonded for a heat activated adhesive. Hot bar bonding is accomplished with a 3 mm by 25.4 mm thermode (TCW 125, from Hughes Aircraft) set at 145C and the indicated pressure for l0 seconds. Electrical resistance of the adhesive interconnection is measured using a four wire method acco,dillg to the principles described in ASTM B 539-90 such that the net re~ist~n~.e not due to the interconnection is ~ ed to ap~oloxi~llalely l50 W O 97/03144 PCT~US96/08369 milliOhms. Samples are tested after bonding (rNIT) and after aging at 60C and 95% relative humidity for 10 days. (AGED).

90~ Peel Adhesion This test is con~ eted by adhering a flexible electrical circuit with the adhes*e to either an FR-4 circuit board or to an indium tin oxide (ITO) glass plate having 20 Ohms/square sheet resistivity (available from Nippon Sheet Glass, Japan) by hand for a p~ u~ ~-sensitive adhesive, or using a 3 mm by 25.4 mm pulsed heatthermode (TCW 125, from Hughes Aircraft) set at 145C and 800 psi (5516 KiloPascals) for 10 seconds. The circuit board is mounted in a fixture in the lower jaw of an InstronTM Tensile Tester so that the flexible circuit, mounted in the upper jaw, would be pulled off at a 90~ angle. The width of the flexible circuit is 1.9 to 2.5 cm. The jaw separation speed was 2.54 millimet~rs per minute and results arerecorded in gramslcentimeter. Samples are tested after bonding (INIT) and after aging at 60C and 95% relative humidity for 10 days (AGED) and results are reported in gramslcçntim~oter (g/cm).

Example 1 A conductive pressurc-sensi~ e adhesive composition was pl el)al ed by mixing 67 parts IOA (isooctyl acrylate), 33 parts IBA (isobomyl acrylate), and 0.04 pph (part per 100 parts of acrylate and co-monomer) benzil dimethyl ketal (F~ç~cureTMKB-1 from Sartomer) in a glass jar, purging the jar with nitrogen, and exposing to ultraviolet radiation from fluorescent black lights which have at least 90% oftheir spectral output between 300 and 400 nanometers with a peak emission at about 350 nanometers until a viscous syrup having a viscosity çstim~ted to beabout 2000 to 3000 centipoise was fommed. An additional 0.16 pph benzil dimethylketal and 0.1 pph HDDA (1,6-h~oY~ne~iol diacrylate), and 20 pph silver coated nickel (20 to 40 micrometers available from Potter Industries) were added to thesyrup and mixed thoroughly. The syrup mixture was then knife coated to a thickness of 0.025 mm on a silicone release coated polyethylene coated kraft paper.
The coated mixture was then exposed, in a nitrogen rich atmosphere (less than WO 97/03144 PcT/u~ ~9 about 200 ppm oxygen), to ultraviolet radiation from lamps as described above, for 5 ~-,;--.-~es for form an electrically conductive pressure-sensitive adhesive film. The average h~lellsily of the lights was 3.9 milliWaKs/square c~ e~ (mW/cm2) as m~~ cd with a ,~dio~cler (EIT) acco.dil~g to the National Tn~titute of SLal~da~dTesting (NIST) units. The pressure-sensitive adhesive film was used to made a flexible circuit which was tested for conductivity (through a ,~ nce llledsulc;lll~n~) accol~ g to the Shorted Configuration ~ecict~nce Test, and test results are shown in Table V.

Example 2 An electrically conductive pressure-sensitive adhesive film was p-~pared as in Example 1 except that the syrup composition had 65 parts IOA and 35 parts IBA, and pph of silver coated nickel particles. The particles conetituted 30% byweight of the syrup composition. The resulting adhesive film was used to make a flex circuit which tested for conductivity according to both the Shorted Configuration R~eict~n~e Test and the Jumper Configuration Reciet~nce Test and results are shown in Table V-l.

Example 3 An electrically conductive pressure-sensitive adhesive film was prepared as in Example 2, except that 20 pph of a hydrocarbon tackifying resin (RegalrezTM6108 available from Hercules) were added to the syrup before coating, the amount of HDDA was 0.075 pph instead of 0.1 pph, 20 pph of sub- I I micrometer gold coatednickel particles (available from Potter Industries) were added instead of the silver coated nickel particles. The res--lting adhesive film was used to make a flex circuit using a heated bar set at 140C and 34.5 kiloPascals (5 psi) for 5 seconds to effect the bonding of the adhesive film to the flex and the board, and tested according to the Jumper Configuration Re~i~t~nce Test and results are shown in Table V-l.

CA 02224378 l997-l2-lO

W O 97/03144 PCT~US96/08369 Example 4 A heat bondable electrically conductive film was plepaled as in F.xi....ple 3 except that the syrup composition was 40 parts IOA and 60 parts IBA, with no tacLiryil~g resin. The nickel particles co~ ed 20% by weight of the syrup 5 composition. The adhesive film was heat bonded to a polyester flex and board and the flex circuit tested as in Example 3 and test results are shown in Table V-1.
Table V- 1 *
SCRT - Ohms/ JCRT - Ohrns Ex INIT AGED - HOURS INIT AGED - HOURS
3 5 - 285 ** **

3 ** ** 3 8 - 307 4 ** ** 2 10 - 307 $ Numbers indicate an average of 15 lead recict~nce re~-ling~.
** Not Tested The data in Table V-l indicate that the adhesives of the invention provide stable electrical connections.

Example 5 A heat activatable conductive adhesive syrup was prepared according to the procedure of Example 1 by partially pOl~llleli~illg 40 parts IOA, 60 parts IBA, 0.1 pph benzil dimethyl ketal photoinitator, and 0.04 pph carbon tetrabromide. An adhesive composition was prepared by mixing the syrup with 0.05 pph HDDA and 0.3 pph TPO pholoilliLiaLor (Lucirin TPO, available from BASF) until both were 20 dissolved. Then 4 pph fumed silica (Cab-O-Sil M5) and 20 pph conductive nickel spheres (CNS, air classified -20/+10 ~m available from Novamet, Inc.) were dispersed into the composition with a high shear mixer. The 20 pph of nickel spheres is 5% by volume of the adhesive composition. The adhesive composition was then screen printed onto a flexible electrical circuit (3MTM Brand Heat Seal W O 97/03144 PCT~US96/08369 Conl-e~ilol without adhesive, available from Minnesota Mining & ~mlf~lring Co., St. Paul, MN) using a flat bed screen printer (Model 2BS Roll to Roll Screen Press System from Rolt Fn~in~ering Ltd.) with a 200 mesh polyester screen with 31~ bias and 25 mil (0.635 mm) ~mll~ on ~ L ~ess and a 60 duron,eLel rounded 5 edge squeegee. The adhesive composition was printed in the print/flood mode with a squee~ee ~ r~ of 20 psi (138 kiloPascals), 20 inches per second sq-~ee.~e speed (50.8 cm/sec) and 20 inches per second (50.8 cm/sec) flood blade speed, and a .~ .. squeegee angle. The adhesive coating thi~l~n~ was 43 to 53 ,um.
The screen printed adhesive was cured by exposing the adhesive to fluolescel.~ black lights as described in Example 1 at an illlensily of about 4.5 to 5.5 milliWatts/square cçntim~t~?r~ and a total energy of about 335 to 350 milliJoules/square cçntimeter. The resulting adhesive was e~senti~lly non-tacky at room temperature but became tacky when heated to about 35C. The printed flexible circuit was tested for electrical r~Cict~nce and peel adhesion to both and 15 ITO glass substrate and to a F R-4 circuit board. Test results are shown in Table Example 6 A heat activatable conductive adhesive was prepared as in Example 5 except 20 that the amount of HDDA was reduced to 0.035 pph and the conductive nickel spheres were 2% cold coated conductive nickel spheres . The adhesive was then screen printed to a thickness of about 30 to 40 ,um on the ends of the circuit traces of a flexible circuit. The adhesive was then cured as described above. This curewas followed by an exposure to mercury arc lamps for an exposure of 1100 25 milliJoules/square c~-ntimet~r~ The portion of the flexible circuit that was not adhesive coated had been coated with a non-adhesive protective cover coat (Enplate, from Enthone-Omi, Inc.). The resulting flexible circuit was tested forelectrical recict~nce and peel adhesive as described above except that the bonding pressure was reduced from 800 psi (5516 kiloPascals) to 540 psi (3723 30 kiloPascals), and the AGED results reported are after 13 days of aging. Test results are shown in Table V-2.

CA 02224378 l997-l2-lO

W O 97/03144 PCT/u~ 3ç9 Table V-2 FY~mple 5 F.Y~mple 6 ~ INIT AGED INIT AGED
RESISTANCE
AVG- Ohms 2.3 9.8 2.2 12.1 M~ - Ohms 2.1 4.4 2.0 5.9 MAX- Ohms 2.6 18.0 4.9 20.6 Peel Adhesion Glass - g/cm 826 1176 617 1883 Board - g/cm1184 2836 834 1250 The results in Table V-2 show that the adhesives of the invention are suitable for coating on to flexible circuits to provide electrical comle-;lions. Other embodiments are within the following claims.

Claims (21)

1. A heat activatable adhesive comprising the reaction product of starting materials comprising:
(a) 25-97 parts by weight of an acrylic acid ester of a monohydric alcohol whose homopolymer has a Tg less than 0°C;
(b) 3-75 parts by weight of a non-polar ethylenically unsaturated monomer whose homopolymer has a solubility parameter of no greater than 10.50 and a Tg greater than 15°;
(c) 0-5 parts by weight of a polar ethylenically unsaturated monomer whose homopolymer has a solubility parameter of greater than 10.50 and a Tg greater than 15°C; and (d) an effective amount of an electrically conductive agent; wherein said adhesive is essentially nontacky at 20C and has a Tg of 30C or greater.

2. The heat activatable adhesive of claim 1, wherein said electrically conductive agent is selected from nickel, silver, copper, or gold particles.

3. The heat activatable adhesive of claim 1, wherein said adhesive has a Tg of 35C or greater.

4. The heat activatable adhesive of claim 1, wherein said adhesive has a Tg of 40C or greater.

5. The heat activatable adhesive of claim 1, wherein said adhesive has a Tg of 50C or greater.

6. The heat activatable adhesive of claim 1, wherein said starting materials are substantially solvent free.

7. The heat activatable adhesive of claim 1, wherein said starting materials comprise 0 parts by weight of component (c).

8. The heat activatable adhesive of claim 1, wherein said starting materials comprise isooctyl acrylate and isobornyl acrylate.

9. The heat activatable adhesive of claim 1, wherein said particles are spherical.

10. The heat activatable adhesive of claim 1, wherein said particles are gold-coated, silver-coated, copper-coated, or nickel-coated spheres.

11. The heat activatable adhesive of claim 1, wherein said spheres are metal, glass, or polymeric spheres.

12. The heat activatable adhesive of claim 1, wherein said particles are conductive nickel spheres.

13. The heat activatable adhesive of claim 1, wherein said starting materials comprise from 1 to 10 parts by volume of said electrically conductive agent.

14. The heat activatable adhesive of claim 1, wherein said starting materials comprise from 1 to 5 parts by volume of said electrically conductive agent.

15. The heat activatable adhesive of claim 1, wherein said starting materials comprise a crosslinking agent.

16. The heat activatable adhesive of claim 1, wherein said starting materials comprise a multifunctional acrylate crosslinking agent.

17. The heat activatable adhesive of claim 1, wherein said starting materials comprise less than 1 part by weight of a multifunctional crosslinking agent.

18. A tape comprising:
(a) a layer off the heat activatable adhesive of claim 1, and (b) a tape substrate.

19. The tape of claim 18, wherein said tape substrate is a plastic film and wherein a plurality of electrically conductive areas overlay the plastic film and underlay and contact said heat activatable adhesive.

20. The tape of claim 18, wherein no electrically conductive particle has a diameter greater than the thickness of the layer of heat activatable adhesive.

21. A process for preparing a heat activatable adhesive comprising the steps of:

(A) providing a solvent-free polymerizable monomeric or prepolymeric syrup comprising:
(i) 25-97 parts by weight of an acrylic acid ester of a monohydric alcohol whose homopolymer has a Tg less than 0°C;
(ii) 3-75 parts by weight of a non-polar ethylenically unsaturated monomer whose homopolymer has a solubility parameter of no greater than 10.50 and a Tg greater than 15°C;
(iii) 0-5 parts by weight of a polar ethylenically unsaturated monomer whose homopolymer has a solubility parameter of greater than 10.50 and a Tg greater than 15°C; and (iv) an effective amount of an electrically conductive agent; and (B) exposing said syrup to ultraviolet radiation to polymerize said syrup;
wherein said adhesive is nontacky at 20C and has a Tg of 30C or greater.