CA2192858C - A barrier material comprising a thermoplastic and a compatible cyclodextrin derivative - Google Patents

Abstract

A barrier film composition can comprise a thermoplastic web comprising a thermoplastic polymer and a dispersed cyclodextrin composition having substituents that compatibilize the cyclodextrin in the film. The thermoplastic/cyclodextrin film obtains substantial barrier properties from the interaction between the substituted cyclodextrin in the film material with a permeant. The substituents on the cyclodextrin molecule cause the cyclodextrin to be dispersible and stable in the film material resulting in an extrudable thermoplastic.
Such materials can be used as a single layer film material, a multilayer film material which can be coated or uncoated and can be used in structural materials wherein the thermoplastic is of substantial thickness resulting in structural stiffness. The cooperation between the cyclodextrin and the thermoplastic polymer provides barrier properties to a web wherein a permeant can be complexed or entrapped by the cyclodextrin compound and held within the film preventing the permeant from passing through the film into the interior of a film, an enclosure or container. The permeant can comprise a variety of well known materials such as moisture, aliphatic or aromatic hydrocarbons, monomer materials, off flavors, toxic compounds, etc.

Description

WO 96/00260 ~ ~ ~ '' ~ ~ ~~ PCT/US95/05999 A BARRIER MATERIAL COMPRISING A THERMOPLASTIC A1~'D
A COMPATIBLE CYCLODEXTRIN DEF;IVATIVE
Field of the Inventio;:~
The invention. relates o ~he~-rnoolastic polymeric compositions used as packaging mat:eria7_s with barrier properties. The thermoplastic barrier material can take the form of a barrier coating, a flexible film, a semi-rigid or rigid sheet or a rigid structure. The thermoplastic barrier materials cari al:>o take the form of a coating manufactured from an aqueous or solvent based solutlOI1 OY' suspension of thermoplastic film forming components containing as c:~r~e component, the barrier forming materials. Suc:n a film sheet or coating material can act as a barrier to a vari.et.y of permeants including water vapor; organics such a~~ al.iphatic and aromatic hydrocarbons, aliphatic and aromatic halides, heterocyclic hydrocarbons, alcoho~'ys, al.dehydes, amines, carboxylic acids, ketones, ethers, esters, sulfides, thiols, monomers, etc.; off flavoz:s and off odors, etc.
The thermoplastic barrier compositions of the invention can be extruded, laminated or molded into a variety of useful films, sheets, structures or shapes using conventional processing technology. Further, the monolayer, bilayer or multilayer films can be coated, printed or embossed.
Background of the Invention Much attention has been directed t.o the development of packaging materials in a film, a semi-rigid or rigid sheet and a rigid. container made of a thermoplastic composition. In such applications, they polymeric composition preferably acts as a barrier to the passage of a variety of F~ermeant compositions to prevent contact between ,e.g., the contents of a package and the permeant. Improving barrier properties i~; an important goal for manufacturers of film and thermoplastic resins.
Barrier properties arise frorz both the structure WO 96!00260 and tale composLtl~~ ~~ '',":.° T.d't''ria_ . TYle .'_r~2_'_- C~ ~l=c s~~~'ucurc _.__.. '.-~=° ~ T_,~s~~a,~i-~r~~.t~;° ~~- ~_"~e amorp~.ous nat',lr~ ~'hE'' ~!-!at' -:' ~d~ , '' h!=' aZ:.l..St:"'1'~~. r'_' 1a~'ar~ ~'',-:~oatlnaS Can aife.,r-;r D~.a'_"2:1~=.. ~~~.~=~:tie_:, ~?'r~ ba~-~'1-er _. property C~~ iTta:':~~.' 'llate~lal~ Bali be inc'.reaSed ~V uSlnCt liquid ..ry'c..a_ :~:- ~e ~~ye 1-:,.ng ,-,nlecula~- ~_echr_~~; 1 og,~~, , ax~~a.i.~.y oz-ient.nq materi.aa.s such as an e~hr'Ien~. T~-inyl alcohol fi-~.m; ~,r Ay~ ~.Waxially orienting ny~Io:u Films aru by using other uc~==fu1 st:-,.:c:tures. Ir.terna~ polymeric 0 strur_ture pan be ~~~,'stal ..:zed or ordered i.l a wav to increase tha resistance tc permeation of a permeant. r matPrl.av.. can n"-~ ~~~~.a~~-tad f~,:r the t'.nermoo~.astic o~~
packaging ..(-;oating, which p.reven~s absorptio:~ o' a permear t cn t-~ t ~,:=- barrier surface . The material can als,-~ be se='~ectec; _ pre~rent. the rranspcr; :;= the permeant through the barrier. Permeation that corresponds t~- Fick~s law arid non-Fickian diffusion has beer. observed . ~.:~erleral ~-a-~ , permeat ion is concentration and temperature dependent regarding mode of transport.
20 The permeation process can be described as a multistep event. ~~':i.rsr, collision of the permeant molecule w.th the p,-;lymer ~.s followed b~: serpti on into the polymer. Nex~, migration through the polymer matrix by random hops occurs and finally the desorption of the penetrant from the polymer r_.ompletes the prcJess. The process occurs tc eliminate an existing chemical concentration difference between the outside of tale film and the inside of the package. Permeability of an organic molecule through a packaging film consists of 30 two component parts,. tn~:~~ diffusion rate and solubility of the molect.zle i.r~ t:.he f:i_!rn. The diffusion rate measures how fast mo~ecule transport occurs through the film. It affects the ease with whicrl a permeart molecule moves wi.th~.n a polymer. Soiubilitv is a 3~ measure of the concentration of the permeant molecule that will be irv position to migrate through the film.
Diffusion and solubility are important. measurements of a WO 96/00260 ~ ~ ~ ~ ~ ~) ~ PCTIUS95105999 barrier film's performance. There are twc~ types of mechanisms of mass transfer for organic vapors permeating through packaging fi..lms: ca.r~_ilary flow and activated diffusion:. Capillary flow involves small molecules permeating through pinholes or highly porous media. This is of course an undesirable feature in a high barrier film. The second, called activated diffusion, consists o~: solubilization of the penetrants into an effectively non-porous film at the inflow surface, diffusion through the film under a concentration gradien~. (high conc~~ntral_ion to low concentration), and release from the outflow surface at a lower concentration. In non-porous polymeric films, therefore, the mass transport of a penetrant includes three steps - sorption-, diffusion, and desorption.
Sorption and desorption depend upon the solubility of the penetrant in the film. The process of sorption of a vapor by a polymer can be considered to involve two stages: condensation of the vapor onto the polymer followed by solution of the condensed vapor into the polymer. For a thin-film polymer, permeation is the flow of a substance through a film under a permeant concentration gradient. The driving force for permeation is given as the pressure difference of the permeant across the film. Several factors determine the ability of a permeant molecule to permE=_ate through a membrane: size, shape, and chemica_ nature of the permeant, physical and chemical properties of the polymer, and interactions between the permeant and the polymer.
A permeant for this application means a material that can exist in the atmosphere at a substantial detectable concentration and can be transmitted through a known polymer material. A large variety of permeants are known. Such permeants include water vapor, aromatic and aliphatic hydrocarbons, monomer compositions and residues, off odors, off flavors, perfumes, smoke, WO 96/00260 a ~ ;~ f'~ PGTIUS95/05999 ~',i ~ ~ _1 a

2 ~ °~ , r pes~iCi~es, ~'~~':i.c nQi..erials, etc. A tv~pical bar?-ie~-mate="la~. v0'llpr~-iSe;:~ :.,;.nq~e~ ~a"fe'_~ O~ 1~01.VmeT~, ,~ tVJc~:
layer coext.ruded r>~ :! ami.nated polymer film., a cca~ed ;_ monc.layer, bi~~ayer c:r mulny~ayer yilm h a~,-incne c~ mor~-~
_ coa~inas o:: a surface c;:- both surfaces cf the f~~lm or shee, .
The twc most widely used barrier polymers fc.~~ food packag;~ng are- eth,,r~~nt --~,-,~r~-3-~ alcohol copclymer~ ;EVOH
ethylene viny.:L acetate copolymers (EVA) and pol ;--~ inyl idene L hl cr ide ( PVDC i . Other usef ui thermoplas'~ics ir:~~'yude eth~rler_e acrylic materials inc-'~uding eth~,~l~ene acryli~~ acid, ethylene methacrylic acid, etc. Such polymers are available commercially and cffer some r~sista:~c.~e to permeation of gases, f savors, L_ aromas, solven's and most ~~hemicais. PVDC is also an excellent. barrier to moisture while EVOH offers very good processability and permits substantial use of regrind materials. EVOH copolymer resins are commonly used in a wide variety of grades having varying ethylene 2G concentrations. As the ethylene content is reduced, the barrier properties to gases, flavors and solvents increase. EVOH resins are commonly used in coextrusions with polyolefins, n}rlon or polyethylene terephthalate ;PET as a structural layer. Commercially, amorphous 2~ nylcn resins are being promoted for monolayer bottles and films. Moderate barrier polymer materials such as monoiayer polyethylene terephthalate, polymethyl pentene cr polyviny_. c:h:i.oride films are available.
Substantial attention is now directed to a variety of technolcaies fcw the improvement of barrier properties. The use of both physical barriers and active chemical barriers or traps in packaging materials are under active investigation. In particular, attention has focused an use of specific copolymer and 3J terpolymer materials, the use of specific polymer alloys, the use cf improved coatings for barrier material such as silica metals, organometallics, and WO 96/00260 2 ~ ~ 2 g J g PCTIU895/05999 other strategies.
Another important barrier technology involves the use ef oxygen absorbers or scavengers 'that are used in polymeric coatings or in bulk polymer materials.
Metallic reducing agents such as ferro,as compounds, powdered oxide or metallic platinum can be incorporated into barrier systems. These systems scavenge oxygen by converting it into a stable oxide within the film. Non-metallic oxygen scaverGgers have also bE=_en developed and are intended to alleviate problems associated with metal or metallic tastes or odors. Such systems include compounds including ascorbic acid (vitamin C) and salts.
A recent introduction involves organome=tallic molecules that have a natural affinity for oxygen. Such molecules absorb oxygen molecules into the interior. polymer chemical structure removing oxygen from the internal or enclosed space of packaging materials.
Packaging scientists are continuing to develop new polymeric films, coated films, polymeric alloys, etc.
using blends of materials to attain higher barrier properties. Many of these systems have attained some degree of utility but have failed to achieve substantial commercial success due to a variety of factors including obtaining barrier performance at law cost.
One problem that arises when searching for polymer blends or compounded polymeric materials, relates to the physical properties of the film. F'ilm~> must retain substantial clarity, tensile strength, resistance to penetration, tear resistance, etc. to remain useful in packaging materials. Blending unlike materials into a thermoplastic before film extrusion often results i.n a substantial reduction of film properties. Finding compatible polymer materials for polymer alloys, and compatible additives for polymeric materials typically require empirical demonstration of: compatibility and does not follow a clearly developed theory. However compatibility can be demonstrated by showing that the P~/US95105999 WO 96!00260 n ~~ ~L~..Jt r-, compounded ma~~s~-la_or;tair,.s ,~,.. improved bare i er qua~~:~
with ~ ~ttle s-eductic~n. in cla.~-~~.y, ~~-ocessabi~ity, or SC?-i:Ctl.lra~ prope?~t.lF'~ uSi.r:a ConVentiOnal test rr~pti-T.C~~.
ACCCrdingl,r', d sllbSt.arl~la~- Tleed °xlSts fC~~
de',Iel~~!T;e:l~
of ma:~el~-~alc that: ;vat,. bFr ~nco~.~porated int.c~ pclymeri=
material to =orm a oackagina thermoplastic having excellent barrier properties without any substantial ~~eduction ir. structarai properties.
1,~ Brief Discussion of the Invention ;_ have found -t;.at the t;ar~~ier properties of a thermoplastic oo~'lymer can be improved, without any important reduction ir: clarity, processability o-structural propert.i~=s, by forming a barrie~~ layer witt_ a __. dispersed cempa'lb~~~_..v cvclodextrin derivative in the polymer. ~ have developed two embodiments. The first comprises a barrier made using the thermoplastic technology containing the r_.yclodextrin derivative. The second, a coating made by casting a solution or suspension of a film forming polymer or polymer forming material combined with the cyclodextrin derivative to form a barrier layer. The cyclodextrin molecule withou~
a compatible substituent group is net sufficiently ~com~atible ir: the bulk material to result in a clear 2J usefu~~ barrier layer or packaging material. The compatible cyclodextrin derivative is a compound substantially free c:f an inclusion complex. For this ;~nvention the term "substantially free of an inc-~usion complex" means that the quantity of the dispersed cyclodextrin derivative in the film contains a large fraction having cyclodextrin rings free of a permeant in the interior of the cvclodextrin molecule. The cyclodextrin compound will be added without complex, but some compiexing can occur during manufacture from 35 polymer degradation or from inks or coatings components.
The internal cavity of the cyclodextrin remains unoccupied by any complexed molecule.

WO 96100260 ~ ~ ~ PCT/US95I05999 The cycl.odextrin derivative has a substituent group bonded to the cyclodextrin molecule that is compatible with the polymeric material. C:yclodextrin is a cyclic dextran molecule having six or more giuco:~e moieties in the molecule. Preferably, the cyolodextrin is an a-cyclodextrin (aCD), a ~3-cyclodextrin (aCD), a 'y-cyclodextrin (~yCl~) or mixtures thereof. We have found that the derivat:ization of the cyclodextrin molecule is essential for foaming a cyclodextrin material that can be effectively b:Lended into the thermoplastic bulk polymer material with no loss in clarity, processability or' structural or packaging properties. The substituents on the cyclodextrin molecule are selected t:o possess a composition, structure and polarity to match that of the pclymer to ensure that the cyciodextrin is sufficiently compatible in the polymer material. Further, a derivatized cyclodextrin is selected that can be blended into the thermoplastic polymer, formed into film, semirigid or rigid sheet or other rigid structural materials using conventional thermopla:~tic manufacturing techniques . Last:ly, we have found that. t:he cyclodextrin material can be used in forming sur_h thermoplastic barrier structures without any substantial reduction in structural properties. The film can provide a trap or barrier to contaminant materials from the polymer matrix and from the product storage and use environment.
Thermoplastic polymers used in manufacturing packaging film materials are typically products made by polymerizing monomers resulting from refinery processes.
Any refinery stream used in polymerizat:ic>n chemistry, contains residual monomer, trace J_evel refinery hydrocarbons, catalyst and catalyst by-products as impurities in the polymer matrix. Further, the environment in which materials are packaged after production, stored and used, often contain substantial proportions of contaminants that can permeate through a barrier film or sheet and can contaminate food or other PC'TlUS95105999 WO 96!00260 ,.
r ?5 ',-,, c i packaged ~ terns . ne:~idua~ poivmer T~-olatiies are complexed bt.~ d:ispP.z~ s W c vc-iode::triri ;_nt~ me 1 t.en _ '~i-r.
T
p:Jlymer usi.:~an ~_-:.~.Vrudel . _he res;~dents time __ mir.ir~;
time of CD and m ,_ten pcivmE:r ~~n the baz:rel ~;t __ _ extruder irlitiat.e~: ~-h~: complexatiori of residual polymer volatiles. W:v~:~'t,: environmental contaminants diffusina throng:: the pol vmev , uncomp sexed cyclodextri:n dispersed ,_ ,_ in the polymer: __ beg ~ eyed :....; reside, pct or. ~ ~- between t:~e pclyme~w mo~ec~~.~~ :~ chains, but in vaguely defined ~~'cavities between t~hF= polymer ,chains. As the permeant diffuses thrc::~uc~~~ .r.t~e polymer cr. a tortuous pate, the uncomplexed cyclodextrin is available to complex permeant moiecuies as they diffuse throuqh the film.
,mom= contirruacomylexataor and re-cease of_ trle same ___ guest between cy._~r~dext~-i.r: molecules in the film is poss;yb'~e. ~:: other words, the cyclodextrin dispersed i:~
the film is complexina anc: releasing. The diffusion rate may increase due to the number and size of the cavities caused b,~~ the presence of cyclodextrin. The modified cyclodextrin preferably has chemical properties that are compatible with the polymer and are of a size and shape that does nod. adversely affect the film's barrier property.
The benef;wcia~ effect of cyclodextrin over other ~= high-barrier film technologies is twofold. First, cyclodextrin has the ability to complex residual organic volatile contaminants inherent in all polyethylene and polypropylene packaging films. Secondly, cyclodextrin offers the unique ability to complex permeants that ma~,~
otherwise diffuse through the package film-improving product quality and safety.
Since all packaging films are permeable to organic vapors, measurir:a the amount that permeates through the filn~, over time is an important performance measurement of a particular pac~:aging film,. The permeation process described above i~~ fast far low-water-activity packaged food products ,crackers, cookies, cereals). The process W096I00260 2 '~ C~ ~ (~ J ~ PCTIUS95I05999 of permeation can be faster or sl~,~wer depending on the relative humidity outside the package and the product's storage temperature. As the relative humidity outside the package increase, the pressure differential between the outside and inside the package is greater. The greater the differential and/or th~r higher the temperature, the faster the organic permeants will diffuse through the film. The method used to test the film samples in this research used the worst case (600 relative humidity outside the package and 0.25 water activi~y inside the package) shel~-life storage conditions to accelerate the outcome of: the testing.
The organic permeant concentration used has been obtained from food products contaminated by inks used in printing on packaging materials, adhesive systems used in polymer or paper or foil laminations, or numerous environmental contaminants originating from gasoline, diesel fuel, paint solvent, cleaning materials, product fragrance, food products, etc. The relative humidity, water activity and permeant concentration have been used to test numerous high-barrier films presently used in the industry today. The testing has effectively demonstrated performance differences between various high-barrier films. Four test parameters are important in the performance of the high barrier film. First is the time it takes the permeant to begin diffusing through the package wall known as "lag-time", second, the rate the permeant diffuses through the film, third, the total amount of permeant that can pass through the film over a given time, and fourth, the effectiveness of the barrier to the permeant challenge.
Figure 1 is a graphical representation of the dimensions of the cyclodextrin molecule without derivatization. The a, ~i and 'y cyclodextrins are shown.
Figure 2 is a schematic diagram of the extruder used to form the films set forth in Table I.

WO 96/00260 ~ ~ ~ ~ ~ ~ ~ ~j PCT/LTS95/05999 .~
Figure ~ is ; diagran-: of a test deT.-ice use~ ~::
meas~;rina t:~ : ~:~erTn.eab:ili ~v ~;'~ she ~.~-~.m~ .'-. _ ~ nr inversions.
We have also ioura '~.r~at i nclusion ~~ the ~; , _. cyciodextrin derlt,~-atv.ves ~n the the~-mon~as~~.c maaeria~s of the invention can improve other properties cf the film, such as surface tension, static: charge properties and other properties cha_ improve the adaptability of this barrier mat~-~w~.<~1 to coating and prir.t.ing. 'x'he 1~ cyclodextrln derivative materl_als can ba ,'~ncluded in a variety of a ttnermo~alastic film. and steer.
Detailed Description of the Invention i~ !'ilm A film oz: a sheet is a flat unsupported section of a thermoplastic resin whose thickness is much smaaler than its width ar length. Films are generally regarded as being C.25 millimeters lmm) or less, typically 0.01 20 to 20 mm thick. Sheet may range from about ,..2~ mm to several centimeters (cm), typically 0.3 to 3 mm in thickness. Film or sheet can be used alone or in combination with other sheet, fabric or structural units through lamination, coextrusion or coating. For the 2J invention the term "web" includes film, sheet, semi-rigid and rigid sheet and formed rigid units. =mportant properties include tensile strength, elongation, stiffness, tear strength and resistance; optical properties including haze, transparency; chemical 3C resistance such as water absorption and transmission of a variety of permeant materials including water vapor and other permeants,° electrical properties such as dielectric consta:~t; and permanence properties including shrinkage, cracking, weatherability, etc.
'fhermopaastic materi.a:Es can be formed into barrier film using a variety of processes including blown thermoplastic extrusion, linear biaxially oriented film 21 ~2~~5~
1,~
extrusion and by casting from molten thermoplastic resin, monomer or polymer (aqueou:~ cr organic solven~i dispersion. rhe~;e methods are wea'~ knowm manufa~cturina procedures. The characteristics _~r: the polymer thermoplastics that lead to successful barrier' film formation are as follows. Skilled artisans manufacturing thermoplastic polymers have learned to tailor the polymer material fog- Thermoplastic processing and particular end use applicatiorn by controlling molecular weight (the melt index teas been selected by the thermoplastic industry as a ma:asure~ of molecular weight -- melt index is inversely proportional to molecular weight, density and crystalli.nity). For blown thermoplastic extrusion polyolefir~s (LDPE, LLDPE, HDPE) 1J are the most frequently used thermoplastic polymers, although polypropylene, nylon, nitriles, PETG and polycarbonate are sometimes used t..o mak.e b:Lown film.
Polyolefins typically have a melt index. from 0.2 to 3 grams/10 mins., a density of about 0.910 to about 0.940 grams/cc, and a molecular weight that can range from about 200,000 to 500,000. For biaxially oriented film extrusion the polymer most often used are olefin based -- chiefly polyethylene and polypropylene (,melt index from about 0.4 to 4 grams/10 mins. and a molecular weight of about 200,000 to 600,000). Polyesters and nylons can also be used. For casting, molten thermoplastic resin or monomer dispersion are typically produced from polyethylene or polypropylene.
Occasionally, nylon, polyester and PVC are cast. For roll coating of aqueous based acrylic urethane and PVDC, etc. dispersions are polymerized to an optimum crystallinity and malecular weight before coating.
A variety of thermoplastic materials are used in making film and sheet products. Such materials include poly(acrylonitrile-co-butadiene-co-styrene) polymers, acrylic polymers such as the palymethyl~metrlacrylate, poly-n-butyl acrylate, polyethylene-co-acrylic acid), WO 96100260 '7 ' a ~ ~ r ~ PCT/US95105999 _ ~ ~d '.~.~,~
poly(ethy-.~ene-co-methacrvlate', etc., cellophane, cell',ilOSlC.=',', ~nC: ,.,~~~',1::; C,°_1.1L;!OS'=~' acetate '~c'_,iL110S=
aCeta~e prOt~l;.'%rlcxr;_ , n~~~.~ l.l;.lOSe aCF'tc~t. a bl:~Vra~e an CElILilOSP_ trl~C~tate" a . , ~i'~lOrO~~~lymers in~1'.l~lnC1 _. pOlfTtetrafluO:OetnT.'iene t e'~ ~~ on.' , pOlfJ let~'1'Y'lene__r-n_ tet~-aflucroetn~'len~:: ~'op~~~'mer' , ~ ~~ti_aFl~uozoetnvl.ene-co- propylene ~opw.ivmers, polyvinyl _luoride polymers, etc . , polyamide~- ,u~t..~ a.iylon F, , n~..lon ~ , ~ , etc . , po~-y~carbonates; . -.~yesrer::, suc~; as po~_v;et_nyl.en~-co._ _. terephthaiate; , p:~~ ~,w,et'as,'lene-co-1,4--naphthalene dlCariOXy~~atv,' ; ~~"".y~ ~~'~tt,'1.eI:C--_'-C~~!-terep!:tilala'e,' polyimide materials; polyethylene materials including low density polyethylene; linear low density' pClVa~r?ylorl'., ..~C1I1 Cx,°_rI~?'~t~,' ';~Oiyat:'i'.'~ana, ~11C{~1 m.~.l~e,~_.Lla~-weig~~'_~ '.ig:'-'. densi ~ ' polyethylene , etc . , polypropylene , biaxially oriented polypropylene; polystyrene, biaxially or Tented polystyrene ; ~"inyl. films including poll>Z,r;~ny'~
ch~~oride, (vinyl chloride-co-vinyl acetate) copolymers, polyvinylidene chloride, polyvinyl alcohol, (vinyl 2C chloride-co-vinylidene dichl.oridel copolymers, specialty films including polysulfone, polyphenyiene sulfide, polypher~ylene oxide, liquid crystal polyesters, polyether ketones, polyvinylbutyrl, etc.
~w~~m and sheet materials are commonl~~r manufactured 2~ using thermoplast.c techniques including melt extrusion, calendaring, scl~ution casting, and chemical regeneratio:~_ processes. IrI many manufacturing steps an axial or a biaxial orientation step is used. The majority cf film, and sheet manufactured us~wng melt extrusion techr_iques.
~.«;; In mel t extrusion ~:~Ie material is heated above its melting point _iIan extruder typically having an introduction sectiol~ ~'?, a melt region 28 and an extruder sectiorl ~W . The melt is introduced to a slot die resulting in a thin flat profile that is rabidly 35 quenched to so'rid state and oriented. Typically the hot polymer film after- extrusion is rapidly chilled on a roll or drum or using an a,~r stream. Ultimately, a 2192~j8 quenching bath can be used. Thermoplastic materials can also be blown. The hot melt polymer is extruded in rr~ig.
2 in an annular die 22 in a tube form 21. The tube is inflated with air (see air inlet 25) to a diameter S determined by the desired film properties and by practical handling considerations. As the hot melt polymer emerges from the annular die, the extruded hot tube is expanded by air to 1.2 or four (4) times its initial die diameter. At the same time the cooling air (see air flow 20) chills the web forming a solid extruded with a hollow circular cross section 21. The =ilm tube is collapsed within a V-shapes frame 23 and is nipped at the end of the frame (nip rol'_s 24) to trap air witin the thus formed pubble. Rcll~ 24 and 25 draw S the film from the die maintaining a c;nt_.nuous production of the extruded tube.
We have found that in the preparation of biaxially oriented film and in the production of ~,_.own thermoplastic film that =he melt tempera~.ure and the die temperature are important in obtaiT:ing t=ie per;neabilityr or permeant transmission rates preferrec for,films of the invention, to raduce melt fracture and to impr:,ve Liim ur_iformity (reduce surface cefects) . Referri g to figure 2, the temperature of the -ne,~._ at the melt region 28 should range from about 390-420°F ';?a8-216°C!, preferably 395-415°F (202-213°C). The temperature of the extrusion die 29 should range from about 400-435°F
1204-224°C), preferably 410-430°F (210-221°C). The extruded polymer can be cooled using ambient water baths or ambient air. The extruder can be operated at through put such that production rates can be maintained but the polymer can be sufficiently heated to achieve the melt and die temperatures required. production of the films of the invention at these temperatures ensures that the cyclodextrin material is fully compatible in the thermoplastic melt, is not degraded by the high temperatures and a clear compatible use=ul barrier film ~~ii~'~~''_~': ~.~=
Ll :;,,~,r v,! L.

2192~~~
is produced.
Often two thermoplastic materials are joined in a coextrusion process to produce tailored film or sheet products adapted to a particular end use. One or more S polymer types in two or more layers of melt are coextruded in a coextrusion die to have a film with versatile properties dried from both layers. Layers of the different polymers or resins are combined by either blending the materials in melt before extrusion or by parallel extrusion of the different thermoplastics. The melt flows laminarly through the die and onto a quenched drum. The film is processed conventionally and may be orient'd after coolina. ~ilrns can contain a ~rar=etv of additi-res such as antioxidants, zest stabilizers, ~.T
~5 stabilizers,. slip agents, fillers, and anti-block aaents.
The barrier layer of the invention can be made by castina an aaueous dispersion or solvent discersior_ or solution of a film formilg polymer and ti_e cyclcdex~rin derivative. The aqueous or solvent based materia'~. can be formed by commcnly available aaueous or sclven.'_ based processing of commercially available polY-mers, pclvmer dispersions, polymer solutions or both polymer and common aqueous or solvent processing technol:,5y. The cyclcdextrin derivative material can be combined with such aqueous or solvent based dispersions or sclutions to fcrm a film forming or readily .formed coating material. Such barrier layers or barrier comings can be formed using commonly available coating t'chnology including roller coating, doctor blade coating, spin coating, etc. rdhile the coatings can be made and removed from a preparative surface, commonly coatings are formed on a Thermoplastic or thermosetting polymer web, and remain in place to act as a barrier layer on a 3S polymeric web used in a packaging. The typical coatings can be made from the same thermoplastic polymer materials used in film sheet or other structural layers w a ~r~,.-.-~ C~~!_rT
,~:'i:L.-... _.. --" ... ,. _ ,. .,,..,."M..~,.,w"~". ..~, ~..w.""~"".~,",~.....,.w..,.. ....",_ . . " .,w,.N .,-.".."~.""" ".....".,...,. ._..., m "..". ,.,.w. ..",._.
,~~..,.,_"......."..,.......~,.,.".._.

21~2g~g ._ using substantially similar loadings of the cyclodextrin derivative material. The barrier lager or ar=ier coatings formed using the film forming palymer and the cyclodextrin derivative can be used as a single coating 5 layer or can be used in a multiple coat_ng structure having a barrier layer or coating on one or both sides of a structural film or sheet which can be used with other coating layers including printing layers, clear coating layers and other layers con~rent=anal in .0 packaging, food packaging, consumer wrccuct packaging, etc.
Cvclodextrin ~, "' ' n'~=_..._ :n COnta7.n 3 The t_:eralODiaStlC films Of t.~e _ .5 cyclodextrin having pendent moieties .._ ~~ubst_=cents that render the cyclodextrin materiaW 'cmpatible with the thermoplastic polymer. ror thi= _Tv=__~_ticr_, compatible means that the cyc'~.edext== = ~:at'=ial can be uniformly ~iscersec. _ nto the melt pcl:r-::e_-, ....__ retain the abiiit~~ tc trap cr complex perinea= t .:~ateYia_s or polymer impur ity, and can reside in ._=a rcl_~r-ne= withcut substantial reductions i n polymer «_... ~ ha=acteYistics .
Compatibility can be determined by ~~easwrinc aclymer characteristics such as tensile st_ec-=, _sa=
resistance, etc . , permeability or t=as,:~::ss' :,n rates =cr permeants, surface smoothness, clarir:r, arc. Nan-compatible derivatives will result = n s~: startial reduced polymer properties, very hic . = e~'-neab-1 ity or transmission rates and rough dull f'_l:n. Qualitative compatibility screening can be obtained y preparing small batches (100 grams-one kilogram c_ thermoplastic and substituted cyclodextrin). The ble__~_ded material is extruded at production temperatures as a li=ear strand extrudate having a diameter of about cr_~ to five mm.
Incompatible cyclodextrin materials w-_11 .net disperse uniformly in the melt and can be seen ._. the transparent melt polymer immediately upon extr~.aic: from the ~!i~ii~r'.i':;W~ C' _.

2 v 92ac~a extrusion head. We have sound the incombatible cyclodextrin can degrade at extrusion temperacur~s and produce a characteristic "burnt dour" odor in an extrusion. Further, we have found that incompatible cyclodextrin can cause substantial melt fractura in the extrudate which can be detected by visual inspection.
Lastly, the extrudate can be cut into small pieces, cross-sectioned and examined using an optical microscope to find incompatible cyciodextrin clearly visible in the thermoplastic matrix. Cyclodextrin is a cyclic oligosaccharide consisting of at laast s_x glucopyrancse units oined by a ( 1-~a ) linkages . ~lthouch cyclodextr_n Ni t:2 uc to twelve glucose r?s:idues are :~newr_, t:ze three -nest ccmmcr_ _S hcmologs to ~yclodextrin, ~3 cyclodextrin ar_d cyclodextrin) having b, 7 and 8 residues have peen used.
C_rclodextrin is produced by a highly se'_=ct_ve ~TlZJmat_C ST~Tlt_leSl.-a. 'T'~iey CCnS? t C= Sl:~, Se'ie,- ',r 2u eight glucose monomers arranged i._ a ~ onut s~:aced r i ng, which are denoted x, ~3, or ~f cYc=odextri:~ =~. ective'~y (See -T ; gur° , ! . '"he specific coup._nc of t~e =~ ~~cose monomers gives the cyclodextr'_n a ~i~id, t=~~neared conical molecular struct~~re with a hollow inte--or of a 25 seecific volume. This internal cavity, which '_s lipophilic (i.e.,) is attractive to hydrocarbon materials (in aqueous systems is hydrophobic] when compared to the exterior, is a key st=uctural =eature oz the cyclodextrin, providing the ability to compl'x 30 molecules (e.g., aromatics, alcohols, halides and hydrogen halides, carboxylic acids and their esters, etc.). The compiexed molecula must saris=y the size criterion of fitting at least partially into the cyclodextrin internal cavity, resulting in an _nclusion 35 complex.
qi~ll Z ~; ~ L'1 C'lr_ C' WO 96/00260 ~ ~ ~ ~ ~ ~- ~ PCTlUS95105999 1- ?
CYCLODEXTRIN TYPICAL PROPERTIES
PROPERTIES CL's cx--CD ,~-CD 'y-CD
Degree of Polymerization r; 7 g in _ 1 Molecular Size (A°) inside diameter 5.'7 7.8 9.5 outside diameter 13.'7 15.3 16.9 heiqht 7.0 7.0 7.0 Specific Rotation [a)r +150.5 +162.5 +177.4 Color of iodine complex Blue Yellow Yellowish Brown Solubylity in wager (g/200 ml) 25°C'.
Distilled Water 14.50 1.85 23.20 The oligosacchari.de ring forms a. torus, as a truncated cone, with primary hydroxyl groups of each glucose residue lying on a narrow end of the torus. The secondary glucopyranose hydroxyl groups are located on the wide enC. The parent cyclodextrin molecule, and useful derivatives, can be represented by r_he following formula (the ring carbons show conventional numbering) in which the vacant bonds represent the balance of the cyclic molecule:

4 R2 ~1 R,.Primary Hydroxyls 37--~z0 R7=Secondary Hydroxyls n ~~~~'~i wherein R- and ~ a~-a urimarv or secondary W.,-drcx.~.~~: as s:~ow:z .
~'1.:J~F,?..,_, 1.: 'T~'' ! :':-'l: ~ <>c' _'7aVe a~.T~?'~.ra~~e Wi=~~
_'~a~'=i~':-.
wits a .chP~~,~~_~-===ager_'= -ha ~:rimary hyd~-o~ .:-.a a ~ ~.l~e s~~:_ _. pos=~ticn, o~ =;.,,F: ,y .u~,os~ mc'; ety, and at: t:n~ secondary.
hydroxyl _.°~ th~= t-=,~.., ama ~'aree poss..t ion . Because of +uhe geometry of the ,cyc:.~.:~dextri..r~ molecule, and the chemistr-_.j of t:ne ring substituents, all hyd~-ox~.~,~ groups are not equal. in reacti~ri~. However, with care an~,~ affe~=rive reaction condt ion; , she ecycl.odextrin molecul a c,an be raacted to obta~! ,_a dey_ivat ized molecule hay inq ail .:yd~-ox~,-1 groux>>;: d.~: z :~.v~~ ti zed w:~ t:;n a s ~ ngle subst i tuen t -.vie. Suc-; ::z derl-,-~,tive i s a persuf;stit~.~ted c1'cl~~dextw~~__. '~.'i'=.'-~dext~~~r! with selected subst-tuents _. ._, y . a . ' subs i tut ~ c~r~:L~r' on t~h~,~ pri.mary hydroxy~~ ~:;;__ seiectivel~,~ subst~_t~,.zted onl.~l~~ at. one or both r~he secondary hydroxyl groups can also be synthesized if desi red. T~'u.rt:ner di.recte d synthesis of a derivatized mc~lecuie with Ywo different: substituents or three different substituents is also possible. 'these subst.ituent~: can :>r~ p"~acec3 at random or directed to a specific; ha~fdx~cxyl.. For the purposes of this invention, the cy~clodextrir~ molecule needs to contain sufficient ~~hermoplasti~~ c:ompat:ible substituent groups on the molecule tc: insure- that the cyclodextrin material car. be uniformly dispersed into the thermoplastic and when formed int _: a c~:l..ea~~ :f ilm, sheet or rigid structure, does not detrac.' from the po.:l.ymei: physical properties.
Apart from the ir_troductior~ of substituent a~woups C on the ~D l:vdrox~,~. c:~ther molecule modif i canons carp be used. Other carbohydrate molecules can be incorporated into the cyclic backbone of the cyclodextri.n. molecule.
The primarf~ hydroxsvl car! be replaced using SN
displacement, oxidized dialdehyde or acid groups can be formed for further reaction with derivatizing grcups, etc. The secondary hydroxyls car.. be reacted and removed leaving an unsaturated group to which can bP added a WO 96/00260 Z ~ ~ L ~ J ~ PCTlUS95/05999 variety of l~:nown reagents t:~at ca.n add or cross a double bond to form a derivatized moler_ule.
Further, one c;r rnare Tina oxygen of the glycan moiety can be opened ~o produce a reactive site. These techniques and others can be used to introduce compatibiiizing substituent groups on the cyclodextrin molecule.
The preferred preparatory scheme for producing a derivatized cyclodextrin material having a functional group compatible with the thermoplastic polymer involves reactions at the primary or secondary hydroxyls of the cyclodextrin molecule. Broadly we have found that a broad range of pendant substituent moieties can be used on the molecule. These derivatized cyclodextrin molecules can include acylated cyclodextrin, alkylated cyclodextrin, cyclodextri.n esters such as tosylates, mesylate and other related sulfo derivatives, hydrocarbyl-amino cyclodextrin, alkyl phosphono and alkyl phosphato cyclodextrin, imidazoyl substituted cyclodextrin, pyridine substituted cyclodextrin, hydrocarbyl sulphur containing functional group cyclodextrin, silicon-containing functional group substituted cyclodextrin, carbonate and carbonate substituted cyclodextrin, carboxylic arid and related substituted cyclodextrin and others. The substituent moiety must include a region that provides compatibility to the derivatized material.
Acyl groups that can be used as compatibilizing functional groups include acetyl, propionyl, butyryl, trifluoroacetyl, benzoyl, acryloyl and other well known groups. The formation of such groups on either the primary or secondary ring hydroxyls of the cyclodextrin molecule involve well known reactions. The acylation reaction can be conducted using the appropriate acid anhydride, acid chloride, and wel:L known synthetic protocols. Peracylated cyclodextrin can be made.
Further, cyclodextrin having less than all of available CA 02192858 1996''11 r j t, :_, y hydroxyls subst;~~.uted with suc~l groups car. b..e maa-= w,.':.ti-:
one c_. more .~~f th~~ balan:~-=' e~ ~-h~ a,.;-ailabl _ by dr.~~xW._, substituted wit:-~ ;~-;tner- functional ctroups.
Cvclcdext~-.~rv :r:ate~~i alu can aisc: be reacted wit'_~
= alkylating agents t~::~ produced an al.kylated c~yclcde~arir_.
Alkylating group; can be used to produc= pox°alky.~ated cvciodextri:~ ~sinc; .L:Lffs.cient reaction. conditions exhaustively rea-.~_~ available hydrox~.~1 groups wi.t~~ tl~:a a-~k~~-patina agent . '~'urthe~.-, depending on the alk~"~_atina agent, the cyclodextr;~ri molecule used i:_ the reaction conditions, cy,::lode::tri.r: substi tuted at less tha=-. all cf t::e avai.lab:l..-: rnydroxyls can be produced . Typica.
exampi.es e. alkyl groups useful in .formina the a l kyl ated cyclodextrin ~.nc.l.uda methv:i, propyl., benzy.~, isopropyl, ter Liar 1~ butyl , alljl , t~-ity~ , alkyl-benzyl and otneT-common alkyl groups. Such alkyl groups can be made using conventional preparatory methods, such as reacting the hydroxyl gz°oup under appropriate conditions with an alkyl halide, or wi.t.h an alkylating alkyl sulfate reactant.
Tosyli4-methylbenzene sulfonyl) mesyl ;methane sulfonyli or other related alkyl or aryl sulfonyl forming .reagents can be used in manufacturing compatibilized cyc:Lodextrin molecules fo r use in thermoplastic resins.
The primary -OH groups of the cyclodextrin molecules are more readilt~ reacted than the secondary groups.
however, the molecule can be substituted on virtuallzr any position to form useful compositions.
_3:~ Such sulfony:~_ containing functional groups can be used tc derivatize either of the secondary hydroxyl groups or the primary hydroxyl group of ar_y of the glucose moieties ir~ the cyclodextrin molecule. The reactions can be conducted using a sulfonyl chloride ~':.~ reactant that can effectively react, with either primar,r-or secondary hydroxyl.. The sulfonyl chloride is used at appropriate mole ratios depending on the number of WO 96100260 ~ ~ ~ i~ ~ ~ ~ PCT/US95/05999 target hydrcxyl groups in the molecule requiring substitution. Both symmetrical (p~~x~ substituted compounds with a singe sulfonyl moiety) or unsymmetrical (the primary and secondary hydroxyls substituted with a mixture of groups including sulfonyl derivatives) can be prepared using known reaction conditions. Sulfonyl groups can be combined with acyl or alkyl groups generically as selected by the experimenter. Lastly, monosubstituted cyclodextrin can be made wherein a single glucose moiety in the ring contains between one and three sulfonyl substituents.
The balance of the cyclodextrin mo:Lecu:le remaining unreacted.
Amino and other azido derivatives of cyclodextrin having pendent thermoplastic polymer containing moieties can be used in the sheet, film or cont<~iner of the invention. The sulfonyl derivatized cyclodextrin molecule can be used to generate the amino derivative from the sulfonyl group substituted cyclodextrin molecule via nucleophilic displacement of the sulfonate group by an azide (N3-1) ion. The azido derivatives are subsequently converted into substituted amino compounds by reduction. Large numbers of these azido or amino cyclodextrin derivatives have been manufactured. Such derivatives can be manufactured in symmetrical substituted amine groups (those derivatives with two or more amino or azido groups symmetrically disposed on the cyclodextrin skeleton or as a s~srmmetrically substituted amine or azide derivatized cyclodextrin molecule. Due 3C to the nucleophilic displacement reaction that produces the nitrogen containing groups, the primary hydroxyl group at the 6-carbon atom is the most likely site for introduction of a nitrogen containing group. Examples of nitrogen containing groups that can be useful in the ~5 invention include acetylamino groups (-NHAc), alkylamino including methylamino, ethylamino, butylamino, isobutylamino, isoprapylamino, hexylamino, and other WO 96!00260 ~ ~ ~~ ~ ?~ ~ ~ PCTIUS95105999 al~:lv'laml_l: Sl;ik:S~_._:l.lr~i:'.u. T:':~= atT'~n0 Or a~kyiaf'llrl:::
subst_teenr..~ ca~_ ~:z~-'~hez~ b= a-ea~ctive with other .:~~~'"sounds r:hat react v,~itn vi-:e ::,.troQer~ atom: t _. W -.~-~ne~~
derivatize the ami:~~ ~~roup. Ot:ner possible =it~~sae~:
_ containing subst:i;~~.z~~r.~s ~.nw:~ude dial:~:ylaminc_; such as dirnethylamin:., diet.~~:y_amin:v:, piper-idinc,, piper-iz~~no, quaternary substituted alk~,-1 or aryl. ammonium ch::o~-ide subs~ituenLs, t~aiouen derivatives of cyclodextrins car:
be manufactured as a feed stock for the manufacture of ..
1':~~yclodextr;~ru molecule subst~.tuted with a compatib,~,.~izin~
dehivative . ir: Su:t~ ~OmpO::Ilds the primary Or SeCOndar'J
hydroxyl groups az:~~_- r~ubst.:~_ru.-.ed with a halogen arou~
such as ~.y~n~_c~;, =r~.c:c-~ , b~v:~m:_,, ~od~: cr other substituent4. Th~~~ most likely position. fc=~ halogen substitution i:J t:~~~ primary hydroxyl a~ the ~~-position.
Hydrocarby~ substituted phosphono or hydrocarbyl substituted phosphate groups can be used to introduce compatible derivat:i..ves onto the cyc.lodextrin. At the 2'.'' primary hydroxyl, the cyclodextrin molecule can be substituted with alkyl phosphate, aryl phosphate groups.
The 2, and :~, secondary hydroxyls can be branched using an alkyl phosphate group.
The cyc:lodextrin molecule can be substituted with .J_ heterocyciic nuclei including pendent imidazole groups, histidine, imidazole groups, pyridine and substituted pyridine groups.
CyclodextrW derivatives can be modified with sulfur containing functiona_L groups to introduce

3~ compatibilizing substituents onto the cyclodextrir.
Apart from the su::tany.'~ acyl_ating groups found above, sulfur containing groups manufactured based orl sulfhydryl chemistry can be used to derivatize cyclodextriri. 5ucta sulfur containing groups include ~5 methylthio -SMe, propylthio ~-SPr), t-butylthio (-S-C(CH,) :) , hydroxyethylthio (-S-CH-,CH~OH) , imidazolylmethvithi.o, phenylthio, substituted WO 96/00260 ~ ~ ~ ~ ~ l ~ PC'T/US95105999 phenylthio, aminoalkylthio and ot't~ers. Based on the ether or this>ethex~ chemistry seat ~ ortri above, cyclodextrin having substituents ending with a hydroxyl aldehyde ketone or carboxylic aci:~ furxctionality can be prepared. Such groups include hydroxyethyl, 3-hydroxypropyl, methyloxylethyi am corresponding oxeme isomers, formyl methyl and its oxeme isomers, carbylmethoxy (-O-CH,--CO:Hi , car byi.methoxymethyl ester (-O-CH~CO -CH_,) . Cyclodextrin with da_rivatives formed using silicone chemistry can contain compatibilizing functional groups.
Cyclodextrin derivatives with functional groups containing silicone can be prepared. Silicone groups generally refer to groups with a single substituted silicon atom or a repeating silicone-oxygen backbone with substituent groups. Typically, a significantly proportion of silicone atoms in the silicone substituent bear hydrocarbyl (alkyl oz- aryl) substituents. Silicone substituted materials generally have increased thermal and oxidative stability and chemical inertness.
Further, the silicone groups increase resistance to weathering, add dielectric strength and improve surface tension. The molecular structure of the silicone group can be varied because the silicone group can have a single silicon atom or twa to twenty silicon atoms in the silicone moiety, can be linear or branched, have a large number of repeating silicone-oxygen groups and can be further substituted with a variety of functional groups. For the purposes of this invention the simple silicone containing substituent moieties are preferred including trimethylsilyl, mixed methyl-phenyl silyl groups, etc. We are aware that certain ~3CD and acetylated and hydroxy alkyl derivatives are available from American Maize-Products Co., Corn Processing Division, Hammond, IN.
Packages and Packed Items WO 96100260 ~ ~ ('~ ~ ~~ r-, r~ pCT/US95/05999 ? t, The thermoplastic containing t:re compatible zerivatiza~ ~ ~.~~:~.oci~.xtr~r,. c: an be usad i.r: a -:-ar ~ atv cf packaaing formats t--:; package a var,~.ety ef ,~tems .
:~eneral ~ackaainc~ ideas can be used. Fcr example, the items can be pac:kaaed :ervr_~wrei.i~ ir~ a film pouch, bag, etc. Furthev:, r.~he filrc r_~an be used as a film :.,yosure ~°:
a rigid plastic cor~tainer_ Such containers can have a rectangular, cir~::~.~la~ , sauarfe or other shaped cross-sect,~on, a f:ia' h,-:tto,~,., ancan open top. The cor.,taine,..
1.~: and a thermoplasti_~ f. lm cl osure car be made ~:~f tre ~he~~mcplast~.. rnater~a'~~ ci the :irwention. Further, the thermeplast.ics -cf the invent_icn can be used in the formation ~f: blister pack packaging, clam shell type enclosures, tu:, gray, etc. r;enerally, two product 1_> types require packar~inct .~ri thermoplastic film cf the inver~ticn ~avir:g substantial barrier properties. In onA
product type, protecting tree product from contamination from oermeant sources outside the packaging material is important. Protecting food items from contamination by 2~.~ aromatic and aliphatic hydrocarbons, fluorocarbons, ink and packaging residue, ex_naust from transportatior_ equivalent and ether internal combustion engines, perfumes commonly used in a variety of consumer products suc_: as scented paper products, bar soap, scented bath prod;zcts, cleaners, fabric softeners, detergents, dry bleaches, disinfectants, etc. All food items ara the most common material requiring protection from outside contamination, r~thex° items can be sensitive to odors.
Further, a variety of materials must be packaged in 3~ barrier materia-~s preventing the odor of the material from. exiting the package. A large variety of food odors are readily r_ransmit.ted b~.~ a variety of packaging materials. Suc=~ food odors can attract insect and rodent pests, ~~an be objecr_ionable to customers or employees oY caru :G-esu.z.: t i~ the substant ial. loss of important fragrance :notes from packaged materials reducing product value. important odors rea_uiring WO 96/00260 21 ~ ~ ~ ~ ~ PC"T/C1895/05999 substantial barriers include odors derived from coffee, ready to eat cereal, frozen pizza, cocoa or other chocolate products, dry mix gravies and scups, snack foods (chips, crackers, popcorn, etc.), baked foods, dry pet food (cat food, etc.), butter or butter-flavor notes, meat products, in particular butter or butter-flavor notes use;i in the manufacture of microwave popcorn in microwaveable paper containers, fruits and nuts, etc.
The above a}:planation of the nature of the cyclodextrin derivatives, thermoplastic films, manufacturing detail regarding the production of film, and the processes of cyclodextrin to make compatible derivatives provides a basis for urder:~tanding technology involving incorporating compatible cyclodextrin in thermoplastic film for barrier purposes.
The following examples, film preparation and permeation data provide a further basis for under:~tanding the invention and includes the best mode.
After our work in producing derivatives of cyclodextrins and compounding the cyclodextrins in thermoplastic films, we have found that: the cyclodextrins can be readily derivatize:d using a variety of known chemical protocols. The cyclodextrin material can be melt blended into thermoplastic materials smoothly resulting in clear extrudable thermoplastic materials with the cyclodextrin materials uniformly distributed throughout the thermoplastic. Further, we have found that the cyclodextrin derivatives can be combined with a broad variety of thermoplastic films.
The cyclodextrin materials can be incorporated into the films in a broad range of cyclodextrin concentrations.
The cyclodextrin containing thermoplastic materials can be blown into films of varying thi..ckness and can be blown free of melt fracture or other film or sheet variation. We have found in our experimentation that the barrier properties, i.e, reduc:tion in transmission 2192858 ...

rate of aromatic hydrocarbons, aliphatic hydrocarbons, ethanol and water vapor can be achieved using the cyclodextrin derivative technology. We have also found that the use of cyclodextrin materials improve the S surface properties of the film. The surface tension of the film surface and surface electrical properties were also improved. Such a result increases the utility of the films of the ir_vention in coating, printing, laminating, handling, etc. ~n initial work we have also 7_0 found (1) several modified cyclodextrin candidates were found to be compatible with the ~LDPE resin and provide good complexation of residual LLDPE voatile contaminants as well as reduce organ,_c permeants diffusing th~cugh the film. !2) .7nmod;fied ,t3CD
adversely affects transparency, thermal stability, machinability, and carrier properties of the fi'_m.
Conversely, selected modified 3CD (acetylated and trimethylsilyl ether derivati~res) have no affect on t=ansparencyr and thermal stability. The machinabi~.ity ~;0 0~ the extruded piast'_c material is effected somewrat causing some suryace defects, thereby re~.ucing t:ze barr=°_r proper ryes ~~z the fil m. (3 ) ; ;lms containi= a a modified ,aCD composition (1% by weight) reduce aromatic.
peYmeants by 3~% at 72°F and 28% at _05°F (40.~°C~;
~,S aliphatic permeants were reduced by only 90 at 72°~
(22°C). These results would improve significantly ._ worst case shelf-life testing conditions were not used to test the films. (4) Complexation rates were different for aromatic and aliphatic permeants. Films ~0 containing modified aCD had better comple:xation rates for aromatics (gasoline-type compounds) than aliphatic (printing ink-type compounds). Conversely, film coating had significantly better complexation of aliphatic compound than aromatic compounds. ~:S) ~3CD containing ac~~rlic coatings were the star performers reducing aliphatic permeants from 46% to 88%, while aromatics were reduced by 29%.
r',ll~~~ ~.~ .-Af4ic:.~~~ ._.~~~ , 2 i ~32~~~
L i QUALITATIVE PREPARATION
Initially, we produced four e~;periment=al test films. Three of the films contained ,C-cyclodextrin ,BCD
at loading of lo, 3~ and 5p lwt./wt.while the fourth was a control film made from the same batch of resin and additives but without yCD. The 5° loaded ~3CD film was tested for complexation of residual organic in the test film. Even though ~3CD was found tc.~ effect~:vely complex residual organics in the linear low density polyethylene (LLDPE) resin, it was incompatible with the resin and formed ,BCD particle agglomerations.
We have evaluated nine modified ~3cyclodextrins and a milled a-cyclodextrin (particle size 5 to 20 microns).
The different cyclodextr:in modifications were acetylated, octanyl succinate, ethoxyhexyl glycidyi ether, quaternary amine, tertiary amine, carboxymethyl, succinylated, amp:hoter:ic and trimethylsilyl. ether. Each experimental cycl~~dextrin (lo loading wt/wt) was mixed with low density ool.yethylene (LLDPE) using a Littleford mixer and then extruded using a twin screw Brabender extruder.
The nine modified cyclodextrin and milled cyclodextrin LLDPE profiles were examined under an optical microscope at 50X and 200X magnification. The microscopic examination was used to visually check for compatibility between LLDPE resin and cyclodextrin. Of the ten cyclodextrin candidates tested, three (acetylated, octanyl succinate and trimethylsilyl ether) were found visual:Ly to be compatible with the LLDPE
resin.
Complexed residual film volatiles were measured using cryotrapping procedure to test 50 ~iCD film sample and three extruded profiles containing to (wt/wt) acetylated ~iCD octanyl succinate ~iCD and trimethylsilyl ether. The method consists of three se~~ara.te steps; the first two are carded out simultaneously while the third, an instrumental technique for separating and WO 96/00260 ~ ~ ~ ~ ;~ ~. ~ PCT/US95105999 a ._; .., detecting volatile organic compounds, is conducteu aft__ ~~nP c,:'1;.: tW~:. ir: _.._ =i~-su See'", a:: _i. ~ r~= , v ne -t pu~ , a -T_ ga_:
iS 'uSeC t: C% S~:_r~~ '. _.l.c~~ llF?f:2"Otn t!'le sampi.~.. Du?~~_n t..rl~
gas stripping step, the sample is heated at ~~~~°~. The a samn~~~~~ is spiked wir~'m a surroaate ibenzene-d~ i immediately p~:io.r: t~~:: t.~F: analysis. Benzene-d, serves as an internal ~~" su~~rogate ;_~. ~_:orrect each set of test data fc=w re~':zre~~~,~. Tt,:e se:rold step concentrates the volatiles removed ~ ror~~ th~~ sample by freezing the oompcunds from the stripping gas in a headspace -~-ial rmme~..~Pd ...~~ a 1 vqui~'t r_it,_caei, s'rap. At the end ;._. the gas-stripping st.e~:, an :internal standard (toluene-d8) is injected direct~.y into the headspace vial and the T~~ial is capped immedvately. Method and system blanks are roterspersed wv~tn ~~amples and treated in the same manner as samples tmonitor contamination. The concentrated organic components are the: separated, identified and qua:ltitated by 'heated headspace high resolution gas chromatography%mass spectrometry (HRGC/MS). The results 2~ of the residual volatile analyses are presented in the table below:

o Volatile Complexation Sample Identification as Compared to Control 0 BCD Blown Film 8(:;~
I~ Acylatea BCD Profile 4~
1_% Octanyl 5uccmate (3CD Profile Ci 1a Trimethvisil~~1 etrner Profile 48 ~ e. ~~T~ ~il i..ed P~~nf 1.~.F>
I-o i v Ir_ these preliminary screening tests, ~3CD
derivatives were shown tc.~ effectively complex trace volatile organics inherent in low density polyethylene resin. used to make experimental film. I:; 5 0 BCD loaded 4n: LLDPE film, approximately 80°,-: of the organic ~ro..atiles were complexed. However, all ,BCD films (IA and 50) had an off-color (light brown: and off-odor. The color and 219858 .._ _.

odor problem is believed to be the result: of :irect decomposition of the CD or impurity in the C~. Two odor-active compounds (2-furaldehyde and 2-furanmethanol) were identified in the blown =ilm samples.
Of the three modified compatible CD candidates (acetylated, octanyl succinate and trimethylsilyl ether), the acetylated and trimethylsilyl ether CD were shown to effectively complex trace volatile organics ~0 inherent in the LLDPE resin. One percent loadings of acetylated and trimet:~ylsilyl ether s:TMSE.) ,3CD showed approximately 50~ of she residual LPDE organic -rolatiles were complexes, while the octanyl succinate ~D did not complex residual LLDPE resin ~roiaciles . '~~.=_ec 3CD was found to be 1 ess effective (28%) than the ace=ylated and TMSE modified ,QCD' s .
Plastic packaging materials all interact to some degree with the food product their protect. the main :node of interacts on of plastic p ackag;~!g of =tcd is :?0 through t:~e migration of organic mo~:.acules _-om tze environment thrcugh the polymer _'_'m vista th' head space c. t he package where they are abscrbed by t he L:.cd product. Migration or transfer c= organic :rc=~cules c=
t he package to the food, during st:,rage, is e=fectad y :~S environmental conditions such as temperatuY?, jterage time, and other environmenta,~ factors (e,.g., humidity, type of organic molecules and concentration thereof).
Migration can have both auality ~consume~~ r~~i~tancei and toxicological influence. The objective ~_ packaging :30 film testing is to measure how specific barr_ers may izf 1 uence the quality of packaged i~:di vi<iual foods . To simulated accelerated shelf-life testing fir lew-water-activity food products, the testing was ccnducted at a temperature of 72°F (22°C) and 105°E' 'a0.~°C) , and a 35 relative humidity of o0%. These temperature and humidity conditions are probably similar tc those found in uncontrol led warehouses , iy~y)~y~ ,r,~ s;c,~t~,r, and in storage .
~~I. s i 11r .. J ~ ~--WO 96100260 ~ ~ ~ ~ ~ ~ ~ PCT/US95I05999 3 ~'.' If a polymer is moisture sen:~:~.tive>,, t:~e relative humidity can affect the film's pe~:-~ormance especially in low-water-activity food products. Because a packaging film during actual end-use conditic:ns will be separating two moisture extremes, relative humidity in the permeation device was controlled on both sides of the film. The environment side, representing the outside of the package, was maintained at 60°. relative humidity, and the sample side, representing the inside of a package containing a low-water-activity product, at 0.25.
A combination of permeants was used to measure the functian and performance of the Cz. A combination was used to be realistic, since gasolina (principally an aromatic hydrc~carbon mixture) and printing ink solvents (principally an aliphatic hydrocarbon mixture) are not formed from a single compound but are a mixture of compounds.
The aromatic permeant contained ethanol (20 ppm), toluene (3 ppm), p-xylene (2 ppm), o-xylene (1 ppm), trimethyl-benzene (0.5 ppm) and naphthalene (0.5 ppm).
The aliphatic permeant, a commercial paint solvent blend containing approximately twenty (20) individual compounds, was 20 ppm.
The permeation test device Figure 3 consists of two glass permeation cells or flasks with cavities of 1200 ml (environment cell or feed side) and 300 ml (sample cell er permeating side).
Experimental film performance was measured in the closed-volume permeation device. High-resolution gas chromatograph (HRGC) operated with a flame ionization detector (FID) was used to measure the change in the cumulative penetrant concentration as a function of time. Sample-side (food product side) compound concentrations are calculated from each compound's response factor. Concentrations are reported in parts per million (ppm) on a volume/volurne basis. The 219~85~
. . ..
_ . :..

cumulative penetrant concentration on the sample-side of the film is plotted as a function of time..
We produced four experimental test l:ilms. Three of the films contained ,QCD at loading of i%, 3% and S%
S (wt/wt) while the fourth was a control film made from the same batch of resin and additives but without aCD.
A second experimental technique was also undertaken to determine whether (3CD sandwiched between two control films will complex organic vapors permeating the film.
._0 The experiment was carried out by lightly dusting ,l3CD
between two control film sheets.
The testing showed the control film performed better than ,3CD loaded films . 'i'he per-.neacion test results a_so demonstratad the higher 'he 3CD loading =he poorer the f=lm performed as a barrier. The test results for sandwiching ~iCD between two control films showed (3CD being twice as effective in reducing permeating vapors than the control samp__:s wit'.~_out 3CD.
'T'his experiment supporte~~ that CD does c:;mpl ex 2C permeating organi c vapors in the fii:n ;_ the ~-l m' s barrier qualities are not changed during the manufaCttlri_ng proCeSS mak=ng the tll m a -SSS eT_':eC :='T°_ barmier.
Tre 1 % TMSE ,3CD fil m was sl.ght~:r better than t he 25 =% acetylated ~3CD film (24% -vs- 26%? fo:: removing aromatic permeants at 72°F (22°C) adding more modif_ed CD appeared to have no improvement.
For aromatic permeants at X05°F ;40.5°C), both .%
TMSE ~iCD and 1% acetylated (3CD are approximately ~.3%
;30 more effective removing aromatic permeants than 72°F
(22°C). The 1% TMSE film was again slightly better than the 1% film (36 % -vs- 31%) for removi ng aromatic permeants.
The 1% TMSE film was more effective initially 3S removing aliphatic permeants than the 1~ acetylaced BCD
film at 72°F (22°C) . But for the duration of the test, ?% TMSE ~iCD was worse than the control while 1%
T
~,~~~~.'_:Vi:~... . __.

~'i9235~

acetylated aCD removed only 5% of the aliphatic r~ermeants.
We produced two experimental aqueous coating solutions. One solution contained hydro~:yethyl ,QCD (35%
by weight) and the other solution contained hydroxypropyl aCD (35 by weight). Both solutions contained 10% of an acrylic emulsion comprising a dispersion of polyacrylic acid having a molecular weight of about 150,000 (Polysciences, T_nc.; (15% solids by :LO weight) as a film forming adhesive. These solutions were used to hand-coat test _ilm samples by laminating two ~LDPE films together. TwC Cllff~rent coating techniaues were used. The first technirnae very slightly stretched t~NO _ilm samples flat, the c.~,ati_~.c was then :L5 applied using a hand roller, and _:~.e:~ t:~~e films were laminated together while stretched zlat. The ~.ev. 1 samples were not stretched during the lamination process. A11 coated samples were finally placed in a vacuum laminating ~r~ss to removes air bubbles between '~0 the f i lm sheets . Film coating th i.c:c:~esses were approximately 0.0005 ;nches i~7.0'~3 mm). These CD coated _i 1 ms ar_d hydroxylmethy'i cel 1 ulose coated cor_rrol fi.'_~:~s were subsequently tested.
r=ducticn in aromatic and al=phatic vapors by the '?5 hydroxyethyl ,~C~ coating is greater .n the first several hours of exposure to the vapor and then dimir_ishes over the next 20 hours of testing. Higher removal of aliphatic vapors thar_ aromatic vapors was achieved by the hydroxyethyl ,QCD coating; this is believed to be a :30 function of the difference in their molecular size (i.e., aliphatic compounds are smaller than aromatic compounds). Aliphatic permeants were reduced by 46% as compared to the control over the 20 hour test period.
Reduction of aromatic vapors was 29% as compared to the 35 control over the 1~ hour test period.
The Rev. 1 coated hydroxyethyl ,l3CD reduced the aliphatic permeants by 87% as compared to the control 1 ~,1~~!
rr~SW . -Hsv;.,~..:~~ .., -~~g~~~~ _ over the 20 hour test period. It is not known if the method of coating the film was responsible for the additional 41% reduction over the other hydroxyethyl ~3CD
coated film.
The hydroxyethyl ,BCD coating was slightly better for removing aromatic permeants than the hydroxypropyl ,BCD coating (29% -vs- 20%) at 72°F (22°C) .
LARGE SCALE FILM E~PERI~IENTAL
..0 Preparation of Cyclodextrin Derivatives Examt~le I
An acetylated Q-c-rclodextrin was obtained that contained 3.4 acetvl ;:routs per cvcaodext:rin on the _:., primary _:~,~ group .
Example II
Tri methyl Sil y 1 =t:~:er of ,3-cyclodext:r in Into a rotary ~Val~OraLOy eQL:i piled 'N J_ ~i1 a a ~ C v -,nil~__liter round bottom f ~ ask a nd a nip=ogen acmcsprer=, 2C introduced at a rate of ~'~~ ',ttlll=.~.~tarS N_ pe'r' ml.nt:t~, waS plaC°d t-'free 1 hers ::'f dimethyl=:rrmamlde. _:~t~ _ .e di:nethvlfor:nami de was ~.laced 750 crams oj3-cvciodexLrin. The ,(3-c~rcl odexLr ~ n was =orated and d=ssolve~ =~? dimethvl=crmam=de at 50°C'. After <?5 dissolution, the flask was removed =rcm the rotary waporater and the contents were cooled to approxima~~ly 18°C. Ir_to the flask, placed on a magnetic s~irrer and eauipped with a stir bar, eras added 295 rnilliliters of hexamethyldisilylazine (I~'MDS- Pierce Chernica 1 No .
.30 84769) , toll owed by the careful add:i :ion of 97 milliliters of trimethvlchlorosilane (TMCS - Pierce Chemical Vo. 88531.). The careful addition was achieved by a careful dropwise addition oz an in=r_ial charge of 20 milliliters and af~er reaction subsides the careful .?5 dropwise addition of a subseauent 20 milliliter portions, etc. until addition is complete. After the addition of the TMCS was complete, and after =eact=on . . _ 2192858 ,.._ v subsides, the flask and its contents were placed on the rotary evaporator, heated to 60°C wh~.la maintaining an inert nitrogen atmosphere flow of 100 milliliters of N, per minute through the rotary evaporator. The reaction S was continued for four hours followed by removal of solvent, leaving 308 grams of dry material. The material was removed from the flask by filtering, washing the filtrate with deionized water to remove the silylation products, vacuum oven drying (7S°C at 0.3 :10 inches of Hg [lOkPa]) and stored as a powdered material and maintained for subsequent compounding with a thermoplastic material. Subseauent spectrographic inspection of the material showed the 3-cyclodextr=n to contain approximately i . ~ tr imethyls=1 YJ;=acher substituent per ,3-cyclcdextrin molecule . T'~e substitut=cn appeared to ce commonl~r cn <~ primar-_r 5-carbon atom.
Example III
30 ~n i:ydroxypropyi ,3-cyclodextrin was obtaiT:ed wi th 1.S hydrcxypropyl groups per molecule on the pr_mar;r o-vH~ grCUp OL t:''_e ,3C~' .
Exaiap 1 a Iy ~n hydroxyethyl ;3-cyclodextr in was obtair_ec with 35 1.S hydroxyethyl groups per molecule cr_ tre pr_mary ~-OH
group of the ,(3CD .
Preoa~ation of Films We prepared a series of films us'_ng a linear lcw density polyethylene resin, ~3CD and derivatized 3CD such as the acetylated or the trimethylsilyl derivative of a cyclodextrin. The polymer particles were dry blended with the powdered ,Q-cyclodextrin and ,3-cycledextrin derivative material, a fluoropolymer lubricant i=''1? and the antioxidant until uniform in the dry blend. The dry blena material was mixed and extruded in a pellet form in a Haa~ce Svstem 90, 3/4" cor.;ical extruder. The resalting pellets were collected for film preparation.
- . ., . :...
f':::. . i ~.: ~, J
1 ' s:l'..-2 i 9288 ..: ._ .
Table IA displays typical pelletizing extruder conditions. The films were blown in the apparatus of F=gure 2. Figure 2 shows extruded they-moplastic tube 21 exiting the die 22. The tube is collapsed by die 23 and S layered by rollers 24 into the film 25. The extruded tube 21 is inflated using air under pressure blown through air inlet tube 26. The thermoplastic is melted in the extruder. The extruder temperature is taken at the mixing zone 27. The melt temperature is taken in the melt zone 28 while the die temperature is taken in the die 29. The extrudate is cooled using an ai= blown cooling stream from t~ze cooling ring 2C. The general schematic background oz Figure 2 is represer_tative or the Kiefel b'~own fi_m extruder, ~0 mm dig diameter, used in the actual _.. preparation of ~~he blown film. ~_'he _,_i:n is mar_ufacoured according to the above protocol and ~epo~:ted =n Tab_e =3.
T'_ne film was tested for ~.;ansmission =atE:s at ~ variety oz environmental conditions. Environmental test condi~icr_s are shown below in Table ~:.
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a a c WO 96100260 a ~ ~ ~ PCTIUS95105999 1 Cj The results: of the testing snow that the inclusion of a compatible cyclodextrin materia~ in the thermoplastic films of the invention substantia~ly improves the ba~~rier properties by redwing transmission rate of a variety of permeants. The data showing the improvement in transmission rate i.s shown below i.n the following data tables.

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We prepared a series of aqueous coatings containing hydroxvpropyl ~3CD. One of the coatings vvas prepared from a l0% acrylic emulsion (a polyacryl~_c acid polymer having a molecular weight of about X50,000 purchased S from Polysciences, Inc.). The 10's acryl~_c emulsion contained hydroxypropyl ,(iCD at a S% and 7_Os by weight loading. These solutions were used to hand-coat test film samples by laminating twa films. The coatings were applied to linear low density polyethylene =film sheet :LO containing 0.5% acetylated ~3CD (Rol°~. No. 7) and to a second film sheet containing 2% acetylat::d 3CD (Roll No.
8) using a hand roller and then laminac_==c =:ne films.
The 'films were not stretched during wam=:~ac_cn. All coated samples were pl aced i n a -.racuum _a~m_-.at=ng press :.5 to remove air bubbl es between the f:=~.;~ s~~ee_s . The acryl is coat ing thickness was about ~~ . ~ 0 C) 2 --.c h (O.OOSmm) . An acrylic coated contrc:~ was ~r=Dared ir_ an i denti cal manner containing -~o hydrox:~r~:c~rl 3CD. T'~e multilayer structure was tested with ~e ~.5'-, acetylated 20 ,3CD rilm zacing the environmental L:! ask s=de of t:~e _~st cell (Fig. 3).
A second coating was prapared ~_cm _x -r_~_yiidene chloride latex PVDC, 60 wt-~ solidsi :,urc=aced rrom Dagax Laboratories, Inc. The PVDC latex coming was 2 S prspared wi th two l eve l s o z hydroxypr;,pv l ;CD - i 0 % and 204 by weight of the derivatized cyclcdeatrin. These solutions were used to hand-coat linear lcw density polyethylene test film samples by lam=nat_ ng the two films together. The coatings were apolie d to two :30 control film sheets (rolled into one) using a hand roller and laminated together. The Films were not stretched during lamination process. ~':i coated samples were placed in a vacuum laminating press to remove air bubbles between the film sheets. The P~i::,C coating 35 thickness was approximately 0.0004 i.ch ;~.~;mm).
PVDC coated control was prepared ir_ an i~dent~_cal manner but without hydroxypropyl ~3CD.
r "~ ~~ ~-r i..,~~~,-~~r;_. vi~.L~_ I

WO 96100260 ~ , _ PCTlUS95/05999 2~i 92~3y The data fo-wlowing the preparatory examples showina_ improvement in transmission rate was obtained using the following genera~_ test method.
P~Iethod Summary This method involves experimental techniques designed to measure the permeability of selected organic molecules through food packaging _ilms,. using a static concentration gradient. The test methodology simulates accelerated shelf-life testing COIldltions :by implementing various storage humid.itie:~, product water activities and temperature conditions and using organic molecule concentrations found in previously tested food products to simulate outside-the-package organic vapors in the permeation test cel:i. Thi:~ procedure allows for the determination of the following compounds: ethanol, toluene, p-xylene, o-xylene, 1,2,4:-trimethyl benzene, naphthalene, naphtha solvent blend, etc.
Environmental Threshold Odor Conc. Cell Conc.
Test Compounds ul/L ppm ul/L ppm Ethanol 5 - 5000 20 Toluene 0.10- 20 3 p-Xylene 0.5 2 o-Xylene 0.03_ 12 1 1,2,3-Trimethyl Benzene NA 0.5 Naphthalene 0.001- 0.03 0.5 Naphtha Solvent Blend NA 40 Table 1. Permeant Test Compounds In a typical permeation experiment, three steps are involved. They are (a.'. the instrument sensitivity calibration, (b) Film testing to measure transmission and diffusion rates, and (c) the quality control of the permeation experiment.
Film samples are tested in a closed-volume permeation device. High-resolution gas chromatograph (HRGC) operated with a flame ionization detector (FID) j~ ~ ~ PCTJUS95/05999 uSeQ tC L'lea:~ii~~=' '.::?e C~:ianQe' '~rl the Clim',.llcitlve penetrant- r~c~i ;.. ,..~.i;~r. =~:; « fund, ~._ cf time.
amn~.e ;:i< .~.,:i eri~~ .-_;;nmenr_-s ide test ~,"mncun concentrate.~,~~s are, ,-alcaa. ~" ~ror,, ea .,.: :~ompour.;i~ c response fact.~~: __ _ L~~-a',~icn curve. ConcentrG~ious are then vc.':ume_c~r~-e;cte;? f~~;--. each specific set ..
permeation cells r permean~ mass is desired.
The cumulativ~° penetrant concentration is plotted as a function ~_. tYirr;e cr. both the upstream (environmer_t,~
1=~ and downstream ;sample] side of the film. The diffusior_ rate and transmission rate o~_ the permeant are calcvulated from the permeation curve data.
1 . ~ Equipment and Reagents Egvaipmer.~_ 1J ~Oas chromat~:7c~raph (HP 5880) equipped with flame ion;~zation detect~:::r, a six-port heated sampling valve wit;u ~ ml sampling loop and data integrator JAW capi.llarTa~ c:~olumn. D1~-_~, 30M X 0.250mm ~D, 1.0 umdf ..
20 Olass permeation test cells cr flasks. Two glass flasks with catJiti.es of approximately 1200 ml ~;envircnmer:t ~el~. ~~~ ~:eed side; and 300 ml (sample flask or permeating sidel (Fig. 3;.
Permeation; cel.:" clamping rings (2j .
Permeation cel_aluminum sea,~~ rings (2).
Natura~~~. Rubber Septa. 8 mm OD standard-wall or _ mm OD ( =:, l dr ich Chemic:a ~ Company, Milwaukee , WI ) .
Assorted ~.aborato2:y glass ware and syringes.
Assorted :~aboratory supplies.
~C 2 Reagents Reagent water-.. Water in which interferences are not observed a~: t.ie MDZ~ ~;f the chemical analytes of interest.. A water puri.fi_cat:ion system is used to generate reagent ware}:- we,,ich: has been boiled to 80 3~ volume, capped, and allowed to cool to room temperature before use.
Stock Ethanol,'Aromati.w Standard solution:. Ethanol WO 96100260 2 ~ ~ ~ ~ J ~ PCT/LTS95/05999 (0.6030 gram), toluene (0.1722 gram), p-xylene (0.1327 gram), o-xylene 10.0665 gram), trirriethylbenzene (0.0375 gram) and naphthalene (0.000 grams package in 1 m sealed glass ampules. Naphtha blends ~~tandard is a 5 commercial paint solvent blend containing approximately twenty (20) individual. aliphatic hydrocarbon compounds obtained from Sunnyside Corporatic:~r., Consumer Products Division, Wheeling, IL.
Triton X--100. Nonylphenol nonionic surface active 1C agent (Rohm and Hass).
2.0 Standards Preparation 2.2 Permeation Working Standard A stock permeant test standard solution is used.
These standards are prepared by we.~.ght from neat certified reference compounds, actual weight and weight percent are shown.
The working ethanol/aromatic standard is prepared by injecting 250 ul of the stock standard solution into 100 ml of reagent water containing 0.1 gram of surfactant (Triton X-100). It is important that the Triton X-100 is completely dissolved in the reagent water prior to adding the permeant stock standard. This will insure dispersing the test compounds i.n the water.
In addition, the working standard should be mixed thoroughly each time an aliquot is dispensed. It is advisable to transfer the working standard to crimp-top vials with no headspace to minimize losses due to the large headspace in the volumetric flask used to prepare the standard.
A working naphtha blend standard i:~ prepared by injecting 800 ~L of thE~ "neat" naphtha :solvent blend into 100 milliliters of reagent water containing 0.2 gram of surfactant. (Tri.ton X-100) .
An opened stock standard solution ;should be transferred from the glass snap-cap vial to a crimp-top vial for short-term storage. The vials may be stored in an explosion-proof refrigerator or freezer.

WO 96/00260 ~ ~ j~ ~ ~ ~;o ~~ PCTIUS95105999 Calibration Standards 'a, ibra tion :. :_anciar ds ar_ a prepared a t a mir.i,-r.um three concentratzor_ vels b~~ addina volumes ~f the workin:~ standard t _, :r volumetri_ flask and di i~.rti.r:c we _ volume with reagenv water. C_)ne cf the standards ~_s prepared at a concentration near, but above, the method detection ~imit. '~~he ether concentrations correspond the expected ranr~~,.. ~ concentrations found i: the environment and samn~~e side cells.
_5.0 Sample Preparation m Sam~~'~~L Preparation The environment flask Figure 3 and sample flask are washed before use in soapy water, thoroughly rinsed with deio:.ized water, and oven--dried. Foliowin g cleaning, 1= each flask -is fitt:e~d with a rubber septum.
'he f i_~m tes.. ~;pecimen .s cut to the inside diameter of the aluminum seal. ring using a template.
The film test specimen diameter is important to prevent diffusion losses along the cut. edge circumference. The 20 film sample, aluminum seals, and flasks are assembled as shown in Figure 3, but the clamping ring nuts are not tightened.
The test cel-w ;Fig. 3i is prepared. First the sample flask 32 and environment flask 31 are flushed 2~ with dry compressed air to remove humidity in the sample and environment flasks. This is done by puncturing the sample system 33 and environment septum 34 with -~ needle and tubing assembly which permits a controlled flow of dry ai~~ through both flask~7 simultaneously. The clamp 30 rungs 35 are loosely fitted to the flasks to eliminate pressure buildup c-~r, eit:~er side. of the film 30. After flushing both flasks for approximately 10 minutes, the needles are removed arid the clamp rings tightened, sealing the film 30 between the two flasks. Rubber 3h faced alumir_urr~ spacers 36a, 36b are used to ensure a gas tight fit.
The sample side is infected with 2 uL of water per 2192358 - ....... ..
;.. . . ..
;:

300 ml flask volume. Since the sample flasks vary in volume, the water is varied to correspond. to the volume variations. The 2 ~,L of water in the 300 ml flask volume is comparable to a 0.25 water activity product at S 72°F (22°C). Next, 40 uL, the permeation.
ethanol/aromatic working standard or 40 ~.L of the naphtha blend working standard prepared according to section 2.2, is injected into the environmental flask.
Either of these working standards will produce a 600 1.0 relative humidity at 72°F with a permeant concentration (parts per million-volume/voiume) in the X200 ml volume fl ask indicated in 'table :.. Other humid=.ties or permeant concentrations may be employed ..n the test method by using psychrometric chart _., de:tarmine ..S humidity and using the gas loss to ca_cu~..at2 permeant concentration. The time is recorded and the permeation cell placed into a thermostatically cont_~olled oven.
Samples may be staggered to accommodate GC run time.
Three identical permeation devices are pr?pared.
20 Triplicate analyses are used for ~~C purpc>ses.
At the end of each t'_me ynterva~_, a sample Lrcm the group 1S r2mOVed frCm the Oven. ~T'hp Sn'T=.rCnment3l =_ Sk 1S anaiyZed f~rSt, using a heated S'-~-pCT.'t Sampllng va_ve fitted with a I ml loop. "'he _cco is _'_ushed with a:5 a _ ml volume of the environmer_t-s=de or sampl=_-side air. The loop is injected onto the capi'.lary column.
The GC/FID system is started manually =o~.lowing the injection. Up to eight 1 ml sample ~:~ections may be taken from the sample and 'nvironment side of a singl=
30 permeation experiment.
Sample side and environment s_de test compound concentrations are calculated from each <.:ompound's calibration curve or response factor 'a~:ation i or 3).
Concentrations are then volume-corrected for each 3S specific set of permeation flasks if permeant mass is desired.
a.0 Sample Analysis -.. c,:c v-i';i':i~1(-.:L~~ . -

6(1 PCT/US95105999 2I ~2~ J

4.1 Instrument Parameters Standards and samples are analyzed by gas chromatographvy u~>inc~ the followin~~ method parameters:
Column: J&Gd column, DB-5, 30 M, 0.25 mm ID, ~ umdf Carrier : H~rdrogen Split Vent: 9.4 ml/min Injection Port Temp: 105°C
Flame Detector Temp: 200°C
Oven Temp l: 75°C
Program Rata 1: 15°C
Oven Temp 2: 125°C
Rate 2: 20°C
Final Oven Temp: 200°C
Final Hold ~''ime : 2 Min The six-port sampling valve temperature is set to 105°C.
4.2 Calibration A three point calibration is prepared using standards in the range of the following test compounds:
Calibration Curve Range Test Compounds ppm (~L) Ethanol 2 - 20 Toluene 0. 3 - 3 p-Xylene 0. 2 - 2 o-Xylene 0. 1 - 1 1,2,4-Trimethyl Benzene 0.05 -- 0.5 Naphthalene 0.05 - 0.5 Naphtha Solvent Blend 4.0 - 40 To prepare a calibration standard, add an appropriate volume of the working standard solution to an aliquot of reagent water in a volumetric flask.
4.2.1 Secondary Dilutions of Working Standard for Calibration Curve 5 to 1 dilution: Place 5 ml of working standard into a 25-ml volumetric flask, stopper, then mix by inverting flask.
2.5 to 1 dilution: Place 10 ml of working standard .... 1. .r 219 ~ a8 -_ ~.r . .: a.r . ,.
into a 25-ml volumetric flask, stopper, then mix by inverting flask.
Analyze each calibration standardland tabulate compound peak area response versus the concentration of S the test compound in the environment side. cell. The results are used to prepare a calibration curve for each compound. The naphtha solvent blend is a commercial paint solvent containing approximately twenty (20) individual aliphatic hydrocarbon compounds. The :LO response versus concentration is der_ey-mined by totaling the area under each of the twenty individual peaks.
Method of least sauares is used to ~=t a straight line to the calibration curve. The slope of each test compound's calibration curve ~~s then oaiculated for :.5 determining the unknown concentrat_c;n. 'the average =esponse factor may be used in place of t=he cal_brat_on curve.
The working calibration curve or response factor must be verified on each working day by measurement of 20 one or more calibration standards. ;f the response of any compound varies more than 20a, the fast must be repeated using a f=esh calibration standard. __ _.e results still do nct agree, generate a .new cal~Dra~t_on curve.
:?5 ~ . 3 Analysis oz Cal ibration Curve and Metzod Detection Level Samples Recommended chromatographic conditions are summarized above.
Calibrate the system daily as described above.
30 Check and adjust split vent rate and check rate with soap film flow meter.
To generate accurate data, samples, calibration standards and method detection level samples must be analyzed under identi~al conditions.
:35 Calibration standards and method detection samples are prepared in the environment flask only. This is accomplished by using a 1/2 inch ( x.27 cm) plastic disk a r' J,-"~ ~~
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and aluminum sheet disk the diameter of the environment flange in place of vhe sample flask. A single sewing ring is placed onto the environmental glass flange followed by an aluminum sheet, and then the plastic S disk.
The environment flask is flushed with dry compressed air to remove humidity in the sample and environment flask. This is done by puncturing the environment septa with a needle and tubing assembly ?.0 which permits a controlled flow of dry air through the flask. The clamp rings are loosely fitted to the =task to eliminate pressure buildup. After flushing both flasks for approximately 10 minutes, the needle is removed and the clamp rings ~ightened, sealing ~:le ..S aluminum sheet against the seal ring.
Next, 40 ~.l of the oermeaticn ethanol/aromatic working standard or secondary diluticns of the working standard is injscted into the environment. ylask.
~llternativel y, s0 ~:L of the r_aphtha solve:r_t b 1 erd or secondary dilutions or the wor'.ting standard is injected into the environmental flask. The tome i.s recorded and the LlaSk 1S pl aCed into a ~:'lerLlOStaG=Cal.iy C:7nt=.~.=_~r',1' oven.
~t ti:e end OL ~~ mlnuteS, =.~_e vI':TT'~rc;r_me.~.t =! ~j:~C 1S
25 removed from the oven. The environmental. flask is analyzed using a heated six-port sampling valve fitted with a 1 ml loop. The loop is flushed with a 1 ml volume of the environment-side or samz~le-side air. The loop is injected onto the capillary column. The GC/FID
70 system is started manually following the ir_jection.
4.4 Calculation of Results 4 4.1 Test Compound Res,~onse Factor Sample-side and environment-side test compound ccncer_trations are calculated for each compound's a5 calibration curve slope or response 'actor !RF).
Concentrations are then volume-corrected for each specific set of permeation cells if permeant mass is _. i WO 96!00260 ~ ~ ~ ~ ~ J ~~ PCZ'/[7g95/05999 desired.
Concentration of Compound ir; ppm _ _ Pf=ak Area Calik~ration Curve Slope S Compound Specific RF . Concentrat=ion c;'__ ~'ompound in ppm Peak Area y Concentration o~ Compcsund in ppm = Pe«k Area X RF ,, The cumulative penetrant mass is :plot.ted as a function of time on both the upstream (environment) and downstream (sample) side of the film. The diffusion rate and transmission rate of the permeant area calculated from t-he transrr~ission ~~urve data .
4.4.2 Transmission Rate When a permeant does not interact with the polymer, the permeability coefficient, R, :is usually characteristic for the permeant-polymer system. This i~
the case with thE: permeation of many gases, such as hydrogen, nitrogen, oxygen, and carbon dioxide, through many polymers. If a permeant interact:> with polymer molecules, as is the case with the permeant test compounds used in this method, P ~.s no longer constant and may depend on the pressure, film thickness, and other conditions. In such cases, a single value of P
does not represent the characteristic permeability of the polymer membrane and it is necessary to know the dependency of P on all possible variables in order to obtain the complete profile of the permeability of the polymer. In these cases, the transmission rate, Q, is often used for practical purposes, when the saturated vapor pressure of the permeant at a specified temperature is applied across the film. Permeability of films to water and organic compounds is often expressed this way.
P = (Amount of Permeant)(Film Thickness) (~;
(Area)(Time)(Pressure-drop Across the Film) 4 ~ Q = Amount of Permeant)(Film Thickness) (5) (Area)(Time) In this application, Q is represent=ed in units of am-0.001 inches 10.025 mm) X00 in= (0 . 0645m~ ) -day.
One of the major variables in determining the permeation coefficient is the pressure drop across the film. Since the transmission rate Q includes neither pressure nor concentration of the permeant in its dimensions, it is necessary to know either vapor pressure or the concentration of permeant: under the :LO conditions of the measurement in order to correlate Q to The pressure-drop across the film f_-om environment side to sample side is principally due to water vapor pressure. The water concentration or .ZUmiditv does not =emain constant and is not measured during the time intervals the organic compounds are ~ralyzed, and therefor? the pressure across the membrane is not determined.
The above examples of thermoplastic =iims <? 0 containing a variety of compatible cyclociext r i n derivatives shows that the invention can 'ce embodied variety of differerr thermoplastic rilms. ~ rt r ~u he~., a -rariety of different compatible derivat_=:ed cvciodextrin materials can be used in tye invention. vastly, the a?5 films can be manufactured usir_g a var~_et;r of film manufacturing techniques including ex~ru:~ion ar_d aaueous dispersion coating to produce useful barriers.
The above specification, examples c: substituted cyclodextrin, extruded thermoplastic films and test data .30 provide a basis for understanding the technical aspects o .L

~~~J~

the invention. ~ince the invention can be made with a variety of embods.ment~ , the inven~_ic;n resides in the claims hereinaftt:r appended.

Claims (106)

WE CLAIM:

1. A thermoplastic film composition, having improved barrier properties, the film composition comprising:
(a) a thermoplastic polymer web; and (b) uniformly dispersed in the web, an effective permeant absorbing amount of a polymer compatible cyclodextrin derivative;
wherein the cyclodextrin is substantially free of an inclusion complex compound.

2. The film of claim 1 wherein the thermoplastic polymer comprises a vinyl polymer comprising an alpha-olefin.

3. The film of claim 1 wherein the thermoplastic polymer comprises a chlorine containing vinyl polymer comprising vinyl chloride or vinylidene dichloride.

4. The film of claim 3 wherein the thermoplastic polymer comprises a poly(vinyl chloride-co-vinyl acetate) or a poly(vinyl chloride-co-vinylidene dichloride).

5. A film of claim 2 wherein the thermoplastic polymer comprises a polyvinylalcohol, a poly(ethylene-co-vinyl alcohol), a poly(ethylene-co-acrylic acid) or a poly(ethylene-co-methyl acrylate).

6. The film of claim 1 wherein the cyclodextrin derivative comprises a .beta.-cyclodextrin derivative.

7. The film of claim 6 wherein the cyclodextrin derivative contains at least one substituent on a cyclodextrin primary carbon atom.

8. The film of claim 1 wherein the cyclodextrin comprises .alpha.-cyclodextrin, .beta.-cyclodextrin,- .gamma.-cyclodextrin or mixtures thereof.

9. The film of claim 1 wherein the thermoplastic web contains about 0.1 to 5 wt-% of the polymer compatible cyclodextrin derivative.

10. A packaged food, comprising at least one food item and a package substantially, surrounding the item, the package comprising a thermoplastic film composition, having improved barrier properties, the film composition comprising:
(a) a thermoplastic polymer web; and (b) uniformly dispersed in the web, an effective permeant absorbing amount of a polymer compatible cyclodextrin derivative;
wherein the cyclodextrin is substantially free of an inclusion complex compound.

11. The food of claim 10 wherein the thermoplastic polymer comprises a vinyl polymer comprising an alpha-olefin.

12. The food of claim 10 wherein the thermoplastic polymer comprises a chlorine containing vinyl polymer comprising vinyl chloride or vinylidene dichloride.

13. The food of claim 12 wherein the thermoplastic polymer comprises a poly(vinyl chloride-co-vinyl acetate) or a poly(vinyl chloride-co-vinylidene dichloride).

14. The food of claim 11 wherein the thermoplastic polymer comprises a polyvinylalcohol, poly(ethylene-co-vinyl alcohol), a poly(ethylene-co-methyl acrylate).

15. The food of claim 10 wherein the cyclodextrin derivative comprises a ~i-cyclodextrin derivative.

16. The food of claim 10 wherein the cyclodextrin-derivative-contains at least one substituent on a cyclodextrin primary carbon atom.

17. The food of claim 10 wherein the cyclodextrin comprises ~-cyclodextrin, ~i-cyclodextrin, ~-cyclodextrin or mixtures thereof.

18. The food of claim 10 wherein the thermoplastic web contains about 0.1 to 5 wt-% of the polymer compatible cyclodextrin derivative.

19.- A method to prevent moisture vapor transmission to an item which method comprises separating the item from a source of moisture by imposing a thermoplastic film barrier between the source of moisture and the item, the film barrier comprising:
(a) a thermoplastic polymer web; and (b) uniformly dispersed in the web, an effective-permeant absorbing amount of a polymer compatible derivative cyclodextrin;
wherein the cyclodextrin is free of an inclusion complex compound.

20. The method of claim 19 wherein the thermoplastic polymer comprises a vinyl polymer comprising an alpha-olefin.

21. The method of claim 19 wherein the thermoplastic polymer comprises a chlorine containing vinyl polymer comprising vinyl chloride or vinylidene dichloride.

22. The method of claim 21 wherein the thermoplastic polymer comprises a poly(vinyl chloride-co-vinyl acetate) or a poly(vinyl chloride-co-vinylidene dichloride).

23. The method of claim 20 wherein the thermoplastic polymer comprises a polyvinylalcohol, poly(ethylene-co-vinyl alcohol), a polyethylene-co-methyl acrylate).

24. The method of claim 19 wherein the cyclodextrin derivative comprises a ~-cyclodextrin derivative.

25. The method of claim 19 wherein the cyclodextrin derivative contains at least one substituent on a cyclodextrin primary carbon atom.

26. The method of claim 19 wherein the cyclodextrin comprises ~-cyclodextrin, ~-cyclodextrin, ~-cyclodextrin or mixtures thereof.

27. The method of claim 19 wherein the thermoplastic web contains about 0.1 to 5 wt-% of the polymer compatible cyclodextrin derivative.

2B. A method to prevent contamination of a food item by a hydrocarbon vapor which method comprises separating the food item from a source of the hydrocarbon by imposing a thermoplastic film barrier between the source of hydrocarbon and the food item, the film barrier comprising:
(a) a thermoplastic polymer web; and (b) uniformly dispersed in the web, an effective permeant absorbing amount of a polymer compatible cyclodextrin derivative;
wherein the cyclodextrin is free of an inclusion complex compound.

29. The method of claim 28 wherein the thermoplastic polymer comprises a vinyl-polymer comprising an alpha-olefin.

30. The method of claim 28 wherein the thermoplastic polymer comprises a chlorine containing vinyl polymer comprising vinyl chloride or vinylidene dichloride.

31. The method of claim 30 wherein the thermoplastic polymer comprises a poly(vinyl chloride-co-vinyl acetate)or a poly(vinyl chloride-co-vinylidene dichloride).

32. The method of claim 29 wherein the thermoplastic polymer comprises a polyvinylalcohol, poly(ethylene-co-vinyl alcohol) or a polyethylene-co-methyl acrylate).

33. The method of claim 28 wherein the cyclodextrin derivative comprises a ~-cyclodextrin derivative.

34. The method of claim 28 wherein the cyclodextrin derivative contains at least one substituent on a cyclodextrin primary carbon atom.

35. The method of claim 28 wherein the cyclodextrin comprises ~-cyclodextrin,- ~-cyclodextrin, ~-cyclodextrin or mixtures thereof.

36. The method of claim 28 wherein the thermoplastic web contains about 0.1 to 5 wt-% of the polymer compatible cyclodextrin derivative.

37. A thermoplastic film composition, having improved barrier properties, the film composition comprising:
(a) a thermoplastic polyethylene having a melt index of 0.1 to 4 and a molecular weight greater than 200,000; and (b) uniformly dispersed in the web, an about 0.1 to 5 wt-% of a permeant absorbing amount of a polymer compatible cyclodextrin derivative;
wherein the cyclodextrin is free of an inclusion complex compound.

38. The composition of claim 37 wherein the thermoplastic polyethylene comprises a linear polyethylene.

39. The composition of claim 38 wherein the thermoplastic polyethylene comprises a linear low density polyethylene.

40. The composition of claim 37 wherein the polyethylene has a melt index of about 0.2 to 3.

41. The composition of claim 37 wherein the cyclodextrin derivative comprises an acetyl derivative of the cyclodextrin.

42. The composition of claim 37 wherein the cyclodextrin derivative comprises a trimethylsilyl derivative of the cyclodextrin.

43. The composition of claim 37 wherein the cyclodextrin comprises a ~-cyclodextrin.

44. The composition of claim 37 wherein the cyclodextrin derivative is formed on at least one primary carbon bf the cyclodextrin.

45. The composition of claim 37 wherein the cyclodextrin comprises an ~-cyclodextrin, a ~-cyclodextrin, a ~-cyclodextrin or mixtures thereof.

46. The composition of claim 37 wherein the cyclodextrin is present at a concentration of about 0.1 to 2 wt-%.

47. The composition of claim 37 wherein the thermoplastic polyethylene comprises a web.

48. A thermoplastic film composition, having improved barrier properties, the film composition comprising:
(a) a thermoplastic polymer comprising a chlorine containing vinyl polymer; and (b) uniformly dispersed in the web, permeant absorbing amount of a polymer compatible cyclodextrin derivative;
wherein the cyclodextrin is free of an inclusion complex compound.

49.The film composition of claim 48 wherein the thermoplastic web comprises a polyvinyl chloride homopolymer.

50. The film composition of claim 48 wherein the thermoplastic web comprises a polyvinylidene dichloride homopolymer.

51. Tha film composition of claim 48 wherein the thermoplastic web comprises a poly(vinyl chloride-co-vinylidene dichloride) polymer.

52. The film composition of claim 48 wherein the thermoplastic web comprises a poly(vinyl chloride-co-vinyl acetate).

53. The film composition of claim 48 wherein the cyclodextrin derivative comprises an acetylated cyclodextrin.

54. The film composition of claim 48 wherein the cyclodextrin derivative comprises a trimethylsilyl derivative of cyclodextrin.

55. The film composition of claim 48 wherein the cyclodextrin comprises an ~-cyclodextrin, a ~-cyclodextrin, a ~-cyclodextrin or mixtures thereof.

56. The composition of claim 48 wherein the cyclodextrin derivative is present in the thermoplastic web at a concentration of about 0.5 to.2 wt-%.

57. A method to prevent contamination of a food item by a fragrance, which method comprises separating the food item from a source of the fragrance by imposing a thermoplastic film barrier between the food item and the source of fragrance, the film barrier comprising:
(a) a thermoplastic polymer web; and (b) a uniformly dispersed in the web, an effective fragrance permeant absorbing amount of a polymer compatible cyclodextrin derivative;
wherein the cyclodextrin is free of an inclusion complex compound.

58. The method of claim 57 wherein the thermoplastic polymer comprises a vinyl polymer comprising an alpha-olefin.

59. The method of claim 57 wherein the thermoplastic polymer comprises a chlorine containing vinyl polymer comprising vinyl chloride or vinylidene dichloride.

60. The method of claim 59 wherein the thermoplastic polymer comprises a poly(vinyl chloride-co-vinyl acetate) or a poly(vinyl chloride-co-vinylidene dichloride).

61. The method of claim 58 wherein the thermoplastic polymer comprises a polyvinylalcohol, poly(ethylene-co-vinyl alcohol), a poly(ethylene-co-methyl acrylate).

62. The method of claim 57 wherein-the cyclodextrin comprises a ~-cyclodextrin.

63. The method of claim 57 wherein the cyclodextrin contains at least one-substituent on a cyclodextrin primary carbon atom.

64. The method of claim 57 wherein the cyclodextrin comprises ~-cyclodextrin, ~-cyclodextrin, ~-cyclodextrin, or mixtures thereof.

65. The method of claim 57 wherein the thermoplastic web contains about 0.1 to about 5 wt-% of the polymer compatible cyclodextrin derivative.

66. A method for preventing release of a pest attracting aroma from a food item comprising a meat product or a food product containing a cocoa derivative which method comprises imposing a barrier between the food item and the environment effective to prevent the release of a pest attracting aroma, said barrier comprising:
(a) a thermoplastic polymer web; and (b) uniformly dispersed in the web, an effective aroma permeant absorbing amount of the polymer compatible derivative of a cyclodextrin;
wherein the cyclodextrin is free of an inclusion complex compound.

67. The method of claim 66 wherein the thermoplastic polymer comprises a vinyl polymer comprising an alpha-olefin.

68. The method of claim 66 wherein the thermoplastic polymer comprises a chlorine containing vinyl polymer comprising vinyl chloride or vinylidene dichloride:

69. The method of claim 68 wherein the thermoplastic polymer comprises a poly(vinyl chloride-co-vinyl acetate) or a poly(vinyl chloride-co-vinylidene dichloride).

70. The method of claim 67 wherein the thermoplastic polymer comprises a polyvinylalcohol, poly(ethylene-co-vinyl alcohol),a poly(ethylene-co-methyl acrylate).

71. The method of claim 66 wherein the cyclodextrin comprises a ~-cyclodextrin.

72. The method of claim 66 wherein the cyclodextrin contains at least one substituent on a cyclodextrin primary carbon atom.

73. The method of claim 66 wherein the cyclodextrin comprises ~-cyclodextrin, ~-cyclodextrin, ~-cyclodextrin, or mixtures thereof.

74. The method of claim 66 wherein the thermoplastic web contains about 0.1 to about 5 wt-% of the polymer compatible cyclodextrin derivative.

75. A.method of manufacturing a thermoplastic polymer barrier composition, said method comprises:
(a) introducing a blend of an extrudable thermoplastic and a thermoplastic polymer compatible cyclodextrin derivative into a melt zone producing a compatible blend of the thermoplastic polymer and the polymer compatible cyclodextrin derivative having a temperature of about 390 to 410°F;
(b) extruding the compatible melt blend in an extrusion die producing an extrudate having a temperature of about 400 to 425°F; and (c) cooling the extrudate to form a film.

76. The process of claim 75 wherein the extrusion die comprises a linear extrusion die followed by a biaxially orientation step.

77. The method of claim 75 wherein the extrusion die comprises a circular extrusion die.

78. The method of claim 75 wherein the thermoplastic comprises a vinyl polymer comprising a .alpha.-olefin having a molecular weight of greater than 200,000 and a melt index of about 0.1 to 4.

79. The method of claim 75 wherein the thermoplastic polymer comprises a chlorine containing vinyl polymer comprising vinyl chloride or vinylidene dichloride.

80. The method of claim 79 wherein the thermoplastic polymer comprises a polyvinyl chloride co-vinyl acetate or a polyvinyl chloride co-vinylidene dichloride.

81. The method of claim 78 wherein the thermoplastic polymer comprises a polyvinylalcohol, poly(ethylene-co-vinyl alcohol) or a poly(ethylene-co-methyl acrylate).

82. The method of claim 75 wherein the cyclodextrin comprises a .beta.-cyclodextrin.

83. The method of claim 75 wherein the cyclodextrin comprises .alpha.-cyclodextrin, .beta.-cyclodextrin, .gamma.-cyclodextrin or mixtures thereof.

84. The method of claim 78 wherein the polymer is linear low density polyethylene.

85. A thermoplastic film composition, having improved barrier properties, the film composition comprising:
(a) a web comprising a thermoplastic polypropylene web having a melt index of 0.1 to 4 and a molecular weight greeter than 200,000; and (b) uniformly dispersed in the web, and about 0.1 to 5 wt-% of a permeant absorbing amount of a polymer compatible cyclodextrin derivative;
wherein the cyclodextrin is free of an inclusion complex compound.

86. The composition of claim 85 wherein the polymer molecular weight is greater than 250,000.

87. The composition of claim 85 wherein the polypropylene has a melt index of about 0.2 to 3.

88. The composition of claim 85 wherein the cyclodextrin derivative comprises an acetyl derivative of the cyclodextrin.

89. The composition of claim 85 wherein the cyclodextrin derivative comprises a trimethylsilyl derivative of the cyclodextrin.

90. The composition of claim 85 wherein the cyclodextrin comprises a .beta.-cyclodextrin.

91. The composition of claim 85 wherein the cyclodextrin derivative is formed on at least one primary carbon of the cyclodextrin.

92. The composition of claim 85 wherein the cyclodextrin comprises an .alpha.-cyclodextrin, a .beta.-cyclodextrin, a .gamma.-cyclodextrin or mixtures thereof.

93. The composition of claim 85 wherein the cyclodextrin is present at a concentration of about 0.1 to 2 wt-%.

94. The composition of claim 85 wherein the thermoplastic polypropylene comprises a web.

95. A thermoplastic-film composition, having improved barrier properties, the film composition comprising:

(a) a polymer web; and (b) a coating on the web comprising at least one layer of a film forming polymer and uniformly dispersed in the layer, an-effective permeant absorbing amount of a polymer compatible cyclodextrin derivative;
wherein-the cyclodextrin is substantially free of an inclusion complex compound.

96. The film of claim 95 wherein the film forming polymer comprises a vinyl polymer comprising an alpha-olefin.

97. The film of claim 96 wherein the film forming polymer comprises a polyethelene or a polypropylene.

98. The film of claim 95 wherein the film forming polymer comprises a chlorine containing polymer.

99. The film of claim 98 wherein the chlorine containing vinyl polymer comprising vinyl chloride or vinylidene dichloride.

100. The film of claim 98 wherein the film forming polymer comprises a polyvinyl chloride-co-vinyl acetate) or a poly(vinyl chloride-co-vinylidene dichloride).

101. A film of claim 95 wherein the film forming polymer comprises a polyvinylalcohol, poly(ethylene-co-vinyl alcohol), a polyethylene-co-acrylic acid) or a poly(ethylene-co-methyl acrylate).

102. The film of claim 95 wherein the cyclodextrin derivative comprises a .beta.-cyclodextrin derivative.

103. The film of claim 95 wherein the cyclodextrin derivative contains at least one substituent on a cyclodextrin-primary carbon atom.

104. The film of claim 95 wherein the cyclodextrin comprises .alpha.-cyclodextrin, .beta.-cyclodextrin, .gamma.-cyclodextrin or mixtures thereof.

105. The film of claim 95 wherein the coating contains about 0.1 to 10 wt-% of the polymer compatible cyclodextrin derivative.

106. A laminate comprising at least two films, at least one film comprising the film of claim 1.