US20030208016A1

US20030208016A1 - Radical polymerizable compositions containing polycyclic olefins

Info

Publication number: US20030208016A1
Application number: US10/353,774
Authority: US
Inventors: Stephen Dershem; Kevin Forrestal; Puwei Liu
Original assignee: Henkel Loctite Corp
Current assignee: Henkel Loctite Corp
Priority date: 2001-02-07
Filing date: 2003-01-27
Publication date: 2003-11-06
Also published as: WO2002062859A3; US20030008992A1; AU2002234039A1; WO2002062859A2; US6521731B2

Abstract

In accordance with the present invention, there are provided free-radical polymerizable compositions comprising polycyclic olefins, wherein the polycyclic olefins contain little, if any, cyclopentenyl unsaturation. As a result, these olefins are sufficiently reactive with the propagating free-radicals during cure to provide a highly crosslinked thermoset resin. Moreover, invention compositions comprise high molecular weight polycyclic olefins having low volatility. Accordingly, the observed undesirable weight loss upon cure of prior art thermosetting compositions is considerably reduced. Further provided by the present invention are compositions comprising functionalized polycyclic olefin monomers. These functionalized olefin monomers provide additional benefits such as increased adhesion to a variety of surfaces and greater control over glass transition temperatures.

Description

RELATED APPLICATIONS

This application is a continuation in part of U.S. patent application Ser. No. 09/779,694, filed Feb. 7, 2001, now pending, which is incorporated by reference in its entirety.[0001]

FIELD OF THE INVENTION

The present invention relates to compositions containing polycyclic olefins which polymerize under free-radical conditions to generate crosslinked polymers and copolymers. The invention relates particularly to polycyclic olefins which primarily contain bicycloheptenyl unsaturation units.

BACKGROUND OF THE INVENTION

Polymers and copolymers synthesized from polycyclic olefin monomers have attracted much interest from the scientific community due to the desirable properties often exhibited by these materials. Cyclic olefin copolymers (COC's) possess a unique combination of properties such as low density, low moisture absorption, low birefringence, high transparency, and high strength. Depending on the polycyclic olefin monomer and the polymerization conditions, materials can also be produced having a wide range of glass transition temperatures. As a result, these materials are being tested for use in diverse applications such as electronics, CD-ROM disks, optical lenses, barrier films, and medical appliances.

A particularly attractive characteristic displayed by polycyclic olefin monomers is the ability to polymerize via a variety of reaction mechanisms. It is well-known that polycyclic olefins can be polymerized and/or copolymerized free-radically, cationically, or coordinatively using organometallic catalysts. Due to this mechanistic flexibility, a wide variety of functionalized comonomers can be incorporated into the cyclic olefin copolymer, which provides further control over the bulk properties of the material.

Since polycyclic olefin monomers have the ability to polymerize free-radically, these monomers have been explored as potential candidates for use in free-radical cured thermosetting compositions. Indeed, polycyclic olefins have been shown to readily copolymerize with electron deficient olefins. Thermosetting resins incorporating polycyclic olefins can be expected to have many desirable properties, such as high Tg, hydrophobicity, and low shrinkage upon cure. However, in order to obtain these desirable properties in a thermoset resin, the polycyclic olefin must be of a certain minimum molecular weight (i.e., the volatility of the olefin should be low) and must be sufficiently reactive with the propagating free radicals during cure to produce a highly crosslinked thermoset network.

Unfortunately, most common and inexpensive polycyclic olefin monomers, such as norbornene, norbornadiene, dicyclopentadiene (DCPD), and the like, are deficient in these areas. Specifically, norbornene, norbornadiene, and DCPD are too volatile for use in many thermoset applications. In addition, the cyclopentenyl unsaturation of DCPD is insufficiently reactive for many thermoset applications. Indeed, it is well known that the cyclopentenyl double bond is far less reactive than the norbornenyl double bond, due to the low ring strain associated with the cyclopentenyl ring (relative to the bicycloheptenyl group). Moreover, the allylic hydrogen atoms on the cyclopentenyl rings may contribute to chain transfer reactions, thereby reducing the molecular weight of the growing polymer chains during cure. Thus, optimum free-radically cured thermosets incorporating polycyclic olefins are only produced when the polycyclic olefin has low volatility and contains little, if any, cyclopentenyl unsaturation.

Accordingly, there is a need for polycyclic olefin monomers which can be readily incorporated into free-radically cured thermosetting resin compositions, thereby producing thermosets having a unique combination of beneficial properties.

BRIEF DESCRIPTION OF THE INVENTION

In accordance with the present invention, there are provided free-radically polymerizable compositions comprising polycyclic olefins. Typically, the polycyclic olefins contain little, if any, cyclopentenyl unsaturation. As a result, these olefins are sufficiently reactive with the propagating free-radicals during cure to provide a highly crosslinked thermoset resin. Moreover, invention compositions comprise high molecular weight polycyclic olefins having low volatility. Accordingly, the undesirable weight loss upon cure observed with many thermosetting compositions is considerably reduced.

Further provided by the present invention are compositions comprising functionalized polycyclic olefin monomers. These functionalized olefin monomers provide additional benefits such as increased adhesion to a variety of surfaces as well as greater control over glass transition temperatures.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with the present invention, there are provided free-radically polymerizable compositions comprising

(A) at least one polycyclic olefin monomer, the monomer having at least one terminal norbornenyl functional group; preferably the monomer contains little, if any, cyclopentenyl unsaturation,

(B) one or more free-radical curing monomers, and

(C) at least one thermally activated free-radical curing catalyst.

As employed herein, a polycyclic olefin containing “cyclopentenyl unsaturation” refers to a cyclopentene ring fused to another hydrocarbon ring at adjacent carbons of the cyclopentene ring rather than in a 1,3 fashion. For example, DCPD is a polycyclic olefin containing cyclopentenyl unsaturation.

In one embodiment, polycyclic olefin monomers contemplated for use in the practice of the present invention have the following structures:

wherein:

each R ¹is

(a) independently hydrogen, alkyl or substituted alkyl, and or

(b) —X—Y, wherein:

X is an optional bridging group,

Y is a reactive heterocyclic group or a reactive substituted aryl group;

each x is independently 0, 1 or 2, and

n=0 to about 8.

As employed herein, “reactive,” when describing a particular group, refers to the ability of that group to participate in a free radical polymerization reaction, for example, by addition polymerization or by a chain transfer mechanism. For example, a reactive heterocyclic group is a heterocyclic group, as defined herein, which is capable of undergoing addition to a growing polymer.

Reactive heterocyclic groups and reactive substituted aryl groups contemplated for use in the practice of the present invention are optionally substituted and include maleimides, succinimides, itaconimides, epoxy groups, oxazolines, cyanate ester-substituted aryls, oxazines, and the like.

In presently preferred embodiments of the present invention, X is an alkylene or oxyalkylene comprising up to about 20 atoms, or X is a siloxane, and Y is an optionally substituted maleimide or oxazine. In a particularly preferred embodiment, Y is a benzoxazine.

In another embodiment, polycyclic olefin monomers contemplated for use in the practice of the present invention have the following structure:

wherein:

R ¹, x, and n are as defined above, and

Q is a bridging group.

In some such embodiments, Q is siloxane or —K _0,1—R′—K_0,1-, wherein R′ is optionally substituted and is an alkylene, an arylene or a polycyclic hydrocarbylene, and each K is independently —O—, —C(O)—, —NH—, —C(O)—NH—, —O—C(O)—NH—, —C(O)—O—, —NH—C(O)—NH—, or —O—C(O)—O—.

In preferred embodiments, Q is a tetramethyldisiloxane. In further such embodiments, the siloxane is 1,3-bis-bicyclo[2.2.1]hept-5-en-2-yl-1,1,3,3-tetramethyl-disiloxane or 1,3-bis-(2-bicyclo[2.2.1]hept-5-en-2-yl-ethyl)-1,1,3,3-tetramethyl-disiloxane.

Free-radical curing monomers contemplated for use in the practice of the present invention include maleimides, succinimides, itaconimides, unsaturated anhydrides, (meth)acrylates, styrenes, cyanate esters, vinyl esters, vinyl ethers, divinyl compounds, allyl amides, and the like.

Maleimides, succinimides (also referred to herein as nadimides), and itaconimides contemplated for use in the practice of the present invention as component (B) have the following structures:

wherein:

m=1-15,

p=0-15,

each R ²is independently selected from hydrogen or lower alkyl, and

J is a monovalent or a polyvalent moiety comprising organic or organosiloxane radicals, and combinations of two or more thereof.

In one embodiment, J is a monovalent or polyvalent radical selected from the group consisting of hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl, substituted heteroatom-containing hydrocarbyl, hydrocarbylene, substituted hydrocarbylene, heteroatom-containing hydrocarbylene, substituted heteroatom-containing hydrocarbylene, polysiloxane, polysiloxane-polyurethane block copolymer, and combinations of two or more thereof, optionally containing one or more linkers selected from the group consisting of a covalent bond, —O—, —S—, —NR—, —O—C(O)—, —O—C(O)—O—, —O—C(O)—NR—, —NR—C(O)—, —NR—C(O)—O—, —NR—C(O)—NR—, —S—C(O)—, —S—C(O)—O—, —S—C(O)—NR—, —O—S(O) ₂—, —O—S(O)₂—O—, —O—S(O)₂—NR—, —O—S(O)—, —O—S(O)—O—, —O—S(O)—NR—, —O—NR—C(O)—, —O—NR—C(O)—O—, —O—NR—C(O)—NR—, —NR—O—C(O)—, —NR—O—C(O)—O—, —NR—O—C(O)—NR—, —O—NR—C(S)—, —O—NR—C(S)—O—, —O—NR—C(S)—NR—, —NR—O—C(S)—, —NR—O—C(S)—O—, —NR—O—C(S)—NR—, —O—C(S)—, —O—C(S)—O—, —O—C(S)—NR—, —NR—C(S)—, —NR—C(S)—O—, —NR—C(S)—NR—, —S—S(O)₂—, —S—S(O)₂—O—, —S—S(O)₂—NR—, —NR—O—S(O)—, —NR—O—S(O)—O—, —NR—O—S(O)—NR—, —NR—O—S(O)₂—, —NR—O—S(O)₂—O—, —NR—O—S(O)₂—NR—, —O—NR—S(O)—, —O—NR—S(O)—O—, —O—NR—S(O)—NR—, —O—NR—S(O)₂—O—, —O—NR—S(O)₂—NR—, —O—NR—S(O)₂—, —O—P(O)R₂—, —S—P(O)R₂—, —NR—P(O)R₂—, wherein each R is independently hydrogen, alkyl or substituted alkyl, and combinations of any two or more thereof.

As employed herein, “hydrocarbyl” comprises any organic radical wherein the backbone thereof comprises carbon and hydrogen only. Thus, hydrocarbyl embraces alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, aryl, alkylaryl, arylalkyl, arylalkenyl, alkenylaryl, arylalkynyl, alkynylaryl, and the like.

As employed herein, “substituted hydrocarbyl” comprises any of the above-referenced hydrocarbyl groups further bearing one or more substituents selected from hydroxy, alkoxy (of a lower alkyl group), mercapto (of a lower alkyl group), cycloalkyl, substituted cycloalkyl, heterocyclic, substituted heterocyclic, aryl, substituted aryl, heteroaryl, substituted heteroaryl, aryloxy, substituted aryloxy, halogen, trifluoromethyl, cyano, nitro, nitrone, amino, amido, —C(O)H, acyl, oxyacyl, carboxyl, carbamate, dithiocarbamoyl, sulfonyl, sulfonamide, sulfuryl, and the like.

As employed herein, “alkyl” refers to saturated straight or branched chain hydrocarbon radical having in the range of 1 up to about 500 carbon atoms. “Lower alkyl” refers to alkyl groups having in the range of 1 up to about 5 carbon atoms. “Substituted alkyl” refers to alkyl groups further bearing one or more substituents as set forth above.

As employed herein, “alkenyl” refers to straight or branched chain hydrocarbyl groups having at least one carbon-carbon double bond, and typically having in the range of about 2 up to 500 carbon atoms, and “substituted alkenyl” refers to alkenyl groups further bearing one or more substituents as set forth above.

As employed herein, “alkynyl” refers to straight or branched chain hydrocarbyl groups having at least one carbon-carbon triple bond, and typically having in the range of about 2 up to 500 carbon atoms, and “substituted alkynyl” refers to alkynyl groups further bearing one or more substituents as set forth above.

As employed herein, “cycloalkyl” refers to a cyclic ring-containing groups containing in the range of about 3 up to about 8 carbon atoms, and “substituted cycloalkyl” refers to cycloalkyl groups further bearing one or more substituents as set forth above.

As employed herein, “cycloalkenyl” refers to cyclic ring-containing groups containing in the range of 3 up to 20 carbon atoms and having at least one carbon-carbon double bond, and “substituted cycloalkenyl” refers to cycloalkenyl groups further bearing one or more substituents as set forth above.

As employed herein, “aryl” refers to aromatic groups having in the range of 6 up to 14 carbon atoms and “substituted aryl” refers to aryl groups further bearing one or more substituents as set forth above.

As employed herein, “alkylaryl” refers to alkyl-substituted aryl groups and “substituted alkylaryl” refers to alkylaryl groups further bearing one or more substituents as set forth above.

As employed herein, “arylalkyl” refers to aryl-substituted alkyl groups and “substituted arylalkyl” refers to arylalkyl groups further bearing one or more substituents as set forth above.

As employed herein, “arylalkenyl” refers to aryl-substituted alkenyl groups and “substituted arylalkenyl” refers to arylalkenyl groups further bearing one or more substituents as set forth above.

As employed herein, “alkenylaryl” refers to alkenyl-substituted aryl groups and “substituted alkenylaryl” refers to alkenylaryl groups further bearing one or more substituents as set forth above.

As employed herein, “arylalkynyl” refers to aryl-substituted alkynyl groups and “substituted arylalkynyl” refers to arylalkynyl groups further bearing one or more substituents as set forth above.

As employed herein, “alkynylaryl” refers to alkynyl-substituted aryl groups and “substituted alkynylaryl” refers to alkynylaryl groups further bearing one or more substituents as set forth above.

As employed herein, “heterocyclic” refers to cyclic (i.e., ring-containing) groups containing one or more heteroatoms (e.g., N, O, S, or the like) as part of the ring structure, and having in the range of 3 up to 14 carbon atoms and “substituted heterocyclic” refers to heterocyclic groups further bearing one or more substituents as set forth above. Exemplary heterocyclic moieties include saturated rings, unsaturated rings, and aromatic heteroatom-containing ring systems, e.g., epoxy, tetrahydrofuran, oxazoline, oxazine, pyrrole, pyridine, furan, and the like.

As employed herein, “hydrocarbylene” refers to divalent straight or branched chain hydrocarbyl groups including alkylene groups, alkenylene groups, alkynylene groups, cycloalkylene groups, heterocycloalkylene groups, arylene groups, heteroarylene groups, alkylarylene groups, arylalkylene groups, arylalkenylene groups, arylalkynylene groups, alkenylarylene groups, alkynylarylene groups, and the like; and “substituted hydrocarbylene” refers to hydrocarbylene groups further bearing one or more substituents as set forth above.

As employed herein, “alkylene” refers to saturated, divalent straight or branched chain hydrocarbyl groups typically having in the range of about 2 up to about 500 carbon atoms, and “substituted alkylene” refers to alkylene groups further bearing one or more substituents as set forth above.

As employed herein, “alkenylene” refers to divalent straight or branched chain hydrocarbyl groups having at least one carbon-carbon double bond, and typically having in the range of about 2 up to 500 carbon atoms, and “substituted alkenylene” refers to alkenylene groups further bearing one or more substituents as set forth above.

As employed herein, “alkynylene” refers to divalent straight or branched chain hydrocarbyl groups having at least one carbon-carbon triple bond, and typically having in the range of about 2 up to 500 carbon atoms, and “substituted alkynylene” refers to alkynylene groups further bearing one or more substituents as set forth above.

As employed herein, “cycloalkylene” refers to divalent ring-containing groups containing in the range of about 3 up to about 8 carbon atoms, and “substituted cycloalkylene” refers to cycloalkylene groups further bearing one or more substituents as set forth above.

As employed herein, “heterocycloalkylene” refers to divalent cyclic (i.e., ring-containing) groups containing one or more heteroatoms (e.g., N, O, S, or the like) as part of the ring structure, and having in the range of 3 up to 14 carbon atoms and “substituted heterocycloalkylene” refers to heterocycloalkylene groups further bearing one or more substituents as set forth above.

As employed herein, “cycloalkenylene” refers to divalent ring-containing groups containing in the range of about 3 up to about 8 carbon atoms and having at least one carbon-carbon double bond, and “substituted cycloalkenylene” refers to cycloalkenylene groups further bearing one or more substituents as set forth above.

As employed herein, “arylene” refers to divalent aromatic groups typically having in the range of 6 up to 14 carbon atoms and “substituted arylene” refers to arylene groups further bearing one or more substituents as set forth above.

As employed herein, “alkylarylene” refers to alkyl-substituted divalent aryl groups typically having in the range of about 7 up to 16 carbon atoms and “substituted alkylarylene” refers to alkylarylene groups further bearing one or more substituents as set forth above.

As employed herein, “arylalkylene” refers to aryl-substituted divalent alkyl groups typically having in the range of about 7 up to 16 carbon atoms and “substituted arylalkylene” refers to arylalkylene groups further bearing one or more substituents as set forth above.

As employed herein, “arylalkenylene” refers to aryl-substituted divalent alkenyl groups typically having in the range of about 8 up to 16 carbon atoms and “substituted arylalkenylene” refers to arylalkenylene groups further bearing one or more substituents as set forth above.

As employed herein, “arylalkynylene” refers to aryl-substituted divalent alkynyl groups typically having in the range of about 8 up to 16 carbon atoms and “substituted arylalkynylene” refers to arylalkynylene group further bearing one or more substituents as set forth above.

As employed herein, “alkenylarylene” refers to alkenyl-substituted divalent aryl groups typically having in the range of about 7 up to 16 carbon atoms and “substituted alkenylarylene” refers to alkenylarylene groups further bearing one or more substituents as set forth above.

As employed herein, “alkynylarylene” refers to alkynyl-substituted divalent aryl groups typically having in the range of about 7 up to 16 carbon atoms and “substituted alkynylarylene” refers to alkynylarylene groups further bearing one or more substituents as set forth above.

As employed herein, “heteroarylene” refers to divalent aromatic groups containing one or more heteroatoms (e.g., N, O, S or the like) as part of the aromatic ring, and typically having in the range of 3 up to 14 carbon atoms and “substituted heteroarylene” refers to heteroarylene groups further bearing one or more substituents as set forth above.

As employed herein, “polysiloxane-polyurethane block copolymers” refer to polymers containing both at least one polysiloxane (soft) block and at least one polyurethane (hard) block.

When one or more of the above described monovalent or polyvalent groups contain one or more of the above described linkers to form the “J” appendage of a maleimide, succinimide or itaconimide group, as readily recognized by those of skill in the art, a wide variety of organic chains can be produced, such as, for example, oxyalkyl, thioalkyl, aminoalkyl, carboxylalkyl, oxyalkenyl, thioalkenyl, aminoalkenyl, carboxyalkenyl, oxyalkynyl, thioalkynyl, aminoalkynyl, carboxyalkynyl, oxycycloalkyl, thiocycloalkyl, aminocycloalkyl, carboxycycloalkyl, oxycloalkenyl, thiocycloalkenyl, aminocycloalkenyl, carboxycycloalkenyl, heterocyclic, oxyheterocyclic, thioheterocyclic, aminoheterocyclic, carboxyheterocyclic, oxyaryl, thioaryl, aminoaryl, carboxyaryl, heteroaryl, oxyheteroaryl, thioheteroaryl, aminoheteroaryl, carboxyheteroaryl, oxyalkylaryl, thioalkylaryl, aminoalkylaryl, carboxyalkylaryl, oxyarylalkyl, thioarylalkyl, aminoarylalkyl, carboxyarylalkyl, oxyarylalkenyl, thioarylalkenyl, aminoarylalkenyl, carboxyarylalkenyl, oxyalkenylaryl, thioalkenylaryl, aminoalkenylaryl, carboxyalkenylaryl, oxyarylalkynyl, thioarylalkynyl, aminoarylalkynyl, carboxyarylalkynyl, oxyalkynylaryl, thioalkynylaryl, aminoalkynylaryl or carboxyalkynylaryl, oxyalkylene, thioalkylene, aminoalkylene, carboxyalkylene, oxyalkenylene, thioalkenylene, aminoalkenylene, carboxyalkenylene, oxyalkynylene, thioalkynylene, aminoalkynylene, carboxyalkynylene, oxycycloalkylene, thiocycloalkylene, aminocycloalkylene, carboxycycloalkylene, oxycycloalkenylene, thiocycloalkenylene, aminocycloalkenylene, carboxycycloalkenylene, oxyarylene, thioarylene, aminoarylene, carboxyarylene, oxyalkylarylene, thioalkylarylene, aminoalkylarylene, carboxyalkylarylene, oxyarylalkylene, thioarylalkylene, aminoarylalkylene, carboxyarylalkylene, oxyarylalkenylene, thioarylalkenylene, aminoarylalkenylene, carboxyarylalkenylene, oxyalkenylarylene, thioalkenylarylene, aminoalkenylarylene, carboxyalkenylarylene, oxyarylalkynylene, thioarylalkynylene, aminoarylalkynylene, carboxy arylalkynylene, oxyalkynylarylene, thioalkynylarylene, aminoalkynylarylene, carboxyalkynylarylene, heteroarylene, oxyheteroarylene, thioheteroarylene, aminoheteroarylene, carboxyheteroarylene, heteroatom-containing di- or polyvalent cyclic moiety, oxyheteroatom-containing di- or polyvalent cyclic moiety, thioheteroatom-containing di- or polyvalent cyclic moiety, aminoheteroatom-containing di- or polyvalent cyclic moiety, carboxyheteroatom-containing di- or polyvalent cyclic moiety, and the like.

In another embodiment, maleimides, succinimides, and itaconimides contemplated for use in the practice of the present invention have the structures I, II, or III wherein,

m=1-6,

p=0-6, and

J is

(a) saturated straight chain alkyl or branched chain alkyl, optionally containing optionally substituted aryl moieties as substituents on the alkyl chain or as part of the backbone of the alkyl chain, and wherein the alkyl chains have up to about 20 carbon atoms;

(b) a siloxane having the structure: —(C(R ³)₂)_d—[Si(R⁴)₂—O]_f—Si(R⁴)₂—(C(R³)₂)_e—, —(C(R³)₂)_d—C(R³)—C(O)O—(C(R³)₂)_d—[Si(R⁴)₂—O]_f—Si(R⁴)₂—(C(R³)₂)_e—O(O)C—(C(R³)₂)_e—, or —(C(R³)₂)_d—C(R³)—O(O)C—(C(R³)₂)_d—[Si(R⁴)₂—O]_f—Si(R⁴)₂—(C(R³)₂)e-C(O)O—(C(R³)₂)_e—wherein:

each R ³is independently hydrogen, alkyl or substituted alkyl,

each R ⁴is independently hydrogen, lower alkyl or aryl,

d=1-10,

e=1-10, and

f=1-50;

(c) a polyalkylene oxide having the structure:

—[(CR₂)_r—O—]_f—(CR₂)_s—

wherein:

each R is independently hydrogen, alkyl or substituted alkyl,

r=1-10,

s=1-10, and

f is as defined above;

(d) aromatic groups having the structure:

wherein each Ar is a monosubstituted, disubstituted or trisubstituted aromatic or heteroaromatic ring having in the range of 3 up to 10 carbon atoms, and Z is:

(i) saturated straight chain alkylene or branched chain alkylene, optionally containing saturated cyclic moieties as substituents on the alkylene chain or as part of the backbone of the alkylene chain, or

(ii) polyalkylene oxides having the structure:

—[(CR₂)_r—O—]_q—(CR₂)_s—

wherein each R is independently defined as above, r and s are each defined as above, and q falls in the range of 1 up to 50;

(e) di- or tri-substituted aromatic moieties having the structure:

wherein each R is independently defined as above, t falls in the range of 2 up to 10, u falls in the range of 2 up to 10, and Ar is as defined above;

(f) aromatic groups having the structure:

wherein:

each R is independently defined as above,

t=2-10,

k=1, 2 or 3,

g=1 up to about 50,

each Ar is as defined above,

E is —O— or —NR ⁵—, wherein R⁵is hydrogen or lower alkyl; and

W is

(i) straight or branched chain alkyl, alkylene, oxyalkylene, alkenyl, alkenylene, oxyalkenylene, ester, or polyester,

(ii) a siloxane having the structure (C(R ³)₂)_d—[Si(R⁴)₂—O]_f—Si(R⁴)₂—(C(R³)₂)_e—, —(C(R³)₂)_d—C(R³)—C(O)O—(C(R³)₂)_d—[Si(R⁴)₂—O]_f—Si(R⁴)₂—(C(R³)₂)_e—O(O)C—(C(R³)₂)_e—, or —(C(R³)₂)_d—C(R³)—O(O)C—(C(R³)₂)_d—[Si(R⁴)₂—O]_f—Si(R⁴)₂—(C(R³)₂)_e—C(O)O—(C(R³)₂)_e— wherein,

each R ³is independently hydrogen, alkyl or substituted alkyl,

each R ⁴is independently hydrogen, lower alkyl or aryl,

d=1-10,

e=1-10, and

f=1-50; or

(iii) a polyalkylene oxide having the structure:

—[(CR₂)_r—O—]_f—(CR₂)_s—

wherein:

each R is independently hydrogen, alkyl or substituted alkyl,

r=1-10,

s=1-10, and

f is as defined above;

optionally containing substituents selected from hydroxy, alkoxy, carboxy, nitrile, cycloalkyl or cycloalkenyl;

(g) a urethane group having the structure:

R⁷—U—C(O)—NR⁶—R⁸—NR⁶—C(O)—(O—R⁸—O—C(O)—NR⁶—R⁸—NR⁶—C(O))_v—U—R⁸—

wherein:

each R ⁶is independently hydrogen or lower alkyl;

each R ⁷is independently an alkyl, aryl, or arylalkyl group having 1 to 18 carbon atoms;

each R ⁸is an alkyl or alkyloxy chain having up to about 100 atoms in the chain, optionally substituted with Ar;

U is —O—, —S—, —N(R)—, or —P(L) _1,2— wherein R as defined above, and wherein each L is independently ═O, S, —OR or —R; and

v=0-50;

(h) polycyclic alkenyl; or

(i) mixtures of any two or more thereof.

In another embodiment, J is of sufficient length to render liquid the maleimide, succinimide, itaconimide or combinations of two or more thereof. In some such embodiments, m=1, 2 or 3, and J is a branched chain alkyl, alkylene or alkylene oxide of sufficient length and branching to render liquid the maleimide, succinimide, itaconimide or combinations of two or more thereof.

In preferred embodiments, the maleimide is N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-butylmaleimide, N-t-butylmaleimide, N-hexylmaleimide, N-2-ethylhexylmaleimide, N-cyclohexylmaleimide, N-octylmaleimide, N-decylmaleimide, N-dodecylmaleimide, N-phenylmaleimide, 2-methyl-N-phenylmaleimide, 4-methyl-N-phenylmaleimide, 2-ethyl-N-phenylmaleimide, 4-ethyl-N-phenylmaleimide, 2,6-diethyl-N-phenylmaleimide, and the like, or a mixture of any two or more thereof.

In some embodiments, the free-radical curing monomers contemplated for use in the practice of the present invention are mixtures of one or more of the above-described maleimides, succinimides, and itaconimides with one or more unsaturated anhydrides, (meth)acrylates, styrenes, cyanate esters, vinyl esters, divinyl compounds, and the like.

In preferred embodiments, anhydrides contemplated for use in the practice of the present invention include maleic anhydride, citraconic anhydride, itaconic anhydride, and the like, or Diels-Alder adducts of maleic anhydride, citraconic anhydride, itaconic anhydride, and the like, and cyclopentadiene. Diels-Alder adducts contemplated for use in the practice of the present invention have the following structure:

wherein each V is independently an alkyl or substituted alkyl, each x is independently 0, 1 or 2, and m=0-9.

Exemplary (meth)acrylates contemplated for use in the practice of the present invention may be prepared from a host of different compounds. As used herein, the terms (meth)acrylic and (meth)acrylate are used synonymously with regard to the monomer and monomer-containing component. The terms (meth)acrylic and (meth)acrylate include acrylic, methacrylic, acrylate and methacrylate. The (meth)acrylates may comprise one or more members selected from a monomer represented by:

(a) the formula:

wherein:

G is hydrogen, halogen, or an alkyl having from 1 to 4 carbon atoms,

R ¹⁰has from 1 to 16 carbon atoms and is an alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkaryl, aralkyl, or aryl group, optionally substituted or interrupted with silane, silicon, oxygen, halogen, carbonyl, hydroxyl, ester, carboxylic acid, urea, urethane, carbamate, amine, amide, sulfur, sulfonate, or sulfone;

(b) urethane acrylates or ureide acrylates represented by the formula:

wherein:

G is hydrogen, halogen, or an alkyl having from 1 to 4 carbon atoms;

R ¹¹is a divalent alkyl, cycloalkyl, aromatic, or arylalkyl group, bound through a carbon atom or carbon atoms thereof indicated at the —O— atom and —X— atom or group;

X is —O—, —NH—, or —N(alkyl)-, in which the alkyl radical has from 1 to 8 carbon atoms;

z is 2 to 6; and

R ¹²is a z-valent cycloalkyl, aromatic, or arylalkyl group bound through a carbon atom or carbon atoms thereof to the one or more NH groups; or

(c) a di- or tri-(meth)acrylate selected from polyethylene glycol di(meth)acrylates, bisphenol-A di(meth)acrylates, tetrahydrofurane di(meth)acrylates, hexanediol di(meth)acrylate, trimethylol propane tri(meth)acrylate, and the like, as well as combinations of any two or more thereof.

Suitable polymerizable (meth)acrylate monomers include triethylene glycol dimethacrylate, tripropylene glycol diacrylate, tetraethylene glycol dimethacrylate, diethylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol dimethacrylate, pentaerythritol tetraacrylate, trimethylol propane triacrylate, trimethylol propane trimethacrylate, di-pentaerythritol monohydroxypentaacrylate, pentaerythritol triacrylate, bisphenol-A-ethoxylate dimethacrylate, trimethylolpropane ethoxylate triacrylate, trimethylolpropane propoxylate triacrylate, bisphenol-A-diepoxide dimethacrylate, and the like, as well as combinations of any two or more thereof.

Additionally, (meth)acrylate monomers contemplated for use herein include polyethylene glycol di(meth)acrylates, bisphenol-A di(meth)acrylates, tetrahydrofurane (meth)acrylates and di(meth)acrylates, citronellyl acrylate and citronellyl methacrylate, hydroxypropyl (meth)acrylate, hexanediol di(meth)acrylate, trimethylol propane tri(meth)acrylate, tetrahydrodicyclopentadienyl (meth)acrylate, ethoxylated trimethylol propane triacrylate, triethylene glycol acrylate, triethylene glycol methacrylate, and the like, as well as combinations of any two or more thereof.

Exemplary cyanate esters contemplated for use in the practice of the present invention include compounds such as those described in U.S. Pat. Nos. 5,358,992, 5,447,988, 5,489,641, 5,646,241, 5,718,941 and 5,753,748, each of which are hereby incorporated by reference herein in their entirety. For instance, cyanate esters useful as a component in the inventive compositions may be chosen from dicyanatobenzenes, tricyanatobenzenes, dicyanatonaphthalenes, tricyanatonaphthalenes, dicyanato-biphenyl, bis(cyanatophenyl)methanes and alkyl derivatives thereof, bis(dihalocyanatophenyl)propanes, bis(cyanatophenyl)ethers, bis(cyanatophenyl)sulfides, bis(cyanatophenyl)propanes, tris(cyanatophenyl)phosphites, tris(cyanatophenyl)phosphates, bis(halocyanatophenyl)methanes, cyanated novolac, bis[cyanatophenyl(methylethylidene)]benzene, cyanated bisphenol-terminated thermoplastic oligomers, and the like, as well as combinations of any two or more thereof.

More specifically contemplated for use herein are aryl compounds having at least one cyanate ester group on each molecule; such compounds may generally be represented by the formula Ar(OCN) _m, where Ar is an aromatic radical and m is an integer from 2 to 5. The aromatic radical Ar should contain at least 6 carbon atoms, and may be derived, for example, from aromatic hydrocarbons, such as phenyl, biphenyl, naphthalene, anthracene, or the like. The aromatic radical Ar may also be derived from a polynuclear aromatic hydrocarbon in which at least two aromatic rings are attached to each other through a bridging group. Also included are aromatic radicals derived from novolac-type phenolic resins—i.e., cyanate esters of these phenolic resins. Ar may also contain further ring-attached, non-reactive substituents.

Examples of such cyanate esters include, for instance, 1,3-dicyanatobenzene; 1,4-dicyanatobenzene; 1,3,5-tricyanatobenzene; 1,3-, 1,4-, 1,6-, 1,8-, 2,6- or 2,7-dicyanatonaphthalene; 1,3,6-tricyanatonaphthalene; 4,4′-dicyanato-biphenyl; bis(4-cyanatophenyl)methane and 3,3′,5,5′-tetramethyl bis(4-cyanatophenyl)methane; 2,2-bis(3,5-dichloro-4-cyanatophenyl)propane; 2,2-bis(3,5-dibromo-4-dicyanatophenyl)propane; bis(4-cyanatophenyl)ether; bis(4-cyanatophenyl)sulfide; 2,2-bis(4-cyanatophenyl)propane; tris(4-cyanatophenyl)-phosphite; tris(4-cyanatophenyl)phosphate; bis(3-chloro-4-cyanatophenyl)methane; cyanated novolac; 1,3-bis[4-cyanatophenyl-1-(methylethylidene)]benzene, cyanated bisphenol-terminated polycarbonate or other thermoplastic oligomer, and the like, as well as combinations of any two or more thereof.

Particularly desirable cyanate esters contemplated for use herein are available commercially from Ciba Specialty Chemicals, Tarrytown, N.Y. under the tradename “AROCY” [1,1-di(4-cyanatophenylethane)]. The structures of three “AROCY” cyanate esters are shown below:

Divinyl compounds contemplated for use in the practice of the present invention are present such that there is no greater than one equivalent of divinyl compound plus the polycyclic olefin per equivalent of bismaleimide. The divinyl compounds have the following structure:

CHR⁹═CR⁹-M_0,1-D-M_0,1-CR⁹═CHR⁹

wherein:

each R ⁹is independently hydrogen, lower alkyl or aryl,

each M is independently —O—, —O—C(O)—, —C(O)— or —C(O)O—, and

D is a monovalent or a polyvalent moiety comprising organic or organosiloxane radicals, and combinations of two or more thereof.

In one embodiment D is a monovalent or polyvalent radical selected from the group consisting of hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl, substituted heteroatom-containing hydrocarbyl, hydrocarbylene, substituted hydrocarbylene, heteroatom-containing hydrocarbylene, substituted heteroatom-containing hydrocarbylene, polysiloxane, polysiloxane-polyurethane block copolymer, and combinations of two or more thereof, optionally containing one or more linkers selected from the group consisting of a covalent bond, —O—, —S—, —NR—, —O—C(O)—, —O—C(O)—O—, —O—C(O)—NR—, —NR—C(O)—, —NR—C(O)—O—, —NR—C(O)—NR—, —S—C(O)—, —S—C(O)—O—, —S—C(O)—NR—, —O—S(O) ₂—, —O—S(O)₂—O—, —O—S(O)₂—NR—, —O—S(O)—, —O—S(O)—O—, —O—S(O)—NR—, —O—NR—C(O)—, —O—NR—C(O)—O—, —O—NR—C(O)—NR—, —NR—O—C(O)—, —NR—O—C(O)—O—, —NR—O—C(O)—NR—, —O—NR—C(S)—, —O—NR—C(S)—O—, —O—NR—C(S)—NR—, —NR—O—C(S)—, —NR—O—C(S)—O—, —NR—O—C(S)—NR—, —O—C(S)—, —O—C(S)—O—, —O—C(S)—NR—, —NR—C(S)—, —NR—C(S)—O—, —NR—C(S)—NR—, —S—S(O)₂—, —S—S(O)₂—O—, —S—S(O)₂—NR—, —NR—O—S(O)—, —NR—O—S(O)—O—, —NR—O—S(O)—NR—, —NR—O—S(O)₂—, —NR—O—S(O)₂—O—, —NR—O—S(O)₂—NR—, —O—NR—S(O)—, —O—NR—S(O)—O—, —O—NR—S(O)—NR—, —O—NR—S(O)₂—O—, —O—NR—S(O)₂—NR—, —O—NR—S(O)₂—, —O—P(O)R₂—, —S—P(O)R₂—, —NR—P(O)R₂—, wherein each R is independently hydrogen, alkyl or substituted alkyl, and combinations of any two or more thereof.

In a further embodiment, the above divinyl compounds include those where D is

(b) a siloxane having the structure: —(C(R ³)₂)_d—[Si(R⁴)₂—O]_f—Si(R⁴)₂—(C(R³)₂)_e—, —(C(R³)₂)_d—C(R³)—C(O)O—(C(R³)₂)_d—[Si(R⁴)₂—O]_f—Si(R⁴)₂—(C(R³)₂)_e—O(O)C—(C(R³)₂)_e—, or —(C(R³)₂)_d—C(R³)—O(O)C—(C(R³)₂)_d—[Si(R⁴)₂—O]_f—Si(R⁴)₂—(C(R³)₂)_e—C(O)O—(C(R³)₂)_e— wherein:

each R ³is independently hydrogen, alkyl or substituted alkyl,

each R ⁴is independently hydrogen, lower alkyl or aryl,

d=1-10,

e=1-10, and

f=1-50;

(c) a polyalkylene oxide having the structure:

—[(CR₂)_r—O—]_f—(CR₂)_s—

wherein:

each R is independently hydrogen, alkyl or substituted alkyl,

r=1-10,

s=1-10, and

f is as defined above;

(d) aromatic groups having the structure:

(ii) polyalkylene oxides having the structure:

—[(CR₂)_r—O—]_q—(CR₂)_s—

(e) di- or tri-substituted aromatic moieties having the structure:

wherein each R is independently defined as above, t falls in the range of 2 up to 10, u falls in the range of 2 up to 10, and Ar is

(f) aromatic groups having the structure:

wherein:

each R is independently defined as above,

t=2-10,

k=1, 2 or 3,

g=1 up to about 50,

each Ar is as defined above,

E is —O— or —NR ⁵—, wherein R⁵is hydrogen or lower alkyl; and

W is

(ii) a siloxane having the structure —(C(R ³)₂)_d—[Si(R⁴)₂—O]_f—Si(R⁴)₂—(C(R³)₂)_e—, —(C(R³)₂)_d—C(R³)—C(O)O—(C(R³)₂)_d—[Si(R⁴)₂—O]_f—Si(R⁴)₂—(C(R³)₂)_e—O(O)C—(C(R³)₂)_e—, or —(C(R³)₂)_d—C(R³)—O(O)C—(C(R³)₂)_d—[Si(R⁴)₂—O]_f—Si(R⁴)₂—(C(R³)₂)_e—C(O)O—(C(R³)₂)_e— wherein,

each R ³is independently hydrogen, alkyl or substituted alkyl,

each R ⁴is independently hydrogen, lower alkyl or aryl,

d=1-10,

e=1-10, and

f=1-50; or

(iii) a polyalkylene oxide having the structure:

—[(CR₂)_r—O—]_f—(CR₂)_s—

wherein:

each R is independently hydrogen, alkyl or substituted alkyl,

r=1-10,

s=1-10, and

f is as defined above;

(g) a urethane group having the structure:

R⁷—U—C(O)—NR⁶—R⁸—NR⁶—C(O)—(O—R⁸—O—C(O)—NR⁶—R¹—NR⁶—C(O))_v—U—R⁸—

wherein:

each R ⁶is independently hydrogen or lower alkyl;

U is —O—, —S—, —N(R)—, or —P(L) _1,2— wherein R as defined above, and wherein each L is independently ═O, ═S, —OR or —R; and

v=0-50;

(h) polycyclic alkenyl; or

(i) mixtures of any two or more thereof.

Curing catalysts contemplated for use in the practice of the present invention include free-radical initiators such as peroxy esters, peroxy carbonates, hydroperoxides, alkylperoxides, arylperoxides, azo compounds, and the like. In one embodiment, the curing catalyst is present in the range of 0.2 up to about 5 wt % based on the total weight of the composition.

The incorporation of effective amounts of polycyclic olefin monomers into a free-radical curing thermoset imparts many useful properties to the final crosslinked material. It has been observed that these monomers increase the glass transition temperature of the thermoset while decreasing the coefficient of thermal expansion. Additionally, thermosets which contain polycyclic olefins have increased toughness versus those without these monomers. A further desirable benefit attributable to these monomers when incorporated into a thermoset is low shrinkage upon cure. Thus, effective amounts of polycyclic olefin monomers are those amounts sufficient to impart one or more of these improved properties to the thermoset resin. Typically, in various embodiments, effective amounts of polycyclic olefin monomers range from about 5 to about 98 weight percent, preferably from about 25 to about 75 weight percent, and more preferably from about 40 to about 60 weight percent of the free-radical curing thermoset.

All of these properties are important in a variety of end use applications, such as, for example, optical disks, barrier films, medical appliances, and the like. In particular, the properties provided by these monomers are especially useful in semiconductor packaging applications such as, for example, die-attach adhesives. Invention compositions may be readily incorporated into die-attach formulations containing further components such as, for example, conductive fillers, to provide hydrophobic, low-shrinkage die-attach pastes. The conductive fillers may be electrically conductive or thermally conductive.

Thus, the present invention provides assemblies employing such die-attach formulations. Further, the present invention provides methods for adhesively attaching a device to a substrate, including curing an invention die-attach formulation positioned between the substrate and the surface. In some such embodiments the device is a semiconductor die and the substrate is a lead frame. In other such embodiments the lead frame is a copper lead frame.

The present invention also provides adhesive film compositions suitable for use in die-attach and other applications. Such compositions comprise a thermoset resin, as described above, and a thermoplastic elastomer. The latter is a block copolymer having at least one unit of the general formula (A-B) or (A-B-A), wherein A is a non-elastomeric polymer block and B is an elastomeric polymer block that is the polymerization product of optionally substituted olefin monomers and/or optionally substituted conjugated diene monomers.

As employed herein, the term “block copolymer” refers to polymers composed of two or more different polymer subunits joined end to end. An elastomeric polymer block is a polymer subunit that exhibits rubber-like properties; i.e. it is soft at room temperature and deforms under stress but recovers upon the removal of stress. A non-elastomeric polymer block is a polymer subunit that is hard at room temperature and does not stretch. Butadiene is an example of an elastomeric polymer block, while polystyrene is an example of a non-elastomeric block.

Thermoplastic elastomers contemplated for use in the practice of the present invention include, for example, polystyrene-polybutadiene-polystyrene block copolymers, polystyrene-polyisoprene-polystyrene block copolymers, polystyrene-polydimethylbutadiene-polystyrene block copolymers, polybutadiene-polyacrylonitrile block copolymers, and the like. Preferably, the block copolymer is a polystyrene-polybutadiene-polystyrene block copolymer or a polybutadiene-polyacrylonitrile block copolymer.

In a further aspect of the invention, there are provided assemblies employing such adhesive film formulations and methods for making the same. Thus the invention provides methods for adhesively attaching a device to a substrate comprising subjecting a sufficient quantity of an invention adhesive composition positioned between a substrate and a device to conditions suitable to cure the adhesive formulation. Devices contemplated for use in the practice of the present invention include any surface mount component such as, for example, semiconductor die, resistors, capacitors, and the like. Preferably, devices contemplated for use in the practice of invention methods are semiconductor dies. Substrates contemplated for use include metal substrates (e.g., lead frames), organic substrates (e.g., laminates, ball grid arrays, polyamide films), and the like.

Various conditions suitable to cure invention adhesive film compositions may be used. For example, some embodiments comprise subjecting invention film adhesive compositions to a temperature of at least about 150° C. but less than about 300° C. for about 0.5 up to about 2 minutes. This rapid, short duration heating can be accomplished in a variety of ways, e.g., with an in-line heated rail, a belt furnace, or the like. Alternative embodiments comprise subjecting invention film adhesive compositions to a temperature in the range of about 120° C. up to about 200° C. for a period of about 15 minutes up to about 60 minutes. These conditions can be readily produced in a variety of ways, such, for example, by placing invention film adhesive compositions in a curing oven. In still other embodiments, conditions suitable to cure invention film adhesive compositions may further comprise subjecting invention film adhesive compositions to a pre-cure at a temperature high enough to increase the viscosity of the liquid adhesive and reduce tackiness but low enough to prevent a complete cure. Such pre-cured adhesive film compositions may then undergo a final cure as described above to give the fully cured adhesive.

Polycyclic olefin monomers contemplated for use in the practice of the present invention contain at least one unit of bicycloheptenyl unsaturation and are readily synthesized via Diels-Alder chemistry, as shown below in Scheme 1.

The temperatures required for this reaction to proceed are generally between 150 and 250° C. It is necessary to use an autoclave to conduct this reaction since all of the reactants have boiling points well below 100° C. Cyclopentadiene need not be used directly since this component of the reaction can be readily generated in situ from the retro Diels-Alder reaction of dicyclopentadiene. Both norbornene and norbornadiene are commercially available and convenient to use. Alternatively, these materials could also be generated in situ from ethylene or acetylene and cyclopentadiene, respectively, as shown in Scheme 2.

As shown above, functionalized polycyclic olefin monomers are readily obtained via Diels-Alder chemistry. Further examples of functionalized polycyclic olefin monomers are shown below in Scheme 3. The reaction between cyclopentadiene and strong dienophiles such as, for example, maleic anhydride and N-alkyl maleimides, produces polycyclic olefin monomers which can increase adhesion of the thermoset material to a variety of surfaces.

The polycyclic olefin monomers described in Schemes 1-3 are all high molecular weight analogs of norbornene or norbornadiene. As such, their vapor pressure is extremely low, resulting in very little outgassing or weight loss during high temperature cure. It is of note that these high molecular weight species are sufficiently reactive with electron deficient monomers to produce highly crosslinked networks. Indeed, electron rich polycyclic olefins readily copolymerize free radically with a variety of electron poor olefins, to give alternating copolymers, as shown in Scheme 4.

Thus, the polycyclic olefin monomers contemplated for use in the practice of the present invention can be copolymerized with a variety of electron deficient monomers to give a thermosetting composition which is sufficiently reactive to provide a highly crosslinked network. This reactivity can be extended to a variety of functionalized electron deficient olefins, resulting in thermoset resins with a wide range of attractive properties.

Invention compounds are particularly useful in the microelectronics industry, where properties such as hydrophobicity, ionic purity, low shrinkage upon cure, and the like, are extremely important. Indeed, formulations comprising invention compounds are attractive candidates for a variety of electronic packaging applications, such as, for example, die-attach pastes. The use of invention compounds in die-attach formulations provides die-attach pastes with high glass transition temperatures. This feature is particularly important since state of the art microprocessors generate more heat during operation than previous generations of microprocessors.

The properties provided by invention compounds are also desirable in other microelectronic packaging applications, such as, for example, underfill, encapsulants, solder mask, and the like.

The invention will now be described in greater detail by reference to the following non-limiting examples.

EXAMPLE 1

The preparation of 1,3-bis-bicyclo[2.2.1]hept-5-en-2-yl-1,1,3,3-tetramethyl-disiloxane, shown below, is described in this example. [0229]
Bicyclo[2.2.1]hepta-2,5-diene (120 grams, 1.3 moles) and 1,1,3,3-tetramethyldisiloxane (27 grams, 0.2 moles) were placed into a 500 ml round-bottom flask equipped with a magnetic stir bar and a condenser. Three drops of platinum catalyst (Gelest “SIP6831.0”) were added to this mixture at room temperature while it was stirred magnetically. The system was then heated to 70° C. and stirred at this temperature for another eight hours. The reaction was monitored via FTIR and was judged to be complete once the Si—H peak (2200 cm[0230] ⁻¹) disappeared. The bicyclo[2.2.1]hepta-2,5-diene excess was stripped off in a rotary evaporator. The crude reaction product residue was then dissolved in 200 ml toluene and passed over a thin bed of silica gel. The toluene was then removed by rotary evaporation to yield a faintly yellow, low viscosity, liquid. The product was subjected to a nitrogen gas sparge at 60° C. for six hours to remove the last trace of volatiles. The final product was obtained in 96% yield, based on the initial 1,1,3,3-tetramethyldisiloxane limiting reagent used.

EXAMPLE 2

The preparation of 1,3-bis(2-bicyclo[2.2.1]hept-5-en-2-yl-ethyl)-1,1,3,3-tetramethyl-disiloxane, shown below, is described in this example. [0231]
5-Vinyl-2-norbornene (72 grams, 0.6 moles) and 1,1,3,3-tetramethyldisiloxane (33.6 grams, 0.25 moles) were placed into a 500 ml round-bottom flask equipped with a magnetic stir bar and condenser. One drop of platinum catalyst (Gelest “SIP6831.0”) was added to the magnetically stirred mixture at room temperature. A vigorous reaction ensued. The reaction mix was stirred at room temperature for another hour. The completion of the reaction was also determined by the total disappearance of the [0232]
Si—H peak via FTIR. The excess 5-vinyl-2-norbornene was then stripped off in a rotary evaporator. The residue was dissolved in 200 ml toluene and passed over a thin layer of silica gel. The toluene was removed on a rotary evaporator and the residue was then sparged under nitrogen gas at 60° C. for several hours. The final product was obtained in 98% yield (based on the amount of 1,1,3,3-tetramethyldisiloxane originally charged). The product was an almost colorless, low viscosity liquid. [0233]

EXAMPLE 3

The invention compounds described in Examples 1 and 2 were tested in thermoset compositions with a bismaleimide monomer, X-BMI, shown below. [0234]
The results of these tests are described in Examples 4-6. [0235]

EXAMPLE 4

Stoichiometric mixtures (i.e. one equivalent of bisnorbornenyl monomer per maleimide equivalent) were made. Mix A contained a miscible blend of X-BMI; 1,3-bis-bicyclo[2.2.1]hept-5-en-2-yl-1,1,3,3-tetramethyldisiloxane (“compound I”) and two percent by weight dicumyl peroxide. Mix B contained a miscible blend of X-BMI; 1,3-bis-(2-bicyclo[2.2.1]hept-5-en-2-yl-ethyl)-1,1,3, 3-tetramethyldisiloxane (“compound II”), and two percent by weight dicumyl peroxide. A control mix was also made containing only X-BMI and two weight percent dicumyl peroxide. [0236]
These mixtures were tested for tensile adhesion on copper. Each mixture was used to bond ten aluminum studs to freshly cleaned copper slugs. The parts were cured at 200° C. for twenty minutes. Tensile adhesion was then measured on all of the parts using a Sebastian III stud pull instrument. The results of that test are shown in Table 1. [0237]

TABLE 1

Adhesion Test of BMI/NBisnorbornene Mixtures

Invention Mix A Invention Mix B Control Mix

Adhesion (pounds Adhesion (pounds Adhesion (pounds

Part # force) force) force)

1 33 52 37

2 30 35 19

3 26 39 32

4 27 44 30

5 23 46 28

6 41 32 38

7 36 32 35

8 32 34 37

9 28 41 27

10 30 38 34

Average 30 39 32

σ_n−1 5.8 6.5 5.9
The adhesion values for the bisnorbornene/BMI mixtures were substantially equivalent to that of the all-BMI control. This result suggested that the bisnorbornene compounds did co-cure with the bismaleimide since there was no loss of adhesion (which would have been expected if these co-monomers had remained as “uncured plasticisers” in the thermoset bondline). [0238]

EXAMPLE 5

The mixtures described in Example 3 were subjected to thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) experiments. Included in these tests were two additional mixtures containing compounds I and II, each catalyzed with two percent of dicumyl peroxide. These new mixtures were designated “mix C” and “mix D”, respectively. A third, additional mixture was made that contained X-BMI and 33.7% of 2-decyl-1-tetradecanol. The purpose of this last mixture was to have an additional control for weight loss and cure energy using a non-reactive diluent having a molecular weight intermediate between compounds I and II. This last mixture was designated “mix E”. The TGA and DSC results for all of these mixtures and the control are shown in Table 2. [0239]

TABLE 2

TGA and DSC Results for Test Mixtures

Invention Invention Invention Invention Comparison

Mix A Mix B Mix C Mix D Mix E Control

TGA weight 3.75% 3.14% 82.3% 54.5% 29.7% 1.98%

loss @ 350° C.

DSC cure 296 264 106 57 192 284

exotherm

(J/gram)
The results in Table 2 clearly show that co-cure of norbornenyl functional monomers and maleimides does occur. Compounds I and II did exhibit some limited free radical cure by themselves, but this cure was far from complete as demonstrated by the large weight loss and low cure exotherm. The relatively low weight loss values for the A and B mixes as well as their high exotherm energies supports the conclusion that norbornenyl and maleimide co-cure does occur. Finally, comparison mix E added further proof of co-cure. This control had weight loss and cure results consistent with that of a non-reactive diluent. The weight loss of mix E, furthermore, demonstrated that compounds I and II weren't simply trapped within a cured BMI matrix since the weight loss at 350° C. was nearly equal to known added weight of the 2-decyl-1-tetradecanol. [0240]

EXAMPLE 6

Invention compositions were also tested for moisture uptake. Invention mixtures A and B were cured (200° C. for one hour) to give void free, cylindrical slugs that were approximately one centimeter in diameter and ranging between two and five centimeters in length. Similar slugs were prepared from the catalyzed BMI control mix. Three slugs from each group were included in a moisture up-take test. All of these slugs were placed in boiling deionized water for several hours. Initially, all of the samples had some weight loss, but this initial weight loss ceased after about 290 hours in the boiling water. This initial weight loss period was used to level all of the slugs by removing any residual water extractable components. The slugs were removed from the water after this initial water extraction step and then re-dried at 200° C. for eight hours. The dried parts were placed back in fresh deionized water and boiled for another twenty-four hours. The moisture up-take results for these test parts are summarized in Table 3. [0241]

TABLE 3

Moisture Up-take Results on Cured Resin

Samples after 24 Hrs in Boiling Water

Invention Mix A Invention Mix B X-BMI Control

+0.43% +0.37% +0.64%

+0.49% +0.35% +0.66%

+0.45% +0.38% +0.61%
These moisture uptake results are consistent with reduced moisture affinity in the mixtures containing compounds I and II. The X-BMI itself is a very hydrophobic monomer. The results of this test clearly show that the hydrophobicity of the bismaleimide thermoset is further improved by the addition of select norbornenyl co-monomers. [0242]

Claims

What is claimed is:

1. A free-radical polymerizable thermoset resin composition comprising:

(A) at least one polycyclic olefin monomer, the monomer having at least one terminal norbornenyl functional group,

(B) one or more free-radical curing monomers, and

(C) at least one thermally activated free-radical curing catalyst.

2. A composition of claim 1, wherein the polycyclic olefin monomer contains little, if any, cyclopentenyl unsaturation.

3. A composition according to claim 1, wherein the polycyclic olefin monomer comprises the structure:

wherein:

each R¹is

(a) independently hydrogen, alkyl or substituted alkyl, or

(b) —X—Y, wherein:

X is an optional bridging group,

Y is a reactive heterocyclic group or a reactive substituted aryl group;

each x is independently 0, 1 or 2, and n=0 to about 8.

4. A composition according to claim 3, wherein bridging group X is an alkylene or oxyalkylene comprising up to about 20 atoms.

5. A composition according to claim 3, wherein bridging group X is a siloxane.

6. A composition according to claim 3, wherein Y is optionally substituted and is selected from the group consisting of a maleimide, a succinimide, an itaconimide, an epoxy group, an oxazoline, a cyanate ester-substituted aryl, and an oxazine.

7. A composition according to claim 3, wherein Y is an optionally substituted maleimide or oxazine.

8. A composition according to claim 7, wherein Y is an oxazine.

9. A composition according to claim 8, wherein the oxazine is a benzoxazine.

10. A composition according to claim 1, wherein the polycyclic olefin monomer comprises the structure:

wherein:

R¹, x, and n are as defined above, and

Q is a bridging group.

11. A composition according to claim 10, wherein Q comprises a siloxane or —K_0,1—R′—K_0,1—, wherein

R′ is optionally substituted and is an alkylene, an arylene or a polycyclic hydrocarbylene, and

each K is independently —O—, —C(O)—, —NH—, —C(O)—NH—, —O—C(O)—NH—, —C(O)—O—, —NH—C(O)—NH—, or —O—C(O)—O—.

12. A composition according to claim 10, wherein Q comprises siloxane.

13. A composition according to claim 11, wherein the siloxane is a tetramethyldisiloxane.

14. A composition according to claim 11, wherein the siloxane is 1,3-bis-bicyclo[2.2.1]hept-5-en-2-yl-1,1,3,3-tetramethyl-disiloxane or 1,3-bis-(2-bicyclo[2.2.1]hept-5-en-2-yl-ethyl)-1,1,3,3-tetramethyl-disiloxane.

15. A composition according to claim 1 wherein the one or more free-radical curing monomers are selected from the group consisting of a maleimide, succinimide, itaconimide, unsaturated anhydride, (meth)acrylate, styrene, cyanate ester, vinyl ester, vinyl ether, divinyl compound, and allyl amide.

16. A composition according to claim 15, wherein the maleimide, succinimide, and itaconimide comprise, respectively, the structures I, II and III:

wherein:

each R²is independently selected from hydrogen or lower alkyl, and

17. A composition according to claim 16, wherein:

J is a monovalent or polyvalent radical selected from the group consisting of hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl, substituted heteroatom-containing hydrocarbyl, hydrocarbylene, substituted hydrocarbylene, heteroatom-containing hydrocarbylene, substituted heteroatom-containing hydrocarbylene, polysiloxane, polysiloxane-polyurethane block copolymer, and combinations of two or more thereof, optionally containing one or more linkers selected from the group consisting of a covalent bond, —O—, —S—, —NR—, —O—C(O)—, —O—C(O)—O—, —O—C(O)—NR—, —NR—C(O)—, —NR—C(O)—O—, —NR—C(O)—NR—, —S—C(O)—, —S—C(O)—O—, —S—C(O)—NR—, —O—S(O)₂—, —O—S(O)₂—O—, —O—S(O)₂—NR—, —O—S(O)—, —O—S(O)—O—, —O—S(O)—NR—, —O—NR—C(O)—, —O—NR—C(O)—O—, —O—NR—C(O)—NR—, —NR—O—C(O)—, —NR—O—C(O)—O—, —NR—O—C(O)—NR—, —O—NR—C(S)—, —O—NR—C(S)—O—, —O—NR—C(S)—NR—, —NR—O—C(S)—, —NR—O—C(S)—O—, —NR—O—C(S)—NR—, —O—C(S)—, —O—C(S)—O—, —O—C(S)—NR—, —NR—C(S)—, —NR—C(S)—O—, —NR—C(S)—NR—, —S—S(O)₂—, —S—S(O)₂—O—, —S—S(O)₂—NR—, —NR—O—S(O)—, —NR—O—S(O)—O—, —NR—O—S(O)—NR—, —NR—O—S(O)₂—, —NR—O—S(O)₂—O—, —NR—O—S(O)₂—NR—, —O—NR—S(O)—, —O—NR—S(O)—O—, —O—NR—S(O)—NR—, —O—NR—S(O)₂—O—, —O—NR—S(O)₂—NR—, —O—NR—S(O)₂—, —O—P(O)R₂—, —S—P(O)R₂—, —NR—P(O)R₂—, wherein each R is independently hydrogen, alkyl or substituted alkyl, and combinations of any two or more thereof.

18. A composition according to claim 16, wherein:

m=1-6,

p=0-6, and

J is

(b) a siloxane having the structure: —(C(R³)₂)_d—[Si(R⁴)₂—O]_f—Si(R⁴)₂—(C(R³)₂)_e—, —(C(R³)₂)_d—C(R³)—C(O)O—(C(R³)₂)_d—[Si(R⁴)₂—O]_f—Si(R⁴)₂—(C(R³)₂)_e—O(O)C—(C(R³)₂)_e—, or —(C(R³)₂)_d—C(R³)—O(O)C—(C(R³)₂)_d—[Si(R⁴)₂—O]_f—Si(R⁴)₂—(C(R³)₂)_e—C(O)O—(C(R³)₂)_e— wherein:

each R³is independently hydrogen, alkyl or substituted alkyl,

each R⁴is independently hydrogen, lower alkyl or aryl,

d=1-10,

e=1-10, and

f=1-50;

(c) a polyalkylene oxide having the structure:

—[(CR₂)_r—O—]_f—(CR₂)_s—

wherein:

each R is independently hydrogen, alkyl or substituted alkyl,

r=1-10,

s=1-10, and

f is as defined above;

(d) aromatic groups having the structure:

(ii) polyalkylene oxides having the structure:

—[(CR₂)_r—O—]_q—(CR₂)_s—

(e) di- or tri-substituted aromatic moieties having the structure:

(f) aromatic groups having the structure:

wherein:

each R is independently defined as above,

t=2-10,

k=1, 2 or 3,

g=1 up to about 50, each Ar is as defined above,

E is —O— or —NR⁵—, wherein R⁵is hydrogen or lower alkyl; and

W is

(ii) a siloxane having the structure —(C(R³)₂)_d—[Si(R⁴)₂—O]_f—Si(R⁴)₂—(C(R³)₂)_e—, —(C(R³)₂)_d—C(R³)—C(O)O—(C(R³)₂)_d—[Si(R⁴)₂—O]_f—Si(R⁴)₂—(C(R³)₂)_e—O(O)C—(C(R³)₂)_e—, or —(C(R³)₂)_d—C(R³)—O(O)C—(C(R³)₂)_d—[Si(R⁴)₂—O]_f—Si(R⁴)₂—(C(R³)₂)_e—C(O)O—(C(R³)₂)_e— wherein,

each R³is independently hydrogen, alkyl or substituted alkyl,

each R⁴is independently hydrogen, lower alkyl or aryl,

d=1-10,

e=1-10, and

f=1-50; or

(iii) a polyalkylene oxide having the structure:

—[(CR₂)_r—O—]_f—(CR₂)_s—

wherein:

each R is independently hydrogen, alkyl or substituted alkyl,

r=1-10,

s=1-10, and

f is as defined above;

(g) a urethane group having the structure:

wherein:

each R⁶is independently hydrogen or lower alkyl;

each R⁷is independently an alkyl, aryl, or arylalkyl group having 1 to 18 carbon atoms;

each R⁸is an alkyl or alkyloxy chain having up to about 100 atoms in the chain, optionally substituted with Ar;

U is —O—, —S—, —N(R)—, or —P(L)_1,2— wherein R as defined above, and wherein each L is independently ═O, ═S, —OR or —R; and

v=0-50;

(h) polycyclic alkenyl; or

(i) mixtures of any two or more thereof.

19. A composition according to claim 16, wherein J is of sufficient length to render liquid at ambient temperature the maleimide, succinimide, itaconimide or combinations of two or more thereof.

20. A composition according to claim 16, wherein,

m=1, 2 or 3, and

J is a branched chain alkyl, alkylene or alkylene oxide of sufficient length and branching to render liquid at ambient temperature the maleimide, succinimide, itaconimide or combinations of two or more thereof.

21. A composition according to claim 16, wherein the maleimide is selected from the group consisting of N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-butylmaleimide, N-t-butylmaleimide, N-hexylmaleimide, N-2-ethylhexylmaleimide, N-cyclohexylmaleimide, N-octylmaleimide, N-decylmaleimide, N-dodecylmaleimide, N-phenylmaleimide, 2-methyl-N-phenylmaleimide, 4-methyl-N-phenylmaleimide, 2-ethyl-N-phenylmaleimide, 4-ethyl-N-phenylmaleimide, 2,6-diethyl-N-phenylmaleimide, and a mixture of any two or more thereof.

22. A composition according to claim 15, wherein the free-radical curing comonomer is unsaturated anhydride.

23. A composition according to claim 22, wherein the unsaturated anhydride is selected from the group consisting of maleic anhydride, citraconic anhydride, itaconic anhydride, and cyclopentadiene Diels-Alder adducts thereof.

24. A composition according to claim 23, wherein the Diels-Alder adducts comprise the structure:

wherein:

each V is independently an alkyl or substituted alkyl,

each x is independently 0, 1 or 2, and

m=0-9.

25. A composition according to claim 15, wherein the monomer is a (meth)acrylate.

26. A composition according to claim 25, wherein the (meth)acrylate is selected from the group consisting of

(a) the formula:

wherein:

G is hydrogen, halogen, or an alkyl having from 1 to 4 carbon atoms, R¹⁰has from 1 to 16 carbon atoms and is an alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkaryl, aralkyl, or aryl group, optionally substituted or interrupted with silane, silicon, oxygen, halogen, carbonyl, hydroxyl, ester, carboxylic acid, urea, urethane, carbamate, amine, amide, sulfur, sulfonate, or sulfone;

(b) urethane acrylates or ureide acrylates represented by the formula:

wherein:

G is hydrogen, halogen, or an alkyl having from 1 to 4 carbon atoms;

R¹¹is a divalent alkyl, cycloalkyl, aromatic, or arylalkyl group, bound through a carbon atom or carbon atoms thereof indicated at the —O— atom and —X— atom or group;

z is 2 to 6; and

R¹²is a z-valent cycloalkyl, aromatic, or arylalkyl group bound through a carbon atom or carbon atoms thereof to the one or more NH groups; or

(c) a di- or tri-(meth)acrylate selected from polyethylene glycol di(meth)acrylates, bisphenol-A di(meth)acrylates, tetrahydrofurane di(meth)acrylates, hexanediol di(meth)acrylate, trimethylol propane tri(meth)acrylate, and combinations of any two or more thereof.

27. A composition according to claim 26, wherein the (meth)acrylate is selected from the group consisting of triethylene glycol dimethacrylate, tripropylene glycol diacrylate, tetraethylene glycol dimethacrylate, diethylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol dimethacrylate, pentaerythritol tetraacrylate, trimethylol propane triacrylate, trimethylol propane trimethacrylate, di-pentaerythritol monohydroxypentaacrylate, pentaerythritol triacrylate, bisphenol-A-ethoxylate dimethacrylate, trimethylolpropane ethoxylate triacrylate, trimethylolpropane propoxylate triacrylate, bisphenol-A-diepoxide dimethacrylate, and combinations of any two or more thereof.

28. A composition according to claim 26, wherein the (meth)acrylate is selected from the group consisting of polyethylene glycol di(meth)acrylates, bisphenol-A di(meth)acrylates, tetrahydrofurane (meth)acrylates and di(meth)acrylates, citronellyl acrylate and citronellyl methacrylate, hydroxypropyl (meth)acrylate, hexanediol di(meth)acrylate, trimethylol propane tri(meth)acrylate, tetrahydrodicyclopentadienyl (meth)acrylate, ethoxylated trimethylol propane triacrylate, triethylene glycol acrylate, triethylene glycol methacrylate, and combinations of any two or more thereof.

29. A composition according to claim 15, wherein the monomer is a divinyl compound.

30. A composition according to claim 29, wherein the divinyl compound comprises the structure:

CHR⁹═CR⁹-M_0,1-D-M_0,1-D-M_0,1-CR⁹═CHR⁹

wherein:

each R⁹is independently hydrogen, lower alkyl or aryl,

each M is independently —O—, —O—C(O)—, —C(O)— or —C(O)O—, and

D is a monovalent or a polyvalent moiety comprising organic or organosiloxane radicals, and combinations of any two or more thereof.

31. A composition according to claim 30, wherein D is a monovalent or polyvalent radical selected from the group consisting of hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl, substituted heteroatom-containing hydrocarbyl, hydrocarbylene, substituted hydrocarbylene, heteroatom-containing hydrocarbylene, substituted heteroatom-containing hydrocarbylene, polysiloxane, polysiloxane-polyurethane block copolymer, and combinations of two or more thereof, optionally containing one or more linkers selected from the group consisting of a covalent bond, —O—, —S—, —NR—, —O—C(O)—, —O—C(O)—O—, —O—C(O)—NR—, —NR—C(O)—, —NR—C(O)—O—, —NR—C(O)—NR—, —S—C(O)—, —S—C(O)—O—, —S—C(O)—NR—, —O—S(O)₂—, —O—S(O)₂—O—, —O—S(O)₂—NR—, —O—S(O)—, —O—S(O)—O—, —O—S(O)—NR—, —O—NR—C(O)—, —O—NR—C(O)—O—, —O—NR—C(O)—NR—, —NR—O—C(O)—, —NR—O—C(O)—O—, —NR—O—C(O)—NR—, —O—NR—C(S)—, —O—NR—C(S)—O—, —O—NR—C(S)—NR—, —NR—O—C(S)—, —NR—O—C(S)—O—, —NR—O—C(S)—NR—, —O—C(S)—, —O—C(S)—O—, —O—C(S)—NR—, —NR—C(S)—, —NR—C(S)—O—, —NR—C(S)—NR—, —S—S(O)₂—, —S—S(O)₂—O—, —S—S(O)₂—NR—, —NR—O—S(O)—, —NR—O—S(O)—O—, —NR—O—S(O)—NR—, —NR—O—S(O)₂—, —NR—O—S(O)₂—O—, —NR—O—S(O)₂—NR—, —O—NR—S(O)—, —O—NR—S(O)—O—, —O—NR—S(O)—NR—, —O—NR—S(O)₂—O—, —O—NR—S(O)₂—NR—, —O—NR—S(O)₂—, —O—P(O)R₂—, —S—P(O)R₂—, —NR—P(O)R₂—, wherein each R is independently hydrogen, alkyl or substituted alkyl, and combinations of any two or more thereof.

32. A composition according to claim 31, wherein D is

(b) a siloxane having the structure —(C(R³)₂)_d—[Si(R⁴)₂—O]_f—Si(R⁴)₂—(C(R³)₂)_e—, —(C(R³)₂)_d—C(R³)—C(O)O—(C(R³)₂)_d—[Si(R⁴)₂—O]_f—Si(R⁴)₂—(C(R³)₂)_e—O(O)C—(C(R³)₂)_e—, or —(C(R³)₂)_d—C(R³)—O(O)C—(C(R³)₂)_d—[Si(R⁴)₂—O]_f—Si(R⁴)₂—(C(R³)₂)_e—C(O)O—(C(R³)₂)_e— wherein,

each R³is independently hydrogen, alkyl or substituted alkyl,

each R⁴is independently hydrogen, lower alkyl or aryl,

d=1-10,

e=1-10, and

f=1-50;

(c) a polyalkylene oxide having the structure:

—[(CR₂)_r—O—]_f—(CR₂)_s—

wherein:

each R is independently hydrogen, alkyl or substituted alkyl,

r=1-10,

s=1-10, and

f is as defined above;

(d) aromatic groups having the structure:

(ii) polyalkylene oxides having the structure:

—[(CR₂)_r—O—]_q—(CR₂)_s—

(e) di- or tri-substituted aromatic moieties having the structure:

(f) aromatic groups having the structure:

wherein:

each R is independently defined as above,

t=2-10,

k=1, 2 or 3,

g=1 up to about 50,

each Ar is as defined above,

E is —O— or —NR⁵—, wherein R⁵is hydrogen or lower alkyl; and

W is

each R³is independently hydrogen, alkyl or substituted alkyl,

each R⁴is independently hydrogen, lower alkyl or aryl,

d=1-10,

e=1-10, and

f=1-50; or

(iii) a polyalkylene oxide having the structure:

—[(CR₂)_r—O—]_f—(CR₂)_s—

wherein:

each R is independently hydrogen, alkyl or substituted alkyl,

r=1-10,

s=1-10, and

f is as defined above;

(g) a urethane group having the structure:

—R⁷—U—C(O)—NR⁶—R⁸—NR⁶—C(O)—(O—R⁸—O—C(O)—NR⁶—R⁸—NR⁶—C(O))_v—U—R⁸—

wherein:

each R⁶is independently hydrogen or lower alkyl;

v=0-50;

(h) polycyclic alkenyl; or

(i) mixtures of any two or more thereof.

33. A composition according to claim 1, wherein the curing catalyst is selected from the group consisting of peroxy ester, peroxy carbonate, hydroperoxide, alkylperoxide, arylperoxide, and an azo compound.

34. A die-attach formulation comprising:

(A) a thermoset resin composition according to claim 1, and

(B) a conductive filler.

35. A die-attach formulation according to claim 34 wherein the filler is electrically conductive.

36. A die-attach formulation according to claim 34 wherein the filler is thermally conductive.

37. In a die-attach formulation, the improvement comprising incorporating into the die-attach formulation an effective amount of a composition according to claim 1.

38. An assembly comprising a first article adhered to a second article by a cured aliquot of a die-attach formulation according to claim 34.

39. An assembly comprising a first article adhered to a second article by a cured aliquot of a die-attach formulation according to claim 35.

40. An assembly comprising a first article adhered to a second article by a cured aliquot of a die-attach formulation according to claim 36.

41. A method for adhesively attaching a device to a substrate, the method comprising curing a die-attach formulation according to claim 34 positioned between the substrate and the device.

42. A method according to claim 41, wherein the device is a semiconductor die and the substrate is a lead frame.

43. A method according to claim 41, wherein the lead frame is a copper lead frame.

44. An adhesive film formulation comprising:

(A) a thermoset resin composition according to claim 1, and

(B) a thermoplastic elastomer that is a block copolymer having at least one unit of the general formula (A-B) or (A-B-A), wherein A is a non-elastomeric polymer block and B is an elastomeric polymer block that is the polymerization product of optionally substituted olefin monomers and/or optionally substituted conjugated diene monomers.

45. A method for adhesively attaching a device to a substrate, the method comprising curing an adhesive film formulation according to claim 44 positioned between the substrate and the device.

46. A method according to claim 45, wherein the device is a semiconductor die and the substrate is a lead frame.

47. An assembly comprising a first article adhered to a second article by a cured aliquot of an adhesive film formulation according to claim 44.

48. In a free radical-polymerizable thermoset resin composition, the improvement comprising incorporating into the composition an effective amount of at least one polycyclic olefin monomer, the monomer having at least one terminal norbornenyl functional group.