Adhesive articles, adhesive compositions, and methods comprising a polymer and a polymerizable cycloolefin

Abstract

The present invention describes adhesive compositions and articles, the articles comprising a carrier substrate (e.g., a release liner or backing) and an adhesive composition disposed on the carrier substrate. The adhesive composition comprises at least 20 wt% of a polymer; an unpolymerized cyclic olefin; and an (e.g., latent) ring-opening metathesis polymerization catalyst or a precatalyst thereof. The polymer may have a Tg of less than 25 °C and / or may be an acrylic polymer. A bonding method is also described.

Description

SUMMARY OF THE INVENTION

[0001] In one embodiment, an adhesive article is described that includes a carrier substrate (e.g., a release liner or backing) and an adhesive composition disposed on the carrier substrate. The adhesive composition includes at least 20 wt% of a polymer having a glass transition temperature (Tg) less than 25 °C; unpolymerized cycloolefin; and a latent ring-opening metathesis polymerization catalyst or a pre-catalyst thereof.

[0002] In another embodiment, an adhesive composition is described that includes:

[0003] at least 20 wt% of a polymer; unpolymerized cycloolefin; and a latent ring-opening metathesis polymerization catalyst or a pre-catalyst thereof, wherein the catalyst or pre-catalyst can be activated by actinic radiation.

[0004] In another embodiment, an adhesive composition is described that includes:

[0005] at least 20 wt% of an acrylic polymer; unpolymerized cycloolefin; and a ring-opening metathesis polymerization catalyst or a pre-catalyst thereof.

[0006] In another embodiment, an adhesive composition is described that includes: at least 50 wt% of a polymer; unpolymerized cycloolefin; and a ring-opening metathesis polymerization catalyst or a pre-catalyst thereof.

[0007] In another embodiment, a bonding method is described that includes: providing an adhesive article or adhesive composition as described herein; disposing the adhesive between a first substrate and a second substrate; and polymerizing the cycloolefin. DETAILED DESCRIPTION

[0008] The adhesive compositions described herein include one or more unpolymerized cycloolefins. Cycloolefins are generally monounsaturated (i.e., monoolefins) or polyunsaturated (i.e., contain two or more carbon-carbon double bonds, or in other words, olefinic groups). The double bonds, or in other words, the ethylenically unsaturated groups are not part of (meth)acrylate or vinyl ether groups. Cycloolefins can be monocyclic or polycyclic (i.e., contain two or more cyclic groups). Cycloolefins can generally be strained or unstrained cycloolefins provided that the cycloolefin can participate in a ROMP reaction either alone or as part of a ROMP cycloolefin composition.

[0009] The polymerizable binder composition comprises cyclic diene monomers, including, for example, 1,3-cyclopentadiene, 1,3-cyclohexadiene, 1,4-cyclohexadiene, 5-ethyl-1,3-cyclohexadiene, 1,3-cycloheptadiene, cyclohexadiene, 1,5-cyclooctadiene, 1,3-cyclooctadiene, norbornadiene, cyclohexenyl norbornene, including their oligomers, such as dimers, trimers, tetramers, pentamers, etc. The polyolefin cyclic materials are suitable for thermosetting.

[0010] In some embodiments, the polymerizable binder composition comprises dicyclopentadiene (DCPD), depicted as follows:

[0011]

[0012] Various DCPD suppliers and purities can be used, such as Lyondell 108 (purity 94.6%), Veliscol UHP (purity 99%), Cymetech Ultrene (purities 97% and 99%), and Hitachi (purity 99+%).

[0013] In some embodiments, the composition comprises cyclopentadiene oligomers, including trimers, tetramers, pentamers, etc.; depicted as follows:

[0014] For cyclopentadiene oligomers, n is typically 3, 4, or 5.

[0015] In some embodiments, the composition comprises cyclic diene monomers in the absence of monoolefins.

[0016] In other embodiments, the composition further comprises cyclic monoolefins. Examples include cyclopentene, cyclohexene, cycloheptene, cyclooctene, cyclononene, cyclodecene, cycloundecene, cyclododecene, tricyclodecene, tetracyclodecene, octacyclodecene, and cycloeicosene, and their substituted forms, such as 1-methylcyclopentene, 1-ethylcyclopentene, 1-isopropylcyclohexene, 1-chloropentene, 1-fluorocyclopentene, 4-methylcyclopentene, 4-methoxy-cyclopentene, 4-ethoxy-cyclopentene, cyclopent-3-ene-thiol, cyclopent-3-ene, 4-methylthioalkyl-cyclopentene, 3-methylcyclohexene, 1-methylcyclooctene, 1,5-dimethylcyclooctene, etc.

[0017] In some embodiments, the composition further comprises norbornene, depicted as follows:

[0018]

[0019] Suitable norbornene monomers include substituted norbornenes such as norbornene dicarboxylic anhydride (nadic anhydride); and alkyl and cycloalkyl norbornenes including butyl norbornene, hexyl norbornene, octyl norbornene, decyl norbornene, and the like.

[0020] The cyclic olefin monomers and oligomers may optionally contain substituents provided that the monomers, oligomers or mixtures are suitable for metathesis reactions. The carbon atoms of the cyclic olefin moiety may optionally contain substituents derived from free radical moieties including halogens, pseudohalogens, alkyls, aryls, acyls, carboxyls, alkoxys, alkyl thiolates and aryl thiolates, aminos, aminoalkyls, etc., or where one or more carbon atoms have been replaced by, for example, silicon, oxygen, sulfur, nitrogen, phosphorus, antimony or boron. For example, the olefin may be substituted by one or more groups such as thiols, thioethers, ketones, aldehydes, esters, ethers, amines, amides, nitro groups, carboxylic acids, disulfides, carbonates, isocyanates, phosphates, phosphites, sulfates, sulfites, sulfonyls, carbodiimides, carbalkoxys, carbamates, halogens or pseudohalogens. Similarly, the olefin may be substituted by one or more groups such as C1-C20 alkyls, aryls, acyls, C1-C20 alcoholates, aryloxides, C3-C20 alkyl diketonates, aryl diketonates, C1-C20 carboxylates, aryl sulfonates, C1-C20 alkyl sulfonates, C1-C20 alkyl sulfenyls, aryl sulfenyls, C1-C20 alkyl sulfonyls, C1-C20 alkyl sulfinyls, C-C20 alkyl phosphates and aryl phosphates.

[0021] Preferred cyclic olefins may include dicyclopentadiene; tricyclopentadiene; dicyclohexadiene; norbornene; 5-methyl-2-norbornene; 5-ethyl-2-norbornene; 5-isobutyl-2-norbornene; 5,6-dimethyl-2-norbornene; 5-phenyl norbornene; 5-benzyl norbornene; 5-acetyl norbornene; 5-methoxycarbonyl norbornene; 5-ethoxycarbonyl-1-norbornene; 5-methyl-5-methoxy-carbonyl norbornene; 5-cyano norbornene; 5,5,6-trimethyl-2-norbornene; cyclohexenyl norbornene; endo,exo-5,6-dimethoxy norbornene; endo,endo-5,6-dimethoxy norbornene; endo,exo-5-6-dimethoxycarbonyl norbornene; endo,endo-5,6-dimethoxycarbonyl norbornene; 2,3-dimethoxy norbornene; norbornadiene; tricycloundecene; tetracyclododecene; 8-methyltetracyclododecene; 8-ethyl-tetracyclododecene; 8-methoxycarbonyltetracyclododecene; 8-methyl-8-tetracyclododecene; 8-cyanotetracyclododecene; pentacyclopentadecene; pentacyclohexadecene; higher order oligomers of cyclopentadiene such as cyclopentadiene tetramer, cyclopentadiene pentamer, etc.; and C2-C 12Hydrocarbyl-substituted norbornenes such as 5-butyl-2-norbornene; 5-hexyl-2-norbornene; 5-octyl-2-norbornene; 5-decyl-2-norbornene; 5-dodecyl-2-norbornene; 5-vinyl-2-norbornene; 5-ethylidene-2-norbornene; 5-isopropenyl-2-norbornene; 5-propenyl-2-norbornene; and 5-butenyl-2-norbornene, etc. More preferred cyclic olefins include dicyclopentadiene, tricyclopentadiene and higher oligomers of cyclopentadiene (such as cyclopentadiene tetramer, cyclopentadiene pentamer, etc.), tetracyclododecene, norbornene and C2-C 12 Hydrocarbyl-substituted norbornenes such as 5-butyl-2-norbornene, 5-hexyl-2-norbornene, 5-octyl-2-norbornene, 5-decyl-2-norbornene, 5-dodecyl-2-norbornene, 5-vinyl-2-norbornene, 5-ethylidene-2-norbornene, 5-isopropenyl-2-norbornene, 5-propenyl-2-norbornene, 5-butenyl-2-norbornene, etc.

[0022] The cyclic olefins can be used alone or mixed with each other in various combinations to adjust the properties of the olefin monomer composition. For example, a mixture of cyclopentadiene dimer and trimer provides a reduced melting point and produces a cured olefin copolymer with increased mechanical strength and stiffness relative to pure polyDCPD. As another example, the incorporation of norbornene or alkylnorbornene comonomers tends to produce a relatively soft and rubbery cured olefin copolymer.

[0023] In some embodiments, the cyclic olefin material comprises a mixture of DCPD monomers and cyclopentadiene oligomers. In some embodiments, based on the total amount of cyclic olefin monomers and oligomers, the mixture comprises at least 25 wt%, 30 wt%, 35 wt%, 40 wt% or 45 wt% DCPD. In some embodiments, based on the total amount of one or more cyclic olefin monomers and one or more oligomers, the mixture comprises no greater than 75 wt%, 70 wt%, 65 wt%, 60 wt%, 55 wt% or 50 wt% DCPD. In some embodiments, based on the total amount of cyclic olefin monomers and oligomers, the mixture comprises at least 15 wt%, 20 wt%, 25 wt%, 30 wt% or 35 wt% cyclic olefin oligomers, such as cyclopentadiene trimer and / or tetramer. In some embodiments, based on the total amount of cyclic olefin monomers and oligomers, the mixture comprises no greater than 60 wt%, 55 wt%, 50 wt%, 45 wt% or 40 wt% cyclic olefin oligomers, such as cyclopentadiene trimer and / or tetramer. In some embodiments, the mixture comprises at least 2 wt%, 3 wt%, 4 wt% or 5 wt% cyclic olefin oligomers having more than four cyclopentadiene repeat units, such as cyclopentadiene pentamer. In some embodiments, the mixture comprises no greater than 10 wt%, 9 wt%, 8 wt%, 7 wt%, 6 wt% or 5 wt% cyclic olefin oligomers having more than four cyclopentadiene repeat units, such as cyclopentadiene pentamer.

[0024] In some embodiments, in the absence of monoolefins or in combination with low concentrations of monoolefins, the cyclic olefin material comprises a mixture of DCPD monomers and cyclopentadiene oligomers. In this embodiment, based on the total amount of cyclic olefin monomers and oligomers, the amount of monoolefin is less than 25 wt%, 20 wt%, 15 wt%, 10 wt%, 9 wt%, 8 wt%, 7 wt%, 6 wt%, 5 wt%, 4 wt%, 3 wt%, 2 wt% or 1 wt%.

[0025] In other embodiments, based on the total amount of cyclic olefin monomers and oligomers, the mixture comprises at least 25 wt%, 30 wt%, 35 wt%, 40 wt% or 45 wt% of monoolefins, such as substituted norbornenes. In some embodiments, based on the total amount of one or more cyclic olefin monomers and one or more oligomers, the mixture comprises no more than 75 wt%, 70 wt%, 65 wt%, 60 wt%, 55 wt% or 50 wt% of monoolefins (e.g., C4-C12 (e.g., C8) alkyl norbornenes). In some embodiments, based on the total amount of cyclic olefin monomers and oligomers, the mixture comprises at least 15 wt%, 20 wt%, 25 wt%, 30 wt% or 35 wt% of cyclic olefin oligomers, such as cyclopentadiene trimers and / or tetramers. In some embodiments, based on the total amount of cyclic olefin monomers and oligomers, the mixture comprises no more than 60 wt%, 55 wt%, 50 wt%, 45 wt% or 40 wt% of cyclic olefin oligomers, such as cyclopentadiene trimers and / or tetramers. In some embodiments, the mixture comprises at least 2 wt%, 3 wt%, 4 wt% or 5 wt% of cyclic olefin oligomers having more than four cyclopentadiene repeat units, such as cyclopentadiene pentamers. In some embodiments, the mixture comprises no more than 10 wt%, 9 wt%, 8 wt%, 7 wt%, 6 wt% or 5 wt% of cyclic olefin oligomers having more than four cyclopentadiene repeat units, such as cyclopentadiene pentamers. In some embodiments, the mixture comprises no more than 5 wt%, 4 wt%, 3 wt%, 2 wt% or 1 wt% of DCPD monomers. In other embodiments, the mixture comprises no more than 25 wt% or 20 wt% of DCPD monomers.

[0026] The adhesive composition comprises at least 10 wt%, 11 wt%, 12 wt%, 14 wt% or 15 wt% of cyclic olefins (i.e., polyolefins and optionally monoolefins) based on the sum of the cyclic olefins and polymers. In some embodiments, the amount of cyclic olefins is at least 16 wt%, 17 wt%, 18 wt%, 19 wt% or 20 wt% of the sum of the cyclic olefins and polymers. In some embodiments, the amount of cyclic olefins is at least 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt% or 25 wt% of the sum of the cyclic olefins and polymers. The amount of cyclic olefins (i.e., polyolefins and optionally monoolefins) is generally no more than 80 wt% of the sum of the cyclic olefins and polymers. In some embodiments, the amount of cyclic olefins is no more than 75 wt%, 70 wt%, 55 wt%, 60 wt%, 55 wt% or 50 wt% of the sum of the cyclic olefins and polymers.

[0027] A variety of cyclic olefins are commercially available from Materia, Inc.

[0028] The adhesive composition described herein is prepared by the metathesis of cyclic olefins polymerized with a metal carbene catalyst. Group 8 transition metals, such as ruthenium and osmium, carbene compounds have been described as effective catalysts for ring-opening metathesis polymerization (ROMP). See, for example, US 10,239,965; which is incorporated herein by reference.

[0029] In a typical embodiment, the catalyst is a metal carbene olefin metathesis catalyst. Such catalysts generally have the following structure:

[0030]

[0031] where

[0032] M is a Group 8 transition metal;

[0033] L 1 、L 2 and L 3 are independently neutral electron donor ligands;

[0034] n is 0 or 1;

[0035] m is 0, 1 or 2;

[0036] k is 0 or 1;

[0037] X 1 and X 2 are independently anionic ligands;

[0038] and R 1 and R 2 are independently selected from hydrogen, hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl, substituted heteroatom-containing hydrocarbyl, and functional groups.

[0039] Typical metal carbene olefin metathesis catalysts contain Ru or Os as the Group 8 transition metal, with Ru being preferred.

[0040] The first group of metal carbene olefin metathesis catalysts are generally referred to as first-generation Grubbs-type catalysts and have the structure of catalyst formula (I). For the first group of metal carbene olefin metathesis catalysts, M is a Group 8 transition metal, m is 0, 1 or 2, and n, X 1 、X 2 、L 1 、L 2 and L 3 are as described below.

[0041] For the first group of metal carbene olefin metathesis catalysts, n is 0, and L 1 and L 2Independently selected from phosphine, sulfonated phosphine, phosphite, mono-oxophosphite, phosphonate, arsine, stibine, ether (including cyclic ether), amine, amide, imine, sulfoxide, carboxyl, nitroso, pyridine, substituted pyridine, imidazole, substituted imidazole, pyrazine, substituted pyrazine, and thioether. Exemplary ligands are trisubstituted phosphines. A typical trisubstituted phosphine has the formula PR H1 R H2 R H3 , where R H1 , R H2 and R H3 are each independently a substituted or unsubstituted aryl or C1-C10 alkyl group, especially a primary alkyl, secondary alkyl, or cycloalkyl group. In some embodiments, L 1 and L 2 are independently selected from the following: trimethylphosphine (PMe3), triethylphosphine (PEt3), tri-n-butylphosphine (PBu3), tris(o-tolyl)phosphine (P-o-tolyl3), tri-tert-butylphosphine (P-tert-Bu3), tricyclopentylphosphine (PCyclopentyl3), tricyclohexylphosphine (PCy3), triisopropylphosphine (P-i-Pr3), trioctylphosphine (POct3), triisobutylphosphine (P-i-Bu3), triphenylphosphine (PPh3), tris(pentafluorophenyl)phosphine (P(C6F5)3), methyldiphenylphosphine (PMePh2), dimethylphenylphosphine (PMe2Ph), and diethylphenylphosphine (PEt2Ph). Alternatively, L 1 and L 2 can be independently selected from bicyclic phosphates (e.g., monosubstituted 9-phosphabicyclo-[3.3.1]nonane or monosubstituted 9-phosphabicyclo[4.2.1]nonane], such as cyclohexylphosphine ligands, isopropylphosphine ligands, ethylphosphine ligands, methylphosphine ligands, butylphosphine ligands, pentylphosphine ligands, etc.

[0042] X 1 and X 2 are anionic ligands and can be the same or different, or linked together to form a cyclic group, usually although not necessarily a five- to eight-membered ring. In some embodiments, X 1 and X 2 are each independently hydrogen, halide, or one of the following groups: C1-C20 alkyl, C5-C24 aryl, C1-C20 alkoxy, C5-C24 aryloxy, C2-C20 alkoxycarbonyl, C6-C24 aryloxycarbonyl, C2-C24 acyl, C2-C24 acyloxy, C1-C20 alkylsulfonate, C5-C24 arylsulfonate, C1-C20 alkylthio, C5-C24 arylthio, C1-C20 alkylsulfinyl, NO3, -N=C=O, -N=C=S, or C5-C 24 arylsulfinyl. Optionally, X1 and X 2 may be substituted by one or more moieties selected from C1-C12 alkyl, C1-C12 alkoxy, C5-C24 aryl and halide, which (except for halide) may in turn be further substituted by one or more groups selected from halide, C1-C6 alkyl, C1-C6 alkoxy and phenyl. In some embodiments, X 1 and X 2 are halide, benzoate, C2-C6 acyl, C2-C6 alkoxycarbonyl, C1-C6 alkyl, phenoxy, C1-C6 alkoxy, C1-C6 alkylthio, aryl or C1-C6 alkylsulfonyl. In some preferred embodiments, X 1 and X 2 are each halide, CF3CO2, CH3CO2, CFH2CO2, (CH3)3CO, (CF3)2(CH3)CO, (CF3)(CH3)2CO, PhO, MeO, EtO, tosylate, mesylate or triflate. In some preferred embodiments, X 1 and X 2 are each chloride.

[0043] R 1 and R 2 are independently selected from hydrogen, hydrocarbon groups (e.g., C1-C20 alkyl, C2-C20 alkenyl, C2-C20 alkynyl, C5-C24 aryl, C6-C24 alkaryl, C6-C24 aralkyl, etc.), substituted hydrocarbon groups (e.g., substituted C1-C20 alkyl, C2-C20 alkenyl, C2-C20 alkynyl, C5-C24 aryl, C6-C24 alkaryl, C6-C24 aralkyl, etc.), heteroatom-containing hydrocarbon groups (e.g., heteroatom-containing C1-C20 alkyl, C2-C20 alkenyl, C2-C20 alkynyl, C5-C24 aryl, C6-C24 alkaryl, C6-C24 aralkyl, etc.) and substituted heteroatom-containing hydrocarbon groups (e.g., substituted heteroatom-containing C1-C20 alkyl, C2-C20 alkenyl, C2-C20 alkynyl, C5-C24 aryl, C6-C24 alkaryl, C6-C24 aralkyl, etc.) and functional groups. R 1 and R 2 may also be linked to form a cyclic group, which may be aliphatic or aromatic and may contain substituents and / or heteroatoms. Generally, such cyclic groups will contain from 4 to 12, preferably 5, 6, 7 or 8 ring atoms.

[0044] In some embodiments, R 1 is C1-C6 alkyl, C2-C6 alkenyl and C5-C14 aryl.

[0045] In some embodiments, R2 is phenyl, vinyl, methyl, isopropyl or tert-butyl, which is optionally substituted by one or more moieties selected from C1-C6 alkyl, C1-C6 alkoxy, phenyl and functional group Fn. Suitable functional groups (“Fn”) include phosphonate, phosphoryl, phosphinyl, phosphino, sulfonate, C1-C20 alkylthio, C5-C20 arylthio, C1-C20 alkylsulfonyl, C5-C20 arylsulfonyl, C1-C20 alkanesulfinyl, C5-C20 arylsulfinyl, sulfonamido, amino, acylamino, imino, nitro, nitroso, hydroxy, C1-C20 alkoxy, C5-C20 aryloxy, C2-C20 alkoxycarbonyl, C5-C20 aryloxycarbonyl, carboxyl, carboxylate, mercapto, formyl, C1-C20 thioester, cyano, cyanato, thiocyanato, isocyanate, thioisocyanate, carbamoyl, epoxy, styryl, silyl, silyloxy, silanyl, siloxazanyl, borate, oxoborate or halogen, or a metal-containing or metalloid-containing group (wherein the metal can be, for example, Sn or Ge).

[0046] In some embodiments, R 2 is phenyl or vinyl, which is substituted by one or more moieties selected from methyl, ethyl, chlorine, bromine, iodine, fluorine, nitro, dimethylamino, methyl, methoxy and phenyl. In some advantageous embodiments, R 2 is phenyl or -CH=C(CH3)2.

[0047] In some embodiments, one or both of R 1 and R 2 may have the structure -(W) n -U + V - , where W is selected from alkylene, substituted alkylene, heteroatom-containing alkylene or substituted heteroatom-containing alkylene; U is a positively charged Group 15 or Group 16 element substituted by hydrogen, hydrocarbon group, substituted hydrocarbon group, heteroatom-containing hydrocarbon group or substituted heteroatom-containing hydrocarbon group; V is a negatively charged counterion; and n is zero or 1. In addition, R 1 and R 2 may combine together to form an indenyl moiety, such as phenylindenyl.

[0048] In some embodiments, X 1 , X 2 , L 1 , L 2 , L 3 , R 1 and R 2Any one or more of them may be attached to a carrier, or two or more of said groups (e.g., three or four) may be bonded to each other to form one or more cyclic groups (including bidentate or multidentate ligands), as disclosed, for example, in U.S. Patent Application No. 5,312,940, which is incorporated herein by reference. When X 1 、X 2 、L 1 、L 2 、L 3 、R 1 and R 2 are connected to form a cyclic group, those cyclic groups may contain from 4 to 12, preferably 4, 5, 6, 7 or 8 atoms, or may comprise two or three such rings which may be fused or linked. The cyclic groups may be aliphatic or aromatic and may be heteroatom-containing and / or substituted. In some cases, the cyclic groups may form bidentate or tridentate ligands. Examples of bidentate ligands include, but are not limited to, diphosphines, diolates, alkyl diketonates and aryl diketonates.

[0049] Other metal carbene olefin metathesis catalysts (commonly referred to as second or third generation Grubbs-type catalysts) have a structure of catalyst formula (I), wherein L 1 is a carbene ligand having a structure of formula (II)

[0050]

[0051] wherein M, m, n, X 1 、X 2 、L 2 、L 3 、R 1 and R 2 are as defined in formula I previously;

[0052] X and Y are heteroatoms generally selected from N, O, S and P. Since O and S are divalent, when X is O or S, p must be zero; when Y is O or S, q must be zero; and k is zero or 1. However, when X is N or P, then p is 1, and when Y is N or P, then q is 1. In a preferred embodiment, both X and Y are N;

[0053] Q 1 、Q 2 、Q 3 and Q 4 are linkers, such as a hydrocarbon group (including substituted hydrocarbon groups, heteroatom-containing hydrocarbon groups and substituted heteroatom-containing hydrocarbon groups, such as substituted and / or heteroatom-containing alkyl groups) or -(CO)-, and w, x, y and z are independently zero or 1, which means that each linker is optional. Preferably, w, x, y and z are all zero. In addition, Q1 , Q 2 , Q 3 and Q 4 Two or more substituents on adjacent atoms within Q may be joined to form additional cyclic groups;

[0054] R 3 , R 3A , R 4 and R 4A are independently selected from hydrogen, a hydrocarbon group, a substituted hydrocarbon group, a heteroatom-containing hydrocarbon group, and a substituted heteroatom-containing hydrocarbon group. In addition, X and Y may independently be selected from one heteroatom of carbon and the above-described heteroatoms, and preferably no more than one of X or Y is carbon. Additionally, L 2 and L 3 may combine together to form a single bidentate electron-donating heterocyclic ligand. In addition, R 1 and R 2 may combine together to form an indenylidene moiety, preferably phenylindenylidene. In addition, X 1 , X 2 , L 2 , L 3 , X and Y may further coordinate with boron or carboxylate;

[0055] X 1 , X 2 , L 1 , L 2 , L 3 , R 1 , R 2 , R 3 , R 3A , R 4 , R 4A , Q 1 , Q 2 , Q 3 and Q 4 Any two or more of those may bond to each other to form one or more cyclic groups or may also be regarded as -A-Fn, where "A" is a divalent hydrocarbon moiety and Fn is a functional group as previously described. In addition, except for L 1 , such groups may bond to a support.

[0056] Such carbenes of a particular class are commonly referred to as N-heterocyclic carbene (NHC) ligands.

[0057] Thus, examples of N-heterocyclic carbene (NHC) ligands and acyclic diamino carbene ligands suitable as L1 include, but are not limited to, the following, where DIPP or DiPP is diisopropylphenyl and Mes is 2,4,6-trimethylphenyl:

[0058]

[0059]

[0060] Representative metathesis catalysts include, for example, benzylidene bis(tricyclohexylphosphine) ruthenium dichloride, dimethylvinylidene bis(tricyclohexylphosphine) ruthenium dichloride, dimethylvinylidene bis(tricyclopentylphosphine) ruthenium dichloride, benzylidene (tricyclohexylphosphine) (1,3 - bis(trimethylphenyl)-4,5 - dihydroimidazol - 2 - ylidene) ruthenium dichloride, dimethylvinylidene (tricyclopentylphosphine) (1,3 - bis(trimethylphenyl)-4,5 - dihydroimidazol - 2 - ylidene) ruthenium dichloride, dimethylvinylidene (tricyclohexylphosphine) (1,3 - bis(trimethylphenyl)-4,5 - dihydroimidazol - 2 - ylidene) ruthenium dichloride, benzylidene (tricyclohexylphosphine) (1,3 - bis(trimethylphenyl)imidazol - 2 - ylidene) ruthenium dichloride, dimethylvinylidene (tricyclopentylphosphine) (1,3 - bis(trimethylphenyl)imidazol - 2 - ylidene) ruthenium dichloride, and dimethylvinylidene (tricyclohexylphosphine) (1,3 - bis(trimethylphenyl)imidazol - 2 - ylidene) ruthenium dichloride.

[0061] A variety of metathesis catalysts are known, such as those described in the previously cited US 10,239,965.

[0062] In some embodiments, the adhesive compositions described herein are two - component compositions, in which the catalyst is separated from the cyclic olefin prior to the time of use. In this embodiment, any suitable ring - opening metathesis polymerization catalyst can be utilized.

[0063] In other embodiments, the adhesive compositions of the tape and the one - component adhesive compositions contain latent ring - opening metathesis polymerization catalysts. Latent ring - opening metathesis polymerization catalysts exhibit little or no catalytic activity (e.g., polymerization of cyclic olefins) at room temperature for at least 24 hours. Referring to the existing exemplary adhesive compositions and articles, the catalyst or its precatalyst has sufficient latency such that after at least 24 hours at 25 °C, the adhesive composition exhibits a lap - shear value with aluminum of less than 30 kPa. The adhesive or the adhesive - coated article can be stored at low temperature to prevent premature activation of the thermally activated catalyst. Similarly, the adhesive or the adhesive - coated article can be stored in a dark box or in dark packaging materials to prevent premature activation of the photoactivated catalyst.

[0064] Latent ring-opening metathesis polymerization catalysts can be triggered, or in other words, activated, using heat (i.e., thermal activation), actinic (e.g., ultraviolet) radiation, compounds, or combinations thereof. In some embodiments, latent ring-opening metathesis polymerization catalysts are activated by a combination of actinic (e.g., ultraviolet) radiation and an acid compound. In some embodiments, modified first- or second-generation Grubbs-type catalysts as previously described can be used as latent catalysts. A representative latent catalyst is depicted below:

[0065]

[0066] Such catalysts can be activated with an acid (such as a photoacid generator (“PAG”)), as depicted in the following reaction scheme:

[0067]

[0068] Another class of latent catalysts includes carbynes, i.e., (e.g., Ru) metal-carbon triple bonds (also described in the literature as (e.g., Ru) metal carbides). These catalysts can be characterized as ring-opening metathesis polymerization precatalysts because such catalysts form ring-opening metathesis polymerization catalysts when reacted with an acid (such as a photoacid generator), as depicted in the following representative reaction scheme:

[0069]

[0070] Such ring-opening metathesis polymerization precatalysts can have the general formula:

[0071]

[0072] where L 1 is a carbene ligand having the structure of formula (II)

[0073]

[0074] where M, X 1 X 2 and L 2 are as defined previously for formula I. In some embodiments, X 1 and X 2 are chlorine. In some embodiments, L 2 is PCy3.

[0075] In other embodiments, latent catalysts can be activated by actinic (e.g., UV) energy in the absence of an acid compound. A class of compounds can be characterized as Fischer-type ruthenium carbene catalysts, such as those described in WO2018 / 045132; this document is incorporated herein by reference. Such catalysts have the following formula or geometric isomers thereof

[0076]

[0077] Wherein X 1 and X 2 are each independently an anionic ligand;

[0078] Y is 0, N-R 1 or S; and

[0079] Q is a two-atom bond having the structure -CR 11 -R 12 -CR 13 R 14 - or -C 11 =CR 13 -; wherein, R 11 、R 12 、R 13 and R 14 are each independently hydrogen, a hydrocarbyl group or a substituted hydrocarbyl group;

[0080] R 1 and R 2 are each independently hydrogen, an optionally substituted hydrocarbyl group or may be joined together to form an optionally substituted cyclic aliphatic group;

[0081] R 3 and R 4 are each independently an optionally substituted hydrocarbyl group, and

[0082] R 5 、R 6 are each independently H, C1-24 alkyl, C1-24 alkoxy, C1-24 fluoroalkyl, C1-24 fluoroalkoxy, C1-24 alkylhydroxy, C1-24 alkoxyhydroxy, C1-24 fluoroalkylhydroxy (including perfluoroalkylhydroxy), C1-24 fluoroalkoxyhydroxy, halogen, cyano, nitro or hydroxy; and

[0083] m and n are each independently 1, 2, 3 or 4.

[0084] In some embodiments, this moiety

[0085]

[0086] is an N-heterocyclic carbene (NHC) ligand as described above. Other N-heterocyclic carbene (NHC) ligands include:

[0087]

[0088] In one embodiment, the metathesis catalyst comprises a compound having the following structure:

[0089]

[0090] The photocatalytically activated catalyst can be preferably used for bonding heat-sensitive substrates made of organic polymer materials. However, for bonding other substrates, a latent catalyst can be thermally activated. In a typical embodiment, the thermal activation temperature is much higher than room temperature. For example, the thermal activation temperature is at least 50 °C, 60 °C, 70 °C, 80 °C, 90 °C or 100 °C. The thermal activation temperature can range up to 130 °C, 140 °C or 150 °C. In one embodiment, the thermally latent catalyst includes an isomer that is deactivated at room temperature but is active at temperatures in the range of 50 °C to 90 °C. A representative catalyst is as follows:

[0091]

[0092] Another class of thermally activatable catalysts contains chelating alkylene ligands. Some representative catalysts include:

[0093]

[0094] Based on the total weight of the composition, the composition generally contains a metathesis catalyst in an amount in the range of about 0.0001 wt% to 2 wt%. In some embodiments, the composition generally contains at least 0.0005 wt%, 0.001 wt%, 0.005 wt%, 0.01 wt%, 0.05 wt%, 0.10 wt%, 0.15 wt% or 0.20 wt% of the catalyst. In some embodiments, the composition generally contains no more than 1.5 wt%, 1 wt% or 0.5 wt% of the catalyst.

[0095] In some embodiments, the activation of the latent olefin metathesis catalyst is achieved by adding an acid, a photoacid generator ("PAG") or a thermal acid generator ("TAG") and exposing the composition to (e.g., ultraviolet) photocatalytic radiation. When present, the acid, photoacid or thermal acid generator is typically present in the adhesive composition in an amount of at least 0.005 wt% or 0.01 wt% of the composition, and generally no more than 10 wt% of the composition. In some embodiments, the concentration is no more than 5 wt%, 4 wt%, 3 wt%, 2 wt%, 1 wt% or 0.5 wt% of the adhesive composition. Alternatively, the acid, photoacid generator ("PAG") or thermal acid generator ("TAG") can be applied to the substrate to which the adhesive is applied.

[0096] Upon irradiation with light energy, the ionic photoacid generator undergoes a cleavage reaction and releases one or more Lewis or Bronsted acid molecules that activate the olefin metathesis catalyst. The photoacid generators available are thermally stable and do not undergo thermally induced reactions with the copolymer and are readily soluble or dispersible in the composition. Typical photoacid generators are those in which the initial acid has a pKa value of ≤0. Photoacid generators are known and reference may be made to Chemistry and Technology of UV and EB Formulation for Coatings, Inks and Paints, vol. III by K. Dietliker (Chemistry and Technology of UV and EB Formulation for Coatings, Inks and Paints, vol. III), SITA Technology Ltd., London, 1991. Reference may also be made to the Kirk-Othmer Encyclopedia of Chemical Technology, 4 th Edition, Supplement Volume, John Wiley and Sons, New York, year, pp 253-255).

[0097] Cations that can be used as the cationic moiety of the ionic photoinitiator of the present invention include organic onium cations, such as those described in U.S. Patent Nos. 4,250,311, 3,708,296, 4,069,055, 4,216,288, 5,084,586, 5,124,417, 5,554,664, and such descriptions are incorporated herein by reference, including onium salts centered on aliphatic or aromatic groups of IVA - VIIA (CAS version), preferably onium salts centered on I-, S-, P-, Se-, N-, and C-, such as those selected from sulfoxonium, iodonium, sulfonium, selenonium, pyridinium, carbonium, and phosphonium salts, and most preferably onium salts centered on I- and S-, such as those selected from sulfoxonium, diaryliodonium, triarylsulfonium, diarylalkylsulfonium, dialkylarylsulfonium, and trialkylsulfonium salts, where "aryl" and "alkyl" are as defined and have up to four independently selected substituents. Substituents on the aryl and alkyl moieties preferably will have fewer than 30 carbon atoms and up to 10 heteroatoms selected from N, S, non - peroxidic O, P, As, Si, Sn, B, Ge, Te, Se. Examples include hydrocarbyl groups such as methyl, ethyl, butyl, dodecyl, tetracosyl, benzyl, allyl, benzylidene, vinyl, and ethynyl; hydrocarbyloxy groups such as methoxy, butoxy, and phenoxy; hydrocarbylthio groups such as methylthio and phenylthio; hydrocarbyloxycarbonyl groups such as methoxycarbonyl and phenoxycarbonyl; hydrocarbylcarbonyl groups such as formyl, acetyl, and benzoyl; hydrocarbylcarbonyloxy groups such as acetoxy and cyclohexylcarbonyloxy; hydrocarbylamide groups such as acetamido and benzamido; azo; oxoboron; halogen groups such as chlorine, bromine, iodine, and fluorine; hydroxy; oxy; diphenylarsino; diphenylstibino; trimethylgermyl; trimethylsiloxy; and aromatic groups such as cyclopentadienyl, phenyl, tolyl, naphthyl, and indenyl. For sulfonium salts, the substituents can be further substituted by dialkyl or diarylsulfonium cations; an example thereof is 1,4 - phenylene bis(diphenylsulfonium).

[0098] Useful onium salt photoacid generators include diazonium salts such as aryl diazonium salts; halonium salts such as diaryliodonium salts; sulfonium salts such as triarylsulfonium salts such as triphenylsulfonium trifluoromethanesulfonate; selenonium salts such as triarylselenonium salts; sulfoxonium salts such as triarylsulfoxonium salts; and other miscellaneous onium salts such as triarylphosphonium and arsonium salts, as well as pyranylium and thiopyranylium salts.

[0099] Ionic photoacid generators include, for example, bis(4 - tert - butylphenyl)iodonium hexafluoroantimonate (FP5034 from Hampford Research Inc., Stratford, CT, USA) TM )、as Syna PI - 6976TM A mixture of triarylsulfonium salts (diphenyl(4-phenylthio)phenylsulfonium hexafluoroantimonate, bis(4-(diphenylsulfonium)phenyl)sulfide hexafluoroantimonate), (4-methoxyphenyl)phenyl iodonium trifluoromethanesulfonate, bis(4-tert-butylphenyl)camphorsulfonic acid iodonium salt, bis(4-tert-butylphenyl)iodonium hexafluoroantimonate, bis(4-tert-butylphenyl)iodonium hexafluorophosphate, bis(4-tert-butylphenyl)iodonium tetraphenylborate, bis(4-tert-butylphenyl)iodonium tosylate, bis(4-tert-butylphenyl)iodonium trifluoromethanesulfonate, ([4-(octyloxy)phenyl]phenyl iodonium hexafluorophosphate), ([4-(octyloxy)phenyl]phenyl iodonium hexafluoroantimonate), (4-isopropylphenyl)(4-methylphenyl)iodonium tetrakis(pentafluorophenyl)borate (as Rhodorsil 2074 TM Purchased from Bluestar Silicones, East Brunswick, NJ, USA), bis(4-methylphenyl)iodonium hexafluorophosphate (as Omnicat 440 TM Purchased from IGM Resins, Bartlett, IL, USA), 4-(2-hydroxy-1-tetradecyloxy)phenyl]phenyl iodonium hexafluoroantimonate, triphenylsulfonium hexafluoroantimonate (as CT-548 TM Purchased from Chitec Technology Corp., Taipei, Taiwan, China), diphenyl(4-phenylthio)phenylsulfonium hexafluorophosphate, bis(4-(diphenylsulfonium)phenyl)sulfide bis(hexafluorophosphate), diphenyl(4-phenylthio)phenylsulfonium hexafluoroantimonate, bis(4-(diphenylsulfonium)phenyl)sulfide hexafluoroantimonate and can be traded under the names Syna PI-6992 TM and Syna PI-6976 TM These blends of triarylsulfonium salts purchased from Synasia, Metuchen, NJ, USA (for PF6 and SbF6 salts respectively).

[0100] In one embodiment, the photoacid generator is a triazine compound having the following formula:

[0101]

[0102] Wherein R1, R 2 , R3 and R4 of the triazine crosslinker are independently hydrogen or alkoxy groups, and R1, R 2, one to three of R3 and R4 are hydrogen. The alkoxy group typically has no more than 12 carbon atoms. In a preferred embodiment, the alkoxy group is independently methoxy or ethoxy. A representative substance is 2,4,-bis(trichloromethyl)-6-(3,4-bis(methoxy)phenyl)-triazine. Such triazine compounds are further described in U.S. Patent 4,330,590.

[0103] Optionally, the composition may include a photosensitizer or a photoaccelerator having a photoacid generator. The use of a photosensitizer or a photoaccelerator changes the wavelength sensitivity of the radiation-sensitive composition using the latent catalyst and photoacid generator of the present invention. The use of a photosensitizer or a photoaccelerator is particularly advantageous when the photoacid generator does not strongly absorb the incident radiation. The use of a photosensitizer or a photoaccelerator increases the radiation sensitivity, thereby allowing for a shorter exposure time and / or the use of a lower power radiation source.

[0104] Upon contact with thermal energy, the TAG undergoes a cleavage reaction and releases one or more Lewis or Bronsted acid molecules. The available TAGs are thermally stable up to the activation temperature. Preferred TAGs are those in which the pK of the initial acid a value is less than or equal to 0. The activation temperature of the available thermal acid generators is 150 °C or lower, preferably 140 °C or lower. As used herein, the "activation temperature" is the temperature at which the thermal release of the initial acid occurs through the TAG in the binder formulation. Generally, the activation temperature of the TAG will be in the range of about 50 °C to about 150 °C.

[0105] Available types of TAGs may include, for example, alkylammonium salts of sulfonic acids, such as triethylammonium p-toluenesulfonate (TEAPTS). Another suitable type of TAG is the TAG disclosed in U.S. Patent 6,627,384 (Kim et al.); this patent is incorporated herein by reference and describes a cyclic alcohol having adjacent sulfonate leaving groups. Suitable types of thermal acid generators also include those described in U.S. Patents 7,514,202 (Ohsawa et al.) and 5,976,690 (Williams et al.); this literature is incorporated herein by reference.

[0106] Suitable ROMP catalysts or precatalysts can polymerize cyclic olefins via thermal curing, exposure to actinic (e.g., UV) radiation, or a combination thereof.

[0107] The composition may also optionally contain a rate regulator, such as triphenylphosphine (TPP), tricyclopentylphosphine, tricyclohexylphosphine, triisopropylphosphine, trialkyl phosphite, triaryl phosphite, mixed phosphites, pyridine, or other Lewis bases. The rate regulator can be added to the cycloolefin component to delay or accelerate the polymerization rate as needed. The amount of the rate regulator can be the same as the amount of the catalyst described above. Generally, based on the total amount of the cycloolefin, the amount of the rate regulator is less than 0.01 wt% or 0.005 wt%.

[0108] The adhesive composition further comprises a polymer.

[0109] The amount of the polymer is generally at least 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt% or 50 wt% of the sum of the cycloolefin and the polymer. In some embodiments, the amount of the polymer is at least 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt% or 80 wt% of the sum of the cycloolefin and the polymer. In some embodiments, the amount of the polymer is not greater than 80 wt%, 75 wt%, 70 wt%, 65 wt%, 60 wt%, 55 wt% or 50 wt% of the sum of the cycloolefin and the polymer.

[0110] In some embodiments, the glass transition temperature of the polymer (e.g., a pressure-sensitive adhesive) is below 25 °C, as determined by dynamic mechanical analysis (according to the test method described in the examples). The Tg of the polymer or copolymer can be estimated using the Fox equation based on the Tg of the homopolymers of the constituent monomers and their weight percentages.

[0111] A higher concentration of a low-Tg polymer (e.g., a pressure-sensitive adhesive) can be suitable for providing a higher initial adhesion to the substrate before polymerizing the cycloolefin. However, a higher concentration of the cycloolefin is suitable for a higher structural bond strength, as evidenced by a high lap shear value.

[0112] In some embodiments, the polymer together with the unpolymerized cycloolefin is substantially solid, such that an adhesive article, such as a tape, can be formed from the composition.

[0113] In some embodiments, the polymer is a (meth)acrylic polymer that includes polymerization units derived from one or more (meth)acrylate monomers, which are derived from an alcohol having 1 to 14 carbon atoms and preferably an average of 4 to 12 carbon atoms (e.g., non-tertiary). The (meth)acrylic polymer and / or PSA composition may also include one or more monomers (e.g., common to acrylic polymers and adhesives), such as (meth)acrylate monomers (also referred to as (meth)acrylate monomers and (meth)acrylic alkyl ester monomers) optionally combined with one or more other monomers, such as acid-functional ethylenically unsaturated monomers, non-acid-functional polar monomers, and vinyl monomers.

[0114] Examples of monomers include esters of acrylic or methacrylic acid with non-tertiary alcohols such as ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 1-hexanol, 2-hexanol, 2-methyl-1-pentanol, 3-methyl-1-pentanol, 2-ethyl-1-butanol, 3,5,5-trimethyl-1-hexanol, 3-heptanol, 1-octanol, 2-octanol, isooctanol, 2-ethyl-1-hexanol, 1-decanol, 2-propylheptanol, 1-dodecanol, 1-tridecanol, 1-tetradecanol, and the like. In some embodiments, a preferred (meth)acrylate monomer is an ester of (meth)acrylic acid with isooctyl alcohol.

[0115] The (meth)acrylic polymer includes one or more low Tg monomers that, when polymerized (i.e., independently) to form a homopolymer, have a Tg of no greater than 10 °C. In some embodiments, when the low Tg monomers react to form a homopolymer, these monomers have a Tg of no greater than 0 °C, no greater than -5 °C, or no greater than -10 °C. The Tg of these homopolymers is typically greater than or equal to -80 °C, greater than or equal to -70 °C, greater than or equal to -60 °C, or greater than or equal to -50 °C. The Tg of these homopolymers can be, for example, in the range of -80 °C to 20 °C, -70 °C to 10 °C, -60 °C to 0 °C, or -60 °C to -10 °C.

[0116] The low Tg monomers can have the formula

[0117] H2C=CR1C(O)OR 8

[0118] where R 1 is H or methyl, and R 8 is an alkyl having 1 to 22 carbons or a heteroalkyl having 2 to 20 carbons and 1 to 6 heteroatoms selected from oxygen or sulfur. The alkyl or heteroalkyl group can be straight-chain, branched-chain, cyclic, or a combination thereof.

[0119] Exemplary low Tg monomers include, for example, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, n-pentyl acrylate, isopentyl acrylate, n-hexyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 4-methyl-2-pentyl acrylate, n-octyl acrylate, 2-octyl acrylate, isooctyl acrylate, isononyl acrylate, decyl acrylate, isodecyl acrylate, lauryl acrylate, isotridecyl acrylate, stearyl acrylate, and dodecyl acrylate.

[0120] Low Tg heteroalkyl acrylate monomers include, for example, 2-methoxyethyl acrylate and 2-ethoxyethyl acrylate.

[0121] In some embodiments, the (meth)acrylic polymer comprises at least one low Tg monomer having an acyclic (meth)acrylic alkyl ester monomer containing 4 to 20 carbon atoms. In some embodiments, the (meth)acrylic polymer and / or PSA comprises at least one low Tg monomer having an (e.g., branched) alkyl group containing 6 to 20 carbon atoms. In some embodiments, the low Tg monomer has an (e.g., branched) alkyl group containing 7 or 8 carbon atoms. Exemplary monomers include, but are not limited to, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, 2-octyl (meth)acrylate, isodecyl (meth)acrylate, and lauryl (meth)acrylate.

[0122] In some embodiments, the (meth)acrylic polymer comprises a high Tg monomer having a Tg greater than 10 °C and typically at least 15 °C, 20 °C, or 25 °C and preferably at least 50 °C. Suitable high Tg (meth)acrylic alkyl ester monomers include, for example, tert-butyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, stearyl methacrylate, phenyl methacrylate, cyclohexyl methacrylate, isobornyl acrylate, isobornyl methacrylate (110 °C according to Aldrich), (meth)acrylic norbornene, benzyl methacrylate, 3,3,5-trimethylcyclohexyl acrylate, cyclohexyl acrylate, N-octylacrylamide, and propyl methacrylate or combinations.

[0123] The polymerized (meth)acrylic alkyl ester monomer is typically present in the (meth)acrylic polymer in an amount of at least 50 wt%, 55 wt%, 60 wt%, 65 wt%, or 75 wt% of the (meth)acrylic polymer.

[0124] In some embodiments, the (meth)acrylic polymer comprises at least 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, 85 wt%, 90 wt% or 95 wt% or more of polymerized units of a low Tg (meth)acrylate (e.g., an alkyl (meth)acrylate) monomer. When a high Tg monomer is present, the amount can be at least 5 wt%, 10 wt%, 15 wt% or 20 wt%, up to a range of 30 wt% of the polymerized units of the (meth)acrylic polymer.

[0125] (Meth)acrylic polymers can optionally include acidic functional monomers (a subgroup of high Tg monomers), where the acidic functional group can be the acid itself, such as a carboxylic acid, or a portion can be its salt, such as an alkali metal carboxylate. Acid functional monomers that can be used include, but are not limited to, those selected from the group consisting of ethylenically unsaturated carboxylic acids, ethylenically unsaturated sulfonic acids, ethylenically unsaturated phosphonic acids, and mixtures thereof. Examples of such compounds include those selected from acrylic acid, methacrylic acid, itaconic acid, fumaric acid, crotonic acid, citraconic acid, maleic acid, oleic acid, β-carboxyethyl (meth)acrylate, 2-sulfoethyl methacrylate, styrenesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, vinylphosphonic acid, and mixtures thereof.

[0126] Due to their availability, acid functional monomers are typically selected from ethylenically unsaturated carboxylic acids, i.e., (meth)acrylic acid. When an even stronger acid is desired, acidic monomers include ethylenically unsaturated sulfonic acids and ethylenically unsaturated phosphonic acids. Based on the total weight of the polymerized units of the (meth)acrylic polymer, acid functional monomers can be present in an amount of 0 wt% or at least 0.5 wt% and no greater than 5 wt%, 10 wt% or 15 wt%. In some embodiments, such as when the catalyst can be activated with an acid, the (meth)acrylic polymer of the one-component adhesive composition or adhesive article can contain little or no polymerized acid functional monomer. In this embodiment, the amount of polymerized acid functional monomer is generally no greater than 5 wt%, 4 wt%, 3 wt%, 2 wt%, 1 wt%, 0.5 wt% or 0.1 wt% of the (meth)acrylic polymer.

[0127] (Meth)acrylic polymers and / or PSA compositions can optionally include other monomers, such as non-acid functional polar monomers.

[0128] Representative examples of suitable polar monomers include, but are not limited to, 2-hydroxyethyl (meth)acrylate; tetrahydrofurfuryl acrylate; N-vinylpyrrolidone; N-vinylcaprolactam; acrylamide; mono- or di-N-alkyl substituted acrylamides; tert-butylacrylamide; dimethylaminoethyl acrylamide; N-octylacrylamide; poly(alkoxyalkyl) (meth)acrylates, which include 2-(2-ethoxyethoxy)ethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-methoxyethoxyethyl (meth)acrylate, 2-methoxyethyl methacrylate, polyethylene glycol mono(meth)acrylate; alkyl vinyl ethers, including vinyl methyl ether; and mixtures thereof. In some embodiments, the (meth)acrylic polymer comprises hydroxyl, ether or amide groups. The non-acid functional polar monomers may be present in an amount of zero or at least 0.5 wt%, 1 wt%, 2 wt%, 3 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt% or 10 wt% of the polymerized units of the (meth)acrylic polymer, up to a maximum of 15 wt% or 20 wt%.

[0129] When the (meth)acrylic polymer comprises polymerized units of an acid functional monomer or a non-acid functional polar monomer, the (meth)acrylic polymer can be used as an adhesion promoter.

[0130] When used, vinyl monomers useful in (meth)acrylate polymers include vinyl esters (e.g., vinyl acetate and vinyl propionate), styrene, substituted styrenes (e.g., α-methylstyrene), vinyl halides, and mixtures thereof. As used herein, vinyl monomers do not include acid functional monomers, acrylate monomers, and polar monomers. Based on the total polymerized units of the (meth)acrylic polymer, the vinyl monomers may be present in an amount of 0 wt% or at least 0.5 wt% or 1 wt%, up to a maximum of 5 wt%.

[0131] (Meth)acrylic polymers and / or compositions may optionally contain a crosslinking agent. When used, the amount of the crosslinking agent is typically present in an amount of at least 0.05 parts by weight, 0.10 parts by weight, 0.15 parts by weight, 0.20 parts by weight, up to 1 part by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight or 5 parts by weight, relative to 100 parts by weight of the composition.

[0132] In some embodiments, the (meth)acrylic polymer and / or composition comprises a polyfunctional (meth)acrylate crosslinking monomer. Examples of polyfunctional (meth)acrylates that can be used include, but are not limited to, di(meth)acrylates, tri(meth)acrylates, and tetra(meth)acrylates, such as 1,6 - hexanediol di(meth)acrylate, poly(ethylene glycol) di(meth)acrylate, polybutadiene di(meth)acrylate, polyurethane di(meth)acrylate, and propoxylated glycerol tri(meth)acrylate, and mixtures thereof.

[0133] In other embodiments, the (meth)acrylic polymer and / or composition comprises a chlorotriazine crosslinking compound. The previously described chlorotriazine compounds can be used as photoacid generators and crosslinking compounds.

[0134] (Meth)acrylic copolymers can be polymerized by a variety of techniques, which include, but are not limited to, solution polymerization, dispersion polymerization, solvent - free bulk polymerization, and radiation polymerization (including processes using ultraviolet light, electron beam, and γ - radiation). The monomer mixture can contain a polymerization initiator, especially of the thermal initiator or photoinitiator type, and in an amount effective to polymerize the comonomers.

[0135] A typical solution polymerization method is carried out as follows: monomers, a suitable solvent, and an optional chain transfer agent are added to a reaction vessel, a radical initiator is added, the vessel is purged with nitrogen, and the reaction vessel is maintained at an elevated temperature (e.g., about 40 °C to 100 °C) until the reaction is complete, typically for about 1 to 20 hours depending on the batch size and temperature. Examples of typical solvents include methanol, tetrahydrofuran, ethanol, isopropanol, acetone, methyl ethyl ketone, methyl acetate, ethyl acetate, toluene, xylene, and ethylene glycol alkyl ethers. These solvents can be used alone or as mixtures thereof.

[0136] Available initiators include those that generate free radicals upon exposure to heat or light to initiate the (co)polymerization of the monomer mixture. The initiator is typically used in a concentration range of about 0.0001 to about 3.0 parts by weight, preferably about 0.001 to about 1.0 parts by weight, and still more preferably about 0.005 to about 0.5 parts by weight based on the total monomers or polymer units.

[0137] Suitable initiators include, but are not limited to, those selected from the group consisting of azo compounds (such as VAZO 64 (2,2'-azobis(isobutyronitrile)), VAZO 52 (2,2'-azobis(2,4-dimethylpentanenitrile)), and VAZO 67 (2,2'-azobis(2-methylbutyronitrile)) commercially available from E.I. du Pont de Nemours Co.), peroxides (such as benzoyl peroxide and lauroyl peroxide), and mixtures thereof. A preferred oil-soluble thermal initiator is (2,2'-azobis(2-methylbutyronitrile)). When an initiator is used, based on 100 parts by weight of the monomer component in the pressure-sensitive adhesive, the initiator may be present in an amount of about 0.05 to about 1 part by weight, preferably about 0.1 to about 0.5 part by weight.

[0138] A method of preparing a (meth)acrylic polymer comprises partially polymerizing monomers to produce a slurry composition comprising a solute (meth)acrylic polymer and one or more unpolymerized solvent monomers. The unpolymerized solvent monomers generally comprise the same monomers as those used to produce the solute (meth)acrylic polymer. If some of the monomers are consumed during the polymerization of the (meth)acrylic polymer, then the one or more unpolymerized solvent monomers comprise at least some of the same one or more monomers as those used to produce the solute (meth)acrylic polymer. Additionally, once the (meth)acrylic polymer has been formed, one or more of the same monomers or one or more other monomers may be added to the slurry. The partial polymerization provides a coatable solution of the (meth)acrylic solute polymer in one or more free-radically polymerizable solvent monomers. The partially polymerized composition is then coated on a suitable substrate and further polymerized.

[0139] The slurry process offers advantages over solvent or solution polymerization processes; the slurry process produces higher molecular weight materials. These higher molecular weights increase the amount of chain entanglement, thereby increasing the cohesive strength. Also, the distance between crosslinks can be greater with the high molecular weight slurry polymer, which results in increased wetness on the surface. The polymerization of (meth)acrylics is generally carried out in the absence of water or organic solvents such as ethyl acetate, toluene, and tetrahydrofuran, which do not react with the comonomers of the (meth)acrylic polymer.

[0140] The polymerization of the (meth)acrylate solvent monomers can be achieved by contacting the slurry composition with (e.g., UV) energy in the presence of a photoinitiator. In cases where, for example, ionizing radiation is used to initiate the polymerization, an energy-activated initiator may not be required. Generally, the photoinitiator may be used at a concentration of at least 0.0001 part by weight, preferably at least 0.001 part by weight, more preferably at least 0.005 part by weight, relative to 100 parts by weight of the slurry.

[0141] Useful photoinitiators include benzoin ethers such as benzoin methyl ether and benzoin isopropyl ether; substituted acetophenones such as the 2,2-dimethoxy-2-phenylacetophenone photoinitiator available under the trade names IRGACURE 651 or ESACURE KB-1 photoinitiator (Sartomer Co., West Chester, PA), and dimethylhydroxyacetophenone; substituted α-ketols such as 2-methyl-2-hydroxypropiophenone; aromatic sulfonyl chlorides such as 2-naphthalene-sulfonyl chloride; and photosensitive oximes such as 1-phenyl-1,2-propanedione-2-(O-ethoxy-carbonyl)oxime. Particularly preferred among these photoinitiators are substituted acetophenones.

[0142] Preferred photoinitiators are photoactive compounds that undergo Norrish I cleavage to generate free radicals, which can initiate by addition to the double bonds of acrylates. The photoinitiator can be added to the mixture to be coated after the polymer has been formed, i.e., the photoinitiator can be added to the slurry composition. Such polymerizable photoinitiators are described, for example, in U.S. Pat. Nos. 5,902,836 and 5,506,279 (Gaddam et al.).

[0143] Relative to 100 parts by weight of the total slurry content, this photoinitiator is preferably present in an amount of 0.1 to 1.0 parts by weight.

[0144] The composition optionally further comprises an adhesion promoter.

[0145] In some embodiments, the adhesion promoter is a compound or polymer containing at least two isocyanate groups. The adhesion promoter can be a diisocyanate, a triisocyanate, or a polyisocyanate (i.e., containing four or more isocyanate groups). The adhesion promoter can be a mixture of at least one diisocyanate, triisocyanate, or polyisocyanate. In some embodiments, the adhesion promoter is a diisocyanate compound or a mixture of diisocyanate compounds.

[0146] In some embodiments, the adhesion promoter is a polymeric polyisocyanate (e.g., a diisocyanate) such as a polyisocyanate prepolymer available from Convestro, including the trade names DESMODUR E-28 (based on MDI) and Baytec ME-230 (modified MDI based on polytetramethylene ether glycol (PTMEG)). Such polymeric polyisocyanates (e.g., diisocyanates) contain C2-C4 alkyleneoxy repeating units. In addition, the average equivalent weight of such polymeric polyisocyanates is typically in the range of 200 g / mol / isocyanate group to 5000 g / mol / isocyanate group.

[0147] In some embodiments, the polymeric isocyanate adhesion promoter is generally the reaction product of a polyol and an aliphatic diisocyanate, such as MDI. The polyol generally has one or more oxygen atoms in the main chain, such as in the case of polytetramethylene ether glycol and polypropylene oxide.

[0148] In some embodiments, the molecular weight of the polyol (e.g., polytetramethylene ether glycol) is about 90 g / mol. The NCO content of such polymeric isocyanates can be greater than 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt% or 20 wt%. The NCO content is generally not greater than 25 wt%.

[0149] In some embodiments, the molecular weight of the polyol (e.g., polypropylene oxide) is at least 1000 g / mol, 1100 g / mol, 1200 g / mol, 1300 g / mol, 1400 g / mol, 1500 g / mol, 1600 g / mol, 1700 g / mol, 1800 g / mol, 1900 g / mol or 2000 g / mol. The amount of the polymeric polyol is generally less than 55 wt%, 50 wt%, 45 wt% or 40 wt% of the polymeric isocyanate. The NCO content of such polymeric isocyanates can be greater than 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt% or 15 wt%. The NCO content is generally not greater than 20 wt%. The equivalent weight of the polymeric polyol can be less than 400 g / mol / NCO group, 350 g / mol / NCO group or 300 g / mol / NCO group. The equivalent weight is generally at least 150 g / mol / NCO group, 200 g / mol / NCO group or 250 g / mol / NCO group.

[0150] In some embodiments, the composition can include a maleic anhydride grafted polymer as an adhesion promoter, such as those available under the trade name "POLYVEST MA 75" from Evonik, Essen, Germany, and those available under the trade name "RICON 131 maleated polybutadiene 131MA10" from Cray Valley, Exton, PA. In this embodiment, the polymer can be characterized as a polyolefin. The polyolefin can be unsaturated and contain an olefin moiety, such as polybutadiene. Different from styrene block copolymers, olefin polymers lack polystyrene blocks.

[0151] In some embodiments, the average anhydride equivalent of the polyolefin adhesion promoter ranges from 200 g / mol / anhydride group to 5000 g / mol / anhydride group. In some embodiments, the average anhydride equivalent ranges from no greater than 4000 g / mol / anhydride group, 3000 g / mol / anhydride group, 2000 g / mol / anhydride group, 1000 g / mol / anhydride group g / mol / anhydride group.

[0152] (e.g., a polymeric polyisocyanate or an olefin polymer containing maleic anhydride moieties) The adhesion promoter is a liquid, and its viscosity at 20 °C or 25 °C is typically at least 2000 mPas, 3000 mPas, 4000 mPas or 5000 mPas. (DIN EN ISO 3219). In some embodiments, the viscosity at 20 °C or 25 °C is no greater than 75,000 mPas. In some embodiments, the viscosity is no greater than 15,000 mPas or 10,000 mPas. In some embodiments, the viscosity is less than 1000 mPas or 500 mPas. In other embodiments, the viscosity of the adhesion promoter at 45 °C, 50 °C or 55 °C can be at least 50,000 mPas, 75,000 mPas, 100,000 mPas, 125,000 mPas or 150,000 mPas. This viscosity indicates the molecular weight. The liquid adhesion promoter can combine with the liquid unpolymerized cyclic olefin more easily than the solid, resulting in a more uniform dispersion of the adhesion promoter within the mixture.

[0153] The adhesion promoter is polymeric, i.e., having a main chain with repeating units (e.g., polyether or polyolefin). In typical embodiments, the molecular weight (Mn) of the polymeric adhesion promoter is no greater than 10,000 g / mol; 9,000 g / mol; 8,000 g / mol; 7,000 g / mol or 6,000 g / mol. In some embodiments, the molecular weight (Mn) of the polymeric adhesion promoter is at least 1000 g / mol, 1100 g / mol, 1200 g / mol, 1300 g / mol, 1400 g / mol, 1500 g / mol, 1600 g / mol, 1700 g / mol, 1800 g / mol, 1900 g / mol or 2000 g / mol.

[0154] Various other adhesion promoters can be used alone or in combination with the polymeric adhesion promoters just described.

[0155] In some embodiments, the adhesion promoter is an aliphatic diisocyanate. The aliphatic diisocyanate contains a straight-chain, branched-chain, or cyclic saturated or unsaturated hydrocarbon group that typically contains from 1 to about 24 carbon atoms. In some embodiments, the alkyl diisocyanate contains at least 2, 3, 4, 5, or 6 carbon atoms. In some embodiments, the aliphatic diisocyanate contains no more than 22, 20, 18, 16, 14, or 12 carbon atoms. Representative examples include hexamethylene diisocyanate (HDI), octamethylene diisocyanate, decamethylene diisocyanate, etc. In some embodiments, the aliphatic diisocyanate contains an alicyclic (e.g., cycloalkyl) moiety that typically has 4 to 16 carbon atoms, such as cyclohexyl, cyclooctyl, cyclodecyl, etc. In one embodiment, the cycloalkyl diisocyanate is isophorone diisocyanate (IPDI) and isomers of isocyanato-[(isocyanatocyclohexyl)methyl]cyclohexane (H 12 MDI).

[0156] In some embodiments, the adhesion promoter is an aromatic diisocyanate. The aromatic diisocyanate contains one or more aromatic rings that are fused or covalently bonded to an organic linking group (such as an alkylene (e.g., methylene or ethylene) moiety). Representative aromatic moieties include phenyl, tolyl, xylyl, naphthyl, biphenyl, diphenyl ether, benzophenone, etc. Suitable aromatic diisocyanates contain 6 to 24 carbon atoms, such as toluene diisocyanate, xylene diisocyanate, benzenedimethyl diisocyanate, tetramethylbenzenedimethyl diisocyanate (TMXDI), and diphenylmethane diisocyanate (MDI), which may comprise any mixture of its three isomers, 2,2'-MDI, 2,4'-MDI, and 4,4'-MDI.

[0157] Other polymeric isocyanates include, for example, PM200 (polymeric MDI); Lupranate TM (polymeric MDI purchased from BASF); various isocyanate-terminated polybutadiene prepolymers available from Cray Valley, including Krasol TM LBD2000 (based on TDI), Krasol TM LBD3000 (based on TDI), Krasol TM NN-22 (based on MDI), Krasol TM NN-23 (based on MDI), and Krasol TM NN-25 (based on MDI).

[0158] In some embodiments, the adhesion promoter is a maleic anhydride grafted styrene-ethylene / butylene-styrene hydrogenated copolymer, typically containing at least 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt% or 0.5 wt% of grafted maleic anhydride. The amount of grafted maleic anhydride is typically not greater than 7 wt%, 6 wt%, 5 wt%, 4 wt%, 3 wt% or 2 wt%. The maleic anhydride grafted styrene-ethylene / butylene-styrene hydrogenated copolymer typically contains at least 10% and not greater than 60%, 50% or 40% polystyrene. Suitable functional elastomers are commercially available under the trade names “Kraton FG1901G” and “Kraton FG1924G” from Kraton Performance Polymers. When present, the (e.g., functional) elastomer is typically present in an amount of at least 0.001 wt%, 0.05 wt% or 0.1 wt% based on the weight of the cyclic olefin.

[0159] Based on the total weight of the composition, the composition typically contains at least 0.005 wt%, 0.010 wt%, 0.050 wt%, 0.10 wt%, 0.50 wt% or 1 wt% of the adhesion promoter. In some embodiments, the amount of the adhesion promoter is not greater than 10 wt%, 9 wt%, 8 wt%, 7 wt%, 6 wt%, 5 wt%, 4 wt%, 3 wt%, 2 wt% or 1 wt% of the total weight of the composition. In some embodiments, the adhesion promoter comprises one or more polymeric polyisocyanates (e.g., diisocyanates) containing an oxygen atom in the main chain. In some embodiments, the adhesion promoter comprises one or more polyolefins containing a maleic anhydride moiety. In some embodiments, the adhesion promoter comprises at least one polymeric polyisocyanate (e.g., diisocyanate) containing an oxygen atom in the main chain and at least one polyolefin containing a maleic anhydride moiety. When two adhesion promoters are used, the amount of each adhesion promoter is typically less than 5 wt%, 4 wt%, 3 wt%, 2 wt% or 1 wt% of the total weight of the composition.

[0160] The adhesive composition may optionally contain one or more conventional additives. Preferred additives include tackifiers, plasticizers, antioxidants, UV stabilizers, colorants and (e.g., inorganic) fillers such as (e.g., fumed) silica and glass bubbles. In some embodiments, little or no tackifier is used (i.e., less than 5 wt%, 4 wt%, 3 wt%, 2 wt% or 1 wt%). When a tackifier is used, its concentration can range from 5 wt% or 10 wt% up to 15 wt% or 20 wt% or more of the (e.g., cured) adhesive composition.

[0161] Cyclic olefins, polymers, and other components can be combined in various methods. In some embodiments, the materials are combined in an organic solvent such as toluene and ethyl acetate. In other embodiments, the cyclic olefin can be combined with the above-described partially polymerized (meth)acrylic slurry.

[0162] The adhesive composition can be applied to a substrate (e.g., a release liner or a backing) using conventional coating techniques. For example, these compositions can be applied to a variety of substrates by methods such as roll coating, flow coating, dip coating, spin coating, spray coating, knife coating, and die coating. The (dry) thickness of the coating is typically in the range of 25 micrometers (e.g., about 1 mil) to 1500 micrometers (60 mils). In some embodiments, the coating thickness is in the range of about 50 micrometers to 350 micrometers.

[0163] The method of applying and polymerizing the cyclic olefin of the composition will vary depending on the desired use of the composition. In advantageous embodiments, polymerization occurs after the adhesive article or adhesive composition is applied to the substrate. However, in alternative embodiments, polymerization of the composition (at least in part) may occur before or simultaneously with the application of the composition to the substrate.

[0164] The adhesive composition can be applied to a variety of flexible (e.g., tape backing materials) and non-flexible substrates. Examples include, for example, plastic films such as polyolefins (e.g., polypropylene, polyethylene), polyvinyl chloride, polyester (polyethylene terephthalate), polycarbonate, poly(methyl)methacrylate (PMMA), cellulose acetate, cellulose triacetate, and ethyl cellulose. In some embodiments, the backing consists of a bio-based material such as polylactic acid (PLA).

[0165] The backing can also be prepared from a fabric, such as a woven fabric formed from threads of synthetic or natural materials such as cotton, nylon, rayon, glass, ceramic materials, etc., or a non-woven fabric such as an air-laid web of natural or synthetic fibers or blends thereof.

[0166] The backing can also be formed from a metal, a metallized polymer film, a ceramic sheet material, or a foam (e.g., polyacrylic, polyethylene, polyurethane, neoprene), etc.

[0167] The adhesive can also be provided in the form of a pressure-sensitive adhesive transfer tape, where at least one layer of the adhesive is disposed on a release liner for later application to a permanent substrate. The adhesive can also be provided as a single-coated or double-coated tape, where the adhesive is disposed on a permanent backing.

[0168] When a cyclic olefin is polymerized with a ROMP catalyst activated by receiving actinic (e.g., UV) radiation, the adhesive composition (e.g., of an adhesive article) can be irradiated with activating UV radiation having a UVA maximum in the wavelength range of 280 nanometers to 425 nanometers. The UV light source can be of various types. Low-intensity light sources such as black lights typically provide intensities in the range of 0.1 mW / cm 2 (milliwatts per square centimeter) or 0.5 mW / cm 2 to 10 mW / cm 2 (measured according to procedures approved by the National Institute of Standards and Technology, such as, for example, using a UVIMAP UM 365L-S radiometer manufactured by Electronic Instrumentation & Technology, Inc., in Sterling, VA, USA). High-intensity light sources typically provide intensities greater than 10 mW / cm 2 , 15 mW / cm 2 or 20 mW / cm 2 , ranging up to 450 mW / cm 2 or greater. In some embodiments, high-intensity light sources provide intensities up to 500 mW / cm 2 , 600 mW / cm 2 , 700 mW / cm 2 , 800 mW / cm 2 , 900 mW / cm 2 or 1000 mW / cm 2 The UV light used to polymerize the cyclic olefin can be provided by various light sources, such as light-emitting diodes (LEDs), black lights, medium-pressure mercury lamps, etc., or combinations thereof. The cyclic olefin can also be polymerized using higher-intensity light sources available from Fusion UV Systems Inc. The UV contact time for polymerization and curing can vary depending on the intensity of the light source used. For example, complete curing using a low-intensity light source can be achieved at contact times in the range of about 30 seconds to 300 seconds; while complete curing using a high-intensity light source can be achieved at shorter exposure times in the range of about 5 seconds to 20 seconds. Partial curing using a high-intensity light source can typically be achieved at exposure times in the range of about 2 seconds to about 5 seconds or 10 seconds.

[0169] Alternatively or in combination, when the cyclic olefin is polymerized with a thermally activated ROMP catalyst, the adhesive is heated as previously described.

[0170] Due to containing a sufficient amount of low Tg (e.g., alkyl (meth)acrylate) monomers, the glass transition temperature “Tg” of the (meth)acrylic polymers and compositions described herein is no greater than 25 °C before polymerizing the cyclic olefin. As used herein, Tg refers to the value obtained by dynamic mechanical analysis according to the test method described in the examples. In some embodiments, before polymerizing the cyclic olefin, the Tg of the (meth)acrylic polymers and compositions is no greater than 20 °C, 15 °C, 10 °C, 5 °C, 0 °C, -5 °C, -10 °C, -15 °C, -20 °C or -25 °C.

[0171] In a typical embodiment, the composition is a pressure-sensitive adhesive before polymerizing the cyclic olefin. In this embodiment, at a frequency of 1 Hz, the storage modulus (G') of the pressure-sensitive adhesive is less than 3×10 5 Pa at, for example, 25 °C. As used herein, the storage modulus (G') refers to the value obtained by dynamic mechanical analysis according to the test method described in the examples. In some embodiments, before polymerizing the cyclic olefin, the pressure-sensitive adhesive composition has a storage modulus of less than 2×10 5 Pa, 1×10 5 Pa, 9×10 4 Pa, 8×10 4 Pa, 7×10 4 Pa, 6×10 4 Pa, 5×10 4 Pa, 4×10 4 Pa or 3×10 4 Pa.

[0172] In some embodiments, such as when the composition contains a combination of a high concentration of pressure-sensitive adhesive polymer and a low concentration of cyclic olefin, the adhesive is a pressure-sensitive adhesive after polymerizing the cyclic olefin. In this embodiment, the storage modulus (G') of the pressure-sensitive adhesive increases due to the inclusion of the polymerized cyclic olefin. In one embodiment, the storage modulus (G') of the adhesive composition increases from about 10 4 to 10 5 , or in other words, increases by a factor of 10.

[0173] As the amount of the polymerized cyclic olefin increases, after polymerizing the cyclic olefin, the adhesive composition is generally not a pressure-sensitive adhesive. In this embodiment, after polymerizing the cyclic olefin, at a frequency of 1 Hz, the storage modulus (G') of the adhesive is at least (e.g., 25 °C) 3×10 5 Pa. In some embodiments, after polymerizing the cyclic olefin, the storage modulus of the adhesive composition is at least 4×10 5 Pa, 5×10 5 Pa, 6×10 5Pa, 7×10 5 Pa, 8×10 5 Pa, 9×10 5 Pa, 1×10 6 Pa, 2×10 6 Pa, 3×10 6 Pa, 4×10 6 Pa, 5×10 6 Pa or greater. In this embodiment, the adhesive composition can be characterized as a structural adhesive composition.

[0174] In some embodiments, after polymerizing the cyclic olefin, the adhesive composition exhibits a lap shear value of at least 100 kPa with aluminum (or other substrates such as polycarbonate and nylon). In some embodiments, after polymerizing the cyclic olefin, the adhesive composition exhibits lap shear values of at least 200 kPa, 300 kPa, 400 kPa, 500 kPa, 600 kPa, 700 kPa, 800 kPa, 900 kPa, 1000 kPa. In some embodiments, after polymerizing the cyclic olefin, the adhesive composition exhibits lap shear values of at least 1500 kPa, 2000 kPa, 2500 kPa, 3000 kPa, 3500 kPa or 4000 kPa. In some embodiments, the lap shear failure mode is cohesive failure, which indicates good adhesion to the substrate.

[0175] The objects and advantages of the present invention are further illustrated by the following examples. The specific materials and amounts, as well as other conditions and details, listed in these examples should not be used to unduly limit the present invention.

[0176] Examples

[0177] Unless otherwise specified or readily apparent from the context, all parts, percentages, ratios, etc. in the examples and the remainder of the specification are by weight.

[0178] Table 1. Materials used in the examples

[0179]

[0180]

[0181] Test Methods

[0182] Preparation of the coated adhesive composition

[0183] Using a slot coater, apply the selected adhesive composition (in an EtOAc / MEK solution) to the non-silicone side of an RL1 silicone-coated polyester release liner with a wet gap of 20 mils or 25 mils (0.51 millimeters (mm) or 0.64 mm), and dry it in a solvent oven at 50 °C for 30 minutes.

[0184] Dynamic Lap Shear Test Method Sample Preparation

[0185] Prepare a 1-inch × 4-inch × 0.064-inch (2.5 centimeters (cm) × 10.2 cm × 0.16 cm) aluminum substrate by scrubbing the last 1 inch (2.54 cm) with a SCOTCH-BRITE General Purpose Hand Pad #7447 (3M, Maplewood, MN), then washing with isopropyl alcohol and air drying. Apply a 1 / 2-inch × 1-inch (1.3 cm × 2.5 cm) portion of the coated adhesive composition to the scrubbed end of one substrate. Remove the release liner. Expose some of the open adhesive samples in the open adhesive samples to light treatment (see Table 2 below). Apply the second substrate to the sample, thus closing the bond (bond area 1 / 2-inch × 1-inch (1.3 cm × 2.5 cm)). Measure the amount of radiation applied to each sample with an EIT PowerPuck II radiometer (EIT, Inc., Sterling, VA). Wet all components by applying finger pressure. Clamp the bond with a large binder clip and allow it to sit at room temperature or in an 80 °C or 90 °C oven for 18 - 24 hours before testing (see Table 2).

[0186] Table 2. Thermal and Light Treatments for Lap Shear Samples

[0187]

[0188] *D Bulb Microwave Source (Heraeus Noblelight America, Gaithersburg, MD)

[0189] **365 nm LED Head OMNICURE 7300 (Excelitas Technologies, Waltham, MA)

[0190] ***RT = Room Temperature

[0191] Dynamic Lap Shear Test

[0192] Dynamic lap shear tests were conducted at ambient temperature using an MTS Criterion Model 43 tensile tester (MTS, Eden Prairie, MN, USA) equipped with an LPS.104C 30 kN load cell (MTS, Eden Prairie, MN, USA). Test specimens were loaded into the grips and the crosshead was operated at 0.1 inches (0.25 cm) per minute to load the specimens to failure. The fracture stress was recorded in pounds per square inch (psi) and converted to kilopascals (kPa). Three specimens of each sample were tested and the average results were calculated.

[0193] Rheological Test Method: Frequency Sweep, followed by Temperature Ramp

[0194] Examples were analyzed by dynamic mechanical analysis (DMA) using a DHR-3 parallel plate rheometer (TA Instruments, New Castle, DE, USA) to characterize the physical properties of each sample as a function of temperature. Rheological property samples were coated to a thickness of approximately 1 mm into the adhesive film between silicone-coated release liners, achieved by laminating them together. The film was then punched out with an 8 mm circular die, removed from the release liner, centered between the 8 mm diameter parallel plates of the rheometer, and compressed until the edges of the sample were flush with the edges of the top and bottom plates.

[0195] While the parallel plates oscillated at an angular frequency of 1 Hz, the temperature was ramped in three steps. In the first two steps, the sample was run at a sensitivity of + / -50 g under an axial force control of 70 g and conditioned for 120 seconds at a start temperature of 25 °C before starting the frequency sweep test. At a constant strain of 1%, a frequency sweep from 0.1 rad / s to 100 rad / s was run. Then the temperature was ramped to 40 °C within 180 seconds before starting the temperature ramp test. Then at a constant strain of 1%, the temperature was ramped down from 40 °C to -50 °C at 3 °C / min until the oscillatory stress exceeded 25,000 Pa, at which point for the remaining temperature ramp steps, the test was automatically changed to a constant stress of 25,000 Pa. If the storage modulus (G') exceeded 4×10^8 Pa, a step termination condition was enabled to stop the low temperature ramp to prevent the adhesive sample from delaminating from the fixture.

[0196] For the third step of the temperature ramp test, reduce the axial force to an axial force control of 25 grams, with a sensitivity of + / - 30 grams, and condition for 60 seconds at a starting temperature of 30 °C before starting this step. Then, ramp the temperature from 30 °C to 150 °C at 3 °C / min while the parallel plates oscillate at an angular frequency of 1 Hz and a constant strain of 5%. If the storage modulus (G') drops below 100 Pa, enable the step termination condition to stop the high-temperature ramp to prevent the adhesive sample from oozing out of the fixture. Record the storage modulus at 1 rad / s and 6.3 rad / s from the frequency sweep. Record the maximum tan(δ) as the Tg from the temperature ramp.

[0197] Gel Permeation Chromatography (GPC)

[0198] The molecular weight distribution of the compound was characterized using conventional gel permeation chromatography (GPC). The GPC instrument obtained from Waters Corporation, Milford, MA includes a high-pressure liquid chromatography pump (model 1515 HPLC), an autosampler (model 717), an ultraviolet detector (model 2487), and a refractive index detector (model 2410). The chromatograph is equipped with two 5-micron PLgel MIXED-D chromatographic columns purchased from Varian Inc., Palo Alto, CA, USA.

[0199] Samples of the polymer solution were prepared by dissolving the polymer or dry polymer material at a concentration of 0.5% (weight / volume) in tetrahydrofuran, and then filtering the solution through a 0.2-micron polytetrafluoroethylene filter (purchased from VWR International, West Chester, PA, USA). The resulting sample was injected into the GPC and eluted at a rate of 1 mL / min through columns maintained at 35 °C. The system was calibrated with polystyrene standards, and a calibration curve was established using linear least-squares fitting analysis. Calculate the weight-average molecular weight (“M w w”) and the polydispersity index (weight-average molecular weight divided by number-average molecular weight) for each sample against this standard calibration curve.

[0200] Preparation Examples

[0201] Acrylic Polymer A Synthesis

[0202] The acrylic polymer A was prepared as follows: 45 grams (g) of BA, 45 g of THFA, 3 g of HPA, 1 g of VAZO 52, 0.1 g of IOTG and 98 g of EtOAc were added to a glass bottle. The contents were mixed and bubbled with nitrogen for 2 minutes, then sealed and placed in a rotating water bath of a Laundrometer (SDL Atlas, Rock Hill, SC) at 60 °C for 24 hours. After 24 hours, the sample was taken out of the Laundrometer and cooled under ambient conditions. The sample was analyzed by GPC and determined that Mw was 459,000 g / mol and the polydispersity index was 5.97. Before use in these examples, the solution was partially dried under a nitrogen stream and the lost solvent was replaced with toluene. The solvent in the final mixture was 2:1 toluene:EtOAc.

[0203] Synthesis of Acrylic Polymer B

[0204] The acrylic polymer B was prepared as follows: 82 g of 2EHA, 10 g of 2EHMA, 5 g of Acm, 3 g of HEA, 0.15 g of VAZO 52, 0.05 g of TDDM and 96.2 g of ethyl acetate were added to a glass bottle. The contents were mixed and bubbled with nitrogen for 2 minutes, then sealed and placed in a rotating water bath of a Laundrometer (SDL Atlas, Rock Hill, SC) at 60 °C for 24 hours. After 24 hours, the sample was taken out of the Laundrometer and cooled under ambient conditions. The sample was analyzed by GPC and determined that Mw was 381,000 g / mol and the polydispersity index was 4.3.

[0205] Synthesis of Acrylic Polymer C

[0206] The acrylic polymer C was prepared as follows: 82 g of 2EHA, 10 g of 2EHMA, 5 g of Acm, 3 g of HEA, 0.15 g of VAZO 52, 0.10 g of TDDM and 96.2 g of ethyl acetate were added to a glass bottle. The contents were mixed and bubbled with nitrogen for 2 minutes, then sealed and placed in a rotating water bath of a Laundrometer (SDL Atlas, Rock Hill, SC) at 60 °C for 24 hours. After 24 hours, the sample was taken out of the Laundrometer and cooled under ambient conditions. The sample was analyzed by GPC and determined that Mw was 265,000 g / mol and the polydispersity index was 3.7.

[0207] Examples

[0208] Example 1 (EX-1): Heat-Curable Tape with CT762

[0209] Assemble the formulations in Table 3 in plastic cups, stir by hand, and then mix at 2000 revolutions per minute (rpm) for 1 minute in a DAC 150.1 FVZ-K high-speed mixer (FlackTek, Inc., Landrum, SC).

[0210] Table 3. Adhesive Composition of Example 1

[0211]

[0212] Prepare the coated adhesive composition (25-mil coating gap) for Formulation EX-1 according to the general procedure described above. Prepare lap shear samples according to the general procedure described above. The methods and results are shown in Table 4.

[0213] Table 4. Lap Shear Sample Treatment and Test Results of Example 1

[0214] Sample Method Average OLS Strength, psi (kPa) Failure Mode 1-A Control M1 3.6±0.1(24.8±0.6) Cohesion 1-B M3 56.6±4.2(389.8±29.0) Adhesive

[0215] Example 2 (EX-2): Photo-Curable Tape with AcI and MOST

[0216] Assemble the formulations in Table 5 in plastic cups, stir by hand, and then mix at 2000 rpm for 1 minute in a DAC 150.1 FVZ-K high-speed mixer.

[0217] Table 5. Adhesive Composition of Example 2

[0218]

[0219] Prepare the coated adhesive composition (25-mil coating gap) for Formulation EX-2 according to the general procedure described above. Prepare lap shear samples according to the general procedure described above. The methods and results are shown in Table 6.

[0220] Table 6. Lap Shear Sample Treatment and Test Results of Example 2

[0221]

[0222] Example 3 (EX-3): Photo-Curable Tape with Ru CII and MOST

[0223] Assemble the formulations in Table 7 in plastic cups, stir by hand, and then mix at 2000 rpm for 1 minute in a DAC 150.1 FVZ-K high-speed mixer.

[0224] Table 7. Adhesive Composition of Example 3

[0225]

[0226] The formulation EX-3 was prepared into a coated adhesive composition (25 mil coating gap) according to the general procedure. Lap shear samples were prepared according to the general procedure. The methods and results are shown in Table 8.

[0227] Table 8. Lap Shear Sample Treatment and Test Results of Example 3

[0228] Sample Method Average OLS Strength, psi (kPa) Failure Mode 3-A Control M1 2.8±0.3(19.1±1.8) Cohesion 3-B M4 105.5±6.4(727.7±44.3) Cohesion 3-C M3 183.8±12.4(1267.5±85.3) Mixed Adhesion 3-D M7 132.7±13.0(914.7±89.4) Mixed Adhesion

[0229] Examples 4 to 7 (EX-4 to EX-7): Photocurable tapes with higher T g Photocurable tapes of acrylic polymers

[0230] The formulations in Table 9 were prepared as follows. First, the acrylic polymer B solution and HPR2128 were assembled in a plastic cup and mixed at 2500 rpm for 1 minute in a DAC 150.1 FVZ-K high-speed mixer. Then, the remaining ingredients were added to the cup and mixed at 2500 rpm for 1 minute in the same high-speed mixer.

[0231] Table 9. Adhesive Compositions of Examples 4 - 7

[0232]

[0233] The formulations EX-4 to EX-7 were prepared into a coated adhesive composition (20 mil coating gap) according to the above general procedure. Lap shear samples were prepared according to the above general procedure, except that for sample 5-B, 1-inch × 4-inch × 0.130-inch (2.5 cm × 10.2 cm × 0.33 cm) nylon 6,6 specimen blocks were used instead of aluminum specimen blocks for preparation. These nylon specimen blocks were not ground but wiped with IPA. The methods and results are shown in Table 10.

[0234] Table 10. Lap Shear Sample Treatment and Test Results of Examples 4 - 7

[0235]

[0236] Example 8 (EX-8): Having a higher T g Photocurable tape containing an acrylic polymer and a norbornene resin

[0237] The formulations in Table 11 were assembled in a plastic cup and mixed at 2000 rpm for 1 minute in a DAC 150.1 FVZ-K high-speed mixer.

[0238] Table 11. Adhesive Composition of Example 8

[0239]

[0240] The formulation EX-8 was prepared into a coated adhesive composition (20-mil coating gap) according to the general procedure described above. Lap-shear samples were prepared according to the general procedure described above, except that for Sample 8-E, 1-inch × 4-inch × 0.175-inch (2.5 cm × 10.2 cm × 0.44 cm) polycarbonate specimen blocks were used instead of aluminum specimen blocks. These polycarbonate specimen blocks were not ground, but were wiped with IPA. The methods and results are shown in Table 12.

[0241] Table 12. Lap Shear Sample Treatment and Test Results of Example 8

[0242] Sample Method Average OLS Strength, psi (kPa) Failure Mode 8-A Control M1 5.0±0.3(34.7±1.8) Mixed Adhesion 8-B M2 355.7±81.8(2452.3±563.9) Cohesion 8-C M5 46.7±4.5(321.8±31.0) Mixed Adhesion 8-D M9 291.0±60.4(2006.4±416.5) Adhesive 8-E (Polycarbonate) M5 21.0±3.6(144.8±24.5) Adhesive

[0243] Examples 9 to 12 (EX-9 to EX-12): Rheological Measurement of the Resin Portion of the Adhesive Composition

[0244] The formulations in Table 13 were prepared as follows. EX-9, EX-10, and EX-11 were prepared according to the formulations and procedures outlined for EX-6, EX-4, and EX-7, respectively, except that no catalyst, photoacid, and solvent additive were used. According to Table 13, Formulations EX-12 and EX-13 are merely parts of acrylic polymers A or B. EX-14, EX-15, and EX-16 were prepared in the same manner as EX-9, EX-10, and EX-11, respectively, except that a catalyst was added.

[0245] Table 13. Compositions and Sample Thicknesses for Rheological Measurement

[0246]

[0247]

[0248] The formulations in Table 13 were prepared into a coated adhesive composition (20-mil coating gap) according to the general procedure described above. The dry adhesive film was folded onto itself three times to achieve a sample thickness of 1 - 2 mm. Examples 9 - 13 were tested as received. Examples 14 - 16 were placed in an 80 °C oven for 24 hours and then returned to ambient conditions. The samples were then tested according to the rheological measurement method in the general procedure section. The results are shown in Table 14.

[0249] Table 14. Rheological Measurement Results of Uncured / Unactivated Tape Compositions 。

[0250]

[0251] Table 15. Rheological Measurement Results of Cured Tape Compositions 。

[0252]

[0253]

[0254]

Claims

1. An adhesive article, the adhesive article comprising: a carrier substrate, the carrier substrate comprising a release liner or a backing; and an adhesive composition disposed on the carrier substrate, wherein the adhesive composition comprises: at least 20 wt% of a polymer having a glass transition temperature (Tg) of less than 25 °C; unpolymerized cyclic olefins; and a latent ring-opening metathesis polymerization catalyst or a precatalyst thereof, wherein the polymer comprises at least 50 wt%, 60 wt%, 70 wt%, 80 wt% or 90 wt% of polymerized units of monomers having a Tg of less than 0 °C; wherein the adhesive article is a tape.

2. The adhesive article according to claim 1, wherein the polymer is a random polymer.

3. The adhesive article according to claim 1, wherein the polymer is a (meth)acrylic polymer.

4. The adhesive article according to claim 3, wherein the (meth)acrylic polymer comprises polymerized units of non-acid-functional polar monomers.

5. The adhesive article according to claim 4, wherein the non-acid-functional polar monomers comprise hydroxyl, ether or amide groups.

6. The adhesive article according to claim 1, wherein the polymer is a pressure-sensitive adhesive having a storage modulus of no greater than 0.3 MPa at a temperature of 25 °C and a frequency of 1 Hz.

7. The adhesive article according to claim 1, wherein prior to polymerizing the cyclic olefins, the adhesive composition is a pressure-sensitive adhesive having a storage modulus of no greater than 0.3 MPa at a temperature of 25 °C and a frequency of 1 Hz.

8. The adhesive article according to claim 1, wherein after polymerizing the cyclic olefins, the adhesive composition is a pressure-sensitive adhesive having a storage modulus of no greater than 0.3 MPa at a temperature of 25 °C and a frequency of 1 Hz.

9. The adhesive article according to claim 1, wherein after polymerizing the cyclic olefins, the adhesive composition is not a pressure-sensitive adhesive having a storage modulus greater than 0.3 MPa at a temperature of 25 °C and a frequency of 1 Hz.

10. The adhesive article according to claim 1, wherein the polymer does not contain functional groups copolymerizable with the cyclic olefins.

11. The adhesive article according to claim 1, wherein the cyclic olefins comprise moieties selected from cyclopentadiene, norbornene and oligomers thereof.

12. The adhesive article according to claim 1, wherein the cyclic olefins are present in an amount in the range of 10 wt% to 80 wt%.

13. The adhesive article according to claim 1, wherein the catalyst is a ruthenium or osmium metal carbene catalyst.

14. The adhesive article according to claim 1, wherein the latent catalyst is activated by heat, actinic radiation, a compound or a combination thereof.

15. The adhesive article according to claim 14, wherein the compound is an acid, a photoacid generator or a thermal acid generator.

16. The adhesive article according to claim 1, wherein the catalyst or its precatalyst has sufficient latency such that after 24 hours at 25 °C, the adhesive composition exhibits a lap shear value with aluminum of less than 30 kPa.

17. The adhesive article according to claim 16, wherein after the polymerization of the cyclic olefin, the adhesive composition exhibits a lap shear value with aluminum of at least 100 kPa.

18. A bonding method, the bonding method comprising: providing the adhesive article according to claims 1 to 17; disposing the adhesive between a first substrate and a second substrate; and polymerizing the cyclic olefin.

19. The method according to claim 18, wherein the cyclic olefin is polymerized by receiving actinic radiation.

20. The method according to claim 19, wherein the cyclic olefin is polymerized by receiving ultraviolet radiation.

21. The method according to claim 18, wherein the cyclic olefin is polymerized by heating.

22. The method according to claim 18, wherein the substrate comprises an organic polymer or an inorganic material.

23. The method according to claim 18, wherein the first substrate and the second substrate comprise the same or different materials.

Images