Hardening composition

Abstract

The present invention relates to a curable composition comprising an oligomer and a low viscosity reactive diluent. The oligomer is a polymerized high T g Monomer units, polymerized low T g The curable composition comprises a monomer unit, a polymerized chromophore monomer unit, and optionally at least one polymerized additional monomer unit. The present invention also relates to the use of the curable composition as a pressure sensitive adhesive curable composition and to a method of coating a substrate.

Description

[Technical Field]

[0001] The present invention relates to a curable composition comprising an oligomer and a low viscosity reactive diluent. The oligomer is a polymerized high T g Monomer units, polymerized low T g The curable composition comprises a monomer unit, a polymerized chromophore monomer unit, and optionally at least one polymerized additional monomer unit. The present invention also relates to the use of the curable composition as a pressure sensitive adhesive curable composition and to a method of coating a substrate. [Background technology]

[0002] Pressure-sensitive adhesive (PSA) systems are generally based on acrylic, styrene block copolymer, or urethane chemistry and have certain drawbacks during processing and film formation. For example, solvent-based PSA systems contain volatile organic compounds that can be difficult to evaporate. Such difficulties limit their application due to environmental and performance requirements.

[0003] Radiation-curable PSA systems offer many advantages over known PSA systems, such as fast cure times, good processability, and environmental safety. However, developing a curable PSA system that achieves desirable properties, such as high peel strength, can be difficult. Therefore, there is a need for radiation-curable PSA systems with high peel strength.

[0004] Embodiments of the curable compositions disclosed herein overcome the drawbacks associated with known PSA systems. Summary of the Invention

[0005] A first aspect of the present invention is a curable composition comprising an oligomer and a low viscosity reactive diluent having a viscosity of 3000 cP or less at 25° C. The oligomer comprises 1% to 80% by weight of polymerized high T g Monomer units having a glass transition temperature (T g a high T selected from (meth)acrylate monomers having gMonomer units: 10% to 98.9% by weight of polymerized low T g Monomer units with a T of 25°C or less g a low T selected from monovalent (meth)acrylate monomers having g The oligomer comprises: 0.1% to 40% by weight of polymerized chromophore monomer units selected from (meth)acrylate monomers having pendant Norrish Type II chromophores; and 0% to 20% by weight of at least one polymerized additional monomer unit. The oligomer has a weight average molecular weight of at least 10,000 grams per mole (g / mol). The oligomer has a T of -10°C or less. g The curable composition has a viscosity of 50,000 cP or less at 60°C.

[0006] The present invention also provides a method for preparing the curable composition of the present invention, comprising the steps of: - preparing the oligomer described herein by dissolving it in a non-reactive solvent; - adding a low viscosity reactive diluent to obtain a diluted curable composition; - removing at least a portion of the non-reactive solvent from the diluted curable composition to obtain the curable composition. The present invention relates to a method, comprising:

[0007] The present invention also relates to a method of curing the curable composition of the present invention or a curable composition prepared by the method of the present invention, comprising curing the curable composition by irradiating the curable composition with a light source having a wavelength and / or intensity capable of activating the polymerized chromophore monomer units of the oligomer and causing crosslinking of the oligomer and / or the reactive diluent. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a graph of gel content of cured comparative and example examples according to one or more embodiments described herein. [Figure 2]FIG. 2 is a graph of gel content of cured comparative and example examples according to one or more embodiments described herein. [Figure 3] FIG. 3 is a graph of gel content of cured comparative and example examples according to one or more embodiments described herein. [Figure 4] FIG. 4 is a graph of cure rate and heat flow area under the curve for comparative examples and examples according to one or more embodiments described herein. [Figure 5] FIG. 5 is a graph of cure rate and heat flow area under the curve for comparative examples and examples according to one or more embodiments described herein. [Figure 6] FIG. 6 is a graph of cure rates for examples according to one or more embodiments described herein. [Figure 7] FIG. 7 is a graph of peel strength versus average load for examples according to one or more embodiments described herein. [Figure 8] FIG. 8 is a graph of average load versus peel strength for comparative examples and examples according to one or more embodiments described herein. [Figure 9] FIG. 9 is a graph of average load versus peel strength for comparative examples and examples according to one or more embodiments described herein. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Definition] As used herein, the term "comprises a" may mean "comprise one or more."

[0010] Unless otherwise specified, weight percentages in compounds or compositions are expressed relative to the respective weight of the compound or composition.

[0011] The term "substituted" herein means that at least one hydrogen atom (-H) bonded to a carbon or heteroatom of the corresponding unsubstituted compound or functional group is replaced by a substituent (e.g., R SThe term "hypersubstituted" means that every hydrogen atom (H) bonded to a carbon atom or heteroatom of the corresponding unsubstituted compound or functional group is replaced with a substituent (e.g., R S The term "polysubstituted" means that at least two (but not all) hydrogen atoms bonded to carbon atoms or heteroatoms of the corresponding unsubstituted compound or functional group are replaced with a substituent. Unless otherwise defined or limited by the specific context, a substituent in general, or R S The substituent R may be any chemical moiety, typically, but not necessarily, having from 1 to 50, or from 1 to 40, or from 1 to 30, or from 1 to 20, or from 1 to 10 total atoms. S Examples of R include, but are not limited to, hydrocarbyl, heterohydrocarbyl, aryl, heteroaryl, alkyl, cycloalkyl, heteroatom, carbonyl, hydroxy, ester, ether, amine, amide, or halide, according to each definition herein or its commonly understood meaning, any of which substituents may themselves be substituted or unsubstituted. S is (C1-C 30 ) hydrocarbyl, (C1-C 30 ) heterohydrocarbyl, (C6-C 30 ) aryl, or (C6-C 30 ) heteroaryl.

[0012] The term "hydrocarbyl" refers to a group in which each hydrocarbon is aromatic or non-aromatic, saturated or unsaturated, straight or branched chain, cyclic (having three or more carbons, including monocyclic and polycyclic, fused and non-fused polycyclic, and bicyclic) or acyclic, and is substituted with one or more R S In this disclosure, hydrocarbyl can be unsubstituted or substituted alkyl, unsubstituted or substituted cycloalkyl, or unsubstituted or substituted aryl. Hydrocarbyl may be free of any heteroatoms selected from O, N, or S. (C-C 30) Hydrocarbyl is a hydrocarbyl having 1 to 30 carbon atoms.

[0013] The term "heterohydrocarbyl" means a hydrocarbyl having one or more heteroatoms independently selected from O, N, or S. (C-C 30 ) Heterohydrocarbyl is a heterohydrocarbyl having 1 to 30 carbon atoms.

[0014] The term "aryl" refers to an optionally substituted polyunsaturated aromatic group. An aryl can contain a single ring (i.e., phenyl) or more than one ring in which at least one ring is aromatic. When an aryl contains more than one ring, the rings can be fused together via a covalent bond (e.g., biphenyl). The aromatic ring can optionally contain one or two additional fused rings (i.e., cycloalkyl, heterocycloalkyl, or heteroaryl). Examples include phenyl, naphthyl, biphenyl, phenanthrenyl, and naphthacenyl.

[0015] The term "alkyl" refers to a group of the formula -C n H 2n+1 (n is 1 to 20). Alkyl can be straight-chained or branched. Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, 2-methylbutyl, 2,2-dimethylpropyl, n-hexyl, 2-methylpentyl, 2,2-dimethylbutyl, n-heptyl, 2-ethylhexyl, and the like.

[0016] The term "cycloalkyl" means a monovalent saturated alicyclic hydrocarbon group containing a ring. Examples of cycloalkyl groups include cyclopentyl, cyclohexyl, and isobornyl, any of which may be substituted or unsubstituted.

[0017] The term "heterocycloalkyl" means a cycloalkyl having at least one ring atom which is a heteroatom selected from O, N, or S.

[0018] The term "halogen" means an atom selected from Cl, Br, F and I.

[0019] The term "alkoxy" means a radical of the formula --O-alkyl, where alkyl is as defined above.

[0020] The term "aryloxy" means a group of the formula --O-aryl, where aryl is as defined above.

[0021] The term "thioalkyl" means a radical of the formula -S-alkyl, where alkyl is as defined above.

[0022] The term "thioaryl" means a radical of the formula -S-aryl, where aryl is as defined above.

[0023] The term "alkenyl" means a monovalent acyclic hydrocarbon group containing at least one C=C double bond. Alkenyl can be straight-chain or branched.

[0024] The term "alkynyl" means a monovalent acyclic hydrocarbon group containing at least one C≡C triple bond. Alkynyl can be straight-chained or branched.

[0025] The term "aralkyl" means an aryl substituted with an alkyl group. An example of an aralkyl group is tolyl.

[0026] The term "alkaryl" refers to an alkyl substituted with an aryl group. An example of an alkaryl group is benzyl (-CH-phenyl).

[0027] The term "heteroaryl" means an aryl having at least one ring atom that is a heteroatom.

[0028] The term "alkylamino" means an alkyl substituted with at least one amino group.

[0029] The term "alkylthiol" means an alkyl substituted with at least one thiol group.

[0030] The term "hydroxyalkyl" means an alkyl substituted with at least one hydroxy group.

[0031] The term "haloalkyl" means an alkyl substituted with at least one halogen.

[0032] The term "alkylene" refers to a group of the formula C m H 2m+2 By removing one hydrogen atom at each point of attachment of the linker from an alkane of the formula: Alkylene may be divalent, trivalent, tetravalent, or have a higher valency.

[0033] The term "alkoxylated" refers to a compound, group, or linker that contains one or more oxyalkylene moieties, particularly one or more oxyalkylenes selected from oxyethylene (-O-CH-CH-), oxypropylene (-O-CH-CH(CH)- or -O-CH(CH)-CH-), oxybutylene (-O-CH-CH-CH-CH-), and mixtures thereof. For example, an alkoxylated compound, group, or linker can contain from 1 to 30 oxyalkylene moieties.

[0034] The term "(meth)acrylate" means acrylate or methacrylate. The term "acrylate" means an acryloyloxy group (-O-C(=O)-CH=CH2). The term "methacrylate" means a methacryloyloxy group (-O-C(=O)-C(CH3)=CH2).

[0035] The term (meth)acrylate monomer means a monomer having a (meth)acrylate group.

[0036] As used herein, a "monomer" has a number average molecular weight of less than 1000 g / mol, preferably from 100 to 950 g / mol.

[0037] As used herein, an "oligomer" has a number average molecular weight of 1000 g / mol or greater, preferably 1050 to 60000 g / mol, more preferably 10000 to 50000 g / mol.

[0038] As used herein, "number average molecular weight ("M n ")" or "weight average molecular weight ("M w ")" is quantified using size exclusion chromatography (SEC) using poly(methyl methacrylate) reference standards and tetrahydrofuran as the solvent unless expressly stated otherwise.

[0039] "Glass transition temperature" or "T g The term "glassy" refers to the temperature at which a material changes from a glassy state to a rubbery state. In this context, "glassy" means that the material is hard and brittle, and "rubbery" means that the material is elastic and flexible. For polymeric materials, T g is the critical temperature that separates glassy and rubbery behavior. g At temperatures below T, the material is essentially frozen, so large-scale molecular motion is severely restricted. g When the material is at a temperature above this temperature, molecular motion occurs on the scale of its repeating unit, causing it to become flexible or rubbery.

[0040] Monomer T g All references herein to T of a homopolymer formed from that monomer. g The general monomer is T g Values are well known from the literature. If not reported in the literature, glass transition temperature values are determined by the inflection temperature (T) according to ASTM E1356-08, "Standard Test Method for Assignment of Glass Transition Temperatures by Differential Scanning Calorimetry." iThe glass transition temperatures of the oligomers described herein and referred to in the examples below can be determined as the mass fraction of each individual monomer in an oligomer or polymeric material comprising more than one distinct type of monomer and the T g The T value of the curable composition upon curing is calculated using the Fox equation. g is determined by the ASTM E1356-08 DSC method described above, or by shear rheology if this is not possible due to the lack of a detectable inflection point.

[0041] The terms "mass fraction" and "weight fraction" are used interchangeably herein and are considered equivalent to each other with respect to embodiments or examples herein.

[0042] "Fox formula" refers to formula (1): TIFF2025525559000001.tif10170 where T g,mix is the glass transition temperature of a mixture of i chemically distinct components, such as two or more distinct monomers of an oligomer or polymer, and T g,i is the glass transition temperature of the i-th component, and ω i is the mass fraction of the i-th component based on the total mass of the oligomer or polymer. Hereinafter, T g,mix The value of T is calculated by the Fox equation for multiple separate monomers. g " is called.

[0043] For two components, A and B, the Fox equation simplifies to equation (2): TIFF2025525559000002.tif9170

[0044] "High T g The term "monomer unit" refers to a unit that, when homopolymerized, has a T of 25°C or higher. g It refers to a monomer that produces a homopolymer with a high T g In embodiments of the oligomer where only monomer units are present, high T g Monomer unit T g is a kind of high Tg T of homopolymer of monomer units g Two or more distinct high T g In embodiments of the oligomer where the monomer unit is present, the high T g Monomer unit T g In equation (1), the individual mass fractions ω i is not based on the total mass of the entire oligomer, but on all high T g Monomer units (i.e., T above 25°C) g Each individual high T in the oligomer is based on the total mass of the monomer unit having g High T, the mass fraction of monomer units g Fox equation average T for a combination of monomer units g This collectively refers to the following.

[0045] The term "Fox average" may also be used herein with respect to a single monomer that is not part of a mixture of two or more monomers. g is the mass fraction term in such a situation, ω, equals 1, so the T of a single monomer itself, as defined here, g It should be easy to see that it is equivalent to

[0046] “Low T g The term "monomer unit" refers to a unit that, when homopolymerized, has a T g It refers to a monomer that produces a homopolymer with a low T g In embodiments of the oligomer where only monomer units are present, low T g Monomer unit T g is a kind of low T g T of homopolymer of monomer units g Two or more distinct low T g In embodiments of the oligomer where the monomer unit is present, the low T g Monomer unit T g In equation (1), the individual mass fractions ω iis not based on the total mass of the entire oligomer, but on all low T g Monomer units (i.e., T<25°C) g Each individual low T in the oligomer is based on the total mass of the monomer unit having g Low T, the mass fraction of monomer units g Fox equation average T for a combination of monomer units g This collectively refers to the following.

[0047] The term "photoinitiator" can be considered to be any type of substance that, when exposed to radiation (e.g., actinic radiation), forms a species that initiates the reaction and curing of polymerized organic materials present in a curable composition.

[0048] The term "chromophore" as used herein refers to a Norrish Type II light-absorbing molecule that absorbs light and enters an excited state from which it can interact or react with other molecules to generate reactive radical species.

[0049] When used to describe a given carbon atom-containing chemical group, "A 1 -A 3 " is an expression of the form A, which contains 1 and 3. 1 From A 3 Each A in the range x For example, "A 1 -A 3 " is an expression of the form A 1 , A 2 and A 3 "Z" 1 -Z 3 " is an expression of the form Z, which contains 1 and 3. 1 From Z 3 Each Z in the range x For example, "Z 1 -Z 3 " is an expression of the form Z 1 , Z 2 , and Z 3 Refers to...

[0050] The term "independently selected" is used herein to describe a substituent, e.g., Z1 , Z 2 , Z 3 , and Z 4 is used to indicate that the 1 , Z 2 , Z 3 , and Z 4 may all be -CH3, or Z 1 and Z 2 is -CH3, Z 3 and Z 4 (e.g., may be -H). Chemical names associated with substituents are intended to convey chemical structures recognized in the art as corresponding to the structures of the chemical names. Thus, chemical names are intended to supplement and illustrate, rather than preclude, structural definitions known to those of skill in the art.

[0051] When used to describe a given carbon atom-containing chemical group, "(C x -C y A parenthetical expression of the form "(C1-C2)" means that the unsubstituted form of the chemical group contains x and y, and has from x carbon atoms to y carbon atoms. For example, (C1-C2) 20 ) Hydrocarbyl is a hydrocarbyl group having 1 to 20 carbon atoms in its unsubstituted form. In some embodiments and general structures, a given chemical group is R S The parenthesized "(C x -C y )" for the chemical group R S Substituted versions may be formed by adding any group R S Depending on the identity of R, the compound may contain more than y carbon atoms. For example, "exactly one group R" S (C1-C 20 ) alkyl (where R S The term "phenyl (-C6H5)" can contain from 7 to 27 carbon atoms. x -C y ) is a group defined using one or more carbon atom-containing substituents R SIf the chemical group is substituted with any carbon atom-containing substituent R, the minimum and maximum total number of carbon atoms in the chemical group must be less than or equal to the number of carbon atoms in the group. S It is determined by adding the combined total of the numbers of carbon atoms from both x and y.

[0052] The term "-H" means a hydrogen atom covalently bonded to a non-hydrogen atom. "Hydrogen" and "-H" are interchangeable and have the same meaning unless expressly specified otherwise.

[0053] "(C1-C 30 The term "hydrocarbyl" means a monovalent hydrocarbon of 1 to 30 carbon atoms, each of which may be aromatic or non-aromatic, saturated or unsaturated, straight or branched chain, cyclic (having 3 or more carbons, including monocyclic and polycyclic, fused and non-fused polycyclic, and bicyclic) or acyclic, and may contain one or more R S In this disclosure, the term "substituted" refers to a group selected from the group consisting of (C1-C 30 ) hydrocarbyl is unsubstituted or substituted (C-C 30 ) alkyl, (C3-C 30 ) cycloalkyl, or (C6-C 30 ) aryl.

[0054] "(C2-C 30 The term "alkyl" refers to an unsubstituted or one or more R S means a saturated straight or branched chain monovalent hydrocarbon substituted with unsubstituted (C2-C 30 Examples of alkyl are unsubstituted (C-C 20 ) alkyl; unsubstituted (C6-C 25 ) alkyl; unsubstituted (C4-C8) alkyl; 1-butyl; 2-butyl; 2-methylpropyl; 1,1-dimethylethyl; 1-pentyl; 1-hexyl; 1-heptyl; 1-nonyl; and 1-decyl. 30 Examples of substituted (C-C 20 ) alkyl, substituted (C2-C 10 ) alkyl.

[0055] "(C6-C40 The term "aryl" refers to an unsubstituted or (one or more R)aryl having from 6 to 40 carbon atoms, of which at least 6 to 14 carbon atoms are aromatic ring carbon atoms. S (with) substituted monocyclic, bicyclic, or tricyclic aromatic monovalent hydrocarbons. Monocyclic aromatic monovalent hydrocarbons contain one aromatic ring; bicyclic aromatic monovalent hydrocarbons have two rings; and tricyclic aromatic monovalent hydrocarbons have three rings. When bicyclic or tricyclic aromatic monovalent hydrocarbons are present, at least one of the rings of the monovalent hydrocarbon is aromatic. The other rings of the aromatic monovalent hydrocarbon may independently be fused or non-fused, and aromatic or non-aromatic. Unsubstituted (C6-C 40 Examples of aryl include unsubstituted (C-C 20 )Aryl, unsubstituted (C6-C 18 )aryl; 2-(C1-C5)alkyl-phenyl; phenyl; fluorenyl; tetrahydrofluorenyl; idacenyl; hexahydracenyl; hexahydroindacenyl; indenyl; dihydroindenyl; naphthyl; tetrahydronaphthyl; and phenanthrene. 40 Examples of aryl include substituted (C-C 20 ) aryl; and substituted (C6-C 18 ) aryl.

[0056] "(C6-C 12 The term "cycloalkyl" means an unsubstituted or substituted saturated cyclic monovalent hydrocarbon of 6 to 12 carbon atoms. Other cycloalkyl groups, such as (C x -C y )cycloalkyl) similarly has x to y carbon atoms and is unsubstituted or has one or more R S is defined as being substituted with unsubstituted (C6-C 12 Examples of cycloalkyl include unsubstituted (C-C)cycloalkyl, unsubstituted (C-C 10 ) cycloalkyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, and cyclodecyl. 12Examples of cycloalkyl include substituted (C-C)cycloalkyl, substituted (C-C 10 ) cycloalkyl, isobornyl, and 3,3,5-trimethylcyclohexyl.

[0057] The term "heteroatom" refers to an atom other than hydrogen or carbon. Examples of heteroatoms include O, S, N, and Si. The term "heterohydrocarbon" refers to a molecule or molecular framework in which one or more carbon atoms of a hydrocarbon are replaced by a heteroatom. "(C1-C 30 The term "(C-C) heterohydrocarbyl" means a monovalent heterohydrocarbon of 1 to 30 carbon atoms. 30 The term "heterohydrocarbylene" means a divalent heterohydrocarbon of 1 to 30 carbon atoms. (C-C 30 ) heterohydrocarbyl or (C-C 30 The heterohydrocarbon of the heterohydrocarbylene has one or more heteroatoms. The valence or point of attachment of the heterohydrocarbyl can be on a carbon atom or a heteroatom. The two valences of the heterohydrocarbylene can be on a single carbon atom or a single heteroatom. In addition, one of the two valences or points of attachment of the diradical can be on a carbon atom and the other on another carbon atom; one of the two valences or points of attachment can be on a carbon atom and the other on a heteroatom; or one of the two valences or points of attachment can be on a heteroatom and the other valence or point of attachment can be on another heteroatom. Each (C-C 30 ) heterohydrocarbyl and (C-C 30 ) Heterohydrocarbylene can be unsubstituted or substituted, aromatic or non-aromatic, saturated or unsaturated, straight or branched chain, cyclic (including monocyclic and polycyclic, fused and non-fused polycyclic), or acyclic.

[0058] The term "saturated" means lacking carbon-carbon double bonds, carbon-carbon triple bonds, and (in the case of heteroatom-containing groups) carbon-nitrogen, carbon-phosphorus, and carbon-silicon double bonds. A saturated chemical group may be bound to one or more substituents R SWhen substituted with one or more double and / or triple bonds, one or more double and / or triple bonds may be replaced by the substituent R S The term "unsaturated" means containing one or more carbon-carbon double bonds, carbon-carbon triple bonds, or (in the case of heteroatom-containing groups) one or more carbon-nitrogen, carbon-phosphorus, or carbon-silicon double bonds, if any, in the substituent R S This does not include double bonds which may be present in the (hetero)aromatic ring, if any.

[0059] The term "linker" refers to a polyvalent group. A linker can link together at least two moieties of a compound, particularly 2 to 16 moieties of a compound. For example, a linker that links two moieties of a compound is called a bivalent linker, and a linker that links three moieties of a compound is called a trivalent linker.

[0060] [Oligomer] The curable compositions disclosed herein include an oligomer, wherein the oligomer comprises at least one polymerized chromophore monomer unit as defined herein. The oligomer, wherein the oligomer comprises at least one polymerized high T g Monomer units and at least one polymerized low T g The oligomer herein optionally comprises at least one polymerized additional monomer unit as defined herein. The oligomer herein further comprises a polymerized high T g Monomer units, polymerized low T g The polymerized high T g Monomer units, polymerized low T g The total weight of the monomer units, polymerized chromophore monomer units, and polymerized additional monomer units may account for at least 97%, particularly at least 98%, more particularly at least 99%, and even more particularly 100% of the total weight of the oligomer.

[0061] The oligomers described herein may be composed of different monomer units (i.e., high T g Monomer unit, low T gThe oligomer may be formed by polymerization of different monomer units (a chromophore monomer unit, a chromophore monomer unit, and optionally at least one additional monomer unit). Common methods known in the art include, but are not limited to, solution polymerization. Thus, the oligomer may be obtained by polymerizing different monomer units dissolved in a non-reactive solvent in the presence of an initiator. Solution polymerization may be carried out at a temperature of at least 50°C, preferably at least 60°C. Examples of suitable non-reactive solvents include toluene, heptane, ethyl acetate, methyl ethyl ketone (MEK), isopropanol, and combinations thereof. The initiator may be a thermal initiator. Thermal initiators are well known in the art and include, for example, peroxides (i.e., compounds containing an oxygen-oxygen single bond), particularly inorganic persulfate compounds such as ammonium persulfate, potassium persulfate, and sodium persulfate; hydrogen peroxide; organic peroxides such as cumene hydroperoxide, t-butyl hydroperoxide, acetyl peroxide, benzoyl peroxide, and lauroyl peroxide; peracids such as peracetic acid and perbenzoic acid; redox initiators in which a reducing agent, such as a ferrous compound, accelerates the decomposition of the peroxide; and azo initiators (i.e., compounds containing a nitrogen-nitrogen double bond), such as 2,2'-azobisisobutyronitrile, 4,4'-azobis(4-cyanovaleric acid), or 2,2'-azobis(2-methylbutyronitrile), as well as other free radical generators, and combinations thereof. The initiator can be added in an amount such that the total monomer:initiator weight ratio is 100:1 to 1000:1. Solution polymerization typically results in a mixture of oligomers dissolved in a non-reactive solvent. The non-reactive solvent can be removed by heating. A reactive diluent can be added before removing the non-reactive solvent to form a curable composition, as described in more detail below. The mixture at the end of the solution polymerization (i.e., before the introduction of the reactive diluent) can have a solids content of 25% to 70%, preferably 30% to 50%, by weight, based on the total weight of the mixture. The mixture can have a residual monomer content of less than 2%, particularly less than 1%, and more particularly less than 0.5%, by weight, based on the total weight of the mixture.Using experimental conditions familiar to those skilled in the art, the experimental parameters of the solution polymerization (i.e., solids content, reaction temperature, reaction time, and total monomer:initiator ratio) can be adjusted to produce relatively low molecular weight oligomers.

[0062] Preferably, the oligomers are not obtained by telomerization, i.e., in the presence of telogen compounds (i.e., compounds having at least one cleavable bond selected from CH, SH, PH, Si-H, or CX (where X = Cl, Br, or I)), such as tetrabromomethane (CBr), bromotrichloromethane (CBrCl), dibromodichloromethane (CBrCl), mercaptans, hydrogen disulfide, etc.

[0063] In embodiments, the oligomer may have a weight average molecular weight of at least 10,000 grams per mole (g / mol). In embodiments, the oligomer may have a weight average molecular weight of 10,000 g / mol to 600,000 g / mol. In embodiments, the oligomer may have a weight average molecular weight of 10,000 g / mol or more, 25,000 g / mol or more, or even 50,000 g / mol or more. In embodiments, the oligomer may have a weight average molecular weight of 600,000 g / mol or less, 500,000 g / mol or less, 400,000 g / mol or less, 300,000 g / mol or less, 200,000 g / mol or less, or even 100,000 g / mol or less. In embodiments, the oligomer has a molecular weight of 10,000 g / mol to 600,000 g / mol, 10,000 g / mol to 500,000 g / mol, 10,000 g / mol to 400,000 g / mol, 10,000 g / mol to 300,000 g / mol, 10,000 g / mol to 200,000 g / mol, 10,000 g / mol to 100,000 g / mol, 25,000 g / mol to 600,000 g / mol, 25,000 g / mol to 500,000 g / mol, 25,000 g / mol to 400,000 g / mol, 25,000 g / mol to 3,000 g / mol, The polymer may have a weight average molecular weight of 00 g / mol, 25,000 g / mol to 200,000 g / mol, 25,000 g / mol to 100,000 g / mol, 50,000 g / mol to 600,000 g / mol, 50,000 g / mol to 500,000 g / mol, 50,000 g / mol to 400,000 g / mol, 50,000 g / mol to 300,000 g / mol, 50,000 g / mol to 200,000 g / mol, or even 50,000 g / mol to 100,000 g / mol, or any subrange formed from any of these endpoints.

[0064] In a preferred embodiment, the oligomer may have a weight average molecular weight of from 10,000 g / mol to 100,000 g / mol, particularly from 10,000 g / mol to 50,000 g / mol, in particular from 11,000 g / mol to 49,000 g / mol, more particularly from 12,000 g / mol to 48,000 g / mol, even more particularly from 15,000 g / mol to 45,000 g / mol, and even more particularly from 15,000 g / mol to 40,000 g / mol.

[0065] In embodiments, the oligomer has a glass transition temperature T of −10° C. or less to ensure that the curable composition is suitable for a given application, such as use as a pressure sensitive adhesive. g In embodiments, the oligomer may have a T of −10° C. or less, e.g., −15° C. or less, −20° C. or less, −25° C. or less, or −30° C. or less. g In embodiments, the oligomer may have a T of −120° C. or higher, −100° C. or higher, −80° C. or higher, or −60° C. or higher. g In embodiments, the oligomer may have a T of -10°C to -120°C, -10°C to -100°C, -10°C to -80°C, -10°C to -60°C, -15°C to -120°C, -15°C to -100°C, -15°C to -80°C, -15°C to -60°C, -20°C to -120°C, -20°C to -100°C, -20°C to -80°C, -0°C to -60°C, -25°C to -120°C, -25°C to -100°C, -25°C to -80°C, -25°C to -60°C, -30°C to -120°C, -30°C to -100°C, -30°C to -80°C, or even -30°C to -60°C, or any and all subranges formed from any of these endpoints. g may have.

[0066] The amount of oligomer in the curable composition varies depending on the desired viscosity. In embodiments, the curable composition may comprise 20% to 80% by weight of oligomer, based on the weight of the curable composition. In embodiments, the curable composition may comprise 20% or more, 25% or more, 30% or more, 35% or more, or even 40% or more by weight of oligomer, based on the weight of the curable composition. In embodiments, the curable composition may comprise 80% or less, 75% or less, 70% or less, 65% or less, or even 60% or less by weight of oligomer, based on the weight of the curable composition. In embodiments, the amount by weight of oligomer in the curable composition can be from 20% to 80%, 20% to 75%, 20% to 70%, 20% to 75%, 20% to 60%, 25% to 80%, 20% to 75%, 25% to 70%, 25% to 75%, 25% to 60%, 30% to 80%, 30% to 75%, 30% to 70%, 30% to 75%, 30% to 60%, 35% to 80%, 35% to 75%, 35% to 70%, 35% to 75%, 35% to 60%, 40% to 80%, 40% to 75%, 40% to 70%, 40% to 75%, or even 40% to 60%, based on the total weight of the curable composition, or any and all subranges formed from any of these endpoints.

[0067] In an embodiment, the oligomer has the formula (O): TIFF2025525559000003.tif54170 (in the above formula, - Each A 1 are independently H, (C1-C 30 ) hydrocarbyl or (C-C 30 ) heterohydrocarbyl, preferably H or (C-C 30 ) hydrocarbyl; - Each A 2 are independently (C2-C 30 ) hydrocarbyl or (C-C 30 ) heterohydrocarbyl, preferably (C4-C 30 ) hydrocarbyl; - Each A 3 are independently monovalent residues containing a Norrish type II chromophore; - Each A4 are independently (C1-C 30 ) hydrocarbyl or (C-C 30 ) heterohydrocarbyl; -Z 1 , Z 2 , Z 3 , and Z 4 are independently -H or -CH; - m is polymerized high T g is the weight fraction of monomer units; - n polymerized low T g is the weight fraction of monomer units; - p is the weight fraction of polymerized chromophore monomer units; and q is the weight fraction of at least one polymerized additional monomer unit, optionally 0; and - m+n+p+q is equal to 1) It has.

[0068] In the oligomer according to formula (O), m can be from 0.01 to 0.80; n can be from 0.10 to 0.989, p can be from 0.001 to 0.4, and q can be from 0 to 0.2.

[0069] In some embodiments, q is 0, and thus no additional polymerized monomer units are present in the oligomer.

[0070] A 1 , A 2 , A 3 , A 4 , Z 1 , Z 2 , Z 3 , Z 4 Further preferred descriptions of m, n, p and q are defined below for each corresponding monomer unit.

[0071] [High T g Monomer units] The oligomers disclosed herein are polymerized high T g Contains monomer units. High T g The monomer unit is a low T gThe monomer units, chromophore monomer units, and additional monomer units are different. Therefore, high T g The monomer units may not contain any of the following groups: - chromophore moiety; - functional groups as defined below for the additional monomer units.

[0072] Polymerized High T g The monomer units can be the same or a combination of multiple types of separate monomer units, such as, for example, two separate monomer units, three separate monomer units, four separate monomer units, or more than four separate monomer units. g The monomer unit has a glass transition temperature (T g ) or Fox-style average T g As defined herein, the T g A reference here to a T of a homopolymer formed from that monomer. g The oligomer is a combination of two or more distinct high T g In embodiments containing monomer units, T g As previously described here, high T g Fox average T of the monomer unit g In an embodiment, high T g Fox average T of the monomer unit g is 25°C or higher, e.g., 30°C or higher, 35°C or higher, 40°C or higher, 45°C or higher, 50°C or higher, 55°C or higher, 60°C or higher, 65°C or higher, 70°C or higher, 75°C or higher, or 80°C or higher. gThe monomer units are from 25°C to 200°C, 25°C to 150°C, 25°C to 130°C, 30°C to 200°C, 30°C to 150°C, 30°C to 130°C, 35°C to 200°C, 35°C to 150°C, 35°C to 130°C, 40°C to 200°C, 40°C to 150°C, 40°C to 130°C, 45°C to 200°C, 45°C to 150°C, 45°C to 130°C, 50°C to 200°C, 50°C to 150°C, 50°C to 130°C, T of 55°C to 200°C, 55°C to 150°C, 55°C to 130°C, 60°C to 200°C, 60°C to 150°C, 60°C to 130°C, 65°C to 200°C, 65°C to 150°C, 65°C to 130°C, 70°C to 200°C, 70°C to 150°C, 70°C to 130°C, 75°C to 200°C, 75°C to 150°C, or even 75°C to 130°C, or any and all subranges formed from any of these endpoints. g may have.

[0073] High T g Fox average T of the monomer unit g is low T g Fox average T of the monomer unit g In an embodiment, the high T g Fox average T of the monomer unit g is low T g Fox average T of the monomer unit g In an embodiment, the high T g Fox average T of the monomer unit g and low T g Fox average T of the monomer unit g is greater than 20°C, e.g., greater than 25°C, greater than 30°C, greater than 35°C, greater than 40°C, greater than 45°C, greater than 50°C, greater than 55°C, greater than 60°C, greater than 65°C, greater than 70°C, greater than 75°C, greater than 80°C, greater than 85°C, greater than 90°C, greater than 95°C, greater than 100°C, greater than 105°C, greater than 110°C, greater than 115°C, or even greater than 120°C. g Fox average T of the monomer unit g and low T g Fox average T of the monomer unit gis at least 200°C, at least 150°C, at least 120°C, at least 100°C, at least 90°C, at least 80°C, at least 70°C, at least 60°C, at least 50°C, at least 40°C, or even at least 30°C. g Fox average T of the monomer unit g and low T g Fox average T of the monomer unit g The difference between the temperature and the temperature is 20°C to 200°C. g Fox average T of the monomer unit g and low T g Fox average T of the monomer unit g The difference is 20℃ to 200℃, 20℃ to 150℃, 20℃ to 120℃, 20℃ to 100℃, 20℃ to 90℃, 20℃ to 80℃, 20℃ to 70℃, 20℃ to 60℃, 20℃ to 50℃, 20℃ to 40℃, 20℃ to 30℃, 30℃ to 200℃, 30℃ to 150℃, 30℃ to 120℃, 30℃ to 1 00℃, 30℃ to 90℃, 30℃ to 80℃, 30℃ to 70℃, 30℃ to 60℃, 30℃ to 50℃, 30℃ to 40℃, 40℃ to 200℃, 40℃ to 150℃, 40℃ to 120℃, 40℃ to 100℃, 40℃ to 90℃, 40℃ to 80℃, 40℃ to 70℃, 40℃ to 60℃, 40℃ to 50℃, 5 The temperature may be 0°C to 200°C, 50°C to 150°C, 50°C to 120°C, 50°C to 100°C, 50°C to 90°C, 50°C to 80°C, 50°C to 70°C, 50°C to 60°C, 60°C to 200°C, 60°C to 150°C, 60°C to 120°C, 60°C to 100°C, 60°C to 90°C, 60°C to 80°C, 60°C to 70°C, 70°C to 200°C, 70°C to 150°C, 70°C to 120°C, 70°C to 100°C, 70°C to 90°C, 70°C to 80°C, 80°C to 200°C, 80°C to 150°C, 80°C to 120°C, 80°C to 100°C, or 80°C to 90°C, or any and all subranges formed from any of these endpoints.

[0074] High T gThe monomer units consist of one or more (meth)acrylate monomers, preferably one or more monofunctional (meth)acrylate monomers.

[0075] In an embodiment, high T g The monomer units are monovalent. g The monomer units may be polyvalent, in which case each monomer unit contains two or more active sites that participate in crosslinking upon curing. Examples of monovalent monomer units may include ethyl methacrylate and tert-butyl acrylate. Examples of polyvalent monomer units may include divalent monomer units such as dicyclopentadienyl diacrylate.

[0076] In an embodiment, high T g Each of the monomer units (before being polymerized to form the backbone of the oligomer) independently has the formula (I): TIFF2025525559000004.tif48170 (in the above formula, -A 1 is H, (C1-C 30 ) hydrocarbyl or (C-C 30 ) heterohydrocarbyl, preferably H or (C-C 30 ) hydrocarbyl; and -Z 1 is -H or -CH3) can be obeyed.

[0077] For example, in an embodiment, A 1 is H, methyl, ethyl, isopropyl, isobutyl, tert-butyl, substituted or unsubstituted (C6-C 12 ) cycloalkyl, or combinations thereof. 1 may be selected from H, methyl, tert-butyl, isobornyl, cyclohexyl, or 3,3,5-trimethylcyclohexyl, or a combination thereof.

[0078] The above embodiment is also directed to A in an oligomer of formula (O) 1 The same applies to

[0079] Appropriate high T g Examples of monomer units include, but are not limited to, (meth)acrylic acid, 2-phenylethyl methacrylate, 3,3,5-trimethylcyclohexyl acrylate, tert-butyl acrylate, octadecyl methacrylate, octadecyl acrylate, propyl methacrylate, benzyl methacrylate, isobutyl methacrylate, ethyl methacrylate, 2,2,3,3-tetrafluoropropyl methacrylate, 2,2,2-trifluoroethyl methacrylate, isopropyl methacrylate, isobornyl acrylate, methyl methacrylate, isobornyl methacrylate, phenyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, 4-tert-butylcyclohexyl acrylate, 4-tert-butylcyclohexyl methacrylate, 3,3,5-trimethylcyclohexyl acrylate, 3,3,5-trimethylcyclohexyl methacrylate, substituted or unsubstituted (C6-C 12 ) cycloalkyl(meth)acrylate, adamantyl(meth)acrylate, tricyclodecanemethanol mono(meth)acrylate, or a combination thereof.

[0080] Preferably, the oligomer has a high T g The monomer units are selected from methyl methacrylate, tert-butyl (meth)acrylate, (meth)acrylic acid, isobornyl (meth)acrylate, or combinations thereof. Alternatively, the oligomer has a high T g The monomer units are selected from methyl methacrylate, acrylic acid, isobornyl acrylate, and isobornyl methacrylate or combinations thereof.

[0081] More preferably, the oligomer has a high T g The monomer units are selected from methyl methacrylate, tert-butyl acrylate, or a mixture of methyl methacrylate and acrylic acid.

[0082] Polymerized high T in oligomerg The weight fraction of the monomer unit is T g The desired properties of the oligomer, such as molecular weight, gel content after curing, etc., will vary. In embodiments, the oligomer comprises 1 wt. % to 80 wt. % polymerized high T g The oligomer may contain multiple distinct types of polymerized high T g If it contains a monomer unit, the polymerized high T g The weight fraction of the monomer units in the oligomer is g It should be understood that the total weight fraction of any individual type of monomer unit is equal to the sum of the individual weight fractions of any separate type of monomer unit.

[0083] In embodiments, the oligomer comprises from 1% to 50%, or from 3% to 44%, by weight of polymerized high T based on the total weight of the oligomer. g In embodiments, the oligomer may comprise 1% or more, 3% or more, 5% or more, 15% or more, or even 25% or more by weight of polymerized high T monomer units, based on the total weight of the oligomer. g In embodiments, the oligomer may comprise no more than 80%, no more than 70%, no more than 60%, no more than 50%, no more than 44%, no more than 30%, or even no more than 20% by weight of polymerized high T monomer units, based on the total weight of the oligomer. g In an embodiment, the oligomer may contain polymerized high T gThe amount by weight of the monomer units may be from 1% to 80%, 1% to 70%, 1% to 60%, 1% to 50%, 1% to 44%, 1% to 30%, 1% to 20%, 3% to 80%, 3% to 70%, 3% to 60%, 3% to 50%, 3% to 44%, 3% to 30%, 3% to 20%, 5% to 80%, 5% to 70%, 5% to 60%, 5% to 50%, 5% to The range may be 44%, 5% to 30%, 5% to 20%, 15% to 80%, 15% to 70%, 15% to 60%, 15% to 50%, 15% to 44%, 15% to 30%, 15% to 20%, 25% to 80%, 25% to 70%, 25% to 60%, 25% to 50%, 25% to 44%, or even 25% to 30%, or any and all subranges formed from any of these endpoints.

[0084] The above values also represent the polymerized high T g It corresponds to the weight fraction m of the monomer unit.

[0085] [Low T g Monomer units] The oligomers disclosed herein have low T g Contains monomer units. Low T g The monomer unit is a high T g A distinction is made between monomer units, chromophore monomer units, and additional monomer units. g The monomer units may not contain any of the following groups: - chromophore moiety; - functional groups as defined below for the additional monomer units.

[0086] Polymerized Low T g The monomer units can be the same or a combination of multiple types of separate monomer units, such as two separate monomer units, three separate monomer units, four separate monomer units, or more than four separate monomer units. g The monomer units have a glass transition temperature (T g ) as defined herein.g The reference to a T of the homopolymer formed from that monomer g In an embodiment, low T g The monomer units have a glass transition temperature (T g ) or Fox average T below 25°C g As defined herein, the T of the monomers herein may have g The reference to a T of the homopolymer formed from that monomer g It refers to a compound that has two or more different low T g In embodiments containing monomer units, T g is the low T g Fox average T of the monomer unit g In an embodiment, low T g The monomer units have a Fox average T of less than 25°C, e.g., less than 20°C, less than 15°C, less than 10°C, less than 5°C, less than 0°C, less than -5°C, less than -10°C, less than -15°C, less than -20°C, or less than -30°C. g It has.

[0087] In a further embodiment, low T g The monomer units have a Fox average T g In an embodiment, the low T gThe monomer units are -150°C to 25°C, -150°C to 20°C, -125°C to 15°C, -125°C to 10°C, -125°C to 5°C, -125°C to 0°C, -125°C to -5°C, -125°C to -10°C, -125°C to -15°C, -125°C to -20°C, -125°C to -30°C, -125°C to 25°C, -125°C to 20°C, -125°C to to 15℃, -125℃ to 10℃, -125℃ to 5℃, -125℃ to 0℃, -125℃ to -5℃, -125℃ to -10℃, -125℃ to -15℃, -125℃ to -20℃, -125℃ to -30℃, -100℃ to 25℃, -100℃ to 20℃, -100℃ to 15℃, -100℃ to 10℃, -100℃ to 5℃, -100℃ to 0℃, - 100℃ to -5℃, -100℃ to -10℃, -100℃ to -15℃, -100℃ to -20℃, -100℃ to -30℃, -80℃ to 25℃, -80℃ to 20℃, -80℃ to 15℃, -80℃ to 10℃, -80℃ to 5℃, -80℃ to 0℃, -80℃ to -5℃, -80℃ to -10℃, -80℃ to -15℃, -80℃ to -20℃, - T of 80°C to -30°C, -60°C to 25°C, -60°C to 20°C, -60°C to 15°C, -60°C to 10°C, -60°C to 5°C, -60°C to 0°C, -60°C to -5°C, -60°C to -10°C, -60°C to -15°C, -60°C to -20°C, or even -60°C to -30°C, or any and all subranges formed from any of these endpoints. g may have.

[0088] low T g The monomer units consist of one or more (meth)acrylate monomers, preferably one or more monofunctional (meth)acrylate monomers.

[0089] In an embodiment, low T g The monomer units may be monovalent. gThe monomer units may include (meth)acrylate monomers, including acrylate and methacrylate monomers. Examples of acrylate monomers include sec-butyl acrylate and n-butyl acrylate monomers. Examples of methacrylate monomers include butyl methacrylate and pentyl methacrylate monomers.

[0090] In an embodiment, low T g Each of the monomer units (before being polymerized into the backbone of the oligomer) independently has the formula (II): TIFF2025525559000005.tif47170 (in the above formula, -A 2 is (C2-C 30 ) hydrocarbyl or (C-C 30 ) heterohydrocarbyl, preferably (C4-C 30 ) hydrocarbyl; and -Z 2 is -H or -CH3) can be obeyed.

[0091] In an embodiment, A 2 is linear or branched (C2-C 30 ) alkyl, preferably linear or branched (C4-C 30 ) alkyl. In one embodiment, A 2 is selected from n-butyl, isobutyl, hexyl, 2-ethylhexyl, isooctyl, isodecyl, tridecyl, lauryl, or combinations thereof.

[0092] The above embodiment is also directed to the A of the oligomer of formula (O) 2 The same applies to

[0093] Low T of oligomers gFurther examples of monomer units include, but are not limited to, monomer units selected from n-butyl (meth)acrylate, isobutyl acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, isodecyl (meth)acrylate, tridecyl (meth)acrylate, lauryl (meth)acrylate, nonyl acrylate, decyl (meth)acrylate, octyl (meth)acrylate, propyl acrylate, isobutyl acrylate, 2,2,3,3-tetrafluoropropyl acrylate, ethyl acrylate, sec-butyl acrylate, dodecyl acrylate, tetradecyl (meth)acrylate, isopropyl acrylate, pentyl (meth)acrylate, benzyl acrylate, cyclohexyl acrylate, hexadecyl (meth)acrylate, 2-methylbutyl acrylate, 2-octyl acrylate, or combinations thereof.

[0094] Preferably, the oligomer has a low T g The monomer unit is n-butyl acrylate.

[0095] Polymerized low T in oligomers g The weight fraction of the monomer units determines the desired properties of the oligomer, e.g., T g In embodiments, the oligomer comprises 10% to 98.9% by weight of polymerized low T based on the total weight of the oligomer. g The oligomer may contain multiple distinct types of polymerized low T g If it contains monomer units, the polymerized low T g The weight fraction of monomer units is the weight fraction of any separate type of polymerized low T g It should be understood that this is equal to the sum of the individual weight fractions of the monomer units.

[0096] In embodiments, the oligomer comprises 50% to 97%, or 55% to 95%, by weight of polymerized low T based on the total weight of the oligomer. gIn embodiments, the oligomer may comprise 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, 55% or more, 60% or more, 70% or more, or even 80% or more by weight of polymerized low T monomer units, based on the total weight of the oligomer. g In embodiments, the oligomer may comprise no more than 98.9%, no more than 97%, no more than 95%, no more than 85%, or even no more than 75% by weight of polymerized low T monomer units, based on the total weight of the oligomer. g In an embodiment, the oligomer may comprise a polymerized low T g The amount by weight of the monomer units is based on the total weight of the oligomer and may range from 10% to 98.9%, 10% to 97%, 10% to 95%, 10% to 85%, 10% to 75%, 20% to 98.9%, 20% to 97%, 20% to 95%, 20% to 85%, 20% to 75%, 30% to 98.9%, 30% to 97%, 30% to 95%, 30% to 85%, 30% to 75%, 40% to 98.9%, 40% to 97%, 40% to 95%, 40% to 85%, 40% to 75%, 50% to 85%, 50% to 95%. It can be 0% to 98.9%, 50% to 97%, 50% to 95%, 50% to 85%, 50% to 75%, 55% to 98.9%, 55% to 97%, 55% to 95%, 55% to 85%, 55% to 75%, 70% to 98.9%, 70% to 97%, 70% to 95%, 70% to 85%, 70% to 75%, 80% to 98.9%, 80% to 97%, 80% to 95%, or even 80% to 85%, or any and all subranges formed from any of these endpoints.

[0097] The above values also represent the polymerized low T g It corresponds to the weight fraction n of the monomer unit.

[0098] low T g Monomer units and high T g The weight ratio of the monomer units is determined by the desired properties of the oligomer, e.g., T g and gel content after curing. In an embodiment, low T g Monomer units and high T gThe weight ratio of the monomer units can be 24:1 to 1.5:1, 20:1 to 1.5:1, 15:1 to 1.5:1, 10:1 to 1.5:1, 24:1 to 3:1, 20:1 to 3:1, 15:1 to 3:1, 10:1 to 3:1, 24:1 to 5:1, 20:1 to 5:1, 15:1 to 5:1, or 10:1 to 5:1, or any and all subranges formed from any of these endpoints.

[0099] [Chromophore Monomer Unit] At least one polymerized high-T g Monomer units and at least one polymerized low T g In addition to the combination of monomer units, the oligomer further comprises at least one polymerized chromophore monomer unit. The chromophore monomer unit has a high T g Monomer unit, low T g A distinction is made between monomer units and additional monomer units.

[0100] The polymerized chromophore monomer units act as photoinitiators, allowing radiation to induce curing of the oligomer. Photoinitiators are generally moieties that, upon absorption of light, generate reactive species (ions or radicals) that initiate one or several chemical reactions or transformations.

[0101] The photoinitiator may include a free radical photoinitiator. The photoinitiator may be selected to be susceptible to activation by photons of wavelengths related to the actinic radiation (e.g., ultraviolet, visible light) intended to be used to cure the curable composition. Norrish Type II (i.e., non-cleavable) photoinitiator moieties do not decompose upon excitation, reducing the likelihood of small molecules leaching from the matrix composition. For reference, see, for example, A. Gilbert and J. Baggott: "Essentials of Molecular Photochemistry," Blackwell, London, 1991. Excited non-cleavable photoinitiators do not decompose into radicals upon excitation, but rather abstract hydrogen atoms from organic molecules or, more efficiently, abstract electrons from electron donors (such as amines or thiols). Electron transfer generates a radical anion on the photoinitiator and a radical cation on the electron donor. Subsequent proton transfer from the radical cation to the radical anion generates two uncharged radicals; of these, the radical on the electron donor is sufficiently reactive to abstract a hydrogen atom from most substrates.

[0102] The photoinitiator can be a chromophore. Benzophenone and related ketones, such as thioxanthone, xanthone, anthraquinone, fluorenone, dibenzosuberone, benzil, and phenylketocoumarin, are examples of Norrish Type II chromophores. Most amines and many thiols with a C-H bond alpha to the nitrogen atom are electron donors. Some titanocenes are Norrish Type II chromophores within the scope of the chromophoric monomers herein.

[0103] In embodiments, the polymerized chromophore monomer unit is a (meth)acrylate ester monomer having a pendant Norrish Type II chromophore, i.e., the Norrish Type II chromophore is not located at the terminal end of the monomer.

[0104] Any of the above-described Norrish Type II chromophores can be pendant moieties of chromophore monomer units of an oligomer. In embodiments, the Norrish Type II chromophore is selected from benzophenone, thioxanthone, or titanocene. In a particular example, the Norrish Type II chromophore is benzophenone.

[0105] In an embodiment, each of the chromophore monomer units (prior to being polymerized into the backbone of the oligomer) independently has the formula (III): TIFF2025525559000006.tif42170 (in the above formula, A 3 is a monovalent residue containing a Norrish type II chromophore, especially A 3 is X or -LX; L is (C1-C 10 ) heterohydrocarbylene linker; X is a monovalent residue of a Norrish type II chromophore; Z 3 is -H or -CH3) can be obeyed.

[0106] In an embodiment, A of formula (III) 3 is X or -LX, where L is (C1-C 10 ) heterohydrocarbylene linker, and X is a monovalent residue of a Norrish Type II chromophore. As used in this disclosure, the term "residue" is intended to mean the product of the reaction, such as a moiety remaining from a monomer in a polymer, such as a portion of a Norrish Type II chromophore. In other embodiments, A 3 is a monovalent residue of a Norrish type II chromophore. In embodiments, X can be a monovalent residue of any one of the Norrish type II chromophores described above. In embodiments, A 3 is a monovalent residue of benzophenone. 3 is represented by formula (IV): I have TIFF2025525559000007.tif49170.

[0107] Examples of suitable chromophore monomer units may include, but are not limited to, (meth)acrylates of Norrish Type II photoinitiators such as benzophenone or thioxanthone.

[0108] In an embodiment, A of formula (III) 3 is a residue containing a monovalent radical comprising a moiety selected from thioxanthone, anthraquinone, or camphorquinone. 3 is a residue containing a monovalent radical containing thioxanthone.

[0109] In particular, A of formula (III) 3 is represented by the following formula (V) or (VI): TIFF2025525559000008.tif96170 (wherein, in formula (V) and formula (VI), L 1 is alkylene; L 2 is a bivalent linker containing at least two carbon atoms; Each R 1 and R 2 is -H, halogen, alkyl, cycloalkyl, heterocycloalkyl, alkoxy, aryloxy, thioalkyl, thioaryl, alkenyl, alkynyl, aryl, aralkyl, alkaryl, heteroaryl, -C(=O)R a , -NR b R c , alkylamino, alkylthiol, haloalkyl, -NO2, -CN, -C(=O)OR d , -C(=O)NR b R c are independently selected from; R a is selected from optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted heterocycloalkyl, and optionally substituted aryl; and R b , R c and R d are independently selected from —H, alkyl, and aryl. may have.

[0110] In particular, in formula (V) and formula (VI), R 1 and R 2 are independently -H, halogen, alkyl or alkoxy. More particularly, R 1 and R 2 are independently H or alkyl. Even more particularly, R 1 and R 2 are independently H or methyl. And more particularly, R 1 and R 2 are all -H.

[0111] In formula (V) and formula (VI), L 1 is alkylene. In particular, each L 1 can independently be a straight or branched alkylene having 1 to 6, 1 to 4, or 1 to 2 carbon atoms. 1 is -CH2- or -CH(CH3)-. Even more particularly, L 1 is -CH2-.

[0112] In formula (V) and formula (VI), L 2 is a divalent linker containing at least two carbon atoms. 2 can be an aromatic, aliphatic or alicyclic hydrocarbon linker, a polyether linker, a polyester linker, a polycarbonate linker, a polycaprolactone linker, a polyurethane linker, a polyorganosiloxane linker, a polybutadiene linker, and combinations thereof. In particular, L 2 may be selected from aromatic, aliphatic or alicyclic hydrocarbon linkers, polyether linkers, polyester linkers, and combinations thereof.

[0113] In formula (V) and formula (VI), L 2can be -CH-CH(OH)-CH- or the residue of a diol. As used herein, the term "residue of a diol" refers to a linker obtained by removing two OH groups from a diol. Examples of suitable diols include 1,3-propylene glycol, 1,3- or 1,4-butylene glycol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, 2-methyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 3,3-dimethyl-1,5-pentanediol, neopentyl glycol, 2,4-diethyl-1,5-pentanediol, cyclohexanediol, cyclohexane-1,4-dimethanol, norbornene dimethanol, norbornane dimethanol, tricyclodecane diol, tricyclodecane dimethanol, bisphenol A, B, F or S, hydrogenated bisphenols, Included are phenols A, B, F or S, di-, tri- or tetraethylene glycol, di-, tri- or tetrapropylene glycol, di-, tri- or tetrabutylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, poly(ethylene glycol-co-propylene glycol), dianhydrohexitols (i.e., isosorbide, isomannide, isoidide), polybutadiene polyols, polyester polyols, polyether polyols, polyorganosiloxane polyols, polycarbonate polyols, and their alkoxylated (e.g., ethoxylated and / or propoxylated) derivatives, as well as derivatives obtained by ring-opening polymerization of ε-caprolactone initiated with one of the aforementioned polyols.

[0114] In formula (V) and formula (VI), L 2 is -CH 2- It can be CH(OH)—CH— or a bivalent linker selected from one of formulas (A)-(E): TIFF2025525559000009.tif51170 (in the above formula, R 22 , R’22 , R 25 , R ’25 , R 29 , R ’29 , R 30 and R ’30 are independently H or alkyl; R 23 , R ’23 , R 24 , R ’24 , R 26 , R ’26 , R 27 , R ’27 , R 28 and R ’28 are independently H or methyl; a is from 2 to 20; b, d, and d' are independently 2 to 4; c is 1 to 20; e and e' are independently 0 to 20, provided that at least one of q and q' is not 0; f is from 2 to 20; g is 3 to 12; h is 1 to 20; i is from 2 to 8; j is from 2 to 20; k is from 2 to 30; l is 1 to 20)

[0115] In particular, in formula (V) and formula (VI), L 2 is -CH 2-CH(OH)-CH2- or alkylenes such as 1,3-propanediyl, 1,3- or 1,4-butanediyl, 1,5-pentanediyl, 1,6-hexanediyl, 1,8-octanediyl, 1,9-nonanediyl, 1,10-decanediyl, 1,12-decanediyl, 2-methyl-1,3-propanediyl, 2,2-diethyl-1,3-propanediyl, 3-methyl-1,5-pentanediyl, 3,3-dimethyl-1,5-pentanediyl, 2,2-dimethyl-1,3-propanediyl, 2,4-diethyl-1,5-pentanediyl; oxylated (especially ethoxylated and / or propoxylated) derivatives; esterified derivatives of the aforementioned alkylenes (especially by ring-opening polymerization of lactones such as ε-caprolactone); divalent linkers selected from the residues of di-, tri-, tetra- or polyoxyalkenes containing no OH groups, such as di-, tri- or tetraethylene glycol, di-, tri- or tetrapropylene glycol, di-, tri- or tetrabutylene glycol, polyethylene glycol, polypropylene glycol, polybutylene glycol, poly(ethylene glycol-co-propylene glycol).

[0116] In some embodiments, A of formula (III) 3 is represented by the following formula (Va) or (Vb): TIFF2025525559000010.tif74170 (where h is between 1 and 20) Follow one of the following.

[0117] Other suitable linker groups may also be used, including those that do not contain a carbonyl group.

[0118] A in formula (III) 3 All of the embodiments described above for A of the oligomer of formula (O) 3The weight fraction of polymerized chromophore monomer units in the oligomer will vary based on factors known in the art, such as the desired cure time, among other factors. In embodiments, the oligomer may contain at least 0.1 wt. % polymerized chromophore units, based on the total weight of the oligomer, to ensure improved peel strength. In embodiments, the oligomer may contain 0.1 wt. % to 40 wt. % polymerized chromophore monomer units, based on the total weight of the oligomer. It should be understood that when an oligomer contains multiple distinct types of polymerized chromophore monomer units, the weight fraction of polymerized chromophore monomer units in the oligomer is equal to the sum of the individual weight fractions of all distinct types of polymerized chromophore monomer units. Furthermore, even if the chromophore monomer units are T g Based solely on high T g Monomer or low T g Any monomer containing a pendant chromophore, even if characterized as a high T g Low T even in monomers g It should be understood that it is also considered to be a monomer.

[0119] In embodiments, the oligomer may comprise 0.1 to 10%, particularly 0.1 to 2%, by weight of polymerized chromophore monomer units, based on the total weight of the oligomer. In embodiments, the oligomer may comprise 0.1% or more, 0.25% or more, 0.5% or more, or 1% or more by weight of polymerized chromophore monomer units, based on the total weight of the oligomer. In embodiments, the oligomer may comprise 40% or less, 30% or less, 20% or less, 10% or less, 5% or less, 2% or less, or even 1% or less by weight of polymerized chromophore monomer units, based on the total weight of the oligomer. In embodiments, the amount by weight of polymerized chromophore monomer units in the oligomer is from 0.1% to 40%, 0.1% to 30%, 0.1% to 20%, 0.1% to 10%, 0.1% to 5%, 0.1% to 2%, 0.1% to 1%, 0.25% to 40%, 0.25% to 30%, 0.25% to 20%, 0.25% to 10%, 0.25% to 5%, 0.1% to 2%, 0.1% to 1%, 0.25% to 40%, 0.25% to 30%, 0.25% to 20%, 0.25% to 10%, 0.25% to 5%, 0.1% to 20%, 0.1% to 10%, 0.25% to 5%, 0.1% to 20%, 0.1% to 10%, 0.1 ... It can be 0.25% to 2%, 0.25% to 1%, 0.5% to 40%, 0.5% to 30%, 0.5% to 20%, 0.5% to 10%, 0.5% to 5%, 0.5% to 2%, 0.5% to 1%, 1% to 40%, 1% to 30%, 1% to 20%, 1% to 10%, 1% to 5%, or even 1% to 2%, or any and all subranges formed from any of these endpoints.

[0120] In preferred embodiments, the amount by weight of polymerized chromophore monomer units in the oligomer is from 0.5% to 30%, particularly from 0.5% to 20%, more particularly from 0.5% to 15%, even more particularly from 0.5% to 10%, and more particularly from 1% to 10%, based on the total weight of the oligomer.

[0121] The above value also corresponds to the weight fraction p of polymerized chromophore monomer units in the oligomer of formula (O).

[0122] [Additional Monomer Unit] The oligomers disclosed herein optionally include at least one additional polymerized monomer unit. The additional monomer unit has a high T g Monomer unit, low Tg The monomer unit and the chromophore monomer unit are different.

[0123] The additional monomer units are g Monomer unit, low T g The monomer units may include monomer units copolymerized with the chromophore monomer units.

[0124] The additional monomer units may be polymerizable groups other than (meth)acrylate groups (i.e., vinyl groups, allyl groups, conjugated diene groups, alkenyl groups), acidic groups (i.e., carboxylic acid groups other than the carboxylic acid group of (meth)acrylic acid), phosphonic acid (-P(=O)(OH)2) groups, phosphonate (-P(=O)(OR)2) groups, sulfonic acid (-S(=O)2OH) groups, sulfonate (-S(=O)2OR) groups, phosphate (-OP(=O)(OR)2) groups (wherein each R independently represents a counter ion, hydrogen The functional group may be selected from the group consisting of a hydroxyl group, an ester group, an acrylate group, an alkyl group, an alkyl acrylate group, an alkyl methacrylate group, an alkyl ...

[0125] (Meth)acrylic acid has high T g It should be emphasized that the amount by weight of polymerized (meth)acrylic acid units corresponds to the amount of polymerized high T g It should be considered in the total amount of monomer units, not in the total amount of additional polymerized monomer units.

[0126] In embodiments, the additional monomer units may include monomer units other than (meth)acrylic monomer units, such as vinyl amides, vinyl ethers, vinyl esters, vinyloxazolidinones, (meth)acrylamides, and combinations thereof. In embodiments, the additional monomer units may include other monomer units polymerized into the oligomer, such as styrene derivatives and maleimides.

[0127] In embodiments, the additional monomer units can include epoxy, ether, ester, acid, or ketone functional groups that are not polymerized within the oligomer. For example, the additional monomer units can include caprolactone-extended acrylate (SR495B, Sartomer), cyclic trimethylolpropane formal acrylate (SR531, Sartomer), propoxylated tetrahydrofurfuryl acrylate (SR611, Sartomer), beta-carboxyethyl acrylate, glycidyl methacrylate, or 2-(2-ethoxyethoxy)ethyl acrylate (SR256), neopentyl monomethacrylate, tetrahydrofurfuryl (meth)acrylate, phenoxyethyl acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-cyanobutyl acrylate, 4-cyanobutyl acrylate, 2-cyanoethyl acrylate, cyanomethyl acrylate, and combinations thereof.

[0128] In embodiments, the additional monomer units may be monomers that act synergistically with the polymerized chromophore monomer units and / or reduce oxygen inhibition, which can limit surface cure and thus performance of the resulting cured product.

[0129] Common synergist functional groups that function as synergists for Type II photoinitiators can include tertiary amine functional groups, alkyleneoxy functional groups, mercaptan groups, or other sources of readily abstractable hydrogen. Exemplary additional monomer units containing synergist functional groups include monomers such as dimethylaminoethyl acrylate (DMAEA), dimethylaminoethyl methacrylate (DMAEMA), diethylaminoethyl acrylate (DEAEA), diethylaminoethyl methacrylate (DEAEMA), N-vinylpyrrolidone (NVP), N-vinylcaprolactam (VCAP), acryloxymorpholine (ACMO), dimethylacrylamide (DMAC), poly(ethylene oxide) mono(meth)acrylate, hydroxyethyl ethylene urea (meth)acrylate (HEEU(M)A), the reaction product of a cyclic anhydride with a hydroxy-functional (meth)acrylate, and combinations thereof.

[0130] In embodiments, the additional monomer unit can include an amine synergist. Some examples of amine synergists include tertiary amines. When an amine synergist-containing monomer is included in an oligomer in conjunction with the Norrish Type II chromophore of a polymerized chromophore monomer unit, the tertiary amine provides an active hydrogen donor site to the excited triplet state of the chromophore, resulting in the generation of a reactive alkylamino radical that can subsequently initiate polymerization. Tertiary amines can also reduce the effect of oxygen on cure by converting non-reactive peroxy species formed by the reaction of oxygen with free radicals into reactive alkylamino radicals.

[0131] In embodiments, the additional monomeric unit may be selected from (meth)acrylate monomers having pendant amine functional groups. In embodiments, the additional monomeric unit is a (meth)acrylate monomer having pendant amine functional groups.

[0132] Examples of amine synergists that can serve as additional monomers for the oligomer include, but are not limited to, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, acryloylmorpholine, dimethylacrylamide, monoacrylated polyethylene glycol, monoacrylated propylene glycol, N-vinylpyrrolidone, or combinations thereof. Further examples of suitable amine synergists that can serve as additional monomers for the oligomer include low molecular weight tertiary amines (i.e., tertiary amines having a molecular weight less than 200 g / mol), such as triethanolamine and N-methyldiethanolamine. Other types of amine synergists are aminobenzoates, polymeric aminobenzoates, polymeric aminobenzoates, and mixtures thereof. Examples of aminobenzoates include ethyl 4-(dimethylamino)benzoate (EDB), pentyl 4-(dimethylamino)benzoate, 2-ethylhexyl 4-(dimethylamino)benzoate, and 2-butoxyethyl 4-(dimethylamino)benzoate (BEDB).

[0133] In an embodiment, the additional monomer unit is a (meth)acrylate monomer having a pendant amine functional group.

[0134] Any of the synergists described above or amine-based synergists may be pendant residues in additional monomer units of the oligomers herein.

[0135] In an embodiment, each of the additional monomer units (before being polymerized into the backbone of the oligomer) independently has the formula (VI): TIFF2025525559000011.tif35170 (in the above formula, -A 4 is (C1-C 30 ) hydrocarbyl or (C-C 30) heterohydrocarbyl, preferably having functional groups selected from acidic groups, nitrogen-containing groups, hydroxyl groups, epoxy groups, carbonyl groups, acetoacetoxy groups, acetoacetamide groups, 1,1-dimethyl-3-oxobutyl (diacetone) groups, thiol groups, silane groups, ether bonds, ester bonds, and combinations thereof (C1-C 30 ) heterohydrocarbyl -Z 4 is -H or -CH3) can be obeyed.

[0136] A 4 may comprise the monovalent residue of any one of the synergists discussed above. 4 is -H or -CH3, and A 4 is -C(=O)-OR 4 where R 4 is selected from H, dimethylaminomethyl, dimethylaminoethyl, morpholino, dimethylamino, -CH-CH-imidazolidinone, or a combination thereof. 4 is -H and A 4 includes heterocycles having one or more nitrogen ring atoms, e.g., A 4 can correspond to one of the following expressions: TIFF2025525559000012.tif29170

[0137] The above embodiment is also directed to A in an oligomer of formula (O) 4 and Z 4 applies equally to

[0138] The weight fraction of polymerized additional monomer units in an oligomer varies depending on factors well known in the art, such as the desired cure time and the desired degree of cure. In embodiments, the oligomer may contain from 0% to 20% by weight of polymerized additional monomer units, based on the total weight of the oligomer. In embodiments, the oligomer may contain 0% or more, 0.5% or more, 1% or more, or even 3% or more by weight of polymerized additional monomer units, based on the total weight of the oligomer. In embodiments, the oligomer may contain 20% or less, 15% or less, 10% or less, or even 5% or less by weight of polymerized additional monomer units, based on the total weight of the oligomer. In embodiments, the amount by weight of polymerized additional monomer units in the oligomer can be from 0% to 20%, 0% to 15%, 0% to 10%, 0% to 5%, 0.5% to 20%, 0.5% to 15%, 0.5% to 10%, 0.5% to 5%, 1% to 20%, 1% to 15%, 1% to 10%, 1% to 5%, 3% to 20%, 3% to 15%, 3% to 10%, or even 3% to 5%, based on the total weight of the oligomer, or any and all subranges formed from any of these endpoints.

[0139] Preferably, the amount by weight of polymerized additional monomer units in the oligomer may be from 0% to 20%, especially from 0 to 10%, based on the total weight of the oligomer.

[0140] [Low viscosity reactive diluent] The curable compositions disclosed herein include low viscosity reactive diluents that can be used in conjunction with solvents or can replace solvents entirely.

[0141] In embodiments, the low-viscosity reactive diluent may have a viscosity of 3000 cP or less, such as 2750 cP or less, 2500 cP or less, 2250 cP or less, 2000 cP or less, 1750 cP or less, 1500 cP or less, or even 1250 cP or less, when measured with a Brookfield DV-III viscometer using spindle SC-27 at 25° C. In embodiments, the low-viscosity reactive diluent may have a viscosity of 5 cP or more, such as 25 cP or more, 50 cP or more, 100 cP or more, 250 cP or more, 500 cP or more, 750 cP or more, or even 1000 cP or more, when measured with a Brookfield DV-III viscometer using spindle SC-27 at 25° C.In embodiments, the low viscosity reactive diluent has a viscosity of 25 cP to 3000 cP, 25 cP to 2750 cP, 25 cP to 2500 cP, 25 cP to 2250 cP, 25 cP to 2000 cP, 25 cP to 1750 cP, 25 cP to 1500 cP, 25 cP to 1250 cP, 25 cP to 3000 cP, 25 cP to 2750 cP, 25 cP to 2500 cP, 25 cP to 2250 cP, 25 cP to 2000 cP, 25 cP to 1750 cP, , 25cP to 1500cP, 25cP to 1250cP, 50cP to 3000cP, 50cP to 2750cP, 50cP to 2500cP, 50cP to 2250cP, 50cP to 2000cP, 50cP to 1750cP, 50cP to 1500cP, 50cP to 1250cP, 100cP to 3000cP, 100cP to 2750cP, 100cP to 2500cP, 100cP to 2250cP, 100cP to 2000cP, 100cP to 1750cP, 100cP to 1500cP, 100cP to 1250cP, 250cP to 3000cP, 250cP to 2750cP, 250cP to 2500cP, 250cP to 2250cP, 250cP to 2000cP, 250cP to 1750cP, 250cP to 1500cP, 250cP to 1250cP, 500cP to 3000cP, 500cP to 2750cP, 500cP to 2500cP, 500cP to 2250cP, 500cP to 2000cP, 500cP to 1750cP, 500cP to 1500cP, 500cP to 1250cP, 750cP to 3000cP, 750cP to 2750cP, 7 The viscosity may be from 50 cP to 2500 cP, from 750 cP to 2250 cP, from 750 cP to 2000 cP, from 750 cP to 1750 cP, from 750 cP to 1500 cP, from 750 cP to 1250 cP, from 1000 cP to 3000 cP, from 1000 cP to 2750 cP, from 1000 cP to 2500 cP, from 1000 cP to 2250 cP, from 1000 cP to 2000 cP, from 1000 cP to 1750 cP, from 1000 cP to 1500 cP, or even from 1000 cP to 1250 cP, or any and all subranges formed from any of these endpoints.

[0142] The low-viscosity reactive diluent may comprise at least one radically polymerizable diluent. The low-viscosity reactive diluent may comprise a mixture of radically polymerizable diluents. When the low-viscosity reactive diluent comprises a mixture of radically polymerizable diluents, the viscosity requirements apply to the mixture of radically polymerizable diluents. Thus, the mixture may comprise a radically polymerizable diluent having a viscosity of more than 3000 cP at 25°C, as long as the final mixture of radically polymerizable diluents has a viscosity of 3000 cP or less at 25°C, as measured according to the method defined above.

[0143] As used herein, a radically polymerizable diluent is a compound having at least one polymerizable carbon-carbon double bond and an appropriate viscosity as defined above. The polymerizable carbon-carbon double bond is capable of participating in free radical polymerization, in which at least one of the carbon atoms of the double bond is covalently bonded to another atom, particularly a carbon atom, in a second molecule. In particular, the low-viscosity reactive diluent may include at least one radically polymerizable diluent selected from (meth)acrylates, vinyl ethers, vinyl amides, vinyloxazolidinones, and combinations thereof. These diluents may be monofunctional (i.e., having a single polymerizable carbon-carbon double bond) or polyfunctional (i.e., having at least two polymerizable carbon-carbon double bonds). These diluents may be selected to provide the targeted final properties of the cured formulation, as long as they provide an appropriate viscosity reduction of the oligomer while also producing the appropriate properties when the curable composition is cured.

[0144] The low-viscosity reactive diluent may include a monofunctional (meth)acrylate (i.e., a monomer having a single (meth)acrylate group). Examples of suitable monofunctional (meth)acrylates include mono(meth)acrylate esters of aliphatic alcohols (wherein the aliphatic alcohol may be linear, branched, or alicyclic, and may be a monoalcohol, dialcohol, or polyalcohol, provided that only one hydroxyl group is esterified with (meth)acrylic acid); mono(meth)acrylate esters of aromatic alcohols (such as phenol, including alkylated phenol); mono(meth)acrylate esters of alkylaryl alcohols (such as benzyl alcohol); oligomeric and polymeric glycols (such as diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol, and polypropylene glycol). mono(meth)acrylate esters of monoalkyl ethers of glycols and oligoglycols; mono(meth)acrylate esters of alkoxylated (e.g., ethoxylated and / or propoxylated) fatty alcohols (wherein the fatty alcohol may be linear, branched, or alicyclic and may be a monoalcohol, dialcohol, or polyalcohol, provided that only one hydroxyl group of the alkoxylated fatty alcohol is esterified with (meth)acrylic acid); mono(meth)acrylate esters of alkoxylated (e.g., ethoxylated and / or propoxylated) aromatic alcohols (such as alkoxylated phenols); caprolactone mono(meth)acrylate, and the like.The following compounds are specific examples of mono(meth)acrylate functionalized monomers suitable for use: methyl (meth)acrylate; ethyl (meth)acrylate; n-propyl (meth)acrylate; n-butyl (meth)acrylate; isobutyl (meth)acrylate; n-hexyl (meth)acrylate; 2-ethylhexyl (meth)acrylate; n-octyl (meth)acrylate; isooctyl (meth)acrylate; n-decyl (meth)acrylate; n-dodecyl (meth)acrylate; tridecyl (meth)acrylate; tetradecyl (meth)acrylate. Ladecyl (meth)acrylate;Hexadecyl (meth)acrylate;2-Hydroxyethyl (meth)acrylate;2- and 3-Hydroxypropyl (meth)acrylate;2-Methoxyethyl (meth)acrylate;2-Ethoxyethyl (meth)acrylate;2- and 3-Ethoxypropyl (meth)acrylate;Tetrahydrofurfuryl (meth)acrylate;Alkoxylated tetrahydrofurfuryl (meth)acrylate;2-(2-Ethoxyethoxy)ethyl (meth)acrylate;Cyclohexyl (meth)acrylate; Glycidyl (meth)acrylate;Isodecyl (meth)acrylate;Lauryl (meth)acrylate;2-Phenoxyethyl (meth)acrylate;Alkoxylated phenol (meth)acrylate;Alkoxylated nonylphenol (meth)acrylate;Cyclic trimethylolpropane formal (meth)acrylate;Isobornyl (meth)acrylate;Tricyclodecanemethanol (meth)acrylate;tert-Butylcyclohexanol (meth)acrylate;Trimethylcyclohexanol (meth)acrylate;Di Ethylene glycol monomethyl ether (meth)acrylate; diethylene glycol monoethyl ether (meth)acrylate; diethylene glycol monobutyl ether (meth)acrylate; triethylene glycol monoethyl ether (meth)acrylate; ethoxylated lauryl (meth)acrylate; methoxypolyethylene glycol (meth)acrylate; hydroxyethyl-butyl urethane (meth)acrylate; 3-(2-hydroxyalkyl)oxazolidinone (meth)acrylate; and combinations thereof.

[0145] Preferably, the low-viscosity reactive diluent may comprise a monofunctional (meth)acrylate having one or more of the following groups: a ring or ring system (i.e., one or more rings selected from aromatic rings and / or (hetero)alicyclic rings, which may be fused and / or bridged), a C7-C20 hydrocarbon chain (i.e., a straight or branched chain containing only carbon and hydrogen atoms, the number of carbon atoms in the chain being from 7 to 20), one or more oxyalkylene units (such as oxyethylene, oxypropylene and / or oxybutylene units), one or more ester units derived from the ring opening of a lactone (such as ε-caprolactone), and combinations thereof. Examples of such monofunctional (meth)acrylates are isobornyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, phenol (meth)acrylate, nonylphenol (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate; lauryl (meth)acrylate; tridecyl (meth)acrylate, stearyl (meth)acrylate, (poly)caprolactone mono(meth)acrylate, di-, tri-, tetra- or polyethylene glycol mono(meth)acrylate, di-, tri-, tetra- or polyethylene glycol monomethyl ether (meth)acrylate, di-, tri-, tetra- or polyethylene glycol monoethyl ether (meth)acrylate, and alkoxylated (i.e., ethoxylated and / or propoxylated) derivatives thereof, and combinations thereof.

[0146] The low viscosity reactive diluent may be a polyfunctional (meth)acrylate (i.e., a monomer having at least two (meth)acrylate groups), such as bisphenol A di(meth)acrylate; hydrogenated bisphenol A di(meth)acrylate; ethylene glycol di(meth)acrylate; diethylene glycol di(meth)acrylate; triethylene glycol di(meth)acrylate; tetraethylene glycol di(meth)acrylate; polyethylene glycol di(meth)acrylate; propylene glycol di(meth)acrylate; dipropylene glycol COLE DI(METH)ACRYLATE;TRIPROPYLENE GLYCOL DI(METH)ACRYLATE;TETRAPROPYLENE GLYCOL DI(METH)ACRYLATE;POLYPROPYLENE GLYCOL DI(METH)ACRYLATE;POLYTETRAMETHYLENE GLYCOL DI(METH)ACRYLATE;1,2-BUTANEDIOL DI(METH)ACRYLATE;2,3-BUTANEDIOL DI(METH)ACRYLATE;1,3-BUTANEDIOL DI(METH)ACRYLATE;1,4-BUTANEDIOL DI(METH)ACRYLATE;1,5-PENTANEDIOL DI(METH)ACRYLATE;1,6-HEXANEDIOL DI(METH)ACRYLATE acrylate;1,8-octanediol di(meth)acrylate;1,9-nonanediol di(meth)acrylate;1,10-nonanediol di(meth)acrylate;1,12-dodecanediol di(meth)acrylate;neopentyl glycol di(meth)acrylate;2-methyl-2,4-pentanediol di(meth)acrylate;Polybutadiene di(meth)acrylate;Cyclohexane-1,4-dimethanol di(meth)acrylate;Tricyclodecane dimethanol di(meth)acrylate;Metal di(meth)acrylates;Modified metal di(meth)acrylates tetra(meth)acrylate;Glyceryl di(meth)acrylate;Glyceryl tri(meth)acrylate;Trimethylolethane tri(meth)acrylate;Trimethylolethane di(meth)acrylate;Trimethylolpropane tri(meth)acrylate;Trimethylolpropane di(meth)acrylate;Pentaerythritol di(meth)acrylate;Pentaerythritol tri(meth)acrylate;Pentaerythritol tetra(meth)acrylate,Di(trimethylolpropane)diacrylate;Di(trimethylolpropane)triacrylate;Di(trimethylolpropane) tetraacrylate, sorbitol penta(meth)acrylate; di(pentaerythritol) tetraacrylate; di(pentaerythritol) pentaacrylate; di(pentaerythritol) hexa(meth)acrylate; tris(2-hydroxyethyl) isocyanurate tri(meth)acrylate; and alkoxylated (e.g., ethoxylated and / or propoxylated) derivatives thereof; and combinations thereof.

[0147] Low viscosity reactive diluents may include vinyl ethers such as dodecyl vinyl ether, hydroxybutyl vinyl ether, cyclohexanedimethylol divinyl ether, and DVE-3 (triethylene glycol divinyl ether) and combinations thereof.

[0148] Low viscosity reactive diluents may include vinyl amides such as N-vinylpyrrolidone (NVP), N-vinylcaprolactam (V-CAP), and combinations thereof.

[0149] The low viscosity reactive diluent may include a vinyloxazolidinone such as vinylmethyloxazolidinone (VMOX).

[0150] In a preferred embodiment, the low viscosity reactive diluent preferably comprises a monofunctional (meth)acrylate or a mixture of a monofunctional (meth)acrylate and a multifunctional (meth)acrylate.

[0151] In embodiments, the low-viscosity reactive diluent may include a low-viscosity (meth)acrylate monomer. For example, the low-viscosity reactive diluent may include isodecyl acrylate, alkoxylated tetrahydrofurfuryl acrylate, di-trimethylolpropane tetraacrylate, octyl acrylate, isodecyl acrylate, decyl acrylate, PEG mono(meth)acrylate, isooctyl acrylate, caprolactone acrylate, tridecyl acrylate, alkoxylated neopentyl glycol diacrylate, alkoxylated lauryl acrylate, alkoxylated phenol acrylate, tridecyl methacrylate, lauryl acrylate, ethoxylated nonylphenol acrylate, ethoxylated phenol acrylate, glycerol methacrylate, isobornyl acrylate, isobornyl methacrylate, or a combination thereof.

[0152] The amount of low-viscosity reactive diluent in the curable composition varies depending on the desired viscosity. In embodiments, the curable composition may comprise 20% to 80% by weight of low-viscosity reactive diluent, based on the weight of the curable composition. In embodiments, the curable composition may comprise 20% or more, 25% or more, 30% or more, 35% or more, or 40% or more by weight of low-viscosity reactive diluent, based on the weight of the curable composition. In embodiments, the curable composition may comprise 80% or less, 75% or less, 70% or less, 65% or less, or even 60% or less by weight of low-viscosity reactive diluent, based on the weight of the curable composition. In embodiments, the amount by weight of the low viscosity reactive diluent in the curable composition is from 20% to 80%, from 20% to 75%, from 20% to 70%, from 20% to 75%, from 20% to 60%, from 25% to 80%, from 20% to 75%, from 25% to 70%, from 25% to 75%, from 25% to 60%, from 30% to 80%, from 30% to 75%, from 30% to 75%, from 30% to 80 ...75%, from 30% to 75%, from 30% to 80%, from 30 It can be 0% to 70%, 30% to 75%, 30% to 60%, 35% to 80%, 35% to 75%, 35% to 70%, 35% to 75%, 35% to 60%, 40% to 80%, 40% to 75%, 40% to 70%, 40% to 75%, or even 40% to 60%, or any and all subranges formed from any of these endpoints.

[0153] In preferred embodiments, the curable composition may comprise at least 6%, at least 10%, or at least 15% by weight of the multifunctional (meth)acrylate monomer as defined above, based on the total weight of the curable composition. Alternatively, the curable composition may comprise less than 6%, less than 5%, less than 4%, less than 3%, less than 2%, less than 1%, or even 0% by weight of the multifunctional (meth)acrylate monomer as defined above, based on the total weight of the curable composition.

[0154] In embodiments, the weight ratio of oligomer to low viscosity reactive diluent in the curable composition can be from 4:1 to 1:4, e.g., from 3:1 to 1:4, from 2:1 to 1:4, from 1:1 to 1:4, from 3:1 to 1:3, from 2:1 to 1:3, from 1:1 to 1:3, from 3:1 to 1:2, from 2:1 to 1:2, from 1:1 to 1:2, from 3:1 to 1:1, or even from 2:1 to 1:1, or any and all subranges formed from any of these endpoints.

[0155] [Curable composition] In embodiments, the curable composition has a glass transition temperature T when cured of about 20° C. or less, or about 10° C. or less when cured. g In embodiments, the curable composition may be liquid at a temperature of 25° C.±2° C. In embodiments, the curable composition may have a viscosity of 50,000 cP or less, e.g., 45,000 cP or less, 40,000 cP or less, 35,000 cP or less, 30,000 cP or less, 25,000 cP or less, 20,000 cP or less, 15,000 cP or less, 12,500 cP or less, or even 10,000 cP or less, as measured with a Brookfield DV-III viscometer using spindle SC-27 at 60° C. Such viscosity characteristics facilitate spreading the composition onto a substrate for film formation.

[0156] In a preferred embodiment, the curable composition may have a viscosity of 50,000 cP or less, e.g., 45,000 cP or less, 40,000 cP or less, 35,000 cP or less, 30,000 cP or less, 25,000 cP or less, 20,000 cP or less, 15,000 cP or less, 12,500 cP or less, or 10,000 cP or less, as measured with a Brookfield DV-III viscometer using spindle SC-27 at 25°C.

[0157] In embodiments, the curable composition may contain less than 1 wt. % solvent and less than 1 wt. % water, or no solvent and no water, hi embodiments, the curable composition may be cured to form a film or coating.

[0158] [Method for preparing and curing a curable composition] The present invention also relates to a method for preparing the curable composition according to the present invention, the method comprising the following steps: - preparing an oligomer according to the invention dissolved in a non-reactive solvent; - adding a reactive diluent to obtain a diluted curable composition; - removing at least a portion of the non-reactive solvent from the diluted curable composition to obtain the curable composition according to the invention. Includes.

[0159] The oligomer dissolved in the non-reactive solvent can be prepared by solution polymerization as described above. The oligomer, non-reactive solvent, and reactive diluent can be as defined above. The non-reactive solvent can be at least partially removed by heating the diluted curable composition, for example, at a temperature of 40°C or higher, particularly 50°C or higher, and more particularly 60°C or higher. The amount of non-reactive solvent after the removal step can be less than 1%, less than 0.5%, or even 0% by weight of the non-reactive solvent, based on the weight of the curable composition.

[0160] The present invention also relates to a method for curing the curable composition according to the present invention. The method for curing the curable composition comprises curing the curable composition.

[0161] The curing process can be carried out at ambient temperature (ie, 10-30°C).

[0162] The curing step can be carried out by irradiating the composition with a light source having a wavelength and / or intensity capable of activating the polymerized chromophore monomer units of the oligomer of the present invention and causing crosslinking of the oligomer and / or the reactive diluent. The curing step can be carried out in the absence of photoinitiators other than the oligomer of the present invention. In other words, the curable composition can contain less than 0.1% by weight, particularly less than 0.05%, more particularly less than 0.001%, and even more particularly 0% by weight of photoinitiators other than the oligomer of the present invention, based on the weight of the curable composition.

[0163] The method for curing the curable composition of the present invention may not include a pre-cure step, particularly a step of curing at least a portion of the reactive diluent prior to crosslinking the oligomer of the present invention, for example, by irradiating the curable composition with a long-wavelength and / or low-intensity light source in the presence of a photoinitiator other than the oligomer of the present invention. As used herein, a long-wavelength and / or low-intensity light source is a light source that cannot activate the polymerized chromophore monomer units of the oligomer of the present invention and cause crosslinking of the oligomer and / or the reactive diluent. An example of a long-wavelength and / or low-intensity light source is a black light (as opposed to a mercury lamp, which can activate chromophores containing benzophenone moieties, or an LED-UV lamp, which can activate chromophores containing thioxanthone moieties). Preferably, the method for curing the curable composition of the present invention includes a curing step of simultaneously curing at least a portion of the reactive diluent and at least a portion of the oligomer of the present invention. Without being bound by theory, it is believed that such a curing method allows at least a portion of the reactive diluent to be grafted onto at least a portion of the oligomer of the present invention.

[0164] [Method of coating substrate] The present invention also relates to a method of coating a substrate.

[0165] In embodiments, a method of coating a substrate can include applying a curable composition to a substrate and curing the curable composition. Preferably, the step of applying the curable composition is carried out at ambient temperature (i.e., 10-30°C). In other words, the curable composition does not need to be heated before being applied to the substrate. In embodiments, the substrate can be a high surface energy substrate, such as a metal, or a low surface energy substrate, such as a plastic. The substrate can be any commercially important substrate, such as a high surface energy substrate or a low surface energy substrate, such as a metal substrate or a plastic substrate, respectively. The substrate can include stainless steel, paper, cardboard, glass, polyolefin, PET, PVC, PMMA, PC, composites, and wood.

[0166] In embodiments, the curable composition can be applied to a substrate by spraying, knife coating, roller coating, casting, drum coating, dipping, or the like, and combinations thereof. Curing can be carried out as described above for methods of curing the curable compositions of the present invention. In embodiments, curing can include curing by exposure to one of the group consisting of visible radiation, UV radiation, LED radiation, laser radiation, electron beam radiation, peroxides, accelerators, and heat. In embodiments, curing includes a combination of these curing techniques. More particularly, the curable composition can be fully cured by exposing the composition to ultraviolet (UV) radiation. UV-curable compositions can advantageously be cured by exposing the composition to an LED light source.

[0167] [glue] In embodiments, pressure-sensitive adhesives can be made or prepared from the curable compositions described herein. In embodiments, cured products can be made or prepared from the curable compositions described herein. In embodiments, the curable compositions described herein can be used in adhesives, particularly pressure-sensitive adhesives.

[0168] Embodiments of the curable compositions described herein can be used as adhesive tapes, adhesive sheets, adhesive sprays, product packaging, product labels, construction products, or medical products, and more particularly, the pressure-sensitive adhesives are used in packaging, labeling, construction, model making, medical, and construction applications.

[0169] [Additives] In embodiments, the curable composition may further comprise 0.1 wt % to 40 wt % of at least one tackifying resin. In embodiments, the at least one tackifying resin may have a softening temperature of 20° C. or less. In embodiments, the at least one tackifying resin may be selected from the group consisting of piperylene-based hydrocarbon resins, which may be hydrogenated, and hydrogenated or non-hydrogenated rosin esters modified with maleic anhydride rosin esters.

[0170] The PSA system may also optionally include other additives, such as additives selected from the group consisting of wetting agents, adhesion promoters, fillers, rheology modifiers, thixotropic agents, plasticizers, UV absorbers, UV stabilizers, dispersants, antioxidants, antistatic agents, lubricants, opacifying agents, defoamers, rheology agents, and the like, and combinations thereof.

[0171] In a preferred embodiment, the curable composition may be substantially free of photoinitiators other than the oligomers of the present invention, in particular, the curable composition may contain less than 0.1%, in particular less than 0.05%, more particularly less than 0.001%, and even more particularly 0% by weight of photoinitiators other than the oligomers of the present invention.

[0172] Although embodiments have been described in this specification so as to enable a clear and concise specification to be written, it is intended and will be understood that the embodiments may be combined or separated in various ways without departing from the invention. For example, it will be understood that all preferred features described herein are applicable to all aspects of the invention described herein.

[0173] Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various changes can be made in the details, within the scope and range of equivalents of the claims, without departing from the invention. [Example]

[0174] [material] The following materials were used in the examples: TIFF2025525559000013.tif161170

[0175] [method] [Molecular weight] The number average molecular weight (Mn) and weight average molecular weight (Mw) of the oligomers were determined using size exclusion chromatography (SEC) using poly(methyl methacrylate) reference standards and tetrahydrofuran as the solvent under the following conditions: - Columns: Agilent PLgel 5 micron 100A, 250 x 4.6 mm; Agilent PLgel 3 micron MiniMix E, 250 x 4.6 mm; Agilent PLgel 5 micron MiniMix D, 250 x 4.6 mm - Detector: Refractive index detector - Solvent flow rate: 0.45 μL / min - Temperature: 40℃ - Sample injection volume: 25 μL

[0176] Example 1: Curable composition containing an oligomer with polymerized benzophenone units Tables 2 and 3 below show the components (weight percent) used to form the oligomers and selected properties of Comparative Examples C1 through C6 and Examples E1 through E26.

[0177] Oligomers were obtained by solution polymerization of the monomers listed in Tables 2 and 3 using the amounts of MEK listed in Tables 2 and 3 as the solvent. The solvent and monomers were added to a 60 mL vial. A Vazo52 initiator solution in the solvent was prepared in a separate vial and then added to the monomer solution (total monomer:initiator weight ratio of 400:1). The vial was then placed in a 65°C water bath and gently shaken for 11 hours. Oligomers of various molecular weights can be prepared by adjusting the solvent type, solids content, reaction temperature, reaction time, and initiator:monomer ratio using experimental conditions familiar to those skilled in the art. Monomer:Vazo52 ratios between 100:1 and 1000:1 were typically used to produce relatively low molecular weight oligomers as described and used in subsequent examples.

[0178] Formulations for evaluating cure speed according to Method B below were made by adding the ingredients listed in Tables 2 and 3 to SR355 in a Flacktek® polypropylene cup and mixing until uniform using a Flacktek® DAC400.2VAC high speed mixer at 1500 rpm for 2 minutes.

[0179] Formulations for evaluating the peel strength of UV-curable pressure-sensitive adhesives (UV-PSAs) according to Method C below were made by adding the ingredients listed in Tables 2 and 3 to a 1:1 ratio of SR395 / SR611 such that the final concentration of oligomer to SR395 / SR611 after MEK evaporation was 2:1:1. The formulations were added to a Flacktek® polypropylene cup and mixed to uniformity for 2 minutes at 1500 rpm using a Flacktek® DAC400.2 VAC high-speed mixer. TIFF2025525559000014.tif219170TIFF2025525559000015.tif114170TIFF2025525559000016.tif229170TIFF2025525559000017.tif124170

[0180] The following methods were used to analyze the oligomers in this application. [Method A - Gel Content] The gel content of neat oligomers was measured by curing 3-mil wet coatings using an H-bulb (Mini Fusion LC6, 15 fpm, 3 passes). The drawdown thickness depended on the final MEK percentage in the oligomer. For example, if examples were provided as either 60% monomer and 40% MEK or 50% monomer and 50% MEK, the 40% MEK examples were drawn down from a 5-mil thickness, and the 50% MEK examples were drawn down from a 6-mil thickness, so that the film thickness after MEK evaporation was 3 mil. After drawdown, the glass slides were placed in a 60°C oven for 1 hour to remove the solvent. The samples were cured in air or nitrogen. After curing, the samples were removed from the glass slides and placed in MEK solution for 24 hours. The gel content was given as the percentage of the remaining weight of the sample after 24 hours of immersion in MEK compared to the sample's initial weight, as given by the following equation: TIFF2025525559000018.tif17170

[0181] 1, the environment (i.e., air (shown as gray bars) or nitrogen (shown as black bars)) had minimal effect on gel content. Example E6 (an oligomer containing 69.5 wt% BA, 26.5 wt% MMA, and 1 wt% BENZO) had a gel content of 67 wt% (air) and 79% (nitrogen). On the other hand, Comparative Example C2 (an oligomer containing 54.5 wt% BA, 44.5 wt% MMA, and 1 wt% BENZO) had a gel content of less than 5 wt% when cured in air and nitrogen. As illustrated in FIG. 1, the high T g As the monomer unit MMA increases, the gel content decreases. g Monomer units and polymerized low T g The amount of monomer units can be adjusted to achieve the desired amount of crosslinking, such as the gel content indicated.

[0182] Referring now to Figure 2, the gel content of Examples E8-E13, which are oligomers containing additional (synergist) monomer units, was comparable to that of Example E1, which is an oligomer without additional (synergist) monomer units. Without wishing to be bound by theory, the additional (synergist) monomer units may not have had a significant effect on gel content because the BENZO attached to the oligomer backbone was sufficient chromophore to fully crosslink the system, regardless of whether the additional (synergist) monomer units were present. Note that examples cured in air are shown with light gray bars, and examples cured in nitrogen are shown with dark gray bars.

[0183] 3, different M s of Example E1 are plotted against different BENZO loadings on the oligomer backbone and different environments (i.e., from left to right, for each BENZO loading: 10k MW air (light grey bars), 10k MW nitrogen (dark grey bars), 26k MW air (medium grey bars), 26k MW nitrogen (black bars)). w The gel content was measured for each version. The higher Mw versions of each oligomer had higher gel content. As the amount of BENZO was decreased, the gel content steadily decreased, indicating that fewer chromophores were available to crosslink the system, resulting in less crosslinked gel. As illustrated in Figure 3, sufficient gel content (e.g., greater than 50%) can be achieved even when the amount of BENZO is reduced to 0.5 wt%.

[0184] [Method B - Photodifferential Scanning Calorimetry (PhotoDSC)] The examples were mixed with SR355 in an initial weight ratio of oligomer:SR355, placed in a Tzero pan, and the residual solvent was evaporated in an oven. The initial weight ratio of oligomer:SR355 was chosen to result in a 1:1 weight ratio of oligomer:SR355 after the solvent was evaporated. The samples were then exposed to broad spectrum UV light (100 mW / cm 2 ) for 2 minutes.

[0185] Referring now to Figure 4, the cure rates (i.e., the time to reach a peak maximum) of the indicated examples were recorded (shown as gray bars in Figure 4). The heat flow area under each curve was measured, along with the maximum temperature reached during cure (shown as black bars in Figure 4). As illustrated in Figure 4, the cure rate increased with increasing amounts of MMA. Therefore, the amount of polymerized high Tg monomer units and polymerized low Tg monomer units in the oligomer can be adjusted to achieve the desired cure rate. Furthermore, Comparative Examples C2-C4 and Examples E1-E4, E6, and E7 all induced crosslinking with SR355. However, Comparative Examples C2-C4 did not induce crosslinking with itself.

[0186] Referring now to Figure 5, the cure rates of the indicated examples were recorded (indicated by the light gray bars in Figure 5). The heat flow area under each curve was measured, along with the maximum temperature reached during cure (indicated by the dark gray bars in Figure 5). Examples E8-E13, which are oligomers containing additional (synergist) monomer units, cured faster than Example E1, which is an oligomer without additional (synergist) monomer units. As illustrated in Figure 10, the incorporation of additional synergist monomer units into the oligomer increases the cure rate.

[0187] Referring now to Figure 6, the cure speeds of the 10k Mw version of Example E1 (shown by the gray bars) and the 26k Mw version of Example E1 (shown by the black bars) containing different amounts of BENZO were recorded. As the amount of BENZO decreased, the cure speed decreased. As illustrated in Figure 11, the amount of BENZO in the oligomer can be adjusted to achieve the desired cure speed.

[0188] [Method C - Peel strength of UV-curable pressure-sensitive adhesives (UV-PSA)] The examples were drawn down using two 50 μm tape guides to achieve a uniform film thickness. After drawdown, the films were placed in a 60°C oven for 1 hour to remove the MEK solvent from the film. After drying, the films were cured with a Fusion H bulb at 15 fpm three times to crosslink the oligomer and form the UV-PSA. One-inch strips were cut and the UV-PSA was laminated to a stainless steel substrate. The UV-PSA was aged for 24 hours in a constant temperature room before testing. 180° peel strength was measured using an Instron at 12 inches / minute according to ASTM D3330.

[0189] During the 180° peel test, the examples failed adhesively, not cohesively, meaning that the resulting peel strength is a measure of whether the example was completely removed from the stainless steel substrate (adhesive failure) or the result of chemical bond failure within the example (cohesive failure).

[0190] 7, Examples E8-E13, which are oligomers containing additional (synergistic) monomer units, exhibited peel strengths similar to Example E1, an oligomer without additional (synergistic) monomer units. As illustrated in FIG. 12, the inclusion of additional (synergistic) monomer units in the oligomer may not significantly affect peel strength. With regard to E9, without wishing to be bound by theory, the relatively high peel strength was attributed to over-crosslinking of the oligomer.

[0191] Here, in Figure 8, Examples E15, E16, and E21, which are oligomers containing acrylic acid, exhibited higher peel strengths compared to Example E1, which is an oligomer without acrylic acid. As illustrated in Figure 13, acrylic acid can be included in an oligomer to improve its peel strength.

[0192] Referring now to Figure 9, peel strength was measured for the 10k Mw version of Example E1 (shown as the grey bar) and the 26k Mw version of Example E1 (shown as the black bar) containing different amounts of BENZO. As shown, reducing the amount of BENZO to 0.25 wt% or 0.5 wt% increased peel strength. While not wishing to be bound by theory, the 1 wt% and 2 wt% BENZO examples exhibited reduced peel strength due to over-crosslinking of the oligomers. Peel strength decreased significantly when the BENZO amount was 0.25 wt% or less. For the examples containing 0.25 wt% BENZO, peel strength increased to 10k Mw. w It was 0.5lbF at 26k M w Note that the gel content was greater than 2 lbF for the 10k Mw example, compared to less than 20% for the 26k Mw example with 0.25% BENZO. As illustrated in Figure 14, the M of the oligomer w The peel strength of the oligomers was affected by less than 0.5 wt% BENZO, but a larger effect was observed with different amounts of BENZO.

[0193] Example 2: Oligomers with polymerized thioxanthone units Oligomers consisting of butyl acrylate, acrylic acid, and acrylated thioxanthone in a weight ratio of 94.9 / 5 / 0.1 were synthesized using 50 wt% ethyl acetate as the solvent using the general solution polymerization process described in Example 1. The acrylated thioxanthone was TX1 or TX2, having the structure shown below. TIFF2025525559000019.tif55170

[0194] The ethyl acetate solution of the oligomer was coated onto a 50 micron PET backing, and the solvent was removed at 60°C for 1 hour to produce a PSA film approximately 56-80 microns thick. The dried film was UV cured using a Phoseon 8W 395nm LED curing unit with three passes at a line speed of 50 fpm. The backed PSAs were tested for 180° peel strength according to the method described in ASTM D3330 and shear strength according to the method described in ASTM D3654 at room temperature (20-25°C). Both the peel and shear failure modes were cohesive. The data are summarized in the table below: TIFF2025525559000020.tif33170

[0195] The data show that oligomers with pendant thioxanthone groups can be used as base resins for UV-curable pressure-sensitive adhesives. When the oligomers are combined with SR355 in a 1:1 weight ratio, a curable composition according to the present invention can be obtained.

[0196] Example 3: Oligomers with polymerized thioxanthone units An oligomer consisting of butyl acrylate, acrylic acid, and acrylated thioxanthone in a weight ratio of 94.9 / 5 / 0.1 was synthesized in 60 wt% toluene using the general solution polymerization process described in Example 1. Acrylated thioxanthone TX2 has the structure shown in Example 2. The oligomer has an M of 27557 g / mol. n value, M of 154918 g / mol w , showing a Tg of XXXX°C.

[0197] A 0.05 mm thick PET film backing was cut from a roll into a 152 mm x 305 mm piece, and one edge was taped to a 152 mm x 305 mm x 0.63 mm aluminum panel. The PET film supported on the aluminum panel was secured in an MTI (Richmond, CA) Automatic Film Applicator-MSK-AFA-II. The oligomer solution in toluene was applied to the PET film by the drawdown method using a 0.25 mm bar film applicator. The prepared coating with the PET backing and aluminum panel support was allowed to dry in a laboratory hood for 30 minutes and further dried in a 60°C oven. The coating was then exposed to H-bulb UV energy from a Fusion conveyor system at a belt speed of 16 ft / min. Sample coatings were made four passes and ultimately received the energy shown in the following table: TIFF2025525559000021.tif34170

[0198] A release membrane was placed on top of the coated PET film backing as a temporary protective layer and cut into 25 mm (1 inch) strips using a paper cutter. The coating thickness was measured using a vernier caliper to be 0.038 (+ / - 0.012) mm. Each 25 mm wide strip (tape) was applied to a 50 mm x 125 mm stainless steel panel (ChemInstruments). The coated 25 mm tape samples were applied lengthwise to the steel panel using a mechanical 2 kg ChemInstruments roller to ensure consistent and reproducible pressure during application. The assembled samples were conditioned at 25°C / 50% relative humidity for 24 hours.

[0199] The following method was used for oligomer analysis. [180° Peel and Static Shear Strength Test Method] For 180° peel strength testing, an Instron Model #5433 physical testing machine equipped with pneumatic rubber pad grips with an X-kN load cell was used. Testing was based on ASTM D3330. The crosshead speed was set at 0.5 cm / min at ambient laboratory conditions. Adhesion strength values were measured and reported in pounds-force per inch (lbf / in). Coefficient of variation (CV) and standard deviation (SD) were also reported.

[0200] Shear samples were drawn down in the same manner as above, exposed to H-bulb UV energy, cut into 25 mm (1 in) strips, and adhered to 51 mm x 76 mm stainless steel panels. Samples were tested according to ASTM D3654 using a 1 kg load at ambient laboratory conditions (20-25°C).

[0201] H-bulb (only) 180° peel data and failure mode: TIFF2025525559000022.tif24170H Valve (only) Static Shear Data TIFF2025525559000023.tif19170

[0202] The data demonstrate that oligomers with pendant thioxanthone groups can be used as base resins for UV-curable pressure-sensitive adhesives. When the oligomers are combined with SR355 in a 1:1 weight ratio, a curable composition according to the present invention can be obtained.

[0203] [Aspect] Further aspects of the invention are provided by the subject matter of the following paragraphs: Item 1: 1% to 80% by weight of polymerized high T based on the total weight of the oligomer g Monomer units having a glass transition temperature (T g a high T selected from (meth)acrylate monomers having g Monomer units: 10% to 98.9% by weight of polymerized low T g Monomer units with a T of 25°C or less g a low T selected from monovalent (meth)acrylate monomers havingg an oligomer comprising: monomer units; 0.1% to 40% by weight of polymerized chromophore monomer units selected from (meth)acrylate monomers having pendant Norrish Type II chromophores; and 0% to 20% by weight of at least one polymerized additional monomer unit; and a low viscosity reactive diluent having a viscosity of 3000 cP or less at 25°C, wherein the oligomer has a weight average molecular weight of at least 10,000 grams / mole (g / mol); and wherein the oligomer has a T of -10°C or less. g wherein the curable composition has a viscosity of 50,000 cP or less at 60°C, preferably 50,000 cP or less at 25°C.

[0204] Item 2. The curable composition of the preceding item, wherein the weight ratio of oligomer to low viscosity reactive diluent is 4:1 to 1:4.

[0205] Item 3. The curable composition of any of the preceding items, comprising 20% to 80% by weight of the oligomer and 20% to 80% by weight of the low-viscosity reactive diluent, based on the weight of the curable composition.

[0206] Item 4. The oligomer contains, based on the total weight of the oligomer, 1% to 50% by weight, especially 3% to 44% polymerized high T g Monomer units; 50% to 97% by weight, especially 55% to 95% polymerized low T g Monomer units; 0.1% to 10%, especially 0.1% to 2%, by weight of polymerized chromophore monomer units; 0 to 5% by weight of additional polymerized monomer units 10. The curable composition according to any one of the preceding items, comprising:

[0207] Item 5. The curable composition according to any of the preceding items, wherein the oligomer has a weight average molecular weight of 10,000 g / mol to 600,000 g / mol, particularly 10,000 g / mol to 100,000 g / mol, more particularly 10,000 g / mol to 50,000 g / mol, even more particularly 11,000 g / mol to 49,000 g / mol, more particularly still 12,000 g / mol to 48,000 g / mol, still more particularly 15,000 g / mol to 45,000 g / mol, and even more particularly 15,000 g / mol to 40,000 g / mol.

[0208] Section 6: Low T in oligomers g Monomer units and high T g 10. The curable composition according to any one of the preceding items, wherein the weight ratio of the monomer units is from 24:1 to 1.5:1.

[0209] Section 7 High T g Monomer unit T g Low T g Monomer unit T g 10. The curable composition according to any of the preceding items, wherein the temperature is at least 20°C higher than

[0210] Section 8 High T g Each of the monomer units has the formula (I): TIFF2025525559000024.tif48170(in the above formula, A 1 is H, (C1-C 30 ) hydrocarbyl or (C-C 30 ) heterohydrocarbyl, preferably H or (C-C 30 ) hydrocarbyl; and Z 1 is —H or —CH3).

[0211] Item 9. High T of oligomers gThe monomer units are (meth)acrylic acid, 2-phenylethyl methacrylate, 3,3,5-trimethylcyclohexyl acrylate, tert-butyl acrylate, octadecyl methacrylate, octadecyl acrylate, propyl methacrylate, benzyl methacrylate, isobutyl methacrylate, ethyl methacrylate, 2,2,3,3-tetrafluoropropyl methacrylate, 2,2,2-trifluoroethyl methacrylate, isopropyl methacrylate, isobornyl acrylate, methyl methacrylate, isobornyl methacrylate, phenyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, 4-tert-butylcyclohexyl acrylate, 4-tert-butylcyclohexyl methacrylate, 3,3,5-trimethylcyclohexyl acrylate, 3,3,5-trimethylcyclohexyl methacrylate, substituted or unsubstituted (C6-C 12 2. The curable composition according to any one of the preceding paragraphs, wherein the acrylate is selected from the group consisting of cycloalkyl(meth)acrylate, adamantyl(meth)acrylate, tricyclodecanemethanol mono(meth)acrylate, and combinations thereof.

[0212] Item 10 High T of oligomers g Item 10. The curable composition of any of the preceding items, wherein the monomer units are selected from methyl methacrylate, tert-butyl (meth)acrylate, (meth)acrylic acid, isobornyl (meth)acrylate, or a combination thereof.

[0213] Section 11 Low T g Each of the monomer units has the formula (II): TIFF2025525559000025.tif47170 (in the above formula, A 2 is (C2-C 30 ) hydrocarbyl or (C-C 30 ) heterohydrocarbyl, preferably (C4-C 30 ) hydrocarbyl; and Z 2 is —H or —CH3).

[0214] Item 12 Low T of oligomers g Item 10. The curable composition of any of the preceding items, wherein the monomer units are selected from n-butyl (meth)acrylate, isobutyl acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, isodecyl (meth)acrylate, tridecyl (meth)acrylate, lauryl (meth)acrylate, nonyl acrylate, decyl (meth)acrylate, octyl (meth)acrylate, propyl acrylate, isobutyl acrylate, 2,2,3,3-tetrafluoropropyl acrylate, ethyl acrylate, sec-butyl acrylate, dodecyl acrylate, tetradecyl (meth)acrylate, isopropyl acrylate, pentyl (meth)acrylate, benzyl acrylate, cyclohexyl acrylate, hexadecyl (meth)acrylate, 2-methylbutyl acrylate, 2-octyl acrylate, or a combination thereof.

[0215] Item 13. Each of the chromophore monomer units has formula (III): TIFF2025525559000026.tif42170 (A of formula (III) 3 is X or -LX, where L is (C1-C 10 ) a heterohydrocarbylene linker, X is a monovalent radical of a Norrish type II chromophore; and Z 3 is —H or —CH3).

[0216] Item 14. The curable composition of any preceding item, wherein each of the chromophore monomer units of the oligomer is a (meth)acrylate of a Norrish Type II photoinitiator.

[0217] Item 15. The curable composition of any preceding item, wherein the additional monomer units of the oligomer are selected from dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, N-vinylpyrrolidone, N-vinylcaprolactam, acryloylmorpholine, dimethylacrylamide, poly(ethylene oxide) mono(meth)acrylate, hydroxyethyl ethylene urea (meth)acrylate, reaction products of cyclic anhydrides and hydroxy-functional (meth)acrylates, and combinations thereof.

[0218] Item 16: The low-viscosity reactive diluent is a monofunctional (meth)acrylate monomer; in particular, a monofunctional (meth)acrylate having one or more of the following group: a ring or ring system, a C7-C20 hydrocarbon chain, one or more oxyalkylene units, one or more ester units derived from the ring opening of a lactone (such as ε-caprolactone), and combinations thereof; more particularly, isobornyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, phenol (meth)acrylate, nonylphenol (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, decyl (meth)acrylate, methyl ... Item 10. The curable composition according to any of the preceding items, comprising a monofunctional (meth)acrylate selected from the group consisting of (meth)acrylate, isodecyl (meth)acrylate; lauryl (meth)acrylate; tridecyl (meth)acrylate, stearyl (meth)acrylate, (poly)caprolactone mono(meth)acrylate, di-, tri-, tetra- or polyethylene glycol mono(meth)acrylate, di-, tri-, tetra- or polyethylene glycol monomethyl ether (meth)acrylate, di-, tri-, tetra- or polyethylene glycol monoethyl ether (meth)acrylate, and alkoxylated derivatives thereof, and combinations thereof.

[0219] Item 17: The low viscosity reactive diluent is a polyfunctional (meth)acrylate; in particular, bisphenol A di(meth)acrylate; hydrogenated bisphenol A di(meth)acrylate; ethylene glycol di(meth)acrylate; diethylene glycol di(meth)acrylate; triethylene glycol di(meth)acrylate; tetraethylene glycol di(meth)acrylate; polyethylene glycol di(meth)acrylate; propylene glycol di(meth)acrylate; dipropylene glycol di(meth)acrylate; tripropylene glycol Di(meth)acrylate;Tetrapropylene glycol di(meth)acrylate;Polypropylene glycol di(meth)acrylate;Polytetramethylene glycol di(meth)acrylate;1,2-Butanediol di(meth)acrylate;2,3-Butanediol di(meth)acrylate;1,3-Butanediol di(meth)acrylate;1,4-Butanediol di(meth)acrylate;1,5-Pentanediol di(meth)acrylate;1,6-Hexanediol di(meth)acrylate;1,8-Octanediol di (Meth)acrylates;1,9-Nonanediol di(meth)acrylate;1,10-Nonanediol di(meth)acrylate;1,12-Dodecanediol di(meth)acrylate;Neopentyl glycol di(meth)acrylate;2-Methyl-2,4-pentanediol di(meth)acrylate;Polybutadiene di(meth)acrylate;Cyclohexane-1,4-dimethanol di(meth)acrylate;Tricyclodecane dimethanol di(meth)acrylate;Metal di(meth)acrylates;Modified metal di(meth)acrylates; Glyceryl di(meth)acrylate;Glyceryl tri(meth)acrylate;Trimethylolethane tri(meth)acrylate;Trimethylolethane di(meth)acrylate;Trimethylolpropane tri(meth)acrylate;Trimethylolpropane di(meth)acrylate;Pentaerythritol di(meth)acrylate;Pentaerythritol tri(meth)acrylate;Pentaerythritol tetra(meth)acrylate,Di(trimethylolpropane)diacrylate;Di(trimethylolpropane)triacrylate;Item 10. The curable composition of any preceding item, comprising a multifunctional (meth)acrylate selected from di(trimethylolpropane)tetraacrylate, sorbitol penta(meth)acrylate; di(pentaerythritol)tetraacrylate; di(pentaerythritol)pentaacrylate; di(pentaerythritol)hexa(meth)acrylate; tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate; and alkoxylated (e.g., ethoxylated and / or propoxylated) derivatives thereof; and combinations thereof.

[0220] Item 18: Glass transition temperature T of approximately 20°C or less when cured g or is liquid at a temperature of 25°C ± 2°C.

[0221] Item 19. The curable composition of any preceding item, further comprising 0.1% to 40% by weight of at least one tackifying resin.

[0222] Item 20. The curable composition of any preceding item, wherein the at least one tackifying resin has a softening temperature of 20°C or less.

[0223] Item 21. The curable composition of any preceding item, wherein the at least one tackifying resin is selected from the group consisting of piperylene-based hydrocarbon resins, which may be hydrogenated, and which may be hydrogenated or non-hydrogenated rosin esters, modified with maleic anhydride rosin esters.

[0224] Item 22. The curable composition of any of the preceding items, which is a pressure-sensitive adhesive curable composition.

[0225] Item 23. A cured composition obtained by curing the curable composition according to any one of the preceding items.

[0226] Item 24. The cured composition of item 23, which is a pressure-sensitive adhesive in the form of an adhesive tape, adhesive sheet, adhesive spray, product packaging, product label, construction product, or medical product.

[0227] Item 25. The cured composition of paragraphs 23 or 24, for packaging, labeling, construction, model making, medical, and building applications.

[0228] Item 26. A pressure-sensitive adhesive produced using the curable composition of any one of items 1 to 22.

[0229] Item 27. A method of coating a substrate, comprising: applying the curable composition of any one of items 1 to 22 to the substrate; and curing the curable composition by exposure to UV radiation.

[0230] Item 28. The method of item 27, wherein the applying step includes applying by spraying, knife coating, roller coating, casting, drum coating, dipping, or a combination thereof.

[0231] Item 29. A method for preparing the curable composition of any one of items 1 to 22, comprising: - preparing the oligomer according to any one of paragraphs 1 and 4 to 15 by dissolving it in a non-reactive solvent; - adding a low viscosity reactive diluent to obtain a diluted curable composition; - removing at least a portion of the non-reactive solvent from the diluted curable composition to obtain the curable composition according to the invention. A method comprising:

[0232] Clause 30. A method of curing the curable composition of any one of clauses 1 through 22 or prepared by the method of clause 29, comprising curing the curable composition by irradiating the curable composition with a light source having a wavelength and / or intensity capable of activating polymerized chromophore monomer units of the oligomer and causing crosslinking of the oligomer and / or the reactive diluent.

[0233] It will be apparent to those skilled in the art that various modifications and changes can be made without departing from the scope of the present disclosure. Since modifications, combinations, subcombinations, and changes of the embodiments of the present disclosure that incorporate the spirit and content of the present disclosure may occur to those skilled in the art, the scope of the present disclosure should be interpreted as including all within the scope of the appended claims and equivalents thereof.

[0234] For purposes of defining the present technology, the transitional phrase "consisting of" may be introduced in a claim as a closed preamble limiting the scope of the claim to the recited components or steps and naturally occurring impurities. For purposes of defining the present technology, the transitional phrase "consisting essentially of" may be introduced in a claim to limit the scope of one or more claims to the recited elements, components, materials, or method steps, as well as unrecited elements, components, materials, or method steps that do not materially affect the novel properties of any claimed subject matter.

[0235] As used in the specification and the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. The verb "comprises" and its cognate forms should be construed to refer to elements, components, or steps in a non-exclusive manner. A referenced element, component, or step may be present in, utilized with, or combined with other elements, components, or steps not expressly referenced.

[0236] It should be understood that any two quantitative values assigned to a property may constitute a range for that property, and that all combinations of ranges formed from all recited quantitative values for a given property are contemplated by this disclosure. The subject matter disclosed herein has been described in detail and with reference to specific embodiments. It should be understood that any detailed description of an element or feature of an embodiment does not necessarily imply that the element or feature is essential to the particular embodiment or any other embodiment.

Claims

1. Based on the total weight of the oligomers, 1% to 80% by weight of polymerized high T ｇ Monomer units having a glass transition temperature (T ｇ a high T selected from (meth)acrylate monomers having ｇ Monomer units; 10% to 98.9% by weight of polymerized low T ｇ The monomer unit has a T of 25° C. or less. ｇ a low T selected from monovalent (meth)acrylate monomers having ｇ Monomer units; 0.1% to 40% by weight of polymerized chromophore monomer units selected from (meth)acrylate monomers having pendant Norrish Type II chromophores; and 0 to 20% by weight of at least one polymerized additional monomer unit and an oligomer comprising: a low viscosity reactive diluent having a viscosity of 3000 cP or less at 25°C; Including, the oligomer has a weight average molecular weight of at least 10,000 grams per mole (g / mol); The oligomer has a T of -10°C or less. ｇ have 1. A curable composition comprising: A curable composition having a viscosity of 50,000 cP or less at 60°C, preferably 50,000 cP or less at 25°C.

2. 10. The curable composition of claim 1, wherein the weight ratio of oligomer to low viscosity reactive diluent is from 4:1 to 1:

4.

3. The oligomers comprise, based on the total weight of the oligomers: 1% to 50%, especially 3% to 44%, by weight of polymerized high T ｇ Monomer units; 50% to 97%, especially 55% to 95%, by weight of polymerized low T ｇ Monomer units; 0.1% to 10%, especially 0.1% to 2%, by weight of polymerized chromophore monomer units; 0 to 5% by weight of additional polymerized monomer units The curable composition of claim 1 or claim 2, comprising:

4. 4. The curable composition according to claim 1, wherein the oligomer has a weight average molecular weight of from 10,000 g / mol to 600,000 g / mol, in particular from 10,000 g / mol to 100,000 g / mol, more particularly from 10,000 g / mol to 50,000 g / mol, even more particularly from 11,000 g / mol to 49,000 g / mol, more particularly still from 12,000 g / mol to 48,000 g / mol, also more particularly from 15,000 g / mol to 45,000 g / mol, and even more particularly from 15,000 g / mol to 40,000 g / mol.

5. Low T in oligomers ｇ Monomer units and high T ｇ 5. The curable composition of claim 1, wherein the weight ratio of the monomer units is from 24:1 to 1.5:

1.

6. High T ｇ Monomer unit T ｇ Low T ｇ Monomer unit T ｇ 6. The curable composition of claim 1, wherein the curing temperature is at least 20°C higher than the curing temperature of the curable composition of claim 1.

7. High T of oligomer ｇ The monomer units are (meth)acrylic acid, 2-phenylethyl methacrylate, 3,3,5-trimethylcyclohexyl acrylate, tert-butyl acrylate, octadecyl methacrylate, octadecyl acrylate, propyl methacrylate, benzyl methacrylate, isobutyl methacrylate, ethyl methacrylate, 2,2,3,3-tetrafluoropropyl methacrylate, 2,2,2-trifluoroethyl methacrylate, isopropyl methacrylate, isobornyl acrylate, methyl methacrylate, isobornyl methacrylate, phenyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, 4-tert-butylcyclohexyl acrylate, 4-tert-butylcyclohexyl methacrylate, 3,3,5-trimethylcyclohexyl acrylate, 3,3,5-trimethylcyclohexyl methacrylate, substituted or unsubstituted (C ６ -C １２ 7. The curable composition of claim 1, wherein the alkyl group is selected from the group consisting of cycloalkyl(meth)acrylate, adamantyl(meth)acrylate, tricyclodecanemethanol mono(meth)acrylate, and combinations thereof.

8. High T of oligomer ｇ The curable composition of claim 7, wherein the monomer units are selected from methyl methacrylate, tert-butyl (meth)acrylate, (meth)acrylic acid, isobornyl (meth)acrylate, or combinations thereof.

9. Low T of oligomer ｇ 9. The curable composition of claim 1, wherein the monomer units are selected from n-butyl (meth)acrylate, isobutyl acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, isodecyl (meth)acrylate, tridecyl (meth)acrylate, lauryl (meth)acrylate, nonyl acrylate, decyl (meth)acrylate, octyl (meth)acrylate, propyl acrylate, isobutyl acrylate, 2,2,3,3-tetrafluoropropyl acrylate, ethyl acrylate, sec-butyl acrylate, dodecyl acrylate, tetradecyl (meth)acrylate, isopropyl acrylate, pentyl (meth)acrylate, benzyl acrylate, cyclohexyl acrylate, hexadecyl (meth)acrylate, 2-methylbutyl acrylate, 2-octyl acrylate, or combinations thereof.

10. 10. The curable composition of claim 1, wherein each of the chromophore monomer units of the oligomer is a (meth)acrylate of a Norrish Type II photoinitiator.

11. 11. The curable composition of any one of claims 1 to 10, wherein the at least one additional polymerized monomer unit of the oligomer is selected from dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, N-vinylpyrrolidone, N-vinylcaprolactam, acryloylmorpholine, dimethylacrylamide, poly(ethylene oxide) mono(meth)acrylate, hydroxyethyl ethylene urea (meth)acrylate, reaction products of cyclic anhydrides and hydroxy-functional (meth)acrylates, and combinations thereof.

12. The low viscosity reactive diluent is a monofunctional (meth)acrylate; in particular, a monofunctional (meth)acrylate having one or more of the following group: a ring or ring system, a C7-C20 hydrocarbon chain, one or more oxyalkylene units, one or more ester units derived from the ring opening of a lactone (such as ε-caprolactone), and combinations thereof; more particularly, isobornyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, phenol (meth)acrylate, nonylphenol (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, decyl (meth)acrylate, 12. The curable composition of claim 1, comprising a monofunctional (meth)acrylate selected from the group consisting of acrylate, isodecyl (meth)acrylate; lauryl (meth)acrylate; tridecyl (meth)acrylate, stearyl (meth)acrylate, (poly)caprolactone mono(meth)acrylate, di-, tri-, tetra- or polyethylene glycol mono(meth)acrylate, di-, tri-, tetra- or polyethylene glycol monomethyl ether (meth)acrylate, di-, tri-, tetra- or polyethylene glycol monoethyl ether (meth)acrylate, and alkoxylated derivatives thereof, and combinations thereof.

13. The low-viscosity reactive diluent is preferably a polyfunctional (meth)acrylate; in particular, ethylene glycol di(meth)acrylate, di-, tri-, tetra- or polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, di-, tri-, tetra- or polypropylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, di-, tri-, tetra- or polybutylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate.

13. The curable composition of claim 1, comprising a multifunctional (meth)acrylate selected from the group consisting of 1,3-butylene glycol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, bisphenol A di(meth)acrylate, glycerol tri(meth)acrylate, di(trimethylolpropane)tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and alkoxylated (i.e., ethoxylated and / or propoxylated) derivatives thereof, and combinations thereof.

14. Upon curing, the glass transition temperature T ｇ or is liquid at a temperature of 25°C ± 2°C.

15. 15. The curable composition of claim 1, which is a pressure sensitive adhesive curable composition.

16. A method for preparing the curable composition of any one of claims 1 to 14, comprising the steps of: - preparing the oligomer according to any one of claims 1 and 3 to 11 by dissolving it in a non-reactive solvent; - adding a low viscosity reactive diluent to obtain a diluted curable composition; - removing at least a portion of the non-reactive solvent from the diluted curable composition to obtain the curable composition; A method comprising:

17. 17. A method of curing the curable composition of any one of claims 1 to 14 or prepared by the method of claim 16, comprising curing the curable composition by irradiating the curable composition with a light source having a wavelength and / or intensity capable of activating polymerized chromophore monomer units of an oligomer and causing crosslinking of the oligomer and / or the reactive diluent.

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