Branched Acrylate-Functional Oligomers

Abstract

The curable oligomer is the reaction product of x equivalents of at least one diepoxy a); y1 equivalents of at least one unsaturated carboxylic acid b); and y2 equivalents of at least one polycarboxylic acid c) containing at least three carboxylic acid groups, where x is defined as the number of moles of epoxy groups in component a), y1 is defined as the number of moles of carboxylic acid groups in component b), and y2 is defined as the number of moles of carboxylic acid groups in component c).

Description

[Technical field]

[0001] The present invention relates to curable acrylate-functional oligomers that contain branching and are suitable for actinic radiation curable compositions. The cured products made from such compositions can be used as coatings, inks, over-varnishes, adhesives, resins for additive manufacturing (e.g., 3D printing resins), molding resins, sealants, composites, antistatic layers, electronic applications, recyclable materials, smart materials that can detect and respond to stimuli, and biomedical materials. [Background technology]

[0002] Actinically curable compositions that provide uniform crosslinking, as well as improved toughness and gloss, are desirable. Also desirable are such compositions that, when cured, provide enhanced elasticity.

[0003] Other efforts to produce such materials are summarized below.

[0004] US Pat. No. 9,234,073 discloses copolymers obtainable by condensation of i) 90-99.5 mol % of succinic acid, based on components i)-ii); ii) 0.5-10 mol % of one or more C8-C20 dicarboxylic acids, based on components i-ii; and iii) 98-102 mol % of 1,3-propanediol or 1,4-butanediol, based on components i-ii.

[0005] U.S. Pat. No. 7,041,749 discloses oligomeric compositions formed from cycloaliphatic epoxides and Michael addition polyacrylate resins synthesized from multifunctional acrylates and β-dicarbonyl Michael donors, particularly β-ketoesters, β-diketones, β-ketoamides or β-ketoanilides, or combinations thereof.

[0006] US Pat. No. 5,891,960 discloses polymers that are the reaction products of (a) compounds that contain pendant and / or terminal hydroxyl or epoxy functional groups and (b) citric acid or anhydrous citric acid.

[0007] US Pat. No. 5,548,005 discloses aqueous radiation curable binders and binder dispersions containing (A) a radiation curable binder, and (B) a radiation curable hydrophilic polyepoxy-acrylate.

[0008] No. 5,196,485 discloses a composition comprising a polyepoxide component having an epoxy equivalent weight on resin solids of less than about 600. The composition further comprises a polyacid hardener having an average acid functionality of greater than 2.

[0009] U.S. Pat. No. 5,171,763 discloses a method for producing a compound of formula TIFF2024536248000001.tif23170[In the formula, each R 1 may be the same or different and each represents a hydrogen atom or a methyl group; R 2 discloses a hardenable composition for dental restorations, comprising a vinyl monomer containing 30% by weight or more of an acid group-containing vinyl monomer represented by the formula: [representing a trivalent to hexavalent organic residue having 1 to 30 carbon atoms, the residue may have an ether linkage and / or an ester linkage, m is an integer of 2 to 4, and n is an integer of 1 or 2], an ion-dissolving filler that dissolves polyvalent metal ions, and a polymerization initiator.

[0010] US Patent Application No. 2016 / 0256363 discloses dental composites including non-bisphenol-based epoxy acrylate oligomers.

[0011] U.S. Patent Application No. 2014 / 0336302 discloses a water soluble epoxy acrylate resin composition comprising the reaction product of (a) at least one diepoxide resin; (b) at least one carboxylic acid; and (c) at least one basic reagent in an amount sufficient to form a water soluble epoxy acrylate resin product.

[0012] U.S. Patent Application No. 2008 / 0206471 discloses a coating composition having excellent storage stability and curability, comprising a compound containing a carboxyl group and / or a cyclic acid anhydride group; a polyepoxide; and a latent curing catalyst composed of a tertiary amine and an acidic phosphoric acid ester.

[0013] EP 2350162 B1 discloses a process for the preparation of a cellulose ester copolymer comprising: i) 92 to 98 mol % of succinic acid, based on components i to ii; ii) 2 to 8 mol % of azelaic acid, sebacic acid and / or brassylic acid, based on components i to ii; iii) 98 to 102 mol % of 1,3-propanediol or 1,4-butanediol, based on components i to ii, and iv) 0.01 wt % to 5 wt %, based on the total weight of components i to iii, of a crosslinking agent iv selected from the group consisting of tartaric acid, citric acid, malic acid, trimethylolpropane, trimethylolethane, pentaerythritol, polyethertriol, glycerol, trimesic acid, trimellitic acid, trimellitic anhydride, pyromellitic acid and pyromellitic anhydride. a and / or a chain extender selected from the group consisting of difunctional isocyanates, isocyanurates, oxazolines and epoxides iv b US Pat. No. 5,399,633 discloses a copolymer obtained by condensation of

[0014] WO1995027760 discloses a composition containing an additive in an amount effective to improve the mar resistance of a solution polymer of an ethylenically unsaturated monomer component containing a polyepoxide essentially free of silyl moieties, a polyacid curing agent, and a polymerizable alkoxysilane monomer.

[0015] Klee at al., Synthesis and investigation of α,ω-methacryloyl poly(epoxide-carboxylic acid) and α,ω-methacryloyl poly(epoxide-phenol) macromonomers; Acta Polymer., 44, 163-167 (1993) discloses the synthesis of α,ω-methacryloyl-terminated macromonomers containing epoxide-carboxylic acid and epoxide-phenol repeat units.

[0016] Thus, there is a need for actinic radiation curable oligomers that provide cured materials with good toughness, hardness, abrasion resistance, solvent resistance, and elasticity properties. Summary of the Invention

[0017] A curable oligomer is provided, the curable oligomer comprising: - x equivalents of component a containing at least one diepoxy); - y 1 equivalent of component b containing at least one unsaturated carboxylic acid); and - y2 equivalents of component c) containing at least one polycarboxylic acid carrying at least three carboxylic acid groups comprising, consisting of, or consisting essentially of the reaction product of x is the number of moles of epoxy groups in component a), y1 is the number of moles of carboxylic acid groups in component b), and y2 is the number of moles of carboxylic acid groups in component c); The ratio of x:(y1+y2) is 1:1.1 to 1:0.90, particularly 1:1.09 to 1:0.91, and more particularly 1:1.08 to 1:0.92.

[0018] Also provided is a method for preparing a curable oligomer, the method comprising: - x equivalents of component a containing at least one diepoxy); - y 2 equivalents of component c containing at least one polycarboxylic acid carrying at least three carboxylic acid groups); and optionally z1 equivalents of component b) comprising at least one unsaturated carboxylic acid to provide an epoxy-capped prepolymer; and then reacting the epoxy-capped prepolymer with z2 equivalents of component b) comprising at least one unsaturated carboxylic acid; comprising, consisting of, or consisting essentially of, z1+z2=y1, x is the number of moles of epoxy groups in component a), y1 is the number of moles of carboxylic acid groups in component b), and y2 is the number of moles of carboxylic acid groups in component c).

[0019] According to another embodiment, there is provided a method for preparing a curable oligomer, the method comprising: - x equivalents of component a containing at least one diepoxy); - y 1 equivalent of component b containing at least one unsaturated carboxylic acid); and - y2 equivalents of component c) containing at least one polycarboxylic acid carrying at least three carboxylic acid groups to provide a curable oligomer, x is the number of moles of epoxy groups in component a), y1 is the number of moles of carboxylic acid groups in component b), y2 is the number of moles of carboxylic acid groups in component c), and the ratio of x:(y1+y2) is 1:1.1 to 1:0.90, particularly 1:1.09 to 1:0.91, and more particularly 1:1.08 to 1:0.92.

[0020] In the method of the present invention, one or both of the following conditions i) and ii) may be achieved: i) the ratio of y2:x is at most 1:4, in particular at most 1:4.5, more particularly at most 1:5; and / or ii) The at least one diepoxy a) comprises at least one compound selected from aliphatic diepoxy, bisphenol-based diglycidyl ethers and combinations thereof; in particular aliphatic diglycidyl ethers, bisphenol-A-diglycidyl ether and combinations thereof; more preferably bisphenol-A-diglycidyl ether. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Curable Oligomer The present inventors have found that certain actinically curable branched oligomers prepared from diepoxy, tricarboxylic or higher carboxylic acid, and unsaturated carboxylic acid, when cured by irradiation, e.g., ultraviolet light, provide good physical properties in terms of toughness, hardness, abrasion resistance, solvent resistance, and elastic properties. These desirable properties have been found to be related to the structure of the oligomer, and in particular to certain molar ratios of monomers used to prepare the branched acrylate functional oligomer. Branched oligomers are defined herein as being the reaction product of certain reactants, and thus will be understood by those skilled in the art to be composed of the residues of reactants remaining in the oligomer so formed.

[0022] Component a) The curable oligomers of the present invention are derived from the reaction of one or more epoxy compounds. The one or more epoxy compounds used to obtain the curable oligomer are referred to herein as component a).

[0023] As used herein, the term "epoxy compound" means a compound bearing at least one epoxy group.

[0024] The curable oligomers of the present invention are obtained using x equivalents of component a).

[0025] As used herein, x is the number of moles of epoxy groups present in component a). x can be obtained by multiplying the number of moles of epoxy compounds in component a) by its epoxide functionality (i.e., the number of epoxide groups on the epoxy compound). For example, if the oligomer of the present invention is obtained using 1 mole of diepoxy, x is equal to 2. If component a) comprises a mixture of epoxy compounds, x corresponds to the total number of moles of epoxy groups in the mixture.

[0026] Component a) comprises, consists of, or consists essentially of at least one diepoxy.

[0027] As used herein, the term "diepoxy" refers to a compound bearing two epoxy groups. As used herein, the term "compound bearing a Z-functional group" refers to a compound that does have a Z-functional group.

[0028] As used herein, the term "X consists essentially of Y" means that X contains more than 90% by weight, or more than 95% by weight, or more than 98% by weight, or more than 99% by weight, or more than 99.5% by weight, or more than 99.8% by weight, or more than 99.9% by weight, or more than 99.95% by weight, or more than 99.99% by weight, or more than 99.995% by weight, or more than 99.999% by weight, based on the weight of X.

[0029] Component a) may be substantially free of compounds bearing more than two epoxy groups.

[0030] As used herein, the term "X is substantially free of Y" means that X contains less than 10% by weight, or less than 5% by weight, or less than 2% by weight, or less than 1% by weight, or less than 0.5% by weight, or less than 0.2% by weight, or less than 0.1% by weight, or less than 0.05% by weight, or less than 0.01% by weight, or less than 0.005% by weight, or less than 0.001% by weight, or even 0% by weight, of Y, based on the weight of X.

[0031] Component a) may comprise, consist of, or consist essentially of at least one diepoxy ether. As used herein, the term "diepoxy ether" refers to a compound carrying two epoxy groups and at least one ether bond (the ether bond is separate from the cyclic ether bond in the epoxy group). In particular, the diepoxy ether may carry two epoxy groups and at least two ether bonds (the ether bond is separate from the cyclic ether bond in the epoxy group).

[0032] Component a) may comprise, consist of, or consist essentially of at least one diglycidyl ether. As used herein, the term "diglycidyl ether" refers to a compound carrying two glycidyl ether groups. As used herein, the term "glycidyl ether group" refers to a compound having the following formula (I): This refers to the base TIFF2024536248000002.tif19170.

[0033] Component a) may comprise, consist, or consist essentially of at least one compound selected from aromatic diepoxy, aliphatic diepoxy, and combinations thereof.

[0034] Component a) may comprise, consist of, or consist essentially of at least one aromatic diepoxy. As used herein, the term "aromatic diepoxy" refers to a compound bearing two epoxy groups bonded together by an aromatic linker.

[0035] As used herein, the term "aromatic linker" refers to a linker that contains at least one aromatic ring, preferably at least two aromatic rings, more preferably two or three aromatic rings. Aromatic aliphatic linkers, i.e., linkers that contain both aromatic and non-aromatic moieties, are encompassed by the term aromatic linker.

[0036] Component a) may comprise, consist of, or consist essentially of at least one aromatic diglycidyl ether. As used herein, the term "aromatic diglycidyl ether" refers to a compound carrying two glycidyl ether groups linked together by an aromatic linker. Such compounds are represented by the following formula (II): TIFF2024536248000003.tif23170 [wherein Ar is an aromatic linker; a is 2] It can be represented by:

[0037] Component a) may comprise, consist of, or consist essentially of at least one bisphenol-based diglycidyl ether. As used herein, the term "bisphenol-based diglycidyl ether" refers to a compound carrying two glycidyl ether groups linked together by an aromatic linker containing a moiety derived from a bisphenol. Such a compound may be represented by the above formula (II), where a is 2 and Ar is represented by the following formula (III): TIFF2024536248000004.tif24170 [wherein L is a linker, R1 and R2 are independently selected from alkyl, cycloalkyl, aryl and halogen atoms; b and c are independently 0 to 4. It is represented by:

[0038] In particular, L may be a linker selected from a bond, -CR3R4-, -C(=O)-, -SO-, -SO2-, -C(=CCl2)- and -CR5R6-Ph-CR7R8-; R3 and R4 are independently selected from H, alkyl, cycloalkyl, aryl, haloalkyl, and perfluoroalkyl, or R3 and R4 can form a ring together with the carbon atom to which they are attached; R5, R6, R7 and R8 are independently selected from H, alkyl, cycloalkyl, aryl, haloalkyl and perfluoroalkyl; Ph is phenylene optionally substituted with one or more groups selected from alkyl, cycloalkyl, aryl and halogen atoms.

[0039] More specifically, Ar may be a residue of a bisphenol that does not have an OH group. The compound according to formula (III) in which Ar is a residue of a bisphenol that does not have an OH group can be called a bisphenol-based diepoxy ether, preferably a bisphenol-based diglycidyl ether. Examples of suitable bisphenols are bisphenol A, bisphenol AP, bisphenol AF, bisphenol B, bisphenol BP, bisphenol C, bisphenol C2, bisphenol F, bisphenol G, bisphenol M, bisphenol S, bisphenol P, bisphenol PH, bisphenol TMC, bisphenol-Z, dinitrobisphenol A, tetrabromobisphenol A, and combinations thereof.

[0040] Component a) may comprise, consist of, or consist essentially of at least one aliphatic diepoxy. As used herein, the term "aliphatic diepoxy" refers to a compound bearing two epoxy groups bonded together by an aliphatic linker.

[0041] As used herein, the term "aliphatic linker" refers to a linker that does not contain any aromatic ring. The aliphatic linker may be a straight-chain or branched, cyclic or acyclic, saturated or unsaturated hydrocarbon linker. The aliphatic linker may be substituted with one or more groups selected from, for example, hydroxyl, halogen (Br, Cl, I, F), carbonyl, amine, carboxylic acid, -C(=O)-OR', -C(=O)-OC(=O)-R' (each R' is independently C1-C6 alkyl). The aliphatic linker may be interrupted by one or more bonds selected from ether (-O-), ester (-C(=O)-O- or -OC(=O)-), amide (-C(=O)-NH- or -NH-C(=O)-), urethane (-NH-C(=O)-O- or -OC(=O)-NH-), urea (-NH-C(=O)-NH-), carbonate (-OC(=O)-O-), and mixtures thereof.

[0042] Component a) may comprise, consist of, or consist essentially of at least one aliphatic diglycidyl ether. As used herein, the term "aliphatic diglycidyl ether" refers to a compound carrying two glycidyl ether groups linked together by an aliphatic linker. Such compounds are represented by the following formula (IV): TIFF2024536248000005.tif23170 [wherein Al is an aliphatic linker; d is 2] It can be represented by:

[0043] In particular, Al may be an alkylene optionally interrupted by one or more ether or ester bonds, or Al may correspond to a partially or fully hydrogenated derivative of the linker of formula (III).

[0044] More specifically, Al is a polyol P having no OH group. OH Suitable polyols P OHExamples of the diols include ethylene glycol, 1,2- or 1,3-propylene glycol, 1,2-, 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, 1,2- or 1,4-cyclohexanedimethanol, norbornene dimethanol, norbornane dimethanol, tricyclodecanediol, tricyclodecane dimethanol, hydrogenated bisphenol 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), sugar alcohols having two OH groups, dianhydrohexitols (i.e. isosorbide, isomannide, isoidide), polybutadiene diols, polyester diols, polyether diols, polyorganosiloxane diols, polycarbonate diols, as well as their alkoxylated (e.g. ethoxylated and / or propoxylated) derivatives and derivatives obtained by ring-opening polymerization of ε-caprolactone initiated with one of the aforementioned diols.

[0045] In one embodiment, component a) may comprise, consist or consist essentially of at least one compound selected from aliphatic diepoxy, bisphenol-based diglycidyl ethers and combinations thereof; in particular aliphatic diglycidyl ethers, bisphenol-A-diglycidyl ethers and combinations thereof; more preferably bisphenol-A-diglycidyl ether.

[0046] Component a) is preferably 1,4-butanediol diglycidyl ether, 1,3-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, 1,2- or 1,4-cyclohexanedimethanol diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, bisphenol-A diglycidyl ether, bisphenol-AP diglycidyl ether, bisphenol-AF diglycidyl ether, bisphenol-B diglycidyl ether, bisphenol-BP diglycidyl ether, bisphenol-C diglycidyl ether, bisphenol-C2 diglycidyl ether, bisphenol-F diglycidyl ether, bisphenol-C ... In some embodiments, the composition may comprise, consist of, or consist essentially of at least one compound selected from bisphenol-G-diglycidyl ether, bisphenol-M-diglycidyl ether, bisphenol-S-diglycidyl ether, bisphenol-P-diglycidyl ether, bisphenol-PH-diglycidyl ether, bisphenol-TMC-diglycidyl ether, bisphenol-Z-diglycidyl ether, dinitrobisphenol-A-diglycidyl ether, tetrabromobisphenol-A-diglycidyl ether, and combinations thereof.

[0047] component b) The curable oligomers of the present invention are derived from the reaction of one or more unsaturated carboxylic acids. The one or more unsaturated carboxylic acids used to obtain the curable oligomer are referred to herein as component b).

[0048] As used herein, the term "unsaturated carboxylic acid" refers to a compound that carries at least one ethylenic unsaturation and at least one carboxylic acid group. As used herein, the term "ethylenic unsaturation" refers to a polymerizable carbon-carbon double bond. A polymerizable carbon-carbon double bond is a carbon-carbon double bond that can react with another carbon-carbon double bond in a polymerization reaction. The polymerizable carbon-carbon double bond is generally included in the group selected from acrylate (including cyanoacrylate), methacrylate, acrylamide, methacrylamide, styrene, maleate, fumarate, itaconate, allyl, propenyl, vinyl and combinations thereof, preferably selected from acrylate, methacrylate and vinyl, more preferably selected from acrylate and methacrylate. Carbon-carbon double bonds of aromatic rings are not considered to be polymerizable carbon-carbon double bonds.

[0049] The curable oligomers of the present invention are obtained using y1 equivalents of component b).

[0050] As used herein, y1 is the number of moles of carboxylic acid groups present in component b). y1 can be obtained by multiplying the number of moles of unsaturated carboxylic acid in component b) by its COOH functionality (i.e., the number of -COOH groups on the unsaturated carboxylic acid). For example, if the oligomer of the present invention is obtained using 1 mole of unsaturated monocarboxylic acid, y1 is equal to 1. If component b) comprises a mixture of unsaturated carboxylic acids, y1 corresponds to the total number of moles of carboxylic acid groups in the mixture.

[0051] Component b) comprises, consists of, or consists essentially of at least one unsaturated carboxylic acid.

[0052] Component b) may comprise, consist or consist essentially of at least one unsaturated carboxylic acid carrying at least one unsaturation and one or two carboxylic acid groups.

[0053] Component b) may be substantially free of unsaturated carboxylic acids bearing more than two carboxylic acid groups.

[0054] Component b) may be substantially free of unsaturated carboxylic acids bearing two carboxylic acid groups.

[0055] Component b) may comprise, consist or consist essentially of an unsaturated carboxylic acid bearing one ethylenic unsaturation and one carboxylic acid group.

[0056] Component b) may comprise, consist of, or consist essentially of at least one α-β ethylenically unsaturated carboxylic acid. As used herein, the term "α-β ethylenically unsaturated carboxylic acid" refers to a compound having ethylenic unsaturation in the α-β position relative to the carbonyl carbon of the carboxylic acid group.

[0057] Component b) may comprise, consist or consist essentially of at least one compound selected from acrylic acid, methacrylic acid, ethacrylic acid, crotonic acid, isocrotonic acid, angelic acid, tiglic acid, senecioic acid, acryloyloxypropionic acid, maleic acid, fumaric acid, itaconic acid and combinations thereof; in particular acrylic acid, methacrylic acid and combinations thereof.

[0058] Ingredient c) The curable oligomers of the present invention are derived from the reaction of one or more polycarboxylic acids. The one or more polycarboxylic acids used to obtain the curable oligomer are referred to herein as component c).

[0059] As used herein, the term "polycarboxylic acid" means a compound bearing at least two carboxylic acid groups.

[0060] The polycarboxylic acid(s) of component c) are preferably distinct from the unsaturated carboxylic acid(s) of component b), and thus component c) may be substantially free of polycarboxylic acids carrying at least one ethylenic unsaturation.

[0061] The curable oligomers of the present invention are obtained using y2 equivalents of component c).

[0062] As used herein, y2 is the number of moles of carboxylic acid groups present in component c). y2 can be obtained by multiplying the number of moles of polycarboxylic acid in component c) by its COOH functionality (i.e., the number of -COOH groups on the polycarboxylic acid). For example, if the oligomer of the present invention is obtained using 1 mole of tricarboxylic acid, y2 is equal to 3. If component c) comprises a mixture of polycarboxylic acids, y2 corresponds to the total number of moles of carboxylic acid groups in the mixture. For example, if the oligomer of the present invention is obtained using 1 mole of tricarboxylic acid and 1 mole of tetracarboxylic acid, y2 is equal to 7 (y2=[1×3]+[1×4]).

[0063] Component c) comprises, consists of or consists essentially of at least one polycarboxylic acid carrying at least three carboxylic acid groups.

[0064] Component c) may comprise, consist or consist essentially of a mixture of at least one dicarboxylic acid and at least one polycarboxylic acid carrying at least three carboxylic acid groups.

[0065] Component c) may be substantially free of dicarboxylic acids.

[0066] Component c) may comprise, consist or consist essentially of at least one tricarboxylic acid. As used herein, the term "tricarboxylic acid" means a compound bearing three carboxylic acid groups.

[0067] Component c) may comprise, consist or consist essentially of at least one polycarboxylic acid carrying at least four carboxylic acid groups.

[0068] Component c) may comprise, consist of, or consist essentially of at least one tetracarboxylic acid. As used herein, the term "tetracarboxylic acid" means a compound bearing four carboxylic acid groups.

[0069] Component c) may comprise, consist or consist essentially of a mixture of at least one tricarboxylic acid and at least one tetracarboxylic acid.

[0070] Component c) may comprise, consist of, or consist essentially of at least one compound selected from citric acid; isocitric acid; 1,2,3-propanetricarboxylic acid; 1,2,4-butanetricarboxylic acid; 1,2,3,4-butanetetracarboxylic acid; 1,2,3,4-cyclobutanetetracarboxylic acid; 1,2,3,4-cyclopentanetetracarboxylic acid; 1,3,5-cyclohexanetricarboxylic acid; 1,2,4,5-cyclohexanetetracarboxylic acid; 1,3,5-benzenetricarboxylic acid; 1,2,4-benzenetricarboxylic acid; 1,2,4,5-benzenetetracarboxylic acid; 1,3,5,7-adamantanetetracarboxylic acid; 1,3,5,7-adamantanetetrabenzoic acid; and combinations thereof.

[0071] Relative amounts of a), b) and c) The present inventors have surprisingly discovered that certain ratios between components a), b) and c) used to form the curable oligomers provide desirable properties to cured compositions containing the curable oligomers. These ratios are expressed in terms of the x, y1 and y2 equivalents, as defined above.

[0072] The ratio of y2:x may be at most 1:4, at most 1:4.5, at most 1:5, at most 1:5.5, at most 1:6, at most 1:6.5, at most 1:7, at most 1:7.5, at most 1:8, at most 1:8.5, at most 1:9, at most 1:9.5, at most 1:10, at most 1:10.5, at most 1:11, at most 1:11.5 or at most 1:12. In one embodiment, the ratio of y2:x may be at most 1:4, in particular at most 1:4.5, more particularly at most 1:5.

[0073] The ratio of y2:x may be at least 1:150, at least 1:140, at least 1:130, at least 1:120, at least 1:110, at least 1:100, at least 1:90, at least 1:80, at least 1:70, at least 1:60, at least 1:50, at least 1:40, at least 1:35, at least 1:30, at least 1:25, at least 1:20 or at least 1:15. In one embodiment, the ratio of y2:x may be at least 1:100, particularly at least 1:20, more particularly at least 1:15.

[0074] The ratio of y2:x may be 1:150 to 1:4, 1:140 to 1:4.5, 1:130 to 1:5, 1:120 to 1:5.5, 1:110 to 1:6, 1:100 to 1:6.5, 1:90 to 1:7, 1:80 to 1:7.5, 1:70 to 1:8, 1:60 to 1:8.5, 1:50 to 1:9, 1:40 to 1:9.5, 1:35 to 1:10, 1:30 to 1:10.5, 1:25 to 1:11, 1:20 to 1:11.5 or 1:15 to 1:12. In one embodiment, the ratio of y2:x may be 1:100 to 1:4, in particular 1:20 to 1:4.5, more particularly 1:15 to 1:5. In another embodiment, the ratio of y2:x may be 1:13 to 1:4, in particular 1:12 to 1:4.5, more particularly 1:11 to 1:5. In another embodiment, the ratio of y2:x may be 1:16 to 1:8, in particular 1:15 to 1:9, more particularly 1:14 to 1:10.

[0075] When multiple lower limits and multiple upper limits are provided herein for a range of a variable or ratio, the invention contemplates every range from any lower limit disclosed to any upper limit disclosed.

[0076] The ratio of x:(y1+y2) may be 1:1.1 to 1:0.90, particularly 1:1.09 to 1:0.91, more particularly 1:1.08 to 1:0.92. In one embodiment, the ratio of x:(y1+y2) may be 1:1.1 to 1:1, particularly 1:1.09 to 1:1.01. In another embodiment, the ratio of x:(y1+y2) may be 1:1.1 to 1:1.05, particularly 1:1.09 to 1:1.06. In another embodiment, the ratio of x:(y1+y2) may be 1:1.05 to 1:1, particularly 1:1.04 to 1:1.01. In another embodiment, the ratio of x:(y1+y2) may be 1:1 to 1:0.90, particularly 1:0.99 to 1:0.91. In another embodiment, the ratio of x:(y1+y2) may be 1:1 to 1:0.95, particularly 1:0.99 to 1:0.96. In another embodiment, the ratio of x:(y1+y2) may be 1:0.95 to 1:0.90, particularly 1:0.94 to 1:0.91.

[0077] The ratio of y2:y1 may be at most 1:1.5, at most 1:2, at most 1:2.5, at most 1:3, at most 1:3.5, at most 1:4, at most 1:4.5, at most 1:5, at most 1:5.5, at most 1:6, at most 1:6.5, at most 1:7, at most 1:7.5, at most 1:8, at most 1:8.5, at most 1:9, at most 1:9.5, at most 1:10, at most 1:10.5, at most 1:11, at most 1:11.5, at most 1:12, at most 1:12.5 or at most 1:13. In one embodiment, the ratio of y2:y1 may be at most 1:1.5, in particular at most 1:4, more particularly at most 1:6.

[0078] The ratio of y2:y1 may be at least 1:150, at least 1:140, at least 1:130, at least 1:120, at least 1:110, at least 1:100, at least 1:90, at least 1:80, at least 1:70, at least 1:60, at least 1:50, at least 1:40, at least 1:35, at least 1:30, at least 1:25, at least 1:20 or at least 1:15. In one embodiment, the ratio of y2:y1 may be at least 1:150, in particular at least 1:100, more particularly at least 1:20.

[0079] The ratio of y2:y1 may be 1:150 to 1:1.5, 1:140 to 1:2, 1:130 to 1:2.5, 1:120 to 1:3, 1:110 to 1:3.5, 1:100 to 1:4, 1:90 to 1:4.5, 1:80 to 1:5, 1:70 to 1:5.5, 1:60 to 1:6, 1:50 to 1:6.5, 1:40 to 1:7, 1:35 to 1:8.5, 1:30 to 1:9, 1:25 to 1:9.5, 1:20 to 1:10 or 1:15 to 1:10.5. In one embodiment, the ratio of y2:y1 may be 1:150 to 1:1.5, in particular 1:100 to 1:4, more particularly 1:20 to 1:6. In another embodiment, the ratio of y2:y1 may be 1:16 to 1:9, in particular 1:15 to 1:10, more particularly 1:14 to 1:11. In another embodiment, the ratio of y2:y1 may be 1:13 to 1:6, in particular 1:12 to 1:7, more particularly 1:11 to 1:8.

[0080] The curable oligomer is preferably substantially free of epoxy groups. To make the curable oligomer substantially free of epoxy groups, the epoxy groups can be reacted according to methods known in the art. For example, the epoxy groups of a) can be reacted with an acid so that the oligomer is substantially free of epoxy groups. If less than stoichiometric amounts of carboxylic acids b) and c) are present, or if carboxylic acids b) and c) react too slowly or do not complete the reaction with the epoxy groups of a), the remaining epoxy groups can be reacted according to methods known in the art, for example with a strong acid other than acids b) and c). For this purpose, phosphoric acid is suitable.

[0081] Component a) may be present residually in the curable oligomer at 50-95 wt%, based on the weight of the curable oligomer. For example, component a) may be present residually in the curable oligomer at 55-90 wt%, 60-85 wt%, or 65-80 wt%, based on the weight of the curable oligomer.

[0082] Component b) may be present residually in the curable oligomer at 10-50 wt%, based on the weight of the curable oligomer. For example, component b) may be present residually in the curable oligomer at 15-45 wt%, 20-40 wt%, or 20-30 wt%, based on the weight of the curable oligomer. The amount may vary depending on the molecular weight and functionality of the diepoxy a) and the molecular weight and functionality of the carboxylic acids b) and c).

[0083] Component c) may be present residually in the curable oligomer at 0.01 to 10 wt%, based on the weight of the curable oligomer. For example, component c) may be present residually in the curable oligomer at 0.5 to 7.5 wt%, 1 to 5 wt%, or 1 to 3 wt%, based on the weight of the curable oligomer.

[0084] When component c) comprises a mixture of polycarboxylic acids, each polycarboxylic acid may be present at these levels. For example, when two polycarboxylic acids are present in component c), they may each be present as residuals at 0.01-10 wt%, 0.5-7.5 wt%, 1-5 wt%, or 1-3 wt% based on the weight of the curable oligomer, but the total amount of polycarboxylic acids should not exceed 10 wt% based on the weight of the curable oligomer. In a preferred embodiment, each polycarboxylic acid may be present as residuals in the curable oligomer at 0.05-1.99 wt%, based on the weight of the curable oligomer.

[0085] The oligomers of the present invention are obtained by reacting components a), b) and c). The reaction mixture used to obtain the oligomers may be substantially free of dicarboxylic acids, and preferably substantially free of components other than components a), b) and c), non-reactive diluents, catalysts and inhibitors.

[0086] The oligomer is preferably substantially free of residues derived from dicarboxylic acids. The oligomer preferably consists essentially of or consists of residues derived from the reaction of components a), b) and c).

[0087] The total weight of the residue derived from the reaction of components a), b) and c) may account for at least 90%, at least 95%, at least 98%, at least 99%, at least 99.5%, at least 99.9%, at least 99.99% or even 100% of the total weight of the oligomer of the invention.

[0088] curable composition The curable composition of the present invention comprises a curable oligomer of the present invention as defined above, referred to as component i). The curable composition of the present invention may further comprise one or more ethylenically unsaturated compounds, referred to as component ii), and / or inhibitors. The curable composition may further comprise a photoinitiator.

[0089] The curable composition of the present invention comprises, based on the total weight of components i) and ii), - 5-95%, 10-90%, 15-85%, 20-80%, 25-75%, 30-70%, 35-65% or 40-60% of the composition i); - 5-95%, 10-90%, 15-85%, 20-80%, 25-75%, 30-70%, 35-65% or 40-60% of the components ii) (% is by weight).

[0090] Ethylenically unsaturated compounds The curable compositions of the present invention may include one or more ethylenically unsaturated compounds, referred to as component ii).

[0091] Component ii) may comprise at least one ethylenically unsaturated compound selected from (meth)acrylate-functionalized monomers, (meth)acrylate-functionalized oligomers, and mixtures thereof.

[0092] As used herein, the term "(meth)acrylate-functionalized monomer" refers to a monomer that contains a (meth)acrylate group, particularly an acrylate group. The term "(meth)acrylate-functionalized oligomer" refers to an oligomer that contains a (meth)acrylate group, particularly an acrylate group. The term "(meth)acrylate group" encompasses acrylate groups (-O-CO-CH=CH2) and methacrylate groups (-O-CO-C(CH3)=CH2).

[0093] Component ii) may comprise at least one (meth)acrylate-functionalized monomer.

[0094] The (meth)acrylate functionalized monomer may have a molecular weight of less than 600 g / mol, in particular from 100 to 550 g / mol, more particularly from 200 to 500 g / mol.

[0095] The (meth)acrylate functionalized monomer can have 1 to 6 (meth)acrylate groups, particularly 1 to 4 (meth)acrylate groups.

[0096] The (meth)acrylate-functionalized monomers may include mixtures of (meth)acrylate-functionalized monomers having different degrees of functionality. For example, the (meth)acrylate-functionalized monomers may include mixtures of (meth)acrylate-functionalized monomers containing a single acrylate or methacrylate group per molecule (referred to herein as "mono(meth)acrylate-functionalized compounds"), as well as mixtures of (meth)acrylate-functionalized monomers containing two or more, preferably two or three, acrylate and / or methacrylate groups per molecule.

[0097] Component i) may comprise at least one mono(meth)acrylate functionalized monomer, which may advantageously function as a reactive diluent and reduce the viscosity of the composition of the present invention.

[0098] Examples of suitable mono(meth)acrylate functionalized monomers include mono-(meth)acrylate esters of aliphatic alcohols (wherein the aliphatic alcohol may be linear, branched, or alicyclic and may be monohydric, dihydric, or polyhydric alcohols, provided that only one hydroxy group is esterified with (meth)acrylic acid); mono-(meth)acrylate esters of aromatic alcohols (e.g., phenols, including alkylated phenols); mono-(meth)acrylate esters of alkylaryl alcohols (e.g., benzyl alcohol); mono-(meth)acrylate esters of oligomeric and polymeric glycols, such as diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol, and polypropylene glycol). -(meth)acrylate esters; 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 (the fatty alcohols may be linear, branched or alicyclic and may be monohydric, dihydric or polyhydric alcohols, provided that only one hydroxy 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 (e.g., alkoxylated phenols); caprolactone mono(meth)acrylate, and the like.

[0099] The following compounds are illustrative of mono(meth)acrylate functionalized monomers suitable for use in the curable compositions of the present invention: 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; METHA)ACRYLATES;TETRADECYL(METHA)ACRYLATE;HEXADECYL(METHA)ACRYLATE;2-HYDROXYETHYL(METHA)ACRYLATE;2-AND 3-HYDROXYPROPYL(METHA)ACRYLATE;2-METHOXYETHYL(METHA)ACRYLATE;2-ETHOXYETHYL(METHA)ACRYLATE;2-AND 3-ETHOXYPROPYL(METHA)ACRYLATE;TETRAHYDROFURFURYL(METHA)ACRYLATE;ALKOXYLATED TETRAHYDROFURFURYL(METHA)ACRYLATE;2-(2-ETHOXYETHOXY)ETHYL(METHA)ACRYLATE;CYCLOHEXYL(METHACRYLATE) t)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;Tricyclodecane methanol (meth)acrylate;tert-Butyl cyclohexanol (meth)acrylate;Trimethylcyclohexanol (meth)acrylate acrylate; diethylene 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.

[0100] Component ii) may include at least one (meth)acrylate-functionalized monomer containing two or more (meth)acrylate groups per molecule.

[0101] Examples of suitable (meth)acrylate-functionalized monomers containing two or more (meth)acrylate groups per molecule include acrylate and methacrylate esters of polyhydric alcohols (organic compounds containing two or more, e.g., 2-6, hydroxy groups per molecule). 2~20 Alkylene glycol (C 2~10Glycols having alkylene groups may be preferred, the carbon chain of which may be branched; for example, ethylene glycol, trimethylene glycol, 1,2-propylene glycol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, tetramethylene glycol (1,4-butanediol), 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,12-dodecanediol, cyclohexane-1,4-dimethanol, bisphenols, and hydrogenated bisphenols, as well as their alkoxylated (e.g., ethoxylated and / or propoxylated) derivatives, diethylene glycol, glycerin, alkoxylated glycerin, triethylene glycol, dipropylene glycol, tripropylene glycol, trimethylolpropane, alkoxylated trimethylolpropane, ditrimethylolpropane, diisopropyl ether ... propane, alkoxylated ditrimethylolpropane, pentaerythritol, alkoxylated pentaerythritol, dipentaerythritol, alkoxylated dipentaerythritol, cyclohexanediol, alkoxylated cyclohexanediol, cyclohexanedimethanol, alkoxylated cyclohexanedimethanol, norbornene dimethanol, alkoxylated norbornene dimethanol, norbornane dimethanol, alkoxylated norbornane dimethanol, polyols containing aromatic rings, cyclohexane-1,4-dimethanol ethylene oxide adducts, bis-phenol ethylene oxide adducts, hydrogenated bisphenol ethylene oxide adducts, bisphenol propylene oxide adducts, hydrogenated bisphenol propylene oxide adducts, cyclohexane-1,4-dimethanol propylene oxide adducts, sugar alcohols and alkoxylated sugar alcohols. Such polyhydric alcohols may be fully or partially esterified (with (meth)acrylic acid, (meth)acrylic anhydride, (meth)acryloyl chloride, etc.), provided that they contain at least two (meth)acrylate functional groups per molecule.

[0102] Exemplary (meth)acrylate functionalized monomers containing two or more (meth)acrylate groups per molecule include ethoxylated bisphenol A di(meth)acrylate; triethylene glycol di(meth)acrylate; ethylene glycol di(meth)acrylate; tetraethylene glycol di(meth)acrylate; polyethylene glycol di(meth)acrylate; 1,4-butanediol diacrylate; 1,4-butanediol dimethacrylate; diethylene glycol diacrylate; diethylene glycol dimethacrylate, 1,6-hexanediol diacrylate; 1,6-hexanediol dimethacrylate; neopentyl glycol diacrylate; neopentyl glycol di(meth)acrylate; polyethylene glycol (60 0) dimethacrylate (600 refers to the approximate number average amount of polyethylene glycol moieties);Polyethylene glycol (200) diacrylate;1,12-dodecanediol dimethacrylate;Tetraethylene glycol diacrylate;Triethylene glycol diacrylate, 1,3-butylene glycol dimethacrylate, tripropylene glycol diacrylate, polybutadiene diacrylate;Methylpentanediol diacrylate;Polyethylene glycol (400) diacrylate;Ethoxylated 2 bisphenol A dimethacrylate;Ethoxylated 3 bisphenol A dimethacrylate;Ethoxylated 3 bisphenol A diacrylate;Cyclohexane dimethanol dimethacrylate;Cyclohexane dimethanol diacrylate;Ethoxylated 10 Bisphenol A dimethacrylate (the number after "ethoxylated" is the average number of oxyalkylene moieties per molecule);Dipropylene glycol diacrylate;Ethoxylated 4 Bisphenol A dimethacrylate;Ethoxylated 6 Bisphenol A dimethacrylate;Ethoxylated 8 Bisphenol A dimethacrylate;Alkoxylated Hexanediol Diacrylate;Alkoxylated Cyclohexanedimethanol Diacrylate;Dodecane Diacrylate;Ethoxylated 4 Bisphenol A Diacrylate;Ethoxylated 10Bisphenol A diacrylate;Polyethylene glycol (400) dimethacrylate;Polypropylene glycol (400) dimethacrylate;Metal diacrylates;Modified metal diacrylates;Metal dimethacrylates;Polyethylene glycol (1000) dimethacrylate;Methacrylated polybutadiene;Propoxylated 2-neopentyl glycol diacrylate;Ethoxylated 30 Bisphenol A dimethacrylate; ethoxylated 30 Bisphenol A diacrylate;Alkoxylated neopentyl glycol diacrylate;Polyethylene glycol dimethacrylate;1,3-Butylene glycol diacrylate;Ethoxylated 2 bisphenol A dimethacrylate;Dipropylene glycol diacrylate;Ethoxylated 4 bisphenol A diacrylate;Polyethylene glycol (600) diacrylate;Polyethylene glycol (1000) dimethacrylate;Tricyclodecane dimethanol diacrylate;Propoxylated neopentyl glycol diacrylate, e.g., propoxylated 2 neopentyl glycol diacrylate;Diacrylates of alkoxylated fatty alcohols;Trimethylolpropane trimethacrylate;Trimethylolpropane triacrylate;Tris(2-hydroxyethyl)isocyanurate triacrylate;Ethoxylated 20 Trimethylolpropane triacrylate;Pentaerythritol triacrylate;Ethoxylated 3 trimethylolpropane triacrylate;Propoxylated 3 trimethylolpropane triacrylate;Ethoxylated 6 trimethylolpropane triacrylate;Propoxylated 6 trimethylolpropane triacrylate;Ethoxylated 9 trimethylolpropane triacrylate;Alkoxylated trifunctional acrylate esters;Trifunctional methacrylate esters;Trifunctional acrylate esters;Propoxylated 3 glyceryl triacrylate;Propoxylated 5.5 Glyceryl triacrylate; ethoxylated 15trifunctional phosphate esters; trifunctional acrylic esters; pentaerythritol tetraacrylate; di-trimethylolpropane tetraacrylate; ethoxylated 4 pentaerythritol tetraacrylate; pentaerythritol polyoxyethylene tetraacrylate; dipentaerythritol pentaacrylate; and pentaacrylate esters may be mentioned.

[0103] Component i) may include at least one (meth)acrylate-functionalized oligomer.

[0104] (Meth)acrylate-functionalized oligomers may be selected to enhance the flexibility, strength and / or modulus, among other attributes, of the cured polymers prepared using the curable compositions of the present invention.

[0105] The (meth)acrylate-functionalized oligomer can have 1 to 18 (meth)acrylate groups, specifically 2 to 6 (meth)acrylate groups, and more specifically 2 to 6 acrylate groups.

[0106] The (meth)acrylate-functionalized oligomer may have a number average molecular weight greater than or equal to 600 g / mol, in particular from 800 to 15,000 g / mol, and more particularly from 1,000 to 5,000 g / mol.

[0107] In particular, the (meth)acrylate-functionalized oligomer may be selected from the group consisting of (meth)acrylate-functionalized urethane oligomers (sometimes referred to as "urethane (meth)acrylate oligomers", "polyurethane (meth)acrylate oligomers" or "carbamate (meth)acrylate oligomers"), (meth)acrylate-functionalized epoxy oligomers (sometimes referred to as "epoxy (meth)acrylate oligomers"), (meth)acrylate-functionalized polyether oligomers (sometimes referred to as "polyether (meth)acrylate oligomers"), (meth)acrylate-functionalized polydiene oligomers (sometimes referred to as "polydiene (meth)acrylate oligomers"), (meth)acrylate-functionalized polycarbonate oligomers (sometimes referred to as "polycarbonate (meth)acrylate oligomers") and (meth)acrylate-functionalized polyester oligomers (sometimes referred to as "polyester (meth)acrylate oligomers"), and mixtures thereof.

[0108] Exemplary polyester (meth)acrylate oligomers include the reaction products of acrylic acid or methacrylic acid or mixtures or synthetic equivalents thereof with hydroxyl-terminated polyester polyols. The reaction process can be carried out such that all or essentially all of the hydroxyl groups of the polyester polyol are (meth)acrylated, especially when the polyester polyol is difunctional. The polyester polyols can be made by the polycondensation reaction of polyhydroxyl-functional components (especially diols) and polycarboxylic acid-functional compounds (especially dicarboxylic acids and anhydrides). The polyhydroxyl-functional components and polycarboxylic acid-functional components can each have a linear, branched, alicyclic or aromatic structure and can be used individually or as a mixture.

[0109] Examples of suitable epoxy (meth)acrylates include the reaction products of acrylic acid or methacrylic acid or mixtures thereof with epoxy resins (polyglycidyl ethers or esters). Epoxy resins include, in particular, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, brominated bisphenol A diglycidyl ether, brominated bisphenol F diglycidyl ether, brominated bisphenol S diglycidyl ether, novolac type epoxy resins, hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol S diglycidyl ether, 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate, 2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) ... Hexane-1,4-dioxane, bis(3,4-epoxycyclohexylmethyl)adipate, vinylcyclohexene oxide, 4-vinylepoxycyclohexane, bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate, 3,4-epoxy-6-methylcyclohexyl-3',4'-epoxy-6'-methylcyclohexanecarboxylate, methylene bis(3,4-epoxycyclohexane), dicyclopentadiene diepoxide, di(3,4-epoxycyclohexylmethyl)ether of ethylene glycol, ethylene bis(3,4-epoxycyclohexanecarboxylate), 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polyglycidyl ethers of polyether polyols obtained by adding one or more alkylene oxides to aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol, and glycerol, diglycidyl esters of aliphatic long-chain dibasic acids, monoglycidyl ethers of aliphatic higher alcohols, monoglycidyl ethers of polyether alcohols obtained by adding alkylene oxides to phenol, cresol, butylphenol, or these compounds, glycidyl esters of higher fatty acids, epoxidized soybean oil, epoxy butyl stearate, epoxy octyl stearate, epoxidized linseed oil, epoxidized polybutadiene, etc.,

[0110] Suitable polyether (meth)acrylate oligomers include, but are not limited to, the condensation reaction products of acrylic acid or methacrylic acid or their synthetic equivalents or mixtures with polyetherols, which are polyether polyols (e.g., polyethylene glycol, polypropylene glycol, or polytetramethylene glycol). Suitable polyetherols may be linear or branched materials containing ether linkages and terminal hydroxy groups. Polyetherols can be prepared by ring-opening polymerization of cyclic ethers, such as tetrahydrofuran or alkylene oxides (e.g., ethylene oxide and / or propylene oxide), with starter molecules. Suitable starter molecules include water, polyhydroxyl-functional materials, polyester polyols, and amines.

[0111] Suitable positive urethane (meth)acrylate oligomers (sometimes referred to as "urethane (meth)acrylate oligomers") for use in the curable compositions of the present invention include urethanes based on aliphatic, cycloaliphatic and / or aromatic polyester polyols and polyether polyols, and aliphatic, cycloaliphatic and / or aromatic polyester diisocyanates and polyether diisocyanates, capped with (meth)acrylate end groups. Suitable polyurethane (meth)acrylate oligomers include, for example, aliphatic polyester-based urethane di- and tetra-acrylate oligomers, aliphatic polyether-based urethane di- and tetra-acrylate oligomers, and aliphatic polyester / polyether-based urethane di- and tetra-acrylate oligomers.

[0112] Polyurethane (meth)acrylate oligomers can be prepared by reacting an aliphatic, cycloaliphatic and / or aromatic polyisocyanate (e.g., diisocyanate, triisocyanate) with an OH-terminated polyester polyol, polyether polyol, polycarbonate polyol, polycaprolactone polyol, polyorganosiloxane polyol (e.g., polydimethylsiloxane polyol) or polydiene polyol (e.g., polybutadiene polyol), or a combination thereof, to form an isocyanate-functionalized oligomer, which is then reacted with a hydroxyl-functionalized (meth)acrylate, such as hydroxyethyl acrylate or hydroxyethyl methacrylate, to provide terminal (meth)acrylate groups. For example, polyurethane (meth)acrylate oligomers can contain two, three, four or more (meth)acrylate functional groups per molecule. As known in the art, other addition sequences can also be performed to prepare polyurethane (meth)acrylates. For example, a hydroxyl-functionalized (meth)acrylate can be first reacted with a polyisocyanate to give an isocyanate-functionalized (meth)acrylate, which can then be reacted with an OH-terminated polyester polyol, polyether polyol, polycarbonate polyol, polycaprolactone polyol, polydimethylsiloxane polyol, polybutadiene polyol, or combinations thereof. In yet another embodiment, a polyisocyanate can be first reacted with a polyol, including any of the aforementioned types of polyols, to give an isocyanate-functionalized polyol, which is then reacted with a hydroxyl-functionalized (meth)acrylate to give a polyurethane (meth)acrylate. Alternatively, all components can be combined and reacted simultaneously.

[0113] Suitable acrylic (meth)acrylate oligomers (sometimes referred to in the art as "acrylic oligomers") include oligomers that may be described as materials having an oligomeric acrylic backbone that is functionalized with one or more (meth)acrylate groups, which may be at the end of the oligomer or pendant to the acrylic backbone. The acrylic backbone may be a homopolymer, random copolymer, or block copolymer made up of repeating units of acrylic monomers. The acrylic monomers may be any monomeric (meth)acrylate, such as C1-C6 alkyl (meth)acrylates, as well as functionalized (meth)acrylates, such as (meth)acrylates bearing hydroxy, carboxylic acid, and / or epoxy groups. Acrylic (meth)acrylate oligomers can be prepared using any procedure known in the art, for example, by oligomerizing monomers at least some of which are functionalized with hydroxy, carboxylic acid and / or epoxy groups (e.g., hydroxyalkyl (meth)acrylates, (meth)acrylic acid, glycidyl (meth)acrylate) to obtain a functionalized oligomeric intermediate which is then reacted with one or more (meth)acrylate-containing reactants to introduce the desired (meth)acrylate functionality.

[0114] Inhibitors The curable compositions of the present invention may include at least one inhibitor.

[0115] Inhibitors may be introduced into the curable composition to provide adequate storage stability and shelf life. In addition, inhibitors may be used during the preparation of the curable composition to protect the ethylenically unsaturated components of the curable composition from undesired reactions during processing. The inhibitor may be a compound or substance that retards or prevents the reaction or curing of the actinically polymerizable functional groups present in the composition in the absence of actinic radiation. However, it is advantageous to select the amount and type of inhibitor so that the composition is still curable when exposed to actinic radiation (i.e., the inhibitor does not prevent the radiation curing of the composition). The inhibitor may in particular be a free radical inhibitor (i.e., an inhibitor that functions by inhibiting free radical reactions).

[0116] Any of the inhibitors known in the art for (meth)acrylate-functionalized compounds can be utilized in the present invention.Quinones are a particularly preferred type of inhibitor that can be used in the context of the present invention.As used herein, the term "quinone" includes both quinones and hydroquinones, as well as their ethers, such as monoalkyl, monoaryl, monoaralkyl, and bis(hydroxyalkyl) ethers of hydroquinone.Hydroquinone monomethyl ether is one example of a suitable inhibitor that can be utilized.Other inhibitors known in the art include hydroquinone (HQ), 4-tert-butylcatechol (TBC), 3,5-di-tertiobutyl-4-hydroxytoluene (BHT), phenothiazine (PTZ), pyrogallol, phosphorous compounds, triphenylantimony, and tin(II) salts.

[0117] The concentration of inhibitor in the curable composition varies depending on the particular inhibitor or combination of inhibitors selected for use, as well as the degree of inhibition desired, and the susceptibility of the components in the curable composition to degradation in the absence of the inhibitor. Typically, however, the curable composition is formulated to contain 5-5000 ppm of inhibitor based on the total amount of polymerizable compounds in the curable composition. According to certain embodiments of the present invention, the reaction mixture during each stage of the method used to make the curable composition contains at least a portion of inhibitor, for example at least 10 ppm of inhibitor.

[0118] Photoinitiators The curable compositions of the present invention may include at least one photoinitiator.

[0119] The photoinitiator may be a radical photoinitiator, particularly a radical photoinitiator with Norrish Type I activity and / or Norrish Type II activity, more particularly a radical photoinitiator with Norrish Type I activity.

[0120] Non-limiting types of radical photoinitiators suitable for use in the curable compositions of the present invention include, for example, benzoin, benzoin ethers, acetophenone, α-hydroxyacetophenone, benzil, benzil ketals, anthraquinones, phosphine oxides, acylphosphine oxides, α-hydroxyketones, phenylglyoxylates, α-aminoketones, benzophenones, thioxanthones, xanthones, acridine derivatives, phenazene derivatives, quinoxaline derivatives, triazine compounds, benzoylformic acid, aromatic oximes, metallocenes, acylsilyl or acylgermanyl compounds, camphorquinone, polymeric derivatives thereof, and mixtures thereof.

[0121] Examples of suitable radical photoinitiators include 2-methylanthraquinone, 2-ethylanthraquinone, 2-chloroanthraquinone, 2-benzyanthraquinone, 2-t-butylanthraquinone, 1,2-benzo-9,10-anthraquinone, benzil, benzoin, benzoin ether, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, alpha-methylbenzoin, alpha-phenylbenzoin, Michler's ketone, acetophenone, e.g. 2,2-diazomethanesulfonyl ether, benzoin ...benzoin ether, benzoin ether, benzoin ether, benzoin ether, benzoin ether, benzoin ether, benzoin ether, benzoin ether, benzoin ether, benzoin ether, benzoin ether, benzoin ether, benzoin ether, benzoin ether, benzoin ether, benzoin ether, benzoin ether, benzoin ether, Alkoxybenzophenone and 1-hydroxyphenyl ketone, benzophenone, 4,4'-bis-(diethylamino)benzophenone, acetophenone, 2,2-diethyloxyacetophenone, diethyloxyacetophenone, 2-isopropylthioxanthone, thioxanthone, diethylthioxanthone, 1,5-acetonaphthylene, benzyl ketone, α-hydroxyketo, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, benzyl dimethyl ketal, 2,2-dimethoxy-1,2-diphenylphosphine oxide ... Phenyl ethanone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropanone-1, 2-hydroxy-2-methyl-1-phenyl-propanone, oligomeric α-hydroxyketone, benzoylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, ethyl(2,4,6-trimethylbenzoyl)phenylphosphinate, anisoin, anthraquinone, anthraquinone-2-sulfonic acid, sodium Salt monohydrate, (benzene)tricarbonylchromium, benzil, benzoin isobutyl ether, benzophenone / 1-hydroxycyclohexyl phenyl ketone, 50 / 50 blend, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 4-benzoylbiphenyl, 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone, 4,4'-bis(diethylamino)benzophenone, 4,4'-bis(dimethylamino)benzophenone, camphorquinone, 2-chlorothioxanthen-9-one, dibenzosuberenone, 4,4'-Dihydroxybenzophenone, 2,2-dimethoxy-2-phenylacetophenone, 4-(dimethylamino)benzophenone, 4,4'-dimethylbenzyl, 2,5-dimethylbenzophenone, 3,4-dimethylbenzophenone, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide / 2-hydroxy-2-methylpropiophenone, 50 / 50 blend, 4'-ethoxyacetophenone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, ferrocene, 3'-hydroxyacetophenone, 4'-hydroxyacetophenone, 3 4-hydroxybenzophenone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methylpropiophenone, 2-methylbenzophenone, 3-methylbenzophenone, methylbenzoylformate, 2-methyl-4'-(methylthio)-2-morpholinopropiophenone, phenanthrenequinone, 4'-phenoxyacetophenone, (cumene)cyclopentadienyliron(II) hexafluorophosphate, 9,10-diethoxy and 9,10-dibutoxyanthracene, 2-ethyl-9,10-dimethoxyanthracene, thioxanthen-9-one, and combinations thereof.

[0122] In particular, the photoinitiator may be a benzophenone (e.g., Speedcure® BP, Speedcure® 7005, Speedcure® 7006), a thioxanthone (e.g., Speedcure® 7010, Speedcure® ITX), an α-hydroxyacetophenone, an acylphosphine oxide (e.g., Speedcure® BPO, Speedcure® TPO, Speedcure® TPO-L).

[0123] The amount of photoinitiator in the hardenable composition can vary as may be appropriate depending on, among other factors, the photoinitiator(s) selected, the amount and type of polymerizable compounds intended to be photopolymerized, the irradiation source and irradiation conditions used, but typically the hardenable composition comprises 0.5 to 25%, particularly 1 to 20%, more particularly 1.5 to 15%, and even more particularly 2 to 10% of photoinitiator based on the total weight of the polymerizable compounds in the hardenable composition.

[0124] Additives Other additives that may be present in the curable composition include, but are not limited to, UV cure catalysts, antioxidants, ultraviolet light absorbers, defoamers, flow or leveling agents, colorants, pigments, dispersants (wetting agents), slip additives, fillers, thixotropic agents, matting agents, thermoplastic resins such as acrylic resins that do not contain any functional groups polymerizable with free radicals, waxes, or various other additives including any of the additives conventionally utilized in the coating, sealant, adhesive, molding or ink arts.

[0125] method Also provided is a method for preparing a curable oligomer of the present invention. According to one embodiment, the method comprises: - x equivalents of component a containing at least one diepoxy); - y 2 equivalents of component c containing at least one polycarboxylic acid carrying at least three carboxylic acid groups); and optionally z1 equivalents of component b) comprising at least one unsaturated carboxylic acid to provide an epoxy-capped prepolymer.

[0126] The epoxy-capped prepolymer is then reacted with z2 equivalents of component b) comprising at least one unsaturated carboxylic acid b) to provide a curable oligomer.

[0127] The sum z1+z2=y1. If a portion of component b) is added in the step of obtaining the epoxy-capped prepolymer, the z1 / z2 ratio may be 0.1-0.95, or 0.2-0.9, or 0.5-0.7, or 0.45-0.55. If component b) is not added in the step of obtaining the epoxy-capped prepolymer, z1=0 and y1=z2.

[0128] x is defined as the number of moles of epoxy groups in component a), y1 is the number of moles of carboxylic acid groups in component b), and y2 is the number of moles of carboxylic acid groups in component c), and the ratio of x:(y1+y2) may be 1:1.1 to 1:0.90, in particular 1:1.09 to 1:0.91, more particularly 1:1.08 to 1:0.92.

[0129] According to one embodiment, component b) may be added in one or more additions to a reaction mixture comprising, consisting of, or consisting essentially of components a) and c) during the step of obtaining the epoxy-capped prepolymer and / or during the step of obtaining the curable oligomer.

[0130] According to another embodiment, there is provided a method of making a curable oligomer, the method comprising: - x equivalents of component a containing at least one diepoxy); - y 1 equivalent of component b containing at least one unsaturated carboxylic acid); and - y2 equivalents of component c) containing at least one polycarboxylic acid carrying at least three carboxylic acid groups to provide a curable oligomer.

[0131] x is defined as the number of moles of epoxy groups in component a), y1 is defined as the number of moles of carboxylic acid groups in component b), and y2 is defined as the number of moles of carboxylic acid groups in component c), and the ratio of x:(y1+y2) is 1:1.1 to 1:0.90, particularly 1:1.09 to 1:0.91, more particularly 1:1.08 to 1:0.92.

[0132] In the method of the present invention, one or both of the following conditions i) and ii) may be achieved: i) the ratio of y2:x is at most 1:4, in particular at most 1:5, more particularly at most 1:6, and / or ii) The at least one diepoxy a) comprises at least one of a bisphenol-based diglycidyl ether or an aliphatic diepoxy.

[0133] Purpose These oligomers of the present invention can be used alone or in combination with other (meth)acrylate functional oligomers or monomers to form curable overprint varnishes or coatings.Other uses include, but are not limited to, three-dimensional printing and printer inks.End uses for the curable compositions containing the curable oligomers of the present invention include, but are not limited to, inks, coatings, adhesives, additive manufacturing resins (e.g., 3D printing resins), molding resins, sealants, composites, antistatic layers, electronic applications, recyclable materials, smart materials that can detect and respond to stimuli, and biomedical materials.

[0134] While the embodiments have been described herein in a manner that enables a clear and concise specification to be written, it is intended, and will be recognized, that the embodiments may be variously combined or separated without departing from the invention, and for example, it will be recognized that all preferred features described herein are applicable to all aspects of the invention described herein.

[0135] In some embodiments, the invention may be construed herein to exclude any element or process step that does not substantially affect the basic and novel properties of the actinic radiation curable compositions, the methods for making the actinic radiation curable compositions, the methods for using the actinic radiation curable compositions, and the articles prepared from the actinic radiation curable compositions. In addition, in some embodiments, the invention may be construed herein to exclude any element or process step not specified herein. EXAMPLES

[0136] method Sample preparation Film: 0.2mm thick film, 400W / in 2 The material was cured under an H-Bulb (mercury vapor) with an intensity of (400 W / 4.45 cm2) at a cure speed of 50 ft / min (15.25 m / min).

[0137] Coating: 0.2mm thick film on aluminum panel, 400W / in 2 The material was cured under an H-Bulb (mercury vapor) with an intensity of (400 W / 4.45 cm2) at a cure speed of 50 ft / min (15.25 m / min).

[0138] Tensile strength in psi (Pa), elongation in %, Young's modulus in psi (Pa), and energy to break in J were measured according to ASTM D882-18 using an Instron tensile testing machine.

[0139] MEK (methyl ethyl ketone) Rub was measured according to ASTM D5402-19.

[0140] Konig hardness was measured according to ASTM D4366-09.

[0141] Taber abrasion after 500 cycles was measured according to ASTM 4060-10 and reported as % gram difference.

[0142] Initial 60 degree gloss was measured according to ASTM D523-08.

[0143] Brookfield viscosity was obtained using a DVII+ Brookfield viscometer equipped with spindle #27 at speeds achieving 20-80% of maximum torque.

[0144] Gel permeation chromatography was used to obtain the weight average molecular weight Mw and number average molecular weight Mn using an Agilent 1260 GPC equipped with a refractive index detector and using polystyrene standards for calibration.

[0145] Example 1 Oligomer #1 containing 2 wt% citric acid 1 mole of citric acid (loading 2 wt%), 19.446 moles of bisphenol A diglycidyl ether (DER™ 331, Dow), 9.017 moles of acrylic acid (Beantown), 0.15 wt% of mequinol (MeHQ) (Aldrich) as inhibitor and 0.35 wt% of benzyltriethylammonium chloride (BTEAC) (Aldrich) as catalyst were thoroughly mixed and heated to 90° C. under air sparge. The remaining 25.380 moles of acrylic acid were metered into the mixture over 1 hour to control the exotherm temperature below 125° C. Then the reaction was carried out at 125° C. until the termination criteria of acid value (AV)<2 mg KOH / gm and epoxy value (EV)<5 mg KOH / gm were reached (about 6 hours). AV and EV were adjusted by adding 1.128 moles of acrylic acid. The final product was a clear, pale yellow, viscous liquid with a Brookfield viscosity of 8096 mPa·s (cP) at 65°C. The x:(y1+y2) ratio was 1:0.99. The y2:x ratio was 1:12.96.

[0146] The results show that a loading of 2 wt% citric acid resulted in 13 wt% branched epoxy acrylate and 6 mol% branching. The viscosity increase indicated the presence of branched molecules.

[0147] Example 2 Oligomer #2 containing 2 wt% 1,2,3,4 butanetetracarboxylic acid 1 mole of 1,2,3,4-butanetetracarboxylic acid (2 wt% loading) (Aldrich), 22.982 moles of bisphenol A diglycidyl ether, 12.586 moles of acrylic acid, 0.15 wt% of MeHQ as inhibitor and 0.35 wt% of BTEAC as catalyst were thoroughly mixed and heated to 90°C under air sparge. The remaining 31.582 moles of acrylic acid were metered into the mixture over 1 hour to control the exotherm temperature below 125°C. The reaction was then carried out at 125°C until the termination criteria of AV<2 mg KOH / gm and EV<5 mg KOH / gm were reached (approximately 6 hours). The AV and EV were adjusted by adding 0.785 moles of acrylic acid. The final product was a clear light yellow viscous liquid with a Brookfield viscosity of 7237 mPa·s (cP) at 65°C. The x:(y1+y2) ratio was 1:1.065. The y2:x ratio was 1:11.49.

[0148] The results for Example 2 show that 2 wt% loadings of citric acid and 2 wt% loadings of 1,2,3,4-butanetetracarboxylic acid yielded 17 wt% branched epoxy acrylate and 5 mol%. Branching was also confirmed by the high Brookfield viscosity of 7237 mPa·s at 65°C. Gel permeation chromatography using polystyrene standards showed a number average molecular weight Mn of 2229 g / mol and a weight average molecular weight Mw of 2625 g / mol.

[0149] Example 3 Oligomer #3 containing 2 wt% citric acid and 2 wt% 1,2,3,4-butanetetracarboxylic acid 1.219 moles of citric acid (2 wt% loading), 1 mole of 1,2,3,4-butanetetracarboxylic acid (2 wt% loading), 23.107 moles of bisphenol A diglycidyl ether, 11.524 moles of acrylic acid, 0.15 wt% of MeHQ as inhibitor and 0.35 wt% of BTEAC as catalyst were thoroughly mixed and heated to 90°C under air sparge. The remaining 27.735 moles of acrylic acid were metered into the mixture over a period of 1 hour to control the exotherm temperature below 125°C. The reaction was then carried out until the termination criteria of AV<2 mg KOH / gm and EV<5 mg KOH / gm were reached (approximately 6 hours). The final product was a clear light yellow viscous liquid with a viscosity of 22660 mPa·s (cP) at 65°C. The x:(y1+y2) ratio was 1:1.015. The y2:x ratio was 1:6.04.

[0150] The Brookfield viscosity of the sample was 22,660 mPa·s at 65°C and 7375 mPa·s at 75°C, indicating that branched molecules were produced. Gel permeation chromatography using polystyrene standards showed an Mn of 2406 g / mol and an Mw of 3486 g / mol.

[0151] Comparative Example 1 Two-step process, solvent-free reaction using citric acid and acrylic acid in a 1:3 ratio One mole of citric acid, three moles of bisphenol A diglycidyl ether (DER™ 331, Dow) and 0.7% mequinol (MeHQ) (Aldrich) as inhibitor were thoroughly mixed and heated to 90° C. under air sparge. 0.35% wt.% benzyltriethylammonium chloride (BTEAC) (Aldrich) as catalyst was added at 90° C. and the exotherm temperature was allowed to reach 120° C. The mixture was stirred at 120° C. for 30 minutes until most of the citric acid disappeared. Then, three moles of acrylic acid were metered into the mixture over a period of 30 minutes to control the exotherm temperature below 125° C. After all the acrylic acid was added, the mixture was continued to be stirred at 125° C. The viscosity of the mixture continued to increase and then reached the stopping criterion after half an hour when the mixture solidified into a mass. The material was insoluble in THF. This indicated that the material had too much crosslinking. The x:(y1+y2) ratio was 1:1. The y2:x ratio was 1:2.

[0152] Comparative Example 2 One-step process in toluene as solvent and citric acid and acrylic acid in a 1:3 molar ratio One mole of citric acid, three moles of bisphenol A diglycidyl ether (DER™ 331, Dow), three moles of acrylic acid, 0.3% mequinol (MeHQ) (Aldrich) as an inhibitor, and 40 wt% toluene (SECO) as a viscosity reducing solvent were thoroughly mixed and heated to 90° C. under air sparge. 0.4% wt.% benzyltriethylammonium chloride (BTEAC) (Aldrich) as a catalyst was added at 90° C. and the exotherm was allowed to reach 120° C. 15 minutes after all the citric acid had disappeared, a highly viscous material precipitated (phase separated from the solvent). This highly viscous material was insoluble in THF, thus indicating that it had too high a crosslinking level. The x:(y1+y2) ratio was 1:1. The y2:x ratio was 1:2.

[0153] Comparative Example 3 Fully branched 1,4 butanediol diglycidyl ether epoxy acrylate with 10.28 wt% citric acid in 40% toluene Citric acid (0.118 mol), 1,4-butanediol diglycidyl ether (0.353 mol) and acrylic acid (0.353 mol) in toluene (88.03 gm) as the solvent were reacted together using triphenylphosphine as the catalyst according to the procedure of Comparative Example 1. The resulting product was an unusable, non-viscous aggregate that could not be formed into a coating or film. The x:(y1+y2) ratio was 1:1.001. The y2:x ratio was 1:1.994.

[0154] Example 4 characteristics Application tests were performed on cured film samples for tensile properties and on cured coatings for other property tests. Comparative samples were made using a difunctional bisphenol-based epoxy acrylate that did not contain any branching (i.e., obtained with a dicarboxylic acid rather than a polycarboxylic acid bearing at least three carboxylic acid groups).

[0155] The tensile properties of the cured films are shown below for a blend of 48 wt% oligomer, 48 wt% difunctional monomer polyethylene glycol (600) dimethacrylate (SR252, Sartomer), and 4 wt% photoinitiator (PL 460, PL Industries), cured by UV radiation curing before testing. The data shows an increase in elasticity for the freshly prepared oligomer Examples 1, 2, and 3. This phenomenon shows an increase in toughness as indicated by an increase in the energy to break, as can be seen in Table 1.

[0156] The film tensile properties are shown in Table 1. TIFF2024536248000006.tif68170

[0157] Coatings were made by blending the oligomers synthesized from Examples 1, 2, and 3 with 57.6 wt% oligomer, 38.4 wt% tripropylene glycol diacrylate (SR306F, Sartomer), and 4 wt% photoinitiator (SpeedCure 73; hydroxyacetophenone type, Lambson), applied to aluminum panels, and cured under UV light. A series of tests were performed on these coatings, the results of which are shown in Table 2. TIFF2024536248000007.tif68170

[0158] Example 5 Aliphatic diepoxy with 2wt% citric acid and 2wt% 1,2,3,4-butanetetracarboxylic acid Citric acid (0.0328 mol), 1,2,3,4-butanetetracarboxylic acid (0.0269 mol), 0.15 wt% MeHQ as an inhibitor, 0.20 wt% Irgafos 126 and 1,4-butanediol diglycidyl ether (0.842 mol) were placed in a 1 L 4-neck round bottom flask equipped with an air sparge, stirrer, thermocouple, temperature controller, heating mantle, side arm / condenser and addition funnel. The mixture was heated to 80°C and then acrylic acid (1.4266 mol) was fed to the reaction mixture via the addition funnel over the course of 1 hour. Triphenylphosphine (0.8 wt%) as a catalyst was added simultaneously with the acrylic acid. The reaction was maintained below 115°C during the acrylic acid feed step. The reaction was then carried out at 115°C until the stopping criteria of AV<2mg KOH / gm and EV<5mg KOH / gm were reached (approximately 2 hours). The AV and EV were adjusted by adding 0.0344 moles of 1,4-butanediol diglycidyl ether. The Brookfield viscosity of the product was 2945 mPa.s at 25°C and 215 mPa.s at 60°C. GPC showed Mn=1512 gm / mol, Mw=2037 gm / mol. This material was readily formed into cured coatings and films. The x:(y1+y2) ratio was 1:0.932. The y2:x ratio was 1:8.51.

[0159] The tensile properties of the cured film made from the oligomer of Example 5, as a blend of 96 wt. % of the oligomer of Example 5 and 4 wt. % of a photoinitiator (PL 460, PL Industries), cured by UV radiation curing before tensile testing, are shown in Table 3 below. The tensile properties of the film are shown in Table 3. TIFF2024536248000008.tif43170

[0160] These results show that the branched oligomers from Examples 1, 2, 3 and 5 provided cured films and coatings with improved properties compared to the non-branched comparative examples in Table 2. The inventive samples were also able to be formed into films and coatings compared to Comparative Examples 1, 2 and 3 which were unable to be used.

[0161] Prophetic Example 1 Molecules containing 0.2wt% citric acid 0.1 moles of citric acid (0.2 wt% loading), 19.4 moles of bisphenol A diglycidyl ether (DER™ 331, Dow), 9 moles of acrylic acid (Beantown), 0.15 wt% of mequinol (MeHQ) (Aldrich) as inhibitor and 0.35% of benzyltriethylammonium chloride (BTEAC) (Aldrich) as catalyst are thoroughly mixed and heated to 90°C under air sparge. The remaining 29.5 moles of acrylic acid are metered into the mixture over 1 hour, controlling the exotherm temperature below 125°C. The reaction is then carried out at 125°C until the termination criteria of acid value (AV) < 2 mg KOH / gm and epoxy value (EV) < 5 mg KOH / gm are reached (approximately 6 hours). The AV or EV is adjusted by adding more acrylic acid or DER 331 as needed as the reaction proceeds. The final product is a clear, pale yellow, viscous liquid. The x:(y1+y2) ratio was 1:1. The y2:x ratio was 1:129.3.

[0162] Prophetic Example 2 Molecules containing 4wt% citric acid 2 moles of citric acid (4 wt% loading), 19.4 moles of bisphenol A diglycidyl ether (DER™ 331, Dow), 9 moles of acrylic acid (Beantown), 0.15 wt% of mequinol (MeHQ) (Aldrich) as inhibitor and 0.35 wt% of benzyltriethylammonium chloride (BTEAC) (Aldrich) as catalyst are thoroughly mixed and heated to 90°C under air sparge. The remaining 23.8 moles of acrylic acid are metered into the mixture over 1 hour, controlling the exotherm temperature below 125°C. The reaction is then carried out at 125°C until the termination criteria of acid value (AV) < 2 mg KOH / gm and epoxy value (EV) < 5 mg KOH / gm are reached (approximately 6 hours). The AV or EV is adjusted by adding more acrylic acid or DER 331 as needed as the reaction proceeds. The final product is a clear, pale yellow, viscous liquid. The x:(y1+y2) ratio was 1:1. The y2:x ratio was 1:6.47.

Claims

1. - x equivalents of component a) comprising at least one diepoxy; - y1 equivalents of component b) containing at least one unsaturated carboxylic acid; and y2 equivalents of component c) comprising at least one polycarboxylic acid carrying at least three carboxylic acid groups 1. A curable oligomer comprising the reaction product of: x is the number of moles of epoxy groups in component a), y1 is the number of moles of carboxylic acid groups in component b), and y2 is the number of moles of carboxylic acid groups in component c); the ratio of x:(y1+y2) is 1:1.1 to 1:0.90, in particular 1:1.09 to 1:0.91, more particularly 1:1.08 to 1:0.92; Curable oligomers.

2. 2. The curable oligomer of claim 1, wherein the ratio of y2:x is at most 1:4, in particular at most 1:4.5, and more particularly at most 1:

5.

3. 2. The curable oligomer of claim 1, wherein the ratio of y2:y1 can be at most 1:1.5, in particular at most 1:4, and more particularly at most 1:

6.

4. 2. The curable oligomer of claim 1, wherein component a) comprises at least one compound selected from aliphatic diepoxy, bisphenol-based diglycidyl ethers, and combinations thereof; in particular aliphatic diglycidyl ethers, bisphenol-A-diglycidyl ethers, and combinations thereof; more preferably bisphenol-A-diglycidyl ether.

5. 2. The curable oligomer of claim 1, wherein component a) comprises at least one aromatic diepoxy, preferably at least one aromatic diglycidyl ether, more preferably at least one bisphenol-based diglycidyl ether, even more preferably bisphenol-A-diglycidyl ether.

6. 2. The curable oligomer of claim 1, wherein component a) comprises at least one aliphatic diepoxy, preferably at least one aliphatic diglycidyl ether.

7. Component a) is 1,4-butanediol diglycidyl ether, 1,3-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, 1,2- or 1,4-cyclohexanedimethanol diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, bisphenol-A diglycidyl ether, bisphenol-AP diglycidyl ether, bisphenol-AF diglycidyl ether, bisphenol-B diglycidyl ether, bisphenol-BP diglycidyl ether, bisphenol-C diglycidyl ether, bisphenol-C2 diglycidyl ether, bisphenol-F ...

2. The curable oligomer of claim 1, comprising at least one compound selected from bisphenol-G-diglycidyl ether, bisphenol-M-diglycidyl ether, bisphenol-S-diglycidyl ether, bisphenol-P-diglycidyl ether, bisphenol-PH-diglycidyl ether, bisphenol-TMC-diglycidyl ether, bisphenol-Z-diglycidyl ether, dinitrobisphenol-A-diglycidyl ether, tetrabromobisphenol-A-diglycidyl ether and combinations thereof; in particular bisphenol-A-diglycidyl ether or 1,4-butanediol diglycidyl ether.

8. 10. The curable oligomer of claim 1, wherein component b) comprises an alpha-beta ethylenically unsaturated carboxylic acid.

9. 2. The curable oligomer of claim 1, wherein component b) comprises at least one compound selected from acrylic acid, methacrylic acid, ethacrylic acid, crotonic acid, isocrotonic acid, angelic acid, tiglic acid, senecioic acid, acryloyloxypropionic acid, maleic acid, fumaric acid or itaconic acid, or a combination thereof, in particular at least one of acrylic acid or methacrylic acid.

10. 10. The curable oligomer of claim 1, wherein component c) comprises a carboxylic acid bearing at least four carboxylic acid groups.

11. 10. The curable oligomer of claim 1, wherein component c) comprises a mixture of at least one tricarboxylic acid and at least one tetracarboxylic acid.

12. Component c) is citric acid; isocitric acid; 1,2,3-propanetricarboxylic acid; 1,2,4-butanetricarboxylic acid; 1,2,3,4 butanetetracarboxylic acid; 1,2,3,4-cyclobutanetetracarboxylic acid; 1,2,3,4-cyclopentanetetracarboxylic acid; 1,3,5-cyclohexanetricarboxylic acid; 1,2,4,5-cyclohexanetetracarboxylic acid; 1,3,5 benzenetricarboxylic acid; 1,2,4-benzenetricarboxylic acid; 1,2,4,5-benzenetetracarboxylic acid; 1,3,5,7-adamantanetetracarboxylic acid; 10. The curable oligomer of claim 1 comprising at least one compound selected from 1,3,5,7 adamantanetetrabenzoic acid and combinations thereof.

13. 10. The curable oligomer of claim 1, wherein the total weight of residues derived from the reaction of components a), b) and c) accounts for at least 90%, at least 95%, at least 98%, at least 99%, at least 99.5%, at least 99.9%, at least 99.99% or even 100% of the total weight of the curable oligomer.

14. A curable composition comprising the curable oligomer of claim 1 and at least one inhibitor and / or at least one ethylenically unsaturated compound other than the curable oligomer.

15. 1. A method for preparing a curable oligomer, comprising: - x equivalents of component a) comprising at least one diepoxy; - y2 equivalents of component c) comprising at least one polycarboxylic acid carrying at least three carboxylic acid groups; and optionally z 1 equivalents of component b) comprising at least one unsaturated carboxylic acid reacting a mixture comprising: then reacting the epoxy-capped prepolymer with z2 equivalents of component b) comprising at least one unsaturated carboxylic acid; Including, z1+z2=y1, A process wherein x is the number of moles of epoxy groups in component a), y1 is the number of moles of carboxylic acid groups in component b), and y2 is the number of moles of carboxylic acid groups in component c).

16. 16. The method according to claim 15, wherein the ratio of x:(y1+y2) is from 1:1.1 to 1:0.90, in particular from 1:1.09 to 1:0.91, more particularly from 1:1.08 to 1:0.

92.

17. 1. A method for preparing a curable oligomer, the method comprising: - x equivalents of component a) comprising at least one diepoxy; - y1 equivalents of component b) containing at least one unsaturated carboxylic acid; and y2 equivalents of component c) comprising at least one polycarboxylic acid carrying at least three carboxylic acid groups reacting a mixture comprising: wherein x is the number of moles of epoxy groups in component a), y1 is the number of moles of carboxylic acid groups in component b), and y2 is the number of moles of carboxylic acid groups in component c), and the ratio of x:(y1+y2) is from 1:1.1 to 1:0.90, particularly from 1:1.09 to 1:0.91, and more particularly from 1:1.08 to 1:0.

92.

18. 18. The method according to any one of claims 15 to 17, wherein the ratio of y2:x is at most 1:4, in particular at most 1:4.5, more particularly at most 1:

5.

19. 18. The method of any one of claims 15 to 17, wherein component a) comprises at least one compound selected from aliphatic diepoxy, bisphenol-based diglycidyl ethers and combinations thereof; in particular aliphatic diglycidyl ethers, bisphenol-A-diglycidyl ethers and combinations thereof; more preferably bisphenol-A-diglycidyl ether.