Multi(METH)acrylate-functionalized oligomer as well as method for preparing and using such oligomer

Abstract

To provide a multi(meth)acrylate-functionalized oligomer, a method for preparing such an oligomer, an oligomer-based curable composition, a method for using the oligomer, as well as a composition containing a cured oligomer and an article.SOLUTION: Multi(meth)acrylate-functionalized oligomers have a polyurethane main chain, multiple (meth)acrylate groups as pendants on the polyurethane main chain, and one or more terminal (meth)acrylate groups. The oligomer comprises: a) at least one multi(meth)acrylate-functionalized segment having at least two pendant (meth)acrylate groups, b) a urethane-containing segment, c) at least one terminal capping segment having at least one (meth)acrylate group, and optionally d) a chain extension segment (e.g., a non-polymeric aliphatic segment, a polyether-containing segment, a polyester-containing segment, a polydiene-containing segment, a polycarbonate-containing segment, or a polyorganosiloxane-containing segment). At least one multi(meth)acrylate-functionalized segment is located at a pendant position, and at least one (meth)acrylate group is present at one or more terminal positions of the oligomer. The multi(meth)acrylate-functionalized oligomer is useful in compositions that can provide polymeric articles cured by photopolymerization or the like. The oligomer can be a reaction product of a diisocyanate, a diol or triol compound each containing two or three (meth)acrylate groups, and a terminal capping compound.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to multi(meth)acrylate-functionalized oligomers, methods for preparing such oligomers, curable compositions based on the oligomers, methods for using the oligomers, and compositions and articles containing the oligomers in cured form. [Background technology]

[0002] Many different types of (meth)acrylate-functionalized oligomers are known in the art, including (meth)acrylate-functionalized urethane oligomers characterized by one or more (meth)acrylate functional groups substituted at the end of the polyurethane oligomer backbone. (Meth)acrylate-functionalized urethane oligomers can be synthesized by a variety of methods, including, for example, reacting a polymer polyol, such as a polyether polyol, polycarbonate polyol, or polyester polyol, with an excess of polyisocyanate to form an isocyanate-functionalized urethane prepolymer, and then reacting the isocyanate-functionalized urethane prepolymer with a reactant, such as hydroxyethyl (meth)acrylate, that contains both isocyanate-reactive functionality and (meth)acrylate functionality. Such (meth)acrylate-functionalized urethane oligomers have been found to be useful components of compositions that can be cured (polymerized) using UV radiation or other methods to form cured compositions that function as coatings, adhesives, sealants, additive manufacturing resins, molding resins, and the like.

[0003] Conventional terminally functionalized ("telechelic") (meth)acrylated urethane oligomers are a versatile class of reactive materials, but suffer from certain limitations due to their molecular structure. In particular, because the reactive (meth)acrylate functionality is located at the end of the oligomer, the level of (meth)acrylate functionality when such oligomers are cured, and the resulting crosslink density, are inversely proportional to the molecular weight of the oligomer's backbone. Higher molecular weight backbones inherently result in cured materials with lower crosslink densities, while lower molecular weight backbones necessarily result in higher crosslink densities. It would be beneficial to decouple this relationship and achieve a combination of cured properties that are currently difficult to obtain through the use of conventional telechelic oligomers, thereby making curable compositions more tunable. Furthermore, it is known that localized functionality, such as that produced by the use of telechelic oligomers, can create heterogeneous crosslinked networks. Such "inhomogeneous" networks can adversely affect the properties of the cured material, for example, imparting brittleness and / or high water vapor permeability. The development of oligomers that favor the formation of more homogeneous crosslinks is therefore considered to be of significant interest. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US Patent Application Publication No. 2017 / 0158803 [Patent Document 2] U.S. Patent No. 6,562,881 [Patent Document 3] U.S. Patent No. 5,219,896 [Patent Document 4] U.S. Patent No. 9,676,963 [Patent Document 5] International Publication No. 2014 / 126830 [Patent Document 6] International Publication No. 2014 / 126834 [Patent Document 7] International Publication No. 2014 / 126837 [Non-patent literature]

[0005] [Non-Patent Document 1] Charles Hansen, "Hansen Solubility Parameters: A User's Handbook", 2nd edition (2007), Boca Raton, Fla.: CRC Press., ISBN 978-O-8493-7248-3 [Non-patent document 2] Tumbleston et al., "Continuous Liquid Interface Production of 3D Objects," Science, Vol. 347, No. 6228, pp. 1349-1352 (March 20, 2015) [Non-patent document 3] OCDE (1996), Test No. 118: Determination of the Number-Average Molecular Weight and the Molecular Weight Distribution of Polymers using Gel Permeation Chromatography, OECD Guidelines for the Testing of Chemicals, Section 1, Editions OCDE, Paris Summary of the Invention [Means for solving the problem]

[0006] The present invention provides oligomers having multiple (meth)acrylate functional groups located both along the backbone and at terminal positions of the oligomer. Specifically, such oligomers have a polyurethane backbone, multiple (meth)acrylate functional groups pendant to the polyurethane backbone, and one or more terminal (meth)acrylate functional groups. The oligomers include: a) at least one multi(meth)acrylate-functionalized segment having at least two pendant (meth)acrylate groups; b) a urethane-containing segment; c) at least one end-capping segment having at least one (meth)acrylate group; and, optionally, d) at least one chain-extending segment (containing at most one (meth)acrylate functional group), such as a non-polymeric aliphatic segment or a polymer-containing segment selected from the group consisting of a polyether-containing segment, a polyester-containing segment, a polydiene-containing segment, a polycarbonate-containing segment, and a polyorganosiloxane-containing segment. At least one multi(meth)acrylate-functionalized segment is located at a position along the polyurethane backbone of the oligomer that is different from the terminal position of the oligomer, and at least one (meth)acrylate functional group is present at one or more terminal positions of the oligomer. Oligomers according to the present invention allow the crosslink density and resulting mechanical properties of cured compositions prepared using such oligomers to be flexibly tailored by decoupling the oligomer's curable functionality level and position from the backbone molecular weight. Reactive oligomers of the present invention containing both pendant (meth)acrylate and telechelic (meth)acrylate functional groups can be cured to produce more homogeneously crosslinked materials, thereby avoiding or mitigating the aforementioned drawbacks sometimes encountered with the "cluster" crosslinking characteristics of conventional telechelic oligomers.

[0007] Multi(meth)acrylate-functionalized oligomers according to embodiments of the present invention may be the reaction product of reactants including: a) at least one diisocyanate; b) at least one diol compound having at least two (meth)acrylate functional groups or at least one triol compound having at least three (meth)acrylate functional groups, or a mixture thereof; c) at least one end-capping compound having one isocyanate-reactive hydroxyl group and at least one (meth)acrylate functional group; and, optionally, d) at least one chain-extending diol having either zero or at most one (meth)acrylate functional group, and which may be a non-polymeric diol (e.g., a non-polymeric aliphatic diol) and / or a polymeric diol, such as a polymeric diol selected from the group consisting of polyether polyols, polyester polyols, polydiene polyols, polycarbonate polyols, and polyorganosiloxane polyols.

[0008] Also provided by the present invention is a method for making a multi(meth)acrylate-functionalized oligomer having a polyurethane backbone, a plurality of (meth)acrylate functional groups pendant to the polyurethane backbone, and one or more terminal (meth)acrylate functional groups. Such a method comprises reacting a) at least one diisocyanate, b) at least one diol compound having at least two (meth)acrylate functional groups or at least one triol compound having at least three (meth)acrylate functional groups, or a mixture thereof, c) at least one end-capping compound having at least one hydroxyl group reactive with isocyanates and at least one (meth)acrylate functional group, and optionally d) at least one chain-extending diol (which has no (meth)acrylate functional groups or at most one (meth)acrylate functional group and can be a non-polymeric diol and / or a polymeric diol, such as a polyether polyol, polyester polyol, polydiene polyol, polycarbonate polyol, or polyorganosiloxane polyol). These components can be reacted together all at once or in different sequential steps, which will be described in more detail below.

[0009] Also provided by the present invention is a curable composition comprising at least one multi(meth)acrylate-functionalized oligomer according to the present invention and at least one of a) a photoinitiator or b) a curable compound other than a multi(meth)acrylate-functionalized oligomer according to the present invention.

[0010] The multi(meth)acrylate-functionalized oligomers of the present invention, and curable compositions containing such oligomers, can be cured by a variety of mechanisms, including photocuring, to provide cured compositions with useful properties such as improved tensile strength. The multi(meth)acrylate-functionalized oligomers can be formulated with other reactive components and other additives to provide curable compositions that can be utilized as curable coatings, adhesives, sealants, additive modeling resins, and the like. DETAILED DESCRIPTION OF THE INVENTION

[0011] <Definition> In this application, the term "including" refers to a singular noun and means "including one or more."

[0012] Unless otherwise stated, weight percent of a compound or composition is expressed based on the weight of the respective compound in the composition.

[0013] The term "(meth)acrylate functional group" refers to either an acrylate functional group (-O-C(=O)-CH=CH2) or a methacrylate functional group (-O-C(=O)-C(CH3)=CH2). When not followed by the phrase "functional group," the term "(meth)acrylate" refers to a compound containing at least one acrylate functional group per molecule or at least one methacrylate functional group per molecule. "(Meth)acrylate" can also refer to a chemical compound having both at least one acrylate functional group and at least one methacrylate functional group. "Functionality" and "functionality" refer to the number of (meth)acrylate functional groups per molecule. It does not refer to any other functional groups other than (meth)acrylate functional groups unless explicitly stated. For example, a difunctional monomer is understood to mean a monomer having two (meth)acrylate functional groups per molecule. On the other hand, a trifunctional alcohol is understood to mean a compound having three hydroxy groups per molecule and no (meth)acrylate groups. Without further clarification, "monomer" and "oligomer" are understood to mean (meth)acrylate monomers and (meth)acrylate oligomers, respectively.

[0014] The term "urethane (meth)acrylate" refers to a compound containing at least one urethane bond and at least one (meth)acrylate functional group. Such compounds may also be referred to as urethane (meth)acrylate oligomers. The term "urethane bond" refers to an -NH-C(=O)-O- or -OC(=O)-NH- bond.

[0015] The term "polyester" refers to a compound or moiety having more than one ester bond. The term "ester bond" refers to a -C(=O)-O- or -OC(=O)- bond.

[0016] The term "polyether" means a compound or moiety having more than one ether linkage. The term "ether linkage" means an --O-- linkage.

[0017] The term "polycarbonate" refers to a compound or moiety having more than one carbonate bond. The term "carbonate bond" refers to an -OC(=O)-O- bond.

[0018] The term "polydiene" means a compound or moiety obtained by polymerizing conjugated dienes.

[0019] The term "polyorganosiloxane" means a compound or moiety having more than one siloxane bond. The term "siloxane bond" means an -Si-O- or -O-Si- bond.

[0020] The term "diol" refers to a compound having two hydroxy groups.

[0021] The term "triol" refers to a compound having three hydroxy groups.

[0022] The term "hydroxy" refers to an -OH group.

[0023] The term "diisocyanate" means a compound having two isocyanate groups.

[0024] The term "isocyanate group" means a -N=C=O group.

[0025] The term "polyoxyethylene" means a compound or moiety having more than one oxyethylene unit. The term "oxyethylene unit" means a -(O-CH-CH)- unit.

[0026] The term "polyoxypropylene" refers to a compound or moiety having more than one oxypropylene unit. The term "oxypropylene unit" refers to an -(O-CH(CH)-CH)- and / or -(O-CH-CH(CH))- unit.

[0027] The term "polyoxytetramethylene" means a compound or moiety having more than one oxytetramethylene unit. The term "oxytetramethylene unit" means a -(O-CH-CH-CH-CH)- unit.

[0028] The terms "organo," "hydrocarbon," or "hydrocarbyl" refer to a monovalent or polyvalent (divalent, trivalent, tetravalent, pentavalent, hexavalent) group containing carbon and hydrogen atoms. It may be linear or branched, saturated or unsaturated, cyclic or alicyclic, aliphatic, aromatic, or araliphatic. It may contain 1 to 200 carbon atoms. C2-C12 hydrocarbyl refers to a hydrocarbyl having 2 to 12 carbon atoms. It may be optionally substituted. In addition to carbon and hydrogen atoms, it may contain one or more heteroatoms selected from O, N, S, Si, and mixtures thereof.

[0029] The term "aliphatic" refers to a non-aromatic compound or moiety that may be optionally substituted. It may be linear or branched, saturated or unsaturated. It may be acyclic or contain one or more alicyclic (i.e., non-aromatic) rings. It may contain one or more heteroatoms, such as O, N, S, and / or halogens.

[0030] The term "aromatic" refers to an optionally substituted compound or moiety containing an aromatic ring, which means that it respects the Hückel aromaticity rules, and in particular refers to compounds containing a phenyl group, which may contain one or more heteroatoms such as O, N, S and / or halogens.

[0031] The term "araliphatic" refers to optionally substituted compounds or moieties that contain aliphatic and aromatic moieties, which may contain one or more heteroatoms such as O, N, S, and / or halogens.

[0032] The term "alkylene" refers to a group of formula C n H 2n+2 "C2-C4 dialkylene" refers to a divalent moiety obtained by removing two hydrogen groups from an alkane of the formula (I). It may be linear or branched. "C2-C4 dialkylene" refers to a dialkylene having 2 to 4 carbon atoms. Examples of suitable dialkylenes are ethylene, propylene, isopropylene, butylene, and isobutylene.

[0033] The term "optionally substituted" means a compound that is optionally substituted with one or more groups selected from alkyl, cycloalkyl, aryl, heteroaryl, alkoxy, alkylaryl, haloalkyl, hydroxy, halogen, isocyanate, nitrile, amine, carboxylic acid, -C(=O)-R'-C(=O)-OR', -C(=O)NH-R', -NH-C(=O)R', -OC(=O)-NH-R', -NH-C(=O)-O-R', -C(=O)-OC(=O)-R', and -SO2-NH-R', where each R' is independently an optionally substituted group selected from alkyl, aryl, and alkylaryl.

[0034] The term "alkyl" refers to a group of the formula -C n H 2n+1 "C1-C6 alkyl" means an alkyl having 1 to 20 carbon atoms. Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, and hexyl.

[0035] The term "cycloalkyl" means a monovalent saturated alicyclic hydrocarbon moiety comprising a ring. Examples of cycloalkyl groups include cyclopentyl, cyclohexyl, and isobornyl.

[0036] The term "aryl" means an aromatic hydrocarbon group.

[0037] The term "phenylene" refers to a polyvalent radical obtained by removing two or more hydrogen radicals from substituted or unsubstituted benzene.

[0038] The term "heteroaryl" refers to an aromatic group that contains heteroatoms such as O, N, S, and mixtures thereof.

[0039] The term "alkoxy" means a group of the formula --O-alkyl.

[0040] The term "alkylaryl" means an alkyl substituted with an aryl group. An example of an alkylaryl group is benzyl (-CH-phenyl).

[0041] The term "haloalkyl" means an alkyl substituted with one or more halogen atoms.

[0042] The term "halogen" means an atom selected from Cl, Br, and I.

[0043] The term "ethylenically unsaturated compound" refers to a compound containing 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 contained in a group selected from acrylate (including cyanoacrylate), methacrylate, acrylamide, methacrylamide, styrene, maleate, fumarate, itaconate, allyl, propenyl, vinyl, and combinations thereof, preferably a group selected from acrylate, methacrylate, and vinyl, more preferably a group selected from acrylate and methacrylate. The carbon-carbon double bond of a phenyl ring is not considered to be a polymerizable carbon-carbon double bond.

[0044] As used herein, the term "alkoxylated" refers to compounds in which one or more epoxides, such as ethylene oxide and / or propylene oxide, react with active hydrogen-containing groups (e.g., hydroxy groups) of a base compound, such as a polyol, to form one or more oxyalkylene moieties. For example, 1 to 25 moles of epoxide can be reacted per mole of base compound.

[0045] <Multi(meth)acrylate functionalized oligomer> Multi(meth)acrylate-functionalized oligomers according to aspects of the present invention can be characterized as oligomers having a polyurethane backbone, multiple (meth)acrylate functional groups pendant to the polyurethane backbone, and one or more terminal (meth)acrylate functional groups. Thus, the oligomer has multiple (meth)acrylate functional groups both along its backbone and at the termini (ends) of the oligomer. As used herein, the term "(meth)acrylate" refers to both acrylate and methacrylate functional groups. According to some embodiments, each of the (meth)acrylate functional groups within an oligomer molecule may be of the same type (i.e., all of the (meth)acrylate functional groups in the oligomer may be acrylate functional groups, or all of the (meth)acrylate functional groups in the oligomer may be methacrylate functional groups). The oligomer may have both acrylate and methacrylate functional groups. For example, a terminal (meth)acrylate functional group may be an acrylate functional group, while a (meth)acrylate functional group pendant to the polyurethane backbone may be a methacrylate functional group, or vice versa.

[0046] Oligomers according to the present invention have at least three (meth)acrylate functional groups per molecule (at least two of which are associated with multi(meth)acrylate-functionalized segments and at least one of which is associated with a terminal end of the oligomer). However, in embodiments of the present invention, the oligomer can have a total of four, five, six, seven, eight, nine, ten, or more (meth)acrylate functional groups per molecule. The number of (meth)acrylate functional groups per molecule can be readily controlled or varied as desired, for example, by varying the number average molecular weight of the oligomer, or by varying the number of multi(meth)acrylate-functionalized segments in the oligomer, and / or by varying the types of reactants used to prepare the oligomer, as described in more detail below.

[0047] According to some embodiments, the multi(meth)acrylate-functionalized oligomer has a linear structure (in which case the (meth)acrylate functionality associated with the multi(meth)acrylate-functionalized segment is not considered branched), however, in other embodiments, the oligomer may have a star, comb, radial, or branched structure.

[0048] The multi(meth)acrylate-functionalized oligomer may comprise, consist essentially of, or consist of: a) at least one multi(meth)acrylate-functionalized segment having at least two pendant (meth)acrylate groups; b) a urethane-containing segment; c) at least one end-capping segment having at least one (meth)acrylate group; and, optionally, d) at least one chain-extension segment. The chain-extension segment(s) may be one or more non-polymeric and / or polymeric segments. Such optional chain-extension segments are distinguished from the multi(meth)acrylate-functionalized segment(s) in that they contain no more than one (meth)acrylate functional group per segment (i.e., either no (meth)acrylate functional groups or at most one (meth)acrylate functional group). They are also distinguished from the urethane-containing segments in that they lack urethane linkages. If present, the polymeric segment(s) can be selected from the group consisting of, for example, polyether-containing segments, polyester-containing segments, polydiene-containing segments, polycarbonate-containing segments, and polyorganosiloxane-containing segments. If present, the non-polymeric segments can be aliphatic, aromatic, or araliphatic (having both aliphatic and aromatic moieties). Thus, in some embodiments, the oligomer has one or more such chain-extending segments, while in other embodiments, the oligomer does not have any such chain-extending segments. The oligomers of the present invention are characterized in that at least one multi(meth)acrylate-functionalized segment is located at a position along the polyurethane backbone of the oligomer (i.e., pendant to the polyurethane backbone, as opposed to being at a terminal position), and at least one (meth)acrylate functional group is present at one or more terminal positions of the oligomer.

[0049] The number average molecular weight of the multi(meth)acrylate-functionalized oligomer can be modified as desired to impart certain characteristics to the oligomer itself and to cured compositions prepared from the oligomer. Generally speaking, if the oligomer contains at least one polymer-containing segment, the number average molecular weight will typically be somewhat higher. For example, the oligomer may contain one or more polymer-containing segments (i.e., chain extension segments that are polymer segments) and have a number average molecular weight of 3,000 g / mol to 20,000 g / mol. An oligomer that does not contain one or more polymer-containing segments may have a number average molecular weight of, for example, 500 g / mol to 5,000 g / mol. Herein, number average and weight average molecular weight values ​​were obtained using an Agilent 1260 GPC equipped with a refractive index detector and polystyrene calibration standards.

[0050] According to some embodiments of the present invention, the chain extension segments (e.g., non-polymeric segments and / or polymeric segments) and the multi(meth)acrylate-functionalized segments can be present in the oligomer in a molar ratio of 0:1 to 10:1 (e.g., 0.1:1 to 10:1).

[0051] In embodiments in which one or more chain extender segments are present, the chain extender segments and the multi(meth)acrylate-functionalized segments may be randomly positioned along the polyurethane backbone and linked together by urethane-containing segments. By varying the synthetic method used to prepare the oligomer, it is also possible to tailor the oligomer to a more desirable structure. For example, the chain extender segment(s) may be clustered near the center of the polyurethane backbone, with the multi(meth)acrylate-functionalized segments positioned toward each end of the polyurethane backbone, or vice versa.

[0052] A urethane-containing segment is a segment having a urethane functionality (i.e., —OC(═O)—NH—) and generally functions to link together multi(meth)acrylate-functionalized segments and / or chain-extending segments (if such chain-extending segments are present in the oligomer). For example, a urethane-containing segment may link two multi(meth)acrylate-functionalized segments together, or two chain-extending segments together, or a multi(meth)acrylate-functionalized segment with a chain-extending segment. A urethane-containing segment may also be present at one or more termini of an oligomer to provide a means for linking the terminal (meth)acrylate functionality to the polyurethane backbone of the oligomer.

[0053] The urethane-containing segment may be disposed between multiple multi(meth)acrylate-functionalized segments to link them together. As used herein, "segment L may be disposed between segment M to link them together" means that both sides of segment L are directly bonded to segment M to form the sequence -MLM-. The urethane-containing segment may be disposed between a multi(meth)acrylate-functionalized segment and a chain-extension segment to link them together. As used herein, "segment L may be disposed between segment M and segment N to link them together" means that one side of segment L is directly bonded to segment M and the other side of segment L is directly bonded to segment N to form the sequence -MLN-. The urethane-containing segment may be disposed between an end-capping segment and a multi(meth)acrylate-functionalized segment to link them together, and / or, if one or more chain-extension segments are present, between the end-capping segment and the chain-extension segment to link them together. The chain-extension segment and the multi(meth)acrylate-functionalized segment may be disposed randomly along the polyurethane backbone and linked together by the urethane-containing segment.

[0054] Representative, non-limiting examples of multi(meth)acrylate-functionalized oligomers according to the present invention can be represented diagrammatically as follows:

[0055] [ka]

[0056] In these, MMFS = multi(meth)acrylate functionalized segment, UCS = urethane-containing segment, ECS = end-capping segment, and CES = chain-extending segment.

[0057] Typically, due to the way in which they are generally synthesized, oligomers according to the present invention will be obtained as mixtures of oligomers having different molecular weight ranges, varying numbers of multi(meth)acrylate-functionalized segments, urethane-containing segments, end-capping segments, and optionally chain-extending segments, as well as different arrangements of such segments.

[0058] In some embodiments of the present invention, the urethane-containing segment has formula (I):

[0059] [ka]

[0060] [In the formula, R 1 is a divalent organo (e.g., hydrocarbyl) group] The hydrocarbyl group can be an aliphatic group (which can be linear, branched, or cyclic), an aromatic group, or an araliphatic group (which contains both aliphatic and aromatic moieties). In addition to carbon and hydrogen atoms, the organic group can also contain one or more heteroatoms (e.g., O, N, halogens).

[0061] Examples of urethane-containing segments include tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), methylcyclohexane-2,4-diisocyanate, methylcyclohexane-2,6-diisocyanate, 1,3-(isocyanatomethyl)cyclohexane, isophorone diisocyanate, and trimethyl Hexamethylene diisocyanate, dimer acid diisocyanate, dianisidine diisocyanate, phenyl diisocyanate, halogenated phenyl diisocyanate, methylene diisocyanate, ethylene diisocyanate, butylene diisocyanate, propylene diisocyanate, octadecylene diisocyanate, 1,5-naphthalene diisocyanate, polymethylene polyphenylene diisocyanate, tolylene diisocyanate polymer (polymeric tolylene diisocyanate), diphenylmethane diisocyanate polymer (poly Poly(hexamethylene diisocyanate), 3-phenyl-2-ethylene diisocyanate, cumene-2,4-diisocyanate, 4-methoxy-1,3-phenylene diisocyanate, 4-ethoxy-1,3-phenylene diisocyanate, 2,4'-diisocyanate diphenyl ether, 5,6-dimethyl-1,3-phenylene diisocyanate, 4,4'-diisocyanate diphenyl ether, benzidine diisocyanate , 9,10-anthracene diisocyanate, 4,4'-diisocyanate benzyl, 3,3'-dimethyl-4,4'-diisocyanate diphenylmethane, 2,6'-dimethyl-4,4'-diisocyanate diphenyl, 3,3'-dimethoxy-4,4'-diisocyanate diphenyl, 1,4-anthracene diisocyanate, phenylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,10-decamethylene diisocyanate, 1,3-cyclohexylene diisocyanate, 4,R may comprise the residue of a diisocyanate selected from the group consisting of 4'-methylene-bis(cyclohexyl isocyanate), and combinations thereof. 1 It is also possible for t to be the residue of a higher functionality polyisocyanate, such as a triisocyanate (e.g., triphenylmethane triisocyanate, 2,4,6-tolylene triisocyanate, 2,4,4'-triisocyanatodiphenyl ether), although care should be taken when using such higher functionality polyisocyanates to avoid problems with gelation of the oligomer.

[0062] According to some embodiments of the present invention, the oligomer may comprise one or more multi(meth)acrylate-functionalized segments corresponding to the following formula (IIa):

[0063] [ka]

[0064] In the formula, R 2 and R 4 are the same or different, -CH2-OC(=O)-CR 5 =CH2(wherein, R 5 is H or CH3), and R 3 is a divalent organo moiety. For example, R 3 -R 3’ -or-CH2-OR 3’ -O-CH2-(wherein, R 3’ R may be a divalent hydrocarbon group. Suitable divalent hydrocarbon groups include aliphatic divalent hydrocarbon groups (which can be linear, branched, or cyclic in structure), aromatic divalent hydrocarbon groups, and araliphatic divalent hydrocarbon groups. 3 and R 3’ may also contain, in addition to carbon and hydrogen atoms, one or more heteroatoms (e.g., N, O, S, halogens). Representative divalent hydrocarbon groups include, but are not limited to, one of the groups shown below.

[0065] [ka]

[0066] wherein m is an integer of at least 2 (e.g., 2 to 10); m' and m'' are independently an integer of 0 to 20; each Alk is independently a C2-C4 alkylene, typically ethylene or 1,2-propylene, or 1,4-butylene; each Ar is the same or different and is a substituted or unsubstituted aromatic group (e.g., a substituted or unsubstituted phenylene group); and R 8 and R 9 are the same or different and are selected from the group consisting of H, aryl, and alkyl.

[0067] According to some embodiments of the present invention, the oligomer may include one or more multi(meth)acrylate-functionalized segments corresponding to formula (IIb):

[0068] [ka]

[0069] In the formula, R 2 and R 4 and R 10 are the same or different, -CH2-OC(=O)-CR 5 =CH2(wherein, R 5 is H or CH3), and R 3 is a trivalent organic group, and the wavy line represents the point of attachment to another segment of the oligomer, particularly the urethane-containing segment. For example, R 3 -R 3’ -or

[0070] [ka]

[0071] (In the formula, R 3’ is a trivalent hydrocarbon group) may be. Suitable trivalent hydrocarbon groups include aliphatic trivalent hydrocarbon groups (which can be linear, branched, or cyclic in structure), aromatic trivalent hydrocarbon groups, and araliphatic trivalent hydrocarbon groups. 3 and R 3’ may also contain, in addition to carbon and hydrogen atoms, one or more heteroatoms (eg, N, O, S, halogens). Representative trivalent hydrocarbon groups include, but are not limited to, one of the following groups:

[0072] [ka]

[0073] In the formula, p, p', and p'' are independently an integer of 0 to 10, q, q', and q'' are independently an integer of 0 to 20; each Alk is independently a C2-C4 alkylene, typically ethylene or 1,2-propylene or 1,4-butylene; each Ar is the same or different and is a substituted or unsubstituted aromatic moiety (e.g., a substituted or unsubstituted phenylene moiety); R 8 and R 9 are the same or different and are selected from the group consisting of H and alkyl.

[0074] As previously mentioned, the oligomer may optionally include at least one polymer segment as a chain extending segment. The polymer segment(s) may be selected from the group consisting of polyether-containing segments, polyester-containing segments, polydiene-containing segments, polycarbonate-containing segments, and polyorganosiloxane-containing segments. Although different types of polymer segments may be present in the oligomer, according to some embodiments, the oligomer includes only one type of polymer segment.

[0075] The polymer segment may correspond to formula (III):

[0076] [ka]

[0077] In the formula, R 6 is a divalent polymer moiety, such as a divalent polyether group, a divalent polyester group, a divalent polydiene group, a divalent polycarbonate group, or a divalent polyorganosiloxane group. According to some embodiments of the present invention, the divalent polymeric moiety can have a number average molecular weight of from 200 g / mol to 6000 g / mol.

[0078] Suitable divalent polyether groups include aliphatic divalent polyether groups, such as divalent polyoxyethylene groups, divalent polyoxypropylene groups, divalent polyoxyethylene / oxypropylene groups, and divalent polyoxytetramethylene groups.

[0079] The polymer segment may be the residue of a dihydroxy-functionalized polymer, such as a polyether diol, polyester diol, polydiene diol, polycarbonate diol, or polyorganosiloxane diol. Typically, the hydroxyl groups in such polymers are terminal and are primary and secondary hydroxyl groups, which react readily with the diisocyanates used to make the oligomers.

[0080] As mentioned above, the oligomer may optionally include at least one non-polymeric segment as a chain extension segment. As used herein, the term "non-polymeric" refers to a material containing up to four repeating monomer units (e.g., a segment derived from ethylene glycol having one oxyethylene unit and a segment derived from triethylene glycol having three repeating oxyethylene units are both considered non-polymeric). Although different types of non-polymeric segments may be present in an oligomer, according to some embodiments, the oligomer includes only one type of non-polymeric segment.

[0081] The non-polymeric segment may correspond to formula (IIIa) below:

[0082] [ka]

[0083] (In the formula, R 6a is a divalent aliphatic, aromatic, or araliphatic group, such as a divalent C2-C30 aliphatic group, which may be linear or branched, or may contain one or more alicyclic rings. The divalent aliphatic, aromatic, or araliphatic group may have one or more heteroatoms, such as O, N, S, and / or halogen. Such non-polymeric segments are distinguished from multi(meth)acrylate-functionalized segments in that they have at most one (meth)acrylate functional group. They are distinguished from end-capping segments in that they are divalent rather than monovalent. Furthermore, non-polymeric segments differ from urethane-containing segments in that they do not contain urethane groups, which function as linking groups between multiple segments in the oligomer.

[0084] The non-polymeric segments may be non-polymeric aliphatic segments that are residues of aliphatic diols (linear, branched, or containing cyclic structures), such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, 1,3-butanediol, 2-butyl-2-ethyl-1,3-propanediol, 2,4-diethyl-1,5-pentanediol, and the like, and short-chain oligomers thereof (containing up to four oxyalkylene repeat units). Typically, the hydroxyl groups in such aliphatic diols are primary or secondary hydroxyl groups, which readily react with the diisocyanates used to prepare the oligomers.

[0085] At least one end cap segment present in the oligomer may have a structure corresponding to formula (IV):

[0086] [ka]

[0087] In the formula, R 7 is an n+1 valent organic group, and R 8 is H or CH3, and n is an integer of 1 to 5. Each end of the oligomer may have an end cap segment corresponding to formula (IV):7 can be the residue of a polyol, such as a diol, triol, or tetraol (e.g., ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, trimethylolpropane, triethylolpropane, pentaerythritol, di-pentaerythritol, di-trimethylolpropane). In some embodiments of the present invention, R 7 is -CH2CH2- or -(CH2)5-C(=O)-[O-(CH2)5-C(=O)] x -O-CH2-CH2- (wherein x is an integer of 0 to 9, and n=1). When n=1, R 7 =CH2CH2, and R 8 =H, and such end cap segments can be derived from hydroxyethyl acrylate. When n=1, R 7 =-(CH2)5-C(=O)-[O-(CH2)5-C(=O)] x -O-CH2-CH2-, and R 8 =H, and such end-capping segments can be derived from caprolactone-modified hydroxyethyl acrylate.

[0088] An oligomer according to the invention may be composed of one or more units of formula (A2).

[0089] [ka]

[0090] In the formula, R 1 is a divalent hydrocarbon group, and R 2 and R 4 are the same or different, -CH2-OC(=O)-CR 5 =CH2(wherein, R 5 is H or CH3), and R 3 is a divalent organic group. Thus, the unit of formula (A2) can be the urethane-containing segment described above coupled to the multi(meth)acrylate-functionalized segment described above.

[0091] In addition to one or more units of formula (A2), the oligomer may optionally additionally comprise one or more units of formula (B).

[0092] [ka]

[0093] In the formula, R 1 is a divalent hydrocarbon group, and R 6 is a divalent polymer moiety selected from the group consisting of a divalent polyether group, a divalent polyester group, a divalent polydiene group, a divalent polycarbonate group, and a divalent polyorganosiloxane group. Thus, the unit of formula (B) can be the urethane-containing segment described above coupled to the polymer segment described above. 6 is a divalent non-polymeric moiety, e.g., C2-C 12 a divalent hydrocarbyl group (e.g., —(CH2) m - (wherein m is an integer from 2 to 12).

[0094] The oligomer according to the invention may comprise one or more units of formula (A3).

[0095] [ka]

[0096] In the formula, R 1 is a divalent hydrocarbon group, and R 2 , R 4 , and R 10 are the same or different, -CH2-OC(=O)-CR 5 =CH2, where R 5 is H or CH3, and R3 is a trivalent organic, and the wavy line represents the point of attachment to another segment of the oligomer, particularly the urethane-containing segment. Thus, the unit of formula (A3) can be the urethane-containing segment described above coupled to the multi(meth)acrylate-functionalized segment described above.

[0097] In addition to one or more units of formula (A3), the oligomer may optionally additionally comprise one or more units of formula (B) as described above.

[0098] The oligomer may comprise a mixture of one or more units of formula (A2) and one or more units of formula (A3) as described above, and optionally may additionally comprise one or more units of formula (B) as described above.

[0099] A further aspect of the present invention provides a multi(meth)acrylate-functionalized oligomer having a polyurethane backbone, a plurality of (meth)acrylate functional groups pendant to the polyurethane backbone, and one or more terminal (meth)acrylate functional groups, wherein the oligomer comprises a) at least one diisocyanate, b) at least one diol compound comprising at least two (meth)acrylate functional groups or at least one triol compound comprising at least three (meth)acrylate functional groups, or a mixture thereof, and c) one isocyanate. The polymerizable composition is a reaction product of reactants including at least one end-capping compound comprising a reactive hydroxyl group and at least one (meth)acrylate functional group, and optionally, d) at least one chain extending diol (which does not have more than one (meth)acrylate functional group and may be non-polymeric or polymeric, e.g., a polymeric diol selected from the group consisting of polyether polyols, polyester polyols, polydiene polyols, polycarbonate polyols, and polyorganosiloxane polyols).

[0100] To prepare the (meth)acrylate-functionalized oligomers according to the present invention, a diisocyanate or a mixture of different diisocyanates can be utilized. As used herein, the term "diisocyanate" refers to an organic compound having two isocyanate (-NCO) functional groups per molecule. In some embodiments, the diisocyanate is an aliphatic diisocyanate (including cycloaliphatic diisocyanates) or an aromatic diisocyanate.

[0101] According to some embodiments of the present invention, the diisocyanate may be represented by the following formula (I'):

[0102] [ka]

[0103] In the formula, R 1 is a divalent organic group, e.g., a divalent hydrocarbon group. The divalent hydrocarbon group can be aliphatic (e.g., a linear, branched, or cyclic aliphatic group), aromatic, or araliphatic. The divalent organic group can also have, in addition to carbon and hydrogen atoms, one or more heteroatoms, e.g., N, O, or halogen.

[0104] Specific examples of suitable diisocyanates include, but are not limited to, isophorone diisocyanate (IPDI), toluene diisocyanate (TDI), dicyclohexylmethane 4,4'-diisocyanate (also known as methylene dicyclohexyl diisocyanate or hydrogenated MDI (HMDI)), hexamethylene diisocyanate (1,6-hexane diisocyanate), 4,4'-methylenebis(phenyl isocyanate), xylene diisocyanate, bitolidine diisocyanate, 1,5-naphthylene diisocyanate, naphthalene diisocyanate, and dianisidine diisocyanate, and polymethylene polyphenyl isocyanate. Preferred diisocyanates Examples include toluene diisocyanates (e.g., 2,4-toluene diisocyanate and 2,6-toluene diisocyanate), isophorone diisocyanate (IPDI), trimethylhexamethylene diisocyanate (e.g., 2,2,4-trimethylhexamethylene diisocyanate and 2,4,4-trimethylhexamethylene diisocyanate), xylylene diisocyanate (1,3-diisocyanatomethylbenzene), hydrogenated xylylene diisocyanate (sometimes referred to as 1,3-diisocyanatomethylcyclohexane), methylene bis(4-isocyanatocyclohexane) (sometimes referred to as hydrogenated MDI or methylene-bis-cyclohexane diisocyanate), and combinations thereof.

[0105] The polyol compounds used to prepare the multi(meth)acrylate-functionalized oligomers of the present invention have at least two (meth)acrylate functional groups in addition to at least two hydroxyl groups reactive with isocyanates. In some embodiments, the polyol compounds are diol compounds, i.e., compounds having only two hydroxyl groups reactive with isocyanates in addition to at least two (meth)acrylate functional groups. According to some aspects of the present invention, the polyol compounds are diol compounds corresponding to the following formula (II'a):

[0106] [ka]

[0107] In the formula, R 2 and R 4 are the same or different, -CH2-OC(=O)-CR 5 =CH2(wherein, R 5 is H or CH3), and R 3 is a divalent organic group. For example, R 3 -R 3’ -or-CH2-OR 3’ -O-CH2-(wherein, R 3’ R may be a divalent hydrocarbon group. Suitable divalent hydrocarbon groups include aliphatic divalent hydrocarbon groups (which can be linear, branched, or cyclic in structure), aromatic divalent hydrocarbon groups, and araliphatic divalent hydrocarbon groups. 3 may also contain, in addition to carbon and hydrogen atoms, one or more heteroatoms (e.g., N, O, S, halogens). Representative divalent hydrocarbon groups include, but are not limited to, one of the following groups:

[0108] [ka]

[0109] wherein m is an integer of at least 2 (e.g., 2 to 10); m' and m'' are independently an integer of 0 to 20; each Alk is independently a C2-C4 alkylene, typically ethylene or 1,2-propylene or 1,4-butylene; Each Ar is the same or different and is a substituted or unsubstituted aromatic group (e.g., a substituted or unsubstituted phenylene group), and R 8 and R 9 are the same or different and are selected from the group consisting of H, aryl, and alkyl.

[0110] According to some embodiments of the present invention, the polyol compound is 1,4-bis(3-acryloyloxy-2-hydroxypropoxy)butane (wherein in formula (II'a), R 2 and R 4 are -CH2-OC(=O)-CH=CH2, respectively, and R 3 is or contains -CH2-O-(CH2)4-O-CH2-). This compound can be obtained by reacting 1,4-butanediol diglycidyl ether and acrylic acid.

[0111] According to some embodiments of the present invention, the polyol compound is a triol compound corresponding to formula (II'b):

[0112] [ka]

[0113] In the formula, R 2 , R 3 , R 4 , and R 10 is as described above for formula (IIb).

[0114] According to some embodiments of the present invention, the polyol compound is a triacrylate of trimethylolpropane triglycidyl ether (wherein R 2 , R 4 , and R 10 are -CH2-OC(=O)-CH=CH2, respectively, and R 3 but,

[0115] [ka]

[0116] is) is or contains This compound can be obtained by reacting trimethylolpropane triglycidyl ether and acrylic acid.

[0117] The polyol compound can be, for example, a reaction product of reactants consisting of an acid-functionalized (meth)acrylate and a polyepoxide (e.g., a diepoxide or triepoxide). The acid-functionalized (meth)acrylate can have a structure corresponding to formula (V):

[0118] [ka]

[0119] In the formula, R is H or CH3, and n is an integer of 0 to 5. Compounds according to formula (V) include acrylic acid (R=H, n=0), methacrylic acid (R=CH3, n=0), and oligomers thereof (where n=1, 2, 3, 4, or 5), and mixtures thereof.

[0120] Suitable acid-functionalized (meth)acrylates also include so-called "half esters" which can be obtained by reacting anhydrides or dibasic acids with hydroxy-functionalized acrylates or methacrylates.

[0121] Suitable anhydrides and dibasic acids for such purposes include aliphatic, aromatic, and araliphatic anhydrides (having an anhydride group), and dibasic acids (containing two carboxylic acid groups). Exemplary anhydrides and dibasic acids include, but are not limited to, phthalic anhydride, isophthalic acid, terephthalic acid, tetrabromophthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, itaconic anhydride, itaconic acid, phthalic acid, 5-norbornene-endo-2,3-dicarboxylic anhydride, naphthyl anhydride, maleic anhydride, succinic anhydride, chlorendic anhydride, maleic acid, succinic acid, fumaric acid, oxalic acid, malonic acid, glutaric acid, adipic acid, and dimer fatty acid.

[0122] Hydroxy-functionalized (meth)acrylates that can be reacted with an acid anhydride or diacid to give acid-functionalized (meth)acrylates can have a structure corresponding to formula (IV'):

[0123] [ka]

[0124] In the formula, R 7 is an n+1 valent organic group, and R 8 is H or CH3, and n is an integer of 1 to 3.

[0125] Hydroxyalkyl (meth)acrylates, such as hydroxyethyl (meth)acrylate and hydroxypropyl (meth)acrylate, are used as the hydroxy-functional (meth)acrylate to react with the diepoxide in some embodiments of the present invention. Other suitable examples of hydroxy-functional (meth)acrylates include, but are not limited to, trimethylolpropane di(meth)acrylate, pentaerythritol tri(meth)acrylate, triethylolpropane di(meth)acrylate, hydroxybutyl (meth)acrylate, glycerol di(meth)acrylate, neopentyl glycol mono(meth)acrylate, hexanediol mono(meth)acrylate, octanediol mono(meth)acrylate, decanediol mono(meth)acrylate, tris(2-hydroxyethyl)propane di(meth)acrylate, methyltrimethylol ... di(meth)acrylate of alkoxylated (e.g., ethoxylated and / or propoxylated) trimethylolpropane, di(meth)acrylate of alkoxylated triethylolpropane, di(meth)acrylate of alkoxylated glycerol, mono(meth)acrylate of alkoxylated hexanediol, mono(meth)acrylate of alkoxylated neopentyl glycol, and compounds having the following structure:

[0126] [ka]

[0127] (wherein R is H or CH3, and x is an integer of 1 to 10) caprolactone (meth)acrylates (sometimes referred to as "caprolactone-modified (meth)acrylates"), mono(meth)acrylates of bisphenols and alkoxylated bisphenols, mono(meth)acrylates of bis(hydroxymethyl)cyclohexane and alkoxylated bis(hydroxymethyl)cyclohexane, mono(meth)acrylates of tricyclodecane dimethanol and alkoxylated tricyclodecane dimethanol, and combinations thereof.

[0128] Suitable diepoxides or triepoxides that can be reacted with the acid-functionalized (meth)acrylates include, but are not limited to, diepoxides selected from the group consisting of diene diepoxides and diglycidyl ethers, and triepoxides selected from triglycidyl ethers. A "diene diepoxide" is a compound corresponding to a diene in which both ene moieties (i.e., both sites of ethylenic unsaturation) have been epoxidized. A "diglycidyl ether" is a compound containing two glycidyl ether functional groups (i.e., the structure:

[0129] [ka]

[0130] Diepoxides can be aliphatic, aromatic, or araliphatic. "Triglycidyl ethers" are compounds having three glycidyl ether functional groups (i.e., a group having the structure:

[0131] [ka]

[0132] The triepoxides may be aliphatic, aromatic or araliphatic.

[0133] Specific examples of suitable diepoxides include diglycidyl ethers of bisphenol compounds (e.g., diglycidyl ethers of bisphenol A, bisphenol AP, bisphenol AF, bisphenol B, bisphenol BP, bisphenol C, bisphenol E, bisphenol F, bisphenol G, bisphenol M, bisphenol S, bisphenol P, bisphenol PH, bisphenol TMC, and bisphenol Z), diglycidyl ethers of hydrogenated bisphenol compounds, diglycidyl ethers of aliphatic glycols (e.g., diglycidyl ethers of ethylene glycol, propylene glycol, or neopentyl glycol), and the like. diglycidyl ether), 1,4-butanediol diglycidyl ether, 1,3-butadiene diepoxide, diepoxide of vinylcyclohexene, diepoxide of octadiene, dicyclopentadiene dioxide, diglycidyl 1,2-cyclohexanedicarboxylate, diepoxycyclooctane, 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, diglycidyl ether of dihydroxynaphthalene, diglycidyl ether, 1,4-dihydroxybenzene diglycidyl ether, catechol diglycidyl ether and resorcinol diglycidyl ether, and combinations thereof. Specific examples of suitable triepoxides include trimethylolpropane triglycidyl ether, trimethylolethane triglycidyl ether, castor oil glycidyl ether, glycerol triglycidyl ether, propoxylated glycol triglycidyl ether, polyglycerol-3-polyglycidyl ether, phloroglucinol triglycidyl ether, tris(4-hydroxyphenyl)methane triglycidyl ether, tris(4-hydroxyphenyl)ethane triglycidyl ether, and combinations thereof.

[0134] The end-capping compound can be selected from the group consisting of (meth)acrylates of polyols, in which all but one hydroxyl group is (meth)acrylated. The polyol can be, for example, a diol, triol, or tetraol. Suitable end-capping compounds can generally correspond to the hydroxyl-functional (meth)acrylates described above and can have a structure corresponding to the following formula (IV'):

[0135] [ka]

[0136] In the formula, R 7 is an n+1 valent organic group, and R 8 is H or CH3, and n is an integer of 1 to 3.

[0137] Hydroxyalkyl (meth)acrylates, such as hydroxyethyl (meth)acrylate and hydroxypropyl (meth)acrylate, are used as end-capping compounds in some embodiments of the present invention. Examples of other suitable end-capping compounds include, but are not limited to, trimethylolpropane di(meth)acrylate, pentaerythritol tri(meth)acrylate, triethylolpropane di(meth)acrylate, hydroxybutyl (meth)acrylate, glycerol di(meth)acrylate, and neopentyl glycol. mono(meth)acrylate, hexanediol mono(meth)acrylate, octanediol mono(meth)acrylate, decanediol mono(meth)acrylate, tris(2-hydroxyethyl)isocyanurate di(meth)acrylate, diethylene glycol mono(meth)acrylate, dipropylene glycol mono(meth)acrylate, di(meth)acrylate of alkoxylated (e.g., ethoxylated and / or propoxylated) trimethylolpropane, di(meth)acrylate of alkoxylated triethylolpropane, di(meth)acrylate of alkoxylated glycerol, mono(meth)acrylate of alkoxylated hexanediol, mono(meth)acrylate of alkoxylated neopentyl glycol, the following structure:

[0138] [ka]

[0139] (wherein R is H or CH3, and x is an integer of 1 to 10) caprolactone (meth)acrylate, mono(meth)acrylates of bisphenol and alkoxylated bisphenol, mono(meth)acrylates of bis(hydroxymethyl)cyclohexane and alkoxylated bis(hydroxymethyl)cyclohexane, mono(meth)acrylates of tricyclodecane dimethanol and alkoxylated tricyclodecane dimethanol, and combinations thereof.

[0140] As previously mentioned, multi(meth)acrylate-functionalized oligomers can be prepared using one or more polymeric diols and / or one or more non-polymeric diols as optional reactants. Such diols may be considered chain-extending diols because they can function to increase the average spacing between multi(meth)acrylate-functionalized segments along the polyurethane backbone of the oligomer and / or to increase the number-average molecular weight of the oligomer. As used herein, the term "polymeric diol" refers to a polymer having two isocyanate-reactive hydroxyl groups per molecule. As used herein, the term "non-polymeric diol" refers to a non-polymeric compound having two isocyanate-reactive hydroxyl groups per molecule. In the context of the present invention, the term "polymer" refers to a compound containing five or more repeat units per molecule, and the term "non-polymeric compound" refers to a compound containing up to four repeat units per molecule (and thus both monomeric and oligomeric compounds having two to four repeat units per molecule). For example, ethylene glycol, diethylene glycol, triethylene glycol, and tetraethylene glycol are all examples of non-polymeric diols, while polyethylene glycol containing five or more oxyalkylene repeat units is an example of a polymeric diol.

[0141] Preferably, the hydroxyl groups are primary and / or secondary hydroxyl groups. When the chain-extending diol is a polymer polyol, the hydroxyl groups may be located at the termini (ends) of the polymer, according to some embodiments. However, it is also possible for the hydroxyl groups to be present along the polymer backbone or on side chains or groups pendant to the polymer backbone. The polymer portion of the polymer diol may be composed of multiple repeating units, such as oxyalkylene units, ester units, carbonate units, acrylic units, alkylene units, etc., or combinations thereof.

[0142] According to some embodiments of the present invention, the polymeric diol may be represented by the following formula (III'):

[0143] [ka]

[0144] In the formula, R 6 is a polyether (eg, polyoxyalkylene), polycarbonate, polydiene, polyorganosiloxane, or polyester chain.

[0145] Particularly preferred polymer diols include polyether diols and polyester diols. Suitable polyether diols include, for example, polytetramethylene glycol (a hydroxyl-functionalized polymer of tetrahydrofuran) and polyethylene glycol (a hydroxyl-functionalized polymer of ethylene oxide). Suitable polyester diols include, for example, poly(caprolactone), poly(lactide), poly(alkylene glycol adipate), and poly(alkylene glycol succinate).

[0146] Other types of polymer polyols that may be useful in the present invention include polycarbonate polyols, polyorganosiloxane diols (e.g., polydimethylsiloxane diols), and polydiene diols (e.g., polybutadiene diols, including fully or partially hydrogenated polydiene polyols).

[0147] The molecular weight of the polymeric diol can be varied as needed or desired to achieve specific properties in the multi(meth)acrylate-functionalized oligomer prepared therefrom and / or in the curable composition containing the multi(meth)acrylate-functionalized oligomer and / or in the cured composition obtained by curing the curable composition. For example, the number average molecular weight of the polymeric diol can be at least 300, at least 350, or at least 400 daltons. In other embodiments, the polymeric diol can have a number average molecular weight of 5000 daltons or less, 4500 daltons or less, or 4000 daltons or less. For example, the polymeric diol can have a number average molecular weight of 250 to 5000 daltons, 300 to 4500 daltons, or 350 to 4000 daltons.

[0148] According to some embodiments of the present invention, the chain extending diol can be represented by formula (IIIa'):

[0149] [ka]

[0150] In the formula, R 6a is a divalent non-polymeric aliphatic group that optionally additionally contains one or more heteroatoms (e.g., O, N, S and / or halogens).

[0151] In some embodiments of the present invention, the chain-extended diol is or includes a hydrogenated dimer fatty acid (sometimes referred to as a "dimer diol") non-polymeric diol, e.g., a diol obtained by dimerizing one or more unsaturated fatty acids, such as oleic acid or linoleic acid, followed by hydrogenation to convert the carboxylic acid groups to hydroxyl groups. Pripol® 2033 (a product sold by Croda) is one example of a suitable commercially available hydrogenated dimer fatty acid.

[0152] Other types of suitable non-polymeric diols include, but are not limited to, C2-C12 aliphatic diols and their oligomers (containing up to four oxyalkylene repeat units). The aliphatic diols may be linear, branched, or cyclic in structure, and their hydroxyl groups may both be primary, both secondary, or one of each type (one primary and one secondary hydroxyl group).

[0153] Examples of suitable C2-C12 aliphatic diols include, but are not limited to, ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,2-dimethyl-1,3-propanediol, 2,2,4-trimethyl-1,5-pentanediol, and 2-methyl-2-ethyl-1,3-propanediol, and oligomers thereof having up to four oxyalkylene repeat units.

[0154] Exemplary Methods for Making Multi(meth)acrylate-Functionalized Oligomers Various exemplary methods for preparing multi(meth)acrylate-functionalized oligomers according to the present invention can be described as follows.

[0155] Method 1: Multi(meth)acrylate-functionalized oligomers according to the present invention may be synthesized by a method comprising combining and reacting at least one diisocyanate, at least one diol compound having at least two (meth)acrylate functional groups or at least one triol compound having at least three (meth)acrylate functional groups, or a mixture thereof, at least one end-capping compound consisting of one isocyanate-reactive hydroxyl group and at least one (meth)acrylate functional group, and optionally at least one polymeric diol to obtain a multi(meth)acrylate-functionalized oligomer.

[0156] Method 2: Multi(meth)acrylate-functionalized oligomers according to the present invention can be synthesized by a method comprising: a) combining and reacting at least one diisocyanate with at least one diol compound having at least two (meth)acrylate functional groups or at least one triol compound having at least three (meth)acrylate functional groups, or a mixture thereof, and optionally at least one polymeric diol, to form an isocyanate-terminated intermediate oligomer; and b) combining and reacting the isocyanate-terminated intermediate oligomer with at least one end-capping compound having one isocyanate-reactive hydroxyl group and at least one (meth)acrylate functional group to form a multi(meth)acrylate-functionalized oligomer. The NCO:OH stoichiometry of the reactants in step a) can be adjusted, and / or the manner and / or order in which the reactants are combined and reacted can be varied to favor the formation of the isocyanate-terminated intermediate oligomer in step a).

[0157] Method 3: Multi(meth)acrylate-functionalized oligomers according to the present invention may be synthesized by a method comprising the steps of: a) combining and reacting at least one diisocyanate with at least one diol compound having at least two (meth)acrylate functional groups or at least one triol compound having at least three (meth)acrylate functional groups, or a mixture thereof, and optionally with at least one polymeric diol, to obtain a hydroxyl-terminated intermediate oligomer; and b) combining and reacting the hydroxyl-terminated intermediate oligomer with at least one isocyanate-functionalized (meth)acrylate (or a combination of a diisocyanate and an end-capping compound such as a hydroxyl-functionalized (meth)acrylate, e.g., 2-hydroxyethyl acrylate), to obtain a multi(meth)acrylate-functionalized oligomer. The NCO:OH stoichiometry of the reactants in step a) can be adjusted and / or the manner and / or order in which the reactants are combined and reacted can be varied to favor the production of the hydroxyl-terminated intermediate oligomer in step a).Isocyanate-functionalized (meth)acrylates can be provided by reacting a diisocyanate with an end-capping compound having one isocyanate-reactive hydroxyl group and at least one (meth)acrylate functionality as described herein.

[0158] Method 4: Multi(meth)acrylate-functionalized oligomers according to the present invention may be synthesized by a method comprising the steps of: a) combining and reacting at least one diisocyanate with at least one diol compound having at least two (meth)acrylate functional groups or at least one triol compound having at least three (meth)acrylate functional groups, or a mixture thereof, to obtain an isocyanate-terminated intermediate oligomer; b) combining and reacting the isocyanate-terminated intermediate oligomer with a chain-extended polyol having at least two hydroxyl groups and zero to one (meth)acrylate functional group to obtain a hydroxyl-terminated intermediate oligomer; and c) combining and reacting the hydroxyl-terminated intermediate oligomer with at least one isocyanate-functionalized (meth)acrylate (or a combination of a diisocyanate and an end-capping compound such as a hydroxyl-functionalized (meth)acrylate, e.g., 2-hydroxyethyl acrylate), to obtain the multi(meth)acrylate-functionalized oligomer. The NCO:OH stoichiometry of the reactants in step a) can be adjusted and / or the manner and / or order in which the reactants are combined and reacted can be varied to favor the production of an isocyanate-terminated intermediate oligomer in step a). The NCO:OH stoichiometry of the reactants in step b) can be adjusted and / or the manner and / or order in which the reactants are combined and reacted can be varied to favor the production of a hydroxyl-terminated intermediate oligomer in step b). Isocyanate-functionalized (meth)acrylates can be provided by reacting a diisocyanate with an end-capping compound having one isocyanate-reactive hydroxyl group and at least one (meth)acrylate functionality as described herein.

[0159] The amounts of the various components can vary over a wide range, depending on the application. The amount of at least one diol compound having at least two (meth)acrylate functional groups or at least one triol compound having at least three (meth)acrylate functional groups, individually or collectively, can preferably vary from 0.1 wt% to 35 wt% (by weight), more preferably from 0.2 wt% to 25 wt%, and most preferably from 1 wt% to 10 wt% (based on all reactants). The overall NCO:OH stoichiometry can be adjusted so that the free hydroxyl number in the final product is between 0 and 20 mg KOH / g sample. The free hydroxyl number is determined by hydroxyl titration (ASTM E1899-08).

[0160] To prevent undesired side reactions, an antioxidant (stabilizer), such as butylated hydroxytoluene, may be present during the reaction of the components used to prepare the oligomer, and / or the reaction mixture may be sparged with air while such reaction is occurring. Conditions effective for achieving the reaction between isocyanate compounds and isocyanate-reactive compounds of the type described herein useful in preparing oligomers according to the present invention are well known in the art and can be readily selected and adapted as needed to achieve the desired results for purposes of the present invention. For example, the reaction mixture may be heated and / or a urethane catalyst (described below) may be introduced to accelerate the reaction. Furthermore, the stoichiometry between the different components used to prepare the oligomer may be adjusted according to conventional practice, particularly to achieve the desired degree of polyurethane chain extension and / or end-group functionalization.

[0161] <Urethane catalyst> According to some embodiments of the present invention, one or more urethane catalysts are used in the preparation of multi(meth)acrylate-functionalized oligomers from the reactants described hereinabove. As used herein, "urethane catalyst" refers to a substance capable of catalyzing the reaction of hydroxyl groups with isocyanate groups to form urethane linkages. Thus, a urethane catalyst can accelerate the rate at which such a reaction occurs at a given temperature and / or can achieve a target degree of completion of such a reaction at a lower temperature than the temperature at which the target degree of completion would be achieved in the absence of the urethane catalyst.

[0162] Any tin-based urethane catalyst known in the art may be utilized. However, according to some preferred embodiments, a non-tin urethane catalyst or a combination of non-tin urethane catalysts is used. In some embodiments, the intermediate reaction mixture and the resulting product (including the multi(meth)acrylate-functionalized oligomer) are free or substantially free of any tin urethane catalyst. For example, the reaction mixture at each stage, as well as the final reaction product and curable composition, may contain less than 500 ppb tin, less than 400 ppb tin, less than 300 ppb tin, less than 200 ppb tin, or less than 100 ppb tin.

[0163] Suitable non-tin urethane catalysts include, for example, one or more non-tin urethane catalysts selected from the group consisting of bismuth carboxylate complexes (such as bismuth octoate); zirconium acetylacetonate complexes; hafnium acetylacetonate complexes; titanium acetylacetonate complexes; zirconium β-diketiminate complexes; hafnium β-diketiminate complexes; titanium β-diketiminate complexes; zirconium amidinate complexes; hafnium amidinate complexes; titanium amidinate complexes; zinc carboxylate complexes; tertiary amines; imidazoles; N-heterocyclic carbenes; tetraalkylammonium (pseudo)halides; phosphines; and combinations thereof.

[0164] Typically, the urethane catalyst is utilized in an amount of 0.0001 to 0.1 weight percent based on the total weight of the final (meth)acrylate-functionalized oligomer.

[0165] <Curable Composition Containing Multi(meth)acrylate-Functionalized Oligomer> While the multi(meth)acrylate-functionalized oligomers of the present invention can be used by themselves as curable compositions (i.e., compositions that can be cured to provide a polymerized, hardened material), in other aspects of the present invention, one or more multi(meth)acrylate-functionalized oligomers according to the present invention can be formulated with one or more additives (i.e., materials other than the multi(meth)acrylate-functionalized oligomers of the present invention) to provide curable compositions. Such additives can include, for example, reactive diluents, oligomers (particularly (meth)acrylate-functionalized oligomers) other than the multi(meth)acrylate-functionalized oligomers of the present invention, stabilizers, initiators (including photoinitiators), fillers, pigments, etc., and combinations thereof. Any of the additives known or used in the curable (meth)acrylate resin art can also be used with the multi(meth)acrylate-functionalized oligomers of the present invention to formulate curable compositions that are useful for a wide variety of end uses. Some of such additives are discussed in more detail below.

[0166] <Additional reactive components> The curable composition can be formulated to include one or more additional components that can react with the multi(meth)acrylate-functionalized oligomer according to the present invention. That is, such additional components are covalently bonded to the polymer matrix formed upon curing of the curable composition. Such additional reactive components typically contain one or more ethylenically unsaturated functional groups per molecule, particularly one or more (meth)acrylate functional groups per molecule. Other types of suitable ethylenically unsaturated functional groups include, for example, vinyl functional groups and allyl functional groups. The additional reactive components can be monomers or oligomers, as described in more detail below.

[0167] The relative amounts of the multi(meth)acrylate-functionalized oligomer according to the present invention and the additional reactive component (such as other (meth)acrylate-functionalized compounds) in the curable composition are not believed to be critical and can vary widely depending on the particular components selected for use and the properties desired in the curable composition and the resulting cured composition. For example, the curable composition may be comprised of 0.5 to 99.5 wt. % of the multi(meth)acrylate-functionalized oligomer according to the present invention and 0.5 to 99.5 wt. % of the additional reactive component, based on the total weight of the multi(meth)acrylate-functionalized oligomer according to the present invention and the additional reactive component.

[0168] Suitable (meth)acrylate-functionalized compounds include both (meth)acrylate-functionalized monomers and (meth)acrylate-functionalized oligomers.

[0169] According to some embodiments of the present invention, the curable composition comprises, in addition to at least one multi(meth)acrylate-functionalized oligomer according to the present invention, at least one (meth)acrylate-functionalized monomer containing two or more (meth)acrylate functional groups per molecule. Examples of useful (meth)acrylate-functionalized monomers containing two or more (meth)acrylate functional groups per molecule include acrylic and methacrylic acid esters of polyhydric alcohols (organic compounds containing two or more, e.g., 2 to 6, hydroxyl groups per molecule). Specific examples of suitable polyhydric alcohols include C -C ... 2~20 Alkylene glycol (C 2~10Glycols having alkylene groups may be preferred, such as 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, for example, in which 1 to 20 moles of alkylene oxide, such as ethylene oxide and / or propylene oxide, are reacted with 1 mole of glycol, diethylene glycol, glycerin, alkoxylated glycerin, triethylene glycol, dipropylene glycol, tripropylene glycol, trimethylolpropane, alkoxylated trimethylolpropane, alkoxylated tetramethylolpropane, ... Examples of suitable alkoxylated polyols include trimethylolpropane, ditrimethylolpropane, alkoxylated ditrimethylolpropane, pentaerythritol, alkoxylated pentaerythritol, dipentaerythritol, alkoxylated dipentaerythritol, cyclohexanediol, alkoxylated cyclohexanediol, cyclohexanedimethanol, alkoxylated cyclohexanedimethanol, norbornene dimethanol, alkoxylated norbornene dimethanol, norbornane dimethanol, alkoxylated norbornane dimethanol, aromatic ring-containing polyols, cyclohexane-1,4-dimethanol ethylene oxide adducts, bisphenol 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.As used herein, the term "alkoxylation" refers to a compound in which one or more epoxides, such as ethylene oxide and / or propylene oxide, are reacted with active hydrogen-containing groups (e.g., hydroxyl groups) of a base compound, such as a polyhydric alcohol, to form one or more oxyalkylene groups. For example, 1 to 25 moles of epoxide may be reacted per mole of base compound. According to some embodiments of the present invention, the (meth)acrylate-functionalized monomers used may have a relatively low molecular weight (e.g., 100 to 1000 daltons).

[0170] Any (meth)acrylate-functionalized oligomer known in the art may be used in the curable compositions of the present invention, provided that the curable compositions contain at least one multi(meth)acrylate-functionalized oligomer according to the present invention. According to some embodiments, such oligomers contain two or more (meth)acrylate functional groups per molecule. The number average molecular weight of such oligomers can vary widely, for example, from about 500 to about 50,000.

[0171] Suitable (meth)acrylate-functionalized oligomers include, for example, polyester (meth)acrylate oligomers, epoxy (meth)acrylate oligomers, polyether (meth)acrylate oligomers, polyurethane (meth)acrylate oligomers, acrylic (meth)acrylate oligomers, polydiene (meth)acrylate oligomers, polycarbonate (meth)acrylate oligomers, and combinations thereof. Such oligomers can be selected and used in combination with one or more (meth)acrylate-functionalized monomers to enhance the flexibility, strength, and / or modulus, among other attributes, of cured resin foams prepared using the multi-component systems of the present invention.

[0172] Exemplary polyester (meth)acrylate oligomers include the reaction product of acrylic acid or methacrylic acid, or a mixture thereof, with a hydroxyl-terminated polyester polyol. The reaction process can be carried out so that all or essentially all of the hydroxyl groups of the polyester polyol are (meth)acrylated, particularly when the polyester polyol is difunctional. The polyester polyol can be made by the polycondensation reaction of a polyhydroxyl-functional component (particularly a diol) with a polycarboxylic acid-functional compound (particularly a dicarboxylic acid and anhydride). The polyhydroxyl-functional component and the polycarboxylic acid-functional component can each have a linear, branched, alicyclic, or aromatic structure and can be used individually or in mixtures.

[0173] Examples of suitable epoxy (meth)acrylate oligomers include the reaction products of acrylic acid or methacrylic acid, or mixtures thereof, with glycidyl ethers or esters.

[0174] Suitable polyether (meth)acrylate oligomers include, but are not limited to, the condensation reaction products of acrylic acid or methacrylic acid, or a mixture thereof, with a polyether polyol (such as polyethylene glycol, polypropylene glycol, or polytetramethylene glycol), which is a polyetherol. Suitable polyetherols can be linear or branched materials containing ether linkages and terminal hydroxyl groups. Polyetherols can be prepared by the ring-opening polymerization of cyclic ethers such as tetrahydrofuran or alkylene oxides using starter molecules. Suitable starter molecules include water, polyhydroxyl-functional materials, polyester polyols, and amines.

[0175] Polyurethane (meth)acrylate oligomers (sometimes referred to as "urethane (meth)acrylate oligomers") that can be used in the multi-component systems of the present invention include urethanes based on aliphatic and / or aromatic polyester polyols and polyether polyols and aliphatic 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.

[0176] In various embodiments, polyurethane (meth)acrylate oligomers can be prepared by reacting an aliphatic and / or aromatic diisocyanate with an OH-terminated polyester polyol (including aromatic, aliphatic, and mixed aliphatic / aromatic polyester polyols), polyether polyols, polycarbonate polyols, polycaprolactone polyols, polyorganosiloxane polyols (e.g., polydimethylsiloxane polyols), or polydiene polyols (e.g., polybutadiene polyols), or combinations thereof, to form an isocyanate-functionalized oligomer, which can then be reacted with a hydroxyl-functionalized (meth)acrylate, such as hydroxyethyl acrylate or hydroxyethyl methacrylate, to form terminal (meth)acrylate groups. For example, the polyurethane (meth)acrylate oligomer can contain two, three, four, or more (meth)acrylate functional groups per molecule.

[0177] Suitable acrylic (meth)acrylate oligomers (sometimes referred to in the art as "acrylic oligomers") include oligomers that can be described as materials having an oligomeric acrylic backbone functionalized with one or more (meth)acrylate groups (which can be at the end of the oligomer or pendant to the acrylic backbone). The acrylic backbone can be a homopolymer, random copolymer, or block copolymer composed of repeating units of acrylic monomers. The acrylic monomer can be any monomeric (meth)acrylate, such as C1-C6 alkyl (meth)acrylates and functionalized (meth)acrylates, such as (meth)acrylates with hydroxyl, carboxylic acid, and / or epoxy groups. Acrylic (meth)acrylate oligomers may be prepared using any procedure known in the art, such as by oligomerizing monomers at least a portion of which are functionalized with hydroxyl, carboxylic acid, and / or epoxy groups (e.g., hydroxyalkyl (meth)acrylate, (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.

[0178] Exemplary (meth)acrylate functionalized monomers and oligomers 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 (600) dimethacrylate (60 0 refers to the approximate number average molecular weight of the polyethylene glycol portion); 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; cyclohexanedimethanol dimethacrylate; cyclohexanedimethanol diacrylate; ethoxylated 10 Bisphenol A dimethacrylate (the number following "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 2 neopentyl glycol diacrylate;Alkoxylated diacrylates of 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 acrylates;Trifunctional methacrylates;Trifunctional acrylates;Propoxylated 3 glyceryl triacrylate;Propoxylated 5.5 Glyceryl triacrylate; ethoxylated 15Examples of suitable oligomers include trimethylolpropane triacrylate, trifunctional phosphate esters, trifunctional acrylic esters, pentaerythritol tetraacrylate, di-trimethylolpropane tetraacrylate, ethoxylated 4-pentaerythritol tetraacrylate, pentaerythrilol polyoxyethylene tetraacrylate, dipentaerythritol pentaacrylate, pentaacrylic esters, epoxy acrylate oligomers, epoxy methacrylate oligomers, urethane acrylate oligomers, urethane methacrylate oligomers, polyester acrylate oligomers, polyester methacrylate oligomers, stearyl methacrylate oligomers, acrylic acrylate oligomers, perfluorinated acrylate oligomers, perfluorinated methacrylate oligomers, aminoacrylate oligomers, amine-modified polyether acrylate oligomers, and amino methacrylate oligomers.

[0179] The curable compositions of the present invention may optionally include one or more (meth)acrylate-functionalized compounds containing only one acrylate or methacrylate functional group per molecule (referred to herein as "mono(meth)acrylate-functionalized compounds"). Any such compounds known in the art may be used.

[0180] Examples of suitable mono(meth)acrylate-functionalized compounds include mono-(meth)acrylic acid esters of aliphatic alcohols (the aliphatic alcohols can be linear, branched, or alicyclic and can be mono-, di-, or polyalcohols, provided that only one hydroxyl group is esterified with (meth)acrylic acid); mono-(meth)acrylic acid esters of aromatic alcohols (such as phenol, including alkylated phenols); mono-(meth)acrylic acid esters of alkylaryl alcohols (such as benzyl alcohol); mono-(meth)acrylic acid esters of oligomeric and polymeric glycols, such as diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol, and polypropylene glycol. mono-(meth)acrylic acid esters of monoalkyl ethers of glycols, oligomeric glycols, polymeric glycols; mono-(meth)acrylic acid esters of alkoxylated (e.g., ethoxylated and / or propoxylated) fatty alcohols (the fatty alcohols can be linear, branched, or alicyclic and can be mono-alcohols, di-alcohols, or polyalcohols, provided that only one hydroxyl group of the alkoxylated fatty alcohol is esterified with (meth)acrylic acid); mono-(meth)acrylic acid esters of alkoxylated (e.g., ethoxylated and / or propoxylated) aromatic alcohols (such as alkoxylated phenols); caprolactone mono(meth)acrylate, and the like.

[0181] The following compounds are illustrative of mono(meth)acrylate-functionalized compounds 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. t)acrylate;Tridecyl (meth)acrylate;Tetradecyl (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;Iso Bornyl (meth)acrylate; 2-(2-ethoxyethoxy)ethyl (meth)acrylate; cyclohexyl (meth)acrylate; glycidyl (meth)acrylate; isodecyl (meth)acrylate; 2-phenoxyethyl (meth)acrylate; lauryl (meth)acrylate; isobornyl (meth)acrylate; 2-phenoxyethyl (meth)acrylate; alkoxylated phenol (meth)acrylate; alkoxylated nonylphenol (meth)acrylate; cyclic trimethylolpropane formal (meth)acrylate; trimethylcyclohexanol (meth)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; and combinations thereof.

[0182] <Stabilizer> Generally speaking, it is desirable to include one or more stabilizers in the curable compositions of the present invention to provide sufficient storage stability and shelf life. Advantageously, one or more such stabilizers are present at each stage of the process used to prepare the curable compositions to protect against undesired reaction of the components of the curable compositions (especially those components of the curable compositions having (meth)acrylate functionality). As used herein, the term "stabilizer" refers to a compound or substance that retards or prevents reaction or curing of the (meth)acrylate functionality present in the composition in the absence of actinic radiation. However, it is advantageous to select the amount and type of stabilizer so that the composition remains curable when exposed to actinic radiation (i.e., the stabilizer does not interfere with radiation curing of the composition). Typically, stabilizers effective for purposes of the present invention are classified as radical stabilizers (i.e., stabilizers that function by inhibiting radical reaction).

[0183] Any stabilizer known in the art for (meth)acrylate-functionalized compounds can be used in the present invention. Quinones are a particularly preferred type of stabilizer that can be used in connection with the present invention. As used herein, the term "quinone" includes both quinone and hydroquinone, as well as their ethers, such as monoalkyl, monoaryl, monoaralkyl, and bis(hydroxyalkyl) ethers of hydroquinone. Hydroquinone monomethyl ether is an example of a suitable stabilizer that can be used.

[0184] The concentration of stabilizer in the curable composition can vary depending on the particular stabilizer or combination of stabilizers selected for use, as well as the degree of stabilization desired and the susceptibility of the components in the curable composition to degradation in the absence of the stabilizer. Typically, however, curable compositions are formulated to contain 50 to 5,000 ppm of stabilizer. According to some embodiments of the present invention, the reaction mixture at each stage of the process used to make the curable composition contains at least some stabilizer, e.g., at least 50 ppm of stabilizer.

[0185] <Photoinitiator> In some embodiments of the present invention, the curable compositions described herein include at least one photoinitiator and are curable using radiant energy. A photoinitiator can be considered any type of substance that, upon exposure to radiation (e.g., actinic radiation), forms a chemical species that initiates a reaction and hardening that polymerizes organic materials present in the curable composition. Suitable photoinitiators include both free-radical and cationic photoinitiators, and combinations thereof.

[0186] A free radical polymerization initiator is a substance that forms free radicals when irradiated. The use of free radical photoinitiators is particularly preferred. Non-limiting examples of types of free radical photoinitiators suitable for use in the curable compositions of the present invention include benzoins, benzoin ethers, acetophenones, benzil, benzil ketals, anthraquinones, phosphine oxides, α-hydroxyketones, phenylglyoxylates, α-aminoketones, benzophenones, thioxanthones, xanthones, acridine derivatives, phenazene derivatives, quinoxaline derivatives, and triazine compounds.

[0187] The amount of photoinitiator can vary as may be appropriate depending on, among other factors, the photoinitiator selected, the amount and type of polymerizable species present in the curable composition, the radiation source and radiation conditions used, etc. Typically, however, the amount of photoinitiator can be from 0.05% to 5% by weight, preferably from 0.1% to 2% by weight, based on the total weight of the curable composition.

[0188] <Other additives> The curable compositions of the present invention may optionally contain one or more additives in place of or in addition to the above components, such as antioxidants / light stabilizers, light screeners / light absorbers, polymerization inhibitors, antifoam agents, flow or leveling agents, colorants, pigments, dispersants (wetting agents, surfactants), slip agents, fillers, chain transfer agents, thixotropic agents, matting agents, impact modifiers, waxes, or various other additives, including, but not limited to, any of the additives typically utilized in the coatings, sealants, adhesives, molding, 3D printing, or ink arts.

[0189] The curable compositions of the present invention can include one or more light-blocking agents (sometimes referred to in the art as absorbers), particularly when the curable compositions are intended for use as resins in three-dimensional printing processes involving photocuring of the curable compositions. Light-blocking agents can be any such substance known in the three-dimensional printing art, including, for example, non-reactive pigments and dyes. Light-blocking agents can be, for example, visible light blockers or UV light blockers. Examples of suitable light-blocking agents include, but are not limited to, titanium dioxide, carbon black, and organic UV absorbers such as hydroxybenzophenone, hydroxyphenylbenzotriazole, oxanilide, benzophenone, thioxanthone, hydroxyphenyltriazine, Sudan I, bromothymol blue, 2,2′-(2,5-thiophenediyl)bis(5-tert-butylbenzoxazole) (sold under the trade name “Benetex OB Plus”), and benzotriazole UV absorbers.

[0190] The amount of light-blocking agent can be varied as may be desired or suitable for a particular application. Generally speaking, when the curable composition contains a light-blocking agent, the light-blocking agent is present in a concentration of 0.001 to 10% by weight, based on the weight of the curable composition.

[0191] Advantageously, the curable compositions of the present invention can be formulated to be solvent-free, i.e., free of any non-reactive volatile materials (materials having a boiling point of 150° C. or less at atmospheric pressure). For example, the curable compositions of the present invention can contain little or no non-reactive solvent, for example, less than 10%, or less than 5%, or less than 1%, or even 0%, of non-reactive solvent based on the total weight of the curable composition.

[0192] <Use of multi(meth)acrylate-functionalized oligomer and curable composition containing multi(meth)acrylate-functionalized oligomer> As mentioned above, the curable compositions prepared according to the present invention can contain one or more photoinitiators and can be photocurable. In some other embodiments of the present invention, the curable compositions described herein do not contain any initiators and can be (at least partially) cured with electron beam energy. In other embodiments, the curable compositions described herein contain at least one free radical initiator that decomposes when heated or in the presence of an accelerator, making them chemically curable (i.e., without the need to expose the curable composition to radiation). The at least one free radical initiator that decomposes when heated or in the presence of an accelerator can include, for example, a peroxide or an azo compound. Suitable peroxides for this purpose can include any compound, particularly any organic compound, containing at least one peroxy (—OO—) group, such as dialkyl, diaryl, and aryl / alkyl peroxides, hydroperoxides, percarbonates, peresters, peracids, acyl peroxides, etc. The at least one accelerator can include, for example, at least one tertiary amine and / or one or more other reducing agents based on metal-containing salts (e.g., carboxylates of transition metals such as iron, cobalt, manganese, vanadium, and combinations thereof). The accelerator can be selected to accelerate decomposition of the free radical initiator to generate active free radical species at room temperature, such that curing of the curable composition is achieved without the need for heating or baking the curable composition. In other embodiments, no accelerator is present, and the curable composition is heated to a temperature effective to cause decomposition of the free radical initiator to generate free radical species that initiate curing of the polymerizable compounds present in the curable composition.

[0193] Advantageously, the curable compositions of the present invention can be formulated to be solvent-free, i.e., free of any non-reactive volatile materials (materials having a boiling point of 150°C or less at atmospheric pressure). For example, the curable compositions of the present invention can contain little or no non-reactive solvent, e.g., less than 10%, or less than 5%, or less than 1%, or even 0%, of non-reactive solvent based on the total weight of the curable composition. When reactive diluents are used in the curable compositions, they can be selected to reduce the viscosity of the curable composition sufficiently, even in the absence of solvent, so that the curable composition can be easily applied to a substrate surface at a suitable application temperature to form a relatively thin, uniform layer.

[0194] In preferred embodiments of the invention, the curable compositions are liquid at 25° C. In various embodiments of the invention, the curable compositions described herein are formulated to have a viscosity of less than 10,000 mPa·s (cP), or less than 5000 mPa·s (cP), or less than 4000 mPa·s (cP), or less than 3000 mPa·s (cP), or less than 2500 mPa·s (cP), or less than 2000 mPa·s (cP), or less than 1500 mPa·s (cP), or less than 1000 mPa·s (cP), or even less than 500 mPa·s (cP), as measured at 25° C. on a Brookfield Viscometer Model DV-II using spindle 27 (spindle speed typically varies between 20 rpm and 200 rpm depending on viscosity). In advantageous embodiments of the invention, the viscosity of the curable composition is 200 to 5000 mPa·s (cP), or 200 to 2000 mPa·s (cP), or 200 to 1500 mPa·s (cP), or 200 to 1000 mPa·s (cP) at 25° C. A relatively high viscosity can provide satisfactory performance in applications where the curable composition is heated to temperatures above 25° C., such as in three-dimensional printing operations using machines equipped with heated resin vats.

[0195] The curable compositions described herein can be compositions that can undergo curing by free radical polymerization, cationic polymerization, or other types of polymerization. In certain embodiments, the curable compositions are photocured (i.e., cured by exposure to actinic radiation such as light, especially visible or UV light). End uses of the curable compositions 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.

[0196] Cured compositions prepared from the curable compositions described herein may be used, for example, in three-dimensional articles (three-dimensional articles which can consist essentially of or consist of the cured composition), coated articles (articles in which a substrate is coated with one or more layers of the cured composition, including encapsulated articles in which the substrate is completely surrounded by the cured composition), laminated or laminated articles (articles in which a first component of the article is laminated or laminated to a second component by the cured composition), composite articles, or printed articles (articles in which a graphic or the like is printed onto a substrate, e.g., paper, plastic, or M-containing substrate, using the cured composition).

[0197] Curing of the curable composition according to the present invention can be carried out by any suitable method, such as free radical and / or cationic polymerization. One or more initiators, such as radical initiators (e.g., photoinitiators, peroxide initiators), can be present in the curable composition. Before curing, the curable composition can be applied to a substrate surface by any known conventional method, such as spraying, knife coating, roll coating, casting, drum coating, dipping, and combinations thereof. Indirect application using a transfer process can also be used. The substrate can be any commercially suitable 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 metal, paper, cardboard, glass, thermoplastics such as polyolefins, polycarbonates, acrylonitrile butadiene styrene (ABS), and blends thereof, composites, wood, leather, and combinations thereof. When used as an adhesive, the curable composition can be disposed between two substrates and then cured, whereby the cured composition can bond the substrates to form a laminated article. Curable compositions according to the present invention can also be formed or cured in bulk form (e.g., the curable composition can be cast into a suitable mold and then cured).

[0198] Curing can be accelerated or facilitated by providing energy to the curable composition, such as by heating the curable composition and / or exposing the curable composition to a radiation source, such as visible or UV light, infrared light, and / or electron beam radiation. Thus, the cured composition can be considered a reaction product of the curable composition formed by curing. The curable composition can be partially cured by exposure to actinic radiation, and further curing is achieved by heating the partially cured article. For example, an article (e.g., a 3D printed article) formed from the curable composition can be heated at a temperature of 40°C to 120°C for 5 minutes to 12 hours.

[0199] Multiple layers of the curable composition according to the present invention may be applied to a substrate surface. The multiple layers can be cured simultaneously (e.g., by exposure to a single dose of radiation), or each layer can be cured sequentially before applying an additional layer of the curable composition.

[0200] The curable compositions described herein can be used as resins in three-dimensional printing applications. Three-dimensional (3D) printing (sometimes called additive manufacturing) is a method in which 3D digital models are produced by incremental growth of a build material. 3D printed objects are created by utilizing computer-aided design (CAD) data of the object through the sequential construction of two-dimensional (2D) layers or slices corresponding to cross-sections of the 3D object. Stereolithography (SL) is a type of additive manufacturing in which a liquid resin is cured by selective exposure to radiation to form each 2D layer. The radiation can be in the form of electromagnetic waves or an electron beam. The most commonly applied energy sources are ultraviolet, visible, or infrared.

[0201] The curable compositions of the present invention described herein can be used as 3D printing resin formulations, i.e., compositions intended for use in the manufacture of three-dimensional articles using 3D printing processes. Such three-dimensional articles can be freestanding / self-supporting and can consist solely or essentially of the cured compositions of the present invention. The three-dimensional articles can also be composites comprising at least one component consisting solely or essentially of the cured composition described above and at least one additional component (e.g., a metal component or a thermoplastic component) composed of one or more materials other than the cured composition. The curable compositions of the present invention are particularly useful in digital light printing (DLP), although other types of three-dimensional (3D) printing processes (e.g., SLA, inkjet) can also be performed using the curable compositions of the present invention. The curable compositions of the present invention can be used in 3D printing operations with other materials that serve as a scaffold or support for the article formed from the curable compositions of the present invention.

[0202] The curable compositions of the present invention are therefore useful in carrying out various types of three-dimensional fabrication or printing processes, including processes in which the construction of a three-dimensional object is carried out stepwise or layer by layer. In such processes, the formation of a layer can be achieved by solidifying (curing) the curable composition under the action of exposure to radiation, such as visible, UV, or other actinic radiation. For example, a new layer can be formed on the top surface of a growing object or on the bottom surface of a growing object. The curable compositions of the present invention can also be advantageously used in methods for producing three-dimensional objects by additive manufacturing, in which the method is carried out continuously. For example, the object can be produced from a liquid interface. Suitable methods of this type are sometimes referred to in the art as "continuous liquid interface (or interphase) production (or printing)" ("CLIP") processes. Such methods are described, for example, in WO 2014 / 126830; WO 2014 / 126834; WO 2014 / 126837; and Tumbleston et al., "Continuous Liquid Interface Production of 3D Objects," Science, Vol. 347, No. 6228, pp. 1349-1352 (March 20, 2015), the entire disclosures of which are incorporated herein by reference in their entirety for all purposes.

[0203] When stereolithography is performed on an oxygen-permeable build window, the production of articles using the curable composition according to the present invention can be made possible in a CLIP procedure by creating an oxygen-containing "dead zone," a thin, uncured layer of curable composition between the window and the surface of the cured article as the cured article is produced. In such a method, a curable composition is used, and curing (polymerization) is inhibited by the presence of molecular oxygen. Such inhibition is typically observed, for example, in curable compositions that are curable by a free-radical mechanism. The desired dead zone thickness can be maintained by selecting various control parameters, such as the light flux and the optical and cure properties of the curable composition. The CLIP method proceeds by projecting a continuous sequence of actinic (e.g., UV) images (which may be generated, for example, by a digital light processing image processing device) through an oxygen-permeable, actinic (e.g., UV)-transparent window below a bath of the curable composition maintained in liquid form. The liquid interface below the advancing (growing) article is maintained by the dead zone created above the window. The curing article can be continuously withdrawn from the bath of curable composition above the dead zone and replenished by pumping additional amounts of curable composition into the bath to compensate for the amount of curable composition that is being hardened and incorporated into the growing article.

[0204] <Aspects of the present invention> Exemplary, non-limiting embodiments of the present invention can be summarized as follows:

[0205] Aspect 1: A multi(meth)acrylate-functionalized oligomer having a polyurethane backbone, a plurality of (meth)acrylate functional groups pendant to the polyurethane backbone, and one or more terminal (meth)acrylate functional groups, the multi(meth)acrylate-functionalized oligomer being comprised of: a) at least one multi(meth)acrylate-functionalized segment having at least two pendant (meth)acrylate groups; b) a urethane-containing segment; c) at least one end-capping segment having at least one (meth)acrylate group; and optionally, d) at least one chain extension segment having zero or less than one (meth)acrylate group; wherein the at least one multi(meth)acrylate-functionalized segment is located at a position along the polyurethane backbone of the multi(meth)acrylate-functionalized oligomer, and the at least one (meth)acrylate functional group is present at one or more terminal positions of the multi(meth)acrylate-functionalized oligomer.

[0206] Embodiment 2: The multi(meth)acrylate-functionalized oligomer of embodiment 1, comprising at least one chain extending segment selected from the group consisting of a non-polymeric aliphatic segment, a polyether-containing segment, a polyester-containing segment, a polydiene-containing segment, a polycarbonate-containing segment, and a polyorganosiloxane-containing segment.

[0207] Embodiment 3: The multi(meth)acrylate-functionalized oligomer of embodiment 1 or 2, wherein the urethane-containing segment corresponds to formula (I):

[0208] [ka]

[0209] In the formula, R 1 is a divalent hydrocarbon group.

[0210] Embodiment 4: The urethane-containing segment is selected from the group consisting of tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, 4,4'-methylenebis(cyclohexylisocyanate), methylcyclohexane-2,4-diisocyanate, methylcyclohexane-2,6-diisocyanate, 1,3-(isocyanatomethyl)cyclohexane, isocyanate, methylcyclohexane-2,6-diisocyan ... Sophorone diisocyanate, trimethylhexamethylene diisocyanate, dimer acid diisocyanate, dianisidine diisocyanate, phenyl diisocyanate, halogenated phenyl diisocyanate, methylene diisocyanate, ethylene diisocyanate, butylene diisocyanate, propylene diisocyanate, octadecylene diisocyanate, 1,5-naphthalene diisocyanate, polymethylene polyphenylene diisocyanate, tolylene diisocyanate polymer, diphenyl methacrylate Diisocyanate polymer, hexamethylene diisocyanate polymer, 3-phenyl-2-ethylene diisocyanate, cumene-2,4-diisocyanate, 4-methoxy-1,3-phenylene diisocyanate, 4-ethoxy-1,3-phenylene diisocyanate, 2,4'-diisocyanate diphenyl ether, 5,6-dimethyl-1,3-phenylene diisocyanate, 4,4'-diisocyanate diphenyl ether, benzidine diisocyanate, 9,10-anthracene diisocyanate ester, 4,4'-diisocyanate benzyl, 3,3'-dimethyl-4,4'-diisocyanate diphenylmethane, 2,6'-dimethyl-4,4'-diisocyanate diphenyl, 3,3'-dimethoxy-4,4'-diisocyanate diphenyl, 1,4-anthracene diisocyanate, phenylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,10-decamethylene diisocyanate, 1,3-cyclohexylene diisocyanate, 4,The multi(meth)acrylate-functionalized oligomer of any one of embodiments 1 to 3, comprising a residue of a diisocyanate selected from the group consisting of 4′-methylene-bis(cyclohexylisocyanate), and combinations thereof.

[0211] Embodiment 5: The multi(meth)acrylate-functionalized oligomer of any one of embodiments 1 to 4, comprising at least one multi(meth)acrylate-functionalized segment corresponding to formula (IIa):

[0212] [ka]

[0213] In the formula, R 2 and R 4 are the same or different, -CH2-OC(=O)-CR 5 =CH2(wherein, R 5 is H or CH3), and R 3 is a divalent organic group.

[0214] Aspect 6: R 3 But -R 3’ -or-CH2-OR 3’ -O-CH2-, and R 3’ The multi(meth)acrylate-functionalized oligomer of embodiment 5, wherein is a divalent hydrocarbon group.

[0215] Embodiment 7: The multi(meth)acrylate-functionalized oligomer of embodiments 1 to 6, comprising at least one multi(meth)acrylate-functionalized segment corresponding to formula (IIb):

[0216] [ka]

[0217] In the formula, R 2 and R 4 and R 10 are the same or different, -CH2-OC(=O)-CR 5=CH2(wherein, R 5 is H or CH3), and R 3 is a trivalent organic group, and the wavy line represents the point of attachment to another segment of the oligomer, particularly the urethane-containing segment.

[0218] Aspect 8:R 3 But -R 3’ - or R 3 is represented by formula (IIb'):

[0219] [ka]

[0220] (In the formula, R 3’ is a trivalent hydrocarbon group) The multi(meth)acrylate-functionalized oligomer of embodiment 7, corresponding to:

[0221] Embodiment 9: The multi(meth)acrylate-functionalized oligomer of any one of embodiments 1 to 8, comprising at least one chain extender segment that is a polymer-containing segment.

[0222] Embodiment 10: The multi(meth)acrylate-functionalized oligomer of embodiment 9, wherein the polymer-containing segment corresponds to formula (III):

[0223] [ka]

[0224] In the formula, R 6 is a divalent polymer moiety selected from the group consisting of polyether groups, polyester groups, polydiene groups, polycarbonate groups, and polyorganosiloxane groups.

[0225] Embodiment 11: The multi(meth)acrylate-functionalized oligomer of embodiment 10, wherein the divalent polymeric group is a divalent polyether group selected from the group consisting of a divalent polyoxyethylene group, a divalent polyoxypropylene group, a divalent polyoxyethylene / oxypropylene group, and a divalent polyoxytetramethylene group.

[0226] Embodiment 12: The multi(meth)acrylate-functionalized oligomer of any one of embodiments 1 to 11, comprising at least one chain extender segment that is a non-polymeric aliphatic segment.

[0227] Embodiment 13: The multi(meth)acrylate-functionalized oligomer of embodiment 12, wherein the non-polymeric aliphatic segment corresponds to formula (IIIa):

[0228] [ka]

[0229] In the formula, R 6a is a divalent non-polymeric aliphatic hydrocarbon group which may optionally additionally contain one or more heteroatoms.

[0230] Embodiment 14: The multi(meth)acrylate-functionalized oligomer of any one of embodiments 1 to 13, wherein at least one end cap segment has a structure corresponding to formula (IV):

[0231] [ka]

[0232] In the formula, R 7 is an n+1 valent organic group, and R 8 is H or CH3, and n is an integer of 1 to 3.

[0233] Aspect 15: n=1 and R 7 is -CH2-CH2- or -(CH2)5-C(=O)-[O-(CH2)5-C(=O)] xThe multi(meth)acrylate-functionalized oligomer of embodiment 14, wherein the multi(meth)acrylate-functionalized oligomer is —O—CH 2 —CH 2 —, where x is an integer from 0 to 9.

[0234] Embodiment 16: The multi(meth)acrylate-functionalized oligomer of any one of embodiments 1 to 15, having a number average molecular weight of 3000 to 20,000 g / mol.

[0235] Embodiment 17: The multi(meth)acrylate-functionalized oligomer of any one of embodiments 1 to 16, wherein the chain extension segment and the multi(meth)acrylate-functionalized segment are present in a molar ratio of 0:1 to 10:1.

[0236] Embodiment 18: The multi(meth)acrylate-functionalized oligomer of any one of embodiments 1 to 17, wherein the urethane-containing segment is disposed between and links together the multiple multi(meth)acrylate-functionalized segments.

[0237] Embodiment 19: The multi(meth)acrylate-functionalized oligomer of any one of embodiments 1 to 18, wherein one or more chain extender segments are present and wherein a urethane-containing segment is disposed between and links together the multi(meth)acrylate-functionalized segment and the chain extender segment.

[0238] Embodiment 20: The multi(meth)acrylate-functionalized oligomer of any one of embodiments 1 to 19, wherein the urethane-containing segment is disposed between and links together the end-capping segment and the multi(meth)acrylate-functionalized segment, and / or, if one or more chain extending segments are present, disposed between and links together the end-capping segment and the chain extending segment.

[0239] Embodiment 21: The multi(meth)acrylate-functionalized oligomer of any one of embodiments 1 to 20, wherein one or more chain extender segments are present, and wherein the chain extender segments and the multi(meth)acrylate-functionalized segments are randomly positioned along the polyurethane backbone and linked together by urethane-containing segments.

[0240] Embodiment 22: The multi(meth)acrylate-functionalized oligomer of any one of embodiments 1 to 21, comprising one or more units of formula (A2):

[0241] [ka]

[0242] In the formula, R 1 is a divalent hydrocarbon group, and R 2 and R 4 are the same or different, -CH2-OC(=O)-CR 5 =CH2(wherein, R 5 is H or CH3), and R 3 is a divalent organic group.

[0243] Embodiment 23: The multi(meth)acrylate-functionalized oligomer of embodiment 22, additionally comprising one or more units of formula (B):

[0244] [ka]

[0245] In the formula, R 1 is a divalent hydrocarbon group, and R 6 is a divalent polymeric group selected from the group consisting of a divalent polyether group, a divalent polyester group, a divalent polydiene group, a divalent polycarbonate group, and a divalent polyorganosiloxane group.

[0246] Embodiment 24: The multi(meth)acrylate-functionalized oligomer of embodiment 22 or 23, additionally comprising one or more units of formula (B'):

[0247] [ka]

[0248] In the formula, R 1 is a divalent hydrocarbon group, and R 6a is a divalent non-polymeric aliphatic group that may optionally additionally contain one or more heteroatoms.

[0249] Embodiment 25: The multi(meth)acrylate-functionalized oligomer of embodiments 1 to 24, comprising one or more units of formula (A3):

[0250] [ka]

[0251] In the formula, R 1 is a divalent hydrocarbon group; R 2 , R 4 , and R 10 are the same or different, and -CH2-OC(=O)-CR 5 =CH2(wherein, R 5 is H or CH; R 3 is a trivalent organic group; the wavy line represents the point of attachment to another segment of the oligomer, particularly the urethane-containing segment).

[0252] Embodiment 26: The multi(meth)acrylate-functionalized oligomer of embodiment 25, additionally comprising one or more units of formula (B):

[0253] [ka]

[0254] In the formula, R 1is a divalent hydrocarbon group, and R 6 is a divalent polymeric group selected from the group consisting of a divalent polyether group, a divalent polyester group, a divalent polydiene group, a divalent polycarbonate group, and a divalent polyorganosiloxane group.

[0255] Aspect 27: The urethane-containing segment has the following formula (I):

[0256] [ka]

[0257] (In the formula, R 1 is a divalent hydrocarbon group) Corresponding to; At least one multi(meth)acrylate functionalized segment has the following formula (IIa):

[0258] [ka]

[0259] [In the formula, R 2 and R 4 are the same or different, -CH2-OC(=O)-CR 5 =CH2(wherein, R 5 is H or CH3), and R 3 is a divalent organic group. corresponds to; and The optional chain extender segment, if present, may be of the following formula (III):

[0260] [ka]

[0261] (In the formula, R 6is a divalent polymer radical selected from the group consisting of a divalent polyether radical, a divalent polyester radical, a divalent polydiene radical, a divalent polycarbonate radical, and a divalent polyorganosiloxane radical), or the following formula (IIIa):

[0262] [ka]

[0263] (In the formula, R 6a is a divalent non-polymeric aliphatic group that may optionally additionally contain one or more heteroatoms. The multi(meth)acrylate-functionalized oligomer of any one of embodiments 1 to 6 and embodiments 9 to 24, wherein the multi(meth)acrylate-functionalized oligomer corresponds to at least one of:

[0264] Aspect 28: A multi(meth)acrylate-functionalized oligomer having a polyurethane backbone, a plurality of (meth)acrylate functional groups pendant to the polyurethane backbone, and one or more terminal (meth)acrylate functional groups, the multi(meth)acrylate-functionalized oligomer being the reaction product of reactants comprising: a) at least one diisocyanate; b) at least one diol compound having at least two (meth)acrylate functional groups or at least one triol compound having at least three (meth)acrylate functional groups, or a mixture thereof; c) at least one end-capping compound having one isocyanate-reactive hydroxyl group and at least one (meth)acrylate functional group; and optionally, d) at least one chain-extending polyol having at least two hydroxyl groups and from 0 to 1 (meth)acrylate functional groups.

[0265] Embodiment 29: The multi(meth)acrylate-functionalized oligomer of embodiment 28, wherein b) comprises at least one diol compound, and the diol compound is a reaction product of reactants comprising an acid-functionalized (meth)acrylate and a diepoxide.

[0266] Embodiment 30: The multi(meth)acrylate-functionalized oligomer of embodiment 28 or 29, wherein b) comprises at least one triol compound, and the triol compound is a reaction product of reactants comprising an acid-functionalized (meth)acrylate and a triepoxide.

[0267] Embodiment 31: The multi(meth)acrylate-functionalized oligomer of embodiment 29 or 30, wherein the acid-functionalized (meth)acrylate has a structure corresponding to formula (V):

[0268] [ka]

[0269] In the formula, R is H or CH3, and n is an integer of 0 to 5.

[0270]

[0039] Embodiment 32: The multi(meth)acrylate-functionalized oligomer of embodiment 29, wherein the diepoxide is selected from the group consisting of diene diepoxides and diglycidyl ethers.

[0271] Example 33: The multi(meth)acrylate-functionalized oligomer of any of Examples 28, 29, 31, or 32, wherein the diol compound is 1,4-bis(3-acryloyloxy-2-hydroxypropoxy)butane.

[0272] Embodiment 34: The multi(meth)acrylate-functionalized oligomer of any of embodiments 28 to 33, wherein the end-capping compound is selected from the group consisting of (meth)acrylates of polyols, all but one hydroxyl group of which is (meth)acrylated.

[0273] Embodiment 35: The multi(meth)acrylate-functionalized oligomer of any of embodiments 28 to 34, wherein the end-capping compound is selected from the group consisting of hydroxyalkyl(meth)acrylates.

[0274] Embodiment 36: The multi(meth)acrylate-functionalized oligomer of any one of embodiments 28 to 35, wherein the reactant feed comprises at least one chain-extended polyol selected from the group consisting of non-polymeric aliphatic diols, polyether polyols, polyester polyols, polydiene polyols, polycarbonate polyols, and polyorganosiloxane polyols having at most one (meth)acrylate functional group per molecule.

[0275] Aspect 37: A method of making a multi(meth)acrylate-functionalized oligomer having a polyurethane backbone, a plurality of (meth)acrylate functional groups pendant to the polyurethane backbone, and one or more terminal (meth)acrylate functional groups, the method comprising reacting a) at least one diisocyanate, b) at least one diol compound having at least two (meth)acrylate functional groups, c) at least one end-capping compound having one isocyanate-reactive hydroxyl group and at least one (meth)acrylate functional group, and optionally d) at least one chain-extending polyol having at least two hydroxyl groups and zero or one (meth)acrylate functional group.

[0276] Embodiment 38: A curable composition comprising at least one multi(meth)acrylate-functionalized oligomer of any one of embodiments 1 to 36 and at least one of a) a photoinitiator or b) a curable compound other than the multi(meth)acrylate-functionalized oligomer of any one of embodiments 1 to 36.

[0277] While embodiments have been described herein in a manner that enables a clear and concise specification to be written, it is intended and recognized that the embodiments may be combined or separated in various ways without departing from the invention. For example, it is recognized that all preferred features described herein are applicable to all aspects of the invention described herein.

[0278] In some embodiments, the invention herein may be construed to exclude any element or process step that does not materially affect the basic and novel characteristics of the methods and compositions described herein. Moreover, in some embodiments, the invention may be construed to exclude any element or process step not specified herein.

[0279] Although the invention has been illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications in the details can be made, within the scope and range of equivalents of the claims, without departing from the invention. [Example]

[0280] Examples 1-3 demonstrate the preparation of acrylate-functional urethane oligomers having acrylate functional groups located pendant to the oligomer chain but not at a terminal position of the oligomer chain. Such acrylate-functional urethane oligomers can be used as intermediates in the preparation of multi(meth)acrylate-functionalized oligomers according to the invention by reacting the terminal groups of such oligomers with (meth)acrylate functional groups to end-cap the oligomer, as exemplified in Example 4.

[0281] (Example 1) Polypropylene glycol (Carpenter, Carpol® PGP2000-60 polyol) (724.0 g) having a number-average molecular weight of approximately 2000 g / mol, 1,4-bis(3-acryloyloxy-2-hydroxypropoxy)butane (Sartomer, CN132) (152.7 g), isophorone diisocyanate (Covestro, Desmodur® I) (121.0 g), and butylated hydroxytoluene (Aldrich) (2.0 g) were charged to a reactor and stirred at room temperature for 5 minutes. An air sparge was applied. Dibutyltin dilaurate (Aldrich) (0.3 g) was then added to the mixture. The reaction was exothermic. When the pot temperature stopped increasing, the mixture was carefully heated to 80°C with vigorous stirring and air sparging, then held at 80°C for 4 hours or until the residual NCO content was less than 0.06%. The yield was 1000 grams. Example 4 illustrates how this oligomer can be converted to a multi(meth)acrylate-functionalized oligomer according to the present invention.

[0282] (Example 2) Poly(neopentyl glycol adipate) polyol (Coim, Diexter-G 5500-56) (739.9 g) with a number-average molecular weight of approximately 2000 g / mol, 1,4-bis(3-acryloyloxy-2-hydroxypropoxy)butane (Sartomer, CN132) (133.1 g), isophorone diisocyanate (Covestro, Desmodur I) (123.4 g), and Irganox® 1035 (BASF) (3.0 g) were placed in a reactor and heated to 60°C with vigorous stirring. An air sparge was applied. Bismuth neodecanoate (Reaxis, C716) (0.6 g) was then added to the mixture when the pot temperature reached 60°C. The reaction was exothermic. When the pot temperature stopped increasing, the mixture was carefully heated with vigorous stirring and air sparging to 105°C, then held at 105°C for 2 hours or until the residual NCO was less than 0.06%. The yield was 1000 grams.

[0283] (Example 3) Trimethylolpropane triglycidyl ether triacrylate (Sartomer, CN133) (866.1 g), bismuth(3+) neodecanoate (Reaxis, C716) (0.6 g), and butylated hydroxytoluene (Aldrich) (2.0 g) were charged to a reactor. The mixture was carefully heated to 65°C with vigorous stirring and air sparging. Isophorone diisocyanate (Covestro, Desmodur® I) (131.3 g) was metered into the reactor over 2 hours. The reaction was exothermic. The pot temperature was allowed to reach 95°C and then held at 95°C for 1 hour or until the residual NCO was less than 0.06%. The yield was 1000 grams.

[0284] Examples 4-9 demonstrate the synthesis of acrylate-functional urethane oligomers in accordance with the present invention, with acrylate functional groups located both pendant to the oligomer chain and at the terminus of the oligomer chain.

[0285] (Example 4) The final product from Example 1 (888.7 g), 2-hydroxyethyl acrylate (Nippon Shokubai Co., Ltd.) (38.2 g), and isophorone diisocyanate (Covestro, Desmodur® I) (73.1 g) were mixed in a reactor at room temperature. An air sparge was applied. The reaction was exothermic. When the pot temperature stopped increasing, the mixture was carefully heated to 95°C with vigorous stirring and air sparging, then held at 95°C for 4 hours or until the residual NCO was less than 0.06%. The yield was 1000 grams.

[0286] (Example 5) 2-Hydroxyethyl acrylate (Nippon Shokubai Co., Ltd.) (38.2 g), 1,4-bis(3-acryloyloxy-2-hydroxypropoxy)butane (Sartomer Co., Ltd., CN132) (118.0 g), polypropylene glycol having a number-average molecular weight of approximately 2000 g / mol (Carperter Co., Carpol® PGP2000-60 polyol) (657.3 g), isophorone diisocyanate (Covestro Co., Desmodur® I) (182.6 g), and butylated hydroxytoluene (Aldrich Co., Ltd.) (3 g) were added to a reactor and stirred at room temperature for 5 minutes. An air sparge was applied. Dibutyltin dilaurate (Aldrich Co., Ltd.) (0.9 g) was then added to the mixture. The reaction was exothermic. When the pot temperature stopped increasing, the mixture was carefully heated to 95°C with vigorous stirring and air sparging, then held at 95°C for 4 hours or until the residual NCO was less than 0.06%. The yield was 1000 grams.

[0287] (Example 6) Caprolactone-modified 2-hydroxyethyl acrylate (Sartomer, SR495B) (493.6 g), 1,4-bis(3-acryloyloxy-2-hydroxypropoxy)butane (Sartomer, CN132) (257.5 g), hexamethylene diisocyanate (Covestro, Desmodur® H) (245.2 g), and butylated hydroxytoluene (Aldrich) (3.0 g) were added to a reactor and stirred at room temperature for 5 minutes. An air sparge was applied. Dibutyltin dilaurate (Aldrich) (0.7 g) was then added to the mixture. The reaction was exothermic. When the pot temperature stopped increasing, the mixture was carefully heated to 90°C with vigorous stirring and air sparging, and then held at 90°C for 9 hours or until the residual NCO content was less than 0.06%. The yield was 1000 grams.

[0288] (Example 7) Caprolactone-modified 2-hydroxyethyl acrylate (Sartomer, SR495B) (109.4 g), 1,4-bis(3-acryloyloxy-2-hydroxypropoxy)butane (Sartomer, CN132) (114.0 g), polypropylene glycol having a number-average molecular weight of approximately 2000 g / mol (Carpenter, Carpol® PGP2000-60 polyol) (635.0 g), hexamethylene diisocyanate (Covestro, Desmodur® H) (137.9 g), and butylated hydroxytoluene (Aldrich) (3.0 g) were added to a reactor and stirred at room temperature for 5 minutes. An air sparge was applied. Dibutyltin dilaurate (Aldrich) (0.7 g) was then added to the mixture. The reaction was exothermic. When the pot temperature stopped increasing, the mixture was carefully heated to 90°C with vigorous stirring and air sparging, then held at 90°C for 9 hours or until the residual NCO was less than 0.06%. The yield was 1000 grams.

[0289] (Example 8) 2-Hydroxyethyl acrylate (Nippon Shokubai Co., Ltd.) (37.7 g), 1,4-bis(3-acryloyloxy-2-hydroxypropoxy)butane (Sartomer Co., Ltd., CN132) (118.2 g), poly(neopentyl glycol adipate) polyol (Coim Co., Ltd., Diexter-G 5500-56) (659.0 g) having a number-average molecular weight of approximately 2000 g / mol, isophorone diisocyanate (Covestro Co., Ltd., Desmodur® I) (181.5 g), and Irganox® 1035 (BASF Co., Ltd.) (3.0 g) were placed in a reactor and heated to 60°C with vigorous stirring. An air sparge was applied. Bismuth neodecanoate (Reaxis Co., Ltd., C716) (0.6 g) was then added to the mixture when the pot temperature reached 60°C. The reaction was exothermic. When the pot temperature stopped increasing, the mixture was carefully heated with vigorous stirring and air sparging to 105°C, then held at 105°C for 2 hours or until the residual NCO was less than 0.06%. The yield was 1000 grams.

[0290] (Example 9) Isophorone diisocyanate (Covestro, Desmodur® I) (177.2 g), Irganox® 1035 (BASF) (3.0 g), and dibutyltin dilaurate (Aldrich) (0.9 g) were added to a reactor and stirred at room temperature for 5 minutes. An air sparge was applied. 1,4-bis(3-acryloyloxy-2-hydroxypropoxy)butane (Sartomer, CN132) (143.0 g) was metered into the mixture over 30 minutes. The reaction was exothermic. The pot temperature was allowed to reach 60°C and then held at 60°C with vigorous stirring and air sparging for 30 minutes or until the NCO reached a range of 10.1-10.4%. The mixture was transferred to a capped 16-oz. brown bottle labeled A. Polycarbonate polyol (UBE, Eternacoll® UH-50) (406.5 g) with a number-average molecular weight of approximately 500 g / mol was pre-melted in a 60°C oven and placed in a separate, clean reactor, which was then heated to 60°C with vigorous stirring. When the pot temperature reached 60°C, an air sparge was applied, and the previously prepared isocyanate-terminated prepolymer A was gradually added to the reactor in 10 portions over 1 hour. The pot temperature was allowed to reach 90°C and then held at 90°C with vigorous stirring and air sparging for 30 minutes or until NCO = 0. Next, a hemiadduct of isophorone diisocyanate and 2-hydroxyethyl acrylate (Evonik, VESTANAT EP-DC 1241) (269.4 g) was added to the mixture over 30 minutes with vigorous stirring and air sparging. The pot temperature was allowed to reach 105°C and then held at 105°C with vigorous stirring and air sparging for 2 hours or until the NCO was less than 0.06%. The yield was 1000 grams.

[0291] Table 1 lists some properties of the oligomers described in the above examples and the UV-cured products obtained from them. Included for comparison purposes is CO-1, a low-Tg, conventional terminal ("telechelic") acrylated urethane oligomer (i.e., an oligomer having terminal acrylate functionality but no acrylate functionality pendant to the oligomer backbone). The molecular weight values ​​reported in Table 1 were obtained using an Agilent 1260 GPC equipped with a refractive index detector and polystyrene calibration standards.

[0292] [Table 1]

[0293] The oligomer of Example 1 was similar in molecular weight to CO-1, but its viscosity at 60°C was significantly lower than that of CO-1. ​​The oligomer of Example 5 had a similar molecular weight to CO-1, and the glass transition temperatures (Tg) of these oligomers when cured were also similar. However, the oligomer of Example 5 yielded a cured product with a significantly higher Young's modulus and tensile strength than the cured product obtained from the CO-1 oligomer. Without wishing to be bound by theory, it is believed that the significant enhancement in mechanical properties observed in the case of the oligomer of Example 5 is due to the presence of both pendant and terminal acrylate functional groups.

[0294] (Example 10) Dicyclohexylmethane-4,4'-diisocyanate (Covestro, Desmodur® W) (319.2 g), butylated hydroxytoluene (Aldrich) (1.0 g), 1,4-bis(3-acryloyloxy-2-hydroxypropoxy)butane (Sartomer, CN132) (100.0 g), trimethylolpropane triglycidyl ether triacrylate (Sartomer, CN133) (100.0 g), and caprolactone-modified 2-hydroxyethyl acrylate (Sartomer, SR495B) (100.0 g) were added to a reactor and stirred at room temperature for 5 minutes. An air sparge was applied. Dibutyltin dilaurate (Aldrich) (0.9 g) was then added to the mixture. The reaction was exothermic. When the pot temperature stopped increasing, the mixture was held at 65-70°C with vigorous stirring and air sparging for 30 minutes or until the NCO reached a range of 10.6-11.2%. Additional caprolactone-modified 2-hydroxyethyl acrylate (Sartomer, SR495B) (378.9 g) was then metered into the mixture over 1 hour. The pot temperature was allowed to reach 90°C and then held at 90°C with vigorous stirring and air sparging for 4 hours or until the NCO reached less than 0.06%. The yield was 1000 grams.

[0295] (Example 11) Dicyclohexylmethane-4,4'-diisocyanate (Covestro, Desmodur® W) (323.7 g), butylated hydroxytoluene (Aldrich) (1.0 g), trimethylolpropane triglycidyl ether triacrylate (Sartomer, CN133) (247.5 g), and caprolactone-modified 2-hydroxyethyl acrylate (Sartomer, SR495B) (426.9 g) were added to a reactor and stirred at room temperature for 5 minutes. An air sparge was applied. Dibutyltin dilaurate (Aldrich) (0.9 g) was then added to the mixture. The reaction was exothermic. When the pot temperature stopped increasing, the mixture was carefully heated to 90°C with vigorous stirring and air sparging, then held at 90°C for 4 hours or until the residual NCO content was less than 0.06%. The yield was 1000 grams.

[0296] (Example 12) Isophorone diisocyanate (Covestro, Desmodur® I) (237.3 g), Irganox® 1035 (BASF) (2.0 g), and dibutyltin dilaurate (Aldrich) (0.6 g) were added to a reactor and stirred at room temperature for 5 minutes. An air sparge was applied. 2-Hydroxyethyl acrylate (Nippon Shokubai Co., Ltd.) (62.0 g) was metered into the mixture over 30 minutes. The reaction was exothermic. The pot temperature was allowed to reach 50°C and then held at 50°C with vigorous stirring and air sparging for 30 minutes or until the NCO reached the range of 22.0-23.0%. Polycarbonate polyol (UBE, Eternacoll® UH-50) (272.1 g) with a number-average molecular weight of approximately 500 g / mol was pre-melted in a 60°C oven and then metered into the mixture over 1 hour. The pot temperature was allowed to reach 70°C and then held at 70°C with vigorous stirring and air sparging for 1 hour or until the NCO reached a range of 4.0-4.5%. Acetone (VWR) (319.1 g) was added to the mixture to prevent it from becoming too viscous. Trimethylolpropane triglycidyl ether triacrylate (Sartomer, CN133) (106.9 g) was added to the mixture. The pot temperature was held at 65°C with vigorous stirring and air sparging for 8 hours or until the NCO reached less than 0.06%. The yield was 1000 grams (680.9 grams of dry resin).

Claims

1. 1. A multi(meth)acrylate-functionalized oligomer having a polyurethane backbone, a plurality of (meth)acrylate functional groups pendant to the polyurethane backbone, and one or more terminal (meth)acrylate functional groups, the multi(meth)acrylate-functionalized oligomer consisting of: a) at least one multi(meth)acrylate-functionalized segment having at least two pendant (meth)acrylate groups; b) a urethane-containing segment; c) at least one end cap segment having at least one (meth)acrylate group; and optionally, d) at least one chain extender segment having no (meth)acrylate groups or no more than one (meth)acrylate group; wherein the at least one multi(meth)acrylate-functionalized segment is disposed at a position along the polyurethane backbone of the multi(meth)acrylate-functionalized oligomer, and the at least one (meth)acrylate functional group is present at one or more terminal positions of the multi(meth)acrylate-functionalized oligomer.

2. 10. The multi(meth)acrylate-functionalized oligomer of claim 1, comprising at least one chain extending segment selected from the group consisting of a non-polymeric aliphatic segment, a polyether-containing segment, a polyester-containing segment, a polydiene-containing segment, a polycarbonate-containing segment, and a polyorganosiloxane-containing segment.

3. The urethane-containing segment is represented by formula (I): 【Chemical 1】 (In the formula, R １ is a divalent hydrocarbon group) 3. The multi(meth)acrylate-functionalized oligomer of claim 1 or 2, wherein:

4. The urethane-containing segment may be selected from the group consisting of tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), methylcyclohexane-2,4-diisocyanate, methylcyclohexane-2,6-diisocyanate, 1,3-(isocyanatomethyl)cyclohexane, isophorone, Diisocyanate, trimethylhexamethylene diisocyanate, dimer acid diisocyanate, dianisidine diisocyanate, phenyl diisocyanate, halogenated phenyl diisocyanate, methylene diisocyanate, ethylene diisocyanate, butylene diisocyanate, propylene diisocyanate, octadecylene diisocyanate, 1,5-naphthalene diisocyanate, polymethylene polyphenylene diisocyanate, tolylene diisocyanate polymer, diphenylmethane diisocyanate Isocyanate polymer, hexamethylene diisocyanate polymer, 3-phenyl-2-ethylene diisocyanate, cumene-2,4-diisocyanate, 4-methoxy-1,3-phenylene diisocyanate, 4-ethoxy-1,3-phenylene diisocyanate, 2,4'-diisocyanate diphenyl ether, 5,6-dimethyl-1,3-phenylene diisocyanate, 4,4'-diisocyanate diphenyl ether, benzidine diisocyanate, 9,10-anthracene diisocyanate 4,4'-diisocyanate benzyl, 3,3'-dimethyl-4,4'-diisocyanate diphenylmethane, 2,6'-dimethyl-4,4'-diisocyanate diphenyl, 3,3'-dimethoxy-4,4'-diisocyanate diphenyl, 1,4-anthracene diisocyanate, phenylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,10-decamethylene diisocyanate, 1,3-cyclohexylene diisocyanate, 4,The multi(meth)acrylate-functionalized oligomer of any one of claims 1 to 3, comprising residues of a diisocyanate selected from the group consisting of 4'-methylene-bis(cyclohexyl isocyanate), and combinations thereof.

5. The following formula (IIa): 【Chemistry 2】 [In the formula, R ２ and R ４ are the same or different, and —CH ２ -OC(=O)-CR ５ =CH ２ (In the formula, R ５ is H or CH ３ ) and R ３ is a divalent organic group.

5. The multi(meth)acrylate-functionalized oligomer of claim 1, comprising at least one multi(meth)acrylate-functionalized segment corresponding to:

6. R ３ But, -R ３’ - or -CH ２ -O-R ３’ -O-CH ２ - and R ３’ The multi(meth)acrylate-functionalized oligomer of claim 5 , wherein is a divalent hydrocarbon group.

7. The following formula (IIb): 【Chemistry 3】 [In the formula, R ２ and R ４ and R １０ are the same or different, and —CH ２ -OC(=O)-CR ５ =CH ２ (In the formula, R ５ is H or CH ３ ) and R ３ is a trivalent organic group, and the wavy line represents the point of attachment to another segment of the oligomer, particularly a urethane-containing segment.

7. The multi(meth)acrylate-functionalized oligomer of claim 1, comprising at least one multi(meth)acrylate-functionalized segment corresponding to:

8. R ３ But, -R ３’ - or R ３ is represented by the following formula (IIb'): 【Chemistry 4】 (In the formula, R ３’ is a trivalent hydrocarbon group) 8. The multi(meth)acrylate-functionalized oligomer of claim 7, which corresponds to:

9. 9. The multi(meth)acrylate-functionalized oligomer of claim 1, comprising at least one chain-extending segment that is a polymer-containing segment.

10. The polymer-containing segment has the following formula (III): 【Chemistry 5】 (In the formula, R ６ is a divalent polymer group selected from the group consisting of polyether groups, polyester groups, polydiene groups, polycarbonate groups, and polyorganosiloxane groups.

10. The multi(meth)acrylate-functionalized oligomer of claim 9, which corresponds to:

11. 11. The multi(meth)acrylate-functionalized oligomer of claim 10, wherein the divalent polymeric group is a divalent polyether group selected from the group consisting of divalent polyoxyethylene groups, divalent polyoxypropylene groups, divalent polyoxyethylene / oxypropylene groups, and divalent polyoxytetramethylene groups.

12. 12. The multi(meth)acrylate-functionalized oligomer of claim 1, comprising at least one chain extender segment that is a non-polymeric aliphatic segment.

13. The non-polymeric aliphatic segment has the following formula (IIIa): 【Chemistry 6】 (In the formula, R ６ａ is a divalent non-polymeric aliphatic hydrocarbon group which may optionally additionally contain one or more heteroatoms.

13. The multi(meth)acrylate-functionalized oligomer of claim 12, which corresponds to:

14. The following formula (IV): 【Chemistry 7】 (In the formula, R ７ is an (n+1)-valent organic group, and R ８ is H or CH ３ and n is an integer from 1 to 3.

14. The multi(meth)acrylate-functionalized oligomer of claim 1, comprising at least one end cap segment having a structure corresponding to:

15. n=1 and R ７ But -CH ２ CH ２ - or - (CH ２ ) ５ C(=O)[O-(CH ２ ) ５ C(=O)] ｘ OCH ２ CH ２ 15. The multi(meth)acrylate-functionalized oligomer of claim 14, wherein x is an integer from 0 to 9.

16. 16. The multi(meth)acrylate-functionalized oligomer of any one of claims 1 to 15, having a number average molecular weight of 3000 to 20,000 g / mol.

17. 17. The multi(meth)acrylate-functionalized oligomer of any one of claims 1 to 16, wherein the chain extension segment and the multi(meth)acrylate-functionalized segment are present in a molar ratio of 0:1 to 10:

1.

18. 18. The multi(meth)acrylate-functionalized oligomer of claim 1, wherein the urethane-containing segment is disposed between and links together a plurality of the multi(meth)acrylate-functionalized segments.

19. 19. The multi(meth)acrylate-functionalized oligomer of claim 1, wherein one or more chain extender segments are present and a urethane-containing segment is disposed between and links together the multi(meth)acrylate-functionalized segment and the chain extender segment.

20. 20. The multi(meth)acrylate-functionalized oligomer of claim 1, wherein the urethane-containing segment is disposed between and links together the end-capping segment and the multi(meth)acrylate-functionalized segment, and / or, when one or more chain extending segments are present, between and links together the end-capping segment and the chain extending segment.

21. 21. The multi(meth)acrylate-functionalized oligomer of any one of claims 1 to 20, wherein one or more chain extender segments are present, and the chain extender segments and the multi(meth)acrylate-functionalized segments are randomly positioned along the polyurethane backbone and linked together by urethane-containing segments.

22. The following formula (A2): 【Chemistry 8】 [In the formula, R １ is a divalent hydrocarbon group, and R ２ and R ４ are the same or different and are —CH ２ -OC(=O)-CR ５ =CH ２ (In the formula, R ５ is H or CH ３ ) and R ３ is a divalent organic group.

22. The multi(meth)acrylate-functionalized oligomer of claim 1, comprising one or more units of:

23. Additionally, the following formula (B): 【Chemistry 9】 (In the formula, R １ is a divalent hydrocarbon group, and R ６ is a divalent polymer radical selected from the group consisting of a divalent polyether radical, a divalent polyester radical, a divalent polydiene radical, a divalent polycarbonate radical, and a divalent polyorganosiloxane radical.

23. The multi(meth)acrylate-functionalized oligomer of claim 22, comprising one or more units of:

24. Additionally, the following formula (B'): 【Chemistry 10】 (In the formula, R １ is a divalent hydrocarbon group, and R ６ａ is a divalent non-polymeric aliphatic group which may optionally additionally contain one or more heteroatoms.

24. The multi(meth)acrylate-functionalized oligomer of claim 22 or 23, comprising one or more units of:

25. The following formula (A3): 【Chemistry 11】 [In the formula, R １ is a divalent hydrocarbon group, and R ２ and R ４ and R １０ are the same or different, and —CH ２ -OC(=O)-CR ５ =CH ２ (In the formula, R ５ is H or CH ３ ) and R ３ 25. The multi(meth)acrylate-functionalized oligomer of claim 1, comprising one or more units of the formula:

26. Additionally, the following formula (B): 【Chemistry 12】 (In the formula, R １ is a divalent hydrocarbon group, and R ６ is a divalent polymer group selected from the group consisting of a divalent polyether group, a divalent polyester group, a divalent polydiene group, a divalent polycarbonate group, and a divalent polyorganosiloxane group.

26. The multi(meth)acrylate-functionalized oligomer of claim 25, comprising one or more units of:

27. The urethane-containing segment is represented by the following formula (I): 【Chemistry 13】 (In the formula, R １ is a divalent hydrocarbon group) Corresponding to; At least one multi(meth)acrylate functionalized segment has the following formula (IIa): 【Chemistry 14】 [In the formula, R ２ and R ４ are the same or different, and —CH ２ -OC(=O)-CR ５ =CH ２ (In the formula, R ５ is H or CH ３ ) and R ３ is a divalent organic group. corresponds to; and The optional chain extender segment, if present, has the following formula (III): 【Chemistry 15】 (In the formula, R ６ is a divalent polymer group selected from the group consisting of a divalent polyether group, a divalent polyester group, a divalent polydiene group, a divalent polycarbonate group, and a divalent polyorganosiloxane group), or 【Chemistry 16】 (In the formula, R ６ａ is a divalent non-polymeric aliphatic group which may optionally additionally contain one or more heteroatoms.

25. The multi(meth)acrylate-functionalized oligomer of any one of claims 1 to 6 and claims 9 to 24, wherein the multi(meth)acrylate-functionalized oligomer corresponds to at least one of:

28. 1. A multi(meth)acrylate-functionalized oligomer having a polyurethane backbone, a plurality of (meth)acrylate functional groups pendant to the polyurethane backbone, and one or more terminal (meth)acrylate functional groups, the multi(meth)acrylate-functionalized oligomer being the reaction product of reactants comprising: a) at least one diisocyanate; b) at least one diol compound having at least two (meth)acrylate functional groups or at least one triol compound having at least three (meth)acrylate functional groups, or a mixture thereof; c) at least one end-capping compound having one isocyanate-reactive hydroxyl group and at least one (meth)acrylate functional group; and, optionally, d) at least one chain-extending polyol comprising at least two hydroxyl groups and from 0 to 1 (meth)acrylate functional group.

29. 30. The multi(meth)acrylate-functionalized oligomer of claim 28, wherein b) comprises at least one diol compound, and the diol compound is a reaction product of reactants consisting of an acid-functionalized (meth)acrylate and a diepoxide.

30. 30. The multi(meth)acrylate-functionalized oligomer of claim 28 or 29, wherein b) comprises at least one triol compound, and the triol compound is a reaction product of reactants consisting of an acid-functionalized (meth)acrylate and a triepoxide.

31. The acid-functionalized (meth)acrylate has the following formula (V): 【Chemistry 17】 (Wherein R is H or CH ３ and n is an integer from 0 to 5.

31. The multi(meth)acrylate-functionalized oligomer of claim 29 or 30, having a structure corresponding to:

32. 30. The multi(meth)acrylate-functionalized oligomer of claim 29, wherein the diepoxide is selected from the group consisting of diene diepoxides and diglycidyl ethers.

33. 33. The multi(meth)acrylate-functionalized oligomer of any one of claims 28, 29, 31, and 32, wherein the diol compound is 1,4-bis(3-acryloyloxy-2-hydroxypropoxy)butane.

34. 34. The multi(meth)acrylate-functionalized oligomer of any one of claims 28 to 33, wherein the end-capping compound is selected from the group consisting of (meth)acrylates of polyols in which a total of one hydroxyl group is (meth)acrylated.

35. 35. The multi(meth)acrylate-functionalized oligomer of any one of claims 28 to 34, wherein the end-capping compound is selected from the group consisting of hydroxyalkyl(meth)acrylates and caprolactone-modified hydroxyalkyl(meth)acrylates.

36. 36. The multi(meth)acrylate-functionalized oligomer of any one of claims 28 to 35, wherein the reactants comprise at least one chain-extended polyol selected from the group consisting of non-polymeric aliphatic diols having at most one (meth)acrylate functional group per molecule, polyether polyols, polyester polyols, polydiene polyols, polycarbonate polyols, and polyorganosiloxane polyols.

37. 1. A method for producing a multi(meth)acrylate-functionalized oligomer having a polyurethane backbone, a plurality of (meth)acrylate functional groups pendant to the polyurethane backbone, and one or more terminal (meth)acrylate functional groups, the method comprising the steps of reacting a) at least one diisocyanate, b) at least one diol compound having at least two (meth)acrylate functional groups or at least one triol compound having at least three (meth)acrylate functional groups, or a mixture thereof, c) at least one end-capping compound having one isocyanate-reactive hydroxyl group and at least one (meth)acrylate functional group, and optionally d) at least one chain-extending polyol comprising at least two hydroxyl groups and zero or one (meth)acrylate functional group.

38. 37. A curable composition comprising at least one multi(meth)acrylate-functionalized oligomer according to any one of claims 1 to 36 and at least one of a) a photoinitiator or b) a curable compound other than the multi(meth)acrylate-functionalized oligomer according to any one of claims 1 to 36.

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