Polymer, composition, curable resin composition, cured product, and method for producing polymer

Abstract

To provide a polymer which can be produced in a high concentration, has a low viscosity when used in a curable resin composition, and can realize the improvement of physical properties and high solidification of a cured coating film.SOLUTION: A polymer comprising a structure represented by formula (1) and having an acryloyl group, wherein the acryloyl group equivalence is 100g / eq or more and 580g / eq or less. (In the formula (1), A is a structure derived from the polyhydric alcohol (A), and B is a structure derived from the polyfunctional acrylate (B). ) SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polymer, a composition, a curable resin composition, a cured product, and a method for producing a polymer. [Background technology]

[0002] In general, Michael addition polymers are produced by addition polymerization of a nucleophile, such as a polyfunctional thiol compound or a polyfunctional amine compound, with an electrophile having a double bond substituted with an electron-withdrawing group, such as divinyl sulfone or a polyfunctional acrylate. By adjusting the charging ratio of the nucleophile to the electrophile, it is possible to synthesize a Michael addition polymer with a multibranched structure and a double bond, and it is expected to be applied to coating materials such as active energy ray-curable resins.

[0003] A multi-branched structure, also known as a hyperbranched structure, has a lower viscosity than a linear structure and is therefore known as an effective means for achieving high solids in paints (see, for example, Patent Document 1). However, the hyperbranched Michael addition polymer used as the active energy ray-curable resin in Patent Document 1 contains a thiol compound, which causes problems such as odor and corrosiveness to metals.

[0004] In recent years, methods for synthesizing Michael addition polymers that do not contain thiol compounds or amine compounds have been investigated. For example, Non-Patent Document 1 discloses a method for synthesizing a Michael addition polymer by reacting a polyhydric alcohol with a polyfunctional acrylate in the presence of a phosphorus catalyst. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-314744 [Non-patent literature]

[0006] [Non-Patent Document 1] Polym.chem,2020,11,1298-1306 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the synthesis method of Michael addition polymers described in Non-Patent Document 1, it is necessary to carry out the reaction at a low concentration using an organic solvent in order to prevent the formation of ultrahigh molecular weight substances or gels due to localized progress of the Michael addition reaction. Therefore, it is difficult to obtain a Michael addition polymer at a high concentration, and it is also difficult to achieve a high solids when used in a paint.

[0008] The present invention has been made in view of the above background, and a main object of the present invention is to provide a polymer that can be produced at a high concentration and a method for producing the same, a composition containing the polymer, a curable resin composition that uses the polymer and that has a low viscosity and can improve the physical properties of a cured coating film and achieve high solidity, and a cured product thereof. [Means for solving the problem]

[0009] As a result of intensive research aimed at solving the above-mentioned problems, the present inventors have found that a Michael addition polymer can be produced at a high concentration by using a specific catalyst. They have also found that the resulting curable resin composition containing the Michael addition polymer has a low viscosity and produces a cured coating film with good physical properties, thereby completing the present invention.

[0010] [1] A polymer containing a structure represented by the following formula (1) and having an acryloyl group equivalent of 100 g / eq or more and 580 g / eq or less: [ka] (In formula (1), A is a structure derived from the polyhydric alcohol (A), and B is a structure derived from the polyfunctional acrylate (B).) [2] The polymer according to [1], having a hydroxyl value of 8 mgKOH / g or more and 100 mgKOH / g or less. [3] The polymer according to [1] or [2], having a weight-average molecular weight of 500 or more and 20,000 or less. [4] A composition comprising the polymer according to any one of [1] to [3], wherein the content of the polymer is 60 mass % or more relative to the total mass of the composition. [5] A curable resin composition comprising the polymer according to any one of [1] to [3]. [6] The curable resin composition according to [5], which is curable with active energy rays. [7] A cured product of the curable resin composition according to [5] or [6]. [8] A method for producing a polymer, comprising subjecting a polyhydric alcohol (A) and a polyfunctional acrylate (B) to a Michael addition reaction in the presence of a catalyst (C) that does not contain phosphorus, The method for producing a polymer, wherein the polymer contains a structure represented by the following formula (1) and has an acryloyl group equivalent of 100 g / eq or more and 580 g / eq or less: [ka] (In formula (1), A is a structure derived from the polyhydric alcohol (A), and B is a structure derived from the polyfunctional acrylate (B).) [9] The method according to [8], wherein the hydroxyl value of the polymer is 8 mgKOH / g or more and 100 mgKOH / g or less.

[10] The method according to [8] or [9], wherein the catalyst is a compound containing a metal salt of an alcohol or an amine compound.

[11] The method according to any one of [8] to

[10] , wherein the total concentration of non-volatile components of the polyhydric alcohol and the polyfunctional acrylate in the reaction solution of the Michael addition reaction is 60 mass % or more. [Effects of the Invention]

[0011] According to the present invention, there are provided a polymer that can be produced at a high concentration and a method for producing the same, a composition containing the polymer, a curable resin composition using the polymer that has a low viscosity and can improve the physical properties of a cured coating film and achieve high solidity, and a cured product thereof. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, the embodiments for carrying out the present invention will be described in detail, but the present invention is not limited to the following description and can be carried out in various modified forms within the scope of the gist thereof.

[0013] The definitions of terms used in the following description are as follows: "Monomer" means a raw material compound used in polymerization. "(Meth)acrylate" means methacrylate or acrylate. The mass average molecular weight (Mw) and number average molecular weight (Mn) in the present invention are values ​​determined as relative molecular weights in terms of PMMA or polystyrene measured by gel permeation chromatography (GPC). "Acryloyl group equivalent" is the molecular weight per acryloyl group. It can be calculated by dividing the molecular weight determined from the feed ratio by the number of moles of remaining acryloyl groups determined from the feed ratio. For example, when a polyhydric alcohol with functionality r and molecular weight X is reacted with a polyfunctional acrylate with functionality s and molecular weight Y in a molar ratio of z:2z, the acryloyl group equivalent [g / eq] can be calculated using the following formula (2): (X×z+Y×2×z) / (s×2×zr×z) (2)

[0014] (polymer) The polymer of the present invention contains a structure represented by the following formula (1) and has an acryloyl group equivalent of 100 g / eq or more and 580 g / eq or less. Hereinafter, the polymer of the present invention may be referred to as "polymer (I)".

[0015] [ka]

[0016] In formula (1), A is a structure derived from the polyhydric alcohol (A), and B is a structure derived from the polyfunctional acrylate (B).

[0017] The polymer (I) is a product of a Michael addition reaction of raw materials including a polyhydric alcohol (A) and a polyfunctional acrylate (B), i.e., a Michael addition polymer, and contains structural units derived from the polyhydric alcohol (A) and structural units derived from the polyfunctional acrylate (B).

[0018] The structural unit derived from the polyhydric alcohol (A) and the structural unit derived from the polyfunctional acrylate (B) contained in the polymer (I) may be bonded directly or via a structural unit derived from a monomer other than the polyhydric alcohol (A) and the polyfunctional acrylate (B). In order to improve the toughness of the cured coating film, it is preferable that the structural unit derived from the polyhydric alcohol (A) and the structural unit derived from the polyfunctional acrylate (B) are bonded via an ether bond, and the oxygen atom of the ether bond is preferably an oxygen atom derived from the polyhydric alcohol (A).

[0019] The acryloyl group equivalent of polymer (I) is 100 g / eq or more, preferably 150 g / eq or more, and more preferably 200 g / eq or more. When the acryloyl group equivalent is equal to or greater than the lower limit, cure shrinkage of a curable resin composition containing polymer (I) can be suppressed. The acryloyl group equivalent of polymer (I) is 580 g / eq or less, preferably 550 g / eq or less, and more preferably 500 g / eq or less. When the acryloyl group equivalent is equal to or less than the upper limit, it is easy to reduce the viscosity of polymer (I), and high solidification of compositions containing polymer (I) and curable resin compositions containing polymer (I) can be achieved. The lower and upper limits of the acryloyl group equivalent can be arbitrarily combined; for example, 150 g / eq or more and 550 g / eq or less is preferred, and 200 g / eq or more and 500 g / eq or less is more preferred.

[0020] The hydroxyl value of the polymer (I) is preferably 8 mgKOH / g or more, more preferably 10 mgKOH / g or more. When the hydroxyl value of the polymer (I) is equal to or greater than the lower limit, cure shrinkage of the cured coating film obtained by curing the curable resin composition containing the polymer (I) can be suppressed. The hydroxyl value of the polymer (I) is 100 mgKOH / g or less, preferably 90 mgKOH / g or less, more preferably 80 mgKOH / g or less. When the hydroxyl value of the polymer (I) is equal to or less than the upper limit, hardness of the cured coating film obtained by curing the curable resin composition containing the polymer (I) can be sufficiently increased. The lower and upper limits of the hydroxyl value can be arbitrarily combined; for example, 8 mgKOH / g or more and 90 mgKOH / g or less are preferred, and 10 mgKOH / g or more and 80 mgKOH / g or less are more preferred.

[0021] The weight-average molecular weight (Mw) of polymer (I) is preferably 500 or more, more preferably 1000 or more, even more preferably 1500 or more, and preferably 20,000 or less, more preferably 10,000 or less, and even more preferably 8,000 or less. By setting the weight-average molecular weight within the above range, it becomes easy to reduce the viscosity of polymer (I), and high solidity can be achieved for compositions containing polymer (I) and curable resin compositions containing polymer (I). Furthermore, setting the molecular weight within the above range can impart flexibility to cured coating films. The lower and upper limits of the weight-average molecular weight can be arbitrarily combined; for example, 500 to 20,000 are preferred, 1000 to 10,000 are more preferred, and 1500 to 8,000 are even more preferred.

[0022] The viscosity of the polymer (I) of the present invention at 60°C is preferably 1 mPa·s or more, more preferably 5 mPa·s or more, and even more preferably 10 mPa·s or more. If the viscosity is above the lower limit, the polymer is less susceptible to oxygen inhibition during curing. The viscosity of the polymer of the present invention at 25°C is preferably 500,000 mPa·s or less, more preferably 400,000 mPa·s or less, and even more preferably 300,000 mPa·s or less. If the viscosity is below the upper limit, the curable resin composition containing the polymer (I) can be made highly solid. The lower and upper limits of the viscosity can be arbitrarily combined; for example, 1 mPa·s or more and 500,000 mPa·s or less are preferred, 5 mPa·s or more and 400,000 mPa·s or less are more preferred, and 10 mPa·s or more and 300,000 mPa·s or less are even more preferred.

[0023] [Polyhydric alcohol (A)] The polyhydric alcohol (A) used in the synthesis of the polymer (I) is a compound having two or more hydroxyl groups in one molecule. The structural unit derived from the polyhydric alcohol (A) contained in the polymer (I) may be one type or two or more types.

[0024] Examples of the polyhydric alcohol (A) include dihydric alcohols and trihydric or higher alcohols. Examples of dihydric alcohols include aliphatic diols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, and 1,10-decanediol, and diols having an alicyclic skeleton or a heterocyclic skeleton such as 1,4-cyclohexanedimethanol, isosorbide, and 2,2'-bis(4-hydroxycyclohexyl)propane. Preferred dihydric alcohols are 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, and 1,4-cyclohexanedimethanol, as these provide a polymer (I) with good solvent solubility.

[0025] Examples of the trihydric or higher alcohol include aliphatic triols such as trimethylolpropane and glycerin, and aliphatic alcohols such as pentaerythritol, erythritol, dipentaerythritol, etc. As the trihydric or higher alcohol, trimethylolpropane and glycerin are preferred because they can produce a polymer (I) with excellent solvent solubility.

[0026] The polyhydric alcohol (A) may be an oligomer or a polymer. The oligomeric or polymeric polyhydric alcohol (A) includes, for example, a compound having one or more bonds selected from carbonate bonds, ester bonds, ether bonds, amide bonds, and siloxane bonds and having a number average molecular weight (Mn) of 10,000 or less. Examples of the polyhydric alcohol (A) which is an oligomer or polymer include polyether polyols such as polyethylene glycol, polyester polyols, polycarbonate polyols, polyamide polyols, and silicone polyols such as carbinol-modified silicones at both ends.

[0027] [Multifunctional acrylate (B)] The polyfunctional acrylate (B) used in the synthesis of the polymer (I) is a compound having two or more acryloyl groups per molecule. The structural units derived from the polyfunctional acrylate (B) contained in the polymer (I) may be one type or two or more types. Examples of the polyfunctional acrylate (B) include a polyfunctional acrylate obtained by reacting a polyhydric alcohol with acrylic acid, and a polyfunctional acrylate obtained by reacting a compound having two or more epoxy groups in one molecule with acrylic acid.

[0028] Examples of polyfunctional acrylates obtained by reacting polyhydric alcohols with acrylic acid include diacrylate compounds, triacrylate compounds, tetraacrylate compounds, and penta- and hexaacrylate compounds. Examples of diacrylate compounds include ethylene glycol diacrylate, polyethylene glycol diacrylate, propylene glycol diacrylate, polypropylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 1,10-decanediol diacrylate, neopentyl glycol diacrylate, tetraethylene glycol diacrylate, 2-hydroxy-1,3-diacryloyloxypropane, 2,2-bis[4-(acryloyloxyethoxy)phenyl]propane, 2,2-bis[4-(acryloyloxy-polyethoxy)phenyl]propane, bis[4-(acryloyloxy-ethoxy)phenyl]methane, 2-hydroxy-1-acryloyloxy-3-acryloyloxypropane, tricyclo(5.2.1.02,6)decane dimethanol diacrylate, and 1,4-cyclohexane dimethanol diacrylate.

[0029] Examples of the triacrylate compound include trimethylolpropane triacrylate, ethylene oxide-modified trimethylolpropane triacrylate, propylene oxide-modified trimethylolpropane triacrylate, glycerin triacrylate, ethylene oxide-modified glycerin triacrylate, tris-(2-acryloxyethyl)isocyanurate, and caprolactone-modified isocyanurate triacrylate. Examples of the tetraacrylate compound include pentaerythritol triacrylate, ethoxylated pentaerythritol tetraacrylate, dimethylolpropane tetraacrylate, and diglycerin ethoxylated acrylate. An example of the penta-hexaacrylate compound is dipentaerythritol penta-hexaacrylate.

[0030] Examples of polyfunctional acrylates obtained by reacting a compound having two or more epoxy groups in one molecule with acrylic acid include bisphenol A diglycidyl ether (meth)acrylic acid adduct and bisphenol F diglycidyl ether (meth)acrylic acid adduct.

[0031] The polyfunctional acrylate (B) may be an oligomer or a polymer. The polyfunctional acrylate (B) that is an oligomer or a polymer includes, for example, a compound having one or more bonds selected from a carbonate bond, an ester bond, an ether bond, an amide bond, and a siloxane bond and having a number average molecular weight (Mn) of 10,000 or less. Examples of oligomers having two or more acryloyl groups in one molecule include urethane acrylates obtained by reacting a polyhydric alcohol, a polyfunctional isocyanate, and a hydroxy group-containing acrylic acid ester, polyester acrylates obtained by reacting a polyhydric alcohol with acrylic acid, and polyether acrylates obtained by reacting polyethylene glycol, polypropylene glycol, or the like with acrylic acid.

[0032] (Polymer manufacturing method) The method for producing a polymer of the present invention is a method for obtaining a polymer (I) by Michael addition polymerization of a polyhydric alcohol (A) and a polyfunctional acrylate (B) in the presence of a catalyst (C) that does not contain phosphorus.

[0033] The catalyst (C) may be a basic catalyst that does not contain phosphorus, and examples thereof include compounds containing metal salts of alcohols, and amine compounds. The base catalyst (C) preferably has a conjugate acid whose acid dissociation constant (hereinafter referred to as "PKa") in water is 16.0 or more and less than 20.0. A base whose conjugate acid has a PKa within this range has enough basicity to abstract hydroxyl group protons from the polyhydric alcohol (A) while also being able to control the reaction rate. Therefore, the target reaction can be selectively carried out without causing unintended side reactions such as anionic polymerization.

[0034] Examples of compounds containing metal salts of alcohols include alkoxide salts such as potassium t-butoxide, sodium t-butoxide, sodium methoxide, potassium methoxide, sodium ethoxide, and potassium ethoxide. Examples of amine compounds include diguanidine compounds such as 1,2-diisopropyl-4,4,5,5-tetramethylbiguanide, 1,2-dicyclohexyl-4,4,5,5-tetramethylbiguanide, and heptamethylbiguanide, and metal amides such as potassium hexamethyldisilamide and lithium isodipropylamide. As the catalyst (C), one type may be used alone, or two or more types may be used in combination.

[0035] When the molar ratio of the polyhydric alcohol (A) to the catalyst (C) used in the Michael addition reaction is 1:x, the value of x is preferably 0.01 or more, more preferably 0.02 or more, and preferably 0.5 or less, more preferably 0.3 or less. The lower and upper limits of the value of x can be arbitrarily combined, and for example, 0.01 or more and 0.5 or less are preferred, and 0.02 or more and 0.3 or less are more preferred.

[0036] An organic solvent may be used in the Michael addition reaction. Examples of organic solvents include aromatic hydrocarbon solvents such as toluene, ethylbenzene, xylene, and mesitylene; aliphatic hydrocarbon solvents such as pentane, hexane, heptane, octane, and cyclohexane; ketone solvents such as acetone, cyclohexanone, methyl isobutyl ketone, and methyl ethyl ketone; ester solvents such as butyl acetate and ethyl acetate; ether solvents such as tetrahydrofuran and dioxane; amide solvents such as N,N-dimethylformamide; and sulfoxide solvents such as dimethyl sulfoxide.

[0037] The total nonvolatile component concentration of the polyhydric alcohol (A) and the polyfunctional acrylate (B) in the reaction solution of the Michael addition reaction is preferably 60% by mass or more, more preferably 65% ​​by mass or more, and even more preferably 70% by mass or more. When the nonvolatile component concentration is equal to or greater than the lower limit, it is easy to achieve high solidity in the composition containing the polymer (I) and the curable resin composition containing the polymer (I). The Michael addition reaction can also be carried out without a solvent.

[0038] The reaction temperature for the Michael addition reaction is not particularly limited, but is preferably, for example, 0°C or higher and 150°C or lower. When the Michael addition reaction is carried out without a solvent, it is preferable to carry out the reaction at a temperature equal to or higher than the melting point of the polyhydric alcohol (A). By setting the reaction temperature at or higher than the melting point of the polyhydric alcohol (A), the polyhydric alcohol (A) dissolves and mixes more intimately with the polyfunctional acrylate (B), which is expected to improve the reaction rate. The reaction time for the Michael addition reaction is not particularly limited, but can be, for example, from 0.5 hours to 48 hours.

[0039] (composition) The composition of the present invention contains polymer (I), and the content of polymer (I) is 60 mass % or more based on the total mass of the composition. The composition of the present invention can be obtained, for example, by diluting the polymer (I) with at least one selected from the group consisting of an organic solvent and a monomer having a radically polymerizable functional group. The composition of the present invention can be used as a raw material for a curable resin composition.

[0040] The content of polymer (I) in the composition of the present invention is 60% by mass or more, preferably 65% ​​by mass or more, and more preferably 70% by mass or more, based on the total mass of the composition. When the content of polymer (I) is equal to or greater than the lower limit, the degree of freedom in formulation design of the curable resin composition is increased, and high solidification can be achieved. Furthermore, the content of polymer (I) in the composition of the present invention may be 100% by mass.

[0041] [Organic solvents] The organic solvent used in the composition of the present invention is selected in consideration of the solubility of the polymer (I), viscosity adjusting effect, combination with the organic solvent used in the curable resin composition, adjustment of the volatilization and drying speed when applying the curable resin composition, etc.

[0042] Examples of organic solvents include ethyl acetate, butyl acetate, hexane, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, toluene, xylene, mesitylene, propylene glycol monomethyl ether, 1-methoxy-2-propanol, methanol, ethanol, 1-propanol, 2-propanol, tetrahydrofuran, diethyl ether, dimethylformamide, dimethyl sulfoxide, and dimethylacetamide. From the viewpoints of solubility and volatility, preferred organic solvents are ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, toluene, propylene glycol monomethyl ether, 1-methoxy-2-propanol, 1-propanol, and 2-propanol. The organic solvent used in the composition of the present invention may be one type or two or more types.

[0043] [Monomer] The radically polymerizable functional group contained in the monomer used in the composition of the present invention is preferably a (meth)acryloyl group or an allyl group. Examples of the monomer having a (meth)acryloyl group include mono(meth)acrylates having an alkyl group, difunctional (meth)acrylates, trifunctional (meth)acrylates, and tetrafunctional or higher (meth)acrylates. The monomer contained in the composition of the present invention may be one type or two or more types.

[0044] Examples of mono(meth)acrylates having an alkyl group include methyl(meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, butyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, and octyl(meth)acrylate.

[0045] Examples of bifunctional (meth)acrylates include (poly)ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, pentaerythritol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 2-hydroxy-3-acryloyloxypropyl methacrylate, dimethyloltricyclodecane di(meth)acrylate, and dicyclopentanyl di(meth)acrylate.

[0046] Examples of trifunctional (meth)acrylates include triacrylates such as trimethylolpropane tri(meth)acrylate, ethylene oxide-modified trimethylolpropane tri(meth)acrylate, propylene oxide-modified trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, alkyl-modified dipentaerythritol tri(meth)acrylate, tris(2-acryloxyethyl)isocyanurate, and ε-caprolactone-modified tris(2-acryloxyethyl)isocyanurate, glycerin tri(meth)acrylate, ethylene oxide-modified glycerin tritri(meth)acrylate, and propylene oxide-modified triglycerin (meth)acrylate.

[0047] Examples of tetrafunctional (meth)acrylates include ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, alkyl-modified dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, alkyl-modified dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and caprolactone-modified dipentaerythritol hexa(meth)acrylate.

[0048] (Curable resin composition) The curable resin composition of the present invention contains a polymer (I). The curable resin composition of the present invention is preferably an active energy ray-curable resin composition, that is, the curable resin composition of the present invention preferably contains the polymer (I) and a photopolymerization initiator as essential components, and further contains other components as necessary.

[0049] The content of polymer (I) in the curable resin composition of the present invention is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, based on the total mass of the curable resin composition. When the content of polymer (I) is equal to or greater than the above-mentioned lower limit, it becomes easier to reduce warping of the cured coating film, and the toughness of the cured coating film becomes good. The content of polymer (I) in the curable resin composition of the present invention is preferably 99% by mass or less, more preferably 95% by mass or less, and even more preferably 90% by mass or less, based on the total mass of the curable resin composition. When the content of polymer (I) is equal to or less than the above-mentioned upper limit, it is easy to reduce the viscosity of the curable resin composition.

[0050] [Photopolymerization initiator] The photopolymerization initiator is a compound that is cleaved by irradiation with active energy rays to generate active species such as radicals that initiate a polymerization reaction. As the active energy rays, ultraviolet rays are preferred from the viewpoints of equipment cost and productivity. Examples of photopolymerization initiators that generate radicals when exposed to ultraviolet light include Omnirad127, Omnirad184, Omnirad369, Omnirad500, Omnirad754, Omnirad819, Omnirad907, Omnirad1173, Omnirad2959, Omnirad TPO, and Omnirad MBF (trade names, all manufactured by iGM RESINS), Irgacure OXE01, Irgacure OXE02, and Irgacure OXE04 (trade names, all manufactured by BASF Japan), DAIDO UV-CURE PMB, DAIDO UV-CURE OMB, DAIDO UV-CURE BMS, DAIDO UV-CURE 171, DAIDO UV-CURE D-177F, DAIDO UV-CURE #174, and PHOTOCURE 550 (trade name, all manufactured by Daido Chemical Industry Co., Ltd.). The photopolymerization initiator used in the curable resin composition of the present invention may be one type or two or more types.

[0051] The content of the photopolymerization initiator contained in the active energy ray-curable resin composition is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and even more preferably 1 part by mass or more, per 100 parts by mass of the total polymerizable components. When the content of the photopolymerization initiator is at least the above-mentioned lower limit, it is easy to ensure a sufficient curing rate when curing the active energy ray-curable resin composition. When the content of the photopolymerization initiator is at least the above-mentioned upper limit, it is possible to prevent a decrease in hardness due to plasticization of the cured film obtained by curing the active energy ray-curable resin composition. The lower and upper limits of the content of the photopolymerization initiator can be arbitrarily combined, and for example, 0.01 to 20 parts by mass is preferred, 0.1 to 15 parts by mass is more preferred, and 1 to 10 parts by mass is even more preferred.

[0052] (Other ingredients) The curable resin composition of the present invention may contain other components in addition to the polymer (I) and the photopolymerization initiator. Examples of other components include compounds having a polymerizable functional group, organic solvents, inorganic fillers, nanofillers, cellulose nanofibers, carbon nanotubes, colloidal silica, antioxidants, ultraviolet absorbers, infrared absorbers, colorants, dyes, pigments, flame retardants, surface conditioners, and leveling agents. The number of other components used in the curable resin composition of the present invention may be one or two or more.

[0053] The compound having a polymerizable functional group is preferably a monomer having a (meth)acryloyl group or an oligomer having a (meth)acryloyl group. Examples of monomers having a (meth)acryloyl group include mono(meth)acrylate compounds having an alkyl group, difunctional (meth)acrylates, trifunctional (meth)acrylates, and tetrafunctional or higher (meth)acrylates.

[0054] Examples of mono(meth)acrylates having an alkyl group include methyl(meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, butyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, and octyl(meth)acrylate.

[0055] Examples of bifunctional (meth)acrylates include (poly)ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 4,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, pentaerythritol di(meth)acrylate, neopentyl glycol dimethacrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 2-hydroxy-3-acryloyloxypropyl methacrylate, dimethyloltricyclodecane di(meth)acrylate, and dicyclopentanyl di(meth)acrylate.

[0056] Examples of trifunctional (meth)acrylates include triacrylates such as trimethylolpropane tri(meth)acrylate, ethylene oxide-modified trimethylolpropane tri(meth)acrylate, propylene oxide-modified trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, alkyl-modified dipentaerythritol tri(meth)acrylate, tris(2-acryloxyethyl)isocyanurate, and ε-caprolactone-modified tris(2-acryloxyethyl)isocyanurate, glycerin tri(meth)acrylate, ethylene oxide-modified glycerin tritri(meth)acrylate, and propylene oxide-modified triglycerin (meth)acrylate.

[0057] Examples of tetrafunctional or higher (meth)acrylates include ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, alkyl-modified dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, alkyl-modified dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and caprolactone-modified dipentaerythritol hexa(meth)acrylate.

[0058] Examples of oligomers having a (meth)acryloyl group include urethane acrylates obtained by reacting a polyhydric alcohol, a polyfunctional isocyanate, and a hydroxy group-containing acrylic acid ester, polyester acrylates obtained by reacting a polyhydric alcohol with acrylic acid, and polyether acrylates obtained by reacting polyethylene glycol, polypropylene glycol, or the like with acrylic acid.

[0059] Examples of organic solvents include ethyl acetate, butyl acetate, hexane, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, toluene, xylene, mesitylene, propylene glycol monomethyl ether, 1-methoxy-2-propanol, methanol, ethanol, 1-propanol, 2-propanol, tetrahydrofuran, diethyl ether, dimethylformamide, dimethyl sulfoxide, and dimethylacetamide. From the viewpoints of solubility and volatility, preferred organic solvents are ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, toluene, propylene glycol monomethyl ether, 1-methoxy-2-propanol, 1-propanol, and 2-propanol.

[0060] (cured product) The cured product of the present invention is a cured product of the curable resin composition of the present invention. The cured product of the present invention is preferably a cured product obtained by using an active energy ray-curable resin composition as the curable resin composition of the present invention and curing it by irradiating it with active energy rays.

[0061] The cured product of the present invention can be produced by applying the curable resin composition of the present invention to the surface of a substrate, followed by irradiating with active energy rays to form a cured coating film. Examples of methods for applying the curable resin composition include roller coating, spray coating, dip coating, spin coating, gravure coating, offset printing, flexographic printing, and bar coating.

[0062] Examples of active energy ray irradiators used to form a cured coating film include high-pressure mercury lamps, xenon lamps, metal halide lamps, and ultraviolet light-emitting diodes. The irradiation dose (cumulative light dose) of active energy rays is 100 mJ / cm 2 More than 150 mJ / cm is preferable. 2 More preferably, 200 mJ / cm or more 2 More preferably, 5000 mJ / cm 2 Preferably less than 4000mJ / cm 2 Less than 3000mJ / cm is more preferable. 2 The lower limit and upper limit of the irradiation amount of the active energy ray can be arbitrarily combined, and for example, 100 mJ / cm 2 More than 5000mJ / cm 2 Less than 150 mJ / cm is preferred 2 More than 4000mJ / cm 2 Less than 200 mJ / cm is more preferable. 2 More than 3000mJ / cm 2 The following is even more preferred:

[0063] The curing temperature is preferably 0° C. or higher, more preferably 10° C. or higher, and is preferably 150° C. or lower, more preferably 100° C. or lower. The upper and lower limits of the curing temperature can be arbitrarily combined, and for example, the temperature is preferably 0° C. or higher and 150° C. or lower, more preferably 10° C. or higher and 100° C. or lower.

[0064] The humidity during curing is, for example, preferably 10% or more, more preferably 15% or more, and preferably 80% or less, more preferably 70% or less. The lower and upper limits of the humidity during curing can be arbitrarily combined, and for example, is preferably 10% or more and 80% or less, more preferably 15% or more and 70% or less.

[0065] As explained above, the viscosity of the polymer (I) of the present invention can be reduced by adjusting the acryloyl group equivalent weight within a specified range. Therefore, compositions containing the polymer (I) and curable resin compositions containing the polymer (I) can be made more concentrated than before, and high solidity coatings can be achieved. Furthermore, by using the polymer (I) as an active energy ray-curable resin, the physical properties of the cured coating film can be improved. Furthermore, the composition containing the polymer (I) and the curable resin composition containing the polymer (I) have a high concentration and a low viscosity, and can achieve high solidity in the coating material. [Example]

[0066] The polymer according to the present invention, the composition containing the polymer, the curable resin composition containing the polymer, and the cured product of the curable resin composition will be described in more detail below with reference to examples. Note that the specific aspects of the polymer according to the present invention, the composition containing the polymer, the curable resin composition containing the polymer, and the curable resin composition are not limited to those in the examples, and various modifications are possible without departing from the gist of the present invention.

[0067] (raw materials) The raw materials used in the examples and comparative examples are shown below. [Polyhydric alcohol (A)] PDO: 1,3-propanediol (Tokyo Chemical Industry Co., Ltd.) TMP: Trimethylolpropane (Tokyo Chemical Industry Co., Ltd.)

[0068] [Multifunctional acrylate (B)] Aronix M930: Glycerin triacrylate (manufactured by Toagosei Co., Ltd.) C6DA: 1,6-hexanediol diacrylate (Tokyo Chemical Industry Co., Ltd.) Aronix M309: Trimethylolpropane triacrylate (manufactured by Toagosei Co., Ltd.)

[0069] [Catalyst (C)] t-BuOK: Potassium t-butoxide (Tokyo Chemical Industry Co., Ltd.) DITMB: 1,2-diisopropyl-4,4,5,5-tetramethylbiguanide (prepared in Preparation Example 1 below)

[0070] [Catalyst (X)] P2-tBu: 1-tert-butyl-2,2,4,4,4-pentakis(dimethylamino)-2λ 5 ,4λ 5 -Catenadi(phosphazene) (Sigma-Aldrich Co., Ltd.)

[0071] [solvent] Butyl acetate (Fujifilm Wako Pure Chemical Industries, Ltd.)

[0072] [Photopolymerization initiator] Omnirad184: 1-hydroxycyclohexyl phenyl ketone (IGM Resins)

[0073] (Measurement and evaluation methods) The measurement and evaluation methods are shown below. [Relative weight average molecular weight] The relative weight-average molecular weight Mw of the polymer was measured by gel permeation chromatography (GPC). Specifically, approximately 10 mg of polymer was dissolved in 10 mL of tetrahydrofuran to prepare a sample solution with a concentration of approximately 1 mg / mL. The sample solution was filtered using a membrane filter with a pore size of 0.1 μm, and then measurement was performed using a measuring device equipped with a column consisting of a TSK GUARD COLUMN SUPER HH (4.6 × 35 mm, manufactured by Tosoh Corporation) and two TSK-GEL SUPER HM-H (6.0 × 150 mm, manufactured by Tosoh Corporation) connected in series. Detailed measurement conditions are as follows. Measuring device: HLC-8220 (Tosoh Corporation) Detector: Refractive index (RI) detector Column and detector temperature: 40°C Eluent: tetrahydrofuran Flow rate: 0.6mL / min Standard material: polymethyl methacrylate (Polymer Laboratories; Mp (peak molecular weight) = 141,500, 55,600, 11,100, 1,590)

[0074] [Hydroxyl value] The hydroxyl value of the polymer was measured by FT-IR spectroscopy. Specifically, the polymer was first dissolved in tetrahydrofuran to prepare a sample solution with a concentration of 1.00 g / mL. The sample solution was introduced into a 10 mm glass measurement cell, and measurement was carried out using the following measurement equipment. -1 The minimum value around 6500 cm is used as the baseline, and the absorbance at each wavenumber when that point is set as the zero point is used as the peak intensity. -1 From 6600cm -1 The sum of the peak intensities from On the other hand, 1,3-propanediol, the alcohol raw material, was dissolved in tetrahydrofuran to prepare calibration solutions with various hydroxyl group concentrations (mol / L). A calibration curve was created from the peak areas obtained by the measurements, and the hydroxyl value was calculated from the hydroxyl group concentration of the polymer obtained from the calibration curve using the following formula. Hydroxyl value = hydroxyl concentration (mol / L) ÷ 1.00 (g / mL) × 56.1 (g / mol) Measurement equipment: FT-IR6200FV (JASCO Corporation) Detector: InGaAs (near infrared) detector Light source: Halogen lamp Beam splitter: Si / CaF2 Window board: KRS-5+CaF2 Measurement room: room temperature Measurement cell: 10mm glass cell G-104

[0075] [viscosity] The viscosity of the polymer was measured using an E-type viscometer. Specifically, 1 mL of the polymer was added to a sample cup, and the viscosity was measured. The detailed measurement conditions were as follows: Measurement equipment: Brookfield E-type viscometer Measurement temperature: 60℃

[0076] [Scratch resistance] 750gf (4cm area) of steel wool #0000 2 The surface of the cured coating film formed on the ABS resin substrate was rubbed 10 times at a speed of 28 cm / s using a Gakushin abrasion tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.), and the difference in haze before and after the test was measured and evaluated according to the following criteria. Haze was measured using a haze meter ("NDH8000" manufactured by Nippon Denshoku Industries Co., Ltd.). <Evaluation criteria> 1: The difference in haze before and after the test is less than 0.5. 2: The difference in haze before and after the test is 0.5 or more and less than 0.7. 3: The difference in haze before and after the test is 0.7 or more.

[0077] [Pencil hardness] The pencil hardness of the cured coating film formed on the ABS resin substrate was measured in accordance with JIS K5600-5-4:1999 General testing methods for paints - Part 5: Mechanical properties of coating films - Section 4: Scratch hardness (pencil method).

[0078] [Hot stampability (decoration)] (1) Ease of foil attachment A foil (FINEFOIL TA-5 Gold) was pressed onto the surface of a cured coating film formed on an ABS resin substrate at 160°C for 0.5 seconds using a tabletop foil stamping machine. Cellophane tape was then applied over the decorated foil on the substrate and peeled off, and the area of ​​the foil remaining on the coating surface was visually observed and evaluated according to the following criteria. <Evaluation criteria> 1: The remaining foil area is 90% or more and 100% or less. 2: The remaining foil area is 60% or more but less than 90%. 3: The area of ​​remaining foil is 0% or more and less than 60%.

[0079] Warp height The curable resin composition was applied to a 50 μm thick PET film (DIAFOIL T600E50, manufactured by Mitsubishi Chemical Corporation) using a bar coater so that the film thickness after curing would be 10 μm. The cured laminate was cut into a 10 cm × 10 cm rectangle to prepare a sample. The obtained sample was placed on a flat surface, and a load of 125 g / cm was applied to the center of the sample. 2 The heights of the four corners were measured, and the total value was taken as the warpage height.

[0080] (Synthesis of catalyst (C)) [Manufacturing Example 1] 20.0 g of tetramethylguanidine and 26.3 g of N,N'-diisopropylcarbodiimide were weighed into a 200 mL three-neck flask and equipped with a condenser, thermocouple, and nitrogen inlet. The flask was then heated to 110°C and reacted for 3 hours. The reaction mixture was concentrated using an evaporator, and the resulting crystals were washed with hexane and concentrated again using an evaporator to synthesize 1,2-diisopropyl-4,4,5,5-tetramethylbiguanide (DITMB).

[0081] (Polymer synthesis) [Example 1] 3.00 g of PDO and 0.22 g of t-BuOK were weighed into a 50 mL sample bottle. The sample bottle was then heated to 80°C and stirred for 15 minutes to obtain a homogeneous solution. 10.0 g of Aronix M930 was then added and reacted for 1 hour to obtain a polymer.

[0082] [Example 2] 10.0 g of PDO and 0.736 g of t-BuOK were weighed into a 200 mL flask. The flask was then heated to 80°C and stirred for 15 minutes to obtain a homogeneous solution. 50.1 g of Aronix M930 and 15.0 g of butyl acetate were then mixed to obtain an Aronix M930 solution. The prepared Aronix M930 solution was then added to the flask and reacted for 3 hours to obtain a polymer.

[0083] [Example 3] 20.0 g of PDO and 6.40 g of DITMB obtained in Production Example 1 were weighed into a 200 mL flask, and the flask was heated to 80°C and stirred for 15 minutes to obtain a homogeneous solution. Next, 95.5 g of Aronix M930 was added to the flask, and the mixture was reacted for 3 hours to obtain a polymer.

[0084] [Comparative Example 1] 10.0 g of TMP was weighed into a 100 mL flask and dissolved by heating to 80°C. Next, 3.72 mL of a THF solution of P2-tBu (concentration 2.0 M) was added and stirred for 15 minutes. Next, 33.7 g of C6DA was added, causing the reaction solution to gel.

[0085] Comparative Example 2 A reaction was carried out in the same manner as in Comparative Example 1 except that the amount of P2-tBu THF solution (concentration: 2.0 M) added was changed to 1.86 mL. As a result, the reaction solution gelled in the same manner as in Comparative Example 1.

[0086] The charge composition and evaluation results of the polymers produced in each example are shown in Table 1. In the charge composition, the charge ratio of each component is shown in molar equivalents based on the polyhydric alcohol (A).

[0087] [Table 1]

[0088] As shown in Table 1, in Examples 1 to 3, in which a catalyst (C) not containing phosphorus element was used, polymers could be synthesized even at high concentrations. Furthermore, the polymers obtained in Examples 1 to 3 had low viscosity, and by using them in a curable resin composition, a curable resin composition with low viscosity could be obtained. On the other hand, in Comparative Examples 1 and 2, in which a phosphorus catalyst was used, the reaction could not be controlled and gelation occurred.

[0089] (Preparation of cured coating film) [Example 4] 1.0 g of the polymer obtained in Example 1 and 0.03 g of Omnirad184 were weighed into a sample bottle and dissolved in 1.0 g of butyl acetate to prepare a curable resin composition. Next, the curable resin composition was applied to each substrate using a bar coater, dried in a hot air dryer at 60°C for 3 minutes, and then applied to a high-pressure mercury lamp at an illuminance of 70 mW / cm and an irradiation dose of 800 mJ / cm. 2 The coating was cured by irradiating with ultraviolet light under the conditions of: The thickness of the resulting cured coating was 20 μm.

[0090] [Example 5] 1.0 g of the polymer obtained in Example 1, 1.0 g of Aronix M309 (trimethylolpropane triacrylate), and 0.06 g of Omnirad 184 were weighed into a sample bottle and dissolved in 2.0 g of butyl acetate to prepare a curable resin composition. Next, the curable resin composition was applied to each substrate using a bar coater, dried in a hot air dryer at 60°C for 3 minutes, and then applied to a high-pressure mercury lamp at an illuminance of 70 mW / cm and an irradiation dose of 800 mJ / cm. 2 The coating was cured by irradiating with ultraviolet light under the conditions of: The thickness of the resulting cured coating was 20 μm.

[0091] Comparative Example 3 1.0 g of trimethylolpropane triacrylate and 0.03 g of Omnirad 184 were weighed into a sample bottle and dissolved in 1.0 g of butyl acetate to prepare a curable resin composition. Next, the curable resin composition was applied to an ABS resin substrate using a bar coater, dried in a hot air dryer at 60°C for 3 minutes, and then applied to a high-pressure mercury lamp at an illuminance of 70 mW / cm and an irradiation dose of 800 mJ / cm. 2 The coating was cured by irradiating with ultraviolet light under the conditions of: The thickness of the resulting cured coating was 20 μm.

[0092] Comparative Example 4 1.0 g of Aronix M930 and 0.03 g of Omnirad 184 were weighed into a sample bottle and dissolved in 1.0 g of butyl acetate to prepare a curable resin composition. Next, the curable resin composition was applied to an ABS resin substrate using a bar coater, dried in a hot air dryer at 60°C for 3 minutes, and then applied to a high-pressure mercury lamp at an illuminance of 70 mW / cm and an irradiation dose of 800 mJ / cm. 2 The coating was cured by irradiating with ultraviolet light under the conditions of: The thickness of the resulting cured coating was 20 μm.

[0093] The evaluation results of the cured coating film are shown in Table 2.

[0094] [Table 2]

[0095] As shown in Table 2, the cured coating films of Examples 4 and 5 had high hardness, excellent hot stampability, and suppressed warpage. On the other hand, the cured coating film of Comparative Example 3 had high hardness but poor hot stampability and large warpage. Furthermore, in Comparative Example 4, in which Aronix M930, the raw material for the polymer of Example 1, was cured alone, the curability was insufficient and tack remained in the cured coating film.

[0096] As described above, it has been found that the present invention makes it possible to carry out a Michael addition reaction between a polyhydric alcohol and a polyfunctional acrylate under high concentration conditions, and that when the polymer of the present invention is used as an active energy ray-curable resin, due to its characteristic structure, a cured coating film having high hardness, excellent flexibility, and little warping can be obtained. Based on these properties, it is expected that the polymer will be applied to various active energy ray-curable materials.

Claims

1. A polymer comprising a structure represented by the following formula (1), having an acryloyl group equivalent of 100 g / eq or more and 580 g / eq or less: 【Chemistry 1】 (In formula (1), A is a structure derived from the polyhydric alcohol (A), and B is a structure derived from the polyfunctional acrylate (B).)

2. The polymer according to claim 1, having a hydroxyl value of 8 mgKOH / g or more and 100 mgKOH / g or less.

3. The polymer according to claim 1, having a weight average molecular weight of 500 or more and 20,000 or less.

4. A composition comprising the polymer according to any one of claims 1 to 3, wherein the content of the polymer is 60 mass% or more relative to the total mass of the composition.

5. A curable resin composition comprising the polymer of claim 1.

6. The curable resin composition according to claim 5, which is curable with active energy rays.

7. A cured product of the curable resin composition according to claim 5 or 6.

8. A method for producing a polymer, comprising subjecting a polyhydric alcohol (A) and a polyfunctional acrylate (B) to a Michael addition reaction in the presence of a catalyst (C) that does not contain phosphorus, The method for producing a polymer, wherein the polymer contains a structure represented by the following formula (1) and has an acryloyl group equivalent of 100 g / eq or more and 580 g / eq or less: 【Chemistry 2】 (In formula (1), A is a structure derived from the polyhydric alcohol (A), and B is a structure derived from the polyfunctional acrylate (B).)

9. The method according to claim 8, wherein the polymer has a hydroxyl value of 8 mgKOH / g or more and 100 mgKOH / g or less.

10. The method according to claim 8, wherein the catalyst is a compound containing a metal salt of an alcohol or an amine compound.

11. The method according to claim 8 , wherein a total concentration of nonvolatile components of the polyhydric alcohol and the polyfunctional acrylate in the reaction solution of the Michael addition reaction is 60% by mass or more.

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