Copolymer, resin composition, cured product, and polymer mixture

Abstract

Disclosed are: a copolymer which contains a constituent unit (a) that has a monovalent group represented by formula (1) and a constituent unit (b) that has a monovalent group represented by formula (2); a polymer mixture which includes a polymer A that contains a constituent unit (a) that has a monovalent group represented by formula (1) and a polymer B that contains a constituent unit (b) that has a monovalent group represented by formula (2); and a resin composition which contains the copolymer, and a cured product of the resin composition. The details of the substituents in formula (1) and formula (2) are shown in the text of the description.

Description

Copolymers, resin compositions, cured products, and polymer mixtures

[0001] The present invention relates to a copolymer, a resin composition, a cured product, and a polymer mixture.

[0002] Known examples of crosslinking systems utilizing isocyanates include the formation of urethane bonds using isocyanate-blocked compounds and the formation of ester bonds using transesterified blocks. Blocked isocyanate compounds are compounds in which the isocyanato group of a compound having an isocyanato group is reacted with a blocking agent to inactivate (block) the reactivity of the isocyanato group. For example, when using a blocked isocyanate compound as a curing agent, blocking the isocyanato group makes it possible to premix the active hydrogen group-containing base compound and the blocked isocyanate compound into a single liquid, eliminating the need to separately prepare a first liquid containing a base compound having an active hydrogen group and a second liquid containing a compound having an isocyanato group for reaction with the active hydrogen group. For this reason, blocked isocyanate compounds are widely used in adhesives, coatings, molding materials, resins, and the like.

[0003] The formation of crosslinks during resin production is an important means for improving resin properties. However, for the purpose of resin substrates and energy conservation, it is required to keep the heating temperature during crosslink formation low, for example, below 100°C. One method that can form crosslinks at low temperatures is known to be the introduction of double bonds into the (co)polymer that forms the main chain of the resin.

[0004] As compounds having a double bond that can be crosslinked at low temperatures (100°C or less) using a blocked isocyanate compound, and resins obtained by curing compounds having such double bonds, for example, Patent Document 1 discloses a specific blocked isocyanate compound and a compound having a double bond formed from the blocked isocyanate compound and a specific base. Furthermore, as a resin composition that has excellent low-temperature curing properties and can form a cured product with good solvent resistance, and a copolymer contained in this resin composition, for example, Patent Document 2 discloses a copolymer containing a structural unit having a conjugated diene moiety in a side chain and a group (R １ and R２ is a hydrocarbon group having 1 to 20 carbon atoms. ３ and R ４ is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms.) and a copolymer containing no carboxy group.

[0005]

[0006] International Publication No. 2022 / 145298 Japanese Patent Application Laid-Open No. 2023-074384

[0007] The compounds described in Patent Document 1 and the resin compositions described in Patent Document 2 are required to be further improved in terms of solvent resistance and low-temperature curing properties. An object of one embodiment of the present invention is to provide a copolymer that can give a cured product having excellent solvent resistance, a polymer mixture, and a resin composition containing this copolymer. Another object of one embodiment of the present invention is to provide a cured product having good solvent resistance.

[0008] Means for solving the above problems include the following aspects: <1> A copolymer containing a structural unit (a) having a monovalent group represented by the following formula (1), and a structural unit (b) having a monovalent group represented by the following formula (2).

[0009] (In formula (1), R １ and R ２ are each independently a hydrocarbon group having 1 to 20 carbon atoms, and R ３ and R ４ are each independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and * represents a link to another binding site.

[0010]

[0011] (In formula (2), R ５ is a hydrocarbon group having 1 to 20 carbon atoms, and R ６ represents a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a group represented by the following formula (3), A represents -NH- or -O-, and * represents a linking point to another bonding site.

[0012]

[0013] (In formula (3), R ７ is a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a group represented by a combination of one or more hydrocarbon groups having 1 to 20 carbon atoms and one or more oxygen atoms, and * is R ６ <2> The copolymer according to <1>, having the structural unit (a) and the structural unit (b) in a side chain. <3> R in formula (3) represents a bonding site with the carbon atom to which R is bonded. ７ is OR ８ A group represented by the above R ８ <4> The copolymer according to any one of <1> to <3>, wherein the structural unit (b) is a structural unit derived from a monomer (m-b) represented by the following formula (4):

[0014]

[0015] (In formula (4), R ８ represents a hydrogen atom or a methyl group, and R ９ represents a linear or branched divalent aliphatic saturated hydrocarbon group having 1 to 20 carbon atoms which may have an internal ether bond, or an aromatic hydrocarbon group, or a divalent alicyclic hydrocarbon group having 6 to 20 carbon atoms which may have an internal urethane bond; R １０ and R １１ are each independently a hydrocarbon group having 1 to 20 carbon atoms. １ and R ２ are each independently a hydrocarbon group having 1 to 3 carbon atoms, and R ３ and R ４are each independently a hydrogen atom or a methyl group. <6> The copolymer according to any one of <1> to <5>, wherein the proportion of the number of structural units (a) relative to the total number of monomer units in the copolymer is 1 to 99 mol %, and the proportion of the number of structural units (b) relative to the total number of monomer units in the copolymer is 1 to 99 mol %. <7> The copolymer according to any one of <1> to <6>, further comprising other structural units (c), wherein the other structural units (c) include a structural unit derived from an alkyl(meth)acrylate. <8> The copolymer according to any one of <1> to <6>, further comprising another structural unit (c), wherein the other structural unit (c) comprises a structural unit derived from an alkyl(meth)acrylate, wherein the proportion of the number of structural units (a) relative to the total number of monomer units of the copolymer is 1 to 50 mol%, the proportion of the number of structural units (b) relative to the total number of monomer units of the copolymer is 1 to 50 mol%, and the proportion of the number of structural units (c) relative to the total number of monomer units of the copolymer is 40 to 98 mol%. <9> The copolymer according to any one of <1> to <8>, wherein A in formula (2) is —NH—. <10> A resin composition comprising the copolymer according to any one of <1> to <9>, a basic catalyst (B), and a solvent (C). <11> The resin composition according to <10>, wherein the basic catalyst (B) comprises at least one selected from the group consisting of 1,8-diazabicyclo[5.4.0]-7-undecene or a salt thereof, 1,5-diazabicyclo[4.3.0]-5-nonene or a salt thereof, 1,5,7-triazabicyclo[4.4.0]dec-5-ene or a salt thereof, and triethylmethylammonium 2-ethylhexane salt. <12> A cured product obtained by curing the resin composition according to <10> or <11>. <13> A polymer mixture comprising: a polymer A comprising a structural unit (a) having a monovalent group represented by formula (1) below; and a polymer B comprising a structural unit (b) having a monovalent group represented by formula (2) below:

[0016]

[0017] (In formula (1), R １and R ２ are each independently a hydrocarbon group having 1 to 20 carbon atoms, and R ３ and R ４ are each independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and * represents a link to another binding site.

[0018]

[0019] (In formula (2), R ５ is a hydrocarbon group having 1 to 20 carbon atoms, and R ６ represents a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a group represented by the following formula (3), A represents -NH- or -O-, and * represents a linking point to another bonding site.

[0020]

[0021] (In formula (3), R ７ is a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a group represented by a combination of one or more hydrocarbon groups having 1 to 20 carbon atoms and one or more oxygen atoms, and * is R ６ represents the bonding site with the carbon atom to which it is bonded.)

[0022] <14> The polymer mixture according to <13>, wherein A in the formula (2) is —NH—. <15> A cured product comprising a resin having a structural unit represented by the following formula (n):

[0023]

[0024] (In formula (n), R ２ are each independently a hydrocarbon group having 1 to 20 carbon atoms, and R ５ is a hydrocarbon group having 1 to 20 carbon atoms, and R ６ represents a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a group represented by the following formula (3), A represents -NH- or -O-, and * represents a linking point to another bonding site.

[0025]

[0026] (In formula (3), R ７is a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a group represented by a combination of one or more hydrocarbon groups having 1 to 20 carbon atoms and one or more oxygen atoms, and * is R ６ represents the bonding site with the carbon atom to which it is bonded.)

[0027] According to one embodiment of the present invention, there are provided a copolymer that can give a cured product having excellent solvent resistance, a polymer mixture, and a resin composition containing the copolymer. Furthermore, according to one embodiment of the present invention, there is provided a cured product having good solvent resistance.

[0028] The copolymer, polymer mixture, resin composition, and cured product of the present invention are described in detail below. However, the present invention is not limited to the embodiments shown below. In this specification, the term "to" indicating a numerical range is used to mean that the numerical values ​​before and after the term are included as the lower and upper limits. In this specification, the units before and after the term "to" indicating a numerical range indicate the same unit unless otherwise specified. The term "process" used in this specification refers not only to an independent process, but also to a process that cannot be clearly distinguished from other processes, as long as the desired purpose of that process is achieved. Furthermore, unless otherwise specified, each component in the composition may be contained alone or in combination with two or more types. In this specification, the amount of each component in the composition refers to the total amount of the corresponding substance present in the composition when multiple components are present in the composition, unless otherwise specified. In this specification, a combination of two or more preferred embodiments is a more preferred embodiment. In this specification, "(meth)acrylic acid" refers to both "methacrylic acid" and "acrylic acid," or either one of them. "(Meth)acrylate" means both or either of "methacrylate" and "acrylate." "(Meth)acryloyloxy group" means both or either of "methacryloyloxy group" and "acryloyloxy group." In this specification, a monomer unit refers to a structural unit contained in a polymer compound and derived from a monomer compound. In this specification, the total solid content of a composition refers to the total mass of all components of the composition excluding the solvent. In addition, in this specification, the solid content concentration refers to the mass percentage of other components excluding the solvent relative to the total mass of the composition.

[0029] <Copolymer (A)> The copolymer according to the present invention (hereinafter sometimes referred to as "copolymer (A)") contains a structural unit (a) having a monovalent group represented by formula (1) (hereinafter sometimes simply referred to as "structural unit (a)") and a structural unit (b) having a monovalent group represented by formula (2) (hereinafter sometimes simply referred to as "structural unit (b)"). The copolymer has the above structure, and the resulting cured product has excellent solvent resistance. While the reason for this is not clear, the following mechanism is presumed. When copolymer (A) is reacted with the basic catalyst (b) described below, the fumaric acid-type double bond generated by the reaction between structural unit (a) and basic catalyst (b) undergoes Michael addition with structural unit (b) to form a carbon-carbon bond, thereby forming a highly crosslinked structure. As a result, a cured product with excellent solvent resistance is presumed to be obtained. Because copolymer (A) has the above structure, it also has excellent curability even under low-temperature conditions. Note that "low-temperature curability" means that the copolymer can be cured at temperatures of, for example, 100°C or lower. The components contained in the copolymer (A) will be described in detail below.

[0030] [Structural Unit (a)] The structural unit (a) is a structural unit derived from a monomer (m-a) (hereinafter also simply referred to as "monomer (m-a)") having a monovalent group represented by the following formula (1) (hereinafter also simply referred to as "group represented by formula (1)"). The structural unit (a) may be of only one type, or may be of two or more types. When the copolymer (A) is reacted with the basic catalyst (B) described below, the structural unit (a) can be converted from the group represented by the following formula (1) to a group having a dienophile moiety.

[0031]

[0032] In formula (1), R １ and R ２ are each independently a hydrocarbon group having 1 to 20 carbon atoms, and R ３ and R ４ are each independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and * represents a link to another binding site.

[0033] In formula (1), R １ and R２ are each independently a hydrocarbon group having 1 to 20 carbon atoms, preferably a hydrocarbon group having 1 to 5 carbon atoms, and more preferably a hydrocarbon group having 1 to 3 carbon atoms. １ and R ２ is preferably an alkyl group, more preferably a methyl group or an ethyl group, and particularly preferably an ethyl group. １ and R ２ may be the same or different. Since the monomer (m-a) described later can be easily produced, R １ and R ２ are preferably the same group.

[0034] In formula (1), R ３ and R ４ are each independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, preferably a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, more preferably a hydrogen atom or a methyl group, and even more preferably a hydrogen atom. ３ and R ４ may be the same or different, and are preferably the same group, since this allows for easy production of the monomer (ma) described below.

[0035] Copolymer (A) preferably has the above-mentioned structural unit (a) in its side chain, and more preferably has the above-mentioned structural unit (a) and the later-described structural unit (b) in its side chain. Note that the side chain refers to a molecular chain other than the relatively longest bonding chain (i.e., the main chain) in the molecule of the polymer compound constituting copolymer (A).

[0036] <Monomer (m-a)> The copolymer (A) preferably contains a structural unit derived from a monomer (m-a) that does not have a conjugated diene moiety or a carboxy group and has an ethylenically unsaturated bond and a group represented by formula (1). The method for synthesizing the monomer (m-a) having the group represented by formula (1) is not particularly limited, and a conventionally known method can be used. Examples of the monomer (m-a) include a compound obtained by reacting an isocyanate compound having an ethylenically unsaturated group in the molecule with a hydroxy group-containing compound represented by formula (8) described below. A urethane bond can be formed in the compound obtained by reacting the isocyanato group in the isocyanate compound with the hydroxy group in the hydroxy group-containing compound (hereinafter also referred to as a "urethanization reaction").

[0037] [Isocyanate Compound] The isocyanate compound used as a raw material for the monomer (m-a) is not particularly limited as long as it is an isocyanate compound having an ethylenically unsaturated group in the molecule. Examples of the ethylenically unsaturated group possessed by the isocyanate compound (hereinafter, sometimes simply referred to as "isocyanate compound") include a vinyl group and a (meth)acryloyloxy group. From the viewpoint of reactivity, a (meth)acryloyloxy group is preferred as the ethylenically unsaturated group. Examples of the isocyanate compound include isocyanate compounds represented by the following formula (1-4):

[0038]

[0039] In formula (1-4), R ５ａ represents a hydrogen atom or a methyl group. ６ａ is -CO-, -COOR ７ａ - (where R ７ａ is an alkylene group having 1 to 6 carbon atoms.) or COO-R ８ａ O-CONH-R ９ａ - (where R ８ａ is an alkylene group having 2 to 6 carbon atoms, and R ９ａ represents an alkylene group having 2 to 12 carbon atoms or an arylene group having 6 to 12 carbon atoms, which may have a substituent.

[0040] R in formula (1-4) ５ａ is preferably a hydrogen atom or a methyl group. ６ａ is -C(=O)-, -C(=O)OR ７ａ - (where R ７ａ is an alkylene group having 1 to 6 carbon atoms.) or C(═O)O—R ８ａ O-CONH-R ９ａ - (where R ８ａ is an alkylene group having 2 to 6 carbon atoms, and R ９ａ is an alkylene group having 2 to 12 carbon atoms or an arylene group having 6 to 12 carbon atoms, which may have a substituent. ６ａ is preferably -C(=O)OR from the viewpoint of easy availability of raw materials. ７ａ - (R ７ａ is an alkylene group having 1 to 6 carbon atoms, and —C(═O)OR ７ａ - and R ７ａ More preferably, is an alkylene group having 1 to 4 carbon atoms.

[0041] Specific examples of the isocyanate compound represented by the above formula (1-4) include 2-isocyanatoethyl (meth)acrylate, 2-isocyanatopropyl (meth)acrylate, 3-isocyanatopropyl (meth)acrylate, 2-isocyanato-1-methylethyl (meth)acrylate, 2-isocyanato-1,1-dimethylethyl (meth)acrylate, 4-isocyanatocyclohexyl (meth)acrylate, and methacryloyl isocyanate.

[0042] The isocyanate compound used as a raw material for the monomer (m-a) may also be a reaction product obtained by reacting an equimolar 2-hydroxyalkyl(meth)acrylate with a diisocyanate compound (i.e., 2-hydroxyalkyl(meth)acrylate:diisocyanate compound=1 mol:1 mol). The alkyl group of the 2-hydroxyalkyl(meth)acrylate is preferably an ethyl group or an n-propyl group, more preferably an ethyl group, from the viewpoint of ease of reaction with the diisocyanate compound.

[0043] The diisocyanate compound is not particularly limited, and examples thereof include hexamethylene diisocyanate, 2,4- (or 2,6-) tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), 3,5,5-trimethyl-3-isocyanatomethylcyclohexyl isocyanate (IPDI), m- (or p-) xylene diisocyanate, 1,3- (or 1,4-) bis(isocyanatomethyl) cyclohexane, and lysine diisocyanate.

[0044] Examples of isocyanate compounds other than the above-mentioned isocyanate compounds include 1,1-bis(methacryloyloxymethyl)methyl isocyanate, 1,1-bis(methacryloyloxymethyl)ethyl isocyanate, 1,1-bis(acryloyloxymethyl)methyl isocyanate, and 1,1-bis(acryloyloxymethyl)ethyl isocyanate.

[0045] Among the above, from the viewpoints of excellent curability when a resin composition containing the copolymer (A) is cured under low-temperature conditions and excellent solvent resistance of the resulting cured product, the isocyanate compound is preferably 2-isocyanatoethyl (meth)acrylate, 2-isocyanatopropyl (meth)acrylate, 3-isocyanatopropyl (meth)acrylate, 2-isocyanato-1-methylethyl (meth)acrylate, 1,1-bis(methacryloyloxymethyl)ethyl isocyanate, 2-isocyanato-1,1-dimethylethyl (meth)acrylate, 4-isocyanatocyclohexyl (meth)acrylate, or methacryloyl isocyanate, more preferably 2-isocyanatoethyl (meth)acrylate, 2-isocyanatopropyl (meth)acrylate, or 1,1-bis(methacryloyloxymethyl)ethyl isocyanate, and even more preferably 2-isocyanatoethyl (meth)acrylate or 2-isocyanatopropyl (meth)acrylate.

[0046] [Hydroxy Group-Containing Compound] The hydroxy group-containing compound represented by formula (8) is not particularly limited as long as it can react with the above-mentioned isocyanate compound, and examples thereof include malic acid esters, tartaric acid esters, citrate esters, etc. Among these, malic acid esters are preferred as the hydroxy group-containing compound because of their easy availability.

[0047]

[0048] In formula (8), R １ , R ２ , R ３ and R ４ are R in formula (1), respectively. １ , R ２ , R ３ and R ４ The same applies to the preferred embodiments.

[0049] The number of carbon atoms in the two ester moieties contained in the hydroxy group-containing compound represented by formula (8) (-(C=O)OR １ and -(C=O)OR ２ R in １ and R２ The number of carbon atoms is not particularly limited, but each independently is preferably 1 to 5, and more preferably 1 or 2. The hydroxy group-containing compound represented by formula (8) is particularly preferably diethyl malate.

[0050] [Method for synthesizing a monomer (m-a) having a group represented by formula (1)] The method for reacting the isocyanate compound with the hydroxy group-containing compound (i.e., urethanization reaction) is not particularly limited, and a conventionally known method can be used. The urethanization reaction can be carried out regardless of the presence or absence of a solvent. When the urethanization reaction is carried out using a solvent, the solvent to be used is not particularly limited as long as it is inactive to an isocyanato group, and known solvents can be used.

[0051] The urethanization reaction is generally preferably carried out at a temperature of −10° C. or higher and 90° C. or lower, more preferably at a temperature of 5° C. or higher and 70° C. or lower, and even more preferably at a temperature of 10° C. or higher and 40° C. or lower. When carrying out the urethanization reaction, a urethanization catalyst such as dibutyltin dilaurate; a polymerization inhibitor such as phenothiazine, p-methoxyphenol, or 2,6-di-tert-butyl-4-methylphenol (hereinafter also referred to as “BHT”); or the like may be used, if necessary.

[0052] The monomer (m-a) is preferably at least one compound selected from the group consisting of 2-[(diethyl malate)carbonylamino]ethyl(meth)acrylate and 2-[2-[(diethyl malate)carbonylamino]ethoxy]ethyl(meth)acrylate, and more preferably 2-[(diethyl malate)carbonylamino]ethyl acrylate.

[0053] Furthermore, the monomer (m-a) may be a commercially available product. Examples of commercially available products of the monomer (m-a) include AOI-MDE (registered trademark) (product name: 2-[(diethyl malate)carbonylamino]ethyl acrylate, manufactured by Resonac Co., Ltd.), MOI-MDE (registered trademark) (product name: 2-[2-[(diethyl malate)carbonylamino]ethoxy]ethyl methacrylate, manufactured by Resonac Co., Ltd.), and MOI-EG-MDE (registered trademark) (product name: 2-[2-[(diethyl malate)carbonylamino]ethoxy]ethyl methacrylate, manufactured by Resonac Co., Ltd.).

[0054] By containing the structural unit (a) in copolymer (A), when the resin composition containing copolymer (A) and the basic catalyst (B) described later is, for example, heated and cured, the group represented by formula (1) is converted into a group having a dienophile moiety by the action of the basic catalyst (B).Therefore, even when the resin composition containing copolymer (A) and the basic catalyst (B) is cured at a low temperature (for example, 100 ° C or less), it is easy to obtain a cured product with excellent solvent resistance.

[0055] The ratio of the number of structural units (a) to the total number of monomer units in copolymer (A) can be appropriately determined depending on the application of copolymer (A). The ratio of the number of structural units (a) to the total number of monomer units in copolymer (A) is preferably 1 to 99 mol%, more preferably 3 to 40 mol%, and even more preferably 5 to 30 mol%. When the ratio of the number of structural units (a) is 1 mol% or more, when a resin composition containing copolymer (A) and basic catalyst (B) is heat-cured, a sufficient number of dienophile moieties are formed by conversion from the group represented by formula (1). As a result, a sufficient amount of crosslinking in copolymer (A) is easily ensured by the Diels-Alder reaction between the dienophile moiety and the conjugated diene moiety. When the ratio of the number of structural units (a) is 99 mol% or less, the ratio of the number of structural units (b) to the total number of monomer units in copolymer (A) can be sufficiently ensured.

[0056] <Structural Unit (b)> The structural unit (b) is a structural unit derived from a monomer (mb) (hereinafter also simply referred to as "monomer (mb)") having a monovalent group represented by the following formula (2). It is preferable that the copolymer (A) has the structural unit (b) in its side chain. The structural unit (b) may be of one type alone, or may be of two or more types.

[0057]

[0058] In formula (2), R ５ is a hydrocarbon group having 1 to 20 carbon atoms, and R ６ is a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a group represented by the following formula (3), A represents -NH- or -O-, and * represents a linking portion to another bonding site. ５ and R ６ The hydrocarbon groups having 1 to 20 carbon atoms in R are each independently preferably hydrocarbon groups having 1 to 5 carbon atoms, more preferably hydrocarbon groups having 1 to 3 carbon atoms. ５ is preferably a hydrogen atom or a group represented by formula (3). A is preferably —NH—.

[0059]

[0060] In formula (3), R ７ is a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a group represented by a combination of one or more hydrocarbon groups having 1 to 20 carbon atoms and one or more oxygen atoms, and * is R ６ represents the bonding site with the carbon atom to which R is attached. ７ The hydrocarbon groups having 1 to 20 carbon atoms in R are each independently preferably hydrocarbon groups having 1 to 5 carbon atoms, more preferably hydrocarbon groups having 1 to 3 carbon atoms. ７ Examples of the group represented by a combination of one or more hydrocarbon groups having 1 to 20 carbon atoms and one or more oxygen atoms in the above formula include an alkoxy group having 1 to 20 carbon atoms, *—O—R ７Ａ -OR ７Ｂ A group represented by R ７Ａ is a divalent hydrocarbon group, and R ７Ｂ is a monovalent hydrocarbon group, and R７Ａ and R ７Ｂ The total number of carbon atoms is 20 or less.)

[0061] R in formula (3) ７ is OR ８ (The above R ８ is a hydrocarbon group having 1 to 20 carbon atoms) or a methyl group, and OR ８ (The above R ８ is a hydrocarbon group having 1 to 10 carbon atoms) or a methyl group, and OR ８ (The above R ８ is a linear or branched hydrocarbon group having 1 to 5 carbon atoms) or a methyl group, and OR ８ (The above R ８ is particularly preferably a group represented by:

[0062] <<Monomer (mb)>> The structural unit (b) is preferably a structural unit derived from a monomer (mb) represented by the following formula (4).

[0063]

[0064] In formula (4), R ８ represents a hydrogen atom or a methyl group, and R ９ represents a linear or branched divalent aliphatic saturated hydrocarbon group having 1 to 20 carbon atoms which may have an internal ether bond, or an aromatic hydrocarbon group, or a divalent alicyclic hydrocarbon group having 6 to 20 carbon atoms which may have an internal urethane bond; R １０ and R １１ are each independently a hydrocarbon group having 1 to 20 carbon atoms.

[0065] In formula (4), R ８ represents a hydrogen atom or a methyl group, and is preferably a hydrogen atom. ９R represents a linear or branched divalent aliphatic saturated hydrocarbon group having 1 to 20 carbon atoms (preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms) which may have an ether bond in the molecule, or an aromatic hydrocarbon group, or a divalent alicyclic hydrocarbon group having 6 to 20 carbon atoms which may have a urethane bond therein. Examples of divalent aromatic hydrocarbon groups include arylene groups, and examples of arylene groups include phenylene groups, biphenylene groups, naphthylene groups, phenanthrene groups, and anthrylene groups. Examples of divalent alicyclic hydrocarbon groups include cycloalkylene groups, cycloalkenylene groups, and groups in which two hydrogen atoms have been removed from fused polycyclic hydrocarbon groups, bridged ring hydrocarbon groups, spiro hydrocarbon groups, cyclic terpene hydrocarbon groups, etc. ９ is preferably an alkylene group having 1 to 8 carbon atoms, more preferably an alkylene group having 1 to 6 carbon atoms, still more preferably a linear alkylene group having 1 to 4 carbon atoms, and particularly preferably an ethylene group.

[0066] R １０ and R １１ are each independently preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 8 carbon atoms, still more preferably a methyl group or an ethyl group, and particularly preferably an ethyl group.

[0067] The monomer (mb) represented by formula (4) is preferably a blocked isocyanate compound. The monomer (mb) may be a single type or a combination of two or more types.

[0068] The method for synthesizing the monomer (mb) represented by formula (4) is not particularly limited, and known synthesis methods can be used. A suitable example of the method for synthesizing the monomer (mb) is a method of reacting an isocyanate compound (b-1-1) with a blocking agent (b-1-2).

[0069] <<Isocyanate Compound (b-1-1)>> The isocyanate compound (b-1-1) may be the same as the isocyanate compound used as a raw material for the monomer (mb).

[0070] [Blocking Agent] The blocking agent (b-1-2) is R １１ -H... Formula (3) and R １１ -H...at least one compound selected from the group consisting of salts of compounds represented by formula (3). １１ HA-C(COOR ５ａ ) (COOR ６ａ ) and R ５ａ and R ６ａ are R in formula (2), respectively. ５ and R ６ are the same as

[0071] The blocking agent (b-1-2) is preferably at least one compound selected from the group consisting of malonic acid diesters, malonic acid monoesters, acetoacetic acid esters, and malonic acid. From the viewpoint of suppressing the generation of impurities during synthesis, malonic acid diesters are more preferred, and malonic acid dialkyl esters are even more preferred.

[0072] Examples of malonic acid monoalkyl esters and malonic acid dialkyl esters include compounds obtained by reacting malonic acid with an aliphatic alcohol such as methanol, ethanol, isopropanol, n-propanol, n-butanol, isobutyl alcohol, sec-butyl alcohol, tert-butyl alcohol, or 2-ethylhexyl alcohol; an alicyclic alcohol such as cyclohexylmethanol; or an alcohol containing an aromatic ring such as benzyl alcohol. Furthermore, the malonic acid monoalkyl esters and malonic acid dialkyl esters may be mixed malonic acid esters obtained by reacting two different alcohols with malonic acid. Among these, in terms of the ease of volatilization of the alcohol, ease of availability, cost, and quality, dimethyl malonate or diethyl malonate is preferred as the malonic acid monoalkyl ester and dialkyl malonate, and diethyl malonate is more preferred.

[0073] R １１ Examples of salts of —H include salts of metals of Groups 1, 2, and 13 of the periodic table.１１ The salt of -H is preferably a sodium, potassium, magnesium, calcium or aluminum salt, more preferably a sodium or aluminum salt.

[0074] The molar ratio of the isocyanate compound (b-1-1) to the blocking agent (b-1-2) during synthesis of the monomer (mb) is preferably 10:1 to 1:10, more preferably 5:1 to 1:5. A molar ratio of 10:1 to 1:10 is preferred because loss of the monomer (mb) is minimal and the monomer (mb) can be obtained efficiently.

[0075] Monomer (mb) may be a commercially available product. Examples of commercially available products of monomer (mb) include Karenz (registered trademark) MOI-DEM (a reaction product of methacryloyloxyethyl isocyanate and diethyl malonate, manufactured by Resonac Co., Ltd., dissociation temperature of blocked isocyanate group: 90°C, dissociation rate: 90% by mass), Karenz MOI-BP (a reaction product of methacryloyloxyethyl isocyanate and 3,5-dimethylpyrazole, manufactured by Resonac Co., Ltd., dissociation temperature of blocked isocyanate group: 110°C, dissociation rate: 70% by mass), Karenz MOI-BM (a reaction product of methacryloyloxyethyl isocyanate and methyl ethyl ketoxime ... Examples of methacrylates include the product (manufactured by Resonac Co., Ltd., blocked isocyanato group dissociation temperature: 130°C, dissociation rate: 18% by mass), Karenz (registered trademark) MOI-OBE (manufactured by Resonac Co., Ltd., blocked isocyanato group dissociation temperature: 120°C, dissociation rate: 90% by mass), Karenz (registered trademark) AOI-DEM (manufactured by Resonac Co., Ltd., blocked isocyanato group dissociation temperature: 90°C, dissociation rate: 90% by mass), and 2-(methacryloyloxy)ethyl acetoacetate (manufactured by Tokyo Chemical Industry Co., Ltd., blocked isocyanato group does not dissociate), as well as the corresponding acrylates. These blocked isocyanato group-containing (meth)acrylates may be used alone or in combination of two or more.

[0076] The ratio of the number of structural units (b) contained relative to the total number of monomer units in copolymer (A) can be appropriately determined depending on the application of copolymer (A). The ratio of the number of structural units (b) contained relative to the total number of monomer units in copolymer (A) is preferably 1 to 99 mol%, more preferably 3 to 40 mol%, and even more preferably 5 to 30 mol%. When the ratio of the number of structural units (b) contained is in the range of 1 to 99 mol%, the ratio of the number of structural units (a) contained relative to the total number of monomer units in copolymer (A) can be sufficiently ensured.

[0077] [Other structural unit (c)] The copolymer (A) may, if necessary, contain a structural unit (c) other than the structural unit (a) and the structural unit (b) (hereinafter, also simply referred to as "other structural unit (c)"). The copolymer (A) may contain only one type of structural unit (c), or may contain two or more types of structural unit (c). The structural unit (c) is a structural unit derived from a monomer (m-c) other than the aforementioned monomers (m-a) and (m-b) (hereinafter, also simply referred to as "monomer (m-c)").

[0078] The other structural unit (c) is more preferably a structural unit derived from a conjugated diene moiety (excluding ethylenically unsaturated groups), a group represented by formula (1), or a monomer having an ethylenically unsaturated group.

[0079] Examples of the monomer (m-c) that forms the other structural unit (c) include (meth)acrylic acid esters, (meth)acrylic acid amides, vinyl compounds, styrene, unsaturated dicarboxylic acid diesters, unsaturated polybasic acid anhydrides, unsaturated carboxylic acids, and salts thereof.

[0080] Specific examples of (meth)acrylic acid esters include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, sec-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, neopentyl (meth)acrylate, benzyl (meth)acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. Acrylate, lauryl (meth)acrylate, dodecyl (meth)acrylate, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, ethylcyclohexyl (meth)acrylate, 1,4-cyclohexanedimethanol mono(meth)acrylate, rosin (meth)acrylate, norbornyl (meth)acrylate, 5-methylnorbornyl (meth)acrylate, 5-ethylnorbornyl (meth)acrylate, allyl (meth)acrylate, tetrahydrofurfuryl ( (meth)acrylate, 1,1,1-trifluoroethyl (meth)acrylate, perfluoroethyl (meth)acrylate, perfluoro-n-propyl (meth)acrylate, perfluoro-isopropyl (meth)acrylate, triphenylmethyl (meth)acrylate, cumyl (meth)acrylate, 3-(N,N-dimethylamino)propyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentanyl (meth)acrylate, isobornyl (meth)acrylate, adamantyl (meth)acrylate, naphthalene (meth)acrylate, anthracene (meth)acrylate, glycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, (3-ethyloxetan-3-yl)methyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2,3-dihydroxypropyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, N,Examples include N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, N-tert-butylaminoethyl (meth)acrylate, tetramethylpiperidyl (meth)acrylate, and hexamethylpiperidyl (meth)acrylate.

[0081] Specific examples of (meth)acrylic acid amides include (meth)acrylic acid amide, (meth)acrylic acid N,N-dimethylamide, (meth)acrylic acid N,N-diethylamide, (meth)acrylic acid N,N-dipropylamide, (meth)acrylic acid N,N-di-isopropylamide, (meth)acrylic acid anthracenylamide, N-isopropyl(meth)acrylamide, (meth)acrylic morpholine, and diacetone(meth)acrylamide.

[0082] Specific examples of vinyl compounds include norbornene (bicyclo[2.2.1]hept-2-ene), 5-methylbicyclo[2.2.1]hept-2-ene, 5-ethylbicyclo[2.2.1]hept-2-ene, tetracyclo[4.4.0.1 ２，５ .1 ７，１０ ] dodec-3-ene, 8-methyltetracyclo[4.4.0.1 ２，５ .1 ７，１０ ] dodec-3-ene, 8-ethyltetracyclo[4.4.0.1 ２，５ .1 ７，１０ ] dodec-3-ene, dicyclopentadiene, tricyclo[5.2.1.0 ２，６ ]dec-8-ene, tricyclo[5.2.1.0 ２，６ ]dec-3-ene, tricyclo[4.4.0.1 ２，５ ]undec-3-ene, tricyclo[6.2.1.0 １，８ ]undec-9-ene, tricyclo[6.2.1.0 １，８ ]undec-4-ene, tetracyclo[4.4.0.1 ２，５ .1 ７，１０ .0 １，６ ] dodec-3-ene, 8-methyltetracyclo[4.4.0.1 ２，５ .1 ７，１０ .0 １，６ ] dodec-3-ene, 8-ethylidenetetracyclo[4.4.0.1２，５ .1 ７，１２ ] dodec-3-ene, 8-ethylidenetetracyclo[4.4.0.1 ２，５ .1 ７，１０ .0 １，６ ] dodec-3-ene, pentacyclo[6.5.1.1 ３，６ .0 ２，７ .0 ９，１３ ]pentadec-4-ene, pentacyclo[7.4.0.1 ２，５ .1 ９，１２ .0 ８，１３ ] Pentadec-3-ene, 5-norbornene-2,3-dicarboxylic anhydride, (meth)acrylic acid anilide, (meth)acryloylnitrile, acrolein, vinyl chloride, vinylidene chloride, vinyl fluoride, vinylpyridine, vinyl acetate, vinyltoluene, and norbornene.

[0083] Specific examples of styrene include styrene, α-, o-, m-, and p-alkyl, nitro, cyano, and amide derivatives of styrene. Specific examples of unsaturated dicarboxylic acid diesters include diethyl citraconate, diethyl maleate, diethyl fumarate, and diethyl itaconate. Specific examples of unsaturated polybasic acid anhydrides include maleic anhydride, itaconic anhydride, and citraconic anhydride. Specific examples of unsaturated carboxylic acids include unsaturated monocarboxylic acids such as (meth)acrylic acid, crotonic acid, 2-pentenoic acid, and cinnamic acid; and unsaturated dicarboxylic acids such as fumaric acid, maleic acid, and itaconic acid. Of these, (meth)acrylic acid is preferred as the unsaturated carboxylic acid. Specific examples of salts include sodium styrenesulfonate. These monomers (m-c) may be used alone or in combination of two or more.

[0084] Among these, from the viewpoint of ease of copolymerization reaction with the monomer (m-a) and the monomer (m-b), the other structural unit (c) is preferably a structural unit derived from a (meth)acrylic acid ester, more preferably a structural unit derived from an alkyl (meth)acrylate, even more preferably a structural unit derived from an alkyl (meth)acrylate having an alkyl group having 1 to 10 carbon atoms, and particularly preferably a structural unit derived from methyl (meth)acrylate, butyl (meth)acrylate, or 2-ethylhexyl (meth)acrylate.

[0085] When the copolymer (A) contains other structural units (c), the ratio of the number of structural units (a), (b), and (c) contained relative to the total number of monomer units in the copolymer (A) can be appropriately determined depending on the application of the copolymer (A). When the copolymer (A) contains other structural units (c), the ratio of the number of structural units (a) contained relative to the total number of monomer units in the copolymer (A) is preferably 1 to 50 mol%, more preferably 3 to 40 mol%, and even more preferably 5 to 30 mol%. When the copolymer (A) contains other structural units (c), the ratio of the number of structural units (b) contained relative to the total number of monomer units in the copolymer (A) is preferably 1 to 50 mol%, more preferably 3 to 40 mol%, and even more preferably 5 to 30 mol%. When copolymer (A) contains other structural units (c), the ratio of the number of structural units (c) to the total number of monomer units in copolymer (A) is preferably 40 to 98 mol%, more preferably 50 to 90 mol%, and even more preferably 55 to 85 mol%. When the ratio of the number of structural units (c) to the total number of monomer units in copolymer (A) is 40 mol% or more, the effects of including structural units (c) are significant. Furthermore, gelation during the copolymerization reaction of monomers (m-a) and (m-b) is easily suppressed, and the storage stability, curability, solvent resistance, and other properties of the resin composition containing copolymer (A) are easily balanced. When the ratio of the number of structural units (c) to the total number of monomer units in copolymer (A) is 98 mol% or less, the ratio of the number of structural units (a) and (b) in copolymer (A) is sufficiently ensured, and therefore resin compositions containing copolymer (A) have good curability even at low temperatures and can produce cured products with excellent solvent resistance.

[0086] <Polymer Mixture> A polymer mixture according to another embodiment of the present invention comprises a polymer A comprising a structural unit (a) having a monovalent group represented by formula (1), and a polymer B comprising a structural unit (b) having a monovalent group represented by formula (2). The structural unit (a) having a monovalent group represented by formula (1) contained in polymer A has the same meaning as the structural unit (a) in the copolymer (A) described above, and preferred embodiments are also the same. The structural unit (b) having a monovalent group represented by formula (2) contained in polymer B has the same meaning as the structural unit (b) in the copolymer (A) described above, and preferred embodiments are also the same.

[0087] The content of polymer A in the polymer mixture is preferably 1 to 99 mass%, more preferably 50 to 99 mass%, based on the total mass of the polymer mixture. The content of polymer B in the polymer mixture is preferably 1 to 99 mass%, more preferably 50 to 99 mass%, based on the total mass of the polymer mixture. Polymer A and polymer B may each be contained alone or in combination of two or more types.

[0088] The polymer mixture may, if necessary, contain a polymer C containing a structural unit (c) other than the structural unit (a) and the structural unit (b) (the other structural unit (c)). The other structural unit (c) has the same meaning as the structural unit (c) in the copolymer (A) described above, and preferred embodiments are also the same. The content of polymer C in the polymer mixture is preferably 0 to 80% by mass, more preferably 0 to 60% by mass, based on the total mass of the polymer mixture.

[0089] <Resin composition> The resin composition according to the present invention preferably contains the copolymer (A), a basic catalyst (B), and a solvent (C). The resin composition according to the present invention may also contain the above-mentioned polymer mixture, a basic catalyst (B), and a solvent (C) instead of the copolymer (A). Each component of the resin composition will be described in detail below.

[0090] [Basic Catalyst (B)] The basic catalyst (B) is not particularly limited as long as it can form a double bond.

[0091] The basic catalyst (B) preferably has a pKa (acidity constant) of 12.5 or more at 25° C. Basic catalysts (B) corresponding to those having a pKa of 12.5 or more at 25° C. include those having a pKa of 12.5 or more in aqueous solution, and those that are too acidic to be measured in aqueous solution but whose pKa in aqueous solution converted from the results of measurement in an organic solvent is 12.5 or more.

[0092] The basic catalyst (B) is preferably a compound represented by the following formula (5): １１ N=CR １２ -NR １３ R １４ ...(5) In formula (5), R １１ is a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or —N(R １５ ) ２ A group represented by the formula (R １５ is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and two R １５ may be the same or different. １２ , R １３ and R １４ are each a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. １１ , R １２ , R １３ , R １４ and two R １５ Any two or more of the groups may be bonded to form a cyclic structure.

[0093] The basic catalyst (B) may be a compound represented by formula (5-2). １６ N=CR １７ -NR １８ R １９ ...(5-2) In formula (5-2), R １６ , R １７ , R １８ and R １９ is a hydrocarbon group. １６ and R １９ and form a ring structure. １６ and R １９ The sum of the carbon atoms in R is 3 to 20.１７ and R １８ and form a ring structure. １７ and R １８ The sum of the carbon atoms is 3 to 20.

[0094] In the compound represented by formula (5-2), R forming a cyclic structure １６ and R １９ The sum of the carbon atoms of R forming a cyclic structure is 3 to 20, and is preferably 5 to 10 because of easy availability. １７ and R １８ The sum of the carbon atoms of the groups is 3 to 20, and is preferably 5 to 10 because they are readily available.

[0095] Examples of the basic catalyst (B) include 1,8-diazabicyclo[5.4.0]-7-undecene (DBU) (pKa 12.5) or a salt thereof, 1,5-diazabicyclo[4.3.0]-5-nonene (pKa 12.7) or a salt thereof, 1,5,7-triazabicyclo[4.4.0]dec-5-ene or a salt thereof, triethylmethylammonium 2-ethylhexane salt, and 1,1,3,3-tetramethylguanidine (pKa 13.6) or a salt thereof. The basic catalyst (B) is preferably at least one compound selected from the group consisting of 1,8-diazabicyclo[5.4.0]-7-undecene or a salt thereof, 1,5-diazabicyclo[4.3.0]-5-nonene or a salt thereof, 1,5,7-triazabicyclo[4.4.0]dec-5-ene or a salt thereof, and triethylmethylammonium 2-ethylhexane salt. In particular, from the viewpoints of catalytic activity, compatibility with the solvent (C) described below, ease of availability, and the like, 1,8-diazabicyclo[5.4.0]-7-undecene (DBU) is preferred.

[0096] The content of the basic catalyst (B) in the resin composition is preferably 0.001 to 1 part by mass, more preferably 0.01 to 0.8 parts by mass, and even more preferably 0.1 to 0.5 parts by mass, per 100 parts by mass of the total of the copolymer (A) and the reactive diluent (D) (if the resin composition does not contain the reactive diluent (D), per 100 parts by mass of the copolymer (A)). When the content of the basic catalyst (B) is 0.001 parts by mass or more, it is preferable because it is easy to obtain a sufficient reaction rate to convert the structural unit (b) in the copolymer (A) into a dienophile moiety. When the content of the basic catalyst (B) is 1 part by mass or less, gelation of the resin composition containing the basic catalyst (B) is suppressed, and workability when applying the resin composition can be improved, resulting in excellent solvent resistance of the cured product obtained from the resin composition. The basic catalyst (B) may be used alone or in combination of two or more types.

[0097] [Solvent (C)] The resin composition preferably contains a solvent (C). The solvent (C) is not particularly limited as long as it is inert to the reaction for forming a double bond.Specific examples of the solvent (C) include (poly)alkylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, and 3-methoxy-1-butanol; hydroxy group-containing carboxylic acid esters such as methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl hydroxyacetate, and methyl 2-hydroxy-3-methylbutyrate; hydroxy group-containing solvents such as diethylene glycol, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate. (Poly)alkylene glycol monoalkyl ether acetates such as diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, tetrahydrofuran, and other ethers; methyl ethyl ketone, cyclohexanone, 2-heptanone, 3-heptanone, and other ketones; methyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl ethoxyacetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutylpropionate, and other methyl 3-methoxybutylpropionate. Examples of the solvent include esters such as acetoacetate, ethyl acetate, n-butyl acetate, i-propyl acetate, i-butyl acetate, n-amyl acetate, i-amyl acetate, n-butyl propionate, ethyl butyrate, n-propyl butyrate, i-propyl butyrate, ethyl pyruvate, n-propyl pyruvate, methyl acetoacetate, ethyl acetoacetate, and ethyl 2-oxobutyrate; aromatic hydrocarbons such as toluene and xylene; and hydroxy group-free solvents such as carboxylic acid amides such as N-methylpyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide. These solvents may be used alone or in combination of two or more.

[0098] Among these solvents (C), it is preferable to use ethers from the viewpoints of availability, cost, solubility and dispersibility of raw materials when preparing the resin composition, and storage stability of the resin composition. Specifically, it is more preferable to use one or more selected from propylene glycol monomethyl ether acetate, diethylene glycol methyl ethyl ether, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, and 3-methoxy-1-butanol.

[0099] The content of the solvent (C) in the resin composition is preferably 30 to 1,000 parts by mass, more preferably 50 to 800 parts by mass, per 100 parts by mass of the copolymer (A). When the content of the solvent (C) is 30 parts by mass or more, a resin composition having an appropriate viscosity depending on the application can be obtained. When the content of the solvent (C) is 1,000 parts by mass or less, the solvent (C) can be easily removed from a coating film formed by applying the resin composition to a substrate. The solvent (C) may be used alone or in combination of two or more types.

[0100] [Surfactant (D)] The resin composition preferably further contains a surfactant (D). The production of the emulsion of the copolymer (A) is preferably carried out in the presence of the surfactant (D). The surfactant is not particularly limited, but at least one of commonly used nonionic emulsifiers, anionic emulsifiers, and reactive surfactants can be used. The surfactant (D) is preferably an anionic emulsifier or a reactive surfactant, and a reactive surfactant is more preferred from the viewpoint of suppressing the surfactant from bleeding out to the surface of the copolymer (A) after drying the emulsion of the copolymer (A).

[0101] Examples of nonionic emulsifiers include polyoxyethylene alkyl ethers, polyoxyethylene alcohol ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene polycyclic phenyl ethers, polyoxyalkylene alkyl ethers, sorbitan fatty acid esters, polyoxyethylene fatty acid esters, and polyoxyethylene sorbitan fatty acid esters.

[0102] Examples of anionic emulsifiers include alkylbenzene sulfonates, alkyl sulfates, polyoxyethylene alkyl ether sulfates, polyoxyalkylene alkyl ether phosphates or salts thereof, polyoxyalkylene alkylphenyl ether phosphates or salts thereof, and fatty acid salts. Examples of salts include alkali metals such as sodium and potassium, ammonia, and amines.

[0103] Examples of reactive surfactants include those having structures such as those shown in formulas (5) to (7).

[0104]

[0105]

[0106]

[0107] In formulas (5) to (7), R ２１ , R ２３ , R ２４ , and R ２５ are each independently hydrogen or an alkyl group, R ２２ is an alkyl group or an alkylphenyl group, and A is —CH ２ -CH ２ M is an ammonium salt or a metal salt such as potassium or sodium; n is an integer of 2 to 20; and m is an integer of 0 to 20.

[0108] Examples of compounds represented by formula (5) include Aqualon (registered trademark) KH-10 and KH-5 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.). Examples of compounds represented by formula (6) include Adeka Reasoap (registered trademark) SE-10N (manufactured by ADEKA Corporation). Examples of compounds represented by formula (7) include Aqualon (registered trademark) HS-10 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.).

[0109] The content of the surfactant (D) is preferably 0.1 parts by mass or more and 10.0 parts by mass or less, more preferably 0.3 parts by mass or more and 7.0 parts by mass or less, and even more preferably 0.5 parts by mass or more and 5.0 parts by mass or less, relative to 100 parts by mass of the solid content of the copolymer (A), from the viewpoint of ensuring particle stability during copolymerization and suppressing an increase in viscosity. The surfactant (D) may be used alone or in combination of two or more types.

[0110] [Chain Transfer Agent (E)] The resin composition may further contain a chain transfer agent (E) as needed to adjust the molecular weight of the copolymer (A). The chain transfer agent (E) is not particularly limited, and known chain transfer agents can be used. Examples of the chain transfer agent (E) include alkyl mercaptans such as n-hexyl mercaptan, n-octyl mercaptan, t-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, and n-stearyl mercaptan; xanthogen compounds such as 2,4-diphenyl-4-methyl-1-pentene, 2,4-diphenyl-4-methyl-2-pentene, dimethyl xanthogen disulfide, and diisopropyl xanthogen disulfide; terpinolene, tetramethylthiuram disulfide, tetraethylthiuram disulfide, and tetramethylthiuram disulfide. Examples of the chain transfer agent (E) include thiuram compounds such as thiuram monosulfide; phenolic compounds such as 2,6-di-t-butyl-4-methylphenol and styrenated phenol; allyl compounds such as allyl alcohol; halogenated hydrocarbon compounds such as dichloromethane, dibromomethane, and carbon tetrabromide; vinyl ethers such as α-benzyloxystyrene, α-benzyloxyacrylonitrile, and α-benzyloxyacrylamide; triphenylethane, pentaphenylethane, acrolein, methacrolein, thioglycolic acid, thiomalic acid, and 2-ethylhexyl thioglycolate. The chain transfer agent (E) may be used alone or in combination of two or more. The content of the chain transfer agent is not particularly limited, but is typically 0 to 5.0 parts by mass per 100 parts by mass of the solids content of the copolymer (A).

[0111] [Polymerization initiator (F)] The resin composition may further contain a polymerization initiator (F). The production of the emulsion of the copolymer (A) is preferably carried out in the presence of the polymerization initiator (F). The polymerization initiator (F) may also be used in combination with a reducing agent to form a redox polymerization initiator. Examples of the reducing agent include potassium hydrogen sulfite, sodium bisulfite, potassium sulfite, and sodium sulfite.

[0112] The polymerization initiator (F) is not particularly limited, and known polymerization initiators can be used. Examples of the polymerization initiator (F) include inorganic polymerization initiators typified by persulfates such as potassium persulfate, sodium persulfate, and ammonium persulfate; 2,2-di(4,4-di(t-butylperoxy)cyclohexyl)propane, 1-di(t-hexylperoxy)cyclohexane, 1,1-di(t-butylperoxy)cyclohexane, 4,4-di(t-butylperoxy)n-butyl valerate, 2,2-di(t-butylperoxy)butane, t-butyl hydroperoxide, and cumene hydroperoxide. oxide, benzoyl peroxide, diisopropylbenzene hydroperoxide, p-menthane hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, t-butylcumyl peroxide, di-t-butyl peroxide, di-t-hexyl peroxide, di(2-t-butylperoxyisopropyl)benzene, dicumyl peroxide, diisobutyryl peroxide, di(3,5,5-trimethylhexanoyl) peroxide, dilauroyl peroxide , disuccinic acid peroxide, dibenzoyl peroxide, di(3-methylbenzoyl) peroxide, benzoyl(3-methylbenzoyl) peroxide, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di(4-t-butylcyclohexyl) peroxydicarbonate, di(2-ethylhexyl) peroxydicarbonate, di-sec-butyl peroxydicarbonate, cumyl peroxyneodecanate, 1,1,3,3-tetramethylbutyl peroxy Cineodecanate, t-hexylperoxyneodecanate, t-butylperoxyneodecanate, t-hexylperoxypivalate, t-butylperoxypivalate, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanate, t-hexylperoxy-2-ethylhexanate, t-butylperoxy-2-ethylhexanate, t-butylperoxylaurate, t-butylperoxy-3,5,Organic peroxide-based polymerization initiators such as 5-trimethylhexanate, t-hexylperoxyisopropyl monocarbonate, t-butylperoxyisopropyl monocarbonate, t-butylperoxy2-ethylhexyl monocarbonate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, t-butylperoxyacetate, t-hexylperoxybenzoate, t-butylperoxybenzoate, and 2,5-dimethyl-2,5-di(t-butylperoxy)hexane; hydroperoxide, azobisisobutyronitrile, 2,2'-azobis(isobutyrate)dimethyl, 4-4 Examples of suitable azo polymerization initiators include 2-2'-azobis(4-cyanovaleric acid), 2-2'-azobis[2-(2-imidazolin-2-yl)propane, 2-2'-azobis(propane-2-carboxamidine), 2-2'-azobis[N-(2-carboxyethyl)-2-methylpropanamide, 2-2'-azobis{2-[1-(2-hydroxyethyl)-2-imidazolin-2-yl]propane}, 2-2'-azobis(1-imino-1-pyrrolidino-2-methylpropane), and 2-2'-azobis{2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propanamide}. These polymerization initiators may be used alone or in combination of two or more.

[0113] The polymerization initiator (F) is preferably potassium persulfate, sodium persulfate, ammonium persulfate, t-butyl hydroperoxide, cumene hydroperoxide, benzoyl peroxide, hydroperoxide, azobisisobutyronitrile, or 2,2′-azobis(isobutyrate)dimethyl, and more preferably potassium persulfate, sodium persulfate, or ammonium persulfate because of their good solubility in water.

[0114] The content of the polymerization initiator (F) is preferably 0.01 to 5 parts by mass, more preferably 0.03 to 4 parts by mass, and even more preferably 0.05 to 3 parts by mass, per 100 parts by mass of the solid content of the copolymer (A). If the content of the polymerization initiator (F) is within the above range, the amount of residual monomer after the reaction is reduced and the influence of the structure derived from the polymerization initiator on physical properties is also suppressed, which is preferable. The polymerization initiator (F) may be used alone or in combination of two or more types.

[0115] The resin composition may contain additives other than the copolymer (A), the basic catalyst (B), the solvent (C), the surfactant (D), the chain transfer agent (E), and the polymerization initiator (F) (hereinafter also referred to as "other additives"). The other additives are not particularly limited, and examples thereof include known additives such as colorants, coupling agents, leveling agents, and polymerization inhibitors. The content of the other additives is not particularly limited as long as it does not impair the effects of the present invention, and is preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 1% by mass or less, relative to the total mass of the resin composition. The other additives may be contained alone, or two or more types may be contained. The other additives may be added when preparing the resin composition, when producing the copolymer (A), or may be residues of the raw material monomers used in the synthesis of the copolymer (A).

[0116] <Method for Preparing Resin Composition> The method for preparing the resin composition is not particularly limited, and the resin composition can be prepared using a known mixing device. Examples of methods for preparing the resin composition include mixing the copolymer (A), the basic catalyst (B), and the solvent (C) using a known mixing device. At this time, at least one selected from the group consisting of a surfactant (D), a chain transfer agent (E), a polymerization initiator (F), and other additives may be mixed together with the copolymer (A), the basic catalyst (B), and the solvent (C), as needed. The resin composition may also be produced by mixing the copolymer (A) and the solvent (C) to form a mixture, and then adding the basic catalyst (B) to the mixture, and, as needed, adding at least one selected from the group consisting of a surfactant (D), a chain transfer agent (E), a polymerization initiator (F), and other additives, and mixing the mixture.

[0117] Since the resin composition contains the copolymer (A) and the basic catalyst (B), when the resin composition is heated, a fumaric acid-type double bond is generated by the reaction between the structural unit (a) contained in the copolymer (A) and the basic catalyst (B), and this double bond then undergoes Michael addition with the structural unit (b) to form a carbon-carbon bond, thereby forming a high-order crosslinked structure. An example of the reaction pathway between the copolymer (A) and the basic catalyst (B) is shown below, but the present invention is not limited thereto.

[0118]

[0119]

[0120]

[0121] <Cured Product> The cured product according to the present invention is obtained by curing the resin composition described above. The method for curing the resin composition is not particularly limited, and any known curing method can be used, such as a method of irradiating with active energy rays such as ultraviolet light or visible light, or a method of heating.

[0122] The active energy rays are preferably electron beams or light in the wavelength range from ultraviolet to infrared. For example, an ultra-high pressure mercury light source or a metal halide light source can be used for ultraviolet rays, a metal halide light source or a halogen light source can be used for visible light rays, and a halogen light source can be used for infrared rays, but other light sources such as lasers and LEDs can also be used. The irradiation dose of the active energy rays is appropriately set depending on the type of light source, the thickness of the coating film, etc.

[0123] The heating temperature can be appropriately set depending on the purpose, but is preferably 50 to 100° C., more preferably 70 to 90° C. Within the above temperature range, a crosslinked structure is more likely to be formed.

[0124] The cured product according to the present invention contains a resin having a structural unit represented by the following formula (n): In addition to the resin having the structural unit represented by the following formula (n), the cured product may contain, for example, a basic catalyst, a solvent, etc., or may contain an unreacted monomer component having the structural unit represented by formula (n). Examples of the basic catalyst and solvent include the basic catalyst (B) and solvent (C) described above.

[0125]

[0126] (In formula (n), R ２ are each independently a hydrocarbon group having 1 to 20 carbon atoms, and R ５ is a hydrocarbon group having 1 to 20 carbon atoms, and R ６ represents a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a group represented by the following formula (3), A represents -NH- or -O-, and * represents a linking point to another bonding site.

[0127]

[0128] (In formula (3), R ７ is a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a group represented by a combination of one or more hydrocarbon groups having 1 to 20 carbon atoms and one or more oxygen atoms, and * is R ６ represents the bonding site with the carbon atom to which it is bonded.)

[0129] In addition, R in formula (n) ２is R in the above formula (1). ２ The same applies to the preferred embodiments. ５ and R ６ are A and R in the above formula (2), respectively. ５ and R ６ The same applies to the preferred embodiments. ７ is R in formula (3) in the above copolymer. ７ The same applies to the preferred embodiments.

[0130] The cured product can be used, for example, in automotive paints, industrial paints, marine paints, film coatings, pressure-sensitive adhesives, adhesives, photoresists, etc., and can also be suitably used as an interlayer insulating film, a protective film, or an image display element.

[0131] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to the following examples as long as it does not depart from the gist of the invention.

[0132] [Production Example 1] (Synthesis of Copolymer (A)) 112 g of propylene glycol monomethyl ether acetate as solvent (C) was placed in a flask equipped with a stirrer, a dropping funnel, a condenser, a thermometer, and a gas inlet tube, and the mixture was stirred while replacing with nitrogen gas and heated to 90°C. Next, 20.0 g (9.5 mol%) of 2-[(diethyl malate)carbonylamino]ethyl acrylate (manufactured by Resonac Co., Ltd., product name: AOI-MDE) as the monomer (m-a), 19.0 g (10 mol%) of malonic acid-2-[[[[2-[1-oxo-2-propenyl]oxy]ethyl]amino]carbonyl]-1,3-diethyl ester (manufactured by Resonac Co., Ltd., product name: AOI-DEM) as the monomer (m-b), 28.0 g (44 mol%) of methyl methacrylate (MMA) (manufactured by Mitsubishi Chemical Corporation) as the monomer (m-c), 33.0 g (36.5 mol%) of butyl acrylate (BuA) (manufactured by Nippon Shokubai Co., Ltd.), and 12.0 g of dimethyl 2,2'-azobis(2-methylpropionate) as the polymerization initiator (F) were mixed to prepare a mixed solution.

[0133] The entire amount of the mixed solution prepared above was added dropwise to the solvent (C) in a flask under a nitrogen gas atmosphere at normal pressure using a dropping funnel over 2 hours. After completion of the dropwise addition, the solution in the flask was stirred while undergoing a polymerization reaction at 90°C for 3 hours to produce the copolymer (A). To the reaction solution containing the copolymer (A) thus obtained, propylene glycol monomethyl ether acetate was added as the solvent (C) so that the concentration of components other than the solvent (i.e., the solids concentration) was 45% by mass, thereby obtaining a copolymer (A) solution of Production Example 1.

[0134] [Production Examples 2 to 12] Copolymer (A) solutions of Production Examples 2 to 12 were obtained in the same manner as Production Example 1, except that the monomers shown in Table 1 were used in the proportions shown in Table 1. The amounts of raw material monomers used in producing the copolymer (A) solutions of Production Examples 1 to 12 are shown in Table 1.

[0135] [Production Example 13] 35.0 g of deionized water, 0.5 g of Aqualon (registered trademark) KH-10 (Dai-ichi Kogyo Seiyaku Co., Ltd.) as an anionic reactive surfactant, and 420 mg of sodium hydrogen sulfite were placed in a 500 mL four-neck flask equipped with a stirrer, a condenser, and a thermometer, and the system was heated to 50°C in a water bath while purging with nitrogen gas. In a separate 300 mL glass beaker, 0.50 g (0.3 mol%) of sodium p-styrenesulfonate, 32.4 g (39.5 mol%) of butyl acrylate, 25.2 g (39.3 mol%) of methyl methacrylate, 20.0 g (9.5 mol%) of 2-[(diethyl malate)carbonylamino]ethyl acrylate (manufactured by Resonac Corporation, product name: AOI-MDE (registered trademark)) as monomer (m-a), and malonic acid-2-[[[[2-[ An emulsion was prepared by vigorously stirring with a stirrer tip into a container heated to 50°C containing 22.1 g (11.4 mol%) of 1-oxo-2-propenyl[oxy]ethyl[amino]carbonyl]-1,3-diethyl ester (manufactured by Resonac Corporation, product name: AOI-DEM®), 0.50 g of 2-ethylhexyl thioglycolate as a chain transfer agent, 48.5 g of deionized water, and 2.4 g of Aqualon® KH-10 (Dai-ichi Kogyo Seiyaku Co., Ltd.) as an anionic reactive surfactant. 4.8 g of the prepared emulsion was added to a container heated to 50°C, and then separately prepared catalyst solution A (65 mg of potassium persulfate, 1.2 g of deionized water) was added all at once. 30 minutes after the addition, the remaining emulsion was added over 2 hours, and simultaneously, separately prepared catalyst solution B (0.39 g of potassium persulfate, 7.4 g of deionized water) was added over 3 hours. After the addition of catalyst solution B was completed, the mixture was further aged for 1.5 hours. After aging was completed, the mixture was cooled to below 30°C and neutralized with aqueous ammonia to a pH of 7.5 or higher to obtain the target copolymer emulsion. No residual monomers were detected in the copolymer emulsion except for 1600 ppm of n-butyl acrylate, confirming that the composition of the charged copolymer was substantially the same as the charged monomer composition. The solids concentration of the copolymer emulsion was 46.75% by mass.

[0136]

[0137] In Table 1, "-" means that the corresponding component is not included. Details of the monomers listed in Table 1 are as follows: "Monomer (m-a) having a group represented by formula (1)" AOI-MDE (registered trademark): 2-[(diethyl malate)carbonylamino]ethyl acrylate (manufactured by Resonac Co., Ltd., product name)

[0138]

[0139] MOI-MDE (registered trademark): 2-[(diethyl malate)carbonylamino]ethyl methacrylate (manufactured by Resonac Corporation, product name)

[0140]

[0141] MOI-EG-MDE (registered trademark): 2-[2-[(diethyl malate)carbonylamino]ethoxy]ethyl methacrylate (manufactured by Resonac Corporation, product name)

[0142]

[0143] "Monomer (m-b) having a group represented by formula (2)" AOI-DEM (registered trademark): malonic acid-2-[[[[2-[1-oxo-2-propenyl]oxy]ethyl]amino]carbonyl]-1,3-diethyl ester (manufactured by Resonac Corporation, product name)

[0144]

[0145] MAE: 2-(methacryloyloxy)ethyl acetoacetate (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0146]

[0147] MOI-OBE (registered trademark): butanoic acid-2-[[[2-[(2-methyl-1-oxy-2-pyropenyl)oxy]ethyl]amino]carboxy]-3-oxy-ethyl ester (manufactured by Resonac Corporation, product name)

[0148]

[0149] MOI-DEM (registered trademark): Malonic acid-2-[[[[2-[2-methyl-1-oxo-2-propenyl]oxy]ethyl]amino]carbonyl]-1,3-diethyl ester (manufactured by Resonac Corporation, product name)

[0150]

[0151] "Other Monomers (m-c)" HEMA: 2-hydroxyethyl methacrylate MAA: methacrylic acid (manufactured by Kuraray Co., Ltd.) MMA: methyl methacrylate (manufactured by Mitsubishi Chemical Corporation) BuA: butyl acrylate (manufactured by Nippon Shokubai Co., Ltd.) 2-hydroxyethyl methacrylate (manufactured by Kanto Chemical Co., Ltd.) NaSS: sodium styrenesulfonate (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0152] [Weight-Average Molecular Weight (Mw)] The weight-average molecular weights (Mw) of the copolymer (A) in the copolymer (A) solutions prepared above in Production Examples 1 to 13 are shown in Table 1. The weight-average molecular weights (Mw) of the copolymer (A) in Production Examples 1 to 13 were calculated by the following method. 1.5 mL of tetrahydrofuran (THF) was added to approximately 0.1 g of the copolymer emulsion obtained above, and the mixture was mixed by hand to dissolve. The mixture was then measured by GPC (gel permeation chromatography), and the weight-average molecular weight (Mw) of the copolymer in the emulsion was calculated in terms of polystyrene. For the GPC measurement, a GPC system manufactured by Shimadzu Corporation was used as the GPC measurement device, and a differential refractive index detector RID-10A was used as the detector. Three Shodex (registered trademark) LF-804 columns and one KF-801 column manufactured by Showa Denko K.K. were used. The GPC measurement was performed under conditions of a column temperature of 40°C and a flow rate of 1.0 mL / min.

[0153] [Example 1] In a flask under normal pressure and in a nitrogen gas atmosphere, the copolymer (A) solution obtained in Production Example 1 above was mixed with 1,8-diazabicyclo[5.4.0]-7-undecene (DBU) (manufactured by San-Apro Co., Ltd.) as a basic catalyst (B) in the proportions (parts by mass) shown in Table 2 to prepare resin compositions.

[0154] [Evaluation of Solvent Resistance (Film Remaining Rate)] The resin composition prepared above was applied to a glass substrate (alkali-free glass substrate) measuring 5 cm in length and 2 cm in width using a bar coder (#34) to form a coating film with a film thickness of 78 μm. The glass substrate on which the coating film was formed was then heat-treated at a temperature of 80°C, 100°C, 120°C, or 140°C for 30 minutes to volatilize the solvent (C) in the coating film and perform a baking treatment to form a cured film on the glass substrate. The mass of the resulting cured film was measured. Next, the glass substrate on which the cured film was formed was immersed in 100 g of acetone at 25°C for 24 hours. After 24 hours, the glass substrate was removed from the acetone and dried at 110°C for 1 hour. After drying, the mass of the cured film remaining on the glass substrate was measured, and the film remaining rate (%) was calculated using the following formula to evaluate the solvent resistance of the cured film. Residual film ratio = (mass of cured film after acetone immersion / mass of cured film before acetone immersion) x 100 (%) In other words, the closer the residual film ratio is to 100%, the better the solvent resistance of the cured film. In terms of evaluation, when the residual film ratio is 30% or more when heat treated at temperatures of 120°C and 140°C, it is judged to be at a level that is acceptable for practical use, and this was set as the pass mark.

[0155] [Examples 2 to 10 and Comparative Examples 2 to 4] Resin compositions were prepared in the same manner as in Example 1, except that the copolymer (A) solution in Example 1 was changed to the copolymer (A) solution shown in Table 2. In addition, the solvent resistance of the obtained resin compositions was evaluated in the same manner as in Example 1. The results are shown in Table 2.

[0156] Comparative Example 1 A resin composition was prepared in the same manner as in Example 1, except that the basic catalyst (B) was not used. The solvent resistance of the obtained resin composition was evaluated in the same manner as in Example 1. The results are shown in Table 2.

[0157]

[0158] [Examples 11 to 15] Resin compositions were prepared in the same manner as in Example 1, except that the copolymer (A) solution and basic catalyst (B) were changed as shown in Table 3. In addition, the solvent resistance of the obtained resin compositions was evaluated in the same manner as in Example 1. The results are shown in Table 3.

[0159]

[0160] In Table 3, "-" means that the corresponding component is not contained. Details of the basic catalyst (B) are as follows. "Basic catalyst (B)" SA-603: Formate salt of 1,8-diazabicyclo[5.4.0]undecene-7 (DBU) (registered trademark) (manufactured by San-Apro Co., Ltd., product name: U-CAT SA-603) SA-1: Phenol salt of 1,8-diazabicyclo[5.4.0]undecene-7 (DBU) (registered trademark) (manufactured by San-Apro Co., Ltd., product name: U-CAT SA-1) 18X: Triethylmethylammonium 2-ethylhexane salt (manufactured by San-Apro Co., Ltd., product name: U-CAT 18X) TBD: 1,5,7-triazabicyclo[4.4.0]dec-5-ene (manufactured by Tokyo Chemical Industry Co., Ltd.) DBN: 1,5-diazabicyclo[4.3.0]nonene-5 (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0161] The basic catalyst (B) used in Examples 11 to 15 is a catalyst whose catalytic activity is expressed by heat. Therefore, although the residual film ratio at a heating temperature of 80°C in Examples 11 to 15 was lower than in other Examples, it was confirmed that the reaction initiation temperature (i.e., crosslinking temperature) could be controlled by selecting the type of basic catalyst.

[0162] [Example 16] Resin compositions were prepared in the same manner as in Example 1, except that the copolymer (A) solution used in Example 1 was changed to that shown in Table 4. The solvent resistance of the resulting resin compositions was evaluated in the same manner as in Example 1. The results are shown in Table 4.

[0163]

[0164] It can be seen that the cured products obtained from the resin compositions of Examples 1 to 16 exhibit superior solvent resistance and also have low-temperature curing properties compared to the cured products obtained from the resin compositions of Comparative Examples 1 to 4.

Claims

1. A copolymer containing a structural unit (a) having a monovalent group represented by the following formula (1) and a structural unit (b) having a monovalent group represented by the following formula (2). (In formula (1), R １ and R ２ are each independently a hydrocarbon group having 1 to 20 carbon atoms, R ３ and R ４ are each independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and * represents a linking portion with another bonding site.) (In formula (2), R ５ is a hydrocarbon group having 1 to 20 carbon atoms, R ６ is a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms or a group represented by the following formula (3), A represents -NH- or -O-, and * represents a linking portion with another bonding site.) (In formula (3), R ７ is a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms or a group represented by a combination of one or more hydrocarbon groups having 1 to 20 carbon atoms and one or more oxygen atoms, and * represents a bonding site with the carbon atom to which R ６ in formula (2) is bonded.) 2. The copolymer according to claim 1, having the structural unit (a) and the structural unit (b) in the side chain.

3. R in the formula (3) ７ is OR ８ or a group represented by (wherein R ８ represents a hydrocarbon group having 1 to 20 carbon atoms), or a methyl group. The copolymer according to claim 1.

4. The copolymer according to claim 1, wherein the constitutional unit (b) is a constitutional unit derived from a monomer (m-b) represented by the following formula (4). (In formula (4), R ８ represents a hydrogen atom or a methyl group, and R ９ represents a linear or branched divalent aliphatic saturated hydrocarbon group having 1 to 20 carbon atoms which may have an ether bond inside, an aromatic hydrocarbon group, or a divalent alicyclic hydrocarbon group having 6 to 20 carbon atoms which may have a urethane bond inside, and R １０ and R １１ are each independently a hydrocarbon group having 1 to 20 carbon atoms.) 5. R in the formula (1) １ and R ２ are each independently a hydrocarbon group having 1 to 3 carbon atoms, and R ３ and R ４ are each independently a hydrogen atom or a methyl group, the copolymer according to claim 1.

6. The copolymer according to claim 1, wherein the proportion of the content of the structural unit (a) with respect to the total number of monomer units of the copolymer is 1 to 99 mol%, and the proportion of the content of the structural unit (b) with respect to the total number of monomer units of the copolymer is 1 to 99 mol%.

7. The copolymer according to claim 1, further containing other structural units (c), wherein the other structural units (c) include structural units derived from alkyl (meth)acrylate.

8. The copolymer according to claim 1, further containing other structural units (c), wherein the other structural units (c) include structural units derived from alkyl (meth)acrylate, the proportion of the content of the structural unit (a) with respect to the total number of monomer units of the copolymer is 1 to 50 mol%, the proportion of the content of the structural unit (b) with respect to the total number of monomer units of the copolymer is 1 to 50 mol%, and the proportion of the content of the structural unit (c) with respect to the total number of monomer units of the copolymer is 40 to 98 mol%.

9. The copolymer according to claim 1, wherein A in the formula (2) is -NH-.

10. A resin composition containing the copolymer according to any one of claims 1 to 8, a basic catalyst (B), and a solvent (C).

11. The resin composition according to claim 10, wherein the basic catalyst (B) includes at least one selected from the group consisting of 1,8-diazabicyclo[5.4.0]-7-undecene or a salt thereof, 1,5-diazabicyclo[4.3.0]-5-nonene or a salt thereof, 1,5,7-triazabicyclo[4.4.0]dec-5-ene or a salt thereof, and triethylmethylammonium 2-ethylhexane salt.

12. A cured product obtained by curing the resin composition according to claim 10.

13. A polymer mixture comprising a polymer A containing a structural unit (a) having a monovalent group represented by the following formula (1) and a polymer B containing a structural unit (b) having a monovalent group represented by the following formula (2). (In formula (1), R １ and R ２ are each independently a hydrocarbon group having 1 to 20 carbon atoms, R ３ and R ４ are each independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and * represents a linking portion with another bonding site.) (In formula (2), R ５ is a hydrocarbon group having 1 to 20 carbon atoms, R ６ is a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms or a group represented by the following formula (3), A represents -NH- or -O-, and * represents a linking portion with another bonding site.) (In formula (3), R ７ is a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms or a group represented by a combination of one or more hydrocarbon groups having 1 to 20 carbon atoms and one or more oxygen atoms, and * represents a bonding site with the carbon atom to which R ６ in formula (2) is bonded.) 14. The polymer mixture according to claim 13, wherein A in the formula (2) is -NH-.

15. A cured product containing a resin having a structural unit represented by the following formula (n). (In formula (n), R ２ are each independently a hydrocarbon group having 1 to 20 carbon atoms, R ５ is a hydrocarbon group having 1 to 20 carbon atoms, R ６ is a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms or a group represented by the following formula (3), A represents -NH- or -O-, and * represents a linking portion with another bonding site.) (In formula (3), R ７ is a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms or a group represented by a combination of one or more hydrocarbon groups having 1 to 20 carbon atoms and one or more oxygen atoms, and * represents a bonding site with the carbon atom to which R ６ in formula (n) is bonded.)

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