WO2023085154A1 - Copolymer emulsion, and one-pack type thermosetting resin composition, two-pack type thermosetting resin composition, coating material, resin cured film and coating film each using said copolymer emulsion - Google Patents

Abstract

The present invention provides: a copolymer emulsion which has excellent polymerization stability; a thermosetting resin composition which contains this copolymer emulsion and has excellent curability at low temperatures; a coating material which contains this thermosetting resin composition; a resin cured film which is obtained by curing this thermosetting resin composition; and a coating film which comprises this resin cured film.　The present invention includes an invention of a copolymer emulsion which contains water and a copolymer (A) that is represented by formula (1) and comprises a constituent unit (A-1) that is obtained by blocking an isocyanato group with a blocking agent and a constituent unit (A-2) that has an aromatic hydrocarbon group, wherein 0.1% by mole to 40% by mole of the constituent unit (A-1) is contained if the sum of all constituent units is taken as 100% by mole. (In formula (1), R¹ represents a hydrogen atom or a methyl group; R² represents a divalent to tetravalent aliphatic saturated hydrocarbon group having a straight or branched chain and 1 to 20 carbon atoms, while optionally having an ether bond, or a divalent alicyclic hydrocarbon group or aromatic hydrocarbon group having 6 to 20 carbon atoms, while optionally having a urethane bond; R³ represents a residue of R³-H, which is the blocking agent, or a salt thereof, and contains an aromatic ring; and n is 1 or 2.)

Description

Copolymer emulsion and one-component thermosetting resin composition, two-component thermosetting resin composition, paint, cured resin film and coating film using the copolymer emulsion

The present invention relates to a copolymer emulsion, a one-component thermosetting resin composition, a two-component thermosetting resin composition, a paint, a cured resin film and a coating film using the copolymer emulsion.

A blocked isocyanate compound is a compound 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 isocyanate group. Because the isocyanato group is blocked, the blocked isocyanate compound does not necessarily need to be prepared and stored separately from the compound having a functional group such as an active hydrogen group that reacts with the isocyanato group, and can be prepared and stored as a single component. It is also possible to keep Therefore, blocked isocyanate compounds are widely used in adhesives, coating agents, molding materials, resin compositions and the like. Moreover, in recent years, water-based resin compositions have attracted attention due to the heightened awareness of global environmental protection.

For example, in Patent Document 1, an ethylenically unsaturated monomer having a urea group obtained by reacting an ethylenically unsaturated monomer having an isocyanate group with an amine, and glyoxal under the condition of pH 6 to 8. Obtained by emulsion polymerization of a monomer composition comprising an ethylenically unsaturated monomer having a 4,5-dihydroxy-2-imidazolidinone group and other ethylenically unsaturated monomers obtained by reaction , a one-part crosslinkable polymer emulsion composition, and the like.

Patent Document 2 discloses a vinyl monomer (A) containing an isocyanate group blocked as a sulfurous acid or bisulfite adduct, and an ethylenically unsaturated compound (B) containing an active hydrogen group reactive with the isocyanate group. or a polymer obtained by polymerizing the vinyl monomer (A), the ethylenically unsaturated compound (B), and another ethylenically unsaturated compound (C) and wherein the vinyl monomer (A) contains a predetermined compound.

Patent Document 3 discloses a water-dispersible blocked isocyanate composition containing a blocked isocyanate in which the isocyanate group is blocked by a blocking agent, and a dispersant containing a predetermined surfactant without containing a protective colloid agent. .

JP 2010-59239 A Japanese Patent No. 3517821 Japanese Patent No. 5563864

In Patent Document 1, a polymer emulsion is dried at 110° C. for 10 minutes to prepare a resin, but the polymerization stability of the polymer emulsion is not examined.
In Patent Document 2, even if the dispersion of the aqueous resin composition was left at room temperature for 3 months, it showed excellent stability without precipitation, but the temperature during heat curing of the aqueous resin composition was 130 ° C. It was 200°C.
Patent Document 3 discloses that no phase separation was visually observed even when a water-dispersed blocked isocyanate composition was left at 25°C for one week. °C to 160 °C.
Therefore, the aqueous resin composition has room for improvement in terms of polymerization stability and curability at lower temperatures.

The present invention has been made to solve the above problems, and includes a copolymer emulsion having excellent polymerization stability, and a thermal emulsion containing the copolymer emulsion and having excellent curability at low temperatures. An object of the present invention is to provide a curable resin composition, a paint containing the thermosetting resin composition, a cured resin film obtained by curing the thermosetting resin composition, and a coating film containing the cured resin film.

The present invention includes the following aspects [1] to [20].
[1] A copolymer containing a structural unit (A-1) in which an isocyanato group is blocked with a blocking agent and a structural unit (A-2) having an aromatic hydrocarbon group, represented by the following formula (1) ( A) and water,
A copolymer emulsion containing 0.1 mol % or more and 40 mol % or less of the structural unit (A-1) when the total of all structural units is 100 mol %.

In formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² represents a straight or branched chain or divalent to tetravalent saturated aliphatic hydrocarbon having 1 to 20 carbon atoms which may have an ether bond. represents a hydrogen ^group , or a divalent alicyclic hydrocarbon group or aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a ^urethane bond; It represents a salt residue, contains an aromatic ring, and n represents 1 or 2.

[2] The copolymer emulsion according to [1], wherein the structural unit (A-1) is represented by the following formula (1-1).

In formula (1-1), R ¹ and R ³ are the same as the symbols in formula (1), and R ^2-2 is a divalent aliphatic having 2 to 4 carbon atoms which may have an ether bond. Indicates a saturated hydrocarbon group.

[3] The copolymer emulsion according to [1] or [2], wherein the structural unit (A-1) is represented by the following formula (1-2).

In formula (1-2), R ¹ and R ³ have the same meanings as the symbols in formula (1).

[4] The copolymer emulsion according to [1], wherein the structural unit (A-1) is represented by the following formula (1-3).

In formula (1-3), R ¹ , R ² and n have the same meanings as those in formula (1), and R ^3-2 represents the residue of R ³ —H or a salt thereof as the blocking agent. , R ^3-2 is

or

indicate.

[5] The copolymer emulsion according to any one of [1] to [4], wherein the structural unit (A-2) is represented by the following formula (2).

In formula (2), R ⁴ is a hydrogen atom, a linear or branched aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms, or an optionally substituted aromatic group having 6 to 20 carbon atoms. represents a hydrocarbon group, R ⁵ represents a divalent aliphatic saturated hydrocarbon group having 0 to 8 carbon atoms which may have an ester bond and/or an ether bond, R ⁶ represents a hydrogen atom of which is a thiol group, a sulfo group, a nitro group, an amino group, a chlorine atom, a fluorine atom, a bromine atom, an iodine atom, an astatine atom, a hydroxy group, an aliphatic saturated hydrocarbon group containing a linear or branched chain having 1 to 4 carbon atoms, a carboxy group, an alkoxy group having 1 to 4 carbon atoms, a carboxyester group having 1 to 4 carbon atoms in the ester moiety, or an aromatic hydrocarbon group having 6 to 20 carbon atoms which may be substituted with a carbonyl group having 0 to 4 carbon atoms; indicates

[6] Containing 1.0 mol% or more and 99.5 mol% or less of the structural unit (A-2) when the total of all the structural units of the copolymer (A) is 100 mol%, [1 ] to [5].

[7] of [1] to [6], wherein the copolymer (A) further contains a structural unit (A-3) represented by the following formula (3) as a structural unit of the copolymer (A): A copolymer emulsion according to any one of the above.

In formula (3), R ⁷ represents a hydrogen atom or a linear or branched C 1-4 aliphatic saturated hydrocarbon group. ^R8 is a hydrogen atom substituted with a hydroxy group, an acyl group, an alkoxy group, a carboxy group, a thiol group, a sulfo group, a nitro group, an amino group, a chlorine atom, a fluorine atom, a bromine atom, an iodine atom, or an astatine atom; C 1-18 aliphatic saturated hydrocarbon group with no aromatic ring.

[8] containing 0 mol% or more and 94.5 mol% or less of the structural unit (A-3) when the total of all structural units of the copolymer (A) is 100 mol%; The copolymer emulsion described.

[9] The copolymer emulsion according to any one of [1] to [8], which contains a basic salt containing an acid having a pKa of 2 or more and an alkali metal.

[10] The copolymer (A) further comprises a structural unit (A-4) represented by the following formula (4-1) or the following formula (4-2) as a structural unit of the copolymer (A) The copolymer emulsion according to any one of [1] to [9].

In formula (4-1), R ⁹ , R ¹⁰ and R ¹¹ each independently contain a hydrogen atom, or a linear or branched chain having 1 to 15 carbon atoms which may contain an ester bond and/or a carboxy group. Indicates a hydrocarbon group.

In formula (4-2), R ¹² represents a hydrogen atom or a saturated aliphatic hydrocarbon group having 1 to 4 carbon atoms including a linear or branched chain having 1 to 4 carbon atoms, and R ¹³ represents an ester bond and / or represents a C 1-8 divalent aliphatic saturated hydrocarbon group or a C 6-20 aromatic hydrocarbon group which may have a carbonyl group.

[11] In [10], containing 0 mol% or more and 20.0 mol% or less of the structural unit (A-4) when the total of all structural units of the copolymer (A) is 100 mol% The copolymer emulsion described.

[12] The copolymer emulsion according to any one of [1] to [11], wherein the structural unit (A-2) is represented by formula (10).

In formula (10), R ¹⁴ represents a hydrogen atom or a methyl group, R ¹⁵ represents an alkylene group having 1 to 4 carbon atoms, and X represents an aromatic group.

[13] A one-part thermosetting resin composition containing the copolymer emulsion according to any one of [1] to [12].

[14] A paint containing the one-component thermosetting resin composition described in [13].

[15] A cured resin film (F) obtained by curing the one-component thermosetting resin composition described in [13].

[16] A coating film (G) including the cured resin film (F) described in [15].

[17] A two-part thermosetting resin composition comprising the copolymer emulsion according to any one of [1] to [12] and an acrylic polyol polymer emulsion (J).

[18] A paint containing the two-component thermosetting resin composition according to [17].

[19] A cured resin film (M) obtained by curing the two-component thermosetting resin composition described in [17].

[20] A coating film (N) containing the cured resin film (M) described in [19].

According to the present invention, a copolymer emulsion having excellent polymerization stability, a thermosetting resin composition containing the copolymer emulsion and having excellent curability at low temperatures, and the thermosetting resin composition It is possible to provide a coating containing the thermosetting resin composition, a cured resin film obtained by curing the thermosetting resin composition, and a coating film containing the cured resin film.

Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the embodiments shown below.

In this specification, the notation of (meth)acrylate means that either acrylate or methacrylate may be used. Moreover, what is described as (meth)acrylic acid means that either acrylic acid or methacrylic acid may be used.

<Copolymer emulsion>
One embodiment of the present invention comprises a structural unit (A-1) in which an isocyanato group is blocked with a blocking agent, represented by the following formula (1), and a structural unit (A-2) having an aromatic hydrocarbon group. and a copolymer (A) containing water,
A copolymer emulsion containing 0.1 mol % or more and 40 mol % or less of the structural unit (A-1) when the total of all structural units is 100 mol %.

In formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² represents a straight or branched chain or divalent to tetravalent saturated aliphatic hydrocarbon having 1 to 20 carbon atoms which may have an ether bond. represents a hydrogen ^group , or a divalent alicyclic hydrocarbon group or aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a ^urethane bond; It represents a salt residue, contains an aromatic ring, and n represents 1 or 2.

[Copolymer (A)]
The copolymer (A) includes a structural unit (A-1) represented by formula (1) (hereinafter also referred to as "structural unit (A-1)") and a structural unit having an aromatic hydrocarbon group described later. (A-2) (hereinafter also referred to as “structural unit (A-2)”). The copolymer (A) further includes a structural unit (A-3) represented by formula (3) described later (hereinafter also referred to as "structural unit (A-3)"), and/or formula (4 ) (hereinafter also referred to as “structural unit (A-4)”).

[Structural unit (A-1)]
The structural unit (A-1) is represented by the following formula (1).

In formula (1), R ¹ represents a hydrogen atom or a methyl group. R ² is a C 1-20, preferably C 1-8 divalent to tetravalent, preferably divalent aliphatic saturated hydrocarbon group containing a linear or branched chain which may have an ether bond, or It represents a divalent alicyclic hydrocarbon group or aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a urethane bond. R ³ represents the residue of R ³ --H or a salt thereof, which is a blocking agent to be described later, and contains an aromatic ring. The aromatic ring includes a cyclic structure possessed by a polycyclic aromatic hydrocarbon, preferably a benzene ring or a pyrazole ring. n represents 1 or 2;

The structural unit (A-1) is preferably represented by the following formula (1-1), more preferably represented by formula (1-2).

In formula (1-1), R ¹ and R ³ are the same as the symbols in formula (1), and R ^2-2 is a divalent aliphatic having 2 to 4 carbon atoms which may have an ether bond. Indicates a saturated hydrocarbon group.

In formula (1-2), R ¹ and R ³ have the same meanings as the symbols in formula (1).

In one embodiment of the present invention, the structural unit (A-1) is preferably represented by the following formula (1-3).

In formula (1-3), R ¹ , R ² and n are the same as the symbols in formula (1), and R ² is a divalent fatty acid having 2 to 4 carbon atoms which may have an ether bond. A group saturated hydrocarbon group is more preferable, an ethylene group is more preferable, and n is preferably 1. R ^3-2 represents an isocyanato group blocking agent R ³ —H or a residue of a salt thereof, and R ^3-2 is

or

indicate.

The structural unit (A-1) is a structural unit derived from a monomer obtained by blocking the isocyanate monomer (a-1-1) with a blocking agent (a-1-2) (hereinafter also referred to as "blocked isocyanate compound"). Preferably.

The isocyanate monomer (a-1-1) is preferably represented by the following formula (5).

(CH ₂ =CR ¹ --C(=O)O) _n --R ² --NCO (5)
In formula (5), R ¹ , R ² and n have the same meanings as the symbols in formula (1).

Examples of the isocyanate monomer (a-1-1) represented by formula (5) include, for example, a (meth)acrylic acid ester compound having an isocyanato group, and a 1:1 (mole ratio).

(Meth)acrylic acid ester compounds having an isocyanato group include, for example, 2-(meth)acryloyloxyethyl isocyanate, 3-(meth)acryloyloxy-n-propyl isocyanate, 2-(meth)acryloyloxyisopropyl isocyanate, 4 -(meth)acryloyloxy-n-butyl isocyanate, 2-(meth)acryloyloxy-tert-butyl isocyanate, 2-(meth)acryloyloxybutyl-4-isocyanate, 2-(meth)acryloyloxybutyl-3-isocyanate , 2-(meth) acryloyloxybutyl-2-isocyanate, 2-(meth) acryloyloxybutyl-1-isocyanate, 5-(meth) acryloyloxy-n-pentyl isocyanate, 6-(meth) acryloyloxy-n- hexyl isocyanate, 7-(meth)acryloyloxy-n-heptyl isocyanate, 2-(isocyanatoethyloxy)ethyl (meth)acrylate, 3-(meth)acryloyloxyphenyl isocyanate, 4-(meth)acryloyloxyphenyl isocyanate, 1,1-bis((meth)acryloyloxymethyl)methyl isocyanate and 1,1-bis(meth)acryloyloxymethyl)ethyl isocyanate.

Examples of hydroxyl group-containing (meth)acrylates include 2-hydroxyalkyl (meth)acrylates. The alkyl group of 2-hydroxyalkyl (meth)acrylate is preferably an ethyl group or an n-propyl group, more preferably an ethyl group.

Examples of diisocyanate compounds 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, lysine diisocyanate and the like.

Among these, from the viewpoint of ease of production and / or availability of raw materials, the isocyanate monomer (a-1-1) is 2-(meth)acryloyloxyethyl isocyanate, 2-(isocyanatoethyloxy)ethyl (meth ) acrylate, or 1,1-bis((meth)acryloyloxymethyl)ethyl isocyanate, more preferably 2-(meth)acryloyloxyethyl isocyanate.

Blocking agent (a-1-2) is represented by R ³ —H and includes salts thereof. Also, the blocking agent (a-1-2) contains an aromatic ring. Aromatic rings include cyclic structures possessed by polycyclic aromatic hydrocarbons. Examples of aromatic rings include condensed benzene, furan, thiophene, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxadiazole, triazole, imidazole, pyrazole, and thiazole rings. monocyclic aromatic ring; naphthalene ring, azulene ring, anthracene ring, phenanthrene ring, pyrene ring, chrysene ring, naphthacene ring, triphenylene ring, acenaphthene ring, coronene ring, fluorene ring, fluoranthene ring, pentacene ring, perylene ring , pentaphen ring, picene ring, pyranthrene ring, anthraantrene ring, quinoline ring, isoquinoline ring, quinoxaline ring, benzimidazole ring, indole ring, benzothiazole ring, benzoxazole ring, quinazoline ring, phthalazine ring, carbazole ring, carboline ring cyclic structures possessed by condensed polycyclic aromatic hydrocarbons such as Among these, a monocyclic aromatic ring is preferable, and a benzene ring and a pyrazole ring are more preferable. It is presumed that the aromatic ring of the blocking agent improves the polymerization stability of the copolymer emulsion by π-π stacking with the aromatic ring of the structural unit (A-2) described later.

Specific compounds of blocking agents include, for example, phenol, cresol, isopropylphenol, t-butylphenol, t-octylphenol, thymol, naphthol, nitrophenol, chlorophenol, fluorophenol, methyl-hydroxybenzoate, dimethylpyrazole, dimethylphenol. , ethylphenol, nonylphenol, dinonylphenol, styrenated phenol, methyl hydroxybenzoate, and thymol. Among these, ethylphenol, o-isopropylphenol, p-tert-butylphenol, p-tert-octylphenol, thymol, naphthol, p-nitrophenol, chlorophenol, fluorophenol, methyl-o-hydroxybenzoate, methyl-p-hydroxy Benzoate, 3,5-dimethylpyrazole and 3,5-dimethylphenol are preferred, and methyl-o-hydroxybenzoate, methyl-p-hydroxybenzoate and 3,5-dimethylpyrazole are more preferred.

Salts of R ³ —H include, for example, salts of metals of groups 1, 2 and 13 of the periodic table. Among these, the salt of R ³ —H is preferably a salt of sodium, potassium, magnesium, calcium or aluminum, more preferably a salt of sodium or aluminum.

A blocked isocyanate compound can be produced by a known method. For example, the isocyanate monomer (a-1-1) and the blocking agent (a-1-2) are reacted in a reaction vessel as in the following methods (i) to (iii). can be done.

(i) A method in which the blocking agent (a-1-2) is charged into a reactor and the isocyanate monomer (a-1-1) is added and reacted under stirring (ii) The isocyanate monomer (a-1) is placed in the reactor -1) is charged, and the blocking agent (a-1-2) is added and reacted while stirring (iii) The blocking agent (a-1-2) and the isocyanate monomer (a-) are placed in a reactor while stirring. 1-1) A method of adding and reacting both at the same time

The reaction temperature is not particularly limited and can be appropriately set depending on the type and amount ratio of the isocyanate monomer (a-1-1) and the blocking agent (a-1-2). is preferred, and 5°C or higher and 70°C or lower is more preferred. The reaction time is not particularly limited and can be set as appropriate, but is preferably 30 minutes or more and 168 hours or less.

In addition, a commercially available blocked isocyanate compound can also be used. Commercially available products include, for example, Showa Denko Co., Ltd. Karenz (registered trademark) MOI-BP, Karenz (registered trademark) AOI-BP, Karenz (registered trademark) MOI-SM, Karenz (registered trademark) AOI-SM, Karenz ( ® MOI-AM and Karenz® AOI-AM.

The structural unit (A-1) may be of one type alone, or may be a combination of two or more types.

The content of the structural unit (A-1) when the total of the structural units (A-1) to (A-4) (hereinafter referred to as "all structural units") of the copolymer (A) is 100 mol% is 0.1 mol % or more, preferably 0.5 mol % or more, more preferably 2 mol % or more, and is 40 mol % or less, preferably 20 mol % or less, more preferably 10 mol % or less.

[Constituent unit (A-2)]
The structural unit (A-2) having an aromatic hydrocarbon group contained in the copolymer (A) is preferably represented by the following formula (2).

In formula (2), R ⁴ is a hydrogen atom, a linear or branched saturated aliphatic hydrocarbon group having 1 to 4 carbon atoms, or an optionally substituted aromatic hydrocarbon group having 6 to 20 carbon atoms. Indicates a hydrogen group.

R ⁵ represents a C 0-8, preferably C 0-4 divalent aliphatic saturated hydrocarbon group which may have an ester bond and/or an ether bond, and via an ether bond (meth) A divalent saturated aliphatic hydrocarbon group having 0 to 4 carbon atoms bonded to an acryl group is more preferable, and 0 carbon atoms is even more preferable.

R ⁶ is a thiol group, a sulfo group, a nitro group, an amino group, a chlorine atom, a fluorine atom, a bromine atom, an iodine atom, an astatine atom, a hydroxy group, or a straight or branched chain having 1 to 4 carbon atoms in which the hydrogen atom is a fatty group; a saturated hydrocarbon group, a carboxy group, an alkoxy group having 1 to 4 carbon atoms, a carboxyester group having 1 to 4 carbon atoms in the ester moiety, or a carbonyl group having 0 to 4 carbon atoms, which may be substituted by a It represents an aromatic hydrocarbon group having 6 to 20 carbon atoms, preferably 6 to 10 carbon atoms. The above aromatic hydrocarbon group includes a cyclic structure possessed by a polycyclic aromatic hydrocarbon. ^R6 is a phenyl group, tolyl group, xylyl group, phenylethyl group, phenylpropyl group, furyl group, benzofuryl group, isobenzofuryl group, pyrrole group, indolyl group, isoindolyl group, thienyl group, benzothienyl group, imidazolyl group; , benzimidazolyl, pryl, pyrazolyl, indazolyl, oxazolyl, naphthyl, anthryl, pyridyl, quinolyl, isoquinolyl, pyrazyl, quinoxalyl, acridyl, pyrimidyl, quinazolyl, pyridazyl, cinnolyl group, phthalazyl group, triazyl group, and more preferably phenyl group.

The structural unit (A-2) is preferably a structural unit derived from the monomer (a-2) having an aromatic hydrocarbon group. Monomer (a-2) is styrene, α-methylstyrene, o-methylstyrene, 2-isopropenyltoluene, m-methylstyrene, 3-isopropenyltoluene, p-methylstyrene, 4-isopropenyltoluene, Ethylstyrene, t-butylstyrene, t-butyl-α-methylstyrene, dimethylstyrene, methoxystyrene, vinylbenzoic acid, methyl vinylbenzoate, vinylbenzylacetate, hydroxystyrene, allylbenzene, isopropenylpropylbenzene, isopropenylbutyl Benzene, isopropenylpentylbenzene, isopropenylhexylbenzene, isopropenyloctylbenzene, vinylnaphthalene, vinylanthracene, 1,1-diphenylethylene, vinylfuran, vinylbenzofuran, vinylisobenzofuran, vinylpyrrole, vinylindole, vinylisoindole, Vinylthiophene, vinylbenzothiophene, vinylimidazole, vinylbenzimidazole, vinylpurine, vinylpyrazole, vinylindazole, vinylpyridine, vinylpyrazine, vinylquinoline, vinylpyrimidine, vinylquinazoline, benzyl (meth)acrylate, (meth)acrylic acid methyl benzyl ester of (meth) acrylic acid ethyl benzyl ester, (meth) acrylic acid propyl benzyl ester, 2-phenoxymethyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, (meth) acrylic acid 2-Phenoxypropyl and those in which the hydrogen atoms are substituted with halogen atoms are preferred, and styrene, α-methylstyrene, α-methylstyrene, 2-Phenoxyethyl (meth)acrylate and those in which hydrogen atoms are substituted with halogen atoms are more preferred.

The structural unit (A-2) may be of one type alone, or may be a combination of two or more types.

The content of the structural unit (A-2) when the total of all structural units of the copolymer (A) is 100 mol% is 1.0 mol% or more, preferably 3.0 mol% or more, more preferably is 20.0 mol % or more and 99.5 mol % or less, preferably 70.0 mol % or less, more preferably 50.0 mol % or less.

In one embodiment of the present invention, the structural unit (A-2) is preferably represented by the following formula (10).

In formula (10), R ¹⁴ represents a hydrogen atom or a methyl group, R ¹⁵ represents an alkylene group having 1 to 4 carbon atoms, preferably 1 to 2 carbon atoms, and X represents an aromatic group.

The aromatic group for X is not particularly limited, and the hydrogen atom of the aromatic group may be substituted. The aromatic group is preferably an aromatic group having a benzene ring, naphthalene ring or anthracene ring structure, more preferably a benzene ring structure, still more preferably an unsubstituted benzene ring structure.

The structural unit represented by the above formula (10) is preferably a structural unit derived from the monomer (a-2-2). Examples of the monomer (a-2-2) include benzyl acrylate, benzyl methacrylate, 9-anthrylmethyl methacrylate and the like.

By containing the compound represented by the formula (10), the stability of the blocked isocyanate compound is improved, and functional groups having active hydrogen such as carboxy groups, hydroxyl groups and amino groups are contained in the same copolymer (A). , the isocyanato group blocked with the blocking agent can be stably present during polymerization and storage.

[Constituent unit (A-3)]
The copolymer (A) preferably contains the structural unit (A-3). The structural unit (A-3) is represented by the following formula (3).

In formula (3), R ⁷ represents a hydrogen atom or a linear or branched C 1-4 aliphatic saturated hydrocarbon group. ^R8 is a hydrogen atom substituted with a hydroxy group, an acyl group, an alkoxy group, a carboxy group, a thiol group, a sulfo group, a nitro group, an amino group, a chlorine atom, a fluorine atom, a bromine atom, an iodine atom, or an astatine atom; C 1-18 aliphatic saturated hydrocarbon group with no aromatic ring.

Structural unit (A-3) is not included in structural units (A-1) and (A-2).

The structural unit (A-3) is preferably a structural unit derived from the monomer (a-3). Monomer (a-3) is preferably an ester compound formed by carboxylic acid compound (a-3-1) and R ⁸ --OH (a-3-2).

(Meth)acrylic acid is preferred as the carboxylic acid compound (a-3-1).
In R ⁸ -OH(a-3-2), R ⁸ has the same meaning as the code in formula (3). R ⁸ is a methyl group, ethyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n-propyl group, i-propyl group, 2-ethylhexyl group, n-dodecyl group or the like; and preferred are methyl group, ethyl group, butyl group, propyl group and 2-ethylhexyl group.

Examples of the monomer (a-3) include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. is mentioned.

The structural unit (A-3) may be of one type alone, or may be a combination of two or more types.

The content of the structural unit (A-3) when the total of all structural units of the copolymer (A) is 100 mol% is 0 mol% or more, preferably 3.0 mol% or more, more preferably 10 0 mol % or more and 94.5 mol % or less, preferably 70.0 mol % or less, more preferably 50.0 mol % or less.

[Structural unit (A-4)]
The copolymer (A) preferably contains the structural unit (A-4). The structural unit (A-4) is represented by the following formula (4-1) or (4-2).

In formula (4-1), R ⁹ , R ¹⁰ and R ¹¹ each independently have a hydrogen atom or an ester bond and/or a carbon number of 1 to 15 optionally containing a carboxy group, preferably a carbon number of 1 to 6. indicates a straight or branched hydrocarbon group.

In formula (4-2), R ¹² represents a hydrogen atom or a saturated aliphatic hydrocarbon group having 1 to 4 carbon atoms including a linear or branched chain having 1 to 4 carbon atoms, and R ¹³ represents an ester bond and / or a divalent saturated aliphatic hydrocarbon group having 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms, or a saturated aliphatic hydrocarbon group having 6 to 20 carbon atoms, preferably 6 to 10 carbon atoms, which may have a carbonyl group Indicates an aromatic hydrocarbon group.

Structural unit (A-4) represented by formula (4-1) is preferably a structural unit derived from monomer (a-4-1). Examples of the monomer (a-4-1) include unsaturated monocarboxylic acids such as (meth)acrylic acid, crotonic acid, 2-pentenoic acid and cinnamic acid; unsaturated monocarboxylic acids such as fumaric acid, maleic acid and itaconic acid; Saturated dicarboxylic acids; butenedioic acid mono-chain alkyl esters such as monomethyl fumarate, monoethyl fumarate, mono-n-butyl fumarate, monomethyl maleate, monoethyl maleate, mono-2-ethylhexyl maleate, and mono-n-butyl maleate; butenedioic acid monocyclic alkyl esters such as monocyclopentyl fumarate, monocyclohexyl fumarate, monocyclopentyl maleate and monocyclohexyl maleate; itacones such as monomethyl itaconate, monoethyl itaconate, mono-n-butyl itaconate and monocyclohexyl itaconate and acid monoesters. Among these, unsaturated dicarboxylic acid monoesters such as (meth)acrylic acid, monoethyl fumarate, monopropyl fumarate, monobutyl fumarate, monoethyl itaconate, monopropyl itaconate, and monobutyl itaconate are preferable, and (meth) acrylic Acids are more preferred.

The structural unit (A-4) represented by formula (4-2) is preferably a structural unit derived from the monomer (a-4-2). Examples of the monomer (a-4-2) include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 3-hydroxyphenyl (meth)acrylate. , 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, mono-2-((meth)acryloyloxy)ethylsuccinic acid and the like. Among these, 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate are preferred, and 2-hydroxyethyl (meth)acrylate is more preferred.

The structural unit (A-4) may be of one type alone, or may be a combination of two or more types.

The content of the structural unit (A-4) when the total of all structural units of the copolymer (A) is 100 mol% is 0 mol% or more, preferably 0.1 mol% or more, more preferably 0 .3 mol % or more and 20 mol % or less, preferably 15.0 mol % or less, more preferably 5.0 mol % or less.

[Method for producing copolymer emulsion]
The copolymer emulsion which is one embodiment of the present invention can be produced, for example, by mixing the monomer (a-1) and the monomer (a-2) with water, or after polymerization in an organic solvent. , emulsifying by adding a surfactant and water, and distilling off the solvent, but it is preferably produced by emulsion polymerization. A copolymer emulsion can be produced by emulsion polymerization by a known method. For example, a monomer emulsion is prepared in advance by emulsifying and dispersing a monomer and water, preferably using a surfactant, and then water, preferably water and a surfactant are mixed in a vessel different from the monomer emulsion. After raising the temperature of the mixture, the previously prepared monomer emulsion is added dropwise to the mixture, preferably a radical polymerization initiator is appropriately added, and the mixture can be produced by emulsion polymerization. The reaction temperature and reaction time can be appropriately set according to the type and amount of the monomers used.

The monomer (a-3) and/or the monomer (a-4) may be used during the production of the copolymer emulsion.

Monomer (a-1) and monomer (a-2) used in the production of copolymer emulsion, and monomer (a-3) and monomer (a-4) preferably used The amount of the monomer (a-1) is 0.1 mol% or more, preferably 0.5 mol% or more, more preferably 2 mol% or more when the total of these monomers is 100 mol%. and is 40 mol % or less, preferably 20 mol % or less, more preferably 10 mol % or less.

The content of the monomer (a-2) is 1.0 mol% or more, preferably 3.0 mol% or more, more preferably 20.0 mol% or more when the total amount of the monomer is 100 mol%. and is 99.5 mol % or less, preferably 70.0 mol % or less, more preferably 50.0 mol % or less.

The content of the monomer (a-3) is 0 mol% or more, preferably 3.0 mol% or more, and more preferably 10.0 mol% or more when the total amount of the monomers is 100 mol%. , 94.5 mol % or less, preferably 70.0 mol % or less, more preferably 50.0 mol % or less.

The content of the monomer (a-4) is 0 mol% or more, preferably 0.1 mol% or more, and more preferably 0.3 mol% or more when the total amount of the monomers is 100 mol%. , 20 mol % or less, preferably 15.0 mol % or less, more preferably 5.0 mol % or less.

The blending amount of each of the above monomers is substantially the same as the content of each structural unit when the total of all structural units in the copolymer (A) is 100 mol%.

The solvent for the copolymer emulsion is water. The solvent may contain a solvent that is compatible with water, and the content thereof is 20% by mass or less, preferably 10% by mass or less, more preferably 5% by mass or less, based on the total solvent. Solvents compatible with water include, for example, alcohols such as methanol, ethanol and isopropanol; ethers such as ethylene glycol monomethyl ether and propylene glycol monoethyl ether; and ketones such as acetone and methyl ethyl ketone.

The copolymer emulsion is preferably produced in the presence of surfactant (C), chain transfer agent (D) and polymerization initiator (E).

[Surfactant (C)]
The copolymer emulsion is preferably produced in the presence of a surfactant (C). The surfactant is not particularly limited, but one or more of commonly used nonionic emulsifiers, anionic emulsifiers or reactive surfactants can be used. Surfactant (C) is preferably an anionic emulsifier or a reactive surfactant, and more preferably a reactive surfactant for suppressing bleeding out of the surfactant onto the surface after drying the copolymer emulsion.

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, and polyoxyethylene fatty acid esters. and polyoxyethylene sorbitan fatty acid esters.

Examples of anionic emulsifiers include alkylbenzene sulfonates, alkyl sulfates, polyoxyethylene alkyl ether sulfates, polyoxyalkylene alkyl ether phosphates or their salts, polyoxyalkylene alkylphenyl ether phosphates or their salts. Salts, fatty acid salts and the like can be mentioned, and examples of salts include alkali metals such as sodium and potassium, ammonia, amines and the like.

Examples of reactive surfactants include structures such as the following formulas (6) to (8).

In formulas (6) to (8), R ²¹ , R ²³ , R ²⁴ and R ²⁵ each independently represent hydrogen or an alkyl group, R ²² represents an alkyl group, an alkylphenyl group, or the like, and A is —CH an alkylene group such as ₂ -- _CH.sub.2-- ; M is an ammonium salt or a metal salt such as potassium or sodium; n is an integer of 2-20;

Examples of compounds represented by formula (6) include Aqualon (registered trademark) KH-10 and KH-5 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). Examples of the compound represented by formula (7) include Adekari Soap (registered trademark) SE-10N (manufactured by ADEKA Corporation) and the like. Examples of the compound represented by formula (8) include Aqualon (registered trademark) HS-10 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.).

The surfactant (C) can ensure the stability of the particles during polymerization and can suppress the increase in viscosity, so that it is contained in an amount of 0.1% or more and 10% or less based on the solid content of the copolymer (A). It is preferably contained in an amount of 0.3% or more and 7% or less, and further preferably 0.5% or more and 5% or less.

[Chain transfer agent (D)]
A chain transfer agent (D) can be used as needed to adjust the molecular weight of the copolymer (A). The chain transfer agent (D) is not particularly limited, but alkyl mercaptans such as n-hexylmercaptan, n-octylmercaptan, t-octylmercaptan, n-dodecylmercaptan, t-dodecylmercaptan, and n-stearylmercaptan; -xanthogen compounds such as diphenyl-4-methyl-1-pentene, 2,4-diphenyl-4-methyl-2-pentene, dimethylxanthogen disulfide, diisopropyl xanthogen disulfide; terpinolene, tetramethylthiuram disulfide, tetraethylthiuram disulfide, Thiuram compounds such as tetramethylthiuram monosulfide; Phenolic compounds such as 2,6-di-t-butyl-4-methylphenol and styrenated phenol; Allyl compounds such as allyl alcohol; Dichloromethane, dibromomethane, tetrabromide halogenated hydrocarbon compounds such as carbon; vinyl ethers such as α-benzyloxystyrene, α-benzyloxyacrylonitrile, α-benzyloxyacrylamide; triphenylethane, pentaphenylethane, acrolein, methacrolein, thioglycolic acid, thiomalic acid, and 2-ethylhexyl thioglycolate. You may use 1 type(s) or 2 or more types of these. Although the amount of these chain transfer agents to be used is not particularly limited, it is usually used in an amount of 0 to 5% based on the solid content of the copolymer (A).

[Polymerization initiator (E)]
The copolymer emulsion is preferably produced in the presence of the polymerization initiator (E). Also, a polymerization initiator and a reducing agent may be used in combination as a redox polymerization initiator. Potassium hydrogen sulfite, sodium bisulfite, potassium sulfite, sodium sulfite and the like can be used as the reducing agent.

The polymerization initiator (E) is not particularly limited, but 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) oxy) n-butyl valerate, 2,2-di(t-butylperoxy)butane, t-butyl hydroperoxide, cumene hydroperoxide, 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 oxide, benzoyl(3-methylbenzoyl)peroxide, diisopropylperoxydicarbonate, di-n-propylperoxydicarbonate, di(4-t-butylcyclohexyl)peroxydicarbonate, di(2-ethylhexyl)peroxy dicarbonate, di-sec-butylperoxydicarbonate, cumyl peroxyneodecanate, 1,1,3,3-tetramethylbutylperoxyneodecanate, t-hexylperoxyneodecanate, t-butylperoxy oxyneodecanate, t-hexylperoxypivalate, t-butylperoxypivalate, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, 1,1,3,3 -tetramethyl butyl peroxy-2-ethylhexanate, t-hexyl peroxy-2-ethylhexanate, t-butyl peroxy-2-ethyl hexanate, t-butyl peroxylaurate, t-butyl peroxy -3,5,5-trimethylhexanate, t-hexylperoxyisopropyl monocarbonate, t-butylperoxyisopropylmonocarbonate, t-butylperoxy-2-ethylhexylmonocarbonate, 2,5-dimethyl-2,5- Di(benzoylperoxy)hexane, t-butylperoxyacetate, t-hexylperoxybenzoate, t-butylperoxybenzoate, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, etc. Organic peroxide-based polymerization initiator; hydroperoxide, azobisisobutyronitrile, 2,2'-azobis(isobutyrate)dimethyl, 4-4'-azobis(4-cyanovaleric acid), 2-2 '-Azobis[2-(2-imidazolin-2-yl)propane, 2-2'-azobis(propane-2-carbamidine) 2-2'-azobis[N-(2-carboxyethyl)-2-methyl Propanamide, 2-2′-azobis{2-[1-(2-hydroxyethyl)-2-imidazolin-2-yl]propane}, 2-2′-azobis(1-imino-1-pyrrolidino-2- methyl propane) and azo initiators such as 2-2′-azobis{2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propanamide}. These polymerization initiators may be used singly or in combination of two or more. Polymerization initiator (E) is potassium persulfate, sodium persulfate, ammonium persulfate, t-butyl hydroperoxide, cumene hydroperoxide, benzoyl peroxide, hydroperoxide, azobisisobutyronitrile, 2,2' -Dimethyl azobis(isobutyrate) is preferable, and potassium persulfate, sodium persulfate and ammonium persulfate are more preferable because of their good solubility in water.

The polymerization initiator (E) is preferably contained in an amount of 0.01% or more and 5% or less, more preferably 0.03% or more and 4% or less, relative to the solid content of the copolymer (A). More preferably, the content is 05% or more and 3% or less. If the polymerization initiator (E) is within the above range, the amount of residual monomers after the reaction can be reduced, and the influence of physical properties due to the structure derived from the polymerization initiator can be suppressed, which is preferable.

In one embodiment of the present invention, the copolymer emulsion preferably contains a basic salt containing an acid with a pKa of 2 or more and an alkali metal. By containing a basic salt containing an acid having a pKa of 2 or more and an alkali metal, the tensile strength (Tb) of the cured resin film is improved, which is preferable.

Examples of acids with a pKa of 2 or more include carbonic acid, acetic acid, nitrous acid, sulfurous acid, phosphoric acid, and boric acid.

Alkali metals are preferably lithium, sodium, potassium, rubidium, and cesium, more preferably sodium and potassium.

Basic salts containing an acid having a pKa of 2 or more and an alkali metal include lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, cesium carbonate, lithium bicarbonate, sodium bicarbonate, potassium bicarbonate, rubidium bicarbonate, Cesium bicarbonate, sodium acetate, potassium acetate, sodium nitrite, potassium nitrite, sodium sulfite, potassium sulfite, disodium hydrogen phosphate, trisodium phosphate, dipotassium hydrogen phosphate, tripotassium phosphate, lithium borate, boron sodium borate, potassium borate, rubidium borate, cesium borate, sodium octaborate, potassium tetraborate and the like. Borate salts such as lithium borate include polyborate salts such as lithium polyborate.

By containing a basic salt containing an acid having a pKa of 2 or more and an alkali metal, it has an isocyanato group dissociated from the block isocyanate and an active hydrogen group (carboxy group, hydroxyl group, etc.) reactive with the isocyanate group, for example. It is preferable because it rapidly reacts with the functional group. The basic salt containing an acid having a pKa of 2 or more and an alkali metal is preferably contained at 0.2% or more and 7.5% or less with respect to the solid content of the copolymer (A), and 0.3% It is more preferable that the content is 5.0% or less, and more preferably 0.5 or more and 3.0% or less.

The basic salt containing an acid having a pKa of 2 or more and an alkali metal can be confirmed by dissolving the cured resin film (F) described later in a solvent and measuring its pH to confirm that it is basic.

The copolymer emulsion may contain one or more antifoaming agents, fillers, leveling agents and solvents.

<One-component thermosetting resin composition>
One embodiment of the present invention is a one-component thermosetting resin composition containing the above copolymer emulsion. The one-component thermosetting resin composition may contain pigments, dyes, anti-aging agents, thickeners, fillers, and the like, if necessary. A one-component thermosetting resin composition can be suitably used as a paint.

<Resin cured film (F)>
One embodiment of the present invention is a cured resin film (F) obtained by curing the one-component thermosetting resin composition. The cured resin film (F) can be obtained by thermally curing a one-component thermosetting resin composition by a known method. It is considered that the cured resin film (F) is easily formed by cross-linking the carboxylic acid or hydroxy groups derived from the structural unit (A-4) within the copolymer (A) or between the copolymers (A). The temperature during heat curing is 110° C. or higher, preferably 115° C. or higher, and lower than 130° C., preferably 125° C. or lower.

The cured resin film (F) can be suitably used, for example, as a coating film (G), a coating agent and an adhesive.

<Two-component thermosetting resin composition>
One embodiment of the present invention is a two-component thermosetting resin composition containing the above copolymer emulsion and an acrylic polyol polymer emulsion (J) described below. The copolymer emulsion and the acrylic polyol polymer emulsion (J) are prepared separately and then mixed for use, or stored in separate containers until use. A two-component thermosetting resin composition can be suitably used as a paint.

[Acrylic polyol polymer emulsion (J)]
As the acrylic polyol polymer emulsion (J), known ones can be used without limitation, but an emulsion containing an acrylic polyol polymer represented by the following formula (9) is preferable.

In formula (9), R ³¹ and R ³³ each independently represent a hydrogen atom or a linear or branched C 1-6, preferably C 1-4 saturated aliphatic hydrocarbon group. R ³² is a C 1-20, preferably C 1-8 divalent aliphatic saturated hydrocarbon group optionally having an ester bond and/or a carbonyl group, or a C 6-20, preferably C 2 Numbers 6 to 10 represent aromatic hydrocarbon groups. R ³⁴ represents a hydrocarbon having 1 to 20 carbon atoms, preferably 1 to 8 carbon atoms. Further, m represents an integer of 1 or more, and p represents 0 or an integer of 1 or more.

The acrylic polyol polymer emulsion (J) is, for example, a mixture containing a hydroxyl group-containing polymerizable unsaturated monomer and another polymerizable unsaturated monomer copolymerizable with the hydroxyl group-containing polymerizable unsaturated monomer. can be obtained by copolymerization by known methods such as bulk polymerization, solution polymerization in an organic solvent, and emulsion polymerization in water.

Examples of hydroxyl group-containing polymerizable unsaturated monomers include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 3-hydroxyphenyl (meth) acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, mono-2-((meth)acryloyloxy)ethylsuccinic acid, polyethylene glycol mono(meth)acrylate, polypropylene glycol (meth)acrylate, etc.) Examples thereof include monoesterified products of alcohol and (meth)acrylic acid, compounds obtained by ring-opening polymerization of ε-caprolactone in monoesterified products of polyhydric alcohol and (meth)acrylic acid, and the like. More than one species can be used in combination. Among these, 2-hydroxyethyl (meth)acrylate can be preferably used.

Other copolymerizable polymerizable unsaturated monomers include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) Acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl acrylate, cyclohexyl (meth)acrylate, n-octyl (meth)acrylate, lauryl (meth)acrylate, isobornyl (meth)acrylate, stearyl (meth)acrylate ) alkyl esters of (meth)acrylic acid such as acrylate; carboxyl group-containing polymerizable unsaturated monomers such as (meth)acrylic acid, maleic acid and maleic anhydride; N,N-dimethylaminoethyl (meth)acrylate, N, N-diethylaminoethyl (meth)acrylate, aminoalkyl (meth)acrylates such as N,N-dimethylaminopropyl (meth)acrylate; acrylamide, methacrylamide, N,N-dimethylaminoethyl (meth)acrylamide, N,N- (Meth)acrylamides such as diethylaminoethyl (meth)acrylamide, N,N-dimethylaminopropyl (meth)acrylamide, N-methylolacrylamide, N-methylolacrylamide methyl ether, N-methylolacrylamide butyl ether or derivatives thereof; 2-(methacryloyl oxy)ethyltrimethylammonium chloride, 2-(methacryloyloxy)ethyltrimethylammonium bromide, and the like; quaternary ammonium group-containing monomers; sulfoalkyl (meth)acrylates such as sulfoethyl (meth)acrylate; acrylonitrile, methacrylonitrile, vinyl acetate, styrene, vinyltoluene, α-methylstyrene; polyvinyl compounds such as allyl methacrylate; γ-(meth)acryloyloxypropyltri Examples include hydrolyzable silyl group-containing polymerizable unsaturated monomers such as methoxysilane, γ-(meth)acryloyloxypropyltriethoxysilane, γ-(meth)acryloyloxypropylmethyldimethoxysilane, and the like. These can be used alone or in combination of two or more. Among these, (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, Tert-butyl (meth)acrylate, 2-ethylhexyl acrylate, cyclohexyl (meth)acrylate can be preferably used.

The mixing ratio of the acrylic polyol polymer emulsion (J) and the copolymer emulsion is (the number of moles of hydroxyl groups in the acrylic polyol polymer emulsion (J)): (the number of structural units (A-1) in the copolymer emulsion). number of moles) is preferably 10:1 to 1:10, more preferably 5:1 to 1:5, even more preferably 1.5:1 to 1:1.5.

The two-component thermosetting resin composition may contain pigments, dyes, anti-aging agents, thickeners, fillers, film-forming aids, etc., if necessary.

<Resin cured film (M)>
One embodiment of the present invention is a cured resin film (M) obtained by curing the two-component thermosetting resin composition. The cured resin film (M) can be obtained by mixing the prepared copolymer emulsion and the acrylic polyol polymer emulsion (J), followed by thermal curing by a known method. The temperature during heat curing is 110° C. or higher, preferably 115° C. or higher, and lower than 130° C., preferably 125° C. or lower. The cured resin film (M) is considered to be formed by cross-linking the structural unit (A-2) in the copolymer emulsion and the acrylic polyol polymer in the acrylic polyol polymer emulsion (J).

The cured resin film (M) of this embodiment can be suitably used, for example, as a coating film (N), a coating agent, or an adhesive.

The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[Evaluation of solid content]
The solid content in the copolymer emulsion was measured by accurately weighing the copolymer emulsion on an aluminum dish and then heat-treating (141°C for 30 minutes) to dry the solid content. Calculated from the difference in mass.

[Measurement of molecular weight]
The number-average molecular weight (Mn) and weight-average molecular weight (Mw) of the copolymer in the copolymer emulsion were measured by GPC by adding 1.5 mL of THF to about 0.1 g of the copolymer emulsion and dissolving it by hand mixing. (Gel Permeation Chromatography Method) and converted into polystyrene for calculation.

[Evaluation of membrane tensile strength (Tb), elongation at break (Eb), modulus at 300% elongation (M300), and modulus at 500% elongation (M500)]
After the dried resin film or cured resin film obtained in Examples or Comparative Examples was peeled off from the glass substrate, it was cut into a No. 8 dumbbell shape. Each cut film was subjected to a tensile test using a tensile compression tester (Autograph AGS-500NX, manufactured by Shimadzu Corporation; tensile speed: 50 mm/min, temperature: 23°C). A tensile test was performed according to JIS-K7127-1999. By this test, modulus at 300% elongation (M300), modulus at 500% elongation (M500), tensile strength (Tb) and elongation at break (Eb) at room temperature were measured. Differences (ΔTb, ΔEb, ΔM300, ΔM500) were calculated by subtracting each measured value of the dried resin film from each measured value of the cured resin film.

[Stability test]
The molecular weights of the copolymer emulsions immediately after preparation and after storage at 40° C. for 1 week, 2 weeks and 4 weeks were measured by the measurement method described above.
Also, the tensile strength (Tb), elongation at break (Eb), modulus at 300% elongation ( M300) and modulus at 500% elongation (M500) were measured by the above measuring method.

[Reagent used]
The abbreviations of the compounds used in Examples and Comparative Examples are shown below.
[Structural unit (A-1)]
AOI-BP: 2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl acrylate (manufactured by Showa Denko KK)
MOI-SM: 2-[(methyl-o-hydroxybenzolyl)carbonylamino]ethyl methacrylate (manufactured by Showa Denko KK)
[Constituent unit (A-2)]
St: Styrene (manufactured by Kanto Chemical Co., Ltd.)
PhOEA: 2-phenoxyethyl acrylate (manufactured by Kanto Chemical Co., Ltd.)
p-MeSt: paramethylstyrene (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.)
BnMA: benzyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.)
[Constituent unit (A-3)]
BuA: butyl acrylate (manufactured by Kanto Chemical Co., Ltd.)
MMA: methyl methacrylate (manufactured by Kanto Chemical Co., Ltd.)
HEMA: 2-hydroxyethyl methacrylate (manufactured by Kanto Chemical Co., Ltd.)
[Structural unit (A-4)]
Aa: acrylic acid (manufactured by Kanto Chemical Co., Ltd.)
[Other ingredients]
MPACEM: 2-[0-(1′-methylpropylideneamino)carboxyamino]ethyl methacrylate (manufactured by Showa Denko KK)
NaSS: sodium styrene sulfonate (manufactured by Tokyo Chemical Industry Co., Ltd.)
[Surfactant]
KH-10: Aqualon (registered trademark) KH-10 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
AR-10: Aqualon (registered trademark) AR-10 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
G-15: Neopelex G-15 (16% sodium dodecibenzenesulfonate (soft type) aqueous solution) (manufactured by Kao Corporation)
E-34K: Handis E-34K (34% disproportionated tall rosin acid soap) (manufactured by Harima Kasei Co., Ltd.)
[Chain transfer agent]
OTG: 2-ethylhexyl thioglycolate (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.)
[Polymerization initiator]
KPS: potassium persulfate (manufactured by Kanto Chemical Co., Ltd.)
[Reducing agent]
SBS: sodium bisulfite (manufactured by Kanto Chemical Co., Ltd.)

[Preparation Example 1]
An acrylic polyol polymer emulsion was prepared as follows.
120 g of deionized water was placed in a 1 L four-necked flask equipped with a stirrer, a condenser and a thermometer, and heated to 80° C. in a water bath while purging the inside of the system with nitrogen gas. In a separate 500 mL glass beaker 1.0 g sodium p-styrene sulfonate, 60 g methyl methacrylate, 90 g n-butyl acrylate, 9 g n-butyl methacrylate, 20 g 2-hydroxyethyl methacrylate, 20 g styrene, 2-ethylhexyl thioglycolate1. 6 g of deionized water, 100 g of deionized water, and 3.0 g of Aqualon (registered trademark) KH-10 were added and vigorously stirred with a stirrer tip to prepare an emulsion. After adding 30 g of the prepared emulsion to a container heated to 80° C., separately prepared catalyst solution A (potassium persulfate 0.60 g, deionized water 11.4 g) was added all at once. Thirty minutes after the addition, the rest of the emulsified liquid was added over 3 hours, and at the same time, separately prepared catalyst solution B (60 mg of potassium persulfate and 1.1 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 completion of aging, the mixture was cooled to 30° C. or lower and neutralized with aqueous ammonia to pH 7.5 or higher to obtain the desired acrylic polyol polymer emulsion. The solid content concentration was 47.0%.

[Example 1]
A two-component thermosetting resin composition and a cured resin film were prepared as follows.
35.5 g of deionized water, 0.05 g of Aqualon (registered trademark) KH-10, and 416 mg of sodium bisulfite are placed in a 500 mL four-necked flask equipped with a stirrer, condenser, and thermometer, and the system is filled with nitrogen gas. Heat to 50° C. in a water bath while purging. In a separate 300 mL glass beaker 0.50 g sodium p-styrenesulfonate, 20 g styrene, 51 g butyl acrylate, 23.5 g methyl methacrylate, 2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl acrylate (AOI-BP) 5.0 g, 0.50 g of 2-ethylhexyl thioglycolate, 57.5 g of deionized water, and 2.4 g of Aqualon (registered trademark) KH-10 were added and vigorously stirred with a stirrer tip to prepare an emulsion. After adding 4.8 g of the prepared emulsion to a container heated to 50° C., separately prepared catalyst solution A (65 mg of potassium persulfate, 1.2 g of deionized water) was added all at once. Thirty minutes after the addition, the rest of the emulsified liquid was added over 2 hours, and at the same time, separately prepared catalyst solution B (potassium persulfate 0.39 g, deionized water 7.4 g) was added over 3 hours. After the addition of catalyst solution B was completed, the mixture was further aged for 1.5 hours. After completion of aging, the mixture was cooled to 30° C. or lower and neutralized with aqueous ammonia to pH 7.5 or higher to obtain the intended copolymer emulsion. No residual monomers other than 1600 ppm of n-butyl acrylate were detected in the copolymer emulsion, confirming that the composition of the charged copolymer was substantially the same as the charged monomer composition. The solid content concentration was 46.75%.

The obtained copolymer emulsion and the acrylic polyol polymer emulsion obtained in Preparation Example 1 were mixed for 30 minutes with the film-forming composition shown in Table 1-1 to obtain a two-component thermosetting resin composition. Obtained.

The obtained two-component thermosetting resin composition was applied to a glass substrate coated with a release agent so as to have a thickness of 50±20 μm, and dried at 23° C. for 1 hour or longer to obtain a dried resin film. Also, the two-component thermosetting resin composition was applied to a thickness of 50±20 μm on a glass substrate coated with a release agent, and cured at 120° C. for 15 minutes to obtain a cured resin film.

[Preparation of Examples 2 to 14 and Comparative Examples 1 to 3]
A copolymer emulsion was prepared in the same manner as in Example 1 except that the compositions shown in Tables 1-1 to 1-3 were used. -1 to Table 1-3 were mixed for 30 minutes to obtain two-component thermosetting resin compositions of Examples 2 to 14 and Comparative Examples 1 to 3. A dried resin film and a cured resin film were obtained in the same manner as in Example 1 using each of the obtained two-component thermosetting resin compositions.

The evaluation and measurement results of Examples 1-14 and Comparative Examples 1-3 are shown in Tables 1-1 to 1-3. In addition, the same procedure as in Example 1 was performed using the molecular weight measurement results of the copolymer emulsion when the copolymer emulsion was stored at the temperature and time shown in Table 2, and the copolymer emulsion when stored. Table 2 shows the evaluation results of the dried resin film and the cured resin film obtained from the prepared two-component thermosetting resin composition.

[Examples 15 to 18, Comparative Example 4]
One-component thermosetting resin compositions of Examples 15 to 18 and Comparative Example 4 were obtained in the same manner as in Example 1, except that the composition shown in Table 3 was used and the acrylic polyol polymer emulsion was not used. A dried resin film and a cured resin film were obtained in the same manner as in Example 1 using each of the obtained one-liquid thermosetting resin compositions. Table 3 shows the evaluation and measurement results in Examples 15 to 18 and Comparative Example 4.

[Examples 19 to 22]
A copolymer emulsion having the composition shown in Table 4 was prepared in the same manner as in Example 1, and then an acid having a pKa of 2 or more and a basic salt containing an alkali metal having the composition shown in Table 4 were added, and One-component thermosetting resin compositions of Examples 19 to 22 were obtained in the same manner as in Example 1, except that the acrylic polyol polymer emulsion was not used. Each cured resin film was obtained in the same manner as in Example 1 using each of the obtained one-liquid thermosetting resin compositions. Table 4 shows each evaluation and measurement results in Examples 19 to 22.

[Examples 23 to 26]
A copolymer emulsion was prepared in the same manner as in Example 1 except that the composition shown in Table 5 was used. , and the acrylic polyol polymer emulsion obtained in Preparation Example 1 were mixed for 30 minutes according to the composition for film production shown in Table 5 to obtain two-component thermosetting resin compositions of Examples 23 to 26. . Each cured resin film was obtained in the same manner as in Example 1 using each of the obtained two-component thermosetting resin compositions. Table 5 shows each evaluation and measurement results in Examples 23 to 26.

[Examples 27-29]
One-component thermosetting resin compositions of Examples 27 to 29 were obtained in the same manner as in Example 1, except that the composition shown in Table 6 was used and the acrylic polyol polymer emulsion was not used. Each cured resin film was obtained in the same manner as in Example 1 using each of the obtained one-liquid thermosetting resin compositions. Table 6 shows each evaluation and measurement results in Examples 27 to 29.

The Tb of the cured resin film cured at 120°C for 15 minutes was 2.25 MPa or more in Examples 1 to 26.

On the other hand, when the copolymer emulsions of Comparative Examples 1 to 4 were used, they were all less than 1.85 MPa, which was smaller than that of the Examples. In Comparative Examples 1 and 4, since the copolymer emulsion did not contain the structural unit (A-2), the isocyanato group blocked by the blocking agent in the structural unit (A-1) was decomposed during polymerization, and the isocyanato group It is thought that this is because no cross-linking is formed from the

This is probably because the copolymer emulsion in Comparative Example 2 does not contain the structural unit (A-1), and thus cross-linking cannot be formed even if the structural unit (A-2) is contained. In Comparative Example 3, the copolymer emulsion contained the structural unit (A-1) even though the copolymer emulsion contained, as a structural unit, an isocyanato group blocked with a blocking agent having a higher dissociation temperature than the structural unit (A-1). Therefore, even if the structural unit (A-2) is contained, it is considered that no cross-linking is formed under mild conditions of 120° C. for 15 minutes. Therefore, it is considered that the cured resin films of Examples 1-26 have sufficient strength compared to the cured resin films of Comparative Examples 1-4.

In Examples 2 to 4, 6, 9, 10, 12 to 16, the difference (ΔTb) obtained by subtracting the Tb value of the resin dried film dried at room temperature from the Tb value of the resin cured film cured at 120 ° C. for 15 minutes. , the Tb value of the cured resin film cured at 120° C. for 15 minutes and the Tb value of the dried resin film dried at room temperature are all above the lower limit of measurement. ΔTb of Comparative Examples 1 to 4 is smaller than these. In the cured films prepared using the copolymer emulsions of Examples 2 to 4, 6, 9, 10, and 12 to 16, cross-linking did not occur even under mild conditions of 120°C for 15 minutes compared to conventional conditions. considered to be in progress.

On the other hand, when the copolymer emulsion of Comparative Example 1 was used, ΔTb was smaller than that of Examples. In Comparative Example 1, since the copolymer emulsion did not contain the structural unit (A-2), the isocyanato group blocked by the blocking agent in the structural unit (A-1) was decomposed during polymerization, and the isocyanato group This is probably because no cross-links are formed. In Comparative Examples 2 and 3, since the copolymer emulsion did not contain the structural unit (A-1), cross-linking was not formed even if the structural unit (A-2) was contained. From this, it is considered that the cured films of Examples 1 to 14 undergo cross-linking even under milder conditions than conventional conditions of 120° C. for 15 minutes.

Also, regarding the difference (ΔEb) obtained by subtracting the Eb value of the dried resin film from the Eb value of the cured resin film cured at 120°C for 15 minutes, ΔEb showed a negative value in the example. This negative change in the Eb value is considered to be due to the progress of cross-linking. In other words, when the copolymer emulsions of the examples were used, it is considered that the formation of crosslinks proceeded even under milder conditions such as 120° C. for 15 minutes compared to the conventional conditions.

The Eb of the resin cured film cured at 120 ° C. for 15 minutes is 13 to 743% in Examples 1 to 18, while the Eb value in Comparative Examples 1 to 4 exceeds the upper measurement limit of 830. rice field. A large Eb value in the cured resin film is not preferable because the shape of the cured resin film tends to be deformed.

From the above results, it was shown that the copolymer emulsion of the present invention has excellent polymerization stability, and the thermosetting resin composition containing the copolymer emulsion has excellent thermosetting properties at a low temperature of 120°C.

Examples 19 to 21 and Examples 23 to 25 contain a basic salt containing an acid having a pKa of 2 or higher and an alkali metal, and a basic salt containing an acid having a pKa of 2 or higher and an alkali metal. Compared to Examples 22 and 26, which do not contain, the tensile strength (Tb) of the cured resin film is improved, which is preferable.

In Example 27, in which the copolymer emulsion contained the compound represented by formula (10), the Mw retention rate was 141% even after 28 days, and the copolymer emulsion contained the compound represented by formula (10). It is small compared to Examples 28 and 29 which do not have. This further improves the stability of the blocked isocyanate compound, and even if functional groups with active hydrogen such as carboxy groups, hydroxyl groups and amino groups are contained in the same copolymer (A), during polymerization and storage This is probably because the isocyanato group blocked with the blocking agent can be more stably present.

Claims (20)

1. a copolymer (A) containing a structural unit (A-1) in which an isocyanato group is blocked with a blocking agent and a structural unit (A-2) having an aromatic hydrocarbon group, represented by the following formula (1); , including water and
   A copolymer emulsion containing 0.1 mol % or more and 40 mol % or less of the structural unit (A-1) when the total of all structural units is 100 mol %.
   

   

   [In the formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² represents a saturated divalent to tetravalent aliphatic hydrocarbon having 1 to 20 carbon atoms, including a linear or branched chain which may have an ether bond. a hydrocarbon group, or a divalent alicyclic hydrocarbon group or aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a urethane bond, and R ³ is the blocking agent R ³ —H or It represents the residue of its salt, contains an aromatic ring, and n represents 1 or 2. ]
2. 2. The copolymer emulsion according to claim 1, wherein the structural unit (A-1) is represented by the following formula (1-1).
   

   

   [In formula (1-1), R ¹ and R ³ are the same as the symbols in formula (1), and R ^2-2 is a divalent fatty acid having 2 to 4 carbon atoms which may have an ether bond. indicates a saturated hydrocarbon group. ]
3. 2. The copolymer emulsion according to claim 1, wherein the structural unit (A-1) is represented by the following formula (1-2).
   

   

   [In Formula (1-2), R ¹ and R ³ have the same meanings as the symbols in Formula (1). ]
4. 2. The copolymer emulsion according to claim 1, wherein the structural unit (A-1) is represented by the following formula (1-3).
   

   

   [In formula (1-3), R ¹ , R ² and n have the same meanings as the respective symbols in formula (1), and R ^3-2 represents the residue of the blocking agent R ³ -H or a salt thereof. and R ^3-2 is
   

   

   

   or
   

   

   indicates ]
5. 2. The copolymer emulsion according to claim 1, wherein the structural unit (A-2) is represented by the following formula (2).
   

   

   [In the formula (2), R ⁴ is a hydrogen atom, a linear or branched aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms, or an optionally substituted aromatic hydrocarbon group having 6 to 20 carbon atoms. R ⁵ represents a divalent saturated aliphatic hydrocarbon group having 0 to 8 carbon atoms which may have an ester bond and/or an ether bond; R ⁶ represents a hydrogen atom of which is a thiol group; , a sulfo group, a nitro group, an amino group, a chlorine atom, a fluorine atom, a bromine atom, an iodine atom, an astatine atom, a hydroxy group, an aliphatic saturated hydrocarbon group containing a linear or branched chain having 1 to 4 carbon atoms, a carboxy group , an alkoxy group having 1 to 4 carbon atoms, a carboxyester group having 1 to 4 carbon atoms in the ester moiety, or an aromatic hydrocarbon having 6 to 20 carbon atoms which may be substituted with a carbonyl group having 0 to 4 carbon atoms. indicates a group. ]
6. 2. The composition according to claim 1, wherein said structural unit (A-2) is contained in an amount of 1.0 mol% or more and 99.5 mol% or less when the total of all structural units of said copolymer (A) is 100 mol%. copolymer emulsion of
7. 2. The copolymer emulsion according to claim 1, wherein the copolymer (A) further contains a structural unit (A-3) represented by the following formula (3) as a structural unit of the copolymer (A).
   

   

   [In formula (3), R ⁷ represents a hydrogen atom or a linear or branched aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms. ^R8 is a hydrogen atom substituted with a hydroxy group, an acyl group, an alkoxy group, a carboxy group, a thiol group, a sulfo group, a nitro group, an amino group, a chlorine atom, a fluorine atom, a bromine atom, an iodine atom, or an astatine atom; C 1-18 aliphatic saturated hydrocarbon group with no aromatic ring. ]
8. The copolymer according to claim 7, comprising 0 mol% or more and 94.5 mol% or less of the structural unit (A-3) when the total of all structural units of the copolymer (A) is 100 mol%. polymer emulsion.
9. The copolymer emulsion according to claim 1, which contains a basic salt containing an acid having a pKa of 2 or more and an alkali metal.
10. The copolymer (A) further comprises a structural unit (A-4) represented by the following formula (4-1) or the following formula (4-2) as a structural unit of the copolymer (A). The copolymer emulsion according to item 1.
    

    

    [In formula (4-1), R ⁹ , R ¹⁰ and R ¹¹ each independently represent a hydrogen atom, or a linear or branched chain having 1 to 15 carbon atoms which may contain an ester bond and/or a carboxy group; indicates a hydrocarbon group containing ]
    

    

    [In the formula (4-2), R ¹² represents a hydrogen atom or a saturated aliphatic hydrocarbon group having 1 to 4 carbon atoms including a linear or branched chain having 1 to 4 carbon atoms, and R ¹³ represents an ester bond; and/or a divalent saturated aliphatic hydrocarbon group having 1 to 8 carbon atoms or an aromatic hydrocarbon group having 6 to 20 carbon atoms, which may have a carbonyl group. ]
11. The copolymer according to claim 10, comprising 0 mol% or more and 20.0 mol% or less of the structural unit (A-4) when the total of all structural units of the copolymer (A) is 100 mol%. polymer emulsion.
12. 2. The copolymer emulsion according to claim 1, wherein the structural unit (A-2) is represented by formula (10).
    

    

    [In formula (10), R ¹⁴ represents a hydrogen atom or a methyl group, R ¹⁵ represents an alkylene group having 1 to 4 carbon atoms, and X represents an aromatic group. ]
13. A one-component thermosetting resin composition containing the copolymer emulsion according to claim 1.
14. A paint containing the one-component thermosetting resin composition according to claim 13.
15. A cured resin film (F) obtained by curing the one-liquid thermosetting resin composition according to claim 13.
16. A coating film (G) comprising the cured resin film (F) according to claim 15.
17. A two-part thermosetting resin composition comprising the copolymer emulsion according to claim 1 and an acrylic polyol polymer emulsion (J).
18. A paint containing the two-component thermosetting resin composition according to claim 17.
19. A cured resin film (M) obtained by curing the two-component thermosetting resin composition according to claim 17.
20. A coating film (N) comprising the cured resin film (M) according to claim 19.