JP2020204006A - Composite, method for producing the same, and curable resin composition - Google Patents

Abstract

To provide a novel composite useful as a latent curing agent, and a method for producing the same.SOLUTION: The composite contains a compound having a basic nitrogen atom, and a block copolymer. The block copolymer has: a first block structure containing a constituent unit derived from a compound having an acidic group, and a constituent unit derived from a compound having a hydrophobic group; and a second block structure containing a constituent unit derived from a compound having a hydrophilic group. The compound having a basic nitrogen atom is contained in the block copolymer.SELECTED DRAWING: Figure 1

Description

The present invention relates to a composite, a method for producing the same, and a curable resin composition.

The epoxy resin is a compound having an epoxy group in which the ring-opening reaction proceeds by the compound having nucleophilicity. When an epoxy resin is allowed to coexist with a compound having a nucleophilicity (curing accelerator), the epoxy group ring-opened by the curing accelerator reacts with other epoxy groups one after another (anionic polymerization), resulting in high concentration. It is known to be molecularly weighted to form a cured product. Further, when the epoxy resin coexists with a compound having a plurality of nucleophilic substituents (curing agent), each of the substituents contained in the curing agent opens the epoxy group to form a covalent bond (crosslink). By doing so, it is known to form a highly crosslinked cured product. Adhesives that utilize the curing reaction of such epoxy resins are called epoxy adhesives and are used in various adhesive applications as excellent adhesives. In addition, since the cured product exhibits excellent durability and dimensional stability, for example, it is used for encapsulation of electronic parts on a substrate of an electric product, production of a three-dimensional model, repair of a partially defective member, and the like. in use.

As described above, in the epoxy resin, the epoxy group may be anion-polymerized by the curing accelerator to be cured, or the epoxy group may be cured by undergoing a cross-linking reaction by the curing agent. In either case. There is no difference in that the epoxy resin becomes high molecular weight and hardens. Therefore, in the present specification, the term "curing agent" is used as a concept including both a curing accelerator and a curing agent.

Epoxy adhesives are usually composed of a main agent containing an uncured epoxy resin and a curing agent containing a compound that reacts with an epoxy group, and are used by mixing the two in a ratio of about 1: 1 immediately before use. .. Since the curing reaction in the epoxy adhesive starts immediately after the main agent and the curing agent are mixed, the epoxy adhesive cannot be stored in a mixed state of the main agent and the curing agent, and each time it is used, It is necessary to mix the main agent and the curing agent at a ratio of 1: 1 and an excellent cured product can be obtained, but there is also a problem that the work is complicated.

In order to solve such a problem, a one-component epoxy adhesive has been proposed (see, for example, Patent Document 1). According to Patent Document 1, a curing agent is coated with an inorganic thin layer to form a capsule-type curing agent, which is blended with an uncured epoxy resin to suppress curing at room temperature while heating. Epoxy adhesives that cure with are disclosed. In the capsule-type curing agent used in such an epoxy adhesive, the curing agent exists inside the capsule at room temperature, and the curing reaction of the epoxy resin is suppressed, but the capsule covering the curing agent collapses under heating. By doing so, the curing agent is released from the inside, and the curing reaction of the epoxy resin is promoted.

Further, a one-component epoxy adhesive has been proposed in which a curing agent in which a functional group such as an amino group for exhibiting curability is protected by a protecting group is used as a latent curing agent (for example, Patent Document 2). reference). In the latent curing agent described in Patent Document 2, the protecting group is removed by heating or the like, and the curing reaction of the epoxy resin proceeds.

It has also been proposed to use a block copolymer having a curable functional group in the side chain to form particles having a core-shell structure (see, for example, Patent Document 3). In this case, the curing reaction of the epoxy resin does not proceed at room temperature, but the shell structure collapses due to heating to develop curability, and the curing reaction of the epoxy resin proceeds.

Japanese Unexamined Patent Publication No. 2-03638 Japanese Unexamined Patent Publication No. 9-100456 Japanese Unexamined Patent Publication No. 2012-57146

A main object of the present invention is to provide a novel complex useful as a latent curing agent and a method for producing the same.

One aspect of the present invention is derived from a compound having a basic nitrogen atom and a block copolymer, and the block copolymer is derived from a compound having a structural unit derived from a compound having an acidic group and a compound having a hydrophobic group. A compound having a first block structure containing a structural unit to be used and a second block structure containing a structural unit derived from a compound having a hydrophilic group and having a basic nitrogen atom is included in the block copolymer. It provides a complex that has been used.

The structural unit derived from the compound having an acidic group may be the structural unit represented by the following general formula (11).

[In the general formula (11), R ¹¹ represents a hydrogen atom or a methyl group, and R ¹² represents an acidic organic group. ]

The R ¹² may be a group represented by the following general formula (12).

[In the general formula (12), R ¹³ represents an alkyl group having 1 to 20 carbon atoms, and a represents an integer of 0 to 3. ]

The structural unit derived from the compound having a hydrophobic group may be a structural unit represented by the following general formula (21).

[In the general formula (21), R ²¹ represents a hydrogen atom or a methyl group, R ²² represents an alkyl group having 1 to 20 carbon atoms, and b represents an integer of 0 to 3. ]

The structural unit derived from the compound having a hydrophilic group may be the structural unit represented by the following general formula (31).

[In the general formula (31), R ³¹ represents a hydrogen atom or a methyl group. ]

The second block structure may further include a structural unit represented by the following general formula (41).

[In the general formula (41), R ⁴¹ represents a hydrogen atom or a methyl group, and R ⁴² represents an alkyl group having 1 to 20 carbon atoms. ]

The compound having a basic nitrogen atom may be a compound having an imidazole skeleton, an imidazoline skeleton, a triazine skeleton, or an isocyanuric acid skeleton.

The composite may be a latent curing agent for the epoxy resin.

In another aspect, the present invention provides a curable resin composition containing an epoxy resin and the composite described above.

In another aspect, the present invention prepares, in one aspect, a mixed solution containing a compound having a basic nitrogen atom, a block copolymer, and a first organic solvent, and a second organic solvent, and the mixed solution. Is added to the second organic solvent to provide a method for producing a composite, which comprises a step of obtaining the composite. The block copolymer contains a first block structure containing a structural unit derived from a compound having an acidic group and a structural unit derived from a compound having a hydrophobic group, and a structural unit derived from a compound having a hydrophilic group. It has a second block structure. In the complex, a compound having a basic nitrogen atom is encapsulated in a block copolymer.

In another aspect, the present invention, as another aspect, prepares a first mixed solution containing a compound having a basic nitrogen atom, a block copolymer, and a first organic solvent, and prepares a first mixed solution. A complex comprising a step of adding a hydrophilic solvent to obtain a second mixed solution and a step of adding a second organic solvent to the second mixed solution to obtain a complex. Provide a manufacturing method. The block copolymer contains a first block structure containing a structural unit derived from a compound having an acidic group and a structural unit derived from a compound having a hydrophobic group, and a structural unit derived from a compound having a hydrophilic group. It has a second block structure. In the complex, a compound having a basic nitrogen atom is encapsulated in a block copolymer.

According to the present invention, a novel complex useful as a latent curing agent and a method for producing the same are provided. Further, according to the present invention, a curable resin composition containing such a composite is provided.

FIG. 1 is a schematic diagram showing how a complex is formed by self-organization. FIG. 1A is a schematic view showing how the complex is formed by the precipitation method (one-step self-organization method), and FIG. 1B is a schematic view showing how the complex is formed by the two-step self-organization method. It is a schematic diagram which shows the state of being done.

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

As used herein, (meth) acrylate means acrylate or the corresponding methacrylate. The same applies to other similar expressions such as (meth) acrylic acid, (meth) acrylamide, and (meth) acryloyl.

[Complex]
The complex of one embodiment contains a compound having a basic nitrogen atom and a block copolymer.

<Compound with basic nitrogen atom>
Examples of the compound having a basic nitrogen atom include a primary amine, a secondary amine, a tertiary amine, a nitrogen-containing heterocyclic compound and the like. Among these, the compound having a basic nitrogen atom may be a nitrogen-containing heterocyclic compound, or may be a compound having an imidazole skeleton, an imidazoline skeleton, a triazine skeleton, or an isocyanuric acid skeleton. Examples of these compounds include 2-methylimidazole, 2-undecyl imidazole, 2-heptadecyl imidazole, 2-ethyl-4-methyl imidazole, 2-phenyl imidazole, 2-phenyl-4-methyl imidazole, 1-. Benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1,2-dimethylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2 -Phenylimidazole, 1-cyanoethyl-2-undecyl imidazolium trimerite, 1-cyanoethyl-2-phenylimidazolium trimerite, 2,4-diamino-6- [2'-methylimidazolyl- (1') ] -Ethyl-s-triazine, 2,4-diamino-6- [2'-undecylimidazolyl- (1')]-ethyl-s-triazine, 2,4-diamino-6- [2'-ethyl- 4'-methyl-imidazolylou (1')] -ethyl-s-triazine, 2,4-diamino-6- [2'-methylimidazolyl- (1')]-ethyl-s-triazine isocyanuric acid adduct, Isocyanuric acid adduct of 2-phenylimidazole, isocyanuric acid adduct of 2-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3- Dihydro-1H-pyrrolo [1,2-a] benzimidazole, 1-benzyl-2-phenylimidazole hydrobromide, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, 2 -Phenylimidazolin, 2,4-diamino-6-vinyl-s-triazine, 2,4-diamino-6-vinyl-s-triazine isocyanuric acid adduct, 2,4-diamino-6-methacryloyloxyethyl-s Examples thereof include an isocyanuric acid adduct of −triazine, 2,4-diamino-6-methacryloyloxyethyl-s-triazine. The compound having a basic nitrogen atom may be a compound having an imidazole skeleton, or 2-phenylimidazole, 2-methylimidazole, 1,2-dimethylimidazole, or 1-benzyl-2-methylimidazole. It may be 2-phenylimidazole.

<Block copolymer>
The block copolymer contains a first block structure containing a structural unit derived from a compound having an acidic group and a structural unit derived from a compound having a hydrophobic group, and a structural unit derived from a compound having a hydrophilic group. It has a second block structure. The block copolymer has at least two block structures having different affinities for an organic solvent or a hydrophilic solvent. Therefore, the block copolymer is self-assembled by the method described later to form a core structure with a compound having a basic nitrogen atom and a first block structure, and a shell with a second block structure. Therefore, a core-shell type complex can be obtained.

(First block structure)
The first block structure contains a structural unit derived from a compound having an acidic group and a structural unit derived from a compound having a hydrophobic group. A structural unit derived from a compound having an acidic group is a structural unit capable of interacting with a compound having a basic nitrogen atom such as a hydrogen bond, and a structural unit derived from a compound having a hydrophobic group has a core structure. When formed, it is a structural unit that can contain a compound having a basic nitrogen atom.

The structural unit derived from the compound having an acidic group may be the structural unit represented by the following general formula (11).

In the general formula (11), R ¹¹ represents a hydrogen atom or a methyl group, and R ¹² represents an acidic organic group.

R ¹² is not particularly limited, but may be an organic group having an acidic group such as a carboxyl group or a sulfo group, or may be an organic group having a carboxyl group. Examples of the organic group include an alkylene group having 1 to 20 carbon atoms which may have a branch such as a methylene group, an ethylene group, a propylene group and an isopropylene group, a phenylene group which may have a substituent, and a substituent. Examples thereof include aromatic groups such as a naphthylene group which may have a group.

Since R ¹² can easily form a stable core structure, it may be a group represented by the following general formula (12).

In the general formula (12), R ¹³ represents an alkyl group having 1 to 20 carbon atoms, and a represents an integer of 0 to 3.

Examples of the compound having an acidic group include 4-vinylbenzoic acid, 3-vinylbenzoic acid, 2-vinylbenzoic acid, (meth) acrylic acid, 2- (meth) acryloyloxyethyl hexahydrophthalic acid, 2-(. Meta) Acryloyloxypropyl Hexahydrophthalic Acid, 2- (Meta) Acryloyloxyethyl Tetrahydrophthalic Acid, 2- (Meta) Acryloyloxypropyl Tetrahydrophthalic Acid, 5-Methyl-2- (Meta) Acryloyloxyethyl Hexahydrophthalic Acid , 2- (meth) acryloyloxyethyl phthalic acid, 2- (meth) acryloyloxypropyl phthalic acid, 2- (meth) acryloyloxyethyl phthalic acid, 2- (meth) acryloyloxypropyl phthalic acid, crotonic acid, sorbic acid And so on. Among these, the compound having an acidic group may be 4-vinylbenzoic acid.

The structural unit derived from the compound having a hydrophobic group may be a structural unit represented by the following general formula (21).

In the general formula (21), R ²¹ represents a hydrogen atom or a methyl group, R ²² represents an alkyl group having 1 to 20 carbon atoms, and b represents an integer of 0 to 3.

Examples of the compound having a hydrophobic group include styrene, p-methylstyrene, o-methylstyrene, m-methylstyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, 3,4-dimethylstyrene, 3 , 5-Dimethylstyrene, alkylstyrenes such as p-terchary butylstyrene; p-chlorostyrene, m-chlorostyrene, o-chlorostyrene, p-bromostyrene, m-bromostyrene, o-bromostyrene, p-fluoro Halogenized styrene such as styrene, m-fluorostyrene, o-fluorostyrene, o-methyl-p-fluorostyrene; vinyl biphenyls such as 4-vinylbiphenyl, 3-vinylbiphenyl, 2-vinylbiphenyl; 1- (4) -Vinylphenyl) -naphthalene, 2- (4-vinylphenyl) -naphthalene, 1- (3-vinylphenyl) -naphthalene, 2- (3-vinylphenyl) -naphthalene, 1- (2-vinylphenyl) -naphthalene , 2- (2-Vinylphenyl) Naphthalene and other vinylphenylnaphthalene; 1- (4-vinylphenyl) -anthracene, 2- (4-vinylphenyl) -anthracene, 9- (4-vinylphenyl) -anthracene, 1- (3-vinylphenyl) -anthracene, 2- (3-vinylphenyl) -anthracene, 9- (3-vinylphenyl) -anthracene, 1- (2-vinylphenyl) -anthracene, 2- (2-vinyl) Vinylphenyl anthracenes such as phenyl) -anthracene, 9- (2-vinylphenyl) -anthracene; 1- (4-vinylphenyl) -phenanthrene, 2- (4-vinylphenyl) -phenanthrene, 3- (4-vinyl) Phenyl) -phenanthrene, 4- (4-vinylphenyl) -phenanthrene, 9- (4-vinylphenyl) -phenanthrene, 1- (3-vinylphenyl) -phenanthrene, 2- (3-vinylphenyl) -phenanthrene, 3 -(3-Vinylphenyl) -Phenylentren, 4- (3-Vinylphenyl) -Phenylentren, 9- (3-Vinylphenyl) -Phenylentren, 1- (2-Vinylphenyl) -Phenylentren, 2- (2-Vinylphenyl) )-Phenylphenyl phenanthrenes such as 3- (2-vinylphenyl) -phenanthrene, 4- (2-vinylphenyl) -phenanthrene, 9- (2-vinylphenyl) -phenanthrene; 1- (4-vinylphenyl) ) -Pile , 2- (4-vinylphenyl) -pyrene, 1- (3-vinylphenyl) -pyrene, 2- (3-vinylphenyl) -pyrene, 1- (2-vinylphenyl) -pyrene, 2- (2) -Vinylphenyl) -vinylphenyl pyrene such as pyrene; 4-vinyl-p-terphenyl, 4-vinyl-m-terphenyl, 4-vinyl-o-terphenyl, 3-vinyl-p-terphenyl, 3 -Vinyl terphenyls such as -vinyl-m-terphenyl, 3-vinyl-o-terphenyl, 2-vinyl-p-terphenyl, 2-vinyl-m-terphenyl, 2-vinyl-o-terphenyl; Vinylphenyl terphenyls such as 4- (4-vinylphenyl) -p-terphenyl; 4-vinyl-4'-methylbiphenyl, 4-vinyl-3'-methylbiphenyl, 4-vinyl-2'-methylbiphenyl , 2-Methyl-4-vinylbiphenyl, 3-methyl-4-vinylbiphenyl and other vinylalkylbiphenyls; 4-vinyl-4'-fluorobiphenyl, 4-vinyl-3'-fluorobiphenyl, 4-vinyl-2 '-Fluorobiphenyl, 4-vinyl-2-fluorobiphenyl, 4-vinyl-3-fluorobiphenyl, 4-vinyl-4'-chlorobiphenyl, 4-vinyl-3'-chlorobiphenyl, 4-vinyl-2'- Chlorobiphenyl, 4-vinyl-2-chlorobiphenyl, 4-vinyl-3-chlorobiphenyl, 4-vinyl-4'-bromobiphenyl, 4-vinyl-3'-bromobiphenyl, 4-vinyl-2'-bromobiphenyl , 4-Vinyl-2-bromobiphenyl, 4-vinyl-3-bromobiphenyl and other halogenated vinyl biphenyls; 4-vinyl-4'-trimethylsilylbiphenyl and other trialkylsilylvinylbiphenyls; 4-vinyl-4' Trialkylstannylvinylbiphenyls such as −trimethylstannylbiphenyl, 4-vinyl-4'-tributylstannylbiphenyl; trialkylsilylmethylvinylbiphenyls such as 4-vinyl-4'-trimethylsilylmethylbiphenyl; 4-vinyl Trialkylstannylmethylvinylbiphenyls such as -4'-trimethylstannylmethylbiphenyl, 4-vinyl-4'-tributylstannylmethylbiphenyl; p-chloroethylstyrene, m-chloroethylstyrene, o-chloroethylstyrene Halogen-substituted alkyl styrenes such as p-trimethylsilylstyrene, m-trimethy Alkylsilylstyrenes such as lusilylstyrene, o-trimethylsilylstyrene, p-triethylsilylstyrene, m-triethylsilylstyrene, o-triethylsilylstyrene, p-dimethyltersary-butylsilylstyrene; p-dimethylphenylsilylstyrene, Penyl group-containing silyl styrenes such as p-methyldiphenylsilylstyrene and p-triphenylsilylstyrene; p-dimethylchlorosilylstyrene, p-methyldichlorosilylstyrene, p-trichlorosilylstyrene, p-dimethylbromosilylstyrene, p. Halogen-containing silyl styrenes such as −dimethyliodosilylstyrene; silyl group-containing silylstyrenes such as p- (p-trimethylsilyl) dimethylsilylstyrene and the like can be mentioned.

The first block structure may be, for example, a structure represented by the following general formula (50).

In the general formula (50), A represents a structural unit derived from a compound having a hydrophobic group, and B represents a structural unit derived from a compound having an acidic group. In addition, -r- is a code indicating that it is a random copolymer. k indicates the degree of polymerization of the structural unit derived from the compound having a hydrophobic group, and l indicates the degree of polymerization of the structural unit derived from the compound having an acidic group. k may be 20-200, 35-180, or 45-160. l may be 60-500, 150-400, or 220-350. The ratio of l to k (l / k) may be 1.8 or more, 2.0 or more, or 2.2 or more, 4.5 or less, 4.2 or less, or 4.0 or less. Good.

The first block structure may contain a structural unit other than the structural unit derived from the compound having an acidic group and the structural unit derived from the compound having a hydrophobic group.

(Second block structure)
The second block structure contains structural units derived from compounds having hydrophilic groups. A structural unit derived from a compound having a hydrophilic group is a structural unit capable of forming a core-shell type shell structure.

The structural unit derived from the compound having a hydrophilic group may be the structural unit represented by the following general formula (31). Since the amide groups contained in the structural unit represented by the general formula (31) can be strongly associated with each other by hydrogen bonds, when forming a core-shell type complex by self-assembly by the method described later, A shell structure can be formed.

In the general formula (31), R ³¹ represents a hydrogen atom or a methyl group.

The compound having a hydrophilic group may be (meth) acrylamide.

The second block structure may contain a structural unit other than the structural unit derived from the compound having a hydrophilic group. Examples of such a structural unit include a structural unit represented by the following general formula (41) (a structural unit derived from an alkyl (meth) acrylate). By including the structural unit represented by the general formula (41) in the second block structure, the synthesis of the second block structure becomes easy, and the action of hydrogen bonding of the structural unit derived from the compound having a hydrophilic group can be suppressed. By lowering the stability of the shell structure, it is possible to adjust the temperature at which the shell structure collapses. Therefore, when the composite of the present embodiment is used as a latent curing agent for an epoxy resin, the curing temperature can be adjusted.

In the general formula (41), R ⁴¹ represents a hydrogen atom or a methyl group, and R ⁴² represents an alkyl group having 1 to 20 carbon atoms.

Examples of the compound constituting the structural unit represented by the general formula (41) include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, and tert-butyl (meth). Acrylate, butoxyethyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, heptyl (meth) acrylate, octylheptyl (meth) acrylate, nonyl (meth) acrylate, decyl ( Meta) acrylate and the like can be mentioned. Among these, the compound constituting the structural unit represented by the general formula (41) may be methyl (meth) acrylate.

The second block structure may be, for example, a structure represented by the following general formula (60).

In the general formula (60), C represents a structural unit derived from a compound having a hydrophilic group, and D is a structural unit other than the structural unit derived from a compound having a hydrophilic group (for example, represented by the general formula (41). The structural unit to be used) is shown. In addition, -r- is a code indicating that it is a random copolymer. m indicates the degree of polymerization of the structural unit derived from the compound having a hydrophilic group, and n indicates the degree of polymerization of the structural unit other than the structural unit derived from the compound having a hydrophilic group. m may be 20-360, 40-250, or 80-200. n may be 0 to 100, 5 to 50, or 10 to 25. The ratio of n to m (n / m) may be 0 or more, 0.01 or more, or 0.03 or more, and may be 1 or less, 0.8 or less, or 0.6 or less.

The block copolymer may be, for example, a block copolymer having a structure represented by the following general formula (70).

In the general formula (70), A, B, C, D, k, l, m, and n have the same meanings as described above. In addition, -r- is a code indicating that it is a random copolymer, and -b- is a code indicating that it is a block copolymer. R ^A and R ^B are terminal portion to be introduced in the synthesis of block copolymer described later, for example, may be the residue of a chain transfer agent described later (CTA). As a chain transfer agent (CTA), when using [1-(O-Echiruzanchiru) ethyl] benzene, ^{R A} is a phenyl ethyl group, ^{R B} is ethoxy thiocarbonyl thio group. Also, when using cumyl dithiobenzoate, R ^A is a cumyl group, R ^B is phenyl thiocarbonyl thio group.

The number average molecular weight of the block copolymer may be, for example, 20000 to 150,000, 30,000 to 100,000, or 40,000 to 70,000. The number average molecular weight can be determined by the following method. First, the number average molecular weight of a random copolymer having a structure represented by the general formula (50) (a value measured by gel permeation chromatography (GPC) and converted using a calibration line using standard polystyrene) and ¹ The average degrees of polymerization k, l, m, and n are obtained from the composition ratio of the block copolymer having the structure represented by the general formula (70) obtained by H-NMR measurement. Next, the product of these average degrees of polymerization and the molecular weight of each component is calculated, and the sum of the calculated products is obtained to obtain the number average molecular weight of the block copolymer.

The method for synthesizing the block copolymer is not particularly limited, and various known organic synthesis methods can be used. Among these organic synthesis methods, the organic synthesis method is a kind of living radical polymerization because it does not use a metal catalyst or the like and can easily polymerize a monomer having a base moiety coordinated with a metal. It may be a reversible addition cleavage chain transfer (RAFT) polymerization method (RAFT: Reversible Addition-Fragmentation Chain Transfer). Next, an example of a method for synthesizing a block copolymer using the RAFT polymerization method will be described.

First, a radical polymerization initiator and a chain transfer agent are added to a solution containing a first monomer such as a compound having an acidic group and a compound having a hydrophobic group to form a first block structure, and radical polymerization is carried out. Let me.

As the radical polymerization initiator, a known radical polymerization initiator can be used, for example, azobisisobutyronitrile (AIBN), 1,1'-azobis (cyclohexanecarbonitrile), 2,2'-azobis. Polymerization of azo compounds such as (2-methylpropionitrile), 4,4'-azobis (4-cyanopropionic acid), (2RS, 2'RS) -azobis (4-methoxy-2,4-dimethylvaleronitrile) Examples thereof include an initiator and a polymerization initiator of a peroxide such as benzobis peroxide.

Examples of the chain transfer agent (RAFT agent) include 2-cyano-2-benzodithioate, 4-cyano-4- (phenylcarbonotioilthio) pentanoic acid, and 2-cyano-2-propyldodecyltrithiocarbonate. , 4-Cyano-4-[(dodecylsulfanylthiocarbonyl) sulfanyl] pentanoic acid, 2- (dodecylthiocarbonothioilthio) -2-methylpropionic acid, cyanomethyldodecyltrithiocarbonate, cyanomethylmethyl (phenyl) Dithioester compounds such as carbamodithioate, bis (thiobenzoyl) disulfide, bis (dodecylsulfanylthiocarbonyl) disulfide, cumyldithiobenzoate, [1- (O-ethylzantyl) ethyl] benzene, 4-trimethylsilylbenzyl dithiopropinate. And so on.

The molar ratios of the first monomer, radical polymerization initiator, and chain transfer agent can be appropriately set according to the desired properties of the first block structure, and for example, the first monomer: radical polymerization initiator. : The chain transfer agent may be 1000: 0.5 to 50: 10 to 100, or 1000: 0.5: 10.

The first block structure can be formed by the RAFT polymerization. At this time, residues of the chain transfer agent (RAFT agent) used are present at both ends of the first block structure. Therefore, in the first block structure, the first block structure itself acts as a chain transfer agent (RAFT agent) when synthesizing the second block structure.

Next, a second monomer such as a compound having a hydrophilic group for forming the second block structure and a radical polymerization initiator are added to the solution containing the first block structure to form the first block structure. A second block structure is formed at one end of the. As the radical polymerization initiator, the same one used in synthesizing the first block structure can be used.

The molar ratios of the first block structure, the second monomer, and the radical polymerization initiator can be appropriately set according to the desired properties of the block copolymer. For example, the first block structure: the second. Monomer: The radical polymerization initiator may be 1: 0.1 to 50: 0.01 to 0.1, or 1: 1: 0.04.

By the above synthesis method, a block copolymer having a structure represented by the general formula (70) can be obtained.

In the complex of the present embodiment, a compound having a basic nitrogen atom is encapsulated in a block copolymer. The block copolymer is a core-shell type complex in which a compound having a basic nitrogen atom and a first block structure form a core structure and a second block structure forms a shell structure by self-assembly. Can be formed.

[Manufacturing method of complex]
The method for producing the composite will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing how a complex is formed by self-organization. FIG. 1A is a schematic view showing how the complex is formed by the precipitation method (one-step self-organization method), and FIG. 1B is a schematic view showing how the complex is formed by the two-step self-organization method. It is a schematic diagram which shows the state of being done. In FIG. 1, as an example, dimethyl sulfoxide (DMSO) was used as the first organic solvent, acetonitrile was used as the second organic solvent, and water was used as the hydrophilic solvent. As shown in FIG. 1, a block copolymer is a linear molecule having a first block structure and a second block structure. In practice, the both ends of the linear molecule, although there are R ^A and R ^B, very molecular weight for these substituents first block structure and a second block structure Since they are small, they are omitted in FIG.

First, a method for producing a complex by the precipitation method (one-step self-organization method) shown in FIG. 1A will be described. In the method for producing the complex shown in FIG. 1A, a compound having a basic nitrogen atom, a block copolymer, a mixed solution containing a first organic solvent, and a second organic solvent are prepared. It comprises a step of adding a mixed solution to a second organic solvent to obtain a complex. The block copolymer contains a first block structure containing a structural unit derived from a compound having an acidic group and a structural unit derived from a compound having a hydrophobic group, and a structural unit derived from a compound having a hydrophilic group. It has a second block structure. In the complex, a compound having a basic nitrogen atom is encapsulated in a block copolymer.

In the method for producing such a complex, first, a mixed solution containing a compound having a basic nitrogen atom, a block copolymer, and a first organic solvent is prepared. Here, the first organic solvent is a solvent that can dissolve a compound having a basic nitrogen atom and a block copolymer, and is miscible with the second organic solvent described later. The term "indicating mixability" as used herein means that the first organic solvent and the second organic solvent do not necessarily have to be mixed at an arbitrary volume ratio, and at least a part of the first organic solvent is mixed. Sufficient.

The first organic solvent is not particularly limited as long as it dissolves a compound having a basic nitrogen atom and a block copolymer. Examples of the first organic solvent include dimethyl sulfoxide (DMSO), dimethylacetamide (DMAc), dimethylformamide (DMF), N-methyl-2-pyrrolidone (NMP) and the like. These first organic solvents may be used alone or in combination of two or more. The first organic solvent may be at least one selected from the group consisting of DMSO, DMAc, DMF, and NMP, and may be DMSO.

The concentration of the compound having a basic nitrogen atom in the first organic solvent can be appropriately determined in consideration of the solubility of the compound having a basic nitrogen atom, and basic nitrogen per 1 mL of the first organic solvent. It suffices if 50 to 300 mg of the compound having an atom can be dissolved, and 100 to 180 mg can be dissolved.

The concentration of the block copolymer in the first organic solvent can be appropriately determined in consideration of the solubility of the block copolymer, and 50 to 500 mg of the block copolymer is dissolved in 1 mL of the first organic solvent. It suffices if it can be dissolved, and 100 to 150 mg can be dissolved.

In order to dissolve the block copolymer in the first organic solvent, a known method can be used without particular limitation. Examples of such a method include a method in which a block copolymer is added to a first organic solvent and then stirred or ultrasonic vibration is applied. The mixture of the first organic solvent and the block copolymer may be heated.

Then, the obtained mixed solution is added to a second organic solvent to precipitate (precipitate) the complex, whereby the complex can be obtained. Here, the second organic solvent is a solvent that is miscible with the first organic solvent and is not soluble in any of the block structures in the block copolymer. When the obtained mixed solution is added to the second organic solvent, the solubility of the block copolymer rapidly decreases, and the block copolymer precipitates. At this time, the block copolymer self-centers on the compound having a basic nitrogen atom, with the first block structure of the block copolymer facing inward and the second block structure of the block copolymer facing outward. It is speculated that the core structure is formed by the compound having a basic nitrogen atom and the first block structure, and the second block structures form an aggregate by hydrogen bonds to form a shell structure. Will be done. Finally, by separating the complex from the mixed solvent and drying it, a core-shell type complex can be obtained.

The second organic solvent can be used without particular limitation as long as it is a solvent that is miscible with the first organic solvent and does not show solubility in any block structure in the block copolymer. The second organic solvent is different from the first organic solvent. Examples of the second organic solvent include acetonitrile, diethyl ether, ethyl acetate, acetone and the like. These second organic solvents may be used alone or in combination of two or more. The second organic solvent may be at least one selected from the group consisting of acetonitrile, diethyl ether, ethyl acetate, and acetone, and may be acetonitrile.

Next, a method for producing the complex by the two-step self-organization method shown in FIG. 1 (b) will be described. In the method for producing the complex shown in FIG. 1A, a first mixed solution containing a compound having a basic nitrogen atom, a block copolymer, and a first organic solvent is prepared, and the first mixed solution is prepared. On the other hand, a step of adding a hydrophilic solvent to obtain a second mixed solution and a step of adding a second organic solvent to the second mixed solution to obtain a complex are provided. The block copolymer contains a first block structure containing a structural unit derived from a compound having an acidic group and a structural unit derived from a compound having a hydrophobic group, and a structural unit derived from a compound having a hydrophilic group. It has a second block structure. In the complex, a compound having a basic nitrogen atom is encapsulated in a block copolymer.

In the method for producing such a complex, first, a compound having a basic nitrogen atom, a block copolymer, and a mixed solution containing a first organic solvent, a second organic solvent, and a hydrophilic solvent are prepared. Then, a hydrophilic solvent is added to the first mixed solution containing the compound having a basic nitrogen atom and the block copolymer. As a result, a plurality of molecules of the block copolymer are self-assembled, and the first block structure of the block copolymer is self-assembled inward and the second block structure of the block copolymer is self-assembled outward. Micelle) is formed. At this time, the compound having a basic nitrogen atom is encapsulated inside the first block structure by interaction with the first block structure of the block copolymer to form a core structure. The reason why the second block structure of the block copolymer is directed outward is that the proportion of the hydrophilic solvent increases. In this way, a second mixed solution containing micelles can be obtained.

Here, the existence of three elements can be considered as the reason why micelles are formed in the block copolymer as described above. First, as described above, it is conceivable that the block copolymer was placed in a hydrophilic environment. Secondly, the presence of an amide group contained in the second block structure is considered. As described above, the amide group can be associated with a plurality of amide groups by hydrogen bonding. Therefore, it is considered that the plurality of block copolymers that have started forming micelles form an aggregate by hydrogen bonds between the second block structures to form a shell structure. And thirdly, the existence of hydrophobic interaction between the first block structures is considered. Since the first block is hydrophobic, it is considered that the first blocks aggregate to form a core structure when placed in a hydrophilic environment.

As the first organic solvent and the second organic solvent, the same ones as exemplified above can be used.

Examples of the hydrophilic solvent include water; alcohols such as methanol, ethanol and propanol; and acetone. These hydrophilic solvents may be used alone or in combination of two or more. Among these, the hydrophilic solvent may be water or alcohol, and may be water or methanol.

Then, the second organic solvent is added to the second mixed solution containing micelles. As a result, the solubility of the block copolymer is lowered, and the block copolymer is gradually precipitated. At this time, it is presumed that the second block structures form an aggregate by hydrogen bonds to form a shell structure and form a complex. Finally, by separating the complex from the mixed solvent and drying it, a core-shell type complex can be obtained.

In the complex of the present embodiment, a compound having a basic nitrogen atom is encapsulated in a block copolymer. A compound having a basic nitrogen atom acts as a curing agent for curing an epoxy resin, for example, but a compound having a basic nitrogen atom is not exposed to the outside at room temperature (for example, 25 ° C.), so that the epoxy resin has a compound. Does not act as a hardener. On the other hand, when the composite is heated, the shell structure collapses and the compound having a basic nitrogen atom is exposed to the outside and acts as a curing agent for the epoxy resin. Due to such an action, the composite of the present embodiment has a potential as a curing agent for an epoxy resin, triggered by a temperature change. The acrylamide group contained in the shell structure (second block structure) contains a nitrogen atom, but the nitrogen atom is adjacent to a carbonyl group, which is an electron-withdrawing group, and does not show basicity. It cannot act as a resin curing agent. The composite of this embodiment may be a latent curing agent for epoxy resin.

The ratio of the first block structure to the second block structure in the block copolymer can be expressed as (k + l) :( m + n) using the above-mentioned k, l, m, and n, and each core. Corresponds to the thickness of the shell and the thickness of the shell. If (m + n) is smaller than (k + l), the shell is likely to collapse and acts as a curing agent for the epoxy resin at a lower temperature. On the other hand, if (m + n) is larger than (k + l), the shell is less likely to collapse and acts as a curing agent for the epoxy resin at a higher temperature. The ratio of (k + l) to (m + n) adjusts the molar ratio of the first monomer constituting the first block structure and the second monomer constituting the second block structure when the polymerization reaction is carried out. It can be adjusted by doing so.

The relationship between (k + l) and (m + n) may be 0.5 to 3.3 or 0.8 to 2.2 for (k + l) / (m + n). When (k + l) / (m + n) is 3.3 or less, the potential as a curing agent tends to be satisfactorily obtained.

The composite of the present embodiment is particularly useful as a latent curing agent for anisotropic conductive adhesives.

[Curable resin composition]
The curable resin composition of one embodiment contains an epoxy resin and the above-mentioned composite. Usually, a curable resin composition containing an epoxy resin and a general curing agent proceeds with a curing reaction immediately after being mixed. However, in the composite of the present embodiment, since the compound having a basic nitrogen atom acting as a curing agent is contained in the block copolymer, the curing reaction of the epoxy resin occurs at room temperature (for example, 25 ° C.). Does not progress.

The epoxy resin is not particularly limited as long as it has an epoxy group, and a polymer, oligomer, or monomer having an epoxy group used in the field of adhesive applications can be used.

The content ratio of the epoxy resin and the composite may be 0.001 to 0.1 equivalent or 0.002 to 0.05 equivalent of the latent curing agent with respect to 1 equivalent of the epoxy group of the epoxy resin. The "equivalent" here means a molar equivalent.

The curable resin composition may contain a curing agent other than the above-mentioned composite. Examples of other curing agents include phenolic resole or novolak, tertiary amine compound, acid anhydride and the like. These may be used individually by 1 type or in combination of 2 or more type. Examples of the phenolic novolak include phenol novolak, xylylene novolak, bisphenol A novolak, triphenylmethane novolak, biphenyl novolak, dicyclopentadienephenol novolak, terpenphenol novolak and the like.

The content ratio of the epoxy resin to the other curing agent may be 0.5 to 1.5 equivalents of the latent curing agent with respect to 1 equivalent of the epoxy group of the epoxy resin. The "equivalent" here means a molar equivalent.

Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited thereto.

(Production Example 1-1: Synthesis of the first block structure (P-1))
Styrene (St) as a compound having a hydrophobic group, 4-vinylbenzoic acid (VBA) as a compound having an acidic group, azobisisobutyronitrile (AIBN) as a reaction initiator, 4-as a chain transfer agent (CTA). RAFT polymerization was performed using trimethylsilylbenzyl dithiopropinate. To a 50 mL Schlenk tube, 0.048 g (0.16 mmol) of 4-trimethylsilylbenzyl dithiopropineto, 1.67 g (16 mmol) of St, 4.74 g (32 mmol) of VBA and 7 mL of 1,4-dioxane as a polymerization solvent are added and stirred. To obtain a uniform solution. 6.6 mg of AIBN was added to the solution to dissolve it, and freeze degassing was performed to remove oxygen present in the solution and oxygen in the reaction system. After freezing and degassing, the polymerization reaction was carried out by stirring at 70 ° C. for 24 hours. The polymerization reaction was stopped by quenching the obtained reaction solution with cold methanol. The reaction solution was diluted with 1,4-dioxane, reprecipitated and purified with chloroform, and then the solid recovered by suction filtration was dried under reduced pressure for 8 hours, and reprecipitation and purification were performed a plurality of times. The first block structure PSt-r-PVBA (P-1) was obtained as a yellow solid in a yield of 5.80 g and a yield of 89.9%. In the first block structure (P-1), k was 153, l was 383, and the number average molecular weight (Mn) was 73100. In the following formula, "-r-" described in the first block structure (P-1) is a symbol indicating that it is a random copolymer.

(Production Example 1-2: Synthesis of block copolymer (B-1) by synthesis of second block structure)
The first block structure (AAm) as a compound having a hydrophilic group, methyl methacrylate (MA) as another compound, azobisisobutyronitrile (AIBN) as a reaction initiator, and a chain transfer agent (CTA). RAFT polymerization was carried out using P-1) (number average molecular weight (Mn): 73100). In a 50 mL Schlenk tube, 2.1 g (0.029 mmol) of the first block structure (P-1), 0.28 g (3.90 mmol) of AAm, 0.034 g (0.39 mmol) of MA, and DMSO (dimethyl sulfoxide) as a polymerization solvent. 4.5 mL was added and stirred to obtain a uniform solution. 1.2 mg of AIBN was added to the solution to dissolve it, and freeze degassing was performed to remove oxygen present in the solution and oxygen in the reaction system. After freezing and degassing, the polymerization reaction was carried out by stirring at 70 ° C. for 24 hours. The polymerization reaction was stopped by quenching the obtained reaction solution with cold methanol. The reaction solution is diluted with DMSO, reprecipitated and purified with chloroform, and then the solid recovered by suction filtration is dried under reduced pressure for 8 hours to yield 2.34 g of the block copolymer (B-1). , Yield 97%. In the block copolymer (B-1), k was 153, l was 383, m was 88, and n was 13. In the following formula, "-r-" described in the block copolymer (B-1) is a code indicating that it is a random copolymer, and "-b-" is a block copolymer weight. It is a code indicating that it is a coalescence.

(Example 1: Preparation of a complex (C-1) of 2-phenylimidazole and a block copolymer (B-1) by a two-step self-assembling method)
To a 100 mL eggplant flask, 200 mg of block copolymer (B-1) and 1 mL of DMSO as the first organic solvent were added and stirred to obtain a uniform solution. To the obtained uniform solution, 200 mg of 2-phenylimidazole (2-PhIm) as a compound having a basic nitrogen atom was added, and the mixture was stirred for 1 hour. To the solution that became uniform after stirring, 10 mL of pure water was added dropwise as a hydrophilic solvent using a syringe pump, and the mixture was stirred at room temperature for 24 hours, 20 mL of acetonitrile was added as a second organic solvent, and further stirring was performed for 24 hours. .. After stirring, the mixture was filtered using a glass filter and dried under reduced pressure to obtain a white solid. The obtained solid was washed with acetonitrile and dried under reduced pressure to obtain a complex (C-1) of 2-phenylimidazole and a block copolymer in a yield of 24%.

(Production Example 2-2: Synthesis of block copolymer (B-2) by synthesis of second block structure)
The amount of the first block structure (P-1) used was changed from 2.1 g to 1.5 g, the amount of AAm used was changed from 0.28 g to 0.218 g, and the amount of MA used was changed from 0.034 g. A block copolymer (B-2) was obtained in a yield of 1.53 g and a yield of 89% in the same manner as in Production Example 1-2 except that the weight was changed to 0 g. In the block copolymer (B-2), k was 153, l was 383, m was 114, and n was 0.

(Example 2: Preparation of a complex (C-2) of 2-phenylimidazole and block copolymer (B-2) by a two-step self-assembling method)
A complex (C) of 2-phenylimidazole and a block copolymer (C) in the same manner as in Example 1 except that the block copolymer (B-2) was used instead of the block copolymer (B-1). -2) was obtained in a yield of 30%.

(Production Example 3-1: Synthesis of the first block structure (P-3))
The amount of 4-trimethylsilylbenzyldithiopropinate used was changed from 0.048 g to 0.0902 g, the amount of St used was changed from 1.67 g to 3.13 g, and the amount of VBA used was changed from 4.74 g to 8.89 g. In the same manner as in Production Example 1-1, except that the amount of AIBN used was changed from 6.6 mg to 12.3 mg and the amount of 1,4-dioxane used was changed from 7 mL to 13.2 mL. The first block structure PSt-r-PVBA (P-3) was obtained as a yellow solid in a yield of 10.9 g and a yield of 90%. In the first block structure (P-3), k was 106, l was 214, and the number average molecular weight (Mn) was 42900.

(Production Example 3-2: Synthesis of block copolymer (B-3) by synthesis of second block structure)
2.1 g of the first block structure (P-1) was changed to 1.70 g of the first block structure (P-3), the amount of AAm used was changed from 0.28 g to 0.403 g, and MA was used. Production Example 1 except that the amount was changed from 0.034 g to 0.0244 g, the amount of AIBN used was changed from 1.2 mg to 1.64 mg, and the amount of DMSO used was changed from 4.5 mL to 5.96 mL. In the same manner as in -2, the block copolymer (B-3) was obtained in a yield of 1.48 g and a yield of 70%. In the block copolymer (B-3), k was 83, l was 228, m was 176, and n was 9.

(Example 3: Preparation of a complex (C-3) of 2-phenylimidazole and block copolymer (B-3) by a two-step self-assembling method)
To a 50 mL eggplant flask, 101 mg of block copolymer (B-3) and 0.5 mL of DMSO as the first organic solvent were added, and the mixture was stirred to obtain a uniform solution. To the obtained uniform solution, 100 mg of 2-phenylimidazole (2-PhIm) as a compound having a basic nitrogen atom was added and stirred. To the solution that became uniform after stirring, 10 mL of pure water was added dropwise using a syringe pump, the mixture was stirred at room temperature for 24 hours, 15 mL of acetonitrile was added, and the mixture was further stirred for 24 hours. After stirring, the mixture was filtered using a membrane filter (0.2 μm). Washing with acetonitrile was performed a plurality of times, and after filtration, drying under reduced pressure was carried out to obtain a complex (C-3) of 2-phenylimidazole and a block copolymer in a yield of 21%.

(Example 4: Preparation of complex (C-4) of 2-methylimidazole and block copolymer (B-3) by precipitation method)
84.6 mg of the block copolymer (B-3) and 0.5 mL of DMSO as the first organic solvent were added to a 10 mL eggplant flask, and the mixture was stirred to obtain a uniform solution. To the obtained uniform solution, 85.6 mg of 2-methylimidazole (2-MIm) as a compound having a basic nitrogen atom was added and stirred. The solution that became uniform after stirring was added dropwise to 25 mL of acetonitrile, and the mixture was stirred for 17 hours. After stirring, the mixture was filtered using a membrane filter (0.2 μm). Washing with acetonitrile multiple times, filtering, pre-drying, heating under reduced pressure drying (75 ° C.), yielding a complex (C-4) of 2-methylimidazole and block copolymer (B-3). It was obtained at 25.1 mg and a yield of 15%.

(Example 5: Preparation of complex (C-5) of 1,2-dimethylimidazole and block copolymer (B-3) by precipitation method)
The amount of block copolymer (B-3) used was changed from 84.6 mg to 85.7 mg, and 85.6 mg of 2-methylimidazole (2-MIm) was changed to 1,2-dimethylimidazole (1,2-DIm). The yield of the complex (C-5) of 1,2-dimethylimidazole and the block copolymer (B-3) was 36.0 mg and the yield was the same as in Example 4 except that the amount was changed to 85.9 mg. Obtained at 21%.

(Example 6: Preparation of a complex (C-6) of 1-benzyl-2-methylimidazole and a block copolymer (B-3) by a precipitation method)
With 1,2-dimethylimidazole in the same manner as in Example 4, except that 85.6 mg of 2-methylimidazole (2-MIm) was changed to 85 mg of 1-benzyl-2-methylimidazole (1-B-2MIm). A complex (C-6) with the block copolymer (B-3) was obtained in a yield of 33.8 mg and a yield of 20%.

[Evaluation]
1. 1. Calculation of Encapsulation Ratio For the obtained complexes of Examples 1 to 6, the ratio of compounds having basic nitrogen atoms in each complex (having basic nitrogen atoms contained in the complex) using ¹ H-NMR. Compound / complex) was determined as a percentage, and this was taken as the inclusion ratio. The results are shown in Table 1.
2. 2. Measurement of Average Particle Size The average particle size of the obtained composites of Examples 1 to 6 was determined by dynamic light scattering (DLS). The results are shown in Table 1.
3. 3. Measurement of glass transition point Using 5 mg of the obtained composite of Examples 1 to 6, differential scanning calorimetry (DSC measurement) was performed in a temperature range of -20 ° C to 250 ° C in a nitrogen atmosphere, and the glass transition point Tg. Was measured. The results are shown in Table 1.
4. Evaluation as a Latent Curing Agent The curing reaction with the epoxy resin was examined using the obtained composites of Examples 1 to 6. 50 mg of bisphenol F type epoxy resin and 5 mg of the composite of Examples 1 to 6 (10% by mass based on the epoxy resin) are mixed, and DSC measurement is performed in a temperature range of 0 ° C. to 300 ° C. under a nitrogen atmosphere. , Curing start temperature (Tci), exothermic peak top temperature (Ttop), and exothermic enthalpy (ΔH) were determined. The results are shown in Table 2.

As described above, the complex of the present invention has been shown to be useful as a latent curing agent. Further, in the second block structure, the composite of Example 1 containing a structural unit derived from a compound having a hydrophilic group and a structural unit derived from an alkyl (meth) acrylate is hydrophilic in the second block structure. The curing start temperature (Tci) was about 10 ° C. lower than that of the complex of Example 2 consisting of only the structural units derived from the compound having a group. It is considered that this is because the density of hydrogen bonds is lowered and the aggregation enthalpy is reduced by containing the structural unit derived from the alkyl (meth) acrylate. From this, in the second block structure, it may be possible to adjust the curing start temperature (Tci) by adjusting the structural unit derived from the alkyl (meth) acrylate.

Claims (11)

Compounds with a basic nitrogen atom and
With block copolymers
Contains,
The block copolymer
A first block structure containing a structural unit derived from a compound having an acidic group and a structural unit derived from a compound having a hydrophobic group, and
A second block structure containing a structural unit derived from a compound having a hydrophilic group,
Have,
A complex in which the compound having a basic nitrogen atom is encapsulated in the block copolymer. The complex according to claim 1, wherein the structural unit derived from the compound having an acidic group is a structural unit represented by the following general formula (11).

[In the general formula (11), R ¹¹ represents a hydrogen atom or a methyl group, and R ¹² represents an acidic organic group. ] The complex according to claim 2, wherein R ¹² is a group represented by the following general formula (12).

[In the general formula (12), R ¹³ represents an alkyl group having 1 to 20 carbon atoms, and a represents an integer of 0 to 3. ] The complex according to any one of claims 1 to 3, wherein the structural unit derived from the compound having a hydrophobic group is a structural unit represented by the following general formula (21).

[In the general formula (21), R ²¹ represents a hydrogen atom or a methyl group, R ²² represents an alkyl group having 1 to 20 carbon atoms, and b represents an integer of 0 to 3. ] The complex according to any one of claims 1 to 4, wherein the structural unit derived from the compound having a hydrophilic group is the structural unit represented by the following general formula (31).

[In the general formula (31), R ³¹ represents a hydrogen atom or a methyl group. ] The complex according to any one of claims 1 to 5, wherein the second block structure further includes a structural unit represented by the following general formula (41).

[In the general formula (41), R ⁴¹ represents a hydrogen atom or a methyl group, and R ⁴² represents an alkyl group having 1 to 20 carbon atoms. ] The complex according to any one of claims 1 to 6, wherein the compound having a basic nitrogen atom is a compound having an imidazole skeleton, an imidazoline skeleton, a triazine skeleton, or an isocyanuric acid skeleton. The composite according to any one of claims 1 to 7, which is a latent curing agent for an epoxy resin. A curable resin composition containing an epoxy resin and the composite according to any one of claims 1 to 8. A compound having a basic nitrogen atom, a block copolymer, and a mixed solution containing a first organic solvent, and a second organic solvent are prepared, and the mixed solution is added to the second organic solvent to form a complex. With the process of obtaining
The block copolymer
A first block structure containing a structural unit derived from a compound having an acidic group and a structural unit derived from a compound having a hydrophobic group, and
A second block structure containing a structural unit derived from a compound having a hydrophilic group,
Have,
The complex is a method for producing a complex in which the compound having a basic nitrogen atom is contained in the block copolymer. A first mixed solution containing a compound having a basic nitrogen atom, a block copolymer, and a first organic solvent is prepared, and a hydrophilic solvent is added to the first mixed solution to add a second mixture. The process of obtaining a mixed solution and
A step of adding a second organic solvent to the second mixed solution to obtain a complex, and
With
The block copolymer
A first block structure containing a structural unit derived from a compound having an acidic group and a structural unit derived from a compound having a hydrophobic group, and
A second block structure containing a structural unit derived from a compound having a hydrophilic group,
Have,
The complex is a method for producing a complex in which the compound having a basic nitrogen atom is contained in the block copolymer.