JP5681942B2 - Water-based epoxy resin curing fine particles and method for producing water-based epoxy resin curing fine particles - Google Patents

Description

The present invention relates to a fine particle for curing an epoxy resin and a method for producing fine particles for curing an epoxy resin, which is used as a curing agent for an epoxy resin, has excellent dispersibility with respect to an aqueous epoxy resin, and can improve the reliability of a cured product.

Epoxy resins are used in various applications such as adhesives, sealants, and coating agents. Generally, a curing agent is added to the epoxy resin as a component for causing the curing reaction to proceed, and a curing accelerator is added as a component for improving the curability. In particular, in order to make the curing agent or the curing accelerator and the epoxy resin into one liquid, a latent curing agent or curing accelerator is frequently used.

For example, Patent Document 1 discloses a curing agent (I) having a predetermined powdery amine compound (A) as a core and a reaction product of the amine compound (A) and the epoxy resin (B) as a shell, and a predetermined amount. A master batch type curing agent for a one-component epoxy resin blended product comprising the epoxy resin (B) is described. However, the master batch type curing agent for a one-component epoxy resin compounded product described in Patent Document 1 has a problem that it is inferior in curability at a low temperature. In recent years, especially in the field of electronic equipment, there is a strong demand to further improve curability at low temperatures without compromising the storage stability of the curing agent in order to cope with higher circuit density and improve connection reliability. It has been.

In Patent Document 2, the surface of the core made of a predetermined curing agent for epoxy resin (C) mainly composed of an amine adduct (A) and a low molecular amine compound (B) is formed on a synthetic resin and / or an inorganic oxide. A microcapsule type epoxy resin curing agent having a structure covered with a shell made of is described. However, with the microcapsule-type epoxy resin curing agent described in Patent Document 2, it is difficult to achieve a small average particle size with little variation, which is required particularly in the field of electronic equipment.

Furthermore, the curing agent for epoxy resins described in Patent Documents 1 and 2 is a powder obtained by reacting an amine curing agent and an epoxy resin to an intermediate stage, and contact between the amine curing agent and the epoxy resin. The interface is only cured. For this reason, such a curing agent for an epoxy resin is likely to undergo a curing reaction with time, and it is difficult to obtain sufficient storage stability.

In order to improve the storage stability, for example, research has been conducted on a base generator that generates a basic compound by light irradiation and exhibits a catalytic activity for curing an epoxy resin.
For example, Patent Document 3 describes a base generation method in which a predetermined amine imide compound is irradiated with light of 150 to 750 nm to generate a base. Patent Document 3 describes that according to the method described in the document, an epoxy resin can be cured at low temperature and a curable composition having excellent storage stability can be provided.

On the other hand, in recent years, water-based epoxy resins that have low environmental impact and high work safety are attracting attention due to environmental problems or increasing social demands for safety.
However, conventional base generators are oil-soluble, have low solubility in water-based epoxy resins, and have poor dispersibility, so that a uniform and highly reliable cured product is formed using such base generators. It is difficult to do. In addition, if an organic solvent is used to dissolve the base generator, the intended use of the water-based epoxy resin, such as reducing the environmental burden or ensuring safety, cannot be sufficiently achieved. Accordingly, there is a need for a new epoxy resin curing agent that has performances required for epoxy resin curing agents, such as storage stability and low-temperature curability, and that is compatible with aqueous epoxy resins.

JP-A-1-70523 JP 2007-204670 A JP 2006-328427 A

The present invention provides a fine particle for curing an epoxy resin and a method for producing fine particles for curing an epoxy resin, which are used as a curing agent for an epoxy resin, have excellent dispersibility in an aqueous epoxy resin, and can improve the reliability of a cured product. With the goal.

The present invention is a fine particle for curing an epoxy resin having a group capable of generating a base by active energy rays or heat on the surface, and the main component is a monomer having a structure represented by the following general formula (1) in an aqueous medium. It is the fine particle for epoxy resin hardening obtained by polymerizing the radically polymerizable monomer to make.

In general formula (1), X represents a hydrogen atom or a methyl group, and A represents a group in which a base is generated by active energy rays or heat.
The present invention is described in detail below.

The inventors of the present invention provide a radical polymerizable monomer having a monomer having a predetermined structure in an aqueous medium, which is a fine particle for curing an epoxy resin having a group capable of generating a base by active energy rays or heat on its surface. It has been found that epoxy resin curing fine particles obtained by polymerizing can be suitably used as a curing agent for epoxy resins. The present inventors have found that the epoxy resin curing fine particles can be uniformly dispersed in the water-based epoxy resin and can improve the reliability of the cured product, and have completed the present invention.

The fine particles for curing an epoxy resin of the present invention have groups on the surface of which a base is generated by active energy rays or heat.
The group which generates a base by the active energy ray or heat decomposes when irradiated with an active energy ray or is heated, and generates a base. Since the generated base reacts with the epoxy resin as a curing agent to form a cured product, the epoxy resin curing fine particles of the present invention have epoxy groups by having a group that generates the base by the active energy ray or heat. It is suitably used as a resin curing agent. In addition, since the active energy ray or a group that generates a base by heat is decomposed only when the active energy ray is irradiated or heated, the epoxy resin curing fine particles of the present invention are added to the epoxy resin composition. However, the storage stability of the epoxy resin composition is not lowered.

Examples of the active energy ray include light such as infrared rays, visible rays, and ultraviolet rays, radiation such as X-rays and γ rays, and ion beams.
Moreover, it is preferable that the group which produces | generates a base with the said active energy ray or a heat | fever decomposes | disassembles, when a base produces | generates with a heat | fever, when heated to temperature, such as 100 degreeC, and produces | generates a base.

Although the group which a base produces | generates by the said active energy ray or a heat | fever is not specifically limited, a base is represented by the active energy ray represented by the following general formula (2), (3), (4), (5) or (6). It preferably has a structure to be generated.

In general formula (2), p is 0 or 1, R ¹ represents a divalent linking group, R ² and R ³ represent an aliphatic hydrocarbon group or an aromatic hydrocarbon group, R ² and R Any one of ³ represents an aromatic hydrocarbon group.

In general formula (3), R ¹ and R ⁶ represent a divalent linking group, R ⁴ and R ⁵ represent an aliphatic hydrocarbon group, and Ar ¹ represents an aromatic carbon which may have a substituent. Represents a hydrogen group.
The substituent for Ar ¹ is not particularly limited, and examples thereof include a nitro group, an alkoxy group, a hydroxy group, and a benzoyl group.

In General Formula (4), R ¹ represents a divalent linking group, and Ar ² and Ar ³ represent an aromatic hydrocarbon group or an aromatic carbonyl group.

In General Formula (5), R ¹ and R ⁶ represent a divalent linking group, and Ar ¹ represents an aromatic hydrocarbon group which may have a substituent.
The substituent for Ar ¹ is not particularly limited, and examples thereof include a nitro group, an alkoxy group, a hydroxy group, and a benzoyl group.

In General Formula (6), R ¹ represents a divalent linking group, R ⁷ and R ⁸ represent a hydrogen atom or a methyl group, and Ar ⁴ represents a hydroxyphenyl group.

The fine particles for curing an epoxy resin of the present invention can be obtained by polymerizing a radical polymerizable monomer whose main component is a monomer having a structure represented by the following general formula (1) in an aqueous medium.

In general formula (1), X represents a hydrogen atom or a methyl group, and A represents a group in which a base is generated by active energy rays or heat.

The monomer having the structure represented by the general formula (1) is not particularly limited. For example, the active energy represented by the general formula (2), (3), (4), (5) or (6) Examples include a base-generating unsaturated compound having a structure in which a base is generated by a line.
Specifically as a base generation unsaturated compound which has a structure which a base produces | generates with the active energy ray represented by the said General formula (2), for example, following formula (2-1), (2-2) or ( And a base-generating unsaturated compound having a structure represented by 2-3).

As a base generation unsaturated compound which has a structure which a base produces | generates by the active energy ray represented by the said General formula (3), specifically, for example, a base having a structure represented by the following formula (3-1) Examples include generated unsaturated compounds.

Specifically as a base generation unsaturated compound which has a structure which a base produces | generates with the active energy ray represented by the said General formula (4), specifically, following formula (4-1), (4-2), ( 4-3) or a base-generating unsaturated compound having a structure represented by (4-4).

Specifically as a base generation unsaturated compound which has a structure which a base produces | generates by the active energy ray represented by the said General formula (5), specifically, it represents with following formula (5-1) or (5-2), for example. And a base-generating unsaturated compound having a structure as described above. Moreover, as a base generation unsaturated compound which has a structure which a base produces | generates with the active energy ray represented by the said General formula (6), specifically, for example, the structure represented by the following formula (6-1): And a base-generating unsaturated compound.

As the monomer having the structure represented by the general formula (1), for example, a base-generating unsaturated compound having a structure represented by the following formulas (a) to (w) can also be used.

The radical polymerizable monomer is not particularly limited as long as the monomer having the structure represented by the general formula (1) is a main component, and may contain another radical polymerizable monomer as necessary.
The other radical polymerizable monomer is not particularly limited, and examples thereof include a carboxyl group-containing monomer, a nitrile monomer, an acrylic ester monomer, a methacrylic ester monomer, and a vinyl monomer. Among these other radical polymerizable monomers, hydrophilic monomers such as carboxyl group-containing monomers are preferable.

The carboxyl group-containing monomer is not particularly limited, and examples thereof include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, ethacrylic acid, crotonic acid, and cinnamic acid, maleic acid, itaconic acid, fumaric acid, citraconic acid, and the like. Saturated dicarboxylic acid etc. are mentioned.
The nitrile monomer is not particularly limited, and examples thereof include acrylonitrile and methacrylonitrile.

The acrylate monomer is not particularly limited, and examples thereof include methyl acrylate, ethyl acrylate, butyl acrylate, and dicyclopentenyl acrylate.
The methacrylic acid ester monomer is not particularly limited, and examples thereof include methyl methacrylate, ethyl methacrylate, butyl methacrylate, and isobornyl methacrylate.
The vinyl monomer is not particularly limited, and examples thereof include vinyl chloride, vinylidene chloride, vinyl acetate, styrene, and divinylbenzene.

When the radical polymerizable monomer contains the other radical polymerizable monomer, the blending amount of the other radical polymerizable monomer is not particularly limited, but the structure represented by the general formula (1) which is the main component is used. A preferred upper limit for 100 parts by weight of the monomer is 50 parts by weight. When the blending amount of the other radical polymerizable monomer exceeds 50 parts by weight, the resulting epoxy resin curing fine particles have fewer groups that generate a base due to the active energy rays or heat on the surface, and function as a curing agent. May not be possible.

Furthermore, when polymerizing the radical polymerizable monomer, a water-soluble polymer, an emulsifier, a dispersant and the like may be used.
The water-soluble polymer is not particularly limited. For example, polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), polyethylene oxide, gum arabic, gelatin, glycerin, alkyl cellulose, hydroxy-alkyl cellulose, carboxyalkyl cellulose, polyacrylamide, Examples include polyacrylic acid and polymethacrylic acid.

A blending amount of the water-soluble polymer is not particularly limited, but a preferable lower limit with respect to 100 parts by weight of the radical polymerizable monomer is 0.001 part by weight, and a preferable upper limit is 5 parts by weight. When the blending amount of the water-soluble polymer is less than 0.001 part by weight, the dispersion stabilizing effect by using the water-soluble polymer may not be sufficiently obtained. When the amount of the water-soluble polymer exceeds 5 parts by weight, the water-soluble polymer adsorbed on the surface of the resulting epoxy resin curing fine particles or the non-adsorbed water-soluble polymer may cause cross-linking aggregation. There is.

The emulsifier is not particularly limited, and examples thereof include alkyl sulfate sulfonate, alkyl benzene sulfonate, alkyl sulfate triethanolamine, polyoxyethylene alkyl ether, and polyvinyl alcohol.

Although the compounding quantity of the said emulsifier is not specifically limited, The preferable minimum with respect to 100 weight part of said radically polymerizable monomers is 0.01 weight part, and a preferable upper limit is 10 weight part. If the amount of the emulsifier is less than 0.01 parts by weight, the particle diameter of the resulting epoxy resin curing fine particles may not be sufficiently reduced, and the formed epoxy resin curing fine particles may aggregate. May end up. When the amount of the emulsifier exceeds 10 parts by weight, the particle purity of the resulting epoxy resin curing fine particles may be lowered.

As said dispersing agent, inorganic powder etc. are mentioned, for example.
The blending amount of the dispersant is not particularly limited, but a preferable lower limit with respect to 100 parts by weight of the radical polymerizable monomer is 0.001 part by weight, and a preferable upper limit is 5 parts by weight.

The aqueous medium is not particularly limited as long as it is an aqueous medium usually used for polymerizing a radical polymerizable monomer, and examples thereof include water, alcohol, a mixture of water and alcohol, and the like.
Examples of the alcohol include methanol, ethanol, propanol, isopropanol, t-butanol, and the like.

The polymerization method is not particularly limited, and examples thereof include a polymerization method by emulsion polymerization, suspension polymerization, dispersion polymerization, soap-free polymerization and the like.

When the emulsion polymerization or the suspension polymerization is used, the epoxy resin curing fine particles of the present invention are obtained, for example, as follows.
To the aqueous medium, the radical polymerizable monomer, the polymerization initiator, and the emulsifier or the water-soluble polymer are added, and oil droplets containing the radical polymerizable monomer are dispersed in the aqueous medium. The radical polymerizable monomer is polymerized to obtain fine particles for curing the epoxy resin of the present invention. In order to disperse the oil droplets in the aqueous medium, generally an emulsifier is used in emulsion polymerization, and a water-soluble polymer and / or a dispersant is used in suspension polymerization.
In the emulsion polymerization and the suspension polymerization, a polymerization initiator may be added to the aqueous medium together with the radical polymerizable monomer and the like, and after the radical polymerizable monomer and the like are added to the aqueous medium in advance. When the radical polymerizable monomer is polymerized, it may be added to the aqueous medium. In the emulsion polymerization, the polymerization initiator is hydrophilic, and in the suspension polymerization, the polymerization initiator is lipophilic.

When the dispersion polymerization is used, the epoxy resin curing fine particles of the present invention are obtained, for example, as follows.
In the aqueous medium, the radical polymerizable monomer, the hydrophilic or lipophilic polymerization initiator, and the water-soluble polymer and / or the emulsifier are dissolved, and then the radical polymerizable monomer is polymerized to obtain a polymer. Precipitate. The polymer is agglomerated in the aqueous medium to form particles, whereby the epoxy resin curing fine particles of the present invention are obtained.

When using the soap-free polymerization, the epoxy resin curing fine particles of the present invention are obtained, for example, as follows.
The radical polymerizable monomer and the hydrophilic polymerization initiator are added to the aqueous medium, and oil droplets containing the radical polymerizable monomer are dispersed in the aqueous medium, and then dissolved in the aqueous medium. The above radical polymerizable monomers are sequentially polymerized to precipitate a polymer. The polymer is agglomerated in the aqueous medium to form particles, whereby the epoxy resin curing fine particles of the present invention are obtained.

The lipophilic polymerization initiator is not particularly limited, and examples thereof include benzoyl peroxide, diisopropyl peroxycarbonate, dioctyl peroxydicarbonate, t-butyl peroxylaurate, lauroyl peroxide, dioctanoyl peroxide, and the like. Oxides, azobisisobutyronitrile, azobis (2,4-dimethylvaleronitrile), 1,1-azobis (cyclohexane-1-carbonitrile), dimethyl 2,2-azobis (2-methylpropionate), etc. And the like. These polymerization initiators may be used independently and 2 or more types may be used together.

Examples of the hydrophilic polymerization initiator include peroxides and azo compounds.
The peroxide is not particularly limited. For example, hydrogen peroxide, acetyl peroxide, cumyl peroxide, t-butyl peroxide, propionyl peroxide, benzoyl peroxide, chlorobenzoyl peroxide, dichlorobenzoyl peroxide, peroxide Bromomethylbenzoyl, lauroyl peroxide, ammonium persulfate, sodium persulfate, potassium persulfate, diisopropyl peroxycarbonate, tetralin hydroperoxide, 1-phenyl-2-methylpropyl-1-hydroperoxide, t-butyl hydroperoxide pertriphenylacetate , T-butyl formate, t-butyl peracetate, t-butyl perbenzoate, t-butyl perphenyl acetate, t-butyl permethoxyacetate, t-butyl per-N- (3-toluyl) carbamate, ammonium bisulfate And sodium bisulfate.
The azo compound is not particularly limited. For example, 2,2′-azobis (2-amidinopropane), 2,2′-azobis (N, N′-dimethyleneisobutylamidine), 2,2′-azobis [2 -(5-methyl-2-imidazolin-2-yl) propane], 1,1'-azobis (1-amidino-1-cyclopropylethane), 2,2'-azobis (2-amidino-4-methylpentane) ), 2,2′-azobis (2-N-phenylaminoamidinopropane), 2,2′-azobis (1-imino-1-ethylamino-2-methylpropane), 2,2′-azobis (1- Allylamino-1-imino-2-methylbutane), 2,2′-azobis (2-N-cyclohexylamidinopropane), 2,2′-azobis (2-N-benzylamidinopropane) and its hydrochloric acid, sulfuric acid 4,4′-azobis (4-cyanovaleric acid) and its alkali metal salts, ammonium salts, amine salts, 2- (carbamoylazo) isobutyronitrile, 2,2′-azobis (isobutyramide) ), 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) propionamide], 2,2′-azobis [2-methyl-N- (1,1′-bis (hydroxymethyl) ethyl] ) Propionamide], 2,2′-azobis [2-methyl-N-1,1′-bis (hydroxyethyl) propionamide], 2,2′-azobis [N- (2-carboxyethyl) -2- Methyl propionamide] and the like.
These polymerization initiators may be used independently and 2 or more types may be used together.

Since the epoxy resin curing fine particles of the present invention are obtained by polymerizing a radically polymerizable monomer whose main component is a monomer having a structure represented by the general formula (1) in an aqueous medium as described above, The hydrophilicity of the surface is so high that it can be uniformly dispersed in the water-based epoxy resin, and it can be uniformly dispersed in the water-based epoxy resin, forming a uniform cured product, and improving the reliability of the cured product. Can be increased.
The reason why the hydrophilicity of the surface of the epoxy resin curing fine particles is increased as described above is, for example, that the emulsifier, the water-soluble polymer or the dispersant is adsorbed on the surface of the epoxy resin curing fine particles, When the dispersion polymerization or the soap-free polymerization is used and the radical polymerizable monomer contains the hydrophilic monomer, the precipitated polymer may be aggregated with the hydrophilic group facing outward.

The fine particles for curing an epoxy resin of the present invention are obtained by polymerizing a radically polymerizable monomer whose main component is a monomer having a structure represented by the general formula (1), so that the active energy ray or heat is applied to the surface. Can be used as a curing agent for epoxy resins.
The epoxy resin curing fine particles of the present invention preferably have a segment derived from a monomer having a structure represented by the general formula (1). Furthermore, it is more preferable that the epoxy resin curing fine particles of the present invention have a segment derived from the monomer having the structure represented by the general formula (1) and a segment derived from the hydrophilic monomer. Thereby, the hydrophilic property of the surface is increased, and the dispersibility with respect to the water-based epoxy resin is further improved.

The number average particle size of the epoxy resin curing fine particles of the present invention is not particularly limited, but a preferable lower limit is 0.03 μm and a preferable upper limit is 0.5 μm. If the number average particle diameter of the epoxy resin curing fine particles of the present invention is less than 0.03 μm, the resulting epoxy resin curing fine particles may easily aggregate. When the number average particle diameter of the epoxy resin curing fine particles of the present invention exceeds 0.5 μm, the epoxy resin curing fine particles block the active energy rays even if the resulting epoxy resin curing fine particles are irradiated with active energy rays. In some cases, sufficient curing cannot be performed. The more preferable lower limit of the number average particle diameter of the epoxy resin curing fine particles of the present invention is 0.05 μm, and the more preferable upper limit is 0.3 μm.

In the present specification, the number average particle size of the epoxy resin curing fine particles means a value measured by a dynamic light scattering particle size distribution analyzer (manufactured by Particle Sizing Systems, "NICOMP model 380 ZLS-S"). .

The use of the epoxy resin curing fine particles of the present invention is not particularly limited, but as described above, the use as a curing agent for epoxy resin is preferable, and from the viewpoint of high dispersibility with respect to the aqueous epoxy resin, the curing reaction of the aqueous epoxy resin is performed. The use as a curing agent for epoxy resin for progressing is more preferable.
As described above, the epoxy resin curing fine particles of the present invention are excellent in dispersibility with respect to the aqueous epoxy resin because the epoxy resin curing fine particles of the present invention are represented by the general formula (1) in the aqueous medium. This is because it is obtained by polymerizing a radically polymerizable monomer whose main component is a monomer having the structure represented.
A method for producing fine particles for curing an epoxy resin having a group capable of generating a base by active energy rays or heat on a surface, the main component being a monomer having a structure represented by the general formula (1) in the aqueous medium A method for producing fine particles for curing an epoxy resin by polymerizing the radical polymerizable monomer is also one aspect of the present invention.

ADVANTAGE OF THE INVENTION According to this invention, it is used as a hardening | curing agent for epoxy resins, provides the manufacturing method of the fine particle for epoxy resin hardening which is excellent in the dispersibility with respect to a water-based epoxy resin, and can improve the reliability of hardened | cured material, and the fine particle for epoxy resin hardening can do.

Examples of the present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

(Example 1)
In a 500 mL round bottom separable flask, 1.5 g of polyvinylpyrrolidone, 150 g of methanol, and (9H-fluoren-9-yl) methyl 2- (methacryloyloxy) as a monomer having a structure represented by the general formula (1) And 4.0 g of ethyl carbamate (a base-generating unsaturated compound having a structure in which a base is generated by autocatalytic decomposition by the action of a base) was added, and the inside of the flask was placed in a nitrogen atmosphere while stirring. Thereafter, a polymerization initiator solution obtained by dissolving 0.74 g of azobisisobutyronitrile in 10 g of methanol as a lipophilic polymerization initiator was added, and polymerization was carried out at 50 ° C. to obtain fine particles. The obtained fine particles were washed with methanol and dried under reduced pressure to obtain fine particles for epoxy resin curing (number average particle size 1.17 μm).

(Example 2)
In a 500 mL round bottom separable flask, 1.5 g of polyvinylpyrrolidone, 150 g of methanol, and 4,5-dimethoxy-2-nitrobenzyl 2- (methacryloyloxy) as a monomer having a structure represented by the general formula (1) ) 4.0 g of ethyl carbamate (base-generating unsaturated compound having a structure in which a base is generated by light) was added, and the inside of the flask was placed in a nitrogen atmosphere while stirring. Thereafter, a polymerization initiator solution obtained by dissolving 0.74 g of azobisisobutyronitrile in 10 g of methanol as a lipophilic polymerization initiator was added, and polymerization was carried out at 50 ° C. to obtain fine particles. The obtained fine particles were washed with methanol and dried under reduced pressure to obtain fine particles for epoxy resin curing (number average particle size 1.17 μm).

Example 3
In a 500 mL round bottom separable flask, 1.5 g of polyvinylpyrrolidone, 150 g of methanol, and (9H-fluoren-9-yl) methyl 2- (methacryloyloxy) as a monomer having a structure represented by the general formula (1) ) 2.0 g of ethyl carbamate (monomer having a structure in which a base is generated by autocatalytic decomposition by the action of a base) and 4,5-dimethoxy-2-nitrobenzyl 2- (methacryloyloxy) ethyl carbamate (base by light (Monomer having a structure in which is formed) was added, and the inside of the flask was placed in a nitrogen atmosphere while stirring. Thereafter, a polymerization initiator solution obtained by dissolving 0.74 g of azobisisobutyronitrile in 10 g of methanol as a lipophilic polymerization initiator was added, and polymerization was carried out at 50 ° C. to obtain fine particles. The obtained fine particles were washed with methanol and dried under reduced pressure to obtain fine particles for epoxy resin curing (number average particle size 1.17 μm).

(Comparative Example 1)
Non-particulate (9H-fluoren-9-yl) methyl 2- (methacryloyloxy) ethylcarbamate (a monomer having a structure in which a base is generated by the action of a base to generate a base) was used as it was. .

(Evaluation)
The following evaluation was performed about the fine particle for epoxy resin hardening obtained in the Example, and the homopolymer obtained in the comparative example. The results are shown in Table 1.

(1) Dispersibility with respect to water-based epoxy resin 10 parts by weight of the obtained epoxy resin curing fine particles or homopolymer, and 15 parts by weight of water-based epoxy resin (EX-512, manufactured by Nagase ChemteX Corporation) are stirred and mixed using a homodisper. An epoxy resin composition was prepared.
The obtained epoxy resin composition was applied to a thickness of 500 μm and heated at 100 ° C. for 120 minutes. After removing the uncured portion of the epoxy resin composition after heating with ethyl methyl ketone, the epoxy resin composition was vacuum dried. By observing the cross section of the epoxy resin composition after drying with a scanning electron microscope, the dispersibility of the epoxy resin curing fine particles or homopolymer in the aqueous epoxy resin was evaluated.
The case where the cavity of the uncured part was not seen was marked with ◯, and the case where the cavity of the uncured part was confirmed was marked with x. If the epoxy resin curing fine particles or homopolymer is not uniformly dispersed, an uncured portion remains, and the uncured portion is eluted with ethyl methyl ketone, resulting in a void in the uncured portion.

(2) Reliability of cured product For each epoxy resin curing fine particle or homopolymer, each epoxy resin composition was prepared as follows in order to match the base generation amount.
The epoxy resin composition 0.6 g of the epoxy resin curing fine particle obtained in Example 1 and 0.1 g of a water-soluble epoxy resin (EX-512, manufactured by Nagase ChemteX Corporation) were stirred and mixed to obtain an epoxy resin composition. A product was prepared. Further, 0.1 g of a 30 wt% dispersion of the epoxy resin curing fine particles obtained in Example 2 and 0.1 g of a water-soluble epoxy resin (EX-512, manufactured by Nagase ChemteX Corp.) were mixed with stirring to prepare an epoxy. A resin composition was prepared. Further, 0.3 g of a 40% by weight dispersion of epoxy resin curing fine particles obtained in Example 3 and 0.05 g of a water-soluble epoxy resin (EX-512, manufactured by Nagase ChemteX Corporation) were mixed with stirring to obtain an epoxy. A resin composition was prepared. Further, 0.01 g of the homopolymer obtained in Comparative Example 1, 0.2 g of a water-soluble epoxy resin (EX-512, manufactured by Nagase ChemteX Corporation), 0.5 g of PVA, and 0.2 g of methanol were mixed with stirring. An epoxy resin composition was prepared.

The obtained epoxy resin composition is bar-coated on a glass substrate to prepare a coating film. The coating film is irradiated with light having a wavelength of 365 nm of 1000 mJ / cm ² and then heated at 120 ° C. for 30 minutes. It was. The hardness of the obtained cured film was evaluated by a pencil hardness test. In the pencil hardness test, the cured film was scratched with a pencil, and a state in which scratches of 3 mm or more were included was regarded as a defect, and the hardest pencil hardness without scratches was evaluated. The higher the pencil hardness, the higher the reliability of the cured product. In addition, about the epoxy resin composition of the comparative example 1, nonuniform hardening occurred and it did not reach the film | membrane to evaluate.

(3) Storage stability The obtained epoxy resin curing fine particles or homopolymer and bisphenol A type epoxy resin (JER828, manufactured by Japan Epoxy Resin Co., Ltd.) are mixed at a weight ratio of 5:10, and 300 g of the epoxy resin composition is mixed. After the preparation, the viscosity (Pa · s) at 25 ° C. of the obtained epoxy resin composition was measured with a B-type viscometer. Thereafter, the viscosity (Pa · s) after the epoxy resin composition was allowed to stand at 25 ° C. for 30 days in a light-shielded thermostatic chamber was measured.
The storage stability was evaluated by calculating the difference in viscosity between before and after storage (25 ° C., before and after standing for 30 days).

ADVANTAGE OF THE INVENTION According to this invention, it is used as a hardening | curing agent for epoxy resins, provides the manufacturing method of the fine particle for epoxy resin hardening which is excellent in the dispersibility with respect to a water-based epoxy resin, and can improve the reliability of hardened | cured material, and the fine particle for epoxy resin hardening can do.

Claims (4)

Water-based epoxy resin curing fine particles for proceeding the curing reaction of the water-based epoxy resin having a group that generates a base by active energy rays or heat on the surface,
In an aqueous medium, a radically polymerizable monomer containing 2/3 or more by weight of a monomer having a structure represented by the following general formula (1) is polymerized by emulsion polymerization, suspension polymerization, dispersion polymerization, or soap-free polymerization. Fine particles for curing an aqueous epoxy resin, characterized by being obtained by

In general formula (1), X represents a hydrogen atom or a methyl group, and A represents a group in which a base is generated by active energy rays or heat. The group in which a base is generated by active energy rays or heat has a structure in which a base is generated by active energy rays represented by the following general formula (2), (3), (4), (5) or (6). The fine particles for curing an aqueous epoxy resin according to claim 1.

In general formula (2), p is 0 or 1, R ¹ represents a divalent linking group, R ² and R ³ represent an aliphatic hydrocarbon group or an aromatic hydrocarbon group, R ² and R Any one of ³ represents an aromatic hydrocarbon group.

In general formula (3), R ¹ and R ⁶ represent a divalent linking group, R ⁴ and R ⁵ represent an aliphatic hydrocarbon group, and Ar ¹ represents an aromatic carbon which may have a substituent. Represents a hydrogen group.

In General Formula (4), R ¹ represents a divalent linking group, and Ar ² and Ar ³ represent an aromatic hydrocarbon group or an aromatic carbonyl group.

In General Formula (5), R ¹ and R ⁶ represent a divalent linking group, and Ar ¹ represents an aromatic hydrocarbon group which may have a substituent.

In General Formula (6), R ¹ represents a divalent linking group, R ⁷ and R ⁸ represent a hydrogen atom or a methyl group, and Ar ⁴ represents a hydroxyphenyl group. The fine particles for curing an aqueous epoxy resin according to claim 1 or 2, wherein an emulsifier, a water-soluble polymer or a dispersant is adsorbed on the surface. A method for producing fine particles for curing an aqueous epoxy resin having a group that generates a base by active energy rays or heat on the surface, for proceeding with a curing reaction of the aqueous epoxy resin,
In an aqueous medium, a radically polymerizable monomer containing 2/3 or more by weight of a monomer having a structure represented by the following general formula (1) is polymerized by emulsion polymerization, suspension polymerization, dispersion polymerization, or soap-free polymerization. A method for producing fine particles for curing a water-based epoxy resin.

In general formula (1), X represents a hydrogen atom or a methyl group, and A represents a group in which a base is generated by active energy rays or heat.