JP2012031288A - Epoxy resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin cured product of high toughness characteristic.SOLUTION: The present invention discloses a novel epoxy resin composition obtained by adding a resin fine particle containing an acrylonitrile polymer as a principal component to a non-fiber-reinforced epoxy resin cured product, in the epoxy resin cured product comprising an epoxy resin and a curing agent, and a cured product thereof, The epoxy resin cured product has an effect of enhancing a toughness of the epoxy resin cured product, while keeping a strength characteristic that is a characteristic of the epoxy resin cured product. The epoxy resin cured product can improve, in particular, a demerit in thermal expansion that is a problem to be solved in a conventional epoxy resin cured product added with a rubber polymer fine particle.

Description

  The present invention relates to an epoxy resin composition.

  Epoxy resins have low curing shrinkage as liquid polymer materials and are excellent in heat resistance, adhesion, water resistance, mechanical strength, electrical properties, etc., so adhesives, paints, civil engineering and building materials, It is used as an insulating material for electronic parts and a carbon fiber reinforced composite material.

  However, cured products of epoxy resins have low fracture toughness and can exhibit very brittle properties, and such characteristics often become a problem in a wide range of applications.

  As one method for solving these problems, a method of blending and curing a rubber component in an epoxy resin composition is disclosed (Patent Documents 1, 2, and 3).

  Usually, as the rubbery component, it is common to use a particulate material obtained by polymerizing in a medium as represented by emulsion polymerization, suspension polymerization, dispersion polymerization, and precipitation polymerization. For the purpose of improving dispersibility, a core-shell structure is used, a diene copolymer, chloroprene copolymer, etc. are used as a soft layer as a core layer, and a layer for improving dispersibility in epoxy resin is provided as a shell layer. It is common to do.

  These methods are good methods for improving the toughness of the epoxy resin, but at the same time the toughness is improved, the mechanical strength of the original epoxy resin is reduced, the molding failure due to volume expansion, etc. There is a problem.

  Moreover, in order to improve the dispersibility in an epoxy resin, since it is necessary to provide a special shell layer, there exists a subject that particle manufacture becomes very complicated.

  Therefore, a new toughening method other than the conventionally known rubber particle addition method has been desired.

International Publication No. 2006/19041 JP 2009-24969 A Special table 2009-506169

  That is, an object of the present invention is to provide an epoxy resin composition for obtaining an epoxy resin cured product excellent in toughness without reducing the mechanical strength of the cured epoxy resin and having a small volume change upon heating, and the cured product thereof. There is to do.

  As a result of intensive investigations, the present inventors have found that by adding acrylonitrile-based polymer fine particles to an epoxy resin, the toughness of the cured epoxy resin can be improved and a material with a small volume change upon heating can be obtained. And found that the above problems can be solved.

That is, the present invention
[1] An epoxy resin composition comprising acrylonitrile-based polymer fine particles in an epoxy resin,
[2] The epoxy resin composition according to [1], wherein the acrylonitrile-based polymer is a polymer containing 50% by mass or more of an acrylonitrile monomer unit,
[3] The epoxy resin composition according to [1] or [2], wherein the resin fine particles have an average particle diameter of 1 to 100 μm,
[4] The epoxy resin composition according to any one of [1] to [3], wherein the particle size distribution index of the resin fine particles is 1 to 3, and the sphericity is 80 or more,
[5] The epoxy resin composition according to any one of [1] to [4], comprising 1 to 50% by mass of resin fine particles,
[6] A cured epoxy resin obtained by curing the epoxy resin composition according to any one of [1] to [5] and a curing agent,
It is.

  According to the method of the present invention, it is possible to obtain an epoxy resin composition that can provide an epoxy resin cured product that has a small volume change upon heating, maintains strength properties, and is excellent in toughness, and a cured product thereof.

  The present invention can be widely applied to applications in which an epoxy resin is used. For example, the present invention can be applied to semiconductor encapsulants, LED encapsulants, adhesives, carbon fiber reinforced materials, and the like.

2 is an optical micrograph showing a fine particle dispersion state in a cured epoxy resin in which acrylonitrile-based polymer fine particles are dispersed in Example 1. FIG.

  The present invention will be described in more detail below.

<Epoxy resin>
As the epoxy resin, for example, a glycidyl ether type epoxy resin obtained from a compound having a hydroxyl group in the molecule and epichlorohydrin, a glycidylamine type epoxy resin obtained from a compound having an amino group in the molecule and epichlorohydrin, A glycidyl ester type epoxy resin obtained from a compound having a carboxyl group in the molecule and epichlorohydrin, an alicyclic epoxy resin obtained by oxidizing a compound having a double bond in the molecule, or 2 selected from these An epoxy resin or the like in which more than one type of group is mixed in the molecule is used.

  Specific examples of the glycidyl ether type epoxy resin include bisphenol A type epoxy resin obtained by reaction of bisphenol A and epichlorohydrin, bisphenol F type epoxy resin obtained by reaction of bisphenol F and epichlorohydrin, 4, 4 Bisphenol S type epoxy resin obtained by reaction of '-dihydroxydiphenylsulfone and epichlorohydrin, Resorcinol type epoxy resin obtained by reaction of resorcinol and epichlorohydrin, Phenol novolak obtained by reaction of phenol and epichlorohydrin Type epoxy resins, other polyethylene glycol type epoxy resins, polypropylene glycol type epoxy resins, naphthalene type epoxy resins, and their positional isomers, alkyl groups and halogens. Substitutions and the like.

  Commercially available bisphenol A type epoxy resins include “EPON” (registered trademark) 825, “jER” (registered trademark) 826, “jER” (registered trademark) 827, “jER” (registered trademark) 828 (above, Japan). Epoxy Resin Co., Ltd.), “Epicron” (registered trademark) 850 (Dainippon Ink Chemical Co., Ltd.), “Epototo” (registered trademark) YD-128 (Toto Kasei Co., Ltd.), DER-331 DER-332 (manufactured by Dow Chemical), “Bakelite” (registered trademark) EPR154, “Bakelite” (registered trademark) EPR162, “Bakelite” (registered trademark) EPR172, “Bakelite” (registered trademark) EPR173, and “Bakelite” "(Registered trademark) EPR174 (above, manufactured by Bakerite AG)" .

  Commercially available products of bisphenol F type epoxy resin include “jER” (registered trademark) 806, “jER” (registered trademark) 807, “jER” (registered trademark) 1750 (above, manufactured by Japan Epoxy Resin Co., Ltd.), “ “Epicron” (registered trademark) 830 (manufactured by Dainippon Ink & Chemicals, Inc.), “Epototo” (registered trademark) YD-170, “Epototo” (registered trademark) YD-175 (manufactured by Toto Kasei Co., Ltd.), “ Bakelite "(registered trademark) EPR169 (manufactured by Bakerite AG), GY281, GY282, and GY285 (manufactured by Huntsman Advanced Materials) and the like.

  Examples of commercially available resorcinol-type epoxy resins include “Denacol” (registered trademark) EX-201 (manufactured by Nagase ChemteX Corporation).

  Commercial products of phenol novolac type epoxy resins include “jER” (registered trademark) 152, “jER” (registered trademark) 154 (manufactured by Japan Epoxy Resin Co., Ltd.), “Epicron” (registered trademark) 740 (large) Nippon Ink Chemical Co., Ltd.), EPN179, EPN180 (above, manufactured by Huntsman Advanced Materials) and the like.

  Specific examples of the glycidylamine type epoxy resin include tetraglycidyldiaminodiphenylmethanes, glycidyl compounds of aminophenol, glycidylanilines, and glycidyl compounds of xylenediamine.

  Commercially available tetraglycidyldiaminodiphenylmethanes include “Sumiepoxy” (registered trademark) ELM434 (manufactured by Sumitomo Chemical Co., Ltd.), “Araldite” (registered trademark) MY720, “Araldite” (registered trademark) MY721, “Araldite” ( (Registered trademark) MY9512, “Araldite” (registered trademark) MY9612, “Araldite” (registered trademark) MY9634, “Araldite” (registered trademark) MY9663 (manufactured by Huntsman Advanced Materials), “jER” (registered trademark) 604 (Made by Japan Epoxy Resin Co., Ltd.), “Bakelite” (registered trademark) EPR494, “Bakelite” (registered trademark) EPR495, “Bakelite” (registered trademark) EPR496, and “Bakelite” (registered trademark) EPR497 Or more, manufactured by Bakelite AG, Inc.), and the like.

  Commercially available products of aminophenol glycidyl compounds include “jER” (registered trademark) 630 (manufactured by Japan Epoxy Resin Co., Ltd.), “Araldite” (registered trademark) MY0500, “Araldite” (registered trademark) MY0510 (above Huntsman) Advanced Materials Co., Ltd., “Sumiepoxy” (registered trademark) ELM120, “Sumiepoxy” (registered trademark) ELM100 (manufactured by Sumitomo Chemical Co., Ltd.), and the like.

  Examples of commercially available glycidyl anilines include GAN, GOT (manufactured by Nippon Kayaku Co., Ltd.), “Bakelite” (registered trademark) EPR493 (manufactured by Bakelite AG), and the like.

  Examples of the glycidyl compound of xylenediamine include TETRAD-X (manufactured by Mitsubishi Gas Chemical Co., Inc.).

  Specific examples of the glycidyl ester type epoxy resin include phthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, isophthalic acid diglycidyl ester, dimer acid diglycidyl ester and various isomers thereof.

  Examples of commercial products of diglycidyl phthalate include “Epomic” (registered trademark) R508 (manufactured by Mitsui Chemicals) and “Denacol” (registered trademark) EX-721 (manufactured by Nagase ChemteX Corporation). It is done.

  Examples of commercially available hexahydrophthalic acid diglycidyl ester include “Epomic” R540 (manufactured by Mitsui Chemicals) and AK-601 (manufactured by Nippon Kayaku Co., Ltd.).

  Examples of commercially available dimer acid diglycidyl esters include “jER” (registered trademark) 871 (manufactured by Japan Epoxy Resin Co., Ltd.) and “Epototo” (registered trademark) YD-171 (manufactured by Toto Kasei Co., Ltd.). It is done.

  Commercially available alicyclic epoxy resins include “Celoxide” (registered trademark) 2021P (manufactured by Daicel Chemical Industries), CY179 (manufactured by Huntsman Advanced Materials), “Celoxide” (registered trademark) 2081 (Daicel). Chemical Industry Co., Ltd.) and “Celoxide” (registered trademark) 3000 (Daicel Chemical Industries, Ltd.). As these epoxy resins, bisphenol A type epoxy resins and the like are preferable from the viewpoint of heat resistance and toughness. The said epoxy resin can be used by 1 type, or 2 or more types.

  Preferred epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins and phenol novolac type epoxy resins, glycidyl ether type epoxy resins, tetraglycidyl diaminodiphenylmethanes and aminophenol glycidyl compounds. It is a certain glycidylamine type epoxy resin, and more preferable epoxy resins are bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins and glycidyl ether type epoxy resins which are phenol novolac type epoxy resins.

<Acrylonitrile polymer>
The acrylonitrile-based polymer in the present invention refers to a polymer having as a main component a unit having an acrylonitrile-based skeleton represented by the general formula (1) (hereinafter sometimes referred to as an acrylonitrile-based monomer unit).

In the above formula, R ¹ and R ² are any one selected from substituents such as a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a halogen group, a hydroxyl group, an alkoxyl group, an ester group, a carboxyl group, and a sulfonic acid group. Indicates. These may be the same or different. Among these, preferred are a hydrogen atom, a methyl group, an ethyl group, and an isopropyl group, more preferred are a hydrogen atom, a methyl group, and an ethyl group, and particularly preferred from the viewpoint of industrial availability. Is a hydrogen atom or a methyl group.

  Such a monomer as a raw material for the acrylonitrile-based monomer unit may be so-called vinyl cyanide, and preferred specific examples include acrylonitrile, methacrylonitrile, and chloroacrylonitrile. These can be used alone or in combination of two or more thereof. Most preferred is acrylonitrile.

  The acrylonitrile-based polymer in the present invention is mainly composed of the acrylonitrile-based monomer unit, for example, a polymer containing 50% by mass or more in the polymer, and a polymer containing 60% by mass or more. Is preferable, 70 mass% or more is more preferable, 90 mass% or more is particularly preferable. Further, the acrylonitrile monomer may be 100% by mass, that is, a homopolymer of acrylonitrile.

  By setting it within this range, it is possible to obtain a cured epoxy resin that has high toughness characteristics and has a small volume change upon heating.

  Other monomers that can be copolymerized with the acrylonitrile monomer include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, Acrylic acid such as propyl methacrylate, butyl methacrylate, hexyl methacrylate, esters of methacrylic acid, vinyl halides such as vinyl chloride, vinyl bromide, vinylidene chloride, methacrylic acid, acrylic acid, itaconic acid, Examples include acids such as crotonic acid, vinyl sulfonic acid, allyl sulfonic acid, and methallyl sulfonic acid, and salts thereof: maleic imide, phenyl maleimide, acrylamide, methacrylamide, styrene, α-methyl styrene, and the like. These monomers can be used alone or in combination of two or more.

  A preferable amount of the copolymerization component is less than 50% by mass in the polymer, more preferably 40% by mass or less, still more preferably 30% by mass or less, and particularly preferably 10% by mass or less. is there.

  A preferred molecular weight of the acrylonitrile-based polymer in the present invention is 1,000 to 10,000,000 as a weight average molecular weight, preferably 10,000 to 1,000,000, more preferably 50. , 000 to 500,000. If it is this range, micronization in the next process can be performed easily.

  The weight average molecular weight here refers to a weight average molecular weight measured by gel permeation chromatography (GPC) using dimethylformamide as a solvent and converted to standard polystyrene.

<Acrylonitrile polymer fine particles>
The average particle diameter of the acrylonitrile-based polymer fine particles (hereinafter sometimes referred to as resin fine particles) in the present invention is in the range of 1 to 100 μm, preferably in the range of 5 to 80 μm, more preferably 5 to 60 μm. More preferably, it is 5-50 micrometers, Most preferably, it is 5-20 micrometers.

  The average particle diameter here refers to a median diameter in a particle diameter distribution based on a volume average particle diameter measured by a laser diffraction particle diameter distribution meter based on the so-called Mie scattering / diffraction theory. Specifically, in the case of obtaining a particle size distribution curve of the particle size and the solid particle amount, it means a particle size (so-called 50% particle size) at which the integrated solid particle amount is 50% with respect to the total solid particle amount. It is.

  The particle size distribution index of the resin fine particles in the present invention is 3 or less, preferably 2 or less, more preferably 1.5 or less, particularly preferably 1.3 or less, and most preferably. Is 1.1 or less. The preferred lower limit is 1.

  Here, the particle size distribution index is defined as the ratio (= Dv / Dn) of the volume average particle size (Dv) to the number average particle size (Dn).

  The particle size distribution index is calculated from the ratio of the volume average particle size to the number average particle size according to the following formula (4). The number average particle diameter and the volume average particle diameter referred to here are calculated from the following equations (2) and (3) by observing 100 arbitrary particles in a scanning electron micrograph and measuring the diameter. When the particle is not a perfect circle, the major axis is measured.

  Here, Di: particle diameter of individual particles, n: number of measurements (100), Dn: number average particle diameter, Dv: volume average particle diameter, PDI: particle diameter distribution index.

  The resin fine particles used in the present invention are mainly composed of an acrylonitrile-based polymer, but depending on the purpose, the resin fine particles may have additive particles such as rubber particles, metal particles, and other inorganic particles. good. In the above, the main component is one containing more than 50% by mass of acrylonitrile-based polymer in the resin fine particles, preferably 60% by mass or more, and more preferably 70% by mass or more. Of course, resin fine particles made of an acrylonitrile-based polymer alone can also be preferably used.

  As the rubber particles that can be used for the resin fine particles, rubber having an affinity for the acrylonitrile copolymer is preferable. Specific examples include acrylonitrile-butadiene rubber (NBR) and styrene-butadiene rubber (SBR).

  Examples of the metal particles include iron, alumina powder, nickel powder, copper powder, silver powder, and solder powder.

  Examples of other inorganic particles include silica, alumina, zirconia, silicon carbide, barium titanate, aluminosilicate, kaolinite, calcium carbonate, barium sulfate, glass, graphite, amorphous carbon, activated carbon, and the like.

  The particle diameter of the additive particles is 1/3 or less, preferably 1/4 or less, more preferably 1/5 or less, more preferably 1 or less with respect to the resin fine particles. / 8 or less, and particularly preferably 1/10 or less.

  Moreover, a preferable lower limit is 50 nm.

  The average particle diameter here means the median diameter defined in the section of resin fine particles.

  Additive particles having an average particle diameter in this range are of an appropriate size to be taken into the resin fine particles and are easy to handle.

  The average particle diameter of the added particles can be measured with a particle size distribution meter before the addition. If measurement by this method is difficult, the measurement is performed with a scanning electron microscope. Furthermore, when the particle size of the additive particles is small and cannot be observed by this method, the magnification is increased to such an extent that it can be observed, or observation is performed using a transmission electron microscope, and the same method is used.

  When calculating the average particle size with a scanning electron microscope or a transmission electron microscope, each particle was measured at a magnification at which any 100 particles could be observed in the field of view of the microscope, and the arithmetic average was obtained. A thing is made into an average particle diameter.

  In addition, to confirm whether or not the additive particles have been taken into the particles, solidify the resin fine particles with an epoxy resin, create an ultrathin section for an electron microscope, and check with an optical microscope or a scanning electron microscope. be able to. If observation is difficult, it can be confirmed with a transmission electron microscope.

  The particle diameter of the additive particles in the resin fine particles is measured by observation with the ultrathin section for an electron microscope. At this time, the particle diameter on the photograph is not necessarily the cross section of the additive particle at the equator plane, and the maximum particle diameter on the photograph is taken as the particle diameter of the additive particle.

  When measuring the particle diameter of the additive particles in an ultrathin slice, 100 or more arbitrary particles of the additive particles are measured, and an arithmetic average is taken as the average particle diameter of the additive particles.

  The upper limit for adding the additive particles contained in the resin fine particles in the present invention is less than 50% by mass, preferably 40% by mass or less, and more preferably 30% by mass or less, based on the entire resin fine particles.

  The resin fine particles in the present invention preferably have a shape close to a true sphere. The sphericity of the resin fine particles in the present invention is 80 or more, preferably 85 or more, more preferably 90 or more, more preferably 95 or more. When the sphericity is less than 80, the dispersibility in a resin or the like deteriorates, which is not preferable.

  Here, the sphericity is the observation of particles with a scanning electron microscope (scanning electron microscope JSM-6301NF manufactured by JEOL Ltd.), measuring the short diameter and long diameter, and the average of 30 arbitrary particles. It is calculated according to the following mathematical formula (Formula 1).

<Method for producing acrylonitrile-based polymer fine particles>
As a method for obtaining acrylonitrile polymer fine particles, for example, a method for directly obtaining acrylonitrile polymer fine particles by polymerizing an acrylonitrile monomer by a known polymerization method such as emulsion polymerization, suspension polymerization, precipitation polymerization, A method of physically dispersing the polymer obtained by polymerizing in a solvent in which the acrylonitrile polymer does not dissolve (Japanese Patent Publication No. 49-31753), or the acrylonitrile polymer is heated and melted in the presence of water. Thereafter, a spraying method (Japanese Patent Publication No. 42-17544) has been proposed, and any method may be used. Among them, a polymer solution is phase-separated to form an emulsion, and a poor solvent is added. Thus, a method of obtaining fine particles (International Publication No. 2009/142231) is most preferable.

  For example, an acrylonitrile polymer (hereinafter referred to as polymer A) to be microparticulated, a polymer B dissolved in a poor solvent of polymer A and an organic solvent are dissolved and mixed, and a solution phase (hereinafter referred to as polymer A) containing polymer A as a main component. In a system in which phase separation into two phases of a polymer B as a main component (hereinafter also referred to as a polymer B solution phase), an emulsion is formed, and then a polymer is formed. The polymer A can be obtained by bringing it into contact with a poor solvent of A.

  The above method will be described more specifically.

  In the above, “a system in which polymer A, polymer B, and an organic solvent are dissolved and mixed and phase-separated into two phases of a solution phase mainly composed of polymer A and a solution phase mainly composed of polymer B” means a polymer When A, polymer B, and an organic solvent are mixed, the system is divided into two phases, a solution phase mainly containing polymer A and a solution phase mainly containing polymer B.

  By using such a phase-separating system, it is possible to mix and emulsify under the phase-separating conditions to form an emulsion.

  In the above, whether or not the polymer is dissolved is more than 1% by mass with respect to the organic solvent at the temperature at which this method is carried out, that is, the temperature at which the polymer A and the polymer B are dissolved and mixed to separate into two phases. Judged by whether or not to dissolve.

  This emulsion has a polymer A solution phase in the dispersed phase, a polymer B solution phase in the continuous phase, and a polymer A solution in contact with the polymer A poor solvent by contacting the emulsion with the polymer A poor solvent. A precipitates, and resin fine particles composed of the polymer A can be obtained.

  In addition, when adding the additive particles into the resin fine particles, it can be carried out by adding the target additive particles to the solution phase of the polymer A.

  In this method, there is no particular limitation on the combination as long as the acrylonitrile-based polymer fine particles of this method are obtained using polymer A, polymer B, an organic solvent for dissolving them, and a poor solvent for polymer A.

  In the present method, the polymer A is preferably insoluble in the poor solvent, since the present method is intended to precipitate fine particles when contacting with the poor solvent, and a polymer that does not dissolve in the poor solvent described later is used. A water-insoluble polymer is particularly preferable.

  Here, the water-insoluble polymer is a polymer having a solubility in water of 1% by mass or less, preferably 0.5% by mass or less, and more preferably 0.1% by mass or less.

  Examples of the polymer B include thermoplastic resins and thermosetting resins, but those that are soluble in an organic solvent that dissolves the polymer A used in the present method and a poor solvent for the polymer A are preferable. And what dissolve | melts in an alcohol solvent or water is more preferable at the point which is excellent in industrial handleability, and also what melt | dissolves in an organic solvent and melt | dissolves in methanol, ethanol, or water is especially preferable.

  Specific examples of the polymer B include poly (vinyl alcohol) (which may be fully saponified or partially saponified poly (vinyl alcohol)), poly (vinyl alcohol-ethylene) copolymer ( Fully saponified or partially saponified poly (vinyl alcohol-ethylene) copolymer), polyvinylpyrrolidone, poly (ethylene glycol), sucrose fatty acid ester, poly (oxyethylene fatty acid ester), poly (Oxyethylene laurin fatty acid ester), poly (oxyethylene glycol monofatty acid ester), poly (oxyethylene alkylphenyl ether), poly (oxyalkyl ether), polyacrylic acid, sodium polyacrylate, polymethacrylic acid, polymethacrylic acid Sodium, polystyrenesulfonic acid, poly Sodium styrenesulfonate, polyvinylpyrrolidinium chloride, poly (styrene-maleic acid) copolymer, aminopoly (acrylamide), poly (paravinylphenol), polyallylamine, polyvinyl ether, polyvinyl formal, poly (acrylamide), poly ( Methacrylamide), poly (oxyethyleneamine), poly (vinyl pyrrolidone), poly (vinyl pyridine), polyaminosulfone, polyethyleneimine, and other synthetic resins, disaccharides such as maltose, cellobiose, lactose, sucrose, cellulose, chitosan, hydroxy Ethyl cellulose, hydroxypropyl cellulose, methyl cellulose, ethyl cellulose, ethyl hydroxy cellulose, carboxymethyl ethyl cellulose, carboxymethyl cell Cellulose, cellulose derivatives such as sodium carboxymethylcellulose, cellulose ester, amylose and derivatives thereof, starch and derivatives thereof, polysaccharides or derivatives thereof such as dextrin, cyclodextrin, sodium alginate and derivatives thereof, gelatin, casein, collagen, albumin, Examples include fibroin, keratin, fibrin, carrageenan, chondroitin sulfate, gum arabic, agar, protein, etc., preferably poly (vinyl alcohol) (fully saponified or partially saponified poly (vinyl alcohol)) Good), poly (vinyl alcohol-ethylene) copolymer (may be fully or partially saponified poly (vinyl alcohol-ethylene) copolymer), polyethylene glycol, sucrose fatty acid Ester, poly (oxyethylene alkylphenyl ether), poly (oxyalkyl ether), poly (acrylic acid), poly (methacrylic acid), carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, methylcellulose, ethylcellulose, ethylhydroxycellulose, carboxymethyl Cellulose derivatives such as ethyl cellulose, carboxymethyl cellulose, sodium carboxymethyl cellulose, cellulose ester, and polyvinyl pyrrolidone, and more preferably poly (vinyl alcohol) (fully saponified or partially saponified poly (vinyl alcohol)). ), Poly (vinyl alcohol-ethylene) copolymer (fully saponified or partially saponified poly (vinyl alcohol-ethylene) Polymer), polyethylene glycol, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, methylcellulose, ethylcellulose, ethylhydroxycellulose, carboxymethylethylcellulose, carboxymethylcellulose, carboxymethylcellulose sodium, cellulose ester, and the like, and polyvinylpyrrolidone, particularly preferred Is poly (vinyl alcohol) (may be fully saponified or partially saponified poly (vinyl alcohol)), poly (ethylene glycol), carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, methylcellulose, ethylcellulose, ethyl Cellulose derivatives such as hydroxycellulose, poly Is Nirupiroridon.

  The molecular weight of the polymer B is preferably 1,000 to 100,000,000, more preferably 1,000 to 10,000,000, and still more preferably 5,000 to 1,000,000 in terms of weight average molecular weight. 000, particularly preferably in the range of 10,000 to 500,000, and most preferably in the range of 10,000 to 100,000.

  The weight average molecular weight here refers to a weight average molecular weight measured by gel permeation chromatography (GPC) using water as a solvent and converted into polyethylene glycol.

  Use dimethylformamide when it cannot be measured with water, use tetrahydrofuran when it cannot be measured with water, and use hexafluoroisopropanol when it cannot be measured with water.

  The organic solvent that dissolves the polymer A and the polymer B is an organic solvent that can dissolve the polymer A and the polymer B to be used, and is selected according to the type of each polymer.

  Specific examples include aliphatic hydrocarbon solvents such as pentane, hexane, heptane, octane, nonane, n-decane, n-dodecane, n-tridecane, tetradecane, cyclohexane, cyclopentane, benzene, toluene, xylene, 2- Aromatic hydrocarbon solvents such as methylnaphthalene, ester solvents such as ethyl acetate, methyl acetate, butyl acetate, butyl propionate, butyl butyrate, chloroform, bromoform, methylene chloride, carbon tetrachloride, 1,2-dichloroethane, 1 , 1,1-trichloroethane, chlorobenzene, 2,6-dichlorotoluene, halogenated hydrocarbon solvents such as hexafluoroisopropanol, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl butyl ketone, methanol, ethanol, 1 - Alcohol solvents such as propanol and 2-propanol, N-methyl-2-pyrrolidone (NMP), dimethyl sulfoxide (DMSO), N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMA), propylene carbonate , Aprotic polar solvents such as trimethyl phosphoric acid, 1,3-dimethyl-2-imidazolidinone, sulfolane, carboxylic acid solvents such as formic acid, acetic acid, propionic acid, butyric acid, lactic acid, anisole, diethyl ether, tetrahydrofuran, diisopropyl Ether solvents such as ether, dioxane, diglyme, dimethoxyethane, 1-butyl-3-methylimidazolium acetate, 1-butyl-3-methylimidazolium hydrogen sulfate, 1-ethyl-3-imidazolium acetate, 1 Ethyl-3-methyl-ionic liquids or mixtures thereof, such as imidazolium thiocyanates, and the like, the polymer component A to be used is appropriately selected depending on the type of polymer B component. Preferably, an aromatic hydrocarbon solvent, an aliphatic hydrocarbon solvent, a halogenated hydrocarbon solvent, an alcohol solvent, an ether solvent, an aprotic polar solvent, a carboxylic acid solvent, Preferable ones are alcohol solvents, aprotic polar solvents and carboxylic acid solvents which are water-soluble solvents, and extremely preferred are aprotic polar solvents and carboxylic acid solvents, which are easily available and have a wide range. N is most preferable because it can be dissolved in a wide range of polymers, and can be uniformly mixed with a solvent that can be preferably used as a poor solvent to be described later, such as water and alcohol-based solvents. -Methyl-2-pyrrolidone, dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, propylene carbonate DOO, formic acid, acetic acid.

  These organic solvents may be used in a plurality of types, or may be used in combination. However, particles having a relatively small particle size and a small particle size distribution can be obtained, and when used solvents are recycled. From the standpoint of reducing the process load in manufacturing, avoiding the troublesome separation step, it is preferable to use a single organic solvent, and it should be a single organic solvent that dissolves both polymer A and polymer B. Is preferred.

  The poor solvent for polymer A in this method refers to a solvent that does not dissolve polymer A. When the solvent is not dissolved, the solubility of the polymer A in the poor solvent is 1% by mass or less, more preferably 0.5% by mass or less, and further preferably 0.1% by mass or less.

  In this method, a poor solvent for polymer A is used, and the poor solvent is preferably a poor solvent for polymer A and a solvent that dissolves polymer B. Thereby, the polymer fine particle comprised with the polymer A can be precipitated efficiently. Moreover, it is preferable that the solvent for dissolving the polymer A and the polymer B and the poor solvent for the polymer A are solvents that are uniformly mixed.

  The poor solvent in this method varies depending on the type of polymer A to be used, desirably both types of polymers A and B to be used. Specifically, for example, pentane, hexane, heptane, octane, nonane, n -Aliphatic hydrocarbon solvents such as decane, n-dodecane, n-tridecane, tetradecane, cyclohexane, cyclopentane, etc., aromatic hydrocarbon solvents such as benzene, toluene, xylene, 2-methylnaphthalene, ethyl acetate, methyl acetate Ester solvents such as butyl acetate, butyl propionate and butyl butyrate, chloroform, bromoform, methylene chloride, carbon tetrachloride, 1,2-dichloroethane, 1,1,1-trichloroethane, chlorobenzene, 2,6-dichlorotoluene, Halogenated hydrocarbons such as hexafluoroisopropanol Solvents, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl butyl ketone, alcohol solvents such as methanol, ethanol, 1-propanol, 2-propanol, dimethyl sulfoxide, N, N-dimethylformamide, N, N -Aprotic polar solvents such as dimethylacetamide, trimethylphosphoric acid, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, sulfolane, carboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, lactic acid Examples include acid solvents, ether solvents such as anisole, diethyl ether, tetrahydrofuran, diisopropyl ether, dioxane, diglyme and dimethoxyethane, and a solvent selected from at least one of water.

  From the viewpoint of efficiently atomizing the polymer A, an aromatic hydrocarbon solvent, an aliphatic hydrocarbon solvent, an alcohol solvent, an ether solvent, and water are preferable, and an alcohol solvent, water is most preferable. Particularly preferred is water.

  In this method, polymer A can be efficiently precipitated and resin fine particles can be obtained by appropriately selecting and combining polymer A, polymer B, an organic solvent for dissolving them, and a poor solvent for polymer A.

  At this time, the liquid obtained by mixing and dissolving the polymers A and B and the organic solvent for dissolving them is phase-separated into two phases, a solution phase mainly composed of the polymer A and a solution phase mainly composed of the polymer B. is required.

  At this time, the solution-phase organic solvent containing polymer A as the main component and the organic solvent containing polymer B as the main component may be the same or different, but are preferably substantially the same solvent.

  Conditions for generating a state of two-phase separation vary depending on the types of polymers A and B, the molecular weights of polymers A and B, the types of organic solvents, the concentrations of polymers A and B, the temperature and pressure at which this method is performed. come.

  In order to obtain conditions that are likely to result in a phase-separated state, it is preferable that the difference between the solubility parameters of the polymer A and the polymer B (hereinafter also referred to as SP values) is separated.

At this time, the difference in SP value is 1 (J / cm ³ ) ^1/2 or more, more preferably 2 (J / cm ³ ) ^1/2 or more, and further preferably 3 (J / cm ³ ) ^1/2 or more. Particularly preferably, it is 5 (J / cm ³ ) ^1/2 or more, and very preferably 8 (J / cm ³ ) ^1/2 or more. When the SP value is within this range, phase separation is easily performed.

There is no particular limitation as long as both polymer A and polymer B can be dissolved in an organic solvent, but the upper limit of the difference in SP value is preferably 20 (J / cm ³ ) ^1/2 or less, more preferably 15 (J / Cm ³ ) ^1/2 or less, more preferably 10 (J / cm ³ ) ^1/2 or less.

  Here, the SP value is calculated based on the Fedor's estimation method, and is calculated based on the cohesive energy density and the molar molecular volume (hereinafter also referred to as a calculation method). ("SP Value Basics / Applications and Calculation Methods" by Hideki Yamamoto, Information Organization Co., Ltd., published on March 31, 2005).

  When the calculation cannot be performed by this estimation method, the SP value is calculated by an experimental method by determining whether or not the solubility parameter is dissolved in a known solvent (hereinafter also referred to as an experimental method). ("Polymer Handbook Fourth Edition" by J. Brand, published in Wiley 1998).

  In order to select the conditions for the phase separation state, a three-component phase diagram can be prepared by a simple preliminary experiment by observing a state in which the ratio of the three components of the polymer A, the polymer B, and the organic solvent in which they are dissolved is changed. Can be distinguished.

  The phase diagram is prepared by mixing and dissolving the polymers A and B and the solvent at an arbitrary ratio and determining whether or not an interface is formed when allowed to stand at least 3 points, preferably 5 points or more. Preferably, the measurement is performed at 10 points or more, and by separating the region that separates into two phases and the region that becomes one phase, the conditions for achieving the phase separation state can be determined.

  At this time, in order to determine whether or not it is in a phase-separated state, the polymers A and B are adjusted to any ratio of the polymers A and B and the solvent at the temperature and pressure at which the present invention is to be carried out. Then, the polymers A and B are completely dissolved, and after the dissolution, the mixture is sufficiently stirred and left for 3 days to confirm whether or not the phase separation is performed macroscopically.

  However, in the case of a sufficiently stable emulsion, macroscopic phase separation may not occur even after standing for 3 days. In that case, an optical microscope, a phase contrast microscope, or the like is used to determine the phase separation based on whether or not the phase separation is microscopically.

  The phase separation is formed by separating into a polymer A solution phase mainly composed of polymer A and a polymer B solution phase mainly composed of polymer B in an organic solvent. At this time, the polymer A solution phase is a phase in which the polymer A is mainly distributed, and the polymer B solution phase is a phase in which the polymer B is mainly distributed. At this time, the polymer A solution phase and the polymer B solution phase seem to have a volume ratio corresponding to the types and amounts of the polymers A and B used.

  The concentration of the polymers A and B with respect to the organic solvent is premised on being within a possible range that can be dissolved in the organic solvent. Is more than 1% by mass to 50% by mass, more preferably more than 1% by mass to 30% by mass, and still more preferably 2% by mass to 20% by mass.

  In this method, since the interfacial tension between the two phases of the polymer A solution phase and the polymer B solution phase is an organic solvent, the interfacial tension is small, and the resulting emulsion can be stably maintained due to its properties. The particle size distribution seems to be smaller. In particular, when the organic solvents of the polymer A phase and the polymer B phase are the same, the effect is remarkable.

Since the interfacial tension between the two phases in this method is too small, it cannot be measured directly by the hanging drop method in which a different kind of solution is added to a commonly used solution. The interfacial tension can be estimated by estimating from the surface tension. When the surface tension of each phase with air is r ₁ and r ₂ , the interfacial tension r ₁₂ can be estimated by an absolute value of r ₁₂ = r ₁ −r ₂ . At this time, a preferable range of r ₁₂ is more than 0 to 10 mN / m, more preferably more than 0 to 5 mN / m, still more preferably more than 0 to 3 mN / m, and particularly preferably 0. Super-2 mN / m.

  The viscosity between the two phases in this method affects the average particle size and particle size distribution, and the smaller the viscosity ratio, the smaller the particle size distribution. In the case where the viscosity ratio is defined as the polymer A solution phase / polymer solution phase B under the temperature conditions for carrying out the present invention, a preferable range is 0.1 or more and 10 or less, and a more preferable range is 0.1. 2 or more and 5 or less, more preferably 0.3 or more and 3 or less, particularly preferably 0.5 or more and 1.5 or less, and remarkably preferable range is 0.8 or more and 1.2 or less. is there.

  Using the phase-separating system thus obtained, resin fine particles are produced. The atomization is performed in a normal reaction tank. The temperature suitable for carrying out the present invention is in the range of −50 ° C. to 200 ° C., preferably −20 ° C. to 150 ° C., more preferably 0 ° C. to 120 ° C. from the viewpoint of industrial feasibility. More preferably, it is 10-100 degreeC, Most preferably, it is 20-80 degreeC, Most preferably, it is the range of 20-50 degreeC. From the viewpoint of industrial feasibility, the pressure suitable for carrying out the present invention is in the range of 100 atm from the reduced pressure state, preferably in the range of 1 to 5 atm, and more preferably in the range of 1 to 2 atm. Atmospheric pressure, particularly preferably atmospheric pressure.

  An emulsion is formed by mixing the phase-separated system state under such conditions.

  That is, an emulsion is formed by applying a shearing force to the phase separation solution obtained above.

  In forming the emulsion, the emulsion is formed so that the polymer A solution phase becomes particulate droplets. However, when the volume of the polymer B solution phase is larger than the volume of the polymer A solution phase after phase separation is generally performed. The emulsion in such a form tends to be easily formed, and the volume ratio of the polymer A solution phase is particularly preferably 0.4 or less with respect to the total volume 1 of both phases, 0.4 to 0.1 It is preferable to be between. When preparing the phase diagram, it is possible to set an appropriate range by simultaneously measuring the volume ratio in the concentration of each component.

  The resin fine particles obtained by this production method become fine particles having a small particle size distribution because a very uniform emulsion can be obtained at the stage of emulsion formation. This tendency is remarkable when a single solvent that dissolves both the polymers A and B is used. For this reason, in order to obtain a sufficient shearing force to form an emulsion, it is sufficient to use stirring by a conventionally known method, such as a liquid phase stirring method using a stirring blade, a stirring method using a continuous biaxial mixer, or a homogenizer. They can be mixed by a generally known method such as a mixing method or ultrasonic irradiation.

  In particular, in the case of stirring with a stirring blade, although depending on the shape of the stirring blade, the stirring speed is preferably 50 rpm to 1200 rpm, more preferably 100 rpm to 1000 rpm, still more preferably 200 rpm to 800 rpm, and particularly preferably 300 rpm to 600 rpm.

  Specific examples of the stirring blade include a propeller type, a paddle type, a flat paddle type, a turbine type, a double cone type, a single cone type, a single ribbon type, a double ribbon type, a screw type, and a helical ribbon type. However, it is not particularly limited as long as a sufficient shearing force can be applied to the system. Moreover, in order to perform efficient stirring, you may install a baffle plate etc. in a tank.

  In order to generate an emulsion, not only a stirrer but also a widely known device such as an emulsifier and a disperser may be used. Specifically, a batch emulsifier such as a homogenizer (manufactured by IKA), polytron (manufactured by Kinematica), TK auto homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), Ebara Milder (manufactured by Ebara Seisakusho) , TK fill mix, TK pipeline homomixer (manufactured by Koki Kogyo Co., Ltd.), colloid mill (manufactured by Shinko Pantech Co., Ltd.), slasher, trigonal wet pulverizer (manufactured by Mitsui Miike Chemical Co., Ltd.), ultrasonic homogenizer, static For example, a mixer.

  The emulsion thus obtained is subsequently subjected to a step of precipitating target fine particles.

  In order to obtain the target resin fine particles, the target resin fine particles are deposited with a diameter corresponding to the emulsion diameter by bringing a poor solvent for the polymer A into contact with the emulsion produced in the above-described step.

  The contact method of the poor solvent and the emulsion may be a method of putting the emulsion in the poor solvent or a method of putting the poor solvent in the emulsion, but a method of putting the poor solvent in the emulsion is preferable.

  In this case, the method for introducing the poor solvent is not particularly limited as long as the acrylonitrile-based polymer fine particles produced in the present invention are obtained, and any of the continuous dropping method, the divided addition method, and the batch addition method may be used. In order to prevent the emulsion from agglomerating, fusing and coalescing at the time of addition, the particle size distribution becoming large, and the formation of a mass exceeding 1000 μm, it is preferable to use a continuous dropping method or a divided dropping method. In order to carry out efficiently efficiently, the continuous dropping method is most preferable.

  The time for adding the poor solvent is from 10 minutes to 50 hours, more preferably from 30 minutes to 10 hours, and even more preferably from 1 hour to 5 hours.

  If the time is shorter than this range, the particle size distribution may increase or a lump may be generated due to the aggregation, fusion and coalescence of the emulsion. Moreover, when it implements in the time longer than this, when industrial implementation is considered, it is unrealistic.

  By carrying out within this time range, aggregation between particles can be suppressed when converting from emulsion to resin fine particles, and resin fine particles having a small particle size distribution can be obtained.

  The amount of the poor solvent to be added depends on the state of the emulsion, but is preferably 0.1 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, and still more preferably, with respect to 1 part by weight of the total emulsion. Is 0.2 to 3 parts by weight, particularly preferably 0.2 to 1 part by weight, and most preferably 0.2 to 0.5 parts by weight.

  The contact time between the poor solvent and the emulsion may be a time sufficient for the fine particles to precipitate, but in order to cause sufficient precipitation and to obtain efficient productivity, 5 minutes to 50 minutes after the addition of the poor solvent is completed. Time, more preferably 5 minutes or more and 10 hours or less, still more preferably 10 minutes or more and 5 hours or less, particularly preferably 20 minutes or more and 4 hours or less, and particularly preferably 30 minutes or more and 3 hours or less. Within hours.

  The acrylonitrile-based polymer fine particle dispersion prepared in this way is filtered, decanted, vacuum filtered, pressure filtered, centrifuged, centrifugal filtered, spray dried, acid precipitation, salting out, freeze coagulation, etc. Fine particle powder can be recovered by solid-liquid separation by a generally known method.

  The resin fine particles separated by solid-liquid separation are purified by washing with a solvent or the like, if necessary, to remove attached or contained impurities and the like. In this case, the preferred solvent is the above poor solvent, and more preferably one or more mixed solvents selected from water, methanol, and ethanol.

  The obtained acrylonitrile-based polymer fine particles can be dried to remove the residual solvent. In this case, examples of the drying method include air drying, heat drying, reduced pressure drying, and freeze drying. The temperature for heating is preferably lower than the glass transition temperature, and specifically 50 to 150 ° C is preferable.

  In the method of the present invention, it is advantageous that recycling can be performed by utilizing the organic solvent and polymer B separated in the solid-liquid separation step performed when the resin fine particles are obtained.

The solvent obtained by solid-liquid separation is a mixture of polymer B, an organic solvent and a poor solvent. By removing the poor solvent from this solvent, it can be reused as a solvent for forming an emulsion. The method for removing the poor solvent is usually performed by a known method, and specific examples include simple distillation, vacuum distillation, precision distillation, thin film distillation, extraction, membrane separation, and the like. This is a method by distillation or precision distillation.
When performing distillation operations such as simple distillation and vacuum distillation, it is preferable to carry out in a state free from oxygen as much as possible because heat is applied to the system and the thermal decomposition of the polymer B and the organic solvent may be accelerated. Preferably, it is performed under an inert atmosphere. Specifically, it is carried out under nitrogen, helium, argon, carbon dioxide conditions.

<Method for creating epoxy resin composition>
The desired epoxy resin composition can be obtained by mixing the resin fine particles obtained as described above in an epoxy resin.

  The preferable amount of the acrylonitrile-based polymer fine particles to be added to the epoxy resin composition in the present invention is 1 to 50% by mass, preferably 1 to 40% by mass, more preferably based on the total amount of the epoxy resin composition. Is 2-30 mass%, More preferably, it is 5-20 mass%.

  The epoxy resin composition of the present invention can be prepared by adding acrylonitrile-based polymer fine particles to an epoxy resin and kneading using a generally known kneader.

  Examples of the kneading apparatus include a three-roll kneader, a self-revolving mixer, a planetary mixer, and the like.

<Hardened epoxy resin>
A cured epoxy resin can be obtained by adding a curing agent to the epoxy resin composition obtained above to cause a curing reaction.

  As the epoxy resin curing agent, any compound having an active group capable of reacting with an epoxy resin can be used.

  Preferably, a compound having an amino group, an acid anhydride group or an azide is suitable. Examples include dicyandiamide, alicyclic amines, aliphatic amines, aromatic amines, aminobenzoic acid esters, various acid anhydrides, phenol novolac resins, cresol novolac resins, imidazole derivatives, boron trifluoride complexes and boron trichloride. Examples include Lewis acid complexes such as complexes.

  In particular, an aromatic amine curing agent is preferably used in terms of providing an epoxy resin cured product having excellent mechanical properties. Of these, aromatic polyamines having two or more amino groups are preferred from the viewpoint of heat resistance.

  Specific examples of aromatic polyamines include metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, metaxylylenediamine, diphenyl-para-dianiline, various derivatives such as these alkyl substituents, and different amino positions. Isomers. These curing agents can be used alone or in combination of two or more. Of these, diaminodiphenylmethane and diaminodiphenylsulfone are preferable from the viewpoint of imparting heat resistance to the composition.

  Examples of diaminodiphenyl sulfone include isomers such as 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, and 4,4'-diaminodiphenyl sulfone. From the viewpoint of heat resistance, 4,4'-diaminodiphenyl sulfone is particularly preferable.

  The optimum value of the amount added varies depending on the type of epoxy resin and curing agent.

  For example, in an aromatic amine curing agent, the stoichiometric equivalent ratio is preferably between 0.5 and 1.4 based on the total epoxy groups contained in the epoxy resin composition of the present invention, and more Preferably it is 0.6-1.4. When the equivalent ratio is less than 0.5, the curing reaction does not occur sufficiently, and curing failure may occur or the curing reaction may take a long time. When the equivalent ratio is larger than 1.4, the curing agent that is not consumed at the time of curing becomes a defect, which may deteriorate the mechanical properties.

  The curing agent can be used in either monomer or oligomer form, and can be in either powder or liquid form when mixed. These curing agents may be used alone or in combination. Moreover, you may use together a hardening accelerator.

  For example, combinations of aromatic polyamines and Lewis acid complexes, combinations of dicyandiamide and imidazole derivatives, combinations of dicyandiamide and urea compounds, and combinations such as aromatic polyamines, dicyandiamide and urea compounds are cured at relatively low temperatures. It is preferably used because high heat resistance and water resistance can be obtained.

  These curing agents are mixed with the epoxy resin composition in which the polyacrylonitrile-based fine particles described above are mixed, and then cured to obtain an epoxy resin cured product.

  The addition of these curing agents may be mixed with the epoxy resin simultaneously with the polyacrylonitrile-based fine particles described above.

  In order to advance the curing reaction for obtaining a cured epoxy resin, a temperature may be applied as necessary. The temperature at that time is room temperature to 250 ° C., preferably 50 to 200 ° C., more preferably 70. ~ 180 ° C.

  Moreover, you may apply the temperature raising program as needed.

The pressure at the time of curing, 1.0~100kg / cm ^2, preferably 1.0~50kg / cm ^2, more preferably 1.0~20kg / cm ^2, more preferably, 1.0～5Kg / cm ² .

  You may add an additive to the epoxy resin composition of this invention as needed. Examples of additives include carbon black, calcium carbonate, titanium oxide, silica, aluminum hydroxide, glass fiber, hindered amine and hindered phenol degradation inhibitors.

  These are preferably added at the stage before curing, and may be added in any form of powder, liquid, or slurry during mixing.

<Application>
The epoxy resin obtained in the present invention has the property that the toughness of the cured product is improved despite no volume expansion, so that it can be used as a primer, paint for automobile interior / exterior coating, home appliance / building material, Suitable for adhesives, inks, electronic information materials (circuit mounted substrates for mobile phones, personal computers, etc.), LED / semiconductor encapsulants, various encapsulants, sports, general industrial and aerospace applications .

  Hereinafter, the present invention will be described more specifically with reference to examples. The present invention is not limited by these examples.

<Creation of resin fine particles>
Production Example 1 Production Method of Acrylonitrile-Based Polymer Fine Particles 99 parts by mass of acrylonitrile and 1 part by mass of itaconic acid were dissolved in 400 parts by mass of dimethyl sulfoxide in a reaction vessel equipped with a reflux tube and a stirring blade, and then 0.5 mass of benzoyl peroxide. Part was added, and the temperature was raised to 70 ° C. and polymerization was carried out for 6 hours to obtain an acrylonitrile-based polymer solution. The weight average molecular weight of the solution was 530,000. 172 parts by mass of polyvinyl alcohol (“GOHSENOL (registered trademark)” GL-05, weight average molecular weight 10,600, SP value 32.8 (J / cm ³ ) ^1/2 ) manufactured by Nippon Synthetic Chemical Industry Co., Ltd., 2776 parts by mass of dimethyl sulfoxide was added, heated at 80 ° C., and stirred until all the polymers were dissolved. After returning the temperature of the system to room temperature, while stirring at 450 rpm, 1500 parts by mass of ion-exchanged water as a poor solvent is dropped at a speed of 25 parts by mass via a liquid feed pump, and particles are collected. Precipitated. The obtained fine particles were isolated, washed with water, and dried. The number average particle size of the obtained acrylonitrile-based polymer fine particles was 8.0 μm, the particle size distribution index was 1.30, and the sphericity was 91. The SP value of this polymer was 29.5 (J / cm ³ ) ^1/2 according to the calculation method.

Production Example 2 Production Method of Acrylonitrile Polymer Fine Particles After dissolving 100 parts by mass of acrylonitrile in 400 parts by mass of dimethyl sulfoxide in a reaction vessel equipped with a reflux tube and a stirring blade, 0.5 part by mass of benzoyl peroxide was added, and 70 ° C. The polymer was heated to 6 hours and polymerized by holding for 6 hours to obtain an acrylonitrile-based polymer solution. The weight average molecular weight of the solution was 530,000. 172 parts by mass of polyvinyl alcohol (“GOHSENOL (registered trademark)” GL-05, weight average molecular weight 10,600, SP value 32.8 (J / cm ³ ) ^1/2 ) manufactured by Nippon Synthetic Chemical Industry Co., Ltd., 2776 parts by mass of dimethyl sulfoxide was added, heated at 80 ° C., and stirred until all the polymers were dissolved. After returning the temperature of the system to room temperature, while stirring at 450 rpm, 1500 parts by mass of ion-exchanged water as a poor solvent is dropped at a speed of 25 parts by mass via a liquid feed pump, and particles are collected. Precipitated. The obtained fine particles were isolated, washed with water, and dried. The number average particle size of the obtained acrylonitrile-based polymer fine particles was 9.2 μm, the particle size distribution index was 1.25, and the sphericity was 90. The SP value of this polymer was 29.5 (J / cm ³ ) ^1/2 according to the calculation method.

Production Examples 3 and 4 Preparation of Epoxy Resin Composition 190 parts by mass of bisphenol A type epoxy resin A (“jER” (registered trademark) 828: manufactured by Japan Epoxy Resin Co., Ltd.) and bisphenol A type epoxy resin B (“jER”) (Registered trademark) 1001: Japan Epoxy Resin Co., Ltd.) 475 parts by mass, 87.5 parts of acrylonitrile polymer fine particles prepared in Production Examples 1 and 2 were heated to 90 ° C. and mixed until uniform. An epoxy resin composition was obtained.

  7 parts of 4,4′-diaminodiphenylsulfone is added to 43 parts by mass of the obtained epoxy resin composition, and mixed at 2000 rpm, 10 kPa for 3 minutes using a self-revolving mixer “Awatori Nertaro” (manufactured by Sinky Corporation). Stirring was performed to obtain an epoxy resin composition.

Production Example 5 Preparation of Epoxy Resin Composition without Addition of Fine Particles 190 parts by mass of bisphenol A type epoxy resin A (“jER” (registered trademark) 828: manufactured by Japan Epoxy Resin Co., Ltd.) and bisphenol A type epoxy resin B (“ 475 parts by mass of jER "(registered trademark) 1001: Japan Epoxy Resin Co., Ltd.) was heated to 90 ° C and mixed until uniform. 7 parts of 4,4′-diaminodiphenylsulfone is added to 38 parts by mass of the obtained epoxy resin composition, and mixed at 2000 rpm, 10 kPa for 3 minutes with a self-revolving mixer “Awatori Rentaro” (Sinky Corporation). Stirring was performed to obtain an uncured epoxy resin composition to which resin fine particles were not added.

Examples 1-2 and Comparative Example 1
Evaluation was carried out as follows using the uncured epoxy resin composition obtained in Production Examples 3 to 5. The results are shown in Table 1.

<Evaluation method>
(1) Toughness test of epoxy resin After defoaming the uncured epoxy resin composition obtained in Production Examples 3 to 5 in a vacuum, the thickness is made 6 mm with a 6 mm thick “Teflon” (registered trademark) spacer. In the mold set to 1, the temperature was increased from room temperature to 180 ° C. at a temperature rising rate of 1 ° C./min, and then cured by heating for 2 hours to obtain a cured epoxy resin product having a thickness of 6 mm.

  The cured epoxy resin was cut at 12.7 × 150 mm to obtain a test piece. Using an Instron universal testing machine (Instron), a test piece was processed according to ASTM D5045 and an experiment was conducted. The initial cracking was introduced into the test piece by applying a razor blade cooled to the liquid nitrogen temperature to the test piece and impacting the razor with a hammer. The fracture toughness of the cured resin here refers to the critical stress strength of deformation mode 1 (opening type).

(2) Bending test of cured epoxy resin The uncured epoxy resin composition obtained in Production Examples 3 to 5 was degassed in vacuum, and then 2 mm thick with a 2 mm thick “Teflon” (registered trademark) spacer. In the mold set so as to be, the temperature was increased from room temperature to 180 ° C. at a temperature rising rate of 1 ° C./min, followed by curing for 2 hours to obtain a cured resin product having a thickness of 2 mm.

  This cured resin was cut to a width of 10 ± 0.1 mm and a length of 60 ± 1 mm to obtain a test piece. Using an Instron universal testing machine (Instron), three-point bending with a span of 32 mm was measured in accordance with JIS K7171 (1994), and the bending elastic modulus and bending deflection were determined. The measurement temperature was room temperature (23 ° C.). The number of measurements was n = 5, and the average value was obtained.

(3) Thermal expansion coefficient Using the cured epoxy resin obtained in (1), a 10 mm × 6 mm × 4 mm test piece was processed, and the linear expansion coefficient was measured.
<Use model> Seiko Instruments Inc. TMA100
<Measurement temperature conditions> Measurement start temperature: 30 ° C. (no holding time)
Temperature increase rate: 5 ° C / min
Measurement end temperature: 140 ° C. (no holding time).

(4) Thermal deformation start temperature In the said thermal expansion coefficient measurement, the temperature which started softening was made into thermal deformation start temperature.

(5) Differential scanning calorimetry Differential epoxy scanning calorimetry of the cured epoxy resin obtained in (1) was performed under the following conditions, and the glass transition temperature was measured.
<Model used> Seiko Instruments differential scanning calorimeter DSC-7 type <Measurement atmosphere> Under nitrogen <Measurement temperature condition> Measurement start temperature: 30 ° C. (no holding time)
Temperature increase rate: 20 ° C / min
Measurement end temperature: 200 ° C. (holding time 2 minutes)
Temperature decrease rate: 40 ° C./min Temperature decrease.

(6) Particle dispersibility (morphology)
An ultrathin section of the test sample obtained in (1) was prepared, cross-sectional observation was performed, and the dispersibility of the particles was evaluated. For reference, the observation results in Example 1 are shown in FIG.
<Use model> Phase contrast microscope <Measurement magnification> Good 250 times: The polyacrylonitrile-based fine particles were uniformly dispersed and good.

Claims (6)

An epoxy resin composition comprising acrylonitrile-based polymer fine particles in an epoxy resin. 2. The epoxy resin composition according to claim 1, wherein the acrylonitrile polymer is a polymer containing acrylonitrile monomer units in an amount of 50% by mass or more. The epoxy resin composition according to claim 1 or 2, wherein the resin fine particles have an average particle diameter of 1 to 100 µm. The epoxy resin composition according to claim 1, wherein the resin particle has a particle size distribution index of 1 to 3 and a sphericity of 80 or more. The epoxy resin composition according to any one of claims 1 to 4, comprising 1 to 50% by mass of resin fine particles. An epoxy resin cured product obtained by curing the epoxy resin composition according to claim 1 and a curing agent.

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