TW201813999A - Composite particles and manufacturing method thereof wherein the composite particles are easily dissolved in an epoxy resin - Google Patents

Abstract

The present invention provides composite particles and a manufacturing method thereof for improving solubility of polyvinyl formal resin in epoxy resin. In the present invention, a polyvinyl formal resin having pores is kneaded with a liquid epoxy resin without melting, and the pores of the polyvinyl formal resin are filled with a liquid epoxy resin, so as to provide composite particles that are easily dissolved in an epoxy resin and a manufacturing method thereof. The liquid epoxy resin may be obtained by using one liquid epoxy resin, mixing at least two liquid epoxy resins, or dissolving at least one solid epoxy resin in at least one liquid epoxy resin.

Description

Composite particle and manufacturing method thereof

The present invention relates to a composite particle having improved solubility in an epoxy resin and a method for producing the same. The composite particles are particles in which a liquid epoxy resin is kneaded in polyvinyl formal particles having pores, and the pores are filled with a liquid epoxy resin.

The composite particles of the present invention can be used as a toughening agent for epoxy resins. In addition, epoxy resins have excellent adhesion, strength, heat resistance, mechanical properties, and electrical properties, so they are used as base resins in adhesives, coatings, civil construction materials, electrical and electronic insulation materials, sealing materials, and composite materials. Widely used in other fields.

Especially when epoxy resin is used as the matrix resin of the composite material, an intermediate material called a prepreg is often used for molding, and characteristics such as tack and drapability are required. Furthermore, for the purpose of improving the adhesion between the carbon fiber and the matrix resin, a thermoplastic resin is often blended. Polyvinyl acetals are often used as thermoplastic resins, with polyvinyl formal resins as their representative.

Moreover, in order to maintain the heat resistance (glass transition temperature) of an epoxy resin hardened | cured material, and to improve toughness, there may be a case where the polyvinyl acetal in which the carboxyl group was introduce | transduced is uniformly compatible with an epoxy resin. In addition, a typical polyvinyl acetal used as a toughening agent for a composite material is a polyvinyl formal resin. In order to make the polyvinyl formal resin compatible uniformly in the epoxy resin, heating must be performed at a temperature of 130 ° C. or higher, and the trouble of the dissolution step and the heat history in the dissolution step are also worried. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Special Fair 4-15253 [Patent Document 2] Japanese Patent Special Fair 4-80054 [Non-Patent Document]

[Non-Patent Document 1] General Introduction to Epoxy Resin Volume 4 Application II Page 187, edited by Epoxy Resin Technology Association

[Problems to be Solved by the Invention] In order to obtain a toughening effect of an epoxy resin hardened material by a polyvinyl formal resin, it is necessary to uniformly dissolve the polyvinyl formal resin in an epoxy resin. However, when a polyvinyl formal resin is dissolved in an epoxy resin, it must be heated from 130 ° C to 150 ° C. An object of the present invention is to provide composite particles having good solubility in an epoxy resin even at 120 ° C or lower. [Means for solving problems]

In order to improve the solubility of the polyvinyl formal resin in the epoxy resin, the inventors can knead the liquid with a liquid epoxy resin instead of melting the polyvinyl formal resin having fine pores. Liquid epoxy resin is filled in the pores to obtain composite particles that are easily dissolved in the epoxy resin.

That is, this invention is as follows.

[1] A composite particle in which the pores of particles in component A are filled with component B, and the content ratio of component A is 50% to 99% by weight, and the content ratio of component B is 1% to 50% by weight %, Component A: polyvinyl formal resin; component B: liquid epoxy resin.

[2] The composite particle according to [1], wherein the polyvinyl formal resin of component A is a compound including a structural unit a, a structural unit b, and a structural unit c,

[3] The composite particle according to [1] or [2], wherein the polyvinyl formal resin of component A is a compound further including a constituent unit d, In the formula constituting unit d, R ^{1 is} independently hydrogen or an alkyl group having 1 to 5 carbon atoms.

[4] The composite particle according to any one of [1] to [3], wherein the polyvinyl formal resin of component A is granular, and has 0.1 ml / g to 0.9 ml / g of Pore volume, particle diameters range from 10 μm to 2000 μm.

[5] The composite particles according to any one of [1] to [4], wherein the liquid epoxy resin of the component B is liquid at least at 100 ° C.

[6] The composite particle according to any one of [1] to [5], wherein the liquid epoxy resin of the component B is a compound having at least one ethylene oxide group.

[7] The composite particle according to any one of [1] to [6], wherein the liquid epoxy resin of the component B is a liquid epoxy resin and is obtained by mixing at least two liquid epoxy resins Or by dissolving at least one solid epoxy resin in at least one liquid epoxy resin.

[8] The method for producing composite particles according to any one of [1] to [7], which does not melt the polyvinyl formal resin as component A, but melts with the liquid ring as component B Oxygen resin kneading. [Effect of the invention]

According to the present invention, it is possible to provide composite particles of a polyvinyl formal resin which can be easily dissolved in an epoxy resin and an epoxy resin, and a method for producing the same.

The aspect of the present invention is a composite particle. This composite particle is characterized in that the polyvinyl formal resin having pores is not melted, but is kneaded with a liquid epoxy resin, and the pores are filled with the liquid epoxy resin.

The composite particles of the present invention include a polyvinyl formal resin of component A and a liquid epoxy resin of component B. Component B may contain a reactive diluent.

The content of the polyvinyl formal resin of the component A in the composite particles is 50 to 99% by weight, and preferably 70 to 90% by weight. When the content of the polyvinyl formal resin of the component A is 50% by weight or more, the content of the liquid epoxy of the component B decreases, and the composite can be handled in a particulate form, thereby improving the operability. Furthermore, since the liquid component is reduced, it is preferable to prevent the agglomeration of particles due to the dissolution of the surface of the composite particles during storage, to prevent the particles from becoming agglomerated, and to prevent a decrease in the solubility in the epoxy resin. When the content of the polyvinyl formal resin of the component A is 99% by weight or less, it is preferable to obtain composite particles that are easily dissolved in an epoxy resin as a subject of the present invention.

The content of the liquid epoxy resin of the component B in the composite particles is 1 to 50% by weight, and preferably 10 to 30% by weight. When the content of the epoxy resin of the component B is 50% by weight or less, the composite can be handled in the form of particles, and the workability is improved. Furthermore, when the liquid epoxy resin of the component B is more than 1% by weight, the surface of the composite particles is inhibited from being dissolved during storage, the particles are prevented from agglomerating, and they do not become agglomerated, preventing the dissolution in the epoxy resin Decreased properties are preferred. When the content of the epoxy resin of the component B is 1% by weight or more, it is preferable to obtain composite particles that are easily dissolved in the epoxy resin, which is a subject of the present invention.

The polyvinyl formal resin of the component A in the present invention preferably contains the following constituent units a, constituent units b, and constituent units c. Furthermore, the structural unit d may be included.

The total content of the constituent units a to d in the polyvinyl formal resin of the component A is preferably 80% to 100% with respect to all the constituent units. Examples of other constituent units that may be contained in the polyvinyl formal resin of the component A include an intermolecular formal or a hemiformal unit. The content ratio of the vinyl formal chain unit other than the structural unit a is preferably less than 5 mol%.

The structural unit a is a structural unit having a formal, and can be formed by a reaction between a continuous polyvinyl alcohol chain unit and formaldehyde (HCHO). The structural unit b is a structural unit including a vinyl acetate chain. The structural unit c is a structural unit including a vinyl alcohol chain. The structural unit d is a chain having a carboxyl group, and R ¹ in the chemical formula is preferably hydrogen or an alkyl group having 1 to 5 carbon atoms, and more preferably hydrogen or an alkyl group having 1 to 3 carbon atoms.

In the polyvinyl formal resin of the component A, the constituent units a to d may be arranged regularly (block copolymer, alternating copolymer, etc.) or may be arranged randomly (random copolymer), but it is preferably Are randomly arranged.

Each constituent unit in the polyvinyl formal resin of the component A is preferably: the content rate of the constituent unit a is 49.9 mol% to 80 mol%, the content rate of the constituent unit b is 0.1 mol% to 49.9 mol%, and the constituent unit c And the content rate of the constituent unit d is from 0 mol% to 49.9 mol%. More preferably, the content rate of the constituent unit a is 49.9 mol% to 80 mol%, the content rate of the constituent unit b is 1 mol% to 30 mol%, and the content rate of the constituent unit c is 1 mol% to 30 mol%, and The content rate of the constituent unit d is 0 mol% to 30 mol%.

In order to fully obtain the chemical resistance, flexibility, abrasion resistance, and mechanical strength of the polyvinyl formal resin of component A, the content rate of the constituent unit a is preferably 49.9 mol% or more. In addition, the structural unit a in the polyvinyl formal resin of the component A is formed by formalizing a vinyl alcohol chain component continuously present in a molecular chain. That is, it is difficult to formalize a discontinuous vinyl alcohol chain in the molecular chain (for example, one vinyl alcohol chain sandwiched between two vinyl formal chains). Therefore, in the synthesis, the content rate of the constituent unit A is preferably 80.0 mol% or less.

When the content rate of the structural unit a is 0.1 mol% or more, the solubility of the polyvinyl formal resin of the component A in a solvent or the solubility in an epoxy resin becomes good. When the content rate of the constituent unit b is set to 49.9 mol%, it is difficult to reduce the chemical resistance, flexibility, abrasion resistance, and mechanical strength of the polyvinyl formal resin of the component A, which is preferable.

In consideration of solubility in a solvent or solubility in an epoxy resin, the constituent unit c is preferably set to a content rate of 49.9 mol%. In addition, in the production of the polyvinyl formal resin of component A, when the polyvinyl alcohol chain is formalized, the constitutional unit b and the constitutional unit c have a balanced relationship. Therefore, the content rate of the constitutional unit c is preferably 0.1 mol. %the above.

In consideration of good viscosity and solubility in epoxy resin, the content of the constituent unit d is preferably 49.9 mol% or less. In addition, in order to obtain a hardened epoxy resin which is excellent in toughness while maintaining heat resistance (glass transition temperature) by a cross-linking reaction between the side chain carboxyl group and the epoxy resin, the content of the constituent unit d is preferably 0.1. More than mol%.

The weight-average molecular weight of the polyvinyl formal resin of component A is preferably 5,000 to 300,000, and more preferably 10,000 to 150,000. When the weight-average molecular weight of the polyvinyl formal resin of the component A is 5,000 or more, the solubility of the polyvinyl formal resin in the epoxy resin is improved, and the polyacetal resin obtained by the polyvinyl formal resin is obtained. Toughening effect is preferred. On the other hand, when the weight average molecular weight is 300,000 or less, the viscosity during dissolution does not increase excessively, and it is preferable in terms of workability during molding.

The polyvinyl formal resin of component A was granular, and many voids were observed in the particles (FIG. 1). Preferably, it has a pore volume of 0.1 ml / g to 0.9 ml / g inside the particles. The composite particles of the present invention are obtained by impregnating a liquid epoxy resin into the pores. When the liquid epoxy resin is filled in the pores in advance, the solubility when added to the epoxy resin is improved. In addition, when the pore volume is 0.1 ml / g or more, it is easy to obtain the composite particles of the present invention that are easily dissolved in an epoxy resin. The upper limit of the pore volume is not particularly limited, but is preferably about 0.9 ml / g.

The polyvinyl formal resin of component A is granular. Its particle diameter is preferably 10 μm to 2000 μm, and more preferably 100 μm to 1500 μm. When the particle diameter is 10 μm or more, the surface area per unit mass of the polyvinyl formal resin particles of the component A is insufficient. Therefore, the liquid epoxy resin of the component B does not adhere to the surface of the particles, but is sufficiently impregnated in the particles. In the pores, there is no case where the surface of the polyvinyl formal resin particles of the component A is dissolved by the liquid epoxy resin of the component B and the composite particles are agglomerated, so that the particles can be easily dissolved in the epoxy resin. Composite particles are therefore preferred. When the particle diameter is 2000 μm or less, it does not take time to dissolve the composite particles in the epoxy resin, and it is a feature of the present invention that it is a composite particle that is easily dissolved in the epoxy resin and is therefore preferred. The liquid epoxy resin of the component B is preferably a liquid epoxy resin at least at 100 ° C, and in consideration of work at room temperature, it is more preferably a liquid epoxy resin at 25 ° C.

When the temperature at which the epoxy resin of the component B becomes liquid is 100 ° C. or lower, when it is mixed with the polyvinyl formal resin of the component A, a part of the polyvinyl formal resin can be suppressed from melting in the epoxy resin. It is preferable to hold composite particles.

The type of the liquid epoxy resin of the component B is not particularly limited as long as it is liquid at 100 ° C, but it is preferably an epoxy resin that is easily mixed with a polyvinyl formal resin. Moreover, even if it is a solid epoxy resin, if it mixes with a liquid epoxy resin and it is liquid at 100 degreeC, it can be used for this invention. Epoxy resin is a compound having two or more epoxy groups in the molecule, and can be used: bisphenol epoxy resin, phenol novolac epoxy resin, cresol novolac epoxy resin, glycidylamine ring Oxygen resin, isocyanate modified epoxy resin, urethane modified epoxy resin, alicyclic epoxy resin, biphenyl epoxy resin, naphthalene epoxy resin, dicyclopentadiene epoxy resin,芴 -type epoxy resin and so on. These epoxy resins can be used individually or in combination of 2 or more types.

Regarding bisphenol epoxy resin, there are: bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol AD epoxy resin, bisphenol S epoxy resin, brominated bisphenol A epoxy resin Resin, etc. As bisphenol A type epoxy resin, Mitsubishi Chemical Corporation products include: jER827, jER828, jER834, jER1001, jER1002, jER1003, jER1004, jER1055, jER1007, jER1009, jER1010. DIC products include: Epiclon 840, Epiclon 850, Epiclon 860, Epiclon 1050, Epiclon 1055, Epiclon 2050, Epiclon 3050, Todo Chemical Co., Ltd. Products include: Epotohto YD-127, Epotohto YD-128, Ebert (Epotohto) YD-134. As bisphenol F-type epoxy resin, products of Mitsubishi Chemical Corporation include: jER806, jER807, jER4004P, jER4005P, jER4007P, jER4010P, etc. The products of DIC include Epiclon 830, and the products of Dongdu Chemical Co., Ltd. include: Epotohto YD-170, Epotohto YD-2001, Ebert (Epotohto) YD-2004, Epotohto YD-2005RL. The bisphenol S type epoxy resin includes: Epiclon EXA-1514, Epiclon EXA-1515, etc. manufactured by DIC Corporation.

Brominated bisphenol A epoxy resin contains: jER 5046B80, jER 5047B75, jER 5050T60, jER 5050, jER 5051, or Epiclon 152 manufactured by Mitsubishi Chemical Corporation. , Epiclon (153). Phenol novolac epoxy resins include: jER152, jER154 manufactured by Mitsubishi Chemical Corporation, or Epiclon N-740, Epiclon N-770 manufactured by DIC Corporation Epiclon N-775; Todo Chemical Co., Ltd. products include Epotohto YDPN-638 and so on.

Cresol novolac-type epoxy resins include: Epiclon N-660, Epiclon N-665, Epiclon N-670, manufactured by DIC Corporation, Epiclon N-673, Epiclon N-695, or EOCN-1020, EOCN-102S, EOCN-104S, etc. manufactured by Nippon Kayaku Co., Ltd.

Glycidylamine-based epoxy resins include: ELM-120, ELM-434, ELM-434HV, manufactured by Sumitomo Chemical Co., Ltd., Epiclon 430-L, manufactured by DIC Corporation Clone (Epiclon) 430, or Epotohto YH-434, Epotohto YH-434L, or JER604 of Mitsubishi Chemical Corporation, or Nippon Kayaku Co., Ltd. GAN and GOT produced by the company.

Isocyanate-modified epoxy resins or urethane-modified epoxy resins include: AER4152 manufactured by Asahi Kasei Epoxy Co., Ltd., or ACR1348 manufactured by ADEKA Co., Ltd. and the like.

The alicyclic epoxy resin includes: Celloxide 2021, Celloxide 2080, etc. manufactured by Daicel Chemical Industries Co., Ltd.

Biphenyl epoxy resins include: jER XY4000, jER YL6121H, jER YL6640 manufactured by Mitsubishi Chemical Corporation, or NC-3000 manufactured by Nippon Kayaku Co., Ltd.

Naphthalene-type epoxy resins include: Epiclon HP4032 manufactured by DIC Corporation, or NC-7000 and NC-7300 manufactured by Nippon Kayaku Co., Ltd. Dicyclopentadiene type epoxy resins include: Epiclon HP7200, Epiclon HP7200L, Epiclon HP7200H, or Nippon Kayaku Co., Ltd. XD-1000-1L, XD-1000-2L, etc.

The liquid epoxy resin of the component B is a compound having at least one ethylene oxide group, and may contain a reactive diluent. The reactive diluent preferably has a lower molecular weight than a general epoxy resin, and the viscosity at 25 ° C is 2 mPa · s to 100 mPa · s. By adding a reactive diluent, composite particles that can be more easily dissolved in an epoxy resin can be obtained. In addition, by not excessively adding a large amount, melting of the surface of the polyvinyl formal particles of the component A is suppressed, and the agglomeration of the particles is prevented from being fused.

Reactive diluents include the following compounds as monoepoxides. There are alcohol-based allyl glycidyl ether, n-butyl glycidyl ether, 2-ethylhexyl glycidyl ether, and higher alcohol glycidyl ether. Phenols are: phenyl glycidyl ether, p-third butylphenyl glycidyl ether, tolyl glycidyl ether, phenol (EO) ₅ glycidyl ether, second butyl glycidyl ether, cardanol diglycidyl ether. Glyceryl ether, dibromophenyl glycidyl ether. Other compounds are: glycidyl methacrylate, styrene oxide, glycidyl tertiary carboxylic acid.

Reactive diluents as diepoxides include: N, N'-diglycidylaniline, N, N-diglycidyl-O-toluidine, hexahydrophthalic anhydride diglycidyl ester, Polyethylene glycol diglycidyl ether (n = 2 ～ 13), ethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether (n = 3 ～ 11), neopentyl glycol diglycidyl ether, 1,6 -Hexanediol diglycidyl ether, resorcinol diglycidyl ether, diglycidyl-O-phthalate, dibromo neopentyl glycol diglycidyl ether.

Reactive diluents include glycerol polyglycidyl ether and trimethylolpropane polyglycidyl ether as triepoxides.

As the liquid epoxy resin of the component B, one liquid epoxy resin or a mixture of at least two epoxy resins may be used. In addition, at least one solid epoxy resin may be dissolved in at least one liquid epoxy resin and used.

The method of kneading the polyvinyl formal resin of the component A and the epoxy resin of the component B is not particularly limited as long as the components can be uniformly kneaded, and a high-speed mixer, a belt blender, and a planetary are preferred. Mixer, kneader, etc. The temperature for kneading the polyvinyl formal resin of component A and the epoxy resin of component B is preferably 0 ° C to 100 ° C. It is more preferably 20 ° C to 50 ° C. Kneading at room temperature is most suitable for workability. [Example]

Hereinafter, embodiments of the present invention will be described by way of examples, which are examples of the embodiments, and the present invention is not limited to the examples. The polyvinyl formal resins used in Examples 1 to 4 and Comparative Examples 1 to 2 are PVF-K types (weight average) of Vinylec (trademark) manufactured by JNC Corporation. Molecular weight is 50,000), and the polyvinyl formal resin used in Example 5 and Comparative Examples 3 to 4 is a PVF-E type (weight average molecular weight) of Vinylec (trademark) manufactured by JNC Co., Ltd. Is 100,000). Regarding the average particle diameter of the batch used in this evaluation, PVF-K was 342 μm, and PVF-E was 717 μm. The porosity of the pores was 0.71 ml / g, which was obtained from a cross-sectional photograph of representative particles having an average particle diameter close to 342 μm.

[Example 1] <Production of composite particles using a high-speed mixer> 2000 g of a polyvinyl formal resin (Vinylec (trademark), grade: PVF-K, manufactured by JNC Co., Ltd.) Add 500 g of bisphenol A epoxy resin (jER828 (trademark) manufactured by Mitsubishi Chemical Corporation) from the upper part of the high-speed mixer to the high-speed mixer while stirring at 1000 rpm. Stirring was continued for 15 minutes to produce composite particles.

<Dissolution test of composite particles in epoxy resin> 12.5 g of the prepared composite particles was added to a 200 mL beaker with 87.5 g of jER828 (trademark) weighed in advance, and a laboratory mixer was used at 120 rpm. While stirring, the solubility was visually confirmed at 90 ° C. The content of the polyvinyl formal resin in the dissolved solution was 10% by weight. <Dissolution result> The dissolution of the composite particles was confirmed at 90 minutes from the start of dissolution.

[Example 2] <Production of composite particles using a high-speed mixer> 2000 g of a polyvinyl formal resin (Vinylec (trademark), grade: PVF-K, manufactured by JNC Co., Ltd.) was charged. In a high-speed mixer, 475 g of bisphenol A epoxy resin (jER828 (trademark) manufactured by Mitsubishi Chemical Corporation) and a reactive diluent are added from the upper part of the high-speed mixer while stirring at 1000 rpm. 25 g of a 1,6-hexanediol diglycidyl ether (Denacol EX212 (trademark) manufactured by Nagase ChemteX Co., Ltd.) was continued at room temperature. Stir for 15 minutes to produce composite particles.

<Dissolution test of composite particles in epoxy resin> 12.5 g of the prepared composite particles was added to a 200 mL beaker with 87.5 g of jER828 (trademark) weighed in advance, and a laboratory mixer was used at 120 rpm. While stirring, the solubility was visually confirmed at 90 ° C. The content of the polyvinyl formal resin in the dissolved solution was 10% by weight. <Dissolution result> The dissolution of the composite particles was confirmed at 80 minutes from the start of dissolution.

[Example 3] <Production of composite particles using a high-speed mixer> 2000 g of a polyvinyl formal resin (Vinylec (trademark), grade: PVF-K, manufactured by JNC Co., Ltd.) In a high-speed mixer, while stirring at 1000 rpm, 450 g of bisphenol A epoxy resin (jER828 (trademark) manufactured by Mitsubishi Chemical Corporation) was added from the top of the high-speed mixer and as a reactive diluent. 50 g of a mixture of 1,6-hexanediol diglycidyl ether (Denacol EX212 (trademark) manufactured by Nagase ChemteX Co., Ltd.) was continued at room temperature. Stir for 15 minutes to produce composite particles.

<Dissolution test of composite particles in epoxy resin> 12.5 g of the prepared composite particles was added to a 200 mL beaker with 87.5 g of jER828 (trademark) weighed in advance, and a laboratory mixer was used at 120 rpm. While stirring, the solubility was visually confirmed at 90 ° C. The content of the polyvinyl formal resin in the dissolved solution was 10% by weight. <Dissolution result> The dissolution of the composite particles was confirmed at 70 minutes from the start of dissolution.

[Example 4] <Production of composite particles using a high-speed mixer> 2000 g of a polyvinyl formal resin (Vinylec (trademark), grade: PVF-K, manufactured by JNC Co., Ltd.) was charged. In a high-speed mixer, while stirring at 1000 rpm, add 375 g of bisphenol A epoxy resin (jER828 (trademark) manufactured by Mitsubishi Chemical Corporation) from the upper part of the high-speed mixer and as a reactive diluent. Of 125 g of 1,6-hexanediol diglycidyl ether (Denacol EX212 (trademark) manufactured by Nagase ChemteX Co., Ltd.), and continued at room temperature. Stir for 15 minutes to produce composite particles.

<Dissolution test of composite particles in epoxy resin> 12.5 g of the prepared composite particles was added to a 200 mL beaker with 87.5 g of jER828 (trademark) weighed in advance, and a laboratory mixer was used at 120 rpm. While stirring, the solubility was visually confirmed at 90 ° C. The content of the polyvinyl formal resin in the dissolved solution was 10% by weight. <Dissolution result> The dissolution of the composite particles was confirmed 45 minutes after the start of dissolution.

[Example 5] <Production of composite particles using a high-speed mixer> 2000 g of a polyvinyl formal resin (Vinylec (trademark), grade: PVF-E, manufactured by JNC Co., Ltd.) was charged. Add 500 g of bisphenol A epoxy resin (jER828 (trademark) manufactured by Mitsubishi Chemical Corporation) from the upper part of the high-speed mixer to the high-speed mixer while stirring at 1000 rpm. Stirring was continued for 15 minutes to produce composite particles.

<Dissolution test of composite particles in epoxy resin> 12.5 g of the prepared composite particles was added to a 200 mL beaker with 87.5 g of jER828 (trademark) weighed in advance, and a laboratory mixer was used at 120 rpm. While stirring, the solubility was visually confirmed at 120 ° C. The content of the polyvinyl formal resin in the dissolved solution was 10% by weight. <Dissolution result> The dissolution of the composite particles was confirmed at 180 minutes from the start of dissolution. [Comparative Example 1] <Comparative Particles> 10 g of polyvinyl formal resin (Vinylec manufactured by JNC Co., Ltd. was weighed instead of blending with a liquid epoxy resin using a high-speed mixer. ) (Trademark), grade: PVF-K).

<Comparison of dissolution test of particles in epoxy resin> 10 g of polyvinyl formal resin was weighed into a 200 mL beaker with 90 g of jER828 (trademark), and a laboratory mixer was used. While stirring at 120 rpm, solubility was visually confirmed at 90 ° C. The content of the polyvinyl formal resin in the dissolved solution was 10% by weight. <Dissolution result> After 6 hours, the remaining of the undissolved polyvinyl formal resin was also confirmed.

[Comparative Example 2] <Comparative particles> 10 g of polyvinyl formal resin (Vinylec manufactured by JNC Co., Ltd.) was weighed without blending with a liquid epoxy resin using a high-speed mixer. ) (Trademark), grade: PVF-K).

<Comparison of dissolution test of particles in epoxy resin> 10 g of polyvinyl formal resin was weighed and added to a 200 mL beaker with jER828 (trademark) weighed in advance, and a laboratory mixer was used. While stirring at 120 rpm, solubility was visually confirmed at 130 ° C. The content of the polyvinyl formal resin in the dissolved solution was 10% by weight. <Dissolution result> The dissolution of the polyvinyl formal resin was confirmed at 130 ° C at 90 minutes from the start of dissolution.

[Comparative Example 3] <Comparative Particles> 10 g of polyvinyl formal resin (Vinylec manufactured by JNC Co., Ltd.) was weighed without blending with a liquid epoxy resin using a high-speed mixer. ) (Trademark), Grade: PVF-E). <Comparison of dissolution test of particles in epoxy resin> 10 g of polyvinyl formal resin was weighed and added to a 200 mL beaker with jER828 (trademark) weighed in advance, and a laboratory mixer was used. While stirring at 120 rpm, solubility was visually confirmed at 120 ° C. The content of the polyvinyl formal resin in the dissolved solution was 10% by weight. <Dissolution result> After 6 hours, the remaining of the undissolved polyvinyl formal resin was also confirmed.

[Comparative Example 4] <Comparative Particles> 10 g of polyvinyl formal resin (Vinylec manufactured by JNC Co., Ltd. was weighed instead of blending with a liquid epoxy resin using a high-speed mixer. ) (Trademark), Grade: PVF-E). <Comparison of dissolution test of particles in epoxy resin> 10 g of polyvinyl formal resin was weighed and added to a 200 mL beaker with jER828 (trademark) weighed in advance, and a laboratory mixer was used. While stirring at 120 rpm, solubility was visually confirmed at 150 ° C. The content of the polyvinyl formal resin in the dissolved solution was 10% by weight. <Dissolution result> The dissolution of the polyvinyl formal resin was confirmed at 150 ° C. for 180 minutes from the start of dissolution.

The experimental results are summarized in Tables 1 to 4.

Table 1. Composition of composite particles of Examples 1 to 4 and polyvinyl formal resins of Comparative Examples 1 to 2

Table 2. Composite particle composition of Example 5 and polyvinyl formal resins of Comparative Examples 3 to 4

Table 3. Evaluation results of the solubility of the composite particles of Examples 1 to 4 and the polyvinyl formal resins of Comparative Examples 1 to 2 in epoxy resins Solubility: ○ means dissolution. ×: Inadequate dissolution. *: Even after 360 minutes, it cannot be dissolved.

Table 4. Composite particle composition of Example 5 and results of evaluation of solubility of the polyvinyl formal resin in Comparative Examples 3 to 4 in epoxy resins Solubility: ○ means dissolution. ×: Inadequate dissolution. *: Dissolved even after 360 minutes.

From Tables 1 and 3, it can be confirmed that the composite particles (weight average molecular weight: 50,000) of the examples have better solubility in epoxy resins at 90 ° C than the polyvinyl formal resin particles of Comparative Example 1. It was also confirmed that if the content of the reactive diluent is increased, the dissolution time can be shortened. From Tables 2 and 4, it can be confirmed that the composite particles (weight average molecular weight: 100,000) of the examples have better solubility in epoxy resins at 120 ° C than the polyvinyl formal resin particles of Comparative Example 3.

In the case of a polyvinyl formal resin having a weight-average molecular weight of 50,000, it is found that a dissolution temperature of 130 ° C. is required as in Comparative Example 2. However, by using the composite particles of the present invention, the dissolution temperature is 100 ° C. or less . In the case of a polyvinyl formal resin having a weight-average molecular weight of 100,000, it is found that a dissolution temperature of 150 ° C is required as in Comparative Example 4. However, when the composite particles of the present invention are used, the temperature is as low as 120 ° C. Dissolve under. [Industrial availability]

The composite particles of the present invention can be used as a toughening agent for a carbon fiber composite material.

no

FIG. 1 is a 350-fold microscope photograph of the polyvinyl formal resin particles of component A. FIG.

Claims (8)

A composite particle in which the pores of particles in component A are filled with component B, and the content ratio of component A is 50% to 99% by weight, and the content ratio of component B is 1% to 50% by weight %, The component A: a polyvinyl formal resin; the component B: a liquid epoxy resin. The composite particle according to item 1 of the scope of the patent application, wherein the polyvinyl formal resin of the component A is a compound including a structural unit a, a structural unit b, and a structural unit c, . The composite particle according to item 1 or item 2 of the scope of patent application, wherein the polyvinyl formal resin of the component A is a compound further including a constituent unit d, In the formula constituting unit d, R ^{1 is} independently hydrogen or an alkyl group having 1 to 5 carbon atoms. The composite particle according to item 1 or item 2 of the scope of patent application, wherein the polyvinyl formal resin of the component A is granular and has pores of 0.1 ml / g to 0.9 ml / g inside the particle Volume, particle diameters range from 10 μm to 2000 μm. The composite particle according to item 1 or item 2 of the patent application scope, wherein the liquid epoxy resin of the component B is liquid at least at 100 ° C. The composite particle according to item 1 or item 2 of the scope of patent application, wherein the liquid epoxy resin of the component B is a compound having at least one ethylene oxide group. The composite particle according to item 1 or item 2 of the scope of patent application, wherein the liquid epoxy resin of the component B is a liquid epoxy resin and a mixture of at least two liquid epoxy resins Or by dissolving at least one solid epoxy resin in at least one liquid epoxy resin. A method for producing a composite particle, which is the method for producing a composite particle according to any one of claims 1 to 7 of the scope of application for a patent, without melting the polyvinyl formal resin as the component A, and It is kneaded with the liquid epoxy resin as the B component.