JP2021138924A - Coating agent and intermediate base material - Google Patents

Abstract

To provide a surface protective material which is rich in UV resistance, can protect a surface of a prepreg as a base material, prevents degradation by UV of a fiber-reinforced composite material and can prevent defects in coating, can control a resin flow, and has a small amount of volatilization in curing.SOLUTION: A coating agent for spraying or hand coating that is composed of an epoxy resin composition containing at least components [A] to [D] contains 90-100 pts.mass of [A], 15-75 pts.mass of [B], 0.05-75 pts.mass of [C] and 0.1-10 pts.mass of [D] with respect to 100 pts.mass of the whole epoxy resin. [A] Non-aromatic epoxy resin. [B] Pigment having an average particle diameter of 0.1-10 μm. [C] Non-aromatic thermoplastic resin. [D] Cationic or anionic curing agent.SELECTED DRAWING: None

Description

The present invention relates to a coating agent for spraying or hand coating, which comprises an epoxy resin composition having excellent light resistance, and an intermediate base material obtained by applying the coating agent to a surface of a metal or the like.

For products that require high structural performance such as aircraft structural members, windmill blades, automobile outer panels, IC trays, laptop housings, and other computer applications, reinforced fibers such as carbon fiber and thermosetting resin such as epoxy resin are used. A prepreg made by impregnating with a resin is often used. However, the fiber composite material obtained by curing a general prepreg has low light resistance (UV resistance) and deteriorates and denatures when the surface is exposed to light. Therefore, in recent years, there has been an increasing demand for imparting light resistance to the surface of fiber composite materials.

Patent Document 1 discloses a sheet material having a UV shielding property as a surface protective film of a fiber composite material. Further, Patent Document 2 discloses a combination of an epoxy resin containing no aromatic ring, a carboxylic acid anhydride also containing no aromatic ring, and an ultraviolet absorber as a resin composition having UV resistance. Non-aromatic epoxies are generally small molecules and have weak intramolecular interactions, so that they have a low viscosity and are easily volatilized.

Special Table 2015-507648 International Publication No. 2003/002661

However, in the technique disclosed in Patent Document 1, there is a problem that the epoxy resin composition used as the film material contains an aromatic ring and the film material itself has poor UV resistance. Further, in the technique disclosed in Patent Document 2, since the carboxylic acid anhydride is applied as a curing agent for the epoxy resin composition, the handleability as a surface protective material, the control of the resin flow, and the suppression of volatilization during curing are suppressed. Therefore, there was a problem that the degree of design freedom was low.

Therefore, it is highly UV resistant, it is possible to protect the surface of the prepreg that is the base material, it is possible to prevent deterioration of the fiber reinforced composite material due to UV, and it is possible to prevent defects during painting, and it is possible to prevent defects in the resin flow. The challenge is to realize a surface protective material that can be controlled and has a small amount of volatilization during curing.

The present invention has the following configuration in order to solve such a problem. That is, the coating agent of the present invention is a coating agent for spraying or hand-coating, which comprises an epoxy resin composition containing at least the components [A] to [D], with respect to 100 parts by mass of the total epoxy resin [ A] is 90 to 100 parts by mass, [B] is 15 to 75 parts by mass, [C] is 0.05 to 75 parts by mass, and [D] is 0.1 to 10 parts by mass.
[A] Non-aromatic epoxy resin [B] Pigment with an average particle size of 0.1 to 10 μm [C] Non-aromatic thermoplastic resin [D] Cationic or anionic curing agent.

Further, the intermediate base material of the present invention is obtained by applying the coating agent to the surface of a metal, a carbon fiber reinforced composite material precursor, or a carbon fiber reinforced composite material.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a coating agent using an epoxy resin composition having excellent light resistance. Further, when the coating agent is applied to the surface of a metal, a carbon fiber reinforced composite material precursor or a carbon fiber reinforced composite material and integrated, an intermediate base material having a light resistant surface can be provided.

The coating agent of the present invention has the following constitution.

A coating agent for spraying or hand-coating, which comprises an epoxy resin composition containing at least the components [A] to [D], and 90 to 100 parts by mass of [A] with respect to 100 parts by mass of the total epoxy resin. A coating agent containing 15 to 75 parts by mass of [B], 0.05 to 75 parts by mass of [C], and 0.1 to 10 parts by mass of [D].
[A] Non-aromatic epoxy resin [B] Pigment with an average particle size of 0.1 to 10 μm [C] Non-aromatic thermoplastic resin [D] Cationic or anionic curing agent.

The component [A] according to the present invention is a non-aromatic epoxy resin. Here, the "aromatic" includes an aromatic hydrocarbon or a conjugated unsaturated heterocyclic compound in the chemical structure, and the others are "non-aromatic". That is, the non-aromatic epoxy resin refers to an epoxy resin that does not contain an aromatic hydrocarbon group or an unsaturated heterocycle in its chemical structure. Examples of non-aromatic epoxy resins include tetrahydroindene diepoxides, vinylcyclohexene oxides, and (3', 4'-epoxycyclohexane) methyl 3,4-epoxy as alicyclic epoxy resins (epoxy resins containing cycloalkane rings). Cyclohexanecarboxylate, dipentenedioxide, bis adipate (3,4-epoxycyclohexylmethyl), dicyclopentadienedioxide, bis (2,3-epoxycyclopentyl) ether, 2,2-bis (hydroxymethyl) -1- Butanol 1,2-epoxy-4- (2-oxylanyl) cyclohexane adduct, tetrakis- (3-cyclohexenylmethyl) epoxidized butanetetracarboxylic acid-modified epsilon-caprolactone, bi-7-oxabicyclo [4.1. 0] Heptane, dodecahydrobisphenol A diglycidyl ether, dodecahydrobisphenol F diglycidyl ether, 1,4-cyclohexanedimethanol diglycidyl ether, hexahydrophthalic acid diglycidyl ester, hexahydroterephthalic acid diglycidyl ester, 2,2 -Bis (4-hydroxycyclohexyl) propane diglycidyl ether (generic name: hydrogenated bisphenol A type liquid epoxy resin), aromatic ring, amine nitrogen atom, cycloalkane ring, epoxy resin containing no cycloalkene ring Specific examples include ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,4-butanediol glycidyl ether, 1,6-hexanediol diglycidyl ether, neopentylene glycol diglycidyl ether, glycerol polyglycidyl ether, and diglycerol. Monofunctional epoxy compound containing no polyglycidyl ether, trimethylpropan polyglycidyl ether, sorbitol polyglycidyl ether, 1,4-bis (2-oxylanyl) butane, pentaerythritol polyglycidyl ether, aromatic ring, or amine nitrogen atom Specific examples of (an epoxy compound containing only one oxylan ring) include 4-tert-butyl glycidyl ether, butyl glycidyl ether, 1-butene oxide, 1,2-epoxy-4-vinylcyclohexane, and 2-ethylhexyl glycidyl ether. And so on.

From the viewpoint of heat resistance, an alicyclic epoxy resin is preferably used as the non-aromatic epoxy resin.

Commercially available products can be used as the non-aromatic epoxy resin. For example, "Selokiside (registered trademark)" 2021P, "Selokiside (registered trademark)" 8010, "Selokiside (registered trademark)" 2000, "Epolide (registered trademark)" GT401, "Selokiside (registered trademark)" 2081, EHPE3150 ((() Daicel Chemical Industry Co., Ltd.), THI-DE (JXTG Energy Co., Ltd.), TTA21, AAT15, TTA22 (Sun Chemical Co., Ltd.), Ex-121, Ex-221, Ex-212, Ex-313, Ex-321, Ex-411 (manufactured by Nagase Chemtech Co., Ltd.), "Epolite (registered trademark)" 4000 (manufactured by Kyoeisha Chemical Co., Ltd.), ST-3000, ST-4000 (Nittetsu Chemical & Materials Co., Ltd.) ), YX8000 (manufactured by Mitsubishi Chemical Co., Ltd.), EPALOY5000 (manufactured by HUNTSMAN), and the like.

By using at least two kinds of the above non-aromatic epoxy resins, the reactivity of the epoxy resin composition can be controlled, and a good balance between the fast curing property of the epoxy resin composition and the pot life can be obtained.

High light resistance (UV resistance) can be obtained by containing 90% by mass or more of the non-aromatic epoxy resin with respect to the entire epoxy resin composition.

Further, when only an alicyclic epoxy resin is used for the epoxy resin composition, a cured epoxy resin having a high glass transition temperature while having UV resistance can be obtained.

The component [B] is a pigment (average particle size 0.1 to 10 μm). Examples of pigments are barium sulfate, zinc sulfide, titanium oxide, molybdenum red, cadmium red, chromium oxide, titanium yellow, cobalt green, cobalt blue, ultramarine, barium titanate, carbon black, iron oxide, red phosphorus, copper chromate. And so on. The average particle size of the pigment needs to be 0.1 to 10 μm, preferably 0.1 to 5 μm, more preferably 0.3 to 5 μm, to obtain an epoxy resin composition having high UV shielding properties. can. Here, the average particle size is measured using LA-950 (manufactured by HORIBA, Ltd.) using a laser diffraction / scattering method. The result of volume conversion measured using "Araldite (registered trademark)" GY282 (ingredient: bisphenol F type epoxy resin, manufactured by Huntsman Japan Co., Ltd.) as a dispersion medium was adopted as the particle size distribution measurement result, and the obtained particle size was obtained. The particle size (median diameter) at 50% in the cumulative curve of the distribution is defined as the average particle size.

By containing the above pigment in an amount of 15 to 75 parts by mass, preferably 25 to 55 parts by mass, and more preferably 30 to 50 parts by mass with respect to 100 parts by mass of the total epoxy resin contained in the epoxy resin composition, the light of the cured resin product is obtained. It is possible to obtain a good balance between the shielding property and the adhesion at the time of hand coating.

The component [C] is a non-aromatic thermoplastic resin. Here, the "aromatic" includes an aromatic hydrocarbon or a conjugated unsaturated heterocyclic compound in the chemical structure, and the others are "non-aromatic". That is, the non-aromatic thermoplastic resin refers to a thermoplastic resin that does not contain an aromatic hydrocarbon group or an unsaturated heterocycle in its chemical structure. Examples of non-aromatic thermoplastic resins include polyvinyl alcohol, polyvinyl acetal, polyvinyl formal, polyvinyl acetal, polyvinyl butyral, polyvinyl acetate, hydrogenated bisphenol A / pentaeristol phosphite polymer, hydrogenated terpene, hydrogenated terpene. Examples include phenol.

In particular, polyvinyl alcohol, polyvinyl formal, polyvinyl butyral, polyvinyl acetal acetal, and polyvinyl acetate, which have high solubility in non-aromatic epoxy resins, are preferable because the viscosity of the epoxy resin composition can be easily adjusted. Polyvinyl acetal acetal and polyvinyl butyral are more preferable because they have the effect of improving the elongation of the epoxy resin composition after curing. Here, the elongation refers to the bending strain (%) when the cured epoxy resin composition is bent at three points in a predetermined shape.

These non-aromatic thermoplastic resins are preferably those that can be dissolved in the epoxy resin of the component [A]. For example, as a result of adding at least 10 parts by mass of thermoplastic resin powder to 100 parts by mass of the epoxy resin of the component [A] and kneading at 100 to 120 ° C. for 1 hour, the thermoplasticity from the start. It is said that those with a decrease in the amount of resin powder can be dissolved. Weight loss means that the weight is reduced to an level that cannot be observed optically, and that when the remaining powder is recovered, the mass is reduced by 10% or more from the starting point. From the viewpoint of dissolving in the epoxy resin, it is preferable that the powder of the thermoplastic resin has at least an average particle size of 100 μm or less obtained by a laser diffraction method. Further, when the average particle size is larger than 100 nm, it is preferable that aggregation is suppressed during storage and stirring with the epoxy resin is easy.

Further, when the molecular weight of these non-aromatic thermoplastic resins is 5000 to 70000 g / mol, preferably 7000 to 65000 g / mol, and more preferably 1000 to 60000 g / mol, the uniformity of dissolution in the epoxy resin composition is determined. A good balance of the resin flow suppressing effect can be obtained. The molecular weight here means a polystyrene-equivalent weight average molecular weight by gel permeation chromagraphy using HLC-8420GPC (manufactured by Tosoh Corporation).

Commercially available products can be used as the non-aromatic thermoplastic resin. For example, "J-POVAL (registered trademark)" (manufactured by Japan Vam & Poval Co., Ltd.), "Vinirec (registered trademark)" (manufactured by JNC Co., Ltd.), "Eslek (registered trademark)" (Sekisui Chemical Co., Ltd. (Sekisui Chemical Co., Ltd.) (Manufactured by Co., Ltd.), "Ultrasen (registered trademark)" (manufactured by Tosoh Co., Ltd.) JPH-3800 (manufactured by Johoku Chemical Industry Co., Ltd.), YS Polystar UH130 (manufactured by Yasuhara Chemical Co., Ltd.) and the like.

When the epoxy resin composition is applied as a spray, the resin flow suppressing effect is obtained by containing 0.05 parts by mass or more of the non-aromatic thermoplastic resin with respect to 100 parts by mass of the total epoxy resin contained in the epoxy resin composition. Be done. The term "spray" as used herein refers to a method in which the epoxy resin composition is filled in a container and the epoxy resin composition is sprayed in the form of mist or foam by high-pressure air or mechanical movement using a nozzle. When the epoxy resin composition is applied as a spray, the amount of the spray per fixed time is increased by containing 0.05 to 1 part by mass, preferably 0.1 to 0.5 part by mass of the non-aromatic thermoplastic resin. It is preferable in that it can maintain and obtain a high resin flow suppressing effect.

Further, when the epoxy resin composition is applied by hand coating, the non-aromatic thermoplastic resin is applied in an amount of 1 to 75 parts by mass or less, preferably 5 to 65 parts by mass, more preferably 5 parts by mass, based on 100 parts by mass of the total epoxy resin. Good adhesion can be obtained by containing 10 to 55 parts by mass of the non-aromatic thermoplastic resin. The manual coating here is, for example, a method in which an epoxy resin composition is stored in a container, a brush or roller is dipped in the epoxy resin composition, and then manually applied to the target with a brush or roller, or an epoxy is applied to the target. It refers to a method in which a resin composition is placed and spread using a spatula or a bar coater.

The component [D] is a cationic curing agent or an anion curing agent. Examples of cationic curing agents include 1-naphthylmethylmethyl p-hydroxyphenylsulfonium = hexafluoroantimonate, 2-methylbenzylmethyl p-hydroxyphenylsulfonium hexafluoroantimonate, benzylmethyl p-hydroxyphenylsulfonium hexafluoroantimonate, Examples thereof include dimethyl-p-acetoxyphenyl sulfonium hexafluoroantimonate, diaryliodonium salt, boron acid fluoride piperidine, boron acid fluoride monoethylamine, diallyl iodonium salt, and sulfonium salt.

A commercially available product can be used as the cationic curing agent. For example, "ADEKA OPTON (registered trademark)" CP-77, "ADEKA OPTON (registered trademark)" CP-66 (manufactured by ADEKA Corporation), CI-2339, CI-2624 (manufactured by Nippon Soda Co., Ltd.), "Sun Aid ( "Registered Trademarks)" SI-60, "Sun Aid (Registered Trademark)" SI-80, "Sun Aid (Registered Trademark)" SI-100, "Sun Aid (Registered Trademark)" SI-150, "Sun Aid (Registered Trademark)" SI- B4, "Sun Aid (registered trademark)" SI-B5 (manufactured by Sanshin Chemical Industry Co., Ltd.), TA-100, IK-1PC (80) (manufactured by Sun Appro Co., Ltd.), boron trifluoride piperidine, trifluoride Boron monoethylamine (manufactured by Stella Chemifa Corporation) and the like can be mentioned. The cationic curing agent is preferably a photothermal cationic curing agent or a thermal cationic curing agent. A photothermal cation curing agent is one that is reactive by applying light of a certain wavelength or less such as ultraviolet rays or visible light or heat of a certain temperature or more, and a thermal cation curing agent is one that is reactive by heat. Point to. It is preferable to use a photothermal cation curing agent because it can be cured in a wide variety of environments, and a thermal cation curing agent is preferable because high storage stability can be obtained by temperature control.

Examples of anion curing agents include phosphorus hexafluoride, antimony pentafluoride, arsenic hexafluoride, tin hexachloride, iron tetrachloride, bismuth pentachloride, niobium hexachloride, and the like.

By using at least two kinds of the above-mentioned curing agents, the reactivity of the epoxy resin composition can be controlled, and a good balance between the fast curing property of the epoxy resin composition and the pot life can be obtained.

The reactivity of the coating agent composed of the epoxy resin composition can be controlled by the type and the amount of the curing agent added. When a coating agent consisting of an epoxy resin composition is applied to a fiber-reinforced composite material precursor such as prepreg and molded, the epoxy resin composition cures faster than the resin of the fiber-reinforced composite material precursor during the molding process. After the epoxy resin composition is cured, the fiber-reinforced composite material precursor resin is not mixed in the epoxy resin composition, so that a high resin amount-suppressing effect of the fiber-reinforced composite material precursor mixed in the epoxy resin composition can be obtained. preferable. Here, the DSC exothermic peak temperature of the coating agent depends on the curing temperature of the fiber-reinforced composite material precursor, but is preferably 40 ° C. or more lower than the curing temperature of the fiber-reinforced composite material precursor, and more preferably 60 ° C. or more lower. preferable. When the curing temperature of the fiber-reinforced composite material precursor is 180 ° C., it is preferable that the DSC exothermic peak temperature of the coating agent is in the range of 80 to 120 ° C. from the viewpoint of handleability.

The curing agent is fast-curing by containing 0.5 to 10 parts by mass, preferably 1 to 5 parts by mass, and more preferably 1 to 3 parts by mass with respect to 100 parts by mass of the total epoxy resin contained in the epoxy resin composition. It is possible to obtain a good balance between the resin flow during molding, the effect of suppressing the amount of volatilization, the quick curing property, the pot life and the UV resistance.

In addition, the epoxy resin composition in the present invention may contain a thixotropy-imparting agent as a component [E]. Examples of thixotropy-imparting agents include silicon dioxide, magnesium silicon sodium fluoride hydroxyoxide oxide, alkyl quaternary ammonium salts, synthetic hectorite, viscous minerals, modified bentonite, and a mixture of minerals and organically modified bentonite. ..

Commercially available products can be used as the above-mentioned thixotropy-imparting agent, and examples thereof include fumed silica (“Aerosil (registered trademark)” (manufactured by Nippon Aerosil Co., Ltd.)), “OPTIGEL (registered trademark)”, and “OPTIBENT (”. "Registered Trademark", "GARAMITE®", "LAPONITE®", "TIXOGEL®", "CRAYTONE®", "CLOISITE®" (manufactured by BYK Co., Ltd.) ), "Somasif (registered trademark)" ME-100, Micromica MK (manufactured by Katakura Corp. Agri Co., Ltd.) and the like.

The thixotropy-imparting agent is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, still more preferably 0.5 to 50 parts by mass with respect to 100 parts by mass of the total epoxy resin contained in the epoxy resin composition. By including 5 parts by mass, a good balance between the resin flow suppressing effect during molding and the adhesion property can be obtained.

Further, the epoxy resin composition in the present invention may contain a curing aid as a component [F]. Examples of the curing aid include 4-hydroxyphenyldimethylsulfonium = methylsulfate, 4- (methylthio) phenol and the like.

Commercially available products can be used as the curing aid, and examples thereof include "Sun Aid (registered trademark)" SI-S and "Sun Aid (registered trademark)" S-ME (manufactured by Sanshin Chemical Industry Co., Ltd.). Can be mentioned.

The curing aid is preferably 0.1 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, still more preferably 0.1 to 2 parts by mass with respect to 100 parts by mass of the total epoxy resin contained in the epoxy resin composition. By including 5.5 parts by mass, a good balance between the quick-curing property and the pot life of the epoxy resin composition can be obtained.

The epoxy resin composition in the present invention may contain rubber as a component [G]. Examples of rubber include natural rubber, diene-based rubber, and non-diene-based rubber. Examples of diene-based rubbers include styrene-butadiene rubber, isoprene rubber, butadiene rubber, chloroprene rubber, and acrylonitrile-butadiene rubber. Examples of non-diene rubber include butyl rubber, ethylene / propylene rubber, ethylene / propylene / diene rubber, urethane rubber, silicone rubber, and fluororubber. Non-diene rubber is preferable as the content in the epoxy resin composition in the present invention, but ethylene / propylene rubber, ethylene / propylene / diene rubber, silicone rubber, and fluororubber, which do not have a double bond in the polymer main chain, are It is particularly preferable because it has high light resistance and has little effect on the UV resistance of the epoxy resin composition of the present invention. Further, as the shape of the rubber, it is particularly preferable that it is in the form of powder because it has excellent dispersibility in the epoxy resin composition.

When the epoxy resin composition is applied as a spray, the resin flow suppressing effect and the epoxy resin composition after curing are obtained by containing 0.05 part by mass or more of the above rubber with respect to 100 parts by mass of the total epoxy resin contained in the epoxy resin composition. Since the elongation of the object is excellent, the effect of preventing cracks after painting can be obtained. Here, the elongation refers to the bending strain (%) when the cured epoxy resin composition is bent at three points in a predetermined shape, and the spray refers to filling the epoxy resin composition in a container and using a nozzle. It refers to a method of spraying an epoxy resin composition in the form of mist or foam by using high-pressure air or mechanical movement. By containing the rubber in an amount of preferably 0.05 to 1 part by mass with respect to 100 parts by mass of the total epoxy resin contained in the epoxy resin composition, a large amount of spray per fixed time can be maintained and a high resin flow suppressing effect can be obtained. Is preferable.

Further, when the epoxy resin composition is applied by hand coating, the content of the rubber is preferably 1 to 50 parts by mass with respect to 100 parts by mass of the total epoxy resin. When the rubber content is 1 part by mass or more with respect to 100 parts by mass of the total epoxy resin, the resin flow suppressing effect and the elongation of the epoxy resin composition after curing are excellent, so that the crack preventing effect after painting can be obtained. Therefore, it is preferable that the amount is 50 parts by mass or less because the adhesion between the target and the epoxy resin composition is excellent. The manual coating here is, for example, a method in which an epoxy resin composition is stored in a container, a brush or roller is dipped in the epoxy resin composition, and then manually applied to the target with a brush or roller, or an epoxy is applied to the target. It refers to a method in which a resin composition is placed and spread using a spatula or a bar coater.

Commercially available products can be used as the rubber, and examples thereof include KMP-598, KMP-600, KMP-601, KMP-602, KMP-605 (manufactured by Shin-Etsu Chemical Co., Ltd.), "Sebian (registered trademark)" (Daicel). Examples include JSR N215SL, JSR N222SH, JSR N238H, JSR N241H, JSR N250S, PN30A, PN20HA, N280 (manufactured by JSR Corporation).

The coating agent for spraying or hand coating made of the epoxy resin composition of the present invention has a volatile amount of 10 after being placed in an environment at 180 ° C. for 1 hour from the viewpoint of work environment and accurate control of thickness after molding. % Or less is preferable.

From the viewpoint of UV resistance, it is preferable that no discoloration is observed after irradiating the cured product of the epoxy resin composition according to the present invention with UV having a wavelength of 300 to 400 nm at 1000 kJ / m ^{2, and the object to be coated is protected from UV.} Is possible. Before and after the color change is not observed, the present invention shows that expression difference Delta] E ^* ab before and after UV irradiation is 4 or less, wherein difference Delta] E ^* ab is that the ultraviolet rays having a wavelength 300 to 400 nm 1000 kJ / ^{m 2} was irradiated It can be obtained by measuring the color measurement value of the cured product of the epoxy resin composition in (1) with a multi-light source spectrophotometer.

The spray or hand-coated coating agent comprising the epoxy resin composition of the present invention is applied to a metal surface and then cured by heat, or an uncured prepreg or RTM generally used for a fiber-reinforced composite material. It can be applied to the outermost surface of a material, a resin film infusion (RFI) material (also referred to as a "fiber-reinforced composite material precursor" in the present invention), and can be cured by heat together in the applied state. Here, the prepreg is a fiber-reinforced composite material precursor formed by impregnating reinforcing fibers with a thermosetting resin such as an epoxy resin, and the RTM material is made by laminating a reinforcing fiber base material in a mold and liquid thermosetting there. It is a fiber-reinforced composite material precursor formed by injecting resin and impregnating the reinforcing fiber base material. The RFI material is a thermosetting resin film laminated on the reinforcing fiber base material, and the laminated product is thermoset by heating and pressurizing. Refers to a fiber-reinforced composite material precursor formed by impregnating a reinforcing fiber base material with a sex resin. When applied to the surface of a metal, a silane coupling agent may be applied to the surface of the metal before application, and the epoxy resin composition may be applied to the surface of the metal after being treated with a light source or heat. By the treatment of the silane coupling agent, the silane coupling agent acts as a bridge between the metal surface and the coating agent of the epoxy resin composition in the present invention, and has the effect of improving the adhesiveness between the metal surface and the coating agent and the effect of the coating agent on the metal surface. The effect of improving wettability can be obtained. By curing, the cured product of the epoxy resin composition covers the surface of the cured fiber-reinforced composite material precursor, and an integrated fiber-reinforced composite material can be obtained.

As the reinforcing fibers in the fiber-reinforced composite material precursor, various carbon fibers, graphite fibers, glass fibers, aramid fibers and the like are preferably used.

The coating agent for spraying or hand-coating composed of the epoxy resin composition of the present invention is effective by being applied to a fiber-reinforced composite material precursor and thermosetting together, whereas the epoxy resin composition is applied by spraying. Alternatively, it may be hand-painted using a brush or the like or a bar coater or the like. In addition, after hand-coating, vacuuming is performed using a release film or the like to improve the adhesion between the spray or hand-painted coating agent composed of the epoxy resin composition of the present invention and the fiber-reinforced composite material precursor. It is possible.

The epoxy resin composition according to the present invention can be applied to a subject by various methods. For example, a method in which the epoxy resin composition is filled in a container and the epoxy resin composition is sprayed in the form of mist or foam by high-pressure air or mechanical movement using a nozzle, or a roller or brush is used as the coating agent of the present invention. It is also possible to soak in and apply it to the subject. Further, it is also possible to apply the coating agent of the present invention to a target by using a bar coater or a spatula. In either method, it is possible to apply the epoxy resin composition while lowering the viscosity by heating it as necessary.

As described above, the coating agent for spraying or hand coating made of the epoxy resin composition of the present invention can be applied to a target by various methods, but the preferred coating method is the epoxy resin composition. Depends on room temperature viscosity. When the room temperature viscosity of the epoxy resin composition is 100 to 500 mPa · s, application by spray is preferable. In the case of application by spray, when the room temperature viscosity is 100 mPa · s or less, the resin flow at room temperature can be suppressed and the thickness of the coating agent can be kept uniform, while the room temperature viscosity is 500 mPa · Pa or less. When the epoxy resin composition is not clogged, it can be applied and workability is good.

When the room temperature viscosity of the epoxy resin composition is 0.5 to 30 Pa · s, hand coating using a roller, a brush, or the like is preferable. When the room temperature viscosity of the epoxy resin composition is 0.5 Pa · s or more, sagging during coating can be suppressed, and when it is 30 Pa · s or less, the brush or roll can be easily immersed in the epoxy resin composition. Since it can be done, workability is improved.

When the room temperature viscosity of the epoxy resin composition is 30,000 to 30,000 Pa · s, it is preferable to apply it by hand coating using a spatula, a bar coater, or the like. In the case of manual coating, when the room temperature viscosity of the epoxy resin composition is 30 Pa · s or more, the resin flow suppressing effect of the epoxy resin composition during the curing process is high, which is preferable. Further, when the room temperature viscosity of the epoxy resin composition is 30,000 Pa · s or less, the adhesion between the epoxy resin composition and the fiber-reinforced composite material precursor is high, and the adhesion between the epoxy resin composition and the fiber-reinforced composite material after curing is high. It is preferable because it has high properties.

When the coating agent for spraying or hand coating made of the epoxy resin composition of the present invention is applied to the fiber-reinforced composite material precursor, the basis weight is preferably 30 to 300 g / m ² . When the basis weight of the epoxy resin composition is 30 g / m ² or more, the surface of the fiber-reinforced composite material can be covered without being visually transparent, and sufficient light resistance can be exhibited. Further, it is preferable that the epoxy resin composition has a texture of 300 g / m ² or less because heat generation during curing of the epoxy resin composition is suppressed when molding together with the fiber-reinforced composite material.

As a method for molding a coating agent for spraying or hand-coating and a fiber-reinforced composite material comprising the epoxy resin composition of the present invention, it is preferable to apply the coating agent to the outermost surface of the fiber-reinforced composite material precursor and then cure both of them. The above-mentioned coating agent composed of the epoxy resin composition of the present invention is applied to the outermost surface of the fiber-reinforced composite material precursor in a predetermined form, and is pressurized and heated to obtain the coating agent and fibers composed of the epoxy resin composition of the present invention. The resin contained in the reinforced composite material precursor can be cured to produce a fiber reinforced composite material. Here, as a method of applying heat and pressure, for example, a press molding method, an autoclave molding method, a bagging molding method, a lapping tape method, an internal pressure molding method and the like are adopted.

Hereinafter, the present invention will be described in detail with reference to Examples. However, the scope of the present invention is not limited to these examples. Unless otherwise specified, various characteristics were measured in an environment with a temperature of 23 ° C. and a relative humidity of 50%.

<Materials used in Examples and Comparative Examples>
(1) Aromatic epoxy resin / bisphenol A type epoxy resin (“jER®” 828, manufactured by Mitsubishi Chemical Corporation) Epoxy equivalent: 175 (g / eq.).

(2) Component [A] Non-aromatic epoxy resin
(3', 4'-Epoxycyclohexane) Methyl 3,4-epoxycyclohexanecarboxylate ("Seroxide®" 2021P, manufactured by Daicel Corporation) Epoxy equivalent: 136 (g / eq.)
1,2-Epoxy-4- (2-oxylanyl) cyclohexane adduct of 2,2-bis (hydroxymethyl) -1-butanol (“EHPE3150”, manufactured by Daicel Corporation)
Tetrakis- (3-cyclohexenylmethyl) epoxidized butanetetracarboxylic acid-modified epsilon-caprolactone (“Epolide®” GT401, manufactured by Daicel Corporation)
-Diglycidyl ether of 2,2-bis (4-hydroxycyclohexyl) propane (YX8000, manufactured by Mitsubishi Chemical Corporation).

(3) Component [B] Pigment, titanium oxide (rutile type) ("Ti-Pure (registered trademark)" R-960, manufactured by The Chemours Company, average particle size 0.5 μm).

(4) Component [C] Non-aromatic thermoplastic resin, polyvinyl formal (“Vinirec (registered trademark)” K, manufactured by JNC Co., Ltd., calculated molecular weight: 40,000 to 54,000 g / mol)
-Polyvinyl formal ("Vinirec (registered trademark)" E, manufactured by JNC Co., Ltd., calculated molecular weight 95,000 to 134,000 g / mol)
-Polyvinyl acetal acetal ("Eslek (registered trademark)" KS-10, manufactured by Sekisui Chemical Co., Ltd., calculated molecular weight 17,000 g / mol)
-Polyvinyl butyral ("Eslek (registered trademark)" BX-L, manufactured by Sekisui Chemical Co., Ltd., calculated molecular weight 18,000 g / mol).

(5) Component [D] Cationic curing agent, dimethyl-p-acetoxyphenylsulfonium hexafluoroantimonate "Sun Aid (registered trademark)" SI-150, manufactured by Sanshin Chemical Industry Co., Ltd.)
-Benzylmethyl p-hydroxyphenylsulfonium hexafluoroantimonate "Sun Aid (registered trademark)" SI-100, manufactured by Sanshin Chemical Industry Co., Ltd.

(6) Component [E] Thixotropy-imparting agent, fumed silica (“AEROSIL®” RY200S, manufactured by Nippon Aerosil Co., Ltd.)
-Alkylammonium clay ("GARAMITE (registered trademark)" 1958, manufactured by BYK Co., Ltd.).

(7) Component [F] Curing aid, 4-hydroxyphenyldimethylsulfonium = methylsulfate ("Sun Aid (registered trademark)" SI-S, manufactured by Sanshin Chemical Industry Co., Ltd.)
4- (Methylthio) phenol ("Sun Aid (registered trademark)" S-ME, manufactured by Sanshin Chemical Industry Co., Ltd.).

(8) Component [G] Rubber / Silicone Rubber Powder (KPM-601, manufactured by Shin-Etsu Chemical Co., Ltd.).

<Method of producing and evaluating epoxy resin composition and fiber-reinforced composite material>
The epoxy resin compositions of each Example and Comparative Example were measured by the following methods.

(1) Preparation of Epoxy Resin Composition The epoxy resin corresponding to the component [A] shown in Tables 1 to 8 (including the aromatic epoxy resin in Example 33 and Comparative Examples 1 and 8), and the component [B]. ], If necessary, the component [E] thixotropy-imparting agent, and the component [G] rubber are put into a three-roll mill and mixed at an arbitrary roll rotation speed to obtain a powder mixing precursor. rice field. The powder mixing precursor and the non-aromatic thermoplastic resin corresponding to the component [C] shown in Tables 1 to 8 were put into a mixer and heated and mixed to dissolve the non-aromatic thermoplastic resin. .. Next, the temperature was lowered to 60 ° C. or lower while continuing kneading, and the component [D] cationic curing agent shown in Tables 1 to 8 and, if necessary, the component [F] curing aid were added and stirred. An epoxy resin composition was obtained.

(2) Measurement of room temperature viscosity of epoxy resin composition The room temperature viscosity of the epoxy resin composition prepared in (1) above is measured by the dynamic viscoelastic device ARES-2KFRTN1-FCO-STD (manufactured by TA Instruments). After setting the epoxy resin composition so that the distance between the upper and lower jigs is 1 mm, use a flat parallel plate with a diameter of 40 mm for the upper and lower measurement jigs, and then twist mode (measurement frequency: 0.5 Hz). The measurement was carried out at a measurement temperature of 23 ° C. for 10 minutes. The average value of the viscosities with a measurement time of 2 to 10 minutes was taken as the room temperature viscosity of the epoxy resin composition.

(3) Pot life measurement of epoxy resin composition The viscosity of the epoxy resin composition prepared in (1) above can be measured by using a dynamic viscoelastic device ARES-2KFRTN1-FCO-STD (manufactured by TA Instruments). Use, use a flat parallel plate with a diameter of 40 mm for the upper and lower measurement jigs, set the epoxy resin composition so that the distance between the upper and lower jigs is 1 mm, and then in twist mode (measurement frequency: 0.5 Hz). It was measured. ^{Viscosity η *} ₂ when held at 65 ° C for 2 minutes ^{, Viscosity η *} _x at 65 ° C for 2 hours is measured, and the thickening ratio at that time is calculated from η ^* _x ÷ η ^* _2. rice field. The time required for the obtained thickening ratio to reach 3 was defined as the pot life.

(4) Measurement of Volatile Amount of Epoxy Resin Composition Weigh the epoxy resin composition prepared in (1) above on a paper pattern (mass: W1) with a target of 3 g (mass: W2), and then weigh the epoxy resin composition. The paper pattern was placed in an oven at 180 ° C. for 1 hour. Then, the epoxy resin composition and the paper pattern were taken out from the oven, left in the desiccator for 30 minutes, and then the combined mass of the epoxy resin and the paper pattern was measured (mass: W3), and the volatile amount in the present invention was calculated by the following formula. Calculated as [%].
{(W2- (W3-W1)} / W2 x 100 [%]
When the calculated volatilization amount was 5% or less, it was regarded as "good", and when it exceeded 5%, it was regarded as "bad".

(5) Measurement of Resin Flow Amount of Epoxy Resin Composition The epoxy resin composition prepared in (1) above was weighed with a target of 3 g on a release film cut into a 15 cm square (mass: W4). The epoxy resin composition is sandwiched between another 15 cm square cut-out film, and then sandwiched between two 10 cm square metal plates (400 g each), and in that state, molded by an autoclave (180 ° C under 6 atm). The temperature was raised to 1.7 ° C./min for 2 hours). After molding, the cured product of the epoxy resin composition protruding from the metal plate of 10 cm square was removed, and the mass of the cured product of the remaining epoxy resin composition was measured (mass: W5). The resin flow amount [%] of the epoxy resin composition in the present invention was calculated by the following calculation formula.
(W4-W5) / W4 × 100 [%]
When the resin flow amount is 5% or less, it is expressed as A, when it exceeds 5%, 10% or less is expressed as B, when it exceeds 10%, when it exceeds 15%, it is expressed as C, and when it exceeds 15%, it is expressed as D.

(6) Adhesion of Epoxy Resin Composition The epoxy resin composition prepared in (1) above is applied to an aluminum plate of an arbitrary size (larger than 10 cm square) so that the epoxy resin composition has a thickness of 80 μm. Then, a 10 cm square stainless steel plate (400 g) that had been released from the mold by spraying Die-free GA-3000 (manufactured by Daikin Industries) was placed on it and held for 30 seconds. After that, the stainless steel plate is lifted, the aluminum plate is leaned against the aluminum plate so that the temperature is 90 ° with respect to the ground, and after 24 hours, the epoxy resin composition is in close contact with the aluminum plate. In the case of the case, the adhesion was regarded as "good", and the case where even a part of the adhesive was peeled off was regarded as "poor".

(7) UV Irradiation Test of Epoxy Resin Composition The epoxy resin composition prepared in (1) above is applied onto a release film so that the epoxy resin composition is 80 μm, and the temperature is raised in an oven at 180 ° C. for 2 hours. A metering weather meter (M6T, manufactured by Suga Testing Machine Co., Ltd.) was used in a state where the cured product of the obtained epoxy resin composition was cured at a temperature of 1.7 ° C./min and the surface of the cured product was half covered with aluminum foil. Since the irradiation wavelength is set to 300 to 400 nm and the integrated illuminance is ^{set to 1.55 kW / m 2} , the cured product of the epoxy resin composition of the present invention is expected to be exposed to sunlight outdoors on a yearly basis. UV light with ^{an integrated intensity of 1000 kJ / m 2} , which is an approximate value of the amount of UV for one month in Japan (summer), was irradiated. After the irradiation, the aluminum foil is peeled off, and the appearance of the place where the aluminum foil is covered and the place where the aluminum foil is not covered can be visually observed. The presence or absence of discoloration of the epoxy resin cured product before and after UV irradiation can be confirmed. Before and after irradiation, the color difference of the cured product of the epoxy resin composition was measured using a multi-light source spectrophotometer (MSC-P, manufactured by Suga Test Instruments Co., Ltd.). The epoxy resin composition was set in a multi-light source spectrophotometer, and the reflectance was measured in the wavelength range of 380 to 780 nm under the conditions of reflection mode, C light source, 2 ° field, and 8 ° incident. Furthermore, the color measurement value (L ^* 1a ^* 1b ^* 1) ^{before UV irradiation in the L *} a ^* b ^* discoloration system was obtained using the program attached to the device. Next, it was determined after UV irradiation was performed (L ^* 2a ^* 2b ^* 2). ^{Furthermore, the color difference ΔE *} ab of the cured product of the epoxy resin composition before and after UV irradiation is set to ΔE ^* ab = [(L ^* 1-L ^* 2) ² + (a ^* 1-a ^* 2) ² + (b ^*). 1-b ^* 2) ² ] ^Obtained by 1/2. When the obtained ΔE ^* ab was 4 or less, the UV resistance was defined as “good”, and when ΔE ^* ab exceeded 4, the UV resistance was defined as “poor”.

(8) Amount of prepreg resin mixed in the epoxy resin composition during the molding process The epoxy resin composition prepared in (1) above is simulated as a continuous fiber prepreg (T800S / 3900-2B (manufactured by Toray Co., Ltd.)). Epoxy resin composition was applied to the outermost surface of a stack of eight sheets so as to be isotropic (laminated structure: [+ 45 ° / 0 ° / −45 ° / 90 °] _{s) so as to have a thickness of 80 μm.} IR measurement (FT / IR-4000 Japan) of the cured product side of the epoxy resin composition of the composite material molded in an autoclave under the conditions of 6 atm, 180 ° C. for 2 hours, and temperature rise of 1.7 ° C./min. Spectral Co., Ltd., Prism: Diamond, Measurement wavelength: 400 to 4000 cm ^-1 , Accumulation number: 16 times), ^{standardized using the peak of 1715 cm -1} indicating ester, and the resin cured used in the prepreg. ^{By evaluating the peak value of 1592 cm -1} , which indicates the benzene ring caused by the substance, the resin used for the prepreg is mixed with the coating agent composed of the epoxy resin composition during the molding process, and the surface of the fiber-reinforced composite material is mixed. It is possible to evaluate the amount of exposure to. ^{When the peak value of 1592 cm -1} , which indicates the benzene ring caused by the cured resin used in the prepreg, was 0.6 or less, it was judged that the UV resistance of the surface of the fiber-reinforced composite material was good. Further, in Examples 35 to 56 and Comparative Examples 9 to 11, IR measurement was carried out by the ATR method in the same manner as described above, and ^{standardization using a peak of 1715 cm-1} indicating an ester was not performed, and the prepreg was used. The value of the peak of ^{1592 cm -1} showing the benzene ring caused by the cured resin product was evaluated. ^{In this case, if the peak value of 1592 cm -1} , which indicates the benzene ring caused by the cured resin used in the prepreg, is 1.0 or less, it is determined that the UV resistance of the surface of the fiber-reinforced composite material is good.

(9) Method of applying the epoxy resin composition to the surface of the prepreg When the epoxy resin composition is applied by spraying, the epoxy resin composition is applied to the surface of the prepreg using a spray gun W-2001-2 (manufactured by Anest Iwata Co., Ltd.). The object was sprayed and applied.

When the epoxy resin composition is hand-painted with a brush, the epoxy resin composition is stored in a container, the brush is dipped in the container, and then the epoxy resin composition is directly applied to the target.

When the epoxy resin composition was manually applied using a bar coater, the epoxy resin composition was placed on the surface of the object to be coated, spread with a bar coater, and applied to the object.

(10) Method for measuring the exothermic peak temperature of the epoxy resin composition Using a differential scanning calorimeter (DSC Q2500: manufactured by TA Instruments), the epoxy resin is heated at a heating rate of 5 ° C./min in a nitrogen atmosphere. The exothermic curve of the composition was obtained. In the obtained heat generation curve, the temperature at the peak of the heat generation peak having a heat generation amount of 100 mW / g or more was calculated as the heat generation peak temperature. When there are two or more exothermic peaks having a calorific value of 100 mW / g or more, the temperature of the apex of the peak on the low temperature side is calculated as the exothermic peak temperature of the DSC in the present invention. Regarding the evaluation of quick curing, in Tables 1 to 4, the exothermic peak temperature of 100 ° C. or lower is represented by A, 100 ° C. or lower, 120 ° C. or lower is represented by B, 120 ° C. or lower is represented by C, and 140 ° C. or lower is represented by D. bottom.

(11) Bending test of the cured epoxy resin composition After defoaming the uncured epoxy resin composition in a vacuum, a spacer made of "Teflon (registered trademark)" having a thickness of 2 mm is used so that the thickness becomes 2 mm. In the set mold, it was cured at a temperature of 180 ° C. for 2 hours. The obtained cured epoxy resin having a thickness of 2 mm was cut into 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 (manufactured by Instron), three-point bending with a span of 32 mm was performed according to JIS-K7171 (1994), and the elastic modulus and bending strain (elongation) were measured. The number of measurements was N = 6, and the average value was calculated.

<Examples 1 to 32 and Comparative Example 1>
In Examples 1-32, as the component [A], only (3', 4'-epoxycyclohexane) methyl3,4-epoxycyclohexanecarboxylate or 2,2-bis (hydroxymethyl) -1-butanol is used. Epoxy resin composition by combination of 1,2-epoxy-4- (2-oxylanyl) cyclohexane adduct and non-aromatic epoxy resin with epoxidized butanetetracarboxylic acid tetrakis- (3-cyclohexenylmethyl) modified epsilon-caprolactone. When a product was used, no discoloration was observed even after curing in the UV resistance test, and good results were obtained. On the other hand, in Comparative Example 1 containing only the aromatic epoxy resin without containing the component [A] non-aromatic epoxy resin, it was judged to be defective in the UV resistance test, and it was shown that the UV resistance was low.

<Examples 1 and 2>
In Examples 1 and 2, the type of the component [D] was changed and compared. As a result, when benzylmethyl p-hydroxyphenylsulfonium hexafluoroantimonate was used as the cationic curing agent, and when iodonium salt was used as the cationic curing agent. It has been shown to be faster-curing than, volatile, resin-flowing, and tending to reduce the amount of prepreg resin mixed into the coating of the epoxy resin composition during the molding process, while pots. It has been shown that life is reduced.

<Examples 2 to 6, 21 to 23, 26 to 28, 34, Comparative Examples 4 to 5>
In Examples 2 to 3 of the spraying method, the type of the component [C] was changed and compared. As a result, it was shown that the effect of suppressing the resin flow amount was higher when the polyvinyl acetal compared with polyvinyl formal was used. Was done. Similarly, in Examples 4 to 6 of the spraying method, the addition amount of polyvinyl acetal was changed, and it was shown that the effect of suppressing the resin flow amount was improved as the amount was increased.

On the other hand, in Comparative Example 4, when the component [C] is not included, the amount of resin flow is large, and the amount of resin of the prepreg mixed in the coating agent composed of the epoxy resin composition of the present invention during the molding process becomes excessive. It was judged to be defective.

Further, in Examples 21 to 22 of hand coating using a brush as the coating method and Examples 23 and 26 to 28 of hand coating using a bar coater as the coating method, the amount of polyvinyl formal of the component [C] was changed. In these cases as well, it was shown that the effect of suppressing the resin flow amount is improved as the amount of the component [C] is increased.

On the other hand, in Example 28, when the amount of polyvinyl formal of the component [C] was 75 parts by mass, it was shown that the adhesion was good, while the amount of polyvinyl formal was changed as in Comparative Example 5. When it was 80 parts by mass, the viscosity at room temperature was high, and it was judged that the adhesion was poor.

Further, in Example 34, as a component [C], Vinilek E (calculated molecular weight 95,000 to 134,000 g / mol) having a calculated molecular weight higher than that of Vinilek K (calculated molecular weight of 40,000 to 54,000 g / mol) or Eslek KS-10 (calculated molecular weight of 17,000 g / mol). When mol) was used, the resin flow suppressing effect was high, and while the effect of suppressing the amount of resin of the prepreg mixed in the cured resin during the molding process was shown, it was judged that the room temperature viscosity was excessive and the adhesion was poor. Was done.

<Examples 23 to 25, 33, Comparative Example 8>
In Example 23, 100 parts by mass of (3', 4'-epoxycyclohexane) methyl 3,4-epoxycyclohexane carboxylate was used as the component [A], while 70 parts by mass of (3', 4'-epoxycyclohexane) was used. In Example 24, 30 mass of 1,2-epoxy-4- (2-oxylanyl) cyclohexane adduct of 2,2-bis (hydroxymethyl) -1-butanol was added to methyl 3,4-epoxycyclohexanecarboxylate. In Example 25, 30 parts by mass of epoxidized butane tetracarboxylic acid tetrakis- (3-cyclohexenylmethyl) -modified epsilon-caprolactone was added. As a result, the adhesion of the epoxy resin compositions in Examples 23 to 25 was good, and the UV resistance was also good. Therefore, it was shown that, in the case of a non-aromatic epoxy resin, an epoxy resin composition having good physical properties can be obtained both when one type of epoxy resin is used and when two or more types of epoxy resins are used. rice field.

Further, in Example 33, 90 parts by mass of the non-aromatic epoxy resin and 10 parts by mass of the aromatic epoxy resin were used in combination, and the UV resistance was evaluated. As a result, it was determined to be good. Therefore, it was shown that the UV resistance is good in the case of the epoxy resin composition containing 10% by mass of the aromatic epoxy resin among the epoxy resins.

On the other hand, in Comparative Example 8, 80 parts by mass of the non-aromatic epoxy resin and 20 parts by mass of the aromatic epoxy resin were used in combination, and as a result of evaluating the UV resistance, it was determined to be defective. Therefore, it was shown that the UV resistance of the epoxy resin composition containing 20% by mass of the aromatic epoxy resin among the epoxy resins is poor.

<Examples 1, 2, 7 to 10, Comparative Examples 6, 7>
In Example 7, the amount of iodonium salt, which is a component [D] cationic curing agent, was increased as compared with Example 1. Although the fast-curing property of the epoxy resin composition of Example 7 was increased as compared with Example 1, the pot life was decreased, but the volatile amount and the resin flow amount were obtained from the epoxy resin composition of the present invention during the molding process. It was shown that the effect of suppressing the amount of resin of the prepreg mixed in the coating agent is high.

Similarly, in Example 8, the amount of benzylmethyl p-hydroxyphenylsulfonium hexafluoroantimonate, which is a cationic curing agent for the component [D], was increased as compared with Example 2. The fast-curing property of the epoxy resin composition of Example 8 was increased as compared with Example 2, while the pot life was decreased, but it consisted of the volatile amount, the resin flow amount, and the epoxy resin composition of the present invention during the molding process. It was shown that the effect of suppressing the amount of resin of the prepreg mixed in the coating agent is high.

In Examples 9 to 10, two types of dimethyl-p-acetoxyphenylsulfonium hexafluoroantimonate and benzylmethyl p-hydroxyphenylsulfonium hexafluoroantimonate, which are cationic curing agents for the component [D], were used in combination as curing agents. In Example 9, the fast curing property was decreased as compared with Example 8, while the pot life was increased. In Example 10, the amount of methyl-p-acetoxyphenylsulfonium hexafluoroantimonate is increased from that of Example 9. In Example 10, the fast curing property was improved as compared with Example 9, and the pot life was lowered. Therefore, it was shown that the balance between the quick-curing property and the pot life of the epoxy resin composition can be controlled by the addition ratio of the component [D] cationic curing agent and the mixing ratio when two kinds are added.

In Comparative Example 6, 0.05 part of dimethyl-p-acetoxyphenylsulfonium hexafluoroantimonate, which is a component [D] cationic curing agent, was added. In Comparative Example 6, the quick-curing property was low, and the amount of volatilization and the amount of prepreg resin mixed in the epoxy resin composition during the molding process were determined to be defective.

On the other hand, in Comparative Example 7, 15 parts by mass of benzylmethyl p-hydroxyphenylsulfonium hexafluoroantimonate was added. The fast-curing property was high, but the pot life was significantly reduced. Further, it was determined that the evaluation of the amount of the prepreg resin mixed in the coating agent composed of the epoxy resin composition during the molding process was poor, but in Comparative Example 7, after curing after UV irradiation of ^{1000 kJ / m 2.} Since it was determined to be defective by the UV resistance test of the epoxy resin composition, it was shown that the UV resistance was low.

<Examples 11 to 12, Examples 29 to 30, Comparative Examples 2 and 3>
In Examples 11 to 12, as a result of changing the amount of titanium oxide of the component [B] and making a comparison, the quick-curing property of Example 12 having a large amount of titanium oxide was lower than that of Example 11. However, it was shown that the pot life was improved and the reactivity of the epoxy resin composition could be controlled by the amount of titanium oxide. Further, it was shown that Example 12 having a large amount of titanium oxide has a higher effect of suppressing the amount of prepreg resin mixed in the epoxy resin composition during the molding process than that of Example 11.

In Examples 29 to 30, the amounts of titanium oxide of the component [B] were set to 15 parts by mass and 75 parts by mass, respectively. It was shown that the fast curability of Example 30 was lower than that of Example 29, and the effect of suppressing and improving the amount of volatilization was high. In addition, it was determined that the UV resistance of both and the amount of prepreg resin mixed in the epoxy resin composition during the molding process were good.

On the other hand, when the titanium oxide of the component [B] was 10 parts by mass as in Comparative Example 2, the amount of resin of the prepreg mixed in the epoxy resin composition during the molding process was large, and it was determined to be defective.

Further, when 100 parts by mass of titanium oxide of the component [B] (II) was added as in Comparative Example 3, the quick-curing property was poor, and the amount of volatilization after 1 hour at 180 ° C. was determined to be poor.

<Examples 8, 13 to 15, 23, 31>
In Examples 13 to 15 in which the coating method was a spray, the curing aid of the component [F] was applied. In Example 13, 0.2 parts by mass of the curing aid 4-hydroxyphenyldimethylsulfonium = methylsulfate was applied as the component [F], and as a result, the pot life was improved as compared with Example 8. Further, in Example 15, as a result of increasing the amount of 4-hydroxyphenyldimethylsulfonium = methylsulfate to 1.0 part, further improvement in pot life was observed as compared with Example 13. Similarly, in Example 14, the type of curing aid for the component [F] was changed to 4- (methylthio) phenol, and 0.2 parts were applied. As a result, the pot life was improved as compared with Example 8. .. Further, it was determined that Examples 13 to 15 had good volatility, UV resistance, and the amount of resin of the prepreg mixed in the coating agent composed of the epoxy resin composition during the molding process.

Further, as a result of applying 0.2 parts by mass of 4-hydroxyphenyldimethylsulfonium = methylsulfate as a component [F] in Example 31 in which the coating method is hand coating using a bar coater, the coating method is also the bar coater. An improvement in pot life was observed as compared with Example 23, which was hand-painted using. Therefore, it was shown that the pot life improving effect can be obtained by applying the component [F] to the epoxy resin composition regardless of the coating method.

<Examples 8, 16-18, 23, 32>
In Examples 16 to 18 in which the coating method is a spray, the component [E] thixotropy-imparting agent is applied. In Examples 16 to 17, four parts each of fumed silica and alkylammonium clay are applied to Example 8 in which the coating method is spray, and the amount of resin flow is not impaired in quick curing and UV resistance. In addition, the effect of suppressing the amount of prepreg resin mixed in the epoxy resin composition during the molding process was shown. Further, in Example 18, both fumed silica and alkylammonium clay are applied to Example 8 in four parts each, and the amount of resin flow and the epoxy resin composition in the molding process are further compared with those of Examples 16 to 17. It was shown that the effect of suppressing the amount of resin of the prepreg mixed in the substance is high.

Further, when both fumed silica and alkylammonium clay are applied to the component [E] in Example 32 of hand coating using a bar coater as the coating method, the coating method is also hand coating using the bar coater. Example 23 It was shown that the effect of suppressing the amount of resin flow and the amount of prepreg resin mixed in the epoxy resin composition during the molding process was high.

Therefore, not limited to the coating method, by applying the component [E] to the epoxy resin composition, it is possible to obtain the effect of suppressing the resin flow amount and the effect of improving the resin amount of the prepreg mixed in the epoxy resin composition during the molding process. Was shown.

<Examples 8, 19 to 20>
In Examples 19 to 20 in which the coating method is a spray, both the component [E] thixotropy-imparting agent and the component [F] curing aid are applied, and the same as in Example 8 in which the coating method is a spray. In comparison, it was shown that the resin flow amount and the resin amount of the prepreg mixed in the epoxy resin composition during the molding process were suppressed, and the pot life was excellent. Therefore, it was shown that a synergistic effect can be obtained by using the components [E] and [F] at the same time.

Further, when both the component [E] thixotropy-imparting agent and the component [F] curing aid are applied in Example 32 of hand coating using a bar coater as the application method, the application method also uses the bar coater. It was shown that there was an effect of suppressing the amount of the resin flow compared to Example 23, which was hand-painted, and the amount of the prepreg resin mixed in the epoxy resin composition during the molding process, and the pot life was further excellent.

Therefore, not limited to the coating method, by applying both the constituent element [E] and the constituent element [F] to the epoxy resin composition, the effect of suppressing the resin flow amount and the prepreg mixed in the epoxy resin composition during the molding process can be obtained. It was shown that the effect of improving the amount of resin can be obtained.

<Examples 8, 35 to 45, Comparative Examples 9 to 10>
In Examples 35 to 37, diglycidyl ether of 2,2-bis (4-hydroxycyclohexyl) propane was used as the non-aromatic epoxy resin of the component [A], and the non-aromatic thermoplastic resin of the component [C] was used. One type each of polyvinyl formal, polyvinyl acetal acetal, and polyvinyl butyral was used. In the order of Examples 35, 36, and 37, a decrease in elastic modulus and an improvement in bending strain were observed in the cured product of the epoxy resin composition. Further, when Example 35 and Example 8 are compared, the exothermic peak temperature of Example 35 is low, but the pot life is high, and the reactivity can be controlled by changing the type of the component [A]. It has been shown. Therefore, the reactivity can be controlled by changing the type of the component [A], and the quick-curing property and the pot life, that is, the effect of suppressing the amount of resin flow in the molding process, the effect of suppressing the amount of resin of the prepreg mixed in the cured resin, and the process. It was shown that the balance with passability can be adjusted.

In Examples 38 to 39, silicone rubber powder of the component [G] rubber was used. By increasing the content of the component [G], the effect of lowering the elastic modulus of the cured product of the epoxy resin composition, improving the bending strain, and suppressing the amount of resin flow was shown. On the other hand, when the component [G] is too small as in Comparative Example 9, the effect of suppressing the amount of resin flow is not sufficiently exhibited, and the amount of resin of the prepreg mixed with the cured resin during the molding process becomes excessive, which is defective. Was determined. Further, when the component [G] was excessive as in Comparative Example 10, the nozzle was clogged with the epoxy resin composition when spraying, and the coating could not be performed.

In Examples 40 to 41, the non-aromatic epoxy resin of the component [A] is composed of (3', 4'-epoxycyclohexane) methyl 3,4-epoxycyclohexanecarboxylate and 2,2-bis (4-hydroxycyclohexyl) propane. Two kinds of diglycidyl ethers of the above were used. Comparing Examples 35, 40 to 41, the higher the content of (3', 4'-epoxycyclohexane) methyl3,4-epoxycyclohexanecarboxylate, the lower the exothermic peak temperature, the lower the resin flow amount and the molding process. It was shown that the amount of resin in the prepreg mixed in the cured resin product was suppressed. Example 8 in which only one type of (3', 4'-epoxycyclohexane) methyl3,4-epoxycyclohexanecarboxylate was used as the component [A] was excellent in quick-curing property and was 2,2-bis (4-hydroxycyclohexyl). ) In Example 35 using only one type of diglycidyl ether of propane, it was shown that the pot life was excellent, and when two types of the above were used as in Examples 40 to 41, excellent quick curing and excellent performance were achieved. It is possible to achieve both pot life. Therefore, the reactivity of the epoxy resin composition can be controlled by using two types of the non-aromatic epoxy resin of the component [A], and the epoxy resin composition is mixed with the quick-curing property, the pot life, that is, the amount of resin flow during the molding process and the cured resin product. It was shown that the balance between the effect of suppressing the amount of resin in the prepreg and the process passability can be adjusted. Here, when Examples 8 and 35 are compared, it is more than Example 8 in which (3', 4'-epoxycyclohexane) methyl 3,4-epoxycyclohexanecarboxylate is used for the non-aromatic epoxy resin of the component [A]. It was shown that Example 35 using diglycidyl ether of 2,2-bis (4-hydroxycyclohexyl) propane had a higher bending strain of the epoxy resin cured product, and when Examples 40 to 41 were compared, the constituent elements [ It was shown that the higher the proportion of diglycidyl ether of 2,2-bis (4-hydroxycyclohexyl) propane used as the non-aromatic epoxy resin of A], the higher the bending strain of the epoxy resin cured product.

In Example 42, (3', 4'-epoxycyclohexane) methyl 3,4-epoxycyclohexanecarboxylate was added to the non-aromatic epoxy resin of the component [A], and in Example 43, (3', 4'-epoxycyclohexane). Using methyl 3,4-epoxycyclohexanecarboxylate and diglycidyl ether of 2,2-bis (4-hydroxycyclohexyl) propane, both are 4-hydroxyphenyldimethylsulfonium = methylsul as a curing aid for component [F]. Fate was used. In Example 42, the exothermic peak temperature was improved in Examples 42 and 43 as compared with Example 35 and Example 43, respectively, and the reactivity of the epoxy resin composition was controlled by the inclusion of the component [F]. It was shown to be possible.

In Example 44, the non-aromatic epoxy resin of the component [A] was coated with (3', 4'-epoxycyclohexane) methyl 3,4-epoxycyclohexanecarboxylate, and in Example 45, (3', 4'-epoxycyclohexane). Using methyl 3,4-epoxycyclohexanecarboxylate and diglycidyl ether of 2,2-bis (4-hydroxycyclohexyl) propane, both are constituents [E] fumed silica, a thixotropy-imparting agent, constituents [F]. A curing aid 4-hydroxyphenyldimethylsulfonium = methylsulfate and silicone rubber powder of component [G] rubber were used. Comparing Example 44 with Example 35 and Example 45 with Example 41, it is shown that the reactivity of the epoxy resin composition can be controlled by the inclusion of the component [F] in Examples 44 and 45, respectively. Was done. Further, as compared with Example 42 in Example 44 and Example 43 in Example 43, in Examples 44 and 45, the amount of resin flow is suppressed by the inclusion of the component [E] and the component [G]. The amount of prepreg resin mixed in the cured resin during the molding process was also suppressed. Comparing Example 44 with Example 35 and Example 45 with Example 41, Examples 44 and 45 show the effect of further improving the pot life of the epoxy resin composition by containing the component [F], respectively. rice field.

<Examples 23, 46 to 56, Comparative Example 11>
In Examples 46 to 48, diglycidyl ether of 2,2-bis (4-hydroxycyclohexyl) propane was used as the non-aromatic epoxy resin of the component [A], and the non-aromatic thermoplastic resin of the component [C] was used. One type each of polyvinyl formal, polyvinyl acetal acetal, and polyvinyl butyral was used. In the order of Examples 46, 47, and 48, the room temperature viscosity was improved, the elastic modulus of the cured product of the epoxy resin composition was lowered, and the bending strain was improved. Further, when Example 46 and Example 23 were compared, the exothermic peak temperature was lower in Example 46, but showed a high pot life. Therefore, the reactivity can be controlled by changing the type of the component [A], and the quick-curing property and the pot life, that is, the effect of suppressing the amount of resin flow in the molding process, the effect of suppressing the amount of resin of the prepreg mixed in the cured resin, and the process. It was shown that the balance with passability can be adjusted.

In Examples 49 to 50, silicone rubber powder of the component [G] rubber was used. By increasing the content of the component [G], the room temperature viscosity was improved, the elastic modulus of the cured product of the epoxy resin composition was lowered, the bending strain was improved, and the resin flow amount was suppressed. On the other hand, when the component [G] is excessive as in Comparative Example 11, the room temperature viscosity is also excessive, and it is determined that the stickability is poor.

In Examples 51 to 52, the non-aromatic epoxy resin of the component [A] is composed of (3', 4'-epoxycyclohexane) methyl 3,4-epoxycyclohexanecarboxylate and 2,2-bis (4-hydroxycyclohexyl) propane. Two kinds of diglycidyl ethers of the above were used. Comparing Examples 46, 51 to 52, the higher the content of (3', 4'-epoxycyclohexane) methyl 3,4-epoxycyclohexane carboxylate, the lower the exothermic peak temperature, the lower the resin flow amount and the molding process. It was shown that the amount of resin in the prepreg mixed in the cured resin product was suppressed. Example 23 in which only one type of (3', 4'-epoxycyclohexane) methyl3,4-epoxycyclohexanecarboxylate was used as the component [A] was excellent in quick-curing property and was 2,2-bis (4-hydroxycyclohexyl). ) Example 46 using only one type of diglycidyl ether of propane has been shown to be excellent in pot life, and when two types of the above are used as in Examples 51 to 52, excellent quick curing and excellent properties are achieved. It is possible to achieve both pot life. Therefore, the reactivity of the epoxy resin composition can be controlled by using two types of the non-aromatic epoxy resin of the component [A], and the epoxy resin composition is mixed with the quick-curing property, the pot life, that is, the amount of resin flow during the molding process and the cured resin product. It was shown that the balance between the effect of suppressing the amount of resin in the prepreg and the process passability can be adjusted. Here, when Examples 23 and 46 are compared, it is more than that of Example 23 in which (3', 4'-epoxycyclohexane) methyl 3,4-epoxycyclohexanecarboxylate is used for the non-aromatic epoxy resin of the component [A]. It was shown that Example 46 using diglycidyl ether of 2,2-bis (4-hydroxycyclohexyl) propane had a higher bending strain of the epoxy resin cured product, and when Examples 51 to 52 were compared, the constituent elements [ It was shown that the higher the proportion of diglycidyl ether of 2,2-bis (4-hydroxycyclohexyl) propane used as the non-aromatic epoxy resin of A], the higher the bending strain of the epoxy resin cured product.

In Example 53, the non-aromatic epoxy resin of the component [A] was coated with (3', 4'-epoxycyclohexane) methyl 3,4-epoxycyclohexanecarboxylate, and in Example 54, (3', 4'-epoxycyclohexane). Using methyl 3,4-epoxycyclohexanecarboxylate and diglycidyl ether of 2,2-bis (4-hydroxycyclohexyl) propane, both are 4-hydroxyphenyldimethylsulfonium = methylsul as a curing aid for component [F]. Fate was used. Compared with Example 46 and Example 52 in Example 53, in Examples 53 and 54, the exothermic peak temperature was improved, respectively, and the reactivity of the epoxy resin composition was controlled by the inclusion of the component [F]. It was shown to be possible.

In Example 55, the non-aromatic epoxy resin of the component [A] was coated with (3', 4'-epoxycyclohexane) methyl 3,4-epoxycyclohexanecarboxylate, and in Example 56, (3', 4'-epoxycyclohexane). Using methyl 3,4-epoxycyclohexanecarboxylate and diglycidyl ether of 2,2-bis (4-hydroxycyclohexyl) propane, both are constituents [E] fumed silica, a thixotropy-imparting agent, constituents [F]. A curing aid 4-hydroxyphenyldimethylsulfonium = methylsulfate and silicone rubber powder of component [G] rubber were used. Comparing Example 55 with Example 46 and Example 56 with Example 52, Examples 55 and 56 showed the effect of further improving the pot life of the epoxy resin composition by containing the component [F], respectively. rice field.

Claims (14)

A coating agent for spraying or hand-coating, which comprises an epoxy resin composition containing at least the components [A] to [D], and 90 to 100 parts by mass of [A] with respect to 100 parts by mass of the total epoxy resin. A coating agent containing 15 to 75 parts by mass of [B], 0.05 to 75 parts by mass of [C], and 0.1 to 10 parts by mass of [D].
[A] Non-aromatic epoxy resin [B] Pigment with average particle size of 0.1 to 10 μm [C] Non-aromatic thermoplastic resin [D] Cationic or anionic curing agent The coating agent according to claim 1, wherein the epoxy resin composition further comprises a component [E] thixotropy-imparting agent. The coating agent according to claim 1 or 2, wherein the non-aromatic compound is contained in an amount of 90% by mass or more based on the entire epoxy resin composition. The coating agent according to any one of claims 1 to 3, wherein the epoxy resin composition further comprises a component [F] curing aid. The coating agent according to any one of claims 1 to 4, wherein the epoxy resin composition further comprises a component [G] rubber. The coating agent according to any one of claims 1 to 5, wherein the epoxy resin composition contains at least two kinds of component [A] non-aromatic epoxy. Component [A] The coating agent according to any one of claims 1 to 6, wherein the non-aromatic epoxy resin is an alicyclic epoxy resin. The component [C] according to any one of claims 1 to 7, wherein the non-aromatic thermoplastic resin is at least one selected from the group consisting of polyvinyl alcohol, polyvinyl formal, polyvinyl butyral, polyvinyl acetal acetal and polyvinyl acetate. Coating agent. The coating agent according to any one of claims 1 to 8, wherein the DSC heat generation peak temperature is 80 to 120 ° C. The coating agent according to any one of claims 1 to 9, wherein the volatilization amount is 10% or less. The coating agent according to any one of claims 1 to 10, wherein the cured product of the epoxy resin composition is irradiated with ultraviolet rays having a wavelength of 300 to 400 nm at 1000 kJ / m ² and the value of the formula difference ΔE ^{* ab is 4 or less.} An intermediate base material obtained by applying the coating agent according to any one of claims 1 to 11 to a metal surface. An intermediate base material obtained by applying the coating agent according to any one of claims 1 to 11 to the surface of a fiber-reinforced composite material precursor. An intermediate base material obtained by applying the coating agent according to any one of claims 1 to 11 to the surface of a fiber-reinforced composite material.