Curable resin composition, electrical and electronic component, and method for manufacturing electrical and electronic component

Abstract

Provided is a curable resin composition which can be injection molded, is excellent in productivity, can obtain a cured product which is excellent in adhesion to a substrate, particularly a difficult-to-bond resin substrate, and has a good appearance. A curable resin composition comprising (A) a curable resin, (B) an ethylenically unsaturated monomer, (C) an inorganic filler, (D) a thermal polymerization initiator, (E) a glass fiber, and (F) a low shrinkage agent, wherein (A) the curable resin contains at least a vinyl ester resin, (B) the ethylenically unsaturated monomer contains at least an aromatic vinyl compound, the aromatic vinyl compound contains at least an aromatic divinyl compound, and the proportion of the total amount of vinyl groups possessed by the aromatic vinyl compound to the total amount of ethylenically unsaturated groups contained in (A) the curable resin and (B) the ethylenically unsaturated monomer is 60 to 95 mol%.

Description

TECHNICAL FIELD

[0001] The present application relates to a curable resin composition, an electrical and electronic component, and a manufacturing method of an electrical and electronic component. BACKGROUND

[0002] For electronic devices such as an electronic control unit mounted on a motor, a coil, an automobile, and the like, in order to protect a wiring board and electronic components mounted on the wiring board and the like, it is required to fix the constituent components so as to prevent breakage of the components due to vibration, or to prevent intrusion of water and corrosive gases and the like. At this time, a configuration is generally used in which the entire electronic components are sealed by a material called a sealing material, and fixed.

[0003] For example, a sealing epoxy resin composition used for forming a sealing material that seals a space between a wiring board and electronic components is disclosed in Patent Literature 1. An unsaturated polyester resin composition for molding of electrical / electronic components containing a novolak vinyl ester resin 7 to 15% by weight, a di-unsaturated polyester resin 2 to 5% by weight, and magnesium oxide 65 to 80% by weight is disclosed in Patent Literature 2.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Application Laid-Open No. 2014-148586

[0007] Patent Literature 2: Japanese Patent Application Laid-Open No. 2004-27019 SUMMARY

[0008] PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] However, since the raw material unit price of the epoxy resin is relatively expensive among resins, there is a problem that it is not easy to use for large products. Further, since the molding temperature of the epoxy resin composition is a high temperature of 170 to 180°C and the curing time is long, there is room for improvement in terms of reliability, productivity, and cost of electronic devices. From the viewpoint of adhesion to a substrate, the resin composition disclosed in Patent Literature 2 has room for further improvement.

[0010] The present application has been made in order to solve the above problems, and an object thereof is to provide a curable resin composition that can be injection molded and is excellent in productivity, can obtain excellent adhesion to a substrate, particularly a difficult-to-bond resin substrate, and has a cured product with a good appearance. Further, an object of the present application is to provide an electrical and electronic component having the cured product as a sealing material, and a manufacturing method thereof.

[0011] MEANS FOR SOLVING THE PROBLEMS

[0012] The present application comprises the following solutions. [1]

[0014] A curable resin composition comprising

[0015] (A) a curable resin,

[0016] (B) an ethylenically unsaturated monomer,

[0017] (C) an inorganic filler,

[0018] (D) a thermal polymerization initiator,

[0019] (E) glass fibers, and

[0020] (F) a low shrinkage agent,

[0021] the above-mentioned (A) curable resin contains at least a vinyl ester resin,

[0022] the above-mentioned (B) ethylenically unsaturated monomer contains at least an aromatic vinyl compound,

[0023] the above-mentioned aromatic vinyl compound contains at least an aromatic divinyl compound,

[0024] the total amount of the vinyl groups possessed by the above-mentioned aromatic vinyl compound is 60 to 95 mol% relative to the total amount of the ethylenically unsaturated groups contained in the above-mentioned (A) curable resin and the above-mentioned (B) ethylenically unsaturated monomer. [2]

[0026] The curable resin composition according to [1], the proportion of the aromatic divinyl compound contained in the above-mentioned (B) ethylenically unsaturated monomer is 5 to 50 mol%. [3]

[0028] The curable resin composition according to [1] or [2], the proportion of the aromatic vinyl compound contained in the above-mentioned (B) ethylenically unsaturated monomer is 70 mol% or more. [4]

[0030] The curable resin composition according to any one of [1] to [3], the above-mentioned aromatic divinyl compound is divinylbenzene. [5]

[0032] The curable resin composition according to any one of [1] to [4], the above-mentioned aromatic vinyl compound is composed of divinylbenzene and at least one selected from ethylvinylbenzene and styrene. [6]

[0034] The curable resin composition according to any one of [1] to [5], wherein the curable resin composition contains, relative to 100 parts by mass of the total of (A) the curable resin and (B) the ethylenically unsaturated monomer,

[0035] (A) the curable resin 5 to 95 parts by mass,

[0036] (B) the ethylenically unsaturated monomer 5 to 95 parts by mass,

[0037] (C) the inorganic filler 200 to 700 parts by mass,

[0038] (D) the thermal polymerization initiator 0.1 to 20 parts by mass,

[0039] (E) the glass fiber 10 to 300 parts by mass, and

[0040] (F) the low shrinkage agent 10 to 80 parts by mass. [7]

[0042] The curable resin composition according to any one of [1] to [6], further comprising (G) an acidic surfactant. [8]

[0044] An electrical and electronic component provided with a cured product of the curable resin composition according to any one of [1] to [7]. [9]

[0046] A method for producing an electrical and electronic component, including a step of injection molding the curable resin composition according to any one of [1] to [7] to enclose a constituent member of an electrical and electronic component, and a step of heat-curing the curable resin composition.

[0047] Effects of the Invention

[0048] According to the present application, it is possible to provide a curable resin composition which can be injection molded and is excellent in productivity, which can obtain a cured product excellent in adhesion to a substrate, particularly a difficult-to-bond resin substrate, and which has a good appearance. Further, it is possible to provide a cured product obtained by curing the curable resin composition, an electrical and electronic component provided with the cured product, and a method for producing the same. DETAILED DESCRIPTION

[0049] Hereinafter, embodiments of the present application will be described in detail. However, the present application is not limited to the embodiments shown below.

[0050] In the present specification, "(meth)acrylic acid" means methacrylic acid or acrylic acid, and "(meth)acrylate" means acrylate or methacrylate.

[0051] The "ethylenic unsaturated bond" refers to a double bond formed between carbon atoms other than carbon atoms forming an aromatic ring. The "ethylenic unsaturated group" refers to a group having an ethylenic unsaturated bond. The "ethylenic unsaturated monomer" refers to a monomer having an ethylenic unsaturated bond. The "vinyl group" represents CH2=CH-, and does not include 1-alkenyl groups such as an allyl group. The "vinyl group" in the vinyl ester resin is not limited to this.

[0052] 1. Curable resin composition

[0053] The curable resin composition of one embodiment contains (A) a curable resin, (B) an ethylenic unsaturated monomer, (C) an inorganic filler, (D) a thermal polymerization initiator, (E) glass fibers, and (F) a low shrinkage agent.

[0054] The curable resin composition can further contain (G) an acidic surfactant as needed.

[0055] [(A) Curable resin]

[0056] (A) The curable resin is not particularly limited as long as it is a curable resin generally used in a sealing material application. It is preferable to be, for example, a resin having a functional group capable of forming a crosslinked structure when heat-cured as a curable resin composition. As specific examples of the (A) curable resin, (A-1) a vinyl ester resin, (A-2) an unsaturated polyester resin, (A-3) a urethane (meth) acrylate resin, (A-4) a diallyl phthalate resin, (A-5) an epoxy resin, and the like can be given. From the viewpoints of material cost and moldability, the (A) curable resin contains at least the (A-1) vinyl ester resin. The (A) curable resin can be used alone or in combination with two or more kinds.

[0057] The content of the (A-1) vinyl ester resin in the (A) curable resin is preferably 75 mass% or more, more preferably 80 mass% or more, and further preferably 90 mass% or more. If the content of the (A-1) vinyl ester resin is 75 mass% or more, the material cost of the curable resin composition can be suppressed, a cured product having more excellent moldability and adhesiveness can be obtained. The upper limit of the content of the (A-1) vinyl ester resin in the (A) curable resin is not particularly limited. For example, it can be 100 mass%, 97 mass%, or 95 mass%.

[0058] The content of the (A) curable resin is preferably 5 to 95 mass parts, more preferably 10 to 75 mass parts, and further preferably 20 to 60 mass parts, with respect to 100 mass parts of the total of the (A) curable resin and the (B) ethylenic unsaturated monomer.

[0059] <(A-1) Vinyl ester resin>

[0060] (A-1) Vinyl ester resins are generally compounds having a radically polymerizable unsaturated bond, obtained by ring-opening reaction of an epoxy group in (a) an epoxy compound having two or more epoxy groups, with a carboxyl group of (b) an unsaturated monobasic acid having a radically polymerizable unsaturated bond and a carboxyl group. As to (A-1) vinyl ester resins, for example, they are described in "Polyester Resin Handbook" (published by NIKKAN KOGYO SHIMBUN, LTD., 1988) and the like.

[0061] (A-1) Vinyl ester resins can be used alone, or two or more kinds thereof can be used in combination. (A-1) Vinyl ester resins are generally used diluted with (B) an ethylenically unsaturated monomer from the viewpoint of handling. By using (A-1) vinyl ester resins, it is possible to suppress the material cost of the curable resin composition, and it is possible to obtain a cured product having excellent adhesion.

[0062] The number average molecular weight (Mn) of (A-1) vinyl ester resins can be adjusted according to the desired properties, but it is preferably in the range of 500 to 5,000 from the viewpoint of handling. In the present specification, the "weight average molecular weight" and the "number average molecular weight" are values determined at ordinary temperature (23°C) under the following conditions using gel permeation chromatography (GPC) using a standard polystyrene standard curve.

[0063] Apparatus: Shodex (registered trademark) GPC-101 (Showa Denko K.K.)

[0064] Column: Shodex (registered trademark) LF-804 (Showa Denko K.K.)

[0065] Column temperature: 40°C

[0066] Sample: 0.2 mass% tetrahydrofuran solution of the sample

[0067] Flow rate: 1 mL / minute

[0068] Eluent: Tetrahydrofuran

[0069] Detector: Shodex (registered trademark) RI-71S (Showa Denko K.K.)

[0070] ((a) Epoxy compounds)

[0071] (a) epoxy compound is not particularly limited as long as it is a compound having 2 or more epoxy groups. It is preferable to be at least one selected from the group consisting of bisphenol type epoxy compounds and novolak phenol type epoxy compounds, and more preferable to be a bisphenol type epoxy compound. By using (a) epoxy compound as a raw material for the (A-1) vinyl ester resin, the mechanical strength and corrosion resistance of the cured product are further improved.

[0072] As the bisphenol type epoxy compound, there can be mentioned, for example, a substance obtained by reacting a bisphenol compound such as bisphenol A, bisphenol F, bisphenol S, and tetra-bromobisphenol A, with epichlorohydrin and / or methyl epichlorohydrin; a substance obtained by reacting a condensate of a compound obtained by glycidyl etherifying any one or more of the above bisphenol compounds, with any one or more of the above bisphenol compounds, with epichlorohydrin and / or methyl epichlorohydrin. From the viewpoint of durability, it is preferable to be a reaction product of a bisphenol compound with epichlorohydrin, and more preferable to be a reaction product of bisphenol A with epichlorohydrin.

[0073] As the novolak phenol type epoxy compound, there can be mentioned, for example, a substance obtained by reacting a phenol novolak or a cresol novolak with epichlorohydrin and / or methyl epichlorohydrin.

[0074] ((b) unsaturated monobasic acid)

[0075] The (b) unsaturated monobasic acid is not particularly limited as long as it is a monocarboxylic acid having an ethylenic unsaturated bond. It is preferable to be methacrylic acid, acrylic acid, crotonic acid, cinnamic acid, or the like, and more preferable to be acrylic acid or methacrylic acid, and further preferable to be methacrylic acid from the viewpoint of the corrosion resistance of the cured product.

[0076] ((A-1) vinyl ester resin)

[0077] The (A-1) vinyl ester resin can be synthesized by a publicly known synthesis method. There can be mentioned, for example, a method of adding the (b) unsaturated monobasic acid in the presence of an esterification catalyst and the (a) epoxy compound in a reaction vessel capable of heating and stirring, and allowing it to react at 70 to 150°C, preferably 80 to 140°C, and further preferably 90 to 130°C.

[0078] In addition, the unreacted (b) unsaturated monobasic acid after the synthesis of the (A-1) vinyl ester resin is regarded as the (B) ethylenic unsaturated monomer described later.

[0079] As the esterification catalyst, there can be used, for example, a publicly known catalyst such as a tertiary amine such as triethylamine, N,N-dimethylbenzylamine, N,N-dimethylaniline, diazabicyclooctane, and the like; triphenylphosphine; diethylamine hydrochloride; and the like.

[0080] The mixing ratio of (a) the epoxy compound to (b) the unsaturated monobasic acid is preferably such that the total amount of the carboxyl groups of (b) the unsaturated monobasic acid is 0.3 to 1.2 moles, more preferably 0.4 to 1.1 moles, and further preferably 0.5 to 1.0 mole, relative to 1 mole of the total amount of the epoxy groups of (a) the epoxy compound. If the total amount of the carboxyl groups of (b) the unsaturated monobasic acid is 0.3 moles or more, a cured product having sufficient hardness can be obtained when the curable resin composition is cured. On the other hand, if the total amount of the carboxyl groups of (b) the unsaturated monobasic acid is 1.2 moles or less, the unreacted (b) unsaturated monobasic acid can be reduced when synthesizing the (A-1) vinyl ester resin, and thus the acid value of the mixture of the (A) component and the (B) component can be made small, and a cured product having better adhesion can be obtained.

[0081] The unreacted (b) unsaturated monobasic acid after synthesizing the (A-1) vinyl ester resin can be used directly as the (B) ethylenically unsaturated monomer of the curable resin composition without being removed. When the curable resin composition is heated and cured, the unreacted (b) unsaturated monobasic acid sometimes volatilizes or exudes, which can affect the adhesion of the cured product, and thus it is preferable to reduce the content of the unreacted (b) unsaturated monobasic acid as much as possible. For example, the content of the unreacted (b) unsaturated monobasic acid is preferably 5% by mass or less, and more preferably 3% by mass or less, relative to the total amount of the (A-1) vinyl ester resin and the unreacted (b) unsaturated monobasic acid.

[0082] <(A-2) Unsaturated Polyester Resin>

[0083] The (A-2) unsaturated polyester resin is a condensate of a polyhydric alcohol and an unsaturated polybasic acid, or a condensate of a polyhydric alcohol and an unsaturated polybasic acid and a saturated polybasic acid. The (A-2) unsaturated polyester resin can be used alone or in combination with two or more kinds. By using the (A-2) unsaturated polyester resin, a cured product having excellent mechanical strength and heat resistance can be obtained.

[0084] In addition, in the present disclosure, a styrene monomer or the like contained in a general unsaturated polyester resin is classified as the (B) ethylenically unsaturated monomer.

[0085] The polyhydric alcohol is not particularly limited as long as it is a compound having two or more hydroxyl groups. As the polyhydric alcohol, for example, ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, pentylene glycol, hexylene glycol, neopentyl glycol, tetraethylene glycol, polyethylene glycol, 2-methyl-l,3-propanediol, 1,4-cyclohexane dimethanol, hydrogenated bisphenol A, and the like alkylene glycols; bisphenol A; ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, and the like oxyalkylene-modified bisphenol A; glycerol, and the like can be given. From the viewpoint of heat resistance, mechanical strength of the cured product, and flowability of the curable resin composition at the time of molding, propylene glycol, dipropylene glycol, neopentyl glycol, hydrogenated bisphenol A, and bisphenol A are preferred, and propylene glycol is more preferred. The polyhydric alcohol can be used alone or in combination of two or more.

[0086] The unsaturated polybasic acid is not particularly limited as long as it is a compound having an ethylenic unsaturated bond and having two or more carboxyl groups or an acid anhydride thereof, and a publicly known substance can be used. In particular, since the unsaturated polybasic acid having 4 to 6 carbon atoms or an acid anhydride thereof is more low-cost, and a curable resin composition having more excellent mechanical strength and heat resistance of a cured product can be obtained, it is preferred. As the unsaturated polybasic acid, for example, maleic acid, maleic anhydride, fumaric acid, citraconic acid, itaconic acid, chloromaleic acid, and the like can be given. More preferably, the unsaturated polybasic acid is selected from fumaric acid, maleic acid, maleic anhydride, and itaconic acid. The unsaturated polybasic acid can be used alone or in combination of two or more.

[0087] As the preferred combination of the polyhydric alcohol and the unsaturated polybasic acid, for example, a combination of fumaric acid and neopentyl glycol, a combination of maleic acid and dipropylene glycol, a combination of maleic anhydride and propylene glycol, a combination of fumaric acid and propylene glycol, a combination of fumaric acid and hydrogenated bisphenol A and propylene glycol, and the like can be given. The combination of fumaric acid and propylene glycol, and the combination of fumaric acid and hydrogenated bisphenol A and propylene glycol are more low-cost, and a curable resin composition having a higher heat distortion temperature, more excellent mechanical strength, and heat resistance of a cured product can be obtained, and thus are preferred.

[0088] The saturated polybasic acid is not particularly limited as long as it is a compound not having an ethylenic unsaturated bond and having two or more carboxyl groups or an acid anhydride thereof, and a publicly known substance can be used. As the saturated polybasic acid, for example, phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, tetrachlorophthalic anhydride, tetrabromophthalic anhydride, nitrophthalic acid, halogenated phthalic anhydride, and the like aromatic saturated polybasic acids or acid anhydrides thereof; succinic acid, adipic acid, sebacic acid, oxalic acid, malonic acid, azelaic acid, glutaric acid, and the like aliphatic saturated polybasic acids; hexahydrophthalic anhydride can be given. The saturated polybasic acid can be used alone or in combination of two or more.

[0089] (A-2) The weight-average molecular weight (Mw) of the unsaturated polyester resin is not particularly limited. The weight-average molecular weight of the unsaturated polyester resin is preferably 2,000 to 25,000, more preferably 3,000 to 20,000, and even more preferably 3,500 to 10,000. If the weight-average molecular weight is 2,000 to 25,000, the moldability of the curable resin composition becomes better.

[0090] The degree of unsaturation of the (A-2) unsaturated polyester resin is preferably 50 to 100 mol%, more preferably 60 to 100 mol%, and even more preferably 70 to 100 mol%. If the degree of unsaturation is within the above range, the moldability of the curable resin composition containing the (A-2) unsaturated polyester resin becomes better.

[0091] (A-2) The degree of unsaturation of unsaturated polyester resin can be calculated using the number of moles of unsaturated polybasic acid and saturated polybasic acid used as raw materials, by the following formula.

[0092] Degree of unsaturation (mol%) = {(number of moles of unsaturated polyacid × number of olefinic unsaturated bonds per molecule of unsaturated polyacid) / (number of moles of unsaturated polyacid + number of moles of saturated polyacid)} × 100

[0093] ((A-2) Synthesis method of unsaturated polyester resin)

[0094] (A-2) Unsaturated polyester resins can be synthesized using the above-mentioned raw materials by known methods. (A-2) The various conditions in the synthesis of unsaturated polyester resins are appropriately set according to the raw materials used and their quantities.

[0095] Generally, esterification reactions can be carried out in inert gas streams such as nitrogen, under pressure or reduced pressure at temperatures ranging from 140°C to 230°C. Esterification catalysts can be used as needed. Examples of known esterification catalysts include manganese acetate, dibutyltin oxide, stannous oxalate, zinc acetate, and cobalt acetate. Esterification catalysts can be used alone or in combination of two or more.

[0096] In addition, the unreacted unsaturated polyacids after the synthesis of (A-2) unsaturated polyester resin are considered as the (B) olefinic unsaturated monomers described later.

[0097] In order to increase the molecular weight due to the increased reaction rate and improve the binding strength due to the decrease in acid value, it is preferable that the equivalent of the hydroxyl groups of the polyol is in the range of 0.9 to 1.2 relative to the total amount of carboxyl groups of unsaturated polyacids and any saturated polyacids.

[0098] The unreacted unsaturated polybasic acid and any saturated polybasic acid after the synthesis of the (A-2) unsaturated polyester resin can be present in the curable resin composition without being removed.

[0099] <(A-3) urethane (meth)acrylate resin>

[0100] As the (A-3) urethane (meth)acrylate resin, for example, a resin obtained by introducing a (meth)acryloyl group to both terminal hydroxyl groups or isocyanate groups of a polyurethane obtained by reacting a polybasic isocyanate with a polyol can be used.

[0101] As the polyol, the compounds described as the raw material of the above (A-2) unsaturated polyester resin can be used without particular limitation.

[0102] As the polybasic isocyanate, for example, aliphatic polybasic isocyanates such as 1,6-hexane diisocyanate, lysine diisocyanate, lysine triisocyanate, trimethylhexane diisocyanate, and the like; cyclic aliphatic polybasic isocyanates such as hydrogenated xylene diisocyanate, isophorone diisocyanate, methylcyclohexane-2,4 (or 2,6)-diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), 1,3-(isocyanatomethyl)cyclohexane, and the like; aromatic polybasic isocyanates such as toluene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, and the like; and addition products, isocyanurate bodies, and biuret bodies of these polybasic isocyanates can be mentioned. The polybasic isocyanate can be used alone or in combination of two or more.

[0103] In the introduction of the (meth)acryloyl group, a method of reacting a (meth)acrylic compound containing a hydroxyl group with a terminal isocyanate group, or a method of reacting a (meth)acrylic compound containing an isocyanate group such as 2- (meth)acryloyloxyethyl isocyanate, 2- (meth)acryloyloxypropyl isocyanate, 1,1- bis(acryloyloxymethyl)ethyl isocyanate, and the like with a terminal hydroxyl group can be used. As the (meth)acrylic compound containing a hydroxyl group, (meth)acrylic acid 2-hydroxyethyl ester, (meth)acrylic acid 2-hydroxypropyl ester, (meth)acrylic acid 3-hydroxybutyl ester, caprolactone-modified (meth)acrylic acid hydroxyalkyl ester, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, tris(hydroxyethyl) isocyanuric acid di(meth)acrylate, pentaerythritol tri(meth)acrylate, glycerol mono(meth)acrylate, and hydroxyethyl acrylamide, for example, can be mentioned, with (meth)acrylic acid 2-hydroxyethyl ester, (meth)acrylic acid 2-hydroxypropyl ester, caprolactone-modified (meth)acrylic acid hydroxyalkyl ester, and hydroxyethyl acrylamide being preferred. The (meth)acrylic compound containing an isocyanate group and the (meth)acrylic compound containing a hydroxyl group can each be used alone or in combination with two or more.

[0104] In addition, unreacted (meth)acrylic compound containing a hydroxyl group or unreacted (meth)acrylic compound containing an isocyanate group after synthesis of the (A-3) urethane (meth)acrylic ester resin is regarded as the (B) ethylenically unsaturated monomer described later.

[0105] <(A-4) Diallyl phthalate resin>

[0106] The (A-4) diallyl phthalate resin is an oligomer obtained by esterification of diallyl phthalate with a polyol, and a conventionally known substance can be used without particular limitation. The (A-4) diallyl phthalate resin can be used alone or in combination with two or more.

[0107] In addition, unreacted diallyl phthalate after synthesis of the (A-4) diallyl phthalate resin can be present in the curable resin composition without being removed.

[0108] <(A-5) Epoxy resin>

[0109] As the (A-5) epoxy resin, a compound described in the item of (a) epoxy compound can be used. The (A-5) epoxy resin can be used alone or in combination with two or more.

[0110] [(B) Ethylenically unsaturated monomer]

[0111] (B) The olefinically unsaturated monomer is not particularly limited as long as it is a monomer having an olefinically unsaturated bond. The (B) olefinically unsaturated monomer can be used alone or in combination of two or more.

[0112] From the viewpoint of ensuring the adhesion of the cured product of the curable resin composition, the (B) olefinically unsaturated monomer contains at least an aromatic vinyl compound. Further, from the viewpoint of obtaining a cured product having a good appearance, the above-mentioned aromatic vinyl compound contains at least an aromatic divinyl compound having two vinyl groups.

[0113] The aromatic vinyl compound is not particularly limited as long as it is a compound having an aromatic ring skeleton and a vinyl group. As the aromatic vinyl compound, specifically, there can be mentioned aromatic mono-vinyl compounds such as styrene, vinyltoluene, ethylvinylbenzene, t-butylstyrene, methoxystyrene, vinylnaphthalene, acenaphthylene, and the following aromatic divinyl compounds. From the viewpoint of copolymerizability with the olefinically unsaturated group possessed by the (A) curable resin, styrene, vinyltoluene, ethylvinylbenzene, and t-butylstyrene are preferred.

[0114] The aromatic divinyl compound is not particularly limited as long as it is a compound having an aromatic ring skeleton and two vinyl groups. As the aromatic divinyl compound, specifically, there can be mentioned divinylbenzene, divinyl naphthalene, divinylanthracene, and divinylbiphenyl. From the viewpoint of obtaining a cured product having an excellent appearance, divinylbenzene is preferred.

[0115] The aromatic vinyl compound is preferably composed of divinylbenzene, and at least one selected from the group consisting of ethylvinylbenzene and styrene.

[0116] (B) The olefinically unsaturated monomer can include compounds other than the aromatic vinyl compound. Specifically, mention can be made of methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, furfuryl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, phenyl (meth)acrylate, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyl oxyethyl (meth)acrylate, allyl (meth)acrylate, isobornyl (meth)acrylate, acetoacetoxyethyl (meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, tricyclodecane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and the like (meth)acrylates.

[0117] The content of the (B) olefinically unsaturated monomer is preferably 5 to 95 parts by mass, more preferably 25 to 90 parts by mass, and further preferably 40 to 80 parts by mass, relative to 100 parts by mass of the total of the (A) curable resin and the (B) olefinically unsaturated monomer. If the content of the (B) olefinically unsaturated monomer is 5 parts by mass or more, the viscosity of the curable resin composition can be adjusted to an appropriate range, and the moldability is good. If the content of the (B) olefinically unsaturated monomer is 95 parts by mass or less, the mechanical strength of the cured product is good.

[0118] The proportion of the aromatic vinyl compound included in the (B) olefinically unsaturated monomer is preferably 70 mol% or more, more preferably 80 mol% or more, and further preferably 90 mol% or more. If the proportion of the aromatic vinyl compound is 70 mol% or more, the adhesion of the cured product of the curable resin composition is good. The proportion of the aromatic vinyl compound included in the (B) olefinically unsaturated monomer can be 100 mol% or less, 98 mol% or less, or 95 mol% or less.

[0119] The proportion of the aromatic divinyl compound included in the (B) olefinically unsaturated monomer is preferably 5 to 50 mol%, more preferably 7 to 35 mol%, and further preferably 8 to 30 mol%. If the proportion of the aromatic divinyl compound is 5 mol% or more, a cured product of excellent appearance can be molded. If the proportion of the aromatic divinyl compound is 50 mol% or less, the handleability of the curable resin composition such as storage stability can be improved.

[0120] The total amount of the vinyl groups of the aromatic vinyl compound is preferably 60 to 95 mol%, more preferably 65 to 90 mol%, relative to the total amount of the olefinically unsaturated groups contained in (A) the curable resin and (B) the olefinically unsaturated monomer. If the total amount of the vinyl groups is 60 mol% or more, a sufficient amount of the aromatic vinyl compound is contained, and thus the adhesion of the cured product to the substrate becomes good. If the total amount of the vinyl groups is 95 mol% or less, it is advantageous from the viewpoint of environmental resistance.

[0121] [(C) Inorganic Filler]

[0122] As the (C) inorganic filler, a particulate substance known in the technical field of the present application can be used. By using the (C) inorganic filler, the molding shrinkage of the molded product can be made small, the viscosity of the curable resin composition can be adjusted to improve the workability, or the strength of the molded product can be improved.

[0123] As the (C) inorganic filler, for example, calcium carbonate, silica, alumina, aluminum hydroxide, barium sulfate, calcium sulfate, calcium hydroxide, calcium oxide, magnesium oxide, magnesium hydroxide, wollastonite, clay, kaolin, mica, gypsum, silicic anhydride, glass powder, and the like can be given. Since calcium carbonate, alumina, and aluminum hydroxide are inexpensive, they are preferred. The (C) inorganic filler can be used alone or in combination of two or more.

[0124] The average particle diameter of the (C) inorganic filler is preferably 1 to 100 μm, more preferably 1 to 60 μm, and further preferably 1 to 50 μm. If the average particle diameter of the (C) inorganic filler is 1 μm or more, the aggregation of the particles can be suppressed. On the other hand, if the average particle diameter of the (C) inorganic filler is 100 μm or less, the moldability of the curable resin composition is good.

[0125] In the present specification, the "average particle diameter" is the 50% particle diameter (D50) in the volume-based cumulative particle size distribution measured by a laser diffraction / scattering type particle size distribution measuring device (Microtrack BEL Co., Ltd., FRA).

[0126] The shape of the (C) inorganic filler is not particularly limited. For example, substantially spherical, ellipsoidal, flaky, amorphous, and the like can be given.

[0127] (C) the compounding amount of the inorganic filler is preferably 200 to 700 parts by mass, more preferably 300 to 650 parts by mass, with respect to 100 parts by mass of the total of (A) the curable resin and (B) the ethylenically unsaturated monomer. If the compounding amount of (C) the inorganic filler is 200 parts by mass or more, the mechanical properties of the cured product are more favorable. If the compounding amount of (C) the inorganic filler is 700 parts by mass or less, (C) the inorganic filler is more uniformly dispersed in the curable resin composition, and a homogeneous molded body can be produced.

[0128] [(D) thermal polymerization initiator]

[0129] As the (D) thermal polymerization initiator, there is no particular limitation as long as it is a polymerization initiator that generates radicals by heating. Examples that can be given include peroxides such as diacyl peroxides, ester peroxides, hydroperoxides, dialkyl peroxides, ketone peroxides, peroxyketals, alkyl peroxides, and percarbonates.

[0130] Among these peroxides, as the (D) thermal polymerization initiator, 1,1-di-tert-hexyl peroxy-cyclohexane, tert-hexyl peroxy isopropyl monocarbonate, tert-butyl peroxy octanoate, tert-butyl peroxy-2-ethylhexanoate, tert-hexyl peroxy-2-ethylhexanoate, tert-amyl peroxy-2-ethylhexanoate, benzoyl peroxide, 1,1-di-tert-butyl peroxy-3,3,5-trimethylcyclohexane, tert-butyl peroxy isopropyl carbonate, tert-butyl peroxy benzoate, dicumyl peroxide, and di-tert-butyl peroxide are preferable. The (D) thermal polymerization initiator can be used alone or in combination with two or more kinds.

[0131] The compounding amount of the (D) thermal polymerization initiator is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, and further preferably 1 to 7 parts by mass, with respect to 100 parts by mass of the total of (A) the curable resin and (B) the ethylenically unsaturated monomer. If the compounding amount of the (D) thermal polymerization initiator is 0.1 parts by mass or more, the curing reaction of the curable resin composition during molding proceeds uniformly, and the physical properties and appearance of the cured product become favorable. If the compounding amount of the (D) thermal polymerization initiator is 20 parts by mass or less, the storage stability of the curable resin composition becomes favorable, and the workability improves.

[0132] [(E) glass fiber]

[0133] As the (E) glass fiber, there is no particular limitation as long as it is a fibrous substance having an aspect ratio of 3 or more. Specifically, examples that can be given include chopped strand glass.

[0134] The fiber length of the (E) glass fiber is preferably 20 mm or less, more preferably 10 mm or less, and further preferably 5 mm or less. If the fiber length is 20 mm or less, the moldability of the curable resin composition is good, and the appearance of the cured product is good. The fiber length is preferably 0.1 mm or more, more preferably 0.5 mm or more, and further preferably 1 mm or more. If the fiber length is 0.1 mm or more, the strength of the cured product is good. The average fiber diameter of the (E) glass fiber is preferably 3 to 100 μm, and more preferably 5 to 30 μm.

[0135] The content of the (E) glass fiber is preferably 10 to 300 parts by mass, more preferably 15 to 200 parts by mass, and further preferably 30 to 100 parts by mass, relative to 100 parts by mass of the total of the (A) curable resin and the (B) ethylenically unsaturated monomer. If the content of the (E) glass fiber is 10 parts by mass or more, the mechanical properties of the molded body obtained by the curable resin composition are more excellent. If the content of the (E) glass fiber is 300 parts by mass or less, the (E) glass fiber is more uniformly dispersed in the curable resin composition, and a homogeneous molded body can be produced.

[0136] [(F) Low Shrinkage Agent]

[0137] As the (F) low shrinkage agent, there is no particular limitation, and a substance known in the technical field of the present application can be used. As the (F) low shrinkage agent, a thermoplastic resin is preferred. As the (F) low shrinkage agent, for example, polystyrene, polyethylene, polymethyl methacrylate, polyvinyl acetate, saturated polyester, polycaprolactone, butadiene-styrene rubber, and the like can be mentioned. The (F) low shrinkage agent can be used alone or in combination of two or more.

[0138] The content of the (F) low shrinkage agent is preferably 10 to 80 parts by mass, and more preferably 15 to 50 parts by mass, relative to 100 parts by mass of the total of the (A) curable resin and the (B) ethylenically unsaturated monomer. If the content of the (F) low shrinkage agent is 10 parts by mass or more, the shrinkage of the cured product is small, and the desired dimensional accuracy can be obtained in the molded body. If the content of the (F) low shrinkage agent is 80 parts by mass or less, the mechanical properties of the cured product are more excellent.

[0139] [(G) Acidic Surfactant]

[0140] The curable resin composition can further contain (G) an acidic surfactant as needed. The (G) acidic surfactant is a low volatile substance having a surface active effect and an acid value, and is not particularly limited as long as it is a compound excellent in compatibility with the (A) curable resin and the (B) ethylenically unsaturated monomer, and dispersibility of the (C) inorganic filler and the (E) glass fiber. In a case where the compound corresponds to both of a saturated polybasic acid and the (G) acidic surfactant, the compound is classified as the (G) acidic surfactant.

[0141] In the present disclosure, the so-called low volatile substance is a substance having a weight retention rate of 90% or more under the condition of 150°C for 60 minutes in an atmospheric air. The molecular weight or weight average molecular weight of the low volatile substance is, for example, 500 or more, 1,000 or more, or 1,500 or more. The upper limit of the molecular weight or weight average molecular weight of the low volatile substance is not particularly limited, but can be, for example, 7,000 or less, 6,000 or less, or 5,000 or less.

[0142] As the (G) acidic surfactant, a substance generally known as a dispersant or a plasticizer for a resin composition can be suitably used. It is preferable to be a low volatile oligomer, more preferable to be a low volatile oligomer having a constitutional component including a monomer unit of an ethylene unit, a styrene unit, an ester unit, an ether unit, a urethane unit, and the like, and an acid group of a carboxyl group, a sulfo group, a phosphono group, and the like, further preferable to be a phosphoric acid ester compound or a carboxylic acid ester compound, and still more preferable to be a phosphoric acid ester compound including a long chain polyester structure.

[0143] In order to improve the adhesion of the cured product, it is effective to improve the wettability of the curable resin composition to the substrate (adherend), and thus it is considered that it is important for the curable resin composition to have an acid value. By using the (G) acidic surfactant having an acid value, the adhesion of the cured product is improved. Furthermore, in order to prevent the adhesion of the cured product from being affected due to volatilization or bleeding of the (G) acidic surfactant at the time of heat curing of the curable resin composition, a low volatile substance is used as the (G) acidic surfactant.

[0144] As the above-described phosphoric acid ester compound, a substance described in Japanese Patent Application Publication No. 61-194091, Japanese Patent Application Publication No. 3-112992, Japanese Patent Application Laid-Open No. 2007-527896, Japanese Patent Application Laid-Open No. 2014-520127, and the like can be suitably used. Specifically, a phosphoric acid triester compound of a methyl ester of a 12-hydroxystearic acid polyester, an ester compound of a polyethylene glycol monomethyl ether and malic acid, and an ester compound of tetraphosphoric acid, and the like can be mentioned.

[0145] As the (G) acidic surfactant, commercially available products can also be used, and examples thereof include products manufactured by BYK Additives & Instruments, such as BYK W-9010, BYK W-9011, BYK P-9051, BYK P-9050, BYK P-9060, BYK P-9065, BYK P-9080, and BYK P-9085. From the viewpoint of adhesion of the cured product, BYK W-9010 and BYK P-9051 are preferable.

[0146] The acid value of the (G) acidic surfactant is preferably 20 mgKOH / g or more, more preferably 30 to 190 mgKOH / g, further preferably 100 to 180 mgKOH / g, and particularly preferably 120 to 160 mgKOH / g. If the acid value is 20 mgKOH / g or more, the compounding amount of the (G) acidic surfactant can be suppressed within an appropriate range while ensuring the acid value of the curable resin composition, and thus adverse effects on the properties of the cured product such as adhesion are not caused.

[0147] The content of the (G) acidic surfactant is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 18 parts by mass, and further preferably 1 to 15 parts by mass, relative to 100 parts by mass of the total of the (A) curable resin and the (B) ethylenically unsaturated monomer. If the content of the (G) acidic surfactant is 0.1 parts by mass or more, the curable resin composition has a sufficient acid value, and a cured product having good adhesion can be obtained. If the content of the (G) acidic surfactant is 20 parts by mass or less, adverse effects on the properties of the cured product are not caused.

[0148] [Other additives]

[0149] The curable resin composition can contain, in addition to the above components, components known in the technical field of the present application, such as a thickening agent, a colorant, a polymerization inhibitor, a viscosity modifier such as a viscosity depressant, a mold releasing agent, and the like, without impairing the effects of the present application.

[0150] The thickening agent is a compound other than the (C) inorganic filler that exhibits a thickening effect, and examples thereof include isocyanate compounds. The thickening agent can be used alone or in combination with two or more kinds. The amount of the thickening agent to be added can be appropriately adjusted depending on the handleability, flowability, and the like of the curable resin composition.

[0151] The colorant is used in the case where the cured product is colored, and the like. As the colorant, various dyes, inorganic pigments, or organic pigments can be used. The colorant can be used alone or in combination with two or more kinds. The amount of the colorant to be added can be appropriately adjusted depending on the desired coloring degree of the cured product.

[0152] As the polymerization inhibitor, for example, hydroquinone, trimethylhydroquinone, p-benzoquinone, naphthoquinone, t-butylhydroquinone, catechol, p-t-butylcatechol, 2,6-di-t-butyl-4-methylphenol, and the like can be given. The polymerization inhibitor can be used alone or in combination of two or more. The amount of the polymerization inhibitor to be added can be appropriately adjusted depending on the storage environment and period of the curable resin composition, the curing conditions, and the like.

[0153] 2. Method for producing a curable resin composition

[0154] The curable resin composition can be produced by mixing (A) a curable resin, (B) an ethylenically unsaturated monomer, (C) an inorganic filler, (D) a thermal polymerization initiator, (E) a glass fiber, (F) a low shrinkage agent, (G) an acidic surfactant, other additives than the acidic surfactant, or a combination of two or more of these optional components, as necessary.

[0155] As the mixing method, for example, kneading can be given. As the kneading method, there is no particular limitation, and for example, kneading using a kneader, a disperser, a planetary mixer, or the like can be given. The kneading temperature is preferably 5°C to 50°C, and more preferably 10 to 40°C.

[0156] There is no particular limitation on the order in which the components are mixed when producing the curable resin composition. For example, if (A) the curable resin is mixed with part or all of (B) the ethylenically unsaturated monomer, and then the other components are mixed, a curable resin composition in which the components are sufficiently dispersed or uniformly mixed is easily obtained, and thus is preferable. At least part of (B) the ethylenically unsaturated monomer can be mixed with (A) the curable resin in advance so as to function as a solvent, a dispersion medium, or the like.

[0157] As the mixing method of (E) the glass fiber, a method in which a glass fiber having a prescribed fiber length distribution is prepared in advance, and (E) the glass fiber is mixed in a composition containing the other components except for (E) the glass fiber can be given. According to this method, the fiber length distribution of (E) the glass fiber can be finely adjusted. In addition to this, a method in which (E) the glass fiber is broken by kneading after a curable resin composition containing (E) the glass fiber is prepared, and a prescribed fiber length distribution is achieved can be given. The fiber length distribution of (E) the glass fiber can be controlled by the kind and amount of the other components to be kneaded, the kind of the stirrer, the stirring speed, the stirring temperature, the stirring time, and the like. This method is simple in terms of the process because it does not require the breaking of (E) the glass fiber in advance.

[0158] 3. Method for producing a cured product

[0159] The curable resin composition can be cured by heating. The conditions for curing the curable resin composition can be appropriately set according to the materials used, and as an example of a preferred condition, a temperature of 120 to 180°C, more preferably 120°C to 160°C, and a curing time of 1 to 30 minutes.

[0160] 4. Method for producing a molded body

[0161] A molded body containing a cured product of the curable resin composition can be produced by molding the curable resin composition into a desired shape and curing it. As the molding and curing method, there is no particular limitation, and a method generally performed in the technical field of the present application, such as compression molding, transfer molding, injection molding, and the like, can be used.

[0162] For example, there are a method of opening a mold, injecting the curable resin composition into the mold, and curing it, a method of injecting the curable resin composition into a mold having a hole provided therein through an injection port or the like under reduced pressure or in a state where pressure is applied from the outside of the mold as typified by injection molding, and curing it in the closed mold, and the like. The conditions for curing the curable resin composition in the mold can be appropriately set according to the materials used, and as an example of a preferred condition, a temperature of 120 to 180°C, more preferably 120°C to 160°C, and a curing time of 1 to 30 minutes.

[0163] In one embodiment, an electrical and electronic component provided with a cured product of the curable resin composition is provided. The electrical and electronic component can be produced, for example, by enclosing constituent components of the electrical and electronic component with the curable resin composition, and curing the curable resin composition by heating. The enclosing of the constituent components of the electrical and electronic component can be performed, for example, by injecting the curable resin composition into a case having the constituent components therein.

[0164] From the viewpoint of adhesion, the curable resin composition is suitably used for a polyphenylene sulfide (PPS) substrate, a polybutylene terephthalate (PBT) substrate, an epoxy glass substrate, and a copper substrate. The curable resin composition can particularly obtain excellent adhesion to a difficultly adherable resin substrate such as a PPS substrate. By using the curable resin composition, a surface treatment process using a primer, plasma, or the like for a difficultly adherable resin substrate such as a PPS substrate can generally be omitted.

[0165] Example

[0166] Hereinafter, the present application will be further specifically described by examples and comparative examples, but the present application is not limited to the following examples.

[0167] The following shows a synthesis example of (A) a curable resin.

[0168] [Synthesis Example 1] Synthesis of a vinyl ester resin (A-1)

[0169] In a 1L four-necked flask equipped with a thermometer, a stirrer, a gas inlet, and a reflux cooler, 478.9g of a bisphenol A type epoxy resin, Araldite (registered trademark) AER-2603 (Asahi Kasei Materials Corporation) having an epoxy equivalent of 188.0, 73.1g of methyl methacrylate in which 0.35g of methylhydroquinone was dissolved, were added, and warmed while stirring. At the time when the temperature became 100 to 110°C, 146.2g of methyl methacrylate in which 1.4g of 2,4,6-tris(dimethylaminomethyl)phenol (Seiko Chemicals, Ltd.) was dissolved was added dropwise over 30 minutes, and it was allowed to react at 130°C. At the time when the acid value became 30 mgKOH / g or less, 150g of styrene and 0.1g of hydroquinone were added, and a bisphenol A type vinyl ester resin containing 25 mass% of styrene and 2 mass% of unreacted methyl methacrylate was synthesized.

[0170] As to other components, the following substances were used.

[0171] (B) Ethylenically unsaturated monomer:

[0172] • Styrene (Showa Denko K.K.)

[0173] • DVB-570 (mixture of divinylbenzene 57 mass%, ethylvinylbenzene 43 mass%, Nippon Shokubai & Material Co., Ltd.)

[0174] • EGDMA: ethylene glycol dimethacrylate (Hitachi Chemical Co., Ltd.)

[0175] (C) Inorganic filler:

[0176] • Softon 1200 (calcium carbonate, average particle diameter 1.80 μm, Kitagawa Powder Industry Co., Ltd.)

[0177] (D) Thermal polymerization initiator:

[0178] • Luperox 575 (t-amylperoxy-2-ethylhexanoate, Arakawa Chemical Industries, Ltd.)

[0179] (E) Glass fiber:

[0180] • ECS-03B173 / P9 (fiber diameter 13 μm, fiber length 3 mm, Nippon Electric Glass Co., Ltd.)

[0181] (F) Low shrinkage agent:

[0182] • Polyethylene powder (Takahara Chemical Industry Co., Ltd.)

[0183] (G) acidic surfactant:

[0184] • BYK P-9051 (polyester-based dispersant, acid value 157 mgKOH / g, BYK

[0185] Example 1

[0186] (Production of curable resin composition)

[0187] A styrene dilution bisphenol A type vinyl ester resin 64.3 parts by mass (containing bisphenol A type vinyl ester resin 47 parts by mass, styrene 16 parts by mass, unreacted methacrylic acid 1.3 parts by mass) synthesized in Synthesis Example 1 as (A) curable resin, DVB-570 20 parts by mass (divinylbenzene 11.4 parts by mass, ethylvinylbenzene 8.6 parts by mass) as (B) ethylenically unsaturated monomer, Softon 1200 480 parts by mass as (C) inorganic filler, Luperox 575 4 parts by mass as (D) thermal polymerization initiator, ECS-03B173 / P9 70 parts by mass as (E) glass fiber, polyethylene powder 30 parts by mass as (F) low shrinkage agent, and BYK P-9051 10 parts by mass as (G) acidic surfactant were put into a double-arm kneader, mixed at 30°C for 30 minutes, and a curable resin composition was produced.

[0188] (Production of cured product)

[0189] Using the produced curable resin composition, a transfer molding machine (Model MF-070, Press Machine Laboratory Co., Ltd.) was used to mold under the conditions of mold temperature 140°C, molding pressure 15 kgf / cm 2 , and curing time 180 seconds, and a molded product (cured product) in the shape of a pudding cup (diameter 5 mm on the substrate side, height 3 mm) was obtained on a PPS (polyphenylene sulfide) substrate.

[0190] (Evaluation of adhesion of cured product to substrate)

[0191] The obtained molded product was measured for strength at the time of shear failure using a mold shear testing machine (Dayi Co., Ltd.) at a constant rate of 2 mm / min at 25°C, and the average value of 5 times was taken as the adhesion force. The results are shown in Table 1.

[0192] (Evaluation of molding shrinkage of cured product)

[0193] The molded shrinkage rate was calculated according to JIS K 6911:2006 "5.7 Molded Shrinkage and Heat Shrinkage (Molded Materials)", under the conditions of a molding temperature of 140°C, a molding pressure of 5 MPa, and a molding time of 3 minutes, by compression molding (compression molding machine, Techno Mart Corp.) of a shrinkage disc (φ90 mm x 11 mm). The results are shown in Table 1.

[0194] (Visual evaluation of molded product)

[0195] With respect to the molded product of the molded shrinkage disc described above, the number of spots caused by cracks appearing on the surface was evaluated. The evaluation criteria are described below. The results are shown in Table 1.

[0196] 10 points ••• no spots

[0197] 9 points ••• 3 or fewer spots

[0198] 8 points ••• 4 to 8 spots

[0199] 7 points ••• 9 to 11 spots

[0200] 6 points ••• 12 to 14 spots

[0201] 5 points ••• 15 to 17 spots

[0202] 4 points ••• 18 to 20 spots

[0203] 3 points ••• 21 to 23 spots

[0204] 2 points ••• 24 to 26 spots

[0205] 1 point ••• 27 to 29 spots

[0206] 0 points ••• 30 or more spots

[0207] (Evaluation of injection moldability)

[0208] The same shape as the molded shrinkage disc described above was produced under the same conditions using an injection molding machine, and the injection moldability was evaluated. If it was a good product with no problems, it was evaluated as good, and if it could not be molded due to, for example, underfilling, it was evaluated as not qualified. The results are shown in Table 1.

[0209] <Examples 2 to 4, Comparative Examples 1 to 6>

[0210] A curable resin composition was produced by changing the kind and composition of the raw materials as described in Table 1, and otherwise, operating in the same manner as in Example 1. In addition, the styrene used for dilution of (A) curable resin was excluded from the compounding amount of the (A) component, and was included in the compounding amount of the (B) ethylenically unsaturated monomer. Then, a cured product was produced by operating in the same manner as in Example 1, and various evaluations were performed. The results are shown in Table 1.

[0211] [Table 1]

[0212]

[0213] The results shown in Table 1 show that the molded products of Examples 1 to 4 and Comparative Examples 4 to 6 have high adhesion to the PPS substrate. It is considered that by adjusting the proportion of the total amount of the vinyl groups possessed by the aromatic vinyl compound to the total amount of the ethylenically unsaturated groups included in the (A) curable resin and the (B) ethylenically unsaturated monomer to a prescribed range, the wettability to the substrate is improved, and high adhesion is obtained.

[0214] On the other hand, in Comparative Examples 1 to 3 in which the proportion of the total amount of the vinyl groups possessed by the aromatic vinyl compound is low, the adhesion is low. It is considered that this is because the crosslinked structure is not a structure suitable for adhesion, and the effect of improving the wettability to the substrate is insufficient, and the adhesion does not develop.

[0215] In Examples 1 to 4 containing divinylbenzene, the appearance of the molded product is also good. It is considered that by increasing the crosslinking density of the cured product, cracks are suppressed.

[0216] On the other hand, in Comparative Examples 4 to 6 in which the adhesion to the PPS substrate is high, but divinylbenzene is not contained, the appearance of the molded product is poor compared to Examples 1 to 4. It is considered that the insufficient crosslinking density of the cured product is the cause of the high occurrence of cracks.

[0217] The composition of Examples 1 to 4 is suitable for use as a BMC (Bulk Molding Compound), and a curable resin composition which is excellent in injection moldability, and has a small molding shrinkage can be provided.

[0218] Industrial applicability

[0219] According to the present application, a curable resin composition which can obtain a cured product having excellent adhesion to a substrate, particularly a difficult-to-bond resin substrate, and having a good appearance is provided. In addition, an electrical and electronic component provided with such a cured product as a sealing material, a method for manufacturing the same are provided. The curable resin composition is preferably used in sealing of a wiring substrate and an electronic component mounted on the wiring substrate, and the like used in electronic devices such as electronic control units of motors, coils, connectors, automobiles, and the like, and fixing applications.

Claims

1. A sealing material as a cured product of a curable resin composition, said curable resin composition comprising... (A) Curing resin, (B) Unsaturated olefinic monomers, (C) Inorganic filler materials, (D) Thermal polymerization initiator, (E) Glass fiber, and (F) Low shrinkage agent, The curable resin (A) contains at least a vinyl ester resin. The (B) olefinic unsaturated monomer contains at least an aromatic vinyl compound. The aromatic vinyl compound contains at least an aromatic divinyl compound. The proportion of aromatic divinyl compounds contained in the (B) olefinic unsaturated monomer is 5-50 mol%. The total amount of vinyl groups in the aromatic vinyl compound is in a ratio of 60 to 95 mol to the total amount of olefinic unsaturated groups contained in the (A) curable resin and the (B) olefinic unsaturated monomer.

2. The sealing material as a cured product of a curable resin composition according to claim 1, wherein the (B) olefinic unsaturated monomer contains an aromatic vinyl compound in a proportion of 70 mol% or more.

3. The sealing material as a cured product of a curable resin composition according to claim 1 or 2, wherein the aromatic divinyl compound is divinylbenzene.

4. The sealing material as a cured product of a curable resin composition according to claim 1 or 2, wherein the aromatic vinyl compound comprises divinylbenzene and at least one selected from ethylvinylbenzene and styrene.

5. The sealing material as a cured product of a curable resin composition according to claim 1 or 2, wherein, Relative to a total of 100 parts by mass of (A) curable resin and (B) olefinic unsaturated monomer, it contains (A) 5-95 parts by weight of curing resin (B) 5-95 parts by weight of olefinic unsaturated monomers (C) 200-700 parts by weight of inorganic filler material (D) 0.1–20 parts by weight of thermal polymerization initiator (E) 10-300 parts by weight of glass fiber, and (F) 10-80 parts by weight of low shrinkage agent.

6. The sealing material as a cured product of a curable resin composition according to claim 1 or 2, further comprising (G) an acidic surfactant.

7. An electrical and electronic component comprising a sealing material as a cured product of a curable resin composition as described in any one of claims 1 to 6.

8. A method for manufacturing an electrical and electronic component, comprising the steps of: injection molding a curable resin composition according to any one of claims 1 to 6, and encapsulating a component of the electrical and electronic component therein; and heating and curing the curable resin composition.

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