JP2012031431A - Thermosetting resin composition and method of producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin composition which is excellent toughness in a high temperature without lowering excellent heat resistance or formability in a thermosetting resin, especially in an epoxy resin.SOLUTION: A thermosetting resin composition comprises (a) an epoxy resin, (b) a curing agent, and (c) a silicone polymer containing bifunctional siloxane units represented by formula RSiOin the molecule (wherein, R is equal or different organic group) as essential components.

Description

  The present invention relates to a thermosetting resin composition such as an epoxy resin and a method for producing the same.

  Epoxy resin, which is one of thermosetting resins, is widely used in electronic materials and paints due to its excellent moldability, adhesion, insulation reliability, and the like. Among these, electronic materials are used in a wide variety of applications such as laminates used for printed wiring boards, resist inks, sealing materials used around semiconductors, die bond materials, and underfill materials. In recent years, along with the widespread use of information terminal electronic devices such as personal computers and mobile phones, the progress of miniaturization and high performance of various electronic components mounted therein has been remarkable. For this reason, mounting components such as a printed wiring board and a package mounted thereon must be thinner, smaller, and more reliable to withstand high-density mounting.

Under such circumstances, higher heat resistance and adhesiveness are required for epoxy resins used in these electronic components.
Conventionally, as a method for improving the heat resistance of an epoxy resin, a polyfunctional epoxy resin or a curing agent represented by a novolac type is generally used. However, these cured products have a drawback that they become hard and brittle because of high crosslinking density. Such a hard and brittle resin tends to reduce heat resistance after moisture absorption and adhesion to metal.

  On the other hand, as a measure for improving the adhesiveness of the epoxy resin, a method of reducing the crosslink density of the cured resin and increasing the elongation is common. However, when the crosslink density is lowered, the glass transition temperature (hereinafter referred to as Tg) is lowered, which causes a problem that mechanical properties at high temperatures are lowered, and adversely affects the reliability of the wiring board. There is a risk. This tendency is a very big problem at present when electronic parts are thin and dense and the number of reflows for solder connection is increasing. Furthermore, it is expected that electronic materials will be exposed to high-temperature atmospheres as the development of materials taking the global environment into consideration, such as solder containing no lead, advances. For this reason, the epoxy resin is required to satisfy both high heat resistance and high toughness. In order to satisfy these characteristics, it is important to have a high Tg and to exhibit a certain degree of low elasticity in a high temperature range.

  A typical method for improving adhesiveness without reducing heat resistance is a method of modifying using a thermoplastic resin or the like. For example, a highly brittle and highly crosslinked heat-resistant epoxy resin may be modified by blending a heat-resistant thermoplastic resin with high toughness. However, as represented by super engineering plastics, thermoplastic resins with excellent heat resistance have a high softening point and a very high melt viscosity. For this reason, even if an epoxy resin can be modified | denatured successfully, the melt viscosity of the modified epoxy resin obtained becomes high, and there exists a problem that a moldability falls remarkably compared with the conventional epoxy resin generally shape | molded by heating and pressurization. is there. In addition, thermoplastic resins generally have low polarity and low adhesion to metals, and as a result, adhesion of modified epoxy resins often decreases. In addition, the modulus of elasticity near room temperature tends to decrease, and the handleability and rigidity tend to be low.

  Recently, as one of the modification methods for epoxy resins, there are blends with inorganic compounds as disclosed in JP-A-8-100107, JP-A-10-298405 and JP-A-11-92623. However, all of these methods are those in which a hard gelled material having a high elastic modulus is blended into a thermosetting resin by sol-gel or the like, and although high heat resistance is exhibited, the toughness in a high temperature range is lowered. End up.

  The present invention eliminates the above-mentioned problems of the prior art and provides an epoxy resin composition excellent in toughness at high temperature without impairing the excellent heat resistance and moldability of thermosetting resins, particularly epoxy resins. It is intended.

As a result of intensive studies, the present inventors have found that a composition in which a silicone polymer having a bifunctional siloxane unit represented by the formula R ₂ SiO _2/2 in its molecule is blended with an epoxy resin and its curing agent. The present invention has been completed by finding out that the object of the present invention can be achieved.

  That is, the gist of the present invention is a thermosetting resin composition characterized in that the cured product has a storage elastic modulus at 25 ° C. of 1.0 GPa or more and a storage elastic modulus at 200 ° C. of 100 MPa or less.

  Furthermore, the gist of the present invention is a thermosetting resin composition comprising an epoxy resin and a curing agent as essential components and a cured elastic modulus at 200 ° C. of 100 MPa or less.

The resin composition of the present invention is characterized in that the cured product has a glass transition temperature of 170 ° C. or higher.
Further, the resin composition of the present invention contains a silicone polymer having a bifunctional siloxane unit represented by the formula R ₂ SiO _2/2 (wherein R is the same or different organic group) in the molecule. It is characterized by doing.
The resin composition of the present invention is characterized by containing 2 parts by mass or more of a silicone polymer with respect to 100 parts by mass of an epoxy resin.

Furthermore, the present invention relates to (a) an epoxy resin, (b) a curing agent, and (c) ₂ represented by the formula R ₂ SiO _2/2 (wherein R is the same or different organic group). The gist is a thermosetting resin composition containing a silicone polymer containing a functional siloxane unit as an essential component.
The resin composition of the present invention is characterized in that the curing agent (b) is a phenol resin.
In the resin composition of the present invention, the silicone polymer of (c) is a bifunctional siloxane represented by the formula R ₂ SiO _2/2 (wherein R is the same or different organic group) in the molecule. It contains a trifunctional siloxane unit represented by the unit and the formula RSiO _3/2 (wherein R is the same or different organic group).
In the resin composition of the present invention, the silicone polymer of (c) is a bifunctional siloxane represented by the formula R ₂ SiO _2/2 (wherein R is the same or different organic group) in the molecule. Units and tetrafunctional siloxane units of the formula SiO _4/2 are contained.
In the resin composition of the present invention, the silicone polymer of (c) is a bifunctional siloxane represented by the formula R ₂ SiO _2/2 (wherein R is the same or different organic group) in the molecule. Unit, a trifunctional siloxane unit represented by the formula RSiO _3/2 (wherein R is the same or different organic group) and a tetrafunctional siloxane unit represented by the formula SiO _4/2 And
Further, the resin composition of the present invention is characterized in that the bifunctional siloxane unit contained in the molecule of the silicone polymer (c) is 10 mol% or more of the whole silicone polymer.
The resin composition of the present invention is characterized in that the average degree of polymerization of the silicone polymer (c) is 2 to 2,000.
The resin composition of the present invention is characterized in that the amount of the silicone polymer (c) is 2% by mass or more based on the epoxy resin.
The resin composition of the present invention is characterized in that at least one of the terminals of the silicone polymer (c) is a silanol group or an alkoxy group.
Moreover, the resin composition of the present invention further comprises a coupling agent.
The resin composition of the present invention is characterized in that the silicone polymer (c) contains a monomer of a bifunctional silane compound, a trifunctional silane compound, or a tetrafunctional silane compound.
In the resin composition of the present invention, the silicone polymer (c) is a single oligomer of one compound selected from a bifunctional silane compound, a trifunctional silane compound, and a tetrafunctional silane compound, or their A composite oligomer of two or more kinds of compounds is mixed.

Furthermore, the gist of the present invention is a method for producing the thermosetting resin composition, wherein the component (a), the component (b) and the component (c) are blended simultaneously.
Furthermore, the present invention provides a method for producing the thermosetting resin composition, wherein the components (a), (b) and (c) are blended and stirred simultaneously in the presence of a solvent. And
Furthermore, the present invention uses, as the silicone polymer of (c) above, a solution obtained by oligomerizing a bifunctional silane compound and a mixture of a trifunctional silane compound and / or a tetrafunctional silane compound in the presence of a catalyst. The gist is a method for producing the thermosetting resin composition described above.

  Since the epoxy resin composition of the present invention exhibits excellent toughness at high temperature after curing, it has excellent moldability and adhesiveness, and since there is no decrease in elastic modulus at room temperature, rigidity and handleability. Excellent. Furthermore, a highly reliable substrate can be obtained by selecting a thermosetting resin that maintains a high Tg.

  The epoxy resin (a) used in the present invention is not particularly limited as long as it is polyfunctional. For example, bisphenol type epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol, etc. Novolac epoxy resins, cresol novolac epoxy resins, bisphenol A novolac epoxy resins, bisphenol F novolac epoxy resins and other novolac epoxy resins, alicyclic epoxy resins, glycidyl ester epoxy resins, glycidyl amine epoxy resins, hydantoins Type epoxy resin, isocyanurate type epoxy resin, aliphatic chain epoxy resin and their halides, hydrogenated products, etc., any molecular weight may be used, and several types may be used in combination Kill. Bisphenol type epoxy resins and novolac type epoxy resins are preferably used, and novolac type epoxy resins are particularly preferable from the viewpoint of heat resistance.

  As the curing agent (b), various conventionally known epoxy resin curing agents can be used, and are not particularly limited. For example, polyfunctional phenol resins such as dicyandiamide, diaminodiphenylmethane, diaminodiphenylsulfone, phthalic anhydride, pyromellitic anhydride, phenol novolac and cresol novolac can be exemplified. Several kinds of these curing agents can be used in combination. In order to improve heat resistance by improving Tg or the like, it is preferable to use a phenol resin. Among these, novolac type phenol resins are preferable. Although the compounding quantity of a hardening | curing agent is not specifically limited, About 0.5-1.5 equivalent is preferable with respect to the functional group of main materials, such as an epoxy resin.

The silicone polymer (c) is intended to improve toughness in a high temperature range, and therefore is particularly limited as long as it has at least a bifunctional siloxane unit (R ₂ SiO _2/2 ) in the siloxane unit. It is not a thing. Preferably, at least one kind selected from trifunctional siloxane units (RSiO _3/2 ) and tetrafunctional siloxane units (SiO _4/2 ) (wherein R is as defined above). A siloxane unit is used in combination, and the average degree of polymerization is preferably 2 to 2,000. A more preferable average degree of polymerization is 5 to 1,000, and a particularly preferable average degree of polymerization is 10 to 100. Here, the average degree of polymerization is calculated from the molecular weight of the polymer (in the case of a low degree of polymerization) or the number average molecular weight measured by gel permeation chromatography using a standard polystyrene or polyethylene glycol calibration curve. . Monomers and composite oligomers of various siloxane units may be mixed in the silicone polymer. However, when the average degree of polymerization exceeds 2,000, the viscosity is too high and uniform dispersion becomes difficult.

  Examples of the organic group for R include an alkyl group having 1 to 4 carbon atoms and a phenyl group. Examples of the functional group at the terminal of the oligomer include a silanol group, an alkoxy group having 1 to 4 carbon atoms, and an acyloxy group having 1 to 4 carbon atoms.

  Since the silicone polymer in the present invention is intended to improve toughness at high temperatures, those polymerized with only a trifunctional siloxane unit or a tetrafunctional siloxane unit become too stiff and exhibit high toughness. It becomes difficult. For example, those consisting only of bifunctional siloxane units, those consisting of bifunctional siloxane units and tetrafunctional siloxane units, those consisting of bifunctional siloxane units and trifunctional siloxane units, bifunctional siloxane units and trifunctional What consists of a functional siloxane unit and a tetrafunctional siloxane unit is preferable. Moreover, in order for these silicone polymers to disperse | distribute uniformly in a resin hardened | cured material, it is preferable that at least 1 of the terminal of a silicone polymer has a functional group. A silicone polymer having no functional group hardly penetrates into the epoxy resin, and oozes out on the surface of the cured resin during molding or the like, so that uniform dispersion cannot be expected.

  The amount of the monomer forming the siloxane unit is 10 to 100 mol%, preferably 25 to 90 mol%, and the trifunctional siloxane unit and the tetrafunctional siloxane unit with respect to the total siloxane units. Is adjusted to be 0 to 90 mol%, preferably 10 to 75 mol%.

The silicone polymer in the present invention can be obtained by hydrolyzing and polycondensing a silane compound represented by the following general formula (I).
R ' _n SiX _4-n (I)
In the above formula, X represents —OR, and R represents an alkyl group having 1 to 4 carbon atoms or an alkylcarbonyl group having 1 to 4 carbon atoms. R ′ represents an alkyl group having 1 to 4 carbon atoms or an aryl group such as a phenyl group, and n represents an integer of 0 to 2.

等のテトラアルコキシシラン等の４官能性シラン化合物（以下、シラン化合物における官能性とは、縮合反応性の官能基を有することを意味する。）、

等のモノアルキルトリアルコキシシラン、

（但し、Ｐｈはフェニル基を示す。以下同様）
等のフェニルトリアルコキシシラン、

等のモノアルキルトリアシルオキシシラン等の３官能性シラン化合物、

等のジアルキルジアルコキシシラン、

等のジフェニルジアルコキシシラン、

等のジアルキルジアシルオキシシラン等の２官能性シラン化合物等がある。 Specifically, the silane compound represented by the general formula (I) is

Tetrafunctional silane compounds such as tetraalkoxysilane (hereinafter, the functionality in the silane compound means having a condensation-reactive functional group),

Monoalkyltrialkoxysilane such as

(However, Ph represents a phenyl group. The same applies hereinafter.)
Phenyltrialkoxysilane, etc.

Trifunctional silane compounds such as monoalkyltriacyloxysilane

Dialkyl dialkoxysilanes such as

Diphenyl dialkoxysilane, etc.

And bifunctional silane compounds such as dialkyldiacyloxysilane.

  In the silane compound represented by the general formula (I) used in the present invention, a bifunctional silane compound is used as an essential component, and a trifunctional silane compound or a tetrafunctional silane compound is appropriately used as necessary. The In particular, the difunctional dialkoxysilane is preferable as the bifunctional silane compound, the monoalkyltrialkoxysilane is preferable as the trifunctional silane compound, and the tetraalkoxysilane is preferable as the tetrafunctional silane compound.

  The silicone polymer in the present invention is produced by hydrolysis and polycondensation of the silane compound represented by the general formula (I). At this time, examples of the catalyst include hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, Inorganic acids such as hydrofluoric acid, and organic acids such as oxalic acid, maleic acid, sulfonic acid and formic acid are preferably used, and basic catalysts such as ammonia and trimethylammonium can also be used. These catalysts are used in an appropriate amount depending on the amount of the silane compound represented by the general formula (I), but preferably 0.001 to 0.003 per mole of the silane compound represented by the general formula (I). It is used in the range of 5 moles.

  In addition, it is important that the hydrolysis / polycondensation is performed in advance before blending into the epoxy resin composition. In this reaction, any solvent may be used in order to obtain a uniform polymer. The solvent used is not particularly limited, and examples thereof include various alcohols, ketones, cellosolves, amides, and the like. This reaction is also promoted by water. The amount of water is also appropriately determined, but it is usually 5 mol or less, preferably 0.1 to 2 mol per mol of alkoxy group. When the amount of water is too large, problems such as a decrease in the storage stability of the silicone polymer and a decrease in the toughness of the cured resin may occur.

  These silicone polymers may be used in combination with various coupling agents. Examples of coupling agents include silane coupling agents and titanate coupling agents. Generally, silane coupling agents include epoxy silane, amino silane, cationic silane, vinyl silane, acrylic silane, and mercapto. There are silane type and composite type of these.

  The compounding amount of these silicone polymers is determined by the resin composition to be used, the level of toughness to be expressed, the composition of the silicone polymer, etc., and is not particularly limited, but is preferably 2 to 50% by mass with respect to the epoxy resin. . When the amount is less than 2% by mass, the effect of improving toughness is weak, and when the amount is more than 50% by mass, the heat resistance tends to decrease.

The epoxy resin composition of the present invention can use a curing accelerator for the purpose of accelerating curing. The curing accelerator is not particularly limited as long as it accelerates the reaction between the epoxy resin and the curing agent. For example, an imidazole compound, an organic phosphorus compound, a tertiary amine, a quaternary ammonium salt, or the like is used. Examples of the imidazole compound used here include imidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 1-benzyl-2-methylimidazole, and 2-heptadecylimidazole. 4,5-diphenylimidazole, 2-methylimidazoline, 2-phenylimidazoline, 2-undecylimidazoline, 2-heptadecylimidazoline, 2-isopropylimidazole, 2,4-dimethylimidazole, 2-phenyl-4-methylimidazole 2-ethylimidazoline, 2-isopropylimidazoline, 2,4-dimethylimidazoline, 2-phenyl-4-methylimidazoline, and the like, and some of these imino groups are masked. Examples of the masking agent include acrylonitrile, phenylene diisocyanate, toluene diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, methylene bisphenyl isocyanate, and melamine acrylate.
Some of these curing accelerators may be used in combination, and the blending amount is preferably 0.01 to 5 parts by mass with respect to 100 parts by mass of the epoxy resin. When the amount is less than 0.01 parts by mass, the promoting effect is small, and when the amount is more than 5 parts by mass, the storage stability is deteriorated.

  You may mix | blend an inorganic filler with the epoxy resin composition of this invention as needed. Examples of the inorganic filler include silica, clay, talc, mica, aluminum hydroxide, calcium carbonate, alumina, glass fiber, and glass powder.

  A solvent is used when diluting these resin materials into varnishes. There are no particular restrictions on this solvent, and examples include acetone, methyl ethyl ketone, toluene, xylene, methyl isobutyl ketone, ethyl acetate, ethylene glycol monomethyl ether, N, N-dimethylformamide, methanol, and ethanol. May be. The solid content concentration of the varnish is not particularly limited, and can be appropriately changed depending on the resin composition, the presence or absence of an inorganic filler, the blending amount, and the like.

  The varnish obtained by blending the above components is dried for the purpose of volatilizing the solvent and curing the resin to some extent, and then cured by heating to obtain a cured product. The heating temperature, time, and the like vary greatly depending on the resin composition and the composition of the silicone polymer, but are generally cured at a temperature of 20 ° C. to 230 ° C. for 15 minutes to 24 hours. In some cases, pressure molding may be performed as necessary. This cured product expresses the intended toughness by dispersing a silicone gel product of several μm or less in the cured epoxy resin.

  In general, considering the handleability, rigidity, and the like of a printed wiring board, the resin composition used for the printed wiring board is required to have an elastic modulus of a cured product near room temperature of 1.0 GPa or more. There is no particular upper limit on the modulus of elasticity of the cured product near room temperature, but it is usually about 10.0 GPa considering the balance with other characteristics. In consideration of heat resistance during solder reflow, adhesion to metal, and the like, the elastic modulus of the cured resin is required to be 100 MPa or less at a high temperature of 200 ° C. or more, and preferably 80 MPa or less. . There is no particular lower limit on the elastic modulus of the cured product at high temperatures, but it is usually about 1 MPa. Also, if the Tg of the resin cured product is low, the mechanical properties at high temperatures will deteriorate, and the reliability of the wiring board such as through hole connection reliability may be adversely affected. Preferably there is. Tg is preferably as high as possible, and there is no particular upper limit. However, when an epoxy resin is used as the thermosetting resin, the upper limit is usually about 200 ° C.

  As described above, the elasticity of the cured product near room temperature is 1.0 MPa or more, and by using a resin composition in which the modulus of elasticity of the cured resin is 100 MPa or less at a high temperature of 200 ° C. or more, handling properties are improved. In addition, it is possible to produce a printed wiring board having excellent rigidity, heat resistance, adhesiveness, reliability, and the like of a molded product. As such a resin composition, an epoxy resin composition having an elastic modulus of a resin cured product of 100 MPa or less can be used at a high temperature of 200 ° C. or higher. As a specific example, the above-mentioned silicone polymer is contained. An epoxy resin composition is mentioned.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In addition, the part in an Example and a comparative example is a mass part.

Example 1
A solution containing 40 g of dimethoxydimethylsilane and 10 g of methanol in a glass flask equipped with a stirrer, condenser and thermometer was mixed with 0.33 g of acetic acid and 12 g of distilled water, and then stirred at 50 ° C. for 8 hours. A coalescence was synthesized. The average polymerization degree of the siloxane repeating unit of the obtained silicone polymer was 10. 25 parts of this polymer solution was blended with the following epoxy resin composition in terms of solid content to prepare a varnish.
Cresol novolac type epoxy resin (manufactured by Sumitomo Chemical Co., Ltd., trade name: ESCN-195, epoxy equivalent 195), phenol novolac resin (manufactured by Hitachi Chemical Co., Ltd., trade name: HP-850N, hydroxyl equivalent 106) ) 55 parts, 0.5 part of 2-ethyl-4-methylimidazole and 35 parts of methyl ethyl ketone are mixed to obtain an epoxy resin composition.

(Example 2)
As in Example 1, 0.31 g of acetic acid and 13.7 g of distilled water were added to a solution containing 30 g of dimethoxydimethylsilane, 10 g of tetramethoxysilane, and 10 g of methanol, and then stirred at 50 ° C. for 8 hours. A polymer was synthesized. The average degree of polymerization of the siloxane repeating unit of the obtained silicone polymer was 18. 25 parts of this polymer solution was blended with the epoxy resin composition used in Example 1 in terms of solid content to prepare a varnish.

(Example 3)
As in Example 1, 20 g of dimethoxydimethylsilane, 20 g of tetramethoxysilane, and 10 g of methanol were mixed with 0.29 g of acetic acid and 15.5 g of distilled water, and then stirred at 50 ° C. for 8 hours. A polymer was synthesized. The average degree of polymerization of the siloxane repeating unit of the obtained silicone polymer was 24. 25 parts of this polymer solution was blended with the epoxy resin composition used in Example 1 in terms of solid content to prepare a varnish.

Example 4
As in Example 1, 0.31 g of acetic acid and 14 g of distilled water were added to a solution containing 20 g of dimethoxydimethylsilane, 20 g of trimethoxymethylsilane, and 10 g of methanol, and then stirred at 50 ° C. for 8 hours. A coalescence was synthesized. The average polymerization degree of the siloxane repeating unit of the obtained silicone polymer was 20. 25 parts of this polymer solution was blended with the epoxy resin composition used in Example 1 in terms of solid content to prepare a varnish.

(Example 5)
As in Example 1, 0.32 g of acetic acid and 13 g of distilled water were added to a solution containing 30 g of dimethoxydimethylsilane, 10 g of trimethoxymethylsilane, and 10 g of methanol, and then stirred at 50 ° C. for 8 hours. A coalescence was synthesized. The average degree of polymerization of siloxane repeating units of the obtained silicone polymer was 11. 25 parts of this polymer solution was blended with the epoxy resin composition used in Example 1 in terms of solid content to prepare a varnish.

(Example 6)
In the same manner as in Example 1, 20 g of dimethoxydimethylsilane, 10 g of trimethoxymethylsilane, 10 g of tetramethoxysilane, and 10 g of methanol were mixed with 0.15 g of acetic acid and 14.8 g of distilled water. Was stirred for 8 hours to synthesize a silicone polymer. The average degree of polymerization of the siloxane repeating unit of the obtained silicone polymer was 25. 25 parts of this polymer solution was blended with the epoxy resin composition used in Example 1 in terms of solid content to prepare a varnish.

(Example 7)
In the silicone polymer solution obtained in Example 2, γ-glycidoxypropyltrimethoxysilane (manufactured by Nihon Unicar Co., Ltd., trade name: A-187) as a silane coupling agent (CP) was used in a mass ratio. Silicone polymer: A-187 was blended so as to be 50:50. 25 parts of this solution was blended with the epoxy resin composition used in Example 1 in terms of solid content to prepare a varnish.

(Example 8)
The silicone polymer solution obtained in Example 2 was blended in the epoxy resin composition used in Example 1 with 12 parts in terms of solid content to prepare a varnish.

Example 9
150 parts of the silicone polymer solution obtained in Example 2 was blended with the epoxy resin composition used in Example 1 in terms of solid content, and further 5 parts of methyl ethyl ketone was blended to prepare a varnish.

(Example 10)
A silicone polymer was synthesized in the same manner as in Example 3 except that the stirring time was changed from 8 hours to 24 hours. The average degree of polymerization of the siloxane repeating unit of the obtained silicone polymer was 98. 25 parts of this polymer solution was blended with the epoxy resin composition used in Example 1 in terms of solid content to prepare a varnish.

(Example 11)
The silicone polymer solution obtained in Example 2 was blended with 25 parts of the following epoxy resin composition in terms of solid content to prepare a varnish.
Cresol novolak type epoxy resin (manufactured by Sumitomo Chemical Co., Ltd., trade name: ESCN-195, epoxy equivalent 195) 100 parts, dicyandiamide (manufactured by Nippon Carbide Corporation, active hydrogen group equivalent 21) 6 parts, 2-ethyl- An epoxy resin composition is prepared by mixing 0.5 part of 4-methylimidazole and 35 parts of methyl ethyl ketone.

(Comparative Example 1)
The epoxy resin composition obtained in Example 1 was used as it was.

(Comparative Example 2)
The epoxy resin composition obtained in Example 11 was used as it was.

(Comparative Example 3)
In a glass flask equipped with a stirrer, a condenser and a thermometer, 40 g of tetramethoxysilane and 93 g of methanol were mixed with 0.47 g of acetic acid and 18.9 g of distilled water, and then stirred at 50 ° C. for 8 hours. Silicone oligomers were synthesized. The average degree of polymerization of the siloxane repeating unit of the obtained silicone oligomer was 20. 25 parts of this polymer solution was blended with the epoxy resin composition used in Example 1 in terms of solid content to prepare a varnish.

(Comparative Example 4)
In the same manner as in Example 1, a solution containing 40 g of trimethoxymethylsilane and 93 g of methanol was mixed with 0.53 g of acetic acid and 15.8 g of distilled water, and then stirred at 50 ° C. for 8 hours to synthesize a silicone oligomer. The average degree of polymerization of siloxane repeating units of the obtained silicone oligomer was 15. 25 parts of this polymer solution was blended with the epoxy resin composition used in Example 1 in terms of solid content to prepare a varnish.

(Comparative Example 5)
As in Example 1, 20 g of trimethoxymethylsilane, 22 g of tetramethoxysilane, and 98 g of methanol were mixed with 0.52 g of acetic acid and 18.3 g of distilled water, and then stirred at 50 ° C. for 8 hours. Silicone oligomers were synthesized. The average degree of polymerization of the siloxane repeating unit of the obtained silicone oligomer was 25. 25 parts of this polymer solution was blended with the epoxy resin composition used in Example 1 in terms of solid content to prepare a varnish.

(Comparative Example 6)
Epoxy resin using γ-glycidoxypropyltrimethoxysilane (manufactured by Nippon Unicar Co., Ltd., trade name: A-187) as a silane coupling agent (CP) instead of the silicone polymer solution in Example 1 A varnish was prepared by blending 25 parts of the composition in terms of solid content.

(Comparative Example 7)
In place of the silicone polymer solution, 25 parts of silicone rubber powder (SRP) (manufactured by Toray Dow Corning Silicone Co., Ltd., trade name: Trefil E601) in the epoxy resin composition used in Example 1 in terms of solid content is blended. A varnish was prepared.

  The varnishes produced in Examples 1 to 11 and Comparative Examples 1 to 7 were applied to a polyethylene terephthalate (PET) film having a thickness of about 0.1 mm, heated at 150 ° C. for 5 minutes and dried, and then the obtained resin was PET. A B-stage resin powder was obtained by demulsifying from the film. Put the required amount of this resin powder in a 1.6 mm thick spacer, and stack 18 μm thick copper foil on both sides with the glossy surface inside, press at 170 ° C. for 90 minutes at 4.0 MPa, The resin plate was produced by peeling off.

The obtained resin plate was measured for dynamic viscoelasticity by the following method, and the results are shown in Table 1.
(Measurement of dynamic viscoelasticity)
Using a rheometer as a viscoelasticity measuring instrument, model name: RSA-II, raising the temperature from 25 ° C to 250 ° C (heating rate: 10 ° C / min), setting the span distance to 6 mm, and in the tension mode It was measured. The test piece size was 5 mm × 20 mm. The storage elastic modulus at 50 ° C. and 200 ° C. was obtained from the obtained viscoelastic curve, and Tg was obtained from the maximum value of tan δ.

From Table 1, the following is clear.
The compositions according to Examples 1 to 11 are almost reduced in elastic modulus at Tg and 25 ° C. as compared with the composition according to Comparative Example 1 and the composition according to Comparative Example 2 in which no silicone polymer is blended. The elastic modulus at 200 ° C. was reduced. On the other hand, the compositions according to Comparative Examples 3 to 6 had higher Tg than the composition according to Comparative Example 1, but the elastic modulus at 200 ° C. was increased. Although the composition according to Comparative Example 7 also increased in Tg, the elastic modulus in all temperature ranges was significantly reduced. From the above, it can be seen that the compositions according to the examples have an elastic modulus at 200 ° C. of 100 MPa or less and exhibit excellent toughness at high temperatures.

Claims (20)

  A thermosetting resin composition, wherein the cured product has a storage elastic modulus at 25 ° C of 1.0 GPa or more and a storage elastic modulus at 200 ° C of 100 MPa or less.   A thermosetting resin composition comprising an epoxy resin and a curing agent as essential components, and a cured elastic modulus at 200 ° C. of 100 MPa or less.   The thermosetting resin composition according to claim 1, wherein the cured product has a glass transition temperature of 170 ° C. or higher. A silicone polymer having a bifunctional siloxane unit represented by the formula R ₂ SiO _2/2 (wherein R is the same or different organic group) in the molecule. 4. The thermosetting resin composition according to any one of 3 above.   The thermosetting resin composition according to claim 4, comprising 2 parts by mass or more of a silicone polymer with respect to 100 parts by mass of the epoxy resin. (A) an epoxy resin, (b) a curing agent, and (c) a bifunctional siloxane unit represented by the formula R ₂ SiO _2/2 (wherein R is the same or different organic group) in the molecule. A thermosetting resin composition comprising a silicone polymer as an essential component.   The thermosetting resin composition according to claim 6, wherein the curing agent (b) is a phenol resin. The silicone polymer of (c) has a bifunctional siloxane unit represented by the formula R ₂ SiO _2/2 (wherein R is the same or different organic group) in the molecule and the formula RSiO _3/2 (wherein , R are the same or different organic groups.) The thermosetting resin composition of Claim 6 or 7 containing the trifunctional siloxane unit shown by these. The silicone polymer of (c) has a bifunctional siloxane unit represented by the formula R ₂ SiO _2/2 (wherein R is the same or different organic group) and a formula SiO _4/2 in the molecule. The thermosetting resin composition of Claim 6 or 7 containing a tetrafunctional siloxane unit. The silicone polymer of (c) is a bifunctional siloxane unit represented by the formula R ₂ SiO _2/2 (wherein R is the same or different organic group) in the molecule, the formula RSiO _3/2 (wherein , R are the same or different organic groups.) And a tetrafunctional siloxane unit represented by the formula SiO _4/2 and a thermosetting resin composition according to claim 6 or 7. object.   The thermosetting resin composition according to any one of claims 6 to 10, wherein the bifunctional siloxane unit contained in the molecule of the silicone polymer (c) is 10 mol% or more of the whole silicone polymer. .   The thermosetting resin composition according to any one of claims 6 to 11, wherein the average degree of polymerization of the silicone polymer of (c) is 2 to 2,000.   The thermosetting resin composition according to any one of claims 6 to 12, wherein the amount of the silicone polymer (c) is 2% by mass or more based on the epoxy resin.   The thermosetting resin composition according to any one of claims 6 to 13, wherein at least one terminal of the silicone polymer of (c) is a silanol group or an alkoxy group.   The thermosetting resin composition according to any one of claims 6 to 14, further comprising a coupling agent.   The thermosetting resin according to any one of claims 6 to 15, wherein the silicone polymer (c) contains a monomer of a bifunctional silane compound, a trifunctional silane compound, or a tetrafunctional silane compound. Composition.   The silicone polymer of (c) is a single oligomer of one compound selected from a bifunctional silane compound, a trifunctional silane compound and a tetrafunctional silane compound or a composite oligomer of two or more compounds thereof. The thermosetting resin composition according to any one of claims 6 to 16, which is mixed.   The said (a) component, (b) component, and (c) component are mix | blended simultaneously, The manufacturing method of the thermosetting resin composition of any one of Claims 6-17 characterized by the above-mentioned.   The thermosetting resin composition according to any one of claims 6 to 17, wherein the component (a), the component (b) and the component (c) are blended and stirred simultaneously in the presence of a solvent. Manufacturing method.   The silicone polymer of (c) is characterized in that a solution obtained by oligomerizing a bifunctional silane compound and a mixture of a trifunctional silane compound and / or a tetrafunctional silane compound in the presence of a catalyst is used as it is. Item 18. A method for producing a thermosetting resin composition according to any one of Items 6 to 17.