JP2006199742A - Epoxy resin composition and its cured product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epoxy resin composition which reduces foaming on preparing the composition and curing and can obtain a cured product having good mechanical strength and heat resistance, and its cured product. <P>SOLUTION: The epoxy resin composition comprises a compound (A) having a glycidyl group (x1) and an acetal group (x2) in the molecule, a liquid epoxy resin (B) other than the compound (A), and a curing agent (C), and the content of the compound (A) is 0.1-5 pts.wt. based on 100 pts.wt. sum of the liquid epoxy resin (B) and the curing agent (C). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to an epoxy resin composition and a cured product thereof that can yield a cured product with little mechanical foaming and good heat resistance during composition preparation and curing.

  Conventionally, cured products obtained by curing epoxy resins are widely used as electrical and electronic insulation materials, paints, adhesives, casting materials, etc. because of their excellent heat resistance, electrical properties, mechanical properties, etc. ing. In these applications, the time required for defoaming is reduced by suppressing foaming during preparation of the composition by reducing costs by shortening the manufacturing process, and by increasing the quality of the cured product. Promptly proceed to the curing process, suppress the occurrence of voids and sink marks, which are structural defects of the cured product, and obtain a cured product with excellent homogeneity, that is, excellent mechanical properties inherent to the cured epoxy resin product It is important to be able to sufficiently develop strength and heat resistance.

  In response to these requirements, for example, a technique using an acrylic antifoaming agent has been proposed (see, for example, Patent Document 1). However, when an additive such as an acrylic antifoaming agent is used in combination, it has an effect of suppressing foaming at the time of preparing the epoxy resin composition and an effect of suppressing the occurrence of voids and sink marks of the cured product, but those on the surface of the obtained cured product. The additive may bleed out and impair the appearance, adversely affect the processing process after obtaining the cured product, and may reduce the mechanical strength of the cured product itself. It has not yet been resolved.

JP 2000-178415 A (page 3)

  In view of the above circumstances, the object of the present invention is to provide an epoxy resin composition and a cured product thereof, which can obtain a cured product with less mechanical foaming and good heat resistance when the composition is prepared or cured. There is to do.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have determined that a compound having a glycidyl group and an acetal group in one molecule is a total of 100 parts by weight of a liquid epoxy resin other than the compound and a curing agent. It was found that the epoxy resin composition containing 0.1 to 5 parts by weight has less foaming at the time of preparation and curing, and the cured product obtained has good mechanical strength and heat resistance. Completed.

  That is, the present invention comprises a compound (A) having a glycidyl group (x1) and an acetal group (x2) in one molecule, a liquid epoxy resin (B) other than the compound (A), and a curing agent (C). And the content of the compound (A) is 0.1 to 5 parts by weight with respect to a total of 100 parts by weight of the liquid epoxy resin (B) and the curing agent (C). And a cured product thereof.

  By using the epoxy resin composition of the present invention, without impairing the excellent mechanical strength and heat resistance of the cured product obtained in the epoxy resin / curing agent system, there is little foaming at the time of preparing the composition (during mixing), In addition to shortening the defoaming step, the occurrence of voids and sink marks in the cured product can be suppressed, and a cured product having excellent homogeneity can be provided. The epoxy resin composition of the present invention can be suitably used particularly for applications such as casting and heat molding, and since there is no bleed out on the surface of the resulting cured product, it can be used in subsequent processing steps. It has no industrial influence and has no influence.

  The compound (A) used in the present invention has a glycidyl group (x1) and an acetal group (x2) in one molecule. The glycidyl group (x1) and the acetal group (x2) are represented by the following structural formulas (3) and (4).

（式中、Ｒは水素原子又は炭素数１〜４のアルキル基である。）
で表されるものである。グリシジル基（ｘ１）は、後述する硬化剤（Ｃ）と反応することが可能であり、前記化合物（Ａ）が硬化後に表面にブリードアウトすることを防止するとともに、架橋構造中に組み込まれることから、得られる硬化物の機械的強度や耐熱性に対する悪影響を防止するために必須の官能基である。また、前記アセタール基（ｘ２）は後述する液状エポキシ樹脂（Ｂ）と硬化剤（Ｃ）とを均一に混合する際の発泡を抑制し、且つ硬化物の構造欠陥であるボイドやヒケ等の発生を抑制する効果を発現させるために必要な官能基である。このような官能基を有する化合物（Ａ）をエポキシ樹脂組成物中に配合することによって、組成物調製時（混合時）の発泡が少なく、脱泡工程を短縮できると共に、硬化物には構造欠陥の発生も抑えられ、均質性に優れた機械的強度・耐熱性が良好な硬化物が得られるものである。

(In the formula, R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.)
It is represented by The glycidyl group (x1) can react with the curing agent (C) described later, and prevents the compound (A) from bleeding out to the surface after curing, and is incorporated into the crosslinked structure. This is an essential functional group for preventing adverse effects on the mechanical strength and heat resistance of the resulting cured product. The acetal group (x2) suppresses foaming when the liquid epoxy resin (B) and the curing agent (C) described later are mixed uniformly, and generation of voids and sink marks, which are structural defects of the cured product. It is a functional group necessary for expressing the effect of suppressing the above. By blending the compound (A) having such a functional group into the epoxy resin composition, foaming during composition preparation (during mixing) can be reduced and the defoaming process can be shortened. Generation | occurrence | production of generation | occurrence | production is also suppressed and the hardened | cured material with favorable mechanical strength and heat resistance excellent in the homogeneity is obtained.

  In order for the compound (A) to exhibit the effects as described above, the amount of the compound (A) is 0.1 to 5 wt. It is necessary to be a part. If the blending amount is less than 0.1 parts by weight, the effect of suppressing foaming is insufficient, and even if it is used in excess of 5 parts by weight, there is no difference in the defoaming effect, and the cost increases, which is not industrially suitable.

  The compound (A) preferably has a polyoxyalkylene structure (x3) other than the acetal group (x2) because it exhibits a further foaming suppression effect. Among the polyoxyalkylene structures (x3), a polyoxyalkylene structure having 2 to 4 carbon atoms is preferable from the viewpoint of excellent defoaming effect. Moreover, when the repeating unit of the polyoxyalkylene structure (x3) is increased, the mechanical strength may be decreased due to a decrease in the crosslinking density of the obtained cured product, and therefore, the preferable number of repeating units is 2 to 5.

  Examples of the compound (A) include the following general formula (1)

（式中、Ｒは水素原子、又は炭素数１〜４のアルキル基であり、Ｘは２価の有機基を表す。）
で表される化合物、又は下記一般式（２）

(In the formula, R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and X represents a divalent organic group.)
Or a compound represented by the following general formula (2)

（式中、Ｒは水素原子、又は炭素数１〜４のアルキル基であり、Ｘは２価の有機基であり、Ｒ_１、Ｒ_２は同一でも異なっていても良い水素原子又はメチル基である。）
で表される化合物が挙げられ、単独でも、２種以上の化合物を併用して用いても良い。

(In the formula, R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, X is a divalent organic group, and R ₁ and R ₂ are the same or different hydrogen atom or methyl group. is there.)
And may be used alone or in combination of two or more compounds.

  Among these, as described above, the divalent organic group X in the formulas (1) and (2) is preferably a polyoxyalkylene structure (x3). (Ethyleneoxy) ethyl group, tri (ethyleneoxy) ethyl group, propyleneoxypropyl group, di (propyleneoxy) propyl group, tri (propyleneoxy) propyl group, butyleneoxybutyl group, di (butyleneoxy) butyl group or tri A (butyleneoxy) butyl group is preferred. When these preferred compounds are used, the defoaming effect is high, so the blending amount is 0.3 to 2 with respect to a total of 100 parts by weight of the liquid epoxy resin (B) and the curing agent (C) described later. It is preferable that it is a weight part. Further, R in the general formulas (1) and (2) is preferably a hydrogen atom from the viewpoint of easy availability of raw materials, and R1 and R2 in the general formula (2) are obtained curings. A methyl group is preferred from the viewpoint of less reducing the mechanical strength of the product.

  The method for producing the compound (A) is not particularly limited. For example, examples of the method for producing the compound represented by the general formula (1) include a production method by acetalization reaction of divinyl ethers and glycidols.

  The acetalization reaction is an addition reaction between a vinyl ether group in divinyl ethers and a hydroxyl group in glycidols.

で表されるものである。

It is represented by

  Examples of the divinyl ethers include, but are not limited to, ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, tetraethylene glycol divinyl ether, propylene glycol divinyl ether, dipropylene glycol divinyl ether, and tripropylene. Divinyl ethers containing a polyoxyalkylene structure such as glycol divinyl ether, tetrapropylene glycol divinyl ether, dibutylene glycol divinyl ether, tributylene glycol divinyl ether, tetrabutylene glycol divinyl ether; 1,3-butanediol divinyl ether; 1,4-butanedidiol divinyl ether, 1,6-hexane Divinyl ethers having an alkylene chain, such as all divinyl ether, 1,9-nonanediol divinyl ether, 1,10-decanediol divinyl ether, neopentyl glycol divinyl ether, and hydroxypivalic acid neopentyl glycol divinyl ether; 1,4- Cycloalkane structures such as cyclohexanediol divinyl ether, 1,4-cyclohexanedimethanol divinyl ether, tricyclodecane diol divinyl ether, tricyclodecane dimethanol divinyl ether, pentacyclopentadecane dimethanol divinyl ether, pentacyclopentadecane diol divinyl ether Divinyl ethers contained: bisphenol A divinyl ether, ethylene oxide modified bisphenol A di Nyl ether, propylene oxide modified bisphenol A divinyl ether, bisphenol F divinyl ether, ethylene oxide modified bisphenol F divinyl ether, divinyl ethers such as propylene oxide modified bisphenol F divinyl ether, etc., alone or as a mixture of two or more Can also be used.

  Among these, it is preferable to use divinyl ethers containing a polyoxyalkylene structure from the viewpoint of obtaining a compound having a polyoxyalkylene structure (x3) as described above.

  Examples of the glycidol include glycidol having an epoxy group and a hydroxyl group, and β-position methyl group-substituted glycidol. In view of industrial availability and economy, it is preferable to use glycidol.

  The reaction between the divinyl ethers and glycidols will be described. Examples of the reaction method include a method in which divinyl ethers and glycidols are charged and heated while stirring and mixing. In this case, an organic solvent and a catalyst can be used as needed. The organic solvent that can be used is not particularly limited, and examples thereof include aromatic organic solvents such as benzene, toluene, and xylene, and ketone organic solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. It can be selected as appropriate in consideration of properties such as the raw materials used and the solubility of the product, reaction conditions, economics, and the like. The amount of the organic solvent is preferably 5 to 500% by weight based on the raw material weight.

  Further, as the catalyst, the reaction usually proceeds even in a non-catalytic system, but it is preferable to use a catalyst in order to increase the reaction rate or advance the reaction under a low temperature condition that prevents the self-polymerization of glycidol. Examples of the catalyst include inorganic acids such as sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, acidic phosphoric esters, toluenesulfonic acid, methanesulfonic acid, xylenesulfonic acid, trifluoromethanesulfonic acid, oxalic acid, formic acid, trichloroacetic acid, Lewis acids such as organic acids such as trifluoroacetic acid, aluminum chloride, iron chloride, tin chloride, gallium chloride, titanium chloride, aluminum bromide, gallium bromide, boron trifluoride ether complex, boron trifluoride phenol complex, etc. As an addition amount, it can be used in the range of 10 ppm to 5 wt% with respect to the total weight of the raw material. Among these, acidic phosphates are particularly preferable from the viewpoints of good reaction rate and few side reactions.

  The reaction conditions for the divinyl ethers and glycidols are usually room temperature to 150 ° C., preferably 20 to 100 ° C., and may be heated and stirred for about 0.5 to 30 hours. The progress of the reaction can be traced by measuring the residual amount of the raw material using gas chromatography, liquid chromatography, GPC or the like. In addition, when an organic solvent is used, it is removed by distillation or the like after completion of the reaction, and when a catalyst is used, it is preferably deactivated with a deactivator or the like as necessary, and then removed by washing with water or filtering. .

  The reaction ratio of divinyl ethers and glycidols in the above reaction is not particularly limited, but from the point that a desired compound can be obtained efficiently, vinyl ether group / glycidol group = 100/80 to 100/150 (molar ratio). It is preferable to make it react on such preparation conditions.

  In addition, as a method for producing the compound represented by the general formula (2), for example, the divinyl ethers and bisphenols described in JP-A No. 2004-156024 can be combined with the acetalization reaction described above. A method of reacting in the same manner to obtain a modified bisphenol and then reacting with epihalohydrin to convert the hydroxyl group to glycidyl ether can be mentioned.

  Examples of the divinyl ethers that can be used at this time include all of the above-mentioned ones. Examples of bisphenols include bis (4-hydroxyphenyl) methane (bisphenol F), 2,2-bis (4-hydroxyphenyl) propane (bisphenol A), and 2,2-bis (3-methyl-4). -Hydroxyphenyl) propane (bisphenol C), 1,1-bis (4-hydroxyphenyl) cyclohexane (bisphenol Z), 1,1-bis (4-hydroxyphenyl) -1-phenylethane (bisphenol AP), and these These can be used alone or as a mixture of two or more. Among these, it is particularly preferable to use bisphenol A because it is easy to obtain raw materials and does not lower the mechanical strength of the resulting cured product.

  The reaction method between the divinyl ethers and the bisphenols is the same as the reaction method with the glycidols described above. However, in the catalyst addition system, it is necessary to select the type, addition amount, and reaction conditions so as not to cause a vinyl group nucleus addition reaction to the aromatic ring.

  The reaction ratio of vinyl ethers and bisphenols in the above reaction is not particularly limited as long as at least one aromatic hydroxyl group remains in one molecule of the reaction product. Preferred ratio is such that it is 80/20 to 50/50 (molar ratio) / [vinyl ether group of divinyl ether] = 80/20 to 50/50 (molar ratio).

  Next, the method for glycidyl etherification of the resulting modified bisphenol will be described in detail. The method is not particularly limited. For example, an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is added to a solution obtained by mixing the modified bisphenol obtained above and an epihalohydrin such as epichlorohydrin or epibromohydrin. The method of making it react for 1 to 10 hours at 20-120 degreeC is added, adding a thing. The added amount of epihalohydrin is usually in the range of 0.3 to 20 equivalents with respect to 1 equivalent of hydroxyl group in the raw material modified bisphenol. The epihalohydrin used here is preferably epichlorohydrin because it is easily available.

  As the alkali metal hydroxide, an aqueous solution thereof may be used. In that case, the aqueous solution of the alkali metal hydroxide is continuously added to the reaction system, and water and epihalohydrin are continuously added under reduced pressure or normal pressure. May be distilled off, and the liquid may be further separated to remove water and the epihalohydrin to be continuously returned to the reaction system.

  Further, it is obtained by adding a quaternary ammonium salt such as tetramethylammonium chloride, tetramethylammonium bromide, trimethylbenzylammonium chloride as a catalyst to a dissolved mixture of modified bisphenols and epihalohydrin and reacting at 50 to 150 ° C. for 1 to 5 hours. A method of adding a solid or aqueous solution of an alkali metal hydroxide to the halohydrin etherified product of phenols and reacting again at 20 to 120 ° C. for 1 to 10 hours to dehydrohalogenate (ring closure) may be used.

  Furthermore, alcohols such as methanol, ethanol, isopropyl alcohol and butanol, ketones such as acetone and methyl ethyl ketone, ethers such as dioxane, aprotic polar solvents such as dimethyl sulfone and dimethyl sulfoxide, etc. are used in order to facilitate the reaction. It is preferable to carry out the reaction by adding. The amount of the solvent used is usually 5 to 50% by weight, preferably 10 to 30% by weight, based on the amount of epihalohydrin. Moreover, when using an aprotic polar solvent, it is 5-100 weight% normally with respect to the quantity of epihalohydrin, Preferably it is 10-60 weight%.

  After the epoxidation reaction product is washed with water or without washing with water, epihalohydrin and other added solvents are removed at 110 to 250 ° C. under a pressure of 10 mmHg or less under reduced pressure. In order to further reduce the hydrolyzable halogen compound, the crude compound obtained after recovering the epihalohydrin or the like is dissolved again in a solvent such as toluene or methyl isobutyl ketone, and alkali metal water such as sodium hydroxide or potassium hydroxide is dissolved. An aqueous solution of the oxide can be added to further react to ensure ring closure. In this case, the usage-amount of an alkali metal hydroxide is 0.5-10 mol normally with respect to 1 mol of hydrolyzable chlorine which remains in a crude compound, Preferably it is 1.2-5.0 mol. The reaction temperature is usually 50 to 120 ° C., and the reaction time is usually 0.5 to 3 hours. For the purpose of improving the reaction rate, a phase transfer catalyst such as a quaternary ammonium salt or crown ether may be present. When the phase transfer catalyst is used, the amount used is preferably in the range of 0.1 to 3.0% by weight based on the crude compound.

  After completion of the reaction, the produced salt is removed by filtration, washing with water, and the target compound (A) can be obtained by distilling off a solvent such as toluene and methyl isobutyl ketone under heating and reduced pressure.

  Of course, it is also possible to use a rational means such as preparing modified bisphenols and charging raw materials such as epihalohydrins as they are and continuously converting them to glycidyl ether without taking them out of the reactor.

  The liquid epoxy resin (B) used in the present invention is not particularly limited as its structure, and various types can be used, for example, bisphenol A type liquid epoxy resin, bisphenol F type liquid epoxy resin, etc. Bisphenol type epoxy resins, biscyclic epoxy resins such as hydrogenated bisphenol A type liquid epoxy resins, dihydroxynaphthalene type epoxy resins, divalent phenol type epoxy resins such as epoxy resins derived from tertiary butylcatechol and epihalohydrin, Reactivity of monoepoxy compounds from monohydric phenols, alcohol ether type epoxy resins composed of monohydric or polyhydric alcohols such as neopentyl glycol, trimethylolpropane, 1,6-hexanediol, 1,4-butanediol Called diluent Shall the like, alone, may be used as a mixture of two or more. Among these, it is preferable to contain a bisphenol-type liquid epoxy resin from the viewpoint of excellent mechanical properties and heat resistance of the obtained cured product and easy industrial availability.

  Moreover, as a liquid epoxy resin (B) used for this invention, in the range which does not impair the effect of this invention, various solid epoxy resins etc. are used together, it heat-mixes and liquefies, and it may be used also as a liquid epoxy resin. good.

  Various curing agents (C) used in the present invention can be used, and are not particularly limited. For example, curing agents such as amine compounds, acid anhydride compounds, and phenol compounds can be used. For example, as amine compounds, ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, pentaethylenehexamine, metaxylylenediamine, diaminodiphenylmethane, phenylenediamine, 1,3-bis (aminomethyl) Polyamines such as cyclohexane, isophorone diamine, norbornane diamine, etc., polyamide resins obtained by reacting the above polyamines with carboxylic acids such as monomer acids and dimer acids and the like, and polycondensates of the above polyamines, phenols and formaldehyde. Examples include Mannich type curing agents.

  Examples of the acid anhydride compound include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methyl nadic anhydride, hexahydrophthalic anhydride. And methyl hexahydrophthalic anhydride.

Examples of phenolic compounds include phenol novolac resins, cresol novolac resins, aromatic hydrocarbon formaldehyde resin-modified phenol resins, dicyclopentadiene phenol addition resins, phenol aralkyl resins, naphthol aralkyl resins, trimethylol methane resins, tetraphenylols. Examples include ethane resins, naphthol novolak resins, naphthol-phenol co-condensed novolak resins, naphthol-cresol co-condensed novolak resins, biphenyl-modified phenol resins, aminotriazine-modified phenol resins, and modified products thereof. Examples of latent catalysts include imidazole, BF ₃ -amine complexes, guanidine derivatives, and the like.

  Further, these amine compounds, acid anhydride compounds, phenol compounds and the like curing agents may be used alone or in combination of two or more.

  Among the above-mentioned various curing agents, an amine compound or an acid anhydride compound is obtained because an epoxy resin composition having fluidity and excellent workability and an excellent adhesiveness of the obtained cured product can be obtained. It is preferable to use, and it is preferable to use an acid anhydride type compound from the point that the hardened | cured material with thickness is obtained by casting and the effect of this invention is remarkable.

  In the epoxy resin composition of the present invention, the amount of the curing agent (C) used is that the curing proceeds smoothly and good physical properties of the cured product are obtained, so that the compound (A) and the liquid epoxy resin (B The amount of active hydrogen groups in the curing agent (C) is preferably 0.7 to 1.3 equivalents with respect to a total of 1 equivalent of epoxy groups.

  Moreover, a hardening accelerator can also be further used for the epoxy resin composition of this invention suitably. Various curing accelerators can be used, and examples thereof include phosphorus compounds, tertiary amines, imidazoles, organic acid metal salts, Lewis acids, amine complex salts, and the like. Can be used in combination.

  An inorganic filler can be blended in the epoxy resin composition of the present invention. Examples of the inorganic filler include fused silica, crystalline silica, alumina, silicon nitride, and aluminum hydroxide.

  Furthermore, various compounding agents, such as a silane coupling agent, a mold release agent, a pigment, an emulsifier, can be added to the epoxy resin composition of this invention as needed.

  An organic solvent can be used for the epoxy resin composition of this invention as needed. The organic solvent is used to lower the viscosity and improve the fluidity and moldability, and the type is not particularly limited. Illustrative examples include methanol, toluene, xylene, diethyl ether, acetone, methyl ethyl ketone, dimethylformamide and the like. As the amount used, it is preferable that the solid content value of the epoxy resin composition is in the range of 20 to 95% by weight.

  The epoxy resin composition of the present invention comprises the compound (A), the liquid epoxy resin (B), the curing agent (C), and other additives, curing accelerators, fillers, and the like, if necessary. It can obtain by mixing uniformly using the stirring method according to a viscosity. At this time, the compound (A) is preferably added to the liquid epoxy resin (B). Further, the liquid epoxy resin (B) and the curing agent (C) may be added after being mixed in advance.

  When a filler or various additives are used in combination, an epoxy resin composition is prepared by mixing the additives in one of the liquid epoxy resin (B) or the curing agent (C) in advance and preparing a so-called master batch. The method which makes it a thing is preferable.

  The epoxy resin composition of the present invention suppresses foaming at the time of stirring and mixing, and rapidly defoams even under normal pressure, but generation of voids, sink marks, etc. that are structural defects of the resulting cured product In order to suppress further, it is preferable to prepare the resin composition, leave it under reduced pressure, and gradually restore the pressure using an inert gas.

  The use of the epoxy resin composition of the present invention is not particularly limited, and examples thereof include a sealing material for electrical and electronic parts, a conductive paste, a resin casting material, an adhesive, and a coating material. Among these, it can use suitably as a molding epoxy resin composition (resin casting material) which obtains a molding by casting.

  The cured product of the present invention can be easily obtained by curing the epoxy resin composition obtained above. The curing method is not particularly limited, and a method according to the type of the curing agent (C) and the curing accelerator may be used. In particular, when obtaining a molded cured product, various materials, for example, A mold pre-made with tempered glass or metal is uniformly stirred and mixed, and the defoamed molding epoxy resin composition is poured (casting) and heated and cured as it is, pre-cured in the mold. And a method of post-curing after demolding.

  EXAMPLES The present invention will be described in detail below by examples, but the present invention is not limited to these examples. In the examples, unless otherwise specified, “parts” and “%” are based on weight.

  Synthesis Example 1 Synthesis of Compound (A-1) Represented by Structural Formula (I) below

A flask equipped with a thermometer and a stirrer was charged with 202 g of triethylene glycol divinyl ether (manufactured by ISP: trade name Rapi-Cure DVE-3) and 148 g of glycidol (2,3-epoxy-1-propanol), and methylated at room temperature. 1 g of acid phosphate (manufactured by Daihachisha: trade name AP-1) was added, the temperature was raised to 70 ° C., and stirring was continued for 8 hours. After confirming the substantial disappearance of the raw material by GPC, the contents were taken out to obtain 351 g of a colorless and transparent liquid. The resin is the compound (A-1) represented by the structural formula (I) because a peak of M ⁺ = 350 corresponding to the theoretical structure was obtained from the NMR spectrum ( ¹³ C) and mass spectrum. It was confirmed. The epoxy equivalent of this resin (A-1) was 188 g / eq, and the content of the theoretical structure [structure of the structural formula (I)] measured by GPC was 71 area%.

  Synthesis Example 2 Synthesis of Compound (A-2) Represented by Structural Formula (II) below

温度計、撹拌機を取り付けたフラスコにビスフェノールＡ２２８ｇ（１．００モル）とトリエチレングリコールジビニルエーテル（ＩＳＰ社製：商品名Ｒａｐｉ−Ｃｕｒｅ ＤＶＥ−３）１７２ｇ（０．８５モル）を仕込み、１２０℃まで１時間要して昇温した後に、さらに１２０℃で６時間反応させて、透明半固形の原料樹脂（変性ビスフェノール）４００ｇを得た。これの水酸基当量は３６４ｇ／ｅｑ．であった。次いで、上記で得られた原料樹脂４００ｇ、エピクロルヒドリン９２５ｇ（１０モル）、ｎ−ブタノール１８５ｇを仕込み溶解させた。その後、窒素ガスパージを施しながら、６５℃に昇温した後に、共沸する圧力までに減圧して、４９％水酸化ナトリウム水溶液１２２ｇ（１．５モル）を５時間かけて滴下した、次いでこの条件下で０．５時間撹拌を続けた。この間、共沸で留出してきた留出分をディーンスタークトラップで分離して、水層を除去し、有機層を反応系内に戻しながら反応した。その後、未反応のエピクロルヒドリンを減圧蒸留して留去させた。それで得られた粗樹脂にメチルイソブチルケトン１０００ｇとｎ−ブタノール１００ｇを加え溶解した。更にこの溶液に１０％水酸化ナトリウム水溶液２０ｇを添加して８０℃で２時間反応させた後に洗浄液のＰＨが中性となるまで水３００ｇで水洗を３回繰り返した。次いで共沸によって系内を脱水し、精密濾過を経た後に、溶媒を減圧下で留去して、化合物（Ａ−２）を得た。これのエポキシ当量は４６２ｇ／ｅｑ、粘度は１２，０００ｍＰａ・ｓ（２５℃、キャノンフェンスケ法）、エポキシ当量から算出される上記構造式中のｎの平均値は１．３５であることが確認された。

A flask equipped with a thermometer and a stirrer was charged with 228 g (1.00 mol) of bisphenol A and 172 g (0.85 mol) of triethylene glycol divinyl ether (manufactured by ISP: trade name Rapi-Cure DVE-3) at 120 ° C. It took 1 hour until the temperature was raised, and further reacted at 120 ° C. for 6 hours to obtain 400 g of a transparent semi-solid raw material resin (modified bisphenol). Its hydroxyl equivalent is 364 g / eq. Met. Next, 400 g of the raw material resin obtained above, 925 g (10 mol) of epichlorohydrin, and 185 g of n-butanol were charged and dissolved. Then, after raising the temperature to 65 ° C. while purging with nitrogen gas, the pressure was reduced to the azeotropic pressure, and 122 g (1.5 mol) of 49% aqueous sodium hydroxide solution was added dropwise over 5 hours. Stirring was continued under 0.5 hours. During this time, the distillate distilled azeotropically was separated with a Dean-Stark trap, the aqueous layer was removed, and the reaction was conducted while returning the organic layer to the reaction system. Thereafter, unreacted epichlorohydrin was distilled off under reduced pressure. Then, 1000 g of methyl isobutyl ketone and 100 g of n-butanol were added to the resulting crude resin and dissolved. Further, 20 g of a 10% aqueous sodium hydroxide solution was added to this solution and reacted at 80 ° C. for 2 hours. Then, washing with 300 g of water was repeated three times until the pH of the washing solution became neutral. Subsequently, the system was dehydrated by azeotropic distillation, and after passing through microfiltration, the solvent was distilled off under reduced pressure to obtain Compound (A-2). The epoxy equivalent of this was 462 g / eq, the viscosity was 12,000 mPa · s (25 ° C., Canon Fenske method), and the average value of n in the above structural formula calculated from the epoxy equivalent was 1.35. It was done.

Synthesis Example 3 Synthesis of Compound (A-3) A raw material resin was obtained in the same manner as in Synthesis Example 2 except that in Synthesis Example 2, the amount of triethylene glycol divinyl ether (DVE-3) was changed to 192 g. The raw material resin has a hydroxyl group equivalent of 423 g / eq. Met. Next, 688 g of compound (A-3) was obtained in the same manner as in Synthesis Example 2 except that 615 g of this raw material resin was used. Moreover, the epoxy equivalent of this is 526 g / eq, the viscosity is 4,700 mPa · s (25 ° C., Canon Fenske method), and the average value of n in the above structural formula calculated from the epoxy equivalent is 1.65. confirmed.

Example 1
92 g of bisphenol A type liquid epoxy resin EPICLON 850 (Dainippon Ink Chemical Co., Ltd., epoxy equivalent 188 g / eq), bisphenol F type liquid epoxy resin EPICLON 830 (Dainippon Ink Chemical Co., Ltd., epoxy equivalent 170 g / eq) 38 g, reactive diluent EPICLON 726 (manufactured by Dainippon Ink & Chemicals, Inc., epoxy equivalent 154 g / eq), methyltetrahydrophthalic anhydride EPICLON B-570 (manufactured by Dainippon Ink & Chemicals, Inc.) as an acid anhydride curing agent , Acid anhydride equivalent 166 g / eq) 143 g, 2.5 g of the compound (A-1) obtained in Synthesis Example 1, 1.5 g of 1,2-dimethylimidazole in 1 liter polycup (diameter 12 cm, height 14 cm) 1) 30 minutes with a spatula Mixing for 2 seconds, an epoxy resin composition 1 was obtained. Each material used in advance was left in a constant temperature room at 25 ° C. for one day.

  Next, the polycup containing the epoxy resin composition 1 was placed in a desiccator having an internal volume of about 15 liters at 25 ° C., and vacuum defoaming was performed using a vacuum pump. The state of foaming at that time was observed, and the height from the highest liquid level of bubbles generated during the pressure reduction process and the time from the start of pressure reduction until the bubbles disappeared on the liquid level were measured.

  Next, a cured product was prepared using a glass plate (300 mm × 300 mm) subjected to a release treatment with a silicone release agent SH-7020 (manufactured by Dow Corning Toray Silicone Co., Ltd.) as a mold. First, an epoxy resin composition 1 obtained by vacuum defoaming treatment as described above was cast using a glass die having a glass rod 3 mm sandwiched between two glass plates as a mold. This was left in a drier controlled at 85 ° C. for 300 minutes, and the molded product was taken out and slowly cooled in a room temperature atmosphere to obtain a cured product for measuring physical properties having a thickness of about 3 mm. In the obtained cured product, no defects such as voids and sink marks were observed.

Example 2
The epoxy resin composition 2 was blended in the same manner as in Example 1 except that the same amount of the compound (A-2) was used instead of the compound (A-1), and the foaming status was confirmed and a cured product was prepared. Performed as in Example 1. In the obtained cured product, no defects such as voids and sink marks were observed.

Example 3
Implemented except that the same amount of compound (A-3) was used instead of compound (A-1), and 4.5 g of POLYCAT 8 (manufactured by San Apro) was used instead of 1.5 g of 1,2-dimethylimidazole. Epoxy resin composition 3 was blended in the same manner as in Example 1, and the foaming status was confirmed and the cured product was prepared in the same manner as in Example 1. In the obtained cured product, no defects such as voids and sink marks were observed.

Example 4
EPICLON 850 143.5g, EPICLON 830 60g, EPICLON 726 36g, isophoronediamine 57.5g as an amine-based curing agent, and compound (A-1) 3.0g are blended in a 1 liter polycup (diameter 12cm, height 14cm). The mixture was mixed for 1 minute 30 seconds using a spatula to obtain an epoxy resin composition 4. Each material used in advance was left in a constant temperature room at 25 ° C. for one day.

  Next, the foaming state was confirmed and a cured product was prepared in the same manner as in Example 1 except that the epoxy resin composition 4 was used. In the obtained cured product, no defects such as voids and sink marks were observed.

Example 5
The epoxy resin composition 5 was blended in the same manner as in Example 4 except that the same amount of the compound (A-2) was used instead of the compound (A-1), and the foaming status was confirmed and a cured product was prepared. Performed as in Example 1. In the obtained cured product, no defects such as voids and sink marks were observed.

Comparative Example 1
The epoxy resin composition 6 was blended in the same manner as in Example 1 except that the compound (A-1) was not used, and the foaming status was confirmed and the cured product was prepared in the same manner as in Example 1. In the resulting cured product, generation of voids was observed due to bubbles that were thought to have occurred during curing. In the following physical property tests, the voids were excluded and the test pieces were cut out.

Comparative Example 2
The epoxy resin composition 7 was blended in the same manner as in Example 1 except that 1.0 g of the non-silicone antifoaming agent BYK-A555 (manufactured by Big Chemie Japan Co., Ltd.) was used instead of the compound (A-1). Confirmation of the foaming state and production of a cured product were carried out in the same manner as in Example 1. In the obtained cured product, no defects such as voids and sink marks were observed.

Comparative Example 3
The epoxy resin composition 8 was blended in the same manner as in Example 1 except that 1.2 g of the acrylic antifoaming agent Dappo SN-348 (manufactured by San Nopco Co., Ltd.) was used instead of the compound (A-1). Confirmation and production of a cured product were performed in the same manner as in Example 1. In the obtained cured product, no defects such as voids and sink marks were observed.

Comparative Example 4
Except not using a compound (A-1), the epoxy resin composition 9 was mix | blended like Example 4, and confirmation of the foaming condition and preparation of hardened | cured material were performed like Example 1. FIG. In the resulting cured product, generation of voids was observed due to bubbles that were thought to have occurred during curing. In the following physical property tests, the voids were excluded and the test pieces were cut out.

Comparative Example 5
The epoxy resin composition 10 was blended in the same manner as in Example 4 except that 1.0 g of the non-silicone antifoaming agent BYK-A555 (manufactured by Big Chemie Japan Co., Ltd.) was used instead of the compound (A-1). The state of foaming was confirmed, and a cured product was produced. In the obtained cured product, no defects such as voids and sink marks were observed.

  Using the obtained cured product, the measurement of the heat distortion temperature, the tensile test, and the bending test were performed as follows. The results are shown in Tables 1 and 2.

Measurement method of heat distortion temperature The cured product having a thickness of about 3 mm obtained above was cut into a size of 12.5 mm × 125 mm, and according to JIS K 7207, a desktop HDT tester CU-6422P manufactured by Toyo Seiki Co., Ltd. -Measured using TS1.

Method of bending test The molded cured product having a thickness of about 3 mm obtained above was cut into a size of 25 mm x 75 mm, measured according to JIS K 6911 using an AUTOGRAPH AG-I manufactured by Shimadzu Corporation, Bending strength and flexural modulus were determined.

Tensile test method After the molded cured product having a thickness of about 3 mm obtained above was cut into a size of 180 mm × 20 mm, a test piece mold was prepared by a tensile test piece preparation machine (manufactured by Tohken Seimitsu Kogyo Co., Ltd.). According to JIS K 6911, the tensile strength and the elongation were determined by using A & D Tensilon (RTC1350A).

Claims (8)

A compound (A) having a glycidyl group (x1) and an acetal group (x2) in one molecule, a liquid epoxy resin (B) other than the compound (A), and a curing agent (C), the compound ( An epoxy resin composition, wherein the content of A) is 0.1 to 5 parts by weight with respect to 100 parts by weight of the total of the liquid epoxy resin (B) and the curing agent (C). The epoxy resin composition according to claim 1, wherein the compound (A) is a compound (a1) further having a polyoxyalkylene structure (x3) other than the acetal group (x2). The compound (A) is represented by the following general formula (1)

[Wherein, R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and X is an ethyleneoxyethyl group, a di (ethyleneoxy) ethyl group, a tri (ethyleneoxy) ethyl group, a propyleneoxypropyl group, a divalent group). (Propyleneoxy) propyl group, tri (propyleneoxy) propyl group, butyleneoxybutyl group, di (butyleneoxy) butyl group, or tri (butyleneoxy) butyl group. ]
Or a compound represented by the following general formula (2)

Wherein R and X are the same as above, R ₁ and R ₂ are the same or different hydrogen atoms or methyl groups, n is a natural number, and the average is 1.2 to 5 .)
The epoxy resin composition of Claim 2 which is a compound represented by these. The epoxy resin composition according to claim 2, wherein the content of the compound (A) is 0.3 to 2 parts by weight with respect to 100 parts by weight of the total of the liquid epoxy resin (B) and the curing agent (C). The epoxy resin composition according to claim 1, wherein the liquid epoxy resin (B) contains a bisphenol-type liquid epoxy resin. The epoxy resin composition according to claim 1, wherein the curing agent (C) is an acid anhydride compound. It is an epoxy resin composition for shaping | molding, The epoxy resin composition of any one of Claims 1-6. A cured product obtained by curing the epoxy resin composition according to any one of claims 1 to 7.