JP2017214529A - Epoxy resin, epoxy resin composition, and cured product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin having excellent transparency and UV resistance as well as excellent flexibility with a well balanced manner, while having good film-forming property, and suitable for various fields where high reliability is required, and particularly applicable for a field of optics, an epoxy resin composition comprising the epoxy resin, and a cured product obtained by curing the epoxy resin composition.SOLUTION: The epoxy resin is represented by formula (1) and has an epoxy equivalent of 200 to 30,000 g/eq. In the formula, A represents a divalent group having a structure A1 obtained by removing a hydroxyl group from polyalkylene glycol and/or hydrogenated bisphenol, or a divalent group having a structure A2 obtained by removing a hydroxyl group from bisphenol, and formula (1) includes both the structure A1 and the structure A2; R represents H or a glycidyl group and the formula includes at least one glycidyl group; and n is 1 to 500.SELECTED DRAWING: None

Description

  The present invention relates to an epoxy resin excellent in balance between transparency, UV (ultraviolet) resistance, film-forming property, and flexibility. The present invention also relates to an epoxy resin composition containing this epoxy resin and a curing agent, and a cured product obtained by curing the epoxy resin composition.

Epoxy resins are excellent in heat resistance, adhesiveness, water resistance, mechanical strength, and electrical properties, so they can be used in various fields such as adhesives, paints, civil engineering and building materials, and insulating materials for electrical and electronic parts. It is used.
In recent years, with the spread of smartphones and the like, there is a demand for materials that combine adhesiveness, film-forming properties, and UV resistance, such as adhesives that bond liquid crystal displays and touch panels, and organic EL liquid sealing materials. Various corresponding epoxy resins have been developed.

  Moreover, in order to obtain a film-like molded product, a high molecular weight epoxy resin excellent in film-forming property is used. However, a general epoxy resin has an aromatic ring structure and is easily deteriorated by light, so that transparency and UV resistance are poor and it is difficult to use in the optical field. On the other hand, although an epoxy resin having no aromatic ring structure has been developed (Patent Document 1), the reactivity is low, it is difficult to increase the molecular weight, and the film-forming property is low.

  Moreover, the epoxy resin which has an aromatic ring structure and an alicyclic ring structure is also developed (patent document 2). However, since this epoxy resin has a general aromatic skeleton, the film-forming property is good, but there is a problem that the transparency is remarkably poor and the UV resistance is poor.

  Also, an epoxy resin having an aromatic ring structure and an aliphatic structure has been developed (Patent Document 3), but the aromatic ring structure is different from the epoxy resin of the present invention, and UV resistance and film-forming properties are improved. Further improvement is desired in the balance.

JP-A-11-343286 JP 2006-176658 A JP 2010-285627 A

  The object of the present invention is to solve the above-mentioned problems and to have excellent film-forming properties, while being excellent in transparency and UV resistance, and also in excellent balance of flexibility and high reliability. An object of the present invention is to provide an epoxy resin applicable to various fields, particularly an optical field, an epoxy resin composition containing the epoxy resin, and a cured product obtained by curing the epoxy resin composition.

  As a result of intensive studies by the present inventors to solve the above-mentioned problems, the epoxy resin has an alkylene structure and / or a polyalkylene oxide structure and a chemical structure derived from a specific bisphenol in the chemical structure of the epoxy resin. However, the present invention was completed by finding that it has excellent transparency and UV resistance while having good film-forming properties, and also has excellent balance of flexibility. That is, the gist of the present invention resides in the following [1] to [15].

[1] An epoxy resin represented by the following formula (1), having an epoxy equivalent of 200 g / equivalent to 30,000 g / equivalent.

(In the formula (1), at least one of A is either a chemical structure represented by the following formula (2) or a chemical structure represented by the following formula (3) (hereinafter referred to as “chemical structure A1”). Or a divalent group having a chemical structure represented by the following formula (4) (hereinafter referred to as “chemical structure A2”). The formula (1) represents the chemical structure A1 and the chemical structure A2. R is a hydrogen atom or a group represented by the following formula (5), formula (1) includes at least one group represented by formula (5), and n is a number from 1 to 500. is there.)

(In Formula (2), R ¹ and R ² may be the same or different from each other, and are a divalent hydrocarbon group having 2 to 20 carbon atoms, and m is a number of 0 or more and 30 or less. .)

(In the formula (3), ^{R 3} is a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms, ^{R 4} is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms.)

(In Formula (4), R < ⁵ > -R < ⁸ > may mutually be same or different, and is a hydrogen atom or a C1-C6 hydrocarbon group, and R < ⁹ > is C2-C12 fat. A cyclic or aliphatic hydrocarbon group, or a halogenated hydrocarbon group having 1 to 12 carbon atoms, and R ¹⁰ is a hydrogen atom, a hydrocarbon group having 1 to 3 carbon atoms, or a halogenated carbon atom having 1 to 3 carbon atoms. It is a hydrogen group, and R ⁹ and R ¹⁰ may be bonded to each other to form a ring.)

[2] The epoxy resin according to [1], wherein the chemical structure represented by the formula (2) is included in the formula (1) in an amount of 0.1 to 100 mol% with respect to the entire chemical structure A1.

[3] The epoxy resin according to [1] or [2], wherein the molar ratio between the chemical structure A1 and the chemical structure A2 in the formula (1) is 1/99 to 99/1.

[4] The epoxy resin according to any one of [1] to [3], wherein the chemical structure represented by the formula (3) includes a hydrogenated bisphenol A type structure and / or a hydrogenated bisphenol F type structure.

[5] The epoxy resin according to any one of [1] to [4], wherein m in the formula (2) is 0.

[6] The epoxy resin according to any one of [1] to [5], which has a weight average molecular weight of 1,000 to 100,000.

[7] An epoxy resin composition comprising the epoxy resin according to any one of [1] to [6] and a curing agent.

[8] The epoxy resin composition according to [7], including 0.1 to 100 parts by weight of a curing agent with respect to 100 parts by weight of the epoxy resin.

[9] The curing agent is at least one selected from the group consisting of a phenolic curing agent, an amide curing agent, an amine curing agent, an imidazole, an acid anhydride curing agent, and an organic phosphine. [7 ] Or the epoxy resin composition according to [8].

[10] A sealing material for an electric / electronic circuit comprising the epoxy resin composition according to any one of [7] to [9].

[11] A laminate for an electric / electronic circuit comprising the epoxy resin composition according to any one of [7] to [9].

[12] An optical member comprising the epoxy resin composition according to any one of [7] to [9].

[13] An adhesive comprising the epoxy resin composition according to any one of [7] to [9].

[14] A paint comprising the epoxy resin composition according to any one of [7] to [9].

[15] A cured product obtained by curing the epoxy resin composition according to any one of [7] to [9].

  The epoxy resin of the present invention and the epoxy resin composition containing the epoxy resin give a cured product excellent in film-forming properties, transparency, UV resistance and flexibility. Therefore, the epoxy resin of the present invention and the epoxy resin composition containing the epoxy resin can be suitably used for optical materials in addition to adhesives, paints, building materials for civil engineering, insulating materials for electric / electronic parts, and the like.

  Embodiments of the present invention will be described in detail below, but the following description is an example of the embodiments of the present invention, and the present invention is limited to the following description unless it exceeds the gist. is not. In addition, when using the expression “to” in the present specification, it is used as an expression including numerical values or physical property values before and after the expression.

〔Epoxy resin〕
The epoxy resin of the present invention has an epoxy equivalent of 200 g / equivalent or more and 30,000 g / equivalent or less represented by the following formula (1).

(In formula (1), at least one of A is represented by the chemical structure represented by the following formula (2) (hereinafter sometimes referred to as “chemical structure (2)”) and the following formula (3). The chemical structure (hereinafter referred to as “chemical structure (3)”) may be referred to as the chemical structure (2) and / or chemical structure (3) included in A as “chemical structure A1”. Or a divalent group having a chemical structure represented by the following formula (4) (hereinafter referred to as “chemical structure (4)” or “chemical structure A2”): 1) includes both chemical structure A1 and chemical structure A2. R is a hydrogen atom or a group represented by the following formula (5), and formula (1) represents at least one group represented by formula (5). N is a number from 1 to 500.)

(In Formula (2), R ¹ and R ² may be the same or different from each other, and are a divalent hydrocarbon group having 2 to 20 carbon atoms, and m is a number of 0 or more and 30 or less. .)

(In the formula (3), ^{R 3} is a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms, ^{R 4} is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms.)

(In Formula (4), R < ⁵ > -R < ⁸ > may mutually be same or different, and is a hydrogen atom or a C1-C6 hydrocarbon group, and R < ⁹ > is C2-C12 fat. A cyclic or aliphatic hydrocarbon group, or a halogenated hydrocarbon group having 1 to 12 carbon atoms, and R ¹⁰ is a hydrogen atom, a hydrocarbon group having 1 to 3 carbon atoms, or a halogenated carbon atom having 1 to 3 carbon atoms. It is a hydrogen group, and R ⁹ and R ¹⁰ may be bonded to each other to form a ring.)

<Chemical structure>
A in formula (1) representing the epoxy resin of the present invention includes both chemical structure A1 of chemical structure (2) and / or chemical structure (3) and chemical structure A2 of chemical structure (4).

In the formula (2), R ¹ and R ² may be the same or different from each other, and are divalent having 2 to 20 carbon atoms, preferably 2 to 15 carbon atoms, more preferably 2 to 8 carbon atoms. Of saturated hydrocarbon groups. The hydrocarbon group of R ¹ and R ² may have a linear or branched chain structure, and these may be combined. Moreover, the alicyclic structure may be included.

Preferred examples of R ¹ and R ² include ethylene group, propylene group, 1,4-butylene group, 1,5-pentylene group, 1,6-hexylene group, 1,8-octylene group, 1,4-cyclohexane. Examples thereof include alkyl groups such as hexylene group, cyclohexyl-1,4-methylene group, and groups obtained by combining alkyl groups, and more preferably ethylene group, propylene group, 1,4-butylene group, 1,6- A hexylene group, a cyclohexyl-1,4-methylene group, and the like.

M in the formula (2) is a number of 0 or more and 30 or less, preferably 0 or more and 20 or less.
The chemical structure (2) is derived from a bifunctional epoxy resin represented by the following formula (6) and / or a divalent hydroxyl group-containing compound represented by the formula (7) used as a raw material for the epoxy resin of the present invention. Therefore, the value determined based on m in the chemical structure (2) contained in the bifunctional epoxy resin represented by the formula (6) and / or the divalent hydroxyl group-containing compound represented by the formula (7) Will be considered.

In the formula (3), R ³ is a hydrocarbon group such as an alkyl group having 1 to 3 carbon hydrogen atom or a carbon, preferably hydrogen atom or a methyl group, more preferably a methyl group.

In the above formula (3), R ⁴ is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, preferably a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, more preferably a hydrogen atom or a carbon atoms 1 to 3 alkyl groups.

In said formula (4), R < ⁵ > -R < ⁸ > may mutually be same or different, and is a hydrogen atom and a C1-C6 hydrocarbon group. Examples of the hydrocarbon group having 1 to 6 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, and neopentyl group. And linear, branched or cyclic alkyl groups such as a group, tert-pentyl group, cyclopentyl group, n-hexyl group, isohexyl group, and cyclohexyl group.
R ^{5 to} R ⁸ are each independently a hydrogen atom or a C 1-4 such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, or a tert-butyl group. Alkyl groups are preferred.

In the formula (4), R ⁹ is a linear, branched or cyclic hydrocarbon group having 2 to 12 carbon atoms, preferably 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, or 1 to 12 carbon atoms. Preferably they are 1-6, More preferably, it is 1-3 halogenated hydrocarbon group, Preferably they are a linear or branched, alicyclic hydrocarbon group, or a halogenated hydrocarbon group. Here, the halogenated hydrocarbon group means a group in which at least one hydrogen atom of the hydrocarbon group is substituted with a halogen element, and the number of halogen elements in the halogenated hydrocarbon group is not particularly limited, The halogenated hydrocarbon group is preferably a group in which all hydrogen atoms are substituted with a halogen element, and the halogen element contained in the halogenated hydrocarbon group is preferably fluorine or bromine.

Examples of preferable R ⁹ include a linear alkyl group having 2 to 12 carbon atoms, a perfluoroalkyl group having 1 to 12 carbon atoms, a sec-butyl group, a tert-butyl group, an isopentyl group, a neopentyl group, and a tert-pentyl group. , Cyclopentyl group, isohexyl group, cyclohexyl group, cycloheptyl group, methylcyclohexyl group, cyclooctyl group, trimethylcyclohexyl group, cyclodecyl group, cyclododecyl group and the like. Among these, a C2-C10 linear alkyl group, a C1-C10 perfluoroalkyl group, a cyclohexyl group, a cycloheptyl group, a methylcyclohexyl group, a cyclooctyl group, and a trimethylcyclohexyl group are preferable.

In the formula (4), R ¹⁰ is a hydrogen atom, a hydrocarbon group having 1 to 3 carbon atoms or a halogenated hydrocarbon group having 1 to 3 carbon atoms, preferably a hydrogen atom, a methyl group, or a perhalogenomethyl group. It is. As the halogen element, fluorine and bromine are preferable.

When R ^{10 of} R ⁹ is bonded to each other to form a ring containing a carbon atom that serves as a linking group for two benzene rings, the ring structure is preferably a cycloalkane structure having 6 to 15 carbon atoms. The alkane may have 1 to 6 alkyl groups having 1 to 3 carbon atoms as a substituent. Examples of such a ring structure group include a cyclohexanediyl group, a cycloheptanediyl group, a methylcyclohexanediyl group, a cyclooctanediyl group, and a trimethylcyclohexanediyl group.

  In the formula (1), R is a hydrogen atom or a group (epoxy group) represented by the formula (5). Since the formula (1) represents an epoxy resin, as the terminal structure R, both ends may be the epoxy group of the formula (5), and only one end may be the epoxy group of the formula (5). . Alternatively, since the epoxy resin of the present invention is usually a mixture of molecules having these ends or molecules having different numbers of repetitions n described below, those having both ends are hydrogen atoms if the amount is small. May be included.

  In said Formula (1), n is a repeating number and is an average value. The range of the value is 1 or more from the viewpoint of flexibility, and is 500 or less from the viewpoint of handleability of the epoxy resin. From the viewpoint of making these better, n is preferably 1.5 or more, more preferably 2.0 or more, still more preferably 5.0 or more, while preferably 250 or less. More preferably, it is 100 or less, More preferably, it is 50 or less. The n number can be calculated from the number average molecular weight (Mn) obtained by the gel permeation chromatography method (GPC method). Specific examples of the GPC method for determining the number average molecular weight will be described in the examples below.

  In the formula (1), A includes at least the chemical structure A1 of the chemical structure (2) and / or the chemical structure (3) and the chemical structure A2 of the chemical structure (4), and is flexible and has a glass transition temperature. From the viewpoint of improving the balance of (Tg), the ratio of the chemical structure (2) in the chemical structure A1 is the number of moles of the entire A1 (that is, the sum of the chemical structure (2) and the chemical structure (3)). 0.1 to 100 mol%, particularly 1 to 100 mol%, particularly 5 to 100 mol% is preferable. As the proportion of the chemical structure (2) in the chemical structure A1 increases, the flexibility tends to improve, and as the proportion of the chemical structure (3) increases, the Tg tends to increase.

  The epoxy resin of the present invention has an effect of transparency and UV resistance by the chemical structure A1 of the chemical structure (2) and / or the chemical structure (3), and also by the chemical structure A2 of the chemical structure (4). While maintaining the UV resistance, the film-forming effect is obtained at the same time. As A in the formula (1), the molar ratio between the chemical structure A1 and the chemical structure A2, ie, [the total number of moles of the chemical structure (2) and the chemical structure (3)] / [mole of the chemical structure (4). The number] is preferably 1/99 or more, preferably 10/90 or more, more preferably 20/80 or more, from the viewpoint of transparency and UV resistance, while film formation From the viewpoint of property, it is preferably 99/1 or less, more preferably 90/10 or less, and still more preferably 80/20 or less.

  In the epoxy resin of the present invention, a chemical structure other than the chemical structure (2), the chemical structure (3), and the chemical structure (4) (hereinafter referred to as “other chemical structure”) as A in the formula (1). And may contain a divalent group having. Other chemical structures are not particularly limited, but structures derived from divalent hydroxyl group-containing compounds having aliphatic and alicyclic structures, and bifunctional epoxy resins obtained by epoxidizing these divalent hydroxyl group-containing compounds A chemical structure derived from is preferable.

  These chemical structures are combined in the production method described later with the above raw materials together with the bifunctional epoxy resin represented by the following formula (6) and / or the divalent hydroxyl group-containing compound represented by the formula (7). Can be introduced. Ratio of other chemical structure in A in the formula (1) (that is, the ratio of the chemical structure (2), the chemical structure (3), and the other chemical structure in the total of the chemical structure (4) and the other chemical structure ) Is usually 30 mol% or less, preferably 15 mol% or less, more preferably 5 mol% or less.

  In the epoxy resin of the present invention, the ratio of the chemical structure A1 that is the chemical structure (2) and / or the chemical structure (3), the chemical structure A2 that is the chemical structure (4), and other chemical structures is the epoxy described later. As described in the item of the method for producing a resin, it can be controlled by the ratio of raw materials. For this reason, in the epoxy resin of this invention, the ratio of the chemical structure contained in each of the bifunctional epoxy resin used as a raw material and the bivalent hydroxyl-containing compound is the chemical structure contained in the epoxy resin of this invention as it is. It shall be regarded as a percentage.

<Epoxy equivalent>
The epoxy equivalent of the epoxy resin of the present invention is 300 g / equivalent or more, preferably 800 g / equivalent or more, more preferably 5,000 g / equivalent or more, while 30,000 g / equivalent or less, preferably 25 5,000 equivalents or less, more preferably 20,000 g / equivalent or less, and even more preferably 15,000 g / equivalent or less. When the epoxy equivalent is not less than the above lower limit value, it is preferable from the viewpoint of flexibility, and when it is not more than the above upper limit value, the handling of the epoxy resin tends to be good. In the present invention, “epoxy equivalent” is defined as “the mass of an epoxy resin containing one equivalent of an epoxy group” and can be measured according to JIS K7236.

<Weight average molecular weight>
The weight average molecular weight (Mw) of the epoxy resin of the present invention is preferably 1,000 or more, more preferably 1,500 or more, on the other hand, preferably 100,000 or less, more preferably 50,000 or less. When the weight average molecular weight is not less than the above lower limit, it is preferable from the viewpoint of flexibility, and when it is not more than the above upper limit, the handling of the epoxy resin tends to be good. In addition, the weight average molecular weight and number average molecular weight of an epoxy resin can be measured by the gel permeation chromatography method (GPC method). An example of a more detailed method will be described in the examples described later.

<Glass transition temperature (Tg)>
Since the epoxy resin of the present invention has flexibility, it is useful as a flexibility imparting material. The flexibility-imparting material is preferably in a region where the glass transition temperature (Tg) is low to some extent, but when Tg is room temperature or lower, it is not preferable because it softens more than necessary when the use temperature rises. From this viewpoint, the glass transition temperature of the epoxy resin of the present invention is preferably 20 ° C. or higher, more preferably 30 ° C. or higher, on the other hand, preferably 145 ° C. or lower, and 120 ° C. or lower. It is more preferable. The glass transition temperature of the epoxy resin can be determined by a DSC method (differential scanning calorimeter). More specifically, it can be determined by the method described in the Examples below.

[Method for producing epoxy resin]
The epoxy resin of the present invention can be obtained by a two-stage method in which a bifunctional epoxy resin and a divalent hydroxyl group-containing compound are reacted. It can also be obtained by a one-step method in which two or more kinds of divalent hydroxyl group-containing compounds and epichlorohydrin are directly reacted. However, in the two-stage method, it is preferable to use the two-stage method because various epoxy resins from low molecular weight to high molecular weight can be obtained more easily than in the one-stage method.

<Manufacturing method by two-stage method>
As a method for producing the epoxy resin of the present invention by a two-stage method, at least a bifunctional epoxy resin represented by the following formula (6) and a divalent hydroxyl group-containing compound represented by the following formula (7) are reacted. A method is mentioned.

(In the formulas (6) and (7), A ′ is a divalent group having the chemical structure (2), the chemical structure (3), or the chemical structure (4), and A ′ in the formula (6) A ′ in formula (7) includes at least the chemical structure (2) and / or the chemical structure (3) and the chemical structure (4), where n ′ is an average value of the number of repetitions and is 0 or more and 6 or less. is there.)

(Bifunctional epoxy resin)
The bifunctional epoxy resin used for the production of the epoxy resin of the present invention is an epoxy resin represented by the formula (6). For example, a divalent hydroxyl group-containing compound represented by the formula (7) will be described later. An epoxy resin obtained by condensing with epihalohydrin by a method similar to the one-step method.

In the formula (6), A ′ may or may not include the chemical structure (2) and / or the chemical structure (3). However, when A ′ in the formula (6) does not include the chemical structure (2) and / or the chemical structure (3), A ′ in the formula (7) represents the chemical structure (2) and / or chemistry. The structure (3) is necessarily included. In the formula (6), A ′ may or may not contain the chemical structure (4). However, when A ′ in the formula (6) does not include the chemical structure (4), A ′ in the formula (7) necessarily includes the chemical structure (4).
In producing the epoxy resin of the present invention, a bifunctional epoxy resin (hereinafter referred to as “A ′” in the formula (6)) which does not contain any of the chemical structure (2), the chemical structure (3) and the chemical structure (4). "Other bifunctional epoxy resins" may be used in combination. In that case, as the other bifunctional epoxy resins, those having any known chemical structure in A ' Can be used.

(Divalent hydroxyl group-containing compound)
The divalent hydroxyl group-containing compound used for the production of the epoxy resin of the present invention is a divalent hydroxyl group-containing compound represented by the formula (7).

In the formula (7), A ′ may or may not include the chemical structure (2) and / or the chemical structure (3). However, when A ′ in the formula (7) does not include the chemical structure (2) and / or the chemical structure (3), A ′ in the formula (6) represents the chemical structure (2) and / or chemistry. The structure (3) is necessarily included. In the formula (7), A ′ may or may not contain the chemical structure (4). However, when A ′ in the formula (7) does not include the chemical structure (4), A ′ in the formula (6) necessarily includes the chemical structure (4).
In addition, when manufacturing the epoxy resin of this invention, the bivalent hydroxyl-containing compound which does not contain any of chemical structure (2), chemical structure (3), and chemical structure (4) as A 'in said Formula (7). (Hereinafter sometimes referred to as “other divalent hydroxyl group-containing compounds”) may be used in combination, and in this case, as other divalent hydroxyl group-containing compounds, any of the known A ′ compounds may be used. Those having a chemical structure can be used.

  That is, the epoxy resin of the present invention produced by the two-stage method always includes the chemical structure (2) and / or the chemical structure (3), and as long as this is satisfied, the chemical structure (2) and / or Alternatively, the chemical structure (3) may be contained in any of the bifunctional epoxy resin and the divalent hydroxyl group-containing compound, and the ratio of the chemical structure is not limited. Similarly, the epoxy resin of the present invention produced by the two-step method always contains the chemical structure (4), and as long as this is satisfied, the chemical structure (4) is a bifunctional epoxy resin and a divalent epoxy resin. The compound may be contained in any of the hydroxyl group-containing compounds, and the proportion of the chemical structure is not limited. Furthermore, other bifunctional epoxy resins and / or other divalent hydroxyl group-containing compounds that do not contain the chemical structure (2) and / or the chemical structure (3) or the chemical structure (4) in the above formula (1) As long as it does not exceed the upper limit of the ratio of the other chemical structure in A, it can be used.

(catalyst)
A catalyst may be used for the synthesis of the epoxy resin of the present invention, and any catalyst may be used as long as it has a catalytic ability to promote a reaction between an epoxy group and a phenolic hydroxyl group, an alcoholic hydroxyl group or a carboxyl group. Something like that. For example, alkali metal compounds, organic phosphorus compounds, tertiary amines, quaternary ammonium salts, cyclic amines, imidazoles and the like can be mentioned.

  Among the catalysts mentioned above, quaternary ammonium salts are preferred. Moreover, a catalyst can use only 1 type and can also be used in combination of 2 or more type. The usage-amount of a catalyst is 0.001-1 weight% normally in reaction solid content. Here, the reaction solid content refers to the total of reaction substrates other than the solvent in the reaction system.

(solvent)
The epoxy resin of the present invention may use a reaction solvent in the step of the synthesis reaction at the time of production, and any solvent may be used as long as it dissolves the epoxy resin. Examples include aromatic solvents, ketone solvents, amide solvents, glycol ether solvents, and the like.

  Specific examples of the aromatic solvent include benzene, toluene, xylene and the like. Specific examples of the ketone solvent include acetone, methyl ethyl ketone (hereinafter sometimes referred to as “MEK”), methyl isobutyl ketone (hereinafter sometimes referred to as “MIBK”), 2-heptanone, 4 -Heptanone, 2-octanone, cyclohexanone, acetylacetone, dioxane and the like. Specific examples of the amide solvent include formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, 2-pyrrolidone, N-methylpyrrolidone and the like. Specific examples of the glycol ether solvent include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol. Examples include mono-n-butyl ether, diethylene glycol dimethyl ether, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol mono-n-butyl ether, propylene glycol monomethyl ether acetate. These solvents may be used alone or in combination of two or more.

(solvent)
The solid concentration in the synthesis reaction during the production of the epoxy resin is preferably 35 to 100% by weight. For this reason, you may use the organic compound similar to what was mentioned in the above-mentioned solvent as a solvent for dilution. For example, when a highly viscous product is produced during the reaction, the reaction can be continued by adding an additional solvent. After completion of the reaction, the solvent can be removed or further added as necessary. In the present invention, the term “solvent” and the term “solvent” are distinguished from each other depending on the form of use, but the same type or different types may be used.

(Reaction conditions)
In the production of an epoxy resin, a polymerization reaction between a bifunctional epoxy resin and a divalent hydroxyl group-containing compound is carried out at a reaction temperature at which the used catalyst is not decomposed. If the reaction temperature is too high, the produced epoxy resin may be deteriorated. Conversely, if the temperature is too low, the reaction may not proceed sufficiently. For these reasons, the reaction temperature is preferably 50 to 230 ° C, more preferably 120 to 200 ° C. Moreover, reaction time is 1 to 12 hours normally, Preferably it is 3 to 10 hours. When using a low boiling point solvent such as acetone or methyl ethyl ketone, the reaction temperature can be ensured by carrying out the reaction under high pressure using an autoclave.

<Manufacturing by one-step method>
The epoxy resin of the present invention can also be produced by a one-step method. Specifically, the divalent hydroxyl group-containing compound represented by the formula (7) may be directly reacted with epichlorohydrin. However, as described above, among the epoxy resins of the present invention produced by the one-step method, those having a low molecular weight can be used as the bifunctional epoxy resin in the two-step method.

  The amount of epihalohydrin used in the reaction is usually 0.8 to 20 mole equivalents, preferably 0.9 to 15 mole equivalents, more preferably 1.0 to 10 moles per mole equivalent of hydroxyl groups of the divalent hydroxyl group-containing compound. The amount is equivalent to an equivalent amount, and a divalent hydroxyl group-containing compound is dissolved in epihalohydrin to obtain a uniform solution. It is preferable that the amount of the epihalohydrin is not less than the above lower limit value because the molecular weight is not increased more than necessary, the reaction is easily controlled, and an appropriate melt viscosity can be obtained. On the other hand, when the amount of epihalohydrin is not more than the above upper limit value, production efficiency tends to be improved, which is preferable. As epihalohydrin in this reaction, epichlorohydrin and / or epibromohydrin is usually used.

  Next, while stirring the solution of the bifunctional epoxy resin and epihalohydrin, it is usually 0.5 to 2.0 mole equivalent, preferably 0.7 to 1.8 per mole equivalent of hydroxyl group of the divalent hydroxyl group-containing compound. An alkali metal hydroxide in an amount corresponding to a molar equivalent, more preferably 0.9 to 1.6 molar equivalent, is added as a solid or an aqueous solution and reacted. It is preferable that the amount of the alkali metal hydroxide is not less than the above lower limit value because it is possible to prevent the unreacted hydroxyl group and the generated epoxy resin from reacting to increase the molecular weight more than necessary. Moreover, it is preferable for the alkali metal hydroxide to be not more than the above upper limit value because the generation of impurities due to side reactions can be reduced. As the alkali metal hydroxide, sodium hydroxide and / or potassium hydroxide is usually used.

  This reaction can be performed under normal pressure or reduced pressure, and the reaction temperature is usually 20 to 150 ° C., preferably 30 to 120 ° C., more preferably 35 to 100 ° C. in the case of reaction under normal pressure. In the case of the lower reaction, it is usually 20 to 100 ° C, preferably 30 to 90 ° C, more preferably 35 ° C to 80 ° C. It is preferable that the reaction temperature is equal to or higher than the lower limit because the reaction is likely to proceed. When the reaction temperature is not more than the above upper limit, side reactions are unlikely to proceed. In particular, when epichlorohydrin is used as the epihalohydrin, it is preferable because chlorine impurities can be easily reduced.

  During the reaction, the reaction liquid is azeotroped while maintaining a predetermined temperature as necessary, and the condensed liquid obtained by cooling the vaporized vapor is separated into oil and water, and the oil without water is reacted. Dehydrated by returning to the system. The addition of alkali metal hydroxide is preferably 0.5 to 8 hours, more preferably 1 to 7 hours, and still more preferably 1 to 6 hours, in order to suppress a rapid reaction, intermittently or continuously. Add it. It is preferable for the addition time to be equal to or greater than the above lower limit value since it is possible to prevent the reaction from proceeding rapidly and to easily control the reaction temperature. On the other hand, when the addition time is equal to or shorter than the above upper limit value, it is preferable when epichlorohydrin is used as the epihalohydrin because chlorine impurities are not easily generated, and it is also preferable from the viewpoint of economy. The total reaction time is usually 1 to 15 hours. After completion of the reaction, the insoluble by-product salt is removed by filtration or removed by washing with water, and then the unreacted epihalohydrin is removed by distillation under reduced pressure to obtain the desired epoxy resin.

  In this reaction, quaternary ammonium salts such as tetramethylammonium chloride and tetraethylammonium bromide; tertiary amines such as benzyldimethylamine and 2,4,6-tris (dimethylaminomethyl) phenol; 2-ethyl Imidazoles such as -4-methylimidazole and 2-phenylimidazole; phosphonium salts such as ethyltriphenylphosphonium iodide; phosphines such as triphenylphosphine; acidic catalysts such as sulfuric acid, boron trifluoride ethyl ether, and tin tetrachloride A catalyst such as the above may be used.

  Furthermore, in this reaction, alcohols such as ethanol and isopropanol; ketones such as acetone and methyl ethyl ketone; ethers such as dioxane and ethylene glycol dimethyl ether; glycol ethers such as methoxypropanol; aprotic such as dimethyl sulfoxide and dimethylformamide An inert organic solvent such as a polar solvent may be used.

  Furthermore, when the amount of saponifiable halogen in the epoxy resin obtained as described above is too large, a purified epoxy resin having a sufficiently reduced amount of saponifiable halogen can be obtained by reprocessing. That is, the crude epoxy resin is redissolved in an inert organic solvent such as isopropyl alcohol, methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene, dioxane, methoxypropanol, dimethyl sulfoxide, and the alkali metal hydroxide is dissolved in a solid or aqueous solution. In addition, preferably at a temperature of 30 to 120 ° C, more preferably 40 to 110 ° C, still more preferably 50 to 100 ° C, preferably 0.1 to 15 hours, more preferably 0.3 to 12 hours, still more preferably. After carrying out the re-ringing reaction for 0.5 to 10 hours, the excess alkali metal hydroxide or by-product salt is removed by a method such as washing, and further the organic solvent is distilled off under reduced pressure and / or steam distillation. An epoxy resin with a reduced amount of hydrolyzable halogen can be obtained. It is preferable for the reaction temperature to be within the above range and to be not more than the above upper limit value because the re-ring closure reaction will easily proceed. Moreover, it is preferable for the reaction temperature to be within the above range because the high molecular weight reaction can be easily controlled.

[Epoxy resin composition]
The epoxy resin composition of the present invention is an epoxy resin composition containing at least the above-described epoxy resin of the present invention and a curing agent. Moreover, the epoxy resin composition of this invention can mix | blend suitably another epoxy resin, another component, etc. as needed. The epoxy resin composition of the present invention has a well-balanced film-forming property, transparency, UV resistance, and flexibility, and provides a cured product that sufficiently satisfies various physical properties required for various applications.

<Curing agent>
In the present invention, the curing agent means a substance that contributes to a crosslinking reaction and / or a chain extension reaction between epoxy groups of an epoxy resin. In the present invention, even a substance that is usually called a “curing accelerator” is regarded as a curing agent if it is a substance that contributes to a crosslinking reaction and / or chain extension reaction between epoxy groups of an epoxy resin. .

  The content of the curing agent in the epoxy resin composition of the present invention is preferably 0.1 to 100 parts by weight with respect to 100 parts by weight of the epoxy resin of the present invention. Further, it is more preferably 80 parts by weight or less, and still more preferably 60 parts by weight or less.

  Further, in the epoxy resin composition of the present invention, when other epoxy resin described later other than the epoxy resin of the present invention is included, the content of the curing agent is based on 100 parts by weight of the total epoxy resin component as a solid content. Preferably it is 0.1-100 weight part. Further, it is more preferably 80 parts by weight or less, and still more preferably 60 parts by weight or less. In the present invention, the “solid content” means a component excluding the solvent, and includes not only a solid epoxy resin but also a semi-solid or viscous liquid material. The “total epoxy resin component” means the total of the epoxy resin of the present invention and other epoxy resins described later.

  There is no restriction | limiting in particular as a hardening | curing agent used for the epoxy resin composition of this invention, What is generally known as an epoxy resin hardening | curing agent can be used. Among them, preferred are phenol-based curing agents, amide-based curing agents, amine-based curing agents (excluding tertiary amines), imidazoles, acid anhydride-based curing agents, and organic phosphines. Examples of phenolic curing agents, amide curing agents, amine curing agents (excluding tertiary amines), imidazoles, acid anhydride curing agents, organic phosphines, and other usable curing agents Give up.

[Phenolic curing agent]
It is preferable to use a phenol-based curing agent as the curing agent from the viewpoint of improving the handleability of the resulting epoxy resin composition and the heat resistance after curing. Specific examples of the phenolic curing agent include bisphenol A, bisphenol F, 4,4′-dihydroxydiphenylmethane, 4,4′-dihydroxydiphenyl ether, 1,4-bis (4-hydroxyphenoxy) benzene, 1,3-bis. (4-hydroxyphenoxy) benzene, 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl ketone, 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxybiphenyl, 2,2'-dihydroxybiphenyl 10- (2,5-dihydroxyphenyl) -10H-9-oxa-10-phosphaphenanthrene-10-oxide, phenol novolak, bisphenol A novolak, o-cresol novolak, m-cresol novolak, p-cresol Novo Lac, xylenol novolac, poly-p-hydroxystyrene, hydroquinone, resorcin, catechol, t-butylcatechol, t-butylhydroquinone, fluoroglycinol, pyrogallol, t-butyl pyrogallol, allylated pyrogallol, polyallylated pyrogallol, 1,2 , 4-Benzenetriol, 2,3,4-trihydroxybenzophenone, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene 1,7-dihydroxynaphthalene, 1,8-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,4-dihydroxynaphthalene, 2,5-dihydroxynaphthalene, 2,6-dihydride Examples include xinaphthalene, 2,7-dihydroxynaphthalene, 2,8-dihydroxynaphthalene, allylated or polyallylated dihydroxynaphthalene, allylated bisphenol A, allylated bisphenol F, allylated phenol novolak, allylated pyrogallol and the like. .

  The phenolic curing agents mentioned above may be used alone or in a combination of two or more in any combination and ratio. Moreover, when a hardening | curing agent is a phenol type hardening | curing agent, it is preferable to use so that it may become the range of 0.8-1.5 by the equivalent ratio of the functional group in a hardening | curing agent with respect to the epoxy group in an epoxy resin. Within this range, unreacted epoxy groups and functional groups of the curing agent are unlikely to remain, which is preferable.

[Amide-based curing agent]
It is preferable to use an amide-based curing agent as the curing agent from the viewpoint of improving heat resistance and the like. Examples of the amide-based curing agent include dicyandiamide and derivatives thereof, and polyamide resins.

  The amide type curing agents listed above may be used alone or in a combination of two or more in any combination and ratio. Moreover, it is preferable to use an amide type hardening | curing agent in 0.1-20 weight% with respect to the sum total of all the epoxy resin components and amide type hardening | curing agents as solid content in an epoxy resin composition.

[Amine curing agent]
It is preferable to use an amine-based curing agent (excluding tertiary amine) as the curing agent from the viewpoint of improving heat resistance and the like. Examples of amine-based curing agents include aliphatic amines, polyether amines, alicyclic amines, aromatic amines and the like. Aliphatic amines include ethylenediamine, 1,3-diaminopropane, 1,4-diaminopropane, hexamethylenediamine, 2,5-dimethylhexamethylenediamine, trimethylhexamethylenediamine, diethylenetriamine, iminobispropylamine, bis ( Hexamethylene) triamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, N-hydroxyethylethylenediamine, tetra (hydroxyethyl) ethylenediamine and the like are exemplified. Examples of polyether amines include triethylene glycol diamine, tetraethylene glycol diamine, diethylene glycol bis (propylamine), polyoxypropylene diamine, polyoxypropylene triamines, and the like. Cycloaliphatic amines include isophorone diamine, metacene diamine, N-aminoethylpiperazine, bis (4-amino-3-methyldicyclohexyl) methane, bis (aminomethyl) cyclohexane, 3,9-bis (3-amino). Propyl) -2,4,8,10-tetraoxaspiro (5,5) undecane, norbornenediamine and the like. Aromatic amines include tetrachloro-p-xylenediamine, m-xylenediamine, p-xylenediamine, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, 2,4-diaminoanisole, 2,4 -Toluenediamine, 2,4-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diamino-1,2-diphenylethane, 2,4-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, m-aminophenol, m-aminobenzylamine, benzyldimethylamine, 2- (dimethylaminomethyl) phenol, triethanolamine, methylbenzylamine, α- (m-aminophenyl) ethylamine, α- (p-aminophenyl) Ethylamine, diaminodiethyl Examples thereof include dimethyldiphenylmethane and α, α′-bis (4-aminophenyl) -p-diisopropylbenzene.

  The amine curing agents mentioned above may be used alone or in any combination and blending ratio. Moreover, it is preferable to use an amine hardening | curing agent so that it may become the range of 0.8-1.5 by the equivalent ratio of the functional group in a hardening | curing agent with respect to the epoxy group in an epoxy resin. Within this range, unreacted epoxy groups and functional groups of the curing agent are unlikely to remain, which is preferable.

[Imidazoles]
It is preferable to use imidazoles as the curing agent from the viewpoint of sufficiently proceeding the curing reaction and improving the heat resistance. Examples of imidazoles include 2-phenylimidazole, 2-ethyl-4 (5) -methylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1 -Cyanoethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino- 6- [2′-Methylimidazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino-6- [2′-ethyl-4′-methylimidazolyl- (1 ′)]-ethyl-s -Triazine, 2,4-diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-s-tri Azine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, and an epoxy resin and the above imidazoles Examples include adducts. In addition, since imidazoles have catalytic ability, they can generally be classified as curing accelerators described later, but in the present invention, they are classified as curing agents.

  The imidazoles listed above may be used alone or in combination of two or more in any combination and ratio. Moreover, it is preferable to use imidazole in 0.1-20 weight% with respect to the sum total of all the epoxy resin components and imidazoles as solid content in an epoxy resin composition.

[Acid anhydride curing agent]
It is preferable to use an acid anhydride curing agent as the curing agent from the viewpoint of heat resistance. Examples of the acid anhydride curing agent include acid anhydrides and modified acid anhydrides.

  Examples of acid anhydrides include phthalic acid anhydride, trimellitic acid anhydride, pyromellitic acid anhydride, benzophenone tetracarboxylic acid anhydride, dodecenyl succinic acid anhydride, polyadipic acid anhydride, polyazelinic acid anhydride, polysebacic acid Anhydride, poly (ethyloctadecanedioic acid) anhydride, poly (phenylhexadecanedioic acid) anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride , Methyl hymic anhydride, tetrahydrophthalic anhydride, trialkyltetrahydrophthalic anhydride, methylcyclohexene dicarboxylic anhydride, methylcyclohexene tetracarboxylic anhydride, ethylene glycol bistrimellitic dianhydride, het acid anhydride , Najit Acid anhydride, methyl nadic acid anhydride, 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexane-1,2-dicarboxylic acid anhydride, 3,4-dicarboxy- 1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride, 1-methyl-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride, TBN-40C (new Nippon Rika Co., Ltd.).

  Examples of modified acid anhydrides include those obtained by modifying the above acid anhydride with glycol. Examples of glycols that can be used for modification include alkylene glycols such as ethylene glycol, propylene glycol, and neopentyl glycol; polyether glycols such as polyethylene glycol, polypropylene glycol, and polytetramethylene ether glycol. It is done. Furthermore, a copolymer polyether glycol of two or more kinds of these and / or polyether glycol can also be used. In addition, in the modified product of acid anhydride, it is preferable to modify with 0.4 mol or less of glycol with respect to 1 mol of acid anhydride. When the modification amount is not more than the above upper limit, the viscosity of the epoxy resin composition does not become too high, the workability tends to be good, and the rate of the curing reaction with the epoxy resin also tends to be good. .

  The acid anhydride curing agents mentioned above may be used alone or in combination of two or more in any combination and amount. When an acid anhydride curing agent is used, it is preferably used so that the equivalent ratio of the functional group in the curing agent to the epoxy group in the epoxy resin is in the range of 0.8 to 1.5. Within this range, unreacted epoxy groups and functional groups of the curing agent are unlikely to remain, which is preferable.

[Organic phosphines]
Use of organic phosphines as the curing agent is preferable from the viewpoint of providing a cured product having excellent curability and high electrical reliability. Examples of organic phosphines include tributylphosphine, methyldiphenylphosphine, triphenylphosphine, diphenylphosphine, and phenylphosphine.

  The organic phosphines listed above may be used alone or in a combination of two or more in any combination and ratio. Moreover, it is preferable to use organic phosphines in the range of 0.1-20 weight% with respect to the sum total of all the epoxy resin components and organic phosphines as solid content in an epoxy resin composition.

[Other curing agents]
As a curing agent that can be used in the epoxy resin composition of the present invention, other than phenolic curing agents, amide curing agents, amine curing agents, imidazoles, acid anhydride curing agents, and organic phosphines, Examples include mercaptan curing agents, tertiary amines, phosphonium salts, tetraphenyl boron salts, organic acid dihydrazides, boron halide amine complexes, isocyanate curing agents, block isocyanate curing agents, and the like. Among these, examples of the phosphonium salt include tetraphenylphosphonium / tetraphenylborate, tetraphenylphosphonium / ethyltriphenylborate, tetrabutylphosphonium / tetrabutylborate and the like, and examples of the tetraphenylboron salt include 2-ethyl-4- Examples thereof include methylimidazole / tetraphenylborate and N-methylmorpholine / tetraphenylborate. The other hardening | curing agents mentioned above may be used only by 1 type, and 2 or more types may be mixed and used for them in arbitrary combinations and ratios.

<Other epoxy resins>
The epoxy resin composition of the present invention can contain other epoxy resins in addition to the epoxy resin of the present invention. By using other epoxy resins, the insufficient physical properties can be compensated or various physical properties can be improved.

  The other epoxy resin preferably has two or more epoxy groups in the molecule. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, naphthalene type epoxy resin, phenol novolac type epoxy resin, Use various epoxy resins such as cresol novolac type epoxy resin, phenol aralkyl type epoxy resin, biphenyl type epoxy resin, triphenylmethane type epoxy resin, dicyclopentadiene type epoxy resin, and hydrogenated products of these epoxy resins. Can do. These can be used alone or as a mixture of two or more.

  In the epoxy resin composition of the present invention, when the epoxy resin of the present invention and another epoxy resin are used, the amount of the other epoxy resin in the total epoxy resin component is preferably 1% by weight or more, more preferably Is 5% by weight or more, on the other hand, preferably 99% by weight or less, more preferably 95% by weight or less. When the ratio of the other epoxy resin is not less than the above lower limit value, the effect of improving the physical properties by blending the other epoxy resin can be sufficiently obtained, and in particular, it is more excellent in heat resistance than the epoxy resin itself of the present invention. Material can be obtained. On the other hand, when the ratio of the other epoxy resin is not more than the above upper limit value, the effect of the epoxy resin of the present invention is sufficiently exhibited, and the film-forming property, transparency, UV resistance, and flexibility are sufficiently obtained. This is preferred because of the tendency to be able to.

<Solvent>
The epoxy resin composition containing the epoxy resin of the present invention may be diluted by blending a solvent in order to appropriately adjust the viscosity of the epoxy resin composition at the time of handling during coating film formation. In the epoxy resin composition of the present invention, the solvent is used in order to ensure the handleability and workability in the molding of the epoxy resin composition, and the amount used is not particularly limited.

  Examples of the solvent that can be contained in the epoxy resin composition containing the epoxy resin of the present invention include ketones such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone and cyclohexanone, esters such as ethyl acetate, and ethers such as ethylene glycol monomethyl ether. Amides such as N, N-dimethylformamide and N, N-dimethylacetamide, alcohols such as methanol and ethanol, alkanes such as hexane and cyclohexane, and aromatics such as toluene and xylene. The solvent mentioned above may be used only by 1 type, and may mix and use 2 or more types by arbitrary combinations and a ratio.

<Other ingredients>
In the epoxy resin composition containing the epoxy resin of the present invention, components other than those listed above (sometimes referred to as “other components” in the present invention) for the purpose of further improving the functionality. May be included. Other ingredients include inorganic fillers, coupling agents such as silane coupling agents, UV inhibitors, antioxidants, plasticizers, fluxes, flame retardants, colorants, dispersants, emulsifiers, low elasticity agents, diluents. , Antifoaming agents, ion trapping agents, leveling agents, catalysts and the like.

[Cured product]
A cured product obtained by curing the epoxy resin composition of the present invention is excellent in balance in film-forming properties, transparency, UV resistance and flexibility, and exhibits excellent cured properties. The term “curing” as used herein means that the epoxy resin composition is intentionally cured by heat and / or light, and the degree of curing may be controlled by desired physical properties and applications. . The degree of progression may be completely cured or semi-cured, and is not particularly limited. However, the reaction rate of the curing reaction between the epoxy group and the curing agent is usually 5 to 95%.

  The curing method of the epoxy resin composition when the epoxy resin composition of the present invention is cured or semi-cured to obtain a cured product or semi-cured product varies depending on the blending component and blending amount in the epoxy resin composition, but usually A heating condition of 60 to 180 minutes at 80 to 200 ° C. is mentioned. This heating may be performed in a two-stage process of primary heating at 80 to 160 ° C. for 10 to 30 minutes and secondary heating at 120 to 200 ° C. that is 40 to 120 ° C. higher than the primary heating temperature for 60 to 150 minutes, This is preferable from the viewpoint of reducing curing failure.

  When producing the resin semi-cured product, the curing reaction of the epoxy resin composition is advanced to such an extent that the shape can be maintained by heating or the like. When the epoxy resin composition contains a solvent, most of the solvent is removed by techniques such as heating, decompression, and air drying, but a solvent of 5% by weight or less may remain in the resin semi-cured product. .

[Use]
The epoxy resin of the present invention and the epoxy resin composition containing the epoxy resin have sufficient flexibility to be applied to processes such as casting, film forming / coating, etc., and film-forming properties, transparency, UV resistance It can be applied to various fields such as adhesives, paints, optical members, civil engineering materials, and insulating materials for electrical and electronic parts. In particular, it is useful as an insulating casting material, a laminate material, a sealing material, etc. in the electric / electronic field, and examples thereof include a laminate for an electric / electronic circuit and a sealing material for an electric / electronic circuit. As an example of the use of the epoxy resin of the present invention and the epoxy resin composition containing the epoxy resin, an optical material adhesive, a semiconductor sealing material, an underfill material, an organic RL sealing material, a die bonding material, and a film adhesive Adhesives such as liquid adhesives, multilayer printed wiring boards, laminates for electrical / electronic circuits such as capacitors, insulation sheets, prepregs, heat dissipation boards, and adhesion improvers and flexibility for electrical / electronic / optical applications Although materials etc. are mentioned, it is not limited to these at all.

  In the present invention, the “laminate for electric / electronic circuit” is a laminate of a layer containing the epoxy resin composition of the present invention and a conductive metal layer made of copper, aluminum, an alloy thereof or the like. As long as the layer containing the epoxy resin composition of the present invention and the conductive metal layer are laminated, it can be used as a concept including, for example, a capacitor instead of an electric / electronic circuit. In addition, the layer which consists of 2 or more types of epoxy resin compositions may be formed in the laminated board for electric / electronic circuits, and the epoxy resin composition of this invention should just be used in at least 1 layer. . Two or more kinds of conductive metal layers may be formed.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example, this invention is not limited at all by the following example. In addition, the value of various manufacturing conditions and evaluation results in the following examples has a meaning as a preferable value of the upper limit or the lower limit in the embodiment of the present invention, and the preferable range is the above-described upper limit or lower limit value. A range defined by a combination of values of the following examples or values of the examples may be used. In the following, all “parts” indicate “parts by weight”. In addition, the following measurement methods for various physical properties and characteristics are as follows.

1) Weight average molecular weight (Mw) and number average molecular weight (Mn)
Using “HLC-8320GPC EcoSEC (registered trademark)” manufactured by Tosoh Corporation, under the following measurement conditions, as standard polystyrene, TSK Standard Polystyrene: F-128 (Mw 1,090,000, Mn 1,030,000), F-10 (Mw 106,000, Mn 103,000), F-4 (Mw 43,000, Mn 42,700), F-2 (Mw 17,200, Mn 16,900), A-5000 (Mw 6,400, Mn 6,100) ), A-2500 (Mw2,800, Mn2,700), calibration curves using A-300 (Mw453, Mn387) were prepared, and the weight average molecular weight and number average molecular weight were measured as polystyrene conversion values.
Column: “TSKGEL SuperHM-H + H5000 + H4000 + H3000 + H2000” manufactured by Tosoh Corporation
Eluent: Tetrahydrofuran Flow rate: 0.5 ml / min
Detection: UV (wavelength 254 nm)
Temperature: 40 ° C
Sample concentration: 0.1% by weight
Injection volume: 10 μl

2) Epoxy equivalent Measured according to JIS K7236, and expressed as a solid content converted value.

3) Glass transition temperature (Tg)
About epoxy resin, SII nanotechnology Co., Ltd. product differential scanning calorimeter "DSC7020" was used, it heated up at 30 degreeC to 200 degreeC at 10 degree-C / min, and the glass transition temperature was measured. The glass transition temperature mentioned here was measured based on “midpoint glass transition temperature: Tmg” described in JIS K7121 “Method for measuring plastic transition temperature”.

4) Reactivity In each Example and Comparative Example, even if the reaction was carried out in the same manner using only tetra-n-butylphosphonium hydroxide as a catalyst and the amount thereof being 2500 ppm based on the reaction solid content, the residual monomer (Mn 1000 or less) ) Was evaluated as x for those having 50% or more and ◯ for those having less than 50%. The amount of residual monomer was calculated using the area percentage of GPC (detector: RI).

5) Transparency (preparation of test piece)
Using an applicator, the epoxy resin composition was applied onto a separator (silicone-treated polyethylene terephthalate film) to form a coating film, heated at 100 ° C. for 3 hours, and then cured at 140 ° C. for 3 hours. The obtained epoxy resin cured film was cut into 40 mm × 120 mm to obtain a test piece.
(Test conditions)
About the obtained test piece, the transmittance | permeability of the light of the wavelength range 190-890nm was measured using Hitachi U-Tech Science company "UH5300". The light transmittance at a wavelength of 400 nm was evaluated as ◎, when the transmittance was 89% or more, ◯ when less than 89% and 85% or more, Δ when less than 85% and 82% or more, and × when less than 82%.

6) UV resistance (preparation of test piece)
Using an applicator, the epoxy resin composition was applied onto a separator (silicone-treated polyethylene terephthalate film) to form a coating film, heated at 100 ° C. for 3 hours, and then cured at 140 ° C. for 3 hours. The obtained epoxy resin cured film was cut into 40 mm × 120 mm to obtain a test piece.
(Test conditions)
The obtained test piece was subjected to UV irradiation for 2 days using “MV3000” (light source: xenon lamp (0.4 kW / m ² ), atmosphere: 63 ° C., 50% RH) manufactured by Suga Test Instruments Co., Ltd. It was. About the test piece after UV irradiation, the transmittance | permeability of the light of the wavelength range 190-890 nm was measured using the Hitachi High-Tech Science company "UH5300". The transmittance of light with a wavelength of 360 nm is 40% or more and the transmittance of light with a wavelength of 400 nm is 50% or more, and the transmittance of light with a wavelength of 360 nm is less than 40% and the transmittance of light with a wavelength of 400 nm is 50%. The above were evaluated as O, and the transmittance of light having a wavelength of 360 nm was less than 40% and the transmittance of light having a wavelength of 400 nm was less than 50%.

7) Film-forming property Using an applicator, the epoxy resin composition is applied onto a separator (silicone-treated polyethylene terephthalate film) to form a coating film, heated at 100 ° C for 3 hours, and then heated at 140 ° C for 3 hours. After the time curing, the appearance was observed, and the case of film shape was evaluated as ◯, and the case where the film shape was not maintained by repelling was evaluated as x.

8) Flexibility Using an applicator, the epoxy resin composition is applied on a separator (silicone-treated polyethylene terephthalate film) to form a coating film, heated at 100 ° C. for 3 hours, and then at 140 ° C. for 3 hours. Cured.
The obtained cured epoxy resin film was evaluated as “◯” when it was not broken even when it was folded 180 °, “Δ” when the foldable angle was less than 180 °, and “x” when it could not be folded.

[material]
The raw materials, catalysts, solvents and solvents used in the following examples and comparative examples are as follows.

<Bifunctional epoxy resin>
(Bifunctional epoxy resin having chemical structure (3))
(A-1): Hydrogenated bisphenol A type epoxy resin (trade name “YX8000” manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 198 g / equivalent) (R ³ , R ⁴ = —CH ₃ )
(Bifunctional epoxy resin having chemical structure (2))
(A-2): 1,6-hexanediol diglycidyl ether (trade name “YED216D” manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 116 g / equivalent) (R ¹ = — (CH ₂ ) ₆ —, m = 0)
(Other bifunctional epoxy resins)
(A-3): 3,3 ′, 5,5′-tetramethyl-4,4′-biphenol diglycidyl ether (trade name “YX4000” manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 185 g / equivalent)

<Divalent hydroxyl group-containing compound>
(Divalent hydroxyl group-containing compound having chemical structure (4))
(B-1): Bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane (hydroxyl equivalent 155 g / equivalent) (R ^{5 to} R ⁸ = −H, R ⁹ + R ¹⁰ = 3,3,5- Trimethyl-1,1-cyclohexanediyl group)
(B-2): 4,4′-butylidenebis- (6-tert-butyl-3-methylphenol) (hydroxyl equivalent 192 g / equivalent) (R ⁵ , R ⁷ = —CH ₃ , R ⁶ , R ⁸ = − _{^{t-C 4 H 9, R}} 9 = -C 3 H 7, R 10 = -H)
(B-3): Bisphenol AF (hydroxyl equivalent 168 g / equivalent) (R ^{5 to} R ⁸ = -H, R ⁹ , R ¹⁰ = -CF ₃ )
(Other divalent hydroxyl group-containing compounds)
(B-4): Bisphenol F (hydroxyl group equivalent: 100 g / equivalent)
(Divalent hydroxyl group-containing compound having chemical structure (2))
(B-5): 1,6-hexanediol (hydroxyl equivalent 59 g / equivalent) (R ¹ = — (CH ₂ ) ₆ —, m = 0)

<Catalyst>
(C-1): Tetra-n-butylphosphonium hydroxide 40% by weight aqueous solution (C-2): Tetraammonium hydroxide 27% by weight aqueous solution

<Solvent (for reaction) and solvent (for dilution)>
(S-1): Cyclohexanone

<Curing agent>
(D-1): “TBN-40C” (acid anhydride) manufactured by Shin Nippon Chemical Co., Ltd.

<Epoxy resin for compounding>
Hydrogenated bisphenol A type epoxy resin (trade name “YX8000”, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 198 g / equivalent)

[Manufacture and evaluation of epoxy resins and epoxy resin compositions]
<Examples 1-1 to 1-6 and Comparative Examples 1-1 to 1-3>
With the formulation shown in Table 1, a bifunctional epoxy resin, a divalent hydroxyl group-containing compound, a catalyst and a solvent were placed in a pressure-resistant reaction vessel equipped with a stirrer, and reacted at 145 ° C. for 7 hours in a nitrogen gas atmosphere. After removing the solvent from the reaction product by a conventional method, the obtained epoxy resin was analyzed. The results are shown in Table-1.

<Examples 2-1 to 2-6 and Comparative Examples 2-1 to 2-3>
The epoxy resin obtained in each of Examples 1-1 to 1-6 and Comparative Examples 1-1 to 1-3 with the formulation shown in Table-2 was 40% solid content (cyclohexanone: methyl ethyl ketone = 1: 1 [weight] Ratio]), an epoxy resin for blending, and a curing agent were added, and the following additives were added and stirred well to obtain an epoxy resin composition.

<Additives>
Antioxidant (“BHT” manufactured by Tokyo Chemical Industry Co., Ltd.): 0.013 parts by weight Antioxidant (“135A” manufactured by Adeka): 0.013 parts by weight Catalyst (“PX-4MP” manufactured by Nippon Chemical Industry Co., Ltd.): 0.0032 parts by weight leveling agent (“Surflon S-651” manufactured by AGC Seimi Chemical Co.): 0.0408 parts by weight

  The obtained epoxy resin composition was evaluated for transparency, UV resistance, film-forming property, and flexibility by the methods described above. The results are shown in Table-2.

[Evaluation results (low molecular weight epoxy resin)]
From the result of Table-2, the epoxy resin composition of Example 2-1 to Example 2-6 obtained using the epoxy resin of the present invention was Comparative Example 2-1 in which the epoxy resin of the present invention was not used. -It turns out that it is what was excellent in the balance of transparency and UV resistance compared with each of the epoxy resin composition of Comparative Example 2-2. Moreover, it turns out that the reactivity is higher than Comparative Example 2-3 which does not contain an aromatic ring structure, and the film-forming property is good.
Further, Examples 2-4 to 2-6 are excellent in flexibility in addition to the above characteristics, and Examples 2-3 and 2-6 are particularly excellent in UV resistance. Examples 2-5 and 2-6 Is particularly excellent in transparency.

  The epoxy resin of the present invention and the epoxy resin composition containing the epoxy resin have sufficient film-forming properties to be applied to processes such as film molding and coating, and are excellent in transparency, UV resistance and flexibility. It can be applied to various fields such as adhesives, paints, optical members, civil engineering materials, and insulating materials for electrical and electronic parts. In particular, it is useful as a laminated material, a sealing material, etc. in an optical member. As an example of the use of the epoxy resin of the present invention and the epoxy resin composition containing the epoxy resin, a sealing material for organic EL, a semiconductor sealing material, an underfill material, an interchip fill for 3D-LSI, a die bonding material, and a film shape Adhesives, adhesives such as liquid adhesives, multilayer printed wiring boards, laminates for electrical and electronic circuits such as capacitors, insulating sheets, prepregs, heat dissipation boards, or adhesive improvers for optical applications, etc. It is not limited to these.

Claims (15)

An epoxy resin represented by the following formula (1), having an epoxy equivalent of 200 g / equivalent or more and 30,000 g / equivalent or less.

(In the formula (1), at least one of A is either a chemical structure represented by the following formula (2) or a chemical structure represented by the following formula (3) (hereinafter referred to as “chemical structure A1”). Or a divalent group having a chemical structure represented by the following formula (4) (hereinafter referred to as “chemical structure A2”). The formula (1) represents the chemical structure A1 and the chemical structure A2. R is a hydrogen atom or a group represented by the following formula (5), formula (1) includes at least one group represented by formula (5), and n is a number from 1 to 500. is there.)

(In Formula (2), R ¹ and R ² may be the same or different from each other, and are a divalent hydrocarbon group having 2 to 20 carbon atoms, and m is a number of 0 or more and 30 or less. .)

(In the formula (3), ^{R 3} is a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms, ^{R 4} is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms.)

(In Formula (4), R < ⁵ > -R < ⁸ > may mutually be same or different, and is a hydrogen atom or a C1-C6 hydrocarbon group, and R < ⁹ > is C2-C12 fat. A cyclic or aliphatic hydrocarbon group, or a halogenated hydrocarbon group having 1 to 12 carbon atoms, and R ¹⁰ is a hydrogen atom, a hydrocarbon group having 1 to 3 carbon atoms, or a halogenated carbon atom having 1 to 3 carbon atoms. It is a hydrogen group, and R ⁹ and R ¹⁰ may be bonded to each other to form a ring.)

  The epoxy resin according to claim 1, wherein the chemical structure represented by the formula (2) is contained in the formula (1) in an amount of 0.1 to 100 mol% with respect to the entire chemical structure A1.   The epoxy resin according to claim 1 or 2, wherein the molar ratio of the chemical structure A1 and the chemical structure A2 in the formula (1) is 1/99 to 99/1.   The epoxy resin according to any one of claims 1 to 3, wherein the chemical structure represented by the formula (3) includes a hydrogenated bisphenol A type structure and / or a hydrogenated bisphenol F type structure.   The epoxy resin according to any one of claims 1 to 4, wherein m in the formula (2) is 0.   The epoxy resin according to any one of claims 1 to 5, wherein the weight average molecular weight is 1,000 to 100,000.   An epoxy resin composition comprising the epoxy resin according to any one of claims 1 to 6 and a curing agent.   The epoxy resin composition of Claim 7 which contains 0.1-100 weight part of hardening | curing agents with respect to 100 weight part of said epoxy resins.   The hardener is at least one selected from the group consisting of phenolic hardeners, amide hardeners, amine hardeners, imidazoles, acid anhydride hardeners, and organic phosphines. The epoxy resin composition described in 1.   The sealing material for electrical / electronic circuits which consists of an epoxy resin composition of any one of Claims 7 thru | or 9.   The laminated board for electrical / electronic circuits which consists of an epoxy resin composition of any one of Claims 7 thru | or 9.   An optical member comprising the epoxy resin composition according to any one of claims 7 to 9.   An adhesive comprising the epoxy resin composition according to any one of claims 7 to 9.   A paint comprising the epoxy resin composition according to any one of claims 7 to 9.   Hardened | cured material formed by hardening | curing the epoxy resin composition of any one of Claims 7 thru | or 9.