JP2014101449A - Phenoxy resin, curable resin composition, cured product thereof, prepreg, circuit board and buildup film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a phenoxy resin which is excellent in heat resistance and low both in the dielectric constant and the dielectric loss tangent.SOLUTION: There is provided a phenoxy resin having a structural moiety represented by the following formula which is obtained by reacting a biphenol having an aralkyl substituent and a bifunctional epoxy compound.

Description

  The present invention is a phenoxy resin having excellent heat resistance, low dielectric constant and dielectric loss tangent, low viscosity when varnished and easy to handle, epoxy resin composition containing the same, cured product, prepreg , Circuit board, and build-up film.

  Epoxy resin compositions containing an epoxy resin and a curing agent as an essential component exhibit excellent heat resistance and insulation in the cured product, and are widely used in electronic component applications such as semiconductors and multilayer printed boards. . Among these, in the technical field of multilayer printed circuit boards, development of multilayer printed wiring boards by a new manufacturing method such as a build-up method is advancing as a new technology that enables electronic devices to be made thinner, lighter and more functional. In the build-up method, an interlayer insulating film obtained by filming an epoxy resin composition as an insulating material is used, but a general epoxy resin composition has insufficient film-forming properties and film flexibility when filmed, A technique for adding a phenoxy resin to impart these performances is known (see Patent Document 1 below).

  However, a general phenoxy resin such as the high molecular weight bisphenol A type epoxy resin described in Patent Document 1 has insufficient heat resistance and dielectric properties, so that it can be added to the epoxy resin composition. In such a case, these performances are reduced. In addition, the conventional phenoxy resin has a high viscosity when diluted with an organic solvent, and requires a large amount of solvent for viscosity adjustment when mixed with the epoxy resin composition. Therefore, as a phenoxy resin that can be suitably used for multilayer printed circuit board applications, the epoxy resin composition itself has excellent heat resistance, low dielectric constant and dielectric loss tangent, and low viscosity when diluted with an organic solvent. Development of a phenoxy resin that can be easily added to a product, and the realization of an epoxy resin composition that contains this, has high film-forming properties, and is excellent in flexibility, heat resistance, and dielectric properties in a cured product are required. It was.

  Examples of the phenoxy resin excellent in film forming property, flexibility, heat resistance, etc. include 4,4′-biphenol type epoxy resin, 3,3 ′, 5,5′-tetramethyl-4,4′-biphenol type epoxy. A high molecular weight epoxy resin having an epoxy equivalent of 8,150 g / equivalent obtained by reacting a resin and 3,3′-dimethyl-4,4′-biphenol is known (see Patent Document 2 below). Such a high molecular weight epoxy resin has higher heat resistance than the conventional phenoxy resin, but does not satisfy the recent required performance, and its dielectric constant and dielectric loss tangent were not sufficiently low. Therefore, when this is added to an epoxy resin composition and used, these performances are lowered. Furthermore, since the high molecular weight epoxy resin has a high viscosity when diluted with an organic solvent, it is necessary to adjust the viscosity using a large amount of solvent when used by adding to the epoxy resin composition.

JP-A-9-67555 JP 2012-107215 A

  Therefore, the problem to be solved by the present invention is a phenoxy resin that is excellent in heat resistance, has a low dielectric constant and dielectric loss tangent, has a low viscosity when diluted with an organic solvent, and is easy to handle. It is to provide an epoxy resin composition that contains, has high film-forming properties, and is excellent in flexibility, heat resistance, and dielectric properties in a cured product, its cured product, prepreg, circuit board, and build-up film. .

  As a result of intensive studies to solve the above problems, the present inventors have found that the following structural formula (I)

（式中、Ｒ^１はそれぞれ独立して炭素原子数１〜６のアルキル基又は炭素原子数１〜６のアルコキシ基の何れかであり、Ｒ^２はそれぞれ独立して水素原子、炭素原子数１〜６のアルキル基、又は炭素原子数１〜６のアルコキシ基の何れかであり、Ａｒはそれぞれ独立してフェニレン基、ナフチレン基、或いはこれらの芳香核上に炭素原子数１〜６のアルキル基又は炭素原子数１〜６のアルコキシ基を１乃至複数個有する構造部位の何れかであり、ｍはそれぞれ独立して１又は２であり、ｎはそれぞれ独立して０〜２の整数であり、かつ、２つのｎのうち少なくとも一方は１又は２である。）
で表される構造部位を有するフェノキシ樹脂は、耐熱性に優れ、誘電率及び誘電正接が共に低く、更に、有機溶剤で希釈した際の粘度が低く扱いが容易であり、これを含有するエポキシ樹脂組成物は製膜性が高く、かつ、硬化物における可撓性、耐熱性、誘電特性にも優れることを見出し、本発明を完成するに至った。

(In the formula, each R ¹ is independently an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and R ² is independently a hydrogen atom or 1 carbon atom. Or an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and Ar is independently a phenylene group, a naphthylene group, or an alkyl group having 1 to 6 carbon atoms on the aromatic nucleus. Or any one of structural parts having 1 to a plurality of alkoxy groups having 1 to 6 carbon atoms, m is each independently 1 or 2, n is each independently an integer of 0 to 2, And at least one of two n is 1 or 2.)
The phenoxy resin having the structural part represented by the formula is excellent in heat resistance, low in dielectric constant and dielectric loss tangent, and low in viscosity when diluted with an organic solvent, and easy to handle, and an epoxy resin containing this It has been found that the composition has high film-forming properties and is excellent in flexibility, heat resistance, and dielectric properties in the cured product, and the present invention has been completed.

  That is, the present invention is a phenoxy resin obtained by reacting a bifunctional phenol compound (a) and a bifunctional epoxy compound (b) as essential raw materials, and the bifunctional phenol compound (a) has the following structure: Formula (1)

（式中、Ｒ^１はそれぞれ独立して炭素原子数１〜６のアルキル基又は炭素原子数１〜６のアルコキシ基の何れかであり、Ｒ^２はそれぞれ独立して水素原子、炭素原子数１〜６のアルキル基、又は炭素原子数１〜６のアルコキシ基の何れかであり、Ａｒはそれぞれ独立してフェニレン基、ナフチレン基、或いはこれらの芳香核上に炭素原子数１〜６のアルキル基又は炭素原子数１〜６のアルコキシ基を１乃至複数個有する構造部位の何れかであり、ｍはそれぞれ独立して１又は２であり、ｎはそれぞれ独立して０〜２の整数であり、かつ、２つのｎのうち少なくとも一方は１又は２である。）
で表されるビフェノール化合物（Ａ）を用いることを特徴とするフェノキシ樹脂に関する。

(In the formula, each R ¹ is independently an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and R ² is independently a hydrogen atom or 1 carbon atom. Or an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and Ar is independently a phenylene group, a naphthylene group, or an alkyl group having 1 to 6 carbon atoms on the aromatic nucleus. Or any one of structural parts having 1 to a plurality of alkoxy groups having 1 to 6 carbon atoms, m is each independently 1 or 2, n is each independently an integer of 0 to 2, And at least one of two n is 1 or 2.)
The phenoxy resin characterized by using the biphenol compound (A) represented by these.

  The present invention further relates to a phenoxy resin obtained by reacting a bifunctional phenol compound (a) and a bifunctional epoxy compound (b) as essential raw materials, wherein the bifunctional epoxy compound (b) has the following structural formula: (2)

（式中、Ｒ^１はそれぞれ独立して炭素原子数１〜６のアルキル基又は炭素原子数１〜６のアルコキシ基の何れかであり、Ｒ^２はそれぞれ独立して水素原子、炭素原子数１〜６のアルキル基、又は炭素原子数１〜６のアルコキシ基の何れかであり、Ａｒはそれぞれ独立してフェニレン基、ナフチレン基、或いはこれらの芳香核上に炭素原子数１〜６のアルキル基又は炭素原子数１〜６のアルコキシ基を１乃至複数個有する構造部位の何れかであり、Ｇはグリシジル基を表し、ｍはそれぞれ独立して１又は２であり、ｎはそれぞれ独立して０〜２の整数であり、かつ、２つのｎのうち少なくとも一方は１又は２である。）
で表される２官能エポキシ化合物（Ｂ）を用いることを特徴とするフェノキシ樹脂に関する。

(In the formula, each R ¹ is independently an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and R ² is independently a hydrogen atom or 1 carbon atom. Or an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and Ar is independently a phenylene group, a naphthylene group, or an alkyl group having 1 to 6 carbon atoms on the aromatic nucleus. Or any one of structural parts having one or more alkoxy groups having 1 to 6 carbon atoms, G represents a glycidyl group, m is each independently 1 or 2, and n is each independently 0 And an integer of ˜2, and at least one of the two n is 1 or 2.)
It is related with the phenoxy resin characterized by using the bifunctional epoxy compound (B) represented by these.

  The present invention further relates to a curable resin composition containing the phenoxy resin, an epoxy resin, and a curing agent for epoxy resin.

  The present invention further relates to a cured product obtained by curing the phenoxy resin or the curable resin composition.

  The present invention further relates to a prepreg obtained by impregnating a reinforcing substrate with a solution obtained by diluting the curable resin composition in an organic solvent and semi-curing the resulting impregnated substrate.

  The present invention further relates to a circuit board obtained by obtaining a varnish obtained by diluting the curable resin composition in an organic solvent, and heating and press-molding a varnish shaped into a plate shape and a copper foil.

  The present invention further relates to a build-up film obtained by applying a solution obtained by diluting the curable resin composition in an organic solvent on a base film and drying it.

  According to the present invention, a phenoxy resin having excellent heat resistance, low dielectric constant and dielectric loss tangent, low viscosity when diluted with an organic solvent, and easy handling, containing the phenoxy resin, It is possible to provide an epoxy resin composition that is high in flexibility and has excellent flexibility, heat resistance, and dielectric properties in a cured product, a cured product thereof, a prepreg, a circuit board, and a buildup film.

1 is a GPC chart of the biphenol compound (A) obtained in Production Example 1. FIG. FIG. 2 is a GPC chart of the bifunctional epoxy compound (B) obtained in Production Example 2. FIG. 3 is a GPC chart of the phenoxy resin (1) obtained in Example 1. FIG. 4 is a GPC chart of the phenoxy resin (2) obtained in Example 2. FIG. 5 is a GPC chart of the phenoxy resin (3) obtained in Example 3. FIG. 6 is a GPC chart of the phenoxy resin (4) obtained in Example 4. FIG. 7 is a GPC chart of the phenoxy resin (5) obtained in Example 5.

Hereinafter, the present invention will be described in detail.
The phenoxy resin of the present invention has the following structural formula (I) in its resin structure.

（式中、Ｒ^１はそれぞれ独立して炭素原子数１〜６のアルキル基又は炭素原子数１〜６のアルコキシ基の何れかであり、Ｒ^２はそれぞれ独立して水素原子、炭素原子数１〜６のアルキル基、又は炭素原子数１〜６のアルコキシ基の何れかであり、Ａｒはそれぞれ独立してフェニレン基、ナフチレン基、或いはこれらの芳香核上に炭素原子数１〜６のアルキル基又は炭素原子数１〜６のアルコキシ基を１乃至複数個有する構造部位の何れかであり、ｍはそれぞれ独立して１又は２であり、ｎはそれぞれ独立して０〜２の整数であり、かつ、２つのｎのうち少なくとも一方は１又は２である。）
で表される構造部位を有することを特徴とする。

(In the formula, each R ¹ is independently an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and R ² is independently a hydrogen atom or 1 carbon atom. Or an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and Ar is independently a phenylene group, a naphthylene group, or an alkyl group having 1 to 6 carbon atoms on the aromatic nucleus. Or any one of structural parts having 1 to a plurality of alkoxy groups having 1 to 6 carbon atoms, m is each independently 1 or 2, n is each independently an integer of 0 to 2, And at least one of two n is 1 or 2.)
It has the structure site | part represented by these.

  The phenoxy resin of the present invention has a structural portion represented by the structural formula (I) in the resin structure, so that the dielectric constant and dielectric loss tangent of the cured product are very low. Furthermore, a structural part having a high aromatic ring concentration, such as the structural formula (I), has an effect of improving the heat resistance of the phenoxy resin.

  More specifically, the phenoxy resin of the present invention has the following structural formula (II) on the aromatic nucleus in the phenoxy resin skeleton.

（式中、Ｒ^２はそれぞれ独立して水素原子、炭素原子数１〜６のアルキル基、又は炭素原子数１〜６のアルコキシ基の何れかであり、Ａｒはそれぞれ独立してフェニレン基、ナフチレン基、或いはこれらの芳香核上に炭素原子数１〜６のアルキル基又は炭素原子数１〜６のアルコキシ基を１乃至複数個有する構造部位の何れかである。）
で表される置換基を有する分子構造となる。一般に、嵩高い置換基を有する樹脂は有機溶剤に溶解してワニス化した際の粘度が高くなる傾向にあるが、本発明のフェノキシ樹脂はその芳香核上に前記構造式（ＩＩ）で表されるような嵩高い置換基を有するにも関わらず、ワニス化した際の粘度が低く扱い易い特徴を有する。

(In the formula, each R ² is independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms, and Ar is each independently a phenylene group or naphthylene. Or a structural site having one or more alkyl groups having 1 to 6 carbon atoms or alkoxy groups having 1 to 6 carbon atoms on these aromatic nuclei.)
It becomes the molecular structure which has a substituent represented by. In general, a resin having a bulky substituent tends to increase in viscosity when dissolved in an organic solvent and varnished. However, the phenoxy resin of the present invention is represented by the structural formula (II) on the aromatic nucleus. In spite of having such a bulky substituent, it has a low viscosity when it is varnished and is easy to handle.

  More specifically, the pheny resin of the present invention is a phenoxy resin obtained by reacting the bifunctional phenol compound (a) and the bifunctional epoxy compound (b) as essential raw materials, The following structural formula (1) as the bifunctional phenol compound (a)

（式中、Ｒ^１はそれぞれ独立して炭素原子数１〜６のアルキル基又は炭素原子数１〜６のアルコキシ基の何れかであり、Ｒ^２はそれぞれ独立して水素原子、炭素原子数１〜６のアルキル基、又は炭素原子数１〜６のアルコキシ基の何れかであり、Ａｒはそれぞれ独立してフェニレン基、ナフチレン基、或いはこれらの芳香核上に炭素原子数１〜６のアルキル基又は炭素原子数１〜６のアルコキシ基を１乃至複数個有する構造部位の何れかであり、ｍはそれぞれ独立して１又は２であり、ｎはそれぞれ独立して０〜２の整数であり、かつ、２つのｎのうち少なくとも一方は１又は２である。）
で表されるビフェノール化合物（Ａ）を用いて得られるフェノキシ樹脂（Ｘ１）、又は、２官能フェノール化合物（ａ）と、２官能エポキシ化合物（ｂ）とを必須の原料として反応させて得られるフェノキシ樹脂であって、前記２官能エポキシ化合物（ｂ）として下記構造式（２）

(In the formula, each R ¹ is independently an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and R ² is independently a hydrogen atom or 1 carbon atom. Or an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and Ar is independently a phenylene group, a naphthylene group, or an alkyl group having 1 to 6 carbon atoms on the aromatic nucleus. Or any one of structural parts having 1 to a plurality of alkoxy groups having 1 to 6 carbon atoms, m is each independently 1 or 2, n is each independently an integer of 0 to 2, And at least one of two n is 1 or 2.)
A phenoxy resin (X1) obtained using a biphenol compound (A) represented by the formula: or a phenoxy obtained by reacting a bifunctional phenol compound (a) and a bifunctional epoxy compound (b) as essential raw materials A resin having the following structural formula (2) as the bifunctional epoxy compound (b):

（式中、Ｒ^１はそれぞれ独立して炭素原子数１〜６のアルキル基又は炭素原子数１〜６のアルコキシ基の何れかであり、Ｒ^２はそれぞれ独立して水素原子、炭素原子数１〜６のアルキル基、又は炭素原子数１〜６のアルコキシ基の何れかであり、Ａｒはそれぞれ独立してフェニレン基、ナフチレン基、或いはこれらの芳香核上に炭素原子数１〜６のアルキル基又は炭素原子数１〜６のアルコキシ基を１乃至複数個有する構造部位の何れかであり、Ｇはグリシジル基を表し、ｍはそれぞれ独立して１又は２であり、ｎはそれぞれ独立して０〜２の整数であり、かつ、２つのｎのうち少なくとも一方は１又は２である。）
で表される２官能エポキシ化合物（Ｂ）を用いて得られるフェノキシ樹脂（Ｘ２）が挙げられる。

(In the formula, each R ¹ is independently an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and R ² is independently a hydrogen atom or 1 carbon atom. Or an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and Ar is independently a phenylene group, a naphthylene group, or an alkyl group having 1 to 6 carbon atoms on the aromatic nucleus. Or any one of structural parts having one or more alkoxy groups having 1 to 6 carbon atoms, G represents a glycidyl group, m is each independently 1 or 2, and n is each independently 0 And an integer of ˜2, and at least one of the two n is 1 or 2.)
The phenoxy resin (X2) obtained using the bifunctional epoxy compound (B) represented by these is mentioned.

  First, the phenoxy resin (X1) will be described. The biphenol compound (A) used as a raw material for the phenoxy resin (X1) has the following structural formula (1):

（式中、Ｒ^１はそれぞれ独立して炭素原子数１〜６のアルキル基又は炭素原子数１〜６のアルコキシ基の何れかであり、Ｒ^２はそれぞれ独立して水素原子、炭素原子数１〜６のアルキル基、又は炭素原子数１〜６のアルコキシ基の何れかであり、Ａｒはそれぞれ独立してフェニレン基、ナフチレン基、或いはこれらの芳香核上に炭素原子数１〜６のアルキル基又は炭素原子数１〜６のアルコキシ基を１乃至複数個有する構造部位の何れかであり、ｍはそれぞれ独立して１又は２であり、ｎはそれぞれ独立して０〜２の整数であり、かつ、２つのｎのうち少なくとも一方は１又は２である。）
で表されるものである。

(In the formula, each R ¹ is independently an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and R ² is independently a hydrogen atom or 1 carbon atom. Or an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and Ar is independently a phenylene group, a naphthylene group, or an alkyl group having 1 to 6 carbon atoms on the aromatic nucleus. Or any one of structural parts having 1 to a plurality of alkoxy groups having 1 to 6 carbon atoms, m is each independently 1 or 2, n is each independently an integer of 0 to 2, And at least one of two n is 1 or 2.)
It is represented by

In the structural formula (1), each R ¹ is independently an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and has excellent heat resistance when formed into a film. R ¹ is preferably a methyl group, an ethyl group, a methoxy group, or an ethoxy group, and more preferably a methyl group, since the dielectric constant and dielectric loss tangent thereof are lower.

In the structural formula (1), each R ² is independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. R ² is preferably any one of a hydrogen atom, a methyl group, an ethyl group, a methoxy group, and an ethoxy group, and more preferably a hydrogen atom, since the dielectric constant and the dielectric loss tangent are lower.

  In the structural formula (1), each Ar independently represents a phenylene group, a naphthylene group, or an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms on the aromatic nucleus. Although it is one of the structural parts having a plurality, it is excellent in heat resistance when formed into a film, has a lower dielectric constant and dielectric loss tangent, and further has a low viscosity when formed into a varnish. , A phenylene group or a naphthylene group is preferable, and a phenylene group is more preferable.

  Therefore, the biphenol compound (A) has the following structural formula (1-1):

（式中、ｍはそれぞれ独立して１又は２であり、ｎはそれぞれ独立して０〜２の整数であり、かつ、２つのｎのうち少なくとも一方は１又は２である。）
で表されるビフェノール化合物（Ａ−１）であることがより好ましい。

(In the formula, m is each independently 1 or 2, n is each independently an integer of 0 to 2, and at least one of the two n is 1 or 2.)
It is more preferable that it is a biphenol compound (A-1) represented by these.

  The method for producing the biphenol compound (A) is, for example, the following structural formula (III)

（式中、Ｒ^１はそれぞれ独立して炭素原子数１〜６のアルキル基又は炭素原子数１〜６のアルコキシ基の何れかである。）
で表されるビフェノール化合物（ａ１）と、アラルキル化剤（ａ２）とを、酸触媒の存在下、１００〜１８０℃の温度条件で３〜１０時間反応させる方法が挙げられる。

(In the formula, each R ¹ is independently an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms.)
And a method in which the aralkylating agent (a2) is reacted for 3 to 10 hours at a temperature of 100 to 180 ° C. in the presence of an acid catalyst.

Examples of the biphenol compound (a1) include 3,3 ′, 5,5′-tetramethyl-4,4′-biphenol, 3,3 ′, 5,5′-tetraethyl-4,4′-biphenol, 3 , 3 ′, 5,5′-tetraisopropyl-4,4′-biphenol and the like. These may be used alone or in combination of two or more. Among them, since the resulting phenoxy resin is excellent in heat resistance when formed into a film and has a lower dielectric constant and dielectric loss tangent, R ¹ is any of a methyl group, an ethyl group, a methoxy group, or an ethoxy group, respectively. It is preferable that it is a methyl group.

  Examples of the aralkylating agent (a2) include a phenylmethanol compound, a phenylmethyl halide compound, a naphthylmethanol compound, a naphthylmethyl halide compound, and a styrene compound. Specifically, benzyl chloride, benzyl bromide, benzyl iodide, o-methylbenzyl chloride, m-methylbenzyl chloride, p-methylbenzyl chloride, p-ethylbenzyl chloride, p-isopropylbenzyl chloride, p-tert-butyl Benzyl chloride, p-phenylbenzyl chloride, 5-chloromethylacenaphthylene, 2-naphthylmethyl chloride, 1-chloromethyl-2-naphthalene and their nuclear substituted isomers, α-methylbenzyl chloride, α, α-dimethyl Benzyl chloride, benzyl methyl ether, o-methyl benzyl methyl ether, m-methyl benzyl methyl ether, p-methyl benzyl methyl ether, p-ethyl benzyl methyl ether and their nuclear substitution isomerism , Benzyl ethyl ether, benzyl propyl ether, benzyl isobutyl ether, benzyl n-butyl ether, p-methylbenzyl methyl ether and their nuclear substitution isomers, benzyl alcohol, o-methylbenzyl alcohol, m-methylbenzyl alcohol, p-methyl Benzyl alcohol, p-ethylbenzyl alcohol, p-isopropylbenzyl alcohol, ptert-butylbenzyl alcohol, p-phenylbenzyl alcohol, α-naphthylmethanol and their nuclear substituted isomers, α-methylbenzyl alcohol, α, α-dimethyl Examples include benzyl alcohol, styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, α-methyl styrene, β-methyl styrene and the like. These may be used alone or in combination of two or more.

  Among these, the phenoxy resin obtained has excellent heat resistance, lower dielectric constant and dielectric loss tangent, and lower viscosity when varnished, so that benzyl chloride, benzyl bromide, or benzyl Alcohol is preferred.

  Since the reaction rate of the biphenol compound (a1) and the aralkylating agent (a2) can easily adjust the values of m and n in the structural formula (1), the biphenol compound (a1) It is preferable that it is the ratio from which the said aralkylation agent (a2) becomes the range of 1-4 mol with respect to 1 mol. Especially, since it becomes a phenoxy resin having a lower viscosity when varnished, the proportion of the aralkylating agent (a2) in the range of 1.5 to 2.5 mol relative to 1 mol of the biphenol compound (a1). It is preferable that

  Examples of the acid catalyst used when the biphenol compound (a1) and the aralkylating agent (a2) are reacted include inorganic acids such as phosphoric acid, sulfuric acid and hydrochloric acid, oxalic acid, benzenesulfonic acid, toluenesulfonic acid, Examples thereof include organic acids such as methanesulfonic acid and fluoromethanesulfonic acid, and Friedel-Crafts catalysts such as aluminum chloride, zinc chloride, stannic chloride, ferric chloride, and diethylsulfuric acid.

  The amount of these acid catalysts used can be appropriately selected depending on the desired aralkylation rate and the like, but when using an inorganic acid or an organic acid, 0.01 to 5.0 parts by mass with respect to 100 parts by mass of the reaction raw material. When using the Friedel-Crafts catalyst in the range, it is preferably used in the range of 0.2 to 3.0 mol with respect to 1 mol of the aralkylating agent (a2).

  The reaction between the biphenol compound (a1) and the aralkylating agent (a2) may be performed in an organic solvent as necessary. Examples of the organic solvent used herein include ketone solvents such as acetone, methyl ethyl ketone, and cyclohexanone, acetate solvents such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate, cellosolve, butyl carbitol, and the like. Examples thereof include carbitol solvents, aromatic hydrocarbon solvents such as toluene and xylene, dimethylformamide, dimethylacetamide, N-methylpyrrolidone and the like.

  After completion of the reaction, it is preferable to neutralize the reaction mixture and then wash the product biphenol compound (A) with water.

  The phenoxy resin (X1) is obtained using the biphenol compound (A) thus obtained as an essential raw material component. The bifunctional phenol compound (a) used as a raw material for the phenoxy resin (X1) is such that the obtained phenoxy resin is excellent in heat resistance, has a lower dielectric constant and dielectric loss tangent, and has a viscosity when varnished. The biphenol compound (A) is preferably used alone because it is low. For example, the biphenol compound is used for the purpose of adjusting heat resistance, elasticity, and elongation in a cured product of the obtained phenoxy resin (X1). In addition to (A), other bifunctional phenol compounds (A ′) may be used.

  Other bifunctional phenol compounds (A ′) used here are, for example, 2,2′-biphenol, 2,3′-biphenol, 2,4′-biphenol, 3,3′-biphenol, 3,4′- Biphenol, 4,4′-biphenol, 2-methyl-4,4′-biphenol, 3-methyl-4,4′-biphenol, 2,2′-dimethyl-4,4′-biphenol, 3,3′- Dimethyl-4,4′-biphenol, 3,3 ′, 5,5′-tetramethyl-4,4′-biphenol, 2,2 ′, 3,3 ′, 5,5′-hexamethyl-4,4 ′ -Biphenol compounds such as biphenol, 2,2 ', 3,3', 5,5 ', 6,6'-octamethyl-4,4'-biphenol, 4,4'-dihydroxydiphenyl ether, 4,4'- Dihydroxy diphe Rusulfide, hydroquinone, resorcin, catechol, 1,6'-dihydroxynaphthalene, 2,7'-dihydroxynaphthalene, 2,6'-dihydroxynaphthalene, 1,4'-dihydroxynaphthalene, bisphenol A, bisphenol B, bisphenol F, bisphenol Examples thereof include bisphenol compounds such as S and bisphenol AD. These may be used alone or in combination of two or more. Among them, since the obtained phenoxy resin is excellent in heat resistance and has a lower dielectric constant and dielectric loss tangent, bisphenol A or 3,3 ′, 5,5′-tetramethyl-4,4′-biphenol is used. preferable. When using these, it is preferable that the quantity is the range of 5-50 mass parts in the total 100 mass parts of the said biphenol compound (A) and another bifunctional phenol compound (A ').

  The bifunctional epoxy compound (b) used as a raw material for the phenoxy resin (X1) is, for example, the other bifunctional compound other than the bifunctional epoxy compound (B) obtained by diglycidyl etherification of the biphenol compound (A). 2,2′-biphenol, 2,3′-biphenol, 2,4′-biphenol, 3,3′-biphenol, 3,4′-biphenol, 4,4′-biphenol cited as the phenol compound (A ′) 2-methyl-4,4′-biphenol, 3-methyl-4,4′-biphenol, 2,2′-dimethyl-4,4′-biphenol, 3,3′-dimethyl-4,4′-biphenol 3,3 ′, 5,5′-tetramethyl-4,4′-biphenol, 2,2 ′, 3,3 ′, 5,5′-hexamethyl-4,4′-biphenol, 2, Biphenol compounds such as', 3,3 ', 5,5', 6,6'-octamethyl-4,4'-biphenol, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl sulfide, hydroquinone, Resorcin, catechol, 1,6′-dihydroxynaphthalene, 2,7′-dihydroxynaphthalene, 2,6′-dihydroxynaphthalene, 1,4′-dihydroxynaphthalene, bisphenol A, bisphenol B, bisphenol F, bisphenol S, bisphenol AD And diglycidyl ethers of bisphenol compounds such as These may be used alone or in combination of two or more. Among these, since the cured product has excellent heat resistance and lower dielectric constant and dielectric loss tangent, the bifunctional epoxy compound (B) obtained by diglycidyl etherification of the biphenol compound (A) and bisphenol A Diglycidyl ether or diglycidyl ether of 3,3 ′, 5,5′-tetramethyl-4,4′-biphenol is preferable, and since the viscosity when varnished is low, the biphenol compound ( A bifunctional epoxy compound (B) obtained by diglycidyl etherification of A) or diglycidyl ether of bisphenol A is preferred.

  Here, the production method of the bifunctional epoxy compound (B) obtained by diglycidyl etherification of the biphenol compound (A) is, for example, the above-described biphenol compound (A) and epihalohydrin in the presence of a basic catalyst. The method of making it react for 0.5 to 10 hours at the temperature of -120 degreeC is mentioned.

  The epihalohydrin used here is not particularly limited, and examples thereof include epichlorohydrin, epibromohydrin, β-methylepichlorohydrin, and the like. Of these, epichlorohydrin is preferred because it is easily available industrially. Moreover, these reaction ratios at the time of making the said biphenol compound (A) and epichlorohydrin react are ratios which become epihalohydrin 2-10 mol with respect to 1 mol of the phenolic hydroxyl group which the said biphenol compound (A) has. It is preferable.

  Examples of the basic catalyst used in the reaction of the biphenol compound (A) and epihalohydrin include alkaline earth metal hydroxides, alkali metal carbonates, alkali metal hydroxides, and the like, and particularly hydroxylation excellent in catalytic activity. Alkali metal hydroxides such as sodium and potassium hydroxide are preferred. These may be used in a solid form or in the form of an aqueous solution of about 10 to 55% by mass. The amount of the basic catalyst used is in the range of 0.9 to 2.0 mol with respect to 1 mol of the phenolic hydroxyl group, and may be added all at once, or may be added or gradually added. When the basic catalyst is used as an aqueous solution, it is continuously added, and water and epihalohydrin are continuously distilled from the reaction mixture under reduced pressure or normal pressure, and further separated to remove water and the epihalohydrin is removed. A method of continuously returning to the reaction mixture may also be used.

  In industrial production, the epihalohydrin used in the initial batch of diglycidyl ether production is all new, but the subsequent batch is consumed by the reaction with epihalohydrins recovered from the crude reaction product. It is preferable to use in combination with new epihalohydrins corresponding to the amount disappeared.

  The reaction rate of the biphenol compound (A) and epihalohydrin can be increased by carrying out the reaction in an organic solvent. The organic solvent used here is not particularly limited. For example, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, aromatic hydrocarbon solvents such as toluene and xylene, methanol, ethanol, 1-propyl alcohol, and isopropyl alcohol. Alcohol solvents such as 1-butanol, secondary butanol and tertiary butanol, cellosolve solvents such as methyl cellosolve and ethyl cellosolve, ether solvents such as tetrahydrofuran, 1,4-dioxane, 1,3-dioxane and diethoxyethane, acetonitrile And aprotic polar solvents such as dimethyl sulfoxide and dimethylformamide. These organic solvents may be used alone or in combination of two or more kinds in order to adjust the polarity.

  After completion of the reaction, the reaction product is washed with water, and unreacted epihalohydrin and the combined organic solvent are distilled off by distillation under heating and reduced pressure. Further, in order to obtain an epoxy compound with less hydrolyzable halogen, unreacted epihalohydrin and the organic solvent used in combination are distilled off before the water washing step, and the resulting crude product is toluene, methyl isobutyl ketone, It can be redissolved in an organic solvent such as methyl ethyl ketone, and an aqueous solution of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide can be added for further reaction. At this time, a phase transfer catalyst such as a quaternary ammonium salt or crown ether may be present for the purpose of improving the reaction rate. When the phase transfer catalyst is used, the amount used is preferably 0.1 to 3.0 parts by mass with respect to 100 parts by mass of the crude epoxy product used. After completion of the additional reaction, the produced salt is removed by a method such as filtration or washing with water, and further, a solvent such as toluene and methyl isobutyl ketone is distilled off under reduced pressure by heating to obtain the desired bifunctional epoxy compound (B ) Can be obtained.

  As described above, the phenoxy resin (X1) contains the biphenol compound (A) as an essential component, and if necessary, the bifunctional phenol compound (a) containing the other bifunctional phenol compound (A ′); It is obtained by a method of reacting the bifunctional epoxy compound (b) in the presence of a catalyst at a temperature of 50 to 150 ° C. for 5 to 30 hours.

  Since the reaction ratio of the bifunctional phenol compound (a) and the bifunctional epoxy compound (b) can easily adjust the epoxy equivalent of the obtained phenoxy resin (X1) to a suitable range described later, It is preferable that the epoxy group contained in the bifunctional epoxy compound (b) is in a ratio of 1.0 to 1.2 moles with respect to 1 mole of the hydroxyl group contained in the bifunctional phenol compound (a).

  As the catalyst used for the reaction of the bifunctional phenol compound (a) and the bifunctional epoxy compound (b), any catalyst that is usually used for the reaction of an epoxy group and a phenolic hydroxyl group can be used. , Alkali metal compounds, organic phosphorus compounds such as triphenylphosphine, tertiary amines such as 1,8-diazabicyclo- [5.4.0] -undecene (DBU), 2-methylimidazole, 2-ethyl-4- Examples include imidazole compounds such as methylimidazole and 2-phenylimidazole, Lewis acids, and amine complex salts. Among them, an imidazole compound that has high catalytic activity and does not contain an alkali metal atom is preferable, and the amount of the catalyst used is 50 ppm to 50 ppm to the total mass of the bifunctional phenol compound (a) and the bifunctional epoxy compound (b). A range of 1000 ppm is preferred.

  The reaction of the bifunctional phenol compound (a) and the bifunctional epoxy compound (b) may be performed in the presence of an organic solvent, and is preferably performed in the presence of an organic solvent because the reactivity is increased. At this time, the amount of the organic solvent used is preferably in the range where the non-volatile content is 50 to 90%.

  Examples of the organic solvent used here include aromatic compounds such as benzene, toluene, xylene, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, Amide solvents such as N-methylacetamide, N, N-dimethylacetamide, 2-pyrrolidone, N-methylpyrrolidone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol mono Ethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n- Chirueteru, diethylene glycol dimethyl ether, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol mono -n- butyl ether, etc. glycol ethers solvents such as propylene glycol monomethyl ether acetate. Of these, ketone solvents are preferred because of the excellent solubility of the resulting phenoxy resin (X1).

  The phenoxy resin (X1) thus obtained is excellent in heat resistance when formed into a film and has a lower dielectric constant and dielectric loss tangent, so that the epoxy equivalent is 5,000 to 40,000 g / equivalent. It is preferable that it is the range of 9,000-35,000 g / equivalent.

  Next, the phenoxy resin (X2) will be described. The bifunctional epoxy compound (B) used as a raw material for the phenoxy resin (X2) has the following structural formula (2).

（式中、Ｒ^１はそれぞれ独立して炭素原子数１〜６のアルキル基又は炭素原子数１〜６のアルコキシ基の何れかであり、Ｒ^２はそれぞれ独立して水素原子、炭素原子数１〜６のアルキル基、又は炭素原子数１〜６のアルコキシ基の何れかであり、Ａｒはそれぞれ独立してフェニレン基、ナフチレン基、或いはこれらの芳香核上に炭素原子数１〜６のアルキル基又は炭素原子数１〜６のアルコキシ基を１乃至複数個有する構造部位の何れかであり、Ｇはグリシジル基を表し、ｍはそれぞれ独立して１又は２であり、ｎはそれぞれ独立して０〜２の整数であり、かつ、２つのｎのうち少なくとも一方は１又は２である。）
で表されるものであり、即ち、前記した前記ビフェノール化合物（Ａ）をジグリシジルエーテル化して得られる２官能エポキシ化合物（Ｂ）に相当する。

(In the formula, each R ¹ is independently an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and R ² is independently a hydrogen atom or 1 carbon atom. Or an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and Ar is independently a phenylene group, a naphthylene group, or an alkyl group having 1 to 6 carbon atoms on the aromatic nucleus. Or any one of structural parts having one or more alkoxy groups having 1 to 6 carbon atoms, G represents a glycidyl group, m is each independently 1 or 2, and n is each independently 0 And an integer of ˜2, and at least one of the two n is 1 or 2.)
That is, it corresponds to a bifunctional epoxy compound (B) obtained by diglycidyl etherification of the biphenol compound (A).

Preferable R ¹ , R ² , and Ar in the structural formula (2) are the same as those in the structural formula (1) representing the biphenol compound (A). Therefore, the bifunctional epoxy compound (B ) Is the following structural formula (2-1)

（式中、ｍはそれぞれ独立して１又は２であり、ｎはそれぞれ独立して０〜２の整数であり、かつ、２つのｎのうち少なくとも一方は１又は２である。）
で表される２官能エポキシ化合物（Ｂ−１）であることがより好ましい。

(In the formula, m is each independently 1 or 2, n is each independently an integer of 0 to 2, and at least one of the two n is 1 or 2.)
It is more preferable that it is a bifunctional epoxy compound (B-1) represented by these.

  The bifunctional epoxy compound (B) can be obtained by diglycidyl etherifying the biphenol compound (A) by the method described above.

  The phenoxy resin (X2) of the present invention is obtained using the bifunctional epoxy compound (B) as an essential raw material component. The bifunctional epoxy compound (b) used as a raw material for the phenoxy resin (X2) is such that the obtained phenoxy resin is excellent in heat resistance, has a lower dielectric constant and dielectric loss tangent, and has a viscosity when varnished. The bifunctional epoxy compound (B) is preferably used alone because it is low. For example, the purpose of improving the compatibility when the resulting phenoxy resin (X2) is mixed with an epoxy resin composition is used. The other bifunctional epoxy compound (B ′) may be used together with the bifunctional epoxy compound (A).

  Other bifunctional epoxy compounds (B ′) used here are, for example, 2,2′-biphenol, 2,3′-biphenol, 2,4′-biphenol, 3,3′-biphenol, 3,4′-. Biphenol, 4,4′-biphenol, 2-methyl-4,4′-biphenol, 3-methyl-4,4′-biphenol, 2,2′-dimethyl-4,4′-biphenol, 3,3′- Dimethyl-4,4′-biphenol, 3,3 ′, 5,5′-tetramethyl-4,4′-biphenol, 2,2 ′, 3,3 ′, 5,5′-hexamethyl-4,4 ′ -Biphenol compounds such as biphenol, 2,2 ', 3,3', 5,5 ', 6,6'-octamethyl-4,4'-biphenol, 4,4'-dihydroxydiphenyl ether, 4,4'- Dihydroxydiphenyl Rufide, hydroquinone, resorcin, catechol, 1,6'-dihydroxynaphthalene, 2,7'-dihydroxynaphthalene, 2,6'-dihydroxynaphthalene, 1,4'-dihydroxynaphthalene, bisphenol A, bisphenol B, bisphenol F, bisphenol S, diglycidyl ether of bisphenol compounds such as bisphenol AD. These may be used alone or in combination of two or more. Among them, since the obtained phenoxy resin is excellent in heat resistance and has a lower dielectric constant and dielectric loss tangent, diglycidyl ether of bisphenol A, or 3,3 ′, 5,5′-tetramethyl-4, Diglycidyl ether of 4′-biphenol is preferable, and diglycidyl ether of bisphenol A is preferable because the viscosity when varnished is low. When using these, it is preferable that the quantity is the range of 5-50 mass parts in a total of 100 mass parts of the said bifunctional epoxy compound (B) and another bifunctional epoxy compound (B ').

  Examples of the bifunctional phenol compound (A) used as a raw material for the phenoxy resin (X2) include 2,2′-biphenol, 2,3′-biphenol, 2,4′-biphenol, 3,3′-biphenol, 3 , 4′-biphenol, 4,4′-biphenol, 2-methyl-4,4′-biphenol, 3-methyl-4,4′-biphenol, 2,2′-dimethyl-4,4′-biphenol, 3, , 3′-dimethyl-4,4′-biphenol, 3,3 ′, 5,5′-tetramethyl-4,4′-biphenol, 2,2 ′, 3,3 ′, 5,5′-hexamethyl- Biphenol compounds such as 4,4′-biphenol, 2,2 ′, 3,3 ′, 5,5 ′, 6,6′-octamethyl-4,4′-biphenol, 4,4′-dihydroxydiphenyl ether, 4 , 4 -Dihydroxydiphenyl sulfide, hydroquinone, resorcin, catechol, 1,6'-dihydroxynaphthalene, 2,7'-dihydroxynaphthalene, 2,6'-dihydroxynaphthalene, 1,4'-dihydroxynaphthalene, bisphenol A, bisphenol B, bisphenol Bisphenol compounds such as F, bisphenol S, bisphenol AD and the like can be mentioned. These may be used alone or in combination of two or more. Among them, since the obtained phenoxy resin is excellent in heat resistance and has a lower dielectric constant and dielectric loss tangent, bisphenol A or 3,3 ′, 5,5′-tetramethyl-4,4′-biphenol is used. preferable.

  The phenoxy resin (X2) contains the bifunctional epoxy compound (B) as an essential component, and the bifunctional epoxy compound (b) containing the other bifunctional epoxy compound (B ′) as necessary, and the 2 It is obtained by reacting with the functional phenol compound (a) in the same manner as the phenoxy resin (X1).

  The epoxy equivalent of the phenoxy resin (X2), like the phenoxy resin (X1), is excellent in heat resistance when formed into a film and has a lower dielectric constant and dielectric loss tangent. The range is preferably 40,000 g / equivalent, and more preferably in the range of 9,000 to 35,000 g / equivalent.

  The phenoxy resin of the present invention may be used alone, for example, by applying a solution obtained by dissolving the phenoxy resin in an organic solvent to a base material and drying the solvent, the heat resistance is high, and the low dielectric conductivity. And a film excellent in low dielectric loss tangent property can be obtained. Moreover, by adding the phenoxy resin of the present invention to an epoxy resin composition containing an epoxy resin and an epoxy resin curing agent, the toughness of the cured product is improved and the film-forming property when used as a film is improved. I can do it. Such a curable resin composition of the present invention uses build-up films, prepregs, and circuit board applications by taking advantage of its high film-formability in addition to the characteristics of excellent heat resistance, low dielectric conductivity, and low dielectric loss tangent. Can be suitably used.

  Examples of the epoxy resin used in the curable resin composition of the present invention include bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenyl type epoxy resin, tetramethylbiphenyl type epoxy resin, polyhydroxynaphthalene type epoxy resin, and phenol novolac type. Epoxy resin, cresol novolak type epoxy resin, triphenylmethane type epoxy resin, tetraphenylethane type epoxy resin, dicyclopentadiene-phenol addition reaction type epoxy resin, phenol aralkyl type epoxy resin, naphthol novolak type epoxy resin, naphthol aralkyl type epoxy Resin, naphthol-phenol co-condensed novolak epoxy resin, naphthol-cresol co-condensed novolac epoxy resin, aromatic hydrocarbon formaldehyde tree Modified phenol resin type epoxy resin, biphenyl-modified novolak type epoxy resins. These may be used alone or in combination of two or more.

  Among the epoxy resins, various novolac epoxy resins are preferable in that a cured product having excellent heat resistance can be obtained. Moreover, in the point which the fluidity | liquidity of the resin composition obtained improves and it becomes easy to apply, and the point which the flexibility of a resin composition improves, bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenyl type It is preferable to use a bifunctional epoxy resin such as an epoxy resin or a tetramethylbiphenyl type epoxy resin. Regarding the flexibility of the resin composition, specifically, when a film is formed using a curable resin composition, a resin composition once dissolved in an organic solvent is applied onto a film substrate, and the solvent is added. There is a method of preparing an A-staged film by drying, but the flexibility of the A-staged film is improved, and cracks and cracks due to winding are less likely to occur. In this invention, since it is excellent in both the fluidity | liquidity and flexibility of a resin composition, and the heat resistance of hardened | cured material, it is preferable to use the said bifunctional epoxy resin and the said novolak-type epoxy resin together.

On the other hand, the curing agent for epoxy resin used here is, for example, amine compounds such as diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, imidazole, BF ₃ -amine complex, guanidine derivatives: dicyandiamide, linolene Amide compounds such as polyamide resin synthesized from acid dimer and ethylenediamine: phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methyl anhydride Acid anhydrides such as nadic acid, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride: phenol novolac resin, cresol novolac resin, aromatic hydrocarbon formaldehyde resin modified phenol resin Dicyclopentadiene phenol addition resin, phenol aralkyl resin, naphthol aralkyl resin, trimethylol methane resin, tetraphenylol ethane resin, naphthol novolac resin, naphthol-phenol co-condensed novolac resin, naphthol-cresol co-condensed novolac resin, biphenyl-modified phenol Resin (polyhydric phenol compound with phenolic nucleus linked by bismethylene group), biphenyl modified naphthol resin (polyvalent naphthol compound with phenolic nucleus linked by bismethylene group), aminotriazine modified phenolic resin (phenolic nucleus with melamine, benzoguanamine, etc.) And polyphenol compounds such as polyphenol compounds linked to each other).

  Among these, those containing a large amount of an aromatic skeleton in the molecular structure are preferable because they have excellent dielectric properties and moisture absorption resistance. Specifically, phenol novolac resins, cresol novolak resins, aromatic hydrocarbon formaldehyde resin-modified phenol resins Phenol aralkyl resin, naphthol aralkyl resin, naphthol novolak resin, naphthol-phenol co-condensed novolak resin, naphthol-cresol co-condensed novolak resin, biphenyl-modified phenol resin, biphenyl-modified naphthol resin, and aminotriazine-modified phenol resin are preferable.

  The curable resin composition of the present invention is excellent in film forming properties, and the cured product is excellent in heat resistance, low dielectric conductivity, and low dielectric loss tangent. Therefore, the phenoxy resin of the present invention is 10-50. It is preferable to contain in the range of 20 mass%, and it is more preferable to contain in the range of 20-40 mass%.

  Moreover, in the curable resin composition of this invention, the compounding ratio of the said epoxy resin and the said hardening | curing agent for epoxy resins is in the said hardening agent for epoxy resins with respect to a total of 1 equivalent of the epoxy group in an epoxy resin. It is preferable that it is a ratio from which the sum total of the active group will be 0.8-1.2 equivalent.

  The curable resin composition of the present invention may contain a curing accelerator as necessary. Examples of the curing accelerator used here include phosphorus compounds, tertiary amines, imidazoles, organic acid metal salts, Lewis acids, amine complex salts, and the like. In particular, when the epoxy resin composition of the present invention is used as a build-up material application or a circuit board application, dimethylaminopyridine and imidazole are preferable because of excellent heat resistance, dielectric characteristics, solder resistance, and the like.

  Further, the curable resin composition of the present invention may be dissolved in an organic solvent and used as a varnish. As described above, since the phenoxy resin of the present invention has a low viscosity when dissolved in an organic solvent and can be easily handled, it can be suitably used for such applications. The organic solvent used and the amount used vary depending on the application, but for example, aromatic hydrocarbon solvents such as toluene and xylene, ketone solvents such as acetone, methyl ethyl ketone and cyclohexanone, ethyl acetate, butyl acetate, cellosolve acetate, propylene Acetic acid ester solvents such as glycol monomethyl ether acetate and carbitol acetate, alcohol solvents such as ethanol, propanol and butanol, carbitol solvents such as cellosolve and butyl carbitol, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc. It is preferable to use it in a proportion that the nonvolatile content is 20 to 60% by mass.

  Moreover, the epoxy resin composition of this invention may use together other thermosetting resin suitably as needed. Examples of other thermosetting resins that can be used here include cyanate ester compounds, vinyl benzyl compounds, acrylic compounds, maleimide compounds, and copolymers of styrene and maleic anhydride. When other thermosetting resins described above are used in combination, the amount used is not particularly limited as long as the effect of the present invention is not impaired, but is in the range of 1 to 50 parts by weight in 100 parts by weight of the epoxy resin composition. It is preferable.

  When the curable resin composition of the present invention is used for applications requiring higher flame retardancy than for printed wiring board applications, a non-halogen flame retardant containing substantially no halogen atom may be blended.

  Examples of the non-halogen flame retardant include a phosphorus flame retardant, a nitrogen flame retardant, a silicone flame retardant, an inorganic flame retardant, an organic metal salt flame retardant, and the like. It is not intended to be used alone, and a plurality of the same type of flame retardants may be used, or different types of flame retardants may be used in combination.

  As the phosphorus flame retardant, either inorganic or organic can be used. Examples of the inorganic compounds include red phosphorus, monoammonium phosphate, diammonium phosphate, triammonium phosphate, ammonium phosphates such as ammonium polyphosphate, and inorganic nitrogen-containing phosphorus compounds such as phosphate amide. .

  The red phosphorus is preferably subjected to a surface treatment for the purpose of preventing hydrolysis and the like. Examples of the surface treatment method include (i) magnesium hydroxide, aluminum hydroxide, zinc hydroxide, water A method of coating with an inorganic compound such as titanium oxide, bismuth oxide, bismuth hydroxide, bismuth nitrate or a mixture thereof; (ii) an inorganic compound such as magnesium hydroxide, aluminum hydroxide, zinc hydroxide, titanium hydroxide; and A method of coating with a mixture of a thermosetting resin such as a phenol resin, (iii) thermosetting of a phenol resin or the like on a coating of an inorganic compound such as magnesium hydroxide, aluminum hydroxide, zinc hydroxide, or titanium hydroxide For example, a method of double coating with a resin may be used.

  The organic phosphorus compounds include, for example, general-purpose organic phosphorus compounds such as phosphate ester compounds, phosphonic acid compounds, phosphinic acid compounds, phosphine oxide compounds, phosphorane compounds, organic nitrogen-containing phosphorus compounds, and 9,10-dihydro -9-oxa-10-phosphaphenanthrene-10-oxide, 10- (2,5-dihydroxyphenyl) -10H-9-oxa-10-phosphaphenanthrene-10-oxide, 10- (2,7- Examples thereof include cyclic organic phosphorus compounds such as dihydrooxynaphthyl) -10H-9-oxa-10-phosphaphenanthrene-10-oxide and derivatives obtained by reacting them with compounds such as epoxy resins and phenol resins.

  The amount of these phosphorus-based flame retardants is preferably, for example, in the range of 0.1 to 2.0 parts by weight in the case of using red phosphorus in 100 parts by weight of the curable resin composition. Is preferably used in the range of 0.1 to 10.0 parts by mass, and more preferably in the range of 0.5 to 6.0 parts by mass.

  In addition, when using the phosphorous flame retardant, the phosphorous flame retardant may be used in combination with hydrotalcite, magnesium hydroxide, boric compound, zirconium oxide, black dye, calcium carbonate, zeolite, zinc molybdate, activated carbon, etc. Good.

  Examples of the nitrogen-based flame retardant include triazine compounds, cyanuric acid compounds, isocyanuric acid compounds, phenothiazines, and the like, and triazine compounds, cyanuric acid compounds, and isocyanuric acid compounds are preferable.

  Examples of the triazine compound include melamine, acetoguanamine, benzoguanamine, melon, melam, succinoguanamine, ethylene dimelamine, melamine polyphosphate, triguanamine, and the like, for example, sulfuric acid such as guanylmelamine sulfate, melem sulfate, and melam sulfate. Examples thereof include aminotriazine compounds, aminotriazine-modified phenol resins, and aminotriazine-modified phenol resins that are further modified with tung oil, isomerized linseed oil, and the like.

  Examples of the cyanuric acid compound include cyanuric acid and cyanuric acid melamine.

  The blending amount of the nitrogen-based flame retardant is preferably blended in a range of 0.05 to 10 parts by weight, for example, in a range of 0.1 to 5 parts by weight in 100 parts by weight of the curable resin composition. It is more preferable.

  Moreover, when using the said nitrogen-type flame retardant, you may use together a metal hydroxide, a molybdenum compound, etc.

  The silicone flame retardant is not particularly limited as long as it is an organic compound containing a silicon atom, and examples thereof include silicone oil, silicone rubber, and silicone resin.

  It is preferable to mix | blend the compounding quantity of the said silicone type flame retardant in the range of 0.05-20 mass parts in 100 mass parts of curable resin compositions, for example. Moreover, when using the said silicone type flame retardant, you may use a molybdenum compound, an alumina, etc. together.

  Examples of the inorganic flame retardant include metal hydroxide, metal oxide, metal carbonate compound, metal powder, boron compound, and low melting point glass.

  Examples of the metal hydroxide include aluminum hydroxide, magnesium hydroxide, dolomite, hydrotalcite, calcium hydroxide, barium hydroxide, and zirconium hydroxide.

  Examples of the metal oxide include zinc molybdate, molybdenum trioxide, zinc stannate, tin oxide, aluminum oxide, iron oxide, titanium oxide, manganese oxide, zirconium oxide, zinc oxide, molybdenum oxide, cobalt oxide, bismuth oxide, Examples thereof include chromium oxide, nickel oxide, copper oxide, and tungsten oxide.

  Examples of the metal carbonate compound include zinc carbonate, magnesium carbonate, calcium carbonate, barium carbonate, basic magnesium carbonate, aluminum carbonate, iron carbonate, cobalt carbonate, and titanium carbonate.

  Examples of the metal powder include aluminum, iron, titanium, manganese, zinc, molybdenum, cobalt, bismuth, chromium, nickel, copper, tungsten, and tin.

  Examples of the boron compound include zinc borate, zinc metaborate, barium metaborate, boric acid, and borax.

Examples of the low-melting-point glass include Sheepley (Bokusui Brown), hydrated glass SiO ₂ —MgO—H ₂ O, PbO—B ₂ O ₃ system, ZnO—P ₂ O ₅ —MgO system, and P ₂ O. Glass forms such as _5- B ₂ O ₃ —PbO—MgO, P—Sn—O—F, PbO—V ₂ O ₅ —TeO ₂ , Al ₂ O ₃ —H ₂ O, lead borosilicate, etc. A compound can be mentioned.

  The blending amount of the inorganic flame retardant is preferably blended in the range of 0.05 to 20 parts by weight, for example, in the range of 0.5 to 15 parts by weight in 100 parts by weight of the curable resin composition. It is more preferable.

  Examples of the organic metal salt flame retardant include ferrocene, acetylacetonate metal complex, organic metal carbonyl compound, organic cobalt salt compound, organic sulfonic acid metal salt, metal atom and aromatic compound or heterocyclic compound. And the like.

  It is preferable to mix | blend the compounding quantity of the said organometallic salt type flame retardant in the range of 0.005-10 mass parts in 100 mass parts of curable resin compositions, for example.

  The curable resin composition of this invention can mix | blend an inorganic filler as needed. Examples of the inorganic filler include fused silica, crystalline silica, alumina, silicon nitride, and aluminum hydroxide. When particularly increasing the blending amount of the inorganic filler, it is preferable to use fused silica. The fused silica can be used in either a crushed shape or a spherical shape. However, in order to increase the blending amount of the fused silica and suppress an increase in the melt viscosity of the molding material, it is preferable to mainly use a spherical shape. In order to further increase the blending amount of the spherical silica, it is preferable to appropriately adjust the particle size distribution of the spherical silica. The filling rate is preferably higher in consideration of flame retardancy, and particularly preferably 20% by mass or more with respect to the total amount of the curable resin composition. Moreover, when using for uses, such as an electrically conductive paste, electroconductive fillers, such as silver powder and copper powder, can be used.

  In addition to the above, the curable resin composition of the present invention may contain various compounding agents such as a silane coupling agent, a release agent, a pigment, and an emulsifier, if necessary.

  The curable resin composition of the present invention can be obtained by uniformly mixing the above-described components, and can be easily made into a cured product by a method similar to the curing of conventionally known epoxy resin compositions. Examples of the cured product include molded cured products such as laminates, cast products, adhesive layers, coating films, and films.

  Since the curable resin composition of the present invention has a low dielectric constant and dielectric loss tangent of the cured product, circuits such as a hard printed wiring board material, a resin composition for a flexible wiring board, and an interlayer insulating material for a build-up board It can be suitably used for various electronic materials such as insulating materials for substrates, semiconductor sealing materials, conductive pastes, build-up adhesive films, resin casting materials, and adhesives. Among them, since the phenoxy resin of the present invention has a low viscosity when dissolved in an organic solvent and is easy to handle, it is necessary to use a varnish, that is, a hard printed wiring board material, a resin composition for a flexible wiring board, a build-up board. It can be particularly preferably used as a circuit board material such as an interlayer insulating material.

  Of these, when applied to circuit board applications, a varnish obtained by diluting the curable resin composition of the present invention in an organic solvent is obtained, and this is shaped into a plate shape and laminated with copper foil, followed by heat-pressure molding Can be manufactured. Moreover, when applying to a hard printed circuit board use, a prepreg is obtained by impregnating a reinforcing base material with a varnish-like curable resin composition containing an organic solvent, and semi-curing, and a copper foil is laminated thereon. It can be manufactured by a method of thermocompression bonding. Examples of the reinforcing substrate that can be used here include paper, glass cloth, glass nonwoven fabric, aramid paper, aramid cloth, glass mat, and glass roving cloth. More specifically, the varnish-like epoxy resin composition described above is first heated at a heating temperature corresponding to the solvent type used, preferably 50 to 170 ° C. to obtain a prepreg that is a cured product. . At this time, the mass ratio of the curable resin composition to be used and the reinforcing substrate is not particularly limited, but it is usually preferable that the resin content in the prepreg is 20 to 60 mass%. Next, the prepreg obtained as described above is laminated by a conventional method, and a copper foil is appropriately stacked, and then subjected to thermocompression bonding at a pressure of 1 to 10 MPa at 170 to 250 ° C. for 10 minutes to 3 hours, A target circuit board can be obtained.

  In order to produce a flexible wiring board from the curable resin composition of the present invention, a curable resin composition containing an organic solvent is applied to an electrical insulating film using a coating machine such as a reverse roll coater or a comma coater. Subsequently, it heats for 1 to 15 minutes at 60-170 degreeC using a heater, volatilizes a solvent, and makes curable resin composition B-stage. Next, the metal foil is thermocompression bonded to the resin composition layer using a heating roll or the like. At that time, the pressure is preferably 2 to 200 N / cm and the pressure is preferably 40 to 200 ° C. If sufficient adhesive performance can be obtained, the process may be completed here. However, when complete curing is required, it is preferably post-cured at 100 to 200 ° C. for 1 to 24 hours. The thickness of the resin composition layer after finally curing is preferably in the range of 5 to 100 μm.

  In order to produce an interlayer insulating material for a build-up substrate from the curable resin composition of the present invention, for example, a curable resin composition appropriately blended with rubber, filler, etc., is applied to a wiring board on which a circuit is formed by a spray coating method, After applying using a curtain coating method or the like, it is cured. Then, after drilling a predetermined through-hole part etc. as needed, it treats with a roughening agent, forms the unevenness | corrugation by washing the surface with hot water, and metal-treats, such as copper. As the plating method, electroless plating or electrolytic plating treatment is preferable, and examples of the roughening agent include an oxidizing agent, an alkali, and an organic solvent. Such operations are sequentially repeated as desired, and a build-up base can be obtained by alternately building up and forming the resin insulating layer and the conductor layer having a predetermined circuit pattern. However, the through-hole portion is formed after the outermost resin insulating layer is formed. Moreover, a roughened surface is formed by heat-pressing a copper foil with a resin obtained by semi-curing a curable resin composition on a copper foil onto a wiring board on which a circuit is formed at 170 to 250 ° C. It is also possible to produce a build-up substrate by omitting this process.

  The method for producing an adhesive film for build-up from the curable resin composition of the present invention is, for example, applied to a support film by applying the curable resin composition of the present invention on a support film to form a resin composition layer. The method of making it an adhesive film is mentioned.

  When the curable resin composition of the present invention is used for a build-up adhesive film, the adhesive film is softened under the temperature condition of the laminate in the vacuum laminating method (usually 70 ° C. to 140 ° C.), and simultaneously with the lamination of the circuit board, It is important to show fluidity (resin flow) that allows resin filling in via holes or through holes present in a circuit board, and it is preferable to blend the above-described components so as to exhibit such characteristics.

  Here, the diameter of the through hole of the multilayer printed wiring board is usually 0.1 to 0.5 mm, and the depth is usually 0.1 to 1.2 mm. It is usually preferable to allow resin filling in this range. When laminating both surfaces of the circuit board, it is desirable to fill about 1/2 of the through hole.

  Specifically, the method for producing the adhesive film described above is, after preparing the varnish-like epoxy resin composition of the present invention, coating the varnish-like composition on the surface of the support film and further heating, or It can be produced by drying the organic solvent by hot air blowing or the like to form the layer (α) of the curable resin composition.

  The thickness of the formed layer (α) is usually not less than the thickness of the conductor layer. Since the thickness of the conductor layer of the circuit board is usually in the range of 5 to 70 μm, the thickness of the resin composition layer is preferably 10 to 100 μm.

  In addition, the said layer ((alpha)) may be protected with the protective film mentioned later. By protecting with a protective film, it is possible to prevent dust and the like from being attached to the surface of the resin composition layer and scratches.

  The above-mentioned support film and protective film are made of polyolefin such as polyethylene, polypropylene and polyvinyl chloride, polyethylene terephthalate (hereinafter sometimes abbreviated as “PET”), polyester such as polyethylene naphthalate, polycarbonate, polyimide, and further. Examples thereof include metal foil such as pattern paper, copper foil, and aluminum foil. In addition, the support film and the protective film may be subjected to a release treatment in addition to the mud treatment and the corona treatment.

  Although the thickness of a support film is not specifically limited, Usually, it is 10-150 micrometers, Preferably it is used in 25-50 micrometers. Moreover, it is preferable that the thickness of a protective film shall be 1-40 micrometers.

  The above support film is peeled off after being laminated on a circuit board or after forming an insulating layer by heat curing. If the support film is peeled after the adhesive film is heat-cured, adhesion of dust and the like in the curing process can be prevented. In the case of peeling after curing, the support film is usually subjected to a release treatment in advance.

  Next, the method for producing a multilayer printed wiring board using the adhesive film obtained as described above is, for example, when the layer (α) is protected with a protective film, Lamination is performed on one or both sides of the circuit board by, for example, vacuum laminating so that α) is in direct contact with the circuit board. The laminating method may be a batch method or a continuous method using a roll. Further, the adhesive film and the circuit board may be heated (preheated) as necessary before lamination.

The laminating conditions are preferably a pressure bonding temperature (laminating temperature) of 70 to 140 ° C., a pressure bonding pressure of preferably 1 to 11 kgf / cm ² (9.8 × 10 ^{4 to} 107.9 × 10 ⁴ N / m 2), Lamination is preferably performed under reduced pressure with an air pressure of 20 mmHg (26.7 hPa) or less.

  When the curable resin composition of the present invention is used as a conductive paste, for example, a method of dispersing fine conductive particles in a curable resin composition to form a composition for an anisotropic conductive film, which is liquid at room temperature. Examples thereof include a paste resin composition for circuit connection and an anisotropic conductive adhesive.

  The curable resin composition of the present invention can also be used as a resist ink. In this case, a vinyl monomer having an ethylenically unsaturated double bond and a cationic polymerization catalyst as a curing agent are blended in the curable resin composition, and further, a pigment, talc, and filler are added to form a resist ink composition. Then, after apply | coating on a printed circuit board by a screen printing system, the method of setting it as a resist ink hardened | cured material is mentioned.

  As described above, the phenoxy resin of the present invention has a low viscosity when varnished compared to a conventional phenoxy resin, a cured product having high heat resistance, and a low dielectric constant and dielectric loss tangent. Have Therefore, the phenoxy resin of the present invention can be easily varnished even when mixed in an epoxy resin composition, thereby not only improving the film forming property of the resin composition, but also having high heat resistance, and A cured product having a low dielectric constant and dielectric loss tangent can be obtained. Such a resin composition can be suitably used for an electronic material application, and can contribute to realization of high-speed operation of a high-frequency device.

  Next, the present invention will be specifically described with reference to Examples and Comparative Examples. In the following, “parts” and “%” are based on mass unless otherwise specified. GPC was measured under the following conditions.

Measuring device: “HLC-8220 GPC” manufactured by Tosoh Corporation
Column: Guard column “HXL-L” manufactured by Tosoh Corporation
+ "TSK-GEL G2000HXL" manufactured by Tosoh Corporation
+ "TSK-GEL G2000HXL" manufactured by Tosoh Corporation
+ Tosoh Corporation “TSK-GEL G3000HXL”
+ Tosoh Corporation “TSK-GEL G4000HXL”
Detector: RI (Differential refraction diameter)
Data processing: “GPC-8020 Model II version 4.10” manufactured by Tosoh Corporation
Measurement conditions: Column temperature 40 ° C
Developing solvent Tetrahydrofuran
Flow rate: 1.0 ml / min Standard: The following monodisperse polystyrene having a known molecular weight was used in accordance with the measurement manual of “GPC-8020 Model II version 4.10”.

(Polystyrene used)
“A-500” manufactured by Tosoh Corporation
"A-1000" manufactured by Tosoh Corporation
"A-2500" manufactured by Tosoh Corporation
"A-5000" manufactured by Tosoh Corporation
“F-1” manufactured by Tosoh Corporation
"F-2" manufactured by Tosoh Corporation
“F-4” manufactured by Tosoh Corporation
“F-10” manufactured by Tosoh Corporation
“F-20” manufactured by Tosoh Corporation
“F-40” manufactured by Tosoh Corporation
“F-80” manufactured by Tosoh Corporation
“F-128” manufactured by Tosoh Corporation
Sample: A 1.0 mass% tetrahydrofuran solution filtered in terms of resin solids and filtered through a microfilter (50 μl).

Production Example 1 Production of Biphenol Compound (A) 300.0 g of 3,3 ′, 5,5′-tetramethyl-4,4′-biphenol was added to a flask equipped with a thermometer, a condenser tube, a fractionating tube, and a stirrer. (1.24 mol) and 253.1 g (2.34 mol) of benzyl alcohol were charged, the inside of the system was purged with nitrogen, the nitrogen was slowly flowed, the temperature was raised to 120 ° C. with stirring, and the mixture was stirred for 15 minutes. . Next, 5.53 g of paratoluenesulfonic acid was charged, and the temperature was raised to 150 ° C. while distilling off the generated water out of the system, followed by stirring for 5 hours. Next, the mixture was cooled to 120 ° C., 2.4 g of a 49% aqueous sodium hydroxide solution was added, the mixture was cooled to 80 ° C. with stirring, 1022 g of methyl isobutyl ketone and 255 g of water were added, and the mixture was stirred at 80 ° C. for 5 minutes. And the aqueous layer was separated. After confirming that the aqueous layer was almost neutral, 255 g of water was further added, followed by liquid separation in the same manner. Thereafter, water was removed by decanter dehydration, and then MIBK was removed under reduced pressure to obtain 449 g of a brown solid biphenol compound (A). The obtained biphenol compound (A) had a hydroxyl group equivalent of 210 g / equivalent. A GPC chart of the biphenol compound (A) is shown in FIG.

Production Example 2 Production of Bifunctional Epoxy Compound (B) 200.0 g (0.47 mol) of the biphenol compound (A) obtained in Production Example 1 was placed in a flask equipped with a thermometer, a condenser tube, a fractionating tube, and a stirrer. , Epichlorohydrin 105.2 g (3.76 mol) and butanol 60.0 g were charged, the inside of the system was purged with nitrogen, nitrogen was slowly flowed, and 18.8 g (0.094 mol) of 20% NaOH aqueous solution was charged. After raising the temperature to 0 ° C., the mixture was stirred for 2 hours. Then, it heated up to 60 degreeC and stirred for 30 minutes. Next, 188.0 g (0.94 mol) of a 20% NaOH aqueous solution was charged with stirring at 60 ° C. over 30 minutes, and then stirred for 90 minutes. Next, 57.4 g of water was added, and the mixture was stirred at 60 ° C. for 5 minutes and then allowed to stand for 10 minutes to separate the aqueous layer. Then, excess epichlorohydrin was distilled off under reduced pressure, and 430.1 g of MIBK and 10.3 g of 5% NaOH aqueous solution were charged at 80 ° C. while stirring for 1 hour. Subsequently, 126.5g of 1% NaOH aqueous solution was prepared, and it stirred at 80 degreeC for 1 hour, Then, it left still for 10 minutes, and the water layer was liquid-separated. Next, the oil layer was washed 3 times with 126.5 g of water. Water was removed by decanter dehydration, and filtered while hot at 120 ° C., and the solvent was distilled off under reduced pressure to obtain 205.3 g of a brown solid bifunctional epoxy compound (B). The epoxy equivalent of the obtained bifunctional epoxy compound (B) was 282 g / equivalent. A GPC chart of the bifunctional epoxy compound (B) is shown in FIG.

Example 1 Production of Phenoxy Resin (1) 52.2 g of the biphenol compound (A) obtained in Production Example 1 and a bisphenol A type epoxy resin (manufactured by DIC Corporation) were placed in a flask equipped with a thermometer, a condenser tube and a stirrer. “EPCLON-850S”: epoxy equivalent 188 g / equivalent) 47.8 g and cyclohexanone 42.8 g were charged, the inside of the system was purged with nitrogen, nitrogen was slowly flowed, and the temperature was raised to 80 ° C. with stirring. Next, 40 mg of 2-ethyl-4-methylimidazole was added, and the temperature was further increased to 150 ° C. The mixture was reacted at 150 ° C. for 20 hours to obtain a phenoxy resin (1) solution. The epoxy equivalent of the resin solid content of the obtained phenoxy resin (1) was 12,100 g / equivalent. A GPC chart of the phenoxy resin (1) is shown in FIG.

Example 2 Production of Phenoxy Resin (2) 52.1 g of the biphenol compound (A) obtained in Production Example 1 and a bisphenol A type epoxy resin (manufactured by DIC Corporation) were placed in a flask equipped with a thermometer, a condenser tube and a stirrer. “EPCLON-850S”: epoxy equivalent 188 g / equivalent) 47.9 g and cyclohexanone 42.8 g were charged, the inside of the system was purged with nitrogen, nitrogen was slowly flowed, and the temperature was raised to 80 ° C. with stirring. Next, 40 mg of 2-ethyl-4-methylimidazole was added, and the temperature was further increased to 150 ° C. The mixture was reacted at 150 ° C. for 20 hours to obtain a phenoxy resin (2) solution. The epoxy equivalent of the resin solid content of the obtained phenoxy resin (2) was 25,200 g / equivalent. A GPC chart of the phenoxy resin (2) is shown in FIG.

Example 3 Production of Phenoxy Resin (3) In a flask equipped with a thermometer, a condenser tube, and a stirrer, 42.0 g of the biphenol compound (A) obtained in Production Example 1 and the bifunctional epoxy compound obtained in Production Example 2 ( B) 58.0 g and cyclohexanone 42.8 g were charged, the inside of the system was purged with nitrogen, nitrogen was slowly flowed, and the temperature was raised to 80 ° C. with stirring. Next, 40 mg of 2-ethyl-4-methylimidazole was added, and the temperature was further increased to 150 ° C. The mixture was reacted at 150 ° C. for 20 hours to obtain a phenoxy resin (3) solution. The epoxy equivalent of the resin solid content of the obtained phenoxy resin (3) was 12,500 g / equivalent. A GPC chart of the phenoxy resin (3) is shown in FIG.

Example 4 Production of Phenoxy Resin (4) In a flask equipped with a thermometer, a condenser tube, and a stirrer, 42.3 g of the biphenol compound (A) obtained in Production Example 1 and the bifunctional epoxy compound obtained in Production Example 2 ( B) 57.7 g and cyclohexanone 42.8 g were charged, the inside of the system was purged with nitrogen, nitrogen was slowly flowed, and the temperature was raised to 80 ° C. with stirring. Next, 40 mg of 2-ethyl-4-methylimidazole was added, and the temperature was further increased to 150 ° C. The mixture was reacted at 150 ° C. for 20 hours to obtain a phenoxy resin (4) solution. The epoxy equivalent of the resin solid content of the obtained phenoxy resin (4) was 25,400 g / equivalent. A GPC chart of the phenoxy resin (4) is shown in FIG.

Example 5 Production of Phenoxy Resin (5) In a flask equipped with a thermometer, a condenser tube, and a stirrer, 42.7 g of the biphenol compound (A) obtained in Production Example 1 and the bifunctional epoxy compound obtained in Production Example 2 ( B) 57.3 g and 42.8 g of cyclohexanone were charged, the inside of the system was purged with nitrogen, nitrogen was slowly flowed, and the temperature was raised to 80 ° C. with stirring. Next, 40 mg of 2-ethyl-4-methylimidazole was added, and the temperature was further increased to 150 ° C. The mixture was reacted at 150 ° C. for 20 hours to obtain a phenoxy resin (5) solution. The epoxy equivalent of the resin solid content of the obtained phenoxy resin (5) was 35,100 g / equivalent. A GPC chart of the phenoxy resin (5) is shown in FIG.

Comparative Example 1 Production of Phenoxy Resin (1 ′) Bisphenol A 63.2 g, bisphenol A type epoxy resin (“EPCLON-850S” manufactured by DIC Corporation): Epoxy equivalent 188 g / Equivalent) 36.8 g and cyclohexanone 42.8 g were charged, the inside of the system was purged with nitrogen, nitrogen was slowly flowed, and the temperature was raised to 80 ° C. with stirring. Next, 40 mg of 2-ethyl-4-methylimidazole was added, and the temperature was further increased to 150 ° C. The mixture was reacted at 150 ° C. for 20 hours to obtain a phenoxy resin (1 ′) solution. The epoxy equivalent of the resin solid content of the obtained phenoxy resin (1 ′) was 12,700 g / equivalent.

Comparative Example 2 Production of Phenoxy Resin (2 ′) 3,3 ′, 5,5′-Tetramethyl-4,4′-biphenol 40.0 g, bisphenol A type in a flask equipped with a thermometer, condenser and stirrer Epoxy resin (DIC Corporation "EPCLON-850S": Epoxy equivalent 188 g / equivalent) 60.0 g, cyclohexanone 42.8 g were charged, the inside of the system was purged with nitrogen, and nitrogen was slowly flowed to 80 ° C with stirring. The temperature was raised. Next, 40 mg of 2-ethyl-4-methylimidazole was added, and the temperature was further increased to 150 ° C. The mixture was reacted at 150 ° C. for 20 hours to obtain a phenoxy resin (2 ′) solution. The epoxy equivalent of the resin solid content of the obtained phenoxy resin (2 ′) was 11,700 g / equivalent.

Evaluation of Phenoxy Resin The following various evaluation tests were performed on the phenoxy resin obtained in Examples 1 to 5 or Comparative Examples 1 and 2. The results are shown in Table 1 or Table 2.

<Measurement of varnish viscosity>
A mixed solvent (mass ratio 1: 1) of cyclohexanone and methyl ethyl ketone was added to each of the phenoxy resin solutions obtained in Examples 1 to 5 or Comparative Examples 1 and 2, and the nonvolatile content was adjusted to 30% by mass. Varnished. The viscosity of each phenoxy resin varnish obtained was measured by the Cannon Fenceke method at 25 ° C. (using “Canon Fenceke viscometer” manufactured by Kusano Kagaku Co., Ltd.).

<Creation of film>
The varnish obtained above was applied onto mirror surface aluminum with an applicator (“Film Applicator 60MILs” manufactured by TP Giken Co., Ltd.), respectively, with a dryer at 50 ° C. for 10 minutes, then at 100 ° C. for 10 minutes, at 150 ° C. It was made to dry in order of 1 hour, and the film was created. The obtained film was evaluated for heat resistance and dielectric properties by the following methods.

<Evaluation of heat resistance>
About the created film, using a viscoelasticity measuring device (DMA: solid viscoelasticity measuring device “RSAII” manufactured by Rheometric, rectangular tension method; frequency 1 Hz, heating rate 3 ° C./min) (The tan δ change rate is the highest) was evaluated as the glass transition temperature.

<Evaluation of dielectric properties>
In accordance with JIS-C-6481, five test pieces of film were stacked with an impedance material analyzer “HP4291B” manufactured by Agilent Technologies, and the dielectric constant and dielectric loss tangent at 1 GHz and 10 GHz were measured.

Examples 6 and 7 and Comparative Examples 3 and 4
<Adjustment of curable resin composition>
Cresol novolac type epoxy resin (DIC Corporation "EPICLON-N-680-75M": Epoxy equivalent 212g / equivalent) 55 parts by mass, liquid bisphenol A type epoxy resin (DIC Corporation "EPICLON-850S": Epoxy Equivalent 188 g / equivalent) 10 parts by mass, phenol novolac resin (DIC Corporation "PHENOLITE-TD-2090-60M": hydroxyl group equivalent 105 g / equivalent) 25 parts by mass, Examples 2, 5 or Comparative Example 1, 10 parts by mass of any of the phenoxy resin solutions obtained in 2 in the resin solid content, 0.1 parts by mass of 2-ethyl-4-methylimidazole as a curing accelerator, and 50 parts by mass of methyl ethyl ketone as a solvent are mixed with a high-speed mixer. A curable resin composition was prepared by uniformly dispersing.

<Creation and evaluation of film>
The curable resin assembly obtained above was applied on mirror surface aluminum with an applicator (“Film Applicator 60MILs” manufactured by TP Giken Co., Ltd.), 1 hour at 60 ° C. with a dryer, then 1 hour at 150 ° C. The film was dried at 200 ° C. for 1 hour in order. The obtained film was evaluated for heat resistance and dielectric properties by the same method as the evaluation of the phenoxy resin. The results are shown in Table 3.

Claims (13)

A phenoxy resin obtained by reacting a bifunctional phenol compound (a) and a bifunctional epoxy compound (b) as essential raw materials, wherein the bifunctional phenol compound (a) has the following structural formula (1)

(In the formula, each R ¹ is independently an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and R ² is independently a hydrogen atom or 1 carbon atom. Or an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and Ar is independently a phenylene group, a naphthylene group, or an alkyl group having 1 to 6 carbon atoms on the aromatic nucleus. Or any one of structural parts having 1 to a plurality of alkoxy groups having 1 to 6 carbon atoms, m is each independently 1 or 2, n is each independently an integer of 0 to 2, And at least one of two n is 1 or 2.)
The phenoxy resin characterized by using the biphenol compound (A) represented by these. The bifunctional epoxy compound (b) has the following structural formula (2)

(In the formula, each R ¹ is independently an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and R ² is independently a hydrogen atom or 1 carbon atom. Or an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and Ar is independently a phenylene group, a naphthylene group, or an alkyl group having 1 to 6 carbon atoms on the aromatic nucleus. Or any one of structural parts having one or more alkoxy groups having 1 to 6 carbon atoms, G represents a glycidyl group, m is each independently 1 or 2, and n is each independently 0 And an integer of ˜2, and at least one of the two n is 1 or 2.)
The phenoxy resin according to claim 1, which is a bifunctional epoxy compound (B) represented by the formula: The biphenol compound (A) comprises 3,3 ′, 5,5′-tetramethyl-4,4′-biphenol and an aralkylating agent, 3,3 ′, 5,5′-tetramethyl-4, 2. The phenoxy resin according to claim 1, which is obtained by reacting 1 mol of 4′-biphenol at a ratio of 1 to 4 mol of the aralkylating agent. A phenoxy resin obtained by reacting a bifunctional phenol compound (a) and a bifunctional epoxy compound (b) as essential raw materials, wherein the bifunctional epoxy compound (b) has the following structural formula (2)

(In the formula, each R ¹ is independently an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and R ² is independently a hydrogen atom or 1 carbon atom. Or an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and Ar is independently a phenylene group, a naphthylene group, or an alkyl group having 1 to 6 carbon atoms on the aromatic nucleus. Or any one of structural parts having one or more alkoxy groups having 1 to 6 carbon atoms, G represents a glycidyl group, m is each independently 1 or 2, and n is each independently 0 And an integer of ˜2, and at least one of the two n is 1 or 2.)
The phenoxy resin characterized by using the bifunctional epoxy compound (B) represented by these. The phenoxy resin according to claim 4, wherein the bifunctional phenol compound (a) is bisphenol A. The bifunctional epoxy compound (B) comprises 3,3 ′, 5,5′-tetramethyl-4,4′-biphenol and an aralkylating agent, and 3,3 ′, 5,5′-tetramethyl- The phenoxy resin according to claim 4, which is obtained by glycidyl etherification of a biphenol compound obtained by reacting 1 mol of 4,4'-biphenol at a ratio of 1 to 4 mol of the aralkylating agent. The phenoxy resin according to any one of claims 1 to 6, wherein an epoxy equivalent is in a range of 5,000 to 40,000 g / equivalent. A curable resin composition comprising the phenoxy resin according to any one of claims 1 to 7, an epoxy resin, and a curing agent for epoxy resin. The film which uses the phenoxy resin as described in any one of Claims 1-7 as a main component. A cured product obtained by curing the curable resin composition according to claim 8. A prepreg obtained by impregnating a reinforced resin composition obtained by diluting the curable resin composition according to claim 8 with an organic solvent into a reinforcing base material and semi-curing the resulting impregnated base material. A circuit board obtained by obtaining a varnish obtained by diluting the curable resin composition according to claim 8 in an organic solvent, and subjecting the varnish to a plate shape and copper foil. The buildup film obtained by apply | coating what dried the curable resin composition of Claim 8 in the organic solvent on a base film, and making it dry.

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