JP2025017250A - Modified phenoxy resin, resin composition, cured product, fiber-reinforced plastic, laminate, and method for producing modified phenoxy resin - Google Patents

Abstract

To provide: an unsaturated heterocycle-containing acyl group-modified phenoxy resin excellent in heat resistance, solvent solubility, and adhesiveness; a resin composition comprising the phenoxy resin and a curing agent; a cured product of the composition; a fiber-reinforced plastic and a laminate that are formed using the resin composition; and a method for producing the phenoxy resin.SOLUTION: The modified phenoxy resin is represented by the general formula (1) in the figure and has a weight-average molecular weight of 5,000 to 200,000. In the formula: X is a divalent group; Y is a hydrogen atom, a C5-20 unsaturated heterocycle-containing acyl group, or a glycidyl group; Z is a C5-20 unsaturated heterocycle-containing acyl group or a hydrogen atom, with the acyl groups constituting at least 5 mol%; and n represents the number of the repeating units.SELECTED DRAWING: Figure 1

Description

The present invention relates to a modified phenoxy resin that has excellent heat resistance, solvent solubility, and adhesiveness. It also relates to a resin composition containing the modified phenoxy resin and a curing agent, a cured product thereof, and a fiber-reinforced plastic and a laminate made using the resin composition. It also relates to a method for producing the modified phenoxy resin.

Epoxy resins are widely used in fields such as paints, civil engineering, adhesives, and electrical materials because of their excellent heat resistance, adhesive properties, chemical resistance, water resistance, mechanical strength, and electrical properties. They can also be made into film by increasing their molecular weight in various ways. Such highly molecular epoxy resins are called phenoxy resins. In particular, bisphenol A-type phenoxy resins are used mainly as base resins for paint varnishes and for film molding, and are added to epoxy resin varnishes to adjust the flowability and improve the toughness and adhesive properties of the cured product. In addition, those that have phosphorus or bromine atoms in the skeleton are used as flame retardants blended into epoxy resin compositions and thermoplastic resins.

In particular, phenoxy resin, which is the base material for fiber-reinforced plastics used in civil engineering, industrial equipment, aerospace, etc., is required to have heat resistance, solvent solubility, and adhesion to other materials.

In response to such demands, a method has been proposed to improve adhesion and flame retardancy by introducing sulfur atoms into the structure. Patent Document 1 discloses a phenoxy resin obtained by reacting a bisphenol compound having a sulfur atom in its structure with a difunctional epoxy resin. However, although this method can impart excellent adhesion to the phenoxy resin and its cured product, it does not improve solvent solubility.

JP 2017-115055 A

The object of the present invention is to provide a modified phenoxy resin having excellent heat resistance, solvent solubility, and adhesion, a resin composition containing the modified phenoxy resin and a curing agent, a cured product thereof having excellent heat resistance, and a fiber-reinforced plastic or laminate made of the resin composition.

In order to solve the above problems, the present inventors conducted extensive research into modified phenoxy resins and discovered that modified phenoxy resins having a specific structure have excellent heat resistance, solvent solubility, and adhesion, and further discovered that a cured product obtained by curing a resin composition containing the same has excellent heat resistance, thus completing the present invention.

ここで、Ｘは２価の基である。Ｙは独立に、水素原子、上記式（２ａ）～（２ｆ）で表される炭素数５～２０の不飽和複素環含有アシル基、又はグリシジル基である。Ｚは独立に、水素原子又は炭素数５～２０の不飽和複素環含有アシル基であり、５モル％以上は前記アシル基である。ｎは繰り返し数であり、その平均値は、１５以上５００以下である。 That is, the present invention relates to a modified phenoxy resin represented by the following formula (1) and having a weight average molecular weight of 5,000 to 200,000.

Here, X is a divalent group. Y is independently a hydrogen atom, an unsaturated heterocyclic ring-containing acyl group having 5 to 20 carbon atoms and represented by the above formulas (2a) to (2f), or a glycidyl group. Z is independently a hydrogen atom or an unsaturated heterocyclic ring-containing acyl group having 5 to 20 carbon atoms, and 5 mol % or more of the acyl group is the above acyl group. n is the number of repetitions, and the average value is 15 or more and 500 or less.

ここで、Ｒ^１～Ｒ^６は独立に、炭素数１～６の炭化水素基であり、ｎ１は０～３の整数であり、ｎ２は０～５の整数であり、ｎ３は０～５の整数であり、ｎ４は０～４の整数であり、ｎ５は０～６の整数であり、ｎ６は０～８の整数である。Ｗは酸素原子又は硫黄原子である。

The unsaturated heterocycle-containing acyl group having 5 to 20 carbon atoms preferably includes any one of the unsaturated heterocycle-containing acyl groups represented by the following formulae (2a) to (2f), and more preferably includes any one of the unsaturated heterocycle-containing acyl groups represented by the following formulae (3a) to (3c).

Here, R ¹ to R ⁶ are independently a hydrocarbon group having 1 to 6 carbon atoms, n1 is an integer from 0 to 3, n2 is an integer from 0 to 5, n3 is an integer from 0 to 5, n4 is an integer from 0 to 4, n5 is an integer from 0 to 6, and n6 is an integer from 0 to 8. W is an oxygen atom or a sulfur atom.

The present invention also relates to a resin composition containing a modified phenoxy resin and a curing agent.
It is preferable that the curing agent is contained in an amount of 0.1 to 100 parts by mass as solid content per 100 parts by mass of the solid content of the modified phenoxy resin.

The curing agent blended in the resin composition is preferably at least one selected from the group consisting of acrylic ester resins, melamine resins, urea resins, phenolic resins, acid anhydride compounds, amine compounds, imidazole compounds, amide compounds, cationic polymerization initiators, organic phosphines, phosphonium salts, tetraphenylboron salts, hydrazide compounds, boron halide amine complexes, polymercaptan compounds, isocyanate compounds, polyisocyanate compounds, blocked isocyanate compounds, and active ester compounds.

The present invention also relates to a resin composition comprising the above modified phenoxy resin, an epoxy resin and a curing agent, in which the mass ratio of the solid contents of the modified phenoxy resin and the epoxy resin is 99/1 to 1/99.
It is preferable that the curing agent is contained in an amount of 0.1 to 100 parts by mass as solid content per 100 parts by mass of the total of the solid contents of the modified phenoxy resin and the epoxy resin.

The same applies to the curing agent that is blended into the resin composition containing the above epoxy resin.

The present invention also relates to a cured product obtained by curing each of the above resin compositions, and to a fiber-reinforced plastic and a laminate plate obtained by using each of the above resin compositions.

ここで、Ｘ^１及びＸ^２は２価の基である。Ｇはグリシジル基である。Ｑは炭素数５～２０の不飽和複素環含有アシル基又は水素原子であり、５モル％以上は上記アシル基である。ｍは繰り返し数であり、その平均値は０以上６以下である。なお、一般式（５）で表される化合物は、Ｑの両方が上記アシル基である化合物、一方が上記アシル基である化合物、及び両方が水素原子である化合物から選ばれる２種以上の混合物であってもよい。 The present invention also relates to a method for producing the above-mentioned modified phenoxy resin, which is characterized by reacting a bifunctional epoxy resin represented by the following general formula (4) with a compound represented by the following general formula (5).

Here, ^X1 and ^X2 are divalent groups. G is a glycidyl group. Q is an unsaturated heterocycle-containing acyl group having 5 to 20 carbon atoms or a hydrogen atom, and 5 mol% or more of the acyl group is the above. m is the number of repetitions, the average value of which is 0 to 6. The compound represented by general formula (5) may be a mixture of two or more selected from a compound in which both Qs are the above acyl group, a compound in which one Q is the above acyl group, and a compound in which both Qs are hydrogen atoms.

ここで、Ｘ、ｎは一般式（１）と同義である。Ｌは独立に、水素原子又はグリシジル基である。Ｔは炭素数５～２０の不飽和複素環含有アシル基である。 The present invention also relates to a method for producing the above-mentioned modified phenoxy resin, which is characterized in that 1 mole of an alcoholic hydroxyl group equivalent of a phenoxy resin represented by the following general formula (6) is reacted with 0.05 moles or more and 2.0 moles or less of an acid anhydride represented by the following general formula (7):

Here, X and n are defined as in formula (1), L is independently a hydrogen atom or a glycidyl group, and T is an unsaturated heterocyclic ring-containing acyl group having 5 to 20 carbon atoms.

According to the present invention, it is possible to provide a modified phenoxy resin that has excellent heat resistance, solvent solubility, and adhesive properties. In addition, a resin composition using this modified phenoxy resin can provide a cured product that has excellent heat resistance. In particular, the introduction of furyl groups is beneficial in terms of carbon neutrality, since it uses a raw material that can be obtained from a biomass raw material (corn).

1 is a GPC chart of the modified phenoxy resin of Example 1. 1 is an IR chart of the modified phenoxy resin of Example 1.

The modified phenoxy resin of the present invention can be advantageously obtained by the manufacturing method of the present invention. In this specification, the cured product obtained by curing the resin composition of the present invention may be referred to as the "cured product of the present invention," and the manufacturing method of the modified phenoxy resin of the present invention may be referred to as the "manufacturing method of the present invention."

ここで、Ｘは２価の基である。Ｙは独立に、水素原子、炭素数５～２０の不飽和複素環含有アシル基、又はグリシジル基である。Ｚは独立に、水素原子又は炭素数５～２０の不飽和複素環含有アシル基であり、５モル％以上は前記アシル基である。ｎは繰り返し数であり、その平均値は１５以上５００以下である。 The modified phenoxy resin of the present invention is represented by the following general formula (1), and has a weight average molecular weight (Mw) of 5,000 to 200,000. If the Mw is small, the film-forming property and mechanical properties may be deteriorated, and if the Mw is large, the compatibility may be deteriorated and the handling of the resin may be difficult. The Mw is preferably 10,000 to 180,000, more preferably 15,000 to 160,000, further preferably 20,000 to 120,000, and particularly preferably 20,000 to 100,000. The Mw can be measured by the gel permeation chromatography method (GPC method) described in the examples.

Here, X is a divalent group. Y is independently a hydrogen atom, an unsaturated heterocyclic ring-containing acyl group having 5 to 20 carbon atoms, or a glycidyl group. Z is independently a hydrogen atom or an unsaturated heterocyclic ring-containing acyl group having 5 to 20 carbon atoms, and 5 mol % or more of the acyl group is the above-mentioned. n is the number of repetitions, and the average value is 15 or more and 500 or less.

The epoxy equivalent of the modified phenoxy resin of the present invention is not particularly limited, but is preferably 2,000 to 80,000 g/eq. Within this range, the epoxy resin can participate in the curing reaction and be incorporated into the crosslinked structure. The epoxy equivalent is more preferably 2,500 to 40,000 g/eq., even more preferably 3,000 to 30,000 g/eq., and particularly preferably 4,000 to 20,000 g/eq.

In general formula (1), the epoxy resin has a structure in which some or all of the hydrogen atoms in the hydroxyl groups of ordinary epoxy resins are replaced with unsaturated heterocyclic acyl groups having 5 to 20 carbon atoms. This structure results in low polarity, and the unsaturated heterocyclic skeleton, which is larger than the hydrogen atoms, suppresses micro-Brownian motion, resulting in excellent heat resistance. In addition, the epoxy resin has low moisture absorption and good solvent solubility.

In general formula (1), X represents a divalent group. Preferably, X is a divalent hydrocarbon group or a hydrocarbon group which may have a group such as -O-, -CO-, -S-, -COO-, -SO-, -SO ₂ - in the hydrocarbon chain. Examples of the divalent group include an aromatic skeleton representing a skeleton remaining after removing two hydroxyl groups from an aromatic diol compound, an aliphatic skeleton representing a skeleton remaining after removing two hydroxyl groups from an aliphatic diol compound, and an alicyclic skeleton representing a skeleton remaining after removing two hydroxyl groups from an alicyclic diol compound.
These groups are derived from the residual skeleton obtained by removing two glycidyloxy groups from a difunctional epoxy resin (diglycidyl ether compound), the residual skeleton obtained by removing two ester structures from a diester compound, and the residual skeleton obtained by removing two hydroxyl groups from a difunctional phenol compound.

Aromatic skeletons having a structure in which two hydroxyl groups have been removed from an aromatic diol compound include, specifically, bisphenol types that may be unsubstituted or have an alkyl group having 1 to 10 carbon atoms as a substituent, such as bisphenol A, bisphenolacetophenone, bisphenol AF, bisphenol AD, bisphenol B, bisphenol BP, bisphenol C, bisphenol E, bisphenol F, tetramethylbisphenol F, bisphenol G, bisphenol M, bisphenol S, bisphenol P, bisphenol PH, bisphenoltrimethylcyclohexane, and bisphenolcyclohexane, and unsubstituted or carbon-containing bisphenols such as hydroquinone, resorcinol, and catechol. Examples of such benzene-type compounds include dihydroxyphenyls which may have an alkyl group having 1 to 10 carbon atoms as a substituent; dihydroxynaphthalenes which may have an unsubstituted or alkyl group having 1 to 10 carbon atoms as a substituent; biphenyl-type compounds such as dihydroxybiphenyls which may have an unsubstituted or alkyl group having 1 to 10 carbon atoms as a substituent; bisphenolfluorenes and bisnaphtholfluorenes which may have an unsubstituted or alkyl group having 1 to 10 carbon atoms as a substituent, such as bisphenolfluorene and biscresolfluorene; thiodiphenol, dihydroxydiphenyl ether, and the like. In addition, for the purpose of imparting flame retardancy, 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO-HQ), 10-(2,7-dihydroxynaphthyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO-NQ), 10-(1,4-dihydroxy-2-naphthyl)-10H-9-oxa-10-phospha Examples of the phosphorus-containing phenol type include unsubstituted or C1-10 alkyl, aryl or aralkyl groups such as phenanthrene-10-oxide, diphenylphosphinyl hydroquinone, diphenylphosphinyl-1,4-dioxynaphthalene, 1,4-cyclooctylenephosphinyl-1,4-phenyldiol, and 1,5-cyclooctylenephosphinyl-1,4-phenyldiol. From the viewpoint of heat resistance, it is preferable to include bisphenol trimethylcyclohexane, bisphenol fluorene, biscresol fluorene, 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO-HQ), and 10-(2,7-dihydroxynaphthyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO-NQ).

Specific examples of aliphatic skeletons include alkylene glycol skeletons such as ethylene glycol, propylene glycol, and butylene glycol.

Specific examples of alicyclic skeletons include hydrogenated bisphenol skeletons such as hydrogenated bisphenol A, hydrogenated bisphenol F, and hydrogenated bisphenol acetophenone.

In general formula (1), Y is independently a glycidyl group, a hydrogen atom, or an unsaturated heterocyclic ring-containing acyl group having 5 to 20 carbon atoms. When Y is a glycidyl group, an epoxy group is provided at the end, when Y is a hydrogen atom, a hydroxyl group is provided at the end, and when Y is an acyl group, an ester group is provided at the end. The acyl group is represented by R-CO-, where R is an unsaturated heterocyclic ring substituent having 4 to 19 carbon atoms. It is advisable to control the ratio of these end groups depending on the application.

ここで、Ｒ^１～Ｒ^６は独立に、炭素数１～６の炭化水素基であり、ｎ１は０～３の整数であり、ｎ２は０～５の整数であり、ｎ３は０～５の整数であり、ｎ４は０～４の整数であり、ｎ５は０～６の整数であり、ｎ６は０～８の整数である。Ｗは酸素原子又は硫黄原子である。炭素数１～６の炭化水素基としては、炭素数１～５の直鎖、分岐状、又は環状のアルキル基もしくはフェニル基が好ましい。炭素数１～５のアルキル基としては、例えば、メチル基、エチル基、ｎ－プロピル基、イソプロピル基、ｎ－ブチル基、ｓｅｃ－ブチル基、イソブチル基、ｔ－ブチル基、ｎ－ペンチル基、イソペンチル基、ネオペンチル基、ｔ－ペンチル基、メチルブチル基、シクロペンチル基等が挙げられる。 In the acyl group (R-CO-), the unsaturated heterocyclic substituent having 4 to 19 carbon atoms represented by R is preferably a furyl group having 4 carbon atoms (formula (2a) below, W = oxygen atom (O)), a thienyl group having 4 carbon atoms (formula (2a) below, W = sulfur atom (S)), a pyran skeleton substituent having 5 carbon atoms (formula (2b) below, W = O), a thiopyran skeleton substituent having 5 carbon atoms (formula (2c) below, W = S), a pyridyl group having 5 to 12 carbon atoms (formula (2d) below), an azanaphthyl group (formula (2e) below), an azaanthracenyl group (formula (2f) below), or the like. Among these, a furyl group (formula (3a) below), a thienyl group (formula (3b) below), or a pyridyl group (formula (3c) below) is preferred, and a furyl group (formula (3a) below) and a thienyl group (formula (3b) below) are particularly preferred.

Here, R ¹ to R ⁶ are independently a hydrocarbon group having 1 to 6 carbon atoms, n1 is an integer of 0 to 3, n2 is an integer of 0 to 5, n3 is an integer of 0 to 5, n4 is an integer of 0 to 4, n5 is an integer of 0 to 6, and n6 is an integer of 0 to 8. W is an oxygen atom or a sulfur atom. As the hydrocarbon group having 1 to 6 carbon atoms, a linear, branched, or cyclic alkyl group or phenyl group having 1 to 5 carbon atoms is preferable. As the alkyl group having 1 to 5 carbon atoms, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, a t-pentyl group, a methylbutyl group, a cyclopentyl group, and the like can be mentioned.

In the general formula (1), Z is independently an unsaturated heterocyclic ring-containing acyl group having 5 to 20 carbon atoms or a hydrogen atom. At least 5 mol% of Z is the above acyl group, and the remainder is a hydrogen atom. The content (mol%) of the acyl group in the total Z of formula (1) is also referred to as the acylation rate. The acylation rate is preferably 10 mol% or more, more preferably 50 mol% or more, even more preferably 70 mol% or more, and particularly preferably 90 mol% or more. The upper limit of the acylation rate is 100 mol%, but the reaction may be substantially about 95 mol%. The above acyl group is the same as that exemplified for Y above, and the preferred acyl group is also the same.
When all Z are acyl groups (100 mol%), the modified phenoxy resin of the present invention does not contain secondary hydroxyl groups, and the heat resistance, solvent solubility, and adhesiveness can be further improved. On the other hand, when finely adjusting the adhesiveness to metal, for example, by leaving a part of Z as hydrogen atoms, it is possible to intentionally allow an appropriate amount of secondary hydroxyl groups to be present in the modified phenoxy resin of the present invention within a range that does not significantly affect other physical properties including heat resistance. The fewer hydrogen atoms there are as Z, the more improved the dielectric properties and moisture resistance can be obtained.
It is most preferable that the acyl group only has an unsaturated heterocyclic ring-containing acyl group having 5 to 20 carbon atoms, but other acyl groups may be present other than the unsaturated heterocyclic ring-containing acyl group having 5 to 20 carbon atoms as long as it does not have an adverse effect. In this case, the other acyl groups preferably account for less than 50 mol %, more preferably 20 mol % or less, and even more preferably 10 mol % or less of the total acyl groups.

In general formula (1), n is the number of repetitions and is an average value. The value ranges from 15 to 500. From the viewpoint of moldability and handleability, it is preferably from 17 to 400, and more preferably from 20 to 300. The number n can be calculated from the number average molecular weight (Mn) obtained by the GPC method.

The modified phenoxy resin of the present invention is a resin in which a part or all of the secondary hydroxyl groups of a normal epoxy resin are acylated with an unsaturated heterocycle-containing acyl group having 5 to 20 carbon atoms, and can be obtained by various methods. For example, the following method is a preferred production method.
(A): A production method in which a bifunctional epoxy resin represented by the above formula (4) is reacted with a diester compound of an unsaturated heterocycle-containing acyl group represented by formula (5). Hereinafter, this method may be referred to as production method (A).
(B): A production method in which a phenoxy resin represented by the above formula (6) (sometimes referred to as phenoxy resin (a) to distinguish it from the modified phenoxy resin of the present invention) is reacted with an acid component (acylating agent) such as an acid anhydride of an organic acid, an organic acid halide, or an organic acid ester. Hereinafter, this method may be referred to as production method (B).
The phenoxy resins modified with an unsaturated heterocycle-containing acyl group obtained by the production methods (A) and (B) are the modified phenoxy resins of the present invention and are represented by the same general formula (1).

The production method (A) is a method of reacting a bifunctional epoxy resin represented by the following formula (4) with an unsaturated heterocycle-containing diester compound represented by the following formula (5).

In formula (4), G is a glycidyl group. m is the number of repetitions, and the average value is 0 to 6, preferably 0 to 3, more preferably 0 to 1, and even more preferably 0 to 0.3.
In formula (5), Q is an unsaturated heterocyclic ring-containing acyl group having 5 to 20 carbon atoms or a hydrogen atom.
In formula (5), 5 mol % or more of Q is an unsaturated heterocyclic ring-containing acyl group having 5 to 20 carbon atoms, and the remainder is a hydrogen atom. Here, the compound represented by formula (5) may be a mixture of two or more selected from a diester compound in which both Qs are the above-mentioned acyl group, a monoester compound in which one is the above-mentioned acyl group and the other is a hydrogen atom, and a diphenol compound in which both Qs are hydrogen atoms. The compound represented by formula (5) is called a diester compound. The diester compound may be a diester compound in which both Qs are the above-mentioned acyl group, or the main component (preferably 5 mol % or more, more preferably 50 mol % or more, even more preferably 70 mol % or more, particularly preferably 90 mol % or more) is the compound (mixture). That is, the molar ratio of acyl groups to hydrogen atoms (acyl groups/hydrogen atoms) is 100/0 to 5/95.
^X1 in formula (4) and ^X2 in formula (5) are selected to give X in formula (1). Also, ^X1 and ^X2 may be the same or different.

The bifunctional epoxy resin used in the production method (A) is an epoxy resin represented by formula (4), and examples thereof include an epoxy resin obtained by reacting a bifunctional phenol compound represented by HO-X ¹ -OH with epihalohydrin in the presence of an alkali metal compound. Here, X ¹ is the same as X ¹ in the above formula (4). The epoxy equivalent of the bifunctional epoxy resin represented by formula (4) is preferably 100 to 400 g/eq., and the upper limit is more preferably 300 g/eq. or less. The m value in formula (4) is preferably 0 to 1, and more preferably 0.3 or less.

Examples of epihalohydrin include epichlorohydrin and epibromohydrin.
Examples of alkali metal compounds include alkali metal hydroxides such as sodium hydroxide, lithium hydroxide, and potassium hydroxide; alkali metal salts such as sodium carbonate, sodium bicarbonate, sodium chloride, lithium chloride, and potassium chloride; alkali metal alkoxides such as sodium methoxide and sodium ethoxide; alkali metal salts of organic acids such as sodium acetate and sodium stearate; alkali metal phenoxides, sodium hydride, and lithium hydride.

In the reaction between a bifunctional phenolic compound and epihalohydrin to obtain the raw material epoxy resin, an alkali metal compound is preferably used in an amount of 0.80 to 1.20 times by mole, more preferably 0.85 to 1.05 times by mole, based on the functional groups in the bifunctional phenolic compound. If the amount is less than this, the amount of hydrolyzable chlorine remaining may be large. The alkali metal compound is used in the form of an aqueous solution, alcohol solution, or solid.

In the epoxidation reaction, an excess amount of epihalohydrin is used relative to the bifunctional phenolic compound. Usually, 1.5 to 15 moles of epihalohydrin are used per mole of functional group in the bifunctional phenolic compound, preferably 2 to 10 moles, more preferably 5 to 8 moles. If the amount is more than this, the production efficiency decreases, and if it is less than this, the amount of high molecular weight epoxy resin produced increases, and it may become unsuitable as a raw material for the modified phenoxy resin of the present invention.

The epoxidation reaction is usually carried out at a temperature of 120°C or less. If the reaction temperature is high, the amount of so-called difficult to hydrolyze chlorine increases, making it difficult to achieve high purification. The temperature is preferably 100°C or less, and more preferably 85°C or less.

When a bifunctional phenol compound is reacted with epihalohydrin, m is usually greater than 0. In order to make m 0, an epoxy resin produced by a known method can be highly purified by distillation, crystallization, or the like, or a bifunctional phenol compound can be allylated and then epoxidized by oxidizing the olefin portion.

The unsaturated heterocycle-containing compound (diester compound) represented by the above formula (5) can be obtained, for example, by acylation of a bifunctional phenol compound represented by HO-X ² -OH with an acid anhydride of an unsaturated heterocycle-containing organic acid, a halide of an unsaturated heterocycle-containing organic acid, or an unsaturated heterocycle-containing organic acid through a condensation reaction.

By using a bifunctional epoxy resin in which m in formula (4) is 0 as the raw material, the modified phenoxy resin of the present invention does not contain secondary hydroxyl groups, and heat resistance and solvent solubility can be further improved. In addition, for example, when fine-tuning adhesion to metals, a bifunctional epoxy resin with an appropriate m number can be used to intentionally allow an appropriate amount of secondary hydroxyl groups to be present in the modified phenoxy resin, as long as it does not significantly affect other physical properties, including heat resistance.

The amount of the bifunctional epoxy resin and the unsaturated heterocycle-containing compound (diester compound) used is preferably 0.8 to 1.05 equivalents of the ester group (acyloxy group) or hydroxyl group in the unsaturated heterocycle-containing compound relative to 1 equivalent of the epoxy group, more preferably 0.9 to 1.0 equivalents. This equivalent ratio is preferable because it is easy to proceed with high molecular weight in a state in which the epoxy group is present at the molecular end. It is also possible to replace a part of the unsaturated heterocycle-containing compound with the above-mentioned diphenol compound. This allows the physical properties to be finely adjusted by deliberately allowing an appropriate amount of secondary hydroxyl groups to be present in the modified phenoxy resin. The amount of the ester group in the unsaturated heterocycle-containing compound is preferably 0.05 to 1.0 equivalents relative to 1 equivalent of the epoxy group. Here, the molar ratio of the ester group (acyloxy group) to the hydroxyl group (acyloxy group/hydroxyl group) in the unsaturated heterocycle-containing compound is 100/0 to 5/95. This makes it possible to satisfy the requirement that the acyl group content in all Z in formula (1) be 5 mol % or more.
In the production method (A), the molecular weight is increased to produce the modified phenoxy resin of the present invention, and at the same time, a portion of the hydroxyl groups of this phenoxy resin is esterified.

In the manufacturing method (A), a catalyst may be used. The catalyst may be any compound that has catalytic ability to promote the reaction between the epoxy group and the ester bond. Examples of the catalyst include tertiary amines, cyclic amines, imidazoles, organic phosphorus compounds, and quaternary ammonium salts. These catalysts may be used alone or in combination of two or more.

Examples of tertiary amines include, but are not limited to, triethylamine, tri-n-propylamine, tri-n-butylamine, triethanolamine, benzyldimethylamine, and 2,4,6-tris(dimethylaminomethyl)phenol.

Examples of cyclic amines include, but are not limited to, 1,4-diazabicyclo[2,2,2]octane (DABCO), 1,8-diazabicyclo[5,4,0]undecene-7 (DBU), 1,5-diazabicyclo[4,3,0]nonene-5 (DBN), N-methylmorpholine, pyridine, and 4-dimethylaminopyridine (DMAP).

Examples of imidazoles include, but are not limited to, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, and 1-benzyl-2-phenylimidazole.

Examples of organic phosphorus compounds include phosphines such as tri-n-propylphosphine, tri-n-butylphosphine, diphenylmethylphosphine, triphenylphosphine, tris(p-tolyl)phosphine, tricyclohexylphosphine, tri(t-butyl)phosphine, tris(p-methoxyphenyl)phosphine, paramethylphosphine, 1,2-bis(dimethylphosphino)ethane, and 1,4-bis(diphenylphosphino)butane; tetramethylphosphonium bromide, tetramethylphosphonium iodide, tetramethylphosphonium hydroxide, tetrabutylphosphonium bromide, and tetrabutylphosphonium iodide. Examples of phosphonium salts include, but are not limited to, phosphonium hydroxide, trimethylcyclohexylphosphonium chloride, trimethylcyclohexylphosphonium bromide, trimethylbenzylphosphonium chloride, trimethylbenzylphosphonium bromide, tetraphenylphosphonium bromide, triphenylmethylphosphonium bromide, triphenylmethylphosphonium iodide, triphenylethylphosphonium chloride, triphenylethylphosphonium bromide, triphenylethylphosphonium iodide, triphenylbenzylphosphonium chloride, and triphenylbenzylphosphonium bromide.

Examples of quaternary ammonium salts include, but are not limited to, tetramethylammonium chloride, tetramethylammonium bromide, tetramethylammonium hydroxide, triethylmethylammonium chloride, tetraethylammonium chloride, tetraethylammonium bromide, tetraethylammonium iodide, tetrapropylammonium bromide, tetrapropylammonium hydroxide, tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium iodide, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, benzyltrimethylammonium hydroxide, benzyltributylammonium chloride, and phenyltrimethylammonium chloride.

Among the catalysts listed above, 4-dimethylaminopyridine, 1,4-diazabicyclo[2,2,2]octane, 1,8-diazabicyclo[5,4,0]undecene-7, 1,5-diazabicyclo[4,3,0]nonene-5, 2-ethyl-4-methylimidazole, tris(p-tolyl)phosphine, tricyclohexylphosphine, tri(t-butyl)phosphine, and tris(p-methoxyphenyl)phosphine are preferred, and 4-dimethylaminopyridine, 1,8-diazabicyclo[5,4,0]undecene-7, 1,5-diazabicyclo[4,3,0]nonene-5, and 2-ethyl-4-methylimidazole are particularly preferred.

The amount of catalyst used is usually 0.001 to 1 mass% of the reaction solids, but when these compounds are used as catalysts, the catalysts remain as residues in the resulting modified phenoxy resin, which may deteriorate the insulating properties of the cured product or shorten the pot life of the composition, so the nitrogen content derived from the catalyst in the modified phenoxy resin is preferably 0.5 mass% or less, more preferably 0.3 mass% or less. The phosphorus content derived from the catalyst in the modified phenoxy resin is preferably 0.5 mass% or less, more preferably 0.3 mass%.

In the manufacturing method (A), a reaction solvent may be used. Any solvent that dissolves the modified phenoxy resin may be used. Examples of the solvent include aromatic solvents, ketone solvents, amide solvents, glycol ether solvents, and ester solvents. These solvents may be used alone or in combination of two or more.

Examples of aromatic solvents include benzene, toluene, and xylene.

Examples of ketone solvents include acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, 2-heptanone, 4-heptanone, 2-octanone, cyclohexanone, acetylacetone, diisobutyl ketone, isophorone, methylcyclohexanone, and acetophenone.

Examples of amide solvents include formamide, N-methylformamide, N,N-dimethylformamide (DMF), acetamide, N-methylacetamide, N,N-dimethylacetamide, 2-pyrrolidone, and N-methylpyrrolidone.

Examples of glycol ether solvents include ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and ethylene glycol mono-n-butyl ether; diethylene glycol monoalkyl ethers such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol mono-n-butyl ether; propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, and propylene glycol mono-n-butyl ether; ethylene glycol dialkyl ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and ethylene glycol dibutyl ether; polyethylene glycol dialkyl ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, and triethylene glycol dibutyl ether; propylene glycol dimethyl ether, propylene glycol diethyl ether, and propylene glycol dibutyl ether; Examples of the glycol dialkyl ethers include polypropylene glycol dialkyl ethers such as dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol dibutyl ether, tripropylene glycol dimethyl ether, tripropylene glycol diethyl ether, and tripropylene glycol dibutyl ether; ethylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, and ethylene glycol monobutyl ether acetate; polyethylene glycol monoalkyl ether acetates such as diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, triethylene glycol monomethyl ether acetate, triethylene glycol monoethyl ether acetate, and triethylene glycol monobutyl ether acetate; and propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and propylene glycol monobutyl ether acetate.

Examples of ester solvents include methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, benzyl acetate, ethyl propionate, ethyl butyrate, and butyl butyrate.

Other solvents include, for example, dimethyl sulfoxide, sulfolane, dioxane, valerolactone, gamma-butyrolactone, etc.

In the manufacturing method (A), the solids concentration during the reaction is preferably 35 to 100% by mass. More preferably, it is 50 to 90% by mass, and even more preferably, it is 70 to 90% by mass. If a highly viscous product is produced during the reaction, the reaction can be continued by adding additional solvent. After the reaction is completed, the solvent can be removed or further added as necessary.

The reaction temperature is within a range in which the catalyst used does not decompose. If the reaction temperature is too high, the catalyst may decompose and the reaction may stop, or the modified phenoxy resin produced may deteriorate. If the reaction temperature is too low, the reaction may not proceed sufficiently to achieve the desired molecular weight. Therefore, the reaction temperature is preferably 50 to 230°C, more preferably 120 to 200°C. The reaction time is usually 1 to 12 hours, preferably 3 to 10 hours. When using a low-boiling solvent such as acetone or methyl ethyl ketone, the reaction temperature can be ensured by using an autoclave to carry out the reaction under high pressure. If it is necessary to remove the heat of reaction, this is usually done by evaporating, condensing, and refluxing the solvent used using the heat of reaction, indirect cooling, or a combination of these.

ここで、Ｘ、ｎは一般式（１）と同義である。Ｌは独立に、水素原子又はグリシジル基である。Ｔは炭素数５～２０の不飽和複素環含有アシル基である。 Next, the production method (B) of the present invention will be described.
The production method (B) is a method for obtaining an unsaturated heterocycle-containing modified phenoxy resin having a Mw of 5,000 to 200,000, i.e., the modified phenoxy resin of the general formula (1) of the present invention, by reacting a phenoxy resin (a) represented by the following formula (6) with an unsaturated heterocycle-containing acid anhydride represented by the following formula (7) in an amount of 0.05 mol or more and 2.0 mol or less per mol of the alcoholic hydroxyl group equivalent of the phenoxy resin (a).

Here, X and n are defined as in formula (1), L is independently a hydrogen atom or a glycidyl group, and T is an unsaturated heterocyclic ring-containing acyl group having 5 to 20 carbon atoms.

The phenoxy resin (a) represented by formula (6) used as the raw material has a repeat number n of 15 to 500. Such phenoxy resin (a) can be obtained by a conventionally known method. Examples of such a method include a method of reacting bifunctional phenolic compounds with epihalohydrin in the presence of an alkali metal compound (hereinafter referred to as the "single-step method"), and a method of reacting bifunctional epoxy resins with bifunctional phenolic compounds in the presence of a catalyst (hereinafter referred to as the "two-step method"). Phenoxy resin (a) may be obtained by any of the methods, but since phenoxy resins are generally easier to obtain by the two-step method than by the one-step method, it is preferable to use the two-step method.

The weight average molecular weight and epoxy equivalent of the phenoxy resin (a) can be produced within the desired range by appropriately adjusting the molar ratio of the epihalohydrin and bifunctional phenolic compounds in the one-stage process, and by appropriately adjusting the molar ratio of the bifunctional epoxy resins and bifunctional phenolic compounds in the two-stage process.

Examples of bifunctional phenol compounds used in the one-stage and two-stage production include bisphenols such as bisphenol A, bisphenol F, bisphenol S, bisphenol B, bisphenol E, bisphenol C, bisphenolacetophenone, bisphenolfluorene, dihydroxybiphenyl ether, and dihydroxybiphenyl thioether, biphenols such as 4,4'-biphenol and 2,4'-biphenol, 1,1-bi-2-naphthol, catechol, resorcin, hydroquinone, and dihydroxynaphthalene. In addition, multiple types of these bifunctional phenol compounds may be used in combination.

First, the one-stage process will be described.
In the case of the one-step process, 1.0 to 1.5 moles, preferably 1.0 to 1.2 moles, more preferably 1.005 to 1.02 moles of epihalohydrin are reacted in a non-reactive solvent in the presence of an alkali metal compound with 1 mole of bifunctional phenolic compounds, and a condensation reaction is carried out so that the epihalohydrin is consumed and the weight average molecular weight is 5,000 or more, thereby obtaining a high molecular weight epoxy resin. After the reaction is completed, it is necessary to remove the by-product salt by filtration or washing with water. Examples of the alkali metal compound include the same alkali metal compounds as those used in the production of the bifunctional epoxy resin represented by formula (4) used in the production method (A) of the present invention.

This reaction can be carried out under normal pressure or reduced pressure. In the case of reactions under normal pressure, the reaction temperature is usually preferably 20 to 200°C, more preferably 30 to 170°C, even more preferably 40 to 150°C, and particularly preferably 50 to 100°C. In the case of reactions under reduced pressure, the reaction temperature is preferably 20 to 100°C, more preferably 30 to 90°C, and even more preferably 35 to 80°C. If the reaction temperature is within this range, side reactions are unlikely to occur and the reaction is easy to proceed. The reaction pressure is usually normal pressure. In addition, when it is necessary to remove the heat of reaction, this is usually done by evaporation/condensation/reflux method of the solvent used using the reaction heat, indirect cooling method, or a combination of these.

As the reactive solvent, in addition to the reaction solvents exemplified in the production method (A) of the present invention, alcohols such as ethanol, isopropyl alcohol, and butyl alcohol can also be used. Only one type may be used, or two or more types may be used in combination.

Next, the two-stage method will be described.
As the bifunctional epoxy resins serving as the starting epoxy resin in the two-stage process, those similar to the bifunctional epoxy resin represented by formula (4) used in the production process (A) of the present invention are used.

Examples of bifunctional epoxy resins that are used as raw materials in the two-stage process include bisphenol type epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenolacetophenone type epoxy resin, diphenyl sulfide type epoxy resin, and diphenyl ether type epoxy resin, biphenol type epoxy resin, diphenyldicyclopentadiene type epoxy resin, alkylene glycol type epoxy resin, naphthalene type epoxy resin, benzene type epoxy resin, and aliphatic cyclic epoxy resin. These epoxy resins may be substituted with non-detrimental substituents such as alkyl groups and aryl groups. Multiple types of these epoxy resins may be used in combination.

The amount of bifunctional epoxy resins used is preferably 0.9 to 1.2 moles per 1.0 mole of bifunctional phenolic compounds, more preferably 1.0 to 1.1 moles, even more preferably 1.0 to 1.05 moles, and particularly preferably 1.01 to 1.03 moles. If the amount of bifunctional epoxy resins used is within this range, it is preferable because it is easier to promote high molecular weight formation with epoxy groups at the molecular ends.

In the case of the two-stage method, a catalyst can be used, and any compound having catalytic ability to promote the reaction between the epoxy group and the phenolic hydroxyl group can be used. For example, the same catalysts as those exemplified in the production method (A) of the present invention can be used. In addition, the alkali metal compounds used in the production of the bifunctional epoxy resin represented by formula (4) can also be used. These catalysts can be used alone or in combination of two or more types. The amount used is also the same as the amount exemplified in the production method (A) of the present invention.

In the case of the two-stage method, a solvent may be used. Any solvent may be used as long as it dissolves the modified phenoxy resin and does not adversely affect the reaction. For example, the same solvents as those exemplified in the manufacturing method (A) of the present invention may be used. These solvents may be used alone or in combination of two or more.

The amount of solvent used can be appropriately selected depending on the reaction conditions. For example, in the case of a two-stage process, a solids concentration of 35 to 95% by mass is preferred. If a highly viscous product is produced during the reaction, the reaction can be continued by adding solvent during the reaction. After the reaction is completed, the solvent can be removed by distillation or the like as necessary, or more solvent can be added.

The reaction temperature is within a range in which the catalyst used does not decompose. If the reaction temperature is too high, the catalyst may decompose and the reaction may stop, or the phenoxy resin produced may deteriorate. If the reaction temperature is too low, the reaction may not proceed sufficiently to achieve the desired molecular weight. Therefore, the reaction temperature is preferably 50 to 230°C, more preferably 100 to 210°C, and even more preferably 120 to 200°C. The reaction time is usually 1 to 12 hours, and preferably 3 to 10 hours. When using a low-boiling 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. If it is necessary to remove the heat of reaction, this is usually done by evaporating, condensing, and refluxing the solvent used using the heat of reaction, indirect cooling, or a combination of these.

The hydroxyl groups in the phenoxy resin (a) thus obtained, represented by formula (6), are acylated to obtain the unsaturated heterocycle-containing modified epoxy resin of the present invention. Acylation can be achieved not only by direct esterification, but also by methods such as transesterification.

As the acid component used for acylation, for example, the organic acids containing the above-mentioned unsaturated heterocycles such as furan carboxylic acid, thiophene carboxylic acid, pyridine carboxylic acid, etc., acid anhydrides of the organic acids, halides of the organic acids, esters of the organic acids, etc. can be used. Preferably, it is an acid anhydride of an organic acid containing an unsaturated heterocycle represented by formula (7).

Examples of acid anhydrides of unsaturated heterocyclic organic acids include bis(2-furancarboxylic acid) anhydride and bis(2-thiophenecarboxylic acid) anhydride. Examples of esters of unsaturated heterocyclic organic acids include ethyl 2-furancarboxylate and methyl 2-thiophene. Examples of halides of unsaturated heterocyclic organic acids include 2-furancarboxylic acid chloride and 2-thiophene acid chloride.

As the unsaturated heterocyclic ring-containing compound to be used for esterification, preferred are halides of unsaturated heterocyclic ring-containing organic acids such as 2-furancarboxylic acid chloride and 2-thiophenecarboxylic acid chloride, and acid anhydrides of unsaturated heterocyclic ring-containing organic acids such as bis(2-furancarboxylic acid) anhydride and bis(2-thiophenecarboxylic acid) anhydride. In order to avoid the need for washing with water after esterification and to avoid the inclusion of halogens, which are undesirable in electrical material applications, unsaturated heterocyclic ring-containing acid anhydrides such as bis(2-furancarboxylic acid) anhydride and bis(2-thiophenecarboxylic acid) anhydride are particularly preferred.

The charge ratio of an acid component such as an organic acid, an acid anhydride of an organic acid, an organic acid halide, or an ester of an organic acid used for esterifying the hydroxyl groups of the phenoxy resin (a) when reacting with the phenoxy resin (a) may be the same as the target esterification ratio, or if the reactivity is low, an excess of the acid component relative to the hydroxyl groups may be charged and reacted to the target esterification ratio, after which the unreacted acid component may be removed.

It is preferable to react 0.05 to 2.0 moles of organic acid, anhydride of organic acid, halide of organic acid, ester of organic acid, etc. with 1 mole of alcoholic hydroxyl group equivalent of phenoxy resin (a), more preferably 0.05 to 1.5 moles, and particularly preferably 0.05 to 1.2 moles.

The alcoholic hydroxyl group equivalent of the phenoxy resin (a) is limited to the alcoholic hydroxyl groups generated by the ring-opening reaction of the epoxy groups in the above manufacturing methods (A) and (B), and does not include the alcoholic hydroxyl groups already contained in the raw material epoxy resin.

When directly esterifying with an acid component, it can be carried out while dehydrating using various esterification catalysts, such as acid catalysts such as paratoluenesulfonic acid and phosphoric acid, and metal catalysts such as tetraisopropyl titanate, tetrabutyl titanate, dibutyltin oxide, dioctyltin oxide, and zinc chloride. It is usually preferably carried out at 100 to 250°C under a nitrogen atmosphere, and more preferably at 130 to 230°C.

When an acid halide or an acid anhydride is used for esterification, the acid produced can be removed by any of the following methods, or a combination of these: neutralizing with a basic compound and then filtering the salt; neutralizing with a basic compound and then washing with water; washing with water without neutralization; or removing the acid by distillation or adsorption. When removing an acid with a lower boiling point than the reaction solvent, it is preferable to remove it by distillation.

When phenoxy resin is esterified by transesterification, it is usually desirable to carry out the esterification under a nitrogen atmosphere while dealcoholizing using a known esterification catalyst such as dibutyltin oxide, dioctyltin oxide, stannoxane catalyst, tetraisopropyl titanate, tetrabutyl titanate, lead acetate, zinc acetate, antimony trioxide, or other organometallic catalyst, acid catalyst such as hydrochloric acid, sulfuric acid, phosphoric acid, or sulfonic acid, or basic catalyst such as lithium hydroxide or sodium hydroxide.

In the manufacturing method (B), a reaction solvent may be used. Any solvent that dissolves the phenoxy resin (a) and the modified phenoxy resin may be used. Examples of the solvent include the solvents exemplified in the manufacturing method (A). These solvents may be the same as or different from those used in the preparation of the modified phenoxy resin. In addition, only one type of solvent may be used, or two or more types may be used in combination.

The resin composition of the present invention is a resin composition containing at least the modified phenoxy resin of the present invention and a curing agent. In addition, various additives such as epoxy resins, inorganic fillers, coupling agents, and antioxidants can be appropriately blended into the resin composition of the present invention as necessary. The resin composition of the present invention gives a cured product that fully satisfies the various physical properties required for various applications.

A resin composition can be prepared by blending a curing agent with the modified phenoxy resin of the present invention. In the present invention, the curing agent refers to a substance that contributes to the crosslinking reaction and/or chain extension reaction with the modified phenoxy resin. In the present invention, even substances that are normally called "curing accelerators" are considered to be curing agents as long as they contribute to the crosslinking reaction and/or chain extension reaction of the modified phenoxy resin.

The content of the curing agent in the resin composition of the present invention is preferably 0.1 to 100 parts by mass in terms of solid content per 100 parts by mass of the solid content of the modified phenoxy resin of the present invention. The upper limit is more preferably 80 parts by mass or less, and even more preferably 60 parts by mass or less.

In the resin composition of the present invention, when an epoxy resin described later is contained, the weight ratio of the solid content of the modified phenoxy resin of the present invention to the epoxy resin is 99/1 to 1/99. In the present invention, the "solid content" means the components excluding the solvent, and includes not only solid modified phenoxy resins and epoxy resins, but also semi-solid and viscous liquid substances. In addition, the "resin component" means the total of the modified phenoxy resin of the present invention and the epoxy resin described later.
In addition, when the modified phenoxy resin of the present invention is used together with an epoxy resin described later, the curing agent is preferably contained in an amount of 0.1 to 100 parts by mass as solid content per 100 parts by mass of the total solid content of the modified phenoxy resin and the epoxy resin, and the upper limit is more preferably 80 parts by mass or less, and even more preferably 60 parts by mass or less.

The curing agent used in the resin composition of the present invention, including the case where the epoxy resin described below is included, is not particularly limited, and any agent generally known as an epoxy resin curing agent can be used. Examples include phenolic resins, amide compounds, imidazole compounds, cyanate ester compounds, active ester compounds, amine compounds, etc. From the viewpoint of improving heat resistance, preferred agents include phenolic resins, amide compounds, imidazole compounds, etc., and from the viewpoint of improving water resistance, preferred agents include active ester compounds. These curing agents may be used alone or in combination of two or more types.

Examples of phenolic resins 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 novolac, bisphenol A novolac, o-cresol novolac, m-cresol novolac, p-cresol novolac, xylenol novolac, poly-p-hydroxystyrene, hydroquinone, resorcinol, catechol, t-butylcatechol, t -butylhydroquinone, fluoroglycinol, pyrogallol, t-butylpyrogallol, 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-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2,8-dihydroxynaphthalene, allylated products or polyallylated products of the above dihydroxynaphthalenes, allylated bisphenol A, allylated bisphenol F, allylated phenol novolak, allylated pyrogallol, and the like.

Examples of amide compounds include dicyandiamide and its derivatives, polyamide resins, etc.

Examples of imidazole compounds 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'-methylimidazo Examples of imidazoles include 2,4-diamino-6-[2'-ethyl-4'-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-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, and adducts of epoxy resins and the above imidazoles. Note that since imidazoles have catalytic activity, they can generally be classified as curing accelerators, which will be described later, but in the present invention they are classified as curing agents.

The cyanate ester compound is not particularly limited as long as it has two or more cyanato groups (cyanate ester groups) in one molecule. For example, there are novolac-type cyanate ester curing agents such as phenol novolac type and alkylphenol novolac type, naphthol aralkyl type cyanate ester curing agents, biphenyl alkyl type cyanate ester curing agents, dicyclopentadiene type cyanate ester curing agents, bisphenol type cyanate ester curing agents such as bisphenol A type, bisphenol F type, bisphenol E type, tetramethyl bisphenol F type, and bisphenol S type, and prepolymers of these partially converted to triazine.
Examples of active ester compounds include reaction products of polyfunctional phenol compounds and aromatic carboxylic acids as described in Japanese Patent No. 5,152,445. Commercially available products include Epiclon HPC-8000-65T (manufactured by DIC Corporation), but are not limited to these.

Other curing agents that can be used in the resin composition of the present invention include, for example, acrylic ester resins, melamine resins, urea resins, cationic polymerization agents, acid anhydrides, organic phosphines, phosphonium salts, tetraphenylboron salts, hydrazide compounds, boron halide amine complexes, polymercaptan compounds, isocyanate compounds, polyisocyanate compounds, blocked isocyanate compounds, etc. These other curing agents may be used alone or in any combination and ratio of two or more.

The resin composition of the present invention may contain an epoxy resin. By using an epoxy resin, it is possible to compensate for insufficient physical properties and improve various physical properties. The epoxy resin is preferably one having two or more epoxy groups in the molecule, and more preferably an epoxy resin having three or more epoxy groups. Examples include polyglycidyl ether compounds, polyglycidyl amine compounds, polyglycidyl ester compounds, alicyclic epoxy compounds, and other modified epoxy resins. These epoxy resins may be used alone, or two or more types of the same type of epoxy resin may be used in combination, or different types of epoxy resins may be used in combination.

Examples of the polyglycidyl ether compound include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol AF type epoxy resins, bisphenol Z type epoxy resins, bisphenol fluorene type epoxy resins, diphenyl sulfide type epoxy resins, diphenyl ether type epoxy resins, naphthalene type epoxy resins, hydroquinone type epoxy resins, resorcinol type epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, alkyl novolac type epoxy resins, styrenated phenol novolac type epoxy resins, bisphenol novolac type epoxy resins, naphthol novolac type epoxy resins, phenol aralkyl type epoxy resins, β-naphthol aralkyl type epoxy resins, naphthalenediol aralkyl type epoxy resins, α-naphthol aralkyl type epoxy resins, biphenyl aralkyl phenol type epoxy resins, biphenyl type epoxy resins, triphenylmethane type epoxy resins, dicyclopentadiene type epoxy resins, alkylene glycol type epoxy resins, and various epoxy resins such as aliphatic cyclic epoxy resins can be used.

Examples of polyglycidylamine compounds include diaminodiphenylmethane type epoxy resins, metaxylenediamine type epoxy resins, 1,3-bisaminomethylcyclohexane type epoxy resins, isocyanurate type epoxy resins, aniline type epoxy resins, hydantoin type epoxy resins, aminophenol type epoxy resins, etc.

Examples of polyglycidyl ester compounds include dimer acid type epoxy resins and trimellitic acid type epoxy resins.

Examples of alicyclic epoxy compounds include alicyclic epoxy resins such as Celloxide 2021 (manufactured by Daicel Corporation).

Other modified epoxy resins include, for example, urethane-modified epoxy resins, oxazolidone ring-containing epoxy resins, epoxy-modified polybutadiene rubber derivatives, carboxyl-terminated butadiene nitrile rubber (CTBN)-modified epoxy resins, polyvinylarene polyoxides (e.g., divinylbenzene dioxide, trivinylnaphthalene trioxide, etc.), etc.

When the modified phenoxy resin of the present invention and an epoxy resin are used in the resin composition of the present invention, the amount of the modified phenoxy resin in the total components of the modified phenoxy resin and the epoxy resin as solids is preferably 1 to 99 mass %, more preferably 50 mass % or more, and even more preferably 80 mass % or more.

The resin composition of the present invention may contain a solvent or reactive diluent to adjust the viscosity of the resin composition appropriately when handling the composition to form a coating film. In the resin composition of the present invention, the solvent or reactive diluent is used to ensure the ease of handling and workability in molding the resin composition, and there is no particular limit to the amount used. In the present invention, the term "solvent" and the aforementioned term "solvent" are used separately depending on the form of use, but the same or different substances may be used independently.

Examples of solvents that may be contained in the resin composition of the present invention include ketones such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, and cyclohexanone, esters such as ethyl acetate, 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 above-mentioned solvents may be used alone or in any combination and ratio of two or more.

Examples of reactive diluents include monofunctional glycidyl ethers such as allyl glycidyl ether, bifunctional glycidyl ethers such as propylene glycol diglycidyl ether, polyfunctional glycidyl ethers such as trimethylolpropane polyglycidyl ether, glycidyl esters, and glycidyl amines.

These solvents or reactive diluents are preferably used in an amount of 90% by mass or less as non-volatile matter, and the appropriate type and amount used are appropriately selected depending on the application. For example, for printed wiring board applications, polar solvents with a boiling point of 160°C or less, such as methyl ethyl ketone, acetone, and 1-methoxy-2-propanol, are preferred, and the amount used is preferably 40 to 80% by mass as non-volatile matter. For adhesive film applications, for example, ketones, acetates, carbitols, aromatic hydrocarbons, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, and the like are preferred, and the amount used is preferably 30 to 60% by mass as non-volatile matter.

In the resin composition of the present invention, a curing accelerator or catalyst can be used as necessary. Examples of the curing accelerator or catalyst include imidazole compounds, tertiary amines, phosphorus compounds such as phosphines, metal compounds, Lewis acids, amine complex salts, etc. These may be used alone or in combination of two or more types.

The amount of the curing accelerator or catalyst may be appropriately selected depending on the intended use, but 0.01 to 15 parts by mass is used as necessary for 100 parts by mass of the epoxy resin component in the resin composition. Preferably, it is 0.01 to 10 parts by mass, more preferably 0.05 to 8 parts by mass, even more preferably 0.1 to 5 parts by mass, and particularly preferably 0.1 to 1.0 part by mass. By using a curing accelerator or catalyst, it is possible to lower the curing temperature and shorten the curing time.

In the resin composition of the present invention, various known flame retardants can be used to improve the flame retardancy of the resulting cured product, as long as the reliability is not reduced. Examples of flame retardants that can be used include halogen-based flame retardants, phosphorus-based flame retardants, nitrogen-based flame retardants, silicone-based flame retardants, inorganic flame retardants, and organic metal salt-based flame retardants. From an environmental perspective, halogen-free flame retardants are preferred, and phosphorus-based flame retardants are particularly preferred. These flame retardants may be used alone, or two or more of the same type of flame retardants may be used in combination, or different types of flame retardants may be used in combination.

The resin composition of the present invention may contain components other than those listed above (sometimes referred to as "other components" in the present invention) for the purpose of further improving its functionality. Such other components include fillers, thermoplastic resins, thermosetting resins, photocurable resins, UV inhibitors, antioxidants, coupling agents, plasticizers, fluxes, thixotropic agents, smoothing agents, colorants, pigments, dispersants, emulsifiers, elasticity reducing agents, release agents, defoamers, ion trapping agents, etc.

Examples of fillers include inorganic fillers such as fused silica, crystalline silica, alumina, silicon nitride, boron nitride, aluminum nitride, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, boehmite, talc, mica, clay, calcium carbonate, magnesium carbonate, barium carbonate, zinc oxide, titanium oxide, magnesium oxide, magnesium silicate, calcium silicate, zirconium silicate, barium sulfate, and carbon; fibrous fillers such as carbon fiber, glass fiber, alumina fiber, silica alumina fiber, silicon carbide fiber, polyester fiber, cellulose fiber, aramid fiber, and ceramic fiber; and fine particle rubber.

The resin composition of the present invention may be used in combination with a thermoplastic resin other than the modified phenoxy resin of the present invention. Examples of thermoplastic resins include phenoxy resins other than those of the present invention, polyurethane resins, polyester resins, polyethylene resins, polypropylene resins, polystyrene resins, ABS resins, AS resins, vinyl chloride resins, polyvinyl acetate resins, polymethyl methacrylate resins, polycarbonate resins, polyacetal resins, cyclic polyolefin resins, polyamide resins, thermoplastic polyimide resins, polyamideimide resins, polytetrafluoroethylene resins, polyetherimide resins, polyphenylene ether resins, modified polyphenylene ether resins, polyethersulfone resins, polysulfone resins, polyetheretherketone resins, polyphenylene sulfide resins, polyvinyl formal resins, and the like. In terms of compatibility, phenoxy resins other than those of the present invention are preferred.

Other components include organic pigments such as quinacridone, azo, and phthalocyanine pigments, inorganic pigments such as titanium oxide, metal foil pigments, and rust-preventive pigments, ultraviolet absorbers such as hindered amines, benzotriazoles, and benzophenones, antioxidants such as hindered phenols, phosphorus, sulfur, and hydrazides, release agents such as stearic acid, palmitic acid, zinc stearate, and calcium stearate, and additives such as leveling agents, rheology control agents, pigment dispersants, anti-cracking agents, and defoamers. The amount of these other components to be added is preferably in the range of 0.01 to 20% by mass based on the total solid content in the resin composition.

The resin composition of the present invention is obtained by uniformly mixing the above components. The resin composition containing the modified phenoxy resin of the present invention, a curing agent, and further various components as necessary can be easily made into a cured product by a method similar to that known in the art. This cured product has an excellent balance of low moisture absorption, dielectric properties, heat resistance, adhesion, etc., and exhibits good cured physical properties. "Cure" here means intentionally curing the resin composition with heat and/or light, etc., and the degree of curing may be controlled depending on the desired physical properties and application. The degree of progress may be completely cured or semi-cured, and is not particularly limited, but the reaction rate of the curing reaction between the epoxy group and the curing agent is usually 5 to 95%.

The resin composition of the present invention can be cured in the same manner as known epoxy resin compositions to obtain a cured product. The same methods as known epoxy resin compositions can be used to obtain a cured product, and methods such as casting, injection, potting, dipping, drip coating, transfer molding, compression molding, etc., or laminating in the form of a resin sheet, resin-coated copper foil, prepreg, etc., and curing under heat and pressure to obtain a laminate are preferably used. The curing temperature is usually in the range of 80 to 300°C, and the curing time is about 10 to 360 minutes. This heating is preferably performed in two stages, with a primary heating at 80 to 180°C for 10 to 90 minutes and a secondary heating at 120 to 200°C for 60 to 150 minutes. In addition, in a compounding system in which the glass transition temperature (Tg) exceeds the temperature of the secondary heating, it is preferable to further perform a tertiary heating at 150 to 280°C for 60 to 120 minutes. By performing such secondary and tertiary heating, poor curing can be reduced. When producing semi-cured resin products such as resin sheets, resin-coated copper foils, and prepregs, the curing reaction of the resin composition is usually allowed to proceed to an extent that the shape can be maintained by heating or the like. If the resin composition contains a solvent, most of the solvent is usually removed by methods such as heating, reducing pressure, and air drying, but 5% by mass or less of the solvent may remain in the semi-cured resin product.

The reinforcing fibers used in the fiber-reinforced plastic made using the resin composition of the present invention are intended to reinforce plastics, such as carbon fibers, aramid fibers, and cellulose fibers, and are not particularly limited. The form of the fibers is also not particularly limited, and includes UD sheets, woven fabrics, tows, chopped fibers, nonwoven fabrics, paper, and the like, in which the fibers are aligned. However, from the viewpoint of impregnation, the thickness of each fiber bundle is 1 mm or less, preferably 0.5 mm or less, and more preferably 0.2 mm or less.
The use of carbon fibers as reinforcing fibers is preferred because it provides a composite material with a good balance of strength and rigidity. The carbon fibers may be either PAN-based or pitch-based, with PAN-based being particularly preferred.

The fiber-reinforced plastic is obtained from the resin composition and reinforcing fibers using a known method. The ratio of reinforcing fibers to resin composition is preferably 5:5 to 8:2 by mass. Regarding the ratio of reinforcing fibers, if the amount of reinforcing fibers is too small, the strength required for the fiber-reinforced material may not be fully satisfied, and if the amount of reinforcing fibers is too large, defects such as voids may occur.

The polymerization conditions for obtaining a fiber-reinforced plastic from the resin composition of the present invention are preferably a polymerization temperature of 120 to 200°C and a polymerization time of 5 to 480 minutes.

The weight average molecular weight (Mw) of the fiber reinforced plastic is 40,000 to 200,000. If it is less than 40,000, the strength of the material may not be ensured. If it exceeds 200,000, the gel content increases, and the moldability may be poor. The Mw of the fiber reinforced plastic can be measured by the gel permeation chromatography method (GPC method) described in the examples.

The laminate obtained using the resin composition of the present invention will now be described. The laminate of the present invention has an insulating layer composed of a cured product such as a prepreg or insulating adhesive sheet using the resin composition of the present invention, as described below.

The prepreg obtained using the resin composition of the present invention will be described. As the sheet-like substrate, woven or nonwoven fabrics of inorganic fibers such as glass, or organic fibers such as polyester, polyamine, polyacrylic, polyimide, Kevlar (registered trademark), cellulose, etc. can be used, but are not limited thereto. The method for producing a prepreg from the resin composition of the present invention and the sheet-like substrate is not particularly limited, and for example, the above-mentioned sheet-like substrate is immersed in a resin varnish in which the viscosity of the above-mentioned resin composition is adjusted with a solvent, and then heated and dried to semi-cure (B-stage) the resin component, and the prepreg can be obtained, for example, by heating and drying at 100 to 200°C for 1 to 40 minutes. Here, the amount of resin in the prepreg is preferably 30 to 80% by mass of resin.

A method for manufacturing a laminate using a prepreg or an insulating adhesive sheet will be described. When forming a laminate using a prepreg, one or more prepregs are laminated, a metal foil is placed on one or both sides to form a laminate, and this laminate is heated and pressed to laminate and integrate it. Here, as the metal foil, a single metal foil, an alloy metal foil, or a composite metal foil such as copper, aluminum, brass, or nickel can be used. The conditions for heating and pressing the laminate may be appropriately adjusted so that the resin composition is cured, but if the pressure is too low, air bubbles may remain inside the obtained laminate, which may deteriorate the electrical properties, so it is desirable to pressurize under conditions that satisfy the moldability. For example, the temperature can be set to 160 to 220°C, the pressure to 49 to 490 N/cm ² (5 to 50 kgf/cm ² ), and the heating time to 40 to 240 minutes.

Furthermore, a multilayer board can be made by using the single-layer laminate obtained in this way as an inner layer material. In this case, first, a circuit is formed on the laminate by an additive method, subtractive method, etc., and the surface of the formed circuit is treated with an acid solution for blackening to obtain an inner layer material. An insulating layer is formed on one or both circuit-forming surfaces of this inner layer material using a prepreg or insulating adhesive sheet, and a conductor layer is formed on the surface of the insulating layer to form a multilayer board.

When forming an insulating layer using an insulating adhesive sheet, an insulating adhesive sheet is placed on the circuit-forming surface of a plurality of inner layer materials to form a laminate. Alternatively, an insulating adhesive sheet is placed between the circuit-forming surface of the inner layer material and a metal foil to form a laminate. Then, this laminate is heated and pressurized to be integrally molded, thereby forming the cured product of the insulating adhesive sheet as an insulating layer and forming a multi-layered inner layer material. Alternatively, the inner layer material and the metal foil as a conductor layer form the cured product of the insulating adhesive sheet as an insulating layer. Here, the metal foil can be the same as that used in the laminate used as the inner layer material.
The hot and press molding can be carried out under the same conditions as those for molding the inner layer material. When forming an insulating layer by applying a resin composition to a laminate, the resin composition is applied to the circuit forming surface of the outermost layer of the inner layer material, preferably to a thickness of 5 to 100 μm, and then heated and dried at 100 to 200° C. for 1 to 90 minutes to form a sheet. It is generally formed by a method called a casting method. It is desirable to form the thickness after drying to 5 to 80 μm. A printed wiring board can be formed by further forming via holes and circuits on the surface of the multilayer laminate formed in this way by an additive method or a subtractive method.
Furthermore, by repeating the above-mentioned process using this printed wiring board as an inner layer material, a multi-layer laminate can be formed.

When forming the insulating layer with prepreg, one or more prepreg sheets are placed on the circuit-forming surface of the inner layer material, and a metal foil is placed on the outside of the prepreg to form a laminate. This laminate is then heated and pressurized to form an integral mold, whereby the cured prepreg is formed as the insulating layer, and the metal foil on the outside is formed as the conductor layer.
Here, the metal foil may be the same as that used in the laminate used as the inner layer material. The hot press molding may be performed under the same conditions as those for molding the inner layer material. The surface of the multilayer laminate thus molded may be further subjected to via hole formation and circuit formation by an additive method or a subtractive method to mold a printed wiring board.
Furthermore, by repeating the above process using this printed wiring board as an inner layer material, a multi-layer board with even more layers can be formed.

The cured product obtained from the resin composition of the present invention and the laminate suitable for use in electrical and electronic circuits have excellent flame retardancy and heat resistance.

The present invention will be described in more detail below based on examples and comparative examples, but the present invention is not limited thereto. Unless otherwise specified, parts means "parts by mass" and % means "% by mass". Analytical and measuring methods are shown below. In addition, the unit of various equivalents is "g/eq.".

(1) Weight average molecular weight (Mw) and number average molecular weight (Mn):
It was obtained by GPC measurement. Specifically, a main body HLC8320GPC (manufactured by Tosoh Corporation) equipped with columns (TSKgel SuperH-H, SuperH2000, SuperHM-H, SuperHM-H, all manufactured by Tosoh Corporation) in series was used, and the column temperature was set to 40 ° C. In addition, tetrahydrofuran (THF) was used as the eluent, the flow rate was set to 1.0 mL / min, and a differential refractive index detector was used as the detector. The measurement sample was dissolved in 10 mL of THF (solid content) and filtered with a 0.45 μm microfilter, and the injection amount was 50 μL. Mw was obtained by conversion from the calibration curve obtained from standard polystyrene (manufactured by Tosoh Corporation, PStQuick A, PStQuick B, PStQuick C). The data was processed using GPC8020 Model II Version 6.00 (manufactured by Tosoh Corporation).

(2) IR (infrared absorption spectrum):
A Fourier transform infrared spectrophotometer (Spectrum One FT-IR Spectrometer 1760X, manufactured by Perkin Elmer Precisly) was used, and sodium chloride was used as a cell. A sample dissolved in chloroform was applied onto the cell, and after drying, the transmittance at wave numbers of 500 to 4000 ^cm was measured.

(3) Epoxy equivalent:
The measurements were carried out in accordance with JIS K7236 and expressed in units of "g/eq.". Specifically, a potentiometric titrator (COM-1600ST, manufactured by Hiranuma Sangyo Co., Ltd.) was used, chloroform was used as the solvent, a tetraethylammonium bromide acetate solution was added, and a 0.1 mol/L perchloric acid-acetic acid solution was used. For the solvent-diluted product (resin varnish), the solid content was calculated from the non-volatile content.

(4) Heat resistance:
The measurement was performed in accordance with the IPC-TM-650 2.4.25.c standard. Specifically, a sample having a thickness of 4 mm and a diameter of 3 mm was measured in a range of 20 to 200° C. at a temperature increase rate of 10° C./min using a differential scanning calorimeter EXSTAR6000 DSC6200 (manufactured by Hitachi High-Tech Science Corporation) for two cycles, and the glass transition temperature was expressed as the midpoint glass transition temperature (Tmg) of the measurement chart obtained by the second scan.

(5) Solvent solubility:
The modified phenoxy resin was dissolved in methyl ethyl ketone (MEK) to prepare a resin varnish having a resin content of 40%. The state after being kept in a thermostatic chamber at 25° C. for 24 hours was judged by visual inspection.
Transparent: ○, Turbid: △, Separation: ×

(6) Adhesion:
A resin varnish was applied to copper foil (Mitsui Mining & Smelting Co., Ltd., 3EC 35#) using a coater (0.4 mm thick) and dried in an oven at 150° C. for 30 minutes. A mild steel plate (Japan Test Panel Co., Ltd., JIS G3141 SPCC-SB, 0.8 mm thick, sandblasted) was placed on the obtained copper foil with modified phenoxy resin and hot pressed at 200° C. and 2.7 MPa for 120 minutes, and the peel strength was measured according to JIS C6481.

The abbreviations used in the examples and comparative examples are as follows:

Ａ２：ビスフェノールＡ型エポキシ樹脂（日鉄ケミカル＆マテリアル株式会社製、ＹＤ－１２８、エポキシ当量１８６、ｍ≒０．０９）

Ａ３：ナフタレン型エポキシ樹脂（ＤＩＣ株式会社製、エピクロンＨＰ４０３２Ｄ、エポキシ当量１４２、ｍ≒０．０１）

Ａ４：ベンゼン型エポキシ樹脂（日鉄ケミカル＆マテリアル株式会社製、ＹＤＣ－１３１２、エポキシ当量１７５、ｍ≒０．０５）

ここで、ｍは式（４）におけるｍと同様の意味を有する。 [Bifunctional epoxy resin]
A1: Tetramethylbiphenol type epoxy resin (manufactured by Mitsubishi Chemical Corporation, YX4000, epoxy equivalent 186, m≒0.05)

A2: Bisphenol A type epoxy resin (manufactured by Nippon Steel Chemical & Material Co., Ltd., YD-128, epoxy equivalent 186, m≒0.09)

A3: Naphthalene type epoxy resin (DIC Corporation, Epicron HP4032D, epoxy equivalent 142, m≒0.01)

A4: Benzene type epoxy resin (manufactured by Nippon Steel Chemical & Material Co., Ltd., YDC-1312, epoxy equivalent 175, m≒0.05)

Here, m has the same meaning as m in formula (4).

Ｂ２：合成例２で得た１，１－ビス（４－（２－キノリンカルボキシフェニル））－３，３，５－トリメチルシクロヘキサン（活性エステル基当量３１０）

Ｂ３：合成例３で得た１，１－ビス（４－アセトキシフェニル）－３，３，５－トリメチルシクロヘキサン（活性エステル基当量１９７）

[Diester compounds]
B1: 2-furancarboxylic acid, 4,4'-(3,3,5-trimethylcyclohexylidene)-di-4,1-phenylene ester (Honshu Chemical Industry Co., Ltd., BH-1, active ester group equivalent: 249)

B2: 1,1-bis(4-(2-quinolinecarboxyphenyl))-3,3,5-trimethylcyclohexane (active ester group equivalent: 310) obtained in Synthesis Example 2

B3: 1,1-bis(4-acetoxyphenyl)-3,3,5-trimethylcyclohexane (active ester group equivalent: 197) obtained in Synthesis Example 3

[Bifunctional phenol compound]
C1: Bisphenol A (manufactured by Nippon Steel Chemical & Material Co., Ltd., hydroxyl equivalent: 114)
C2: 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (Honshu Chemical Industry Co., Ltd., BiSP-HTG, hydroxyl equivalent: 155)

[catalyst]
D1: 4-Dimethylaminopyridine (Tokyo Chemical Industry Co., Ltd.)
D2: 2-ethyl-4-methylimidazole (Curesol 2E4MZ, manufactured by Shikoku Chemical Industry Co., Ltd.)

[Solvents]
S1: Cyclohexanone S2: Methyl ethyl ketone (MEK)

[Acid anhydride]
E1: Thiophene-2-carboxylic anhydride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)
E2: Acetic anhydride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)
E3: 2-quinolinecarboxylic anhydride obtained in Synthesis Example 1

[Curing agent]
H1: Phenol novolak resin (manufactured by Aica Kogyo Co., Ltd., Shounol BRG-557, hydroxyl equivalent: 105)
H2: 2-ethyl-4-methylimidazole (Curesol 2E4MZ, manufactured by Shikoku Chemical Industry Co., Ltd.)

Synthesis Example 1
A glass reaction vessel equipped with a stirrer, a thermometer, a nitrogen gas introduction device, a cooling tube, and a dropping device was charged with 195 parts of sodium quinaldate (manufactured by Tokyo Chemical Industry Co., Ltd.), 192 parts of quinaldoyl chloride (manufactured by Sigma-Aldrich Co., Ltd.), and 300 parts of nitroethane (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) at room temperature, and the mixture was heated to 110°C while stirring under nitrogen gas flow, and reacted for 3 hours. Thereafter, the mixture was dried under reduced pressure at 120°C and 1.3 kPa (10 torr) for 2 hours, to obtain 292 parts of 2-quinolinecarboxylic anhydride (E3).

Synthesis Example 2
In a glass reaction vessel equipped with a stirrer, a thermometer, a nitrogen gas introduction device, a cooling tube, and a dropping device, 100 parts of C2, 106 parts of E3, 102 parts of pyridine, and 100 parts of toluene were charged at room temperature, and the mixture was heated to 60°C while stirring under nitrogen gas flow, and reacted for 2 hours. Thereafter, the mixture was dried under reduced pressure at 115°C and 1.3 kPa (10 torr) for 2 hours, and 200 parts of 1,1-bis(4-(2-quinolinecarboxyphenyl))-3,3,5-trimethylcyclohexane (B2) was obtained.

Synthesis Example 3
A glass reaction vessel equipped with a stirrer, a thermometer, a nitrogen gas introduction device, a cooling tube, and a dropping device was charged with 100 parts of C2, 135 parts of E2, and 102 parts of pyridine at room temperature, and the mixture was heated to 60°C while being stirred under nitrogen gas flow, and reacted for 2 hours. Thereafter, the mixture was dried under reduced pressure at 115°C and 1.3 kPa (10 torr) for 2 hours, to obtain 127 parts of 1,1-bis(4-acetoxyphenyl)-3,3,5-trimethylcyclohexane (B3).

Example 1
A glass reaction vessel equipped with a stirrer, a thermometer, a nitrogen gas introduction device, a cooling tube, and a dropping device was charged with 100 parts of A1, 121 parts of B1, and 55 parts of S1 as a reaction solvent at room temperature, and the temperature was raised to 130 ° C. while stirring with nitrogen gas flowing, and 0.1 parts of D1 were added as a catalyst, and the temperature was raised to 145 ° C. and the reaction was carried out at the same temperature for 7 hours. 55 parts of S1 and 221 parts of S2 were used as dilution solvents to dilute and mix, and a phenoxy resin varnish (R1) with a non-volatile content of 40% was obtained. Charts of the GPC and IR measurement results of the obtained phenoxy resin varnish (R1) are shown in Figures 1 and 2, respectively.

Examples 2 to 9, Comparative Examples 1 to 2
A phenoxy resin varnish was obtained by the same procedure as in Example 1, according to the amount (parts) of each raw material shown in Table 1. The "molar ratio" in the table indicates the molar ratio (equivalent ratio) of the acyl group of the diester compound and the hydroxyl group of the bifunctional phenol compound to the epoxy group of the bifunctional epoxy resin.

Example 10
100 parts (40 parts in terms of solid content) of the phenoxy resin varnish (HR2) obtained in Comparative Example 2 and 600 parts of S1 were mixed, and the temperature was raised to 100°C. Then, 5 parts of E1 (0.3 moles per mole of alcoholic hydroxyl group equivalent of the phenoxy resin) were added and reacted for 4 hours. The obtained resin varnish was added to methanol, and the precipitated insoluble matter was filtered off. The filtrate was dried in a vacuum dryer at 150°C and 0.4 kPa (3 torr) for 1 hour to obtain a modified phenoxy resin. 21 parts of S1 and 43 parts of S2 were added to the obtained modified phenoxy resin and dissolved uniformly to obtain a phenoxy resin varnish (R10) with a non-volatile content of 40%.

Example 11
The same procedure as in Example 10 was carried out except that E1 was 18 parts (1.0 mole per mole of alcoholic hydroxyl group equivalent of the phenoxy resin), S1 of the dilution solvent was 27 parts, and S2 was 54 parts, to obtain a phenoxy resin varnish (R11).

The phenoxy resin varnishes R1 to R11 and HR1 to HR2 obtained in Examples 1 to 11 and Comparative Examples 1 and 2 were applied to an iron plate so that the film thickness after drying would be 150 μm, and then dried at 180° C. for 1 hour using a dryer to obtain a resin film.
The epoxy equivalent and Mw of the phenoxy resin varnish, and the heat resistance, solvent solubility, and adhesion of the resin film were measured. The results are shown in Table 2. In the table, the "acylation rate" indicates the content (mol%) of acyl groups in the total Z. The examples using phenoxy resin varnishes HR1 to HR2 are comparative examples.

Example 12, Example 13, and Comparative Example 3
Each of the phenoxy resin varnishes (R1, R8, HR1) obtained in Example 1, Example 8, and Comparative Example 1 was mixed with 12 parts (solid content value: 30 parts of varnish), 2 parts of epoxy resin A2, 2.5 parts of hardener H1 in 50% MEK solution, and 0.6 parts of H2 in 20% MEK solution to obtain a resin composition. These were then applied to an iron plate so that the film thickness after drying was 150 μm, and dried at 200° C. for 2 hours using a dryer to obtain a polymer film-like hardened product, after which the heat resistance was measured. The results are shown in Table 3. The values in parentheses in the table indicate solid content values.

Table 2 shows that the modified phenoxy resin of the present invention has excellent heat resistance. Table 3 shows that the cured product made from the modified phenoxy resin composition of the present invention also has excellent heat resistance.

The modified phenoxy resin and resin composition of the present invention are applicable to various fields such as adhesives, paints, civil engineering building materials, insulating materials for electric and electronic parts, and are particularly useful in the electric and electronic fields as insulating casting, lamination materials, sealing materials, etc. The phenoxy resin of the present invention and a resin composition containing the same can be suitably used for multilayer printed wiring boards, laminates for electric and electronic circuits such as capacitors, adhesives such as film adhesives and liquid adhesives, semiconductor sealing materials, underfill materials, interchip fill materials for 3D-LSI, insulating sheets, prepregs, heat dissipation substrates, etc.
The cured products and fiber-reinforced plastics using the modified phenoxy resin composition of the present invention are applicable to various fields such as aerospace applications and general industrial applications, and are particularly useful as automotive components that require mass production, as well as IC trays and housings for notebook computers, tablets, and smartphones.

Claims (14)

A modified phenoxy resin represented by the following general formula (1) and having a weight average molecular weight of 5,000 to 200,000:

Here, X is a divalent group. Y is independently a hydrogen atom, an unsaturated heterocyclic ring-containing acyl group having 5 to 20 carbon atoms, or a glycidyl group. Z is independently a hydrogen atom or an unsaturated heterocyclic ring-containing acyl group having 5 to 20 carbon atoms, and 5 mol % or more of the acyl group is the above-mentioned. n is the number of repetitions, and the average value is 15 or more and 500 or less. The modified phenoxy resin according to claim 1, wherein the unsaturated heterocyclic ring-containing acyl group having 5 to 20 carbon atoms is any one of the unsaturated heterocyclic ring-containing acyl groups represented by the following formulas (2a) to (2f):

Here, R ¹ to R ⁶ are independently a hydrocarbon group having 1 to 6 carbon atoms, n1 is an integer from 0 to 3, n2 is an integer from 0 to 5, n3 is an integer from 0 to 5, n4 is an integer from 0 to 4, n5 is an integer from 0 to 6, and n6 is an integer from 0 to 8. W is an oxygen atom or a sulfur atom. The modified phenoxy resin according to claim 1, wherein the Z comprises any one of the unsaturated heterocycle-containing acyl groups represented by the following formulas (3a) to (3c):

A resin composition comprising the modified phenoxy resin according to claim 1 and a curing agent. The resin composition according to claim 4, wherein the curing agent is at least one selected from the group consisting of acrylic ester resins, melamine resins, urea resins, phenolic resins, acid anhydride compounds, amine compounds, imidazole compounds, amide compounds, cationic polymerization initiators, organic phosphines, phosphonium salts, tetraphenylboron salts, hydrazide compounds, boron halide amine complexes, polymercaptan compounds, isocyanate compounds, polyisocyanate compounds, blocked isocyanate compounds, and active ester compounds. The resin composition according to claim 4, which contains 0.1 to 100 parts by mass of the hardener as solid content per 100 parts by mass of the solid content of the modified phenoxy resin. A resin composition comprising the modified phenoxy resin according to claim 1, an epoxy resin and a curing agent, the mass ratio of the solid content of the modified phenoxy resin to the epoxy resin being 99/1 to 1/99. The resin composition according to claim 7, which contains 0.1 to 100 parts by mass of the hardener as solid content per 100 parts by mass of the total solid content of the modified phenoxy resin and the epoxy resin. The resin composition according to claim 8, wherein the curing agent is at least one selected from the group consisting of acrylic ester resins, melamine resins, urea resins, phenolic resins, acid anhydride compounds, amine compounds, imidazole compounds, amide compounds, cationic polymerization initiators, organic phosphines, phosphonium salts, tetraphenylboron salts, hydrazide compounds, boron halide amine complexes, polymercaptan compounds, isocyanate compounds, polyisocyanate compounds, blocked isocyanate compounds, cyanate ester compounds, and active ester compounds. A cured product obtained by curing the resin composition according to any one of claims 4 to 9. A fiber-reinforced plastic made using the resin composition according to any one of claims 4 to 9. A laminate having an insulating layer made of a cured product of the resin composition according to any one of claims 4 to 9. A method for producing the modified phenoxy resin according to claim 1, comprising reacting a bifunctional epoxy resin represented by the following general formula (4) with a compound represented by the following general formula (5).

Here, ^X1 and ^X2 are divalent groups. G is a glycidyl group. Q is an unsaturated heterocycle-containing acyl group having 5 to 20 carbon atoms or a hydrogen atom, and 5 mol% or more of the acyl group is the above. m is the number of repetitions, the average value of which is 0 to 6. The compound represented by general formula (5) may be a mixture of two or more selected from a compound in which both Qs are the above acyl group, a compound in which one Q is the above acyl group, and a compound in which both Qs are hydrogen atoms. A method for producing the modified phenoxy resin according to claim 1, comprising reacting 0.05 mol or more and 2.0 mol or less of an acid anhydride represented by the following general formula (7) with 1 mol of an alcoholic hydroxyl group equivalent of the phenoxy resin represented by the following general formula (6):

Here, X and n are defined as in formula (1), L is independently a hydrogen atom or a glycidyl group, and T is an unsaturated heterocyclic ring-containing acyl group having 5 to 20 carbon atoms.

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