Phenoxy resin, resin composition, cured product, laminate for electrical and electronic circuits, and method for producing phenoxy resin

Abstract

The present invention provides: a phenoxy resin which exhibits excellent heat resistance, dielectric characteristics and folding resistance; a resin composition which contains this phenoxy resin and a curing agent; a cured product of this resin composition, said cured product exhibiting excellent heat resistance, dielectric characteristics and folding resistance; and a laminate for electric / electronic circuits.　This phenoxy resin is represented by formula (1), and has a weight average molecular weight of from 10,000 to 200,000. In the formula, X represents a divalent group containing a dioxy group represented by formula (2) or formula (3); Y represents a hydrogen atom, an acyl group or a glycidyl group; and Z represents a hydrogen atom or an acyl group, with 5% by mole or more thereof being an acyl group.

Description

[Technical Field]

[0001] The present invention relates to a phenoxy resin having excellent heat resistance, dielectric properties, and folding resistance, a resin composition containing the phenoxy resin and a curing agent, a cured product thereof having excellent heat resistance, dielectric properties, and folding resistance, and a laminate for electric and electronic circuits made of the resin composition. [Background technology]

[0002] Epoxy resins are widely used in fields such as paints, civil engineering, adhesives, and electrical materials due to their excellent heat resistance, adhesive properties, chemical resistance, water resistance, mechanical strength, and electrical properties. Furthermore, film-forming properties can be imparted by increasing their molecular weight through various methods. Such high-molecular-weight epoxy resins are called phenoxy resins. In particular, bisphenol A-type phenoxy resins are primarily used as base resins for paint varnishes and film molding, and are added to epoxy resin varnishes to adjust flowability and improve toughness and adhesive properties when cured. Furthermore, those containing phosphorus or bromine atoms in their skeletons are used as flame retardants incorporated into epoxy resin compositions and thermoplastic resins.

[0003] Phenoxy resins used in electrical materials such as laminates for electric and electronic circuits require heat resistance, dielectric properties, and folding resistance.

[0004] In response to such demands, a method has been proposed for improving heat resistance by increasing the bulkiness of molecular chains and suppressing micro-Brownian motion. Patent Document 1 discloses a phenoxy resin with excellent heat resistance, which is produced by reacting a bulky bisphenol compound with a difunctional epoxy resin. However, although this method can impart excellent heat resistance to the phenoxy resin, it has the problem of not improving its dielectric properties.

[0005] On the other hand, a method has been proposed to improve the dielectric properties by converting the hydroxyl groups present in the side chains of phenoxy resins into esters using acetyl or benzoyl groups. In Patent Document 2, the present inventors confirmed that a phenoxy resin obtained by reacting a bifunctional epoxy resin with a diester compound has excellent dielectric properties, but has the problem of poor heat resistance. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-231428 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-089165 Summary of the Invention

[0007] The present invention aims to provide a phenoxy resin having excellent heat resistance, dielectric properties, and folding resistance, and to provide a cured product having excellent heat resistance, dielectric properties, and folding resistance by curing a resin composition containing the phenoxy resin.

[0008] In order to solve the above problems, the present inventors have conducted extensive research on phenoxy resins and have found that a phenoxy resin having a specific structure has excellent heat resistance, dielectric properties, and folding resistance, and further found that a cured product obtained by curing a resin composition containing such a phenoxy resin has excellent heat resistance, dielectric properties, and folding resistance, thereby completing the present invention.

[0009] That is, the present invention relates to a phenoxy resin represented by the following formula (1) and having a weight average molecular weight of 10,000 to 200,000. [ka] In the formula, X is independently a divalent group containing a dioxy group represented by the following formula (2) or formula (3), and each Y is independently a hydrogen atom, an acyl group having a hydrocarbon group of 1 to 20 carbon atoms, or a glycidyl group. Z is an acyl group having a hydrocarbon group of 1 to 20 carbon atoms or a hydrogen atom, and 5 mol % or more of the acyl group is the above. n is the average number of repetitions and is 15 to 500.

[0010] [ka] In formula (2) and formula (3), each R is independently a group selected from the group consisting of an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 13 carbon atoms, an aryloxy group having 6 to 12 carbon atoms, an aralkyloxy group having 7 to 13 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, and an alkynyl group having 2 to 12 carbon atoms; i is an integer of 0 to 4; and j is an integer of 0 to 6.

[0011] The present invention also provides a resin composition containing the above-mentioned phenoxy resin and a curing agent. The resin composition preferably contains 0.1 to 100 parts by mass of the curing agent as solid content per 100 parts by mass of the phenoxy resin solid content.

[0012] The resin composition contains the phenoxy resin, an epoxy resin, and a curing agent, and the mass ratio of the solid content of the phenoxy resin to the solid content of the epoxy resin can be 99 / 1 to 1 / 99. This resin composition preferably contains 0.1 to 100 parts by mass of the curing agent as solid content per 100 parts by mass of the total solid content of the phenoxy resin and the epoxy resin.

[0013] The curing agent to be blended in the resin composition 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, polyisocyanate compounds, blocked isocyanate compounds, and active ester curing agents.

[0014] The present invention also relates to a cured product obtained by curing the above-mentioned resin composition. Furthermore, the present invention relates to a laminate for electric / electronic circuits, which is made using the above resin composition.

[0015] The present invention also provides a method for producing the above-mentioned phenoxy resin, which comprises reacting a bifunctional epoxy resin represented by the following formula (7) with a compound represented by the following formula (8). [ka] In the formula, X 1 are independently divalent groups containing a dioxy group represented by the above formula (2) or formula (3), and X in formula (7) and formula (8) 1 These include dioxy groups represented by formula (2) and formula (3) as a whole. Z 1 is an acyl group having a hydrocarbon group of 1 to 20 carbon atoms or a hydrogen atom, and 5 mol % or more of the acyl group is the above. 1 The compound may be a mixture of two or more compounds selected from compounds in which both of the above groups are acyl groups, compounds in which one of the above groups is an acyl group, and compounds in which both of the above groups are hydrogen atoms. m is the average number of repetitions and is between 0 and 6.

[0016] Furthermore, the present invention provides a method for producing the above-mentioned phenoxy resin, characterized by reacting 0.05 to 2.0 moles of acyl groups of an acylating agent with 1 mole of alcoholic hydroxyl groups of the phenoxy resin represented by the following formula (12): [ka] In the formula, X 2 are independently divalent groups containing a dioxy group represented by the above formula (2) and formula (3), and Y 2 are each independently a hydrogen atom or a glycidyl group, and n is the average number of repetitions and is 15 to 500.

[0017] According to the present invention, a phenoxy resin having excellent heat resistance, dielectric properties, and folding resistance can be provided. Furthermore, a resin composition using this phenoxy resin can provide a cured product having excellent heat resistance, dielectric properties, and folding resistance. DETAILED DESCRIPTION OF THE INVENTION

[0018] The phenoxy resin of the present invention is a phenoxy resin represented by the above formula (1) having a weight average molecular weight (Mw) of 10,000 to 200,000, and has a benzene skeleton represented by the above formula (2) and a naphthalene skeleton represented by the formula (3), and further has a structure in which some or all of the hydrogen atoms in the hydroxyl groups are substituted with acyl groups (Z). Here, if the Mw is less than 10,000, film-forming properties and mechanical properties (particularly folding endurance) may be reduced, which is undesirable. If the Mw is more than 200,000, compatibility may be reduced, making the resin difficult to handle, which is undesirable. The Mw is preferably 15,000 to 160,000, more preferably 20,000 to 120,000, and even more preferably 20,000 to 120,000. The Mw of the phenoxy resin can be measured by gel permeation chromatography (GPC) as described in the examples.

[0019] The phenoxy resin of the present invention has a structure in which the hydrogen atoms in the hydroxyl groups are substituted with acyl groups, which results in low polarity and excellent dielectric properties, as well as low moisture absorption and good solvent solubility.

[0020] The phenoxy resin of the present invention can be advantageously obtained by the manufacturing method of the present invention. In this specification, the phenoxy resin obtained by the manufacturing method of the present invention is sometimes referred to as the "phenoxy resin of the present invention," the cured product obtained by curing the resin composition of the present invention is sometimes referred to as the "cured product of the present invention," and the manufacturing method of the phenoxy resin of the present invention is sometimes referred to as the "manufacturing method of the present invention."

[0021] In the formula (1), X is independently a divalent group containing a dioxy group represented by the formula (2) or (3). The groups represented by the formula (2) and the formula (3) are called dioxy groups because they have oxygen atoms at both ends. The divalent group may be either the formula (2), the formula (3), or a divalent group other than these, but as a whole, it contains the dioxy group represented by the formula (2) or the formula (3). The molar ratio of the dioxy groups represented by the formula (2) and the formula (3) (formula 2 / formula 3) is preferably 1 / 9 to 9 / 1, more preferably 2 / 8 to 8 / 2, even more preferably 3 / 7 to 7 / 3, and particularly preferably 4 / 6 to 6 / 4. Furthermore, the dioxy groups represented by the formula (2) and the formula (3) are preferably 1 mol% or more, more preferably 10 mol% or more, even more preferably 30 mol% or more, and particularly preferably 50 mol% or more, based on the total number of moles of X. Outside this range, heat resistance and folding endurance may be deteriorated. Examples of divalent groups other than the dioxy group include divalent groups represented by -O-Ar-O-, where Ar is a residue in which two hydroxyl groups have been removed from a bifunctional phenol compound that may be used in combination as described below.

[0022] In formula (2) and formula (3), each R is independently a group arbitrarily selected from an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 13 carbon atoms, an aryloxy group having 6 to 12 carbon atoms, an aralkyloxy group having 7 to 13 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, and an alkynyl group having 2 to 12 carbon atoms.

[0023] The alkyl group having 1 to 12 carbon atoms may be linear, branched, or cyclic, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a t-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, a t-pentyl group, a cyclopentyl group, an n-hexyl group, an isohexyl group, a cyclohexyl group, an n-heptyl group, a cycloheptyl group, a methylcyclohexyl group, an n-octyl group, a cyclooctyl group, an n-nonyl group, a 3,3,5-trimethylcyclohexyl group, an n-decyl group, a cyclodecyl group, an n-undecyl group, an n-dodecyl group, a cyclododecyl group, a benzyl group, a methylbenzyl group, a dimethylbenzyl group, a trimethylbenzyl group, a naphthylmethyl group, a phenethyl group, and a 2-phenylisopropyl group.

[0024] The alkoxy group having 1 to 12 carbon atoms may be linear, branched, or cyclic, and examples thereof include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, a t-butoxy group, an n-pentoxy group, an isopentoxy group, a neopentoxy group, a t-pentoxy group, a cyclopentoxy group, an n-hexyloxy group, an isohexyloxy group, a cyclohexyloxy group, an n-heptoxy group, a cycloheptoxy group, a methylcyclohexyloxy group, and the like. Examples of the alkoxy group include, but are not limited to, an oxy group, an n-octyloxy group, a cyclooctyloxy group, an n-nonyloxy group, a 3,3,5-trimethylcyclohexyloxy group, an n-decyloxy group, a cyclodecyloxy group, an n-undecyloxy group, an n-dodecyloxy group, a cyclododecyloxy group, a benzyloxy group, a methylbenzyloxy group, a dimethylbenzyloxy group, a trimethylbenzyloxy group, a naphthylmethoxy group, a phenethyloxy group, and a 2-phenylisopropoxy group.

[0025] Examples of aryl groups having 6 to 12 carbon atoms include, but are not limited to, a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, an ethylphenyl group, a styryl group, a xylyl group, an n-propylphenyl group, an isopropylphenyl group, a mesityl group, an ethynylphenyl group, a naphthyl group, and a vinylnaphthyl group.

[0026] Examples of aralkyl groups having 7 to 13 carbon atoms include, but are not limited to, a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, an ethylphenyl group, a styryl group, a xylyl group, an n-propylphenyl group, an isopropylphenyl group, a mesityl group, an ethynylphenyl group, a naphthyl group, and a vinylnaphthyl group.

[0027] Examples of aryloxy groups having 6 to 12 carbon atoms include, but are not limited to, a phenoxy group, an o-tolyloxy group, an m-tolyloxy group, a p-tolyloxy group, an ethylphenoxy group, a styryloxy group, a xylyloxy group, an n-propylphenoxy group, an isopropylphenoxy group, a mesityloxy group, an ethynylphenoxy group, a naphthyloxy group, and a vinylnaphthyloxy group.

[0028] Examples of aralkyloxy groups having 7 to 13 carbon atoms include, but are not limited to, benzyloxy, methylbenzyloxy, dimethylbenzyloxy, trimethylbenzyloxy, phenethyloxy, 1-phenylethyloxy, 2-phenylisopropyloxy, and naphthylmethyloxy groups.

[0029] Examples of alkenyl groups having 2 to 12 carbon atoms include, but are not limited to, vinyl, 1-propenyl, 2-propenyl, 1-methylvinyl, 1-butenyl, 2-butenyl, 3-butenyl, 1,3-butadienyl, cyclohexenyl, cyclohexadienyl, cinnamyl, and naphthylvinyl groups.

[0030] Examples of the alkynyl group having 2 to 12 carbon atoms include an ethynyl group, a 1-propynyl group, a 2-propynyl group, a 1-butynyl group, a 2-butynyl group, a 3-butynyl group, and a 1,3-butynyl group. Grandpa Examples of ethynyl groups include, but are not limited to, phenylethynyl groups, phenylethynyl groups, naphthylethynyl groups, and the like.

[0031] Among the above, R is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and more preferably a hydrogen atom or a methyl group. This is because a large substituent may reduce heat resistance. R being a hydrogen atom means that i or j is 0. i is an integer of 0 to 4, and j is an integer of 0 to 6, but preferably i is an integer of 0 to 2, and j is an integer of 0 to 2.

[0032] In formula (1), each Y is independently a hydrogen atom, an acyl group having a hydrocarbon group of 1 to 20 carbon atoms, or a glycidyl group. When Y is a hydrogen atom, a hydroxyl group is provided at the terminal, when Y is an acyl group, an ester group is provided at the terminal, and when Y is a glycidyl group, an epoxy group is provided at the terminal; therefore, it is advisable to control the ratio depending on the application. The hydrocarbon group having 1 to 20 carbon atoms is preferably an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 13 carbon atoms, and examples thereof include the groups exemplified above. Among these, an acyl group having a hydrocarbon group having 1 to 7 carbon atoms is more preferred, with an acetyl group, a propanoyl group, a butanoyl group, a benzoyl group, and a methylbenzoyl group being even more preferred, and an acetyl group and a benzoyl group being particularly preferred. An acetyl group is understood to be an acyl group having a hydrocarbon group with 1 carbon atom.

[0033] In formula (1), Z is an acyl group having a hydrocarbon group of 1 to 20 carbon atoms or a hydrogen atom. At least 5 mol % of Z are acyl groups, and the remainder are hydrogen atoms. At least 10 mol %, preferably at least 50 mol %, and more preferably at least 70 mol % of Z are acyl groups. The upper limit is preferably 100 mol %, but substantially 95 mol % is sufficient. The acyl group having a hydrocarbon group of 1 to 20 carbon atoms is the same as that exemplified for Y above, and the preferred acyl groups are also the same. When all Z's (100 mol%) are acyl groups, the phenoxy resin of the present invention does not contain secondary hydroxyl groups, and the dielectric properties and moisture resistance can be further improved. On the other hand, when fine-tuning the adhesion to metals, for example, by leaving some of the Z's as hydrogen atoms, it is possible to intentionally allow an appropriate amount of secondary hydroxyl groups to be present in the phenoxy resin of the present invention, as long as this does not significantly affect other physical properties such as moisture resistance.

[0034] In formula (1), n ​​is the number of repeating units 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, more preferably from 20 to 300. The number n can be calculated from the number average molecular weight (Mn) obtained by GPC.

[0035] The epoxy equivalent of the phenoxy resin of the present invention is not particularly limited, but is preferably in the range of 2,000 to 50,000 g / eq. Within this range, the phenoxy resin of the present invention itself can participate in the curing reaction and be incorporated into a crosslinked structure.

[0036] The phenoxy resin of the present invention has some or all of its secondary hydroxyl groups acylated, and can be obtained by various methods. Preferred production methods include, for example, the following production method. (A): A production method in which a bifunctional epoxy resin represented by the above formula (7) is reacted with a diester compound and / or a bifunctional phenol compound represented by the above formula (8). 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 (12) (sometimes referred to as phenoxy resin (a) to distinguish it from the 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 obtained by the production methods (A) and (B) are the phenoxy resins of the present invention and are represented by the same formula (1).

[0037] The production method (A) is a method in which a bifunctional epoxy resin represented by formula (7) is reacted with a compound represented by formula (8). In the above formula (7), G is a glycyl group, m is the number of repetitions, and the average value is 0 or more and 6 or less. In equation (8), Z 1 At least 5 mol % of the groups are acyl groups having a hydrocarbon group having 1 to 20 carbon atoms, and the remainder are hydrogen atoms. 1 and Z may be a mixture of two or more compounds selected from compounds in which both of Z are acyl groups, compounds in which one is an acyl group and the other is a hydrogen atom, and compounds in which both are hydrogen atoms. 1 When both are acyl groups, it becomes a diester, and when both are hydrogen atoms, it becomes a diphenol. The compound represented by formula (8) is called a diester compound. Diester compounds are classified into 1 It is preferable that both of the above are acyl groups or that the main component (50% or more) of the compound (mixture) is such a compound.

[0038] X in Equation (7) and Equation (8) 1 is selected to give X in equation (1). Therefore, X in equations (7) and (8) 1 contains a dioxy group represented by formula (2) and / or formula (3), and the formulas (7) and (8) as a whole contain dioxy groups represented by formula (2) and formula (3). For example, X in one of formulas (7) and (8) 1 one of X in formula (7) or (8) contains a dioxy group represented by formula (2) and the other contains a dioxy group represented by formula (3); 1 Only one of the two may contain a dioxy group represented by formula (2) and formula (3), and the other may not, but the former is preferred. The phenoxy resin of the present invention necessarily contains the dioxy groups represented by formula (2) and formula (3). As long as this requirement is met, the dioxy groups of formula (2) and formula (3) can be easily obtained by the reaction of the difunctional epoxy resin and / or the compound represented by formula (8) as the raw material. of It may be contained in either of these, and the proportion is not limited. In addition, X in the above formula (7) or formula (8) 1 When the chemical structure of formula (2) and formula (3) is not included, X 1 Another divalent group can be introduced into

[0039] The bifunctional epoxy resin used in the production method (A) of the present invention is an epoxy resin represented by the above formula (7), and examples thereof include an epoxy resin obtained by reacting a bifunctional phenol compound represented by the following formula (14) with epihalohydrin in the presence of an alkali metal compound. Examples of epihalohydrins 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.

[0040] In the reaction of a bifunctional phenol compound with epihalohydrin to obtain the starting epoxy resin, an alkali metal compound is used in an amount of 0.80 to 1.20 times by mole, preferably 0.85 to 1.05 times by mole, relative to the functional groups in the bifunctional phenol compound. Less than this amount is undesirable because the amount of residual hydrolyzable chlorine increases. The alkali metal compound is used in the form of an aqueous solution, an alcohol solution, or a solid.

[0041] In the epoxidation reaction, an excess amount of epihalohydrin is used relative to the bifunctional phenol compound. Typically, 1.5 to 15 moles of epihalohydrin are used per mole of functional groups in the bifunctional phenol compound, preferably 2 to 10 moles, and more preferably 5 to 8 moles. If the amount is greater than this, production efficiency decreases, and if it is less than this, the amount of high molecular weight epoxy resin produced increases, making it unsuitable as a raw material for phenoxy resin.

[0042] The epoxidation reaction is usually carried out at a temperature of 120°C or lower. If the reaction temperature is high, the amount of so-called difficultly hydrolyzable chlorine increases, making it difficult to achieve high purification. The temperature is preferably 100°C or lower, and more preferably 85°C or lower.

[0043] [ka] In equation (14), X 1 is X in the above formula (7) or (8). 1 is the same as:

[0044] When a bifunctional phenol compound represented by the above formula (14) is reacted with epihalohydrin, m usually becomes 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 represented by the above formula (14) can be allylated and then epoxidized by oxidizing the olefin moiety.

[0045] The diester compound used in the production method (A) of the present invention can be obtained, for example, by acylation of a bifunctional phenol compound represented by the above formula (14) through a condensation reaction with an acid anhydride of an organic acid, a halide of an organic acid, or an organic acid.

[0046] By using an epoxy resin in which m in formula (7) is 0 as the raw material, the phenoxy resin of the present invention will not contain secondary hydroxyl groups, and dielectric properties and moisture resistance can be further improved. Furthermore, when fine-tuning adhesion to metals, for example, by using an epoxy resin with an appropriate m number, it is possible to intentionally allow an appropriate amount of secondary hydroxyl groups to be present in the phenoxy resin of the present invention, within a range that does not significantly affect other physical properties such as moisture resistance.

[0047] In the bifunctional epoxy resin or diester compound used in the production method (A), the chemical structure represented by the above formula (2) and formula (3) is X in the above formula (7) and formula (8). 1 The content of the chemical structures represented by formulas (2) and (3) is preferably 1 to 100 mol % relative to the total number of moles. From the viewpoint of fully exhibiting the folding endurance and dielectric properties attributable to the chemical structures represented by formulas (2) and (3), the content of the chemical structures represented by formulas (2) and (3) is more preferably 10 mol % or more, even more preferably 30 mol % or more, and particularly preferably 50 mol % or more.

[0048] The amount of the bifunctional epoxy resin and diester compound used is preferably 0.8 to 1.0 equivalents of ester group per equivalent of epoxy group. This equivalent ratio is preferred because it facilitates the promotion of high molecular weight polymerization with epoxy groups at the molecular terminals. It is also possible to replace a portion of the diester compound with a bifunctional phenol compound represented by the above formula (14). As mentioned above, this allows the presence of an appropriate amount of secondary hydroxyl groups in the phenoxy resin of the present invention, allowing for fine adjustment of physical properties. In the production method (A), a polymerization reaction and an ester exchange reaction occur, and the Mw increases to produce a phenoxy resin, and the water content of the phenoxy resin increases. acid Some of the groups are esterified.

[0049] In the production method (A), a catalyst may be used. The catalyst may be any compound having catalytic activity that promotes the reaction between the epoxy group and the ester group. 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.

[0050] Examples of tertiary amines include, but are not limited to, triethylamine, tri-n-propylamine, tri-n-butylamine, triethanolamine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and the like.

[0051] 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 N,N-dimethylaminopyridine (DMAP).

[0052] 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.

[0053] Examples of the 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 hydroxide, and tetramethylphosphonium iodide; Examples of the phosphonium salts include, but are not limited to, 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.

[0054] 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.

[0055] Among the catalysts listed above, 4-(dimethylamino)pyridine, 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-(dimethylamino)pyridine, 1,8-diazabicyclo[5,4,0]undecene-7, 1,5-diazabicyclo[4,3,0]nonene-5, and 2-ethyl-4-methylimidazole are particularly preferred.

[0056] The amount of catalyst used is usually 0.001 to 1 mass% of the reaction solid content, but when these compounds are used as catalysts, these catalysts remain as residues in the resulting phenoxy resin, which may deteriorate the insulating properties of the printed wiring board or shorten the pot life of the composition. Therefore, the nitrogen content in the phenoxy resin is preferably 0.5 mass% or less, more preferably 0.3 mass% or less. The phosphorus content in the phenoxy resin is preferably 0.5 mass% or less, more preferably 0.3 mass% or less. below is more preferred.

[0057] In the production method (A), a reaction solvent may be used. Any solvent that dissolves the 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.

[0058] Examples of aromatic solvents include benzene, toluene, and xylene.

[0059] Examples of ketone solvents include acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, 2-heptanone, 4-heptanone, 2-octanone, cyclohexanone, acetylacetone, dioxane, diisobutyl ketone, isophorone, methylcyclohexanone, and acetophenone.

[0060] Examples of amide solvents include formamide, N-methylformamide, N,N-dimethylformamide (DMF), acetamide, N-methylacetamide, N,N-dimethylacetamide, 2-pyrrolidone, and N-methylpyrrolidone.

[0061] Examples of glycol ether solvents include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol monoalkyl ethers; ethylene glycol dialkyl ethers such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether, propylene glycol monomethyl ether; propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-butyl ether; ethylene glycol dialkyl ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether; polyethylene glycol dialkyl ethers such as 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 dialkyl ethers such as propylene glycol dimethyl ether, propylene glycol diethyl ether, and propylene glycol dibutyl ether; 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 mono M ethylene glycol monoalkyl ether acetates such as ethylene glycol monoethyl ether acetate, ethylene glycol monoethyl ether acetate, and ethylene glycol monobutyl ether acetate; MExamples of the alkyl ether acetate include polyethylene glycol monoalkyl ether acetates such as 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.

[0062] Examples of ester solvents include methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, benzyl acetate, ethyl propionate, ethyl butyrate, butyl butyrate, valerolactone, and butyrolactone. etc.

[0063] Other solvents include, for example, dimethyl sulfoxide, sulfolane, γ-butyrolactone, and N-methyl-2-pyrrolidone.

[0064] In the production method (A), the solid content during the reaction is preferably 35 to 95% 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.

[0065] The reaction temperature is preferably within a range that does not decompose the catalyst used. If the reaction temperature is too high, the catalyst may decompose, stopping the reaction or degrading the resulting phenoxy resin. 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 typically 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 maintained by conducting the reaction under high pressure using an autoclave. If the heat of reaction needs to be removed, this is usually achieved by evaporation, condensation, and reflux of the solvent using the heat of reaction, indirect cooling, or a combination of these.

[0066] Next, the production method (B) of the present invention will be described. Production method (B) is a method for obtaining a phenoxy resin represented by formula (1) having a weight average molecular weight of 10,000 to 200,000, i.e., the phenoxy resin of the present invention, by reacting a phenoxy resin represented by formula (12) with an acylating agent in an amount of 0.05 to 2.0 moles of acyl groups per mole of alcoholic hydroxyl groups of the phenoxy resin.

[0067] The raw material phenoxy resin (a) is X in the above formula (12). 2 It essentially contains dioxy groups represented by the above formulas (2) and (3). This phenoxy resin (a) can be obtained by a conventional method. For example, a method (hereinafter referred to as a one-step method) includes reacting bifunctional phenolic compounds, essentially a bifunctional phenolic compound having the structure represented by the above formula (2) (sometimes referred to as bifunctional phenolic compound (a)) and a bifunctional phenolic compound having the structure represented by the above formula (3) (sometimes referred to as "bifunctional phenolic compound (b)"), with epihalohydrin in the presence of an alkali metal compound. Alternatively, a method (hereinafter referred to as a two-step method) includes reacting bifunctional epoxy resins having the structures represented by the above formulas (2) and (3) with bifunctional phenolic compounds in the presence of a catalyst. While the phenoxy resin (a) may be obtained by either method, the two-step method is preferred because phenoxy resins are generally easier to obtain by the two-step method than by the one-step method.

[0068] 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 the bifunctional phenolic compounds charged in the one-stage process, or by appropriately adjusting the molar ratio of the bifunctional epoxy resins and the bifunctional phenolic compounds charged in the two-stage process.

[0069] The bifunctional phenol compounds used in the one-stage and two-stage production processes are essentially bifunctional phenol compounds (a) and (b). Examples of the bifunctional phenol compound (a) include catechol, resorcinol, and hydroquinone, which may be substituted with a non-detrimental substituent such as an alkyl group or an aryl group. Examples of the bifunctional phenol compound (b) include 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, etc. These may be substituted with a non-detrimental substituent such as an alkyl group or an aryl group.

[0070] Other bifunctional phenol compounds may be used in combination as long as the object of the present invention is not impaired. Examples of bifunctional phenol compounds that may be used in combination 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, and 1,1-bi-2-naphthol. In addition, a plurality of types of these bifunctional phenol compounds may be used in combination.

[0071] First, the one-stage method will be described. In the one-step process, 0.985 to 1.015 moles, preferably 0.99 to 1.012 moles, and more preferably 0.995 to 1.01 moles, of epihalohydrin are reacted with 1 mole of bifunctional phenolic compounds in a non-reactive solvent in the presence of an alkali metal compound to allow the condensation reaction to proceed until the epihalohydrin is consumed and the weight-average molecular weight is 10,000 or more, thereby obtaining phenoxy resin (a). After completion of the reaction, the by-product salt must be removed by filtration or washing with water. Examples of alkali metal compounds include those similar to those used in the production of the bifunctional epoxy resin represented by formula (7) used in production method (A) of the present invention.

[0072] The molar ratio of the bifunctional phenolic compound (a) to the bifunctional phenolic compound (b) used as raw materials is preferably 1 / 9 to 9 / 1, more preferably 2 / 8 to 8 / 2, even more preferably 3 / 7 to 7 / 3, and particularly preferably 4 / 6 to 6 / 4. The total molar ratio of the bifunctional phenolic compound (a) to the bifunctional phenolic compound (b) is preferably 1 mol% or more, more preferably 20 mol% or more, even more preferably 50 mol% or more, and particularly preferably 75 mol% or more, based on the total number of moles of the bifunctional phenolic compounds. Outside this range, the heat resistance and folding endurance of the phenoxy resin of the present invention may be impaired.

[0073] This reaction can be carried out under normal pressure or under reduced pressure. The reaction temperature is 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, when carried out under normal pressure. The reaction temperature is preferably 20 to 100°C, more preferably 30 to 90°C, and even more preferably 35 to 80°C, when carried out under reduced pressure. A reaction temperature within this range makes it difficult for side reactions to occur and facilitates the reaction to proceed. The reaction pressure is usually normal pressure. Furthermore, when heat of reaction needs to be removed, this is usually achieved by evaporation, condensation, and reflux of the solvent used, indirect cooling, or a combination of these.

[0074] 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, butyl alcohol, etc. may be used. Only one type may be used, or two or more types may be used in combination.

[0075] Next, the two-stage method will be described. As the bifunctional epoxy resin serving as the raw material epoxy resin in the two-stage process, the same bifunctional epoxy resin as that represented by the above formula (7) used in the production method (A) of the present invention is used.

[0076] The bifunctional epoxy resin used as the raw material for the two-stage process is preferably the bifunctional epoxy resin represented by the above formula (7), but other bifunctional epoxy resins may be used in combination as long as the objectives of the present invention are not impaired. Examples of bifunctional epoxy resins that can be used in combination include bisphenol-type epoxy resins such as bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol S-type epoxy resins, bisphenolacetophenone-type epoxy resins, diphenyl sulfide-type epoxy resins, and diphenyl ether-type epoxy resins, biphenol-type epoxy resins, diphenyldicyclopentadiene-type epoxy resins, alkylene glycol-type epoxy resins, and alicyclic epoxy resins. 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.

[0077] In the two-stage process, a catalyst can be used, and any compound having catalytic activity that promotes the reaction between the epoxy group and the phenolic hydroxyl group can be used. Examples include the same catalysts as those exemplified in Production Method (A) of the present invention. The alkali metal compounds used in the production of the bifunctional epoxy resin represented by formula (7) above can also be used. These catalysts can be used alone or in combination of two or more. The amount used is also the same as that exemplified in Production Method (A) of the present invention.

[0078] In the two-stage process, a solvent may be used. Any solvent may be used as long as it dissolves the phenoxy resin and does not adversely affect the reaction. For example, the same solvents as those exemplified in the production method (A) of the present invention may be used. These solvents may be used alone or in combination of two or more.

[0079] 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 complete, the solvent can be removed by distillation or the like, as needed, or more solvent can be added.

[0080] The reaction temperature is set within a range that does not decompose the catalyst used. If the reaction temperature is too high, the catalyst may decompose, stopping the reaction or degrading the resulting phenoxy resin. 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 typically 1 to 12 hours, with 3 to 10 hours being preferred. When using low-boiling solvents such as acetone or methyl ethyl ketone, the reaction temperature can be maintained by conducting the reaction under high pressure using an autoclave. If the heat of reaction needs to be removed, this is typically achieved by evaporation, condensation, and reflux of the solvent using the reaction heat, indirect cooling, or a combination of these.

[0081] The phenoxy resin of the present invention can be obtained by acylation of the hydroxyl groups in the phenoxy resin (a) represented by the above formula (12) obtained in this manner. Acylation can be carried out by direct esterification or by a method such as transesterification.

[0082] Examples of the acid component used in the acylation include organic acids such as acetic acid, propionic acid, butyric acid, isobutyric acid, pentanoic acid, octanoic acid, caprylic acid, lauric acid, stearic acid, oleic acid, benzoic acid, t-butylbenzoic acid, hexahydrobenzoic acid, phenoxyacetic acid, acrylic acid, and methacrylic acid, as well as acid anhydrides, organic acid halides, and organic acid esters. Among these acylating agents, acid anhydrides represented by the following formula (13) are preferred.

[0083] [ka] In the formula, Z 2 is an acyl group having a hydrocarbon group having 1 to 20 carbon atoms.

[0084] Examples of the acid anhydrides of organic acids include acetic anhydride, benzoic anhydride, and phenoxyacetic anhydride. Examples of organic acid esters include methyl acetate, ethyl acetate, butyl acetate, methyl benzoate, ethyl benzoate, etc. Examples of organic acid halides include acetic acid chloride, benzoic acid chloride, phenoxyacetic acid chloride, etc.

[0085] The compound used for esterification is preferably an organic acid halide such as acetic acid chloride, benzoic acid chloride, or phenoxyacetic acid chloride, or an acid halide or an organic acid anhydride such as acetic anhydride, benzoic acid anhydride, or phenoxyacetic acid anhydride, and more preferably an acid anhydride such as acetic anhydride or benzoic acid anhydride, since this does not require washing with water after esterification and avoids contamination with halogens, which are undesirable in electrical materials applications.

[0086] The charge ratio of an acid component such as the organic acid, acid anhydride of an organic acid, halide of an organic acid, or 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 when the reactivity is low, the acid component may be charged in excess relative to the hydroxyl groups, and after the reaction reaches the target esterification ratio, the unreacted acid component may be removed. Here, the amount of acylating agent used relative to the raw material phenoxy resin (a) is 0.05 to 2.0 moles, preferably 0.1 to 1.0 mole, more preferably 0.2 to 0.8 moles of acyl groups per mole of alcoholic hydroxyl groups in the phenoxy resin (a). When the acylating agent is an acid anhydride represented by formula (13), it is understood that the acylating agent has 2 moles of acyl groups per mole of the acylating agent.

[0087] Direct esterification with an acid component can be carried out while dehydrating using various esterification catalysts, such as acid catalysts (e.g., paratoluenesulfonic acid, phosphoric acid, etc.) or metal catalysts (e.g., tetraisopropyl titanate, tetrabutyl titanate, dibutyltin oxide, dioctyltin oxide, zinc chloride, etc.) It is usually carried out in a nitrogen atmosphere at 100 to 250°C, more preferably 130 to 230°C.

[0088] When an acid halide or an acid anhydride is used for esterification, the resulting acid can be removed by any of the following methods, or a combination of these: a method of neutralizing with a basic compound and then filtering the salt; a method of neutralizing with a basic compound and then washing with water; a method of washing with water without neutralization; or a method of removing the acid by distillation or adsorption. When an acid having a boiling point lower than that of the reaction solvent is to be removed, it is preferable to remove it by distillation.

[0089] When the phenoxy resin (a) is esterified by transesterification, it is generally desirable to carry out the esterification under a nitrogen atmosphere while dealcoholizing the phenoxy resin (a) using a known esterification catalyst, such as dibutyltin oxide, dioctyltin oxide, a stannoxane catalyst, an organometallic catalyst such as tetraisopropyl titanate, tetrabutyl titanate, lead acetate, zinc acetate, or antimony trioxide, an acid catalyst such as hydrochloric acid, sulfuric acid, phosphoric acid, or sulfonic acid, or a basic catalyst such as lithium hydroxide or sodium hydroxide.

[0090] In the production method (B) of the present invention, a reaction solvent may be used. Any solvent that dissolves the phenoxy resin may be used. Examples include the solvents exemplified in the production method (A) of the present invention. These solvents may be the same as or different from those used in the preparation of the phenoxy resin (a). Furthermore, only one type may be used, or two or more types may be used in combination.

[0091] The resin composition of the present invention is a resin composition containing at least the phenoxy resin of the present invention and a curing agent. Furthermore, 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 needed. The resin composition of the present invention provides a cured product that satisfies the various physical properties required for various applications.

[0092] A resin composition can be prepared by blending a curing agent with the phenoxy resin of the present invention. In the present invention, the curing agent refers to a substance that contributes to a crosslinking reaction and / or a chain extension reaction with the phenoxy resin. In the present invention, even substances that are usually called "curing accelerators" can be used as curing accelerators for the phenoxy resin. and Any substance that contributes to crosslinking and / or chain extension reactions is considered a curing agent.

[0093] 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, more preferably 80 parts by mass or less, and even more preferably 60 parts by mass or less, per 100 parts by mass of the solid content of the phenoxy resin of the present invention.

[0094] When the resin composition of the present invention contains an epoxy resin described below, the weight ratio of the solid content of the phenoxy resin of the present invention to the epoxy resin is 99 / 1 to 1 / 99. In the present invention, the "solid content" refers to the components excluding the solvent, and includes not only solid phenoxy resins and epoxy resins, but also semi-solid and viscous liquids. Furthermore, the "resin component" refers to the total of the phenoxy resin of the present invention and the epoxy resin described below.

[0095] The curing agent used in the resin composition of the present invention is not particularly limited, and any commonly known curing agent for epoxy resins can be used. From the viewpoint of improving heat resistance, preferred curing agents include phenol-based curing agents, amide-based curing agents, imidazoles, and active ester-based curing agents. These curing agents may be used alone or in combination of two or more.

[0096] Examples of phenolic curing agents 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, Examples of the allylated phenol include 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, and allylated pyrogallol.

[0097] Examples of the amide-based curing agent include dicyandiamide and its derivatives, polyamide resins, and the like.

[0098] Examples of imidazoles include 2-phenylimidazole, 2-ethyl-4(5)-methylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazole] Examples of suitable 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 with 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.

[0099] Examples of active ester curing agents include compounds having two or more highly reactive ester groups per molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds. Among these, phenol esters obtained by reacting a carboxylic acid compound with an aromatic compound having a phenolic hydroxyl group are more preferred. Specific examples of carboxylic acid compounds include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid. Examples of aromatic compounds having a phenolic hydroxyl group include catechol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, dicyclopentadienyldiphenol, and phenol novolac.

[0100] Examples of other curing agents that can be used in the resin composition of the present invention include amine-based curing agents, acid anhydride-based curing agents, tertiary amines, organic phosphines, phosphonium salts, tetraphenylboron salts, organic acid dihydrazides, boron halide amine complexes, polymercaptan-based curing agents, isocyanate-based curing agents, blocked isocyanate-based curing agents, etc. These other curing agents may be used alone, or two or more may be mixed in any combination and ratio.

[0101] The resin composition of the present invention can contain an epoxy resin. The use of an epoxy resin can compensate for insufficient physical properties and improve various physical properties. The epoxy resin preferably has two or more epoxy groups in the molecule, and more preferably has 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 epoxy resins of the same type may be used in combination, or different types of epoxy resins may be used in combination.

[0102] 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.

[0103] 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, and aminophenol type epoxy resins.

[0104] Examples of polyglycidyl ester compounds include dimer acid type epoxy resins, hexahydrophthalic acid type epoxy resins, and trimellitic acid type epoxy resins.

[0105] Examples of the alicyclic epoxy compound include aliphatic cyclic epoxy resins such as CELLOXIDE 2021 (manufactured by Daicel Chemical Industries, Ltd.).

[0106] 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.), and phenoxy resins.

[0107] When the phenoxy resin and epoxy resin of the present invention are used in the resin composition of the present invention, the amount of epoxy resin in the total components of the phenoxy resin and epoxy resin as solids is preferably 1 to 99 mass%, more preferably 5 to 97 mass%, even more preferably 10 to 95 mass%, and still more preferably 10 to 90 mass%. By having the epoxy resin in the above amount, it is possible to improve the heat resistance and mechanical strength of a cured product made from the resin composition of the present invention.

[0108] 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 when 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.

[0109] 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, cyclohexanone, etc., esters such as ethyl acetate, ethers such as ethylene glycol monomethyl ether, amides such as N,N-dimethylformamide, N,N-dimethylacetamide, etc., alcohols such as methanol, ethanol, etc., alkanes such as hexane, cyclohexane, etc., aromatics such as toluene, xylene, etc. The above-mentioned solvents may be used alone, or two or more may be mixed in any combination and ratio.

[0110] 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.

[0111] These solvents or reactive diluents are preferably used in an amount of 90% by mass or less as nonvolatile matter, and the appropriate type and amount 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 nonvolatile matter. For adhesive film applications, for example, ketones, acetate esters, carbitols, aromatic hydrocarbons, dimethylformamide, dimethylacetamide, and N-methylpyrrolidone are preferred, and the amount used is preferably 30 to 60% by mass as nonvolatile matter.

[0112] If necessary, a curing accelerator (excluding those included in the term "curing agent") may be used in the resin composition of the present invention. Examples of the curing accelerator include imidazoles, tertiary amines, phosphorus compounds such as phosphines, metal compounds, Lewis acids, and amine complex salts. These curing accelerators may be used alone or in combination of two or more.

[0113] The amount of curing accelerator to be added may be appropriately selected depending on the intended use, but is preferably 0.01 to 15 parts by mass, more preferably 0.01 to 10 parts by mass, more preferably 0.05 to 8 parts by mass, and even more preferably 0.1 to 5 parts by mass, per 100 parts by mass of the epoxy resin component in the resin composition. Use of a curing accelerator can lower the curing temperature and shorten the curing time.

[0114] In order to improve the flame retardancy of the resulting cured product, various known flame retardants can be used in the resin composition of the present invention, as long as the reliability is not reduced. Usable flame retardants include, for example, 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.

[0115] 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. Examples of such other components include fillers, thermoplastic resins, thermosetting resins, photocurable resins, ultraviolet inhibitors, antioxidants, coupling agents, plasticizers, fluxes, thixotropic agents, smoothing agents, colorants, pigments, dispersants, emulsifiers, elasticity reducing agents, release agents, antifoaming agents, and ion trapping agents.

[0116] 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.

[0117] The resin composition of the present invention may contain a thermoplastic resin other than the 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, and polyvinyl formal resins. From the viewpoint of compatibility, phenoxy resins other than those of the present invention are preferred, and from the viewpoint of low dielectric properties, polyphenylene ether resins and modified polyphenylene ether resins are preferred.

[0118] Other components include organic pigments such as quinacridone, azo, and phthalocyanine pigments, inorganic pigments such as titanium oxide, metal foil pigments, and anti-rust 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 anti-foaming agents. The amount of these other components added is preferably 0.01 to 20% by mass of the total solids content in the resin composition.

[0119] The resin composition of the present invention can be obtained by uniformly mixing the above-mentioned components. Resin compositions containing a phenoxy resin, a curing agent, and, if necessary, various other components can be easily cured using methods similar to those known in the art. This cured product exhibits excellent balance of low moisture absorption, dielectric properties, heat resistance, adhesion, and other properties, and exhibits good cured physical properties. "Curing" here refers to intentionally curing the resin composition using heat and / or light, and the degree of curing can be controlled depending on the desired physical properties and application. The degree of curing may be fully cured or semi-cured, and is not particularly limited; however, the reaction rate of the curing reaction between the epoxy group and the curing agent is typically 5 to 95%.

[0120] The resin composition of the present invention can be cured to obtain a cured product by the same method as for known epoxy resin compositions. Methods for obtaining a cured product include those similar to those for known epoxy resin compositions, such as casting, injection, potting, dipping, drip coating, transfer molding, and compression molding, as well as laminating the resin in the form of a resin sheet, resin-coated copper foil, or prepreg, followed by heating and pressure curing to obtain a laminate. The curing temperature is typically in the range of 80 to 300°C, and the curing time is typically about 10 to 360 minutes. This heating is preferably carried out in two stages: a primary heating step at 80 to 180°C for 10 to 90 minutes, followed by a secondary heating step at 120 to 200°C for 60 to 150 minutes. Furthermore, for formulations whose glass transition temperature (Tg) exceeds the secondary heating temperature, a tertiary heating step at 150 to 280°C for 60 to 120 minutes is preferably carried out. Such secondary and tertiary heating steps can reduce poor curing. When producing a semi-cured resin product such as a resin sheet, a resin-coated copper foil, or a prepreg, the curing reaction of the resin composition is usually allowed to proceed to an extent that the shape can be maintained by heating, etc. When the resin composition contains a solvent, most of the solvent is usually removed by techniques such as heating, decompression, or air drying, but 5% by mass or less of the solvent may remain in the semi-cured resin product.

[0121] The prepreg obtained using the resin composition of the present invention will now be described. The sheet-like substrate can be, but is not limited to, a woven or nonwoven fabric made of inorganic fibers such as glass, or organic fibers such as polyester, polyamine, polyacrylic, polyimide, Kevlar, or cellulose. The method for producing a prepreg from the resin composition of the present invention and the substrate is not particularly limited. For example, the substrate can be immersed in a resin varnish obtained by adjusting the viscosity of the resin composition with a solvent, and then heated and dried to semi-cure (B-stage) the resin component. For example, the prepreg can be obtained by heating and drying at 100 to 200°C for 1 to 40 minutes. The resin content in the prepreg is preferably 30 to 80% by mass.

[0122] This section explains a method for manufacturing a laminate using prepreg or an insulating adhesive sheet. When forming a laminate using prepreg, one or more prepreg sheets are laminated together, and metal foil is placed on one or both sides to form a laminate. This laminate is then heated and pressed to form an integrated laminate. The metal foil used here can be a single, alloy, or composite metal foil made of copper, aluminum, brass, nickel, or the like. The conditions for heating and pressing the laminate can be appropriately adjusted to cure the resin composition. However, if the pressure is too low, air bubbles may remain inside the resulting laminate, resulting in reduced electrical properties. Therefore, it is desirable to pressurize under conditions that satisfy moldability. For example, a temperature of 160 to 220°C and a pressure of 49.0 to 490.3 N / cm are used. 2 (5-50kgf / cm 2 ) and heating time can be set from 40 to 240 minutes.

[0123] Furthermore, a multilayer board can be produced using the single-layer laminate thus obtained as an inner layer material. In this case, a circuit is first formed on the laminate by an additive method, a subtractive method, or the like, and the surface of the formed circuit is then 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 an insulating adhesive sheet, and a conductor layer is formed on the surface of the insulating layer to form a multilayer board.

[0124] When forming an insulating layer using an insulating adhesive sheet, a laminate is formed by placing an insulating adhesive sheet on the circuit-forming surfaces of multiple inner layer materials. Alternatively, a laminate is formed by placing an insulating adhesive sheet between the circuit-forming surfaces of the inner layer materials and metal foil. This laminate is then heated and pressurized to form an integral molding, thereby forming the cured insulating adhesive sheet as an insulating layer and forming a multilayer inner layer material. Alternatively, the inner layer material and the metal foil serving as the conductor layer are combined to form the cured 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. Furthermore, the hot and pressure 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 for forming the circuit on the outermost layer of the inner layer material is preferably applied to a thickness of 5 to 100 μm with the above-mentioned resin composition, and then heated and dried at 100 to 200°C for 1 to 90 minutes to form a sheet. This is generally formed by a method called a casting method. The thickness after drying is preferably formed 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 thus formed by an additive method or a subtractive method. Furthermore, by repeating the above process using this printed wiring board as an inner layer material, it is possible to form a multi-layer laminate.

[0125] When forming an insulating layer using 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 molding, whereby the cured prepreg is formed as an insulating layer and the outer metal foil is formed as a 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 can be carried out under the same conditions as those for molding the inner layer material. The surface of the multilayer laminate thus molded can 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, it is possible to form a multi-layer board with even more layers.

[0126] The cured product and laminate for electric / electronic circuits obtained from the resin composition of the present invention have excellent flame retardancy and heat resistance. [Example]

[0127] The present invention will be explained in more detail below based on examples and comparative examples, but the present invention is not limited thereto. Unless otherwise specified, parts represent parts by mass and % represents % by mass. Analytical and measurement methods are shown below. Furthermore, the unit of various equivalents is g / eq.

[0128] (1) Weight average molecular weight (Mw) and number average molecular weight (Mn): The Mw was determined by GPC measurement. Specifically, a HLC8320 GPC (Tosoh Corporation) was used, equipped with columns (TSKgel SuperH-H, SuperH2000, SuperHM-H, SuperHM-H, all Tosoh Corporation) in series. The column temperature was 40°C. The eluent was DMF (containing 20 mM lithium bromide) at a flow rate of 0.3 mL / min, and a refractive index detector was used. 0.1 g of solids was dissolved in 10 mL of DMF and filtered through a 0.45 μm microfilter. 20 μL of the sample was used. Mw was calculated from a calibration curve obtained from standard polyethylene oxides (Tosoh Corporation: SE-2, SE-5, SE-8, SE-15, SE-30, SE-70, and SE-150). Data processing was performed using a GPC8020 Model II version 6.00 (Tosoh Corporation).

[0129] (2) Epoxy equivalent: Measurements were carried out in accordance with JIS K 7236. Specifically, a potentiometric titrator was used, cyclohexanone was used as the solvent, tetraethylammonium bromide acetate solution was added, and a 0.1 mol / L perchloric acid-acetic acid solution was used. For solvent-diluted products (resin varnishes), the solid content was calculated from the nonvolatile content.

[0130] (3) Nonvolatile content: Measurement was performed in accordance with JIS K 7235. The drying temperature was 200°C and the drying time was 60 minutes.

[0131] (4) Glass transition temperature (Tg): Measurements were performed in accordance with IPC-TM-650 2.4.25.c. Specifically, a 4 mm thick, 3 mm diameter sample was measured using a differential scanning calorimeter (EXSTAR6000 DSC6200, manufactured by SII NanoTechnology Inc.) in the range of 20 to 280°C at a temperature increase rate of 10°C / min for two cycles, and the glass transition temperature (Tmg) was expressed as the midpoint of the second scan measurement chart.

[0132] (5) Dielectric properties: The dielectric loss tangent was evaluated using the cavity resonator perturbation method at 1 GHz. Specifically, measurements were performed using a PNA network analyzer N5230A (Agilent Technologies) and a cavity resonator CP431 (Kanto Electronics Application Development Co., Ltd.) at a room temperature of 23°C and a humidity of 50% using a test piece measuring 1.5 mm wide, 80 mm long, and 150 μm thick.

[0133] (6) Folding resistance: The film was evaluated in a folding fatigue test by the number of times it could be folded until it broke. Specifically, a test piece measuring 15 mm wide x 100 mm long x 100 μm thick was used, and the test was carried out using an MIT folding fatigue tester, Model D (manufactured by Toyo Seiki Co., Ltd.) under the conditions of a load of 0.5 kgf, a speed of 90 cpm, an angle of 45 degrees, and an R of 0.38 mm.

[0134] The abbreviations used in the examples and comparative examples are as follows:

[0135] [Bifunctional epoxy resin] A1: Hydroquinone-type epoxy resin (Nippon Steel Chemical & Material Co., Ltd., ZX-1027, epoxy equivalent 131, m≒0.18) A2: Resorcinol-type epoxy resin (Sigma-Aldrich, epoxy equivalent 127, m≒0.14) A3: 2,5-di-t-butylhydroquinone type epoxy resin (Nippon Steel Chemical & Material Co., Ltd., Epotohto YDC-1213, epoxy equivalent 175, m≒0.05) A4: Naphthalene-type epoxy resin (DIC Corporation, Epicron HP4032D, epoxy equivalent 142, m≒0.07) A5: Bisphenol A liquid epoxy resin (Nippon Steel Chemical & Material Co., Ltd., Epotohto YD-128, epoxy equivalent 186) Here, m has the same meaning as m in the above formula (7).

[0136] [Diester compounds] B1: 2,6-diacetoxynaphthalene (Tokyo Chemical Industry Co., Ltd., active equivalent weight = 122) B2: 1,4-diacetoxynaphthalene (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., active equivalent weight = 122) B3: 2,2-bis(4-acetoxyphenyl)propane (Tokyo Chemical Industry Co., Ltd., active equivalent weight = 156)

[0137] [Bifunctional phenolic compounds] C1: 2,6-naphthalenediol (Tokyo Chemical Industry Co., Ltd., hydroxyl equivalent: 80)

[0138] [catalyst] D1: N,N'-dimethylaminopyridine (Tokyo Chemical Industry Co., Ltd.) D2: 2-ethyl-4-methylimidazole (Curesol 2E4MZ, manufactured by Shikoku Chemicals Corporation)

[0139] [Solvents] S1: Cyclohexanone S2: Methyl ethyl ketone (MEK)

[0140] [Acid anhydride] E1: Acetic anhydride (Fujifilm Wako Pure Chemical Industries, Ltd.) E2: Benzoic anhydride (Tokyo Chemical Industry Co., Ltd.)

[0141] [Hardening agent] H1: Phenol novolac resin (manufactured by Aica Kogyo Co., Ltd., Shounol BRG-5575, hydroxyl group equivalent: 105)

[0142] Example 1 A glass reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet, condenser, and dropping device was charged with 100 parts of A1, 89 parts of B1, and 47 parts of S1 as a reaction solvent at room temperature. The mixture was heated to 130°C while stirring and nitrogen gas was passed through, and 0.2 parts of D1 was added as a catalyst. The mixture was then heated to 145°C and reacted at the same temperature for 7 hours. A phenoxy resin varnish (R1) with a nonvolatile content of 40% was obtained by diluting and mixing using 47 parts of S1 and 189 parts of S2 as dilution solvents.

[0143] Examples 2 to 8, Comparative Examples 1 to 3 Phenoxy resin varnish was obtained in the same manner as in Example 1, using the amounts (parts) of each raw material shown in Tables 1 and 2. The molar ratios in the tables represent the molar ratios of the difunctional epoxy resin to the diester compound and the difunctional phenol compound, and varnish represents the phenoxy resin varnish.

[0144] [Table 1]

[0145] [Table 2]

[0146] Example 10 100 parts (40 parts solids) of the phenoxy resin varnish (RH3) obtained in Comparative Example 3 and 600 parts of S1 were blended, and after heating to 100°C, 5 parts of E1 were added and the reaction was carried out for 4 hours. The resulting resin varnish was added to methanol, and the precipitated insoluble matter was filtered off. The filtrate was then dried in a vacuum dryer at 150°C and 0.4 kPa (3 torr) for 1 hour to obtain a phenoxy resin. 21 parts of S1 and 42 parts of S2 were added to the resulting phenoxy resin and dissolved uniformly to obtain a phenoxy resin varnish (R10) with a nonvolatile content of 40%.

[0147] Example 11 A phenoxy resin varnish (R11) was obtained in the same manner as in Example 10, except that 23 parts of E1, 25 parts of dilution solvent S1, and 49 parts of dilution solvent S2 were used.

[0148] Example 12 A phenoxy resin varnish (R12) was obtained by the same procedure as in Example 10, except that 51 parts of E2 were used instead of E1, and 31 parts of S1 and 62 parts of S2 were used as dilution solvents.

[0149] The resin varnishes R1 to R12 and RH1 to RH3 obtained in Examples 1 to 12 and Comparative Examples 1 to 3 were applied to iron plates so that the film thickness after drying would be 100 μm and 150 μm, respectively, and dried in a dryer at 150°C for 1 hour to obtain resin films. The epoxy equivalent and Mw of the phenoxy resin varnish were measured, and the Tg, dielectric properties, and folding endurance of the resin film were measured. The results are shown in Table 3. In the table, "Formula (2) content" represents the content (mol %) of the structure of formula (2) in all X in formula (1), "Formula (3) content" represents the content (mol %) of the structure of formula (3) in all X in formula (1), and "acylation rate" represents the content (mol %) of acyl groups in all Z. Examples using resin varnishes RH1 to RH3 are comparative examples.

[0150] [Table 3]

[0151] Examples 13 to 15, Comparative Examples 4 to 5 A resin composition was prepared by blending 30 parts (12 parts solids) of the phenoxy resin varnishes (R1, R2, R4, RH1-RH3) obtained in Examples 1, 2, and 4 and Comparative Examples 1-3 with 2 parts of A5 as an epoxy resin, 2.5 parts of H1 in a 50% MEK solution as a curing agent, and 0.6 parts of C2 in a 20% MEK solution as a curing accelerator. These compositions were then applied to iron plates to dry to thicknesses of 100 and 150 μm, and dried in a dryer at 150°C for 1 hour to obtain cured films. The Tg, dielectric properties, and folding endurance were measured. The results are shown in Table 4.

[0152] [Table 4]

[0153] As can be seen from Table 3, the phenoxy resins of the present invention shown in Examples 1 to 12 are excellent in heat resistance, dielectric properties, and folding resistance. Furthermore, as can be seen from Table 4, the cured products made from the resin compositions of the present invention are also excellent in heat resistance, dielectric properties, and folding resistance.

[0154] The phenoxy resin and resin composition of the present invention are applicable to various fields such as adhesives, paints, civil engineering and building materials, and insulating materials for electric and electronic components, and are particularly useful in the electric and electronic fields as insulating casting materials, laminate materials, sealing materials, etc. The phenoxy resin and resin composition containing the same of the present invention can be suitably used in laminates for electric and electronic circuits such as multilayer printed wiring boards and 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.

Claims

1. A phenoxy resin represented by the following formula (1) and having a weight average molecular weight of 10,000 to 200,000: 【Chemical 1】 In the formula, X is independently a divalent group containing a dioxy group represented by the following formula (2) or formula (3), and as X in formula (1), the molar ratio of the dioxy group represented by formula (2) to the dioxy group represented by formula (3) (formula 2 / formula 3) is 1 / 9 to 9 / 1, and the total amount of the dioxy groups represented by formula (2) and formula (3) is 50 mol % or more relative to the total number of moles of X. Each Y is independently a hydrogen atom, an acyl group having a hydrocarbon group of 1 to 20 carbon atoms, or a glycidyl group. Z is an acyl group having a hydrocarbon group of 1 to 20 carbon atoms or a hydrogen atom, and 5 mol % or more of Z is the above acyl group. n is the average number of repeating units, and is 15 to 500. 【Chemistry 2】 In formula (2) and formula (3), each R is independently a group selected from the group consisting of an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 13 carbon atoms, an aryloxy group having 6 to 12 carbon atoms, an aralkyloxy group having 7 to 13 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, and an alkynyl group having 2 to 12 carbon atoms; i is an integer of 0 to 4; and j is an integer of 0 to 6.

2. A resin composition comprising the phenoxy resin according to claim 1 and a curing agent.

3. 3. The resin composition according to claim 2, comprising 0.1 to 100 parts by mass of the curing agent as a solid content per 100 parts by mass of the solid content of the phenoxy resin.

4. 3. The resin composition according to claim 2, comprising the phenoxy resin according to claim 1, an epoxy resin, and a curing agent, wherein the mass ratio of the solid content of the phenoxy resin to the solid content of the epoxy resin is 99 / 1 to 1 / 99.

5. 5. The resin composition according to claim 4, comprising 0.1 to 100 parts by mass of the curing agent as solid content per 100 parts by mass of the total solid content of the phenoxy resin and the epoxy resin.

6. The resin composition according to any one of claims 2 to 5, 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, polyisocyanate compounds, blocked isocyanate compounds, and active ester curing agents.

7. A cured product obtained by curing the resin composition according to any one of claims 2 to 6.

8. A laminate for electric / electronic circuits, which is obtained by using the resin composition according to any one of claims 2 to 6.

9. A method for producing a phenoxy resin, comprising reacting a bifunctional epoxy resin represented by the following formula (7) with a compound represented by the following formula (8) to obtain a phenoxy resin represented by the following formula (1) having a weight average molecular weight of 10,000 to 200,000: 【Chemistry 3】 In the formula, X １ are independently divalent groups containing a dioxy group represented by the following formula (2) or formula (3), and X in formula (7) and formula (8) １ These include, as a whole, dioxy groups represented by formula (2) and formula (3), where G is a glycidyl group. Z １ is an acyl group having a hydrocarbon group of 1 to 20 carbon atoms or a hydrogen atom, and 5 mol % or more of the acyl group is the above. １ The compound may be a mixture of two or more compounds selected from compounds in which both of the above groups are acyl groups, compounds in which one of the above groups is an acyl group, and compounds in which both of the above groups are hydrogen atoms. m is the average number of repetitions and is 0 to 6. 【Chemistry 4】 In the formula, each R is independently a group selected from the group consisting of an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 13 carbon atoms, an aryloxy group having 6 to 12 carbon atoms, an aralkyloxy group having 7 to 13 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, and an alkynyl group having 2 to 12 carbon atoms; i is an integer of 0 to 4; and j is an integer of 0 to 6. 【Chemistry 5】 In the formula, X is independently a divalent group containing a dioxy group represented by the above formula (2) or formula (3), and as X in formula (1), the molar ratio of the dioxy group represented by formula (2) to the dioxy group represented by formula (3) (formula 2 / formula 3) is 1 / 9 to 9 / 1, and the total amount of the dioxy groups represented by formula (2) and formula (3) is 50 mol % or more relative to the total number of moles of X. Each Y is independently a hydrogen atom, an acyl group having a hydrocarbon group of 1 to 20 carbon atoms, or a glycidyl group. Z is an acyl group having a hydrocarbon group of 1 to 20 carbon atoms or a hydrogen atom, and 5 mol % or more of Z is the above acyl group. n is the average number of repeating units, and is 15 to 500.

10. A method for producing a phenoxy resin, comprising reacting 0.05 moles or more and 2.0 moles or less of an acyl group of an acylating agent with 1 mole of an alcoholic hydroxyl group of a phenoxy resin represented by the following formula (12), to obtain a phenoxy resin represented by the following formula (1) having a weight average molecular weight of 10,000 to 200,000. 【Chemistry 6】 In the formula, X 2 are independently divalent groups containing dioxy groups represented by the following formula (2) or formula (3), the molar ratio of the dioxy groups represented by formula (2) to the dioxy groups represented by formula (3) (formula 2 / formula 3) is 1 / 9 to 9 / 1, and the total amount of the dioxy groups represented by formula (2) and formula (3) is X ２ The amount is 50 mol % or more based on the total number of moles. Y 2 are each independently a hydrogen atom or a glycidyl group, and n is the average number of repeating groups, and is 15 to 500. 【Chemistry 7】 In the formula, each R is independently a group selected from the group consisting of an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 13 carbon atoms, an aryloxy group having 6 to 12 carbon atoms, an aralkyloxy group having 7 to 13 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, and an alkynyl group having 2 to 12 carbon atoms; i is an integer of 0 to 4; and j is an integer of 0 to 6. 【Chemistry 8】 In the formula, X and n are respectively X in formula (12). ２ , n are the same as above. Each Y is independently a hydrogen atom, an acyl group having a hydrocarbon group of 1 to 20 carbon atoms, or a glycidyl group. Z is an acyl group having a hydrocarbon group of 1 to 20 carbon atoms or a hydrogen atom, and 5 mol % or more of Z is the above acyl group.

Images