Polyhydroxy polyether resin, production method for same, resin composition, and cured product

Abstract

The present invention provides: a polyhydroxy polyether resin having a sulfide skeleton with low viscosity and excellent heat resistance, adhesiveness, elasticity, and strength; a production method for the same; and a resin composition and a cured product which use the resin.　Provided is a polyhydroxy polyether resin represented by general formula (1), wherein the sulfur content is greater than 3 mass% but less than 12 mass%, and the weight-average molecular weight is 10,000-200,000. (In the formula, each R is independently a hydrogen atom, a C1-12 alkyl group, a C1-12 alkoxy group, a C2-12 alkenyl group, or a C2-12 alkynyl group. Each Z is independently a divalent group and is a structure represented by general formula (2), general formula (3), or general formula (4). G is a hydrogen atom or a glycidyl group. n is number of repetitions, and the average value thereof is 5-1000.)

Description

Polyhydroxypolyether resin, method for producing the same, resin composition, and cured product

[0001] This invention relates to a polyhydroxypolyether resin that exhibits excellent heat resistance, low viscosity, high adhesion, high elasticity, and strength. It also relates to a method for producing the polyhydroxypolyether resin, a resin composition containing the polyhydroxypolyether resin, and a cured product thereof.

[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. Film-forming properties can be enhanced by increasing their molecular weight through various methods. These high-molecular-weight epoxy resins are called polyhydroxy polyether resins or phenoxy resins. In particular, bisphenol A type polyhydroxy polyether resins are mainly used as base resins for paint varnishes and film molding, added to epoxy resin varnishes to adjust fluidity, improve toughness and adhesion of cured products. Furthermore, those containing phosphorus or bromine atoms in their backbone are used as flame retardants in epoxy resin compositions and thermoplastic resins.

[0003] Patent Document 1 discloses a resin composition comprising a polyhydroxypolyether resin having a bisphenol sulfone (bisphenol S) skeleton, and states that it has excellent adhesion, bonding properties, heat resistance, and solvent resistance. Patent Document 2 discloses a sulfone group-containing polyhydroxypolyether resin having a bisphenol S skeleton with substituents such as methyl groups, and states that it has good solvent solubility and excellent moisture resistance. Polyhydroxypolyether resins improve adhesion between the resin layer and the metal plate due to the interaction between the S atoms in the molecule and the metal atoms of the metal plate, resulting in excellent insulation resistance after moisture absorption. Furthermore, substituents such as methyl groups improve solvent solubility and make handling easier.

[0004] On the other hand, polyhydroxy polyether resins with a bisphenol S skeleton have strong intermolecular interactions and high viscosity, resulting in drawbacks such as poor process properties and limitations on the amount that can be used in formulation. Furthermore, when heat resistance is to be imparted, it is necessary to introduce a rigid skeleton, which further increases the viscosity of the resulting polyhydroxy polyether resin. In recent years, there has been a desire to lower the curing temperature in the curing process from the perspective of thermal stress strain, and low-temperature, short-time curing is also desirable from the perspective of carbon neutrality. It is expected that the demand for improving the viscosity properties of resins to meet these requirements will increase even further in the future.

[0005] Japanese Patent Publication No. 50-116544, Japanese Patent Publication No. 2011-144319

[0006] The object of the present invention is to provide a polyhydroxy polyether resin, its composition, and a cured product that exhibits excellent properties even in low-temperature curing and short-time curing, by reducing the resin viscosity while maintaining the properties of a polyhydroxy polyether resin which has excellent heat resistance, adhesiveness, high elasticity, and strength.

[0007] The inventors diligently studied the molecular framework of polyhydroxypolyether resins and, as a result, discovered that polyhydroxypolyether resins having a specific structure can maintain low viscosity, enabling low-temperature curing and short-time curing, while maintaining high physical properties such as heat resistance, adhesion, high elasticity, and strength. This led to the completion of the present invention.

[0008] In other words, the present invention relates to a polyhydroxy polyether resin represented by the following general formula (1), having a sulfur content greater than 3% by mass and less than 12% by mass, and a weight-average molecular weight of 10,000 to 200,000. (In the formula, R is independently a hydrogen atom, a C1-C12 alkyl group, a C1-C12 alkoxy group, a C2-C12 alkenyl group, or a C2-C12 alkynyl group. Z is independently a divalent group and has a structure represented by general formula (2), general formula (3), or general formula (4). G is a hydrogen atom or a glycidyl group. n is the number of repetitions, and its average value is between 5 and 1000.) (In the formula, R is the same as in general formula (1). X is independently directly bonded, -CH ２ -, -C(CH ３ ) ２ -, -CH(CH ３ )-, -O-, -CO-, -SO ２ It exhibits one or more of the following structures: -, -S-, or general formula (2a). (In the formula, R is the same as in general formula (1). * indicates the bond position.) (In the formula, R is the same as in general formula (1). * indicates the bond position.) (In the formula, R is the same as in general formula (1). * indicates the bond position.)

[0009] Furthermore, the present invention relates to a method for producing the polyhydroxypolyether resin by reacting a difunctional epoxy resin with a difunctional phenol compound, characterized in that it uses either or both of a difunctional epoxy resin represented by general formula (5) and a difunctional phenol compound represented by general formula (6). (In the formula, R is the same as in general formula (1). m is the number of repetitions, ranging from 0 to 10.) (In the formula, R is the same as in general formula (1).)

[0010] Furthermore, the present invention relates to a resin composition comprising the polyhydroxypolyether resin and a curing agent, and a resin composition comprising the polyhydroxypolyether resin, an epoxy resin and a curing agent. Moreover, it relates to a sheet-like resin composition obtained by semi-curing these resin compositions, and a cured product obtained by curing the aforementioned resin compositions.

[0011] According to the present invention, it is possible to obtain a polyhydroxypolyether resin, as well as its composition and cured product, that is heat-resistant, adhesive, highly elastic, highly strong, and low-viscosity, and can also be used for low-temperature curing and short-time curing.

[0012] This is the GPC chart for the polyhydroxypolyether resin of Example 5. This is the IR chart for the polyhydroxypolyether resin of Example 5.

[0013] The polyhydroxypolyether resin of the present invention is represented by the general formula (1) above, has a sulfur content greater than 3% by mass and less than 12% by mass, and a weight-average molecular weight of 10,000 to 200,000. Here, in formula (1), the hydrogen atom or glycidyl group represented by G can be adjusted to contain either one or both by adjusting the ratio of the synthetic raw materials. That is, by adjusting the ratio of difunctional phenols to epihalohydrins, or by adjusting the ratio of difunctional epoxy resin to difunctional phenols and reacting them, the terminal groups of the polyhydroxypolyether resin can be controlled to desired functional groups.

[0014] The structure represented by general formula (1), that is, the so-called bisphenol sulfide structure, provides heat resistance, adhesion, high elasticity, and high strength, and allows for significantly lower viscosity than the bisphenol S structure. Furthermore, Z in general formula (1) is independently the structure represented by general formulas (2), (3), or (4).

[0015] Specific examples of R in the general formulas (1), (2), (2a), (3), (4), (5), and (6) are, independently, a hydrogen atom, a C1-C12 alkyl group, a C1-C12 alkoxy group, a C2-C12 alkenyl group, or a C2-C12 alkynyl group.

[0016] The alkyl group having 1 to 12 carbon atoms may be linear, branched, or cyclic. Examples include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, t-butyl group, n-pentyl group, isopentyl group, neopentyl group, t-pentyl group, cyclopentyl group, n-hexyl group, isohexyl group, cyclohexyl group, n-heptyl group, cycloheptyl group, methylcyclohexyl group, n-octyl group, cyclooctyl group, n-nonyl group, 3,3,5-trimethylcyclohexyl group, n-decyl group, cyclodecyl group, n-undecyl group, n-dodecyl group, and cyclododecyl group.

[0017] The alkoxy group having 1 to 12 carbon atoms may be linear, branched, or cyclic. Examples include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, t-butoxy, n-pentoxy, isopentoxy, neopentoxy, t-pentoxy, cyclopentoxy, n-hexyloxy, isohexyloxy, cyclohexyloxy, n-heptoxy, cycloheptoxy, methylcyclohexyloxy, n-octyloxy, cyclooctyloxy, n-nonyloxy, 3,3,5-trimethylcyclohexyloxy, n-decyloxy, cyclodecyloxy, n-undecyloxy, n-dodecyloxy, and cyclododecyloxy groups.

[0018] Examples of alkenyl groups having 2 to 12 carbon atoms include vinyl group, 1-propenyl group, 2-propenyl group, 1-methylvinyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, 1,3-butadienyl group, cyclohexenyl group, cyclohexadienyl group, cinnamyl group, naphthylvinyl group, and the like.

[0019] Examples of alkynyl groups having 2 to 12 carbon atoms include ethynyl group, 1-propynyl group, 2-propynyl group, 1-butynyl group, 2-butynyl group, 3-butynyl group, 1,3-butadiinyl group, phenylethynyl group, naphthylethynyl group, and the like.

[0020] A polyhydroxypolyether resin containing the bisphenol sulfide skeleton of general formula (1) can be produced by using one or more of the difunctional epoxy resin of general formula (5) containing the bisphenol sulfide skeleton and the difunctional phenol compound of general formula (6), that is, either or both of these, as raw materials for the reaction.

[0021] Specific examples of difunctional phenol compounds of general formula (6) include bisphenols such as bisphenol sulfide, dimethylbisphenol sulfide, tetramethylbisphenol sulfide, dimethyldiethylbisphenol sulfide, and dimethyldibutylbisphenol sulfide, and their epoxidized products are examples of epoxy resins of general formula (5).

[0022] The structure represented by Z in the general formula (1) includes the structure derived from the bifunctional phenols of the general formula (2). X in the general formula (2) is independently a direct bond, -CH ２ -, -C(CH ３ ) ２ -, -CH(CH ３ ) -, -O -, -CO -, -SO ２ -, -S - or has the structure represented by the general formula (2a). The subscript (number) of the R group such as the general formula (2a) indicates the number of substitutions on the cyclohexane ring or naphthalene ring. Specific examples giving the structure derived from such bifunctional phenols include bisphenol A, dimethyl bisphenol A, bisphenol F, bisphenol B, bisphenol E, bisphenol C, bisphenol S, dimethyl bisphenol S, tetramethyl bisphenol S, bisphenol Z, bisphenol acetophenone, bisphenol phenyl ethylidene such as 4,4'-(1-phenylethylidene) bisphenol, bisphenol cyclohexylidene such as 4,4'-cyclohexylidene bisphenol (bisphenol Z), bisphenol methyl cyclohexylidene such as 4,4'-(4-methylcyclohexylidene) bisphenol, bisphenol trimethyl cyclohexylidene such as 4,4'-(3,3,5-trimethyl-1,1-cyclohexanediyl) bis(bisphenol) (bisphenol TMC), bisphenol dimethyl butylidene such as 4,4'-(1,3-dimethylbutylidene) diphenol, dihydroxybiphenyl ether, bisphenols such as the structure shown as an example of the general formula (6), and biphenols such as 4,4'-biphenol, 2,4'-biphenol, and tetramethyl biphenol, and their epoxidized products are also included.

[0023] Specific examples containing the skeleton of the general formula (3) include benzene diols such as hydroquinone, methyl hydroquinone, dibutyl hydroquinone, resorcinol, catechol, and methyl resorcinol, and their epoxidized products are also included.

[0024] Specific examples containing the skeleton of general formula (4) include dihydroxynaphthalene, dihydroxynaphthalene with substituents, and other bifunctional phenol compounds, as well as their epoxidized products.

[0025] In general formula (1), n ​​is the number of repeats, and its average value ranges from 5 to 1000. From the viewpoint of moldability and handling, it is preferably 7 to 800, and more preferably 10 to 600. Furthermore, the number of n can be calculated from the number-average molecular weight (Mn) obtained by gel permeation chromatography (GPC). The number of n can be determined by dividing the number-average molecular weight (Mn) by the number of terminal functional groups (epoxy equivalent, phenolic hydroxyl group equivalent).

[0026] The resin represented by general formula (1) has a sulfur content greater than 3% by mass and less than 12% by mass. If the sulfur content is 3% by mass or less, the adhesiveness, heat resistance, and low viscosity properties may not be sufficient, while a new skeletal material is required to achieve a sulfur content of 12% by mass or more. The lower limit of the preferred sulfur content is 3.5% by mass or more, and more preferably 4.0% by mass or more. On the other hand, the upper limit of the preferred sulfur content is 11.5% by mass or less, and more preferably 10% by mass or less. Here, the "sulfur content" in this invention represents the content of sulfur atoms in the polyhydroxypolyether resin, and can be specifically measured by the method described in the examples. It can also be determined by calculation from the sulfur content in the raw materials and the amount of raw materials used.

[0027] The present invention's method for producing polyhydroxypolyether resin can utilize a so-called one-stage method in which bisphenols and epihalohydrins are reacted. However, since components with different reactivity may be used, it can be difficult to control each structural component solely by the raw material ratio. Therefore, it is preferable to use a production method in which a difunctional epoxy resin and a difunctional phenol compound are reacted, a so-called two-stage method. In the two-stage method, the desired range of resin can be produced by appropriately adjusting the molar ratio of the difunctional epoxy resin and the difunctional phenol compound.

[0028] In the manufacturing method of the present invention, a catalyst may be used, and any compound having catalytic activity to promote the reaction between epoxy groups and phenol groups may be used as the catalyst. Examples include tertiary amines, cyclic amines, imidazoles, organophosphorus compounds, and quaternary ammonium salts. These catalysts may be used individually or in combination of two or more.

[0029] Examples of tertiary amines include, but are not limited to, triethylamine, tri-n-propylamine, tri-n-butylamine, triethanolamine, benzyldimethylamine, and 2,4,6-tris(dimethylaminomethyl)phenol.

[0030] 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).

[0031] 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.

[0032] Examples of the organophosphorus compounds include, but are not limited to, phosphines such as tri-n-propylphosphine, tri-n-butylphosphine, diphenylmethylphosphine, triphenylphosphine, tris(p-tolyl)phosphine, tricyclohexylphosphine, tri(t-butyl)phosphine, tris(p-methoxyphenyl)phosphine, tris(dimethoxyphenyl)phosphine, paramethylphosphine, 1,2-bis(dimethylphosphino)ethane, 1,4-bis(diphenylphosphino)butane, and phosphonium salts such as tetramethylphosphonium bromide, tetramethylphosphonium iodide, tetramethylphosphonium hydroxide, tetrabutylphosphonium bromide, tetrabutylphosphonium hydroxide, trimethylcyclohexylphosphonium chloride, trimethylcyclohexylphosphonium bromide, trimethylbenzylphosphonium chloride, trimethylbenzylphosphonium bromide, tetraphenylphosphonium bromide, triphenylmethylphosphonium bromide, triphenylmethylphosphonium iodide, triphenylethylphosphonium chloride, triphenylethylphosphonium bromide, triphenylethylphosphonium iodide, triphenylbenzylphosphonium chloride, triphenylbenzylphosphonium bromide.

[0033] Examples of the 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, phenyltrimethylammonium chloride.

[0034] Among the catalysts listed above, triethylamine, 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, tetrabutylphosphonium bromide, tricyclohexylphosphine, tri(t-butyl)phosphine, tris(p-methoxyphenyl)phosphine are preferred, and particularly tetrabutylphosphonium bromide and tris(p-methoxyphenyl)phosphine are preferred.

[0035] The amount of the catalyst used is usually 0.001 to 1% by mass in the reaction solids. However, when these compounds are used as the catalyst, these catalysts may remain as residues in the obtained polyhydroxy polyether resin, which may deteriorate the insulation properties of the printed wiring board or shorten the pot life of the composition. Therefore, the nitrogen content in the polyhydroxy polyether resin is preferably 0.5% by mass or less, more preferably 0.3% by mass or less. Also, the phosphorus content in the polyhydroxy polyether resin is preferably 0.5% by mass or less, more preferably 0.3% by mass.

[0036] In the production method of the present invention, a reaction solvent may be used. As the solvent, any solvent that dissolves the polyhydroxy polyether resin and does not react with an epoxy group or a phenol group may be used. For example, aromatic solvents, ketone solvents, amide solvents, glycol ether solvents, ester solvents, etc. may be mentioned. Also, these solvents may be used alone or in combination of two or more.

[0037] Examples of the aromatic solvent include benzene, toluene, xylene, etc.

[0038] Examples of the ketone solvent include acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, 2-heptanone, 4-heptanone, 2-octanone, cyclohexanone, acetylacetone, diisobutyl ketone, isophorone, methylcyclohexanone, acetophenone, etc.

[0039] Examples of amide solvents include formamide, N-methylformamide, N,N-dimethylformamide (DMF), acetamide, N-methylacetamide, N,N-dimethylacetamide, 2-pyrrolidone, and N-methylpyrrolidone.

[0040] Examples of glycol ether solvents include ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and ethylene glycol mono-n-butyl ether; diethylene glycol monoalkyl ethers such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol mono-n-butyl ether; propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, and propylene glycol mono-n-butyl ether; ethylene glycol dialkyl ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and ethylene glycol dibutyl ether; and polyethylene ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, and triethylene glycol dibutyl ether. Diethylene glycol dialkyl ethers, propylene glycol dialkyl ethers such as propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dibutyl ether, etc., 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, tripropylene glycol dibutyl ether, etc., ethylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, etc., diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, triethylene glycol monomethyl ether acetate, triethylene glycol monoethyl ether acetate,Examples include polyethylene glycol monoalkyl ether acetates such as 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.

[0041] 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.

[0042] Other solvents include, for example, dimethyl sulfoxide, sulfolane, and dioxane.

[0043] In the manufacturing method of the present invention, the solid content concentration during the reaction is preferably 35 to 95% by mass. Furthermore, if a highly viscous product is formed during the reaction, additional solvent can be added to continue the reaction. After the reaction is complete, the solvent can be removed or added as needed.

[0044] The reaction temperature should be 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 polyhydroxypolyether resin. If the reaction temperature is too low, the reaction may not proceed sufficiently, and the desired molecular weight may not be achieved. Therefore, the reaction temperature is preferably 50 to 230°C, more preferably 120 to 200°C. The reaction time is usually 1 to 12 hours, preferably 3 to 10 hours. When using low-boiling point solvents such as acetone or methyl ethyl ketone, the reaction temperature can be ensured by carrying out the reaction under high pressure using an autoclave. If it is necessary to remove the heat of reaction, this is usually done by evaporation, condensation, reflux of the solvent using the heat of reaction, indirect cooling, or a combination of these methods.

[0045] The weight-average molecular weight (Mw) of the polyhydroxypolyether resin of the present invention is 10,000 to 200,000. Here, if Mw is less than 10,000, there is a risk of decreased film-forming properties and mechanical properties (especially strength), which is undesirable. If Mw is greater than 200,000, there is a risk of decreased solvent solubility and compatibility with other resins, which may make the resin difficult to handle, which is also undesirable. Mw is preferably 12,000 to 160,000, more preferably 15,000 to 150,000, and even more preferably 18,000 to 100,000. The Mw of the polyhydroxypolyether resin can be measured by the GPC method described in the examples.

[0046] Furthermore, the present invention relates to a resin composition obtained by blending a curing agent with the above-mentioned polyhydroxypolyether resin, and further to a resin composition that also contains an epoxy resin, wherein the polyhydroxypolyether resin in the solid content is 1% to 99% of the total mass of the resin composition, and the ratio can be adjusted according to the desired properties.

[0047] Furthermore, it is preferable that the curing agent incorporated into the above resin composition is at least one selected from the group consisting of acrylic acid ester resins, melamine resins, urea resins, phenolic resins, acid anhydride compounds, amine compounds, imidazole compounds, amide compounds, cationic polymerization initiators, organophosphines, phosphonium salts, tetraphenylborone salts, hydrazide compounds, boron halide amine complexes, polymercaptan compounds, isocyanate compounds, polyisocyanate compounds, blocked isocyanate compounds, and active ester curing agents.

[0048] The epoxy resins used in the above resin compositions may be publicly known or in use, and new functions such as further improvements in heat resistance and adhesion, as well as improved flame retardancy and dimensional stability, can be imparted. Specifically, examples include epoxy resins obtained by epoxidizing the various difunctional phenols mentioned above, polyfunctional epoxy resins obtained by epoxidizing polyhydric phenolic resins such as phenol novolac, cresol novolac, aralkylphenol resin, and aralkylnaphthol resin, amine-type epoxy resins obtained by epoxidizing amine compounds such as aminophenol, diaminodiphenylmethane, and diaminodiphenylsulfone, alcohol-type epoxy resins obtained by epoxidizing alcohol group-containing compounds such as hexanedimethanol, propylene glycol, cyclohexanedimethanol, trimethylolpropane, and pentaerythritol, ester-type epoxy resins obtained by epoxidizing compounds having carboxyl groups, epoxy resins obtained by oxidation of alkenes, and epoxy resins into which atoms such as bromine and phosphorus have been introduced.

[0049] The resin composition of the present invention may contain a solvent or reactive diluent to appropriately adjust the viscosity of the resin composition during handling when forming a coating film. In the resin composition of the present invention, the solvent or reactive diluent is used to ensure the handling and workability of the resin composition during molding, and there are no particular restrictions on the amount used. In the present invention, the terms "solvent" and "solvent" mentioned above are used to distinguish them according to their form of use, but they may be the same or different.

[0050] Examples of solvents that may be included in the resin composition of the present invention include ketones such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, and cyclohexanone; esters such as ethyl acetate; ethers such as ethylene glycol monomethyl ether; amides such as N,N-dimethylformamide and N,N-dimethylacetamide; alcohols such as methanol and ethanol; alkanes such as hexane and cyclohexane; and aromatics such as toluene and xylene. The solvents listed above may be used individually or mixed in any combination and ratio of two or more.

[0051] 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 glycidylamines.

[0052] These solvents or reactive diluents are preferably used in an amount of 90% by mass or less as nonvolatile content, and the appropriate type and amount are selected as appropriate depending on the application. For example, in printed circuit 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 content. Also, for example, in adhesive film applications, for example, ketones, acetate esters, carbitols, aromatic hydrocarbons, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc., are preferred, and the amount used is preferably 30 to 60% by mass as nonvolatile content.

[0053] The resin composition of the present invention may optionally contain a curing accelerator or a catalyst. Examples of curing accelerators or catalysts include imidazole compounds, tertiary amines, phosphorus compounds such as phosphines, metal compounds, Lewis acids, and amine complex salts. These may be used individually or in combination of two or more.

[0054] The amount of curing accelerator or catalyst added can be appropriately selected depending on the intended use, but 0.01 to 15 parts by mass are used as needed per 100 parts by mass of epoxy resin component in the resin composition. Preferably, it is 0.01 to 10 parts by mass, more preferably 0.05 to 8 parts by mass, even more preferably 0.1 to 5 parts by mass, and particularly preferably 0.1 to 1.0 part by mass. By using a curing accelerator or catalyst, the curing temperature can be lowered and the curing time can be shortened.

[0055] The resin composition of the present invention may use various known flame retardants to improve the flame retardancy of the resulting cured product, provided that reliability is not compromised. Examples of usable flame retardants include halogen-based flame retardants, phosphorus-based flame retardants, nitrogen-based flame retardants, silicone-based flame retardants, inorganic flame retardants, and organometallic salt-based flame retardants. From an environmental standpoint, halogen-free flame retardants are preferred, and phosphorus-based flame retardants are particularly preferred. These flame retardants may be used individually, in combination of two or more flame retardants of the same system, or in combination of flame retardants of different systems.

[0056] The resin composition of the present invention may contain components other than those listed above (which may be 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, UV inhibitors, antioxidants, coupling agents, plasticizers, fluxes, thixotropy-imparting agents, smoothing agents, colorants, pigments, dispersants, emulsifiers, de-elasticizing agents, mold release agents, defoaming agents, ion trapping agents, and the like.

[0057] 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 fibers, glass fibers, alumina fibers, silica-alumina fibers, silicon carbide fibers, polyester fibers, cellulose fibers, aramid fibers, and ceramic fibers; and fine particle rubber.

[0058] The resin composition of the present invention may also contain thermoplastic resins other than the polyhydroxypolyether resin of the present invention. Examples of thermoplastic resins include polyhydroxypolyether 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, polyhydroxypolyether resins other than those of the present invention are preferred.

[0059] Other components include organic pigments such as quinacridone, azo, and phthalocyanine pigments; inorganic pigments such as titanium dioxide, metallic foil pigments, and rust-preventive pigments; ultraviolet absorbers such as hindered amine, benzotriazole, and benzophenone pigments; antioxidants such as hindered phenol, phosphorus, sulfur, and hydrazide pigments; and additives such as mold release agents, leveling agents, rheology control agents, pigment dispersants, anti-repellent agents, and defoaming agents, as well as stearic acid, palmitic acid, zinc stearate, and calcium stearate. The amount of these other components is preferably in the range of 0.01 to 20% by mass relative to the total solid content in the resin composition.

[0060] The resin composition of the present invention is obtained by uniformly mixing the above components. The resin composition of the present invention, which contains the polyhydroxypolyether resin, curing agent, and optionally various other components, can be easily cured in the same manner as conventionally known methods. This cured product exhibits excellent balance of low hygroscopicity, dielectric properties, heat resistance, and adhesion, and shows good cured physical properties. Here, "curing" means intentionally curing the resin composition with heat and / or light, and the degree of curing can be controlled according to the desired physical properties and application. The degree of progression may be fully cured or partially cured, and is not particularly limited, but the reaction rate of the curing reaction between the epoxy group and the curing agent is usually 5 to 95%.

[0061] The resin composition of the present invention can also be applied to various substrates or impregnated into various cloth-like substrates and heated to a semi-cured state to obtain a sheet-like resin composition. Specific examples of substrates include resin films such as polyethylene terephthalate sheets and polyamide sheets, and metal sheets such as copper foil, aluminum foil, and steel sheets. Here, the semi-curing state is not limited, but generally, it should be a semi-cured state (also called stage B) between the compound state (also called stage A) and the cured state (also called stage C).

[0062] Specific examples of cloth-like substrates include those made by weaving various fibrous materials into a cloth shape, such as glass cloth, aramid fiber cloth, fluororesin fiber cloth, and carbon fiber cloth.

[0063] The resin composition of the present invention can be cured in the same way as known epoxy resin compositions to obtain a cured product. Methods for obtaining the cured product can be the same as those for known epoxy resin compositions, and methods such as casting, injection, potting, dipping, drip coating, transfer molding, compression molding, etc., or forming a laminate by laminating the resin in the form of a resin sheet, resin-coated copper foil, prepreg, etc., and then curing it by heating and pressurizing are preferably used.

[0064] The curing temperature is typically in the range of 80 to 300°C, and the curing time is typically around 10 to 360 minutes. This heating is preferably carried out in two stages: primary heating at 80 to 180°C for 10 to 90 minutes, and secondary heating at 120 to 200°C for 60 to 150 minutes. Furthermore, in formulations where the glass transition temperature (Tg) exceeds the secondary heating temperature, it is preferable to perform a tertiary heating at 150 to 280°C for 60 to 120 minutes. Performing such secondary and tertiary heating can reduce curing defects.

[0065] If the curing temperature is high, the large temperature difference with the actual usage temperature can cause internal stress and strain, which may lead to minute deformation of the cured product. It is desirable to select a system that cures at the lowest possible temperature by selecting the curing agent and catalyst. However, lowering the temperature increases the viscosity of the resin composition, which can lead to residual air bubbles and reduced wettability with the adherend, resulting in decreased adhesive strength. This problem can be solved by using the low-viscosity polyhydroxypolyether resin of the present invention.

[0066] The present invention will be described in more detail below based on examples and comparative examples, but the present invention is not limited thereto. Unless otherwise specified, parts represent "parts by mass" and % represents "mass percent". The analytical and measurement methods are shown below.

[0067] (1) Weight-average molecular weight (Mw): Determined by GPC measurement. Specifically, a main unit HLC8320GPC (manufactured by Tosoh Corporation) was used with columns (TSKgel SuperH-H, SuperH2000, SuperHM-H, SuperHM-H, all manufactured by Tosoh Corporation) connected in series, and the column temperature was set to 40°C. Tetrahydrofuran (THF) was used as the eluent at a flow rate of 1.0 mL / min, and a differential refractive index detector was used. The sample to be measured was 0.1 g of solid content dissolved in 10 mL of THF, filtered through a 0.45 μm microfilter, and injected in a volume of 50 μL. Mw was determined by conversion from a calibration curve obtained from standard polystyrene (Tosoh Corporation, PStQuick A, PStQuick B, PStQuick C). Data processing was performed using the GPC8020 Model II version 6.00 (manufactured by Tosoh Corporation).

[0068] (2) IR (Infrared Absorption Spectrum): A Fourier transform infrared spectrophotometer (Perkin Elmer Precisly, Spectrum One FT-IR Spectrometer 1760X) was used, with sodium chloride as the cell. The sample dissolved in chloroform was coated onto the cell, dried, and then measured at wavenumbers of 500 to 4000 cm⁻¹. －１ The transmittance was measured.

[0069] (3) Non-volatile content: Measured in accordance with JIS K7235 standard. The drying temperature was 200°C and the drying time was 60 minutes.

[0070] (4) Solution viscosity The viscosity measurement method was in accordance with JIS Z8803 standard and the single-cylinder rotational viscometer. Specifically, a resin solution adjusted to 30% by weight of non-volatile content was placed in a beaker, and the viscosity was measured at 25°C using a B-type viscometer.

[0071] (5) Glass transition temperature was measured in accordance with IPC-TM-650 2.4.25.c standard. Specifically, a sample with a thickness of 4 mm and a diameter of 3 mm was measured for two cycles in the range of 20 to 280°C using a differential scanning calorimetry system EXSTAR6000 DSC6200 (manufactured by Hitachi High-Tech Science Corporation) under a heating condition of 10°C / min, and the glass transition temperature (Tmg) at the midpoint of the measurement chart obtained from the second scan was used.

[0072] (6) Sulfur content The sulfur was burned according to the method specified in JIS K 2541, absorbed into 0.3 wt% hydrogen peroxide solution to form sulfuric acid, and then measured by ion chromatography. Apparatus: IC20 manufactured by Nippon Dionex Co., Ltd. Column: Anion exchange column IonPac AS14 Suppressor: ASRS-300 Calibration curve: SO2 with known concentration ４ ２－ A mixed standard aqueous solution containing [the substance] was measured and a calibration curve was created. The SO2 was measured using this calibration curve. ４ ２－ The sulfur content was calculated from the amount contained.

[0073] [Bifunctional epoxy resin] E1: 4,4-diphenyl sulfide type epoxy resin obtained in Synthesis Example 1, epoxy equivalent 172 g / eq, m ≈ 0.05

[0074] E2: Dimethyldihydroxy ditertically butyldiphenyl sulfide type epoxy resin (manufactured by Nippon Steel Chemicals Ltd., YSLV-120TE, epoxy equivalent 245 g / eq, m ≈ 0.05)

[0075] E3: Dimethyldiphenyl sulfide type epoxy resin obtained in Synthesis Example 2, epoxy equivalent 183 g / eq, m ≈ 0.05

[0076] E4: 2,5-di-tert-butylhydroquinone diglycidyl ether (manufactured by Nippon Steel Chemical & Material Co., Ltd., YDC-1312, epoxy equivalent 176.0 g / eq)

[0077] E5: Bisphenol A type liquid epoxy resin (manufactured by Nippon Steel Chemical & Material Co., Ltd., YD-128, epoxy equivalent weight 186 g / eq, m ≈ 0.09)

[0078] E6: Tetramethylbiphenol type epoxy resin (Mitsubishi Chemical Corporation, YX-4000, epoxy equivalent 193 g / eq)

[0079] E7: Tetramethylbiphenolsulfone-type epoxy resin obtained in Synthesis Example 3, epoxy equivalent weight 211.4 g / eq

[0080] [Bifunctional phenol compound] P1: 4,4'-dihydroxydiphenyl sulfide (manufactured by Tokyo Chemical Industry Co., Ltd., hydroxyl group equivalent 109 g / eq)

[0081] P2: Dimethyldihydroxy ditertrialybutyldiphenyl sulfide, hydroxyl group equivalent 179 g / eq

[0082] P3: Bisphenol S (manufactured by Tokyo Chemical Industry Co., Ltd., hydroxyl group equivalent 125 g / eq)

[0083] P4: Bisphenol A (manufactured by Nippon Steel Chemical & Material Co., Ltd., hydroxyl group equivalent 114 g / eq)

[0084] P5: Bisphenol TMC (manufactured by Tokyo Chemical Industry Co., Ltd., hydroxyl group equivalent 155 g / eq)

[0085] P6: 9,9-bis(4-hydroxyphenyl)fluorene (manufactured by Tokyo Chemical Industry Co., Ltd., hydroxyl group equivalent 175 g / eq)

[0086] [Hardening agent] H1: Novolac-type phenolic resin (BRG-557, hydroxyl group equivalent 105 g / eq) H2: 2-ethyl-4-methylimidazole (2E4MZ, manufactured by Shikoku Chemicals Co., Ltd.)

[0087] Synthesis Example 1: 130.8 g (0.6 mol) of 4,4'-dihydroxydiphenyl sulfide and 666 g of epichlorohydrin were charged into a 1 L four-necked flask. 97.0 g of 48% sodium hydroxide aqueous solution was added dropwise over 4 hours at 60°C under reduced pressure (approximately 140 mmHg). During this time, water was removed from the system by azeotrope with the epichlorohydrin, and the distilled epichlorohydrin was returned to the system. After the dropwise addition was complete, the reaction was continued for another hour. Subsequently, the excess epichlorohydrin remaining in the system was removed by distillation under reduced pressure and dissolved in 462 ml of methyl isobutyl ketone. The resulting salt was then removed by filtration. Next, 55.8 g of 24% sodium hydroxide aqueous solution was added, and the mixture was reacted at 80°C for 2 hours. After further washing with water and neutralization, the methyl isobutyl ketone was removed by distillation to obtain epoxy resin E1. The epoxy equivalent was 172 g / eq, and the melting point was 43–47°C. Furthermore, the hydrolyzable chlorine content was 450 ppm.

[0088] Synthesis Example 2 The same procedure as in Synthesis Example 1 was carried out, except that 147.6 g (0.6 mol) of 3,3'-dimethyl-4,4'-dihydroxydiphenyl sulfide was used instead of 4,4'-dihydroxydiphenyl sulfide in the same apparatus, to obtain epoxy resin E3. The epoxy equivalent was 183 g / eq, and the melting point was 47-51°C. The hydrolyzable chlorine content was 410 ppm.

[0089] Synthesis Example 3: The same procedure as in Synthesis Example 1 was carried out, except that tetramethyl-4,4'-dihydroxydiphenyl sulfone was used instead of 4,4'-dihydroxydiphenyl sulfide in the same apparatus, to obtain epoxy resin E7. The epoxy equivalent was 211.4 g / eq. The hydrolyzable chlorine content was 410 ppm.

[0090] Examples 1-11: In the same apparatus as in Synthesis Example 1, epoxy resin, difunctional phenol, and cyclohexanone as the reaction solvent were charged in the amounts (solids, parts by mass) shown in Table 1 to a non-volatile content of 90% to 50%. Nitrogen gas was flowed through the apparatus and the temperature was raised to 100°C while stirring. After adding the catalyst, the temperature was raised to 155°C and the reaction was carried out at the same temperature for 7 hours. Cyclohexanone was mixed as a diluent to obtain a polyhydroxypolyether resin varnish with a non-volatile content of 30%. The GPC chart of the weight-average molecular weight of Example 5 is shown in Figure 1. The infrared absorption spectrum of Example 5 is also shown in Figure 2. Table 1 shows the weight-average molecular weight, glass transition temperature, solution viscosity, and sulfur content.

[0091] Comparative Examples 1-4: In the same apparatus as in Synthesis Example 1, epoxy resin, difunctional phenol, and cyclohexanone as a reaction solvent were charged in the amounts (solids, parts by mass) shown in Table 2, with a non-volatile content of 90% to 50%. Nitrogen gas was flowed through the apparatus and the temperature was raised to 100°C while stirring. After adding the catalyst, the temperature was raised to 155°C and the reaction was carried out at the same temperature for 7 hours. Cyclohexanone was mixed as a diluent to obtain a polyhydroxypolyether resin varnish with a non-volatile content of 30%. Table 2 shows the weight-average molecular weight, glass transition temperature, solution viscosity, and sulfur content.

[0092] Examples 12-15, Comparative Examples 5-9 The polyhydroxypolyether resin varnish, epoxy resin E5, and curing agents H1 and H2 obtained in Examples 5-6 and Comparative Examples 1-4 were blended in the amounts shown in Table 3 (expressed as solid content, parts by mass) to obtain resin compositions. These were then applied to an iron plate to a film thickness of 150 μm after drying, and dried in a dryer at 150°C for 1 hour to obtain sheet-like resin compositions. Copper foil (Mitsui Mining & Smelting Co., Ltd., 3EC) was placed on top of the sheet-like resin composition and pressurized for 5 minutes at each temperature. The glass transition temperature of the cured product and the results of the copper foil peel strength are shown in Table 3. In the copper foil peel strength results, those with an adhesive strength of 1 kN or more are indicated with "○", those with an adhesive strength of less than 1 kN are indicated with "×", and those with varying values ​​of less than 1 kN and 1 kN or more are indicated with "△".

[0093]

[0094]

[0095]

[0096] As can be seen in Tables 1 to 3, the polyhydroxypolyether resin of the present invention exhibits excellent high heat resistance, low viscosity, and even superior adhesive strength at low temperatures.

[0097] The polyhydroxypolyether resin and resin composition of the present invention are applicable to a wide range of fields, including adhesives, paints, construction materials for civil engineering, and insulating materials for electrical and electronic components. They are particularly useful as insulating casting materials, laminates, and encapsulating materials in the electrical and electronic field. The polyhydroxypolyether resin and resin composition containing the same can be suitably used in multilayer printed circuit boards, laminates for electrical and electronic circuits such as capacitors, adhesives such as film adhesives and liquid adhesives, semiconductor encapsulating materials, underfill materials, interchip fill materials for 3D-LSIs, insulating sheets, prepregs, heat dissipation substrates, and the like.

Claims

1. A polyhydroxy polyether resin represented by the following general formula (1), having a sulfur content greater than 3% by mass and less than 12% by mass, and a weight average molecular weight of 10,000 to 200,000. (In the formula, each R is independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms or an alkynyl group having 2 to 12 carbon atoms. Each Z is independently a divalent group and has a structure represented by general formula (2), general formula (3) or general formula (4). G is a hydrogen atom or a glycidyl group. n is the number of repetitions and its average value is 5 or more and 1000 or less.) (In the formula, R is the same as in general formula (1). Each X is independently a direct bond, -CH ２ -, -C(CH ３ ) ２ -, -CH(CH ３ )-, -O-, -CO-, -SO ２ -, -S- or shows any one or more structures of general formula (2a). (In the formula, R is the same as in general formula (1). * indicates the bonding position.) (In the formula, R is the same as in general formula (1). * indicates the bonding position.) (In the formula, R is the same as in general formula (1). * indicates the bonding position.) 2. A method for producing a polyhydroxypolyether resin according to claim 1 by reacting a difunctional epoxy resin with a difunctional phenol compound, characterized in that either or both of a difunctional epoxy resin represented by general formula (5) and a difunctional phenol compound represented by general formula (6) are used. (In the formula, R is the same as in general formula (1). m is the number of repetitions, ranging from 0 to 10.) (In the formula, R is the same as in general formula (1).) 3. A resin composition comprising the polyhydroxypolyether resin and a curing agent as described in claim 1.

4. A resin composition comprising the polyhydroxypolyether resin, epoxy resin, and curing agent described in claim 1.

5. A sheet-like resin composition obtained by semi-curing the resin composition according to claim 3 or 4.

6. A cured product obtained by curing the resin composition according to claim 3 or 4.

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