JP2015086296A - Epoxy resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin composition excellent in storage stability and curability.SOLUTION: The epoxy resin composition contains (A) an epoxy resin and (B) a compound represented by general formula (I) (where Rand Reach independently represent an alkyl group or an aryl group; Rrepresents an alkyl group; D represents an oxygen atom or a sulfur atom; X, A, and Z each independently represent an oxygen atom, a sulfur atom, or =N-R; Rrepresents a hydrogen atom, an alkyl group, or an aryl group; and L represents a Lewis base).

Description

  The present invention relates to an epoxy resin composition, and in particular, relates to an epoxy resin composition that is blended with a phosphate and has excellent storage stability and excellent curability.

  Epoxy resins have excellent adhesion to various substrates, and cured products obtained by curing epoxy resins with curing agents have relatively good heat resistance, chemical resistance, electrical properties, mechanical properties, etc. Therefore, it is used in a wide range of applications such as paints, adhesives, and various molding materials.

  Conventionally, epoxy resin compositions have been mainly two-component systems in which a curing agent or a curing accelerator is added immediately before use. The two-component system has the characteristics that it can be cured at room temperature or low temperature, but on the other hand, it must be weighed and mixed immediately before use, and the pot life is short, so it can be applied to automatic machines. It has a drawback that its use conditions are limited such as difficulty. In order to solve such problems, a one-component curable epoxy resin composition is desired.

  In order to obtain such a one-component curable resin composition, a curing agent that does not react at room temperature but has a property of starting and curing by heating, a so-called latent curing agent is required. As the latent curing agent, for example, dicyandiamide, dibasic acid dihydrazide, boron trifluoride amine complex salt, guanamines, melamine, imidazoles and the like have been proposed. However, for example, a mixture of dicyandiamide, melamine, and guanamines with an epoxy resin is excellent in storage stability, but has a drawback of requiring high-temperature and long-time curing conditions of 150 ° C. or higher. Moreover, although these and a hardening accelerator are used together and shortening hardening time is also performed widely, the fault that storage stability will be impaired remarkably will arise. On the other hand, dibasic acid dihydrazide and imidazoles cure at a relatively low temperature, but have poor storage stability. Boron trifluoride amine complex salt has the advantages of excellent storage stability and short curing time, but has disadvantages such as poor water resistance and corrosiveness to metals.

  In addition, for example, Patent Document 1, Patent Document 2, Patent Document 3, Patent Document 4, and the like have proposed the use of Lewis base salts as curing agents or curing catalysts for epoxy resins. A product with an excellent balance of sex has not been obtained.

JP-A-7-304857 JP-A-9-202831 JP 2008-19350 A JP 2012-12431 A

  Accordingly, an object of the present invention is to provide an epoxy resin composition having excellent storage stability and excellent curability.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a specific phosphate exhibits an effect as an epoxy resin curing agent or a curing accelerator, and can achieve the above object. The invention has been reached.

  That is, the present invention provides an epoxy resin composition comprising (A) an epoxy resin and (B) a compound represented by the general formula (I).

（式中、Ｒ¹及びＲ²はそれぞれ独立してアルキル基又はアリール基を表し、Ｒ³はアルキル基を表し、Ｄは酸素原子又は硫黄原子を表し、Ｘ、Ａ及びＺはそれぞれ独立して酸素原子、硫黄原子又は＝Ｎ−Ｒ⁴を表し、Ｒ⁴は、水素原子、アルキル基又はアリール基を表し、Ｌはルイス塩基を表す。）

(In the formula, R ¹ and R ² each independently represents an alkyl group or an aryl group, R ³ represents an alkyl group, D represents an oxygen atom or a sulfur atom, and X, A, and Z each independently represent An oxygen atom, a sulfur atom or ═N—R ⁴ , R ⁴ represents a hydrogen atom, an alkyl group or an aryl group, and L represents a Lewis base.)

  According to the present invention, a practical resin composition having an easily available raw material as a constituent element and having a balance between appropriate curing characteristics and storage stability can be obtained. In particular, by using a one-component resin composition that does not contain a curable resin component that is solid at room temperature, it is possible to provide a one-component resin composition that is excellent in workability and suitable for narrow space adhesion and impregnation adhesion. It was.

Hereinafter, the epoxy resin composition of the present invention will be described in detail.
First, the epoxy resin as the component (A) will be described.

  Examples of the epoxy resin that is the component (A) used in the present invention include polyglycidyl ether compounds of mononuclear polyhydric phenol compounds such as hydroquinone, resorcin, pyrocatechol, and phloroglucinol; dihydroxynaphthalene, biphenol, methylene Bisphenol (bisphenol F), methylene bis (orthocresol), ethylidene bisphenol, isopropylidene bisphenol (bisphenol A), isopropylidene bis (orthocresol), tetrabromobisphenol A, 1,3-bis (4-hydroxycumylbenzene), 1,4-bis (4-hydroxycumylbenzene), 1,1,3-tris (4-hydroxyphenyl) butane, 1,1,2,2-tetra (4-hydroxyphenyl) ethane, thiobisphenol Polyglycidyl ether compounds of polynuclear polyhydric phenol compounds such as alcohol, sulfonyl bisphenol, oxybisphenol, phenol novolak, orthocresol novolak, ethylphenol novolak, butylphenol novolak, octylphenol novolak, resorcin novolak, terpene phenol; ethylene glycol, propylene glycol , Butylene glycol, hexanediol, polyglycol, thiodiglycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, polyglycidyl ethers of polyhydric alcohols such as bisphenol A-ethylene oxide adduct; maleic acid, fumaric acid, itaconic acid , Succinic acid, glutaric acid, suberic acid, adipic acid, azelaic acid, sebacic acid Aliphatic, aromatic or alicyclic such as dimer acid, trimer acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, trimesic acid, pyromellitic acid, tetrahydrophthalic acid, hexahydrophthalic acid, endomethylenetetrahydrophthalic acid Homopolymers or copolymers of glycidyl esters of polybasic acids and glycidyl methacrylate; N, N-diglycidylaniline, bis (4- (N-methyl-N-glycidylamino) phenyl) methane, diglycidyl orthotoluidine Epoxy compounds having a glycidylamino group such as vinylcyclohexene diepoxide, dicyclopentanediene diepoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-6-methylcyclohexyl Epoxidation products of cyclic olefin compounds such as methyl-6-methylcyclohexanecarboxylate and bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate; Epoxidation conjugates such as epoxidized polybutadiene and epoxidized styrene-butadiene copolymer Examples thereof include heterocyclic compounds such as diene polymers and triglycidyl isocyanurate. In addition, these epoxy resins may be those internally crosslinked by a prepolymer of a terminal isocyanate or those having a high molecular weight with a polyvalent active hydrogen compound (polyhydric phenol, polyamine, carbonyl group-containing compound, polyphosphate ester, etc.). .

The (A) epoxy resin preferably has an epoxy equivalent of 70 to 3000, more preferably 90 to 2000. If the epoxy equivalent is less than 70, the physical properties of the cured product may be lowered, and if it is greater than 3000, sufficient curability may not be obtained.
Next, the compound represented by the general formula (I) as the component (B) will be described.

In the general formula (I), the alkyl groups represented by R ¹ and R ² are each independently methyl, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tertiary butyl group, amyl Group, isoamyl group, tertiary amyl group, hexyl group, isohexyl group, octyl group, 2-ethylhexyl group, tertiary octyl group, nonyl group, decyl group and other alkyl groups having 1 to 10 carbon atoms, and the like. the aryl group represented by R ¹ and R ^2, for example, a phenyl group, a naphthyl group, nonylphenyl group, an aryl group having a carbon number of 4 to 15, such as a furanyl group (furan ring) can be mentioned, R ³ As the alkyl group represented by, for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, amyl group, isoamyl group, tert-amyl group And alkyl groups having 1 to 10 carbon atoms such as a group, hexyl group, isohexyl group, octyl group, 2-ethylhexyl group, tertiary octyl group, nonyl group and decyl group.
When X, A or Z is ═N—R ⁴ , the alkyl group and aryl group represented by R ⁴ are the same as those exemplified as the alkyl group and aryl group represented by R ¹ and R ² , respectively. Groups.
In the general formula (I), examples of the Lewis base represented by L include pyridine and derivatives thereof, imidazole and derivatives thereof, pyrazole and derivatives thereof, triazole and derivatives thereof, tertiary amines such as triethylamine, DBU and the like. Examples thereof include trivalent phosphines such as amidines and triphenylphosphine.

Among the compounds represented by the general formula (I) as the component (B), a compound in which one or both of R ¹ and R ² is an aryl group is preferable from the viewpoint of reactivity with an epoxy resin, The compounds in which D and X, A, and Z are oxygen atoms are preferred because of the availability of raw materials.
A compound in which R ³ is a linear alkyl group is preferred from the viewpoint of synthesis.

  As a method for producing the phosphorus-containing compound represented by the general formula (I) used in the present invention, for example, it can be produced by the following reaction formula.

（式中、Ｒ¹、Ｒ²、Ｒ³、Ｄ、Ｘ、Ａ、Ｚ及びＬは前記一般式（Ｉ）と同義である。）

(In the formula, R ¹ , R ² , R ³ , D, X, A, Z and L have the same meanings as in the general formula (I).

  In the above reaction, a solvent can also be used. Examples of the solvent include ketones such as methyl ethyl ketone, methyl amyl ketone, diethyl ketone, acetone, methyl isopropyl ketone, propylene glycol monomethyl ether acetate and cyclohexanone; tetrahydrofuran, 1,2-dimethoxyethane, 1,2-diethoxyethane. Ethers such as ethyl acetate and n-butyl acetate; Amides such as N, N-dimethylformamide, N, N-dimethylacetamide and N-methylpyrrolidone; Aromatic carbonization such as benzene, toluene and xylene Hydrogen; Terpene hydrocarbon oils such as turpentine oil, D-limonene and pinene; Paraffinic solvents such as mineral spirit, Swazol # 310 (Cosmo Matsuyama Oil Co., Ltd.), Solvesso # 100 (Exxon Chemical Co., Ltd.); Carbon chloride, chloroform, tri Halogenated aliphatic hydrocarbons such as chloroethylene and methylene chloride; halogenated aromatic hydrocarbons such as chlorobenzene; dioxane, acetonitrile, carbon disulfide, dimethyl sulfoxide, N, N′-dimethylimidazolidinone and the like.

  These reactions can be carried out at 0 to 250 ° C., preferably at room temperature to 200 ° C., for 0.5 hour to 72 hours, preferably 1 hour to 24 hours.

  In the epoxy resin composition of the present invention, 0.001 to 50 parts by mass, preferably 0.01 to 50 parts by mass of the compound represented by (B) general formula (I) with respect to 100 parts by mass of (A) epoxy resin. 20 parts by weight are used.

  In the epoxy resin composition of the present invention, the compound represented by the general formula (I) as the component (B) acts as an epoxy resin curing agent, but (C) the general formula (I) An epoxy resin curing agent other than the represented compound can be used in combination.

  Here, for example, when polycarboxylic acid anhydride, polyhydric phenol or the like is used in combination as a curing agent, the component (B) also functions as a curing catalyst for these curing agents.

  Examples of the polyhydric phenol include dihydroxyphenol, biphenol, bisphenol, halogenated biphenol, halogenated bisphenol, alkylated biphenol, alkylated bisphenol, trisphenol, phenol-aldehyde novolak resin, substituted phenol aldehyde novolak resin, and phenol-carbonized. Compounds having an average of more than one aromatic hydroxyl group per molecule, such as hydrogen resins, substituted phenol-hydrocarbon resins and any combinations thereof; Hydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, hydrogenated methyl nadic anhydride, phthalic anhydride, trimetic anhydride, anhydrous Etc. Romerritto acid, and the like.

  In addition, a general-purpose epoxy resin curing agent can be used in combination, and examples of the epoxy resin curing agent include 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 1- (2-methylimidazole-1 -Imidyl) imidazoles such as naphthalen-2-ol; polyalkylpolyamines such as diethylenetriamine, triethylenetriamine, tetraethylenepentamine; 1,2-diaminocyclohexane, 1,4-diamino-3,6-diethylcyclohexane, And alicyclic polyamines such as isophoronediamine; aromatic polyamines such as m-xylylenediamine, diaminodiphenylmethane, and diaminodiphenylsulfone. In addition, these polyamines and glycidyl ethers such as phenyl glycidyl ether, butyl glycidyl ether, bisphenol A-diglycidyl ether, bisphenol F-diglycidyl ether, or various epoxy resins such as glycidyl esters of carboxylic acid are used in a conventional manner. A polyepoxy addition modification product produced by reacting with a carboxylic acid such as phthalic acid, isophthalic acid, dimer acid, etc. by an ordinary method; These polyamines and aldehydes such as formaldehyde and phenols having at least one aldehyde-reactive site in the nucleus such as phenol, cresol, xylenol, tert-butylphenol, and resorcin are prepared by a conventional method. Mannich-modified products, etc. which is produced by response and the like. Furthermore, latent curing agents such as dicyandiamide and imidazoles can also be used.

  In the epoxy resin composition of the present invention, when an epoxy resin curing agent other than the compound represented by the general formula (I) as the component (C) is used in combination, the amount used is the amount used of the component (B). Although it determines suitably, it is preferably 20-100 mass parts with respect to 100 mass parts of (A) epoxy resin, More preferably, it is 50-80 mass parts.

In the epoxy resin composition of the present invention, if necessary, a curing catalyst; a reactive or non-reactive diluent (plasticizer) such as monoglycidyl ethers, dioctyl phthalate, dibutyl phthalate, benzyl alcohol, coal tar, etc .; glass Fillers or pigments such as fiber, carbon fiber, cellulose, silica sand, cement, kaolin, clay, aluminum hydroxide, bentonite, talc, silica, fine powder silica, titanium dioxide, carbon black, graphite, iron oxide, bitumen substance; γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -N′-β- (aminoethyl) -γ-aminopropyltriethoxy Silane, γ-anilinopropyltriethoxysilane, γ-glycidoxypro Lutriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, vinyltriethoxysilane, N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltriethoxysilane, γ-methacryloxypropyl Silane coupling agents such as trimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane; candelilla wax, carnauba wax, wood wax, ibota wax, beeswax, lanolin, whale wax, montan wax, petroleum Lubricants such as waxes, fatty acid waxes, fatty acid esters, fatty acid ethers, aromatic esters, aromatic ethers; thickeners; thixotropic agents; antioxidants; light stabilizers; ultraviolet absorbers; Rust preventive agent; colloidal silica, colloidal Conventional additives such as rualumina may be contained, and adhesive resins such as xylene resin and petroleum resin may be used in combination.
The usage-amount of these arbitrary additives in the epoxy resin composition of this invention is suitably determined in the range which does not impair the effect of this invention.

  The epoxy resin composition of the present invention is, for example, a paint or adhesive for concrete, cement mortar, various metals, leather, glass, rubber, plastic, wood, cloth, paper, etc .; adhesive tape for packaging, adhesive label, frozen food label , Removable labels, POS labels, adhesive wallpaper, adhesives for adhesive flooring; processed paper such as art paper, lightweight coated paper, cast coated paper, coated paperboard, carbonless copying machine, impregnated paper; natural fiber, synthetic fiber, Fiber treatment agents such as glass fibers, carbon fibers, metal fibers, etc., fraying prevention agents, processing agents, etc .; building materials such as sealing materials, cement admixtures, waterproofing materials; a wide range of sealing agents for electronic and electrical equipment, etc. Can be used for various purposes.

  Next, the present invention will be described in more detail with reference to production examples and examples, but the present invention is not limited to these production examples and examples.

[Production Example 1]
A 100 mL three-necked flask equipped with a rotor, a reflux tube and a septum is thoroughly dried and purged with nitrogen, and methanol, triethylamine and dehydrated tetrahydrofuran are charged with a syringe, and the reaction temperature of the diphenyl chlorophosphate is 30 ° C. while stirring the solution. It was dripped slowly so as not to exceed. After completion of dropping, the mixture was stirred overnight. Saturated ammonium chloride solution (5 mL) and water (5 mL) were added to the reaction solution and stirred well. The solution was transferred to a separatory funnel and extracted three times with ethyl acetate (10 mL) to obtain an organic layer. The organic layer was washed with water (10 mL), dried over anhydrous magnesium sulfate, and then the solvent was removed by an evaporator to obtain a colorless liquid (crude yield: 81.2%, GC purity: 97.9%). The crude product was purified by column chromatography (stationary phase: silica gel, mobile phase: ethyl acetate / n-hexane (1 vol / 2 vol), Rf = 0.31) and diphenylmonomethyl phosphate (colorless liquid, total yield: 70) 0.5%, GC purity> 99%, ³¹ P-NMR: 10.97 ppm).

A 30 mL round bottom flask equipped with a rotor and a reflux tube was charged with the diphenylmonomethyl phosphoric acid and DMAP prepared above and stirred at 100 ° C. for 2 hours in a nitrogen atmosphere. After cooling to room temperature, the following sample B was obtained (white solid, yield: 98.9%, NMR purity> 99%, ³¹ P-NMR: −9.96 ppm).

[Example 1]
Using the sample B obtained above, the curability and storage stability were examined by the following method.

(Curable)
Sample B was mixed with Adeka Resin EP-4100E (bisphenol A type epoxy resin manufactured by ADEKA Corporation, epoxy equivalent 900) and heated at 180 ° C. for 1 hour and then at 230 ° C. for 3 hours. I got a thing.

(Storage stability)
A mixture of Adeka Resin EP-4100E and Adekaglycyl ED-509S (p-tert-butylphenyl glycidyl ether manufactured by ADEKA, Inc., epoxy equivalent 180) in a mass ratio of 9/1 was mixed with 10 mol% of Sample B at room temperature. The liquid was colorless and transparent and fluid.

Claims (5)

An epoxy resin composition comprising (A) an epoxy resin and (B) a compound represented by the following general formula (I).

(In the formula, R ¹ and R ² each independently represents an alkyl group or an aryl group, R ³ represents an alkyl group, D represents an oxygen atom or a sulfur atom, and X, A, and Z each independently represent An oxygen atom, a sulfur atom or ═N—R ⁴ , R ⁴ represents a hydrogen atom, an alkyl group or an aryl group, and L represents a Lewis base.)   The epoxy resin composition according to claim 1, comprising a compound in which D and X, A, and Z are oxygen atoms in the general formula (I). The epoxy resin composition according to claim 1 or 2, comprising a compound in which either one or both of R ¹ and R ² is an aryl group in the general formula (I).   The epoxy resin composition according to any one of claims 1 to 3, further comprising (C) an epoxy resin curing agent other than the compound represented by the general formula (I).   The epoxy resin composition according to claim 4, wherein the epoxy resin curing agent as the component (C) is at least one selected from polycarboxylic acid anhydrides and polyhydric phenols.