JPH0457689B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a curable epoxy resin composition. More specifically, the present invention relates to a one-component curable epoxy resin composition that has good storage stability at room temperature, is easily cured at temperatures of 80° C. or higher, and has excellent physical properties of the cured product. [Prior art and problems] Conventional latent one-component curing systems employ imidazoles, dicyandiamide, melamine, diaminodiphenylsulfone, hydrazides, boron trifluoride, guanamine, etc. as curing agents and catalysts. Although known and put into practical use, epoxy resins have insufficient storage stability, require long-term curing at high temperatures of 150°C or higher, are hygroscopic, and epoxy resins containing acid anhydrides. Although the composition has relatively good storage stability at room temperature, it has the disadvantage that it requires heating at a considerably high temperature and for a long time upon curing. Therefore, a method of shortening the curing speed is usually used in combination with a curing accelerator such as a tertiary amine, quaternary ammonium salt, or organic metal salt in a system containing an acid anhydride as a curing agent. Although curability is improved by adding a curing accelerator, there is a drawback that storage stability is significantly impaired. Therefore, the composition contains an acid anhydride curing agent that exhibits good storage stability at room temperature, and also cures quickly when heated, has good mechanical properties, and is suitable for electrical installations.
There is a strong desire for a one-component curable epoxy resin composition that has chemical resistance and is easy to handle. In response to the above-mentioned needs, an object of the present invention is to have a compound containing an acid anhydride curing agent, which has room temperature storage stability, and which cures quickly at a relatively low temperature when curing, and which improves the physical properties of the cured product. An object of the present invention is to provide an excellent one-component curable epoxy resin composition. The curable epoxy resin composition of the present invention comprises, as essential components, () an epoxy resin having an average of more than one adjacent epoxy group in the molecule; ()(a) a general formula (In the formula, R ₁ and R ₂ are alkyl groups having 1 or more carbon atoms,
(X is an alkylene group having 1 to 5 carbon atoms) and an epoxy resin having an average of more than one adjacent epoxy group in the molecule, per equivalent of the amino group of the amino compound,
(b) reacting the epoxy-amine adduct obtained by reacting the epoxy groups of the epoxy resin at a ratio of 0.8 to 2.5 equivalents with one or more compounds selected from the group consisting of phenolic resins and polyvalent phenol compounds; and () an acid anhydride curing agent. Here, the preferred epoxy resin () is the formula (where Z is a hydrogen atom, a methyl group, or an ethyl group) Epoxy resin (-1) having an average of more than one substituted or unsubstituted glycidyl ether group in the molecule, the formula (where Z is a hydrogen atom, a methyl group, or an ethyl group) Epoxy resin (-2) having an average of more than one substituted or unsubstituted glycidyl ester group in the molecule, the formula (Here, Z is a hydrogen atom, a methyl group, or an ethyl group) Epoxy resins (-3) that have an average of more than one N-substituted or unsubstituted 1,2-epoxypropyl group in the molecule are included. It will be done. Particularly preferred epoxy resins are those having an epoxy equivalent of 180 to 500. Epoxy resin (-
1) is an epoxy resin obtained by glycidyl etherification of a phenolic hydroxyl group and an epoxy resin obtained by glycidyl etherification of an alcoholic hydroxyl group, and preferable examples of such epoxy resin (-1) include 1
polyglycidyl ether (-1-1) of a multivalent phenol having one or more aromatic nuclei; a polyglycidyl ether (-1-1) of a multivalent phenol having one or two aromatic nuclei; and an alkylene oxide having 2 to 4 carbon atoms; Polyglycidyl ethers of alcoholic polyhydroxyl compounds derived by the addition reaction of
-1-2), etc. However, polyglycidyl ether (-1-
1) means, for example, that a polyhydric phenol (A) having at least one aromatic nucleus and an epihalohydrin (b) are mixed in a conventional manner in the presence of a reaction amount of a basic catalyst or basic compound such as sodium hydroxide. An epoxy resin containing polyglycidyl ether as a main reaction product, as obtained by reacting a polyhydric phenol (A) having at least one aromatic nucleus, and an epihalohydrin (b) in an amount of an acidic catalyst such as boron trifluoride. An epoxy resin such as that obtained by reacting a polyhalohydrin ether obtained by a conventional method with a basic compound such as sodium hydroxide in the presence of a polyvalent phenol having at least one aromatic nucleus ( A polyhalohydrin ether obtained by reacting A) and epihalohydrin (b) in the presence of a catalytic amount of a basic catalyst such as triethylamine in a conventional manner with a basic compound such as sodium hydroxide. It is an epoxy resin like this. Similarly, polyglycidyl ether (-1-2) is a polyhydroxyl compound (B ) and epihalohydrin (b) by a conventional method in the presence of an acidic catalyst amount such as boron trifluoride, and a polyhalohydrin ether obtained by reacting with a basic compound such as sodium hydroxide. It is an epoxy resin containing polyglycidyl ether as the main reaction product. Here, the polyvalent phenol (A) having at least one aromatic nucleus includes a mononuclear polyvalent phenol (A-1) having one aromatic nucleus and a polyvalent phenol having two or more aromatic nuclei. There is phenol (A-2). Examples of such mononuclear polyvalent phenols (A-1) include resorcinol, hydroquinone,
Pyrocatechol, phloroglycinol, 1,5
-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, and the like. In addition, as an example of the polynuclear polyvalent ferol (A-2), the general formula (In the formula, Ar is an aromatic divalent carbon hydrogen group such as a naphthylene group and a phenylene group, and a phenylene group is preferable for the purpose of the present invention. Y′ and Y ₁ may be the same or different, and a methyl group, n -propyl group, n
- an alkyl group, preferably with up to 4 carbon atoms, such as butyl, n-hexyl, n-octyl, or a halogen atom, i.e. chlorine, bromine, iodine or fluorine, or a methoxy group, methoxy Alkoxy groups such as methyl, ethoxy, ethoxyethyl, n-butoxy, amyloxy are preferably alkoxy groups having up to 4 carbon atoms. When a substituent other than a hydroxyl group is present on either or both of the above-mentioned aromatic divalent hydrocarbon groups, these substituents may be the same or different. m and z are integers having values ranging from 0 (zero) to the maximum value corresponding to the number of hydrogen atoms in the aromatic ring (Ar) that can be substituted with a substituent, and can be the same or different values. R ₁ is for example

[Formula] -O-, -S-, -SO-, -SO ₂ -, or alkylene such as methylene group, ethylene group, trimethylene group, tetramethylene group, pentamethylene group, hexamethylene group, 2-ethylhexamethylene group , an octamethylene group, a nonamethylene group, a decamethylene group or an alkylidene group such as an ethylidene group, a propylidene group, an isopropylidene group, an isobutylidene group, an amylidene group, an isoamylidene group, a 1-phenylethylidene group or a cycloaliphatic group such as 1,4 -cyclohexylene group,
1,3-cyclohexylene group, cyclohexylidene group, halogenated alkylene group, halogenated alkylidene group, halogenated cycloaliphatic group, alkoxy- and aryloxy-substituted alkylidene group, or alkoxy-substituted alkylidene group and aryloxy-based alkylene groups or alkoxy- and aryloxy-
Substituted cycloaliphatic groups such as methoxymethylene group, ethoxymethylene group, ethoxyethylene group,
2-ethoxytrimethylene group, 3-ethoxypentamethylene group, 1,4-(2-methoxycyclohexane) group, phenoxyethylene group, 2-phenoxytrimethylene group, 1,3-(2-wenoxycyclohexane) ) or alkylene groups such as phenylethylene group, 2-phenyltrimethylene group, 1,7-phenylpentamethylene group, 2-phenyldecamethylene group or aromatic groups such as phenylene group, naphthylene group or halogenated Aromatic groups such as 1,4-(2-chlorophenylene)
groups, 1,4-(2-fluorophenylene) groups or alkoxy- and aryloxy-substituted aromatic groups such as 1,4-(2-methoxyphenylene)
group, 1,4-(2-ethoxyphenylene) group, 1,
4-(2-n-propoxyphenylene) group, 1,
4-2-phenoxyphenylene) group or an alkyl-substituted aromatic group such as 1,4-(2-methylphenylene) group, 1,4-(2-ethylphenylene) group, 1,4-(2-n -propylphenylene)1,4-(2-n-butylphenylene) group,
It is a divalent group such as a divalent hydrocarbon group such as 1,4-(2-n-dodecylphenylene) group, or
R ₁ is for example the formula It can also be a ring fused to one of the Ar groups, as in the case of the compound represented by R ₁
can also be a polyalkoxy group, such as a polyethoxy group, a polypropoxy group, a polythioethoxy group, a polybutoxy group, a polyphenylethoxy group, or R ₁ can be, for example, a polydimethylsiloxy group,
It can be a group containing a silicon atom, such as a polydiphenylsiloxy group, a polymethylphenylsiloxy group, or R ₁ can be an aromatic ring, a tertiary-amino group, an ether bond, a carbonyl group, or a sulfur or sulfoxide group. There are polynuclear dihydric phenols represented by two or more alkylene groups or ha-alkylidene groups separated by a bond containing a radical. Particularly preferred among such polynuclear divalent phenols is the general formula (In the formula, Y' and Y ₁ have the same meanings as above, m and z have values of 0 to 4, and R ₁ preferably has a value of 1 to 4.
alkylene or alkylidene group or formula with 3 carbon atoms

【formula】

[Formula] or It is a polynuclear divalent phenol represented by ). Examples of such dihydric phenols include 2,2-bis-(p-
hydroxyphenyl)-propane, 2,4-dihydroxydiphenylmethane, bis-(2-hydroxyphenyl)-methane, bis-(4-hydroxyphenyl)-methane, bis-(4-hydroxy-
2,6-dimethyl-3-methoxyphenyl)-methane, 1,1-bis-(4-hydroxyphenyl)
-ethane, 1,2-bis-(4-hydroxyphenyl)-ethane, 1,1-bis-(4-hydroxy-2-chlorophenyl)-ethane, 1,1-bis-(3,5-dimethyl- 4-hydroxyphenyl)
-ethane, 1,3-bis-(3-methyl-4-hydroxyphenyl)-propane, 2,2-bis(3,5-dichloro-4-hydroxyphenyl)-
Propane, 2,2-bis(3-phenyl-4-hydroxyphenyl)-propane, 2,2-bis-
(3-isopropyl-4-hydroxyphenyl)-
Propane, 2,2-bis-(2-isopropyl-
4-hydroxyphenyl)-propane, 2,2-
bis-(4-hydroxynaphthyl)-propane,
2,2-bis-(4-hydroxyphenyl)-pentane, 3,3-bis-(4-hydroxyphenyl)
-pentane, 2,2-bis-(4-hydroxy-
phenyl)-heptane, bis-(4-hydroxyphenyl)methane, bis-(4-hydroxyphenyl)-cyclohexylmethane, 1,2-bis(4
-hydroxyphenyl)-1,2-bis-(phenyl)-propane, 2,2-bis-(4-hydroxyphenyl)-1-phenylpropane, etc.
(Hydroxyphenyl)alkane or 4,4'-
Dihydroxybiphenyl, 2,2'-dihydroxybiphenyl Dihydroxybiphenyl such as 2,4'-dihydroxybiphenyl or bis-(4-hydroxyphenyl)-sulfone, 2,4'-dihydroxydiphenylsulfone, chlor -2,4-dihydroxydifersulfone, 5-chloro-4,
di-(hydroxyphenyl)-sulfones or bis-(4-hydroxyphenyl)-ethers, such as 4'-dihydroxydiphenylsulfone, 3'-chloro-4,4'-dihydroxydiphenylsulfone, 4,
3'-(or 4,2'- or 2,2'-dihydroxy-diphenyl)ether, 4,4'-dihydroxy-
2,6-dimethyl diphenyl ether, bis-
(4-hydroxy-3-isobutylphenyl)-ether, bis-(4-hydroxy-3-isopropylphenyl)-ether, bis-(4-hydroxy-3-chlorophenyl)-ether, bis-(4-hydroxy-3-isobutylphenyl)-ether,
-hydroxy-3-fluorophenyl)-ether,
Bis-(4-hydroxy-3-bromphenyl)-
ether, bis-(4-hydroxynaphthyl)-ether, bis-(4-hydroxy-3-chlornaphthyl)-ether, bis-(2-hydroxybiphenyl)-ether, 4-4'-dihydroxy-2,
6-dimethoxy-diphenyl ether, 4,4'-
Includes di-(hydroxyphenyl)-ethers such as dihydroxy-2,5-diethoxydiphenyl ether, and also 1,1-bis-(4-hydroxyphenyl)-2-phenyl)-2-phenylethane. , 1,3,3-trimethyl-1-(4-hydroxyphenyl)-6-hydroxyindan, 2,
4-bis-(p-hydroxyphenyl)-4-methylpentane is also suitable. Furthermore, another preferred group of such polynuclear divalent phenols has the general formula (where R ₃ is a methyl or ethyl group, R ₂ is an alkylidene group having 1 to 9 carbon atoms or other alkylylene group, and p is 0 to 4), for example, 1,4-bis-(4 −
hydroxybenzyl)-benzene, 1,4-bis-(4-hydroxybenzyl)-tetramethylbenzene, 1,4-bis-(4-hydroxybenzyl)
-tetraethylbenzene, 1,4-bis-(p-
Examples thereof include hydroxychloromyl)-benzene, 1,3-bis(p-hydroxychlormyl)-benzene, and the like. Other polynuclear polyhydric phenols (A-2) include, for example, initial condensates of phenols and carbonyl compounds (e.g., initial condensates of phenolic resins, condensation reaction products of phenols and acrolein, phenol condensation reaction products of phenol and glyoxal, condensation reaction products of phenol and pentanediallyl, condensation reaction products of resorcinol and acetone, xylene-phenol-formalin initial condensate), condensation products of phenols and polychloromethylated aromatic compounds Examples include condensation products of phenol and bischloromethylxylene. Here, the polyhydroxyl compound (B) is a catalyst that promotes the reaction between the above-mentioned polyhydric phenol (A) having at least one aromatic nucleus and an alkylene oxide between an OH group and an epoxy group. -ROH (where R
is an alkylene group derived from alkylene oxide) or (and) -(OR) _o H (where R is an alkylene group derived from alkylene oxide and one polyoxyalkylene chain may contain different alkylene groups, n is a compound having an atomic group (2 or an integer of 2 or more indicating the number of polymerized oxyalkylene groups). In this case, the polyhydric phenol (A)
The ratio of alkylene oxide to the OH group of the polyhydric phenol (A) is preferably 1:10 or more, preferably 1:1 to 3. (equivalent: equivalent). Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, etc., but those that generate side chains when reacting with the polyvalent ferol (A) to form an ether bond are particularly preferred; Examples include propylene oxide, 1,2-butylene oxide, and 2,3-butylene oxide, with propylene oxide being particularly preferred. A particularly preferred group of such polyhydroxyl compounds has the general formula (In the formula, Y′, Y ₁ , m, z and R ₁ are the same as in (1-1) above.
It is a polyhydroxyl compound represented by the formula (R is an alkylene group having 2 to 4 carbon atoms, and n1 and n2 have a value of 1 to 3). Furthermore, another preferred group of such polyhydroxyl compounds has the general formula (In the formula, R ₁ , R ₂ , and R ₃ are the same as those in the above formula (1-2), R is an alkylene group having 2 to 4 carbon atoms, and n1 and n2 have values of 1 to 3.) This is a polyhydroxyl compound represented by the following formula. Also, here epihalohydrin (b) has the general formula (Here, Z is a hydrogen atom, a methyl group, an ethyl group,
Examples of such epihalohydrin (b) include epichlorohydrin, epipromhydrin, 1,2-epoxy-2-methyl-3-chloropropane, and 1,2-epoxy-2-methyl-3-chloropropane. -Epoxy-2
-ethyl-3-chloropropane and the like. Examples of acidic catalysts that promote the reaction between the epihalohydrin (b) and the polyhydric phenol (A) or polyhydroxyl compound (B) include boron trifluoride, tin chloride,
Lewis acids such as zinc chloride and ferric chloride, derivatives exhibiting these activities (eg boron trifluoride-ether chain compounds), or mixtures thereof can be used. Similarly, epihalohydrin (b) and polyphenol
Basic catalysts that promote the reaction with (A) include alkali metal hydroxides (e.g., sodium hydroxide), alkali metal alcoholates (e.g., sodium ethylate), tertiary amine compounds (e.g., triethylamine, ethanolamine), quaternary ammonium compounds (e.g., tetramethylmammonium bumide), or mixtures thereof, such that either the glycidyl ether is formed simultaneously with the reaction or the halo formed as a result of the reaction. Basic compounds that generate glycidyl ether by ring-closing hydrin ether through a dehydrohalogenation reaction include alkali metal hydroxides (e.g., sodium hydroxide), alkali metal aluminates (e.g., aluminate sodium) etc. are conveniently used. Of course, these catalysts and basic compounds can be used as they are or as appropriate inorganic and/or organic solvents. Epoxy resins (1-2) having an average of more than one substituted or unsubstituted glycidyl ester group in the molecule include polyglycidyl esters of aliphatic polycarboxylic acids or aromatic polycarboxylic acids, For example, epoxy resins such as those obtained by polymerizing glycidyl methacrylate synthesized from epihalohydrin (b) represented by the general formula (2) and methacrylic acid are also included. Examples of epoxy resins (1-3) having more than one N-substituted or unsubstituted 1,2-epoxypropyl group in the molecule include aromatic amines (e.g. aniline or alkyl substituents in the nucleus). epoxy resin obtained from the epihalohydrin (b) represented by the above general formula (2), the initial condensation of an aromatic amine and an aldehyde (e.g. aniline-formaldehyde initial condensate, aniline-formaldehyde initial condensate, aniline-formaldehyde initial condensate,
Examples include epoxy resins obtained from phenol-formaldehyde initial condensate) and epihalohydrin (b). In addition, conventionally known epoxy resins such as the various epoxy resins described in "Manufacture and Application of Epoxy Resins" (edited by Hiroshi Kakiuchi) may be used. General formula used in the present invention (In the formula, R ₁ and R ₂ are alkyl groups having 1 to 5 carbon atoms,
is an alkylene group having 1 to 5 carbon atoms) Examples of amino compounds ()(a) include dimethylaminopropylamine (DMAPA), diethylaminopropylamine (DEAPA), dipropylaminopropylamine (DPAPA), dibutylaminopropyl Examples include amine (DBAPA), dimethylaminoethylamine (DMAEA), diethylaminoelamine (DEAEA), dipropylaminoethylamine (DPAEA), dibutylaminoethylamine (DBAEA), and the like. Among these, DMAPA, DEAPA, etc. are preferred. As the epoxy resin () (a) used in the present invention, the above-mentioned epoxy resin () is used,
Alternatively, a monoepoxy compound such as butylglycidyl ether, phenylglycidyl ether, monoglycidyl ether of P-tert-butylphenol, monoglycidyl ether of Sec-butylphenol, glycidyl methacrylate, Carzilar E (oil Monoesters such as (trade name, manufactured by Kasiel Co., Ltd.) can also be used in combination. The epoxy-amine adduct ()(a) of the present invention is
The epoxy group of the epoxy resin () (a) for 1 equivalent of active amino group NH ₂ of the amino compound () (a),

〔Effect of the invention〕

The effect of the present invention is to provide a one-component curable epoxy resin composition that is excellent in both room temperature storage stability and rapid curing properties, and also has good physical properties of the cured product. [Example] The present invention will be explained in more detail below with reference to Examples. Examples 1 to 2, Comparative Example 1 132 g of DEAPA was added with adekalene di EP- obtained from bisphenol A and epichlorohydrin.
4100 (epoxy equivalent 190, viscosity 25℃ 100 poise) 252
g, phenyl glycidyl ether 16 g, toluene
After adding 70 g of IPA and 70 g of IPA, addition reaction was carried out in a solvent system at 80 to 90°C for 4 hours, and then toluene and IPA were distilled off. From 20 parts of the adduct after completely distilling off the solvent and phenol novolac resin (650 g of phenol, 585 g of formalin (30%), 3.3 g of oxalic acid, and 23 g of hydrochloric acid (15%)), according to the known method for producing phenol resin. 5 parts of the obtained resin (softened at about 100°C) at 150°C.
A time-melting mask reaction was carried out to obtain a curing accelerator A of the present invention. The obtained curing accelerator A was finely pulverized and blended with an epoxy resin and an acid anhydride curing agent in the proportions shown in Table 1 to obtain a one-component curable epoxy resin composition of the present invention. For comparison, trisdimethylaminomethylphenol (DMP-30) was used instead of curing accelerator A.
A similar composition was obtained using Table 1 shows the curability and physical properties of these compositions after curing.

[Table] * Weight change rate after 7 days immersion in water, same as below
Examples 3 to 5 130 g of DEAPA was added with ADEKARESIN EP- obtained from bisphenol A and epichlorohydrin.
Add 640 g of 5100-75X (solid content 75%, epoxy equivalent (solid content equivalent) 470), 9 g of phenyl glycidyl ether, and 45 g of IPA, and heat at 80 to 85 °C under solvent reflux.
After carrying out the time addition reaction, IPA is distilled off. 20 parts of the adduct after completely distilling off the solvent, phenol novolac resin (650 g of phenol, 585 g of formalin (30%), 3.3 g of oxalic acid, and hydrochloric acid (15%))
From 23 g, 9 parts of a resin (with a softening point of about 100° C.) obtained by a known method for producing phenolic resins was subjected to a melt mask reaction at 150° C. for 3 hours to obtain a curing accelerator B of the present invention. The obtained curing accelerator B was pulverized and blended with an epoxy resin and an acid anhydride curing agent in the proportions shown in Table 2 to obtain a one-component curable epoxy resin composition of the present invention. The curability and physical properties of these compositions after curing are shown in Table 2.

【table】

[Claims]

1. As essential constituents, () an epoxy resin having an average of more than one adjacent epoxy group in the molecule; ()(a) a general formula (In the formula, R ₁ and R ₂ are an alkyl group having 1 to 5 carbon atoms, and X is an alkylene group having 1 to 5 carbon atoms.)
Weight ratio of 4-ethylpiperazine/
= Mixed amino compound containing in a ratio of 70/30 to 99/1, an epoxy resin having an average of more than one adjacent epoxy group in the molecule, amino group 1 of mixed amino compound (+)
The epoxy group of the epoxy resin is
An amine-epoxy adduct obtained by reacting at a ratio of 0.8 to 2.0 equivalents,