JPH0780991B2 - Epoxy resin composition and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel low molecular weight epoxy resin composition and a method for producing the same.

This epoxy resin composition is excellent in heat resistance, mechanical properties and workability, and can be used in various fields such as casting, laminating, coating, and semiconductor encapsulation.

[Conventional technology]

Hitherto, there have been various uses of epoxy resins for matrix resins for heat-resistant composite materials, heat-resistant adhesives and the like. These epoxy resins are typically those having a phenol skeleton such as bisphenol A and bisphenol sulfone.
Some have an aromatic amine skeleton such as 4,4'-diaminodiphenylmethane and 3,3'-diaminodiphenylsulfone. These can be obtained by reacting bisphenols and aromatic diamines with epihalohydrin. This epoxy resin is generally used for various applications as described above by mixing with a suitable curing agent and reacting the epoxy group with the functional group of the curing agent.

Also, as a special one, an epoxidized product of a phenol novolac resin, an epoxidized product of a phenol-xylene-bonded resin (Japanese Patent Publication No. 47-13782) and the like are known and used in the same manner.

[Problems to be solved by the invention]

The performance of the above-mentioned typical epoxy resin as a cured product is
It has excellent performance in terms of electrical properties, dimensional stability, and chemical resistance, but it is still insufficient in heat resistance.

Generally, in order to improve the heat resistance, a method of increasing the crosslink density is taken, but on the other hand, it is unavoidable that the resin becomes hard and brittle. As another method for improving heat resistance, introducing a sulfone bond or an amine bond into the epoxy resin skeleton increases the hygroscopicity of the cured resin, which is not preferable in terms of water resistance.

In recent years, it has been required to add higher performance to these epoxy resins. For example, composite materials, adhesives, etc. are required to withstand external stress, especially momentary impact such as stress concentration. Therefore, ideally, elastic deformation like rubber is drawing attention as an important element. The elongation at break of the matrix resin is particularly important as a criterion for judging such elastic deformation. The larger the elongation of the matrix resin, the more the defects of the reinforcing agent such as glass fiber and carbon fiber required for the composite material can be compensated. That is, the strength of the composite material as a whole is improved.

In addition, such composite materials and adhesives are generally wet impregnated and molded, and if the epoxy resin is liquid at room temperature or has a low melting point, use of unnecessary organic solvents or high temperature heating is not necessary. It is not necessary to work in the molten state, and as a result, the usage amount is reduced and workability is improved.

Further, in these matrix resins, long-term storage stability is also important, and it is required that deterioration due to oxygen in the air is small. This oxidation resistance mainly comes from the structure of the resin, and the phenol novolac resin structure cannot solve this problem.

Of these required elements, an epoxidized phenol-xylene-bonded resin having improved heat resistance and oxidation resistance has been proposed (Japanese Patent Publication No. Sho 47-13782, Japanese Patent Laid-Open No. 60-1).
12813).

However, each of these epoxy resins is composed of a composition obtained by subjecting a phenol and an aralkyl ether to a condensation reaction so that substantially no unreacted material remains. For this reason,
The amount of phenol used per mol of the bifunctional aralkyl ether is limited to the range of 1.3 to 3 mol, but the resin obtained in this range has a large molecular weight and is unsatisfactory in terms of fluidity and performance. . Therefore, not only is it inefficient in terms of workability, but also it does not reach the level required for composite materials, etc. in terms of the inherent mechanical properties, especially the elongation at break.

An epoxy resin composition and a method for producing the same that can sufficiently solve the problems described above have not yet been known.
However, the present inventors have found that the problem can be solved by using a certain low molecular weight epoxy resin composition, and applied for the invention first (Japanese Patent Application No. 62-070).
281).

The present invention has been made in view of the above problems, the object is to show sufficient performance in heat resistance, water resistance, oxidation resistance, mechanical properties such as impact resistance, excellent workability, further Matrix resin for heat-resistant composite materials that shows sufficient heat resistance,
An object of the present invention is to provide an epoxy resin composition for use in a heat resistant adhesive and the like, and a method for producing the same.

[Means for solving problems]

The present inventors have completed the present invention as a result of earnest studies to achieve the above object.

That is, the invention has the general formula (a) (However, in the formula, R ¹ represents hydrogen or an alkyl group having 1 to 9 carbon atoms, R ² represents an alkyl group having 1 to 9 carbon atoms,
n shows the integer of 0-5. ), Wherein the total of n = 0 and n = 1 is 50 mol% or more, and when n = 5 is less than 15 mol%, the alkylphenol aralkyl resin composition and epihalohydrin are hydrogen halides. An epoxy resin composition obtained by reacting in the presence of an acceptor, and a general formula (b) (However, R ³ in the formula represents a lower alkyl group having 4 or less carbon atoms.) The α, α′-dialkoxy-p-xylene represented by the general formula (c) (In the formula, R ¹ represents hydrogen or an alkyl group having 1 to 9 carbon atoms, and R ² represents an alkyl group having 1 to 9 carbon atoms.) It is represented by the general formula (a) obtained by reacting in the presence of a catalyst and separating unreacted alkylphenol, and n = 0.
And n = 1, the total of 50 mol% or more, and n = 5
A method for producing an epoxy resin composition, which comprises reacting a reaction product containing an alkylphenol aralkyl resin composition having a composition ratio of less than 15 mol% as a main component with epihalohydrin in the presence of a hydrogen halide acceptor. is there.

The epoxidized product of the alkylphenol aralkyl resin composition obtained by the method of the present invention gives a good cured product when combined with various curing agents. For example, when liquid diaminodiphenylmethane (MDA) (trade name Epicure Z, manufactured by Shell Chemical Co., Ltd.) is combined as a curing agent, the flexural strength, flexural modulus, Properties such as tensile strength and elongation are improved. Furthermore, since the epoxy resin composition of the present invention has an alkyl substituent on the benzene ring of the main chain, it exhibits superior heat resistance to the epoxy resin composition of Japanese Patent Application No. 62-070281.

Furthermore, the epoxy resin composition of the present invention has a low molecular weight,
Since it is liquid at room temperature or has a low melting point, operations such as compounding, coating, and impregnation are extremely good, and a uniform cured product can be obtained.

In order to obtain the above effects, the alkylphenol aralkyl resin composition represented by the general formula (a) having a repeating number n of 5 or less is used in the present invention. However, n
Is less than 15 mol, and the sum of n = 0 and n = 1 is 50 mol% or more. Furthermore, n = 0 and n =
It is more desirable that the total of 1 is 60 mol% or more. Further, R ¹ and R ^{2 in} the case of an alkyl group have 1 to 9 carbon atoms.

General formula (a) having a range of the number of repetitions n as described above
Specific examples of the method for obtaining the alkylphenol aralkyl resin composition represented by

First, 4 mol or more of alkylphenol, preferably 5 to 20 mol, more preferably 6 to 15 mol, relative to 1 mol of α, α'-dialkoxy-p-xylene represented by the general formula (b). In addition, the temperature is raised with stirring in the presence of an acid catalyst to react at the temperature described below. The alcohol produced as the reaction proceeds is trapped outside the system. If necessary, a trace amount of alcohol remaining in the system is removed with nitrogen to the outside of the system. After the reaction is completed, the remaining unreacted alkylphenol is distilled off under vacuum or by steam distillation, and the residual resin is the alkylphenol aralkyl resin composition of the present invention.

In this α, α′-dialkoxy-p-xylene, when the alkyl group R ³ has 4 or less carbon atoms, the reaction is fast,
Also, when the number of carbon atoms is 4, that is, tert- in the butyl group
Butyl groups tend to react slowly.

Therefore, for use in the present invention, preferably α, α′-dimethoxy-p-xylene, α, α′-
Diethoxy-p-xylene, α, α′-di-n-propoxy-p-xylene, α, α′-isopropoxy-p-
Xylene, α, α′-di-n-butoxy-p-xylene, α, α′-di-sec-butoxy-p-xylene,
Examples thereof include α, α′-diisobutyl-p-xylene, but are not limited thereto.

The alkylphenol represented by the general formula (c) used in the present invention includes, for example, o-cresol,
m-cresol, p-cresol, o-ethylphenol, p-ethylphenol, mixed cresol, pn-
Propylphenol, o-isopropylphenol, p
-Isopropylphenol, mixed isopropylphenol, o-sec-butylphenol, m-tert-butylphenol, p-tert-butylphenol, pentylphenol, p-octylphenol, p-nonylphenol, 2,3-dimethylphenol, 2,4-dimethylphenol , 2,6-dimethylphenol, 3,4-dimethylphenol, 2,4-di-s-butylphenol, 3,5-dimethylphenol, 2,6-di-s-butylphenol, 2,6-di-
t-butylphenol, 3-methyl-4-isopropylphenol, 3-methyl-5-isopropylphenol, 3-methyl-6-isopropylphenol, 2-t
-Butyl-4-methylphenol, 3-methyl-6-t
-Butylphenol, 2-t-butyl-4-ethylphenol and the like can be mentioned.

The reaction temperature must be 110 ° C or higher, and
If it is lower than 10 ° C, the reaction becomes extremely slow. Further, in order to shorten the reaction time as much as possible, a temperature range of about 130 to 240 ° C is desirable. The reaction time is 1 to 20 hours.

The acid catalyst may be an inorganic or organic acid, especially a mineral acid such as hydrochloric acid, phosphoric acid, sulfuric acid or formic acid, or zinc chloride,
Friedel-Crafts catalysts such as aluminum chloride, stannic chloride, ferric chloride, organic sulfonic acids such as methane sulfonic acid or p-toluene sulfonic acid may be used alone or in combination. The amount of the catalyst used is about 0.01 to 5% by weight based on the total weight of the alkylphenol and α, α′-dialkoxy-p-xylene.

A known method can be applied to the method for epoxidizing the reaction product containing the alkylphenol aralkyl resin composition thus obtained as a main component.

That is, the residual resin composition and epirohalohydrin, preferably epichlorohydrin, are usually used in the temperature range of 40 to 120 ° C. in the presence of a hydrogen halide acceptor.

Particularly suitable as the hydrogen halide acceptor of the present invention are alkali metal hydroxides such as potassium hydroxide and sodium hydroxide. The hydrogen halide acceptor is preferably added slowly to the heated mixture of said alkylphenol aralkyl resin composition and epihalohydrin to maintain the pH of the reaction mixture at about 6.5-10.

The proportion of epihalohydrin used in the reaction depends on the hydroxyl group content of the residual resin composition, but is usually 2.0 to 30 equivalents, preferably 10 equivalents or less in excess of epihalohydrin in consideration of economic efficiency. Excess acceptor substances and salts produced as by-products are removed from the reaction product by means such as vacuum distillation and washing with water.

The epoxy resin composition produced by the method of the present invention can be cured with a conventional curing agent. Typical examples of curing agents are conventional curing agents for epoxy resin compositions such as bis (4-aminophenyl) methane, aniline / formaldehyde resin, bis (4-aminophenyl) sulfone, propane-1,3-diamine. , Hexamethylenediamine, diethylenetriamine, triethylenetetramine,
2,2,4-Trimethylhexamine-1,6-diamine, m-xylylenediamine, bis (4-aminocyclohexyl)
Aliphatic, cycloaliphatic, aromatic and heterocyclic amines such as methane, 2,2-bis (4-aminocyclohexyl) propane and 3-aminomethyl-3,5,5-trimethylcyclohexylamine (isophoronediamine) , Polyaminoamides such as obtained from aliphatic polyamines and dimerized or trimerized fatty acids; resorcinol, hydroquinone, 2,
Polyphenols such as 2-bis (4-hydroxyphenyl) propane and phenol / aldehyde resins;
Polythiols such as those commercially available as "Thiochols"; eg phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, hexachloroendomethylenetetrahydrophthalic anhydride, pyromellitic anhydride, 3,3 ', 4, Includes 4'-benzophenone tetracarboxylic acid dianhydride, acids of said anhydrides and polycarboxylic acids and their anhydrides such as isophthalic acid and terephthalic acid. When the curing agent is a polycarboxylic acid or an anhydride thereof, usually 0.4 to 1.1 equivalents of carboxyl groups or anhydride groups are used per equivalent of epoxy groups. When the curing agent is polyphenol, it is preferred to use 0.75 to 1.25 phenolic hydroxyl groups per equivalent of epoxy groups.

Curing agents are generally used at 1 to 40 parts by weight per 100 parts of epoxy.

〔Example〕

 Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1 In a reaction vessel equipped with a stirrer, a thermometer, and a Dean Stark azeotropic distillation trap, α, α'-dimethoxy-p-
Xylene 1328 g (0.8 mol), o-cresol 868 g (8.0
Mol) and 5 g of paratoluenesulfonic acid were charged, and the mixture was stirred while maintaining the mixed solution at 130 to 150 ° C. During the reaction, generated methanol was sequentially removed from the system through the trap.

After 3 hours, the generation of methanol disappeared and the condensation was completed. Then, unreacted o-cresol was distilled off under reduced pressure to obtain 234 g of an alkylphenol aralkyl resin composition having the structure of the general formula (a).

The composition of the obtained resin composition was measured by high performance liquid chromatography. As a result, n = 0 was 77.3, n = 1 was 18.7, and n was 18.7.
= 2 was 3.5 (mol%). The softening point (according to JIS, K-2548) of this resin composition was 32 ° C.

Next, 205 g of the obtained alkylphenol aralkyl resin composition and 730 g (7.9 mol) of epichlorohydrin were mixed and charged into a reaction vessel equipped with a stirrer, a Dean Stark azeotropic distillation trap and a dropping funnel.

The temperature of this mixture was raised to 115 to 119 ° C. with stirring, 195 g of 40% aqueous sodium hydroxide solution was added dropwise at the same temperature over 4 hours, the distilled water was continuously separated and recovered, and the phase of epichlorohydrin was placed in the reactor. Returned to. After completion of dropping, the reaction is completed by removing distilled water.

After this, excess epichlorohydrin was distilled under reduced pressure, the reaction product was dissolved in 500 g of methyl isobutyl ketone (MIBK), sodium chloride and a small excess of sodium hydroxide were filtered off, the solvent was distilled off under reduced pressure, and the yellow 249 g of an oily epoxy resin composition was obtained.

The epoxy equivalent of the resin composition was 230 g / eq, and the viscosity (by E-type viscometer manufactured by Tokyo Keiki Co., Ltd.) was 172 g / cm · sec (35 ° C.).

The result of IR analysis (liquid film method) of this resin is shown in FIG.

Example 2 In a reaction vessel equipped with a stirrer, a thermometer, and a Dean Stark azeotropic distillation trap, α, α'-dimethoxy-p-
Xylene 140g (0.84mol), mixed cresol 910g (8.4
Mol) and 5 g of paratoluenesulfonic acid were charged, and the mixture was stirred while maintaining the mixed solution at 130 to 150 ° C. During the reaction, generated methanol was sequentially removed from the system through the trap.

After 3 hours, the generation of methanol disappeared and the condensation was completed. Then, the unreacted mixed cresol was distilled off under reduced pressure to obtain 245 g of an alkylphenol aralkyl resin composition having the structure of the general formula (a).

The composition of the obtained resin composition was measured by high performance liquid chromatography. As a result, n = 0 was 74.8, n = 1 was 19.1.
= 2 was 4.6, and n ≧ 3 was 1.5 (mol%). The softening point (according to JIS, K-2548) of this resin composition is 5
It was 6 ° C.

Then, 130 g of the obtained alkylphenol aralkyl resin composition and 500 g (5.4 mol) of epichlorohydrin were mixed and charged into a reaction vessel equipped with a stirrer, a Dean Stark azeotropic distillation trap and a dropping funnel.

The temperature of this mixture was raised to 115 to 119 ° C with stirring, then 230 g of 40% aqueous sodium hydroxide solution was added dropwise at the same temperature over 4 hours, the distilled water was continuously separated and recovered, and the phase of epichlorohydrin was placed in the reactor. Returned to. After completion of dropping, the reaction is completed by removing distilled water.

After this, excess epichlorohydrin was distilled under reduced pressure, the reaction product was dissolved in 350 g of methyl isobutyl ketone (MIBK), sodium chloride and a small excess of sodium hydroxide were filtered off, the solvent was distilled off under reduced pressure, and the yellow 167 g of the epoxy resin composition of was obtained.

The epoxy equivalent of the resin composition was 236 g / eq, and the viscosity (by E-type viscometer manufactured by Tokyo Keiki Co., Ltd.) was 651 g / cm · sec (35 ° C.).

The results of IR analysis (liquid film method) of this resin composition are shown in FIG.

Example 3 In a reaction vessel equipped with a stirrer, a thermometer, and a Dean Stark azeotropic distillation trap, α, α'-dimethoxy-p-
Xylene 166 g (1 mol), 2,6-dimethylphenol 732
g (6 mol) and 6 g of paratoluenesulfonic acid were charged, and the mixture was stirred while maintaining the temperature at 130 to 150 ° C. During the reaction, generated methanol was sequentially removed from the system through the trap.

After 3 hours, the generation of methanol disappeared and the condensation was completed. Then, unreacted 2,6-dimethylphenol was distilled off under reduced pressure to obtain 317 g of an alkylphenol aralkyl resin composition having the structure of the general formula (a).

The composition of the obtained resin composition was measured by high performance liquid chromatography to find that n = 0 was 62.3, n = 1 was 25.0, and n was 25.0.
= 2 was 8.6, and n ≧ 3 was 4.1 (mol%). The softening point (according to JIS, K-2548) of this resin composition is 4
It was 9 ° C.

Next, 200 g of the obtained alkylphenol aralkyl resin composition and 530 g (5.7 mol) of epichlorohydrin were mixed and charged into a reaction vessel equipped with a stirrer, a Dean Stark azeotropic distillation trap and a dropping funnel.

The temperature of this mixture was raised to 115 to 119 ° C. with stirring, then 135 g of 40% sodium hydroxide aqueous solution was added dropwise at the same temperature over 4 hours, the distilled water was continuously separated and recovered, and the phase of epichlorohydrin was placed in the reactor. Returned to. After completion of dropping, the reaction is completed by removing distilled water.

After that, excess epichlorohydrin was distilled under reduced pressure, the reaction product was dissolved in 500 g of methyl isobutyl ketone (MIBK), sodium chloride and a slight excess of sodium hydroxide were filtered off, and the solvent was distilled off under reduced pressure to give a brown powder. 242 g of the epoxy resin composition of was obtained.

The epoxy equivalent of the resin composition was 243 g / eq, and the viscosity (by E-type viscometer manufactured by Tokyo Keiki Co., Ltd.) was 879 g / cm · sec (35 ° C.).

The result of IR analysis (liquid film method) of this resin composition is shown in FIG.

Comparative Example 1 α, α′-dimethoxy-p-in a reaction vessel equipped with a stirrer, a thermometer, and a Dean Stark azeotropic distillation trap.
250 g (1.5 mol) of xylene, 847 g (9 mol) of phenol, and 1.1 g of paratoluenesulfonic acid were charged, and stirring was performed while maintaining the mixed solution at 130 to 150 ° C. During the reaction, the produced methanol was sequentially removed from the system through the trap.

After 2 hours, the generation of methanol disappeared and the condensation was completed. Then, unreacted phenol was distilled off under reduced pressure to obtain 393 g of a phenol aralkyl resin composition having the structure of the general formula (a).

The composition of the obtained resin composition was measured by high performance liquid chromatography. As a result, n = 0 was 60.3, n = 1 was 24.3, n
= 2 was 9.2, n = 3 was 3.8, and n ≧ 4 was 2.4 (mol%). In addition, the softening point (JIS, K
(According to −2548) was 45 ° C.

Then, 393 g of the obtained phenol aralkyl resin composition
And 1100 g (11.9 mol) of epichlorohydrin were mixed and charged into a reaction vessel equipped with a stirrer, a Dean Stark azeotropic distillation trap and a dropping funnel.

The temperature of this mixture was raised to 115 to 119 ° C with stirring, 275 g of 40% aqueous sodium hydroxide solution was added dropwise at the same temperature over 4 hours, the distilled water was continuously separated and recovered, and the phase of epichlorohydrin was placed in the reactor. Returned to. After completion of dropping, the reaction is completed by removing distilled water.

After that, excess epichlorohydrin was distilled under reduced pressure, the reaction product was dissolved in 1500 g of methyl isobutyl ketone (MIBK), sodium chloride and a small excess of sodium hydroxide were filtered, and the solvent was distilled off under reduced pressure to give a yellow 465 g of an oily epoxy resin composition was obtained.

The epoxy equivalent of the resin composition was 227 g / eq, and the viscosity (by E-type viscometer manufactured by Tokyo Keiki Co., Ltd.) was 468 g / cm · sec (35 ° C.).

Example of use Liquid epoxy resin compositions obtained in Examples 1 to 3 and Comparative Example 1 and each of Epicoat 828 (manufactured by Ciel Chemical Co.) introduced from bisphenol A were used as a curing agent in liquid MDA (Epicure Z; Manufactured) was blended under the conditions shown in Table-1, and the mixture was casted, and the mechanical properties of the cured resin after processing were measured.

The results are shown in Table-1. The results of the epoxy resin compositions obtained in Examples 1 to 3 are shown as Experimental Examples 1 to 3, and the results of the epoxy resin composition obtained in Comparative Example 1 are shown as Comparative Experimental Example 1. The results of (Ciel Chemical) are shown as Comparative Experimental Example 2.

[Effects of the Invention] As described above, the epoxy resin composition of the present invention has a low molecular weight, and since it is a liquid or a low melting point at room temperature, it has excellent compatibility with various curing agents, and is mixed and applied. The operations such as impregnation and the like are extremely easily performed, and a homogeneous cured product is obtained. The cured product has excellent properties in mechanical properties such as impact resistance, water resistance, oxidation resistance, particularly tensile strength and elongation, and also has sufficient heat resistance.

The epoxy resin composition of the present invention having the above advantages can be expected to be applied to various applications, and particularly to the electronic material field where such performance has been conventionally demanded.

[Brief description of drawings]

1 to 3 are diagrams showing IR analysis results (liquid film method) of the epoxy resins obtained in Examples 1 to 3.

Continuation of front page (56) References JP-A-60-112813 (JP, A) JP-A-60-135449 (JP, A) JP-B 47-13782 (JP, B1)

Claims (2)

[Claims] 1. A general formula (a) (However, in the formula, R ¹ represents hydrogen or an alkyl group having 1 to 9 carbon atoms, R ² represents an alkyl group having 1 to 9 carbon atoms,
n shows the integer of 0-5. ), Wherein the total of n = 0 and n = 1 is 50 mol% or more, and when n = 5 is less than 15 mol%, the alkylphenol aralkyl resin composition and epihalohydrin are hydrogen halides. An epoxy resin composition obtained by reacting in the presence of an acceptor. 2. General formula (b) (However, R ³ in the formula represents a lower alkyl group having 4 or less carbon atoms.) The α, α′-dialkoxy-p-xylene represented by the general formula (c) (In the formula, R ¹ represents hydrogen or an alkyl group having 1 to 9 carbon atoms, and R ² represents an alkyl group having 1 to 9 carbon atoms.) General formula (a) obtained by reacting in the presence of a catalyst to separate unreacted alkylphenol (However, in the formula, R ¹ represents hydrogen or an alkyl group having 1 to 9 carbon atoms, R ² represents an alkyl group having 1 to 9 carbon atoms,
n shows the integer of 0-5. And a reaction product mainly composed of an alkylphenol aralkyl resin composition having a composition ratio of 50 mol% or more for n = 0 and n = 1 and less than 15 mol% for n = 5. And an epihalohydrin in the presence of a hydrogen halide acceptor, a method for producing an epoxy resin composition.