JPH0195122A - Epoxy resin and its praparation - Google Patents

Abstract

PURPOSE:To obtain an epoxy resin having excellent compatibility with a hardener, being capable of giving a cured product having excellent impact resistance, mechanical characteristics, water resistance, oxidation resistance and heat resistance, by reacting a specified alkylphenol aralkyl resin and an epihalohydrin in the presence of a hydrogen halide acceptor. CONSTITUTION:An alkylphenol aralkyl resin of formula III (wherein n is 0-5) is obtd. by reaching an alpha,alpha'-dialcoxy-p-xylene of formula I (wherein R<3> is 4C or lower alkyl) and an alkylphenol of formula II (wherein R<1> is H or R<2>; R<2> is 1-9 alkyl) with the molar ratio of 4 or higher in the presence of 0.01-5wt.% acidic catalyst such as hydrochloric acid, p-toluenesulfonic acid, etc., at 110 deg.C or higher for 1-20hr and separating unreacted alkylphenol. Then, 2-3 equivalent excess of epihalohydrin is mixed therein and heated at 40-120 deg.C to obtain a mixture, whereto a hydrogen halide acceptor such as NaOH is added in such a way that the pH of the reaction mixture is kept at 6.5-10 and the reaction is carried out in the presence of the acceptor.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel low molecular weight epoxy resin and a method for producing the same.

This epoxy resin has excellent heat resistance, mechanical properties, and workability, and can be used for many purposes such as casting, lamination, coating, and semiconductor sealing.

(Prior Art) Conventionally, epoxy resins have been used in a wide variety of applications, such as matrix resins for heat-resistant composite materials and heat-resistant adhesives. These epoxy resins typically have a phenol skeleton such as bisphenol A or bisphenol sulfone, or have an aromatic amine skeleton such as 4,4'-diaminodiphenylmethane or 3.3°-diaminodiphenylsulfone. There is.

These can be obtained by reacting bisphenols and aromatic diamines with shrimp helohydrin. This epoxy resin is generally mixed with a suitable curing agent and used for the various applications mentioned above by reacting the epoxy groups with the functional groups of the curing agent.

Further, as special products, epoxidized products of phenol nophorac resin and epoxidized products of phenol-xylene bonded resin (Japanese Patent Publication No. 47-13782) are known, and are used in the same manner.

[Problem that the invention seeks to solve]

The performance of the typical epoxy resin as a cured product is as follows:
Although it has excellent performance in terms of electrical properties, dimensional stability, and chemical resistance, it is still insufficient in terms of heat resistance.

Generally, in order to improve heat resistance, a method is taken to increase the crosslinking density, but on the other hand, this inevitably results in the resin becoming hard and brittle. Furthermore, as another method for improving heat resistance, introducing sulfone bonds, amine bonds, etc. into the epoxy resin skeleton increases the hygroscopicity of the cured resin, which is undesirable in terms of water resistance.

In recent years, it has become necessary to add more advanced performance to these epoxy resins.

For example, materials for composite materials, adhesives, etc. are required to withstand external stress, especially instantaneous impact such as stress concentration.

For this reason, ideally, elastic deformation like rubber is attracting attention as an important element. As a criterion for determining such elastic deformation, elongation of the matrix resin at break is especially important. The greater the elongation of the matrix resin, the more it can compensate for the drawbacks of reinforcing agents such as glass fiber and carbon fiber required for composite materials. In other words, 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, unnecessary organic solvents or high-temperature heating may be used. It is not necessary to work in a molten state, resulting in a reduction in the amount used and improved workability.

Furthermore, long-term storage stability is also important for these matrix resins, and they are also required to be less susceptible to deterioration due to oxygen in the air. This oxidation resistance is mainly derived from the structure of the resin, and this problem cannot be solved with a phenol novolac resin structure.

Among these required elements, an epoxidized phenol-xylene bonded resin with improved heat resistance and oxidation resistance has been proposed (Japanese Patent Publication No. 47-1: 1782,
JP-A-60-112813).

However, all of these epoxy resins are composed of a composition in which phenol and aralkyl ether are subjected to a condensation reaction so that substantially no unreacted materials remain. For this reason,
The amount of phenol used per mole of bifunctional aralkyl ether is limited to 1.3 to 3 moles, or the resins obtained within this range have large molecular weights and are unsatisfactory in terms of fluidity and performance. It is. Therefore, it is not only inefficient in terms of workability, but also has inherent mechanical properties,
In particular, the elongation rate at break does not reach the level required for composite materials.

Epoxy resins and methods for producing the same that can sufficiently solve the problems described above are not yet known. However, the present inventors found that this problem could be solved by using a certain kind of low-molecular epoxy resin, and filed an application for the invention (Japanese Patent Application No. 62-070281
).

The present invention has been made in view of the above-mentioned problems, and its purpose is to exhibit sufficient performance in heat resistance, water resistance, and oxidation resistance, and to have excellent mechanical properties such as impact resistance and workability. Matrix resin for heat-resistant composite materials that exhibits sufficient heat resistance,
An object of the present invention is to provide an epoxy resin for use in heat-resistant adhesives, etc., and a method for producing the same.

[Means for solving problems]

As a result of intensive studies to achieve the above object, the inventors have completed the present invention.

That is, the present invention is based on the formula (a), where R1 represents hydrogen or an alkyl group having 1 to 9 carbon atoms, R2 represents an alkyl group having 1 to 9 carbon atoms, and n represents 0 to 9 carbon atoms. Indicates an integer of 5. ) and an epoxy resin obtained by reacting an alkylphenol aralkyl resin represented by the formula (b) with epihalohydrin in the presence of a hydrogen halide acceptor; α, α゛-dialkoxy p-xylene represented by the general formula (C) (wherein R1 represents hydrogen or an alkyl group having 1 to 9 carbon atoms, and R2 represents a An alkylphenol aralkyl resin represented by general formula (a) obtained by reacting alkylphenols represented by (1 to 9 alkyl groups) in the presence of an acid catalyst at a molar ratio of 4 or more and separating unreacted alkylphenols. A reaction product whose main component is
This is a method for producing an epoxy resin, which is characterized by reacting epihalohydrin with a hydrogen halide acceptor in the presence of a hydrogen halide acceptor.

The epoxidized product of alkylphenol aralkyl resin obtained by the method of the present invention can be combined with various curing agents to give a good cured product.

For example, when liquid diaminodiphenylmethane (MDA) (trade name Epicure Z, manufactured by Shell Chemical) is combined as a curing agent, the bending strength, bending modulus, Properties such as tensile strength and elongation rate are improved. Furthermore,
Since the epoxy resin of the present invention has an alkyl substituent on the benzene ring of the main chain, it exhibits better heat resistance than the epoxy resin disclosed in Japanese Patent Application No. 62-070281.

Furthermore, the epoxy resin of the present invention has a low molecular weight and is liquid or has a low melting point at room temperature, so operations such as blending, coating, and impregnation are extremely easy, and a homogeneous cured product can be obtained. It will be done.

In order to obtain the above effects, - the repeating number n of the alkylphenol aralkyl resin represented by the formula (a)
is 5 or less for use in the present invention. However, in order to obtain a more pronounced effect, it is desirable that the amount of n = 5 is less than 15% by weight, or the total of n = 0 and n = 1 is preferably 50 mol% or more, Furthermore, it is more desirable that the total of n=0 and n=1 is 60 mol% or more. Further, in the case of an alkyl group, R1 and R2 have 1 to 9 carbon atoms.

General formula (a) having the repeating number n range as described above
A specific example of the method for obtaining the alkylphenol aralkyl resin represented by is described below.

First, an alkylphenol is added in an amount of 4 moles or more, preferably 5 to 20 moles, more preferably 6 to 15 moles, to 1 mole of α,α゛-dialkoxy p-xylene represented by formula (b). , the temperature is raised while stirring in the presence of an acid catalyst, and the reaction is carried out at the temperature described below. The alcohol produced as the reaction progresses is trapped outside the system.

If necessary, trace amounts of alcohol remaining in the system are removed from the thread using nitrogen. After completion of the reaction, the remaining unreacted alkylphenol is distilled off under vacuum or by steam distillation, and the residual resin obtained is the alkylphenol aralkyl resin of the present invention.

In this α, α゛-dialkoxy p-xylene, if the number of carbon atoms in the alkyl group R3 is 4 or less, the reaction is fast;
rt-butyl groups tend to react slowly.

Therefore, those used in the present invention are preferably α, α°-dimethoxy p-xylene, α, α°-jetoxy p-xylene, α, α“-di-n-propoxy-p-xylene, α, α°-isopropoxy p-xylene, α, α゛-di-n-butoxy p-xylene,
α, α゛-c-5ec-butoxyp-xylene, α,
Examples include α°-diisobutyl-p-xylene,
It is not limited to these.

Further, examples of the alkylphenol represented by formula (C) used in the present invention include 0-cresol,
m-cresol, ρ-cresol, 0-ethylphenol, p-ethylphenol, mixed cresol, p-n-
Propylphenol, 0-isopropylphenol, P
-isopropylphenol, mixed isopropylphenol, o-5ec-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-
Examples include methylphenol, 3-methyl-6-t-butylphenol, and 2-t-butyl-4-ethylphenol.

The reaction temperature must be 110°C or higher; if it is lower than 110°C, the reaction will be extremely slow. In addition, in order to shorten the reaction time as much as possible, approximately 130 to 24
A temperature range of 0°C is preferred. Reaction time is 1 to 20 hours.

Acid catalysts include inorganic or organic acids, in particular mineral acids, such as hydrochloric acid, phosphoric acid, sulfuric acid or formic acid, or zinc chloride,
Free sol fluorocarbon catalysts such as aluminum chloride, stannic chloride, and ferric chloride, and organic sulfonic acids such as methanesulfonic acid or p-toluenesulfonic acid may be used alone or in combination. The amount of catalyst used is about 0.01 to 5% by weight of the total weight of alkylphenol, α, α°-dialkoxy p-xylene.

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

That is, the reaction is carried out using residual resin and epihalohydrin, preferably epichlorohydrin, usually within a temperature range of 40 to 120 DEG C., in the presence of a hydrogen halide acceptor.

Particularly suitable as hydrogen halide acceptors according to the invention are alkali metal hydroxides such as potassium hydroxide, sodium hydroxide. Preferably, the hydrogen halide acceptor is added slowly to the heated mixture of the alkylphenol aralkyl resin and epihalohydrin so as to maintain the p)I of the reaction mixture between about 6.5 and IO.

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

The epoxy resin produced by the method of the invention can also be cured with conventional curing agents.

Typical examples of hardeners are conventional hardeners for epoxy resins such as bis(4-aminophenyl)methane, aniline/formaldehyde resins, bis(4-aminophenyl)sulfone, propane-1,3-diamine, hexa Methylenediamine, diethylenetriamine, triethylenetetramine, 2,2,4-trimethylhexamino-1,6-diamine, m-xylylenediamine, bis(4-aminocyclohexyl)methane, 2,2-bis(4-aminocyclohexyl) ) propane and 3-aminomethyl-3,5,
Aliphatic, cycloaliphatic, aromatic and heterocyclic amines such as 5-trimethylcyclohexylamine (isophorone diamine), polyaminoamides such as those obtained from aliphatic polyamines and trimerization 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; e.g. phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, hexachloro endomethylenetetrahydrophthalic anhydride, pyromellitic anhydride, 3,3°,4,4-benzophenonetetracarboxylic acid 2y# hydrate, the acids of the aforementioned anhydrides and polycarboxylic acids such as isophthalic acid and terephthalic acid and their Contains anhydrides. When the curing agent is a polycarboxylic acid or anhydride thereof, usually 0.4 to 1.1 equivalents of carboxyl group or anhydride group are used per equivalent of epoxy group. Curing. When the agent is a polyphenol, it is preferred to use 0.75 to 1.25 phenolic hydroxyl groups per equivalent of epoxy group.

Hardeners are generally used in amounts of 1 to 40 parts by weight per 100 parts of epoxy.

〔Example〕

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

Example 1 α,α゛-dimethoxyp-
132.8 g (0.8 mol) of xylene, 868 g (8.0 mol) of 0-cresol, and 5 g of para-toluenesulfonic acid were charged, and the mixed solution was heated at 130 to 150°C.
Stirring was performed while maintaining the temperature. During the reaction, generated methanol was sequentially removed from the system through a trap.

After 3 hours, no methanol was generated and the condensation was completed. Next, unreacted 0-cresol was removed by distillation under reduced pressure,
- 234 g of alkylphenol aralkyl resin having the structure of formula (a) was obtained.

As a result of measuring the composition of the obtained resin by high performance liquid chromatography, n=0 was 77.3, n=1 was 18.7,
The one with n=2 was 3.5 (mol%).

Moreover, the softening point (according to JIS-2548) of this resin was 32°C.

Then, the obtained alkylphenol aralkyl resin 2
05g and 730g (7.9 mol) of epichlorohydrin
were mixed and charged to a reaction vessel equipped with a stirrer, a Dean-Stark azeotropic distillation trap, and a dropping funnel.

While stirring this mixture, the temperature was raised to 115-119°C, and at the same temperature, 195 g of a 40% aqueous sodium hydroxide solution was added.
was added dropwise over 4 hours, and the distilled water was continuously separated and collected.
The epichlorohydrin phase was returned to the reactor. After the dropwise addition is completed, the reaction is terminated by removing the distilled water.

After this, excess epichlorohydrin was distilled under reduced pressure, and the reaction product was converted into 500 g of methyl isobutyl ketone (MIBK).
After filtering out sodium chloride and a slight excess of sodium hydroxide, the solvent was distilled off under reduced pressure to obtain 249 g of a yellow oily epoxy resin.

The epoxy equivalent of the resin is 230 g/eq, and the viscosity (according to Tokyo Keiki E-type viscometer) is 172 g/cm -5
ec (35°C).

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

Example 2 α,α°-Dimethoxy p-
140 g (0.84 mol) of xylene, 910 g (8.4 mol) of mixed cresol, and 5 g of para-toluenesulfonic acid were charged, and the mixed solution was stirred while being maintained at 130 to 150°C. During the reaction, generated methanol was sequentially removed from the system through a trap.

After 3 hours, no methanol was generated and the condensation was completed. Next, unreacted mixed cresol was removed by distillation under reduced pressure.
245 g of alkylphenol aralkyl resin having the structure of general formula (a) was obtained.

The composition of the obtained resin was measured by high performance liquid chromatography and found that n=o was 74.8, n=1 was 19.1,
4.6 for n=2, 1.5 for n≧3 (mol%)
Met. In addition, the softening point of this resin (JIS, -25
48) was 56°C.

Then, the obtained alkylphenol aralkyl resin 1
30 g 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 115-119°C while stirring, and at the same temperature, 230 g of a 40% aqueous sodium hydroxide solution was added dropwise over 4 hours. The distilled water was continuously separated and collected, and the epichlorohydrin phase was transferred to the reactor. I returned it to . After finishing dropping,
The reaction is terminated by removing the distillate water.

After this, excess epichlorohydrin was distilled under reduced pressure, and 350 g of methyl isobutyl ketone (MIBK) was obtained as a reaction product.
After filtering out sodium chloride and a slight excess of sodium hydroxide, the solvent was distilled off under reduced pressure to obtain 167 g of a yellow epoxy resin.

The epoxy equivalent of the resin is 23ag/eq, and the viscosity (according to Tokyo Keiki E-type viscometer) is 651g/cm -5
EC (35°C).

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

Example 3 α,α゛-Dimethoxy P-
166 g (1 mol) of xylene, 732 g (6 mol) of 2°6-dimethylphenol, and 6 g of para-toluenesulfonic acid were charged, and the mixed solution was stirred while being maintained at 130 to 150°C. During the reaction, generated methanol was sequentially removed from the thread through the trap.

After 3 hours, no methanol was generated and the condensation was completed. Next, unreacted 2,6-dimethylphenol was removed by distillation under reduced pressure to obtain 317 g of an alkylphenol aralkyl resin having the structure of general formula (a).

The composition of the obtained resin was measured by high performance liquid chromatography and found that n=0 was 62.3, n=1 was 25.0,
n=2 is 8.6, n≧3 is 4.1 (mol%)
Met. In addition, the softening point (JIS) of this resin.

K-2548) was 49°C.

Then, the obtained alkylphenol aralkyl resin 2
00g and epichlorohydrin 530g (5.7 mol)
were mixed and charged to a reaction vessel equipped with a stirrer, a Dean-Stark azeotropic distillation trap, and a dropping funnel.

While stirring this mixture, the temperature was raised to 115-119°C, and at the same temperature, 135 g of a 40% sodium hydroxide aqueous solution was added.
was added dropwise over 4 hours, and the distilled water was continuously separated and collected.
The epichlorohydrin phase was returned to the reactor. After the dropwise addition is completed, the reaction is terminated by removing the distilled water.

After this, excess epichlorohydrin was distilled under reduced pressure, and the reaction product was converted into 500 g of methyl isobutyl ketone (MIBK).
After filtering out sodium chloride and a slight excess of sodium hydroxide, the solvent was distilled off under reduced pressure to obtain 242 g of a brown epoxy resin.

The epoxy equivalent of the resin is 243 g/eq, and the viscosity (according to Tokyo Keiki E-type viscometer) is 879 g/cm-8e.
c (35°C).

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

Comparative Example 1 α, α°-Dimethoxy p-
xylene 250g (1.5 mol), phenol 847
g (9 moles), and 1.1 g of para-toluenesulfonic acid.
was charged, and the mixed solution was stirred while being maintained at 130 to 150°C. During the reaction, methanol produced was sequentially removed from the yarn through trap wraps.

After 2 hours, no methanol was generated and the condensation was completed. Next, unreacted phenol was removed by distillation under reduced pressure to obtain 393 g of a phenol aralkyl resin having the structure of formula (a).

The composition of the obtained resin was measured by high performance liquid chromatography and found that n=0 was 60.3, n=1 was 24.3,
n=2 is 9.2, n=3 is 3.8, n≧4 is 2.
4 (mol%). In addition, the softening point of this resin (JI
S, ni-2548) was 45°C.

Next, 393 g of the obtained phenol aralkyl resin 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.

While stirring this mixture, the temperature was raised to 115-119°C, and at the same temperature, a 40% sodium hydroxide aqueous solution 275
g was added dropwise over 4 hours, the distilled water was continuously separated and collected, and the epichlorohydrin phase was returned to the reactor. After the dropwise addition is completed, the reaction is terminated by removing the distilled water.

After this, excess epichlorohydrin was distilled under reduced pressure, and the reaction product was purified as methyl isobutyl ketone (MIBK).
After filtering out sodium chloride and a slight excess of sodium hydroxide, the solvent was distilled off under reduced pressure to obtain 465 g of a yellow oily epoxy resin.

The epoxy equivalent of the resin is 227 g/eq, and the viscosity (according to Tokyo Keiki E-type viscometer) is 468 g/am -5
ec (35°C).

Usage Examples Liquid MDA (Ebicure Z; manufactured by Shell Chemical) was added as a curing agent to each of the epoxy resins obtained in Examples 1 to 3 and Comparative Example 1, and Epikote 828 (manufactured by Shell Chemical) introduced from bisphenol A. were mixed under the conditions shown in Table 1, and each mixture was cast and processed.
The mechanical properties of the cured resin after processing were measured.

The results are shown in Table-1. The results of the epoxy resins obtained in Examples 1 to 3 are shown as Experimental Examples 1 to 3, respectively.
Comparative Experiment Example 1 The results of the epoxy resin obtained in Comparative Example 1
The results of Epicote 828 (manufactured by Shell Chemical) are shown as Comparative Experimental Example 2.

(Notes on Table 1) ・Formulation・・・・Weight ratio・Geling time・・・According to JIS, Ni-6910・Heat distortion temperature・・・・・・・According to JIS, Ni-7207・Water absorption rate at boiling...Boiling at 100℃/2 hours・Bending strength...
・・Tensile strength according to JIS, Ni-7203・・・・
------- JTS, 2007-7113 (Effects of the Invention) As explained above, the epoxy resin of the present invention has a low molecular weight and is liquid or has a low melting point at room temperature, so it can be used with various curing agents. It has excellent compatibility, and operations such as blending, coating, and impregnation are extremely easy, and a homogeneous cured product can be obtained.The cured product has excellent mechanical properties such as impact resistance, water resistance, and oxidation resistance. It has excellent performance, especially in terms of tensile strength and elongation, and also has sufficient heat resistance.

The epoxy resin of the present invention, which has the above-mentioned advantages, can be expected to be used in various applications, particularly in the field of electronic materials, where such performance has long been desired.

[Brief explanation of the drawing]

FIGS. 1 to 3 are diagrams showing the IR analysis results (liquid film method) of the epoxy resins obtained in Examples 1 to 3. Patent applicant Mitsui Toatsu Chemical Co., Ltd.

Claims (1)

[Claims] 1) General formula (a) ▲ Numerical formula, chemical formula, table, etc. ▼ (a) (However, R^1 in the formula represents hydrogen or an alkyl group having 1 to 9 carbon atoms, R^2 represents an alkyl group having 1 to 9 carbon atoms, and n represents an integer of 0 to 5.) Obtained by reacting an alkylphenol aralkyl resin represented by the following with epihalohydrin in the presence of a hydrogen halide acceptor. Epoxy resin. 2) General formula (b) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(b) (However, R^3 in the formula represents a lower alkyl group having 4 or less carbon atoms.) α, α' -Dialkoxy-p-xylene has the general formula (c) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(c) (However, R^1 in the formula represents hydrogen or an alkyl group having 1 to 9 carbon atoms, R^2 represents an alkyl group having 1 to 9 carbon atoms.) The general formula (a ) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (a) (However, R^1 in the formula 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. (n is an integer of 0 to 5) and epihalohydrin are reacted in the presence of a hydrogen halide acceptor. Method of manufacturing resin.