JPS61130329A - Epoxy resin composition - Google Patents

Abstract

PURPOSE:The titled composition excellent in resistances to heat, moisture and chemicals, containing an epoxy resin obtained by reacting a phenol novolak resin with a glycidyl ether forming agent. CONSTITUTION:2,6-Dimethyl-4-methylolphenol obtained by reacting 2,6-xylenol with formaldehyde in the presence of a basic catalyst is reacted with a phenol or an alkylbenzene in the presence of an acidic catalyst to obtain a trinuclear or tetranuclear phenol novolak resin of formula I (wherein R is H, a halogen, phenyl or a 1-4C alkyl, n is 2-3, and m and p are each 0-3). This resin is reacted with 2-10mol, per OH group in the resin, glycidyl ether forming agent (e.g., epichlorohydrin) at 20-120 deg.C in the presence of a basic catalyst in an amount equivalent to or somewhat excess of the OH groups to obtain an epoxy resin of formula II. This resin is mixed with, if necessary, another epoxy resin, a polyamine, etc., to obtain the titled curable composition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a new and useful epoxy resin composition. It contains as an essential component an epoxy resin obtained using Nozelac resin). In particular, it concerns a curable epoxy resin composition with excellent heat resistance and moisture resistance.Epoxy resin, which is an essential component of the resin composition, is also used as an electrical insulating material due to its excellent heat resistance and moisture resistance. It is widely used as a heat resistance imparting agent for electrical insulating materials and as a resin for sealing ICs. As such, it is used as a next-generation epoxy resin, and the industrial application fields of the composition of the present invention are extremely wide-ranging.

[Prior art and problems to be solved by the invention] Examples of this type of epoxy resin having 1c3 or 4 phenylglycyl sol ether structures in the molecule include tris ( Epoxy resin made from (hydroxyphenyl)methane [Epoxy Technology Association lecture abstracts,
p. 16, "Epoxy Resins - Recent Advances" (published April 25, 1980)] and epoxy resins made from tetra(hydroxyphenyl)ethane represented by the following structural formula % formula % ["Epoxy resin".

Page 14 (published by Nikkan Kogyo Shimbun, Inc., January 1, 1964)] are well known.

These epoxy resins mentioned above all have high heat distortion temperatures and thermal oxidative stability.

On the other hand, there are the following manufacturing difficulties.

For example, the latter resin mentioned above is obtained by reacting phenol with glyoxol under an acidic catalyst to synthesize tetra(hydroxyphenyl)ethane, which is then glycityl etherified with shrimp chlorhydride. The relationship between the molar ratio of phenol and glyoxol and the purity of the intermediate tetra(hydroxyphenyl)ethane is as follows.

As can be seen from this result, even if a large excess of phenol is used, the purity of tetra(hydroxyphenyl)ethane obtained is only less than 70%, and it is difficult to expect higher purity.

Next, when each of the epoxy resins represented by the above general formulas [11) and CIII) is cured with anhydride or phenol black resin, although it has good heat resistance, the water absorption rate is lower than that of the conventional one. There is almost no difference from the Tsumerac type epoxy resin, and it is not possible to reduce the diffusion of water in the cured resin.

This means that electrical properties, especially volume resistivity when humidity is high, have not been improved.

In this way, 7 enolno with only trinuclear or tetranuclear bodies?
Lac resin can be efficiently produced and its purity can be easily increased, and at the same time it can be obtained by glycidyl etherification of such phenolic black resin. As long as conventional techniques are followed, there are limits to improving the cured physical properties, especially the moisture resistance, of so-called Tsumerac type epoxy resins.

[Failure to solve the problem]

However, as a result of intensive studies in view of the various drawbacks of the prior art as described above, the present inventors have found that 2.
Using 6-xylenol as a raw material, in the presence of a basic catalyst,
2,6-nomethyl-4- by reacting with formaldehyde
Methylolphenol (3,5-trimethyl-4-hydroxy-benzyl alcohol) is synthesized and then reacted with phenols or alkylbenzenes in the presence of an acidic catalyst to produce a trinuclear or tetranuclear 7-enol novolak. It was discovered that a Tumerac type epoxy resin having both high heat resistance and moisture resistance could be obtained by obtaining a resin and then glycityl etherifying it with shrimp chlorohydrin. Completed.

That is, it substantially contains an epoxy resin represented by the following general formula % as an essential component. The object of the present invention is to provide a curable epoxy resin that has particularly excellent heat resistance and moisture resistance.

Here, the epoxy resin represented by the general formula is prepared according to a conventional method.

In other words, the phenol nogelac resin represented by the general formula and the so-called glycidyl etherifying agent may be reacted in the presence of a basic catalyst. It is obtained by condensing xylenol resol, that is, 2,6-nomethyl-4-methylolphenol, and phenols or alkylbenzenes in the presence of an acidic catalyst. 0-Daresol for things. p-cresol, 2,3-xylenol.

2.5-xylenol, 2,3.5-trimethylphenol, 2-ethylphenol, 4-ethylphenol, 2-butylphenol, 4-butylphenol, resorcinol, phenol, 4-phenylphenol, m-cresol, 3,5- Xylenol.

Examples include 3-ethylphenol, 2-phenylphenol, and 2-bromophenol. On duty.

Such phenols include 0-cresol or 3,
5-xylenol is preferred.

Typical examples of the alkylbenzenes mentioned above include p-xylene, durene, and mectylene, among which mesitylene is preferably used. Epichlorohydrin.

Among these are epibromohydrin and mixtures thereof, the use of epichlorohydrin is particularly preferred.

In preparing the epoxy resin, the phenol nogilac resin as mentioned above is added in advance in an amount of about 2 to 2 to 100 ml per hydroxyl group contained in the phenol black resin.
10 mol of suspended glycysol etherification agent as it is, or acetone containing this glycysol etherification agent,
In the form of a solution to which a water-soluble solvent such as l-prononol or methanol is added, and after further purging with nitrogen if necessary, an amount equivalent to one hydroxyl group in the phenol black resin as mentioned above is prepared. 5 or a slightly excess amount of a basic catalyst in the form of a solid or highly concentrated aqueous solution, the reaction is carried out in a temperature range of 20 to 120°C, and water and salts produced as by-products are removed. A target resin having a structure represented by formula [I] is obtained.

Typical basic catalysts mentioned above include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, or potassium hydroxide, and alkali metal salts such as sodium silicate or sodium aluminum/acid. There is.

On the other hand9. Typical #R catalysts include inorganic acids such as hydrochloric acid or sulfuric acid, and organic acids such as oxalic acid.

The epoxy resin of the present invention obtained by this process may be used, if necessary, with other known and commonly used epoxy resins, such as polyglycyl ethers of polyhydric phenols or polyhydric alcohols, epoxy resins, etc. fatty acids,
It can be mixed with epoxidized diene (co)polymers or cyclohexene epoxide conductors to form a composition.

In addition, the epoxy resins used in the present invention include aliphatic polyamines, alicyclic polyamines, aromatic polyamines, glycidyl ethyl-I lyamine adducts, and polyamides, as well as commonly used bisphenol-based epoxy resins. , acid anhydrides, Friedelkrach-type metal halides or phenol-formaldehyde (
It is also possible to form a composition by mixing a condensate (initial stage).

By doing so, it can be used in a wide range of applications such as electrical equipment and construction and civil engineering, such as paints, adhesives, impregnation agents, sealants, or molding materials.

Furthermore, the niboxy resin used in the present invention can be modified by reacting with a conventional niboxy modifier, and by forming a composition in such a form, it can be used in a wider range of applications.

Next, the present invention will be explained in detail with reference to Reference Examples and Examples. In the following, unless otherwise specified, all terms "weight %" are meant.

Reference Example 1 (Example of preparation of 2,6-dimethyl-4-methylolphenol) 1221t of 2.6-xylenol 110 of Kyzyrol
Add 10511 of aqueous 30 thiformaldehyde and heat to 40°C. Then,
108I in an aqueous solution of 33thiodium hydroxide under stirring,
Add it so that the temperature in the system gradually increases to 60℃,
The mixture was heated to a formaldehyde concentration over a period of 5-8 hours. That is, the reaction was continued at 60° C. until the amount of formaldehyde remaining was 1.2%.

Thereafter, approximately 90.9% of 50 sulfuric acid was mixed to adjust the - to 4.5-4.8, and the aqueous layer was allowed to stand to separate and then washed twice with water to obtain the desired compound. A solution of quijirol was obtained.

Reference Example 2 (Preparation Example of Nogelac Type Epoxy Resin) 108. P
of 0-cresol was added, an additional 10 I of oxalic acid was added, and the mixture was kept under reflux for 3 hours to continue the reaction.

Distillation is then continued until approximately 36.9' of the aqueous phase is separated from the reaction mixture, which has been raised to 190° C. under reflux cooling of the quidroll, and there is no more water, then first under atmospheric pressure and then slowly distilled. Under reduced pressure (30swHg) VC
Distillation was continued until the temperature (inner temperature) of the reaction mixture reached 210°C. Both distillation operations took a total of 2 hours.

Then, 190'cVC was cooled to 7. /-
A lunogolak resin was obtained, and the free cresol content in this lunogolak resin was less than 0.0s %, but no free 2,6-xylenol was observed.

The Norac resin obtained here has the following structure 2
-Methyl-4,6-bis(3,5-dimethyl-4-hydroxybenzyl)phenol, a trinuclear compound.

Next, epichlorohydrin of 125IIK925I of this Nogirak m fat was added, and while stirring while boiling, 105N of 48% sodium chloride aqueous solution was added dropwise over 2 hours, during which time water was removed from the system to stop the reaction. I forced him to continue.

Thereafter, the sodium chloride was removed from each room and the mother liquor was concentrated to obtain a pale yellow target resin.

The epoxy equivalent of the Nogelac type epoxy resin obtained here is 191, which is 6. Hereinafter, it will be abbreviated as resin (1).

Reference Example 3 (same as above) Xylo-ILt-soluble fiK containing 4 ssl of 2,6-nomethyl-4-methylolphenol obtained in Reference Example 1
, 122 g of 3,5-xylenol was added.

Furthermore, oxalic acid 151 was added and the reaction was continued by boiling under reflux for 6 hours.

It was then subjected to azeotropic dehydration with quijirole and the reaction was continued to 190° C. until about 541 aqueous layers were separated.

After that, firstly, Kijirole was distilled and recovered under normal pressure, and then the reaction was continued under reduced pressure of 30'wHg until the reaction temperature reached 230C&C, and then cooled to 200C) to obtain a novolak resin of 524.9. Ta.

The novolac resin obtained here is 3,5-dimethyl-2
, 4,6-tris(3,5-dimethyl-4-hydroxybenzyl)phenol.

Next, 925y of epichlorohydrin was added to 1311 of this novolac resin, and 105.9 of a 48 sodium thihydroxide aqueous solution was added dropwise over 2 hours while stirring the mixture. During that time, water was removed from the system.

After that, sodium chloride was removed from the reaction mixture,
On the other hand, the mother liquor is concentrated and turns pale yellow. Epoxy equivalent is 20
A target resin of 0 was obtained. Hereinafter, it will be abbreviated as resin (2).

Reference example 4 (same as above) 2.6--/45 of methyl-4-methylolphenol
Add 1201 of mesitylene to the quizyrol solution containing 61, and then add 100.9 of Vc98 thiosulfuric acid to make 8.
React for 4 hours at 0°C, then cool and neutralize with an aqueous solution of 48 sodium hydroxide in 1701, then separate the aqueous layer to give 1,3,5-trimethyl-2,4,6 of 3921. -) Lis(3,5-)7'thyl-4-hydroxypennol)benzene novolak resin was obtained.

Next, 6001 epichlorohydrin was added to 174y of this novolac resin, boiled and stirred until 105.
A 48% sodium hydroxide aqueous solution of F was added dropwise over 2 hours,
During that time, water was removed from the system.

Then, while sodium chloride was removed from the reaction mixture, methyl ingthyl ketone (MIBK) was dissolved in the mother liquor, washed with water, and the MIBK was recovered to obtain a target resin having an epoxy equivalent of 255. Below, resin (
3).

Examples 1 to 3 and Comparative Example 1.2 10 of each epoxy resin obtained in Reference Examples 2 to 4
0 parts, methyl nadic anhydride (MAN
) and N,N-dimethylbenzylamine (BD) as a curing accelerator in a blending ratio as shown in Table 1,
The composition of the present invention was prepared by mixing at a temperature of 70°C.

Next, each composition was degassed under a reduced pressure of 10 ram Kg for 10 minutes, then injected into a mold for manufacturing a casting plate and precured at 80°C for 3 hours, and then It was completely cured at 150°C for 3 hours and then at 200°C for 3 hours.

For comparison, "Epicron N-680J (0-cresol Norac type epoxy resin manufactured by Inu Nippon Ink Chemical Industry Co., Ltd.; epoxy equivalent = 2201) and "Epiclon N-740J (phenol/) Melac manufactured by Inu Nippon Ink Chemical Co., Ltd. A casting plate was obtained in the same manner as in each Example of the present invention except that a mold epoxy resin (epoxy equivalent = 210) was used.

When the physical properties of each cast plate were evaluated, the results shown in the table were obtained.

〔Effect of the invention〕

The composition of the present invention owes much to the epoxy resin that constitutes it, and has the following characteristics.

■ High heat distortion temperature, ■Low water absorption rate and ■Good chemical resistance.

The physical properties of this Fy4m product are different from that of conventional phenol.
This is not possible with novolac type epoxy resins or O-cresol novolac type epoxy resins.

Claims (1)

[Claims] Necessary components include substantially general formulas▲mathematical formulas, chemical formulas, tables, etc.▼ ・・・・・・・・・[I] [However, R in the formula is a hydrogen atom or a halogen It represents an atom or a phenyl group or an alkyl group C_1 to C_4, n is an integer of 2 or 3, and m or p is an integer of 0 or 1 to 3, respectively. ] A curable epoxy resin composition comprising the epoxy resin shown below.