JPS60262818A - Epoxy resin composition - Google Patents

Abstract

PURPOSE:The titled composition which can give a cured resion of excellent flexibility, prepared by mixing an epoxy resin with a specified prepolymer blocked with an oxime or a phenol. CONSTITUTION:An OH-terminated liquid diene polymer-isocyanate compound (a) having an isocyanato content of 0.1-30wt% (e.g., OH-terminated butadiene homopolymer/tolylene diisocyanate adduct) is mixed with a blocking agent such as an oxime or a phenol and the mixture is heated with agitation to obtain an oxime- or phenol-blocked component (a). An epoxy resin (A) such as bisphenol A-derived expoy resin is mixed with 1-30wt%, based on component A, blocked component (a) and, optionally, a viscosity controller (e.g., glycidlyl versatate) and a filler (e.g., silica), etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an epoxy resin composition, and more particularly to an epoxy resin composition that can provide a cured resin with excellent flexibility.

Epoxy resin has high strength, dimensional stability, chemical resistance,
It has excellent electrical properties and is widely used in cast products, electrical parts, adhesives, impregnation materials, sealing materials, etc.

However, as a characteristic of hard resin, the cured product is flexible (
toughness). Therefore, there were problems such as limitations in its use as an adhesive and the occurrence of cracks when used as an electrical component.

Therefore, various methods have been proposed to improve these drawbacks. For example, it is known to add a liquid diene polymer-isocyanate compound prepolymer having a hydroxyl group at the end as a modifier. However, when this modifier is added and an amine is used as a curing agent for an epoxy resin, a reaction occurs quickly between the isocyanate of the modifier and the amine, so the reactant oozes out of the system. Therefore, it was not possible to improve the quality sufficiently. Furthermore, when an acid anhydride curing agent is used, it also reacts with the hydroxyl group in the epoxy resin, resulting in the same inconvenience as above.

The present inventors have conducted extensive research to develop an epoxy resin composition that has no restrictions on the curing agent that can be used and eliminates the above drawbacks, and has found that it is effective to use a specific block form of the prepolymer. .

The present invention was completed based on this knowledge.

The present invention is an epoxy resin composition comprising an epoxy resin mixed with an oxime or phenol block of a liquid diene polymer-isocyanate compound prepolymer having a hydroxyl group at the end.

As the epoxy resin used in the present invention, bisphenol A
type, phenol novolac type5. aromatic ester type,
There are various types such as alicyclic ester types.

An oxime or phenol block of a liquid diene polymer-isocyanate compound prepolymer used as a modifier for epoxy resins has a hydroxyl group at the end. means something that has been done.

The above prepolymer has an isocyanate content of 0.1 to 3.
0% by weight is preferred. Examples of such prepolymers include tolylene diisocyanate adducts of hydroxyl-terminated butadiene homopolymers, 4,4'-diphenylmethane diisocyanate adducts of hydroxyl-terminated butadiene-acrylonitrile copolymers, and hexamethylene adducts of hydroxyl-terminated butadiene-styrene copolymers. Examples include diisocyanate adducts.

The oxime compound used to form the prepolymer block may be either an aldoxime or a ketoxime, such as formaldoxime 5-acetoxime and henzaldoxime.

In addition, examples of phenolic compounds include phenol, 0-cresol, m-cresol, p-cresol,
2.3-xylenol, 2,4-xylenol, 2,5
-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol.

Examples include p-5ec, -butylphenol, p-tert-butylphenol, resorcinol, and oxybenzene-p-sulfonic acid.

The reaction for obtaining a block body may be carried out by a conventional method of mixing the prepolymer and the blocked thorns and heating and stirring the mixture, and there is no need to set any special conditions.

The amount of the above blocks added to the epoxy resin is 1 to 3.
0% by weight, preferably 5-15% by weight. If this amount is less than the lower limit, flexibility cannot be imparted, and if it exceeds the upper limit, the properties of the epoxy resin, particularly the strength, will be reduced.

In the epoxy resin composition of the present invention, a reactive type such as persatic acid glycidyl ester,
There are non-reactive types such as dibutyl phthalate and solvent types such as xylene. In addition, silica,
Commonly used materials include calcium carbonate, talc, and mica.

A cured epoxy resin body is obtained by curing the epoxy resin composition. Curing reactions include aliphatic amines, aromatic amines, alicyclic amines, polyamide amines, tertiary amines, and imidazoles.

This may be carried out using a known curing agent such as a boron trifluoride compound or an acid anhydride, and the reaction temperature, 2 hours, etc. may be determined in consideration of the type of curing agent used.

The epoxy resin composition of the present invention can be used for various purposes such as casting and adhesion, and maintains the excellent physical properties inherent to epoxy resin and has improved flexibility.
Applications are expected to expand to fields that require flexibility (for example, laminates, insulating materials, etc.).

Next, the present invention will be explained by examples.

Examples 1 to 4 Bisphenol A epoxy resin (containing reactive diluent)
A predetermined amount (parts by weight) of an acetoxime block of a hydroxyl-terminated liquid rubber-tolylene diisocyanate prepolymer (NGO content 9.0% by weight) and a curing agent are blended into the mixture and a curing reaction is carried out to obtain a cured epoxy resin. I got it. In addition, in the case of Examples 1 to 3, the curing reaction was first carried out at 80'C for 2 hours.
Next, the test was carried out by heating at 150°C for 4 hours, and in the case of Example 4, the test was carried out by heating at 100°C for 1 hour. The physical properties of the cured product are shown in Table 1 along with the experimental conditions.

Comparative Examples 1 to 4 Examples 1 to 3 were carried out in the same manner as in Examples 1 to 3, except that the prepolymer block was not used or a prepolymer was used in place of the block.

The results are shown in Table 1.

Comparative Example 5 The same procedure as in Example 4 was carried out except that the prepolymer block was not used. The results are shown in Table 1.

*l Made by Shell Chemical, [Epicor #815J, epoxy equivalent 190 *2 Made by Shell Chemical, "Epicor"#828J, epoxy equivalent 190 *3 Made by Nippon Kayaku, [Kayahard A-BJ, liquid type, aromatic diamine *4 Manufactured by Shin Nippon Chemical, [Rikazid MH-700J, Methyl hexahydrophthalic anhydride *5 Triethylenetetramine $6 2.4.6-)li(dimethylaminomethyl)phenol *7 Liquid rubber-isocyanate prepolymer 7 Setoxime prosodic substance *8 Liquid rubber-isocyanate prepolymer (NGO
Content 9.0% by weight) *9 Hydroxyl group-terminated liquid rubber butadiene homopolymer (
OH equivalent 0.82meq/g) $10 JIS K
-Compliant with 6911, bending speed 2 cm/sin 120-

Claims (1)

[Claims] An epoxy resin composition comprising an epoxy resin mixed with an oxime or phenol block of a liquid diene polymer-isocyanate compound prepolymer having a hydroxyl group at the end.