JPS62246924A - Curable resin composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition which is suited as a matrix resin for FRP prepregs, a sealing agent for IC's, etc. and can give a cured article excellent in heat resistance and water resistance, by mixing a specified polyepoxy compound prereacted with an at most equivalent amount of a curing agent with a cyanate resin, etc. CONSTITUTION:9-2pts.wt. polyepoxy compound (A) having at least two epoxy groups in the molecule which is premixed with about 0.01-0.6 equivalent of a curing agent such as an aromatic amine and, if required, prereacted by heating is mixed with 1-8pts.wt. cyanate resin (B) comprising a mixture of a polycyanate having at least two isocyanate groups in the molecule, represented by formula I (wherein m is 2-6 and R is an aromatic organic group) or a mixture thereof with a prepolymer thereof (a) or a mixture of component (a) with a polymaleimide having at least two maleimide groups in the molecule, represented by formula II (wherein R' is a 2-6C aromatic or aliphatic organic group, X1-2 are each H, a halogen or an alkyl and n is m) and a prepolymer thereof.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a novel curable resin composition.

The cured resin product obtained by the present invention has excellent heat resistance and water resistance, and is particularly suitable for use as an IC sealant for matrix resins for prepregs of fiber-reinforced plastics (hereinafter abbreviated as FRP).

[Prior Art] Among curable resins, epoxy resins are widely used in various industrial fields due to their excellent mechanical properties. In particular, epoxy resins are often used in advanced composite materials consisting of reinforcing fibers such as carbon fibers, glass fibers, and aramid fibers and matrix resins, and in IC sealants. However, the epoxy resins used in these composite materials and IC sealants still have some unsatisfactory points, which limits their applications and usage methods.

One of them is heat resistance and water resistance. In order to improve heat resistance and water resistance, various curable resins other than epoxy resins have been used as matrix resins and sealants. Among these, cured products of cyanate ester resins have been known to provide cured products with excellent heat resistance and water resistance. However, these cured products are brittle and have poor toughness, so advanced composite materials using them as matrix resins lack impact resistance and cannot fully express the strength of reinforcing fibers. The drawback was that it was prone to cracking.

In order to improve the toughness of these cured products, a method of adding an epoxy resin is known. In this case, the greater the amount of epoxy resin added, the higher the toughness, but the glass transition temperature (
Since T(+>) decreased, it was necessary to add a new curing agent for the epoxy resin.The curing agent used is generally an aromatic amine in consideration of heat resistance.

These resin compositions are disclosed in, for example, JP-A-60-250026.
This is a well-known method as shown in . However, when a composition is created by mixing these components, it has the drawback of high reactivity with polyfunctional cyanate esters and aromatic amines and a short pot life, so it cannot be used as a matrix resin for prepregs or as a sealant. It was difficult.

Various other methods of improving toughness are also being investigated. For example, one in which a modified butadiene resin into which a meth (acryloyl) group has been introduced is blended into a cyanate ester resin composition (JP-A-57-153045), one in which a butadiene-acryloni-1 to silyl copolymer is added. (Japanese Unexamined Patent Publication No. 57-153046), or those in which an epoxy resin is further added (Japanese Unexamined Patent Publication No. 56-157424)
．． , .

56-157425) and the like are known.

However, all of these methods inevitably suffer from a decrease in heat resistance and water resistance.

[Problems to be Solved by the Present Invention] The purpose of the present invention is to add an epoxy resin to a cyanate ester resin in order to improve its toughness, and to improve the glass transition temperature (Tg
) To provide a curable resin composition whose usable life does not become short even when a new epoxy resin curing agent is added to prevent a decrease in epoxy resin composition.

[Means for solving the problem] As a result of intensive studies, the present inventors prepared an epoxy resin that had been pre-reacted with an equivalent amount or less of a curing agent, and prepared an epoxy resin that was pre-reacted with an equivalent amount or less of a curing agent. By reducing the concentration of cyanate ester resin to a level that does not adversely affect the pot life, the cyanate ester resin can be cured without shortening the pot life even when a resin composition containing an epoxy resin curing agent is created. The inventors have discovered that it is possible to provide a synthetic resin composition, leading to the present invention.

That is, in order to achieve the above object, the present invention has the following configuration.

Curable resin composition A containing at least the following components; Polyepoxy compound B having at least two or more epoxy groups in one molecule, which has been pre-reacted with a curing agent below the melting point; Cyanate ester type Resin Most polyepoxy compounds can be used without any restrictions in the present invention. Particular examples include liquid or solid bisphenol A epoxy resins such as Epicote 82B, Epicote 1001 (manufactured by Yuka Shell Epoxy Co., Ltd.), DER-331 (manufactured by Dow Chemical Japan Co., Ltd.), 21M434. ELMI 20 (
Manufactured by Sumitomo Chemical Co., Ltd., YH-434 (manufactured by Tobu Kasei Co., Ltd.), MY
Glycidylamine type epoxy resin such as -720 (manufactured by Chill Geigy), phenolic Fff epoxy resin such as Epiclon 830 (manufactured by Dainichi Ink Chemical Co., Ltd.), Epicort 152. Phenol novolak type epoxy resins such as Epicote 154 (manufactured by Yuka Shell Epoxy Co., Ltd.), Epiclon 152 (manufactured by Dainippon Ink Chemical Industries, Ltd.)
Brominated bisphenol A type epoxy resins such as E
Examples include cresol novolac type epoxy resin such as SCN-220 (manufactured by Sumitomo Chemical Co., Ltd.), other bisphenol St epoxy resins, and alicyclic epoxy resins.

These polyepoxy compounds may be used alone or in a mixture of several types without any problem.

Further, as the curing agent used in the preliminary reaction, any general curing agent for epoxy resins can be used, but as mentioned above, aromatic amines are preferable from the viewpoint of heat resistance when considering the purpose of the present invention. Examples include phenylene diamine, diaminodiphenylmethane, diaminodiphenylsulfone, diaminodiphenyl ether, and the like.

If the amount of these curing agents is added up to an equivalent amount, it tends to cause gelation and is thermally unstable, so it is necessary to keep the amount below this amount, but if the amount is too small, the effectiveness will be reduced. The amount is preferably about 0.01 to 0.6 equivalents, more preferably about 0.1 to 0.4 equivalents of the polyepoxy compound used.

Preliminary reaction is achieved by simply adding a curing agent to the polyepoxy compound and leaving it for a certain period of time, but in reality, an efficient method of accelerating the reaction to some extent by heating is essential.

Further, the polyfunctional cyanate ester in component B is a compound having two or more cyanate ester groups, and preferably the cyanate ester is a compound represented by the following general formula (1).

R-(0-C3N)lTl
...1) (In the formula, m must be an integer of 2 or more and 6 or less, R is an aromatic right acid group, and the cyanate ester group is bonded to the aromatic ring of the right acid group R. Specifically, dianatobenzene, tricyanatobenzene, cyyanatonaphculene, 1-lycyanatonaphthalene, diaminodiphenyl, bis(cyanatophenyl)methane, bis(cyanato-phenyl)propane, bis Examples include (cyanatophenyl)ether, bis(cyanatophenyl)sulfone, and cyanate ester obtained by reaction of novolac with cyanogen halide. It can also be used as a prepolymer obtained by polymerizing these polyfunctional cyanate esters in the presence of a catalyst such as a Lewis acid, a salt such as sodium carbonate, or lithium chloride.

Moreover, the polyfunctional maleimide is a compound represented by the following formula (2)-11.

(In the formula, R- is an aromatic or aliphatic acid group of 2 or more and 6 or less, x and x2 are hydrogen, halogen, or an alkyl group, and n is an integer of 2 or more and 6 or less. ) The maleimide represented by the above formula is obtained by reacting maleic anhydride with a polyamine having 2 to 6 amino groups to prepare maleamic acid, and then performing a dehydration reaction. The polyamine to be used is preferably an aromatic polyamine from the viewpoint of heat resistance, but an aliphatic amine may be used if flexibility and softness are desired to be imparted to the resin. Suitable amines include:
Examples include phenylene diamine, xylylene diamine, cyclohexane diamine, diaminodiphenyl, diaminodiphenylmethane, diaminodiphenyl ether, diaminodiphenyl sulfone, and the like. Also used are condensation products of maleimide and these amines.

The mixing ratio of component A and component B varies depending on the type of compound used, but generally A:B is 9:1 to 2:8.
is within the range of

When the curable resin composition of the present invention is used as a matrix resin for FRP prepreg, it is possible to obtain a prepreg with excellent tack drapability and good moldability. Moreover, the cured product of this prepreg provides a molded product with high toughness.

As reinforcing fibers, carbon fibers, glass fibers, aramid fibers, boron fibers, or hybrids thereof can be used. Moreover, any shape can be used, such as a tape arranged in a certain direction, a sheet-like material, a mat-like material, a woven material, etc.

When used as an IC encapsulant, it becomes a cured product that has excellent bt properties and is resistant to cracks and has excellent heat resistance and water resistance.

Furthermore, various additives such as fillers, curing accelerators, and diluents can also be used in the resin composition of the present invention as long as the properties are not impaired.

[Function] The present invention involves preparing an epoxy resin that has been pre-reacted with a curing agent of less than the caulking level, and adjusting the concentration of amines that are highly reactive with polyfunctional cyanate esters to an extent that does not adversely affect the pot life. By adding a cyanate ester resin after the cyanate resin has been reduced to
It has now become possible to provide a curable resin composition that provides a cured product with excellent water resistance.

[Example] The present invention will be explained in further detail by the following example. The amounts of each component in the examples represent fffffi parts, and the contents of the resin are as follows.

Epoxy resin A; tetraglycidylamino diphenylmethane, 21M434 (manufactured by Sumitomo Chemical Co., Ltd.) Epoxy resin B
; Bisphenol A epoxy resin, Epicote 828
(Manufactured by Yuka Ciel Epogishi Co., Ltd.) 8 resin: 2.2'-bis(4-cyanatophenyl)
Resin composition of a preliminary reaction product of propane and bis(4-maleimi!-phenyl)methane with a composition ratio of the former to the latter of 9:1, 8cho-2160 (manufactured by Mitsubishi Gas Chemical Co., Ltd.) Example 1 Epoxy resin A100 weight 5 parts of diaminodiphenylsulfone (DDS) was added to the mixture and pre-reacted at 130'C for 1 hour. After cooling to 2+M 80'G, 100 parts of BT resin was added to obtain a resin composition. This cured glass When the transition temperature (Tg) was measured using a differential scanning calorimeter, it was 210'C, indicating that the cured product had high heat resistance.

Example 2 Diaminodiphenylsulfone (DDS>10 parts) was added to 100 parts by weight of epoxy resin B, and pre-reacted at 130°C for 1 hour. After that, it was cooled to 80°C and BT resin 1
00 parts were added to obtain a resin composition.

This resin composition was cast and cured at 180'C for 2 hours to obtain a cured product.

The glass transition temperature (Tg) of this cured product was measured with a differential scanning calorimeter and was 205°C, indicating that it was a cured product with high heat resistance.

Comparative Example 1 A resin composition was obtained in the same manner as in Example 1 except that the step of adding DDS and pre-reacting was removed. This resin composition was cast and cured at 180°C for 2 hours to obtain a cured product.

When the glass transition temperature (TC+>) of this cured product was measured using a differential scanning calorimeter, it was 185°C, indicating that the heat resistance was considerably lower than that of Example 1.

Comparative Example 2 A resin composition was obtained in the same manner as in Example 2 except that the step of adding DDS and performing a preliminary reaction was removed. This resin composition was cast and cured at 180°C for 2 hours. 'A cured product was obtained.

When the glass transition temperature (T(+) > of this cured product was measured with a differential scanning calorimeter, it was 170° C., which showed that the heat resistance was considerably lower than that of Example 1.

Example 3 The resin composition obtained in Example 2 was left at air temperature for two weeks, but there was no significant change other than a slight increase in viscosity, and it was fully usable.

Comparative Example 3 A resin composition was obtained in the same manner as in Example 2 except that DDS was added at the very end instead of being subjected to a kitten reaction.

The resulting resin composition was left at air temperature for two weeks, but it became hard and had poor fluidity, making it unusable.

Example 4 When the cast resin plate obtained in Example 1 was cut out and its tensile properties were measured, the elongation at break was found to be 3.5%. When the cast resin plate obtained in Example 2 was similarly cut out and its tensile properties were measured, the elongation at break was 4.5%.

Comparative Example 4 When a casting resin was prepared using only 8-piece resin and its tensile properties were measured, the elongation at break was 1.5%, and compared to Example 4, it was found to be brittle and considerably lacking in flexibility.

Claims (2)

[Claims] (1) Curable resin composition A containing at least the following components; Polyepoxy compound B having at least two or more epoxy groups in one molecule and pre-reacted with an equivalent or less amount of curing agent; Cyanic acid Ester resin (2) The cyanate ester resin of component B is (a) a mixture with a polyfunctional cyanate ester containing two or more cyanato groups in one molecule or a prepolymer thereof, or (b) a molecule with (a). A curable resin composition according to claim 1, comprising a polyfunctional maleimide containing two or more maleimide groups therein, and a mixture thereof with a prepolymer.