JPS62177016A - Epoxy resin composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition curable at low temperatures in a short time, outstanding in adhesivity to carbon fiber, by blending tetraglycidyl diaminodiphenylmethane, m-phenylenediamine, diaminodiphenylmethane and specific two kinds of addition reaction products. CONSTITUTION:The objective composition can be obtained by blending (A) N,N,N',N'-tetraglycidyl diaminodiphenylmethane, (B) m-phenyulenediamine, (C) 4,4'-diaminodiphenylmethane, (D) an addition reaction product from 4,4'- diamonodiphenylmethane and monoepoxy compound, and (E) a second addition reaction product from m-phenylenediamine and monoepoxy compound. The amounts of the components B-E to be used are preferably such that the equivalent ratio of the amino plus imido groups to the epoxy group in the component A falls between 0.8 and 1.1, respectively. The weight ratio of the components B plus C to the components C plus E is pref. 50:50-80:20.

Description

Detailed Description of the Invention "Field of Industrial Application" The present invention relates to a new epoxy resin composition, and more specifically to a fiber that cures at low temperatures and in a short time and has excellent adhesion to reinforcing fibers, especially carbon fibers. The present invention relates to epoxy resin compositions for reinforced plastics.

"Prior Art and Problems" Conventionally, epoxy resins have been mainly used as resins for composite materials using carbon fibers. Among these, when used in aviation, space, etc., resins with high heat resistance and good adhesion to carbon fibers are required. N is a resin that satisfies such requirements.

A resin composition comprising N,N',N'-tetraglycidyldiaminodiphenylmethane and diaminodiphenylsulfone is known (Japanese Patent Publication No. 55-25217).
. However, the above formulation using diaminodiphenylsulfone as a curing agent has the disadvantage that curing requires a high temperature and a long time, and productivity for obtaining molded products is poor. Furthermore, as a measure of the adhesion between carbon fiber and resin, the glabella shear strength (hereinafter abbreviated as ILSS) of the molded body is usually determined as 1jtl + N, N, N', N'
- In the above composition comprising tetraglycidyldiaminodiphenylmethane and diaminodiphenylsulfone, I
A resin having an L SS of less than 13 kBl m rd and a high ILSS is desired.

"Means for Solving the Problems" In view of the above circumstances, the object of the present invention is to provide an epoxy resin composition that cures at low temperatures and in a short time, has high heat resistance, and has excellent adhesiveness to carbon fibers. There is a particular thing.

That is, the present invention comprises the following components (A), (B), (C), (
Epoxy resin composition characterized by consisting of D) and (E) (A) N, N, N', N'-tetraglycidyldiaminodiphenylmethane, (B) m-phenylenediamine, (C) 4.4' -diaminodiphenylmethane, (D
) 4.4'-Diaminodiphenylmethane and a monoepoxy compound, and (E) m-phenylenediamine and a monoepoxy compound.

N as component (A) that can be used in the present invention
.
It is commercially available under the trade name "Araldite MY-720".

Component (D) and component (E) of the present invention are each 4° 4° −
By mixing diaminodiphenylmethane and m-phenylenediamine with a monoepoxy site at a temperature of room temperature to 100°C and reacting it (M). However, the use of phenyl glycidyl ether is particularly preferred.

The amount of components (B) to (E) to be used is such that the sum of the N-H groups of the amino groups is 0.5 to 1.5 with respect to the epoxy group of component (Δ).
The equivalent should be determined, more preferably in the range of 0.8 to 1.1 equivalent. The blending ratio of components (B) to (E) is not particularly limited, but (B) + (C)
: (D) + (E)=30 : 7
The effects of the present invention are more effectively exhibited within the range of 0 to 90:10 (weight ratio). More preferably, (B)+
(C): (D)+(E)=50: 50~8
The weight ratio is in the range of 0:20 (weight ratio).

A solvent and a curing accelerator may be added to the composition of the present invention depending on the purpose. Further, other epoxy resins such as bisphenol A type epoxy resins and novolak type epoxy resins may be added as long as the effects of the present invention are not lost.

The resin composition of the present invention can be applied to molding methods commonly used for molding carbon fibers. For example, it can be applied to a method of creating prepreg sheets, laminating them and molding them, filament winding molding, pultrusion molding, resin injection molding, etc.

The resin composition of the present invention can be used for structural materials such as aircraft and automobiles, and sports equipment such as golf shafts, tennis rackets, and fishing rods by taking advantage of the above-mentioned suitability.

"Examples" The present invention will be described below using specific examples, but the present invention is not limited to these examples.

Example 1 27 parts of m-phenylenediamine, 4. 45 parts of 4'-diaminodiphenylmethane, 13 parts of a 1:1 (molar ratio) adduct of m-phenylenediamine and phenylglycidyl ether, and 1:1 (molar ratio) adduct of 4,4'-diaminodiphenylmethane and phenylglycidyl ether. 15 parts were mixed into a homogeneous formulation (denoted as curing agent X).

100 parts of N,N,N',N'-tetraglycidyldiaminodiphenylmethane (120 parts of epoxy);
31 parts of the above curing agent X were mixed and diluted with acetone to prepare a dope having a viscosity of 70 centipoise at room temperature.

The above dope was applied to carbon fiber (manufactured by Toho Bethlon Co., Ltd., "HT-6").
000J) and aligned in one direction, the solvent was removed by air drying, and then heated at 130°C for 10 minutes to create a prepreg.

The obtained prepreg was cut into 20 cm square pieces,
Laminated 5 sheets using a matte die mold at 130℃, 7kg/
After curing for 30 minutes at CD pressure, after-curing was performed at 170° C. for 1 hour.

The carbon fiber content of the molded product was 59%. The molded product was measured for bending strength and flexural modulus according to JT SK7203, and glabellar shear strength according to ASTM-D-2344. The measured values obtained are shown in Table 1.

Example 2 20 parts of m-phenylenediamine, 35 parts of 4.4'-diaminodiphenylmeth, 1=1 (molar ratio) adduct of m-phenylenediamine and phenylglycidyl ether 2
0 parts and 4.4" -1=1 (molar ratio) adduct of diaminodiphenylmethane and phenylglycidyl ether 2
5 parts were mixed into a homogeneous formulation (designated hardener Y).

Mix 100 parts of N, N, N'', N''-tetraglycidyldiaminodiphenylmethane and 32 parts of the above curing agent Y,
Thereafter, a molded product was obtained in the same manner as in Example 1. Table 1 shows the bending strength, bending elastic modulus, and glabella shear strength of the molded product obtained.

Comparative Example I 100 parts of N,N,N',N'-tetraglycidyldiaminodiphenylmethane, 31 parts of 4,4'-diaminodiphenylsulfone, and 1.5 parts of BF3.monoethylamine complex were mixed and the same method as in Example 1 was carried out. A molded product was obtained. However, the pressing conditions were 150° C., 17 kg/c barge, and 30 minutes, followed by after-curing at 200° C. for 2 hours. The bending strength, bending modulus,
Table 1 shows the interlaminar shear strength.

Table 1 "Action/Effect" By using the composition of the present invention, it cures at low temperature in a short time, has excellent strength at high temperature, and has I LSS of N, N, N'
, N'-tetraglycidyldiaminodiphenylmethane and diaminodiphenyl sulfone can yield higher carbon fiber reinforced molded products.

Claims (1)

[Claims] 1. The following components (A), (B), (C), (D) and (
E) An epoxy resin composition comprising: (A) N,N,N',N'-tetraglycidyldiaminodiphenylmethane, (B) m-phenylenediamine, (C) 4,4'-diaminodiphenylmethane, (D) 4
, 4'-diaminodiphenylmethane and a monoepoxy compound, and (E) an addition reaction product of m-phenylenediamine and a monoepoxy compound. 2. The composition according to claim 1, wherein the monoepoxy compound is phenylglycidyl ether.