JPS6284114A - Epoxy resin composition for reinforcing with carbon fiber - Google Patents

Abstract

PURPOSE:The titled resin composition, containing a glycidyl derivative of a polyalkenylphenol and having improved heat resistance and composite characteristic as a reinforcing material for composite materials. CONSTITUTION:A composition obtained by incorporating (A) a glycidyl derivative of a polyalkenylphenol, e.g. poly-p-glycidyl-oxystyrene, with (B) an epoxy curing agent, particularly preferably diaminodiphenyl sulfone, and (C) a curing accelerator, e.g. BF3-amine complex compound. 0.5-1.5 equivalents, based on the glycidyl groups, component (B) is preferably used and 0.1-5.0wt%, based on the component (A), component (C) is preferably used.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an epoxy resin composition for reinforcing carbon fibers that has excellent heat resistance and composite properties.

Carbon fiber is lightweight, yet has high strength and high elasticity, so it has attracted attention as a reinforcing material for composite materials, and is widely used in sports, leisure goods, aircraft, etc.

(Conventional technology and problems) Conventionally, when carbon fiber is used as a reinforcing material, various epoxy resins are used as the matrix resin, but these epoxy resins have problems because they have insufficient heat resistance and composite properties. was there.

(Means and Effects for Solving the Problems) The present inventors conducted intensive research on matrix resins having excellent heat resistance and composite properties, and arrived at the present invention.

That is, the present invention is an epoxy resin composition for reinforcing carbon fibers containing a glycidylated polyalkenylphenol. Furthermore, a conventionally known epoxy resin may be used in combination with the glycidylated product described above. The present invention also provides an epoxy resin composition prepared by adding an epoxy resin curing agent and a curing accelerator to the glycidylated product (a).

Glycidylated polyalkenylphenols can be easily obtained by glycidyl etherification of polyalkenylphenols with epihalohydrin. Any polyalkenylphenol can be used, but examples include polyvinylphenol, poly-n-propenylphenol, poly-isopropenylphenol, poly-n
- Futhynylphenol, poly sec-butenylphenol.

Polytertiary butenylphenol and the like. Further, these polyalkenylphenols may have a phenol nucleus substituted with a halogen or an alkyl group. Any degree of polymerization of polyalkenylphenol can be used, but
In particular, the degree of polymerization is 5 to lo.

O is preferable. If the degree of polymerization is less than 5, the heat resistance will not be sufficient, and if the degree of polymerization exceeds 100, the softening point of the glycidylated polyalkenylphenol will be too high, making it difficult to handle. be.

In the present invention, a glycidylated polyalkenylphenol can be used alone, but if necessary, a conventionally known epoxy resin can also be used in combination. Epoxy resins that can be used in combination are not particularly limited, but examples include bisphenol A epoxy resin, bisphenol F epoxy resin, glycidylated novolac resin, glycidylated -0-cresol novolak resin, tetraglycidyldiamino-diphenylmethane, and triglycidyl-m. -7 minophenol, phthalic acid diglycidyl ester, etc.

The composition of the present invention comprises a) a glycidylated polyalkenylphenol, b) an epoxy resin curing agent, and C) a curing accelerator. As the epoxy resin curing agent, any conventionally known epoxy resin curing agent can be used. Examples include methylnadic anhydride, tetrahydrophthalic anhydride, phenol novolak, poly-p-vinylphenol, diaminodiphenylmethane, and diaminodiphenylsulfone.

m-phinidine diamine, dicyandiamide, n-aminoethylpiperazine, isophorone diamine.

Among these, diaminodiphenylsulfone is particularly desirable.

As curing accelerators, tertiary amines, quaternary ammonium salts,
Imidazoles, Br3-amine complex compounds, etc. can be used arbitrarily.

The amount of curing agent and curing accelerator to be used varies depending on the amount of glycidyl compound and the conditions of use, but it is usually best to use the curing agent in the range of 0.5 to 1.5 equivalents based on the glycidyl group, and the curing accelerator is 0.1-5.0% by weight based on glycidylated product
Good to use.

The resin composition according to the present invention can be prepared using various known mixing methods, and the method is not particularly limited, and if necessary, a solvent can be added to lower the viscosity. .

When the resin composition according to the present invention is applied as a matrix resin for carbon fibers, it provides a cured product with high heat resistance and excellent composite properties. Especially at high temperatures, for example 150
It is characterized by a higher interlaminar shear strength (ILSS) retention rate at C than that of conventionally used epoxy resins, and can be used in fields that require a high degree of heat resistance, such as aircraft.

(Examples) The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited only to these Examples. In the following description, parts represent parts by weight, and ILSS represents interlaminar shear strength.

Example 1 Using poly-p-vinylphenol with a molecular weight of aooo to 12,000 as a starting material, glycidyl etherification was performed using epichlorohydrin to obtain a glycidylated product of poly-p-vinylphenol (hereinafter abbreviated as glycidylated product A). Ta. The epoxy equivalent of this product was 208, and the softening point was 110-120°C.

50 parts of the above glycidylated compound A, Epicote 828 (bisphenol A type epoxy resin, manufactured by Shell Chemical Co., Ltd.) 50
19.3 parts of 4.4'-diaminodiphenylsulfone and 1.0 part of 13B''a-monoethylamine complex compound were dissolved in 120 parts of acetone to form a homogeneous solution.

Next, carbon fibers (Besphite HTA6000, manufactured by Toho Bethlon Co., Ltd.) aligned in one direction were impregnated with the resin solution described below, air-dried at room temperature for 1 hour, and then heated to 180°C.
was dried for 5 minutes to create a prepreg. The obtained prepregs were laminated and press-molded at 150°C for 30 minutes, then at 170°C for 60 minutes, and at 200°C for 120 minutes.
After-curing was performed for 30 minutes to obtain a molded product. The carbon fiber content of this molded product was 49%.

The properties of the obtained molded product were as follows.

Bending strength 120 to 9/rtd (23°C) 10
4kti/rxd (150'C) Flexural modulus 690
0&9/d (23°C) ILS S B, 7 to 9/1trA (28°C) 6,'1kg/d (150
'C) Comparative Example 1 Epicote DX-210-B-80 (manufactured by Shell Chemical Co., Ltd.)
10 (15 parts of 1,4,4'-diaminodiphenylmethane and 1.1 parts of BF3-monoethylamine complex compound were dissolved in a mixed solvent of 75 parts of acetone and 25 parts of methyl ethyl ketone to make a homogeneous solution. Using this resin solution, A prepreg was obtained in the same manner as in Example 1, and a molded article was created.

The resulting molded product had a carbon fiber content of 60% and had the following properties.

Bending strength 125kQ/rdc 28°C) 61 parts g/d (t 50°C) Flexural modulus 8620kq/1tt4 ILS8 7.1 parts g/d (23°C) 8.5 k
Q/1trA (150℃) Comparative example 2
,.

100 parts of tetraglycidyldiaminodiphenylmethane (Ebototo YH484, manufactured by Tobu Kasei Co., Ltd.), 4,4'-diaminodiphenylsulfone go part, and 2.3 parts of BFg-monoethylamine complex compound were dissolved in 100 parts of acetone to form a homogeneous solution. Using this resin solution, a prepreg was obtained in the same manner as in Example 1 to create a molded article.

The resulting molded product had a carbon fiber content of 54% and had the following properties.

Claims (3)

[Claims] (1) An epoxy resin composition for reinforcing carbon fibers containing a glycidylated polyalkenylphenol. (2) The epoxy resin composition for reinforcing carbon fibers according to claim 1, comprising (a) a glycidylated polyalkenylphenol, (b) an epoxy resin curing agent, and (c) a curing accelerator. (3) The epoxy resin composition for reinforcing carbon fibers according to claim 1 or 2, wherein the glycidylated polyalkenylphenol is poly-p-glycidyl-oxystyrene.