Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From phenol – phenol ether – or inorganic phenolate
Patent
1990-06-22
1991-10-01
Nielsen, Earl
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From phenol, phenol ether, or inorganic phenolate
528 99, 528102, 528103, 528109, C08G 5938, C08G 5950
Patent
active
050534750
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to an epoxy resin composition for prepreg having excellent hot wet property and improved compression strength after impact. Composite materials obtained from said resin composition can be used in air planes, automobiles and general industrial applications.
BACKGROUND ART
As the matrix resin for composite material, there have hitherto been widely used epoxy resins for their adhesivity and high rigidity. As the high performance structural matrix resin, in particular, there has been widely used, since 1972, a composition comprising, as main components, N,N,N',N'-tetraglycidyldiaminodiphenylmethane and 4,4'-diaminodiphenyl sulfone.
PROBLEMS TO BE SOLVED BY THE INVENTION
Composite materials obtained from this composition, however, are low in elongation although relatively high in high-temperature compression strength after moisture absorption; accordingly, they have had a draw back that their elongation at break is smaller than recently developed high-elongation reinforcing fibers, for example, a carbon fiber having an elongation at break of 1.5% or more, an aramid fiber and a glass fiber. Also, said composite materials are very low in compression strength after impact and have been completely insufficient for use as a primary structural material. In view of the above, the present inventors made investigation on an epoxy resin composition for prepreg giving a composite material having excellent hot wet property, high utilization as a reinforcing material and improved compression strength after impact and, as a result, have reached the present invention.
MEANS FOR SOLVING THE PROBLEMS
The gist of the present invention is an epoxy resin composition comprising, as essential components,
(A) a bifunctional epoxy resin,
(B) a trifunctional epoxy resin,
(C) a phenol compound represented by the following formula ##STR2## (X.sub.1 to X.sub.8 each represent Br, Cl or H and at least four of X.sub.1 to X.sub.8 each represent Br or Cl; R.sub.1 and R.sub.2 each represent H or CH.sub.3), and
(D) 4,4'-diaminodiphenyl sulfone or 3,3'-diamino
diphenyl sulfone.
In these compositions, it is preferable that part or all of (A), all of (B) and all of (C) are subjected to a preliminary reaction to allow 80% or more of the phenolic OH of (C) to undergo a preliminary reaction with the epoxy groups of (A) and (B).
The present invention relates further to an epoxy resin composition comprising the above-mentioned epoxy resin composition and a reinforcing fiber.
As the bifunctional epoxy resin (A) used in the present invention, there can be mentioned glycidyl ether compound derived from bisphenol A, glycidyl ether compound derived from bisphenol F, a brominated epoxy resin obtained by borminating either of them, glycidyl ether compound derived from bisphenol S, etc.
In order to obtain improved toughness, it is preferable to use, in particular, glycidyl ether compound derived from bisphenol A or glycidyl ether compound derived from bisphenol F as a main component. The molar ratio of the component (A) and other epoxy resin (B) is (A)/(B)=1/0.1 to 1/1.2, preferably 1/0.2 to 1/1.0. When the molar ratio is larger than this range, the resulting epoxy resin composition has reduced heat resistance and reduced chemical resistance; therefore, such a molar ratio is not desirable. When the molar ratio is smaller than the above range, the resulting epoxy resin composition has insufficient toughness and elongation; therefore, such a molar ratio is undesirable.
As the trifunctional epoxy resin (B) used in the present invention, there may be mentioned glycidylamine type epoxy resins, for example, N,N,O-triglycidyl-p or m-aminophenol, N,N,O-triglycidyl-4-amino-m or -5-amino-o-cresol, 1,1,1-(triglycidyloxyphenyl)methane, etc.
Among them, there preferably used N,N,O-triglycidyl-p or m-aminophenol and N,N,O-triglycidyl-4-amino-m- or -5-amino-o-cresol.
As the phenol compound (C) used in the present invention, there can be mentioned tetrabromobisphenol A, tetrabromobisphenol F, octabromobisphenol A, hexabro
REFERENCES:
patent: 4550129 (1985-10-01), Nir et al.
patent: 4588778 (1986-05-01), Nir et al.
patent: 4603157 (1986-07-01), Asai et al.
patent: 4605710 (1986-08-01), Guilbert
patent: 4663400 (1987-05-01), Wang et al.
patent: 4959438 (1990-09-01), Tada et al.
Agata Akira
Kubo Takatoshi
Murata Takashi
Saruta Masahiro
Tada Hisashi
Mitsubishi Rayon Co. Ltd.
Nielsen Earl
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