Claims
- 1. A process of producing a cloth prepreg comprising impregnating a resin composition into a woven fabric in two steps, said resin composition comprising an epoxy resin, a curing agent and a solid acrylonitrile-butadiene rubber having a functional group and having a weakly cross-linked structure, wherein in the first impregnation step, the resin is impregnated so as to attain a resin content W.sub.R of 10-30%.
- 2. The process of claim 1, wherein the pressure applied in said first impregnation step is higher than that in the second impregnation step, and the maximum impregnation linear pressure in said first impregnation step is not less than 1000 kg/cm.sup.2.
- 3. The process of claim 1, wherein the resin composition impregnated in the first impregnation step has a complex coefficient of viscosity .eta..sub.0.02 determined at 80.degree. C. under a vibration frequency of 0.02 Hz of not less than 5000 poise and less than 40,000 poise, and the resin composition impregnated in said second impregnation step has a complex coefficient of viscosity .eta..sub.0.02 determined at 80.degree. C. under a vibration frequency of 0.02 Hz of 40,000-400,000 poise.
- 4. The process of claim 1, wherein the pressure applied in said first impregnation step is higher than that applied in the second impregnation step.
- 5. A process of producing a cloth prepreg comprising impregnating a resin composition into a woven fabric having made of multifilament yarns of carbon fibers, the widths W (mm) and finenesses D (d:denier) of said warps and woofs satisfying the equation:
- W=k.multidot.(D/.rho.).sup.5/9
- wherein k represents 3.5.times.10.sup.-2 -10.0.times.10.sup.-2 mm.multidot.d.sup.-5/9 and .rho. represents the specific gravity of said carbon fibers, said woven fabric having a cover factor K.sub.c of 90.0-99.8%, and wherein said resin composition comprises an epoxy resin, a curing agent and an uncrosslinked, solid acrylonitrile-butadiene rubber having a functional group.
- 6. The process of claim 5, wherein said resin composition has a complex coefficient of viscosity .eta..sub.0.5 determined at 80.degree. C. under a vibration frequency of 0.5 Hz during heating from 50.degree. C. at a rate of 1.5.degree. C./min of 100-1500 poise, and has a minimum complex coefficient of viscosity n.sub.min determined at 80.degree. C. under a vibration frequency of 0.5 Hz during heating from 50.degree. C. at a rate of 1.5.degree. C./min of 50-300 poise.
Priority Claims (1)
Number |
Date |
Country |
Kind |
4-80522 |
Mar 1992 |
JPX |
|
CROSS REFERENCE TO THE RELATED APPLICATION
This application is a division of U.S. application Ser. No. 08/368,674, filed Jan. 4, 1995, pending which is a division of Ser. No. 08/088,635 filed Jul. 9, 1993, now U.S. Pat. No. 5,447,785 which is a continuation-in-part of 08/024,957, filed Mar. 2, 1993, now abandoned.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
4237175 |
Kobayashi |
Dec 1980 |
|
5217796 |
Kasai et al. |
Jun 1993 |
|
Foreign Referenced Citations (4)
Number |
Date |
Country |
0262891 |
Apr 1988 |
EPX |
0351028 |
Jan 1990 |
EPX |
0434013 |
Jun 1991 |
EPX |
2825191 |
Jan 1979 |
DEX |
Non-Patent Literature Citations (3)
Entry |
Database WPIL, Derwent Publications Ltd., London, GB: AN 90-258317[34] & JP-A-2 182 409 Matsushita Elec. Works 17 Jul. 1990 (Abstract). |
Catalog from Nitto Boseki Co., Ltd. (1989). |
JIS R 3413 (1963). |
Divisions (2)
|
Number |
Date |
Country |
Parent |
368674 |
Jan 1995 |
|
Parent |
88635 |
Jul 1993 |
|
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
24957 |
Mar 1993 |
|