| (19) |
 |
|
(11) |
EP 0 376 625 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
08.05.1991 Bulletin 1991/19 |
| (43) |
Date of publication A2: |
|
04.07.1990 Bulletin 1990/27 |
| (22) |
Date of filing: 21.12.1989 |
|
|
| (84) |
Designated Contracting States: |
|
BE DE FR GB IT |
| (30) |
Priority: |
28.12.1988 JP 328891/88
09.02.1989 JP 28773/89
16.02.1989 JP 35040/89
|
| (71) |
Applicant: Asahi Kasei Kogyo Kabushiki Kaisha |
|
Osaka-shi
Osaka 530 (JP) |
|
| (72) |
Inventors: |
|
- Kanzaki, Hidetoshi
Fuji-Shi
Shizuoka (JP)
- Kanamori, Naoki
Fuji-Shi
Shizuoka (JP)
|
| (74) |
Representative: Lewin, John Harvey et al |
|
ELKINGTON AND FIFE
Prospect House,
8 Pembroke Road
Sevenoaks,
Kent, TN13 1XR
Sevenoaks,
Kent, TN13 1XR (GB) |
|
| |
|
| (54) |
Acrylic synthetic fiber and process for preparation thereof |
(57) An acrylic synthetic fiber having in the transverse section thereof many openings
having an indeterminate shape and a size of 0.1 to 1.6 µm, wherein in the interior
of the fiber, each opening forms a vein-like or straw-like void extending substantially
in parallel to the longitudinal axis of the fiber and having a length of at least
60 µm. This acrylic fiber is prepared by a) dissolving in a suitable solvent an acrylic
polymer comprising at least 60 weight% of an acrylonitrile unit and 5 to 20 weight
%, based on the weight of the acrylic polymer, of a polyalkylene glycol having a number
average molecular weight of 5,000 to 50,000, b) aging the formed spinning solution
for at least 4 hours, and c) extruding the spinning solution into a coagulating medium.
The acrylic fiber is useful, e.g., as a frictional material comprising (a) a pulpy
material made from the acrylic fiber, (b) a resin and (c) a filler.