Claims
- 1. A process for preparing a fiber comprising extruding a raw material composed mainly of a polypropylene having a syndiotactic pentad fraction of 0.7 or more, wherein said raw material is extruded into a fibrous form.
- 2. The process according to claim 1 wherein the extruded material is stretched.
- 3. The process for preparing a fiber according to claim 1 wherein said raw material is a polypropylene having a syndiotactic pentad fraction of 0.7 or more.
- 4. The process for preparing a fiber according to claim 1 wherein said raw material is a composition comprising at least 50 parts by weight of a polypropylene having a syndiotactic pentad fraction of 0.7 or more and at most 50 parts by weight of an isotactic polypropylene.
- 5. The process for preparing a fiber according to claim 1 wherein said raw material is a composition comprising a polypropylene (A) having a syndiotactic pentad fraction of 0.7 or more and a polypropylene (B) having a different molecular weight and a syndiotactic pentad fraction of 0.7 or more, the value of common logarithms of the ratio of the intrinsic viscosity .eta..sub.2 of the polypropylene (B) to the intrinsic viscosity .eta..sub.1 of the polypropylene (A) [log(.eta..sub.2 /.eta..sub.1)], both measured in a tetralin solution at 135.degree. C., being either more than 0.05 or less than -0.05, the weight ratio of the polypropylene (A) to the polypropylene (B) being in the range of 95:5-5:95.
- 6. The process for preparing a fiber according to claim 1 wherein said raw material is a composition comprising a polypropylene (A) having a syndiotactic pentad fraction of 0.7 or more and an isotactic polypropylene (B) having a different molecular weight, the value of common logarithms of the ratio of the intrinsic viscosity .eta..sub.2 of the polypropylene (B) to the intrinsic viscosity .eta..sub.1 of the polypropylene (A) [log(.eta..sub.2 /.eta..sub.1)], both measured in a tetralin solution at 135.degree. C., being either more than 0.05 or less than -0.05, the weight proportion of the polypropylene (A) and the polypropylene (B) being at least 50 parts for the polypropylene (A) and at most 50 parts for the polypropylene (B).
Priority Claims (2)
Number |
Date |
Country |
Kind |
1-217403 |
Aug 1989 |
JPX |
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1-217404 |
Aug 1989 |
JPX |
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Parent Case Info
This application is a divisional of application Ser. No. 08/015,056, filed Feb. 8, 1993 now U.S. Pat. No. 5,478,646, which is a continuation of application Ser. No. 07/562,841, filed Aug. 6, 1990, now abandoned.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
5200131 |
Asanuma et al. |
Apr 1993 |
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Divisions (1)
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Number |
Date |
Country |
Parent |
15056 |
Feb 1993 |
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Continuations (1)
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Number |
Date |
Country |
Parent |
562841 |
Aug 1990 |
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