Claims
- 1. Colloidal polytetrafluoroethylene fine particles having an average particle size of 0.05 to 1.0 .mu.m and each comprising a core mode of polytetrafluoroethylene which has a high molecular weight, a standard specific gravity (SSG) of 2.210 or less and can be fibrilled and a shell surrounding said core made of a low molecular weight homopolymer of tetrafluoroethylene having a molecular weight of 10,000 to 800,000, which can not be fibrilled.
- 2. The colloidal polytetrafluoroethylene fine particles according to claim 1, wherein a weight ratio of said core to said shell is from 95:5 to 30:70.
- 3. A polytetrafluoroethylene powder obtained by coagulating and drying an aqueous dispersion containing a colloidal polytetrafluoroethylene fine particles as claimed in claim 1.
- 4. A sintered polytetrafluoroethylene powder obtained by sintering and pulverizing a polytetrafluoroethylene powder as claimed in claim 3.
- 5. The colloidal polytetrafluoroethylene fine particles according to claim 1, wherein a weight ratio of said core to said shell is from 90:10 to 50:50.
- 6. The colloidal polytetrafluoroethylene fine particles according to claim 1, wherein the average particle size is 0.1 to 0.5 .mu.m.
- 7. The colloidal polytetrafluoroethylene fine particles according to claim 1, wherein the shell has a melt viscosity of about 10.sup.2 to 10.sup.6 poises.
- 8. The colloidal polytetrafluoroethylene fine particles according to claim 1, wherein the core has a number average molecular weight of 1,500,000 to 9,000,000.
- 9. The colloidal polytetrafluoroethylene fine particles according to claim 1, wherein the core has a standard specific gravity (SSG) of 2.210 to 2.149.
- 10. The colloidal polytetrafluoroethylene fine particles according to claim 1, wherein the core has a standard specific (SSG) of 2.20 to 2.149.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2-282413 |
Oct 1990 |
JPX |
|
Parent Case Info
This application is a continuation of application Ser. No. 07/779,318 filed on Oct. 18, 1991, now abandoned.
US Referenced Citations (6)
Foreign Referenced Citations (4)
Number |
Date |
Country |
0030664 |
Jun 1981 |
EPX |
0127407 |
Dec 1984 |
EPX |
0221554 |
May 1987 |
EPX |
0322877 |
Jul 1989 |
EPX |
Continuations (1)
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Number |
Date |
Country |
Parent |
779318 |
Oct 1991 |
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