Manufacturing method of a highly conductive polytetrafluoroethylene sheet
US6270707A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 2, 1998 |
| Grant date | Aug 7, 2001 |
| Priority date | — |
| Expiry date | Sep 2, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2327/18
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
This invention concerns a method of manufacturing a highly conductive polytetrafluoroethylene sheet; a method of manufacturing a highly conductive unsintered polytetrafluoroethylene sheet: and a method of manufacturing a highly conductive sintered sheet. In the first method, a paste of polytetrafluoroethylene powder admixed with conductive substance and extrusion lubricant is extruded to preform an unsintered tube-like material, and at least one place on the circumference of this extruded material, the material is cut open longitudinally and the resulting sheet is calendered if necessary. The second method includes a sintering process for the sheet. This invention also concerns a highly conductive polytetrafluoroethylene sheet having a wide-width and long-length, which is obtained by the above-mentioned method. This sheet is not less than 170 mm in width and has variance of volume resistivity (conductivity) in the longitudinal direction, 10% or less, preferably 7% or less in the cross direction. This invention can provide a highly conductive wide-type PTFE sheet whose conductivity in the longitudinal direction is nearly uniform in the cross direction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.