EP0418155A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Porous material of polytetrafluoroethylene and process for producing the same
Assignee: Sumitomo Electric Industries Ltd
•
Filing: 1990-09-12
•
Granted: —
•
Expires: 2010-09-12
Abstract
Abstract A porous material of polytetrafluoroethylene consisting essentially of fibers of polytetrafluoroethylene. The porous material of PTFE is produced by heat-treating a molded article prepared by paste extruding of PTFE fine powder under such a condition that the heat-treated molded article shows at least one endothermic peak which appears between an endothermic peak position of the fine powder and an endothermic peak position of a sintered product thereof on a differential scanning calorimeter chart and then is stretched along at least one direction.
Inventors
- 👤 Akira C/O Kumatori Works Of Harada
- 👤 Hiroshi C/O Osaka Works Of Mano
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 19:21
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/18; B; B01; B01D; B01D71/00; B01D71/06; B01D71/30; B01D71/32; B01D71/36; B29; B29C; B29C55/00; B29C55/005; B29K; B29K2027/00; B29K2027/12; B29K2027/18; C08J2327/00; C08J2327/02; C08J2327/12; C08J2327/18
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
21 words
A porous material of polytetrafluoroethylene characterized in that said porous material has a network structure consisting essentially of fibers of polytetrafluoroethylene.
Claim 2
Dependent Claim
21 words
A porous material of polytetrafluoroethylene characterized in that said porous material has a network structure consisting essentially of fibers of polytetrafluoroethylene.
Claim 3
Dependent Claim
42 words
The porous material of polytetrafluoroethylene set forth in Claim 1 wherein said porous material has the IPA bubble point of higher than 1.0 kg/cm², the IPA solvent shrinkage ratio of lower than 15 % and Gurley number of less than 100 sec.
Claim 4
Dependent Claim
42 words
The porous material of polytetrafluoroethylene set forth in Claim 2 wherein said porous material has the IPA bubble point of higher than 3.0 kg/cm², the IPA solvent shrinkage ratio of lower than 30 % and Gurley number of less than 100 sec.
Claim 5
Dependent Claim
90 words
The porous material of polytetrafluoroethylene set forth in any one of Claim 1 to 3 wherein said porous material is obtained by heat-treating a non-sintered molded article prepared by paste extrusion of polytetrafluoroethylene fine powder under such a condition that the heat-treated molded article shows at least one endothermic peak which appears between an endothermic peak position of the fine powder and an endothermic peak position of a sintered product thereof on a differential scanning calorimeter chart and then by stretching the heat-treated molded article along at least one direction.
Claim 6
Dependent Claim
24 words
The porous material of polytetrafluoroethylene set forth in any one of Claim 1 to 4 wherein said porous material has a shape of sheet.
Claim 7
Dependent Claim
81 words
The process for producing a porous material of polytetrafluoroethylene characterized in that a non-sintered molded article prepared by extruding a paste of polytetrafluoroethylene fine powder is subjected to a heat-treatment under such a condition that the heat-treated molded article shows at least one endothermic peak which appears between an endothermic peak position of the fine powder and an endothermic peak position of a sintered product thereof on a differential scanning calorimeter chart and then is stretched along at least one direction.
Claim 8
Dependent Claim
81 words
The process for producing a porous material of polytetrafluoroethylene characterized in that a non-sintered molded article prepared by extruding a paste of polytetrafluoroethylene fine powder is subjected to a heat-treatment under such a condition that the heat-treated molded article shows at least one endothermic peak which appears between an endothermic peak position of the fine powder and an endothermic peak position of a sintered product thereof on a differential scanning calorimeter chart and then is stretched along at least one direction.
Claim 9
Dependent Claim
29 words
The process set forth in Claim 6 wherein said non-sintered molded article is stretched along at least two directions at an area1 stretch ratio of more than 5 times.
Claim 10
Dependent Claim
22 words
The process set forth in Claim 6 or 7 wherein the stretching is effected at a temperature between 0 and 300 °C.
Claim 11
Dependent Claim
22 words
The process set forth in any one of Claim 6 to 8 wherein the heat-treated molded article is further heated after stretching.
Claim 12
Dependent Claim
21 words
The process set forth in Claim 9 wherein said the heat-treated molded article is heated at a temperature above 200 °C.
Claim 13
Dependent Claim
21 words
The process set forth in Claim 10 wherein said the heat-treated molded article is heated at a temperature above 347 °C.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.