Expanded porous polytetrafluoroethylene film-laminated sheet, and gasket composed of said sheet

摘要

The laminated sheet of this invention is a sheet including expanded porous polytetrafluoroethylene films laminated by thermal compression bonding, wherein the sheet has a specific surface area of 9.0 m2/g or larger and a density of from 0.4 g/cm3 to lower than 0.75 g/cm3, thereby making it possible to improve both the creep resistance and the adhesiveness between the films of the expanded porous PTFE film-laminated sheet.

主权项

1. A laminated sheet comprising laminated expanded porous polytetrafluoroethylene films, wherein the sheet has a specific surface area of 9.0 m2/g or higher and a density of from 0.4 g/cm3 to lower than 0.75 g/cm3, wherein the laminated sheet has a 180-degree peeling strength of 0.20 N/mm or higher between the films at the center in the thickness direction of the sheet and wherein the laminated sheet has a stress-relaxation rate of 45% or lower after 1 hour when compressed at a surface pressure of 50 MPa, and wherein the laminated sheet has a thickness of from about 0.1 mm to about 300 mm.