Method for producing laminated porous sheet comprising polytetrafluoroethylene and carbon particles

摘要

The method for producing the porous sheet of the present invention includes the steps of (I) preparing a plurality of sheet materials that contain polytetrafluoroethylene and carbon particles and (II) stacking the plurality of sheet materials over one another and rolling the stacked sheet materials. In the method for producing the porous sheet of the present invention, step (I) and step (II) may be repeated alternately. Further, as the sheet materials to be used in the production method of the present invention, a base sheet obtained by forming a mixture containing polytetrafluoroethylene and carbon particles into sheet form also can be used, or a laminated sheet obtained by stacking a plurality of base sheets over one another and rolling them also can be used, for example.

主权项

1. A method for producing a porous sheet comprising steps of:
(I) preparing a plurality of sheet materials, wherein each of the sheet materials comprises polytetrafluoroethylene, carbon particles, and a forming aid; and (II) stacking the plurality of the sheet materials over one another and rolling the stacked sheet materials, wherein the each of the sheet materials is a base sheet or a laminated sheet of the base sheets, the forming aid consists of one or more saturated hydrocarbons, an amount of the carbon particles in the sheet materials is from 60 to 90 wt % relative to a total amount of the polytetrafluoroethylene and the carbon particles, the step (I) and the step (II) are repeated alternately, and the porous sheet has a porosity from 70 to 80 vol %, and wherein the base sheet is prepared by a method comprising steps of: mixing the polytetrafluoroethylene, the carbon particles, and the forming aid under a condition in which forming a fibrous polytetrafluoroethylene is suppressed so as to form a mixture; and then forming the base sheet of the mixture in a sheet form.