Treatment of flexible graphite material and method thereof
A process for producing a flexible graphite sheet having two major surfaces includes compressing particles of exfoliated graphite to form a sheet; impregnating a resin composition into the sheet so as to form a resin-impregnated sheet; curing the resin-impregnated sheet; and thereafter treating the cured, resin-impregnated sheet to provide a structure thereon or therein.
1 . A process for producing a flexible graphite sheet having two major surfaces, comprising
(a) compressing particles of exfoliated graphite to form a sheet;
(b) impregnating a resin composition into the sheet so as to form a resin-impregnated sheet;
(c) curing the resin-impregnated sheet; and
(d) thereafter treating the cured, resin-impregnated sheet to provide a structure thereon or therein.
2 . The process of claim 1 , wherein the resin-impregnated sheet is at least about 45% cured prior to treatment to provide a structure thereon or therein.
3 . The process of claim 2 , wherein the resin-impregnated sheet is at least about 65% cured prior to treatment to provide a structure thereon or therein.
4 . The process of claim 2 , wherein treatment to provide a structure thereon or therein comprises perforating the sheet to provide channels extending through opposed major surfaces of the sheet.
5 . The process of claim 2 , wherein treatment to provide a structure thereon or therein comprises embossing channels on one or both of the opposed major surfaces of the sheet.
6 . The process of claim 1 , wherein the resin composition is selected from acrylic-, epoxy- and phenolic-based resin systems, fluoro-based polymers, or mixtures thereof.
7 . The process of claim 6 , wherein the resin composition is selected from resin systems based on diglycidyl ether of bisphenol A, resole phenolics and novolac phenolics.
8 . The process of claim 1 , wherein the treated sheet is used in the formation of a component for an electrochemical fuel cell.
9 . The process of claim 8 , wherein the treated sheet is used in the formation of a fuel cell flow field plate.
10 . The process of claim 8 , wherein the treated sheet is used in the formation of a fuel cell gas diffusion layer.
11 . A process for producing a substrate material useful for the formation of a fuel cell component, comprising
(a) compressing particles of exfoliated graphite to form a sheet;
(b) impregnating a resin composition into the sheet so as to form a resin-impregnated sheet;
(c) curing the resin-impregnated sheet; and
(d) thereafter treating the cured, resin-impregnated sheet to provide a structure thereon or therein.
12 . The process of claim 11 , wherein the resin-impregnated sheet is at least about 45% cured prior to treatment to provide a structure thereon or therein.
13 . The process of claim 12 , wherein the resin-impregnated sheet is at least about 65% cured prior to treatment to provide a structure thereon or therein.
14 . The process of claim 12 , wherein treatment to provide a structure thereon or therein comprises perforating the sheet to provide channels extending through opposed major surfaces of the sheet.
15 . The process of claim 12 , wherein treatment to provide a structure thereon or therein comprises embossing channels on one or both of the opposed major surfaces of the sheet.
16 . The process of claim 11 , wherein the resin composition is selected from acrylic-, epoxy- and phenolic-based resin systems, fluoro-based polymers, or mixtures thereof.
17 . The process of claim 16 , wherein the resin composition is selected from resin systems based on diglycidyl ether of bisphenol A, resole phenolics and novolac phenolics.
18 . The process of claim 11 , wherein the treated sheet is used in the formation of a fuel cell flow field plate.
19 . The process of claim 11 , wherein the treated sheet is used in the formation of a fuel cell gas diffusion layer.