Abstract: A porous carbon sheet including at least carbon fibers, having a thickness of 30 to 95 ?m, a gas permeation resistance of 0.5 to 8.8 Pa, and a tensile strength of 5 to 50 N/cm, and a gas diffusion electrode substrate including a porous carbon sheet containing at least carbon fibers, at least one surface thereof having a microporous layer containing at least an electric conductive filler, the gas diffusion electrode substrate being dividable in the thickness direction into a smaller pore part and a larger pore part, the larger pore part having a thickness of 3 to 60 ?m.

Abstract: A porous carbon sheet includes a carbon fiber and a binding material, wherein when in a measured surface depth distribution, a ratio of an area of a portion having a depth of 20 ?m or less in a measured area of one surface is a surface layer area ratio X, and a ratio of an area of a portion having a depth of 20 ?m or less in a measured area of another surface is a surface layer area ratio Y, the surface layer area ratio X is larger than the surface layer area ratio Y, and a difference between the surface layer area ratios is 3% or more and 12% or less.

Abstract: The present invention provides a method for efficiently producing a gas diffusion electrode substrate having excellent adhesion property. This method is a method for producing a gas diffusion electrode substrate having a porous layer on at least one surface of an electroconductive porous substrate which includes the steps of a coating step wherein a coating solution containing electroconductive particles, a water-repellant material, a dispersion medium, and a surfactant is coated on the electroconductive porous substrate, a drying step wherein heating is conducted at a temperature lower than the temperature of a first heat treatment step, the first heat treatment step wherein the heating is conducted at a temperature lower than the melting point of the water-repellant material, and a second heat treatment step wherein the heating is conducted at a temperature higher than the melting point of the water-repellant material, wherein the coating solution contains at least 0.09 part by weight and up to 0.

Abstract: The purpose of the present invention is to provide a carbon sheet that is suitably employed in a gas-diffusion-electrode substrate that has excellent flooding resistance and with which it is possible to suppress internal peeling of the carbon sheet. In order to achieve the aforementioned purpose, the present invention has the following configuration.

Abstract: A porous carbon sheet contains carbon fiber and a binder, wherein the carbon sheet is characterized in that in a section from a plane having a 50% filling ratio closest to one surface to a plane having a 50% filling ratio closest to the other surface, when letting layer X be a layer with the largest filling ratio close to the one surface, layer Y be a layer with a filling ratio smaller than layer X close to the other surface, and layer Z be the layer positioned between layer X and layer Y for layers obtained by dividing the carbon sheet equally into three in a direction perpendicular to the surfaces, the filling ratio for the layers becomes smaller in order of layer X, layer Y, and layer Z.

Abstract: A porous carbon sheet including at least carbon fibers, having a thickness of 30 to 95 ?m, a gas permeation resistance of 0.5 to 8.8 Pa, and a tensile strength of 5 to 50 N/cm, and a gas diffusion electrode substrate including a porous carbon sheet containing at least carbon fibers, at least one surface thereof having a microporous layer containing at least an electric conductive filler, the gas diffusion electrode substrate being dividable in the thickness direction into a smaller pore part and a larger pore part, the larger pore part having a thickness of 3 to 60 ?m.

Abstract: The purpose of the present invention is to provide a carbon sheet that is suitably employed in a gas-diffusion-electrode substrate that has excellent flooding resistance and with which it is possible to suppress internal peeling of the carbon sheet. In order to achieve the aforementioned purpose, the present invention has the following configuration.

Abstract: A porous carbon sheet contains a carbon fiber and a binding material, wherein layers are obtained in a section spanning from a plane closest to one of the surfaces and having 50% of the mean fluorine intensity to a plane closest to the other surface and having 50% of the mean fluorine intensity by dividing this section evenly into three in an orthogonal direction to the carbon sheet plane; among the layer close to one of the surfaces and the layer close to the other surface, the layer having the larger layer mean fluorine intensity is designated layer X, the layer having the smaller one is designated layer Y, and the layer between the layer X and the layer Y is designated layer Z; and the layer mean fluorine intensities decrease in the order: layer X, layer Y, and layer Z.

Abstract: A porous carbon sheet contains carbon fiber and a binder, wherein the carbon sheet is characterized in that in a section from a plane having a 50% filling ratio closest to one surface to a plane having a 50% filling ratio closest to the other surface, when letting layer X be a layer with the largest filling ratio close to the one surface, layer Y be a layer with a filling ratio smaller than layer X close to the other surface, and layer Z be the layer positioned between layer X and layer Y for layers obtained by dividing the carbon sheet equally into three in a direction perpendicular to the surfaces, the filling ratio for the layers becomes smaller in order of layer X, layer Y, and layer Z.

Abstract: A porous carbon sheet includes a carbon fiber and a binding material, wherein when in a measured surface depth distribution, a ratio of an area of a portion having a depth of 20 ?m or less in a measured area of one surface is a surface layer area ratio X, and a ratio of an area of a portion having a depth of 20 ?m or less in a measured area of another surface is a surface layer area ratio Y, the surface layer area ratio X is larger than the surface layer area ratio Y, and a difference between the surface layer area ratios is 3% or more and 12% or less.

Abstract: A method of manufacturing a total heat exchange element includes bonding a liner sheet and a corrugated sheet together to prepare a piece of single-faced corrugated cardboard and stacking plural pieces of the single-faced corrugated cardboard obtained in the previous step so that corrugated stripe directions of respective two adjacent pieces of single-faced corrugated cardboard are allowed to cross with each other, wherein a moisture absorbent is contained in at least a part of each of the liner sheet and the corrugated sheet, and R1 is 1 to 20 g/m2 and R1/R2 is 0.5 to 2.0 when, before pieces of single-faced corrugated cardboard are stacked, the content of the moisture absorbent in the liner sheet and the content of the moisture absorbent in the corrugated sheet are defined as R1 and R2, respectively.

Abstract: A heat exchange element has a liner sheet high in water vapor transmission properties and gas shielding properties, specifically, and is prepared by combining a piece of single-faced corrugated cardboard 1 constituted of a liner sheet 1 with a carbon dioxide shielding rate of greater than or equal to 95% and a corrugated sheet 1 and a piece of single-faced corrugated cardboard 2 constituted of a liner sheet 2 with a water vapor permeability of greater than or equal to 80 g/m2·hr and a corrugated sheet 2, and a heat exchanger.

Abstract: A base paper for heat exchangers having a stacked structure including at least one layer of a first layer composed mainly of a fibrous substance with a Canadian standard freeness specified in JIS P8121 (1995) of less than 150 ml and at least one layer of a second layer composed mainly of a fibrous substance with a Canadian standard freeness specified in JIS P8121 (1995) of greater than or equal to 150 ml, and a total heat exchange element prepared by stacking pieces of corrugated cardboard in which the base paper for heat exchange is used as a part thereof.