US4894355A — Flexible, water-repellent baked carbon plate, its…

Claim 1

Independent Claim 93 words

A process for producing a flexible, water-repellent baked carbon plate, comprising the steps of: infiltrating a suspension of polytetrafluoroethylene into a carbon paper comprising carbon fiber and a carbonized binder made from an organic binder so as to form an impregnated carbon paper, baking the impregnated carbon paper, and rolling or pressing the carbon fiber to effect cutting of said carbon fiber so as to provide cutting edges, wherein said step of rolling or pressing is effected after the step of baking, and infiltration of part of said polytetrafluorethylene into the cutting edges.

Claim 2

Dependent Claim 93 words

A process for producing a flexible, water-repellent baked carbon plate, comprising the steps of: infiltrating a suspension of polytetrafluoroethylene into a carbon paper comprising carbon fiber and a carbonized binder made from an organic binder so as to form an impregnated carbon paper, baking the impregnated carbon paper, and rolling or pressing the carbon fiber to effect cutting of said carbon fiber so as to provide cutting edges, wherein said step of rolling or pressing is effected after the step of baking, and infiltration of part of said polytetrafluorethylene into the cutting edges.

Claim 3

Dependent Claim 39 words

A process for producing a flexible, water-repellent baked carbon plate according to claim 1, wherein the heating temperature in said step of baking is within the range of from the melting temperature of the polytetrafluoroethylene to its decomposition temperature.

Claim 4

Dependent Claim 33 words

A process for producing a flexible, water-repellent baked carbon plate according to claim 1, wherein the heating temperature in said step of baking is within the range of from 330° to 400° C.

Claim 5

Dependent Claim 34 words

A process for producing a flexible, water-repellent baked carbon plate according to claim 1, wherein the thickness of the plate before the processing is reduced to 60 to 80% by said rolling or pressing.

Claim 6

Dependent Claim 31 words

A process for producing a flexible, water-repellent baked carbon plate according to claim 1, wherein said rolling or pressing is performed so as to provide 20-300 cutting edges per square millimeter.

Claim 7

Dependent Claim 31 words

A process for producing a flexible, water-repellent baked carbon plate according to claim 5, wherein the rolling or pressing is effected so as to provide 50-150 cutting edges per square millimeter.

Claim 8

Dependent Claim 147 words

A process of producing a flexible, water-repellent baked carbon plate, comprising the steps of: infiltrating a suspension of polytetrafluoroethylene into a carbon paper comprising carbon fiber and a carbonized binder made from an organic binder and binding the carbon fiber so as to impregnate the carbon paper with polytetrafluoroethylene; baking the carbon paper impregnated with the polytetrafluoroethylene at a temperature in a range from a melting point temperature of the polytetrafluoroethylene to a decomposition temperature thereof; and subjecting the carbon paper to thickness reduction to effect cutting of the carbon fibers into short fibers to provide a number of cutting edges and to infiltrate part of the polytetrafluoroethylene into the cutting edges to bind the carbon fiber having the cutting edges, said subjecting the carbon paper to thickness reduction being performed after said baking the carbon paper, thereby providing a baked carbon plate with flexibility and water-repellency.

Claim 9

Dependent Claim 147 words

A process of producing a flexible, water-repellent baked carbon plate, comprising the steps of: infiltrating a suspension of polytetrafluoroethylene into a carbon paper comprising carbon fiber and a carbonized binder made from an organic binder and binding the carbon fiber so as to impregnate the carbon paper with polytetrafluoroethylene; baking the carbon paper impregnated with the polytetrafluoroethylene at a temperature in a range from a melting point temperature of the polytetrafluoroethylene to a decomposition temperature thereof; and subjecting the carbon paper to thickness reduction to effect cutting of the carbon fibers into short fibers to provide a number of cutting edges and to infiltrate part of the polytetrafluoroethylene into the cutting edges to bind the carbon fiber having the cutting edges, said subjecting the carbon paper to thickness reduction being performed after said baking the carbon paper, thereby providing a baked carbon plate with flexibility and water-repellency.

Claim 10

Dependent Claim 44 words

A process of producing a flexible, water-repellent baked carbon plate according to claim 7, wherein, in the step of subjecting the carbon paper to thickness reduction, the thickness of the carbon paper is reduced to 60 to 80% of the thickness before the reduction.

Claim 11

Dependent Claim 29 words

A process of producing a flexible, water-repellent baked carbon plate according to claim 7, wherein said carbon plate impregnated with polytetrafluoroethylene is baked at a temperature of 330°-400° C.

Claim 12

Dependent Claim 27 words

A process of producing a flexible water-repellent baked carbon plate according to claim 7, wherein said thickness reduction is carried out by rolling of the carbon paper.

Claim 13

Dependent Claim 159 words

A process of producing a flexible fuel cell electrode, comprising the steps of: preparing a carbon paper comprising carbon fiber and a carbonized binder made from an organic binder; infiltrating a suspension of polytetrafluoroethylene into the carbon paper so as to provide a carbon paper impregnated with polytetrafluoroethylene; kneading a mixture of catalyst powder and a polytetrafluoroethylene dispersion to provide a paste catalyst; coating the paste catalyst on the carbon paper; baking the coated carbon paper impregnated with polytetrafluoroethylene at a temperature more than a melting point temperature of the polytetrafluoroethylene and not more than a decomposition temperature thereof; and reducing thickness of the coated carbon paper to cut the carbon fiber so as to provide a number of cutting edges thereof and to cause the polytetrafluoroethylene to infiltrate into the cutting edges to bind the carbon fiber having the cutting edges, thereby providing a flexible fuel cell electrode comprising a baked carbon plate and a catalyst layer thereon.

Claim 14

Dependent Claim 159 words

A process of producing a flexible fuel cell electrode, comprising the steps of: preparing a carbon paper comprising carbon fiber and a carbonized binder made from an organic binder; infiltrating a suspension of polytetrafluoroethylene into the carbon paper so as to provide a carbon paper impregnated with polytetrafluoroethylene; kneading a mixture of catalyst powder and a polytetrafluoroethylene dispersion to provide a paste catalyst; coating the paste catalyst on the carbon paper; baking the coated carbon paper impregnated with polytetrafluoroethylene at a temperature more than a melting point temperature of the polytetrafluoroethylene and not more than a decomposition temperature thereof; and reducing thickness of the coated carbon paper to cut the carbon fiber so as to provide a number of cutting edges thereof and to cause the polytetrafluoroethylene to infiltrate into the cutting edges to bind the carbon fiber having the cutting edges, thereby providing a flexible fuel cell electrode comprising a baked carbon plate and a catalyst layer thereon.

Claim 15

Dependent Claim 41 words

A process of producing a flexible fuel cell electrode according to claim 11, wherein said catalyst layer comprises carbon particles carrying a noble metal selected from the group consisting of the elements of Group VIII of Periodic Table and a binder.

Claim 16

Dependent Claim 25 words

A process of producing a fuel cell electrode, according to claim 12, wherein said coated carbon plate is baked at a temperature of 330°-400° C.

Claim 17

Dependent Claim 26 words

A process of producing a flexible fuel cell electrode according to claim 11, wherein said baked carbon plate has a thickness of 0.1 to 1 mm.

Claim 18

Dependent Claim 26 words

A process of producing a flexible fuel cell electrode according to claim 11, wherein said thickness reduction is carried out by rolling of the carbon paper.

Claim 19

Dependent Claim 26 words

A process of producing a flexible fuel cell electrode according to claim 11, wherein said catalyst layer has a thickness within a range of 0.05-0.5 mm.

Claim 20

Dependent Claim 220 words

A process of producing a fuel cell having an anode and a cathode forming a pair of opposed electrodes, an electrolyte placed between said pair of opposed electrodes, a fuel chamber adjacent to the anode of said pair of opposed electrodes, an oxidizing agent chamber adjacent to the cathode of said pair of opposed electrodes, and a catalyst layer formed on the electrolyte side of said pair of electrodes, wherein said pair of opposed electrodes having the catalyst layer are produced by a process comprising the steps of; preparing a carbon paper comprising carbon fiber and a carbonized binder made from an organic binder; infiltrating a suspension of polytetrafluoroethylene into the carbon paper so as to provide a water-repellent carbon paper; kneading a mixture of catalyst powder and a polytetrafluoroethylene dispersion to provide a paste catalyst; coating the paste catalyst on the water-repellent carbon paper; baking the coated carbon paper at a temperature more than a melting point temperature of the polytetrafluoroethylene and not more than a decomposition temperature thereof; and reducing the thickness of the carbon paper to cut the carbon fiber so as to provide a number of cutting edges thereof and to cause the polytetrafluoroethylene to infiltrate into the cutting edges to bind the carbon fiber having the cutting edges, thereby providing a flexible fuel cell electrode.

Claim 21

Dependent Claim 220 words

A process of producing a fuel cell having an anode and a cathode forming a pair of opposed electrodes, an electrolyte placed between said pair of opposed electrodes, a fuel chamber adjacent to the anode of said pair of opposed electrodes, an oxidizing agent chamber adjacent to the cathode of said pair of opposed electrodes, and a catalyst layer formed on the electrolyte side of said pair of electrodes, wherein said pair of opposed electrodes having the catalyst layer are produced by a process comprising the steps of; preparing a carbon paper comprising carbon fiber and a carbonized binder made from an organic binder; infiltrating a suspension of polytetrafluoroethylene into the carbon paper so as to provide a water-repellent carbon paper; kneading a mixture of catalyst powder and a polytetrafluoroethylene dispersion to provide a paste catalyst; coating the paste catalyst on the water-repellent carbon paper; baking the coated carbon paper at a temperature more than a melting point temperature of the polytetrafluoroethylene and not more than a decomposition temperature thereof; and reducing the thickness of the carbon paper to cut the carbon fiber so as to provide a number of cutting edges thereof and to cause the polytetrafluoroethylene to infiltrate into the cutting edges to bind the carbon fiber having the cutting edges, thereby providing a flexible fuel cell electrode.

Claim 22

Dependent Claim 22 words

A method of producing a fuel cell according to claim 17, wherein said fuel chamber is fed with an anolyte containing methanol.

Claim 23

Dependent Claim 63 words

A method of producing a fuel cell according to claim 17, wherein the catalyst layer is formed on the electrolyte side of each of the anode and cathode of the pair of opposed electrodes, and wherein the catalyst layer of said cathode has at least one of a larger pore diameter and a larger pore volume than the catalyst layer of said anode.

Claim 24

Dependent Claim 26 words

A method of producing a fuel cell according to claim 17, wherein an ion-exchange membrane containing the electrolyte is provided between said pair of opposed electrodes.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1993-01-15	1993-07-17	1994-01-16	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1997-01-15	1997-07-17	1998-01-16	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2001-01-15	2001-07-17	2002-01-16	$7700.00	Window Closed / Lapsed

Flexible, water-repellent baked carbon plate, its production, fuel cell electrode, fuel cell electrode plate and its production and fuel cell

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