Process for producing fiber and method for producing catalyst layer
View Patent ↗To provide a process whereby an ultrafine fiber of a fluorinated ion exchange resin can be produced easily at low cost, and a method whereby a catalyst layer having a high gas diffusion property can be produced easily at low cost. A process for producing a fiber by spinning a spinning solution containing a fluorinated ion exchange resin and a solvent by a dry spinning method, or producing an electrically conductive composite fiber by spinning n types (where n is an integer of at least 2) of spinning solutions, of which at least one type contains a fluorinated ion exchange resin and a solvent, and at least one type contains an electrically conductive material and a solvent, simultaneously by a dry spinning method, wherein the spinning solution which is being spun by the dry spinning method, is stretched by a gas stream; and a method for producing a catalyst layer, which comprises accumulating the fiber produced by such a process to form a non-woven fabric thereby to obtain a catalyst layer having the non-woven fabric.
1. A process for producing a fiber by a spinning method which comprises:
discharging n types of spinning solutions, wherein n is an integer of at least 2, of which at least one type comprises a fluorinated ion exchange resin and a solvent, simultaneously from discharge nozzles,
and evaporating solvents from the discharged n types of spinning solutions, wherein the n types of spinning solutions, which are combined and spun by the spinning method, are stretched by a gas stream, and wherein at least two of the n types of spinning solutions are discharged from different discharge nozzles.
2. The process for producing a fiber according to claim 1 , wherein at least one type of the spinning solutions comprises an electrically conductive material and a solvent.
3. The process for producing a fiber according to claim 2 , wherein the electrically conductive material is a catalyst comprising a metal.
4. A process for producing an electrically conductive composite fiber by a spinning method, the process comprises:
discharging n types of spinning solutions, wherein n is an integer of at least 2, of which at least one type comprises a fluorinated ion exchange resin and a solvent, and at least one type comprises an electrically conductive material and a solvent, simultaneously from discharge nozzles, and
evaporating the solvents from the discharged n types of spinning solutions, wherein the n types of spinning solutions, which are combined and spun by the spinning method, are stretched by a gas stream, and wherein the n types of spinning solutions are discharged from n different discharge nozzles.
5. The process for producing an electrically conductive composite fiber according to claim 4 , wherein the electrically conductive material is a catalyst comprising a metal.
6. A method for producing a catalyst layer for a membrane/electrode assembly for a polymer electrolyte fuel cell, which comprises accumulating the fiber produced by the process as defined in claim 3 to form a non-woven fabric, thereby obtaining a catalyst layer having the non-woven fabric.
7. A method for producing a catalyst layer for a membrane/electrode assembly for a polymer electrolyte fuel cell, which comprises accumulating the fiber produced by the process as defined in claim 5 to form a non-woven fabric, thereby obtaining a catalyst layer having the non-woven fabric.
8. The process for producing a fiber according to claim 1 , wherein the gas stream is parallel or oblique to the direction of the spinning solutions from the discharge nozzles.
9. The process for producing a fiber according to claim 1 , wherein the gas stream is pressurized.
10. The process for producing a fiber according to claim 1 , wherein the gas stream is an inert gas stream.
11. The process for producing a fiber according to claim 1 , wherein a blowoff amount of the gas stream is at least 0.5 L/min and at most 100 L/min.
12. The process for producing a fiber according to claim 4 , wherein the gas stream is parallel or oblique to the direction of the spinning solution from the discharge nozzles.
13. The process for producing a fiber according to claim 4 , wherein the gas stream is pressurized.
14. The process for producing a fiber according to claim 4 , wherein the gas stream is an inert gas stream.
15. The process for producing a fiber according to claim 4 , wherein a blowoff amount of the gas stream is at least 0.5 L/min and at most 100 L/min.
16. The process for producing a fiber according to claim 1 , wherein the discharge nozzles are surrounded by a gas stream blowing nozzle.
17. The process for producing a fiber according to claim 16 , wherein each of the nozzles discharge one of the n types of the spinning solutions, and wherein the nozzles are tubes.