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US 2009/0212469 A1Published application
Methods of making a mixture for a ptfe membrane with inorganic materials, and compositions related thereto
AssigneeGeneral Electric Company
InventorGopakumar Thottupurathu
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Abstract
Method for making a mixture used in the production of a polytetrafluoroethylene (PTFE) membrane including porous inorganic materials. The mixture includes PTFE resin, a lubricating agent, and a porous inorganic material. The mixture may be further processed to form a PTFE membrane.
Claims18
A method for making a polytetrafluoroethylene membrane comprising porous inorganic materials, the method comprising the steps of:
- (a) mixing a polytetrafluoroethylene resin having a weight, a lubricating agent having a weight, and a porous inorganic material having a weight,
- wherein the weight of the lubricating agent comprises between 15 and 25 percent of the weight of the polytetrafluoroethylene resin,
- wherein the weight of the porous inorganic material comprises up to 10 percent of the weight of the polytetrafluoroethylene resin, and
- wherein the porous inorganic material has at least one dimension less than 100 nm;
- (b) forming a preform comprising a mixture of the polytetrafluoroethylene resin, the lubricating agent, and the porous inorganic material;
- (c) extruding the preform to form a tape having a thickness between 1 and 100 mil;
- (d) calendaring the tape to facilitate evaporation of the lubricating agent;
- (e) tentering the tape through biaxially stretching in a first direction and a second direction perpendicular to the first direction to form a membrane;
- and
- (f) sintering the membrane at a temperature between 400° F. and 750° F. for a period of time between 1 and 120 seconds, wherein the membrane after sintering has a thickness between 0.05 and 20 mil.
7 more elements
A method of incorporating a porous inorganic material into a mixture comprising a polytetrafluoroethylene resin and a lubricating agent, the method comprising the steps of:
- (a) mixing the polytetrafluoroethylene resin with the lubricating agent in a V blender for a period of time between 1 and 60 minutes to form a resin/lubricant mixture;
- (b) wicking the resin/lubricant mixture for a period of time between 1 and 120 hours;
- and
- (c) mixing the resin/lubricant mixture with the porous inorganic material in a V blender for a period of time between 1 and 60 minutes;
- wherein a weight of the lubricating agent comprises between 15 and 25 percent of a weight of the polytetrafluoroethylene resin,
- wherein a weight of the porous inorganic material comprises up to 10 percent of the weight of the polytetrafluoroethylene resin, and
- wherein the porous inorganic material has at least one dimension less than 100 nm.
4 more elements
A composition comprising:
- a polytetrafluoroethylene resin;
- a lubricating agent comprising an isoparaffinic solvent;
- and
- a porous inorganic material;
- wherein a weight of the lubricating agent comprises between 15 and 25 percent of a weight of the polytetrafluoroethylene resin;
- wherein a weight of the porous inorganic material comprises up to 10 percent of the weight of the polytetrafluoroethylene resin;
- and
- wherein the porous inorganic material has at least one dimension less than 100 nm and has a specific surface area greater than 50 m2/g.
5 more elements
Dependencies are inferred from the claim text.