Porous products and process therefor
AssigneeW. L. Gore & Associates, Inc.
InventorRobert W. Gore
Life of this patent
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Abstract
This invention provides a tetrafluoroethylene polymer in a porous form which has an amorphous content exceeding about 5% and which has a micro-structure characterized by nodes interconnected by fibrils. The material has high porosity and high strength. It can be used to produce all kinds of shaped articles such as films, tubes, rods, and continuous filaments. Laminations can be employed and impregnation and bonding can readily be used to produce a large variety of articles. Compressed articles of very high strength can also be produced from these porous forms.
Claims77
A porous material consisting essentially of highly crystalline polytetrafluoroethylene polymer, which material has a microstructure characterized by nodes interconnected by fibrils and has a matrix tensile strength in at least one direction above about 7,300 psi.
A porous material consisting essentially of polytetrafluoroethylene polymer, which material has a microstructure characterized by nodes interconnected by fibrils and has a matrix tensile strength in at least one direction above 9290 psi, which material has been heated to a temperature above the crystalline melt point of said polymer and has a crystallinity below about 95%.
A laminated structure comprising (a) a first shaped article formed of a porous material made of a tetrafluoroethylene polymer, which material has a microstructure characterized by nodes interconnected by fibrils and has a matrix tensile strength in at least one direction above about 7,300 psi, and (b) a second shaped article bonded to said first shaped article.
An improvement in coaxial cable of the type comprising an inner conductor, an insulating core, and an outer metallic shield, the improvement comprising:
- a core formed of porous poly(tetrafluoroethylene) tape wrapped around the conductor, the poly(tetrafluoroethylene) having a microstructure characterized by nodes interconnected by fibrils, a matrix tensile strength in at least one direction above about 9290 psi, and a crystallinity below about 95%.
A porous material made of a tetrafluoroethylene polymer, which material has a microstructure characterized by nodes interconnected by fibrils, which material (a) has a matrix tensile strength in at least one direction above about 9290 psi, (b) has been heated to a temperature above 327.degree. C. and has a crystallinity below about 95%, and (c) has a thermal conductivity between about 0.17 Btu/hr/sq.ft./.degree.F./in. and 0.85 Btu/hr/sq.ft./.degree.F./in.
A porous material made of a tetrafluoroethylene polymer, which material has a microstructure characterized by nodes interconnected by fibrils, which material (a) has a matrix tensile strength in at least one direction above about 9290 psi, (b) has been heated to a temperature above 327.degree. C. and has a crystallinity below about 95%, and (c) has a dielectric constant of 1.2-1.8.
A porous material made of a tetrafluoroethylene polymer, which material has a microstructure characterized by nodes interconnected by fibrils, which material (a) has a matrix tensile strength in at least one direction above about 9290 psi, (b) has been heated to a temperature above 327.degree. C. and has a crystallinity below about 95%, and (c) has a permeability to nitrogen of from about 1.times.10.sup.-8 to 1.times.10.sup.-1 metric units.
A filled structure comprising
- (a) a shaped article formed of a porous material made of a tetrafluoroethylene polymer which material has a microstructure characterized by nodes interconnected by fibrils and a matrix tensile strength in at least one direction above about 7,300 psi, and
- (b) a filler within the pores of said shaped article.
An impregnated structure comprising
- (a) a shaped article formed of a porous material made of a tetrafluoroethylene polymer which material has a microstructure characterized by nodes interconnected by fibrils and a matrix tensile strength in at least one direction above about 9290 psi, and
- (b) a polymer impregnated within the pores of the said shaped article.
Dependencies are inferred from the claim text.