Granular-type modified polytetrafluoroethylene dispersions and fused articles prepared therefrom
OwnerNorman Ernest Cloughinventor
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Abstract
An aqueous dispersion of modified granular PTFE particles is sprayed or cast to form a sheet. The sheet is then dried and the modified granular particles fused together to form an open network of fused interconnected particles that define a tortuous network of voids through the sheet. It has been found that when the modified granular-type PTPE aqueous dispersions are employed, the resulting fused sheets are stronger than when the usual unmodified PTFE homopolymer of the granular-type is used.
Claims9
A porous material formed of particles of a non-melt-processible granular PTFE copolymer wherein the comonomer units compose less than 2% by weight of the polymer and wherein the particles are fused together to form a network of fused particles in which the network defines a tortuous path of interconnected voids between the fused interconnected particles.
Process for forming a porous PTFE material which comprises:
- (a) forming an aqueous dispersion of particles of a non-melt-processible granular PTFE copolymer wherein the comonomer units compose less than 2% by weight of the copolymer;
- (b) forming said dispersion into a coating on a substrate;
- (c) drying the coating;
- and
- (d) heating the coating to fuse together the particles to form a network of fused particles in which the network defines a tortuous path of interconnected voids between the fused interconnected particles.
Dependencies are inferred from the claim text.