Abstract: A method for treating the surface of a thin porous film material of tetrafluoroethylene resin is disclosed, which comprises heating said surface to a temperature higher than the thermal decomposition point of said resin so as to decompose and remove part of said surface. The resulting thin porous film material of tetrafluoroethylene resin has an adhesive surface while retaining the desired pore size, hardness, and degree of penetration of adhesive.

Abstract: A method for treating the surface of a thin porous film material of tetrafluoroethylene resin is disclosed, which comprises heating said surface to a temperature higher than the thermal decomposition point of said resin so as to decompose and remove part of said surface. The resulting thin porous film material of tetrafluoroethylene resin has an adhesive surface while retaining the desired pore size, hardness, and degree of penetration of adhesive.

Abstract: A method for treating the surface of a thin porous film material of tetrafluoroethylene resin is disclosed, which comprises heating said surface to a temperature higher than the thermal decomposition point of said resin so as to decompose and remove part of said surface. The resulting thin porous film material of tetrafluoroethylene resin has an adhesive surface while retaining the desired pore size, hardness, and degree of penetration of adhesive.

Abstract: An antithrombogenic material is described, comprising an expanded polytetrafluoroethylene base having a collagen layer provided on the surface thereof, and further provided thereon a composite layer of collagen and a mucopolysaccharide, and said collagen is crosslinked with a crosslinking agent.

Abstract: A tubular prosthesis having a composite structure comprising (i) tubular polytetrafluoroethylene having a microfibrous structure comprising small nodes interconnected with fibrils and (ii) materials which can be absorbed by a living body wherein (a) said polytetrafluoroethylene has a greater average fibril length on the outer surface than on the inner surface, and the fibrous structure of said polytetrafluoroethylene varies continuously across the thickness of the tube wall wherein said inner surface has said fibrous structure being predominantly oriented along the axial direction and said outer surface has said fibrous structure being predominantly oriented along the concentric direction; and (b) said materials which can be absorbed by a living body are collagen, at least one of albumin and chitosan, and heparin, and are distributed in such a manner that collagen is present in the portion of the tube wall which is closest to the outer surface thereof while at least one of albumin and chitosan is present in t

Abstract: A liquid membrane is disclosed, which comprises a solvent, an active species capable of facilitated transport of a specific gas, and a support for maintaining a liquid body which has a mixture of said solvent and active species dissolved therein, said support being a porous polytetrafluoroethylene film one surface of which is hydrophobic and the other of which is hydrophilic.

Abstract: A liquid membrane is disclosed, which comprises a solvent, an active species capable of performing facilitated transport of a specific gas, and a support for maintaining a liquid mixture of the solvent and the active species, wherein the active species has the structure represented by the following formula: ##STR1##

Abstract: Apparatus for manufacturing a porous polytetrafluoroethylene material comprising extruding or rolling or a process consisting of the both an unsintered polytetrafluoroethylene mixture containing a liquid lubricant, and carrying out simultaneously next four steps of (a) evaporating a liquid lubricant, (b) stretching the molded articles in an unsintered condition, (c) sintering the same in a stretched condition, and (d) stretching the same in a sintered condition at an atmospheric temperature of more than 390.degree. C. to obtain mechanical strengths such as a Young's modulus of more than 10000 kg/cm.sup.2, and a matrix tensile strength of more than 1100 kg/cm.sup.2.

Abstract: A process for producing a tube or rod of a polytetrafluoroethylene is described. The process comprises molding a polytetrafluoroethylene containing a liquid lubricant into a tube or rod by a paste process, removing the liquid lubricant, stretching the tube or rod in the lengthwise direction, and thereafter, by sintering the stretched tube or rod at a temperature of at least 327.degree. C. wherein the stretching of the tube or rod is carried out by the use of at least one pair of heating rolls which are each provided with a plurality of grooves. The process provided uniform stretching making it possible to produce a tube or rod with very small internal diameter.