Abstract: The present invention provides porous hydrophilic fluoropolymer membranes whose pores are coated with a hydrophilic fluorine-containing copolymer that provides durable hydrophilic properties to the membrane.

Abstract: Composite gasket materials comprising one or more layers of porous fluoropolymer film laminated to one or more layers of expanded-graphite sheet, or a subassembly of one or more layers of expanded-graphite sheet laminated to metal sheet. The composite gasket materials are suitable for use in many applications where asbestos-containing materials are used.

Abstract: A degassing method comprising directing a liquid feed containing gas and bubbles into a breathable membrane to remove the bubbles and then into a deaerating module containing a gas-permeable membrane.

Abstract: An elastic roll of the first embodiment comprises an elastic body layer formed in a thickness not less than 200 .mu.m on a metal core bar; and a covering layer with a release property formed in a thickness ranging from 3 .mu.m to 200 .mu.m on the surface of the elastic body, the covering layer being formed of a composite material composed of fibrillated polytetrafluoroethylene and elastomer having releasing properties. An elastic fixing roll of second embodiment comprises a heat-conductive elastic body layer formed of heat-resistant elastomer in a thickness not less than 200 .mu.m on a metal core bar; an oil-resistant layer formed of oil-resistant elastomer in a layer thickness ranging from 3 .mu.m to 200 .mu.m on the elastic body layer; and a covering layer having a release property and formed of a composite material composed of fibrillated polytetrafluoroethylene and elastomer with a release property in a thickness ranging from 3 .mu.m to 200 .mu.m on the oil-resistant layer.

Abstract: A wound dressing is provided comprising a layer of chitin affixed to a layer of porous, expanded polytetrafluoroethylene (PTFE). The chitin may be laminated to the PTFE or it may penetrate into and be impregnated in the porous PTFE layer. The composite preferably has a pressure sensitive adhesive applied in a dot pattern on its surface to enable application and securing of the dressing over a wound.

Abstract: A cap for containers used to store volatile liquids is provided characterized by a gas venting port formed in the main body of the cap which is attached to an opening in a container, a filter accomodation space which connects with the aforementioned gas venting port formed in the bottom surface of the main body of the cap, a channel formed in the central portion of a filter assembly installed in the aforementioned filter accomodation space, two hydrophobic porous filter membranes, one installed between the filter assembly and the aforementioned gas venting port and one installed over the innermost end of the aforementioned channel, whereby a liquid passageway is formed, and an aqueous liquid partly, but not completely, fills the interior of the assembly.

Abstract: A degassing tubular device is provided having an inner tube of a porous polymeric resin positioned inside an outer tube of a porous polymeric resin, and having a tube-form body formed from a porous polymeric film interposed between the inner and outer tubes, wherein the porous polymeric film has a mean pore size of 0.2 to 3.0 microns. The inner tube, outer tube and film are preferably all of porous polytetrafluoroethylene.

Abstract: A flexible base material for use in printed circuit boards is provided wherein a sheet of porous, expanded polytetrafluoroethylene is impregnated with a bismaleimide-triazine resin, and the resin is cured therein. The sheet may be laminated to a glass cloth and composites may be produced having a multiplicity of layers of such sheets and glass cloths.

Abstract: As was described above, the present invention makes it possible to achieve a sufficient diminution of the effect of the water-repellent characteristics of polytetrafluoroethylene used as a binding agent. Accordingly, the mixture ratio of polytetrafluoroethylene can be increased so that a sufficient film strength is obtained. Furthermore, a high foam pressure is obtained by forming a fine fibrilized net of polytetrafluoroethylene. Moreover, since the amount of polytetrafluoroethylene used is thus large, the molding characteristics of the product are favorable, and the yield can be increased. Accordingly, a highly reliable product can be obtained at a high yield. As a result, the present invention has the effect of improving the performance and reliability of the fuel cell as a whole, and of increasing the useful life and reducing the cost of the fuel cell. Accordingly, the present invention has great industrial merit.

Abstract: A printed circuit board base prepreg material is provided of a porous, expanded polytetrafluoroethylene (PTFE) membrane or fabric impregnated with a polyimide resin varnish. Upon curing, a printed circuit board base material of porous, expanded PTFE impregnated with polyimide resin is provided. The base material of the invention may be laminated to a glass fabric to improve strength and dimensional stability.

Abstract: A base material for use in making printed circuit boards is provided wherein minute fragments of expanded, porous polytetrafluoroethylene are uniformly mixed into another resin, and the mixture is compressed to form a composite board. In use, the board has an electrically conductive circuit affixed to at least one surface. The other resin may be epoxy, polyester or other similar resin. Laminates of such base board material affixed to a glass cloth or paper sheet may be prepared. The preferred fragment size range is 0.1 to 5 mm average diameter, and the preferred volume ratio of fragments to resin is 0.5 to 2.0.

Abstract: A water-vapor-permeable, waterproof, highly elastic film of expanded, porous, unsintered polytetrafluoroethylene having impregnated within the pores of the porous film, on both sides thereof, a water-vapor-permeable resin, for example, an elastomer containing urethane bonds and a hydrophilic group(s) in its molecular structure. The film of this invention is useful in clothing, tents, and various applications where water vapor transmission characteristics and waterproofness are simultaneously desired. The film has elongation percentage in at least one direction exceeding 40% and durability in repeated stretching to 80% of its elongation percentage of more than 200,000 cycles.