Abstract: A porous polytetrafluoroethylene material is disclosed having a molecular microfibrous structure having, at one surface, a strong orientation in a given direction and, at another opposite surface, a strong orientation and a direction at right angles to the first, in which the orientation of the microfibrous structure progressively changes from one surface to the other. A process for preparing such an element is also disclosed.

Abstract: A precision filter made entirely of fluororesin having both a high corrosion and high heat resistance. A plurality of tubular filtering elements are arranged in a fluororesin container. Each tubular filtering element has a polytetraethylene tubular filtering film closed at one end and arranged over or inserted into a fluororesin tubular support. The tubular filtering elements are connected to a cover structure, on the inner surface of which is formed a groove for communicating the tubular filtering elements to one of the liquid inlet and liquid outlet provided in the cover structure.

Abstract: An electrochromic display device and apparatus for producing such a device including a display electrode, a confronting electrode, and an electrolyte-impregnated porous layer disposed between the electrodes. The porous member has an average pore diameter of 0.1 to 50 .mu.m with porous spaces occupying at least 30% by volume of the porous member. Pigment is held in the porous spaces to an extent of 1 to 50% by volume of the porous spaces. With this construction, the display device provides an excellent display background.

Abstract: A porous polytetrafluoroethylene material is disclosed having a molecular microfibrous structure having, at one surface, a strong orientation in a given direction and, at another opposite surface, a strong orientation and a direction at right angles to the first, in which the orientation of the microfibrous structure progressively changes from one surface to the other. A process for preparing such an element is also disclosed.

Abstract: A vascular prosthesis comprising a porous tubing of polytetrafluoroethylene containing an anti-coagulant substance and bonded to its outside surface a porous elastomer coating containing substance which counteracts the anti-coagulant substance is disclosed.

Abstract: A tubular organic prosthesis comprising a porous tubing of polytetrafluoroethylene and elastic fibers provided helically on its outside surface.

Abstract: A tubular prosthesis comprising a porous tubing of polytetrafluoroethylene having a micro structure composed of fibers and nodes connected to one another by said fibers, said fibers being radially distributed, and a porous coating on the outside surface of said polytetrafluoroethylene tubing and a process for producing the same is disclosed.

Abstract: A process for preparing a porous material having a fine pore size which comprises preparing a solution comprising resin comprising a vinylidene fluoride/tetrafluoroethylene copolymer, a vinylidene fluoride polymer or a mixture thereof and at least a solvent for the resin and a non-solvent for the resin, and removing the solvent and the non-solvent from the solution, wherein a part of the resin is dissolved or swollen during the removal of the solvent and non-solvent.

Abstract: A vascular prosthesis having a composite structure of a porous tubing of polytetrafluoroethylene with polyethyleneimine in the pores of the tubing, the polyethyleneimine being water-insolubilized with the amino groups quaternized and having heparin ionically bound thereto.

Abstract: The apparatus heat fixes a toner image on one surface of a wet-developed, image-carrying copy sheet while maintaining the opposite surface of the sheet in sliding contact with the surface of a heated plate. A portion of the heating surface is formed with a concave surface, or a curved surface having a positive curvature, and there is provided a guide roller for introducing the sheet onto the curved surface. When introduced onto the curved surface, the sheet achieves a good sliding contact with the heating surface by virtue of its resiliency without application of a back pressure thereto, thus accomplishing an efficient heat fixing without any accompanying degradation in the image quality.

Abstract: The apparatus comprises a projection optical system and a copying system. The projection optical system can project an image of an original either onto a screen or to an exposing position of the copying system by switching between two positions. The copying system comprises a plurality of chargers providing different charging conditions in accordance with the types and sizes of copy sheets, by utilizing a change-over switch. A plurality of switches adapted for use with copy sheets of different lengths are arranged along the path of movement of a sheet of paper and, when the switch corresponding to the particular length of copy sheet desired is actuated, the movement of the sheet of paper is stopped, so that the central portion of the copy sheet can be brought into alignment with the optical axis for exposing at all times regardless of the difference in the length of copy sheets.

Abstract: A tubular organic prosthesis comprising a porous tubing of polytetrafluoroethylene and elastic fibers provided helically on its outside surface.