Abstract: A hollow fiber-form porous membrane of vinylidene fluoride resin having a high crystallinity as represented by a crystal melting enthalpy of at least 58 J/g is produced by forming a composition of a vinylidene fluoride resin having a relatively high weight-average molecular weight of at least 3×105 blended with a plasticizer and a good solvent for vinylidene fluoride resin, melt-extruding the composition into a hollow fiber-form film, and solidifying the film by cooling it from an outside thereof by contact with a cooling liquid inert to vinylidene fluoride resin while crystallizing the vinylidene fluoride resin at an appropriately moderate speed. The resultant hollow fiber-form porous membrane is excellent in mechanical strength represented by tensile strength and elongation at break, and also excellent in chemical resistance, thus being effectively used as a water micro-filtration membrane.

Abstract: Monofilaments comprising resin compositions which contain 1% by mass or more of a comonomer component (for example, hexafluoropropylene), have an intrinsic viscosity of 1.3 dl/g or more and a melting point of 165° C. or higher and contain a PVDF-based resin. Owing to the above composition and physical properties, the crystallinity and elastic modulus of the PVDF-based resin are altered. As a result, an appropriate flexibility can be imparted to the monofilaments while preventing deterioration in the mechanical properties.

Abstract: There is provided a porous membrane of vinylidene fluoride resin which has pores of appropriate size and distribution and also excellent mechanical strength represented by tensile strength and elongation at break and is useful as a microfiltration membrane or a separator for batteries. The porous membrane of vinylidene fluoride resin is characterized by the presence in mixture of a crystalline oriented portion and a crystalline non-oriented portion as confirmed by X-ray diffraction, and is produced by subjecting a melt-extruded composition obtained by mixing a vinylidene fluoride resin having a molecular weight distribution which is appropriately broad and high as a whole with a plasticizer and a good solvent for vinylidene fluoride resin, to cooling for solidification from one surface, extraction of the plasticizer and stretching.

Abstract: Monofilaments comprising resin compositions which contain 1% by mass or more of a comonomer component (for example, hexafluoropropylene), have an intrinsic viscosity of 1.3 dl/g or more and a melting point of 165° C. or higher and contain a PVDF-based resin. Owing to the above composition and physical properties, the crystallinity and elastic modulus of the PVDF-based resin are altered. As a result, an appropriate flexibility can be imparted to the monofilaments while preventing deterioration in the mechanical properties.

Abstract: A moistureproof multilayer film, including a composite film having a non-moisture absorbing resin layer and a vapor deposited film of an inorganic oxide or a metal formed on at least one side of the non-moisture absorbing resin layer, the multilayer film having such a layer structure where the vapor deposited film surface of the composite film is laminated through an adhesive layer on a vapor deposited film surface of another composite film or a surface of another non-moisture absorbing resin layer, wherein a total number (n) of the deposited films laminated adjacent to the adhesive layer is 2 to 8, and wherein a moisture permeabihty (W; unit: g/m2.day) as measured under conditions of a temperature of 40° C. and a relative humidity of 100% satisfies a relation represented by equation W≦(1/n)×0.20, and a method for producing the moistureproof multilayer film including heat-treating the multilayer film in a hot dry atmosphere having a temperature lower than 140° C. but not lower than 55° C.

Abstract: Monofilaments comprising resin compositions which contain 1% by mass or more of a comonomer component (for example, hexafluoropropylene), have an intrinsic viscosity of 1.3 dl/g or more and a melting point of 165° C. or higher and contain a PVDF-based resin. Owing to the above composition and physical properties, the crystallinity and elastic modulus of the PVDF-based resin are altered. As a result, an appropriate flexibility can be imparted to the monofilaments while preventing deterioration in the mechanical properties.

Abstract: A high-strength polyesteramide fiber comprising a polyesteramide copolymer is characterized by having a primary peak temperature that is at least 10° C. higher than that of a non-oriented material comprising the polyesteramide copolymer, as measured by dynamic viscoelastometry. A high-strength polyesteramide fiber production process is characterized by comprising a series of steps of melt spinning the polyesteramide copolymer, immediately followed by solidification by cooling in an inert cooling medium having a temperature of 20° C. or lower, thereby obtaining an undrawn filament; enhancing the crystallinity of the undrawn filament to 10 to 30% by weight; and subjecting the undrawn filament having a crystallinity of 10 to 30% by weight to a single- or multi-stage drawing in such a way as to give a total draw ratio of 4.5 times or greater.

Abstract: An electrode-forming composition for providing an activated carbon electrode for an electric double layer capacitor is provide by blending activated carbon, a vinylidene fluoride polymer and a solvent including a plasticizer in addition to a good solvent for the vinylidene fluoride polymer. By applying the electrode-forming composition onto an electroconductive substrate, and selectively removing the solvent preferably by a combination of extraction of the plasticizer with a poor solvent for the vinylidene-fluoride polymer and evaporation of the solvent, it is possible to obtain an activated carbon electrode (polarizable electrode) that has an activated carbon electrode layer exhibiting good adhesion onto the electroconductive substrate and a good flexibility, and therefore has good processability. By using the activated carbon electrodes as polarizable electrodes, it is possible to provide an electric double layer capacitor having improved reliability.

Abstract: A stretched PCTFE (polychlorotrifluoroethylene) film is provided with a good moisture-proofness (low moisture permeability) even at a relatively small thickness and at a small crystallinity The film is characterized by a crystallinity A (%) of 15-75% and a moisture permeability B (mg/m.sup.2.day) at a film thickness of 20 .mu.m, satisfying a relationship of B/(100-A).ltoreq.3.0. The film may suitably be produced through a process characterized by a sequence of a relatively low-temperature melt-extrusion and a low temperature stretching. The film is suitably used for constituting moisture-proof packaged products, such as an EL device or a packaged drug product.