Abstract: A heat-resistant fiber paper sheet which is formed from staple fibers made from a heat-resistant organic polymer, undrawn or low ratio drawn para-aromatic polyamide staple fibers, and an organic resin binder and/or fibrids comprising a heat-resistant organic polymer as main components, wherein the amount of said staple fibers is 45 to 97 percent by weight based on the total amount of said heat-resistant fiber paper sheet; the total amount of said organic resin binder and/or said fibrids is 3 to 55 percent by weight based on the total amount of said heat-resistant fiber paper sheet; and said organic resin binder is cured, and/or said undrawn or low ratio drawn para-aromatic polyamide staple fibers and said fibrids are partially softened, deformed and/or melted to exhibit the actions of binders.

Abstract: A nonwoven fabric made of filaments, which comprises filaments formed from a fiber-forming thermoplastic polymer and satisfies all of the following conditions (A) to (D). (A) The fiber bundles are present in a range of 5-70 per centimeter in any cross-section parallel to the direction of thickness of the nonwoven fabric. (B) The total area occupied by the fiber bundles is in a range of 5-70% of the cross-sectional area of any cross-section perpendicular to the direction of thickness of the nonwoven fabric. (C) The apparent density is 0.10-0.50 g/cm3. (D) The cut ends of the fibers on the nonwoven fabric surface are present in a range of 5-100 per mm2 of surface area.

Abstract: A water vapor-permeable waterproof fabric free from an environmental pollution problem upon being discarded is formed by coating a substrate fiber fabric with a composite coating layer including a lower layer (A) directly formed on the substrate fabric and an upper layer (B) formed on the lower layer (B), wherein the lower and upper layers are formed from one of polyetherester elastomers different from each other and each containing polyalkylene glycol (PAG) residues, and satisfy the following requirements: (a) in the polyetherester elastomer (PEEA), the polyalkylene glycol residues contain 90% by weight or more of polytetramethylene glycol residues; (b) in the polyetherester elastomer (PEEB), the polyalkylene glycol residues contain 50% by weight or more of polyethylene glycol residues; (c) the thickness of the composite coating layer is 5 to 50 &mgr;m; and (d) the lower layer (A) is in an amount of 5 to 40% by weight based on the total weight of the composite coating layer.

Abstract: A wholly aromatic polyamide (aramid) fiber synthetic paper sheet includes 70-96 wt % of an aramid staple fiber component which includes 30 wt % or more of a para-type aramid staple fibers each having two or more annular projections spaced from each other and having an average ratio R/&ggr; of the largest diameter R of the annular projections to the smallest diameter &ggr; of the annular projection-free portions of the staple fiber, of 1.1 or more, and 4-30 wt % of a binder component, namely a resinous binder and/or heat resistant fibrids.

Abstract: A heat resistant fiber sheet composed of staple fibers consisting of a heat resistant organic high molecular polymer and fibrids consisting of a heat resistant organic high molecular polymer as main components, having excellent heat resistance, dimensional stability to heat, interlaminar peeling strength, electric insulation resistance under a high humidity, etc., and also good resin impregnating property in spite of having a high bulk density, and especially suitable for a base substrates for an electric insulating material and a laminate for an electric circuit, is obtained by setting the amount of the staple fibers occupying in the total amount of the sheet as 40 to 97% by weight and the amount of the fibrids as 3 to 60% by weight and partially softening and/or melting the fibrids so as to act as a binder.

Abstract: A nonwoven fabric made of filaments, which comprises filaments formed from a fiber-forming thermoplastic polymer and satisfies all of the following conditions (A) to (D).

Abstract: Aromatic polyamide fibers which have a crystalline structure having (1) crystal size (A) in a (110) plane of 7.5 nm, (2) crystal size (B) in a (200) plane of 8.2 nm and (3) a product A×B of 61.50 to 630.00, and exhibit a thermal linear expansion coefficient of −1.0×10−6/° C. to −7.5×10−6/° C. and thus a high dimensional stability even upon moisture-absorbing and desorbing, are useful for forming a resin-reinforcing fiber sheet, a pre-preg containing the fiber sheet, and a laminate for, for example, an electric insulating material or electric circuit board, having an excellent cutting, shaving, perforating or laser processability and capable of forming a smooth cut, shaved or perforated face.

Abstract: A biodegradable cellulose acetate foam with a foam cell size of 0.001-0.8 mm and an apparent density of 0.01-0.27 g/cm3, and a biodegradable cellulose acetate foam wherein the foam is treated with a weak alkali solution, and has an acetylation degree of 45-60% and no acetic acid odor.

Abstract: To provide a non-impregnated type substrate useful as a base fabric for artificial leather, which is superior in leather-like handle, air permeability and lightness properties; and an artificial leather made therefrom. A non-impregnated type substrate useful as a base fabric for artificial leather, which is a fiber assembly constituted by matrix fibers and binder fibers having an elastic polymer arranged on the surface thereof, the binder fibers being dispersed in and head-bonded to the matrix fibers, wherein the elastic polymers are contained within a specified amount, the bonds between binder fibers and matrix fibers by the elastic polymer are formed within specified proportions and with particular configurations, and the substrate has a density of 0.15 to 0.45 g/cm.sup.3.

Abstract: An aromatic polyamide flat filament useful for producing a twisted yarn having a high utilization of tensile strength thereof, has a flatness of cross-sectional profile thereof of 1.5 to 5, an individual filament thickness of 1 denier or more but less than 50 deniers, a tensile strength of 18 g/denier or more, an ultimate elongation of 3.5% or more, and a Young's modulus of 400 g/denier or more.

Abstract: Surface frictional characteristics of a wholly aromatic polyamide fiber are desirably modified by applying to the fiber at least 0.05% by weight, based on the fiber, of a reaction product of a polyoxyethylene adduct of glyceride having at least one hydroxyl group in the molecule with a dibasic acid and/or a dibasic anhydride. Preferably, prior to the application of the reaction product, at least 0.01% by weight of an inorganic compound powder is applied to the fiber.

Abstract: An undrawn polyester yarn comprising 0.2 to 10% by weight of a polymer having a recurring unit structure represented by the following formula (1): ##STR1## wherein R.sub.1 and R.sub.2 stand for substituents consisting of optional atoms selected from C, H, N, O, S, P and halogen atoms, with the proviso that the sum of the molecular weights of R.sub.1 and R.sub.2 is equal to or more than 40, and n is a positive integer, and having a molecular weight equal to or more than 1000, the elongation increase ratio (I) of the undrawn polyester yarn, represented by the following formula (2), being equal to or more than 8%: ##EQU1## wherein EL.sub.b stands for the residual elongation (%) of the undrawn yarn and EL.sub.o stands for the residual elongation (%) of a corresponding undrawn polyester yarn substantially free of the polymer represented by the formula (1).

Abstract: A high twist polyester multifilament yarn having a twist of a twist multiplier K within a range between 15,000 and 25,000, made from polyester filaments consisting essentially of a copolymer of two or more monomers selected from the group consisting of ethylene terephthalate, trimethylene terephthalate and tetramethylene terephthalate and/or a blend of two or more polymers of the respective monomers and having a breaking elongation of not more than 60% and a shrinkage in boiling water of not more than 6%. A woven or knitted crepe fabric obtained by employing such a high twist yarn has a desirable pebble configuration.

Abstract: A polyester multifilament consisting essentially of a filament groups (I) and (II). The filament group (I) is composed of a polyester selected from the group consisting of polyethylene terephthalate, polytrimethylene terephthalate and polytetramethylene terephthalate, and/or a blend and/or copolymer comprising at least two members selected from the polyesters. The filament group (II) is composed of a substrate composed of a polyester selected from the group consisting of polyethylene terephthalate, polytrimethylene terephthalate and polytetramethylene terephthalate, and/or a blend and/or a copolymer comprising at least two members selected from the polyesters and at least one polymer selected from the group consisting of styrene type polymers, methacrylate type polymers and acrylate type polymers, which is added to said substrate in an amount of 0.4 to 8% by weight based on the substrate.

Abstract: A polyester multifilament consisting essentially of filament groups (I) and (II). The filament group (I) is composed of a polyester selected from the group consisting of polyethylene terephthalate, polytrimethylene terephthalate and polytetramethylene terephthalate, and/or a blend and/or copolymer comprising at least two members selected from the polyesters. The filament group (II) is composed of a substrate composed of a polyester selected from the group consisting of polyethylene terephthalate, polytrimethylene terephthalate and polytetramethylene terephthalate, and/or a blend and/or a copolymer comprising at least two members selected from the polyesters and at least one polymer selected from the group consisting of styrene type polymers, methacrylate type polymers and acrylate type polymers, which is added to said substrate in an amount of 0.4 to 8% by weight based on the substrate.

Abstract: A hollow polyester fiber with excellent antistatic properties composed of a single polymeric component and having a hollow extending along the longitudinal axis thereof and in which the hollow ratio is at most 15%, which fiber contains (a) a polyoxyalkylene glycol substantially non-reactive with said polyester and (b) an ionic antistatic agent, dispersed through the fiber in an amount of at most 3% by weight based on the weight of the fiber, and wherein the polyoxyalkylene glycol (a) is predominantly dispersed in a core portion of the fiber in a high density. The fiber also has excellent tensile strength, resistance to fibrillation and dyeing properties.

Abstract: A process for the preparation of leatherlike sheet materials which comprises: preparing hollow composite fibers, each composed of 32 to 72 alternately arranged segments of polyester or polyamide and polystyrene which are mutually adhered side-by-side and encompass a hollow space, and which extend along the longitudinal axis of the fiber to form a tubular body, the hollow composite fiber having a denier of 1 to 20, and each segment having a denier of 0.01 to 0.5; forming a fabric using thus prepared hollow composite fibers; removing the polystyrene segments with a solvent thereof from the hollow composite fibers; and applying an elastic polymer to the fabric. The resultant leatherlike sheet materials have fine touch, excellent repulsive elasticity and excellent wrinkle resistance similar to natural suede. The hollow ratio (ratio by volume of the hollow space to the sum of the volume of the polyester or polyamide segments, the polystyrene segments and the hollow space) is 2-15%.

Abstract: The present invention relates to a method of producing a twisted polyester filament yarn having a high level of twist used for a woven or knitted crepe fabric.A method of this invention comprises imparting a high level of twist to a polyester filament yarn which has particular properties, and heat setting said twisted polyester filament yarn. The first of these properties which the polyester filament yarn has is that a boil-off shrinkage in boiling water is in the range of 0% to 5%. The second is that a thermal shrinkage stress at 140.degree. C. in hot air is more than 0.03 g/de. The third is that a ratio of a thermal shrinkage stress at 180.degree. C. in hot air to a thermal shrinkage stress at 140.degree. C. is more than 1.0.The polyester filament yarn which has above mentioned properties can be obtained by repeating heat treatment several times at a temperature from 160.degree. C. to 220.degree. C.