A method may produce a heat-resistant resin composite excellent in heat resistance and bending properties. This heat-resistant resin composite is constituted of a matrix resin and reinforcing fibers dispersed in the matrix resin. The matrix resin is constituted of a heat-resistant thermoplastic polymer having a glass transition temperature of 100° C. or higher, and a polyester-based polymer comprising a terephthalic acid unit (A) and an isophthalic acid unit (B) at a copolymerization proportion (molar ratio) of (A)/(B)=100/0 to 40/60. The proportion of the heat-resistant thermoplastic polymer in the composite is 30 to 80 wt %.

A method may produce a heat-resistant resin composite excellent in heat resistance and bending properties. This heat-resistant resin composite is constituted of a matrix resin and reinforcing fibers dispersed in the matrix resin. The matrix resin is constituted of a heat-resistant thermoplastic polymer having a glass transition temperature of 100° C. or higher, and a polyester-based polymer comprising a terephthalic acid unit (A) and an isophthalic acid unit (B) at a copolymerization proportion (molar ratio) of (A)/(B)=100/0 to 40/60. The proportion of the heat-resistant thermoplastic polymer in the composite is 30 to 80 wt %.

The present invention relates to a porous sheet comprising cellulose fibers having an average fiber diameter ranging from 20 to 500 nm; cut fibers having an average fiber diameter ranging from 1.5 to 20 μm; and a hydrophilic polymer binder, wherein an amount of the cut fibers is 1% by weight or more and 80% by weight or less based on the total weight of the cellulose fibers and the cut fibers, and an amount of the hydrophilic polymer binder is 5 parts by weight or more and 30 parts by weight or less with respect to 100 parts by weight of the total weight of the cellulose fibers and the cut fibers. The porous sheet of the present invention can exhibit a superior strength (in particular, both tear strength and tensile strength), and exhibits a superior performance as a separator for an electrochemical device.

The present invention relates to a porous sheet comprising cellulose fibers having an average fiber diameter ranging from 20 to 500 nm; cut fibers having an average fiber diameter ranging from 1.5 to 20 μm; and a hydrophilic polymer binder, wherein an amount of the cut fibers is 1% by weight or more and 80% by weight or less based on the total weight of the cellulose fibers and the cut fibers, and an amount of the hydrophilic polymer binder is 5 parts by weight or more and 30 parts by weight or less with respect to 100 parts by weight of the total weight of the cellulose fibers and the cut fibers. The porous sheet of the present invention can exhibit a superior strength (in particular, both tear strength and tensile strength), and exhibits a superior performance as a separator for an electrochemical device.

The present invention relates to a parchmentized fibrous support containing parchmentizable synthetic fibers parchmentized with sulfuric acid, the process for making such a support and the use thereof.

The present invention relates to a parchmentized fibrous support containing parchmentizable synthetic fibers parchmentized with sulfuric acid, the process for making such a support and the use thereof.

A paper suitable for use as a separator or thermal or fire insulation for use in or with electrochemical cells, and an electrochemical cell comprising the same, the paper having 90 to 99 weight percent aramid fibrous pulp comprising aramid polymer fibrils and 1 to 10 weight percent polyvinylpyrrolidone present as a coating on the surface of the fibers, the paper having a thickness of 10 to 40 micrometers and a tensile strength of at least 15 megapascals or greater.

A paper suitable for use as a separator or thermal or fire insulation for use in or with electrochemical cells, and an electrochemical cell comprising the same, the paper having 90 to 99 weight percent aramid fibrous pulp comprising aramid polymer fibrils and 1 to 10 weight percent polyvinylpyrrolidone present as a coating on the surface of the fibers, the paper having a thickness of 10 to 40 micrometers and a tensile strength of at least 15 megapascals or greater.

A method is provided for manufacturing a polyimide fiber paper intermediate structure, which includes: a short fiber preparing step for preparing shaved short fibers of a non-thermoplastic polyimide; and an intermediate structure forming step for forming a polyimide fiber paper intermediate structure in which the short fibers are temporarily bonded using a water-soluble and/or water-insoluble thermoplastic polymer having a melting point lower than a glass transition point of a polyimide.

A method is provided for manufacturing a polyimide fiber paper intermediate structure, which includes: a short fiber preparing step for preparing shaved short fibers of a non-thermoplastic polyimide; and an intermediate structure forming step for forming a polyimide fiber paper intermediate structure in which the short fibers are temporarily bonded using a water-soluble and/or water-insoluble thermoplastic polymer having a melting point lower than a glass transition point of a polyimide.