Abstract: A multilayer porous membrane comprising a porous membrane containing a polyolefin resin as a main component; and a porous layer containing an inorganic filler and a resin binder and laminated on at least one surface of the porous membrane; wherein the porous membrane has an average pore size d=0.035 to 0.060 ?m, a tortuosity ?a=1.1 to 1.7, and the number B of pores=100 to 500 pores/?m2, which are calculated by a gas-liquid method, and the porous membrane has a membrane thickness L=5 to 22 ?m.

Abstract: A separator for a lithium ion secondary battery with an alloy based negative electrode, wherein a dynamic friction coefficient of at least one surface is 0.1 or more and 0.4 or less, and a method for manufacturing the same.

Abstract: A method for membrane filtration purification of suspended water, comprising filtering the suspended water under an external pressure through a porous hollow fiber membrane comprising a polyolefin, a copolymer of olefin and halogenated olefin, halogenated polyolefin or a mixture thereof and having an open area ratio in an outer surface of not less than 20% and a pore diameter in a minimum pore diameter layer of not smaller than 0.03 ?m and not larger than 1 ?m.

Abstract: A separator for a lithium ion secondary battery with an alloy based negative electrode, wherein a dynamic friction coefficient of at least one surface is 0.1 or more and 0.4 or less, and a method for manufacturing the same.

Abstract: The present invention provides a polyolefin microporous membrane made of a polyolefin resin and an inorganic particle, and the puncture strength of the microporous membrane is 3 N/20 ?m or more and the membrane thickness retention ratio in penetration creep is 16% or more, thereby being excellent in safety and long-term reliability, and a separator for a nonaqueous electrolyte battery, and the like can be provided.

Abstract: A separator of the present invention for a nonaqueous electrolyte secondary battery is obtained by fluorinating a polyolefin based resin. A contact angle of the separator with a nonaqueous solvent electrolyte is 40° or less a shutdown temperature of the separator is 170° C. or less. Further, a multilayered separator of the present invention for a nonaqueous electrolyte secondary battery includes a plurality of layers, at least one of which is the foregoing separator for a nonaqueous electrolyte secondary battery. These separators for nonaqueous electrolyte secondary battery have both a favorable electrolyte-retaining characteristic and a suitable shutdown performance.

Abstract: A microporous film, characterized in that it is prepared by a method comprising melting and kneading a polyolefin resin, inorganic particles and a plasticizer, forming the resultant mixture into a sheet, subjecting the rejecting the resultant sheet to a biaxial stretching treatment of a surface magnification of not less than 20 and less than 100 times, and then extracting the plasticizer, it has an inorganic particle content of 20 to 60 mass %, and it exhibits a piercing strength of 3.0 N/20 ?m or more.

Abstract: A method for membrane filtration purification of suspended water, comprising filtering the suspended water under an external pressure through a porous hollow fiber membrane comprising a polyolefin, a copolymer of olefin and halogenated olefin, halogenated polyolefin or a mixture thereof and having an open area ratio in an outer surface of not less than 20% and a pore diameter in a minimum pore diameter layer of not smaller than 0.03 ?m and not larger than 1 ?m.

Abstract: A method for membrane filtration purification of suspended water, comprising filtering the suspended water under an external pressure through a porous hollow fiber membrane comprising a polyolefin, a copolymer of olefin and halogenated olefin, halogenated polyolefin or a mixture thereof and having an open area ratio in an outer surface of not less than 20% and a pore diameter in a minimum pore diameter layer of not smaller than 0.03 &mgr;m and not larger than 1 &mgr;m.