Daiwabo Holdings Co., Ltd.

Daiwabo Polytec Co., Ltd.

Daiwabo Co., Ltd.

Tatsunori Kida

Tomofumi Tanaka

Shuuji Hori

Toyohiko Sano

Hiroyuki Yamamoto

A polyolefin-based split-type conjugate fiber according to the present invention is a polyolefin-based split-type conjugate fiber obtained by composite spinning including a first component containing a polypropylene-based resin and a second component containing a polyolefin-based resin, wherein the first component contains, as a primary component, a polypropylene resin having a Q value (the ratio between the weight average molecular weight Mw and the number average molecular weight Mn) of 6 or greater and a melt flow rate according to JIS K 7210 (MFR at a measurement temperature of 230&#xb0; C. under a load of 2.16 kgf (21.18 N)) of 5 g/10 min or greater and less than 23 g/10 min, and the first component and the second component are adjacent to each other in a cross section of the polyolefin-based split-type conjugate fiber. Also, the polyolefin-based split-type conjugate fiber of the present invention can be obtained by melt spinning the first component and the second component by using a split type conjugate nozzle and drawing the resulting fiber.

Polyolefin-based split-type conjugate fiber, fiber assembly and battery separator using the same and method for producing the same

A battery separator and a method for manufacturing the same and a battery using the same. The battery separator is excellent in alkaline retaining property, initial alkaline absorption and durable alkaline absorption while maintaining tensile strength and air permeability, by forming functional groups or bonds of &mdash;CHO or &mdash;C,H&mdash;O,, &mdash;CO&mdash;, and &mdash;COO&mdash; or &mdash;COO,on the surface of the non-woven fabric. The battery shows great wettability with an alkaline electrolyte when incorporated into an battery, and thus, improves the battery life. The battery separator is provided by mixing and wet laid processing 15-75 weight % of splittable conjugated staple fibers comprising polyolefin polymer (component A) and ethylene vinyl alcohol copolymer (component B) arranged adjacent to each other when viewed in fiber cross section, 20-60 weight % of thermal bonding staple fibers, and 0-50 weight % of synthetic fibers that have greater fineness than that of ultra fine fibers formed by splitting the splittable bi-component fibers and have the same or smaller fineness than that of the thermal bonding fibers; treating the wet laid type non-woven fabric with high-pressure water flow to split the splittable bi-component fibers and to form the ultra fine fibers while entangling the fibers; treating both surfaces of the non-woven fabric with corona surface discharge, and calendering by heated rollers.

Battery separator and method for manufacturing the same and battery

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Hyogo, Japan

Tatsunori Kida