Nitto-denko Corporation

Hitachi Maxell, Limited

Toshihiko Shinomura

Shuuji Yano

Toshimitsu Tachibana

Masakatsu Urairi

Hiroyuki Higuchi

Hiroyuki Iida

Kiichiro Matsushita

Kazunori Kawamura

Kenji Matsumoto

Noboru Masutani

Minoru Ezoe

Osamu Ishida

Junichi Nakazono

An alkaline secondary battery comprising a negative comprising cadmium, zinc or iron or an oxide or thereof or a hydrogen absorbing alloy, a positive electrode comprising a metal oxide or a metal hydroxide, and a separator, which are all impregnated with an electrolyte comprising an alkaline aqueous solution is disclosed, wherein the separator is made of a polyolefin fiber sheet which has a wicking rate of pure water of at least 10 mm per 2 minutes when one end of the sheet is dipped in pure water at 20.degree. C. and 60% RH. Since the separator is chemically stable and exhibits sufficient hydrophilic properties, the battery retains a high electrode utilization even at a high rate discharging and has a practically sufficient cycle life.

Process for producing a wind-type alkaline secondary battery

A process for producing a polytetrafluoroethylene molded article by isostatic molding is disclosed, the isostatic molding being conducted under a high pressure of from 1,500 to 10,000 kg/cm.sup.2. The resulting molded article is isotropic as regards coefficient of thermal expansion and exhibits improved frictional resistance.

Process for producing polytetrafluoroethylene molded article

A porous film comprising a composition of 10 to 90% by weight of polypropylene and 10 to 90% by weight of polyethylene having an Mw/Mn ratio, as determined by high-temperature gel-permeation chromatography, of 10 or less is disclosed. The porous film has a high tensile modulus, a satisfactory appearance, and a uniform thickness. A battery separator comprising the porous film performs a shut-down function (an increase in resistance) in case of a temperature rise due to an abnormal current.

Porous film, process for producing the same, and use of the same

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Osaka, Japan

Toshihiko Shinomura