Toyo Boseki Kabushiki Kaisha

Toshio Tanaka

Masahiro Yamashita

Hiroki Yamaguchi

Naohiko Takimoto

Satoshi Maeda

Koji Tanaka

Yozo Yamada

Yasunari Hotta

Shiro Hamamoto

Hiroshi Ono

Shinichiro Mori

Yasuhiro Iizuka

Yasushi Tsuzuki

An object of the present invention is to provide a thin battery separator having an excellent nitrate group trapping performance and a high piercing strength. The inventive separator for a secondary battery, which can accomplish such an object, is made of a resin composition mainly containing a polyolefin having a hydrophilic functional group, wherein the resin composition has a content (ratio to a total resin amount) of a low-density polyethylene of 20 mass % or less, a piercing strength of 5 to 100 N, a Metsuke of 20 to 75 g/m, a thickness of 15 to 150 &#x3bc;m, and an unneutralized hydrophilic functional group amount of 1&#xd7;10to 5&#xd7;10mol/m.

Separator for secondary battery and method for producing the same

A battery including a separator having a satisfactory ammonia trapping property is speculated to exhibit a less self-discharge and a higher capacity-holding rate. The ammonia trapping property is speculated to be increased with an increasing degree of sulfonation of a constitutive polyolefin fiber. However, a highly sulfonated conventional polyolefin has a deteriorated fiber strength and highly sulfonated portions thereof are peeled or eliminated, and the resulting fiber cannot have a significantly high degree of sulfonation. The invention is therefore intended to provide a separator having an improved ammonia trapping property. The invented separator includes a polyolefin resin fiber having large amounts of introduced sulfonic groups. Specifically, the separator is one containing a fiber obtained by sulfonating a polyolefin resin fiber having an intrinsic viscosity number of 0.2 to 1.0 dl/g, one including a fiber obtained by sulfonating a polyolefin resin fiber and having a BET specific surface area of 0.5 m /g or more, or one including a fiber obtained by oxidizing a polyolefin fiber and sulfonating the oxidized fiber.

Battery separator, process for producing the same, and alkaline battery

Spherical resin particles having a sharp particle size distribution and a method for producing such particles are disclosed. Resin particles according to this invention contain at least a polyester polymer and a polymer formed from a polymerizable monomer, and have an average diameter (D) of 1 to 500 .mu.m. At least 70% by weight of the particles have a diameter in the range of 0.5 D to 2.0 D. Such resin particles can be produced by swelling polyester-containing seed particles with a polymerizable monomer and then polymerizing the polymerizable monomer in swelled seed particles.

Polymer particles and process for producing the same

Polymer particles and method for producing the same

A material is provided for a polarizable electrode. The material comprises a porous carbon material of activated carbon, activated carbon fibers, carbon fibers or powdery carbon as a raw material, wherein the total amount of acid groups of said porous carbon materials is 0.45 to 4.0 .mu.eq/m.sup.2 based on the BET surface area of said carbon material. The material is produced by subjecting the porous carbon raw material to dry oxidation treatment in an oxygen atmosphere whereby the total amount of acid groups introduced into said porous carbon material is 0.45 to 4.0 .mu.eq/m.sup.2 based on the BET surface area of said material.

Material for polarizable electrode

Growing community of inventors

Otsu, Japan

Toshio Tanaka