Asahi Kasei Chemicals Corporation

Asahi Kasei E-Materials Corporation

Asahi Kasei Kabushiki Kaisha

Takashi Ikemoto

Hiroshi Hatayama

Yoshihiro Imamura

Noboru Kubota

Hiroshi Sogo

Shinya Kawasoe

Masayuki Adachi

Takeshi Onizawa

There is provided a polyolefin microporous film which is excellent in taking-up stability in a production line and a processing line of the polyolefin microporous film, and further in a line for a battery taking-up step, and hardly generates step deviation when a roll thereof has received an impact. The polyolefin microporous film has a compression elastic modulus of 0.1 to 1,000 kPa, and a ratio of a tensile elastic modulus in the longitudinal direction to a tensile elastic modulus in the transverse direction of 1.5 to 7.8.

Polyolefin microporous film

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.

Separator for lithium ion secondary battery and method for manufacturing the same

The present invention provides a microporous polyolefin membrane having a porosity of 45% to 85% wherein the microporous polyolefin membrane easily absorbs the strain produced when the membrane undergoes compression, and retains excellent permeability and excellent electrical insulation performance even after compression by setting the maximum pore diameter at 0.1 &#x3bc;m to 0.23 &#x3bc;m, the MD elastic modulus at 400 to 2,000 MPa, and the ratio MD elastic modulus/TD elastic modulus at 1.5 to 9.

Microporous polyolefin membrane

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 &#x3bc;m and not larger than 1 &#x3bc;m.

Method for purifying suspended water by membrane filtration

The invention relates to a microporous membrane, which is provided with high safety even under a condition that the interior temperature of a battery becomes high, and which has high permeability and high mechanical strength at the same time. The polyolefin microporous membrane is characterized by a membrane thickness of 5 to 50 &#x3bc;m, a void content of 30 to 60%, a gas transmission rate of 40 to 300 sec/100 cc/20 &#x3bc;m, a piercing strength of not less than 2.5 N/20 &#x3bc;m and a break through temperature of not lower than 110&#xb0; C. The separator in accordance with the present invention is used to exhibit high safety under a high temperature condition as well as high permeability, and therefore it is particularly useful as a separator for miniaturized high capacity batteries of a non-aqueous electrolytic solution type.

Growing community of inventors

Tokyo, Japan

Takashi Ikemoto