Toray Industries, Inc.

Toyo Boseki Kabushiki Kaisha

Toray Battery Separator Film Co., Ltd.

Naoki Mizuno

Masami Sugata

Koichi Matano

Michihiko Irie

Ken Shimizu

Masanori Nakamura

Mikio Matsuoka

Yoshitaka Ayuzawa

Katsuhiko Nose

Jun Inagaki

Chikao Morishige

Toshitake Suzuki

Shoichi Gyobu

Yoshimitsu Sakaguchi

Kotaro Kimishima

Yasuhiro Nishino

Tetsuo Kodama

Hidekazu Yoshida

Hideki Sugihara

Yusuke Shimizu

Syunji Kurahara

Mutsuo Nishi

Tomonori Yoshinaga

Kosuke Harumoto

Shigenori Iwade

Hisashi Ubara

Koichi Matsuda

Ken Takasugi

Shinichi Tsukada

Tadaaki Yoshinaka

A battery separator includes a polyolefin microporous membrane and a porous layer placed on at least one surface of the polyolefin microporous membrane. The polyolefin microporous membrane has a variation range of an F25 value in a longitudinal direction of 1 MPa or less. The F25 value indicates a value obtained by dividing a load value measured at 25% elongation of a specimen with use of a tensile tester by a cross-sectional area of the specimen. The porous layer contains a fluorine-based resin and an inorganic particle and has an average thickness T(ave) of 1 to 5 &#x3bc;m.

Polyolefin microporous membrane, battery separator and production method

A polyolefin microporous membrane has a variation range of F25 value in a longitudinal direction of 1 MPa or less; a thickness of 3 &#x3bc;m or more and less than 7 &#x3bc;m; and a length of 1,000 m or more (wherein the F25 value is a value obtained by measuring a load value applied to a test specimen when the test specimen is stretched by 25% using a tensile tester; and dividing the load value by a value of a cross-sectional area of a test specimen).

Microporous polyolefin membrane, separator for battery, and production processes therefor

A polyolefin microporous membrane is suitable to provide thereon a porous layer having little variation in thickness, which has a fluctuation range of F25 value in the length direction of 1 MPa or less, and which has a length of 1,000 m or more (wherein the F25 value refers to a value obtained by: measuring a load value applied to a test specimen when the test specimen is stretched by 25% using a tensile tester; and dividing the load value by the value of the cross-sectional area of the test specimen).

Microporous polyolefin film, separator for battery, and production processes therefor

A battery separator includes a polyolefin microporous membrane having a width of 100 mm or more, and a porous layer laminated on at least one surface of the polyolefin microporous membrane. The polyolefin microporous membrane has a variation range of an F25 value in a width direction of 1 MPa or less, and the F25 value indicates a value obtained by dividing a load value measured at 25% elongation of a specimen with use of a tensile tester by a cross-sectional area of the specimen. The porous layer contains a fluorine-based resin and an inorganic particle.

Battery separator and method of manufacturing same

A polyolefin microporous membrane is disclosed. The membrane has a width of not less than 100 mm, and a variation range of an F25 value in a width direction is not greater than 1 MPa. The F25 value is a value obtained by dividing a load at 25% elongation of a sample of the laminated polyolefin microporous membrane as measured with a tensile testing machine by a cross-sectional area of the sample.

A separator for batteries that achieves both adhesiveness to electrodes and low thermal shrinkage, which have been conventionally difficult to be compatible with each other, and has excellent ion permeability in order to further improve the safety of the separator, on the assumption that lithium ion secondary batteries are widely used for electric automobiles and the like, which require the batteries to withstand severe operating conditions. The separator for batteries is configured such that a modified porous layer containing a fluororesin and inorganic particles is laminated on at least one side of a porous membrane formed of a polyolefin resin. The content of the particles is equal to or more than 40% by volume and less than 70% volume with respect to the total of the fluororesin and the particles. The fluororesin has a crystallinity of equal to or more than 36% and less than 70%.

Separator for battery

A multi-layer polyolefin porous membrane is disclosed. The membrane includes first and second layers, and a plurality of protrusions including polyolefin. The protrusions have a protrusion width (W) satisfying 5 &#x3bc;m&#x2264;W&#x2264;50 &#x3bc;m and have a protrusion height (H) satisfying 0.5 &#x3bc;m&#x2264;H. The protrusions are randomly disposed on a first side of the membrane, and the protrusions are disposed with a density of not less than 3 protrusions/cmand not greater than 200 protrusions/cm. A meltdown temperature of the membrane is not lower than 165&#xb0; C., an air permeation resistance of the membrane is not greater than 300 sec/100 cc Air, and a thickness of the membrane is not greater than 20 &#x3bc;m.

Multi-layer polyolefin porous membrane, battery separator obtained using the same, and method for producing the same

A laminated polyolefin microporous membrane is disclosed. The laminated polyolefin microporous membrane includes a first polyolefin microporous membrane, and a second polyolefin microporous membrane. A shutdown temperature of the laminated polyolefin microporous membrane is from 128&#xb0; C. to 135&#xb0; C., an air permeation resistance increase rate from 30&#xb0; C. to 105&#xb0; C. per 20 &#x3bc;m of thickness of the laminated polyolefin microporous membrane is less than 1.5 sec/100 cc Air/&#xb0; C., and a variation range in an F25 value of the laminated polyolefin microporous membrane in a longitudinal direction is not greater than 1 MPa. The F25 value represents a value determined by dividing the load at 25% elongation of a sample of the laminated polyolefin microporous membrane as measured with a tensile tester by the cross-sectional area of the sample polyolefin microporous membrane.

Laminated polyolefin microporous membrane, battery separator, and production method thereof

A laminated porous membrane includes a polyolefin porous membrane, on one surface of which projections that are made of a polyolefin and satisfy 5 &#x3bc;m&#x2264;W&#x2264;50 &#x3bc;m (W: projection size) and 0.5 &#x3bc;m&#x2264;H (H: projection height) are irregularly scattered at a density of 3/cmto 200/cm, and a modifying porous layer laminated on the surface of the polyolefin porous membrane having the projections, wherein the modifying porous layer includes a binder with a tensile strength of at least 5 N/mmand inorganic particles.

Laminated porous membrane, process for manufacturing same and separator for battery

Considering that the battery separator of embodiments of the present invention will have thinner materials and lower costs, provided are a polyolefin porous membrane with exceptionally high peel strength between the polyolefin porous membrane and a modified porous layer, suitable for high-speed processing during slit processing and the battery assembly process, and suitable for laminating on a modified porous layer, and a battery separator obtained by laminating a modified porous layer on the polyolefin porous membrane. A polyolefin porous membrane comprising protrusions of polyolefin having a size (W) within a range of 5 &#x3bc;m&#x2264;W&#x2264;50 &#x3bc;m and a height (H) within a range of 0.5 &#x3bc;m&#x2264;H and irregularly disposed on both sides of the polyolefin porous membrane in a density not less than 3/cmand not more than 200/cmper side, and the polyolefin porous membrane having a thickness of not more than 25 &#x3bc;m.

Porous membrane, battery separator obtained using same, and method of producing same

A polyolefin porous membrane disclosed. The membrane includes a plurality of protrusions of polyolefin having a size (W) of 5 &#x3bc;m&#x2264;W&#x2264;50 &#x3bc;m and a height (H) of 0.5 &#x3bc;m&#x2264;H. The protrusions are disposed on one side of the polyolefin porous membrane with a density of at least 3/cmand at most 200/cm, and the polyolefin porous membrane has a thickness of at most 20 &#x3bc;m. A battery separator including the membrane is also disclosed.

Polyolefin porous membrane, battery separator obtained using same, and method of producing same

A battery separator is disclosed. The battery separator includes a polyolefin porous membrane which has a plurality of protrusions including a polyolefin. The protrusions are interspersed randomly on at least one surface of the polyolefin porous membrane at a density of not less than 3 protrusions/cm2 and not greater than 200 protrusions/cm2. The protrusions have a size W, where 5 &#x3bc;m&#x2264;W&#x2264;50 &#x3bc;m, and the protrusions have a height H, where 0.5 &#x3bc;m&#x2264;H. The battery separator also includes a modified porous layer, including a fluorine-based resin, and a plurality of inorganic particles laminated on the at least one surface of the polyolefin porous membrane. A concentration of the inorganic particles is not less than 40 wt. % and is less than 80 wt. %.

Battery separator and manufacturing method thereof

A battery separator includes a porous membrane A including a polyolefin resin, and a porous membrane B laminated thereon including a fluororesin and inorganic particles or cross-linked polymer particles,

Battery separator, and method for producing same

Considering that battery separators will require further thinner materials and lower costs in the future, a battery separator of the present invention, in which multi-layer polyolefin porous membrane with exceptionally high peel strength against a modified porous layer, suitable for high-speed processing during slit process and battery assembly process, and suitable for laminating on a multi-layer modified porous layer, and a multi-layer modified porous layer are laminated, is provided. A multi-layer polyolefin porous membrane comprising at least two or more layers, the multi-layer polyolefin porous membrane having a shut-down temperature in a range of 128 to 135&#xb0; C., a rate of increase in air permeation resistance from 30&#xb0; C. to 105&#xb0; C. scaled to 20 &#x3bc;m thickness less than 1.5 sec/100 cc Air/&#xb0; C., and a thickness not more than 20 &#x3bc;m.

Multi-layer polyolefin porous membrane, battery separator using same, and process for producing multi-layer polyolefin porous membrane

A method produces a composite porous membrane including a porous membrane A formed of a polyolefin-based resin; and a porous membrane B containing a heat-resistant resin and laminated on the porous membrane A, including: (i) applying a heat-resistant resin solution onto a base film, followed by passing the coated film through a low-humidity zone, and then through a high-humidity zone to form a heat-resistant resin membrane on the base film; and (ii) bonding together the heat-resistant resin membrane formed in step (i) and a porous membrane A formed of a polyolefin-based resin, followed by converting the heat-resistant resin membrane into a porous membrane B by immersion in a solidification bath, and washing and drying the same to obtain the composite porous membrane.

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Nasushiobara, Japan

Naoki Mizuno