US 12,291,806 B2
Non-woven fabric and separator for electrochemical elements
Akihiko Kawano, Toyko (JP); and Masanao Tanaka, Tokyo (JP)
Assigned to JAPAN VILENE COMPANY, LTD., Tokyo (JP)
Appl. No. 17/288,381
Filed by JAPAN VILENE COMPANY, LTD., Tokyo (JP)
PCT Filed Nov. 5, 2019, PCT No. PCT/JP2019/043276
§ 371(c)(1), (2) Date Apr. 23, 2021,
PCT Pub. No. WO2020/100654, PCT Pub. Date May 22, 2020.
Claims priority of application No. 2018-213234 (JP), filed on Nov. 13, 2018.
Prior Publication US 2021/0381143 A1, Dec. 9, 2021
Int. Cl. D04H 1/4382 (2012.01); D01D 1/02 (2006.01); D01D 5/06 (2006.01); D01F 6/06 (2006.01); D01F 8/06 (2006.01); H01M 50/417 (2021.01); H01M 50/443 (2021.01); H01M 50/489 (2021.01); H01M 50/491 (2021.01); H01M 50/494 (2021.01)
CPC D04H 1/43828 (2020.05) [D01D 1/02 (2013.01); D01D 5/06 (2013.01); D01F 6/06 (2013.01); D01F 8/06 (2013.01); H01M 50/417 (2021.01); H01M 50/443 (2021.01); H01M 50/489 (2021.01); H01M 50/491 (2021.01); H01M 50/494 (2021.01); D10B 2321/0211 (2013.01); D10B 2321/022 (2013.01)] 14 Claims
 
1. A nonwoven fabric in which the fabric fibers consist of polyolefin-based composite fusion fibers provided with a fusion component on the fiber surface, and polypropylene ultrafine fibers having the average fiber diameter of 2 μm or less, and the value (σ/d) obtained by dividing a standard deviation value (σ) of a fiber diameter distribution of the ultrafine fibers by the average fiber diameter (d) of the ultrafine fibers is 0.2 or less;
wherein the composite fusion fibers are fused,
the average fiber diameter of the polyolefin-based composite fusion fibers is 3 μm to 7.4 μm,
the content of the polyolefin-based composite fusion fibers is 60 mass % or more in the nonwoven fabric,
the content of the polypropylene ultrafine fibers is 20 mass % or more in the nonwoven fabric,
the basis of the nonwoven fabric is 40 g/m2 or less,
the sum of the tensile strength by zero-span per basis weight in the longitudinal direction and the lateral direction is 6.5N/50 mm or more,
the Young's modulus of the polyolefin-based composite fusion fiber is 60 cN/dtex or more,
the ratio of the machine direction tensile strength (MD) of the nonwoven fabric to the cross-machine direction tensile strength (CD) of the nonwoven fabric is 2.0 to 5.3,
the needle type penetration resistance per basis weight and per average fiber diameter of the nonwoven fabric is 6.3 gram-force or more, and
the nonwoven fabric optionally comprises inorganic particles.