US 11,718,740 B2
Method for producing thermoplastic elastomer composition
Shinichiro Shimomura, Chiba (JP)
Assigned to SUMITOMO CHEMICAL COMPANY, LIMITED, Tokyo (JP)
Filed by SUMITOMO CHEMICAL COMPANY, LIMITED, Tokyo (JP)
Filed on Aug. 24, 2022, as Appl. No. 17/894,776.
Claims priority of application No. 2021-137840 (JP), filed on Aug. 26, 2021.
Prior Publication US 2023/0071344 A1, Mar. 9, 2023
Int. Cl. C08L 23/16 (2006.01); C08J 3/00 (2006.01); C08L 53/00 (2006.01)
CPC C08L 23/16 (2013.01) [C08J 3/005 (2013.01); C08L 53/00 (2013.01); C08J 2323/16 (2013.01); C08J 2353/00 (2013.01); C08J 2423/08 (2013.01); C08J 2423/12 (2013.01); C08J 2423/16 (2013.01); C08J 2491/00 (2013.01); C08L 2203/30 (2013.01); C08L 2205/025 (2013.01); C08L 2205/035 (2013.01); C08L 2207/04 (2013.01); C08L 2207/322 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method for producing a thermoplastic elastomer composition, wherein the produced thermoplastic elastomer composition contains 5 mass % or less of a mineral oil (C), the method comprising:
a first step of melt-kneading polypropylene (A-1) and an ethylene-based copolymer rubber (B) in the presence of an organic peroxide, the polypropylene (A-1) being polypropylene of which 20° C. xylene insoluble fraction has an intrinsic viscosity [ηcxis] of 0.1 dl/g or more and less than 1.5 dl/g; and
a second step of further adding polypropylene (A-2) of which 20° C. xylene insoluble fraction has an intrinsic viscosity [ηcxis] of 1.5 dl/g or more and 7 dl/g or less, and
melt-kneading the resulting mixture.