US 12,012,507 B2
Thermoplastic elastomer composition and automobile weather strip
Shouhei Sasama, Minato-ku (JP); Yuki Sato, Minato-ku (JP); and Osamu Kose, Minato-ku (JP)
Assigned to ENEOS Materials Corporation, Tokyo (JP)
Filed by ENEOS Materials Corporation, Tokyo (JP)
Filed on Aug. 23, 2022, as Appl. No. 17/821,547.
Claims priority of application No. 2021-137842 (JP), filed on Aug. 26, 2021.
Prior Publication US 2023/0070658 A1, Mar. 9, 2023
Int. Cl. C08L 23/16 (2006.01)
CPC C08L 23/16 (2013.01) [C08L 2205/025 (2013.01); C08L 2205/03 (2013.01); C08L 2207/04 (2013.01); C08L 2207/322 (2013.01); C08L 2312/00 (2013.01)] 5 Claims
 
1. A thermoplastic elastomer composition obtained by melt-kneading an ethylene/α-olefin/non-conjugated polyene copolymer rubber (A) that is a copolymer of ethylene, an α-olefin having 3 to 20 carbon atoms, and a non-conjugated polyene, a polyolefin resin (B), and a mineral oil-based softening agent (C) in the presence of an organic peroxide (D) and a crosslinking aid (E),
wherein, when a total exothermic energy amount of a peak observed when the polyolefin resin (B) is subjected to differential scanning calorimetry by decreasing a temperature from 200° C. to −80° C. at −10° C./min in conformity with ISO 11357-3:2018 is defined as 100%, a temperature at which the observed peak reaches 95% by being integrated from a high-temperature side is from 75° C. to 95° C.,
wherein a mass ratio (C)/(A) between the mineral oil-based softening agent (C) and the ethylene/α-olefin/non-conjugated polyene copolymer rubber (A) falls within a range of from 0.8 to 1.9,
the thermoplastic elastomer composition having a shear viscosity of from 5 Pas to 20 Pa·s at 140° C. and 10,000 s−1.