US 11,746,221 B2
Thermoplastic elastomer composition
Masato Kobayashi, Minato-ku (JP); Ryoji Usui, 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 Jul. 15, 2022, as Appl. No. 17/865,562.
Claims priority of application No. 2021-117716 (JP), filed on Jul. 16, 2021; and application No. 2021-198222 (JP), filed on Dec. 7, 2021.
Prior Publication US 2023/0041123 A1, Feb. 9, 2023
Int. Cl. C08L 23/16 (2006.01); C08L 23/08 (2006.01); C08L 9/00 (2006.01)
CPC C08L 23/0815 (2013.01) [C08L 9/00 (2013.01); C08L 2207/04 (2013.01)] 5 Claims
 
1. A thermoplastic elastomer composition obtained by melt-kneading (A) an ethylene/α-olefin/non-conjugated polyene copolymer rubber that is a copolymer of ethylene, an α-olefin having 3 to 20 carbon atoms and a non-conjugated polyene, (B) a polyolefin resin and (C) a mineral oil-based softening agent in a presence of (D) a crosslinking agent,
at least part of the ethylene/α-olefin/non-conjugated polyene copolymer rubber (A) being crosslinked,
the thermoplastic elastomer composition having a sea-island structure in which the ethylene/α-olefin/non-conjugated polyene copolymer rubber (A) is dispersed as a dispersed phase (island phase) in a continuous phase (sea phase) of the polyolefin resin (B), and
when a cross-section of the thermoplastic elastomer composition is observed with an atomic force microscope (AFM), a ratio of (b) a local elastic modulus of the continuous phase to (a) a local elastic modulus of the dispersed phase being from 10 to 30.