US 11,905,402 B2
Polyolefin resin composition having high rigidity and low coefficient of linear thermal expansion and weight-reduced automobile part comprising same
Jin Young Yoon, Gimpo-si (KR); Hee Joon Lee, Seoul (KR); Dong Eun Cha, Hwaseong-si (KR); Sun Jun Kwon, Seoul (KR); Chun Ho Park, Seoul (KR); Seung Ryong Jeong, Seoul (KR); Jeong Gil Ko, Yongin-si (KR); and Yoon Hwan Lee, Seoul (KR)
Assigned to HYUNDAI MOTOR COMPANY, Seoul (KR); KIA CORPORATION, Seoul (KR); and HANWHA TOTAL ENERGIES PETROCHEMICAL CO., LTD., Seosan-si (KR)
Filed by Hyundai Motor Company, Seoul (KR); Kia Corporation, Seoul (KR); and Hanwha Total Energies Petrochemical Co., Ltd., Seosan-si (KR)
Filed on Jul. 6, 2022, as Appl. No. 17/810,994.
Claims priority of application No. 10-2021-0088630 (KR), filed on Jul. 6, 2021.
Prior Publication US 2023/0020477 A1, Jan. 19, 2023
Int. Cl. C08L 23/16 (2006.01); C08L 23/12 (2006.01)
CPC C08L 23/16 (2013.01) [C08L 23/12 (2013.01); C08L 2205/08 (2013.01); C08L 2207/04 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A thermoplastic resin composition having a low coefficient of linear thermal expansion, comprising:
a polypropylene-based resin having an isotactic pentad fraction of 96% or more as measured by 13C-NMR;
a thermoplastic elastomer comprising at least two elastomers;
an inorganic filler having an average particle diameter of 0.1 μm to 5 μm; and
a compatibilizer,
wherein the thermoplastic resin composition has a flexural modulus (FM) of 2,500 MPa or more and a coefficient of linear thermal expansion (CLTE) of 60 μm/m·° C. or less,
wherein the flexural modulus is measured according to ASTM D790 from a molded article of the size of 127×12.7×6.4 mm, a span length of 100 mm and a speed of 10 mm/min,
wherein the coefficient of linear thermal expansion is measured according to ASTM E831 from a molded article of the size of 10×12.8×3.2 mm, at a rate of 5° C./min and in the range of −30° C. to 30° C., and
wherein the thermoplastic resin composition having a melt index (230° C., 2.16 kgf) of 35 g/10 min to 50 g/10 min.