# US 11,993,702 B2 · Thermoplastic resin composition having high rigidity and low coefficient of linear thermal expansion and molded article comprising same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,993,702 B2 - Document ID: US11993702B2 - Status: Granted - Kind: B2 - Application number: 17/858,378 - Filed: 2022-07-06 - Published: 2023-01-19 - Granted: 2024-05-28 - Earliest claimed: 2021-07-06 - Assignees: Hyundai Motor Company; Kia Corporation; Lotte Chemical Corporation - Applicants: Hyundai Motor Company; Kia Corporation; Lotte Chemical Corporation - Inventors: Jin Young Yoon; Hee Joon Lee; Dong Eun Cha; Sun Jun Kwon; Chun Ho Park; Seung Ryong Jeong; Kyung Hwan Lim; Eun Hwa Jang - Web page: https://patentgrep.com/patent/US11993702B2 ## CPC - C08L 23/142: {at least partially crystalline copolymers of propene with other olefins} - C08L 23/16: Ethylene-propylene or ethylene-propylene-diene copolymers - C08L 2205/025: containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure - C08L 2205/03: containing three or more polymers in a blend - C08L 2205/06: having improved processability or containing aids for moulding methods - C08L 2205/24: Crystallisation aids - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) ## Abstract The present disclosure provides a thermoplastic resin composition having high rigidity and a low coefficient of linear thermal expansion and a molded article including the same. Specifically, the thermoplastic resin composition includes a base resin including at least two polypropylene-based resins having different melt indexes, an elastomer having a melt index (190° C., 2.16 kg) of 20 g/10 min to 35 g/10 min as measured by ASTM D1238, and inorganic particles, and 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. ## Claims ### Claim 1 A thermoplastic resin composition comprising: a base resin comprising a first polypropylene-based resin having a melt index (230° C., 2.16 kg) of 90 g/10 min to 110 g/10 min as measured by ASTM D1238, and a second polypropylene-based resin having a melt index (230° C., 2.16 kg) of 50 g/10 min to 70 g/10 min as measured by ASTM D1238; an elastomer having a melt index (190° C., 2.16 kg) of 20 g/10 min to 35 g/10 min as measured by ASTM D1238; and inorganic particles. ### Claim 2 (depends on 1) The thermoplastic resin composition of claim 1, wherein each of the first polypropylene-based resin and the second polypropylene-based resin comprises at least one selected from the group consisting of: homo-polypropylene, a copolymer of propylene and α-olefin having 2 and 4 to 20 carbon atoms, and combinations thereof. ### Claim 3 (depends on 1) The thermoplastic resin composition of claim 1, wherein the base resin comprises the first polypropylene-based resin and the second polypropylene-based resin at a weight ratio of 1:0.2 to 1:0.6. ### Claim 4 (depends on 1) The thermoplastic resin composition of claim 1, wherein the elastomer comprises a copolymer of ethylene and α-olefin having 3 to 8 carbon atoms. ### Claim 5 (depends on 1) The thermoplastic resin composition of claim 1, wherein the inorganic particles comprise at least one selected from the group consisting of: talc, mica, calcium carbonate, wollastonite, clay, magnesium sulfate, whiskers, and combinations thereof. ### Claim 6 (depends on 1) The thermoplastic resin composition of claim 1, wherein the inorganic particles have an average diameter of 1 μm to 3 μm. ### Claim 7 (depends on 1) The thermoplastic resin composition of claim 1, comprising: 50 wt % to 60 wt % of the base resin; 15 wt % to 30 wt % of the elastomer; and 20 wt % to 35 wt % of the inorganic particles. ### Claim 8 (depends on 1) The thermoplastic resin composition of claim 1, further comprising at least one nucleating agent selected from the group consisting of: a cyclohexane dicarboxylic acid metal salt, metal stearate, and combinations thereof. ### Claim 9 (depends on 1) The thermoplastic resin composition of claim 1, further comprising at least one additive selected from the group consisting of: an antioxidant, an ultraviolet absorber, a nucleating agent, a coupling agent, a dispersant, a light stabilizer, a processing lubricant, a slipping agent, an antistatic agent, an inorganic pigment, and combinations thereof. ### Claim 10 (depends on 1) A molded article comprising the thermoplastic resin composition of claim 1. ### Claim 11 (depends on 10) The molded article of claim 10, wherein IZOD impact strength measured at 23° C. according to ASTM D256 is 320 J/m or more and IZOD impact strength measured at −30° C. is 45 J/m or more. ### Claim 12 (depends on 10) The molded article of claim 10, wherein tensile strength measured according to ASTM D638 is 17 MPa or more. ### Claim 13 (depends on 10) The molded article of claim 10, wherein the molded article is at least one automobile exterior material selected from the group consisting of: a side sill molding, door molding, fender molding, quarter glass molding, roof rack, side outer garnish, roof molding garnish, back panel molding, tailgate garnish, and combinations thereof.