CN-117098803-B - Thermoplastic elastomer composition and use thereof

Abstract

The purpose of the present invention is to provide a thermoplastic elastomer composition which has low hardness, is soft, and has excellent scratch resistance. The present invention relates to a thermoplastic elastomer composition comprising the following components (A) to (D). 100 parts by mass of (A) a propylene polymer, (B) 50 to 300 parts by mass of an ethylene-alpha-olefin copolymer comprising ethylene and an alpha-olefin unit having 3 to 20 carbon atoms, (C) 50 to 280 parts by mass of a softener, and (D) 90 to 400 parts by mass of a hydrogenated product of a block copolymer having at least one block mainly composed of conjugated diene monomer units and at least one block mainly composed of vinyl aromatic monomer units, respectively.

Inventors

• ZHONG SHILIANG
• JTHEUKATA MASAKAZU
• YAMAMOTO KOJI
• SASAKI YASUO

Assignees

• 三井化学株式会社

Dates

Publication Date

20260512

Application Date

20220127

Priority Date

20210331

Claims (10)

1. 1. A thermoplastic elastomer composition comprising the following (A) to (D), (A) 100 parts by mass of a propylene-based polymer, (B) An ethylene-alpha-olefin copolymer comprising units derived from ethylene and units derived from an alpha-olefin having 3 to 20 carbon atoms, wherein the content of the units derived from ethylene is in the range of 122 to 200 parts by mass, wherein the total amount of the units derived from ethylene and the units derived from an alpha-olefin having 3 to 20 carbon atoms is 100 mol%, (C) 50-280 parts by mass of a softener, (D) The hydrogenated product of the block copolymer having at least one block mainly composed of conjugated diene monomer units and at least one block mainly composed of vinyl aromatic monomer units is in the range of 90 to 400 parts by mass.
2. 2. The thermoplastic elastomer composition according to claim 1, comprising (E) a polyorganosiloxane in an amount of 2 to 30 parts by mass.
3. 3. Thermoplastic elastomer composition according to claim 1 or 2, the mass ratio of (C) to (B), i.e. (C)/(B), exceeds 0 and is less than 3.
4. 4. The thermoplastic elastomer composition according to claim 1 or 2, wherein the mass ratio of (C) to (B), i.e., (C)/(B), is 0.6 to 1.86.
5. 5. The thermoplastic elastomer composition according to claim 1 or 2, wherein the block of (D) having conjugated diene monomer units as a main body is a copolymer block containing conjugated diene monomer units as a main body and vinyl aromatic monomer units.
6. 6. The thermoplastic elastomer composition according to claim 1 or 2, which is subjected to dynamic heat treatment.
7. 7. The thermoplastic elastomer composition according to claim 6, having a melt flow rate of 0.1 to 30g/10 minutes at 230 ℃ under a load of 1.2 kg.
8. 8. The thermoplastic elastomer composition according to claim 1 or 2, which is crosslinked by at least a part of the (B).
9. 9. An injection molded article comprising the thermoplastic elastomer composition according to any one of claims 1 to 8.
10. 10. An automotive interior part comprising the injection-molded body according to claim 9.

Description

Thermoplastic elastomer composition and use thereof Technical Field The present invention relates to thermoplastic elastomer compositions and uses thereof. Background For interior skin materials such as automobile instrument panels and door trim panels, olefinic thermoplastic elastomers are sometimes used from the standpoint of weight reduction of the materials. When a sheet for an interior skin material formed of an olefin-based thermoplastic elastomer is molded into a shape such as an instrument panel or a door trim, vacuum molding or injection molding is generally performed. As an olefin-based thermoplastic elastomer for injection molding, for example, a composition containing a polypropylene-based resin, an olefin-based copolymer rubber, and a hydride of a block copolymer having a vinyl aromatic monomer unit and a softener in a predetermined ratio is proposed in international publication No. 2010/067564 (patent document 1), and a thermoplastic elastomer composition containing a polypropylene-based resin, a softener, and a polyorganosiloxane in a predetermined ratio is proposed in international publication No. 2011/155571 (patent document 2). Prior art literature Patent literature Patent document 1 International publication No. 2010/067564 pamphlet Patent document 2 International publication No. 2011/155571 pamphlet Disclosure of Invention Problems to be solved by the invention In recent years, there has been a demand for a material which has lower hardness and softness than conventional thermoplastic elastomer compositions from the viewpoint of improving the touch while maintaining excellent scratch resistance. However, the thermoplastic elastomer compositions described in patent documents 1 and 2 are designed to have excellent scratch resistance at the previously allowable hardness, but in recent years, the scratch resistance in the low hardness range required is insufficient, and further improvement is desired. The purpose of the present invention is to provide a thermoplastic elastomer composition which has low hardness, is soft, and has excellent scratch resistance. Means for solving the problems The present invention relates to a thermoplastic elastomer composition comprising the following components (A) to (D). (A) 100 parts by mass of a propylene-based polymer, (B) An ethylene-alpha-olefin copolymer comprising ethylene and an alpha-olefin unit having 3 to 20 carbon atoms in an amount of 50 to 300 parts by mass, (C) 50-280 parts by mass of a softener, (D) The hydrogenated product of the block copolymer having at least one block mainly composed of conjugated diene monomer units and at least one block mainly composed of vinyl aromatic monomer units is in the range of 90 to 400 parts by mass. ADVANTAGEOUS EFFECTS OF INVENTION The thermoplastic elastomer composition of the present invention is low in hardness, soft and excellent in scratch resistance, and is suitable for various known applications such as automobile parts, civil engineering and construction materials, electric and electronic parts, sanitary articles, films and sheets, foam, and artificial leather, and in particular, can be suitably used for automobile parts such as automobile interior parts, and skin materials such as artificial leather. Detailed Description In the present specification, the numerical range indicated by "to" means a range including numerical values described before and after "to" as a lower limit value and an upper limit value. < Propylene Polymer (A) >) The propylene polymer (a) [ hereinafter, sometimes referred to as "component (a)", which is one of the components of the thermoplastic elastomer composition of the present invention. The term "polymer" means a polymer having a content of structural units derived from propylene of 50 mol% or more in structural units constituting the polymer, and the content of structural units derived from propylene in the component (a) is preferably 90 mol% or more. The component (A) of the present invention may be 1 or 2 or more. The component (a) according to the present invention may be a propylene homopolymer or a copolymer of propylene and a comonomer other than propylene. The structure of the component (a) according to the present invention is not particularly limited, and for example, the propylene-derived structural unit may be isotactic, syndiotactic or atactic, and is preferably isotactic. In the case of the copolymer, it may be any of a random type (also referred to as random PP), a block type (block PP: also referred to as bPP) and a graft type. The comonomer may be any other monomer copolymerizable with propylene, and is preferably an α -olefin having 2 or 4 to 10 carbon atoms. Specifically, ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene and the like are mentioned, and among these, ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene and 1-octene are preferable. The comonomer may be used in an amount