WO2002051929A1

WO2002051929A1 - Thermoplastic elastomer composition

Info

Publication number: WO2002051929A1
Application number: PCT/JP2001/011055
Authority: WO
Inventors: Eiji Nakaishi; Hiroshi Ooyama
Original assignee: Sumitomo Chemical Company, Limited
Priority date: 2000-12-25
Filing date: 2001-12-17
Publication date: 2002-07-04

Abstract

A thermoplastic elastomer composition characterized by comprising the following ingredients (A) to (E), the amounts of the ingredients (B), (C), (D), and (E) being 0.05 to 0.7 parts by weight, 0.01 to 0.5 parts by weight, 0.01 to 0.5 parts by weight, and 0.01 to 5 parts by weight, respectively, per 100 parts by weight of the ingredient (A): (A) a thermoplastic olefin elastomer (A1) and/or a thermoplastic styrene elastomer (A2); (B) an antioxidant; (C) a light stabilizer; (D) a lubricant; and (E) a metal chloride and/or a metal aluminate.

Description

Thermoplastic elastomer compositions Technical field

The present invention relates to a thermoplastic elastomer composition. More specifically, the present invention relates to an olefin-based thermoplastic elastomer composition and / or a styrene-based thermoplastic elastomer composition having good heat resistance, light resistance and scratch resistance, and having excellent fogging resistance. Things. Background art

In recent years, an olefin-based thermoplastic elastomer composition and / or a styrene-based thermoplastic elastomer have been widely used for automotive interior parts such as instrument panels and airbag covers. Here, the olefin thermoplastic elastomer composition and the styrene or thermoplastic elastomer composition used for automobile interior parts are required to be excellent in general properties such as heat resistance, light resistance, and scratch resistance. Antioxidants, light stabilizers, and lubricants are added to improve these properties. However, for this reason, the additive contained in the composition volatilizes and adheres to the window glass, causing a phenomenon that causes inconvenience such as deterioration of visibility, that is, fogging occurs. Therefore, from the viewpoint of maintaining heat resistance, light resistance, scratch resistance, etc. at a satisfactory high level, and also having excellent fogging resistance, the conventional thermoplastic elastomer composition and Z or Styrenic thermoplastic elastomer compositions have not been fully satisfactory. Disclosure of the invention

An object of the present invention is to maintain a heat resistance, light resistance, scratch resistance, etc. at a satisfactory level, and to provide an olefin-based thermoplastic elastomer composition and a Z or styrene-based thermoplastic elastomer composition excellent in fogging resistance. The point is to provide. That is, the present invention contains the following components (A) to (E), and the content of the component (B) is 0.05 to 0.7 part by weight per 100 parts by weight of the content of the component (A). The content of the component (C) is 0.01 to 0.5 part by weight, the content of the component (D) is 0.01 to 0.5 part by weight, and the content of the component (E) is The amount is from 0.01 to 5 parts by weight according to the thermoplastic elastomer composition.

(A): (A1) olefin-based thermoplastic elastomer, (A2) styrene-based thermoplastic elastomer or a mixture thereof

(B) Antioxidant

(C) Lightfastener

(D) Lubricant

(E) Metal chloride and / or aluminate Brief description of drawings

FIG. 1 is a schematic cross-sectional view of an apparatus used for a fogging test of an example. BEST MODE FOR CARRYING OUT THE INVENTION

The component (A) of the present invention is a thermoplastic thermoplastic elastomer (A1), a styrene thermoplastic elastomer (A2), or a mixture thereof.

As the thermoplastic thermoplastic elastomer (A1), a compound TPO ("TPO" means a thermoplastic thermoplastic elastomer), a reactor, or a mixture thereof may be used. The reactor 1 is also referred to as a polymerization reactor 1 and is an olefin thermoplastic elastomer obtained by dispersing a rubber component as a soft part in a matrix resin as a hard part during polymerization.

Among the thermoplastic thermoplastic elastomers (A1), those containing 10 to 65% by weight of a polypropylene resin (a) and 90 to 35% by weight of an olefin rubber (b) are those having moldability and flexibility. It is preferable from the viewpoint of mechanical strength. However, the total amount of (a) and (b) shall be 100% by weight. The polypropylene resin (a) is a crystalline polymer containing a repeating unit derived from propylene. Among the polypropylene resins (a), propylene homopolymer (a1), propylene-ethylene random copolymer (a2), and propylene-ethylene block copolymer (a3) are considered from the viewpoint of availability. Preferably, these may be used alone or in combination of two or more. Here, (a 3) is composed of a first segment and a second segment, and the first segment is a propylene homopolymer portion or a propylene / ethylene random copolymer portion having a different ethylene content from the second segment. The second segment is a block copolymer which is a propylene-ethylene random copolymer part.

Melt flow rate (hereinafter referred to as MFR) of polypropylene resin (a) (JISK-7210, load 21.18N, temperature 230 ° C) indicates moldability and mechanical strength. From the viewpoint of further increasing the value, it is preferably from 0.1 to 150 gZl0 minutes, and more preferably from 0.5 to 100 gZl0 minutes. The higher the MFR, the better the moldability, while the lower the MFR, the better the mechanical strength. The polypropylene-based resin (a) can be produced by using either a polymerization catalyst such as a catalyst based on a Tiedlar catalyst or a catalyst based on a meta-aqueous catalyst.

The olefin rubber (b) is an amorphous polymer in which two or more types of olefin monomers are randomly copolymerized. Among the olefin rubbers (b), ethylene-α-olefin copolymer rubber (bl) and ethylene-α-yearly olefin-non-conjugated gen copolymer rubber (b 2) are considered from the viewpoint of availability. Preferably, these may be used alone or in combination of two or more.

Ethylene-α-olefin copolymer rubber (bl) is a copolymer rubber obtained by randomly polymerizing ethylene and α-olefin having 3 or more carbon atoms. As an α-olefin, from the viewpoint of availability, it is preferable to use a olefin having 3 to 8 carbon atoms, and more preferably, propylene, 1-butene, 1-hexene and 1-octene. is there. The content of the repeating unit (a-olefin unit) derived from a-olefin in (b 1) is preferably from 10 to 60% by weight from the viewpoint of further increasing mechanical strength and flexibility. a—Higher refine unit content is more flexible On the other hand, the lower the content of the refine unit, the better the mechanical strength.

The ethylene-α-olefin-non-conjugated gen copolymer rubber (b 2) is a copolymer rubber in which ethylene, α-olefin having 3 or more carbon atoms and non-conjugated gen are randomly polymerized. As the α-olefin, α-olefin having 3 to 8 carbon atoms is preferable, and propylene is more preferable, from the viewpoint of availability.

The content of α-refin units in (b 2) is preferably from 10 to 60% by weight from the viewpoint of further increasing mechanical strength and flexibility. << The greater the content of the 才 -refin units, the better the flexibility, while the lower the content of the —-refin units, the better the mechanical strength. As the non-conjugated gen, a non-conjugated gen having 4 to 30 carbon atoms is preferable from the viewpoint of availability. —Hexadiene, 6-methyl —1, 5-Hetadiene, 7-Methyl-1,6—Chain unconjugated diene such as 1,6-cyclohexene, cyclohexadiene, dicyclopentene, methyltetrahydride indene, 5 Cyclic non-co-gens such as —biernorpolene, 5-ethylidene-2-norporene, 5-methylene-12-norbornene, 5-isopropylidene-12-norbornene, 6-chloromethyl-5-isopropylenyl-2-norporene, 2,3-diisopropylidene-5-norpolenene, 2-ethylidene — 3-isopropylidene-5-norbornene, 2 _propenyl-1, 2, 2 _norpolnadiene 1, 3, 7-O click evening Toryen, 1, 4, 9 yo Una Toryen are mentioned in Dekatoryen, among others Jishikuropen evening Zhen, 5- Echiriden - 2-norbornene are preferred.

The Mooney viscosity ( _MLlH121V ) of the olefin rubber (b) at 121 ° C is preferably from 5 to ₃₅₀ , more preferably from 10 to improve moldability and mechanical strength. ~ 300. The higher the viscosity, the better the mechanical strength, while the lower the viscosity, the better the moldability.

The olefin rubber (b) may be an oil-extended rubber. When the oil-extended rubber is used, the content of the extender oil is usually 20 to 200 parts by weight per 100 parts by weight of the rubber excluding the extender oil. Extending oils are mineral oil based softeners and the like. Para mineral oil based softener There are fin-based, naphthene-based, and aroma-based softeners, and preferably paraffin-based. (B) When oil-extended rubber is used as the olefin-based rubber, the above-mentioned rubber viscosity is the same as the oil-extended rubber.

The olefin rubber (b) can be produced by a known method using any polymerization catalyst such as a Cidara-based catalyst, a vanadium-based catalyst, or a metallocene catalyst. The proportions of the polypropylene-based resin (a) and the olefin-based rubber (b) are preferably (a) 10 to 65% by weight and (b) 90 to 35% by weight, respectively, from the viewpoint of improving moldability and flexibility. More preferably, (a) is 15 to 60% by weight, and (b) is 85 to 40% by weight. However, the total weight of (a) and (b) shall be 100% by weight. More (a) is more excellent in moldability, while less (a) is more flexible.

As the component (A), a composition obtained by adding a cross-linking agent and a cross-linking assistant to a polypropylene resin (a) and a olefin rubber (b) and dynamically heat-treating the composition may be used. As cross-linking agents, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexine 3,1,3-bis (t-butyl) Peroxysopropyl) benzene, 1,1,1-di (t-butylperoxy) 3,5,5-trimethylcyclohexane, 2,5-dimethyl-1,2,5-di (t-butylpropyloxybenzoyl) hexine 1,3 Organooxidizing substances such as dicumyl peroxide can be used. Of these, 2,5-dimethyl-2,5- (t-butylvinyloxy) hexane is preferred.

Crosslinking aids include N, N'_m-phenylenebismaleimide, toluylenebismaleimide, p-quinonedioxime, nitrobenzene, diphenyldazine, trimethylolpropane, divinylbenzene, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, Trimethylolpropane Trimethacrylate, aryl methacrylate and the like can be mentioned, and among them, N, N'-m-phenylenebismaleimide and trimethylolpropane are preferable. As the styrene-based thermoplastic elastomer (A2) used in the present invention, a polymer block composed of at least two styrenes and 10 to 65% by weight of a polypropylene-based resin (a) and at least one conjugated Compound polymer A block copolymer comprising 90 to 35% by weight of a hydrogenated product (c) of a block copolymer is preferred from the viewpoints of moldability, flexibility and mechanical strength. However, the total weight of (a) and (c) is 100% by weight. As the conjugated diene compound (c), butadiene and isoprene are preferred. The ratio (weight ratio) of the styrene unit and the Z conjugated diene compound unit (c) is preferably from 10/90 to 50/50 from the viewpoint of further increasing mechanical strength and flexibility. Higher styrene units (lower conjugated gen compounds) have better mechanical strength, while higher styrene units have higher hydration gen compounds and higher flexibility.

Hydrogen of a block copolymer composed of a polypropylene resin (a), a polymer block composed of at least two styrenes, and a polymer block composed of at least one conjugated gen compound in a styrene thermoplastic elastomer (A 2) The content of the additive (c) is preferably (a) 10 to 65% by weight, (c) 90 to 35% by weight, and more preferably (a) from the viewpoint of further improving the moldability and flexibility. ) 20 to 50% by weight; (c) 80 to 50% by weight. However, the total weight of (a) and (c) is 100% by weight. More (a) is more excellent in moldability, while less (a) is more flexible. The details of (a) the polypropylene-based resin are as described above.

The antioxidant (B) is for preventing or reducing the thermal and oxidative deterioration of the thermoplastic elastomer composition, and is a primary antioxidant such as a phenol-based antioxidant and a amine-based antioxidant. And secondary antioxidants such as sulfur antioxidants and phosphorus antioxidants. These may be used alone or in combination of two or more.

Specific examples of the primary antioxidant include triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2,4-bis (n-octylthio) -1 6- (4-hydroxy-3,5-di-tert-butylanilino) 1 1 , 3,5-triazine, penyu erythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2,2-thiodiethylenebis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate], Octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, N, N'-hexamethylenebis (3,5-di-t-butyl-4-hydroxy-hydrocinnama Mido), 3,5-di-t-butyl-4-hydroxybenzylphosphonate-ethyl ester, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxy) Benzyl) benzene, tris- (3,5-di-tert-butyl-4-hydroxybenzyl) -isocyanurate, 2,4-bis [(octylthio) methyl] -10-cresol, isooctyl-3_ (3,5- Di-t-butyl-4-hydroxyphenyl) propionate, 2,6-di-tert-butyl-4-methylphenol, 3,9-bis [2- [3- (3-t-butyl-4-hydroxy-5-methylphenyl) L) 1-propio dioxyxyl] 1, 1-1-dimethylethyl] —2,4,8,10-tetraoxaspiro [5,5] pentane, butylhydroxytoluene, 2,6-di-tert-butyl-p-cresol, etc. Phenolic antioxidants, phenyl-α-naphthylamine, phenyl-β-naphthylamine, N, N'-diphenyl-ρ-phenylenediamine, Ν, N'-zy β-naphthyl-ρ-phenylenediamine, Ν-cyclohexyl N '-phenyl-ρ-phenylenediamine, Ν-phenylene-1, isopropyl-ρ-phenylenediamine, aldol-α-naphthylamine, 2,2,4-trimethyl-1,2 Amine-based antioxidants such as —dihydroquinone polymer and 6-ethoxy-2,2,4-trimethyl—1,2-dihydroquinone.

Specific examples of the secondary antioxidant include thiopis (β-naphthol), thiobis (Ν-feneru β-naphthylamine), 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, dodecylmercaptan, and tetramethylthiuram. Sulfur-based antioxidants such as monosulfide, tetramethylthiuram disulfide, nickel di'butyldithiolbamate, nickel isopropyl xanthate, dilauryl thiodipropionate, distearyl thiodipropionate, tetrakis (2,4-di-t 1,4'-Phiphene diphosphonite, distearylpentaerythritol diphosphite, cyclic neopentanetetraylbis (octadecyl phosphine) G), tris nonyl phenyl phosphite, bis (2,4-di-t_butyl phenyl) pen erythritol diphosphite, tris (2, 4-di-t-butyl phenyl phosphite) And the like.

The content of the component (B) in the thermoplastic elastomer composition is preferably 0.05 to 0.7 part by weight, more preferably 0.1 to 0.6 part by weight, based on 100 parts by weight of the component (A). It is. If the content of the component (B) is less than 0.05 part by weight, heat resistance may be poor. On the other hand, if it exceeds 0.7 part by weight, fogging resistance may be poor.

Light stabilizers (C) are used to prevent and reduce photodeterioration of thermoplastic elastomer compositions, and are classified into hindered amine light stabilizers and ultraviolet absorbers. These may be used in combination.

Specific examples of hindered amine light stabilizers include 2,2,6,6-tetramethyl-41-pyridyl stearate, 1,2,2,6,6-pentamethyl-4-piperidyl benzoate, N— (2,2,6,6-tetramethyl-4-piperidyl) dodecyl succinimide, 1-1 [(3,5-di-t-butyl-4-hydroxydroxyphenyl) propionyloxexetyl] —2,2,6 , 6-Tetramethyl-4-piberidyl (3-, 5-di-tert-butyl-4-hydroxyphenyl) propionate, bis (1,2,2,6,6-pentamethyl-14-piperidyl) sebacet, bis (1, 2,2,6,6-pentamethyl-4-piperidyl) 1-2_butyl_2— (3,5-di-t_butyl-4-hydroxybenzyl) malonate, N, N'-bis (2,2,6 , 6-tetramethyl-4-piperidyl) butanetetracarpoxy , Tetra (1,2,2,6,6-pentamethyl-14-piperidyl) butanetetracarboxylate, dimethyl succinate-11- (2-hydroxyethyl) -14-hydroxy-1,2,2,6,6 —Polycondensate of tetramethylpiperidine, bis (2,2,6,6-tetramethyl-4-piberidinyl) sebagate, fenulou 4-piberidinylka-one, and the like. Specific examples of the ultraviolet absorber include 2- (2'-hydroxy-3'-t-butyl-5'-methylphenyl) -1-5-benzobenzotriazole, 2- (2,1-hydroxy-3 ', 5' —Di—t-butylphenyl) _5-benzobenzene Azole, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2, -hydroxy-3 ', 5'-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-5 '— T-octylphenyl) benzotriazole, 2- (2'-hydroxy-3,, 5' dicumylphenyl) benzotriazole, 2,2 "-methylenebis (4-tert-octyl-16-benzotriazolyl) Benzotriazole ultraviolet absorbers, 2,4-dihydroxybenzophenone, 2-hydroxy-14-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 5,5,1-methylenebis (2 —Hydroxy-4-phenoxyphenone) ultraviolet absorbers such as —hydroxy-4-methoxybenzophenone).

The content of the component (C) in the thermoplastic elastomer composition is preferably 0.01 to 0.5 part by weight, more preferably 0.05 to 0.4 part by weight, per 100 parts by weight of the component (A). Department. If the content of the component (C) is less than 0.01 part by weight, light resistance may be poor. On the other hand, if it exceeds 0.5 part by weight, fogging resistance may be poor.

Component (D) of the present invention is a lubricant, which imparts lubricity to the surface of the molded article and improves scratch resistance. Preferred specific examples include unsaturated fatty acid amides such as ellamide and oleic acid amide, and saturated fatty acid amides such as behenic acid amide and stearic acid amide. The content of the component (D) in the thermoplastic elastomer composition is preferably 0.01 to 0.5 part by weight, more preferably 0.05 to 0.4 part by weight, per 100 parts by weight of the component (A). Department. If the content of the component (D) is less than 0.05 part by weight, the scratch resistance may be poor. On the other hand, if the content exceeds 0.4 part by weight, the fogging resistance may be poor.

Component (E) of the present invention is at least one selected from the group consisting of metal chlorides and aluminates. Examples of the metal chloride include lithium salt sodium, sodium chloride, potassium chloride, magnesium chloride, calcium chloride, iron chloride, and salt zinc chloride. Examples of the metal aluminate salt include lithium aluminate, Examples include sodium aluminate, potassium aluminate, magnesium aluminate, calcium aluminate and the like. These compounds use one of them Or two or more of them may be used in combination. Among these compounds, iron chloride and sodium aluminate are preferred from the viewpoints of fogging resistance, heat resistance, and light resistance. The content of the component (E) in the thermoplastic elastomer composition is preferably from 0.01 to 5 parts by weight, more preferably from 0.05 to 2 parts by weight, based on 100 parts by weight of the component (A). Parts by weight. If the content of the component (E) is 0.01 part by weight, fogging resistance may be poor. On the other hand, if it exceeds 0.5 part by weight, the resin may have poor heat resistance, light resistance, and scratch resistance. There is.

The thermoplastic elastomer composition of the present invention may contain an antistatic agent as another additive. Amide-based cations, polyhydric alcohol derivatives, stearic acid esters, glycerin fatty acid esters, polyethylene glycol

'Chole fatty acid ester, stearic acid monoglyceride, fatty acid monoglyceride and the like are used. The addition amount of the antistatic agent is preferably from 0.01 to 0.5 part by weight, more preferably from 0.05 to 0.4 part by weight, based on 100 parts by weight of the component (A). If the amount is less than 0.01 part by weight, the antistatic property may be poor, while if it exceeds 0.5 part by weight, the fogging resistance may be poor.

In addition, the thermoplastic elastomer composition of the present invention comprises inorganic fillers such as talc, hydrated talcite, calcium carbonate, and calcined kaolin; neutralizing agents such as calcium oxide, magnesium oxide, and zinc oxide; aluminum hydroxide, hydroxide Flame retardants such as magnesium and antimony oxides; silicone oils; pigments; copper damage inhibitors; nucleating agents and the like may be added.

In order to obtain the thermoplastic elastomer composition of the present invention, each component may be melt-kneaded using, for example, a twin-screw extruder, a Banbury mixer or the like.

The molded article of the thermoplastic elastomer composition of the present invention, by taking advantage of the above-mentioned excellent features, can be used for interior parts such as automobile airbag covers, armrests, console boxes, shift knobs, grab rails, and door trims, It is suitable for airbag cover applications. Example The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1

Sumitomo Chemical Co., Ltd. ethylene-propylene random copolymer Nobrene Z144A (hereinafter r-PP, MFR: 3 Og / 10min, ethylene content: 3.4% by weight) 50 parts by weight and Sumitomo Chemical Co., Ltd. 10 parts by weight of ethylene-propylene copolymer rubber Esplen 201 (hereinafter referred to as EPR-1, ML _{1 + 4} 12 I: 29, propylene content: 53% by weight) and Sumitomo Chemical Co., Ltd. ethylene-propylene copolymer Rubber Esplene 512 P (EPR-2, ML _1M 121 ° C: 68, propylene content: 31% by weight) 40 parts by weight, Irganox 1010 as an antioxidant (manufactured by Chino Specialty Chemicals) 0.2 parts by weight, Sumisorb 300 as a light stabilizer (hereinafter referred to as Light Stabilizer_1, manufactured by Sumitomo Chemical Co., Ltd.) 0.2 parts by weight, SANOL L S-770 (hereinafter referred to as Light Stabilizer-2, manufactured by Sankyo) 0.1 Parts by weight, LA-52 (hereinafter referred to as "lightfaster-3", manufactured by Asahi Denka Co., Ltd.) 12 (manufactured by Marubishi Yuka Co., Ltd.) 0.05 parts by weight, 0.8 parts by weight of Shii-Danietsu (III) hexahydrate 200 ° using a Labo Plastomill (Toyo Seiki Seisakusho, Model 65C150) The mixture was kneaded with C to obtain a thermoplastic elastomer composition. Then, pressing was performed at 20 to obtain a 2 mm thick sheet. The obtained sheet was cut into 25 mm x 100 mm, and a fogging test was performed at 100 ° (:, 20 hours) using the apparatus shown in Fig. 1, and after the test, the haze of the glass plate was measured using a haze meter manufactured by Suga Test Instruments Co., Ltd. A low haze value indicates good fogging properties, and the results are shown in Table 1.

Example 2

Example 1 was carried out in the same manner as in Example 1 except that 0.8 part by weight of sodium aluminate was used instead of iron chloride (II) hexahydrate. Table 1 shows the results.

Comparative Example 1

Example 1 was carried out in the same manner as in Example 1 except that iron (III) chloride hexahydrate was not used. Table 1 shows the results. Formulation Example 1 Example 2 Comparative Example 1 r-PP (parts by weight) 50 50 50

EPR-1 (Heavy capital) 10 10 10

EPR-2 (S amount) 40 40 40

Antioxidant (S part) 0.2 0.2 0.2

Lightfastener-1 (parts by weight) 0.2 0.2 0.2

Light fastener-2 (S part) 0.1 0.1 0.1

Lightfastener-3 (fi content) 0.1 0.1 0.1

Lubricant (fi content) 0.05 0.05 0.05

Iron chloride (ΠΙ) hexahydrate

0.8

(S volume capital)

Sodium anolemic acid

0.8

(Weight part)

Fogging resistance

0,8 18 53

HAZE (%)

Industrial applicability

As described above, according to the present invention, it is possible to provide a thermoplastic elastomer composition which maintains heat resistance, light resistance, scratch resistance, and the like at a satisfactory high level, and is excellent in force and fogging resistance. . The thermoplastic elastomer composition of the present invention is excellent in flexibility and mechanical strength, and a molded article of the composition is suitable as an automobile interior part.

Claims

The scope of the claims

1. Contains the following components (A) to (E), and the content of component (B) is 0.05 to 0.7 parts by weight per 100 parts by weight of component (A). The content of C) is 0.01 to 0.5 part by weight, the content of component (D) is 0.01 to 0.5 part by weight, and the content of component (E) is 0.01 to 0.5 part by weight. 5 parts by weight of a thermoplastic elastomer composition.

(A): Olefin-based thermoplastic elastomer (A1), styrene-based thermoplastic elastomer (A2), or a mixture thereof

(B): Antioxidant

(C): Light fastener

(D): Lubricant

(E): Metal chloride and Z or metal aluminate

2. A molded article comprising the thermoplastic elastomer composition according to claim 1.

3. The molded article according to claim 2, wherein the molded article is an automobile interior part.

4. The molded Po according to claim 3, wherein the automobile interior part is an airbag cover