JP2004002886A - Thermoplastic elastomer composition and upholstery by slush casting using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic elastomer composition for slush casting that furnishes sheets by slush casting with good properties, and maintains its powder flowability irrespective of the number of the casting, and to provide upholstery by slush casting that prevents the oligomer components, process oils, stabilizers, etc. from migrating to the surface, even after a standing or thermal aging. <P>SOLUTION: This thermoplastic elastomer composition for use as a material for upholstery by slush casting comprises at least a hydrogenated styrene-butadiene rubber, a polypropylene resin, an internal mold release, and a low-density polyethylene resin that has a melt flow rate (MFR) of not less than 20 g/10 min. according to JIS K6760 at 190°C and 2.16 kgf loading, and a melting point of 40°C or higher. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a thermoplastic elastomer composition and a slush-molded skin using the same, and more particularly, to a thermoplastic elastomer composition which maintains powder flowability regardless of the number of moldings and has no change in surface state due to heat aging. The present invention relates to a product and a slash-formed skin using the same.

粉末 As a powder molding method using a soft powder material, a powder slush molding method using a soft vinyl chloride resin powder is widely used for the skin of automobile interior parts such as an instrument panel, a console box, and a door trim. This is a soft touch, and can be provided with leather grain and stitches, and has good design properties such as a large degree of freedom in design.

Unlike other molding methods such as injection molding and compression molding, this molding method does not apply shaping pressure, so the powder material must have good fluidity in order to uniformly adhere the powder material to a mold having a complicated shape during molding. It is necessary to be excellent, and since the powder attached to the mold melts and flows even under no pressure to form a film, the melt viscosity is also required to be low.
Further, it was necessary that the molded skin by cooling the mold could be released more easily than the mold.

As one method for improving this, Patent Document 1 proposes that a mixture of a polypropylene resin and a specific styrene-based thermoplastic elastomer in a weight ratio of 70/30 to 30/70 is used after pulverization. ing. Here, the styrene-based thermoplastic elastomer is a styrene / ethylene / butylene / styrene block copolymer having a styrene content of 20% by weight or less, a styrene / ethylene propylene / styrene block copolymer having a styrene content of 20% by weight or less, and a styrene content of 20% by weight. % Or less of a hydrogenated styrene-butadiene rubber, and has a good compatibility with a polypropylene resin and is a composition suitable for powder molding.

は This composition is suitable for a skin material because the hydrogenated styrene-butadiene rubber is finely dispersed in the polypropylene resin when the polypropylene resin and the hydrogenated styrene-butadiene rubber are mixed. However, when used for slush molded skin, hydrogenated styrene-butadiene rubber has poor oil-absorbing ability, so oligomer components, process oils and stabilizers in the composition migrate to the surface and have gloss, tackiness, and whitening. There were drawbacks.

In particular, a transparent coating film was formed to reinforce the surface of the slush-molded skin, and after heat treatment, there was a disadvantage that the above-mentioned oligomer components, process oils, stabilizers, and the like easily migrated to the surface over time. . In addition, since the thermoplastic elastomer composition powder is in an atmosphere at room temperature or higher during slush molding, oligomer components, process oils, stabilizers, and the like in the composition migrate to the powder surface, and the powder adheres. It had good properties, easily blocked with the passage of days, and had poor powder fluidity. Further, when the process oil was excluded, the MFR value of the composition was reduced to less than 20 g / 10 minutes at 230 ° C. and a load of 2.16 kg, and the sheet property at the time of slash was remarkably deteriorated.
JP-A-7-82433

The problem to be solved is that the thermoplastic elastomer composition for slush molding has good sheet properties during slush molding and maintains powder fluidity regardless of the number of moldings, and oligomer components even after standing and heat aging. The purpose of the present invention is to provide a slush-molded skin which prevents surface oils such as process oils and stabilizers from migrating.

The invention according to claim 1 of the present application relates to a thermoplastic elastomer composition used as a material for a slush molded skin, wherein at least hydrogenated styrene butadiene rubber, a polypropylene resin, an internal mold release agent, and a melt flow rate (MFR) according to JIS K6760. A thermoplastic elastomer composition comprising a low-density polyethylene resin having a melting point of not less than 20 g / 10 min at 190 ° C. and a load of 2.16 kgf and having a melting point of not less than 40 ° C., wherein the thermoplastic elastomer composition has a melt flow rate (MFR) is not less than 20 g / 10 min under a load of 2.16 kg at 230 ° C., and has excellent melt flowability, good sheet formability at the time of slush molding, and a skin obtained by slush molding this powder. Surface conditions such as gloss, adhesion, and whitening even after standing and heat aging Change is better without.

The invention according to claim 2 of the present application resides in a thermoplastic elastomer composition obtained by adding an elastomer excellent in oil absorption to the composition according to claim 1, which is superior to the MFR value of the composition according to claim 1 and has a sheet property. Better.

The invention according to claim 3 of the present application resides in a thermoplastic elastomer composition obtained by adding a process oil to the composition according to claim 1 or 2, which is superior to the MFR value of the composition according to claim 2 and has better sheet properties. It is.

The invention of claim 4 of the present application is characterized in that at least hydrogenated styrene-butadiene rubber, polypropylene resin, internal release agent, and melt flow rate (MFR) are not less than 20 g / 10 min at 190 ° C. and 2.16 kg load according to JIS K6760. The slush-molded skin obtained by slush-molding a thermoplastic elastomer composition composed of a low-density polyethylene resin having a melting point of 40 ° C. or higher, and changes in surface conditions such as gloss, adhesion, and whitening even after standing and heat aging. Not excellent.

The invention of claim 5 of the present application resides in a skin obtained by slush-molding a thermoplastic elastomer composition to which an elastomer excellent in oil absorbency is added in claim 4, and has a surface having gloss, adhesion, whitening, etc., even after standing and heat aging. Excellent with no change in state.

The invention of claim 6 of the present application resides in a skin obtained by slush-molding a thermoplastic elastomer composition to which a process oil has been added according to claim 4 or 5, and has a surface state such as gloss, adhesion, and whitening even after standing and heat aging. Excellent without change.

The present invention provides a polypropylene resin having at least hydrogenated styrene butadiene rubber and a melt flow rate (MFR) of not less than 20 g / 10 min according to JIS K6760 at a load of 190 ° C. and 2.16 kgf and a melting point of not less than 40 ° C. A thermoplastic elastomer composition to which a low-density polyethylene resin is added, and a slash-molded skin using the same, which has excellent melt fluidity and good sheet properties, and maintains powder fluidity regardless of the number of moldings. It is possible to obtain a molded sheet having excellent melt fluidity, excellent tensile strength, and having no adhesive gloss on the surface of the molded sheet even after heat aging.

Further, the thermoplastic elastomer composition has a melt flow rate (MFR) of 230 g or more at 230 ° C. and a load of 2.16 kg of 20 g / 10 min or more, and has excellent melt flowability and good sheet formability during slush molding. Also, the surface obtained by slush molding this powder is excellent without any change in surface state such as gloss, adhesion and whitening even after standing and heat aging.

In addition, at least a hydrogenated styrene-butadiene rubber, a process oil, an elastomer having excellent oil absorbing ability, and a low-molecular-weight polyethylene resin of a low-density polyethylene wax having a molecular weight of 1,500 or more and a melting point of 40 ° C. or more are added to a polypropylene resin. By kneading them under heating, a thermoplastic elastomer composition having better melt fluidity than the above and a slush-molded skin using the same can be obtained.

The polypropylene resin used in the present invention may be any of a polypropylene homopolymer, a block and a random copolymer with an α-olefin, and particularly, a block or a random copolymer using ethylene as the α-olefin is a flexible material of the molded article. It is preferable in terms of properties. Further, in order to use the powder slush molding without applying pressure, an MFR (melt flow rate) measured at 230 ° C. and a load of 2.16 kgf according to JIS K7210 as an index of melt fluidity of the polypropylene resin is 100 to 800 g / 10 min. It is necessary to be.
The polypropylene resin having the above MFR value has good melt fluidity, excellent melt fluidity without using an organic peroxide, low melt viscosity, excellent tensile strength, and heat aging on the molded sheet surface. It is possible to obtain one having no sticky gloss.

When a polypropylene resin having an MFR value of less than 100 g / 10 minutes and lacking melt flowability is used, 0.02 to 5.0 parts by weight of an organic peroxide is added, and at a temperature of 120 to 250 ° C. By kneading, the molecular weight of the polypropylene resin can be reduced so that the MFR value becomes 100 to 800 g / 10 minutes.

When a polypropylene resin having an MFR value of less than 100 g / 10 minutes and lacking in melt fluidity is used, after adding an organic peroxide to the polypropylene resin and melt-kneading at a temperature of 120 to 250 ° C., Hydrogenated styrene butadiene rubber (H-SBR) can be melt-kneaded. When H-SBR and an organic peroxide are simultaneously melt-kneaded, H-SBR has a low molecular weight and migrates to the surface of a molded sheet, and after heat aging, tackiness and gloss occur on the surface.

Examples of the organic peroxide include diacyl peroxide, peroxyester, diallyl peroxide, di-t-butyl peroxide, t-butyl cumyl peroxide, and dicumyl peroxide which are usually used for crosslinking rubber and resins. Oxide, 2.5-dimethyl-2.5-di (t-butylperoxy) -hexane-3,1,3-bis (t-butylperoxy-isopropyl) benzene, 1,1-di-butylperoxy -3,3,5-trimethylcyclohexane and the like, and those having a one-minute half-life by thermal decomposition of 150 to 250 ° C. are preferable.

(4) In the process of kneading under heating at 120 to 250 ° C., the organic peroxide cuts the main chain of the polypropylene resin to reduce the molecular weight, thereby giving the thermoplastic elastomer composition a high melt fluidity. The addition amount of the organic peroxide is 0.02 to 5.0% by weight in the thermoplastic elastomer composition, and when the amount is less than 0.02% by weight, the decomposition ability to cut the main chain of the polypropylene resin is small, High melt fluidity cannot be imparted to the thermoplastic elastomer composition. On the other hand, if the content exceeds 5.0% by weight, the decomposition becomes excessive and the mechanical properties such as the tensile strength of the powder molded product decrease.

Hydrogenated styrene-butadiene rubber (H-SBR) has excellent compatibility with polypropylene resin, and when kneaded with polypropylene resin, it becomes flexible, and a thermoplastic elastomer composition that is hard to bend or whiten can be obtained. The styrene content of H-SBR is preferably 30% by weight or less, and 5 to 15% by weight is appropriate for obtaining a flexible skin.

H-SBR is different from SEBS which is a block copolymer in that styrene-butadiene rubber in which styrene and butadiene are randomly copolymerized is hydrogenated. A typical example is the Dynalon series, a product made by Nippon Synthetic Rubber Co., Ltd.

混合 The mixing amount of the polypropylene resin and H-SBR is 80/20 to 20/80 in weight ratio. As the amount of the polypropylene resin increases, the molded skin becomes harder, and when the amount decreases, the tensile strength decreases.

In the thermoplastic elastomer composition for slush molding, in order to ensure that the MFR is not less than 20 g / 10 min under a load of 2.16 kg at 230 ° C., the polyethylene resin to be added in the present invention has a MFR of 190 ° C. according to JIS K6760. There is a low-density polyethylene resin (hereinafter simply referred to as a polyethylene resin) having characteristics of 20 g / 10 min or more at a load of 2.16 kg and a melting point of 40 ° C. or more.

In addition, the polyethylene resin used in the present invention is originally poorly compatible with the polypropylene resin and has very poor physical properties, but H-SBR acts as a compatibilizer between the polyethylene resin and the polypropylene resin. It is at the same level as the physical properties (the physical properties in JP-A-7-82433).

Here, by adding the polyethylene resin, there is an effect of preventing bloom of oil and stabilizer, and the sticking due to bloom at the time of the powder is eliminated, the powder fluidity is improved, and the blocking does not occur. In the slush molded skin, gloss, adhesion and whitening caused by bloom during standing or heat aging are suppressed. The addition amount is preferably from 5 to 200 parts by weight based on 100 parts by weight of the elastomer.

In the present invention, the addition of process oil has the effect of being absorbed by the elastomer component in the composition and lowering the melt viscosity, lowering the hardness of the skin, and having flexibility. The above process oils are used for rubber and are classified into paraffinic, naphthenic, and aroma-based oils. Paraffin-based oils are preferred because of their compatibility with elastomer components. The addition amount is preferably 5 to 200 parts by weight based on 100 parts by weight of the elastomer having excellent oil absorbing ability. If it exceeds 200 parts by weight, the tensile properties are reduced, and if it is less than 5 parts by weight, the melt viscosity does not decrease and the skin becomes hard.

Elastomers with excellent oil-absorbing ability are compatible with the polypropylene resin and have the property of absorbing the oligomer components in the process oil and the composition, and include styrene-ethylenebutylene-styrene block copolymer (SEBS) and styrene.・ Styrene block copolymer thermoplastic elastomer such as ethylene propylene / styrene block copolymer (SEPS), olefin crystal ・ ethylene butylene / olefin crystal block copolymer (CEBC), ethylene propylene rubber (EPR), and ethylene / octene copolymer ( POE).

The above SEBS is obtained by hydrogenating styrene / butadiene / styrene block copolymer (SBS), and includes Clayton G series, a product of Ciel Chemical Co., Ltd., and Tuftec H series, a product of Asahi Kasei Corporation. In this SEBS, the strength increases as the styrene content increases, but the flexibility decreases. Further, in the case of the same SEBS, the styrene hard segments are melted at the time of slush molding and agglomerate, and it may be difficult to obtain a smooth sheet-like molded body. Therefore, the styrene content is preferably 40% by weight or less.

SEPS is a hydrogenated product of styrene / isoprene / styrene block copolymer (SIS), and is typically Septon, a product of Kuraray Co., Ltd. As in the case of SEBS, the styrene content is preferably 40% by weight or less because the flexibility decreases as the styrene content increases.

In addition, the above-mentioned elastomer having excellent oil-absorbing ability is inferior in compatibility with the polypropylene resin as compared with H-SBR, and when kneaded and added to the polypropylene resin, the elastomer is dispersed in a size of μm unit, so that the tensile properties are reduced. There is a tendency. However, when H-SBR and process oil are added to the polypropylene resin, the oligomer component in the composition migrates (bleeds) to the surface because the H-SBR has poor oil-absorbing ability and has adhesiveness. Since the elastomer powder used for powder slush molding also has adhesiveness, it tends to be blocked, so that the powder fluidity and the surface of the powder lack mold release properties. When an elastomer having an excellent oil-absorbing ability is added thereto, the bleed can be considerably prevented by absorbing the oligomer component and oil in the composition. However, it was not perfect but slightly bleed. In addition, the bleed is almost eliminated in the system to which the polyethylene resin is added.

エ ラ ス ト マ ー The amount of the elastomer having excellent oil absorbing ability is 20 to 250 parts by weight based on 100 parts by weight of H-SBR. If the amount is less than 20 parts by weight, the oligomer component and the oil in the composition cannot be sufficiently absorbed. If the amount exceeds 250 parts by weight, the dispersion with the polypropylene resin becomes poor, and the tensile properties tend to decrease.

As the heat stabilizer, those used for ordinary polyolefins can be used. Generally, phenol and a phosphorus-based antioxidant are used in combination, but are not particularly limited. As the light stabilizer, a hindered amine or benzotriazole type radical scavenger may be used. Organic and inorganic pigments suitable for ordinary olefins are used. Further, a lubricant such as a fatty acid metal salt and a filler such as calcium carbonate and talc are added as required.

The mixture of these compounds is melt-kneaded by the following six methods.
(1) A method in which H-SBR, polyethylene resin and the like are simultaneously added to a polypropylene resin having an MFR (melt flow rate JIS K7210) of 100 to 800 g / 10 minutes, and these are kneaded at a temperature of 120 to 250 ° C. Yes, in this case, no organic peroxide is added.

(2) H-SBR, a polyethylene resin, an elastomer having excellent oil absorbing ability, etc. are simultaneously added to a polypropylene resin having an MFR (melt flow rate JIS K7210) of 100 to 800 g / 10 min. This is a method of kneading at a temperature, in which case no organic peroxide is added.

(3) H-SBR, a polyethylene resin, a process oil, an elastomer excellent in oil absorption ability, etc. are simultaneously added to a polypropylene resin having an MFR (melt flow rate JIS K7210) of 100 to 800 g / 10 min. This is a method of kneading at a temperature of 250 ° C., in which case no organic peroxide is added.

(4) 0.02-5.0 parts by weight of an organic peroxide is previously added to a polypropylene resin having an MFR of less than 100 g / 10 min, and the mixture is kneaded at a temperature of 120 to 250 ° C. to obtain an MFR of 100 to 800 g / 10 min. There is a method in which H-SBR, polyethylene resin, and the like are simultaneously added to the polypropylene resin adjusted in minutes, and these are kneaded at a temperature of 120 to 250 ° C.

(5) After adding 0.02 to 5.0 parts by weight of an organic peroxide to a polypropylene resin having an MFR of less than 100 g / 10 minutes and an elastomer having excellent oil absorbing ability, and kneading at a temperature of 120 to 250 ° C, Further, there is a method in which H-SBR, polyethylene resin and the like are added thereto and kneaded at a temperature of 120 to 250 ° C.

(6) 0.02 to 5.0 parts by weight of an organic peroxide is added to a polypropylene resin having an MFR of less than 100 g / 10 minutes, an elastomer having excellent oil absorbing ability, and process oil, and kneaded at a temperature of 120 to 250 ° C. After that, there is a method in which H-SBR, polyethylene resin and the like are further added thereto and kneaded at a temperature of 120 to 250 ° C.

The method of addition and kneading is as follows. The additive is dry-blended using a V-type blender, tumbler, Henschel mixer or the like, supplied from a raw material supply hopper, process oil is injected from a vent port, and the temperature is adjusted to a range of 120 to 250 ° C. The mixture is melt-kneaded in a twin-screw extruder and pelletized.

Further, the process oil is added to H-SBR, which is an elastomer component, and an elastomer having excellent oil absorption by a kneader, a Banbury mixer or the like, which is a closed-type kneader, and the mixture is kneaded into pellets. It can be blended and melt-kneaded with a single-screw or twin-screw extruder whose temperature is controlled in the range of 120 to 250 ° C. to form pellets.

溶 融 The MFR, which is the melt viscosity of the obtained pellets, is preferably not less than 20 g / 10 minutes at 230 ° C under a load of 2.16 kgf. If it is less than this, the melt fluidity of the composition tends to be low, and pinholes tend to occur in the skin.

The pellets obtained from the above blending are finely pulverized by using an impact type fine pulverizer such as a turbo mill, a pin mill, a hammer mill and the like. At this time, it is usually frozen and pulverized using liquid nitrogen. Further, depending on the composition, the molten resin can be pulverized by spraying or cooling with a spray or disk atomizer.
The pulverized product is passed through a sieve having a particle size of at least 1,000 μm by means of a sieve or the like, and those having an average particle size of 100 to 800 μm are collected, and an organic or inorganic powdery improver is added thereto and mixed. Used for powder slush molding.

Next, powder slush molding is performed using the elastomer composition. In this molding, the composition is dropped mainly by gravity into a mold heated to a temperature higher than the melting point of the composition, and after a certain period of time, the mold is inverted and excess composition is collected in a collection box. The composition adheres as a layer to the mold surface, and melts over time to form a skin layer. Then, the mold is cooled to release the skin layer, and this is repeatedly performed.

As the heating method of the type, a method of oil circulation or putting into a hot blast stove is general. The oil circulation is easy to adjust the mold temperature by the pipe arrangement, but is heated only from the mold surface. On the other hand, when a hot blast stove is used, heating can be performed from both the mold surface and the back surface of the molded product, but the hot air is often set to 300 ° C. or higher in consideration of productivity. It is necessary to consider the prescription and conditions so as not to cause oxidative deterioration.

The hot air method is effective when performing powder slush molding in multiple layers (2 or 3). That is, the first powder to be the outermost layer is slush-molded in a heated mold, the second powder is adhered in a semi-molten state, and if necessary, the third powder is slush-molded, and then heated and melted. In this case, if the heating is performed only from the mold surface side, the heat transfer is insufficient, so that a hot blast stove system capable of heating from the back surface of the molded product is often used.

Examples 1-2
In Examples 1 and 2, high-flow polypropylene resin, H-SBR, polyethylene resin, stabilizer, release agent, and MFR having an MFR of 100 to 800 g / 10 min measured at 230 ° C. under a load of 2.16 kgf according to JIS K7210, Was dry-blended with a tumbler, supplied from a raw material supply hopper of a twin-screw extruder (PCM45, manufactured by Ikegai Iron & Steel Co., Ltd.), kneaded at 220 ° C. and 300 rpm, and extruded into pellets. The pellets obtained above were immersed in liquid nitrogen, thrown into a Turbomill T250-4J (manufactured by Turbo Kogyo Co., Ltd.), and pulverized to collect only a 1,000 μm sieve.

Example 3, Comparative Examples 1-3
In Example 3 and Comparative Examples 1 to 3, kneading was performed twice using a twin-screw extruder (PCM45, manufactured by Ikegai Iron and Steel Co., Ltd.). In the first kneading, a raw material supply hopper of a twin-screw extruder (PCM45, manufactured by Ikegai Iron & Steel Co., Ltd.) obtained by dry-blending a polypropylene resin, an elastomer having excellent oil-absorbing ability, an organic peroxide, and a release agent by tumbling The mixture was kneaded at 230 ° C. and 100 rpm while the process oil was injected from the vent port, and extruded into pellets. Subsequently, the pellets produced by the first kneading were dry-blended with H-SBR, polyethylene resin, and stabilizer by a tumbler, and supplied from a raw material supply hopper of a twin-screw extruder (PCM45, manufactured by Ikegai Iron and Steel Co., Ltd.). The mixture was kneaded at 200 ° C. and 300 rpm and extruded into pellets. The parentheses in the table indicate those added in the second time.
The pellets obtained above were immersed in liquid nitrogen, thrown into a Turbomill T250-4J (manufactured by Turbo Kogyo Co., Ltd.), and pulverized to collect only a 1,000 μm sieve.

Next, powder slush molding was performed using the above powder composition. As a method of powder slush molding, first, a 150 mm × 150 mm × 3 mm plate with a leather grain pattern is heated to 250 ° C. in an oven, and about 800 g of the powder composition is placed thereon and placed for 10 minutes. After adhering, the powder which did not adhere to the melt was removed, and heated in an oven adjusted to 300 ° C. for 60 seconds, taken out of the oven and cooled with water, and the skin having a thickness of about 0.8 mm was released.

(4) The following methods were used to evaluate the melt viscosity of the above pellets, the powder fluidity of the pulverized material, the formability of slash-formed sheets, the tensile properties of the skin, and the presence or absence of adhesion and gloss on the skin surface after heat aging. Table 1 shows the obtained results.

The melt viscosity was measured by measuring the melt flow rate of the pellet at 230 ° C and a load of 2.16 kgf according to JIS K7210.

は For powder fluidity, the flow rate was measured to determine the quality. The flow speed was determined by measuring the time required for 100 g of the powder to completely fall from the funnel-shaped portion using a bulk specific gravity measuring device according to JIS K6721 to determine the quality of the powder.

The slush sheet moldability was evaluated as ○ when almost no pinholes on the skin obtained by slush molding were visually observed, and as × when many pinholes were observed.

The tensile properties were obtained by punching out the skin obtained by slush molding with a JIS No. 3 dumbbell, and measuring the tensile strength and elongation at a tensile speed of 200 mm / min.

Regarding the presence and absence of adhesion and gloss on the skin surface after heat aging, after heat aging for 200 hours in an oven where the skin was adjusted to 120 ° C, the adhesiveness of the surface was determined by tentacles, and the gloss was judged by visual inspection. did.光 沢 indicates that no gloss was observed on the surface, and x indicates slightly observed. These results are also shown in Table 1.

As a result, in Examples 1 to 3, the MFR of the pellets was 230 g at 230 ° C. and a load of 2.16 kgf of 20 g / 10 min or more according to JIS K7210. Physical properties equivalent to those of No. 1 were maintained, and no tackiness and glossiness were observed on the surface of the epidermis after heat aging. In addition, the powder fluidity of the powder did not flow down in Comparative Example 1 of the conventional formulation, but all of Examples 1 to 3 had good flowability.
However, as in Comparative Examples 2-3, when a polyethylene resin having an MFR of less than 20 g / 10 min at 190 ° C. and a load of 2.16 kgf according to JIS K6760 is added, the MFR of the thermoplastic elastomer composition becomes 230 ° C. according to JIS K7210. , 2.16 kgf, the load was less than 20 g / 10 min, and the sheet properties were poor.

The thermoplastic elastomer composition of the present invention can be applied by a powder slush molding method, and the slush-molded skin using the same can be widely used for the skin of automobile interior parts such as instrument panels, console boxes and door trims.

Claims (6)

In a thermoplastic elastomer composition used as a material for a slush molded skin, at least a hydrogenated styrene-butadiene rubber, a polypropylene resin, an internal release agent, and a melt flow rate (MFR) are measured at 190 ° C. and 2.16 kgf according to JIS K6760. A thermoplastic elastomer composition comprising a low-density polyethylene resin having a melting point of 20 ° C. or more and a melting point of 40 ° C. or more. (4) The thermoplastic elastomer composition according to the above (1), further comprising an elastomer excellent in oil absorbency. 3. The thermoplastic elastomer composition according to claim 1, wherein a process oil is added. Hydrogenated styrene-butadiene rubber, polypropylene resin, internal mold release agent, and melt flow rate (MFR) at 190 ° C. according to JIS K6760, 20 g / 10 minutes or more under a load of 2.16 kg, and melting point of 40 ° C. or more A slush-molded skin obtained by subjecting a thermoplastic elastomer composition comprising a low-density polyethylene resin to slush molding. 5. The slush-molded skin according to claim 4, wherein the thermoplastic elastomer composition to which an elastomer having excellent oil absorbency is added is slush-molded. The slush-molded skin according to claim 4 or 5, wherein the thermoplastic elastomer composition containing process oil is slush-molded.