JP2000309637A - Method for producing thermoplastic elastomer composition, thermoplastic elastomer composition, and interior part for car - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for effectively producing a thermoplastic elastomer composition having a homogeneous composition ratio and a thermoplastic elastomer composition excellent in anti-fogging property. SOLUTION: This thermoplastic elastomer composition is produced by supplying a rubber and a thermoplastic resin to an extruder from separate supply ports and by melting and kneading the materials. The thermoplastic elastomer composition which is produced by the method for producing the thermoplastic elastomer composition has <=2% haze in a glass plate, which is determined using an apparatus according to the rule of ISO 6452 after 20 hours heating at 100 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a thermoplastic elastomer composition by melt-kneading a rubber and a thermoplastic resin with an extruder, and to a thermoplastic elastomer composition.

[0002]

2. Description of the Related Art A thermoplastic elastomer composition is characterized in that a vulcanization step is not required and that it can be processed by a usual molding machine for thermoplastic resin, and is used for producing automobile parts, home electric parts and miscellaneous goods. Applications have been developed in a wide range of fields, including the beginning. As such a thermoplastic elastomer composition, an olefin-based thermoplastic elastomer composition, a styrene-based thermoplastic elastomer composition, and the like are known. As the former, a non-crosslinked type composition obtained by melt-kneading an olefin copolymer rubber and an olefin polymer resin, or an olefin copolymer rubber and an olefin polymer in the presence of a crosslinking agent such as an organic peroxide. BACKGROUND ART A crosslinked composition obtained by melt-kneading a resin and dynamically crosslinking the resin is generally known. Further, as the latter, styrene-butadiene block copolymers, styrene-isoprene block copolymers, and compositions of hydrogenated polymers and olefin polymer resins are known.

[0003] As a method for producing a non-crosslinked type thermoplastic elastomer composition, there is known a method in which rubber and a thermoplastic resin are kneaded by a closed kneader exemplified by a Banbury or a kneader. However, this method has a problem that it is not an efficient method because it uses a low productivity batch-type kneader exemplified by a banbury or a kneader.

[0004] As a method for producing a crosslinked type thermoplastic elastomer composition, a rubber and a thermoplastic resin are kneaded in advance by a closed kneader exemplified by a Banbury or a kneader, and then the kneaded product is granulated. After pelletizing,
There is a method of performing dynamic crosslinking by melt-kneading the pellets and a crosslinking agent with an extruder. However, this method requires (1) a step of kneading the rubber and the thermoplastic resin prior to the dynamic crosslinking, and (2) a low productivity batch method exemplified by a Banbury or kneader in this step. However, the use of a kneader has a problem that it is a complicated and inefficient method.

[0005] JP-A-58-25340 and JP-A-5-25340
No. 8-152023 discloses that a mixture of a particulate olefin copolymer rubber and a pelletized olefin polymer resin is supplied to an extruder, and the olefin copolymer rubber and the olefin polymer resin are melt-kneaded. A method of dynamically crosslinking is shown. However, because the particulate olefin copolymer rubber is cohesive, a pellet-sized one cannot be obtained, and as a result, the particulate olefin copolymer rubber is
It becomes larger than the pellets of the olefin polymer resin, and the mixture of the two is easily classified in the hopper, and it is difficult to obtain a thermoplastic elastomer composition having a uniform composition ratio between the olefin copolymer rubber and the olefin polymer resin.

The thermoplastic elastomer composition is being widely used as an automobile interior part exemplified by an instrument panel (dashboard) which is required to have excellent fogging resistance. The method requires that the processing time required for the production of the composition is long, so that the rubber or resin deteriorates during the processing and volatile low molecular weight compounds are by-produced, and as a result, the thermoplastic resin having excellent fogging resistance There is a problem that it is difficult to obtain an elastomer composition. Here, "fogging resistance" refers to the case of an automobile as an example, and various volatile low molecular weight compounds contained in the composition are volatilized and adhere to the window glass of the automobile. Cloudiness, and as a result, does not cause inconvenience of deteriorating the occupant's visibility.

[0007]

SUMMARY OF THE INVENTION Under these circumstances, an object of the present invention is to provide a method for efficiently producing a thermoplastic elastomer composition having a uniform composition ratio, and a thermoplastic elastomer having excellent fogging resistance. It is to provide a composition.

[0008]

That is, the present invention relates to a method for producing a thermoplastic elastomer composition in which rubber and a thermoplastic resin are supplied to an extruder through separate supply ports and melt-kneaded. Further, the present invention provides a thermoplastic elastomer composition produced by the method for producing a thermoplastic elastomer composition, and a glass which is measured at a heating temperature of 100 ° C. and a heating time of 20 hours using an apparatus conforming to ISO 6452. The present invention relates to a thermoplastic elastomer composition having a haze of 2% or less. Hereinafter, the present invention will be described in detail.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The method for producing the thermoplastic elastomer composition of the present invention is not particularly limited to the rubber used, but is suitably applied to a cohesive rubber. Here, the cohesive rubber, when the rubber is in the form of pellets, the pellets adhere to each other, the aggregates of the pellets, and,
A rubber that has the property that its mass does not collapse easily.

Examples of such cohesive rubbers include styrene copolymer rubbers such as olefin copolymer rubber, emulsion-polymerized styrene-butadiene rubber, solution-polymerized styrene-butadiene rubber, polyisobutylene rubber, butadiene rubber, natural rubber, and isoprene rubber. , Alphin rubber, acrylonitrile-butadiene rubber, fluoro rubber, vinyl pyridine rubber, silicone rubber, butadiene-methyl methacrylate rubber, acrylic rubber, ethylene-acryl rubber, urethane rubber, epichlorohydrin rubber, butyl rubber, chlorobutyl rubber, bromobutyl rubber, etc. No. The production method of the present invention is particularly suitable for olefin copolymer rubber among these.

The above-mentioned “olefin copolymer rubber” is:
A repeating unit derived from an olefin is contained in the rubber in an amount of 5%.
It means an amorphous, random elastic copolymer containing 0 mol% or more. Examples of the olefin copolymer rubber include a copolymer obtained by copolymerizing a combination of two or more monomers selected from the group consisting of an α-olefin having 3 to 20 carbon atoms and ethylene.
As the α-olefin having 3 to 20 carbon atoms, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, and 1-dodecene Linear α-olefins exemplified by, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nanodecene and 1-eicosene;
And 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, 2-ethyl-1-
The branched α-olefins exemplified by hexene and 2,2,4-trimethyl-1-pentene can be exemplified.

As a combination of two or more kinds of monomers selected from the group consisting of the α-olefin having 3 to 20 carbon atoms and ethylene, ethylene / propylene, ethylene / 1-butene, ethylene / 1-hexene,
Ethylene / 1-octene, propylene / 1-butene, propylene / 1-hexene, propylene / 1-octene,
Ethylene / propylene / 1-butene, ethylene / propylene / 1-hexene, ethylene / propylene / 1-octene, propylene / 1-butene / 1-hexene, propylene / 1-butene / 1-octene, propylene / 1-butene / 1-hexene / 1-octene, ethylene / propylene / 1-butene / 1-hexene, ethylene / propylene / 1-butene / 1-octene, and combinations of ethylene / propylene / 1-butene / 1-hexene / 1-octene Can be exemplified.

The olefin copolymer rubber has 3 carbon atoms.
It may be a copolymer of two or more kinds of monomers selected from the group consisting of α-olefins and ethylene and a non-conjugated polyene. Examples of the non-conjugated polyene include an aliphatic non-conjugated polyene, an alicyclic non-conjugated polyene, and an aromatic non-conjugated polyene. The aliphatic non-conjugated polyene includes a linear aliphatic non-conjugated polyene and a branched aliphatic non-conjugated polyene. In these non-conjugated polyenes, a hydrogen atom in the molecule may be substituted with a halogen atom, an alkoxy group, an aryl group, an aryloxy group, an aralkyl group, an aralkyloxy group, or the like.

Specific examples of the aliphatic non-conjugated polyene include:
1,4-hexadiene, 1,5-hexadiene, 1,6
-Heptadiene, 1,6-octadiene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene,
1,13-tetradecadiene, 1,5,9-decatriene, 3-methyl-1,4-hexadiene, 4-methyl-
1,4-hexadiene, 5-methyl-1,4-hexadiene, 4-ethyl-1,4-hexadiene, 3-methyl-1,5-hexadiene, 3,3-dimethyl-1,4-
Hexadiene, 3,4-dimethyl-1,5-hexadiene, 5-methyl-1,4-heptadiene, 5-ethyl-
1,4-heptadiene, 5-methyl-1,5-heptadiene, 6-methyl-1,5-heptadiene, 5-ethyl-1,5-heptadiene, 3-methyl-1,6-heptadiene, 4-methyl- 1,6-heptadiene, 4,4-
Dimethyl-1,6-heptadiene, 4-ethyl-1,6
Heptadiene, 4-methyl-1,4-octadiene,
5-methyl-1,4-octadiene, 4-ethyl-1,
4-octadiene, 5-ethyl-1,4-octadiene, 5-methyl-1,5-octadiene, 6-methyl-
1,5-octadiene, 5-ethyl-1,5-octadiene, 6-ethyl-1,5-octadiene, 6-methyl-1,6-octadiene, 7-methyl-1,6-octadiene, 6-ethyl- 1,6-octadiene, 6-propyl-1,6-octadiene, 6-butyl-1,6-octadiene, 4-methyl-1,4-nonadiene, 5-methyl-1,4-nonadiene, 4-ethyl- 1,4-nonadiene, 5-ethyl-1,4-nonadiene, 5-methyl-1,5-nonadiene, 6-methyl-1,5-nonadiene, 5-ethyl-1,5-nonadiene, 6-ethyl-
1,5-nonadiene, 6-methyl-1,6-nonadiene, 7-methyl-1,6-nonadiene, 6-ethyl-
1,6-nonadiene, 7-ethyl-1,6-nonadiene, 7-methyl-1,7-nonadiene, 8-methyl-
1,7-nonadiene, 7-ethyl-1,7-nonadiene, 5-methyl-1,4-decadiene, 5-ethyl-
1,4-decadiene, 5-methyl-1,5-decadiene, 6-methyl-1,5-decadiene, 5-ethyl-
1,5-decadiene, 6-ethyl-1,5-decadiene, 6-methyl-1,6-decadiene, 6-ethyl-
1,6-decadiene, 7-methyl-1,6-decadiene, 7-ethyl-1,6-decadiene, 7-methyl-
1,7-decadiene, 8-methyl-1,7-decadiene, 7-ethyl-1,7-decadiene, 8-ethyl-
1,7-decadiene, 8-methyl-1,8-decadiene, 9-methyl-1,8-decadiene, 8-ethyl-
1,8-decadiene, 6-methyl-1,6-undecadiene, 9-methyl-1,8-undecadiene, 6,10
-Dimethyl-1,5,9-undecatriene, 5,9-
Dimethyl-1,4,8-decatriene, 4-ethylidene-8-methyl-1,7-nonadiene, 13-ethyl-9
-Methyl-1,9,12-pentadecatriene, 5,
9,13-trimethyl-1,4,8,12-tetradecadiene, 8,14,16-trimethyl-1,7,14-
Hexadecatriene, 4-ethylidene-12-methyl-
1,11-pentadecadiene and the like can be mentioned.

As specific examples of the alicyclic non-conjugated polyene,
Vinylcyclohexene, 5-vinyl-2-norbornene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-isopropenyl-2-norbornene, cyclohexadiene, dicyclopentadiene,
Cyclooctadiene, 2,5-norbornadiene, 2-
Methyl-2,5-norbornadiene, 2-ethyl-2,
5-norbornadiene, 2,3-diisopropylidene-
5-norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, 6-chloromethyl-5-isopropylenyl-2-norbornene, 1,4-divinylcyclohexane, 1,3-divinylcyclohexane, 1,3
-Divinylcyclopentane, 1,5-divinylcyclooctane, 1-allyl-4-vinylcyclohexane, 1,
4-diallylcyclohexane, 1-allyl-5-vinylcyclooctane, 1,5-diallylcyclooctane, 1
-Allyl-4-isopropenylcyclohexane, 1-isopropenyl-4-vinylcyclohexane, 1-isopropenyl-3-vinylcyclopentane, methyltetrahydroindene and the like. Specific examples of the aromatic non-conjugated polyene include divinylbenzene and vinylisopropenylbenzene.

The above-mentioned olefin copolymer rubber is preferably ethylene-propylene copolymer rubber, ethylene-propylene-nonconjugated diene copolymer rubber, ethylene-propylene copolymer rubber.
1-butene-non-conjugated diene copolymer rubber or propylene-1-butene copolymer rubber.

In the present invention, an olefin copolymer rubber is preferable as a rubber used for producing a crosslinked type thermoplastic elastomer composition. Among them, an ethylene-propylene-non-conjugated diene copolymer rubber or an ethylene-propylene copolymer is preferable. Polymer rubbers are preferred. As the non-conjugated diene used here, dicyclopentadiene,
1,4-hexadiene, cyclooctadiene, 5-methylene-2-norbornene, or 5-ethylidene-2-
Norbornene is preferred, among which 5-ethylidene-2-
Norbornene is preferred. As the olefin copolymer rubber, the content of the unit derived from propylene is 10 to
55% by weight, more preferably 20 to 40% by weight, and the content of units derived from 5-ethylidene-2-norbornene is 1 to 30% by weight, more preferably 3 to 20% by weight. Ethylidene-2-norbornene copolymer rubber is particularly preferred (note that the total of units derived from each of ethylene, propylene and 5-ethylidene-2-norbornene contained in the copolymer is 100% by weight. select).

The method for producing the olefin copolymer rubber is not particularly limited, and it can be produced by a known method.
The catalyst used in the production is not particularly limited, and examples of the catalyst include a multi-site catalyst such as a conventional solid catalyst and a single-site catalyst exemplified by a catalyst using a metallocene complex. A commercially available rubber may be used as the olefin copolymer rubber.

100 ° C. of the above olefin copolymer rubber
Mooney viscosity (ML _{1 + 4} 100 ° C.) is preferably 30
３５０350, more preferably 120-350, most preferably 140-300.

The rubber or thermoplastic resin used in the present invention can be used in combination with a mineral oil-based softening agent, if necessary. As for the method of using the mineral oil-based softening agent, (i) a method of supplying only the mineral oil-based softening agent from any part of the extruder may be used, or (ii) a mineral oil-based softening agent and an olefin copolymer rubber may be used. May be used as an oil-extended olefin copolymer rubber obtained by mixing the above. 100 ° C Mooney Viscosity of olefin copolymer rubber (ML _{1 + 4} 10
0 ° C) is 30 to 80, the method (i) is preferred,
When the viscosity is 80 to 350, the method (ii) is preferred. When the viscosity is 80 to 170, the combination of (i) and (ii) is also preferably carried out.

In the present invention, when an oil-extended olefin copolymer rubber is used, the oil-extended olefin copolymer rubber is
Usually, 20 to 150 parts by weight, preferably 30 to 12 parts by weight of a mineral oil softener per 100 parts by weight of the olefin copolymer rubber.
It contains 0 parts by weight.

The above-mentioned "mineral oil-based softener" means a high-boiling-point petroleum fraction used for the purpose of improving the processability and mechanical properties of the obtained thermoplastic elastomer composition. Examples of the mineral oil-based softener include a paraffin-based fraction, a naphthenic-based fraction, and an aromatic-based fraction, and a paraffin-based fraction is preferred. A mineral oil-based softening agent having a high content of an aromatic component makes the obtained thermoplastic elastomer composition more contaminating, making it difficult to apply the obtained thermoplastic elastomer composition to a transparent product or a bright product. Or the light resistance of the obtained thermoplastic elastomer composition is deteriorated.

A process for producing an oil-extended olefin copolymer rubber,
That is, the method of mixing the mineral oil-based softener and the rubber is not particularly limited, and a known method can be used. Examples of the method include (i) a method of mechanically kneading an olefin copolymer rubber and a mineral oil-based softener using a kneading device exemplified by a roll or a Banbury mixer, and (ii) an olefin copolymer rubber. After adding a mineral oil-based softening agent to a solution consisting of a solvent and a solvent, a method of removing the solvent by a method exemplified by steam stripping can be exemplified. A preferred method for producing the oil-extended olefin copolymer rubber is the method (ii) above, wherein the olefin copolymer rubber obtained by producing the olefin copolymer rubber as a solution comprising the olefin copolymer rubber and a solvent is used. It is economical to use a solution.

The thermoplastic resin used in the present invention is a thermoplastic resin which can be formed into a thermoplastic elastomer composition by melt-kneading with rubber, and among them, an olefin polymer resin is preferable. The olefin polymer resin is a resin obtained by polymerizing an olefin, for example, ethylene homopolymer; α-olefin homopolymer such as propylene homopolymer; ethylene-α such as ethylene-1-butene copolymer. -Olefin copolymer; propylene-α-olefin copolymer such as propylene- (ethylene and / or 1-butene) copolymer; ethylene such as ethylene-vinyl acetate copolymer and ethylene-methyl methacrylate copolymer And the like.

Among these olefin polymer resins,
Propylene homopolymer and / or propylene-α-
A propylene-based resin having isotactic crystallinity, such as an olefin copolymer, is preferred. As the α-olefin referred to herein, for example, ethylene, 1-butene, 1-
Pentene, 3-methyl-1-butene, 1-hexene, 1
-Decene, 3-methyl-1-pentene, 4-methyl-1
-Pentene, 1-octene and the like. In the case of a propylene-α-olefin copolymer, a random copolymer and a block copolymer are generally known, and any of them can be used. According to JIS K6758, temperature 230
C., the melt flow rate of the propylene-based resin measured at a load of 21.18 N is preferably 0.1 to 100 g / 10
Min, more preferably in the range of 0.5 to 50 g / 10 min.

The method for producing the olefin polymer resin is not particularly limited, and may be a known production method. The catalyst used in the production is not particularly limited, and examples of the catalyst include a multi-site catalyst such as a conventional solid catalyst and a single-site catalyst exemplified by a catalyst obtained using a metallocene complex. A commercially available resin may be used as the olefin polymer resin.

In the present invention, one or more thermoplastic resins can be used as required.

In the present invention, the ratio of the rubber to the thermoplastic resin (rubber / thermoplastic resin, weight ratio) is preferably 20 to 95/80 to 5 for the production of the crosslinked thermoplastic elastomer composition. More preferably 35 to 9
0 / 65-10, most preferably 60-90 / 40-1
0. For the production of the non-crosslinked type thermoplastic elastomer composition, preferably 15 to 80/85 to 2
0, more preferably 15 to 50/85 to 50.
When the oil-extended olefin copolymer rubber is used, the usage ratio of the rubber means the usage ratio of the oil-extended olefin copolymer rubber.

The method for producing a thermoplastic elastomer composition of the present invention is a method for producing a thermoplastic elastomer composition in which the above rubber and thermoplastic resin are supplied to an extruder from separate supply ports and melt-kneaded. is there. The rubber used in the production method of the present invention is not particularly limited as long as it can be supplied from the supply port of the extruder, even if it is in the form of particles or block, but rubber is usually shipped in a veil form. The use of particulate rubber requires a manufacturing process and is complicated.Particulate cohesive rubber tends to adhere to each other in a hopper to form a large lump, and a quantitative supply of rubber is required. It is preferable to use a block-like rubber in the production method of the present invention because it is likely to be difficult.

The block rubber has a volume of 27c.
A block-like rubber of m ³ or more is preferred. Volume 27cm ³
Examples of the above-mentioned block-like rubber include rubber larger than a cube having a side of 3 cm, and include a veil-like rubber which is in a usual factory shipping shape, and a substantially rectangular parallelepiped shape obtained by cutting and dividing the same. The shape of the block rubber is not limited to a cube or a rectangular parallelepiped, and may be an irregular shape. Available block-shaped rubber is usually 100,000 c
The size of the block-shaped rubber is about ³ m or less, and even if the rubber with strong cohesiveness is cut finely, it will immediately adhere to each other, and small ones are difficult to handle. 100 to 100,000 cm ³ is preferable, 1000 to 70,000 cm ³ is more preferable, and 2
000-50,000 cm ³ is more preferred. In addition,
When such a block rubber is used, particulate rubber may be present as long as they adhere to each other in a hopper to form a large lump or the production and handling are not complicated. In addition,
For rubbers whose volume is difficult to measure, such as small block-shaped rubber or irregular-shaped block-shaped rubber, a method of submerging the rubber in a container filled with liquid such as water and measuring the volume of the liquid overflowing from the container is used. , The volume can be determined.

In the production method of the present invention, the supply amount of the rubber is controlled by separately supplying the rubber and the thermoplastic resin to the extruder. In the production method of the present invention, a block rubber is used as the rubber, and after the block rubber supplied to the extruder is crushed and / or softened by the extruder, the rubber and the thermoplastic resin are melt-kneaded. In particular, a method of softening the block rubber and then melt-kneading the rubber with a thermoplastic resin is more preferable. After the block rubber is crushed and / or softened by an extruder and then melt-kneaded with the thermoplastic resin, the block rubber is usually crushed and / or softened by an extruder, The rubber and the thermoplastic resin are melt-kneaded without being taken out.
"Without taking out of the system" means that the rubber is removed from a series of devices and is not once stored until the block-shaped rubber is supplied to the extruder and merges with the thermoplastic resin. .

In the production method of the present invention, the number of extruders used is not particularly limited, and one extruder may be used, or two or more extruders may be used. For example,
(1) a method in which a single extruder is used to supply a block-shaped rubber upstream thereof to crush and / or soften, and to supply a thermoplastic resin downstream thereof to join the two and melt-knead them ( 2) Using two extruders, the first extruder is supplied with block rubber to be crushed and / or softened, and the first extruder is connected to the upstream side of the second extruder, and connected. A method in which a thermoplastic resin is supplied to the downstream side of a location to mix and melt-knead them. (3) Three extruders are used, and a block-shaped rubber is supplied to a first extruder to crush and / or soften. Then, the thermoplastic resin is supplied to the second extruder to be melted, and the rubber and the thermoplastic resin are supplied from the extruder to the third extruder.
And extruders are combined to melt and knead them. Among them, it is preferable to use two extruders.

FIG. 1 is a drawing showing an example of the above method (2). In FIG. 1, 11 is a substantially rectangular block rubber, 12 is a first extruder, 13 is a second extruder, 1
Reference numerals 4 and 15 denote feed ports of each extruder, respectively. FIG.
In, the first extruder and the second extruder are connected in series. The block-like rubber 11 is supplied from the supply port 14 to the first extruder 12, and the rubber is crushed and / or softened, and the rubber is supplied to the second extruder 13 without being taken out of the system. Then, the thermoplastic resin is supplied to the supply port 15.
The extruder 13 is supplied to the extruder 13 to melt-knead the rubber and the thermoplastic resin, so that the non-crosslinked thermoplastic elastomer composition or the melt-kneading of the rubber and the thermoplastic resin can be performed. By cross-linking each other, a cross-linked type thermoplastic elastomer composition can be produced.

In FIG. 1, the first extruder 12
In order to quantitatively transfer the rubber to the extruder 13, a device such as a known gear pump or static mixer may be provided at the downstream end of the extruder 12.

When a block-shaped rubber is used in the production method of the present invention, an extruder in which the screw at the rubber supply point rotates in a different direction is used, and the block-shaped rubber is rotated in the different direction. It is preferable to use a method in which the screw is inserted into the gap between the screws. Here, the “screw at the rubber supply point” is, for example, a screw at a position below the supply port 14 in FIG.

FIG. 2 is a drawing showing an example of a screw and a barrel located below the supply port 14 in FIG. In FIG. 2, 16 and 17 are screw shafts, 18 and 19 are screw flights, respectively.
Reference numerals 20 and 21 denote barrels, respectively. Two screws, that is, a screw consisting of the shaft 16 and the flight 18 and a screw consisting of the shaft 17 and the flight 19,
Rotate in different directions. Then, the block-like rubber 11 is
By supplying the block-shaped rubber 11 to the gap between the screws, the block-shaped rubber 11 can be drawn in with the rotation of the screw, and the block-shaped rubber 11 can be stably supplied to the extruder 12.

As such an extruder, for example, a different-direction rotating twin-screw extruder or a twin-screw single-screw extruder can be mentioned. The twin-screw single-screw extruder is an extruder in which the upstream side of the extruder rotates in different directions and the downstream side of the extruder is single-axis.

Regarding the arrangement of the two screws of the screw of the counter-rotating twin-screw extruder and the twin-screw single-screw extruder, the screws may be arranged in parallel, or
As in the case of a skew type twin screw extruder, two screws may be arranged at oblique angles. Above all, from the viewpoint of stably supplying the block-like rubber, it is preferable that two screws are arranged in parallel.

Further, auxiliary equipment such as a pusher may be used as an auxiliary means for causing the block rubber to bite into the gap between the two screws. By pushing the block-shaped rubber into the gap between the two screws by the pusher, the block-shaped rubber can be supplied stably by the extruder.

In the present invention, when a substantially rectangular parallelepiped rubber typified by a veil, for example, is used as the block-like rubber, the block-like rubber is generally removed from the viewpoint of the stability of the block-like rubber biting into the gap between the two screws. It is preferable that at least one side of the three sides of the rectangular parallelepiped rubber is shorter than the distance between the axes of the two screws.

In FIG. 1, L₁, L_TwoAnd L_ThreeStands for
It is the length of three sides of the rectangular parallelepiped rubber 11. And two
The distance between the screw axes is the center of the two screw axes
This is the distance between_FourIs equivalent to
You. Length of at least one of the three sides of the substantially rectangular parallelepiped rubber
Is shorter than the distance between the axes of the two screws.₁, L
_Two And L_ThreeIs either L_FourIt is shorter.
That is, L₁<L_Four, L _Two<L_FourOr L_Three<L_FourNozomi
Anything is fine.

In the case of using an extruder in which the distance between the axes of the two screws is not uniquely determined (for example, a skew-type twin-screw extruder in which two screws are arranged diagonally),
As the distance between the axes of the two screws, the maximum value of the distance between the axes of the two screws of the block-shaped rubber supply unit is adopted,
It is preferable that at least one of the three sides of the substantially rectangular parallelepiped rubber has a length shorter than the maximum value.

In the present invention, when a substantially rectangular parallelepiped rubber is used as the block rubber, the three sides of the substantially rectangular parallelepiped rubber are taken into consideration from the viewpoint of the stability of the bite rubber being caught in the gap between the two screws. It is preferable that at least one side has a length shorter than the lead of the screw.

In FIG. 2, L_FiveIs the screw lead
Is shown. And, among the three sides of the substantially rectangular rubber,
If at least one side is shorter than the screw lead
Is L₁, L_Two And L_ThreeIs either L_FiveShorter
That is. That is, L₁<L _Five, L_Two<L_FiveOr L_Three
<L_FiveEither one is fine.

Further, when a substantially rectangular parallelepiped rubber is used as the block-shaped rubber, at least one of the three sides of the substantially rectangular parallelepiped rubber is shorter than the distance between the axes of the two screws. More preferably, the length of at least one other side of the rubber is shorter than the lead of the screw. When L ₁ , L ₂ and L ₃ in FIG. 1 have a relationship of L ₁ <L ₂ <L ₃ , for example, when L ₁ <L ₄ and L ₂ <L ₅ are satisfied, or L ₁ <L ₅ And L ₂ <L ₄ .

In the production method of the present invention, the thermoplastic resin can be supplied from the supply port to the extruder using a known supply device such as a belt feeder type or a screw feeder type. The number of thermoplastic resin supply points may be one, or two or more.

In the production method of the present invention, dynamic crosslinking can be carried out when melt-kneading the rubber and the thermoplastic resin. FIG. 3 is a drawing showing a preferred embodiment of a method for producing a crosslinked type thermoplastic elastomer composition by dynamically kneading an olefin copolymer rubber and an olefin polymer resin by melt-kneading. In FIG. 3, reference numeral 22 denotes a substantially rectangular parallelepiped olefin copolymer rubber; 23, a first extruder;
4 is a second extruder, 25, 26 and 27 are supply ports, 28 is a vent port for discharging volatile gas out of the extruder, 29 is an olefin copolymer rubber and an olefin polymer resin. The dispersing part 30 for kneading is a dynamic crosslinking part.

A substantially rectangular parallelepiped olefin copolymer rubber 22
Is supplied to the extruder 23 from the supply port 25, and is crushed and / or softened by the extruder 23, and the crushed and / or softened olefin copolymer rubber is supplied to the extruder 24. On the other hand, the olefin polymer resin is supplied from the supply port 26 to the extruder 24 using a known supply device such as a belt feeder type or a screw feeder type. Then, the olefin copolymer rubber and the olefin polymer resin are melt-kneaded in the dispersing section 29, and a crosslinking agent is supplied from the supply port 27,
Dynamic cross-linking is performed in the dynamic cross-linking section 30.

As the extruder 24, a single-screw extruder, a twin-screw extruder, or a multi-screw extruder having three or more screws equipped with a screw or a rotor having a kneading performance improving function can be used. As a design having improved kneading performance, a single screw extruder includes a dalmage, a pin, a multi-row flight, and a twin screw extruder includes a kneading disk, a rotor, and the like. As a commercially available extruder of this type, a single-screw extruder is Busconida (Buss), and a twin-screw extruder is ZSK (W & P), TEX (Japan Steel Works), TEM ( Toshiba Machine Co., Ltd.), KTX type (Kobe Steel), Mixtron L
CM type (Kobe Steel) and the like are exemplified. In the present invention, among these, a twin-screw extruder is preferable to a single-screw extruder from the viewpoint of productivity. Further, among the twin-screw extruders, those having the same-direction rotation are more preferable than those having the different-direction rotation, from the viewpoint that galling does not occur in long-term operation.

In one embodiment of the method for producing the thermoplastic elastomer composition of the present invention, a veil of an olefin copolymer rubber or a divided veil thereof is supplied to a supply unit having two screws, and the two screws Are rotated in different directions, and the distance between the axes of the two screws is supplied to a first extruder that is longer than at least one of three sides of a bale of the olefin copolymer rubber or a part thereof. The first extruder softens the olefin copolymer rubber, feeds the olefin copolymer rubber from the first extruder to another extruder, and supplies the olefin copolymer rubber and the olefin copolymer rubber with the other extruder. A method for producing a thermoplastic elastomer composition that dynamically crosslinks an olefin polymer resin is preferred. Further, the first extruder may be arranged such that, from three sides of the bale of olefin copolymer rubber or a part obtained by dividing the bale, the first extruder is shorter than the distance between the axes of the two screws in the supply section of the first extruder.
It is preferable that the extruder has a longer screw lead than at least one of the two sides excluding the sides.

As the crosslinking agent used for dynamically crosslinking, those capable of crosslinking rubber are preferably used. For example, an organic peroxide, sulfur, a phenol resin, or the like can be used. Among them, organic peroxides are preferred.

Although the supply location of the crosslinking agent is not particularly limited, as shown in FIG. 3, the olefin copolymer rubber and the olefin polymer resin are first melt-kneaded in the dispersing section 29 of the extruder 24, and thereafter, , A cross-linking agent is supplied from the supply port 27,
It is preferable that the olefin copolymer rubber and the olefin polymer resin are dynamically crosslinked in the dynamic crosslink section 30, and is particularly suitable when an organic peroxide is used as a crosslinking agent.

When a crosslinking agent having a slow crosslinking rate is used, the olefin copolymer rubber, the olefin polymer resin and the crosslinking agent are first melt-kneaded in the dispersing section 29 of the extruder 24, In step 30, a method of dynamically crosslinking by adding a crosslinking accelerator can also be used, and is particularly preferable when a methylphenol-based curing agent resin is used as a crosslinking agent and stannous chloride is used as a crosslinking accelerator.

The crosslinking agent used in the present invention may be in the form of a liquid or a powder, and is preferably a liquid crosslinking agent. From the viewpoint of obtaining an excellent thermoplastic elastomer composition, it is very important to improve the dispersibility of the crosslinking agent. In order to improve the dispersibility of the crosslinking agent,
It is preferable to use in combination with a diluent exemplified by an inorganic filler inert to the crosslinking reaction, a mineral oil and a solvent. Paraffin-based oils are preferred diluents in view of the ease of handling the diluent and the fact that the diluent does not substantially affect the obtained thermoplastic elastomer composition. The cross-linking agent can be supplied to the extruder by using a metering pump when it is in a liquid state, or by using a metering feeder when it is in a powder state.

As a crosslinking agent for an organic peroxide, for example,
2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3,1,3-bis (t- Butylperoxyisopropyl) benzene, 1,1-di (t-butylperoxy) 3,5,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di (peroxybenzoyl) hexyne-3, dicumyl Peroxide or the like can be used. Among them, 2,5-dimethyl-2,5-di (t-
Butylperoxy) hexane is preferred.

The amount of the crosslinking agent to be added is selected in the range of usually 0.005 to 5 parts by weight, preferably 0.01 to 4 parts by weight, based on 100 parts by weight of the total of the rubber and the thermoplastic resin.
If the amount is less than 0.005 parts by weight, the effect of the crosslinking reaction may be small, and if it exceeds 5 parts by weight, control of the reaction may be difficult, and it is not economically advantageous.

The organic peroxide may be used in combination with a crosslinking aid. It is preferable that the cross-linking aid is supplied to the extruder at a position upstream of the cross-linking agent supply or at the same position as the cross-linking agent supply. As a crosslinking aid,
N, N'-m-phenylenebismaleimide, toluylenebismaleimide, p-quinonedioxime, nitrobenzene, diphenylguanidine, trimethylolpropane,
Examples include divinylbenzene, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, and allyl methacrylate. By using a cross-linking agent in combination with a cross-linking aid, a uniform and mild cross-linking reaction can be advanced, and as a result, the mechanical properties of the obtained thermoplastic elastomer can be improved.

The amount of the crosslinking aid is usually 0.01 to 4 parts by weight based on 100 parts by weight of the total of the rubber and the thermoplastic resin.
Preferably it is 0.05 to 2 parts by weight. If the amount is less than 0.01 part by weight, the effect is unlikely to be exhibited, and if it exceeds 4 parts by weight, it is not economically advantageous.

The dispersing section 29 and the dynamic cross-linking section 30 preferably have a screw or a rotor designed to have a kneading performance improving function. When a twin-screw extruder is used, for example, as the dispersing section 29 and the dynamic cross-linking section 30, discs exemplified by progressive kneading discs, reverse kneading discs, and orthogonal kneading discs can be used in combination.

The temperature of the dispersion section 29 is a temperature at which at least the thermoplastic resin can be melted. If this temperature is too high, it is difficult to control the next step of dynamic crosslinking, so it is desirable that the temperature be as low as possible. For example, when polypropylene is used as the thermoplastic resin, the temperature is preferably 140 to 250 ° C.

The rubber is preferably transferred to the extruder 24 in a softened state. The temperature of the rubber at the time of transfer to the extruder 24 is preferably from 80 to 200 ° C., more preferably from 120 to 180 ° C. ° C. If the temperature is lower than 80 ° C., the rubber is not sufficiently softened, so that it is difficult to stably transfer the rubber to the extruder 24. Conversely, if this temperature is 200
When the temperature exceeds ℃, the rubber and the thermoplastic resin may not be sufficiently kneaded in the extruder 24, or it may be difficult to control the next step of dynamic crosslinking.

Maximum shear rate in the dynamically crosslinked part 30
Is 500 seconds^-1~ 2000sec ^-1Less than preferred
1000 seconds^-1~ 1900 sec^-1Is more preferred
No. The maximum shear rate is the maximum between the barrel and the screw.
Calculated from small gap, barrel inner diameter and screw rotation speed
Value.

The set temperature of the dynamic cross-linking section 30 depends on the type of the cross-linking agent used. However, when an organic peroxide is used as the cross-linking agent, the organic peroxide is supplied to the outlet of the extruder 24 (FIG. From the viewpoint that it is important that it is almost completely consumed at the right end part),
More preferably, it is 150 to 300 ° C. The preferred temperature range of the kneaded material in the dynamic cross-linking section 30 is 180 to
The temperature is 290 ° C, more preferably 200 to 280 ° C.
When the temperature of the kneaded material is close to 300 ° C., decomposition, deterioration or excessive crosslinking reaction of the kneaded material due to heat is apt to occur, and as a result, coloring of the obtained thermoplastic elastomer and poor appearance are caused.

The residence time of the kneaded material in the dynamic cross-linking section 30 depends on the size of the extruder 24, the temperature of the dynamic cross-linking section 30, the used reactant, and the like, but is preferably at least 10 seconds or more and less than 3 minutes. .

An additional thermoplastic resin may be added after the dynamic crosslinking.

In the present invention, if necessary, an inorganic filler, an antioxidant, a weathering agent, an antistatic agent, a lubricant, a coloring pigment and the like can be added. In the case of producing a crosslinked type thermoplastic elastomer composition, it may be supplied from any part of the extruder used as long as the crosslinking reaction is not hindered.

In the present invention, a crosslinked or non-crosslinked thermoplastic elastomer composition can be obtained in the form of pellets by using known means such as underwater cut, cold cut and hot cut.

The pellet-like thermoplastic elastomer composition may have an antiadhesion agent attached to the surface of the pellet, if necessary. Talc,
Examples include inorganic powders exemplified by calcium carbonate and silica and powders exemplified by olefin polymer resins, and powders made of ethylene polymer resins are preferred.

The thermoplastic elastomer composition of the present invention is a thermoplastic elastomer composition having excellent fogging resistance, and was measured at a heating temperature of 100 ° C. using a device conforming to ISO 6452, and 20 hours after heating. It is a thermoplastic elastomer composition in which the haze of a glass plate is 2% or less. In the present invention, a glass plate having a haze value of 0.5% or less before a fogging test is used.

The thermoplastic elastomer composition having a haze of 2% or less as measured by the above method is suitable for automobile interior parts, particularly for instrument panels. The thermoplastic elastomer composition of the present invention having excellent fogging resistance is preferably a thermoplastic elastomer composition obtained by melt-kneading a rubber and a thermoplastic resin. A copolymer rubber is preferable, and the above-mentioned olefin polymer resin is preferable as the thermoplastic resin. The thermoplastic elastomer composition of the present invention is produced by the above-described method for producing the thermoplastic elastomer composition of the present invention.

[0071]

Hereinafter, the present invention will be described based on examples.
The present invention is not limited to these examples.

The fogging resistance is represented by a haze value of a glass plate subjected to a fogging test using an apparatus according to ISO6452, and the haze value was measured according to JIS K7105. Here, ISO stands for International
nal Organization for Stand
ardification (International Organization for Standardization)
The apparatus shown in FIG. 4 was used as an apparatus conforming to the standard of SO6452. In FIG. 4, 31 is an oil bath, 32 is oil, 33 is a glass plate, 34 is a cooling plate with temperature control, 35 is a beaker with an inner diameter of 90 mmφ, and 36 is a ring packing made of silicon rubber. The clearance between the inner wall of the oil bath 31 and the outer wall of the beaker 35 is 40 m.
m. On the other hand, 37 is a sample, and 38 and 39 are chrome-plated metal rings. The haze value of the glass plate 33 before the fogging test was 0.3%.

In the measurement of fogging resistance, the temperature of the oil bath 31 was adjusted to 100 ± 2 ° C., the temperature of the cooling plate 34 was adjusted to 20 ± 2 ° C., and the sample 37 was 80 mmφ × 1 mmt.
And After heating the sample 37 in the beaker 35 for 20 hours and taking it out, the haze value of the glass plate 33 was determined by JISK after 1 ± 0.1 hour in an environment of 23 ± 2 ° C. and 50% RH.
The measurement was performed in accordance with 7105, and this value was regarded as fogging resistance.

FIG. 5 shows an apparatus configuration diagram used in the embodiment. In FIG. 5, 40 is about 130 mm × about 150 m
mx about 330 mm oil-extended ethylene-propylene-5-ethylidene-2-norbornene copolymer rubber in a substantially rectangular parallelepiped shape, 41 is a supply port, 42 and 43 are extruders, respectively.
44 and 45 are supply ports respectively, 46 is a vent port for discharging the volatile gas out of the extruder 43, 47, 48,
Reference numerals 49 and 50 indicate zones using the kneading disk. Here, the zone 47 is a dispersion part, and the zones 48 to 50 are dynamic bridge parts.

Next, the configuration and operating conditions of the extruders 42 and 43 will be described. (1) Extruder 42: barrel diameter = 230 mm, L / D =
5. This is a different-direction rotating twin-screw extruder with the number of cylinder blocks = 2 and the distance between screw axes = 207 mm. In the following, each cylinder block is connected to C1 and C from the upstream side of the extruder 42.
Let it be 2. A supply port 41 for supplying rubber was provided at C1, and the lead of the screw below the supply port 41 was 287.5 mm. A pusher (not shown) is provided as an auxiliary means for supplying rubber to the extruder. Screw rotation speed is 13.5
rpm, cylinder set temperature is C1 / C2 = 170 ° C /
170 ° C.

(2) Extruder 43: barrel diameter = 120 m
This is a co-rotating twin-screw extruder with m, L / D = 42 and the number of cylinder blocks = 12. Hereinafter, each cylinder block is placed in the order of C1, C2, C3,.
.., C10, C11, C12, and the die part is D
And A supply port 44 for supplying a thermoplastic resin and various additives is provided at C2, and a supply port 45 for supplying a crosslinking agent is provided at C6. Screw rotation speed is 12
0 rpm, the set temperature of the cylinder and the die part is C1
/ C2 / C3 / C4 / C5 / C6 / C7 / C8 / C9 /
C10 / C11 / C12 / D = 160/160/160
/ 140/140/140/160/180/200 /
200/160/160/240 ° C.

A bale-shaped oil-extended ethylene-propylene-5-ethylidene-2-norbornene copolymer rubber having a size of about 150 mm × about 660 mm × about 330 mm and a weight of 25 kg (manufactured by Sumitomo Chemical Co., Ltd .; trade name) Esplen 670F) is divided into 5 parts by a cutting machine,
An approximately rectangular parallelepiped block rubber 40 of about 150 mm × about 330 mm was obtained. Next, this is supplied to the extruder 4 through the supply port 41.
2 and softened, and the softened rubber is
The feed was 30 kg / hr.

On the other hand, from the supply port 44, polypyrropyrene (manufactured by Sumitomo Chemical Co., Ltd .; trade name: Noblen Y501)
N, MFR (according to JIS K6758, temperature 230 ° C,
Value measured under a load of 21.18 N) = 13 g / 10 min),
And the additive mixture were each fed to an extruder 43 through a metering feeder. The supply amount is 8 for polypropylene
6.4 kg / hr, additive mixture is 7.48 kg / hr
Met. Here, the additive mixture is a crosslinking aid (Sumitomo Chemical Co., Ltd .; trade name Sumifine BM) / antioxidant (Sumitomo Chemical Co., Ltd .; trade name Sumilyzer BP101) = 0. The mixture was a 9 / 0.25 weight ratio.

Then, in zone 47 using a kneading disk, oil-extended ethylene-propylene-5-ethylidene-2-norbornene copolymer rubber, polypropylene,
The additive mixture was kneaded.

Further, 10% by weight of 2,5-dimethyl-2,5-di (t-butylperoxy) hexane was added to mineral oil-based oil (manufactured by Idemitsu Kosan; trade name: Diana Process Oil PW380) from the supply port 45. Was supplied to the extruder 43 at 20.9 kg / hr using a plunger pump.

Then, the kneading disk zone 4
At 8, 49 and 50, dynamic crosslinking was performed. Pellets were formed using an underwater cutter to obtain pellets of the olefin-based thermoplastic elastomer composition.

The obtained pellet was pressed for 2 minutes by a press machine controlled at 200 ° C. to obtain a sheet having a thickness of 1 mm.
The pressure of the press was 10 MPa. Then, the obtained sheet was cut out to obtain a sample of 80 mmφ × 1 mm, and the fogging resistance was evaluated. As a result, the haze value of the glass plate was 0.4%.

[0083]

As described above in detail, according to the present invention, in a method for producing a thermoplastic elastomer composition by melting and kneading rubber and a thermoplastic resin, a method for producing a thermoplastic elastomer composition is described. Even when using strong rubber, the rubber can be stably supplied to the extruder, and it is economical.
A method for producing a thermoplastic elastomer composition having a uniform composition ratio is provided. Furthermore, by using a block-shaped rubber as the rubber, the rubber can be more stably supplied to the extruder, and a method for easily producing a thermoplastic elastomer composition having a uniform composition ratio is provided. According to the present invention,
Provided is a thermoplastic elastomer composition having excellent fogging resistance required for automotive interior parts such as instrument panels (dashboards).

[Brief description of the drawings]

FIG. 1 is a drawing showing an example of an embodiment of the present invention,
It is drawing which shows an example which manufactures a thermoplastic elastomer composition using a single extruder.

FIG. 2 is a drawing showing an example of a screw and a barrel located below a supply port 14 of the extruder of FIG.

FIG. 3 is a view showing an example of an embodiment of the present invention, in which an olefin copolymer rubber and an olefin polymer resin are melt-kneaded and dynamically crosslinked to produce a crosslinked type thermoplastic elastomer composition. 1 is a drawing showing a preferred embodiment of a method for performing the method.

FIG. 4 is a cross-sectional view of a fogging haze measuring device according to ISO 6452.

FIG. 5 is a diagram showing a device configuration used in an embodiment of the present invention.

[Explanation of symbols]

L ₁ , L ₂ , L ₃ ... length of one side of substantially rectangular parallelepiped rubber L ₄ ... distance between the axes of two screws L ₅ ... screw leads 11, 22, 40 Extruder 14, 15, 25, 26, 27, 41, 44, 45,... Extruder 14, 13, 23, 24, 42, 43
・ Supply port 16, 17 ・ ・ ・ Screw shaft 18,19 ・ ・ ・ Screw flight 20,21 ・ ・ ・ Barrel 28,46 ・ ・ ・ Vent port 29,47 ・ ・ ・ Dispersion part 30,48,49 、 50 ... Dynamic bridge part 31 ... Oil bath 32 ... Oil 33 ... Glass plate 34 ... Cooling plate with temperature control 35 ... Beaker 36 ... Silicon rubber annular packing 37 ... ..Samples 38, 39 ... metal rings

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 23/00 C08L 23/00 101/00 101/00 // B29K 21:00 23:00

Claims (15)

[Claims] 1. A method for producing a thermoplastic elastomer composition in which rubber and a thermoplastic resin are supplied to an extruder from separate supply ports and melt-kneaded. 2. The method for producing a thermoplastic elastomer composition according to claim 1, wherein the rubber is a block rubber having a volume of 27 cm ³ or more. 3. The process for producing a thermoplastic elastomer composition according to claim 2, wherein the block rubber supplied to the extruder is crushed and / or softened and then melt-kneaded with a thermoplastic resin. 4. The thermoplastic elastomer composition according to claim 2, wherein the block rubber is supplied to an extruder by biting the block rubber into a gap between two screws rotating in different directions. Method. 5. The block-shaped rubber is a substantially rectangular parallelepiped rubber, and at least one of three sides of the substantially rectangular parallelepiped rubber is shorter than a distance between two screws. Item 5. The method for producing a thermoplastic elastomer composition according to Item 4. 6. The block-shaped rubber is a substantially rectangular parallelepiped rubber, and at least one of three sides of the substantially rectangular parallelepiped rubber is shorter than a screw lead. A method for producing a thermoplastic elastomer composition according to the above. 7. The method for producing a thermoplastic elastomer composition according to claim 1, wherein the melt-kneading is a melt-kneading for dynamically crosslinking while performing the melt-kneading. 8. The method for producing a thermoplastic elastomer composition according to claim 1, wherein the rubber is an olefin copolymer rubber. 9. The method for producing a thermoplastic elastomer composition according to claim 1, wherein the thermoplastic resin is an olefin polymer resin. 10. A thermoplastic elastomer composition produced by the method for producing a thermoplastic elastomer composition according to claim 1. 11. A thermoplastic elastomer composition wherein the haze of a glass plate measured after heating for 20 hours at a heating temperature of 100 ° C. using an apparatus conforming to ISO 6452 is 2% or less. 12. The thermoplastic elastomer composition according to claim 11, wherein the thermoplastic elastomer composition is a thermoplastic elastomer composition obtained by melt-kneading a rubber and a thermoplastic resin. 13. The thermoplastic elastomer composition according to claim 12, wherein the rubber is an olefin copolymer rubber. 14. The thermoplastic elastomer composition according to claim 12, wherein the thermoplastic resin is an olefin polymer resin. 15. An automotive interior part comprising the thermoplastic elastomer composition according to claim 10.