Thermoplastic elastomer composition and molded products using the same

1. A thermoplastic elastomer composition obtained by crosslinking a composition comprising components (A) to (D) below:

(A) 100 parts by mass of a polypropylene-based resin,

(B) from 80 to 200 parts by mass of a hydrogenated product of a block copolymer having at least one block mainly including a conjugated diene monomer unit and at least one block mainly including a vinyl aromatic monomer unit,

(C) from 100 to 250 parts by mass of a softening agent, and

(D) from 5 to 20 parts by mass of polyorganosiloxane, the thermoplastic elastomer composition satisfying conditions (1) to (7) below:

(1) a content of the vinyl aromatic monomer unit in the component (B) is from 30 to 80% by mass,

(2) a melt flow rate (MFR) measured according to ASTM D1238 at 230° C. with load of 1.2 kg is from 35 to 85 g/10 min,

(3) a Japanese Industrial Standard (JIS) A hardness is from 60 to 90,

(4) a compression set measured according to JIS K6262 at 100° C. for 22 hours is from 30 to 70%,

(5) a tensile elongation at −30° C. is not less than 80%,

(6) a melt viscosity at a shear rate of 100/sec measured by a capillary rheometer is from 30 to 200 Pa·sec, and

(7) a melt viscosity at a shear rate of 1000/sec measured by a capillary rheometer is from 10 to 40 Pa·sec,

wherein as a measurement condition of the melt viscosity measured by a capillary rheometer on the conditions (6) and (7), heating temperature is 230° C., cylinder diameter is 9.55 mm, orifice diameter is 1.0 mmφ, and orifice length is 10 mm.

2. The thermoplastic elastomer composition according to claim 1 , wherein at least one tan δ peak temperature of the thermoplastic elastomer composition measured by dynamic viscoelastic analysis exits in the range of −25 to 40° C.

3. The thermoplastic elastomer composition according to claim 1 , wherein the component (A) in the thermoplastic elastomer composition obtained by crosslinking has a weight average molecular weight, measured by gel permeation chromatography (GPC) using o-dichlorobenzene as a solvent, in the range of 5.0×10 4 to 2.0×10 5 in terms of polystyrene.

4. The thermoplastic elastomer composition according to claim 1 , wherein the component (D) has a kinematic viscosity at 25° C. specified in JIS Z8803 of not less than 5000 cSt.

5. The thermoplastic elastomer composition according to claim 1 , wherein the block mainly including a conjugated diene monomer unit in the component (B) is a copolymer block mainly including a conjugated diene monomer unit and including a vinyl aromatic monomer unit.

6. The thermoplastic elastomer composition according to claim 1 , further comprising from 40 to 80 parts by mass of an ethylene.α-olefin-based copolymer including an ethylene unit and a unit of α-olefin having 3 to 20 carbon atoms.

7. An injection molded product, comprising the thermoplastic elastomer composition according to claim 1 .

8. A sheet comprising the injection molded product according to claim 7 .

9. An automobile interior material comprising the injection molded product according to claim 7 .

10. The automobile interior material according to claim 9 , wherein an average thickness is not more than 2 mm, and a surface area is not less than 1000 cm 2 .

11. A laminate, comprising a layer including the automobile interior material according to claim 9 , and

a layer including a core material, laminated on the layer including the automobile interior material, wherein

the core material is at least one selected from the group consisting of polypropylene, acrylonitrile.butadiene.styrene (ABS) resin, polycarbonate/acrylonitrile.butadiene.styrene alloy (PC/ABS alloy), and modified polyphenylene ether resin.

12. The laminate according to claim 11 , further comprising a layer including a foaming material provided between the layer including the automobile interior material and the layer including a core material.

13. An instrument panel, comprising the laminate according to claim 11 .

14. The thermoplastic elastomer composition according to claim 1 , wherein the thermoplastic elastomer composition comprises from 90 to 170 parts by mass of the hydrogenated product of a block copolymer.

15. The thermoplastic elastomer composition according to claim 1 , wherein the thermoplastic elastomer composition comprises from 150 to 200 parts by mass of the softening agent.

16. The thermoplastic elastomer composition according to claim 1 , wherein the thermoplastic elastomer composition comprises from 8 to 15 parts by mass of said polyorganosiloxane.

17. A thermoplastic elastomer composition obtained by crosslinking a composition comprising components (A) to (D) below:

(A) 100 parts by mass of a polypropylene-based resin,

(B) from 80 to 200 parts by mass of a hydrogenated product of a block copolymer having at least one block mainly including a conjugated diene monomer unit and at least one block mainly including a vinyl aromatic monomer unit,

(C) from 100 to 250 parts by mass of a softening agent, and

(D) from 5 to 20 parts by mass of polyorganosiloxane,

the thermoplastic elastomer composition satisfying conditions (1) to (6) below:

(1) a content of the vinyl aromatic monomer unit in the component (B) is from 30 to 80% by mass,

(2) a melt flow rate (MFR) measured according to ASTM D1238 at 230° C. with load of 1.2 kg is from 35 to 85 g/10 min,

(3) a Japanese Industrial Standard (JIS) A hardness is from 60 to 90,

(4) a compression set measured according to JIS K6262 at 100° C. for 22 hours is from 30 to 70%,

(5) a tensile elongation at −30° C. is not less than 80%, and

(6) a melt viscosity at a shear rate of 100/sec measured by a capillary rheometer is from 30 to 200 Pa·sec, wherein as a measurement condition of the melt viscosity measured by a capillary rheometer, a heating temperature is 230° C., a cylinder diameter is 9.55 mm, an orifice diameter is 1.0 mmφ, and an orifice length is 10 mm.

18. A thermoplastic elastomer composition obtained by crosslinking a composition comprising components (A) to (D) below:

(A) 100 parts by mass of a polypropylene-based resin,

(B) from 80 to 200 parts by mass of a hydrogenated product of a block copolymer having at least one block mainly including a conjugated diene monomer unit and at least one block mainly including a vinyl aromatic monomer unit,

(C) from 100 to 250 parts by mass of a softening agent, and

(D) from 5 to 20 parts by mass of polyorganosiloxane,

the thermoplastic elastomer composition satisfying conditions (1) to (6) below:

(1) a content of the vinyl aromatic monomer unit in the component (B) is from 30 to 80% by mass,

(2) a melt flow rate (MFR) measured according to ASTM D1238 at 230° C. with load of 1.2 kg is from 35 to 85 g/10 min,

(3) a Japanese Industrial Standard (JIS) A hardness is from 60 to 90,

(4) a compression set measured according to JIS K6262 at 100° C. for 22 hours is from 30 to 70%,

(5) a tensile elongation at −30° C. is not less than 80%, and

(6) a melt viscosity at a shear rate of 1000/sec measured by a capillary rheometer is from 10 to 40 Pa·sec, wherein as a measurement condition of the melt viscosity measured by a capillary rheometer, a heating temperature is 230° C., a cylinder diameter is 9.55 mm, an orifice diameter is 1.0 mmφ, and an orifice length is 10 mm.