IMPACT ABSORBER COMPOSITION

• US 20100068452A1
• Filed: 02/19/2008
• Published: 03/18/2010
• Est. Priority Date: 02/20/2007
• Status: Active Grant

• Current Assignee: Asahi Kasei Chemicals Corporation (Asahi Kasei Corporation)
• Original Assignee: Asahi Kasei Chemicals Corporation (Asahi Kasei Corporation)
• Inventors: Araki, Yoshifumi, Kusanose, Yasuhiro
• Granted Patent: US 8,541,504 B2
• Time in Patent Office: Days
• US Class Current: 428/106
• CPC Class Codes: A43B 13/187 Resiliency achieved by the features of the material, e.g. foam, non liquid materials
• CPC Class Codes: B32B 21/08 of synthetic resin
• CPC Class Codes: B32B 2270/00 Resin or rubber layer containing a blend of at least two different polymers
• CPC Class Codes: B32B 2274/00 Thermoplastic elastomer material thermoplastic elastomer fibres B32B2262/0215, thermoplastic elastomer particles B32B2264/0221, thermoplastic elastomer foam B32B2266/0292
• CPC Class Codes: B32B 2307/56 Damping, energy absorption
• CPC Class Codes: B32B 2419/00 Buildings or parts thereof walls, panels B32B2607/00
• CPC Class Codes: B32B 2437/02 Gloves, shoes
• CPC Class Codes: B32B 2605/00 Vehicles
• CPC Class Codes: B32B 27/20 using fillers, pigments, thixotroping agents
• CPC Class Codes: B32B 27/30 comprising vinyl (co)polymers; comprising acrylic (co)polymers
• CPC Class Codes: B32B 27/32 comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: B32B 5/18 characterised by features of a layer of foamed material
• CPC Class Codes: C08F 297/04 polymerising vinyl aromatic monomers and conjugated dienes
• CPC Class Codes: C08J 2201/024 Preparation or use of a blowing agent concentrate, i.e. masterbatch in a foamable composition
• CPC Class Codes: C08J 2203/04 N2 releasing, ex azodicarbonamide or nitroso compound
• CPC Class Codes: C08J 2353/02 of vinyl aromatic monomers and conjugated dienes
• CPC Class Codes: C08J 2423/00 Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers
• CPC Class Codes: C08J 9/0061 characterized by the use of several polymeric components
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 2666/04 Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
• CPC Class Codes: C08L 53/02 : of vinyl-aromatic monomers and conjugated dienes
• CPC Class Codes: C08L 53/025 : modified
• CPC Class Codes: Y10T 428/24066 : Wood grain

Abstract

Provided in this invention is an impact absorber composition comprising a copolymer containing an aromatic vinyl compound, wherein the peak of tan δ of the copolymer obtained from the measurement of the dynamic viscoelasticity is in the range of more than 0° C. to 20° C. or less, the value of tan δ is 0.4 or more in the whole temperature range of 5° C. to 15° C., and the value of tan δ at 15° C. is 0.5 or more.

Claims

1. An impact absorber composition comprising a copolymer containing an aromatic vinyl compound, wherein a tan δ

peak determined from a measurement of dynamic viscoelasticity (at 1 Hz) of the copolymer is in a range from more than 0°

C. to 20°

C. or less, a tan δ

value of the copolymer is 0.4 or more in a whole temperature range of 5°

C. to 15°

C., and the tan δ

value of the copolymer at 15°

C. is 0.5 or more.

2. The impact absorber composition according to claim 1, wherein the copolymer containing the aromatic vinyl compound is a copolymer (which may have been hydrogenated) composed principally of an aromatic vinyl compound and a conjugated diene, and/or a copolymer composed principally of an aromatic vinyl compound and alkylene.

3. The impact absorber composition according to claim 1 or 2, wherein the tan δ

peak determined from the measurement of dynamic viscoelasticity (at 1 Hz) of the copolymer containing the aromatic vinyl compound is in a range of 2°

C. to 15°

C., and the tan δ

value of the copolymer at 15°

C. is 0.55 or more.

4. The impact absorber composition according to claim 1 or 2, wherein the tan δ

value determined from the measurement of dynamic viscoelasticity (at 1 Hz) of the copolymer containing the aromatic vinyl compound is 0.5 or more in the whole temperature range of 5°

C. to 15°

C.

5. The impact absorber composition according to claim 1 or 2, wherein a modulus of rigidity G′

at −

5°

C. determined from the measurement of dynamic viscoelasticity (at 1 Hz) of the copolymer containing the aromatic vinyl compound is 500 MPa or less, and the modulus of rigidity G′

at 40°

C. is 4 MPa or less.

6. The impact absorber composition according to claim 2, wherein a ratio of hydrogenation to the double bonds based on a pre-hydrogenation conjugated diene compound in the copolymer containing the aromatic vinyl compound is 5% or more to 97% or less.

7. The impact absorber composition according to claim 2, wherein the ratio of hydrogenation to the double bonds based on the pre-hydrogenation conjugated diene compound in the copolymer containing the aromatic vinyl compound is 10% or more to 70% or less.

8. The impact absorber composition according to claim 1 or 2, wherein a weight-average molecular weight of the copolymer containing the aromatic vinyl compound is 50,000 or more to 500,000 or less.

9. The impact absorber composition according to claim 1 or 2, wherein the copolymer containing the aromatic vinyl compound comprises at least a copolymer block composed principally of alkylene and an aromatic vinyl compound, and/or a copolymer block (S) composed principally of a conjugated diene and an aromatic vinyl compound.

10. The impact absorber composition according to claim 9, wherein a content of vinyl derived from the pre-hydrogenation conjugated diene in the copolymer block (S), or an amount of α

-olefin having 3 or more carbon atoms derived from alkylene is in a range of 5% or more to 60% or less.

11. The impact absorber composition according to claim 9, wherein the copolymer block (S) comprises a copolymer composed principally of a conjugated diene and an aromatic vinyl compound and has two or more segments differing in content of the aromatic vinyl compound, and a difference in content of the aromatic vinyl compound between any two segments is 5% by weight or more.

12. The impact absorber composition according to claim 11, wherein the copolymer block (S) contains two adjoining segments differing in content of aromatic vinyl compound by 5% by weight or more.

13. The impact absorber composition according to claim 11 or 12, wherein the segments differing in the content of the aromatic vinyl compound comprise a segment (S1) of a monomeric composition having an aromatic vinyl compound content of 25 to 55% by weight, and a segment (S2) of a monomeric composition having an aromatic vinyl compound content of 55 to 80% by weight, and amounts of the segments 51 and S2 are each 30% by weight or more based on the copolymer block (S).

14. The impact absorber composition according to claim 1 or 2, wherein a content of the aromatic vinyl compound in the copolymer containing the aromatic vinyl compound is more than 50% by weight.

18. The impact absorber composition according to claim 1 or 2, which comprises the copolymer containing the aromatic vinyl compound and a thermoplastic resin other than the copolymer containing the aromatic vinyl compound, wherein a ratio by weight of the copolymer containing the aromatic vinyl compound to the thermoplastic resin is 95/5 to 5/95.

19. The impact absorber composition according to claim 18, wherein the thermoplastic resin is a copolymer containing ethylene.

20. The impact absorber composition according to claim 19, comprising the copolymer containing the aromatic vinyl compound, a thermoplastic resin containing 50% by weight or more of ethylene or an olefinic thermoplastic elastomer, and an inorganic filler.

21. The impact absorber composition according to claim 1 or 2, further comprising a foaming agent.

22. The impact absorber composition according to claim 1 or 2, further comprising a crosslinking agent.

23. The impact absorber composition according to claim 1 or 2, which has a specific gravity of 0.28 or more to 0.35 or less, a hardness at 22°

C. of 47°

or more to 53°

or less, an impact resilience of 14% or less, and a peel strength of 27 N/cm or more.

24. A footwear using the impact absorber composition according to claim 1 or 2.

25. A laminate obtained by laminating the impact absorber composition according to claim 1 or 2 and a plywood.

15. A process for producing a copolymer containing an aromatic vinyl compound by anionic polymerization, which comprises:

a step of polymerizing a copolymer block (S) composed principally of an aromatic vinyl compound and a conjugated diene,

wherein the step of polymerizing the copolymer block (S) is carried out by supplying the aromatic vinyl compound and the conjugated diene to a polymerization tank for polymerization by changing a ratio of the aromatic vinyl compound to the conjugated diene, or by portioning a monomeric mixture differing in a ratio of the aromatic vinyl compound to the conjugated diene in two or more stages.

16. The process for producing a copolymer containing an aromatic vinyl compound according to claim 15, wherein the step of polymerizing the copolymer block (S) comprises a step of supplying the aromatic vinyl compound and the conjugated diene to a polymerization tank as a monomeric mixture (M1) having the aromatic vinyl compound content of 25 to 55% by weight for polymerization, and a step of supplying the aromatic vinyl compound and the conjugated diene to a polymerization tank as a monomeric mixture (M2) which differs in composition from the M1 and has an aromatic vinyl compound content of 55 to 80% by weight for polymerization.

17. The process for producing a copolymer containing an aromatic vinyl compound according to claim 16, wherein a difference in the aromatic vinyl compound content between the monomeric mixture (M1) and the monomeric mixture (M2) is 5 by weight or more to 30% by weight or less.