Polymer compositions

• US 20030153680A1
• Filed: 02/08/2002
• Published: 08/14/2003
• Est. Priority Date: 02/08/2002
• Status: Active Grant

• Current Assignee: Teknor Apex Company
• Original Assignee: Teknor Apex Company
• Inventors: Patel, Raman, Thornton, Wayne, Saunders, Keith G., McBride, Tonya M., Weng, Dexi
• Granted Patent: US 7,196,137 B2
• Time in Patent Office: Days
• US Class Current: 525/88
• CPC Class Codes: C08L 23/10 Homopolymers or copolymers of propene
• CPC Class Codes: C08L 23/12 Polypropene
• CPC Class Codes: C08L 23/16 Elastomeric ethene-propene or ethene-propene-diene copolymers, e.g. EPR and EPDM rubbers
• 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 2666/06 Homopolymers or copolymers of unsaturated hydrocarbons; Derivatives thereof
• CPC Class Codes: C08L 2666/24 Graft or block copolymers according to groups C08L51/00, C08L53/00 or C08L55/02; Derivatives thereof
• CPC Class Codes: C08L 53/00 Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 53/02 of vinyl-aromatic monomers and conjugated dienes
• CPC Class Codes: C08L 53/025 modified

Abstract

The invention is based on the discovery of useful combinations of fully cross-linked thermoplastic vulcanizates with styrenic block copolymers. The new combinations of the invention can provide a synergistic effect. Specifically, the compositions formed thereby can be both softer and more elastic than would be expected on the basis of the properties of the individual components. Such compositions can be used in numerous applications, including, for example, any application for which a soft material with very good recovery is desired.

Claims

1. A composition comprising:

a styrenic block copolymer; and

a substantially fully cross-linked thermoplastic vulcanizate.

2. The composition of claim 1, wherein the styrenic block copolymer is selected from the group consisting of A-B-A triblock copolymers, A-B-A-B tetrablock copolymers, A-B-A-B-A pentablock copolymers, and mixtures thereof.

3. The composition of claim 2, wherein A is a hard block comprising vinylarene monomers and B is a soft block comprising olefinic monomers.

4. The composition of claim 2, wherein the styrenic block copolymer has a styrene-ethylene butylene-styrene structure, a styrene-ethylene propylene-styrene structure, or a styrene-ethylene ethylene propylene-styrene structure.

5. The composition of claim 1, wherein the thermoplastic matrix is a polyolefin resin.

6. The composition of claim 1, wherein the thermoplastic vulcanizate is a dynamically vulcanized blend of polyolefin resin and a rubber.

7. The composition of claim 1, wherein the thermoplastic vulcanizate is a dynamically vulcanized blend of a thermoplastic matrix and an ethylene-propylene-diene copolymer rubber.

8. The composition of claim 1, wherein the amount of the styrenic block copolymer is at least about 5 parts per 100 parts of the thermoplastic vulcanizate.

9. The composition of claim 8, wherein the amount of the styrenic block copolymer is between about 5 parts and 400 parts per 100 parts of the thermoplastic vulcanizate.

10. The composition of claim 9, wherein the amount of the styrenic block copolymer is between about 15 parts and 300 parts per 100 parts of the thermoplastic vulcanizate.

11. The composition of claim 1, further comprising mineral oil.

12. The composition of claim 8, further comprising mineral oil.

13. The composition of claim 12, wherein the amount of the mineral oil is at least about 10 parts per 100 parts of the thermoplastic vulcanizate.

14. The composition of claim 13, wherein the amount of the mineral oil is between about 20 parts and 800 parts per 100 parts of the thermoplastic vulcanizate.

15. The composition of claim 14, wherein the amount of the mineral oil is between about 25 parts and 600 parts per 100 parts of the thermoplastic vulcanizate.

16. A composition of claim 1 having a hardness less than about 50 Shore A.

17. A composition of claim 1 having a hardness between about 10 and 45 Shore A.

18. A composition of claim 1 having a hardness between about 15 and 35 Shore A.

19. A composition of claim 1 having a 22 hour compression set at 70°

C. of less than about 30%.

20. A composition of claim 17 having a 22 hour compression set at 70°

C. of between about 10% and 25%.

21. A composition of claim 18 having a 22 hour compression set at 70°

C. of between about 15% and 23%.

22. A composition comprising:

a styrenic block copolymer having a styrene-ethylene butylene-styrene structure, a styrene-ethylene propylene-styrene structure, or a styrene-ethylene ethylene propylene-styrene structure; and

a substantially fully cross-linked blend of polypropylene and an ethylene-propylene-diene copolymer rubber.

23. The composition of claim 22, further comprising mineral oil.