Nonblocking elastomeric polymer blends of ABA block copolymer and ethylene-vinyl acetate copolymer

• US 4,476,180 A
• Filed: 02/01/1983
• Issued: 10/09/1984
• Est. Priority Date: 02/01/1983
• Status: Expired due to Term

• Current Assignee: The Procter & Gamble Company
• Original Assignee: The Procter & Gamble Company
• Inventors: Wnuk, Andrew J.
• Primary Examiner(s): Briggs, Sr., Wilbert J.
• Application Number:
  US06/462,824
• Time in Patent Office: 616 Days
• Field of Search: 525/93, 428/220, 524/524
• US Class Current: 428/220
• CPC Class Codes: B29D 7/01 Films or sheets
• CPC Class Codes: C08J 2323/08 Copolymers of ethene C08J2323/16 takes precedence
• CPC Class Codes: C08J 5/18 Manufacture of films or sheets
• CPC Class Codes: C08L 2205/03 containing three or more polymers in a blend
• CPC Class Codes: C08L 23/06 Polyethene
• CPC Class Codes: C08L 23/08 Copolymers of ethene C08L23/16 takes precedence
• CPC Class Codes: C08L 23/0853 Vinylacetate
• 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 2666/24 Graft or block copolymers according to groups C08L51/00, C08L53/00 or C08L55/02; Derivatives thereof
• CPC Class Codes: C08L 53/02 of vinyl-aromatic monomers and conjugated dienes

Abstract

Thermoplastic elastomeric films comprise from about 40% to about 80% of an elastomeric block copolymer and from about 20% to about 60% of an ethylene-vinyl acetate copolymer. The block copolymer has at least two monoalkenyl arene polymer end blocks and at least one elastomeric conjugated diene midblock. The monoalkenyl arene polymer blocks comprise from about 8% to about 55% by weight of the block copolymer. The block copolymer has a melt index of less than about 10. The ethylene-vinyl acetate copolymer comprises from about 22% to about 33% vinyl acetate and has a melt index of less than about 0.6. The film is from about 0.03 mm to about 0.15 mm in thickness.

Claims

1. An elastomeric film comprising:

(a) from about 40% to about 80% of an elastomeric block copolymer having at least two monoalkenyl arene polymer end blocks A and at least one elastomeric conjugated diene mid block D, said blocks A comprising from about 8% to about 55% by weight of said block copolymer, said block copolymer having a melt index of less than about 10; and

(b) from about 20% to about 60% of an ethylene-vinyl acetate copolymer, said ethylene-vinyl acetate copolymer comprising from about 22% to about 33% vinyl acetate and having a melt index of less than about 0.6;

where said film is from about 0.03 mm to about 0.15 mm in thickness.

2. The film of claim 1 wherein said film is thermoplastic.

3. The film of claim 2 wherein said monoalkenyl arene polymer is polystyrene and said conjugated diene polymer is selected from a group consisting of polybutadiene and polyisoprene.

4. The film of claim 3 wherein said conjugated diene polymer is polybutadiene.

5. The film of claim 4 wherein said elastomeric block copolymer is a linear triblock copolymer A-D-A.

6. The film of claim 2 wherein said film further comprises:

(c) from about 10% to about 30% of an antiblock concentrate.

7. The film of claim 5 wherein said film further comprises:

(c) from about 10% to about 30% of an antiblock concentrate.

8. The film of claim 7 wherein said antiblock concentrate is a blend of polyethylene and silica.

9. The film of claim 8 wherein said antiblock concentrate contains about 50% polyethylene and about 50% silica.

10. The film of claim 5 wherein said film comprises from about 40% to about 60% of said elastomeric block copolymer and from about 20% to about 50% of said ethylene-vinyl acetate copolymer.

11. The film of claim 7 wherein said film comprises from about 40% to about 60% of said elastomeric block copolymer and from about 20% to about 50% of said ethylene-vinyl acetate copolymer.

12. The film of claim 5 wherein the melt index of said ethylene-vinyl acetate copolymer is less than about 0.4.

13. The film of claim 11 wherein the melt index of said ethylene-vinyl acetate copolymer is less than about 0.4.

14. The film of claim 11 wherein the melt index of said ethylene-vinyl acetate copolymer is about 0.3.

15. The film of claim 5 wherein said film is from about 0.04 mm to about 0.08 mm in thickness.

16. The film of claim 11 wherein said film is from about 0.04 mm to about 0.08 mm in thickness.

17. The film of claim 13 wherein said film is from about 0.04 mm to about 0.08 mm in thickness.

18. The film of claim 5 wherein said elastomeric block copolymer has a melt index of about 7.

19. The film of claim 14 wherein said elastomeric block copolymer has a melt index of about 7.

20. The film of claim 17 wherein said elastomeric block copolymer has a melt index of about 7.

21. The film of claim 5 wherein the vinyl acetate content of said ethylene-vinyl acetate copolymer is about 28%.

22. The film of claim 14 wherein the vinyl acetate content of said ethylene-vinyl acetate copolymer is about 28%.

23. The film of claim 20 wherein the vinyl acetate content of said ethylene-vinyl acetate copolymer is about 28%.