Compositions comprising thermoplastic vulcanizate, foamed material and articles made therefrom

Patent metadata

Field	Value
Publication number	US-9822231-B2
Application number	US-201315037167-A
Country	US
Kind code	B2
Filing date	Dec 24, 2013
Priority date	Dec 24, 2013
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

The present disclosure relates to a composition comprising a thermoplastic vulcanizate, a propylene-based elastomer and a foaming agent, and to a foamed material comprising said composition. The foamed material has increased tensile properties and tension set while attaining comparable effects of reduction of weight.

First claim

What is claimed is:

1. A composition comprising:
(a) a thermoplastic vulcanizate comprising:
(i) about 5 wt. % to about 85 wt. % of a thermoplastic resin component, and
(ii) about 15 wt. % to about 95 wt. % of a dispersed and at least partially vulcanized rubber component,

based on the total weight of the thermoplastic resin component and the rubber component;
(b) a propylene-based elastomer having at least about 60 wt. % propylene-derived units and about 5 to about 25 wt. % ethylene-derived units, based on total weight of the propylene-based elastomer, and a heat of fusion of less than about 80 J/g; and
(c) a foaming agent.

2. The composition of claim 1 , wherein the rubber component comprises at least one of ethylene-propylene rubber, ethylene-propylene-diene rubber, natural rubber, butyl rubber, halogenated rubber copolymer of p-alkystyrene and at least one isomonoolefin having 4 to 7 carbon atoms, a copolymer of isobutylene and divinyl-benzene, a rubber homopolymer of a conjugated diene having from 4 to 8 carbon atoms, a rubber copolymer having at least 50 weight percent repeat units from at least one conjugated diene having from 4 to 8 carbon atoms and a vinyl aromatic monomer having from 8 to 12 carbon atoms, or acrylonitrile monomer, or an alkyl substituted acrylonitrile monomer having from 3 to 8 carbon atoms, or an unsaturated carboxylic acid monomer, or an unsaturated anhydride of a dicarboxylic acid.

3. The composition of claim 1 , wherein the thermoplastic resin component comprises i) a polymer prepared from olefin monomers having 2 to 7 carbon atoms, or ii) a copolymer prepared from olefin monomers having 2 to 7 carbon atoms with a (meth)acrylate or a vinyl acetate.

4. The composition of claim 1 , wherein the thermoplastic resin component comprises at least one of polyethylene, polypropylene, and ethylene-propylene copolymer.

5. The composition of claim 1 , wherein the propylene-based elastomer is added in an amount of from about 1% to about 30% based on the total weight of the thermoplastic vulcanizate and the propylene-based elastomer.

6. The composition of claim 1 , wherein the propylene-based elastomer is added in an amount of from about 3% to about 15% based on the total weight of the thermoplastic vulcanizate and the propylene-based elastomer.

7. The composition of claim 1 , wherein the foaming agent is added in an amount of from about 0.1 to about 10.0% relative to the total weight of the thermoplastic vulcanizate and the propylene-based elastomer.

8. The composition claim 1 , wherein the foaming agent is added in an amount of from about 0.3 to about 3.0% relative to the total weight of the thermoplastic vulcanizate and the propylene-based elastomer.

9. The composition of claim 1 , wherein the foaming agent comprises at least one of 4,4′-oxybis benzene sulfonyl hydrazide, azodicarbonamide, azobisformamide, azobisisobutyronitrile, diazoaminobenzene, N,N-dimethyl-N,N-dinitroso terephthalamide, N,N-dinitrosopentamethylene-tetramine, benzenesulfonyl-hydrazide, benzene-1,3-disulfonyl hydrazide; diphenylsulfon-3-3, disulfonyl hydrazide, p-toluene sulfonyl semicarbizide, barium azodicarboxylate, butylamine nitrile, nitroureas, trihydrazino triazine, phenyl-methyl-uranthan, p-sulfonhydrazide, and peroxides.

10. The composition of claim 1 , wherein the foaming agent comprises azodicarbonamide.

11. The composition of claim 1 further comprising at least one of a filler, processing aid, curing agent, and accelerator.

12. A method for making a composition, comprising the steps of:
(1) combining
(a) a thermoplastic vulcanizate comprising:
(i) about 5 wt. % to about 85 wt. % of a thermoplastic resin component, and
(ii) about 15 wt. % to about 95 wt. % of a dispersed and at least partially vulcanized rubber component, based on the total weight of the thermoplastic resin component and the rubber component;

(b) a propylene-based elastomer having at least about 60 wt. % propylene-derived units and about 5 to about 25 wt. % ethylene-derived units, based on total weight of the propylene-based elastomer, and a heat of fusion of less than about 80 J/g; and
(c) a foaming agent; and

(2) forming the composition.

13. A foamed material made from the composition of claim 1 .

14. The foamed material of claim 13 having a tensile strength at break, as measured according to ISO-37, at least about 5% greater than the tensile strength at break of a comparative material sample that is a foamed material made from a composition free of the propylene-based elastomer, but is otherwise identical in terms of its constituents.

15. The foamed material of claim 13 having a tensile strength at break, as measured according to ISO 37, at least about 10% greater than the tensile strength at break of a comparative material sample that is a foamed material made from a composition free of the propylene-based elastomer, but is otherwise identical in terms of its constituents.

16. The foamed material of claim 13 having a tension set (25% extension at 80° C.), of less than about 20%.

17. The foamed material of claim 13 having an elongation at break, as measured according to ISO 37, of greater than 350%.

18. The method of claim 12 , wherein forming the composition comprises extruding the composition to form a foamed material.

19. The method of claim 18 , wherein the foamed material has a tensile strength at break, as measured according to ISO-37, at least 5% greater than the tensile strength at break of a comparative material sample that is a foamed material made from a composition free of the propylene-based elastomer, but is otherwise identical in terms of its constituents.

Assignees

• Exxonmobil Chemical Patents Inc

Inventors

• Yamaguchi Toshiaki
• Liu Laichun
• Li Liang
• Bednarik Michael W
• Guo Kai

Classifications

• C08J2321/00

  Characterised by the use of unspecified rubbers · CPC title

• C08J3/24

  Crosslinking, e.g. vulcanising, of macromolecules (mechanical aspects B29C35/00; crosslinking agents C08K) · CPC title

• C08J2421/00

  Characterised by the use of unspecified rubbers · CPC title

• C08K5/23

  Azo-compounds · CPC title

• C08J9/103

  Azodicarbonamide · CPC title