Thermoplastic elastomer compounds exhibiting shape memory via thermo-mechanical action

Patent metadata

Field	Value
Publication number	US-2016160038-A1
Application number	US-201615019173-A
Country	US
Kind code	A1
Filing date	Feb 9, 2016
Priority date	May 31, 2011
Publication date	Jun 9, 2016
Grant date	—

Abstract

A thermoplastic elastomer compound is disclosed having a high strain recovery rate and a high strain fixity rate to provide shape memory, preferably manageable shape memory. One type of thermoplastic elastomer compound is comprises a maleated styrenic block copolymer and polycaprolactone to achieve the shape memory. A second type of thermoplastic elastomer compound comprises styrene-ethylene/butylene-styrene and a paraffin wax having less than about 0.5% oil content. Shape modes of articles made from the thermoplastic elastomer compound can be altered by at least one thermo-mechanical event to cause deformation of the compound from a first shape to a second shape with retention of the compound in the second shape for any reasonable time interval.

First claim

What is claimed is:

1 . A thermoplastic elastomer compound comprising:
(a) maleated polystyrene-poly(ethylene-butylene)-polystyrene block copolymer; and (b) polycaprolactone; wherein the thermoplastic elastomer compound has shape memory.

2 . The thermoplastic elastomer compound of claim 1 , wherein the thermoplastic elastomer compound further comprises plasticizer and polyolefin.

3 . The thermoplastic elastomer compound of claim 1 , wherein the thermoplastic elastomer compound further comprises one or more additives selected from the group consisting of adhesion promoters; biocides; anti-fogging agents; anti-oxidants; anti-static agents; blowing agents; dispersants; extenders; fillers; flame retardants; foaming agents; smoke suppressants; impact modifiers; initiators; lubricants; micas; pigments; colorants; dyes; oils; plasticizers; processing aids; release agents; silanes; titanates; zirconates; slip agents; anti-blocking agents; stabilizers; stearates; ultraviolet light absorbers; viscosity regulators; waxes; and combinations of these additives.

4 . The thermoplastic elastomer compound of claim 1 , wherein the thermoplastic elastomer compound has a strain recovery rate of at least 65%.

5 . The thermoplastic elastomer compound of claim 1 , wherein the thermoplastic elastomer compound has a strain fixity rate of at least 65%.

6 . The thermoplastic elastomer compound of claim 1 , wherein the shape memory is a manageable shape memory.

7 . The thermoplastic elastomer compound of claim 1 , wherein the thermoplastic elastomer compound is capable of being reshaped by at least one thermo-mechanical event.

8 . The thermoplastic elastomer compound of claim 7 , wherein the thermo-mechanical event is alteration of temperature by at least 40° C. under sufficient stress to cause deformation of the compound from a first shape to a second shape with retention of the compound in the second shape for any time interval.

9 . The thermoplastic elastomer compound of claim 1 , wherein the thermoplastic elastomer compound is in the form of extruded pellets.

10 . An article molded from the thermoplastic elastomer compound of claim 1 .

11 . The article of claim 10 , wherein the article is reshaped by at least one thermo-mechanical event.

12 . The article of claim 11 , wherein the thermo-mechanical event is alteration of temperature by at least 40° C. under sufficient stress to cause deformation of the article from a first shape to a second shape with retention of the article in the second shape for any time interval.

13 . The article of claim 10 , wherein the article is an injection molded article.

14 . The article of claim 10 , wherein the article has a Shore A hardness of less than about 60.

15 . A method of using the article of claim 10 , the method comprising the steps of:
(a) performing a thermo-mechanical event on the article; and (b) optionally, performing a second thermo-mechanical event on the article; wherein the article expands or contracts in at least one dimension of the article with each of step (a) and optional step (b) either sequentially or concurrently.

Assignees

• Polyone Corp

Inventors

• Xu Liang

Classifications

• C08L53/025

  modified · CPC title

• C08L2207/04

  Thermoplastic elastomer · CPC title

• C08L91/06 Primary

  Waxes · CPC title

• C08L2205/035

  containing four or more polymers in a blend · CPC title

• C08L51/06

  grafted on to homopolymers or copolymers of aliphatic hydrocarbons containing only one carbon-to-carbon double bond · CPC title