Shape memory material with improved mechanical properties

Patent metadata

Field	Value
Publication number	US-11591503-B2
Application number	US-201916957304-A
Country	US
Kind code	B2
Filing date	Jan 25, 2019
Priority date	Jan 25, 2018
Publication date	Feb 28, 2023
Grant date	Feb 28, 2023

Abstract

A composition includes an epoxy-based curable adhesive having at least one an epoxy resin modified acrylonitrile-butadiene copolymer and at least one thermoplastic elastomer. The at least one thermoplastic elastomer is present in the curable adhesive as a penetrating polymer network. Further, an expandable article is composed of the composition, a reinforcing element includes a support and an expandable article, a method for reinforces cavities of structural components, and the composition is used as a shape memory material.

First claim

The invention claimed is:

1. A composition comprising:
i) a curable adhesive comprising:
a) at least one epoxy resin and
b) at least one epoxy resin modified acrylonitrile-butadiene copolymer, and

ii) at least one thermoplastic elastomer, wherein
the at least one thermoplastic elastomer is present in the curable adhesive as a penetrating polymer network, and
the composition contains a semi-interpenetrating polymer network (S-IPN) comprising a first continuous phase comprising the curable adhesive and a second continuous phase comprising the at least one thermoplastic elastomer.

2. The composition according to claim 1 , wherein the at least one thermoplastic elastomer has a melting temperature (T m ), which is above the glass transition temperature of the curable adhesive and/or wherein the curable adhesive has a glass transition temperature (T g ) in the range of 23-95° C.

3. The composition according to claim 1 , wherein the at least one thermoplastic elastomer is present in an amount in a range of 15-40 wt.-%, based on the total weight of the composition.

4. The composition according to claim 1 , wherein the at least one thermoplastic elastomer is selected from the group consisting of ethylene based olefin copolymers, propylene-based olefin copolymers, and ethylene vinyl acetate copolymers.

5. The composition according to claim 1 , wherein the at least one epoxy resin is present in an amount in a range of 20-70 wt.-%, based on the total weight of the composition.

6. The composition according to claim 1 , wherein the at least one epoxy resin modified acrylonitrile-butadiene copolymer is present in an amount in a range of 1.0-30.0 wt.-%, based on the total weight of the composition.

7. The composition according to claim 1 , wherein the at least one epoxy resin modified acrylonitrile-butadiene copolymer comprises at least one acrylonitrile-butadiene rubber in an amount in a range of 5-50 wt.-%, based on the weight of the at least one epoxy resin modified acrylonitrile-butadiene copolymer.

8. The composition according to claim 1 , wherein the curable adhesive is a thermally curable adhesive.

9. The composition according to claim 1 , further comprising at least one inorganic fiber filler in an amount in a range of 0.5-20.0 wt.-%, based on the total weight of the composition.

10. An expandable article composed of the composition according to claim 1 , wherein the at least one thermoplastic elastomer is in a compressed state.

11. The expandable article according to claim 10 obtained by subjecting the composition to a reversible deforming process comprising:
I) providing the composition,
wherein
the at least one thermoplastic elastomer is present in the curable adhesive as the penetrating polymer network in an original shape, in which the at least one thermoplastic elastomer is in a relaxed state,

II) heating the composition in its original shape to a temperature above the glass transition temperature of the curable adhesive and below the melting temperature of the at least one thermoplastic elastomer,
III) mechanically deforming the heated composition from its original shape to a different temporary shape, in which the at least thermoplastic elastomer is in compressed state, and
IV) cooling the composition in its temporary shape to a temperature below the glass transition temperature of the curable adhesive.

12. A reinforcing element for reinforcing cavities of structural components comprising a support and the expandable article according to claim 10 , which is indirectly or directly attached to a surface of the support.

13. A method for reinforcing cavities of structural components, comprising:
i′) placing the reinforcement element according to claim 12 in a cavity of a structural component,
ii″) heating the expandable article to a temperature above the glass transition temperature of the curable adhesive, and
iii″) curing of the curable adhesive.

14. The method according to claim 13 , wherein the curable adhesive is cured by heating.

15. A method comprising: applying the composition according to claim 1 as a shape memory material.

16. A composition comprising:
i) a curable adhesive comprising:
a) at least one epoxy resin and
b) at least one epoxy resin modified acrylonitrile-butadiene copolymer, and

ii) at least one thermoplastic elastomer selected from the group consisting of ethylene based olefin copolymers, propylene-based olefin copolymers, and ethylene vinyl acetate copolymers,

wherein the at least one thermoplastic elastomer is present in the curable adhesive as a penetrating polymer network.

Assignees

• Sika Tech Ag

Inventors

• Frick Karsten
• Keller Alina

Classifications

• B29C61/06

  Making preforms having internal stresses, e.g. plastic memory · CPC title

• C09J163/00 Primary

  Adhesives based on epoxy resins; Adhesives based on derivatives of epoxy resins · CPC title

• C08C19/06

  Epoxidation · CPC title

• C08L2201/12

  Shape memory · CPC title

• C08L23/12

  Polypropene · CPC title