Debondable adhesive article and methods of making and using the same

Patent metadata

Field	Value
Publication number	US-9821529-B2
Application number	US-201214233398-A
Country	US
Kind code	B2
Filing date	Jul 19, 2012
Priority date	Jul 19, 2011
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

A heat-debondable adhesive article having two opposing sides is provided that includes a shape-memory polymer sheet in its temporary strained shape that includes a plurality of slits therein and a first adhesive on one opposing side of the polymer sheet and a second adhesive on the other opposing side of the polymer sheet. The provided article, optionally, includes a first substrate in contact with the first adhesive and a second substrate in contact with the second adhesive. The article can be debonded by heating the article to a temperature equal to or greater than a transition temperature for the shape-memory polymer sheet.

First claim

What is claimed is:

1. A heat-debondable adhesive article comprising:
a shape-memory polymer sheet comprising polyethylene with an area having a strained temporary shape and an intrinsic shape, first and second opposing surfaces, and comprising a plurality of slits each having a width therein, and wherein the plurality of slits defines a total slit length, wherein the first opposing surface of the shape-memory polymer sheet is functionalized by corona treatment or treatment with a chemical primer, wherein if heated to a temperature below 80° C., the shape-memory polymer sheet does not undergo a substantial change in length, and wherein if heated to or above a transition temperature range, the shape-memory polymer sheet at least partially converts from its strained temporary shape to its intrinsic shape;
a first adhesive layer having a first thickness and first and second opposing surfaces, wherein the first adhesive layer comprises a foamed adhesive, and

wherein a substantial portion of the first opposing surface of the first adhesive layer is disposed upon a substantial portion of the first opposing surface of the shape-memory polymer sheet in its strained temporary shape; and
a second adhesive layer having a second thickness, first and second opposing sides, wherein a substantial portion of the first opposing side of the second adhesive layer is disposed upon a substantial portion of the second opposing side of the shape-memory polymer sheet in its strained temporary shape,
wherein the shape-memory polymer sheet in its intrinsic shape debonds from the first adhesive layer.

2. A heat-debondable adhesive article according to claim 1 , wherein the shape-memory polymer sheet is biaxially oriented and has a maximum shrink tension in one direction.

3. A heat-debondable adhesive article according to claim 1 , wherein the ratio of the total length of the plurality of slits to the area of the shape-memory polymer sheet is greater than about 0.35 cm/cm 2 .

4. A heat-debondable adhesive article according to claim 1 , wherein the width of each of the slits in the plurality of slits is less than the thickness of the first adhesive layer.

5. A heat-debondable adhesive article according to claim 1 , wherein the shape-memory polymer sheet comprises physical crosslinks.

6. A heat-debondable adhesive article according to claim 5 , wherein the shape-memory polymer sheet comprises thermoplastic urethanes or linear, high molecular weight polynorbornene.

7. A heat-debondable adhesive article according to claim 1 , wherein the shape-memory polymer sheet comprises covalent crosslinks.

8. A heat-debondable adhesive article according to claim 7 , wherein the shape-memory polymer sheet comprises epoxies, thermoset urethanes, acrylates, styrenic polymers, crosslinked olefins, or crosslinked ring-opening metathesis polymers.

9. A heat-debondable adhesive article according to claim 1 , wherein the plurality of slits divides the shape-memory polymer sheet into two or more pieces.

10. A heat-debondable adhesive article according to claim 9 , wherein the plurality of slits comprises a cross-hatch pattern.

11. A heat-debondable adhesive article according to claim 1 , wherein at least one of the first adhesive layer and the second adhesive layer comprise a pressure-sensitive adhesive.

12. A heat-debondable adhesive article according to claim 11 , wherein the pressure-sensitive adhesive is selected from an acrylic adhesive, a block copolymer adhesive, a polyurethane adhesive, and a sulfonated polyurethane adhesive.

13. A heat-debondable adhesive article according to claim 2 , wherein there is a temperature at which the shrink tension of the shape-memory polymer is sufficiently high to cause a substantial change in the area of the shaped-memory polymer sheet.

14. A heat-debondable adhesive article according to claim 1 , wherein upon heating to a transition temperature, the shape-memory polymer sheet converts to its intrinsic shape such that the first adhesive layer is now disposed upon less than about 65% of the surface of the first substrate.

15. A heat-debondable adhesive article according to claim 1 , further comprising:
a first substrate having a surface in contact with a substantial portion of e second opposing surface of the first adhesive layer.

16. A heat-debondable adhesive article according to claim 15 , further comprising:
a second substrate in contact with a substantial portion of the second opposing side of the second adhesive.

17. A heat-debondable adhesive article according to claim 1 , further comprising an energy absorbing layer.

18. The heat-debondable adhesive article of claim 1 wherein the first adhesive layer or the second adhesive layer comprises a plurality of slits each having a width therein, and wherein the plurality of slits in the first adhesive layer or the second adhesive layer together with the plurality of slits in the shape-memory polymer sheet define a total slit length.

19. The heat-debondable adhesive article of claim 1 wherein the shape-memory polymer sheet in the intrinsic shape does not debond from the second adhesive layer.

20. The heat-debondable adhesive article of claim 1 wherein the shape-memory polymer sheet in the intrinsic shape cleanly debonds from the first adhesive layer.

21. The heat-debondable adhesive article of claim 1 wherein the first adhesive layer comprises an acrylic foam tape.

Assignees

• Rule Joseph D
• Behling Ross E
• Lee Nicholas A
• Lebow Leslie M
• 3M Innovative Properties Co

Inventors

• Rule Joseph D
• Behling Ross E
• Lee Nicholas A
• Lebow Leslie M

Classifications

• C09J5/06 Primary

  involving heating of the applied adhesive · CPC title

• C09J2201/606

  Chemistry & Metallurgy · mapped topic

• Y10T156/1062

  Prior to assembly · CPC title

• B32B3/18 Primary

  characterised by an internal layer formed of separate pieces of material {which are juxtaposed side-by-side (B32B5/02 takes precedence)} · CPC title

• C09J7/0264

  Chemistry & Metallurgy · mapped topic