MICRO-STRUCTURED OPTICALLY CLEAR ADHESIVES

• US 20140262002A1
• Filed: 10/24/2012
• Published: 09/18/2014
• Est. Priority Date: 10/24/2011
• Status: Abandoned Application

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Suwa, Toshihiro, Everaerts, Albert I., Kinoshita, Yasuhiro, Mikami, Haruyuki
• Application Number:
  US14/352,189
• Publication Number:
  US 20140262002A1
• Time in Patent Office: Days
• US Class Current: 156/249
• CPC Class Codes: C09J 5/06 involving heating of the applied adhesive
• CPC Class Codes: C09J 7/10 without carriers
• CPC Class Codes: C09J 7/29 Laminated material metallised plastics C09J7/22
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor
• CPC Class Codes: Y10T 428/24479 including variation in thickness
• CPC Class Codes: Y10T 428/24612 Composite web or sheet

Abstract

A micro-structured optically clear adhesive, including a first major surface and a second major surface, wherein at least one of the first and second major surfaces comprises a micro-structured surface of interconnected micro-structures in at least one of the planar dimensions (x-y), is disclosed. The micro-structured optically clear adhesive has a tan delta value of at least about 0.3 at a lamination temperature and is non-crosslinked or lightly crosslinked. The micro-structured surface may include indentations having a depth of between about 5 and about 80 microns. A method of laminating a first substrate and a second substrate without the use of a vacuum is provided. The method includes providing a micro-structured optically clear adhesive, removing a release liner from a first side of the micro-structured optically clear adhesive, contacting the first side of the micro-structured optically clear adhesive with a surface of the first substrate, removing a micro-structured release liner from a second side of the micro-structured optically clear adhesive to expose a micro-structured surface, and contacting the micro-structured surface with a surface of the second substrate.

Claims

1. An optically clear adhesive comprising:

a first major surface and a second major surface;

wherein at least one of the first and second major surfaces comprises a micro-structured surface of interconnected micro-structures in at least one planar (x-y) dimension;

wherein the optically clear adhesive has a tan delta value of at least about 0.3 at a lamination temperature; and

wherein the optically clear adhesive is non-crosslinked or lightly crosslinked.

2. The optically clear adhesive of claim 1, wherein the micro-structured surface comprises interconnected features in at least two planar dimensions.

3. The optically clear adhesive of claim 1, wherein the micro-structured surface comprises indentations having a depth of between about 5 and about 80 microns.

4. The optically clear adhesive of claim 1, wherein both the first and second major surfaces comprise a micro-structured surface.

5. The optically clear adhesive of claim 1, wherein the micro-structured surface comprises indentations and protrusions.

6. The optically clear adhesive of claim 1, wherein the optically clear adhesive is one of a hot-melt optically clear adhesive, a solvent coated optically clear adhesive, an on-web polymerized optically clear adhesive and a heat-activated adhesive.

7. A method of laminating a first substrate and a second substrate without the use of a vacuum, the method comprising:

providing a micro-structured optically clear adhesive comprising a first major surface and a second major surface, wherein at least one major surface comprises a micro-structured surface, wherein the micro-structured optically clear adhesive has a tan delta value of at least about 0.3 at a lamination temperature;

removing a release liner from the first major surface of the micro-structured optically clear adhesive;

contacting the first major surface of the micro-structured optically clear adhesive with a surface of the first substrate;

removing a micro-structured release liner from the second major surface of the micro-structured optically clear adhesive to expose a micro-structured surface, wherein the micro-structured surface comprises interconnected micro-structures in at least one planar dimension; and

contacting the micro-structured surface with a surface of the second substrate.

8. The method of claim 7, further comprising subjecting the laminate to at least one of heat and pressure.

9. The method of claim 7, wherein the optically clear adhesive has a tan value of at least about 0.5 at the lamination temperature.

10. The method of claim 7, wherein the micro-structured surface comprises interconnected features in at least two dimensions.

11. The method of claim 7, wherein the micro-structured surface comprises indentations having a depth of between about 5 and about 80 microns.

12. The method of claim 7, wherein both the first and second major surfaces comprise a micro-structured surface.

13. The method of claim 7, wherein the micro-structured surface comprises indentations and protrusions.

17. The method of claim 7, wherein at least one of the first and second substrates comprises a topographical feature.

14. (canceled)

15. (canceled)

16. (canceled)

18. A method of vacuumless lamination of a first substrate and a second substrate, the method comprising:

providing a micro-structured optically clear adhesive comprising a first major surface and a second major surface, wherein at least one major surface comprises a micro-structured surface, wherein the micro-structured optically clear adhesive has a tan delta value of at least about 0.3 at a temperature of between about 20°

C. and about 60°

C.;

contacting a surface of a micro-structured optically clear adhesive with a surface of the first substrate;

applying the micro-structured surface of the micro-structured optically clear adhesive with a surface of the second substrate to form a bond line, wherein the micro-structured surface comprises interconnected micro-structures in at least one planar dimension;

allowing point-to-point contact between the micro-structured surface and the surface of the second substrate;

uniformly spreading the micro-structured optically clear adhesive along the surface of the second substrate;

filling in continuous, open air space to substantially remove air from the bond line to form a laminate.

19. The method of claim 18, wherein the optically clear adhesive is non-crosslinked or lightly crosslinked.

20. The method of claim 18, further comprising subjecting the laminate to one of pressure and heat.

23. The method of claim 18, wherein the micro-structured surface comprises indentations having a depth of between about 5 and about 80 microns.

24. The method of claim 18, wherein both the first and second major surfaces comprise a micro-structured surface.

25. The method of claim 18, wherein at least one of the first and second substrates comprises a topographical feature.

21. (canceled)

22. (canceled)