Multilayer optical adhesives and methods of making same

Patent metadata

Field	Value
Publication number	US-2016016338-A1
Application number	US-201414335326-A
Country	US
Kind code	A1
Filing date	Jul 18, 2014
Priority date	Jul 18, 2014
Publication date	Jan 21, 2016
Grant date	—

Abstract

A multilayer optical adhesive including a first viscoelastic or elastomeric adhesive layer and a second viscoelastic or elastomeric adhesive layer. A crosslinked or soluble resin layer may be disposed between the first viscoelastic or elastomeric adhesive layer and the second viscoelastic or elastomeric adhesive layer or the first viscoelastic or elastomeric adhesive layer may be immediately adjacent to the second viscoelastic or elastomeric adhesive layer. An interface between immediately adjacent layers is structured and there is a difference in refractive indices across the interface.

First claim

What is claimed is:

1 . An optical adhesive comprising:
a first viscoelastic or elastomeric adhesive layer having a first refractive index; a first crosslinked or soluble resin layer immediately adjacent the first viscoelastic or elastomeric adhesive layer, the first crosslinked or soluble resin layer having a second refractive index different from the first refractive index; a second viscoelastic or elastomeric adhesive layer immediately adjacent the first crosslinked or soluble resin layer opposite the first viscoelastic or elastomeric adhesive layer; wherein a first interface between the first viscoelastic or elastomeric adhesive layer and the first crosslinked or soluble resin layer is structured and wherein each of the first viscoelastic or elastomeric adhesive layer, the first crosslinked or soluble resin layer and the second viscoelastic or elastomeric adhesive layer are substantially transmissive.

2 . The optical adhesive of claim 1 , wherein a second interface between the first crosslinked or soluble resin layer and the second viscoelastic or elastomeric adhesive layer is structured.

3 . The optical adhesive of claim 1 , wherein the first viscoelastic or elastomeric adhesive layer is a first viscoelastic optically clear adhesive and the second viscoelastic or elastomeric adhesive layer is a second viscoelastic optically clear adhesive.

4 . The optical adhesive of claim 1 , wherein a refractive index contrast across the first interface is at least 0.001 and less than about 0.5.

5 . The optical adhesive of claim 1 , wherein the first interface includes a grating having a peak to valley height h and a pitch and wherein h multiplied by |n 1 −n 2 | is in a range of about 150 nm to about 350 nm and the pitch is in a range of about 2 microns to about 50 microns.

6 . The optical adhesive of claim 1 , wherein the first crosslinked or soluble resin layer is substantially continuous.

7 . The optical adhesive of claim 1 , wherein the first crosslinked or soluble resin layer is discontinuous.

8 . The optical adhesive of claim 7 , wherein the first crosslinked or soluble resin layer comprises a plurality of discrete objects in a pattern.

9 . The optical adhesive of claim 1 , wherein the first crosslinked or soluble resin layer comprises a first sublayer immediately adjacent the first viscoelastic or elastomeric resin layer and a second sublayer immediately adjacent the first sublayer and immediately adjacent the second viscoelastic or elastomeric adhesive layer, wherein the first sublayer has a first refractive index and the second sublayer has a second refractive index different from the first refractive index and a second interface between the first sublayer and the second sublayer is structured.

10 . The optical adhesive of claim 1 , further comprising a second crosslinked or soluble resin layer immediately adjacent the second viscoelastic or elastomeric adhesive layer opposite the first crosslinked or soluble resin layer.

11 . The optical adhesive of claim 10 , further comprising a third viscoelastic or elastomeric adhesive layer immediately adjacent the second crosslinked or soluble resin layer opposite the second viscoelastic or elastomeric adhesive layer.

12 . The optical adhesive of claim 11 , wherein at least two of the first interface, the second interface, a third interface between the second crosslinked or soluble resin layer and the second viscoelastic or elastomeric adhesive layer, and a fourth interface between the third viscoelastic or elastomeric adhesive layer and the second crosslinked or soluble resin are structured.

13 . The optical adhesive of claim 12 , wherein the first, second, third and fourth interfaces includes a first grating extending in a first direction and a second grating extending in a second direction different from the first direction.

14 . The optical adhesive of claim 1 , wherein at least one of the first viscoelastic or elastomeric adhesive layer, the first crosslinked or soluble resin layer, and the second viscoelastic or elastomeric adhesive layer includes a plurality of particles having a mean diameter in the range of about 0.5 microns to about 30 microns, and wherein an absolute value of a refractive index difference between particles in the plurality of particles and a medium in which they are located is in the range of about 0.001 to about 0.1.

15 . An optical adhesive comprising:
a first viscoelastic or elastomeric adhesive layer having a first major surface, an unstructured second major surface, and having a first refractive index n 1 ; a second viscoelastic or elastomeric adhesive layer immediately adjacent the first major surface of the first viscoelastic or elastomeric adhesive layer, the second viscoelastic or elastomeric adhesive having a second refractive index n 2 ; wherein a first interface between the first viscoelastic or elastomeric adhesive layer and the second viscoelastic or elastomeric adhesive layer includes a substantially continuous grating having a peak to valley height h and a pitch and wherein h multiplied by |n 1 −n 2 | is in a range of about 150 nm to about 350 nm and the pitch is in a range of about 2 microns to about 50 microns.

16 . The optical adhesive of claim 15 , wherein the first viscoelastic or elastomeric adhesive layer is a first viscoelastic optically clear adhesive and the second viscoelastic or elastomeric adhesive layer is a second viscoelastic optically clear adhesive.

17 . The optical adhesive of claim 15 , further comprising a first release liner having a first release surface immediately adjacent the unstructured second major surface and a second release liner having a second release surface immediately adjacent the second viscoelastic or elastomeric adhesive layer opposite the first viscoelastic or elastomeric adhesive layer.

18 . The optical adhesive of claim 15 , wherein at least one of the first viscoelastic or elastomeric adhesive layer and the second viscoelastic or elastomeric adhesive layer includes a plurality of particles having a mean diameter in the range of about 0.5 microns to about 30 microns, and wherein an absolute value of a refractive index difference between particles in the plurality of particles and a medium in which they are located is in the range of about 0.001 to about 0.1.

19 . An optical adhesive comprising:
a viscoelastic or elastomeric adhesive layer having a first major surface and having a first refractive index n 1 ; a discontinuous layer immediately adjacent the first major surface of the viscoelastic or elastomeric adhesive layer, the discontinuous layer having a second refractive index n 2 different from n 1 ; an additional layer disposed immediately adjacent the discontinuous layer opposite the viscoelastic or elastomeric adhesive layer, the additional layer having a third refractive index n 3 , the additional layer in contact with the viscoelastic or elastomeric adhesive layer, wherein a first interface between the viscoelastic or elastomeric adhesive layer and the discontinuous layer, a second interface between the additional layer and the discontinuous layer, and a third interface between the viscoelastic or elastomeric adhesive layer and the additional layer comprise a grating having a peak to valley height h and a pitch and wherein h multiplied by |n 1 −n 2 | is in a range of about 150 nm to about 350 nm and the pitch is in a range of about 2 microns to about 50 microns.

20 . An optical adhesive comprising:
a first release film having a first release surfa

Assignees

• 3M Innovative Properties Co

Inventors

• Radcliffe Marc D
• Hennen Daniel W
• Sitter Brett J
• Steiner Michael L
• Hoffend Jr Thomas R
• Sherman Audrey A
• Stradinger John J
• Benson Jr Olester

Classifications

• C09J7/20 Primary

  characterised by their carriers · CPC title

• B29C41/22 Primary

  Making multilayered or multicoloured articles · CPC title

• B29D11/0073

  Optical laminates · CPC title

• B29L2011/00

  Optical elements, e.g. lenses, prisms · CPC title

• C09J7/10

  without carriers · CPC title