Optical adhesive sheet

Patent metadata

Field	Value
Publication number	US-10465098-B2
Application number	US-201515510403-A
Country	US
Kind code	B2
Filing date	Jun 23, 2015
Priority date	Sep 11, 2014
Publication date	Nov 5, 2019
Grant date	Nov 5, 2019

Abstract

The present invention provides an optical adhesive sheet including a layered structure of a first adhesive layer and a second adhesive layer, in which the first adhesive layer has a glass transition temperature of −50° C. to −30° C. and a modulus of 0.3×10 5 Pa to about 0.6×10 5 Pa, and the second adhesive layer has a glass transition temperature of −20° C. to −10° C. and a modulus of 0.7×10 5 Pa to 1.0×10 5 Pa.

First claim

The invention claimed is:

1. An optical adhesive sheet comprising a layered structure of a first adhesive layer and a second adhesive layer,
wherein the first adhesive layer is formed by curing a first adhesive composition comprising 1) a first acrylic resin formed by copolymerizing two or more (meth)acrylic acid ester-based monomers and a crosslinkable monomer containing a hydroxy group; and 2) a first polyfunctional (meth)acrylate-based compound,
wherein the second adhesive layer is formed by curing a second adhesive composition comprising a second acrylic resin formed by copolymerizing 80 wt % to 95 wt % of a (meth)acrylic acid ester-based monomer and 5 wt % to 20 wt % of a crosslinkable monomer containing a carboxyl group,
wherein the first polyfunctional (meth)acrylate-based compound is a combination of a polyfunctional (meth)acrylate-based monomer and a polyfunctional (meth)acrylate-based oligomer, wherein a weight ratio of the polyfunctional (meth)acrylate-based monomer to the polyfunctional (meth)acrylate-based oligomer is 1:5 to 1:10,
wherein the first adhesive layer has a glass transition temperature of −50° C. to −30° C. and a modulus of 0.3×10 5 Pa to 0.6×10 5 Pa, and
the second adhesive layer has a glass transition temperature of −20° C. to −10° C. and a modulus of 0.7×10 5 Pa to 1.0×10 5 Pa.

2. The optical adhesive sheet of claim 1 , wherein in a total polymerizable monomer component which forms the first acrylic resin, a content of the two or more (meth)acrylic acid ester-based monomers is 70 wt % to 90 wt %, and a content of the crosslinkable monomer containing a hydroxy group is 10 wt % to 30 wt %.

3. The optical adhesive sheet of claim 1 , wherein the first adhesive composition comprises 0.01 parts by weight to 5.1 parts by weight of the first polyfunctional (meth)acrylate-based compound based on 100 parts by weight of the first acrylic resin.

4. The optical adhesive sheet of claim 1 , wherein the first adhesive layer is formed by UV-curing the first adhesive composition.

5. The optical adhesive sheet of claim 1 , wherein the second adhesive composition further comprises 0.01 parts by weight to 5.1 parts by weight of a second polyfunctional (meth)acrylate-based compound based on 100 parts by weight of the second acrylic resin.

6. The optical adhesive sheet of claim 1 , wherein the second adhesive layer is formed by thermally curing the second adhesive composition.

7. The optical adhesive sheet of claim 1 , wherein a thickness of the first adhesive layer is larger than a thickness of the second adhesive layer.

8. The optical adhesive sheet of claim 7 , wherein the thickness of the first adhesive layer is 50 μm to 300 μm.

9. The optical adhesive sheet of claim 7 , wherein the thickness of the second adhesive layer is 5 μm to 50 μm.

10. The optical adhesive sheet of claim 1 , wherein the first polyfunctional (meth)acrylate-based oligomer has a weight average molecular weight of 1,000 g/mol to 3,000 g/mol.

11. The optical adhesive sheet of claim 5 , wherein the second polyfunctional (meth)acrylate-based compound comprises a polyfunctional (meth)acrylate-based monomer, a polyfunctional (meth)acrylate-based oligomer, or a combination thereof.

12. The optical adhesive sheet of claim 11 , wherein the polyfunctional (meth)acrylate-based oligomer has a weight average molecular weight of 1,000 g/mol to 3,000 g/mol.

13. The optical adhesive sheet of claim 1 , wherein the crosslinkable monomer containing a carboxyl group is acrylic acid.

Assignees

• Lg Chemical Ltd

Inventors

• Lee Joo-Hyun
• Kim Jang-Soon
• Jung Bu-Gi
• Kim Sang-Hwan
• Park Sung-Chan
• Yoon Chan-Oh
• Lee Han-Na

Classifications

• C09J2203/318

  for the production of liquid crystal displays · CPC title

• C09J4/06

  {Organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond} in combination with a macromolecular compound other than an unsaturated polymer of groups C09J159/00 - C09J187/00 · CPC title

• G02B1/04

  made of organic materials, e.g. plastics (G02B1/08 takes precedence) · CPC title

• C08F265/06

  Polymerisation of acrylate or methacrylate esters on to polymers thereof · CPC title

• C09J2433/00

  Presence of (meth)acrylic polymer · CPC title