Liquid optically clear photo-curable adhesive

Patent metadata

Field	Value
Publication number	US-10100238-B2
Application number	US-201414550403-A
Country	US
Kind code	B2
Filing date	Nov 21, 2014
Priority date	May 22, 2012
Publication date	Oct 16, 2018
Grant date	Oct 16, 2018

Abstract

A liquid photo-curable adhesive composition comprising:
(a) 5 to 30 wt % of urethane acrylate, (b) 30 to 80 wt % of plasticizer, (c) 0.02 to 5 wt % of photo initiator, (d) 0 to 30 wt % of acrylate monomers and/or oligomer,

is described.

First claim

What is claimed is:

1. A liquid photo-curable adhesive composition comprising:
(a) 5 to 30 wt % of urethane acrylate, having a T g value from −80° C. to −10° C., and a viscosity ranging from 5,000 to 500,000 mPa at 25° C. at a shear rate of 2.55 s −1 ,
(b) 30 to 80 wt % of plasticizer,
(c) 0.02 to 5 wt % of photo initiator,
(d) 1 to 30 wt % of acrylate monomers and/or acrylate oligomer, wherein the acrylate oligomer has a T g value from −80° C. to 100° C.,

wherein the hardness of the cured adhesive is 0 to 30 (shore 00), determined in accordance with ASTM D 2240, wherein the elastic modulus of the cured adhesive is <5.0·10 4 Pa, determined using photorheometry, wherein the shrinkage of the cured adhesive is <1.5%, determined using photorheometry.

2. Adhesive composition according to claim 1 , wherein the urethane acrylate is an aliphatic polyether urethane acrylate.

3. Adhesive composition according to claim 1 , wherein the plasticizer is selected from the group consisting of polyisoprene resin, polybutadiene resin, hydrogenated polybutadiene, xylene polymer, hydroxyl-terminated polybutadiene and hydroxyl-terminated polyolefin.

4. Adhesive composition according to claim 1 , wherein the photo initiator is selected from the group consisting of 2,2-dimethoxyl-1,2-diphenylethyl-1-ketone; trimethylbenzoyldi-phenyl oxyphosphate; 1-hydroxylcyclohexyl benzophenone; 2-methyl-1-[4-methylthiophenyl]-2-dimethylthio-propyl-1-ketone and combinations thereof.

5. Adhesive composition according to claim 1 comprising:
(a) 10 to 25 wt % of the urethane acrylate,
(b) 30 to 70 wt % of the plasticizer,
(c) 1.2 to 3.5 wt % of the photo initiator, and
(d) 4 to 19 wt % of the acrylate monomers.

6. Adhesive composition according to claim 1 , which comprises additional ingredients selected from the group consisting of tackifier, antifoaming agent, antioxidant, and adhesion promoter.

Assignees

• Henkel IP & Holding GmbH
• Henkel Ag & Co Kgaa

Inventors

• Lu Daniel
• Kanari Masao
• Sawanobori Junichi

Classifications

• C09J2203/318

  for the production of liquid crystal displays · CPC title

• C09J4/00 Primary

  Adhesives based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond {; adhesives, based on monomers of macromolecular compounds of groups C09J183/00 - C09J183/16} · CPC title

• B32B38/0008

  Electrical discharge treatment, e.g. corona, plasma treatment; wave energy or particle radiation (heat treatment B32B38/0036) · CPC title

• C09J5/00

  Adhesive processes in general; Adhesive processes not provided for elsewhere, e.g. relating to primers · CPC title

• B32B2457/208

  Touch screens · CPC title