Pressure-sensitive adhesive compositions, polarizers and liquid crystal displays comprising the same

Patent metadata

Field	Value
Publication number	US-9399695-B2
Application number	US-81222909-A
Country	US
Kind code	B2
Filing date	Jan 6, 2009
Priority date	Jan 11, 2008
Publication date	Jul 26, 2016
Grant date	Jul 26, 2016

Abstract

The present invention relates to pressure-sensitive adhesive compositions which contain (A) hydroxyl group and alkylene oxide group containing acrylic copolymer and (B) a multifunctional isocyanate-based hardener, and form interpenetrating network structures when hardened, and polarizers and liquid crystal displays comprising the same. The pressure-sensitive adhesive compositions of the present invention exhibit superior durability, reliability, and workability and effectively prevent light leakage under high temperature and/or high humidity conditions. Particularly, the present invention provides pressure-sensitive adhesive compositions capable of significantly suppressing light leakage even in large size display devices, and polarizers and liquid crystal displays comprising the same.

First claim

The invention claimed is:

1. A pressure-sensitive adhesive polarizer, comprising: a polarizing film or a polarizing device; and
a pressure-sensitive adhesive layer to be attached on a liquid crystal panel, the pressure-sensitive adhesive layer being formed on one or both sides of the polarizing film or device, and comprising a cured pressure-sensitive adhesive composition,
wherein the pressure-sensitive adhesive composition includes an interpenetrating polymer network in a cured state,
wherein the pressure-sensitive adhesive composition comprises (A) an acrylic copolymer; (B) a multi-functional isocyanate hardener; (C) a multi-functional acrylate having a cyclic structure and (D) a photoinitiator, wherein an adhesion strength of the polarizer to alkali-free glass is 200 to 500 gf/25 mm, wherein the (A) acrylic copolymer comprises (meth)acrylic acid ester monomer; (meth)acrylic acid alkylene oxide adduct; and a monomer containing a hydroxy group, and
wherein the (meth)acrylic acid alkylene oxide adduct is included in an amount of 2 to 15 parts by weight, relative to 100 parts by weight of the (A) acrylic copolymer.

2. The pressure-sensitive adhesive polarizer according to claim 1 ,
wherein a gel content as represented by General Formula 1 is 80% to 99%:
Gel Content (%)= B/A ×100  General Formula 1

wherein A represents weight of the pressure-sensitive adhesive layer, and B represents dry weight of insoluble content after depositing the pressure-sensitive adhesive layer in ethyl acetate at 23° C. for 48 hours.

3. The pressure-sensitive adhesive polarizer according to claim 1 ,
wherein the (A) acrylic copolymer has a weight average molecular weight of 1,000,000 or more.

4. The pressure-sensitive adhesive polarizer according to claim 1 ,
wherein the (meth)acrylic acid ester monomer is one or more selected from the group consisting of ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, sec-butyl (meth)acrylate, pentyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-ethylbutyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, lauryl (meth)acrylate and tetradecyl (meth)acrylate.

5. The pressure-sensitive adhesive polarizer according to claim 1 ,
wherein the (meth)acrylic acid alkylene oxide adduct is one or more selected from the group consisting of alkoxy alkyleneglycol (meth)acrylic acid ester, alkoxy dialkyleneglycol (meth)acrylic acid ester, alkoxy trialkyleneglycol (meth)acrylic acid ester, alkoxy tetraalkyleneglycol (meth)acrylic acid ester, phenoxy alkyleneglycol (meth)acrylic acid ester, phenoxy dialkyleneglycol (meth)acrylic acid ester, phenoxy trialkyleneglycol (meth)acrylic acid ester and phenoxy tetraalkyleneglycol (meth)acrylic acid ester.

6. The pressure-sensitive adhesive polarizer according to claim 1 ,
wherein the monomer containing a hydroxyl group is one or more selected from the group consisting of hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 2-hydroxyethyleneglycol (meth)acrylate and 2-hydroxypropyleneglycol (meth)acrylate.

7. The pressure-sensitive adhesive polarizer according to claim 1 ,
wherein the (A) acrylic copolymer further comprises a monomer represented in Formula 1:

wherein R 1 , R 2 and R 3 represents independently hydrogen or alkyl, R 4 represents cyano; phenyl unsubstituted or substituted with alkyl; acetyloxy; or COR 5 , where R 5 represents amino unsubstituted or substituted with alkyl or alkoxyalkyl; or glycidyloxy.

8. The pressure-sensitive adhesive polarizer according to claim 1 ,
wherein the (B) multi-functional isocyanate hardener is one or more selected from the group consisting of tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, tetramethylxylene diisocyanate, naphthalene diisocyanate and a reactant of any one of the foregoing with polyol.

9. The pressure-sensitive adhesive polarizer according to claim 1 ,
wherein the pressure-sensitive adhesive composition comprises the (B) multi-functional isocyanate hardener in an amount of 0.01 to 5 parts by weight, relative to 100 parts by weight of the (A) acrylic copolymer.

10. The pressure-sensitive adhesive polarizer according to claim 1 ,
wherein the pressure-sensitive adhesive composition comprises 5 to 40 parts by weight of the (C) multi-functional acrylate, relative to 100 parts by weight of the (A) acrylic copolymer.

11. The pressure-sensitive adhesive polarizer according to claim 10 ,
wherein the pressure-sensitive adhesive composition comprises 0.01 to 20 parts by weight of the (D) photoinitiator, relative to 100 parts by weight of the (C) multi-functional acrylate.

12. The pressure-sensitive adhesive polarizer according to claim 1 ,
wherein the (C) multi-functional acrylate is one or more selected from the group consisting of trifunctional acrylate, tetrafunctional acrylate, pentafunctional acrylate and hexafunctional acrylate.

13. The pressure-sensitive adhesive polarizer according to claim 1 ,
wherein the (D) photoinitiator is one or more selected from the group consisting of benzoin, benzoin methylether, benzoin ethylether, benzoin isopropylether, benzoin n-butylether, benzoin isobutylether, acetophenone, dimethylamino acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl- 1-phenylpropan-1-one, 1-hydroxycyclohexylphenylketone, 2-methyl-1-[4-(methylthio)phenyl] -2-morpholino-propan-1-one, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)ketone, benzophenone, p-phenylbenzophenone, 4,4′-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethylketal, acetophenone dimethylketal, p-dimethylamino benzoic acid ester, oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone] and 2,4,6-trimethylbenzo yl-diphenyl-phosphineoxide.

14. The pressure-sensitive adhesive polarizer according to claim 1 ,
wherein the pressure-sensitive adhesive composition further comprises a silane coupling agent having an acetoacetate group or a β-cyanoacetyl group in an amount of 0.01 to 1 parts by weight, relative to 100 parts by weight of the (A) acrylic copolymer.

15. The pressure-sensitive adhesive polarizer according to claim 1 ,
wherein the pressure-sensitive adhesive composition further comprises a tackifier resin in an amount of 1 to 100 parts by weight, relative to 100 parts by weight of the (A) acrylic copolymer.

16. The pressure-sensitive adhesive polarizer according to claim 1 , further comprising a protective film formed on one or both sides of the polarizing film or polarizing device, the protective film(s) being one or more selected from the group consisting of a film, a polyester film, a polyether sulphone film and a polyolefin film.

17. The pressure-sensitive adhesive polarizer according to claim 1 , wherein an adhesion strength of the polarizer is 200 to 500 gf/25 mm and wherein the adhesion strength is measured under a condition in a detachment speed of 300 mm/min and a detachment angle of 180 degrees after adhering the polarizer in a size of 25 mm×100 mm (width×length) to an alkali-free glass using a laminator, pressing the resulted produc

Assignees

• Kim No Ma
• Hwang In Ho
• Ha Jeong Min
• Yoon Sung Soo
• Kim Sung Su
• Bae Sang Jo
• Lg Chemical Ltd

Inventors

• Kim No Ma
• Hwang In Ho
• Ha Jeong Min
• Yoon Sung Soo
• Kim Sung Su
• Bae Sang Jo

Classifications

• G02F1/133528

  Polarisers · CPC title

• G02B1/111

  using layers comprising organic materials · CPC title

• C08G18/673

  containing two or more acrylate or alkylacrylate ester groups · CPC title

• C08G18/6229 Primary

  Polymers of hydroxy groups containing esters of acrylic or methacrylic acid with aliphatic polyalcohols · CPC title

• B32B2457/202

  LCD, i.e. liquid crystal displays · CPC title