Adhesive film for polarizing plate, polarizing plate and optical display comprising the same

Patent metadata

Field	Value
Publication number	US-2017145262-A1
Application number	US-201615360557-A
Country	US
Kind code	A1
Filing date	Nov 23, 2016
Priority date	Nov 24, 2015
Publication date	May 25, 2017
Grant date	—

Abstract

An adhesive film for polarizing plates, a polarizing plate including the same, and an optical display including the same are provided. An adhesive film for polarizing plates is formed of an adhesive composition including a (meth)acrylic copolymer and a cellulose ester binder. The (meth)acrylic copolymer contains an alkyl group, a hydroxyl group, an alicyclic group, and a hetero-alicyclic group. The adhesive film has a modulus at 30 ° C. of about 100,000 Pa or more.

First claim

What is claimed is:

1 . An adhesive film for polarizing plates formed of an adhesive composition comprising: a (meth)acrylic copolymer containing an alkyl group, a hydroxyl group, an alicyclic group, and a hetero-alicyclic group; and a cellulose ester binder, the adhesive film having a modulus at 30° C. of about 100,000 Pa or more.

2 . The adhesive film for polarizing plates according to claim 1 , wherein the adhesive film has a creep of about 200 μm or less at 25° C., a modulus ratio of about 1.5 or more as represented by Equation 1 and a modulus at 30° C. of about 100,000 Pa or more:
Modulus ratio= A/B,   Equation 1

where A is the modulus of the adhesive film at 30° C. and B is the modulus of the adhesive film at 120° C.

3 . The adhesive film for polarizing plates according to claim 1 , wherein the adhesive has a creep of about 250 μor more at 85° C.

4 . The adhesive film for polarizing plates according to claim 1 , wherein the adhesive film has a modulus of about 80,000 Pa or less at 120° C.

5 . The adhesive film for polarizing plates according to claim 1 , wherein the (meth)acrylic copolymer is a copolymer of a monomer mixture comprising an alkyl group-containing (meth)acrylic monomer, a hydroxyl group-containing (meth)acrylic monomer, an alicyclic group-containing (meth)acrylic monomer, and a hetero-alicyclic group-containing (meth)acrylic monomer.

6 . The adhesive film for polarizing plates according to claim 5 , wherein the alicyclic group-containing (meth)acrylic monomer is present in an amount of about 1 mol % to about 30 mol % in the monomer mixture.

7 . The adhesive film for polarizing plates according to claim 5 , wherein the hetero-alicyclic group-containing (meth)acrylic monomer is present in an amount of about 1 mol % to about 20 mol % in the monomer mixture.

8 . The adhesive film for polarizing plates according to claim 5 , wherein the alicyclic group-containing (meth)acrylic monomer and the hetero-alicyclic, group-containing (meth)acrylic monomer are present in a mole ratio (alicyclic group-containing (meth)acrylic monomer:hetero-alicyclic group-containing (meth)acrylic monomer) of about 1:0.5 to about 1:40 in the monomer mixture.

9 . The adhesive film for polarizing plates according to claim 5 , wherein the alkyl group-containing (meth)acrylic monomer comprises an unsubstituted C 4 to C 12 alkyl group-containing (meth)acrylic acid ester alone or a mixture of the unsubstituted C 4 to C 12 alkyl group-containing (meth)acrylic acid ester and an unsubstituted C 15 to C 25 alkyl group-containing (meth)acrylic acid ester.

10 . The adhesive film for polarizing plates according to claim 1 , wherein the cellulose ester binder comprises at least one of cellulose acetate butyrate, cellulose acetate proprionate, cellulose acetate, and cellulose propionate.

11 . The adhesive film for polarizing plates according to claim 1 , wherein he cellulose ester binder is present in an amount of about 0.1 parts by weight to about 30 parts by weight relative to 100 parts by weight of the (meth)acrylic copolymer.

12 . The adhesive film for polarizing plates according to claim 1 , wherein the adhesive composition further comprises a curing agent.

13 . The adhesive film for polarizing plates according to claim 12 , wherein the curing agent comprises at least one of an isocyanate curing agent, a metal chelate curing agent, and an aziridine curing agent.

14 . The adhesive film for polarizing plates according to claim 1 , wherein the meth)acrylic copolymer comprises a tertiary amine group.

15 . The adhesive film for polarizing plates according to claim 14 , wherein the (meth)acrylic copolymer is a copolymer of a monomer mixture comprising about 40 mol % to about 95 mol % of an alkyl group-containing (meth)acrylic monomer, about 0.1 mol % to about 20 mol % of a hydroxyl group-containing (meth)acrylic monomer, about 1 mol % to about 30 mol % of an alicyclic group-containing (meth)acrylic monomer, about 1 mol % to about 20 mol % of a hetero-alicyclic group-containing (meth)acrylic monomer, and about 0.001 mol % to about 15 mol % of a tertiary amine group-containing (meth)acrylic monomer.

16 . The adhesive film for polarizing plates according to claim 1 , wherein the (meth)acrylic copolymer comprises a tertiary amine group and a carboxylic acid group.

17 . The adhesive film for polarizing plates according to claim 16 , wherein the (meth)acrylic copolymer is a copolymer of a monomer mixture comprising about 40 mol % to about 95 mol % of an alkyl group-containing (meth)acrylic monomer, about 0.1 mol % to about 20 mol % of a hydroxyl group-containing (meth)acrylic monomer, about 1 mol % to about 30 mol of an alicyclic group-containing (meth)acrylic monomer, about 1 mol % to about 20 mol % of a hetero-alicyclic group-containing (meth)acrylic monomer, about 0.001 mol % to about 15 mol % of a tertiary amine group-containing (meth)acrylic monomer, and about 0.001 mol % to about 10 mol % of a carboxylic acid group-containing (meth)acrylic monomer.

18 . A polarizing plate comprising an adhesive film, a polarizer stacked on the adhesive film, and an optical film stacked on the polarizer,
wherein the polarizing plate has a pencil hardness of 2H or more, and the adhesive film has a creep at 85° C. of about 250 μm or more and a creep at 25° C. of about 200 μm or less.

19 . The polarizing plate according to claim 18 , wherein the adhesive film comprises an adhesive film formed of an adhesive composition comprising: a (meth)acrylic copolymer containing an alkyl group, a hydroxyl group, an alicyclic group, and a hetero-alicyclic group; and a cellulose ester binder, the adhesive film having a modulus at 30° C. of about 100,000 Pa or more.

20 . An optical display comprising the adhesive film for polarizing plates according to claim 1 .

Assignees

• Samsung Sdi Co Ltd

Inventors

• Nam Irina
• Kim Dae Yun
• Kim Young Jong
• Kim Won
• Han In Cheon

Classifications

• B32B2307/548

  Creep · CPC title

• B32B2307/702

  Amorphous · CPC title

• C09J2401/006

  in the substrate · CPC title

• B32B27/325

  comprising polycycloolefins · CPC title

• B32B2307/536

  Hardness · CPC title