Adhesive composition and optical member using the same

Patent metadata

Field	Value
Publication number	US-9598612-B2
Application number	US-201113279734-A
Country	US
Kind code	B2
Filing date	Oct 24, 2011
Priority date	Dec 30, 2010
Publication date	Mar 21, 2017
Grant date	Mar 21, 2017

Abstract

An adhesive composition and an optical member using the same, the adhesive composition including an acrylic resin; an isocyanate cross-linking agent; and a carbodiimide cross-linking agent, wherein the adhesive composition exhibits a creeping distance of about 100 μm or less when the composition attached to a glass substrate with a bonding area of about 1.5 cm×1.5 cm is left at about 22° C. and about 50% RH for about 3 days and is subjected to a load of about 10 gf/mm 2 for about 1,000 seconds, and a storage modulus of about 1×10 5 to about 1×10 7 Pa at about 10 Hz and about 30° C. under conditions in which a sample has a thickness of about 1 mm and an elongation of about 10%.

First claim

What is claimed is:

1. An adhesive composition, comprising:
an acrylic resin;
an isocyanate cross-linking agent; and
a carbodiimide cross-linking agent, wherein:
the adhesive composition has a creeping distance of about 100 μm or less when the composition attached to a glass substrate with a bonding area of about 1.5 cm×1.5 cm is left at about 22° C. and about 50% RH for about 3 days and is subjected to a load of about 10 gf/mm 2 for about 1,000 seconds,
the adhesive composition has a storage modulus of about 1×10 5 to about 1×10 7 Pa at about 10 Hz and about 30 ° C. under conditions in which a sample has a thickness of about 1 mm and an elongation of about 10%, and
a difference between 180° peel strength (P1) and 180° Peel strength (P4) of the adhesive composition is 100 g/25 mm or less, where 180° peel strength (P1) is a 180° peel strength of a specimen measured by JIS 2107 between the adhesive composition and the glass substrate after the specimen was left for 1 day, and 180° peel strength (P4) is a 180° peel strength of the specimen measured by JIS 2107 between the adhesive composition and the glass substrate after the specimen was left for 4 days wherein the adhesive composition includes:
100 parts by weight of the acrylic resin;
about 1 to about 30 parts by weight of the isocyanate cross-linking agent;
about 0.001 to about 1 part by weight of the carbodiimide cross-linking agent; and wherein a weight ratio of the isocyanate cross-linking agent to the carbodiimide cross-linking agent is about 500:1 to about 3,000:1.

2. The adhesive composition as claimed in claim 1 , wherein the acrylic resin includes a (meth)acrylate copolymer, the (meth)acrylate copolymer including about 0.01 to about 5 wt % of repeating units of a hydroxyl group containing monomer.

3. The adhesive composition as claimed in claim 1 , wherein the acrylic resin includes:
a first (meth)acrylate copolymer including less than about 0.01 wt % of repeating units of a hydroxyl group containing monomer, and
a second (meth)acrylate copolymer including about 0.01 to about 5 wt % of repeating units of a hydroxyl group containing monomer.

4. The adhesive composition as claimed in claim 3 , wherein the acrylic resin includes:
about 85 to about 99 wt % of the first (meth)acrylate copolymer, and
about 1 to about 15 wt % of the second (meth)acrylate copolymer.

5. The adhesive composition as claimed in claim 3 , wherein:
the first (meth)acrylate copolymer has a weight average molecular weight of about 1,000,000 to about 2,000,000 g/mol, and
the second (meth)acrylate copolymer has a weight average molecular weight of about 500,000 to about 1,500,000 g/mol.

6. The adhesive composition as claimed in claim 3 , wherein:
the first (meth)acrylate copolymer is polymerized from a monomer mixture including:
about 85 to about 99.99 wt % of C1 to C20 alkyl (meth)acrylate,
less than about 0.01 wt % of a hydroxyl group containing monomer, and
about 0.01 to about 15 wt % of a carboxyl group containing monomer, and

the second (meth)acrylate copolymer is polymerized from a monomer mixture including:
about 90 to about 99 wt % of C1 to C20 alkyl (meth)acrylate,
about 0.01 to about 5 wt % of a hydroxyl group containing monomer, and
about 0.1 to about 5 wt % of a carboxyl group containing monomer.

7. The adhesive composition as claimed in claim 1 , wherein the acrylic resin has a weight average molecular weight of about 1,500,000 to about 3,000,000 g/mol.

8. The adhesive composition as claimed in claim 1 further comprising about 0.01 to 20 parts by weight of a silane coupling agent.

9. The adhesive composition as claimed in claim 1 , wherein the adhesive composition includes:
100 parts by weight of the acrylic resin;
greater than about 10 parts by weight to less than about 30 parts by weight of the isocyanate cross-linking agent; and
about 0.005 to about 0.1 parts by weight of the carbodiimide cross-linking agent.

10. An optical member, comprising:
an optical film; and
an adhesive layer prepared from the adhesive composition as claimed in claim 1 , the adhesive layer being on one or more sides of the optical film.

11. The optical member as claimed in claim 10 , wherein the optical member has a 180° peel strength of about 250 to 600 gf/25mm between an adhesive and a glass substrate at a tensile rate of about 300 mm/min by JIS 2107 when the optical member is left at about 35° C. and about 45% RH for about 1 day and then stabilized at about 25° C. for about 12 hours.

12. An adhesive composition, comprising:
100 parts by weight of an acrylic resin, the acrylic resin including a (meth)acrylate copolymer including about 0.01 to about 5 wt % of repeating units of a hydroxyl group containing monomer;
about 1 to about 30 parts by weight of an isocyanate cross-linking agent; and
a carbodiimide cross-linking agent in an amount such that a weight ratio of the isocyanate cross-linking agent to the carbodiimide cross-linking agent is about 500:1 to about 3,000:1,
wherein a difference between 180° peel strength (P1) and 180° peel strength (P4) is 100 g/25mm or less (where, 180° peel strength (P1) is a 180° peel strength of a specimen measured by JIS 2107 between the adhesive composition and the glass substrate after the specimen was left for 1 day, 180° peel strength (P4) is a 180° peel strength of the specimen measured by JIS 2107 between the adhesive composition and the glass substrate after the specimen was left for 4 days).

Assignees

• Ki Hee Yeon
• Jeong Woo Jin
• Cheil Ind Inc

Inventors

• Ki Hee Yeon
• Jeong Woo Jin

Classifications

• C08K5/0025

  Crosslinking or vulcanising agents; including accelerators · CPC title

• C09J7/38

  Pressure-sensitive adhesives [PSA] · CPC title

• Y10T428/2891

  including addition polymer from alpha-beta unsaturated carboxylic acid [e.g., acrylic acid, methacrylic acid, etc.] Or derivative thereof · CPC title

• Y10T428/2848

  Three or more layers · CPC title

• C08K2201/014

  Additives containing two or more different additives of the same subgroup in C08K · CPC title