ADHESIVE COMPOSITION FOR USE IN BONDING OF POLARIZING PLATE

• US 20110086980A1
• Filed: 09/17/2010
• Published: 04/14/2011
• Est. Priority Date: 10/09/2009
• Status: Active Grant

• Current Assignee: NAN YA Plastics Corporation
• Original Assignee: NAN YA Plastics Corporation
• Inventors: Wu, Hung-Hsun, Fung, Dein-Run, Hsu, Sen-Huang, Juang, Huei-Jiun
• Granted Patent: US 8,314,186 B2
• Time in Patent Office: Days
• US Class Current: 525/72
• CPC Class Codes: C08F 220/06 Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof
• CPC Class Codes: C08F 220/1804 C4-(meth)acrylate, e.g. butyl (meth)acrylate, isobutyl (meth)acrylate or tert-butyl (meth)acrylate
• CPC Class Codes: C08F 220/1808 C8-(meth)acrylate, e.g. isooctyl (meth)acrylate or 2-ethylhexyl (meth)acrylate
• CPC Class Codes: C08F 220/20 of polyhydric alcohols or phenols , e.g. 2-hydroxyethyl (meth)acrylate or glycerol mono-(meth)acrylate
• CPC Class Codes: C08F 230/085 the monomer being a polymerisable silane, e.g. (meth)acryloyloxy trialkoxy silanes or vinyl trialkoxysilanes
• CPC Class Codes: C08G 18/73 acyclic
• CPC Class Codes: C09J 133/066 containing -OH groups
• CPC Class Codes: C09J 175/04 Polyurethanes

Abstract

An adhesive composition for use in bonding of a polarizing plate is prepared from acrylic-based polymer graft-polymerized and modified by a reactive silane coupling agent with a specific grafting position and an ordinary cross-linking agent. Compared with unmodified acrylic-based copolymers, the adhesive composition thus synthesized demonstrates high adhesion property, cohesion property, elasticity property and high durability and, when used in bonding of the polarizing plate, flexibly follows dimensional changes of the polarizing plate in a high-temperature high-humidity atmosphere, alleviates the phenomenon where the polarizing plate demonstrates uneven distribution of residual stress due to dimensional changes of the polarizing plate, and prevents light leakage and uneven color which might otherwise occur to the polarizing plate due to the aging, cracking, or peeling of a conventional adhesive.

Claims

1. An adhesive composition prepared from 100 parts by weight of a component (A) and 0.01 to 1 part by weight of a component (B), wherein

the component (A) is an acrylic-based polymer graft-polymerized and modified by a reactive silane coupling agent and has a weight-average molecular weight of between 700,000 and 1,200,000, and, according to a total weight of the acrylic-based polymer, the component (A) is synthesized by polymerization of:

a. 50˜

98% of alkyl group-containing (meth)acrylic acid;

b. 1˜

10% of hydroxyl group-containing (meth)acrylic acid;

c. 0.1˜

5% of carboxyl group-containing (meth)acrylic acid; and

d. 0.01˜

2% of reactive silane coupling agent; and

the component (B) is a cross-linking agent.

2. The adhesive composition of claim 1, wherein the alkyl group-containing (meth)acrylic acid is one, or a mixture of at least two, selected from the group consisting of methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, lauryl (meth)acrylate, octadecyl (meth)acrylate, cyclohexyl (meth)acrylate, methoxyethyl (meth)acrylate, and ethoxymethyl (meth)acrylate.

3. The adhesive composition of claim 1, wherein the hydroxyl group-containing (meth)acrylic acid is one selected from the group consisting of 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, chloro-2-hydroxypropyl acrylate, diethylene glycol mono(meth)acrylate, and allyl alcohol.

4. The adhesive composition of claim 1, wherein the carboxyl group-containing (meth)acrylic acid is one selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, butenoic acid, maleic acid, fumaric acid, and maleic anhydride.

5. The adhesive composition of claim 1, wherein the silane coupling agent is one, or a mixture of at leaste two, selected from the group consisting of γ

-methacryloxypropyltrimethoxysilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, and ethylene-containing epoxy silane.

6. The adhesive composition of claim 1, wherein the cross-linking agent is one selected from the group consisting of isocyanate-based compound, epoxy compound, amine compound, metal-chelating compound, and aziridine compound.

7. The adhesive composition of claim 6, wherein the cross-linking agent is in an amount of 0.01 to 0.6 part by weight based on 100 parts by weight of the component (A).

8. The adhesive composition of claim 6, wherein the cross-linking agent is in an amount of 0.05 to 0.5 part by weight based on 100 parts by weight of the component (A).