Touch panel

• US 9,550,926 B2
• Filed: 01/17/2014
• Issued: 01/24/2017
• Est. Priority Date: 07/19/2011
• Status: Active Grant

• Current Assignee: LG Chem Limited (LG Corporation)
• Original Assignee: LG Chem Limited (LG Corporation)
• Inventors: Park, Min Soo, Yang, Se Woo, Chang, Suk Ky
• Primary Examiner(s): DESAI, ANISH P
• Application Number:
  US14/158,228
• Publication Number:
  US 20140134433A1
• Time in Patent Office: 1,103 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: C09J 133/12 Homopolymers or copolymers of methyl methacrylate
• CPC Class Codes: Y10T 428/2891 including addition polymer from alpha-beta unsaturated carboxylic acid [e.g., acrylic acid, methacrylic acid, etc.] Or derivative thereof

Abstract

Provided is a touch panel. The touch panel includes a base and a pressure-sensitive adhesive layer attached to the base and including an acryl-based polymer containing an acryl polymer containing 5 to 30 parts by weight of isobornyl (meth)acrylate, and 5 to 40 parts by weight of methyl (meth)acrylate in a polymerized form. Accordingly, it can effectively inhibit penetration of oxygen, moisture or other impurities at an interface between the base and the pressure-sensitive adhesive layer, or at an interface between a conductor thin film and the pressure-sensitive adhesive layer, and prevent degradation in optical properties such as visibility, etc. due to bubbles generated at the pressure-sensitive adhesive interface. In addition, when the pressure-sensitive adhesive layer is directly attached to the conductor thin film and even exposed to severe conditions such as high temperature or high temperature and high humidity, a change in the resistance of the conductor thin film may be effectively inhibited, and thus the touch panel can be stably driven for a long time.

Claims

1. A touch panel, comprising:

a base including an indium tin oxide (ITO) film formed on at least one surface thereof; and

a pressure-sensitive adhesive layer directly attached to the ITO film on the base, which comprises an acryl polymer containing 5 to 28 parts by weight of isobornyl acrylate monomer and 5 to 35 parts by weight of methyl acrylate monomer in a polymerized form wherein the acryl polymer has a weight average molecular weight of 750,000 to 2,500,000,

wherein the pressure-sensitive adhesive layer has a peel strength with respect to a polycarbonate sheet of 2,500 g/25 mm or more at a peel angle of 180 degrees, a peel rate of 300 mm/min and at room temperature, and a resistance change ratio of the indium tin oxide (ITO) film of 6% or less,

wherein the pressure-sensitive adhesive layer completely covers the ITO film,

wherein the pressure-sensitive adhesive layer comprises a thiol compound or a thiol polymer derived from an acryl monomer and a thiol compound, and,

wherein the thiol compound is at least one of compounds represented by Formulas 2 to 5;

2. The touch panel according to claim 1, wherein the acryl polymer further comprises 30 to 80 parts by weight of a monomer represented by Formula 1, and 0.01 to 20 parts by weight of a copolymerizable monomer having a crosslinkable functional group:

3. The touch panel according to claim 1, wherein the pressure-sensitive adhesive layer further comprises a multifunctional crosslinking agent crosslinking the acryl polymer.

4. A pressure-sensitive adhesive composition for a touch panel, comprising:

an acryl polymer containing 5 to 28 parts by weight of isobornyl acrylate monomer, and 5 to 35 parts by weight of methyl acrylate monomer in a polymerized form, and a thiol compound,

wherein the acryl polymer has a weight average molecular weight of 750,000 to 2,500,000,

wherein the touch panel comprises a base including an indium tin oxide (ITO) film formed on at least one surface thereof; and

a pressure-sensitive adhesive layer directly attached to the ITO film on the base,

wherein the pressure-sensitive adhesive layer is formed from the pressure sensitive adhesive composition, and completely covers the ITO film,

wherein the pressure-sensitive adhesive layer has a peel strength with respect to a polycarbonate sheet of 2,500 g/25 mm or more at a peel angle of 180 degrees, a peel rate of 300 mm/min and at room temperature, and a resistance change ratio of the ITO film of 6% or less, and

wherein the thiol compound is at least one of compounds represented by Formulas 2 to 5;

5. A double-sided pressure-sensitive adhesive tape for a touch panel, comprising a pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition according to claim 4.