TOUCH PANEL

• US 20140134433A1
• Filed: 01/17/2014
• Published: 05/15/2014
• 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
• Granted Patent: US 9,550,926 B2
• Time in Patent Office: Days
• US Class Current: 428/355.AC
• 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; and

a pressure-sensitive adhesive layer attached to the base, which comprises 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.

2. The touch panel according to claim 1, wherein the isobornyl (meth)acrylate is isobornyl acrylate.

3. The touch panel according to claim 1, wherein the methyl (meth)acrylate is methyl acrylate.

4. The touch panel according to claim 1, wherein a conductor thin film is further formed on at least one surface of the base, and the pressure-sensitive adhesive layer is directly attached to the conductor thin film.

5. The touch panel according to claim 1, wherein the acryl polymer has a weight average molecular weight of 200,000 to 2,500,000.

6. 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:

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

8. The touch panel according to claim 1, wherein the pressure-sensitive adhesive layer further comprises a thiol compound.

9. The touch panel according to claim 1, wherein the pressure-sensitive adhesive layer further comprises a thiol polymer derived from an acryl monomer and a thiol compound.

10. The touch panel according to claim 8, wherein the thiol compound is at least one of compounds represented by Formulas 2 to 5:

11. The touch panel according to claim 10, wherein R¹ is a linear or branched alkyl group having 3 to 20 carbon atoms.

12. The touch panel according to claim 1, wherein the pressure-sensitive adhesive layer has a peel strength with respect to a polycarbonate sheet of 1,900 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 an ITO electrode of 10% or less.

19. The touch panel according to claim 9, wherein the thiol compound is at least one of compounds represented by Formulas 2 to 5:

20. The touch panel according to claim 19, wherein R¹ is a linear or branched alkyl group having 3 to 20 carbon atoms.

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

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 as polymerization units.

14. 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 13.

15. A method of preparing a pressure-sensitive adhesive composition for a touch panel, comprising:

(1) preparing a monomer mixture containing 5 to 30 parts by weight of isobornyl (meth)acrylate and 5 to 40 parts by weight of methyl (meth)acrylate; and

(2) initiating polymerization of the monomer mixture by inputting an initiator.

16. The method according to claim 15, wherein a thiol compound is input together with the initiator.

17. The method according to claim 15, wherein the thiol compound is input after the initiation of polymerization before the termination of polymerization.

18. The method according to claim 15, wherein the thiol compound is input after the termination of polymerization.