Adhesive, adhesive layer, and adhesive sheet

Patent metadata

Field	Value
Publication number	US-9657197-B2
Application number	US-201214348170-A
Country	US
Kind code	B2
Filing date	Sep 12, 2012
Priority date	Sep 30, 2011
Publication date	May 23, 2017
Grant date	May 23, 2017

Abstract

A pressure-sensitive adhesive of the invention include a (meth)acryl-based polymer obtained by polymerization of a monomer component including 30 to 99.5% by weight of an alkyl (meth)acrylate having an alkyl group of 10 to 18 carbon atoms at an ester end and 0.5 to 50% by weight of a cyclic nitrogen-containing monomer. The pressure-sensitive adhesive has a satisfactory level of adhesive performance and can form a pressure-sensitive adhesive layer with a lower dielectric constant and reliable moisture resistance.

First claim

The invention claimed is:

1. A pressure-sensitive adhesive, comprising a (meth)acryl-based polymer obtained by solution polymerization or radiation polymerization of a monomer component including 30 to 99.5% by weight of an alkyl (meth)acrylate having a branched alkyl group of 14 to 18 carbon atoms at an ester end, 0.5 to 50% by weight of a cyclic nitrogen-containing monomer and 0.5 to 49% by weight of an alkyl (meth)acrylate having an alkyl group of 1 to 9 carbon atoms at an ester end,
wherein the alkyl (meth)acrylate having a branched alkyl group of 14 to 18 carbon atoms at an ester end is a t-butyl group included isostearyl acrylate represented by the following formula:

2. The pressure-sensitive adhesive according to claim 1 ,
wherein the monomer component further includes 0.5% by weight or more of at least one functional group-containing monomer selected from a carboxyl group-containing monomer, a hydroxyl group-containing monomer, and a cyclic ether group-containing monomer.

3. The pressure-sensitive adhesive according to claim 1 ,
wherein the monomer component further includes 0.5% or more by weight of an alkyl (meth)acrylate having a cyclic alkyl group at an ester end.

4. The pressure-sensitive adhesive according to claim 1 ,
wherein the monomer component further contains 3% or less by weight of a polyfunctional monomer.

5. The pressure-sensitive adhesive according to claim 1 , further comprising 0.01 to 5 parts by weight of a crosslinking agent based on 100 parts by weight of the (meth)acryl-based polymer.

6. The pressure-sensitive adhesive according to claim 1 , which is for use on an optical member.

7. A pressure-sensitive adhesive layer obtained from the pressure-sensitive adhesive according to claim 1 .

8. The pressure-sensitive adhesive layer according to claim 7 , which has a relative dielectric constant of 3.5 or less at a frequency of 100 kHz.

9. The pressure-sensitive adhesive layer according to claim 7 which has a gel fraction of 20 to 98% by weight.

10. The pressure-sensitive adhesive layer according to claim 7 , which has a haze of 2% or less when having a thickness of 25 μm.

11. The pressure-sensitive adhesive layer according to claim 7 , which has a total light transmittance of 90% or more.

12. The pressure-sensitive adhesive layer according to claim 7 , which is for use on an optical member.

13. A pressure-sensitive adhesive sheet, comprising: a support; and the pressure-sensitive adhesive layer according to claim 7 formed on at least one side of the support.

14. The pressure-sensitive adhesive sheet according to claim 13 , which has an adhesive strength of 0.5 N/20 mm or more to alkali glass at a peel angle of 90° and a peel rate of 300 mm/minute.

15. The pressure-sensitive adhesive sheet according to claim 13 , which is for use on an optical member.

16. The pressure-sensitive adhesive sheet claim 13 , which is a pressure-sensitive adhesive optical member comprising an optical member as the support and the pressure-sensitive adhesive layer provided on at least one side of the optical member.

Assignees

• Higashi Masatsugu
• Shigetomi Kiyoe
• Shitara Koji
• Tanaka Akiko
• Kamiya Katsuhiko
• Iseki Azusa
• Nitto Denko Corp

Inventors

• Higashi Masatsugu
• Shigetomi Kiyoe
• Shitara Koji
• Tanaka Akiko
• Kamiya Katsuhiko
• Iseki Azusa

Classifications

• C09J133/14

  of esters containing halogen, nitrogen, sulfur or oxygen atoms in addition to the carboxy oxygen · CPC title

• B32B2307/202

  Conductive · CPC title

• B32B7/12

  using interposed adhesives or interposed materials with bonding properties · CPC title

• B32B2307/516

  mono-axially · CPC title

• B32B2457/204

  Plasma displays · CPC title