Pressure-sensitive adhesive composition, pressure-sensitive adhesive layer, and pressure-sensitive adhesive sheet
Provided is a pressure-sensitive adhesive composition that makes it possible to prevent electrification of a non-antistatic protected material during peeling, is reduced in the risk of staining the protected material, and has good removability, and to provide a pressure-sensitive adhesive layer, a pressure-sensitive adhesive sheet. Specifically provided is a pressure-sensitive adhesive composition which comprises: a (meth)acryl-based polymer including, as a main component, a (meth)acryl-based monomer component having an alkyl group of 1 to 14 carbon atoms; an alkali metal salt; and an organopolysiloxane having a polyoxyalkylene side chain, wherein the (meth)acryl-based polymer has an acid value of 1.0 or less, and the total amount of the alkali metal salt and the organopolysiloxane is from 0.15 to 4 parts by weight, based on 100 parts by weight of the (meth)acryl-based polymer.
1. A pressure-sensitive adhesive composition, comprising:
a (meth)acryl-based polymer that comprises, as a main component, a (meth)acryl-based monomer component having an alkyl group of 1 to 14 carbon atoms and has an acid value of 1.0 or less;
a conductive agent, wherein the conductive agent consists of an alkali metal salt; and
an organopolysiloxane having a polyoxyalkylene side chain, wherein
the total amount of the alkali metal salt and the organopolysiloxane is from 0.15 to 4 parts by weight, based on 100 parts by weight of the (meth)acryl-based polymer, and
said organopolysiloxane having a polyoxyalkylene side chain increases the removability of said pressure-sensitive adhesive composition when attached to an adherend
wherein, when said pressure-sensitive adhesive composition is formed as a pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer has a 180° peel adhesion of 0.25 N/25 mm or less to a polarizing plate surface under conditions of 23° C. and 50% RH at a peel rate of 0.3 m/minute, and the pressure-sensitive adhesive layer has a 180° peel adhesion of 3.0 N/25 mm or less to a polarizing plate surface under conditions of 23° C. and 50% RH at a peel rate of 30 m/minute.
2. The pressure-sensitive adhesive composition according to claim 1 , wherein the organopolysiloxane is represented by the formula:
wherein R 1 represents a monovalent organic group, R 2 , R 3 , and R 4 each represent an alkylene group, or R 5 represents a hydroxyl group or an organic group, m and n each represent an integer of 0 to 1,000, provided that m and n are not simultaneously 0, and a and b each represent an integer of 0 to 100, provided that a and b are not simultaneously 0.
3. The pressure-sensitive adhesive composition according to claim 1 , wherein the alkali metal salt is a lithium salt.
4. The pressure-sensitive adhesive composition according to claim 1 , wherein the (meth)acryl-based polymer further comprises a hydroxyl group-containing (meth)acryl-based monomer component.
5. The pressure-sensitive adhesive composition according to claim 1 , wherein the (meth)acryl-based polymer further comprises 5.0% by weight or less of an alkylene oxide group-containing reactive monomer component with an average addition mole number of oxyalkylene units of 3 to 40.
6. A pressure-sensitive adhesive layer comprising a product produced by crosslinking the pressure-sensitive adhesive composition according to claim 1 .
7. A pressure-sensitive adhesive sheet, comprising a backing film and the pressure-sensitive adhesive layer according to claim 6 formed on one or both sides of the backing film.
8. The pressure-sensitive adhesive sheet according to claim 7 , wherein the backing film is an antistatic-treated plastic film.
9. The pressure-sensitive adhesive composition according to claim 2 , wherein the (meth)acryl-based polymer further comprises a hydroxyl group-containing (meth)acryl-based monomer component.
10. The pressure-sensitive adhesive composition according to claim 2 , wherein the (meth)acryl-based polymer further comprises 5.0% by weight or less of an alkylene oxide group-containing reactive monomer component with an average addition mole number of oxyalkylene units of 3 to 40.
11. A pressure-sensitive adhesive layer comprising a product produced by crosslinking the pressure-sensitive adhesive composition according to claim 2 .
12. The pressure-sensitive adhesive composition according to claim 1 , wherein a content ratio of the alkali metal salt to the organopolysiloxane by weight is from 20:80 to 50:50.
13. The pressure-sensitive adhesive composition according to claim 2 , wherein a content ratio of the alkali metal salt to the organopolysiloxane by weight is from 20:80 to 50:50.
14. A pressure-sensitive adhesive sheet, comprising a backing film and a pressure-sensitive adhesive layer formed on one or both sides of the backing film, wherein
the pressure-sensitive adhesive layer is produced by crosslinking a pressure-sensitive adhesive composition,
the pressure-sensitive adhesive layer has a 180° peel adhesion of 0.25 N/25 mm or less to a polarizing plate surface under conditions of 23° C. and 50% RH at a peel rate of 0.3 m/minute, and
the pressure-sensitive adhesive layer has a 180° peel adhesion of 3.0 N/25 mm or less to a polarizing plate surface under conditions of 23° C. and 50% RH at a peel rate of 30 m/minute
wherein the pressure-sensitive adhesive composition comprises:
a (meth)acryl-based polymer that comprises, as a main component, a (meth)acryl-based monomer component having an alkyl group of 1 to 14 carbon atoms and has an acid value of 1.0 or less;
a conductive agent, wherein the conductive agent consists of an alkali metal salt; and
an organopolysiloxane having a polyoxyalkylene side chain, wherein
the total amount of the alkali metal salt and the organopolysiloxane is from 0.15 to 4 parts by weight, based on 100 parts by weight of the (meth)acryl-based polymer, and
said organopolysiloxane having a polyoxyalkylene side chain increases the removability of said pressure-sensitive adhesive composition when attached to an adherend.