Acrylic pressure sensitive adhesive compositions

1. Acrylic pressure sensitive adhesive composition for a polarizer or a protective film for polarizer, comprising:

a) 100 parts by weight of acrylic copolymers;

b) 0.01 to 25 part by weight of chelating agent being capable of imparting an anti-static property into a pressure sensitive adhesive by forming a bond with a metal ion; and

c) 0.001 to 25 part by weight of metal salts,

wherein the chelating agent is at least one selected from the group consisting of a compound having an oxalate group, a compound having a diamine group, a compound having a polycarboxylic group and a compound having a β-ketone group.

2. The acrylic pressure sensitive adhesive composition for a polarizer or a protective film for polarizer of claim 1 , wherein the acrylic copolymers in the above a) are prepared by copolymerizing i) 90 to 99.9 wt % of (meth)acrylic acid ester monomers having alkyl group of 1 to 12 carbon atoms, and ii) 0.1 to 10 wt % of vinyl monomers and/or acrylic monomers having cross-linkable functional groups.

3. The acrylic pressure sensitive adhesive composition for a polarizer or a protective film for polarizer of claim 2 , wherein the (meth)acrylic acid ester monomers having alkyl group of 1 to 12 carbon atoms in the above i) are one or more selected from the group consisting of butyl (meth)acrylate, ethyl (meth)acrylate, methyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, n-octyl (meth)acrylate, n-tetradecyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, and 2-ethylbutyl (meth)acrylate.

4. The acrylic pressure sensitive adhesive composition for a polarizer or a protective film for polarizer of claim 2 , wherein the (meth)acrylic acid ester monomers having alkyl group of 1 to 12 carbon atoms in the i) above are mixed with one or more co-monomers selected from the group consisting of methyl acrylate, methyl methacrylate, ethyl methacrylate, vinyl acetate, styrene, and acrylonitrile.

5. The acrylic pressure sensitive adhesive composition for a polarizer or a protective film for polarizer of claim 2 , wherein the vinyl monomers and/or acrylic monomers having cross-linkable functional groups in the above ii) above are one or more selected from the group consisting of 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 2-hydroxyethyleneglycol (meth)acrylate, 2-hydroxypropyleneglycol (meth)acrylate, (meth)acrylic acid, maleic acid, fumaric acid, acrylamide, N-vinyl pyrrolidone, and N-vinyl caprolactam.

6. The acrylic pressure sensitive adhesive composition for a polarizer or a protective film for polarizer of claim 1 , wherein the compound having oxalate group is represented by the following formula (1):

wherein,

R1 and R2 are each independently hydrogen, halogen, branched or straight chain alkyl group of 1 to 20 carbon atoms, branched or straight chain alkoxy group of 1 to 20 carbon atoms, branched or straight chain alkenyl group of 2 to 20 carbon atoms, aryl group of 6 to 30 carbon atoms, arylalkyl group of 6 to 30 carbon atoms, aryloxy group of 6 to 30 carbon atoms, or cycloalkyl group of 5 to 20 carbon atoms.

7. The acrylic pressure sensitive adhesive composition for a polarizer or a protective film for polarizer of claim 1 , wherein the compound having oxalate group is one or more selected from the group consisting of diethyloxalate, dimethyloxalate, dibutyloxalate, di-tert-butyloxalate, and bis(4-methylbenzyl)oxalate.

8. The acrylic pressure sensitive adhesive composition for a polarizer or a protective film for polarizer of claim 1 , wherein the compound having diamine group is represented by the following formula (2):

wherein R3 is branched or straight chain alkylene group of 1 to 20 carbon atoms, or branched or straight chain alkenylene group of 2 to 20 carbon atoms.

9. The acrylic pressure sensitive adhesive composition for a polarizer or a protective film for polarizer of claim 1 , wherein the compound having diamine group is one or more selected from the group consisting of ethylenediamine and 1,2-diaminopropane.

10. The acrylic pressure sensitive adhesive composition for a polarizer or a protective film for polarizer of claim 1 , wherein the compound having polycarboxylic group has functional groups represented by the following formula (3a), (3b) or (3c):

11. The acrylic pressure sensitive adhesive composition for a polarizer or a protective film for polarizer of claim 1 , wherein the compound having polycarboxylic group is one or more selected from the group consisting of diethylenetriaminepentaacetic acid, ethylenediaminetetraacetic acid, and N,N-biscarboxymethylglycine.

12. The acrylic pressure sensitive adhesive composition for a polarizer or a protective film for polarizer of claim 1 , wherein the compound having β-ketone group is represented by the following formula (4):

wherein,

R7 and R8 are each independently branched or straight chain alkyl group of 1 to 20 carbon atoms, branched or straight chain alkoxy group of 1 to 20 carbon atoms, branched or straight chain alkenyl group of 2 to 20 carbon atoms, aryl group of 6 to 30 carbon atoms, arylalkyl group of 6 to 30 carbon atoms, aryloxy group of 6 to 30 carbon atoms, or cycloalkyl group of 5 to 20 carbon atoms, and

R9 is hydrogen or branched or straight chain alkyl group of 1 to 20 carbon atoms, branched or straight chain alkoxy group of 1 to 20 carbon atoms, branched or straight chain alkenyl group of 2 to 20 carbon atoms, aryl group of 6 to 30 carbon atoms, arylalkyl group of 6 to 30 carbon atoms, aryloxy group of 6 to 30 carbon atoms, or cycloalkyl group of 5 to 20 carbon atoms.

13. The acrylic pressure sensitive adhesive composition for polarizer or a protective film for polarizer of claim 1 , wherein the compound having β-ketone group is one or more selected from the group consisting of 2,4-pentadione, 1-benzoylacetone, and ethyl acetoacetate.

14. The acrylic pressure sensitive adhesive composition for a polarizer or a protective film for polarizer of claim 1 , wherein the metal salts in the c) consist of a metal cation selected from the group consisting of lithium, sodium, potassium, magnesium, calcium, barium and cesium, and an anion selected from the group consisting of Cl—, Br—, I—, BF4-, PF6-, AsF6-, C1O4-, NO2-, CO3-, N(CF3SO2)2-, N(CF3CO)2-, N(C2F5SO)2-, N(C2F5CO)2-, N(C4F9SO2)2-, C(CF3SO2)3-, and CF3SO3-.

15. The acrylic pressure sensitive adhesive composition for a polarizer or a protective film for polarizer of claim 1 , wherein the composition further comprises multifunctional crosslinking agent.

16. The acrylic pressure sensitive adhesive composition for a polarizer or a protective film for polarizer of claim 15 , wherein the multifunctional crosslinking agent is one or more selected from the group consisting of isocyanate, epoxy, aziridine and metal chelate compounds.

17. The acrylic pressure sensitive adhesive composition for a polarizer or a protective film for polarizer of claim 15 , wherein the composition comprises 0.01 to 10 part by weight of multifunctional crosslinking agent based on 100 part by weight acrylic copolymers.