Adhesive composition for touch screen panel, optical adhesive film and touch screen panel

1. An adhesive composition comprising:

a (meth)acrylic acid ester-based photo-curable resin; and

an oxygen-free di-functional diene-based rubber hardener.

2. The adhesive composition of claim 1 , wherein the oxygen-free di-functional diene-based rubber hardener comprises a diene-based di-functional group at both ends thereof.

3. The adhesive composition of claim 1 , wherein the oxygen-free di-functional diene-based rubber hardener comprises one selected from the group consisting of a di-functional polybutadiene, a di-functional isoprene rubber, a di-functional isobutylene-isoprene rubber, a di-functional styrene-butylene rubber, and a combination thereof.

4. The adhesive composition of claim 1 , wherein the oxygen-free di-functional diene-based rubber hardener has a weight average molecular weight from 3,000 to 20,000.

5. The adhesive composition of claim 1 , wherein the oxygen-free di-functional diene-based rubber hardener has a dielectric constant k value from 2.1 to 2.5 measured at a frequency of 100 kHz.

6. The adhesive composition of claim 1 , wherein the adhesive composition comprises:

100 parts by weight of the (meth)acrylic acid ester-based photo-curable resin; and

0.1 to 2 parts by weight of the oxygen-free di-functional diene-based rubber hardener.

7. The adhesive composition of claim 1 , wherein the (meth)acrylic acid ester-based photo-curable resin is a resin in which a (meth)acrylic acid ester monomer and a crosslinkable monomer comprising at least one selected from the group consisting of a hydroxy group-containing monomer, a carboxyl group-containing monomer, or a nitrogen-containing monomer, and a combination thereof are copolymerized with each other.

8. The adhesive composition of claim 7 , wherein the (meth)acrylic acid ester monomer is alkyl (meth)acrylate, and an alkyl of the alkyl (meth)acrylate is a linear or branched C1 to C14 alkyl.

9. The adhesive composition of claim 7 , wherein the (meth)acrylic acid ester monomer comprises one selected from the group consisting of methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, sec-butyl (meth)acrylate, pentyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-ethylbutyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, isobornyl (meth)acrylate, isononyl (meth)acrylate, and a combination thereof.

10. The adhesive composition of claim 7 , wherein the crosslinkable monomer comprises one selected from the group consisting of 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 2-hydroxyethylene glycol (meth)acrylate, 2-hydroxypropylene glycol (meth)acrylate, acrylic acid, methacrylic acid, 2-(meth)acryloyloxy acetic acid, 3-(meth)acryloyloxy propyl acid, 4-(meth)acryloyloxy butyric acid, acrylic acid dimer, itaconic acid, maleic acid, 2-isocyanatoethyl (meth)acrylate, 3-isocyanatopropyl (meth)acrylate, 4-isocyanatobutyl (meth)acrylate, (meth)acrylamide, N-vinyl pyrrolidone, N-vinyl caprolactam, and a combination thereof.

11. The adhesive composition of claim 1 , further comprising:

a photoinitiator.

12. The adhesive composition of claim 11 , wherein the photoinitiator comprises one selected from the group consisting of a benzoin-based initiator, a hydroxy ketone-based initiator, an amino ketone-based initiator, caprolactam, and a combination thereof.

13. An optical adhesive film comprising:

an adhesive layer which comprises photo-cured products of the adhesive composition according to claim 1 .

14. A touch screen panel comprising:

a conductive plastic film layer having a conductive layer formed on one surface thereof;

the optical adhesive film according to claim 13 laminated on an upper portion of the conductive layer; and

a cover window layer laminated on an upper portion of the optical adhesive film.

15. The touch screen panel of claim 14 , wherein the conductive plastic film layer is a polyethylene terephthalate film having a conductive metal oxide layer formed on one surface thereof.

16. The touch screen panel of claim 14 , wherein the cover window layer is a transparent plastic film replacing glass or tempered glass.