Adhesive composition and use thereof
A pressure-sensitive adhesive composition and a use thereof are provided. The present application can provide a pressure-sensitive adhesive composition which has excellent performance to block ultraviolet rays including a blue region of 380 nm or more and exhibits excellent durability upon reliability evaluation without deteriorating the optical characteristics of a polarizing plate when applied to the polarizing plate. The pressure-sensitive adhesive composition of the present application can be used, for example, for a polarizing plate and an organic light emitting device.
1. A pressure-sensitive adhesive composition comprising an acrylic polymer and an ultraviolet absorber, wherein the ultraviolet absorber comprises a pyrazoline-based ultraviolet absorber and a malonic acid-based ultraviolet absorber,
wherein the pyrazoline-based ultraviolet absorber is a compound represented by the following formula 1:
wherein, L 1 , L 2 and L 3 are each independently a single bond, an alkylene group, an alkenylene group, an alkynylene group, —COO— or —OCO—, and R 1 , R 2 and R 3 are each independently hydrogen, halogen, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an alkoxycarbonyl group, a cyano group or a nitro group,
wherein the malonic acid-based ultraviolet absorber is a compound represented by the following formula 2:
wherein, L 4 is a single bond, an alkylene group, an alkenylene group, an alkynylene group, —COO— or —OCO—, and R 4 , R 5 , R 6 and R 7 are each independently hydrogen, halogen, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an alkoxycarbonyl group, a cyano group or a nitro group,
wherein the ultraviolet absorber is included in an amount of 0.01 to 10 parts by weight relative to 100 parts by weight of the acrylic polymer, wherein the pyrazoline-based ultraviolet absorber is included in an amount of 0.01 to 5 parts by weight and the malonic acid-based ultraviolet absorber is included in an amount of 1 to 10 parts by weight, relative to 100 parts by weight of the acrylic polymer.
2. The pressure-sensitive adhesive composition according to claim 1 , wherein the acrylic polymer comprises a polymerization unit of a (meth)acrylic acid ester monomer.
3. The pressure-sensitive adhesive composition according to claim 2 , wherein the acrylic polymer further comprises a polymerization unit of a copolymerizable monomer having a polar group.
4. The pressure-sensitive adhesive composition according to claim 1 , wherein the maximum absorption wavelength of the pyrazoline-based ultraviolet absorber is in a range of 380 nm to 390 nm.
5. The pressure-sensitive adhesive composition according to claim 1 , wherein the maximum absorption wavelength of the malonic acid-based ultraviolet absorber is in a range of 380 nm to 390 nm.
6. The pressure-sensitive adhesive composition according to claim 1 , comprising a multifunctional crosslinking agent.
7. A polarizing plate comprising a polarizer and a pressure-sensitive adhesive layer, wherein the pressure-sensitive adhesive layer comprises a cured product of the pressure-sensitive adhesive composition of claim 1 .
8. The polarizing plate according to claim 7 , wherein the pressure-sensitive adhesive layer has a thickness of 1 μm to 30 μm.
9. The polarizing plate according to claim 7 , wherein the polarizing plate has transmittance of 0.6% or less for light having a wavelength of 380 nm or more to 400 nm or less, and transmittance of 5% or less for light having a wavelength of more than 400 nm to 410 nm or less.
10. The polarizing plate according to claim 7 , wherein the polarizing plate has a b value of 9.5 or less in ab color coordinates.
11. The polarizing plate according to claim 7 , wherein the polarizing plate does not cause lifting at the pressure-sensitive adhesive layer interface upon reliability evaluation that the polarizing plate is stored at a temperature of 60 .degree. C. and 90% relative humidity for 1000 hours.
12. The polarizing plate according to claim 7 , further comprising a retardation layer having a quarter-wavelength phase retardation characteristic.
13. The polarizing plate according to claim 12 , wherein the pressure-sensitive adhesive layer is present between the polarizer and the retardation layer.
14. The polarizing plate according to claim 12 , further comprising an upper layer existing on an opposite side of the polarizer facing the retardation layer, a lower layer on an opposite side of the retardation layer facing the polarizer, an intermediate layer between the polarizer and the retardation layer, or a combination thereof, and the pressure-sensitive adhesive layer between the polarizer and the upper layer, between the polarizer and the intermediate layer, between the retardation layer and the intermediate layer or between the retardation layer and the lower layer.
15. An organic light emitting device comprising an organic light emitting panel and the polarizing plate of claim 7 .
16. The organic light emitting device according to claim 15 , wherein the organic light emitting panel comprises a plastic substrate, and a first electrode layer, an organic light emitting layer and a second electrode layer, which are sequentially provided on a first surface of the plastic substrate, and the polarizing plate is provided on a second surface of the plastic substrate.