Pressure-sensitive adhesive layer
The present application provides a pressure-sensitive adhesive layer comprising at least first and second regions having different physical properties, wherein the difference in physical properties, such as an elastic modulus or creep strain rate is maintained relatively large for each region, and the difference in physical properties, such as a peel force or recovery rate is maintained relatively small for each region.
1 . A pressure-sensitive adhesive layer, comprising:
a first region and
a second region,
wherein an absolute value of a difference in storage elastic moduli of the first and second regions according to Equation 5 below is 10% or more, and
wherein an absolute value of a difference in peel forces of the first and second regions according to Equation 8 below is 40% or less, and
wherein the pressure-sensitive adhesive layer comprises a crystalline acrylic copolymer having a melting point of −20° C. or less:
D M60 =100×( M 60.1 −M 60.2 )/ M 60.2 [Equation 5]
D PG =100×( P G,1 −P G,2 )/ P G,2 [Equation 8]
wherein, D M60 is the difference in the storage elastic moduli, M 60.1 is a storage elastic modulus of the first region at 60° C., and M 60.2 is a storage elastic modulus of the second region at 60° C.; and D PG is the difference in the peel force, P G,1 is a peel force of the first region to a glass, and P G,2 is a peel force of the second region to the glass.
2 . The pressure-sensitive adhesive layer according to claim 1 , wherein the storage elastic modulus of the second region at 60° C. is 50,000 Pa or less.
3 . The pressure-sensitive adhesive layer according to claim 1 , wherein an absolute value of a difference in storage elastic moduli of the first and second regions according to Equation 6 below is 3% or more:
D M30 =100×( M 30.1 −M 30.2 )/ M 30.2 [Equation 6]
wherein, D M30 is the difference in the storage elastic moduli, M 30.1 is a storage elastic modulus of the first region at 30° C., and M 30.2 is a storage elastic modulus of the second region at 30° C.
4 . The pressure-sensitive adhesive layer according to claim 3 , wherein the storage elastic modulus of the second region at 30° C. is 50,000 Pa or less.
5 . The pressure-sensitive adhesive layer according to claim 1 , wherein an absolute value of a difference in storage elastic moduli of the first and second regions according to Equation 7 below is 1% or more:
D M20 =100×( M 20.1 −M 20.2 )/ M 20.2 [Equation 7]
wherein, D M20 is the difference in the storage elastic moduli, M 20.1 is a storage elastic modulus of the first region at −20° C., and M 20.2 is a storage elastic modulus of the second region at −20° C.
6 . The pressure-sensitive adhesive layer according to claim 5 , wherein the storage elastic modulus of the second region at −20° C. is 500,000 Pa or less.
7 . The pressure-sensitive adhesive layer according to claim 1 , wherein the peel force of the first region to a glass is at least 500 gf/inch.
8 . The pressure-sensitive adhesive layer according to claim 1 , wherein an absolute value of a difference in peel force of the first and second regions according to Equation 9 below is 50% or less:
D PI =100×( P I,1 −P I,2 )/ P I,2 [Equation 9]
wherein, D PI is the difference in the peel force, P I,1 is a peel force of the first region to a polyimide film, and P I,2 is the peel force of the second region to a polyimide film.
9 . The pressure-sensitive adhesive layer according to claim 8 , wherein the peel force of the first region to a polyimide film is at least 500 gf/inch.
10 . A pressure-sensitive adhesive film, comprising:
a base film; and
the pressure-sensitive adhesive layer of claim 1 formed on one side or both sides of the base film.
11 . An optical laminate, comprising:
an optical film; and
the pressure-sensitive adhesive layer of claim 1 formed on one side or both sides of the optical film.