Adhesive film, adhesive composition for the same, and display apparatus including the same
An adhesive film including a compound including a urethane functional group, the adhesive film having a ratio (B/A) of 180° peel strength (B) after leaving the adhesive film at 70° C. for 2 minutes to 180° peel strength (A) at 25° C. of about 5 or more, is disclosed. A display apparatus including the adhesive film is also disclosed.
1. An adhesive film comprising a urethane functional group, the adhesive film having a ratio (B/A) of 180° peel strength (B) after leaving the adhesive film at 70° C. for 2 minutes to 180° peel strength (A) at 25° C. of about 5 or more,
wherein the adhesive film comprises a cured product of an adhesive composition comprising a urethane (meth)acrylate and a (meth)acrylic copolymer,
wherein the urethane (meth)acrylate has a glass transition temperature of about −5° C. to 5° C.,
wherein the urethane (meth)acrylate is present in the adhesive composition in an amount of about 1 wt % to about 9 wt % based on the total weight of solids in the composition,
wherein the (meth)acrylic copolymer comprises a copolymer of about 50 wt % to about 70 wt % of an alkyl group-containing alkyl (meth)acrylate, about 15 wt % to about 25 wt % of an alicyclic group-containing (meth)acrylate, and about 5 wt % to about 35 wt % of the hydroxyl group-containing (meth)acrylate, based on the total weight of solids, and
wherein the peel strength (A) is about 300 g/inch or less and the peel strength (B) is about 1000 g/inch or more, the alkyl group-containing alkyl (meth)acrylate comprises one or more of methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, ethylhexyl (meth)acrylate, heptyl (meth)acrylate and octyl (meth)acrylate.
2. The adhesive film according to claim 1 , wherein the adhesive film has a shear strength at 25° C. of about 15 kgf or more.
3. The adhesive film according to claim 1 , wherein the adhesive composition further comprises an initiator, a crosslinking agent, a silane coupling agent, or a mixture thereof.
4. The adhesive film according to claim 3 , wherein the adhesive composition comprises, in terms of solid content,
about 100 parts by weight of the (meth)acrylic copolymer;
about 1 part by weight to about 9 parts by weight of the urethane (meth)acrylate;
about 0.001 parts by weight to about 5 parts by weight of the initiator;
about 0.01 parts by weight to about 5 parts by weight of the crosslinking agent; and
about 0.01 parts by weight to about 0.1 parts by weight of the silane coupling agent.
5. The adhesive film according to claim 1 , wherein the adhesive film has a thickness of about 10 μm to about 2 mm.
6. A display member comprising:
an optical film; and
an adhesive film according to claim 1 attached to one or two surfaces of the optical film.
7. The display member according to claim 6 , wherein the optical film comprises a touch panel, a window, a polarizing plate, a color filter, a retardation film, an elliptical polarizing film, a reflective film, an anti-reflective film, a compensation film, a brightness enhancing film, an alignment film, a light diffusion film, a glass anti-scattering film, a surface protective film, a plastic LCD substrate, an indium tin oxide (ITO) containing film, a fluorinated tin oxide (FTO) containing film, an aluminum-doped zinc oxide (AZO) containing film, a carbon-nanotube (CNT) containing film, an Ag-nanowire containing film, or graphene.