ADHESIVE COMPOSITION, ADHESIVE FILM FORMED FROM SAME, AND DISPLAY MEMBER COMPRISING SAME
Disclosed herein is an adhesive film which includes: a monomer mixture including a hydroxyl group-containing (meth)acrylate and a comonomer; and nanoparticles, wherein the nanoparticles include a silicone polymer and have an average particle diameter of about 5 nm to about 800 nm.
1 . An adhesive composition comprising:
a monomer mixture comprising a hydroxyl group-containing (meth)acrylate and a comonomer; and
nanoparticles,
wherein the nanoparticles comprise a silicone polymer and have an average particle diameter of about 5 nm to about 800 nm.
2 . The adhesive composition according to claim 1 , wherein the hydroxyl group-containing (meth)acrylate has a glass transition temperature (Tg) of about −80° C. to about −20° C.
3 . The adhesive composition according to claim 1 , wherein the comonomer comprises at least one of alkyl (meth)acrylate monomers, ethylene oxide-containing monomers, propylene oxide-containing monomers, amine group-containing monomers, amide group-containing monomers, alkoxy group-containing monomers, phosphoric acid group-containing monomers, sulfonic acid group-containing monomers, phenyl group-containing monomers, and silane group-containing monomers, and has a glass transition temperature (Tg) of about −150° C. to about 0° C.
4 . The adhesive composition according to claim 1 , wherein the nanoparticles have a core-shell structure in which the core and the shell have a glass transition temperature satisfying Equation 1:
Tg(c)<Tg(s) [Equation 1]
(where Tg (c) is a glass transition temperature (° C.) of the core and Tg (s) is a glass transition temperature (° C.) of the shell).
5 . The adhesive composition according to claim 4 , wherein the core has a glass transition temperature of about −200° C. to about −40° C. and the shell has a glass transition temperature of about 15° C. to about 200° C.
6 . The adhesive composition according to claim 4 , wherein the core comprises a polysiloxane and the shell comprises a poly(meth)acrylate.
7 . The adhesive composition according to claim 1 , wherein the nanoparticles are present in an amount of about 0.1 parts by weight to about 20 parts by weight based on 100 parts by weight of the monomer mixture.
8 . The adhesive composition according to claim 1 , further comprising: at least one of an initiator and a crosslinking agent.
9 . An adhesive film formed of the adhesive composition according to claim 1 .
10 . The adhesive film according to claim 9 , comprising: a hydroxyl group-containing (meth)acrylic copolymer polymerized from a monomer mixture comprising a hydroxyl group-containing (meth)acrylate and a comonomer.
11 . The adhesive film according to claim 10 , wherein the hydroxyl group-containing (meth)acrylic copolymer is polymerized from the monomer mixture comprising about 15 wt % to about 45 wt % of the hydroxyl group-containing (meth)acrylate and about 55 wt % to about 85 wt % of the comonomer.
12 . The adhesive film according to claim 10 , further comprising: nanoparticles,
wherein a difference in index of refraction between the nanoparticles and the hydroxyl group-containing (meth)acrylic copolymer is about 0.05 or less.
13 . The adhesive film according to claim 9 , wherein the adhesive film has a glass transition temperature (Tg) of about 0° C. or less.
14 . The adhesive film according to claim 9 , wherein the adhesive film has a storage modulus at 80° C. of about 10 kPa to about 1,000 kPa.
15 . The adhesive film according to claim 9 , wherein the adhesive film has a storage modulus at 25° C. of about 10 kPa to about 1,000 kPa.
16 . The adhesive film according to claim 9 , wherein the adhesive film has a storage modulus at −20° C. of about 10 kPa to about 1,000 kPa.
17 . The adhesive film according to claim 9 , wherein a ratio of storage modulus at 80° C. to storage modulus at −20° C. of the adhesive film ranges from about 1:1 to about 1:20.
18 . The adhesive film according to claim 9 , wherein the adhesive film having a thickness of 100 μm has a haze of about 4% or less.
19 . The adhesive film according to claim 9 , wherein the adhesive film having a thickness of 100 μm has a haze of about 5% or less, as measured after the adhesive film is subjected to 200% stretching.
20 . The adhesive film according to claim 9 , wherein the adhesive film having a thickness of 100 μm has a recovery rate of about 30% to about 98%, as calculated by Equation 2:
Recovery rate (%)=(1−( Xf/X 0))×100, [Equation 2]
(where X0 and Xf are defined as follows: When both ends of each of polyethylene terephthalate (PET) films (thickness: about 75 μm) having a size of about 50 mm×about 20 mm (length×width) are defined as a first end and a second end, respectively, a specimen is prepared by bonding ends of two PET films to each other via an adhesive film having a size of about 20 mm×about 20 mm (length×width) in order of first end of first PET film/adhesive film (length×width: about 20 mm×about 20 mm)/second end of second PET film. Next, jigs are secured to non-bonded ends of the PET films of the specimen, respectively. Next, the jig at one side is kept fixed and the jig at the other side is pulled to a length of about 1,000% of thickness (unit: μm) of the adhesive film (to a length of about 10 times an initial thickness (X0) of the adhesive film) at a rate of about 300 mm/min and then maintained for about 10 seconds. When a force of about 0 kPa is applied to the adhesive film by recovering the adhesive film at the same rate (about 300 mm/min) as the pulling rate, an increased length of the adhesive film is defined as Xf (unit: μm)).
21 . The adhesive film according to claim 9 , wherein the adhesive film has a bubble generation area of about 0%, as measured after the adhesive film (length×width×thickness: about 13 cm×about 3 cm×about 100 μm) comprising a about 50 μm thick PET film stacked on one surface thereof and an about 100 μm thick PET film stacked on the other surface thereof is bent towards the about 50 μm thick PET film such that the length of the adhesive film is halved, followed by placing the adhesive film between parallel frames having a gap of about 1 cm, and then subjected to aging under conditions of about 70° C. and about 93% RH for about 24 hours.
22 . The adhesive film according to claim 9 , wherein the adhesive film has a T-peel strength of about 400 gf/in to about 4,000 gf/in, as measured at 25° C. with respect to a corona-treated polyethylene terephthalate (PET) film.
23 . The adhesive film according to claim 9 , wherein the adhesive film has a T-peel strength of about 200 gf/in to about 3,000 gf/in, as measured at 60° C. with respect to a corona-treated polyethylene terephthalate (PET) film.
24 . A display member comprising:
an optical film; and
the adhesive film according to claim 9 , the adhesive film being attached to one or both surfaces of the optical film.
25 . The display member according to claim 24 , wherein the optical film comprises touch panels, windows, polarizing plates, color filters, retardation films, elliptical polarizing films, reflective polarizing films, anti-reflective films, compensation films, brightness improving films, alignment films, optical diffusion films, glass shatter-proof films, surface protective films, OLED device barrier layers, plastic LCD substrates, indium tin oxide (ITO), fluorinated tin oxide (FTO), aluminum-doped zinc oxide (AZO), carbon nanotube (CNT)-containing films, Ag nanowire-containing films, and graphene-containing films.