Hard coating film, hard coating agent, and polarizing plate including the hard coating film
A hard coating film that is curled to a height of less than 20 mm and has a pencil hardness of 3H or harder, the hard coating film including a hard coating agent that includes a hyperbranched (meth)acrylate oligomer having about 50 to about 200 (meth)acrylate groups, reactive nanoparticles, and a polyfunctional monomer.
1. A hard coating film that is curled to a height of less than 20 mm and has a pencil hardness of 3H or harder, the hard coating film comprising a hard coating agent including:
a hyperbranched (meth)acrylate oligomer having about 50 to about 200 (meth)acrylate groups,
reactive nanoparticles, the reactive nanoparticles being inorganic nanoparticles surface modified with a (meth)acrylate compound, about 3 to about 50% of a surface area of the inorganic nanoparticles being modified with the (meth)acrylate compound, and
a polyfunctional monomer.
2. The hard coating film as claimed in claim 1 , wherein the hyperbranched (meth)acrylate oligomer is represented by Formula 1:
[Formula 1]
X—(A) n
wherein, in Formula 1, X is represented by Formula 1-1 below, A is (meth)acrylate, and n is about 50 to about 200,
wherein, in Formula 1-1:
the core is a C 3 -C 50 aliphatic or aromatic hydrocarbon having functional groups bonded to R1 or a C 3 -C 50 aliphatic or aromatic hydrocarbon having functional groups bonded to R1 and containing at least one heteroatom,
R1 and R2 are each independently a C 1 -C 50 aliphatic or aromatic hydrocarbon or a C 1 -C 50 aliphatic or aromatic hydrocarbon containing at least one heteroatom, and
E is an ester bond.
3. The hard coating film as claimed in claim 1 , wherein the reactive nanoparticles have an average diameter of about 10 nm to about 100 nm.
4. The hard coating film as claimed in claim 1 , wherein the inorganic nanoparticles are selected from the group of nanoparticles of SiO 2 , Al 2 O 3 , CaCO 3 , TiO 2 , and mixtures thereof.
5. The hard coating film as claimed in claim 1 , wherein the polyfunctional monomer is selected from the group of a polyfunctional (meth)acrylate compound which may optionally further comprise hydroxyl group; a fluorinated polyfunctional (meth)acrylate compound; and mixtures thereof.
6. The hard coating film as claimed in claim 5 , wherein the polyfunctional monomer includes the polyfunctional (meth)acrylate compound which may optionally further comprise hydroxyl group, the polyfunctional (meth)acrylate compound including at least one of dipentaerythritol hexa(meth)acrylate, pentaerythritol tri(meth)acrylate, tri(2-hydroxyethyl)isocyanurate tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, hexanediol di(meth)acrylate, pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, and dicyclodecane dimethanol di(meth)acrylate.
7. The hard coating film as claimed in claim 5 , wherein the polyfunctional monomer includes the fluorinated polyfunctional (meth)acrylate compound, the fluorinated polyfunctional (meth)acrylate compound being prepared by a reaction of a perfluoropolyether-containing compound and a polyfunctional (meth)acrylate compound.
8. The hard coating film as claimed in claim 1 , wherein the hard coating agent includes:
about 15 to about 60% by weight of the hyperbranched (meth)acrylate oligomer,
about 5 to about 60% by weight of the reactive nanoparticles, and
about 1 to about 40% by weight of the polyfunctional monomer.
9. The hard coating film as claimed in claim 8 , wherein the hard coating agent includes:
15 to 40% by weight of the hyperbranched (meth)acrylate oligomer,
5 to 60% by weight of the reactive nanoparticles, and
1 to 25% by weight of the polyfunctional monomer.
10. The hard coating film as claimed in claim 1 , further comprising a reactive fluorinated compound.
11. The hard coating film as claimed in claim 10 , wherein the reactive fluorinated compound is represented by Formula 3:
(CH 2 ═CR1COO) 2 Rf (3),
wherein R1 is a hydrogen atom or a C 1 -C 3 alkyl group and Rf is a perfluoroalkylene group represented by one of the following group (a) to group (e) of Formula (4):
wherein:
each R f1 is a C 1 -C 10 straight or branched perfluoroalkylene group, and
R f2 , R f3 , R f4 , and R f5 are each independently a C 1 -C 14 straight or branched perfluoroalkyl group.
12. The hard coating film as claimed in claim 10 , wherein the reactive fluorinated compound is present in an amount of about 0.01 to about 5 parts by weight, based on 100 parts by weight of the hard coating agent.
13. The hard coating film as claimed in claim 1 , wherein the hard coating agent further includes one or more additives selected from the group of photopolymerization initiators, solvents, photosensitizers, polymerization inhibitors, leveling agents, wettability improvers, surfactants, plasticizers, UV absorbers, antioxidants, antistatic agents, silane coupling agents, inorganic fillers, and defoaming agents.
14. The hard coating film as claimed in claim 1 , wherein the hard coating film is curled to a height of less than about 20 mm at a thickness of about 2 to about 30 μm.
15. A polarizing plate comprising the hard coating film as claimed in claim 1 .
16. A hard coating agent, comprising:
a hyperbranched (meth)acrylate oligomer;
reactive nanoparticles, the reactive nanoparticles being inorganic nanoparticles surface modified with a (meth)acrylate compound, about 3 to about 50% of a surface area of the inorganic nanoparticles being modified with the (meth)acrylate compound; and
a polyfunctional monomer,
wherein a number of (meth)acrylate groups in the hyperbranched (meth)acrylate oligomer is about 50 to about 200.
17. The hard coating agent as claimed in claim 16 , wherein the hyperbranched (meth)acrylate oligomer is represented by Formula 1:
[Formula 1]
X—(A) n
wherein, in Formula 1, X is represented by Formula 1-1 below, A is (meth)acrylate, and n is about 50 to about 200,
wherein, in Formula 1-1:
the core is a C 3 -C 50 aliphatic or aromatic hydrocarbon having functional groups bonded to R1 or a C 3 -C 50 aliphatic or aromatic hydrocarbon having functional groups bonded to R1 and containing at least one heteroatom,
R1 and R2 are each independently a C 1 -C 50 aliphatic or aromatic hydrocarbon or a C 1 -C 50 aliphatic or aromatic hydrocarbon containing at least one heteroatom, and
E is an ester bond.
18. The hard coating agent as claimed in claim 16 , further comprising a reactive fluorinated compound.
19. The hard coating agent as claimed in claim 18 , wherein the reactive fluorinated compound is represented by Formula 3:
(CH 2 ═CR1COO) 2 Rf (3),
wherein R1 is a hydrogen atom or a C 1 -C 3 alkyl group and Rf is a perfluoroalkylene group having a structure one of the following group (a) to group (e) of Formula (4):
wherein:
each R f1 is a C 1 -C 10 straight or branched perfluoroalkylene group, and
R f2 , R f3 , R f4 , and R f5 are each independently a C 1 -C 14 straight or branched perfluoroalkyl group.
20. The hard coating agent as claimed in claim 16 , wherein the hard coating agent includes:
15 to 40% by weight of the hyperbranched (meth)acrylate oligomer,
5 to 60% by weight of the reactive nanoparticles, and
1 to 25% by weight of the polyfunctional monomer.