Polarizer protective film, polarizing plate comprising same, and liquid crystal display device comprising polarizing plate
The present specification relates to a polarizer protective film including a photocurable resin including a multifunctional acrylate-based monomer and an acrylate-based oligomer having an elongation of 5% to 200%; and a dye or a pigment having a maximum absorption wavelength of 580 nm to 610 nm, and a polarizing plate and a liquid crystal display device including the same.
1. A polarizer protective film comprising:
a photocurable resin including a multifunctional acrylate-based monomer and an acrylate-based oligomer having an elongation of 5% to 200%; and
a total amount of 0.1 to 1 part by weight of a sole dye or pigment based on 100 parts by weight of the photocurable resin, wherein the sole dye or pigment consists of:
a) a dye or pigment having a maximum absorption wavelength in a range of 580 nm to 610 nm, or
b) a combination of a) and a dye or pigment having a maximum absorption wavelength in a range of 480 nm to 510 nm;
wherein the polarizer protective film has an average light transmittance of 50% or greater in a 400 nm to 550 nm wavelength region, and a pencil hardness of H or greater under a 500 g load.
2. The polarizer protective film of claim 1 , further comprising an adhesive layer provided on one surface of the polarizer protective film.
3. The polarizer protective film of claim 1 , wherein the dye or the pigment is a porphyrin derivative compound, a cyanine derivative compound or a squarylium derivative compound.
4. The polarizer protective film of claim 1 , wherein the photocurable resin includes one or more types selected from the group consisting of a multifunctional acrylate-based oligomer and a multifunctional acrylate-based elastic polymer.
5. The polarizer protective film of claim 1 , wherein the multifunctional acrylate-based monomer includes one or more of hexanediol diacrylate (HDDA), tripropylene glycol diacrylate (TPGDA), ethylene glycol diacrylate (EGDA), trimethylolpropane triacrylate (TMPTA), trimethylolpropane ethoxy triacrylate (TMPEOTA), glycerin propoxylated triacrylate (GPTA), pentaerythritol tetraacrylate (PETA) and dipentaerythritol hexaacrylate (DPHA).
6. The polarizer protective film of claim 1 , wherein the acrylate-based oligomer is an acrylate-based oligomer modified with one or more types of ethylene oxide, propylene oxide or caprolactone.
7. The polarizer protective film of claim 1 , wherein, in the photocurable resin, the multifunctional acrylate-based monomer and the acrylate-based oligomer having an elongation of 5% to 200% are cured in a weight ratio of 2:8 to 8:2.
8. The polarizer protective film of claim 1 , further comprising a photopolymerization initiator.
9. The polarizer protective film of claim 1 , which has an average light transmittance of 30% or less in a 580 nm to 610 nm wavelength region.
10. The polarizer protective film of claim 5 , which has an average light transmittance of less than 70% in a 480 nm to 510 nm wavelength region.
11. The polarizer protective film of claim 1 , which has a maximum absorption wavelength in a 590 nm to 600 nm range.
12. The polarizer protective film of claim 1 , further comprising a surface layer provided on one surface of the polarizer protective film.
13. The polarizer protective film of claim 12 , wherein a thickness of the surface layer is 0.01 to 1 with respect to a thickness of the polarizer protective film.
14. A polarizing plate comprising:
a polarizer; and
the polarizer protective film of claim 1 provided on at least one surface of the polarizer as a protective film.
15. A liquid crystal display device comprising:
a backlight unit;
a liquid crystal panel provided on one side of the backlight unit, the liquid crystal panel comprising a color filter; and
the polarizing plate of claim 14 provided between the backlight unit and the liquid crystal panel.
16. The polarizer protective film of claim 1 , wherein the dye or pigment having a maximum absorption wavelength in a range of 580 nm to 610 nm is present in an amount of 0.1 to 0.5 part by weight based on 100 parts by weight of the photocurable resin.
17. The polarizer protective film of claim 1 , wherein the sole dye or pigment consists of:
the dye or pigment having a maximum absorption wavelength in a range of 580 nm to 610 nm in an amount of 0.1 to 0.5 part by weight based on 100 parts by weight of the photocurable resin; and
the dye or pigment having a maximum absorption wavelength in a range of 480 nm to 510 nm in an amount of 0.01 to 0.5 part by weight based on 100 parts by weight of the photocurable resin.
18. A method for preparing the polarizer protective film of claim 1 , the method comprising:
coating on a releasing film a composition including the photocurable resin including the multifunctional acrylate-based monomer, the acrylate-based oligomer having an elongation of 5% to 200%, and the total amount of 0.1 to 1 part by weight of the sole dye or pigment based on 100 parts by weight of the photocurable resin, wherein the sole dye or pigment consists of:
a) the dye or pigment having a maximum absorption wavelength of 580 nm to 610 nm, or
b) the combination of a) and the dye or pigment having a maximum absorption wavelength in a range of 480 nm to 510 nm;
forming the polarizer protective film by curing the composition; and
peeling off the releasing film from the polarizer protective film,
the polarizer protective film having an average light transmittance of 50% or greater in a 400 nm to 550 nm wavelength region, and a pencil hardness of H or greater under a 500 g load.
19. The method for preparing the polarizer protective film of claim 18 , wherein the composition has changes in the transmittance, which is measured by the following Equation 1, that is less than 5%:
changes
in
transmittance
=
(
average
light
transmittance
in
650
nm
to
710
nm
region
wavelength
before
UV
curing
-
average
light
transmittance
in
650
nm
to
710
nm
region
wavelength
after
UV
curing
)
average
light
transmittance
in
650
nm
to
710
nm
region
wavelength
before
UV
curing
×
100
[
Equation
1
]
wherein in Equation 1, the ultraviolet (UV) curing means coating the composition including the sole dye or pigment on a transparent substrate, and curing the result by exposure to ultraviolet rays having a 290 nm to 320 nm wavelength with an irradiation amount of 20 mJ/cm 2 to 600 mJ/cm 2 .