Optical film, display device, and composition for forming colored layer
An optical film comprises: a transparent substrate having an ultraviolet blocking rate of 85% or more according to JIS L 1925; one or more functional layers formed on a first surface side of the transparent substrate; and a colored layer that is formed on a second surface side of the transparent substrate that is configured by one or more layers containing a colored material. The colored layer contains a first colorant that has a maximum absorption wavelength in a range of 470 nm or more and 530 nm or less, an absorption spectrum thereof having a half-width of 15 nm or more and 45 nm or less, and a second colorant that has a maximum absorption wavelength in a range of 560 nm or more and 620 nm or less, an absorption spectrum thereof having a half-width of 15 nm or more and 55 nm or less.
1 . An optical film, comprising:
a transparent substrate having an ultra violet blocking rate of 85% or more, wherein the ultraviolet blocking rate ultraviolet blocking rate is calculated by subtracting an average transmittance in a wavelength range from 290 nm to 400 nm of the transparent substrate expressed in percent (%) from 100%;
one or more functional layers formed on a first surface side of the transparent substrate; and
a colored layer that is formed on a second surface side of the transparent substrate that is configured by one or more layers containing a colored material;
wherein the colored layer contains
a first colorant that has a maximum absorption wavelength in a range of 470 nm or more and 530 nm or less, an absorption spectrum thereof having a halfwidth of 15 nm or more and 45 nm or less, and
a second colorant that has a maximum absorption wavelength in a range of 560 nm or more and 620 nm or less, an absorption spectrum thereof having a half-width of 15 nm or more and 55 nm or less,
at least one of the functional layer and the colored layer contains a black organic pigment, and
hue values a* and b* defined by equations (1) to (9) below are each in a range of −5 or more and +5 or less
[
Math
.
1
]
a
*
=
500
{
f
(
X
X
n
)
-
f
(
Y
Y
n
)
}
(
1
)
[
Math
.
2
]
b
*
=
200
{
f
(
Y
Y
n
)
-
f
(
Z
Z
n
)
}
(
2
)
[
Math
.
3
]
f
(
t
)
=
{
t
1
3
,
[
t
>
(
6
29
)
3
]
1
3
(
29
6
)
2
t
+
4
29
,
[
t
≤
(
6
29
)
3
]
(
3
)
[
Math
.
4
]
R
1
(
λ
)
[
%
]
=
(
100
-
R
2
(
λ
)
)
100
×
T
(
λ
)
100
×
T
(
λ
)
100
×
R
E
(
λ
)
(
4
)
[
Math
.
5
]
R
(
λ
)
[
%
]
=
R
1
(
λ
)
+
R
2
(
λ
)
(
5
)
[
Math
.
6
]
X
=
k
×
∫
380
780
P
D
65
(
λ
)
×
R
(
λ
)
×
x
_
(
λ
)
d
λ
(
6
)
[
Math
.
7
]
Y
=
k
×
∫
380
780
P
D
65
(
λ
)
×
R
(
λ
)
×
y
_
(
λ
)
d
λ
(
7
)
[
Math
.
8
]
Z
=
k
×
∫
380
780
P
D
65
(
λ
)
×
R
(
λ
)
×
z
_
(
λ
)
d
λ
(
8
)
[
Math
.
9
]
k
=
100
/
∫
380
780
P
D
65
(
λ
)
×
R
(
λ
)
×
y
_
(
λ
)
d
λ
(
9
)
wherein λ is a variable representing a wavelength, and t is a variable representing a ratio of X, Y, and Z with respect to Xn, Yn, and Zn, a* and b* calculated from equations (1) to (3) are calculated according to a calculation method in a CIE 1976 L*, a*, b* color space (CIELAB color space), In equations (1) and (2), Xn, Yn, and Zn are tristimulus values at a white point of a D65 light source, in equation (4), RE(λ) is a function representing a reflectance [%] at a completely diffuse reflection surface (100% at every wavelength), R2(λ) is a function representing a surface reflectance [%] at an outermost surface of the optical film on an opposite side to the colored layer, and T(λ) is a function representing a transmittance of the optical film, in equations (6) to (9), PD65(λ) is a D65 light source spectrum, x-bar(λ), y-bar(λ), and z-bar(λ) are CIE1931 color matching functions at 2° field of view, a definite integral in equations (6) to (9) can be calculated by an appropriate numerical integration, a wavelength interval when performing a numerical integration is, a 1 nm interval.
2 . The optical film of claim 1 , wherein
a pencil hardness of a surface on the functional layer side under a 500 g load is H or higher.
3 . The optical film of claim 1 , wherein
the colored layer contains at least one of a radical scavenger, a peroxide decomposer, and a singlet oxygen quencher.
4 . The optical film of claim 3 , wherein
the colored layer contains, as the radical scavenger, a hindered amine-based light stabilizer having a molecular weight of 2,000 or more.
5 . The optical film of claim 3 , wherein
the colored layer contains, as the singlet oxygen quencher, one of a dialkyl phosphate, dialkyl dithiocarbanate, benzenedithiol, or a transition metal complex thereof.
6 . The optical film of claim 1 , wherein
the colored layer further contains a third colorant that has, in a wavelength range of 400 to 780 nm, a wavelength of lowest transmittance in a range of 650 nm to 780 nm.
7 . The optical film of claim 1 , wherein
the colored material contains at least one or more compounds selected from a group consisting of compounds having one of a porphyrin structure, a merocyanine structure, a phthalocyanine structure, an azo structure, a cyanine structure, a squarylium structure, a coumarin structure, a polyene structure, a quinone structure, a tetradiporphyrin structure, a pyrromethene structure, and an indigo structure, and metal complexes thereof.
8 . The optical film of claim 1 , wherein
the functional layer contains an oxygen barrier layer having an oxygen permeability of 10 cc/m 2 ·day·atm or less.
9 . The optical film of claim 1 , wherein
the functional layer has a first layer and a second layer,
the first layer and the second layer are laminated in this order in a direction from the colored layer toward the transparent substrate, and a refractive index of the second layer is lower than a refractive index of the first layer.
10 . The optical film of claim 1 , wherein
the functional layer further comprises an antiglare layer.
11 . The optical film of claim 1 , wherein
the functional layer contains at least one of an antistatic layer containing an antistatic agent, and an antifouling layer having water repellency.
12 . A display device, comprising:
a light source; and
an optical film of claim 1 .
13 . The display device of claim 12 , wherein
the light source includes a plurality of light-emitting elements that emit light based on an image signal.
14 . A composition for forming a colored layer comprising an active energy ray-curable resin, a photopolymerization initiator, a black organic pigment, a colored material, an additive, and a solvent, wherein
the colored material contains
a first colorant that has a maximum absorption wavelength in a range of 470 nm or more and 530 nm or less, an absorption spectrum thereof having a half-width of 15 nm or more and 45 nm or less, and
a second colorant that has a maximum absorption wavelength in a range of 560 nm or more and 620 nm or less, an absorption spectrum thereof having a half-width of 15 nm or more and 55 nm or less, and
the additive contains a radical scavenger.