Laminated film and molded article, and production methods therefor
Provided is an after-cure type laminated film having a low reflectance. A laminated film comprising: a transparent support substrate, an uncured hard coat layer formed on at least one surface of the transparent support substrate, and an uncured optical interference layer formed on the uncured hard coat layer, wherein the uncured hard coat layer comprises an active energy ray-curable composition for forming a hard coat layer, the uncured optical interference layer comprises an active energy ray-curable composition for forming an optical interference layer, the transparent support substrate has a thickness of 50 μm or more and 600 μm or less, a stretch ratio of the laminated film at 160° C. is 50% or more, and the laminated film heat-treated at a temperature of 90° C. for 30 minutes has a minimum value R AH of a reflectance taken between wavelengths of 380 nm and 780 nm of 2% or less and measured from a side of the uncured optical interference layer.
1 . A laminated film comprising:
a transparent support substrate,
an uncured hard coat layer formed on at least one surface of the transparent support substrate, and
an uncured optical interference layer formed on the uncured hard coat layer, wherein
the uncured hard coat layer comprises an active energy ray-curable composition for forming a hard coat layer,
the uncured optical interference layer comprises an active energy ray-curable composition for forming an optical interference layer,
the transparent support substrate has a thickness of 50 μm or more and 600 μm or less,
a stretch ratio of the laminated film at 160° C. is 50% or more,
the laminated film heat-treated at a temperature of 90° C. for 30 minutes has a minimum value R AH of a reflectance taken between wavelengths of 380 nm and 780 nm of 2% or less and measured from a side of the uncured optical interference layer,
the composition for forming the optical interference layer comprises a first layer-forming component and low-refractive particles,
the first layer-forming component comprises a first reactive component having two or more polymerizable functional groups in one molecule,
the first reactive component comprises at least one selected from the group consisting of a first polymer having a weight-average molecular weight of more than 10,000, a first oligomer having a weight-average molecular weight of 10,000 or less, and a first monomer having a weight-average molecular weight of 10,000 or less, and
a content X of the low-refractive particles, a total content Y of the first oligomer and the first monomer, and a content Z of the first polymer satisfy the following relationship:
X
+
Y
+
Z
=
100
,
X
>
3
0
¯
,
Y
>
0
¯
,
Z
≥
0
,
and
Z
≤
1
/
2
X
-
15
,
provided that Y and Z are not 0 at the same time.
2 . The laminated film according to claim 1 , wherein
the minimum value R AH of the reflectance and a minimum value R BH of the reflectance of the laminated film before being heat-treated taken between the wavelengths of 380 nm and 780 nm and measured from the side of the uncured optical interference layer satisfy a relationship:
100
×
❘
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R
A
H
-
R
B
H
❘
"\[RightBracketingBar]"
/
R
B
H
≤
20
(
%
)
.
3 . The laminated film according to claim 1 , wherein the composition for forming a hard coat layer comprises a second layer-forming component,
the second layer-forming component comprises a second reactive component having two or more polymerizable functional groups in one molecule, and
the second reactive component comprises at least one of a second oligomer having a weight-average molecular weight of 10,000 or less and a second monomer having a weight-average molecular weight of 10,000 or less.
4 . The laminated film according to claim 3 , wherein the second reactive component further comprises a second polymer having a weight-average molecular weight of more than 10,000.
5 . The laminated film according to claim 3 , wherein a total content of the second oligomer and the second monomer is 25 parts by mass or more and 65 parts by mass or less based on 100 parts by mass of a solid content of the composition for forming the hard coat layer.
6 . The laminated film according to claim 1 , further comprising at least one uncured functional layer between the uncured hard coat layer and the uncured optical interference layer.
7 . The laminated film according to claim 1 , wherein a hardness H BC measured from an uncured optical interference layer side by a nanoindentation method is 0.1 GPa or more and 0.5 GPa or less.
8 . The laminated film according to claim 1 , wherein the laminated film irradiated with an active energy ray having an integral light quantity of 2000 mJ/cm 2 has a hardness H AC of 0.25 GPa or more and 0.7 GPa or less as measured from the side of the optical interference layer by a nanoindentation method.
9 . The laminated film according to claim 1 , wherein the uncured hard coat layer has a thickness of 2 μm or more and 30 μm or less.
10 . The laminated film according to claim 1 , wherein the uncured optical interference layer has a thickness of 15 nm or more and 200 nm or less.
11 . A formed article comprising the laminated film according to claim 1 cured.
12 . The formed article according to claim 11 , wherein
the hard coat layer is disposed on one main surface of the transparent support substrate, and
the formed article further comprises a decorative layer disposed on the other main surface of the transparent support substrate.
13 . The formed article according to claim 12 , further comprising a formed resin layer that covers at least part of the decorative layer.
14 . A method for manufacturing a laminated film, the method comprising:
a step of forming an uncured hard coat layer by applying an active energy ray-curable composition for forming a hard coat layer to one surface of a transparent support substrate having a thickness of 50 μm or more and 600 μm or less;
a step of forming an uncured optical interference layer by applying an active energy ray-curable composition for forming an optical interference layer to one surface of another support substrate; and
a lamination step of bonding a surface of the uncured hard coat layer on a side opposite from the transparent support substrate and a surface of the uncured optical interference layer on a side opposite from the other support substrate to obtain the laminated film, wherein
a stretch ratio of the laminated film at 160° C. is 50% or more,
the laminated film heat-treated at a temperature of 90° C. for 30 minutes has a minimum value R AH of a reflectance taken between wavelengths of 380 nm and 780 nm of 2% or less and measured from a side of the uncured optical interference layer,
the composition for forming the optical interference layer comprises a first layer-forming component and low-refractive particles,
the first layer-forming component comprises a first reactive component having two or more polymerizable functional groups in one molecule,
the first reactive component comprises at least one selected from the group consisting of a first polymer having a weight-average molecular weight of more than 10,000, a first oligomer having a weight-average molecular weight of 10,000 or less, and a first monomer having a weight-average molecular weight of 10,000 or less, and
a content X of the low-refractive particles, a total content Y of the first oligomer and the first monomer, and a content Z of the first polymer satisfy the following relationship:
X
+
Y
+
Z
=
100
,
X
>
3
0
¯
,
Y
>
0
¯
,
Z
≥
0
,
and
Z
≤
1
/
2
X
-
15
,
provided that Y and Z are not 0 at the same time.
15 . A method for manufacturing a formed article, the method comprising:
a decoration step of forming a decorative layer on another main surface of the transparent support substrate of the laminated film according to claim 1 ; and
a curing step of irradiating the laminated film with an active energy ray after the decoration step, wherein
the decoration step includes a heating step of heating the laminated film at 80° C. or more for 20 minutes or more.
16 . The method for manufacturing a formed article according to claim 15 , further comprising an injection molding step of, after the decoration step, making the optical interference layer face a mold and injecting a resin for molding toward the decorative layer.
17 . The method for manufacturing a formed article according to claim 16 , wherein
the mold imparts a three-dimensional shape to the laminated film, and
the method further comprises a preforming step of forming the laminated film into a shape conforming with the three-dimensional shape after the decoration step and before the injection molding step.