OPTICAL FILM, OPTICAL FILM MANUFACTURING METHOD AND SURFACE LIGHT-EMITTING BODY
This optical film includes a diffraction grating layer made of a transparent material, and a concavo convex surface structure layer made of a transparent material. The surface light-emitting body includes the aforementioned optical film. This optical film manufacturing method involves supplying a second active energy ray curable composition between a substrate and a mold having a diffractive grating transfer part, irradiating second active energy rays to obtain a laminate having a diffractive grating layer on convex structure transfer part, and irradiating first active energy rays.
1 . An optical film comprising:
a surface relief structure layer that is composed of a first transparent material and has a relief structure; and
a diffraction grating layer composed of a second transparent material.
2 . The optical film according to claim 1 , wherein the second transparent material is a resin.
3 . The optical film according to claim 1 , wherein a refractive index of the second transparent material is from 1.30 to 1.80.
4 . The optical film according to claim 1 , wherein a pitch of a diffraction grating of the diffraction grating layer is from 0.2 to 5 μm.
5 . The optical film according to claim 1 , wherein a height of a diffraction grating of the diffraction grating layer is from 0.4 to 5 μm.
6 . The optical film according to claim 1 , wherein the first transparent material is a resin.
7 . The optical film according to claim 1 , wherein the relief structure of the surface relief structure layer is spherical.
8 . The optical film according to claim 1 , wherein the surface relief structure layer further contains light-diffusing fine particles.
9 . The optical film according to claim 8 , wherein a volume average particle size of the light-diffusing fine particles is from 1 to 10 μm.
10 . The optical film according to claim 8 , wherein a content of the light-diffusing fine particles in the surface relief structure layer is from 1 to 50% by mass.
11 . The optical film according to claim 1 , wherein a difference in refractive index between the second transparent material and the first transparent material is from 0.01 to 0.30.
12 . The optical film according to claim 1 , wherein a ratio of a pitch of the relief structure of the surface relief structure layer to a pitch of a diffraction grating of the diffraction grating layer is from 10 to 100.
13 . The optical film according to claim 1 , wherein the optical film further comprises a substrate, and the diffraction grating layer and the surface relief structure layer are sequentially stacked on the substrate.
14 . A surface light-emitting body comprising the optical film according to claim 1 .
15 . The surface light-emitting body according to claim 14 , wherein the surface light-emitting body further comprises an EL light-emitting device fabricated by sequentially stacking a cathode, a light-emitting layer, an anode, and a substrate, and the optical film is stacked on the substrate of the EL light-emitting device so that the surface relief structure layer becomes a light-exiting surface.
16 . A optical film manufacturing method comprising:
supplying a second active energy ray-curable composition between a substrate and a die having a transfer portion of a diffraction grating and irradiating the composition with a second active energy ray to obtain a stacked body having a diffraction grating layer on the substrate; and
supplying a first active energy ray-curable composition between the stacked body thus obtained and a die having a transfer portion of a relief structure and irradiating the composition with a first active energy ray.