Phosphor-containing film and backlight unit
A phosphor-containing film capable of suppressing deterioration of phosphor and capable of suppressing generation of luminescent spots and the reduction in luminance due to a defect of the resin layer. The film includes: a phosphor-containing layer having a resin layer which has impermeability to oxygen and is provided with a plurality of discretely arranged concave portions, and a plurality of fluorescent regions, each of which is arranged in the concave portion of the resin layer and contains a phosphor that deteriorates through a reaction with oxygen when exposed to oxygen; and a first substrate film and a second substrate film, which are respectively laminated on one main surface and the other main surface of the phosphor-containing layer, in which the fluorescent regions contain a binder and quantum dots serving as the phosphor.
1. A phosphor-containing film comprising:
a phosphor-containing layer having a resin layer which has impermeability to oxygen and is provided with a plurality of discretely arranged concave portions, and a plurality of fluorescent regions, each of which is arranged in the concave portion formed in the resin layer and contains a phosphor that deteriorates through a reaction with oxygen in the case of being exposed to oxygen; and
a first substrate film laminated on one main surface of the phosphor-containing layer and a second substrate film laminated on the other main surface of the phosphor-containing layer,
wherein the fluorescent regions contain the phosphor and a binder,
the resin layer has a modulus of elasticity of 0.5 GPa or more and 10 GPa or less,
a depth h of the concave portion of the resin layer is 1 μm or more and 100 μm or less,
a width t between adjacent fluorescent regions is 5 μm or more and 300 μm or less,
an aspect ratio h/t of the depth h to the width t between adjacent fluorescent regions is less than 3.0, and
a connecting portion between one of the first substrate film and the second substrate film and the side surface of the concave portion of the resin layer, and a connecting portion between the main surface of the resin layer on the other substrate film side and the side surface of the concave portion have a radius of curvature of 5 μm or more and 200 μm or less.
2. The phosphor-containing film according to claim 1 , wherein the concave portion of the resin layer has a depth h of 10 μm or more and 80 μm or less.
3. The phosphor-containing film according to claim 1 , wherein the resin layer has an oxygen permeability of 10 cc/(m 2 ·day·atm) or less.
4. The phosphor-containing film according to claim 1 , wherein the binder is formed of a photocurable composition or a thermosetting composition, and contains a polymer dispersant for dispersing the phosphor in the binder.
5. The phosphor-containing film according to claim 1 , wherein the first substrate film and the second substrate film have an oxygen permeability of 1 cc/(m 2 ·day·atm) or less.
6. The phosphor-containing film according to claim 1 , wherein the resin layer contains scattering particles.
7. The phosphor-containing film according to claim 1 , wherein the fluorescent region is a regular polygon in plan view.
8. The phosphor-containing film according to claim 1 , wherein, in the phosphor-containing layer, the fluorescent region is surrounded by the resin layer and a fluorescent region including a phosphor which has deteriorated through a reaction with oxygen by exposure to oxygen.
9. A backlight unit comprising:
a wavelength converting member including the phosphor-containing film according to claim 1 ; and
at least one of a blue light emitting diode or an ultraviolet light emitting diode.