Resin composition and display unit
A thin display unit that incorporates a high-luminance, high-contrast display part that is free of image detects caused by the deformation of the display part is provided. The display unit of the present invention includes an image display part 2 and a light-transmitting protective part 3 arranged on the image display part 2 . A cured resin layer 5 is arranged between the display part 2 and the protective part 3 . The cured resin layer 5 has a transmittance of 90% or higher in the visible range and a storage modulus at 25° C. of 1×10 7 Pa or less. The cured resin layer 5 is formed from a resin composition that has a cure shrinkage of 5% or less.
1. An image display unit comprising:
an image display part;
a light-transmitting protective part arranged on the image display part; and
a cured resin layer arranged between the image display part and the protective part,
wherein:
the cured resin layer is formed of a photocurable resin composition comprising:
at least one polymer selected from the group consisting of polyurethane acrylate, polyisoprene acrylate, ester of polyisoprene acrylate, hydrogenated terpine resin, and butadiene polymer;
at least one acrylate monomer selected from the group consisting of isobornyl acrylate, dicyclopentenyloxyethyl methacrylate, and 2-hydroxybutyl methacrylate; and
at least one photopolymerization initiator;
the cured resin layer has:
a transmittance of 90% or higher in the visible range,
a storage modulus at 25° C. of 1×10 7 Pa or less, and
a cure shrinkage of 0 to 2.0%; and
curing of the resin composition imparts an average surface roughness of 6 nm or less to a surface of the protective part or a surface of the image display part.
2. The image display unit according to claim 1 , wherein the at least one photopolymerization initiator comprises a photopolymerization initiator for the visible range together with a photopolymerization initiator for the ultraviolet range.
3. The image display unit according to claim 1 , wherein the cured resin layer has a thickness of from 50 μm to 200 μm.
4. The image display unit according to claim 1 , wherein the image display part is a liquid crystal display panel.
5. The image display unit according to claim 1 , wherein the protective part is formed of an acrylic resin.
6. The image display unit according to claim 1 , wherein the protective part is formed of an optical glass.
7. The image display unit according to claim 1 , wherein the storage modulus at 25° C. of the cured resin layer is in a range of from 1×10 3 to 1×10 6 Pa.
8. A method of producing an image display unit comprising an image display part, a light-transmitting protective part arranged on the image display part, and a cured resin layer arranged between the image display part and the protective part, comprising:
providing a photocurable resin composition between the image display part and the protective part, the photocurable resin composition comprising:
a butadiene polymer,
at least one acrylate monomer selected from the group consisting of isobornyl acrylate, dicyclopentenyloxyethyl methacrylate, and 2-hydroxybutyl methacrylate, and
a photopolymerization initiator for curing the at least one acrylate monomer, the photopolymerization initiator including a photopolymerization initiator for the visible range together with a photopolymerization initiator for the ultraviolet range; and
irradiating the photocurable resin composition with ultraviolet rays to cure the photocurable resin composition, thereby forming the cured resin layer having a transmittance of 90% or higher in the visible range, a storage modulus at 25° C. of from 1×10 3 to 1×10 6 Pa, and a cure shrinkage of 0 to 2.0%;
wherein curing of the resin composition imparts an average surface roughness of 6 nm or less to a surface of the image display part or a surface of the protective part.