Substrate having rugged structure obtained from hydrophobic sol/gel material
View Patent ↗There are provided a fine concave-convex structure substrate which is hydrophobic and excellent in heat resistance, a solution used for producing the concave-convex structure substrate, and a method for producing the concave-convex structure substrate. The concave-convex structure substrate having the concave-convex structure includes a concave-convex structure layer made of a sol-gel material, and a contact angle of water on the sol-gel material in a flat and smooth film shape is not less than 80°. The concave-convex structure substrate according to the present invention has a hydrophobic surface, and thus, in the element in which the concave-convex structure substrate is incorporated, moisture adsorption onto the surface of the concave-convex structure substrate can be prevented, thereby making it possible to lengthen a service life of the element.
1. A concave-convex structure substrate, comprising:
a substrate; and
a concave-convex structure layer made of silica obtained by baking a solution comprising a sol-gel material and formed on the substrate,
wherein the sol-gel material comprises:
a composition comprising tetraalkoxysilane and dialkoxysilane, the dialkoxysilane having an amount of 15 to 35 mol %, or
a composition comprising at least one selected from the group consisting of tetraalkoxysilane, trialkoxysilane, and dialkoxysilane, and further comprising a fluorine-containing alkoxysilane, the fluorine-containing alkoxysilane having an amount of 0.1 mol % or more and less than 1 mol %, and
wherein a contact angle of water on a flat and smooth film made of the silica obtained by baking the solution containing the sol-gel material is not less than 80°.
2. The concave-convex structure substrate according to claim 1 , wherein:
the dialkoxysilane is dimethyldiethoxysilane,
the tetraalkoxysilane is tetraethoxysilane, and
the trialkoxysilane is methyltriethoxysilane or phenyltriethoxysilane.
3. The concave-convex structure substrate according to claim 1 , wherein the concave-convex structure substrate is an optical substrate.
4. A method for producing an organic light emitting diode, comprising:
successively stacking a transparent electrode, an organic layer, and a metal electrode on the concave-convex surface of a diffraction grating substrate having a concave-convex surface,
wherein the concave-convex structure substrate as defined in claim 1 is used as the diffraction grating substrate.
5. A method for producing the concave-convex structure substrate, comprising:
coating a substrate with a solution containing a sol-gel material to form a coating film;
drying the coating film;
pressing a roll-shaped mold having a concave-convex pattern against the dried coating film so as to press the concave-convex pattern against the coating film;
releasing the mold from the coating film; and
baking the coating film to which the concave-convex pattern has been transferred to obtain a concave-convex structure layer made of silica,
wherein the sol-gel material comprises:
a composition comprising tetraalkoxysilane and dialkoxysilane, the dialkoxysilane having an amount of 15 to 35 mol %, or
a composition comprising at least one selected from the group consisting of tetraalkoxysilane, trialkoxysilane, and dialkoxysilane, and further comprising a fluorine-containing alkoxysilane, the fluorine-containing alkoxysilane having an amount of 0.1 mol % or more and less than 1 mol % in the composition, and
wherein a contact angle of water on a flat and smooth film made of the silica obtained by baking the coating film is not less than 80°.