Film having low refractive index film and method for producing the same, anti-reflection film and method for producing the same, coating liquid set for low refractive index film, substrate having microparticle-laminated thin film and method for producing the same, and optical member

Abstract

Provided is a film having a low refractive index, which can be formed under normal temperature and pressure while obtaining a lower refractive index, has excellent adhesion with a solid substrate, and does not lose geometric optical properties, such as the diffusibility or light-harvesting capability attributed to the microstructure. Also disclosed is a method for producing the same. The film having a low refractive index is obtained by causing an electrolyte polymer and microparticles to be alternately adsorbed on the surface of a solid substrate and bringing the resulting microparticle-laminated film into contact with a silicon compound solution in order to bond the solid substrate with microparticles and microparticles with microparticles. The silicon compound solution is selected from (1) the hydrolysis product of alkoxysilane (I) wherein the functional groups are formed from hydrolyzable groups and non-hydrolyzable organic groups, and the condensation reaction product thereof, (2) the hydrolysis product of a mixture of alkoxysilane (I) and alkoxysilane (II) wherein the functional groups are formed from hydrolyzable groups alone, and the condensation reaction product thereof; and (3) a mixture of hydrolysis product and condensation product thereof according to (1) and alkoxysilane (II).