Curable composition for forming low refractive index film, low refractive index film, optical device, and method for producing low refractive index film

Abstract

To provide a curable composition for forming a low refractive index film of which a cured film excellent in heat resistance can be formed. A curable composition for forming a low refractive index film containing a hollow filler (A), a polymerizable compound (B), and a polymerization initiator (C), and not containing an alkali-soluble resin. The polymerizable compound (B) includes a compound (B1) having 5 or more polymerizable functional groups and a compound (B2) having 1 or more and 3 or less polymerizable functional groups. A ratio (B1/B2) of a mass of the compound (B1) to a mass of the compound (B2) is 0.25 or more and 3 or less.

Dependencies are inferred from the claim text.