Process for producing optical article having anti-reflection film

Claim 1

A process for producing an optical article with an anti-reflection film, which comprises the successive steps of: (1) coating an optical article having a refractive index of less than 1.65, a first liquid composition containing an alcohol-dispersed antimony pentoxide sol having particle diameters of 20-100 mμ, a hydrolyzate of gamma-glycidoxypropyltrialkoxysilane, a curing agent and solvent, wherein the amount of the alcohol-dispersed antimony pentoxide sol is 55 to 85 mole %, calculated as Sb 2 O 5 , and the amount of the gamma-glycidoxypropyltrialkoxysilane is itself 45-15 mole %, and then heat curing the coated composition to form a first layer film of a high refractive index having an optical thickness of λ/4 (100-200 nm), and thereafter (2) coating on the first layer film of high refractive index formed in step (1), a second liquid composition containing a colloidal silica hydrolyzate of a gamma-glycidoxypropytrialkoxysilane, a hydrolyzate of a gamma-methacryloxypropyltrialkoxysilane, a curing agent and a solvent, provided that the molar ratio of the gamma-glycidoxypropyltrialkoxysilane itself to the gamma-methacryloxypropyltrialkoxysilane itself is from 1:1 to 9:1, that the hydrolyzates of both alkyloxysilanes are produced by simultaneous hydrolysis, and that the amount of the colloidal silica is 60 to 80 mole %, calculated as SiO 2 , and the total amount of the gamma-glycidoxypropyltrialkosilane and gamma-methacryloxypropyltrialkoxysilane themselves is 40 to 20 mole %, and then heat curing the coated composition to form a second layer film of low refractive index having an optical film thickness of λ/4 (100-200 nm).