Process for producing die roll

摘要

A production method of a mold roller for a roller nanoimprint apparatus for producing an optical element,the optical element comprising a nanostructure film including recesses and protrusions in nanometer size formed continuously on a surface of the nanostructure film,the nanostructure film including a nanostructure-free region free from the recesses and protrusions in nanometer size in both ends along a longitudinal direction of the nanostructure film,the nanostructure film further including a moth-eye structure including a plurality of conical protrusions each having a size smaller than a wavelength of visible light, andthe production method comprising the steps of:anodizing an aluminum tube in which a region other than a region where a concave pattern for forming the plurality of conical protrusions is to be formed is masked with a masking material, andetching the aluminum tube, the anodizing and the etching being repeated.