Process for forming a microstructured transmission and reflectance modifying coating
AssigneeMinnesota Mining and Manufacturing Company
InventorsGary L. Dorer, Valdis Mikelsons
Life of this patent
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Abstract
A process for forming single layer coatings that render a surface more light transmitting and less light reflecting without an attendant increase in diffuse scattering, which includes the steps of depositing a thin metal film on the surface and totally converting the thin metallic film to either an oxide and/or hydroxide microstructured layer by chemical or a combination of chemical and electrochemical methods. Uniform optical properties are exhibited over large angles of incidence and an extremely broad range of wavelengths.
Claims4
A method of forming an article having a substantially antireflecting surface such that the specular reflection of visible light directed thereat is appreciably reduced, comprising the steps of
- (a) coating onto a substrate a thin-film having a thickness of at least 5 nanometers of a metal selected from the group consisting of aluminum, magnesium and zinc or alloys thereof, and
- (b) exposing the metallic thin-film to water for a duration, and at a temperature sufficient to convert the metallic thin-film to be an oxide or hydroxide coating, such that the converted coating is characterized by a plurality of randomly positioned discrete leaflets of varying heights and shapes, which leaflets extend from said surface a distance of not less than 20 nanometers nor more than the wavelength of light, and the bases of which contact the bases of substantially all adjacent leaflets, resulting in a total specular reflectivity of visible light incident normal to the surface coating of less than one percent.
Dependencies are inferred from the claim text.