US4252843A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for forming a microstructured transmission and reflectance modifying coating
Assignee: 3M Co
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Filing: 1979-11-05
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Granted: 1981-02-24
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Expires: 1999-11-05
Abstract
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.
Inventors
- 👤 Gary L. Dorer
- 👤 Valdis Mikelsons
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:49
CPC Classifications
C; C23; C23C; C23C14/00; C23C14/06; C23C14/14; C03; C03C; C03C17/00; C03C17/22; C03C17/23; C03C17/27; C23C14/58; C23C14/5846; C23C14/5853; F; F24; F24S; F24S70/00; F24S70/20; F24S70/225; F24S70/25; G; G02; G02B; G02B1/00; G02B1/10; G02B1/11; G02B1/118; G02B3/00; G02B3/02; G02B3/08; H; H10; H10F; H10F77/00; H10F77/70; C03C2217/00; C03C2217/20; C03C2217/21; C03C2217/214; C03C2217/216; C03C2217/228; C03C2218/00; C03C2218/10; C03C2218/15; C03C2218/30; C03C2218/32; C03C2218/322; Y; Y02; Y02E; Y02E10/00; Y02E10/40; Y02E10/50
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
161 words
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.
Claim 2
Independent Claim
161 words
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.
Claim 3
Dependent Claim
46 words
A method according to claim 1, wherein the exposing step results in an oxide coating having a reflectivity less than 1.0% and which if on a transparent substrate such that internal absorption may be appreciably ignored, the article exhibits a transmissivity of not less than 98%.
Claim 4
Dependent Claim
51 words
A method according to claim 1, wherein the step of exposing the thin-film comprises applying to the thin-film a layer of a wetting agent and exposing the film to saturated steam for a duration ranging between 0.5 and 60 minutes and at a temperature ranging between 85° C. and 98° C.
Claim 5
Dependent Claim
40 words
A method according to claim 1, wherein the step of exposing the thin-film comprises immersing the thin-film-substrate combination in an aqueous oxidizing solution at a temperature of not less than 25° C. for a duration of at least 0.5 minutes.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-02-24 | 1984-08-25 | 1985-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-24 | 1988-08-25 | 1989-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-24 | 1992-08-25 | 1993-02-24 | $7700.00 | Window Closed / Lapsed |