US3616098A
Expired / Lapsed
US
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Method of producing glare-reducing glass surface
Assignee: Dearborn Glass Co
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Filing: 1968-03-18
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Granted: 1971-10-26
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Expires: 1988-03-18
Abstract
Abstract An improved glare-reducing glass surface is produced by including an undissolved inorganic salt of small crystal size, e.g., in the range of 10-50 microns in diameter and 2-10 micron in height, in the etching bath of an etching process. The etching process involves cleaning the glass surface, etching in a hydrofluoric acid bath or similar acid bath containing the undissolved salt by virtue of a saturated condition of the bath. Saturation of the bath is usually accomplished by ammonium bifluoride or other salt. After etching, the surface is properly polished and cleaned. The preferred, inorganic salt crystals are crystals of potassium bifluoride, sodium bifluoride, and calcium phosphate.
Inventors
- 👤 Joseph W Falls
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 18:22
CPC Classifications
C; C03; C03C; C03C15/00; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24355; Y10T428/31
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
24 words
The method of claim 1 wherein said amount of the smaller crystal size salt is in the range of 0.5 to 5 weight percent.
Claim 2
Dependent Claim
13 words
The method of claim 1 wherein said smaller crystal salt is potassium bifluoride.
Claim 3
Dependent Claim
149 words
In a method for etching glass surfaces containing silica for producing glare-reduced glass wherein the glass is subjected to etching involving the action of a hydrofluoric acid etching bath saturated with a relatively large crystal salt having a crystal size for normally producing protuberances on the glass surface 5-20 microns in height and 25-100 microns in diameter and comprising ammonium bifluoride, the improvement which comprises including in said bath from about 0.1 to about 20 weight percent of an inorganic salt having an ultimate crystal size in the range of about 2-10 microns in height and about 10-50 microns in diameter and selected from the class consisting of sodium bifluoride, potassium bifluoride and calcium phosphate, said etching bath comprising 1-20 weight percent hydrofluoric acid (based on 70 percent HF), 10-50 weight percent bifluoride crystals, 0-50 weight percent diethylene glycol, 10-50 weight percent water, and 0.1-20 weight percent potassium bifluoride.
Claim 4
Dependent Claim
21 words
The method of claim 4 wherein the weight percents of said five ingredients are seriatim 5-10, 20-40, 20-30, 25-45 and 0.5-5.
Claim 5
Dependent Claim
18 words
The method of claim 1 wherein said cleaning operation comprises washing the glass surface with dilute hydrofluoric acid.
Claim 6
Dependent Claim
31 words
The method of claim 1 wherein said polishing operation comprises dipping the glass recovered from the etching bath into a polishing bath comprising an aqueous hydrofluoric acid and sulfuric acid bath.
Claim 7
Dependent Claim
18 words
The method of claim 7 including the step of rinsing the glass after recovery from the polishing bath.
Claim 8
Dependent Claim
56 words
The method of claim 1 wherein said etching operation is repeated at least once until the protuberances of the desired size, over 50 percent of the protuberances having a height in the range of 2 to 10 microns and a diameter in the range of 10 to 50 microns, are formed uniformly over the glass surface.
Claim 9
Dependent Claim
33 words
A substantially nonreflective transparent article made by the method of claim 1 and comprising a body of glass having a glare-reduced, etched and polished surface defined by protuberances of glass at said surface.
Claim 10
Dependent Claim
43 words
The article of claim 10 wherein said protuberances are defined by depressions of silica removal from a smooth glass surface, said depressions being the general size and shape of inorganic salt crystal surface portions having a height and diameter in said restrictive ranges.
Claim 11
Dependent Claim
30 words
The article of claim 10 wherein a major amount of the protuberances have a height in the range of 2-10 microns and a diameter in the range of 10-50 microns.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-10-25 | 1975-04-26 | 1975-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-25 | 1979-04-26 | 1979-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-25 | 1983-04-26 | 1983-10-26 | $7700.00 | Window Closed / Lapsed |