Patent US5513523A successfully refreshed from Google Patents.
US4332649A
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US
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Method of polishing glass ware with sulfuric acid and hydrofluoric acid
Assignee: Individual
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Filing: 1980-11-19
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Granted: 1982-06-01
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Expires: 2000-11-19
Abstract
Abstract The invention relates to a polishing method for pressed glass or ground glass articles. As is conventional, polishing is effected in a bath containing sulfuric acid and hydrofluoric acid. Rinsing with a sulfuric acid and/or water washing bath intervenes and follows the polishing process. According to the method of the invention, the sodium and/or potassium ions resulting from the dissolution of glass constituents are removed from the polishing bath by the following means: (a) by adding fluorosilicic acid to the polishing bath, precipitating the corresponding silicofluorides and filtering off the solid matter, (b) by electrolysis in a mercury cell with the formation of sodium- and/or potassium amalgam, (c) by electrolysis in a cell having a cation semi-permeable membrane or (d) with the aid of cation exchangers.
Inventors
- 👤 Erich Salzle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 15:15
CPC Classifications
C; C03; C03C; C03C15/00; C03C15/02; C03C15/025
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
61 words
A method of polishing glass articles comprising contacting said articles with a polishing bath containing sulfuric acid and hydrofluoric acid and subsequently rinsing the finally polished articles in a sulfuric acid washing bath and/or water washing bath, wherein during the polishing operation dissolved alkali metal ions selected from the group consisting of sodium and potassium are removed from the polishing bath.
Claim 2
Independent Claim
61 words
A method of polishing glass articles comprising contacting said articles with a polishing bath containing sulfuric acid and hydrofluoric acid and subsequently rinsing the finally polished articles in a sulfuric acid washing bath and/or water washing bath, wherein during the polishing operation dissolved alkali metal ions selected from the group consisting of sodium and potassium are removed from the polishing bath.
Claim 3
Dependent Claim
18 words
The method according to claim 1, wherein the alkali metal ions are continuously removed from the polishing bath.
Claim 4
Dependent Claim
18 words
The method according to claim 1, wherein the alkali metal ions are removed batch-wise from the polishing bath.
Claim 5
Dependent Claim
18 words
The method according to claim 1, wherein the alkali metal ions are removed intermittently from the polishing bath.
Claim 6
Dependent Claim
54 words
The method according to claim 1, wherein the removal of the alkali metal ions is achieved by adding to the polishing bath an amount sufficient of fluorosilicic acid to effect precipitation in said polishing bath of said sodium and potassium ions as sodium- and potassium-silicofluoride, without substantial excess, and separating the precipitated alkali silicofluorides.
Claim 7
Dependent Claim
26 words
The method according to claim 5, wherein an acid selected from the group consisting of phosphoric acid and acetic acid is added to the polishing bath.
Claim 8
Dependent Claim
29 words
The method according to claim 5, wherein an organic acid selected from the group consisting of malonic acid, oxalic acid and tartaric acid is added to the polishing bath.
Claim 9
Dependent Claim
33 words
The method according to claim 5, wherein an acid is added to the polishing bath selected from the group consisting of phosphoric acid, acetic acid and malonic acid, oxalic acid and tartaric acid.
Claim 10
Dependent Claim
19 words
The method according to claim 1, wherein the alkali metal ions are removed by electrolysis in a mercury cell.
Claim 11
Dependent Claim
25 words
The method according to claim 1, wherein the alkali ions are removed in an electrolytic cell whose electrodes are separated by a cation semi-permeable membrane.
Claim 12
Dependent Claim
19 words
The method according to claim 1, wherein the alkali metal ions are removed by means of a cation exchanger.
Claim 13
Dependent Claim
19 words
The method according to claim 1, wherein the polishing bath has a sulfuric acid concentration of 40 to 75%.
Claim 14
Dependent Claim
19 words
The method according to claim 12, wherein the polishing bath has a hydrofluoric acid concentration of 3 to 10%.
Claim 15
Dependent Claim
18 words
The method according to claim 13, wherein the polishing bath has a temperature of at least 70° C.
Claim 16
Dependent Claim
24 words
The method according to claim 1, wherein the sulfuric acid washing bath has a concentration of more than 67% H 2 SO 4 .
Claim 17
Dependent Claim
24 words
The method according to claim 15, wherein the sulfuric acid washing bath has a concentration of 68 to 72% H 2 SO 4 .
Claim 18
Dependent Claim
20 words
The method according to claim 15, wherein the sulfuric acid washing bath has a temperature of 55° to 65° C.
Claim 19
Dependent Claim
73 words
The method according to claim 1, wherein the polishing bath has a density which is kept constant and is controllable by determining the hydrofluoric acid concentration in the polishing bath through conductivity measurements, thereby allowing an automatic control of the polishing bath on the basis of the measured value, by introducing hydrofluoric acid when a minimum concentration is obtained and by stopping the supply of hydrofluoric acid when a maximum concentration is achieved.
Claim 20
Dependent Claim
13 words
The method according to claim 18, wherein the conductivity measurement is continuously performed.
Claim 21
Dependent Claim
13 words
The method according to claim 18, wherein the conductivity measurement is intermittently performed.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-05-31 | 1985-11-30 | 1986-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-05-31 | 1989-11-30 | 1990-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-05-31 | 1993-11-30 | 1994-06-01 | $7700.00 | Window Closed / Lapsed |