US3876468A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for reclaiming glass articles
Assignee: Hitachi Ltd
•
Filing: 1973-03-19
•
Granted: 1975-04-08
•
Expires: 1993-03-19
Abstract
Abstract An aqueous solution containing hydrofluoric acid and tannic acid was found useful as a glass cleaning composition in reclaiming clean glass panel from a defective panel rejected during manufacture of a phospor screen for color picture tube. The composition is superior to conventional compositions not only in cleaning efficiency but also in operational safety because of lower hydrofluoric acid concentration and lower treating temperature.
Inventors
- 👤 Yoichi Oba
- 👤 Saburo Nonogaki
- 👤 Mitsuru Oikawa
- 👤 Kiyoshi Miura
- 👤 Yoshifumi Tomita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 00:11
CPC Classifications
C; C03; C03C; C03C23/00; C03C23/0075; H; H01; H01J; H01J29/00; H01J29/02; H01J29/10; H01J29/18; H01J29/24
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
39 words
A METHOD FOR RECLAIMING A GLASS PANEL FOR USE AS THE PHOSPHOR SCREEN OF A COLOR PICTURE TUBE, WHICH COMPRISES TREATING THE GLASS PANEL WITH A GLASS CLEANING COMPOSITION COMPRISING AN AQUEOUS SOLUTION OF HYDROFLUORIC ACID AND TANNIC ACID.
Claim 2
Dependent Claim
24 words
A method according to claim 1, wherein the concentration in said solution of hydrofluoric acid is 0.01 to 10 weight % and the concentration
Claim 3
Dependent Claim
21 words
A method according to claim 1, wherein said glass cleaning composition consists essentially of an aqueous solution of hydrofluoric acid and
Claim 4
Dependent Claim
24 words
A method according to claim 3, wherein the concentration in said solution of hydrofluoric acid is 0.01 to 10 weight % and the concentration
Claim 5
Independent Claim
33 words
A method for reclaiming a glass article including a glass surface having a photoresist film thereon comprising contacting the glass article with a composition comprising an aqueous solution of hydrofluoric acid and tannic
Claim 6
Dependent Claim
24 words
A method according to claim 5, wherein the concentration in said solution of hydrofluoric acid is 0.01 to 10 weight % and the concentration
Claim 7
Dependent Claim
24 words
A method according to claim 6, wherein the concentration in said solution of hydrofluoric acid is from 0.25 to 1 weight % and the
Claim 8
Dependent Claim
13 words
A method according to claim 5, wherein the glass article is immersed in
Claim 9
Dependent Claim
12 words
A method according to claim 5, wherein said composition is sprayed on
Claim 10
Dependent Claim
11 words
A method according to claim 5 further comprising rinsing the glass
Claim 11
Dependent Claim
11 words
A method according to claim 5 wherein said glass article further
Claim 12
Dependent Claim
12 words
A method according to claim 11, wherein said carbon film is black
Claim 13
Dependent Claim
13 words
A method according to claim 5, wherein said photoresist film is a the
Claim 14
Dependent Claim
12 words
A method according to claim 5, wherein said photoresist film is a
Claim 15
Dependent Claim
22 words
A method according to claim 5, wherein said composition consists essentially of an aqueous solution 2 of hydrofluoric acid and tannic acid.
Claim 16
Dependent Claim
24 words
A method according to claim 15, wherein the concentration in said solution of hydrofluoric acid is 0.01 to 10 weight % and the concentration
Claim 17
Dependent Claim
25 words
A method according to claim 16, wherein said glass article is contacted with said composition for sufficient time to substantially completely remove said photoresist film.
References Cited (Backward Citations)
US3527628A
Cited
US3673094A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |