Fixer composition
Abstract
Abstract A PROCESS AND COMPOSITIONS FOR RAPIDLY DEVELOPING AND FIXING A HIGH CONTRAST, LOW SPEED PHOTOGRAPHIC FILM SUCH AS MICROFILM. THE FIRST STEP IN THE PROCESS COMPRISES CONTACTING AN EXPOSED PHOTOGRAPHIC FILM WITH AN ALKALINE DEVELOPER COMPOSITION COMPRISING (A) A MIXTURE OF HYDROQUINONE AND 1-PHENYL-3-PYRAZOLIDONE IN A WEIGHT RATIO OF FROM 15:1 TO 6:1 AS THE DEVELOPING AGENT, THE MIXTURE CONTAINED IN THE DEVELOPER COMPOSITION IN AN AMOUNT OF FROM 15 TO 30 GRAMS PER LITER; AND (B) POTASSIUM SULFITE AS PRESERVATIVE IN AN AMOUNT FROM 60 TO 120 GRAMS PER LITER. PREFERABLY, THE DEVELOPER COMPOSITION HAS A PH FROM ABOUT 10 TO 11 AND CONTAINS A RESTRAINER SUCH AS POTASSIUM BROMIDE IN AN AMOUNT OF FROM 2 TO 10 GRAMS PER LITER. FOLLOWED CONTACT WITH THE DEVELOPER COMPOSITION, THE DEVELOPED FILM IS PREFERABLY CONTACTED WITH A FIXER SUCH AS ONE COMPRISING FROM 200 TO 400 GRAMS PER LITER SODIUM THIOSULFATE CRYSTALS, 50 TO 100 GRAMS PER LITER OF POTASSIUM SULFITE AND 100 TO 200 GRAMS PER LITER OF AMMONIUM THIOCYANATE.
Inventors
- 👤 John R Kane
- 👤 Harry G Morse
Bibliographic Details
Claims Analysis
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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) | 1974-05-31 | 1974-11-30 | 1975-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-31 | 1978-11-30 | 1979-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-31 | 1982-11-30 | 1983-06-01 | $7700.00 | Window Closed / Lapsed |