Non-ferrous lithographic printing plate glassing composition
Abstract
Abstract Non-ferrous lithographic printing plates, and especially those in which the hydrophobic image areas are constituted by photosensitive polymers, are desensitized by application to the metal surface of the developed plate of an aqueous desensitizing solution comprising a phosphate glass such as sodium hexametaphosphate, preferably in admixture with a fluoride salt, such as sodium fluoride. The aqueous composition is maintained at a pH in the range of pH 5-7 by a water-soluble phosphorus acid, such as phosphoric acid. The treatment can be performed at room temperature and permits the hydrophylic areas of the printing plate to be maintained upon storage without special protection. The treatment can also be used as a fountain solution in a press fountain.
Inventors
- 👤 J Harper
Bibliographic Details
Claims Analysis
Total Claims: 2References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-26 | 1977-05-28 | 1977-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-26 | 1981-05-28 | 1981-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-26 | 1985-05-28 | 1985-11-27 | $7700.00 | Window Closed / Lapsed |