US3958994A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photosensitive diazo steel lithoplate structure
Assignee: CNA Holdings LLC
•
Filing: 1974-08-26
•
Granted: 1976-05-25
•
Expires: 1994-08-26
Abstract
Abstract A lithographic printing plate structure and method of manufacture, in which a support sheet of steel, normally subject to corrosion in a lithographic environment, such as a mild steel, is coated, preferably on both sides, with aluminum, zinc or an aluminum-zinc alloy to a thickness of about 1 to 3 mils, a polyvinyl phosphonic acid is disposed on the metal coating and a negative working diazo photo-sensitive layer is applied over the polyvinyl phosphonic acid coating.
Inventors
- 👤 Leo S. Burnett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 12:06
CPC Classifications
B; B32; B32B; B32B15/00; B32B15/01; B32B15/012; B32B15/013; B41; B41N; B41N1/00; B41N1/04; B41N1/08; B41N1/083; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/923; Y10S428/924; Y10S428/926; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12535; Y10T428/12542; Y10T428/12549; Y10T428/12736; Y10T428/1275; Y10T428/12757; Y10T428/12771; Y10T428/12861; Y10T428/12951; Y10T428/12972; Y10T428/31504; Y10T428/31678; Y10T428/31692
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
123 words
A lithographic printing plate structure, comprising a support sheet of steel, normally subject to corrosion in a lithographic environment, a metallurgically bonded coating of aluminum-zinc alloy in which the alloy comprises about 25 to 70% aluminum and about 75 to 30% zinc, on at least one side of said sheet of steel, said coating having a thickness in the range of about 0.5 to 3 mils, a coating of a polyvinyl phosphonic acid directly on said coating, and, directly on said polyvinyl phosphonic acid coating, a photosensitive layer comprising a diazo compound which upon exposure to actinic light provides photo-hardened areas in the exposed areas of the layer, whereby upon development of the layer with a solvent only the unexposed areas are removed.
Claim 2
Dependent Claim
123 words
A lithographic printing plate structure, comprising a support sheet of steel, normally subject to corrosion in a lithographic environment, a metallurgically bonded coating of aluminum-zinc alloy in which the alloy comprises about 25 to 70% aluminum and about 75 to 30% zinc, on at least one side of said sheet of steel, said coating having a thickness in the range of about 0.5 to 3 mils, a coating of a polyvinyl phosphonic acid directly on said coating, and, directly on said polyvinyl phosphonic acid coating, a photosensitive layer comprising a diazo compound which upon exposure to actinic light provides photo-hardened areas in the exposed areas of the layer, whereby upon development of the layer with a solvent only the unexposed areas are removed.
Claim 3
Dependent Claim
13 words
A structure in accordance with claim 1 wherein the steel is mild steel.
Claim 4
Dependent Claim
21 words
A structure in accordance with claim 1 wherein the metal coating is disposed on both sides of the sheet of steel.
References Cited (Backward Citations)
US951103A
Cited
US2214950A
Cited
US2697039A
Cited
US2994609A
Cited
US3201239A
Cited
GB936913A
Cited
US3220832A
Cited
US3197308A
Cited
US3348948A
Cited
US3343930A
Cited
US3393089A
Cited
US3679419A
Cited
DE2012288A1
Cited
US3865595A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-05-25 | 1979-11-24 | 1980-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-25 | 1983-11-24 | 1984-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-25 | 1987-11-24 | 1988-05-25 | $7700.00 | Window Closed / Lapsed |