Patent US3577920A successfully refreshed from Google Patents.
US3577920A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Metallic lithographic plate and method of making the same
Assignee: LONDON LITHO ALUMINUM CO Inc
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Filing: 1967-07-10
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Granted: 1971-05-11
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Expires: 1987-07-10
Abstract
Abstract Metallic lithographic plate for use in the copperized lithographic printing process, comprising a base layer of magnesium-aluminum alloy and a surface layer sheet of aluminum metallurgically bonded thereto under conditions of temperature and pressure which bring about both physical and chemical changes in said surface layer and place it in a hard tempered condition, the resulting ''''activated'''' aluminum surface improving the ease of depositing copper thereon and the durability and tenacity of the copper so deposited in image areas subsequent to development, and also preventing the decomposition of light sensitive diazo compounds in contact with said surface layer.
Inventors
- 👤 Melvyn London
- 👤 Guy Robert Smetters
- 👤 George Eugene Beck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:29
CPC Classifications
B; B41; B41N; B41N1/00; B41N1/04; B41N1/08; B41N1/083; B41N3/00; B41N3/08
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
59 words
The method of claim 1 wherein said baseplate is substantially pure aluminum having a magnesium content within the range of 0.4 percent to 6 percent by weight and said surface layer is substantially pure aluminum having a magnesium content of less than 0.3 percent by weight and has a thickness within the range of 0.00025 inch and 0.003 inch.
Claim 2
Dependent Claim
12 words
The metallic lithographic printing plate formed by the process of claim 2.
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) | 1974-05-10 | 1974-11-09 | 1975-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-10 | 1978-11-09 | 1979-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-10 | 1982-11-09 | 1983-05-11 | $7700.00 | Window Closed / Lapsed |