US4022619A
Expired / Lapsed
US
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Composite developer-etch composition for chromium-plated lithographic printing plates
Assignee: Printing Developments Inc
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Filing: 1975-04-14
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Granted: 1977-05-10
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Expires: 1995-04-14
Abstract
Abstract A composite developer-etch composition for chromium-plated lithographic printing plates comprises an aqueous solution of aluminum chloride, a water-soluble chloride other than aluminum chloride, phosphoric acid, and an acid-stable water-soluble reducing agent; the composition having a particular specific gravity range.
Inventors
- 👤 Vincent A. Pagliaro
- 👤 Richard G. Walters
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:33
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/26; G03F7/30; G03F7/32
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
95 words
A composite developer-etch composition for chromium-plated lithographic printing plates which comprises an aqueous solution of from about 16% to about 22% by weight of aluminum chloride, from about 20% to about 26% by weight of a water-soluble chloride other than aluminum chloride, from about 2.2% to about 4.0% by weight of 85% strength phosphoric acid, from about 0.6% to about 1.4% by weight of acid-stable water-soluble alkali metal or alkali earth metal hypophosphite reducing agent and the balance water; said composition having a specific gravity at 70° F. of from about 1.4 to about 1.5
Claim 2
Dependent Claim
95 words
A composite developer-etch composition for chromium-plated lithographic printing plates which comprises an aqueous solution of from about 16% to about 22% by weight of aluminum chloride, from about 20% to about 26% by weight of a water-soluble chloride other than aluminum chloride, from about 2.2% to about 4.0% by weight of 85% strength phosphoric acid, from about 0.6% to about 1.4% by weight of acid-stable water-soluble alkali metal or alkali earth metal hypophosphite reducing agent and the balance water; said composition having a specific gravity at 70° F. of from about 1.4 to about 1.5
Claim 3
Dependent Claim
103 words
The composition defined by claim 1 which comprises an aqueous solution of from about 16% to about 22% by weight of aluminum chloride; from about 20% to about 26% by weight of a water-soluble chloride of a metal of Group I or Group II of the Mendeleeff Periodic Table; from about 2.2% to about 4.0% by weight of 85% strength phosphoric acid; from about 0.6% to about 1.4% by weight of an acid-stable water-soluble alkali metal or alkali earth metal hypophosphite reducing agent; and the balance water; said compositon having a specific gravity at 70° F. of from about 1.4 to about 1.5.
Claim 4
Dependent Claim
77 words
The composition defined by claim 2 which comprises an aqueous solution of from about 16% to about 22% by weight of aluminum chloride, from about 20% to about 26% by weight of zinc chloride, from about 2.2% to about 4.0% by weight of 85% strength phosphoric acid, from about 0.6% to about 1.4% by weight of sodium hypophosphite and the balance water; said composition having a specific gravity at 70° F. of from about 1.4 about 1.5
Claim 5
Dependent Claim
58 words
The composition defined by claim 3 which comprises an aqueous solution of about 18% by weight of aluminum chloride, about 24% by weight of zinc chloride, about 3% by weight of 85% strength phosphoric acid, about 0.7% by weight of sodium hypophosphite and the balance water; said composition having a specific gravity at 70° F. of about 1.4
Claim 6
Dependent Claim
58 words
The composition defined by claim 3 which comprises an aqueous solution of about 19% by weight of aluminum chloride, about 25% by weight of zinc chloride, about 3% by weight of 85% strength phosphoric acid, about 0.7% by weight of sodium hypophosphite and the balance water; said composition having a specific gravity at 70° F. of about l.4
Claim 7
Dependent Claim
58 words
The composition defined by claim 3 which comprises an aqueous solution of about 20% by weight of aluminum chloride, about 22% by weight of zinc chloride, about 4% by weight of 85% strength phosphoric acid, about 0.7% by weight of sodium hypophosphite and the balance water; said composition having a specific gravity at 70° F. of about 1.5.
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) | 1980-05-09 | 1980-11-08 | 1981-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-09 | 1984-11-08 | 1985-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-09 | 1988-11-08 | 1989-05-10 | $7700.00 | Window Closed / Lapsed |