US4728597A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Desensitizing solution for lithographic printing plates
Assignee: CNA Holdings LLC
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Filing: 1987-02-17
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Granted: 1988-03-01
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Expires: 2007-02-17
Abstract
Abstract The invention provides an organic solvent free, phosphate free, lithographic desensitizing composition which comprises: (a) from about 0.1% to about 20.0% by weight of the composition of a copolymer of polymethyl vinyl ether and maleic acid having the formula ##STR1## which has a molecular weight in an amount of from about 20,000 to about 70,000; and (b) from about 0.1% to about 20.0% by weight of the composition of a desensitizing component comprising one or more hydroxy carboxylic acids or salts; and (c) sufficient water to formulate a desensitizing composition; and (d) sufficient base to adjust the pH of the composition into the range of from about 6.5 to about 7.5.
Inventors
- 👤 Shane Hsieh
- 👤 Wayne A. Mitchell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:45
CPC Classifications
B; B41; B41N; B41N3/00; B41N3/08
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
84 words
A method for treating an imagewise exposed lithographic printing plate containing a light sensitive diazo compound which comprises removing the non-image portions of said plate and then contacting said plate with an organic solvent free, phosphate free, lithographic desensitizing composition which comprises: (a) from about 0.1% to about 20.0% by weight of the composition of a copolymer of polymethyl vinyl ether and maleic acid having the formula ##STR5## which has a molecular weight in an amount of from about 20,000 to about 70,000; and
Claim 2
Independent Claim
84 words
A method for treating an imagewise exposed lithographic printing plate containing a light sensitive diazo compound which comprises removing the non-image portions of said plate and then contacting said plate with an organic solvent free, phosphate free, lithographic desensitizing composition which comprises: (a) from about 0.1% to about 20.0% by weight of the composition of a copolymer of polymethyl vinyl ether and maleic acid having the formula ##STR5## which has a molecular weight in an amount of from about 20,000 to about 70,000; and
Claim 3
Dependent Claim
26 words
(b) from about 0.1% to about 20.0% by weight of the composition of a desensitizing component comprising one or more hydroxy carboxylic acids or salts; and
Claim 4
Dependent Claim
26 words
(b) from about 0.1% to about 20.0% by weight of the composition of a desensitizing component comprising one or more hydroxy carboxylic acids or salts; and
Claim 5
Dependent Claim
9 words
(c) sufficient water to formulate a desensitizing composition; and
Claim 6
Dependent Claim
9 words
(c) sufficient water to formulate a desensitizing composition; and
Claim 7
Dependent Claim
20 words
(d) sufficient base to adjust the pH of the composition into the range of from about 6.5 to about 7.5.
Claim 8
Dependent Claim
20 words
(d) sufficient base to adjust the pH of the composition into the range of from about 6.5 to about 7.5.
Claim 9
Dependent Claim
40 words
The method of claim 1 wherein component (b) comprises one or more compounds selected from the group consisting of citric acid, sodium citrate, glycolic acid, tartaric acid, D.L. glyceric acid, malic acid, 4-hydroxy butyric acid, L-tartaric acid and mucic acid.
Claim 10
Dependent Claim
25 words
The method of claim 1 wherein said component (d) comprises one or more compounds selected from the group consisting of sodium, lithium and potassium hydroxide.
Claim 11
Dependent Claim
10 words
The method of claim 1 further comprising a dispersing agent.
Claim 12
Dependent Claim
34 words
The method of claim 4 wherein said dispersing agent comprises one or more compounds selected from the qroup consisting of water soluble polyethylene glycols, glycerin and potassium salts of polymerized alkyl naphthalene sulfonic acids.
Claim 13
Dependent Claim
28 words
The method of claim 1 wherein component (a) is present in an amount of from about 0.5% to about 10.0% based on the weight of the desensitizing composition.
Claim 14
Dependent Claim
26 words
The method of claim 1 wherein component (b) is present in an amount of from about 0.5% 0.5% to about 10.0% by weight of the composition.
Claim 15
Dependent Claim
21 words
The method of claim 1 wherein said composition has a pH in the range of from about 7.0 to about 7.5.
Claim 16
Dependent Claim
28 words
The method of claim 4 wherein said dispersing agent is present in an amount of from about 0.1% to about 10.0% based on the weight of the composition.
Claim 17
Dependent Claim
97 words
The method of claim 4 wherein said component (a) is present in an amount of from about 1.0% to about 5.0%; and said component (b) is sodium citrate and is present in an amount of from 1.0% to about 5.0%; and component (d) is potassium hydroxide in an amount sufficient to give the desensitizing composition a pH of from about 7.0 to about 7.2; and said dispersing agent is a potassium salt of a polymerized alkyl naphthalene sulfonic acid in an amount of from about 0.5 to about 5.0%, based on the weight of the desensitizing composition.
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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) | 1991-03-01 | 1991-08-31 | 1992-03-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-01 | 1995-08-31 | 1996-03-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-01 | 1999-08-31 | 2000-03-01 | $7700.00 | Window Closed / Lapsed |