US4033919A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Desensitizing compositions for lithographic platemaking and printing which are aqueous solutions of copolymers of acrylamide with a carboxyl containing monomer and a desensitizing acidic additive
Assignee: EIDP Inc
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Filing: 1975-01-31
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Granted: 1977-07-05
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Expires: 1995-01-31
Abstract
Abstract A desensitizing composition comprises an aqueous solution comprising (i) a polymer containing structural units derived from acrylamide and from 1% by weight to 25% by weight of structural units containing carboxyl groups and (ii) desensitizing acidic material in an amount such that the pH of the solution is less than 5.5. The carboxyl group containing structural units may be derived from acrylic acid and/or an acrylic acid salt and the desensitizing acidic material may be phosphoric acid. The composition may be used as a substitute for gum arabic solution in lithographic plate making processes and lithographic printing processes.
Inventors
- 👤 Leslie Edward Lawson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:51
CPC Classifications
B; B41; B41N; B41N3/00; B41N3/08
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
58 words
A desensitising composition for use in lithographic plate making and lithographic printing which composition is an aqueous solution comprising (i) a polymer of acrylamide containing from 1% by weight to 25% by weight of structural units containing carboxyl groups and (ii) acidic desensitising material in an amount such that the pH of the solution is less than 5.5.
Claim 2
Dependent Claim
58 words
A desensitising composition for use in lithographic plate making and lithographic printing which composition is an aqueous solution comprising (i) a polymer of acrylamide containing from 1% by weight to 25% by weight of structural units containing carboxyl groups and (ii) acidic desensitising material in an amount such that the pH of the solution is less than 5.5.
Claim 3
Dependent Claim
20 words
A composition according to claim 1, in which the aqueous solution has a solids content of 0.1% to 20% w/v.
Claim 4
Dependent Claim
31 words
A composition according to claim 1, in which the aqueous solution has a solids content of up to 35% w/v for subsequent dilution for use in lithographic platemaking or lithographic printing.
Claim 5
Dependent Claim
37 words
A composition as claimed in claim 1 wherein the carboxyl group containing structural units of the polymer are derived from a substance selected from the group consisting of acrylic acid, an acrylic acid salt, and mixtures thereof.
Claim 6
Dependent Claim
40 words
A composition as claimed in claim 2 wherein the polymer has a molecular weight of about 140,000 and contains 10% by weight of carboxyl group containing structural units derived from sodium acrylate, the remaining structural units being derived from acrylamide.
Claim 7
Dependent Claim
54 words
A composition as claimed in claim 2 wherein the polymer has a molecular weight of about 200,000 and contains 3% by weight of carboxyl group containing structural units derived from acrylic acid and 18% by weight of carboxyl group containing structural units derived from sodium acrylate, the remaining structural units being derived from acrylamide.
Claim 8
Dependent Claim
98 words
A composition as claimed in claim 2 wherein said polymer is a mixture of a polymer which has a molecular weight of about 140,000 and which contains 10% by weight of carboxyl group containing structural units derived from sodium acrylate, the remaining structural units being derived from acrylamide and of a polymer which has a molecular weight of about 200,000 and which contains 3% by weight of carboxyl group containing structural units derived from acrylic acid and 18% by weight of carboxyl group containing structural units derived from sodium acrylate, the remaining structural units being derived from acrylamide.
Claim 9
Dependent Claim
15 words
A composition as claimed in claim 1 wherein the desensitising acidic material is phosphoric acid.
Claim 10
Dependent Claim
21 words
A composition as claimed in claim 1 wherein the aqueous solution has a solids content of from 0.1% to 35% w/v.
References Cited (Backward Citations)
US3373021A
Cited
US3560417A
Cited
US3761259A
Cited
US3619217A
Cited
US3734873A
Cited
US3839500A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-07-04 | 1981-01-03 | 1981-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-04 | 1985-01-03 | 1985-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-04 | 1989-01-03 | 1989-07-05 | $7700.00 | Window Closed / Lapsed |