Patent EP0024872A1 successfully refreshed from Google Patents.
EP0024872A1
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EP
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A method of treating exposed and developed radiation sensitive plates in lithographic printing plate production, compositions for use in the method, and the use of diazo eliminating compounds in improving the ink receptivity of lithographic printing images
Assignee: Agfa Gevaert NV
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Filing: 1980-08-19
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Granted: —
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Expires: 2000-08-19
Abstract
Abstract The ink receptivity of lithographic printing images obtained by exposing and developing radiation sensitive coatings based on diazo compounds is improved by treating the developed coating with a compound capable of eliminating diazo groups, such as acetoacetanilide, optionally in admixture with a lithographic desensitising material such as dextrin or gum arabic.
Inventors
- 👤 Allen Peter Gates
- 👤 Elizabeth Anne Dawson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 17:42
CPC Classifications
B; B41; B41N; B41N3/00; B41N3/08; G; G03; G03F; G03F7/00; G03F7/26; G03F7/40
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
71 words
A method of producing a lithographic printing plate from a radiation sensitive plate comprising a substrate having a radiation sensitive coating containing a diazo compound by image-wise exposing the radiation sensitive plate and developing the image-wise exposed plate to selectively remove the non-radiation struck areas of the coating from the substrate, characterised in that the developed plate is treated with a finishing composition comprising a compound capable of eliminating diazo groups.
Claim 2
Independent Claim
71 words
A method of producing a lithographic printing plate from a radiation sensitive plate comprising a substrate having a radiation sensitive coating containing a diazo compound by image-wise exposing the radiation sensitive plate and developing the image-wise exposed plate to selectively remove the non-radiation struck areas of the coating from the substrate, characterised in that the developed plate is treated with a finishing composition comprising a compound capable of eliminating diazo groups.
Claim 3
Dependent Claim
31 words
A method according to claim 1 wherein the compound capable of eliminating diazo groups is an azo coupling compound capable of entering into an azo coupling reaction with a diazo group.
Claim 4
Dependent Claim
27 words
A method according to claim 2 wherein the azo coupling compound is acetoacetanilide; 3-hydroxyacetoacetanilide; 4-chloro-2,5-dimethoxyacetoacetanilide; 4-morpholinoacetoacetanilide; N-(cyanoacetyl)morpholine; I-phenyl-3-methyl-5-pyrazolone; 2,3-dihydroxynaphthalene; 8-aminonaphthalene-2-sulphonic acid; 8-amino-l-naphthol-3,6-disulphonic acid; m-phenylene diamine or phloroglucinol.
Claim 5
Dependent Claim
46 words
A method according to claim 1 wherein the compound capable of eliminating diazo groups is ascorbic acid; hypophosphorous acid, a titanous salt; a chromous salt; a stannous salt; sodium hydro sulphite; sodium stannite; hydroquinone; sodium hypochlorite; cuprous chloride; an alkali metal iodide; potassium xanthate or benzoquinone.
Claim 6
Independent Claim
19 words
A method according to any one of the preceding claims wherein the finishing solution includes a lithographic desensitising material.
Claim 7
Dependent Claim
40 words
A plate finishing composition for treating an exposed and developed radiation sensitive plate in lithographic printing plate production and comprising a lithographic desensitising material and water characterised in that the composition additionally includes a compound capable of eliminating diazo groups.
Claim 8
Dependent Claim
40 words
A plate finishing composition for treating an exposed and developed radiation sensitive plate in lithographic printing plate production and comprising a lithographic desensitising material and water characterised in that the composition additionally includes a compound capable of eliminating diazo groups.
Claim 9
Dependent Claim
25 words
A composition as claimed in Claim 6 wherein said compound is a compound capable of entering into an azo coupling reaction with a diazo group.
Claim 10
Dependent Claim
28 words
A composition as claimed in claim 7 wherein said compound is acetoacetanilide; 3-hydroxyacetoacetanilide; 4-chloro-2,5-dimethoxyacetoacetanilide; 4-morpholinoacetoacetanilide; N-acetoacetylbenzylamine; N,N'- bisacetoacetylethylene diamine; N-(cyanoacetyl) morpholine; or 1-phenyl-3-methyl-5-pyrazolone; and the composition is alkaline.
Claim 11
Dependent Claim
18 words
A composition as claimed in claim 7 wherein said compound is m-phenylene diamine and the composition is acidic.
Claim 12
Dependent Claim
49 words
A composition as claimed in claim 6 wherein said compound is 2,3-dihydroxynaphthalene; 8-aminonaphthalene-2-sulphonic acid; 8-amino-1-naphthol-3, 6-disulphonic acid; phloroglucinol; ascorbic acid; hypophosphorous acid; a titanous salt; a chromous salt; a stannous salt; sodium hydro sulphite; sodium stannite; hydroquinone; sodium hypochlorite; .cuprous chloride; an alkali metal iodide; potassium xanthate or benzoquinone.
Claim 13
Dependent Claim
50 words
A composition as claimed in any one of claims 6 to 10 wherein the lithographic desensitising material is dextrin; gum arabic; an alginate; a cellulose derivative; acrylamide homopolymer; or a polymer containing structural units derived from acrylamide and from 1 to 25% by weight of structural units containing carboxyl groups.
Claim 14
Dependent Claim
21 words
A composition as claimed in any one of claims 6 to 11 which additionally includes a surfactant and/or a dispersing agent.
Claim 15
Dependent Claim
41 words
The use of a composition comprising a compound capable of eliminating diazo groups for the purpose of improving the ink receptivity of a lithographic printing plate obtained by the exposure and development of a radiation sensitive coating containing a diazo compound.
Claim 16
Dependent Claim
41 words
The use of a composition comprising a compound capable of eliminating diazo groups for the purpose of improving the ink receptivity of a lithographic printing plate obtained by the exposure and development of a radiation sensitive coating containing a diazo compound.
References Cited (Backward Citations)
DE857739C
Cited
FR1419726A
Cited
US3373021A
Cited
FR1602009A
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FR2020081A1
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US3669660A
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FR2306832A1
Cited
FR2316636A1
Cited
DE2636119A1
Cited
FR2366598A1
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WO1979000593A1
Cited
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