EP0051081A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Lithographic developing process and apparatus
Assignee: Individual
•
Filing: 1980-11-03
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Granted: —
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Expires: 2000-11-03
Abstract
Abstract Process for developing a lithographic printing plate having a hydrophilic, anionic, negatively charged surface and a layer of a light sensitive, cationic material which has been selectively exposed to actinic light in an image area. The plate is contacted after exposure with an aqueous developing solution of an anionic material. The anionic material is capable of ionically coupling with unexposed light sensitive material and of dissolving the coupled product.
Inventors
- 👤 Howard A. Fromson
- 👤 Robert F. Gracia
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 13:14
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/26; G03F7/30; G03F7/32
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
103 words
Process for developing a lithographic printing plate comprising a substrate having a hydrophilic, anionic, negatively charged surface and a layer on said surface of a light sensitive, cationic material which has been selectively exposed to actinic light in an image area which comprises contacting the plate after exposure with a developer consisting essentially of an queous solution of an anionic material, said anionic material being capable of ionically coupling with unexposed light sensitive material and of dissolving the coupled product, said aqueous solution having a concentration of anionic material which is sufficient to couple with said unexposed material and dissolve the coupled product.
Claim 2
Dependent Claim
103 words
Process for developing a lithographic printing plate comprising a substrate having a hydrophilic, anionic, negatively charged surface and a layer on said surface of a light sensitive, cationic material which has been selectively exposed to actinic light in an image area which comprises contacting the plate after exposure with a developer consisting essentially of an queous solution of an anionic material, said anionic material being capable of ionically coupling with unexposed light sensitive material and of dissolving the coupled product, said aqueous solution having a concentration of anionic material which is sufficient to couple with said unexposed material and dissolve the coupled product.
Claim 3
Dependent Claim
14 words
Process of claim 1 wherein the plate after exposure is immersed in the developer.
Claim 4
Dependent Claim
13 words
Process of claim 1 wherein the light sensitive material is a diazonium material.
Claim 5
Dependent Claim
17 words
Process of claim 1 wherein the developer is at a temperature of from 18 to 90° C.
Claim 6
Dependent Claim
37 words
Process of claim 1 wherein the anionic surfactant is selected from the group of alkali metal salts of alkylaryl sulfonates, alkali metal salts of alkyl sulfonates and alkali metal and ammonium salts of sulfated higher fatty alcohols.
Claim 7
Dependent Claim
118 words
Apparatus for developing a lithographic printing plate comprising a substrate having a hydrophilic, anionic negatively charged surface and a layer on said surface of a light sensitive cationic material which has been selectively exposed to actinic light in an image area which comprises ( I ) means for contacting the plate after exposure with a developer consisting essentially of an aqueous solution of an anionic material said anionic material being capable of ionically coupling with unexposed light sensitive material and of dissolving the coupled product, said aqueous solution having a concentration of anionic material which is sufficient to couple with said unexposed material and dissolve the coupled product. (II) means following the contacting means for rinsing the plate.
Claim 8
Dependent Claim
118 words
Apparatus for developing a lithographic printing plate comprising a substrate having a hydrophilic, anionic negatively charged surface and a layer on said surface of a light sensitive cationic material which has been selectively exposed to actinic light in an image area which comprises ( I ) means for contacting the plate after exposure with a developer consisting essentially of an aqueous solution of an anionic material said anionic material being capable of ionically coupling with unexposed light sensitive material and of dissolving the coupled product, said aqueous solution having a concentration of anionic material which is sufficient to couple with said unexposed material and dissolve the coupled product. (II) means following the contacting means for rinsing the plate.
Claim 9
Dependent Claim
20 words
Apparatus of claim 6 wherein the means for contacting includes means for immersing and/or spraying the plate with the developer.
References Cited (Backward Citations)
US3891439A
Cited
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