Back to results
US 8,940,474 B2Granted
Method of providing lithographic printing plates
AssigneeEastman Kodak Company
InventorsMoshe Levanon, Leonid Askadsky
Life of this patent
Estimating the term…
Abstract
A silicate-free alkaline aqueous developer composition has a pH of at least 12 and comprises a hydroxide alkali agent, a metal cation M2+ selected from barium, calcium, strontium, and zinc cations, a chelating agent for the metal cation, and an alkali metal salt that is different than the other components. These developer compositions can be used to process imaged positive-working lithographic printing plate precursors to prepare lithographic printing plates.
Claims19
A method for providing a lithographic printing plate comprising:
- A) imagewise exposing a positive-working lithographic printing plate precursor having an imageable layer to provide exposed and non-exposed regions using infrared radiation,
- wherein the imageable layer comprises an infrared radiation absorbing compound and a primary polymeric binder in an amount of at least 40 weight % and up to and including 95 weight %, based on the total dry weight of the imageable layer, the primary polymeric binder comprising recurring units represented by either or both of the following Structures (Ia) and (Ib), in random order:
- wherein:
- when both Structure (Ia) and (Ib) recurring units are present, the Structure (Ia) recurring units are present in an amount of at least 10 and up to and including 35 mol %, and the Structure (Ib) recurring units are present in an amount of at least 25 and up to and including 60 mol %, all based on total recurring units in the polymeric binder,
- R is a substituted or unsubstituted hydroxyaryl group, and
- R2 is a substituted or unsubstituted hydroxyaryl group in which the hydroxyl group is ortho to the ester linkage, and
- B) processing the exposed lithographic printing plate precursor with a developer composition to remove the exposed regions in the imageable layer,
- wherein the developer composition is a silicate-free and sugar-free alkaline aqueous developer composition having a pH of at least 12 and comprising:
- (a) a hydroxide,
- (b) a metal cation M2+ selected from barium, calcium, strontium, and zinc cations,
- (c) a chelating agent for the metal cation M2+, and
- (d) an alkali metal salt different than all of a, b, and c above.
9 more elements
Dependencies are inferred from the claim text.