Eastman Kodak Company
LITHOGRAPHIC PRINTING PLATE PRECURSORS AND METHOD OF USE

Abstract:

Lithographic printing plate precursors are prepared with a unique substrate using two separate anodizing processes to provide an inner aluminum oxide layer of average dry thickness (T.sub.i) of 650-3,000 nm and a multiplicity of inner micropores of average inner micropore diameter (D.sub.i) of .ltoreq.15 nm. An outer aluminum oxide layer comprises a multiplicity of outer micropores of average outer micropore diameter (D.sub.o) of 15-30 nm; dry thickness (T.sub.o) of 130-650 nm; and a micropore density (C.sub.o) of 500-3,000 micropores/.mu.m.sup.2. The ratio of D.sub.o to D.sub.i is greater than 1.1:1. A hydrophilic layer disposed on the outer aluminum oxide layer has a copolymer composed of (a) recurring units and (b) recurring units, wherein the (a) recurring units have an amide group, and the (b) recurring units have at least a phosphonic acid, a phosphoric acid, a salt of a phosphonic acid, or a salt of a phosphoric acid group.