Eastman Kodak Company
Lithographic printing plate precursors and method of use

Abstract:

Lithographic printing plate precursors are prepared with a unique substrate and one or more radiation-sensitive imageable layers. The substrate is prepared by two separate anodizing processes to provide an inner aluminum oxide layer having an average dry thickness (T.sub.i) of 650-3,000 nm and a multiplicity of inner micropores having an average inner micropore diameter (D.sub.i) of .ltoreq.15 nm. A formed outer aluminum oxide layer comprises a multiplicity of outer micropores having an average outer micropore diameter (D.sub.o) of 15-30 nm; an average 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, and D.sub.o in nanometers and the outer aluminum oxide layer micropore density (C.sub.o) in micropores/.mu.m.sup.2, are further defined by the outer aluminum oxide layer porosity (P.sub.o) according to the following equation: 0.3.ltoreq.P.sub.o.ltoreq.0.8 where P.sub.o is 3.14(C.sub.o)(D.sub.o.sup.2)/4,000,000.