Lithographic printing plate precursors, methods of using and manufacture

A method for preparing a lithographic printing plate precursor, comprising, in order:

• A) providing an aluminum-containing plate having an electrochemically or mechanically grained and etched surface;
• B) subjecting the aluminum-containing plate to a first anodizing process to form an outer aluminum oxide layer on the electrochemically or mechanically grained and etched surface, t e out m oxide layer comprising a multiplicity of outer micropores having an average outer micropore diameter (Do) of at least 12 nm and up to and including 50 nm, and having an average dry thickness (To) of at least 20 nm and up to and including 650 nm;
• C) rinsing the outer aluminum oxide layer;
• D) subjecting the aluminum-containing plate to an additional anodizing process, using sulfuric acid, to form an inner aluminum oxide layer underneath the outer aluminum oxide layer, the inner aluminum oxide layer having an average dry thickness (Ti) of at least 300 mm and up to and including 3000 nm, and comprising a multiplicity of inner micropores having an average inner micropore diameter (Di) of less than or equal to 11 nm, wherein the inner aluminum oxide layer comprises aluminum sulfate;
• E) rinsing the outer aluminum oxide layer and the inner aluminum oxide layer;
• F) providing a hydrophilic layer over the outer aluminum oxide layer, wherein the hydrophilic layer comprises:
• (1) one or more phosphorus-containing compounds having a C1 dry coverage and represented by the following Formula (I):
• wherein n is zero or an integer from 1 to 10, —OM represents —OH or —O−M+, and M+ is a monovalent cation;
• and optionally (2) one or more hydrophilic polymers having a C2 dry coverage when present,
• wherein the C1 dry coverage of the (1) one or more phosphorus-containing compounds is at least 50 mg/m2 and up to and including 300 mg/m2, and the ratio of the C1 dry coverage to the C2 dry coverage, when the (2) one or more hydrophilic polymers are present, is at least 11:9;
• and
• G) forming an on-press developable, negative-working infrared radiation-sensitive imageable layer over the outer aluminum oxide layer,
• wherein the on-press developable, negative-working infrared radiation sensitive imageable layer comprising the following components (a) through (c) and optionally component (d):
• (a) one or more free radically polymerizable components;
• (b) an initiator composition that provides free radicals upon exposure of the on-press developable, negative-working infrared radiation-sensitive imageable layer to imaging infrared radiation;
• (c) one or more infrared radiation absorbers that comprise an anionic chromophore having a net negative charge or an acidic group;
• and optionally
• (d) one or more polymeric binders, all of which are different from all of components (a), (b), and (c).