Patent ID: 11964466
Assignee: EASTMAN KODAK COMPANY
Field: Textile and paper machines (Mechanical engineering)
Classification: CPC B  C  G | IPC B  G

Claim 16:
17. A method for preparing a lithographic printing plate precursor, comprising, in order:
providing an aluminum-containing plate having an electrochemically or mechanically grained and etched planar surface;
subjecting the aluminum-containing plate to a first anodizing process to form an outer aluminum oxide layer on the etectrochemically or mechanically grained and etched planar surface, the outer aluminum oxide layer comprising a multiplicity of outer micropores having an average outer micropore diameter (Do) of at least 15 nm and up to and including 30 nm, and having an average dry thickness (To) of at least 130 nm and up to and including 650 nm;

rinsing the outer aluminum oxide layer;
subjecting the aluminum-containing plate to a second anodizing process 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 650 nm and up to and including 3,000 nm; and comprising a multiplicity of inner micropores having an average inner micropore diameter (Di) of less than 15 nm;
rinsing the outer aluminum oxide layer and the inner aluminum oxide layer;
forming an on-press developable radiation-sensitive imageable layer on the outer aluminum oxide layer; and
after rinsing the outer aluminum oxide layer and the inner aluminum oxide layer and before forming the on-press developable radiation-sensitive imageable layer on the outer aluminum oxide layer, providing a hydrophilic layer on the outer aluminum oxide layer, the hydrophilic layer comprising one or more hydrophilic polymers at least one of which hydrophilic polymers is a hydrophilic copolymer that comprises at least (a) recurring units comprising an amide unit, and (b) recurring units comprising an —OM group that is directly connected to a phosphorus atom, wherein M represents a hydrogen, sodium, potassium, or aluminum atom, and which hydrophilic layer is disposed on the outer aluminum oxide layer at a dry coverage of at least 0.0002 g/m2 and up to and including 0.1 g/m2.