Zirconia alloy cylinders and sleeves for imaging and lithographic printing methods

A rotary lithographic printing member having an imaged printing surface adapted for use in lithographic printing, said imaged printing surface comprising a non-porous zirconia ceramic having thereon an imagewise distribution of hydrophilic areas and oleophilic areas, said non-porous zirconia ceramic being an alloy of ZrO.sub.2 and a secondary oxide selected from the group consisting of MgO, CaO, Y.sub.2 O.sub.3, Sc.sub.2 O.sub.3, a rare earth oxide, and a combination of any of these, said zirconia alloy ceramic having a density of from about 5.6 to about 6.2 g/cm.sup.3,

• said rotary lithographic printing member having one of the following forms:
• a) a printing cylinder composed entirely of said zirconia alloy ceramic,
• b) a non-ceramic core, and a hollow cylindrical sleeve or shell fitted around said core, said sleeve or shell providing said printing surface that is composed of said zirconia alloy ceramic,
• c) a hollow cylindrical sleeve composed entirely of said zirconia alloy ceramic, or
• d) a hollow cylindrical sleeve composed of an outer printing layer of said zirconia alloy ceramic.

A method of imaging comprising the steps of:

• A) providing a rotary lithographic printing member that can be imaged directly using a laser and is image erasable, said printing member having a printing surface composed of a non-porous zirconia ceramic that is an alloy of ZrO.sub.2 and a secondary oxide selected from the group consisting of MgO, CaO, Y.sub.2 O.sub.3, Sc.sub.2 O.sub.3, a rare earth oxide, and a combination of any of these, said zirconia alloy ceramic having a density of from about 5.6 to about 6.2 g/cm.sup.3, and
• B) providing an image on said printing member by imagewise exposing said printing surface to laser irradiation that transforms said printing surface from a hydrophilic to an oleophilic state, or from an oleophilic to a hydrophilic state, creating a lithographic printing surface having both image areas and non-image areas,
• said rotary lithographic printing member having one of the following forms:
• a) a printing cylinder composed entirely of said zirconia alloy ceramic,
• b) a non-ceramic core, and a hollow cylindrical sleeve or shell fitted around said core, said sleeve or shell providing said printing surface that is composed of said zirconia alloy ceramic,
• c) a hollow cylindrical sleeve composed entirely of said zirconia alloy ceramic, or
• d) a hollow cylindrical sleeve composed of an outer printing layer of said zirconia alloy ceramic.

A method of printing comprises the steps of:

• A) providing a rotary lithographic printing member that can be imaged directly using a laser and is image erasable, said printing member having a printing surface composed of a non-porous zirconia ceramic that is an alloy of ZrO2 and a secondary oxide selected from the group consisting of MgO, CaO, Y.sub.2 O.sub.3, Sc.sub.2 O.sub.3, a rare earth oxide, and a combination of any of these, said zirconia alloy ceramic having a density of from about 5.6 to about 6.2 g/cm.sup.3,
• B) providing an image on said printing member by imagewise exposing said printing surface to laser irradiation that transforms said printing surface from a hydrophilic to an oleophilic state, or from an oleophilic to a hydrophilic state, thereby creating a lithographic printing surface having both image areas and non-image areas,
• C) contacting said lithographic printing surface with an aqueous fountain solution and a lithographic printing ink, thereby forming an inked lithographic printing surface, and
• D) contacting said lithographic printing surface with a substrate to thereby transfer said printing ink to said substrate, forming an image thereon, said rotary lithographic printing member having one of the following forms:
• a) a printing cylinder composed entirely of said zirconia alloy ceramic,
• b) a non-ceramic core, and a hollow cylindrical sleeve or shell fitted around said core, said sleeve or shell providing said printing surface that is composed of said zirconia alloy ceramic,
• c) a hollow cylindrical sleeve composed entirely of said zirconia alloy ceramic, or
• d) a hollow cylindrical sleeve composed of an outer printing layer of said zirconia alloy ceramic.