Claims
- 1. 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,
- 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.
- 2. The printing member of claim 1 comprised of said zirconia alloy ceramic in which the molar ratio of said secondary oxide to said zirconium oxide is from about 0.5:99.5 to about 25:75.
- 3. The printing member of claim 1 wherein said zirconia alloy ceramic is a zirconia-yttria ceramic.
- 4. The printing member of claim 3 wherein the molar ratio of the secondary oxide to zirconia is from about 0.5:99.5 to about 5.0:95.0.
- 5. The printing member of claim 1 wherein said zirconia alloy ceramic comprises the tetragonal crystalline form of zirconia.
- 6. The printing member of claim 1 wherein said zirconia alloy ceramic comprises a mixture of any two or more of the tetragonal, monoclinic and cubic crystalline forms of zirconia.
- 7. The printing member of claim 1 wherein said zirconia alloy ceramic is composed of a hydrophilic stoichiometric zirconia.
- 8. The printing member of claim 1 wherein said zirconia alloy ceramic is composed of an oleophilic substoichiometric zirconia.
- 9. The printing member of claim 1 wherein said zirconia alloy ceramic has an average grain size of from 0.1 to 0.6 .mu.m.
- 10. The printing member of claim 1 wherein said zirconia alloy ceramic has a density of 6.03 to 6.06 grams/cm.sup.3 and an average grain size of from 0.2 to 0.5 .mu.m.
- 11. The printing member of claim 1 having a polished zirconia alloy ceramic printing surface.
- 12. The printing member of claim 1 wherein said non-ceramic core is composed of a ferrous metal, nickel, brass, copper, aluminum or magnesium.
- 13. The printing member of claim 1 having a porosity of less than 0.1%.
- 14. 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.
- 15. 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.
- 16. 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.
- 17. The method of claim 16 further comprising cleaning said inked lithographic printing surface, and erasing said image thereon.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a CIP of U.S. Ser. No. 08/576,178, filed Dec. 21, 1995, now U.S. Pat. No. 5,743,188 which is based on provisional application 60/005729, filed Oct. 20, 1995.
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Continuation in Parts (1)
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Number |
Date |
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Parent |
576178 |
Dec 1995 |
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