Laser ablation imaging of zirconia-alumina composite ceramic printing member
First Claim
1. A method of imaging comprising the steps of:
- A) providing a lithographic printing member having a lithographic printing surface composed of a ceramic that is a composite of;
(1) a zirconia alloy, and (2) alumina, said composite ceramic having a density of from about 5.0 to about 6.05 g/cm3, and from about 0.1 to about 50%, by weight being comprised of alumina, andB) providing an image on said printing surface by imagewise exposing said printing surface to electromagnetic radiation provided by a laser under the following conditions;
an average power level of from about 0.1 to about 50 watts,a peak power of from about 6,000 to about 100,000 watts (in Q-switched mode),a pulse rate up to 50 kHz,an average pulse width of from about 50 to about 300 nsec, anda scan velocity of up to about 3 m/sec,so as to ablate the zirconia alloy in the exposed areas of said printing surface, and to transform said printing surface from a hydrophilic to an oleophilic state or from an oleophilic to a hydrophilic state in said exposed areas of said printing surface, thereby creating said lithographic printing surface having both image areas and non-image areas.
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Accused Products
Abstract
Reusable lithographic printing members are prepared from a ceramic that is a composite of a zirconia alloy and α-alumina. In use, a printing surface of the zirconia-alumina composite ceramic is imagewise exposed to electromagnetic radiation such as from a laser under controlled conditions to provide ablation of the zirconia alloy in the exposed areas. Those areas are transformed from a hydrophilic to an oleophilic state or from an oleophilic to a hydrophilic state, thereby creating a lithographic printing surface that is hydrophilic in non-image areas and is oleophilic and thus capable of accepting printing ink in image areas. Such inked areas can then be used to transfer an image to a suitable substrate in lithographic printing. The printing members are directly laser-imageable as well as image erasable, and can include printing plates, printing cylinders, printing tapes and printing sleeves.
60 Citations
19 Claims
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1. A method of imaging comprising the steps of:
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A) providing a lithographic printing member having a lithographic printing surface composed of a ceramic that is a composite of;
(1) a zirconia alloy, and (2) alumina, said composite ceramic having a density of from about 5.0 to about 6.05 g/cm3, and from about 0.1 to about 50%, by weight being comprised of alumina, andB) providing an image on said printing surface by imagewise exposing said printing surface to electromagnetic radiation provided by a laser under the following conditions; an average power level of from about 0.1 to about 50 watts, a peak power of from about 6,000 to about 100,000 watts (in Q-switched mode), a pulse rate up to 50 kHz, an average pulse width of from about 50 to about 300 nsec, and a scan velocity of up to about 3 m/sec, so as to ablate the zirconia alloy in the exposed areas of said printing surface, and to transform said printing surface from a hydrophilic to an oleophilic state or from an oleophilic to a hydrophilic state in said exposed areas of said printing surface, thereby creating said lithographic printing surface having both image areas and non-image areas. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A method of lithographic printing comprising the steps of:
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A) providing a lithographic printing member having a lithographic printing surface composed of a ceramic that is a composite of;
(1) a zirconia alloy, and (2) alumina, said composite ceramic having a density of from about 5.0 to about 5.5 g/cm3, and from about 0.1 to about 50%, by weight being comprised of alumina, andB) providing an image on said printing surface by imagewise exposing said printing surface to electromagnetic radiation provided by a laser under the following conditions; an average power level of from about 0.1 to about 50 watts, a peak power of from about 6,000 to about 100,000 watts, a pulse rate up to 50 kHz, an average pulse width of from about 50 to about 300 nsec, and a scan velocity of up to about 3 m/sec, so as to ablate the zirconia alloy in the exposed areas of said printing surface, and to transform said printing surface from a hydrophilic to an oleophilic state or from an oleophilic to a hydrophilic state in said exposed areas of said printing surface, thereby creating said 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 inked lithographic printing surface with a substrate to thereby transfer said printing ink to said substrate, forming an image thereon. - View Dependent Claims (17, 18, 19)
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Specification