Lithographic printing members for use with laser-discharge imaging
AssigneePresstek, Inc.
InventorsMichael T. Nowak, Thomas E. Lewis
Life of this patent
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Abstract
Lithographic printing plates suitable for imaging by means of laser devices that emit in the near-infrared region. Laser output either ablates one or more plate layers or physically transforms a surface layer, in either case resulting in an imagewise pattern of features on the plate. The image features exhibit an affinity for ink or an ink-abhesive fluid that differs from that of unexposed areas.
Claims24
A lithographic printing member directly imageable by laser discharge, the member comprising:
- a. a topmost first layer which is polymeric;
- and
- b. a thin metal layer underlying the first layer;
- and
- c. a substrate underlying the metal layer;
- wherein
- d. the metal layer is formed of a material which is subject to ablative absorption of imaging infrared radiation and the first layer is not;
- and
- e. the first layer exhibits an affinity for an abhesive fluid for ink and the substrate [exhibit different affinities for at least one printing liquid selected from the group consisting of ink and an abhesive fluid for ink] exhibits an affinity for ink .
The member of claim [1] 22 wherein the first layer is oleophobic.
[8. The member of claim 7 wherein the first layer is a
- silicone chemical species.]9. The member of claim [8] 22 wherein the silicone is anchored to the metal layer by means of a silane adhesion promoter.
[10. The member of claim 1 wherein the first
- layer is hydrophobic.]11. The member of claim [10] 1 wherein the first layer is a polyvinyl alcohol chemical species.
- 2. The member of claim 11 wherein the polyvinyl alcohol is anchored to
- the metal layer by means of a titanate adhesion promoter. 13. The member of claim 1 wherein the first layer is anchored to the metal layer by means
- of an adhesion promoter. 14. The member of claim 1 wherein the substrate comprises first and second surfaces, at least one of which has means to
- improve adhesion. 15. The member of claim 1 wherein the substrate comprises first and second surfaces, at least one of which has means to
- reduce static buildup. 16. The member of claim 1 wherein the substrate comprises first and second surfaces, the first has means to improve
- adhesion and the second surface has means to reduce static buildup. 17. The member of claim 1 further comprising an antireflective layer
- between the metal and first layers. 18. The member of claim 1 wherein the
- substrate is laminated to a metal support.
A lithographic printing member directly imageable by laser discharge, the member comprising:
- a. a topmost first layer which is formed of an addition-cured silicone;
- b. a thin metal layer underlying the first layer and formed of titanium or an alloy thereof;
- and
- c. a substrate underlying the metal layer;
- wherein
- d. the metal layer is subject to ablative absorption of imaging infrared radiation and the first layer is not;
- and
- e. the first layer and the substrate exhibit different affinities for at least one printing liquid selected from the group consisting of ink and an abhesive fluid for ink.
Dependencies are inferred from the claim text.