Method for obtaining a lithographic printing surface using a metal complex

• US 20030017417A1
• Filed: 07/23/2001
• Published: 01/23/2003
• Est. Priority Date: 07/23/2001
• Status: Abandoned Application

• Current Assignee: Creo Incorporated (Eastman Kodak Company)
• Original Assignee: Creo Incorporated (Eastman Kodak Company)
• Inventors: Yu, Yisong, Emans, John, Goodin, Jonathan William, Rademacher, Katja
• Application Number:
  US09/909,791
• Publication Number:
  US 20030017417A1
• Time in Patent Office: Days
• US Class Current: 430/302
• CPC Class Codes: B41C 1/1025 using materials comprising a polymeric matrix containing a polymeric particulate material, e.g. hydrophobic heat coalescing particles
• CPC Class Codes: B41C 2210/04 Negative working, i.e. the non-exposed (non-imaged) areas are removed
• CPC Class Codes: B41C 2210/08 Developable by water or the fountain solution
• CPC Class Codes: B41C 2210/22 characterised by organic non-macromolecular additives, e.g. dyes, UV-absorbers, plasticisers
• CPC Class Codes: B41C 2210/24 characterised by a macromolecular compound or binder obtained by reactions involving carbon-to-carbon unsaturated bonds, e.g. acrylics, vinyl polymers
• CPC Class Codes: B41C 2210/264 Polyesters; Polycarbonates
• CPC Class Codes: B41C 2210/266 Polyurethanes; Polyureas

Abstract

In accordance with the present invention there is provided an imaging element for lithographic offset printing. The imaging element comprises hydrophobic polymer particles in an aqueous medium, a substance for converting light into heat, and a metal complex. The imaging element may be used for printing long run lengths on lower quality paper and in the presence of set-off powder. The imaging element may be imaged and developed on-press and may be sprayed onto a hydrophilic surface to create a printing surface that may be processed wholly on-press. The hydrophilic surface may be a printing plate substrate, the printing cylinder of a printing press, or a seamless sleeve around the printing cylinder of a printing press. This cylinder may be conventional or seamless.

Claims

1. ) a method for obtaining a lithographic printing surface comprising the steps of:

a) image-wise or information-wise exposing to radiation a thermally convertible lithographic printing precursor comprising

i) a hydrophilic lithographic base,

ii) a radiation sensitive coating on at least one surface of said hydrophilic lithographic base, said coating comprising within at least one layer

(1) uncoalesced particles of at least one hydrophobic thermoplastic polymer and

(2) at least one metal complex and

(3) at least one converter substance capable of converting radiation into heat

b) developing said exposed thermally convertible lithographic printing precursor with an aqueous medium in order to remove the unexposed parts of said coating.

2. ) A method for obtaining a lithographic printing surface as in claim 1, wherein said radiation is light.

3. ) A method for obtaining a lithographic printing surface as in claim 2, wherein said light is infrared.

4. ) A method for obtaining a lithographic printing surface as in claim 3, wherein said at least one hydrophobic thermoplastic polymer is a member of at least one of the following groups of polymers and their associated copolymers:

polystyrene, polymers of substituted polystyrene, polyethylene, poly(meth)acrylates, polyvinylchloride, polyurethanes, polyesters, polyacrylonitrile.

5. ) A method for obtaining a lithographic printing surface as in claim 1, wherein said converter substance comprises at least one of carbon black, a pigment, and a dye.

6. ) A method for obtaining a lithographic printing surface as in claim 5, wherein said dye comprises an infrared absorbing dye.

7. ) A method for obtaining a lithographic printing surface as in claim 1, wherein said metal complex is at least one of an aqueous-soluble metal complex and a water-miscible metal complex.

8. ) A method for obtaining a lithographic printing surface as in any of the above claims, wherein said hydrophilic lithographic base is one of a metallized plastic sheet, a treated aluminum plate, a sleeve-less printing press cylinder, a printing press cylinder sleeve, and a flexible support having thereon a cross-linked hydrophilic layer.

9. ) A method for obtaining a lithographic printing surface as in claim 8, wherein said sleeve-less printing press cylinder and said printing press cylinder sleeve are seamless.

10. ) A method for obtaining a lithographic printing surface as in claim 8, wherein the surface of said lithographic base is anodized aluminum.

11. ) A method for obtaining a lithographic printing surface as in claim 8, wherein at least one laser is used for said image-wise or information-wise exposing.

12. ) A method for obtaining a lithographic printing surface as in claim 8, wherein said image-wise or information-wise exposing is performed while said thermally convertible lithographic printing precursor is mounted on a printing press, said mounting being one of fixed and removable.

13. ) A method for obtaining a lithographic printing surface as in claim 8, wherein said radiation sensitive coating is applied to said hydrophilic lithographic base while said hydrophilic lithographic base is mounted on a printing press, said mounting being one of fixed and removable.

14. ) A method for obtaining a lithographic printing surface as in claim 8, wherein said developing of an image-wise or information-wise exposed thermally convertible lithographic printing precursor is performed while said precursor is mounted on a printing press, said mounting being one of fixed and removable.

15. ) A method for obtaining a lithographic printing surface as in claim 1, wherein said at least one converter substance is present in the same layer as said uncoalesced particles of at least one hydrophobic thermoplastic polymer.

16. ) A method for obtaining a lithographic printing surface as in claim 8, wherein said metal complex is at least one of

a) a metal acetylacetonate and

b) a metal phthalocyaninetetrasulphonic acid, tetra sodium salt.

17. ) A method for obtaining a lithographic printing surface as in claim 8, wherein said coating further comprises a metal salt.