Radiation-sensitive recording material for the production of driographic offset printing plates

• US 6,274,285 B1
• Filed: 11/12/1999
• Issued: 08/14/2001
• Est. Priority Date: 11/11/1998
• Status: Expired due to Fees

• Current Assignee: Agfa-Gevaert N.V.
• Original Assignee: Agfa-Gevaert N.V.
• Inventors: Gries, Willi-Kurt, Schlosser, Hans-Joachim
• Primary Examiner(s): CHU, JOHN S Y
• Application Number:
  US09/438,429
• Time in Patent Office: 641 Days
• Field of Search: 430/175, 430/176, 430/303, 430/162
• US Class Current: 430/162
• CPC Class Codes: G03F 7/0212 characterised by the polymeric binder or the macromolecular additives other than the diazo resins or the polymeric diazonium compounds
• CPC Class Codes: G03F 7/0215 Natural gums; Proteins, e.g. gelatins; Macromolecular carbohydrates, e.g. cellulose; Polyvinyl alcohol and derivatives thereof, e.g. polyvinylacetals
• CPC Class Codes: G03F 7/0752 in non photosensitive layers or as additives, e.g. for dry lithography

Abstract

A recording material is provided, having, in this sequence, a support, a radiation-sensitive layer and a silicone layer. The radiation-sensitive layer contains, as a radiation-sensitive component, a diazonium salt polycondensation product and, as a binder, a homopolymer of (C₁-C₁₂) alkyl vinyl ether units and/or a copolymer including at least 5 mol-% of such units, and being free of aliphatic hydroxyl groups. In a process to produce a printing plate for driographic offset printing, this recording material is exposed imagewise and subsequently developed using water or an aqueous solution.

Claims

1. A recording material comprising:

a support;

a radiation-sensitive layer and

a silicone layer;

wherein the radiation-sensitive layer contains;

a radiation-sensitive component comprising a diazonium salt polycondensation product; and

a binder comprising at least one of a homopolymer of (C₁-C₁₂) alkyl vinyl ether units and a copolymer which comprises at least 5 mol percent of such units, and is at least substantially free of aliphatic hydroxyl groups.

2. A recording material as claimed in claim 1, wherein the proportion of the radiation-sensitive component is from 20 to 80% by weight, based on the total weight of the non-volatile constituents of the radiation-sensitive layer.

3. A recording material as claimed in claim 2, wherein the proportion of the radiation-sensitive component is from 30 to 70% by weight, based on the total weight of the non-volatile constituents of the radiation-sensitive layer.

4. A recording material as claimed in claim 3, wherein the proportion of the radiation-sensitive component is from 40 to 65% by weight, based on the total weight of the non-volatile constituents of the radiation-sensitive layer.

5. A recording material as claimed in claim 1, wherein the binder comprises a homopolymer of methyl vinyl ether units or a copolymer containing methyl vinyl ether units.

6. A recording material as claimed in claim 1, wherein the copolymer further comprises units of maleic anhydride or monoalkyl maleates.

7. A recording material as claimed in claim 6, wherein the units of monoalkyl maleates comprise units of mono (C₁-C₆) alkyl maleates.

8. A recording material as claimed in claim 7, wherein the units of mono (C₁-C₆) alkyl maleates comprise units of monoethyl, monoisopropyl or monobutyl maleate.

9. A recording material as claimed in claim 1, wherein the homopolymer or copolymer used as a binder in the radiation-sensitive layer has a molecular weight, M_W, in the range from 40,000 to 2,000,000.

10. A recording material as claimed in claim 9, wherein the homopolymer or copolymer used as a binder in the radiation-sensitive layer has a molecular weight, M_W, in the range from 50,000 to 1,000,000.

11. A recording material as claimed in claim 10, wherein the homopolymer or copolymer used as a binder in the radiation-sensitive layer has a molecular weight, M_W, in the range from 80,000 to 500,000.

12. A recording material as claimed in claim 1, wherein the proportion of the binder is from 5 to 40% by weight, based on the total weight of the non-volatile constituents of the radiation-sensitive layer.

13. A recording material as claimed in claim 1, wherein the diazonium salt polycondensation product is obtained by condensation of a polycyclic aromatic diazonium compound with an active carbonyl compound.

14. A recording material as claimed in claim 13, wherein the polycyclic aromatic diazonium compound comprises a substituted or unsubstituted diphenylamine-4-diazonium salt and the active carbonyl compound comprises methoxymethyldiphenyl ether or formaldehyde.

15. A recording material as claimed in claim 1, wherein the radiation-sensitive layer additionally contains dyes or plasticizers.

16. A recording material as claimed in claim 15, wherein the radiation-sensitive layer contains glycerol.

17. A recording material as claimed in claim 1, wherein the weight of the radiation-sensitive layer is from about 0.5 to 3.0 g/m².

18. A recording material as claimed in claim 17, wherein the weight of the radiation-sensitive layer is from 0.8 to 1.5 g/m².

19. A recording material as claimed in claim 1, wherein the silicone layer includes a condensation silicone rubber.

20. A recording material as claimed claim 1, wherein the weight of the silicone layer is from 1.0 to 5.0 g/m².

21. A recording material as claimed claim 20, wherein the weight of the silicone layer is from 1.2 to 3.5 g/m².

22. A recording material as claimed claim 21, wherein the weight of the silicone layer is from 1.5 to 3.0 g/m².

23. A recording material as claimed in claim 1, wherein a discontinuous matting layer is present on the silicone layer.

24. A recording material as claimed in claim 23, wherein the matting layer comprises a water-soluble organic polymer.

25. A recording material as claimed in claim 24, wherein the water-soluble organic polymer comprises polyvinylpyrrolidone, polyacrylic acid, polyvinylbutyral, polysaccharides, gelatin or polyvinyl alcohol.

26. A recording material as claimed in claim 1, wherein the support comprises an electrochemically roughened aluminum or an aluminum alloy.

27. A recording material as claimed in claim 1, wherein the radiation-sensitive layer is applied directly to the support.

28. A recording material as claimed in claim 1, wherein said copolymer is free of aliphatic hydroxyl groups.

29. A process for producing a printing plate for driographic offset printing, wherein the recording material as claimed in claim 1 is exposed imagewise and subsequently developed using water or an aqueous solution.