Recording material having a negative-working, radiation-sensitive layer which comprises additives for promoting developability

1. A recording material which comprises a support and a negative-working, radiation-sensitive layer which comprises a diazonium salt and a polymeric binder, the radiation-sensitive layer comprises a sulphobetaine, wherein the sulphobetaine is of the formula I:

in which

R 1 to R 3 are identical or different and are substituted or unsubstituted and/or mono- or polyunsaturated, acyclic or isocyclic hydrocarbon radicals having from 1 to 16 carbon atoms, in which one or more methylene groups is optionally replaced by

—O—, —S—, —NH—, —CO—NH— and/or —O—CO—NH—groups, and, in the case of the acyclic radicals, each two thereof is optionally linked to one another to form a saturated or unsaturated ring, and

R 4 is a substituted or unsubstituted (C 1 -C 6 )alkanediyl group.

2. The recording material according to claim 1 , wherein the radiation-sensitive layer in addition comprises a combination of a polymerizable monomer or oligomer and a photopolymerization initiator.

3. The recording material according to claim 1 , wherein at least one of the radicals R 1 to R 3 is a methyl radical.

4. The recording material according to claim 1 , wherein two of the radicals R 1 to R 3 are linked to one another with formation of a five- to seven-membered ring.

5. The recording material according to claim 1 , wherein the radical R 4 is a substituted or unsubstituted ethane-1,2-diyl, propane-1,3-diyl or butane-1,4-diyl radical.

6. The recording material according to claim 1 , wherein the proportion of the sulphobetaines is from 1 to 15% by weight, based on the total weight of the non-volatile constituents of the radiation-sensitive layer.

7. The recording material according to claim 1 , wherein the radiation-sensitive layer has been coloured using dyes and/or pigments.

8. The recording material according to claim 1 , wherein the diazonium salt is a condensation product of an aromatic diazonium salt.

9. The recording material according to claim 1 , wherein the weight of the radiation-sensitive layer when dried is from 0.3 to 3.0 g/m 2 .

10. The recording material according to claim 1 , wherein the material is pigmented or matted.

11. The recording material according to claim 1 , wherein the support is a plate, a film, a foil or a band of metal, plastic or a plastic/metal laminate.

12. The recording material according to claim 11 , wherein the support is an aluminium or an aluminium alloy, and at least one side of the support has been mechanically, chemically and/or electrochemically roughened, and optionally anodically oxidized and/or chemically aftertreated.

13. The recording material according to claim 1 , wherein the support has been provided with a back coating of polymeric materials.

14. A process for the production of a printing plate for offset printing, which comprises exposing imagewise the recording material according to claim 1 , and subsequently developing using an aqueous-alkaline developer.

15. The recording material according to claim 4 , wherein two of the radicals R 1 to R 4 are linked to one another to form a morpholinium ring or a pyridinium ring.

16. The recording material according to claim 5 , wherein the proportion of the sulphobetaine is from 2 to 10% by weight based on the total weight of the non-volatile constituents of the radiation-sensitive layer.

17. The recording material according to claim 16 , wherein the weight of the radiation-sensitive layer when dried is from 0.5 to 2.0 g/m 2 .

18. The recording material according to claim 16 , wherein the weight of the radiation-sensitive layer when dried is from 0.6 to 1.6 g/m 2 .

19. A recording material which comprises support and a negative-working, radiation-sensitive layer which comprises a diazonium salt and a polymeric binder, the radiation-sensitive layer comprises a sulphobetaine as surfactant.