Process of manufacturing light-sensitive copying material based on diazonium salt condensation products
AssigneeHoechst Aktiengesellschaft
InventorsGerhard Sprintschnik, Fritz Uhlig
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Abstract
This invention relates to a light-sensitive copying material comprising a coating support and an optically homogeneous light-hardenable coating which contains a condensation product of an aromatic diazonium salt and a water-insoluble macromolecular polymer, wherein the coating is applied from a stable dispersion of the water-insoluble polymer under conditions such that after drying an optically homogeneous coating is formed. The invention also relates to a process for the manufacture of a light-sensitive copying material containing the optically homogeneous light-hardenable coating.
Claims6
In a process for the manufacture of a negative-working, presensitized planographic printing plate developable in pure water at room temperature by applying an aqueous coating mixture without any addition of organic solvent to an aluminum plate support and drying the coating, said coating mixture containing
- (a) a water-soluble light-sensitive condensation product of an aromatic diazonium salt,
- (b) a stable dispersion of a water-insoluble macromolecular polymer, and
- (c) about 0.01 to 0.6 part by weight of a surface-active agent per part by weight of the water-insoluble polymer, over and above the amount of surface-active agent required to manufacture and stabilize the dispersion,
- the improvement which comprises drying the coating mixture at a temperature between about 45.degree. C. and the decomposition temperature of the diazonium compound and under conditions such that an optically homogeneous light-hardenable coating with no discrete particles visible at 30,000-fold magnification is formed.
Dependencies are inferred from the claim text.