Process for the post-treatment of developed relief printing forms for use in flexographic printing
AssigneeHoechst Aktiengesellschaft
InventorHeinz Herrmann
Life of this patent
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Abstract
The invention describes a process for the post-treatment of developed relief printing forms for use in flexographic printing. The relief printing forms are reexposed in a customary manner and thereafter treated according to the invention, using a solution which comprises an organic solvent and, dissolved therein, an aryl- or hetaryl-bis(trihalogenomethyl)-s-triazine; they are then dried and briefly reexposed to UV light. The process of the invention eliminates the tackiness of the surfaces of light-hardened flexographic printing forms comprising a photopolymer and it also considerably enhances the resistance of these printing forms to air containing ozone.
Claims22
A process for the post-treatment of developed relief printing forms, which have been reexposed in a customary manner, for use in flexographic printing, comprising the steps of:
- treating the relief printing forms with a solution comprising:
- (a) an organic solvent and
- (b) at least one aryl- or hetaryl-bis(trihalogenomethyl)-s-triazine compound of the general formula I ##STR4## in which A denotes a conjugated alkylene chain,
- R denotes a substituted or unsubstituted aromatic or heterocyclic aromatic radical,
- Hal denotes a chlorine, bromine or iodine atom, and
- n is 0 or 1;
- wherein the concentration of said aryl- or hetaryl-bis(trihalogenomethyl)-s-triazine in said solution is between 0.1% by weight and the saturation value of said compound in said solvent;
- drying the relief printing forms;
- and
- briefly reexposing the relief printing forms to UV light.
Dependencies are inferred from the claim text.