Copper electroplating of printing cylinders and copper deposition method

Abstract

The present invention is directed to an improved copper plating bath for depositing a copper layer onto a printing cylinder, the copper plating bath comprising: (a) a source, of copper ions; (b) a source of methane sulphonate ions; (c) a source of chloride ions; (d)an organosulphur compound having the formula R-S-R' -SO3'X<+> or X<+>-O3S-R'S-R-S-R' -SO3- X<+>, wherein R is alkyl, hydroxyalkyl or alkyl ether, R' is a C2-C4 alkyl group, and X<+> is a cation; and (e) a polyether compound and method of using the same. The copper plating bath produces a plating deposit that has a stable hardness and is free from self-annealing during high speed plating.

Description

technical field The present invention relates to an improved method for depositing copper layers to provide copper layers with stable hardness. Background technique Gravure printing is a method of using the intaglio printing process on an engraved copper-coated cylinder, where the image to be printed consists of depressions, usually etched or engraved to varying depths. Slightly viscous solvent ink was applied to the entire surface and excess ink was removed from the non-printing surface with a metal squeegee. In a typical process, engraving is performed on a copper-plated cylinder, which is then chrome-plated to reduce wear. In order to obtain consistent quality engravings, the hardness and crystal structure of the copper deposit are extremely important. Successful engraving is usually only achieved with copper hardness greater than 200 Vickers (HV). At lower values, engraved well pattern loses precision. In addition, if the hardness of the deposit exceeds 240HV, the l...

AI Technical Summary

Problems solved by technology

However, plating from methanesulfonate electrolytes offers many advantages in terms of plating speed and resistance to anodic polarization, however, the problem of self-annealing of deposits remains

Furthermore, the additive combination disclosed in U.S. Patent No. 5,417,841 to Frisby does not prevent self-annealing of deposits in mesylate baths, so additional improvements are still needed

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