US Patent 7153408 Copper electroplating of printing cylinders

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.