Electroplating zinc or cadmium and additive composition therefor
AssigneeW. Canning & Company Limited
InventorsBarrie Sidney James, Apolonious Wyszynski
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Abstract
Zinc and cadmium are electrodeposited in the presence of the more or less complex mixture present after reacting (a) a compound containing a pyridine nucleus, especially a 3-substituted pyridine and (b) a compound containing an oxirane ring such as an alkylene or arylene oxide, and yield a bright electrodeposit.
Claims13
In a process for electroplating zinc or cadmium from an aqueous bath, the improvement comprising employing as a brightening additive an effective brightening amount of a mixture produced by reaction in a liquid media selected from the group consisting of water and short-chain aliphatic alcohols and mixtures thereof of:
- a. a substituted pyridine in which the pyridine is substituted only with at least one member selected from the group consisting of cyano, alkyl, hydroxy, carboxy and carboxy salts with ammonia, amines and Groups I and II metals, --CONR.sup.1 R.sup.2 wherein R.sup.1 and R.sup.2 are individually selected from the group consisting of hydrogen, alkyl, and phenyl;
- and COOR.sup.3 ;
- wherein R.sup.3 is selected from the group consisting of alkyl, benzyl and phenyl;
- and
- b. an oxirane of the formula ##STR12## wherein R.sup.4, R.sup.5, R.sup.6 and R.sup.7 are each selected from the group consisting of hydrogen, alkyl, and alkyl and alkenyl interrupted by an ether linkage, and phenyl;
- the molar ratio of component (a) to component (b) being from 2:1 to 1:2.
In an aqueous plating bath for the electroplating of zinc or cadmium including an effective amount of brightening additive, the improvement comprising:
- said brightening additive being a mixture produced by reaction in a liquid media selected from the group consisting of water and short-chain aliphatic alcohols and mixtures thereof of
- a. a substituted pyridine in which the pyridine is substituted only with at least one member selected from the group consisting of cyano, alkyl, hydroxy, carboxy and carboxy salts with ammonia, amines and Groups I and II metals, --CONR.sup.1 R.sup.2 wherein R.sup.1 and R.sup.2 are individually selected from the group consisting of hydrogen, alkyl, and phenyl;
- and COOR.sup.3, wherein R.sup.3 is selected from the group consisting of alkyl, benzyl and phenyl;
- and
- b. an oxirane of the formula ##STR13## wherein R.sup.4, R.sup.5, R.sup.6 and R.sup.7 are each selected from the group consisting of hydrogen, alkyl, alkenyl, alkyl and alkenyl interrupted by an ether linkage, and phenyl;
- the molar ratio of component (a) to component (b) being from 2:1 to 1:2.
A brightening additive composition for the plating of zinc or cadmium comprising.
- A. a brightening additive selected from the group consisting of a synthetic polymer, a naturally occurring polysaccharide polymer, a proteinaceous substance and an aldehyde brightener;
- and
- B. a mixture produced by reaction in a liquid media selected from the group consisting of water and short-chain aliphatic alcohols and mixtures thereof of
- a. a substituted pyridine in which the pyridine is substituted only with at least one member selected from the group consisting of cyano, alkyl, hydroxy, carboxy and carboxy salts with ammonia, amines and Groups I and II metals, --CONR.sup.1 R.sup.2 wherein R.sup.1 and R.sup.2 are individually selected from the group consisting of hydrogen, alkyl, and phenyl;
- and COOR.sup.3, wherein R.sup.3 is selected from the group consisting of alkyl, benzyl and phenyl;
- and
- b. an oxirane of the formula ##STR14## wherein R.sup.4, R.sup.5, R.sup.6 and R.sup.7 are each selected from the group consisting of hydrogen, alkyl, alkenyl, alkyl and alkenyl interrupted by an ether linkage, and phenyl;
- the molar ratio of component (a) to component (b) being from 2:1 to 1:2.
Dependencies are inferred from the claim text.