Baths and additives for the electrodeposition of bright zinc
AssigneeColumbia Chemical Corporation
InventorWilliam E. Rosenberg
Life of this patent
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Abstract
A zinc brightener additive comprises a polymeric amine selected from the class consisting of a linear aliphatic amine polymer, an aminated polyepichlorohydrin, a polyethylenimine, and combinations thereof, and a propylene oxide-ethylene oxide block copolymer prepared by the sequential addition of propylene oxide followed by ethylene oxide, or vice versa, to a residue of an organic compound containing active hydrogen atoms such as propylene glycol or an amine base. Additionally, an aqueous acid electroplating bath containing the polymeric amine compound in combination with the propylene oxide-ethylene oxide and block copolymer provides bright, lustrous electrodepositions of zinc. Moreover, aromatic aldehydes and ketones may be utilized to provide extremely bright electrodepositions of zinc.
Claims35
A zinc brightener additive comprising, from about 1 percent to about 99 percent by weight of a polymeric amine selected from the class consisting of;
- a linear aliphatic amine polymer prepared by reacting from about 50 percent to about 200 percent of a stoichiometric amount of an epihalohydrin selected from the class consisting of epichlorohydrin and epibromohydrin with a linear aliphatic polyamine selected from the class consisting of a compound having at least two primary amine groups, two secondary amine groups, one primary and one secondary amine group,
- said amine groups separated by two through six methylene groups or alkyl substituted methylene groups,
- an aminated polyepichlorohydrin prepared by reacting polyepichlorohydrin with an amine selected from the group consisting of secondary aliphatic amines and secondary alicyclic amines at a temperature of from about 110.degree. C. to about 170.degree. C., the amount of said amines is such so that between 50 percent to 100 percent of the chloro groups in said polyepichlorohydrin is reacted,
- a polyethylenimine having the repeating unit:
- ##STR5## where R is hydrogen, methyl, ethyl, propyl, isopropyl, hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 2-aminoethyl, 2-aminopropyl, and 3-aminopropyl, and y is about 10 to about 100, and combinations thereof, and
- including from about 99 percent to about 1 percent by weight of a propylene oxide-ethylene oxide block copolymer having a molecular weight of more than 500, said block copolymer prepared by the sequential addition of propylene oxide and ethylene oxide, in either order, to a residue of any organic compound containing a plurality of active hydrogen atoms.
An aqueous acid zinc eletroplating bath for producing a bright electrodeposition of zinc, containing zinc ions, comprising;
- having dissolved therein from about 0.5 to about 10 grams/liter of a polymeric amine selected from the class consisting of,
- a linear aliphatic amine polymer prepared by reacting from about 50 percent to about 200 percent of a stoichiometric amount of an epihalohydrin selected from the class consisting of epichlorohydrin and epibromohydrin with a linear aliphatic polyamine selected from the class consisting of a compound having at least two primary amine groups, two secondary amine groups, one primary and one secondary amine group, said amine groups separated by two through six methylene groups or alkyl substituted methylene groups,
- an aminated polyepichlorohydrin prepared by reacting polyepichlorohydrin with an amine selected from the group consisting of secondary aliphatic amines and secondary alicyclic amines at a temperature of from about 110.degree. C. to about 170.degree. C., the amount of said amines is such so that between 50 percent to 100 percent of the chloro groups in said polyepichlorohydrin is reacted,
- a polyethylenimine having the repeating unit:
- ##STR6## where R is hydrogen, methyl, ethyl, propyl, isopropyl, hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 2-aminoethyl, 2-aminopropyl, and 3-aminopropyl, and y is about 10 to about 100, and combinations thereof, and
- including from about 1 to about 10 grams/liter of a propylene oxide-ethylene oxide block copolymer having a molecular weight of more than 500, said copolymer prepared by sequential addition of propylene oxide and ethylene oxide, in either order, to a residue of any organic compound containing a plurality of active hydrogen atoms.
Dependencies are inferred from the claim text.