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US 4,046,648 AGranted
Polyamine additives in alkaline zinc electroplating
AssigneeE. I. Du Pont de Nemours and Company
InventorJohn Derek Rushmere
Life of this patent
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Abstract
Alkaline zinc electroplating, from baths with small amounts of cyanide or cyanide-free, is enhanced by the use of certain water-soluble polyamines as brighteners. These are the reaction products of first condensing an alkanolamine with an epihalohydrin, and then reacting the condensation product with an amine.
Claims25
An aqueous addition agent for the electrodeposition of zinc from an alkaline bath, said addition agent comprising a water-soluble polyamine brightener prepared by
- condensing an alkanolamine with an epihalohydrin in proportions of at least about 2 moles of epihalohydrin per mole of alkanolamine to produce a condensation product which is essentially completely water-soluble and free from epihalohydrin, and
- reacting said condensation product with at least 0.3 mole of ammonia or an amine other than an alkanolamine per mole of alkanolamine until the total ionic halogen is at least about 1 mole per mole of alkanolamine.
Dependencies are inferred from the claim text.