ACIDIC ELECTROLYTE FOR ELECTROLYTICALLY DEPOSITING COATINGS FROM TIN- LEAD ALLOY Russian patent published in 1997 - IPC

FIELD: metal coatings. SUBSTANCE: electrolyte contains, g/l: tin methanesulfonate, 12-40 (on conversion to metal); lead methanesulfonate, 6-25 (on conversion to metal); methanesulfonic acid, 100-350; nonionic surfactant, 10-30; formaldehyde (as 37% solution), 5-30 ml/l; brightener composition, 2.95-27.5. The latter composition, in turn, contains (in g per 1 l of electrolyte): α,β-unsaturated aldehyde, 0.12-3.7; high-molecular unsaturated or polyatomic alcohol, 0.03-7; low-molecular alcohol, 1.8-14.8; and aminophenol, 1-2. Electrolyte exhibits high scattering capability (high than 60%), wide range of allowable cathode current densities (2-15 A/sq.dm), and alloy deposition rate up to 7 mcm/min. EFFECT: facilitated coating deposition process. 1 tbl