Improvements in phosphatizing baths, and chiefly in baths containing phosphates of iron, phosphate of zinc or phosphate of manganese

摘要

526,326. Coating metals. KAHN, R. JACQUES-. March 13, 1939, No. 8055. [Class 82 (ii)] In treating metal surfaces with phosphate baths, particularly phosphates of iron, zinc, or manganese, there is added to the bath from time to time, and preferably before each operation, a mixture of a substance to neutralize acidity, particularly manganese carbonate, and an accelerator which may be a compound of hydrosulphurous acid with an aldehyde such as acetaldehyde or formaldehyde, or the product known under the Registered Trade Mark " Rongalite."