2,3-Dihydroxybutanedioic Acid → Gluconic Acid

Participants

Reaction Steps

An aqueous cobalt-zinc electrolyte is prepared as in Example 7 but containing 50 g/l tartaric acid instead of sodium glucoheptonate. A nickel plated S-shaped steel panel is plated for 10 minutes at 15 ASF in accordance with the conditions of Example 2. The resultant cobalt-zinc electrodeposit is observed as being more gray in color than that obtained in accordance with Example 6 employing gluconic acid alone. The addition of 10 g/l of citric acid in combination with the 50 g/l tartaric acid followed by pH adjustment resulted in the deposition on a similar S-shaped steel panel of a cobalt-zinc electrodeposit which was of uniform brightness over the entire surface and had an excellent chromium-like appearance equivalent to that obtained in Example 2.

Provenance & Evidence