Water → Nitric Acid

Participants

Reaction Steps

The preparation of the Levanyl Black involves rolling 5 g of Levanyl Black in about 572 g of water and the preparation of the Nigrosin Black involves rolling 2–3 g of the Nigrosin Black in about 420 g of water. The Nigrosin Black solution should have a pH of 3.0–6.0 which can be obtained with the addition of an appropriate quantity of 10% nitric acid after the Nigrosin Black is rolled. In this example, the order of ingredients is particularly important for obtaining a stable formulation. Experiments have shown that an intermediate silicate formulation should be made in a separate vessel by first adding the acid to about 20 g of water followed by the addition of the alcohol and organic silicate. Next, the contents of the separate vessel should be shaken to hydrolyze the organic silicate, thereby creating the intermediate silicate formulation. The solvent and remaining water should then be mixed into the separate vessel, thereby making a diluted intermediate silicate formulation. The general conclusion is that it is best to dilute the intermediate formulation with a slow evaporating organic solvent such as 1-propanol and water. The reason is that the final formulation will flash-off more slowly during application and, in turn, provide a glossier finish.

Provenance & Evidence