Formaldehyde → Morwet D 425

Participants

Reaction Conditions

Reaction Steps

A charge of 64 g (0.5 mole) of naphthalene was heated to 160° C. and 75 g (0.75-0.765 mole) of 98-100% strength sulfuric acid was added. The reaction mixture was maintained for 2 hours at 160° C. under constant stirring, was then cooled to 100° C. and 20 g of water added. Then 40 g of 37% by weight formaldehyde solution and 80 g of water were added and the reaction mixture maintained at 100° C. for 4 hours to obtain a naphthalene sulfonic acid formaldehyde condensate solution. The condensate solution was added to a milk of lime mixture containing 37 g of lime and 56 g water, to which was then added 166 g of crystalline aluminum sulfate dissolved in 300 grams of water. Calcium sulfate was filtered off and a 20% by weight solution of the aluminum salt of the naphthalene sulfonic acid formaldehyde condensate obtained.

Provenance & Evidence