Formaldehyde → Morwet D 425

Participants

Reaction Steps

1 mol of naphthalene (128.2 g) was reacted with 1.28 mol of sulfuric acid (125.5 g) for 3 hours at 150° C. to 160° C. To the product (sulfonate) were added 44 g of water, and formalin (37% formaldehyde in water) in such amount as equal to 0.98 mol of formaldehyde dropwise over 3 hours at 90° C. The mixture was reacted for condensation for 10 hours at 100±2° C. The mixture was cooled to room temperature, neutralized to pH 5 with calcium hydroxide, and filtrated to remove generated precipitates (gypsum), resulting in an aqueous solution of a naphthalenesulfonic acid-formaldehyde condensate (B-1). The polymer was dried for 24 hours at 105° C. The aqueous solution was adjusted to an intended concentration to be used according to need.

Provenance & Evidence