Compositions for imparting water resistance to gypsum wallboards

A composition for use as an additive in the manufacture of gypsum wallboards for imparting water resistance to the manufactured gypsum wallboard, said composition comprising:

• a) an aqueous emulsion of Kraft lignin, wax, water, and a base, wherein:
• the wax is in a molten state;
• the base is present in an amount sufficient to solubilize the Kraft lignin;
• and,
• the weight ratio of Kraft lignin to wax, α, is at least about 0.25;
• or
• b) an aqueous dispersion comprising a Kraft lignin, wax, water, and a base, wherein:
• the wax forms the solid phase;
• the base is present in an amount sufficient to solubilize the Kraft lignin;
• and,
• the weight ratio of Kraft lignin to wax, α, is from about 0.09 to about 2.25.