The sodium salt of an acid that may be extracted with alkali from redwood dust. The dark reddish-brown material consists mainly of a partially methylated phenolic acid containing aliphatic hydroxyls, phenolic hydroxyls, and carboxyl groups in the ratio of 2:4:3. The viscosity of aqueous solutions rises rapidly with concentration.
Use:
To control viscosity and water loss in drilling muds and as a dispersing agent.