... premium grade purified high viscosity, high molecular weight, Polyanionic Cellulose polymer designed to provide viscosity and reduce API filtration rate to ... based drilling fluids.Application & FeaturesPAC R is a cost-effective additive to reduce API filtration rate of many water based drilling ... .9-1.2PH VALUE, 1% SOLUTION6.885.5-8.5API FLUID LOSS,ML12.216 MAXAPPEARANCE VISCOSITY55.050 MIN PAC R