4 2 PRECIPITATED SILICA MATERIALS EXHIBITING HIGH COMPATIBILITY WITH CETYLPVRIDINIUM CHLORIDE ABSTRACT PRECIPITATED SILICA COMPRISING POROUS SILICA PARTICLES HAVING A CUMULATIVE SURFACE AREA FOR ALL PORES HAVING DIAMETERS GREATER THAN 500 A OF LESS THAN 6 M2/G, AS MEASURED BY MERCURY INTRUSION., AND A PERCENTAGE CETYLPYRIDINIUM CHLORIDE (% CPQ COMPATIBILITY OF GREATER THAN ABOUT 85%. THE PRECIPITATED SILICA PRODUCT IS ESPECIALLY WELL-ADAPTED FOR USE IN DENTIFFICES CONTAINING CETYLPYRIDINIUM CHLORIDE, WHICH DO NOT ATTACH TO THE LOW SURFACE AREA SILICA PRODUCT IN A MEANINGFUL LEVEL AND THUS REMAIN AVAILABLE FOR ANTIMICROBIAL ACTION. PROCESSES FOR MAKING THE SILICA PRODUCT INCLUDING THE INTRODUCTION OF SODIUM SULFATE POWDER DURING DIFFERENT PROCESS STEPS IN ORDER TO ENHANCE SUCH A COMPATIBILITY WITH CPC ARE PROVIDED.
