Precipitated silica product, dentifrices containing same, and processes
AssigneeJ.M. Huber Corporation
InventorsKarl W. Gallis, Mark E. Wozniak, John A. Kostinko
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Abstract
Precipitated silica comprising porous silica particles having a cumulative surface area for all pores having diameters greater than 500 Å of less than 8 m2/g, as measured by mercury intrusion, and a percentage cetylpyridinium chloride (% CPC) Compatibility of greater than about 55%. The precipitated silica product is especially well-adapted for use in dentifrices 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 are also provided.
Claims30
Precipitated silica comprising silica product particles having a porous surface, the silica particles having a cumulative surface area for all pores having diameters greater than about 500 Å of less than 8 m2/g, as measured by mercury intrusion, a BET specific surface area of less than approximately 30 square meters per gram, and a percentage cetylpyridinium chloride (% CPC) Compatibility of greater than about 55%.
Dentifrice, comprising:
- a silica product comprising silica particles having a porous surface, the silica particles having a cumulative surface area for all pores having diameters greater than about 500 Å of less than 8 m2/g, as measured by mercury intrusion, a BET specific surface area of less than approximately 30 square meters per gram, and a percentage cetylpyridinium chloride (% CPC) Compatibility of greater than about 55%.
Dentifrice, comprising:
- a) antibacterial effective amount of cetylpyridinium chloride;
- b) precipitated silica product comprising silica particles having a porous surface, the silica particles having a cumulative surface area for all pores having diameters greater than about 500 Å of less than 8 m2/g, as measured by mercury intrusion, a BET specific surface area of less than approximately 30 square meters per gram, and a percentage cetylpyridinium chloride (% CPC) Compatibility of greater than about 55%.
Process for making precipitated silica product, comprising:
- a)
- providing amorphous silica substrate particles having a median diameter of 1 to 100 micrometers;
- b) depositing active silica onto surfaces of the silica substrate particles by acidulation of an alkali metal silicate in an aqueous medium, in which the substrate particles are dispersed, in an amount effective to provide a slurry of silica particles having a porous surface, the silica particles having a cumulative surface area for all pores having diameters greater than about 500 A of less than 8 m2/g, as measured by mercury intrusion, and a percentage cetylpyridinium chloride (% CPC) Compatibility of greater than about 55%.
Dependencies are inferred from the claim text.