Abstract: A method for preparing a titanium on silica catalyst, in the form of formed particles such as macrospheres, achieves a controlled titanium distribution type, namely either uniform, eggshell, or intermediate, by selecting the particular titanium precursor depending on its reactivity with hydroxyl groups and by selecting the molar titanium:hydroxyl ratio. Selecting a titanium precursor with a low reactivity and/or adding sufficient titanium precursor to achieve a high molar titanium:hydroxyl ratio aids in forming a uniform distribution of titanium. On the other hand, selecting a titanium precursor with a high reactivity and/or adding only a little titanium precursor resulting in a low molar titanium:hydroxyl ratio aids in forming an eggshell distribution of titanium.

Abstract: A method for preparing a titanium on silica catalyst, in the form of formed particles such as macrospheres, achieves a controlled titanium distribution type, namely either uniform, eggshell, or intermediate, by selecting the particular titanium precursor depending on its reactivity with hydroxyl groups and by selecting the molar titanium:hydroxyl ratio. Selecting a titanium precursor with a low reactivity and/or adding sufficient titanium precursor to achieve a high molar titanium:hydroxyl ratio aids in forming a uniform distribution of titanium. On the other hand, selecting a titanium precursor with a high reactivity and/or adding only a little titanium precursor resulting in a low molar titanium:hydroxyl ratio aids in forming an eggshell distribution of titanium. In particular, the method involves first preparing formed particles, such as macrospheres, of silica hydrogel then drying the formed particles.

Abstract: Crystalline alumino-silicates (zeolites) are multifunctional in dentifrice compositions thereby reducing the number of components required in such formulations. The pH-adjusted zeolites can keep the pH of the dentifrice in the range where caries formation is impossible. The pH-adjusted synthetic or natural zeolites can be prepared or obtained in a particle size range that provides both abrasive cleansing and polishing or lustering of the teeth. The fine particle size and water absorbing capabilities of the zeolite can also provide thickening. Such multifunctional performance allows considerable simplification in the formulation of dentrifice compositions.

Abstract: Silicas that provide improved abrasive action when incorporated in dentifrice compositions can be prepared by dehydrating a silica hydrogel to a low water content and then reintroducing water to gel. The silica hydrogel is prepared by neutralizing a sodium silicate with an acid. This hydrogel is dried by any convenient method so that the gel contains about 15% water or less. This dried gel is rehydrated to about 30% or more. The rehydrated gel provides improved abrasion values over the prior art xerogels and hydrogels.