| 摘要 |
A color containing silica resistant to dye migration is provided, and, more particularly, such as a silica for use as a colorant in various formulations, particularly dentifrices. The invention also relates to a method of making the color containing silica. The method comprises providing a silica slurry which includes a plurality of silica particles, depositing alum in the pores of the silica particles, reacting a base with the alum to convert the alum into aluminum hydroxyde resulting in treated silica particles. The treated silica particles are then filtered and washed. Thereafter, a dye is mixed with the treated silica particles. The resultant dyed silica product is resistant to dye migration.
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