Method for making particulate compositions and products thereof

Abstract

A method of making abrasive compositions, and more particularly, it relates to a method of making precipitated silica abrasive compositions having excellent cleaning performance and lower abrasiveness with post-reactor sizing of the abrasive particles being performed directly via wet comminution and centrifugation, optionally followed by hydraulic chamber press filtering combined with vacuum dewatering and de-agglomeration is provided. By targeting a specific particle size range, it has been determined that higher pellicle film cleaning levels may be achieved without also increasing the dentin abrasion properties of the silica products themselves. As a result, dentifrices including such classified abrasive silica products, exhibiting particularly desirable cleaning benefits, can be provided for improved tooth polishing, whitening, and the like, without deleteriously affecting the hard tooth surfaces. Also encompassed within this invention also are products of this selective process scheme and dentifrices containing such particularly manufactured and classified silica products.

Description

FIELD OF THE INVENTION [0001] This invention relates to a method of making abrasive compositions, and more particularly, it relates to a method of making precipitated silica abrasive compositions having excellent cleaning performance and lower abrasiveness with post-reactor sizing of the abrasive particles being performed directly via wet comminution and centrifugation, optionally followed by hydraulic chamber press filtering combined with vacuum dewatering and de-agglomeration. By targeting a specific particle size range, it has been determined that higher pellicle film cleaning levels may be achieved without also increasing the dentin abrasion properties of the silica products themselves. As a result, dentifrices including such classified abrasive silica products, exhibiting particularly desirable cleaning benefits, can be provided for improved tooth polishing, whitening, and the like, without deleteriously affecting the hard tooth surfaces. Also encompassed within this invention ...

AI Technical Summary

Benefits of technology

[0007] It is thus one advantage of this invention to provide an all-inclusive method of manufacturing dental abrasive particles that exhibit proper particle size ranges for effective pellicle film cleaning and moderate dentin abrasion characteristics once manufacturing is completed and said particles are thus collected. Thus, no dry post-reactor comminution or other type of particle modification is necessary to provide the desired particle size ranges for effective high cleaning and moderate dentin abrasion properties exhibited by the produced dental abrasives.

[0009] The basic inventive method entails the production of abrasive compositions, comprised of water-insoluble abrasive polishing agents suspended in an aqueous medium, wherein milling to desired particle size ranges is effectuated via a wet process during actual abrasive product manufacture. Such a method thus avoids the need and associated cost of dry milling the abrasive particle content, and products thereof. It has also been realized that such a wet milling method permits production of appropriately sized abrasive particles and compositions thereof that are rheologically stable, are not prone to settling, and do not exhibit any appreciable level of re-agglomeration, even during and after transport and / or storage before end-use, such as incorporation into dentifrice formulations or other oral cleaning compositions.

[0012] Basically, it has been realized that the inventive method provides the capability of easily producing low-structure abrasive silica materials within a concentrated range of specific particle sizes permits greater uniformity in performance during tooth cleaning with a dentifrice containing such materials with minimal process steps and thus concomitant lower associated costs. Likewise, providing such materials within the specific range of particle sizes permits targeting particular areas of tooth surfaces for proper cleaning without simultaneously exhibiting excessive abrasive levels.

Problems solved by technology

Pellicle film is tightly adherent and often contains brown or yellow pigments, which impart an unsightly appearance to the teeth.

Although such previous products have accorded excellent benefits in these areas, it has been noted that certain limitations in terms of production costs and waste generation are prevalent as a result.

The same types of production issues and problems arise when targeting certain lower abrasive levels for particulate materials without sacrificing pellicle film cleaning as well.

Images