J.m. Huber Corporation

Evonik Degussa Gmbh

Yung-Hui Huang

Patrick D McGill

Michel J Martin

Minas R Apelian

John V Offidani

Donald M Gury

Patrick D Mcgill

Minas R Apelain

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.

Method for making precipitated silica compositions and products thereof

Methods for the removal of lead from a metal silicate during the process of manufacturing of such a material are provided. With the reliance upon lower cost starting silicon dioxide starting materials that are known to exhibit elevated amounts of heavy metal therein for the purpose of producing metal silicates (such as sodium silicate, as one example), it has been realized that removal of significant amounts of such heavy metals is necessary to comply with certain regulatory requirements in order to provide a finished material that exhibits the same low level of heavy metal contamination as compared with finished materials that are made from more expensive, purer starting silicon dioxides. Two general methods may be followed for such decontamination purposes. One entails the introduction of a calcium phosphate material, such as dicalcium phosphate, tricalcium phosphate, and/or hydroxyapatite, to a formed metal silicate solution but prior to filtering. The other requires the introduction of calcium phosphate material (again, hydroxyapatite, tricalcium phosphate, and/or dicalcium phosphate) in a silicon dioxide, caustic, and water slurry with said dicalcium phosphate thus present throughout the overall reaction steps of metal silicate formation and is removed by filtering. In each situation, the hydroxyapatite, tricalcium phosphate, or dicalcium phosphate actually aids in rendering immobile the heavy metals therein, such as lead, cadmium, and the like, thereby preventing release of high amounts of bioavailable amounts of such heavy metals from products for which the target metal silicates are considered reactants. Thus, the heavy metal-containing metal silicates may then be utilized to produce precipitated silicas, as one example, that exhibit much lower levels of bioavailable heavy metals as compared with the original silicon dioxide source.

Method of removing heavy metals from silicate sources during silicate manufacturing

Method for making particulate compositions and products thereof

New methods of producing narrower particle size distribution precipitated silica and/or silicate materials are provided. Such a method permits a significant reduction in manufacturing costs through the utilization of more efficient drying/evaporation components, in essence, in one potentially preferred embodiment, production of such silica and/or silicate materials followed directly by a hydraulic chamber press filtering step combined with vacuum dewatering subsequently leading to the needed resultant particle comminution. The resultant precipitated silicas and/or silicates produced thereby exhibit greater density prior to comminution and thus greater propensity for more uniform milling than previously utilized and prevalent spray/flash drying apparatuses. Also encompassed within this invention are the resultant precipitated silica and/or silicate particles produced, including those that surprisingly exhibit extremely high transmittance properties, thereby potentially providing excellent narrow particle distribution silica materials for clear (transparent) end-uses.

Method for making precipitated silica or silicate compositions and products thereof

Method of making abrasive compositions comprised of water-insoluble abrasive polishing agents suspended in an aqueous medium in combination, which avoids the need and associated cost of dry milling the abrasive particle content, and products thereof. In particular, the abrasive compositions made by the method contain appropriately sized abrasive particles provided without the need for drying or dry milling, while also providing an abrasive composition which is Theologically stable, settling-resistant, and re-agglomeration resistant, even during and after transport and/or storage before end-use, such as incorporation into dentifrice formulations or other oral cleaning compositions.

Method for making abrasive compositions and products thereof

Method of making abrasive compositions comprised of water-insoluble abrasive polishing agents suspended in an aqueous medium in combination, which avoids the need and associated cost of dry milling the abrasive particle content, and products thereof. In particular, the abrasive compositions made by the method contain appropriately sized abrasive particles provided without the need for drying or dry milling, while also providing an abrasive composition which is rheologically stable, settling-resistant, and re-agglomeration resistant, even during and after transport and/or storage before end-use, such as incorporation into dentifrice formulations or other oral cleaning compositions.

Method of making abrasive compositions comprised of water-insoluble abrasive polishing agents suspended in an aqueous medium in combination using wet grinding, and products thereof. The abrasive compositions made by the method contain appropriately sized abrasive particles provided without the need for drying or dry milling, while also providing an abrasive composition which is theologically stable, settling-resistant, and re-agglomeration resistant, even during and after transport and/or storage before end-use, such as incorporation into dentifrice formulations or other oral cleaning compositions.

Methods of making dentifrice compositions including, as a raw material ingredient thereof, abrasive compositions comprised of water-insoluble abrasive polishing agents suspended in a liquid medium in combination with humectant, and the unique dentifrice compositions made in this manner.

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Bel Air, MD, United States of America

Yung-Hui Huang