Treated silicas and metal silicates for improved cleaning in dentifrice
View Patent ↗Treated silica materials are disclosed, together with methods of making such materials and dentifrice compositions comprising the treated silica materials.
1. A method for preparing a heat treated silica material, the method comprising heat treating a precipitated silica material comprising a metal, wherein the metal has a Mohs hardness value of at least about 5.5 in its oxide form, and wherein heat treating comprises heating the precipitated silica material at a temperature and for a period of time sufficient to produce the heat treated silica material, which is characterized by a loss on ignition at 900° C. of less than about 3 wt. %, and wherein:
an Einlehner abrasion value of the heat treated silica material is from about 90% to about 450% greater than an Einlehner abrasion value of the precipitated silica material.
2. The method of claim 1 , wherein heat treating comprises heating the precipitated silica material at a temperature of at least about 400° C. for at least about 8 hours.
3. The method of claim 1 , wherein heat treating comprises heating the precipitated silica material at a temperature of at least about 550° C. for at least about 8 hours.
4. The method of claim 1 , wherein the heat treated silica material has a metal concentration of from about 1 wt. % up to about 10 wt. %.
5. The method of claim 1 , wherein the precipitated silica material is prepared by contacting a silicate solution, an acidulating agent, and a soluble metal salt, wherein the soluble metal salt comprises a metal ion having a Mohs hardness value of at least 5.5 in its oxide form.
6. The method of claim 5 , wherein the metal ion comprises one or more of aluminum, tin, or a combination thereof.
7. The method of claim 5 , wherein the metal ion comprises aluminum.
8. The method of claim 5 , wherein the metal ion comprises tin.
9. A heat treated silica material prepared by the method of claim 1 .
10. A dentifrice composition comprising the heat treated silica material of claim 9 .
11. A method for preparing a dentifrice material, the method comprising heat treating a precipitated silica material comprising aluminum and/or tin at a temperature of from about 400° C. to about 900° C. to form a heat treated silica material, and then contacting the heat treated silica material with one or more dentifrice components to form the dentifrice material; wherein:
the heat treated silica material has a loss on ignition at 900° C. of less than about 3 wt. %, which wherein
an Einlehner abrasion value of the heat treated silica material is from about 90% to about 450% greater than an Einlehner abrasion value of the precipitated silica material.
12. The method of claim 11 , wherein heat treating comprises heating the precipitated silica material at a temperature of from about 400° C. to about 900° C. for at least about 8 hours.
13. The method of claim 11 , wherein heat treating comprises heating the precipitated silica material at a temperature of from about 550° C. to about 900° C. for at least about 8 hours.
14. A dentifrice material prepared by the method of claim 11 .
15. The method of claim 1 , wherein the precipitated silica material comprises silica particles.
16. The method of claim 1 , wherein the precipitated silica material comprises aluminosilicate particles.
17. The method of claim 1 , wherein the metal comprises aluminum, tin, or a combination thereof.
18. The method of claim 5 , wherein the metal salt comprises a sulfate, a nitrate, a phosphate, or a carbonate of aluminum or tin.
19. A precipitated silica material comprising from about 1 wt. % to about 10 wt. % of a metal having a Mohs hardness value of at least 5.5 in its oxide form, and wherein the precipitated silica material is characterized by:
a loss on ignition at 900° C. of less than about 3 wt. %; and
a pellicle cleaning ratio (PCR) at 20% loading of at least 90.
20. The silica material of claim 19 , wherein the metal comprises aluminum.
21. The silica material of claim 19 , wherein the metal comprises tin.
22. The silica material of claim 19 , wherein the precipitated silica material comprises aluminosilicate particles.
23. The silica material of claim 19 , wherein the precipitated silica material is further characterized by an Einlehner abrasion value in a range from 18 to 34.8 mg lost/100,000 revolutions.
24. A dentifrice composition comprising the silica material of claim 19 .