High Cleaning Silica With Low Abrasion And Method Of Making Same

1 - 14 . (canceled)

15 . A method for preparing a silica material, the method comprising:

a. contacting a silicate compound or a solution thereof with an acid in the presence of a salt or solution thereof, to form a precursor material, and

b. subjecting the precursor material to hydrothermal conditions.

16 . The method of claim 15 , wherein the silicate compound comprises a metal:silicate molar ratio of from about 1:1 to about 1:3.5.

17 . The method of claim 15 , wherein the hydrothermal conditions comprise heating to a temperature of from about 160° C. to about 220° C. for a period of from about 1.5 to about 2 hours.

18 . The method of claim 15 , wherein the hydrothermal conditions comprise a pressure of from about 150 psi to about 300 psi.

19 - 20 . (canceled)

21 . The method of claim 15 , wherein the silicate compound comprises sodium silicate.

22 . The method of claim 15 , wherein the salt comprises sodium sulfate, sodium phosphate, sodium chloride, or a combination thereof.

23 . The method of claim 15 , wherein the acid comprises nitric acid, hydrochloric acid, phosphoric acid, boric acid, hydrofluoric acid, sulfuric acid, or a combination thereof.

24 . The method of claim 15 , wherein the acid comprises sulfuric acid.

25 . The method of claim 15 , wherein the silica material comprises silica.

26 . The method of claim 15 , wherein the silica material comprises sodium aluminosilicate.

27 . The method of claim 15 , wherein the hydrothermal conditions comprise a temperature of from about 100° C. to about 350° C. in a sealed vessel.

28 . The method of claim 15 , wherein the hydrothermal conditions comprise a pressure of from about 150 psi to about 300 psi and a temperature of from about 120° C. to about 240° C. in a sealed vessel.

29 . The method of claim 15 , wherein the method further comprises, after step b, a pH adjusting step, a filtering step, a washing step, a drying step, or any combination thereof, to form the silica material.

30 . The method of claim 29 , wherein the BET surface area of the silica material is less than that of the precursor material.

31 . The method of claim 29 , wherein the silica material comprises an agglomeration of dense spherical and/or partially spherical particles.

32 . The method of claim 31 , wherein the spherical and/or partially spherical particles have an average diameter of about 80 nm.

33 . The method of claim 29 , wherein the silica material has a level of crystallinity of less than about 1%.

34 . The method of claim 29 , wherein the silica material is characterized by:

(a) a BET surface area of from about 5 m 2 /g to about 45 m 2 /g;

(b) an oil absorption number of at least about 80 cc/100 g;

(c) a loss on ignition of less than about 4 wt. %; and

(d) a PCR:RDA ratio of at least about 0.8 in a dentifrice comprising 11 wt. % glycerine (99.7%), 42.107 wt. % sorbitol (70%), 20 wt. % deionized water, 3 wt. % polyethylene glycol (PEG-12), 0.6 wt. % sodium carboxymethylcellulose, 0.5 wt. % tetrasodium pyrophosphate, 0.2 wt. % sodium saccharin, 0.243 wt. % sodium fluoride, 0.5 wt. % titanium dioxide, 1.2 wt. % sodium lauryl sulfate, 0.65 wt. % flavoring, and 20 wt. % of the silica material.

35 . The method of claim 15 , wherein:

the silicate compound comprises sodium silicate;

the salt comprises sodium sulfate;

the acid comprises sulfuric acid; and

the hydrothermal conditions comprise a temperature of from about 100° C. to about 350° C. in a sealed vessel.

36 . The method of claim 35 , wherein the method further comprises, after step b, a filtering step, a washing step, and a drying step, to form the silica material.

37 . The method of claim 36 , wherein:

the BET surface area of the silica material is less than that of the precursor material; and

the median particle size of the silica material is greater than that of the precursor material.