TRANSPARENT SILICA GEL/PRECIPITATED SILICA COMPOSITE MATERIALS FOR DENTIFRICES

• US 20090297459A1
• Filed: 05/20/2009
• Published: 12/03/2009
• Est. Priority Date: 06/03/2008
• Status: Abandoned Application

• Current Assignee: JM Huber Corporation
• Original Assignee: JM Huber Corporation
• Inventors: McGill, Patrick Donald, Hua, Duen-Wu, Fultz, William C.
• Application Number:
  US12/468,910
• Publication Number:
  US 20090297459A1
• Time in Patent Office: Days
• US Class Current: 424/49
• CPC Class Codes: A61K 8/044 Suspensions
• CPC Class Codes: A61K 8/25 Silicon; Compounds thereof
• CPC Class Codes: A61Q 11/00 Preparations for care of the teeth, of the oral cavity or of dentures; Dentifrices, e.g. toothpastes; Mouth rinses

Abstract

A gel/precipitate silica composite for use in a dentifrice composition has a maximum light transmission of at least 25% within a refractive index range of from about 1.432 to about 1.455; a relative flavor availability as compared to silica sand of at least 50%; a CTAB of less than about 40; and, when incorporated into a dentifrice composition in an amount of 20% by weight, said dentifrice has a RDA (Relative Dentin Abrasion) value of at most 130; a PCR (Pellicle Cleaning Ratio):RDA ratio of from 0.7 to 1.3; and a haze value after 24 hours of less than about 50%.

Claims

1. A gel/precipitate silica composite for use in a dentifrice composition, wherein said composite has a maximum light transmission of at least 25% within a refractive index range of from about 1.432 to about 1.455;

a relative flavor availability as compared to silica sand of at least 50%;

a CTAB of less than about 40; and

, when incorporated into a dentifrice composition in an amount of 20% by weight, said dentifrice has a RDA (Relative Dentin Abrasion) value of at most 130;

a PCR (Pellicle Cleaning Ratio);

RDA ratio of from 0.7 to 1.3; and

a haze value after 24 hours of less than about 50%.

2. The gel/precipitate silica composite of claim 1 wherein the maximum light transmission of the composite is at least 40%.

3. The gel/precipitate silica composite of claim 1 wherein the refractive index range is from about 1.435 to about 1.445.

4. The gel/precipitate silica composite of claim 1 wherein the maximum light transmission of the composite is at least 40% and the refractive index range is from about 1.435 to about 1.445.

5. The gel/precipitate silica composite of claim 1 wherein the relative flavor availability as compared to silica sand is at least 75%.

6. The gel/precipitate silica composite of claim 1 wherein the relative flavor availability as compared to silica sand is at least 85%.

7. The gel/precipitate silica composite of claim 1 wherein the CTAB of the composite is from about 9 to about 35.

8. The gel/precipitate silica composite of claim 1 wherein the CTAB of the composite is from about 12 to about 25.

9. The gel/precipitate silica composite of claim 1 wherein said dentifrice has a RDA of at most 120.

10. The gel/precipitate silica composite of claim 1 wherein said dentifrice exhibits a PCR:

RDA ratio of from 0.8 to 1.0.

11. A dentifrice comprising the gel/precipitate composite of any one of claims 1 to 10.

12. A method of producing a gel/precipitate silica composite for use in a dentifrice composition, wherein said composite has a maximum light transmission of at least 25% within a refractive index range of from about 1.432 to about 1.455;

a relative flavor availability as compared to silica sand of at least 50%;

a CTAB of less than about 40; and

, when incorporated into a dentifrice composition in an amount of 20% by weight, said dentifrice has a RDA value of at most 130;

a PCR;

RDA ratio of from 0.7 to 1.3; and

a haze value after 24 hours of less than about 50%, said method comprising the sequential steps of

a. admixing an electrolyte, an alkali silicate. and an acidulating agent to form a silica gel in a reaction medium; and

, without first washing, modifying, or purifying said silica gel,

b. subsequently introducing to said reaction medium comprising said silica gel of step (a) a sufficient amount of an alkali silicate and an acidulating agent to form a precipitated silica, thereby producing a gel/precipitate silica composite.

13. The method of claim 12, wherein subsequent to step (a), the reaction medium is subjected to high shear conditions.

14. The method of claim 12, wherein the electrolyte is an alkali metal salt or an alkaline earth metal salt.

15. The method of claim 12, wherein the electrolyte is sodium sulfate.

16. The method of claim 12, wherein step (a), the electrolyte is introduced at a weight ratio of concentration of about 0.5% to about 2.5% based on the total batch aqueous solution.

17. The method of claim 12, wherein an electrolyte is introduced in step (b).

18. The method of claim 17, wherein the electrolyte of step (b) is sodium sulfate.

19. A method of producing a gel/precipitate silica composite for use in a dentifrice composition, wherein said composite has a maximum light transmission of at least 25% within a refractive index range of from about 1.432 to about 1.455;

a relative flavor availability as compared to silica sand of at least 50%;

a CTAB of less than about 40; and

, when incorporated into a dentifrice composition in an amount of 20% by weight, said dentifrice has a RDA value of at most 130;

a PCR;

RDA ratio of from 0.7 to 1.3; and

a haze value after 24 hours of less than about 50%, said method comprising the sequential steps of

a. admixing an electrolyte, an aqueous solution of an alkali silicate having a concentration of from about 3% to about 35%, and an aqueous solution of an acidulating agent having an acid concentration of from about 4% to about 35% together at a temperature from about 40 to about 90°

C. and under agitation to form a silica gel in a reaction medium; and

, without first washing, modifying, or purifying said silica gel,

b. subsequently introducing to said reaction medium comprising said silica gel of step (a) a sufficient amount of an alkali silicate and an acidulating agent to form a precipitated silica, thereby producing a gel/precipitate silica composite, wherein the pH of the overall reaction is within the range of from 3 to 10.

20. The method of claim 19, wherein subsequent to step (a), said reaction medium is subjected to high shear conditions.