Dentifrice abrasives and compositions

• US 5,225,177 A
• Filed: 01/19/1990
• Issued: 07/06/1993
• Est. Priority Date: 01/19/1990
• Status: Expired due to Fees

• Current Assignee: JM Huber Corporation
• Original Assignee: JM Huber Corporation
• Inventors: Fultz, William C., Wason, Satish K.
• Primary Examiner(s): Bell, Mark L.
• Assistant Examiner(s): Einsmann, Margaret
• Application Number:
  US07/467,423
• Time in Patent Office: 1,264 Days
• Field of Search: 51/308, 51/298, 423/324, 423/325, 423/335, 423/339
• US Class Current: 423/339
• CPC Class Codes: A61K 8/042 Gels
• 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
• CPC Class Codes: C01B 33/193 of aqueous solutions of silicates
• CPC Class Codes: C01P 2002/02 Amorphous compounds
• CPC Class Codes: C01P 2004/61 Micrometer sized, i.e. from 1-100 micrometer
• CPC Class Codes: C01P 2006/10 Solid density
• CPC Class Codes: C01P 2006/19 Oil-absorption capacity, e.g. DBP values
• CPC Class Codes: C01P 2006/60 Optical properties, e.g. expressed in CIELAB-values
• CPC Class Codes: C01P 2006/82 water content
• CPC Class Codes: C01P 2006/90 Other properties not specified above

Abstract

Novel precipitated silicon dioxide abrasive compositions which can be incorporated into therapeutic toothpaste compositions containing soluble fluoride salts are disclosed. The abrasives comprise low structure, high fluoride compatible amorphous precipitated silicon dioxides (silicas) having a controlled refractive index for use in low water clear gel dentifrice applications. Also provided are methods for preparation of the novel silicon dioxide abrasives and resulting toothpaste formulations containing such abrasives.

Claims

1. A low structure amorphous silicon dioxide prepared b adding a 13.3% solution of 2.65 Molar Ratio sodium silicate at 183°

F. for 0.75 minutes to fresh water, continuing said addition of sodium silicate and adding 11.4% sulfuric acid for 60.75 minutes, said acid being added at the rate of 36.5 gpm and said sodium silicate being added at the rate of 71.3 gpm;

adjusting the pH to 5.2 and digesting for 10 minutes at 205°

F. and thereafter adjusting the pH to 5.3 to produce a product having 10% moisture, 5% pH of 7.0, oil absorption of 100 cc/100 gm, a refractive index of 1.45, an APS of 11 microns, a density of 17 lbs/cu. ft and a BET surface area of 50 to 250 m² g.

2. A low structure amorphous silicon dioxide characterized by containing 10 wt % moisture, 5% pH of 7.0, oil absorption of less than 125 cc/100 gm, a refractive index of 1.45;

an APS of 11 microns, a density of 17 lbs/cu.ft., a percent abrasive fluoride compatibility of at least 90 percent, and a BET surface area of 50 to 250 m² /g.