Amorphous precipitated siliceous pigments and methods for their production
Patent 4144321 Issued on March 13, 1979. Estimated Expiration Date: 
March 13, 1996. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
March 13, 1996. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesInventorAssigneeApplicationNo. 05/653720 filed on 01/30/1976US Classes:424/49, DENTIFRICES (INCLUDES MOUTH WASH)106/492, Treatment of alkali silicate with mineral acid or product423/339, By precipitating424/52Fluorine or fluorine compound containingExaminersPrimary: Rose, Shep K.Attorney, Agent or FirmInternational ClassesA61K 8/22 (20060101)C09C 1/30 (20060101) C09C 1/28 (20060101) A61K 8/19 (20060101) A61Q 11/00 (20060101) AbstractA new method for producing precipitated silicas having a unique combination of physical and chemical properties is disclosed. The silicas are produced by acidulating a solution of an alkali metal silicate having a specific SiO2 /Na2 O mol ratio with an acid until precipitation just beings. At this point, the reaction mass is aged for a period of time and thereafter the acid addition is continued until the precipitated product is obtained. Products produced in accordance with the invention exhibit lower wet cake moisture and are characterized by their low structure, low oil absorption, high abrasiveness and high pack density, and as such are distinctly different from silicas used as reinforcing fillers in rubber. In a particularly advantageous embodiment, an adduct material, such as aluminum, is added to control the refractive index of the precipitated pigment. Products produced in this manner have particular utility for use as abrasion and gelling agents in clear toothpaste compositions.Other References
Field of SearchDENTIFRICES (INCLUDES MOUTH WASH)Ferment containing (e.g., enzymes, bacteria, etc.) Iodine or iodine compound containing Fluorine or fluorine compound containing Oxygen or chlorine releasing compound containing Ammonia, amine, or derivative thereof (e.g., urea, etc.) Hydroxy carboxylic acid or derivative thereof (e.g., methyl salicylate, etc.) Organic sulfate or sulfonate containing Phosphate compound containing Plant extract of undetermined constitution |
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