Method of producing granular amorphous silica
Patent 5989510 Issued on November 23, 1999. Estimated Expiration Date: 
June 17, 2016. 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.
June 17, 2016. 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 ReferencesCosmetics and process for preparation thereof Spherical granules of porous silica or silicate, process for the production thereof, and applications thereof Patent #: 5342876 InventorsAssigneeApplicationNo. 670240 filed on 06/17/1996US Classes:423/339By precipitatingExaminersPrimary: Bos, StevenAssistant: Hendrickson, Stuart L. Attorney, Agent or FirmInternational ClassC01B 033/12Foreign Application Priority Data1993-12-28 JPAbstractA method of directly precipitating a spherical amorphous silica in a high yield by adding a carboxymethyl cellulose (CMC) as a coagulation growing agent in a step of neutralizing the alkali silicate with an acid. The CMC having a particular etherification degree and a particular polymerization degree is added in an amount of from 1 to 100% by weight reckoned as SiO2 with respect to silica in the alkali silicate, whereby the whole silica particles turn into spherical amorphous silica particles having high sphericalness. There can be obtained spherical amorphous silica particles having a BET specific surface area of from 25 to 800 m2 /g, an apparent specific gravity of from 0.1 to 0.8 and a particle diameter of from 0.2 to 50 μm cheaply and in a high yield. |
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