Casting of articles from compositions containing calcined gypsum and Portland cement
Patent 4202857 Issued on May 13, 1980. Estimated Expiration Date: 
July 18, 1998. 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.
July 18, 1998. 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 References 3582376 3666703 3852081 Cementious composition for use in preparing pointing compounds or mortar compounds Low porosity aggregate-containing cement composition and process for producing same Casting of articles containing calcined gypsum Patent #: 4067939 InventorAssigneeApplicationNo. 05/925670 filed on 07/18/1978US Classes:264/333, Inorganic hydraulic settable material shaping106/733, Titanium, vanadium, chromium, molybdenum, tungsten, manganese, iron, copper, zinc, tin or lead compound containing (Ti, V, Cr, Mo, W, Mn, Fe, Cu, Zn, Sn, Pb)106/735, Calcium sulfate specified (e.g., gypsum, anhydrite, plaster of Paris, etc.)264/86REMOVAL OF LIQUID COMPONENT OR CARRIER THROUGH POROUS MOLD SURFACEExaminersPrimary: Arnold, Donald J.Attorney, Agent or FirmInternational ClassesC04B 28/00 (20060101)C04B 28/14 (20060101) Foreign Application Priority Data1977-07-19 GBAbstractAn article is cast from a composition comprising a binding agent containing, by weight, from 90% to 10% calcined gypsum and from 10% to 90% Portland cement mixed with water to produce a fluid mixture which is caused to flow into a mould or other supporting device and is there allowed to set. To increase the durability of the cast article in the presence of moisture, sodium carbonate in an amount up to 5% by weight of the dry weight of the cement is added to the composition. The sodium carbonate is preferably present in an amount between 0.1% and 0.5% of the dry weight of the cement and the composition preferably also contains an acrylic resin emulsion in an amount from 0.25% to 4% of the dry weight of the gypsum and cement in the composition and a pigment such as iron oxide, titanium oxide or cobalt oxide in an amount from 0.25% to 4% by weight of the dry weight of the gypsum and cement in the composition. | |
