Preparation of aqueous solutions of polyacrylamides
Patent 4069161 Issued on January 17, 1978. Estimated Expiration Date: 
January 17, 1995. 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.
January 17, 1995. 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 2166074 3039529 3402137 3455714 3731414 3743018 3850838 InventorApplicationNo. 05/482811 filed on 06/24/1974US Classes:507/225, Nitrogen is attached directly or indirectly to the acrylic acid monomer or derivative by nonionic bonding (e.g., acrylamide, acrylonitrile, etc.)166/275, Injected fluid comprises water and material other than inorganic gas507/936, Flooding the formation524/548, From heterocyclic monomer524/555, From nitrogen-containing monomer other than acrylonitrile or methacrylonitrile524/564, Interpolymerized with diverse carboxylic acid ester or with carboxylic acid reactant528/481, Treating at O Deg C (32 Deg F) or below, or at 200 Deg C (392 Deg F) or above528/502FShearing to change polymer particle size or to change polymer propertiesExaminersPrimary: Guynn, Herbert B.AbstractPolymer gel, e.g. polyacrylamide gel, is chilled until frozen and is ground up in a mill. The frozen particles of the polymer gel are then dissolved in water to form an aqueous solution having good efficiency in the recovery of petroleum from formations. |
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