Copolymer acting as thickening agent for aqueous preparations having a pH above 5.5, a method for its preparation and its use as a thickening agent
Patent 5086142 Issued on February 4, 1992. Estimated Expiration Date: 
January 31, 2011. 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 31, 2011. 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 ReferencesPolyacrylate thickening agents Liquid emulsion polymers useful as pH responsive thickeners for aqueous systems Polymeric thickeners and their production Patent #: 4892916 InventorsAssigneeApplicationNo. 648571 filed on 01/31/1991US Classes:526/318, Carboxylic acid contains ester group526/258, From monomer containing nitrogen atom as part of a heterocyclic ring526/260, 5- or 6-membered nitrogen ring compound having at least one oxygen in the ring526/313, From phenol, phenol ether, or inorganic phenolate monomer526/317.1, From carboxylic acid monomer526/318.2, Carboxylic acid contains two or more carboxyl groups526/318.41, Monomer contains chalcogen other than in C(=O)-O- chalcogen in any monomer)526/318.5, With chalcogen containing monomer, e.g., additional carboxyl monomer, etc.526/329.6, Additional monomer contains an ether group526/333Plural ether groupsExaminersPrimary: Schofer, Joseph L.Assistant: Zitomer, Fred Attorney, Agent or FirmInternational ClassesC08F 020/06C08F 026/08 C08F 116/12 Foreign Application Priority Data1989-07-29 DEAbstractA copolymer is disclosed which acts as a thickening agent for aqueous preparations having a pH of more than 5.5. The copolymer is obtainable by emulsion polymerization in an aqueous medium, at a pH of 2.5 to 5, in the presence of an initiator forming free radicals, at a temperature of 60° to 95° C. of10 to 50% by weight of acrylic or methacrylic acid,25 to 75% by weight of a nonionic vinyl monomer and2 to 50% by weight of a macromonomer of the formulaCH2 =CR--CH2 --O--(Cn H2n O)a (Cm H2m O)b (Cp H2p O)c HwhereinR is H or CH3n, p are the same or different and in each case are 2 or 3, with the proviso that n and p have a value of not more than 2.3 in the average molecule,m=a whole number from 12 to 18a=10 to 100,b=2 to 10,c=0 to 10 andwherein the sum of the monomers amounts to 100% by weight. | |
