Polyacrylate thickening agents
Liquid emulsion polymers useful as pH responsive thickeners for aqueous systems
Polymeric thickeners and their production Patent #: 4892916
ApplicationNo. 648571 filed on 01/31/1991
US 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 groups
ExaminersPrimary: Schofer, Joseph L.
Assistant: Zitomer, Fred
Attorney, Agent or Firm
International ClassesC08F 020/06
Foreign Application Priority Data1989-07-29 DE
AbstractA 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.