| abstract |
This invention relates to a thixotropic thickening agent and to a process for preparing the same. Such thixotropic thickening agents are particularly useful for thickening water reducible coatings. The thixotropic thickening agents of this invention are copolymers which are comprised of repeat units which are derived from methacrylic acid monomer, ethylacrylate monomer, and a water soluble crosslinking agent. The water soluble crosslinking agents which can be used include ethylene glycol dimethacrylate and alkylene bisacrylamides, such as N,N'-methylene bisacrylamide. A neutralized two weight percent aqueous solution of the thixotropic thickening agents of this invention will have a Brookfield RVT viscosity as measured at 50 rpm using a number 3 spindle within the range of 50 to 2000 centipoise (cps). |