METHOD FOR PRODUCTION OF WATER SOLUBLE ACETONE-FORMALDEHYDE RESIN Russian patent published in 1997 - IPC

FIELD: drilling of wells, ceramic industry, production of polymer concrete and foamed plastics. SUBSTANCE: desired water soluble acetone-formaldehyde resin is prepared by condensation of acetone with formaldehyde, the process is carried out by heating in the presence of alkali catalyst. Said catalyst is added in two steps. Initially portion of catalyst is added till pH of medium is 9.5-11.5. Then residual portion of catalyst is uninterrupted added to maintain constant pH of the medium. At the end on the process melamine is added (its quantity being 1.0-20.0 mass parts per 100 mass parts of acetone). Content of free formaldehyde in desired resin is 0.13-0.52 %. EFFECT: improved efficiency.