METHOD FOR PRODUCTION OF CYCLOHEXANON-FORMALDEHYDE RESIN Russian patent published in 1997 - IPC

FIELD: production of paint and varnish materials. SUBSTANCE: cyclohexanon-formaldehyde resins are prepared by polycondensation of cyclohexanon-containing reagent with aqueous solution of formaldehyde, molar ratio of cyclohexanon and formaldehyde is 1:1.4. Alcohol fraction of production of caprolactam according to oxidation scheme is used as said cyclohexanon-containing reagent. The process is carried out within 1 h at 90-95 C in the presence of sodium hydroxide being used as alkaline catalyst, molar ratio of sodium hydroxide and cyclohexanon being (1-2):100. When polycondensation is finished then water is added, its quantity being 30-100 % of mass of alcohols and azeotropic distillation of solvents takes place at atmospheric pressure and at temperature not higher than 100 C. Aqueous layer is poured out, resin is washed by small amount of hot water, cooled and then dried at 80 C and at 50 mm Hg pressure. Thus prepared resin is transparent and colorless compound, its softening temperature being 97-99 C. EFFECT: improved heat control of the process, improved efficiency. 2 cl