Hydrochloric Acid → Resorcinol-formaldehyde resin

Participants

Reaction Conditions

Reaction Steps

After 2660 g of water, 1710 g of calcium chloride, 738 g of resorcinol, and 300 g of methyl ethyl ketone were placed in a 5 L flask made of glass and dissolved at 60° C., 9 g of 35% hydrochloric acid was charged into the reaction vessel. While the reaction system was cooled to 50° C. and maintained at 50° C., 326 g of 37% formalin was added dropwise over a period of 45 minutes and, after the completion of the dropwise addition, the mixture was further stirred at 50° C. for 1 hour to cause a liquid-liquid heterogeneous reaction to proceed. Thereafter, 27 g of 37% formalin was added dropwise over a period of 45 minutes and, after the completion of the dropwise addition, the mixture was further stirred at 50° C. for 1 hour to cause a liquid-liquid heterogeneous reaction to proceed. While the reaction system is maintained at the same temperature, it was allowed to stand and separate into two layers, and then an underlying aqueous phase was drawn off. The organic phase was diluted with 1000 g of methyl ethyl ketone and 500 g of water was added thereto. Furthermore, while maintaining the same temperature, the reaction system was stirred for 1 hour and, after allowing to stand, separated into two layers and then the aqueous layer was drawn off to obtain a methyl ethyl ketone solution of a resorcinol-formalin resin. The solution was again diluted with 1000 g of methyl ethyl ketone and distillation was conducted at the azeotropic temperature of water and methyl ethyl ketone to remove water. Then, the mixture was cooled to room temperature and filtrated to obtain a methyl ethyl ketone solution of a resorcinol-formalin resin. The resulting methyl ethyl ketone solution of the resorcinol-formalin resin was again placed in the reaction vessel and, after the addition of eater, distillation was conducted at the azeotropic temperature to remove methyl ethyl ketone and reduce the water content, whereby 1683 g of an objective aqueous resorcinol-formalin resin solution having a solid content of about 50% and a moderate flowability was obtained. The aqueous resorcinol-formalin resin solution having a solid content of about 50% is a resorcinol-formalin resin containing no inorganic salts and reduced contents of the resorcinol monomer and resorcinol pentanuclear and higher nuclear bodies.

Provenance & Evidence