METHOD FOR PRODUCTION OF WATER-SOLUBLE RESOL PHENOLFORMALDEHYDE RESINS Russian patent published in 1995 - IPC

FIELD: production of wood particle boards. SUBSTANCE: water-soluble resol phenolformaldehyde resin is produced by condensation of phenol, formaldehyde and modifying components in water medium in the presence of sodium hydroxide introduced in two stages. Modifying components is in form of still bottoms of production of diphenylolpropane which presents filtrate formed at the stage of phenol distillation after the second crystallization of diphenylolpropane. Filtrate contains, mas.%: mixture of diphenylolpropane isomers 75-90; phenol 5-20; and water 0.1-5.0. Mass ratios of phenol, still bottoms of diphenylolpropane production, formaldehyde and sodium hydroxide are (50-90):(10-50):(65-77):(-31), respectively. Process is conducted, first, at 85 ± 5^°C for 15 min, then the second portion of sodium hydroxide is introduced and process is continued at 80-85 C for 1 h and 40 min up to obtaining resin with viscosity of 23-25 s and then, resin is cooled. EFFECT: higher efficiency. 2 tbl