METHOD FOR PRODUCTION OF RESOL PHENOLFORMALDEHYDE RESIN Russian patent published in 1995 - IPC

FIELD: production of laminated materials. SUBSTANCE: resol phenolformaldehyde resin is produced by condensation of phenol with formaldehyde in the presence of triethylamine at mass ratio of components of 100:(50-62): (53-10), respectively. Process is conducted at temperature of boiling of reaction mixture (96-98 C) for 24-45 min. Then, drying is effected under vacuum of 0.72 kg/sq.cm, and it is ended when refraction coefficient reaches 1.58-1.62. Cooled resin is dissolved in alcohol. Produced resin contains 2.0-2.8% of free phenol, 0.7-1.2% of free nonreacted formaldehyde with viscosity of 248.5-312 mPa.s, gel formation time is 89-98 s. Produced on resin basis is textolite-fabric impregnated with resin. EFFECT: lower temperature and reduced time taken for pressing. 3 tbl