FIELD: chemistry.
SUBSTANCE: method of producing liquid resin essentially consisting of phenol-formaldehyde and phenol-formaldehyde-amine condensates, having water dilution at 20°C at least equal to 1000% and content of free formaldehyde of at most 0.1% of the total weight of the liquid, involves reaction of phenol with formaldehyde in molar ratio formaldehyde/phenol greater than 1 in the presence of a basic catalyst, cooling the reaction mixture and adding amine to said reaction mixture during cooling, which reacts with the free formaldehyde and phenol according to a Mannich reaction. Cooling is stopped the moment amine is added and the reaction mixture is held at addition temperature for a period of time varying from 10 to 120 minutes. After cooling, acid is added in amount which is sufficient to achieve pH value of the resin less than 7.
EFFECT: obtaining and using liquid phenol resin with low content of free formaldehyde.
17 cl, 3 ex
