FIELD: chemistry.
SUBSTANCE: phenol-formaldehyde novolac resin can be used as binding substance in foundry, particularly as a coating for moulding sand for cast cladding and sand cores, or for producing resin-coated proppants in oil and gas extraction processes. Binding composition of a solid novolac resin, having low concentration of free phenol, is obtained via distillation of residual phenol from molten novolac resin and replacing the phenol part with a solvent having volatility which is equal to or less than that of phenol.
EFFECT: obtaining ecologically clean resin which retains its properties as a binder.
18 cl, 2 tbl, 2 ex
