METHOD OF PRODUCING NOVOLAC PHENOL-FORMALDEHYDE RESIN Russian patent published in 2013 - IPC C08G8/10 C08G8/12 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing novolac phenol-formaldehyde resins for use as modifying additives which intensify resin properties, for adhesion promoters in tyre rubber and industrial rubber articles, as well as other composite materials, e.g. for producing elastomers. The method of production involves condensation of phenol with formaldehyde in the presence of oxalic acid at boiling point of the reaction mixture, further removal of over-resin water by evaporation at atmospheric pressure and raising temperature from 100 to 130°C, creating a vacuum and distilling residual phenol. After removing the over-resin water, 1-10 wt % of a reactive additive based on branched polyatomic phenol and cobalt-containing compounds are added to the molten mass in ratio of (10÷50):(50÷10).

EFFECT: obtaining low-phenol novolac phenol-formaldehyde resins with low viscosity and melting point, having sufficiently high reactivity of the resin in an elastomer matrix.

3 cl, 1 tbl, 1 ex