Modified phenolic resin with increased toughness, storability and adhesion - obtd. by mixing phenoxy resin with phenol, then acid catalyst and finally resol, useful in coating compsn., adhesive and prodn. of fibre-reinforced composites

摘要

The modified phenolic resin, reinforced (hardened) by a phenoxy resin, is claimed and is obtd. by (a) mixing a phenoxy resin (I) with Mw = 10000-1000000 and a phenol in (1.5-1):1 wt. ratio at elevated temp. to form a sticky mixt. (A); (b) mixing this mixt. with an acid catalyst to form a viscous mixt. (B) with relative low viscosity cf. (A); and (c) mixing (B) with a resol-type phenolic resin (II) contg. 60-75 wt.% solids and 5-10 wt.% free aldehyde. The amts. used are 3-25 wt.% (I) and 2-10 wt.% acid catalyst w.r.t. (II).