Urethane-modified novolaks for increasing the steel cord adhesion and rigidity of vulcanized rubber blends

摘要

Urethane-modified novolaks which are prepared by simultaneous reaction of a monohydric or polyhydric phenol (A) with an oxo compound (aldehyde or ketone) (B) and a urethane (C) in the presence of an acidic catalyst (D) at an elevated temperature of 60° to 200° C. and contain no interfering amounts of free starting phenol, and their use as adhesion improvers in rubbers, in particular rubbers containing reinforcing media such as steel cord or textile fibers.