摘要 |
The present invention relates to novel novolac resins obtained by coupling at least one aromatic compound (A) comprising at least two hydroxyl groups and at least one aldehyde (B) in the presence of an acid catalyst and in the presence of water and/or an organic solvent, followed by a step of alkylating the coupling resin thus obtained with at least one unconjugated diene (C), preferably containing no indene. These novolac resins are advantageously used in vulcanized and crosslinked elastomeric compositions since their viscosity, which is lower than that of the resins of the prior art, allows them to be handled easily. They are also used as adhesion promoters for improving the adhesion of rubber to reinforcing materials such as organic fibres made in particular of rayon, polyesters, polyamides or aramids, and metal cords made of steel, in particular brass steel or galvanized steel. |