Sovrez 72 P-t-butyl-phenol formaldehyde novolak Sovereign Chemical Tackifier >> Phenolic Rubber - Elastomer (Chloroprene, Butyl …) ADHESIVE High performance tackifying resin. Confers an excellent tack to green compounds based on synthetic or natural rubber. It is particularly suited for EPDM and nitrile rubber applications High performance novolak tackifying resin. Confers a very good tack to green compounds based on synthetic or natural rubber. Suits for EPDM and nitrile rubber applications.