SP 25 Phenolic Schenectady International Tackifier >> Phenolic Rubber - Elastomer (Chloroprene, Butyl …) ADHESIVE SP-25 is a thermoplastic, oil-soluble phenolic resin. This resin has found usage as a tackifier for nitrile (NBR) elastomers. Thermoplastic, oil-soluble phenolic resin. Used as a tackifier for nitrile rubber elastomers.