HRJ 10420 Para-tertiary octylphenol novolak resin Schenectady International Tackifier >> Alkylphenolic Rubber - Elastomer (Chloroprene, Butyl …) Styrene copolymers Natural rubber (NR) HRJ-10420 is a thermoplastic, unmodified alkylphenolic resin supplied in flake or pastille form. HRJ-10420 is intended for use as a tackifier for natural rubber and synthetic elastomers, including SBR, BR, IIR and IR. Thermoplastic, unmodified alkylphenolic resin. Used as a tackifier for natural rubber and synthetic elastomers, including SBR, BR, IIR and IR.