Abstract: A rubber compound essentially for use in making conveyor belts on which tacky materials such as oil sands are transported without adhesion, comprising a base rubber such as acrylonitrile-butadiene rubbers, urethane rubbers, acryl rubbers and blends of these rubbers with polybutadiene rubbers, styrene-butadiene rubbers and natural rubbers, and an organic carboxylate such as alkyl oleates and alkyl stearates.

Abstract: A butadiene-acrylonitrile copolymer rubber (NBR) composition can be strongly adhered to a metal material by compounding (A) a halogenated aromatic hydrocarbon having the general formulaR.sub.n.sub.' --(Ar)--CX.sub.m H.sub. 3-m).sub.nOr ##STR1## WHEREIN Ar is benzene nucleus residue or naphthalene nucleus residue, R is a hydrocarbon residue having 1-6 carbon atoms, hydrogen atom or halogen atom, X is halogen atom, m is 1-3, n" is 1-3, when Ar is benzene nucleus residue, n is 1-6 and n' is 0-5 (provided that n+n'.ltoreq.6) and when Ar is naphthalene nucleus residue, n is 1-8 and n' is 0-7 (provided that n+n'.ltoreq.8), and (B) at least one compound selected from the oxides, carbonates, sulfides and hydroxides of metals of groups I, II, IV, V and VIII in the Periodic Table and aluminum hydroxide, to the NBR composition, contacting the resulting rubber composition to the metal material, and vulcanizing the rubber composition to adhere the composition to the metal material.