a process for bonding a thermoplastic ppe - containing polymer and a rubber by covulcanization , comprising the steps of : heating and covulcanizing said ppe - containing polymer and said rubber , wherein said rubber comprises : 100 parts by weight of a mixture comprising 100 - 20 wt . % of an epm rubber and 0 - 80 wt . % of a styrene - butadiene rubber obtained by emulsion polymerization , 100 - 300 parts by weight of loading material , 1 - 10 parts by weight of a peroxidic vulcanization agent , and 0 . 5 - 4 parts by weight of a vulcanization activator , wherein a vulcanization bond is formed between said ppe - containing thermoplastic polymer and said rubber .