PROCESS FOR PRODUCING HYDROGENATED UNSATURATED RING-CONTAINING HYDROCARBON POLYMER

A process for producing a hydrogenation product of a ring-containing unsaturated hydrocarbon polymer, which product is low in the content of the heterogeneous catalyst used. A ring-containing unsaturated hydrocarbon polymer is subjected to a hydrogenation reaction under hydrogen pressure in the presence of a heterogeneous catalyst in an inert solvent; a suspension containing the hydrogenated polymer obtained is fed into a hydro-cyclone by the hydrogen pressure applied to the reaction system; in the cyclone, the heterogeneous catalyst is separated and recovered and a hydrogenated polymer low in heterogeneous catalyst content is produced.