Polar group-containing cyclized rubber and a manufacturing method thereof

The present invention is directed to polypropylene, to provide a significantly polar group-containing cyclized rubber and a manufacturing method thereof capable of improving the adhesion between the molded body and the coating material consisting of non-polar polymers such as polyethylene main purpose . To achieve the above object, the present invention is obtained by cyclizing a conjugated diene polymer having a polar group into the polymer chain end, having a polar group at the terminal of the polymer chain, the weight average molecular weight of 1, providing a polar group-containing cyclized rubber is 000～1,000,000.