To improve waterproof, chlorine resistance, bending resistance, gas transmission resistance, etc., by vulcanized and formed from chlorinated polyethylene component composed of chlorinated polyethylene of a specific chlorine content and hydrotarsite group.

Chlorinated polyethylene used as a major component of a bladder molding is formed by mixing hydrotarsite group with the chlorinated polyethylene having chlorine content of approximately 20-50wt.%. The component is prepared by an arbitrary mix means and vulcanized by a pressure molding, an injection molding, etc., while heated at a prescribed temperature for a prescribed time. This constitution can improve waterproof, bending resistance, gas transmission resistance, weatherability, ozone resistance, etc., especially improve chlorine resistance under high-density chlorine conditions, eliminate surface deterioration, and reduce physical property deterioration in the case of used for a long time.