PURPOSE: To provide a sealer having rubber elasticity, low cost, and low stickiness, and well suited as sealers for such as gaskets or window frame seals, by mixing a methacrylate crosslinker with a non-rigid polyvinyl chloride and irradiating with electron beam at above a specific dose.

CONSTITUTION: About 5W20pts. methacrylate crosslinker selected from a polyethylene glycol dimethacrylate of formula I (wherein n is 1W14), trimethylolethane trimethacrylate of formula II, allyl methacrylate of formula III, etc. is mixed with 100pts. non-right polyvinyl chloride. The mixture is roll-milled, molded into a desired shape, and then irradiated with electron beams at a dose of 5 Mrad or above by an electron irradiation unit to yield the intended sealer. The resulting sealer has rubber elasticity and little or no stickiness to metals, glass, etc. even when pressure is applied for over a long period at a relatively high temp.