Crystalline 1-butene polymer composition

Claim 1

A crystalline 1-butene polymer composition comprising (a) a crystalline 1-butene polymer containing a 1-butene component as a main component, and (b) a radical-treated crosslinked crystalline polymer having alpha olefin homopolymer or copolymer consisting of two or more alpha olefins which has (1) a boiling p-xylene-insoluble content of 30% by weight at most and (2) the relation satisfying the following expressions Tc.sup.CL ≧Tc.sup.0 ≧1 wherein Tc CL is the crystallization temperature (°C.) of the radical-treated crystalline olefinic polymer, and Tc 0 is the crystallization temperature of the crystalline olefinic polymer before the radical treatment, and 0.01<(MFR CL )/(MFR°)<100 wherein MFR° (g/10 min) is the melt flow rate of the crystalline polymer before treatment and MFR CL (g/10 min) is the melt flow rate of the crystalline polymer after treatment, and (c) the proportion of the radical-treated crosslinked crystalline polymer (b) being 0.2 to 100 parts by weight per 100 parts by weight of the crystalline 1-butene polymer (a), said treatment being effected in the presence of a cross linking agent and a polymerization initiator, or by irradiating light onto the crystalline polymer in the presence of a photopolymerization initiator.