PRODUCTION OF PROPYLENE HOMOPOLYMER

摘要

PROBLEM TO BE SOLVED: To obtain the subject copolymer having a specific melt index, a prescribed relation between a melt tension and an intrinsic viscosity, by using a specific catalyst, obtaining a propylene homopolymer having an intrinsic viscosity in a specified range and successively polymerizing propylene in the presence of the obtained reaction mixture. SOLUTION: (A) A propylene homopolymer having 0.008-0.8 dl/g intrinsic viscosity in tetralin solvent at 135 deg.C is obtained by using (i) an indenyl skeleton- containing transition metal compound of the group 4 of the periodic table and (ii) a polymerization catalyst containing an aluminum oxy compound and an ionic compound. (B) Propylene is successively polymerized in the presence of the obtained reaction mixture to give the objective polymer having a melt index in the range of 0.005-1,000 g/10 minutes and a melt tension MS at 230 deg.C and an intrinsic viscosity [η] in tetralin solvent at 230 deg.C satisfying the formula logMS>=3.17×log[ν]-0.68.