초록 ▼

Propylene resin beads for molding expansion molded articles having improved high temperature resistance include as base resin metallocene-catalyzed copolymers of propylene with at least one or more of ethylene and .varies.-olefins of 4 to 20 carbon atoms. The metallocene-catalyzed propylene copolyme

Propylene resin beads for molding expansion molded articles having improved high temperature resistance include as base resin metallocene-catalyzed copolymers of propylene with at least one or more of ethylene and .varies.-olefins of 4 to 20 carbon atoms. The metallocene-catalyzed propylene copolymers are isotactic random copolymers characterized by a melting point higher than 140.degree. C. to 160.degree. C. and a melt flow rate (MFR) of not higher than 12 g/10 minutes, especially, 0.5 to 12 g/10 minutes. Expansion molded articles produced by expansion molding the expanded beads have a high temperature degree of deflection which is lower than that of metallocene-catalyzed propylene homopolymers and lower than that of Ziegler-Natta-catalyzed random propylene copolymers having the same comonomers and melting point.

대표청구항 ▼

[ What is claimed is:] [1.]1. Expanded propylene resin beads which comprise, as a base resin, more than 50% by weight of isotactic random propylene copolymer resin obtained by copolymerizing propylene and at least one comonomer selected from the group consisting of ethylene and .alpha.-olefins havin

[ What is claimed is:] [1.]1. Expanded propylene resin beads which comprise, as a base resin, more than 50% by weight of isotactic random propylene copolymer resin obtained by copolymerizing propylene and at least one comonomer selected from the group consisting of ethylene and .alpha.-olefins having four or more carbon atoms, in the presence of a metallocene polymerization catalyst, wherein said isotactic random propylene copolymer resin has a melting point in the range of from 141.degree. C. to 160.degree. C. and a melt flow rate of not more than 12 g/10 minutes.