Process for producing propylene resin composition

• Main Authors: SANADA TAKASHI, SHIMANO MITSUYOSHI, MORITOMI SATORU
• Format: Patent
• Language: English
• Published: 23.10.2012
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; GENERAL PROCESSES OF COMPOUNDING; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; WORKING-UP

Disclosed are processes for producing polypropylene resin compositions including two or three sorts of propylene-based polymeric materials, the processes including a first step of melt-kneading at least a propylene-α-olefin block copolymer containing a polymer portion composed mainly of propylene and a propylene-α-olefin copolymer portion having a relatively high intrinsic viscosity and a second step of melt-kneading the product of the first step with a propylene-ethylene block copolymer containing a polymer portion composed mainly of propylene and a propylene-ethylene copolymer portion having a relatively low intrinsic viscosity or a polymer portion composed mainly of propylene having a relatively low intrinsic viscosity. In the composition produced by these processes, no or substantially no fish eyes develop.