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AssigneesSumitomo Chemical Company, Limited, Toyota Jidosha Kabushiki Kaisha
InventorsManabu Hirakawa, Kenichi Ohkawa, Teruhiko Doi, Tetsuya Hisayama, Yuichi Miyake, Takeyoshi Nishio
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A high rigidity ethylene-propylene block copolymer which is composed of (I) a crystalline polypropylene portion and (II) an ethylene-propylene random copolymer portion, and in which the crystalline polypropylene portion (I) has a Q value of not more than 5 which is the weight average molecular weight (Mw)/number average molecular weight (Mn) ratio obtained by a gel permeation chromatography (GPC) method, an isotactic pentad fraction of not less than 0.98 as calculated from 13C-NMR, and an intrinsic viscosity of 0.6 to 0.88 dl/g as measured at 135° C. in tetralin; the ethylene-propylene random copolymer portion (II) has an intrinsic viscosity of 4.0 to 6.0 dl/g as measured at 135° C. in tetralin and an ethylene/propylene ratio of 25/75 to 35/65 by weight; and when the total of the above polymers ((I)+(II)) is taken as 100% by weight, the content of the ethylene-propylene random copolymer portion (II) is 8 to 22% by weight, and a process for producing the same.
A high rigidity ethylene-propylene block copolymer having a melt flow index (MI) as measured at 230° C. under a load of 2.16 kg of not less than 60 g/10 minutes and which is composed of (I) a crystalline polypropylene portion and (II) an ethylene-propylene random copolymer portion, and in which the crystalline polypropylene portion (I) has a Q value of not more than 5 which is the weight average molecular weight (Mw)/number average molecular weight (Mn) ratio obtained by gel permeation chromatography, an isotactic pentad fraction of not less than 0.98 as calculated from 13C-NMR, and an intrinsic viscosity of 0.6 to 0.88 dl/g as measured at 135° C. in tetralin;
A process for producing a high rigidity ethylene-propylene block copolymer which comprises effecting reaction for producing (I) a crystalline polypropylene portion using a solid catalyst comprising, as the essential components, magnesium, titanium, a halogen and an aluminum compound and subsequently effecting reaction for producing (II) an ethylene-propylene random copolymer portion in the same reactor or a second reactor, comprising controlling the reactor conditions so that the crystalline polypropylene portion (I) has a Q value of not more than 5 which is the weight average molecular weight (Mw)/number average molecular weight (Mn) ratio obtained by gel permeation chromatography, an isotactic pentad fraction of not less than 0.98 as calculated from 13C-NMR and an intrinsic viscosity of 0.6 to 0.88 dl/g as measured at 135° C. in tetralin;
Dependencies are inferred from the claim text.