摘要:
An improvement in the method for producing ethylene polymers by using a catalyst consisting of a combination of a following solid product with an organoaluminum compound is provided.Said solid product (III) is prepared by reacting a trivalent metal halide with a divalent metal compound; reacting the resulting reaction product with a transition metal compound in the form of liquid; reacting the resulting solid product (I) with an aluminum or boron alcoholate; and reacting the resulting solid product (II) again with a transition metal compound in the form of liquid to obtain said solid product (III).Ethylene polymers obtained according to this method have broader molecular weight distributions.
摘要:
A superior high-rigidity and high-melt-viscoelasticity polypropylene for sheets to be post-processed and for blow molding is provided which polypropylene is produced by subjecting propylene to a multi-stage polymerization into polymer portions of two sections in the presence of a specified Ziegler Natta catalyst, the relationship between the intrinsic viscosities of the polymer portions of the respective sections being regulated within a specified range and also the amount ratio of the polymer portions of the respective sections being regulated.
摘要:
An ethylene-propylene block copolymer capable of producing foamed shaped articles having a structure of uniform and fine foams even without adding any other resins, and a process for producing the same are provided, which copolymer consists of a propylene homopolymer portion and an ethylene-propylene (EP) copolymer portion and is characterized in that .circle.1 the former portion is obtained by polymerizing propylene at two stages so that the portion can further consist of a lower molecular weight portion and a higher molecular portion; .circle.2 between the melt flow rates of the resulting block copolymer under a specified load and five times the load, there is a specified relationship; .circle.3 the EP copolymer portion has an ethylene content of 60 to 95% by weight based on this portion; and .circle.4 the block copolymer has an ethylene content of 10 to 40% by weight based on the copolymer.
摘要:
Ethylene can be polymerized or copolymerized by the use of a catalyst prepared by mixing a trivalent metal halide with a metal carbonate or/and a metal hydrogen carbonate, reacting the resulting mixture with a transition metal compound in the presence of an aromatic compound, and activating the resulting solid product with an organoaluminum compound.By substituting said metal carbonate or/and metal hydrogen carbonate for metal salt hydrates, sulfide hydrates, hydroxides or hydroxide hydrates, or metal oxides in our prior art, drawbacks such as dehydrochlorination in the preparation of catalyst or difficulty in removal of catalyst residue from polymer can be overcome while various advantages in our prior art are still maintained.