Supported single metallocene catalyst for ethylene polymerization

Abstract

The invention discloses a supported single metallocene catalyst used for vinyl polymerization and a preparation method thereof. The catalyst comprises a single metallocene compound, a chlorinated alkyl silicon modifier, alkyl aluminoxane and a magnesium chloride carrier reaction product; the preparation method comprises the following steps: 1) preparation of a chlorinated alkyl silicon modified magnesium chloride carrier, 2) preparation of an alkyl aluminoxane modified magnesium chloride carrier, and 3)preparation of a magnesium chloride supported single metallocene catalyst; and the obtained single metallocene catalyst has high polymerization activity for catalyzing vinyl polymerization or copolymerization. The preparation method of the magnesium chloride carrier is simple, and the obtained supported catalyst particles have good morphology with adjustable size. The obtained supported single metallocene catalyst is capable of catalyzing copolymerization of ethylene and alpha-alkene, the copolymerization activity is high, the obtained resin powder has good particle morphology, bulk density is high, and the single metallocene catalyst is suitable for the polymerization technology of a slurry method and a gas phase method.

Description

technical field [0001] The invention relates to a modified magnesium chloride supported monometallocene catalyst, a preparation method, and an application of the obtained catalyst in olefin polymerization. technical background [0002] The development and application of single metallocene catalysts is another major breakthrough in the field of olefin polymerization catalysts after the traditional Ziegler-Natta catalysts. Especially in the 1980s, Kaminsky and Sinn et al. (Angew.Chem., 1980, 19, 390; Adv Organoment.Chem., 1980, 18, 99) developed a high-efficiency cocatalyst methylaluminoxane (MAO), making the research on single metallocene catalysts enter a stage of rapid development. Because the homogeneous single metallocene catalyst requires a large amount of MAO to achieve high activity, the production cost is high, and the obtained polymer is amorphous, which cannot be used in the widely used slurry method or gas phase polymerization process to overcome the above problems...

AI Technical Summary

Problems solved by technology

Because the homogeneous single metallocene catalyst requires a large amount of MAO to achieve high activity, the production cost is high, and the obtained polymer is amorphous, which cannot be used in the widely used slurry method or gas phase polymerization process to overcome the above problems The most effective way is to support the soluble mono-metallocene catalyst

[0003] At present, there are a lot of research reports on single metallocene loading, among which SiO 2 CN1174848; CN1174849; CN1356343; US4,808,561; US5,026,797; US5,763,543; .Appl.99 / 21898; US6,455,647; J.Mol.Catal.A2002,188,123; PCT Int.APP1.2004 / 078804; CN101817892; CN101172988; Poor and uncontrollable; although the use of spherical magnesium chloride (containing alcohol) can ensure that the catalyst loaded with a single metallocene has a good particle shape, the carrier still contains alcohol, water, alkoxy and other components, and the preparation of the carrier is complicated. The above Disadvantages limit the industrial application of MgCl-supported monometallocene catalysts

[0004] There are also literatures that use carriers containing magnesium chloride, silica gel, etc. to load mono-metallocenes (Polymer International, 200251: 417-423; US5962360), but the activity is very low, and a large amount of MAO needs to be added during polymerization

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