Supported single metallocene catalyst used for ethylene polymerization

Abstract

The invention relates to a supported single metallocene catalyst used for ethylene polymerization and a preparation method thereof. The catalyst comprises a single metallocene compound, a chlorinated alkyl silicon modifier, a halogenated alkyl magnesium modifier, alkyl aluminoxane and a silica gel carrier reaction product; the preparation method comprises the following steps: 1) preparation of a chlorinated hydroxyl silicon modified silica gel carrier, 2) preparation of a halogenated alkyl magnesium modified silica gel carrier, 3)preparation of an alkyl aluminoxane modified silica gel carrier, and 4)preparation of the silica gel 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 silica gel carrier is simple, the obtained supported catalyst particles have good morphology and have adjustable size.

Description

technical field [0001] The invention relates to a preparation method of a modified silica gel supported mono-metallocene catalyst and the application of the obtained catalyst in olefin polymerization. technical background [0002] The development and application of a single metallocene catalyst is another major breakthrough in the field of olefin polymerization catalysts after the traditional Ziegler-Natta catalyst, 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 The mo...

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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 the loading of single metallocenes, among which the catalysts using spherical magnesium chloride (containing alcohol) to support single metallocenes have good particle morphology, such as PCT Int.Appl.99 / 21898; US6,455,647; J.Mol .Catal.A2002,188,123; PCT Int.APP1.2004 / 078804, but the carrier contains alcohol, water, alkoxy and other components, and the preparation of the carrier is complicated; while Si0 2 CN1174849; CN1356343; US4,808,561; US5,026,797; US5,763,543; , a large amount of methylalumoxane must still be introduced during the polymerization process, the above shortcomings limit the industrial application of silica gel-supported single metallocene catalysts

There are also reports in the literature that a carrier containing magnesium chloride, silica gel, etc. is used to support a single metallocene (Polymer International, 51: 417-423, 2002; US5962360; CN102336855A), but the activity is very low, and a large amount of MAO needs to be added during polymerization

The above disadvantages limit the industrial application of silica-supported monometallocene catalysts

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