Catalyst used for vinyl polymerization and preparation method thereof

Abstract

The invention relates to a catalyst used for vinyl polymerization and a preparation method thereof. The nickelic solid catalyst component is prepared through the following steps: firstly reacting magnesium halide with an organic epoxy compound, an organic phosphorous compound and organic alcohol, thus forming a homogeneous solution; mixing the homogeneous solution with metallic nickel powder; and then reacting with a mixed solution of transition metal titanic halide or derivatives thereof. In the preparation process, an electron donor can be added so as to improve the performance; the catalyst shows high activity and hydrogen regulation sensibility when used for vinyl polymerization; and the added metallic nickel powder is used as a crystal nucleus, thereby being beneficial to the separation of the solid catalyst. The method is favorable for settling out a catalyst mother solution system and is capable of obviously shortening the washing and filtering time of the catalyst, thereby obviously shortening the preparation period of the catalyst.

Description

field of invention [0001] The present invention relates to a catalyst for ethylene polymerization and its preparation method. Background of the invention [0002] Since its invention in the 1930s, polyethylene has been widely used in industry, agriculture, packaging and daily industry due to its abundant raw materials and excellent product performance. occupy a pivotal position in the [0003] During the development of polyethylene, the research on catalysts has always been the core of polyethylene synthesis research, and plays an important role in the synthesis and production of polyethylene. Before the 1980s, the focus of polyethylene catalyst research was on the pursuit of catalyst efficiency. After nearly 30 years of hard work, the catalytic efficiency of polyethylene catalysts has increased by orders of magnitude, thereby simplifying the production process of polyolefins and reducing energy and material consumption. The traditional Z-N catalyst started from the classi...

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Problems solved by technology

[0007] Although the catalyst systems of the above two patents have good performance for olefin polymerization, the former is more inclined to propylene polymerization, and the latter is more inclined to ethylene polymerization, but in order to obtain catalyst solids in the preparation process of the above two catalyst systems, both The method of adding a precipitation aid is adopted. The more effective precipitation aid is one of organic acid anhydrides, organic acids, ethers, and ketones. Especially when phthalic anhydride is used as a precipitation aid, the effect is better. The method is Phthalic anhydride must be completely dissolved in the mixed solvent system first, and then cooled and mixed with the titanium compound. During the mixing process, the catalyst solid grows from scratch in the mother liquor system and gradually aggregates and grows. In order to obtain a good catalyst particle shape, therefore It is necessary to strictly control the mixing speed and reaction temperature of the system, and generally require a long time for washing and filtering, so the use of this type of precipitation aid prolongs the preparation period of the catalyst accordingly

In addition, the above-mentioned precipitation aid system is relatively toxic and requires high operating conditions

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