Olefin polymerization catalyst component as well as preparation method and catalyst thereof

Abstract

The invention discloses an olefin polymerization or copolymerization catalyst component as well as a preparation method and application thereof. The catalyst component is prepared through the following steps: (1) enabling a magnesium compound, an organic epoxy compound and an organic phosphorus compound to be in contact with each other in a solvent to form a uniform solution; (2) with the existence of a mixed type assistant precipitation agent, enabling the uniform solution and a titanium compound to be in contact with each other to obtain a mixture; (3) enabling the mixture obtained in the step (2) and an electron donor compound to be in contact with each other, and obtaining the olefin polymerization titaniferous catalyst component through filtering, washing and drying. The olefin polymerization or copolymerization catalyst component has high catalytic activity and slow activity attenuation when being applied to propylene polymerization and copolymerization.

Description

technical field [0001] The invention relates to a catalyst component for olefin polymerization or copolymerization, its preparation method, and its application in olefin polymerization or copolymerization. Background technique [0002] In the late 1970s, companies such as Mitsui Petrochemical Corporation of Japan and Monai of the United States successfully developed titanium-magnesium high-efficiency carrier catalysts with magnesium chloride as the carrier. Because the carrier was used to improve the utilization rate of the active center of the titanium atom, the catalytic activity was improved. It is much higher than conventional catalysts and simplifies the polymerization process, so the world's polyolefin industry has developed rapidly. Conventional methods for preparing highly active supported catalysts are generally co-grinding, grinding and impregnating, spraying carrier forming and high-speed stirring carrier forming, etc. The main disadvantage of the catalyst obtain...

AI Technical Summary

Problems solved by technology

When the catalyst system is used for propylene polymerization, the obtained polymer has high isotacticity and high apparent density, but the catalyst activity is not high

[0004] The technology of forming the support in the above two ways to further prepare catalyst components has developed to a certain extent, mainly in the development of internal electron donors, such as diethers and succinates developed by BASELL, which are used to improve catalyst activity, Improve the hydrogen regulation performance of the catalyst, increase the molecular weight distribution of the product to improve the processing performance, but the increase in catalyst activity is mainly in the early stage of the polymerization reaction, and the activity decays quickly, so because the high activity in the early stage is not conducive to polymer production control, the production of copolymerization When using propylene, there are problems such as insufficient activity in the later stage, and the production process of this type of internal electron donor is generally complicated and the production cost is high, so the production cost of the catalyst is correspondingly high

[0005] Chinese patent CN1453298A discloses a class of glycol ester compounds containing a special structure as electron donors. The use of such electron donors can not only improve the activity of the catalyst, but also significantly broaden the molecular weight distribution of the obtained propylene polymer, but the catalyst activity is limited. The improvement is also mainly in the early stage of the polymerization reaction, and the activity decays quickly. At the same time, the synthesis and purification process of this type of diol ester compound is complicated, which makes the catalyst production cost higher.

[0006] Generally speaking, there are many technologies to improve catalyst activity in the prior art, but the improvement of catalyst activity is usually accompanied by the acceleration of activity decay, which has a negative impact on the application of catalysts.