Mono-active center Ziegler-Natta catalyst for olefinic polymerization

Abstract

The invention relates to a new catalyst for single active central Ziegler-Natta alkene polymerization. Said catalyst takes salicylal containing dentate or substituted salicylal derivatives as electrons, and is prepared by adding pretreated carrier, metallic compound and electrons into magnesium compound / tetrahydrofuran solution. The catalyst can produce ethane homopolymer and copolymer with narrow molecular weight distribution (1.6-3.8) and even comonomer distribution, with high activity and under action of adjuvant catalyst of alkyl aluminium and alkyl aluminoxanes. The ethane polymerization, homopolymerization or combined polymerization of ethane and 1- olefin, ring olefin and polar monomer through slurry method or gas phase method by using said catalyst can be realized.

Description

technical field [0001] The invention relates to a new type of single active center Ziegler-Natta (Ziegler-Natta) olefin polymerization catalyst. The catalyst uses salicylaldehyde or a substituted salicylaldehyde derivative containing a coordination group as an organic electron donor. Under the action of a co-catalyst, the catalyst can be used to catalyze the homopolymerization of ethylene or the copolymerization of ethylene and alpha-olefin to obtain a structure-controllable ethylene polymer. Background technique [0002] With the rapid development of the polyolefin industry, the production of high-performance polyolefin materials has attracted more and more attention. At present, international research believes that the production of high-performance polyolefin materials can be realized in two ways: 1) using Ziegler-Natta catalysts, relying on the improvement of chemical processes; 2) using new single-site catalysts including metallocene catalysts and Non-generic catalyst...

AI Technical Summary

Problems solved by technology

For example, the patent US 5459116 reports a method for preparing a titanium-containing solid catalyst by reacting a magnesium solution containing an ester (having at least one hydroxyl group as an electron donor) with a titanium compound. The catalyst has high catalytic activity, but the molecular weight distribution of the polymer Width (PDI is 7.38~10.04)

Chinese patent CN1510055A reports the support type Ziegler-Natta ethylene polymerization catalyst prepared as electron donor with a small amount of alcohol, only one example provides the molecular weight distribution data of polyethylene, PDI is 4.79, and the activity of catalyst is not high

However, the development and application of these new catalysts are greatly restricted due to the low stability of the main catalyst, difficulty in synthesis, difficulty in storage, need for a large amount of expensive co-catalysts, and difficulty in operating on current polymerization process devices.

[0005] Utilizing Ziegler-Natta catalysts to control the structure and properties of polymers, and obtaining polymers with narrow molecular weight distribution (1.6-3.8) and uniform comonomer distribution with high activity have not been reported yet.

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