Vanadium catalysis system for combined polymerization of ethylene, propylene, and diolefin, and application

Abstract

This invention relates to a vanadium catalyst system for preparing rubber elastomers. This invention introduces an activation promoter into the traditional vanadium catalyst system to form a new active catalyst system, which is composed of vanadium compound, cocatalyst and activation promoter. The vanadium catalyst system can be used in ternary polymerization of ethylene, propylene and diene, and has such advantages as high catalytic activity, low consumption and easy removal of vanadium during post treatment.

Description

technical field [0001] The invention relates to a vanadium catalyst system for preparing rubber elastic body by copolymerization of ethylene, propylene and diene and its application. Background technique [0002] It is a well-known method in the industry that vanadium system Ziegler-Natta catalysts are used for terpolymerization of ethylene, propylene and dienes to prepare rubber elastomers. A representative main catalyst is VOCl 3 ,, VCl 3 ,, VCl 4 ,, V(acac) 3 etc., the other component is a Group I-III organometallic compound (such as an aluminum alkyl). Such V-alkylaluminum systems have played a major role in the synthesis of ethylene / propylene / ethylene norbornene terpolymer (EPDM) elastomers. But at the same time, the above-mentioned vanadium compound has the disadvantage that the activity is not high enough in the terpolymerization process of ethylene, propylene and diene. For this reason, in order to increase the yield, a large amount of main catalyst must be add...

AI Technical Summary

Problems solved by technology

But at the same time, the above-mentioned vanadium compounds have the disadvantage that the activity is not high enough in the process of ternary copolymerization of ethylene, propylene and diene

For this reason, in order to increase the yield, a large amount of main catalyst must be added, which will greatly increase the vanadium content in the polymer, which will cause difficulties in the post-treatment of rubber, and because the catalyst residue content in the separated copolymer is high, so Its use is subject to certain restrictions

In addition, most of these vanadium compounds themselves are sensitive to air, water, acid, alkali, etc., and there are many changes in production, storage and use.

[0003] Japanese patent 1973-71492 uses vanadium oxychloride as the main catalyst, and greatly improves the catalytic efficiency of V-Al catalyst by adding anthraquinone oxides as activators, but the compatibility of anthraquinone oxides is not good; USP4181790 With vanadium compound as the main catalyst and 2,3,4,4-tetrachloro-3-butenoic acid ester as the activator, the activity of ethylene-propylene copolymerization is improved and the gel is reduced, but the main catalyst used is sensitive to air , water sensitive, inconvenient to use; CN85108910 uses vanadium oxychloride as the main catalyst, uses alkylaluminum chloride as a co-catalyst, and simultaneously adds silicon tetrachloride or trichlorofluoromethane to carry out the copolymerization of ethylene and α-olefins, which improves the Copolymerization activity, but the silicon tetrachloride used is easy to cause secondary pollution to the polymer; CN1099395 uses vanadium trichloride as the main catalyst, diethylaluminum chloride as the cocatalyst, and ethyl trichloroacetate as the activator Ethylene-propylene copolymerization, the polymerization activity is obviously improved; US4598132 discloses a vanadium catalyst system containing an ester-based polymer, and the synthesis of EPDM with the system formed by this catalyst and aluminum alkyl only improves the gel problem, and the catalytic efficiency does not increase significantly ; US5122493 mainly solves the problem of molecular weight distribution, by using branched dihydroxyl hydrocarbons, the polymer molecular weight is formed into a narrow distribution, VO (acac) 2 Although the catalyst is insensitive to air, water, etc., the catalyst is insoluble in inert solvents (such as hexane), and it is difficult to use when inert solvents such as hexane are used as polymerization solvents