Synthesis method of bimodal-distribution ethylene-alpha-alkene-non-conjugated dialkene random copolymer

Abstract

The invention relates to a synthesis method of a bimodal-distribution ethylene-alpha-alkene-non-conjugated dialkene random copolymer. The method comprises the following steps: a high-molecular weight part ethylene-propylene copolymer is synthesized from ethylene, propylene and hydrogen (the mol ratio is 1:1.0-3.0:0.15-0.30) and ethidene norbornylene 2-5 mL / L hexane; a low-molecular weight part ethylene-propylene copolymer is synthesized from the ethylene, the propylene and the hydrogen (the mol ratio is 1:3.0-4.5:0.9-2.0) and ethidene norbornylene 8-12 mL / L hexane; the main catalyst is soluble vanadium complex, and the cocatalyst is ethylaluminium sesquichloride; the mol ratio of Al to V is 1-100; the activating agent for the low-molecular weight part is ethyl trichloroacetate; and the mass ratio of the high-molecular weight part ethylene-propylene copolymer to the low-molecular weight part ethylene-propylene copolymer is 80 / 20-40 / 60. The copolymer has the advantages of high Mooney viscosity and moderate molecular weight distribution, and can be used for processing rubber for automobile gland strips.

Description

technical field [0001] The invention relates to a method for synthesizing a bimodal distribution ethylene-alpha-olefin-non-conjugated diene random copolymer. The bimodal distribution ethylene-alpha-olefin-non-conjugated diene random copolymer synthesis method uses a soluble vanadium catalyst as the main catalyst, an alkylaluminum halide as a co-catalyst, and is completed in the form of solution polymerization by blending high and low molecular weights , so that the synthesized copolymer rubber has excellent processing performance. Background technique [0002] It is a well-known method in the industry that vanadium system Ziegler-Natta catalysts are used for ternary copolymerization of ethylene, α-olefins, and non-conjugated dienes to prepare rubber elastomers. Representative main catalysts such as VOCl 3 ,, VCl 3 ,, VCl 4 ,, V(acac) 3 etc., the other component is the I-III group organometallic compound (such as alkylaluminum), these V-alkylaluminum systems play the rol...

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Problems solved by technology

[0003] Japanese Open Patent Gazette No. 57-131212 uses ethylene, α-olefin and non-conjugated diene as polymerized monomers, uses alkylaluminum chloride as cocatalyst, and vanadyl trichloride as main catalyst, and synthesizes a compound with An ethylene-propylene copolymer with excellent processability, but the main catalyst used is vanadyl trichloride; Japanese Patent Publication No. 61-264035 uses modified vanadium as the main catalyst and alkyl aluminum chloride as a cocatalyst, and ethylene, α- Olefins and non-conjugated diolefins are polymerized monomers. A single-pot polymerization process is used to synthesize ethylene-propylene copolymers with bimodal distribution. The modified ligands used are secondary alcohols. The adjustability of the combined monomer is not as good as that of the double-pot parallel polymerization blending process; the Japanese Patent Publication No. 59-14497 uses modified vanadium as the main catalyst and mixed alkyl aluminum as the co-catalyst, and adopts the double-pot parallel process. Ethylene-propylene copolymer with excellent vulcanization performance. The propylene content of the high molecular weight part and the low molecular weight part of the copolymer is basically the same, and the iodine value of the high molecular weight part is 4-5 times that of the low molecular weight part.

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