Rare earth catalyst for polymerization of butadiene, and preparation and application methods thereof

Abstract

The invention relates to a rare earth catalyst for polymerization of butadiene, and preparation and application methods thereof. The rare earth catalyst comprises the following compositions: A) rare earth organic carboxylic acid compound, B) alkyl aluminum hydride and C) chlorinated aluminum alkyl and aromatic ester compound, wherein the mass ratio of the A:B:C is 1:(10-45):(1-3). The catalyst prepared by taking the chlorinated aluminum alkyl and aromatic ester compound as an activating agent has high activity and good stability, and can be kept for more than 180 days at room temperature, the molecular weight distribution index of the synthesized polybutadiene rubber is controllable and can achieve 1.71-2.74, the polymerized product can achieve by more than 95%, the cis-1,4-structure unit content is greater than 95wt%, and the mooney viscosity ML 100 DEG C 1+4 is equal to 35-79.

Description

technical field [0001] The invention relates to a rare earth catalyst for butadiene polymerization and its preparation and application method. Background technique [0002] The polymer obtained by polymerizing butadiene under the action of a rare earth catalyst has a regular molecular structure and a high cis content, and is especially suitable for the preparation of high-performance tires. The rare earth catalyst is usually composed of the main catalyst rare earth salt, the catalyst organoaluminum compound and the third component compound that can release halogen atoms. Such as US4444903 provides a kind of by neodymium tributoxide (NdOC 4 h 9 ), diisobutylaluminum hydride and chlorobenzene to form a catalyst system for the copolymerization catalyst of butadiene and isoprene, the monomer conversion rate obtained as a result of butyl rubber is 47.14%, and the molecular weight distribution is 2.87; CN1840552A discloses A rare earth catalyst system for the polymerization of ...

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Problems solved by technology

Such as US4444903 provides a kind of by neodymium tributoxide (NdOC 4 h 9 ), diisobutylaluminum hydride and chlorobenzene to form a catalyst system for the copolymerization catalyst of butadiene and isoprene, the monomer conversion rate obtained as a result of butyl rubber is 47.14%, and the molecular weight distribution is 2.87; CN1840552A discloses A rare earth catalyst system for the polymerization of conjugated dienes, the third component is chloroalkane, and the fourth component is conjugated diene and organic acid; in addition, the third component of the catalyst disclosed in CN1347923A is chlorosilane, and the fourth component is chlorosilane. The four components are conjugated dienes. Most of these rare earth catalysts are heterogeneous or semi-homogeneous catalytic systems, or they are easy to change from homogeneous to heterogeneous after being placed. Therefore, the molecular weight, distribution, and monomer conversion of products in the reaction process rate is difficult to control

US Pat 5686371 discloses a catalyst system, which consists of 1) rare earth compound, 2) organoaluminum compound, 3) silicon chloride or organosilicon chloride, the activity of the catalyst is 810000g-PB / mol-Nd, which can be prepared High cis and narrow polybutadiene, but not very reactive

In addition, the patent CN1295087A discloses a rare earth catalyst for the polymerization of diolefins improved by aromatics. In addition to producing high-performance polyolefin products, it also effectively improves the catalyst activity, but the added aromatics such as benzene and toluene are not easy to separate from the reaction solvent.

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