RU1836385C - Method for obtaining a bifunctional catalyst for ethylene polymerization - Google Patents

Abstract

SUMMARY OF THE INVENTION: On a pre-activated triisobutylaluminium and diethylethoxyaluminium chromium catalyst taken as a suspension in a hydrocarbon, a nickel-aluminum complex is applied as a solution in a hydrocarbon. The complex has the general formula iso-C / iHgRnNlCJ-A1 (iso-C H9) 2C I where R is butadiene, isoprene, n 3-10. Atomic ratio: chromium (1:20) -1: 1). 3 tab.

Description

The invention relates to metal complex catalysis and a method for producing polyolefins.

Linear PE of low and medium density, which is an ethylene copolymer. Lena with Ј10 mol.% a-olefins. (butene-1, hexene-1), is obtained by copolymerization under the action of catalysts based on transition metal compounds (TI, V, Zr, Cr) M supported on solid Salts or oxides (MgCl2. S102. and others). However, the need to synthesize and isolate comonomers (butene-1, - hexene-1) complicates and increases the cost of the process.

A promising method is the production of In one pot comonomers simultaneously with polymerization, when ethylene oligomerizes to butene-1 and gessen-1, and these oligomerization products immediately enter into copolymerization with ethylene.

For this purpose, bifunctional catalysts containing oligomerizing and polymerizing centers are used, and the activity of the oligomerizing centers must be sufficient to form the required amount of a-olefins

 ...

The aim of the invention is to increase the activity of the catalyst and simplify the process technology.

To achieve the goal, a bifunctional catalyst is prepared by applying soluble nickel-aluminum complexes of the general formula iso-С4Н9НпЫ1С1 A1 (iso-С4Нд) 2С1 to oxide-chromium catalysts where R is butadiene, isoprene, n 3-10, with an atomic ratio of N and Cr (1: 20) - (1: 1),

These complexes receive the interaction of a suspension of NiCfz in hydrocarbon

with оСО 00

with

00

dachs (iso-C4Hd) zA in the presence of a conjugated diene (butadiene, isoprene). The chromium oxide catalyst was pre-activated by treatment with (C2Hs) 2AI (OC2H5), atomically Al / Cr 8. The treated catalyst was suspended in hydrocarbons and the suspension was used to deposit a nickel-aluminum complex. The solvent is then condensed and the resulting bifunctional catalyst dried in. vacuum and stored in a dry atmosphere of Ag.

Preparatory examples. Preparation of a nickel-aluminum complex ..

Example A. A suspension of 1.3 g of NICI2 (0.009 mol) in 57.5 ml of toluene, 4.5 ml of isoprene and 37.5 ml of a solution of (iso-C4He) sA was placed in a reactor in a stream of Ar and stirred for 1 h at 30 ° C. A solution of a nickel-aluminum complex with a concentration of 0.05 mol / L is obtained in 100% yield (according to NICte). The complex contains Ni, AI and diene at a molar ratio of AIKNI 2 and isoprene to N15.

Example B. 1.3 g of NICI2, 100 ml of heptane, 8.2 ml of butadiene and 45 ml of solution (iso-C4Hd) sA1 were placed in a reactor and stirred for 1 h at 30 °. A nickel-aluminum complex with a concentration of 0.045 mol / L containing Ni, AI and diene is obtained in 100% yield (according to NICI2) with a molar ratio of A to Ni 6 and butadiene to NijK) .. S

Obtaining a bifunctional catalyst.

Example 1 “0.33 g of the A-183 oxine-chromium catalyst prepared by applying CrO3 to SI02 containing 0.8% Cr was placed in amplitude, 5 ml of hexane was added and a 0.05 M solution (C2Hs) was added to the suspension 2AI (OC2H5) in hexane at a molar ratio of Al / Cr 8. The suspension is stirred, the solvent is condensed, a fresh portion of hexane is introduced and a solution of the NI-AI complex obtained in Example A is added at molar NI / Cr ratio 1/10. It is maintained at a gradual increase in temperature to 20 ° C until the solution becomes completely discolored, the solvent is condensed, the catalyst is dried in a vacuum and sealed in a vial in a stream of Ar.

Example 2.14t of the reaction product of triphenylsilylchromate (catalyst S-2) with Aerosil A-3.00 containing 0.23% Cr. heated in a tube furnace in a stream of dry air for 12 hours at 450 ° C. Cool in a stream of Ar, transfer to a stirred reactor, add 15 ml of hexane, cool to (-78) ° C, add a solution of (C2H5} 2AI (OC2Hs) at a molar ratio Al / Cr 8 and immediately add a solution NI-Af complex obtained in

Example B, in a molar ratio of NI / Cr - I. With stirring, the temperature is raised to 20 ° C, the suspension is kept until the solution is completely discolored, the solvent is condensed, the catalyst is dried in a vacuum, and the mixture is dispersed in a stream of Am into ampoules (0.3 g), which sealed in a current Ar. Example 3. 0.3 g of the oxide-chromium catalyst OXK-3, prepared by supporting CrO3 on Aerosil A-300, treated with (C2Hs) 2Al (OC2H5) at a molar ratio Af / Cr 8, suspended in 5 ml of hexane, cooled to (-78) ° C. A solution of the NI-AI complex is added. cooked in

5 example A. taken at a molar ratio of Ni / Cr 1/20. maintained at a temperature increase to 20 ° C until the solution is completely discolored, the solvent is condensed, the catalyst is dried in vacuum

0 and stored under dry Ar.

Polymerization of ethylene under the action of the obtained bifunctional catalysts.

The polymerization is carried out in a reactor.

5 for gas phase polymerization with a capacity of 1.5 l, equipped with a magnetic stirrer and a device for breaking ampoules. The reactor is purged with pure ethylene, ethylene and H2 are introduced under partial pressure of 1.0 and 0.1 MPa, respectively, the temperature is raised to 60-80 ° C, (C2H5) 2A1 (OC2H5) or (iso-C4H9) zA1 are introduced, the ampoule is broken with a catalyst and polymerization is carried out for 1 hour. PE is isolated,

5 which is washed with acetone, a stabilizer is added and dried in vacuo. The amount of butene-1 and hexene-1 in the mixture was determined by chromatography. The number of branches in the polymer is set using

0 pc spectra.

Table 1 gives the results of the preparation of a bifunctional catalyst and the polymerization of ethylene, table 2 shows the characteristics of the obtained polymers, and table 3

5 - physical and mechanical characteristics of polymers.

Claims (1)

SUMMARY OF THE INVENTION A method for producing a bifunctional catalyst for the polymerization of ethylene by depositing nickel compounds on chromium catalysts, characterized in that, in order to increase the activity of the catalyst and simplify the process technology, a nickel-aluminum complex hydrocarbon solution of total nickel 5 is used Formulas H30-C4H9RnNICI AI (H30-C4H9) 2CI. where R is butadiene, isoprene, n 3-10. chromium catalysts are pre-activated with diethylethoxy aluminum or triisobutylaluminum and use a: a suspension in a hydrocarbon, the process being carried out at an atomic ratio of nickel: chromium from 1:20 to 1: 1; Physico-mechanical characteristics of the polymer table 2 Tables 3.