SU422192A1 - Method of preparing catalyst for polymerization of olefins - Google Patents

Description

The invention relates to a method for preparing a catalyst for the polymerization of olefins based on various transition metal compounds supported on solid oxide carriers. A known catalyst for the polymerization of olefips, comprising in its composition a transition metal compound deposited on an oxide carrier MxOy, containing on its surface the functional groups of the compound tava M-O-Me RaXb, where Me is a metal of the II-V groups of the Periodic System, R is an alkyl or aryl radical, X is halogen or hydrogen at, 0, a + B + -jl :: N, where N is the group number. A carrier for 15 of these catalysts containing the indicated functional groups is prepared by treating an oxide support containing hydroxyl groups with organoaluminum compounds of the general formula AlRxCly or BClc in 20 in accordance with the reactions: SJOHI-BClj - -; j: 0-bCl2 + HCl; -lO -Ai: When using carriers containing 5. 25 30 Si-O-A1R2 surface compounds with two alkyl groups, the catalyst is less active than support-based catalysts with SiOAlRCl and SiOBCb surface compounds containing chlorine. The most active catalyst is obtained by using a carrier with SiUeCi2 groups of chlorine containing only chlorine, without alkyl groups. However, BCIs are not easily accessible for industrial use. In order to increase the activity of the supported titanium catalyst and simplify the preparation of the oxide carrier, which consists in the formation of functional SiOAlCls groups that do not contain alkyl substituents, they propose a method of preparing supported titanium catalysts, which means that the preparation of the oxide carrier containing functional groups of SiOAlCla, are carried out by sequential treatment of the support with triethyl aluminum and gaseous chloride in portly at O-300 ° C. The procedure for preparing the supported titanium catalyst includes the following steps: I. Removal of water adsorbed on the surface of the support. This stage can be carried out by heating the carrier in a vacuum, in a stream of dry gas or air at a temperature of

less than 100 ° C, but not higher than the sintering temperature of the carrier (900 ° C).

II. Processing of the carrier in pairs or a solution of triethylaluminum in an organic solvent at a temperature of -20 to 200C.

III. Washing, if necessary, an excess of unreacted triethylaluminum with an organic solvent.

IV. Removal of the organic solvent by vacuuming at O-200 ° C or in a stream of inert gas at 100-200 ° C.

V. Treatment of the catalyst with gaseous hydrogen chloride at O-300 ° C.

VI. Removal of the reaction products by evacuating at 20–600 ° C or purging with an inert gas at 20–600 ° C.

VII. Application of the organo-aluminum compound in the form of liquids or swell in an amount necessary to reduce a certain amount of transition metal halide.

VIII. The application of a transition metal halide of irreplaceable valence in the highest degree of oxidation to a carrier in the form of a liquid or a vapor.

IX. Restoration of a deposited transition metal halide by a previously deposited organoaluminum compound at a temperature of from -30 to 50 ° C.

X. Vacuum obtained products at 20-300 ° C or purging with an inert gas at the same temperature.

All catalyst preparation operations are carried out in vacuum or in inert gas (nitrogen, argon), thoroughly cleaned from traces of moisture, oil, and oxygen.

It is advisable to carry out the polymerization at 30–120 ° C, a pressure of 1–40 atm in the presence of cocatalysts — free organometallic compounds (often organoaluminum compounds). It is recommended to use triethylaluminum or triisobutl aluminum as a cocatalyst. The polymerization can be carried out either in a hydrocarbon solution or without a solvent (gas phase complete polymerisation). Regulation of the molecular weight of the resulting nolmer can be carried out by introducing hydrogen in an amount of 5-90 mol. % relative to the monomer.

The polymerization is carried out at an ethylene pressure of 3.0-6.0 kg / cm, temperature 80 ° C in the environment of gasoline when moving. Triethyl aluminum is used as cocatalyst. The molar ratio of Al / Ti 25. The results of the tests of the catalysts are given in the table.

Note. In examples 1 and 3, the polymerization is carried out at a pressure of 6 kg / cm. In example 2, at a pressure of 3 kg / cm.

Example 1. 1g of silica gel with a surface of 500 is calcined at 300 ° C in vacuum (10-2 jyjjj р (,) After that, the silica gel is treated at 150 ° C with 0.5 ml of a 90% solution of triethylaluminum and then with gaseous hydrogen chloride for 1 h at 150 ° C. The reaction products are pumped out to a vacuum of 10-2 jyij p (and drP1 150 ° C. Then 4 ml of a 23% solution of monoethyl aluminum dichloride in gasoline and 0.08 g of TiCU are added. After 1 h, exposure to nrn at room temperature the catalyst is pumped out at 300 ° C.

Example 2. 2 g of silica gel with a surface of 300 calcined in vacuum (10 mm Hg. Art.) At 400 ° C, then treated with 0.3 ml of 94.2% aqueous solution of aluminum triethyl at 150 ° C, then with gaseous hydrogen chloride in for 1 h at 150 ° C. Excess hydrogen chloride and the reaction products are pumped out at 150 ° C to a vacuum of 10 mm Hg.

Art., then 0.13 ml of 100% aluminum monoethyl dichloride and 0.66 g of TiCU are added. After 1 hour at room temperature, the catalyst is pumped out at 300 ° C.

Example 3. The catalyst was prepared without treatment with hydrogen chloride and used for comparison with the catalysts prepared by the inventive method.

The results of testing catalysts shown in the table show that the catalysts prepared by the proposed method (examples 1 and 2) are more active than the catalysts prepared by a known method.

Claims (1)

Invention Formula The method of preparing a catalyst for the polymerization of olefins by applying a transition metal halide of groups IV-V of the Periodic System on a solid oxide carrier MxOv containing on its surface M-O-AlCb functional groups, where M is an element of the III-IV groups of the Periodic System,, that distinguishes-5 so that, in order to increase the catalyst activity and to simplify the method of its preparation, the oxide support is successively treated with triethylaluminium and then with hydrogen chloride at ~ 300 ° C.