SU1659424A1 - Method for obtaining polyisobutylene - Google Patents

Abstract

The invention relates to methods for producing polyisobutylene and can be used in the petrochemical industry, and polyisobutylene as a multifunctional lubricant additive. Improving the resistance to mechanical and thermal degradation and improving lubricating properties is achieved by a new method of polymerizing isobutylen at -10 ° C in alkyl chloride in the presence of aluminum trichloride; 2-mercaptobenzthiazole of the formula CeH-iNSCSH or Ti - licolic acid of the formula HSCH2COOH, or di- (n-butyl) -dithiophosphoric acid HSPSJpGjHg) 2. The number of stoppers 1.50 - 6.5 May. % of isobutylene. 5 tab.

Description

The invention relates to a method for producing polyisobutylene and can be used in the petrochemical industry, and polyisobutylene as a multifunctional additive to lubricating oils.

The aim of the invention is to improve the performance of additives based on polyisobutylene.

An example (according to the invention). The polymerization is carried out at a temperature of -10 ° C in a jacketed steel reactor (to cool the reaction mixture) and a stirrer. Before starting the reaction, the reactor is thoroughly dried with nitrogen. 200 ml of liquefied isobutylene and 400 ml of ethyl chloride and 0.31 g (0.25% by weight of isobutylene) of aluminum trichloride are introduced into the reactor. Polymerization time is 15 min with constant stirring. Then 2.10 gtiglycolic acid (2.50 wt.% To the monomer) is added to the mixture. The resulting polyisobutylene is re-precipitated from solution with ethyl alcohol and subjected to vacuum drying at 60 ° C. Molecular weight is determined on a 150C A C / CPC Water Associated liquid gel permeation chromatography unit.

Data on molecular weight characteristics of polyisobutylene are given in table 1.

Examples 2-4. The method is carried out analogously to example 1, however, a certain amount of captax (2-mercaptobenzthiazole) is used as a stopper.

EXAMPLE 5 The method is carried out analogously to example 1, but 6.65 g (3 wt.% Of isobutylene) di- (n-butyl) -dithiophosphoric acid are used as a stopper.

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PRI me R 6 (known method). The polymerization is carried out at a temperature of -10 ° C in a jacketed steel reactor (to cool the reaction mixture) and a stirrer. Before starting the reaction, the reactor is thoroughly dried with nitrogen. 200 ml of liquefied isobutylene, 400 ml of ethyl chloride and 0.31 g (0.25 wt.% Of isobutylene) of aluminum trichloride are introduced into the reactor. Polymerization of isobutylene comes with a lot of heat. The reaction mixture is cooled through the jacket of the reactor with liquid nitrogen. The termination of the reaction is judged by the cessation of heat release. In this example, the polymerization time is 15 minutes. Polymerization is carried out under constant stirring. Then, 1.33 g (2% by weight of the monomer) of isobutyl alcohol is added to the mixture. The resulting polyisobutylene is reprecipitated from the solution with ethyl alcohol and vacuum dried at 60 ° C.

Example. The method is carried out analogously to example 1, but 1.97 g (1.5 wt.% Of the monomer) captax is used as a stopper.

As can be seen from Table 1, using stoppers of various chemical natures, one can obtain a whole spectrum of polyisobutylene with various molecular characteristics. The use of captax (example 3) and thioglycolic acid (example 1) as stoppers according to the invention makes it possible to reduce the polydispersity coefficient by more than two times, thereby improving the molecular characteristic of the polyisobutylene obtained.

Example The method is carried out analogously to example 1, however, the resulting polyisobutylene is precipitated from a solution with warm water (distilled) at a temperature of 35-45 ° C.

The use of water instead of ethyl alcohol to wash the polymerizate does not affect the molecular characteristics of polyisobutylene.

PRI me R 9 (control). The polymerization of isobutylene is carried out analogously to example 1, but a stopper — 2.10 g of thioglycolic acid is introduced into a solution of isobutylene in ethyl chloride prior to the introduction of the catalyst. The polymerization process after the introduction of the catalyst in these conditions is not,

Table 2 shows the results of tests of lubricating oils thickened with the additive P-20 obtained by the prototype and polyisobutylene obtained according to the invention. Investigate 10% solutions of polyisobutylene and P-20 in isoparaffin

oil brand IPMA. Stability to mechanical degradation is determined by the drop in viscosity of the oils thickened with the polyisobutylene obtained according to the invention and the prototype (P-20) after exposure to ultrasound oil 22 kHz for 20 minutes. Stability to thermal degradation is determined according to TU-38.101209-72.

As can be seen from table 2, the polyisobutylene obtained according to the invention is 4 to 21 times more stable than the additive P-20, to mechanical and thermal degradation.

The lubricating properties of polyisobutylene obtained according to the invention are evaluated on a four-ball machine of the ChSM brand No. ITS-MT-4 according to GOST 9490-75. The generalized wear rate and the scuffing index are dimensionless values calculated from the results of measuring the wear of balls from the initial load to the welding load. Using the polyisobutylene obtained according to the invention, the generalized wear rate of thickened oils increased by 8 to 16%, and the scuff index increased by 5-21.

Data on the thickening ability of polyisobutylene obtained according to the invention and the prototype are given in table 3. The disadvantage of P-20 grade polyisobutylene is a noticeable increase in the viscosity of oils at low temperatures VAQ / VW 4.52, where V40 is the kinematic viscosity of thickened oil at 40 ° C (vr kinematic viscosity at 100 ° C). With the thickening of the polyisobutylene amine oils obtained according to the invention, the V40 / Vioo ratio can be reduced to 3.51 - 3.91.

The viscosity index of thickened oils is calculated according to GOST 25371-82, which characterizes the change in viscosity of lubricating oils as a function of temperature. The higher the viscosity index, the more effective the thickening properties of the additive. When the oils are thickened by polyisobutylene obtained by the proposed method, the viscosity index rises from 153.36 (at thickening P-20) to 249.80 - 301.12.

The stability to thermal decomposition of oil solutions prepared by mechanical mixing (not by polymerization) of polyisobutylene with the substances used according to the invention as stoppers was tested.

The test results are shown in table 4.

As can be seen in table 4, the oil solutions obtained by simply mixing polyisobutylene with the substances used

in the proposed method, they do not have the properties of thermal degradation stability characteristic for solutions with polyisobutylene obtained according to the invention.

Table 5 shows the data on conversion, which characterize the stopping effect of the additives used according to the invention in comparison with the stopper by a known method.

As can be seen from Table 5, the substances used in the method have a stopping effect approximately the same as isobutanol.

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Claims (1)

The invention The method of producing polyisobutylene by polymerization of isobutylene at -10 ° C in alkyl chloride in the presence of three-chloride aluminum, followed by stopping, is used in order to improve the performance of additives based on polyisobutylene, 1.50 - 6.50% by weight of isobutylene of a compound selected from the group comprising 2-mercaptobenzthiazole of the formula CeH4NSCSH, thioglycolic acid, of the formula H5CH2COOHEDI- (n-butyl-dithiophosphoric acid of the formula HSPSCODiHgfe. Table f Stability to mechanical destruction,% Stability to thermal destruction,% Lubricity: load welding, kg load critical, kg generalized wear rate scuff index 5.39 4.88 4.96 6.57 7.14 30.82 6.11 5.40 6.00 2.00 1.70 4.99 3.45 35.56 5.80 6.00 158 71 158 .79 158 71 200 71 158 71 126 71 158 71 158 71 22.40 14.84 14.84 22.94 14.84 6.12 1 / .20 33.62 22.05 27.51 24.48 12.73 13.67 22.4 21.06 17.2 table 2 00 71 158 71 126 71 158 71 158 71 13.67 22.40 21.06 17.22 IndicatorsExample p.1 12345b7 ; | 1 (prototype) , 513,813,913,883,77 4,523,85 Index z zkosti282,66 301,12 292.80 249.13 270,10 153,36 280,1 chp- Table 4 Experience Substance with Stop-Stabilraminos. thermal destruction,% 1No matter35,56 22-Mercaptobenzthiazole35,04 3 Thioglycolic acid 35,72 4D- (n-butyl) -dithiophosphoric acid35,64 For example, e. 1. IPMA isoparaffin oil, polyisobutene concentration 10% (prototype). 2.6.5% 2-mercaptobenzthiazole by weight of polyisobutylene. 3.6.5% thioglycolic acid by weight of polyisobutylene. 4,6.5% di- (n butyl) -dithiophosphoric acid by weight of polyisobutylene. Table 5 Stopper 2-Mercaptobenztiazole51,6 Thioglycolic acid51, 4 Di- (n-butyl) -dithiophosphoric to-that 51,7 Isobutanol (prototype) 51,5 Table 3 Polymer yield, g | Conversion, / 92.3 91.9 91, .7 91.3