RU2599986C1 - Agent for reducing hydrodynamic resistance and method for production thereof - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to chemistry of polymers in additives used in transportation of oil and oil products. Described is a method of producing an agent for reducing hydrodynamic resistance of a hydrocarbon stream, which is a stabilised powdered high-molecular poly-alpha-olefin. Method involves polymerisation of higher alpha-olefins in medium of fluorinated organic compounds using a titanium-magnesium catalyst, modified with an electron-donor compound, followed by extraction of powdered poly-alpha-olefin and stabilisation of latter by adding an adhesion reducing powder. Electron-donor compound is glycol ethers, phthalic acid esters. Synthesis is carried out at a given ratio of components of system. Agent for reducing hydrodynamic resistance is characterised by component weight ratio, %: poly-alpha-olefin 80-90 %, adhesion reducing powder 10-20 %.

EFFECT: obtaining an agent for reducing hydrodynamic resistance in form of a stable powder composition, and which does not require additional conditions for storage and transportation of product.

3 cl, 1 tbl, 22 ex

Description

The invention relates to the field of transport of liquid hydrocarbons, products of the chemical and petrochemical industries, and in particular to methods for producing agents for reducing hydrodynamic resistance based on high molecular weight polymers. When introducing into the flow of transported hydrocarbons, agents to reduce the hydrodynamic resistance can increase the hydraulic efficiency of oil and oil pipelines.

The turbulent flow of liquid hydrocarbons is characterized by pulsations of temperature, pressure, density and flow rate. The flow rate, as one of the most important parameters, varies depending on the distance from the walls of the pipeline. The gradient of the flow velocity reaches a significant value in the wall region and grows more slowly at points of the cross section that are more remote from the walls. Thus, the turbulent flow regime is characterized by high energy consumption to ensure a given flow rate. The hydrodynamic drag reducing agent (hereinafter referred to as GDS), introduced into the transported fluid stream, damps the turbulent vortex structures due to the thickening of the laminar sublayer in the wall zone of the pipeline, providing an increase in the flow velocity, as well as a significant increase in the size of the transition zone. The combination of these factors allows to increase the efficiency of pumping oil and oil products by increasing the throughput of the conductive channel.

When moving in a pumped medium, polymer macromolecules undergo gradual conformation and ultimately partially collapse when local resistance is overcome and completely collapse when passing pumping stations.

The effectiveness of the agent to reduce GDS (anti-turbulent additives) the higher, the greater the molecular weight of the polymer and is preferably not less than 5 · 10 ⁶ .

The range of mass concentrations of the anti-turbulent additive is from 0.00000025 to 0.0001 and is limited, on the one hand, by the so-called “saturation effect”, in which introducing the additive in an amount exceeding the maximum value leads to an excessive thickening of the wall layer, an increase in its viscosity and as a consequence, a decrease in the flow rate of the pumped product, and on the other hand, the minimum value at which the anti-turbulent activity of the additive is not expressed.

Along with the requirements for the polymer component of the GDS reduction agent, there are a number of requirements for the commodity form, namely the kinetic stability of the commodity form, providing long-term storage and transportation over long distances, the absence of a tendency to agglomerate polymer particles in the commodity form, good solubility in hydrocarbon liquids, and the consistency of commodity forms that ensure the entry of PTP into the pipeline mainly without additional equipment and pre-training.

GDS reduction agents based on high molecular weight polyalpha-olefins meet the stated requirements and have become widespread, providing increased pipeline throughput and reduced energy consumption for pumping oil and oil products.

Active polymers as a part of GDS reduction agents are obtained by coordinating the polymerization of C ₄ -C ₁₄ higher alpha olefins using traditional first-generation Zingler-Natta catalysts, which are a series of systems including transition metal complexes (TiCl ₄ TiCl ₃ , VOCl ₃ and etc.) with alkyl derivatives of metals of groups I-III. However, a new generation of alpha-olefin polymerization catalyst systems including a titanium magnesium catalyst, an organoaluminum cocatalyst, and a stereo-regulating electron-donor compound are also widely used for the synthesis of polyalpha-olefins. The activity and isospecificity of the catalytic system, as well as the molecular mass distribution of the polymer, its isotactic index are due to the ratios of the internal and external electron-donor compounds, their molecular structure and other factors.

The anti-turbulent additives used today can be classified into two groups: gel (solution) additives and suspension type additives. Gel additives (for example, RU 2075485) are homogeneous solutions of polyalpha-olefins proper with the content of the latter not exceeding 10-12% in aliphatic hydrocarbons and are practically not used in practice due to their high viscosity and poor dissolution kinetics in oil products. In addition, the preparation of solution-type additives involves interrupting the polymerization process at the 20% stage due to the further formation of a low molecular weight ballast polymer and is therefore characterized by a high consumption of monomer. Another disadvantage of solution PTP is the need to pre-dissolve the highly viscous concentrate before entering the oil pipeline, as well as the use of high-pressure units and nozzles of a special form. Patents US 4756326, US 4771800 are devoted to solving this problem.

Suspension PTPs are finely dispersed suspensions containing up to 35% by weight of polymer particles in an aqueous or non-aqueous medium, the density of which is close to the density of the polymer, and have several advantages over gel ones, namely a lower viscosity that facilitates the introduction of additives into the pipeline without additional equipment, reduction of transport costs to the place of introduction of anti-TB drugs due to the higher concentration of active polymer in commodity form.

One of the possible options for the synthesis of suspension PTP (US patent 6399676) is to obtain a suspension based on polyalpha-olefin, subjected to cryo-grinding. The technology described in the patent offers the grinding of non-crystalline ultra-high molecular weight polyalpha-olefins (M> 1 · 10 ⁶ predominantly M equal to about 5 · 10 ⁶ ) at a temperature below the glass transition temperature, from -10 ° C to -100 ° C, followed by separation of the obtained polymer into fractions with a particle size of ≤400 μm and with a particle size of more than 400 μm to be recycled cryogrinding. Traditionally, the product of coordination (co) polymerization of higher alpha-olefins on Zingler-Natta catalysts is subjected to grinding at cryogenic temperatures and then suspended in a non-solvent medium with the addition of a separating agent (anti-agglomerator) (linear alcohol ethoxylates, anionic surfactants are used as anti-agglomerator, such as alkyl benzene sulfonates and alcohol ethoxylate sulfates, for example sodium lauryl sulfate). However, a significant difference between a specific technological scheme is the addition of a dispersant before cryogenic grinding. The main disadvantages of cryo-grinding should include the mechanical destruction of polymer macromolecules and, as a consequence, the deterioration of its effectiveness in reducing hydrodynamic resistance, as well as the high consumption of cooling agents and equipment for the implementation of the industrial process.

The microencapsulation method also allows to obtain a suspension form of PTP. A known method of producing a hydrodynamic drag reducing agent according to patent US 6160036 by (co) polymerization of higher alpha-olefins on Zingler-Natta catalytic systems, such as titanium trichloride with diethylaluminium chloride, inside microcapsules enclosed in an inert to the core components shell, which is waxes, polymethacrylates, polyethylene glycol and its esters, polyethylene waxes, stearic acid. Technically, the process is ensured by passing a catalytic mixture of titanium trichloride and diethylaluminium chloride pretreated with kerasin and liquid alpha olefin through a small-diameter channel of the nozzle simultaneously with the shell component through the annulus of the nozzle. Despite the fact that the microencapsulation method avoids particle adhesion, a number of its disadvantages can be distinguished: a long polymerization time of up to 72 hours, pre-preparation of an agent for reducing the GDS in order to activate it by destroying the capsule shell by dissolution, mechanical destruction by ultrasound, and melting (in synthetic waxes), as well as low microencapsulation process performance.

A known method for producing a suspension-type antiturbulent additive is described in RU 2443720. According to this method, the polymerization of higher alpha-olefins is carried out on Ziegler-Natta catalysts (a mixture of TiCl ₃ with diethylaluminium chloride) in perfluorinated alkanes. The suspension form of the anti-turbulent additive is obtained by decanting the organofluorine solvent and dispersing the product in an anti-agglomerator containing medium. As the dispersion medium, higher aliphatic alcohols, glycols and their mono- and disubstituted ethers, as well as mixtures thereof, are used. This technical solution is the closest in technical essence and is selected as the closest analogue.

The disadvantage of this method is the fact that the used catalytic system, namely a mixture of titanium trichloride with organoaluminum with the catalysts, does not allow to obtain ultrahigh molecular weight polymer (average value according to the source Mr 6.85 · 10 ⁶ ). In addition, a mixture of titanium trichloride with diethylaluminium chloride in the presence of hexene-1 is a jelly-like mass and is not an optimal phase for suspension polymerization in perfluoroalkane. Also, the first generation Zingler-Natta catalysts used in this method are characterized by relatively low productivity and stereospecificity. Finally, the suspension of the commodity form requires the observance of additional conditions during transportation and storage of anti-turbulent additives.

The objective of the claimed technical solution is to develop such a method for producing a GDS reduction agent, the implementation of which allows one to obtain an ultrahigh molecular weight isotactic polymer in the form of a stable powder composition by (co) polymerization of alpha-olefins using a finely dispersed catalyst suspension, which ensures the optimal flow of the process. The objective of the proposed technical solution is also to obtain the commodity form of an agent for reducing GDS, which does not require additional storage and transportation of the product.

The problem is achieved in that the method for producing a GDS reduction agent consists in the polymerization of higher alpha olefins in the medium of at least one fluorinated organic compound using a titanium-magnesium catalyst modified with an electron-donor compound and its subsequent isolation in stable powder form. The synthesis is carried out in the following ratio of system components: fluorinated organic compound (s): alpha-olefin (mixture of alpha-olefins) is selected from the range from 1: 5 to 5: 1; alpha olefin (mixture of alpha olefins): titanium magnesium catalyst (calculated on Ti) from 10,000: 1 to 2,500,000: 1; titanium magnesium catalyst: cocatalyst from 1:10 to 1: 1000.

The problem is also solved by the fact that the composition of the claimed agent to reduce the hydrodynamic resistance has a ratio of components by mass,%:

polyalpha olefin 80-90 antiagglomerator 10-20

The specified method allows to obtain ultra-high molecular weight isotactic polymer in powder form with a particle size of up to 500 microns in the presence of additives that prevent them from re-sticking. The synthesis of the polymer takes place in one stage without the use of mechanical grinding, with effective heat removal (in contrast to the difficult heat removal during block polymerization).

The synthesis temperature was chosen taking into account the following factors: firstly, the temperature is set higher than the coalescence point of the system, preventing the release of higher alpha-olefin, which is a solvent for polyalpha-olefin, in the form of a liquid phase; secondly, it is empirically selected based on the ratio of the reaction rate and the molecular weight of the polymer: with increasing temperature, the productivity of the process increases, but the quality of the resulting polymer deteriorates (the molecular weight of the polymer naturally decreases).

The range of ratios of fluorinated organic compound (s): alpha-olefin (a mixture of alpha-olefins) is chosen due to the following factors: with insufficient amounts of alpha-olefin, the reaction rate and polymer yield are significantly reduced, on the contrary, with an excess of it, the polymerization process proceeds uncontrollably, characterized by the inevitable agglomeration of clumps of polyalpha-olefin, as well as the low molecular weight of the resulting polymer.

On the one hand, fluorinated organic compounds used as a polymerization medium for alpha-olefins do not affect the activity of the catalytic system, and on the other hand, they allow suspension polymerization without dissolving the polyalpha-olefin obtained during the process. Also, the fluorinated organic compounds used are not difficult to separate from the polyalpha-olefin due to the difference in density and can be recycled.

Organofluorine compounds are selected from the series: aliphatic perfluoroalkanes (for example, 1H, 8H-perfluorooctane, 1H, 6H-perfluorohexane, perfluoroheptane), cyclic (for example, perfluoro-1,3-diethylcyclohexane, perfluorodimethylcyclohexane, perfluoromethylfluorohexane or as well as polyhalogenated alkanes and cycloalkanes (e.g. 1-chloro-nonafluorobutane, chloroperfluorocyclohexane), but are not limited to them.

Alpha olefins, such as butene-1, hexene-1, octene-1, less often penten-1, hepten-1, nonen-1, decen-1 of a linear and even less often branched structure, are used as a monomer. The choice of specific alpha-olefin (s) for (co) polymerization is determined by the optimal chain length of the final polymer, which provides the best anti-turbulent activity of the GDS reduction agent.

As mentioned above, the use of titanium-magnesium catalysts provides increased productivity (compared with titanium trichloride) of the polymerization process, and in combination with an electron-donor modifier allows you to change the catalytic centers and to obtain ultrahigh molecular weight isotactic polymer.

The electron-supporting modifier included in the titanium-magnesium catalyst is selected from a number of ethers (glycol ethers, for example, 2,2-diisobutylpropanediol-1,3 dimethyl ether, 2,2-dimethylpropanediol-1,3, 1,2- dimethyl ether dimethoxyethane, 2,2,4-trimethylpentaidiol-1,3 dimethyl ether, etc.), phthalic acid esters - dialkyl phthalates, for example: dibutyl phthalate, organic phosphines of the general formula R ₃ P (where R is aryl, alkyl, for example, tributylphosphine, triphenylphosphine, tritolylphosphine, etc.).

The dispersion medium is higher alcohols and glycols, their mono and disubstituted ethers and mixtures (for example: 2-methylbutanol-1, 2,2-dimethylpropanol, hexanol-1, 2-ethylhexanol-1, butanol-1, 3-methyl- butan-1-ol, 1,2-ethanediol, 1,3-propanediol, 1,4-butylene glycol, ethyl cellosolve, butyl cellosolve, methylcarbitol, 1,2-dimethoxyethane, methyl cellosolve, etc.).

Amides of saturated and unsaturated fatty acids (N, N′-ethylene bis (stearamide), calcium, magnesium, aluminum salts of saturated and unsaturated fatty acids (calcium stearate, magnesium oleate, aluminum myristate), ethoxylated, hydroxypropylated fatty alcohols are used as an anti-agglomerator mono-, di- and triglycerides of fatty acids and their alcohols (oleic acid monoglyceride, stearic acid diglyceride), imidozolines of fatty acids.

Magnesium titanium catalysts can be synthesized in one of the following ways:

- Interaction of finely divided magnesium chloride with titanium tetrachloride. Such systems are characterized by an irregular structure, low productivity and are currently practically not used;

- Interaction of solvates formed by magnesium chloride and aliphatic alcohols with titanium tetrachloride (the so-called "crystallization" scheme). In this case, crystalline phases of magnesium chloride with a relatively regular structure are formed, on the surface of which titanium chloride is adsorbed. The restoration of the latter into a catalytically active form occurs when organoaluminum activator is added;

- Interaction of magnesium alcoholates (ethylate, ethylhexylate) with titanium tetrachloride. Magnesium alcoholate is prepared either by the interaction of magnesium with alcohol (in this case, it contains a noticeable amount of solvate ROH), or by alcoholysis of the Grignard reagent. Modification of the method - the use in the reaction with RMgX-orthosilicates instead of alcohols.

- Interaction of Grignard reagents with titanium tetrachloride. The catalyst obtained by this method is characterized by moderate activity and high polydispersity of particles. A modification of the method is the interaction of magnesium without solvent or in an aliphatic solvent with an alkyl halide containing titanium tetrachloride. The catalyst obtained by reacting butyl chloride with magnesium in the presence of titanium tetrachloride shows a rather high activity in the polymerization of hexene-1.

It has been experimentally established that, in a series of alkylaluminum organic cocatalysts, the use of triisobutylaluminum (TIBA) is optimal.

In the claimed technical solution, the following stages can be distinguished:

- catalytic (co) polymerization of higher alpha olefins in an environment of fluorinated organic compounds in an inert atmosphere;

- interruption of the polymerization process upon reaching a conversion of an average of 40-95%;

- adding a dispersion medium, including anti-agglomerator, decantation of a suspension of polyalpha-olefin;

- washing the suspension of (co) polymer using filter materials;

- vacuum drying at a temperature of 40-60 ° C to remove unreacted monomer and residual solvents.

The suspension of the (co) polymer suspension is washed with alcohols (e.g. methyl, ethyl, propyl, isopropyl), ketones (e.g. acetone, methyl ethyl ketone), esters (methyl formate, ethyl formate, methyl acetate, ethyl acetate, dimethyl carbonate, dimethyl malonate).

In examples 1-4, the above methods for producing various types of gytans magnesium catalysts for the polymerization of alpha-olefins are presented.

Examples 5-20 confirm, but do not limit, the preparation of a GDS reduction agent.

Example 1

In a 100 ml flask with a magnetic stirrer in a stream of argon, 5 g (44 mmol) of magnesium ethylate, 40 ml of absolute toluene, 10 ml of titanium tetrachloride and 0.95 ml (0.80 g, 5 mmol) of dimethyl ether 2.2- were placed diethylpropanediol-1,3. The mixture was heated to 115 ° C (external temperature in the bath) for 2 hours with stirring. Then the liquid layer was decanted, the precipitate was washed with 2 × 40 ml of toluene at 40 ° C. After washing, 40 ml of absolute toluene, 8 ml of titanium tetrachloride were placed in the flask and the mixture was heated to 115 ° C for 1.5 hours with stirring. Next, the precipitate was washed with 10 × 40 ml of 70/100 petroleum ether at 55 ° C, and the precipitate was suspended in 40 ml of 70/100 petroleum ether. Received 50 ml of a suspension of catalyst with a titanium concentration of 0.06 mol / L.

Example 2

5 g (44 mmol) of magnesium ethylate, 40 ml of absolute toluene, 10 ml of titanium tetrachloride and 14 ml of dibutyl phthalate were placed in a 100 ml flask with a magnetic stirrer in a stream of argon. The mixture was heated to 115 ° C for 2 hours with stirring. Then the liquid layer was decanted, the precipitate was washed with 2 × 40 ml of toluene at 40 ° C. After washing, 40 ml of absolute toluene, 8 ml of titanium tetrachloride were placed in the flask and the mixture was heated to 115 ° C for 1.5 hours with stirring. Next, the precipitate was washed with 10 × 40 ml of 70/100 petroleum ether at 55 ° C, and the precipitate was suspended in 40 ml of 70/100 petroleum ether. Received 50 ml of a suspension of catalyst with a titanium concentration of 0.06 mol / L.

Example 3

Stage (a). 2.6 g (107 mmol) of magnesium metal were charged into a three-necked flask equipped with a reflux condenser and a dropping funnel. The flask was purged with argon. The magnesium was heated for 30 min at 80 ° C in vacuo and then a mixture of 17.3 ml of dibutyl ether and 8 ml of chlorobenzene was added. Then, 3 mg of iodine and 0.3 ml of n-butyl chloride were successively added to the reaction mixture. After the disappearance of iodine staining, the temperature of the mixture was increased to 97 ° C and 25 ml of chlorobenzene was slowly added over 2.5 hours. The resulting reaction mixture was stirred vigorously for 40 hours at 97 ° C.

Stage (b). The suspension obtained in step (a) (10 ml, 25 mmol Mg) was charged into a two-necked flask. The flask was cooled to 0 ° C and a mixture of 2.2 ml of tetraethoxysilane and 3.8 ml of heptane was added over 2 hours with stirring. After that, the reaction mixture was kept at 0 ° C for another 30 min and, with vigorous stirring, a mixture of 1.46 ml of ethanol (25 mmol) and 4.54 ml of heptane was dosed for 1 h. Then the temperature of the reaction mixture was increased to 70 ° C and kept at this temperature for 2 hours. After that, the mixture was cooled to room temperature and the next day the liquid over the precipitate was decanted. The precipitate was washed with 4 × 25 ml of heptane and suspended in 10 ml of heptane.

Stage (c). A mixture of 15 ml of titanium tetrachloride, 15 ml of toluene and 4.8 ml of the suspension obtained in the previous step was sequentially charged into a two-necked flask in an argon stream. The reaction mixture was heated to 90 ° C, 0.52 ml (0.436 g) of 2,2-diethylpropanediol-1.3 dimethyl ether was added and the mixture was kept at 115 ° C for 1 h. After this, stirring was stopped and the solid product was allowed to settle. The supernatant was removed by decantation, after which a mixture of 15 ml of titanium tetrachloride and 15 ml of toluene was added. The reaction mixture was again heated to 115 ° C for 30 minutes with stirring, after which the solid was allowed to settle. This last cycle was repeated again. The resulting solid was washed with 5 × 30 ml of heptane at 60 ° C. The precipitate was suspended in 10 ml of heptane. Received 12 ml of a suspension of catalyst.

Example 4

In a 250 ml three-necked flask equipped with a reflux condenser, a magnetic stirrer and a thermostatically controlled bath, 5 g (206 mmol) of magnesium shavings were placed and heated in vacuo. In a stream of argon, 55 ml of butyl chloride, 1.31 ml (11.83 mmol) of titanium tetrachloride were introduced and stirring and a bath thermostat at 80 ° C were turned on. Four hours after the onset of the turbulent stage, 35 ml of petroleum ether and 1.52 g (9.464 mmol) of 2,2-diethylpropanediol-1,3 dimethyl ether were added to the reaction mixture and stirred for 30 minutes at 65 ° C. The mixture was then filtered under argon and washed with 2 × 35 ml of petroleum ether. The precipitate was dried in vacuo. Yield 18.7 g. [Ti] = 2.7% of the mass.

Examples of the method of obtaining the claimed agent to reduce GDS.

Example 5

A three-necked 250-ml flask equipped with an argon-vacuum line and a mechanical stirrer was heated in vacuum for 5-10 minutes. 40 ml (71.37 g) of perfluoromethylcyclohexane, 80 ml (54.24 g) of hexene-1, 0.5 ml of TIBA (4M) and 0.2 ml were placed in a flask cooled with ice-water to 12-14 ° C. the catalyst prepared in Example 1. The mixture was stirred for 4 hours and then warmed to room temperature (~ 5 min) and a suspension of 4.5 g of calcium stearate in 41 g of butyl cellosolve was added. The mixture was vigorously stirred for 20 minutes, stirring was stopped, and after 10 minutes the perfluoromethylcyclohexane precipitate was decanted. The residues of perfluoromethylcyclohexane and monomer were distilled off in vacuo. Then the product was washed twice with 20 ml of acetone, filtered and dried. The mass of the obtained polymer powder was 41.68 g (69% conversion). Mass fraction of polymer 89.2%.

Example 6

A three-necked 250-ml flask equipped with an argon-vacuum line and a mechanical stirrer was heated in vacuum for 5-10 minutes. 40 ml (71.37 g) of perfluoromethylcyclohexane, 64 ml (43.40 g) of hexene-1, 16 ml (11.44 g) of octene-1, 0 were placed in a flask cooled with ice water to 13-15 ° C. , 5 ml of TIBA (4M) and 0.2 ml of the catalyst prepared in Example 1. The mixture was stirred for 4 hours and then warmed to room temperature (~ 5 min) and a suspension of 4.4 g of calcium stearate in 42 g of butanol was added. The mixture was vigorously stirred for 20 minutes, stirring was stopped, and after 10 minutes the perfluoromethylcyclohexane precipitate was decanted. The product was filtered and washed with 40 ml of ethyl alcohol. Then, the residual alcohols, perfluoromethylcyclohexane and monomer were distilled off in vacuo. The yield of polymer powder is 44.42 g (81% conversion), the mass fraction of polyalpha-olefin is 90.0%.

Example 7

A three-necked 250-ml flask equipped with an argon-vacuum line and a mechanical stirrer was heated in vacuum for 5-10 minutes. 40 ml (71.37 g) of perfluoromethylcyclohexane, 72 ml (48.82 g) of hexene-1 in a solution of isopentane in the ratio of isopentane: hexene-1 equal to 1 were placed in a flask cooled with ice water to 4-6 ° C: 3, 12 ml (8.89 g) of decene-1, 0.5 ml of TIBA (4M) and 0.2 ml of the catalyst prepared in Example 1. The mixture was stirred for 4 hours, then warmed to room temperature (~ 5 min ) and a suspension of 6 g of calcium stearate in 45 g of butyl cellosolve was added. The mixture was vigorously stirred for 20 minutes, stirring was stopped, and after 10 minutes the perfluoromethylcyclohexane precipitate was decanted. Then, the residues of perfluoromethylcyclohexane and monomer were distilled off in vacuo. The product was washed twice with 20 ml of methanol and filtered. The yield of polymer powder is 46.17 g (conversion 71%), the mass fraction of polyalpha-olefin is 87.0%.

Example 8

A three-necked 250-ml flask equipped with an argon-vacuum line and a mechanical stirrer was heated in vacuum for 5-10 minutes. 40 ml (71.07 g) of perfluoromethylcyclohexane, 40 ml (27.12 g) of hexene-1, 40 ml of butene-1 (cooled to -50 ° C) were placed in a flask cooled with ice water to 4-7 ° C. , 0.5 ml of TIBA (4M) and 0.2 ml of the catalyst prepared in Example 1. The mixture was stirred for 4 hours, then warmed to room temperature (~ 5 min) and a suspension of 8.4 g of calcium stearate in 44 g was added. butyl cellosolve. The mixture was vigorously stirred for 20 minutes, stirring was stopped, and after 10 minutes the perfluoromethylcyclohexane precipitate was decanted. Then, the residues of perfluoromethylcyclohexane and monomer were distilled off in vacuo. The product was washed three times with 15 ml of methanol, filtered. Yield 48.70 g (conversion 87%), mass fraction of polyalpha-olefin 83.7%.

Example 9

It differs from Example 5 by the use of the catalyst prepared in Example 2 (without using an external donor) and a calcium stearate mass of 6.4 g. Washing was carried out three times: 25, 15 and 10 ml of acetone, respectively. The yield of polymer powder is 51.5 g (conversion 84%), the mass fraction of polyalpha-olefin is 87.6%.

Example 10

It differs from Example 5 using the catalyst prepared in Example 2, 0.48 ml of phenyltriethoxysilane was used as an external donor, the polymerization duration was 5 hours. Calcium stearate was 5 g. The washing was carried out 3 times with 15 ml of isopropanol. The yield of polymer powder is 53.46 g (80% conversion), the mass fraction of polyalpha-olefin is 89.7%.

Example 11

Differs from example 5 using the catalyst prepared in Example 3, and the ratio of alpha-olefin: titanium-magnesium catalyst (in terms of titanium) 2500000: 1. Washing was carried out three times with 10, 15 and 15 ml of dimethyl malonate, respectively. The yield of polymer powder is 47.94 g (80% conversion), the mass fraction of polyalpha-olefin is 89.3%.

Example 12

It differs from Example 5 by the use of the catalyst prepared in Example 4, 40 mg, the weight of hexene-1 used is 10.96 g, and the weight of calcium stearate is 0.9 g. Three basins of 5 ml of methyl formate were washed. The yield of polymer powder is 7.7 g (conversion 58%), the mass fraction of polyalpha-olefin is 84.3%.

Example 13

Differs from example 5 using 17.3 ml of perfluoromethylcyclohexane (volume ratio of hexene-1: perfluoromethylcyclohexane 5: 1) and using 85 g of butanol-1 in the preparation of the suspension. Washing was carried out with ethyl formate three times in 30 ml each. The yield of polymer powder 45.5 g (conversion 70%), the mass fraction of polyalpha-olefin 89.9%.

Example 14

A three-necked 250-ml flask equipped with an argon-vacuum line and a mechanical stirrer was heated in vacuum for 5-10 minutes. In a flask cooled with ice-water to 12-14 ° C, 100 ml (180 g) of perfluoromethylcyclohexane, 20 ml (13.56 g) of hexene-1 (volume ratio of hexene-1: perfluoromethylcyclohexane 1: 5) were placed, 0.5 ml of TIBA (4M) and 0.2 ml of the catalyst prepared in Example 1. The mixture was stirred for 6 hours, then warmed to room temperature (~ 5 min) and a suspension of 0.7 g of calcium stearate in 7 g of tert-butyl alcohol was added. The mixture was vigorously stirred for 20 minutes, stirring was stopped, and after 10 minutes the perfluoromethylcyclohexane precipitate was decanted. The product was washed and filtered three times with 45, 25 and 20 ml of water, respectively. Then, the residues of perfluoromethylcyclohexane and monomer were distilled off in vacuo. The yield of polymer powder is 6.88 g (69%), the mass fraction of polyalpha-olefin is 84.3%.

Example 15

Differs from Example 5 using perfluorodimethylcyclohexane as an organofluorine solvent and carrying out the polymerization process at 20 ° C. Washing was carried out twice with 20 ml acetone. Yield 41.5 g (conversion 69%), mass fraction of polyalpha-olefin 89.1%.

Example 16

It differs from Example 5 by the use of perfluoroheptane as an organofluorine solvent and the polymerization process at 20 ° C. The washing was carried out with propanol-1 three times: two times 15 ml each and the last time 10 ml. Yield 43.5 g (conversion 73%), mass fraction of polyalpha-olefin 89.6%.

Example 17

Differs from Example 5 using perfluorohexane as an organofluorine solvent and a molar ratio of titanium-magnesium catalyst: cocatalyst equal to 1:10. Washing was carried out with methyl acetate three times in 10, 15 and 20 ml, respectively. Yield 41.2 g (conversion 67%), mass fraction of polyalpha-olefin 89.0%.

Example 18

It differs from Example 5 using chloroperfluorocyclohexane as an organofluorine solvent and a molar ratio of titanium-magnesium catalyst: cocatalyst equal to 1: 1000. The washing was carried out with ethyl acetate three times in 10, 15 and 20 ml, respectively. Yield 40.1 g (conversion 67%), mass fraction of polyalpha-olefin 88.8%.

Example 19

It differs from Example 5 using hexene-1 in a solution of perfluorocyclohexane in the ratio of perfluorocyclohexane: hexene-1, equal to 1: 3, and the temperature of the process 14-16 ° C. Washing was carried out three times with dimethyl carbonate, 10, 15 and 15 ml, respectively. Yield 39.1 g (conversion 63%); mass fraction of polyalpha-olefin 88.5%.

Example 20 (comparative, by the method described in the closest analogue - patent RU 2443720)

A three-necked 300-ml flask equipped with an argon-vacuum line and a mechanical stirrer was heated in vacuum for 5-10 minutes. 100 ml of perfluoromethylcyclohexane, 60 ml (40.7 g) of hexene-1, 0.2 g of diethylaluminium chloride and 2 mg of microspherical titanium trichloride (suspended in 18 μl of hexene-1) were placed in the flask. The mixture was stirred for 5 hours and a suspension of 3 g of calcium stearate in 25 g of butyl cellosolve was added. The mixture was vigorously stirred for 20 minutes, stirring was stopped, and after 10 minutes the perfluoromethylcyclohexane precipitate was decanted. Then, the residues of perfluoromethylcyclohexane and monomer were distilled off in vacuo. 47 g of butanol were added to the polymer flask. Yield 24.4 g (conversion 60%); polymer concentration in suspension 25% mass; suspension yield 97.80 g.

Example 21

Obtained by the recipe of Examples 5-20, the polymers were tested to determine their ability to reduce hydrodynamic resistance. The hydrodynamic resistance value was measured on a capillary-type turbulent rheometer. The decrease in the hydrodynamic resistance DR was calculated by the formula

where λ ₀ is the coefficient of hydrodynamic resistance for a pure solvent,

λ _p - hydrodynamic drag coefficient for the test solution,

t ₀ is the expiration time of a fixed volume of pure solvent through the capillary,

t _p is the expiration time of a fixed volume of the test solution through the capillary.

The studied solutions were prepared by dissolving the obtained (in Examples 5-20) powdery polymers in n-hexane. The test results are shown in Table 1.

The effectiveness of the hydrodynamic drag reducing agent is expressed by the concentration of the polymer at which a 30% decrease in hydrodynamic drag is observed.

Example 22 (comparative)

According to the method described in Example 21, Baker Hughes additives were tested. The results are shown in the table.

The above examples of experiments confirm the receipt of the agent reducing the GDS of the claimed method, and the data of the Table show the characteristics obtained in the specified method polyalpha-olefins in its composition.

As follows from the results of the experiments, as well as the data of the Table, the claimed method allows to obtain a GDS reduction agent with a concentration of ultrahigh molecular weight isotactic polyalpha-olefin of at least 80%, having a molecular weight of up to 11.5 · 10 ⁶ g / mol, in a stable powder form with a size particles up to 500 microns, simplifying the storage and transportation of the agent reducing the SDS. Obtained by this method, the polyalpha-olefin has an efficiency of reducing GDS by 30% at a polymer concentration of 0.25 ppm or more.

Claims (3)

1. A method of obtaining an agent for reducing hydrodynamic resistance, which consists in carrying out the polymerization of higher alpha-olefins in a medium of fluorinated organic compounds, characterized in that the titanium-magnesium catalyst modified with an electron-donor compound is used as a polymerization catalyst, the synthesis is carried out in the following ratios: fluorinated (s) organic compound (s) compound (s): alpha-olefin (mixture of alpha-olefins) is selected from the range from 1: 5 to 5: 1; alpha olefin (mixture of alpha olefins): titanium magnesium catalyst from 10,000: 1 to 2,500,000: 1; titanium magnesium catalyst: cocatalyst from 1:10 to 1: 1000, followed by its isolation in a stable powder form by adding an anti-agglomerator. 2. A method of producing an agent for reducing hydrodynamic resistance according to claim 1, characterized in that glycol ethers, phthalic acid esters are used as the electron-donor compound. 3. The composition of the agent to reduce the hydrodynamic resistance obtained by the method according to p. 1, characterized in that it has the following ratio of components, wt.%:
Polyalfa-olefin 80-90 Antiagglomerator 10-20