RU2212936C2 - Catalytic system for oligomerization of olefins, method for its preparing and oligomerization method - Google Patents

Abstract

FIELD: organic chemistry, chemical technology. SUBSTANCE: invention relates to cationic catalytic systems for oligomerization of individual C₃-C₁₄- olefins or their mixtures in bases for synthetic poly-alpha-olefinic oils (PAOO). Invention describes catalytic system for cationic oligomerization of individual C₃-C₁₄-olefins or their mixtures in bases of synthetic PAOO. The system comprises active aluminum or its alloys, for example, with magnesium or titanium as materials (bodies) with developed surface, halide-organic compound RX as co-catalyst wherein R is primary, secondary or tertiary alkyl, allyl, acetyl or benzoyl; X is chlorine, bromine or iodine atom being the system comprises from 1 to 50 moles of halide-organic compound per each g-atom of aluminum. Invention describes method for preparing this composition and method for oligomerization of individual C₃-C₁₄-olefins or their mixtures in bases of synthetic PAOO. The proposed catalytic system shows enhanced activity, output and allows regulation of the oligomerization rate. EFFECT: improved properties, enhanced effectiveness of system. 10 cl, 7 tbl, 120 ex

Description

The invention relates to chemistry, specifically to cationic catalytic systems (catalysts) for oligomerization of individual or mixtures of C ₃ -C ₁₄ olefins into the bases of synthetic polyalphaolefin (more precisely, oligoolefin) oils (PAOM).

 The invention may find application in the chemical and petrochemical industries, in factories for the production of basic PAOM and other products using cationic catalysts.

The oligomerization products of C ₃ -C ₁₄ olefins are used as the basis for the preparation of low-curing all-weather motor (automotive, aviation, helicopter, tractor, tank, etc.), transmission, gear, vacuum, compressor, refrigeration, transformer, electrical insulating, spindle and other types of oils, as well as heat carriers; plasticizers for plastics, rubbers, solid rocket fuels; raw materials for additives, emulsifiers, flotation agents, foaming agents, components of cutting fluids and hydraulic fluids, etc. It is known [1. J. Kennedy. Cationic polymerization of olefins. M .: Mir, 1978. 430 S .; 2. JP Kennedy, E. Marechal. Carbocationic Polymerization. N.-Y., 1982. 510 P.] that the cationic oligomerization of C ₃ -C ₁₄ olefins can be initiated (catalyzed) using: proton acid catalysts (Bronsted acids); aprotic acids (Lewis acids); alkyl aluminum (or boron) halides; salts of stable carbocations R ⁺ A ^- ; natural and synthetic aluminosilicates, zeolites or heteropoly acids in the H-form; various two- and three-component complexes, including monomer; Ziegler-Natta polyfunctional catalysts; metallocene catalysts; physical methods of stimulating chemical reactions. Catalytic systems including Lewis acids (BF ₃ , AlCl ₃ , AlBr ₃ , TiCl ₄ , ZrCl ₄ , etc.), alkyl aluminum (or boron) halides R _n MX have found the widest industrial application as catalysts for the cationic oligomerization of olefins and other monomers. _3-n (where R is alkyl C ₁ -C ₁₀ -, aryl, alkenyl and other groups; M-Al or B; X-Cl, Br, I) and natural or synthetic aluminosilicates, zeolites and heteropoly acids in H- form. In the preparation of motor PAOMs based on linear alpha-olefins (LAO) C ₃ -C ₁₄ (mainly based on decene-1), catalytic systems are usually used, including Lewis acids or alkylaluminium halides.

So, there are a large number of modifications of the oligomerization catalysts of LAO C ₆ -C ₁₄ , including boron trifluoride and various proton donor cocatalysts - water, alcohols, carboxylic acids, carboxylic acid anhydrides, ketones, polyols and mixtures thereof [3-20] [3. Pat. US 3780128 dated 12/18/1973; Ml C 07 C 5/02; Nkl 585-12; 260-683.9; 4. Pat. U.S. 3997621 dated 12/14/1976; Ml C 07 C 3/18; Nkl 585-255; 260-683.15V; 5. Pat. USA 4,032591 dated 06/28/1977; Ml C 07 C 5/24, 5/18; Ml 585-643; 260-683.65; 6. Pat. USA 4,376,222 of March 8, 1983. Ml C 07 C 2/74; Nkl 585/255; 7. Pat. U.S. 4,225939 from 09/30/1980; Ml C 07 C 3/18; Nkl 585/525; 8. Pat. US 4263465 dated 04/21/1981; Ml C 07 C 9/00; Nkl 585/18; 9. Pat. US 4263467 dated 04/21/1981; Ml C 07 C 9/00; Nkl 585/18; 10. Pat. USA 4 409415 dated 10/11/1983. Ml C 07 C 3/02; Nkl 585/525; 11. Pat. U.S. 4 956512 dated 09/11/1990. Ml C 07 C 2/024; Nkl 585/521; 12. Pat. USA 4 436947 dated 03/13/1984. Ml C 07 C 3/18; Nkl 585/525; 13. Pat. U.S. 4 4,51689 dated May 29, 1984. Ml C 07 C 3/0; Nkl 585/525; 14. Pat. U.S. 4 454366 dated 06/12/1984. Ml C 07 C 7/12; Nkl 585/525; 15. Pat. USA 4 587368 dated 05/06/1986. Ml C 10 L 1/16; C 07 C 2/02; Nkl 585/12; 16. Pat. U.S. 4910355 dated 03/20/1990. Ml C 07 C 2/74; Nkl 585/255; 17. Pat. U.S. 5,254,784 of 12/20/1991. Ml C 07 C 2/22; Nkl 585/525; 18. Pat. USA 5 191140 dated 03/02/1993. Ml C 07 C 2/02; Nkl 585/525; 19. Pat. U.S. 5420373 dated 05/30/1995. Ml C07 C 2/08; Nkl 858/525; 20. Pat. US 5550307 dated 08/27/1996. Ml C 07 C 2/14; Nkl 585/525.]. The oligomerization of olefins With ₃ -C ₁₄ under the action of these catalysts is carried out at temperatures of 20-90 ^o C in bulk for 2-5 hours. The concentration of boron trifluoride in the reaction medium varies from 0.1 to 10 wt.%. The conversion of the starting olefins varies from 80 to 99 wt.%. As a result of oligomerization, for example, decene-1, a mixture of di-, tri-, tetramers and higher molecular weight oligomers is formed. The total content of di- and trimers in the products varies from 30 to 80 wt.%.

 The main disadvantage of all cationic catalysts of this type is that they include scarce, volatile, toxic, corrosive boron trifluoride.

 In addition, the activity of catalysts of this type in the process of LAO oligomerization is relatively low, due to which oligomerization proceeds within 2-5 hours. In the industrial implementation of these processes, expensive large-volume and metal-intensive mixing reactors are used in an anticorrosive design. It is known [21-32] [21. Pat. U.S. 3,725,498 of 04/03/1973. Ml C 07 C 3/18; Nkl 585-532; 22. Pat. USA 3952071 from 04/20/1976. Ml C 07 C 3/18; Nkl 585-532; 23. Pat. USA 3 997622 dated 12/14/1976. Ml C 07 C 3/18; Nkl 585-532; 24. Pat. U.S. 3 997623 dated 12/14/1976; Ml C 07 C 3/18; Nkl 585-532; 25. Pat. U.S. 4 006199 02/01/1977. Ml C 07 C 3/18; Nkl 585-532; 26. Pat. USA 4 031158 from 06/21/1977. Ml C 07 C 3/18; Nkl 585-532; 27. Pat. USA 4 031159 from 06/21/1977. Ml C 07 C 3/18; Nkl 585-532; 28. Pat. U.S. 4,066,715 dated Jan. 3, 1978. Ml C 07 C 3/18; Nkl 585-532; 29. Pat. U.S. 4113790 dated 09/12/1978. Ml C 07 C 3/10; Nkl 585-532; 30. Pat. U.S. 4167534 dated 09/11/1979. Ml C 07 C 5/04; Nkl 585-532; 31. Pat. U.S. 4219691 dated 08/26/1980. Ml C 07 C 3/18; Nkl 585-532; 32. Pat. U.S. 5196635 dated 03/23/1993. Ml C 07 C 2/22; Nkl 585-532] also a large number of cationic catalysts for the oligomerization of olefins, including aluminum halides and proton donors — water, alcohols, carboxylic acids, ethers or esters, ketones (for example, ethylene glycol dimethyl ether, ethylene glycol diacetate, diethyl malonate), haloalkyls [28, 32] 28. Pat. U.S. 4,066,715 dated Jan. 3, 1978. Ml C 07 C 3/18; Nkl 585-532; 32. Pat. U.S. 5196635 dated 03/23/1993. Ml C 07 C 2/22; Nkl 585-532]. In some cases, these catalysts are used in combination with nickel compounds [33. Pat. U.S. 5,489721 dated 02/06/1996. Ml C 07 C 2/20; Nkl 585-532]. The addition of nickel compounds to these catalysts provides for the regulation of the fractional composition of the obtained oligoolefins.

Oligomerization of alpha (C ₄ -C ₁₄ ) or internal C ₁₀ -C ₁₅ olefins (obtained by dehydrogenation of paraffins) [29. Pat. U.S. 4113790 dated 09/12/1978. Ml C 07 C 3/10; Nkl 585-532] carried out under the influence of catalysts AlX ₃ + protonodonor at temperatures of 100-140 ^o C for 3-5 hours. The concentration of AlX ₃ varies from 0.1 to 10 mol% based on olefins, the molar ratio of protonodonor / Al varies from 0.05 to 1.25. With an increase in this ratio from 0.05 to 1.25, the conversion of olefins decreases from 99 to 12 wt.%.

Catalysts of this type are characterized by the following general disadvantages:
- a complex cooking procedure, including many operations - sublimation and grinding AlCl ₃ , preparation of the complex;
- complexes are viscous, sticky substances, poorly soluble in olefins, there are problems with unloading them from the reactor during oligomerization;
- low activity in the process of oligomerization, which requires the use of large-volume metal-intensive mixing reactors;
- high flow rates for AlX ₃ in relation to products;
Under the action of catalysts of this type, mainly high molecular weight and highly viscous products are formed. When carrying out oligomerization of olefins under the action of catalysts based on A1X3, there are difficulties in controlling the fractional composition of oligomers. Many bifunctional complex catalysts have been developed, including transition metal compounds (TiCl ₄ , ZrCl ₄ ) and alkyl aluminum halides R _n AlX _3-n (see, for example, [34-46]. [34. US Pat. No. 4,214,112 of 07/22/1980. Ml. C 07 C 3/18; Nl. 585-532; 35. J. Skupinska. Oligomerization of alpha-olefins to higher oligomers // Chem. Rev. 1991. V. 91. N 4. P.613-648; 36. U.S. Patent 3,168,588. 03/12/1975 Mcl. C 07 C 2/22; Nl. 260-683.15; 37. U.S. Pat. 3,884,988. 05/20/1975. Ml. C 07 C 3/10; Nl. 584-524; French Application 2221467. 1974. Ml. C 08 F 1/32, 15/40; 38. US Pat. No. 4,384,089. Ml. C 07 F 4/64; Nl. 526-159; 39. US Pat. 4,510,342. 09.04 .1985. Ml. C 07 C 3/02; Nl. 584-524; 40. Pat. US 4579991. 04/01/1986. Ml. C 07 C 2/22; Nl. 585-524; 41. US Pat. 4855526. 08/08/1989. Ml. C 07 C 2/02; Nl. 585-524; 42. Pat. UK 1,430,497. Ml. C 07 C 2/22; Ml. UK 1522129. Ml. C 07 C 2/22 Nl. C3P; 43. A.S. USSR 1073279. Ml. C 07 C 2/32; Nl. C 10 M 3/12; 44. Japanese Pat. 52-11350. 1977 (RZhKhim. 1978. 2C270P), Mkl. C 08 F 10/14; 45. A.S. USSR 1075500.17.03.1982. Ml C 07 C 2/22. Nkl B 01 J 31/14; 46. A.S. USSR 1192346. 08/12/1983. Ml C 07 C 2/22. Nkl C 10 M 107/02]). In the catalysts of this type, two types of active sites are formed - cationic and anionic coordination. Because of this, the oligomerization of C ₃ -C ₁₄ olefins under the action of cationic active centers in almost all cases is accompanied by the polymerization of C ₃ -C ₁₄ olefins under the action of anion-coordination active centers into insoluble high molecular weight polyolefins insoluble from the reactor. Under the action of bifunctional complex catalysts in all cases, high molecular weight, highly viscous oligoolefins are formed, which cannot be used as the basis for the most widely consumed motor oils. This is a major disadvantage of this type of catalyst. In addition, catalytic systems of this type, as well as the previously mentioned classical cationic catalysts, have relatively low activity, which requires, as already noted, the use of large-volume metal-intensive low-performance mixing reactors in industrial conditions.

In cationic processes of polymerization, oligomerization and alkylation, two-component soluble monofunctional catalytic systems are also widely used, including the alkylaluminum halide R _n AlX _3-n and the organohalogen compound R'X (where R-CH ₃ , C ₂ H ₅ , C ₃ H ₇ or iso- C ₄ H ₉ ; X - chlorine, bromine or iodine; n = 1.0; 1.5 or 2.0; R '- H [47. US Pat. No. 4,952,739. 08/28/1990. Ml C 07 C 2/18; Nl. 585 / 18; 585/511], primary, secondary or tertiary alkyl, allyl or benzyl [48-51] [48. US Pat. No. 4,041,098. 08/09/1977. Ml C 07 C 3/10; Nl. 585-524; 49 Patent UK 1535324, 1535325. 1978. Ml. C 07 C 3/21; Nl. B1E, C5E; 50. 3rd ka Germany 2526615. 06/13/1975. Ml. C 07 C 3/21; Pat. Germany 2304314. 1980. Ml. C 08 F 110/20; 51. A.S. USSR 1723101. 04/20/1989. Ml. C 07 C 2/30. Nl. C 10 M 107/10]) with a molar ratio R'X / R _n AlX _3-n , = 1.0-5.0. In catalytic systems of this type, R _n AlX _3-n is the basis of the catalyst, and R'X is the cocatalyst.

The catalytic systems R _n AlX _3-n- R'X are used to initiate cationic oligomerization of individual or linear alpha olefin mixtures from propylene to tetradecene, inclusive into the bases of synthetic polyalpha-olefin oils in the environment of the initial olefins or mixtures thereof with oligomerization products and paraffinic or aromatic hydrocarbons at temperatures up to 250 ^o C.

Cationic active sites ([R ^{, +} (R _n AlX _4-n ) ^- ] and R ^{, +} ) in the catalytic systems R _n AlX _3-n- R'X are formed in accordance with the following simplified scheme:
R _n AlX _3-n + R'X <--> [R ^{, +} (R _n AlX _4-n ) ^- ] <--> R ^{, +} + (R _n AlX _4-n ) ^-
The formation of cationic active centers in the considered catalytic systems occurs at a very high speed. Due to this, immediately after mixing the solutions of the components of the considered catalytic systems, a high concentration of cationic active centers is achieved and the oligomerization process proceeds without an induction period at a very high initial rate. Moreover, 95-98 percent conversion of the starting olefins to oligomeric products at temperatures of 20-200 ^o C is achieved within six to one minutes, respectively. This nature of the kinetics of oligomerization of linear alpha-olefins (LAO) under the action of the considered catalytic systems makes it possible to conduct the oligomerization process in a forced mode in tube-type displacement reactors with residence times from 1 to 6 minutes [51. A.S. USSR 1723101. 04.20.1989. Ml C 07 C 2/30. Nkl With 10 M 107/10], but complicates the removal of the released heat of oligomerization.

 During the oligomerization of LAO under the influence of these catalytic systems in the bulk or in the environment of paraffin hydrocarbons, highly branched oligomers freezing at low temperatures are formed containing one di-, tri- or tetraalkyl-substituted double bond, and during oligomerization in the medium or in the presence of aromatic hydrocarbons (benzene, toluene , naphthalene) oligoalkyl aromatic oily products (telomeres) are formed that do not contain double bonds [51. A.S. USSR 1723101. 04.20.1989. Ml C 07 C 2/30. Nkl C 10 M 107/10].

The main disadvantage of the catalytic systems R _n AlX _3-n- R'X is that their use in the process of oligomerization of LAO (in particular decene-1) leads to the formation of predominantly high molecular weight products with a wide molecular weight distribution and with a low (less than 20 wt. .%) the content of the target low molecular weight fractions (dimers and trimers of decene-1) (table 1).

Another disadvantage of catalytic systems of this type is that the decen-1 dimers formed under their action are linear and after hydrogenation have a pour point exceeding -20 ^o C.

The third disadvantage of the catalytic systems R _n AlX _3-n- R'X is that they include a combustible self-igniting in air, which is dangerous during production, during transportation and when using the organoaluminum compound R _n AlX _3-n .

 The closest to the catalytic systems developed in accordance with the present invention for cationic polymerization, oligomerization, telomerization of olefins and alkylation of aromatic hydrocarbons by olefins are catalytic systems comprising aluminum metal. Aluminum metal itself is not a catalyst for the processes mentioned. To provide these systems with catalytic activity, aluminum is usually used in combination with a cocatalyst.

In accordance with [52. Pat. England 868607. Ncl. 2/3 Century 1960] as a cocatalyst use dry hydrogen chloride. A catalyst for the alkylation of benzene with olefins is obtained by reacting aluminum metal with gaseous hydrogen chloride in a mixture of benzene with alkylbenzenes in the absence of olefin. During the reaction, triple arene complexes of aluminum trichloride are formed, which are inactive during the oligomerization of olefins: HCl • (arene) _x • AlCl ₃ .

 The disadvantage of such a catalytic system and the method of its preparation and use is that in order to avoid intense corrosion of the equipment under the influence of hydrochloric acid, carefully dried reagents must be used. Another disadvantage of the considered catalytic system and the method of its preparation and use is that the interaction of aluminum metal with dry hydrogen chloride proceeds slowly (for 2-3 hours or more) and only at elevated temperatures. This excludes the possibility of preparing cationic active centers by reacting aluminum with hydrogen chloride directly in the process of oligomerization of olefins.

 Also known are catalytic systems for the polymerization, oligomerization and telomerization of olefins, as well as the alkylation of aromatic hydrocarbons with olefins, including metallic aluminum and an organo-halide compound [53-60] [53. A. S. USSR 541494. Nkl. At 01 J 37/00. 1975; 54. Pat. US 3303230. Ncl. 260-671. 1967; 55. Pat. US 3,343,911. 260-683.15. 1969; 56. A.S. USSR 430581. Ml. C 07 C 3/10. 1974; 57. A.S. USSR 732229. Ml. S 07 S 15/02. 1975; 58. A.S. USSR 732003. Nl. At 01 J 37/00. 1977; 59. A.S. USSR 1031046. Ncl. At 01 J 37/00. 1977; 60. A.S. USSR 803200. Nkl. B 01 J 31/14. 1979].

 The closest in technical essence and the achieved effect to the catalytic systems developed in accordance with the present invention is a catalytic system for oligomerization and polymerization of olefins, including metal aluminum and carbon tetrachloride (cocatalyst) (prototype composition of the catalytic system) [60. A.S. USSR 803200. Nkl. B 01 J 31/14. 1979].

A known method of preparing a catalyst for oligomerization and polymerization of olefins by reacting aluminum metal with carbon tetrachloride at temperatures of 40-80 ^o With a mass ratio of aluminum to carbon tetrachloride equal to 1: (20-80) in a medium of carbon tetrachloride in the absence of olefins in an inert atmosphere (prototype for the method of preparation and use of the catalyst for oligomerization of olefins) [60. A. S. of the USSR 803200. Ncl. B 01 J 31/14. 1979]. In accordance with this method, first, in the absence of olefins in an inert atmosphere (nitrogen or argon), a solid black product of unknown composition is obtained, which is further used as a catalyst for oligomerization of alpha-olefins and polymerization of isobutylene.

 The disadvantage of the catalytic system of the prototype is the use in its composition of carbon tetrachloride with a high ratio of chlorine to aluminum. This leads to the ingress of a large amount of chlorine difficult to remove from the composition of the products.

 Another disadvantage of the catalytic system of the prototype [60. A. S. USSR 803200. Nkl. B 01 J 31/14. 1979] is its low activity, low productivity and low selectivity for the target fractional composition of the products.

The disadvantage of the method of preparation and use of the catalyst for the oligomerization of olefins and the polymerization of isobutylene from aluminum and an organohalogen compound (CCl ₄ ) is its multi-stage and high complexity.

The main objective of the present invention was the development of an improved catalytic system for the cationic oligomerization of linear alpha-olefins (LAO) C ₃ -C ₁₄ , which would be characterized by increased activity and increased productivity, would provide increased control over the oligomerization process, in particular, would allow to regulate the speed of oligomerization, to increase the yield of the target low molecular weight fractions of oligomers (for example, dimers and trimers of decene-1), to increase the branching of the oligomer product chain and to lower their pour point, and also would increase the safety of its use in the process of oligomerization of olefins.

 In addition, the objective of the invention was to simplify the technology of preparation and use of a catalytic system for the oligomerization of olefins, including metal aluminum.

 In the objective of the present invention, it was envisaged to expand the available raw material base for the acquisition of the main (preferred) and alternative variants of catalytic systems for the oligomerization of olefins of this type.

The problem is solved in that the catalytic system for the cationic oligomerization of individual or mixtures of linear C ₃ -C ₁₄ olefins into the bases of synthetic polyalpha-olefin oils contains aluminum (catalyst base) and cocatalyst, in which, according to the invention (claim 1), it contains an organic halide compound RX, in which R is primary, secondary or tertiary alkyl, allyl, benzyl, acetyl or benzoyl, and X is chlorine, bromine or iodine (claim 1), for each g-aluminum atom contains from 1 to 50 (preferably from 1.5 to 5.0) moles of the halide of the organic compound.

 For a combination of technical, economic and environmental reasons, catalyst systems are preferred which contain, as an organochloride compound RX (claim 2), tert-butyl chloride (TBH), allyl chloride (AX), benzyl chloride (BX), acetyl chloride or benzoyl chloride. In the series of these compounds, according to physicochemical properties, TBH and AX are most suitable. All mentioned organochlorine compounds (unlike carbon tetrachloride) contain fragments with weak highly reactive chlorine-carbon bonds. Such bonds easily and with high speed react with aluminum at low temperatures, which leads to the formation of cationic active centers and the initiation of cationic oligomerization of olefins.

 The catalyst systems of the present invention may contain aluminum in the form of alloys, for example, with magnesium or titanium (paragraph 3). In this case, aluminum or its alloys in the developed catalytic systems are contained (paragraph 4) in the form of materials (bodies) with a developed surface (powder, dispersed spherical or flat particles (for example, ASD-4 aluminum), flakes, rods, wire, grids or plates .

 Aluminum is among the highly active metals. Therefore, it is easily oxidized by atmospheric oxygen. At the same time, a dense film (shell) of aluminum oxide is formed on the surface of the mentioned aluminum materials, which prevents the complete oxidation of aluminum to aluminum oxide. This film also dramatically slows down other reactions of aluminum with highly active reagents (including the reaction of aluminum with halogen organic cocatalysts). It is noted that the more developed the surface of aluminum materials (i.e., the higher the dispersion of aluminum particles), the more noticeably the inhibitory effect of the aluminum oxide film (shell) on the reaction of aluminum with highly active reagents. This (sometimes undesirable) property of aluminum is eliminated by activation of aluminum (destruction of the aluminum oxide film).

 To date, many ways to activate aluminum have been developed. Conventionally, they can be divided into chemical, physical and mechanical. In accordance with the present invention (paragraph 5), aluminum is chemically activated. To ensure the chemical activation of aluminum, the catalytic system according to the present invention (paragraph 5) further comprises an aluminum chemical activator selected from the group of substances including iodine, bromine, ethyl bromide, titanium tetrachloride, vanadium trichloride, tin tetrachloride, ethyl aluminum sesquichloride, ethyl aluminum dichloride and aluminum trichloride from 1 to 25 wt.%, as well as tert-butyl chloride, allyl chloride, benzyl chloride, benzene and toluene - in an amount of from 10 to 200 wt.% calculated on aluminum.

The activating effect of iodine, bromine, ethyl bromide, titanium tetrachloride, vanadium trichloride, tin tetrachloride, ethyl aluminum sesquichloride, ethyl aluminum dichloride and aluminum trichloride is caused by the partial or complete destruction (dissolution) of the aluminum oxide film under the action of these substances. In the same way, at elevated temperatures, aluminum also activates with haloalkyls - tert-butyl chloride, allyl chloride and benzyl chloride. In this case, tert-butyl chloride, allyl chloride and benzyl chloride combine the functions of both an aluminum activator and a reagent, which forms the basis of cationic active centers and cocatalyst with aluminum. Benzene and toluene alone cannot activate aluminum. The activating effect of these compounds is apparently due to the fact that, with the catalytic assistance of alumina, benzene and toluene are slowly alkylated with a co-catalyst — an organic halide, resulting in the formation of hydrogen chloride (RCl + C ₆ H ₆ + Al ₂ O ₃ Hcl + R-C ₆ H ₅ + Al ₂ O ₃ ), which dissolves the alumina film and thus activates aluminum.

Al ₂ O ₃ + 6CHl -> 2 AlCl ₃ +3 H ₂ O
Subsequent reactions of aluminum with an organ halide cocatalyst have not yet been studied. By analogy with the Würz and Grignard reactions, it can be assumed that the reactions of purified Al with RX first lead to the formation of alkyl aluminum sesquihalogenide (AACX), and then to the carbonic salt AACX:
3RCl + 2Al -> 2R _1.5 AlCl _1.5
R _1.5 AlCl _1.5 + RCl -> R ⁺ [R _1.5 AlCl _2.5 ] ^- (I)
The molecules of carbonium salt (I) formed in this way are precisely the active centers of cationic oligomerization of olefins.

In accordance with the present invention (paragraph 6), a catalytic system is prepared by reacting aluminum metal with an activator and cocatalyst in an inert atmosphere directly during oligomerization in an environment of oligomerizable olefins or mixtures thereof with oligomerization products (e.g., dimers, trimers, etc.) and added paraffinic or aromatic hydrocarbons at temperatures from 10 to 150 ^o C in mixing reactors of capacitive type for 10-60 minutes. In batch reactors, the activator and cocatalyst completely dissolve the aluminum. The concentration of the formed soluble aluminum compounds varies from 10 to 80 (preferably 30-40) mmol / L.

 Capacitive continuous type mixing reactors with intensive mixing of the contents are close in their characteristics to ideal mixing reactors, which are characterized in that at any point in time at any point in the reactor the concentrations of all reagents and products will be equal. As applied to the continuous processes of oligomerization of olefins under the action of catalytic systems, including finely dispersed aluminum metal, an activator of aluminum and a cocatalyst, this means that some of the aluminum particles will not have time to react with other catalyst components and will be removed from the reactor in the initial state. This will lead to a decrease in the specific productivity of the catalysts.

 In accordance with the present invention (paragraph 7), the oligomerization of olefins in a continuous mode is carried out in a cascade of at least two series-connected mixing reactors. The second mixing reactor performs the function of a ripener, in which the particles of aluminum removed from the first reactor are converted into cationic active centers.

 Activated aluminum and its reaction products with an activator and cocatalyst are among the highly reactive substances that are easily oxidized by atmospheric oxygen. Therefore, the preparation of olefin oligomerization catalysts is carried out in an inert atmosphere. As an inert atmosphere in accordance with the present invention (claim 8), not only nitrogen or argon is used, as in the prototype, but also carbon dioxide at an absolute partial pressure of carbon dioxide equal to 1.0-10.0 (preferably 1.0-1.5) atmospheres. For the same reason, the oligomerization of olefins in accordance with the present invention (claim 9) is carried out in a carbon dioxide atmosphere at an absolute partial pressure of carbon dioxide equal to 1.0-10.0 atmospheres.

 Testing of catalytic systems during the cationic oligomerization of decene-1 and other olefins was performed as follows.

A sample of aluminum metal was charged into a thermostatically controlled, cleaned and dried batch type batch reactor with an stirrer in an inert atmosphere at ambient temperature (15-25 ^° С), and the reactor was deaerated with a vacuum pump to a residual pressure of at least 0.01 mm Hg. Art., olefin (in some cases, an aromatic hydrocarbon) was charged from the measuring tanks (reactor filling factor ≅50 vol.%), with the aid of a calibrated syringe, solutions of aluminum soluble in organic solvents activator and organohalogen compounds R'X were added thereto with stirring, carbon dioxide was fed from the calibrated can into the reactor until an absolute pressure of 1.5 atmospheres was reached; Using a thermostat, the reactor and its contents were heated to a predetermined temperature. Following this (usually immediately), olefin oligomerization began, which was accompanied by a marked increase in the temperature of the reaction medium (oligomerizate). The reaction was continued for the scheduled time, and then terminated by introducing into the reactor an aqueous solution of alkali (NaOH) or ethanol. The resulting oligomerizate from the reactor was further discharged into an intermediate tank. Spent (deactivated) catalyst from the oligomerizate was isolated by the adsorption method or by the method of water-alkaline and water washing.

The temperature entering the reactor flows corresponded to the ambient temperature (15-25 ^o C). In some cases, the solutions of the catalyst components were heated to a predetermined temperature before being fed to the reactor. At the moment of contacting the solutions of the components of the catalyst components entering the reactor with metal aluminum, cationic active centers formed with a very high speed and olefin oligomerization began. Oligomerization proceeded at a high rate and with the release of a large amount of heat (ΔН) (ΔН = 22 [1-1 / P _n ] kcal / mol of the converted olefin, where P _n is the number average degree of oligomerization of the olefin). The released heat of oligomerization was removed from the reaction zone with a coolant (usually water) through the shirts of the said reactors.

 The collection batch was a stirred tank reactor, where oligomerization of the unconverted olefin continued for another 60 minutes. The presence of the oligomerizate in the collection batch contributed to an increase in the conversion of the initial olefin by 3-10 wt.% Compared with the case when the oligomerizate was immediately sent for purification. From the collection compartment, the oligomerizate was sent to a washer or to an adsorber.

The washer was used to isolate spent catalyst by the method of water-alkaline and then water washing (purification) of the oligomerizate. It functioned periodically and consisted of a thermostatically controlled (heated) reactor with a stirrer, into which oligomerizate, a 5% aqueous solution of NaOH or NH ₃ , and then fresh demineralized water were fed from auxiliary measuring tanks. In some cases, the oligomerizate entered the washer directly from the oligomerization reactor.

 The adsorber was a thermostatically controlled column apparatus filled with activated calibrated particles of aluminum oxide or bauxite. With the passage of the oligomerizate (bottom-up) through the layer of the indicated adsorbent, a frontal adsorption of spent deactivated catalyst and purification of the oligomerizate occurred.

 After sampling for analysis, the purified oligomerizate was loaded into a cube of a vacuum column for subsequent azeotropic drying, isolation of unconverted olefins, and for separation of the oligomer into fractions.

The fractional composition of oligomerization products was determined by the standard chromatographic method (using LHM 8-MD devices, Hewlet Packard Model 5710 A) and / or the fractionation method on a vacuum distillation column. The results of these analyzes coincided with an accuracy of ± 2 wt.%. The structure of the isolated products was quantitatively determined by ozonolysis using an ADS-2, IKS, ¹ H NMR and ¹³ C-NMR instrument.

 For a better understanding of the present invention, as examples, tables 1-7 show examples of compositions of catalyst systems developed according to the invention for cationic oligomerization of olefins; describes the method of their preparation, the method of oligomerization (using the developed catalysts) and the results of their testing in the process of oligomerization of decene-1 and other olefins, as well as the yield, structure and properties of the target oligo-olefin fractions isolated from olefin oligomerization products. These examples demonstrate but do not exhaust the scope of the invention.

Comparison of the test results of the catalytic systems A1 - activator - RX developed according to the invention (Table 2-7) with the test results of the known catalytic systems R _n AlX _3-n- R'X (table 1) and AlX ₃ -OM (organic modifier) (according to analogues) in the process of oligomerization of decene-1 allows us to draw the following general conclusions:
1. The Al - activator - RX catalytic systems developed in accordance with the present invention function most efficiently at temperatures of 20-125 ^° C, Al concentrations of 0.02-0.08 mol / L, and molar ratios of RC1 / A1 = 1.0-5.0 when specified in the description and examples the consumption of activators and at the same time provide 80-99 percent conversion of olefins (including decen-1) to oligomers within 10-60 minutes;
2. The additional inclusion of aluminum activators listed in the description and in the formula of the present invention in the Al-RX catalyst systems provides increased process control: eliminates the induction period, simplifies the removal of heat from oligomerization, and eliminates uncontrolled strong heating of the reaction mixture (Q = 22 [1-1 / P _n ], kcal / mol converted to the oligomer LAO) and provides a more homogeneous composition of the oligomers. On the other hand, the activity and productivity of the Al-activator-RX catalyst systems developed according to the invention significantly exceeds the activity and productivity of the Al-CCl ₄ catalyst system (according to the prototype). The use of the Al - activator - RX catalyst systems developed according to the present invention in the decene-1 oligomerization process allows to reduce the reaction time from 2-3 hours in the case of the Al-CCl _{4 system} to 10-60 minutes - in the case of the Al - activator catalyst systems developed according to the invention - RX.

 3. The use of the catalytic systems developed according to the invention in the decene-1 oligomerization process made it possible to increase the partial yield of the target low molecular weight oligodecene fractions (dimers and trimers of decene) up to 40-50 wt.% Calculated on the starting decen-1 (up to 60 wt.% Calculated decen-1, converted into oligomers) and reduce to 10-20 wt.% the content in the oligomerizate of high molecular weight oligodecenes.

 4. The structure and physicochemical properties of di-, tri-, and other oligomeric fractions of oligodecenes allow their use as the basis for synthetic poly alpha olefin oils (PAOM-2, PAOM-4, PAOM-6, PAOM-10, PAOM-14 etc.).

 5. Developed according to the invention, methods for the preparation and use of catalytic systems in the process of oligomerization in an atmosphere of carbon dioxide can improve the technical and economic indicators of the production technology of PAOM.

 The advantages of the Al-activator-RX catalytic systems developed according to the invention, including many variants of available components, over the known catalytic systems are that they combine high activity, high specific productivity, high selectivity for the target products, versatility with respect to olefin feed and while providing targeted products with lower pour points.

Claims (10)

1. The catalytic system for the cationic oligomerization of individual or mixtures of C ₃ -C ₁₄ olefins into the base of synthetic polyalpha-olefin oils, containing active aluminum and cocatalyst, characterized in that as a cocatalyst it contains an organic halide compound RX, in which R is primary, secondary or tertiary alkyl, allyl, benzyl, acetyl or benzoyl, and X is chlorine, bromine or iodine, and for each g-atom of aluminum it contains 1-50 moles of an organohalogen compound.  2. The catalytic system according to claim 1, characterized in that it contains tert-butyl chloride, allyl chloride, benzyl chloride, acetyl chloride or benzoyl chloride as the organohalogen compound RX.  3. The catalytic system according to paragraphs. 1 and 2, characterized in that for each g-atom of aluminum it contains 1.5-5.0 moles of an organohalogen compound.  4. The catalytic system according to paragraphs. 1-3, characterized in that it contains aluminum in the form of alloys, for example, with magnesium or titanium.  5. The catalytic system according to paragraphs. 1-4, characterized in that the aluminum or its alloys it contains in the form of materials with a developed surface, which are selected from powder, dispersed spherical or flat particles, wire, nets or plates.  6. The catalytic system according to paragraphs. 1-5, characterized in that it further comprises an aluminum activator selected from the group of substances including iodine, bromine, ethyl bromide, titanium tetrachloride, vanadium trichloride, tin tetrachloride, ethyl aluminum sesquichloride, ethyl aluminum dichloride and aluminum trichloride in an amount of 1-25 wt. %, as well as tert-butyl chloride, allyl chloride, benzyl chloride, benzene and toluene in an amount of 10-200 wt. % calculated on aluminum. 7. The method of preparation of the catalytic system according to paragraphs. 1-6 by the reaction of aluminum with an activator and cocatalyst in a solvent in an inert atmosphere, characterized in that the interaction of aluminum with an activator and cocatalyst RX is carried out directly in the process of oligomerization in an environment of oligomerizable olefins or mixtures thereof with oligomerization products and paraffinic or aromatic hydrocarbons at 10 150 ^o C for 10-60 minutes  8. The method according to p. 7, characterized in that the preparation of the catalytic system is carried out in an atmosphere of carbon dioxide at an absolute partial pressure of carbon dioxide equal to 1.0-10.0 atmospheres. 9. The method of oligomerization of individual or mixtures of C ₃ -C ₁₄ olefins into the bases of synthetic polyalpha-olefin oils under the action of cationic catalyst systems according to claims 1-6 in continuous mode, characterized in that the oligomerization of olefins is carried out in a cascade of at least two series-connected mixing reactors.  10. The method according to p. 9, characterized in that the oligomerization of olefins is carried out in an atmosphere of carbon dioxide at an absolute partial pressure of carbon dioxide equal to 1.0-10.0 atmospheres.

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