METHOD FOR PREPARING LOW-VISCOSITY LUBRICATING POLYOLEFINS

Abstract

Disclosed is a method for preparing a low-viscosity oil including more than 50 wt % of 9-methyl-11-octyl-heneicosane. The method uses a specific metallocene catalyst and makes it possible to prepare a polyalphaolefin oil (PAO) in which the kinematic viscosity at 100° C., measured according to standard ASTM D445, ranges from 3 to 4 mm.sup.2/s.sup.−1. The oil can be used as a high-performance lubricant for lubrication in the fields of engines, gears, brakes, hydraulic fluids, coolants and greases

Claims

1-18. (canceled)

19. A method for preparing an oil with a kinematic viscosity at 100° C., measured according to the ASTM D445 standard, ranging from 3 to 4 mm.sup.2.Math.s.sup.−1, comprising more than 50% by weight of a 1-decene trimer of formula (I), ##STR00003## comprising oligomerization of 1-decene in the presence of hydrogen (H.sub.2), of a metallocene catalyst and of an activator compound or in the presence of hydrogen (H.sub.2), of a metallocene catalyst, of an activator compound and of a co-activator compound; catalytic hydrogenation of the oligomerization products in the presence of hydrogen (H.sub.2) and of a hydrogenation catalyst; separation by distillation at reduced pressure of the fraction of trimers comprising more than 50% by weight of the 1-decene trimer of formula (I).

20. The method according to claim 19 comprising a final hydrogenation step of the fraction of trimers comprising more than 50% by weight of the 1-decene trimer of formula (I), in the presence of hydrogen (H.sub.2) and of a hydrogenation catalyst.

21. The method according to claim 19 comprising the recycling of the fraction of 1-decene dimers (for example 9-methyl-nonadecane), separated by distillation at reduced pressure and oligomerization of this fraction of this recycled fraction of 1-decene dimers with 1-decene, in the presence of hydrogen (H.sub.2), of a metallocene catalyst and of an activator compound or in the presence of hydrogen (H.sub.2) of a metallocene catalyst, of an activator compound and of a co-activator compound.

22. The method according to claim 19 comprising the deactivation of the catalyst after oligomerization of 1-decene and after catalytic hydrogenation of the oligomerization products.

23. The method according to claim 19 comprising the preliminary preparation of 1-decene by catalytic oligomerization of ethylene.

24. The method according to claim 19 wherein the oligomerization of 1-decene is achieved in the presence of hydrogen (H.sub.2), of a metallocene catalyst, of an activator compound and of a co-activator compound.

25. The method according to claim 19 wherein the metallocene catalyst is a racemic compound of formula (II)
L(Q.sup.1)(Q.sup.2)MR.sup.1R.sup.2   (II) wherein M represents a transition metal selected from among titanium, zirconium, hafnium, and vanadium or represents zirconium; Q.sup.1 and Q.sup.2, either substituted or non-substituted, independently represent a tetrahydroindenyl cyclic group or Q.sup.1 and Q.sup.2 independently represent a tetrahydroindenyl cyclic group and are bound in order to form a polycyclic structure; L represents a divalent C.sub.1-C.sub.20 alkyl group bridging Q.sup.1 and Q.sup.2 or L represents a group selected from among methylene (—CH.sub.2—), ethylene (—CH.sub.2—CH.sub.2—), methylmethylene (—CH(CH.sub.3)—), 1-methyl-ethylene (—CH(CH.sub.3)—CH.sub.2—), n-propylene (—CH.sub.2—CH.sub.2—CH.sub.2—), 2-methylpropylene (—CH.sub.2—CH(CH.sub.3)—CH.sub.2—), 3-methylpropylene (—CH.sub.2—CH.sub.2—CH(CH.sub.3)—), n-butylene (—CH.sub.2—CH.sub.2—CH.sub.2—CH.sub.2—), 2-methylbutylene (—CH.sub.2—CH(CH.sub.3)—CH.sub.2—CH.sub.2—), 4-methylbutylene (—CH.sub.2—CH.sub.2—CH.sub.2—CH(CH.sub.3)—), pentylene and isomers thereof, hexylene and isomers thereof, heptylene and isomers thereof, octylene and isomers thereof, nonylene and isomers thereof, decylene and isomers thereof, undecylene and isomers thereof, dodecylene and isomers thereof; R.sup.1 and R.sup.2, either substituted or non-substituted, independently represent an atom or a group selected from among hydrogen, halogens, and alkyls; or R.sup.1 and R.sup.2 form with M a metallocycle comprising from 3 to 20 carbon atoms.

26. The method according to claim 19 wherein the metallocene catalyst is selected from among rac-ethylene bis(tetrahydroindenyl) zirconium dimethyl and rac-ethylene bis(tetrahydroindenyl)zirconium dichloride.

27. The method according to claim 19 wherein the oligomerization of 1-decene is achieved in a period ranging from 2 to 300 mins or from 5 to 180 mins or from 30 to 140 mins; or in the presence of hydrogen (H.sub.2) at a partial pressure ranging from 0.1 to 20 bars or from 1 to 6 bars; or in a hydrogen/1-decene mass ratio greater than 100 ppm or less than 600 ppm or comprised between 100 and 600 ppm; or at a temperature ranging from 50 to 200° C. or from 70 to 160° C. or from 80 to 150° C. or from 90 to 140° C. or from 100 to 130° C.; or in a solvent selected from among a linear or branched hydrocarbon, a cyclic or non-cyclic hydrocarbon, an alkylated aromatic compound and mixtures thereof or in a solvent selected from among butanes, pentanes, hexanes, heptanes, octanes, cyclopentane, cyclohexane, methylcyclopentane, methylcyclohexane, methylcycloheptane, toluene, xylene and mixtures thereof.

28. The method according to claim 19 wherein the activator compound is selected from among an ionic activator and an oligomeric compound comprising residues of formula —Al(R)—O— wherein R represent independently a cyclic or linear C.sub.1-C.sub.20 alkyl group; or the activator compound is selected from among methylalumoxane, modified methylalumoxane, ethylalumoxane, isobutylalumoxane and mixtures thereof; or the activator compound is selected from among dimethylanilinium tetrakis(perfluorophenyl)borate (DMAB), triphenylcarbonium tetrakis(perfluorophenyl)borate, dimethylanilinium tetrakis(perfluorophenyl)aluminate and mixtures thereof.

29. The method according to claim 19 wherein the activator compound is an ionic activator and the co-activator compound is a trialkylaluminium derivative; or the activator compound is an ionic activator and the co-activator compound is a compound selected from among tri-ethyl aluminium (TEAL), tri-iso-butyl aluminium (TIBAL), tri-methyl aluminium (TMA), methyl-methyl-ethyl aluminium (MMEAL) and tri-n-octyl aluminium.

30. The method according to claim 19 comprising deactivation of the catalyst, is carried out by action of air or by action of water or by means of at least one alcohol or a deactivation agent solution.

31. The method according to claim 19 wherein, during the catalytic hydrogenation of the oligomerization products, the hydrogen pressure (H.sub.2) ranges from 5 to 50 bars or from 10 to 40 bars or from 15 to 25 bars; or the hydrogenation catalyst is selected from a derivative of palladium, a derivative of the supported palladium, a derivative of the supported palladium on alumina (for example gamma-alumina), a derivative of nickel, a derivative of supported nickel, a derivative of nickel supported on kieselguhr, a derivative of platinum, a derivative of supported platinum, a cobalt-molybdenum derivative, a supported cobalt-molybdenum derivative.

32. The method according to claim 19 comprising the final hydrogenation of the majority fraction by weight of the 1-decene trimer of formula (I), achieved at a hydrogen pressure (H.sub.2) ranging from 5 to 50 bars or from 10 to 40 bars or from 15 to 25 bars; or within a period comprised between 2 and 600 mins or between 30 and 300 mins; or at a temperature ranging from 50 to 200° C. or from 60 to 150° C. or from 70 to 140° C. or from 80 to 120° C.; or in the presence of a hydrogenation catalyst selected from a derivative of palladium, a derivative of supported palladium, a derivative of supported palladium on alumina (for example gamma-alumina), a derivative of nickel, a derivative of supported nickel, a derivative of supported nickel on kieselguhr, a derivative of platinum, a derivative of supported platinum, a cobalt-molybdenum derivative, a supported cobalt-molybdenum derivative.

33. The method according to claim 19 for preparing an oil comprising from 60 to 90% by weight of the 1-decene trimer of formula (I) or from 70 to 90% by weight of the 1-decene trimer of formula (I); or at least 65% by weight of the 1-decene trimer of formula (I) or at least 70% by weight of the 1-decene trimer of formula (I) or at least 80% by weight of the 1-decene trimer of formula (I) or at least 90% by weight of the 1-decene trimer of formula (I).

34. The method according to claim 19, for preparing an oil also comprising at least one other saturated oligomer of 1-decene selected from among the other trimers of 1-decene; or the dimers of 1-decene, the other trimers of 1-decene, the tetramers of 1-decene, the pentamers of 1-decene; or 9-methyl-nonadecane and 9-methyl-11,13-dioctyl-tricosane.

35. The method according to claim 19, for preparing an oil comprising from 51 to 99.9% by weight of the 1-decene trimer of formula (I) and from 0.1 to 49% by weight of at least one other saturated trimer of 1-decene; or from 70 to 90% by weight of the 1-decene trimer of formula (I) and from 10 to 30% by weight of at least one other saturated trimer of 1-decene; or from 51 to 99.6% by weight of the 1-decene trimer of formula (I); from 0.1 to 1% by weight of at least one saturated dimer of 1-decene (for example 9-methyl-nonadecane); from 0.1 to 25% by weight of at least one other saturated trimer of 1-decene; from 0.1 to 20% by weight of at least one saturated tetramer of 1-decene (for example 9-methyl-11,13-dioctyl-tricosane); from 0.1 to 1.5% by weight of at least one saturated pentamer of 1-decene.

36. The method according to claim 19 for preparing an oil comprising more than 50% by weight of 9-methyl-11-octyl-henicosane for which (a) the kinematic viscosity at 100° C., measured according to the ASTM D445 standard ranges from 3.2 to 3.8 mm.sup.2.Math.s.sup.−1 or is 3.5 mm.sup.2.Math.s.sup.−1; or for which (b) the viscosity index is greater than 120 or greater than or equal to 130 or is comprised between 120 and 140 or between 125 and 135; or for which (c) the volatility measured according to the ASTM D6375 standard is less than 10.8% by mass or less than 10.5% by mass; or for which (d) the dynamic viscosity (CCS) at −35° C., measured according to the ASTM D5293 standard is less than 900 mPa.Math.s or less than 800 mPa.Math.s.

37. The method of claim 25, wherein R.sup.1 and R.sup.2 independently represent a halogen selected from a group consisting of Cl and I.

38. The method of claim 25, wherein R.sup.1 and R.sup.2 independently represent an alkyl selected from a group consisting of Me, Et, nPr and iPr, alkenyl, alkynyl, halogenoalkyl, halogenoalkenyl, halogenoalkynyl, silylalkyl, silylalkenyls, silylalkynyls, germylalkyl, germylalkenyl, and germylalkynyl.

Description

EXAMPLES

[0180] An autoclave reactor equipped with a stirrer, a temperature control system and inlets for introducing nitrogen, hydrogen and 1-decene is used.

[0181] The 1-decene (product of the TCI or Acros company) is used at a purity of more than 94%. It is purified on molecular sieves of 3 Å and 13× (Sigma-Aldrich). Before use, the molecular sieves used are dried beforehand at 200° C. for 16 hours.

[0182] The products are characterized by .sup.1H NMR and by two-dimensional gas chromatography (GCxGC).

[0183] For NMR, the PAO samples were diluted in deuterated chloroform and the NMR spectra were produced at 300 K on Bruker 400 MHz spectrometers: .sup.1H, .sup.13C, HMQC (heteronuclear multiple quantum coherence) and HMBC (heteronuclear multiple bond coherence).

[0184] The two-dimensional chromatography is applied in a continuous mode by means of two apolar and polar columns. The whole of the effluents stemming from the first column is separated in the second dimension. The separation of the compounds is governed by the volatility on the first column and by specific interactions (π-π type, dipolar interactions, etc) on the second dimension. Depending on their viscosity, the samples are generally diluted twice in heptane. The chromatographic conditions were optimized in order to be able to elute the PAOs prepared according to the invention. The samples were analyzed in GC×GC with cryogenic modulation (liquid nitrogen), programing the first oven from 45° C. (5 mins) up to 320° C. (20 mins) with a ramp of 3° C./min, programing of the secondary oven from 60° C. (5 mins) up to 330° C. (20 mins) with a ramp of 3° C./min and columns used according to the following operating conditions: [0185] 1.sup.st dimension: HP1, 25 m, ID 0.32 mm, film thickness: 0.17 μm; [0186] 2.sup.nd dimension: BPX-50, 1.5 m, ID 0.1 mm, film thickness: 0.1 μm; [0187] injector: split 100:1, injected volume: 0.1 μl; [0188] detector: FID, 320° C.; [0189] hot jet temperature: 320° C.; [0190] programing the cold jet from 80 to 5%; [0191] modulation period: 4.8 s.

Example 1

[0192] An 8 L autoclave reactor is used. Before its use, the reactor is dried at 130° C. with a nitrogen flow for one hour and then cooled to 110° C. Next, it is filled with 3,500 mL of 1-decene under a nitrogen flow. The temperature of the reactor is maintained at 110° C. and hydrogen (H.sub.2) is introduced in a H.sub.2/1-decene m/m ratio of 414 ppm.

[0193] The catalyst is the rac-ethylene bis(tetrahydroindenyl) zirconium dimethyl activated with dimethylanilinium tetrakis(perfluorophenyl)borate (DMAB) in a B/Zr molar ratio of 1.75. Triisobutyl aluminium (TiBAl) is used as a co-activator compound in an Al/Zr molar ratio of 200. It gives the possibility of trapping impurities present in the reactor. The oligomerization begins at the moment when the activated catalyst is introduced in a concentration of 17 μM relatively to the oligomerization solution.

[0194] After 120 mins, 5 mL of isopropanol is introduced in order to deactivate the catalyst. Next, one proceeds with hydrogenation of the reaction products by using a catalyst with palladium supported on alumina (5 g of palladium on gamma-alumina at 5% m/m with respect to alumina—the product Alfa Aesar) and hydrogen (H.sub.2) at 20 bars, at a temperature of 100° C. for 240 mins.

[0195] The oligomerization products and the fraction of trimers comprising more than 50% by weight of 9-methyl-11-octyl-henicosane are then separated by distillation at reduced pressure (0.67 mbars (0.5 mmHg)) in two steps according to the ASTM D2892 standard and then according to the ASTM D5236 standard: (1) by means of a column with 15 theoretical plates for which the maximum temperature is 375° C. and then (2) by means of a column with 2 theoretical plates, the temperature of the vapors of which in the column head ranges from 375 to 445° C.

[0196] Distillation according to the ASTM D2892 standard allows separation of the products for which the boiling point is less than 375° C. The distillation according to the ASTM D5236 standard allows isolation of the products for which the boiling point ranges from 375 to 445° C.

[0197] The oil according to the invention obtained has a content of 9-methyl-11-octyl-henicosane equal to 71.4%.

[0198] This oil according to the invention comprising more than 50% by weight of 9-methyl-11-octyl-henicosane has a kinematic viscosity at 100° C., measured according to the ASTM D445 standard, of 3.448 mm.sup.2.Math.s.sup.−1. The viscosity index of this oil is 130. Its volatility measured according to the ASTM D6375 standard is 10.3% by mass and its dynamic viscosity (CCS) at −35° C., measured according to the ASTM D5293 standard, is 780 mPa.Math.s. Its average molecular mass is 372 g/mol.

[0199] The characteristics of the oil according to the invention gives the possibility of obtaining excellent lubricant, rheological and oxidation resistance properties as well as Fuel Eco properties.

Example 2

[0200] One proceeds in an identical way with example 1 for oligomerization of 1-decene.

[0201] The oligomerization products and the fraction of trimers comprising more than 50% by weight of 9-methyl-11-octyl-henicosane are then separated by distillation at reduced pressure (0.67 mbars (0.5 mmHg)) in two steps according to the ASTM D2892 standard and then according to the ASTM D5236 standard: (1) by means of a column with 15 theoretical plates for which the maximum temperature is 375° C. and then (2) by means of a column with 2 theoretical plates for which the temperature of the vapors in the column head ranges from 445 to 465° C.

[0202] The distillation according to the ASTM D2892 standard allows separation of the products for which the boiling point is less than 375° C. The distillation according to the ASTM D5236 standard allows isolation of the products for which the boiling point ranges from 445 to 465° C.

[0203] The obtained oil according to the invention has a content of 9-methyl-11-octyl-henicosane equal to 65.7%.

[0204] This oil according to the invention comprising more than 50% by weight of 9-methyl-11-octyl-henicosane has a kinematic viscosity at 100° C., measured according to the ASTM D445 standard, of 3.640 mm.sup.2.Math.s.sup.−1. The viscosity index of this oil is 132. Its volatility measured according to the ASTM D6375 standard is 9.1% by mass and its dynamic viscosity (CCS) at −35° C., as measured according to the ASTM D5293 standard, is 890 mPa.Math.s. Its average molecular mass is 383 g/mol.

[0205] Again, the characteristics of this oil according to the invention give the possibility of obtaining excellent lubricant, rheological and oxidation resistance as well as Fuel Eco properties.

Example 3

[0206] One proceeds in an identical way with example 1 in order to prepare a first fraction of oil according to the invention. One proceeds in an identical way with example 2 for preparing a second oil fraction according to the invention. Both fractions are then collected.

[0207] Next, one proceeds with the final hydrogenation by using a palladium catalyst (0.5% m/m relatively to H.sub.2) supported on alumina (5 g of palladium on gamma-alumina at 5% m/m relatively to alumina—product Alfa Aesar) and hydrogen (H.sub.2) at 20 bars, at a temperature of 90° C. for 240 mins.

[0208] The obtained oil according to the invention has a content of 9-methyl-11-octyl-henicosane equal to 74.7%.

[0209] This oil according to the invention comprising more than 50% by weight of 9-methyl-11-octyl-henicosane has a kinematic viscosity at 100° C., measured according to the ASTM D445 standard, of 3.569 mm.sup.2.Math.s.sup.−1. The viscosity index of this oil is 130. Its volatility measured according to the ASTM D6375 standard is 10.3% by mass and its dynamic viscosity (CCS) at −35° C., measured according to the ASTM D5293 standard is 720 mPa.Math.s. Its average molecular mass is 378 g/mol.

[0210] Again, the characteristics of the oil according to the invention give the possibility of obtaining excellent lubricant, rheological and oxidation resistance as well as Fuel Eco properties.

Comparative Example 1

[0211] Measurements and identical characterizations were carried out from of a reference commercial oil. This is a PAO oil (the product ExxonMobil Spectrasyn Plus 3.6) prepared from olefins by acid catalysis.

[0212] This reference PAO oil has a kinematic viscosity at 100° C., measured according to the ASTM D445 standard, of 3.671 mm.sup.2.Math.s.sup.−1. Its viscosity index is 118. Its volatility measured according to the ASTM D6375 standard is 14.3% by mass and its dynamic viscosity (CCS) at −35° C., as measured according to the ASTM D5293 standard is 1,100 mPa.Math.s. Its average molecular mass is 374 g/mol.

[0213] Moreover, the specifications of this commercial oil are the following: kinematic viscosity at 100° C., measured according to the ASTM D445 standard, from 3.5 to 3.9 mm.sup.2.Math.s.sup.−1; volatility measured according to the ASTM D5800 standard of less than 17% by mass.

[0214] The method according to the invention therefore gives the possibility of preparing an oil for which the properties are equivalent or greater than the commercial PAO oils, in particular the viscosity index or the dynamic viscosity which are much better for the oils according to the invention.