CA2152669A1

CA2152669A1 - Method for oligomerization of olefins and olefin mixtures

Info

Publication number: CA2152669A1
Application number: CA002152669A
Authority: CA
Inventors: Mika Kapanen; Erkki Halme; Salme Koskimies
Original assignee: Individual
Current assignee: Neste Oyj
Priority date: 1992-12-31
Filing date: 1993-12-15
Publication date: 1994-07-21
Also published as: WO1994015895A1; NO952606D0; CZ166895A3; FI925969A0; FI93828B; EP0677033A1; FI925969A; FI93828C; KR960700206A; JPH08505848A; NO952606L

Abstract

The invention relates to the oligomerization of olefins or olefin mixtures, in particular long-chain hydrocarbon mixtures containing 6-20 carbon atoms or butenes, or mixtures of these said olefins, by means of a BF3/cocatalyst complex, the cocatalyst being water, a C2-C10 monoalcohol or a C2 C10 monocarboxylic acid. Examples of especially preferred cocatalysts are pentanol and n-valeric acid. BF3 is fed in gaseous state into the oligomerization reactor, and the reactor is pressurized thereby. In case a monomer mixture is oligomerized, the product is a true co-oligomer and it also contains double bonds which increase product ractivity, needed when the oligomer is used as an intermediate.

Description

2152fi63 Wo 94/15895 PCT/F193/00~40 Method for oligomerization of olefins and olefin mixtures The present invention relates to a method for the oligomPri7~tion of olefins and olefin 5 Illix.Lul~S by using a boron trifluoride cocatalyst complex.

The oligomerization and polymeri7~tion of various olefins constitute commonly known technology. These reactions may occur thermally without a catalyst; as radical reactions over, for example, peroxide catalysts or coordination polymPri7~tion catalysts; by an 10 anionic mechanism over basic catalysts; by a cationic mech~nicm over Friedel-Crafts catalysts; and by polymerization by using molecular sieves, for example zeolites.

An anionic mech~ni~m is used mainly for olefin r~impri7~til~n reactions, for example, for the ~im~ri7~tion of propylene to 4-methyl-1-pentene. Coordination polymerization is used 15 mainly for the preparation of various pl~ctics~ such as polyethylene, polypropylene, and poly-l-butene, in which it is desirable to determine in advance precisely the structure of the formed product. A c~tionic me~h~nicm and polymeri7~tion by using molecular sieves produce in the polymçri7~tion of olefins only light oligomers or viscous liquids, so-called liquid polymers.
The catalysts used in the c~tionic m~h~nicm have been Lewis acids such as BF3, AlCl3, AlBr3, TiC14, SnC14, etc. It is known that Lewis-acid catalysts cannot alone initiate a polymerization reaction; they require a proton donor, i.e. a cocatalyst. Examples of such cocatalysts are water, alcohols, carboxylic acids, inorganic acids, certain alkyl halides, 25 and halogens. The oligomerization can be carried out in bulk, i.e. without an auxiliary solvent, or in the presence of an inert solvent. FY~mples of such inert solvents are alkanes such as hexane and heptane, and cyclo~lk~nes such as cycloheY~ne and cycloheptane.

BF-catalyzed oligomt-ri7~tion has been known at least since 1873, when Butlerov and 30 Gorianov reported that isobutene and propylene became oligom~ri7ed by a BF3 treatment at room temperature (Kennedy, J., Cationic polym~ri7~tion of olefins, J. Wiley & Sons, New York, 1975, p. 8).

Oligom~ri7~ion occurs in the presence of an active catalyst complex. Such a catalyst Wo 94/15895 PCT/FI93/00540 2152fi6~ 2 complex can be prepared through a reaction between BF3 and a cocatalyst, separate from the oligomerization reactor or in situ in the reactor. Water, short-chain alcohols, and or-ganic acids are commonly mentioned as the cocatalysts used. A 1-butanol cocatalyst has commonly been used together with BF3 when the object has been to produce fractions 5 suitable for use as lubricants or their additives. For the above uses, the monomer has commonly been some long-chain alpha-olefin or internal olefin, or their mixture. In particular, 1-decene has been used as the monomér.

The combination of BF3, 1-butanol and 1-decene has been used by, for example, Cupples 10 et al. (US 4 282 392), Shubkin (US 4 910 355), Dileo (EP 352 723), and Akatsu (EP
364 889). Other cocatalysts used with BF3 and decene include water (Bronstert, EP
271 034), alcohol alcoxylate (Theriot, EP 467 345), alcohol mixtures (Pratt, US 4 587 3-68), an alcohol ester mixture (Brennan, US 3 997 621), and a mixture of butanol and ethyl glycol or of butanol, ethyl glycol and methylethyl ketone (Morgansson and Vayda, 15 US 4 409 415, US 4 436 947, EP 77 113).

Watts et al. (US 4 413 156), Darden et al. (US 4 420 646), Hammond et al. (US
4 420 647, EP 136 377), and Larkin et al. (US 4 434 308) used as the initial m~tçn~lc C8-Cl8 internal olefins or mixtures of C8-C,8 internal olefins and alpha-olefins. The oligomeri-20 zation of this fraction with a BF3-1-butanol catalyst yielded as products fractions suitable for use for the preparation of additives for lubricants.

Nipe et al. (US 4 225 739) also used a BF3-1-butanol catalyst for copolymerization in which the short-chain olefin was propylene and the long-chain olefin was a mixture of C~s~
25 C,8 olefins.

Larkin et al. (US 4 395 578, US 4 417 082, and US 4 434 309) used for copolymerization 1-butene or propylene as the short-chain olefin and from one to three C6-Cl8 alkenes of different lengths as the long-chain olefin. The catalyst system consisted of BF3 and 1-30 butanol and possibly a transition-metal cation.

Pasky (US 4 451 684) used for co-oligom~n7~tion propylene oligomers having an average carbon chain length of 12-i8 and C5-C6 olefins, the catalyst complex comprising BF3 and _ Wo 94/15895 215 2 6 6 9 PCT/Fl93/00540 butanol.

Nelson and Zuech (US 4 484 014) used a two-step method in which the first step was a coordination catalyzed reaction for the oligomerization of ethylene with TEA (triethyl 5 aluminum) into C6-C,6 olefins. The reaction occurs at a higher temperature than does normal oligomPri7~tion of ethylene. For this reason the C6-CI6 fraction contained branched olefins 10 - 55 %, whereas under normal conditions nearly 100 % straight-chain alpha-olefins would have been produced with TEA. In the second step, the produced mixture of ethylene oligomers was further oligomerized in a batch reaction into a lubricant fraction 10 by using a BF3-propanol catalyst. In this, the catalyst complex formed in situ through a reaction between BF3 and propanol.

Schick and Gemmil (US 4 182 922) used propylene or a mixture of ethylene and propyle-ne as the monomer feed in the first step. This mixture was oligomerized with a catalyst 15 of VOC13 and ethyl aluminum chloride. The produced oligomer mixture was further co-oligomerized with a longer-chain olefin or a mixture of propylene and a longer-chain olefin by using a BF3-propanol complex formed in situ. The longer-chain olefin used was butene, hexene or decene. The longer-chain olefin or the mixture of propylene and a longer-chain olefin was fed into the second step in a 'h-batch manner. The viscosity index 20 of the reaction products was dependent on the longer-chain olefin used. When butene was used, the viscosity index of the end product was 113 and, when decene was used, it was 133.

Hsia Chen and Tabak (US 4 568 786) used as the feed in the first step a mixture of 25 propylene and butene, which was oligomerized with an HZSM-5-zeolite catalyst. From the formed product there was separated a C9-Cl8 fraction, which was oligomerized in the second step with a zeolite or BF3 catalyst. In a BF3-catalyzed batch reaction, butanol was used as a cocatalyst, and the complex was formed separate from the oligomerization reactor.

Herkelcberg et al. (US 4 319 064, US 4 386 229) used as the 1st step a disproportionation reaction of l-octene and/or l-decene to produce a mixture of C8-Cl8 internal olefins. This mixture or a part of it was oligomerized in the 2nd step with a BF3-propanol or BF3-WO 94115895 215 2, 6 6 9 4 PCTtFI93/00540 phosphoric acid catalyst complex formed in situ.

The catalysts used for the oligomerization of the Raffinate I stream flow, which contains n-butenes and inert butanes in addition to the principal component i-butene, depend in part 5 on the desired product distribution. Torck et al. (GB 1 312 950) used as a di- and trim~ri7~tion catalyst, for example, a BF3-HF complex in a tetramethylene sulfonic solution. Chen et al. (US 4 849 572) used water and/or methanol as a cocatalyst, in which case the product, poly-i-butene, had M" = 520-1500 g/mol. Samson (EP 145 235) used a BF3-ethanol complex for the oligomeri7~tion of R~ffin~te I.
For the oligomerization of the ~ffin~te II stream, which contains 1- and 2-butenes and inert butanes as the principal components, Halaska et al. (EP 337 737) used BF3 or alkyl aluminum chlorides having a general formula of R2AlCl or RAlCl2, where R is a Cl-C8 alkyl. As cocatalysts they used HF, HCl, or compounds which contained a reactive15 chlorine or fluorine atom bound to a tertiary, benzylic or allylic carbon atom. These catalyst systems are the same as the catalysts used in the patent of Loveless et al. (US
4 041 098) for the oligom~ri7~tion of C3-CI4 olefins, preferably C8-C10 olefins.
Pure 1-butene was oligomerized by Audisio and Priola (Makromolekulare Chemie, vol.
20 191, 1990, pp. 725-730) by using a separately prepared catalyst complex which was made up of BF3 and water or phosphoric acid.

Carboxylic acid cocatalysts are little known in the oligomerization of short-chain olefins.
Sheng and Arnold (US 4 263 465) used as a cocatalyst a carboxylic acid having at25 maximum five carbon atoms. Their process was a two-step process. The first step comprised the oligomerization of l-butene into a fraction having a number-average carbon chain length of 8-18, preferably 10-16 carbon atoms. In the second step, the product fraction of the first step is co-oligomerized with C8-CI8 alpha-olefin. In each step there was used in the batch reaction a catalyst complex which had been prepal~d by a reaction 30 between BF3 and a cocatalyst, separate from the oligomerization reactor.

Carboxylic acids, among them those containing five carbon atoms, have also been used for the oligomerization of longer-chain olefins. For example, in patent GB 1 378 449, n-_ Wo 94/15895 2155 2 6 6 9 PCT/F193/00540 and i-valeric acid, methylbutanoic acid, or mixtures of these were used for catalyzing the oligomeri7~tion of C6-Cl2 olefins, preferably 1-decene, together with BF3. In this patent the catalyst complex was formed separate from the oligomerization reactor. Furthermore, two different flows were fed into the reactor, in a 'h-batch manner. These flows consisted 5 of a BF3-cocatalyst complex and a monomer saturated with BF3.

The present invention relates to a method for the oligomeri_ation of olefins and olefin mixtures in a one-step process by using a boron trifluoride cocatalyst complex. In this invention, the oligomeri_ation of olefins or olefin mixtures is carried out in a one-step 10 process by using as the catalyst a boron trifluoride cocatalyst complex in which the cocatalyst is water, a C2-ClO monoalcohol, or a C2-C8 monocarboxylic acid, preferably pentanol or valeric acid. The invention is characterized by the characteristics presented below in the patent claims.

lS By the process according to the present invention it is possible to oligomerize olefins and olefin mixtures. The olefin l~lixlu~e is preferably the so-called R~ffin~te II stream, in which the principal coll~l)onents are 1- and 2-butenes and butanes, or a mixture of a longer-chain, C6-C20 olefin and R~ffin~te II. A method for the oligomeri7~tion of such clures is not previously known in the liteldt~re. In addition, it is also possible by the 20 method to oligomerize long-chain olefins alone, as shown in the examples.

When olefin mixtures are oligom~-ri7pd by the method according to the invention, the products formed are co-oligomers and not, for example",-ix~u,~s of oligomers of butene and oligomers of longer-chain olefin (homo-oligomers). In the reaction the olefins may 25 randomly link with a hydrocarbon chain, and this can be demonstrated with the appended mass spectrometric analyses (the experiments corresponding to the chromatograms presented are Examples 63-66). The analyses were performed by direct inlet mass spectrometry by using as the ~ualdt~ls a VG Trio-2-quadrupole mass spectrometer (VG
Masslab, Manchester, U.K.). Analysis conditions: mass range 200-1000 g/mol, scanning 30 time 3 s, electron energy 70 eV, ionization current 200 ~A, ion source temperature 200 C. The temperature program used for the sample evaporation was: S0 C (2 min) + S0 C/min 400 C.

WO 94/lS895 215 2 6 6 9 PCT~93/00540 Olefin oligomers are terhnic~lly important intermedi~tes which can be used for the preparation of highly various end products.

Oligomers plc~aled according to the present invention contain in the polymer chain an S olefinic double bond having increased reactivity. The p~opelLies of the oligomers include resistance to oxidation under the effect of heat, a low pour point, low volatility, and a good ~l~lpeldture-viscosity depçndence. The above pro~el Lies are important, especially if the oligomers are used for the production of lubricants and their additives. On the other hand, the method according to the invention can also be used for producing oligomers 10 having a low viscosity index. These oligomers and their derivatives are used in the main for applications other than lubricants and their additives.

Owing to the reactive double bond the oligomers can be used as intermediates in the production of various çhemi~l colllpoul-ds. In the pl~aldtion of chemic~lc, oligomers are lS used for the pr~dtion of, for example, alkyl ben7Pnes, alkyl phenols, and alkyl succinic acid anhydride. From alkyl be-n7~nes and alkyl phenols, surface active agents are l,lepa~ed by sulfonation. In additives of lubricants, oligomers can be used, for example, in the pl~aldtion of sulfonates, phen~t~s, thiophosphonates, and ash-free dispersing agents, alkenyl succinimides In these colll~ounds the molecular mass of the hydrocarbon fraction 20 is approx. 350-1200 g/mol, in alkenyl succinimide as high as 2500 g/mol. Other uses include the use as a lubricant in two-stroke spark-ignition engines, as the processing oil in the rolling and drawing of metallurgic m~t~ri~ls, in the leather and rubber industries, and in making various surfaces hydrophobic. By the hydrogenation of oligomers it is possible to obtain high-quality transformer oils, electrical insulation and cable oils, and 25 non-toxic cosmetic oils and white oils.

To illustrate the present invention, the oligomeri_ation of olefins and olefin mixtures by a one-step method is further described in a number of examples, which do not, however, limit the scope of the invention in any way.
Unless otherwise mentioned, the oligomeri7~tion reactions of olefins and olefin mixtures were performed in a steel reactor the volume of which was 300 ml and which was cooled internally by means of a cooling coil and was heated, when necesc~ry, externally in an WO 94/15895 PCT/~93/00540 electric mantle. The reactor was equipped with a stirrer. The lel.lpeldture of the reaction i~lule was monitored by means of a thermocouple. The telllpelature of the reaction Illi~lure was m~int~ined at the set value with a precision of + 1 C. The reagents used and their amounts are m~ntioned in the examples.

The reactor was first charged with a solvent, if necesc~ry~ and with the cocatalyst mentioned in the examples. Liquid monomer was fed into the reactor in the desired amount. After the adding of the monomer, the reactor was pres~u~ized by means of BF3 gas, whereupon the catalyst complex formed in situ and the reaction started immediately.
10 The monomer or the monomer mixture and the catalyst were fed into the liquid phase of the reactor. The reactor pressure was maintained constant by means of BF3 gas. The pressure was s-lfficient to keep the monomers in the liquid phase. The reaction parameters used were as follows: pres~ure 0-10 bar, expressed as o~ es~lre; reaction temperature 10-70 C; and reaction time 1-120 minutes or 1-8 hours. The reaction was halted by 15 adding into the reactor an excess of either an NaOH solution or water. The product fraction was washed with an NaOH solution and was neutralized with water after the wash. The product distribution was analyzed by the GC method.

The examples illustrate the various possibilities of the process for producing oligomer 20 fractions with different monomers and catalyst systems. The reference examples are Fx~mplps 1-15. The present invention is illustrated by Examples 16-66. It should be bome in mind that by the process being disclosed it is possible to produce highly different product distributions, so the examples only suggest the possibilities offered by the process.

25 Reference examples, in which the monomer is l-butene (Examples 1-15).

Examples 1 and 2.

The cocatalyst used was n-valeric acid at 5.1 mmol per one mole of l-butene. The reactor 30 ~1~;s5ule was 4.0 bar and te-..peldlulc; 20 C. In Example 1 the reaction time was 9 min-utes and in Example 2 it was 49 ~lh~u~es. After the said reaction times, the reactions were halted by means of an NaOH solution. The hydrocarbon phases were analyzed, the results being as follows.

2~5~ G(g9 PCT/F193/00540 Selectivities (%) Example C4~onversion C" C,z C,6 C20 C24 C2g C3,+
84,6 % - 7,7 23,236,224,0 8,9 2 92,7 % 0,4 1,2 4,112,8 18,9 14,8 47,0 s The number-average molecular masses of the product distributions according to the examples were 268 g/mol and 383 g/mol. From the product of Example 2, the C,6 hydrocarbons and fractions lighter than this were separated by vacuum ~ till~tion. The viscosity index determined on this unhydrogenated product was 81, the kinem~tic viscosity being KV100 = 4.3 cSt.

Example 3.

The cocatalyst used was n-valeric acid at 13.4 mmol per one mole of 1-butene. The reactor pl~s~ule was 2.5 bar and le---pelaLure 20 C. In Example 3 the reaction time was 49 minutes. After the said reaction time, the reaction was halted by means of an NaOH
solution. The hydrocarbon phase was analyzed, the result being as follows:

Selectivities (%) Example C4 conversion C8 C,2 C,6 C20 C24 C28 C32+

3 81.8% 0.6 43.3 40.7 10.5 3.9 1.0 The number-average molecular mass of the product distribution according to the example was 202 g/mol.
Example 4.

The cocatalyst used was n-valeric acid at 13.0 mmol per one mole of 1-butene. The reactor pres~u-~; was 4.0 bar and te---~ tu~e 20 C. The reaction time was 6 hours. After the said reaction time, the reaction was halted by means of an NaOH solution. The hydrocarbon phase was analyzed, the result being as follows:

-- WO 94/15895 PCT/~193/00540 Selectivities (%) E~ample C~ cc.. ~ .o,. C8 C,~ C,h C20 C24 C 8 C32~

4 approx. 99% 0.9 4.2 9.0 8.0 7.5 8.4 58.4 .

S The number-average molecular mass of the product distribution according to Example 4 was 386 g/mol.

Examples 5 and 6.

10 The cocatalyst used was n-valeric acid at 4.9 mmol per one mole of 1-butene. The reactor pres~ul~ was 10 bar and le,l")eldl~lre 40 C. In Example S the reaction time was 4 min-utes and in Example 6 it was 121 minutes. After the said reaction times the reactions were halted by means of an NaOH solution. The hydrocarbon phases were analyzed, the results being as follows:

Selecti~rities (%) E~ample C4- ~ tiV.I C8 cl2 cl6 C20 C24 C~8 C32+
60.6 9~ - 6. 1 21 .6 36.2 23.9 12.2 6 appro~c. 99% - 5.7 7.3 9.3 13.3 13.1 51.4 The number-average molecular masses of the product distributions according to the examples were 275 g/mol and 371 g/mol. The viscosity index determined on this unhydrogenated product was 82, the kin~m~tic viscosity being KV100 = 7.0 cSt.

25 Fx~mples 7 and 8.

The cocatalyst used was n-valeric acid at 5.0 mmol per one mole of 1-butene. The reactor plcs~ure was 10 bar and te"")el~ture 70 C. In Example 7 the reaction time was 9 min-utes and in Example 8 it was 121 minutes. After the said reaction times the reactions were 30 halted by means of an NaOH solution. The hydrocarbon phases were analyzed, the results being as follows:

215~669 10 Selectivities (%) E~ample C4 conversion C8 C,2 C~6 C20 C24 C28 C32+
7 63.2% 0.927.1 40.3 24.4 7.3 - -8 approx. 98% - 8.8 19.7 19.0 29.5 13.4 9.6 s The number-average molecular masses of the product distributions according to the eY~mples were 219 g/mol and 286 g/mol. From the product of Example 8, the Cl6 fraction and fractions lighter than this were separated by vacuum dic~ tion. The viscosity index determined on this unhydrogenated product was 58, the kinem~tic viscosity being 10 KV100 = 2.8 cSt.

Examples 9-15.

l-Butene can also be oligomçri7~d with organic acid catalysts other than n-valeric acid, 15 for example, with alcohols and water, as shown by Fy~mr]es 9-15. The reactor p-ess.-.e used was 4.0 bar and le,llp~dll~re 20 C, the reaction time being 36 minutes. The cocatalysts used were acetic acid (Example 9), n-octanoic acid (10), ethanol (11), 1-pentanol (12), l-octanol (13), and water (14). The reference example (15) is a reaction ed with n-valeric acid under the same conditions. Cocatalyst was used at a ratio20 of 14.5-15.9 mmol of cocatalyst per one mole of l-butene. The results are shown in the following table, where nk,~ stands for mmol of cocatalyst per one mole of butene.

E~am- C~ ,l nkk Selectivities (%) ple C8-C16C20-C28c32+ C4 conversion 9 C2 acid 15.157.0 43.0 - 77.0%
10C8 acid14.817.459.423.2 83.9%
11ethanol14.5 5.475.419.2 80.4~
12pentanol15.910.069.9 20.1 74.8%
13octanol14.522.761.116.2 79.2%
14 water15.012.7 87.3 - 61.2%
15n-valeric15.018.359.7 22.0 86.7%
acid WO 94/15895 PCT/F~93/00540 The invention is ill-~trat~d in the following eY~mples 1~62, in which the monomers shown in the table below were used.

Example Monomer 16-29 Raffinate II, i.e. a mixture of butene and butane 30-50 ~ffin~te II + alpha-olefin 51-62 long-chain alpha-olefin Example 16.

The cocatalyst used was n-valeric acid at 32 mmol per one mole of the butene mixture.
The reactor pressure was 4.0 bar and temperature 20 C. In Example 16 the reaction time 15 was 75 minutes. After the said reaction time the reaction was halted by means of an NaOH solution. The hydrocarbon phase was analyzed, the result being as follows:

Example C4 conversion Yields (%) %

C8-C~6 C20-C28 C32+ Mn (g/mol) 16 100 48,5 48,7 2,8 240 Examples 17 and 18.

The cocat~lyst used was n-valeric acid at 52 mmol per one mole of the butene mixture.
In Example 17 the reactor p~sa~lle was 5.7 bar and te,-~peldtule 30 C. In Example 18 25 the reactor pressure was 4.5 bar and te"~peldture 10 C. The reaction time was 120 minutes in both examples. After the said reaction times the reactions were halted by means of an NaOH solution. The hydrocarbon phases were analyzed, the results being as followS:

WO 94/1~895 2 ~5 2 6 6 9 12 1~Cr/~lg3/00540 Example C4 conversion Yields (%) C8-C,6 C20-C3 C32+ Mn (g/mol) 17 99,0 33,5 55,6 9,9 258 18 99,5 26,8 55,5 17,2 272 5 From the products of Examples 17 and 18, the-C,6f~c~O,, and fractions lighter than this were separated by vacuum di~till~tion. Kinem~tic viscosities (KV100, cSt) were measured and viscosity indices (VI,-)were determined for these unhydrogenated products. For the product of Example 17, KV100 = 3.3 cSt and VI = 21. For the product of Example 18, KV100 = 4.0 cSt and VI = 12.
Examples 19 and 20.

The cocatalyst used was n-valeric acid at 10 mmol per one mole of the butene mixture.
In Example 19 the reactor pres:,ulc was 4.7 bar and te"l~,e.dtule 10 C. In Example 20 15 the reactor ple~ re was 5.1 bar and ~Illp~ldluJe 30 C. The reaction time in both examples was 30 minutes. After the said reaction times the reactions were halted by means of an NaOH solution. The hydrocall,on phases were analyzed, the results being as follows:

20 Examples C4 conversion Yields (%) %

CR_CI6 C~-C3 c32+ Ml, (g/mol) 19 n. 100 58,3 39,2 2,5 232 20 n. 100 79,3 20,0 0,7 199 Examples 21 and 22.

In Example 21, the cocatalyst used was n-valeric acid at 51 mmol per one mole of the butene mixture. The reactor pressure was 3.1 bar and telllpeld~ul~ 10 C. In Example 22, the cocatalyst used was n-valeric acid at 53.5 mmol per one mole of the butene mixture.
The reactor pressure was 3.8 bar and lelllpe,dlure 30 C. The reaction time in both ex-30 amples was 30 minutes. After the said reaction times the reactions were halted by meansof an NaOH solution. The hydrocarbon phases were analyzed, the results being as -_ WO 94/15895 PCT/F193/00540 follows:

Example C4 conversion Yields (%) %

C8-CI6 C20-C28 c32+ Mn (~/mol) 21 n. 100 67,7 32,3 0 210 - 5 2I n. 98 93,5 4,5 0 156 Examples 23-29.
The monomer was Raffinate II, i.e. a mixture of butene and butane. Raffinate II can also be oligomerized with organic acid catalysts other than n-valeric acid, for example, with 10 alcohols and water, as shown by Examples 23-29. The reactor pressure was 6-7 bar and temperature 20 C, the reaction time being 120 minutes. The cocatalysts used were acetic acid (Example 23), n-octanoic acid (Example 24), ethanol (Example 25), l-pentanol (Example 26), 1-octanol (Example 27), and water (Example 28). The reference example (29) was a reaction pelrolllled under the same conditions by using n-valeric acid.
lS Cocatalyst was used at a ratio of 2.8-3.7 mmol of cocatalyst per one mole of the butane mixture.

Example Cocatalyst nkk Selectivities (%) C8-C,6C2o~C28C32+ M" (g/mol) 23 C2 acid 3,71 38,654,4 7,0 238 24 C8 acid 3,02 28,248,9 22,9 278 ethano1 2,72 59,634,5 5,9 185 26 pentanol 2,87 38,539,2 22,3 237 27 octanol 2,82 27,039,7 33,3 282 28 water 3,51 65,425,5 9,1 174 29 n-valericacid 3,2628,8 52,8 18,4 269 Examples 30-35.

30 The table shows the alpha-olefin used as the comonomer, the cocatalyst used, and the product distributions as yields. Into the reactor there were fed 100 grams of Raffinate II
and 20-21 grams of the alpha-olefin mentioned in the examples. The reaction conditions used were: temperature 40 C; pressure 7-8 bar; and reaction time 120 minutes. The WO 94/1589~ 6 6 9 PCTIF193/00540 cocatalyst used was n-valeric acid (C5 acid) or l-pentanol (C5 alcohol); the amounts are mentioned in the examples (kk, g). The product properties were determined on products from which the Cl6 fraction and fractions lighter than this had been removed by vacuum ~isti]l~tion. Kinem~tic viscosity (KV100, cSt), viscosity index (VI,-) and pour point (PP, 5 C) were determined on these unhydrogenated products.

Example Alpha- Cocatalyst kk Selectivities (%) olefin (~) Cg-C,6 C O- C32+ KVI0 Vl PP
C~8 C8 C5 acid 2,930,8 55,7 13,5 3,2 47 -60 31 Cl. -"- 2,927,8 61,9 10,3 3,1 70 ~0 32 C,6 ~ 2,930,1 43,9 26,0 3,4 80 -30 33 CB C5_ 2,128,7 48,1 23,2 3,6 54 -54 alcohol 34 C,2 ~"~ 2,226,1 54,0 19,9 3,9 76 C,6 -~- 2,224,6 39,4 36,0 4,3 91 Example 36.

60 g of dodecene and 66 g of Raffinate II were fed into the reactor. The cocatalyst used 20 was 2.2 grams of l-pentanol. The reaction conditions were: reaction time 120 minutes;
temperature 30 C; and pressure 6 bar. After the said reaction time, the reaction was halted by means of an NaOH solution. The hydrocarbon phase was analyzed, the result being as follows:

25 C8-Cl6 13-4 %; C20-C2R 43.6 %; C32+ 5.3 %; KV100 119; VI 119; and PP -51 C.

Kinematic viscosity (KV100, cSt), viscosity index (VI,-) and pour point (PP, C) were determined on the unhydrogenated product from which the Cl6 fraction and fractions lighter than this had been removed by vacuum ~1istill~tion.
Examples 37-50.

Wo 94tl5895 215 2 6 6 9 PCT/~3100540 The examples show the monomer feed col-lposi~ions, the reaction times, and the product distributions. ~ffin~te II and alpha-olefin were fed into the reactor in the amounts mentioned in the examples. The reaction conditions were: ~e1"~ldture 30 C and pressure 4-8 bar, i.e. sufficient to m~int~in ~ffin~te II in liquid state in each experiment. The S cocatalyst used was n-valeric acid in an amount of 2.85 grams. After the said reaction times, the reactions were halted by means of an NaOH solution. The hydrocarbon phases were analyzed, the results are shown in the tables.

The product properties mentioned in the examples, i.e. kinematic viscosity (KVl00, cSt), 10 viscosity index (VI,-) and pour point (PP, C), were determined on an unhydrogenated product from which the Cl6 fraction and fractions lighter than this had been removed by vacuum dictill~tion. In Examples 37-41 the alpha-olefin was l~ctene (S9 g) and the feed was Raffinate II (68 g).

Example Alpha-Cocatalyst Reaction Selectivities (%) olefin time (min) C8- C20-C32+ KV10 Vl PP
C,6 C28 37 l .octene n-valeric 10 2,1 acid 54,7 43,2 38 -"- -~- 30 11,4 33,4 55,2 39 -~ - 60 20,2 24,4 55,5 -"- -"- 120 30,9 17,5 51,5 41 -~- -"- 240 40,4 3,9 83 -57 15,4 44,2 Examples 42-46.

25 In the examples the feed materials were l-dodecene (60 g) and ~ffin~te II (42 g).

Example Alpha- Cocatalyst Reacti- Selectivities (%) olefin on time (min) C8- C20- C32+ KVlO Vl PP
C,6 C28 42 l-dode-n-valeric 10 56,9 13,0 ceneacid 29,9 43 -~- -"- 30 59,1 25,9 14,8 44 -~- -"- 60 55,1 35,3 9,6 -"- -~- 120 47,1 44,8 8,0 46 -"- -~- 240 38,3 53,9 5,0 119-54 7,8 Examples 47-50.
The alpha-olefin was l-hPl~dectone (71 g) and the feed was ~ffin~te II (38 g).

Example Alpha-Cocatalyst Reaction Selectivities (%) olefin time (min) C8- C20- C32+ KV10 Vl PP
C,6 C28 15 47 l-hexa-n-valeric lO 35,5 25,5 deceneacid 38,9 48 -~ - 70 29,8 55,6 14,6 49 - - -- - 120 25,7 65,4 8,8 -~ - 240 20,6 72,6 5,9 138-15 6,7 20 Examples 5 1 -62.

Into the reactor was fed 100 g of alpha-olefin. The reaction conditions used were a temperature of 30 C and a pressure of 3.0-3.2 bar, and the cocatalyst was n-valeric acid in an amount of 2.9-3.0 g. After the said reaction times the reactions were halted by WO 94/1~895 PCT/~193/00540 means of an NaOH solution. The hydrocarbon phases were analyzed, the results being as follows (fractions: mono = monomer; di-tetra = di-, tri-, and tetramers; penta+ =
pentamers and fractions higher than this). In Examples 51-54 the alpha-olefin is 1-octene, in Examples SS-58 it is i-dodecene, and in Examples 59-62 it is 1-hex~ece-~e.
s The results are shown in the following table.

Example reaction timeYields (%) (min) mono di-tetra penta +
51 10 9,8 86,2 3,9 52 60 2,1 87,0 10,9 53 120 1,2 81,2 17,6 54 240 1,3 63,2 35,6 æ,s 72,9 4,6 56 60 8,6 80,1 11,4 57 120 4,5 77,6 17,8 58 240 2,6 64,4 33,1 59 10 25,1 71,3 3,4 6,0 81,7 12,4 61 120 4,2 76,0 19,9 62 240 4,2 65,9 29,9 Examples 63-66.

In Example 63 the reaction conditions were: reaction temperature 30 C; pressure 3 bar 25 expressed as BF3 overpressure; and reaction time 4 hours. ~ffin~te II was fed in as the monomer in an amount of 100 g and n-valeric acid as the cocatalyst in an amount of 2.86 g. The obtained product was analyzed mass spectrometrically.

The product in Example 64 was a product prepared according to Example 58, which was 30 analyzed mass spectrometrically.

The product in Example 65 was a product prepared according to Example 46, which was Wo 94/15895 215 2 6 6 9 PCT/FI93/00540 analyzed mass spectrometrically.

The product in Example 66 had been plepa,ed by mixing in mass proportions 50:50 the products of Example 63 and Example 58. This mixture was analyzed mass spectrometri-5 cally.
;
The appended mass spectrometric analysës depict the analyses of four different experi-ments graphically, showing the absolute intensities of corresponding peaks of whole molecules (the molecular mass of which corresponds to the molecular mass of the alkene 10 having a certain carbon number) with different molecular mass values. The peaks co.le~l.ollding to fragmented products have been omitted from these alkene graphs; the be-havior of these peaks with different values of molecular mass, however, corresponds to the peaks of whole molecules. The following observations can be made from the graphs:

15 - In the alkene graph of butene oligomers (Fig. 1: R~ffin~te II oligomers), the domin~ting alkene peaks are observable at carbon numbers 16, 20, 24, 28, 32, etc., i.e. at carbon numbers col,c~onding multiples, oligomers, of the carbon number of butene. The absolute inten.~itie~ of the alkene peaks corresponding to buteneoligomers decrease as the carbon number increases steadily.
- Respectively, the alkene peaks dominating in the alkene graph of dodecene oligo-mers (Fig. 2: Dodecene oligomers) are at carbon numbers 24, 36, 48, etc., i.e. at carbon numbers corresponding to multiples, oligomers, of the carbon number of dodecene. The absolute intensities of the alkene peaks colle~onding to dodecene oligomers decrease as the carbon number increases steadily.

- The alkene peaks dominating in the alkene graph of products produced in the co-oligomerization between butenes and dodecene (Fig. 3: C12-Raff Il co-oligomers) are at carbon numbers 16, 20, 24, 28, 36, etc. The absolute intencities of the alkene peaks decrease as the carbon number increases steadily.

- The alkene peaks dominating in the alkene graph of a blend of butene oligomersand dodecene oligomers (Fig. 4: C12-Raff I oligomer blend) are at carbon numbers WO 94/15895 2 ~L S ~ 6 6 9 PCT/FI93/00540 16, 24, 36 and 48. The peak at carbon number 16 is due to butene oligomers, but at carbon numbers 24, 36 and 48 the peaks are mainly due to dodecene oligomers.
These graphs show clearly that olefin mixtures oligomerized by the method accor-ding to the invention do not produce mixtures of homo-oligomers but produce co-oligomers during the reaction when olefins rnay link randomly to the carbon chain.

Claims

AMENDED CLAIMS
[received by the International Bureau on 30 May 1994 (30.05.94) original claims 1-9 replaced by amended claims 1-5 (1 page)]

1. A method for the oligomerization of olefin mixtures comprising so called raffinate ll stream containing 1-butene and 2-butene together with one or more C6-C20-alpha-olefin characterized in that the olefin mixture is contacted with a complex formed by BF3 and a cocatalyst, which complex is prepared either in advance from BF3 and the cocatalyst or by feeding BF3 gas into the reaction chamber which contains cocatalyst and olefin or an olefin mixture

2. A method according to Claim 1, characterized in that the cocatalyst used is a C?-C8 monocarboxylic acid, preferably acetic acid, n-valeric acid, or n-octanoic acid

3. A method according to Claim l or 2, characterized in that the cocatalyst used is water or a C2-C10 monoalcohol, preferably pentanol

4. An oligomer prepared by a method according to Claims 1-3 from one or more olefin monomers, characterized in that its viscosity index is higher than that of an oligomer obtained from Raffinate II alone, and that its structure is of the co-oligomer type.

5. The use of an oligomer according to Claim 4 as a solvent, in fuels or lubricants. as an initial material for the preparation of chemical compounds which can be used. for ex-ample, as additives in lubricants and fuels, as surface-active agents, and as auxiliary agents in processing.