DE102008040365A1 - Separating ionic liquid, useful as catalyst to prepare homo-/co-polymers, from non-polar liquid mixtures having non-polar solvents, ionic liquids and other ingredients, comprises adsorbing ionic liquid in inorganic oxide carrier materials - Google Patents

Abstract

Method for separating ionic liquid from non-polar liquid mixtures comprising non-polar solvents as main components, ionic liquids and optionally other ingredients, where the weight ratio of ionic liquids to the non-polar solvent is less than 1:1000, comprises adsorbing the ionic liquid in an inorganic oxide carrier materials. An independent claim is included for a method for the preparation of homo- or co-polymer with a molecular weight of 10000-10000000 from a monomer with one or two polymerizable olefinic unsaturated double bond that comprises 3 or 4 carbon atoms and a desired comonomer with one or more polymerizable olefinic unsaturated double bond that comprises 3 or 30 carbon atoms and same or different monomers comprising polymerization or copolymerization of these olefinic monomers and/or olefinic monomer containing monomer mixture in liquid phase in the presence of non-polar solvent and at least one ionic liquid as polymerization catalyst, where after the polymerization, the ionic liquid is separated by adsorption on the inorganic oxide carrier material.

Description

The The present invention relates to a process for the separation of ionic liquids from nonpolar mixtures that are made nonpolar solvents as main component, ionic Liquids and optionally other ingredients consist, wherein the weight ratio of the ionischen liquids to the nonpolar solvents is less than 1: 1000.

Furthermore, the present invention relates to a process for the preparation of homo- or copolymers having a weight-average molecular weight M _w of 10,000 to 10,000,000 of monomers having one or two polymerizable olefinically unsaturated double bonds having 3 or 4 carbon atoms, by polymerization or copolymerization of these olefinic monomers or a monomer mixture containing these olefinic monomers in the liquid phase in the presence of ionic liquids as a polymerization catalyst using the separation step according to the invention for the ionic liquids.

Ionian Liquids are characterized by being complete are made up of ions. Ionic liquids exist thus from salts or salt mixtures, usually below + 100 ° C, preferably below + 50 ° C, melt. Most ionic Liquids are therefore very polar and form miscibility gaps with nonpolar liquids, for example with hydrocarbons. In addition, they have compared to conventional organic Liquids a high density, not too high viscosity and a mean interfacial tension, so they normally easily by phase separation of conventional organic Liquids can be separated.

Lie However, the ionic liquids in very low concentration in a non-polar liquid mixture, which is mainly consists of non-polar solvents, as it is due to the high catalytic activity of ionic liquids often in their use as polymerization catalysts The case is a phase separation due to the extreme phase ratios difficult. To make matters worse, that the nonpolar medium is viscous and therefore the phase separation only done very slowly.

In In a first aspect, it was the object of the present invention an efficient method for the separation of ionic liquids in low concentrations of nonpolar liquid mixtures provide.

These Task was solved by a method for separation of ionic liquids from nonpolar liquid Mixtures consisting of nonpolar solvents as the main component, ionic liquids and optionally other ingredients consist, wherein the weight ratio of the ionischen liquids to non-polar solvents is less than 1: 1000, which is characterized in that the ionic liquids adsorbed on inorganic oxidic support materials.

From the DE 103 13 207 A1 (1) it is known that one can liberate ionic liquids by adsorption or ion exchange of adhering impurities. In this case, the ionic liquid is brought into contact with absorbents such as adsorbent resins, activated carbon, zeolites, aluminum oxides, molecular sieves or silica gels, for example by passing the ionic liquid through a column containing such a powdered absorbent; the impurities are bound to the absorbent and the ionic liquid leaves the column in purified form. However, in the prior art it is not known that in such an adsorption process the ionic liquid is bound and retained.

Furthermore, ionic liquids are described as catalyst systems for the polymerization of olefins such as polyisobutenes. So be in the WO 00/32658 (2) discloses various structures of ionic liquids for the preparation of high molecular weight polyisobutenes, namely imidazolium salts such as 1-ethyl-3-methylimidazolium aluminum tetrachloride, bridged imidazolium salts, pyridinium salts and pyrazolium salts.

In a second aspect, it was the object of the present invention to provide an efficient process for the preparation of higher molecular weight homo- or copolymers of olefinic monomers having 3 or 4 carbon atoms, especially higher molecular weight isobutene homo- or copolymers, using low concentrations of ionic Liquids as polymerization catalysts represents a technologically well-controlled and economically favorable access to such polymer and at the same time allows, after polymerization, the ionic liquids as simple and complete as to separate. In addition, the water content in the resulting homo- or copolymer solutions should be as low as possible.

This object has been achieved by a process for preparing homopolymers or copolymers having a weight-average molecular weight M _w of 10,000 to 10,000,000 from monomers having one or two polymerizable olefinically unsaturated double bonds which have 3 or 4 carbon atoms, and if desired comonomers with one or more a plurality of polymerizable olefinically unsaturated double bonds which have 3 to 30 carbon atoms and are different from the monomers used, by polymerization or copolymerization of these olefinic monomers or a monomeric mixture containing these olefinic monomers in the liquid phase in the presence of nonpolar solvents and at least one ionic liquid as Polymerisationskatalysa tor , which is characterized in that, after polymerization, the ionic liquids separated by adsorption to inorganic oxidic support materials.

The inorganic oxidic substrates - im hereinafter also called adsorbents - include all solid inorganic structures that combine with oxygen one or more metals, semi-metals and / or non-metals contain. It is preferable to use aluminas, zirconium oxides, Titanium oxides, calcium oxides, silica gels, sintered glass, silicates, Aluminosilicates, zeolites or mixtures thereof. Such adsorbents may also be in the form of molecular sieves. Preferably one works with alumina, zeolites and combinations thereof. The alumina used can in particular with a base, z. As an alkali or alkaline earth metal hydroxide or an alkali metal or alkaline earth metal cyanide.

The Adsorbents can be acidic, neutral or have a basic character. Particularly suitable adsorbents are also those on their surface next to acidic or weakly acidic areas also basic or weakly basic Have areas; For example, last ones are able, too to effectively bind acid impurities.

In In a preferred embodiment, the adsorbent comprises a zeolite with average pore sizes of at least 5 Å, in particular from 5 to 15 Å. The middle Pore size is due to the crystal structure of the zeolite set and can z. B. determined from X-ray structure data become. Preferably, the zeolites used are substantially acid-free.

preferred Zeolites are among zeolite A, zeolite L, zeolite X and zeolite Y selected. Sodium zeolite A or sodium zeolite A, in which the sodium ions wholly or partly by magnesium and / or Calcium ions are replaced, is particularly preferred. Another particularly preferred zeolite is zeolite 10 A (commercially for example available from Zeochem under the name Z10-03), which already has a high absorptive performance at comparatively low temperatures shows.

In Another preferred embodiment comprises Adsorbent an alumina. Aluminum oxides are used as adsorbents for gases, liquids and solids in particular in chromatographic methods and methods known. One can acid for the process according to the invention, Use neutral or basic aluminas, in particular suitable for this basic aluminum oxides. Acid aluminas usually have a pH of 3 to 6, typically about 4, on. Neutral aluminum oxides usually have a pH of 6 to 8, typically around 7. Basic aluminas are mostly a pH of 8 to 11, typically about 9.5.

The aluminum oxides mentioned generally have pore volumes of 0.5 to 1.5 ml / g, typically of about 0.9 ml / g, usually inner surfaces of 70 to 250 m ² / g, typically of about 150 m ² / g, and usually particle sizes in the range of 30 to 300 microns, typically from 60 to 150 microns.

More specific preferred adsorbent is a 13X molecular sieve, a molecular sieve 4, a molecular sieve 10 or high surface area gamma-aluminas (z. B. Selexsorb ^® from. Almatis).

The Adorption is expediently before his Use activated by usually under reduced Heated to a temperature of at least 150 ° C. or by usually at atmospheric pressure and at a Temperature of at least 150 ° C dry gaseous Nitrogen or a similar inert gas or gas mixture passes.

The contacting of the non-polar liquid mixture from which the ionic liquids abge to be separated, with the adsorbent can be done by any conceivable discontinuous or continuous process. Usually, the non-polar liquid mixture is passed through the solid absorbent, the absorbent being fixed substantially in position in the apparatus or equipment (absorber bed operation). Preferably, the adsorbent is in a fixed bed of charge disposed in an adsorption column through which the liquid stream is passed. The adsorption column is preferably arranged vertically and is flowed through by the liquid flow in the direction of gravity or preferably against the force of gravity. It is also possible to use a plurality of adsorption columns connected in series.

In a preferred embodiment of the present invention the adsorbent is in the form of an adsorber bed which Aluminas, zirconium oxides, titanium oxides, calcium oxides, silica gels, sintered glass, silicates, aluminosilicates, zeolites or mixtures contains from this.

When non-polar solvents, which are the main component of the nonpolar liquid mixtures that make up the ionic liquids are to be separated, represent, preferably hydrocarbons, in particular those having 4 to 8 carbon atoms, for example, aliphatic Hydrocarbons such as butane, pentane, hexane, heptane, octane and isooctane, cycloaliphatic hydrocarbons such as cyclopentane and cyclohexane, or aromatic hydrocarbons such as benzene, toluene and xylenes. Also corresponding technical mixtures of such hydrocarbons, which are commercially available as solvents and diluents available may be underlying. Besides may also be slightly polar halogenated hydrocarbons, in particular aliphatic chlorohydrocarbons such as dichloromethane or chloroform or chlorofluorocarbons ("freons", "frigens") such as difluorodichloromethane, Difluor chloromethane, 1,1,2-trifluoro-1,2,2-trichloroethane or 1,1,2,2-tetrafluoro-1,2-dichloroethane occur.

The Weight ratio of ionic liquids to the non-polar liquid mixtures is preferably in the range of 1: 1500 to 1: 100,000, especially in the range of 1: 2000 to 1: 20,000.

The Separation of the ionic liquids by the inventive Procedure is usually almost complete or almost completely; at least the inventive works Experience with a degree of depletion to a fifth or less, in particular to one tenth or less, of the original one Amount of ionic liquid.

In principle, a recovery of the bound to the adsorbent ionic liquids is possible. For this purpose, the adsorbent is usually with a suitable inert polar liquid such as in particular an alcohol, especially a linear or branched C ₁ - to C ₁₀ alkanol, for example methanol, ethanol, n-propanol, isopropanol, n-butanol, tert-butanol , 2-ethylhexanol or 2-propylheptanol, brought into contact, for example by washing, whereby the ionic liquid can pass into the inert polar liquid and can be isolated from there and reused. Furthermore, for the recovery of the ionic liquids from the adsorbent by the method described above are also suitable the above-mentioned low-polar halogenated hydrocarbons, especially dichloromethane. It is also possible to use mixtures of alcohols with one another, of halogenated hydrocarbons with one another and of alcohols with halogenated hydrocarbons.

• • Imidazoliumsalze tragen eine positive Ladung im Imidazolring, welche durch ein geeignetes Anion kompensiert wird, und können an den Imidazolring-Stickstoffatomen und/oder den Imidazolring-Kohlenstoffatomen durch Alkyl-, substituierte Alkyl-, Cycloalkyl-, substituierte Cycloalkyl-, Heteroalkyl-, Heterocycloalkyl-, substituierte Heterocycloalkyl-, Aryl-, substituierte Aryl-, Heteroaryl-, substituierte Hetero-aryl-, Alkoxy-, Aryloxy-, Acyl-, Silyl-, Boryl-, Phosphino-, Amino-, Thio- und/oder Seleno-Gruppen substituiert sein, wobei als derartige Substituenten C_l- bis C₄-Alkylgruppen wie Methyl, Ethyl, Propyl oder Butyl bevorzugt werden und wobei vorzugsweise zumindest die beiden Imidazolring-Stickstoffatome sol che C₁- bis C₄-Alkylgruppen tragen; typische Vertreter hierfür sind 1-Ethyl-3-methylimidazolium-salze;
• • Verbrückte Imidazoliumsalze bestehen aus zwei Imidazoliumringen und einer gegebenenfalls substituierten Kohlenwasserstoffbrücke zwischen entsprechenden Imidazolring-Stickstoffatomen, die eine positive Ladung im jedem Imidazolring tragen, welche durch geeignete Anionen kompensiert wird, und können an den Imidazolring-Stickstoffatomen und/oder den Imidazolring-Kohlenstoffatomen jeweils durch Alkyl-, substituierte Alkyl-, Cycloalkyl-, substituierte Cycloalkyl-, Heteroalkyl-, Heterocycloalkyl-, substituierte Heterocycloalkyl-, Aryl-, substituierte Aryl-, Hetero-aryl-, substituierte Heteroaryl-, Alkoxy-, Aryloxy-, Acyl-, Silyl-, Boryl-, Phosphino-, Amino-, Thio- und/oder Seleno-Gruppen substituiert sein, wobei als derartige Substituenten C₁- bis C₄-Alkylgruppen wie Methyl, Ethyl, Propyl oder Butyl bevorzugt werden und wobei vorzugsweise zumindest jeweils die unverbrückten Imidazolring-Stickstoffatome solche C₁- bis C₄-Alkylgruppen tragen; typische Vertreter hierfür sind 1,4-Bis-(3-Methylimidazolium)butan-Salze;
• • Pyridinumsalze tragen eine positive Ladung im Pyridinring, welche durch ein geeignetes Anion kompensiert wird, und können am Pyridinring-Stickstoffatom und/oder den Pyridinring-Kohlenstoffatomen durch Alkyl-, substituierte Alkyl-, Cycloalkyl-, substituierte Cycloalkyl-, Heteroalkyl-, Heterocycloalkyl-, substituierte Heterocycloalkyl-, Aryl-, substituierte Aryl-, Heteroaryl-, substituierte Heteroaryl-, Alkoxy-, Aryloxy-, Acyl-, Silyl-, Boryl-, Phosphino-, Amino-, Thio- und/oder Seleno-Gruppen substituiert sein, wobei als derartige Substituenten C₁- bis C₄-Alkylgruppen wie Methyl, Ethyl, Propyl oder Butyl bevorzugt werden und wobei vorzugsweise zumindest das Pyridinring-Stickstoffatom eine solche C₁- bis C₄-Alkylgruppe trägt; typische Vertreter hierfür sind 1-Ethyl-3-methylpyridiniumsalze;
• • Pyrazoliumsalze tragen eine positive Ladung im Pyrazolring, welche durch ein geeignetes Anion kompensiert wird, und können an den Pyrazolring-Stickstoffatomen und/oder den Pyrazolring-Kohlenstoffatomen durch Alkyl-, substituierte Alkyl-, Cycloalkyl-, substituierte Cycloalkyl-, Heteroalkyl-, Heterocycloalkyl-, substituierte Heterocycloalkyl-, Aryl-, substituierte Aryl-, Heteroaryl-, substituierte Heteroaryl-, Alkoxy-, Aryloxy-, Acyl-, Silyl-, Boryl-, Phosphino-, Amino-, Thio- und/oder Seleno-Gruppen substituiert sein, wobei als derartige Substituenten C₁- bis C₄-Alkylgruppen wie Methyl, Ethyl, Propyl oder Butyl bevorzugt werden und wobei vorzugsweise zumindest die beiden Pyrazolring-Stickstoffatome solche C₁- bis C₄-Alkylgruppen tragen; typische Vertreter hierfür sind 1,2,4-Trimethylpyrazoliumsalze und 1,2,4-Triethylpyrazoliumsalze;
• • Ammoniumsalze tragen eine positive Ladung, welche durch ein geeignetes Anion kompensiert wird, und können am Ammonium-Stickstoffatom durch Alkyl-, substituierte Alkyl-, Cycloalkyl-, substituierte Cycloalkyl-, Heteroalkyl-, Heterocyclo alkyl-, substituierte Heterocycloalkyl-, Aryl-, substituierte Aryl-, Heteroaryl-, substituierte Heteroaryl-, Alkoxy-, Aryloxy-, Acyl-, Silyl-, Boryl-, Phosphino-, Amino-, Thio- und/oder Seleno-Gruppen substituiert sein, wobei als derartige Substituenten C₁- bis C₂₀-Alkylgruppen, insbesondere C₁- bis C₄-Alkylgruppen wie Methyl, Ethyl, Propyl oder Butyl, bevorzugt werden und wobei vorzugsweise das Ammonium-Stickstoff-atom drei oder vier derartiger C₁- bis C₂₀-Alkylgruppen trägt; typische Vertreter hierfür sind Tetrabutylammoniumsalze und Trimethylamin-Hydrochlorid.

The process of the invention is in principle applicable to the separation of any ionic liquid. Preferably, however, it can be used for the separation of ionic liquids which are selected from imidazolium salts, bridged imidazolium salts, pyridinium salts, pyrazolium salts and ammonium salts. Such ionic liquids are described, for example, in (2) and can be characterized as follows:

• Imidazolium salts carry a positive charge in the imidazole ring which is compensated by a suitable anion, and can be attached to the imidazole ring nitrogen atoms and / or the imidazole ring carbon atoms by alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heteroalkyl, heterocycloalkyl , substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, alkoxy, aryloxy, acyl, silyl, boryl, phosphino, amino, thio and / or seleno Be substituted groups, wherein as such substituents C _l - to C ₄ alkyl groups such as methyl, ethyl, propyl or butyl are preferred and wherein preferably at least the two imidazole ring nitrogens sol che C ₁ - carry to C ₄ alkyl groups; typical representatives are 1-ethyl-3-methylimidazolium salts;
• Bridged imidazolium salts consist of two imidazolium rings and an optionally substituted hydrocarbon bridge between corresponding imidazole ring nitrogen atoms which carry a positive charge in each imidazole ring which is compensated for by suitable anions and may each pass through the imidazole ring nitrogen atoms and / or the imidazole ring carbon atoms Alkyl, sub substituted alkyl, cycloalkyl, substituted cycloalkyl, heteroalkyl, heterocycloalkyl, substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, alkoxy, aryloxy, acyl, silyl, boryl -, phosphino, amino, thio and / or seleno groups may be substituted, whereby as such substituent C ₁ - to -C ₄ -alkyl such as methyl, ethyl, propyl or butyl are preferred, and wherein at least in each case preferably the unbridged Imidazolring- Nitrogen atoms carry such C ₁ to C ₄ alkyl groups; typical representatives thereof are 1,4-bis (3-methylimidazolium) butane salts;
• Pyridinium salts carry a positive charge in the pyridine ring which is compensated by a suitable anion and may be substituted on the pyridine ring nitrogen and / or the pyridine ring carbon atoms by alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heteroalkyl, heterocycloalkyl , substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, alkoxy, aryloxy, acyl, silyl, boryl, phosphino, amino, thio and / or seleno groups wherein as such substituents C ₁ - to C ₄ alkyl groups such as methyl, ethyl, propyl or butyl are preferred and wherein preferably at least the pyridine ring nitrogen carries such a C ₁ - to C ₄ alkyl group; typical representatives thereof are 1-ethyl-3-methylpyridinium salts;
• Pyrazolium salts carry a positive charge in the pyrazole ring, which is compensated by a suitable anion, and can be attached to the pyrazole ring nitrogen atoms and / or the pyrazole ring carbon atoms by alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heteroalkyl, heterocycloalkyl , substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, alkoxy, aryloxy, acyl, silyl, boryl, phosphino, amino, thio and / or seleno groups substituted being preferred as such substituents C ₁ - to C ₄ alkyl groups such as methyl, ethyl, propyl or butyl and wherein preferably at least the two pyrazole ring nitrogen atoms carry such C ₁ - to C ₄ alkyl groups; typical representatives thereof are 1,2,4-trimethylpyrazolium salts and 1,2,4-triethylpyrazolium salts;
• Ammonium salts carry a positive charge which is compensated by a suitable anion and can be substituted on the ammonium nitrogen atom by alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heteroalkyl, heterocycloalkyl, substituted heterocycloalkyl, aryl, be substituted substituted aryl, heteroaryl, substituted heteroaryl, alkoxy, aryloxy, acyl, silyl, boryl, phosphino, amino, thio and / or seleno groups, wherein as such substituents C ₁ - to C ₂₀ -alkyl groups, in particular C ₁ - to C ₄ -alkyl groups such as methyl, ethyl, propyl or butyl, are preferred and wherein preferably the ammonium-nitrogen atom carries three or four such C ₁ - to C ₂₀ -alkyl groups; typical representatives are tetrabutylammonium salts and trimethylamine hydrochloride.

Besides But they can also be based on ionic liquids of phosphines, arsines, stibines, ethers, thioethers or selenoethers subjected to the dispersing process according to the invention become.

Examples of suitable anions for compensating the positive charges in said ionic liquids are F ^- , Cl ^- , Br ^- , I ^- , BF ₄ ^- , BCl ₄ ^- , BBr ₄ ^- , Bl ₄ ^- , PF ₆ ^- , AsF ₆ ^-, SbF ₆ ^-, FeF ₄ ^-, FeCl ₄ ^-, FeBr ₄ ^-, NO ₂ ^-, NO ₃ ^-, SO ₄ ^2-, an unsubstituted or substituted carborane, an unsubstituted or substituted Metallocarboran, a phosphate, a phosphite, a Polyoxymetallat, an unsubstituted or substituted carboxylate as especially acetate or propionate, a triflate, a borate with one or more organic residues or an aluminate of the formula [AlY _4-z Z _z] ^- or the formula [AlZ ₄ · m AlZ _3] ^- in which Y denotes hydrogen, an organic radical, a silyl radical, a boryl radical, a phosphino radical, an amino radical, a thio radical or a seleno radical, Z denotes a halogen atom, z represents the integer 0, 1, 2, 3 or 4 and m for a number from 0 to 5, esp special 0 to 3, stands.

In a preferred embodiment, said anion denotes an aluminate of the formula [AlZ ₄ .m AlZ ₃ ] ^- in which Z is a halogen atom and m is a number from 0 to 1.5, in particular 0 to 1.2. Typical such anions are, for example, the tetrachloroaluminate anion [AlCl ₄ ] ^- = [AlCl ₄ .m AlCl ₃ ] ^- where m = 0 and the heptachlorodialuminate anion [Al ₂ Cl ₇ ] ^- = [AlCl ₄ .m AlCl ₃ ] ^- with m = 1.0.

Often used ionic liquids are, for example, 1,2,4-trimethylpyrazolium or 1,2,4-triethylpyrazolium tetrachloroaluminate, 1,2,4-trimethylpyrazolium or 1,2,4-triethylpyrazolium heptachlorodialuminate and 1-ethyl-3-methylimidazolium tetrachloroaluminate or 1-ethyl-3-methylimidazolium heptachlorodialuminate.

When in the process according to the invention for the preparation of homo- or copolymers usable monomers with one or two polymerizable olefinically unsaturated Double bonds, which have 3 or 4 carbon atoms come Propene, 1-butene, 2-butene, isobutene and 1,3-butadiene into consideration.

In a preferred embodiment, the polymerization process according to the invention is used for the preparation of isobutene homopolymers or copolymers, in particular having a weight-average molecular weight M _w of 10,000 to 10,000,000.

Under Isobutene homopolymers are understood within the scope of the present invention those polymers which, based on the polymer, are at least 98 mol%, preferably at least 99 mol% are made up of isobutene. Accordingly, isobutene copolymers are understood to mean those polymers which which contain more than 2 mol% of monomers polymerized by Isobutene are different.

The inventive polymerization process is suitable in an excellent way for the production of higher molecular weight Homo- or copolymers of olefinic monomers, in particular of higher molecular weight isobutene homo- or copolymers. preferred Comonomers for the isobutene or the isobutene-containing monomer mixture are here styrene, styrene derivatives and styrene and styrene derivative-containing Monomer mixtures and alkadienes such as butadiene and mixtures thereof. In particular, one puts in the inventive Polymerization process isobutene or isobutene-styrene mixtures as monomers.

For the use of isobutene or an isobutene-containing monomer mixture as the monomer to be polymerized isobutene source is both isobutene itself and also isobutene-containing C ₄ hydrocarbon streams, for example C ₄ raffinates, C ₄ cuts from the isobutane dehydrogenation, C ₄ cuts from steam crackers and FCC crackers (fluid catalytic cracking), provided that they are largely exempt from 1,3-butadiene contained therein. Suitable C ₄ hydrocarbon streams generally contain less than 500 ppm, preferably less than 200 ppm, butadiene. The presence of 1-butene and of cis- and trans-2-butene is largely uncritical in the preparation of isobutene homopolymers - with controlled reaction. Typically, the isobutene concentration in the _C4 hydrocarbon streams is in the range of 40 to 60 wt .-%. The isobutene-containing monomer mixture may contain small amounts of contaminants such as water, carboxylic acids or mineral acids, without resulting in critical yield or selectivity losses. It is expedient to avoid an accumulation of these impurities by removing such pollutants from the isobutene-containing monomer mixture, for example by adsorption on solid adsorbents such as activated carbon, molecular sieves or ion exchangers.

It can monomer mixtures of isobutene or the Isobutene-containing hydrocarbon mixture with olefinically unsaturated Monomers which are copolymerizable with isobutene reacted become. If monomer mixtures of isobutene with suitable comonomers is to be copolymerized, contains the monomer mixture preferably at least 5% by weight, more preferably at least 10 Wt .-% and in particular at least 20 wt .-% isobutene, and preferably at most 95 wt .-%, particularly preferably at most 90 wt .-% and in particular at most 80% by weight of comonomers.

Suitable copolymerizable monomers for the olefinic monomers or for the isobutene are in particular vinylaromatics such as styrene, C ₂ -C ₄ -alkylstyrenes such as 2-, 3- and 4-ethylstyrene and 4-tert-butylstyrene, the olefins mentioned as monomers with 3 or 4 carbon atoms, if they are different from the monomers used, alkadienes such as butadiene, and isoolefins having 6 to 10 C atoms, such as 2-methylpentene-1, 2-methylhexene-1,2-ethylpentene-1,2-ethylhexene 1 and 2-propylheps-1. Also suitable as comonomers are olefins which have a silyl group, such as 1-triethoxysilylethene, 1- (trimethoxysilyl) -propene, 1- (trimethoxysilyl) -2-methylpropene-2, 1- [tri (methoxyethoxy) silyl] ethene, 1 - [tri (methoxyethoxy) silyl] propene, and 1- [tri (methoxyethoxy) silyl] -2-methylpropene-2, as well as vinyl ethers such as tert-butyl vinyl ether.

When copolymerizable monomers are also suitable, for example 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene or 1-dodecene. Farther can also cyclic olefins such as cyclohexene or else Terpenes, which are open-chain, monodose formal dimers of isoprene or polycyclic systems with 10 carbon atoms, for example ocimene, myrcene, terpinene, terpinolene, phellandrene, Limes or pinenes used as copolymerizable monomers become. These copolymerizable monomers can also contain functional groups such as ether functions or carboxy groups, Examples of such monomers are vinyl ethers such as methyl vinyl ether, Ethyl vinyl ether or tert-butyl vinyl ether, vinyl esters such as vinyl formate or vinyl acetate and (meth) acrylic acid ester such as methyl acrylate or ethyl methacrylate.

If copolymers are to be prepared by the process according to the invention, the process can be designed such that preferably random polymers or preferably block copolymers are formed. For the preparation of block copolymers, it is possible for example to feed the various monomers one after the other to the polymerization reaction, the addition of the second comonomer in particular only then follows when the first comonomer is already at least partially polymerized. In this way, both diblock, triblock and higher block copolymers are accessible, which have a block of one or the other comonomer as a terminal block, depending on the order of monomer addition. In some cases, however, block copolymers also form when all comonomers are simultaneously fed to the polymerization reaction, but one of them polymerizes significantly faster than the one or the other. This is the case in particular when isobutene and a vinylaromatic compound, in particular styrene, are copolymerized in the process according to the invention. In this case, block copolymers preferably form with a terminal polyisobutene block. This is because the vinyl aromatic compound, especially styrene, polymerizes significantly faster than isobutene.

The Polymerization can be both continuous and batch respectively. Continuous processes can be analogously to known methods of the prior art for discontinuous Polymerization of isobutene in the presence of Lewis acid catalysts be carried out in the liquid phase.

The inventive method is usually at a polymerization temperature of -80 to + 100 ° C. carried out. It is in principle both for one Carrying out at low temperatures, eg. B. at -70 to 0 ° C, as well as at higher temperatures, d. H. at least 0 ° C, z. B. at 0 to 100 ° C, suitable. The polymerization is for economic reasons at least 0 ° C, z. B. at 0 to 100 ° C, in particular at 10 to 60 ° C, aimed at the energy and material consumption, which is required for cooling, if possible to keep low. It can, however, with equally good technical result even at lower temperatures, eg. B. at -50 to <0 ° C, preferably at -40 to -10 ° C, performed become.

He follows the polymerization at or above the boiling point of polymerizing monomer or mixture of monomers, it is preferred in pressure vessels, for example in autoclaves or in pressure reactors.

The Polymerization is in the presence of inert non-polar solvents carried out in which as polymerization catalysts used ionic liquids usually solved or suspended. These are preferably as described above Hydrocarbons, in particular those having 4 to 8 carbon atoms, For example, aliphatic hydrocarbons such as butane, pentane, Hexane, heptane, octane and isooctane, cyclo-aliphatic hydrocarbons such as cyclopentane and cyclohexane, or aromatic hydrocarbons such as benzene, toluene and xylenes. In addition, halogenated hydrocarbons, in particular aliphatic chlorinated hydrocarbons such as dichloromethane or chloroform or chlorofluorocarbons ("Freone", "Frigene") such as difluorodichloromethane, difluorochloromethane, 1,1,2-trifluoro-1,2,2-trichloroethane or 1,1,2,2-tetrafluoro-1,2-dichloroethane can be used. It can in the polymerization with other inert solvents to be present. The inert solvents used should be suitable during the polymerization reaction usually occurring increase in viscosity the reaction solution to reduce so much that the discharge ensures the resulting heat of reaction can be. They are such solvents or solvent mixtures suitable, compared to the starting materials used and reagents are inert. Preferably, solvents before using impurities like water, carboxylic acids or mineral acids, for example by adsorption to solid adsorbents such as activated carbon, molecular sieves or ion exchangers.

Preferably the polymerization is largely aprotic, in particular carried out under anhydrous reaction conditions. Under aprotic or anhydrous reaction conditions one that the water content (or the content of protic impurities) in the reaction mixture less than 50 ppm and especially less than 5 ppm. As a rule, therefore, one becomes the starting materials prior to their use by physical and / or chemical Dry measures. In particular, it has proven the inert hydrocarbons used as solvent after usual pre-cleaning and predrying with an organometallic Compound, for example an organolithium, organomagnesium or organoaluminum compound, in an amount that sufficient to remove the traces of water from the solvent remove. The solvent thus treated is then preferably condensed directly into the reaction vessel. In similar You can also with the monomers to be polymerized, in particular with isobutene or with the isobutene-containing mixtures, proceed. Also the drying with other usual desiccants such as molecular sieves or predried oxides such as alumina, silica, Calcium oxide or barium oxide is suitable. Vinyl aromatic compounds and other feedstocks for which drying with metals such as sodium or potassium or a treatment with metal alkyls not be considered, with suitable drying agents, for example with calcium chloride, phosphorus pentoxide or molecular sieve, freed from water (traces).

The Polymerization of said olefinic monomers or monomer mixtures or the feedstock containing these monomers or monomer mixtures, in particular the isobutene or the isobutene-containing feedstock, usually occurs spontaneously when contacting the polymerization catalyst with the monomer or the monomer mixture in the desired Reaction temperature. Here one can proceed in such a way that one that the Monomer or the monomer mixture, if appropriate in the solvent submits, brings to reaction temperature and then adding the polymerization catalyst. You can also do that if appropriate, the polymerization catalyst in the solvent presents and then the monomer or the monomer mixture admits. The beginning of polymerization is then the time, to which all reactants in the reaction vessel are. The polymerization catalyst may be partially or completely dissolve in the reaction medium or be present as a suspension.

The as polymerization catalysts effective ionic liquids are dissolved in the polymerization medium, for example, suspended or as a fluid bed. Preferably sets as polymerization catalysts for the preparation of homo- or copolymers, in particular the isobutene homo- or copolymers, ionic liquids, which are selected are from imidazolium salts, bridged imidazolium salts, Pyridinium salts, pyrazolium salts and ammonium salts; this ionic Liquids are described above. Typical ionic Liquids for use as polymerization catalysts for isobutene or isobutene-containing monomer mixtures for example, 1,2,4-trimethylpyrazolium or 1,2,4-triethylpyrazolium tetrachloroaluminate, 1,2,4-trimethylpyrazolium or 1,2,4-triethylpyrazolium hepta chlorodialuminate and 1-ethyl-3-methylimidazolium tetrachloroaluminate or 1-ethyl-3-methylimidazolium heptachlorodialuminate.

suitable Reactor types for the inventive Polymerization processes are usually stirred tank reactors, Loop reactors, tubular reactors, fluidized bed reactors, fluidized bed reactors, Stirred tank reactors with and without solvent and Fluidized bed reactors.

to The preparation of copolymers can be carried out in such a way that the monomers, optionally in solvent, and then submitted adding the polymerization catalyst. The setting of the reaction temperature can be done before or after the addition of the polymerization catalyst. It is also possible to proceed in such a way that one initially only one the monomers, optionally in solvent, presents, then adding the polymerization catalyst and only after a certain time, for example if at least 60%, at least 80% or at least 90% of the monomer are reacted, the one or more monomers added. Alternatively, the polymerization catalyst, optionally in solvent, submit, then add the monomers simultaneously or sequentially and then the set the desired reaction temperature. As the beginning of polymerization then the time at which the polymerization catalyst and at least one of the monomers in the reaction vessel are.

Next The discontinuous procedure described here can be make the polymerization as a continuous process. This leads to the starting materials, d. H. that or the to be polymerized monomers, optionally the solvent and optionally the polymerization catalyst of the polymerization reaction continuously and continuously withdraws reaction product, so that in the reactor more or less stationary polymerization conditions to adjust. The one or more monomers to be polymerized as such, diluted with a solvent or as a monomer-containing hydrocarbon stream, are supplied.

To Successful polymerization is within the meaning of the present invention no longer necessary, a suitable chain stopper the Feed or to be dispersed in this polymerization medium. This deactivation was usually by addition a protic compound, in particular by the addition of water or methanol or by adding an aqueous base, e.g. As an aqueous solution of an alkali or alkaline earth metal hydroxide such as sodium hydroxide, potassium hydroxide, magnesium hydroxide or calcium hydroxide, an alkali or alkaline earth carbonate such as sodium, potassium, magnesium or calcium carbonate, or an alkali or alkaline earth hydrogen carbonate such as sodium, potassium, magnesium or calcium bicarbonate. It is sufficient according to the invention, after Polymerization, d. H. when the desired turnover is reached is the ionic liquid used as a polymerization catalyst as described above by adsorption to inorganic oxidic Separate support materials.

In the copolymerization of isobutene or isobutene-containing hydrocarbon cuts with at least one vinylaromatic compound, for example styrene, block copolymers are preferably formed even with simultaneous addition of the comonomers, the isobutene block generally representing the terminal block, ie the last formed block. Particularly preferably, such a monomer mixture contains 5 to 95 Wt .-%, particularly preferably 30 to 70 wt .-% styrene.

Preferably have the with the inventive method prepared isobutene homo- or copolymers, especially the isobutene homopolymers, a polydispersity (PDI = MW / Mn) of 1.0 to 3.0, before anything of at most 2.0, preferably from 1.0 to 2.0, more preferably from 1.0 to 1.8 and especially from 1.0 to 1.5 on.

The homopolymers or copolymers prepared by the process according to the invention preferably comprise monomers having one or two polymerizable olefinically unsaturated double bonds which have 3 or 4 carbon atoms, in particular the isobutene homo- or copolymers prepared by the process according to the invention, a weight-average molecular weight M _w of 25,000 up to 5,000,000, in particular from 75,000 to 4,000,000 and above all from 150,000 to 3,000,000.

The The following examples are intended to illustrate the present invention, without restricting it.

example 1

Separation of 1-ethyl-3-methylimidazolium heptachlorodialuminat from heptane

It were 10 ml / h of a 3 wt .-% solution of 1-ethyl-3-methylimidazolium-heptachlorodialuminat in dichloromethane in 40 ml / min heptane continuously emulsified. The resulting dichloromethane-heptane emulsion had a content 1-Ethyl-3-methylimidazolium heptachlorodialuminat of 313 ppm by weight (corresponding 41 ppm by weight aluminum) ("zero sample").

Each 80 ml of this emulsion were replaced by a with each 30.0 g of a inorganic oxidic carrier material (absorbent) filled short column passed. The eluates were each with 25 ml of dilute hydrochloric acid and shaken vigorously. From the severed Subphase was that derived from the ionic liquid Aluminum content ("Al") and thus the content of remaining ionic Liquid ("IL") by a customary for this Measuring method determined. In this way, the Al or the IL content of the blank has been determined.

The following table shows the contents of the 80 ml samples for the adsorbents used: zero sample 41 ppm by weight Al 313 ppm by weight IL Molsieb-4 (4 Å) 1.9 ppm by weight Al 14.4 wt ppm IL Molsieb-10 (10 Å) 1.9 ppm by weight Al 14.4 wt ppm IL basic alumina <3 ppm by weight Al <22.8 wt ppm IL

Example 2

Separation of 1-ethyl-3-methylimidazolium acetate from heptane

It were 10 ml / h of a 3 wt .-% solution of 1-ethyl-3-methylimidazolium acetate in dichloromethane in 40 ml / min heptane continuously emulsified. The resulting dichloromethane-heptane emulsion had a content 1-Ethyl-3-methylimidazolium acetate of 2064 ppm by weight (corresponding to 170 ppm by weight of nitrogen) ("zero sample").

Each 80 ml of this emulsion were replaced by a with each 30.0 g of a inorganic oxidic carrier material (absorbent) filled short column passed. The eluates were each with 25 ml of dilute hydrochloric acid and shaken vigorously. From the severed Subphase was that derived from the ionic liquid Nitrogen content ("N") and thus the content of remaining ionic Liquid ("IL") by a customary for this Measuring method determined. In this way, the N- or the IL content of the blank has been determined.

The following table shows the contents of the 80 ml samples for the adsorbents used: zero sample 170 ppm by weight N 2064 ppm by weight IL Molsieb-4 (4 Å) 10 ppm by weight N 121 ppm by weight of IL Molsieb-10 (10 Å) 20 ppm by weight N 242 ppm by weight IL

Example 3

Polymerization of isobutene by means of Ethyl 3-methylimidazolium heptachlorodialuminate as a catalyst and working up with molecular sieve or with aqueous sodium hydroxide solution

In a 230 ml glass-walled, flow-through glass reactor at jacket temperature of -78 ° C. and internal temperature of -70 ° C., 28.6 g / min of heptane, 8.9 g / min of isobutene and 0.0017 g / min of ethyl-3 were continuously added. methylimidazolium-heptachlorodialuminat closed. 100 ml of the effluent product solution were passed through 30 ml of heated molecular sieve (4 Å or 10 Å) in a suction filter or extracted with 30 ml of a 10 wt .-% aqueous sodium hydroxide solution. After passing through the suction filter or after phase separation depending Weil the water content of the organic polymer solution was determined by Karl Fischer titration. Water content after adsorption over annealed Molsieb-4 (4 Å): 12/15 ppm Water content after adsorption over annealed Molsieb-10 (10 Å): 8/10 ppm Water content after extraction with 10% strength by weight NaOH: 44 ppm

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• DE 10313207 A1 [0007]
• WO 00/32658 [0008]

Claims (9)

A process for the separation of ionic liquids from non-polar liquid mixtures consisting of non-polar solvents as the main component, ionic liquids and optionally other ingredients, wherein the weight ratio of the ionic liquids to the nonpolar solvents is less than 1: 1000, characterized in that the ionic Liquids adsorbed to inorganic oxidic support materials. Process for the separation of ionic liquids of nonpolar liquid mixtures according to claim 1, characterized characterized in that as inorganic oxidic support materials Aluminas, zirconium oxides, titanium oxides, calcium oxides, silica gels, sintered glass, silicates, aluminosilicates, zeolites or mixtures used from this. Process for the separation of ionic liquids of nonpolar liquid mixtures according to claim 1 or 2, wherein the weight ratio of the ionic liquids to the nonpolar solvents is 1: 1500 to 1: 100,000. Process for the separation of ionic liquids from nonpolar liquid mixtures according to the claims 1 to 3, which as nonpolar solvent hydrocarbons containing 4 to 8 carbon atoms. Process for the separation of ionic liquids from nonpolar liquid mixtures according to the claims 1 to 3, characterized in that the absorption of the ionic Liquids by passing the nonpolar liquid Mixture over the inorganic present as a solid oxidic support material, this substantially is fixed in its position in the apparatus or installation (absorber bed procedure), performs. Use of inorganic oxidic support materials for adsorptive separation of ionic liquids from nonpolar liquid mixtures, which are made from nonpolar solvents as the main component, ionic liquids and optionally consist of other ingredients, wherein the weight ratio from ionic liquids to nonpolar solvents is less than 1: 1000. A process for the preparation of homo- or copolymers having a weight average molecular weight M _w from 10,000 to 10,000,000 from monomers having one or two polymerizable olefinically unsaturated double bonds, which have 3 or 4 carbon atoms, and, if desired, comonomers having one or more polymerizable olefinically unsaturated double bonds, which have 3 to 30 carbon atoms and are different from the monomers used, by polymerization or copolymerization of these olefinic monomers or a monomeric mixture containing these olefinic monomers in the liquid phase in the presence of nonpolar solvents and at least one ionic liquid as a polymerization catalyst, characterized in that Successful polymerization separates the ionic liquids by adsorption to inorganic oxidic support materials. Process for the preparation of homo- or copolymers according to claim 7, characterized in that as ionic liquids Imidazolium salts, bridged imidazolium salts, pyridinium salts, Pyrazolium salts or ammonium salts used. Process for the preparation of homopolymers or copolymers according to Claim 7 or 8, characterized in that it is used for the preparation of isobutene homo- or copolymers having a weight-average molecular weight M _w of 10,000 to 10,000,000.