Process for preparing high-reactivity isobutene homo- or copolymers

Abstract

The present invention relates to a novel process for preparing high-reactivity isobutene homo or copolymers of different molecular weight and with a high content of terminal vinylidene double bonds per polyisobutene chain end.

Description

[0001] Process for preparing high-reactivity isobutene homo- or copolymers

[0002] Description

[0003] The present invention relates to a novel process for preparing high-reactivity isobutene homo- or copolymers of different molecular weight and with a high content of terminal vinylidene double bonds per polyisobutene chain end.

[0004] Polyisobutenes can be categorised into low-, medium-, and high molecular weight polyisobutene to their molecular weight. Furthermore, depending on the molecular weight polyisobutene may be classified as highly reactive depending on the content of terminal vinylidene double bonds per polyisobutene chain end.

[0005] Depending on the molecular weight and on the content of terminal double bond the polyisobutene is referred to as

[0006] - High molecular polyisobutene with a number-average molecular weight Mnof more than

[0007] 100000 g / mol

[0008] - Medium molecular polyisobutene with a number-average molecular weight Mnof more than 10000 and up to 100000 g / mol

[0009] - Medium molecular polyisobutene is usually referred to as highly reactive with a content of terminal (alpha-) double bonds of 10 to 60 mol%, preferably 15 to 55 mol%, more preferably 20 to 50 mol%, even more preferably 25 to 50 mol%, and especially at least 25 to 45 mol%. The content of terminal (alpha-) double bonds may even be 30 to 80 mol%.

[0010] - Low molecular polyisobutene with a number-average molecular weight Mnof more than

[0011] 350 and up to 10000 g / mol

[0012] - Low molecular polyisobutene is usually referred to as highly reactive with a content of terminal (alpha-) double bonds of at least 50 mol%, preferably at least 60, more preferably at least 70, even more preferably at least 80, and especially at least 85 mol%. The content of such alpha-double bonds may be up to 100, up to 98, up to 97 or up to 95 mol%.

[0013] In contrast to so-called low-reactivity polymers, low molecular high-reactivity isobutene homo- or copolymers are understood to mean those polyisobutenes which comprise a high content of terminal ethylenic double bonds (a-double bonds) and other reactive double bonds, such as p- double bonds, susceptible to subsequent reactions, such as Alder-Ene-reaction with maleic acid anhydride, specifically in practice usually of at least 60, preferably at least 70 and very preferably at least 75 mol%, based on the individual chain ends of the polyisobutene macromolecules. In the context of the present application, vinylidene groups are understood to mean those terminal ethylenic double bonds whose position in the polyisobutene macromolecule is described by the general formula polymer i.e. the double bond is present in an a position in the polymer chain. "Polymer" represents the polyisobutene radical shortened by one isobutene unit. The vinylidene groups exhibit the highest reactivity in many types of reactions, for example in the thermal addition onto sterically demanding reactants such as maleic anhydride, whereas a double bond further toward the interior of the macromolecules in most cases exhibits lower reactivity, if any, in functionalization reactions. The uses of high-reactivity polyisobutenes include use as intermediates for preparing additives for lubricants and fuels, as described, for example, in DE-A 27 02 604.

[0014] It has additionally been known for some time that the Lewis acid aluminum trichloride can also be used as a polymerization catalyst for isobutene, for example from High Polymers, volume XXIV (part 2), p. 713-733 (editor: Edward C. Leonard), J. Wiley & Sons publishers, New York, 1971.

[0015] In the literature article "Novel initiating system based on AlCh etherate for quasiliving cationic polymerization of styrene" in Polymer Bulletin Vol. 52, p. 227-234 (2004), Sergei V. Kostjuk et al. describe a catalyst system composed of 2-phenyl-2-propanol and an aluminum trichloride / di- n-butyl ether complex for polymerization of styrene. Polymerization of isobutene with a complex of AlCh and dibutylether to highly reactive polyisobutene was described in Sergei V. Kostjuk et al., Macromolecules 2010, 43, 5503-5507.

[0016] Dmitriy I. Shiman, Irina V. Vasilenko, Sergei V. Kostjuk, Journal of Polymer Science, Part A: Polymer Chemistry 2014, 52, 2386-2393 disclose the preparation of polyisobutene polymers by polymerizing isobutene in the presence of an alkylaluminum halogenide an ether complex as a polymerization catalyst.

[0017] US 4379899 describes a process for manufacturing of high molecular polyisobutene using tertiary butyl halides as initiator and a catalyst of alkylaluminium halides with a further metal halide. Example 24 discloses a mixture of triisobutyl aluminium with SnCL as co-catalyst. Although large amounts of catalyst and co-catalyst were used the polymer yield and the conversion of isobutene are low. The polymerisation of high molecular polyisobutene only is disclosed, no information is given on the content of terminal double bonds of such polyisobutenes.

[0018] US 8937138 describes a process for the preparation of isobutene homopolymers with a weight average molecular weight of up to 1000000 g / mol using mixtures of Lewis Acids, inter alia AlCh and butyl tin chloride. Butyl tin chloride is used in amounts of not more than 2 mol% with regard to AlCh (Examples 17 and 28). No information is given on the content of terminal double bonds of such polyisobutenes.

[0019] US 4379899 describes the preparation of polyisobutene in the presence of a an alkyl aluminium halide, preferably ethyl aluminium dihalides and a metal halide selected from SnCL, SnBr4, TiBr4 and TiCk No electron donor is used as component of the catalyst system, furthermore, no information is given on the content of terminal double bonds of such polyisobutenes.

[0020] GB 1407417 describes the copolymerisation of isobutene and isoprene in the presence of Lewis Acids. Explicitly disclosed is the use of Sn(Et)4 and AIEtCh (Example 6), Sn(Et)4 and AlCh (Example 8), Sn(Et)4 and AIBrs (Example 10), and SnCh(Acetat)2 and AIBrs (Example 11). No electron donor is used as component of the catalyst system, furthermore, no information is given on the content of terminal double bonds of such polyisobutenes.

[0021] It was an object of the present invention to provide a process for preparing high-reactivity isobutene low- and medium molecular homo- or copolymers, in acceptable yields and high reaction rates. It was further an object of the present invention to develop a catalyst system which leads to high conversion and keeps the selectivity of the reactive double bonds, especially the cidouble bonds even at high conversion.

[0022] The object was achieved by a bulk- or solution polymerisation process for preparing high- reactivity isobutene homo- or copolymers with a number-average molecular weight Mn(determined by gel permeation chromatography) of preferably of 500 to 100 000, which comprises polymerizing isobutene or an isobutene-comprising monomer mixture in the presence of a donor complex of at least two Lewis Acids effective as a polymerization catalyst, wherein the first Lewis Acid is an aluminium halide of the formula

[0023] AI(ORa)p(Rb)qXr, wherein

[0024] Raand Rbindependently of another represent an organic residue of up to 20 carbon atoms, preferably Ci- to C2o-alkyl, C5- to Cs-cycloalkyl radical, Ge- to C2o-aryl radical or C7- to C20- arylalkyl radical,

[0025] X independently of another represents halide, p independently of another represents a rational number of at least 0 (zero) and less than 3, q independently of another represents a rational number of at least 0 (zero) and less than 3, and r independently of another represents a rational number of greater than 0 (zero) up to 3, with the proviso that the sum of (p + q + r) is always 3 and wherein the second Lewis Acid is selected from the group consisting of a tin dihalide and a tin tetrahalide, preferably selected from the group consisting of tin dichloride and tin tetrachloride, said complex comprising, as the donor, at least one organic compound (II) comprising at least one oxygen or nitrogen atom with at least one lone electron pair, preferably comprising at least one oxygen atom with at least one lone electron pair, very preferably selected from the group consisting of organic compounds with at least one ether function, organic compounds with at least one carboxylic ester function, organic compounds with at least one aldehyde function, organic compounds with at least one keto function, and organic compounds with at least one nitrogen containing heterocyclic ring. According to the present invention the metal halide is a mixture of at least two Lewis Acids, at least one aluminium halide of the formula

[0026] AI(ORa)p(Rb)qXras first Lewis Acid and at least one tin halide selected from the group consisting of a tin dihalide and a tin tetrahalide, preferably selected from the group consisting of tin dichloride and tin tetrachloride, more preferably tin tetrachloride as second Lewis Acid.

[0027] In the first Lewis Acid of the formula

[0028] AI(ORa)p(Rb)qXr, the variables are defined as follows:

[0029] Raand Rbindependently of another represent an organic residue of up to 20 carbon atoms, preferably Ci- to C2o-alkyl, Cs- to Cs-cycloalkyl radical, Ce- to C2o-aryl radical or Cy to C20- arylalkyl radical,

[0030] X independently of another represents halide, p independently of another represents a rational number of at least 0 (zero) and less than 3, q independently of another represents a rational number of at least 0 (zero) and less than 3, and r independently of another represents a rational number of greater than 0 (zero) up to 3, with the proviso that the sum of (p + q + r) is always 3.

[0031] The aluminium-containing first Lewis Acid is preferably selected from the group consisting of aluminum trihalide, alkylaluminum dihalide, dialkylaluminum monohalide, alkyloxyaluminum dihalide, di(alkyloxy)aluminum monohalide, alkyl alkoxy aluminium halides, and mixtures thereof.

[0032] In case of mixtures of compounds AI(ORa)p(Rb)qXrthe values of p, q, and r may represent rational numbers for the mixtures, for each individual compound the values of p, q, and r are integer.

[0033] Preferably p is from 0.5 to 1.5, very preferably from 0.7 to 1.3 and especially from 0.8 to 1.2.

[0034] Preferably q is not more than 2, very preferably not more than 1 , and r is always 3 - p - q.

[0035] In a potential embodiment q is 0 (zero). In this case very preferred hydrocarbyloxy aluminum compounds are AI(ORa)o.7- i.2Xi.8-2.3.

[0036] In a preferred embodiment p is 0 (zero) so that the first Lewis Acid is an alkyl aluminium halide or aluminium trihalide.

[0037] In a very preferred embodiment both p and q are 0 (zero) so that the first Lewis Acid is an aluminium trihalide.

[0038] A suitable aluminum trihalide is especially aluminum trifluoride, aluminum trichloride or aluminum tribromide, preferably aluminum trichloride.

[0039] A useful alkylaluminum halide is especially a mono(Ci- to C4-alkyl)aluminum dihalide or a di(Ci- to C4-alkyl)aluminum monohalide, for example methylaluminum dichloride, ethylaluminum dichloride, iso-butylaluminum dichloride, dimethylaluminum chloride or diethylaluminum chloride, diiso-butylaluminum chloride, preferably ethylaluminum dichloride, iso-butylaluminum dichloride, diethylaluminum chloride or diiso-butylaluminum chloride and very preferably ethylaluminum dichloride and iso-butylaluminum dichloride.

[0040] Preferably it is selected from the group consisting of aluminum trihalide, alkylaluminum dihalide, and alkylaluminum dihalide, more preferably it is selected from the group consisting of aluminum trihalide and alkylaluminum dihalide, and especially the first Lewis Acid is aluminum trihalide.

[0041] In the context of the present invention, the following definitions apply to generically defined radicals: A Ci- to Cs-alkyl radical is a linear or branched alkyl radical having 1 to 8 carbon atoms. Examples thereof are methyl, ethyl, n-propyl, isopropyl, n-butyl, 2-butyl, isobutyl, tert-butyl, pentyl, 1- methylbutyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethyl-propyl, 1 -ethylpropyl, n-hexyl, 1 ,1- dimethylpropyl, 1 ,2-dimethylpropyl, 1 -methylpentyl, 2-methylpentyl, 3-methylpentyl, 4- methylpentyl, 1 ,1 -di methyl butyl, 1 ,2-dimethylbutyl, 1 ,3-di methyl butyl, 2,2-dimethylbutyl, 2,3- dimethylbutyl, 3,3-dimethylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1 , 1 ,2-trimethylpropyl, 1 ,2,2- trimethylpropyl, 1 -ethyl-1 -methylpropyl, 1-ethyl-2-methylpropyl, n-heptyl, n-octyl and the constitutional isomers thereof, such as 2-ethylhexyl. Such Ci- to Cs-alkyl radicals may to a small extent also comprise heteroatoms such as oxygen, nitrogen or halogen atoms, for example chlorine, and / or aprotic functional groups, for example carboxyl ester groups, cyano groups or nitro groups. However, radicals purely consisting of carbon and hydrogen are preferred.

[0042] A Ci- to C4-alkyl radical is methyl, ethyl, n-propyl, isopropyl, n-butyl, 2-butyl, isobutyl or tertbutyl.

[0043] A Ci- to C2o-alkyl radical is a linear or branched alkyl radical having 1 to 20 carbon atoms. Examples thereof are the abovementioned Ci- to Cs-alkyl radicals, and additionally n-nonyl, isononyl, n-decyl, 2-propylheptyl, n-undecyl, n-dodecyl, n-tridecyl, isotridecyl, n-tetradecyl, n- hexadecyl, n-octadecyl and n-eicosyl. Such Ci- to C2o-alkyl radicals may to a small extent also comprise heteroatoms such as oxygen, nitrogen or halogen atoms, for example chlorine, and / or aprotic functional groups, for example carboxyl ester groups, cyano groups or nitro groups. However, radicals purely consisting of carbon and hydrogen are preferred.

[0044] A Cs- to Cs-cycloalkyl radical is a saturated cyclic radical which may comprise alkyl side chains. Examples thereof are cyclopentyl, 2- or 3-methylcyclopentyl, 2,3-, 2,4- or 2,5- dimethylcyclopentyl, cyclohexyl, 2-, 3- or 4-methylcyclohexyl, 2,3-, 2,4-, 2,5-, 2,6-, 3,4-, 3,5- or 3,6-dimethylcyclohexyl, cycloheptyl, 2-, 3- or 4-methylcycloheptyl, cyclooctyl, 2-, 3-, 4- or 5- methylcyclooctyl. Such C5- to Cs-cycloalkyl radicals may to a small extent also comprise heteroatoms such as oxygen, nitrogen or halogen atoms, for example chlorine, and / or aprotic functional groups, for example carboxyl ester groups, cyano groups or nitro groups. However, radicals purely consisting of carbon and hydrogen are preferred.

[0045] A Cs- to C2o-aryl radical or a Cs- to Ci2-aryl radical is preferably optionally substituted phenyl, optionally substituted naphthyl, optionally substituted anthracenyl or optionally substituted phe- nanthrenyl. Such aryl radicals may be a 1 to 5 aprotic substituents or aprotic functional groups, for example Ci- to Cs-alkyl, Ci- to Cs-haloalkyl such as Ci- to Cs-chloroalkyl or Ci- to Cs- fluoroalkyl, halogens such as chlorine or fluorine, nitro, cyano or phenyl. Examples of such aryl radicals are phenyl, naphthyl, biphenyl, anthracenyl, phenanthrenyl, tolyl, nitrophenyl, chlorophenyl, dichlorophenyl, pentafluorophenyl, pentachlorophenyl, (trifluoromethyl)phenyl, bis(tri- fluoromethyl)phenyl, (trichloro)methylphenyl and bis(trichloromethyl)phenyl. However, radicals purely consisting of carbon and hydrogen are preferred.

[0046] A C7- to C2o-arylalkyl radical or a C7- to Ci2-arylal kyl radical is preferably optionally substituted Ci- to C4-alkylphenyl such as benzyl, o-, m- or p-methylbenzyl, 1- or 2-phenylethyl, 1-, 2- or 3- phenylpropyl or 1-, 2-, 3- or 4-phenylbutyl, optionally substituted Ci- to C4-alkylnaphthyl such as naphthylmethyl, optionally substituted Ci- to C4-alkylanthracenyl such as anthracenylmethyl, or optionally substituted Ci- to C4-alkylphenanthrenyl such as phenanthrenylmethyl. Such arylalkyl radicals may bear 1 to 5 aprotic substituents or aprotic functional groups, especially on the aryl moiety, for example Ci- to Cs-alkyl, Ci- to Cs-haloalkyl such as Ci- to Cs-chloroalkyl or Ci- to Cs-fluoroalkyl, halogen such as chlorine or fluorine, nitro or phenyl. However, radicals purely consisting of carbon and hydrogen are preferred.

[0047] Halide is fluoride, chloride, bromide or iodide, preferably fluoride, chloride or bromide, very preferably chloride or bromide and especially chloride.

[0048] In a preferred embodiment the hydrocarbyloxy aluminum compounds are used as mixtures of at least two of the above-mentioned compounds.

[0049] Among the hydrocarbyloxy residues Ci- to C2o-alkyloxy and Cs- to C2o-aryloxy radicals are preferred, and Ci- to Cs-alkyloxy and Cs- to Ci2-aryloxy radicals are more preferred, with Ci- to C4- alkyloxy groups being most preferred. Alkyl groups are preferred over aryl groups.

[0050] Among the alkyl groups Ci- to Cs-alkyl groups are more preferred and Ci- to C4-alkyl groups most preferred. Among the halides X fluoride, chloride, and bromide are preferred, chloride and bromide more preferred and chloride is most preferred.

[0051] Preferred organic residues Raare methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, and phenyl, very preferred are iso-propyl, n-butyl, and tert-butyl.

[0052] Preferred organic residues Rbare methyl, ethyl, n-propyl, iso-propyl, n-butyl, and iso-butyl, very preferred are ethyl and iso-butyl.

[0053] The tin-containing second Lewis Acid is selected from the group consisting of tin dihalide and tin tetrahalide, preferably selected from the group consisting of tin dichloride and tin tetrachloride, and especially is tin tetrahalide.

[0054] Especially suitable tin dihalides are tin difluorides, tin dichlorides, or tin dibromides, preferably tin dichlorides.

[0055] Especially suitable tin tetrahalides are tin tetrafluorides, tin tetrachlorides, or tin tetrabromides, preferably tin tetrachlorides.

[0056] In a preferred embodiment the second Lewis Acid is tin tetra chloride.

[0057] The molar ratio of first Lewis Acid : second Lewis Acid is from 20 : 1 to 1 : 20, preferably from 10 : 1 to 1 to 10, more preferably from 1 : 5 to 5 : 1 , even more preferably from 3 : 1 to 1 : 3, and especially from 2 : 1 to 1 : 2.

[0058] The mixture of Lewis Acids is used in the reaction according to the present invention as a donor complex wherein the donor is at least one organic compound (II) comprising at least one oxygen or nitrogen atom with at least one lone electron pair.

[0059] In a preferred embodiment it is possible first to mix the at least two Lewis Acids, optionally in a solvent, and afterwards to add the donor compound in the desired amount.

[0060] In another less preferred embodiment it is possible first to prepare a donor complex of the alu- minium-containing Lewis Acid and / or the tin-containing Lewis Acid and mix the at least two Lewis Acids afterwards.

[0061] The molar ratio of such metal halide : donor compound of formula (II) is from 1 : 0 to 10, preferably from 1 : 0.1 to 10, more preferably from 1 : 0.2 to 5, even more preferably 1 : 0,3 to 3. The metal halides are calculated as the sum of the first and the second Lewis Acid (in mole).

[0062] Another object of the present invention is the use of such metal halide-donor complexes as a catalyst for the polymerisation of unsaturated monomers, preferably for the cationic polymerisation of unsaturated monomers, more preferably of ethylenically unsaturated monomers, even more preferably of alkenes, and especially for isobutene-containing monomer mixtures.

[0063] Donor compounds (II) comprise at least one oxygen and / or nitrogen atom with at least one lone electron pair, preferably at least one oxygen atom with at least one lone electron pair and very preferably are selected from the group consisting of organic compounds with at least one ether function, organic compounds with at least one carboxylic ester function, organic compounds with at least one aldehyde function, organic compounds with at least one keto function, and organic compounds with at least one nitrogen containing heterocyclic ring.

[0064] Solely oxygen containing compounds (II) are preferred over nitrogen-containing compounds (II).

[0065] Preferably compound (II) is selected from the group consisting of organic compounds with at least one ether function, organic compounds with at least one carboxylic ester function and organic compounds with at least one keto function, more preferably selected from the group consisting of organic compounds with at least one ether function and organic compounds with at least one carboxylic ester function, very preferably compounds (II) are organic compounds with at least one ether function, and especially organic compounds with exactly one ether function.

[0066] Compounds with at least one ether function are also understood to mean acetals and hemiacetals. The ether compound may comprise one or more ether functions, e.g. one, two, three, four or even more ether functions, preferably one or two ether functions and very preferably one ether function. The mixture of donors may comprise one, two, three, four or even more different compounds (II), preferably compounds with at least one ether function, preferably one or two different compounds and very preferably one compound.

[0067] A further embodiment of the present invention is a metal halide-donor-complex which comprises as metal halide a mixture of

[0068] - at least one aluminium-containing first Lewis Acid of the formula

[0069] AI(ORa)p(Rb)qXr, wherein

[0070] Raand Rbindependently of another represent an organic residue of up to 20 carbon atoms, preferably Ci- to C2o-alkyl, Cs- to Cs-cycloalkyl radical, Cs- to C2o-aryl radical or Cy to C20- arylalkyl radical,

[0071] X independently of another represents halide, p independently of another represents a rational number of at least 0 (zero) and less than 3, q independently of another represents a rational number of at least 0 (zero) and less than 3, and r independently of another represents a rational number of greater than 0 (zero) up to 3, with the proviso that the sum of (p + q + r) is always 3 and

[0072] - at least one tin-containing second Lewis Acid selected from the group consisting of a tin dihalide and a tin tetrahalide, preferably selected from the group consisting of tin dichloride and tin tetrachloride, more preferably tin tetrachloride, and which comprises, as the donor,

[0073] - at least one dihydrocarbyl ether the general formula R8-O-R9in which the variables R8and R9are each independently Ci- to C2o-alkyl radicals, preferably Ci- to Cs alkyl radicals especially C1- to C4 alkyl radicals, Ci- to C2o-haloalkyl radicals, preferably Ci- to Cs haloalkyl radicals especially Ci- to C4 haloalkyl radicals, Cs- to Cs-cycloalkyl radicals, preferably Cs- to Cs-cycloalkyl radicals, Cs- to C2o-aryl radicals, especially Cs- to C12 aryl radicals, Cs- to C2o-haloaryl radicals, especially Cs- to C12 haloaryl radicals, or C7- to C2o-arylalkyl radicals, especially C7- to Ci2-arylalkyl radicals. Preference is given to Ci- to C4 alkyl radicals, Ci- to C4 haloalkyl radicals, Cs- to C12 aryl radicals, and C7- to Ci2-arylalkyl radicals.

[0074] Haloalkyl and haloaryl mean preferably chloroalkyl or bromoalkyl and chloroaryl or bromoaryl, very preferably chloroalkyl and chloroaryl. Especially preferred are w-haloalkyl radicals.

[0075] Preferred examples are chloromethyl, 1-chloroeth-1-yl, 2-chloroeth-1-yl, 2-chloroprop-1-yl, 2- chloroprop-2-yl, 3-chloroprop-1-yl, and 4-chlorobut-1-yl.

[0076] Preferred examples for chloroaryl are 2-chlorophenyl, 3-chlorophenyl, and 4-chlorophenyl.

[0077] The dihydrocarbyl ethers mentioned may be open-chain or cyclic, where the two variables R8and R9in the case of the cyclic ethers may join to form a ring, where such rings may also comprise two or three ether oxygen atoms. Examples of such open-chain and cyclic dihydrocarbyl ethers are dimethyl ether, chloromethyl methyl ether, bis (chloromethyl) ether, diethyl ether, chloromethyl ethyl ether, 2-chloroethyl ethyl ether (CEE), bis (2-chloroethyl) ether (CE), di-n- propyl ether, diisopropyl ether, di-n-butyl ether, di-sec-butyl ether, diisobutyl ether, di-n-pentyl ether, di-n-hexyl ether, di-n-heptyl ether, di-n-octyl ether, di-(2-ethylhexyl) ether, methyl n-butyl ether, methyl sec-butyl ether, methyl isobutyl ether, methyl tert-butyl ether, ethyl n-butyl ether, ethyl sec-butyl ether, ethyl isobutyl ether, ethyl tert-butyl ether, n-propyl-n-butyl ether, n-propyl sec-butyl ether, n-propyl isobutyl ether, n-propyl tert-butyl ether, isopropyl n-butyl ether, isopropyl sec-butyl ether, isopropyl isobutyl ether, isopropyl tert-butyl ether, methyl n-hexyl ether, methyl n-octyl ether, methyl 2-ethylhexyl ether, ethyl n-hexyl ether, ethyl n-octyl ether, ethyl 2- ethylhexyl ether, n-butyl n-octyl ether, n-butyl 2-ethylhexyl ether, tetrahydrofuran, tetrahydropyran, 1 ,2-, 1 ,3- and 1 ,4-dioxane, dicyclohexyl ether, diphenyl ether, alkyl aryl ethers, such as anisole and phenetole, ditolyl ether, dixylyl ether and dibenzyl ether.

[0078] Furthermore, difunctional ethers such as dialkoxybenzenes, preferably dimethoxybenzenes, very preferably veratrol, and ethylene glycol dialkylethers, preferably ethylene glycol dimethylether and ethylene glycol diethylether, are preferred. Among the dihydrocarbyl ethers mentioned, diethyl ether, 2-chloroethyl ethyl ether, diisopropyl ether, di-n-butyl ether and diphenyl ether have been found to be particularly advantageous as donors for the Lewis Acid-donor complexes according to the present invention.

[0079] In a peferred embodiment dihydrocarbyl ethers with at least one secondary or tertiary dihydrocarbyl group are preferred over dihydrocarbyl groups with primary groups only. Ethers with primary dihydrocarbyl groups are those ethers in which both dihydrocarbyl groups are bound to the ether functional group with a primary carbon atom, whereas ethers with at least one secondary or tertary dihydrocarbyl group are those ethers in which at least one dihydrocarbyl group is bound to the ether functional group with a secondary or tertiary carbon atom.

[0080] For the sake of clarity, e.g. diisobutyl ether is deemed to be an ether with primary dihydrocarbyl groups, since the secondary carbon atom of the isobutyl group is not bound to the oxygen of the functional ether group but the hydrocarbyl group is bound via a primary carbon atom.

[0081] Preferred examples for ethers with primary dihydrocarbyl groups are diethyl ether, di-n-butyl ether, and di-n-propyl ether.

[0082] Preferred examples for ethers with at least one secondary or tertary dihydrocarbyl group are diisopropyl ether, methyl tert-butyl ether, ethyl tert-butyl ether, and anisole.

[0083] In addition, particularly advantageous dihydrocarbyl ethers as donors for the Lews Acidcomplexes, have been found to be those in which the donor compound has a total carbon number of 3 to 16, preferably of 4 to 16, especially of 4 to 12, in particular of 4 to 8.

[0084] Organic compounds with at least one carboxylic ester function are preferably hydrocarbyl carboxylates of the general formula R10-COOR11in which the variables R10and R11are each independently Ci- to C2o-alkyl radicals, especially Ci- to Cs alkyl radicals, Cs- to Cs-cycloalkyl radicals, Cs- to C2o-aryl radicals, especially Cs- to C12 aryl radicals, or C7- to C2o-arylalkyl radicals, especially C7- to Ci2-arylalkyl radicals.

[0085] Examples of the hydrocarbyl carboxylates mentioned are methyl formate, ethyl formate, n-pro- pyl formate, isopropyl formate, n-butyl formate, sec-butyl formate, isobutyl formate, tert-butyl formate, methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, secbutyl acetate, isobutyl acetate, tert-butyl acetate, methyl propionate, ethyl propionate, n-propyl propionate, isopropyl propionate, n-butyl propionate, sec-butyl propionate, isobutyl propionate, tert-butyl propionate, methyl butyrate, ethyl butyrate, n-propyl butyrate, isopropyl butyrate, n-bu- tyl butyrate, sec-butyl butyrate, isobutyl butyrate, tert-butyl butyrate, methyl cyclohexanecarboxylate, ethyl cyclohexanecarboxylate, n-propyl cyclohexanecarboxylate, isopropyl cyclohexanecarboxylate, n-butyl cyclohexanecarboxylate, sec-butyl cyclohexanecarboxylate, isobutyl cyclohexanecarboxylate, tert-butyl cyclohexanecarboxylate, methyl benzoate, ethyl benzoate, n-pro- pyl benzoate, isopropyl benzoate, n-butyl benzoate, sec-butyl benzoate, isobutyl benzoate, tertbutyl benzoate, methyl phenylacetate, ethyl phenylacetate, n-propyl phenylacetate, isopropyl phenylacetate, n-butyl phenylacetate, sec-butyl phenylacetate, isobutyl phenylacetate and tertbutyl phenylacetate. Among the hydrocarbyl carboxylates mentioned, ethyl acetate has been found to be particularly advantageous as a donor for the complexes.

[0086] In addition, particularly advantageous hydrocarbyl carboxylates as donors, have been found to be those in which the donor compound has a total carbon number of 3 to 16, preferably of 4 to 16, especially of 4 to 12, in particular of 4 to 8, preference is given in particular to those having a total of 3 to 10 and especially 4 to 6 carbon atoms.

[0087] Organic compounds with at least one aldehyde function, preferably exactly one aldehyde function and organic compounds with at least one keto function, preferably exactly one keto function typically have from 1 to 20, preferably from 2 to 10 carbon atoms. Functional groups other than the carbonyl group are preferably absent.

[0088] Preferred organic compounds with at least one aldehyde function are those of formula R10-CHO, in which R10has the above-mentioned meaning, very preferably are selected from the group consisting of formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, and benzaldehyde.

[0089] Preferred organic compounds with at least one keto function are those of formula R10-(C=O)- R11, in which R10and R11have the above-mentioned meaning, very preferably are selected from the group consisting of acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, cyclohexanone, acetophenone, and benzophenone. Greatest preference is given to acetone. Organic compounds with at least one nitrogen containing heterocyclic ring are preferably saturated, partly unsaturated or unsaturated nitrogen-containing five-membered or six-membered heterocyclic rings which comprises one, two or three ring nitrogen atoms and may have one or two further ring heteroatoms from the group of oxygen and sulphur and / or hydrocarbyl radicals, especially Ci- to C4-alkyl radicals and / or phenyl, and / or functional groups or heteroatoms as substituents, especially fluorine, chlorine, bromine, nitro and / or cyano, for example pyrrolidine, pyrrole, imidazole, 1 ,2,3- or 1 ,2,4-triazole, oxazole, thiazole, piperidine, pyrazane, pyrazole, pyridazine, pyrimidine, pyrazine, 1 ,2,3-, 1 ,2,4- or 1 ,2,5-triazine, 1 ,2,5-oxathiazine, 21-1-1 ,3,5- thiadiazine or morpholine.

[0090] However, a very particularly suitable nitrogen-containing basic compound of this kind is pyridine or a derivative of pyridine (especially a mono-, di- or tri-Ci- to C4-alkyl-substituted pyridine) such as 2-, 3-, or 4-methylpyridine (picolines), 2,3-, 2,4-, 2,5-, 2,6-, 3,4-, 3,5- or 3,6-dimethylpyridine (lutidines), 2,4,6-trimethylpyridine (collidine), 2-, 3,- or 4-tert-butylpyridine, 2-tert-butyl-6-methyl- pyridine, 2,4-, 2,5-, 2,6- or 3,5-di-tert-butylpyridine or else 2-, 3,- or 4-phenylpyridine.

[0091] The molar ratio of the mixture of Lewis Acids (in sum) to the isobutene monomer used in the case of homopolymerization of isobutene, or to the total amount of the polymerizable monomers used in the case of copolymerization of isobutene, based on each individual functional sites of the Lewis Acids is generally from 0.001 :1 to 0.2:1 , preferably 0.002:1 to 0.1 : 1 , very preferably 0.003:1 to 0.08:1 , especially 0.005:1 to 0.05:1 , and in particular 0.007:1 to 0.03:1.

[0092] Typically, the Lewis Acids-donor complex is prepared separately prior to the polymerization from the respective metal halides and the donor compound, and is then - usually dissolved in an inert solvent such as a halogenated hydrocarbon, for example dichloromethane, or more preferably in unhalogenated hydrocarbons - added to the polymerization medium. However, in a less preferred embodiment the complex can also be prepared in situ prior to the polymerization.

[0093] In case the polymerization catalyst is not fully soluble in the solvent used it may be advantageous to disperse the polymerization catalyst in the inert solvent, e.g. by vigorously stirring the dispersion. The dispersing can be effected in any apparatus suitable for dispersing. Shaking apparatuses such as for example from Skandex may be mentioned by way of example or for example in ultrasonic apparatuses, high pressure homogenizers, 2-, 3-, 4- or 5-roll mills, minimills, Henschel mixers, shaking mills, Ang mills, gear mills, bead mills, wet mills, sand mills, attritors, colloid mills, ultrasonic homogenizers, with Ultra Turrax stirrer and in particular by grinding, for example in 2-, 3-, 4- or 5-roll mills, minimills, shaking mills, Ang mills, gear mills, bead mills, wet mills, sand mills, colloid mills, ball mills, specifically stirred ball mills.

[0094] In a preferred embodiment of the present invention, the polymerization is performed with additional use of a mono- or polyfunctional, especially mono-, di- or trifunctional, initiator which is selected from organic hydroxyl compounds, organic halogen compounds and water. It is also possible to use mixtures of the initiators mentioned, for example mixtures of two or more organic hydroxyl compounds, mixtures of two or more organic halogen compounds, mixtures of one or more organic hydroxyl compounds and one or more organic halogen compounds, mixtures of one or more organic hydroxyl compounds and water, or mixtures of one or more organic halogen compounds and water. The initiator may be mono-, di- or polyfunctional, i.e. one, two or more hydroxyl groups or halogen atoms, which start the polymerization reaction, may be present in the initiator molecule. In the case of di- or polyfunctional initiators, telechelic isobutene polymers with two or more, especially two or three, polyisobutene chain ends are typically obtained.

[0095] Organic hydroxyl compounds which have only one hydroxyl group in the molecule and are suitable as monofunctional initiators include especially alcohols and phenols, in particular those of the general formula R12-OH, in which R12denotes Ci- to C2o-alkyl radicals, especially Ci- to Cs- alkyl radicals, Cs- to Cs-cycloalkyl radicals, Ce- to C2o-aryl radicals, especially Ce- to Ci2-aryl radicals, or Cy to C2o-arylalkyl radicals, especially Cy to Ci2-arylalkyl radicals. In addition, the R12radicals may also comprise mixtures of the abovementioned structures and / or have other functional groups than those already mentioned, for example a keto function, a nitroxide or a carboxyl group, and / or heterocyclic structural elements.

[0096] Typical examples of such organic monohydroxyl compounds are methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, isobutanol, tert-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, 2-ethylhexanol, cyclohexanol, phenol, p-methoxyphenol, o-, m- and p-cresol, benzyl alcohol, p-methoxybenzyl alcohol, 1- and 2-phenylethanol, 1- and 2-(p-methoxyphenyl)ethanol, 1-, 2- and 3-phenyl-1-propanol, 1-, 2- and 3-(p-methoxyphenyl)-1-propanol, 1- and 2-phenyl-2- propanol, 1- and 2-(p-methoxyphenyl)-2-propanol, 1-, 2-, 3- and 4-phenyl-1-butanol, 1-, 2-, 3- and 4-(p-methoxyphenyl)-1-butanol, 1-, 2-, 3- and 4-phenyl-2-butanol, 1-, 2-, 3- and 4-(p-me- thoxyphenyl)-2-butanol, 9-methyl-9H-fluoren-9-ol, 1 ,1 -diphenylethanol, 1 ,1-diphenyl-2-propyn-1- ol, 1 ,1 -diphenylpropanol, 4-(1 -hydroxy-1 -phenylethyl)benzonitrile, cyclopropyldiphenylmethanol, 1 -hydroxy-1 , 1-diphenylpropan-2-one, benzilic acid, 9-phenyl-9-fluorenol, triphenylmethanol, diphenyl(4-pyridinyl)methanol, alpha, alpha-diphenyl-2-pyridinemethanol, 4-methoxytrityl alcohol (especially polymer-bound as a solid phase), alpha-tert-butyl-4-chloro-4’-methylbenzhydrol, cyclohexyldiphenylmethanol, alpha-(p-tolyl)-benzhydrol, 1 ,1 ,2-triphenylethanol, alpha, alpha- diphenyl-2-pyridineethanol, alpha, alpha-4-pyridylbenzhydrol N-oxide, 2-fluorotriphenylmethanol, triphenylpropargyl alcohol, 4-[(diphenyl)hydroxymethyl]benzonitrile, 1-(2,6-dimethoxyphenyl)-2- methyl-1-phenyl-1 -propanol, 1 ,1 ,2-triphenylpropan-1-ol and p-anisaldehyde carbinol.

[0097] Organic hydroxyl compounds which have two hydroxyl groups in the molecule and are suitable as bifunctional initiators are especially dihydric alcohols or diols having a total carbon number of 2 to 30, especially of 3 to 24, in particular of 4 to 20, and bisphenols having a total carbon number of 6 to 30, especially of 8 to 24, in particular of 10 to 20, for example ethylene glycol, 1 ,2- and 1 ,3-propylene glycol, 1 ,4-butylene glycol, 1 ,6-hexylene glycol, 1 ,2-, 1 ,3- or 1 ,4-bis(1- hydroxy-1-methylethyl)benzene (o-, m- or p-dicumyl alcohol), bisphenol A, 9,10-di-hydro-9,10- dimethyl-9,10-anthracenediol, 1 ,1-diphenylbutane-1 ,4-diol, 2-hydroxytriphenylcarbinol and 9-[2- (hydroxymethyl)phenyl]-9-fluorenol.

[0098] Organic halogen compounds which have one halogen atom in the molecule and are suitable as monofunctional initiators are in particular compounds of the general formula R13-Hal in which Hal is a halogen atom selected from fluorine, iodine and especially chlorine and bromine, and R13denotes Ci- to C2o-alkyl radicals, especially Ci- to Cs-alkyl radicals, Cs- to Cs-cycloalkyl radicals or C7- to C2o-arylalkyl radicals, especially C7- to Ci2-arylalkyl radicals. In addition, the R13radicals may also comprise mixtures of the abovementioned structures and / or have other functional groups than those already mentioned, for example a keto function, a nitroxide or a carboxyl group, and / or heterocyclic structural elements.

[0099] Typical examples of such monohalogen compounds are methyl chloride, methyl bromide, ethyl chloride, ethyl bromide, 1 -chloropropane, 1 -bromopropane, 2-chloropropane, 2-bromopropane, 1 -chlorobutane, 1 -bromobutane, sec-butyl chloride, sec-butyl bromide, isobutyl chloride, isobutyl bromide, tert-butyl chloride, tert-butyl bromide, 1 -chloropentane, 1 -bromopentane, 1 -chloro- hexane, 1 -bromohexane, 1 -chloroheptane, 1 -bromoheptane, 1 -chlorooctane, 1 -bromooctane, 1- chloro-2-ethylhexane, 1-bromo-2-ethylhexane, cyclohexyl chloride, cyclohexyl bromide, benzyl chloride, benzyl bromide, 1-phenyl-1 -chloroethane, 1-phenyl-1 -bromoethane, 1-phenyl-2-chloro- ethane, 1-phenyl-2-bromoethane, 1-phenyl-1 -chloropropane, 1-phenyl-1 -bromopropane, 1-phe- nyl-2-chloropropane, 1-phenyl-2-bromopropane, 2-phenyl-2-chloropropane, 2-phenyl-2-bromo- propane, 1-phenyl-3-chloropropane, 1-phenyl-3-bromopropane, 1-phenyl-1 -chlorobutane, 1- phenyl-1 -bromobutane, 1-phenyl-2-chlorobutane, 1-phenyl-2-bromobutane, 1-phenyl-3-chloro- butane, 1-phenyl-3-bromobutane, 1-phenyl-4-chlorobutane, 1-phenyl-4-bromobutane, 2-phenyl-

[0100] 1 -chlorobutane, 2-phenyl-1 -bromobutane, 2-phenyl-2-chlorobutane, 2-phenyl-2-bromobutane,

[0101] 2-phenyl-3-chlorobutane, 2-phenyl-3-bromobutane, 2-phenyl-4-chlorobutane and 2-phenyl-4- bromobutane.

[0102] Organic halogen compounds which have two halogen atoms in the molecule and are suitable as difunctional initiators are, for example, 1 ,3-bis(1-bromo-1-methylethyl)benzene, 1 ,3-bis(2-chloro- 2-propyl)benzene (1 ,3-dicumyl chloride) and 1 ,4-bis(2-chloro-2-propyl)benzene (1 ,4-dicumyl chloride).

[0103] The initiator is more preferably selected from organic hydroxyl compounds in which one or more hydroxyl groups are each bonded to an sp3-hybridized carbon atom, organic halogen compounds, in which one or more halogen atoms are each bonded to an sp3-hybridized carbon atom, and water. Among these, preference is given in particular to an initiator selected from organic hydroxyl compounds in which one or more hydroxyl groups are each bonded to an sp3- hybridized carbon atom.

[0104] In the case of the organic halogen compounds as initiators, particular preference is further given to those in which the one or more halogen atoms are each bonded to a secondary or especially to a tertiary sp3-hybridized carbon atom.

[0105] Preference is given in particular to initiators which may bear, on such an sp3-hydridized carbon atom, in addition to the hydroxyl group, the R12, R13and R14radicals, which are each independently hydrogen, Ci- to C2o-alkyl, C5- to Cs-cycloalkyl, Cs- to C2o-aryl, C7- to C2o-alkylaryl or phenyl, where any aromatic ring may also bear one or more, preferably one or two, Ci- to C4- alkyl, Ci- to C4-alkoxy, Ci- to C4-hydroxyalkyl or Ci- to C4-haloalkyl radicals as substituents, where not more than one of the variables R , R13and R14is hydrogen and at least one of the variables R12, R13and R14is phenyl which may also bear one or more, preferably one or two, Ci- to C4-alkyl, Ci- to C4-alkoxy, Ci- to C4-hydroxyalkyl or Ci- to C4-haloalkyl radicals as substituents.

[0106] For the present invention, very particular preference is given to initiators selected from water, methanol, ethanol, 1-phenylethanol, 1-(p-methoxyphenyl)ethanol, n-propanol, isopropanol, 2- phenyl-2-propanol (cumene), n-butanol, isobutanol, sec.-butanol, tert-butanol, 1-phenyl-1- chloroethane, 2-phenyl-2-chloropropane (cumyl chloride), tert-butyl chloride and 1 ,3- or 1 ,4- bis(1 -hydroxy-1 -methylethyl)benzene. Among these, preference is given in particular to initiators selected from water, methanol, ethanol, 1-phenylethanol, 1-(p-methoxyphenyl)ethanol, n-pro- panol, isopropanol, 2-phenyl-2-propanol (cumene), n-butanol, isobutanol, sec.-butanol, tertbutanol, 1-phenyl-1 -chloroethane and 1 ,3- or 1 ,4-bis(1 -hydroxy-1 -methylethyl)benzene.

[0107] The molar ratio of the initiators mentioned to the isobutene monomer used in the case of homopolymerization of isobutene, or to the total amount of the polymerizable monomers used in the case of copolymerization of isobutene, based on each individual functional site of the initiator, is generally from 0.0005:1 to 0.1 :1 , especially 0.001 :1 to 0.075:1 , in particular 0.0025:1 to 0.05:1. When water is used as the sole initiator or in combination with organic hydroxyl compounds and / or organic halogen compounds as further initiators, the molar ratio of water to the isobutene monomer used in the case of homopolymerization of isobutene, or to the total amount of the polymerizable monomers used in the case of copolymerization of isobutene, is especially from 0.0001 :1 to 0.1 :1 , in particular 0.0002:1 to 0.05:1 , preferably 0.0008:1 to 0.04:1 , and very preferably in particular 0.001 :1 to 0.03:1.

[0108] In a preferred embodiment the amount of initiator in the monomer mixture is not more than 10 wt%, preferably not more than 7.5 wt%, more preferably not more than 5 wt%, even more preferably not more than 3 wt%, and especially not more than 2 wt%.

[0109] If water is used as the sole initiator or in combination with organic hydroxyl compounds the amount of initiator in the monomer mixture is not more than 3.2 wt%, preferably not more than 2.5 wt%, more preferably not more than 2 wt%, even more preferably not more than 1 .5 wt%, and especially not more than 1 wt%.

[0110] A proportion of the initiator molecules added as organic hydroxyl or halogen compounds is incorporated into the polymer chains. The proportion (left) of polymer chains which are started by such an incorporated organic initiator molecule may be up to 100%, and is generally 5 to 90%. The remaining polymer chains arise either from water originating from traces of moisture as an initiator molecule, or from chain transfer reactions.

[0111] In a further preferred embodiment of the present invention, the polymerization is performed in the presence of 0.01 to 10 mmol, especially of 0.05 to 5.0 mmol, in particular of 0.1 to 1.0 mmol, based in each case on 1 mol of isobutene monomer used in the case of homopolymerization of isobutene, or on 1 mol of the total amount of the polymerizable monomers used in the case of copolymerization of isobutene, of a nitrogen-containing basic compound.

[0112] Such a nitrogen-containing basic compound used may be an aliphatic, cycloaliphatic or aromatic amine of the general formula R14-NR15R16, or else ammonia, in which the variables R14, R15and R16are each independently hydrogen, Ci- to C2o-alkyl radicals, especially Ci- to Cs-alkyl radicals, Cs- to Cs-cycloalkyl radicals, Ce- to C2o-aryl radicals, especially Ce- to Ci2-aryl radicals, or C7- to C2o-arylalkyl radicals, especially C7- to Ci2-arylalkyl radicals. When none of these variables is hydrogen, the amine is a tertiary amine. When one of these variables is hydrogen, the amine is a secondary amine. When two of these variables is hydrogen, the amine is a primary amine. When all these variables are hydrogen, the amine is ammonia.

[0113] Typical examples of such amines of the general formula R14-NR15R16are methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, tert-butylamine, sec-butylamine, isobutylamine, tert-amylamine, n-hexylamine, n-heptylamine, n-octylamine, 2-ethylhexylamine, cyclopentylamine, cyclohexylamine, aniline, dimethylamine, diethylamine, di-n-propylamine, diisopropylamine, di-n-butylamine, di-tert-butylamine, di-sec-butylamine, diisobutylamine, di-tert- amylamine, di-n-hexylamine, di-n-heptylamine, di-n-octylamine, di-(2-ethylhexyl)amine, dicyclopentylamine, dicyclohexylamine, diphenylamine, trimethylamine, triethylamine, tri-n-propyl- amine, tri-isopropylamine, tri-n-butylamine, tri-tert-butylamine, tri-sec-butylamine, tri-isobutyl- amine, tri-tert-amylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-(2-ethylhexyl)- amine, tricyclopentylamine, tricyclohexylamine, triphenylamine, dimethylethylamine, methyl-n- butylamine, N-methyl-N-phenylamine, N,N-dimethyl-N-phenylamine, N-methyl-N,N- diphenylamine or N-methyl-N-ethyl-N-n-butylamine.

[0114] In addition, such a nitrogen-containing basic compound used may also be a compound having a plurality of, especially having two or three, nitrogen atoms and having 2 to 20 carbon atoms, where these nitrogens may each independently bear hydrogen atoms or aliphatic, cycloaliphatic or aromatic substituents. Examples of such polyamines are 1,2-ethylenediamine, 1,3-propylene- diamine, 1,4-butylenediamine, diethylenetriamine, N-methyl-1,2-ethylenediamine, N,N-dimethyl- 1 ,2-ethylenediamine, N,N’-dimethyl-1,2-ethylenediamine or N,N-dimethyl-1,3-propylenediamine.

[0115] However, a suitable nitrogen-containing basic compound of this kind is especially a saturated, partly unsaturated or unsaturated nitrogen-containing five-membered or six-membered heterocyclic ring which comprises one, two or three ring nitrogen atoms and may have one or two further ring heteroatoms from the group of oxygen and sulphur and / or hydrocarbyl radicals, especially Ci- to C4-alkyl radicals and / or phenyl, and / or functional groups or heteroatoms as substituents, especially fluorine, chlorine, bromine, nitro and / or cyano, for example pyrrolidine, pyrrole, imidazole, 1 ,2,3- or 1 ,2,4-triazole, oxazole, thiazole, piperidine, pyrazane, pyrazole, pyridazine, pyrimidine, pyrazine, 1 ,2,3-, 1 ,2,4- or 1,2,5-triazine, 1,2,5-oxathiazine, 2H-1,3,5-thiadiazine or morpholine.

[0116] However, a very particularly suitable nitrogen-containing basic compound of this kind is pyridine or a derivative of pyridine (especially a mono-, di- or tri-Ci- to C4-alkyl-substituted pyridine) such as 2-, 3-, or 4-methylpyridine (picolines), 2,3-, 2,4-, 2,5-, 2,6-, 3,4-, 3,5- or 3,6-dimethylpyridine (lutidines), 2,4,6-trimethylpyridine (collidine), 2-, 3,- or 4-tert-butylpyridine, 2-tert-butyl-6-methyl- pyridine, 2,4-, 2,5-, 2,6- or 3,5-di-tert-butylpyridine or else 2-, 3,- or 4-phenylpyridine.

[0117] It is possible to use a single nitrogen-containing basic compound or mixtures of such nitrogencontaining basic compounds.

[0118] For the preparation of the polymer isobutene or an isobutene-containing monomer mixture is polymerized, suitable isobutene sources are C4 cuts, more particularly, pure isobutene which generally comprises at most 0.5% by volume of residual impurities such as othe C4-isomers, especially butadiene, 1 -butene, 2-butenes, butane, water and / or Ci- to C4-alkanols.

[0119] The raw material of C4 compounds may be selected from the group consisting of

[0120] (a) a C4 compound material in which an isobutene amount is adjusted to 50 to 75% by weight, obtained by adding high purity isobutene having the isobutene amount of 90 to 100% by weight to C4 raffinate-1 which is a remainder after extracting 1,3-butadiene from a C4 compound derived during a naphtha degrading process;

[0121] (b) a C4 compound material in which an isobutene amount is adjusted to 50 to 75% by weight, obtained by adding high amount isobutene mixture having isobutene amount of 80 to 97% by weight, which is generated in an olefin conversion unit (OCU) process that produces propylene by the metathesis of ethylene and 2-butene, to C4 raffinate-1 which is a remainder after extracting 1 ,3-butadiene from a C4 compound derived during a naphtha degrading process;

[0122] (c) a C4 compound material in which an isobutene amount is adjusted to 50 to 75% by weight, obtained by adding high purity isobutene having the isobutene amount of 90 to 100% by weight to butane-butene oil (B-B oil) derived from crude oil refining process;

[0123] (d) a C4 compound material in which an isobutene amount is adjusted to 50 to 75% by weight, obtained by adding high amount isobutene mixture having the isobutene amount of 80 to 97% by weight, which is generated in an olefin conversion unit (OCU) process that produces propylene by the metathesis of ethylene and 2-butene, to butane-butene oil (B-B oil) derived from crude oil refining process;

[0124] (e) a C4 compound material in which an isobutene amount is adjusted to 50 to 75% by weight, obtained by adding a dilute solvent to high purity isobutene having an isobutene amount of 90 to 100% by weight;

[0125] (f) a C4 compound material in which an isobutene amount is adjusted to 50 to 75% by weight, obtained by adding a dilute solvent to high amount isobutene mixture having the isobutene amount of 80 to 97% by weight, which is generated in an olefin conversion unit (OCU) process that produces propylene by the metathesis of ethylene and 2-butene;

[0126] (g) a C4 compound material in which an isobutene amount is adjusted to 50 to 75% by weight, obtained by adding high purity isobutene having the isobutene amount of 90 to 100% by weight to a mixture generated in dehydrogenation reaction that converts isobutane to isobutene; and

[0127] (h) a C4 compound material in which an isobutene amount is adjusted to 50 to 75% by weight, obtained by adding high amount isobutene mixture having the isobutene amount of 80 to 97% by weight, which is generated in an olefin conversion unit (OCU) process that produces propyl- ene by the metathesis of ethylene and 2-butene to a mixture generated in dehydrogenation reaction that converts isobutane to isobutene.

[0128] For the use of isobutene or of an isobutene-comprising monomer mixture as the monomer to be polymerized, suitable isobutene sources are both pure isobutene and isobutenic C4 hydrocarbon streams, for example C4 raffinates, especially "raffinate 1", C4 cuts from isobutane dehydrogenation, C4 cuts from steam crackers and from FCC crackers (fluid catalyzed cracking), provided that they have been substantially freed of 1 ,3-butadiene present therein. A C4 hydrocarbon stream from an FCC refinery unit is also known as "b / b" stream. Further suitable isobutenic C4 hydrocarbon streams are, for example, the product stream of a propylene-isobutane cooxidation or the product stream from a metathesis unit, which are generally used after customary purification and / or concentration. Suitable C4 hydrocarbon streams generally comprise less than 500 ppm, preferably less than 200 ppm, of butadiene. The presence of 1-butene and of cis- and trans-2-butene is substantially uncritical. Typically, the isobutene concentration in the C4 hydrocarbon streams mentioned is in the range from 40 to 60% by weight. For instance, raffinate 1 generally consists essentially of 30 to 50% by weight of isobutene, 10 to 50% by weight of 1- butene, 10 to 40% by weight of cis- and trans-2-butene, and 2 to 35% by weight of butanes; in the polymerization process according to the invention, the unbranched butenes in the raffinate 1 generally behave virtually inertly, and only the isobutene is polymerized.

[0129] In a preferred embodiment, the monomer source used for the polymerization is a technical C4 hydrocarbon stream with an isobutene content of 1 to 100% by weight, especially of 1 to 99% by weight, in particular of 1 to 90% by weight, more preferably of 30 to 60% by weight, especially a raffinate 1 stream, a b / b stream from an FCC refinery unit, a product stream from a propylene-isobutane cooxidation or a product stream from a metathesis unit.

[0130] Since 1 ,3-butadiene is unwanted in the isobutenic monomer feed, the content of butadienes, especially 1 ,3-butadiene, can preferably further be reduced by selective hydrogenation in which butadienes are hydrogenated to butenes, especially 1-butene. Furthermore, butenes may also be hydrogenated, however, the content of isobutene remains essentially unchanged.

[0131] The isobutenic monomer mixture mentioned may comprise small amounts of contaminants such as water, carboxylic acids or mineral acids, without there being any critical yield or selectivity losses. It is appropriate to prevent enrichment of these impurities by removing such harmful substances from the isobutenic monomer mixture, for example by adsorption on solid adsorbents such as activated carbon, molecular sieves or ion exchangers.

[0132] It is also possible to convert monomer mixtures of isobutene or of the isobutenic hydrocarbon mixture with olefinically unsaturated monomers copolymerizable with isobutene. When monomer mixtures of isobutene are to be copolymerized with suitable comonomers, the monomer mixture preferably comprises at least 5% by weight, more preferably at least 10% by weight and especially at least 20% by weight of isobutene, and preferably at most 95% by weight, more preferably at most 90% by weight and especially at most 80% by weight of comonomers.

[0133] Useful copolymerizable monomers include: vinylaromatics such as styrene and a-methylstyrene, Ci- to C4-alkylstyrenes such as 2-, 3- and 4-methylstyrene, and 4-tert-butylsty- rene, halostyrenes such as 2-, 3- or 4-chlorostyrene, and isoolefins having 5 to 10 carbon atoms, such as 2-methylbutene-1 , 2-methylpentene-1 , 2- methylhexene-1 , 2-ethylpentene-1 , 2-ethylhexene-1 and 2-propylheptene-1. Further useful comonomers include olefins which have a silyl group, such as 1 -trimethoxysilylethene, 1- (trimethoxysilyl)propene, 1 -(trimethoxysilyl)-2-methylpropene-2, 1 -[tri(methoxyethoxy)- silyl]ethene, 1-[tri(methoxyethoxy)silyl]propene, and 1-[tri(methoxyethoxy)silyl]-2-methylpro- pene-2. In addition - depending on the polymerization conditions - useful comonomers also include isoprene, 1-butene and cis- and trans-2-butene.

[0134] When the process according to the invention is to be used to prepare copolymers, the process can be configured so as to preferentially form random polymers or to preferentially form block copolymers. To prepare block copolymers, for example, the different monomers can be supplied successively to the polymerization reaction, in which case the second comonomer is especially not added until the first comonomer is already at least partly polymerized. In this manner, diblock, triblock and higher block copolymers are obtainable, which, according to the sequence of monomer addition, have a block of one or the other comonomer as a terminal block. In some cases, however, block copolymers also form when all comonomers are supplied to the polymerization reaction simultaneously, but one of them polymerizes significantly more rapidly than the other(s). This is the case especially when isobutene and a vinylaromatic compound, especially styrene, are copolymerized in the process according to the invention. This preferably forms block copolymers with a terminal polystyrene block. This is attributable to the fact that the vi- nylaromatic compound, especially styrene, polymerizes significantly more slowly than isobutene.

[0135] The isobutene or the isobutene containing C4 hydrocarbon stream can at least partially, preferably completely, originate from renewable sources, as described for example in WO 2012 / 40859 A1 , particularly from page 5, line 9 to page 6, line 24. The proportion of isobutene from renewable sources in the total amount of isobutene used, measured according to ASTM D 6866 as described in WO 2012 / 40859 A1 , is advantageously at least 1 wt%, preferably at least 2 wt%, particularly preferably at least 10 wt%, especially preferably at least 25 wt%, and specifically at least 50 wt%. The proportion of isobutene from renewable sources can be up to 100 wt%, preferably up to 95 wt%, particularly preferably up to 90 wt%, especially preferably up to 85 wt%, and specifically up to 80 wt%.

[0136] In a preferred embodiment of the present invention, the isobutene used in the isobutene- comprising monomer mixture resp. in the polyisobutene has a biobased fraction, measured as a14C:12C ratio ASTM-D6866, of more than 0%, preferably at least 1%, particularly preferably at least 5%, even more preferably at least 10%, especially at least 20%, and specifically at least 25%.

[0137] Advantageously, this biobased fraction can be at least 30%, preferably at least 40%, particularly preferably at least 50%, even more preferably at least 66%, especially at least 75%, and specifically at least 85%.

[0138] At a fraction of at least 90%, preferably at least 95%, particularly preferably at least 98%, and even 100%, this can be referred to as significantly predominant or completely biobased isobutene.

[0139] According to this embodiment, resources are conserved and the product is produced at least partially with renewable raw materials.

[0140] In another embodiment of the present invention, the isobutene used in the polymerization can be obtained entirely from renewable raw materials or consist of mixtures of isobutene from renewable and fossil sources.

[0141] The latter embodiment is particularly preferred as long as isobutene from renewable sources is not available in industrially sufficient quantities and economically viable.

[0142] The terms "renewable" or "bio-based" used herein with regard to a material or a compound (such as alcohols, alkyl, olefins, di-olefins, etc.) denote a material or compound obtained from a "new carbon" source as measured by ASTM test method designated as D 6866, "Determining the Biobased Content of Natural Range Materials Using Radiocarbon and Isotope Ratio Mass Spectrometry Analysis", incorporated herein by reference in its entirety. This test method measures the14C / 2C isotope ratio in a sample and compares it to the14C / 12Cisotope ratio in a standard 100% bio-based material to give percent biobased content of the sample.

[0143] "Renewable" or "bio-based" compounds can be prepared from biomass using thermochemical methods (e.g., Fischer-Tropsch catalysts), biocatalysts (e.g., fermentation), or other processes.

[0144] All types of polymers made with the isobutene of this invention are verifiable as being made with isobutene that did not originate from a petrochemical source. Additionally, the isobutene containing polymers of this invention can also be distinguished from isobutene containing polymers that come from natural sources, such as natural rubber. Accordingly, the isobutene containing polymers of this invention are analytically verifiable as coming from the bio- renewable, environmentally friendly sources. Assessment of the renewably based carbon content of a material can be performed through standard test methods, e.g. using radiocarbon and isotope ratio mass spectrometry analysis. ASTM International (formally known as the American Society for Testing and Materials) has established a standard method for assessing the biobased content of materials. The ASTM method is designated ASTM-D6866.

[0145] The application of ASTM-D6866 to derive "biobased content" is built on the same concepts as radiocarbon dating, but without use of the age equations. The analysis is performed by deriving a ratio of the amount of radiocarbon (14C) in an unknown sample compared to that of a modern reference standard. This ratio is reported as a percentage with the units "pMC"(percent modern carbon). If the material being analyzed is a mixture of present day radiocarbon and fossil carbon (containing very low levels of radiocarbon), then the pMC value obtained correlates directly to the amount of biomass material present in the sample. "Biobased materials" are organic materi- als in which the carbon comes from recently (on a human time scale) fixated CO2 present in the atmosphere using sunlight energy (photosynthesis). On land, this CO2 is captured or fixated by plant life (e.g., agricultural crops or forestry materials). In the oceans, the CO2 is captured or fixated by photosynthesizing bacteria or phytoplankton. For example, a biobased material has a14C / 12C isotope ratio greater than 0. Contrarily, a fossil-based material, has a14C / 12C isotope ratio of about 0.

[0146] A small amount of the carbon atoms of the carbon dioxide in the atmosphere is the radioactive isotope14C, which is created when atmospheric nitrogen is struck by a cosmic ray generated neutron, causing the nitrogen to lose a proton and form carbon of atomic mass 14 (14C), which is then immediately oxidized to carbon dioxide. A small but measurable fraction of atmospheric carbon is present in the form of14CC>2. Atmospheric carbon dioxide is processed by green plants to make organic molecules during the process known as photosynthesis. Virtually all forms of life on Earth depend on this green plant production of organic molecules to produce the chemical energy that facilitates growth and reproduction. Therefore, the14C that forms in the atmosphere eventually becomes part of all life forms and their biological products, enriching biomass and organisms which feed on biomass with14C. In contrast, carbon from fossil fuels does not have the signature14C:12C ratio of renewable organic molecules derived from atmospheric carbon dioxide.

[0147] To achieve a desired biobased content in an isobutene-based polymer, the mixture ratio of biobased isobutene to petroleum based isobutene in the polymer may be varied. In one embodiment, the biobased content for the isobutene-based elastomer of the present invention is greater than 0%. In another embodiment, the biobased content for the isobutene-based elastomer is greater than 20%. In another embodiment, the biobased content for the isobutene-based elastomer is greater than 40%. In another embodiment, the biobased content for the isobutene- based elastomer is greater than 60%. In another embodiment, the biobased content for the iso- butene-based elastomer is greater than 80%. In another embodiment, the biobased content for the isobutene-based elastomer is greater than 90%. Alternatively or additionally, the multiolefin content of the final polymer can be modified by adjusting the multiolefin monomer feed for the polymerization reaction. For example, 4 mol% (petroleum-based isoprene, renewable isoprene or mixtures thereof) incorporation of isoprene into the final butyl polymer would result in a biobased content of between 5 to 95% (ASTM D6866). As another example, 0.9 mol% (petroleum-based isoprene, renewable isoprene or mixtures thereof) incorporation of isoprene into the final butyl polymer would result in a biobased content of between 1 to 99% (ASTM D6866). Polymerization of a butyl rubber polymer using biobased isoprene and bio-isobutene will yield a bio-butyl rubber with a bio-based content of 100% (ASTM D6866).

[0148] The present invention also relates to a method for verifying that a polymer having repeating units derived from isobutene contains isobutene that is obtained from a renewable non- petroleum derived hydrocarbon source. This method involves (a) determining the biobased content of the polymer; and (b) verifying that the polymer is from a renewable non-petroleum derived source if the biobased content (as described in ASTM D6866) of greater than 0%.

[0149] The verification method can be applied to homopolymers or copolymer of isobutene. In one embodiment, the method relates to verifying if a block copolymer having repeating units derived from isobutene contains isobutene that is from a renewable, sustainable non- petroleum derived source which comprises: (a) determining the percent modern carbon of at least one polyisobutene block in the copolymer; and (b) verifying that the isobutene from the copolymer is from a renewable, sustainable non-petroleum derived source if polyisobutene block has a total biobased content (ASTM D6866-08) greater than 0%.

[0150] The polymerization of isobutene or the isobutene-containing C4-mixture can be effected either continuously or batchwise. Continuous processes can be performed in analogy to known prior art processes for continuous polymerization of isobutene in the presence of boron trifluoride- based catalysts in the liquid phase.

[0151] The polymerisation according to the invention may be conducted at different reaction temperatures depending on the desired molar weight of the polyisobutene:

[0152] In a preferred embodiment of the present invention, when a polyisobutene with a number average molecular weight Mn of 350 to 10000, preferably 500 to 5000 is targeted, the reaction temperature in the reaction mixture is preferably from minus 5 to minus 25 °C, preferably from minus 10 to minus 20 °C. In particular, this homo- or copolymer is a highly reactive low molecular polyisobutene with a content of terminal vinylidene groups of at least 70 mol%, preferably at least 80 mol%, preferably at least 90 mol%.

[0153] Especially when a raffinate 1 stream is used as the isobutene source, the use of water as the sole initiator or as a further initiator has been found to be useful, in particular when polymerization is effected at temperatures of -20°C to +30°C, especially of 0°C to +20°C. At temperatures of -20°C to +30°C, especially of 0°C to +20°C, when a raffinate 1 stream is used as the isobutene source, it is, however, also possible to dispense with the use of an initiator.

[0154] In an alternative preferred embodiment of the present invention, when a number average molecular weight Mn of 10000 to 100000 is targeted, the reaction temperature in the reaction mixture is preferably from minus 10 to minus 30 °C.

[0155] As a rule, the average residence time in the reaction system without mixing, e.g. by circulation, stirring or backmixing, should be less than 2 hours, preferably less than 90 minutes and preferably less than 60 minutes.

[0156] Polymerization is usually carried out at a pressure of 700 mbar to 20 bar, especially at a pressure of 1 bar to 10 bar, especially at a pressure of 1 .2 bar to 7 bar. Overpressure is usually advantageous with the C4 hydrocarbon mixture used and with some inert diluents that may be used. In this case the polymerisation is under a pressure of 1.1 to 25 bar, preferably from 2 to 20, more preferably 10 to 20, and especially 15 to 20 bar.

[0157] Another object of the present invention is the polyisobutene obtainable preferably obtained by the process according to the present invention.

[0158] Highly reactive polyisobutene of low or medium molecular weight may preferably be used as starting material for subsequent chemical reactions, e.g. subsequent hydroformylation, thermal ene-reaction with maleic anhydride, or Friedel-Crafts alkylation of aromatic compounds.

[0159] According to the present application adding a tin halide as a second Lewis Acid to the aluminium halide as first Lewis Acid especially for medium molecular polyisobutene increases the content of vinylidene- and beta-, preferably alpha- and beta-double bonds (in sum) compared to using an aluminium halide only under comparable reaction conditions. In turn the content of tetra-substituted double bonds is decreased. Since tetra-substituted double bonds exhibit a higher reactivity in photo reactions, especially photo oxidations, the respective product exhibiting less tetra-substituted double bonds is less reactive on exposure to e.g. UV radiation.

[0160] While the use of aluminium chloride alone may provide a medium molecular weight polyisobutene with a content of tetra-substituted double bonds of 10 % or more, the use of a combination of a aluminium halide-containing first Lewis Acid and a tin halide-containing second Lewis Acid may decrease this content of tetra-substituted double bonds to less than 10 mol%, preferably to not more than 7.5 mol%.

[0161] Medium and high molecular weight polyisobutene not exhibiting a high reactivity is less susceptible to weathering and more stable against oxidation or thermal degradation. Therefore, compositions comprising such polyisobutenes are especially useful in sealants, adhesives, coatings or roofings.

[0162] The industrial processes for manufacturing highly reactive low molecular polyisobutene are usually optimised for increasing the content of terminal double bonds to sometimes more than 90%, however, for some applications a low molecular polyisobutene with less reactive double bonds e.g. less than 90%. It is possible to produce low molecular polyisobutene with less reactivity in the same plant, however, such a process requires adaptation of e.g. reaction temperature, the amount of catalyst, the amount of initiator, the donor : catalyst ratio, residence time in the reactor, etc. Therefore, after adaptation of various reaction parameters the reaction system requires some time to come into equilibrium again while the polymer produced in that time is usually off specification and needs to be discarded.

[0163] Therefore, another object of the present invention is a process for reducing the content of vinylidene-, preferably alpha-vinylidene double bonds in low molecular polyisobutene obtained by polymerisation of isobutene in the presence of a donor complex of an aluminium halide of the formula

[0164] AI(ORa)p(Rb)qXr, with at least one organic compound (II) as donor compound, wherein at least one second Lewis Acid selected from the group consisting of a tin dihalide and a tin tetrahalide, preferably selected from the group consisting of tin dichloride and tin tetrachloride, more preferably tin tetrachloride is metered into the reaction mixture together with the aluminium halide.

[0165] With this measure it is possible to immediately decrease the formation of vinylidene-, preferably alpha-vinylidene double bonds in low molecular polyisobutene compared to the reaction without the tin halide under otherwise unchanged or comparable reaction conditions.

[0166] This effect is observed only in the reaction of low molecular polyisobutene and apparently does not affect the formation of medium or high molecular polyisobutene.

[0167] When the polymerization in the process according to the invention is effected at or above the boiling temperature of the monomer or monomer mixture to be polymerized, it is preferably performed in pressure vessels, for example in autoclaves or in pressure reactors.

[0168] According to the invention the polymerization is carried out as a polymerization in bulk or in solution.

[0169] The polymerization in the process according to the invention is preferably performed in the presence of an inert diluent. The inert diluent used should be suitable for reducing the increase in the viscosity of the reaction solution which generally occurs during the polymerization reaction to such an extent that the removal of the heat of reaction which evolves can be ensured. Suitable diluents are those solvents or solvent mixtures which are inert toward the reagents used. Suitable diluents are, for example, aliphatic hydrocarbons such as n-butane, n-pentane, n-hexane, n-heptane, n-octane and isooctane, cycloaliphatic hydrocarbons such as cyclopentane and cyclohexane, aromatic hydrocarbons such as benzene, toluene and the xylenes, and halogenated hydrocarbons, especially halogenated aliphatic hydrocarbons, such as methyl chloride, dichloromethane and trichloromethane (chloroform), 1 ,1 -dichloroethane, 1 ,2-dichloro- ethane, trichloroethane and 1 -chlorobutane, and also halogenated aromatic hydrocarbons and alkylaromatics halogenated in the alkyl side chains, such as chlorobenzene, monofluoromethylbenzene, difluoromethylbenzene and trifluoromethylbenzene, and mixtures of the aforementioned diluents. The diluents used, or the constituents used in the solvent mixtures mentioned, are also the inert components of isobutenic C4 hydrocarbon streams. A non-halogenated solvent is preferred over the list of halogenated solvents.

[0170] The inventive polymerization may be performed in a halogenated hydrocarbon, especially in a halogenated aliphatic hydrocarbon, or in a mixture of halogenated hydrocarbons, especially of halogenated aliphatic hydrocarbons, or in a mixture of at least one halogenated hydrocarbon, especially a halogenated aliphatic hydrocarbon, and at least one aliphatic, cycloaliphatic or aromatic hydrocarbon as an inert diluent, for example a mixture of dichloromethane and n- hexane, typically in a volume ratio of 10:90 to 90:10, especially of 50:50 to 85:15. Prior to use, the diluents are preferably freed of impurities such as water, carboxylic acids or mineral acids, for example by adsorption on solid adsorbents such as activated carbon, molecular sieves or ion exchangers.

[0171] In a preferred embodiment, the inventive polymerization is performed in halogen-free aliphatic or especially halogen-free aromatic hydrocarbons, especially toluene. For this embodiment, water in combination with the organic hydroxyl compounds mentioned and / or the organic halogen compounds mentioned, or especially as the sole initiator, have been found to be particularly advantageous.

[0172] In another preferred embodiment, the inventive polymerization is performed in halogen-free aliphatic or cycloaliphatic, preferably aliphatic hydrocarbons, especially hexane, pentane, heptane, cyclohexane, cyclopentane, and mixtures comprising them.

[0173] The polymerization in the process according to the invention is preferably performed under substantially aprotic and especially under substantially anhydrous reaction conditions. Substantially aprotic and substantially anhydrous reaction conditions are understood to mean that, respectively, the content of protic impurities and the water content in the reaction mixture are less than 50 ppm and especially less than 5 ppm. In general, the feedstocks will therefore be dried before use by physical and / or chemical measures. More particularly, it has been found to be useful to admix the aliphatic or cycloaliphatic hydrocarbons used as solvents, after customary prepurifica- tion and predrying with an organometallic compound, for example an organolithium, organo- magnesium or organoaluminum compound, in an amount which is sufficient to substantially remove the water traces from the solvent. The solvent thus treated is then preferably condensed directly into the reaction vessel. It is also possible to proceed in a similar manner with the monomers to be polymerized, especially with isobutene or with the isobutenic mixtures. Drying with other customary desiccants such as molecular sieves or predried oxides such as aluminum oxide, silicon dioxide, calcium oxide or barium oxide is also suitable. The halogenated solvents for which drying with metals such as sodium or potassium or with metal alkyls is not an option are freed of water or water traces with desiccants suitable for that purpose, for example with calcium chloride, phosphorus pentoxide or molecular sieves. It is also possible in an analogous manner to dry those feedstocks for which treatment with metal alkyls is likewise not an option, for example vinylaromatic compounds. Even if some or all of the initiator used is water, residual moisture should preferably be very substantially or completely removed from solvents and monomers by drying prior to reaction, in order to be able to use the water initiator in a controlled, specified amount, as a result of which greater process control and reproducibility of the results are obtained.

[0174] The polymerization of the isobutene or of the isobutenic starting material generally proceeds spontaneously when the mixture of Lewis Acids-donor complex is contacted with the isobutene or the isobutenic monomer mixture at the desired reaction temperature. The procedure here may be to initially charge the monomers, optionally in the diluent, to bring it to reaction temperature and then to add the mixture of Lewis Acids-donor complex. The procedure may also be to initially charge the mixture of Lewis Acids-donor complex, optionally in the diluent, and then to add the monomers. In that case, the start of polymerization is considered to be that time at which all reactants are present in the reaction vessel.

[0175] To prepare isobutene copolymers, the procedure may be to initially charge the monomers, optionally in the diluent, and then to add the mixture of Lewis Acids-donor complex. The reaction temperature can be established before or after the addition of the mixture of Lewis Acids-donor complex. The procedure may also be first to initially charge only one of the monomers, optionally in the diluent, then to add the mixture of Lewis Acids-donor complex, and to add the further monomer(s) only after a certain time, for example when at least 60%, at least 80% or at least 90% of the monomer has been converted. Alternatively, the mixture of Lewis Acids-donor complex, can be initially charged, optionally in the diluent, then the monomers can be added simultaneously or successively, and then the desired reaction temperature can be established. In that case, the start of polymerization is considered to be that time at which the mixture of Lewis Acids-donor complex, and at least one of the monomers are present in the reaction vessel.

[0176] In addition to the batchwise procedure described here, the polymerization in the process according to the invention can also be configured as a continuous process. In this case, the feedstocks, i.e. the monomer(s) to be polymerized, optionally the diluent and optionally the mixture of Lewis Acids-donor complex, are supplied continuously to the polymerization reaction, and reaction product is withdrawn continuously, such that more or less steady-state polymerization conditions are established in the reactor. The monomer(s) to be polymerized can be supplied as such, diluted with a diluent or solvent, or as a monomer-containing hydrocarbon stream.

[0177] The mixture of Lewis Acid-donor complex, is generally present in dissolved, dispersed or suspended form in the polymerization medium. Supporting of the mixture of Lewis Acids-donor complex, on customary support materials is also possible. Suitable reactor types for the polymerization process of the present invention are typically stirred tank reactors, loop reactors and tubular reactors, but also fluidized bed reactors, stirred tank reactors with or without solvent, fluid bed reactors, continuous fixed bed reactors and batchwise fixed bed reactors (batch- wise mode).

[0178] In the process according to the invention, the mixture of Lewis Acid-donor complex is generally used in such an amount that the molar ratio of the metal (in sum) in the mixture of Lewis Acids- donor complex to isobutene in the case of homopolymerization of isobutene, or to the total amount of the polymerizable monomers used in the case of copolymerization of isobutene, is in the range from 1:5 to 1 :5000, preferably from 1:10 to 1:5000, especially 1:15 to 1 :1000, in particular 1 :20 to 1 :250.

[0179] In a preferred embodiment of the present invention the reaction conditions are chosen that the conversion of the monomers is at least 80%, preferably at least 85%, and more preferably at least 90%. It is an advantage of the present invention that the mixture of Lewis Acid-donor complexes according to the present invention exhibit a high selectivity for polymers with terminal ethylenic double bonds (a-double bonds) and other reactive double bonds, such as p-double bonds, preferably terminal ethylenic double bonds (a-double bonds) even at such high conversion. It is often observed that the selectivity especially to a-double bonds decreases once the conversion of the monomers exceeds the above-mentioned values. It can also be observed that the amount of reactive double bonds, especially a-double bonds formed in the course of the reaction decline at high conversions. It is an advantage of the complexes according to the present invention that the high selectivity is kept at high conversions resp. that the reactive double bonds formed deteriorate to a less extent than for other catalysts.

[0180] To stop the reaction, the reaction mixture is preferably deactivated, for example by adding a protic compound, especially by adding water, alcohols such as methanol, ethanol, n-propanol and isopropanol or mixtures thereof with water, or by adding an aqueous base, for example an aqueous solution of an alkali metal or alkaline earth metal hydroxide such as sodium hydroxide, potassium hydroxide, magnesium hydroxide or calcium hydroxide, an alkali metal or alkaline earth metal carbonate such as sodium, potassium, magnesium or calcium carbonate, or an alkali metal or alkaline earth metal hydrogencarbonate such as sodium, potassium, magnesium or calcium hydrogencarbonate.

[0181] The donor complex of the mixture of at least two Lewis Acids according to the present invention can be used in processes for the polymerisation of isobutene or isobutene-containing monomer mixtures to polyisobutene of different molecular weight depending on the reaction conditions, primarily the reaction temperature, the ratio of Lewis Acids to isobutene, and the reactivity of the Lewis Acids which can be controlled by nature and ratio of donors to the Lewis Acids.

[0182] In a preferred embodiment the process according to the invention serves to prepare high- reactivity isobutene homo- or copolymers with a content of terminal vinylidene double bonds (a- double bonds) and other reactive double bonds, such as p-double bonds per polyisobutene chain end of at least 60, preferably at least 70 and very preferably at least 75 mol%. More particularly, it also serves to prepare high-reactivity isobutene copolymers which are formed from isobutene and at least one vinylaromatic monomer, especially styrene, and have a content of terminal vinylidene double bonds (a-double bonds) and other reactive double bonds, such as - double bonds per polyisobutene chain end of at least 60, preferably at least 70 mol%, preferably of at least 75 mol%. To prepare such copolymers of isobutene and at least one vinylaromatic monomer, especially styrene, isobutene or an isobutenic hydrocarbon cut is copolymerized with the at least one vinylaromatic monomer in a weight ratio of isobutene to vinylaromatic of 5:95 to 95:5, especially of 30:70 to 70:30.

[0183] The high-reactivity isobutene homo- or copolymers prepared by the process according to the invention and specifically the isobutene homopolymers preferably have a polydispersity (PDI = Mw / Mn) of 1.05 to less than 3.5, preferably of 1.05 to less than 3.0, preferably of 1.05 to less than 2.5, preferably of 1.05 to 2.3, more preferably of 1.05 to 2.0 and especially of 1.1 to 1.85. Typical PDI values in the case of an optimal process regime are 1.2 to 1.7.

[0184] The high-reactivity isobutene homo- or copolymers prepared by the process according to the invention preferably possess a number-average molecular weight Mn(determined by gel permeation chromatography using tetrahydrofurane as eluent and polystyrene standards as described in the examples section) of preferably of 500 to 100 000, even more preferably of 500 to 25 000 and especially of 500 to 5000. Isobutene homopolymers even more preferably possess a number-average molecular weight Mnof 500 to 10 000 and especially of 500 to 5000, for example of about 1000 or of about 2300.

[0185] It is further possible to produce other polyisobutenes, preferably medium molecular polyisobutene, very preferably medium molecular polyisobutene which may furthermore be highly reactive. The present invention is especially suitable for the manufacturing of medium molecular polyisobutene, more preferably for producing highly reactive medium molecular polyisobutene, since the content of reactive double bonds, especially alpha-double bonds may be increased.

[0186] Polyisobutene serves as a valuable starting material for further derivatisation, such as ene reaction with maleic anhydride, epoxidation or hydroformylation which in turn serve as starting material for further reaction, e.g. reaction of polyisobutenyl succinic anhydride with amines, or in the case of hydroformylated polyisobutene subsequent hydrogenation or amination to polyisobutene amine. These products find use e.g. as fuel additives. Isobutene homopolymers are understood in the context of the present invention to mean those polymers which, based on the polymer, are formed from isobutene to an extent of at least 98 mol%, preferably to an extent of at least 99 mol%. Accordingly, isobutene copolymers are understood to mean those polymers which comprise more than 2 mol% of copo ymerized monomers other than isobutene, for example isoprene or linear butenes, preferably butadiene, 1- butene, cis-2-butene, and trans-2-butene.

[0187] Butyl rubbers also are copolymers of isobutene-containing monomer mixtures, however, polyisobutenes usually differ from butyl rubbers in terms of their content of isoprene in the polymer. Polyisobutene copolymers are understood to mean polymers comprising not more than 0.5 mol% isoprene, preferably not more than 0.45 mol%, even more preferably not more than 0.4, and especially not more than 0.35 mol% isoprene and not more than 10 mol%, more preferably not more 5 mol% linear butenes as copolymerized monomers, preferably butadiene, 1 -butene, cis-2-butene, and trans-2-butene.

[0188] Some of the isobutene polymers which have terminal vinylidene double bonds and also comprise incorporated initiator molecules and occur as the predominant proportion in the isobutene homopolymers prepared in accordance with the invention are novel compounds. The present invention therefore also provides isobutene polymers of the general formula III in which

[0189] R17, R18and R19are each independently hydrogen, Ci- to C2o-alkyl, Cs- to Cs-cycloalkyl, Ce- to C2o-aryl, C7- to C2o-alkylaryl or phenyl, where any aromatic ring may also bear one or more C1- to C4-alkyl- or Ci- to C4-alkoxy radicals or moieties of the general formula IV as substituents, where not more than one of the variables R17, R18or R19is hydrogen and at least one of the variables R17, R18or R19is phenyl which may also bear one or more Ci- to C4- alkyl- or Ci- to C4-alkoxy radicals or moieties of the general formula II as substituents, and n is a number from 9 to 4500, preferably 9 to 180, especially 9 to 100, in particular 12 to 50.

[0190] In a preferred embodiment, R17, R18and R19are each independently hydrogen, Ci- to C4-alkyl, especially methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec.-butyl or tert-butyl, or phenyl which may also bear one or two Ci- to C4-alkyl- or Ci- to C4-alkoxy radicals or moieties of the general formula II as substituents, where not more than one of the variables R17, R18and R19is hydrogen and at least one of the variables R17, R18and R19is phenyl which may also bear one or two Ci- to C4-alkyl or Ci- to C4-alkoxy radicals or moieties of the general formula II as substituents, and n is a number from 9 to 4500, preferably 9 to 180, especially 9 to 90, in particular 15 to 45.

[0191] The process according to the invention successfully polymerizes isobutene or isobutene- comprising monomer mixtures to polyisobutene, preferably medium molecular polyisobutene, more preferably highly reactive medium molecular polyisobutene under cationic conditions with satisfactory to high conversions of generally 20 to 100%, especially 35 to 90%, in short reaction times of generally 5 to 120 minutes, especially 30 to 120 minutes, to give high-reactivity isobutene homo- or copolymers with a content of a- and p-double bonds per polyisobutene chain end of at least 60, preferably at least 70 and very preferably at least 75 mol%, depending on the reaction conditions. It is an advantage of the process according to the present invention that a mixture of at least one organic compound (II), preferably at least one organic compound with at least one ether function and mixtures of at least one aluminium-containing Lewis Acid with at least one tin- containing Lewis Acid yield a product with a high content of a- and p-double bonds per polyisobutene chain end compared with the same reaction carried out in the presence of one Lewis Acid only under comparable reaction conditions, especially in the preparation of highly reactive medium molecular polyisobutene.

[0192] The examples which follow are intended to illustrate the present invention in detail without restricting it.

[0193] Examples

[0194] Instrumentation

[0195] Size exclusion chromatography (SEC) was performed on an Ultimate 3000 Thermo Scientific apparatus with Agilent PLgel 5pm MIXED-C (300x7.5 mm) and one precolumn (PL gel 5pm guard 50x7.5 mm) thermostated at 30 °C. The detection was achieved by differential refractometer (Rl) as well as diode array detector (UV). Tetrahydrofuran (THF) was eluted at a flow rate of 1 .0 mL / min. The calculation of molecular weight and polydispersity D was carried out using polystyrene standards (Polymer Labs, Germany).

[0196] 1H NMR (500 MHz) spectra were recorded in CDCI3 at 25 °C on a Bruker AC-500 spectrometer calibrated relative to the residual solvent resonance. UV-Vis absorption spectra were recorded using a SM2203 (Solar) spectrofluorimeter.

[0197] Throughout the text the PIB end groups content was determined by1H NMR spectroscopy (for a typical 1 H NMR spectrum see Figure 1). The signals of protons of exo-olefin end group (b, b’) appeared at 4.64 and 4.85 ppm, while encfo-olefin end group (d) at 5.15 ppm. The signals of protons of tri- (e) and tefra-substituted (g) olefinic end groups are appeared at 5.15 and 2.84 ppm, whereas the signals of protons of CH2 (I) and CH3 (k) groups belong to chlorine-terminated end group are located at 1.96 and 1.68 ppm, respectively. The small signal at 4.80 ppm correspond to protons of coupled PIB chains (m). The content of exo-olefin end groups was calculated according to the following equation: exo (%) = l[(b+b’) / 2] / l[k / 6+(b+b’+n) / 2+d+e+g] (Figure 1).

[0198] In the context of the present invention the term "exo" refers to terminal ethylenic double bonds, vinylidene groups or a - (alpha-) double bonds, as shown in the formula on page 1. These terms are used synonymously throughout the text.

[0199] The term "Total vinylidene" means the terminal ethylenic double bonds referred to as exo above and additionally double bonds located internally at the polymer backbone as shown in the following formula:

[0200] The terms "endo" and "trisubstituted" refer to p-double bonds, as shown in the formulae in Figure 1 in the second line. These terms are used synonymously throughout the text.

[0201] Furthermore "tetrasubstituted" structural elements can be found as shown in the formula in Figure 1 at the top right. Furthermore, a chlorinated polyisobutene (PIBCI) was found.

[0202] General Reaction Conditions

[0203] To 100 ml of isobutene and 100 ml solvent the specified amount of Lewis Acids-Donor-complex was given at a temperature of minus 10 °C.

[0204] The Lewis Acids-Donor-complex of AlCh, SnCL, and di butyl ether had been prepared as a solution in dichloromethane (DCM, concentration given in the tables) prior to addition to the isobu- tene / solvent-mixture. Di butyl ether was used in equimolar amounts based on AlCh. After the reaction time given in the tables the reaction was stopped by quenching with a 25wt% aqueous ammonia solution, volatile constituents were removed by distillation, and the resulting polymer was analysed with regard to content of double bond isomers via NMR and its molecular weight via size exclusion chromatography.

[0205] Example 1 - Reactivity of Medium Molecular Polyisobutene

[0206] Reaction was conducted in a dichloromethane / hexane 80 / 20 (v / v) mixture as solvent.

[0207] It can easily be seen that the presence of tin tetra chloride increases the amount of vinylidene- and beta-double bonds, thus, increasing the reactivity of the polyisobutene with regard to thermal reactions such as ene-reactions with maleic anhydride. In turn the amount of tetrasubstituted double bond decreases. Furthermore, the conversion of the monomer is increased.

[0208] Example 2 - Attenuation of Reactivity of Low Molecular Polyisobutene

[0209] Reaction was conducted in a dichloromethane / hexane 80 / 20 (v / v) mixture as solvent.

Claims

Claims1 . A bulk- or solution polymerisation process for preparing high-reactivity isobutene homo- or copolymers with a number-average molecular weight Mn(determined by gel permeation chromatography) of preferably of 500 to 100 000, which comprises polymerizing isobutene or an isobutene-comprising monomer mixture in the presence of a donor complex of at least two Lewis Acids effective as a polymerization catalyst, wherein the first Lewis Acid is an aluminium halide of the formulaAI(ORa)p(Rb)qXr, whereinRaand Rbindependently of another represent an organic residue of up to 20 carbon atoms, preferably Ci- to C2o-alkyl, Cs- to Cs-cycloalkyl radical, Cs- to C2o-aryl radical or Cy to C2o-aiylalkyl radical,X independently of another represents halide, p independently of another represents a rational number of at least 0 (zero) and less than 3, q independently of another represents a rational number of at least 0 (zero) and less than 3, and r independently of another represents a rational number of greater than 0 (zero) up to 3, with the proviso that the sum of (p + q + r) is always 3 and wherein the second Lewis Acid is selected from the group consisting of a tin dihalide and a tin tetrahalide, preferably selected from the group consisting of tin dichloride and tin tetrachloride, said complex comprising, as the donor, at least one organic compound (II) comprising at least one oxygen or nitrogen atom with at least one lone electron pair, preferably comprising at least one oxygen atom with at least one lone electron pair, very preferably selected from the group consisting of organic compounds with at least one ether function, organic compounds with at least one carboxylic ester function, organic compounds with at least one aldehyde function, organic compounds with at least one keto function, and organic compounds with at least one nitrogen containing heterocyclic ring.

2. The process according to Claim 1 , wherein the first Lewis Acid is selected from the group consisting of aluminum trihalide, alkylaluminum dihalide, dialkylaluminum monohalide, alkyloxyaluminum dihalide, di(alkyloxy)aluminum monohalide, alkyl alkoxy aluminium halides, and mixtures thereof.

3. The process according to Claim 1 or 2, wherein the second Lewis Acid is tin tetra chloride.

4. The process according to any one of the proceeding claims, wherein the molar ratio of first Lewis Acid : second Lewis Acid is from 20 : 1 to 1 : 20, preferably from 10 : 1 to 1 to 10, more preferably from 1 : 5 to 5 : 1 , even more preferably from 3 : 1 to 1 : 3, and especially from 2 : 1 to 1 : 2.

5. The process according to any one of the proceeding claims, wherein the donor compound is at least one organic compound with at least one ether function.

6. The process according to Claim 5, wherein the donor is at least one dihydrocarbyl ether the general formula R -O-R9in which the variables R8and R9are each independently Ci- to C2o-alkyl radicals, preferably Ci- to Cs alkyl radicals especially Ci- to C4 alkyl radicals, Ci- to C2o-haloalkyl radicals, preferably Ci- to Cs haloalkyl radicals especially Ci- to C4 haloalkyl radicals, Cs- to Cs-cycloalkyl radicals, preferably Cs- to Cs-cycloalkyl radicals, Cs- to C2o-aryl radicals, especially Cs- to C12 aryl radicals, Cs- to C2o-haloaryl radicals, especially Cs- to C12 haloaryl radicals, or C7- to C2o-arylalkyl radicals, especially C7- to C12- arylalkyl radicals.

7. The process according to any one of the proceeding claims, wherein the isobutene- comprising monomer mixture is a raw material of C4 compounds selected from the group consisting of(a) a C4 compound material in which an isobutene amount is adjusted to 50 to 75% byweight, obtained by adding high purity isobutene having the isobutene amount of 90 to 100% by weight to C4 raffinate-1 which is a remainder after extracting 1 ,3-butadiene from a C4 compound derived during a naphtha degrading process;(b) a C4 compound material in which an isobutene amount is adjusted to 50 to 75% by weight, obtained by adding high amount isobutene mixture having isobutene amount of 80 to 97% by weight, which is generated in an olefin conversion unit (OCU) process that produces propylene by the metathesis of ethylene and 2-butene, to C4 raffinate-1 which is a remainder after extracting 1 ,3-butadiene from a C4 compound derived during a naphtha degrading process;(c) a C4 compound material in which an isobutene amount is adjusted to 50 to 75% by weight, obtained by adding high purity isobutene having the isobutene amount of 90 to 100% by weight to butane-butene oil (B-B oil) derived from crude oil refining process;(d) a C4 compound material in which an isobutene amount is adjusted to 50 to 75% by weight, obtained by adding high amount isobutene mixture having the isobutene amount of 80 to 97% by weight, which is generated in an olefin conversion unit (OCU) process that produces propylene by the metathesis of ethylene and 2-butene, to butane-butene oil (B-B oil) derived from crude oil refining process;(e) a C4 compound material in which an isobutene amount is adjusted to 50 to 75% by weight, obtained by adding a dilute solvent to high purity isobutene having an isobutene amount of 90 to 100% by weight;(f) a C4 compound material in which an isobutene amount is adjusted to 50 to 75% by weight, obtained by adding a dilute solvent to high amount isobutene mixture having the isobutene amount of 80 to 97% by weight, which is generated in an olefin conversion unit (OCU) process that produces propylene by the metathesis of ethylene and 2-butene;(g) a C4 compound material in which an isobutene amount is adjusted to 50 to 75% by weight, obtained by adding high purity isobutene having the isobutene amount of 90 to 100% by weight to a mixture generated in dehydrogenation reaction that converts isobutane to isobutene; and(h) a C4 compound material in which an isobutene amount is adjusted to 50 to 75% by weight, obtained by adding high amount isobutene mixture having the isobutene amount of 80 to 97% by weight, which is generated in an olefin conversion unit (OCU) process that produces propylene by the metathesis of ethylene and 2-butene to a mixture generated in dehydrogenation reaction that converts isobutane to isobutene.

8. The process according to any one of the Claims 1 to 7, wherein the isobutene-comprising monomer mixture is a C4 cut from isobutane dehydrogenation, C4 cut from steam crackers and from FCC crackers (fluid catalyzed cracking), provided that they have been substantially freed of 1 ,3-butadiene present therein.

9. The process according to Claim 7 or 8, wherein the content of butadienes, especially 1 ,3- butadiene, is further reduced by selective hydrogenation.

10. The process according to any one of the Claims 1 to 7, wherein the isobutene used in the isobutene-comprising monomer mixture has a biobased fraction, measured as a14C:12C ratio ASTM-D6866, of more than 0%, preferably at least 1 %, particularly preferably at least 5%, even more preferably at least 10%, especially at least 20%, and specifically at least 25%.11 . The process according to any one of the proceeding claims, wherein the reaction is conducted at temperature in the reaction mixture of from minus 5 to minus 25 °C, preferably from minus 10 to minus 20 °C to yield a polyisobutene with a number average molecular weight Mn of 350 to 10000, preferably 500 to 5000.

12. The process according to Claim 11 , wherein the polyisobutene has a content of terminal vinylidene groups of at least 70 mol%, preferably at least 80 mol%, preferably at least 90 mol%.

13. The process according to any one of Claims 1 to 10, wherein the reaction is conducted at a temperature in the reaction mixture of from minus 10 to minus 30 °C to yield a number average molecular weight Mn of 10000 to 100000.

14. The process according to Claim 13, wherein the polyisobutene has a content of terminal double bonds of from 30 to 80 mol%, preferably from 10 to 60 mol%, more preferably from 15 to 55 mol%, even more preferably from 20 to 50 mol%, and especially from 25 to 50 mol%.

15. The process according to Claim 13, wherein the polyisobutene has a content of tetrasubstituted double bonds of less than 10 mol%, preferably not more than 7.5 mol%.

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