EP2906604A1 - Method for producing polyisobutenes - Google Patents

Abstract

A method for producing bifunctional polyisobutenes, according to which method isobutene or a monomer mixture containing isobutene is polymerized in the presence of a Lewis acid and a compound of formula (I), where X represents an acyl radical or the radical of an organic or inorganic acid group, R₁ to R₄ are identical or different and represent hydrogen or a hydrocarbyl.

Description

 The present invention relates to a process for the preparation of bifunctional polyisobutenes and to bifunctional polyisobutenes obtainable by the process and to certain functionalization products thereof.

Homo- and copolymers of isobutene find use in a variety of ways, for example for the production of fuel and lubricant additives, as elastomers, as adhesives or adhesive raw materials or as a basic component of sealing and sealing compounds.

The production of polyisobutenes by living cationic polymerization of isobutene is known. The initiator system used usually comprises a Lewis acid and an organic compound which forms a carbocation or a cationogenic complex with the Lewis acid.

For further processing, for example, to sealants and sealants or adhesive (raw) materials, particularly suitable polyisobutenes are telechelic, i. they have two or more reactive end groups. These end groups are mainly carbon-carbon double bonds that can be further functionalized or groups functionalized with a terminating agent. Thus, EP-A 722 957 describes the preparation of telechelic isobutene polymers using an at least difunctional initiator such as dicumyl chloride. A disadvantage of the known processes is that the described aromatic initiators can react to indanyl or diindane groups, which impairs the targeted synthesis of defined telechelic polyisobutenes.

German Offenlegungsschrift 100 61 727 describes the preparation of isobutene polymers with olefinically unsaturated end groups. For the production of isobutene polymers having two olefinically unsaturated end groups, bifunctional starters are used. The reactivity of the resulting end groups leaves something to be desired. German Offenlegungsschrift 102 32 157 describes a cationic isobutene polymerization using 3-chlorocyclopentene as initiator. WO 2004/1 13402 describes the preparation of bifunctional polyisobutenes in which isobutene is polymerized in the presence of a Lewis acid and an isobutene oligomer containing an olefinic double bond as initiator.

It was an object of the present invention to provide a process with which bifunctional and, above all, -OH-functionalized polyisobutenes can be obtained with a simple initiator system. Polyisobutenes terminated with an -OH function are valuable intermediates for the preparation of macromers (acrylates, epoxides, allyl ethers) or polymers (polyurethanes). It is the merit of Kennedy and Ivan to be the first to make a synthesis route to such compounds Boran Addition (Ivan, Kennedy, Chang;

J.Polym.Chem. Chem. Ed. 18, 3177 (1980)). Without doubting the reproducibility of the information in this publication in the industrial chemical laboratory, it should be pointed out here that the use of boranes for the production of technical polymers is too costly. In that regard, it has been consistent to make efforts to incorporate a -OH functionality directly into the polyisobutene chain via a suitable initiator and living cationic polymerization. A direct synthesis was first elaborated by Storey some 25 years later (Breland, Murphy, Storey, Polym 47, 1852 (2006)). The initiator here is 3,3,5-trimethyl-5-chloro-hexyl acetate, which is prepared via borane addition and Grignard synthesis.

However, the night part of expensive starting materials and technically complex processes are also liable for this comprehensible route. In that regard, so far the lesson was that for the preparation of these aliphatic -OH-functionalized polyisobutenes, the use of expensive and safety-consuming boranes is necessary.

It was therefore surprising that, starting from technical 2,2,4-trimethylpentanediol- (1, 3) using industrially customary processes and substances, the following described initiators for living polymerization can be prepared, which solve the abovementioned object.

The object is achieved by a process for the preparation of bifunctional polyisobutenes in which isobutene or an isobutene-containing monomer mixture in the presence of a Lewis acid and a compound of formula I.

wherein

n is the number 1, 2, 3 or 4,

X represents an acyl radical of the formula R 5 CO- or the radical of an organic or inorganic acid group which, with its central atom Z, which is selected from S, P, N and B and carries at least one doubly bonded oxygen atom, to the oxygen atom of the compound (I) is covalently bonded and whose possibly existing hydroxyl functions are present in esterified form, R 1 to R _{4 are} identical or different and represent hydrogen, an aliphatic (alkyl), cycloaliphatic (cycloalkyl) or aromatic hydrocarbon radical (aryl) having 1 to 20 carbon atoms, and

R _{5 has} the same meaning as R 1 to R ₄ and additionally in the case of n = 2 to

 4 (n-1) site (s) may be further substituted with one or more other acyl moieties, polymerized.

Accordingly, the invention relates to a process for the preparation of bifunctional polymers, in which reacting isobutene or an isobutene-containing monomer mixture in the presence of a Lewis acid with a compound of formula I defined herein. The compounds I are also referred to below as initiators or initiator compounds I.

Isobutene polymers which contain an alcohol or an alcohol derivative (group X) at one terminus (so-called chain start) and a chlorine atom at the other terminus (so-called distal chain end) are obtainable in particular by the process according to the invention. Depending on the work-up conditions, it is also possible to obtain isobutene polymers which contain an olefinic double bond instead of the chlorine atom. The double bond can then in a conventional manner in another functionality, eg. For example, OH, SH, silane, siloxane, hydroxyphenyl, succinyl ester, succinimide, oxirane, Carboxl, etc., to be converted. If one or more of the radicals R 1, R ₂ , R ₃ , R ₄ and R 5 is alkyl, then it is a saturated, linear or branched hydrocarbon radical which typically has 1 to 20, often 1 to 10 and in particular 1 to 4 carbon atoms and the for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, 2-pentyl, 3-pentyl, 2-methylbutyl, 3-methylbutyl, 3-methylbut 2-yl, 2-methylbut-2-yl, 2,2-dimethylpropyl, n -hexyl, 2-hexyl, 3-hexyl, 2-methylpentyl, 2-methylpent-3-yl, 2-methylpent-2-yl , 2-methylpent-4-yl, 3

Methylpent-2-yl, 3-methylpent-3-yl, 3-methylpentyl, 2,2-dimethylbutyl, 2,2-dimethylbut-3-yl, 2,3-dimethyl-but-2-yl, 2,3- Dimethylbutyl, n-heptyl, 2-methylhexyl, 2-methylhex-2-yl, 2-methyl-hex-3-yl, 2-methylhex-5-yl, 3-methylhex-2-yl, 3-methylhexyl, 3 Methylhex-3-yl, 3-methylhex-4-yl, 2-methylhex-4-yl, 2,2-dimethylpentyl, 2,2-dimethylpent-3-yl, 2,2-dimethylpent-4-yl, 2, 3-dimethylpent-2-yl, 2,3-dimethylpent-3-yl, 2,3-dimethylpent-4-yl, 2,3-dimethylpent-5-yl, 2,4-dimethylpentyl, 2,4-dimethylpentane 2-yl, 2,4-dimethylpent-3-yl, 2,4-dimethylpent-4-yl, 2,4-dimethylpent-5-yl, 3,3-dimethylpentyl, 3,3-dimethylpent-2-yl, 3-ethylpentyl, 3-ethylpent-2-yl, 3-ethylpent-3-yl, 2,2,3-trimethylbutyl, 2,2,3-trimethylbut-3-yl, 2,2,3-trimethylbut-4 yl, n -octyl, 2-methylheptyl, 2-methylhept-2-yl, 2-methylhept-3-yl, 2-methylhept-4-yl, 2-methylhept-5-yl, 2-methylhept-6-yl, 2-methylhept-7-yl, 3-methylheptyl, 3-methylhept-2-yl, 3-methylhept-3-yl, 3-methylhept-4-yl, 3-methylhept-5-yl, 3-methylhept-6-one yl, 3-m ethylhept-7-yl, 4-methylheptyl, 4-methylhept-2-yl, 4-methylhept-3-yl, 4-methylhept-4-yl, 2,2-dimethylhexyl, 2,2-dimethylhex-3-yl, 2,2-dimethylhex-4-yl, 2,2-dimethylhex-5-yl, 2,2-dimethylhex-6-yl, 2,3-dimethylhexyl, 2,3-dimethylhex-3-yl, 2,3- Dimethylhex-4-yl, 2,3-dimethylhex-5-yl, 2,3-dimethylhex-6-yl, 2,4-dimethylhexyl, 2,4-dimethylhex-3-yl, 2,4-dimethylhex-4 yl, 2,4-dimethylhex-5-yl, 2,4-dimethylhex-6-yl, 2,5-dimethylhexyl, 2,5-dimethylhex-3-yl, 2,5-dimethylhex-4-yl, 2, 5-dimethylhex-5-yl, 2,5-dimethylhex-6-yl, 3,3-dimethylhexyl, 3,3-dimethylhex-2-yl, 3,3-dimethylhex-4-yl, 3,3-dimethylhexene 5-yl, 3,3-dimethylhex-6-yl, 3,4-dimethylhexyl, 3,4-dimethylhex-2-yl, 3,4-dimethylhex-4-yl, 3,4-dimethylhex-3-yl, 2-ethylhexyl, 3-ethylhexyl, 3-ethylhex-2-yl, 3-ethylhex-3-yl, 3-ethylhex-4-yl, 3-ethylhex-5-yl, 3-ethyl-hex-6-yl, 2,2,3-trimethylpentyl, 2,2,3-trimethylpent-3-yl, 2,2,3-trimethylpent-4-yl, 2,2,3-trimethylpent-5-yl, 2,2,4- Trimethylpentyl, 2,2,4-trimethylpent-3-yl, 2,2,4-trimethylpent-4-yl, 2,2,4-trimethylpent-5-yl, 2,3,3-trimethylpentyl, 2,3, 3-trimethylpent-2-yl, 2,3,3-trimethylpent-4-yl, 2,3,3-trimethylpentane 5-yl, 2,3,4-trimethylpentyl, 2,3,4-trimethylpent-3-yl, 2,3,4-trimethylpent-2-yl, 3-ethyl-2-methylpentyl, 3-ethyl-2- methylpent-2-yl, 3-ethyl-2-methylpent-3-yl, 3-ethyl-2-methylpent-4-yl, 3-ethyl-2-methylpent-5-yl, 3-ethyl-3-methylpentyl, 3-ethyl-3-methylpent-2-yl, 2,2,3,3-tetramethylbutyl, n-nonyl, 2-methylnonyl, n-decyl, 2-propylheptyl, 3-propylheptyl and the like. Methyl is a preferred embodiment.

If one or more of the radicals Ri, R2, R3, R are ₄ and R5 is cycloalkyl, it is a saturated, branched or unbranched cyclic hydrocarbon radical which has typically 3 to 20, often 3 to 10 and especially 5 or 6 carbon atoms and for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, bicyclo [2.2.1] hept-1-yl, bicyclo [2.2.1] hept-2-yl, bicyclo [2.2.1] hept- 7-yl, bicyclo [2.2.2] octan-1-yl, bicyclo [2.2.2] octan-2-yl, 1-adamantyl or 2-adamantyl. Cyclohexyl is a preferred embodiment.

When one or more of R 1, R ₂ , R ₃ , R ₄ and R 5 is aryl, it is an aromatic, optionally substituted hydrocarbon radical; Aryl is an aromatic hydrocarbon radical such as phenyl, 1-naphthyl or 2-naphthyl. Phenyl is a preferred embodiment.

In a further embodiment, the radicals from the individual features are combined, so can be composed of alkyl, cycloalkyl and aryl radicals combinations such as benzyl, 4-methylcyclohexyl or ethylphenyl. The radicals R 1 to R 5 can also carry a small amount of heteroatoms such as halogen atoms, for example chlorine or fluorine, or inert functional groups such as cyano groups or ester groups, without losing their substantial hydrocarbon character.

In one embodiment, n is 1 and the acyl group X is an Rs -CO-group, wherein R5 is a hydrocarbon radical such as the radicals Ri, R2, R3 and R ₄ are defined. It is also possible that the radicals are further substituted by halogen, for example CI-C2H ₄ -CO- or CF 3 -CO-. In another embodiment, n is 2, 3 or 4, and the acyl group X is a group R-CO-, wherein R5 is here a radical such as the radicals R1, R2, R3 and R ₄ are defined and (n- 1) - site (s) is further substituted with one or more acyl groups, for example, then there is a phthalyl, terphthalyl, gallyl, malonyl or Succinylrest before.

In a further embodiment, X is the radical of an organic or inorganic acid group with the central atom Z, for example at n = 1 for CH 3-SO 2, CH 3 -O-SO 2 or (CH 3 -0) 2 PO- and at n = 2, 3 or 4 for the groupings -SO2-, = PO- or = B-. Insofar as the central atom Z is selected from the elements S, P or N, it carries at least one doubly bonded oxygen atom. When Z = B, three singly bound oxygen atoms can also be attached to the central atom Z, for example in the case of boric ester groups such as (CH ₃ -O) ₂ B-.

Very particularly preferred are compounds of formula I in which R1, R2, R3 and _R4 are the same and stand for methyl.

The compounds of the formula (I) can be prepared by ring-opening of tetrahydrofurans of the formula II with acid derivatives of the formula III in a manner known per se, as described in Reppe et al. Ann. Chem. 596, 1 10 described.

 (II) (IN) (I)

In this case, X, R 1, R _2, R ₃ and R _{4 have} the meanings already mentioned.

The tetrahydrofurans (II) can be prepared by rearrangement and cyclization from 1, 3-diols of formula IV.

(iv)

R 1, R _2, R ₃ and R _{4 have} the already mentioned meanings.

The reaction of (IV) to (II) and further the reaction with (III) to (I) can be carried out continuously and batchwise. In particular, it is suitable for producing the initiator (I) in a continuous and / or batchwise manner. In discontinuous rather driving style this means batch sizes over 10 kg, better> 100 kg, even better> 1000 kg or> 5000 kg. In continuous mode, this means production volumes over 100 kg / day, better> 1000 kg / day, even more optimal> 10 t / day or> 100 t / day. Compound (IV) can be used for the abovementioned synthesis of (II) dissolved, suspended, molten or gaseous. Suitable solvents in this case are in principle all solvents which are inert under reaction conditions. Examples are hydrocarbons such as toluene, xylene, solvent naphtha, branched and linear aliphatics, alcohols or water. The reaction of (IV) to (II) and further the reaction with (III) to (I) can be accelerated by acids. Typically, the acids are used in an amount of from 0.1 to 10% by weight, in particular from 0.2 to 5% by weight, based on the compounds of the formula II. Preferred acids here are Bronsted acids, for example organic carboxylic acids such. As trifluoroacetic acid, oxalic acid or lactic acid and organic sulfonic acids such as methanesulfonic acid, trifluoromethanesulfonic acid or p-toluenesulfonic acid. Also suitable are inorganic Brönstedt acids such as HCl, H3PO4, H2SO4 or HCIO4. As the Lewis acid, for example, BF3, BC, SnCU, TiCU, or AICI3 can be used. The use of complexed or dissolved in ionic liquids Lewis acids is also possible. By combining with bases such as NaOH defined acidity can be adjusted. Furthermore, it is possible to use solids with an acid surface, for example silica, whose surface can be further activated with one of the acids mentioned.

The reaction of (IV) to (II) can be carried out in a wide temperature range from about 60 ° C to about 500 ° C. In the case of processes with a long residence time, such as batch processes, especially temperatures in the range from 100 ° C. to 300 ° C., preferably 150 ° C. to 250 ° C., are selected, while for processes with a short residence time, such as continuous processes, especially temperatures ranging from 200 ° C to 400 ° C. The reaction times are in the range of a few seconds (for example 1, 2, 5, 10, 20, 100 or 200 seconds), a few minutes (for example 1, 2, 5, 10, 20, 30 or 40 minutes) up to Hours (for example, about 1, about 2, about 3 or about 5 hours).

As the Lewis acid for initiating the polymerization according to the process of the present invention as defined in claim 1, covalent metal halides and semi-metal halides having an electron pair gap are contemplated. Such compounds are known to the person skilled in the art, for example from JP Kennedy et al. in US 4,946,889, US 4,327,201, US 5,169,914, EP-A 206,756, EP-A 265 053 and comprising in the monograph by JP Kennedy and B. Ivan, Designed Polymers by Carbocationic Macromolecular Engineering, Oxford University Press, New York, 1991 , The Lewis acids are usually selected from halogen compounds of titanium, tin, aluminum, vanadium or iron and the halides of boron. The chlorides are preferred, and in the case of aluminum also the monoalkylaluminum dichlorides and the dialkylaluminum chlorides. Preferred Lewis acids are titanium tetrachloride, boron trichloride, boron trifluoride, tin tetrachloride, aluminum trichloride, Vanadium pentachloride, iron trichloride, alkylaluminum dichlorides and dialkylaluminum chlorides. Particularly preferred Lewis acids are titanium tetrachloride, boron trichloride and boron trifluoride and in particular titanium tetrachloride. It has proven useful to carry out the polymerization according to the inventive method in the presence of an electron donor. Suitable electron donors are aprotic organic compounds which have a free electron pair located on a nitrogen, oxygen or sulfur atom. Preferred donor compounds are selected from pyridines such as pyridine itself, 2,6-dimethyl-pyridine, and sterically hindered pyridines such as 2,6-diisopropylpyridine and 2,6-di-tert-butylpyridine; Amides, especially N, N-

Dialkylamides of aliphatic or aromatic carboxylic acids such as N, N-dimethylacetamide; Lactams, in particular N-alkyl lactams such as N-methylpyrrolidone; Ethers, e.g. Dialkyl ethers such as diethyl ether and diisopropyl ether, cyclic ethers such as tetrahydrofuran; Amines, in particular trialkylamines such as triethylamine; Esters, in particular C 1 -C 4 -alkyl esters of aliphatic C 1 -C 6 -carboxylic acids, such as ethyl acetate; Thioethers, in particular dialkylthioethers or alkylaryl thioethers, such as methylphenylsulfide; Sulfoxides, in particular dialkyl sulfoxides, such as dimethyl sulfoxide; Nitriles, especially alkyl nitriles such as acetone itril and propionitrile; Phosphines, in particular trialkylphosphines or triarylphosphines, such as trimethyl-phosphine, triethylphosphine, tri-n-butylphosphine and triphenylphosphine and non-polymerizable aprotic silicon-organic compounds which have at least one oxygen-bonded organic radical.

Among the aforementioned donors, preference is given to pyridine and sterically hindered pyridine derivatives and in particular organosilicon compounds.

Preferred organosilicon compounds of this type are those of the general formula VI:

R ^a n Si (OR ^b ) ₄ -r (VI) where r is 1, 2 or 3,

R ^{a may be the} same or different and independently of one another C 1 -C 20 -alkyl, C ₃ -C 7 -cycloalkyl, aryl or aryl-C 1 -C ₄ -alkyl, where the last three radicals mentioned also contain one or more C 1 -C 10 -alkyl groups as substituents can have, and

R ^{b may be the} same or different and are C 1 -C 20 -alkyl or, in the event that r is 1 or 2, two R ^b together may be alkylene. In the formula VI, r is preferably 1 or 2. R ^a is preferably a C 1 -C 5.

Alkyl group, and in particular a branched or bonded via a secondary carbon atom alkyl group, such as isopropyl, isobutyl, sec-butyl, or a 5-, 6- or 7-membered Cycloalkylgrup- pe, or an aryl group, especially phenyl. The variable R ^b is preferably a C 1 -C ₄ -alkyl group or a phenyl, tolyl or benzyl radical.

Examples of such preferred compounds are dimethoxydiisopropylsilane, dimethoxyisobutylisopropylsilane, dimethoxydiisobutylsilane, dimethoxydicyclopentylsilane, dimethoxyisobutyl-2-butylsilane, diethoxyisobutylisopropylsilane, triethoxytoluylsilane, triethoxybenzylsilane and triethoxyphenylsilane.

In the context of the present invention, C 1 -C ₄ -alkyl is a branched or linear alkyl radical, such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl or tert-butyl. In addition, C 1 -C 6 -alkyl is, in particular, pentyl, hexyl, hepyl, octyl and their positional isomers. In addition, C 1 -C 20 -alkyl is, in particular, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl and their positional isomers.

C3-C7-Cycloalkyl is, for example, cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl.

Aryl is in particular phenyl, naphthyl or tolyl.

Aryl-C 1 -C ₄ -alkyl is especially benzyl or 2-phenylethyl.

Alkylene is, for example, C 2 -C 8 -alkylene, such as 1, 2-ethylene, 1, 2 and 1, 3-propylene, 1, 4-butylene and 1, 5-pentylene.

The Lewis acid is used in an amount sufficient to form the initiator complex of Lewis acid and initiator. The molar ratio of Lewis acid to initiator compound (I) is generally 10: 1 to 1:10, more preferably 1: 1 to 1: 4, and especially 1: 1 to 1: 2.5. The Lewis acid and the electron donor are preferably used in a molar ratio of from 20: 1 to 1:20, more preferably from 5: 1 to 1: 5 and especially from 2: 1 to 1: 2.

The concentration of Lewis acid in the reaction mixture is usually in the range of 0.1 to 200 g / L, and more preferably in the range of I to 50 g / L.

Suitable isobutene starting materials for the process according to the invention are both isobutene itself and also isobutene-containing C ₄ hydrocarbon streams, for example C ₄ raffinates, C ₄ cuts from isobutene dehydrogenation, C ₄ cuts from steam crackers, FCC crackers (FCC: Fluid Catalyzed Cracking), provided they are largely exempt from 1, 3-butadiene contained therein. C ₄ hydrocarbon streams suitable according to the invention generally contain less than 500 ppm, preferably less than 200 ppm of butadiene. When using C ₄ cuts as Feedstock, the hydrocarbons other than isobutene take on the role of an inert solvent.

It is also possible to react monomer mixtures of isobutene with olefinically unsaturated monomers which are copolymerizable with isobutene under cationic polymerization conditions. The process according to the invention is also suitable for the block copolymerization of isobutene with ethylenically unsaturated comonomers polymerizable under cationic polymerization conditions. If monomer mixtures of isobutene are to be copolymerized with suitable comonomers, the monomer mixture preferably contains more than 80% by weight, in particular more than 90% by weight, and more preferably more than 95% by weight of isobutene, and less as 20% by weight, preferably less than 10% by weight, and in particular less than 5% by weight, comonomers.

As copolymerizable monomers are vinyl aromatics such as styrene and α-methyl-styrene, Ci- C4-alkylstyrenes such as 2-, 3- and 4-methylstyrene, and 4-tert-butylstyrene, isoolefins having 5 to 10 carbon atoms such as 2-methylbutene 1, 2-methylpentene-1, 2-methylhexene-1, 2-ethyl-pentene-1, 2-ethylhexene-1 and 2-propylheptene-1. Other suitable comonomers are olefins which have a silyl group, such as 1-trimethoxysilyl-ethene, 1- (trimethoxysilyl) propene, 1- (trimethoxysilyl) -2-methyl-propene-2, 1 - [tri (methoxyethoxy) silyl] ethene , 1 - [tri (methoxyethoxy) silyl] propene, and 1 - [tri (methoxyethoxy) silyl] -2-methylpropene-2.

For the preparation of block copolymers, the distal chain end, i. the end of the resulting isobutene polymer away from the chain beginning, which is derived from the initiator, with comonomers, such as those listed above, e.g. Vinyl aromatics are implemented. So you can, for example first homopolymerize isobutene and then add the comonomer. The newly formed comonomer-derived reactive chain end is either deactivated or terminated according to one of the embodiments described below to form a functional end group or re-reacted with isobutene to form higher block copolymers.

The polymerization is usually carried out in a solvent. Suitable solvents are all low molecular weight, organic compounds or mixtures thereof which have a suitable dielectric constant and no abstractable protons and which are liquid under the polymerization conditions. Preferred solvents are hydrocarbons, for example acyclic hydrocarbons having 2 to 8 and preferably 3 to 8 carbon atoms, such as ethane, iso- and n-propane, n-butane and its isomers, n-pentane and its isomers, n-hexane and its isomers , n-heptane and its isomers, and n-octane and its isomers, cyclic alkanes having 5 to 8 carbon atoms such as cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, cycloheptane, acyclic alkenes preferably having 2 to 8 carbon atoms such as ethene, iso and n-propene, n-butene, n-pentene, n-hexene and n-heptene, cyclic olefins such as cyclopentene, cyclohexene and cycloheptene, aromatic hydrocarbons such as toluene, xylene, ethylbenzene, and halogenated hydrocarbons such as halogenated aliphatic hydrocarbons, for example, such as chloromethane, dichloromethane, trichloromethane, chloroethane, 1, 2-dichloroethane and 1, 1, 1-trichloroethane and 1-chlorobutane, and halogenated aromatic hydrocarbons such as chlorobenzene and fluorobenzene. The halogenated hydrocarbons used as solvents do not include compounds in which halogen atoms are attached to secondary or tertiary carbon atoms.

Preferred solvents are aromatic hydrocarbons, of which toluene is particularly preferred. Also preferred are solvent mixtures comprising at least one halogenated hydrocarbon and at least one aliphatic or aromatic hydrocarbon. In particular, the solvent mixture comprises hexane and chloromethane and / or dichloromethane. The volume ratio of hydrocarbon to halogenated hydrocarbon is preferably in the range from 1:10 to 10: 1, particularly preferably in the range from 4: 1 to 1: 4 and in particular in the range from 2: 1 to 1: 2. Also preferred are chlorinated hydrocarbons whose polarity allows them to be polymerized in a uniform solvent. Examples are the propyl, butyl and pentyl chlorides such as 1-chlorobutane and 2-chloropropane.

In general, the process according to the invention will be carried out at temperatures below 0 ° C., e.g. in the range of 0 to -140 ° C, preferably in the range of -30 to -120 ° C, and more preferably in the range of -40 to -1 10 ° C perform. The reaction pressure is of secondary importance.

The dissipation of the heat of reaction takes place in a customary manner, for example by wall cooling and / or by utilizing boiling-off cooling.

For termination of the reaction, the living distal chain ends are deactivated, for example by adding a protic compound, in particular by adding water, alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol or tert-butanol, or their mixtures with water.

The process according to the invention gives telechelic (bifunctional) polyisobutenes, which on the one hand have an alcohol function at the beginning of the chain which is introduced by the radical XO- of the initiator compound of the formula I, and on the other hand a terminus (distal end of the chain, ie Chain end opposite chain end) containing a functional group. This functional group is preferably a moiety of the formula -CH2-C (CHs) 2-halo. This is usually formed during reaction quenching with a protic deactivator. The halogen atom in this terminal group is usually derived from the Lewis acid used for the polymerization. Preferably, halogen is chlorine. These telechelic polyisobutenes are valuable intermediates for the preparation of other bifunctional polyisobutene derivatives. Examples of derivatization include the alkylation of phenols and the elimination of hydrogen halide from the -CH 2 -C (CH 2) 2 -halo group to form an ethylenically unsaturated terminal group.

The conversion of the terminal moiety -CH2-C (CHs) 2-halogen into an ethylenically unsaturated radical (methylidene double bond) can be carried out, for example thermally, for. B. by heating to a temperature of 70 to 200 ° C, or by treatment with a base. Suitable bases are e.g. Alkali metal alkoxides such as sodium methoxide, sodium ethoxide and potassium tert-butoxide, basic alumina, alkali metal hydroxides such as sodium hydroxide, and tertiary amines such as pyridine or tri-butylamine, cf. Kennedy et al., Polymer Bulletin 1985, 13, 435-439. Preferably, sodium ethoxide is used.

However, it is also possible to obtain ethylenically terminated polyisobutenes at the chain end without first introducing the grouping -CH 2 -C (CH 2) 2 -halo. For this purpose, the living chain end of the isobutene polymer is suitably reacted with a terminating reagent which adds an ethylenically unsaturated group to the end of the chain.

Suitable termination reagents are, for example, trialkylallylsilane compounds, e.g. Trimethyallylsilane. The living chain end is terminated by adding a trialkylallylsilane compound. The use of allyl silanes leads to the termination of the polymerization with the introduction of an allyl radical at the polymer chain end, cf. EP 264 214.

Another example of a termination reagent is 1,1-diphenylethylene. The living chain end is thereby terminated by addition of 1,1-diphenylethylene and a base, whereby a diphenyl-substituted double bond is introduced at the chain end, cf. J. Feldthusen, B. Ivan, A.H.E. Muller and J. Kops, Macromol. Rep. 1995, A32, 639, J. Feldthusen, B. Ivan and A.H.E. Müller, Macromolecules 1997, 30, 6989 and Macromolecules 1998, 31, 578, DE-A 19648028 and DE-A 19610350.

Furthermore, conjugated dienes, for example butadiene, are suitable as termination reagents. Here, the reactive chain end is reacted with the conjugated diene and then deactivated as described above, cf. DE-A 40 25 961. In addition, telechelic polyisobutenes are obtainable by the process according to the invention which have an alcohol function at all chain ends, which are derived from the radical XO- of the compound (I). For this purpose, two or more living polymer chains are coupled by adding a coupling agent. Coupling means the formation of chemical bonds between the reactive chain ends, so that two or more polymer chains of the living polyisobutene formed according to the invention are connected via their distal ends to form a molecule. The molecules obtained by coupling are symmetric telechelic or star-shaped molecules with functions -OX at the molecular ends or the ends of the branches of the star-shaped molecule. In this way, it is also possible by coupling living copolymers of the type AB ^{+ to} prepare triblock copolymers of the AB-BA type in which A is a polyisobutene block and B is a different polymer block, for example a polyvinylaromatic block.

Suitable coupling agents include, for example, at least two electrolytic leaving groups, all of which are allylated to the same or different double bonds, e.g. Trialkylsilylgruppen, so that the cationic center of a reactive chain end can attach in a concerted reaction with cleavage of the leaving group and shift of the double bond. Other coupling agents have at least one conjugated system to which the cationic center of a reactive chain end can add electrophilically to form a stabilized cation. By cleavage of a leaving group, e.g. of a proton, then forming a stable s-bond to the polymer chain with reformation of the conjugated system. Several of these conjugated systems can be linked by inert spacers.

Suitable coupling agents include:

(i) compounds having at least two 5-membered heterocycles having a heteroatom selected from oxygen, sulfur and nitrogen, e.g. organic compounds having at least two furan rings, such as

wherein R is Ci-Cio-alkylene, preferably methylene or 2,2-propanediyl;

(ii) Compounds having at least two allyl-substituted trialkylsilyl groups, such as 1,1-bis (trialkylsilylmethyl) ethylene, e.g. 1, 1-bis (trimethylsilylmethyl) ethylene, or as

Bis [(trialkylsilyl) -propenyl] benzenes, e.g.

(where Me is methyl), (iii) compounds having at least two vinylidene groups conjugated to each two aromatic rings, such as bis-diphenylethylenes, eg

A description of suitable coupling agents can be found in the following references; the

Coupling reaction can be carried out analogously to the reactions described there: R. Faust, S. Hadjikyriacou, Macromolecules 2000, 33, 730-733; R. Faust, S. Hadjikyriacou, Macromolecules 1999, 32, 6393-6399; R. Faust, S. Hadjikyriacou, Polym. Bull. 1999, 43, 121-128; R. Faust, Y. Bae, Macromolecules 1997, 30, 198; R. Faust, Y. Bae, Macromolecules 1998, 31, 2480; R. Storey, Maggio, Polymer Preprints 1998, 39, 327-328; WO99 / 24480; US 5,690,861 and US 5,981,785.

The coupling is usually carried out in the presence of a Lewis acid, wherein such Lewis acids are suitable, which are also used to carry out the actual polymerization reaction bar. For carrying out the coupling reaction, the same solvents and temperatures are also suitable as are used for carrying out the actual polymerization reaction. Conveniently, the coupling can therefore be carried out as a one-pot reaction following the polymerization reaction in the same solvent in the presence of the Lewis acid used for the polymerization. Usually, a molar amount of the coupling agent is used which corresponds approximately to the quotient of the molar amount of the initiator of the formula I used for the polymerization, divided by the number of coupling sites of the coupling agent.

After termination (deactivation and / or introduction of an ethylenically unsaturated terminal group) or coupling, the solvent is usually removed in suitable aggregates such as rotary, falling film or thin film evaporators or by relaxation of the reaction solution.

In one embodiment of the process according to the invention, the polymerization is carried out batchwise, ie as a batch reaction. For this purpose, it is possible, for example, to introduce isobutene in a solvent, to add initiator and, if appropriate, further additives, such as siloxanes, and to start the reaction with a Lewis acid. It is also possible solvent, initiator, Lewis acid and optionally to provide further additives such as siloxanes and to control the reaction by continuous addition of isobutene. In all cases, the reaction temperature will be maintained in the desired range by suitable cooling measures. A particular challenge in the polymerization is given by a high heat of reaction in a short period of time. A further object of the present invention was therefore to provide a process which makes it possible to control the rapid heat release of the reaction. In particular, polymerizations carried out on an industrial scale present a challenge with regard to the rapid dissipation of heat, which is the case for relatively large amounts of sales. A further object of the present invention was therefore to provide a process which makes it possible to carry out polymerization reactions on an industrial scale.

In another embodiment of the process according to the invention, the polymerization is carried out continuously. In order to achieve higher molecular weights in a living cationic polymerization, it is necessary to achieve a good temperature control over the heat removal in continuous polymerization processes. Correspondingly, reactors with high heat transfer surfaces based on the reaction volume are suitable. In addition to tubular reactors, these can also be reactors with rectangular channels, stirred tank reactors or certain micro or milli reactors. Micro- or Milli-reactors allow a good temperature control even with strongly exothermic reactions. Due to the larger ratio of surface area to reactor volume, for example, a very good heat supply or removal is made possible, which is why even highly exothermic reactions can be carried out approximately isothermally. In addition, Milli reactors in particular can be scaled up well to industrial scale due to their design. In a preferred embodiment of the process according to the invention, the polymerization is carried out in a continuous process which comprises at least the following steps:

(I) continuous metering of isobutene, solvent, initiator, and if desired further additives in a mixer and mixing the starting materials in the mixing unit;

(II) starting the continuous polymerization by continuously metering in a Lewis acid and mixing with the reactants at the reaction temperature; (III) Continuous polymerization, by passing the resulting reaction mixture through at least one temperature-controlled reaction zone reaction zone.

The following apparatuses may preferably be used: the polymerization is preferably carried out using Milli reactors, in particular if it is carried out continuously. Milli reactors differ from conventional equipment in their characteristic dimension. Under the characteristic see dimension of a device through which flows, for example, a mixer or a reactor, is understood in the context of the present invention, the smallest, perpendicular to the flow direction expansion. The characteristic dimension of Milli reactors is significantly smaller than that of conventional equipment. It can be especially in the millimeter range. Compared to conventional reactors Milli reactors therefore show a significantly different behavior with respect to the heat and mass transfer processes that take place. Due to the larger ratio of surface area to reactor volume, for example, a very good heat supply or removal is made possible, which is why it is also possible to carry out isothermally strongly endo-thermic or exothermic reactions. Compared to micro-reactors whose characteristic dimensions are in the micrometer range, milli-reactors are less susceptible to clogging due to the characteristic dimensions and thus have a higher robustness with regard to an industrial application.

Conventional reactors have a characteristic dimension of> 30 mm, milli-reactors, however, of 30 mm or smaller. The characteristic dimension of a milli-reactor for the polymerization of isobutene or of an isobutene-containing monomer mixture is generally at most 30 mm, in particular 0.1 to 30 mm or preferably 0.3 to 30 mm or particularly preferably 0.5 to 30 mm; preferably at most 20 mm, e.g. 0.1 to 20 mm, or preferably 0.3 to 20 mm, or more preferably 0.5 to 20 mm; more preferably at most 15 mm, e.g. 0.1 to 15 mm, or preferably 0.3 to 15 mm, or more preferably 0.5 to 15 mm; more preferably at most 10 mm, e.g. 0.1 to 10 mm, or preferably 0.3 to 10 mm, or more preferably 0.5 to 10 mm; even more preferably at most 8 mm, e.g. 0.1 to 8 mm, or preferably 0.3 to 8 mm, or more preferably 0.5 to 8 mm; in particular at most 6 mm, e.g. 0.1 to 6 mm, or preferably 0.3 to 6 mm, or more preferably 0.5 to 6 mm; and especially at most 4 mm, e.g. 0.1 to 4 mm, or preferably 0.3 to 4 mm, or more preferably 0.5 to 4 mm.

Milli reactors to be used according to the invention are preferably selected from temperature-controllable tubular reactors, shell-and-tube heat exchangers, plate heat exchangers and temperature-controlled tubular reactors with internals. Tube reactors to be used according to the invention, tube bundle heat exchangers and plate heat exchangers have tube dimensions as characteristic dimensions. Capillary diameter in the range of preferably 0.1 mm to 25 mm, more preferably in the range of 0.5 mm to 6 mm, more preferably in the range of 0.7 to 5 mm and in particular in the range of 0.8 mm to 4 mm, and layer heights or channel widths in the range of preferably 0.2 mm to 10 mm, particularly preferably in the range of 0.2 mm to 6 mm and in particular in the range of 0.2 mm to 4 mm. Pipe reactors with internals to be used according to the invention have pipe diameters in the range from 5 mm to 500 mm, preferably in the range from 8 mm to 200 mm and particularly preferably in the range from 10 mm to 100 mm. Alternatively, also comparable plate channels with inserted mixing structures can be used according to the invention. They have heights in the range of 1 mm to 20 mm and widths in the range of 10 mm to 1000 mm and in particular in the range of 10 mm to 500 mm. Optionally, the tube reactors may contain mixing elements, which are traversed by tempering channels.

The optimum characteristic dimension results here from the requirements for the permissible anisothermic nature of the reaction regime, the maximum permissible pressure loss and the susceptibility to blockage of the reactor.

Particularly preferred Milli reactors are: tube reactors made of capillaries, capillary bundles with tube cross sections from 0.1 to 25 mm, preferably from 0.5 to 6 mm, more preferably from 0.7 to 4 mm, with or without additional mixing internals, wherein the tubes or capillaries can be lapped by a tempering medium; »Tubular reactors in which the heat transfer medium is conducted in the capillaries / tubes, and the product to be tempered is guided around the tubes and homogenised by means of components (mixing elements);

• Plate reactors constructed as plate heat exchangers with insulated parallel channels, networks of channels or surfaces equipped with or without flow-breaking internals (posts), the plates product and heat carrier parallel or in a layered structure, which alternately heat carrier and product -Lagen, so that during the reaction, the chemical and thermal homogeneity can be ensured;

Reactors with "flat" channel structures, which have a "milli-dimension" only at height and can be almost arbitrarily wide whose typical comb-shaped internals prevent the formation of an airfoil and to an important for the defined reaction and residence time, tight Lead residence time distribution.

In a preferred embodiment of the invention, at least one reactor is used which largely has the residence time characteristic of a plug flow. If a plug flow is present in a tubular reactor, the state of the reaction mixture (eg temperature, composition, etc.) can vary in the flow direction, but for each individual cross section perpendicular to the flow direction, the state of the reaction mixture is the same. Thus all volume elements entering the tube have the same residence time in the reactor. Figuratively speaking, the liquid flows through the tube as if it were a series of easily slipping through the tube. In addition, the cross-mixing due to the intensified mass transport perpendicular to the flow direction can compensate for the concentration gradient perpendicular to the flow direction. Despite the mostly laminar flow through apparatuses with microstructures, backmixing can thus be avoided and a narrow residence time distribution similar to that achieved with an ideal flow tube can be achieved. The Bodensteinzahl Bo is a dimensionless index and describes the ratio of the convection current to the dispersion stream (eg M. Baerns, H. Hofmann, A. Renken, Chemical Reaction Engineering, Textbook of Technical Chemistry, Volume 1, 2nd edition, p 332 ff), it thus characterizes the backmixing within a system:

^ ax where u stands for the flow velocity [ms- ¹ ], L for the length of the reactor [m] and D _ax for the axial dispersion coefficient [m ² rr ¹ ]. A zero number of bottoms equals complete backmixing in an ideal continuous stirred tank. By contrast, an infinite number of bottom stones means absolutely no backmixing, as in the case of continuous flow through an ideal flow tube. In capillary reactors, the desired backmixing behavior can be adjusted by adjusting the ratio of length to diameter as a function of the material parameters and the flow state. The underlying calculation procedures are known to the person skilled in the art (eg M. Baerns, H. Hofmann, A. Renken: Chemical Reaction Engineering, Textbook of Technical Chemistry, Volume 1, 2nd Edition, p. 339 ff). If a behavior which is as low as possible with low back mixing is to be realized, then the groundstone number defined above is preferably chosen to be greater than 10, particularly preferably greater than 20 and in particular greater than 50. For a Bodenstein number of greater than 100, the capillary reactor then has largely a Propfenströmungscharakter. Austenitic stainless steels, such as 1 .4541 or 1 .4571, generally known as V4A or as V2A, as well as stainless steels of the US types SS316 and SS317Ti, have proven advantageous as materials for the mixers and reactors to be used according to the invention , At higher temperatures and under corrosive conditions, polyether ketones are also suitable. But it can also be more resistant to corrosion Hastelloy® types, glass or ceramic as materials and / or corresponding coatings, such as

TiN3, Ni-PTFE, Ni-PFA or the like can be used for the reactors to be used according to the invention.

The reactors are designed so that the heat transfer surfaces are in very good contact with a tempering medium, so that a very good heat transfer between the reactants Onsmischung in the reaction zone and the temperature control is possible and a largely isothermal reaction is possible.

The temperature control medium should have a sufficiently high heat capacity, be circulated intensively and be provided with a thermostating unit of sufficient capacity. The heat transfer between the reaction zone and the temperature control medium should be as good as possible in order to ensure the most homogeneous possible temperature distribution in the reaction zone. Depending on the exothermicity and the characteristic reaction time of the polymerization reaction, the ratio of heat exchange surface to reaction volume should generally be between about 50 and about 5000 m ² / m ³ , preferably between about 100 and about 3000 m ² / m ³ . more preferably between about 150 and about 2000 m ² / m ³ and in particular between about 200 and about 1300 m ² / m ^{3 are} selected. Typically, the values for reactors with production capacities of approx. 5000 tonnes per year are in the range of approx. 200 m ² / m ³ , for reactors with production capacities of approx. 500 tonnes per year in the range of approx. 500 m ² / m ³ and for reactors on a laboratory scale at about 600 to 1300 m ² / m ³ .

Furthermore, the heat transfer coefficient on the side of the reaction medium should generally be more than 50 W / m ² K, preferably more than 100 W / m ² K, more preferably more than 200 W / m ² K and in particular more than 400 W / m ² K amount.

The bifunctional polyisobutenes prepared by the process according to the invention have a narrow molecular weight distribution. The polydispersity index PDI = M _w / M _n is usually below 2.0, preferably below 1.60, more preferably below 1.40 and in particular below 1.35.

The process according to the invention is preferably used for the preparation of bifunctional polyisobutenes having a number average molecular weight M _{n of} from 200 to 100,000, more preferably from 400 to 50,000 and in particular from 500 to 15,000.

The bifunctional polyisobutenes prepared according to the invention are terminated at one end of the chain (chain start) by alcohol function XO- of the initiator of the formula I. The opposite (distal) end group is preferably a group -CH 2 -C (CH 2) 2-halogen, more preferably -CH 2 -C (CH 2) 2 -Cl. Alternatively, the opposite group is preferably an ethylenically unsaturated group, as described above, thermally or by reacting the halogen-substituted chain end with a suitable base or by reacting the living polyisobutene chains formed in the polymerization with a trialkylallylsilane compound having 1, 1 Diphenylethylene or a conjugated diene. In addition, polyisobutenes which are terminated at all chain ends by functions -OX can also be obtained by the process according to the invention by coupling the living polyisobutene chains. A further subject of the present invention is a polyisobutene which is terminated on at least one molecule end by a group of the formula V,

wherein X, Ri, R _2, R ₃ and R _{4 are} as defined above, or a functionalization product thereof obtained by i) hydrosilylation,

ii) hydrosulforation,

iii) electrophilic substitution on aromatics,

iv) epoxidation and, if desired, reaction with nucleophiles,

v) hydroboration and, if desired, oxidative cleavage,

vi) reaction with an enophile in an ene reaction,

vii) addition of halogens or hydrogen halides or

viii) hydroformylation of a group of formula V is available. The functionalizations mentioned can be carried out as follows: i) Hydrosilylation For functionalization, a polyisobutene prepared by the process according to the invention can be subjected to a reaction with a silane in the presence of a silylation catalyst to give a polyisobutene which is at least partially functionalized with silyl groups. Suitable hydrosilylation catalysts are, for example, transition metal catalysts, wherein the transition metal is preferably selected from Pt, Pd, Rh, Ru and Ir. Suitable platinum catalysts include, for example, platinum in finely divided form ("platinum black"), platinum chloride and platinum complexes such as hexachloroplatinic acid or divinyldisiloxane-platinum complexes, eg tetramethyldivinyldisiloxane-platinum complexes. Suitable rhodium catalysts are, for example, (RhCl (P (C 6 H ₅ ) 3) 3) and RhC. Also suitable are RuC and IrC. Suitable catalysts are also Lewis acids such as AICI3 or TiCl ₄ and peroxides. It may be advantageous to use combinations or mixtures of the aforementioned catalysts. Suitable silanes are, for example, halogenated silanes, such as trichlorosilane, methyldichlorosilane, dimethylchlorosilane and trimethylsiloxydichlorosilane; Alkoxysilanes, such as methyldimethoxysilane, phenyldimethoxysilane, 1,3,3,5,5,7,7-heptamethyl-1,1-dimethoxytetrasiloxane and trialkoxysilanes, eg. B. trimethoxysilane and triethoxysilane, and acyloxysilanes. Trialkoxysilanes are preferably used.

The reaction temperature in the silylation is preferably in a range of 0 to 140 ° C, more preferably 40 to 120 ° C. The reaction is usually carried out under normal pressure, but may also be carried out at elevated pressures, e.g. in the range of about 1.5 to 20 bar, or reduced pressures, e.g. 200 to 600 mbar.

The reaction can be carried out without solvent or in the presence of a suitable solvent. Preferred solvents are, for example, toluene, tetrahydrofuran and chloroform. Ii) Hydrosulfurization

For functionalization, a polyisobutene prepared by the process according to the invention can be subjected to a reaction with hydrogen sulfide or a thiol, such as alkyl- or arylthiols, hydroxymercaptans, aminomercaptans, thiocarboxylic acids or silanethiols, to give a polyisobutene which is at least partially functionalized with thio groups. Suitable hydro-alkylthio additions are described in J. March, Advanced Organic Chemistry, 4th Edition, John Wiley & Sons, pp. 766-767, incorporated herein by reference. The reaction can usually be carried out both in the absence and in the presence of initiators and in the presence of electromagnetic radiation. Upon addition of hydrogen sulfide, functionalized polyisobutenes are obtained with thiol groups. The addition of hydrogen sulfide is preferably carried out at temperatures below 100 ° C and a pressure of 1 to 50 bar, more preferably of about 10 bar. In addition, the addition is preferably carried out in the presence of a cation exchange resin, such as Amberlyst 15. In the reaction with thiols in the absence of initiators are usually obtained the Markovnikov addition products to the double bond. Suitable initiators of the hydro-alkylthio addition are, for example, protic and Lewis acids, such as concentrated sulfuric acid or AlC, and acidic cation exchangers, such as Amberlyst 15. Suitable initiators are furthermore those which are capable of forming free radicals, such as peroxides or azo compounds. Hydro-alkylthio addition in the presence of these initiators usually gives the anti-Markovnikov addition products. The reaction can furthermore be carried out in the presence of electromagnetic radiation having a wavelength of 400 to 10 nm, preferably 200 to 300 nm. iii) Electrophilic substitution on aromatics For derivatization, a polyisobutene prepared according to the process of the invention can be reacted with a compound having at least one aromatic or heteroaromatic group in the presence of an alkylation catalyst. Suitable aromatic and heteroaromatic compounds, catalysts and reaction conditions of this so-called Friedel-Crafts alkylation are described, for example, in J. March, Advanced Organic Chemistry, 4th Edition, published by John Wiley & Sons, pages 534-539, which is incorporated herein by reference.

Preferably, an activated aromatic compound is used for the alkylation. Suitable aromatic compounds are, for example, alkylaromatics, alkoxyaromatics, hydroxyaromatics or activated heteroaromatics, such as thiophenes or furans.

The aromatic hydroxy compound used for the alkylation is preferably selected from phenolic compounds having 1, 2 or 3 OH groups which may optionally have at least one further substituent. Preferred further substituents are C 1 -C 8 -alkyl groups and in particular methyl and ethyl. Particular preference is given to compounds of the general formula

wherein R ¹ and R ^{2 are} independently hydrogen, OH or CH ₃ . Particularly preferred are phenol, the cresol isomers, catechol, resorcinol, pyrogallol, fluoroglucinol and the xylenol isomers. In particular, phenol, o-cresol and p-cresol are used. If desired, it is also possible to use mixtures of the abovementioned compounds for the alkylation. Also suitable are polyaromatics, such as polystyrene, polyphenylene oxide or polyphenylene sulfide, or copolymers of aromatics, for example with butadiene, isoprene, (meth) acrylic acid derivatives, ethylene or propylene.

The catalyst is preferably selected from Lewis acidic alkylation catalysts, which in the context of the present application is understood as meaning both individual acceptor atoms and acceptor-ligand complexes, molecules, etc., provided that they contain (outwardly) Lewis acid (electron acceptor). ) Have properties. By beispielswei- include se AICIs, AlBr _3, BF _3, BF ₃ -2 C ₆ H ₅ OH, BF ₃ [0 (C2H _{5) 2]} 2, TiCl, SnCl _4, AIC ₂ H ₅ CI _2, FeCl _3, SbCI ₅ and SbF ₅ . These alkylation catalysts can be used together with a cocatalyst, for example an ether. Suitable ethers are di- (C 1 -C 8) -alkyl ethers, such as dimethyl ether, diethyl ether, di-n-propyl ether, and tetrahydrofuran, di (C 5 -C 8) -cycloalkyl ethers, such as dicyclohexyl ether, and ethers having at least one aromatic hydrocarbon radical, like anisole. If a catalyst-cocatalyst complex is used for Friedel-Crafts alkylation, the molar ratio of catalyst to cocatalyst is preferably in the range from 1:10 to 10: 1. The reaction can also be carried out with protic acids such as sulfuric acid, phosphoric phosphoric acid or trifluoromethanesulfonic acid are catalyzed. Organic protic acids may also be present in polymer bound form, for example as ion exchange resin. Also suitable are zeolites and inorganic polyacids. The alkylation can be carried out solvent-free or in a solvent. Examples of suitable solvents are n-alkanes and mixtures thereof and alkylaromatics, such as toluene, ethylbenzene and xylene, and halogenated derivatives thereof.

The alkylation is preferably carried out at temperatures between -10 ° C and + 100 ° C. The reaction is usually carried out at atmospheric pressure, but can also be carried out at higher or lower pressures.

By suitable choice of the molar ratios of aromatic or heteroaromatic compound to polyisobutene and the catalyst, the proportion of alkylated products achieved and their degree of alkylation can be adjusted. Substantially monoalkylated polyisobutenylphenols are generally obtained with an excess of phenol or in the presence of a Lewis acidic alkylation catalyst if, in addition, an ether is used as cocatalyst. For further functionalization, the polyisobutenylphenol obtained can be subjected to a reaction in the Mannich reaction with at least one aldehyde, for example formaldehyde, and at least one amine having at least one primary or secondary amine function, to give a compound alkylated with polyisobutene and additionally at least partially aminoalkylated receives. It is also possible to use reaction and / or condensation products of aldehyde and / or amine. The preparation of such compounds are described in WO 01/25293 and WO 01/25294, to which reference is hereby fully made. iv) epoxidation

For functionalization, a polyisobutene prepared according to the process according to the invention can be reacted with at least one peroxide compound to give an at least partially epoxidized polyisobutene. Suitable methods for epoxidation are described in J. March, Advanced Organic Chemistry, 4th Edition, John Wiley & Sons, pp. 826-829, which is hereby incorporated by reference. Preferably, the peroxide compound used is at least one peracid, such as m-chloroperbenzoic acid, performic acid, peracetic acid, trifluoroacetic acid, perbenzoic acid and 3,5-dinitroperbenzoic acid. The preparation of the peracids can be carried out in situ from the corresponding acids and H2O2 optionally in the presence of mineral acids. Further suitable epoxidation reagents are, for example, alkaline hydrogen peroxide, molecular oxygen and alkyl peroxides, such as tert-butyl hydroperoxide. Suitable solvents for the epoxidation are, for example, conventional, non-polar solvents. Particularly suitable solvents are hydrocarbons such as Toluene, xylene, hexane or heptane. The epoxide formed can then be reacted ring-opening with water, acids, alcohols, thiols or primary or secondary amines to give, inter alia, diols, glycol ethers, glycol thioethers and amines. v) hydroboration

For functionalization, a polyisobutene prepared according to the process of the invention can be subjected to a reaction with a (optionally generated in situ) borane to give an at least partially hydroxylated polyisobutene. Suitable hydroboration processes are described in J. March, Advanced Organic Chemistry, 4th Edition, John

Wiley & Sons, pp. 783-789, to which reference is hereby made. Suitable hydroboration reagents are, for example, diborane, which is generally generated in situ by reacting sodium borohydride with BF 3 etherate, diisamylborane (bis [3-methylbut-2-yl] borane), 1, 1, 2-trimethyl-propylborane , 9-Borbicyclo [3.3.1] nonane, diisocamphenylborane, which are obtainable by hydroborating the corresponding alkenes with diborane, chloroborane-dimethylsulfide, alkyldichloroboranes or H ₃ BN (C ₂ H ₅ ) 2.

Usually, the hydroboration is carried out in a solvent. Suitable solvents for hydroboration are, for example, acyclic ethers, such as diethyl ether, methyl tert-butyl ether, dimethoxyethane, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, cyclic ethers, such as tetrahydrofuran or dioxane, and hydrocarbons, such as hexane or toluene, or mixtures thereof. The reaction temperature is usually determined by the reactivity of the hydroboration agent and is normally between the melting and boiling points of the reaction mixture, preferably in the range of 0 ° C to 60 ° C.

Usually, the hydroborating agent is used in excess with respect to the alkene. The boron atom preferably adds to the less substituted and thus less sterically hindered carbon atom. Usually, the alkyl boranes formed are not isolated, but by subsequent

Conversion converted directly into the value products. A very important implementation of the alkylboranes is the reaction with alkaline hydrogen peroxide to give an alcohol which preferably corresponds formally to the anti-Markovnikov hydration of the alkene. Furthermore, the resulting alkylboranes can be subjected to reaction with bromine in the presence of hydroxide ions to give the bromide. vi) ene reaction

For functionalization, a polyisobutene prepared according to the process of the invention can be reacted with at least one alkene which has an electrophile-substituted double bond in an ene reaction (see, for example, DE-A 4 319 672 or H. Mach and P. Rath in Chem Lubrication Science V (1999), pp. 175-185, incorporated herein by reference). In the ene reaction, an alkene designated as En having an allyl-standing hydrogen atom is reacted with an electrophilic alkene, so-called enophile, in a pericyclic reaction comprising a carbon-carbon bond, a double bond shift, and a hydrogen transfer. In the present case, the polyisobutene reacts as En. Suitable enophiles are compounds which are also used as dienophiles in the Diels-Alder reaction. Preference is given to using maleic anhydride as the enophile. This results in at least partially functionalized with succinic anhydride (Succinanhydridgruppen) polyisobutenes. The ene reaction may optionally be carried out in the presence of a Lewis acid catalyst. Suitable examples are aluminum chloride and ethylaluminum chloride.

For further functionalization, it is possible, for example, to subject a polyisobutene derivatized with succinic anhydride groups to a subsequent reaction which is selected from: a) reaction with at least one amine to give a polyisobutene functionalized at least in part with succinimide groups and / or succinamide groups, b) reaction with at least one alcohol to obtain a polyisobutene which is at least partially functionalized with succinic ester groups, and c) reaction with at least one thiol to give a polyisobutene which is at least partially functionalized with sucino-thioester groups. vii) addition of halogen or hydrogen halides

For functionalization, a polyisobutene prepared by the process according to the invention can be subjected to a reaction with hydrogen halide or a halogen to give a polyisobutene which is at least partially functionalized with halogen groups. Suitable reaction conditions of the hydrohalo addition are described in J. March, Advanced Organic Chemistry, 4th Edition, John Wiley & Sons, pp. 758-759, which is incorporated herein by reference. In principle, HF, HCl, HBr and Hl are suitable for the addition of hydrogen halide. The addition of Hl, HBr and HF can generally be carried out at room temperature, whereas elevated temperatures are generally used for the addition of HCl.

The addition of hydrogen halides can be carried out in principle in the absence or in the presence of initiators or of electromagnetic radiation. When added in the absence of initiators, especially peroxides, the Markovnikov addition products are generally obtained. With the addition of peroxides, the addition of HBr usually leads to anti-Markovnikov products. The halogenation of double bonds is described in J. March, Advanced Organic Chemistry, 4th Edition, John Wiley & Sons, pp. 812-814, incorporated herein by reference. For the addition of Cl, Br and I, the free halogens can be used. To obtain mixed-halogenated compounds, the use of interhalogen compounds is known. For the addition of fluorine usually fluorine-containing compounds are used, such as C0F3, XeF2 and mixtures of PbC "2 and SF _4. Bromine usually adds at room temperature in good yields of double bonds.For the addition of chlorine in addition to the free halogen and chlorine-containing Reagents such as SO 2 Cl 2, PCI 5, etc. If chlorine or bromine is used for the halogenation in the presence of electromagnetic radiation, essentially the products of the radical substitution on the polymer chain are obtained, and not or only to a limited extent addition products to the terminal double bond. Preferred functionalization products are the bisepoxides, dithiols, diols (Antimarkovnikov products such as those obtainable from hydroboration and Markovnikov products, such as those obtainable from the epoxidation and subsequent reaction of the epoxide with water and optionally an acid) and bis (trialkoxy -silane). Certain through the invent Appropriate method available polyisobutenes, which on a

Chain ends are terminated by a group of the formula V and at the opposite end of the chain have a different, previously described, terminating group, can be differentially functionalized due to the different reactivities of the terminating groups. This is advantageous, in particular, for the use of the polyisobutene in fuels and lubricants since hydrophilic and hydrophobic properties must coincide here. Furthermore, the easy accessibility of the compound of formula (I) is advantageous. Since only a unilaterally growing chain is initiated with the compound of the formula (I), the required amount of Lewis acid and terminating reagent is reduced in comparison to polyfunctional initiators. In addition, the terminating group derived from the initiator is not subject to the side reactions mentioned above, which occur when using polyfunctional aromatic initiators of the prior art. viii) Hydroformylation With regard to the hydroformylation or oxo synthesis, reference is made to the 2012 edition of Ullmann's Encyclopaedia of Industrial Chemistry (Online ISBN: 9783527306732). There you will find in the chapters "Oxo Synthesis" (author H. Bahrmann and H. Bach;

DOI: 10.1002 / 14356007. a18_321) and "carbonylation" (author W. Bertleff, M. Roeper, X. Sava, DOI: 10.1002 / 14356007.a05_217.pub2) describe the reaction. This and the literature cited therein are hereby expressly incorporated by reference. The following examples are intended to illustrate the invention in more detail. Examples Example 1: Preparation of 2,2,4,4-tetramethyltetrahydrofuran (TMTHF)

In a 500 ml four-necked flask equipped with dropping funnel and distillation bridge with template, 150g of silica gel were presented. To this was added a solution which was concentrated by addition of 12 g. H2SO4 and 2.4 g NaOH to 150 ml water. Under IM2 stream, the water was distilled off to a bath temperature of 170 ° C. Then 360 g of molten 2,2,4-trimethylpentane-diol- (1, 3) was added dropwise over 4 h, wherein the bath temperature was raised to 190 ° C. It distilled crude TMTHF collected in the template over NaHCO 3 solution. In the separating funnel, the aqueous phase was separated and the organic phase was washed three times with water and dried with Na ₂ SO ₄ .

The organic phase was distilled and there were collected 266 g of a fraction of the boiling range 1 18 ° C-138 ° C. This was 81% TMTHF according to NMR:

 H-FT NMR (500 MHz, 16 scans, CD2CI2):

1, 22 ppm, 6H, S; 1.38 ppm, 6H, S; 1, 73 ppm, 2H, S; 3.60 ppm, 2H, S.

Example 2 Preparation of 4-Chloro, 2,2,4-trimethylpentylacetate In a 1000 ml four-necked flask equipped with dropping funnel, thermometer and stirrer, 266 g of TMTHF from Example 1 (81%) were initially charged and 2 g of zinc powder were added , With ice-bath cooling, 138.5 g of acetyl chloride were added dropwise in the region of 15 ° C.-25 ° C. and the mixture was stirred at 45 ° C. for 45 minutes. At room temperature, washed three times with NaHCO 3 solution, diluted with CH 2 Cl 2 and washed with water. It was dried with Na ₂ SO ₄ , filtered and the solvent was removed on a rotary evaporator at 50 ° C. and 200 mbar. 305 g of a readily mobile liquid, which according to NMR to 75% of 4-chloro, 2,2,4-trimethylpentyl acetate (besides TMTHF and 2,2,4-trimethylpentene (-4) ylacetat). H-FT NMR (500 MHz, 16 scans, CD2CI2):

1, 09 ppm, 6H, S; 1.66 ppm, 6H, S; 1, 93 ppm, 2H, S; 2.08 ppm, 3H, S; 3.90 ppm, 2H, S.

Example 3 Polymerization of isobutene with 4-chloro, 2,2,4-trimethylpentyl acetate In a 2 l four-necked flask, 1000 ml of dry n-chlorobutane and 134 g of isobutene were initially charged at -10.degree. Then 81 g of 4-chloro, 2,2,4-trimethylpentyl acetate from Example 2 (75%) and 3 g of pyridine were added and the polymerization was started with 40 ml of TiCl ₄ . By means of cooling bath held a temperature of -10 ° C over 60 minutes. Then 500 ml of hexane were added and quenched with 300 ml of isopropanol. The hexane / polyisobutene phase was separated, washed three times with water and dried with Na ₂ S0 ₄ . The solvent was removed on a rotary evaporator at 120 ° C and 50 mbar. 160 g of a clear, light oil were obtained.

GPC: Mn = 1200; Mw = 1900 H-FT-NMR (500 MHz, 16 scans, CD ₂ Cl ₂ ):

3.79 ppm (CH ₃ -CO-CH ₂ -C (CH ₃ ) ₂ -); 2.03 ppm (CJ? -CO-CH ₂ -C (CH ₃ ) ₂ -); 1.52 ppm (CH ₃ -CO-CH ₂ -C (CH ₃ ) ₂ -); 1.43 ppm (- [CH ₂ -C (CH ₃ ) ₂ ] _n -); 1, 12 ppm (- [CH ₂ -C (CH ₃ ) ₂ ] _n -);

GPC and NMR give a functionality of 70%.

Claims

claims

Process for the preparation of bifunctional polyisobutenes in which isobutene or an isobutene-containing monomer mixture in the presence of a Lewis acid and a compound of the formula I

X is an acyl radical of the formula R 5 CO- or the radical of an organic

 or inorganic acid group which, with its central atom Z,

 which is selected from S, P, N and B and at least one double

 carries attached oxygen atom, is covalently bonded to the oxygen atom of the compound (I) and their possibly existing

 Hydroxyl functions are present in esterified form,

R 1 to R ₄ are identical or different and represent hydrogen, a aliphatschen, eye loaliphatischen or aromatic hydrocarbon radical having 1 to 20 carbon atoms, and

R 5 has the same meanings as R 1 to R ₄ and additionally in the case of n = 2 to 4 at (nl) site (s) may be further substituted with one or more further acyl groups polymerized.

The process of claim 1, wherein the Lewis acid is selected from titanium tetrachloride, boron trichloride, tin tetrachloride, aluminum trichloride, dialkylaluminum chlorides, alkylaluminum dichlorides, vanadium pentachloride, iron trichloride and boron trifluoride.

A process according to any one of the preceding claims, wherein the polymerization is carried out in the presence of an electron donor selected from pyridines, amides, lactams, ethers, amines, esters, thioethers, sulfoxides, nitriles, phosphines and non-polymerizable aprotic organosilicon compounds containing at least one have oxygen-bonded organic radical.

A process as claimed in any of claims 1 to 3, wherein the living polyisobutene formed in the polymerization of isobutene or of the isobutene-containing monomer mixture is reacted with a coupling agent, whereby two or more polymer chains are reacted. be connected via their distal ends to form a molecule. The method of claim 4, wherein the coupling agent is selected from

(i) Compounds containing at least two 5-membered heterocycles with

 one selected from among oxygen, sulfur and nitrogen

 Have heteroatom,

(ii) compounds having at least two allyl-containing trialkylsilyl groups, and

(iii) Compounds having at least two vinylidene groups conjugated to two aromatic rings each.

Method according to one of claims 1 to 5, characterized in that the polymerization is carried out in a continuous process comprising at least the following steps:

(I) continuous metering of isobutene, solvent, initiator and, if desired, further additives into a mixer and mixing of the starting materials in the mixing unit;

(II) starting the continuous polymerization by continuously metering in a Lewis acid and mixing with the reactants at the reaction temperature;

(III) Continuous polymerization, by passing the resulting reaction mixture through at least one temperature-controlled reaction zone reaction zone.

Method according to one of claims 1 to 6, characterized in that one carries out the polymerization in Milli reactors with a characteristic dimension of 0.1 to 30 mm.

Polyisobutene terminated at at least one molecular end by a group of the formula V.

wherein X, R1, R2, R3 and _R4 are as defined above, or a functionalization product thereof, obtainable by i) hydrosilylation,

ii) hydrosulfurization,

iii) electrophilic substitution on aromatics,

iv) epoxidation and optionally reaction with nucleophiles, v) hydroboration and optionally oxidative cleavage, vi) reaction with an enophile in an ene reaction,

vii) addition of halogens or hydrogen halides or viii) hydroformylation of a group of formula V.