EP1915406A1

EP1915406A1 - Method for producing copolymers made from isobutene and at least one vinylaromatic component

Info

Publication number: EP1915406A1
Application number: EP06792803A
Authority: EP
Inventors: Hans Peter Rath; Hans-Michael Walter; Oskar Nuyken; Fritz Elmar Kuehn; Yanmei Zhang; Hui Yee Yeong; Brigitte Voit; Radha Krishnan Narayanan
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2005-08-12
Filing date: 2006-08-11
Publication date: 2008-04-30
Also published as: DE102005038282A1; KR20080039461A; CN101283006A; US20100292422A1; WO2007020248A1

Abstract

The invention relates to a method for producing copolymers made from isobutene and at least one vinylaromatic component. Said method consists of polymerising isobutene or a hydrocarbon mixture containing isobutene with at least one vinylaromatic compound in the presence of a solvent-stable transistion metal complex comprising slightly co-ordinating anions as a polymerisation catalyst.The invention also relates to copolymers made of isobutene and at least one vinylaromatic compound, which can be obtained by means of said inventive method, in addition to specific functionalisation products therefrom.

Description

Process for the preparation of copolymers of isobutene and at least one vinyl aromatic compound

description

The present invention relates to a process for preparing copolymers of isobutene and at least one vinyl aromatic compound, in particular isobutene-styrene copolymers, in which isobutene or an isobutene-containing hydrocarbon mixture and at least one vinylaromatic compound, e.g. Styrene, polymerized in the presence of a solvent-stabilized transition metal complex with weakly coordinating anions as a polymerization catalyst. In addition, the invention relates to copolymers of isobutene and at least one vinyl aromatic compound which are obtainable by the process according to the invention and which are preferably highly reactive, as well as certain functionalization products thereof.

Highly reactive copolymers of isobutene and at least one vinylaromatic compound are understood as meaning those copolymers which contain a high content of terminal ethylenic double bonds. In the context of the present invention, highly reactive copolymers of isobutene and at least one vinylaromatic compound are to be understood as meaning copolymers which have a proportion of vinylidene double bonds (α-double bonds) of at least 60 mol%, preferably of at least 70 mol% in particular of at least 80 mol%, based on the copolymer macromolecules. For the purposes of the present invention, vinylidene groups are understood to mean those double bonds whose position in the copolymer macromolecule is represented by the general formula

polymer

is described, i. the double bond is in the polymer chain in the α position. "Polymer" stands for the truncated to an isobutene copolymer residue. The vinylidene groups show the highest reactivity, whereas a double bond further inside the macromolecules shows no or definitely lower reactivity in functionalization reactions.

Isobutene-styrene copolymers and in particular isobutene-styrene block copolymers have both thermoplastic and elastic properties, are more tear-resistant and have a higher surface hardness than pure polyisobutene. Due to the The sen- sity of copolymerized styrene and in particular of styrene blocks, they show thermoplastic behavior and are therefore easy to process, for example by melt extrusion. They are therefore suitable for use in films, sealing materials, adhesives, adhesion promoters and the like.

Methods for producing isobutene-styrene block copolymers are known. In general, the polymerization is carried out in such a way that initially isobutene is polymerized under cationic conditions and the polymer chain formed is then further reacted with styrene.

US 4,946,899 describes a process for preparing isobutene-styrene diblock copolymers, triblock copolymers or styrenic copolymers by living cationic polymerization of isobutene to a living polyisobutene chain, which is then further polymerized with styrene in the presence of an electron-pair donor.

WO 01/10969 describes linear or star-shaped isobutene-styrene block copolymers having a central isobutene block which are obtainable by polymerizing isobutene in the presence of an at least difunctional initiator molecule and a Lewis acid under the conditions of a living cationic polymerization and then carrying the living chain ends with Styrene can continue to react.

By these prior art processes, copolymers are formed which are terminated at their chain ends by groups derived from styrene. A disadvantage of such chain ends, however, is that they can not be easily functionalized. For many applications, however, it is necessary to be able to further functionalize the chain ends, for example by the introduction of polar groups.

Another disadvantage of the prior art processes is that they require low temperatures, usually well below 0 ^° C.

EP-A 1344785 describes a process for the preparation of highly reactive polyisobutohomo- or copolymers using a solvent-stabilized transition metal complex with weakly coordinating anions as the polymerization catalyst. The polymerization can also be carries out at reaction temperatures above 0 ⁰ C carried, however, is disadvantageous in that the polymerization times are very long. Specifically described is the copolymerization of isobutene and isoprene. The preparation of highly reactive copolymers of isobutene and at least one vinyl aromatic compound, however, is not mentioned. The object of the present invention was to provide a process for the preparation of copolymers of isobutene and at least one vinylaromatic compound which does not have the abovementioned disadvantages of the processes of the prior art.

The object is achieved by a process for the preparation of copolymers which are composed of monomers comprising isobutene and at least one vinylaromatic compound, characterized in that isobutene or an isobutene-containing hydrocarbon mixture and at least one vinylaromatic compound in the presence of a catalyst of the formula I

wherein

M represents a transition metal of group 3 to 12 of the periodic table, a lanthanide or a metal of group 2 or 13 of the periodic table;

L stands for a solvent molecule;

Z represents a singly or multiply charged ligand;

A- represents a weak or non-coordinating anion;

a is an integer greater than or equal to 1;

b is 0 or an integer greater than or equal to 1;

wherein the sum of a and b is 4 to 8; and

m is an integer from 1 to 6,

polymerized.

The following information on suitable and preferred embodiments of the subject invention objects, in particular to the monomers and catalysts used in the process according to the invention, to the Reacti- onsbedingungen and the polymers obtainable with it apply both alone and in particular in combination with each other.

In the context of the present invention, the following definitions apply to generically defined radicals:

Ci-C4-alkyl is a linear or branched alkyl radical having 1 to 4 carbon atoms. Examples of these are methyl, ethyl, n-propyl, isopropyl, n-butyl, 2-butyl, isobutyl or tert-butyl. Ci-C2-alkyl is methyl or ethyl, Ci-C3-alkyl is also n-propyl or isopropyl.

Ci-Cβ-alkyl is a linear or branched alkyl radical having 1 to 8 carbon atoms. Examples of these are the abovementioned C 1 -C 4 -alkyl radicals and furthermore pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, 1-ethylpropyl, hexyl, 1, 1-dimethylpropyl, 1, 2 Dimethylpropyl, 1-methylpentyl, 2-methylpentyl, 3

Methylpentyl, 4-methylpentyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 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, heptyl, octyl and their constitution isomers such as 2-ethylhexyl.

Ci-C4-haloalkyl is a linear or branched alkyl radical having 1 to 4 carbon atoms, which is substituted by at least one halogen radical. Examples of these are CH ₂ F, CHF ₂ , CF ₃ , CH ₂ Cl, CHCl ₂ , CCI ₃ , CH ₂ FCH ₂ , CHF ₂ CH ₂ , CF ₃ CH ₂ and the like.

Aryl in the context of the present invention represents optionally substituted phenyl, optionally substituted naphthyl, optionally substituted anthracycenyl or optionally substituted phenanthrenyl. The aryl radicals may carry 1 to 5 substituents which are selected, for example, from hydroxy, C 1 -C ₈ -alkyl, C 1 -C 6 -haloalkyl, halogen, NO ₂ or phenyl. Examples of aryl are phenyl, naphthyl, biphenyl, anthracenyl, phenanthrenyl, ToIyI, nitrophenyl, hydroxyphenyl, chlorophenyl, dichlorophenyl, pentafluorophenyl, pentachlorophenyl, (trifluoromethyl) phenyl, bis (trifluoromethyl) phenyl, (trichloro) methylphenyl, bis (trichloromethyl) phenyl and hydroxynaphthyl.

Arylalkyl in the context of the present invention is an aryl group which is bonded via an alkylene group. Examples of these are benzyl and 2-phenylethyl. C 1 -C 4 -carboxylic acids are aliphatic carboxylic acids having 1 to 4 carbon atoms. Examples of these are formic acid, acetic acid, propionic acid, butyric acid and isobutyric acid.

Ci-C ₄ -AlkOhOl is a Ci-C4-alkyl radical as defined above, in which at least one hydrogen atom is replaced by a hydroxy group. Preferably, it is a monohydric alcohol, ie, a Ci-C4-alkyl group in which a hydrogen atom is replaced by a hydroxy group. Examples of these are methanol, ethanol, propanol, isopropanol, n-butanol, sec-butanol, isobutanol and tert-butanol.

Halogen in the context of the present invention is fluorine, chlorine, bromine or iodine.

Vinylaromatic compounds in the context of the present invention are styrene and styrene derivatives, such as α-methylstyrene, C 1 -C ₄ -alkylstyrenes, such as 2-, 3- or 4-methylstyrene and 4-tert-butylstyrene, and halostyrenes, such as 2-, 3- or 4-chlorostyrene. Preferred vinylaromatic compounds are styrene and 4-methylstyrene and mixtures thereof, with styrene being particularly preferred.

Transition metals of group 3 to 12 are also known as metals of the I. to VIII. Subgroup or are simply referred to as transition metals.

Examples of suitable transition metals are titanium, zirconium, vanadium, chromium, molybdenum, tungsten, manganese, iron, ruthenium, osmium, cobalt, rhodium, nickel, palladium, platinum, copper and zinc. Preferred transition metals are vanadium, chromium, molybdenum, manganese, iron, cobalt, nickel, copper and zinc, with manganese being particularly preferred.

Lanthanides are understood as meaning metals with the atomic number 58 to 71 in the periodic table, such as cerium, praseodymium, neodymium, samarium and the like. Preferred lanthanides are cerium and samarium.

The metals of group 2 or 13 of the periodic table are also referred to as metals of the 2nd or 3rd main group. Examples include beryllium, magnesium, calcium, aluminum and gallium. Preferred main group metals are magnesium and aluminum.

When M is a transition metal of Group 3 to 12 of the Periodic Table, it is preferably selected from vanadium, chromium, molybdenum, manganese, iron, cobalt, nickel, copper and zinc. When M is a lanthanide, it is preferably selected from cerium and samarium.

When M is a metal of group 2 or 13 of the periodic table, it is preferably selected from magnesium and aluminum.

M is particularly preferably a transition metal of group 3 to 12 of the Periodic Table. More preferably, M is a transition metal selected from vanadium, chromium, molybdenum, manganese, iron, cobalt, nickel, copper and zinc. In particular, M is manganese.

In the catalyst of the formula I, the central metal M can assume an oxidation number of I to VII. Preferably, M is present in an oxidation number of II, III or IV, more preferably of Il or IM and in particular of Il.

L is a solvent molecule, d. H. for a solvent molecule that can coordinate coordinate. These are molecules that are commonly used as solvents, but at the same time via at least one dative grouping, e.g. have a lone pair of electrons that can form a coordinative bond to the central metal. Examples of these are nitriles, such as acetonitrile, propionitrile and benzonitrile, open-chain and cyclic ethers, such as diethyl ether, dipropyl ether, diisopropyl ether, methyl tert-butyl ether, ethyl tert-butyl ether, tetrahydrofuran and dioxane, carboxylic acids, especially C 1 -C 4 Carboxylic acids, such as formic acid, acetic acid, propionic acid, butyric acid and isobutyric acid, carboxylic acid esters, especially the esters of Ci- C4 carboxylic acids with Ci-C4-Akoholen, such as ethyl acetate and propyl acetate, and Carbansäureannide, especially of Ci-C4-carboxylic acids with di- (C 1 -C 4 -alkyl) -amines, such as dimethylformamide.

Preferred solvent molecules are those which on the one hand bind coordinatively to the central metal, but on the other hand do not represent strong Lewis bases, so that they can easily be displaced from the coordination sphere of the central metal in the course of the polymerization. Preferably, the solvent ligands L, which may be the same or different, are selected from nitriles of the formula N≡CR ¹ , wherein R ^{1 is} C ¹ -C 6 -alkyl or aryl, and open-chain and cyclic ethers.

In the nitriles, the radical R ^{1 is} preferably C ¹ -C ⁴ -alkyl or phenyl. Examples of such nitriles are acetonitrile, propionitrile, butyronitrile, pentylnitrile and benzonitrile. Particularly preferably, R ^{1 is} methyl, ethyl or phenyl, ie the nitrile is particularly It is preferably selected from acetonitrile, propionitrile and benzonitrile. In particular, R ^{1 is} methyl or phenyl, ie the nitrile is in particular acetonitrile or benzonitrile. Specifically, R ^{1 is} methyl, ie the nitrile is especially acetonitrile.

Suitable open-chain and cyclic ethers are, for example, diethyl ether, dipropyl ether, diisopropyl ether, methyl tert-butyl ether, ethyl tert-butyl ether, tetrahydrofuran and dioxane, with diethyl ether and tetrahydrofuran being preferred.

L particularly preferably represents a nitrile of the formula N≡CR ¹ , in which R ^{1 is} preferably methyl, ethyl or phenyl, more preferably methyl or phenyl and in particular methyl.

L can stand for the same or different solvent molecules. However, in compound I, all L are preferably the same solvent ligands.

Z is derived from a single or multiple charged anion and thus differs from the ligand L mainly by the charge and also by the stronger coordination to the central metal M.

Z can represent both a charged monodentate and a mono- or poly-charged bidentate or multidentate ligand.

Examples of charged monodentate ligands are halides, pseudohalides, hydroxy, nitrite (NO 2), alcoholates and acid anions.

Examples of mono- or polysubstituted bidentate or polydentate ligands are di- and polycarboxylic acid anions, acetylacetonate and ethylenediaminetetraacetate (EDTA).

Halides are, for example, fluoride, chloride, bromide and iodide, with chloride and bromide being preferred. Most preferably halide is chloride.

Pseudohalides are, for example, cyanide (CN), thiocyanate (SCN), cyanate (OCN), isocyanate (CNO) and azide (N ₃ ). Preferred pseudohalides are cyanide and thiocyanate.

Suitable alkoxides are compounds of the formula RO ", in which R is C 1 -C -alkyl or arylalkyl Preferably R is C 1 -C ₄ -alkyl or benzyl Examples of such alcoholates are methylate, ethylate, propylate, isopropylate, n-butylate , Isobutylate, tert-butylate and benzyl alcoholate. Suitable acid anions are the acid anions of aliphatic or aromatic monocarboxylic acids having 1 to 8 carbon atoms, such as formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, caproic acid, caprylic acid and benzoic acid.

Suitable dicarboxylic acid anions are the mono- and dianions of aliphatic or aromatic dicarboxylic acids having 2 to 10 carbon atoms, such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid and phthalic acid.

Suitable polycarboxylic anions are the mono- and polyanions of polycarboxylic acids, such as citric acid or else the oligomers of ethylenically unsaturated carboxylic acids, such as acrylic acid or methacrylic acid.

Preferably, Z is derived from a monodentate singly charged anion. More preferably, Z is derived from a halide or pseudohalide, and more preferably from a halide. In particular, Z is derived from chloride.

The meaning of the index b depends on whether the ligand Z is a monodentate or a multidentate ligand. When Z stands for a bidentate or polydentate ligand, the subscript b stands for the number of binding sites with which this ligand Z coordinates to the metal multiplied by the number of these bidentate or polydentate ligands coordinated to M. For monodentate ligands Z, b is of course only the number of coordinatively bound ligands.

The coordination number of the metal, i. the sum of a and b is 4 to 8 according to the invention. It is necessary for at least one ligand L to be present in the coordination sphere of the metal.

a is preferably an integer from 1 to 6, more preferably an integer from 4 to 6, in particular 5 or 6 and especially 6.

b is preferably 0 or an integer from 1 to 4, more preferably 0 or 1 and especially 0. The sum of a and b is preferably 4 to 6. Particularly preferably, it is 6. In this case, the metal complexes are preferably in octahedral or almost octahedral form.

m is preferably an integer from 1 to 3. Specifically, m is 2.

A- represents a weak or non-coordinating anion. Weak or non-coordinating anions are those that do not form a coordinative bond with the central atom, ie that do not possess a Lewis basic grouping. Generally, weak or noncoordinating anions are those whose delocalized charge is delocalized over a large area of non-nucleophilic and chemically robust groups. For example, weakly or non-coordinating anions are mononuclear or dinuclear anions with a Lewis acidic central atom, but whose electron deficiency is compensated by the attachment of a weakly coordinating substituent.

Preferably, the weak or non-coordinating anion A- is selected from BX ₄ , B (Ar) ₄ , bridged anions of the formula [(Ar) ₃ B- (μ-Y) -B (Ar) ₃ ] -, SbX ₆ -, Sb ₂ Xn ^" , AsX ₆ -, As ₂ Xn, ReX ₆ -, Re ₂ Xn ^" , AIX ₄ -, Al ₂ X ₇ -, OTeX ₅ ^" , B (OTeXs) ₄ ^" , Nb (OTeXs) ₆ ^" , [Zn (OTeX ₅ ) ₄ ] ₂ ^" , OSeX ₅ ^" , trifluoromethanesulfonate, perchlorate, carborates and carbon cluster anions, wherein

Ar is phenyl which may bear 1 to 5 substituents selected from halogen, Ci-C ₄ alkyl and _{Ci-C4-haloalkyl;}

Y stands for a bridging group; and

X is fluorine or chlorine.

Ar is, for example, phenyl, pentafluorophenyl or bis (trifluoromethyl) phenyl, for example 3,5-bis (trifluoromethyl) phenyl. Ar in the anion B (Ar) ₄ preferably represents a substituted phenyl, particularly preferably bis (trifluoromethyl) phenyl, for example 3,5-bis (trifluoromethyl) phenyl, or in particular pentafluorophenyl. Also in the bridged anions Ar preferably represents a substituted phenyl group, particularly preferably bis (trifluoromethyl) phenyl, for example 3,5-bis (trifluoromethyl) phenyl, or in particular pentafluorophenyl.

The bridging group Y may be, for example, CN, NH ₂ or a cyclic bridging unit. Cyclic bridging units are those Cyclen, which are bound via two Lewis basic groups. Examples thereof are saturated or unsaturated heterocycles having at least 2 heteroatoms, preferably having at least 2 N atoms, such as pyrazolediyl, pyrazolinediyl, pyrazolidinediyl, imidazolediyl, imidazolinediyl, imidazolidinediyl, triazolediyl, triazolinediyl, triazolidinediyl, pyrimidinediyl, pyrazinediyl and pyridazinediyl. Aromatic heterocycles are preferred. Particularly preferred cyclic bridging units are imidazol-1,3-yl and triazolediyl, eg [1,2,4] triazole-2,4-diyl.

Y is preferably selected from cyclic bridging groups, triazolediyl and in particular imidazol-1,3-yl being particularly preferred.

X is preferably fluorine.

Carborates in the context of the present invention are understood as meaning the anions of carboranes, ie of cage-like boron-carbon compounds, for example the anions of closo, nido or arachno-carboranes. Examples of these are the following closo-carborates: [CBnHi ₂ ] -, [CB9H10] ^" and [CBn (CH ₃ ) I ₂ ] -. However, preference is given to those carborates in which a part of the hydrogen atoms is substituted by halogen atoms. Examples of these are [CBnHeCIe], [1-H-CBiI (CH ₃ ) SCI ₆ ], [CBnH ₆ F ₆ ] and [1-H-CBn (CHs) ₅ F ₆ ] -.

In the context of the present invention, carbon cluster anions are understood as meaning the anions of carbon clusters, for example fullerenes. An example of this is C ₆ o.

Particularly preferred is the weak or non-coordinating anion A- selected from BX ₄ -, B (Ar) ₄ -, bridged anions of the formula [(Ar) 3B- (μ -Y) -B (Ar) ₃ ] -, SbX ₆ -, Sb ₂ Xn ^" , AsX ₆ -, As ₂ Xn-, ReX ₆ -, Re ₂ Xn ^" , AIX ₄ -, Al ₂ X ₇ -, OTeX ₅ ^" , B (OTeXs) ₄ -, Nb (OTeXs) ₆ ^" , [Zn (OTeX ₅ ) ₄ ] ₂ ^" , OSeX ₅ ^" , trifluoromethanesulfonate and perchlorate.

More preferred weakly or non-coordinating anions A ^" are selected from B (Ar) ₄ - and bridged anions of the formula [(Ar) 3B- (μ-Y) -B (Ar) ₃ ] -. Preferred are borates B ( Ar) ₄ - in which Ar is 3,5-bis (trifluoromethyl) phenyl or in particular pentafluorophenyl Preferred bridged anions are those in which Ar is pentafluorophenyl and Y is an imidazole-1,3-bridge.

Particularly preferred catalysts of the formula I are those in which M is V, Cr, Mo, Mn, Fe, Co, Ni or Zn and in particular Mo, Mn, Fe, Ni or Cu, L is acetonitrile (CH 3 CN) or benzonitrile (C ₆ HsCN) and especially for acetonitrile, X is chloride, a is 5 or 6, b is 0 or 1, the sum of a and b is 6 where m is 1 or 2 and A- is B (Ar) ₄ ^" or a bridged anion of the formula [(Ar) ₃ B- (μ-Y) -B (Ar) ₃ ] - in the case of the catalyst I, [Mo (CH ₃ CN) ₅ Cl] 2 ⁺ 2 [A] or especially [Mn (CH ₃ CN) ₆ ] 2 ⁺ 2 [A], where A- is B (Ar) ₄ - wherein Ar is 3,5-bis (trifluoromethyl) phenyl or in particular pentafluorophenyl, or wherein A- is a bridged anion of the formula [(Ar) ₃ B- (μ-Y) -B (Ar) ₃ ] - in which Ar is pentafluorophenyl and Y is an imidazole-1,3-bridge.

The catalysts of the formula I can be prepared by generally known processes for the preparation of transition metal complexes with solvent molecules in the coordination sphere. The introduction of the weakly or non-coordinating anion A- can be carried out analogously to known processes, as described, for example, in W.E. Buschmann, J.S. Miller, Chem. Eur. J. 1998, 4 (9), 1731, R.E. LaPointe, G.R. Ruft, K.A. Abboud, J. Klosin, New Family of Weakly Coordinating Anions, J. Am. Chem. Soc. 2000, 122 (39), 9560, W.E. Buschmann, J.S. Miller, Inorganic Chemistry 33, 2002, 83, O. Nuyken, F.E. Kühn, Angew. Chem. Int. Ed. Engl. 2003, 42, 1307, O. Nuyken, F.E. Kühn, Chem. Eur. J. 2004, 10, 6323 and EP-A-1344785 and in the literature cited therein, to which reference is hereby made in its entirety.

Thus, for example, the catalyst of the formula I can be prepared by dissolving a salt of the formula M ^{x +} Z ^y -χ / _y in a solvent which corresponds to the solvent molecule L. In the event that Z is not Cl, or instead of a salt of formula M ^{X +} (CI) _{X is} added. Then, this solution for the introduction of the anion A- with a silver salt of the corresponding anion, in particular with [Ag (L) ₄ J ⁺ (A), preferably at a temperature of -10 ⁰ C to room temperature, is added. The thereby precipitating silver chloride is separated from the reaction solution, for example by filtration, decantation or centrifugation. Subsequently, the solvent is usually at least partially removed, which can be done for example by distillation, in particular under reduced pressure. The isolation of the catalyst I can be carried out by conventional methods, for example by removing the solvent to dryness or preferably by crystallization in suitable solvents.

Alternatively, one can subject isolated mono- or polynuclear complexes of metal M with Z and L as ligands of the above-described ion exchange method for the introduction of the anion A-. The preparation of such isolatable solvent complexes can be carried out in analogy to processes, as described, for example, in FA Cotton, RH Niswander, JC Sekutowski, Inorg. Chem. 1979, 18, 1149, 1st R. Anderson, JC Sheldon, Aust. J. Chem. 1965, 18, 271, JV Brencic, FA Cotton, Inorg. Chem. 1969, 8, 7 and RW McGaff, NC Dopke, RK Hayashi, DR Powell, PM Treichel, Polyhedron 2000, 19, 1245 and in the literature cited therein, which is hereby incorporated by reference in its entirety.

In the process according to the invention, the catalysts of the formula I are, in relation to the monomers used, in the molar ratio of 1:10 to 1: 1,000,000, more preferably from 1: 5,000 to 1: 500,000 and in particular from 1: 5000 to 1: 100,000, eg from 1: 10,000 to 1: 100,000.

The concentration of the catalysts I used in the reaction mixture is in the range of preferably 0.01 mmol / l to 5 mmol / l, more preferably 0.01 to 1 mmol / l, more preferably 0.01 to 0.5 mmol / l and in particular 0.01 to 0.1 mmol / l.

Raffinates, C ₄ cuts from the dehydrogenation of isobutane or C ₄ cuts from Steamcra- CKEM and out - isobutene sources are both isobutene-containing isobutene C4 hydrocarbon streams, such as C ₄ is itself and isobutene-containing hydrocarbon mixtures, eg FCC (fluid catalysed cracking) crackers, provided that they are largely freed from 1,3-butadiene contained therein. Suitable C ₄ hydrocarbon streams generally contain less than 500 ppm, preferably less than 200 ppm, butadiene. The presence of 1-butene and of cis- and trans-2-butene is largely uncritical. Typically, the isobutene concentration in the C ₄ hydrocarbon streams is in the range of 40 to 60% by weight. The isobutene-containing monomer mixture may contain small amounts of contaminants, such as water, carboxylic acids or mineral acids, without resulting in critical yield or selectivity losses. It is expedient to avoid an accumulation of these impurities by removing such pollutants from the isobutene-containing monomer mixture, for example by adsorption on solid adsorbents, such as activated carbon, molecular sieves or ion exchangers.

The vinylaromatic compounds are used in the process according to the invention in an amount of preferably from 5 to 95% by weight, particularly preferably from 30 to 70% by weight, based on the total weight of vinylaromatic compounds and isobutene.

In the process according to the invention, it is also possible to polymerize monomer mixtures which, in addition to isobutene or the isobutene-containing hydrocarbon mixture and the at least one vinylaromatic compound, also contain further olefinically unsaturated comonomers which are copolymerizable with isobutene and the vinylaromatic compound. If monomer mixtures with further comonomers are to be used in the process according to the invention, these como monomers in an amount of preferably at most 15 wt .-%, more preferably at most 10 wt .-% and in particular at most 5 wt .-%, based on the total weight of the monomer mixture.

Suitable copolymerizable monomers are isoolefins having 5 to 10 C atoms, such as 2-methylbutene-1, 2-methylpentene-1, 2-methylhexene-1, 2-ethylpentene-1, 2-ethylhexene-1 and 2-propylheptene-1 , Also suitable as comonomers are olefins which have a silyl group, such as 1-trimethoxysilylethene, i- (trimethoxysilyl) propene, 1- (trimethoxysilyl) -2-methylpropene-2, 1- [tri (methoxyethoxy) silyl] ethene, 1 - [tri (methoxyethoxy) silyl] propene, and 1- [tri (methoxyethoxy) silyl] -2-methylpropene-2.

As a rule, processes for the copolymerization of various comonomers can be designed such that preferably random polymers or preferably block copolymers are formed. The preparation of block copolymers is generally carried out by feeding the various monomers successively to the polymerization reaction, the second comonomer being added in particular only when the first comonomer has already been at least partially polymerized. In this way, it is possible to access both diblock, triblock and higher block copolymers which, depending on the order of monomer addition, have a block of one or the other comonomer as the terminal block. In this way, the process according to the invention makes available block copolymers which have either a polyisobutene block or a block of the vinylaromatic compound as the terminal block. Isobutene is preferably added as the last monomer during the successive addition of the monomers, so that block copolymers with a terminal polyisobutene block are formed. Surprisingly, however, block copolymers which generally have a terminal polyisobutene block are also formed in the process according to the invention if all the comonomers are simultaneously fed to the polymerization reaction. This is because the vinyl aromatic compound, especially styrene, polymerizes significantly faster than isobutene.

The polymerization can be carried out both continuously and discontinuously. Continuous processes can be carried out in analogy to known prior art processes for the continuous polymerization of isobutene in the presence of liquid phase Lewis acid catalysts.

The inventive method is suitable both for carrying out at low temperatures, for example at -78 to 0 ⁰ C, and at higher temperatures, ie at least 0 ⁰ C, for example at 0 to 100 ⁰ C, suitable. The polymerization is mainly for economic reasons, preferably at least 0 ⁰ C, for example at 0 to 100 ⁰ C special ders preferably carried out at 20 to 60 ⁰ C to keep the energy and material consumption required for cooling as low as possible. However, it can just as well at lower temperatures, for example at -78 to <0 ⁰ C, preferably at -40 to -10 ⁰ C, are performed.

If the polymerization is carried out at or above the boiling point of isobutene, it is preferably carried out in pressure vessels, for example in autoclaves or in pressure reactors.

Preferably, the polymerization is carried out 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 usually occurs during the polymerization reaction to such an extent that the removal of the heat of reaction formed can be ensured. Suitable diluents are those solvents or solvent mixtures which are inert to the reagents used. Suitable diluents are, for example, aliphatic hydrocarbons, such as butane, pentane, hexane, heptane, octane and isooctane, cycloaliphatic hydrocarbons, such as cyclopentane and cyclohexane, aromatic hydrocarbons, such as benzene, toluene and the xylenes, and halogenated hydrocarbons, such as methyl chloride, dichloromethane and Trichloromethane, and mixtures of the aforementioned diluents. Preference is given to using at least one halogenated hydrocarbon, optionally in admixture with at least one of the abovementioned aliphatic or aromatic hydrocarbons. In particular, dichloromethane is used. Before use, the diluents are preferably freed from 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.

The polymerization is preferably carried out under largely aprotic, in particular under anhydrous, reaction conditions. Aprotic or anhydrous reaction conditions are understood to mean that the water content (or the content of protic impurities) in the reaction mixture is less than 50 ppm and in particular less than 5 ppm. As a rule, therefore, the feedstocks will be dried physically and / or by chemical means before being used. In particular, it has proven useful to use the aliphatic or alicyclic hydrocarbons used as solvent after conventional prepurification and predrying with an organometallic compound, such as an organolithium, organomagnesium or organoaluminum compound, in an amount sufficient to remove the traces of water to remove from the solvent. The solvent thus treated is then preferably condensed directly into the reaction vessel. Similarly, one can also proceed with the monomers to be polymerized, in particular with isobutene or with the isobutene-containing 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, which are not suitable for drying with metals, such as sodium or potassium, or with metal alkyls, are freed of water (traces) with suitable drying agents, for example with calcium chloride, phosphorus pentoxide or molecular sieves. In an analogous manner, it is also possible to dry the vinylaromatic monomers and also other starting materials for which treatment with metal alkyls is likewise not considered.

Polymerization of the monomers occurs spontaneously upon mixing of the initiator system (i.e., Catalyst I) with at least one of the monomers at the desired reaction temperature. In this case, one can proceed by initially introducing the monomers, if appropriate in the solvent, and then adding the catalyst I. The adjustment of the reaction temperature can be carried out before or after the catalyst addition. It is also possible to initially introduce only one of the monomers, if appropriate in the solvent, then to add the catalyst I and only after a certain time, e.g. when at least 60%, at least 80% or at least 90% of the monomer is reacted, the one or more monomers are added. Alternatively, you can submit the catalyst I, optionally in the solvent, then add the monomers simultaneously or sequentially and then set the desired reaction temperature. The beginning of polymerization is that time at which the catalyst and at least one of the monomers are contained in the reaction vessel.

In addition to the discontinuous procedure described here, the polymerization can also be designed as a continuous process. This leads to the starting materials, i. the monomers to be polymerized, optionally the solvent and the catalyst of the polymerization reaction continuously and removes continuously reaction product, so that set in the reactor more or less stationary polymerization. The monomers to be polymerized can be supplied as such, diluted with a solvent or as a monomer-containing hydrocarbon stream.

To terminate the reaction, the reaction mixture is preferably deactivated, for example by adding a protic compound, in particular by adding water, alcohols, such as methanol, ethanol, n-propanol and isopropanol or their Mixtures with water, or by adding an aqueous base, for example an aqueous solution of an alkali or alkaline earth metal hydroxide, such as sodium hydroxide, potassium hydroxide, magnesium hydroxide or calcium hydroxide, an alkali or Erdalkalicarbonats, such as sodium, potassium, magnesium or calcium carbonate, or a Alkali or alkaline earth bicarbonates, such as sodium, potassium, magnesium or calcium bicarbonate.

In a preferred embodiment, the process according to the invention serves to prepare copolymers of monomers comprising isobutene or an isobutene-containing hydrocarbon mixture and at least one vinylaromatic compound having a content of terminal vinylidene double bonds (α-double bonds) of at least 50 mol%. The process according to the invention particularly preferably serves for the preparation of highly reactive copolymers having a content of terminal vinylidene double bonds of at least 60 mol%, preferably of at least 70 mol%, more preferably of at least 80 mol%, more preferably of at least 85 mol% % and in particular of at least 90 mol%, eg of at least 95 mol% or about 100 mol%. Preferably, the copolymer is an isobutene-styrene copolymer.

Preferably, the copolymer is a block copolymer comprising at least one isobutene block and at least one block of vinyl aromatic compounds, wherein the block of vinyl aromatic compounds is preferably a styrene block. The process according to the invention can be designed to give copolymers which can be used as terminal, i. recently formed blocks, either polyisobutene blocks or blocks derived from the vinyl aromatic compound. However, the process according to the invention preferably serves to prepare copolymers having a terminal polyisobutene block. More preferably, the block copolymer is a diblock copolymer made up of a polyisobutene block and a vinyl aromatic block, the terminal block preferably being a polyisobutene block. Most preferably, the block of vinyl aromatic compounds is a styrene block.

Preferably, the copolymers prepared by the process according to the invention have a number average molecular weight M _n of 500 to 1,000,000. By choosing the appropriate reaction conditions, the process according to the invention can be designed in such a way that, depending on the intended use of the polymers, it is preferable to obtain copolymers having a higher molecular weight or, preferably, copolymers having a lower molecular weight. The variation of the reaction phase required to produce copolymers of a certain molecular weight parameter is basically known to the person skilled in the art. If the copolymers prepared by the process according to the invention are to be used, for example, as thermoplastics, they have a number-average molecular weight M _n of preferably from 10,000 to 1,000,000, more preferably from 50,000 to 1,000,000 and in particular from 50,000 to 500,000. If the copolymers prepared by the process according to the invention are to be subjected, for example, to the functionalization reactions described below, they have a number average molecular weight M _n of preferably 500 to 250,000, particularly preferably 500 to 100,000, more preferably 500 to 80,000 and in particular 1000 to 60,000.

The process according to the invention can be successfully carried out not only at temperatures of at least 0 ^° C., but it can moreover be easily designed such that preferably highly reactive copolymers, more preferably highly reactive block copolymers, are formed.

Preferably, for a monomer conversion of at least 80%, a polymerization time of at most 2 hours, more preferably of at most one hour is required.

Another object of the present invention is a copolymer composed of monomers comprising isobutene and at least one vinyl aromatic compound obtainable by the polymerization process according to the invention. Preferably, the copolymers according to the invention have a content of terminal vinylidene double bonds (α-double bonds) of at least 50 mol%. Most preferably, the copolymers of the present invention are highly reactive, i. they have a high content of terminal vinylidene double bonds (α-double bonds), e.g. of at least 60 mole%, preferably of at least 70 mole%, more preferably of at least 80 mole%, more preferably at least 85 mole% and especially of at least 90 mole%, e.g. of at least 95 mole%, or about 100 mole%.

The vinylaromatic compound is preferably styrene or 4-methylstyrene and particularly preferably styrene. Accordingly, particularly preferred copolymers are isobutene-styrene copolymers.

In the copolymer according to the invention, the total amount of copolymerized vinylaromatic compound, based on the total weight of the polymer, is preferably from 5 to 95% by weight and more preferably from 30 to 70% by weight. The copolymer according to the invention is preferably a block copolymer, for example a diblock, triblock or a higher block copolymer comprising at least one polyisobutene block and at least one block of vinylaromatic compounds, the block consisting of vinylaromatic compounds preferably is a styrene block. In this case, the polyisobutene block preferably represents the terminal block, ie the block formed last. More preferably, the block copolymer is a diblock copolymer which is made up of a polyisobutene block and a vinylaromatic block, the terminal block preferably being a polyisobutene block. Most preferably, the block of vinyl aromatic compounds is a styrene block.

Preferably, the copolymers according to the invention have a number average molecular weight M _n of preferably 500 to 1,000,000. Depending on the intended use, the copolymers according to the invention preferably have a higher molecular weight or, preferably, a lower molecular weight. If the copolymers according to the invention are to be used, for example, as thermoplastics, they have a number-average molecular weight M _n of preferably from 10,000 to 1,000,000, particularly preferably from 50,000 to 1,000,000 and in particular from 50,000 to 500,000. If the copolymers according to the invention are to be subjected, for example, to the functionalization reactions described below, they have a number average molecular weight M _n of preferably 500 to 250,000, particularly preferably 500 to 100,000, more preferably 500 to 80,000 and in particular 1000 to 60,000.

The information given in the context of the invention for weight-average and number-average molecular weights M _w and M _n and their quotient PDI (PDI = M _w / M _n ) refer to values which were determined by means of gel permeation chromatography. The proportion of terminal ethylenic double bonds was determined by means of ¹ H-NMR.

Copolymers of the invention can be functionalized not only on the vinylidene-terminated chain ends analogously to highly reactive polyisobutenes in order to optimize them for a particular application, they also have thermoplastic and elastic properties. In particular, they or their functionalization products are suitable for use in films, sealing materials, adhesives, adhesion promoters, medical products, for example in the form of specific implants, in particular artery implants (stents), and compounds. The functionalization can be carried out analogously to derivatization reactions, as described, for example, in WO 03/074577 or in German patent application DE 102005002772.5, to which reference is hereby fully made.

Accordingly, another subject of the present invention is a functionalized copolymer which is made up of monomers comprising isobutene and at least one vinylaromatic compound, obtainable by subjecting a copolymer according to the invention to one of the following functionalization reactions:

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 Viii) hydroformylation and optionally hydrogenation or reductive amination of the product obtained, or ix) copolymerization with an olefinically unsaturated dicarboxylic acid or a derivative thereof.

i) hydrosilylation

For functionalization, a copolymer according to the invention can be subjected to a reaction with a silane in the presence of a silylation catalyst to give a copolymer 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 RhCb. Also suitable are RuCb and IrCb. Suitable catalysts are also Lewis acids such as AICb or TiCU and peroxides. It may be advantageous to use combinations or mixtures of the aforementioned catalysts. Suitable silanes include halogenated silanes such as trichlorosilane, methyldichlorosilane, dimethylchlorosilane and trimethylsiloxydichlorosilane; Alkoxysilanes such as methyldimethoxysilane, phenyldimethoxysilane, 1,3,3,5,5,7,7-heptanenethyl-1,1-dinethoxytetrasiloxane and trialkoxysilanes, e.g. B. trimethoxysilane and triethoxysilane, and acyloxysilanes. Preference is given to using trialkoxysilanes.

The reaction temperature in the silylation is preferably in a range from 0 to 10O ⁰ C, more preferably 40 to 12O ⁰ C. The reaction is usually carried out under atmospheric pressure, but can also at elevated pressures, such as in the range of about 1, 5 to 20 bar, or reduced pressures, such as 200 to 600 mbar done.

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 copolymer 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 copolymer 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 copolymers are obtained with thiol groups. The addition of hydrogen sulfide is preferably carried out at temperatures below 100 ⁰ 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, the Marckovnikov addition products to the double bond are generally obtained. Suitable initiators of the hydro-alkylthio addition are, for example, protic and Lewis acids, such as concentrated sulfuric acid or AICb, 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 , In the hydro-alkylthio addition in the presence of these initiators are usually the anti-Markovnikov- Obtained addition products. The reaction can furthermore be carried out in the presence of electromagnetic radiation having a wavelength of 10 to 400 nm, preferably 200 to 300 nm.

iii) Electrophilic substitution on aromatics

For derivatization, a copolymer of the invention may 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 are incorporated herein by reference becomes.

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 6 -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. These include, for example, AICI ₃ , AIBr ₃ , BF ₃ , BF ₃ ^* 2 C ₆ H ₅ OH, BF ₃

• [O (C ₂ H ₅ ) ₂ ], TiCl ₄ , SnCl ₄ , AIC ₂ H ₅ Cl ₂ , FeCl ₃ , SbCl ₅ and SbF ₅ . These alkylating 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, such as 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 catalyzed with protic acids such as sulfuric acid, phosphoric acid, methanesulfonic acid or trifluoromethanesulfonic acid. 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 -1O ⁰ C and + 100 ⁰ C. The reaction is usually carried out at atmospheric pressure, but can also be carried out at higher pressures (for example in the case of volatile solvents) or at lower pressures.

By suitable choice of the molar ratios of aromatic or heteroaromatic compound to the copolymer and the catalyst, the proportion of substituted products obtained and their degree of substitution can be adjusted. Monosubstituted phenols substantially substituted by the copolymer are generally obtained with an excess of phenol or in the presence of a Lewis acidic alkylation catalyst, if an additional ether is used as cocatalyst.

For further functionalization, the phenol-substituted copolymer 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, one containing the copolymer lymer alkylated and additionally at least partially aminoalkylated compound. It is also possible to use reaction and / or condensation products of aldehyde and / or amine. The preparation of such compounds is described in WO 01/25293 and WO 01/25294, to which reference is hereby fully made.

iv) epoxidation

For functionalization, a copolymer according to the invention can be reacted with at least one peroxide compound to give an at least partially epoxidized copolymer.

Suitable methods for epoxidation are described in J. March, Advanced Organic Chemistry, 4th Edition, John Wiley & Sons, pp. 826-829, to which reference is hereby made. At least one peracid, such as m-chloroperbenzoic acid, performic acid, peracetic acid, trifluoroperacetic acid, perbenzoic acid and 3,5-dinitroperbenzoic acid, is preferably used as the peroxide compound. 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 epoxidizing 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 is relatively stable and can then be reacted ring-opening with water, acids, alcohols, thiols or primary or secondary amines, using i.a. Diols, glycol ethers, glycol thioethers and amines. However, this functionalization route often proceeds with relatively low yields because of steric hindrance at the tertiary carbon atom of the epoxy group. On the other hand, if the epoxide is converted to the corresponding carbonyl compound, which can be done, for example, by means of zeolites or Lewis acids, then the carbonyl compounds formed can be derivatized with significantly better yields, for example by subjecting them to the reactions A) to C) described under ix).

The epoxide can also be converted to a 2- [copolymer] -1,3-propanediol by reaction with a borane and subsequent oxidative cleavage of the resulting ester. Suitable boranes are, for example, diborane (B2H6) and also alkyl and arylboranes RBH2 (R = alkyl or aryl). The reaction with the borane is suitably carried out in a borane-coordinating solvent. Examples of these are open-chain ethers, such as dialkyl, diaryl or alkylaryl ethers, and cyclic ethers, such as tetrahydrofuran. ran or 1, 4-dioxane. The oxidative cleavage to the 1, 3-diol can be carried out, for example, as described in v). The conversion of the epoxide into a 2- [copolymer] -1,3-propanediol is described, for example, in EP-A-0737662, to which reference is hereby made in its entirety.

v) hydroboration

For functionalization, it is possible to subject a copolymer according to the invention to a reaction with a (optionally generated in situ) borane to give an at least partially hydroxylated copolymer. Suitable hydroboration processes are described in J. March, Advanced Organic Chemistry, 4th Edition, John Wiley & Sons, pp. 783-789, which is hereby incorporated by reference. Suitable hydroboration reagents are, for example, diborane, which is generally generated in situ by reaction of sodium borohydride with BF3 etherate, disiamylborane (bis [3-methylbut-2-yl] borane), 1,1,2-trimethylpropylborane, 9-borbicyclo [3.3.1] nonane, diisocaphenylborane, which are obtainable by hydroboration of the corresponding alkenes with diborane, chloroborane-dimethylsulfide, alkyldichloroboranes or H3B-N (C2Hs) 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 generally determined by the reactivity of the hydroboration and is typically between the melting and boiling point of the reaction mixture, preferably in the range of from ⁰ ° C to 6O ⁰ 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 copolymer-substituted boranes formed are not isolated, but converted by subsequent reaction directly into the desired products. A very important implementation of the copolymer-substituted boranes is the reaction with alkaline hydrogen peroxide to give an alcohol which preferably corresponds formally to the anti-Markovnikov hydration of the copolymer. Further, the obtained copolymer-substituted boranes can be subjected to reaction with bromine in the presence of hydroxide ions to obtain the bromide. vi) ene reaction

For functionalization, a copolymer according to the invention with at least one alkene which has an electrophile-substituted double bond can be reacted in an ene reaction (see, for example, DE-A 4 319 672 or H. Mach and P. Rath in "Lubrication Science Il (1999), pp. 175-185, to which reference is made in full) In the En reaction, an alkene designated as En having an allyl-containing hydrogen atom is reacted with an electrophilic alkene, the so-called enophile, in a pericyclic amine A reaction comprising a carbon-carbon bond, a double-bond shift, and a hydrogen transfer reaction In the present case, the copolymer reacts as En Suitable enophiles are compounds which are also used as dienophiles in the Diels-Alder reaction This results in at least partially functionalized copolymers with succinic anhydride groups (succinic anhydride groups). Depending on the molecular weight and the double bond type of the copolymer used, the maleic anhydride concentration and the temperature 70 to 90% of the copolymer used are usually functionalized. If desired, the double bond newly formed in the copolymer chain can then be further functionalized, for example by reaction with maleic anhydride in a renewed ene reaction with attachment of a further succinic anhydride group.

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 succinic anhydride-derivatized copolymer to a subsequent reaction selected from:

a) reaction with at least one amine to give a copolymer which is at least partially functionalized with succinimide groups and / or succinamide groups,

b) reaction with at least one alcohol to give a copolymer which is at least partially functionalized with succinic ester groups, and c) reaction with at least one thiol to obtain a copolymer which is at least partially functionalized with succinine thioester groups.

vii) addition of halogen or hydrogen halides

For functionalization, a copolymer according to the invention can be subjected to a reaction with hydrogen halide or a halogen to give a copolymer 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, 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 and / or increased pressure 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, such as C0F3, XeF2 and mixtures of PbÜ2 and SF ₄ are used. Bromine usually adds at room temperature in good yields of double bonds. Chlorine-containing reagents, such as SO ₂ Cl ₂ , PCI _5, etc., can be used in addition to the free halogen.

If desired, the dihalides formed can be dehydrohalogenated, for example by thermal treatment, to give allyl halide-terminated copolymers.

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 minor extent addition products to the terminal double bond. viii) hydroformylation

For functionalization, the copolymer according to the invention can be subjected to a reaction with carbon monoxide and hydrogen in the presence of a hydroformylation catalyst to give an at least partially hydroformylated copolymer. It goes without saying that the reaction conditions are chosen so that the aromatic rings of the copolymerized vinylaromatic compounds are not changed.

Suitable hydroformylation catalysts are known and preferably comprise a compound or a complex of an element of Group VIII of the Periodic Table, such as Co, Rh, Ir, Ru, Pd or Pt. For influencing the activity and / or selectivity, hydroformylation catalysts modified with N- or P-containing ligands are preferably used. Suitable salts of these metals are, for example, the hydrides, halides, nitrates, sulfates, oxides, sulfides or the salts with alkyl or arylcarboxylic acids or alkyl or arylsulfonic acids. Suitable complex compounds have ligands selected, for example, from halides, amines, carboxylates, acetylacetonate, aryl or alkylsulfonates, hydride, CO, olefins, dienes, cycloolefins, nitriles, N-containing heterocycles, aromatics and heteroaromatics, ethers , PF3, phospholes, phosphabenzenes and mono-, bi- and multidentate phosphine, phosphinite, phosphonite, phosphoramidite and phosphite ligands.

In general, catalytically active species of the general formula H _x My (CO) ₂ Lq are formed under hydroformylation conditions from the particular catalysts or catalyst precursors used, where M is a metal of subgroup VIII, L is a ligand and q, x, y , z are integers, depending on the valence and type of metal and the ligand L's binding.

In a preferred embodiment, the hydroformylation catalysts are prepared in situ in the reactor used for the hydroformylation reaction.

Another preferred form is the use of a carbonyl generator in which prefabricated carbonyl z. B. adsorbed on activated carbon and only the desorbed carbonyl hydroformylation is supplied, but not the salt solutions from which the carbonyl is produced.

Suitable rhodium compounds or complexes are, for. Rhodium (II) and rhodium (III) salts, such as rhodium (III) chloride, rhodium (III) nitrate, rhodium (III) sulfate, potassium Rhodium sulfate, rhodium (II) or rhodium (III) carboxylate, rhodium (II) and rhodium (III) acetate, rhodium (III) oxide, salts of rhodium (III) acid, trisammonium hexachlororhodate (III) etc. Also suitable are rhodium complexes, such as rhodiumbiscarbonyl acetylacetonate, acetylacetonato-bis-ethyl rhodium (I), etc.

Also suitable are ruthenium salts or compounds. Suitable ruthenium salts are, for example, ruthenium (III) chloride, ruthenium (IV), ruthenium (VI) or ruthenium (VIII) oxide, alkali metal salts of ruthenium oxygen acids such as K 2 RUO ₄ or KRuO ₄ or complex compounds, such as. The metal carbonyls of ruthenium, such as trisruthenium dodecacarbonyl or hexaruthenium octadecacarbonyl, or mixed forms in which CO are partially replaced by ligands of the formula PR3, such as Ru (CO) 3 (PPh3) 2, can also be used. be used.

Suitable cobalt compounds are, for example, cobalt (II) chloride, cobalt (II) sulfate, cobalt (II) carbonate, cobalt (II) nitrate, their amine or hydrate complexes, cobalt carboxylates, such as cobalt formate, cobalt acetate, cobalt ethylhexanoate, cobalt naphthanoate, and cobalt -Caprolactamat complex. Here, too, the carbonyl complexes of the cobalt, such as dicobalt octacarbonyl, tetracobalt dodecacarbonyl and hexacobalt hexadecarbonyl, can be used.

The above and other suitable compounds are known in principle and in the

Literature sufficiently described.

Suitable activating agents which can be used for hydroformylation are, for. B. Bronsted acids, Lewis acids, such as. BF3, AICI3, ZnCb, and Lewis bases.

The composition of the synthesis gas used from carbon monoxide and hydrogen can vary within wide ranges. The molar ratio of carbon monoxide and hydrogen is generally about 5:95 to 95: 5, preferably about 40:60 to 60:40. The temperature in the hydroformylation is generally in a range of about 20 to 200 ⁰ C, preferably about 50 to 190 ⁰ C. The reaction is usually carried out at the partial pressure of the reaction gas at the selected reaction temperature. In general, the pressure is in a range of about 1 to 700 bar, preferably 1 to 300 bar.

The carbonyl number of the resulting hydroformylated copolymers depends on the number average molecular weight M _n . Preferably, the majority of the double bonds contained in the copolymer used according to the invention is converted by the hydroformylation in aldehydes. By using suitable hydroformylation catalysts and / or an excess of hydrogen in the synthesis gas used, the majority of the ethylenically unsaturated double bonds present in the educt can also be converted directly into alcohols. This can also be done in a two-stage functionalization according to the reaction step B) described below.

The functionalized copolymers obtained by hydroformylation are advantageously suitable as intermediates for further processing by functionalizing at least part of the aldehyde functions contained in them.

A) Oxocarboxylic acids

For further functionalization, the hydroformylated copolymers obtained in step viii) can be reacted with an oxidizing agent to give a copolymer which is at least partially functionalized with carboxy groups.

For the oxidation of aldehydes to carboxylic acids, it is generally possible to use a large number of different oxidizing agents and processes, which may be used, for example. In J. March, Advanced Organic Chemistry, John Wiley & Sons, 4th edition, p. 701ff. (1992). These include z. As the oxidation with permanganate, chromate, atmospheric oxygen, etc. The oxidation with air can be carried out both catalytically in the presence of metal salts and in the absence of catalysts. As metals are preferably used those which are capable of a valency change, such as. As Cu, Fe, Co, Mn, etc. The reaction usually succeeds even in the absence of a catalyst. In the case of air oxidation, the conversion can be easily controlled over the duration of the reaction.

According to a further embodiment, the oxidizing agent is an aqueous hydrogen peroxide solution in combination with a carboxylic acid, such as. As acetic acid used. The acid value of the resulting copolymers having carboxyl function depends on the number average molecular weight M _n .

B) Oxo alcohols

According to a further suitable embodiment, the hydroformylated copolymers obtained in step viii) can be reacted with hydrogen in the presence of a hydrogenation catalyst to give an at least partially functional with alcohol groups. be subjected to onalisierten copolymer. It goes without saying that the reaction conditions are chosen so that the aromatic rings of the copolymerized vinylaromatic compounds are not changed.

Suitable hydrogenation catalysts are generally transition metals such. As Cr, Mo, W, Fe, Rh, Co, Ni, Pd, Pt, Ru, etc., or mixtures thereof, to increase the activity and stability on carriers such. As activated carbon, alumina, diatomaceous earth, etc., can be applied. To increase the catalytic activity Fe, Co, and preferably Ni can also be used in the form of Raney catalysts as metal sponge with a very large surface area.

The hydrogenation of the oxo-aldehydes from stage viii) takes place, depending on the activity of the catalyst, preferably at elevated temperatures and elevated pressure. Preferably, the reaction temperature is about 80 to 150 ⁰ C and the pressure at about 50 to 350 bar.

The alcohol number of the obtained copolymers having hydroxyl groups depends on the number average molecular weight M _n .

C) amine synthesis

According to another suitable embodiment, the hydroformylated copolymers obtained in step viii) are subjected to further functionalization of a reaction with hydrogen and ammonia or a primary or secondary amine in the presence of an amination catalyst to give a copolymer which is at least partially functionalized with amine groups. It goes without saying that the reaction conditions are chosen so that the aromatic rings of the polymerized vinylaromatic compounds are not changed.

Suitable amination catalysts are the hydrogenation catalysts described above in step B), preferably copper, cobalt or nickel, which can be used in the form of the Raney metals or on a support. Also suitable are platinum catalysts.

In the amination with ammonia aminated copolymers are obtained with predominantly primary amino functions. Suitable for amination primary and secondary amines are compounds of the general formulas R-NH2 and RR 'NH, wherein R and R', for example, Ci-Cio-alkyl, C6-C2o-aryl, C7-C2o-arylalkyl, C7-C2o-alkylaryl or cycloalkyl. Also diamines, such as N, N-dimethylaminopropylamine and N ₁ N '- Dimethylpropylene-1-3-diamine are suitable.

The amine value of the resulting copolymers having amino functionality depends on the number average molecular weight M _n and on the number of incorporated amino groups.

ix) Co polymerization with olefinically unsaturated dicarboxylic acids

The copolymerization of the unsaturated-terminated copolymers according to the invention with unsaturated dicarboxylic acids, such as maleic acid or fumaric acid, or suitable derivatives thereof, such as maleic anhydride, maleic acid esters or fumaric acid esters, is described in EP-A-0644208, to which reference is hereby fully made. The resulting copolymers can then be further derivatized, for example by esterification or transesterification at the carboxyl groups of the dicarboxylic acid used or by their reaction with mono-, di- or polyamines to the corresponding ammonium salts or amides, and when using maleic acid or its derivatives as a comonomer also Imides, diimides or polyimides.

Preferred functionalization products are copolymers with succinic groups, in particular with succinic anhydride or with succinimide groups.

The invention will now be illustrated by the following, non-limiting examples.

Examples

General

All syntheses and reactions were carried out under argon atmosphere using the Schlenk technique. Methylene chloride was dried over calcium hydride, n-hexane was dried over sodium / benzophenone and stored over 4A molecular sieves, acetonitrile was dried over calcium hydride and stored over molecular sieves 3A.

The catalyst used was the compound of the formula 1.1

(1.1)

wherein A- is the anion of the following formula:

The catalyst was prepared analogously to the synthesis instructions of EP-A-1344785.

Polymerization reactions: copolymerization of isobutene and styrene

Pressure tubes were filled at -40 ⁰ C with 20 ml of dry dichloromethane and treated with the catalyst and a magnetic rod. Then, condensed isobutene and styrene were added (Experiment 1.1). The pressure tubes were sealed and removed from the cooling bath. The polymerization was carried out in a temperature-controlled to the desired temperature water bath. The polymerization was stopped by adding 5 ml of methanol. The reaction mixture was added with 0.2 g of 2,2'-methylene-bis (4-methyl-6-di-tert-butyl) phenol to prevent oxidation. The solvents were removed in an oil pump vacuum and the polymer obtained was dried to constant weight under high vacuum at 30 ^0C. The polymers were stored under an inert gas atmosphere.

In Experiment 1.2, styrene was first added and subjected to the polymerization reaction described above. Only then was condensed isobutene added and polymerized as described above. Experiment 1.1

Reaction conditions:

Isobutene concentration: 1.78 mol / l Styrene concentration: 0.96 mol / l Catalyst concentration: 0.5 × 10 ⁴ mol / l Solvent: dichloromethane Reaction temperature: 30 ^° C.

Polymerization time: 24 hours

Results:

Sales: 98.5%

M _n of the polymer: 1200 PDI of the polymer: 2.17

Experiment 1.2

Reaction conditions:

Isobutene concentration: 1.78 mol / l Styrene concentration: 0.96 mol / l Catalyst concentration: 0.5 × 10 ⁴ mol / l Solvent: dichloromethane Reaction temperature: 30 ^° C. Polymerization time: 24 + 6 hours

Results:

Conversion: 98.7% M _{n of} the polymer: 1700 PDI of the polymer: 2.35

Claims

claims

1. A process for the preparation of copolymers which are composed of monomers comprising isobutene and at least one vinyl aromatic compound, characterized in that isobutene or an isobutene-containing hydrocarbon mixture and at least one vinyl aromatic compound in the presence of a catalyst of the formula I.

wherein

L stands for a solvent molecule;

Z represents a singly or multiply charged ligand;

A- represents a weak or non-coordinating anion;

a is an integer greater than or equal to 1;

b is 0 or an integer greater than or equal to 1;

wherein the sum of a and b is 4 to 8; and

m is an integer from 1 to 6,

polymerized.

2. The method of claim 1, for the preparation of highly reactive copolymers which are composed of monomers comprising isobutene and at least one vinyl aromatic compound.

3. The method according to any one of claims 1 or 2, wherein the vinyl aromatic compound is styrene.

4. The method according to any one of claims 1 to 3, wherein the lanthanides are selected from cerium and samarium.

5. The method according to any one of claims 1 to 3, wherein the metals of Group 2 and 13 of the Periodic Table are selected from magnesium and aluminum.

6. The method according to any one of claims 1 to 3, wherein M is selected from V, Cr, Mo, Mn, Fe, Co, Ni, Cu and Zn.

The method of claim 6, wherein M is Mn.

8. The method according to any one of the preceding claims, wherein the Solvensmole- molecules L are the same or different and are selected from nitriles of the formula N≡CR ¹ , wherein R ^{1 is} Ci-Cβ-alkyl or aryl, and see open-chain and cyclic ethers.

9. The method of claim 8, wherein L is a nitrile of the formula N≡CR ¹ , wherein R ^{1 is} methyl, ethyl or phenyl.

10. The method according to any one of the preceding claims, wherein Z is a charged monodentate ligand selected from halides, pseudohalides, hydroxy, nitrite, alcoholates and the anions of aliphatic or aromatic monocarboxylic acids or a charged polydentate ligand selected acetylacetonate, EDTA and the anions of aliphatic or aromatic dicarboxylic acids or polycarboxylic acids.

11. A catalyst according to claim 10, wherein Z is a halide or a pseudohalogenide.

12. The method according to any one of the preceding claims, wherein A- is selected from BX ₄ -, B (Ar) ₄ -, bridged anions of the formula [(Ar) ₃ B- (μ -Y) -B (Ar) ₃ ] - , SbX ₆ -, Sb ₂ Xn ^" , AsX ₆ -, As ₂ Xn-, ReX ₆ -, Re ₂ Xn ^" , AIX ₄ -, Al ₂ X ₇ -, OTeX ₅ ^" , B (OTeXs) ₄ ^" , Nb (OTeXs) ₆ ^" , [Zn (OTeX ₅ ) ₄ ] ₂ ^" , OSeX ₅ ^" , trifluoromethanesulfonate, perchlorate, carbonates and carbon cluster anions, where

Y stands for a bridging group; and X is fluorine or chlorine.

13. The method of claim 12, wherein Y is selected from cyclic bridging groups.

14. The method according to any one of claims 12 or 13, wherein X is fluorine.

15. The method according to any one of claims 12 to 14, wherein A- is B (Ar) ₄ ^" or [(Ar) ₃ B- (M-Y) -B (Ar) ₃ ] -.

16. The method according to any one of the preceding claims, wherein a is an integer from 4 to 6.

17. The method according to any one of the preceding claims, wherein b is 0 or 1.

18. The method according to any one of the preceding claims, wherein m stands for an integer from 1 to 3.

19. The method according to any one of the preceding claims, wherein polymerizing at a temperature of at least 0 ⁰ C.

20. Highly reactive copolymer composed of monomers comprising isobutene and at least one vinylaromatic compound obtainable by a process according to one of the preceding claims.

A functionalized copolymer composed of monomers comprising isobutene and at least one vinyl aromatic compound obtainable by reacting a highly reactive copolymer according to claim 20 one of the following

Functionalization reactions are: 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, viii) hydroformylation and optionally hydrogenation or reductive Amination of the product obtained, or ix) copolymerization with an olefinically unsaturated dicarboxylic acid or a derivative thereof.