DE19846767A1 - Partially conjugated polymer useful as an organic semiconductor or an electroluminescence material, and for display elements in television monitor and illumination technology contains fluorene building units - Google Patents

Abstract

A partially conjugated polymer including structural units containing H, optionally branched alkyl, heteroalkyl, aryl, F, Cl, CN, cycloalkyl, and individual non-adjacent alkyl CH2 groups which can be substituted by O, S, C=O, NR<5>, or aryl, heteroaryl, and structural units including Ar<1> and Ar<2>, where these are polycyclic conjugated aromatic, with one or more C atoms substituted by N, O, or S is new. The partially conjugated polymer includes structural units of formula (I): where: R<1>,R<2> = H, 1-22C optionally branched alkyl, 2-20C heteroalkyl, 5-20C aryl, f, Cl, CN, cycloalkyl, and individual alkyl non-adjacent CH2 groups, which can be substituted by O, S, C=C, COO, N-R<5>, or 2-10C aryl or heteroaryl, where aryl/heteroaryl can be substituted by one or more non-aromatic R<3> substituents, R<3> and R<4> = 1-22C alkyl, 2-20C heteroaryl, 5-20C aryl, F, Cl, SO3R<5>R<6>, where the alkyl is optionally branched or cycloalkyl, and individual non-adjacent CH2 groups in the alkyl, which can be substituted by O, S, C=O, COO, N-R<5>, or simply by aryl, and the aryl can be substituted by one or more non-aromatic R<3> substituents; R<5> and R<6> = H, 1-22C alkyl, 2-20C heteroaryl, 5-20C aryl, where the alkyl is optionally branched or is cycloalkyl; and individual non-adjacent alkyl CH2 groups, which can be substituted by O, S, C=O, COO, N-R<5>, or simply by aryl, and the aryl can be substituted by one or more non-aromatic R<3>, and m and n = 0,1,2,or 3, and structural units of formula (II), where Ar<1> and Ar<2> = a 2-40C mono- or polycyclic conjugated aromatic system, in which one or more C atoms can be substituted by N, O, or S, and one or more R<3>, and Ar<1> and Ar<2> can be bonded to a further optionally substituted C- or heteroatom so as to form a common ring, R<1> = one or several 1-22C alkyl, 2-20C heteroalkyl or 5-20C aryl. The alkyl can be optionally branched or can be cycloalkyl, and individual non-adjacent alkyl CH2 groups can be substituted by O, S, C=O, COO, N-R% or aryl, and the aryl/heteroaryl can contain one or more non-aromatic R<3> substituents. An Independent claim is included for an electroluminescence device containing the polymer.

Description

There is a high industrial need for large area solid-state light sources for a number of applications, mainly in the area of display elements, screen technology and lighting technology. Those of these light sources current requirements cannot be met by any of the existing technologies be solved completely satisfactorily.

As an alternative to conventional display and lighting elements such as Incandescent, gas discharge and non-self-illuminating Liquid crystal display elements have been around for some time Electroluminescence (EL) materials and devices, such as light emitting diodes (LED), in use.

In addition to inorganic, low-molecular organic have also been around for about 30 years Electroluminescent materials and devices are known (see e.g. US-A-3,172,862). Until recently, however, such devices were in their practical usability severely restricted.

WO 90/13148 and EP-A-0,443,861 are electroluminescent devices described a film of a conjugated polymer as a light-emitting Layer (semiconductor layer) included. Such devices offer many Advantages such as the ability to easily and large-area, flexible displays inexpensive to manufacture. In contrast to liquid crystal displays Electroluminescent displays are self-illuminating and therefore do not require any additional ones rear lighting source.

A typical device according to WO 90/13148 consists of a light-emitting device Layer in the form of a thin, dense polymer film (semiconductor layer), the contains at least one conjugated polymer. A first contact layer is in  Contact with a first surface, a second contact layer with another Surface of the semiconductor layer. The polymer film of the semiconductor layer has one sufficiently low concentration of extrinsic charge carriers, so that when Apply an electrical field between the two contact layers Charge carriers are introduced into the semiconductor layer, the one Contact layer becomes positive over the other, and the semiconductor layer Emits radiation. The polymers used in such devices are conjugated. Conjugated polymer is a polymer that contains a has delocalized electron system along the main chain. The delocalized Electron system gives the polymer semiconductor properties and gives it the Possibility of positive and / or negative charge carriers with high mobility transport.

There are already many for use in EL elements according to WO 90/13148 various polymers have been proposed. Seem particularly well suited being derivatives of poly (p-phenylene-vinyl) PPV. Such polymers are described for example in WO 98/27136. These polymers are especially for Suitable for electroluminescence in the green to red spectral range. In the blue to blue-green spectral range are mainly polymers based on the poly- p-phenylene (PPP) or polyfluorene (PF) have been proposed. Appropriate Polymers are described, for example, in EP-A-0,707,020, WO 97/05184 and WO 97/33323 described. These polymers already show good EL properties, the Development is far from complete. For example, polymers in the blue to blue-green spectral range often still problems with charge carrier injection on. Polyfluorenes specifically have the problem of low-lying HOMOs, which make hole injection difficult. This leads to the fact that in Standard EL devices necessary for efficient and long-lasting operation Balance of charge carrier injection (balance between hole and Electron injection) is difficult to achieve and thus both efficiency and also affects the life of the EL elements negatively.

The object of the present invention was therefore to provide polymers which in blue and blue-green spectral range are suitable for emission and the  at the same time improved charge carrier injection, especially hole injection Have properties.

Surprisingly, it has now been found that the installation of certain Comonomers in otherwise typical polymers, which are mainly Have fluorine building blocks that significantly improve hole injection properties without the good application properties (emission color, Loss of quantum emissions, usability in EL applications).

The polymers according to the invention contain statistically or regularly polymerized comonomer units, on the one hand, the typical properties the known polyfluorenes (emission color, processability) as far as possible preserved, on the other hand, however, the hole injection barrier clearly lower, and thus significantly improve the use in EL devices.

The invention relates to partially conjugated polymers which, in addition to structural units of the formula (I),

wherein
R ¹ , R ^{2 are} identical or different hydrogen, C ₁ -C ₂₂ alkyl, C ₂ -C ₂₀ heteroaryl, C ₅ -C ₂₀ aryl, F, Cl, CN; where the alkyl radicals mentioned above can be branched or unbranched or also represent cycloalkyls, and individual, non-adjacent CH ₂ groups of the alkyl radical by O, S, C = O, COO, NR ⁵ or also C ₂ -C ₁₀ aryls or Heteroaryls can be replaced, wherein the above-mentioned aryls / heteroaryls can be substituted with one or more non-aromatic substituents R ³ . Preferred are compounds in which R ¹ and R ^{2 are} both the same and are not hydrogen or chlorine; further preferred are compounds in which R ¹ and R ² are different from one another and also different from hydrogen;

R ³ , R ^{4 are the} same or different C ₁ -C ₂₂ alkyl, C ₂ -C ₂₀ heteroaryl, C ₅ -C ₂₀ aryl, F, Cl, CN, SO ₃ R ⁵ , NR ⁵ R ⁶ ; the alkyl radicals can be branched or unbranched or can also be cycloalkyls; and individual, non-adjacent CH ₂ groups of the alkyl radical can be replaced by O, S, C = O, COO, NR ⁵ or C ₂ -C ₁₀ aryls or heteroaryls, the above-mentioned aryls / heteroaryls having one or more non-aromatic substituents R ³ can be substituted,
R ⁵ , R ^{6 are} identical or different H, C ₁ -C ₂₂ alkyl, C ₂ -C ₂₀ heteroaryl, C ₅ -C ₂₀ aryl; the alkyl radicals can be branched or unpaved or can also be cycloalkyls; and individual, non-adjacent CH ₂ groups of the alkyl radical can be replaced by O, S, C = O, COO, NR ⁵ or also C ₂ -C ₁₀ aryls, the above-mentioned aryls being substituted by one or more nonaromatic substituents R ³ can be, and
m, n is an integer 0, 1, 2 or 3, preferably 0 or 1,
structural units of the formula (II)

wherein
Ar ¹ , Ar ^{2 are} mono- or polycyclic aromatic conjugated systems with 2 to 40 carbon atoms, in which one or more carbon atoms can be replaced by nitrogen, oxygen or sulfur, and which can be substituted by one or more substituents R ³ . It is entirely possible or in some cases even preferred that the aromatics Ar ¹ and Ar ² are linked to one another by a bond or a further substituted or unsubstituted carbon atom or hetero atom and thus form a common ring,
R ^{7 are the} same or different C ₁ -C ₂₂ alkyl, C ₂ -C ₂₀ heteroaryls or C ₅ -C ₂₀ aryl; the alkyl radicals can be branched or unbranched or can also be cycloalkyls; and individual, non-adjacent CH ₂ groups of the alkyl radical can be replaced by O, S, C = O, COO, NR ⁵ or also simple aryls, it being possible for the abovementioned aryls / heteroaryls to be substituted with one or more nonaromatic substituents R ³ , contain.

The polymer according to the invention contains at least 1 mol%, preferably 2 mol% up to 50 mol%, of structural units of the formula (II) random, alternating, periodically, or installed in blocks.

The structural units of the formula (II) are preferably derived from the following main bodies:

• - Diphenylamine derivatives, which are built into the polymer in the 4,4'-position;
• - Phenothiazine or phenoxazine derivatives, which are in the 3,7 position in the polymer are built in;
• - carbazole derivatives which are incorporated in the polymer in the 3,6-position;
• - Dihydrophenazine derivatives, which are incorporated into the polymer in the 2,6- or 2,7-position are;
• - Dihydroaciridine derivatives which are incorporated in the polymer in the 3,7 position.

The polymers according to the invention are preferably copolymers consisting of the structural units of the formulas (I) and (II). In a further embodiment of the present invention, the polymer according to the invention can also contain various structural units of the formula (I) and / or (II). Polymers which also contain other structures which do not fall under structural units (I) or (II) are also preferred. Examples of such further monomers are 1,4-phenylenes and 4,4'-biphenyls, which can optionally also carry substituents, preferably branched or unbranched C ₁ -C ₂₂ alkyl or alkoxy groups.

The polymers according to the invention generally have 10 to 10,000, preferably 10 to 5000, particularly preferably 50 to 5000, very particularly preferably 50 to 1000 repetition units.

Polymers in which m, n are equal to zero are particularly preferred, and furthermore R ¹ , R ^{2 are} both the same as the alkyl substituents defined above or are both the same as the aryl substituents defined above (which may, however, be different from one another) or R ¹ corresponds an alkyl and R ² corresponds to an aryl substituent.

The polymers according to the invention can be varied Build reactions. However, uniform C-C coupling reactions, e.g. B. Suzuki condensation and still condensation. Uniform C-C Coupling reaction in this context should mean that from the position of the reactive groups in the corresponding monomers Polymers is set. This is particularly good due to the above. Reactions that are very well suited because of the clean process. The is still suitable Nickel-catalyzed coupling of halogen aromatics (Yamamoto coupling). Fewer however, oxidative processes are good (e.g. oxidative coupling with Fe (III) salts) suitable as these lead to undefined links. From the above also results the preferred choice of the monomers: these represent the corresponding bishalogen, bispseudohalogen (i.e. in the sense of this Invention z. B. bis-triflate, bis-nonaflate, bis-tosylate), bisboronic acid, bisstannate, Monohalogen monoboronic acid, monohalogen monostannate derivatives of Compounds according to formula (I) and formula (II).

The synthesis of the polymers according to the invention is exemplified by the following scheme 1:

The radical R in the above scheme means hydrogen or any one organic radical, preferably a radical having 1 to 40 carbon atoms. Examples of this are corresponding alkyl radicals, for. B. methyl or butyl, if necessary, both residues can be bridged. Furthermore, R for one aromatic radical having 5 to 30 carbon atoms, the optionally can be substituted. The rest Hal represents a halogen atom, for example chlorine, Bromine, iodine.

Scheme 1 shows the polymerization via Suzuki coupling. It is expressly pointed out that this is only a possible one Embodiment is concerned. There are of course other combinations of Boronic acids and halogens / pseudohalogens are feasible. Analog is with corresponding tin compounds also the Stille polymerization perform.

Suzuki polymerization is carried out as follows:
The monomers on which the structural units of the formulas (I) and (II) are based (and optionally other monomers with corresponding active leaving groups) are reacted in an inert solvent at a temperature in the range from 0 ° C. to 200 ° C. in the presence of a palladium catalyst brought.

It is important to ensure that the totality of all monomers used as balanced as possible ratio of boronic acid functions to halogen or Has pseudo-halogen functions. It can also prove to be advantageous on Eventually end of reaction by endcapping with monofunctional reagents remove excess reactive groups.

To carry out the specified reaction with boronic acid (esters), the aromatic boron compounds, the aromatic halogen compounds, a base and catalytic amounts of the palladium catalyst in water or in or several inert organic solvents or preferably in a mixture of Given water and one or more inert organic solvents and at a temperature of 0 to 200 ° C, preferably at 30 to 170 ° C, particularly preferably at 50 to 150 ° C, particularly preferably at 60 to 120 ° C for one Period from 1 h to 200 h, preferably 5 h to 150 h, particularly preferably 24 h to 120 h, stirred. It can also prove to be advantageous to have a type of Monomer (e.g. bisboronic acid derivatives) continuously or discontinuously meter in slowly over a longer period of time in order to increase the molecular weight regulate. The crude product can according to the person skilled in the art and the particular Polymer appropriate methods, e.g. B. multiple falls or by Dialysis can be cleaned.

Organic solvents suitable for the process described are for example ethers, e.g. B. diethyl ether, dimethoxyethane, Diethylene glycol dimethyl ether, tetrahydrofuran, dioxane, dioxolane, diisopropyl ether, tert-butyl methyl ether, hydrocarbons, e.g. B. hexane, iso-hexane, heptane, Cyclohexane, toluene, xylene, alcohols, e.g. B. methanol, ethanol, 1-propanol, 2- Propanol, ethylene glycol, 1-butanol, 2-butanol, tert-butanol, ketones, e.g. B. acetone, Ethyl methyl ketone, iso-butyl methyl ketone, amides, e.g. B. dimethylformamide, Dimethylacetamide, N-methylpyrrolidone, nitriles, e.g. B. acetonitrile, propionitrile, Butyronitrile, and mixtures thereof.  

Preferred organic solvents are ethers, such as dimethoxyethane, Diethylene glycol dimethyl ether, tetrahydrofuran, dioxane, diisopropyl ether, t- Butyl methyl ether, hydrocarbons, such as hexane, heptane, cyclohexane, toluene, Xylene, alcohols, such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2- Butanol, tert-butanol, ethylene glycol, ketones, such as ethyl methyl ketone, iso- Butyl methyl ketone, amides, such as dimethylformamide, dimethylacetamide, N- Methyl pyrrolidone and mixtures thereof.

Particularly preferred solvents are ethers, e.g. B. dimethoxyethane, Tetrahydrofuran, hydrocarbons, e.g. B. cyclohexane, toluene, xylene, alcohols, e.g. B. Ethanol, 1-propanol, 2-propanol, 1-butanol, tert-butanol and mixtures the same.

In a particularly preferred variant in the described method Water and one or more solvents are used.

Examples are mixtures of water and toluene, water, toluene and Tetrahydrofuran as well as water, toluene and ethanol.

Bases which are preferably used in the process described Alkali and alkaline earth metal hydroxides, alkali and alkaline earth metal carbonates, Alkali metal bicarbonates, alkali and alkaline earth metal acetates, alkali and Alkaline earth metal alcoholates, as well as primary, secondary and tertiary amines.

Alkali and alkaline earth metal hydroxides, alkali and Alkaline earth metal carbonates and alkali metal bicarbonates. Alkali metal hydroxides, such as sodium hydroxide and, are particularly preferred Potassium hydroxide, and also alkali metal carbonates and alkali metal hydrogen carbonates, such as lithium carbonate, sodium carbonate and potassium carbonate.

The base is preferred in the stated process in a proportion of 100 up to 1000 mol%, particularly preferably 100 to 500 mol%, very particularly preferably 150 to 400 mol%, in particular 180 to 250 mol%, based on Boron groups used.  

The palladium catalyst contains palladium metal or a palladium (0) or (II) compound and a complex ligand, preferably a phosphine ligand. The two components can form a connection, e.g. B. the particularly preferred Pd (PPh ₃ ) ₄ , or used separately.

As the palladium component are, for example palladium compounds such as palladium ketonates, palladium acetylacetonates, nitrilepalladium halides, olefinpalladium, palladium halides, Allylpalladiumhalogenide and Palladiumbiscarboxylate, preferably palladium ketonates, palladium acetylacetonates, bis-η ² -Olefinpalladiumdihalogenide, palladium (II) halides, η ³ - Allylpalladiumhalogenid dimers and palladium, very particularly preferred bis (dibenzylidene acetone) palladium (0) [Pd (dba) ₂ )], Pd (dba) ₂ CHCl ₃ , palladium bisacetylacetonate, bis (benzonitrile) palladium dichloride, PdCl ₂ , Na ₂ PdCl ₄ , dichlorobis (dimethyl sulfoxide) palladium (II) , Bis (acetonitrile) palladium dichloride, palladium-II-acetate, palladium-II-propionate, palladium-II-butanoate and (1c, 5c-cyclooctadiene) palladium dichloride.

Palladium can also serve as a catalyst in metallic form, hereinafter only called palladium, preferably palladium in colloidal or powdered form or on a support material, for. B. palladium on activated carbon, palladium on aluminum oxide, palladium on barium carbonate, palladium on barium sulfate, palladium on aluminum silicates such as montmorillonite, palladium on SiO ₂ and palladium on calcium carbonate, each with a palladium content of 0.5 to 10% by weight. Palladium in powdered form, palladium on activated carbon, palladium on barium and / or calcium carbonate and palladium on barium sulfate, each with a palladium content of 0.5 to 10% by weight, are particularly preferred, palladium on activated carbon with a palladium content of is particularly preferred 5 or 10% by weight.

The palladium catalyst is in the process according to the invention with a Proportion of 0.01 to 10 mol%, preferably 0.05 to 5 mol%, particularly preferably 0.1 up to 3 mol%, particularly preferably 0.1 to 1.5 mol%, based on the Halogen groups used.  

Ligands suitable for the process are, for example, phosphines, such as Trialkylphosphane, Tricycloalkylphosphane, Triarylphosphane, the three Substituents on the phosphorus may be the same or different, chiral or achiral and wherein one or more of the ligands are the phosphorus groups of several Can link phosphines and being part of this link also a or can be several metal atoms.

Examples of usable in the process described here Phosphanes are trimethylphosphine, tributylphosphine, tricyclohexylphosphine, Triphenylphosphine, tritolylphosphine, tris- (4-dimethylaminophenyl) phosphane, Bis (diphenylphosphano) methane, 1,2-bis (diphenylphosphano) ethane, 1,3- Bis (diphenylphosphano) propane and 1,1'-bis (diphenylphosphano) ferrocene. Other suitable ligands are, for example, diketones, e.g. B. acetylacetone and Octafluoroacetylacetone and tert. Amines, e.g. B. trimethylamine, triethylamine, tri-n- propylamine and triisopropylamine.

Preferred ligands are phosphines and diketones, particularly preferred Phosphines.

Very particularly preferred ligands are triphenylphosphine, 1,2- Bis (diphenylphosphano) ethane, 1,3-bis (diphenylphosphano) propane and 1,1'- Bis (diphenylphosphano) ferrocene, especially triphenylphosphine. Also suitable for the process are water-soluble ligands which for example sulfonic acid salt and / or sulfonic acid residues and / or Carboxylic acid salt and / or carboxylic acid residues and / or phosphonic acid salt and / or phosphonic acid residues and / or phosphonium groups and / or Peralkylammonium groups and / or hydroxy groups and / or polyether groups included with a suitable chain length.

Preferred classes of water soluble ligands are with the above groups substituted phosphanes, such as trialkylphosphines, tricycloalkylphosphines, Triarylphosphane, Dialkylarylphosphane, Alkyldiarylphosphane and Heteroarylphosphane such as tripyridylphosphine and trifurylphosphane, the three Substituents on the phosphorus may be the same or different, chiral or achiral and wherein one or more of the ligands are the phosphorus groups of several Can link phosphines and being part of this link also a  or can be several metal atoms, phosphites, phosphinous esters and Phosphonous acid esters, phospholes, dibenzophosphols and phosphorus atoms containing cyclic or oligo- and polycyclic compounds.

The ligand is preferred in the process in a proportion of 0.1 to 20 mol% 0.2 to 15 mol%, particularly preferably 0.5 to 10 mol%, particularly preferably 1 up to 6 mol%, based on the aromatic halogen groups. It can optionally also mixtures of two or more different ligands be used.

Advantageous embodiments of the described method of the Suzuki variant are for low molecular weight couplings z. B. in WO 94/101 05, EP-A-679 619, WO-A-694 530 and PCT / EP 96/03154, to which express reference is hereby made is taken. By quotation they are considered part of the description of this Registration.

The polymerization according to Stille is carried out as follows:
The monomers on which the structural units of the formula (I) and (II) are based (and optionally further additional monomers with corresponding active leaving groups) are reacted in an inert solvent at a temperature in the range from 0 ° C. to 200 ° C. in the presence of a palladium catalyst . Care must be taken to ensure that all of the monomers used have a balanced ratio of tin organyl functions to halogen or pseudohalogen functions.

An overview of this reaction can be found e.g. B. with J. K. Stille, Angew. Chemistry Int. Ed. Engl. 1986, 25, 508.

Aromatic tin compounds, aromatic halogen compounds, in one or more inert organic Given solvent and at a temperature of 0 ° C to 200 ° C, preferably at 30 ° C to 170 ° C, particularly preferably at 50 ° C to 150 ° C, particularly preferred at 60 ° C to 120 ° C for a period of 1 h to 200 h, preferably 5 h to 150 h, particularly preferably 24 h to 120 h, stirred. It can also prove advantageous  prove to be a type of monomer (e.g. a bisstannyl derivative) continuously or add slowly discontinuously over a longer period of time to Regulate molecular weight. The crude product can be known to the person skilled in the art and methods appropriate to the respective polymer, e.g. B. multiple repatriations or can also be cleaned by dialysis.

Organic solvents suitable for the process described are for example ethers, e.g. B. diethyl ether, dimethoxyethane, Diethylene glycol dimethyl ether, tetrahydrofuran, dioxane, dioxolane, diisopropyl ether, tert-butyl methyl ether, hydrocarbon, e.g. B. hexane, iso-hexane, heptane, Cyclohexane, benzene, toluene, xylene, alcohols, e.g. B. methanol, ethanol, 1-propanol, 2- Propanol, ethylene glycol, 1-butanol, 2-butanol, tert-butanol, ketones, e.g. B. acetone, Ethyl methyl ketone, iso-butyl methyl ketone, amides, e.g. B. dimethylformamide (DMF), Dimethylacetamide, N-methylpyrrolidone, nitriles, e.g. B. acetonitrile, propionitrile, butyronitrile and mixtures thereof.

Preferred organic solvents are ethers, such as dimethoxyethane, Diethylene glycol dimethyl ether, tetrahydrofuran, dioxane, diisopropyl ether, Hydrocarbons, such as hexane, heptane, cyclohexane, benzene, toluene, xylene, Alcohols, such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, tert.- Butanol, ethylene glycol, ketones such as ethyl methyl ketone, or amides such as DMF.

Particularly preferred solvents are amides, which is very particularly preferred DMF.

The palladium and phosphine components are analogous to the description for to choose the Suzuki variant.

Exemplary monomers are listed in Scheme 2 below:

The Z radicals are the same or different and stand for hydrogen, a radical with 1 up to 30 carbon atoms, for example alkyl, aryl, alkoxy, arylalkyl, alkylaryl, Arylalkoxy or alkoxyaryl.

The suitable monomers are exemplified as described in the following scheme to synthesize:

A) 9,9-dialkyl fluorene monomers

Such monomers can be synthesized, for example, according to the following scheme 3:

In the above scheme, R and Hal are as above Meanings.

As a result, simple fluoro derivatives are to be halogenated. For m, n = 0 this is the Halogenation of fluorene. 2,7-dibromofluorene is commercially available (e.g. Aldrich). Then two of the same or two different Alkyl chains at the 9-position by deprotonation and subsequent nucleophilic Substitution with suitable alkyl halides can be introduced. This can for example according to the descriptions in WO 97/05184 and WO 97/33323 happen.

The compounds thus obtained (bishalogen fluorene derivatives) are already as Monomers can be used. Through a further implementation (metallization with subsequent reaction with either boric acid ester or trialkyltin halide) there are other monomers to be obtained: fluorene bisboronic acid derivatives, Fluorene bis tannates or, if the stoichiometry is appropriate, also Monohalofluorene monoboronic acid derivatives or Monohalofluorene monostannates. These latter implementations can  be carried out according to standard procedures, such as those described in WO 98/27136 are described.

B) 9-alkyl-9-arylfluorene monomers

Such monomers can be synthesized, for example, according to Scheme 4 below:

As a result, simple fluorenone derivatives have to be halogenated. For m, n = 0 this is the halogenation of fluorenone. For example, 2,7-dibromofluorenone commercially available (e.g. Aldrich). An alkyl chain can then be via Standard Grignard reaction will be introduced. This can, for example, according to the descriptions in the Organikum (15th edition, 1977, page 623) happen. A phenol derivative can then be added under acid catalysis. This can similar to the descriptions in WO 92/07812. The thus obtained Connection can still be etherified. This can e.g. B. Williamson's The following method is used (see Organikum, 15th edition, 1977, page 253).

As with the 9,9-dialkyl fluorene monomers, a further reaction is necessary here the corresponding fluorene bisboronic acid derivatives, fluorene bis tannates or  Monohalofluorene monoboronic acid derivatives or monohalofluorene monostannates possible.

C) 9-9-Diarylfluorene monomers

Such monomers can be synthesized, for example, according to the two routes described in Scheme 5 below:

Starting from bishalogenated fluorenone derivatives (see description of scheme 4) 4,4'-Dihalogenbiphenyl-2- carboxylic acid ester derivatives by basic ring opening with subsequent Esterification can be obtained. These connections can then be implemented with Aryl-Grignard reagents and subsequent acid-catalyzed cyclization the desired fluorene monomers are implemented. Alternatively, the bishalogenated fluorene derivative can also be used Phenol derivatives according to WO 92107812 implemented and then by Etherification to desired fluorene monomers are implemented. As with the 9,9-dialkyl fluorene monomers, a further reaction is necessary here the corresponding fluorene bisboronic acid derivatives, fluorene bis tannates or  Monohalofluorene monoboronic acid derivatives or Monohalofluorene monostannates possible.

D) monomers on which the structural unit of the formula (II) is based

As described above, the structural units of the formula (II) generally fall under the Designation of the diaryl or triarylamines (or the derivatives derived therefrom Heterocycles).

The representation of these elements is therefore relatively simple:
Starting from corresponding commercially available precursors (e.g. diphenylamine, phenothiazine, carbazole), usable monomers can be prepared by simple reactions (e.g. alkylation or arylation of the NH bond) and further processing (e.g. halogenation).
As with the 9,9-dialkyl fluorene monomers, a further reaction to the corresponding diarylamine bisboronic acid derivatives, diarylamine bis-tannates or monohalodiarylamine monoboronic acid derivatives or monohalodiaryiary amine monostannates is possible here.

It is now shown that monomers, preferably those described above Polymerization methods to be implemented polymers according to the invention can be easily accessible.

The polymers obtained in this way are very particularly preferably suitable as organic Semiconductors and especially as electroluminescent materials.

For the purposes of the invention, electroluminescent materials are materials which are considered active layer can be used in an electroluminescent device. Active layer means that the layer is capable of applying an electrical Field to emit light (light emitting layer) and / or that they are injecting and / or the transport of the positive and / or negative charges is improved (Charge injection or charge transport layer).

The invention therefore also relates to the use of a Polymers according to the invention as electroluminescent material and as organic  Semiconductor.

In order to find use as electroluminescent materials, the Polymers according to the invention generally according to known, the expert common methods, such as dipping or spin coating, applied in the form of a film to a substrate.

The invention thus also relates to an electroluminescent device with one or more active layers, at least one of these active Layers contains one or more polymers according to the invention. The active layer can, for example, a light-emitting layer and / or a transport layer and / or a charge injection layer.

The general structure of such electroluminescent devices is, for example in US-A-4,539,507 and US-A-5,151,629. Containing polymers Electroluminescent devices are described, for example, in WO 90/13148 or EP-A-0,443,861 described.

They usually contain an electroluminescent layer between one Cathode and an anode, wherein at least one of the electrodes is transparent. In addition, there can be between the electroluminescent layer and the cathode one or more electron injection and / or electron transport layers be introduced and / or between the electroluminescent layer and the Anode one or more hole injection and / or hole transport layers be introduced. Metals or metallic can preferably be used as the cathode Alloys, e.g. B. Ca, Sr, Ba, Mg, Al, In, Mg / Ag serve. Metals, e.g. B. Au, or other metallically conductive substances such as oxides, for. B. ITO (Indium oxide / tin oxide) on a transparent substrate, e.g. B. made of glass or a transparent polymer.

In operation, the cathode is set to a negative potential with respect to the anode. Thereby electrons from the cathode into the electron injection layer / elec tron transport layer or injected directly into the light-emitting layer. At the same time, holes are made from the anode into the hole injection layer / hole transport layer or injected directly into the light-emitting layer.  The injected charge carriers move under the influence of the applied ones Tension towards each other through the active layers. This leads to the Interface between the charge transport layer and the light-emitting layer or within the light-emitting layer to form electron / hole pairs that are under Recombine emission of light. The color of the emitted light can be changed the materials used as the light-emitting layer can be varied.

Electroluminescent devices are used for. B. as self-luminous Display elements, such as control lamps, alphanumeric displays, monochrome or multichromic matrix displays, signs, in electro-optical memory and in optoelectronic couplers.

Various documents are cited in the present application, for example to illustrate the technical context of the invention. On all of these documents is hereby expressly referred to, they are considered part of the quote of the present application.

The invention is illustrated by the examples, without thereby want to restrict.

A) Synthesis of the monomers 1. Preparation of the monomers according to the invention Example M1 Preparation of 3,7-dibromo-10- (2-ethylhexyl) phenothiazine

20 g (100.4 mmol) of phenothiazine were dissolved in 160 ml of dry THF under protective gas, and 4.0 g (133.4 mmol) of 80% NaH were carefully added. The mixture was stirred at room temperature for 12 h. 23.8 ml of 2-ethylhexyl bromide (133 mmol) were added with stirring and the mixture was refluxed for 5 h. 20 ml of ethanol were carefully added and filtered. The solvent was removed in vacuo and the residue was purified by fractional vacuum distillation (0.12 mbar, 128 ° C). 21.6 g (69.4 mmol, 69%) of 10- (2-ethylhexyl) phenothiazine were obtained as a viscous oil.
¹ H NMR (CDCl ₃ ): [ppm] δ = 7.18 (m, 4H, H aroma); 6.89 (m, 4H, H aroma); 3.73 (d, J = 7.2 Hz, 2H, CH ₂ -N); 2.00-1.88 (m, 1H, HC (2 ')); 1.5-1.2 (m, 8H, 4x methylene-H); 0.87 (2 × t, J = 7.3 Hz, 6H, 2 × CH ₃ ).

The intermediate was further converted to 3,7-dibromo-10- (2-ethylhexyl) phenothiazine:
A solution of 15.6 g (50 mmol) of 10- (2-ethylhexyl) phenothiazine in 25 ml of chloroform was mixed with 5.4 ml (105 mmol) of bromine in 10 ml of chloroform within 10 minutes at room temperature. After the addition had ended, the solution was refluxed for a further 1 h. After cooling, the mixture was saturated twice with 20 ml each time. aqueous Na ₂ SO ₃ solution and washed once with 50 ml of water. Activated carbon was added, the mixture was boiled briefly and filtered. Then it was filtered with chloroform through a 5 cm silica gel column. After removing the solvent in vacuo, the mixture was purified by fractional distillation (0.01 mbar, 160 ° C.). 20.1 g (42.8 mmol, 86%) of 3,7-dibromo-10- (2-ethylhexyl) phenothiazine were obtained as a slightly yellow oil.
¹ H NMR (CDCl ₃ ): [ppm] δ = 7.24-7.23 (m, 4H, H-aroma); 6.71-6.69 (m, 2H, H aroma); 3.63 (d, J = 7.2 Hz, 2H, CH ₂ -N); 1.91-1.82 (m, 1H, HC (2 ')); 1.50-1.20 (m, 8H, 4x methylene-H); 0.86 (2 × t, J = 7.2 Hz, 6H, 2 × CH ₃ ).

Example M2 Preparation of 4,4'-dibromotriphenylamine

The presentation was carried out analogously to K. Haga et al. Bull. Chem. Soc. Jpn., 1986, 59,
803-7:

3.10 g (10.4 mmol) of bis (4-bromophenyl) amine (J. Berthelot et al, Can. J. Chem., 1989, 67, 2061), 1.28 g of cyclohexane-1,4-dione (11.4 mmol) and 2.17 g (11.4 mmol) of p-toluenesulfonic acid hydrate were heated in 50 ml of toluene on a water separator. After a reaction time of 12 h, the solvent was removed and purified by column chromatography (hexane / ethyl acetate 4: 1). 3.82 g (9.46 mmol, 91%) of 4,4'-dibromotriphenylamine were obtained as a viscous oil.
¹ H NMR (CDCl ₃ ): [ppm] δ = 7.01-6.95 (m, 5H), 6.88, 6.74 (AA'BB ', 4 + 4H).

2. Production of further comonomers Example CM1 Preparation of 2,7-dibromo-9,9-bis (2-ethylhexyl) fluorene

The presentation was carried out in analogy to Example 1 in WO 97/05184. The product (84% yield) could by double distillation on a short path evaporator [10 ^-3 mbar; 1. Distillation (to separate excess ethylhexyl bromide and residual DMSO) 100 ° C; 2. Distillation: 155 ° C] can be obtained as a highly viscous light yellow oil.
¹ H NMR (CDCl ₃ ): [ppm] δ = 7.54-7.43 (m, 6H, H-aryl); 1.93 (d with Fs., 4H, J = 4.0 Hz); 1.0-0.65 (m, 22H, H-alkyl); 0.58-0.45 (m, 8H, H-alkyl).

Example CM2 Preparation of 9,9-bis (2-ethylhexyl) fluorene-2,7-bisboronic acid bisglycol ester

Magnesium (6.32 g, 0.26 mol) was placed in 10 ml of THF and a little iodine was added and a few drops of 2,7-dibromo-9,9-bis (2-ethylhexyl) fluorene were added. The The start of the reaction was recognizable by strong exotherm. Subsequently the remaining amount of bisbromide (total 68.56 g, 0.125 mol) and 300 ml of THF were added dropwise. After the addition was complete, the mixture was left for approx. 5 h refluxed. Only small amounts of Mg chips could be seen. In parallel, trimethyl borate (28.6 g, 0.27 mol) in THF (200 ml) submitted and cooled to -70 ° C. At this temperature the Grignard solution slowly added dropwise. The mixture was then slowly stirred overnight Warmed to room temperature.

The reaction solution was concentrated to 300 ml of ice water and 10 ml of sulfuric acid. given and the organic phase separated. The organic phase was washed once more with water (neutral). After drying over Na ₂ SO ₄ , the mixture was evaporated. The crude product was stirred with hexane (500 ml). This gave the crude bisboronic acid (this contains variable amounts of different anhydrides). This was esterified directly by refluxing (12 h) in toluene with ethylene glycol and sulfuric acid on a water separator.
Yield over both stages: 70-85%. Purity (NMR) <98.5%
¹ H NMR (CDCl ₃ ): (NMR signals greatly broadened or doubled due to diastereomerism) δ = 7.86 (m, 2H, H-1), 7.79 (m, 2H, H-3), 7.73 (d, 2H , H-4, J = 8 Hz), 4.38 (s (br), 8H, O-CH ₂ ), 2.02 (m, 4H, C-CH ₂ -), 0.75 (m (br), 22H, H- Alkyl), 0.47 (m (br), 8H, H-alkyl).

B) Synthesis of the polymers Example P1 Copolymerization of 9,9-bis (2-ethylhexyl) fluorene-2,7-bisboronic acid bisglycol ester, 2,7-dibromo-9,9-bis (2-ethylhexyl) fluorene and 5 mol% 3,7-dibromo-10- (2- ethylhexyl) phenothiazine by Suzuki reaction (polymer P1)

9,872 g (18.00 mmol) of 2,7-dibromo-9,9-bis (2-ethylhexyl) fluorene, 10,608 g (20.00 mmol) of 9,9-bis (2-ethylhexyl) fluorene-2,7-bisboronic acid diethylene glycol ester, 938 mg (2 mmol) of 3,7-dibromo-10- (2-ethylhexyl) phenothiazine, 11.61 g (84 mmol) of K ₂ CO ₃ , 40 ml of toluene, 20 ml of water and 1 ml of ethanol were degassed for 30 min by passing through N ₂ . Then 350 mg (0.3 mmol) Pd (PPh ₃ ) ₄ was added under protective gas. The suspension was stirred vigorously under an N ₂ blanket at an internal temperature of 87 ° C. (slight reflux). After 4 days, a further 0.40 g of 9,9-bis (2-ethylhexyl) fluorene-2,7-bisboronic acid diethylene glycol ester was added. After heating for a further 6 hours, 0.5 ml of bromobenzene were added and the mixture was heated under reflux for a further 3 hours.

The reaction solution was diluted with 200 ml of toluene, the solution was stirred with 200 ml of 2% aqueous NaCN for 3 h. The mixture lightened almost completely. The organic phase was washed with H ₂ O and precipitated by adding it in 800 ml of ethanol.

The polymer was dissolved in 250 ml of THF at 40 ° C. for 1 h, precipitated with 300 ml of MeOH, washed and dried in vacuo (7.70 g). In 200 ml of THF / 250 ml of methanol was reprecipitated again, suction filtered and dried to constant mass. 4.87 g (12.7 mmol, 32%) of the polymer P1 were obtained as a slightly yellow solid.
¹ H NMR (CDCl ₃ ): [ppm] δ = 8.1-7.3 (m, 6H fluorene + 5% of 4H phenothiazine); 7.0 (m, 5% of 2H phenothiazine); 3.85 (m, 5% of 2H, N-CH ₂ phenothiazine), 2.15 (brs, 4H CH ₂ -C (9)); 1.1-0.4 (m, 30H, alkyl-H + 5% of 15H, alkyl-H-phenothiazine). By integrating and comparing the signals at 3.85 ppm and 2.15 ppm, a phenothiazine group content of 5% was determined; this corresponds to the ratio of the monomers used.
GPC: THF + 0.25% oxalic acid; Column set SDV 500, SDV 1000, SDV 10,000 (PPS), 35 ° C, UV detection 254 nm: M _w = 92,000 g / mol, M _n = 54,000 g / mol.
UV-Vis (film): λ _max = 376 nm
PL (film): λ _max = 472 nm

Example P2 Copolymerization of 9,9-bis (2-ethylhexyl) fluorene-2,7-bisboronic acid bisglycol ester, 2,7-dibromo-9,9-bis (2-ethylhexyl) fluorene and 25 mol% 3,7-dibromo-10- (2- ethylhexyl) phenothiazine by Suzuki reaction (polymer P2)

5,485 g (10.00 mmol) of 2,7-dibromo-9,9-bis (2-ethylhexyl) fluorene, 10,608 g (20.00 mmol) of 9,9-bis (2-ethylhexyl) fluorene-2,7-bisboronic acid diethylene glycol ester, 4,693 g (10 mmol) 3,7-dibromo-10- (2-ethylhexyl) phenothiazine, 11.61 g (84 mmol) K ₂ CO ₃ and 350 mg (0.3 mmol) Pd (PPh ₃ ) ₄ were in 40 ml toluene, 20 ml Water and 1 ml of ethanol reacted as described in Example P1. After working up analogously and reprecipitated three times from THF / methanol, 4.76 g (12.9 mmol, 32%) of the polymer P2 were obtained as a yellow solid.
¹ H NMR (CDCl ₃ ): [ppm] δ = 7.9-7.3 (m, 6H fluorene + 25% of 4H phenothiazine); 7.0 (br. M, 25% of 2H phenothiazine); 3.84 (m, 25% of 2H, N-CH ₂ phenothiazine); 2.07 (br. S, 4H CH ₂ -C (9) fluorene), 1.7-0.4 (m, 30H, alkyl-H + 25% of 15H, alkyl-H-phenothiazine). By integrating and comparing the signals at 3.84 ppm and 2.07 ppm, a phenothiazine group content of 25% was determined; this corresponds to the ratio of the monomers used.
GPC: THF + 0.25% oxalic acid; Column set SDV 500, SDV 1000, SDV 10,000 (PPS), 35 ° C, UV detection 254 nm: M _w = 72,000 g / mol, M _n = 43,000 g / mol.
UV-Vis (film): λ _max = 373 nm
PL (film): λ _max = 480 nm

Example P3 Copolymerization of 9,9-bis (2-ethylhexyl) fluorene-2,7-bisboronic acid bisglycol ester, 2,7-dibromo-9- (2,5-dimethylphenyl) -9- (4- (3,7-dimethyloctyloxy) phenyl) fluorene and 10 mol% 4,4'-dibromotriphenylamine by Suzuki reaction (polymer P3)

8,775 g (16.00 mmol) of 2,7-dibromo-9,9-bis (2-ethylhexyl) fluorene, 10,608 g (20.00 mmol) of 9,9-bis (2-ethylhexyl) fluorene-2,7-bisboronic acid diethylene glycol ester, 1,612 g (4 mmol) 4,4'-dibromotriphenylamine, 11.61 g (84 mmol) K ₂ CO ₃ and 350 mg (0.3 mmol) Pd (PPh ₃ ) ₄ were reacted in 40 ml toluene, 20 ml water and 1 ml ethanol as in Example P1 described. After working up analogously and reprecipitation three times from THF / methanol, 5.89 g (15.7 mmol, 39%) of the polymer P3 was obtained as a slightly beige solid.
¹ H NMR (CDCl ₃ ): [ppm] δ = 7.9-7.0 (m, 6H fluorene + 10% of 11H triphenylamine), 6.85 (br. M, 10% of 2H triphenylamine), 2.12 (br. S, 4H CH ₂ -C (9) fluorene), 1.2-0.4 (m, 30H, alkyl-H).
GPC: THF + 0.25% oxalic acid; Column set SDV 500, SDV 1000, SDV 10,000 (PPS), 35 ° C, UV detection 254 nm: M _w = 110,000 g / mol, M _n = 67000 g / mol.
UV-Vis (film): λ _max = 375 nm
PL (film): λ _max = 419 nm, 447 nm

Comparative examples Example V1 Suzuki polymerization of 2,7-dibromo-9,9-bis (2-ethylhexyl) fluorene and 9,9-bis (2- ethylhexyl) fluoren-2,7-bisboronic acid bisglycolester (polymer V1), production of Poly-2,7- [9,9-bis (2-ethylhexyl) fluorene]

8,227 g (15.00 mmol) 2,7-dibromo-9,9-bis (2-ethylhexyl) fluorene, 7,956 g (15.00 mmol) 9,9-bis (2-ethylhexyl) fluorene-2,7-bisboronic acid diethylene glycol ester, 8.71 g (63 mmol) K ₂ CO ₃ , 25 ml toluene and 15 ml water were degassed for 30 min by passing N ₂ through. Then 230 mg (0.2 mmol) of Pd (PPh ₃ ) ₄ was added under protective gas. The suspension is stirred vigorously under an N ₂ blanket at an internal temperature of 87 ° C. (slight reflux). After 2 days a further 20 ml of toluene were added, after a further 2 days a further 0.20 g of 9,9-bis (2-ethylhexyl) fluorene-2,7-bisboronic acid diethylene glycol ester were added. After a further 6 hours, 0.5 ml of 4-bromofluorobenzene was added and the mixture was heated under reflux for a further 3 hours.

The work-up was carried out as indicated in Example P1. 3.85 g (9.9 mmol, 33%) of polymer V1 were obtained as a slightly beige solid.
¹ H NMR (CDCl ₃ ): [ppm] δ = 7.9-7.3 (m, 6H, H-aroma); 2.15 (br. S, 4H, C (9) -CH ₂ ); 1.1-0.4 (m, 30H, H-alkyl).
GPC: THF + 0.25% oxalic acid; Column set SDV 500, SDV 1000, SDV 10,000 (PPS), 35 ° C, UV detection 254 nm: M _w = 70,000 g / mol, M _n = 34,000 g / mol.
UV-Vis (film): λ _max = 376 nm
PL (film): λ _max = 420 nm, 444 nm

C) Use of the polymer P1 to P3 or V1 and V2 as EL materials

All 5 mentioned polymers are capable of electroluminescence in the arrangement ITO // PEDOT (100 nm) // polymer (80 nm) // Ca (5 nm) - Ag (100 nm) when an external field is applied. It turns out, however, that in particular polymers P1 and P3 (which have a PL efficiency similar to V1 and V2), even at significantly lower voltages (in the chosen laboratory test setup - not optimized with regard to the design and manufacture): at 5.5 or 4.8 V (see 8 or 7.7 V) provide the current density sufficient for the emission of light with a brightness of 200 Cd / m ² . In this context, it should be explicitly pointed out that these are still results that were achieved with laboratory test arrangements. These can usually be significantly improved under optimal conditions. The voltages previously required should be significantly reduced in the course of device optimization. However, the polymers P1 and P3 have the desired effect that lower voltage is required for the same brightness.

Polymer P2 is a special case: the LEDs show high current flows relatively low voltages, but the brightnesses are low. This is due to the significantly lower PL efficiency of this polymer.

Claims (8)

1. Partially conjugated polymers which, in addition to structural units of the formula (I),
wherein
R ¹ , R ^{2 are} identical or different hydrogen, C ₁ -C ₂₂ alkyl, C ₂ -C ₂₀ heteroaryl, C ₅ -C ₂₀ aryl, F, Cl, CN; where the alkyl radicals mentioned above can be branched or unbranched or can also be cycloalkyls, and individual, non-adjacent CH ₂ groups of the alkyl radical by O, S, C = O, COO, NR ⁵ or else C ₂ -C ₁₀ aryls or Heteroaryls can be replaced, where the abovementioned aryls / heteroaryls can be substituted with one or more non-aromatic substituents R ³ ,
R ³ , R ^{4 are the} same or different C ₁ -C ₂₂ alkyl, C ₂ -C ₂₀ heteroaryl, C ₅ -C ₂₀ aryl, F, Cl, CN, SO ₃ R ⁵ , NR ⁵ R ⁶ ; the alkyl radicals can be branched or unbranched or can also be cycloalkyls; and individual, non-adjacent CH ₂ groups of the alkyl radical can be replaced by O, S, C = O, COO, NR ⁵ or C ₂ -C ₁₀ aryls or heteroaryls, the above-mentioned aryls / heteroaryls having one or more non-aromatic substituents R ³ can be substituted,
R ⁵ , R ^{6 are} identical or different H, C ₁ -C ₂₂ alkyl, C ₂ -C ₂₀ heteroaryl, C ₅ -C ₂₀ aryl; the alkyl radicals can be branched or unbranched or can also be cycloalkyls; and individual, non-adjacent CH ₂ groups of the alkyl radical can be replaced by O, S, C = O, COO, NR ⁵ or also simple C ₂ -C ₁₀ aryls, the above-mentioned aryls having one or more nonaromatic substituents R ³ can be substituted, and
m, n is an integer 0, 1, 2 or 3, preferably 0 or 1,
also structural units of the formula (II)
wherein
Ar ¹ , Ar ^{2 are} mono- or polycyclic aromatic conjugated systems with 2 to 40 carbon atoms, in which one or more carbon atoms can be replaced by nitrogen, oxygen or sulfur, and which can be substituted by one or more substituents R ³ , and the Ar ¹ and Ar ² are linked together by a bond or a further substituted or unsubstituted C atom or hetero atom and can thus form a common ring,
R ^{1, the} same or different, is C ₁ -C ₂₂ alkyl, C ₂ -C ₂₀ heteroaryl or C ₅ -C ₂₀ aryl; the alkyl radicals can be branched or unbranched or can also be cycloalkyls; and individual, non-adjacent CH ₂ groups of the alkyl radical can be replaced by O, S, C = O, COO, NR ⁵ or also simple aryls, it being possible for the abovementioned aryls / heteroaryls to be substituted with one or more nonaromatic substituents R ³ ,
contain. 2. Polymers according to claim 1, characterized in that R ¹ and R ^{2 are} both the same and are not hydrogen or chlorine. 3. Polymers according to claim 1, characterized in that R ¹ and R ² are different from one another and also different from hydrogen. 4. Polymers according to one of claims 1 to 3, characterized in that there is at least 1 mol% of structural units of the formula (II) random, alternating, periodically, or built into blocks.   5. Polymers according to claim 3, characterized in that it is 2 to 50 mol% contains structural units of the formula (II) incorporated. 6. Polymers according to one of claims 1 to 5, characterized in that the polymer contains 10 to 10,000 repeat units of the formulas (I) and (II). 7. Use of the polymer according to one of claims 1 to 6 as organic semiconductor and / or as electroluminescent material. 8. Electroluminescent device containing a polymer according to one of the Claims 1 to 6.