WO2010015468A1

WO2010015468A1 - Method for producing polythiophenes using hydrogen peroxide as an oxidizing agent

Info

Publication number: WO2010015468A1
Application number: PCT/EP2009/058478
Authority: WO
Inventors: Wilfried Loevenich; Hikmet Karabulut
Original assignee: H.C. Starck Clevios Gmbh
Priority date: 2008-08-06
Filing date: 2009-07-06
Publication date: 2010-02-11
Also published as: DE102008036525A1

Abstract

The invention relates to a novel method for producing optionally substituted polythiophenes, especially conductive polythiophenes, using hydrogen peroxide as an oxidizing agent in the presence of a catalyst or enzyme, preferably in the absence of inorganic salts.

Description

METHOD FOR PRODUCING POLYTHIOPHENES USING HYDROGEN PEROXIDE AS AN OXIDIZING AGENT

The invention relates to a novel process for the preparation of optionally substituted polythiophenes, in particular of optionally substituted conductive polythiophenes, with the aid of hydrogen peroxide as the oxidizing agent in the presence of a catalyst or enzyme in the absence of inorganic salts.

Conductive polymers are increasingly gaining economic importance, since polymers have advantages over metals in terms of processability, weight and the targeted adjustment of properties by chemical modification. Examples of known π-conjugated polymers are polypyrroles, polythiophenes, polyanilines, polyacetylenes, polyphenylenes and poly (p-phenylenevinylenes). Layers of viable polymers are used in a variety of industrial applications, e.g. as a polymeric counterelectrode in capacitors, as corrosion protection or for through-connection of electronic printed circuit boards. The production of conductive polymers takes place chemically or electrochemically oxidatively from precursors, such as. B. optionally substituted thiophenes, pyrroles and anilines and their respective optionally oligomeric derivatives. In particular, the chemically oxidative polymerization is widespread because it is technically easy to implement in a liquid medium or on a variety of substrates.

A particularly important and technically used polythiophene is the poly (ethylene-3,4-dioxythiophene) (PEDOT or PEDT) described, for example, in EP 339 340 A2, which is obtained by chemical polymerization of ethylene-3,4-dioxythiophene (EDOT or EDT). which has high conductivities in its oxidized form. An overview of numerous poly (alkylene

3,4-dioxythiophene) derivatives, in particular poly (ethylene-3,4-dioxythiophene) derivatives, their monomeric building blocks, syntheses and applications are L. Groenendaal, F, Jonas, D. Freitag, H. Pielartzik & JR Reynolds , Adv. Mater. 12, (2000) p. 481-494.

Dispersions of PEDOT with polystyrenesulfonic acid (PSS), as disclosed, for example, in EP 0440 957 B, have particular technical significance. From these dispersions, it is possible to produce transparent, conductive films which have found a multiplicity of applications, for example as an antistatic coating or as a hole injection layer in organic light-emitting diodes. As oxidizing agents for the polymerizate of EDT, in addition to oxygen and / or air, all oxidizing agents suitable for polypyrrole are described (J. Am.Chem.Soc., Vol. 85, pp. 454-458, 1963). In particular, ferric salts of inorganic acids, such as FeCl ₃ , and the ferric salts of organic acids and acids having organic radicals, for example, the iron-OI salts of sulfuric acid half-esters of CpCio alkanols, such as the Fe III Salt of lauryl sulfate pointed. Further, K ₂ Cr ₂ O ₇ , alkali and ammonium peroxodisulfates, such as sodium or Kaliumperoxodisυlfat, alkali metal perborates, potassium permanganate, copper salts, such as copper tetrafluoroborate or cerium (FV) salts or CeO ₂ as an oxidizing agent called. When using oxygen as the oxidizing agent is disadvantageous that the corresponding films have very high surface resistances (10 ⁷ ohm cm). The use of the other listed oxidizing agents has the disadvantage that the corresponding reaction products remain as inorganic and organic salts in the reaction mixture and thus worsen the electrical and optical properties of the film. It is described in EP 1 323 764 A1 that the corresponding salts which occur as reaction products can be removed by means of ion exchangers, which means an additional working step.

The / n-s / Yw polymerization of conductive polymers in the electrolytic capacitor has also attained particular industrial significance. EP 0340 512 B describes the preparation of a solid electrolyte from 3,4-ethylene-1,2-dioxythiophene and the use of a cationic polymer prepared by oxidative polymerization as a solid electrolyte in electrolytic capacitors. Poly (3,4-ethylenedioxythiophene) as a replacement of manganese dioxide or of charge transfer complexes in solid electrolytic capacitors reduces the equivalent series resistance of the capacitor due to the higher electrical conductivity and improves the frequency behavior. The oxidizing agents described are the same oxidizing agents which are disclosed in EP 0440 957 B. Again, the reaction products of the oxidants remain in the condenser, and must be washed out in an additional step.

Another suitable oxidizing agent for the polymerization of EDOT is hydrogen peroxide, for example, in EP 0440 957 B or EP 1 323 764 A1; However, no embodiment is described with hydrogen peroxide, the prior art discloses that hydrogen peroxide leads to an over-oxidation of PEDOT and thus to the destruction of its electrical conductivity, so that hydrogen peroxide is used for structuring PEDOT films (Adv. Mater. 2006, 18 (10), 1307-1312).

Rumbau et al. (Biomacromolecules, Vol. 8 (2), 2007, p. 315-317) state that the sole use of hydrogen peroxide as the oxidizing agent does not lead to the polymerization of EDT.

However, this polymerization succeeds when in addition the enzyme horseradish peroxidase is used in the presence of sodium polystyrenesulfonate and hydrochloric acid. In this way films with a moderate conductivity of 2 × 10 ^-3 S / cm can be produced. A disadvantage of this synthesis is that the polymerization is carried out in the presence of inorganic salts. If the reaction products of these salts are not removed, there is an impairment of the corresponding films in terms of morphology, conductivity and transparency. Upon removal of these reaction products from the dispersion, for example, by the use of an ion exchanger such as EPl 323764 Al described, an additional step is required.

In 2008, Nagarajan et al. the synthesis of a PEDT: PSS complex by the

Use of a terthiophene is started (Macromolecules, 2008, 41, 3049). The synthesis is carried out using hydrogen peroxide as the oxidizing agent and soybean peroxidase as a catalyst in the presence of Natriuropolystyroisulfonat. A disadvantage of this synthesis is that it is carried out in the presence of sodium ions and a Cϊtrat buffer, wherein the presence of these minor components leads to an impairment of the films in terms of morphology, conductivity and transparency. In addition, only moderate conductivities can be achieved with this method of synthesis. Moreover, according to this method, no pure PEDOT is produced because terthiophene is incorporated into the PEDOT polymer chain. However, PEDOT has proven to be particularly stable over other thiophenes in its oxidized form (L. Groenendaal, Adv. Mat. 2003, 15, 855).

There was therefore still a need for a simple process for the preparation of - if substituted - polythiophenes, especially on a simple process for the preparation of optionally substiuierten, conductive polythiophenes. In particular, there has been a need for a one-step synthesis of optionally substituted polythiophenes with good conductivity, with no further work-up steps to remove inorganic salts.

The object was therefore to provide such a method.

Surprisingly, it has now been found that the synthesis of optionally substituted polythiophenes, in particular of optionally substituted, conductive polythiophenes with the aid of hydrogen peroxide in the presence of catalysts or enzymes in the absence of inorganic salts can be carried out, and leads to stable dispersions from which films with good conductivity can be produced.

The invention thus provides a process for preparing an optionally substituted polythiophene with hydrogen peroxide as the oxidant in the presence of a catalyst or enzyme, characterized in that the sum of the concentrations of inorganic ions in the reaction mixture is less than 0.05 mol / L.

Optionally substituted polythiophenes optionally substituted polythiophenes containing recurring units of the general formula (I),

in which R ¹ and R ² are each independently H, an optionally substituted Cj-Cjg-alkyl radical or an optionally substituted Ci-Cjs-AIkoxyrest, or

R ¹ and R ² together represent an optionally substituted C _r C _r alkylene radical in which one or more C atom (s) may be replaced by one or more identical or different heteroatoms selected from O or S, preferably a Q-Cg - Dioxyalkylenrest, an optionally substituted Ci-Cg-Oxythiaalkylenrest or an optionally substituted Cj-Q-Dithiaalkylenrest, or an optionally substituted d-Cg-AIkylidenrest, wherein optionally at least one C-atom may be replaced by a heteroatom selected from O or S. , stand,

be used.

Here, the optionally substituted polythiophenes by oxidative polymerization of thiophenes of the general formula (II),

wherein R ¹ and R ^{2 have} the meaning given for the general formula (I) can be prepared.

In preferred embodiments, optionally substituted polythiophenes containing recurring units of the general formula (I) are those containing recurring units of the general formula (I-a) and / or the general formula (I-b)

worm

A is an optionally substituted C ₁ -C ₅ -alkylene radical _: preferably an optionally substituted C ₂ -C ₃ -alkylene radical, Y stands for O or S,

R is a linear or branched, optionally substituted Ci-Cig-alkyl radical, preferably linear or branched, optionally substituted

is an optionally substituted Cs-C ^ -Cycloalkyiresl, an optionally substituted C ₆ - C ₄ -aryl radical, an optionally substituted Cv-Cig-aralkyl radical, an optionally substituted C _r GrHydroxyalkylrest or a hydroxyl radical,

x is an integer from 0 to 8, preferably 0, 1 or 2, more preferably 0 or 1, and

in the event that several radicals R are attached to A, they may be the same or different.

These optionally substituted polythiophenes can be prepared by oxidative polymerization of thiophenes of the general formula (II-a) and / or (II-b) _s

(II-a) (II-b)

wherein A, Y, R and x are as defined for general formulas (H-a) and (II-b),

getting produced.

The general formulas (I-a) and (H-a) are to be understood such that x substituents R can be bonded to the alkyl radical A.

In further preferred embodiments, optionally substituted polythiophenes containing recurring units of the general formula (I) are those containing recurring

Units of general formula (I-aa) and / or general formula (I-ab)

wherein

R and x have the abovementioned meaning.

In still further preferred embodiments, optionally substituted polythiophenes containing recurring units of the general formula (I) are those containing polythiophenes of the general formula (I-aaa) and / or the general formula (I ~ aba)

For the purposes of the invention, the prefix poly-I means that more than one identical or different repeating unit is contained in the polythiophene. The polythiophenes contain a total of n repeating units of the general formula (I), where n can be an integer from 2 to 2000, preferably 2 to 100. The repeating units of general formula (I) may be the same or different within each polythiophene. Preference is given to polythiophenes containing in each case identical recurring units of the general formula (I).

At the end groups, the polythiophenes preferably carry H.

In particularly preferred embodiments, the polythiophene having repeating units of the general formula (I) is poly (3,4-ethylenedioxythiophene), poly (3,4-ethyleneoxythiathiophene) or poly (thieno [3,4-b] thiophene, ie a homopolythiophene repeating units of the formula (I-aaa), (I-aba) or (Ib), wherein in the formula (Ib) Y is S. In further particularly preferred embodiments, the polylhiophene having repeating units of the general formula (I) is a copolymer of recurring units of the formula (I-aaa) and (I-aba), (ϊ-aaa) and (Ib), (I-aba ) and (Ib) or (ϊ-aaa), (I-aba) and (Ib), wherein copolymers of recurring units of the formula (I-aaa) and (I-aba) and (I-aaa) and ( Ib) are preferred.

Ci-Cs-Aükylenreste A are within the scope of the invention, methylene, ethylene, n-propylene, n-butylene or n-pentylene, C _r C ₈ -AIkyIenreste additionally n ~ hexylene, n-heptylene and n-octylene. C 1 -C ₈ -alkylidene radicals in the context of the invention are Ci-Cg-alkylene radicals having at least one double bond and listed above. Cj-Cg-Dioxyalkylenreste, CRCG-Oxythiaalkyϊenreste and C _etc. - Q Dithiaalkylenreste are in the context of the invention for the Q detailed above

Cg-alkylene radicals corresponding C _r Q-DioxyaIkylenreste, Cj-Cg-Oxythiaalkylenresle and Q-Cg- Dithiaalkylenreste. Cj-Cjg-alkyl in the context of Eiiung for linear or branched C ₁ - Cis-alkyl radicals such as methyl, ethyl, n- or iso-propyl, n-, iso-, sec- or tert-Butyϊ, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylpropyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-NonyJ, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n ~ hexadecyl or n-octadecyl, ^'C ₅ -C ~ ₂ Cycloaikyl for C ₅ -C ₁₂ -cycloalkyl radicals, such as Cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl or cyclodecyl, C ₅ -C] ₄ -aryl for C ₆ -C ₄ -aryl radicals such as phenyl or naphthyl, and C ₇ -C ₈ -aralkyl for C ₇ -C ₈ -alkyl radicals such as benzyl, o-, m ~, p-tolyl, 2,3-, 2,4-, 2,5-, 2,6-, 3,4-, 3,5-xylyl or mesityl. Q-Qs-alkoxy radicals are in the context of the invention for the alkoxy radicals corresponding to the above-mentioned Q-Qg-alkyl radicals. The preceding list serves to exemplify the invention and is not to be considered as exhaustive.

As optionally further substituents of the preceding radicals are numerous organic

Groups in question, for example, alkyl, cycloalkyl, aryl, halogen, ether, thioether, disulfide, sulfoxide, sulfone, sulfonate, amino, aldehyde, keto, carboxylic acid, carboxylic acid -

Carbonate, carboxylate, cyano, alkylsilane and alkoxysilane groups and carboxylamide groups.

The polythiophenes may be neutral or cationic. In preferred embodiments they are cationic, with "cationic" referring only to the charges which are located on the polythiophene main chain Depending on the substituent on the radicals R, the polythiophenes can carry positive and negative charges in the structural unit, the positive charges on the polythiophene main chain and the negative charges are optionally present on the radicals R substituted by sulfonate or carboxylate groups, whereby the positive charges of the polythiophene main chain can be partially or completely saturated by the optionally present anionic groups on the radicals R. Overall, the polythiophenes can be cationic, neutral or even anionic in these cases

Considered all as cationic polythiophenes, since the positive charges on the poly Thiophenhauptkette are relevant. The positive charges are not shown in the formulas because their exact number and position can not be determined properly. However, the number of positive charges is at least 1 and at most n, where n is the total number of all repeating units (equal or different) within the polythiophene.

Preference is given to the process according to the invention optionally substituted, conductive

Polythiophene of the general formula (I) with a conductivity of at least 0.005 S / cm, preferably made of at least 0.05 S / cm.

To compensate for the positive charge, as far as this is not already effected by the optionally sulfonate- or carboxylate-substituted and thus negatively charged radicals R, the cationic polythiophenes require anions as counterions.

The process according to the invention is preferably carried out in the presence of at least one counterion. Suitable counterions are monomeric or polymeric anions, the latter also referred to below as polyanions.

Preferred polymeric anions are, for example, anions of polymeric carboxylic acids, such as polyacrylic acids, polymethacrylic acids or polymaleic acids, or polymeric sulfonic acids, such as polystyrenesulfonic acids and polyvinylsulfonic acids. These polycarboxylic and sulfonic acids may also be copolymers of vinyl carboxylic and vinyl sulfonic acids with other polymerizable monomers such as acrylic acid esters and styrene. These may, for example, also be partially fluorinated or perfluorinated polymers containing SO ₃ H or COOH groups.

Particularly preferred as a polymeric anion is the anion of polystyrene sulfonic acid (PSS) as a counterion.

The molecular weight of the polyanionic polyacids is preferably 1,000 to 2,000,000, more preferably 2,000 to 500,000. The polyacids or their alkali salts are commercially available, e.g. Polystyrenesulfonic acids and polyacrylic acids, or else can be prepared by known processes (see, for example, Houben Weyl, Methods of Organic Chemistry, Vol. E 20 Macromolecular Substances, Part 2, (1987), p.

Examples of monomeric anions are those of C ₁ -C 20 -alkanesulfonic acids, such as methane, etane, propane, butane or higher sulfonic acids, such as dodecanesulfonic acid, of a-aliphatic perfluorosulfonic acids, such as trifluoromethanesulfonic acid, perfluorobutanesulfonic acid or perfluorooctanesulfonic acid, aliphatic CrC ₂₀ carboxylic acids such as 2-

Ethylhexylcarboxylic acid, aliphatic perfluorocarboxylic acids, such as trifluoroacetic acid or perfluorooctanoic acid, and aromatic, optionally substituted by C _r C ₂ o-Alkylgruρpen sulfonic acids such as benzenesulfonic acid, o-toluenesulfonic acid ₅ p-ToluoIsulfonsäure, dodecylbenzenesulfonic acid, dinonylnaphthalenesulfonic acid or dinonylnaphthalenedisulfonic acid, and of cycloalkanesulfonic acids such as camphorsulfonic acid or tetrafluoroborates, hexafluorophosphates, perchlorates, hexafluoroantimonates, hexafluoroarsenates or hexachloroantimonals.

Particularly preferred are the anions of p-toluenesulfonic acid, methanesulfonic acid or camphorsulfonic acid.

Cationic polythiophenes which contain anions as counterions for charge compensation are also often referred to in the art as polythiophene / (poly) anion complexes.

Preferred thiophenes of the general formula (II-a) are those of the general formula (II-a-1) and / or (II-a-2)

Particularly preferred as thiophenes of the general formula (II-a) are those of the general

Formula (II-aa-1) and / or (II-aa-2)

used

For the purposes of the invention, derivatives of the thiophenes listed above are understood as meaning, for example, dimers or trimers of these thiophenes. There are also higher molecular weight derivatives, ie tetramers, pentamers, etc. of the monomeric precursors as derivatives possible. The derivatives can be constructed from the same or different monomer units and can be used in pure form and mixed with one another and / or with the abovementioned thiophenes. Oxidized or reduced forms of these thiophenes and thiophene derivatives are also included within the meaning of the invention by the term thiophenes and thiophene derivatives, provided that the same conductive polymers are formed during their polymerization as in the thiophenes and thiophene derivatives listed above. Processes for the preparation of the thiophenes and their derivatives are known to the person skilled in the art and are described, for example, in L. Groenendaal, F. Jonas, D. Freitag, H. Pielartzik & JR Reynolds, Adv. Mater. 12 (2000) 481-494 and references cited therein.

The thiophenes may optionally be used in the form of solutions. Suitable solvents which may be mentioned are, in particular, the following organic solvents which are inert under the reaction conditions: aliphatic alcohols, such as methanol, ethanol, isopropanol and butanol; aliphatic ketones such as acetone and methyl ethyl ketone; aliphatic carboxylic acid esters such as ethyl acetate and butyl acetate; aromatic hydrocarbons such as toluene and xyloi; aliphatic hydrocarbons such as hexane, heptane and cyclohexane; Chlorinated hydrocarbons such as dichloromethane and dichloroethane; aliphatic nitriles such as acetonitrile, aliphatic sulfoxides and

Sulfones such as dimethylsulfoxide and sulfolane; aliphatic carboxylic acid amides such as methylacetamide, dimethylacetamide and dimethylformamide; aliphatic and araliphatic ethers such as diethyl ether and anisole. Furthermore, water or a mixture of water with the aforementioned organic solvents may also be used as the solvent. Preferred solvents are alcohols and water and mixtures containing alcohols or water or mixtures of

Alcohols and water.

Thiophenes, which are liquid under the oxidation conditions, can also be polymerized in the absence of solvents.

In the context of the invention, inorganic or organic compounds which catalyze the use of hydrogen peroxide as the oxidizing agent can be used as catalyst or enzyme. Preferred compounds are peroxidases as enzymes, such as cytochrome C peroxidase, horseradish peroxidase or thyroid peroxidase. Likewise preferred are the prosthetic groups of the enzymes, for example the heme group. Also preferred are organic complexes of metal ions such as metalloporphorin complexes or metallophthalocyanine complexes (J. Mat. Chem. 2008, 18, 573-578). Particularly preferred is horseradish peroxidase and

Soybean peroxidase used.

In the context of the invention, inorganic ions are understood as meaning those ions which contain no carbon atoms. H ⁺ and OH ^" are likewise not counted among the inorganic ions in the sense of this invention, meaning that all cations of the metals such as Lf ₅ Na ⁺ , K ⁺ , Mg ²⁺ and Fe ³⁺ belong to the inorganic cations include, for example, F ^" , Cl, Br ^" , ClO ₄ ^" and SO ₄ ^2" .

Preferably, the sum of the concentrations of inorganic ions in the reaction mixture is less than 0.04 mol / L, more preferably less than 0.03 mol / L, and most preferably less than 0.02 mol / L. The fields of application of the optionally substituted polythiophenes which can be prepared by the process according to the invention are many. Thus, for example, stable dispersions or solutions comprising optionally substituted polythiophenes of the general formula (I) and a counterion or else directly conducting layers containing such polythiophenes have been prepared, in which case a large number of further compounds are used

Applications is accessible.

The above dispersions or solutions are characterized by being stable, i. these dispersions or solutions may be stored for at least 3 days, preferably for more than 30 days at room temperature, without changing the properties, such as the conductivity, of these dispersions or solutions. Thus, another object of the present invention are dispersions or solutions prepared by the inventive method.

A still further object of the present invention are conductive layers comprising dispersions or solutions prepared by the process of the present invention. Here, these conductive layers containing optionally substituted polythiophenes are polymerized, optionally substituted thiophenes or thiophene derivatives are polymerized with hydrogen as the oxidant in the presence of a catalyst or enzyme on a suitable substrate. Here, the concentration of inorganic ions in the reaction mixture is less than 0.05 mol / l.

The latter method - often referred to in the art as / o-sifw polymerization - is also used for example for the production of conductive layers, for example for the production of solid electrolytes in capacitors.

In the context of the invention, the abovementioned substrate may be, for example, glass, glass (flexible glass) or plastics to be coated in the form of shaped bodies or films and other shaped bodies to be coated, for example anodes of

Capacitors, act.

The following examples are merely illustrative of the invention and are not intended to be limiting. Examples:

Comparative Example 1: Preparation of a PBDT: PSS dispersion with the aid of hydrogen peroxide in the presence of an enzyme and inorganic salts

The comparative example was prepared according to Rumbau et al. (Biomacromolecules, Vol. 8 (2), 2007, p. 315).

317):

A solution of the sodium salt of polystyrene sulfonic acid (2.25 g, 11 mmol) in 200 g of water was mixed with ethylenedioxythiophene (EDT, Clevios M V2, HCStarck GmbH) (1.56 g, 11 mmol, 0.055 mol / L) and intensely stirred. The pH was adjusted to pH 2 with hydrochloric acid (3.0 g, 20% sol.); 60 mg of horseradish peroxidase (HRP, EC 1.11.17 type II, Aldrich) were dissolved in 20 ml of water and added. Subsequently, 1.24 g of a 30% hydrogen peroxide solution (0.11 mmol, 0.055 mol / L) was added. The mixture was stirred at 4 ° C for 16 hours (h).

The mixture thus contains concentrations of 0.05 mol / L sodium ions and 0.07 mol / L CMO ions.

After 16 hours, the content of EDT in the polymerization solution was determined by HPLC. 2.93 g / L EDT was found in the mixture, which corresponds to 42% of the starting concentration.

Determination of Surface Resistance (OFW):

Also after 16 h, a PET film was ozonized to determine the surface resistance. Subsequently, a film of the above-described mixture was prepared with a 24 μm doctor blade, and this film was dried at 130 ^° C. for 5 minutes (min.). The surface resistance was determined using a 4 point meter and was 5.5 x 10 ⁸ ohms / square.

The above mixture was allowed to stand at room temperature for 3 days; then this preparation was again doctored in the same manner as described above and the surface resistivity was again determined. The SAW was now 1 x 10 ⁹ ohms / square.

As can be seen from the OFW values, this value changes over time, ie the corresponding dispersions are not stable. Example 1 (according to the invention): Preparation of a PEDT: PSS dispersion with the aid of hydrogen peroxide in the presence of a catalyst and in the absence of salts

A solution of polystyrenesulfonic acid (2.0 g, 11 mmol) in 200 g of water was mixed with ethylenedioxythiophene (EDT, Clevios M V2, HCStarck GmbH) (0.8 g, 5.6 mmol) and stirred vigorously. 60 mg of horseradish peroxidase (HRP, EC 1.11.17 type II, Aldrich) were dissolved in 20 ml of water and added. Then, 1.2 g of a 30% hydrogen peroxide solution (10.5 mmol) was added. After 5 h, 60 mg of horseradish peroxidase (HRP, EC 1.11.17 type lϊ, Aldrich) were again dissolved in 20 ml of water and added, and 0.1 g of a 30% strength hydrogen peroxide solution (1.0 mmol) was also added. added. After a further 2 h, a solution of 20 mg horseradish peroxidase (HRP ₃ EC 1.11.17 type II, Aldrich) was redissolved in 7 ml of water and added.

After 17 h, the content of EDT in the polymerization solution was determined by HPLC. It was found 1, 5 g / L EDT in the mixture, which corresponds to 42% of the initial concentration.

After 17 h, a PET film was also ozonized to determine the SAW. Subsequently, a film of the above-described mixture was prepared with a 24 μm doctor blade and this

Film was dried at 33 ° C. for 5 minutes. The OFW was determined by means of a 4-point measuring device and was 4 x 10 ⁴ ohms / square.

The anion content of the solution was determined by ion chromatography. Cation content was determined by ICP (Inductively Coupled Plasma) atomic spray microscopy:

anion:

Sulfate 0.43 mmol / L; Chloride 0.14 mmol / L; Bromide 0.02 mmol / L

Cation content:

Al 0.01 mmol / L; Ca 0.03 mmol / L, Fe 0.01 mmol / L, Na 1.47 mmol / L

Total content: 2.11 mmol / L (= 0.00211 mol / L)

The above mixture was allowed to stand at room temperature for 3 days; then this one became

Blend again in the same manner as described above, and the SAW was again determined. The OFW was now 5.5 x 10 ⁴ ohms / square. Determination of conductivity

A cleaned glass substrate was placed on a spin coater and 10 ml of the above solution / dispersion were spread on the substrate 24 hours after preparation. Subsequently, the supernatant solution was spun off by rotation of the plate. Thereafter, the thus coated substrate was dried for 15 minutes at 200 ^° C. on a hot plate. The layer thickness was

100 nm (Tencor, Alphastep 500).

The conductivity was determined by evaporating over a shadow mask Ag electrodes 2.5 cm in length at a distance of 10 mm. The surface resistance determined with an electrometer (Keithly 614) was multiplied by the layer thickness to obtain the electrical resistivity. The resistivity of the layer was 3.7 ohm-cm.

Accordingly, the conductivity was 0.27 S / cm.

Example 2 (Invention): In-sϊtu polymerization of EDT with the aid of hydrogen peroxide in the presence of an enzyme and in the absence of salts

Ethylenedioxythiophene (1.6 g, 11.2 mmol, Cievios M V2, HCStarck GmbH) and p-toluenesulfonic acid (1.06 g, 5.6 mmol) were dissolved in a mixture of 10 g of water and 10 g of isopropanol , 120 mg of horseradish peroxidase (HRP, ECL I I .1.7 type II, Aldrich) was dissolved in 5 g of water and added. This mixture was cooled to 4 ° C. Then, 2.4 g of a 30% hydrogen peroxide solution was added, and this mixture was stirred for 5 minutes.

3 ml of sample were tumbled onto a glass substrate with a 24 μm wet-foam rack. The sample was dried for 4 h at room temperature. Subsequently, the sample was dried at 100 ^° C. for 30 minutes.

With the help of a four-point measuring device the OFW was determined: 700 kΩ / square.

Example 3 according to the invention): use of one with hydrogen peroxide in the absence of

Salts produced PEDTrPSS layer as a polymeric counter electrode in capacitors

Preparation of a tantalum anode

Capacitor anodes were made of tantalum powder (type VFI-70KD, HCStarck GmbH) and formed at 20 V and 150 mA / g in a H ₃ PO ₄ solution with the conductivity 4300 μS at 85 ⁰ C, so that on the porous sintered anode forms an electrochemically generated oxide layer.

Subsequently, these anodes were washed at 85 ⁰ C in water and then dried at 85 ⁰ C for 1 h in the oven. The anodes were coated with a Cievios polymer layer to determine the electrical values by the process described herein:

Ethylenedioxythiophene (1.6 g, 11 mmol, HC Starck GmbH, Clevios M V2) was dissolved in 10 g of water and 10 g of isopropanol. Then, p-toluenesulfonic acid (1.06 g, 6 mmol, Aidrich) was added. The mixture was cooled to 4 ° C and stirred. A solution of horseradish peroxidase (120 mg, peroxidase EORP, EC 1.11.1.7 type II, Aidrich) was dissolved in 5 g of water (5.0 g) and added followed by stirring for 0 min. Then, 2.4 g of a 30% hydrogen peroxide solution was added, and this mixture was stirred for 5 minutes. The tantalum anodes were immersed in the solution thus prepared for 60 seconds and stored at room temperature for 15 minutes. Thereafter, they were dipped in the polymerization solution again for 60 seconds and then dried at room temperature for four hours. Finally, the capacitor anodes were dried at 100 ^° C. for 30 minutes in a drying oven. To be able to electrically contact the capacitor anodes, an outer layer consisting of an ethylene dioxythiophene-based conductive polymer dispersion was applied to the anode. The external contacting was completed first with a graphite layer and then with a silver layer.

Determination of electrical properties in the capacitor

The capacitance and equivalent series resistance (ESR) of the anodes were determined by the four-point technique used in metrology using an LCR meter (Agilent 4284A), measuring capacitance at 120 Hz and ESR at 100 kHz. The median

(out of nine anodes) the capacitance was 13 μF; the median (out of nine anodes) of the ESR was measured to be 702 mθ.

Claims

claims

Process for the preparation of an optionally substituted polythiophene with hydrogen peroxide as oxidant in the presence of a catalyst or enzyme, characterized in that the sum of the concentrations of inorganic ions in the reaction mixture is less than 0.05 moi / L.

A process according to claim 1, characterized in that the optionally substituted polythiophene comprises a polythiophene containing repeating units of the general formula (I)

is, where

R ¹ and R ² are each independently H, an optionally substituted C ₁ -Cjg alkyl radical or an optionally substituted Cj-Qg alkoxy radical, or

R ¹ and R ² together represent an optionally substituted d-Cg-alkylene radical in which one or more C-atoms may be replaced by one or more identical or different heteroatoms selected from O or S, an optionally substituted C _r Cg- Oxythiaalkylenrest or an optionally substituted C _r C ₈ -DithiaalkyIrestrest, or an optionally substituted CrCg-Alkylidenrest, wherein optionally at least one C-atom may be replaced by a heteroatom selected from O or S.

3. The method according to claim 1 or 2, characterized in that the optionally substituted polythiophene containing a polythiophene containing recurring units of the general formula (I-aaa)) and / or the general formula (I-aba)

(I-aaa), (I-aba)

is.

4. The method according to at least one of claims 1 to 3, characterized in that the polymerization is carried out in the presence of at least one Polyanϊons.

5. The method according to claim 4, characterized in that the polymerization is carried out in the presence of an anion of polystyrene sulfonic acid.

6. The method according to at least one of claims 1 to 5, characterized in that are used as enzyme or catalyst peroxidases, prosthetic groups of enzymes or organic complexes of metal ions.

7. dispersion or solution prepared according to at least one of claims 1 to 6.

8. Conductive layer, characterized in that this layer comprises a dispersion or solution according to claim 7.

9. capacitor, characterized in that the capacitor as Feststoffelektoϊyt comprises a conductive layer according to claim 8.