Process for producing functionalized polythiophenes

Abstract

A process for producing a liquid composition comprising a functionalized π-conjugated polythiophene, and the liquid composition, are provided. i) a) a thiophene monomer of general formula (I) (wherein X and Y are the same or different and are O, S, or NR 1 and R 1 is hydrogen or an aliphatic or aromatic residue having 1 to 18 carbon atoms, and A is an organic residue bearing an anionic functional group; b) an oxidizing agent; and c) a solvent; and ii) oxidatively polymerizing a thiophene monomer of general formula (I), wherein the pH of the liquid phase in i) is adjusted to a value of less than 7.0 at 20°C, and the chloride content of the liquid phase in i) is less than 10,000 ppm, based on the total weight of the liquid phase. TIFF2023071860000029.tif39170

Description

[Technical Field]

[0001] The present invention relates to a process for producing a liquid composition comprising a functionalized π-conjugated polythiophene, a liquid composition obtained by the process, and a method for producing a liquid composition comprising a functionalized π-conjugated polythiophene having a specific ratio of weight average molecular weight M w and the molar average molecular weight M n the functionalized π-conjugated polythiophene comprises different repeat units in defined amounts; a process for preparing such a liquid composition; a process for making a capacitor in which these liquid compositions are used to form a solid electrolyte; a capacitor obtained by this process; and the use of the liquid composition to make a conductive layer. [Background technology]

[0002] Generally, commercially available electrolytic capacitors are made from a porous metal electrode, an oxide layer on the metal surface that functions as a dielectric, a dielectric material, usually a solid material incorporated into the porous structure, an outer electrode (contact) such as a silver layer, and further electrical contacts and encapsulants. A frequently used electrolytic capacitor is the tantalum electrolytic capacitor, whose anode electrode is made from the valve metal tantalum, on which a homogeneous dielectric layer of tantalum pentoxide is anodized (also called "formed"). A liquid or solid electrolyte forms the cathode of the capacitor. Aluminum capacitors more frequently use the anode electrode made from the valve metal aluminum, on which a homogeneous, electrically insulating aluminum oxide layer is anodized as a dielectric. Again, a liquid or solid electrolyte forms the cathode of the capacitor. Aluminum capacitors are typically constructed as wound or stacked capacitors.

[0003] π-conjugated polymers are particularly suitable as solid electrolytes in these capacitors due to their high electrical conductivity. π-conjugated polymers are also called conductive polymers or synthetic metals. They are becoming increasingly important economically because they offer advantages over metals in terms of processability, weight, and the ability to tailor their properties through chemical modification. Examples of well-known π-conjugated polymers are polypyrrole, polythiophene, polyaniline, polyacetylene, polyphenylene, and poly(p-phenylene-vinylene). A particularly important polythiophene used industrially is poly(3,4-ethylenedioxythiophene) (PEDOT), due to its extremely high electrical conductivity in its oxidized form.

[0004] Solid electrolytes based on conductive polymers can be applied to oxide layers in various ways. Patent document 1, for example, describes the preparation of a solid electrolyte from 3,4-ethylenedioxythiophene and its use in electrolytic capacitors. According to the teachings of Patent document 1, 3,4-ethylenedioxythiophene is polymerized in situ on the oxide layer. In addition to in situ polymerization, a process for preparing a solid electrolyte in a capacitor is also known in the prior art, in which a dispersion containing already polymerized thiophene and a polyanion as counterion, such as the PEDOT / PSS dispersion (PEDOT = poly(3,4-ethylenedioxythiophene); PSS = polystyrene sulfonic acid) known from the prior art, is applied to the oxide layer, and the dispersion is then removed by evaporation. A process for preparing such a solid electrolytic capacitor is disclosed, for example, in Patent document 2.

[0005] However, PEDOT / PSS dispersions suffer from the disadvantage that they contain a significant amount of PSS as a non-conductive inactive material. Furthermore, due to the presence of PSS, the size of the PEDOT / PSS particles in the dispersions is sometimes too large to ensure that the particles penetrate into the smaller pores of the porous metal electrode. Finally, the maximum solid content of PEDOT / PSS dispersions is often limited to a value of approximately 3 wt%. To overcome these disadvantages, liquid compositions containing PEDOT derivatives that are not characterized by the disadvantages of known PEDOT / PSS dispersions have been prepared. Polythiophenes functionalized with sulfonic acid groups were first developed. Due to the sulfonic acid groups, these polythiophenes are self-doping and do not require counterions such as PSS. Patent Document 3 discloses the preparation of functionalized π-conjugated polymers such as poly(4-(2,3-dihydrothieno[3,4-b][1,4]dioxin-2-ylmethoxy)-1-butanesulfonic acid) (PEDOT-S) by oxidative polymerization of the corresponding monomer 4-(2,3-dihydrothieno[3,4-b][1,4]dioxin-2-ylmethoxy)-1-butanesulfonic acid (EDOT-S). However, the conductivity of the conductive layers prepared by the polymer solutions obtained in Patent Document 3 is usually too low to use these polymer solutions to prepare solid electrolyte layers in solid electrolytic capacitors, for example. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] European Patent No. 0340512 [Patent Document 2] German Patent Application No. 10 2005 043 828 [Patent Document 3] European Patent No. 1122274A1 Summary of the Invention [Problem to be solved by the invention]

[0007] It was therefore an object of the present invention to overcome the disadvantages of the prior art in the field of water-soluble π-conjugated polymers.

[0008] In particular, it was an object of the present invention to provide a composition comprising a water-soluble or water-dispersible π-conjugated polymer, which is characterized by an increased conductivity of the conductive layer prepared from the composition of the present invention compared to the corresponding compositions known from the prior art.

[0009] It was also an object of the present invention to provide a composition comprising a water-soluble or water-dispersible π-conjugated polymer which, when used for the formation of a solid electrolyte layer in a capacitor, leads to beneficial properties of the capacitor, in particular a beneficial capacitance and / or a beneficial ESR (equivalent series resistance), compared to capacitors with a solid electrolyte layer prepared using corresponding compositions known from the prior art.

[0010] It was also an object of the present invention to provide a composition comprising a water-soluble or water-dispersible π-conjugated polymer that, when used to form a solid electrolyte layer in a capacitor, helps improve the stability of the capacitor when stored at high temperatures and high relative humidity. The stability of a capacitor under such storage conditions is defined in terms of the degree to which the electrical properties of the capacitor, particularly the capacitance and ESR, deteriorate during storage. [Means for solving the problem]

[0011] A contribution to the solution of at least one of the above objects is provided by the subject matter of the independent claims which form a category, as well as by the dependent claims which present preferred embodiments of the invention whose subject matter contributes to solving at least one object.

[0012] Embodiment I. 1. A process for producing a liquid composition comprising a functionalized π-conjugated polythiophene, comprising: i) a) Thiophene monomers of general formula (I) [ka] (In the formula, X and Y are the same or different and are O, S, or NR 1 where R 1 is hydrogen or an aliphatic or aromatic residue having 1 to 18 carbon atoms, A is an organic residue bearing an anionic functional group; b) an oxidizing agent, and c) Solvent providing a liquid phase comprising: ii) oxidatively polymerizing the thiophene monomer of general formula (I) to obtain a liquid composition comprising a functionalized π-conjugated polythiophene; where: (α1) the pH of the liquid phase provided in process step i) is adjusted to a value less than 7.0, said pH being determined at a temperature of 20°C; (α2) the chloride content of the liquid phase provided in process step i) is less than 10,000 ppm, based on the total weight of the liquid phase; process.

[0013] II. (α3) The process of embodiment I, wherein the oxygen content of the liquid phase provided in process step i) is less than 1000 ppm, based on the total weight of the liquid phase.

[0014] III. X and Y are O, A is -(CH2) m -CR 2 R 3 -(CH2) n -where: R 2 is hydrogen or -(CH2) s -Z-(CH2) p -SO3 - M + and R 3 is -(CH2) s -Z-(CH2) p -SO3- M + and Z is O, S or -CH2-; M + is a cation, m and n are the same or different and are integers from 0 to 3; s is an integer from 0 to 10, p is an integer from 1 to 18; The process of embodiment I or II.

[0015] IV. In the general formula (I), X and Y are O, A is -(CH2)-CR 2 R 3 -(CH2) n -where: R 2 is hydrogen, R 3 is -(CH2) s -O-(CH2) p -SO3 - M + and M + Na + or K + and n is 0 or 1, s is 0 or 1, p is 4 or 5; The process of any one of embodiments I-III.

[0016] V. X and Y are O, A is —(CH—CHR)—, where R is -(CH2) t -O-Ar-[(W) u -SO3 - M + ] v where: Ar is an optionally substituted C6-C 20 represents an arylene group, W represents an optionally substituted C1-C6 alkylene group; M + is H + , Li + , Na + , and K. + an alkali cation selected from the group consisting of NH(R 1 )3 or HNC5H5, where each R 1 groups independently represent a hydrogen atom or an optionally substituted C1-C6 alkyl group; t represents an integer of 0 to 6, u represents an integer of 0 or 1; v represents an integer of 1 to 4; The process of embodiment IV.

[0017] VI. The process of any one of embodiments I-V, wherein the oxidizing agent b) is a salt of a heavy metal, a salt of peroxodisulfuric acid, or a mixture thereof.

[0018] VII. The process of any one of embodiments I-V, wherein the thiophene monomers are polymerized by electrochemical polymerization and the oxidizing agent b) is an electrode.

[0019] VIII. The process of any one of embodiments I-VII, wherein the solvent c) is water.

[0020] IX. The process of any one of embodiments I to VIII, wherein the pH of the liquid phase provided in process step i) is adjusted to a value below 7.0 using an organic or inorganic acid.

[0021] X. The process of any one of embodiments I-IX, wherein the oxidative polymerization in process step ii) is carried out under an inert gas atmosphere of nitrogen, argon, carbon dioxide, or a mixture thereof.

[0022] XI. The process of embodiment X, wherein the oxidative polymerization in process step ii) is carried out under a pressure that is equal to or greater than the vapor pressure of the liquid phase during the polymerization reaction in process step ii).

[0023] XII. The process of any one of embodiments I to XI, wherein the oxidative polymerization in process step ii) is carried out under reduced pressure of 0.8 bar or less.

[0024] XIII. The process according to any one of embodiments I to XII, wherein in a further process step iii) the liquid composition obtained in process step ii) is purified.

[0025] XIV. The process of embodiment XIII, wherein the purification is by filtration and / or by treatment with an ion exchanger.

[0026] XV. The process of any one of embodiments I to XIV, wherein the particle size distribution of the functionalized π-conjugated polythiophene in the liquid composition obtained in process step ii) or process step iii) is adjusted by treating the liquid composition with ultrasound, by treating the liquid composition with high-pressure homogenization, or by treating the liquid composition with heat.

[0027] XVI. A liquid composition obtainable by the process of any one of embodiments I to XV.

[0028] XVII. A liquid composition comprising a functionalized π-conjugated polythiophene, said polythiophene having repeating units of general formula (I): [ka] wherein X, Y, and A are as defined in embodiments I, III, IV, and V. wherein the functionalized π-conjugated polythiophene has a weight average molecular weight M w relative to the molar average molecular weight M n The ratio (M w / M n ) is at least 6, preferably at least 8, more preferably at least 10, more preferably at least 12, more preferably at least 14, more preferably at least 16, more preferably at least 18, more preferably at least 20.

[0029] XVIII. M w / M n is at most 100, preferably at most 75, more preferably at most 50.

[0030] XIX. The functionalized π-conjugated polythiophene has a weight average molecular weight M w is at least 50000 g / mol, preferably at least 75000 g / mol, more preferably at least 100000 g / mol, and most preferably at least 125000 g / mol.

[0031] XX. The functionalized π-conjugated polythiophene has a weight average molecular weight M w is in the range of 125000 g / mol to 240000 g / mol, preferably in the range of 125000 g / mol to 210000 g / mol.

[0032] XXI. The molar average molecular weight M of the functionalized π-conjugated polythiophene w The liquid composition according to any one of embodiments XVII to XX, wherein the δ is less than 25000 g / mol, preferably less than 20000 g / mol, more preferably less than 15000 g / mol.

[0033] XXII. The functionalized π-conjugated polythiophene is present in the liquid composition in the form of particles, the particle size distribution being: i) d in the range of 1 to 100 nm, preferably in the range of 1 to 80 nm, more preferably in the range of 1 to 60 nm, and most preferably in the range of 5 to 40 nm 50 value (weight average particle size), and ii) 3.5 × d 50 Less than 3 × d 50 less than 2 × d 50 Less than d 90 value The liquid composition according to any one of embodiments XVII to XXI, characterized by:

[0034] XXIII. the functionalized π-conjugated polythiophene comprises a repeat unit of general formula (Ia) and a repeat unit of general formula (Ib), [ka] The liquid composition of any one of embodiments XVII-XXII, wherein the content of repeat units of general formula (Ib) is less than 20 wt %, preferably less than 18 wt %, more preferably less than 16 wt %, more preferably less than 14 wt %, more preferably less than 12 wt %, and most preferably less than 10 wt %, and the content of repeat units of general formula (Ia) is greater than 80 wt %, more preferably greater than 82 wt %, more preferably greater than 84 wt %, more preferably greater than 86 wt %, more preferably greater than 88 wt %, and most preferably at least 90 wt %, in each case based on the total weight of the functionalized π-conjugated polythiophene, and the content of repeat units of general formula (Ia) and the content of repeat units of general formula (Ib) preferably add up to 100 wt %.

[0035] XXIV. The liquid composition according to embodiment XXIII, wherein the content of the repeating unit of general formula (Ib) is at least 0.2 wt %, preferably at least 1 wt %, and more preferably at least 2 wt %, in each case based on the total weight of the functionalized π-conjugated polythiophene.

[0036] XXV. 1. A process for producing a liquid composition comprising a functionalized π-conjugated polythiophene, said process comprising: i) a) thiophene monomers of general formula (I), [ka] wherein X, Y, and A are as defined in embodiments I, III, IV, and V, and the liquid phase comprises a mixture of thiophene monomers of general formula (Ia) and thiophene monomers of general formula (Ib), [ka] thiophene monomers of general formula (I), wherein the content of thiophene monomers of general formula (Ib) is less than 20 wt %, preferably less than 18 wt %, more preferably less than 16 wt %, more preferably less than 14 wt %, more preferably less than 12 wt %, and most preferably less than 10 wt %, and the content of thiophene monomers of general formula (Ia) is more than 80 wt %, more preferably more than 82 wt %, more preferably more than 84 wt %, more preferably more than 86 wt %, more preferably more than 88 wt %, and most preferably more than 90 wt %, in each case based on the total weight of thiophene monomers in the liquid phase, and wherein the content of thiophene monomers of general formula (Ia) and the content of thiophene monomers of general formula (Ib) preferably add up to 100 wt %, b) an oxidizing agent, and c) Solvent providing a liquid phase comprising: ii) oxidatively polymerizing the thiophene monomers of general formula (Ia) and (Ib) to obtain a liquid composition comprising a functionalized π-conjugated polythiophene; The process includes:

[0037] XXVI. The process according to embodiment XXV, wherein the content of the thiophene monomer of general formula (Ib) is at least 0.2 wt. %, preferably at least 1 wt. %, more preferably at least 2 wt. %, in each case based on the total weight of the thiophene monomers in the liquid phase.

[0038] XXVII. A liquid composition obtainable by the process of embodiment XXV or XXVI.

[0039] XXVIII. A liquid composition comprising a functionalized π-conjugated polythiophene, the polythiophene comprising repeat units of general formula (I): [ka] wherein X, Y, and A are as defined in embodiments I, III, IV, and V, and the functionalized π-conjugated polythiophene comprises a repeat unit of general formula (Ia) and a repeat unit of general formula (Ib): [ka] the content of repeating units of general formula (Ib) is less than 20 wt %, preferably less than 18 wt %, more preferably less than 16 wt %, more preferably less than 14 wt %, more preferably less than 12 wt %, and most preferably less than 10 wt %, and the content of repeating units of general formula (Ia) is greater than 80 wt %, more preferably greater than 82 wt %, more preferably greater than 84 wt %, more preferably greater than 86 wt %, more preferably greater than 88 wt %, and most preferably greater than 90 wt %, in each case based on the total weight of the functionalized π-conjugated polythiophene, and the content of repeating units of general formula (Ia) and the content of repeating units of general formula (Ib) preferably total 100 wt %.

[0040] XXIX. The liquid composition according to embodiment XXVIII, wherein the content of repeating units of general formula (Ib) is at least 0.2 wt %, preferably at least 1 wt %, and more preferably at least 2 wt %, in each case based on the total weight of the functionalized π-conjugated polythiophene.

[0041] XXX. The liquid composition of any one of embodiments XVI-XXIV and XXVII-XXIX, wherein the conductive layer produced by the liquid composition has a conductivity greater than 12 S / cm.

[0042] XXXI. 1. A process for manufacturing a capacitor, the process comprising: I) preparing an electrode body of an electrode material, wherein a dielectric material at least partially covers one surface of the electrode material under the formation of an anode body; II) introducing a liquid composition according to any one of embodiments XVI to XXIV and XXVII to XXX into at least a portion of the electrode body; The process includes:

[0043] XXXII. A capacitor obtained by the process described in embodiment XXXI.

[0044] XXXIII. Use of the liquid composition according to any one of embodiments XVI to XXIV and XXVII to XXX for preparing a conductive layer in an electronic device.

[0045] XXXIV. The use of embodiment XXXIII, wherein the device is selected from a photoconductive cell, a photoresistor, a photoswitch, a phototransistor, a phototube, an IR detector, a photovoltaic device, a solar cell, a coating for a memory storage device, a field effect resistive device, an antistatic film, a biosensor, an electrochromic element, a solid electrolytic capacitor, an energy storage device, a touch panel, and an electromagnetic wave shield.

[0046] XXXV. The use of embodiment XXXIII, wherein the conductive layer is a solid electrolyte layer in a solid electrolytic capacitor.

[0047] A contribution to solving these objectives is a first process for preparing a liquid composition comprising a functionalized π-conjugated polythiophene, said process comprising: i) a) Thiophene monomers of general formula (I) [ka] (In the formula, X and Y are the same or different and are O, S, or NR 1 where R 1 is hydrogen or an aliphatic or aromatic residue having 1 to 18 carbon atoms, A is an anionic functional group, preferably -CO2 - , -SO3 - and -OSO3 - an organic residue having an anionic functional group selected from the group consisting of -SO3 - is particularly preferred) b) an oxidizing agent, and c) Solvent providing a liquid phase comprising: ii) oxidatively polymerizing the thiophene monomer of general formula (I) to obtain a liquid composition comprising a functionalized π-conjugated polythiophene; where: (α1) the pH of the liquid phase provided in process step i) is adjusted to a value less than 7.0, preferably less than 6.0, more preferably less than 5.0, more preferably less than 4.0, more preferably less than 3.0, more preferably less than 2.0, most preferably less than 1.0, said pH being determined at a temperature of 20°C; (α2) the chloride content of the liquid phase provided in process step i) is less than 10,000 ppm, more preferably less than 5,000 ppm, more preferably less than 1,000 ppm, more preferably less than 500 ppm, and most preferably less than 100 ppm, in each case based on the total weight of the liquid phase; It is done by process.

[0048] Surprisingly, it has been discovered that liquid compositions comprising functionalized π-conjugated polythiophenes (such as PEDOT-S) that allow the formation of conductive layers with increased conductivity can be prepared by oxidative polymerization of the corresponding monomers according to the process disclosed in EP 1 122 274 A1, provided that the pH of the monomer solution prior to the polymerization reaction is adjusted to a value below 7.0 and that the chlorine content in this monomer solution is maintained below 10,000 ppm.

[0049] In process step i) of the first process according to the invention, a liquid phase comprising thiophene monomers a), an oxidizing agent b) and a solvent c) is provided.

[0050] According to a first embodiment of the first process according to the invention, the thiophene monomers a) are those disclosed in EP 1 122 274 A1. According to a preferred embodiment of these thiophene monomers a), X and Y in general formula (I) are both oxygen (O), in particular: A is -(CH2) m -CR 2 R 3 -(CH2) n -where: R 2 is hydrogen or -(CH2) S -O-(CH2) p -SO3 - M + and R 3 is -(CH2) S -O-(CH2) p -SO3 - M + and M+ is a cation, preferably H + , Li + , Na + , K. + , Rb + , Cs + or NH4 + , particularly preferably Na + or K + and m and n may be the same or different and are integers of 0 to 3, preferably 0 or 1; s is an integer of 0 to 10, preferably 0 or 1; p is an integer of 1 to 18, preferably 4 or 5.

[0051] In this context, it is even more preferable that: A is -(CH2)-CR 2 R 3 -(CH2) n -where: R 2 is hydrogen, R 3 is -(CH2) S -O-(CH2) p -SO3 - M + and M + Na + or K + and n is 0 or 1, s is 0 or 1, p is 4 or 5.

[0052] The most preferred functionalized π-conjugated polythiophene in connection with the first embodiment of the process according to the present invention is poly(4-(2,3-dihydrothieno[3,4-b][1,4]dioxin-2-ylmethoxy)-1-butanesulfonic acid) (PEDOT-S), and therefore the most preferred thiophene monomer a) is 4-(2,3-dihydrothieno[3,4-b][1,4]dioxin-2-ylmethoxy)-1-butanesulfonic acid (EDOT-S). However, the EDOT-S monomer used for the preparation of PEDOT-S may contain a specific amount of PRODOT-S (4-(3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepin-3-yl)-1-butanesulfonic acid), as disclosed in EP 1 564 250 A1. According to a second embodiment of the first process according to the invention, the thiophene monomer a) is one disclosed in JP 2014-028760 A. In this regard, therefore, in the general formula (I): X and Y are O, A is —(CH—CHR)—, where R is -(CH2) t -O-Ar-[(W) u -SO3 - M + ] v where: Ar is an optionally substituted C6-C 20 represents an arylene group, W represents an optionally substituted C1-C6 alkylene group; M + is H + , Li + , Na + , and K. + an alkali cation selected from the group consisting of NH(R 1 )3 or HNC5H5, where each R 1 groups independently represent a hydrogen atom or an optionally substituted C1-C6 alkyl group; t represents an integer of 0 to 6, u represents an integer of 0 or 1; v represents an integer between 1 and 4 It is preferable.

[0053] In this regard, particularly preferred thiophene monomers are those explicitly mentioned in paragraph

[0049] of JP 2014-028760 A.

[0054] The oxidation reaction carried out in process step ii) can be catalyzed by a chemical oxidant, by electrochemical oxidation or by a combination of both methods. In the case of electrochemical oxidation, the electrode functions as an oxidant b).

[0055] Suitable oxidizing agents b) used as chemical oxidizing agents include salts of heavy metals, preferably iron salts, more preferably FeCl3 and iron(III) salts of aromatic and aliphatic sulfonic acids, HO, KCrO7, salts of peroxodisulfuric acid, such as KSO8, NaSO8, KMnO4, alkali metal perborates, and alkali metal or ammonium peroxodisulfate, or mixtures of these oxidizing agents. Particularly preferred are salts of heavy metals, salts of peroxodisulfuric acid, or mixtures thereof. Further suitable oxidizing agents are described, for example, in Handbook of Conducting Polymers (Ed. Skotheim, TA), Marcel Dekker: New York, 1986, Vol. 1, pp. 46-57. Particularly preferred oxidizing agents b) are mixtures of peroxodisulfuric acid salts with at least one further compound that catalyzes the cleavage of peroxodisulfuric acid, such as peroxodisulfuric acid salts, in particular KSO, NaSO, iron salts, in particular iron(III) chloride, or mixtures of peroxodisulfuric acid salts with iron salts. However, taking into account requirement (α2), the chloride content of the liquid phase provided in process step i) is less than 10,000 ppm, and these oxidizing agents b) preferably do not contain chlorine at all or contain such a low content of chlorine that requirement (α2) is still met. According to a particularly preferred embodiment of the process according to the invention, the oxidizing agent is a mixture of Fe(SO) and NaSO.

[0056] Suitable solvents c) that can be used in the first process according to the present invention include water, water-miscible solvents, especially those selected from the group consisting of aliphatic alcohols such as methanol, ethanol, isopropanol, and butanol, diacetone alcohol, ethylene glycol, and glycerol, aliphatic ketones such as acetone and methyl ethyl ketone, and aliphatic nitriles such as acetonitrile, or mixtures of at least two of these solvents, especially mixtures of water and water-miscible solvents. However, the most preferred solvent is water. Thus, in the case of 4-(2,3-dihydrothieno[3,4-b][1,4]dioxin-2-ylmethoxy)-1-butanesulfonic acid (EDOT-S) as the thiophene monomer a), the first process according to the present invention allows for the production of an aqueous PEDOT-S solution.

[0057] The concentration of the thiophene monomer a) in the aqueous phase provided in process step i) is preferably in the range of 0.1 to 25 wt %, preferably in the range of 0.5 to 10 wt %.

[0058] There are various ways to prepare the liquid phase provided in process step i). Thiophene monomer a) can be dissolved or dispersed in solvent c), followed by the addition of oxidizing agent b) (which can also be dissolved or dispersed separately in a solvent), or oxidizing agent b) can be first dissolved or dispersed in solvent c), followed by the addition of thiophene monomer a) (which can also be dissolved or dispersed separately in a solvent). When more than one oxidizing agent is used, such as a mixture of Fe2(SO4)3 and Na2S2O8, it is also possible to first mix one of the components with thiophene monomer a) and solvent c), and finally add the second oxidizing agent.

[0059] Regardless of the means by which the liquid phase is prepared in process step i), it is particularly preferred to reduce the oxygen content in the ingredients used to prepare the liquid phase to such an extent that the oxygen content in the liquid phase is less than 1000 ppm, more preferably less than 500 ppm, more preferably less than 100 ppm, more preferably less than 10 ppm, more preferably less than 1 ppm, more preferably less than 0.5 ppm, and most preferably less than 0.25 ppm, in each case based on the total weight of the liquid phase. According to a particularly preferred embodiment of the process of the present invention, the ingredients used to prepare the liquid phase are completely free of oxygen (i.e. the oxygen content is 0 ppm).

[0060] The reduction of the oxygen content can be achieved, for example, by stirring the ingredients used to prepare the liquid phase under reduced pressure, by using ultrasound, or by degassing these ingredients using an inert gas such as N, argon, CO or mixtures thereof, or by a combination of the above techniques.

[0061] The polymerization reaction in process step ii) is preferably carried out at a temperature ranging from -20°C to 200°C, preferably from 0°C to 100°C, for a period of preferably from 1 to 48 hours, more preferably from 5 to 20 hours.

[0062] After the polymerization reaction is complete, the liquid composition comprising the aqueous solution of the functionalized π-conjugated polymer, preferably PEDOT-S, can be further purified, for example, by filtration, in particular by ultrafiltration, and / or by treatment with ion exchangers, in particular anion and cation exchangers, in a further process step iii) for the purpose of further purification. It is also possible to add further additives as described below in connection with the process for producing a capacitor.

[0063] Furthermore, since the functionalized π-conjugated polythiophene obtained after polymerization in process step ii) is usually present in the form of particles, the particle size distribution of the functionalized π-conjugated polythiophene in the liquid composition obtained in process step ii) or the particle size distribution after further purification obtained in process step iii) can be adjusted by treating the liquid composition with ultrasound, wherein the energy input is preferably 10 to 1000 watts per liter (W / l), more preferably 20 to 500 W / l, and the ultrasonic frequency is preferably 10 to 1000 W / l, ... liquid composition is preferably homogenized by high-pressure homogenization. The pressure may be adjusted by treating the liquid composition with a pressure of preferably 20-200 kHz and greater than 100 bar, preferably greater than 500 bar, more preferably greater than 1500 bar, more preferably greater than 2500 bar, more preferably greater than 3500 bar, and most preferably greater than 4500 bar, preferably applied multiple times, or by treating the liquid composition with heat, wherein the heat treatment comprises treating the liquid composition at a temperature preferably in the range of 40-100°C, preferably in the range of 50-95°C, for 5 minutes to 100 hours, preferably 1-10 hours, more preferably 2-8 hours.

[0064] The first process according to the invention comprises: (α1) the pH of the liquid phase provided in process step i) is adjusted to a value of less than 7.0, preferably less than 6.0, more preferably less than 5.0, more preferably less than 4.0, more preferably less than 3.0, more preferably less than 2.0, most preferably less than 1.0, the pH being determined at a temperature of 20° C., (α2) The chloride content of the liquid phase provided in process step i) is characterized in that it is less than 10 000 ppm, preferably less than 5 000 ppm, more preferably less than 1 000 ppm, more preferably less than 500 ppm and most preferably less than 100 ppm, in each case based on the total weight of the aqueous phase.

[0065] Taking into account the requirement defined in (α2), adjusting the pH value to a value of less than 7.0 as defined in requirement (α1) is preferably achieved using an inorganic or organic acid, preferably an organic or inorganic acid substantially free of chloride. Suitable organic acids include carboxylic acids such as formic acid, acetic acid, lactic acid, propionic acid, citric acid, malic acid, fumaric acid, or mixtures thereof. Suitable inorganic acids are, in particular, sulfuric acid, sulfonic acid, nitric acid, phosphonic acid, phosphoric acid, or mixtures thereof. It is also possible to use these co-acids in combination with one of the above-mentioned organic or inorganic chloride-free acids, as long as the chloride-containing co-acid, such as hydrochloric acid, is used in such a low amount that requirement (α2) is still met. According to a particularly preferred embodiment of the process according to the invention, sulfuric acid is used to adjust the pH.

[0066] Adjusting the chloride content of the liquid phase provided in process step i) to be less than 10,000 ppm as defined in requirement (α2) is preferably achieved by selecting components a), b) and c), in particular by selecting an oxidizing agent b) that is substantially chloride-free. If necessary, the chloride content of the components used to prepare the liquid phase can be further reduced by treatment of these components with an anion exchanger.

[0067] According to a particularly preferred embodiment of the first process according to the invention, (α3) It is also advantageous that the oxygen content of the liquid phase provided in process step i) is less than 1000 ppm, preferably less than 500 ppm, more preferably less than 100 ppm, more preferably less than 10 ppm, more preferably less than 1 ppm, more preferably less than 0.5 ppm, and most preferably less than 0.25 ppm, in each case based on the total weight of the liquid phase. According to a particularly preferred embodiment of the process according to the invention, the oxygen content of the liquid phase provided in process step i) is completely free of oxygen (i.e. the oxygen content is 0 ppm).

[0068] There are various ways to adjust the oxygen content in the liquid phase provided in process step i) and to maintain this low oxygen content during the polymerization reaction in process step ii).

[0069] According to one approach, the liquid phase prepared in process step i) (or the liquid composition used to prepare the liquid phase) can be degassed by introducing an inert gas, such as N, argon, CO, or a mixture thereof, into the liquid phase prepared in process step i) to reduce the initial oxygen content in the liquid phase. Alternatively, the liquid phase prepared in process step i) (or the liquid composition used to prepare the liquid phase) can be subjected to a treatment with reduced pressure to reduce the initial oxygen content, for example by stirring the liquid phase while applying a vacuum, or to a treatment with ultrasound, or to a combination of treatment with reduced pressure and ultrasound.

[0070] To ensure that a low oxygen content is maintained during the polymerization reaction in process step ii), it may be advantageous to carry out the polymerization reaction under an inert gas atmosphere, preferably under N, CO, argon, or a mixture of at least two of these inert gases, and it may also be advantageous for the oxidative polymerization in process step ii) to be carried out under a pressure equal to or greater than the vapor pressure of the liquid phase during the polymerization reaction in process step ii). Preferably, the oxidative polymerization in process step ii) is carried out under a pressure of at least 0.1 mbar, more preferably at least 0.5 mbar, and most preferably at least 1 mbar higher than the vapor pressure of the liquid phase during the polymerization reaction in process step ii). To ensure that a low oxygen content is maintained during the polymerization reaction in process step ii), the oxidative polymerization in process step ii) can also be carried out under reduced pressure, preferably at a pressure of 0.8 bar or less, most preferably at a pressure of 0.5 bar or less.

[0071] A contribution to achieving the above-mentioned objectives is also made by a liquid composition comprising a functionalized π-conjugated polythiophene, preferably by an aqueous PEDOT-S solution obtained by the first process according to the invention, preferably by a liquid composition comprising a functionalized π-conjugated polythiophene, in particular by an aqueous PEDOT-S solution obtained by the first process according to the invention.

[0072] A contribution to achieving the above-mentioned objectives is also made by a first liquid composition comprising a functionalized π-conjugated polythiophene, wherein the polythiophene comprises repeat units of the general formula (I): [ka] wherein X, Y and A are as defined in relation to the first process according to the invention. where the mass average molecular weight M of the functionalized π-conjugated polythiophene w relative to the molar average molecular weight M n The ratio (M w / M n ) is at least 6, in particular at least 8, more preferably at least 10, more preferably at least 12, more preferably at least 14, more preferably at least 16, more preferably at least 18, more preferably at least 20.

[0073] In the functionalized π-conjugated polythiophenes contained in the first liquid composition according to the present invention (but also in the functionalized π-conjugated polythiophenes contained in the second liquid composition according to the present invention described below), the repeat units of general formula (I) are linked to each other as shown in formula (I′) below: [ka] (wherein the asterisk ( * ) indicates a bond to an adjacent repeat unit.) Preferably, the functionalized π-conjugated polythiophene has positive charges along the polymer chain (not shown in general formula (I')), and these positive charges are at least partially balanced by anionic functional groups in the organic residue A.

[0074] Amazingly, at least 6 M w / M n It has been discovered that M values ​​of at least 6 are significantly useful in improving the properties of the functionalized π-conjugated polythiophenes, especially when the functionalized π-conjugated polythiophenes are used to form solid electrolytes in solid electrolytic capacitors. w / M n When a functionalized π-conjugated polythiophene such as PEDOT-S, which has a M value of about 4.4, is used, the solid electrolyte layer w / M n PEDOT-S (M w = 123000 g / mol and M n = 28000 g / mol) is disclosed in, for example, "PEDOT Principles an Applications of an Intrinsically Conductive Polymer", Elschner et al. (2011), Chapter 12.4 of CRC), an improved capacitor and a solid electrolyte having an improved ESR can be obtained compared to a solid electrolyte layer capacitor prepared using such a material. According to a preferred embodiment of the liquid composition of the present invention, M w / M n The value of is at most 100, preferably at most 75, more preferably at most 50.

[0075] Mass-average molecular weight M of functionalized π-conjugated polythiophenes w It is further preferred that the weight average molecular weight M of the functionalized π-conjugated polythiophene is at least 50,000 g / mol, preferably at least 75,000 g / mol, more preferably at least 100,000 g / mol, and most preferably at least 125,000 g / mol. w It has been shown that it is beneficial for the .sigma..sub.2 to be in the range of 125,000 g / mol to 240,000 g / mol, preferably in the range of 125,000 g / mol to 210,000 g / mol.

[0076] Furthermore, the molar average molecular weight M of the functionalized π-conjugated polythiophene nis preferably less than 25,000 g / mol, preferably less than 20,000 g / mol, more preferably less than 15,000 g / mol.

[0077] As mentioned above, the functionalized π-conjugated polythiophene, especially when prepared by the first process according to the present invention, is usually present in the form of particles. In this regard, the particle size distribution of these particles is i) d in the range of 1 to 100 nm, preferably in the range of 1 to 80 nm, more preferably in the range of 1 to 60 nm, and most preferably in the range of 5 to 40 nm 50 value (weight average particle size), and ii) 3.5 × d 50 Less than 3 × d 50 less than 2 × d 50 Less than d 90 value It is particularly preferred that the temperature is characterized by:

[0078] M w , M n and M w / M n With regard to the first liquid composition according to the present invention comprising a functionalized π-conjugated polythiophene having the above-defined values ​​for [ka] Here, it is preferred that the content of repeating units of general formula (Ib) is less than 20 wt%, preferably less than 18 wt%, more preferably less than 16 wt%, more preferably less than 14 wt%, more preferably less than 12 wt%, and most preferably less than 10 wt%, and the content of repeating units of general formula (Ia) is in each case greater than 80 wt%, more preferably greater than 82 wt%, more preferably greater than 84 wt%, more preferably greater than 86 wt%, more preferably greater than 88 wt%, and most preferably greater than 90 wt%, based on the total weight of the functionalized π-conjugated polythiophene, and that the content of repeating units of general formula (Ib) and the content of repeating units of general formula (Ia) add up to 100 wt% (i.e., the functionalized π-conjugated polythiophene consists only of these two repeating units). In this regard, it is further preferred that the content of repeating units of general formula (Ib) is in each case at least 0.2 wt%, preferably at least 1 wt%, more preferably at least 2 wt%, based on the total weight of the functionalized π-conjugated polythiophene. The relative contents of repeating units of general formulae (Ia) and (Ib) in the functionalized π-conjugated polythiophene can be adjusted using a liquid phase containing the corresponding monomers in appropriate relative amounts and by oxidatively polymerizing these monomers according to the process according to the invention.

[0079] Also contributing to achieving the above objectives is a second process for producing a liquid composition comprising a functionalized π-conjugated polythiophene, the process comprising: i) a) thiophene monomers of general formula (I), [ka] wherein X, Y and A are as defined above. the liquid phase comprises a mixture of thiophene monomers of general formula (Ia) and thiophene monomers of general formula (Ib), [ka] thiophene monomers of general formula (I), wherein the content of thiophene monomers of general formula (Ib) is less than 20 wt. %, preferably less than 18 wt. %, more preferably less than 16 wt. %, more preferably less than 14 wt. %, more preferably less than 12 wt. %, and most preferably less than 10 wt. %, and the content of thiophene monomers of general formula (Ia) is more than 80 wt. %, more preferably more than 82 wt. %, more preferably more than 84 wt. %, more preferably more than 86 wt. %, more preferably more than 88 wt. %, and most preferably more than 90 wt. %, in each case based on the total weight of the thiophene monomers in the liquid phase, and the content of thiophene monomers of general formula (Ia) and the content of thiophene monomers of general formula (Ib) preferably add up to 100 wt. %; b) an oxidizing agent; c) a solvent; providing a liquid phase comprising: ii) oxidatively polymerizing thiophene monomers of general formulas (Ia) and (Ib) to obtain a liquid composition comprising a functionalized π-conjugated polythiophene; This is done by a process that includes

[0080] Surprisingly, it has also been discovered that when functionalized π-conjugated polythiophenes are used to form a solid electrolyte layer in a solid electrolytic capacitor prepared with thiophene monomers containing less than 20 wt% of thiophene monomers of general formula (Ib) and more than 80 wt% of thiophene monomers of general formula (Ia), the capacitor's characteristics in terms of capacitance and ESR can be significantly improved. As described above, the EDOT-S monomer (repeating unit of general formula (Ia)) used to prepare PEDOT-S can contain a specific amount of PRODOT-S (repeating unit of general formula (Ib)), as disclosed in EP 1564250 A1. Adjusting the PRODOT-S content to a value less than 20 wt%, preferably 0.1 to 14 wt%, more preferably 1 to 12 wt%, and even more preferably 2 to 10 wt%, has been shown to be particularly beneficial when such functionalized π-conjugated polythiophenes are used to form a solid electrolyte layer in a solid electrolytic capacitor. In this regard, it is also preferred that the content of thiophene monomers of general formula (Ib) is in each case at least 0.2 wt. %, preferably at least 1 wt. %, more preferably at least 2 wt. %, based on the total weight of thiophene monomers in the liquid phase.

[0081] Preferred solvents and oxidizing agents are those mentioned in connection with the first process according to the invention.

[0082] A contribution to achieving the above-mentioned objectives is also achieved by a liquid composition comprising a functionalized π-conjugated polythiophene, preferably by an aqueous PEDOT-S solution obtained by the second process according to the invention, preferably by a liquid composition comprising a functionalized π-conjugated polythiophene, in particular by an aqueous PEDOT-S solution obtained by the second process according to the invention.

[0083] Also contributing to achieving the above objectives is a second liquid composition comprising a functionalized π-conjugated polythiophene, the polythiophene comprising repeat units of the general formula (I): [ka] where X, Y and A are as defined for the first process according to the invention. wherein the functionalized π-conjugated polythiophene comprises a repeat unit of general formula (Ia) and a repeat unit of general formula (Ib): [ka] The content of repeating units of general formula (Ib) is less than 20 wt%, preferably less than 18 wt%, more preferably less than 16 wt%, more preferably less than 14 wt%, more preferably less than 12 wt%, and most preferably less than 10 wt%, and the content of repeating units of general formula (Ia) is in each case greater than 80 wt%, more preferably greater than 82 wt%, more preferably greater than 84 wt%, more preferably greater than 86 wt%, more preferably greater than 88 wt%, and most preferably greater than 90 wt%, based on the total weight of the functionalized π-conjugated polythiophene, and the content of repeating units of general formula (Ib) and the content of repeating units of general formula (Ia) preferably total 100% (i.e., the functionalized π-conjugated polythiophene consists of only these two repeating units). In this context, it is also preferred that the content of repeating units of general formula (Ib) is in each case at least 0.2 wt %, preferably at least 1 wt %, more preferably at least 2 wt %, based on the total weight of the functionalized π-conjugated polythiophene.

[0084] In this context, the liquid composition obtained by the first or second process according to the invention, well-defined M w / M nIt is particularly preferred that conductive layers made with a first liquid composition according to the present invention comprising a functionalized π-conjugated polythiophene having a value of 0.1 to 1.0, and a second liquid composition according to the present invention comprising a functionalized π-conjugated polythiophene comprising well-defined relative amounts of repeat units of general formulae (Ia) and (Ib) have a conductivity of more than 12 S / cm, preferably more than 14 S / cm, more preferably more than 16 S / cm, preferably more than 18 S / cm, more preferably more than 20 S / cm, more preferably more than 25 S / cm, more preferably more than 40 S / cm, more preferably more than 60 S / cm, and most preferably more than 80 S / cm.

[0085] Also contributing to achieving the above objectives is a process for manufacturing a capacitor, the process comprising: I) preparing an electrode body of an electrode material, wherein a dielectric material at least partially covers one surface of the electrode material under formation of the electrode body; II) Liquid compositions obtained by the first or second process according to the invention, well-defined M w / M n introducing into at least a portion of the electrode body a first liquid composition according to the present invention comprising a functionalized π-conjugated polythiophene having a value of 0.05 or a second liquid composition according to the present invention comprising a functionalized π-conjugated polythiophene comprising well-defined relative amounts of repeat units of general formulas (Ia) and (Ib); This is done by a process that includes

[0086] In process step I) an electrode body of electrode material is first prepared, with a dielectric covering at least partly one surface of this electrode material to form the anode body.

[0087] In principle, the electrode body is manufactured by pressing and sintering a high-surface-area valve metal powder, usually resulting in a porous electrode body. An electrical connection wire, preferably made of a valve metal such as tantalum, is also customarily pressed onto the electrode body. The electrode body is then coated with a dielectric, i.e., an oxide layer, for example, by electrochemical oxidation. Alternatively, a metal foil may also be etched to obtain an anode foil with a porous region, and then coated with a dielectric by electrochemical oxidation. In a wound capacitor, the anode and cathode foils with porous regions that form the electrode body are separated by a separator and wound.

[0088] In the context of this invention, valve metals are understood to mean those metals whose oxide layer does not allow current to flow equally well in both directions. When a voltage is applied to the anode, the oxide layer of the valve metal blocks the current, while when a voltage is applied to the cathode, a large current can be generated that can destroy the oxide layer. Valve metals include Be, Mg, Al, Ge, Si, Sn, Sb, Bi, Ti, Zr, Hf, V, Nb, Ta, and W, as well as alloys or compounds of at least one of these metals with other elements. The best-known representatives of valve metals are Al, Ta, and Nb. Compounds with electrical properties corresponding to valve metals are those with metallic conductivity that can be oxidized, and their oxide layers have the above-mentioned properties. For example, NbO has metallic conductivity, but is not generally considered a valve metal. However, since a layer of oxidized NbO has the typical properties of a valve metal oxide layer, NbO or alloys or compounds of NbO with other elements are typical examples of such compounds with electrical properties corresponding to valve metals. Tantalum, aluminum electrode materials and those based on niobium or niobium oxide are preferred. Tantalum and aluminum are very particularly preferred as electrode materials.

[0089] In many cases, for the manufacture of electrode bodies having porous regions, valve metals can be sintered, for example in powder form, to typically obtain porous electrode bodies, or the porous structure can be stamped into the metal body, the latter of which can be performed, for example, by etching a foil.

[0090] For simplicity, a body having a porous region will also be referred to as porous hereinafter. Thus, for example, an electrode body having a porous region will also be referred to as a porous electrode body. On the other hand, the porous body may have multiple channels and thus be sponge-like. This is often the case when tantalum is used to construct a capacitor. Furthermore, only the surface may have pores, and the region below the surface pores may be solid in structure. This situation is often observed when aluminum is used to construct a capacitor. Preferably, the electrode body is porous.

[0091] In many cases, the porous electrode body thus produced is then oxidized in a suitable electrolyte, such as aqueous phosphoric acid or ammonium adipate, by applying a voltage to form a dielectric. The level of this formation voltage depends on the thickness of the oxide layer to be achieved and the subsequent use voltage of the capacitor. Preferred formation voltages are in the range of 1 to 1000 V, particularly preferably in the range of 2 to 500 V, and very particularly preferably in the range of 1 to 300 V. According to a first specific embodiment of the process for producing a capacitor, the formation voltage is in the range of 1 to 20 V, while according to a second specific embodiment of the process for producing a capacitor, the formation voltage is in the range of 30 to 100 V.

[0092] In general, the porous electrode body used preferably has a porosity of 10 to 90%, preferably 30 to 80%, particularly preferably 50 to 80%, and an average pore size of 10 to 10,000 nm, preferably 20 to 5,000 nm, particularly preferably 50 to 3,000 nm.

[0093] According to a specific embodiment of the process of the present invention, the electrolytic capacitor produced is an aluminum-wound capacitor. In this case, in process step a), a porous aluminum foil is formed as the anode electrode material, and an aluminum oxide coating is formed as the dielectric. The resulting aluminum foil (anode foil) is then provided with a contact wire and wound with an optional additional porous aluminum foil (cathode foil) also provided with a contact wire, with the two foils separated from each other by one or more separators, for example, based on cellulose or preferably synthetic paper. After winding, the resulting anode body is fixed, for example, with adhesive tape. The separator or separators can be carbonized by heating in an oven. This method and means for producing an anode body for an aluminum-wound capacitor are well known in the prior art and are described, for example, in U.S. Pat. No. 7,497,879 B2.

[0094] According to a more particular embodiment of the process according to the invention, the electrolytic capacitors produced are aluminum laminate capacitors or tantalum electrolytic capacitors ("tantalum elco"), in particular tantalum electrolytic capacitors with a polymer outer layer as described in DE 10 2009 007 594 A1.

[0095] In process step II) of the process according to the invention, the liquid composition obtained by the first or second process according to the invention, a well-defined M w / M nA first liquid composition according to the present invention, comprising a functionalized π-conjugated polythiophene having a value of 0.1 or a second liquid composition according to the present invention, comprising a functionalized π-conjugated polythiophene having well-defined relative amounts of repeating units of the general formulae (Ia) and (Ib), preferably an aqueous solution of PEDOT-S, is introduced onto at least a portion of the anode body. In this context, it should be noted that before introducing the liquid composition obtained by the first or second process according to the present invention, or the first or second liquid composition according to the present invention, onto at least a portion of the anode body, another composition may be introduced onto the anode body to form a conductive layer, such as a PEDOT / PSS dispersion. Therefore, it is not necessarily necessary to apply the liquid composition obtained by the first or second process according to the present invention, or the first or second liquid composition according to the present invention, directly onto at least a portion of the dielectric layer of the anode body.

[0096] The liquid composition is introduced into the porous region by known processes, such as impregnation, dipping, pouring, dripping, spraying, atomizing, knife coating, brushing, or printing, such as inkjet, screen, or tampon printing. Preferably, the introduction is carried out by immersing the anode body prepared in process step a) in the liquid composition, thereby impregnating it with this liquid composition. Immersion in or impregnation with the liquid composition is preferably carried out for a time in the range of 1 second to 120 minutes, particularly preferably in the range of 5 seconds to 60 minutes, and most preferably in the range of 10 seconds to 15 minutes. The introduction of the liquid composition into the anode body can be promoted, for example, by increasing or decreasing the pressure, vibration, ultrasound, or heating.

[0097] The liquid composition employed in process step II) may, besides the remainder of the functionalized π-conjugated polymer a), the solvent c) and optionally the oxidizing agent b) in its reduced form, contain further additives such as surface-active substances, for example anionic surfactants such as alkylbenzenesulfonic acids and salts, paraffin sulfonates, alcohol sulfonates, ether sulfonates, sulfosuccinates, phosphate esters, alkyl ether carboxylic acids or carboxylates, cationic surfactants, for example quaternary alkylammonium salts, nonionic surfactants such as linear alcohol ethoxylates, oxoalcohol ethoxylates, alkylphenol ethoxylates or alkylpolyglucosides, in particular those under the trade names Dynol® and Zonyl® The dispersion may further comprise surfactants, commercially available under the trademarks GL-1000, or adhesion promoters, such as organofunctional silanes or hydrolysates thereof, for example 3-glycidoxypropyltrialkoxysilane, 3-aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane or octyltriethoxysilane, crosslinkers, for example melamine compounds, masked isocyanates, for example tetraethoxysilane, functional silanes based on epoxysilanes, for example tetraethoxysilane, alkoxysilane hydrolysates, for example 3-glycidoxypropyltrialkoxysilane-polyurethane, polyacrylate or polyolefin dispersions.

[0098] Preferably, the liquid composition employed in process step II) optionally comprises further additives that increase the conductivity, such as compounds containing an ether group, such as tetrahydrofuran, compounds containing a lactone group, such as γ-butyrolactone, γ-valerolactone, compounds containing an amide or lactam group, such as caprolactam, N-methylcaprolactam, N,N-dimethylacetamide, N-methylacetamide, N,N-dimethylformamide (DMF), N-methylformamide, N-methylformanilide, N-methylpyrrolidone (NMP), N-octylpyrrolidone, pyrrolidone, sulfones and sulfoxides, such as sulfolane (tetramethylene sulfone), dimethyl sulfoxide (DMSO), sugars or sugar derivatives, such as sucrose, glucose, fructose, lactose, sugar alcohols, such as sorbitol, mannitol, furan derivatives, such as 2-furancarboxylic acid, 3-furancarboxylic acid, glycerol, diglycerol, triglycerol or tetraglycerol.

[0099] The liquid composition utilized in process step II) may further comprise, as an additive, one or more organic binders soluble in organic solvents, as described in WO 2009 / 141209 A1, page 12, lines 16-34. The liquid composition used to prepare the solid electrolyte layer may have a pH of 1 to 14, with a pH of 1 to 8 being preferred. For example, for corrosion-sensitive dielectrics such as aluminum oxide or niobium oxide, a liquid composition having a pH of 2.5 to 8 is preferred to avoid damaging the dielectric.

[0100] To adjust the pH, a base or an acid may be added as an additive to the liquid composition utilized in process step II), as described, for example, in WO 2010 / 003874 A2, page 4, lines 13-32. Preferred are additives that do not affect the film formation of the liquid composition and that do not volatilize at high temperatures, such as soldering temperatures, but remain present in the solid electrolyte under these conditions, such as basic 2-dimethylaminoethanol, 2,2'-iminodiethanol, or 2,2',2''-nitrilotriethanol and acidic polystyrene sulfonic acid.

[0101] The viscosity of the liquid composition utilized in process step II) is between 0.01 and 1000 mPa·s (at 20°C and 100°C), depending on the application method. -1 The viscosity may be in the range of 1 to 500 mPa·s, particularly preferably 1 to 250 mPa·s. In the case of the production of aluminum wound capacitors, the viscosity is very particularly preferably in the range of 1 to 200 mPa·s, while in the case of the production of tantalum electrolytic capacitors or aluminum multilayer capacitors, the viscosity is very particularly preferably in the range of 1 to 50 mPa·s. Adjustment of the viscosity can be achieved, for example, by adding suitable rheology modifiers as further additives.

[0102] The solids content of the liquid composition employed in process step II) is preferably in the range of 0.01 to 20 wt. %, particularly preferably in the range of 0.1 to 15 wt. %, most preferably in the range of 0.25 to 10 wt. %, in each case based on the total weight of the liquid composition. The solids content of the liquid composition is determined by drying the liquid composition at a temperature high enough to remove the solvent c).

[0103] According to a particularly preferred embodiment of the process for producing a capacitor according to the invention, the liquid composition introduced into the capacitor body not only comprises a functionalized π-conjugated polymer, but also, in addition to this self-doped conductive polymer, an exogenously doped conductive polymer, preferably PEDOT / PSS, as disclosed in WO 2014 / 048562 A2. The disclosure of WO 2014 / 048562 A2 regarding the combined use of a self-doped polymer such as PEDOT-S and an exogenously doped polymer such as PEDOT / PSS for the formation of a solid electrolyte is incorporated herein by reference and forms part of the disclosure of the present application.

[0104] Advantageously, after the anode body has been impregnated with the liquid composition obtained by the first or second process according to the invention or with the first or second liquid composition according to the invention described above, the solvent c) contained in the liquid composition is at least partially removed in a subsequent process step III), so that the solid electrolyte completely or partially covers the dielectric, thereby forming the capacitor body. In this context, the coverage of the dielectric with the solid electrolyte is preferably at least 10%, particularly preferably at least 25%, and most preferably at least 50%, and the coverage can be determined by measuring the capacitance of the capacitor in the dry and humid state at 120 Hz, as described in DE 10 2005 043 828 A1.

[0105] The removal or curing is preferably carried out by removing the electrode body from the liquid composition and drying it, the drying being preferably carried out at a temperature in the range of 20°C to 260°C, particularly preferably in the range of 50°C to 220°C, and most preferably in the range of 80°C to 200°C. Of course, it is also possible to at least partially remove the solvent c) by freeze-drying. Process steps II) and III) may also be repeated once or several times in order to thus adapt the thickness of the layer of solid electrolyte deposited on the dielectric or the degree of electrolyte filling in the electrode body to specific requirements.

[0106] After the capacitor bodies are produced in this way, they may be further modified by methods and means known to those skilled in the art. In the case of tantalum electrolytic capacitors, the capacitor body may be coated with a polymer outer layer, as described in German Patent Application Publication No. 10 2004 022674 or German Patent Application Publication No. 10 2009 007 594, and / or with a graphite layer and a silver layer, as known from German Patent Application Publication No. 10 2005 043 828. In the case of aluminum-wound capacitors, the capacitor body is mounted in an aluminum beaker equipped with a sealing glass and mechanically sealed tightly by crimping, in accordance with the teachings of U.S. Patent No. 7,497,879 B2. The capacitor can then be freed from dielectric defects caused by aging in a known manner.

[0107] A contribution to achieving the above-mentioned objectives is also made by the capacitor obtained by the above-mentioned process, preferably the capacitor being a tantalum electrolytic capacitor or an aluminum capacitor, for example an aluminum stack capacitor or an aluminum wound capacitor.

[0108] A contribution to achieving the above-mentioned object can also be made by the use of a liquid composition obtained by the first or second process according to the invention, preferably by the first or second process according to the invention, for producing a conductive layer in an electronic device, or by the use of a liquid composition obtained by the first or second process according to the invention, or by the use of a well-defined M w / M nand the use of a first liquid composition according to the present invention comprising a functionalized π-conjugated polythiophene having a value of 1 to 100; and the use of a second liquid composition according to the present invention comprising a functionalized π-conjugated polythiophene comprising repeat units of the general formulae (Ia) and (Ib) in well-defined relative amounts, in an electronic device preferably selected from the group consisting of photoconductive cells, photoresistors, optical switches, phototransistors, phototubes, IR detectors, photovoltaic devices, solar cells, coatings for memory storage devices, field-effect resistance devices, antistatic films, biosensors, electrochromic elements, solid electrolytic capacitors, energy storage devices, touch panels, and electromagnetic shields. In this context, the liquid composition obtained by the first or second process according to the present invention, preferably the liquid composition obtained by the first or second process according to the present invention, the well-defined M w / M n It is particularly preferred that a first liquid composition according to the present invention, comprising a functionalized π-conjugated polythiophene having a value of 0.05 or a second liquid composition according to the present invention, comprising a functionalized π-conjugated polythiophene having recurring units of the general formulae (Ia) and (Ib) in well-defined relative amounts, be used to prepare a solid electrolyte layer of a solid electrolytic capacitor. In this context, in the process disclosed in WO 2014 / 048562 A2, the liquid composition obtained by the first or second process according to the present invention, preferably the liquid composition obtained by the first or second process according to the present invention, the well-defined M w / M n It is particularly preferred to use a first liquid composition according to the invention comprising a functionalized π-conjugated polythiophene having a value of 0.05 or a second liquid composition according to the invention comprising a functionalized π-conjugated polythiophene comprising well-defined relative amounts of repeat units of the general formulae (Ia) and (Ib).

[0109] The invention will now be explained in more detail using non-limiting figures and examples. [Brief explanation of the drawings]

[0110] [Figure 1]1 is a cross-sectional view of a portion of a capacitor obtained by a process according to the invention for producing a capacitor. It has an electrode body 1 made from a porous electrode material 2, typically aluminum. On the surface 4 of the electrode material 2, a dielectric 3 is formed as a thin layer, so that it is still porous, to form an anode body 5 comprising the electrode body 1 of the electrode material 2 and the dielectric 3. The dielectric 3 is followed by an optional further layer, a layer 6 of a solid electrolyte (e.g., a layer made using a liquid composition prepared by a process according to the invention), to form a capacitor body 7 comprising the electrode body 1 of the electrode material 2, the dielectric 3, and the solid electrolyte 6. DETAILED DESCRIPTION OF THE INVENTION

[0111] Test Method conductivity A cleaned glass substrate was placed on a spin coater, and 10 ml of the liquid composition according to the present invention was dispersed onto the substrate. The remaining solution was then drained off by rotating the plate. The thus-coated substrate was then dried on a hot plate at 130°C for 15 minutes. The layer thickness was then determined using a layer thickness measuring device (Tencor, Alphastep 500). The conductivity was determined by depositing a 2.5 cm long Ag electrode at a distance of 10 mm through a shadow mask. The specific resistance was obtained by multiplying the surface resistance, determined with an electrometer (Keithly 614), by the layer thickness. The conductivity is the reciprocal of the specific resistance.

[0112] oxygen content The oxygen content is measured using a Knick Portamess 911 Oxy (Knick Elektronische Messgerate GmbH & Co. KG, Beuckestraße 22, Berlin, Germany). Before the measurement, the instrument is calibrated against ambient air. To determine the oxygen content at the start of the reaction, the sensor is immersed under a nitrogen flow in the reaction solution.

[0113] Chloride Content The chloride content was determined by ion chromatography using the following equipment and measurement conditions: Equipment: Metrohm 882 Compact IC Plus (Metrohm AG, Ionenstrasse, CH-9100 Herisau, Switzerland) Software: Metrohm MagIC Net Column: Metrosep A Supp 5; particle size: 5 μm; length: 150-25 mm; diameter: 5 mm Preparation of eluent: Mix 3.2 ml of 1 mol / L sodium carbonate solution and 1 ml of sodium bicarbonate solution, and add 995.8 ml of pure water. Flow rate 0.7mL / min Temperature: room temperature

[0114] For calibration, the following standards are used: Chloride Standardlosung, 1.000 mg / l Cl - In water (with NaCl), ARISTAR® Standard for Ion Enchromatographies, VWR Product Code 458012Q, 100 mL (VWR International GmbH, Darmstadt). For calibration, a concentration series was prepared by diluting the standard with pure water to calibrate the ion chromatograph in the relevant range of 0.1 to 30 ppm. If the chloride content of the sample was higher than 30 ppm, the sample was diluted with pure water until the chloride concentration was within the calibration range. The chloride content of the original sample was calculated by multiplying this result by the dilution factor.

[0115] Equivalent series resistance (ESR) The equivalent series resistance (mΩ) was determined by an LCR meter (Agilent 4284A) at 100 kHz and 20° C. For each capacitor experiment, at least five capacitors were fabricated and the average ESR value was determined.

[0116] Capacitance (CAP) The capacitance (μF) was determined by an LCR meter (Agilent 4284A) at 120 Hz and 20° C. For each capacitor experiment, at least five capacitors were fabricated and the average capacitance value was determined.

[0117] M n and M w Mass average molecular weight M w and the molar average molecular weight M n is determined by gel permeation chromatography (GPC) using polystyrene sulfonic acid as the standard. A modular GPC system equipped with an HP 1100 1312 pump and three subsequent columns (MCX1.000, MCX100.000, and MCX10.000.000) was used in combination with an HP 1047a Ri detector. The eluent was water. The process temperature was set at 40 °C, and a flow rate of 0.5000 ml / min was applied. The calibration standard was polystyrene sulfonic acid. Prior to measurement, the PEDOT-S samples were filtered through a 0.45 μm cellulose acetate syringe filter.

[0118] Compositions of functionalized π-conjugated polythiophenes The relative amounts of monomer units of general formula (Ia) and (Ib) in the thiophene monomer used to prepare the liquid compositions comprising functionalized π-conjugated polythiophenes according to the present invention are determined by HPLC.

[0119] d 50 and d 90 Diameter distribution d 90 The value is that 90% of the total weight of all particles of functionalized π-conjugated polythiophene is d 90 Therefore, the d value of the diameter distribution can be assigned to those particles with diameters equal to or smaller than this value. 50 The value is that 50% of the total weight of all particles of functionalized π-conjugated polythiophene is d 50 It can be shown that the value of d can be assigned to those particles with a diameter equal to or less than the value of d 50 The values ​​represent the weight average particle size).

[0120] d 50 and d 90 The determination was carried out by ultracentrifugation measurements.

[0121] average Unless otherwise stated, the average corresponds to the arithmetic mean value. [Example]

[0122] For the preparation of PEDOT-S solutions as described below, the sodium salt of 4-(2,3-dihydrothieno-[3,4-b][1,4]dioxin-2-ylmethoxy)-1-butanesulfonic acid (EDOT-S) was prepared as described by Chevrot et al. (J. Electroanal. Chem. 1998, 443, 217-226) and utilized as the monomer.

[0123] Synthesis Example 1 (not according to the invention) A glass 3 L jacketed beaker is equipped with a mechanical stirrer, thermometer and nitrogen flow.

[0124] Ingredient A In this beaker, 243.6 g (0.9 mol) of iron(III) chloride was dissolved in 800 g of purified water, and nitrogen was bubbled through the solution for 30 minutes while stirring until the oxygen content was less than 0.25 mg / l.

[0125] Component B In a separate glass beaker, 100 g of EDOT-S sodium salt (0.29 mol) was dissolved in 1200 g of purified water. Nitrogen was bubbled through the solution through a flexible tube until the oxygen content was less than 0.25 mg / L.

[0126] Component B was added to Component A with stirring. The resulting mixture was heated to a maximum temperature of 90-95°C within 6 hours and maintained at this temperature for an additional 15 hours. After the reaction was complete, the reaction mixture was brought to a volume of 10 L by adding purified water, followed by ultrafiltration (Pall Microza SLP 1053 with a cutoff of 10,000 g / mol), thereby removing 8 L of water. This procedure was repeated six times to remove inorganic salts.

[0127] The resulting dispersion was characterized as having a conductivity of 0.05 S / cm and a solids content of 1.62 wt %.

[0128] Synthesis Example 2 (not according to the invention) The 3 L stainless steel jacketed tank is equipped with a mechanical stirrer, a ventilation valve in the upper lid, a closable material inlet and a thermometer.

[0129] Ingredient A Into this tank, 2000 g of pure water, 16.0 g of a 10 wt% aqueous solution of iron (III) sulfate, and 100 g of EDOT-S sodium salt (0.29 mol) were introduced. The agitator was operated at 50 rpm, the temperature was adjusted to 20 °C, and the internal pressure was reduced to 100 hPa. The pressure in the tank was then increased to atmospheric pressure, and then reduced to 25 hPa to further evacuate oxygen.

[0130] Component B In a separate glass beaker, 78.5 g of sodium peroxodisulfate was dissolved in 200 ml of water and the solution was bubbled with nitrogen for 30 minutes while stirring until the oxygen content was less than 0.25 mg / l.

[0131] Component B was then sucked into the tank. The material inlet was then closed, and the internal pressure of the tank was adjusted to 25 hPa using a vacuum pump. The reaction continued under this reduced pressure for 19 hours. After the reaction was completed, the reaction mixture was adjusted to a volume of 10 L by adding pure water, and then treated by ultrafiltration (Pall Microza SLP 1053 with a cutoff of 10,000 g / mol), thereby removing 8 L of water. This procedure was repeated six times to remove inorganic salts.

[0132] The resulting dispersion was characterized as having a conductivity of 0.09 S / cm and a solids content of 1.05 wt %.

[0133] Synthesis Example 3 (according to the invention) The 3 L stainless steel jacketed tank is equipped with a mechanical stirrer, a ventilation valve in the upper lid, a closable material inlet and a thermometer. Ingredient A Into this tank, 2000 g of pure water, 16.0 g of 10 wt% aqueous iron(III) sulfate solution, 5.7 g of sulfuric acid (95 wt%), and 100 g of EDOT-S sodium salt (0.29 mol) were introduced. The agitator was operated at 50 rpm, the temperature was adjusted to 20 °C, and the internal pressure was reduced to 100 hPa. The pressure in the tank was then increased to atmospheric pressure, and then reduced to 25 hPa to further evacuate oxygen.

[0134] Component B In a separate glass beaker, 78.5 g of sodium peroxodisulfate was dissolved in 200 ml of water and the solution was bubbled with nitrogen for 30 minutes while stirring until the oxygen content was less than 0.25 mg / l.

[0135] Component B was then sucked into the tank. The material inlet was then closed, and the internal pressure of the tank was adjusted to 25 hPa using a vacuum pump. The initial pH of the reaction solution was 1.9, and the reaction continued under this reduced pressure for 19 hours. After the reaction was completed, the reaction mixture was adjusted to a volume of 10 L by adding pure water, and then treated by ultrafiltration (Pall Microza SLP 1053 with a cutoff of 10,000 g / mol), thereby removing 8 L of water. This procedure was repeated six times to remove inorganic salts.

[0136] The composition thus obtained was characterized as having a conductivity of 27 S / cm and a solids content of 1.22 wt%. The composition was further concentrated by ultrafiltration until a solids content of 2.4 wt% was reached.

[0137] Synthesis Example 4 (Preparation of PEDOT / PSS Dispersion; Not According to the Invention) 868 g of purified water and 330 g of an aqueous solution of polystyrene sulfonic acid with an average molecular weight of 70,000 g / mol and a solids content of 3.8 wt% were initially introduced into a 2 L three-neck flask equipped with a stirrer and thermometer. The reaction temperature was maintained at 20-25°C. 5.1 g of 3,4-ethylenedioxythiophene was added with stirring. The solution was stirred for 30 minutes. 0.03 g of iron(III) sulfate and 9.5 g of sodium persulfate were then added, and the solution was stirred for another 24 hours. After the reaction was completed, 100 ml of a strongly acidic cation exchanger and 250 ml of a weakly basic anion exchanger were added to remove inorganic salts, and the solution was stirred for another 2 hours. The ion exchangers were filtered. The poly(3,4-ethylenedioxythiophene) / polystyrene sulfonate dispersion was homogenized 10 times in a high-pressure homogenizer under a pressure of 700 bar. The dispersion was subsequently concentrated to a solids content of 2.5% and then further homogenized five more times under a pressure of 1500 bar.

[0138] Synthesis Example 5 (Preparation of PEDOT-S Compositions According to Prior Art) 0.496 g of EDOT-S (1.5 mmol) was dissolved in 18 ml of purified water under argon. 0.97 g (6.0 mmol) of FeCl3 was then added in one portion. The solution was then stirred at room temperature for 8 hours, heated at 100 °C for 3 hours, cooled, and worked up. For workup, the solution was diluted to approximately 3 wt % with purified water, 9 g of Lewatit® S100 and 9 g of Lewatit® MP62 were added, and the mixture was stirred at room temperature for 4 hours. After filtering the ion exchanger, a dark blue polymer solution with a solids content of 2.71% was obtained.

[0139] Comparative Example 1 (Fabrication of a Capacitor in Accordance with WO 2014 / 048562 A2) 45 g of the PEDOT / PSS dispersion from Synthesis Example 4, 45 g of the PEDOT-S composition from Synthesis Example 5, and 10 g of polyethylene glycol 400 (PEG-400) were mixed, and the pH was adjusted to 3.0 using ammonia (Dispersion A).

[0140] A porous aluminum foil (anode foil) having dimensions of 200 mm × 5 mm and a porous aluminum foil (cathode foil) having dimensions of 210 mm × 3 mm were formed at 36 V and each equipped with a contact wire, then wrapped with two cellulose separator papers and secured with adhesive tape. Twenty of these oxide electrode bodies were fabricated. The separator papers of the oxide electrode bodies were then carbonized in an oven at 300 °C.

[0141] The oxidized electrode body was immersed in Dispersion A for 15 minutes. Drying was then carried out at 120° C. for 20 minutes and then at 150° C. for 20 minutes. Impregnation and drying were carried out for an additional time. The average electrical value was determined.

[0142] Example 1 (Fabrication of a capacitor according to WO 2014 / 048562 A2) 45 g of the PEDOT / PSS dispersion from Synthesis Example 4, 45 g of the PEDOT-S composition from Synthesis Example 3, and 10 g of polyethylene glycol 400 (PEG-400) were mixed, and the pH was adjusted to 3.0 using ammonia (Dispersion B).

[0143] Capacitors were fabricated according to the procedure in Comparative Example 1. The average electrical values ​​were determined and normalized to Comparative Example 1 and are shown in Table 1.

[0144] [Table 1]

[0145] Synthesis Example 6 (Preparation of PEDOT / PSS Dispersion for Polymer Outer Layer) 1736 g of pure water and 660 g of an aqueous solution of polystyrene sulfonic acid with an average molecular weight of 70,000 g / mol and a solids content of 3.8 wt% were initially introduced into a 5 L glass reactor equipped with a stirrer and thermometer. The reaction temperature was maintained at 20-25°C. 10.2 g of 3,4-ethylenedioxythiophene was added with stirring. The solution was stirred for 30 minutes. 0.06 g of iron(III) sulfate and 19 g of sodium persulfate were then added, and the solution was stirred for another 24 hours. After the reaction was complete, 200 ml of a strongly acidic cation exchanger and 500 ml of a weakly basic anion exchanger were added to remove inorganic salts, and the solution was stirred for another 2 hours. The ion exchangers were filtered. The resulting dispersion reached a solids content of 1.5% by subsequent concentration.

[0146] 160 g of this dispersion, 28 g of water, 6 g of sulfo-polyester (Eastek 1100, 30% solids content, average molecular weight 10,000–15,000, Eastman), 8 g of dimethyl sulfoxide, 1 g of 3-glycidoxypropyltrimethoxysilane (Silquest A-187, OSi Specialties), and 0.4 g of wetting agent (Dynol 604, Air Products) were vigorously mixed for 1 h in a glass beaker equipped with a stirrer.

[0147] Synthesis Example 7 (Preparation of Crosslinker Solution) 4.0 g of p-toluenesulfonic acid monohydrate, 1.7 g of 1,10-diaminodecane, and 95.5 g of water were vigorously mixed in a glass beaker equipped with a stirrer.

[0148] Synthesis Example 8 (Production of an electrode body for a tantalum electrolytic capacitor) Tantalum powder with a specific capacitance of 18,000 CV / g was pressed into pellets with tantalum wire encapsulated and sintered to form porous anode bodies with dimensions of 1.5 mm x 2.9 mm x 4.0 mm. Five of these porous anode bodies were anodized in phosphoric acid electrolyte at 100 V to form a dielectric to obtain capacitor bodies.

[0149] Synthesis Example 9 The composition from Synthesis Example 5 was diluted to a concentration of 2.0% by the addition of purified water.

[0150] Synthesis Example 10 The composition from Synthesis Example 3 was diluted to a concentration of 2.0% by the addition of purified water.

[0151] Comparative Example 2 The capacitor body from Synthesis Example 8 was immersed for 1 minute in the composition from Synthesis Example 9. Drying was then carried out for 10 minutes at 120° C. Impregnation and drying was carried out 9 more times.

[0152] The capacitor body was then immersed in the solution from Synthesis Example 7. Drying was then carried out for 10 minutes at 120° C. The capacitor body was then immersed in the dispersion from Synthesis Example 6. Drying was then carried out for 10 minutes at 120° C.

[0153] The capacitor body was then immersed in the solution from Synthesis Example 7. Drying was then carried out for 10 minutes at 120° C. The capacitor body was then immersed in the dispersion from Synthesis Example 6. Drying was then carried out for 10 minutes at 120° C.

[0154] The capacitor body was then immersed in the solution from Synthesis Example 7. Drying was then carried out for 10 minutes at 120° C. The capacitor body was then immersed in the dispersion from Synthesis Example 6. Drying was then carried out for 10 minutes at 120° C.

[0155] The capacitor body was then coated with a graphite layer and then with a silver layer, thus obtaining the completed capacitor.

[0156] The mean values ​​for the electrical parameters (CAP, ESR) were determined.

[0157] Example 2 Processing of the capacitor body was carried out as described in Comparative Example 2, except that the composition from Synthesis Example 10 was used in place of the composition from Synthesis Example 9.

[0158] The average values ​​for the electrical parameters (CAP, ESR) were determined and normalized to Comparative Example 2. The results are shown in Table 2.

[0159] [Table 2]

[0160] Synthesis Example 11 (not according to the invention) 0.496 g of EDOT-S (1.5 mmol) was dissolved in 18 ml of purified water under argon. 0.97 g (6.0 mmol) of FeCl3 was then added in one portion. The solution was then stirred at room temperature for 8 hours, heated at 100 °C for 3 hours, cooled, and worked up. For workup, the solution was diluted to 1 wt% with purified water, 9 g of Lewatit® S100 and 9 g of Lewatit® MP62 were added, and the mixture was stirred at room temperature for 4 hours. After filtering the ion exchanger, a dark blue polymer solution with a solids content of 1 wt% was obtained. In the resulting composition, the solids content was adjusted to 2.15 wt% by evaporation.

[0161] Synthesis Example 12 (according to the invention) The 3 L stainless steel jacketed tank is equipped with a mechanical stirrer, a ventilation valve in the upper lid, a closable material inlet and a thermometer.

[0162] Ingredient A Into this tank, 2000 g of pure water, 8.0 g of 10 wt% aqueous iron(III) sulfate solution, 2.9 g of sulfuric acid (95 wt%), and 50 g of EDOT-S sodium salt (0.15 mol) were introduced. The agitator was operated at 50 rpm, the temperature was adjusted to 20 °C, and the internal pressure was reduced to 100 hPa. The pressure in the tank was then increased to atmospheric pressure, and then reduced to 25 hPa to further evacuate oxygen.

[0163] Component B In a separate glass beaker, 39.3 g of sodium peroxodisulfate was dissolved in 200 ml of water and the solution was bubbled with nitrogen for 30 minutes while stirring until the oxygen content was less than 0.25 mg / l.

[0164] Component B was then sucked into the tank. The material inlet was then closed, and the internal pressure of the tank was adjusted to 25 hPa using a vacuum pump. The initial pH of the reaction solution was 1.9, and the reaction continued under this reduced pressure for 19 hours. After the reaction was complete, 600 g of Lewatit Monoplus S 108H and 500 g of Lewatit MP62 (Lanxess AG, Cologne) were added and stirred with a mechanical stirrer. After 6 hours, the Lewatit was removed by filtration.

[0165] The sample was concentrated by rotary evaporation until the solids content reached more than 2 wt %. The resulting composition was characterized as having a solids content of 2.14 wt %.

[0166] Synthesis Example 13 (according to the invention) The 3 L stainless steel jacketed tank is equipped with a mechanical stirrer, a ventilation valve in the upper lid, a closable material inlet and a thermometer.

[0167] Ingredient A Into this tank, 2000 g of pure water, 16.0 g of 10 wt% aqueous iron(III) sulfate solution, 5.7 g of sulfuric acid (95 wt%), and 100 g of EDOT-S sodium salt (0.29 mol) were introduced. The agitator was operated at 50 rpm, the temperature was adjusted to 20 °C, and the internal pressure was reduced to 100 hPa. The pressure in the tank was then increased to atmospheric pressure, and then reduced to 25 hPa to further evacuate oxygen.

[0168] Component B In a separate glass beaker, 78.5 g of sodium peroxodisulfate was dissolved in 200 ml of water and the solution was bubbled with nitrogen for 30 minutes while stirring until the oxygen content was less than 0.25 mg / l.

[0169] Component B was then sucked into the tank. The material inlet was then closed, and the internal pressure of the tank was adjusted to 25 hPa using a vacuum pump. The initial pH of the reaction solution was 1.9, and the reaction continued under this reduced pressure for 19 hours. After the reaction was complete, 1100 g of Lewatit Monoplus S 108H and 1000 g of Lewatit MP62 (Lanxess AG, Cologne) were added and stirred with a mechanical stirrer. After 6 hours, the Lewatit was removed by filtration.

[0170] The resulting composition was characterized as having a solids content of 1.19 wt%. The composition was further concentrated by rotary evaporation until the solids content reached more than 2 wt%. The resulting composition was characterized as having a solids content of 2.15% and a conductivity of 41 S / cm.

[0171] The mass average molecular weights M of the compositions obtained in Synthesis Examples 11, 12, and 13 were w and the molar average molecular weight M n are shown in Table 3 below:

[0172] [Table 3]

[0173] Comparative Example 3 An aluminum capacitor was fabricated as in Comparative Example 1 with the only difference being that the composition from Synthesis Example 11 was used instead of the composition from Synthesis Example 5.

[0174] Example 3 Aluminum capacitors were fabricated as in Example 1 with the only difference being that the composition from Synthesis Example 12 was used instead of the composition from Synthesis Example 3.

[0175] Example 4 Aluminum capacitors were fabricated as in Example 1 with the only difference being that the composition from Synthesis Example 13 was used instead of the composition from Synthesis Example 3.

[0176] The average values ​​for the electrical parameters (CAP, ESR) are shown in Table 4, where the values ​​are normalized to Comparative Example 3. Also shown are the ESR values ​​of the capacitors after 500 hours of storage at 85°C and 85% relative humidity (values ​​are normalized to the corresponding values ​​before storage under these conditions).

[0177] [Table 4]

[0178] These results suggest that a high M (>6) is required for the fabrication of a solid electrolyte layer in the capacitor. w / M n It clearly shows that when a PEDOT-S composition having a M value of 1.0 or more is used, not only can the ESR value be improved (as can be seen in the third column of Table 4), but also the stability can be improved when the capacitor is stored at high temperature and high relative humidity. As can be seen in the fourth column of Table 4, compared to the capacitor with a solid electrolyte layer prepared with a PEDOT-S composition according to the prior art, the ESR value increases to a lesser extent in the capacitor, whose solid electrolyte layer is prepared with a PEDOT-S composition according to the present invention (i.e., a M value of more than 6). w / M n The PEDOT-S composition (having a value of 0.01) was used.

[0179] Synthesis Example 14 (Preparation of Electrode Body for Tantalum Electrolytic Capacitor) Tantalum powder with a specific capacitance of 30,000 CV / g was pressed into pellets encapsulating tantalum wire and sintered to form porous anode bodies with dimensions of 1.4 mm x 2.8 mm x 3.9 mm. Five of these porous anode bodies were anodized in phosphoric acid electrolyte at 60 V to form the dielectric to obtain the capacitor body.

[0180] Comparative Example 4 A tantalum electrolytic capacitor was fabricated as in Comparative Example 2, except that the capacitor body from Synthesis Example 14 was used instead of the capacitor body from Synthesis Example 8, and the composition from Synthesis Example 11 was used instead of the composition from Synthesis Example 9.

[0181] Example 5 A tantalum electrolytic capacitor was prepared as in Example 2, except that the capacitor body from Synthesis Example 14 was used instead of the capacitor body from Synthesis Example 8, and the composition from Synthesis Example 12 was used instead of the composition from Synthesis Example 10.

[0182] Example 6 A tantalum electrolytic capacitor was prepared as in Example 2, except that the capacitor body from Synthesis Example 14 was used instead of the capacitor body from Synthesis Example 8, and the composition from Synthesis Example 13 was used instead of the composition from Synthesis Example 10.

[0183] The average values ​​for the electrical parameters (CAP, ESR) are shown in Table 5, and the values ​​were normalized to Comparative Example 4.

[0184] [Table 5]

[0185] These results clearly indicate that both the capacitance and ESR value can be improved when PEDOT-S compositions with high Mw / Mn values ​​greater than 6 are used for the preparation of solid electrolytes in capacitors.

[0186] Synthesis Example 15 (not according to the invention) The 3 L stainless steel jacketed tank is equipped with a mechanical stirrer, a ventilation valve in the upper lid, a closable material inlet and a thermometer.

[0187] Ingredient A Into this tank, 2000 g of pure water, 16.0 g of 10 wt% aqueous iron(III) sulfate solution, 5.7 g of sulfuric acid (95 wt%), and 100 g of EDOT-S sodium salt (0.29 mol) containing 20 wt% PRODOT-S sodium salt (determined by HPLC) were introduced. The agitator was operated at 50 rpm, the temperature was adjusted to 20°C, and the internal pressure was reduced to 100 hPa. The pressure in the tank was then increased to atmospheric pressure and then reduced to 25 hPa to further evacuate oxygen.

[0188] Component B In a separate glass beaker, 78.5 g of sodium peroxodisulfate was dissolved in 200 ml of water and the solution was bubbled with nitrogen for 30 minutes while stirring until the oxygen content was less than 0.25 mg / l.

[0189] Component B was then sucked into the tank. The material inlet was then closed, and the internal pressure of the tank was adjusted to 25 hPa using a vacuum pump. The initial pH of the reaction solution was 1.9, and the reaction continued under this reduced pressure for 19 hours. After the reaction was completed, the reaction mixture was adjusted to a volume of 10 L by adding pure water, and then treated by ultrafiltration (Pall Microza SLP 1053 with a cutoff of 10,000 g / mol), thereby removing 8 L of water. This procedure was repeated six times to remove inorganic salts.

[0190] The resulting dispersion had a solids content of 1.47 wt % and was further concentrated by rotary evaporation to a solids content of 2.96 wt %.

[0191] Synthesis Example 16 (according to the invention) A PEDOT-S composition was prepared in the same manner as in Synthesis Example 15, with the only difference being that EDOT-S sodium salt containing 10 wt % PEDOT-S sodium salt was used.

[0192] Comparative Example 5 A tantalum electrolytic capacitor was prepared as in Comparative Example 4 with the only difference being that the composition from Synthesis Example 15 was used instead of the composition from Synthesis Example 11.

[0193] Example 7 A tantalum electrolytic capacitor was prepared as in Example 5 with the only difference being that the composition from Synthesis Example 16 was used instead of the composition from Synthesis Example 10.

[0194] The average values ​​for the electrical parameters (CAP, ESR) are shown in Table 6, and the values ​​were normalized to Comparative Example 5.

[0195] [Table 6]

[0196] These results clearly show that when a PEDOT-S composition having only 10 wt% PRODOT-S content was used for the preparation of a solid electrolyte layer in a tantalum electrolytic capacitor, the ESR value was significantly lower compared to that of a tantalum electrolytic capacitor whose solid electrolyte was prepared using a PEDOT-S composition based on the EDOT-S monomer having a PRODOT-S content of 20 wt%.

Claims

1. A liquid composition comprising a functionalized π-conjugated polythiophene, said polythiophene having a repeating unit of general formula (I): 【Chemistry 1】 (wherein X and Y are the same or different and are O, S, or NR １ where R １ is hydrogen or an aliphatic or aromatic residue having 1 to 18 carbon atoms, and A is an organic residue bearing an anionic functional group. wherein the functionalized π-conjugated polythiophene has a weight average molecular weight M ｗ relative to the molar average molecular weight M ｎ The ratio (M ｗ / M ｎ ) is at least 8.

2. X and Y are O; A is -(CH ２ ) ｍ -CR ２ R ３ - (CH ２ ) ｎ -, where: R ２ is hydrogen or -(CH ２ ) ｓ -Z-(CH ２ ) ｐ -SO ３ － M+, R ３ is -(CH ２ ) ｓ -Z-(CH ２ ) ｐ -SO ３ － M+, Z is O, S or —CH ２ - and M+ is a cation, m and n are the same or different and are integers from 0 to 3; s is an integer from 0 to 10; p is an integer from 1 to 18; The liquid composition of claim 1 .

3. In the general formula (I), X and Y are O; A is -(CH ２ )-CR ２ R ３ - (CH ２ ) ｎ -, where: R ２ is hydrogen, R ３ is -(CH ２ ) ｓ -O-(CH ２ ) ｐ -SO ３ － M+, M+ is Na ＋ or K ＋ and n is 0 or 1; s is 0 or 1; p is 4 or 5; The liquid composition according to claim 1 or 2.

4. X and Y are O; A is -(CH ２ —CHR)—, where R is -(CH ２ ) ｔ -O-Ar-[(W) ｕ -SO ３ － M+] ｖ where: Ar is an optionally substituted C ６ -C ２０ represents an arylene group, W is an optionally substituted C １ -C ６ represents an alkylene group, M+ is H ＋ , Li ＋ , Na ＋ , and K ＋ an alkali cation selected from the group consisting of NH(R １ ) ３ ＋ or HNC ５ H ５ ＋ where each R １ The groups are independently hydrogen atoms or optionally substituted C １ -C ６ represents an alkyl group, t represents an integer of 0 to 6; u represents an integer of 0 or 1; v represents an integer of 1 to 4; The liquid composition of claim 1 .

5. The weight average molecular weight M of the functionalized π-conjugated polythiophene ｗ The liquid composition according to any one of claims 1 to 4, wherein the σ is at least 50000 g / mol.

6. The weight average molecular weight M of the functionalized π-conjugated polythiophene ｗ The liquid composition according to claim 5, wherein the σ is in the range of 125,000 g / mol to 240,000 g / mol.

7. The molar average molecular weight M of the functionalized π-conjugated polythiophene ｎ The liquid composition according to any one of claims 1 to 6, wherein the σ is less than 25000 g / mol.

8. In the liquid composition, the functionalized π-conjugated polythiophene is present in the form of particles, the particles comprising: i) d in the range of 1 to 100 nm ５０ value (weight average particle size), and ii) 3.5 x d ５０ Less than d ９０ value The liquid composition according to any one of claims 1 to 7, characterized by:

9. The liquid composition according to any one of claims 1 to 8, wherein a conductive layer produced by said liquid composition has a conductivity of more than 12 S / cm.

10. The liquid composition according to any one of claims 1 to 9, wherein the functionalized π-conjugated polythiophene comprises a repeating unit of the general formula (I).

11. Use of the liquid composition according to any one of claims 1 to 10 for making a conductive layer in an electronic device.

12. 12. The use according to claim 11, wherein the device is selected from photoconductive cells, photoresistors, photoswitches, phototransistors, phototubes, IR detectors, photovoltaic devices, solar cells, coating materials for memory storage devices, field effect resistive devices, antistatic films, biosensors, electrochromic elements, solid electrolytic capacitors, energy storage devices, touch panels and electromagnetic wave shields.

13. The use according to claim 11, wherein the conductive layer is a solid electrolyte layer in a solid electrolytic capacitor.

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