Poly(3,4-ethylene-dioxythiophene (PEDOT)-dispersion with high number of particles

Abstract

The present invention relates to a dispersion comprising: i) a dispersant; ii) at least one polythiophene dispersed in the dispersant i); wherein the dispersion comprises particles having a particle size of 1.5 μm or larger, the total number of such particles being in the range of 20,000 to 1,000,000 per ml; and wherein a conductive layer prepared from the dispersion has a surface roughness Rq in the range of 4 nm to 23 nm. The present invention also relates to a process for preparing a dispersion, a dispersion that can be obtained by the process, a process for preparing a layer, a layer that can be obtained by the process, and the use of a dispersion for forming a polymeric outer layer in a capacitor.

Description

PEDOT dispersion with a high particle number The present invention relates to a dispersion comprising a dispersant and at least one polythiophene dispersed in the dispersant, a process for preparing a dispersion, a dispersion obtainable by the process, a process for preparing a laminate, a laminate obtainable by the process, and the use of a dispersion for forming a polymeric outer layer in a capacitor. Standard electrolytic capacitors generally consist of: a porous metal electrode, an oxide layer provided on the metal surface, a conductive material (usually solid) introduced into the porous structure, an external electrode (contact member) (such as a silver layer), and other electrical contact members, and a package. A commonly used electrolytic capacitor is a tantalum electrolytic capacitor, whose anode electrode is made of valve metal tantalum, and a uniform tantalum pentoxide dielectric layer has been generated thereon through anodic oxidation (also known as "formation"). A liquid or solid electrolyte forms the cathode of the capacitor. Aluminum capacitors are also often used, whose anode electrode is made of valve metal aluminum, and a uniform electrically insulating aluminum oxide layer is generated thereon by anodic oxidation as the dielectric. Here, a liquid electrolyte or a solid electrolyte also forms the cathode of the capacitor. Aluminum capacitors are usually embodied as wound capacitors or stacked capacitors. π-conjugated polymers are particularly suitable as solid electrolytes in the above capacitors due to their high conductivity. π-conjugated polymers are also known as conductive polymers or synthetic metals. They are gradually gaining increasing commercial importance because, compared with metals, polymers have the advantages of being in terms of process, weight, and selective property adjustment through chemical modification. Examples of known π-conjugated polymers include polypyrrole, polythiophene, polyaniline, polyacetylene, polyphenylene, and poly(p-phenylene-vinylene), among which poly(3,4-ethylenedioxythiophene) (PEDOT) is a particularly important polythiophene in technical use because its oxidized form has extremely high conductivity. In addition to a low equivalent series resistance (ESR), modern electrolytic capacitors require low leakage current and good stability with respect to external stress. High mechanical stress that can significantly increase the leakage current of the capacitor anode particularly occurs during the production process when encapsulating the capacitor anode. The stability against such stress and thus the low leakage current can mainly be achieved by an outer layer made of a conductive polymer with a thickness of approximately 5 µm to 50 µm on the capacitor anode. This layer is used as a mechanical buffer between the capacitor anode and the cathode-side electrode. This prevents the silver layer (contact) from directly contacting the dielectric or being damaged when subjected to mechanical stress, and thus increases the leakage current of the capacitor. In the prior art, PEDOT / PSS dispersions are used not only for forming a solid electrolyte layer but also for forming a polymeric outer layer to be applied on top of the solid electrolyte layer. DE-A-10 2005 033 839, for example, discloses the use of a dispersion comprising particles of a conductive polymer and a binder for forming a polymeric outer layer, wherein the proportion of the particles of the conductive polymer having a diameter of less than 700 nm in the dispersion forms a solid content of at least 5% based on the solid content of the dispersion, and wherein the dispersion additionally comprises solid particles having a size in the range from 0.7 µm to 20 µm. However, it has been observed that for certain applications, the leakage current of solid electrolyte capacitors whose polymeric outer layer has been prepared using a PEDOT / PSS-based dispersion (such as those disclosed in DE-A-10 2005 033 839) is generally too high. The object of the present invention is to overcome the disadvantages associated with capacitors in the prior art, preferably associated with solid electrolytic capacitors, more preferably associated with capacitors known from the prior art comprising a polymeric outer layer on top of a solid electrolyte layer, wherein the polymeric outer layer is based on a π-conjugated polymer (such as PEDOT), even more preferably associated with capacitors known from the prior art comprising a PEDOT / PSS-based polymeric outer layer. Specifically, the present invention is based on the object of providing a dispersion comprising at least one polythiophene, preferably a dispersion comprising a complex of a polythiophene and a polyvalent anion, more preferably a dispersion comprising a PEDOT / PSS complex, which is particularly useful for preparing a polymeric outer layer in capacitors characterized by low leakage current. The object of the present invention also lies in providing a process by means of which such advantageous dispersions can be prepared. The process for preparing advantageous capacitors should also be characterized in that it allows the production of such capacitors in the simplest possible way, in particular with the least possible number of process steps. Furthermore, the object of the present invention is to provide a process for preparing a laminate, preferably for preparing an electrolyte capacitor, wherein the electrolyte capacitor is characterized by a reduced leakage current compared to electrolyte capacitors known from the prior art. The contribution to at least partially solving at least one of the above objects (preferably more than one) is made by the independent claims. The dependent claims provide preferred embodiments contributing to at least partially solving at least one of these objects. |1a| The contribution to solving at least one of the objects according to the present invention is made by a first embodiment of a dispersion comprising the following i) a dispersant (also referred to as "dispersing agent"); dispersing agent); ii) Dispersed in the dispersant i) at least one polythiophene; wherein the dispersion contains particles having a particle size of 1.5 µm or greater, and the total number of these particles is in the range of 20,000 (i.e., 2 × 10 4 ) to 1,000,000 per ml, preferably in the range of 50,000 to 900,000 per ml, more preferably in the range of 75,000 to 900,000 per ml, and even more preferably in the range of 100,000 to 900,000 per ml; and wherein a conductive layer prepared from the dispersion has a surface roughness Rq in the range of 4 nm to 23 nm, preferably in the range of 4 nm to 20 nm, more preferably in the range of 4 nm to 15 nm, and most preferably in the range of 4 nm to 10 nm. As used in the context of the present invention, the term "dispersion ( dispersion)" generally refers to a liquid composition in which polythiophene (e.g., polythiophene that is part of a complex containing polythiophene and a polyvalent anion) is distributed in a homogeneous phase formed by a liquid dispersant i) (the dispersant i) thus forming the liquid phase of the dispersion). It should be noted that the transition between "dispersion ( dispersion)" and "solution" can be fluid. Therefore, hereinafter, there is no distinction between the terms "dispersed ( dispersed)" and "dissolved ( dissolved)". Similarly, there is no distinction between "dispersion" and "solution" or between "dispersant ( dispersant)" and "solvent ( solvent)". More precisely, these terms are used synonymously hereinafter. |2a| According to a preferred embodiment of the dispersion according to the present invention, the dispersion contains more than 1,500 particles per ml, and these particles have a particle size of 10 µm or greater, preferably more than 2,000 particles per ml, more preferably more than 3,000 particles per ml, and even more preferably more than 5,000 particles per ml. This preferred embodiment is the second embodiment of the dispersion according to the present invention, and it is preferably subordinate to the first embodiment. |3a| According to a further preferred embodiment of the dispersion according to the present invention, the polythiophene ii) It exists in the form of particles containing a complex of the polythiophene and a polyvalent anion, and the number and size of the particles as defined in the first and second embodiments of the dispersion according to the present invention refer to the number and size of such particles containing a complex of the polythiophene and a polyvalent anion. This preferred embodiment is according to the third embodiment of the dispersion according to the present invention, and it preferably belongs to the first or second embodiment. |4a| According to a preferred embodiment of the dispersion according to the present invention, the dispersant i) contains water. Preferably, in each case based on the total weight of the dispersion, the dispersant i) contains at least 50 wt.-%, more preferably at least 65 wt.-%, even more preferably at least 70 wt.-%, and most preferably at least 80 wt.-% of water. This preferred embodiment is according to the fourth embodiment of the dispersion according to the present invention, and it preferably belongs to any one of the first to third embodiments. |5a| According to a further preferred embodiment of the dispersion according to the present invention, the at least one polythiophene ii) is: an externally doped polythiophene, such as a cationic polythiophene in the form of a polythiophene / polyvalent anion complex, more preferably in the form of a PEDOT / PSS complex; a self-doped polythiophene, such as poly(4-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]propane-1-sulfonic acid), poly(4-[(2,3-dihydro-thieno-[3,4-b]-[1,4]dioxin-2-yl)methoxy]butane-1-sulfonic acid) (PEDOT-S), or poly(4-[(2,3-dihydrothieno[3,4-b][1,4]dioxin-2-yl)methoxy]butane-2-sulfonic acid), or a mixture thereof. This preferred embodiment is according to the fifth embodiment of the dispersion according to the present invention, and it preferably belongs to any one of the first to fourth embodiments. |6a| According to a further preferred embodiment of the dispersion according to the present invention, the at least one polythiophene ii) exists in the form of particles containing a complex of the at least one polythiophene ii) and a polyvalent anion. This preferred embodiment is according to the sixth embodiment of the dispersion according to the present invention, and it preferably belongs to any one of the first to fifth embodiments. |7a| According to a further preferred embodiment of the dispersion according to the present invention, the at least one polythiophene ii) exists in the form of particles containing the at least one polythiophene ii) and in the form of particles of a complex of a polyvalent anion, wherein the polythiophene is poly(3,4-ethylenedioxythiophene), and the polyvalent anion is the anion of polystyrene sulfonic acid. Thus, the complex of polythiophene and polyvalent anion is preferably a PEDOT / PSS complex. This preferred embodiment is the 7th embodiment of the dispersion according to the present invention, which preferably belongs to any one of the 1st to 6th embodiments. |8a| According to a further preferred embodiment of the dispersion according to the present invention, the at least one polythiophene ii) is present in the form of particles of a complex comprising the at least one polythiophene ii) and a polyvalent anion, preferably in the form of particles comprising PEDOT / PSS, wherein the dispersion comprises a polyvalent anion and a polythiophene in a weight ratio of polyvalent anion to polythiophene in the following ranges: in the range of 0.5:1 to 30:1, preferably in the range of 0.8:1 to 15:1, more preferably in the range of 1:1 to 10:1, even more preferably in the range of 1.2:1 to 8:1, and most preferably in the range of 1.4:1 to 4:1. Assuming complete conversion during the polymerization reaction, the weight of the polythiophene in this case corresponds to the weighed amount of the thiophene monomer used to prepare the polythiophene. This preferred embodiment is the 8th embodiment of the dispersion according to the present invention, which preferably belongs to any one of the 1st to 7th embodiments. |9a| According to a further preferred embodiment of the dispersion according to the present invention, the at least one polythiophene ii) is present in the form of particles of a complex comprising the at least one polythiophene ii) and a polyvalent anion, preferably in the form of particles comprising PEDOT / PSS, wherein the weight average diameter ( d 50 ) as determined by ultracentrifugation of such particles is in the range of 10 nm to 500 nm, more preferably in the range of 20 nm to 400 nm, even more preferably in the range of 30 nm to 300 nm, and most preferably in the range of 40 nm to 300 nm. This preferred embodiment is the 9th embodiment of the dispersion according to the present invention, which preferably belongs to any one of the 1st to 8th embodiments. |10a| In a further preferred embodiment of the dispersion according to the present invention, the at least one polythiophene ii) is present in the form of particles comprising a complex of the at least one polythiophene ii) and a polyvalent anion, preferably in the form of particles comprising PEDOT / PSS, wherein the dispersion has a diameter distribution of such particles of less than 1,000 nm, preferably less than 800 nm, more preferably less than 600 nm, and most preferably less than 500 nm as determined by ultracentrifugation measurement. d 90 value. This preferred embodiment is the 10th embodiment of the dispersion according to the present invention, which preferably belongs to any one of the 1st to 9th embodiments. |11a| In a further preferred embodiment of the dispersion according to the present invention, the at least one polythiophene ii) is present in the form of particles comprising a complex of the at least one polythiophene ii) and a polyvalent anion, preferably in the form of particles comprising PEDOT / PSS, wherein the dispersion has a diameter distribution of such particles of greater than 2 nm, preferably greater than 5 nm, more preferably greater than 10 nm, and most preferably greater than 20 nm as determined by ultracentrifugation measurement. d 10 value. This preferred embodiment is the 11th embodiment of the dispersion according to the present invention, which preferably belongs to any one of the 1st to 10th embodiments. |12a| In a further preferred embodiment of the dispersion according to the present invention, in each case based on the total weight of the dispersion, the dispersion has a solids content of at least 1 wt.-%, preferably at least 1.4 wt.-%, more preferably at least 1.6 wt.-%, even more preferably at least 1.8 wt.-%, and most preferably at least 2.0 wt.-%. This preferred embodiment is the 12th embodiment of the dispersion according to the present invention, which preferably belongs to any one of the 1st to 11th embodiments. |13a| In a further preferred embodiment of the dispersion according to the present invention, the dispersion has a pH value (determined at 25 °C) in the range of 1 to 8.0, preferably in the range of 1.5 to 7, and more preferably in the range of 2.5 to 6. This preferred embodiment is the 13th embodiment of the dispersion according to the present invention, which preferably belongs to any one of the 1st to 12th embodiments. |14a| According to a further preferred embodiment of the dispersion according to the present invention, a conductive layer prepared from the dispersion has a conductivity of at least 10 S / cm, preferably at least 50 S / cm, more preferably at least 100 S / cm, and most preferably at least 200 S / cm as determined by the test method disclosed herein (i.e., a test method for determining the conductivity of the conductive layer by targeting the dispersion obtained after 1 g of DMSO has been added to 19 g of the dispersion according to the present invention). This preferred embodiment is the 14th embodiment of the dispersion according to the present invention, which preferably belongs to any one of the 1st to 13th embodiments. |15a| According to a further preferred embodiment of the dispersion according to the present invention, the at least one polythiophene ii) is present in the form of particles comprising a complex of the at least one polythiophene ii) and a polyvalent anion, preferably in the form of particles comprising PEDOT / PSS, wherein in each case based on the total weight of the dispersion, the dispersion comprises at least 1 wt.-%, preferably at least 1.4 wt.-%, more preferably at least 1.6 wt.-%, even more preferably 1.7 wt.-%, and most preferably at least 1.8 wt.-% in total of the polythiophene and the polyvalent anion (i.e., the amount of polythiophene plus the amount of polyvalent anion). This preferred embodiment is the 15th embodiment of the dispersion according to the present invention, which preferably belongs to any one of the 1st to 14th embodiments. |16a| According to a further preferred embodiment of the dispersion according to the present invention, the dispersion further comprises: iii) at least one additive, wherein the at least one additive is an additive selected from the group consisting of: binders, pH regulators, crosslinking agents, tackifiers, conductivity improvers, surfactants, stabilizers, and combinations of at least two of these additives. This preferred embodiment is the 16th embodiment of the dispersion according to the present invention, which preferably belongs to any one of the 1st to 15th embodiments. |17a| According to a further preferred embodiment of the dispersion according to the present invention, the dispersion further comprises as an additive: iii) At least one organic binder, preferably at least one organic binder selected from the group consisting of: polyolefins, polyvinyl acetate, polycarbonates, polyvinyl butyral, polyacrylates, polyacrylamides, polymethacrylates, polymethacrylamides, polystyrenes, polyacrylonitriles, polyvinyl chlorides, polyvinyl pyrrolidone, polybutadienes, polyisoprenes, polyethers, polyesters, polyurethanes, polyamides, polyimides, polysulfones, polysilicon, epoxy resins, styrene-acrylates, vinyl acetate / acrylates and ethylene / vinyl acetate copolymers, polyvinyl alcohols, or cellulose derivatives, and mixtures thereof. Preferably, in each case based on the total weight of the dispersion, the amount of the dispersion is in the range of 0.1 wt.-% to 20 wt.-%, preferably in the range of 0.5 wt.-% to 15 wt.-%, more preferably in the range of 1 wt.-% to 10 wt.-%, and even more preferably in the range of 1 wt.-% to 5 wt.-%. This preferred embodiment is the 17th embodiment of the dispersion according to the present invention, which is preferably subordinate to the 16th embodiment. |18a |According to a further preferred embodiment of the dispersion according to the present invention, the dispersion has a viscosity in the range of 1 to 1000 mPa×s, preferably in the range of 5 to 750 mPa×s, more preferably in the range of 10 to 500 mPa×s, and most preferably in the range of 20 to 300 mPa×s (measured using a rheometer at a shear rate of 20°C and 100 s -1 ). This preferred embodiment is the 18th embodiment of the dispersion according to the present invention, which is preferably subordinate to any one of the 1st to 17th embodiments. |1b| A contribution to solving at least one of the objects according to the present invention is also made by the 1st embodiment of process 1 for preparing the dispersion, which comprises the following steps: I) Providing a dispersion comprising i) a dispersant; ii) at least one polythiophene dispersed in the dispersant i) by polymerizing thiophene monomers in the presence of the dispersant i); II) In the process step Adjust the size of the particles having a particle diameter of 1.5 µm or greater in the dispersion provided in I) to within the range of 20,000 to 1,000,000 per ml, preferably within the range of 50,000 to 900,000 per ml, more preferably within the range of 75,000 to 900,000 per ml, and even more preferably within the range of 100,000 to 900,000 per ml. |2b|According to a preferred embodiment of Process 1 according to the present invention, the dispersant i) contains water. Preferably, in each case based on the total weight of the dispersion, the dispersant i) contains at least 50 wt.-%, more preferably at least 65 wt.-%, even more preferably at least 70 wt.-%, and most preferably at least 80 wt.-% of water. This preferred embodiment is the second embodiment of Process 1 according to the present invention, which is preferably subordinate to the first embodiment. |3b|According to a further preferred embodiment of Process 1 according to the present invention, polymerize the thiophene monomer in the presence of the dispersant i) and in the presence of a polyvalent anion to obtain a dispersion containing a complex of polythiophene and a polyvalent anion. This preferred embodiment is the third embodiment of Process 1 according to the present invention, which is preferably subordinate to the first or second embodiment. |4b|According to a further preferred embodiment of Process 1 according to the present invention, polymerize the thiophene monomer in the presence of the dispersant i) and in the presence of a polyvalent anion to obtain a dispersion containing a complex of polythiophene and a polyvalent anion, wherein the polythiophene is 3,4-ethylenedioxythiophene and the polyvalent anion is the anion of polystyrene sulfonic acid. Therefore, the complex of polythiophene and a polyvalent anion is preferably a PEDOT / PSS complex. This preferred embodiment is the fourth embodiment of Process 1 according to the present invention, which is preferably subordinate to any one of the first to third embodiments. |5b|According to a further preferred embodiment of Process 1 according to the present invention, the adjustment of the number of particles having a particle diameter of 1.5 µm or greater in the dispersion provided in process step I) is accomplished by a process comprising the following process steps: IIa) subject the dispersion obtained in process step I) to a first filtration step, wherein the dispersion is filtered through a filter having a cut off size in the range of 100 µm to 150 µm, preferably in the range of 120 µm to 130 µm; IIb) subject the dispersion obtained in process step The dispersion obtained in IIa) is subjected to a further filtration step, in which the dispersion is filtered through a filter having a cut-off size in the range of 1 µm to 50 µm, preferably in the range of 5 µm to 15 µm, wherein this filtration is preferably carried out at a pressure not greater than 1 bar, preferably not greater than 0.8 bar, more preferably not greater than 0.6 bar, even more preferably not greater than 0.4 bar, and most preferably not greater than 0.2 bar. This preferred embodiment is the 5th embodiment of Process 1 according to the present invention, which is preferably subordinate to any one of the 1st to 4th embodiments. |6b| According to a further preferred embodiment of Process 1 according to the present invention, the adjustment of the number of particles having a particle size of 1.5 µm or greater in the dispersion provided in Process Step I) is accomplished by a process comprising the following process steps: IIa) A portion of the dispersion obtained in Process Step I), preferably 80 wt.-% to 94 wt.-%, more preferably 88 wt.-% to 92 wt.-% is separated from the dispersion and this separated portion is subjected to a high-pressure homogenization step carried out at a pressure of at most 2000 bar, preferably at most 1,500 bar, at least 8 times, preferably at least 10 times, followed by a filtration step, in which the dispersion is filtered through a filter having a cut-off size in the range of 3 µm to 8 µm, preferably 4 µm to 5 µm; IIb) The remaining portion of the dispersion provided in Process Step I) is subjected to removal of the ion exchange resin by means of a 400 µm filter. IIc) The thus obtained filtered portions of the dispersion are recombined. This preferred embodiment is the 6th embodiment of Process 1 according to the present invention, which is preferably subordinate to any one of the 1st to 4th embodiments. |1c| A contribution to solving at least one of the objects according to the present invention is also made by a dispersion obtainable by Process 1 according to the present invention, preferably by Process 1 according to any one of its 1st to 6th embodiments. Preferably, this dispersion has the same properties as the dispersion according to the present invention, preferably as defined in any one of its 1st to 18th embodiments. |1d| A contribution to solving at least one of the objects according to the present invention is also made by the 1st embodiment of Process 2 for preparing a laminate, which comprises the following process steps: A) Provide a substrate; B) Apply the dispersion according to the present invention, preferably the dispersion according to the present invention as defined in any one of its 1st to 18th embodiments, or a dispersion obtainable by Process 1 according to the present invention, preferably by Process 1 as defined in any one of its 1st to 6th embodiments, to at least a part of the surface of this substrate; C) Remove at least part of the dispersant i), to obtain a layer body comprising a conductive layer, which conductive layer is coated on at least a part of the surface of the substrate. |2d| According to a preferred embodiment of Process 2 according to the present invention, this layer system is part of an electrolytic capacitor, wherein the substrate is a porous electrode body made of an electrode material, wherein a dielectric layer at least partially covers the surface of this electrode material, wherein a solid electrolyte layer at least partially covers the surface of the dielectric layer, and wherein the conductive layer is a polymeric outer layer that at least partially covers the surface of the solid electrolyte layer. This preferred embodiment is the 2nd embodiment of Process 2 according to the present invention, which is preferably subordinate to the 1st embodiment. |3d| According to a preferred embodiment of Process 2 according to the present invention, the method comprises the following steps: A) Provide a porous electrode body made of an electrode material, wherein a dielectric layer at least partially covers the surface of this electrode material, and wherein a solid electrolyte layer at least partially covers the surface of the dielectric layer; B) Apply the dispersion according to the present invention, preferably the dispersion according to the present invention as defined in any one of its 1st to 18th embodiments, or a dispersion obtainable by Process 1 according to the present invention, preferably by Process 1 as defined in any one of its 1st to 6th embodiments, to at least a part of the surface of the solid electrolyte layer; C) Remove at least part of the dispersant i), for forming a polymeric outer layer that at least partially covers the surface of the solid electrolyte layer; This preferred embodiment is the 3rd embodiment of Process 2 according to the present invention, which is preferably subordinate to the 1st embodiment or the 2nd embodiment. |4d| According to a further preferred embodiment of Process 2 according to the present invention, this layer system is an aluminum capacitor or a tantalum capacitor. This preferred embodiment is the 4th embodiment of Process 2 according to the present invention, which is preferably subordinate to any one of its 1st to 3rd embodiments. |1e| The contribution to solving at least one of the objects according to the present invention is also made by a layer body obtainable by Process 2 according to the present invention, preferably by Process 2 according to any one of its 1st to 4th embodiments. The contribution to solving at least one of the objects according to the present invention is also made by the following uses: the dispersion according to the present invention, preferably the dispersion according to the present invention as defined in any one of its 1st to 18th embodiments, or a dispersion obtainable by process 1 according to the present invention, preferably by process 1 as defined in any one of its 1st to 6th embodiments. |2f|According to a preferred embodiment of the use according to the present invention, the capacitor is an aluminum capacitor or a tantalum capacitor. This preferred embodiment is the 2nd embodiment of the use according to the present invention, which preferably belongs to the 1st embodiment. Polythiophene The dispersion according to the present invention contains a dispersant and at least one polythiophene dispersed in the dispersant. Preferred polythiophenes are those having repeating units of general formula (I), general formula (II), general formula (III), or polythiophenes containing a combination of such repeating units: (I) (II) (III) wherein A is optionally substituted C 1 -C 5 -alkylene radical, R is independently H, linear or branched optionally substituted C 1 -C 18 -alkyl radical, optionally substituted C 5 -C 12 -cycloalkyl radical, optionally substituted C 6 -C 14 -aryl radical, optionally substituted C 7 -C 18 -aralkyl radical, optionally substituted C 1 -C 4 -hydroxyalkyl radical, or hydroxyl radical, x is an integer from 0 to 8, and in the case where a plurality of R radicals are bonded to A, they may be the same or different. General formula (I) and general formula (II) should be understood as x substituents R being bonded to the alkylene radical A. Particularly preferred are polythiophenes having repeating units of general formula (I) or general formula (II) or repeating units of general formula (I) and general formula (II), wherein A is optionally substituted C 2 -C 3 -alkylene radical, and x is 0 or 1. A particularly preferred polythiophene is optionally substituted poly(3,4-ethylenedioxythiophene) (PEDOT), the same as poly(4-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]propane-1-sulfonic acid), poly(4-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]butane-1-sulfonic acid) (PEDOT-S), or poly(4-[(2,3-dihydrothieno[3,4-b][1,4]dioxin-2-yl)methoxy]butane-2-sulfonic acid). In the context of the present invention, the prefix "poly( poly-)" should be understood to mean that there are more than one identical or different repeating units present in the polymer or polythiophene. The polythiophene contains a total of n repeating units of general formula (I) or general formula (II) or general formula (III), or general formula (I) and general formula (II), or general formula (I) and general formula (III), or general formula (II) and general formula (III), or general formula (I), general formula (II), and general formula (III), wherein n is an integer from 2 to 2000, preferably 2 to 100. The repeating units of general formula (I) or general formula (II) or general formula (III), or the repeating units of general formula (I) and general formula (II), or the repeating units of general formula (I) and general formula (III), or the repeating units of general formula (II) and general formula (III), or the repeating units of general formula (I), general formula (II), and general formula (III) may be the same or different from each other in the polythiophene. Preferably, in each case, the polythiophene has the same repeating units of general formula (I) or general formula (II) or general formula (III), or in each case has the same repeating units of general formula (I) and general formula (II), or general formula (I) and general formula (III), or general formula (II) and general formula (III), or in each case has the same repeating units of general formula (I), general formula (II), and general formula (III). Particularly preferably, in each case, the polythiophene has the same repeating units of general formula (I) or general formula (II), or in each case has the same repeating units of general formula (I) and general formula (II). At the end groups, the polythiophenes preferably each carry H. In the context of the present invention, C 1 -C 5- The alkylene radical A is preferably methylene, ethylene, n-propylene, n-butylene, or n-pentylene. C 1 - C 18 - The alkyl group R is preferably a straight-chain or branched-chain C 1 - C 18 - alkyl radical, such as methyl, ethyl, n-propyl or isopropyl, n-butyl, isobutyl, secondary butyl, or tertiary butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylpropyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-hexadecyl, or n-octadecyl, C 5 - C 12 - The cycloalkyl radical R is, for example, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, or cyclodecyl, C 6 - C 14 - The aryl radical R is, for example, phenyl or naphthyl, and C 7 - C 18 - The aralkyl radical R is, for example, benzyl, o-tolyl, m-tolyl, p-tolyl, 2,3-xylyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 3,4-xylyl, 3,5-xylyl, or radical. The above list is used to illustrate the present invention by way of example and should not be regarded as exclusive. In the context of the present invention, any further substituents of the A radical and / or the R radical include a plurality of organic groups, such as alkyl, cycloalkyl, aryl, aralkyl, alkoxy, halogen, ether, thioether, disulfide, sulfoxide, sulfone, sulfonate, amino, aldehyde, ketone, carboxylate, carboxylic acid, carbonate, carboxylate salt, cyano, alkylsilane, and alkoxysilyl, and also include carboxamide groups. The polythiophene can be uncharged or cationic. In a preferred embodiment, they are cationic, where "cationic" only refers to the charge located on the polythiophene main chain. Depending on the substituents on the R radical, the polythiophene can carry positive and negative charges in the structural unit. In this case, the positive charge is on the polythiophene main chain, and the negative charge (if present) is on the R radical substituted with a sulfonate or carboxylate group. The positive charge on the polythiophene main chain can be partially or completely saturated by anionic groups that may be present on the R radical. Overall, the polythiophene in these cases can be cationic, uncharged, or even anionic. However, in the context of the present invention, all are regarded as cationic polythiophene because the positive charge on the polythiophene main chain is important. The positive charge is not shown in the formula because its exact number and position cannot be stated clearly. However, the number of positive charges is at least 1 and at most n, where n is the total number of all repeating units (identical or different) within the polythiophene. The positive charge of the polythiophene can be balanced by an R radical substituted with a sulfonate or carboxylate and thus negatively charged (so-called "self-doped polythiophene"), or by a counter-ion (so-called "foreign-doped polythiophene"). foreign-doped polythiophene)". According to a first preferred embodiment of the polythiophene in the dispersion according to the present invention, the polythiophene is a self-doped polythiophene, which preferably contains at least 50%, even more preferably at least 75%, even more preferably at least 95%, and most preferably 100% of the repeating units of formula (IV) (IV) wherein X, Y are the same or different and represent O, S, N-R 1 where R 1 represents aryl, C 1 -C 18 -alkyl, or hydrogen; Z is an organic group with an anionic functional group, preferably an SO 3 - group, and in particular, preferably, Z represents –(CH 2 ) m –CR 2 R 3 –(CH 2 ) n –, R 2 represents hydrogen, –(CH 2 ) s –O–(CR 4 2 ) p –SO 3 - M + or –(CH 2 ) p –SO 3 - M + , R 3 represents –(CH 2 ) s –O–(C R 4 2 ) p –SO 3 - M + or –(CH 2 ) p –SO 3 - M + , M + represents a cation, m and n are the same or different and represent integers from 0 to 3, R 4 represents hydrogen or C 1 -C 10 An alkyl group, preferably a methyl group, s represents an integer from 0 to 10, and p represents an integer from 1 to 18. In this case, the above percentage numbers are intended to represent the numerical content of the units of structural formula (IV) in the doped conductive polymer in the total number of monomer units. Suitable cations M + are for example H + 、Li + 、Na + 、K + , Rb + 、Cs + 、and NH 4 + . Particularly suitable cations are Na + and K + . Particularly preferred monomers of structural formula (IV) are those in which X, Y represent O, Z represents –(CH 2 ) m –CR 2 R 3 –(CH 2 ) n –, R 2 represents hydrogen or –(CH 2 ) s –O–(CH 2 ) p –SO 3 - M + 、–(CH 2 ) p –SO 3 - M + , or –(CH 2 ) s –O–(CH 2 ) p -CHR 4 – SO 3 - M + , R 3 Indicates – (CH 2 ) s –O–(CH 2 ) p –SO 3 - M + ,–(CH 2 ) p –SO 3 - M + , or –(CH 2 ) s –O–(CH 2 ) p -CHR 4 –SO 3 - M + , M + represents a cation, m and n are the same or different, and represent integers from 0 to 3, R 4 represents hydrogen, methyl, or ethyl; s represents an integer from 0 to 10, and p represents an integer from 1 to 18. Particularly preferred monomers of structural formula (IV) are those in which X and Y represent O, Z represents –(CH 2 )–CR 2 R 3 –(CH 2 ) n –, R 2 represents hydrogen, R 3 represents –(CH 2 ) s –O–(CH 2 ) p –SO 3 - M + 、–(CH 2 ) p –SO 3 - M + 、或–(CH 2 ) s –O–(CH 2 ) p -CH(CH 3 )–SO 3 -M + 、 or –(CH 2 ) s –O–(CH 2 ) p -CH(CH 2 CH 3 )–SO 3 - M + , M + represents Na + or K + , n represents 0 or 1, s represents 0 or 1, and p represents 2, 3, 4, or 5. Suitable examples of the self-doping polymers are disclosed in WO-A-2014 / 048562 and US-A-2015 / 0337061. Specific examples of particularly preferred self-doping conductive polymers include poly(4-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]propane-1-sulfonic acid), poly(4-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]butane-1-sulfonic acid) (PEDOT-S), poly(4-[(2,3-dihydrothieno[3,4-b][1,4]dioxin-2-yl)methoxy]butane-2-sulfonic acid), or mixtures thereof. According to a second preferred embodiment of the polythiophene in the dispersion according to the present invention, the polythiophene preferably comprises an extrinsic doped polythiophene with polymeric counterions for balancing positive charges, and these polymeric counterions are also referred to as "polyanions". Thus, according to a preferred embodiment of the dispersion according to the present invention, the polythiophene comprises a cationic polythiophene with polyanions serving as the counterions of the polythiophene. Multivalent anions are preferred over monomeric anions because they contribute to film formation and, due to their size, result in a conductive film with higher thermal stability. The multivalent anions herein can, for example, be anions of polymeric carboxylic acids such as polyacrylic acid, polymethacrylic acid, or poly(maleic acid), or polymeric sulfonic acids such as polystyrene sulfonic acid and polyvinyl sulfonic acid. These polycarboxylic acids and sulfonic acids can also be copolymers of vinyl carboxylic acids and vinyl sulfonic acids with other polymerizable monomers such as acrylates and styrene. Preferred multivalent anions are anions of polymeric carboxylic acids or sulfonic acids. Particularly preferred multivalent anions are anions of polystyrenesulfonic acid (PSS), or derivatives thereof. The molecular weight of the polyacid providing the multivalent anion is preferably from 1000 to 2000000, more preferably from 2000 to 500000. The polyacid or its alkali metal salts are commercially available (e.g., polystyrene sulfonic acid and polyacrylic acid), or can be prepared by known procedures (see, for example, Houben Weyl, Methoden der organischen Chemie [Methods of Organic Chemistry], vol. E 20 Makromolekulare Stoffe [Macromolecular Substances], part 2, (1987), p. 1141 ff.). Particularly preferred specific examples of externally doped polythiophenes are complexes of poly(3,4-ethylenedioxythiophene) with anions of polystyrene sulfonic acid (PSS) (PEDOT / PSS). Further additives According to a preferred embodiment of the dispersion according to the present invention, the dispersion further comprises at least one additive, wherein the at least one additive is an additive selected from the group consisting of: binder, pH regulator, crosslinking agent, adhesion promoter, conductivity improver, surfactant, stabilizer, and combinations of at least two of such additives. - Suitable binders include organic binders that are particularly soluble in organic solvents, such as polyolefins, polyvinyl acetate, polycarbonate, polyvinyl butyral, polyacrylate, polyacrylamide, polymethacrylate, polymethacrylamide, polystyrene, polyacrylonitrile, polyvinyl chloride, polyvinyl pyrrolidone, polybutadiene, polyisoprene, polyether, polyester, polyurethane, polyamide, polyimide, polysulfone, polysilicon, epoxy resin, styrene-acrylate, vinyl acetate / acrylic ester, and ethylene / vinyl acetate copolymers, polyvinyl alcohol, or cellulose derivatives, and can also be added to the composition. Copolymers of the above polymers are also suitable as binders. - Suitable pH regulators include, for example, the bases or acids described in lines 13 to 32 on page 4 of WO 2010 / 003874 A2. Preferred are such additives that do not interfere with the film formation of the dispersion and do not volatilize at relatively high temperatures (e.g., at the soldering temperature) but remain in the solid electrolyte under such conditions. Particularly suitable are compounds of bases such as 2-dimethyl-aminoethanol, 2,2'-iminodiethanol, or 2,2',2''-nitrilotriethanol and the acid polystyrene sulfonic acid. - Suitable crosslinking agents include melamine compounds, blocked isocyanates, functional silanes (such as tetraethoxysilane), alkoxysilane hydrolyzates (such as based on tetraethoxysilane), or epoxy silanes (such as 3-glycidoxypropyl trialkoxysilane).- Suitable adhesion promoters include organofunctional silanes or their hydrolyzates, such as 3-glycidoxy-propyltrialkoxysilane, 3-amino-propyl-triethoxysilane, 3-mercapto-propyltrimethoxysilane, 3-methacryl-oxypropyl-trimethoxysilane, vinyltrimethoxysilane, or octyltriethoxysilane. - Suitable conductivity improvers include compounds such as the following: for example, tetrahydrofuran, compounds containing lactone groups (such as butyrolactone, valerolactone), compounds containing amide or lactam groups (such as caprolactone, N-methylcaprolactone), N,N-dimethylacetamide, N-methylacetamide, N,N-dimethylformamide (DMF), N-methylformamide, N-methylformanilide, N-methylpyrrolidone (NMP), N-n-octylpyrrolidone, pyrrolidone, sulfones and sulfoxides (such as, for example, sulfolane (tetramethylsulfone), dimethyl sulfoxide (DMSO)), sugars or sugar derivatives (such as, for example, sucrose, glucose, fructose, lactose), sugar-based surfactants (such as, for example, Tween or Span 60), sugar alcohols (such as, for example, sorbitol), mannitol, furan derivatives (such as, for example, 2-furoic acid, 3-furoic acid), and / or diols or polyols (such as, for example, ethylene glycol, glycerol, diethylene glycol or triethylene glycol, or polyglycerol). Ethylene glycol, diethylene glycol, triethylene glycol, polyglycerol, dimethyl sulfoxide, or sorbitol is particularly preferably used as a conductivity-improving additive. - Suitable surfactants include anionic surfactants (such as, for example, alkylbenzenesulfonic acid and alkylbenzenesulfonates, paraffin sulfonates, alcohol sulfonates, ether sulfonates, sulphosuccinate, phosphate esters, alkyl ether carboxylic acid, or carboxylates), cationic surfactants (such as, for example, quaternary alkylammonium salts), nonionic surfactants, especially nonionic amphiphilic surfactants (such as, for example, linear or branched alcohol ethoxylates, oxo alcohol ethoxylates, alkylphenol ethoxylates, or alkyl polyglucosides).Representative examples of suitable surfactants include fluorinated surfactants such as ZONYL. ® Surfactants, including ZONYL ® FSN, ZONYL ® FSO, ZONYL ® FSA, ZONYL ® FSH (DuPont Chemicals, Wilmington, Del.), and NOVEC ® (3M, St. Paul, Minn.). Other exemplary surfactants include nonionic surfactants based on alkylphenol ethoxylates. Preferred surfactants include, for example, octylphenol polyoxyethylene ethers such as TRITON ® ) and secondary alcohol ethoxylate (such as TERGITOL ® 15-S series (Dow Chemical Company, Midland Mich.)). Further exemplary nonionic surfactants include alkynyl surfactants, n-dodecyl β-D-maltoside, and alcohol ethoxylates such as TERGITOL ®TMN). - Preferred stabilizers are those compounds mentioned in WO 2012 / 041507 A1, among which particularly preferred are aromatic compounds containing at least two OH groups and one other functional group having a heteroatom different from carbon. Examples of suitable stabilizers are 3,4,5-trihydroxybenzoic acid and its derivatives, such as 3,4,5-trihydroxybenzoic acid esters (gallic acid esters), especially alkyl esters, alkenyl esters, cycloalkyl esters, cycloalkenyl esters, aryl esters, which preferably have 1 to 15 C atoms in the aryl or alkyl of the ester in each case. Particularly preferred are gallic acid and gallic acid esterified with sugar, which are generally called tannins or gallotannins (cf. Römpp Chemie, 10th edition (1999), page 4391). Also suitable as stabilizers are the "aromatic compounds containing hydroxyl groups" mentioned in paragraph

[0049] of EP 1 798 259 A1, the "antioxidants" mentioned in paragraph

[0025] of EP 1 043 720 A1, and the "aromatic compounds without sulfonic groups and containing at least two hydroxyl groups" mentioned on pages 10 and 11 of WO 2008 / 055834 A1. Procedure for producing a capacitor According to a preferred embodiment of the procedure for preparing a layer body according to the present invention, the layer body is part of an electrolytic capacitor. In this case, the procedure comprises the following steps: A) Providing a porous electrode body made of an electrode material, wherein a dielectric layer at least partially covers the surface of this electrode material, and wherein a solid electrolyte layer at least partially covers the surface of the dielectric layer; B) Applying the dispersion according to the present invention, preferably the dispersion according to the present invention as defined in any one of its 1st to 18th embodiments, or a dispersion obtainable by procedure 1 according to the present invention, preferably by procedure 1 as defined in any one of its 1st to 7th embodiments, to at least a part of the surface of the solid electrolyte layer; C) Removing at least part of the dispersant i), for forming a polymeric outer layer at least partially covering the surface of the solid electrolyte layer; Procedure steps A): In the procedure step In A), a porous electrode body made of an electrode material is provided, wherein a dielectric layer at least partially covers the surface of the electrode material, and a solid electrolyte layer at least partially covers the surface of the dielectric layer; In principle, when manufacturing the porous electrode body, valve metal powder with a high surface area can be extruded and sintered to form the porous electrode body. In this case, an electrical contact wire preferably made of a valve metal (such as tantalum) is conventionally extruded into the porous electrode body. Then, the porous electrode body is coated with a dielectric (i.e., an oxide layer), for example, by electrochemical oxidation. As an alternative, a metal film can be etched and coated with a dielectric by electrochemical oxidation in order to obtain an anode film with porous regions. In the case of a wound capacitor, an anode film and a cathode film having porous regions forming the electrode body are separated by a separator and wound. Within the scope of the present invention, a valve metal is understood to be a metal whose oxide coating does not allow current to flow uniformly in both directions. By the voltage applied to the anode, the oxide layer of the valve metal blocks the current flow, while in the case of applying a voltage to the cathode, a可观 current that can damage the oxide layer occurs. 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 most well-known representatives of valve metals are Al, Ta, and Nb. A combination of electrical properties equivalent to a valve metal is one that has metallic conductivity, can be oxidized, and whose oxide layer provides the above-mentioned properties. For example, NbO exhibits metallic conductivity but is generally not regarded as a valve metal. However, the layer of oxidized NbO exhibits the general properties of a valve metal oxide layer, such that NbO or an alloy or compound of NbO with other elements is a general example of such a compound having electrical properties equivalent to those of a valve metal. Electrode materials made of tantalum, aluminum, and such electrode materials based on niobium or niobium oxide are preferred. Tantalum is particularly preferred as an electrode material. In order to manufacture a porous electrode body that often has porous regions, these valve metals can be sintered (for example, in powdered form) to provide a generally porous electrode body; or alternatively, a porous structure is imprinted on a metal body. The latter can be implemented, for example, by etching a film. Hereinafter, for simplicity, a body having porous regions is also referred to as porous. For example, an electrode body having porous regions is also referred to as a porous electrode body. In one aspect, the porous body can be penetrated by a plurality of channels and is thus sponge-like. This is usually the case when tantalum is used in a capacitor structure. On the other hand, pores can exist only on the surface, and the region provided below the surface pores can be formed in a void-free manner. This is usually observed when aluminum is used in a capacitor structure. For example, the porous electrode body manufactured in this way is then oxidized in a suitable electrolyte (such as phosphoric acid or ammonium adipate aqueous solution) by applying a voltage in order to form a dielectric. The magnitude of this forming voltage depends respectively on the thickness of the oxide layer to be achieved or the subsequent operating voltage of the capacitor. The preferred forming voltage is in the range of 1 to 1000 V, more preferably in the range of 10 to 200 V, even more preferably in the range of 15 to 100 V, and still more preferably in the range of 20 to 50 V. The porous electrode body used preferably has a porosity of 10% to 90%, more preferably 30% to 80%, even more preferably 50% to 80%, and an average pore diameter of 10 to 10000 nm, preferably 50 to 5000 nm, even more preferably 100 to 3000 nm. According to a particular embodiment of the process according to the invention, the electrolytic capacitor to be manufactured is an aluminum wound capacitor. In this case, in process step A), an anodic porous aluminum film is formed as the electrode material, where an aluminum oxide coating is formed as the dielectric. The aluminum film (anodic film) thus obtained is then provided with contact wires and wound with another porous aluminum film (cathodic film) which also has contact wires, where these two films are separated from each other by one or more separator papers, the separator papers being based on, for example, cellulose, or preferably synthetic paper. After winding, the anode body obtained in this way is fixed, for example, by an adhesive tape. The separator paper or the separator papers can be carbonized by heating in an oven. This manufacturing method for the anode body of an aluminum wound capacitor is well known in the prior art and is described, for example, in US 7,497,879 B2. In order to form a solid electrolyte layer that at least partially covers the surface of the dielectric layer, a conductive polymer is deposited on the dielectric in a chemical or electrochemical manner (such as by oxidative polymerization). For this purpose, the precursor for preparing the conductive polymer, one or more oxidants, and if appropriate, counter ions are applied together or successively to the dielectric of the porous electrode body and polymerized in a chemical and oxidative manner, or the precursor for generating the conductive polymer and the counter ions are polymerized on the dielectric of the porous electrode body by electrochemical polymerization. Preferably, in order to form a solid electrolyte layer that at least partially covers the surface of the dielectric layer, a dispersion containing a conductive polymer can be introduced into at least a part of the provided porous electrode body, where the dispersant is then at least partially removed for forming a solid electrolyte that at least partially covers the surface of the dielectric layer. Suitable conductive polymers for forming the solid electrolyte layer include polypyrrole, polythiophene, polyaniline, polyacetylene, polyphenylene, and poly(p-phenylene vinylene), among which polythiophene, especially the preferred polythiophene described above as the dispersion according to the invention, is preferred. The best for forming the solid electrolyte layer is cationic polythiophene in the form of a polythiophene / polyvalent anion complex, and even better in the form of a PEDOT / PSS complex; self-doped polythiophenes such as poly(4-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]propane-1-sulfonic acid), poly(4-[(2,3-dihydro-thieno-[3,4-b]-[1,4]dioxin-2-yl)methoxy]butane-1-sulfonic acid) (PEDOT-S), or poly(4-[(2,3-dihydrothieno[3,4-b][1,4]dioxin-2-yl)methoxy]butane-2-sulfonic acid), or mixtures thereof. The dispersion can be introduced into the porous region using known procedures, such as immersion, dipping, pouring, dripping, injection, spraying, spreading, painting, or printing, such as ink-jet printing, screen printing, or tampon printing. The introduction is preferably by immersing the porous electrode body in the dispersion, and is carried out by impregnating it with this dispersion. Immersion or impregnation with the dispersion is preferably carried out for a duration in the range of 1 second to 120 min, particularly preferably in the range of 10 seconds to 60 min, and most preferably in the range of 30 seconds to 15 min. The introduction of the dispersion into the anode body can be promoted, for example, by increasing or decreasing pressure, vibration, ultrasound, or heat. After the porous electrode body has been impregnated with the dispersion as described above, the dispersant is at least partially removed so that a solid electrolyte layer is formed, which partially or completely covers the dielectric. In this case, preferably, the coverage of the solid electrolyte layer on the dielectric is preferably at least 50%, particularly preferably at least 70%, and most preferably at least 80%, where the capacitance measurement of the capacitor under dry and wet conditions at 120 °C allows the determination as described in DE-A-10 2005 043 828. When removing the dispersant, it is preferably to remove the porous electrode body from the dispersion liquid and then dry it, wherein the drying is preferably carried out at a temperature in the range of 20 °C to 200 °C, particularly preferably in the range of 50 °C to 180 °C, and more preferably in the range of 80 °C to 150 °C. The drying conditions (i.e., drying time, drying pressure, and drying temperature) are preferably adjusted to ensure that when forming the solid electrolyte layer, at least 50 wt.-%, more preferably at least 75 wt.-%, even more preferably at least 90 wt.-%, even more preferably at least 95 wt.-%, and most preferably at least 99 wt.-% of the total amount of the dispersant is removed. In a particularly preferred embodiment of the process according to the invention, the drying conditions are adjusted to ensure that when forming the solid electrolyte layer, the dispersant is completely removed. Process steps B) and process steps C): In process step B), the dispersion liquid according to the invention, preferably the dispersion liquid according to the invention as defined in any one of its Examples 1 to 18, or a dispersion liquid obtainable by Process 1 according to the invention, preferably by Process 1 as defined in any one of its Examples 1 to 7, is applied to at least a part of the surface of the solid electrolyte layer. In process step C), then the dispersant is at least partially removed i) to form a polymeric outer layer that at least partially covers the surface of the solid electrolyte layer. As used herein, the term "polymeric outer (polymeric outer)" layer preferably refers to an outer layer that, although it may contain the same conductive polymer as the solid electrolyte layer, is different from the solid electrolyte layer in terms of, for example, chemical composition, conductivity, and / or properties (such as hardness, surface roughness, adhesion properties, etc.). The polymeric outer layer, which usually has a thickness in the range of 5 µm to 50 µm, serves as a mechanical buffer between the capacitor anode and the cathode-side contact, preventing the cathode-side contact from contacting the dielectric under mechanical stresses that may occur during the manufacture of the capacitor. The application of the dispersion liquid according to the invention in process step B) to at least a part of the surface of the solid electrolyte layer and the subsequent removal of the dispersant in process step C) can be done in the same manner as already described in connection with the application of the dispersion liquid for preparing the solid electrolyte layer above. In process step B) It may be advantageous to apply a crosslinking agent to at least a part of the surface of the solid electrolyte layer before applying the dispersion according to the present invention to at least a part of the surface of the solid electrolyte layer in order to improve the coverage of the polymer outer layer on the capacitor anode. Suitable crosslinking agents and their application procedures are disclosed, for example, in DE 10 2009 007 594 A1. Process steps D) Encapsulation in After the polymer outer layer has been applied, the electrolytic capacitor can be completed (specifically, encapsulated) in a manner known to those of ordinary skill in the art. In the case of tantalum electrolytic capacitors, for example, the capacitor body can be coated with a graphite layer and a silver layer as can be learned from DE-A-10 2005 043 828; while in the case of aluminum wound capacitors, corresponding to the teachings of US 7,497,879 B2, the capacitor body is built in an aluminum cup equipped with a sealing rubber and is mechanically firmly closed by flanging. The encapsulation is preferably completed by sealing the capacitor body using a resin (such as an epoxy resin or a thermoplastic resin, as disclosed in EP 0 447 165 A2). In the case of aluminum electrolytic capacitors, the encapsulation is preferably completed by providing the porous electrode body obtained in process step e) with an aluminum cup and closing it with a sealing rubber. For different embodiments of the claimed invention, the features disclosed in the claims, this specification, and the drawings can be essential both separately and in any combination with each other. Together with some exemplary illustrations, the following schematic diagrams show aspects of the present invention for enhancing the understanding of the present invention. [Figure 1] shows the structure of a layer body 100 prepared by a process for preparing a layer structure according to the present invention in a general form, such as an antistatic film. On the substrate surface of the substrate 101, in the case of an antistatic film which is usually a PE, PP, or PET layer, there is a conductive layer 102 prepared using the composition according to the present invention. [Figure 2] shows a schematic cross-sectional view of a part of a capacitor obtained by a specific embodiment of a process for preparing a layer structure according to the present invention. The capacitor includes a porous electrode body 101a which includes pores 103 and is mainly made of a porous electrode material 101b such as aluminum. On the surface of the electrode material 101b, a dielectric layer 101c is formed as a thin layer, thereby forming an anode body which is still porous and includes the electrode body 101a made of the electrode material 101b and the dielectric layer 101c. On the dielectric layer 101c, optionally after a further layer, a layer of a solid electrolyte 101d is formed such that a capacitor body is formed which includes the electrode body 101a made of the electrode material 101b, the dielectric layer 101c, and the solid electrolyte layer 101d. The solid electrolyte layer 101d is at least partially covered by a polymeric outer layer 102a (prepared using the dispersion according to the present invention). Measuring method: Solid content Weigh an empty weighing bottle with a lid (diameter 50 mm) using an analytical balance (weight A). Fill the empty weighing bottle with about 5 g of the dispersion and weigh it together with the lid (weight B). Transfer the open weighing bottle and lid separately to a drying cabinet and dry at 100 °C for 15 to 16 hours. After drying, seal the weighing bottle directly with the lid and cool it with the lid down to room temperature. Then weigh the weighing bottle together with the lid. (Weight C) Repeat the measurement a second time using a new sample. Calculate the solid content according to the following: wt.-% solid = ( C – A) × 100 / ( B – A) The solid content measurement is carried out with two separate measurements. The maximum difference allowed between the two solid content measurements is at most 0.03%. In the case of a larger difference, the measurement must be repeated. The final value is the average of the two individual measurements. Conductivity For the measurement of conductivity, 19 g of the dispersion to be analyzed was mixed with 1 g of DMSO in a beaker and stirred for 10 min. Conductivity means the reciprocal of the specific resistance. The specific resistance is calculated from the product of the surface resistance and the layer thickness of the conductive polymer layer. The surface resistance of the conductive polymer was determined according to DIN EN ISO 3915. The mixture of the polymer dispersion and DMSO was applied as a homogeneous film to a thoroughly cleaned glass substrate sized 50 mm × 50 mm by a spin coater. The coating composition was applied to the substrate by a pipette to completely cover the area and directly spun by spin coating. The spinning conditions of the coating composition were about 1,000 rpm in air for 20 s. Thereafter, a drying process was carried out on a hot plate (at 130 °C in air for 15 min). Silver electrodes with a length of 2.0 cm were vapor deposited onto the polymer layer at a distance of 2.0 cm via a shadow mask. Then, the layer was electrically separated between the electrodes in a square area from the rest of the layer by scraping out two lines with a spatula. The surface resistance between the Ag electrodes was measured with an ohmmeter (Keithley 614). At the scratched place, the thickness of the polymer layer was determined with a stylus profilometer (Dektac 150, Veeco). Particle number The particle number was measured using an Accusizer 780 SIS (PSS NICOMP, Particle Sizing Systems, Santa Barbara, California, USA) equipped with Accusizer 780 SIS software. 7.5 g of the dispersion to be analyzed was diluted with 742.5 g of high-purity water. Thus, the concentration was diluted 100-fold. The experimental parameters were set in the following manner: Injectable volume: Large volume Number of containers: 1 Pulling times: 10 times Pulling volume: 10 ml Tare Volume: 0 ml Prime Volume: 2 ml Including the first pull: Yes Channel setting: During the measurement, the particle number in 10 × 10 ml of the diluted dispersion was measured. The particle number > 1.5 µm and the particle number > 10 µm were recorded. These totals of 10 × 10 ml were reported as the particle number per 1 ml of the original dispersion to be analyzed. Particle diameter (d 50 ) Determination of The particle diameter is determined as disclosed by H. G. Müller in Colloid Polym. Sci. 267, 1113-1116 (1989). The d 50 value indicates that 50% of the total weight of all the particles of the conductive polymer in the dispersion can be assigned to those particles having a diameter less than or equal to d 50 value. Surface roughness A glass substrate with a size of 50 mm × 50 mm is thoroughly cleaned and treated with UV ozone. The dispersion to be analyzed is applied as a homogeneous film by a spin coater. The spinning conditions of the coating composition are about 1,000 rpm in air for 20 s. After that, a drying process is carried out on a hot plate (at 130 °C in air for 10 min). The surface roughness is determined using a stylus profilometer (Dektac 150, Veeco). A stylus with a diameter of 5 µm and a stylus force of 7 µg is used to scan a length of 1,000 µm at a scanning speed of 66.7 µm / sec. The surface roughness Rq is the root mean square average of the deviation of the profile height from the mean line. Rq is defined according to ISO 4287:1998 + AC 2008. Leakage current measurement Three minutes after applying a voltage of 20 V, the leakage current (DCL) is determined using a Keithley 199 multimeter. The leakage currents of 5 capacitors are measured and the average leakage current (DCL) value is determined. Average value Unless otherwise mentioned, the average value corresponds to the arithmetic mean. Example Example 1 A 3L stainless steel reactor is equipped with a stirrer, an exhaust port, a material inlet at the top, an internal thermometer, an ultra-turrax, a material outlet at the bottom, and a temperature jacket connected to a thermostat. The reactor is charged with 2,186 g of deionized water and 102 g of an aqueous polystyrene sulfonic acid solution (Mw is 70,000 g / mol; solid content is 25 wt.%; total PSS solid is 25.5 g). Throughout the reaction, the reaction temperature is maintained at 10 °C. The mixture is flushed with nitrogen for 3 h. Subsequently, the mixture is degassed to 33 hPas. While operating the stirrer and ultra-turrax, 10.2 g of 3,4-ethylenedioxythiophene (71.8 mmol) is added. The solution is mixed for 30 minutes. Subsequently, 0.06 g of iron(III) sulphate and 19.0 g of sodium persulfate (79.8 mmol) dissolved in 50 g of water are added through the material inlet, and the solution is stirred and dispersed under reduced pressure for an additional 23 h. After 23 h, the reactor is brought to atmospheric pressure. The dispersion is transferred to a 3L beaker. Inorganic salts are removed by adding 290 ml of a cation exchanger (Lewatit S108H, Lanxess AG) and 500 ml of an anion exchanger (Lewatit MP 62, Lanxess AG) to the dispersion. The mixture is stirred for 2 h. A 400 µm sieve (E-D-Schnellsieb mittel 400my; Drefi Drehkopf & FIDI GmbH; Germany) is used to remove the ion exchange resin. This dispersion is called "dispersion 1". Dispersion 1 is filtered using a 125 µm sieve (E-D-Schnellsieb super fein 125my; Drefi Drehkopf & FIDI GmbH; Germany). The resulting "dispersion 1A" shows the following properties: Solid content: 1.2 wt.-% Dispersion 1A is then additionally filtered using a 10 µm filter (Pall DFA4001J100) at a pressure of 0.3 bar. The resulting dispersion shows the following properties: Conductivity: 534 S / cm 80 g of the dispersion filtered through a 10 µm filter, 3 g of a sulfonate polyester (Eastek 1100, Eastman), and 4 g of dimethyl sulfoxide were vigorously mixed in a glass beaker with a stirrer for one hour. The properties of the resulting "(dispersion 1B)" according to the present invention are summarized in Table 1. Example 2 A dispersion identical to dispersion 1A was prepared. 300 g of the dispersion was filtered using a 4.5 µm filter (Pall DFA4001J045) at a pressure of 3 bar. The resulting "(dispersion 2A)" showed the following properties: Conductivity: 523 S / cm 80 g of the dispersion 2A, 3 g of a sulfonate polyester (Eastek 1100, Eastman), and 4 g of dimethyl sulfoxide were vigorously mixed in a glass beaker with a stirrer for one hour. The properties of the resulting "(dispersion 2B)" according to the present invention are summarized in Table 1. Example 3 300 g of the dispersion 1A was placed in a beaker. The beaker was placed in a water / ice bath. An Ultra-Turrax (IKA T 25 basic) was placed in the dispersion and stirred at 6500 rpm for 1 h. The resulting dispersion was filtered using a 4.5 µm filter (Pall DFA4001J045) at a pressure of 1.5 bar. The resulting dispersion was designated as "(dispersion 3A)". 80 g of the dispersion 3A, 3 g of a sulfonate polyester (Eastek 1100, Eastman), and 4 g of dimethyl sulfoxide were vigorously mixed in a glass beaker with a stirrer for one hour. The properties of the resulting "(dispersion 3B)" according to the present invention are summarized in Table 1. Example 4 A dispersion identical to dispersion 1A was prepared. 500 g of the dispersion was homogenized once using a high-pressure homogenizer operating at 1500 bar. The dispersion was then filtered using a 4.5 µm filter (Pall DFA4001J045) at a pressure of 1.0 bar. The resulting "(dispersion 4A)" showed the following properties: Conductivity: 530 S / cm 80 g of the dispersion 4A, 3 g of sulfonate polyester (Eastek 1100, Eastman), and 4 g of dimethyl sulfoxide were vigorously mixed in a glass beaker with a stirrer for one hour. Properties of the (non-invention-based) "Dispersion 4B" are summarized in Table 1. Example 5 Preparation of a dispersion identical to Dispersion 1A. The dispersion was homogenized 10 times using a high-pressure homogenizer operating at 1500 bar. 2,000 g of the dispersion was filtered through a 4.5 µm filter (Pall DFA4001J045) at a pressure of 1.0 bar. The resulting dispersion was designated as "Dispersion 5A". 80 g of the dispersion 5A, 3 g of sulfonate polyester (Eastek 1100, Eastman), and 4 g of dimethyl sulfoxide were vigorously mixed in a glass beaker with a stirrer for one hour. Properties of the (non-invention-based) "Dispersion 5B" are summarized in Table 1. Example 6 Preparation of a dispersion identical to Dispersion 1. 80 g of this dispersion, 3 g of sulfonate polyester (Eastek 1100, Eastman), and 4 g of dimethyl sulfoxide were vigorously mixed in a glass beaker with a stirrer for one hour. Properties of the (non-invention-based) "Dispersion 6B" are summarized in Table 1. Example 7 44 g of the dispersion 5B was mixed with 6 g of the dispersion 6B. This mixture was designated as "Dispersion 7B". Properties of the (invention-based) Dispersion 7B are summarized in Table 1. Example 8 Place 2.5 L of water in a 5 L round-bottom flask equipped with a stirrer and a thermometer. Add 214.2 g of p-toluenesulfonic acid monohydrate and 2.25 g of iron(III) tosylate, and stir for 30 min at room temperature. Then add 85.8 g of vinylenedioxythiophene and stir for 30 min. Subsequently, add 192.9 g of sodium persulfate with stirring. Stir the mixture for an additional 24 h at room temperature. Collect the resulting PEDOT / toluenesulfonic acid powder on a porcelain suction filter and wash with 3 L of deionized water. Then dry the powder at 100 °C for 6 h. Obtain 89 g of black PEDOT / toluenesulfonic acid powder. Mix 1 g of PEDOT / toluenesulfonic acid powder with 99 g of dispersion 5A for 30 min. Mix 80 g of this dispersion, 3 g of sulfonated polyester (Eastek 1100, Eastman), and 4 g of dimethyl sulfoxide strongly in a glass beaker with a stirrer for one hour. This mixture is called dispersion 8B. The properties of the dispersions (not according to the present invention) are summarized in Table 1. of 8B. Example 9 Mix 0.25 g of PEDOT / toluenesulfonic acid powder prepared as in Example 8 with 99.75 g of dispersion 1A for 30 min. Mix 80 g of this dispersion, 3 g of sulfonated polyester (Eastek 1100, Eastman), and 4 g of dimethyl sulfoxide strongly in a glass beaker with a stirrer for one hour. This mixture is called "dispersion 9B". The properties of the dispersions (not according to the present invention) are summarized in Table 1. of 9B. Example 10 Mix 46 g of dispersion 5B with 4 g of dispersion 6B. This mixture is "dispersion 10B". The properties of the dispersions (according to the present invention) are summarized in Table 1. of 10B Example 11 Prepare a dispersion identical to dispersion 1A. Filter 100 g of the dispersion using a 25 µm filter mesh (Schwegmann Filtrations-Technik; Polyamid Monofilament 25 µm). 80 g of the resulting dispersion, 3 g of a sulfonate polyester (Eastek 1100, Eastman), and 4 g of dimethyl sulfoxide were vigorously mixed in a glass beaker with a stirrer for one hour. This dispersion is designated as "dispersion 11B". The properties of "dispersion 11B" are summarized in Table 1 (according to the present invention). Example 12 60 g of dispersion 11B was mixed with 30 g of dispersion 1B. This mixture is "dispersion 12B". The properties of dispersion 12B (according to the present invention) are summarized in Table 1. Example 13 A 300 g dispersion identical to dispersion 3A was prepared. The dispersion was passed through a 4.5 µm filter (Pall DFA4001J045) twice at a pressure of 1.4 bar. The resulting dispersion is designated as "dispersion 13A". 80 g of the resulting dispersion, 3 g of a sulfonate polyester (Eastek 1100, Eastman), and 4 g of dimethyl sulfoxide were vigorously mixed in a glass beaker with a stirrer for one hour. This dispersion is designated as "dispersion 13B". The properties of "dispersion 13B" are summarized in Table 1 (according to the present invention). Table 1 summarizes the results of Examples 1 to 13: i. = according to the present invention; n. i. = not according to the present invention Example 14 Procedure for preparing a capacitor Procedure steps A): Tantalum powder having a specific capacitance of 50,000 CV / g was pressed into pellets containing tantalum wire and sintered to form a porous electrode body having dimensions of 1.5 mm × 2.9 mm × 4.0 mm. The porous electrode body was anodized in a phosphoric acid electrolyte at 30 V to form a dielectric to obtain a capacitor body. The capacitor body was immersed in an aqueous poly(3,4-ethylenedioxythiophene) / polystyrene sulfonate solution (Clevios K Nano LV, Heraeus Deutschland) for 1 min. After that, it was dried at 120 °C for 10 min. The immersion and drying were carried out nine more times to obtain a PEDOT / PSS-based solid electrolyte layer. Process steps B) and process steps C): By process steps B) and process steps C), an external polymer layer on the capacitor body was obtained. In process step B), the capacitor body of process step A) was immersed in a crosslinking agent solution (Clevios K Primer W15, Heraeus Deutschland). After that, it was dried at 120 °C for 10 min. Subsequently, the capacitor body was immersed in the dispersion of Example 1 1B. After that, in process step C), it was dried at 120 °C for 10 min. Next, the capacitor body of process step C) was covered with a graphite layer and then with a silver layer in order to obtain the finished capacitor in this way. The average leakage current of the capacitor (according to the present invention) is given in Table 2. Example 15 A capacitor was produced and evaluated in the same manner as in Example 14, but using the dispersion of Example 2 2B instead of the dispersion of Example 1 1B in process step B). The average leakage current of the capacitor (according to the present invention) is given in Table 2. Example 16 A capacitor was produced and evaluated in the same manner as in Example 14, but using the dispersion of Example 3 3B instead of the dispersion of Example 1 1B in process step B). The average leakage current of the capacitor (according to the present invention) is given in Table 2. Example 17 A capacitor was produced and evaluated in the same manner as in Example 14, but using the dispersion of Example 4 4B instead of the dispersion of Example 1 1B in process step 1B. The average leakage current of the capacitors (not according to the present invention) is given in Table 2. Example 18 The capacitors were produced and evaluated in the same manner as in Example 14, but using the dispersion of Example 5 5B, instead of the dispersion of Example 1 in Procedure Step B) 1B. The average leakage current of the capacitors (not according to the present invention) is given in Table 2. Example 19 The capacitors were produced and evaluated in the same manner as in Example 14, but using the dispersion of Example 6 6B, instead of the dispersion of Example 1 in Procedure Step B) 1B. The average leakage current of the capacitors (not according to the present invention) is given in Table 2. Example 20 The capacitors were produced and evaluated in the same manner as in Example 14, but using the dispersion of Example 7 7B, instead of the dispersion of Example 1 in Procedure Step B) 1B. The average leakage current of the capacitors (according to the present invention) is given in Table 2. Example 21 The capacitors were produced and evaluated in the same manner as in Example 14, but using the dispersion of Example 8 8B, instead of the dispersion of Example 1 in Procedure Step B) 1B. The average leakage current of the capacitors (not according to the present invention) is given in Table 2. Example 22 The capacitors were produced and evaluated in the same manner as in Example 14, but using the dispersion of Example 9 9B, instead of the dispersion of Example 1 in Procedure Step B) 1B. The average leakage current of the capacitors (not according to the present invention) is given in Table 2. Example 23 The capacitors were produced and evaluated in the same manner as in Example 14, but using the dispersion of Example 10 10B, instead of the dispersion of Example 1 in Procedure Step B) 1B. The average leakage current of the capacitors (according to the present invention) is given in Table 2. Example 24 Capacitors were produced and evaluated in the same manner as in Example 14, but using the dispersion of Example 11 11B, rather than the procedure step of the dispersion of Example 1 in B) 1B. The average leakage current of the capacitors (according to the present invention) is given in Table 2. Example 25 Capacitors were produced and evaluated in the same manner as in Example 14, but using the dispersion of Example 12 12B, rather than the procedure step of the dispersion of Example 1 in B) 1B. The average leakage current of the capacitors (according to the present invention) is given in Table 2. Example 26 Capacitors were produced and evaluated in the same manner as in Example 14, but using the dispersion of Example 13 13B, rather than the procedure step of the dispersion of Example 1 in B) 1B. The average leakage current of the capacitors (according to the present invention) is given in Table 2. Table 2 summarizes the results of Examples 9 to 16: i. = according to the present invention; n. i. = not according to the present invention 100: laminate 101: substrate 101a: porous electrode body 101b: electrode material 101c: dielectric 101d: solid electrolyte layer 102: conductive layer 102a: polymeric outer layer 103: pore Together with some illustrative diagrams, the following schematic diagrams show aspects of the present invention for enhancing the understanding of the present invention. [FIG. 1] shows the structure of a laminate 100 prepared by a procedure for preparing a layer structure according to the present invention in a general form, such as an antistatic film. [FIG. 2] shows a schematic cross-sectional view of a part of a capacitor obtained by a specific embodiment of a procedure for preparing a layer structure according to the present invention. 101a: porous electrode body 101b: electrode material 101c: dielectric 101d: solid electrolyte layer 102a: polymeric outer layer 103: pore

Claims

1. A dispersion comprising i) a dispersant; ii) at least one polythiophene dispersed in the dispersant i); wherein the dispersion comprises particles having a particle size of 1.5 µm or greater, the total number of such particles being in the range of 20,000 to 1,000,000 per ml; wherein the dispersion comprises more than 1,500 particles per ml, such particles having a particle size of 10 µm or greater; wherein a conductive layer prepared from the dispersion has a surface roughness Rq in the range of 4 nm to 23 nm; wherein the polythiophene is present in the form of particles comprising a complex of the polythiophene and a polyvalent anion; and wherein the number and size of such particles refer to the number and size of such particles comprising a complex of the polythiophene and a polyvalent anion.

2. The dispersion of claim 1, wherein the dispersion contains 100,000 to 900,000 particles per ml, the particles having a particle size of 1.5 µm or greater; and wherein a conductive layer prepared from the dispersion has a surface roughness Rq in the range of 4 nm to 10 nm.

3. A dispersion as claimed in claim 1 or 2, wherein the dispersion contains more than 2,000 particles per ml, the particles having a particle size of 10 µm or larger.

4. A dispersion as claimed in claim 1 or 2, wherein the dispersant i) comprises water.

5. The dispersion of claim 1, wherein the polythiophene is poly(3,4-vinyldioxythiophene) and wherein the polyvalent anion is the anion of polystyrene sulfonic acid.

6. The dispersion of claim 1, wherein the weight-average diameter (d50) of the particles of the complex containing polythiophene and polyvalent anions is in the range of 10 nm to 500 nm.

7. The dispersion of claim 1 or 2, wherein a conductive layer prepared from the dispersion has a conductivity of at least 10 S / cm.

8. The dispersion of claim 1 or 2, wherein the dispersion has a solid content of at least 1 wt.% based on the total weight of the dispersion.

9. A procedure for preparing a body (100) comprising the following procedure steps: A) providing a substrate (101); B) applying a dispersion of any one of claims 1 to 8 to at least a portion of the surface of the substrate (101); C) removing at least partially the dispersion i) to obtain a body (100) comprising a conductive layer (102) applied to at least a portion of the surface of the substrate (101).

10. The procedure of claim 9, wherein the layer (100) is part of a solid electrolyte capacitor, wherein the substrate (101) is a porous electrode body (101a) made of an electrode material (101b), wherein a dielectric layer (101c) at least partially covers the surface of the electrode material (101b), wherein a solid electrolyte layer (101d) at least partially covers the surface of the dielectric layer (101c), and wherein the conductive layer (102) is a polymeric outer layer (102a) at least partially covering the surface of the solid electrolyte layer (101d).

11. The procedure of claim 10, wherein the procedure comprises the following steps: A) providing a porous electrode body (101a) made of an electrode material (101b), wherein a dielectric layer (101c) at least partially covers the surface of the electrode material (101b), and wherein a solid electrolyte layer (101d) at least partially covers the surface of the dielectric layer (101c); B) applying a dispersion of any one of claims 1 to 8 to at least a portion of the solid electrolyte layer (101d); C) at least partially removing the dispersant i) for forming a polymeric outer layer (102a) at least partially covering the surface of the solid electrolyte layer (101d).

12. A layer that can be obtained by means of any of the procedures in claims 9 to 11.

13. Use of a dispersion of any one of claims 1 to 8 for forming a polymeric outer layer (102a) in a solid electrolyte capacitor, wherein the solid electrolyte comprises a porous electrode body (101a) made of an electrode material (101b), a dielectric layer (101c) at least partially covering the surface of the electrode material (101b), and a solid electrolyte layer (101d) at least partially covering the surface of the dielectric layer (101c); wherein the polymeric outer layer (102a) at least partially covers the surface of the solid electrolyte layer (101d).

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