Novel polythiophene / polyanion compositions

Abstract

To provide a conductive polymer dispersion having small particles and a high conductivity, and the use of the same in the preparation of polymer capacitors.SOLUTION: A polythiophene dispersion includes: (a) a polythiophene copolymer of a first monomer of Formula I and a second monomer of Formula II, where A has a C1-C5 alkylene bridge further functionalized with at least one functional group selected from among sulfonic acid, phosphonic acid, phosphate ester, sulfate ester, carboxylic acid, and salts of them, and B has a C1-C5 alkylene bridge, where a molar ratio of the first monomer to the second monomer is from 1 / 4 to 4 / 1; (b) a polymeric polyanion having specific substituents; where a molar ratio of the functional groups of the polyanion to the sum of A and B is from 1.1 to 1.75.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to novel polythiophene / polyanion compositions and their use in various applications, such as polymer capacitors. [Background technology]

[0002] Environmental concerns about greenhouse gas emissions are driving demand for battery electric vehicles and (plug-in) hybrid electric vehicles with increased battery capacity. The control devices in these automotive electronics contain some so-called polymer capacitors.

[0003] Polymer hybrid aluminum electrolytic capacitors are commonly used in this field. These capacitors consist of an etched aluminum / aluminum oxide (Al / Al2O3) foil that serves as the electrode and dielectric layer, and the Al / Al2O3 foil is coated with a conductive polymer layer that functions as the counter electrode. Poly(3,4-ethylenedioxy-thiophene):poly(styrenesulfonate) (PEDOT:PSS) is commonly used, a conductive polymer composite that is coated onto an Al / Al2O3 substrate by dip coating from an aqueous dispersion.

[0004] A key aspect of the fabrication of these capacitors is the infiltration of conductive polymer particles into the Al / Al2O3 foil. To increase the surface area, the Al foil is etched, and then the etched Al foil is anodized to provide a thin layer of Al2O3. This process creates a porous Al / Al2O3 substrate, which is then dip-coated with an aqueous PEDOT:PSS dispersion. Therefore, the particle size of the conductive polymer particles determines the polymer's ability to infiltrate into the pores of the Al / Al2O3 substrate. Therefore, the smaller the particle size of the conductive polymer dispersion, the better the coverage and the lower the equivalent series resistance (ESR) of the capacitor.

[0005] Reducing the particle size of these PEDOT:PSS dispersions can be achieved by varying the relative amounts of the two polymers in the composite. For polymer capacitor fabrication, a PEDOT:PSS mass ratio of 1:2.5 is typically used, as this provides a balance between properties (e.g., the surface resistivity of the PEDOT:PSS layer and the particle size of the PEDOT:PSS dispersion). Increasing the amount of PSS results in smaller particles but significantly increases the surface resistivity (Conjugated Polymers, 3rd Edition, 2007, CRC Press). Alternatively, decreasing the amount of PSS reduces the surface resistivity but significantly increases the viscosity, particle size, and number of aggregates (>5 μm) of the PEDOT:PSS dispersion.

[0006] Patent document 1 (Heraeus) discloses various PEDOT:PSS ratios and their use in polymer capacitors. The PEDOT:PSS ratio is preferably between 0.67 and 1.5. However, the conductivity is lower compared to that of a reference material with a PEDOT:PSS mass ratio of 1:2.5. No effect on particle size is reported.

[0007] Patent document 2 (Shin-Etsu Polymer) discloses various PEDOT:PSS ratios. It is reported that materials with reduced PSS content have increased conductivity. The effect on particle size of PEDOT:PSS is not reported.

[0008] Patent document 3 (Kemet) also describes PEDOT:PSS dispersions with different ratios of the two polymers, where the particle size of PEDOT:PSS is reduced by increasing the amount of PSS and changing the synthesis method.

[0009] Patent Document 4 (Agfa Gevaert / Heraeus) discloses the synthesis and polymerization of 4-(2,3-dihydrothieno[3,4-b][1,4]dioxin-3-ylmethoxy)butane-1-sulfonic acid (EDOT-S). Because EDOT-S contains a covalently bound sulfonic acid, thiophene polymers prepared using such monomers do not need to be stabilized in water with polyanions (e.g., PSS). Monomers containing anionic groups or their salts are often referred to as self-doping EDOT monomers.

[0010] US Pat. No. 5,629,999 (Heraeus) discloses a method for preparing water-soluble thiophene polymers using self-doped EDOT derivatives (eg, EDOT-S).

[0011] US Pat. No. 6,299,649 (Kemet) discloses a polymer capacitor containing a self-doped polythiophene (referred to in the document as an intrinsically conductive polymer).

[0012] Patent document 7 (Tosoh) describes the synthesis and polymerization of various self-doping EDOT monomers (EDOT-S and branched alkyl alternatives of EDOT-S). These polymers are water-soluble and do not require stabilization in water with polyanions. However, the reported conductivities are often an order of magnitude lower than those of PEDOT:PSS dispersions. Another disadvantage of these conductive polymers is the high cost of their preparation.

[0013] Patent document 8 (Agfa Gevaert) discloses, inter alia, copolymers of EDOT and EDOT-S, however the amount of PSS is constant in all copolymers.

[0014] Patent document 9 (Tosoh) describes copolymers of the above-mentioned branched alkyl substitutes for EDOT-S with at least one other thiophene monomer. PSS is not used because the resulting copolymers are water-soluble. The conductivity is low compared to that of PEDOT:PSS dispersions.

[0015] Patent Document 10 (Tayca) discloses the combination of a copolymer of alkylated EDOT derivatives and EDOT with PSS and its use in capacitors. Copolymers with different molar ratios of EDOT and EDOT derivatives are prepared, but the amount of PSS remains constant. No effect on particle size is described.

[0016] US Patent No. 5,999,949 (Heraeus) discloses a process for producing polymer capacitors using both self-doped (e.g., prepared from EDOT-S) and externally doped polythiophene polymers (e.g., PEDOT:PSS).

[0017] Therefore, there is a need for conductive polymer dispersions that result in low surface resistance and smaller particle sizes for making polymer capacitors. [Prior art documents] [Patent documents]

[0018] [Patent Document 1] International Publication No. 2014 / 048561 [Patent Document 2] Patent Application No. 2020-202123 [Patent Document 3] International Publication No. 2020 / 040851 [Patent Document 4] European Patent Application Publication No. 1122274 [Patent Document 5] European Patent Application Publication No. 3037497 [Patent Document 6] US Patent Application Publication No. 2016 / 351339 [Patent Document 7] US Patent Application Publication No. 2015 / 337061 [Patent Document 8] European Patent Application Publication No. 1458785 [Patent Document 9] International Publication No. 2015 / 194657 [Patent Document 10] European Patent Application Publication No. 2508547 [Patent Document 11] European Patent Application Publication No. 2901464 Summary of the Invention

[0019] It is an object of the present invention to provide a conductive polymer dispersion with small particles and high conductivity, and its use in the preparation of polymer capacitors.

[0020] The object of the present invention is achieved by a dispersion according to claim 1.

[0021] Further objects of the present invention will become apparent from the remainder of this specification. DETAILED DESCRIPTION OF THE INVENTION

[0022] definition The term "monofunctional" (eg, "monofunctional" in a polymerizable monofunctional compound) means that the polymerizable compound contains one polymerizable group.

[0023] The term "difunctional" (eg, the term "difunctional" in a polymerizable difunctional compound) means that the polymerizable compound contains two polymerizable groups.

[0024] The term "multifunctional" (eg, the term "multifunctional" in a polymerizable multifunctional compound) means that the polymerizable compound contains three or more polymerizable groups.

[0025] The term "alkyl" refers to all possible variations of alkyl groups of each carbon number, namely methyl, ethyl, n-propyl and isopropyl for those with 3 carbon atoms, n-butyl, isobutyl and tertiary butyl for those with 4 carbon atoms, n-pentyl, 1,1-dimethylpropyl, 2,2-dimethylpropyl and 2-methylbutyl for those with 5 carbon atoms, and so forth.

[0026] Unless otherwise specified, a substituted or unsubstituted alkyl group is preferably a C1-C6 alkyl group.

[0027] Unless otherwise specified, a substituted or unsubstituted alkenyl group is preferably a C2-C6 alkenyl group.

[0028] Unless otherwise specified, a substituted or unsubstituted alkynyl group is preferably a C2-C6 alkynyl group.

[0029] Unless otherwise specified, a substituted or unsubstituted alkaryl group is preferably a phenyl or naphthyl group containing one, two, three, or more C1-C6 alkyl groups.

[0030] Unless otherwise specified, substituted or unsubstituted aralkyl groups are preferably C7-C8, including phenyl or naphthyl groups. 20 It is an alkyl group.

[0031] Unless otherwise specified, a substituted or unsubstituted aryl group is preferably a phenyl or naphthyl group.

[0032] Unless otherwise specified, a substituted or unsubstituted heteroaryl group is preferably a 5- or 6-membered ring substituted by 1, 2, or 3 oxygen, nitrogen, sulfur, or selenium atoms, or a combination thereof.

[0033] Unless otherwise specified, a substituted or unsubstituted alkylene group is preferably a C1-C6 alkylene group.

[0034] The term "substituted" (e.g., "substituted" in a substituted alkyl group) means that the alkyl group may be substituted with atoms other than those normally present in such a group (i.e., carbon and hydrogen). For example, a substituted alkyl group may contain a halogen atom or a thiol group. An unsubstituted alkyl group contains only carbon and hydrogen atoms.

[0035] Unless otherwise specified, substituted alkyl, alkenyl, alkynyl, aralkyl, alkaryl, aryl, and heteroaryl groups are preferably substituted with one or more members selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and tert-butyl, ester, amide, amine, ether, thioether, ketone, aldehyde, sulfoxide, sulfone, sulfonate ester, sulfonamide, -Cl, -Br, -I, -OH, -SH, -CN, and -NO2.

[0036] Conductive polymer dispersion Herein, a dispersion containing a conductive polymer is referred to as a conductive polymer dispersion.

[0037] The conductive polymer dispersion according to the present invention comprises a polyanion and a conductive polymer as described below.

[0038] The dispersion medium of the conductive polymer dispersion is preferably selected from water, a water-soluble organic solvent, or a mixture thereof. Preferred organic solvents are protic organic solvents (such as alcohols or acids). The dispersion medium is preferably water.

[0039] The conductive polymer dispersion may contain other ingredients, such as a dispersant.

[0040] The conductive polymer dispersion is preferably prepared as described below.

[0041] The conductive polymer dispersion is (a) Formula I [ka] and a monomer of formula II [ka] a polythiophene copolymer with a monomer of During the ceremony, A represents a substituted or unsubstituted C1-C5 alkylene bridge further functionalized with at least one group selected from the group consisting of sulfonic acid or salts thereof, phosphonic acid or salts thereof, phosphate ester or salts thereof, sulfate ester or salts thereof, and carboxylic acid or salts thereof; B represents a substituted or unsubstituted C1-C5 alkylene bridge, provided that B is not further functionalized with a pH-responsive group; a polythiophene copolymer, wherein the molar ratio of the monomer of formula I to the monomer of formula II is 1 / 4 to 4 / 1; (b) a polymeric polyanion, wherein at least 75 mol % of the monomer units of the polyanion contain a substituent selected from the group consisting of sulfonic acid or salts thereof, phosphonic acid or salts thereof, phosphate ester or salts thereof, sulfate ester or salts thereof, and carboxylic acid or salts thereof; Including, The polyaniline relative to the total of the monomer units of formula I and formula II of the polythiophene The molar ratio of the functional groups to the ions is 1.1 to 1.75.

[0042] The feature "alkylene bridge functionalized with a group" as used herein for formula I and formula II means that the group is covalently coupled to the alkylene bridge, optionally via a divalent linking group having up to 20 C atoms. Preferred linking groups are alkylene groups or ether groups having up to 20 C atoms.

[0043] As used herein, the term C1-C5 alkylene bridge means an alkylene bridge containing from 1 to 5 carbon atoms.

[0044] The molar amount is defined as the ratio of the molar content of monomers in the polymeric polyanion having functional groups selected from the group consisting of sulfonic acid or salts thereof, phosphonic acid or salts thereof, phosphoric acid ester or salts thereof, sulfuric acid ester or salts thereof, and carboxylic acid or salts thereof to the total molar content of thiophene monomers.

[0045] As used herein, pH-responsive group refers to a group that can change from ionic to nonionic depending on the pH of the surrounding medium.Therefore, such pH-responsive group is acid or base.The pH-responsive group is preferably selected from sulfonic acid or its salt, phosphonic acid or its salt, phosphate ester or its salt, sulfate ester or its salt, and carboxylic acid or its salt.

[0046] The molar ratio of the monomer of formula I to the monomer of formula II is preferably 3 / 7 to 1 / 1, more preferably 35 / 65 to 45 / 55.

[0047] The molar ratio of the functional groups of the polyanion to the total of the monomer units of formula I and formula II of the polythiophene is 1.1 to 1.75, more preferably 1.25 to 1.65, and most preferably 1.4 to 1.6.

[0048] conductive polymer The conductive polymer dispersion includes a conductive polymer.

[0049] The conductive polymer is a polythiophene.

[0050] Such polythiophenes typically have a positive charge located on the backbone of the polymer, which is preferably at least partially counterbalanced by anions.

[0051] When anions are covalently attached to the polymer, such polymers are often referred to as self-doped or intrinsically conductive polymers. The monomers used to prepare such self-doped polymers (i.e., containing anionic groups) are also referred to as self-doped monomers.

[0052] When the anion is a separate compound, the polymer is typically referred to as an extrinsically doped polymer or an extrinsically conductive polymer. The anion added as a separate compound is preferably a polyanion.

[0053] The polythiophene has the formula I [ka] and a monomer of formula II [ka] is a copolymer with a monomer of During the ceremony, A represents a substituted or unsubstituted C1-C5 alkylene bridge further functionalized with at least one group selected from the group consisting of sulfonic acid or salts thereof, phosphonic acid or salts thereof, phosphate ester or salts thereof, sulfate ester or salts thereof, and carboxylic acid or salts thereof; B represents a substituted or unsubstituted C1-C5 alkylene bridge, provided that B is not further functionalized with a pH-responsive group; The molar ratio of the monomer of formula I to the monomer of formula II is 1 / 4 to 4 / 1.

[0054] Monomers of Formula I The polythiophene comprises a monomer of Formula I:

[0055] A in formula I preferably represents a C2 alkylene bridge.

[0056] The polythiophene preferably has the formula Ia [ka] and the monomer unit During the ceremony, L1 represents a divalent linking group containing 1 to 15 carbon atoms; C represents a functional group selected from the group consisting of sulfonic acid or its salt, phosphonic acid or its salt, phosphoric acid ester or its salt, sulfuric acid ester or its salt, and carboxylic acid or its salt.

[0057] C preferably represents a sulfonic acid or a salt thereof.

[0058] The polythiophene is more preferably of formula Ib [ka] and the monomer unit During the ceremony, L2 represents a divalent linking group containing up to 10 carbon atoms. M represents hydrogen or a counter ion to offset the negative charge of the sulfonic acid group.

[0059] Table 1 shows exemplary monomers of Formula I. [Table 1-1] [Table 1-2]

[0060] Monomer of Formula II B in formula II preferably represents a C2 alkylene bridge.

[0061] In a particularly preferred embodiment, the monomer unit of formula II is 3,4-ethylenedioxythiophene.

[0062] Polyanions The conductive polymer dispersion contains a polymeric polyanion, and the monomer units of the polyanion At least 75 mol % of the positions contain a substituent selected from the group consisting of sulfonic acid or salts thereof, phosphonic acid or salts thereof, phosphate ester or salts thereof, sulfate ester or salts thereof, and carboxylic acid or salts thereof.

[0063] At least 75 mol%, preferably at least 80 mol%, more preferably at least 90 mol%, and most preferably at least 99 mol% of the monomer units of the polymeric polyanion comprise a functional group selected from the group consisting of sulfonic acid or salts thereof, phosphonic acid or salts thereof, phosphate ester or salts thereof, sulfate ester or salts thereof, and carboxylic acid or salts thereof.

[0064] The functional group is preferably a sulfonic acid or a salt thereof.

[0065] The polymeric polyanion can be a copolymer of different monomers, but is preferably a homopolymer.

[0066] In a particularly preferred embodiment, the polymeric polyanion is styrene-based.

[0067] According to a particularly preferred embodiment, the polyanion is poly(4-styrenesulfonic acid) or a salt thereof.

[0068] The weight average molecular weight (Mw) of the polymer anion is not particularly limited, but is preferably 1,000 to 1,000,000 Da, more preferably 50,000 to 500,000 Da, and most preferably 100,000 to 300,000 Da.

[0069] Preparation of conductive polymers The polythiophene polymers are preferably prepared by oxidative polymerization of the above-described thiophene monomers in an aqueous medium.

[0070] In the case of externally doped polythiophenes, the oxidative polymerization is preferably carried out in the presence of a polyanion.

[0071] The concentration of the thiophene monomer in the aqueous phase medium is preferably in the range of 0.1 to 25 wt %, preferably in the range of 0.5 to 10 wt %, all based on the total weight of the aqueous reaction medium.

[0072] Suitable oxidizing agents are iron(III) salts (such as FeCl3) and iron(III) salts of aromatic and aliphatic sulfonic acids, H2O2, K2Cr2O7, KMnO4, alkali metal perborates, alkali metal or ammonium persulfates, and mixtures thereof.

[0073] Additional suitable oxidizing agents are described, for example, in Handbook of Conducting Polymers (Ed. Skotheim, TA), Marcel Dekker: New York, 1986, Vol. 1, pages 46-57.

[0074] Particularly preferred oxidizing agents are salts of peroxydisulfuric acid (e.g., K2S2O8, Na2S2O8), iron (III) salts (e.g., iron (III) chloride), or combinations thereof.

[0075] A salt of peroxydisulfate and at least one additional compound that catalyzes the cleavage of the peroxydisulfate. Mixtures of these with additional compounds (such as Fe(III) salts) are particularly preferred.

[0076] According to a particularly preferred embodiment, the oxidizing agent is a mixture of Fe2(SO4)3 and Na2S2O8.

[0077] There are various ways to prepare the aqueous reaction medium: the thiophene monomers can be dissolved or dispersed in the aqueous reaction medium, followed by the addition of the oxidizing agent(s), which may also be dissolved or dispersed in the aqueous phase, or the oxidizing agent(s) can be first dissolved or dispersed in the aqueous reaction medium, followed by the addition of the thiophene monomers, which may also be dissolved or dispersed in the aqueous phase.

[0078] When multiple oxidizing agents are used (e.g., a mixture of Fe2(SO4)3 and Na2S2O8), it is further possible to first mix one of these components with the thiophene monomer in the aqueous reaction medium, followed by the addition of the second oxidizing agent.

[0079] The oxidative polymerization is preferably carried out under an inert atmosphere as disclosed in EP-11453877 (Agfa Gevaert). The oxygen content of the reaction medium when the oxidizing agent (e.g., a salt of peroxydisulfuric acid) is added to the reaction medium is preferably less than 3 mg / liter, more preferably less than 1.5 mg / liter, and most preferably less than 0.5 mg / liter.

[0080] The concentration of oxygen in the reaction medium can be controlled by any means, such as freeze-thawing, bubbling an inert gas (such as argon, nitrogen, or helium) through the reaction medium for an extended period of time, or consuming oxygen in a sacrificial reaction under an inert gas atmosphere. The inert gas is preferably bubbling through the reaction medium until polymerization is complete, thereby maintaining the oxygen concentration below 3 mg / L.

[0081] The oxidative polymerization is preferably carried out at low pH, as disclosed in EP-A 1 384 739 (Heraeus). The pH is preferably below 1.5, more preferably below 1.00.

[0082] To adjust the pH, the acid is preferably selected from the group consisting of water-soluble inorganic acids and water-soluble organic acids. Examples of inorganic acids include hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid. Examples of organic acids include p-toluenesulfonic acid, benzenesulfonic acid, methanesulfonic acid, and trifluoromethanesulfonic acid.

[0083] The temperature of the reaction mixture is preferably 0 to 100°C, more preferably 0 to 50°C, and most preferably 5 to 30°C.

[0084] The amounts of thiophene monomer and polyanion in the reaction mixture are selected to obtain a stable polythiophene / polyanion dispersion having a solids content of preferably 0.05 to 25 wt %, more preferably 0.1 to 10 wt %, and most preferably 0.8 to 2 wt %.

[0085] After completion of the polymerization reaction, the liquid composition may be further purified, for example, by filtration, particularly ultrafiltration, and / or treatment with ion exchangers, particularly anion and cation exchangers.

[0086] After the purification step, the conductive polymer dispersion can be further optimized for its intended use. For example, when used to fabricate polymer capacitors, the polymer capacitor formulations described below can be prepared from the conductive polymer dispersions.

[0087] Various homogenization techniques can be used during the preparation of the conductive polymer. These homogenization techniques include: -ultrasonic homogenization techniques, -Pressure homogenization method, and -Mechanical homogenization method may be selected from:

[0088] Preferred mechanical homogenizers are rotor-stator homogenizers and blade homogenizers. Another mechanical homogenization technique can be the use of a spinning disc reactor.

[0089] Preferred high-pressure homogenizers (such as Gaulin or Ariete homogenizers) are those that force the dispersion through very narrow channels or orifices under pressure. Another preferred high-pressure homogenizer is a microfluidizer.

[0090] Two or more homogenizers may be used in combination, preferably in a sequential manner.

[0091] Homogenization techniques can be used before, during, and after the polymerization reaction. Such homogenization techniques can also be used during the preparation of the liquid formulations described below.

[0092] liquid formulation Depending on the application for which the conductive polymer dispersion is to be used, additional components may be added to the conductive polymer dispersion to form a liquid formulation optimized for that application.

[0093] For example, when used in the fabrication of polymer capacitors, such liquid formulations may be referred to as polymer capacitor formulations.

[0094] All or part of the additional ingredients described below may also be added to the conductive polymer dispersion described above.

[0095] In addition to the conductive polymer and polyanion described above, the formulation may further comprise additional additives, such as surfactants, adhesion promoters, crosslinking agents, binders, conductivity-enhancing compounds, heat and moisture stability improving compounds, acidic compounds, and alkaline compounds.

[0096] The surfactant compound is 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 (such as quaternary alkyl ammonium salts), nonionic surfactants (such as linear alcohol ethoxylates, oxo alcohol ethoxylates, alkylphenol ethoxylates, or alkyl polyglucosides), and - zwitterionic surfactants (compounds containing both a carboxylic acid group and a quaternary ammonium group, such as lauryl-N,N-(dimethyl-ammonio)-butyrate and lauryl-N , N-(dimethyl)-glycine betaine), compounds containing both sulfate and quaternary ammonium groups (e.g., 3-[(3-cholamidopropyl)dimethylammonio]-1-propane-sulfonate, 3-(4-tert-butyl-1-pyridinio)-1-propanesulfonate, 3-(1-pyridinio)-1-propanesulfonate, and 3-(benzyl-dimethyl-ammonio)propanesulfonate), compounds containing both phosphate and quaternary ammonium groups (e.g., hexadecylphosphocholine), compounds containing a quaternary ammonium group with an appended hydroxy group (e.g., lauryldimethylamine N-oxide), and phospholipids (consisting of a quaternary ammonium head group coupled via a phosphate group and glycerol bound to two hydrophobic fatty acids). It could be.

[0097] Particularly preferred surfactants are commercially available surfactants available under the Dynol® and Zonyl® trademarks.

[0098] Preferred adhesion promoters are organofunctional silanes or their hydrolyzates, such as 3-glycidoxypropyltrialkoxysilane, 3-amino-propyl-triethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-methacryloxypropyl-trimethoxysilane, vinyltrimethoxysilane, or octyltriethoxysilane.

[0099] Preferred crosslinking agents are melamine compounds, blocked isocyanates, functional silanes (such as tetraethoxysilane), alkoxysilane hydrolysates (such as tetraethoxysilane), and epoxy silanes (such as 3-glycidoxy-propyltrialkoxysilane).

[0100] Preferred binders are polyurethanes, polyacrylates, or polyolefins.

[0101] Preferred conductivity enhancers are compounds containing ether groups (e.g., tetrahydrofuran, etc.); - compounds containing a lactone group (such as γ-butyrolactone or γ-valerolactone), - compounds containing an amide group or a lactam group (such as caprolactam, N-methylcaprolactam, N,N-dimethylacetamide, N-methylacetamide, formamide, N,N-dimethylformamide (DMF), N-methylformamide, N-methylformanilide, N-methyl-2-pyrrolidone (NMP), N-octylpyrrolidone, 2-pyrrolidone, N-butylpyrrolidone, and N-hydroxyethylpyrrolidone), sulfones and sulfoxides, such as sulfolane (tetramethylene sulfone) or dimethyl sulfoxide (DMSO), sugars or sugar derivatives (such as arabinose, saccharose, glucose, fructose or lactose), dihydric or polyhydric alcohols (such as sorbitol, xylitol, mannitol, mannose, galactose, sorbose, gluconic acid, or ethylene glycol, di(ethylene glycol) or tri(ethylene glycol), 1,1,1-trimethylol-propane, 1,3-propanediol, 1,2-propane-diol, 1,5-pentanediol, 1,2,3-propanetriol, 1,2,4-butanetriol, or 1,2,6-hexanetriol, aromatic dihydric or polyhydric alcohols (such as resorcinol) is.

[0102] Particularly preferred conductivity enhancing compounds are selected from the group consisting of N-methyl-pyrrolidinone, N-butyl-pyrrolidone, N-hydroxyethyl-pyrrolidone, DMSO, ethylene glycol, and diethylene glycol.

[0103] Preferred stability-enhancing compounds are gallic acid derivatives.

[0104] The polymer capacitor formulation may have a pH of 1 to 14, and more preferably, a pH of 1 to 8. For corrosion-sensitive dielectrics (such as aluminum oxide or niobium oxide), the polymer capacitor formulation preferably has a pH of 2.5 to 8 to avoid damaging such dielectrics.

[0105] The pH is preferably adjusted using a base or acid as described in WO2010 / 003874, page 4, lines 13-32. Such compounds do not impair the film formation of the polymer capacitor formulation and do not volatilize even at higher temperatures (such as soldering temperatures). Preferred compounds are bases (2-dimethylaminoethanol, 2,2'-iminodiethanol, or 2,2',2"-nitrilotriethanol) and acids (polystyrene sulfonic acid).

[0106] The viscosity of polymer capacitor formulations is typically optimized depending on the application method and ranges from 0.01 to 1000 mPa·s (at 20°C and a shear rate of 100 s). -1 The viscosity may be 1 to 500 mPa·s, more preferably 1 to 250 mPa·s. For the production of aluminum wound capacitors, the viscosity is preferably 1 to 200 mPa·s, while for the production of tantalum electrolytic capacitors or aluminum stacked capacitors, the viscosity is preferably 1 to 50 mPa·s.

[0107] Viscosity adjustment can be achieved, for example, by adding a suitable rheology modifier as an additional additive.

[0108] As mentioned above, the particle size of the dispersed conductive polymer can affect the impregnation of the porous anode body. The median particle size (d 50 ) is preferably 1 to 150 nm, more preferably 2 to 50 nm, and most preferably 5 to 40 nm. 50 Particle size is preferably measured by laser diffraction or liquid phase centrifugal sedimentation (CPS).

[0109] The solids content of the polymer capacitor formulation is preferably 0.01 to 20 wt %, more preferably 0.1 to 15 wt %, and most preferably 0.25 to 10 wt %, in each case based on the total weight of the formulation.

[0110] Polymer Capacitors A polymer capacitor (also called a polymer electrolyte capacitor) is an electrolytic capacitor that contains a solid conductive polymer electrolyte.

[0111] Electrolytic capacitors use several special metals (often referred to as valve metals) that have chemical properties that allow them to form an insulating oxide layer upon anodic oxidation. By applying a positive voltage to the anode material in an electrolytic cell, an oxide barrier layer can be formed with a thickness corresponding to the applied voltage. This oxide layer acts as a dielectric in the electrolytic capacitor. To increase the capacitance of the capacitor, the anode surface is roughened, thus roughening the oxide layer surface.

[0112] To complete the capacitor, a counter electrode must be applied to the rough insulating oxide surface, which is accomplished by an electrolyte, which serves as the cathode electrode of the electrolytic capacitor.

[0113] The main difference between polymer capacitors is the anode material and its oxide used as the dielectric. -In polymer tantalum electrolytic capacitors, high-purity sintered tantalum powder is used as the anode and tantalum pentoxide (Ta2O5) is the dielectric. -In polymer aluminum electrolytic capacitors, electrochemically etched (roughened) high-purity aluminum foil is used as the anode, and aluminum oxide (Al2O3) is the dielectric.

[0114] The porous metal layer (anode) coated with its own oxide film (dielectric) is referred to herein as the porous anode body.

[0115] How to make a polymer capacitor A method for making a polymer capacitor according to the present invention includes incorporating a polymer capacitor formulation into at least a portion of a porous anode body.

[0116] The polymer capacitor formulation can be introduced into the porous anode body by any known process, such as impregnation, dipping, pouring, dripping, spraying, atomizing, knife coating, brushing, or printing (e.g., inkjet printing, screen printing, or tampon printing).

[0117] Preferably, the polymer capacitor formulation is introduced into at least a portion of the porous anode body by immersing the porous anode body in the polymer capacitor formulation, thereby impregnating the porous anode body with the liquid composition.

[0118] Immersion in or impregnation with the liquid composition is preferably carried out for a period of 1 second to 120 minutes, more preferably 5 seconds to 60 minutes, and most preferably 10 seconds to 15 minutes. Introduction of the liquid composition into the anode body can be facilitated by, for example, increased or reduced pressure, vibration, ultrasound, or heat.

[0119] After impregnation of the porous anode body with the liquid composition, the solvent contained in the liquid composition is preferably at least partially removed to obtain a solid electrolyte that completely or partially covers the dielectric, thereby forming a capacitor body. The coverage of the dielectric with the solid electrolyte is preferably at least 10%, more preferably at least 25%, and most preferably at least 50%. The coverage can be as described in DE-A-102005043828.

[0120] The solvent is preferably removed by removing the electrode assembly from the liquid composition and drying it, which drying step is preferably carried out at a temperature of 20°C to 260°C, more preferably 50°C to 220°C, and most preferably 80°C to 200°C.

[0121] The immersion and drying steps can be repeated one or several times to suit the thickness of the solid electrolyte layer deposited on the dielectric or the filling degree of the electrolyte in the electrode body to meet specific requirements.

[0122] It may be advantageous to use both self-doped and externally doped polythiophenes in the formation of the polymer cathode layer. Both types of polythiophene polymers can be combined in a single polymer capacitor formulation and incorporated as described above. However, it is preferred to incorporate both types of polythiophenes into the capacitor using different polymer capacitor formulations, each containing either self-doped or externally doped polythiophenes. Preferably, the self-doped polythiophene is first incorporated into the porous anode. The doped polythiophene is introduced into the body, followed by the introduction of an externally doped polythiophene. The use of both self-doped and externally doped polythiophenes is disclosed, for example, in WO 2014 / 048562 (Heraeus) and US 2016 / 0351338 (AVX).

[0123] After the capacitor body is produced in this manner, it can be further processed by methods and in ways known to those skilled in the art. In the case of tantalum electrolytic capacitors, the capacitor body can be coated, for example, with a polymer outer layer (as described in DE-A-102004022674 or DE-A-102009007594) and / or a graphite layer and a silver layer (as learned from DE-A-102005043828). In the case of aluminum wound capacitors, the capacitor body is assembled into an aluminum beaker, according to the teachings of US Pat. No. 7,497,879 B2, and a sealing glass is applied to the aluminum beaker, which is then mechanically tightly sealed by crimping. As a result, the capacitor can be free from dielectric defects that occur in known ways due to aging. [Example]

[0124] material All materials used in the following examples were readily available from standard sources (such as Aldrich Chemical Co. (Belgium) and Acros (Belgium)) unless otherwise specified. Deionized water was used.

[0125] EDOT is 3,4-ethylenedioxythiophene, commercially available from Heraeus.

[0126] PSS is a 5.85 wt % aqueous solution of polystyrene sulfonic acid having a Mw of 300 kDa prepared according to the method disclosed in Houben-Weyl, Methoden der organischen Chemie, Vol. E 20, Makromolekulaire Stoffe, Teil 2 (1987), page 1141.

[0127] Lewatit® MonoPlus M600 is a basic gel-type anion exchange resin commercially available from Lanxess AG.

[0128] Lewatit® MonoPlus S108H is an acidic gel-type anion exchange resin commercially available from Lanxess AG.

[0129] method Surface Resistivity Measurement The surface resistance SER was measured at room temperature using the two-point probe method.

[0130] Particle size measurement Median particle size (d 50 ) and d 90 Particle size was determined by liquid phase centrifugal sedimentation particle size analysis in a CPS instruments model MOD DC24000 UHR disc centrifuge.

[0131] Capacitance Measurement The capacitance of the capacitor was measured using a potentiostat at 120 Hz and room temperature.

[0132] ESR measurement The equivalent series resistance (ESR) was measured at 100 kHz and room temperature using a potentiostat.

[0133] Example 1 Synthesis of Monomer I-7 [ka] Sodium hydride (60 wt % dispersion in mineral oil, 11.04 g, 276 mmol) and tetrahydrofuran (THF, 68.8 mL) were added to a three-neck round-bottom flask, stirred, and placed under a nitrogen atmosphere.

[0134] To this stirred mixture was added dropwise a solution of thieno[3,4-b]-1,4-dioxin-2-methanol (34.40 g, 200 mmol) in THF (206.4 mL). The reaction was then stirred for 1 hour. A solution of 1,4-butanesultone (31.33 g, 230 mmol) in THF (68.8 mL) was then added. The reaction mixture was then refluxed for 1 hour. The reaction was then cooled to room temperature, methyl tert-butyl ether (MTBE, 500 mL) was added, and the mixture was stirred for 10 minutes.

[0135] The reaction mixture was decanted and a second portion of MTBE (500 mL) was added and the mixture was stirred for an additional 30 minutes.

[0136] The precipitate (66.5 g) was filtered, washed with MTBE, and dried under reduced pressure at 22 °C. The powder was recrystallized in a mixture of isopropanol (375 mL) and aqueous NaOH (8 wt%, 70 mL). The residue was filtered, washed with isopropanol, and dried under reduced pressure to give monomer I-7 (64.5 g, 97.6%) as an off-white powder.

[0137] Example 2 Synthesis of COPOL-01a:PSS 65.5 g of aqueous PSS solution, deionized water (325 mL), and nitric acid (4.3 g, 48.14 mmol) were mixed in a reaction vessel. Iron(III) sulfate (0.16 g, 0.4 mmol) and sodium persulfate (3.15 g, 13.24 mmol) were added.

[0138] The reaction mixture was stirred and cooled to 5° C. under a nitrogen stream for 90 minutes. The oxygen level is less than 30 ppb.

[0139] EDOT (1.36 g, 9.61 mmol) and an aqueous solution of monomer I-7 (0.80 g, 2.4 mmol in 7.3 mL of water) were added to the reaction mixture, which was stirred at 5° C. under a nitrogen atmosphere for 20 h.

[0140] The reaction mixture was treated with ion exchanger (110 g Lewatit® MonoPlus M600+60 g Lewatit® MonoPlus S108H (filtered and washed twice with 50 mL water)).

[0141] The resulting viscous mixture was subjected to high-shear homogenization (Lab Gaulin, 4 × 600 bar). The dispersion was concentrated under reduced pressure. This procedure yielded a blue COPOL-01a:PSS aqueous dispersion (1.11 wt%).

[0142] Example 3 Synthesis of COPOL-01b:PSS to COPOL-09:PSS A series of copolymerizations were carried out as described in Example 2, with varying amounts of EDOT, monomer I-7, and PSS according to Table 2.

[0143] Table 2 shows the amounts of EDOT and monomer I-7 (both in g) along with the amounts of PSS solution and water used in each case. Table 2 also shows the molar ratio of EDOT / monomer I-7. [Table 2]

[0144] Comparative Examples 1 to 5 Synthesis of PEDOT:PSS A series of polymerizations were carried out as described in Example 2, with varying amounts of EDOT and PSS according to Table 3.

[0145] Table 3 shows the amounts of EDOT, PSS, and other components used in the reaction. [Table 3]

[0146] PSS, deionized water, and nitric acid were mixed in a reaction vessel. Iron (III) sulfate and sodium persulfate were added.

[0147] The reaction mixture was stirred and cooled to 5° C. under a nitrogen stream for 90 minutes. The oxygen level was less than 30 ppb.

[0148] EDOT was added to the reaction mixture and stirred under a nitrogen atmosphere at 5° C. for 20 hours.

[0149] The reaction mixture was treated with an ion exchanger (Lewatit® MonoPlus M600 + Lewatit® MonoPlus S108H (filtered and washed twice with 50 mL of water). The resulting viscous mixture was subjected to high-shear homogenization (Lab Gaulin, 4 x 600 bar). The dispersion was concentrated under reduced pressure.

[0150] This procedure resulted in a blue PEDOT:PSS aqueous dispersion.

[0151] Comparative Example 6: Synthesis of EDOT-S homopolymer EDOT-S (10.8 g, 32.49 mmol), water (198 mL), and sulfuric acid (96%, 6.6 g, 64.98 mmol) were mixed in a reaction vessel.

[0152] The reaction mixture was stirred under nitrogen for 90 minutes at 20° C. The oxygen level was kept below 30 ppb.

[0153] An aqueous solution of iron(III) chloride (50 wt%, 6.32 g, 19.5 mmol) was added, followed by the slow addition of an aqueous solution of sodium persulfate (15 wt%, 93.2 mL, 64.98 mmol) to the reaction mixture, which was then stirred at 20°C under a nitrogen atmosphere for 3 hours.

[0154] The reaction mixture was treated with ion exchanger (245 g Lewatit® MonoPlus M600 + 145 g Lewatit® MonoPlus S108H (filtered and washed twice with 100 mL water)). The resulting viscous mixture was subjected to high shear homogenization (Lab Gaulin, 2 x 700 bar). The dispersion was This was followed by concentration under reduced pressure, yielding a blue aqueous dispersion of PEDOT-S (1.26 wt%).

[0155] Comparative Example 7: Mixture of PEDOT:PSS and PEDOT-S A 50 / 50 wt% mixture of PEDOT:PSS (as prepared in Comparative Example 1) and a homopolymer of EDOT-S was prepared and evaluated in the same manner as the P(EDOT:EDOT-S):PSS copolymer.

[0156] Example 4 The polymers prepared in Examples 2-3 and Comparative Examples 1-7 were evaluated by the characterization procedures described above, and the results are shown in Table 4.

[0157] The ratio of the molar amount of functional groups of the polyanion (in this case, the molar amount of sulfonic acid groups of PSS) to the sum of the monomer units of formula I (monomer I-7) and formula II (EDOT) of the polythiophene is expressed as [SOH groups of PSS] / [total monomers]. [Table 4]

[0158] COPOL-01a:PSS to COPOL-09:PSS have different ratios of the monomers I-7 (EDOT-S) and EDOT in the copolymer, and also different ratios of [SO3H group of PSS] / [total monomers].

[0159] COMP-01 to COMP-05 contain PEDOT homopolymers, where decreasing the amount of PSS resulted in an increase in particle size, making these conductive polymers less suitable for capacitor applications.

[0160] COMP-06 is a homopolymer of the monomer I-7 (EDOT-S) with a particle size useful for capacitor applications, but with an excessively large SER.

[0161] COMP-07 is a mixture of PEDOT:PSS and PEDOT-S. SER and particle size are too large.

[0162] The copolymers 01 to 09 of the present invention have small SER and particle size, making them particularly suitable for capacitor applications.

[0163] The best results are obtained when the copolymer has a [monomer I-7] / [EDOT] ratio of 35 / 65 to 1 / 1 and a [SO3H groups of PSS] / [total monomers] ratio of 1.6 to 1.4.

[0164] Example 5: Preparation of a capacitor A chemically modified aluminum foil containing an etching layer on the surface was prepared as a valve metal base. A dielectric layer was formed to cover the aluminum foil. The resulting chemically modified aluminum foil was used as an anode component. The rated voltage of the alumina layer was 90 V, and the capacitance was 6.4 μF / cm. 2 A 20 μm thick solder mask was printed onto Al foil to provide an array of 10 mm × 10 mm openings. This patterned foil was cut into 30 mm × 105 mm strips with five openings per strip.

[0165] The conductive polymer dispersion used in the preparation of the capacitors was formulated with water, diethylene glycol, and DYNOL™ 604 and processed by an ultrasonic homogenization step before coating on the aluminum foil.

[0166] The strips were dip-coated with the COPOL-01b:PSS dispersion and dried at 150 °C for 5 min. This dip-coating and curing step was repeated several times. Carbon paste and silver paste were then screen-printed sequentially onto the PEDOT layer and cured. The capacitance and equivalent series resistance (ESR) were measured as described above.

[0167] Additional capacitors were fabricated and measured as above, using COPOL-01c:PSS, COPOL-02:PSS, COPOL-05:PSS, and COMP-05 as the conductive polymer dispersions.

[0168] Table 5 shows a summary of the capacitor evaluation results. [Table 5]

[0169] It is clear from the results in Table 5 that the use of a dispersion using the copolymer according to the present invention increases the capacitance of the capacitor while decreasing the ESR.

Claims

1. (a) Formula I 【Chemical 1】 and a first monomer of formula II 【Chemistry 2】 and a second monomer of During the ceremony, A is a substituted or unsubstituted C further functionalized with at least one functional group selected from the group consisting of sulfonic acid or a salt thereof, phosphonic acid or a salt thereof, phosphoric acid ester or a salt thereof, sulfuric acid ester or a salt thereof, and carboxylic acid or a salt thereof. １ -C ５ represents an alkylene bridge, B is substituted or unsubstituted C １ -C ５ represents an alkylene bridge, provided that B is not further functionalized with a pH responsive group; the polythiophene copolymer, wherein the molar ratio of the first monomer to the second monomer is 1 / 4 to 4 / 1; (b) a polymeric polyanion, wherein at least 75 mol % of the monomer units of said polymeric polyanion are functionalized with a functional group selected from the group consisting of sulfonic acid or salts thereof, phosphonic acid or salts thereof, phosphoric acid ester or salts thereof, sulfuric acid ester or salts thereof, and carboxylic acid or salts thereof; A polythiophene dispersion comprising: the polythiophene dispersion, wherein the molar ratio of the functional group of the polyanion to the sum of the first monomer and the second monomer of the polythiophene copolymer is 1.1 to 1.

75.

2. 2. The polythiophene dispersion of claim 1, wherein the molar ratio of the first monomer to the second monomer is from 3 / 7 to 1 / 1.

3. 3. The polythiophene dispersion according to claim 1, wherein the molar ratio of the functional group of the polyanion to the sum of the first monomer and the second monomer of the polythiophene copolymer is 1.25 to 1.

65.

4. The first monomer is represented by formula Ia 【Chemistry 3】 and having the chemical structure During the ceremony, L １ represents a divalent linking group containing 1 to 15 carbon atoms; 4. The polythiophene dispersion according to claim 1, wherein C represents a group selected from the group consisting of sulfonic acid or a salt thereof, phosphonic acid or a salt thereof, phosphoric acid ester or a salt thereof, sulfuric acid ester or a salt thereof, and carboxylic acid or a salt thereof.

5. The first monomer is represented by formula Ib 【Chemistry 4】 and having the chemical structure During the ceremony, L ２ represents a divalent linking group containing up to 10 carbon atoms; 10. A polythiophene dispersion according to any of the preceding claims, wherein M represents hydrogen or a counterion to compensate for the negative charge of the sulfonic acid group.

6. 10. The polythiophene dispersion of any of the preceding claims, wherein the second monomer is 3,4-ethylenedioxythiophene.

7. 10. The polythiophene dispersion of any of the preceding claims, wherein the polymeric polyanion is poly(4-styrenesulfonic acid) or a salt thereof.

8. 10. The polythiophene dispersion according to any of the preceding claims, wherein the polymeric polyanion has a weight average molecular weight (Mw) of 100,000 to 300,000 Da.

9. The polythiophene and the polyanion are present as polythiophene / polyanion particles, and the median particle size (d ５０ 10. The conductive polymer dispersion according to claim 1, wherein the average particle size is 5 to 40 nm.

10. A liquid formulation comprising a conductive polymer dispersion according to any of the preceding claims.

11. 11. The liquid formulation of claim 10, wherein the formulation has a pH of from 2 to 8.

5.

12. 20°C, shear rate 100 s －１ 12. A liquid formulation according to claim 10 or 11, wherein the viscosity of the formulation, measured using a rheometer at 1000 kJ / min, is between 1 and 250 mPa.s.

13. 13. A method of fabricating a polymer capacitor comprising a porous anode body, the method comprising introducing a liquid formulation according to any one of claims 10 to 12 into at least a portion of the porous anode body.

14. Use of a liquid formulation according to any of claims 10 to 12 for the preparation of a conductive layer in an electronic device.

15. 15. The use according to claim 14, wherein the electronic device is selected from photoconductive cells, photoresistors, photoswitches, phototransistors, phototubes, IR detectors, photovoltaic devices, solar cells, coating materials for memory devices, field effect resistive devices, antistatic films, biosensors, electrochromic devices, solid electrolyte capacitors, hybrid capacitors, supercapacitors, energy storage devices, batteries, and electromagnetic shielding.

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