Composition, antistatic agent, antistatic film, method for producing polyanion, and method for producing composition

Abstract

To provide a composition, an antistatic agent, an antistatic film, a method for producing a polyanion, and a method for producing a composition.SOLUTION: Provided is a composition comprising a sulfonic acid group-containing polyanion having a weight average molecular weight (Mw) of 180,000 to 500,000 and a polydispersity index (PDI) of 1.7 or less, and a cationic polythiophene that forms a complex with the polyanion. Provided is a method for producing a polyanion, including polymerizing a sulfonic acid group-containing monomer by living radical polymerization to produce a sulfonic acid group-containing polyanion having a weight average molecular weight (Mw) of 180,000 to 500,000 and a polydispersity index (PDI) of 1.7 or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a composition, an antistatic agent, an antistatic film, a method for producing a polyanion, and a method for producing a composition. [Background technology]

[0002] Patent Document 1 discloses "a method for producing poly(3-substituted thiophene), comprising reacting a 2,5-dihalo-3-substituted thiophene compound with an organomagnesium reagent to produce a monometallated intermediate, and then adding a Ni(II) catalyst to initiate a polycondensation reaction, wherein the polycondensation reaction is carried out at 0 to 35°C to produce poly(3-substituted thiophene) having a molecular weight distribution (Mw / Mn) in the range of 1.0 to 1.4 (Claim 1)." Patent Document 2 discloses "a method for producing polystyrene sulfonic acids or salts thereof, having a molecular weight distribution [weight average molecular weight (Mw) / number average molecular weight (Mn)] of 1.3 or less and Mw in the range of 5,000 to 100,000, the method comprising: subjecting styrene sulfonate esters represented by the following formula (1) *chemical formula omitted (wherein each R1 independently represents a linear, branched or cyclic alkyl group of 1 to 12 carbon atoms, which may have a substituent, or an aryl group of 6 to 12 carbon atoms, which may have a substituent; each R2 independently represents a hydrogen atom, a halogen atom, a linear, branched or cyclic alkyl group of 1 to 12 carbon atoms, which may have a substituent, or an aryl group of 6 to 12 carbon atoms, which may have a substituent; m represents an integer of 1 to 5, n represents an integer of 0 to 4, and m+n=5), to living radical polymerization or living anionic polymerization to obtain polystyrene sulfonate esters ((1)) (wherein each R1 independently represents a linear, branched or cyclic alkyl group of 1 to 12 carbon atoms, which may have a substituent, or an aryl group of 6 to 12 carbon atoms, which may have a substituent; m represents an integer of 1 to 5, n represents an integer of 0 to 4, and m+n=5). (Claim 1)" Patent Document 3 discloses "high-purity parastyrenesulfonic acid (salt), in which the content ratios of the main impurities derived from the raw material styrene that may be contained in parastyrenesulfonic acid (salt), namely (a) orthostyrenesulfonic acid (salt), (b) β-bromoethylbenzenesulfonic acid (salt), (c) metastyrenesulfonic acid (salt), and (d) bromostyrenesulfonic acid (salt), determined by high performance liquid chromatography on a peak area basis, are (a) ≦0.20%, (b) ≦0.50%, (c) ≦3.00%, and (d) ≦0.10%, respectively (provided that the sum of the peak areas of parastyrenesulfonic acid (salt) and (a) to (d) is 100). (Claim 1)" Patent Document 4 discloses "a conductive polymer aqueous dispersion comprising a block copolymer as a dispersant and dopant, which is composed of a vinyl alcohol-based polymer segment (A) and a styrene sulfonic acid-based polymer segment (B), and a conductive polymer. (Claim 1)" Patent Document 5 discloses "a transparent electrode having a transparent conductive layer on a transparent substrate, the transparent conductive layer comprising conductive fibers and a conductive material, and the conductive material containing at least one polyanion having a molecular weight distribution (Mw / Mn) of 1.03 to 1.30. (Claim 1)" Patent Document 6 discloses "a method for producing a dispersion of conductive polymer particles, comprising the steps of: preparing a dispersion by dispersing at least one monomer selected from thiophenes and their derivatives, and a polyanion as a dopant, in a solvent containing water as a main component; and preparing a conductive polythiophene particle dispersion doped with the polyanion by mixing the dispersion with an oxidizing agent to oxidatively polymerize the monomer, wherein the polyanion is at least one of polystyrene sulfonic acid and a salt of polystyrene sulfonic acid, and the hue of an aqueous solution obtained by dissolving the polyanion in water to a concentration of 2% has a Hazen color scale of 10 or more and 1000 or less, as measured by the APHA method. (Claim 1)" Patent Document 7 states, "A method for producing a composition containing polythiophene, I) providing a composition Z1 comprising a thiophene monomer and an oxidizing agent; II) reducing the oxidizing agent to a reduction product and oxidizing the thiophene monomer, thereby oxidizing and polymerizing the thiophene monomer to form a composition Z2 comprising a polythiophene and the reduction product; III) at least partially removing the reduction product from composition Z2 obtained in step II) to obtain composition Z3; and ensuring that after step III) is completed, the content of unpolymerized thiophene monomer in composition Z3 is in the range of 1 ppm to 100 ppm based on the total weight of composition Z3. (Claim 1)" is disclosed. Patent Document 8 describes a capacitor having an anode made of a porous valve metal, a dielectric layer formed by oxidizing the surface of the anode, and a cathode formed on the dielectric layer. A capacitor characterized in that the cathode comprises a solid electrolyte layer containing a π-conjugated conductive polymer, an anionic group-containing solubilizing polymer, and a nitrogen-containing aromatic cyclic compound. (Claim 1)" is disclosed. Non-patent document 1 states that "The commercially available polyelectrolyte complex poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is ubiquitous in organic and hybrid electronics. As such, it has often been used as a benchmark material for fundamental studies and the development of new electronic devices. Yet, most studies on PEDOT:PSS have focused on its electronic conductivity in dry environments, with less consideration given to its ion transport, coupled ionic-electronic transport, and charge storage properties in aqueous environments. These properties are essential for applications in bioelectronics (sensors, actuators), charge storage devices, and electrochromic displays. Importantly, past studies on mixed ionic-electronic transport in PEDOT:PSS neglected to consider how the molecular structure of PSS affects mixed ionic-electronic transport."Herein, we therefore investigated the effect of the molecular weight and size distribution of PSS on the electronic properties and morphology of PEDOT:PSS both in dry and aqueous environments, and overall performance in organic electrochemical transistors (OECTs). Using reversible addition-fragmentation chain transfer (RAFT) polymerization with two different chain transfer agents, six PSS samples with monomodal, narrow (D = 1.1) and broad (D= 1.7) size distributions and varying molecular weights were synthesized and used as matrices for PEDOT. We found that using higher molecular weight of PSS (M. n = 145 kg mol -1 ) and broad dispersity led to OECTs with the highest transconductance (up to 16 mS) and [μC*] values (~140 F cm -1 V -1 s -1 ) in PEDOT:PSS, despite having a lower volumetric capacitance (C = 35 ± 4 F cm -3). 通过原子力显微镜 (AFM) 研究薄膜的微观结构,能最好地解释这些差异。我们发现,由高分子量和高分散性的PSS制得的PEDOT:PSS薄膜中的不均匀性(相互连接且富含PEDOT和PSS的大区域)导致了更高的电荷迁移率 (μ OECT ~ 4 cm 2 V -1 s -1 ),进而导致跨导。这些研究突出了在有机混合离子 - 电子导体中考虑分子量和尺寸分布的重要性,并可能为设计用于生物界面的高性能有机电子产品铺平道路。(摘要)」被公开。 Non-patent document 2 states that "Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is the most successful conductive polymer. In this study, we investigated the electrical properties of PEDOT:PSS prepared using poly(styrenesulfonic acid) (PSSA) having different molecular weight distributions. Herein PSSA with different molecular weight distributions were successfully polymerized by free radical polymerization and atom-transfer radical polymerization (ATRP). Polydispersity index values of PSSA obtained by the free radical process and ATRP process were 2.3-2.8 and 1.2-1.6 respectively. The electrical conductivity of PEDOT:PSS was enhanced from 376 S cm-1 (prepared using free radical PSSA) to 422 S cm-1 (prepared using ATRP PSSA) when PSSA of Mn 35000 g mol-1 PSSA was used and was enhanced from 234 S cm-1 (prepared using free radical PSSA) to 325 S cm-1 (prepared using ATRP PSSA) when PSSA of Mn 55000 g mol-1 was used, by a factor of 15-30%.The greater the regularity of PSSA, the greater the packing density of PEDOT:PSS and consequently, the greater the charge carrier density. The improvement in packing density of PEDOT:PSS was confirmed by the improvement in crystallinity of PEDOT:PSS by X-ray diffraction (XRD) analysis. (Abstract) [Prior art document] [Patent documents] [Patent Document 1] JP 2004-115695 A [Patent Document 2] JP 2011-213823 A [Patent Document 3] WO2013 / 073259 Publication [Patent Document 4] JP 2021-147564 A [Patent Document 5] JP 2010-062059 A [Patent Document 6] WO2014 / 155422 Publication [Patent Document 7] Special Publication No. 2013-539806 [Patent Document 8] JP 2012-070013 A [Non-Patent Document 1] Laure V. Kayser et al., Influence of the molecular weight and size distribution of PSS on mixed ionic-electronic transport in PEDOT:PSS, Polymer Chemistry, 2022,13, 2764-2775 [Non-Patent Document 2] Jung Hyun Kim et al., Effect of molecular weight distribution of PSSA on electrical conductivity of PEDOT:PSS, RSC Advances, 2019, 9, 4028- Summary of the Invention [Means for solving the problem]

[0003] In a first aspect of the present invention, there is provided a composition comprising a sulfonic acid group-containing polyanion having a weight average molecular weight (Mw) of 180,000 to 500,000 and a polydispersity index (PDI) of 1.7 or less, and a cationic polythiophene that forms a complex with the polyanion.

[0004] In the above, the polyanion may be polystyrene sulfonate (PSS).

[0005] In the above, the cationic polythiophene may be polyethylenedioxythiophene (PEDOT).

[0006] In the above, the polyanion may be a homopolymer.

[0007] In the above, the polyanion may have a molecular weight dispersity of 1.25 to 1.45.

[0008] In the above, the weight average molecular weight (Mw) of the polyanion may be 200,000 to 320,000.

[0009] In the above, the viscosity change rate, defined as [viscosity after storage] / [viscosity before storage], after storage at 40°C for 14 days from the time of production and the viscosity before storage, may be 110% or less.

[0010] In a second aspect of the present invention, there is provided an antistatic agent comprising the above composition.

[0011] In a third aspect of the present invention, there is provided an antistatic film comprising a transparent substrate and an antistatic layer comprising the above-described composition.

[0012] In a fourth aspect of the present invention, there is provided a method for producing a polyanion, which comprises polymerizing a sulfonic acid group-containing monomer by living radical polymerization to produce a sulfonic acid group-containing polyanion having a weight average molecular weight (Mw) of 180,000 to 500,000 and a polydispersity index (PDI) of 1.7 or less.

[0013] In a fifth aspect of the present invention, there is provided a method for producing a composition containing a polyanion and a polythiophene, the method comprising: a polyanion production step in which a sulfonic acid group-containing monomer is polymerized by living radical polymerization to produce a sulfonic acid group-containing polyanion having a weight average molecular weight (Mw) of 180,000 to 500,000 and a polydispersity index (PDI) of 1.7 or less; and a polythiophene production step in which a cationic thiophene is polymerized in the polyanion to produce a cationic polythiophene that forms a complex with the polyanion.

[0014] In the above, living radical polymerization may be carried out using a reversible addition-fragmentation chain transfer (RAFT) agent.

[0015] In the above, the polyanion may be polystyrene sulfonate (PSS).

[0016] In the above, the cationic polythiophene may be polyethylenedioxythiophene (PEDOT).

[0017] In the above, the polyanion may be a homopolymer.

[0018] In the above, the polyanion may have a molecular weight dispersity of 1.25 to 1.45.

[0019] In the above, the weight average molecular weight (Mw) of the polyanion may be 200,000 to 320,000.

[0020] In the above, the viscosity change rate, defined as [viscosity after storage] / [viscosity before storage], after storing the composition at 40°C for 14 days from the time of production, and the viscosity before storage, may be 110% or less.

[0021] The above summary of the invention does not list all of the necessary features of the present invention, and subcombinations of these features may also constitute inventions. [Brief explanation of the drawings]

[0022] [Figure 1] An example of the antistatic film 10 according to this embodiment is shown. [Figure 2] An example of a flow of a method for producing the composition and antistatic film of the present embodiment will be described below. DETAILED DESCRIPTION OF THE INVENTION

[0023] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the scope of the invention according to the claims. Not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention. Furthermore, the embodiments will be described with reference to the drawings, and in the description of the drawings, the same reference numerals may be used to designate the same or similar parts, and redundant description may be omitted.

[0024] [Anti-static film] FIG. 1 shows an example of an antistatic film 10 according to this embodiment. The antistatic film 10 is a film with antistatic properties and is used for electrical devices that are prone to static buildup, such as displays and mobile phone terminals. The antistatic film 10 includes a transparent substrate 110 and an antistatic layer 120 provided on the transparent substrate. The antistatic film 10 may include other layers as necessary.

[0025] The transparent substrate 110 may be a transparent plate-like or film-like substrate made of glass, PET, etc. The antistatic film 10 may be formed of only the antistatic layer 120 without the transparent substrate 110.

[0026] The antistatic layer 120 contains an antistatic composition (hereinafter simply referred to as "composition"). The composition functions as an antistatic agent by containing a so-called conductive polymer to enhance conductivity. The thickness of the antistatic layer is preferably 0.001 to 10 μm, more preferably 0.01 to 5 μm. The thickness of the antistatic layer may be measured using a step gauge (e.g., DektakXY manufactured by Bruker) or an optical interferometer (e.g., F series manufactured by CYBERNET). Details of the composition are described below.

[0027] [Composition] The composition includes a sulfonic acid group-containing polyanion and a cationic polythiophene complexed with the polyanion.

[0028] The surface resistivity of the composition when applied to a PET substrate in a thickness of 0.1 μm may be 100,000 to 1,000,000 Ω / sq, which ensures sufficient conductivity, i.e., antistatic performance, when used as an antistatic agent.

[0029] [Polyanion] The sulfonic acid group-containing polyanion (hereinafter also simply referred to as "polyanion") may be an anionic polymer compound. The anionic polymer compound may be a polymer compound having an anionic group in the molecule that can cause chemical oxidative doping of the cationic polythiophene. The anionic group contains at least a sulfonic acid group. The anionic group may further contain one or more groups selected from a sulfate ester group, a phosphate ester group, a phosphate group, and a carboxyl group.

[0030] The polyanion may be a homopolymer. Alternatively, the polyanion may be a copolymer. For example, a copolymer of two or more types of anionic group-containing monomers is exemplified. Specific examples of such polyanions include polymers having sulfo groups, such as polystyrene sulfonic acid, polyvinyl sulfonic acid, polyallyl sulfonic acid, polyacrylic acid esters having sulfo groups, polymethacrylic acid esters having sulfo groups (e.g., poly(4-sulfobutyl methacrylate, polysulfoethyl methacrylate, polymethacryloyloxybenzenesulfonic acid), poly(2-acrylamido-2-methylpropanesulfonic acid), and polyisoprene sulfonic acid; and polymers having carboxy groups, such as polyvinyl carboxylic acid, polystyrene carboxylic acid, polyallyl carboxylic acid, polyacrylic acid, polymethacrylic acid, poly(2-acrylamido-2-methylpropanecarboxylic acid), and polyisoprene carboxylic acid. These may be homopolymers or copolymers of two or more types.

[0031] For example, the polyanion may be polystyrene sulfonate (PSS). The preparation of the polyanion is described below. The polyanion may have a terminal structure derived from the structure of the RAFT agent used in the polymerization, as described below.

[0032] The polyanion may have a weight-average molecular weight (Mw) of 180,000 to 500,000, preferably 200,000 to 400,000, and more preferably 200,000 to 320,000. The polyanion may have a polydispersity index (PDI) of 1.7 or less, preferably 1.5 or less, and more preferably 1.25 to 1.45. Here, PDI is the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn) (= Mw / Mn). By using a polyanion with a molecular weight in the relatively high molecular weight range and a low PDI as described above, the viscosity stability of the composition can be relatively improved while maintaining its transparency.

[0033] Here, viscosity stability refers to the property of viscosity not changing over time. For example, viscosity stability may be evaluated by the rate of change in viscosity when the composition is left for two weeks in a 40°C environment (i.e., an accelerated test). Viscosity stability may be evaluated by the rate of change in viscosity, defined as [viscosity after storage] / [viscosity before storage], after storing the composition at 40°C for 14 days from the time of production and the viscosity before storage. High viscosity stability, i.e., little change in viscosity, can improve the coatability of the composition, and ultimately improve the flatness and weather resistance of the antistatic layer 120.

[0034] Generally, lower viscosity is better in terms of workability, and can reduce raw material loss and mixing energy, etc. If viscosity is unstable, the burden of management and maintenance increases in case of high viscosity, but high viscosity stability can also reduce these burdens.

[0035] The viscosity of the polyanion at 25°C may be 30 mPa·s or less, preferably 20 mPa·s or less, and more preferably 1 to 15 mPa·s. This facilitates the operations during the production of the composition. It also contributes to lowering the viscosity of the final composition, making it easier to apply the composition.

[0036] The NV value (non-volatile content) of the polyanion may be 1 to 10 mass%, preferably 3 to 7 mass%, more preferably 4 to 6 mass%, for example, 5 mass%, and the viscosity of the polyanion may be measured after adjusting the NV value to such a value.

[0037] [Polythiophene] The cationic polythiophene that forms a complex with a polyanion may be a polythiophene that can form a complex with a polyanion and assume cationic properties. The cationic polythiophene may be a polythiophene-based conductive polymer. The cationic polythiophene may be produced by polymerizing a cationic thiophene in a polyanion.

[0038] The cationic polythiophene may be an unsubstituted polythiophene or a polythiophene substituted with one or more substituents, such as an alkyl group having 1 to 10 carbon atoms, an aryl group having 4 to 20 carbon atoms, a halogen group, an alcohol group, a hydroxyl group, an alkoxy group, a carboxyl group, a carbonyl group, an ether group, an alkyldioxy group, or an alkoxycarbonyl group.

[0039] For example, cationic polythiophenes include polythiophene, poly(3-methylthiophene), poly(3-ethylthiophene), poly(3-propylthiophene), poly(3-butylthiophene), poly(3-hexylthiophene), poly(3-heptylthiophene), poly(3-octylthiophene), poly(3-decylthiophene), poly(3-dodecylthiophene), poly(3-octadecylthiophene), poly(3-bromothiophene), poly(3-chlorothiophene), poly(3-iodothiophene), thiophene), poly(3-cyanothiophene), poly(3-phenylthiophene), poly(3,4-dimethylthiophene), poly(3,4-dibutylthiophene), poly(3-hydroxythiophene), poly(3-methoxythiophene), poly(3-ethoxythiophene), poly(3-butoxythiophene), poly(3-hexyloxythiophene), poly(3-heptyloxythiophene), poly(3-octyloxythiophene), poly(3-decyloxythiophene), poly(3-dodecyloxythiophene), thiophene), poly(3-octadecyloxythiophene), poly(3,4-dihydroxythiophene), poly(3,4-dimethoxythiophene), poly(3,4-diethoxythiophene), poly(3,4-dipropoxythiophene), poly(3,4-dibutoxythiophene), poly(3,4-dihexyloxythiophene), poly(3,4-diheptyloxythiophene), poly(3,4-dioctyloxythiophene), poly(3,4-didecyloxythiophene), poly(3,4-didodecyloxythiophene), The cationic polythiophene may be selected from poly(oxythiophene), poly(3,4-ethylenedioxythiophene), poly(3,4-propylenedioxythiophene), poly(3,4-butylenedioxythiophene), poly(3-methyl-4-methoxythiophene), poly(3-methyl-4-ethoxythiophene), poly(3-carboxythiophene), poly(3-methyl-4-carboxythiophene), poly(3-methyl-4-carboxyethylthiophene), and poly(3-methyl-4-carboxybutylthiophene). The cationic polythiophene may be, in particular, polyethylenedioxythiophene (PEDOT). When the polyanion is PSS, this forms PEDOT-PSS.

[0040] Examples of the combination of polyanion and polythiophene include the above-mentioned PEDOT-PSS and PEDOT-PVS, in which the cationic polythiophene is PEDOT and the polyanion is polyvinyl sulfonic acid (PVS).

[0041] The polymerization number and polydispersity index (PDI) of the cationic polythiophene may be comparable to those of the polyanion that forms the complex.

[0042] The composition may further contain a solvent. The solvent may be water, such as ion-exchanged water, or an organic solvent. For example, the organic solvent may be an alcohol-based solvent. The alcohol-based solvent may be an alcohol-based solvent consisting of or including one or more of isopropyl alcohol, methanol, and ethanol. As an example, the alcohol-based solvent may contain water and one or more alcohol components selected from isopropyl alcohol, methanol, and ethanol. The composition may be a solution in which the polyanion, polythiophene, etc. are at least partially dissolved in the solvent, or alternatively, may be a dispersion in which the polyanion, polythiophene, etc. are dispersed in the solvent.

[0043] The composition may contain a solvent in an amount that allows the concentrations of the polyanion and polythiophene to fall within a certain range. For example, the polyanion and polythiophene may be present in the composition at a weight ratio of 10% by weight or less, or even 5% by weight or less, with the lower limit being sufficient as long as the composition exhibits electrical conductivity. The concentrations of the polyanion and polythiophene in the composition are preferably in the range of 0.005 to 2% by weight. By maintaining the concentrations within the above range, sufficient electrical conductivity is exhibited and excellent viscosity stability is achieved. The viscosity of the composition at 25°C may be 5 to 500 mPa·s, preferably 5 to 200 mPa·s. The viscosity of the composition may be measured after adjusting the NV value to fall within the above range.

[0044] [Manufacturing method] Fig. 2 shows an example of a flow chart of a method for producing the composition and antistatic film of this embodiment. For example, the composition and antistatic film are produced by performing each of the processes of S100 to S300. Some of the processes of S100 to S300 may be omitted. In addition to S100 to S300, other processes may be performed as necessary. The composition and antistatic film may also be produced by a method other than that shown in Fig. 2.

[0045] First, in S100, a polyanion production step is carried out. In the polyanion production step, the above-mentioned polyanion is produced. In the anion production step, a polyanion having a weight average molecular weight (Mw) of 180,000 to 500,000, preferably 200,000 to 400,000, and more preferably 200,000 to 320,000, and a polydispersity index (PDI) of 1.7 or less, preferably 1.25 to 1.45, may be produced.

[0046] The polyanion may be produced by polymerizing an anionic group-containing polymerizable monomer. For example, the anionic group-containing polymerizable monomer may be radically polymerized in a solvent in the presence of an initiator and / or a catalyst to obtain the polyanion.

[0047] As an example of radical polymerization, living radical polymerization may be used, which can produce polyanions with a molecular weight dispersity of 1.7 or less, particularly about 1.25 to 1.45.

[0048] Examples of living radical polymerization include nitroxide-mediated polymerization (NMP), atom transfer polymerization (ATRP), reversible addition-fragmentation chain transfer polymerization (RAFT polymerization), organotellurium-mediated polymerization (TERP), iodine transfer polymerization (ITP), organometallic-mediated radical polymerization (OMRP), and reversible chain transfer catalyzed polymerization (RTCP). Among these, RAFT polymerization is particularly preferred.

[0049] NMP requires the preparation of special nitroxides that are difficult to obtain, and may require high-temperature processes, processes for removing high-boiling point solvents, and processes for replacing them with water. ATRP requires an organic solvent to dissolve the metal catalyst, and processes for removing the organic solvent and metal catalyst may also be necessary. TERP is sensitive to oxygen and may produce toxicity and odor from organotellurium. ITP requires difficult-to-obtain raw materials and is not compatible with styrene-based monomers.

[0050] On the other hand, RAFT polymerization is more suitable for producing polyanions than the above-mentioned NMP, ATRP, TERP, and ITP. Furthermore, while other methods such as ATRP leave halogen atoms at the polymer end, which can cause leakage current, RAFT polymerization eliminates this concern. Furthermore, while residual metals can adversely affect thermal stability, RAFT polymerization can achieve a metal-free structure compared to ATRP.

[0051] When RAFT polymerization is used, polymerization is initiated by mixing an anionic group-containing polymerizable monomer, an initiator, a reversible addition-fragmentation chain transfer agent (hereinafter also referred to as "RAFT agent"), and a solvent.

[0052] The anionic group-containing polymerizable monomer may be a monomer having a functional group polymerizable with an anionic group in the molecule. Examples of the anionic group-containing polymerizable monomer include vinyl sulfonic acid and its salts, allyl sulfonic acid and its salts, methallyl sulfonic acid and its salts, styrene sulfonic acid and its salts, methallyloxybenzene sulfonic acid and its salts, allyloxybenzene sulfonic acid and its salts, α-methylstyrene sulfonic acid and its salts, acrylamido-t-butyl sulfonic acid and its salts, 2-acrylamido-2-methylpropane sulfonic acid and its salts, cyclobutene-3-sulfonic acid and its salts, and the like. Acrylatesulfonic acid and its salts, 1,3-butadiene-1-sulfonic acid and its salts, 1-methyl-1,3-butadiene-2-sulfonic acid and its salts, 1-methyl-1,3-butadiene-4-sulfonic acid and its salts, ethyl acrylate sulfonic acid (CH2CH-COO-(CH2)2-SO3H) and its salts, propyl acrylate sulfonic acid (CH2CH-COO-(CH2)3-SO3H) and its salts, t-butyl acrylate sulfonic acid (CH2CH-COO-C(CH3)2CH2-SO 3H) and its salts, acrylic acid-n-butylsulfonic acid (CH2CH-COO-(CH2)4-SO3H) and its salts, allyl acid ethylsulfonic acid (CH2CHCH2-COO-(CH2)2-SO3H) and its salts, allyl acid-t-butylsulfonic acid (CH2CHCH2-COO-C(CH3)2CH2-SO3H) and its salts, 4-pentenoic acid ethylsulfonic acid (CH2CH(CH2)2-COO-(CH2)2-SO3H) and its salts, 4-pentenoic acid propylsulfonic acid (CH2CH( 4-pentenoic acid-n-butylsulfonic acid (CH2CH(CH2)2-COO-(CH2)4-SO3H) and its salts, 4-pentenoic acid-t-butylsulfonic acid (CH2CH(CH2)2-COO-C(CH3)2CH2-SO3H) and its salts, 4-pentenoic acid-phenylenesulfonic acid (CH2CH(CH2)2-COO-C6H4-SO3H) and its salts, 4-pentenoic acid naphthalenesulfonic acid (CH2CH(CH2)2-COO-C 10H8-SO3H) and its salts, methacrylic acid ethylsulfonic acid (CH2C(CH3)-COO-(CH2)2-SO3H) and its salts, methacrylic acid propylsulfonic acid (CH2C(CH3)-COO-(CH2)3-SO3H) and its salts, methacrylic acid-t-butylsulfonic acid (CH2C(CH3)-COO-C(CH3)2CH2-SO3H) and its salts, methacrylic acid-n-butylsulfonic acid (CH2C(CH3)-COO-(CH2)4-SO3H) and its salts, methacrylic acid phenylenesulfonic acid (CH2C(CH3)-COO-C6H4-SO3H) and its salts, methacrylic acid naphthalenesulfonic acid (CH2C(CH3)-COO-C 10 H8-SO3H) and salts thereof. Copolymers containing two or more of these may also be used. The salts may be sodium salts, potassium salts, or other salts that do not interfere with polymerization.

[0053] The initiator may be any known initiator suitable for RAFT polymerization. For example, 4,4'-azobis(4-cyanovaleric acid), sodium peroxodisulfate, 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine]n hydrate, 2,2'-azobis(isobutyronitrile), 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide], etc. may be used. It is preferable that the initiator does not contain a halogen atom.

[0054] The RAFT agent may have a general structure of YSC(=S)Z (Y and Z are any organic groups). For example, the RAFT agent may be selected from dithiobenzoate type (PhC(=S)SR), trithiocarbonate type (R'S(=S)SR), dithiocarbamate type (R'N(=S)SR), and dithiocarbonate type (R'O(=S)SR). Here, Ph is a phenyl group, and R and R' are organic groups such as hydrogen, unsubstituted or terminally carboxylated alkyl groups, and unsubstituted or terminally carboxylated aryl groups. In addition, the RAFT agent preferably does not contain halogen atoms.

[0055] For example, the RAFT agent may be selected from the following formulas 1-7: [Chemical formula 1] [ka] [Chemical formula 2] [ka] [Chemical formula 3] [ka] [Chemical formula 4] [ka] [Chemical formula 5] [ka] [Chemical formula 6] [ka] [Chemical formula 7] [ka]

[0056] In Chemical Formulas 1 to 7, n and m may each independently be selected from 1 to 20, and R may each independently be hydrogen or an alkyl group having 1 to 10 carbon atoms. For example, in Chemical Formulas 1 to 7, m and n may be 1, and R may be a methyl group. In particular, the use of Chemical Formulas 1, 5, and 6 is preferred from the viewpoints of reducing the molecular weight dispersity and saving material consumption.

[0057] The solvent may be water, in particular purified water such as distilled water or ion-exchanged water, and may further comprise an organic solvent such as an alcohol.

[0058] The content of the initiator may be 0.01 to 1 part by weight, preferably 0.05 to 0.5 parts by weight, per 100 parts by weight of the anionic group-containing polymerizable monomer. The content of the RAFT agent may be 0.1 to 3 parts by weight, preferably 0.2 to 1 part by weight, per 100 parts by weight of the anionic group-containing polymerizable monomer. The content of the solvent may be 100 to 2,000 parts by weight, preferably 500 to 1,000 parts by weight, per 100 parts by weight of the anionic group-containing polymerizable monomer.

[0059] By adjusting the content of each component (especially the RAFT agent) within the above range, the weight-average molecular weight (Mw) can be controlled within an appropriate range. For example, increasing the amount of RAFT agent can decrease the molecular weight, and decreasing the amount of RAFT agent can increase the molecular weight.

[0060] In RAFT polymerization, the polyanion has a terminal structure derived from the RAFT agent. For example, if the RAFT agent has the general structure YSC(=S)Z, at least a portion of the polyanion may have an organic group Y at one end and an organic group Z at the other end.

[0061] For example, the termini of the polyanion may be Ph, SR, PhC, and R groups derived from dithiobenzoate type (PhC(=S)SR), R', SR, SR', and R groups derived from trithiocarbonate type (R'S(=S)SR), R', SR, NR', and R groups derived from dithiocarbamate type (R'N(=S)SR), or R', SR, OR', and R groups derived from dithiocarbonate type (R'O(=S)SR), where Ph is a phenyl group and R and R' are organic groups such as hydrogen, unsubstituted or terminally substituted alkyl groups, and unsubstituted or terminally substituted carboxyl aryl groups.

[0062] For example, the polyanion may have a phenyl group and a terminal group selected from the following chemical formulas 8 to 23. For example, the polyanion may have a phenyl group and a terminal group represented by chemical formulas 8 to 9. For example, the polyanion may have a terminal group represented by chemical formulas 10 to 13. For example, the polyanion may have a terminal group represented by chemical formulas 10 to 11 and chemical formulas 14 to 15. For example, the polyanion may have a terminal group represented by chemical formulas 16 to 19. For example, the polyanion may have a terminal group represented by chemical formulas 16 to 17 and chemical formulas 20 to 21. For example, the polyanion may have a terminal group represented by chemical formulas 16 to 17 and chemical formulas 22 to 23. For example, the polyanion may have a terminal group represented by chemical formulas 16 to 17 and chemical formulas 24 to 25.

[0063] [Chemical formula 8] [ka] [Chemical formula 9] [ka] [Chemical formula 10] [ka] (i.e., alkyl groups with carbon length m+2) [Chemical formula 11] [ka] [Chemical formula 12] [ka] [Chemical formula 13] [ka] [Chemical formula 14] [ka] [Chemical formula 15] [ka] [Chemical formula 16] [ka] [Chemical formula 17] [ka] [Chemical formula 18] [ka] [Chemical formula 19] [ka] [Chemical formula 20] [ka] [Chemical formula 21] [ka] [Chemical formula 22] [ka] [Chemical formula 23] [ka] [Chemical formula 24] [ka] [Chemical formula 25] [ka]

[0064] In Chemical Formulae 8 to 25, n and m may each independently be selected from 1 to 20, and R may each independently be hydrogen or an alkyl group having 1 to 10 carbon atoms.

[0065] The polymerization temperature in the polymerization reaction may be 10 to 150°C, or may be 30 to 100°C. The polymerization time may be 30 minutes to 48 hours, or may be 4 to 12 hours. Furthermore, various post-treatments may be carried out during and / or after the polymerization reaction, as needed. For example, pressure manipulation (e.g., reducing pressure and / or restoring pressure), temperature adjustment (e.g., heating and / or cooling), and / or ion exchange treatment (e.g., cation ion exchange resin treatment and / or anion ion exchange resin treatment) may be carried out as post-treatments.

[0066] Next, in S200, a polythiophene formation step is carried out. In the polythiophene formation step, a cationic thiophene may be polymerized in a solution containing the polyanion formed in S100 to form a cationic polythiophene that forms a complex with the polyanion.

[0067] For example, a cationic polythiophene may be produced by mixing and stirring a polyanion, a cationic thiophene, an oxidizing agent, a catalyst, and a solvent at a constant temperature (e.g., 10 to 50° C.), and if necessary, an acid solution and / or at least one other additive may be added to the reaction system to promote chemical oxidative polymerization.

[0068] The cationic thiophene may be, for example, an unsubstituted thiophene or a thiophene substituted with one or more substituents. The substituent may be, for example, an alkyl group having 1 to 10 carbon atoms, an aryl group having 4 to 20 carbon atoms, a halogen group, an alcohol group, a hydroxyl group, an alkoxy group, a carboxyl group, a carbonyl group, an ether group, an alkyldioxy group, or an alkoxycarbonyl group.

[0069] Examples of cationic thiophenes include thiophene, 3-methylthiophene, 3-ethylthiophene, 3-propylthiophene, 3-butylthiophene, 3-hexylthiophene, 3-heptylthiophene, 3-octylthiophene, 3-decylthiophene, 3-dodecylthiophene, 3-octadecylthiophene, 3-bromothiophene, 3-chlorothiophene, 3-iodothiophene, 3-cyanothiophene, 3-phenylthiophene, 3,4-dimethylthiophene, 3,4-dibutylthiophene, 3-hydroxythiophene, 3-methoxythiophene, 3-ethoxythiophene, 3-butoxythiophene, 3-hexyloxythiophene, 3-heptyloxythiophene, 3-octyloxythiophene, 3-decyloxythiophene, 3-dodecyloxythiophene, and 3-octadecyloxythiophene. The cationic polythiophene may be one or more of thiophene, 3,4-dihydroxythiophene, 3,4-dimethoxythiophene, 3,4-diethoxythiophene, 3,4-dipropoxythiophene, 3,4-dibutoxythiophene, 3,4-dihexyloxythiophene, 3,4-diheptyloxythiophene, 3,4-dioctyloxythiophene, 3,4-didecyloxythiophene, 3,4-didodecyloxythiophene, 3,4-ethylenedioxythiophene, 3,4-propylenedioxythiophene, 3,4-butylenedioxythiophene, 3-methyl-4-methoxythiophene, 3-methyl-4-ethoxythiophene, 3-carboxythiophene, 3-methyl-4-carboxythiophene, 3-methyl-4-carboxyethylthiophene, and 3-methyl-4-carboxybutylthiophene. The cationic polythiophene may in particular be ethylenedioxythiophene (EDOT).

[0070] The solvent may be water, in particular purified water such as distilled water or ion-exchanged water, or may comprise an organic solvent.

[0071] The oxidizing agent may be sodium persulfate or ammonium persulfate. The catalyst may be an iron catalyst, such as Fe2(SO4)3, FeCl2, FeCl3, or hydrates thereof.

[0072] The content of the cationic thiophene may be 0.1 to 10 parts by weight relative to 100 parts by weight of the polyanion. The content of the oxidizing agent may be 10 to 100 parts by weight relative to 100 parts by weight of the polyanion. The content of the catalyst may be 10 to 100 parts by weight relative to 100 parts by weight of the polyanion. The content of the solvent may be 50 to 1000 parts by weight relative to 100 parts by weight of the polyanion.

[0073] If necessary, the polymerization reaction product may be subjected to post-treatment, such as purification, drying, addition of a solvent such as water, ion exchange treatment (e.g., treatment with a cation ion exchange resin and / or treatment with an anion ion exchange resin), filtration treatment such as ultrafiltration, acid treatment, and / or microparticulation treatment using a homogenizer such as a high-pressure homogenizer or an ultrasonic homogenizer.

[0074] The purified polymerization product may be mixed with a solvent such as water to recover a composition containing a polyanion and a cationic polythiophene that forms a complex with the polyanion. If necessary, an additive (e.g., a conductive agent) may be separately added to the composition.

[0075] The composition produced in this manner can have a sufficiently low viscosity change rate when the NV value is kept constant. For example, when the NV value is set to 0.1 to 5 mass % (for example, 1.63 mass %), the viscosity change rate of the composition can be 110% or less, preferably 105% or less, and more preferably 100% or less.

[0076] Next, in S300, the composition obtained in S200 is coated on a substrate and dried to produce an antistatic film. The substrate may be a transparent resin film such as a PET substrate or a glass film. When the composition (e.g., a composition with an NV value of 1.63% by mass) is coated on a PET substrate to a dry film thickness of 0.1 μm, the surface resistivity can be 100,000 to 1,000,000 Ω / sq. The NV value (non-volatile content) may be measured using an Agilent Mark 3. Any coating method may be used, including spin coating, bar coating, immersion, comma coating, spray coating, roll coating, screen printing, flexographic printing, gravure printing, and inkjet printing. The composition can be dried by heating using a hot air circulating oven or a hot plate. The drying time may be 30 seconds to 30 minutes, and the drying temperature may be room temperature, or 50 to 200°C if heat drying is used.

[0077] According to the flow of the production method of this embodiment, a composition can be produced that contains a sulfonic acid group-containing polyanion having a weight average molecular weight (Mw) of 180,000 to 500,000 and a polydispersity index (PDI) of 1.7 or less, and a cationic polythiophene that forms a complex with the polyanion, thereby providing a composition that maintains both transparency and viscosity stability.

[0078] [Example] Examples will be shown below, but the present embodiment is not limited to these examples.

[0079] Example 1 (Generation of Polyanion 1) 45.75 g of sodium styrenesulfonate and 300 g of ion-exchanged water were mixed and stirred in a separable beaker. 0.0215 g of 4,4'-azobis(4-cyanovaleric acid), 0.1030 g of 2-[[[(2-carboxylethyl)thio]carbonothioyl]thio]-2-methylpropanoic acid (Rtt-13, manufactured by Ouchi Shinko Chemical Co., Ltd.), and 19.76 g of ion-exchanged water were mixed and stirred in a dissolution vessel, and then added to the separable beaker.

[0080] Thereafter, while continuing to stir the solution in the separable beaker using a balloon, the pressure was reduced and then restored with nitrogen, which was repeated three times.

[0081] The solution in the separable beaker was then heated to 70°C and stirred while maintaining the temperature. After maintaining the temperature for 8 hours, the solution was cooled to room temperature. Monomers and other components were removed using a cation ion exchange resin and an anion ion exchange resin, and the solution was then filtered to obtain polystyrene sulfonate (PSS) obtained by RAFT polymerization.

[0082] The NV value of PSS was adjusted with ion-exchanged water and then measured using an Agilent Mark 3 at 100-120°C and dried on a filter paper for 15 minutes.

[0083] The weight-average molecular weight (Mw) of PSS measured using a Shimadzu Nexera-GPC was 201,000, the number-average molecular weight was 140,000, and the PDI was 1.43. The GPC conditions were: 50 mM NaNO3 eluent, flow rate 1.0 mL / min, two Shodex SB-806M HQ columns, and a column oven temperature of 40°C. The sample was diluted with the eluent to achieve an NV value of 0.1% by mass. The injection volume was 100 μL, and the calibration curve was a cubic equation, converted to pullulan (Shodex P-82, 8 types).

[0084] The viscosity at 25°C of PSS adjusted to an NV value of 5% by mass, measured using an A&D SV-10, was 8.0 mPa s. The APHA (Hazen color number) of PSS with an NV value of 2.0% by mass was 20. APHA measurements were performed in accordance with JIS K0071.

[0085] (Polythiophene production) 360 g of PSS and 588 g of ion-exchanged water were mixed in a separable beaker. While continuing to stir the solution in the separable beaker using a nitrogen line, the pressure was reduced and then restored with nitrogen, which was repeated twice.

[0086] 6.0 g of ethylenedioxythiophene (EDOT), 123.6 g of a 2.91% by mass Fe2(SO4)3 aqueous solution, and 120 g of ion-exchanged water were mixed in a separable beaker. 132.2 g of a 9.91% by mass sodium persulfate aqueous solution was then gradually added dropwise and mixed. The mixture was then allowed to react for 4 hours while maintaining the temperature at 30°C.

[0087] The mixture was purified using cation and anion ion exchange resins and filtered. Purified water was added to achieve an NV value of 1.7% by mass, and the mixture was then processed five times at 150 MP using a high-pressure homogenizer to refine the mixture. The mixture was then purified again using cation and anion ion exchange resins and filtered. This yielded PEDOT-PSS.

[0088] The NV value of PEDOT-PSS was adjusted to 1.63% by mass with ion-exchanged water, and various measurements were performed. The absorbance at 600 nm was 0.74. The viscosity at 25°C, measured using an A&D SV-10, was 31 mPa·s. After storing the PEDOT-PSS at 40°C for two weeks, the viscosity at 25°C, measured using an A&D SV-10, was 31 mPa·s. The viscosity change rate was 100% (i.e., no substantial change).

[0089] The NV value of PEDOT-PSS (NV value 1.63% by mass) was adjusted to 0.815% by mass with methanol, and PEDOT-PSS (NV value 0.815% by mass) was coated onto a 100 μm-thick PET film (T680-E100, manufactured by Mitsubishi Chemical) to a dry film thickness of 0.1 μm using a #8 bar coater (#8-BC). The laminated film was then dried at 105°C for 1 minute to obtain a laminated film. The total light transmittance of the resulting laminated film measured with a haze meter (Nippon Denshoku NDH-5000, blank = air) was 88.08, the haze value was 1.50, and the surface resistance measured with a URS probe (Hiresta, manufactured by Mitsubishi Chemical Analytech) was 10 6.9The measured value was Ω / sq. The laminated film was found to be an antistatic film. The total light transmittance measured for the PET film (T680-E100 manufactured by Mitsubishi Chemical) alone was 92.26, and the haze was 1.56. (Dispersion stability) The dispersion stability of PEDOT-PSS was measured. When PEDOT-PSS or similar is diluted in an alcohol-based solvent, granular precipitates (hereinafter referred to as "particles") may form, or a gel-like (or pudding-like) state (hereinafter referred to as "gel" may occur). The formation of particles or gels may make it difficult to supply with a pump or may cause filter clogging, which may be undesirable depending on the application method. The specific method for evaluating dispersion stability is as follows: 2.5 g of PEDOT-PSS (NV value 1.63% by mass) is mixed with 5 g of the solvent to be measured (e.g., an alcohol-based solvent) and stirred for approximately 1 hour. The NV value of the resulting composition is 0.54% by mass, and it contains 66.67% by mass of the solvent to be measured and 32.79% by mass of water. The solution is then left to stand for 24 hours, and the appearance of the solution is observed to confirm the presence of lumps and / or gels. The dispersion stability test showed that neither lumps nor gels were formed in methanol, ethanol, or isopropanol.

[0090] Example 2 (Generation of polyanion 2) PSS was produced in the same manner as in Example 1 (Polyanion 1), except that 0.0122 g of 4,4'-azobis(4-cyanovaleric acid) and 0.0586 g of 2-[[[(2-carboxylethyl)thio]carbonothioyl]thio]-2-methylpropanoic acid (Rtt-13, manufactured by Ouchi Shinko Chemical Co., Ltd.) were used, and 138 g of ion-exchanged water was mixed into the separable beaker instead of 300 g of ion-exchanged water.

[0091] The weight-average molecular weight (Mw) of the PSS was 311,000, the number-average molecular weight was 218,000, and the PDI was 1.43. The viscosity at 25°C was 14.5 mPa·s. The APHA (Hazen color index) was 5.

[0092] Thereafter, PEDOT-PSS was produced in the same manner as in Example 1, and measurements were carried out in the same manner as in Example 1. The absorbance at a wavelength of 600 nm was 0.73. The viscosity at 25°C was 46 mPa·s. The viscosity at 25°C after storage at 40°C for 2 weeks was 41 mPa·s. The viscosity change rate was 90%. The total light transmittance of the antistatic film after coating with the PET film was 88.48, the haze value was 1.55, and the surface resistance measured with a URS probe (Hiresta, manufactured by Mitsubishi Chemical Analytech) was 10 6.9 The dispersion stability test showed that neither granules nor gels were formed in methanol, ethanol, or isopropanol.

[0093] (Comparative Example 1) (Generation of polyanion B1) PSS was produced in the same manner as in Example 1 (Polyanion 1), except that 0.0472 g of 4,4′-azobis(4-cyanovaleric acid) and 0.2265 g of 2-[[[(2-carboxylethyl)thio]carbonothioyl]thio]-2-methylpropanoic acid (Rtt-13, manufactured by Ouchi Shinko Chemical Co., Ltd.) were used.

[0094] The weight-average molecular weight (Mw) of the PSS was 91,000, the number-average molecular weight was 69,000, and the PDI was 1.33. The viscosity at 25°C was 3.1 mPa·s. The APHA (Hazen color index) was 50.

[0095] Thereafter, PEDOT-PSS was produced in the same manner as in Example 1, and measurements were carried out in the same manner as in Example 1. The absorbance at 600 nm was 0.75. The viscosity at 25°C was 14 mPa·s. The viscosity at 25°C after 2 weeks of storage at 40°C was 18 mPa·s. The viscosity change rate was 135%. After coating the PET film, the total light transmittance was 88.07, the haze value was 1.53, and the surface resistance measured with a URS probe (Hiresta, manufactured by Mitsubishi Chemical Analytech) was 10 6.7 It was Ω / sq.

[0096] (Comparative Example 2) (Generation of polyanion B2) 21.8 g of sodium persulfate and 58.2 g of ion-exchanged water were mixed and stirred in a beaker to obtain an aqueous sodium persulfate solution. Next, 100.0 g of sodium styrene sulfonate and 1300.0 g of ion-exchanged water were mixed and stirred in a separable flask. Subsequently, while continuing to stir the solution in the separable beaker, the pressure was reduced and then restored with nitrogen three times. The solution in the separable beaker was then heated to 80°C. After reaching 80°C, the aqueous sodium persulfate solution was added over a period of two hours. After adding the aqueous sodium persulfate solution, the container containing the aqueous sodium persulfate solution was rinsed with 20.0 g of ion-exchanged water, which was then added all at once to the separable beaker. Stirring was continued for two hours. The liquid in the separable beaker was then cooled to room temperature. Monomers and other substances were removed using a cation ion exchange resin and an anion ion exchange resin, and further filtration was performed to obtain polystyrene sulfonate (PSS) by free radical polymerization (FR).

[0097] The weight-average molecular weight (Mw) of the PSS was 51,000, the number-average molecular weight was 29,000, and the PDI was 1.75. The viscosity at 25°C was 0.7 mPa·s. The APHA (Hazen color index) was 120.

[0098] Thereafter, PEDOT-PSS was produced in the same manner as in Example 1, and measurements were carried out in the same manner as in Example 1. The absorbance at 600 nm was 1.04. The viscosity at 25°C was 52 mPa·s. The viscosity at 25°C after 2 weeks of storage at 40°C was 208 mPa·s. The viscosity change rate was 398%. After coating the PET film, the total light transmittance was 86.8, the haze value was 1.63, and the surface resistance measured with a URS probe (Hiresta, manufactured by Mitsubishi Chemical Analytech) was 10 5.1 It was Ω / sq.

[0099] (Comparative Example 3) (Generation of polyanion B3) PSS was produced using free radical polymerization as in Comparative Example 1 (Polyanion B1), except that the degree of polymerization was changed.

[0100] The weight-average molecular weight (Mw) of the PSS was 97,000, the number-average molecular weight was 49,000, and the PDI was 1.98. The viscosity at 25°C was 1.4 mPa·s. The APHA (Hazen color index) was 50.

[0101] Thereafter, PEDOT-PSS was produced in the same manner as in Example 1, and measurements were carried out in the same manner as in Example 1. The absorbance at a wavelength of 600 nm was 0.92. The viscosity at 25°C was 30 mPa·s. The viscosity at 25°C after storage at 40°C for 2 weeks was 59 mPa·s. The viscosity change rate was 199%. After coating on the PET film, the total light transmittance was 87.5, the haze value was 1.51, and the surface resistance measured with a URS probe (Hiresta, manufactured by Mitsubishi Chemical Analytech) was 10 5.6 It was Ω / sq.

[0102] Comparative Example 4 (Generation of polyanion B4) PSS was produced using free radical polymerization as in Comparative Example 1 (Polyanion B1), except that the degree of polymerization was changed.

[0103] The weight-average molecular weight (Mw) of the PSS was 214,000, the number-average molecular weight was 92,000, and the PDI was 2.32. The viscosity at 25°C was 4.3 mPa·s. The APHA (Hazen color index) was 40.

[0104] Thereafter, PEDOT-PSS was produced in the same manner as in Example 1, and measurements were carried out in the same manner as in Example 1. The absorbance at 600 nm was 0.80. The viscosity at 25°C was 29 mPa·s. The viscosity at 25°C after 2 weeks of storage at 40°C was 37 mPa·s. The viscosity change rate was 129%. After coating the PET film, the total light transmittance was 88.26, the haze value was 1.47, and the surface resistance measured with a URS probe (Hiresta, manufactured by Mitsubishi Chemical Analytech) was 10 5.6 The dispersion stability test showed that gels were formed in all of methanol, ethanol, and isopropanol.

[0105] (Comparative Example 5) (Generation of polyanion B5) PSS was produced using free radical polymerization as in Comparative Example 1 (Polyanion B1), except that the degree of polymerization was changed.

[0106] The weight-average molecular weight (Mw) of the PSS was 302,000, the number-average molecular weight was 123,000, and the PDI was 2.45. The viscosity at 25°C was 7.6 mPa·s. The APHA (Hazen color index) was 40.

[0107] Thereafter, PEDOT-PSS was produced in the same manner as in Example 1, and measurements were carried out in the same manner as in Example 1. The absorbance at 600 nm was 0.78. The viscosity at 25°C was 36 mPa·s. The viscosity at 25°C after 2 weeks of storage at 40°C was 39 mPa·s. The viscosity change rate was 106%. After coating the PET film, the total light transmittance was 88.15, the haze value was 1.47, and the surface resistance measured with a URS probe (Hiresta, manufactured by Mitsubishi Chemical Analytech) was 10 6.5 The dispersion stability test showed that gels were formed in all of methanol, ethanol, and isopropanol.

[0108] In this way, in the examples, polyanions with a weight-average molecular weight (Mw) of 180,000 to 500,000 and a polydispersity index (PDI) of 1.7 or less were synthesized. According to the examples, the viscosity change rate was kept low at around 100% while maintaining high transparency.

[0109] On the other hand, in Comparative Example 1, the weight average molecular weight (Mw) was less than 180,000. As a result, the viscosity change rate was higher than in the Examples. In Comparative Examples 2 to 5, the molecular weight dispersity index (PDI) exceeded 1.7, resulting in a broadened molecular weight distribution. As a result, the viscosity change rate in Comparative Examples 2 to 5 was higher than in Examples with similar molecular weights. Thus, in the Examples, the viscosity change rate could be kept low at 110% or less while maintaining transparency, whereas in the Comparative Examples, these properties could not be maintained.

[0110] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. Furthermore, the details described for a particular embodiment can be applied to other embodiments to the extent that they are not technically inconsistent. Furthermore, each component may have the same features as other components with the same name but different reference numerals. It is apparent from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

[0111] It should be noted that the execution order of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not specifically stated as "before," "prior to," etc., and that the processes can be performed in any order unless the output of a previous process is used in a subsequent process. Even if the operational flow in the claims, specifications, and drawings is described using "first," "next," etc. for convenience, this does not mean that the processes must be performed in this order. [Explanation of symbols]

[0112] 10 Antistatic film 110 Base material 120 Antistatic layer

Claims

1. A composition comprising a sulfonic acid group-containing polyanion having a weight average molecular weight (Mw) of 180,000 to 500,000 and a polydispersity index (PDI) of 1.7 or less, and a cationic polythiophene that forms a complex with the polyanion.

2. The polyanion is polystyrene sulfonate (PSS). The composition of claim 1.

3. The cationic polythiophene is polyethylenedioxythiophene (PEDOT). The composition of claim 2.

4. The polyanion is a homopolymer. The composition of claim 1.

5. The molecular weight dispersity of the polyanion is 1.25 to 1.

45. The composition of claim 1.

6. The weight average molecular weight (Mw) of the polyanion is 200,000 to 320,000. The composition of claim 1.

7. The viscosity change rate, defined as [viscosity after storage] / [viscosity before storage], after storage at 40°C for 14 days from the time of production is 110% or less, The composition of claim 1.

8. An antistatic agent comprising the composition of any one of claims 1 to 7.

9. A transparent substrate; an antistatic layer provided on the transparent substrate, the antistatic layer comprising the composition of any one of claims 1 to 7; Including an anti-static film.

10. a sulfonic acid group-containing monomer is polymerized by living radical polymerization to produce a sulfonic acid group-containing polyanion having a weight average molecular weight (Mw) of 180,000 to 500,000 and a polydispersity index (PDI) of 1.7 or less; Method for producing polyanions.

11. a polyanion generation step in which a sulfonic acid group-containing monomer is polymerized by living radical polymerization to generate a sulfonic acid group-containing polyanion having a weight average molecular weight (Mw) of 180,000 to 500,000 and a polydispersity index (PDI) of 1.7 or less; a polythiophene-forming step of polymerizing a cationic thiophene in the polyanion to form a cationic polythiophene that forms a complex with the polyanion; 1. A method for producing a composition comprising a polyanion and a polythiophene, comprising:

12. carrying out the living radical polymerization using a reversible addition-fragmentation chain transfer (RAFT) agent; The method according to claim 10 or 11.

13. The polyanion is polystyrene sulfonate (PSS). The method according to claim 10 or 11.

14. The cationic polythiophene is polyethylenedioxythiophene (PEDOT). The method of claim 11.

15. The polyanion is a homopolymer. The method according to claim 10 or 11.

16. The molecular weight dispersity of the polyanion is 1.25 to 1.

45. The method according to claim 10 or 11.

17. The weight average molecular weight (Mw) of the polyanion is 200,000 to 320,000. The method according to claim 10 or 11.

18. the viscosity change rate after storage of the composition at 40°C for 14 days from the production date, which is defined as [viscosity after storage] / [viscosity before storage], is 110% or less; The method of claim 11.

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