KR101000496B1 - Method of manufacturing nanoparticles of poly3,4-ethylenedioxythiophene - Google Patents

Abstract

The present invention relates to a method for preparing poly (3,4-ethylenedioxythiophene) nanopowders having solubility in various solvents, wherein the monomer is 3,4 in the presence of a dopant such as di (2-ethylhexyl) sulfosuccinic acid. When the ethylene dioxythiophene is polymerized with an oxidizing agent such as ammonium persulfate, a steric stabilizer is added.

The poly (3,4-ethylenedioxythiophene) nanopowder prepared according to the present invention has excellent solubility in various organic solvents, and does not occur quickly due to gelation even when dissolved or dispersed at high concentration in an organic solvent. Excellent solution stability and good electrical conductivity.

Soluble, poly (3,4-ethylenedioxythiophene), nanopowder, dopant, steric stabilizer

Description

Method for manufacturing soluble poly (3,4-ethylenedioxythiophene) nanopowder {Method of manufacturing nanoparticles of poly (3,4-ethylenedioxythiophene)}

The present invention is soluble in a variety of organic solvents, even when dissolved or dispersed in a high concentration in organic solvents (Gel) does not occur quickly because of excellent storage stability, excellent electrical conductivity and transparency to the soluble poly (3, useful as a conductive polymer) 4-ethylenedioxythiophene) nano powder.

The conductive polymers known up to now have the disadvantage that physical properties such as mechanical properties and processability are inferior in comparison with conventional functional polymers, while controlling the electrical properties from the insulator to the semiconductor and the conductor by doping.

Most conductive polymers have a disadvantage in that transparency is greatly reduced because they absorb light in the visible region. Therefore, these conductive polymers are limited in their use in fields where high transparency is not required. Recently, however, Bayer of Germany introduced a new structure of monomer called 3,4-ethylenedioxythiophene (hereinafter referred to as "EDOT"). It is a monomer having a structure having an ethylenedioxy group in the form of a ring in the basic structure of a thiophene, and when the 3,4-ethylenedioxythiophene monomer is electrochemically or chemically polymerized, Oxythiophene) (hereinafter referred to as "PEDOT"). [Electrodonating effect of ethylenedioxy group has lower optical bandgap (1.6 ~ 1.7eV) than conventional thiophene]. This poly (3,4-ethylenedioxythiophene) has a higher transparency than conventional conductive polymers. In the early days of Bayer, poly (3,4-ethylenedioxythiophene) was prepared in an alcohol solution by reacting a monomer 3,4-ethylenedioxythiophene with an oxidizing agent in an alcohol solvent.

However, PEDOT in the alcohol solution state has a problem of poor electrical conductivity, coating property, dispersibility, and the like.

As another conventional technology for solving such a problem, US Patent No. 5,300,573 uses polystyrene sulfonate (PSS) as a dopant, and polymerizes EDOT in an aqueous solution to prepare PEDOT in an aqueous solution, thereby providing electrical conductivity and thermal stability. And the improvement in coating property, dispersibility, and the like. In addition, a method of preparing PEDOT having an additional advantage in terms of strength and hardness through addition of silicate to an alcohol solution of EDOT and heat treatment after coating for various applications is also proposed.

However, the PEDOT in the form of an aqueous dispersion has an environmentally friendly advantage, but there are difficulties in storage, and difficult to process in various forms, so that it is difficult to apply to various industrial uses.

As another conventional technique, US Patent No. 7,279,534 discloses a method for preparing a conductive polymer having a water solubility and a solubility in an organic solvent by copolymerizing (heteroaromatic) polymer [Poly (heteroaromatic)] and polyethylene glycol in the presence of a dopant and an oxidizing agent. Is proposing.

However, the manufacturing method of the water / oil-based conductive polymer as described above has a problem in that the synthesis method is complicated, takes a long time to synthesize, has solubility only in a limited organic solvent, and has a low solubility of less than 1% by weight.

As another conventional technique for solving such a problem, Korean Patent No. 10-0374719 discloses a 3,4-ethylenedioxycylate as a monomer in a polymerization solvent in the presence of a dopant such as di (2-ethylhexyl) sulfosuccinic acid. A method for producing PEDOT having a solubility in an organic solvent by polymerizing offentic (EDOT) using an oxidizing agent has been proposed.

The method of preparing the organic solvent-soluble PEDOT is easy to synthesize and has advantages in being applicable to various industrial fields. However, when dissolving or dispersing at an organic solvent concentration of 5% by weight or more, the gelation phenomenon occurs severely within a few days. There was a problem that the storage stability of significantly decreased.

An object of the present invention is to solve the conventional problems as described above, is easy to synthesize, has excellent solubility in a variety of organic solvents can be applied to a variety of industrial fields, in particular an organic solvent in a concentration of more than 5% by weight The present invention is to provide a method for preparing soluble PEDOT nanopowder having excellent storage stability since no gelation reaction occurs for 6 months or more even when dissolved or dispersed.

In order to solve the above problems, the present invention is to polymerize 3,4-ethylenedioxythiophene (EDOT), which is a monomer, in a polymerization solvent in the presence of a dopant such as di (2-ethylhexyl) sulfosuccinic acid by using an oxidizing agent. When preparing PEDOT having solubility in a solvent, the particle size of the PEDOT powder prepared by further adding a steric stabilizer to the polymerization solvent prior to the polymerization reaction is reduced to nano size and the particle distribution is uniform.

In the present invention, since the PEDOT nanopowder prepared as described above has a small size, the specific surface area is increased, so that the solubility in various organic solvents can be further improved, and the organic solvent can be dispersed in an organic solvent more than 10% by weight. Significantly improves stability and conductivity.

The present invention facilitates the synthesis of PEDOT nanopowder, PEDOT nanopowder prepared by the present invention has good solubility in various organic solvents can be widely used in various industrial fields, it is possible to dissolve or disperse high concentration in organic solvents In particular, there is an effect excellent in solution stability and electrical conductivity.

Therefore, the PEDOT nanopowder manufactured by the present invention is antistatic, electromagnetic wave absorber, electromagnetic wave shielding paint and coating material, battery, polymer electrolyte for capacitor, IR absorber, photochemical cell, printed circuit board (PCB) Conductive coating, electrochromic device (ECD), corrosion protection, resistive heating, cable shielding, microwave absorber, temperature, shock, chemical sensor, light emitting diode device (LED), It is useful as a material for manufacturing a transparent conductive electrode, a field effect transistor (FET), a solar cell and a conductive ink for a display, a conductive paste, and the like.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

In the method for preparing soluble PEDOT nanopowder according to the present invention, a 3,4-ethylenedioxythiophene monomer of the general formula (I), a dopant of the general formula (II) and an oxidizing agent are added to a reaction vessel containing a polymerization solvent. When preparing a soluble poly (3,4-ethylenedioxythiophene) powder by polymerization, the steric stabilizer is further added to the reaction vessel before the polymerization reaction.

The compound of the general formula (I) is 3,4-ethylenedioxythiophene fused with ethylenedioxine 1,2 or carbon and 3,4 carbon of thiophene.

The compound represented by the general formula (II) is di (2-ethylhexyl) sulfosuccinic acid (or sodium salt of di (2-ethylhexyl) sulfosuccinic acid]. Wherein R, R 'is a 2-ethylhexyl group and X is a sulfonic acid or sodium salt of sulfonic acid.

[In Formula (II), R and R 'are 2-ethylhexyl, 2-20 carbons, isoalkyl, alkoxy, alkoxyalkyl. ), Alkylsulfonyl, alkoxysulfonyl, alkylsilane or alkoxysilane, X is SO ₃ H, SO ₃ Na, sulfonate, carboxylate ), Phosphate, sulfate, cyanate, and silicate.]

As a specific example of the dopant of the said general formula (II), the salt of a C2-C20 dialkyl sulfosuccinic acid, a C2-C20 dialkyl sulfosuccinic acid, an aromatic sulfonic acid, an aromatic sulfonic acid salt, C1-C10 Or a mixture selected from the group consisting of an alkyl sulfate having an alkyl group and a dialkyl sulfate having an alkyl group having 1 to 10 carbon atoms.

A preferred example of the dialkylsulfosuccinic acid having 2 to 20 carbon atoms is di (2-ethylhexyl) sulfosuccinic acid, and a preferred example of the dialkylsulfosuccinic acid salt having 2 to 20 carbon atoms is di (2-ethylhexyl) sulfosuccinic acid sodium salt. .

As the steric stabilizer, polyvinyl alcohol, polyethylene oxide, poly (N-vinylpyrrolidone), poly (styrenesulfonate) salt, hydroxyethyl cellulose or a cellulose derivative is used.

The steric stabilizer makes the particle distribution of the PEDOT powder to be emulsion dispersed and polymerized uniformly, reduces the particle size to nano size, compensates for the lack of organic solvent affinity of PEDOT generated by the use of dopant, and is difficult to penetrate the solvent. It converts insoluble solid structure into soluble structure.

It is preferable that the addition amount of a steric stabilizer is 0.01-10 weight part with respect to 0.01-10 weight part of polymerization solvents.

If the amount of the steric stabilizer is less than 0.01 part by weight, the particle uniformity of the polymerized PEDOT nanopowder may be lowered, and the dispersibility (soluble) in the organic solvent may be lowered. Conductivity may be lowered.

The oxidizing agent is ammonium persulfate, ferrous ammonium sulfate, ferric sulfate, ferric perchlorate, potassium permanganate, potassium persulfate, dichromate Potassium (potassium dichromate), toluene iron (Iron (III) -toluene sulfonate) is one selected from the group consisting of.

The polymerization solvent is water, an organic solvent, a mixture of water and an organic solvent, and the like.

The polymerization reaction is preferably carried out for 20 to 80 hours at a temperature of -30 ℃ to 120 ℃.

As an example of a preferred manufacturing method, the dopant, the steric stabilizer, the oxidizing agent, and the polymerization solvent to which the monomer EDOT is added are stirred for about 48 hours, and then alcohol is added to the reaction vessel to terminate the polymerization reaction to precipitate the nanopowder of PEDOT. The polymerization solvent and alcohol solution of the upper layer are removed, the PEDOT nanopowder is recovered, washed with a large amount of distilled water and alcohol, and the PEDOT nanopowder is precipitated again and the washing / precipitation process of removing the distilled water and alcohol of the upper layer is repeated several times. To recover the PEDOT nanopowder.

Hereinafter, the present invention will be described in more detail with reference to Examples.

However, the present invention is not limited to the protection scope by the following examples.

Example 1

The monomer 3,4-ethylenedioxythiophene was purified by vacuum distillation, and ammonium persulfate as an oxidant and di (2-ethylhexyl) sulfosuccinic acid as a dopant were used in Japan TCI. 2-ethylhexyl) sulfosuccinic acid was chemically treated with di (2-ethylhexyl) sulfosuccinic acid sodium salt, and polyvinylpyrrolidone (PVP K60 with Mw = 160,000 by Fluka), a steric stabilizer, was also used as Fluka (Fluka). ) The product was used as it is.

0.2 mol di (2-ethylhexyl) sulfosulfic acid was added to 900 ml distilled water in a 2 L beaker at 0 ° C. and vigorously stirred with a mechanical stirrer, followed by 0.4 mol of 3,4-ethylenedioxythiophene and polyvinylpi Add Ralidone and continue stirring. Separately, 0.1 mol of ammonium persulfate is added to 100 ml of distilled water in a 500 ml beaker and stirred with a magnetic spoon. 0.1 mol ammonium persulfate solution is slowly added to 3,4-ethylenedioxythiophene and di (2-ethylhexyl) sulfosulfonic acid mixed solution at 0 ° C. The reaction is left under vigorous stirring with a mechanical stirrer for 48 hours.

After 48 hours, 1 liter of alcohol is added to the reaction vessel to terminate the synthesis reaction. After precipitation of the nano-sized particles after the synthesis is completed, the water and the alcohol solution of the upper layer is removed. In order to remove impurities and unreacted reagents contained in the precipitate from which water and alcohol have been removed, the resultant cake was frozen several times after washing with excess distilled water and alcohol. Into a drying tube, lyophilized under vacuum of 5 Torr for 48 hours.

In order to confirm the structure of the soluble poly (3,4-ethylenedioxythiophene) nanopowder (PEDOT nanopowder) using the steric stabilizer chemically prepared in the present invention, measurement results of the FT-IR spectrum as shown in FIG. PVP band vibration (vibration band) at 2850cm ^-1, from 1695cm ^-1 C = O (dopant di (2-ethylhexyl) sulfonic acid gunnery) vibration band (vibration band), 1557, in the CC, C at 1374cm ^-1 = C (thiophene) stretching vibration (stretching vibration), 1272, 1163 , 1108, CS in the stretching vibration, 873, 773, 641cm ^-1 of COC (3,4- ethylenedioxyphenyl thiophene) at 1082cm ^-1 The structure of the soluble poly (3,4-ethylenedioxythiophene) nano powder in which the anion represented by the general formula (II) was doped and the steric stabilizer was present was shown by showing the vibration band of (thiophene).

1 is a FI-TR spectrum of a PEDOT powder according to the present invention.

The particle size of the prepared PEDOT powder was measured using a scanning electron microscope (SEM) as shown in FIG. 2 and found to be several tens of nanometers.

2 is a scanning electron microscope (SEM) photograph of the PEDOT powder according to the present invention.

The dried poly (3,4-ethylenedioxythiophene) nano powder is formic acid, 1-methyl-2-pyrrolidone (NMP), dimethyl sulfoxide (DMSO), N, N'-dimethylformamide (DMF) Excellent for polar solvents such as o-chlorophenol, m-cresol, tetrahydrofuran (THF), acetic acid, trifluoroacetic acid, etc. and various non-polar solvents such as chloroform, dichloromethane, benzene, etc. It showed solubility and excellent solubility (dispersable more than 10% by weight) in organic solvents such as methyl ethyl ketone (MEK), toluene, ethyl acetate, and xylene, which are widely used in the present industry. Indicated.

As a result of preparing a solution in which 10 wt% of the PEDOT nanopowder was dissolved / dispersed in methyl ethyl ketone, gelation did not occur until 6 months, and thus solution stability was excellent.

From the solution of the prepared poly (3,4-ethylenedioxythiophene) nano powder in various organic solvents, a flexible film having a smooth surface state was obtained by a solution casting process. The measured electrical conductivity of the flexible film showed a value of 0.1-100 S / cm depending on the solvent used in preparing the solution.

Example 2

The monomer 3,4-ethylenedioxythiophene was purified by vacuum distillation, and ammonium persulfate as an oxidant and di (2-ethylhexyl) sulfosuccinic acid as a dopant were used in Japan TCI. 2-ethylhexyl) sulfosuccinic acid was chemically treated with di (2-ethylhexyl) sulfosuccinic acid sodium salt, and polyvinylpyrrolidone (PVP K60 with Mw = 160,000 by Fluka), a steric stabilizer, was also used as Fluka (Fluka). ) The product was used as it is.

0.2 mol of di (2-ethylhexyl) sulfosulfate salt at 0 ° C. was added to 900 ml distilled water in a 2 L beaker and vigorously stirred with a mechanical stirrer, followed by 0.4 mol of 3,4-ethylenedioxythiophene and polyvinyl. Pyrrolidone is added and stirring is continued. Separately, 0.2 mol of ammonium persulfate is added to 100 ml of distilled water in a 500 ml beaker and stirred with a magnetic spoon. 0.2 mol ammonium persulfate solution is slowly added to a mixed solution of 3,4-ethylenedioxythiophene and di (2-ethylhexyl) sulfosulfate sodium salt at 0 ° C. The reaction is left under vigorous stirring with a mechanical stirrer for 48 hours.

After 48 hours, 1 liter of alcohol is added to the reaction vessel to terminate the synthesis reaction. After precipitation of the nano-sized particles after the synthesis is completed, the water and the alcohol solution of the upper layer is removed. In order to remove impurities and unreacted reagents contained in the precipitate from which water and alcohol have been removed, the resultant cake was frozen several times after washing with excess distilled water and alcohol. Into a drying tube, lyophilized under vacuum of 5 Torr for 48 hours.

In order to confirm the structure of soluble poly (3,4-ethylenedioxythiophene) nanopowder (PEDOT nanopowder) using a chemically prepared steric stabilizer in the present invention, the FT-IR spectrum was measured at 2920-2850 cm ^-1 . PVP band vibration (vibration band), C = O at 1695cm ^-1 (dopant di (2-ethylhexyl) sulfonic acid gunnery) vibration band (vibration band), 1557, 1374cm ^-1 in the CC, C = C (Cy thiophene) stretching vibration (stretching vibration), CS (thiophene in stretching, 873, 773, 641cm ^-1 of 1272, 1163, 1108, COC ( 3,4- ethylenedioxyphenyl thiophene) at 1082cm ^-1) The structure of the soluble poly (3,4-ethylenedioxythiophene) nanopowder in which the anion represented by the general formula (II) was doped and the steric stabilizer was present was shown.

The dried poly (3,4-ethylenedioxythiophene) nano powder is formic acid, 1-methyl-2-pyrrolidone (NMP), dimethyl sulfoxide (DMSO), N, N'-dimethylformamide (DMF) Excellent for polar solvents such as o-chlorophenol, m-cresol, tetrahydrofuran (THF), acetic acid, trifluoroacetic acid, etc. and various non-polar solvents such as chloroform, dichloromethane, benzene, etc. It showed solubility and excellent solubility (dispersibility of more than 10% by weight) in organic solvents such as methyl ethyl ketone (MEK), toluene, ethyl acetate, and xylene, which are widely used in the industry. Indicated.

As a result of preparing a solution in which 10 wt% of the PEDOT nanopowder was dissolved / dispersed in methyl ethyl ketone, gelation did not occur until 6 months, and thus solution stability was excellent.

From the solution of the prepared poly (3,4-ethylenedioxythiophene) nano powder in various organic solvents, a flexible film having a smooth surface state was obtained by a solution casting process. The measured electrical conductivity of the flexible film showed a value of 0.1-100 S / cm depending on the solvent used in preparing the solution.

1 is a FI-IR spectrum of PEDOT powder according to the present invention.

Figure 2 is a scanning electron microscope (SEM) photograph of the PEDOT powder according to the present invention.

Claims (9)

A reaction vessel containing a polymerization solvent is added with a 3,4-ethylenedioxythiophene monomer of the general formula (I), a dopant of the general formula (II), and an oxidizing agent to polymerize and react to soluble poly (3,4-ethylene. In preparing dioxythiophene) powder, an additional steric stabilizer is further added to the reaction vessel before the polymerization reaction, The steric stabilizer is at least one member selected from the group consisting of polyvinyl alcohol, polyethylene oxide, poly (N-vinylpyrrolidone), poly (styrenesulfonate) salt, hydroxyethyl cellulose and cellulose derivatives. (3,4-ethylenedioxythiophene) A method for producing a nanopowder.

[In Formula (II), R and R 'are 2-ethylhexyl, 2-20 carbons, isoalkyl, alkoxy, alkoxyalkyl. ), Alkylsulfonyl, alkoxysulfonyl, alkylsilane or alkoxysilane, X is SO ₃ H, SO ₃ Na, sulfonate, carboxylate ), Phosphate, sulfate, cyanate, and silicate.] The dopant of general formula (II) is a salt of dialkylsulfosuccinic acid having 2 to 20 carbon atoms, aromatic sulfonic acid, aromatic sulfonic acid salt, and alkyl group having 1 to 10 carbon atoms. A method for producing a soluble poly (3,4-ethylenedioxythiophene) nanopowder, characterized in that one or a mixture selected from the group consisting of alkyl sulfate having and dialkyl sulfate having 1 to 10 carbon atoms.        The dialkyl sulfosuccinic acid having 2 to 20 carbon atoms is di (2-ethylhexyl) sulfosuccinic acid, and the salt of dialkyl sulfosuccinic acid having 2 to 20 carbon atoms is sodium of di (2-ethylhexyl) sulfosuccinic acid. It is a salt, The manufacturing method of the soluble poly (3, 4- ethylene dioxythiophene) nano powder. delete The method for producing soluble poly (3,4-ethylenedioxythiophene) nano powder according to claim 1, wherein the amount of the steric stabilizer added is 0.01 to 10 parts by weight based on 100 parts by weight of the polymerization solvent. The method of claim 1 wherein the oxidizing agent is ammonium persulfate, ferrous ammonium sulfate, ferric sulfate, ferric perchlorate, potassium permanganate, potassium peroxide soluble poly (3,4-ethylenedioxythiophene), characterized in that one or two or more selected from the group consisting of persulfate, potassium dichromate, and toluene sulfate (Iron (III) -toluene sulfonate) ) Nano powder production method. The method for producing a soluble poly (3,4-ethylenedioxythiophene) nanopowder according to claim 1, wherein the polymerization solvent is one selected from the group consisting of water, an organic solvent, and a mixture of water and an organic solvent. The method according to claim 1, wherein the polymerization is carried out at a temperature of -30 ° C to 120 ° C for 20 minutes to 80 hours. The soluble poly (3,4-ethylenedioxythi) compound according to claim 1, wherein the polymerized soluble poly (3,4-ethylenedioxythiophene) nanopowder is precipitated and then washed with distilled water and alcohol. Offen) nano powder production method.

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