JP7159688B2 - Ink containing conductive polymer and use thereof - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel conductive polymer-containing ink capable of producing a conductive polymer film having both good hole transportability and durability.

Conductive polymer materials have been developed by doping π-conjugated polymers such as polyacetylene, polythiophene, polyaniline, and polypyrrole with electron-accepting compounds as dopants. Applications to paints, electromagnetic wave shields, electrochromic devices, electrode materials, hole injection materials, thermoelectric conversion materials, transparent conductive films, chemical sensors, actuators, etc. are being investigated. Among these conductive polymer materials, polythiophene-based conductive polymer materials are practically useful in terms of chemical stability.

As a polythiophene-based conductive polymer material, (i) obtained by polymerizing 3,4-ethylenedioxythiophene (EDOT) in an aqueous solution of polystyrene sulfonic acid (PSS) or perfluoroethylene sulfonic acid as a dopant. Aqueous dispersions containing PEDOT/PSS and PEDOT/perfluoroethylenesulfonic acid, and (ii) substituents (sulfo group, sulfonate group, etc.) that have both water-solubility and doping effects are added directly or via a spacer to the polymer. So-called self-doping type conductive polymers having in the main chain (e.g., sulfonated polyaniline, PEDOT-S, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2 -yl)methoxy]-1-methyl-1-propanesulfonic acid polymer, etc.) are known (see, for example, Non-Patent Documents 1 and 2 and Patent Document 1).

The applications of conductive polymers are not limited to conventional antistatic agents and solid electrolytes in solid electrolytic capacitors, but are also being developed as hole injection layers for organic electroluminescence devices and organic thin-film solar cells. .

The hole injection layer is an organic thin film of several tens to several tens of nm obtained by applying and drying the ink containing the conductive polymer on the transparent electrode, and has a moderate conductivity (10 ^-3 S/ cm) and smoothness are required. Reported examples of inks containing the above conductive polymers include, for example, PEDOT/PSS, which contains 10 to 50% by weight, typically 30% by weight, of a solvent having a boiling point higher than that of water, such as ethylene glycol. An ink that is an aqueous dispersion has been reported (Patent Document 2). Further, an aqueous dispersion containing 5 to 50% by weight of an alcohol solvent such as methanol, ethanol or 1-propanol or an alcohol ether solvent such as 2-butoxyethanol has been reported (Patent Document 3). Furthermore, in the case of PEDOT/perfluoroethylenesulfonic acid, an aqueous dispersion containing an alcohol such as isopropanol and containing at least 40% by weight of H ₂ O has been reported (Patent Document 4).

In addition, as an application example of the hole injection layer of the self-doping polythiophene-based conductive polymer, although there are no specific examples, it contains 0.001 to 10% by weight of a monovalent or divalent alcohol. A description of a good water-soluble ink is written in the specification (Patent Document 5).

Thus, conventional polythiophene-based conductive polymer-containing inks used for hole injection layers contain 50% by weight or more of water.

On the other hand, as a method for applying the conductive polymer-containing ink onto the transparent electrode, a spin coating method or the like is usually frequently used. It is desirable to apply at In the inkjet method, the ink dropped onto the target pixel is spread uniformly within the pixel to form a thin film with a uniform film thickness. causes problems such as clogging. Therefore, it is necessary to have suitable ink viscosity (25 mPa·s or less) and surface tension (40 mN/m or less), and to be capable of continuous ejection by the inkjet method, which is not satisfactory at present.

International Publication No. 2014/007299 Pamphlet Japanese Patent No. 5235660 Japanese Patent Publication No. 2006-520994 Japanese Patent Publication No. 2006-500463 JP 2017-222831 A

Journal of American Chemical Society, 112, 2801-2803 (1990) Advanced Materials, Vol. 23 (38) 4403-4408 (2011)

As described above, conventionally known inks containing polythiophene-based conductive polymers (e.g., PEDOT:PSS) contain water in an amount of 50% by weight or more. It is also a deterioration factor and increases the probability of occurrence of so-called dark spots (non-light-emitting regions), resulting in a problem of reduced durability and product yield of organic devices. In addition, conventionally known polythiophene-based conductive polymers have a problem that they tend to clog at the tip of the nozzle due to the dispersion liquid. Therefore, there is a demand for a composition (ink) containing a polythiophene-based conductive polymer that has a water content of less than 50% and is free from the problem of nozzle clogging in the inkjet method.

The present inventors have made intensive studies to solve the above problems, and as a result, the conductive polymer-containing composition (ink) described later has a water content of less than 50% by weight, but the nozzle clogging in the inkjet method The inventors have found that the problem can be solved, and have completed the present invention.

That is, the present invention resides in the following [1] to [16].
[1] Polythiophene (A) containing at least one structural unit selected from the group consisting of structural units represented by the following formula (1) and structural units represented by the following formula (2), polyacrylic acid-based water-soluble A composition comprising a resin (B), a glycol (C), a glycol ether (D) represented by the following general formula (3), and an aprotic polar solvent (E), comprising (A) and (B) , the contents of (C) and (D) are 0.005 to 1.0% by weight, 0.1 to 10% by weight, 0.01 to 30% by weight, and 0.01 to 30% by weight, respectively. and the sum of (C), (D) and (E) is 60 to 99% by weight.

[In Formula (1), M represents a hydrogen ion, an alkali metal ion, a conjugate acid of an amine compound, or a quaternary ammonium cation. In formulas (1) and (2), R ¹ is a hydrogen atom, a methyl group, an ethyl group, a linear or branched alkyl group having 3 to 6 carbon atoms, or a substituted alkyl group having 1 to 6 carbon atoms. represents a group or a fluorine atom, m represents an integer of 1 to 10, and n represents 0 or 1. ]

(In the formula, R ² represents a linear or branched alkyl group having 3 to 6 carbon atoms; R ³ and R ⁴ each independently represent a hydrogen atom or a methyl group; p represents 1 or 2; .)
[2] The composition according to [1], wherein the total of (C), (D) and (E) is 70 to 98% by weight.
[3] The composition according to [1], wherein the total of (C), (D) and (E) is 80 to 98% by weight.
[4] Any one of [1] to [3], characterized by containing 5 to 40 parts by weight of the polyacrylic acid-based water-soluble resin (B) with respect to 1 part by weight of the polythiophene (A). The composition according to .
[5] the group in which glycol (C) consists of ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butylene glycol, 2,3-butanediol, and 2-methyl-2,4-pentanediol; The composition according to any one of [1] to [4], which is at least one selected from the above.
[6] The composition according to any one of [1] to [5], wherein the content of glycol (C) is 0.1 to 15% by weight.
[7] Glycol ether (D) is ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-n-butyl ether, diethylene glycol mono-n-propyl ether, diethylene glycol mono-n. -butyl ether, dipropylene glycol mono-n-propyl ether, or dipropylene glycol mono-n-butyl ether, the composition according to any one of [1] to [6].
[8] The composition according to any one of [1] to [7], wherein the content of glycol ether (D) is 0.1 to 15% by weight.
[9] The aprotic polar solvent (E) is at least one selected from the group consisting of dimethylformamide, dimethylacetamide, diethylacetamide, N-methylpyrrolidone, and N-ethylpyrrolidone [1] ] to [8].
[10] Polyacrylic acid-based water-soluble resin (B) is polyacrylic acid, polymethacrylic acid, poly(acrylic acid-styrenesulfonic acid) copolymer, or poly(methacrylic acid-styrenesulfonic acid) copolymer The composition according to any one of [1] to [9], characterized in that
[11] The composition according to any one of [1] to [10], wherein the polyacrylic acid-based water-soluble resin (B) has a weight average molecular weight of 1,000 to 500,000.
[12] The composition according to any one of [1] to [11], further comprising water.
[13] The composition according to any one of [1] to [12], which has a viscosity at 20° C. of 20 mPa·s or less and a surface tension of 20 to 40 mN/m. .
[14] An ink containing a conductive polymer, comprising the composition according to any one of [1] to [13].
[15] A method for producing a film, comprising applying the composition according to any one of [1] to [13] and then drying the composition.
[16] An organic electronic device, either an organic electroluminescence device or an organic photoelectric conversion device, comprising the film obtained by the production method described in [15].

Conductive polymer films prepared from the novel conductive polymer-containing composition (ink) of the present invention have a negative effect on device life compared to those prepared from conventionally known conductive polymer-containing compositions. Since the water content in the ink is small, remarkable effects such as high durability and high performance can be obtained.

In addition, the novel conductive polymer-containing composition (ink) of the present invention has appropriate ink viscosity and surface tension, and therefore has ink properties suitable for the inkjet method, which is advantageous in terms of process as a printing method for large substrates.

The conductive polymer-containing composition (ink) of the present invention can be adjusted to a lower surface tension by controlling the water content to a low level, so compared to a conductive ink containing PEDOT/PSS, it can be used by an inkjet method. It is possible to improve the uniformity of the coating film.

The conductive polymer-containing composition (ink) of the present invention has the effects of having higher heat resistance and decomposition resistance than conductive inks containing PEDOT/PSS and excellent storage stability. In addition, based on such durability, the conductive polymer-containing composition (ink) of the present invention is significantly less prone to clogging at the tip of an inkjet nozzle than a conductive ink containing PEDOT/PSS. effect.

The present invention will be described in detail below.

The present invention provides a polythiophene (A) containing at least one structural unit selected from the group consisting of structural units represented by the following formula (1) and structural units represented by the following formula (2): A composition comprising a polar resin (B), a glycol (C), a glycol ether (D) represented by the following general formula (3), and an aprotic polar solvent (E), wherein (A), (B ), the contents of (C) and (D) are respectively 0.005 to 1.0% by weight, 0.1 to 10% by weight, 0.01 to 30% by weight, and 0.01 to 30% by weight. and the total of (C), (D) and (E) is 60 to 99% by weight.

[In Formula (1), M represents a hydrogen ion, an alkali metal ion, a conjugate acid of an amine compound, or a quaternary ammonium cation. In formulas (1) and (2), R ¹ is a hydrogen atom, a methyl group, an ethyl group, a linear or branched alkyl group having 3 to 6 carbon atoms, or a substituted alkyl group having 1 to 6 carbon atoms. represents a group or a fluorine atom, m represents an integer of 1 to 10, and n represents 0 or 1. ]

(In the formula, R ² represents a linear or branched alkyl group having 3 to 6 carbon atoms; R ³ and R ⁴ each independently represent a hydrogen atom or a methyl group; p represents 1 or 2; .)
In formula (1) above, M represents a hydrogen ion, an alkali metal ion, a conjugate acid of an amine compound, or a quaternary ammonium cation.

Examples of the alkali metal ions include, but are not limited to, Li ions, Na ions, K ions, Rb ions, and Cs ions. Ions are practically preferred.

The conjugate acid of the amine compound is a cationic species obtained by adding hydron (H+) to the amine compound. The amine compound is not particularly limited as long as it reacts with a sulfonic acid group to form a conjugate acid. For example, it is represented by N(R ⁵ ) ₃ having an sp3 hybrid orbital. An amine compound [conjugate acid is represented by [NH(R ⁵ ) ₃ ] ⁺ . ], or an amine compound having an sp2 hybrid orbital (for example, a pyridine compound, an imidazole compound), or the like.

The above substituent R ⁵ is not particularly limited, but each independently represents a hydrogen atom, a methyl group, an ethyl group, a linear or branched alkyl group having 3 to 6 carbon atoms, or a substituent. represents an alkyl group having 1 to 6 carbon atoms.

The linear or branched alkyl group having 3 to 6 carbon atoms is not particularly limited, but examples include n-propyl group, isopropyl group, n-butyl group, isobutyl group and sec-butyl group. , tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, tert-pentyl group, cyclopentyl group, n-hexyl group, 2-ethylbutyl group, cyclohexyl group and the like.

The substituted alkyl group having 1 to 6 carbon atoms is not particularly limited, but examples thereof include a substituted methyl group, a substituted ethyl group, and a substituted The linear or branched alkyl group having 3 to 6 carbon atoms having the substituent is not particularly limited, but for example, the substituent an n-propyl group having a substituent, an isopropyl group having a substituent, an n-butyl group having a substituent, an isobutyl group having a substituent, a sec-butyl group having a substituent, a tert-butyl group having a substituent, a substituent n-pentyl group having a substituent, isopentyl group having a substituent, neopentyl group having a substituent, tert-pentyl group having a substituent, cyclopentyl group having a substituent, n-hexyl group having a substituent, having a substituent A 2-ethylbutyl group, a cyclohexyl group having a substituent, and the like can be mentioned.

Further, the substituent in the alkyl group having 1 to 6 carbon atoms having the above substituent is not particularly limited, but examples thereof include halogen atoms (fluorine atom, chlorine atom, bromine atom, iodine atom, etc.), amino and a group selected from the group consisting of a hydroxy group, and the alkyl group having 1 to 6 carbon atoms having the substituent is not particularly limited, but specifically includes a trifluoromethyl group, A 2-hydroxyethyl group, a 2-hydroxypropyl group and the like are exemplified.

Among these, the substituent R ⁵ is independently preferably a hydrogen atom, a methyl group, an ethyl group, or a 2-hydroxyethyl group.

The amine compound represented by N(R ⁵ ) ₃ forming the conjugate acid of the above amine compound is not particularly limited, but examples thereof include ammonia, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine and triethylamine. , normal-propylamine, isopropylamine, normal-butylamine, tert-butylamine, hexylamine, ethanolamine compounds (e.g., aminoethanol, dimethylaminoethanol, methylaminoethanol, diethanolamine, N-methyldiethanolamine, triethanolamine), 3- amino-1,2-propanediol, 3-methylamino-1,2-propanediol, 3-dimethylamino-1,2-propanediol, 1,4-butanediamine, and the like.

In addition, the amine compound having an sp2 hybrid orbital that forms the conjugate acid of the amine compound is not particularly limited, but examples thereof include imidazole compounds (e.g., imidazole, N-methylimidazole, or 1,2-dimethyl imidazole, etc.), pyridine, picoline, or lutidine.

Among these, the amine compound used as the conjugate acid of the amine compound is preferably ammonia, monoethanolamine, diethanolamine, triethanolamine, or imidazole.

That is, the conjugate acid of the amine compound is preferably ammonium, the conjugate acid of monoethanolamine, the conjugate acid of diethanolamine, the conjugate acid of triethanolamine, or the conjugate acid of imidazole in terms of excellent conductivity.

Examples of the quaternary ammonium cation include, but are not limited to, tetramethylammonium cation, tetraethylammonium cation, tetra-normal propylammonium cation, tetra-normal butylammonium cation, or tetra-normal hexylammonium cation. be done. Among these, tetramethylammonium cation or tetraethylammonium cation is preferable from the viewpoint of availability.

In the above formulas (1) and (2), R ¹ is a hydrogen atom, a methyl group, an ethyl group, a linear or branched alkyl group having 3 to 6 carbon atoms, a substituted represents an alkyl group or a fluorine atom.

The linear or branched alkyl group having 3 to 6 carbon atoms is not particularly limited, but examples include n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, tert-pentyl group, cyclopentyl group, n-hexyl group, 2-ethylbutyl group, cyclohexyl group and the like.

The substituted alkyl group having 1 to 6 carbon atoms is not particularly limited, but examples thereof include a substituted methyl group, a substituted ethyl group, and a substituted C 3 to 6 The linear or branched alkyl group having 3 to 6 carbon atoms having the substituent is not particularly limited, but for example, the substituent an n-propyl group having a substituent, an isopropyl group having a substituent, an n-butyl group having a substituent, an isobutyl group having a substituent, a sec-butyl group having a substituent, a tert-butyl group having a substituent, a substituent n-pentyl group having a substituent, isopentyl group having a substituent, neopentyl group having a substituent, tert-pentyl group having a substituent, cyclopentyl group having a substituent, n-hexyl group having a substituent, having a substituent A 2-ethylbutyl group, a cyclohexyl group having a substituent, and the like can be mentioned.

Further, the substituent in the alkyl group having 1 to 6 carbon atoms having the above substituent is not particularly limited, but examples thereof include halogen atoms (fluorine atom, chlorine atom, bromine atom, iodine atom, etc.), amino and a group selected from the group consisting of a hydroxy group, and the alkyl group having 1 to 6 carbon atoms having the substituent is not particularly limited, but specifically includes a trifluoromethyl group, A 2-hydroxyethyl group, a 2-hydroxypropyl group and the like are exemplified.

R ¹ in formulas (1) and (2) above is preferably a hydrogen atom, a methyl group, an ethyl group, or a fluorine atom from the viewpoint of film-forming properties.

In formulas (1) and (2) above, m represents an integer of 1 to 10, preferably an integer of 1 to 4, and more preferably 2.

In the above formulas (1) and (2), n represents 0 or 1, preferably 1.

The structural unit represented by formula (2) above represents the doping state of the structural unit represented by formula (1) above.

Dopants that cause an insulator-metal transition upon doping can be divided into acceptors and donors. The former enters the vicinity of the polymer chain of the conductive polymer by doping and deprives the conjugated system of the main chain of π electrons. As a result, positive charges (holes, holes) are injected onto the main chain, so they are also called p-type dopants. In addition, the latter gives electrons to the conjugated system of the main chain, and these electrons move in the conjugated system of the main chain, so it is also called an n-type dopant.

The dopants in the present invention are sulfo or sulfonate groups covalently attached to the backbone of the polymer molecule and are p-type dopants. A polymer that exhibits conductivity without adding a dopant from the outside is called a self-doping type conductive polymer.

The polythiophene (A) of the present invention can be produced by polymerizing a thiophene monomer represented by the following formula (4) in water or an alcohol solvent in the presence of an oxidizing agent.

[In formula (4), R ¹ , m, and n have the same definitions as R ¹ , m, and n in formulas (1) and (2) above. M represents a metal ion. ]
Metal ions represented by M in formula (4) are not particularly limited, but transition metal ions, noble metal ions, nonferrous metal ions, alkali metal ions (e.g., Li ions, Na ions, and K ions). , alkaline earth metal ions, and the like.

The polythiophene (A) obtained by polymerizing the thiophene monomer represented by the above formula (4) is a metal salt. With regard to the metal salt, if necessary, M can be converted to a hydrogen ion by treatment with an acid, and by further treating this (hydrogen ion conversion product) with an amine compound, M is conjugated with the amine compound. The acid polythiophene (A) is obtained.

Specific examples of the thiophene monomer represented by the above formula (4) include 6-(2,3-dihydro-thieno[3,4-b][1,4]dioxin-2-yl)hexane-1 -sulfonic acid, sodium 6-(2,3-dihydro-thieno[3,4-b][1,4]dioxin-2-yl)hexane-1-sulfonate, 6-(2,3-dihydro-thieno Lithium [3,4-b][1,4]dioxin-2-yl)hexane-1-sulfonate, 6-(2,3-dihydro-thieno[3,4-b][1,4]dioxin- 2-yl)hexan-1-sulfonic acid potassium, 8-(2,3-dihydro-thieno[3,4-b][1,4]dioxin-2-yl)octane-1-sulfonic acid, 8-( Sodium 2,3-dihydro-thieno[3,4-b][1,4]dioxin-2-yl)octane-1-sulfonate and 8-(2,3-dihydro-thieno[3,4-b ][1,4]dioxin-2-yl)potassium octane-1-sulfonate, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy] -1-sodium propanesulfonate, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-potassium propanesulfonate, 3-[( Sodium 2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-methyl-1-propanesulfonate, 3-[(2,3-dihydrothieno[3, 4-b]-[1,4]dioxin-2-yl)methoxy]-1-ethyl-1-propanesulfonate sodium, 3-[(2,3-dihydrothieno[3,4-b]-[1, 4]dioxin-2-yl)methoxy]-1-propyl-1-propanesulfonate, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl) Sodium methoxy]-1-butyl-1-propanesulfonate, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-pentyl-1 - sodium propanesulfonate, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-hexyl-1-propanesulfonate, 3- [(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-isopropyl- Sodium 1-propanesulfonate, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-isobutyl-1-propanesulfonate, 3 -[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-isopentyl-1-propanesulfonate sodium, 3-[(2,3-dihydrothieno Sodium [3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-fluoro-1-propanesulfonate, 3-[(2,3-dihydrothieno[3,4-b]- [1,4]dioxin-2-yl)methoxy]-1-methyl-1-propanesulfonic acid potassium, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2 -yl)methoxy]-1-methyl-1-propanesulfonic acid, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-methyl -1-propanesulfonate ammonium, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-methyl-1-propanesulfonate triethylammonium , sodium 4-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-butanesulfonate, 4-[(2,3-dihydrothieno[3 ,4-b]-[1,4]dioxin-2-yl)methoxy]-1-butanesulfonic acid potassium, 4-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin -2-yl)methoxy]-1-methyl-1-butanesulfonate sodium, 4-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]- Potassium 1-methyl-1-butanesulfonate, 4-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-fluoro-1-butanesulfone sodium acid, or potassium 4-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-fluoro-1-butanesulfonate, etc. .

In the glycol ether (D) represented by general formula (3), R ² represents a linear or branched alkyl group having 3-6 carbon atoms. R ³ and R ⁴ each independently represent a hydrogen atom or a methyl group.

The linear or branched alkyl group having 3 to 6 carbon atoms in R ² is not particularly limited, but examples include n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, tert-pentyl group, cyclopentyl group, n-hexyl group, 2-ethylbutyl group, cyclohexyl group and the like.

R ² is preferably a linear or branched alkyl group having 3 or 4 carbon atoms from the viewpoint of excellent solubility and dispersibility of the polythiophene (A) and the polyacrylic acid-based water-soluble resin (B). n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, or tert-butyl groups are more preferred.

Regarding R ³ and R ⁴ , both are hydrogen atoms, or one is a methyl group and the other is a hydrogen atom, in terms of excellent solubility and dispersibility of the polythiophene (A) and the polyacrylic acid-based water-soluble resin (B). Atoms are preferred.

In the glycol ether (D) represented by the general formula (3), p represents 1 or 2, but p is preferably 1 from the viewpoint of film-forming properties.

The glycol ether (D) represented by the general formula (3) is not particularly limited, but examples include ethylene glycol monoalkyl ether, diethylene glycol monoalkyl ether, propylene glycol monoalkyl ether, or dipropylene glycol monoalkyl ethers.

Examples of the ethylene glycol monoalkyl ether include, but are not limited to, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono n-propyl ether, ethylene glycol mono iso-propyl ether, ethylene glycol mono n-butyl ether, ethylene glycol mono iso-butyl ether, ethylene glycol mono sec-butyl ether, ethylene glycol mono tert-butyl ether, ethylene glycol mono n-pentyl ether, ethylene glycol mono iso-pentyl ether, ethylene glycol mono neo-pentyl ether, ethylene Glycol mono-tert-pentyl ether, ethylene glycol mono-n-hexyl ether, ethylene glycol mono-iso-hexyl ether and the like can be mentioned.

Examples of the diethylene glycol monoalkyl ether include, but are not limited to, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono n-propyl ether, diethylene glycol mono iso-propyl ether, diethylene glycol mono n-butyl ether, diethylene glycol mono iso-butyl ether, diethylene glycol mono sec-butyl ether, diethylene glycol mono tert-butyl ether, diethylene glycol mono n-pentyl ether, diethylene glycol mono iso-pentyl ether, diethylene glycol mono neo-pentyl ether, diethylene glycol mono tert-pentyl ether, diethylene glycol mono n-hexyl ether , or diethylene glycol mono-iso-hexyl ether.

The propylene glycol monoalkyl ether is not particularly limited, but examples include propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono n-propyl ether, propylene glycol mono iso-propyl ether, propylene glycol mono n-butyl ether, propylene glycol mono iso-butyl ether, propylene glycol mono sec-butyl ether, propylene glycol mono tert-butyl ether, propylene glycol mono n-pentyl ether, propylene glycol mono iso-pentyl ether, propylene glycol mono neo-pentyl ether, propylene Glycol mono-tert-pentyl ether, propylene glycol mono-n-hexyl ether, propylene glycol mono-iso-hexyl ether and the like can be mentioned.

Examples of the dipropylene glycol monoalkyl ether include, but are not limited to, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, and dipropylene glycol mono-iso-propyl. Ether, dipropylene glycol mono n-butyl ether, dipropylene glycol mono iso-butyl ether, dipropylene glycol mono sec-butyl ether, dipropylene glycol mono tert-butyl ether, dipropylene glycol mono n-pentyl ether, dipropylene glycol mono iso-pentyl ether, dipropylene glycol mono neo-pentyl ether, dipropylene glycol mono tert-pentyl ether, dipropylene glycol mono n-hexyl ether, dipropylene glycol mono iso-hexyl ether and the like.

Regarding the glycol ether (D) represented by the general formula (3), ethylene glycol mono-n-propyl ether, ethylene glycol mono-iso-propyl ether, and ethylene glycol mono-iso-propyl ether are used because the flatness of the organic thin film produced from the composition of the present invention is excellent. ether, ethylene glycol mono n-butyl ether, ethylene glycol mono iso-butyl ether, ethylene glycol mono sec-butyl ether, ethylene glycol mono tert-butyl ether, diethylene glycol mono n-propyl ether, diethylene glycol mono iso-propyl ether, diethylene glycol mono n-butyl ether, Diethylene glycol mono iso-butyl ether, diethylene glycol mono sec-butyl ether, diethylene glycol mono tert-butyl ether, propylene glycol mono n-propyl ether, propylene glycol mono iso-propyl ether, propylene glycol mono n-butyl ether, propylene glycol mono iso-butyl ether, propylene glycol mono sec-butyl ether, propylene glycol mono tert-butyl ether, dipropylene glycol mono n-propyl ether, dipropylene glycol mono iso-propyl ether, dipropylene glycol mono n-butyl ether, dipropylene glycol mono iso-butyl ether, dipropylene glycol mono more preferably sec-butyl ether or dipropylene glycol mono tert-butyl ether, ethylene glycol mono n-propyl ether, ethylene glycol mono n-butyl ether, propylene glycol mono n-propyl ether, propylene glycol mono n-butyl ether, diethylene glycol Mono-n-propyl ether, diethylene glycol mono-n-butyl ether, dipropylene glycol mono-n-propyl ether, or dipropylene glycol mono-n-butyl ether are more preferred.

As for the glycol ether (D) represented by the general formula (3), a pure product may be used alone, or a plurality of glycol ethers may be used in combination.

The content of the glycol ether (D) represented by the general formula (3) in the present invention is 0.01 to 30% by weight. From the viewpoint of excellent properties, the content is preferably 0.1 to 20% by weight, more preferably 0.1% by weight or more and 15% by weight or less.

The composition of the present invention is characterized by containing a glycol (C).

Examples of the glycol (C) include, but are not limited to, ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butylene glycol, 2,3-butanediol, and 1,4-butane. Diol, 1,5-pentanediol, 2-butene-1,4-diol, 2-methyl-2,4-pentanediol, diethylene glycol, dipropylene glycol, triethylene glycol, glycerin, or 1,2,6-hexane triol and the like.

Among these, glycol (C) having a boiling point of 220° C. or less is preferable in that the drying rate from the composition of the present invention is fast. ° C.), 1,3-propanediol (boiling point 210° C.), 1,3-butylene glycol (boiling point 207° C.), 2,3-butanediol (boiling point 182° C.), or 2-methyl-2,4-pentanediol (boiling point 197°C) is preferred.

The content of glycol (C) in the composition of the present invention is 0.01 to 30% by weight. The content of the glycol (C) is preferably 0.1 to 20% by weight, preferably 0.1 to 15% by weight, in terms of smoothness and low viscosity during film formation of the composition of the present invention. % is more preferable.

Although the polythiophene (A) used in the present invention is not particularly limited, it preferably exhibits an electrical conductivity of 10 S/cm or more in the form of a film (electrical conductivity). .

The content (composition) of polythiophene (A) in the composition of the present invention is 0.005 to 1.0% by weight. The content (composition) of the polythiophene (A) is preferably 0.01% by weight to 0.5% by weight, and more preferably 0.02% by weight to 0.02% by weight, in order to exhibit excellent performance as a hole injection material. More preferably 0.3% by weight.

The polyacrylic acid-based water-soluble resin (B) in the composition of the present invention is not particularly limited, but may be a homopolymer of an αβ unsaturated carboxylic acid compound such as acrylic acid, methacrylic acid, maleic acid, or these. can be mentioned. Examples of the homopolymer include, but are not limited to, polyacrylic acid, polymethacrylic acid, and the like. Examples of the above-mentioned copolymer include copolymers obtained by using at least one αβ-unsaturated carboxylic acid monomer and a comonomer. Anything that is possible can be used. The copolymer is not particularly limited, but for example, poly(acrylic acid-methacrylic acid) copolymer, poly(acrylic acid-hydroxyethyl acrylate) copolymer, poly(acrylic acid-maleic acid) copolymer, poly(acrylic acid-vinylsulfonic acid) copolymer, poly(acrylic acid-styrenesulfonic acid) copolymer, poly(methacrylic acid-styrenesulfonic acid) copolymer, or poly(hydroxyethyl methacrylate- styrenesulfonic acid) copolymers, and the like. The copolymer may be a block copolymer, a random copolymer, or an alternating polymer.

As the polyacrylic acid-based water-soluble resin (B), polyacrylic acid, polymethacrylic acid, poly(acrylic acid-styrenesulfonic acid) copolymer, or poly( A methacrylic acid-styrenesulfonic acid) copolymer is preferred.

The polyacrylic acid-based water-soluble resin (B) of the present invention is not particularly limited. 300,000 is more preferable.

The content (composition) of the polyacrylic acid-based water-soluble resin (B) in the composition of the present invention is 0.1 to 10% by weight. The content (composition) of the polyacrylic acid-based water-soluble resin (B) is preferably 0.3 to 5.0% by weight in terms of easily controlling the viscosity of the composition of the present invention. , more preferably 0.5 to 3.0% by weight.

In addition, in the composition of the present invention, the weight ratio of the polyacrylic acid-based water-soluble resin (B) and the polythiophene (A) can be easily controlled appropriately as a hole injection material for organic electric elements. The weight ratio (weight / weight) represented by (B) / (A) preferably satisfies 1 to 40, more preferably satisfies 5 to 40, more preferably satisfies 15 to 40, 20 to 40 is more preferred.

The aprotic polar solvent (E) is not particularly limited, but is preferably an aprotic polar solvent having a boiling point of 150 to 240° C. Examples include dimethylformamide, dimethylacetamide, diethylacetamide, It is preferably at least one selected from the group consisting of N-methylpyrrolidone and N-ethylpyrrolidone.

In the composition of the present invention, the content (composition) of the aprotic polar solvent (E) is preferably 30 to 95% by weight, more preferably 40 to 90% by weight, from the viewpoint of the solubility of the polythiophene (A). and more preferably 50 to 85% by weight.

The composition of the present invention comprises the above polythiophene (A), polyacrylic acid-based water-soluble resin (B), glycol (C), glycol ether (D) represented by the above general formula (3), and aproton A composition containing a polar solvent (E), and the contents of (A), (B), (C) and (D) are 0.005 to 1.0% by weight and 0.1 to 10% by weight, respectively. % by weight, 0.01 to 30% by weight, and 0.01 to 30% by weight, and the total content of (C), (D), and (E) is 60 to 99% by weight characterized by The total content of (C), (D) and (E) is preferably 70 to 98% by weight, more preferably 80 to 98% by weight.

The composition of the present invention preferably further contains water as its component. The water content is preferably 0.01 to 30% by weight, more preferably 0.01 to 20% by weight, more preferably 0.01 to 15% by weight. 0.01 to 10% by weight is more preferred.

In addition, the composition of the present invention preferably has a viscosity at 20° C. of 25 mPa·s or less and a surface tension of 15 to 50 mN/m, respectively, from the viewpoint of excellent wettability to the substrate. More preferably, they are 20 mPa·s or less and 20 to 40 mN/m, respectively.

The composition of the present invention may optionally contain a surfactant. Examples of the surfactant include, but are not limited to, polymeric nonionic surfactants, amphoteric surfactants, fluorine-based surfactants, and silicone-based surfactants.

Examples of the polymeric nonionic surfactant include, but are not particularly limited to, polyvinylpyrrolidone, a copolymer of polyvinylpyrrolidone, and polyalkylene glycol. The average molecular weight of the polyvinylpyrrolidone used in the present invention is preferably 1,000 to 2,000,000, preferably 10,000 to 1,500,000. The polyvinylpyrrolidone copolymer is not particularly limited, but preferably has both a hydrophilic portion and a hydrophobic portion in the polymer chain. pyrrolidone-vinyl acetate] block copolymer, [vinylpyrrolidone-methyl methacrylate] copolymer, [vinylpyrrolidone-n-butyl methacrylate] copolymer, or [vinylpyrrolidone-acrylamide] copolymer.

In addition, the polyalkylene glycol is not particularly limited, but for example, manufactured by Sanyo Chemical Industries, Ltd., trade names: Newpol PE-61, PE-62, PE-64, PE-68, PE-71 , PE-74, PE-75, PE-78, PE-108, PE-128, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade names: Epan 450, 750, 785, U-103, U-105, U108, etc. Polyethylene glycol/polypropylene glycol block polymers of Sanyo Chemical Industries, Ltd., trade name: Sannics GP-250, GP-400, GP-600, GP-1000, GP-3000, GP-4000 and other polyoxy An example is propylated glycerin.

Examples of the amphoteric surfactant include, but are not limited to, betaine-type amphoteric surfactants. The betaine-type amphoteric surfactant is not particularly limited, but examples thereof include alkyldimethylbetaine, lauryldimethylbetaine, stearyldimethylbetaine, lauryldihydroxyethylbetaine, and the like.

The fluorosurfactant is not particularly limited as long as it has a perfluoroalkyl group. Examples include perfluoroalkane, perfluoroalkylcarboxylic acid, perfluoroalkylsulfonic acid, or perfluoroalkylethylene oxide adduct etc.

Examples of the silicone-based surfactant include, but are not limited to, polyether-modified polydimethylsiloxane, polyetherester-modified polydimethylsiloxane, hydroxyl group-containing polyether-modified polydimethylsiloxane, and acrylic group-containing polyether-modified polydimethylsiloxane. , acrylic group-containing polyester-modified polydimethylsiloxane, perfluoropolyether-modified polydimethylsiloxane, perfluoropolyester-modified polydimethylsiloxane, or silicone-modified acrylic compound.

Fluorine-based surfactants and silicone-based surfactants are effective as leveling agents for improving the flatness of the coating film of the composition of the present invention.

Surfactants other than those described above include, but are not particularly limited to, acetylene glycol-type surfactants.

The method for preparing the composition of the present invention is not particularly limited. Glycol (C), glycol ether (D) and aprotic polar solvent (E) represented by the above general formula (3), water if necessary, and other additives if necessary, of the present invention A mixing method can be arbitrarily included within the range. The order of mixing the components is not particularly limited, and the composition of the present invention can be prepared by mixing the components in any order.

Here, the temperature at which each component is mixed is not particularly limited.

The atmosphere during mixing is not particularly limited, but may be air or an inert gas.

When mixing the composition of the present invention, in addition to a general mixing and dissolving operation using a stirrer tip, stirring blades, etc., ultrasonic irradiation, homogenization treatment (e.g., mechanical homogenizer, ultrasonic homogenizer, use of a high pressure homogenizer, etc. ) may be performed.

When the homogenization treatment is performed, it is preferable to perform the treatment while keeping the temperature cold in order to prevent thermal deterioration of the polythiophene (A).

The concentration of the composition of the present invention may be adjusted by adjusting the blending ratio, or by concentration after blending. The method of concentration may be a method of distilling off the solvent under reduced pressure or a method of using an ultrafiltration membrane.

Since the composition of the present invention contains a conductive polymer and has excellent ink properties, it is preferably a conductive ink containing a conductive polymer.

A conductive film can be produced from the composition (or conductive ink containing a conductive polymer) of the present invention. For example, the composition (or conductive ink containing a conductive polymer) of the present invention can be coated on a support and dried to produce a conductive film on the support.

The support is not particularly limited as long as it can be coated with the composition of the present invention, and examples thereof include polymeric substrates and inorganic substrates. Examples of the polymer substrate include, but are not limited to, thermoplastic resins, nonwoven fabrics, paper, resist film substrates, and the like. Examples of thermoplastic resins include, but are not limited to, polyethylene, polypropylene, polyethylene terephthalate, polyacrylate, polycarbonate, and the like. The nonwoven fabric is not particularly limited, but examples thereof include natural fiber nonwoven fabric, synthetic fiber nonwoven fabric, glass fiber nonwoven fabric, and the like. As the paper, general cellulose-based paper may be used. Examples of inorganic substrates include, but are not limited to, glass, metal oxides such as ITO, ceramics, aluminum oxide, and tantalum oxide.

The method of applying the composition (or conductive ink containing a conductive polymer) of the present invention is not particularly limited, but examples include casting, dipping, bar coating, dispenser, roll coating, and gravure. A coating method, a flexographic printing method, a spray coating method, a spin coating method, an inkjet method, or the like can be mentioned. A bar coating method, a spin coating method, or an inkjet method is preferably used.

The drying temperature of the coating film is not particularly limited as long as it is equal to or lower than the temperature at which a uniform conductive polymer film can be obtained and the heat resistance temperature of the substrate. °C, more preferably room temperature to 220°C.

The drying atmosphere may be air, inert gas, vacuum, or reduced pressure. From the viewpoint of suppressing deterioration of the polymer film, it is preferable to be in an inert gas such as nitrogen or argon.

The film thickness of the conductive film to be obtained is not particularly limited, but is preferably in the range of 20 to 200 nm. It is more preferably 30 to 80 nm.

The conductive film of the present invention produced by the above method can be used as a conductor in an organic electronic device such as an organic electroluminescence device or an organic photoelectric light emitting device.

The conductivity of the conductive film is preferably 10 ⁻² S/cm or less ^. /cm to 10 ^-3 S/cm, more preferably 10 ^-7 to 10 ^-4 S/cm.

The conductive film obtained by drying the composition of the present invention is not particularly limited, but can be used, for example, as a hole-injecting material for blocking organic electrons or a hole-transporting material. . Therefore, the conductive film is not particularly limited, but is preferably used by being included in an organic electronic device such as an organic electroluminescence device or an organic photoelectric conversion device.

Examples relating to the present invention are shown below.

Analytical instruments and measuring methods used in this example are listed below.
[Surface resistivity measurement]
Apparatus: Loresta GP MCP-T600 manufactured by Mitsubishi Chemical Corporation
Apparatus: Hiresta UX MCP-HT8000 manufactured by Mitsubishi Chemical Corporation
[Film thickness measurement]
Device: DEKTAK XT manufactured by BRUKER
[Conductivity measurement of conductive polymer]
About 0.4 ml of the conductive polymer-containing ink of the present invention was applied to a 33 mm square non-alkaline glass plate, and then a film was formed using a MIKASA spin coater MS-A150 (condition=1000 rpm (20 seconds)). After that, it was heated on a hot plate at 200° C. for 20 minutes to obtain a conductive polymer film. It was calculated based on the following formula from the film thickness and the surface resistance value.
Conductivity [S/cm]=10 ⁴ /(Surface resistivity [Ω/□]×Film thickness [μm])
[Surface tension measurement]
Apparatus: Capillary rise method surface tensiometer DG-1 (manufactured by surface side equipment)
[Smoothness evaluation]
After applying a conductive polymer-containing composition (ink) to a glass substrate of 33 mm square each in length and width that had been washed with isopropanol and O ₃ , spin coating was performed at 1000 rpm (20 seconds) (using MIKASA's spin coater MS-A150). The state of the obtained thin film of several tens of nm (presence or absence of non-uniformity or unevenness) was visually observed.
[Viscosity measurement]
Complete type viscometer/BROOKFIELD VISCOMETER DV-1 Prime
[GPC measurement of polyacrylic acid-based water-soluble resin]
Apparatus: Build-up GPC system Column: TSKgel GMPWXL (7.8 mm ID x 30 cm) x 2 Detector: RI detector Eluent: 0.2 M-phosphate buffer (pH = 7.0) / acetonitrile = 9/1
Flow rate: 1.0ml/min
Concentration: 0.05 wt%
Injection volume: 100 μl
Column temperature: 40°C
Synthesis example 1.
Sodium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-methyl-1-propanesulfonate [represented by the following formula (5) compound].
In a nitrogen atmosphere, 4.4 g (109 mmol) of 60% sodium hydride and 400 ml of toluene were charged in a 1000 ml eggplant-shaped flask, and then (2,3-dihydrothieno[3,4-b][1,4]dioxin-2- yl) Methanol 15.2 g (88.4 ml) was added. Thereafter, the reaction solution was heated to the reflux temperature and stirred at the same temperature for 1 hour. After that, a mixture of 12.1 g (89 mmol) of 2,4-butanesultone and 100 ml of toluene was added dropwise, and the mixture was stirred at the same temperature for 2 hours. After cooling, the obtained reaction liquid was dropped into 1500 ml of acetone to reprecipitate. The obtained powder was filtered and vacuum dried to obtain 18.0 g of pale yellow powder with a yield of 62%. From NMR measurement, this is represented by the following formula (5): 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-methyl-1 - Confirmed to be sodium propane sulfonate.

1H-NMR (D ₂ O) δ (ppm); 6.67 (s, 2H), 4.54-4.60 (m, 1H), 4.45 (dd, 1H, J = 12.0, 2 .2Hz), 4.26 (dd, 1H, J = 12.0, 6.8Hz), 3.90-3.81 (m, 4H), 3.10-3.18 (m, 1H), 2 .30-2.47 (m, 1H), 1.77-1.92 (m, 1H), 1.45 (d, 3H)
13C-NMR (D ₂ O) δ (ppm); .88, 141.06.

Synthesis example 2.
Synthesis of polythiophene (A) [polymer containing structural units represented by the following formulas (6) and (7)].
3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-methyl-1 synthesized according to Synthesis Example 1 was placed in a 500 ml separable flask. - 10 g (30 mmol) of sodium propanesulfonate and 150 g of water were added. After dissolution, 2.94 g (18.1 mmol) of anhydrous iron (III) chloride was added at room temperature and stirred for 20 minutes. Thereafter, a mixed solution of 14.5 g (60.4 mmol) of sodium persulfate and 100 g of water was added dropwise while maintaining the temperature of the reaction solution at 30° C. or lower. After stirring at room temperature for 3 hours, the reaction solution was dropped into 800 g of acetone to precipitate a black Na-type polymer. Filtration and vacuum drying of the polymer gave 18.0 g of 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-methyl-1 - A crude polymer of sodium propanesulfonate was obtained.

Next, 1450 g of an aqueous solution prepared by adding water to 14.5 g of this crude polymer to prepare a 1% by weight solution is passed through a column packed with 350 ml of cation exchange resin Lewatit MonoPlus S100 (H type) (space velocity = 1.1 ) to obtain 1550 g of an H-type polymer aqueous solution. Furthermore, by purifying the aqueous polymer solution by cross-flow ultrafiltration (molecular weight cut off = 10,000, permeability = 20), a polymer containing structural units represented by the following formulas (6) and (7) was obtained. 579 g of a deep ultramarine blue aqueous solution of the combination (polythiophene (A)) was obtained.

The amount of polymer contained in the polythiophene (A) aqueous solution was 1.51% by weight. It also contained 44 ppm and 12 ppm (relative to the polymer) of iron ions and sodium ions, respectively. A thin film was prepared using the aqueous solution of this polymer, and the conductivity was measured to be 230 S/cm.

Synthesis Example 3 (Synthesis of styrenesulfonic acid/methacrylic acid copolymer (molar ratio 10/90))
A 300 ml eggplant-shaped flask was charged with 2.50 g (10.7 mmol) of sodium styrenesulfonate (manufactured by Tosoh Finechem, purity = 88.2 wt%), 10.5 g (97.2 mmol) of sodium methacrylate, and 142 g of water. After that, the mixture was stirred at room temperature under a nitrogen atmosphere until the mixture became uniform. After that, 59 mg (0.21 mmol) of 2,2′-azobis(2-methylpropionamidine) dihydrochloride was added and stirred at 80° C. for 20 hours. After cooling, the obtained reaction liquid was reprecipitated in 2 L of acetone. After filtration and drying, 12.5 g of sodium polystyrene/sodium methacrylate copolymer (molar ratio 10/90) was obtained. As a result of GPC measurement, the copolymer had a weight average molecular weight of 170,000 (Mw/Mn=1.8).

After diluting the obtained copolymer with water, it was passed through 120 ml of ion exchange resin Lewatit S108H for ion exchange to give a styrenesulfonic acid/methacrylic acid copolymer (molar ratio 10/90) (copolymer A and ) was obtained as a 2.7 wt% aqueous solution (yield = 76%, viscosity = 8.3 mPa·s (20°C)).

Synthesis Example 4 (Synthesis of styrenesulfonic acid/methacrylic acid copolymer (molar ratio 25/75))
15.5 g of sodium styrenesulfonate was obtained in the same manner as in Synthesis Example 3, except that sodium styrenesulfonate and sodium methacrylate were changed to 6.57 g (28.1 mmol) and 9.10 g (84.2 mmol), respectively. /sodium methacrylate copolymer (molar ratio 25/75) was obtained. As a result of GPC measurement, the copolymer had a weight average molecular weight of 220,000 (Mw/Mn=2.0).

By performing ion exchange treatment in the same manner as in Synthesis Example 3, 301 g of a 2.5 wt % aqueous solution of a styrenesulfonic acid/methacrylic acid copolymer (molar ratio: 25/75) (abbreviated as copolymer B) was obtained. modulus = 77%, viscosity = 9.3 mPa·s (20°C).

Example 1.
1.52 g of 20% by weight polyacrylic acid (molecular weight 250,000) aqueous solution, 2.00 g of propylene glycol n-propyl ether, 11.49 g of dimethylacetamide, and 4.44 g of ethylene glycol were added to a 30 ml sample bottle to form a uniform solution. (Solution-1) was obtained. To 19.45 g of the homogeneous solution, the polythiophene (A) obtained in Synthesis Example 2 [the polymer containing the structural units represented by the above formulas (6) and (7)] [conductivity of 230 S/cm] was added. 0.57 g of an aqueous solution containing 1.51% by weight was added and stirred overnight at room temperature to obtain a conductive polymer-containing ink (HIM01). The concentrations of polythiophene (A), polyacrylic acid-based water-soluble resin (B), ethylene glycol (C), propylene glycol n-propyl ether (D), and dimethylacetamide (E) in the obtained HIM01 were , 0.043 wt%, 1.5 wt%, 22.1 wt%, 10.0 wt%, and 57.5 wt%.

The viscosity and surface tension of HIM01 were 11.3 mPa·s and 35 mN/m, respectively.

Example 2
A conductive polymer-containing ink HIM02 was obtained in the same manner as in Example 1, except that propylene glycol was used instead of ethylene glycol. Table 1 shows the measurement results of the viscosity and surface tension of HIM02.

Example 3
A conductive polymer-containing ink HIM03 was obtained in the same manner as in Example 1, except that propylene glycol n-propyl ether was changed to ethylene glycol n-butyl ether. Table 1 shows the measurement results of the viscosity and surface tension of HIM03.

Example 4
1.52 g of 20% by weight polyacrylic acid (molecular weight 250,000) aqueous solution, 2.00 g of ethylene glycol n-butyl ether, 14.93 g of dimethylacetamide, and 1.00 g of propylene glycol were added to a 30 ml sample bottle to form a homogeneous solution ( Solution-1) was obtained. To 19.45 g of the uniform solution was added the polythiophene (A) obtained in Synthesis Example 2 [the polymer containing the structural unit represented by the formula (6) or the formula (7)] [conductivity 230 S/cm]. 0.57 g of an aqueous solution containing 1.51% by weight was added and stirred overnight at room temperature to obtain a conductive polymer-containing ink (HIM04). The concentrations of polythiophene (A), polyacrylic acid-based water-soluble resin (B), propylene glycol (C), ethylene glycol n-butyl ether (D), and dimethylacetamide (E) in the obtained HIM04 are, respectively, 0.043 wt%, 1.5 wt%, 5.0 wt%, 10.0 wt%, and 74.6 wt%.

The viscosity and surface tension of HIM04 were 6.7 mPa·s and 37 mN/m, respectively.

Example 5
A conductive polymer-containing ink HIM5 was obtained in the same manner as in Example 4 except that the amounts of ethylene glycol n-butyl ether and propylene glycol were changed to 1.00 g and 2.00 g, respectively. Table 1 shows the measurement results of the viscosity and surface tension of HIM05.

Example 6
The same operation as in Example 4 was performed except that 2.0 g of ethylene glycol n-butyl ether was changed to 1.0 g of propylene glycol n-butyl ether and the amount of propylene glycol was changed from 1.0 g to 2.0 g. A polymer-containing ink HIM06 was obtained. Table 1 shows the measurement results of the viscosity and surface tension of HIM06.

Example 7
Same as Example 4 except that ethylene glycol n-butyl ether 2.0 g was changed to diethylene glycol mono n-butyl ether 1.0 g, the amount of propylene glycol was changed from 1.0 g to 2.0 g, and dimethylacetamide was changed to diethylacetamide. A conductive polymer-containing ink HIM07 was obtained by performing the following operations. Table 1 shows the measurement results of the viscosity and surface tension of HIM07.

Example 8
A conductive polymer-containing ink HIM08 was obtained in the same manner as in Example 4 except that dimethylacetamide was changed to diethylacetamide. Table 1 shows the measurement results of the viscosity and surface tension of HIM08.

Example 9
The same operation as in Example 4 was performed except that 2.0 g of ethylene glycol n-butyl ether was changed to 1.0 g, and 14.93 g of dimethylacetamide was changed to 15.93 g of diethylacetamide. Obtained. Table 1 shows the measurement results of the viscosity and surface tension of HIM09.

Example 10
1.52 g of 20% by weight polyacrylic acid (molecular weight 250,000) aqueous solution was changed to 1.51 g of 20% by weight polyacrylic acid (molecular weight 100,000) aqueous solution, and propylene glycol was changed to ethylene glycol, A conductive polymer-containing ink HIM10 was obtained in the same manner as in Example 4 except that ethylene glycol mono-n-butyl ether was changed to propylene glycol n-butyl ether and dimethylacetamide was changed to diethylacetamide. Table 1 shows the measurement results of the viscosity and surface tension of HIM10.

Example 11
By concentrating 50 g of a 20 wt % polyacrylic acid (molecular weight: 100,000) aqueous solution under reduced pressure, 33.2 g of a 30.0 wt % polyacrylic acid aqueous solution was obtained. Except that 1.51 g of the 20% by weight polyacrylic acid (molecular weight 100,000) aqueous solution in Example 10 was changed to 1.00 g of the 30.0 weight polyacrylic acid (molecular weight 100,000) aqueous solution obtained above. Conducting the same operation as in Example 10, a conductive polymer ink HIM11 was obtained. Table 1 shows the measurement results of the viscosity and surface tension of HIM11.

Example 12
0.57 g of an aqueous solution containing 1.51% by weight of polythiophene (A) [a polymer containing a structural unit represented by the above formula (6) or the above formula (7)] [conductivity 230 S/cm] to 0.67 g Conductive polymer ink HIM12 was obtained in the same manner as in Example 4, except that dimethylacetamide was changed to diethylacetamide. Table 1 shows the measurement results of the viscosity and surface tension of HIM12.

Example 13
0.57 g of an aqueous solution containing 1.51% by weight of polythiophene (A) [a polymer containing a structural unit represented by the above formula (6) or the above formula (7)] [conductivity 230 S/cm] to 0.80 g Conductive polymer ink HIM13 was obtained in the same manner as in Example 4, except that dimethylacetamide was changed to diethylacetamide. Table 1 shows the measurement results of the viscosity and surface tension of HIM13.

Example 14
By concentrating 250 g of the aqueous solution containing 2.7% by weight of copolymer A obtained in Synthesis Example 3 under reduced pressure, 45.1 g of an aqueous solution containing 15.0% by weight of copolymer A was obtained as a viscous aqueous solution. rice field.

The procedure of Example 4 was repeated except that 1.52 g of the 20% by weight polyacrylic acid (molecular weight 250,000) aqueous solution was changed to 1.52 g of the aqueous solution containing 15.0% by weight of copolymer A obtained above. Operation was performed to obtain a conductive polymer ink HIM14. Table 1 shows the measurement results of the viscosity and surface tension of HIM14.

Example 15
By concentrating 250 g of the aqueous solution containing 2.5% by weight of copolymer B obtained in Synthesis Example 4 under reduced pressure, an aqueous solution containing 15.0% by weight of copolymer B was obtained as a viscous aqueous solution.

The procedure of Example 4 was repeated except that 1.52 g of the 20% by weight polyacrylic acid (molecular weight 250,000) aqueous solution was changed to 1.52 g of the aqueous solution containing 15.0% by weight of copolymer B obtained above. Operation was performed to obtain a conductive polymer ink HIM15. Table 1 shows the measurement results of the viscosity and surface tension of HIM15.

Example 16 (smoothness, film thickness and conductivity measurements)
For the conductive polymer-containing ink HIM01 prepared in Example 1, smoothness evaluation and conductivity measurement of the conductive polymer were performed.

As a result, as shown in Table 2, the obtained thin film had good smoothness (indicated by "○" in the table) and had a conductivity of 6.7×10 ⁻⁶ S/cm.

Examples 17-30 (smoothness, film thickness and conductivity measurements)
The conductive polymer-containing inks HIM02-15 prepared in Examples 2-15 were evaluated for smoothness and measured for the conductivity of the conductive polymer. Table 2 shows the results. In addition, all the results of smoothness evaluation were favorable.

Comparative example 1
A conductive polymer-containing ink (REF01) was obtained in the same manner as in Example 1, except that ethylene glycol mono-n-butyl ether was changed to ethanol. The concentrations of polythiophene (A), polyacrylic acid-based water-soluble resin (B), propylene glycol, ethanol, and dimethylacetamide in the obtained REF01 were 0.043% by weight, 1.5% by weight, and 22% by weight, respectively. .2 wt%, 10.0 wt%, and 57.6 wt%.

The viscosity and surface tension of REF01 were 7.7 mPa·s and 32 mN/m, respectively. However, the spin-coated film obtained from REF01 had irregularities and no smoothness.

Comparative Examples 2-3
The same operation as in Example 1 was performed except that ethylene glycol mono-n-butyl ether was changed to propylene glycol monomethyl ether or diethylene glycol monomethyl ether to obtain conductive polymer-containing inks (REF02 and REF03).

The viscosity and surface tension of REF02 were 12.7 mPa·s and 33 mN/m, respectively, and the viscosity and surface tension of REF03 were 13.0 mPa·s and 33 mPa·s, respectively. However, as in Comparative Example 1, both REF02 and REF03 had no smoothness of spin-coated films.

Example 31. (Fabrication and evaluation of element)
A glass substrate laminated with an ITO transparent electrode (anode) having a thickness of 200 nm was subjected to ultrasonic cleaning with acetone and pure water and boiling cleaning with isopropyl alcohol. Furthermore, ultraviolet ozone cleaning was performed.

The conductive polymer-containing ink HIM01 prepared in Example 1 was filtered through a filter with a pore size of 0.4 μm, applied by spin coating (700 rpm, 20 seconds), and dried at 200° C. for 30 minutes. As a result, a hole injection layer of 63 nm was deposited.

Next, after being installed in a vacuum deposition apparatus, the inside of the apparatus was evacuated by a vacuum pump until the inside of the apparatus became 1.0×10 ⁻⁴ Pa or less. Subsequently, a film of N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine (α-NPD), which is a material for the hole transport layer, was formed with a thickness of 50 nm by a vacuum evaporation method. A pore transport layer was formed. Further, a film of tris(8-quinolinolato)aluminum (Alq ₃ ) was formed with a thickness of 50 nm by a vacuum evaporation method to form a light-emitting layer and an electron-transporting layer.

Subsequently, a 1 nm LiF film and a 100 nm aluminum film were formed as a cathode to form a metal electrode. In addition, each film thickness was measured with a stylus type film thickness meter (DEKTAK).

Furthermore, in a nitrogen atmosphere, a glass plate for sealing was adhered with a UV curable resin to obtain an organic EL element for evaluation.

A current of 10 mA/cm ² was applied to the device thus produced, and the drive voltage was measured. Also, a constant current was applied, the initial luminance was set to 1000 cd/m ² , and the time until the luminance decreased to 70% of the initial luminance was evaluated as LT70. In addition, it means that durability is so favorable that the value of LT70 is large. Table 3 shows the evaluation results.

Examples 32 to 45 (Fabrication and Evaluation of Elements)
In Example 31, HIM02-15 prepared in Examples 2-15 were used instead of the conductive polymer-containing ink HIM01. LT70 was measured. Table 3 shows the evaluation results.

Comparative example 4. (Fabrication and evaluation of element)
In Example 31, a PEDOT:PSS solution (Clevios PVP AI4083 manufactured by Heraeus) was used instead of the conductive polymer-containing ink HIM01. was measured. Table 3 shows the evaluation results.

The measurement results of Examples 31 to 45 were normalized by setting the measurement value of Comparative Example 4 to 100 and displayed. The drive voltage represents the voltage required for light emission, and the lower the drive voltage, the better the industrial application. LT70 represents the lifetime of the light-emitting element, and the higher the LT70, the longer the lifetime and the better for industrial use.

Example 46 (Examination of ejection properties using an inkjet printer)
Diethylacetamide was added to each of the conductive polymer-containing inks (HIM01 to 15) prepared above, so that the solid content concentration (total concentration of component (A) and component (B)) was 1.2% by weight. to obtain an inkjet composition. Using an inkjet printer DMP-2831 manufactured by Fujifilm Dimatix, the following ejection examination was performed.

In the examination of ejection, a head cartridge with a droplet ejection volume of 10 pl was used, and the state when each of the inkjet compositions described above was continuously ejected for 15 minutes was observed. As a result, it was confirmed that all of the ink jet compositions could be discharged continuously without any observation of ejection failure or ejection disturbance during ejection.

In addition, the ejection stability after the suspension was also evaluated. The ejection stability after resting was evaluated by performing ejection for 5 minutes under the above conditions, and observing the state when ejection was restarted under the same conditions after resting overnight. As a result, it was confirmed that all of the ink-jet compositions could be ejected simultaneously with the instruction to eject droplets without any problems.

The conductive polymer-containing ink of the present invention can form a polymer film having good hole transportability (injectability) and durability. Durable devices with improved lifetime can be made. In particular, in organic electroluminescence devices, not only fluorescent organic EL devices but also phosphorescent organic EL devices with low power consumption can be provided.

This conductive polymer-containing ink has good wettability to polymeric substrates other than substrates such as glass and metal, and can be applied without repelling or spots. Therefore, it can be used as a conductive coating agent (antistatic agent) for various substrates, a solid electrolyte (cathode material) for solid electrolytic capacitors, and the like. Coated articles made of a polymer substrate coated with this conductive polymer film can also be used as antistatic films, solid electrolytes for solid electrolytic capacitors, and separators for wound aluminum electrolytic capacitors. In addition, electrochromic devices, transparent electrodes, transparent conductive films, thermoelectric conversion materials, chemical sensors, actuators, electromagnetic shielding materials, metal oxide surface coating materials such as ITO, which is an electrode material for organic EL and solar cells, etc. Applications are also expected.

Claims (14)

Polythiophene (A) containing at least one structural unit selected from the group consisting of a structural unit represented by the following formula (1) and a structural unit represented by the following formula (2), a polyacrylic acid-based water-soluble resin (B) ), glycol (C), glycol ether (D) represented by the following general formula (3), and at least selected from the group consisting of dimethylformamide, dimethylacetamide, diethylacetamide, N-methylpyrrolidone, and N-ethylpyrrolidone A composition containing one aprotic polar solvent (E), wherein the contents of (A), (B), (C) and (D) are each 0.005 to 1.0 weight %, 0.1 to 10% by weight, 0.01 to 30% by weight, and 0.01 to 30% by weight, the content of (E) is 50 to 85% by weight, and (C), A composition characterized in that the sum of (D) and (E) is 60-99% by weight, and the weight ratio (weight/weight) represented by (B)/(A) is 15-40 .

[In Formula (1), M represents a hydrogen ion, an alkali metal ion, a conjugate acid of an amine compound, or a quaternary ammonium cation. In formulas (1) and (2), R ¹ is a hydrogen atom, a methyl group, an ethyl group, a linear or branched alkyl group having 3 to 6 carbon atoms, or a substituted alkyl group having 1 to 6 carbon atoms. represents a group or a fluorine atom, m represents an integer of 1 to 10, and n represents 0 or 1. ]

(In the formula, R ² represents a linear or branched alkyl group having 3 to 6 carbon atoms; R ³ and R ⁴ each independently represent a hydrogen atom or a methyl group; p represents 1 or 2; .) The composition of claim 1, wherein the sum of (C), (D) and (E) is 70-98% by weight. The composition of claim 1, wherein the sum of (C), (D) and (E) is 80-98% by weight. Glycol (C) is selected from the group consisting of ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butylene glycol, 2,3-butanediol, and 2-methyl-2,4-pentanediol 4. A composition according to any one of claims 1 to 3 , characterized in that it is at least one. Composition according to any one of claims 1 to 4 , characterized in that the content of glycol (C) is between 0.1 and 15% by weight. Glycol ether (D) is ethylene glycol mono n-propyl ether, ethylene glycol mono n-butyl ether, propylene glycol mono n-propyl ether, propylene glycol mono n-butyl ether, diethylene glycol mono n-propyl ether, diethylene glycol mono n-butyl ether, 6. The composition according to any one of claims 1 to 5 , which is dipropylene glycol mono-n-propyl ether or dipropylene glycol mono-n-butyl ether. Composition according to any one of claims 1 to 6 , characterized in that the content of glycol ether (D) is from 0.1 to 15% by weight. The polyacrylic acid-based water-soluble resin (B) is polyacrylic acid, polymethacrylic acid, poly(acrylic acid-styrenesulfonic acid) copolymer, or poly(methacrylic acid-styrenesulfonic acid) copolymer. A composition according to any one of claims 1 to 7 . 9. The composition according to any one of claims 1 to 8 , wherein the polyacrylic acid-based water-soluble resin (B) has a weight average molecular weight of 1,000 to 500,000. 10. The composition according to any one of claims 1 to 9 , further comprising water. The composition according to any one of claims 1 to 10 , which has a viscosity at 20°C of 20 mPa·s or less and a surface tension of 20 to 40 mN/m. A conductive polymer-containing ink comprising the composition according to any one of claims 1 to 11 . A method for producing a film, comprising applying the composition according to any one of claims 1 to 11 and then drying the composition. 14. An organic electronic device, either an organic electroluminescence device or an organic photoelectric conversion device, comprising a film obtained by the manufacturing method according to claim 13 .