JP2009120631A - Inkjet ink and method for producing electroconductive pattern - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet ink excellent in satellite resistance obtained by adjusting the amount of a static electric charge by adding an ionic liquid to the inkjet ink dissolving an organic semiconductor compound, and a method for producing an electroconductive pattern by using the same. <P>SOLUTION: This inkjet ink used for forming a pattern image by ejecting it from an inkjet-recording device equipped with a pressure-impressing means and an electric field-impressing means is characterized by containing the organic semiconductor compound, an organic solvent having a specific permittivity of 10 or less and at least one selected from specific 5 kinds of ionic liquids. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an inkjet ink in which an organic semiconductor compound is dissolved and a method for producing a conductive pattern using the same.

  In recent years, research on organic electronic devices using organic materials has been active. By making organic materials into thin films and applying them to devices, it is expected to realize organic electronic devices that can be manufactured at a low temperature and a low cost process, have excellent portability, and are inexpensive.

  In an organic transistor which is a kind of such an organic electronic device, a semiconductor material used for a channel is an aggregate of organic molecules (organic semiconductor material) and is covalently bonded only within the molecule. Therefore, as a whole, it is a relatively weak bond with respect to crystalline silicon. Therefore, it can be expected that the manufacturing process (particularly the crystallization step) will be performed at a low temperature. Organic semiconductor materials are highly flexible and can be reduced in weight. Therefore, by using an organic transistor, there is a possibility of providing a device with excellent portability. Specifically, the organic transistor may be suitable as a component of a paper-like display or a liquid crystal display. One effective method for realizing a low-temperature manufacturing process is a method for manufacturing an organic transistor using an inkjet method.

  As this ink jet method, various discharge methods such as a piezo method and a thermal method are known. Particularly when discharging a small ink droplet, if the initial speed at the time of discharge is increased, the liquid may be discharged at the time of discharge depending on the applied conditions. Drops may be stretched and the back end may split. The divided fine droplets are called “satellite”, and cause a problem that they adhere to a position that is later than the main droplet and deviates from a desired landing position, or drifts in the print space without adhering. Therefore, when such a satellite is generated, the formed image is deteriorated, and a method for preventing the generation of the satellite has been proposed (for example, see Patent Document 1).

On the other hand, an inkjet ink containing an ionic liquid has been proposed as an inkjet ink. For example, even if an electric charge is applied on the recording medium, the charging of the ink droplet is neutralized by the addition of the ionic liquid, so the repulsion between the recording medium and the ink droplet is eliminated, and the recording accuracy is improved. A method has been proposed (see, for example, Patent Document 2).
Patent Document 2 discloses that the positional accuracy is improved by setting the relationship between the polarity of the ink droplet and the polarity of the substrate to the opposite polarity. When charged to a polarity, the charge of the ink is excessively combined with the opposite polarity, and the positional accuracy is certainly improved, but the charge balance near the nozzles in the head deteriorates, and the ink droplets from the head nozzles deteriorate. It has been found that there is a problem that the injection stability is not sufficient. In other words, ink that is extremely charged with positive or negative charges leaves charges in the vicinity of the nozzle, which causes problems such as ejection failure and satellite generation.

Further, Patent Document 3 reports that by adding an ionic liquid to ink, the ionic liquid fills the gaps between the conductive particles, and the conductivity of the formed conductive film is improved. However, in Patent Document 3, there is no description regarding the ejection stability of the inkjet ink.
JP 2004-216877 A JP 2006-206686 A JP 2006-335995 A

  The present invention has been made in view of the above problems, and an object of the present invention is to add an ionic liquid to an inkjet ink in which an organic semiconductor compound is dissolved, thereby adjusting an amount of charge and an inkjet ink having excellent satellite resistance. An object of the present invention is to provide a conductive pattern manufacturing method using the same.

  The above object of the present invention is achieved by the following configurations.

  1. An ink-jet ink used for forming a pattern image by being ejected by an ink-jet recording apparatus having a pressure applying means and an electric field applying means, comprising an organic semiconductor compound, an organic solvent having a relative dielectric constant of 10 or less, and the following general formula An ink-jet ink comprising at least one selected from ionic liquids represented by (1) to (5).

[Wherein, Q ₁ represents an atomic group that forms a 5- or 6-membered aromatic cation with a nitrogen atom. R ₁ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted alkenyl group. X ⁻ represents an anion. ]

[Wherein, A ₁ represents a nitrogen atom or a phosphorus atom. R _{2 to} R ₅ each independently represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted alkenyl group. X ⁻ represents an anion. ]

[Wherein, R _{6 to} R ₁₁ each independently represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted alkenyl group. X ⁻ represents an anion. ]
General formula (4)
^{_{P + R 12 R 13 R 14}} R 15 · X -
[Wherein, R _{12 to} R ₁₅ each independently represents a substituted or unsubstituted alkyl group, aryl group, heterocyclic group or aralkyl group, which may be the same or different. X ⁻ represents an anion. ]

[Wherein, X and Y each represents an alkyl group having 1 to 4 carbon atoms, and may be the same or different. k and i each represents 0 or a positive integer of 1 to 4, n and m each represents a positive integer of 3 to 7, and A represents an acid component. ]
2. 2. The inkjet ink as described in 1 above, wherein the ionic liquid represented by the general formulas (1) to (5) has 10 to 20 carbon atoms.

  3. 3. The ink-jet ink according to 1 or 2, wherein the organic semiconductor compound is 6,13-bistriisopropylsilylethynylpentacene or 1,3,6-N-sulfinylacetamidopentacene.

  4). 4. The inkjet ink according to any one of 1 to 3, wherein the organic solvent having a relative dielectric constant of 10 or less has a boiling point of 150 ° C. or higher and 250 ° C. or lower.

  5. A conductive pattern production method for producing a conductive pattern by ejecting the inkjet ink according to any one of items 1 to 4 from an inkjet recording apparatus, wherein the inkjet recording apparatus includes a nozzle plate having ejection holes. And a pressure chamber communicating with the discharge hole, a pressure generating element for causing a pressure fluctuation in the liquid in the pressure chamber, a voltage applying means for applying a voltage to the pressure generating element, and an electric field applying means using an electrostatic force. A conductive pattern manufacturing method.

  According to the present invention, by adding an ionic liquid to an inkjet ink in which an organic semiconductor compound is dissolved, the charge amount is adjusted, and an inkjet ink having excellent satellite resistance and a conductive pattern manufacturing method using the inkjet ink are provided. did it.

  Hereinafter, the best mode for carrying out the present invention will be described in detail.

  The ink-jet ink of the present invention comprises an organic semiconductor compound, an organic solvent having a relative dielectric constant of 10 or less, and an ionic liquid represented by the general formulas (1) to (5).

  As an ink jet method for stably discharging minute ink droplets, a voltage is applied to a nozzle plate having discharge holes, a pressure chamber communicating with the discharge holes, a pressure generating element that causes pressure fluctuations in the liquid in the pressure chamber, and a pressure generating element. An ink jet recording apparatus having a voltage applying means and an electric field applying means using an electrostatic force is known. In the ink jet recording apparatus of the discharge method using such voltage applying means and electric field applying means, the polarity and electric conductivity of the ink jet ink containing the organic semiconductor compound and the organic solvent satisfying a relative dielectric constant of 10 or less are obtained. In particular, in the discharge method using an electric field application means that uses electrostatic force, the charge amount of the droplets cannot be controlled well, and satellites and landing position shifts occur. There is.

  As a result of intensive investigations on the above problems, the present inventors have found that the above-described general formulas (1) to (5) are applied to an inkjet ink containing an organic semiconductor compound and an organic solvent having a relative dielectric constant of 10 or less. The charge amount of the ink-jet ink can be controlled by coexisting at least one selected from ionic liquids represented by the formula, and as a result, the ink jet having an ejection system to which an electric field applying means utilizing electrostatic force is applied. It has been found that the generation of satellites can be reduced even when printing is performed from a recording apparatus, and the present invention has been achieved.

  The details of the present invention will be further described below.

<Inkjet ink>
The inkjet ink of the present invention contains at least an organic semiconductor compound, an organic solvent having a relative dielectric constant of 10 or less, and an ionic liquid represented by the general formulas (1) to (5).

[Organic semiconductor compound]
The organic semiconductor compound according to the present invention refers to an organic material exhibiting semiconductivity.

  As an organic semiconductor compound applicable to the inkjet ink of the present invention, any organic compound may be selected as long as it functions as a semiconductor. Examples of organic semiconductor compounds include acenes such as pentacene and tetracene disclosed in JP-A-5-55568, phthalocyanines including lead phthalocyanine disclosed in JP-A-4-167561, and the like. Disclosure in porphyrins such as benzoporphyrin disclosed in Kaikai 2004-319982 and other low molecular weight compounds such as perylene, its tetracarboxylic acid derivatives, and tetrathiafulvalene, and in JP-A-8-264805 Aromatic oligomers typically represented by thiophene hexamers called α-thienyl or sexithiophene, and conjugated polymers such as polythiophene, polythienylene vinylene, poly-p-phenylene vinylene (many of these are “advanced”・ Materia "(Advanced Material) magazine in 2002, has been described in No. 2, page 99) is generally known. Among these, when a low molecular weight compound is used as the organic semiconductor material, the effect of the present invention is more exhibited. In particular, when a low molecular weight organic semiconductor material having a weight average molecular weight of 5000 or less is used, the organic thin film transistor is driven with high mobility. It is more preferable in obtaining.

  Among the organic semiconductor compounds described above, examples of the low molecular weight compound include condensed polycyclic compounds represented by pyrene, coronene, obalen and the like, derivatives thereof, anthracene, pentacene and the like and derivatives thereof (acenes), rubrene and the derivatives thereof, and the like. Preferred examples include condensed polycyclic aromatic compounds containing a hetero atom typified by hydrocarbons, benzodithiophene, anthradithiophene and the like and derivatives thereof, and thiophene oligomers. Examples of pentacenes include substituents described in International Publication No. 03/16599, International Publication No. 03/28125, US Pat. No. 6,690,029, Japanese Patent Application Laid-Open No. 2004-107216, and the like. A pentacene derivative described in U.S. Patent Application Publication No. 2003/136964 and the like; Amer. Chem. Soc. , Vol127. Examples include acenes and derivatives thereof described in No. 14.4986 and the like.

  In the present invention, it is particularly preferable to use 6,13-bistriisopropylsilylethynylpentacene or 1,3,6-N-sulfinylacetamidopentacene from the viewpoint of semiconductor characteristics.

[Organic solvent]
The inkjet ink of the present invention is characterized by containing an organic semiconductor compound and an organic solvent having a relative dielectric constant of 10 or less together with the ionic liquid represented by the general formulas (1) to (5).

  The organic solvent having a relative dielectric constant of 10 or less according to the present invention is not particularly limited as long as the relative dielectric constant is 10 or less. For example, hydrocarbon-based, alcohol-based, ether-based, ester-based, ketone-based, glycol ether It is appropriately selected from a high range organic solvent such as a system according to the organic semiconductor compound. As the organic solvent according to the present invention, it is more preferable to use an aromatic hydrocarbon compound such as toluene, xylene, naphthalene, tetralin, and anisole, particularly from the viewpoint of solubility of the organic semiconductor compound. There is no particular lower limit for the relative dielectric constant, but it is preferably 0.1 or more.

  The relative dielectric constant referred to in the present invention is a relative dielectric constant with respect to vacuum, and can be measured with a commercially available measuring device such as a dielectric constant measuring device HP E5050A HEWRET PACKARD according to ASTM-150. The values are described in “Chemical Handbook 4th revised edition (II)” Maruzen Co., Ltd., “Solvent Handbook 1st edition” (Kodansha Scientific), etc., which can be referred to.

  In the organic solvent having a relative dielectric constant of 10 or less according to the present invention, the boiling point is preferably 150 ° C. or more and 250 ° C. or less.

Examples of the organic solvent having a relative dielectric constant of 10 or less and a boiling point of 150 ° C. or higher and 250 ° C. or lower according to the present invention include:
Examples of the hydrocarbon-based organic solvent include decane (ε: 2.0, BP: 174 ° C.), tetralin (ε: 2.7, BP: 208 ° C.), dodecane (ε: 2.0, BP: 216 ° C.), Nonane (ε: 2.0, BP: 150 ° C.), methylene (ε: 0.1, BP: 165 ° C.), p-chlorotoluene (ε: 6.2, BP: 162 ° C.), dichlorobutane (ε: 8.9, BP: 155 ° C),
Examples of alcohol organic solvents include 2-ethylhexanol (ε: 3.4, BP: 185 ° C.), 2-heptanol (ε: 9.2, BP: 160 ° C.), and the like.
Examples of the ether organic solvent include anisole (ε: 4.3, BP: 154 ° C.), ethyl benzyl ether (ε: 3.9, BP: 186 ° C.), diisoamyl ether (ε: 2.8, BP: 173). ° C), 1,8-cineole (ε: 4.5, BP: 176 ° C), etc.
Examples of the ester organic solvent include ethyl benzoate (ε: 6.0, BP: 213 ° C.), methyl benzoate (ε: 6.6, BP: 199 ° C.), isoamyl isovalerate (ε: 3.6, BP: 194 ° C.), benzyl acetate (ε: 5.1, BP: 215 ° C.), diethyl oxalate (ε: 8.3, BP: 189 ° C.), ethyl stearate (ε: 3.0, BP: 200) ° C), isoamyl propionate (ε: 4.7, BP: 161 ° C), diethyl malonate (ε: 7.9, BP: 199 ° C), dimethyl malonate (ε: 9.9, BP: 183 ° C) , Isoamyl butyrate (ε: 4.2, BP: 185 ° C),
Can be mentioned. In the parentheses, ε represents a relative dielectric constant, and BP represents a boiling point.

  Examples of glycol ether organic solvents include ethylene glycol monoalkyl ethers, diethylene glycol monoalkyl ethers, diethylene glycol dialkyl ethers, dipropylene glycol monoalkyl ethers, dipropylene glycol dialkyl ethers, and the like. However, the present invention is not limited to these.

  In the inkjet ink of the present invention, if the boiling point of the organic solvent is 150 ° C. or higher, drying of the organic solvent in the vicinity of the nozzle (meniscus portion) is difficult to occur, and ink immediately after the change in ink physical properties in the nozzle or immediately after the discharge is stopped. Decapping due to a delay in the discharge speed of droplets is less likely to occur. Moreover, if the boiling point of the organic solvent is 250 ° C. or less, an appropriate evaporation rate of the organic solvent after drawing can be obtained.

[Ionic liquids represented by general formulas (1) to (5)]
The inkjet ink of the present invention contains at least one ionic liquid represented by the general formulas (1) to (5) together with the above-described organic semiconductor compound and the organic solvent having a relative dielectric constant of 10 or less. It is characterized by.

  Hereinafter, details of the ionic liquids represented by the general formulas (1) to (5) will be sequentially described.

  First, the ionic liquid represented by the general formulas (1) to (3) will be described.

In the general formula (1), Q ₁ represents an atomic group that forms a 5- or 6-membered aromatic cation with a nitrogen atom. Q ₁ is preferably composed of an atom selected from the group consisting of a carbon atom, a hydrogen atom, a nitrogen atom, an oxygen atom and a sulfur atom. The 5-membered ring formed by Q ₁ is preferably an oxazole ring, thiazole ring, imidazole ring, pyrazole ring, isoxazole ring, thiadiazole ring, oxadiazole ring, triazole ring, indole ring or pyrrole ring, A thiazole ring or an imidazole ring is more preferable, and an oxazole ring or an imidazole ring is particularly preferable. The 6-membered ring formed by Q ₁ is preferably a pyridine ring, pyrimidine ring, pyridazine ring, pyrazine ring or triazine ring, and particularly preferably a pyridine ring.

In the general formula (2), A ₁ represents a nitrogen atom or a phosphorus atom.

In the general formulas (1), (2) and (3), R _{1 to} R ₁₁ are each independently a substituted or unsubstituted alkyl group (preferably having 1 to 24 carbon atoms, and may be linear. It may be branched or cyclic, for example, methyl, ethyl, propyl, isopropyl, pentyl, hexyl, octyl, 2-ethylhexyl, t-octyl, decyl Group, dodecyl group, tetradecyl group, 2-hexyldecyl group, octadecyl group, cyclohexyl group, cyclopentyl group, or the like, or a substituted or unsubstituted alkenyl group (preferably having 2 to 24 carbon atoms, being linear) Or may be branched, for example, vinyl group, allyl group, etc.). R _{1 to} R ₁₁ are each independently more preferably an alkyl group having 2 to 18 carbon atoms or an alkenyl group having 2 to 18 carbon atoms, and particularly preferably an alkyl group having 2 to 6 carbon atoms.

Two or more of R _{2 to} R ₅ in the general formula (2) may be connected to each other to form a non-aromatic ring containing A _1, and among R _{6 to} R ₁₁ in the general formula (3) Two or more may be connected to each other to form a ring.

Q ₁ and R _{1 to} R ₁₁ may each have a substituent. Preferred examples of this substituent include halogen atoms (eg, F, Cl, Br, I, etc.), cyano groups, alkoxy groups (eg, methoxy group, ethoxy group, methoxyethoxy group, methoxyethoxyethoxy group, etc.), aryloxy Group (for example, phenoxy group, etc.), alkylthio group (for example, methylthio group, ethylthio group, etc.), alkoxycarbonyl group (for example, ethoxycarbonyl group, etc.), carbonate group (for example, ethoxycarbonyloxy group, etc.), acyl group (for example) For example, acetyl group, propionyl group, benzoyl group, etc.), sulfonyl group (eg, methanesulfonyl group, benzenesulfonyl group, etc.), acyloxy group (eg, acetoxy group, benzoyloxy group, etc.), sulfonyloxy group (eg, methanesulfonyl group) Oxy group, toluenesulfonylo Si group etc.), phosphonyl group (eg diethylphosphonyl group etc.), amide group (eg acetylamino group, benzoylamino group etc.), carbamoyl group (eg N, N-dimethylcarbamoyl group etc.), alkyl group ( For example, methyl group, ethyl group, propyl group, isopropyl group, cyclopropyl group, butyl group, 2-carboxyethyl group, benzyl group, etc.), aryl group (for example, phenyl group, toluyl group, etc.), heterocyclic group (for example, , Pyridyl group, imidazolyl group, furanyl group and the like), alkenyl group (for example, vinyl group, 1-propenyl group and the like), silyl group, silyloxy group and the like.

The compounds represented by the general formulas (1), (2) and (3) may form a multimer via Q ₁ and any _one of R _{1 to} R ₁₁ .

In the general formulas (1), (2) and (3), X ⁻ represents an anion. Preferred examples of X ⁻ include, for example, halide ions (for example, I ⁻ , Cl ⁻ , Br ⁻ etc.), SCN ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , ClO ₄ ⁻ , (CF ₃ SO ₂ ) ₂ N _{^{-, (CF 3 CF 2 SO}} 2) 2 N -, CH 3 SO 3 -, CF 3 SO 3 -, CF 3 COO -, Ph 4 B -, (CF 3 SO 2) 3 C - , and the like. X ^- is _{^{I -, SCN -, CF 3}} SO 3 -, CF 3 COO -, (CF 3 SO 2) 2 N - or BF ₄ ^- and more preferable.

  Specific examples of the compounds represented by the general formulas (1) to (3) according to the present invention are shown below, but the present invention is not limited to these exemplified compounds.

  Of the exemplified compounds listed above, compounds preferably used are exemplified compounds 6-3, 18-3, 21-3, 30-3, 31-3, and 33-3.

  The compounds represented by the general formulas (1) to (3) according to the present invention may be used alone or in combination of two or more.

  Next, the ionic liquid represented by the general formula (4) will be described.

In the general formula (4), R _{12 to} R ₁₅ are each independently a hydrogen atom, a saturated or unsaturated alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, or 6 to 6 carbon atoms. 10 aryl groups or aralkyl groups having 7 to 11 carbon atoms, R ₁₆ —X— (R ₁₇ —Y—) _n — (wherein R ₁₆ is an alkyl group having 4 or less carbon atoms, and R ₁₇ is 4 or less carbon atoms) Represents an oxygen atom or a sulfur atom, and n represents an integer of 0 to 10, and these groups optionally have a substituent.

Specific examples of R _{12 to} R ₁₅ include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, pentyl, hexyl, heptyl, octyl, A linear or branched alkyl group such as nonyl and decyl; a cycloalkyl group such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl; unsubstituted or halogen atom (eg, F, Cl, Br, I ), Hydroxyl group, lower alkoxy group (for example, methoxy, ethoxy, propoxy, butoxy), carboxyl group, acetyl group, propanoyl group, thiol group, lower alkylthio group (for example, methylthio, ethylthio, propylthio, butylthio), amino group, lower group Alkylamino group, di-lower alkyl An aryl group such as phenyl, naphthyl, toluyl and xylyl having 1 to 3 substituents such as a ruamino group, and an aralkyl group such as benzyl can be exemplified.

Specific examples of R ₁₆ include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, and the like. As R ₁₇ , methylene, Examples thereof include alkylene groups such as ethylene, propylene, and butylene.

By X ^- it may be any compound as long as anion as an anion species represented. Specific examples include (FSO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , CH ₃ SO ₄ ⁻ , Br ⁻ , Cl ⁻ , OH ⁻ , NO ₃ ⁻ , PF ₆ ⁻ , BF ₄ ⁻ , CH ₃ —Ph—SO ₃ ⁻ , CF ₃ SO ₃ ⁻ , C ₈ F ₁₇ SO ₃ ⁻ , C ₄ H ₉ SO ₃ ⁻ , CH ₃ OSO ₃ ⁻ , C ₈ H ₁₇ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₃ C ⁻ , HSCN ⁻ , CH ₃ COO ⁻ , C ₈ H ₁₇ COO ⁻ , (CN) ₂ N ⁻ .

  Next, the ionic liquid represented by the general formula (5) will be described.

  In the general formula (5), X and Y each represent an alkyl group having 1 to 4 carbon atoms, which may be the same or different, and k and i are each a positive integer of 0 or 1 to 4 , N and m each represent a positive integer of 3 to 7.

  In the general formula (5), when the number of carbon atoms of X and Y is 5 or more, k and i are 5 or more, or n and m are 8 or more, the ionic conductivity of the spiroammonium compound salt is preferably decreased. Absent.

  In the general formula (5), examples of the cation of the spiro ammonium compound salt include spiro- (1,1 ′)-biazacyclobutyl ion, azacyclopentane-1-spiro-1′-azacyclobutyl ion, and aza. Cyclohexane-1-spiro-1′-azacyclobutyl ion, azacycloheptane-1-spiro-1′-azacyclobutyl ion, azacyclooctane-1-spiro-1′-azacyclobutyl ion, spiro- (1 , 1 ')-biazacyclopentyl ion, azacyclohexane-1-spiro-1'-azacyclopentyl ion, azacycloheptane-1-spiro-1'-azacyclopentyl ion, azacyclooctane-1-spiro-1'- Azacyclopentyl ion, spiro- (1,1 ′)-biazacyclohexyl ion, a Cycloheptane-1-spiro-1′-azacyclohexyl ion, azacyclooctane-1-spiro-1′-azacyclohexyl ion, spiro- (1,1 ′)-biazacycloheptyl ion, azacyclooctane-1- Examples include spiro-1'-azacycloheptyl ion and spiro- (1,1 ')-biazacyclooctyl ion.

In the general formula (5), A represents an acid component. For example, perchlorate ion (ClO ₄ ⁻ ), fluorine ion (F ⁻ ), chlorine ion (Cl ⁻ ), bromine ion (Br ⁻ ), iodine ion ( I ⁻ ), hexafluorophosphate ion (PF ₆ ⁻ ), hexafluoroantimonate ion (SbF ₆ ⁻ ), tetrafluoroborate ion (BF ₄ ⁻ ), trifluoromethanesulfonate ion (CF ₃ SO ₃ ⁻ ), Trifluoroacetate ion (CF ₃ CO ₂ ⁻ ), bistrifluoromethanesulfonylimide ion ((CF ₃ SO ₂ ) ₂ N ⁻ ), perfluorobutane sulfonate ion (C ₄ F ₉ SO ₃ ⁻ ), tristrifluoromethanesulfonylmethy Doion ((CF ₃ SO ₂ ) ₃ C ⁻ ), dicyanamide ion ((CN) ₂ N ⁻ ) and the like.

  The spiro ammonium compound salt represented by the general formula (5) according to the present invention is obtained by the following production method.

  First, dibromoalkane brominated at both ends is allowed to act on azacycloalkane in the presence of potassium carbonate in an isopropyl alcohol solvent to obtain spiroammonium bromide, and then the bromide is desalted by electrodialysis in water or alcohol. To obtain a spiro ammonium hydroxide solution. Next, the resulting spiroammonium hydroxide solution was added with an equimolar amount of an acid component corresponding to A in the general formula (5), neutralized, and then dehydrated under reduced pressure. Spiroammonium compound salts can be obtained.

  The ionic liquid represented by the general formulas (1) to (5) according to the present invention preferably has a total carbon number of 10 or more and 20 or less. An ionic liquid having a total carbon number of 10 or more can impart solubility to a hydrophobic organic solvent used to dissolve the organic semiconductor compound, and if it is 20 or less, at an appropriate melting point at room temperature. The liquid state can be maintained, which is preferable from the viewpoint of easy handling.

  In addition, when an electroconductive pattern is formed using the ink-jet ink of the present invention to produce, for example, an organic TFT or the like, considering its reliability, trifluoromethylsulfonyl group, bis (trifluoromethyl) are considered as anion species. It is more preferable to use a sulfonyl) imide group or a p-toluenesulfonate group.

  The addition amount of the ionic liquid according to the present invention is preferably 1% by mass or more and 10% by mass or less with respect to the total mass of the organic semiconductor compound contained in the ink-jet ink from the viewpoint of ejection properties and semiconductor characteristics after pattern drawing. .

[Physical properties of inkjet ink]
The inkjet ink of the present invention preferably has a viscosity of 0.9 mPa · s or more and 20 mPa · s or less. Furthermore, 2 mPa · s or more and 10 mPa · s or less are preferable from the viewpoint of injection stability, and 3 mPa · s or more and 7 mPa · s or less are most preferable. The ink viscosity (mPa · s) referred to in the present invention is a viscosity value measured at 25 ° C. and can be determined using a conventionally known viscometer.

  In the inkjet ink of the present invention, the surface tension is preferably 20 mN / m or more and 60 mN / m or less. Furthermore, 30 mN / m or more and 50 mN / m or less are preferable from the viewpoint of injection stability. The surface tension (mN / m) of the ink referred to in the present invention is a surface tension value measured at 25 ° C., and the measuring method is described in general interface chemistry, colloid chemistry reference books, etc. New Experimental Chemistry Lecture Volume 18 (Interface and Colloid), The Chemical Society of Japan, published by Maruzen Co., Ltd. 68-117 can be referred to.

  The electrical conductivity of the inkjet ink of the present invention is preferably 0.1 μS / cm or more and 1000 μS / cm or less at 25 ° C., but more preferably 1 μS / cm or more and 500 μS / cm or less from the viewpoint of drawability. The electric conductivity of the ink can be easily measured according to a method as described in the method described in JIS K 0130 (1995).

<< Method for producing conductive pattern >>
In the present invention, using the organic semiconductor compound described above, the organic solvent having a relative dielectric constant of 10 or less, and the inkjet ink of the present invention containing the ionic liquid according to the present invention, pressure applying means and electric field applying means One of the features is that a pattern image is formed by discharging with an inkjet recording apparatus including

  The ink jet recording apparatus provided with the pressure applying means and the electric field applying means according to the present invention will be described in detail.

  In general, in order to draw a fine line width pattern required in an electronic circuit or the like with high definition, it is necessary to further refine the ink droplets ejected from the ink jet recording apparatus.

  However, electro-mechanical conversion methods (eg, single cavity type, double cavity type, bender type, piston type, shear mode type, shared wall type, etc.) and electro-thermal conversion methods (eg, thermal ink jet type, bubble jet type) When a very small ink droplet is ejected using only (registered trademark type) output means, the kinetic energy imparted to the ink droplet ejected from the nozzle is proportional to the cube of the radius of the ink droplet Therefore, the microdroplet cannot secure sufficient kinetic energy enough to withstand air resistance, and is subject to disturbance due to air convection, making accurate landing difficult. Furthermore, as the ink droplet becomes finer, the effect of surface tension increases, so the vapor pressure of the droplet increases and the amount of evaporation increases. For this reason, fine droplets cause a significant loss of mass during flight, and there is a problem that it is difficult to maintain the shape of the droplets upon landing. As described above, increasing the accuracy of the landing position is a problem that contradicts the miniaturization of ink droplets, and has an obstacle to realizing these two simultaneously.

  In the present invention, as a method for solving the above problems, an injection method using a pressure applying means and an electric field applying means is applied.

  In this ejection method, a nozzle having an ejection port having an inner diameter of 0.1 to 100 μm is used, and an arbitrary waveform voltage is applied to the inkjet ink of the present invention (hereinafter also referred to as conductive ink). In this method, the ink droplets are discharged from the discharge port to the ink receiving substrate having a resin layer by charging.

  That is, in this ejection method, the inner diameter of the nozzle outlet is 0.1 to 100 μm and the electric field strength distribution is narrow, so that an arbitrary waveform voltage is applied to the conductive ink supplied into the nozzle. Thus, the electric field can be concentrated. As a result, the formed ink droplets can be made minute and the shape can be stabilized. Accordingly, it is possible to form an ink droplet pattern composed of a plurality of ink droplets, for example, less than 1 pl (picoliter), on the surface of the resin layer. In addition, since the electric field strength distribution is narrow, the total applied voltage applied to the conductive ink in the nozzle can be reduced. The ink droplet is accelerated by an electrostatic force acting between the electric field and the electric charge immediately after being ejected from the nozzle. However, since the electric field rapidly decreases when the ink droplet moves away from the nozzle, the ink droplet is then decelerated by air resistance. However, the ink droplets, which are minute droplets and the electric field is concentrated, are accelerated by mirror image force as they approach the resin layer. By balancing the deceleration by the air resistance and the acceleration by the mirror image force, it is possible to stably fly the fine droplets and improve the landing accuracy.

  FIG. 1 is a schematic cross-sectional view showing an example of a conductive ink discharge apparatus using a pressure applying unit and an electric field applying unit that can be preferably applied to the present invention.

  In FIG. 1, a conductive ink discharge device 120 includes a nozzle 121 having an ultrafine diameter that discharges a droplet of conductive ink that can be charged from a tip portion toward an ink receiving substrate K having a resin layer. A counter electrode 123 that is positioned on the surface facing the tip and supports the ink receiving substrate K on the facing surface; a conductive ink supply unit that supplies conductive ink to the flow path 122 in the nozzle 121; Ejection voltage application means (voltage application means) 125 for applying an ejection voltage having an arbitrary waveform to the conductive ink in the nozzle 121 is provided. The nozzle 121 and a part of the conductive ink supply unit and a part of the discharge voltage application unit 125 are formed integrally with the nozzle plate 126.

  The nozzle 121 is suspended from the lower surface layer 126c of the nozzle plate 126 and is formed integrally with the lower surface layer 126c. The tip of the nozzle 121 is directed to the counter electrode 123. Inside the nozzle 121, an in-nozzle flow path 122 that penetrates from the tip portion along the center line is formed.

  The nozzle 121 is formed with an ultrafine diameter by an electrical insulator such as glass. As specific examples of the dimensions of each part of the nozzle 121, the internal diameter of the nozzle flow path 122 is 1 μm, the external diameter at the tip of the nozzle 121 is 2 μm, the root of the nozzle 121, that is, the diameter of the upper end is 5 μm, and the nozzle The height of 121 is set to 100 μm. The shape of the nozzle 121 is formed in a truncated cone shape that is close to a conical shape. The entire nozzle 121 is formed of an insulating resin material together with the lower surface layer 126c of the nozzle plate 126.

  The dimensions of the nozzle 121 are not limited to the above example. In particular, the inner diameter of the ejection port is a range in which the ejection voltage that enables ejection of droplets due to the effect of electric field concentration is less than 1000 V, for example, 100 μm or less, and more preferably 20 μm or less. An inner diameter, for example, 0.1 μm, in which it is feasible to form a through hole through which a solution is passed by the current nozzle forming technique is set as the lower limit.

  The conductive ink supply means is provided inside the nozzle plate 126 at a position that is the root of the nozzle 121 and communicates with the flow path 122 in the nozzle and an ink chamber from an external conductive ink tank (not shown). A supply path 127 that guides conductive ink to 124, and a supply pump (not shown) that applies supply pressure of the solution to the ink chamber 124 are provided.

  The supply pump supplies the conductive ink to the tip of the nozzle 21 and supplies the conductive ink while maintaining the supply pressure in a range that does not spill from the tip.

  The discharge voltage applying means 125 applies a discharge voltage to the conductive ink in the nozzle 121 to charge the conductive ink, thereby discharging the conductive ink droplets from the discharge port of the nozzle 121 to the ink receiving substrate K. It is made to discharge toward. The discharge voltage applying means 125 is provided inside the nozzle plate 126 at the boundary position between the ink chamber 124 and the nozzle flow path 122, and the discharge electrode 128 for applying a discharge voltage is always applied to the discharge electrode 128. A bias power source 130 that applies a DC bias voltage and an ejection voltage power source 129 that applies a pulse voltage that is superimposed on the bias voltage and that is a potential required for ejection to the ejection electrode 128 are provided.

  The discharge electrode 128 directly contacts the conductive ink inside the ink chamber 124 to charge the conductive ink and apply a discharge voltage.

  The bias voltage from the bias power source 130 is applied in a constant range within the range where conductive ink is not discharged, thereby reducing the voltage range to be applied during discharge in advance, thereby improving the reactivity during discharge. I am trying.

  As an example, the bias voltage is applied at 300V DC and the pulse voltage is marked at 100V. Therefore, the superimposed voltage at the time of ejection is 400V.

  The nozzle plate 126 has an upper surface layer 126a positioned at the uppermost layer, a flow path layer 126b that forms a supply path for conductive ink positioned therebelow, and a lower surface layer 126c that is formed further below the flow path layer 126b. The discharge electrode 128 is interposed between the flow path layer 126b and the lower surface layer 126c.

  The counter electrode 123 has a counter surface perpendicular to the nozzle 121, and supports the ink receiving substrate K along the counter surface. The distance from the tip of the nozzle 121 to the facing surface of the counter electrode 123 is kept constant, for example, 100 μm.

  Further, since the counter electrode 123 is grounded, the ground potential is always maintained. Accordingly, when a pulse voltage is applied, the liquid droplets ejected by the electrostatic force generated by the electric field generated between the tip of the nozzle 121 and the opposing surface are guided to the opposing electrode 123 side.

  The conductive ink ejection device 120 ejects liquid droplets by increasing the electric field strength by concentrating the electric field at the tip of the nozzle 121 due to the ultra-fine nozzle 121, so there is no induction by the counter electrode 123. In both cases, it is possible to discharge droplets, but it is desirable that induction is performed between the nozzle 121 and the counter electrode 123 by electrostatic force. In this case, the droplet discharged from the nozzle 121 and decelerated by air resistance can be accelerated by the mirror image force. Therefore, by balancing the deceleration by the air resistance and the acceleration by the mirror image force, it is possible to stably fly the fine droplets and improve the landing accuracy. Further, the charge of the charged droplet can be released by grounding the counter electrode 123.

  The conductive ink discharge device 120 as described above may be a scanning type conductive ink discharge device that can be scanned in a direction orthogonal to the transport direction of the ink receiving substrate K by a driving mechanism (not shown). In this case, a plurality of nozzles 121 may be arranged in the conductive ink discharge device 120. Further, the conductive ink discharge device 120 may be a line-type conductive ink discharge device in which a large number of nozzles 121 are arranged in a direction orthogonal to the transport direction of the ink receiving substrate K.

  Further, a detailed configuration of an ink jet recording apparatus applicable to the present invention will be described with reference to the drawings.

  In the method for producing a conductive pattern of the present invention, the inkjet ink of the present invention is applied to a nozzle plate having ejection holes, a pressure chamber communicating with the ejection holes, a pressure generating element that causes pressure fluctuations in the liquid in the pressure chamber, and pressure generation. A conductive pattern is produced using an ink jet recording apparatus having a voltage applying means for applying a voltage to the element and an electric field applying means using an electrostatic force.

(Droplet ejection head)
An example of a droplet discharge head preferably used in the present invention will be described with reference to FIGS.

  FIG. 2 schematically shows a nozzle plate 1, a body plate 2, and pressure generating means 3 constituting an ink jet recording head (hereinafter referred to as a recording head) A which is an example of a droplet discharge head. .

  Here, first, a case where a piezoelectric element is used as pressure generating means which is one of the discharging means will be described.

  A plurality of ejection holes 11 for ejecting ink are arranged in the nozzle plate 1. Further, the nozzle plate 1 is bonded to the body plate 2 so that the pressure chamber groove 24 serving as a pressure chamber, the ink supply path groove 23 serving as an ink supply path, the common ink chamber groove 22 serving as a common ink chamber, and the ink. A supply port 21 is formed.

  And the flow path unit M is formed by bonding the nozzle plate 1 and the body plate 2 so that the discharge hole 11 of the nozzle plate 1 and the pressure chamber groove 24 of the body plate 2 correspond one-to-one. Hereafter, the reference numerals of the pressure chamber groove, the supply path groove and the common ink chamber groove used in the above description are also used for the pressure chamber, the supply path and the common ink chamber, respectively.

  Here, FIG. 3 shows a cross section of the recording head A after the nozzle plate 1, the body plate 2, and the piezoelectric element 3 are assembled, and the Y-Y of the nozzle plate 1 and the X-X position of the body plate 2. Is schematically shown. As shown in FIG. 3, the piezoelectric element 3 is bonded to the flow path unit M to the surface of the bottom 25 of each pressure chamber 24 opposite to the surface to which the nozzle plate 1 of the body plate 2 is bonded. Thus, the recording head A is completed. A driving voltage is applied to each piezoelectric element 3 of the recording head A, and vibration generated from the piezoelectric element 3 is transmitted to the bottom 25 of the pressure chamber 24, and the pressure in the pressure chamber 24 is changed by the vibration of the bottom 25. Ink droplets are ejected from the ejection holes 11.

(Drive voltage)
The relationship between the drive voltage of the piezoelectric element in the ink jet recording apparatus according to the present invention and the behavior of the liquid in the ejection hole will be described.

  The droplet discharge head used in the present invention includes a nozzle plate having discharge holes, a pressure chamber communicating with the discharge holes, and a pressure generating element that causes a pressure fluctuation in the liquid in the pressure chamber, By applying a predetermined drive voltage to the element to cause a pressure fluctuation in the liquid in the pressure chamber, the liquid is discharged from the discharge hole. This liquid discharge state changes in accordance with the degree of pressure fluctuation, in other words, the driving voltage to the pressure generating element. In general, the liquid discharge state is actually influenced not only by the drive voltage but also by various other factors. Here, the influence of the drive voltage will be described.

  As an example of the waveform of the drive voltage Ve applied to the pressure generating means when ejecting the droplet, the waveforms shown in FIGS. 4 and 5 can be exemplified. However, it is not restricted to these waveforms.

(Droplet discharge method using electrostatic force)
The electric field applying means used in the droplet discharge method using electrostatic force has been described with reference to FIG. 1 described above, but will be further described according to an example of the droplet discharge apparatus shown in FIG.

  FIG. 6 is a schematic diagram showing the overall configuration of a liquid discharge apparatus 60 configured using the droplet discharge head B. Electrostatic voltage application for charging the liquid in the nozzle made of a conductive material such as NiP, Pt, Au, etc., for example, on the inner peripheral surface of the large diameter portion 15 of the nozzle plate 1 used for the droplet discharge head B A charging electrode 50 as a means is provided. By providing the charging electrode 50, the charging electrode 50 comes into contact with the liquid in the large diameter portion 15 of the nozzle plate 1. When an electrostatic voltage is applied between the charging electrode 50 from the electrostatic voltage power supply 51 and the counter electrode 54 provided with the base material 53 on which the discharged droplets land, the liquid in the large diameter portion 15 is simultaneously discharged. Charged. Due to this charging, an electrostatic attraction force is generated between the counter electrode 54 provided at a position facing the nozzle hole 11 of the droplet discharge head, particularly between the liquid and the base material 53 on which the discharged droplets land. Can be generated.

  Piezoelectric elements 3 as pressure generating means are provided on the back surface portions corresponding to the pressure chambers 24, respectively. A driving voltage power source 52 for applying a driving voltage to the piezoelectric element 3 to deform the piezoelectric element 3 is connected to the piezoelectric element 3. The piezoelectric element 3 is deformed by the application of a driving voltage from the driving voltage power supply 52 to generate a pressure in the liquid in the nozzle and form a liquid meniscus in the discharge hole 13 of the nozzle 11. Here, as described above, the liquid repellent layer 45 is provided on the ejection surface 12 where the ejection holes 13 are present, so that the liquid meniscus formed in the ejection hole 13 portion of the nozzle is around the ejection holes 13. It is possible to effectively prevent a decrease in electric field concentration on the meniscus tip due to spreading on the discharge surface 12. A control unit 55 controls the liquid ejection device 60 such as the drive voltage power source 52 and the electrostatic voltage power source 51.

  Accordingly, a droplet discharge head capable of efficiently discharging droplets by a synergistic effect between the application of pressure to the liquid by the piezoelectric element 3 and the electrostatic attraction force to the liquid by the charging electrode 50 can be obtained. In other words, if electrostatic attraction force does not work, electrostatic attraction can be applied even when ejecting small droplets that do not reach the normal landing position due to the effect of air resistance during flight. It is possible to land at a regular landing position with high accuracy by the action of force, and it is possible to form a good ink pattern.

<Ink-receiving substrate>
The ink receiving substrate used to form the conductive pattern using the inkjet ink of the present invention is a resin film such as a polyimide film, a polyamideimide film, a polyamide film, or a polyester film, a glass-epoxy substrate, a silicon substrate, or a ceramic substrate. And a glass substrate.

  The material of the resin film used in the present invention is not particularly limited. For example, polyester film (polyethylene terephthalate, polyethylene naphthalate, etc.), polycarbonate film, polyarylate film, polysulfone (including polyethersulfone). Film, polyethylene film, polypropylene film, polyvinylidene chloride film, polyvinyl alcohol film, ethylene vinyl alcohol film, syndiotactic polystyrene film, polycarbonate film, cycloolefin polymer film (Arton (manufactured by JSR), Zeonex, Zeonea (and above) , Manufactured by Nippon Zeon)), polyethersulfone film, polysulfone film, polymethylpentene film, poly Chromatography ether ketone film, polyether ketone imide film, a polyamide film, a fluororesin film, a nylon film, polymethyl methacrylate film, polyacrylate films, and polyarylate films. The film which laminated | stacked the film of the different material which has these materials as a main component may be sufficient.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "part by mass" or "mass%" is represented.

《Organic semiconductor compound》
Organic semiconductor compound 1 (6,13-bisisopropylsilylethynylpentacene) is described in J. Org. Am. Chem. Soc. , Vol. 123 (2001), p9482, supporting information. The organic semiconductor compound 2 [poly (3-hexylthiophene)] purchased from Aldrich was used.

<Ionic liquid>
Ionic liquid 1: 1-ethyl-3-methylimidazolium tetrafluoroborate, (number of carbon atoms: 6, molecular weight: 198, melting point: 6 ° C., manufactured by Merck & Co., Inc.)
Ionic liquid 2: 1-octadecyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide (carbon atoms: 24, molecular weight: 616, melting point: 25 ° C. or less, manufactured by Merck & Co., Inc.)
Ionic liquid 3: 1-butyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide (carbon atoms: 10, melting point: −5 ° C., manufactured by Kanto Chemical Co., Inc.)
<Preparation of inkjet ink>
[Preparation of Ink 1: Present Invention]
The organic semiconductor compound 1 (6,13-bisisopropylsilylethynylpentacene) and ionic liquid 1 (1) are added to the organic solvent 1 (tetralin, relative dielectric constant: 2.7, boiling point: 208 ° C.) at the addition ratio shown below. -Ethyl-3-methylimidazolium tetrafluoroborate) was mixed and dissolved. Next, the obtained solution was filtered through a 0.45 μm filter to prepare ink 1.

Organic semiconductor compound 1 (6,13-bisisopropylsilylethynylpentacene)
1.00% by mass
Organic solvent 1 (tetralin) 99.99% by mass
Ionic liquid 1 (1-ethyl-3-methylimidazolium tetrafluoroborate)
0.01% by mass
[Preparation of ink 2: the present invention]
Ink 1 was prepared in the same manner as in preparing ink 1 except that ionic liquid 2 (1-octadecyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide) was used instead of ionic liquid 1. did.

[Preparation of Ink 3: Present Invention]
Ink 3 was prepared in the same manner as in preparing Ink 1 except that ionic liquid 3 (1-butyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide) was used instead of ionic liquid 1. did.

[Preparation of ink 4: the present invention]
Ink 4 was prepared in the same manner except that organic solvent 2 (toluene, relative dielectric constant: 2.2, boiling point: 111 ° C.) was used instead of organic solvent 1 (tetralin) in the preparation of ink 3. .

[Preparation of Ink 5: Examples]
Ink 5 was prepared in the same manner except that organic semiconductor compound 2 [poly (3-hexylthiophene)] was used in place of organic semiconductor compound 1 in the preparation of ink 3.

[Preparation of Ink 6: Comparative Example]
Ink 5 was prepared in the same manner as in the preparation of Ink 1 except that the ionic liquid 1 was omitted and the amount of organic solvent 1 (tetralin) added was changed to 99.00% by mass.

[Preparation of Ink 7: Comparative Example]
Ink 7 was prepared by mixing and dissolving the following additives.

Pigment: C.I. I. Pigment Red-122 4.00 mass%
Styrene-stearyl methacrylate copolymer 4.00% by mass
Ionic liquid 2: 1-octadecyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide 12.00% by mass
Isopar H (water-insoluble organic solvent, manufactured by Exxon) 80.00% by mass
<Evaluation of ink>
Each ink prepared above was evaluated according to the following method.

[Evaluation of satellite resistance]
Each ink is loaded and discharged into an ink jet recording apparatus having the pressure applying means and electric field applying means shown in FIG. 6 having a nozzle diameter of 5 μm and a discharge ink droplet amount of 0.1 pl, and discharged from the nozzle holes. The flying state of the ink droplets was measured for the number of satellites generated using a CCD camera, and the satellite resistance was evaluated according to the following criteria. The drive voltage of the piezoelectric element provided in the droplet discharge head is 1.1 times the maximum voltage that the ink rises from the discharge hole but returns to the discharge hole without forming a droplet. Each was set to 1 kV.

◎: Less than 5% of satellites generated from the number of ink droplets ejected from the nozzle ○: More than 5% but less than 10% of satellites generated from the number of ink droplets ejected from the nozzle △: Ejected from the nozzle Satellite generation is 10% or more and less than 20% with respect to the number of ink droplets ×: Satellite generation is 20% or more with respect to the number of ink droplets ejected from the nozzle [Evaluation of decap resistance]
Using the inkjet recording head shown in FIG. 6 having a nozzle diameter of 5 μm and an ejected ink droplet amount of 0.1 pl, each of the above prepared inks has an emission interval of 1 as an initial state in an environment of 23 ° C. and 60% RH. The drive voltage and electrostatic force of the piezoelectric element provided in the droplet discharge head were determined so that the ink droplet velocity was 8 m / sec at milliseconds.

  Next, the emission interval time was changed, the relative ratio of the droplet velocity was measured according to the following formula, and the decap resistance was evaluated according to the following criteria.

  For example, 100 ink droplets are ejected at an ejection interval of 1 millisecond, and after a time interval of t seconds from the first ejection, 100 droplets are ejected again at an ejection interval of 1 millisecond, and the first ink droplet after an interval time of t seconds. Is measured as a droplet velocity after an interval time t.

Relative ratio of droplet velocity (%) = (droplet velocity after ejection interval t seconds) / (droplet velocity at ejection interval 1 ms = 8 m / sec) × 100
A: The interval time t at which the relative ratio of the droplet velocity is 70% or less is 10 seconds or more. O: The interval time t at which the relative ratio of the droplet velocity is 70% or less is 1 second or more and less than 10 seconds. Δ: The interval time t at which the relative proportion of the droplet velocity is 70% or less is 0.3 seconds or more and less than 1 second. ×: The interval time t at which the relative proportion of the droplet velocity is 70% or less. <0.3 seconds [Evaluation of line width reproducibility]
Each ink is loaded into an ink jet recording apparatus having the pressure applying means and the electric field applying means shown in FIG. 6, and a plurality of straight lines having a line width of 10 μm are formed on a glass plate washed with an alkaline aqueous solution at a line interval of 50 μm. Formed. The drive voltage of the piezoelectric element provided in the droplet discharge head is 1.1 times the maximum voltage that the liquid rises from the discharge hole but returns to the discharge hole without forming a droplet. Each was set to 1 kV.

  The formed pattern was dried at room temperature, observed with an optical microscope, and evaluated as follows.

  The line widths at arbitrary 50 locations of the formed pattern were measured, the average spring width Wave and the line width variation degree were calculated according to the following formula, and the fine line reproducibility was evaluated according to the following criteria.

Average line width Wave = (W1 + W2 +... + W50) / 50 × 100
(W1, W2,... Represent the line width of the first measurement position, the line width of the second measurement position,...)
Line width variation = (| W1-Wave | + | W2-Wave | +... + | W50−Wave |) / 50 × 100
(The smaller the variation in line width, the more uniform and preferable the line width.)
<Evaluation criteria>
○: Line width variation is less than 1% Δ: Line width variation is 1% or more and less than 5% ×: Line width variation is 5% or more [Evaluation of Semiconductor Characteristics]
(Production of semiconductor elements)
A 200 nm thick thermal oxide film was formed on a Si wafer having a specific resistance of 0.01 Ω · cm as a gate electrode to form a gate insulating layer, and then surface treatment with octadecyltrichlorosilane was performed.

  On the Si wafer subjected to such surface treatment, gold was evaporated using a mask to form source and drain electrodes. The source and drain electrodes were manufactured to have a width of 100 μm, a thickness of 200 nm, a channel width W = 3 mm, and a channel length L = 20 μm.

  The ink jet recording apparatus provided with the pressure applying means and the electric field applying means shown in FIG. 6 was loaded and landed between the source and drain electrodes using the inks 1 to 6 produced above. The driving voltage of the piezoelectric element provided in the droplet discharge head is 1.1 times the maximum voltage that the liquid rises from the discharge hole but returns to the discharge hole without forming a droplet, and the electrostatic force is 1 kV Set each. It was naturally dried and heat-treated at 50 ° C. for 30 minutes in a nitrogen atmosphere.

(Evaluation of carrier mobility and ON / OFF value)
About the obtained organic thin-film transistor, the carrier mobility and ON / OFF value of each element were measured immediately after element preparation. In the present invention, the carrier mobility is obtained from the saturation region of the IV characteristic, and the ON / OFF ratio is obtained from the ratio of the drain current values when the drain bias is −50 V and the gate bias is −50 V and 0 V. The semiconductor characteristics were evaluated according to the following criteria.

<Evaluation criteria>
○: Carrier mobility is 0.01 cm ² / Vsec or more and ON / OFF ratio is 10 ⁶ or more Δ: Carrier mobility is 0.01 cm ² / Vsec or more, or ON / OFF ratio is 10 ⁶ Satisfying either of the above ×: Carrier mobility is less than 0.01 cm ² / Vsec and ON / OFF ratio is less than 10 ⁶ Table 1 shows the results obtained.

  From the results shown in Table 1, the level using the ink jet recording apparatus having the pressure applying means and the electric field applying means and the ink of the present invention is superior to the comparative example in satellite resistance, decap resistance and fine line reproducibility. In addition, it can be seen that the formed conductive pattern has excellent semiconductor characteristics.

  Moreover, it replaces with the inkjet recording device provided with the pressure application means and electric field application means shown in FIG. 6, and uses for each said evaluation using the Seiko Epson ink-jet printer PXG-900 which has only a pressure application means. As a result of performing the same evaluation with respect to the inks 1 to 5 after modifying the ink discharge conditions to be the same as the ink discharge conditions, sufficient results for satellite resistance, decap resistance and fine line reproducibility could not be obtained. .

1 is a schematic cross-sectional view illustrating an example of an ink jet recording apparatus including a pressure applying unit and an electric field applying unit that can be preferably applied to the present invention. It is a schematic diagram showing an example of a droplet discharge head of an ink jet recording apparatus that can be preferably applied to the present invention. FIG. 2 is a schematic diagram illustrating a cross section of an example of a droplet discharge head of an ink jet recording apparatus that can be preferably applied to the present invention. It is a schematic diagram which shows an example of the waveform of the drive voltage Ve at the time of droplet discharge. It is a schematic diagram which shows another example of the waveform of the drive voltage Ve at the time of droplet discharge. 1 is a schematic diagram illustrating an example of an overall configuration of an ink jet recording apparatus that can be preferably applied to the present invention.

Explanation of symbols

A Inkjet recording head 1 Nozzle plate 2 Body plate 3 Pressure generating means 11 Ejection hole for ejecting ink 21 Ink supply port 22 Common ink chamber groove 23 Ink supply path groove 24 Pressure chamber groove serving as pressure chamber 60 Liquid ejection device 120 Conductive ink discharge device 121 Nozzle 122 Flow path in nozzle 123 Counter electrode 124 Ink chamber 125 Discharge voltage applying means 126 Nozzle plate 127 Supply path 128 Discharge electrode 130 Bias power supply 130 K Ink receiving substrate

Claims (5)

An ink-jet ink used for forming a pattern image by being ejected by an ink-jet recording apparatus having a pressure applying means and an electric field applying means, comprising an organic semiconductor compound, an organic solvent having a relative dielectric constant of 10 or less, and the following general formula An ink-jet ink comprising at least one selected from ionic liquids represented by (1) to (5).

[Wherein, Q ₁ represents an atomic group that forms a 5- or 6-membered aromatic cation with a nitrogen atom. R ₁ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted alkenyl group. X ⁻ represents an anion. ]

[Wherein, A ₁ represents a nitrogen atom or a phosphorus atom. R _{2 to} R ₅ each independently represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted alkenyl group. X ⁻ represents an anion. ]

[Wherein, R _{6 to} R ₁₁ each independently represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted alkenyl group. X ⁻ represents an anion. ]
General formula (4)
^{_{P + R 12 R 13 R 14}} R 15 · X -
[Wherein, R _{12 to} R ₁₅ each independently represents a substituted or unsubstituted alkyl group, aryl group, heterocyclic group or aralkyl group, which may be the same or different. X ⁻ represents an anion. ]

[Wherein, X and Y each represents an alkyl group having 1 to 4 carbon atoms, and may be the same or different. k and i each represents 0 or a positive integer of 1 to 4, n and m each represents a positive integer of 3 to 7, and A represents an acid component. ] 2. The ink according to claim 1, wherein the ionic liquid represented by the general formulas (1) to (5) has 10 to 20 carbon atoms. The inkjet ink according to claim 1, wherein the organic semiconductor compound is 6,13-bistriisopropylsilylethynylpentacene or 1,3,6-N-sulfinylacetamidopentacene. The inkjet ink according to claim 1, wherein the organic solvent having a relative dielectric constant of 10 or less has a boiling point of 150 ° C. or more and 250 ° C. or less. A conductive pattern production method for producing a conductive pattern by discharging the inkjet ink according to any one of claims 1 to 4 from an inkjet recording apparatus, wherein the inkjet recording apparatus includes a nozzle plate having discharge holes. And a pressure chamber communicating with the discharge hole, a pressure generating element for causing a pressure fluctuation in the liquid in the pressure chamber, a voltage applying means for applying a voltage to the pressure generating element, and an electric field applying means using an electrostatic force. A conductive pattern manufacturing method.

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