JP2010155882A - Ink for transparent conductive film formation and transparent conductive film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide ink for transparent conductive film formation which forms a good pattern shape by a coating method using an inkjet printer. <P>SOLUTION: The ink for transparent conductive film formation contains transparent conductive particles, a dispersant, a surface modifier and a solvent, wherein the content of the solvent is 40-99 wt.% relative to the total weight of the ink, the solvent is at least one selected from the group consisting of 2-methyl-2,4-pentanediol, diethylene glycol mono-2-ethylhexyl ether, ethylene glycol mono-2-ethylhexyl ether and dipropylene glycol methyl ether acetate, and a contact angle of the ink with a substrate is 5-10°. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a transparent conductive film forming ink capable of forming a transparent conductive film by coating on a non-absorbing surface such as a plastic substrate, a glass substrate, and a film substrate, and a transparent conductive film formed using the same. .

  Conventionally, as materials for transparent conductive films and transparent conductive inks, tin oxide particles, antimony-containing tin oxide particles (ATO), tin-containing indium oxide particles (ITO), aluminum-containing zinc oxide particles (AZO), gallium-containing zinc oxide Particles (GZO) and the like are known. In particular, tin-containing indium oxide particles in which tin is contained in indium oxide are cathode ray tubes for office automation (OA) equipment that are required to have anti-static and electromagnetic shielding because of their high transparency to visible light and high conductivity. (CRT) panel surfaces, liquid crystal display (LCD) surfaces, etc. are used by coating. Furthermore, the transparent conductive film produced by applying a coating liquid (ink) containing tin-containing indium oxide particles is expected to be applied to fields that require higher translucency and conductivity, such as touch panels. Yes.

  In addition, the film forming method of the transparent conductive film that is mainly used at present is a physical method such as a vacuum evaporation method or a sputtering method, but with the increase in size of the substrate on which the film is formed, the manufacturing apparatus becomes large, There is a problem that the cost becomes high.

  Thus, from the viewpoint of cost and simplicity, the formation of a transparent conductive film by a coating method has been studied. For example, a method for forming an ITO transparent conductive film by applying, drying, and baking on a substrate such as glass by spin coating, spray coating, dip coating or the like using a silica sol solution containing ITO fine particles is known. (For example, refer to Patent Document 1).

  Recently, research on a method of forming a film by a coating method using an ink jet printer has been actively conducted. This is because the use of a film forming method using an ink jet printer has the advantage that the transparent conductive film can be directly patterned on the substrate and the etching process for patterning can be omitted.

  However, the transparent conductive ink for an ink jet printer is required to be adjusted to the optimum viscosity and surface tension of the ink corresponding to the printer head and ensure the dispersion stability of the ink. Usually, the pigment ink used for an inkjet printer adjusts the viscosity and the surface tension to an optimum range by adding a viscosity modifier. However, when this method is applied to a transparent conductive ink for an ink jet printer, there are problems that coloring due to the addition of a viscosity modifier, a decrease in conductivity, a decrease in transmittance, and the like occur. For this reason, various improvements have been made on transparent conductive ink for inkjet printers.

  For example, in Patent Document 2, a coating solution containing acetylacetone indium, organotin compound, cellulose derivative, alkylphenol and / or alkenylphenol, dibasic acid ester and / or benzyl acetate, diethylene glycol derivative is prepared, and acetylacetone indium and organotin are prepared. By optimizing the content with the compound and the content of the cellulose derivative, problems such as dispersion stability of the transparent conductive particles, nozzle clogging, and viscosity of the coating liquid required for the transparent conductive ink for inkjet printers can be solved. It is disclosed that a coating liquid for forming a transparent conductive film suitable for inkjet printing can be obtained.

In Patent Document 3, a coating liquid containing conductive oxide fine particles, an inorganic binder, and a solvent is prepared. The average particle diameter of the conductive oxide fine particles, the average weight molecular weight of the inorganic binder, and the type and content of the solvent. By optimizing the solution, problems such as dispersion stability of transparent conductive particles, nozzle clogging, and viscosity of coating solution required for transparent conductive ink for inkjet printers can be solved, and transparent conductive film formation suitable for inkjet printing It is disclosed that a coating liquid for use is obtained.
Japanese Patent Laid-Open No. 2-312136 JP 2006-28431 A JP 2006-114396 A

  Thus, a transparent conductive film can be formed by inkjet printing using a transparent conductive ink. However, the conventional transparent conductive ink does not always satisfy the characteristics such as the flatness and edge shape of the coating film on the substrate after ink jet printing, and can form a transparent conductive film having a better pattern shape. However, further improvement of these characteristics is required.

  The present invention solves the above problems and provides a transparent conductive film forming ink capable of forming a good pattern shape by a coating method using an ink jet printer, and further for forming a transparent conductive film of the present invention. By using ink, a transparent conductive film having both good conductivity and transparency is provided.

  The ink for forming a transparent conductive film of the present invention is an ink for forming a transparent conductive film containing transparent conductive particles, a dispersant, a surface modifier, and a solvent, and the content of the solvent is the ink. 40 to 99% by weight based on the total weight, and the solvent is 2-methyl-2,4-pentanediol, diethylene glycol mono-2-ethylhexyl ether, ethylene glycol mono-2-ethylhexyl ether and dipropylene glycol It is at least one selected from the group consisting of methyl ether acetate, and the contact angle with the substrate is 5 ° to 10 °.

  The transparent conductive film of the present invention is formed using the transparent conductive film forming ink of the present invention.

  The ink for forming a transparent conductive film of the present invention can form a good pattern shape by a coating method using an ink jet printer. In addition, since the transparent conductive film of the present invention is formed using the ink for forming a transparent conductive film of the present invention, it has a good pattern shape and has both good conductivity and transparency. It can be applied to transparent electrodes such as paper, flat panel display (FPD) and solar cells.

  As a result of intensive studies to solve the above problems, the inventors have made contact with the ink substrate while satisfying the dispersion stability, viscosity, and surface tension of the transparent conductive particles required for the transparent conductive ink for an ink jet printer. The inventors have found that a favorable transparent conductive film can be formed by preparing the ink composition so that the angle is 5 ° to 10 °, and the present invention has been completed.

(Embodiment 1)
First, the transparent conductive film forming ink of the present invention will be described.

  The ink for forming a transparent conductive film of the present invention contains transparent conductive particles, a dispersant, a surface modifier, and a solvent. The content of the solvent is 40 to 99% by weight with respect to the total weight of the ink. The solvent is at least one selected from the group consisting of 2-methyl-2,4-pentanediol, diethylene glycol mono-2-ethylhexyl ether, ethylene glycol mono-2-ethylhexyl ether, and dipropylene glycol methyl ether acetate. . Moreover, the contact angle with the board | substrate of the ink for transparent conductive film formation of this invention is 5 degrees-10 degrees.

  By setting it as the said composition, the contact angle with the board | substrate of an ink can be set to 5 degrees-10 degrees, satisfy | filling the dispersion stability, the viscosity, and surface tension which are requested | required of the ink for transparent conductive film formation for inkjet printers. Thereby, even if it apply | coats using an inkjet printer, a favorable pattern shape can be formed.

  When the contact angle is less than 5 °, the edge shape of the application surface is not maintained as printed, whereas when the contact angle exceeds 10 °, an application surface having a certain area is formed using an inkjet printer. Sometimes, the drop inks do not overlap each other, a flat film cannot be formed, and in order to increase the overlap, if the drop interval is set densely, the amount of solvent per unit application area increases and during drying, A flat film cannot be formed due to the movement of the ink.

  The solvent is a solvent having a viscosity adjusting function and a wettability adjusting function, but another (poly) alkylene glycol derivative as a solvent (second solvent) having another viscosity adjusting function in addition to the solvent (first solvent). May be added. By using these first and second solvents, the contact angle of the ink with the substrate can be set more efficiently at 5 ° to 10 °. Thereby, the transparent conductive film in which the flatness and edge shape of the coating film after inkjet printing are further improved can be formed.

  When the solvent is used, the content of the first solvent is 10 to 100% by weight with respect to the total weight of the solvent, and the content of the second solvent is based on the total weight of the solvent. 0 to 90% by weight.

  The (poly) alkylene glycol derivative of the second solvent preferably has a flash point in the range of 70 to 120 ° C and a boiling point in the range of 170 to 250 ° C. As an ink for an ink jet printer, a solvent having a high boiling point of 170 ° C. or higher is preferable to prevent nozzle clogging, and the boiling point is 250 ° C. or lower in consideration of easiness of drying after dropping. It is preferable.

  The (poly) alkylene glycol derivative may be at least one selected from monoalkyl ether monoalkyl ester compounds, dialkyl ether compounds and dialkyl ester compounds of (poly) alkylene glycol.

  More specifically, the (poly) alkylene glycol derivative includes ethylene glycol monoalkyl ether monoalkyl ester, diethylene glycol monoalkyl ether monoalkyl ester, triethylene glycol monoalkyl ether monoalkyl ester, propylene glycol monoalkyl ether monoalkyl ester. , Dipropylene glycol monoalkyl ether monoalkyl ester, tripropylene glycol monoalkyl ether monoalkyl ester, ethylene glycol dialkyl ether, diethylene glycol dialkyl ether, propylene glycol dialkyl ether, dipropylene glycol dialkyl ether, ethylene glycol dialkyl ester, and propylene glycol di Archi It is possible to use at least one selected from the group consisting of esters.

  The transparent conductive particles are not particularly limited as long as the particles have both transparency and conductivity. For example, conductive metal oxide particles and conductive nitride particles can be used. Examples of the conductive metal oxide particles include metal oxide particles such as indium oxide, tin oxide, zinc oxide, and cadmium oxide. In addition, conductive metal oxide particles doped with tin, antimony, aluminum, gallium, with one or more metal oxides selected from the group consisting of indium oxide, tin oxide, zinc oxide and cadmium oxide as main components, For example, tin-containing indium oxide particles (ITO), antimony-containing tin oxide particles (ATO), aluminum-containing zinc oxide particles (AZO), gallium-containing zinc oxide particles (GZO), and conductive metal oxide particles obtained by replacing ITO with aluminum. Is mentioned. Among these, ITO is particularly preferable because it is excellent in transparency, conductivity, and chemical characteristics. Here, the main component is a metal oxide serving as a crystal matrix in the conductive metal oxide particles.

  The primary particle diameter of the transparent conductive particles is preferably 5 to 150 nm. If the primary particle size is less than 5 nm, it tends to be difficult to obtain particles with good crystallinity. On the other hand, if the primary particle size is larger than 150 nm, the transparency tends to decrease. In the present invention, the primary particle diameter means the average of the particle diameters of at least 20 particles after observing and measuring the particle diameters of individual particles separated by grain boundaries using a transmission electron microscope (TEM). Mean particle diameter.

  As the dispersant, it is preferable to use a comb copolymer having both a basic functional group and an acidic functional group as a particle adsorption site having a large effect of dispersing the transparent conductive particles. Examples of the comb copolymer include “Solspers 20000”, “Solspers 24000”, “Solspers 26000”, “Solpers 27000”, “Solpers 28000”, “Solpers 32500”, “Solpers 32550”, “Solpers 35100”, “Solspers 37500”, “Solpers 90500” Solspers 56000 "(manufactured by Nihon Lubrizol)," Disperbyk-160 "," Disperbyk-161 "," Disperbyk-162 "," Disperbyk-162 "," Disperbyk-163 "," Disperbyk-166b "," Disperbyk-166p " -170 "," Disperbyk- 81 ”,“ Disperbyk-182 ”,“ Disperbyk-183 ”,“ Disperbyk-184 ”,“ Disperbyk-190 ”,“ Disperbyk-2155 ”,“ Disperbyk-2163 ”,“ Disperbyk-2164 ” ) Etc. can be used.

  Examples of the surface modifier include polyether-modified polydimethylsiloxane, polyester-modified methylalkylpolysiloxane, aralkyl-modified polymethylalkylsiloxane, polyether-modified polymethylalkylsiloxane, polyether-modified polydimethylsiloxane, fluorine-modified polymer, Use at least one selected from the group consisting of polyester-modified hydroxyl group-containing polydimethylsiloxane, polyetherester-modified hydroxyl group-containing polydimethylsiloxane, acrylic copolymer, polydimethylsiloxane having polyether-modified acrylic group, and silicon-modified polyacryl. Can do. By using the surface modifier, the wettability of the ink to the substrate can be improved.

  The ink for forming a transparent conductive film of the present invention comprises mixing the transparent conductive particles, the dispersant, the surface modifier, and the solvent, and dispersing the transparent conductive particles in the solvent. Can be made. The method for dispersing the transparent conductive particles in the solvent is not particularly limited. For example, a mechanical dispersion treatment with media such as a ball mill, a sand mill, a pico mill, or a paint conditioner may be performed. Alternatively, a dispersion treatment using a homogenizer, a disper, a jet mill or the like may be performed.

  Moreover, it is preferable that the dispersion average particle diameter of the said transparent conductive particle is 150 nm or less. This is because if the dispersion average particle size exceeds 150 nm, haze increases and transparency tends to decrease. In the present invention, the dispersion average particle diameter means an average particle diameter of dispersed particles including primary particles and secondary particles as measured by a laser Doppler type particle size distribution meter.

  The solid content of the transparent conductive film forming ink of the present invention is in the range of 1 to 60% by weight. When the solid content is less than 1% by weight, sufficient conductivity cannot be obtained when the transparent conductive film is formed, and when it exceeds 60% by weight, the viscosity of the ink increases. In other words, the ink is not suitable for application such as inkjet printing.

  Moreover, it is preferable that content of the transparent conductive particle in solid content is the range of 70 to 98 weight%. This is because if the content of the transparent conductive particles in the solid content is less than 70% by weight, the inhibition of conductivity by solids other than the transparent conductive particles tends to increase.

  The amount of the surface modifier added to the solid content is preferably in the range of 0.0001 to 0.2% by weight, more preferably in the range of 0.01 to 0.1% by weight. preferable. When the addition amount is less than 0.001% by weight, the function as a surface modifier is not sufficiently exhibited. On the other hand, when it exceeds 0.2% by weight, the surface modifier tends to inhibit conductivity. Because there is.

  In order to use the ink for forming a transparent conductive film of the present invention as an ink for an ink jet printer, the characteristics of the ink must be adapted to the head of the ink jet printer. In particular, the viscosity of the ink is preferably in the range of 1.5 to 20 mPa · s, more preferably in the range of 5 to 15 mPa · s, and in the range of 8 to 14 mPa · s. It is particularly preferred. Further, the surface tension of the ink is preferably within a range of 20 to 40 mN / m, and more preferably within a range of 25 to 35 mN / m. When the ink characteristics are within this range, ejection stability can be obtained, which is optimal as an ink for an ink jet printer.

(Embodiment 2)
Next, the transparent conductive film of the present invention will be described.

  The transparent conductive film of the present invention is formed using the transparent conductive film forming ink of the present invention described in Embodiment 1. Specifically, the transparent conductive film is formed by applying the transparent conductive film forming ink to one main surface on the substrate. Application methods include, for example, coating methods such as roll coating, die coating, air knife coating, blade coating, spin coating, reverse coating, and gravure coating, or printing methods such as gravure printing, screen printing, offset printing, and inkjet printing. Can do. In particular, it is preferable to form the transparent conductive film by applying the transparent conductive film forming ink to a substrate by an ink jet printer. This is because by using an ink jet printer, the transparent conductive film can be patterned directly on the substrate, and the etching process for patterning can be omitted.

  The substrate is not particularly limited. For example, a film or sheet made of materials such as polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyolefins, cellulose triacetate, polycarbonate, polyamide, polyimide, polyamideimide, polysulfone, aramid, and aromatic polyamide can be used. The thickness of the substrate is usually 3 to 300 μm. The substrate may be a hard substrate such as a glass plate or may be flexible.

  Drying of the applied transparent conductive film is not limited to room temperature and normal pressure drying, and may be performed by heating or reduced pressure as long as it does not adversely affect the substrate, such as heat drying, reduced pressure drying, and reduced pressure heat drying. The drying step is an important step because it affects the transparency and flatness of the transparent conductive film. However, since the drying behavior varies depending on the solvent, it is preferable to determine the drying method as appropriate depending on the type of the solvent.

  High conductivity can be imparted by further firing the transparent conductive film after drying. This is considered to be because organic substances that impede conductivity can be removed by firing, and the contact resistance between the transparent conductive particles is reduced. Finally, it is necessary to remove the dispersant, the surface modifier, and the solvent, and for that purpose, it is desirable to perform heat treatment at 200 ° C. or higher, preferably 300 ° C. or higher. The heating method is not particularly limited, and a conventional heating method using a high-temperature bath or an electric furnace may be used. However, when the substrate is weak to heat, the transparent conductive film is heated by electromagnetic wave heating or lamp heating so that the heat is not transmitted to the substrate. It is preferable to use a method of heating only.

  When the final thickness of the transparent conductive film of the present invention formed by the above method is 50 to 2000 nm, a transparent conductive film having both good conductivity and transparency and having a good pattern shape is obtained. Can do.

  Hereinafter, the present invention will be described in detail based on examples. However, the present invention is not limited to the following examples.

Example 1
1.8 g of ITO particles having a primary particle size of 30 nm, 0.2 g of a dispersant “Solspers 32550” manufactured by Nippon Lubrizol, and a surface modifier “BYK-370” manufactured by BYK Chemie (polydimethylsiloxane containing a polyester-modified hydroxyl group) ) 0.01 g, 12.6 g of 2-methyl-2,4-pentanediol as a solvent and 5.4 g of dipropylene glycol methyl ether acetate were mixed, and dispersion treatment was performed with a paint conditioner using zirconia beads. Thus, a transparent conductive film forming ink of Example 1 (solvent content: 90% by weight) was prepared.

(Example 2)
Example 1 except that 7.2 g of diethylene glycol mono-2-ethylhexyl ether, 7.6 g of 2-methyl-2,4-pentanediol, and 3.2 g of dipropylene glycol methyl ether acetate were used as the solvent. In the same manner, an ink for forming a transparent conductive film of Example 2 (solvent content: 90% by weight) was prepared.

(Example 3)
Examples were used except that 7.6 g of ethylene glycol mono-2-ethylhexyl ether, 7.6 g of 2-methyl-2,4-pentanediol, and 3.2 g of dipropylene glycol methyl ether acetate were used as the solvent. In the same manner as in Example 1, the transparent conductive film-forming ink of Example 3 (solvent content: 90% by weight) was prepared.

Example 4
9 g of ITO particles having a primary particle size of 30 nm, 1 g of a dispersant “Solspers32550” manufactured by Nippon Lubrizol, and 0.05 g of a surface modifier “BYK-370” manufactured by BYK Chemie (polydimethylsiloxane containing a polyester-modified hydroxyl group) A transparent conductive film-forming ink of Example 4 (solvent content: 50% by weight) was prepared in the same manner as in Example 1 except that 10 g of dipropylene glycol methyl ether acetate was used as a solvent.

(Comparative Example 1)
The transparent conductive film-forming ink of Comparative Example 1 (solvent content: 90), except that 15 g of benzyl alcohol, 1.5 g of toluene, and 1.5 g of methyl ethyl ketone were used as solvents. % By weight) was prepared.

(Comparative Example 2)
A transparent conductive film-forming ink (solvent-containing) was prepared in the same manner as in Example 1 except that 15 g of 2-ethyl-1,3-hexanediol, 1.5 g of toluene, and 1.5 g of methyl ethyl ketone were used as the solvent. Amount: 90% by weight).

(Comparative Example 3)
A transparent conductive film-forming ink was prepared in the same manner as in Example 1 except that the surface modifier was not used.

(Comparative Example 4)
As in Example 1, except that 10.8 g of diethylene glycol mono-2-ethylhexyl ether, 5 g of 2-methyl-2,4-pentanediol, and 2.2 g of dipropylene glycol methyl ether acetate were used as the solvent. Thus, an ink for forming a transparent conductive film of Comparative Example 4 (solvent content: 90% by weight) was prepared.

[Evaluation of characteristics of ink for forming transparent conductive film]
About the transparent conductive film forming inks of Examples 1 to 4 and Comparative Examples 1 to 4, the dispersion stability, the dispersion average particle diameter, the viscosity, the surface tension, the discharge characteristics, and the contact angle were measured and evaluated as follows. The measurement results are shown in Table 1.

<Dispersion stability>
As the evaluation of the dispersion stability of each ink, the prepared ink was allowed to stand for 24 days, and the ink having no sediment was evaluated as A, and the ink having a sediment was evaluated as B.

<Dispersion average particle size>
Using a particle size distribution measuring device “N4-PLUS” (Laser Doppler type particle size distribution meter manufactured by Coulter, Inc.), the dispersion average particle size of the transparent conductive particles was measured.

<Viscosity>
Using an R100 viscometer (manufactured by Toki Sangyo Co., Ltd.), the viscosity was measured under the conditions of 25 ° C. and cone rotation speed of 20 rpm.

<Surface tension>
Using a fully automatic balance type electro surface tension meter “ESB-V” (manufactured by Kyowa Kagaku), the temperature of the ink was set to 25 ° C., and the surface tension was measured.

<Discharge characteristics>
An ink jet printer for solvent ink was filled with ink and evaluated for ejection. Those that could be discharged were evaluated as A, and those that could not be discharged were evaluated as B.

<Contact angle>
Using a UV-ozone cleaning device “OC-2506” (manufactured by Iwasaki Electric Co., Ltd.), one main surface of the alkali-free glass substrate was subjected to UV ozone treatment in air for 5 minutes. Thereafter, an ink with a drop amount of 75 pl was dropped on the glass substrate on the UV ozone-treated side within 10 minutes, and the contact angle was calculated from the drop diameter. The relationship between the drop diameter d (cm), the drop volume (drop amount) V (cm ³ ), and the contact angle θ (°) is expressed by the following equation. The contact angle θ (0 ° <θ ≦ 90 °) can be obtained by substituting the values of the drop diameter and the drop volume into this equation.
V = {πd ³ sin θ (2 + cos θ)} / {24 (1 + cos θ) ² }

[Transparent conductive film formation and film property evaluation]
Using the transparent conductive film forming inks of Examples 1 to 4 and Comparative Examples 1 to 4, a transparent conductive film was formed as described below, and the edge shape and film flatness were measured and evaluated. It was shown in 1.

<Transparent conductive film formation>
First, a non-alkali glass substrate having a length of 50 mm and a width of 50 mm was prepared as a substrate. Next, UV ozone treatment was performed on one main surface of the glass substrate in the air for 5 minutes using a UV-ozone cleaning device “OC-2506” (manufactured by Iwasaki Electric Co., Ltd.).

  Subsequently, an ink was applied onto the glass substrate on the UV ozone-treated side using an ink jet printer. Specifically, about 75 pl of ink was dropped at a pitch of 140 μm, and the ink was applied over the entire surface in the range of 35 mm length and 35 mm width on the glass substrate. Then, after drying at 60 ° C., a transparent conductive film was formed by performing a heat treatment at 250 ° C. for 30 minutes in an air atmosphere.

<Edge shape>
The square shape of the formed transparent conductive film was evaluated as an edge shape. Specifically, the case where the radius of curvature R of the four corners of the transparent conductive film visually was within 0.5 mm was designated as A, and the case where the radius of curvature R was more than 0.5 mm was designated as B. The enlarged photograph of the corner | angular part which planarly viewed the transparent conductive film formed using the ink for transparent conductive film formation of Example 1 in FIG. 1 is shown. Moreover, the enlarged photograph of the corner | angular part which planarly viewed the transparent conductive film formed using the ink for transparent conductive film formation of the comparative example 3 in FIG. 2 is shown.

<Film flatness>
When the formed transparent conductive film is visually observed, the dropped ink is completely connected to form a flat film, and interference fringes cannot be observed A, the dropped ink is not completely connected, or the ink is connected The case where no flat film was formed and interference fringes could be observed was evaluated as B.

  From Table 1, it can be seen that the transparent conductive film formed using the inks of Examples 1 to 4 having a contact angle in the range of 5 to 10 ° has no problem in both the edge shape and the film flatness.

  On the other hand, it can be seen that the transparent conductive films formed using the inks of Comparative Examples 1, 2, and 4 having a contact angle exceeding 10 ° are inferior in film flatness. Moreover, it turns out that the transparent conductive film formed using the ink of the comparative example 3 whose contact angle is less than 5 degrees has a problem in edge shape.

  If the transparent conductive film forming ink of the present invention suitable for application by an ink jet printer is used, a pattern can be directly printed on a substrate without performing a patterning process by photolithography, and complicated pattern formation is required. A transparent conductive film used for a transparent electrode of a display element such as a flat panel display (FPD) or electronic paper, a transparent electrode of a solar cell, an antistatic film, or the like can be easily formed.

It is a figure which shows the enlarged photograph of the corner | angular part which planarly viewed the transparent conductive film formed using the ink for transparent conductive film formation of Example 1. FIG. It is a figure which shows the enlarged photograph of the corner | angular part which planarly viewed the transparent conductive film formed using the ink for transparent conductive film formation of the comparative example 3. FIG.

Claims (7)

A transparent conductive film forming ink comprising transparent conductive particles, a dispersant, a surface modifier, and a solvent,
The content of the solvent is 40 to 99% by weight with respect to the total weight of the ink,
The solvent is at least one selected from the group consisting of 2-methyl-2,4-pentanediol, diethylene glycol mono-2-ethylhexyl ether, ethylene glycol mono-2-ethylhexyl ether and dipropylene glycol methyl ether acetate,
A transparent conductive film forming ink, wherein a contact angle with a substrate is 5 ° to 10 °.   The transparent conductive particles are conductive metal oxide particles, and the conductive metal oxide particles are at least one metal oxide particle selected from the group consisting of indium oxide, tin oxide, zinc oxide, and cadmium oxide. The ink for forming a transparent conductive film according to claim 1.   The ink for forming a transparent conductive film according to claim 2, wherein the conductive metal oxide particles are further doped with at least one element selected from the group consisting of tin, antimony, aluminum, and gallium.   The transparent conductive film forming ink according to any one of claims 1 to 3, wherein the dispersant is composed of a comb copolymer having both a basic functional group and an acidic functional group as a particle adsorption site.   The transparent conductive film forming ink according to any one of claims 1 to 4, which is used as an ink for an ink jet printer.   A transparent conductive film formed using the ink for forming a transparent conductive film according to claim 1.   The transparent conductive film according to claim 6, wherein the transparent conductive film forming ink is applied to a substrate by an inkjet printer.