JP4365596B2 - Method for forming transparent conductive film and coating liquid for transparent conductive film - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for forming a transparent conductive film of indium-tin oxide (ITO) and a coating liquid for the transparent conductive film. Specifically, the coating liquid for the transparent conductive film is sprayed and applied to a heated substrate with a spray nozzle. At the same time, a method of forming a transparent conductive film that allows the atomized coating liquid to pass through a preheating atmosphere to suppress a decrease in the substrate temperature and to form a uniform transparent conductive film on a large substrate And the coating liquid for the transparent conductive film.
[0002]
[Prior art]
Conventional methods for forming a transparent conductive film include a dry film forming method such as a sputtering method, a vacuum vapor deposition method, and a CVD method, and a wet film forming method such as a dip coating method, a spray method, and a spin coating method. The dry film forming method is an effective method in that a high-quality transparent conductive film having high conductivity can be easily formed, but has a difficulty in that the equipment cost is high and the production efficiency is low.
[0003]
On the other hand, the wet film formation method is an effective method in that it can be applied to a large substrate, but among the wet film formation methods, the dip coating method and the spin coating method have a lot of useless consumption of the coating solution. There was a difficulty. In the dip coating method, a substrate immersed in a stored coating solution is pulled up at a predetermined speed to form a thin film, and transparent conductive films are formed on both surfaces of the substrate. Therefore, when the transparent conductive film is formed only on one surface of the substrate, it is necessary to take a measure for preventing the coating liquid from adhering to the back surface of the substrate. On the other hand, the spray method sprays the coating liquid onto a required portion of one surface of the substrate, and can be used for large substrates while suppressing wasteful consumption of the coating solution. is there.
[0004]
As an example of forming a transparent conductive film of ITO by this spray method, indium chloride (InCl _Three : 25g) and stannic chloride (SnCl _Four : 2.1g) in a liquid mixture of water (33ml) and methanol (40ml). _Four F: 2.09 ml)) is added and sprayed onto a glass substrate of about 70 mm square heated to 420 ° C. (for example, see Patent Document 1). Indium chloride (InCl _Three ・ 3.5H ₂ O) and stannous chloride (SnCl ₂ ・ 2H ₂ A transparent conductive film with low volume resistivity and high visible transmittance by spraying a solution of O) in ethanol on a glass substrate (2.5mm x 3.5mm x 0.7mm) heated to 350 ° C in the air Have been reported to be formed (see Non-Patent Document 1, for example).
[0005]
[Patent Document 1]
JP-A-51-75991 (pages 2 to 3)
[Non-Patent Document 1]
2000 Kanagawa Prefectural Government-Government-Academia Exchange Presentation Material “Preparation of ITO Transparent Conductive Film by Spray Method”, pp.21 (2000.10.18)
[0006]
[Problems to be solved by the invention]
However, the spray nozzle used for the formation of the transparent conductive film by the conventional spray method is a type in which the coating liquid is sprayed with a high-pressure gas from a small jet outlet and is sprayed. In addition, the particle size of the mist-like coating liquid is relatively large and non-uniform, and it is difficult to control the spray amount of the coating liquid. In addition, at the substrate temperature heated to a predetermined temperature, the temperature of the portion where the coating solution is applied may drop, and the substrate temperature distribution may be uneven. Therefore, it becomes difficult to form a thin film having a uniform film thickness, and a white turbidity phenomenon may occur for a large-sized substrate due to uneven application of the ITO transparent conductive film. Therefore, in the above conventional examples, all are results for a small glass substrate, and a large substrate having a side dimension of several hundred mm or more has not yet been put into practical use. Moreover, there is no report example about the coating liquid which enabled formation of the homogeneous transparent conductive film without white turbidity with respect to such a large sized substrate.
[0007]
Therefore, the present invention addresses such problems. Large by spraying coating liquid Enables the formation of a homogeneous transparent conductive film on the mold substrate , Enabling improved conductivity and thickening of transparent conductive films An object is to provide a method for forming a transparent conductive film and a coating liquid for the transparent conductive film.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, a method for forming a transparent conductive film according to the present invention comprises: The ratio of methanol to ethanol (methanol / (methanol + ethanol)) is 5 to 80 wt%, and the ratio of water to methanol and ethanol (water / (water + organic solvent)) is 1.5 to 21.0 wt%. A solvent consisting of methanol, ethanol, and water In , Formulated so that Sn / (Sn + In) is 1.0 to 13.0% in terms of moles of indium (In) and tin (Sn). Indium chloride and stannous chloride Dissolve a mixture of 1.5 to 7.0 wt% , further Of hydrochloric acid, chloroauric acid, palladium chloride, ruthenium chloride, chloroplatinic acid, zinc chloride, titanium coupling material, metal alkoxide or aluminum coupling material Selected from Any one or more Add the additive To prepare a coating liquid for the transparent conductive film, 300-350 ° C The transparent conductive film coating liquid is sprayed by a spray nozzle onto a substrate heated to a temperature of 5 ° C., and the transparent conductive film coating liquid atomized thereby is previously applied. 200-300 ° C Preheat by passing through a preheating atmosphere heated to a temperature, Heated On the board The preheated A transparent conductive film coating solution is applied.
[0009]
In this way, The ratio of methanol to ethanol (methanol / (methanol + ethanol)) is 5 to 80 wt%, and the ratio of water to methanol and ethanol (water / (water + organic solvent)) is 1.5 to 21.0 wt%. A solvent consisting of methanol, ethanol, and water In , Formulated so that Sn / (Sn + In) is 1.0 to 13.0% in terms of moles of indium (In) and tin (Sn). Indium chloride and stannous chloride Dissolve a mixture of 1.5 to 7.0 wt% , further Of hydrochloric acid, chloroauric acid, palladium chloride, ruthenium chloride, chloroplatinic acid, zinc chloride, titanium coupling material, metal alkoxide or aluminum coupling material Selected from Any one or more Add the additive To prepare a coating liquid for the transparent conductive film, spray the transparent conductive film coating liquid with a spray nozzle, 200-300 ° C Preheat the coating solution of the transparent conductive film atomized in the preheating atmosphere heated to the temperature, 300-350 ° C It is applied to a substrate heated to a temperature of. As a result, it is possible to suppress the decrease in the substrate temperature and to form a transparent conductive film that is homogeneous with respect to a large substrate.
[0016]
The preheating atmosphere is formed between the substrate and the spray nozzle. Thereby, the coating liquid is preheated between the substrate and the spray nozzle.
[0018]
The spray nozzle introduces and jets a high-speed gas into an internal mixing chamber provided inside, sucks the coating liquid from a coating liquid inlet that communicates with the internal mixing chamber, and sprays the coating liquid on the high-speed jet The gas is crushed, atomized and sprayed. As a result, the coating liquid is sucked from the coating liquid inlet that communicates with the internal mixing chamber by the high-speed gas that is introduced and sprayed into the internal mixing chamber, and the coating liquid is crushed, atomized, and sprayed by the gas that is sprayed at high speed.
[0019]
Moreover, the coating liquid for the transparent conductive film according to the present invention is a coating liquid for the transparent conductive film in which a mixture of indium chloride and stannous chloride is dissolved in a solvent, The ratio of methanol to ethanol (methanol / (methanol + ethanol)) is 5 to 80 wt%, and the ratio of water to methanol and ethanol (water / (water + organic solvent)) is 1.5 to 21.0 wt%. A solvent consisting of methanol, ethanol, and water In , Formulated so that Sn / (Sn + In) is 1.0 to 13.0% in terms of moles of indium (In) and tin (Sn). Indium chloride and stannous chloride Of 1.5 to 7.0 wt% of the mixture , further Of hydrochloric acid, chloroauric acid, palladium chloride, ruthenium chloride, chloroplatinic acid, zinc chloride, titanium coupling material, metal alkoxide or aluminum coupling material Selected from Any one or more Add the additive It is a thing.
[0020]
Thereby, the blending ratio of methanol to ethanol (methanol / (methanol + ethanol)) is 5 to 80 wt%, and the blending ratio of water to the methanol and ethanol (water / (water + organic solvent)) is 1.5 to 21.0 wt%. % In a solvent consisting of methanol, ethanol, and water, Sn / (Sn + In) in terms of moles of indium (In) and tin (Sn) 1.0-13.0% Indium chloride and stannous chloride mixed so that Of 1.5 to 7.0 wt% of the above mixture in the above solvent , further Of hydrochloric acid, chloroauric acid, palladium chloride, ruthenium chloride, chloroplatinic acid, zinc chloride, titanium coupling material, metal alkoxide or aluminum coupling material Selected from Any one or more Coating solution for transparent conductive film prepared by adding additives Therefore, it is possible to form a transparent conductive film that is highly conductive with respect to a large substrate and has no white turbidity over the entire surface.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is an explanatory view showing a method of forming a transparent conductive film according to the present invention. This method of forming a transparent conductive film is intended to suppress the decrease in the substrate temperature and enable a uniform transparent conductive film to be formed on a large substrate. The substrate 1 is heated to a predetermined temperature, and the substrate is heated. 1 is sprayed with a coating liquid of a transparent conductive film by a spray nozzle 2, and the coating liquid of the transparent conductive film atomized thereby is preheated through a preheating atmosphere 6 heated to a predetermined temperature in advance, Heated On board 1 Preheated A coating liquid for transparent conductive film is applied.
[0027]
More specifically, first, the substrate 1 such as a transparent glass is placed on the placement portion 4 on the upper portion of the heating means 3. The substrate 1 is heated to about 300 to 350 ° C. by the heating means 3. Next, the space between the substrate 1 and the spray nozzle 2 is preheated to about 200 to 300 ° C. by the preheating means 5 made of, for example, an infrared lamp or the like, and a preheating atmosphere 6 is created. The preheating atmosphere 6 may be any temperature that can compensate for the decrease in the temperature of the substrate 1 when the coating liquid is sprayed onto the substrate 1.
[0028]
In such a state, for example, indium chloride (InCl _Three ・ 4H ₂ O) 4.22wt% and stannous chloride (SnCl ₂ ) The coating liquid obtained by dissolving 0.17 wt% in a mixed solution of pure water 13.16 wt%, methanol 54.96 wt%, ethanol (anhydrous) 27.48 wt% is atomized from the spray nozzle 2 to the surface of the substrate 1 Sprayed on. At this time, as shown in FIG. 2, the spray nozzle 2 keeps the upper surface of the substrate 1 at a distance of 120 mm between the substrate surface and the tip of the nozzle, and the horizontal width W is 200 mm and the stroke width d is 100 mm / sec. The coating solution is uniformly applied over the entire surface of the 160 mm square substrate 1 while performing zigzag scanning of 10 mm.
[0029]
As shown in FIG. 3, the spray nozzle 2 introduces a high-speed gas into an internal mixing chamber 10 provided in the spray nozzle 2 and injects it, and a coating liquid inlet 7 communicated with the internal mixing chamber 10. The coating liquid is sucked more, and the coating liquid is crushed and atomized with a gas that is jetted at high speed, and the high-pressure gas flows from the high-pressure gas inlet 8 into the axial center of the spray nozzle 2 and has a small diameter. High-speed jetting is performed through the primary gas jetting port 9 and enters the internal mixing chamber 10. At this time, a negative pressure P is generated at the position of the coating liquid inlet 7 due to the principle of the Venturi tube. Here, when the coating liquid is supplied from the coating liquid supply tank (not shown) to the coating liquid inlet 7, the coating liquid is sucked into the internal mixing chamber 10 from the coating liquid inlet 7. The high-speed gas ejected from the primary gas outlet 9 crushes the coating liquid sucked from the coating liquid inlet 7, is mixed with the coating liquid in the widened internal mixing chamber 10, and is sprayed at a reduced flow rate. Injected from the nozzle 11 at the tip of the nozzle 2. In order to perform spraying of the coating liquid continuously, a positive pressure is applied to the coating liquid supply tank by a positive pressure supply means (not shown), and against the negative pressure P at the coating liquid inlet 7 shown in FIG. This can be achieved by adjusting the pressure at the upper surface of the coating liquid supply tank so as to always increase by a predetermined pressure.
[0030]
On the other hand, as shown in FIG. 4, the high-pressure gas that has flowed into the spray nozzle 2 from the high-pressure gas inlet 8 passes through the secondary gas passage 12 formed outside the axial center in the spray nozzle 2, It reaches the secondary gas ejection groove 13 formed in a spiral shape at the tip of the spray nozzle 2 and is ejected as a high-speed swirling flow. At this time, the high-pressure gas is crushed and finely sprayed forward while secondarily mixing the coating liquid ejected from the ejection port 11. In addition, although the example of the spray nozzle which generate | occur | produces a swirl flow was shown in FIG.3 and FIG.4, this invention is not limited to this, The normal spray nozzle which does not generate | occur | produce a swirl flow may be used.
[0031]
The fine particles of the solution sprayed from the spray nozzle 2 are heated in the course of passing through the preheating atmosphere 6 shown in FIG. 1, and are heated on the surface of the substrate 1 heated to about 200 to 300 ° C. which is substantially the same as the preheating atmosphere. Adhere to. Then, indium chloride and stannous chloride are hydrolyzed on the surface of the substrate 1 and further thermally decomposed to form a transparent conductive film of indium-tin oxide (ITO).
[0032]
As described above, the coating liquid for the transparent conductive film is crushed by the high-speed gas by the spray nozzle 2, and is atomized and sprayed. Moreover, the spray amount can be controlled by adjusting the pressure balance between the negative pressure P at the coating liquid inlet 7 of the spray nozzle 2 shown in FIG. 3 and the pressure above the liquid level of the coating liquid supply tank (not shown). Therefore, the coating liquid can be uniformly applied even to a large substrate. Moreover, since the coating liquid of the transparent conductive film preheated in the preheating atmosphere 6 is attached to the heated substrate 1, the temperature of the substrate 1 at the time of spraying the coating liquid is applied to any part of the large substrate. Can be held constant. Therefore, it is possible to form a uniform ITO transparent conductive film while maintaining a constant rate of hydrolysis of indium chloride and stannous chloride over the entire surface of the large substrate. Can be suppressed.
[0033]
Next, the coating liquid for the transparent conductive film used in the method for forming a transparent conductive film according to the present invention will be described. This coating solution of transparent conductive film is intended to enable the formation of a homogeneous ITO transparent conductive film on a large substrate, and a mixture of indium chloride and stannous chloride is mixed at a predetermined blending ratio. The mixture of indium chloride and stannous chloride is Sn / (Sn + In) in terms of moles of indium (In) and tin (Sn). )But 1.0-13.0% Indium chloride and stannous chloride are blended so that The mixing ratio of divalent tin is 1.0% Is smaller, the electron carrier concentration is low and the resistance value is high, 13.0% Higher than that, tin oxide precipitates at the grain boundary and the resistance value increases, and in either case, a high-quality transparent conductive film cannot be formed.
[0034]
Such a mixture of indium chloride and stannous chloride is dissolved in the solvent so that the blending ratio is 1.5 to 7.0 wt%. Here, when the blending ratio is less than 1.5 wt%, it becomes difficult to form a uniform transparent conductive film because the thickness of the transparent conductive film formed by one application becomes too thin, and when it exceeds 7.0 wt%, ITO Unevenness occurs in the formation of the transparent conductive film, causing defects in the film and increasing the resistance value.
[0035]
As the solvent, Methanol and ethanol The ratio of water to water (water / (water + organic solvent)) is preferably 1.5 to 21.0 wt%. Thus, by actively adding water, hydrolysis of indium chloride can be promoted to generate indium oxide, and a uniform ITO transparent conductive film can be formed on a large substrate of 160 mm square or more. Allows formation. However, when the mixing ratio of water is less than 1.5 wt%, hydrolysis of indium chloride does not proceed effectively and it is difficult to obtain a uniform transparent conductive film. Conversely, when it exceeds 21.0 wt%, the transparent conductive film is caused by excess moisture. Pinholes and cracks are generated on the surface, and a high-quality transparent conductive film cannot be formed.
[0036]
Also , Me The blending ratio of ethanol to methanol (methanol / (methanol + ethanol)) is adjusted to 5 to 80 wt%. When the blending ratio of ethanol is less than 5 wt% or more than 80 wt%, the more the number of repeated repeated coatings increases, the more white turbid portions occur, making it difficult to obtain a homogeneous transparent film.
[0037]
Furthermore, the coating liquid includes hydrochloric acid, chloroauric acid, palladium chloride, ruthenium chloride, chloroplatinic acid, zinc chloride, titanium coupling material, metal alkoxide (silicon, titanium, aluminum, zirconium, tin, indium, iron) or Any one or more of the aluminum coupling materials But Addition Has been The in this case, The addition of hydrochloric acid contributes to improving the conductivity of the transparent conductive film. Chloraulic acid, palladium chloride, ruthenium chloride, chloroplatinic acid, zinc chloride, titanium coupling materials, metal alkoxides (silicon, titanium, aluminum, zirconium, tin Indium, iron) and aluminum coupling materials are effective in improving the conductivity and increasing the thickness of the ITO film.
[0038]
Thus, the coating liquid for the transparent conductive film according to the present invention is suitable for the case of applying by spraying with a spray nozzle by determining the blending ratio of each composition material as described above. In addition, the coating liquid of the transparent conductive film is not limited to the case of applying using the above-mentioned spray nozzle, but may be applied using a dip coating method or a conventional spray nozzle that compresses and sprays with high-pressure gas. However, it is more preferable to use the above-described spray nozzle that pulverizes the coating liquid with a gas that is sprayed at a high speed, atomizes the coating liquid, and sprays the coating liquid in a uniform manner.
[0039]
【Example】
Specific examples will be described below.
[Example 1]
First, stannous chloride (SnCl) is added to a solvent in which 41 g of methanol, 41 g of ethanol and 13 g of pure water are mixed. ₂ ) 0.170g and stannic chloride (SnCl ₄ ) For 0.234 g, 4.2 g of each of indium (In) octylate, acetylacetonate, nitrate or hydrochloride was dissolved to prepare 8 types of coating solutions. As a specific production method, a stirring peller coated with Teflon (registered trademark) was inserted into a three-necked flask, and methanol, ethanol, and pure water were poured in this order while refluxing with a water-cooled condenser. Subsequently, while stirring by rotating the stirring blade at 70 rpm at 25 ° C., the indium salt and the tin salt were added in this order, and the mixture was stirred for 15 minutes. Spray liquid It was.
[0040]
As shown in FIG. 1, the preheated atmosphere 6 preheated to 200 ° C. is applied to the 160 mm square transparent glass substrate 1 heated to 350 ° C. by the spray nozzle 2 as shown in FIG. A transparent conductive film was produced by passing through and spraying. And as a result of evaluating about the transparency of the produced film | membrane, as Table 1 shown in FIG. 5, stannous chloride (SnCl ₂ ) Or stannic chloride (SnCl _Four ) And indium hydrochloride (InCl _Three ), A uniform transparent ITO conductive film was obtained (see the circle in the same table), but other indium octylates, acetylacetonates, and nitrates could form films. It was not possible (see the x mark in the same table). For conductivity, stannous chloride (SnCl ₂ ), The specific resistance is 3.5 × 10 ^-Four Although it was very low as Ωcm, stannic chloride (SnCl _Four ) Has a specific resistance of 6.1 × 10 ^-2 It became large with Ωcm.
[0041]
[Example 2]
Next, 4.2 g of indium chloride and divalent tin (Sn) octylate, nitrate, acetate, oxalate, sulfate, hydrochloride or SnO · xH with respect to the solvent of Example 1 ₂ Seven kinds of coating solutions were prepared by dissolving one of the zero. Here, the added amount of the Sn salt is Sn / (Sn + In) in terms of mole of In and Sn. 0.005-0.2% It was made to change so that it might become. The seven types of coating liquid forming methods were performed in the same manner as in Example 1. And as a result of evaluating by the transparency of a film | membrane like Example 1, as shown in Table 2 shown in FIG. 6, divalent tin hydrochloride (SnCl ₂ ), A uniform transparent conductive film was obtained (see circles in the same table), but films of divalent tin octylate, nitrate, acetate, oxalate, and sulfate can be formed. (Refer to x in the table). SnO xH ₂ For 0, a film was formed but a cloudiness phenomenon occurred (see Δ in the table). Furthermore, the divalent tin hydrochloride (SnCl ₂ ), Sn / (Sn + In) is 0.01-0.13% In this case, a high-quality transparent conductive film with high conductivity was obtained, but Sn / (Sn + In) was 0.01% Less than or 0.13% When the amount is larger than the above, the resistance value of the film becomes high, which is insufficient as a conductive film.
[0042]
Example 3
Next, a mixture of 4.2 g of indium chloride and 0.20 g of stannous chloride was added to ion-exchanged water (pure water), methanol, ethanol, isopropanol, butanol, diacetone alcohol, propylene glycol monomethyl ether, isopropyl glycol, methyl cellosolve, butyl cellosolve. , Dimethylformamide, N-methylpyrrolidone, acetone, glycerin, ethylene glycol, diethylene glycol, and methyl ethyl ketone were dissolved in one solvent to prepare 18 types of coating solutions. And it carried out similarly to Example 1, the transparent conductive film was produced about the said 18 types of coating liquid, and the transparency of the film | membrane was evaluated. As a result, as shown in Table 3 shown in FIG. 7, although a transparent conductive film was obtained for ion-exchanged water (pure water), methanol, and ethanol (see the circles in the same table), isopropanol, butanol, Diacetone alcohol, propylene glycol monomethyl ether, isopropyl glycol, methyl cellosolve, butyl cellosolve, dimethylformamide, N-methylpyrrolidone, glycerin, ethylene glycol, propylene glycol monomethyl ether, diethylene glycol, and methyl ethyl ketone cannot be formed. (Refer to x in the table). As for acetone, a white turbidity occurred in some of the membranes that could be produced (see Δ in the same table).
[0043]
Here, when ion exchange water (pure water), methanol, and ethanol were examined in more detail, in the case of only ion exchange water (pure water), fine pinholes and microcracks were generated, and the transparent conductive film As it was insufficient. In the case of ethanol or methanol alone, a transparent conductive film can be formed, but when repeatedly applied, film defects such as white turbidity occur in part as the number of repetitions increases, resulting in the formation of a thick transparent conductive film. It was difficult.
[0044]
Example 4
Based on the results of Example 3, ion-exchanged water (pure water), a mixture of methanol and ethanol were studied. Particularly, here, the coating liquid was prepared by changing the blending ratio (water / (water + organic solvent)) of ion-exchanged water (pure water) to the mixed liquid of methanol and ethanol. Specifically, the composition of ion-exchanged water (pure water) was changed to 0 to 30 wt% with respect to 70 g of methanol and 30 g of ethanol. Then, a transparent conductive film was formed in the same manner as in Example 1. As a result, a high-quality transparent conductive film could be formed over the entire 160 mm square glass substrate at the blending ratio of 1.5 to 21.0 wt%. When the blending ratio is less than 1.5 wt%, film defects such as inability to form a film partially occur. When it exceeds 21.0 wt%, only ion-exchanged water (pure water) is used. Similarly, pinholes and microcracks occurred in the transparent conductive film.
[0045]
Example 5
Next, indium chloride (InCl _Three ) 4.2g, stannous chloride (SnCl ₂ ) 0.2 g, ion exchange water (pure water) 10 g, and the mixing ratio of methanol to ethanol (methanol / (methanol) while maintaining the mixing ratio of ion exchange water (pure water) to the mixture of methanol and ethanol at 10 wt%. + Ethanol)) was changed from 0 to 100 wt% to prepare a coating solution. Then, a transparent conductive film was formed in the same manner as in Example 1. As a result, it was possible to form a high-quality transparent conductive film that can withstand repeated coating when the methanol blending ratio is 5 to 80 wt%. However, when the blending ratio is less than 5 wt%, the properties of ethanol alone appear and white turbidity occurs in part, and a uniform transparent film cannot be formed. On the other hand, when the blending ratio is more than 80 wt%, the properties of methanol alone appear and the repeated coating is difficult.
[0046]
Example 6
Next, indium chloride (InCl _Three ) 4.2g and stannous chloride (SnCl ₂ ) 0.2 g is dissolved in 10 g of ion-exchanged water (pure water), 55 g of methanol and 27 g of ethanol in a mixed solvent, and 3 g of one of hydrochloric acid, sulfuric acid, nitric acid, oxalic acid, acetic acid and octylic acid is added. A coating solution was prepared by addition. Indium chloride (InCl _Three ), Stannous chloride (SnCl ₂ ), Ion exchange water, methanol and ethanol in the same amount as above, chloroauric acid, palladium chloride, ruthenium chloride, chloroplatinic acid, silver nitrate, zinc chloride, titanium coupling material, metal alkoxide (silicon, titanium, aluminum, zirconium) , Tin, indium, iron), and 0.1 g of an aluminum coupling material were added to prepare a coating solution. In the same manner as in Example 1, 14 types of transparent conductive films were formed. As a result, as shown in Table 4 shown in FIG. 8, hydrochloric acid, chloroauric acid, palladium chloride, ruthenium chloride, chloroplatinic acid, zinc chloride, titanium coupling material, metal alkoxide (silicon, titanium, aluminum, zirconium, tin, Indium, iron), and aluminum coupling materials were added, and a high-quality transparent conductive film could be produced (see circles in the same table). In particular, in the case of hydrochloric acid, it effectively works to improve conductivity, and the specific resistance is 1.5 × 10 at a film thickness of 171 nm. ^-Four A transparent conductive film having a low resistance of Ωcm was obtained. Additives of chloroauric acid, palladium chloride, ruthenium chloride, chloroplatinic acid, zinc chloride, titanium coupling material, metal alkoxide (silicon, titanium, aluminum, zirconium, tin, indium, iron), aluminum coupling material In the case, the specific resistance is 1.8 × 10 at a film thickness of about 200 to 230 nm. ^-Four ~ 2.3 × 10 ^-Four It was about Ωcm, which contributed to improving the conductivity of the film and increasing the thickness (see Table 4). On the other hand, membranes could not be formed for sulfuric acid, nitric acid, oxalic acid, acetic acid, octylic acid, and silver nitrate (see x in the table). In addition, chloroauric acid, palladium chloride, ruthenium chloride, and chloroplatinic acid can be expected to lower the firing temperature together with the above effects.
[0047]
【The invention's effect】
Since this invention was comprised as mentioned above, according to the formation method of the transparent conductive film which concerns on Claim 1, it is also with respect to a large sized board | substrate. High conductivity and no cloudiness over the entire surface Enables the formation of a homogeneous ITO film, Moreover, by repeated coating Thick film Formation of Can be made possible.
[0053]
Also, Claim 2 According to the invention concerning, the coating liquid can be preheated between the substrate and the spray nozzle. Therefore, there is no possibility that the coating liquid crystallizes in the spray nozzle.
[0055]
Furthermore, claim 3 According to the invention, the coating liquid is sucked from the coating liquid inlet that communicates with the internal mixing chamber by the high-speed gas that is introduced into and sprayed into the internal mixing chamber, and the coating liquid is crushed with the gas that is sprayed at high speed to form fine particles. Can be sprayed. Accordingly, the transparent conductive film can be uniformly applied to the large substrate, and wasteful consumption of the coating liquid can be prevented.
[0056]
And claim 4 According to the coating liquid of the transparent conductive film according to Guidance High electrical conductivity and no cloudiness over the entire surface Homogeneous ITO film Form of Enable Moreover, it is possible to form a thick film by repeated coating can do.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing a method for forming a transparent conductive film according to the present invention.
FIG. 2 is an explanatory diagram showing scanning of a spray nozzle.
FIG. 3 is a central longitudinal sectional view of the spray nozzle.
4 is a central longitudinal sectional view in a direction orthogonal to the cross section of FIG. 3;
FIG. 5 is a table showing combinations of In salt raw materials with respect to stannous chloride or stannic chloride as an example of synthesis of a coating solution for an ITO transparent conductive film.
FIG. 6 is a table showing combinations of divalent Sn salt raw materials as examples of coating liquid synthesis of an ITO transparent conductive film.
FIG. 7 is a table showing combinations of solvent raw materials as an example of synthesis of a coating solution for an ITO transparent conductive film.
FIG. 8 is a table showing combinations of raw materials for additives as an example of synthesis of a coating solution for an ITO transparent conductive film.
[Explanation of symbols]
1 ... Board
2 ... spray nozzle
6 ... Preheating atmosphere
7 ... Coating liquid inlet
10 ... Internal mixing chamber

Claims (4)

The ratio of methanol to ethanol (methanol / (methanol + ethanol)) is 5 to 80 wt%, and the ratio of water to methanol and ethanol (water / (water + organic solvent)) is 1.5 to 21.0 wt%. methanol, ethanol, and the solvent comprising water, on a molar basis of indium (in) and tin (Sn), Sn / (Sn + in) is a mixture of indium and stannous chloride were blended so that 1.0 to 13.0% It was dissolved by 1.5～7.0Wt%, further hydrochloric acid, chloroauric acid, palladium chloride, ruthenium chloride, chloroplatinic acid, zinc chloride, titanium coupling agent, one selected from among the metal alkoxide or an aluminum coupling agent One or more additives are added to prepare a transparent conductive film coating solution,
Spray the coating liquid of the transparent conductive film with a spray nozzle on a substrate heated to a temperature of 300 to 350 ° C. ,
The preliminarily heated preheated atmosphere that has been heated to a temperature of 200 to 300 ° C. is preheated through the atomized transparent conductive film coating liquid,
A method for forming a transparent conductive film, comprising applying the preheated transparent conductive film coating liquid to the heated substrate.   The method for forming a transparent conductive film according to claim 1, wherein the preheating atmosphere is formed between the substrate and the spray nozzle.   The spray nozzle introduces and jets a high-speed gas into an internal mixing chamber provided therein, sucks the coating liquid of the transparent conductive film from a coating liquid inlet that communicates with the internal mixing chamber, 2. The method for forming a transparent conductive film according to claim 1, wherein the coating liquid is crushed with the gas jetted at high speed, atomized and sprayed. A coating liquid for a transparent conductive film in which a mixture of indium chloride and stannous chloride is dissolved in a solvent,
The ratio of methanol to ethanol (methanol / (methanol + ethanol)) is 5 to 80 wt%, and the ratio of water to methanol and ethanol (water / (water + organic solvent)) is 1.5 to 21.0 wt%. methanol, ethanol, and the solvent comprising water, on a molar basis of indium (in) and tin (Sn), Sn / (Sn + in) is a mixture of indium and stannous chloride were blended so that 1.0 to 13.0% was dissolved only 1.5～7.0Wt% in the solvent is selected further hydrochloric, chloroauric acid, palladium chloride, ruthenium chloride, chloroplatinic acid, zinc chloride, titanium coupling agent, among the metal alkoxide or an aluminum coupling agent the coating liquid of the transparent conductive film, characterized in that the one in which the addition of any one or more additives.

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