JPH06325637A - Transparent conductive coating film forming application liquid and low reflecting transparent conductive film - Google Patents

Abstract

PURPOSE:To provide an application liquid of low viscosity and excellent in conductivity and further to improve light transmissive and mechanical strength of a transparent conductive film using this application liquid by constituting it by containing an organic indium compound, organic tin and an organic solvent. CONSTITUTION:An organic indium compound of selecting at least one kind of acetylacetone indium and indium octilate and organic tin of selecting at least one kind of acetylacetone tin and octyl acid tin are used in a transparent conductive film forming application liquid. As an organic solvent, an acetylacetone solution or the like with dissolved alkylphenol and/or alkenyl phenol is used by selecting at least one kind of liquid diluted by alcohol. In this way, an application liquid excellent in transparency with low viscosity and good wettability to a glass substrate is obtained. By using this application liquid, since a transparent conductive film excellent in mechanical strength with low reflection can be formed, the film can be effectively used in an electric field shield of a CRT or the like and electrostatic prevention.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating liquid for forming a transparent conductive film for shielding an electric field, particularly a coating liquid for forming a transparent conductive film, which is used for forming a transparent conductive film by coating on a glass surface such as CRT. And a low-reflection transparent conductive film formed on a glass surface using this coating solution.

[0002]

2. Description of the Related Art As an ink for forming an antistatic film on the surface of a cathode ray tube of a display or a television, an ATO (tin-antimony oxide) sol-gel ink has been mainly put into practical use. A surface resistance value of about 10 ¹¹ Ω / □ is required for countermeasures against static electricity, but this level is a level that ATO can sufficiently cope with.

In recent years, however, there has been growing interest in the influence of electromagnetic fields generated from CRTs on the human body, mainly in Europe, and guidelines have already been established in some countries including Sweden. Regulations have not been reached in the United States and Japan, but countermeasures are being considered. It is said that the leakage magnetic field can be solved by devising a device, but the correspondence to the electric field is not uniform.

As a method of shielding the electric field on the surface of the CRT, there is a method of fitting a glass on which an ITO film is formed on the glass surface of a CRT cathode ray tube by a vapor deposition or sputtering method, or a method of fitting a plastic panel, which is put into practical use for a limited field. Has been done. Since this method can sufficiently reduce the resistance, it is satisfactory in performance, but it has not been widely put into practical use due to the high manufacturing cost.

From such a background, a method of forming a conductive film by coating has been studied. In this method, for example, a solution of an organometallic compound is applied to a substrate and then heated and baked to form a conductive film. According to the coating method, there is an advantage that large-scale equipment and a large-scale production are easy without requiring large-scale equipment.

Japanese Patent Publication No. 57-138108 discloses an alcohol compound, a cellosolve compound, a carbitol compound, and a glycol compound, which contain an indium compound, a tin compound and a solvent.

In Japanese Patent Publication No. 61-26679, an organic indium compound containing an acetylacetone group, an organic tin compound represented by [Y] ₂ Sn [X] ₂ and an organic solvent are contained, and methyl ethyl ketone is used as an organic solvent. Ethyl acetate and benzene are disclosed.

Further, JP-A-4-255768 discloses a coating solution containing indium nitrate, an organic tin compound, hexylene glycol, and acetic acid and / or acetic anhydride.

Further, JP-A-57-36714 discloses an organic compound having a coordination ability, which comprises an inorganic indium compound, an organic compound having a coordination ability, a tin compound, a viscous agent such as cellulose, and a solvent. Carboxylic acids,
Carboxylic acid esters and hydroxy acids are disclosed.

Further, JP-A-57-212268 discloses a paste composition comprising an indium compound, a tin compound, an organic solvent and a cellulose compound.

Further, Japanese Patent Publication No. 63-25448 discloses a composition containing an indium compound, a tin compound for adjusting a resistance value, nitrocellulose as a viscous agent, and cellsolve, carbitol, benzyl acetate, dimethyl phthalate as a solvent. Has been done.

Further, Japanese Patent Publication No. 2-20706 discloses that
A composition containing indium triacetonate, tin bisacenalacetonate, a cellulose compound, and high boiling alcohols is disclosed.

In Japanese Patent Publication No. 63-19046, a paste containing an indium compound such as indium triacetylacetonate, an organotin complex such as dimethyltinacetove, a viscous agent, and an organic solvent is added with a monoazo organic compound. Disclosed compositions are disclosed.

[0014]

The coating liquid for forming a transparent conductive film is, in short, a paste obtained by adding organic or inorganic conductive fine particles to an organic solvent. The film formability, conductivity, transparency, and mechanical strength of the conductive film depend on the selected conductive particles such as type, property, particle size, addition amount, and organic solvent property. It can be said that the selection of the combination was a repetition of trial and error, since the film characteristics are determined by the interaction with and.

Further, since the viscosity of the coating liquid increases with the amount of cellulose contained in the organic solvent, cellulose is added to the coating liquid used for film formation by spin coating, which requires low viscosity. Not yet Japanese public Sho 57-13
It is desirable to use the compositions described in JP-A-8108 and JP-B-61-26679. By using such a composition, a transparent conductive thin film can be formed by the spin coating method, but this composition does not always guarantee sufficiently satisfactory film characteristics, and there is room for improvement. There is.

As a problem in the case where a transparent conductive film is formed on a glass substrate, if the coating liquid is applied, heated and baked on the substrate, the conductive film has a gloss,
There is a problem that the screen is difficult to see because it reflects light. In general, there is a technology for applying a low-reflection overcoat in order to eliminate gloss, and a coating liquid with low reflection and high light transmittance, such as a coating liquid containing a silicon alkoxide liquid (alkyl silicate sol liquid), is known. However, such a coating liquid is poorly compatible with the conductive coating liquid, and the film obtained by overcoating the film formed by each of the above coating liquids with an alkyl silicate sol liquid and drying and baking the surface is It is not practical for practical use due to unevenness in the inside and unevenness, or uneven streaks.

An object of the present invention is to provide a coating liquid for forming a transparent conductive film having a low viscosity and excellent conductivity, and a low reflective transparent conductive film excellent in light transmittance and mechanical strength using this liquid. To do.

[0018]

In order to achieve the above object, in the coating liquid for forming a transparent conductive film according to the present invention, a transparent conductive film containing an organic indium compound, an organic tin, and an organic solvent is formed. In the coating liquid, at least one of indium acetylacetone indium and indium octylate is selected as the organic indium compound, and at least one of acetylacetone tin and tin octylate is selected as the organic tin. The organic solvent is at least one selected from an acetylacetone solution in which an alkylphenol and / or an alkenylphenol is dissolved, and a solution in which an acetylacetone solution in which an alkylphenol and / or an alkenylphenol is dissolved are diluted with alcohol.

The coating liquid for forming a transparent conductive film according to the present invention is a coating liquid for forming a transparent conductive film containing hydroxypropyl cellulose, wherein hydroxypropyl cellulose is all alkylphenol contained in an organic solvent. And / or an equivalent amount of 1.0 to 12.5% by weight of the alkenylphenol amount is substituted.

The low reflective transparent conductive film according to the present invention is a low reflective transparent conductive film comprising a laminated layer of a transparent conductive film and a coating film, wherein the transparent conductive film is for forming the transparent conductive film. The coating film is formed on the substrate by applying the coating liquid, and the coating film is obtained by overcoating the coating liquid containing silicon alkoxide on the transparent conductive film.

[0021]

In the present invention, as organic indium, indium acetylacetonate (AcAcIn) and indium octylate (OctIn) are used. In the examples, the trade name is Nassem indium (Metal Acetylacet).
onate, In 28%, manufactured by Nippon Kagaku Sangyo Co., Ltd., Hope In (In 25%, manufactured by Hope Pharmaceutical Co., Ltd.), bisacetylacetonatodimethyltin (AcAc) as organic tin.
Sn), tin octylate (OctSn), in the examples, trade name Nasem tin (manufactured by Nippon Kagaku Sangyo Co., Ltd.), Nikka octic tin (Stannous Octoate, Sn28)
%, Manufactured by Nippon Kagaku Sangyo Co., Ltd. were used.

Paratertiary butylphenol, octylphenol, nonylphenol and the like can be used as the alkylphenol, and 3 pentadecadecylphenol and the like can be used as the alkenylphenol. As alcohols, cyclohexanol and the like can be used in addition to methyl, ethyl, propyl and butyl alcohol. Of course, the above-mentioned other alcohols may be appropriately added to ethyl alcohol.

The coating solution of the present invention is usually a transparent solution containing the above a) indium compound, b) tin compound, c) alkyl and / or alkenylphenol, d) acetylacetone solution and / or a mixture of acetylacetone and alcohol, or It is a transparent solution in which 1.0 to 12.5 wt% of alkyl and / or alkenylphenol is replaced with hydroxypropyl cellulose. Such a solution is obtained, for example, by stirring these components at room temperature to 150 ° C. for 0.5 to 12 hours. An example of the solution viscosity obtained under the above manufacturing conditions is shown in Table 1. Table 1
The composition of the component indicates wt%. The same applies to the tables below.

[0024]

[Table 1]

The coating liquid of the present invention can be formed into a film by spin coating, spray coating, bar coating and blade coating.

The coating solution of the present invention has satisfactory wettability with a glass substrate, and since the solvent used is a medium boiling point and / or a mixed solution of a medium boiling point and a low boiling point, it is appropriately volatilized during the coating operation. However, the volatilization gives the film-forming component adhesion to the substrate and resistance to overcoat (no generation of grains, no band-shaped pattern, no whitening), and leveling is caused by the residual solvent. A conductive film having a very small value can be obtained.

A) AcAcIn (or OctIn),
b) AcAcSn (or OctSn), c) alkyl and / or alkenylphenol, d) acetylacetone and / or a coating solution of acetylacetone and ethyl alcohol, the coating solution of the present invention has a substrate temperature of 45 to 60 ° C. during the coating operation. Set to. If the temperature is lower than 45 ° C., the coating solution exhibits a cissing phenomenon on the substrate, and if the temperature exceeds 60 ° C., the evaporation rate is high, the surface tension is large, and the film thickness is not uniform.

When the substrate temperature is set to 45 to 60 ° C.,
AcAcIn (or OctIn) + AcAc in coating liquid
When Sn (or OctSn) exceeded 5 wt%, cracks occurred in the film obtained by drying and baking without overcoating the alkyl silicate sol liquid. On the other hand, if it is less than 5 wt%, cissing occurs during the coating operation. However, the film obtained by the 5 wt% coating solution is
There is no inconvenience such as cissing or cracking, and the surface resistance value is 6 KΩ
// was shown.

AcAcIn (or OctI in the coating liquid)
n) + AcAcSn (or OctSn) of 5 wt% or more is applied onto a substrate set at 45 to 60 ° C., and after a few minutes, a coating solution containing silicon aldoxide is overcoated and then dried, The film obtained by firing was excellent in light transmittance and mechanical speed without inconvenience such as cracks.

It is considered that this is because the overcoat layer absorbs shrinkage due to firing of the conductive layer. Thus, the first conductive layer contains a large amount of In and Sn, and thus is formed as a film having good conductivity.

In the coating solution of the present invention, 1.0 to 12.5 wt% of alkyl and / or alkenylphenol is used.
The coating solution in which% is replaced with hydroxypropyl cellulose can be applied uniformly when the substrate temperature during the coating operation is from room temperature to 60 ° C. It was found that when the substitution amount of hydroxypropyl cellulose was less than 1.0 wt%, the flicker phenomenon occurred during coating, and when it exceeded 12.5%, the fired film had a problem of uneven streaks.

In FIG. 1, AcAcIn + AcAcSn = 1
5 wt% (In / Sn = 92/8), paratertiary butylphenol + hydroxypropyl cellulose = 1
A coating solution composed of 5 wt% (phenol / cellulose = 95/5) and 70 wt% of acetylacetone was prepared and diluted with ethyl alcohol to prepare AcAcIn +.
AcAcSn was set to 12.5 wt%, 8 wt%, 5 wt% and 2.5 wt%, and the sheet resistance values of the films obtained by spin-coating, drying and firing are shown.
All the films had no inconvenience such as cracks, were excellent in light transmission and mechanical strength, and had very small in-plane variation.

In FIG. 2, OctIn is used instead of AcAcIn.
Except that OctSn was used instead of AcAcSn,
The results obtained by the same method as in FIG. 1 are shown. As is apparent from FIG. 2, the surface resistance value when the combination of OctIn and OctSn is higher than that when the combination of AcAcIn and AcAcSn. Therefore, AcAc
It is considered that the surface resistance value falls between the characteristics of FIGS. 1 and 2 in an arbitrary combination of In, AcAcSn and OctIn, OctSn. Regarding the surface resistance values of the two layers obtained by applying the coating solution to the film obtained by film formation, drying and baking using a coating solution containing no hydroxypropyl cellulose, it is assumed that they have similar surface resistance values. Conceivable.

[0034]

The present invention will be described in detail with reference to the following examples.

The coating liquid containing silicon alkoxide used for the overcoat was prepared as follows.
That is, 1 gr of 5% hydrochloric acid is added to 5 gr of ethyl silicate 40 (manufactured by Tama Chemical Co., Ltd.) and shaken well. This was cooled and diluted with 9 gr of water with good stirring, and then 110 gr of ethyl alcohol was added to prepare a 4 wt% solution.

(Examples 1 to 3) 150 gr of acetylacetone and 25 gr of tert-butylphenol were added to a three-necked flask equipped with a stir bar, a thermometer and a reflux condenser, and the mixture was heated at 120 to 135 ° C for 0.5 hour. It dissolved with stirring. Then 23gr AcAcIn and 2gr A
cAcSn was added and dissolved at the same temperature for 3 hours. 1μ when cold
m was used for filtration to prepare a coating liquid for forming a transparent conductive film.

Half of the obtained coating liquid was sampled and used as a sample of Example 1, and the other half was diluted with ethanol to obtain AcAcIn + AcAcSn of 8 wt% (Example 2) and 5 wt% (Example 3). Was used as the coating liquid. 150 mm x
A 200 mm × 9 mm blue plate glass substrate was placed in a hot air drying oven at 50 ° C. for 20 minutes to be heated and then set on a spinner, and 10 gr of the coating solution was rotated at a rotation speed of 150 rpm for 2 minutes.
Application was performed for 1 minute, and then 10 gr of a 4 wt% alkyl silicate sol liquid was applied for 1 minute. 1 in a 120 ° C hot air drying oven
After drying for 0 minutes, it was put in a firing furnace, heated from room temperature to 450 ° C. over 1 hour, heated to 450 ° C., and then fired for 30 minutes. The characteristics of the film obtained by taking out at 200 ° C. or lower are as shown in Table 2.

[0038]

[Table 2] Blue plate Glass substrate LT 85.9% H 0.0%

(Examples 4 to 6) O was used instead of AcAcSn.
Table 3 shows the results obtained by using the same material structure and manufacturing method as in Examples 1 to 3 except that ctSn was used.

[0040]

[Table 3] Blue plate Glass substrate LT 85.9% H 0.0%

(Examples 7 to 9) O was used instead of AcAcIn.
Table 4 shows the results of the same material structure and manufacturing method as in Examples 1 to 3 except that ctIn was used.

[0042]

[Table 4] Blue plate Glass substrate LT 85.9% H 0.0%

(Examples 10 to 12) Table 5 shows the results of the same material constitution and manufacturing method as in Examples 1 to 3 except that OctIn was used in place of AcAcIn and OctSn was used in place of AcAcSn. .

[0044]

[Table 5] Blue plate Glass substrate LT 85.9% H 0.0%

(Examples 13 to 22) 120 to 13 of acetylacetone and para-tert-butylphenol were placed in a three-necked flask equipped with a stirring bar, a thermometer and a reflux condenser.
It dissolved while stirring at 5 ° C. for 0.5 hours. Then, a calculated amount of hydroxypropyl cellulose was gradually added and dissolved at the same temperature for 1 hour. 23 gr of AcAcIn (or OctIn) and 2 gr of AcAcSn (or OctSn) were added and dissolved by stirring for 3 hours, and then filtered using a 1 μm filter paper to prepare a coating liquid for forming a transparent conductive film. Characteristics of a film obtained by spin-coating the obtained coating solution by the same method as in Examples 1 to 3 except that the substrate temperature is room temperature [20 ° C.], followed by drying and firing without overcoating. Are shown in Tables 6 and 7.

[0046]

[Table 6]

[0047]

[Table 7]

(Examples 23 to 26) 150 gr of acetylacetone and 25 [1-x] gr in a three-necked flask equipped with a stir bar, a thermometer and a reflux condenser, where x is a substitution ratio of hydroxypropyl cellulose. 0.125,
0.08, 0.05 and 0.10 paratertiary butylphenol were dissolved with stirring at 120-135 ° C. for 0.5 hours. Then, a calculated amount of hydroxypropyl cellulose was gradually added and dissolved at the same temperature for 1 hour. Ac
After adding 23 gr of AcIn and 2 gr of AcAc with stirring and dissolving for 3 hours, the mixture was filtered using a filter paper of 1 μm, and Example 2
3 to 26 coating solutions for forming a transparent conductive film were prepared. The characteristics of the film obtained by spin-coating and over-coating the coating solution thus obtained by spin coating and over-coating in the same manner as in Examples 1 to 3 except that the substrate temperature was room temperature [20 ° C.] and drying and baking the coating solution are shown in Table 8 below. It was shown to.

[0049]

[Table 8] Blue plate Glass substrate LT 85.9% H 0.0%

[0050]

As described above, the coating liquid for forming a transparent conductive film of the present invention has excellent transparency, low viscosity, and good wettability with respect to a glass substrate. Using the coating method, a uniform transparent conductive thin film can be formed on a glass substrate, and since it is well compatible with commonly used coating solutions containing silicon alkoxide, an overcoat is applied to the surface to reduce A transparent conductive film excellent in mechanical strength can be formed by reflection, and an excellent effect can be obtained in electric field shielding such as CRT and electrostatic prevention.

Further, in the present invention, it should be noted that AcAcIn [or OctIn] and AcAc in the coating solution are mixed.
That is, when the total amount of Sn [or OctSn] was 5% by weight, a conductive film having a low resistance and no inconvenience of cracking or repellency was obtained. Therefore, by specifying the component blending amounts, it is possible to form a transparent conductive film having an extremely low viscosity and therefore having excellent spreadability by spin coating, since it is not necessary to add a viscous agent.

[Brief description of drawings]

FIG. 1 is a diagram showing the relationship between the amount of addition of AcAcIn and AcAcSn and the surface resistance value of a film.

FIG. 2 is a diagram showing the relationship between the added amount of OctIn and OctSn and the surface resistance value of the film.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Keiju Koizumi 7-9-4 Nishigotanda, Shinagawa-ku, Tokyo Tohoku Kako Co., Ltd.

Claims (3)

[Claims] 1. A coating liquid for forming a transparent conductive film, comprising an organic indium compound, organic tin, and an organic solvent, wherein the organic indium compound is at least one selected from indium acetylacetone and indium octylate. The organic tin is selected from at least one of acetylacetone tin and tin octylate, and the organic solvent is acetylacetone solution in which alkylphenol and / or alkenylphenol is dissolved, alkylphenol and / or At least one kind of liquid obtained by diluting an acetylacetone solution in which alkenylphenol is dissolved with alcohol is selected, and a coating liquid for forming a transparent conductive film. 2. A coating liquid for forming a transparent conductive film containing hydroxypropyl cellulose, wherein the hydroxypropyl cellulose is 1.0 to 12 out of the total amount of alkylphenol and / or alkenylphenol contained in the organic solvent. The coating liquid for forming a transparent conductive coating film according to claim 1, wherein an equivalent amount of 0.5% by weight is substituted. 3. A low-reflection transparent conductive film comprising a laminate of a transparent conductive film and a coating film, wherein the transparent conductive film is coated with the coating liquid for forming the transparent conductive film according to claim 1 or 2. A low-reflection transparent conductive film, characterized in that the coating film is formed on a substrate by means of, and the coating film is an overcoat of a coating liquid containing silicon alkoxide on the transparent conductive film.