TWI395730B - Indium tin oxide compound coating liquid and its manufacturing method and application - Google Patents

Description

Alkyl indium tin compound coating liquid, and its manufacturing method and application

The present invention relates to a method for producing an alkoxyindium tin compound coating liquid, and more particularly to a method for producing an extremely high purity alkoxyindium tin compound coating liquid.

The synthesis of indium alkoxide (In(OR) ₃ ) has been described in the literature, as described in "J. Indian Chem. Soc. Vol LIII, September 1976, pp. 867-869" for the synthesis of alkoxyin compounds. law. For example, the synthesis of indium tri-isopropoxide is carried out by refluxing anhydrous indium chloride (InCl ₃ , anhydrous) with tripropanol (isopropanol) in the presence of sodium isopropoxide. be made of. Further, the triisopropane indium oxide compound is subjected to alcoholysis to obtain other alkoxyin indium compounds. However, the triisopropane indium oxide compound obtained by this method often contains sodium, which is not accepted by a specific industry; and is not easily dissolved in an organic solvent, which is disadvantageous for coating work.

Other patents describe the synthesis of alkoxide metal compounds by reacting a metal halide with an alcohol in an alkaline environment, as described in the following paragraphs.

A two-step synthesis of alkoxytin compounds (Stannic alkoxide, Sn(OR) ₄ ) is disclosed, for example, in U.S. Patent No. 3,946,056. First, tin chloride (SnCl ₄ ) is reacted with an alkylamine (first step). The product is then reacted with a tertiary alcohol (second step) to produce an alkoxy tin compound. This method is not suitable for the synthesis of an alkoxyindium compound because in the first step, it is an indium chloride/alkylamine complex, which is quite stable and is not easily reacted with an alcohol.

Further, a two-step process for synthesizing organic solvent insoluble metal alkoxides is disclosed in U.S. Patent No. 4,681,959. The method comprises the steps of: reacting a metal halide with an appropriate amount of an alcohol (first step), wherein the hydrogen halide produced can be easily removed; and then the intermediate product is in a specific solvent and an amine environment, and more The alcohol reaction (second step) gives an alkoxy metal compound which is insoluble in the specific solvent, but the resulting salt is soluble in the specific solvent. This patent also discloses a one-step synthesis of organic solvent insoluble metal methoxides. The method comprises the steps of: reacting a metal halide with a suitable amount of an alcohol in a specific solvent and an amine environment. This alkoxy metal compound is insoluble in this particular solvent. Although the examples are all the synthesis of astannic alkoxide, the invention can also be used for the synthesis of an indium alkoxide. However, the alkoxy metal compound obtained by this method is not suitable for a coating operation because it is insoluble in a solvent.

Further, a one-step synthesis of organic solvent-soluble indium alkoxides is disclosed in U.S. Patent No. 5,327,081. The method comprises the steps of: reacting indium chloride (InCl ₃ ) in an organic solvent and a strong base (pKa>10) with an alcohol of C ₃ -C ₂₀ . The reaction medium must be anhydrous; the organic solvent must be a soluble alcohol or a polar solvent; the strong base must be low nucleophilic. However, this method is accompanied by the formation of indium chloride/alkylamine complexes in amounts ranging from 10% to 30%, and even some systems are higher than 90%. Although this mismatch can also be used as a dopant, the amount of formation is not easily controlled, which seriously affects the quality of the coating liquid. This mismatch is quite stable and is not conducive to the conductivity of the coating film.

Some patent documents disclose a method for producing an indium tin oxide (ITO) aqueous solution which can be coated, such as Taiwan Patent No. 538121, U.S. Patent No. 4,594,182, U.S. Patent No. 6,533,966 B1, U.S. Patent No. 6,316,100 B2 Wait. All of these are coating liquids in which an inorganic substance (metal oxide) has been formed, and are not coating liquids of the organic compound disclosed in the present invention. The coating solution of the organic compound is also disclosed by an indium tin organic chelate complex, such as U.S. Patent No. 4,268,539, U.S. Patent No. 4,391,743, and the like. The disclosed indium tin organic chelate complex is a mixture of In(X) _l (Y) _m and Sn(X) ₂ or Sn(Y) _{m '} , wherein X is a β-diketone (such as acetamidine, A chelate ring formed by acetylacetone or an ester thereof (such as methyl acetoacetate), and Y is an alkoxy group formed by an alcohol. These indium tin organic chelate complexes are quite stable, and must be above 550 ° C to decompose the organic material to form an ITO film. Unlike the alkoxyindium tin compound (In(OR) ₃ , Sn(OR) ₄ ) disclosed in the present invention, an ITO film can be formed by a hydrolysis and recondensation reaction with water vapor at a relatively low temperature (50-200 ° C). Meanwhile, the above patent also discloses that there must be 5-20 parts of tin compounds per 100 parts of the indium compound in the indium tin organic chelate compounding solution coating liquid.

Indium tin oxide (ITO) is tin-doped indium oxide, which can be represented by In ₂ O ₃ :Sn, and ITO can be made into a p-type or n-type semiconductor by doping different impurities. ITO belongs to a highly transparent and highly conductive metal oxide film (TCO). ITO is an n-type semiconductor material whose main component is In ₂ O ₃ , and In ₂ O ₃ itself is structurally It is easy to lose oxygen and form oxygen vacancies. Therefore, there are many oxygen vacancies in the process of preparing ITO film. These oxygen vacancies replace the original O ^2- position, and when they lose oxygen atoms, these sites leave negative static electricity. Load (2e ^- ), and produce a donor site. This is why In ₂ O ₃ itself has conductive properties.

On the other hand, when In ₂ O ₃ is added with SnO ₂ , because of In ³⁺ (ion radius is 0.79) ) with Sn ⁴⁺ (ion radius 0.69) ) has a similar ionic radius, so Sn ⁴⁺ replaces In ³⁺ and provides a free electron as the center of the donor. When the amount of tin doping is small, it is mainly in the form of Sn ⁴⁺ and exists in the lattice of the donor body, which can improve the conductivity; when the amount of tin is large, the Sn ^{2+ is} dominant, and the ratio is more than In. ³⁺ less one electron, and become an acceptor site, reducing conductivity. In addition, excessive doping of tin can distort the crystal lattice, reduce the mobility of the carrier, and also reduce the conductivity. It can be seen that the appropriate amount of tin doping can reduce the conductivity of the conductive, and the maximum amount of tin in the different preparation methods is also different. An ITO film is prepared by a sputtering method, and the target used may be an indium tin alloy target or an oxide target obtained by mixing and sintering In ₂ O ₃ and SnO ₂ , usually In :Sn=90:10 (wt.%). If ITO sol is prepared by the sol-gel method, the tin doping amount (Sn/In+Sn) will have an optimum amount to achieve a lower resistivity.

In the manufacture of a metal alkoxide, either a one-step process (US Pat. No. 4,681,959, U.S. Patent No. 5,237,801) or a two-step process (e.g., U.S. Patent No. 3,946,056, U.S. Patent No. 4,681,959) A single component alkoxy metal compound such as an alkoxyin compound or an alkoxy tin compound is produced. The metal oxide formed by the single-component alkoxide metal compound has a low conductivity. At the same time, the alkoxy metal compound produced is not high in purity, and often contains impurities such as indium chloride/alkylamine complex, which cannot be removed at a low temperature, resulting in a serious influence on conductivity. Therefore, the present invention is an alkoxyindium tin compound (In(OR) ₃ , Sn(OR) ₄ which is produced by a two-step method or a three-step method and has a specific tin doping amount (Sn/In+Sn). ) Mix the coating solution. Moreover, the two-step method adopted by the present invention is different from the two-step method of the aforementioned patent (which will be described in detail in the Summary of the Invention), and the two-step method adopted by the present invention can obtain an extremely high purity alkoxyindium tin compound, which is advantageous for Hydrolysis and condensation reaction at low temperature (50~200 °C) with water (added to the coating liquid or in the vapor chamber) to form an impurity-free indium tin oxide (ITO) film, which can obtain a lower resistivity. And more than 90% of the light penetration. It is required to apply a chemical wet method to a general indium-Tin Organic complex solution at 600 ° C or higher.

The shortcomings of the existing technologies are as follows:

1. A method for synthesizing an alkoxy metal compound soluble in a reaction medium but capable of precipitating a salt impurity, which has the disadvantage of producing only a single component alkoxy metal compound, and at the same time easily remaining a salt impurity or an indium halide (tin) / Alkylamines are mismatched and affect quality.

2. A method for synthesizing an alkoxy metal compound by synthesizing insoluble in a reaction medium, which has the disadvantage of producing only a single component alkoxy metal compound, and is insoluble in a reaction medium, and is not suitable for coating work.

3. A method for synthesizing an indium tin organic chelate complex, which is a method for preparing two main components, but the chelate complex must be higher than 550 ° C to decompose the organic material to form an ITO film. .

The present inventors have invented the alkoxyindium tin compound coating liquid and a method for producing the same, after a long period of research and continuous testing, in view of the shortcomings of the prior art of preparing indium tin oxide.

The object of the present invention is to provide an alkoxyindium tin compound coating liquid which is of a very high purity and which is not a single main component containing a specific tin doping amount, and can be hydrolyzed and condensed with water at a low temperature to form an impurity-free substance. Indium tin oxide film.

In order to achieve the above object, the technical means used in the present invention is to provide a method for producing an alkoxyindium tin compound coating liquid, which comprises: a non-aqueous level indium halide (InX ₃ ), a non-aqueous level tin halide (SnX ₄ ) and The alcohol is dissolved in the first solvent according to a specific ratio formula, and the reaction is carried out under a low temperature condition for a certain period of time to form a clear solution, and then the diluted alkali catalyst is slowly added, and the reaction is carried out under a low temperature condition for a while, and the salt is filtered off. After the precipitate was obtained, the alkoxyindium tin compound coating liquid was obtained.

Wherein, after adding the diluted alkali catalyst to the reaction under a low temperature condition for a period of time and filtering off the salt precipitate, the solvent is concentrated and removed, the solvent comprises the first solvent and the unreacted alcohol; The second solvent is added to obtain the alkoxyindium tin compound coating liquid.

Wherein the anhydrous indium halide is selected from the group consisting of anhydrous indium chloride (InCl ₃ , anhydrous) and anhydrous indium bromide (InBr ₃ , anhydrous), The anhydrous grade tin halide is selected from the group consisting of anhydrous grade tin chloride (SnCl ₄ , anhydrous) and anhydrous grade tin bromide (SnBr ₄ , anhydrous).

Wherein the alcohol is selected from the group consisting of the following compounds: a carbon tri-carbon 20 (C3 to C20) mono-alcohol, cyclohexanol, and mixtures thereof.

Preferably, the alcohol is selected from the group consisting of the following compounds: carbon tetra-carbon eight (C4~C8) mono-alcohol, 1-butanol, 1-pentanol, cyclohexanol and Its mixture.

Wherein the first solvent is selected from the group consisting of chloroform, dimethylformamide (DMF), acetonitrile, tetrahydrofuran (THF), Methyl hydrazine (DMSO), acetone, 1,4 dioxane (1,4 dioxane), ethyl acetate, and mixtures thereof.

Preferably, the first solvent is tetrahydrofuran.

Wherein the base-based catalyst is a high pKa value, a low nucleophilicity and a strong base with hindered nitrogen selected from the group consisting of trimethylamine (trimethylamine, TMA), triethylaminq (TEA), 1,1,3,3-tetramethylguanidine (TMG), 1,8-diazabicyclo[5 , 4,0] diazabicyclo[5,4,0]undec-7-ene,DABU), 1,5-diazabicyclo[4,3,0]nonanequine (1, 5-diazabicyclo[4,3,0]non-5-ene,DABN), 1,8-bis(dimethylaminonaphthalene (Proton sponge).

Preferably, the base catalyst is triethylamine.

Wherein, the second solvent is selected from the group consisting of the following compounds: carbon tri-carbon 20 (C3 ~ C20) alcohols and alcohols reacted with indium halides, chloroform, two Methylformamide (DMF), acetonitrile, tetrahydrofuran (THF), dimethylhydrazine (DMSO), acetone, 1,4 dioxane (1,4 dioxane), ethyl acetate, and mixtures thereof .

Wherein, after the salt precipitate is filtered off, a chelating agent is further added to obtain the alkoxyindium tin compound coating liquid, and the chelating agent is selected from the group consisting of the following compounds: β-diketone And its esters.

Wherein, after adding the second solvent to the specific ratio, a chelating agent is added to obtain the alkoxyindium tin compound coating liquid, and the chelating agent is selected from the group consisting of the following compounds: β- Diketones and their esters.

Preferably, the chelating agent is selected from the group consisting of methyl acetoacetate and acetylacetone and mixtures thereof.

More preferably, the chelating agent is acetylacetone.

Wherein, the anhydrous-grade indium halide (InX ₃ ) and the anhydrous-grade tin halide (SnX ₄ ) are based on the anhydrous-grade tin halide, and the total of the anhydrous-grade indium halide and the anhydrous-grade tin halide are 5 to 15 mole. The ratio of % is mixed (ie, the molar percentage of SnX ₄ /(InX ₃ +SnX ₄ )).

Preferably, the anhydrous-grade indium halide and the anhydrous-grade tin halide are mixed according to the anhydrous-grade tin halide in a ratio of 8 to 13 mole% of the total of the anhydrous-grade indium halide and the anhydrous-grade tin halide.

Wherein, the alcohol is used in an amount of from 310 mole% to 600 mole% of the total of the anhydrous grade indium halide and the anhydrous grade tin halide (ie (alcohol) / (anhydrous indium halide +) The molar percentage of anhydrous-grade tin halide).

Preferably, the alcohol is used in an amount of from 380 mole% to 450 mole% of the total of the anhydrous grade indium halide and the anhydrous grade tin halide.

Wherein, the total ratio of the specific ratio of the first solvent is that the first solvent is 320 wt% to 1290 wt% of the anhydrous grade indium halide, the anhydrous grade tin halide and the alcohol. That is (the first solvent) / (anhydrous indium halide + anhydrous grade tin halide + alcohol) by weight).

Preferably, the total ratio of the specific ratio of the first solvent is that the first solvent is 430 wt% of the anhydrous grade indium halide, the anhydrous grade tin halide and the alcohol. 810 wt%.

Wherein, the base catalyst is used in a ratio of 310 to 500 mole% (ie (alkali catalyst) / (the total amount of the anhydrous-grade indium halide and the anhydrous-grade tin halide). The molar percentage of anhydrous grade indium halide + anhydrous grade tin halide).

Preferably, the base catalyst is used in a ratio of 310 to 400 mole% of the total of the anhydrous grade indium halide and the anhydrous grade tin halide.

Wherein the diluted base catalyst is used in a ratio of 10 to 50% by weight of the alkali catalyst or the first solvent, and the amount of the alcohol used and the first The amount of the solvent used is included in the total amount of the aforementioned alcohol and the first solvent.

Wherein, the low temperature condition is -40 ° C ~ 60 ° C.

Preferably, the low temperature condition is from 0 ° C to 10 ° C.

Wherein, the anhydrous-grade indium halide, the anhydrous-grade tin halide and the alcohol are dissolved in the first solvent according to a specific ratio formula, and then reacted under a low temperature condition to form a clear solution; and then the diluted alkali-based catalyst is slowly added, and then The reaction was carried out under low temperature conditions to obtain a large amount of salt precipitation.

Preferably, the anhydrous-grade indium halide, the anhydrous-grade tin halide and the alcohol are dissolved in the first solvent according to a specific ratio, and then reacted at a low temperature for 0.5 hours to form a clear solution, and then slowly added the diluted alkali. The catalyst is reacted under low temperature conditions for more than one hour to obtain a large amount of salt precipitation.

Wherein, the anhydrous grade indium halide, the anhydrous grade tin halide (SnX ₄ ) and the alcohol are dissolved in the first solvent according to a specific ratio formula, and the reaction is carried out under a low temperature condition for a period of time, and then the dilution is completed within half an hour. The step of a base catalyst.

The present invention also relates to an alkoxyindium tin compound coating liquid which is produced by the above-described method for producing an alkoxyindium tin compound coating liquid.

The present invention further relates to an alkoxyindium tin compound coating liquid comprising: an alkoxyindium tin compound, and a second solvent, wherein the alkoxyindium tin compound is dissolved in the solvent by a specific atomic ratio of indium and tin.

Wherein, the alkoxyindium tin compound coating liquid further contains a chelating agent.

Wherein, the chelating agent is methyl acetoacetate, acetylacetone and a mixture thereof.

Among them, the alkoxyindium tin compound is a mixture of an alkoxyindium compound and an alkoxy tin compound.

Preferably, the alkoxyindium tin compound is an alkoxyindium tin compound produced by a anhydrous-grade indium halide, an anhydrous-grade tin halide and an alcohol, and the anhydrous-grade indium halide is selected from the group consisting of the following compounds. Group: anhydrous grade indium chloride (InCl ₃ , anhydrous) and anhydrous grade indium bromide (InBr ₃ , anhydrous), the anhydrous grade tin halide is selected from the group consisting of the following compounds: anhydrous chlorine Tin (SnCl ₄ , anhydrous) and anhydrous grade tin bromide (SnBr ₄ , anhydrous), the alcohol is selected from the group consisting of the following compounds: carbon tri-carbon 20 (C3 ~ C20) a primary alcohol, 1-butanol, 1-pentanol, cyclohexanol, and mixtures thereof; the second solvent is selected from the group consisting of the following compounds: carbon tri-carbon 20 (C3 to C20) Alcohols and alcohols reacted with indium halides, chloroform, dimethylformamide (DMF), acetonitrile, tetrahydrofuran (THF), dimethylhydrazine (DMSO), acetone, 1,4 dioxo Hexacyclic (1,4 dioxane), ethyl acetate and mixtures thereof.

Wherein the alkoxyindium tin compound is selected from the group consisting of 1-butane indium tin oxide compounds, 1-pentane indium tin oxide compounds, cyclohexane indium tin compounds, and mixtures thereof .

The number of tin atoms in the alkoxyindium tin compound is 5 at% to 15 at% (i.e., the atomic percentage of Sn/(Sn+In)) of the total of the number of tin and indium atoms.

Preferably, the number of tin atoms is from 8 at% to 13 at% of the total of the number of tin and indium atoms.

Preferably, the concentration of the chelating agent is from 5 to 300 mole% of the concentration of the alkoxy tin indium compound.

More preferably, the concentration of the chelating agent is from 30 to 100 mole% of the concentration of the alkoxy tin indium compound.

Preferably, the concentration of the alkoxyindium tin compound is 5 wt% to 20 wt% of the alkoxyindium tin compound coating liquid.

More preferably, the concentration of the alkoxyindium tin compound is from 8 wt% to 15 wt% of the alkoxyindium tin compound coating liquid.

The invention further relates to a method for preparing an indium tin oxide film, comprising: providing a substrate; providing an alkoxyindium tin compound coating solution; coating the alkoxyindium tin compound coating solution on the substrate, and The indium tin oxide (ITO) film is obtained by performing hydrolysis and condensation reaction at 50 to 200 ° C to remove the produced alcoholic substance, and residual solvent and chelating agent.

Here, before applying the alkoxyindium tin compound coating liquid to the substrate, the alkoxyindium tin compound coating liquid is diluted with water.

Wherein, after the hydrolysis and condensation reaction, sintering is further carried out, the sintering temperature is greater than 200 ° C, and the sintering time is greater than 30 minutes.

Preferably, the sintering is further carried out after the hydrolysis and condensation reaction, and the sintering temperature is greater than 300 °C.

Preferably, when the alkoxyindium tin compound coating liquid is diluted with water, the amount of water added to the water is 100 to 300 mole% more than the alkoxyindium tin compound.

More preferably, when the alkoxyindium tin compound coating liquid is diluted with water, the amount of water added to the water is 170 to 230 mole% more than the alkoxy tin indium compound.

The alkoxyindium tin compound coating liquid provided by the present invention and the method for producing the same, the advantages and the enhancements obtained by the above technical means include at least:

1. The production method adopted in the present invention can obtain a coating liquid of an alkoxyindium tin compound of extremely high purity.

2. The coating liquid produced by the manufacturing method of the present invention is a coating liquid other than a single main component, but an alkoxyindium tin compound containing a specific tin doping amount (Sn/In+Sn) ( In(OR) ₃ , Sn(OR) ₄ ) Mixed coating solution.

3. The mixed solution of the alkoxyindium tin compound (In(OR) ₃ , Sn(OR) ₄ ) produced by the present invention can be applied to the coating liquid at a low temperature (50 to 200 ° C) or water (or Hydrolysis and condensation reactions are carried out in a vapor chamber to form an impurity-free indium tin oxide (ITO) film, which results in a lower resistivity and a light transmittance of 90% or more. Therefore, it can be used in a large amount on substrates which cannot withstand high temperatures.

Generally, the wet coating method can be carried out by using an indium tin oxide (ITO) aqueous solution or an indium tin organic chelate compound coating liquid (In(X) _l (Y) _m and Sn(X) _{2 .} Or Sn(Y) _m ), and alkoxyindium tin compound (In(OR) ₃ , Sn(OR) ₄ ) mixed coating solution. The indium tin oxide (ITO) aqueous solution disperses the ITO nano particles by using a dispersing agent, and the ITO nano particles are high in cost; the other coating liquid, the indium tin organic chelate compound coating liquid depends on the coating liquid At very high temperatures (above 600 ° C), the organic material can be cracked to form an ITO film; and the solution of the alkoxy tin indium compound in the current patent is limited to the manufacture of a single component alkoxy metal compound, such as an alkoxyin compound or Alkoxy tin compound. The metal oxide formed by the single-component alkoxide metal compound has a low conductivity. At the same time, the alkoxy metal compound produced is not high in purity, and often contains impurities such as indium chloride/alkylamine complex, which cannot be removed at a low temperature, resulting in a serious influence on conductivity.

Therefore, in order to solve the above problems and form a high-purity and high-conductivity indium tin oxide (ITO) film at a lower temperature, it can be used on substrates that cannot withstand high temperatures (such as PET, PI or other plastic substrates). The present invention provides an alkoxyindium tin compound coating liquid, a method for producing the same, and an application thereof.

The method includes: a method for producing an alkoxyindium tin compound coating liquid; and a composition of an alkoxyindium tin compound coating liquid, wherein the alkoxyindium tin compound coating liquid is an atomic ratio designed by indium and tin The alkoxyindium tin compound is dissolved in an organic solvent and applied to a substrate to form indium tin oxide (ITO).

The invention utilizes anhydrous grade indium halide (InX ₃ , anhydrous), anhydrous grade tin halide (SnX ₄ , anhydrous) and alcohol (alcohol) according to a specific stoichiometry, in a specific reaction medium (first solvent), using a base The catalyst is prepared into a high-purity mixed solution of alkane indium tin compound (In(OR) ₃ , Sn(OR) ₄ ) in a two-step manner: or the vacuum solution is removed in a three-step manner to remove the solvent. A high purity alkoxyindium tin compound can be obtained, and a specific concentration of the alkoxyindium tin compound coating liquid can be prepared in a specific solvent (second solvent). When the coating solution of the alkoxyindium tin compound is wet-coated, it can be hydrolyzed and condensed at a lower temperature (50 to 200 ° C) with water (added to a coating liquid or in a vapor chamber) to form a coating solution. An indium tin oxide (ITO) film that releases volatile alcohols. The indium tin oxide (ITO) film obtained from the alkoxyindium tin compound coating liquid is relatively uniform and does not crack. Since the coating liquid can form indium tin oxide (ITO) by a sol-gel method at a lower temperature, an antistatic material can be formed; or it can be sintered to be electrically conductive at 300 ° C. Indium tin oxide (ITO). Therefore, it can be used in a large amount on substrates which cannot withstand high temperatures. If necessary, it can be sintered above 300 ° C, and the sintering time is more than 30 minutes, resulting in a more conductive indium tin oxide (ITO). When it is applied to the chemical wet method with a general Indium-Tin Organic complex solution, it is necessary to have different application conditions of 600 ° C or higher.

The indium tin halide required for preparing the alkoxyindium tin compound coating liquid of the present invention is anhydrous grade indium chloride (InCl ₃ , anhydrous), anhydrous grade tin chloride (SnCl ₄ , anhydrous), or anhydrous indium bromide. (InBr ₃ , anhydrous), anhydrous grade tin bromide (SnBr ₄ , anhydrous).

The alcohol required for preparing the alkoxyindium tin compound coating liquid of the present invention is one which is soluble in a reaction medium (referred to as a first solvent) and which is reactive with indium tin halide. Usually smaller molecules are preferred. However, methanol and ethanol are not suitable because the alkoxyindium tin compound formed is not dissolved in a general solvent. Preferred are cyclohexanol and C ₄ -C ₂₀ primary alcohols such as 1-butanol, 1-pentanol and the like. If the coating operation is to be sintered at 300 ° C, the alcohol can only be selected from C ₄ -C ₈ primary alcohols having a lower boiling point.

The basic catalyst required for the preparation of the alkoxyindium tin compound coating liquid of the present invention has a high pKa value and low nucleophilicity. It is usually a hindered nitrogen strong base. Preferred are trimethylamine (TMA), triethylamine (TEA), 1,1,3,3-tetramethylguanidine (TMG), 1,8-diazabicyclo[5,4,0]undecene (dizabicyclo[5,4,0]undec-7-ene,DABU), 1,5-diazabicyclo[4 , 3,0] pentane (1,5-diazabicyclo[4,3,0]non-5-ene,DABN), 1,8-bis(dimethylamino)naphthalene (1,8-bis(dimethylamino)naphthalene (1,8-bis(dimethylamino)naphthalene (1,8-bis(dimethylamino)naphthalene) Proton sponge))

The reaction medium (first solvent) required for the preparation of the alkoxyindium tin compound coating liquid of the present invention must be compatible with the above selected alcohols and basic catalyst. At the same time, it is preferred to precipitate the salts produced by the reaction, such as HCl.NR ₃ or those produced such as indium chloride/alkylamine complexes. A polar solvent such as chloroform, dimethylformamide (DMF), or a polar solvent which does not have an OH group and does not form a complex with an indium tin halide. Acetonitrile, tetrahydrofuran (THF), dimethylhydrazine (DMSO), acetone, 1,4-dioxane (1,4 dioxane), ethyl acetate, and the like. The reaction medium (first solvent) may be used singly or in combination with each other. Most preferred is tetrahydrofuran (THF).

If a specific solvent (referred to as a second solvent) required for a specific concentration of the alkoxyindium tin compound coating liquid is formulated in a three-step manner, in addition to the above first solvent, the second solvent may be used in the reaction system with indium tin. The halide-reacted alcohol, or other C ₃ -C ₂₀ alcohol, can also be the second solvent.

In particular, it must be emphasized that the chemicals used in the reaction system (indium tin halides, alcohols, alkaline catalysts, first solvent and second solvent) must be free of any moisture.

Reaction steps:

The method for preparing an alkoxyindium tin compound coating liquid according to the two-step method of the present invention comprises a chemical-based dosage of an anhydrous indium halide (InX ₃ , anhydrous) and a nonaqueous anhydrous tin (SnX ₄ , anhydrous) and an alcohol. Stoichiometric amount is carried out in a reaction medium (first solvent), dried under nitrogen and at a low temperature for a period of time (first step), at which time a hydrogen halide is produced. Further, a chemically dosed alkaline catalyst is previously dissolved in the reaction medium (first solvent) to dilute the concentration of the basic catalyst. Then, the diluted alkaline catalyst solution is slowly added to the solution obtained in the first step for a certain period of time (second step), and in addition, the alkaline catalyst can be added to the first step within half an hour. In the resulting solution. At this time, the basic catalyst forms a salt with the hydrogen halide product produced, such as HX.NR ₃ , and precipitates in the reaction medium (first solvent). The salt is removed by filtration to obtain a high purity alkoxyindium tin compound coating liquid. [The second step of the present invention is different from the second step described in the prior patent (U.S. Patent No. 4,681,959). The second step described in the prior patent is to slowly add the solution obtained in the first step to the pure alkaline catalyst. in. This method generates a highly stable indium halide/alkylamine complex due to the instantaneous contact with a large amount of alkaline catalyst, and the amount thereof is between 10% and 30%, and the amount thereof is also difficult to control and difficult to remove, which may seriously affect The quality of the coating liquid is not conducive to the conductivity of the coating film. At the same time, the two-step method disclosed in U.S. Patent No. 4,681,959 is to synthesize organic alkoxides which are insoluble in organic solvents, and this patent is an alkoxy metal compound which is selected from a suitable solvent to be an organic solvent.

In the present invention, the anhydrous-grade indium halide (InX ₃ , anhydrous) and the anhydrous-grade tin halide (SnX ₄ , anhydrous) are mixed at a ratio of the number of Sn atoms/(Sn+In) atoms of 5 to 15 at%. Conductivity; that is, SnX ₄ /(InX ₃ +SnX ₄ ) is mixed at a ratio of 5 to 15 mole%, and it is desired to mix and coat the obtained alkoxyindium tin compound (In(OR) ₃ , Sn(OR) ₄ ). When the ratio of Sn(OR) ₄ /(In(OR) ₃ +Sn(OR) ₄ ) in the liquid is 5 to 15 mole%, a higher conductivity is obtained. SnX ₄ /(InX ₃ +SnX ₄ ) is preferably mixed in a ratio of 8 to 13 mole%.

The amount of the alcohol used in the present invention is substantially the lowest amount calculated based on the stoichiometric amount. The minimum amount of alcohol used is the number of moles of SnX ₄ times 4 times plus the number of moles of InX ₃ multiplied by 3 times. However, in order to make the reaction more complete, and to ensure no SnX ₄ and InX ₃ residues, it is usually appropriate to add alcohol. However, when the amount is too large, the precipitation of HX.NR ₃ salt is disadvantageous. Therefore, the preferred amount of alcohol used is: (alcohol) / (anhydrous indium halide + anhydrous grade tin halide) is 310 mole% to 600 mole%, The best is 380mole%~450mole%.

In the reaction medium (first solvent) of the present invention, the salt produced by the precipitation reaction is preferably the same, and the amount thereof is not limited, but the amount thereof must be sufficient to uniformly dissolve the anhydrous-grade indium halide and the anhydrous-grade tin halide. In order to facilitate the precipitation of HX.NR ₃ salts, a suitable excess of the reaction medium (first solvent) is necessary, but if the amount is too large, the reaction rate is too slow due to the too low concentration of the reaction system, and the obtained alkoxyindium tin The concentration of the compound coating liquid is too low, which is unfavorable. However, if the reaction solvent is too much, the concentration is too low, and some of the solvent may be removed after the reaction is completed to facilitate the operation. Although the amount of the first solvent is not limited, in order to attain the concentration of the active ingredient required (the preferred alkoxyindium tin compound concentration is 5 wt% to 20 wt%, and the optimum concentration is 8 wt% to 15 wt%), preferably The total amount of the first solvent used is (first solvent) / (anhydrous indium halide + anhydrous grade tin halide + alcohol) is from 320 wt% to 1290 wt%, most preferably from 430 wt% to 810 wt%.

The amount of the basic catalyst used in the present invention is substantially the lowest amount calculated based on the stoichiometric amount. The minimum amount of base catalyst moles is SnX ₄ moles multiplied by 4 times plus InX ₃ moles multiplied by 3 times. However, in order to completely remove the halogen element, a suitable excess of the basic catalyst is necessary in order to form a HX.NR ₃ salt and precipitate. However, if the excess is too large, there is a flaw in the formation of a highly stable indium halide/alkylamine complex, which is difficult to remove and seriously affects the quality of the coating liquid. Therefore, it is preferred to use a ratio of (alkali-based catalyst)/(anhydrous indium halide ten anhydrous-grade tin halide) of 310 to 500 mole%, preferably 310 to 400 mole%. When used, it may be mixed in a small amount of the reaction medium (first solvent) or the same alcohol in the reaction system in order to lower the concentration. It is preferred to use a ratio of (base catalyst) / (alcohol or first solvent) of 10 to 50% by weight. The amount of the alcohol or the first solvent used is within the total amount stated above.

The reaction temperature in the present invention is usually between -40 ° C and 60 ° C because the low temperature reaction is less prone to side reactions and less likely to form an indium halide/alkylamine complex. The preferred reaction temperature is from 0 ° C to 10 ° C.

The reaction time of the first step and the second step in the present invention is not particularly limited, and usually the longer the time, the better. However, in the first step, the reaction time must be such that the reaction system becomes a clear solution, and in the second step, at least the reaction time must be observed in the reaction system to precipitate a large amount of salts.

After the completion of the second step reaction, the salt is removed by filtration to obtain a high purity alkoxyindium tin compound solution. In particular, it must be emphasized that any moisture must be isolated during the filtration process. If the solution after the second step is placed in a lower temperature environment (such as a refrigerator), it is more conducive to the precipitation of salts. Therefore, such an operation still falls within the technical scope of the present invention. When the salt is removed by filtration, the resulting high purity alkoxyindium tin compound solution is used as a coating liquid. The mixed solution of the alkoxyindium tin compound (In(OR) ₃ , Sn(OR) ₄ ) obtained by the invention has high sensitivity to moisture, so that for the stability of the coating liquid, β- can be appropriately added. A diketone (such as acetacetone, acetylacetone) or an ester thereof (such as methyl acetoacetatae) chelating agent to stabilize the coating solution for long-term storage, and to obtain the alkoxyindium tin compound coating solution The indium tin oxide (ITO) film is relatively uniform and does not crack. Considering the temperature required to remove the chelating agent, acetonitrile is preferred, and the preferred concentration is acetonitrile to acetone 5 to 300 mole% of the alkoxyindium tin compound; the optimum concentration is 30 to 100 mole%.

In order to consider the coating operation, the two-step method of the present invention prepares an alkoxyindium tin compound coating liquid, which preferably has a concentration of the alkoxyindium tin compound of 5 wt% to 20 wt%. The optimum concentration is 8 wt% to 15 wt%. However, if there are too many solvents, some of the solvent may be removed after the reaction is completed to facilitate the operation.

The method for producing an alkoxyindium tin compound coating liquid according to the three-step method of the present invention comprises a solution prepared by the above two-step method, and a high-purity alkoxyindium tin compound solution after filtering the salt, Further, the filtrate is concentrated to remove the first solvent to obtain an alkoxyindium tin compound; and the second solvent and the chelating agent are added in a specific ratio to obtain an alkoxyindium tin compound coating liquid (third step). The chelating agent is convenient for long-term storage of the coating liquid, and the obtained indium tin oxide (ITO) film is relatively uniform and does not crack. The chelating agent is still preferably acetonitrile. The preferred concentration is acetonitrile to acetone 5 to 300 mole% of the alkoxyindium tin compound; the optimum concentration is 30 to 100 mole%.

The three-step method of the present invention prepares an alkoxyindium tin compound coating liquid, in addition to the above first solvent, which can be used as a second solvent, an alcohol reacted with an indium tin halide in a reaction system, or other C ₃ -C ₂₀ The alcohol can also be used as the second solvent. Preferred are cyclohexanol and C ₄ -C ₂₀ primary alcohols such as 1-butanol, 1-pentanol and the like. If the coating operation is to be sintered at 300 ° C, the alcohol can only be selected from C ₄ -C ₈ primary alcohols having a lower boiling point. In addition, the preferred amount of the second solvent is such that the concentration of the alkoxy tin indium compound is 5 wt% to 20 wt%; the optimum amount is such that the concentration of the alkoxy tin indium compound is 8 wt% to 15 wt%. operation.

The composition of the alkoxyindium tin compound coating liquid of the present invention is prepared by a two-step method and a three-step method, and is composed of an alkoxyindium tin compound, a solvent (including a first solvent and a second solvent), and a chelating agent. If the composition contains a small amount of unremoved impurities, it still falls within the technical scope of the present invention. The preferred concentration of the indium azide tin compound in the composition is 5 wt% to 20 wt%, and the optimum concentration is 8 wt% to 15 wt%. The alkoxyindium tin compound preferably has a composition of Sn(OR) ₄ /(In(OR) ₃ +Sn(OR) ₄ ) of 5 to 15 mole%, preferably 8 to 13 mole%. The chelating agent in the composition is β-diketone or its ester, etc., but acetonitrile is still preferred, and the preferred concentration is acetonitrile acetone 5~300 mole% than the alkoxyindium tin compound; the optimal concentration is 30~100 mole %. The composition is a solvent other than the alkoxyindium tin compound and the chelating agent. The solvent in the composition contains the first solvent or the second solvent, and they may be used singly or in combination with each other.

All of the above are related to THF solvent, expressed in wt%, and the rest are expressed in mole%.

The application of the indium azide tin compound coating liquid on the substrate to form indium tin oxide (ITO) in the present invention means adding the alkoxyindium tin compound coating liquid to an appropriate amount of water and coating at room temperature. On a glass or plastic substrate (about 1 μm in thickness), then hydrolyzed and condensed at 50-200 ° C (for sol-gel method) and removed the alcohols produced, and the residual solvents and chelate mixture. Or coating the alkoxyindium tin compound coating solution on a glass or plastic substrate (about 1 μm in thickness) at room temperature, and then performing hydrolysis and condensation reaction in a vapor chamber at 50 to 200 ° C to form indium tin An oxide (ITO) film that releases volatile alcohols. Then, the produced alcohols and the remaining solvents and chelating agents are removed at 50 to 200 °C. If necessary, it can be sintered to a conductive indium tin oxide (ITO) at above 200 °C. However, the optimum temperature conditions for sintering are not within the scope of this patent.

The alkoxy metal compound needs to be hydrolyzed under the condition of containing H ₂ O; on the other hand, the water molecule is removed during the condensation reaction, so H ₂ O/metal in the sol-gel process The alkoxide molar ratio (r) should not be too much or too little. When the ratio of low r is low, the decane oxygen compound is not easily hydrolyzed to make the reaction difficult to carry out. On the other hand, in a high water environment, the hydrolysis reaction can be completely but the condensation reaction is relatively suppressed, so Causes a change in the structure of the colloid. On the other hand, when the r value is less than 2, alcohol condensation is easily performed, and if the r value is more than 2, it is easily condensed with water. The application of the alkoxyindium tin compound coating liquid on the substrate to form indium tin oxide (ITO) in the present invention is carried out in an amount of water of 100 to 300 mole% than the alkoxyindium tin compound; It is 170~230mole% (r=1.7~2.3).

A two-step method for preparing an alkoxyindium tin compound coating solution:

The first step: firstly dissolving anhydrous grade indium halide (InX ₃ , anhydrous) and anhydrous grade tin halide (SnX ₄ , anhydrous) in alcohol and reaction medium (first solvent), drying at low temperature and passing nitrogen gas Then, each of them is stirred or mixed and stirred until clear and colorless, and an indium halide clear solution and a tin halide clear solution are respectively obtained. The above two solutions were then mixed and the reaction was continued for about half an hour to obtain a clear mixed solution.

The formula is formulated according to the following ratios: SnX ₄ /(InX ₃ +SnX ₄ ) is mixed at a ratio of 5 to 15 mole%; the amount of alcohol reacted with indium halide is (alcohol) / (anhydrous indium halide) is 300 mole%~ 580mole%, the total amount of reactive alcohols is (alcohol) / (anhydrous indium halide + anhydrous grade tin halide) is 310 mole% ~ 600 mole%, the first solvent is preferably used in total (first solvent) / (no water grade The indium halide + anhydrous grade tin halide + alcohol) is from 320 wt% to 1290 wt%.

The second step: pre-dissolving the chemical dose-based alkaline catalyst in the reaction medium (first solvent) or the same alcohol in the reaction system to dilute the concentration of the alkaline catalyst. This alkaline catalyst solution is then slowly added to the solution obtained in the first step, and reacted at a low temperature for a while until a large amount of salt precipitate is produced. At this time, an alkoxyindium tin compound solution and a precipitate were obtained. The precipitate was then filtered off to obtain an alkoxyindium tin compound solution. However, if the solvent is too much, a part of the solvent may be removed after the reaction is completed, so that the concentration of the alkoxy tin indium tin compound is preferably 5 wt% to 20 wt% for the operation. If necessary, add a suitable amount of chelating agent to the solution.

The amount of alkali added in the reaction is 310 to 500 mole% in terms of the following ratio (base catalyst) / (anhydrous indium halide ten anhydrous tin halide). The reaction medium (first solvent) to be used or the alcohol having the same reaction system is preferably used in an amount of from 10 to 50% by weight based on the base (alkali catalyst) / (alcohol or first solvent). The amount of the alcohol or first solvent used is within the total amount stated in the first step above. The ratio of the chelating agent to the alkoxyindium tin compound is 5 to 300 mole%.

A three-step method for preparing an alkoxyindium tin compound coating solution:

The method for producing an alkoxyindium tin compound coating liquid according to the three-step method of the present invention comprises a solution prepared by the above two-step method, and a high-purity alkoxyindium tin compound solution after filtering the salt, Further, the filtrate is concentrated to remove the first solvent to obtain an alkoxyindium tin compound; and a second solvent or an appropriate amount of a chelating agent is added in a specific ratio to obtain an alkoxyindium tin compound coating liquid (third step).

The amount of the second solvent and the chelating agent is added so that the concentration of the alkoxy tin indium compound is preferably from 5% by weight to 20% by weight. The preferred concentration of the chelating agent is 5 to 300 mole% of the chelating agent than the alkoxyindium tin compound; the optimum concentration is 30 to 100 mole%.

Application of coating an alkoxyindium tin compound coating solution on a substrate to form indium tin oxide (ITO):

The application of the indium azide tin compound coating liquid on the substrate to form indium tin oxide (ITO) in the present invention means adding the alkoxyindium tin compound coating liquid to an appropriate amount of water and coating at room temperature. On a glass or plastic substrate (about 1 μm in thickness), then hydrolyzed and condensed at 60-200 ° C (solugel method) and removed the alcohols produced, and the residual solvent and chelation mixture. Or coating the alkoxyindium tin compound coating solution on a glass or plastic substrate (about 1 μm in thickness) at room temperature, and then performing hydrolysis and condensation reaction in a steam chamber at 60 to 200 ° C to form indium tin An oxide (ITO) film that releases volatile alcohols. Then, the produced alcohols and the remaining solvents and chelating agents are removed at 60 to 200 °C. When necessary, it can be sintered to a conductive indium tin oxide (ITO) above 200 °C. However, the optimum temperature conditions for sintering are not within the scope of this patent.

The application of the alkoxyindium tin compound coating liquid on the substrate to form indium tin oxide (ITO) in the present invention is carried out in an amount of water of 100 to 300 mole% than the alkoxyindium tin compound; It is 170~230mole% (r=1.7~2.3).

The entire reaction production process of the above alkoxyindium tin compound coating liquid is shown in (a).

Other features and advantages of the present invention will be apparent from the following detailed description of the invention.

Embodiment 1: (three-step method)

Solution A (solution A) and solution B (solution B) were first prepared. Solvent A was prepared by dissolving anhydrous grade InCl ₃ (0.885 g, 0.004 mole) in a mixed solvent of 1-butanol (1.18 g, 0.016 mole) and 20 ml (17.76 g) in THF at room temperature. Further, anhydrous grade SnCl ₄ (0.16 g, 0.00044 mole) was dissolved in 1-butanol (0.13 g, 0.0017 mole) solvent and uniformly stirred at room temperature to obtain Solution B. Both Solution A and Solution B are colorless. The doping amount (Sn / (Sn + In) = SnCl ₄ / (InCl ₃ + SnCl ₄ )) of the fixed tin in this example was 10 mole% (= 10 atomic %). Solution B was added dropwise to Solution A in a drop-in manner, and it was transparent and colorless after stirring at room temperature. Thereafter, the temperature of the reaction system was set to 5 ° C and reacted for 0.5 hour (first step). The diluted triethylamine solution (containing 0.5 ml (0.405 g, 0.00547 mole) of 1-butanol, 4.5 ml (4 g) of THF and 1.4 g (0.0139 mole) of triethylamine was added dropwise by dropwise addition. (triethylamine)) was slowly dropped into the reaction system, and reacted at a temperature of 5 ° C for 1 hr to obtain a solution of the alkoxyindium tin compound containing the precipitate. The solution of the alkoxyindium tin compound containing the precipitate is placed in a freezer and left to stand overnight, and then the precipitate is filtered by centrifugal filtration to obtain a transparent colorless alkoxyindium tin compound solution for coating (second step) ). After extracting the solvent of the alkoxyindium tin compound solution by a rotary vacuum concentrator, about 1.5 g (0.004 mole) of the powdered butane indium tin oxide compound was obtained, followed by the addition of 13.15 g (16.23 ml) of 1-butanol and 0.4 g ( 0.004 mole) of acetylacetone (chelating agent) is formulated into a coating solution of alkoxyindium tin compound having a solid content of 10 wt.% (third step).

The obtained powdery alkoxyindium tin compound was identified by H-NMR and proved to be a high-purity butane-oxyn-indium tin compound (In(OBu) ₃ +Sn(OBu) ₄ ) as shown in the figure (II). The substance exists. The H-NMR spectrum of the butane-oxygen indium compound and the butane-oxygen compound is the same.

Before the wet coating, 0.144 g of H ₂ O was added to the above alkoxyindium tin compound coating liquid, and uniformly stirred. In this embodiment, the water-added alkoxyindium tin compound coating liquid was applied onto the surface of the glass substrate, the PET and the PI film by spin coating (rotation at 1000 rpm for 30 sec), and then the sample was heat-treated at 60 ° C for 30 minutes. Further, vacuum was applied at 150 ° C for 1 hour to remove the residual solvent.

1. First, a sample of the above ITO-glass substrate, the ITO film is analyzed by an EDS (Energy Dispersive Spectrometer), which is an ITO (Indium-Tin oxide), which does not contain chlorine (ie, InCl _{3 )} The reaction with SnCl ₄ is complete and free of impurities such as the HCl.NR ₃ salt or the indium chloride/alkylamine complex produced. However, it contains a very small amount of organic matter (C/(In+Sn) = 1 at%). Sn/(Sn+In) = 10.8% in the ITO film.

Annealing conditions If annealed at 300 ° C for 4 hr, the ITO film is analyzed by EDS, containing only In, Sn and O elements, which is ITO (Indium-Tin oxide), does not contain chlorine and organic carbon. Sn/(Sn+In) = 11% in the ITO film. The sample of the ITO-glass substrate can obtain a surface resistivity of about 4×10 ⁶ Ω/□ and a transmittance of 95% in the visible light range; if the annealing condition is annealed at 500 ° C for 1 hr, no chlorine or carbon is obtained. The pure ITO film of the material has a lower surface resistivity of about 2×10 ⁴ Ω/□ and a transmittance of 91% in the visible range; if the annealing condition is annealed at 800 ° C for 1 hr, a lower surface resistivity is obtained. It is 2 × 10 ^-3 Ω / □, and the transmittance is 88%.

2. The sample of the above ITO-PET substrate, if the annealing condition is annealed under vacuum at 200 ° C for 12 hr, a surface resistivity of about 4 × 10 ⁷ Ω / □ is obtained, which is an antistatic material. And the transmittance in the visible range is 95%. (PET substrate only has to withstand 200 ° C)

3. For the sample of the above ITO-PI substrate, if the annealing condition is performed at 300 ° C for 12 hr, the surface resistivity is about 4 × 10 ⁶ Ω / □, and the transmittance in the visible light range is 95%. (PET substrate only has to withstand 300 ° C to 400 ° C)

In the first embodiment:

The ratio of various substances in the first step:

SnCl ₄ /(InCl ₃ +SnCl ₄ )=10mole%

1-butanol (alcohol) / (InCl ₃ + SnCl ₄ ) = 399 mole%

THF (first solvent) / (InCl ₃ + SnCl ₄ + 1-butanol) = 754 wt%

The ratio of various substances in the second step:

Basic catalyst triethylamine (TEA) / (InCl ₃ + SnCl ₄ ) = 312 mole%

Basic catalyst triethylamine (TEA) / THF = 35wt%

Basic catalyst triethylamine (TEA) / (THF + alcohol) = 32wt%

THF / (InCl ₃ + SnCl ₄ + 1-butanol) = 786 wt% (first step + second step)

1-butanol (alcohol) / (InCl ₃ + SnCl ₄ ) = 522 mole% (first step + second step)

The third step:

Solid content: refers to butane indium tin oxide compound is 1.5g / (1.5g + second solvent + chelating agent) = 10wt% chelating agent / (In (OBu) ₃ + Sn (OBu) ₄ ) = 100 mole% or more The THF solvent is expressed in wt%.

Embodiment 2: (three-step method)

The formulation of this example was the same as in Example 1, except that the THF of the first solvent was changed to DMF. Which ITO film by EDS analysis, it still contains chlorine species (meaning InCl ₃ and SnCl ₄ reaction may be incomplete, or salts or HCl.NR ₃ arising indium chloride / alkylamine assembly error can not be completely made of DMF Precipitate). Cl / (In + Sn) = 1.5 at% and carbon-containing organic matter (C / (In + Sn) = 5.2 at%). Sn/(Sn+In) = 10.6% in the ITO film. This means that the effect of DMF is not as good as THF.

Embodiment 3: (two-step method)

In this embodiment, the two-step method is adopted, and the formulation is the same as that in the first embodiment. Only the amount of the solvent THF in the first step of the first embodiment is changed from 20 ml (17.76 g) to 11 ml (8.8 g), and after the completion of the second step. Then, after adding 0.4 g (0.004 mole) of acetylacetone (chelating agent), it is directly used as an alkoxyindium tin compound coating liquid.

In the third embodiment:

The ratio of various substances in the first step:

THF (first solvent) / (InCl ₃ + SnCl ₄ + 1-butanol) = 565 wt%

The ratio of various substances in the second step:

THF / (InCl ₃ + SnCl ₄ + 1-butanol) = 627 wt% (first step + second step)

Solid fraction (refers to butane indium tin oxide compound): 10wt%

The remaining ratios are the same as in the first embodiment.

Before the wet coating, 0.144 g of H ₂ O was added to the above alkoxyindium tin compound coating liquid, and uniformly stirred. The application of this embodiment is the same as that of the first embodiment.

The ITO film was analyzed by EDS and the purity was the same as in Example 1. A substance that does not contain chlorine, but contains a very small amount of organic matter (C/(In+Sn) = 1.1 at%). Sn/(Sn+In) = 10.5% in the ITO film. The surface resistivity varies depending on the temperature treatment conditions, and the results are similar to those in the first embodiment.

Embodiment 4: (two-step method)

This embodiment adopts a two-step method, and the formulation is the same as that of the third embodiment. However, no chelating agent was added and no H ₂ O was added prior to the wet coating.

The sample was heat-treated at 60 ° C for 30 min, and then vacuumed at 150 ° C for 1 hour. The ITO film was analyzed by EDS and contained no chlorine, but contained a large amount of organic matter (C/(In+Sn)=8.2 At%). Sn/(Sn+In) = 11.5% in the ITO film. When the coating liquid was not added with water, even when the chelating agent was not used, the ITO could not be completely formed at 150 ° C for 1 hour, and organic substances were left, which affected the electrical conductivity.

Embodiment 5: (two-step method)

The sample obtained by heat treatment of Example 4 was further heated at 300 ° C for 4 hours. The ITO film was analyzed by EDS, and as a result, it contained no chlorine and no chlorine and organic carbon. It means that the residual organic matter continues to be decomposed when heated at 300 ° C for 4 hours. This will increase its electrical conductivity.

Embodiment 6: (Two-step method of prior art)

This embodiment adopts the sequence of the two-step method of the prior art (U.S. Patent No. 4,681,959), and the formulation is the same as that of the third embodiment, except that in the second step of the third embodiment, the diluted alkaline catalyst solution is slow. The reaction is slowly added to the solution obtained in the first step for a certain period of time; however, in this embodiment, the solution obtained in the first step is directly added to the undiluted pure alkaline catalyst for a certain period of time (inverted order). Meanwhile, the two-step method disclosed in the two-step method of the prior art (U.S. Patent No. 4,681,959) is to synthesize organic solvent-insoluble metal alkoxides, and in this embodiment, an appropriate solvent is selected to be an organic solvent. A soluble alkoxy metal compound.

0.4 g (0.004 mole) of acetylacetone (chelating agent) was also added to the coating liquid of this example, but no H ₂ O was added before the wet coating.

The sample was heat-treated at 60 ° C for 30 min, and then vacuumed at 150 ° C for 1 hour. The ITO film was analyzed by EDS and still contained chlorine (meaning that InCl ₃ and SnCl ₄ may not be completely reacted, or HCl.NR ₃ Salts or the resulting indium chloride/alkylamine complexes cannot be completely precipitated from DMF). Cl / (In + Sn) = 2.5 at% and carbon-containing organic matter (C / (In + Sn) = 8.8 at%). Sn/(Sn+In) = 11.6% in the ITO film. This indicates that the high-purity alkoxyindium tin compound (In(OBu) ₃ +Sn(OBu) ₄ ) could not be obtained by the two-step method of the prior art.

The above is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Therefore, any person skilled in the art can use it without departing from the technical features of the present invention. The embodiments of the present invention have been made to modify or modify the equivalent embodiments without departing from the technical features of the present invention.

The first figure is a flow chart for the entire reaction production of the alkoxyindium tin compound coating liquid of the present invention.

FIG lines obtained from a second embodiment of the present invention is indium tin oxide butane 1- H ¹ -NMR spectrum of Compound (1-oxo-butane indium compound and tin compound 1- butylene oxide of the same H ¹ -NMR spectrum) .

Claims (45)

A method for producing an alkoxyindium tin compound coating liquid, comprising: dissolving anhydrous grade indium halide (InX ₃ ), anhydrous-grade tin halide (SnX ₄ ) and an alcohol in a specific ratio in a first solvent, at a low temperature The reaction is carried out for a period of time to form a clear solution; the diluted alkali catalyst is slowly added, and the reaction is carried out under a low temperature condition for a while, and after the salt precipitate is filtered off, the alkoxyindium tin compound is coated. liquid. The method for producing an alkoxyindium tin compound coating solution according to the first aspect of the patent application, wherein the diluted alkali catalyst is added to the reaction under a low temperature condition for a period of time and the salt precipitate is filtered off, and the solvent is concentrated and removed. The solvent comprises a first solvent and an unreacted alcohol, and the second solvent is added in a specific ratio to obtain the alkoxyindium tin compound coating liquid. The method for producing an alkoxyindium tin compound coating liquid according to claim 1 or 2, wherein the anhydrous-grade indium halide is selected from the group consisting of the following compounds: anhydrous chlorination Indium (InCl ₃ , anhydrous) and anhydrous grade indium bromide (InBr ₃ , anhydrous), the anhydrous grade tin halide is selected from the group consisting of the following compounds: anhydrous grade tin chloride (SnCl ₄ , Anhydrous) with anhydrous grade tin bromide (SnBr ₄ , anhydrous). The method for producing an alkoxyindium tin compound coating liquid according to claim 1 or 2, wherein the alcohol is selected from the group consisting of the following compounds: carbon tri-carbon 20 (C3) ~C20) a tertiary alcohol, cyclohexanol and mixtures thereof. The method for producing an alkoxyindium tin compound coating liquid according to the fourth aspect of the invention, wherein the alcohol is selected from the group consisting of the following compounds: carbon four to carbon eight (C4 to C8) a primary alcohol, 1-butanol, 1-pentanol, cyclohexanol, and mixtures thereof. The method for producing a coating solution of an alkoxyindium tin compound according to claim 1 or 2, wherein the first solvent is selected from the group consisting of chloroform. , dimethylformamide (DMF), acetonitrile, tetrahydrofuran (THF), dimethylhydrazine (DMSO), acetone, 1,4 dioxane (1,4dioxane), ethyl acetate And mixtures thereof. The method for producing an alkoxyindium tin compound coating liquid according to claim 6, wherein the first solvent is tetrahydrofuran. The method for producing a coating solution of an alkoxyindium tin compound according to claim 1 or 2, wherein the alkali-based catalyst is high in pKa value, low in nucleophilicity, and strong in hindered nitrogen. a base selected from the group consisting of trimethylamine (TMA), triethylamine (TEA), 1,1,3,3-tetramethylguanidine ( 1,1,3,3-tetramethylguanidine,TMG), 1,8-diazabicyclo[5,4,0]undecene hexene (diazabicyclo[5,4,0]undec-7-ene,DABU , 1,5-diazabicyclo[4,3,0]nonane (1,5-diazabicyclo[4,3,0]non-5-ene,DABN) and 1,8-bisdimethyl 1,8-bis(dimethylamino)naphthalene (Proton sponge). The method for producing an alkoxyindium tin compound coating liquid according to claim 8, wherein the alkali-based catalyst is triethylamine. The method for producing an alkoxyindium tin compound coating liquid according to claim 2, wherein the second solvent is selected from the group consisting of the following compounds: carbon tri-carbon twenty Alcohols of (C3~C20) and alcohols reacted with indium halides, chloroform, dimethylformamide (DMF), acetonitrile, tetrahydrofuran (THF), dimethylhydrazine (DMSO), acetone 1,4 dioxane (1,4 dioxane), ethyl acetate and mixtures thereof. The method for producing an alkoxyindium tin compound coating liquid according to the first aspect of the invention, wherein after the salt precipitate is filtered, a chelating agent is further added to obtain the alkoxyindium tin compound coating liquid. The chelating agent is selected from the group consisting of the following compounds: β-diketones and esters thereof. The method for producing an alkoxyindium tin compound coating liquid according to the second aspect of the invention, wherein after the second solvent is added in a specific ratio, a chelating agent is further added to obtain the alkoxyindium tin compound coating liquid. The chelating agent is selected from the group consisting of β-diketones and esters thereof. The method for producing a coating solution of an alkoxyindium tin compound according to claim 11 or 12, wherein the chelating agent is selected from the group consisting of the following compounds: methyl acetate ( Methyl acetoacetate), acetylacetone and mixtures thereof. The method for producing an alkoxyindium tin compound coating liquid according to claim 11 or 12, wherein the chelating agent is acetylacetone. The method for producing a coating solution of an alkoxyindium tin compound according to claim ₃ , wherein the anhydrous indium halide (InX ₃ ) and the anhydrous-grade tin halide (SnX ₄ ) are halogenated according to the anhydrous level. Tin is mixed in a ratio of 5 to 15 mole% of the total of the anhydrous grade indium halide and the anhydrous grade tin halide. The method for producing an alkoxyindium tin compound coating liquid according to claim 15, wherein the anhydrous-grade indium halide and the anhydrous-grade tin halide are based on the anhydrous-grade tin halide as the anhydrous-grade indium halide and The anhydrous-grade tin halide is mixed in a ratio of 8 to 13 mole%. The method for producing a coating solution of an alkoxyindium tin compound according to claim 4, wherein the alcohol is used in an amount of the anhydrous indium halide and the anhydrous tin halide. The total amount is 310mole%~600mole%. The method for producing a coating solution of an alkoxyindium tin compound according to claim 17, wherein the alcohol is used in an amount of the anhydrous indium halide and the anhydrous tin halide. The total combination is 380mole%~450mole%. The method for producing a coating solution of an alkoxyindium tin compound according to claim 6, wherein a total ratio of the specific ratio of the first solvent to the first solvent is the anhydrous indium halide The anhydrous grade tin halide and the alcohol are combined to be 320 wt% to 1290 wt%. The method for producing a coating solution of an alkoxyindium tin compound according to claim 19, wherein a total ratio of the specific ratio of the first solvent to the first solvent is the anhydrous indium halide, The anhydrous grade tin halide is 430 wt% to 810 wt% of the total of the alcohol. The method for producing a coating solution of an alkoxyindium tin compound according to claim 8, wherein the alkali catalyst is used in a ratio of anhydrous indium halide and the anhydrous grade. The sum of the tin halides is 310~500 mole%. The method for producing an alkoxyindium tin compound coating liquid according to claim 21, wherein the base catalyst is used in a ratio of the alkali-based catalyst to the anhydrous-grade indium halide and the anhydrous The sum of the two types of tin halides is 310~400 mole%. The method for producing a coating solution of an alkoxyindium tin compound according to claim 1 or 2, wherein the diluted base catalyst is used in an alcohol or 10 to 50% by weight of the first solvent, and the amount of the alcohol and the first solvent used is included in the total amount described in claim 17 or 19. The method for producing an alkoxyindium tin compound coating liquid according to claim 1 or 2, wherein the low temperature condition is -40 ° C to 60 ° C. The method for producing an alkoxyindium tin compound coating liquid according to claim 24, wherein the low temperature condition is 0 ° C to 10 ° C. The method for producing an alkoxyindium tin compound coating liquid according to the first aspect of the invention, wherein the anhydrous-grade indium halide, the anhydrous-grade tin halide and the alcohol are dissolved in the first solvent according to a specific ratio formula, and are at a low temperature. The reaction was carried out for 0.5 hour under conditions to form a clear solution; the diluted alkali catalyst was slowly added, and the reaction was carried out under low temperature conditions for more than 1 hour to obtain a large amount of salt precipitation. An alkoxyindium tin compound coating liquid produced by the production method according to any one of claims 1 to 26. An alkoxyindium tin compound coating liquid comprising: an alkoxyindium tin compound and a second solvent, wherein the indium tin oxide in the compound is dissolved in the solvent in a specific atomic ratio of indium and tin. The alkoxyindium tin compound coating liquid according to claim 28, which further comprises a chelating agent. The alkoxyindium tin compound coating liquid according to claim 29, wherein the chelating agent is selected from the group consisting of the following compounds: methyl acetoacetate, acetamidine Acetone (acetylacetone) and mixtures thereof. The alkoxyindium tin compound coating liquid according to any one of claims 28 to 30, wherein the alkoxyindium tin compound is a mixture of an alkoxyindium compound and an alkoxy tin compound. The alkoxyindium tin compound coating liquid according to claim 31, wherein the alkoxyindium tin compound is an alkoxyindium tin compound produced by a nonaqueous anhydrous indium halide, a nonaqueous anhydrous tin halide, and an alcohol. And the anhydrous grade indium halide is selected from the group consisting of: anhydrous grade indium chloride (InCl ₃ , anhydrous) and anhydrous grade indium bromide (InBr ₃ , anhydrous), the anhydrous grade tin halide system The group consisting of the following compounds is selected: anhydrous grade tin chloride (SnCl ₄ , anhydrous) and anhydrous grade tin bromide (SnBr ₄ , anhydrous), the alcohol being selected from the group consisting of the following compounds Group: carbon tri-carbon 20 (C3 ~ C20) one-stage alcohol, 1-butanol, 1-pentanol, cyclohexanol and mixtures thereof; the second solvent is selected from the group consisting of the following compounds Group: alcohols of carbon three to carbon twenty (C3 ~ C20) and alcohols reacted with tin halides, chloroform, dimethylformamide (DMF), acetonitrile, tetrahydrothiopyran (THF), dimethylhydrazine (DMSO), acetone, 1,4 dioxane (1,4 dioxane), ethyl acetate, and mixtures thereof. The alkoxyindium tin compound coating liquid according to claim 31, wherein the alkoxyindium tin compound is selected from the group consisting of the following compounds: 1-butane indium tin oxide compound, 1 a pentane indium tin compound, a cyclohexane indium tin compound, and a mixture thereof. The alkoxyindium tin compound coating liquid according to claim 31, wherein the number of tin atoms in the alkoxyindium tin compound is 5 at% to 15 at% of the total of the number of tin and indium atoms. The alkoxyindium tin compound coating liquid according to claim 34, wherein the number of tin atoms in the alkoxyindium tin compound is from 8 at% to 13 at% of the total of the number of tin and indium atoms. The alkoxyindium tin compound coating liquid according to claim 29, wherein the concentration of the chelating agent is 5 to 300 mole% of the concentration of the alkoxy tin indium compound. The alkoxyindium tin compound coating liquid according to claim 36, wherein the concentration of the chelating agent is 30 to 100 mole% of the concentration of the alkoxyindium tin compound. The alkoxyindium tin compound coating liquid according to claim 28 or 29, wherein the concentration of the alkoxyindium tin compound is 5 wt% to 20 wt% of the alkoxyindium tin compound coating liquid. The alkoxyindium tin compound coating liquid according to claim 38, wherein the concentration of the alkoxyindium tin compound is from 8 wt% to 15 wt% of the alkoxyindium tin compound coating liquid. The invention relates to a method for preparing an indium tin oxide film, comprising: providing a substrate, the substrate is glass or plastic; providing an alkoxyindium tin compound coating solution; and coating the alkoxyindium tin compound coating solution on the substrate The substrate is subjected to hydrolysis and condensation reaction at 50 to 200 ° C to remove the produced alcohol-based substance, and each of the remaining solvent and the chelating agent to obtain the indium tin oxide film. The method for producing an indium tin oxide film according to claim 40, wherein applying the alkoxyindium tin compound coating liquid to the substrate further comprises diluting the alkoxyindium tin compound coating liquid with water. The method for producing an indium tin oxide film according to claim 40, wherein after the hydrolysis and the condensation reaction, the sintering is further performed, and the sintering temperature is greater than 200 ° C, and the sintering time is greater than 30 minutes. The method for producing an indium tin oxide film according to claim 42, wherein the sintering is further performed after the hydrolysis and condensation reaction, and the sintering temperature is greater than 300 °C. The method for preparing an indium tin oxide film according to claim 41, wherein when the alkoxyindium tin compound coating solution is diluted with water, the amount of water added to the water is 100 to 300 moles than the alkoxyindium tin compound. %. For example, in the method for preparing an indium tin oxide film according to claim 44, when the alkoxyindium tin compound coating solution is diluted with water, the amount of water added to the water is 170 to 230 mole% more than the alkoxyindium tin compound.