JPH0133108B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to indium diacetylacetonate monoisopropylate useful for forming transparent conductors and a method for producing the same.

BACKGROUND OF THE INVENTION In recent years, indium oxide films have come to be used as transparent conductive films for liquid crystal devices, and the range of applications has been expanding to take advantage of the properties of indium as a metal.

Methods for forming such an oxide film include a chemical spray method, a vacuum evaporation method, a screen printing method, and the like. Although the chemical spray method is advantageous in obtaining a film with a relatively large area, it is economically disadvantageous because extra steps such as etching are required to obtain a film with a fine and complex shape. The vacuum evaporation method has recently developed into a mask evaporation method and no longer requires etching, but since it is a batch method, it is not suitable for mass production. The screen printing method has the advantage that it does not have the above-mentioned problems, can easily obtain a desired shape by printing and firing, and does not require waste liquid treatment associated with etching.

However, conventional pastes for forming transparent conductive films containing indium compounds do not have good stability themselves, resulting in poor workability during screen printing, and the conductivity of the formed films also varies widely. There was a drawback.

That is, conventional indium compounds for forming transparent conductors include organic acid indium such as indium octylate [(C ₇ H ₁₅ CO ₂ ) ₃ ln],
Indium trisacetylacetonate [In
(acac) ₃ ] is used.

Indium organic acids are generally easy to hydrolyze;
In addition, when made into a paste, it has the disadvantage of being relatively easily chemically changed, such as promoting gelation of the paste.For this reason, the life of the paste containing indium organic acid is short, and the workability during screen printing is It is the cause of deterioration.

Problems to be Solved by the Invention The present invention eliminates the drawbacks of conventional indium compounds for forming transparent conductors, that is, provides an indium compound with excellent chemical stability and easy screen printing operation, and The present invention provides a method for manufacturing the same.

Means to solve the problem The above problem is solved by the following structural formula (1): This problem can be solved by indium diacetylacetonate monoisopropylate.

In addition, the above indium diacetylacetonate monoisopropylate has the following structural formula (2): Indium triisopropylate represented by
Structural formula (3) below: It is produced by the method of the present invention, which is characterized by reacting with acetylacetone represented by:

Effects and Examples Indium diacetylacetonate monoisopropylate according to the present invention has good chemical stability and good solubility in organic solvents. Therefore, indium diacetylacetonate monoisopropylate can be uniformly dissolved in an organic solvent such as benzene or ethyl acetate at a high concentration, and the resulting paste can be used for forming transparent conductors such as films. can be used.

In the method of the present invention, 1 mole part of indium triisopropylate is reacted with 2 moles of acetylacetone to obtain 1 mole part of indium diacetylacetonate monoisopropylate.
In this reaction, a desired amount of indium triisopropylate may be dissolved in an organic solvent, and a predetermined amount of acetylacetone may be added dropwise to this solution.
Alternatively, predetermined amounts of indium triisopropylate and acetylacetone may be dissolved separately in an organic solvent, and these two solutions may be mixed.

In any of the above reaction operations, the reaction system is maintained at a predetermined temperature and stirred until the reaction is completed. Once the reaction is complete, the organic solvent and the produced isopropyl alcohol are removed from the reaction system under normal pressure.
Alternatively, the target compound is obtained by distilling and removing under reduced pressure.

In the above reaction, the reaction temperature is not particularly limited, but generally a temperature of room temperature or higher and 100°C or lower is preferred. Even if the reaction temperature is made higher than 100°C, there is no particular effect and it becomes economically disadvantageous. Within the above reaction temperature range, the reaction time is from several minutes to several hours.

The solvent used in the reaction of the method of the present invention is indium triisopropylate, acetylacetone,
and indium diacetylacetonate monoisopropylate,
However, as long as it has excellent solubility, there are no particular limitations, but it is generally preferred to use at least one selected from benzene, toluene, xylene, and the like.

As mentioned above, after the reaction is completed, the organic solvent and isopropyl alcohol are distilled off from the reaction system under normal pressure or reduced pressure. The boiling point of the solvent used is
When the temperature is higher than the decomposition point of indium diacetylacetonate monoisopropylate, the distillation removal operation is preferably carried out under reduced pressure at a temperature lower than the decomposition point of the target compound.

Since the indium diacetylacetonate monoisopropylate of the present invention is easily dissolved in an organic solvent and a highly concentrated paste can be easily obtained, this paste is particularly suitable for forming a transparent conductive film of a liquid crystal element.

To obtain such a paste for forming a transparent conductive film, indium diacetylacetonate monoisopropylate of the present invention is dissolved in an organic solvent such as benzene, ethyl acetate, or methyl ethyl ketone at a concentration of 2 to 20% by weight. Bye. At this time, if an organic complex compound of tin, such as dibutyltin acetate, is added to the paste as a resistance value adjusting agent so that the atomic ratio of tin to indium is 5 to 30%, transparent conductivity with a lower resistance value can be achieved. A coating, for example an electrode, is obtained.

Example 1 A 500 ml four-necked flask was equipped with a stirrer, a thermometer, a dropping funnel, and a cooling tube with a drying tube.
35.05 g (120 mmol) of indium triisopropylate and 300 ml of benzene in this flask.
was added, and while stirring at room temperature, 24.03 g (240 mmol) of acetylacetone was added dropwise from the dropping funnel over 5 minutes. After the dropwise addition was completed, the reaction mixture was heated to 80°C and refluxed for 30 minutes, then the insoluble matter was filtered off, the benzene and the produced isopropyl alcohol were distilled off, and the filtrate was concentrated under reduced pressure to form a residue. 42.8 g (yield 95.9%) of indium diacetylacetonate monoisopropylate was obtained. of this
The NMR measurement results were as follows. ¹ H NMR (CDCl ₃ ) δ (ppm) 1.09 (d, 6H) 1.93 (s, 12H) 4.12 (m, 1H) 5.28 (s, 2H) In addition, the indium content of this product was measured by chelate titration. 31.0% (theoretical value 30.85
%), and its infrared characteristic absorption is chelate C=O structure: 1582 cm ^-1 and chelate C=
C structure: It was 1526 cm ^-1 .

Example 2 The same operation as in Example 1 was performed. However, indium triisopropylate and acetylacetone were each dissolved separately in 150 ml of benzene, and both solutions were mixed and reacted in a flask.

The yield of the product obtained was 94.5%, and the product showed the same NMR measurement results and indium content as described in Example 1.

Effects of the Invention The indium diacetylacetonate monoisopropylate of the present invention exhibits good stability and solubility in organic solvents, and is therefore useful for forming transparent conductive films. Furthermore, by the method of the present invention, indium diacetylacetonate monoisopropylate can be obtained in good yield.

Claims (1)

[Claims] 1. Structural formula (1) below: Indium diacetylacetonate monoisopropylate. 2 Structural formula (2) below: Indium triisopropylate represented by
Structural formula (3) below: The following structural formula (1) is characterized by reacting with acetylacetone represented by: A method for producing indium diacetylacetonate monoisopropylate represented by 3. The method of claim 2, wherein the reaction of indium triisopropylate and acetylacetone is carried out at a temperature from room temperature to 100°C.