JP2016069350A - Method for producing gold resinate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a gold resinate suitable for a gold resinate paste, which can form a gold film having sheet resistance by calcination at a low temperature of 250°C or less to improve drawbacks in conventional high temperature calcination of the gold resinate paste.SOLUTION: The method for producing a gold resinate comprises the steps of: preparing a mixture by adding aurous chloride, an alkali metal salt such as sodium chloride and potassium chloride, and mercaptoalcohols in pure water; adjusting the pH of the mixture to 7.0 to 13.5 while bubbling an inert gas such as argon gas and nitrogen gas into the mixture; and keeping the reaction system at 10°C to 90°C for several hours. This production method requires only preparing a mixture of aurous chloride, an alkali metal salt, and mercaptoalcohols and making the reaction proceed, and it becomes unnecessary to perform detailed adjustment of the rate of addition of the starting materials, the reaction rate, the reaction temperature, and the like.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a gold resinate. More specifically, the present invention relates to the production of a gold resinate for use in a conductive paste for forming a gold film conductive circuit on an electronic component such as a polyamide film, a printed wiring board, a ceramic IC package, or a wafer. Regarding the method.

Conventionally, a gold resinate paste is known as a conductive paste used for forming a conductive pattern such as a film electrode on a substrate.
A typical application of such a gold resinate paste is the production of electrodes for thermal printer heads used as printer heads for facsimiles and the like.

Prior art related to this application includes gold resinates such as α-pinene, α-terpineol, gold isocaptane, or sulfide gold, gold abethienate, gold neodecanoate, gold 2-ethylhexanoate, gold naphthenate. After using a gold resinate paste containing a rhodium compound, a bismuth compound, a chromium compound, a lead compound, a silicon compound, an organic resin, an organic solvent, and screen printing on a ceramic substrate, It is known that a gold thin film is obtained by baking at 800 to 850 ° C. (for example, Patent Document 1).
Since such a conventional gold resinate paste is fired at a high temperature of 800 ° C. or higher, only a material that can withstand high temperatures such as ceramics can be used as a substrate. It was impossible to apply to functional resin films such as polyamide films and substrates known as heat resistant films. Moreover, since the thing corresponding to high temperature is used as a baking furnace, there also existed a problem which requires energy cost.

JP-A-5-144318

  The present invention provides a method for producing a gold resinate suitable for a gold resinate paste capable of improving a difficulty in high-temperature firing of such a conventional gold resinate paste and forming a gold film having sheet resistance even by low-temperature firing at 250 ° C. or lower. The purpose is to provide.

  In order to solve the above problems, the present inventor has intensively studied a method for producing a gold resinate capable of obtaining a gold film having sheet resistance by baking at a low temperature. The gold resinate obtained by reacting the reaction solution in an aqueous solution containing a reducing agent in the presence of 0 ° C to 90 ° C and concentrating and crystallizing the reaction solution after completion of the reaction is used as a gold resinate paste and screen-printed on a polyamide film. As a result of baking at 250 ° C., it has been found that a gold film having excellent sheet resistance can be obtained, and a patent application has already been filed as Japanese Patent Application No. 2013-191354.

However, in the manufacturing method of the above patent, a reducing agent and a mercapto alcohol as a ligand are slowly added while checking the state of the reaction while bubbling an inert gas into a suspension solution of gold salt such as gold hydroxide. It was necessary to proceed the reaction. Therefore, it is very difficult to control the addition rate, and if the balance between the reaction rate and the addition rate and the temperature of the synthesis system is lost, the progress of the reaction stops, decomposition occurs, and by-products are generated. It was difficult to obtain the desired gold resinate. In other words, there is a problem in that synthesis is not possible without a person skilled in the synthesis.
As a result of further research to improve the above-mentioned problems, the present inventor has obtained pure water by adding pure metal chloride synthesized from chloroauric acid, alkali metal salts such as sodium chloride and potassium chloride, and mercaptoalcohols. The mixture is added to the mixture to adjust the pH to 7.0 to 13.5 while bubbling an inert gas such as argon gas or nitrogen gas, and the reaction system is kept at 10 to 90 ° C. for several hours. The inventors reached the present invention by discovering that a gold resinate can be obtained.

That is, this invention makes the following content the summary of the invention.
(1) It is characterized by reacting at a temperature of 10 ° C. to 90 ° C. in an aqueous solution adjusted to pH 7.0 to 13.5 in the presence of an inert gas with gold chloride, alkali metal chloride and mercapto alcohol. A method for producing a gold resinate represented by the following general formula (1) in which mercapto alcohols are coordinated to gold ions.
General formula (1)
(1)
(Wherein n is 2-6)

(2) The gold according to claim 1, wherein the mercapto alcohol is at least one selected from 2-mercaptoethanol, 3-hydroxypropyl mercaptan, 4-hydroxybutyl mercaptan, 5-hydroxypentyl mercaptan and 6-hydroxyhexyl mercaptan. Resinate production method.
(3) The method for producing a gold resinate according to claim 1 or 2, wherein the alkali metal chloride is sodium chloride or potassium chloride.

  According to the method for producing a gold resinate of the present invention, the intended reaction product can be obtained by proceeding the reaction by placing preliminary gold chloride, alkali metal chloride and mercapto alcohol as a mixed solution. Therefore, detailed adjustments such as the starting material addition rate, reaction rate, reaction temperature and the like are not required, and the manufacturing cost can be reduced and the standardization of operations can be facilitated.

Hereinafter, the manufacturing method of the gold resinate of this invention is demonstrated in detail.
As a method for producing the first gold chloride used in the present invention, gold is dissolved in aqua regia, concentrated by heating, and then denitrated by adding hydrochloric acid while heating. Thereafter, concentration is performed to obtain chloroauric acid. This is manufactured by heating to 100 ° C. under high vacuum conditions to completely remove moisture and then heating to 160 ° C. or higher for decomposition.

The pale yellow crystalline first gold chloride obtained by the above method is added to pure water and stirred. Thereto, an alkali metal salt such as sodium chloride or potassium chloride and mercapto alcohol are added and stirred to obtain a mixed solution.
Examples of the mercapto alcohols include 2-mercaptoethanol, 3-hydroxypropyl mercaptan, 4-hydroxybutyl mercaptan, 5-hydroxypentyl mercaptan, 6-hydroxyhexyl mercaptan and the like.
An alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is added to this mixed solution while bubbling an inert gas such as nitrogen gas or argon gas to adjust the pH to 7.0 to 13.5. Further, the reaction system is maintained at 10 ° C. to 90 ° C., preferably 75 ° C. to 90 ° C. for several hours, while continuing the bubbling and stirring of the inert gas to promote the reaction.
When crystals are precipitated, the reaction system is cooled to 30 ° C. or lower and filtered to obtain precipitated crystals. The obtained crystal is dried at 120 ° C. or lower to obtain a gold resinate crystal powder.

  The formation reaction of the gold resinate of the present invention is considered to proceed according to the following reaction formula.

As a result of component analysis of crystals obtained by synthesizing mercaptoalcohols with 2-mercaptoethanol by the above method, Au: 71.8% (calculated value: 71.9%), which almost agrees with the theoretical value, S: It was 11.6% (calculated value: 11.7%). Therefore, it confirmed that the gold resinate of this invention was a crystal | crystallization represented by the said General formula (1).
Hereinafter, the present invention will be described specifically by way of examples.

250.0 g of chloroauric acid tetrahydrate is heated to 100 ° C. under high vacuum conditions to completely remove moisture. Next, the reaction is promoted by promoting decomposition until crystallization while maintaining the temperature at 160 ° C. to 180 ° C. by indirect heating. After the completion of the reaction, the reaction mixture was cooled to obtain 117.4 g of light yellow crystalline first gold chloride.
1000 ml of pure water is added to 100.0 g of the obtained gold chloride and stirred. Thereto, 30.2 g of sodium chloride and 35.3 g of 2-mercaptoethanol are added, and nitrogen gas is bubbled. A sodium hydroxide solution is then added to adjust the pH to 11.5. At this time, bubbling of nitrogen gas and stirring are continued. The reaction system after pH adjustment is brought to 80 ° C., and nitrogen gas bubbling and stirring are continued for 8 hours to promote the reaction.
After completion of the reaction, the reaction system is cooled to 30 ° C. or lower. Next, the precipitated crystals were filtered, washed with pure water, further washed with ethanol, and dried at 80 ° C. to obtain 70.7 g of a pale yellow powdery crystal.
The analysis result of the obtained crystal was as follows.
Au: 71.8% (calculated value: 71.9%), S: 11.6% (calculated value: 11.7%)

200.0 g of chloroauric acid tetrahydrate is heated to 100 ° C. under high vacuum conditions to completely remove moisture. Next, the reaction is promoted by promoting decomposition until crystallization while maintaining the temperature at 160 ° C. to 180 ° C. by indirect heating. After the completion of the reaction, the reaction mixture was cooled to obtain 90.8 g of pale yellow crystalline first gold chloride.
800 ml of pure water is added to 80.0 g of the obtained gold chloride and stirred. Thereto, 30.8 g of potassium chloride and 28.2 g of 2-mercaptoethanol are added, and nitrogen gas is bubbled. A sodium hydroxide solution is then added to adjust the pH to 11.5. At this time, bubbling of nitrogen gas and stirring are continued. The reaction system after pH adjustment is brought to 80 ° C., and nitrogen gas bubbling and stirring are continued for 8 hours to promote the reaction.
After completion of the reaction, the reaction system is cooled to 30 ° C. or lower. Next, the precipitated crystals were filtered, washed with pure water, further washed with ethanol, and dried at 80 ° C. to obtain 54.6 g of pale yellow powdery crystals.
The analysis result of the obtained crystal was as follows.
Au: 71.7% (calculated value: 71.9%), S: 11.5% (calculated value: 11.7%)

Claims (3)

Gold ions characterized by reacting at a temperature of 10 ° C. to 90 ° C. in an aqueous solution prepared by adjusting ferrous chloride, alkali metal chlorides and mercapto alcohols to pH 7.0 to 13.5 in the presence of an inert gas. A method for producing a gold resinate represented by the following general formula (1) in which mercapto alcohols are coordinated with each other.
General formula (1)
(1)

(Wherein n is 2-6)   The production of gold resinate according to claim 1, wherein the mercapto alcohol is at least one selected from 2-mercaptoethanol, 3-hydroxypropyl mercaptan, 4-hydroxybutyl mercaptan, 5-hydroxypentyl mercaptan and 6-hydroxyhexyl mercaptan. Method. The method for producing a gold resinate according to claim 1 or 2, wherein the alkali metal chloride is sodium chloride or potassium chloride.