Method for producing silver carboxylate

Abstract

Provided is a method for producing high-quality silver carboxylate, the method comprising the steps of: (a) neutralizing a carboxylic acid and a base in a water-containing solvent to form an aqueous solution of a carboxylate salt; (b) allowing the carboxylate salt to react with a silver compound to obtain a silver carboxylate product; (c) providing a solution of the silver carboxylate product dissolved in a soluble organic solvent; and (d) precipitating the dissolved silver carboxylate product in a non-solvent to obtain silver carboxylate with impurities removed.

Description

Method for producing silver carboxylic acid

[0001] The present invention relates to a method for producing high quality silver carboxylic acid.

[0002] Metal carboxylates are a type of metal salt in which a metal is bonded to an organic acid, carboxylic acid. These carboxylic acid metal salts, such as those of alkali metals such as lithium and potassium, alkaline earth metals such as magnesium and calcium, and transition metals such as cobalt, manganese, nickel, lead, zinc, zirconium, aluminum, tin, and iron, are used in industry as metal precursors, as desiccants in the paint industry, or as catalysts and lubricants for organic synthesis and the production of polymer resins. In addition, carboxylic acid metal salts of copper, silver, gold, palladium, platinum, rhodium, ruthenium, iridium, neodymium, bismuth, indium, antimony, chromium, and titanium have long been used as plating or coating paste additives in the production of high-end decorative materials such as glass and ceramics. Among the various metals mentioned above, silver metal in particular has excellent electrical, thermal, optical and friction properties, as well as excellent antibacterial and reflective properties, and is used in a wide range of fields, including various electronic products such as cell phones, solar cells, automobiles, semiconductors, and daily necessities such as mirrors.

[0003] Specifically, silver carboxylate as a silver precursor is directly used as a raw material for printed electronics inks, conductive pastes, and plating solutions, and is utilized as an additive in the manufacture of electrodes, electromagnetic shielding, and heat dissipation products. It is also applied as a catalyst for various electrochemical reactions, medical and antibacterial products, water treatment, and the manufacture of silver mirrors (Korean Patent No. 10-2476608, International Patent No. WO2023 / 090964A1, U.S. Patent No. 9,683,123, U.S. Patent No. 9,873,662, and U.S. Patent No. 10,160,869).

[0004] As an example of a method for manufacturing such silver carboxylate, the method using silver nitrate as a silver precursor is the most common and well-known method, as can be seen in many patents and various literature. Manufacturing using silver oxide is also disclosed in U.S. Patent No. 3,385,654, U.S. Patent No. 4,723,024, and U.S. Patent No. 9,198,288, etc. However, with the above-mentioned common methods, silver carboxylates having 6 or more carbon atoms, especially silver neodecanoate having 10 carbon atoms, are widely used due to their excellent solubility, economic feasibility, and wide applicability in various fields, but it is difficult to find a white, high-purity mass-produced product on the market. For example, in manufacturing this, when the above silver nitrate or silver oxide is reacted with neodecanoic acid to manufacture silver neodecanoic acid, there have been difficulties in mass-producing high-quality silver neodecanoic acid commercially, as reaction impurities are contained in the product or the product color is light brown.

[0005] Accordingly, the present invention has been achieved as a result of continuous efforts to solve the above-mentioned problems in producing high-quality silver carboxylic acid having a white color and high purity.

[0006] The purpose of the present invention is to provide a method for producing high-quality silver carboxylic acid in large quantities.

[0007] According to one aspect of the present invention, a method for producing high-quality silver carboxylate is provided, comprising the steps of: (a) neutralizing a carboxylic acid and a base in a water-containing solvent to form an aqueous solution of a carboxylic acid salt; (b) reacting the carboxylic acid salt with a silver compound to obtain a silver carboxylate product; (c) providing a solution of the silver carboxylate product dissolved in an soluble organic solvent; and (d) precipitating the dissolved silver carboxylate product in a non-solvent to obtain silver carboxylate from which impurities have been removed.

[0008] In one embodiment, the water-containing solvent may be water alone, a mixed solvent of water and a polar solvent, or a mixed solvent of water and a soluble organic solvent.

[0009] In one embodiment, the carboxylic acid may have 6 or more carbon atoms.

[0010] In one embodiment, the carboxylic acid to base may have a molar ratio of 1:2 to 2:1.

[0011] In one embodiment, the pH of the aqueous solution may be adjusted to 6.0 to 8.0.

[0012] In one embodiment, the carboxylic acid salt to the silver compound may have a molar ratio of 1:2 to 2:1.

[0013] In one embodiment, the solution of step (c) may be provided in a form in which the carboxylic acid silver product precipitated in the water-containing solvent of step (b) is dissolved in a separate soluble organic solvent.

[0014] In one embodiment, the step (b) may further include a step of washing the carboxylic acid product with water and alcohol.

[0015] In one embodiment, the solution of step (c) may be a mixed solvent in which the water-containing solvent of step (a) further includes the soluble organic solvent, and after the reaction, the carboxylic acid product is provided in a form dissolved in the soluble organic solvent.

[0016] In one embodiment, the available organic solvent may be an aromatic hydrocarbon. Preferably, the aromatic hydrocarbon may be at least one selected from the group consisting of toluene, xylene, and mesitylene.

[0017] In one embodiment, the nonsolvent may be at least one selected from the group consisting of methanol, ethanol, propanol, isopropanol, butanol, acetone, and acetonitrile. Preferably, the nonsolvent may be methanol.

[0018] In one embodiment, the amount of the non-solvent may be 100 to 900% of the weight of the carboxylic acid product dissolved in the available organic solvent.

[0019] In one embodiment, the dissolution and precipitation processes of steps (c) and (d) may be repeated two or more times.

[0020] In one embodiment, the silver carboxylic acid may be represented by the following general formula 1.

[0021] [General Formula 1]

[0022] R1R2R3C-COOAg

[0023] In the above [general formula 1], substituted or unsubstituted C4-C of R1+R2+R3≥C4 20 Alkyl group, substituted or unsubstituted C4-C 28 Cycloalkyl group, substituted or unsubstituted C4-C 28 Aralkyl, substituted or unsubstituted C4-C 28 Heteroalkyl group, substituted or unsubstituted C4-C 28 Heterocycloalkyl group, or substituted or unsubstituted C4-C 28 It is a heteroaralkyl group.

[0024] According to another aspect of the present invention, a silver carboxylic acid having a purity of 99% or more is provided, manufactured by the above-described method.

[0025] According to the present invention, high-quality silver carboxylic acid having a purity of 99% or more can be mass-produced.

[0026] Figure 1 is a process flow diagram showing one embodiment of a method for manufacturing high-quality silver carboxylic acid.

[0027] Figure 2 is a schematic diagram showing two processes for producing high-quality silver carboxylic acid.

[0028] Figure 3 is a photograph of a neodecanoic acid silver powder product manufactured in Example 1.

[0029] Figure 4 is a thermogravimetric analysis (TGA) graph of neodecanoic acid manufactured in Example 1.

[0030] Figure 5 is a differential scanning calorimetry (DSC) graph of neodecanoic acid manufactured in Example 1.

[0031] Figure 6 is a hydrogen nuclear magnetic resonance spectrum of neodecanoic acid silver and neodecanoic acid prepared in Example 1. 1 This is the H-NMR Spectrum in Toluene-D8) data.

[0032] Figure 7 is a photograph of a neodecanoic acid silver powder product manufactured in Comparative Example 1.

[0033] Figure 8 is a differential scanning calorimetry (DSC) graph of neodecanoic acid manufactured in Comparative Example 1.

[0034] Figure 9 is a photograph of a neodecanoic acid silver powder product manufactured in Comparative Example 2.

[0035] Figure 10 is a differential scanning calorimetry (DSC) graph of neodecanoic acid manufactured in Comparative Example 2.

[0036]

[0037] Generally, the raw materials used in the manufacture of silver carboxylate are mainly carboxylic acid, which is an organic acid, and silver nitrate as a silver precursor, and a base such as sodium hydroxide, potassium hydroxide, or ammonia water in an aqueous solution. However, when using an organic acid with 6 or more carbon atoms, the manufactured silver carboxylate may contain impurities depending on the manufacturing conditions (Chem. Mater., 16, 2021~2027 (2004), Macromol. Rapid Commun., 26, 315~318 (2005), Chem. Mater., 21, 343~350 (2009)) or a sticky solid may be precipitated (J. Ceramic Processing Research, 8(3), 219~223 (2007)). Therefore, to purify it, it is thoroughly washed with deionized water (hereinafter referred to as water) and alcohol and vacuum-dried. However, due to the water-holding capacity that long-chain metal salts generally have (a general characteristic of carboxylic acid metal salts with 6 or more carbon atoms), it still contains a certain amount of water even after vacuum-drying. In addition, unreacted substances dissolved in water and impurities after reaction cannot escape and remain together. For this reason, mass production of high-purity, high-quality silver carboxylate has been problematic. In other words, the general purification method of washing with a solvent and drying after manufacturing has limitations. For example, when water is used as the main solvent, the reaction yield after drying often exceeds 100% depending on the manufacturing conditions. This is because a certain amount of water and reaction impurities remain in the product even after general vacuum drying. As such, it is difficult to control the moisture content and impurities for each manufacturing batch, making it difficult to guarantee uniform product production and high quality.In other words, when manufacturing particle-free inkjet inks or paste inks for electrodes in recent printed electronics or solar power fields, using these non-uniform raw materials can lead to poor quality uniformity and a major cause of product performance degradation, leading to various problems. The purity of commercially available silver neodecanoate typically ranges from 95 to 97%.

[0038] Meanwhile, to avoid these problems, methods for manufacturing without using a base in an aqueous solution, as described above, have also been proposed. That is, a method in which a silver compound is converted from silver nitrate to silver oxide and reacted using only carboxylic acid and silver oxide without a solvent (U.S. Patent No. 3,385,654) and a method in which an organic solvent of the aromatic hydrocarbon series, such as toluene, xylene, cumene, or mesitylene, is used (U.S. Patent Nos. 4,723,024 and 9,198,288) can be mentioned. However, in the case of manufacturing in this way, the product has a color such as light brown, and there is a limit to obtaining a high-quality white product.

[0039] The inventor has made continuous efforts to overcome these problems and has thus arrived at the present invention.

[0040] To manufacture high-quality products, the initial reaction product, silver carboxylate, such as silver neodecanoate, which is not of sufficient purity due to impurities, must be highly purified. That is, even if the initial reaction product obtained through the reaction in an aqueous solution is thoroughly washed with water and alcohol and vacuum-dried, silver neodecanoate will always contain impurities along with water due to its drying properties. These impurities include unreacted raw materials such as neodecanoic acid and inorganic salts such as sodium nitrate, making it difficult to obtain a high-quality product with high purity. Therefore, a process for removing them is necessary. One method for this is to dissolve the reactant mixed with various impurities in an aromatic hydrocarbon such as toluene, isolate only the organic layer, and precipitate it in a non-solvent such as methanol to precipitate a high-purity white solid, which is then vacuum-dried. The characteristic of the present invention is that it uses a method of dissolving in an available solvent and then precipitating using a non-solvent, and if this method is used repeatedly, an ultra-high purity product can also be manufactured.

[0041] That is, the present invention proposes a method for easily obtaining silver neodecanoate, a high-quality white product with a purity of 99% or more, by, for example, 1) neutralizing a carboxylic acid such as neodecanoic acid with a base such as sodium hydroxide or ammonia water in water or an alcoholic aqueous solution, adding a silver compound such as silver nitrate thereto to first obtain a white precipitate, dissolving this in an organic solvent such as toluene to separate only the organic layer, and reprecipitating it in methanol, or 2) using a mixed solvent of water and toluene instead of the aqueous solution of 1), then separating only the organic layer, and precipitating it in methanol. If you want to obtain a product with an even higher purity (99.9% or more), you can repeat the process of dissolving the obtained white solid in toluene, reprecipitating it in methanol, and precipitating the solid.

[0042] The present invention is particularly applicable to the production of high-quality carboxylic acid metal salts in aqueous solutions using carboxylic acids having six or more carbon atoms. Among these carboxylic acid metals, the present invention is particularly useful for noble or rare metals such as gold, silver, platinum, palladium, rhodium, and iridium. Among these, the present invention is particularly useful for the production of high-quality silver carboxylates, such as silver neodecanoate.

[0043] Accordingly, according to one aspect of the present invention, a method for producing high-quality silver carboxylate is provided. The method for producing high-quality silver carboxylate comprises the steps of (a) neutralizing a carboxylic acid and a base in a water-containing solvent to form an aqueous solution of a carboxylic acid salt; (b) reacting the carboxylic acid salt with a silver compound to obtain a silver carboxylate product; (c) providing a solution of the silver carboxylate product dissolved in an soluble organic solvent; and (d) precipitating the dissolved silver carboxylate product in a non-solvent to obtain silver carboxylate from which impurities have been removed.

[0044] Figure 1 is a process flow chart showing one embodiment of a method for producing high-quality silver carboxylic acid. Referring to Figure 1, in step S1, a carboxylic acid and a base are neutralized in a water-containing solvent to form an aqueous solution of a carboxylic acid salt. As described above, the carboxylic acid of the present invention preferably has 6 or more carbon atoms in terms of moisture content and the need for purification of impurities accordingly. Preferably, the carboxylic acid has 6 to 30 carbon atoms, and more preferably, the carboxylic acid has 8 to 24 carbon atoms. If the carbon atoms are less than 6, there is no drying property, so a high quality can be obtained even with a general purification method, and if the carbon atoms are more than 30, the silver content is low, which may limit the scope of application.

[0045] The reason why metal carboxylic acids used as drying agents for paints generally have 6 or more carbon atoms is because these compounds have a high moisture content (ability to contain water). Therefore, the features of the present invention are particularly effective when producing high-purity silver carboxylate, but there is no need for special limitation, and even if the carbon atoms are smaller than this, such as silver neopentanoate, if it is a silver carboxylate that is soluble in an aromatic hydrocarbon, such as toluene, as a solvent regardless of the carbon atoms, it can all be applied to the present invention.

[0046] The type of carboxylic acid having 6 or more carbon atoms of the present invention is not particularly limited, but examples thereof include 2-ethylhexanoic acid, neoheptanoic acid, caprylic acid, isononanoic acid, neodecanoic acid, naphthenic acid, behenic acid, abietic acid, and Neo acid 910, Neo acid 913, and Neo acid 928, which are products of ExxonMobil. The content of carboxylic acid is suitably 5 to 90% by weight of the entire reaction mixture, and preferably 10 to 60%.

[0047] Meanwhile, in order to produce silver carboxylic acid by reacting a carboxylic acid and a silver compound, a base is usually used. The base that can be used in the present invention is not particularly limited as long as it is suitable for the present invention, but may include sodium hydroxide, potassium hydroxide, ammonia water, etc., and the amount used is appropriately a molar ratio of carboxylic acid to base of 1:2 to 2:1, preferably 1:1 to 1.5:1.

[0048] The above-mentioned water-containing solvent may be water alone, a mixed solvent of water and a polar solvent, or a mixed solvent of water and a soluble organic solvent. The above-mentioned polar solvent may be, for example, a mixture of one or more alcohols such as water, methanol, ethanol, propanol, isopropanol, butanol, and isobutanol. Among these, methanol, ethanol, propanol, or isopropanol is most suitable in terms of solubility and economy. The above-mentioned soluble organic solvent is not particularly limited as long as it is a solvent capable of dissolving silver carboxylate, but may be an aromatic hydrocarbon. As aromatic hydrocarbons, for example, toluene, xylene, mesitylene, pseudocumene, ethylbenzene, propylbenzene, isopropylbenzene, butylbenzene, diethylbenzene, durene, diisopropylbenzene, tetrahydronaphthalene, methylnaphthalene, vinylnaphthalene, etc. can be used in combination. Among these, toluene, xylene, mesitylene, and especially toluene among them are most suitable for the present invention in terms of solubility and economic feasibility.

[0049] The content of the above-mentioned water-containing solvent is suitably 20 to 90% by weight of the entire reaction mixture, preferably 30 to 80%. When the above-mentioned water-containing solvent is a mixed solvent, the content ratio of water to polar solvent or water to aromatic hydrocarbon need not be particularly limited, but may generally be 10:1 to 1:10, and preferably 5:1 to 1:5. If the amount used is less or more than this, there may be problems such as a decrease in yield or a deterioration in product quality.

[0050] The neutralization reaction can be carried out by slowly adding a base to an aqueous solvent containing the carboxylic acid, or by slowly adding the carboxylic acid to an aqueous solvent containing the base. For example, the addition of the base or carboxylic acid can be carried out by dropwise adding 1000 ml of the base over 20 to 40 minutes.

[0051] After the neutralization reaction, it is recommended to adjust the hydrogen ion concentration (pH) of the final aqueous solution of carboxylic acid salt to slightly acidic to slightly alkaline, for example, pH 6.0 to 8.0, using an acid such as dilute nitric acid. Especially when using strong bases such as sodium hydroxide or potassium hydroxide, the hydrogen ion concentration of the reaction solution has a significant impact on the product quality. For example, if the pH of the reaction solution exceeds 8.0, the reaction yield is good, but the color of the product darkens, and a white product before drying may turn dark brown after drying, so caution is required. If the pH is less than 6.0, although the product color is white, the yield is low. Thus, it is important to adjust the pH of the reaction solution before adding silver nitrate. In addition, it is also necessary to thoroughly wash the white solid obtained after the reaction with water and alcohol to manufacture a high-quality product.

[0052] In step S2, the carboxylic acid salt and the silver compound are reacted to obtain a silver carboxylic acid product. Examples of the silver compound that reacts with the carboxylic acid salt to produce the silver carboxylic acid of the present invention include silver nitrate, silver chloride, and silver sulfate. The content of the silver compound is related to the content of the carboxylic acid salt used. That is, the molar ratio of a carboxylic acid salt having 6 or more carbon atoms, such as neodecanoic acid salt, and a silver compound, such as silver nitrate, is not particularly limited, but a ratio of 1:2 to 2:1, and preferably 1:1 to 1.5:1, is appropriate.

[0053] The above-mentioned silver carboxylic acid product can be produced in two ways depending on the type of solvent. First, there is a method of reacting a carboxylic acid salt and a silver compound using water or a mixed solvent of water and alcohol as a water-containing solvent, whereby the silver carboxylic acid product precipitates in the mixed solvent after the reaction. Second, there is a method of reacting a carboxylic acid salt and a silver compound using water and a soluble organic solvent as a water-containing solvent, whereby the silver carboxylic acid product dissolves in the soluble organic solvent after the reaction. The soluble organic solvent is not particularly limited as long as it is a solvent capable of dissolving the silver carboxylic acid product, but is preferably an aromatic hydrocarbon.

[0054] The reaction temperature does not need to be particularly limited, but is usually suitable at 20 degrees Celsius or higher and 60 degrees Celsius or lower. In step S3, a solution of the silver carboxylic acid product dissolved in a soluble organic solvent is provided. As described above, i) if the soluble organic solvent is already included in the water-containing solvent, the silver carboxylic acid product may be provided in a form in which the silver carboxylic acid product is dissolved in the soluble organic solvent after the reaction, and ii) the precipitate of the silver carboxylic acid product obtained after the reaction may be provided in a form in which the precipitate is dissolved using a separate soluble organic solvent.

[0055] Figure 2 is a schematic diagram showing two processes for producing high-quality silver carboxylic acid. Referring to Figure 2, method i) is to obtain a product by separating only the phase-separated soluble organic solvent and precipitating it in a non-solvent to obtain a solid, and method ii) is to filter and wash the product and vacuum-dry it to obtain a product of general purity (95-97% of existing products), which is then purified again. Both methods can obtain high-quality products. Method i) is a relatively simple process, and method ii) can first obtain a product of general purity, so some of the product can be sold as a product of general purity depending on the intended use, and the rest can be used to obtain high-quality products. To do this, the dried general purity product is dissolved in a soluble solvent (toluene) and then re-precipitated in a non-solvent (methanol), filtered, and vacuum-dried. Alternatively, to obtain a product of general purity in the process, the product is dissolved in a soluble solvent (toluene) in a wet state before filtering, the organic layer is separated, and precipitated in a non-solvent to obtain a high-quality product.

[0056] The two methods above may differ in yield and quality, but in either case, a product with a purity of 99% or more can be obtained.

[0057] In both of the above methods, soluble impurities such as water, unreacted substances, and inorganic salts can be separated from the silver carboxylic acid product soluble in the organic solvent, and the impurities can be removed during the filtration process when the precipitate is formed or during the process of separating the organic layer after dissolving the product in a soluble organic solvent. As a result, the silver carboxylic acid product is separated from the impurities and exists in a form dissolved in the soluble organic solvent. Impurities dissolved in the soluble organic solvent, such as unreacted neodecanoic acid, are separated from the solid product by dissolving in the non-solvent (methanol) during the re-precipitation. In other words, both soluble and water-soluble impurities are removed during this process, resulting in a high-purity, high-quality product.

[0058] The above-mentioned soluble organic solvent may be an aromatic hydrocarbon. The above-mentioned soluble organic solvent may be at least one selected from the group consisting of toluene, xylene, mesitylene, pseudocumene, ethylbenzene, propylbenzene, isopropylbenzene, butylbenzene, diethylbenzene, durene, diisopropylbenzene, tetrahydronaphthalene, methylnaphthalene, and vinylnaphthalene. Preferably, the soluble organic solvent is toluene, xylene, mesitylene, and more preferably toluene, which is advantageous in terms of solubility and economy. The amount of the above-mentioned soluble organic solvent is suitably 50 to 500% by weight, preferably 100 to 300%, relative to the carboxylic acid product.

[0059] In step S4, the dissolved silver carboxylic acid product is reprecipitated in a non-solvent to obtain silver carboxylic acid from which impurities have been removed. In order to obtain a pure product after the reaction, a precipitation method may be used in which the product dissolved in the organic layer, such as the aromatic hydrocarbon, for example, toluene, is precipitated in a non-solvent. Examples of the non-solvent include methanol, ethanol, propanol, isopropanol, butanol, acetone, and acetonitrile, which may be used alone or in combination of one or more solvents. The most suitable non-solvent for the present invention is methanol. The amount of the non-solvent used is suitably 100 to 900%, preferably 200 to 700%, based on the weight of the silver carboxylic acid product dissolved in the soluble organic solvent.

[0060] In some implementations, the steps S3 and S4 may be repeated two or more times to obtain silver carboxylic acid of higher purity.

[0061] Specifically, the present invention provides a method for mass-producing a high-quality silver carboxylic acid having 6 or more carbon atoms, as expressed by [General Formula 1].

[0062] [General Formula 1]

[0063] R1R2R3C-COOAg

[0064] In the above [general formula 1], substituted or unsubstituted C4-C of R1+R2+R3≥C4 20 Alkyl group, substituted or unsubstituted C4-C 28 Cycloalkyl group, substituted or unsubstituted C4-C 28 Aralkyl, substituted or unsubstituted C4-C 28 Heteroalkyl group, substituted or unsubstituted C4-C 28 Heterocycloalkyl group, or substituted or unsubstituted C4-C 28 It is a heteroaralkyl group.

[0065] Specific examples of the silver precursor of the above [general formula 1] include silver 2-ethylbutyrate, silver neoheptanoate, silver 2-ethylhexanoate, silver caprylate, silver isononanoate, silver neodecanoate, silver naphthenate, silver stearate, silver behenate, silver abietate, silver docosanoate, silver oleate, silver linoleate, and silver neo acid 910, a product of Exxon Mobil. 910) and silver neo acid 913 are included here. Among these, among the various carboxylic acid silver salts of the above [general formula 1], alkanoic acid silver such as silver 2-ethylhexanoate, silver isononanoate, silver neodecanoate, silver naphthenate, silver abietic acid, and silver neo acid 913 are preferable, and among these, silver neodecanoate, silver naphthenate, and silver neo acid 913 are useful, and in particular, silver neodecanoate is most suitable for the present invention in terms of economy, applicability, and solubility characteristics.

[0066] As described above, the present invention provides a specific method for producing high-quality silver carboxylate, particularly silver carboxylate having 6 or more carbon atoms, with a purity of 99% or higher, according to a method for producing high-quality silver carboxylate. The method includes adjusting the pH range of an aqueous solution of a carboxylate salt, as well as a process for filtering / washing the precipitate and a process for dissolving / re-precipitating the precipitate. That is, the present manufacturing method can obtain a pure, high-quality white product by, for example, 1) reacting neodecanoic acid as a carboxylic acid, sodium hydroxide, potassium hydroxide, or ammonia water as a reaction base, and water or a mixed solvent of water and alcohol as a solvent to first precipitate the reactant, then dissolving this precipitate in an aromatic hydrocarbon solvent such as toluene, and re-precipitating this solution in methanol, or 2) instead of using water or a mixed solvent of water and alcohol in 1), reacting using a mixture of distilled water and an aromatic hydrocarbon, for example, an organic solvent such as toluene, and separating the organic layer after the reaction and precipitating it in methanol, thereby obtaining a high-quality product.

[0067] Although the present invention exemplifies a case where silver carboxylic acid is used among metal carboxylic acids, there is no need to specifically limit other metals as long as they are suitable for the present invention. For example, it can also be used to produce carboxylic acid metal salts of metals such as lithium, sodium, and potassium, alkaline earth metals such as magnesium and calcium, and metals such as cobalt, manganese, nickel, lead, zinc, zirconium, hafnium, aluminum, gallium, germanium, tin, iron, copper, bismuth, indium, antimony, chromium, vanadium, niobium, molybdenum, tungsten, rhenium, tantalum, osmium, titanium, iridium, neodymium, and yttrium, and especially, high-purity carboxylic acid metal salts of rare metals such as gold, palladium, platinum, rhodium, and ruthenium.

[0068] Hereinafter, the present invention will be described in more detail through examples. However, these examples are merely illustrative of the present invention and are not intended to limit the scope of the present invention. In the manufacturing examples and examples below, "water" refers to deionized water, and unless otherwise specified, all experiments were conducted at a room temperature of 25°C.

[0069] [Example]

[0070] Example 1.

[0071] In a 3.0-liter, transparent, three-necked flask equipped with a stirrer, 500 grams of water was placed. While stirring, 40 grams of sodium hydroxide (NaOH) was slowly added until completely dissolved. To the transparent solution, 500 grams of isopropanol and 172 grams of neodecanoic acid were gradually added sequentially and reacted for an additional 3 hours. Finally, the pH of the mixture was adjusted to 6.8. A mixed solution of 168 grams of silver nitrate (AgNO3) dissolved in 300 grams of water was slowly added dropwise to the stirred solution over a period of 30 minutes, resulting in the precipitation of a white solid. This was filtered and washed thoroughly with water and isopropanol. The obtained white solid was dissolved in 500 grams of toluene and only the organic layer was separated. This organic layer was slowly added dropwise to 1,500 grams of methanol while stirring, resulting in the precipitation of a white solid. The solid thus obtained was filtered, washed thoroughly with methanol, and dried in a vacuum oven at 50°C for 24 hours to obtain 250 grams of silver neodecanoate as a white solid. Analysis using an inductively coupled plasma optical spectroscopy (ICP-OES) revealed that the purity was 99.7%.

[0072] Figure 3 is a photograph of the product of silver neodecanoate manufactured in Example 1. Referring to Figure 3, it can be seen that the obtained product is a uniform white powder. Meanwhile, Figure 4 is a thermogravimetric analyzer graph of silver neodecanoate manufactured in Example 1, Figure 5 is a differential scanning calorimetry graph of silver neodecanoate manufactured in Example 1, and Figure 6 is a hydrogen nuclear magnetic resonance spectrum (of silver neodecanoate and neodecanoic acid manufactured in Example 1) 1 H-NMR Spectrum in Toluene-D8) data. Referring to Figures 4 to 6, it can be seen that the obtained product has thermal behavior characteristics and molecular structural formula corresponding to silver neodecanoate.

[0073] Example 2.

[0074] A white solid of silver neodecanoate weighing 245 grams was obtained by the same method as in Example 1, except that methanol was used instead of isopropanol. The purity of this was found to be 99.5% when analyzed using an inductively coupled plasma optical spectroscopy (ICP-OES).

[0075] Example 3.

[0076] A method similar to Example 1 was followed, except that 70 grams of 28% ammonia water (NH4OH) was used instead of 40 grams of sodium hydroxide in Example 1. As a result, 235 grams of silver neodecanoate as a white solid was obtained. The purity was found to be 99.7% when analyzed using an inductively coupled plasma optical scanning electron microscope (ICP-OES).

[0077] Example 4.

[0078] A method similar to Example 1 was followed, except that 70 grams of 28% ammonia water and methanol were used instead of 40 grams of sodium hydroxide and isopropanol in Example 1. As a result, 240 grams of silver neodecanoate as a white solid was obtained. The purity was found to be 99.6% when analyzed using an inductively coupled plasma optical scanning electron microscope (ICP-OES).

[0079] Example 5.

[0080] 1,000 grams of water was placed in a 3.0-liter, transparent, three-necked flask equipped with a stirrer. 40 grams of sodium hydroxide was slowly added while stirring until completely dissolved. 172 grams of neodecanoic acid was slowly added to the resulting clear solution, and the reaction was continued for 3 hours. Finally, the pH of the mixture was adjusted to 6.5. A mixed solution of 168 grams of silver nitrate dissolved in 300 grams of water was slowly added dropwise to the stirred solution over 30 minutes, resulting in the precipitation of a white solid. To purify the precipitated solid, it was filtered and washed thoroughly with water. The remaining white solid was dissolved in 500 grams of toluene. The organic layer was separated, and this was slowly added dropwise while stirring to a reactor containing 1,500 grams of methanol, resulting in the precipitation of a white solid. The precipitated solid was filtered, washed thoroughly with methanol, and 50 o After drying in a vacuum oven at C for 24 hours, 255 grams of neodecanoic acid as a white solid were obtained. The purity was 99.5% when analyzed using an inductively coupled plasma optical spectroscopy (ICP-OES).

[0081] Example 6.

[0082] 1000 grams of water was placed in a 3.0-liter transparent three-necked flask equipped with a stirrer, 172 grams of neodecanoic acid was added while stirring, and then 70 grams of 28% ammonia water was slowly added. After stirring for 6 hours, a mixed solution of 168 grams of silver nitrate dissolved in 300 grams of water was slowly dropped over 30 minutes, and a white, slightly sticky solid precipitated. After separating the aqueous layer, the remaining solid was dissolved using 500 grams of toluene. Only the organic layer was separated again, and this was slowly dropped into a reactor containing 1500 grams of methanol while stirring, and a white solid precipitated. After filtering, it was washed with methanol and 50 oAfter drying in a vacuum oven at C for 24 hours, 235 grams of neodecanoic acid as a white solid were obtained. The purity was 99.6% when analyzed using an inductively coupled plasma optical spectroscopy (ICP-OES).

[0083] Example 7.

[0084] In a 3.0-liter, transparent, three-necked flask equipped with a stirrer, 1,000 grams of water was placed. 40 grams of sodium hydroxide was slowly added while stirring to completely dissolve the solution. To the transparent solution, 500 grams of toluene and 172 grams of neodecanoic acid were gradually added sequentially and reacted for 3 hours. Finally, the hydrogen ion concentration of the mixture was adjusted to 6.7. A mixed solution of 168 grams of silver nitrate dissolved in 300 grams of water was slowly added dropwise to the stirred solution over 30 minutes and the mixture was reacted for an additional 1 hour and 30 minutes. When stirring was stopped, the organic layer and the aqueous layer separated. After separating only the organic layer, it was slowly added dropwise to a container containing 1,500 grams of methanol while stirring well, resulting in the precipitation of a white solid. The solid thus obtained was filtered, washed with methanol, and quenched with 50 o After drying in a vacuum oven at C for 24 hours, 245 grams of a white solid were obtained. The purity was 99.3% when analyzed using an inductively coupled plasma optical spectroscopy (ICP-OES).

[0085] Example 8.

[0086] A white solid silver neodecanoate weighing 240 grams was obtained in the same manner as in Example 7, except that 56 grams of potassium hydroxide (KOH) was used instead of 40 grams of sodium hydroxide. The purity was found to be 99.4% when analyzed using an inductively coupled plasma optical spectroscopy (ICP-OES).

[0087] Example 9.

[0088] A white solid silver neodecanoate weighing 235 grams was obtained in the same manner as in Example 7, except that 70 grams of 28% ammonia water was used instead of 40 grams of sodium hydroxide. The purity was found to be 99.6% when analyzed using an inductively coupled plasma optical scanning electron microscope (ICP-OES).

[0089] Example 10.

[0090] A white solid of silver neodecanoate weighing 230 grams was obtained by the same method as in Example 7, except that xylene was used instead of toluene. The purity was found to be 99.5% when analyzed using an inductively coupled plasma optical scanning electron microscope (ICP-OES).

[0091] Comparative Example 1.

[0092] 1000 grams of water was placed in a 3.0-liter transparent three-necked flask equipped with a stirrer, and 40 grams of sodium hydroxide was slowly added while stirring to completely dissolve it. 172 grams of neodecanoic acid was gradually added to the resulting transparent solution, and the hydrogen ion concentration of the mixture was finally adjusted to 6.5. A mixed solution of 168 grams of silver nitrate dissolved in 300 grams of water was slowly dropped into the stirred mixed solution over 30 minutes, resulting in the precipitation of a white solid. This solid was thoroughly washed with water, filtered, and 50 o After drying in a vacuum oven at C for 24 hours, 260 grams of a white solid were obtained. The purity was 95.5% when analyzed using an inductively coupled plasma optical spectroscopy (ICP-OES).

[0093] Fig. 7 is a photograph of the product of silver neodecanoate manufactured in Comparative Example 1. Referring to Fig. 7, it can be seen that the obtained product is a non-uniform, off-white powder. And Fig. 8 is a differential scanning calorimetry graph of silver neodecanoate manufactured in Comparative Example 1. Referring to Fig. 8, it can be seen that the thermal behavior characteristics of the obtained product are different from the differential scanning calorimetry graph (Fig. 5) of silver neodecanoate manufactured in Example 1.

[0094] Comparative Example 2.

[0095] In a 2.0-liter flask equipped with a stirrer, 250 grams of toluene and 258 grams of neodecanoic acid were added. While stirring, 116 grams of silver oxide was slowly dropped in over the course of one hour. The black silver oxide gradually dissolved and reacted, ultimately obtaining a brown solution. The reaction was continued while stirring for another hour, filtered, and the solution was slowly dropped into 1,000 grams of methanol while stirring, resulting in the precipitation of a solid. The solid was filtered, washed thoroughly with methanol, and dried in a vacuum oven at 50°C for 24 hours to obtain 240 grams of a light brown solid. The purity was 97.9% when analyzed using an inductively coupled plasma optical emission spectrometer (ICP-OES).

[0096] Fig. 9 is a photograph of the product of silver neodecanoate manufactured in Comparative Example 2. Referring to Fig. 9, it can be seen that the obtained product is a uniform light brown powder. And Fig. 10 is a differential scanning calorimetry graph of silver neodecanoate manufactured in Comparative Example 1. Referring to Fig. 10, it can be seen that the thermal behavior characteristics of the obtained product are intermediate between the differential scanning calorimetry graph of silver neodecanoate manufactured in Example 1 (Fig. 5) and the differential scanning calorimetry graph of silver neodecanoate manufactured in Comparative Example 1 (Fig. 8).

Claims

1. (a) A step of neutralizing a carboxylic acid and a base in a water-containing solvent to form an aqueous solution of a carboxylic acid salt; (b) a step of reacting the carboxylic acid salt and a silver compound to obtain a silver carboxylic acid product; (c) providing a solution of the carboxylic acid product dissolved in an available organic solvent; and (d) A method for producing high-quality silver carboxylate, comprising the step of precipitating the dissolved silver carboxylate product in a non-solvent to obtain silver carboxylate from which impurities have been removed.

2. In paragraph 1, A method for producing high-quality silver carboxylic acid, wherein the water-containing solvent is water alone, a mixed solvent of water and a polar solvent, or a mixed solvent of water and a soluble organic solvent.

3. In paragraph 1, A method for producing high-quality silver carboxylic acid, wherein the carboxylic acid has 6 or more carbon atoms.

4. In paragraph 1, A method for producing high-quality silver carboxylic acid, wherein the above carboxylic acid and base have a molar ratio of 1:2 to 2:

1.

5. In paragraph 1, A method for producing high-quality silver carboxylic acid, wherein the pH of the aqueous solution is adjusted to 6.0 to 8.

0.

6. In paragraph 1, A method for producing high-quality silver carboxylate, wherein the above carboxylate salt and silver compound have a molar ratio of 1:2 to 2:

1.

7. In paragraph 1, A method for producing high-quality silver carboxylate, wherein the solution of step (c) is provided in the form of dissolving the silver carboxylate product precipitated in the water-containing solvent of step (b) in a separate soluble organic solvent.

8. In paragraph 7, A method for producing high-quality silver carboxylic acid, further comprising a step of washing the silver carboxylic acid product with water and alcohol after the step (b).

9. In paragraph 1, A method for producing high-quality silver carboxylic acid, wherein the solution of step (c) is a mixed solvent in which the water-containing solvent of step (a) further includes the soluble organic solvent, and the silver carboxylic acid product is provided in a form dissolved in the soluble organic solvent after the reaction.

10. In paragraph 1, A method for producing high-quality silver carboxylic acid, wherein the above-mentioned available organic solvent is an aromatic hydrocarbon.

11. In paragraph 10, A method for producing high-quality silver carboxylic acid, wherein the aromatic hydrocarbon is at least one selected from the group consisting of toluene, xylene, and mesitylene.

12. In paragraph 1, A method for producing high-quality silver carboxylic acid, wherein the non-solvent is at least one selected from the group consisting of methanol, ethanol, propanol, isopropanol, butanol, acetone, and acetonitrile.

13. In paragraph 12, A method for producing high-quality silver carboxylic acid, wherein the non-solvent is methanol.

14. In paragraph 1, A method for producing high-quality silver carboxylate, wherein the amount of the non-solvent is 100 to 900% of the weight of the silver carboxylate product dissolved in the available organic solvent.

15. In paragraph 1, A method for producing high-quality silver carboxylic acid, wherein the dissolution and precipitation processes of steps (c) and (d) are repeated two or more times.

16. In paragraph 1, The above silver carboxylic acid is a method for producing high-quality silver carboxylic acid represented by the following general formula 1: [General Formula 1] R1R2R3C-COOAg In the above [general formula 1], substituted or unsubstituted C4-C of R1+R2+R3≥C4 20 Alkyl group, substituted or unsubstituted C4-C 28 Cycloalkyl group, substituted or unsubstituted C4-C 28 Aralkyl, substituted or unsubstituted C4-C 28 Heteroalkyl group, substituted or unsubstituted C4-C 28 Heterocycloalkyl group, or substituted or unsubstituted C4-C 28 It is a heteroaralkyl group.

17. Silver carboxylic acid having a purity of 99% or more, manufactured by any one of the methods of clauses 1 to 16.

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