Method for preparing chelatable EDDHA

Abstract

The present invention relates to a method for preparing chelatable EDDHA, and more particularly, to a method for preparing chelatable EDDHA with high purity at an excellent yield.

Description

TECHNICAL FIELD

[0001] The present invention relates to a method for preparing chelatable EDDHA, and more particularly, to a method for preparing chelatable EDDHA in high purity at an excellent yield. BACKGROUND

[0002] EDDHA (ethylene diamine-N,N'-bis(2-hydroxyphenylacetic acid)) is a chelating agent, which is a hexadentate ligand, and can bind to metal ions through six binding sites of two amine, two phenol centers, and two carboxylate.

[0003] The known synthesis method of EDDHA is to react phenol, ethylene diamine, glyoxylic acid, sodium hydroxide, and the like at 70 to 75°C, and then precipitate the product at room temperature for 72 hours or more (Structure and Fertilizer Properties of Byproducts Formed during Synthesis of EDDHA, Journal of Agricultural and Food Chemistry, 2006, Vol. 54, pp. 4355-4363).

[0004] However, the above reaction requires a precipitation time of at least three days to collect the generated product, and since this process takes a relatively long time, it is difficult to produce chelatable EDDHA on an economic and industrial scale, and in addition, the product prepared using the above method contains a large amount of residues and other byproducts, and thus requires the use of other organic solvents for purification of the product, thereby causing a problem of additional waste liquid.

[0005] In addition, chelatable EDDHA has a strong affinity for specific metal ions, and can be applied to a substrate surface cleaning agent, a resist stripper, a chemical mechanical polishing slurry, an etchant, and the like in a semiconductor process, and since the semiconductor process is greatly affected by impurities, the prepared EDDHA needs to be synthesized as a high-purity compound free of unnecessary metals to be used in the semiconductor process.

[0006] Therefore, there is an urgent need to develop a new method for preparing chelatable EDDHA in high purity at an excellent yield. SUMMARY

[0007] TECHNICAL PROBLEM

[0008] The present invention aims to provide a method for synthesizing chelatable EDDHA in high purity at an excellent yield.

[0009] According to the present invention, chelatable EDDHA can be economically and industrially produced by synthesizing a mixture of substituted or unsubstituted phenol, ethylene diamine, glyoxylic acid, and sodium hydroxide, simultaneously heating to a predetermined temperature to provide sufficient thermal energy required for the synthesis reaction, and precipitating by heating at a specific temperature to improve the yield of the product.

[0010] Further, the chelatable EDDHA product prepared using the preparation method has low metal content and can be used for various purposes in semiconductor processes.

[0011] Technical Solution

[0012] One embodiment of the present application provides a method of preparing chelatable EDDHA, the method comprising the steps of:

[0013] mixing a substituted or unsubstituted phenol, ethylenediamine, glyoxylic acid, and sodium hydroxide (S1);

[0014] reacting the mixture at 75 to 80°C to synthesize a product (S2);

[0015] heating the product to 55 to 65°C to collect the product (S3); and

[0016] washing the collected product with a washing solution comprising deionized water (S4).

[0017] In step (S2), the mixture can be reacted at 75 to 80°C for 2 to 4 hours to synthesize the product.

[0018] In step (S3), the product can be heated at 55 to 65°C for 30 minutes to 2 hours to collect the product.

[0019] The concentration of the sodium hydroxide can be 35 to 50 wt%.

[0020] The synthesis yield of the product prepared using the preparation method can be 18% or more.

[0021] The content of Al and Fe in the product prepared using the preparation method can each be 5 ppm or less.

[0022] The content of K and Ca in the product prepared using the preparation method can each be 5 ppm or less.

[0023] The content of Na in the product prepared using the preparation method can be 40 ppm or less.

[0024] The washing solution can further comprise an additive selected from the group consisting of an organic solvent containing acetone, an organic base containing NH4OH, inorganic acids containing HNO3 and HCl, or a combination thereof.

[0025] The washing solution can comprise deionized water and an additive in a weight ratio of 5:1 to 20:1, the additive being selected from the group consisting of an organic solvent containing acetone, an organic base containing NH4OH, inorganic acids containing HNO3 and HCl, or a combination thereof.

[0026] Advantageous Effects

[0027] The method for preparing the EDDHA chelate according to the present application can produce the EDDHA chelate with high purity at an excellent yield.

[0028] In addition, the EDDHA product obtained by the method has a low metal content and can be used for various purposes in semiconductor processes. DETAILED DESCRIPTION

[0029] Unless defined otherwise herein, all technical and scientific terms used have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0030] As used in the specification and the appended claims, the singular forms "a," "an" and "the" include plural referents unless the context clearly dictates otherwise.

[0031] As used in the specification and the appended claims, the term "comprising" designates the presence of the specific features, regions, integers, steps, operations, elements, and / or components but does not exclude the presence or addition of one or more other specific features, regions, integers, steps, operations, elements, components, and / or groups thereof.

[0032] The present application can have various modifications as appropriate and can have various forms, and specific embodiments will be described and explained in detail below. However, this is not intended to limit the present application to a specific inventive form, and needs to be interpreted to include all modifications, equivalents, and alternatives contained in the scope of the objects and technical scope.

[0033] In the present specification, when a positional relationship between two parts is described as, for example, "in", "in the upper half of", "in the lower half of", "close to", and the like, one or more other parts can be located between the two parts, unless expressions such as "facing" or "directly" are used.

[0034] In the present specification, when a temporal relationship is described as, for example, "after", "later", "then", "before", and the like, it can include a case where the operations are not continuous, unless expressions such as "immediately" or "directly" are used.

[0035] In the present specification, the term "at least one" needs to be interpreted to include all combinations that can be presented by one or more relevant items.

[0036] Hereinafter, a method for preparing an EDDHA chelate according to a specific embodiment of the present application will be described in more detail.

[0037] According to one embodiment of the present application, there is provided a method of preparing EDDHA chelate, comprising: mixing substituted or unsubstituted phenol, ethylenediamine, glyoxylic acid and sodium hydroxide (S1); reacting the mixture at 75 to 80°C to synthesize a product (S2); heating the product to 55 to 65°C to collect the product (S3); and washing the collected product with a washing solution containing deionized water (S4).

[0038] As shown in Reaction Formula 1, EDDHA can be industrially produced through a Mannich-like reaction between substituted or unsubstituted phenol, ethylenediamine, glyoxylic acid and sodium hydroxide.

[0039] [Reaction Formula 1]

[0040]

[0041] Among them, the synthesis of EDDHA mainly generates component A, while a mixture of positional isomers B and C is also generated, and the amount of other by-products varies with the reaction conditions.

[0042] A is ethylenediamine-N,N'-di(2-hydroxyphenylacetic acid), abbreviated as o,o-EDDHA, which is a chelatable EDDHA capable of forming a hexadentate ligand by binding with metal ions.

[0043] B is 2-((2-((carboxy(2-hydroxyphenyl)methyl)amino)ethyl)amino)-2-(4-hydroxyphenyl)acetic acid, abbreviated as o,p-EDDHA, and can be chelated with metal ions by including a structure in which the phenyl group is substituted with a hydroxyl group in the ortho direction.

[0044] C is 2,2'-(ethane-1,2-diylbis(azanediyl))bis(2-(4-hydroxyphenyl)acetic acid), abbreviated as p,p-EDDHA, which cannot be chelated with metal ions due to having a structure in which all phenyl hydroxyl groups are substituted in the para position.

[0045] In other words, A, B and C can all be referred to as compounds of EDDHA, but only A and B can be chelated with metal ions. Therefore, the chelatable EDDHA prepared in the present application specifically refers to A and B, and does not include C.

[0046] The existing EDDHA synthesis method is to react phenol, ethylenediamine, glyoxylic acid and sodium hydroxide reactants at 70 to 75°C, and then precipitate at room temperature for 72 hours or more to obtain the product.

[0047] However, the reaction requires at least three days of precipitation time after synthesis to collect the product, since the process time is relatively long, the product prepared using the above method contains a large amount of residues and other by-products, and additional organic solvents are used to purify the product, thereby causing an additional waste liquid problem.

[0048] Therefore, to solve the above problems, the present inventors determined that EDDHA can be synthesized with a more excellent yield by synthesizing a mixture of substituted or unsubstituted phenol, ethylenediamine, glyoxylic acid, and sodium hydroxide while increasing the temperature to a specific temperature, thereby applying sufficient thermal energy required for the synthesis reaction, and improving the product yield by precipitating at a certain temperature by heating, thereby economically and industrially producing high-purity chelatable EDDHA, and completed the present invention.

[0049] According to the present invention, when a mixture of substituted or unsubstituted phenol, ethylenediamine, glyoxylic acid, and sodium hydroxide is mixed (step S1), and then the mixture is reacted at 75 to 80°C to synthesize a product (step S2), EDDHA can be prepared with an excellent yield, compared to the reaction conditions of 70 to 75°C known in the prior art.

[0050] The effect is believed to be due to the fact that when the reaction is performed at a temperature of about 5°C or more higher than the average of 70 to 75°C known in the prior art, sufficient thermal energy required for the reaction can be obtained, and the moisture content in the reaction material is reduced as the reaction temperature increases.

[0051] When the reaction temperature is higher than 80°C, the thermal energy required for the reaction is sufficient, but the amount of heat applied is excessive, which can cause the synthesized compound to be thermally decomposed or increase other by-products, thereby reducing the yield of chelatable EDDHA to be synthesized.

[0052] Here, the step of reacting and synthesizing a product at 75 to 80°C (S2) can be performed for about 2 to 4 hours, preferably for about 2 hours and 30 minutes to 3 hours and 30 minutes, and more preferably for about 3 hours.

[0053] When the reaction time is less than 2 hours, the time required for the synthesis of the product is insufficient, thereby reducing the reaction yield, and the reaction time should not be greater than 4 hours because EDDHA can be polymerized to become an unusable by-product.

[0054] Here, the concentration of sodium hydroxide can be 35 to 50 wt%, and preferably 40 to 50 wt%.

[0055] In the present application, a 35 wt% to 50 wt% aqueous sodium hydroxide solution is used, while a 30 wt% aqueous sodium hydroxide solution is used in the related art. Specifically, the concentration of sodium hydroxide can not be 30 wt% or more at room temperature, however, the heat generated during mixing of sodium hydroxide with water is used to prepare a 50 wt% aqueous sodium hydroxide solution without additional energy, thereby improving the synthesis efficiency.

[0056] Meanwhile, due to the addition of sodium hydroxide, the mixture obtained by mixing the substituted or unsubstituted phenol, ethylenediamine, glyoxylic acid, and sodium hydroxide can react under conditions in which the pH is about 8 to 10.

[0057] The chelatable EDDHA containing o,o-EDDHA and o,p-EDDHA synthesized through the synthesis reaction of step (S2) is dissolved in a solvent, and can be heated to 55°C to 80°C to collect the product (step S3).

[0058] In the related prior art, in order to remove the organic solvent in the product separation process to obtain a precipitate, it is generally necessary to allow the reaction material to stand at room temperature for 72 hours or more, and then filter the precipitate to obtain the final product. However, this method is economically inefficient due to the excessively long time taken to obtain the product, and the organic solvent is not sufficiently removed in the product separation process, making it difficult to achieve industrial-scale production of high-purity EDDHA.

[0059] The inventors of the present application determined that, when the product synthesized in step (S2) is heated at a temperature in the range of 55°C to 65°C for a certain period of time, the time required to collect the product can be significantly shortened.

[0060] In other words, when the product is collected at about 55°C to 65°C, preferably about 60°C, the synthesis product is not decomposed, and thus the organic solvent can be removed at a high speed with thermal stability, and in this process, by-products and impurities are also simultaneously removed, so that a high-purity product can be collected.

[0061] For example, in the process of collecting the synthesis product by separation by layering, dichloromethane (CH2Cl2) can be used as the organic solvent. When heated to 55°C to 65°C, the remaining dichloromethane can be removed in the form of boiling. When heated to 55°C to 65°C, unreacted phenol is additionally removed due to increased volatility.

[0062] Here, the step (S3) of collecting the product by heating the product to 55°C to 65°C can be performed for about 30 minutes to 2 hours, preferably about 1 hour to 1 hour and 30 minutes, and more preferably about 1 hour.

[0063] If the collection time is less than 30 minutes, the organic solvent is not sufficiently removed, and the product cannot be sufficiently obtained; the collection time is preferably not more than 2 hours, because the product can be decomposed.

[0064] The method for preparing the EDDHA-chelatable product according to the present application further includes a step (S4) of washing the collected product using a washing solution containing deionized water.

[0065] Through the step (S4), the remaining metal and synthesis residue in the product can be further removed, thereby preparing the EDDHA-chelatable product with higher purity.

[0066] Here, the washing solution can further include an additive selected from the group consisting of an organic solvent including acetone, an organic base including NH4OH, an inorganic acid including HNO3 and HCl, or a combination thereof.

[0067] The additive mainly functions to remove metal contaminants in the form of ions.

[0068] Specifically, the deionized water and the additive are mixed at a weight ratio of 5:1 to 20:1, preferably 7:1 to 15:1, and more preferably 8:1 to 12:1, wherein the additive is selected from the group consisting of an organic solvent including acetone, an organic base including NH4OH, an inorganic acid including HNO3 and HCl, or a combination thereof.

[0069] According to the preparation method according to the present application, the yield of the prepared EDDHA-chelatable product can be 18% or more, preferably 19% or more, and more preferably 20% or more, and the purity can be 90% or more, preferably 95% or more, and more preferably 97% or more.

[0070] According to the preparation method according to the present application, by synthesizing a mixture of substituted or unsubstituted phenol, ethylenediamine, glyoxylic acid, and sodium hydroxide while being heated to a predetermined temperature, sufficient heat energy required for the synthesis reaction is applied, thereby reducing byproducts, and by heating and precipitating at a certain temperature, the byproducts and contaminants are removed, thereby preparing a high-purity product.

[0071] For example, the amount of Al and Fe contained in the product prepared using the preparation method can each be 5 ppm or less, preferably 3 ppm or less, and more preferably 2 ppm or less.

[0072] In addition, the amount of K and Ca contained in the product prepared using the preparation method can each be 5 ppm or less, preferably 4 ppm or less, and more preferably 3 ppm or less.

[0073] The amount of Na contained in the product prepared using the preparation method can be 40 ppm or less, preferably 35 ppm or less, and more preferably 30 ppm or less.

[0074] In the synthesis of EDDHA, sodium Na metal impurities can remain in the obtained EDDHA product due to the use of sodium hydroxide as a reaction raw material. The sodium content in the product can be effectively reduced to 40 ppm or less by the preparation method described in the present application, and thus the preparation method of the present application is preferably used to synthesize EDDHA.

[0075] In other words, the chelatable EDDHA product obtained by the preparation method has low metal content and can be used for various purposes in semiconductor processes.

[0076] Hereinafter, embodiments of the present application will be described in more detail with reference to the following examples. However, the following examples are only for illustrating embodiments of the present application, and the present application is not limited by the following examples.

[0077] (1) Example 1

[0078] In a two-necked round bottom flask equipped with a reflux condenser and a magnetic stirring bar, phenol (100.0 g, 1.063 mol) was dissolved at 40-45 °C, and then dry ethylenediamine (2.46 g, 40.9 mmol) was added, and the mixture was stirred for 10 minutes.

[0079] To the stirred mixture, 50% NaOH (3.33 g, 40.9 mmol) and 50% glyoxylic acid solution (12.12 g, 81.8 mmol) were slowly added dropwise.

[0080] The mixture was heated to 75-80 °C for 3 hours to synthesize the product. After the temperature was lowered to room temperature, water (120 mL) and CH2Cl2(240 mL) were added, and the resulting mixture was stirred for 10 minutes.

[0081] Subsequently, the resulting mixture was heated in a constant temperature water bath at 60 °C for 1 hour, and then the precipitated product was collected by filtration.

[0082] Deionized water was mixed with the obtained product at a weight ratio of 10:1, and after stirring for 20 minutes, it was separated, washed, and dried at 60 °C to obtain a mixture of o,o-EDDHA and o,p-EDDHA (3.45 g).

[0083] (2) Example 2

[0084] A mixture of o,o-EDDHA and o,p-EDDHA (3.45 g) was obtained using the same method as in Example 1, except that deionized water was mixed with acetone (Sigma Aldrich) at a weight ratio of 10:1 and used.

[0085] (3) Example 3

[0086] A mixture of o,o-EDDHA and o,p-EDDHA (3 g) was obtained using the same method as in Example 1, except that 33% NaOH (5 g, 40.9 mmol) was used as sodium hydroxide.

[0087] (4) Comparative Example 1

[0088] A mixture of o,o-EDDHA and o,p-EDDHA (2.4 g) was obtained using the same method as in Example 1, except that the mixture of phenol, ethylenediamine, glyoxylic acid and sodium hydroxide was heated at 70°C to 75°C for 3 hours.

[0089] (5) Comparative Example 2

[0090] A mixture of o,o-EDDHA and o,p-EDDHA (2.1 g) was obtained using the same method as in Example 1, except that the mixture of phenol, ethylenediamine, glyoxylic acid and sodium hydroxide was heated at 80°C to 85°C for 3 hours.

[0091] (6) Comparative Example 3

[0092] A mixture of o,o-EDDHA and o,p-EDDHA (1.95 g) was obtained using the same method as in Example 1, except that the mixture of phenol, ethylenediamine, glyoxylic acid and sodium hydroxide was heated at 85°C to 90°C for 3 hours.

[0093] (7) Comparative Example 4

[0094] In a two-necked round bottom flask equipped with a reflux condenser and a magnetic stir bar, phenol (100.0 g, 1.063 mol) was dissolved at 40°C to 45°C, then dry ethylenediamine (2.46 g, 40.9 mmol) was added and the mixture was stirred for 10 minutes.

[0095] To the stirred mixture, 33% NaOH (4.97 g, 40.9 mmol) and 50% glyoxylic acid solution (12.12 g, 81.8 mmol) were added slowly dropwise.

[0096] The mixture was heated to 75°C to 80°C for 3 hours to synthesize the product. After the temperature was reduced to room temperature, water (120 mL) and CH2Cl2(240 mL) were added and the resulting mixture was stirred for 10 minutes.

[0097] Subsequently, the resulting mixture was left to stand at room temperature for 72 hours (3 days) and then the precipitated product was collected by filtration.

[0098] Deionized water was mixed with the resulting product in a 10:1 weight ratio, and after stirring for 20 minutes, it was separated, washed and dried at 60°C to obtain a mixture of o,o-EDDHA and o,p-EDDHA (1.65 g).

[0099] Room temperature refers to the natural temperature without heating or cooling, and generally indicates a temperature in the range of 20±5°C.

[0100] (8) Comparative Example 5

[0101] A mixture of o,o-EDDHA and o,p-EDDHA (2.1 g) was obtained using the same method as Comparative Example 4, except that the resulting mixture was left to stand at room temperature for 168 hours (7 days).

[0102] The yield and purity of each product in the examples and comparative examples are calculated and listed in Table 1 below. The purity of the product can be determined by NMR and IR analysis, and for IR, the purity can be determined by the matching rate (%) of peak matching.

[0103]

Table 1

[0104]

[0105]

[0106] As can be determined from Table 1, when synthesizing chelatable EDDHA using the preparation method according to the present application, by mixing substituted or unsubstituted phenol, ethylenediamine, glyoxylic acid, and sodium hydroxide, while simultaneously increasing the temperature to a predetermined temperature to provide sufficient thermal energy required for the synthesis reaction, EDDHA can be synthesized in excellent yield and purity; and by heating precipitation at a specific temperature to increase the yield of the product, efficient preparation of chelatable EDDHA can be achieved.

[0107] (9) Comparative Example 6

[0108] In a two-necked round bottom flask equipped with a reflux condenser and a magnetic stirring rod, phenol (100.0 g, 1.063 mol) was dissolved at 40°C to 45°C, and then dry ethylenediamine (2.46 g, 40.9 mmol) was added, and the mixture was stirred for 10 minutes.

[0109] To the stirred mixture, 50% NaOH (3.33 g, 40.9 mmol) and a 50% glyoxylic acid solution (12.12 g, 81.8 mmol) were slowly added dropwise.

[0110] The mixture was heated to react at 75°C to 80°C for 3 hours to synthesize the product. After the temperature decreased to room temperature, water (120 mL) and CH2Cl2(240 mL) were added, and the resulting mixture was stirred for 10 minutes.

[0111] Subsequently, the resulting mixture was heated in a constant temperature water bath at 60°C for 1 hour, and then the precipitated product was collected by filtration to obtain a mixture of o,o-EDDHA and o,p-EDDHA (3.45 g).

[0112] (10) Comparative Example 7

[0113] In a double necked round bottom flask equipped with a reflux condenser and a magnetic stir bar, phenol (100.0 g, 1.063 mol) was dissolved at 40-45 °C, then anhydrous ethylenediamine (2.46 g, 40.9 mmol) was added and the mixture was stirred for 10 minutes.

[0114] To the stirred mixture, 50% NaOH (3.33 g, 40.9 mmol) and 50% glyoxylic acid solution (12.12 g, 81.8 mmol) were added slowly dropwise.

[0115] The mixture was heated to 75-80 °C for 3 hours to synthesize the product. After the temperature dropped to room temperature, water (120 mL) and CH2Cl2(240 mL) were added and the resulting mixture was stirred for 10 minutes.

[0116] Subsequently, the resulting mixture was left to stand at room temperature for 72 hours (3 days) and then the precipitated product was collected by filtration to obtain a mixture of o,o-EDDHA and o,p-EDDHA (1.6 g).

[0117] The metal content of the products obtained in Example 1, Comparative Example 6 and Comparative Example 7 was analyzed and the results are shown in Table 2 below.

[0118] The metal content of EDDHA was analyzed after wet decomposition of EDDHA using the following method. Specifically, EDDHA (0.1 g) was decomposed with 70% nitric acid (10 mL) in an Anton parr MULTIWAVE 5000 60HZ PACKAGE 24HVT80, then collected with 3% nitric acid and analyzed for metal content using ICP-MS 8900.

[0119] [Table 2]

[0120]

[0121]

[0122] As can be seen from Table 2, when chelatable EDDHA is prepared according to the preparation method described in the present application, the metal present in the product and the synthesis residues are additionally removed, and chelatable EDDHA with higher purity is prepared.

Claims

1. A method for preparing chelatable EDDHA, the method comprising the following steps: A mixture of phenol, ethylenediamine, glyoxylic acid, and sodium hydroxide (S1); The product (S2) was synthesized by reacting the mixture at 75°C to 80°C. The product is heated to 55°C to 65°C to collect the product (S3); and The collected product was washed with a washing solution containing deionized water (S4).

2. The method as described in claim 1, characterized in that, In step (S2), the mixture is reacted at 75°C to 80°C for 2 to 4 hours to synthesize the product.

3. The method as described in claim 1, characterized in that, In step (S3), the product is heated at 55°C to 65°C for 30 minutes to 2 hours to collect the product.

4. The method as described in claim 1, characterized in that, The concentration of sodium hydroxide is 35 wt% to 50 wt%.

5. The method as described in claim 1, characterized in that, The synthetic yield of the product prepared using the method is 18% or higher.

6. The method as described in claim 1, characterized in that, The product prepared by the method contains 5 ppm of Al and Fe, respectively.

7. The method as described in claim 1, characterized in that, The product prepared by the method contains 5 ppm or less of K and Ca.

8. The method as described in claim 1, characterized in that, The product prepared using the method contains 40 ppm or less of Na.

9. The method as described in claim 1, characterized in that, The cleaning solution also contains additives selected from the group consisting of: organic solvents containing acetone, organic bases containing NH4OH, inorganic acids containing HNO3 and HCl, or combinations thereof.

10. The method as described in claim 1, characterized in that, The weight ratio of deionized water to additives in the cleaning solution is 5:1 to 20:1.

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