Method for preparing phosphonic compound and phosphonic compound prepared thereby

Abstract

The method for manufacturing a phosphinic acid compound of the present invention may include: a primary synthesis step of producing a primary synthetic material by a primary synthesis reaction using a primary synthetic raw material; a secondary synthesis step of producing a secondary synthetic material by a secondary synthesis reaction using the primary synthetic material and a secondary synthetic raw material; and a tertiary synthesis step of producing a tertiary synthetic material by a tertiary synthesis reaction using the secondary synthetic material and a tertiary synthetic raw material. Here, the first synthetic material is bis(2-ethylhexyl) phosphite, the second synthetic material is bis(2-ethylhexyl)-2-ethylhexyl phosphonate, and the third synthetic material may be mono-2-ethylhexyl(2-ethylhexyl)phosphonate.

Description

Technology Field

[0001] The present invention relates to a method for producing a phosphinic acid compound and a phosphinic acid compound produced thereby, and more specifically, to a method for producing (2-ethylhexyl)phosphonate and (2-ethylhexyl)phosphonate produced thereby. Background Technology

[0002] Rechargeable batteries are energy storage devices used in various electronic devices, such as mobile phones, laptops, and electric vehicles. Various elements, including lithium, cobalt, nickel, and manganese, are used in rechargeable batteries. Among these, cobalt plays a crucial role in improving the capacity and energy density of rechargeable batteries.

[0003] Meanwhile, due to factors such as soaring raw material prices and the revitalization of the electric vehicle market, research on the recycling of used electric vehicle batteries is actively underway, and the market for used electric vehicle batteries is predicted to grow.

[0004] Used electric vehicle batteries contain large amounts of valuable metals essential for the composition of secondary batteries, such as nickel, cobalt, manganese, and lithium.

[0005] To recycle used secondary batteries from electric vehicles, metal materials can be separated by dissolving the crushed or ground powder of the used secondary batteries in sulfuric acid and then leaching, purifying, or solvent extraction.

[0006] In order to separate cobalt and nickel from secondary batteries using solvent extraction, a solvent capable of selectively extracting nickel or cobalt is required, and generally, a solvent that extracts cobalt is used. Such a solvent must have a high affinity for cobalt and be able to effectively dissolve cobalt ions.

[0007] For example, mono-2-ethylhexyl(2-ethylhexyl)phosphonate has a high affinity for cobalt and is used as a solvent to effectively extract cobalt from secondary batteries.

[0008] However, conventional methods for producing mono-2-ethylhexyl(2-ethylhexyl)phosphonate may result in low reaction yields because the phosphinization reaction is not easy. Additionally, the purity of mono-2-ethylhexyl(2-ethylhexyl)phosphonate may be low due to intermediate reaction byproducts. Therefore, research is needed on methods to increase the purity of mono-2-ethylhexyl(2-ethylhexyl)phosphonate and achieve high reaction yields.

[0009] The inventor of the present invention has completed the present invention after conducting long research and going through trial and error to solve these problems. The problem to be solved

[0010] The present invention was created to solve the problems of the prior art as described above, and one objective of the present invention is to provide a method for producing a phosphinic acid compound capable of producing a phosphinic acid compound having high purity and a phosphinic acid compound produced by the same.

[0011] In addition, one objective of the present invention is to provide a method for producing a phosphinic acid compound with a high reaction yield and a phosphinic acid compound produced thereby.

[0012] Meanwhile, other unspecified objects of the present invention will be further considered to the extent that they can be easily inferred from the following detailed description and effects. means of solving the problem

[0013] A method for producing a phosphinic acid compound according to one aspect of the present invention may include: a primary synthesis step of producing a primary synthetic material by a primary synthesis reaction using a primary synthetic raw material; a secondary synthesis step of producing a secondary synthetic material by a secondary synthesis reaction using the primary synthetic material and a secondary synthetic raw material; and a tertiary synthesis step of producing a tertiary synthetic material by a tertiary synthesis reaction using the secondary synthetic material and a tertiary synthetic raw material. Here, the first synthetic material is bis(2-ethylhexyl) phosphite, the second synthetic material is bis(2-ethylhexyl)-2-ethylhexyl phosphonate, and the third synthetic material may be mono-2-ethylhexyl(2-ethylhexyl)phosphonate.

[0014] In one embodiment of the present invention, the first synthesis step may include a first synthesis reaction step of introducing the first synthesis raw material into a reaction vessel to produce the first synthesis material by the first synthesis reaction; and a first post-treatment step of post-treating a solution containing the first synthesis material to obtain the first synthesis material of high purity.

[0015] In one embodiment of the present invention, the primary synthetic raw material may include phosphorous acid (H3PO3), acetic anhydride, and 2-ethylhexanol.

[0016] In one embodiment of the present invention, the first synthesis reaction step may be performed in a temperature range of 40°C to 60°C.

[0017] In one embodiment of the present invention, the first post-treatment step may include the step of obtaining only the first organic component after introducing a solution containing the first synthetic material into a separating funnel and leaving it to stand; and the step of obtaining the first synthetic material by vacuum distillation or vacuum distillation of the first organic component.

[0018] In one embodiment of the present invention, the secondary synthesis step may include a secondary synthesis reaction step of introducing the primary synthesis material and the secondary synthesis raw material into a reaction vessel to produce the secondary synthesis material by the secondary synthesis reaction; and a secondary post-treatment step of post-treating a solution containing the secondary synthesis material to obtain the secondary synthesis material of high purity.

[0019] In one embodiment of the present invention, the secondary synthetic raw material may include 3-(chloromethyl)heptane, methyl trioctyl ammonium chloride, dichloromethane, and sodium hydroxide (NaOH).

[0020] In one embodiment of the present invention, the secondary synthesis reaction step may be carried out in a temperature range of 15°C to 20°C.

[0021] In one embodiment of the present invention, the second post-treatment step may include: a step of introducing a solution containing the second synthetic material into a separatory funnel and leaving it to stand, and then obtaining only the second organic component; a step of washing the second organic component 2 to 3 times with ultrapure water, washing it 2 to 3 times with a saturated sodium chloride (NaCl) aqueous solution, and washing it again with ultrapure water; and a step of obtaining the second synthetic material by fractional distillation of the second organic component.

[0022] In one embodiment of the present invention, the tertiary synthesis step may include: a tertiary synthesis reaction step in which the tertiary synthesis material and the tertiary synthesis raw material are introduced into a reaction vessel to produce the tertiary synthesis material by the tertiary synthesis reaction; and a tertiary post-treatment step in which a solution containing the tertiary synthesis material is post-treated to obtain the tertiary synthesis material of high purity.

[0023] In one embodiment of the present invention, the tertiary synthetic raw material may include 2-ethylhexanol and sodium hydroxide (NaOH).

[0024] In one embodiment of the present invention, the third synthesis reaction step may be carried out in a temperature range of 90°C to 110°C.

[0025] In one embodiment of the present invention, the third post-treatment step may include the step of introducing a solution containing the third synthetic material into a separating funnel and leaving it to stand, after which only the third organic component is obtained; the step of washing the third organic component 2 to 3 times using ultrapure water; and the step of obtaining the third synthetic material by fractional distillation of the third organic component.

[0026] In one embodiment of the present invention, the reaction vessel may be a double-jacketed reactor connected to a chiller.

[0027] In one embodiment of the present invention, after the third post-processing step, a drying step for drying the third synthetic material may be further included.

[0028] In addition, a phosphinic acid compound according to one aspect of the present invention can be produced by the method for manufacturing a phosphinic acid compound described above. Effects of the invention

[0029] The method for producing a phosphinic acid compound according to the present invention can produce a phosphinic acid compound of high purity through a plurality of synthesis reaction processes and a plurality of post-treatment processes. In addition, the phosphinic acid compound produced accordingly can have high purity.

[0030] In addition, the method for manufacturing a phosphinic acid compound according to the present invention can achieve a high reaction yield by optimizing the synthetic raw materials and synthesis conditions. Brief explanation of the drawing

[0031] FIG. 1 is a drawing illustrating a method for preparing a phosphinic acid compound according to one embodiment of the present invention. Figure 2 is a diagram illustrating the first synthesis step shown in Figure 1. Figure 3 is a diagram illustrating the secondary synthesis step illustrated in Figure 1. Figure 4 is a diagram illustrating the third synthesis step shown in Figure 1. It should be noted that the attached drawings are provided as examples for reference to help understand the technical concept of the present invention, and the scope of the rights of the present invention is not limited by them. Specific details for implementing the invention

[0032] The terms used in this invention have been selected to be as widely used as possible; however, in specific cases, terms have been arbitrarily selected by the applicant. In such cases, the meaning should be understood by considering the specific details or usage described in the content for implementing the invention, rather than merely the name of the term.

[0033] The terms used in this application are used merely to describe specific embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, terms such as "comprising" or "having" are intended to specify the presence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0034] The objects, specific advantages, and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments. Furthermore, in describing the present invention, detailed descriptions of related prior art are omitted where it is determined that such detailed descriptions may unnecessarily obscure the essence of the invention.

[0035] Additionally, terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but said components are not limited by said terms. These terms are used solely for the purpose of distinguishing one component from another.

[0037] The method for preparing a phosphinic acid compound according to the present invention comprises a first synthesis step of synthesizing a primary synthetic material, bis(2-ethylhexyl) phosphite; a second synthesis step of synthesizing a secondary synthetic material, bis(2-ethylhexyl)-2-ethylhexyl phosphonate, using bis(2-ethylhexyl) phosphite; and a third synthesis step of synthesizing a final phosphinic acid compound and a tertiary synthetic material, mono-2-ethylhexyl(2-ethylhexyl)phosphonate, using bis(2-ethylhexyl)-2-ethylhexyl phosphonate. In addition, a phosphinic acid compound of high purity can be obtained by performing a post-processing step after the synthesis reaction in the first, second, and third synthesis steps to remove unnecessary components.

[0039] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0040] FIG. 1 is a drawing for explaining a method for manufacturing a phosphinic acid compound according to an embodiment of the present invention, FIG. 2 is a drawing for explaining a first synthesis step illustrated in FIG. 1, FIG. 3 is a drawing for explaining a second synthesis step illustrated in FIG. 1, and FIG. 4 is a drawing for explaining a third synthesis step illustrated in FIG. 1.

[0041] Referring to FIGS. 1 to 4, a method for manufacturing a phosphinic acid compound according to one embodiment of the present invention comprises a raw material preparation step (S100), a synthesis tool preparation step (S200), a first synthesis step (S300), a second synthesis step (S400), a third synthesis step (S500), and a drying step (S600), thereby enabling the production of a phosphinic acid compound of high purity.

[0042] In the raw material preparation step (S100), raw materials necessary for the synthesis of a phosphinic acid compound can be prepared. The raw materials may include primary synthesis raw materials, secondary synthesis raw materials, and tertiary synthesis raw materials.

[0043] Here, the primary synthetic raw materials may include phosphorous acid (H3PO3), acetic anhydride, and 2-ethylhexanol.

[0044] Acetic anhydride can have a molecular structure such as Chemical Formula 1 below.

[0045]

[0046] 2-ethylhexanol has the molecular formula C8H 18 It is an organic compound of O, a type of alcohol. 2-ethylhexanol is also known by other names such as isooctanol or 2-ethyl-1-octanol, and can have a molecular structure as shown in Chemical Formula 2 below.

[0047]

[0048] The secondary synthetic raw material may include bis(2-ethylhexyl) phosphite obtained in the primary synthesis step, 3-(chloromethyl)heptane, methyl trioctyl ammonium chloride, dichloromethane, and sodium hydroxide (NaOH).

[0049] 3-(chloromethyl)heptane is C8H 17 It is a compound having the molecular formula of Cl, and can have a molecular structure such as Chemical Formula 3 below.

[0050]

[0051] Methyltrioctylammonium chloride can act as an interphase transfer catalyst. This methyltrioctylammonium chloride is C 25 H 54 It is a compound having the molecular formula ClN, and can have a molecular structure such as the following chemical formula 4.

[0052]

[0053] Dichloromethane is a compound having the molecular formula CH2Cl2 and can have a molecular structure as shown in Chemical Formula 5 below.

[0054]

[0055] The tertiary synthesis raw material may include bis(2-ethylhexyl)-2-ethylhexyl phosphonate obtained in the secondary synthesis step, 2-ethylhexanol, and sodium hydroxide (NaOH).

[0057] In the synthesis tool preparation step (S200), after preparing the raw materials, a synthesis tool used for synthesizing the phosphinic acid compound can be prepared. Here, the synthesis tool may include a reaction vessel, a stirrer, and a mounting stand.

[0058] The reaction vessel can provide a space where raw materials for phosphinic acid compounds are introduced and a reaction for the synthesis of phosphinic acid compounds takes place. A double-jacketed reactor can be used as the reaction vessel. A double-jacketed reactor can control the temperature of the internal space and regulate the reaction rate. In addition, a double-jacketed reactor can carry out the reaction safely and efficiently.

[0059] When a double-jacketed reactor is used as a reaction vessel, a chiller may be connected to the vessel. The chiller can regulate the temperature inside the reaction vessel by circulating cooling water or a refrigerant.

[0060] The stirrer can stir the material introduced into the reaction vessel to mix it homogeneously.

[0061] The mounting stand supports the reaction vessel and can fix and support the reaction vessel while the reaction for the synthesis of phosphinic acid compounds proceeds.

[0063] In the first synthesis step (S300), bis(2-ethylhexyl) phosphite, which is a first synthesis material, can be synthesized using a first synthesis raw material. To this end, the first synthesis step (S300) may include a first synthesis raw material input step (S310), a first synthesis reaction step (S320), and a first post-treatment step (S330).

[0064] In the first synthesis raw material input step (S310), phosphorous acid (H3PO3) and acetic anhydride are added to a reaction vessel and stirred at room temperature to dissolve the acetic anhydride. Then, 2-ethylhexanol is added to the reaction vessel and stirred.

[0065] Here, 2-ethylhexanol can be added slowly drop by drop using a pipette, such as in a dropwise method.

[0066] In the first synthesis reaction step (S320), bis(2-ethylhexyl) phosphite is synthesized by continuing the first synthesis reaction while continuously stirring the first synthesis raw material while adding 2-ethylhexanol in a dropwise manner while maintaining the temperature inside the reaction vessel at 40°C to 60°C.

[0067] Bis(2-ethylhexyl)-phosphite can have a molecular structure such as the following chemical formula 6.

[0068]

[0069] During the primary synthesis reaction, fumes such as gases or vapors of reaction byproducts may be generated. In particular, since 2-ethylhexanol, the primary synthesis raw material, is a toxic volatile substance, the fumes may contain harmful substances. Therefore, the primary synthesis reaction step (S320) may be carried out in a place equipped with an exhaust device such as a duct.

[0070] Once the first synthesis reaction is finished, the internal temperature of the reaction vessel can be lowered to room temperature.

[0071] As the first synthesis reaction step (S320) described above is carried out, bis(2-ethylhexyl) phosphite can be synthesized. Here, bis(2-ethylhexyl) phosphite can be synthesized by reacting 2-ethylhexanol with phosphoric acid.

[0072] In the first synthesis reaction step (S320), acetic anhydride promotes the chemical reaction between 2-ethylhexanol and phosphoric acid, thereby facilitating the production of bis(2-ethylhexyl) phosphite. Additionally, acetic anhydride can reduce impurities or by-products generated during the synthesis reaction of bis(2-ethylhexyl) phosphite and remove moisture. Therefore, acetic anhydride can increase the synthesis reaction rate of bis(2-ethylhexyl) phosphite and improve the reaction yield. For example, the reaction yield in the first synthesis reaction step (S320) can be 96% or higher.

[0073] In the first post-processing step (S330), high-purity bis(2-ethylhexyl) phosphite can be obtained by removing substances other than bis(2-ethylhexyl) phosphite. For example, bis(2-ethylhexyl) phosphite with a purity of 95% or higher can be obtained.

[0074] First, the solution after the first synthesis reaction in the reaction vessel may contain bis(2-ethylhexyl) phosphite, which is the product of the first synthesis reaction, and phosphoric acid, acetic anhydride, and 2-ethylhexanol remaining after the first synthesis reaction.

[0075] Since phosphoric acid is added in the form of an aqueous solution, acetic anhydride that did not participate in the first synthesis reaction is dissolved in the aqueous phosphoric acid solution. Therefore, if the solution after the first synthesis reaction is placed into a separatory funnel and left for a certain period of time, the first organic component, including bis(2-ethylhexyl) phosphite and 2-ethylhexanol, and the phosphoric acid and acetic acid in the form of aqueous solutions can be separated into upper and lower parts. Here, only the first organic component is taken.

[0076] In the first organic component, since 2-ethylhexanol is a volatile substance, 2-ethylhexanol can be removed through reduced pressure distillation or vacuum distillation. To this end, the reaction vessel can be connected to a reduced pressure distillation apparatus or a vacuum distillation apparatus.

[0077] When 2-ethylhexanol is removed from the first organic component, high-purity bis(2-ethylhexyl) phosphite can be obtained.

[0078] As described above, in the first synthesis step (S300), bis(2-ethylhexyl) phosphite is synthesized and post-treated, thereby obtaining bis(2-ethylhexyl) phosphite of high purity, for example, 95% or higher. In addition, the reaction yield in the first synthesis reaction step (S320) is 96% or higher, so the first synthesis reaction step (S320) can exhibit a very high reaction yield.

[0080] In the second synthesis step (S400), a second synthesis material, bis(2-ethylhexyl)-2-ethylhexyl phosphonate, can be synthesized using the bis(2-ethylhexyl) phosphite obtained in the first synthesis step and the second synthesis raw material. To this end, the second synthesis step (S400) may include a second synthesis raw material input step (S410), a second synthesis reaction step (S420), and a second post-treatment step (S430).

[0081] In the second synthesis raw material input step (S410), bis(2-ethylhexyl) phosphite obtained in the first synthesis step, methyl trioctyl ammonium chloride, an aqueous solution of sodium hydroxide (NaOH), 3-(chloromethyl)heptane, and dichloromethane can be introduced into a reaction vessel and stirred. To explain this in more detail, first, bis(2-ethylhexyl) phosphite obtained in the first synthesis step is introduced into a reaction vessel. Methyl trioctyl ammonium chloride and sodium hydroxide (NaOH) are introduced into the reaction vessel containing the bis(2-ethylhexyl) phosphite and dissolved. Then, 3-(chloromethyl)heptane and dichloromethane are added and stirred.

[0082] In the second synthesis reaction step (S420), bis(2-ethylhexyl)-2-ethylhexyl phosphonate can be synthesized through the reaction of the input second synthesis raw materials. For example, after inputting the second synthesis raw materials, dichloromethane can be additionally added and stirred to proceed with the second synthesis reaction. The second synthesis reaction step (S420) can be carried out in a temperature range of 15°C to 20°C.

[0083] Bis(2-ethylhexyl)-2-ethylhexyl phosphonate can have a molecular structure as shown in Chemical Formula 7 below.

[0084]

[0085] The synthesis of bis(2-ethylhexyl)-2-ethylhexyl phosphonate is described in more detail below.

[0086] First, methyl trioctyl ammonium chloride acts as a catalyst to increase the synthesis reaction rate of bis(2-ethylhexyl)-2-ethylhexyl phosphonate, and sodium hydroxide (NaOH) can control the pH of the reaction environment.

[0087] 3-(Chloromethyl)heptane can react with bis(2-ethylhexyl) phosphite to synthesize bis(2-ethylhexyl)-2-ethylhexyl phosphonate. Here, dichloromethane can be used as a solvent to effectively mix the reactants.

[0088] Here, 3-(chloromethyl)heptane and bis(2-ethylhexyl) phosphite, which are the aqueous and organic layers, can be dissolved in dichloromethane, a solvent, together with methyltrioctylammonium chloride, an interphase transfer catalyst, in an aqueous NaOH solution, so that an exchange can occur at the interface and a reaction can occur in the organic layer. Accordingly, bis(2-ethylhexyl)-2-ethylhexyl phosphonate can be synthesized.

[0089] Meanwhile, the synthesis reaction of bis(2-ethylhexyl)-2-ethylhexyl phosphonate is carried out while stirring the material in the reaction vessel at a temperature range of 15°C to 20°C. Through such a secondary synthesis reaction, the synthesis reaction rate of bis(2-ethylhexyl)-2-ethylhexyl phosphonate can be improved and the reaction yield can be improved. For example, the reaction yield in the secondary synthesis reaction step (S420) can be 96% or higher.

[0090] When the synthesis reaction of bis(2-ethylhexyl)-2-ethylhexyl phosphonate is completed, the material in the reaction vessel can be separated into a second organic component such as bis(2-ethylhexyl)-2-ethylhexyl phosphonate, bis(2-ethylhexyl) phosphite, methyltrioctylammonium chloride, and dichloromethane, and an inorganic component such as sodium hydroxide. Accordingly, it is necessary to obtain high-purity bis(2-ethylhexyl)-2-ethylhexyl phosphonate by removing bis(2-ethylhexyl) phosphite, methyltrioctylammonium chloride, dichloromethane, and sodium hydroxide.

[0091] The second post-treatment step (S430) is performed after the second synthesis reaction step (S420) and can be performed to obtain high-purity bis(2-ethylhexyl)-2-ethylhexyl phosphonate from the material in the reaction vessel.

[0092] In the second post-processing step (S430), the solution in which the synthesis reaction of bis(2-ethylhexyl)-2-ethylhexyl phosphonate has been completed is introduced into a separating funnel and left for a certain period of time, so that the sodium hydroxide aqueous solution, which is an inorganic component, and the second organic component can be separated into the upper and lower parts of the separating funnel. Here, only the second organic component is obtained.

[0093] The obtained second organic component may be washed two or three times with ultrapure water, then washed two or three times with an aqueous solution of saturated sodium chloride (NaCl), and then washed again with ultrapure water.

[0094] Then, since the bis(2-ethylhexyl)-2-ethylhexyl phosphonate, bis(2-ethylhexyl) phosphite, methyltrioctylammonium chloride, and dichloromethane in the second organic component have different boiling points, high-purity bis(2-ethylhexyl)-2-ethylhexyl phosphonate can be obtained using fractional distillation.

[0095] As described above, in the second synthesis step (S400), bis(2-ethylhexyl)-2-ethylhexyl phosphonate is synthesized and post-treated, so that bis(2-ethylhexyl)-2-ethylhexyl phosphonate with high purity, for example, 95% or more, can be obtained. In addition, the reaction yield in the second synthesis reaction step (S420) is 96% or more, so the second synthesis reaction step (S420) can exhibit a very high reaction yield.

[0097] In the third synthesis step (S500), the third synthesis material, mono-2-ethylhexyl(2-ethylhexyl)phosphonate, can be synthesized using the bis(2-ethylhexyl)-2-ethylhexyl phosphonate obtained in the second synthesis step and the third synthesis raw material.

[0098] To this end, the third synthesis step (S500) may include a third synthesis raw material input step (S510), a third synthesis reaction step (S520), and a third post-treatment step (S530).

[0099] In the third synthesis raw material input step (S510), bis(2-ethylhexyl)-2-ethylhexyl phosphonate obtained in the second synthesis step, 2-ethylhexanol, and an aqueous solution of sodium hydroxide (NaOH) may be input into a reaction vessel. Here, bis(2-ethylhexyl)-2-ethylhexyl phosphonate may be a starting material for the synthesis of mono-2-ethylhexyl(2-ethylhexyl)phosphonate.

[0100] In the third synthesis reaction step (S520), the synthesis reaction is carried out while refluxing the bis(2-ethylhexyl)-2-ethylhexyl phosphonate, 2-ethylhexanol, and sodium hydroxide in the reaction vessel at a temperature range of 90°C to 110°C to synthesize mono-2-ethylhexyl(2-ethylhexyl)phosphonate.

[0101] Mono-2-ethylhexyl(2-ethylhexyl)phosphonate may have a molecular structure such as the following chemical formula 8.

[0102]

[0103] The ester group (-OPO-) of bis(2-ethylhexyl)-2-ethylhexyl phosphonate reacts with the hydroxyl group of 2-ethylhexanol, and one (2-ethylhexyl) group is removed, allowing mono-2-ethylhexyl(2-ethylhexyl)phosphonate to be synthesized.

[0104] When the synthesis reaction of mono-2-ethylhexyl(2-ethylhexyl)phosphonate is completed, the material in the reaction vessel may include mono-2-ethylhexyl(2-ethylhexyl)phosphonate, residual bis(2-ethylhexyl)-2-ethylhexyl phosphonate, 2-ethylhexanol, and an aqueous sodium hydroxide solution. Here, mono-2-ethylhexyl(2-ethylhexyl)phosphonate, residual bis(2-ethylhexyl)-2-ethylhexyl phosphonate, and residual 2-ethylhexanol are third organic components, and sodium hydroxide is a water-soluble component dissolved in an aqueous solution.

[0105] It is necessary to obtain high-purity mono-2-ethylhexyl(2-ethylhexyl)phosphonate by removing residual bis(2-ethylhexyl)-2-ethylhexyl phosphonate, 2-ethylhexanol, and sodium hydroxide aqueous solution from the material in the reaction vessel described above.

[0106] The third post-treatment step (S530) is performed after the third synthesis reaction step (S520) and can be performed to obtain high-purity mono-2-ethylhexyl(2-ethylhexyl)phosphonate from the material in the reaction vessel.

[0107] In the third post-processing step (S530), the solution in which the synthesis reaction of mono-2-ethylhexyl(2-ethylhexyl)phosphonate has been completed is introduced into a separating funnel and left for a certain period of time, so that the water-soluble non-organic component containing the sodium hydroxide aqueous solution and the third organic component can be separated into the upper and lower parts of the separating funnel. Here, only the third organic component is obtained.

[0108] The obtained third organic component can be washed two or three times using ultrapure water to remove impurities.

[0109] Then, since the boiling points of mono-2-ethylhexyl(2-ethylhexyl)phosphonate, bis(2-ethylhexyl)-2-ethylhexylphosphonate, and 2-ethylhexanol in the third organic component are different from each other, high-purity mono-2-ethylhexyl(2-ethylhexyl)phosphonate can be obtained using fractional distillation.

[0110] As described above, in the third synthesis step (S500), mono-2-ethylhexyl(2-ethylhexyl)phosphonate is synthesized and post-treated, so that mono-2-ethylhexyl(2-ethylhexyl)phosphonate with high purity, for example, 96% or more, can be obtained.

[0112] In the drying step (S600), the mono-2-ethylhexyl(2-ethylhexyl)phosphonate obtained in the third synthesis step (S500) can be dried.

[0113] The mono-2-ethylhexyl(2-ethylhexyl)phosphonate obtained in the third synthesis step (S500) has high purity but may contain some impurities such as 2-ethylhexanol. 2-ethylhexanol is volatile.

[0114] Accordingly, the mono-2-ethylhexyl(2-ethylhexyl)phosphonate obtained in the third synthesis step (S500) is introduced into a drying vessel, and the mono-2-ethylhexyl(2-ethylhexyl)phosphonate is dried using a drying heating device such as an oven, and impurities such as 2-ethylhexanol can be removed at the same time. As a result, mono-2-ethylhexyl(2-ethylhexyl)phosphonate of very high purity can be obtained.

[0116] As described above, a method for producing a phosphinic acid compound according to one embodiment of the present invention can improve the reaction yield of mono-2-ethylhexyl(2-ethylhexyl)phosphonate through a plurality of synthesis reaction steps and a plurality of post-treatment processes. In addition, by removing intermediate reaction by-products and impurities through a plurality of post-treatment processes, mono-2-ethylhexyl(2-ethylhexyl)phosphonate having high purity, for example, 98 wt% or higher, can be obtained.

[0118] In the following description, an embodiment of the present invention is to be easily implemented by those skilled in the art. Furthermore, in describing the present invention, if it is determined that a detailed description of related known functions or known configurations might unnecessarily obscure the essence of the invention, such detailed description will be omitted. Also, some features shown in the drawings have been enlarged, reduced, or simplified for ease of explanation, and the drawings and their components are not necessarily depicted in appropriate proportions. However, those skilled in the art will easily understand these details.

[0120] [Example]

[0121] Example 1.

[0122] Prepare the raw materials. First, as the primary raw material for synthesis, phosphoric acid (H3PO4) is used. 3, Prepare acetic anhydride (CAS.13598-36-2), acetic anhydride (CAS.108-24-7)), and 2-ethylhexanol (CAS.104-76-7).

[0123] Then, as secondary synthetic raw materials, 3-(chloromethyl)heptane (CAS. 123-04-6), methyl trioctyl ammonium chloride (CAS. 5137-55-3), dichloromethane (CAS. 1975-09-02), and sodium hydroxide (NaOH) are prepared. Here, sodium hydroxide is prepared as a 50 wt% aqueous solution.

[0124] Then, 2-ethylhexanol (CAS. 104-76-7) and sodium hydroxide (NaOH) are prepared as tertiary synthetic raw materials. Here, sodium hydroxide is prepared as a 50 wt% aqueous solution.

[0125] After preparing the raw materials, 100g of phosphoric acid and 311g of acetic anhydride from the primary raw materials are added to a reaction vessel and dissolved by stirring at room temperature. Here, a double-jacketed reactor with an internal space of 2L is used as the reaction vessel, and a chiller is attached to the double-jacketed reactor so that the temperature of the double-jacketed reactor can be controlled.

[0126] When acetic anhydride is dissolved in phosphoric acid, the reaction vessel is heated to 50°C using a chiller and maintained at that temperature.

[0127] Then, bis(2-ethylhexyl) phosphite is synthesized by carrying out a first synthesis reaction by adding 349 g of 2-ethylhexanol dropwise while stirring for 2 hours. Here, the reaction yield of the first synthesis reaction is 96%.

[0128] When the first synthesis reaction is completed, the solution in the reaction vessel is subjected to a first post-treatment to obtain bis(2-ethylhexyl) phosphite with a purity of 95% or higher.

[0129] To explain this in more detail, the solution in which bis(2-ethylhexyl) phosphite was synthesized is subjected to vacuum distillation to remove 2-ethylhexanol. Then, the solution in which bis(2-ethylhexyl) phosphite was synthesized is placed in a separatory funnel and left to stand, after which only bis(2-ethylhexyl) phosphite is obtained, and the remaining components are discarded or recovered separately. Here, the purity of the obtained bis(2-ethylhexyl) phosphite is 99%.

[0130] After obtaining bis(2-ethylhexyl) phosphite, 9.84 g of methyl trioctyl ammonium chloride and 390 g of sodium hydroxide, which are secondary synthesis raw materials, are added to a reaction vessel and mixed. Here, a 2 L capacity double-jacketed reactor equipped with a chiller is used as the reaction vessel, and the sodium hydroxide is a 50 wt% aqueous solution. Then, under room temperature conditions, 199 g of 3-(chloromethyl)heptane and 120 g of dichloromethane are added to the reaction vessel and stirred for 10 minutes.

[0131] 373g of bis(2-ethylhexyl) phosphite is mixed with 280g of dichloromethane, and the mixture of bis(2-ethylhexyl) phosphite and dichloromethane is placed in a reaction vessel and stirred for 5 hours to carry out a secondary synthesis reaction.

[0132] Here, the secondary synthesis reaction is carried out at 18°C, and bis(2-ethylhexyl)-2-ethylhexyl phosphonate is synthesized by the secondary synthesis reaction. In addition, the reaction yield of the secondary synthesis reaction is 96%.

[0133] When the second synthesis reaction is completed, the solution in the reaction vessel is subjected to a second post-treatment to obtain bis(2-ethylhexyl)-2-ethylhexyl phosphonate with a purity of 95% or higher.

[0134] To explain this in more detail, if a solution in which bis(2-ethylhexyl)-2-ethylhexyl phosphonate has been synthesized is introduced into a separatory funnel and left for a certain period of time, the non-organic component, an aqueous sodium hydroxide solution, and the organic component can be separated into the upper and lower parts of the separatory funnel. Here, only the organic component is obtained.

[0135] After washing the obtained organic components with ultrapure water, only the organic components are obtained using a separatory funnel. This washing with ultrapure water is repeated three times.

[0136] Then, the organic components are washed with a saturated sodium chloride (NaCl) aqueous solution, and only the organic components are obtained using a separatory funnel. This washing with a saturated sodium chloride (NaCl) aqueous solution is repeated three times.

[0137] After washing the organic components again with ultrapure water, only the organic components are obtained using a separatory funnel.

[0138] Then, since the boiling points of the substances within the organic components—bis(2-ethylhexyl)-2-ethylhexyl phosphonate, bis(2-ethylhexyl) phosphite, methyltrioctylammonium chloride, and dichloromethane—are different from each other, high-purity bis(2-ethylhexyl)-2-ethylhexyl phosphonate can be obtained using fractional distillation. Here, the purity of the obtained bis(2-ethylhexyl)-2-ethylhexyl phosphonate is 99%. Components other than bis(2-ethylhexyl)-2-ethylhexyl phosphonate are disposed of or recovered separately.

[0139] After obtaining bis(2-ethylhexyl)-2-ethylhexyl phosphonate, 400g of bis(2-ethylhexyl)-2-ethylhexyl phosphonate is added to a reaction vessel, and 200g of 2-ethylhexanol and 100g of sodium hydroxide, which are raw materials for tertiary synthesis, are added. Here, a 2L capacity double-jacketed reactor combined with a chiller is used as the reaction vessel, and the sodium hydroxide is a 50wt% aqueous solution.

[0140] Then, the material in the reaction vessel is refluxed and the tertiary synthesis reaction is carried out for 40 hours. Here, the tertiary synthesis reaction is carried out at 100°C, and mono-2-ethylhexyl(2-ethylhexyl)phosphonate is synthesized by the tertiary synthesis reaction.

[0141] When the third synthesis reaction is completed, the solution in the reaction vessel is subjected to a third post-treatment to obtain mono-2-ethylhexyl(2-ethylhexyl)phosphonate with a purity of 95% or higher.

[0142] To explain this in more detail, if a solution in which mono-2-ethylhexyl(2-ethylhexyl)phosphonate has been synthesized is introduced into a separatory funnel and left for a certain period of time, the inorganic component, an aqueous sodium hydroxide solution, and the organic component can be separated into the upper and lower parts of the separatory funnel. From this, only the organic component is obtained.

[0143] After washing the obtained organic components with ultrapure water, only the organic components are obtained using a separatory funnel. This washing with ultrapure water is repeated three times.

[0144] After washing the organic components with ultrapure water, only the organic components are obtained using a separatory funnel.

[0145] Then, since the boiling points of mono-2-ethylhexyl(2-ethylhexyl)phosphonate, residual bis-2-ethylhexyl(2-ethylhexyl)phosphonate, and 2-ethylhexanol, which are substances within the organic components, are different from each other, high-purity mono-2-ethylhexyl(2-ethylhexyl)phosphonate can be obtained using fractional distillation. Here, the purity of the obtained mono-2-ethylhexyl(2-ethylhexyl)phosphonate is 99%. Components other than mono-2-ethylhexyl(2-ethylhexyl)phosphonate are disposed of or recovered separately.

[0146] The obtained mono-2-ethylhexyl(2-ethylhexyl)phosphonate was transferred to a drying container. A beaker with an internal capacity of 1 L was used as the drying container.

[0147] A drying container containing mono-2-ethylhexyl(2-ethylhexyl)phosphonate was placed in an oven and dried at 80°C for 3 hours to evaporate substances other than mono-2-ethylhexyl(2-ethylhexyl)phosphonate, particularly residual bis-2-ethylhexyl(2-ethylhexyl)phosphonate and 2-ethylhexanol or impurities.

[0148] Mono-2-ethylhexyl(2-ethylhexyl)phosphonate with a purity of 99% was produced through the process described above.

[0150] The present invention is not limited to the embodiments described above, and it is obvious that new embodiments may include a combination of at least two of the above embodiments or a combination of at least one of the above embodiments and known technology.

[0151] Although the present invention has been described in detail through specific embodiments, this is for the purpose of specifically explaining the invention, and the invention is not limited thereto. It will be apparent that modifications or improvements can be made by those skilled in the art within the technical scope of the invention.

[0152] All simple variations or modifications of the present invention fall within the scope of the present invention, and the specific scope of protection of the present invention will be clarified by the appended claims. Explanation of the symbols

[0153] S100: Raw material preparation step S200: Compositing Tool Preparation Step S300: 1st synthesis step S310: 1st synthetic raw material input step S320: 1st synthesis reaction step S330: 1st post-processing step S400: Secondary synthesis step S410: Secondary synthesis raw material input step S420: Secondary synthesis reaction step S430: Secondary post-processing step S500: 3rd synthesis step S510: 3rd synthesis raw material input step S520: Third synthesis reaction step S530: 3rd post-processing step S600: Drying stage

Claims

Claim 1 A primary synthesis step of producing a primary synthetic material by a primary synthesis reaction using a primary synthetic raw material; a secondary synthesis step of producing a secondary synthetic material by a secondary synthesis reaction using the primary synthetic material and a secondary synthetic raw material; and includes a tertiary synthesis step for producing a tertiary synthetic material by a tertiary synthesis reaction using the secondary synthetic material and the tertiary synthetic raw material, wherein the primary synthetic material is bis(2-ethylhexyl) phosphite, the secondary synthetic material is bis(2-ethylhexyl)-2-ethylhexyl phosphonate, and the tertiary synthetic material is mono-2-ethylhexyl(2-ethylhexyl)phosphonate, and the primary synthesis step is a primary synthesis reaction step for producing the primary synthetic material by introducing the primary synthetic raw material into a reaction vessel and performing the primary synthesis reaction; A method for preparing a phosphinic acid compound comprising a first post-treatment step of obtaining a high-purity first synthetic material by post-treating a solution containing the first synthetic material, wherein the first synthetic raw material comprises phosphorous acid (H3PO3), acetic anhydride, and 2-ethylhexanol. Claim 2 delete Claim 3 delete Claim 4 A method for preparing a phosphinic acid compound according to claim 1, wherein the first synthesis reaction step is performed in a temperature range of 40°C to 60°C. Claim 5 A method for producing a phosphinic acid compound according to claim 4, wherein the first post-treatment step comprises the step of introducing a solution containing the first synthetic material into a separating funnel and leaving it to stand, thereby obtaining only the first organic component; and the step of obtaining the first synthetic material by vacuum distillation or reduced pressure distillation of the first organic component. Claim 6 A method for manufacturing a phosphinic acid compound according to claim 1, wherein the secondary synthesis step comprises: a secondary synthesis reaction step in which the primary synthesis material and the secondary synthesis raw material are introduced into a reaction vessel to produce the secondary synthesis material by the secondary synthesis reaction; and a secondary post-treatment step in which a solution containing the secondary synthesis material is post-treated to obtain the secondary synthesis material of high purity. Claim 7 A method for preparing a phosphinic acid compound according to claim 6, wherein the secondary synthetic raw materials include 3-(chloromethyl)heptane, methyl trioctyl ammonium chloride, dichloromethane, and sodium hydroxide (NaOH). Claim 8 A method for preparing a phosphinic acid compound according to claim 7, wherein the secondary synthesis reaction step is carried out in a temperature range of 15°C to 20°C. Claim 9 A method for producing a phosphinic acid compound according to claim 8, wherein the second post-treatment step comprises: a step of introducing a solution containing the second synthetic material into a separatory funnel and leaving it to stand, thereby obtaining only the second organic component; a step of washing the second organic component 2 to 3 times with ultrapure water, then washing it 2 to 3 times with a saturated sodium chloride (NaCl) aqueous solution, and then washing it again with ultrapure water; and a step of obtaining the second synthetic material by fractional distillation of the second organic component. Claim 10 A method for manufacturing a phosphinic acid compound according to claim 6, wherein the tertiary synthesis step comprises: a tertiary synthesis reaction step in which the tertiary synthesis material and the tertiary synthesis raw material are introduced into a reaction vessel to produce the tertiary synthesis material by the tertiary synthesis reaction; and a tertiary post-treatment step in which a solution containing the tertiary synthesis material is post-treated to obtain the tertiary synthesis material of high purity. Claim 11 In claim 10, the method for preparing a phosphinic acid compound comprising 2-ethylhexanol and sodium hydroxide (NaOH) as the tertiary synthetic raw material. Claim 12 A method for producing a phosphinic acid compound according to claim 11, wherein the third synthesis reaction step is carried out in a temperature range of 90°C to 110°C. Claim 13 A method for producing a phosphinic acid compound according to claim 12, wherein the third post-treatment step comprises: a step of introducing a solution containing the third synthetic material into a separatory funnel and leaving it to stand, after which only the third organic component is obtained; a step of washing the third organic component 2 to 3 times using ultrapure water; and a step of obtaining the third synthetic material by fractional distillation of the third organic component. Claim 14 A method for producing a phosphinic acid compound according to claim 10, wherein the reaction vessel is a double-jacketed reactor connected to a chiller. Claim 15 A method for manufacturing a phosphinic acid compound according to claim 10, further comprising a drying step for drying the tertiary synthetic material after the tertiary post-treatment step. Claim 16 A phosphinic acid compound prepared by the method for preparing a phosphinic acid compound of any one of claims 1, and 4 to 15.

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