Method for producing ether bond-containing compound

Abstract

To provide a method for producing an ether bond-containing compound in which a residual amount of alcohol is sufficiently suppressed and which has more excellent color tone than when produced by a conventional method.SOLUTION: Provided is a method for producing an ether bond-containing compound represented by a predetermined structure. The method for producing an ether bond-containing compound comprises: a step of reacting an epoxy group-containing compound represented by a predetermined structure and an alcohol represented by a predetermined structure; a first purification step of removing the alcohol contained in a reaction solution after the reaction step; and a second purification step of removing the alcohol from a reaction solution after the first purification step by performing distillation while introducing a gas including an inert gas, where a total amount of oxygen introduced in a reaction solution in the second purification step is 0.20 mole or less relative to 100 moles of the epoxy group-containing compound charged in the reaction step.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing an ether bond-containing compound, and more particularly to a method for producing an ether bond-containing compound that can be suitably used as a raw material for polymers useful in water treatment agents, dispersants, detergents, and cleaning agents. [Background technology]

[0002] Compounds having an ether bond in their structure are known to have a variety of structures and are used for a variety of applications. In recent years, it has been discovered that polymers obtained from compositions containing compounds with specific structures having an ethylenically unsaturated group and an ether bond are useful as water treatment agents and scale inhibitors (see Patent Document 1). Patent Document 2 also discloses a method for producing an ether bond-containing compound represented by a predetermined structure, the method comprising: a step of reacting an epoxy group-containing compound represented by a predetermined structure with an alcohol represented by a predetermined structure; a first purification step of removing the alcohol contained in the reaction solution after the reaction step; and a second purification step of removing the alcohol from the reaction solution after the first purification step by distillation while introducing an inert gas, wherein the flow rate of the inert gas introduced in the second purification step is 2.0 to 4.5 mol % per hour with respect to the number of moles of the epoxy group-containing compound charged in the reaction step. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-62176 [Patent Document 2] Japanese Patent Application Publication No. 2017-214324 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned Patent Documents 1 and 2, a method for producing an ether bond-containing compound having the above-mentioned specific structure is used in which allyl glycidyl ether and butanol are reacted under conditions in which butanol is in excess, and then the butanol is removed from the reaction solution. To remove butanol from the reaction solution, vacuum distillation is performed, followed by further distillation with the introduction of nitrogen gas. This is because as the butanol removal progresses, it becomes more difficult for the butanol to boil, making removal more difficult. By introducing nitrogen gas, the pressure in the system increases even when the butanol partial pressure is low, thereby promoting butanol removal. Since a long butanol removal process can result in coloration of the reaction product, it is preferable to remove butanol as quickly as possible. To achieve this, it is preferable to introduce a large amount of inert gas, such as nitrogen gas. Ether bond-containing compounds are used in applications such as detergents and cleaning agents in addition to water treatment agents and scale inhibitors. In particular, since high-performance detergents and cleaning agents contain large amounts of ether bond-containing compounds, the ether bond-containing compounds used as raw materials for these applications are required to have a high level of excellent color tone. Furthermore, since insufficient removal of alcohol can cause odor, it is desirable to reduce the amount of remaining alcohol as much as possible. Therefore, the above-mentioned conventional manufacturing methods are not sufficient, and there is room for improvement.

[0005] The present invention has been made in view of the above-mentioned current situation, and an object of the present invention is to provide a method for producing an ether bond-containing compound in which the amount of residual alcohol is sufficiently suppressed and the color tone is superior to that when produced by conventional methods. [Means for solving the problem]

[0006] The present inventors have investigated various methods for producing ether bond-containing compounds with better color than conventional methods. The present inventors have found that an ether bond-containing compound can be produced by a method that includes a reaction step in which an epoxy group-containing compound having a predetermined structure is reacted with an alcohol to produce the ether bond-containing compound, a first purification step in which the alcohol is removed from the reaction solution, and a second purification step in which the alcohol is removed by distillation while introducing a gas containing an inert gas. The present inventors have found that if the total amount of oxygen introduced into the reaction solution in the second purification step is 0.20 moles or less per 100 moles of the epoxy group-containing compound charged in the reaction step, the amount of residual alcohol is sufficiently reduced and an ether bond-containing compound free from coloration can be produced. Since organic compounds are generally thought to become colored due to oxidation, it is common to introduce an inert gas to suppress this. However, the present inventors have found that the ether bond-containing compound having a specific structure obtained by the above reaction step is more susceptible to coloration due to oxygen than other organic compounds, and that simply introducing a gas containing an inert gas into the second purification step results in coloration due to the influence of oxygen mixed into the reaction system. Specifically, the inventors have found that coloration is caused by the concentration of oxygen contained in the inert gas introduced into the reaction solution; for example, the oxygen concentration of industrial nitrogen gas varies from 0.1 ppm to several percent depending on the production method, and that this difference in oxygen concentration significantly affects the progress of coloration of the ether bond-containing compound. The inventors have found that an ether bond-containing compound without coloration can be produced by setting the total amount of oxygen introduced into the reaction solution in the second purification step within the above range, and have conceived that the above problem can be successfully solved, thereby arriving at the present invention.

[0007] That is, the present invention provides a compound represented by the following general formula (1):

[0008] [ka]

[0009] (In general formula (1), R 1represents a direct bond, a methylene group, or an ethylene group. 2 represents a hydrogen atom or a methyl group; and X represents an alkyl group having 1 to 6 carbon atoms. The above production method involves reacting a compound represented by the following general formula (2):

[0010] [ka]

[0011] (In general formula (2), R 1 , R 2 is the same as in general formula (1).) and an epoxy group-containing compound represented by the following general formula (3); X-OH (3) (in general formula (3), X is the same as in general formula (1)), a first purification step of removing the alcohol represented by general formula (3) contained in the reaction solution after the reaction step, and a second purification step of removing the alcohol represented by general formula (3) from the reaction solution after the first purification step by distillation while introducing a gas containing an inert gas, wherein the total amount of oxygen introduced into the reaction solution in the second purification step is 0.20 mol or less relative to 100 mol of the epoxy group-containing compound charged in the reaction step.

[0012] The oxygen concentration in the inert gas used in the second purification step is preferably 0.0001 to 3.0% by volume.

[0013] The time for carrying out the second purification step is preferably 60 to 540 minutes. In the second purification step, the temperature of the reaction solution is preferably 40 to 200°C.

[0014] The flow rate of the gas containing the inert gas introduced into the second purification step is determined by the following general formula (2): [ka]

[0015] (In general formula (2), R 1 represents a direct bond, a methylene group, or an ethylene group. 2 represents a hydrogen atom or a methyl group. The reaction rate is preferably 1.0 to 10.0 mol % per hour relative to 100 mol % of the charge amount of the epoxy group-containing compound represented by the formula (I) in the reaction step. [Effects of the Invention]

[0016] The method for producing an ether bond-containing compound of the present invention has the above-mentioned configuration, and can sufficiently suppress the amount of residual alcohol and produce an ether bond-containing compound having a color tone superior to conventional compounds. Therefore, the obtained ether bond-containing compound can be suitably used in applications such as water treatment agents, detergents, and cleaning agents. DETAILED DESCRIPTION OF THE INVENTION

[0017] Preferred embodiments of the present invention will be specifically described below, but the present invention is not limited to the following description and can be appropriately modified and applied within the scope of the present invention. Note that combinations of two or more of the individual preferred embodiments of the present invention described below also fall within the scope of preferred embodiments of the present invention.

[0018] The method for producing an ether bond-containing compound of the present invention includes a step of reacting an epoxy group-containing compound represented by general formula (2) with an alcohol represented by general formula (3), a first purification step of removing the alcohol represented by general formula (3) contained in the reaction solution after the reaction step, and a second purification step of removing the alcohol represented by general formula (3) from the reaction solution after the first purification step by distillation while introducing a gas containing an inert gas. Furthermore, the method may further include other steps that are carried out in conventional production methods, as long as they do not impair the effects of the present invention. By producing an ether bond-containing compound using this method, it is possible to produce an ether bond-containing compound that is free of color. In the present invention, the absence of coloration in the ether bond-containing compound means that the Hazen color number (APHA) value is 200 or less in the evaluation by a spectrophotometer using a sample prepared by diluting the ether bond-containing compound 20 times with methanol, as performed in the examples.

[0019] The method for producing an ether bond-containing compound of the present invention is characterized by the purification step, and therefore, the purification step will be described first, and then the reaction step will be described below. <First refining step> In the first purification step in the method for producing an ether bond-containing compound of the present invention, the method for removing the alcohol represented by general formula (3) contained in the reaction solution obtained in the reaction step is not particularly limited as long as the alcohol is removed, but it is preferable to perform the first purification step by distilling the reaction solution while boiling it. The first purification step is preferably carried out under a reduced pressure atmosphere of 12.0 kPa or less. By carrying out the first purification step under a reduced pressure atmosphere, the alcohol can be removed more efficiently, the amount of alcohol to be removed in the second purification step can be reduced, and the second purification step can be completed in a shorter time, which is preferable in terms of suppressing coloration of the ether bond-containing compound and reducing the amount of inert gas used. When the first purification step is carried out under a reduced pressure, the pressure is preferably 10.0 kPa or less, and even more preferably 7.0 kPa or less. In consideration of ease of implementation and the burden on the apparatus, the pressure is preferably 2.0 kPa or more. The first purification step in the present invention is usually started after the reaction step is completed, but may be started before the reaction step is completed.

[0020] The first purification step is preferably carried out at a temperature of the reaction solution of 30 to 200°C. By carrying out the step at such a temperature, the reaction solution boils, allowing the alcohol to be removed by distillation more efficiently and also suppressing side reactions. The temperature of the reaction solution is more preferably 30 to 150°C, and even more preferably 30 to 110°C.

[0021] Although the time for performing the first purification step is not particularly limited, in order to perform the entire purification step, including the first and second purification steps, in a short time, it is preferable to terminate the first purification step when the concentration of the alcohol represented by general formula (3) in the reaction solution during the first purification step reaches 8.0% by mass or less. More preferably, the first purification step is terminated when the alcohol represented by general formula (3) used in the reaction step reaches 6.0% by mass or less, and even more preferably when it reaches 5.0% by mass or less. Furthermore, when the first purification step is carried out while heating the reaction solution so that the temperature of the reaction solution reaches the above-mentioned range of 30 to 200°C, the temperature of the reaction solution will rise as the removal of the alcohol represented by general formula (3) progresses, and therefore it is also possible to determine the end point of the first purification step based on the temperature of the reaction solution.

[0022] <Second refining step> The second purification step is a step of removing the alcohol represented by the general formula (3) from the reaction solution after the first purification step by distillation while introducing a gas containing an inert gas, and the total amount of oxygen introduced into the reaction solution is 0.20 mol or less relative to 100 mol of the epoxy group-containing compound represented by the general formula (2) charged in the reaction step. This sufficiently suppresses the effect of oxygen on the ether bond-containing compound obtained in the reaction step, thereby sufficiently suppressing coloration. The total amount of oxygen introduced into the reaction solution is the amount of oxygen supplied to the reaction solution from the start to the end of the introduction of the gas containing the inert gas in the second purification step, and can be measured by the method described in the Examples. It is preferably 0.15 mol or less, more preferably 0.1 mol or less, and even more preferably 0.01 mol or less. The method for adjusting the total amount of oxygen introduced into the reaction solution within the above range is not particularly limited, but the amount of oxygen can be more sufficiently reduced by, for example, setting the time of the second purification step described below, the flow rate of the gas containing an inert gas, the oxygen concentration in the gas containing an inert gas, etc. within suitable ranges. In addition, the amount of oxygen introduced into the reaction solution can be more sufficiently suppressed by preventing air leakage from joints of piping, etc.

[0023] The time for carrying out the second purification step is preferably 20 to 540 minutes. This allows the alcohol represented by general formula (3) to be sufficiently removed and the coloration of the ether compound-containing compound to be more sufficiently suppressed. The time is more preferably 30 to 450 minutes, and even more preferably 50 to 360 minutes. In addition, in order to reduce the odor of the ether bond-containing compound produced, the second purification step is preferably carried out until the alcohol concentration in the reaction solution becomes 1% by mass or less of the total reaction solution. Therefore, it is preferable to appropriately adjust the time for carrying out the purification step depending on the amount of gas containing an inert gas introduced in the second purification step.

[0024] In the second purification step, the alcohol may be removed by distillation while boiling the reaction solution. However, a more preferred method involves distilling off the alcohol while introducing an inert gas at a temperature that does not cause boiling, and the temperature of the reaction solution is preferably 40 to 200°C. This allows for more efficient removal of the alcohol represented by general formula (3) and more sufficient suppression of coloration of the ether compound-containing compound. The temperature is more preferably 60 to 150°C, and even more preferably 80 to 120°C.

[0025] The flow rate of the gas containing the inert gas introduced into the second purification step is determined by the following general formula (2): [ka]

[0026] (In general formula (2), R 1represents a direct bond, a methylene group, or an ethylene group. 2 represents a hydrogen atom or a methyl group. The reaction rate is preferably 1.0 to 15.0 mol% per hour relative to 100 mol% of the charge amount of the epoxy group-containing compound represented by the general formula (3) in the reaction step. This allows for sufficient removal of the alcohol represented by the general formula (3) and more adequately suppressing coloration of the ether compound-containing compound. As will be described later, the second purification step is preferably performed by vacuum distillation. However, if the flow rate of the gas containing an inert gas is 15.0 mol% per hour or less, it is advantageous in that a reduced pressure state can be achieved without using a high-power vacuum pump. The rate is more preferably 2.0 to 14.0 mol% per hour, even more preferably 3.0 to 13.0 mol% per hour, even more preferably 4.0 to 12.0 mol% per hour, and particularly preferably 4.6 to 11.0 mol% per hour.

[0027] In the second purification step, the oxygen concentration in the gas containing the inert gas is preferably 0.0001 to 3.0% by volume. This allows for a more sufficient reduction in the total amount of oxygen introduced into the reaction solution. It is more preferably 0.0001 to 1.0% by volume, even more preferably 0.0001 to 0.5% by volume, and particularly preferably 0.0001 to 0.1%. When the oxygen concentration is 1.0% by volume or less, coloration can be more sufficiently suppressed while the alcohol represented by general formula (3) can be more sufficiently removed. Furthermore, when the oxygen concentration is 0.0001% by volume or more, the cost of the inert gas can be reduced, leading to a reduction in the production cost of the ether compound-containing compound.

[0028] The inert gas used in the second purification step is not particularly limited, and any gas generally known as an inert gas, such as helium, nitrogen, or argon, may be used, but nitrogen is preferably used because it is inexpensive. One or more of these gases may be used.

[0029] The second purification step may be carried out by distillation while introducing an inert gas, but distillation under reduced pressure is preferred in order to thoroughly remove the alcohol represented by general formula (3). When distilling off under reduced pressure, the pressure (atmospheric pressure) in the system is preferably reduced to 2.0 to 10.0 kPa, more preferably 4.0 to 8.0 kPa, and even more preferably 5.0 to 7.0 kPa.

[0030] <Reaction process> The reaction step in the method for producing an ether bond-containing compound of the present invention is a reaction reaction represented by the following general formula (2):

[0031] [ka]

[0032] (In general formula (2), R 1 , R 2 is the same as in general formula (1).) and an epoxy group-containing compound represented by the following general formula (3); X-OH (3) (wherein X is the same as in general formula (1))

[0033] Examples of the epoxy group-containing compound represented by the general formula (2) include vinyl glycidyl ether, isopropenyl glycidyl ether, (meth)allyl glycidyl ether, 3-butenyl glycidyl ether, and 3-methyl-3-butenyl glycidyl ether, and one or more of these can be used. Among these, R in the above general formula (2) 1 is a methylene group, and R 2 is a hydrogen atom, i.e., allyl glycidyl ether.

[0034] Examples of the alcohol represented by the general formula (3) include methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, tert-butyl alcohol, cyclobutanol, n-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl-2-butanol, cyclopentanol, n-hexanol, 2-hexanol, 3-hexanol, 2-methyl-1-pentanol, 3-methyl-1-pentanol, 2-ethyl-1-butanol, 2-methylcyclopentanol, and cyclohexanol, and one or more of these can be used.

[0035] In the above general formula (3), X represents an alkyl group having 1 to 6 carbon atoms. When an alcohol having such a carbon number is used, the resulting ether bond-containing compound has good polymerizability and is a suitable compound as a raw material for polymers. X in general formula (3) is preferably an alkyl group having 2 to 5 carbon atoms. More preferably, it is an alkyl group having 3 or 4 carbon atoms.

[0036] The alcohol represented by general formula (3) used in the reaction step preferably has a water content (mass of water relative to the total mass of alcohol and water) of 0 to 12 mass% when added to a reaction vessel. By using an alcohol with such a water content, the progress of a side reaction in which the epoxy group-containing compound represented by general formula (2) reacts with water can be sufficiently suppressed. The water content of the alcohol represented by general formula (3) is preferably 0 to 10 mass%, more preferably 0 to 5 mass%. When the alcohol represented by the general formula (3) contains water, the water is removed together with the alcohol represented by the general formula (3) in the first purification step and the second purification step.

[0037] In the above reaction step, it is preferable to carry out the reaction using 5 to 20 moles of the alcohol represented by general formula (3) per mole of the epoxy group-containing compound represented by general formula (2). By carrying out the reaction under conditions in which the alcohol represented by general formula (3) is in large excess, it is possible to suppress side reactions between the reaction products, the ether bond-containing compound represented by general formula (1) and the epoxy group-containing compound represented by general formula (2). Furthermore, if the amount of alcohol is up to about 20 times the amount of the epoxy group-containing compound, it can be removed without taking too much time in the purification step, and coloration of the product can be more sufficiently suppressed. The amount of the alcohol represented by general formula (3) used in the reaction step is preferably 7 to 15 moles, more preferably 8 to 12 moles, per mole of the epoxy group-containing compound represented by general formula (2).

[0038] In the above reaction step, the method of adding the epoxy group-containing compound represented by general formula (2) and the alcohol represented by general formula (3) to a reaction vessel is not particularly limited, and they may be added all at once, or one or both may be added sequentially. Preferably, the alcohol represented by general formula (3) is charged into a reaction vessel, and the epoxy group-containing compound represented by general formula (2) is added sequentially thereto while the reaction is carried out. In this way, the progression of a side reaction between the reaction product, the ether bond-containing compound represented by general formula (1) and the epoxy group-containing compound represented by general formula (2), can be sufficiently suppressed. When the epoxy group-containing compound represented by general formula (2) is added successively, the time for successive addition may be adjusted appropriately depending on the amounts of raw materials, etc., but it is preferable to add the compound successively over a period of 60 to 240 minutes, and more preferably over a period of 90 to 210 minutes.

[0039] The reaction temperature in the above reaction step is not particularly limited as long as the reaction proceeds, but is preferably 30 to 100°C, more preferably 35 to 90°C, and even more preferably 40 to 80°C. The reaction step may be carried out under any of atmospheric pressure, reduced pressure, and increased pressure.

[0040] The reaction step may be carried out using a catalyst, such as an alkali metal hydroxide, e.g., sodium hydroxide or potassium hydroxide, or an alkaline compound, e.g., an alkaline ion exchange resin, and the like. One or more of these may be used. When a catalyst is used, the amount used is preferably an amount such that the molar ratio of the epoxy group-containing compound represented by general formula (2) used in the reaction to the catalyst (epoxy group-containing compound / catalyst) is 15 / 1 to 1 / 15, more preferably an amount such that the molar ratio is 10 / 1 to 1 / 10, and even more preferably an amount such that the molar ratio is 5 / 1 to 1 / 5.

[0041] <Other processes> The method for producing an ether bond-containing compound of the present invention may include other steps as long as it includes the step of reacting the epoxy group-containing compound represented by the above general formula (2) with the alcohol represented by the general formula (3), the first purification step, and the second purification step. Other steps include a step of removing water from the alcohol represented by general formula (3) before the reaction step so that the water content in the alcohol represented by general formula (3) falls within the above-mentioned preferred range, and a step of recovering the alcohol removed in the first purification step and the second purification step and removing water from it. Methods for removing water from the alcohol in these steps include distillation, membrane separation, etc.

[0042] In the method for producing an ether bond-containing compound of the present invention, the alcohol removed in the first purification step and the second purification step may be recovered, and after removing water, the alcohol may be reused in the reaction step, which is preferred from the viewpoint of effective utilization of the alcohol. More preferably, the proportion of the recycled alcohol relative to 100% by mass of the alcohol represented by general formula (3) used in the reaction step is 50% by mass or more and 90% by mass or less, even more preferably 75% by mass or more and 90% by mass or less, and particularly preferably 80% by mass or more and 90% by mass or less. [Example]

[0043] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "parts" means "parts by mass" and "%" means "% by mass."

[0044] <Measurement of the amount of oxygen introduced into the reaction solution in the second purification step> In the present invention, the amount of oxygen introduced into the reaction solution in the second purification step was measured using the following apparatus. Device name: Toray Industries, Inc. OXYGEN ANALYZER LC-850

[0045] In the present invention, the degree of coloration of the ether bond-containing compound was evaluated by the following method. Device name: Nippon Denshoku Industries Co., Ltd. TZ6000 Sample preparation method: Dilute 20 times with methanol

[0046] Example 1 A 1 L four-neck flask equipped with a thermometer and a reflux condenser was charged with 684.2 g of industrial butanol (hereinafter referred to as "BuOH") and 15.6 g of 48% aqueous sodium hydroxide solution, and the temperature was raised to 60°C while stirring with a magnetic stirrer. Next, 100.0 g of allyl glycidyl ether (hereinafter referred to as "AGE") was added dropwise at a constant rate over 120 minutes to the reaction system maintained at 60°C while stirring, and then the temperature was maintained (aged) for an additional 180 minutes to complete the reaction. After cooling the reaction solution to 30°C, the reflux condenser was removed from the flask and a Liebig condenser, a 1 L receiver, and a nitrogen inlet tube were installed. The reaction system was then reduced in pressure to 4.0 kPa, and the reaction solution was heated to distill off unreacted BuOH and water until the temperature reached 100°C. The BuOH concentration in the reaction solution after the first purification step was 4.5%. Next, while maintaining the reaction solution at 100°C, nitrogen gas with an oxygen concentration of 0.1% by volume was introduced into the liquid phase of the flask at a rate of 5.2 mol% per hour relative to the AGE used in the reaction to distill off unreacted BuOH and water. The second purification step was completed in 150 minutes. During the second purification step, no foaming of the reaction solution, vibration, or contamination of the reaction apparatus was observed. The total amount of oxygen introduced into the reaction solution was as shown in Table 1. The total amount of oxygen was expressed as the number of moles relative to 100 moles of the amount of AGE charged in the reaction step. In this way, a composition containing 81.0% 1-allyloxy-3-butoxypropan-2-ol (hereinafter referred to as "A1B") and 0.92% BuOH was obtained. Samples of the composition were taken every 30 minutes from the start of the second purification step, and the degree of coloration was measured using the method described above. The results are shown in Table 1.

[0047] [Table 1]

[0048] <Example 2> The same procedure as in Example 1 was repeated except that the nitrogen gas introduced in the second purification step was changed to nitrogen gas with an oxygen concentration of 1.0% by volume. As a result, a composition containing 81.2% A1B and 0.95% BuOH was obtained, which was equivalent to the composition of Example 1. The composition was sampled every 30 minutes from the start of the second purification step and the degree of coloration was measured using the method described above, with the results shown in Table 2. The total amount of oxygen introduced into the reaction solution from the start of the second purification step per 100 moles of AGE was also shown in Table 2. The APHA of the composition obtained 150 minutes after the second purification step was also 200 or less.

[0049] [Table 2]

[0050] Example 3 The same procedure as in Example 2 was repeated except that the amount of nitrogen gas introduced in the second purification step was changed to 10.0 mol % per hour relative to the AGE used in the reaction, the oxygen concentration in the nitrogen gas was changed to 1.35 vol %, and the second purification step was carried out for 75 minutes. As a result, a composition containing 81.3% A1B and 0.86% BuOH was obtained, which was equivalent to the composition in Example 2. From the start of the second purification step, the composition was sampled every 15 minutes and the degree of coloration was measured by the method described above, with the results shown in Table 3. The total amount of oxygen introduced into the reaction solution from the start of the second purification step per 100 moles of AGE is also shown in Table 3. The APHA of the composition obtained after 75 minutes of the second purification step was also below 200.

[0051] [Table 3]

[0052] <Comparative Example 1> The same procedure as in Example 1 was repeated except that the amount of nitrogen gas introduced in the second purification step was changed to 5.2 mol % per hour relative to the AGE used in the reaction, the oxygen concentration in the nitrogen gas was changed to 5 vol %, and the second purification step was carried out for 150 minutes. As a result, a composition containing 81.3% A1B and 0.96% BuOH was obtained. From the start of the second purification step, the composition was sampled every 30 minutes and the degree of coloration was measured by the above-mentioned method, and the results are shown in Table 4. The total amount of oxygen introduced into the reaction solution from the start of the second purification step per 100 moles of AGE is also shown in Table 4. The APHA of the composition obtained 60 minutes after the second purification step already exceeded 200, and the butanol concentration was 1 mass% or more. Although butanol had been sufficiently removed from the composition obtained 150 minutes after the second purification step, the composition was significantly more colored than that obtained in Example 1.

[0053] [Table 4]

[0054] Example 4 The same procedure as in Example 1 was repeated except that the amount of nitrogen gas introduced in the second purification step was changed to 3.0 mol% per hour relative to the AGE used in the reaction, the oxygen concentration in the nitrogen gas was changed to 0.0001 vol%, and the second purification step was carried out for 240 minutes. As a result, a composition containing 81.8% A1B and 0.98% BuOH was obtained. The composition was sampled every 60 minutes from the start of the second purification step and the degree of coloration was measured by the above-mentioned method, with the results shown in Table 5. The total amount of oxygen introduced into the reaction solution from the start of the second purification step per 100 moles of AGE is also shown in Table 5. The APHA of the composition obtained after 240 minutes of the second purification step was also 200 or less.

[0055] [Table 5]

[0056] <Comparative Example 2> The same procedure as in Example 1 was repeated except that the amount of nitrogen gas introduced in the second purification step was changed to 10.0 mol % per hour relative to the AGE used in the reaction, the oxygen concentration in the nitrogen gas was changed to 5 vol %, and the second purification step was carried out for 75 minutes. As a result, a composition containing 81.5% A1B and 0.92% BuOH was obtained. From the start of the second purification step, the composition was sampled every 15 minutes and the degree of coloration was measured by the above-mentioned method, and the results are shown in Table 6. The total amount of oxygen introduced into the reaction solution from the start of the second purification step per 100 moles of AGE is also shown in Table 6. The APHA of the composition obtained 60 minutes after the second purification step already exceeded 200, and the removal of butanol in the composition obtained 75 minutes after the second purification step was sufficient; however, the coloring was much stronger than that obtained in Example 1.

[0057] [Table 6]

[0058] <Example 5> The same procedure as in Example 3 was repeated, except that the nitrogen gas introduced in the second purification step was changed to nitrogen gas with an oxygen concentration of 0.0001% by volume. As a result, a composition containing 81.5% A1B and 0.88% BuOH was obtained, which was equivalent to the composition of Example 3. The composition was sampled every 15 minutes from the start of the second purification step, and the degree of coloration was measured by the method described above, with the results shown in Table 7. The total amount of oxygen introduced into the reaction solution from the start of the second purification step per 100 moles of AGE is also shown in Table 7. The APHA of the composition obtained after 75 minutes of the second purification step was also below 200.

[0059] [Table 7]

[0060] Example 6 The same procedure as in Example 1 was followed, except that in the first purification step, the temperature of the reaction solution was increased to 110°C to distill off BuOH and water, in the second purification step the reaction solution was maintained at 110°C, the nitrogen gas introduced in the second purification step was changed to nitrogen gas with an oxygen concentration of 0.1% by volume, and the second purification step was carried out for 60 minutes. As a result, a composition containing 80.9% A1B and 0.88% BuOH was obtained, which was equivalent to the composition of Example 1. The composition was sampled every 30 minutes from the start of the second purification step, and the degree of coloration was measured by the method described above. The results are shown in Table 8. The APHA of the composition obtained after 60 minutes of the second purification step was also 200 or less.

[0061] [Table 8]

[0062] Example 7 The same procedure as in Example 6 was repeated, except that in the first purification step, the temperature of the reaction solution was increased to 120°C to distill off BuOH and water, in the second purification step the reaction solution was maintained at 120°C, the nitrogen gas introduced in the second purification step was changed to nitrogen gas with an oxygen concentration of 0.5% by volume, and the second purification step was carried out for 30 minutes. As a result, a composition containing 81.2% A1B and 0.75% BuOH was obtained, which was equivalent to the composition of Example 6. From the start of the second purification step, the composition was sampled every 15 minutes and the degree of coloration was measured by the method described above, with the results shown in Table 9. The APHA of the composition obtained 30 minutes after the second purification step was also 200 or less.

[0063] [Table 9]

[0064] Example 8 The same procedure as in Example 1 was followed, except that in the second purification step, the temperature of the reaction solution was maintained at 80°C, the amount of nitrogen gas introduced was changed to 10.0% per hour based on the AGE used in the reaction, and the second purification step was carried out for 270 minutes. As a result, a composition containing 81.7% A1B and 0.87% BuOH was obtained, which was equivalent to the composition of Example 2. The composition was sampled 240 minutes and 270 minutes after the start of the second purification step, and the degree of coloration was measured by the method described above. The results are shown in Table 10. The APHA of the composition obtained after 270 minutes of the second purification step was also 200 or less.

[0065] [Table 10]

[0066] Example 9 The same procedure as in Example 8 was repeated except that in the second purification step, the temperature of the reaction solution was maintained at 75°C, the nitrogen gas introduced was changed to nitrogen gas with an oxygen concentration of 0.01% by volume, and the second purification step was carried out for 300 minutes. As a result, a composition containing 81.7% A1B and 0.93% BuOH was obtained, which was equivalent to the composition of Example 8. The composition was sampled 240 minutes and 300 minutes after the start of the second purification step, and the degree of coloration was measured by the method described above. The results are shown in Table 11. The APHA of the composition obtained after 300 minutes of the second purification step was also 200 or less.

[0067] [Table 11]

[0068] From the results of the above Examples and Comparative Examples, it was found that by carrying out the second purification step so that the total amount of oxygen introduced into the reaction solution in the second purification step is in the range of 0.20 moles or less per 100 moles of AGE, i.e., the number of moles of epoxy group-containing compound charged, it is possible to produce an ether bond-containing compound with an APHA of 200 or less. It is also found that it is preferable to use nitrogen gas with an oxygen concentration of 3.0 volume % or less.

Claims

1. The following general formula (1): 【Chemical 1】 (In general formula (1), R １ represents a direct bond, a methylene group, or an ethylene group. ２ represents a hydrogen atom or a methyl group; and X represents an alkyl group having 1 to 6 carbon atoms. The production method includes the following general formula (2): 【Chemistry 2】 (In general formula (2), R １ , R ２ is the same as in general formula (1).) and an epoxy group-containing compound represented by the following general formula (3); X-OH (3) (wherein X is the same as in general formula (1)), a first purification step of removing the alcohol represented by the general formula (3) contained in the reaction solution after the reaction step; a second purification step of removing the alcohol represented by the general formula (3) from the reaction solution after the first purification step by distillation while introducing a gas containing an inert gas; the total amount of oxygen introduced into the reaction solution in the second purification step is 0.20 mol or less relative to 100 mol of the epoxy group-containing compound represented by the general formula (2) charged in the reaction step; The method for producing an ether bond-containing compound is characterized in that the oxygen concentration in the gas containing an inert gas used in the second purification step is 0.0001% by volume to 1.35% by volume.

2. 2. The method for producing an ether bond-containing compound according to claim 1, wherein the second purification step is carried out for 60 to 540 minutes.

3. 3. The method for producing an ether bond-containing compound according to claim 1, wherein the temperature of the reaction solution in the second purification step is 40 to 200°C.

4. The flow rate of the gas containing the inert gas introduced into the second purification step is determined by the following general formula (2): 【Chemistry 3】 (In general formula (2), R １ represents a direct bond, a methylene group, or an ethylene group. ２ represents a hydrogen atom or a methyl group.) in a reaction step, the reaction rate is 1.0 to 10.0 mol % per hour relative to 100 mol % of the epoxy group-containing compound represented by the formula (I).

Images