TW574207B - A method of manufacturing a (meth)acrylate - Google Patents

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574207 A7 B7 V. Description of the Invention (1) Technical Field The present invention relates to a method for manufacturing methacrylate (meaning acrylate or methacrylate). Conventional techniques are known in conventional methods for producing fluorenyl acrylates. For example, fluorinated acrylic acid and alcohol are dissolved in an organic solvent having the function of an azeotropic dehydration solvent, in the presence of a polymerization inhibitor and an acid catalyst. When necessary, a small amount of air is introduced to carry out the esterification reaction. After the reaction is completed, the unreacted methacrylic acid and the acidic catalyst are neutralized with an alkaline aqueous solution and removed, and then washed repeatedly with water several times as required before polymerization. In the presence of an inhibitor, an organic solvent is distilled off under reduced pressure from the recovered oil layer to obtain the target substance of methacrylic acid. When it is necessary to remove the organic solvent under reduced pressure, in order to avoid the thermal polymerization of the target methacrylic acid vinegar, it must be carried out at a lower temperature of 60 ° C ~ 95, so when the organic solvent is distilled off, Very long time, so that the productivity is low and the cost is disadvantageous. In order to solve this problem, a method has been conventionally adopted in which a large amount of air is introduced into the system from the time when the residual solvent concentration reaches 10 to 30% by weight, thereby promoting the distillation of the solvent. However, in this method, the products are colored by air oxidation, the use of the products is not good, and the effect of shortening the time is not sufficient. Furthermore, Japanese Patent Application Laid-Open No. 7-20706769 has disclosed a method of adding water to the system to remove the solvent by using Kyoho. However, in this method, the inside of the system is organic, and the latent heat of vaporization of the mixture must be added to the latent heat of water vaporization.

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574207 A7 --- _ B7 V. Description of the invention (2) The amount of heat supplied by the department is more than that required by the learner, and there is a problem that the manufacturing equipment is high and unfavorable to the manufacturing cost. In addition, if the heat cannot be supplied sufficiently, the effect of adding water is cancelled and the effect of shortening the time is insufficient. OBJECTS OF THE INVENTION The present invention has been made in view of the foregoing facts; the purpose is to provide a manufacturing method which can effectively distill off the solvent used in the esterification reaction in a short period of time in the production of methacrylic acid esters and suppress the product The methacrylate can be mass-produced by shortening the manufacturing time (process). SUMMARY OF THE INVENTION The present invention has been completed by focusing on such conventional problems. That is, the method for producing a methacrylic acid ester according to the present invention is characterized in that, in the method for producing a methacrylic acid ester, when the organic solvent is distilled from the recovered oil layer by a vacuum distillation method, the method includes the following steps. The step of introducing reduced pressure water vapor into the oil layer to distill the organic solvent under reduced pressure. DETAILED DESCRIPTION OF THE INVENTION As a method for producing methacrylic acid ester of amidopropionate, conventionally known methods can be used. For example, there are a direct esterification method, a transesterification method, and an oxidation gas method. The direct esterification method is simply that methacrylic acid and a high boiling point alcohol are subjected to an esterification reaction in the presence of a dehydrating azeotropic solvent and neutralized with a test aqueous solution, and then the oil layer is recovered while the oil layer is recovered. Then, a method of distilling off the organic solvent from the recovered oil layer by distillation under reduced pressure. Domestic Standard (CNS) A4 Specification (0X297 mm) '574207 A7 B7 V. Description of the Invention (Esterification method, in short, is to make methyl methacrylate and alcohol under a basic catalyst such as lithium hydroxide, A crude product of methacrylic acid vinegar is obtained by transesterification. In some cases, a solvent is used in the reaction. If there is an ester that cannot be distilled, in order to wash and refine the crude product, a solvent is added to perform oil-water separation. The method of oxidizing gasification is simply to use a base such as sodium hydroxide or an organic amine as a deoxidizing agent and esterify methylpropionyl chloride and alcohol to obtain a crude product of methacrylate. The method is a method using toluene or the like as a reaction solvent. No matter which method is used, the organic solvent must be distilled off from the recovered oil layer during the production process, and as the completion of this step, the target methyl propylene can be finally obtained. The purpose of the acid is as follows. In addition, the following description will be made based on the aforementioned direct esterification method. In the present invention, the alcohol used in the production of methacrylates has one or more hydroxyl groups, The point is a high boiling point, that is, as long as it is an alcohol of more than 180 force (with its upper limit barely reaching the "decomposition temperature of the compound"), it can be used without special restrictions. Also, an alkylene oxide can be used. Compounds such as (alkylene oxide) are used as alcohol derivatives. These alcohols can be used alone or in combination of two or more. Examples include phenylglycol and its homologs, and methoxyethylene. Alcohol, polyethylene glycol, polypropylene glycol, bisphenol A fired diol adduct, trimethylol propane, pentaerythritol, glycerol and their alkylene oxide adducts, etc. This paper size Applicable to China National Standard (CNS) A4 specification (21 × 297 mm) 6 Please read the precautions on the back before filling in. 丨 Write this page to order 574207 A7 —_______ B7 ___ 5. Description of the invention (4) Methyl acrylic acid and alcohol When the acetic acid reaction is carried out to produce f-based acrylate, the amount of methacrylic acid used is 1 to 2 times the equivalent of methacrylic acid relative to the hydroxyl equivalent of the alcohol, and preferably U to 15 times the equivalent. At 1 equivalent, The chemical reaction time is lengthened, and the obtained methacrylic acid esters are unfavorable to increase in high molecular weight. Moreover, when more than 2 times the equivalent of methacrylic acid is used, excess methacrylic acid that does not participate in the reaction will remain, It is also economically disadvantageous, and because the process of removing unreacted methacrylic acid from the crude reaction product is complicated and unsuitable. As the acid catalyst for catalyzing the esterification reaction, various conventional materials can be used. For example, sulfuric acid 'p-toluene luteinic acid, formic acid, etc. The amount of its use is divided into 1 to 10 parts by weight based on the total weight of the raw material alcohol and methacrylic acid, and 2 to 8 parts by weight are used. The organic solvent used in the esterification reaction of organic solvents may be exemplified by benzene, toluene, hexane, cyclohexane, and xylene; one type may be used alone, or two types may be used in combination. i 旨 化 反应 条 # The reaction temperature of the purifying reaction is about 60 ~ 140 ° C, preferably ~ 130 C. When the temperature is lower than 60 ° C, the reaction time will be prolonged. When the temperature exceeds 140 ° C, undesirable conditions such as polymerization may occur, and it is unsuitable to increase by-products. In the esterification reaction, a polymerization inhibitor can be used for the purpose of preventing the polymerization of fluorinated acrylic acid and fluorinated acrylic acid ester. It can be exemplified, for example, the paper size of hydrogen acid is applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm). 5. Description of the invention (5) Hydroquinone monomethyl ether, hydrogen flooding, p-phenylalanine, 2'4 -Well-known polymerization inhibitors such as dimethyl-6-t-butylphenol. In addition, a small amount of oxygen or air may be introduced into the reaction liquid as fine bubbles. The esterification reaction must proceed until no water is distilled off; the reaction time is about 5 to 20 hours. After the reaction, in order to remove the catalyst and excess methacrylic acid contained in the crude reaction product, neutralize it with an alkaline aqueous solution, remove the water layer, and rinse with bowl water as required, and then remove the water. Layer to obtain an oil layer. In order to distill off the organic solvent from the obtained oil layer, heating and stirring was performed at 60 = 95 ° C under reduced pressure. To prevent the polymerization of methacrylic acid vinegar, a small amount of oxygen or air may be introduced. Since it is kept at a relatively low temperature, it remains, and the dose ′ ⑼ will start at the point when the weight of methacrylic acid is 100 to 40% by weight, and the recovery rate of the solvent will decrease. Decompressed water steaming. In the present invention, from the point when the recovery rate of the solvent becomes slow, decompressed water vapor containing 10 to 200% by weight of the amount of the remaining solvent is introduced, while methacrylic acid containing the solvent Vinegar to promote the extraction of solvents. In this &amp; Ming, although the reduced pressure water vapor may be introduced from the initial stage of the distillation of the organic solvent, it will be from 40 to 1 () weight points based on 100 weight points of methacrylate. It is effective to lead people. That is, when the weight exceeds 40 weight points, in order to ensure the heat for vaporizing the solvent, extra investment is required in the heating equipment; when it is less than 10 weight points, the total distillation time of the solvent is lengthened. The effect of the invention becomes insufficient. The decompressed water vapor as referred to in the present invention refers to water vapor having a pressure lower than the atmospheric pressure 574 574207 V. Description of the invention (6 Please read the notes on the back and fill in <Hmm on the page mmHg); It will make the temperature shown closer to the liquid inside the steel. For the reason of the dish, it is better to take 6gg surface or less, surface is preferably ㈣, 300 is less than seven, and the better is to show the added pressure below 15mmHg. Gaseous water. There is no special method for obtaining decompressed steam. For example, the pressurized water vapor having a pressure higher than the atmospheric waste is passed through a sharp-hole pipe or a pinhole valve, and then introduced into a system with a desired degree of decompression. And get. Although there are no particular restrictions on the amount of reduced-pressure hydrotherapy gas introduced, the residual organic / cereal is preferably placed at 10 to 200% by weight. If it is less than 10% by weight, there is a possibility that a sufficient effect cannot be achieved; if it exceeds 200% by weight, it may remain in the product with moisture, and there may be too much time to remove the moisture. The appropriate range is 20 to 120% by weight. After the distilling agent was distilled off, the remaining liquid was filtered to obtain a colorless or pale yellow transparent fluorenyl acrylic acid vinegar. In the production of the methacrylic acid ester of the present invention, the time required for distilling off the solvent, which is conventionally 10 to 15 hours, is shortened to 4 to 6 hours. More specifically, the time required for distillation under reduced pressure until the final residual concentration of the organic solvent reaches 0.01% by weight can be shortened to less than 10 hours, even less than 9 hours, or even less than 8 hours. . An example of an embodiment of the present invention is described below. 1. A methacrylic acid ester manufacturing method, in which the methacrylic acid and the high boiling point (above 180 ° c, the upper limit of which is strictly limited to the decomposition temperature) ) Alcohol, esterification reaction in the presence of dehydrating azeotropic solvent, and the Chinese paper standard (CNS) A4 specification (21 × 297 mm; 574207; 574207) in the alkaline aqueous solution. V. Description of the invention (7) After that, the water layer is separated and the oil layer is recovered. From the recovered oil layer, the organic solvent used for dehydration | boiling and cereals is processed by vacuum distillation and is characterized by the following steps. The step of introducing reduced-pressure water vapor into the oil layer to distill the organic solvent under reduced pressure. 2. A method for producing methylpropionate is a method of methylpropionate using direct esterification. In the production method, methacrylic acid and an alcohol having a high stagnation point (above 180 ° t, the upper limit of which is strictly limited to the decomposition temperature) are subjected to an acetic acid reaction in the presence of a dehydrating common solvent, and the test is performed. After neutralizing aqueous solution The water layer and the oil layer are recovered at the same time. From the recovered oil layer, the organic solvent used as a dehydrating common Buddha solvent is subjected to vacuum distillation. The process includes the following steps. In the aforementioned oil layer, A step of pressurizing water vapor to distill the organic solvent under reduced pressure, thereby shortening the time required to distill the organic solvent. 3. A method for producing a methacrylic acid ester is a methyl ester using a direct esterification method. In the method for producing an acrylate, methacrylic acid and an alcohol having a high boiling point (above 180 C, the upper limit of which is strictly limited to the decomposition temperature) are subjected to an acetic acid reaction in the presence of a dehydrating common solvent, and then an alkaline After the aqueous solution is neutralized, the water layer is separated, and the oil layer is recovered. From the recovered oil layer, an organic solvent used as a dehydrating azeotropic solvent is subjected to a process of distillation under reduced pressure and is characterized by including the following steps. In addition, pressurized water vapor having a pressure higher than atmospheric pressure is produced, and gradually decompressed smoothly while passing through a thin tube, and then the decompressed water vapor is introduced into the oil layer and decompressed. Take into account the aforementioned organic solvents 'step of shortening the time required to distill off the organic solvents. This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm)'-574207 A7 --------- -B7__ V. Description of the invention (8) ~ — 4. A method for producing methylpropionate S is a method for producing methacrylic acid ester using a direct vinegarization method, in which Alcohols with a boiling point (above 180 C, the upper limit of which strictly reaches the decomposition temperature), undergo a brewing reaction in the presence of a dehydrating azeotropic solvent, and after neutralizing with a test aqueous solution, separate the water layer and recover the oil layer. From the recovered oil layer, an organic solvent to be used as a dehydrating azeotropic solvent is distilled under reduced pressure to remove the organic solvent. The process includes the following steps, which are to produce pressurized water vapor having a pressure of more than atmospheric pressure, and _ While gradually reducing the pressure through the thin tube, the reduced pressure water vapor is introduced into the oil layer, and the organic solvent is distilled under reduced pressure to form a final residual concentration of the organic solvent of 0% by weight. Decompression time required The step within 10 hours. Effects of the Invention According to the present invention, the solvent used in the esterification reaction can be efficiently distilled off in a short time, the coloration of the product can be suppressed, and the manufacturing time (manufacturing process) can be shortened. And because the manufacturing time (engineering) is shortened, it is possible to mass-produce trimethylpropionate S. Examples Hereinafter, the present invention will be described more specifically through examples, but the present invention is not limited by these examples. Example 1 A 300 liter capacity enamel reaction kettle equipped with a condenser with a water separator, a thermometer, an air blowing pipe and an airtight stirring device was charged with polyethylene glycol (MW = 400) 85 kg , 100kg of toluene, 6 kg of p-toluenesulfonic acid, 0.15 kg of hydroquinone, and 37 kg of acrylic acid. The dimensions of this paper are applicable to China National Standard (CNS) A4 (210X297 mm) -11-574207 A7 ______B7 _ V. Description of the invention (9) Steam is introduced from the sleeve while heating the air while stirring. Water began to distill at a reaction liquid temperature (reaction temperature) of 102 ° C. After about 8 hours, the water was distilled off at 123 ° C and cooled to 30. (: The following. The esterification reaction rate calculated from the distilled water is 99.5%. A test aqueous solution is slowly added to the reaction solution, neutralized below 40, and excess acrylic acid and catalyst are pumped out to the water tank. Remove the lower layer of water. Next, add 20 kg of 10% food bowl water, 槚: After mixing and let stand, remove the lower layer of water to obtain 180 kg of oil layer containing 100 kg of toluene. Equipped with a condenser, thermometer, water vapor blowing pipe, Air blowing tube and 300 liter capacity enamel distillation pin with air-tight stirring device, add the oil layer obtained in the above way, while passing 70 ° C warm water into the sleeve, while internal temperature is 70 ° C, vacuum Toluene was distilled off under reduced pressure at a degree of 100 to 30 mmHg. From the time when the remaining toluene became 20% (corresponding to 100 parts by weight of acrylic vinegar, 25 parts by weight), 2 kg / cm2 (about 130. Pressurized water vapor is passed through a pinhole valve in a 30 mmHg decompression system at a rate of 10 kg / Hr for 2 hours, and a total of 20 kg (% by weight of residual solvent) are introduced. From the end of the introduction After 30 minutes from the start, the remaining toluene was confirmed to be 0.1 weight ° / 〇. Distilled from toluene The time required is 4.5 hours. After filtering the residual liquid, a product of 76 kg of a pale yellow transparent liquid is obtained. The hue of the obtained product is 10, the acid value is 0.1〇11 ^ 1 ^ 011/8, and the moisture content is 0.02%. Example 2 In the same reaction pot as in Example 1, 88 kg of ethylene oxide adduct of bisphenol A (average EO addition mole number 10) and 134 kg of toluene were added. Chinese national standards were applied to the paper size. (CNS) A4 specification (210X297 mm) 12 Please! First: Read · Read ·: Back: No: Note: Italian | Things; Item: Win again: Book; Page; Order

574207 A7 -------- B7______ 5. Description of the invention (10) 5.8 kg of toluene sulfonic acid, 0.2 kg of hydroquinone and 29 kg of methacrylic acid. Heat and stir. Water began to distill at the reaction liquid temperature (reaction temperature) of 107 ° C, and after about 10 hours, it was cooled to below 30 ° C at the end of the distillation of 122 ^ water. The reaction rate of esterification calculated from the distilled water was 99.0%. A test aqueous solution was slowly added to the reaction solution at 40%. 〇 The following neutralization was used to remove excess methacrylic acid and catalyst from the water tank and remove the lower layer water. Next, 20 kg of 10% bowl water was added, and after stirring and standing, the lower layer of water was removed to obtain 22 kg of an oil layer containing 134 kg of toluene. In a 300 liter capacity enamel retort equipped with cold water, thermometer, water vapor injection pipe, air injection pipe, and air-tight stirring device, add the oil layer obtained in the above manner, and pass in warm water at 70 ° C. To the tube, toluene was distilled off under reduced pressure at an internal temperature of 70 μm and a vacuum of 100 to 30 mmHg. From the time when the remaining toluene became 25% (corresponding to 33 parts by weight based on 100 parts by weight of methacrylate), pressurized water vapor of 2 kg / cm2 (approximately 130.00) was passed through a pinhole valve, and A total of 17 · 5 kg (82% by weight of residual solvent) was introduced into the decompression system of approximately 50 mmHg at a rate of 7 kg / Hr for 2 · 5 hours. Toluene remained 30 minutes after the introduction was completed. It was confirmed to be 0.1% by weight. It took 5 hours from the distillation of toluene. After filtering the residual liquid, a light yellow transparent liquid of 85 kg was obtained. The hue of the obtained product was APHA of 20, and the acid value was 0.05 mgK. H / g, water content is 0.01%. Example 3 In the same reaction pot as in Example 1, add trimethylolpropane. The paper is sized for the Chinese National Standard (CNS) A4 (210X297 mm). 13 Read · What to do on the reverse page

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574207 A7 __ _ B7 __V. Description of the invention (11) (trimethylol propane) ethylene oxide calcined adduct (average EO addition mole number 3) 70 kg, toluene 138 kg, p-toluenesulfonic acid 7 kg, hydrogen 0.2 kg of quinone and 68 kg of acrylic acid were blown into the air and steam was introduced through the sleeve for heating and stirring. Water began to distill at the reaction liquid temperature (reaction temperature) of 110 ° C. After about 5 hours, the water was distilled off at 125 ° C and cooled to below 30 ° C. The reaction rate of the esterification calculated from the distilled water was 99.4%. An alkaline aqueous solution was slowly added to the reaction solution at 40 ° C. 〇 Neutralize the following, extract excess acrylic acid and catalyst out of the water tank, and remove the lower layer of water. Next, 20 kg of 10% food kneaded water was added, and after stirring and standing, the lower layer of water was removed to obtain 240 kg of an oil layer containing 13 8 kg of toluene. Into a 300-liter capacity enamel-distilled steel equipped with a condenser, a thermometer, a steam-blowing pipe, an air-blowing pipe, and an air-tight stirring device, add the oil layer obtained in the above manner, and pass 70 ° C warm water through. Into a sleeve, toluene was distilled off under reduced pressure at an internal temperature of 70 ° C and a vacuum of 100 to 30 mmHg. From the time when the remaining toluene became 10% (corresponding to 10 parts by weight based on 100 parts of acrylate), pressurized water vapor of 1.5 kg / cm2 through a pinhole valve in a 50 mmHg system at 10 kg At a rate of / Hr, a total of 20 kg (20% by weight of the residual solvent) was introduced by blowing for 2 hours. After 30 minutes from the end of the introduction, the residual toluene was confirmed to have a weight of 0/0, and it took 5 hours from the distillation of toluene. This residual liquid was filtered to obtain a product as a pale yellow transparent liquid 104. The hue APHA of the product was 10 'acid value 0.01 mgKOH / g, and the water content was 0.02%. Example 4 Please read and memorize 5 items of interest ί

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This paper size applies to China National Standard (CNS) A4 (210X297 mm) 14 574207 A7 B7

V. Description of the invention (丨 2) In the same reaction pot as in Example 1, 100 kg of cyclic ethane adduct (average EO addition mole number 4) of bisphenol A, 100 kg of toluene, 6 kg of p-toluenesulfonic acid, 0.15 kg of hydroquinone, and 43 kg of acrylic acid were blown into the air while being steamed through a sleeve for heating and mixing. Water began to distill at the reaction liquid temperature (reaction temperature) of 110 ° C. After about 4 hours, the water was distilled off at 123 ° C and cooled to below 30 ° C. The reaction rate of esterification calculated from the distilled water was 99.7%. Slowly add an alkaline aqueous solution to the reaction solution, neutralize it below 40 ° C, and pump excess acrylic acid and catalyst out of the water tank to remove the lower layer of water. Next, 20 kg of 10% bowl water was added, and after stirring and standing, the lower layer of water was removed to obtain 208 kg of an oil layer containing 100 kg of toluene. In a 300-liter capacity enamel-made retort equipped with a condenser, a thermometer, a water vapor injection pipe, an air injection pipe, and an airtight stirring device, add the oil layer obtained in the above manner, and pass warm water at 70 ° C through the jacket. Tube, toluene was distilled off under reduced pressure at an internal temperature of 70 ° C and a vacuum of 100 to 30 mmHg. From the point at which residual toluene becomes 33% (corresponding to 50 parts by weight based on 100 parts by weight of acrylate), pressurized water vapor of 2.0 kg / cm2 through a pinhole valve at 80 mmHg. It was blown in at a rate of 40 kg / capacitor for 3 hours, and a total of 120 kg (228% by weight of the residual solvent) was introduced. After 30 minutes from the end of the introduction, the remaining toluene was confirmed to be 0.1% by weight. 5.5 hours from the distillation of toluene. This residual liquid was filtered to obtain a pale yellow transparent liquid 1070. The hue of the known products is APHA 15, acid value (j og mgK〇H / g, moisture content 0.05%. 15) This paper size is applicable to China National Standard (CNS) A4 (21〇297297 mm) 574207 A7 B7 5 Description of the invention (i3) Example 5 In the same reaction pot as in Example 1, 80 kg of polyethylene glycol (MW = 300), 130 kg of toluene, 6 kg of p-toluenesulfonic acid, 0.2 kg of hydroquinone, and acrylic acid were added. 46 kg, while blowing in air, and passing steam through the sleeve to heat and stir. Water begins to distill at the reaction solution temperature (reaction temperature) 105 ° C. After about 9 hours, the water distills out at 120 ° C. At the end, cool to below 30 ° C. The reaction rate of esterification calculated from the distilled water is 99.4%. An alkaline aqueous solution is slowly added to this reaction solution, neutralized below 40 ° C, and excess acrylic acid, The catalyst was pumped out of the water tank to remove the lower layer of water. Next, 20 kg of 10% food short water was added, and after stirring and standing, the lower layer of water was removed to obtain 217 kg of an oil layer containing 130 kg of toluene. Equipped with a condenser, a thermometer, and a water vapor blowing pipe Air blowing into a 300 liter reaction pot made of enamel with a tube and an airtight stirring device The oil layer obtained in the above manner was added, while warm water at 70 ° C was passed into the sleeve, and toluene was distilled off under reduced pressure at an internal temperature of 70 ° C and a vacuum of 100 to 30 mmHg. The remaining toluene was changed to 33% At the point of time (corresponding to 100 weight points with respect to acrylate weight 50), pressurized water vapor of 2.0 kg / cm2 through a pinhole valve in a 75 mmHg system at a speed of 1 kg / Hr, Blow-in for 2 hours, a total of 2 kg (5% by weight of the residual solvent) was introduced. After 120 minutes from the end of the introduction, the residual toluene was confirmed to have a weight of 0/0, and it took 6 hours to remove the toluene. After filtration of this residual liquid, a product with a pale yellow transparent liquid 870 was obtained. The hue of the product was 10, the acid value was 0 μmgKOH / g, and the water content was 0.02%. The standard of this paper is the standard of the house. (CNS) A4 specification (21GX297 mm) 574207 A7 B7 V. Description of invention (i4) Example 6 In the same reaction pot as Example 1, 85 kg of polyethylene glycol (MW = 400) and 100 kg of toluene were added. 6 kg of p-toluenesulfonic acid, 0.15 kg of hydroquinone and 37 kg of acrylic acid, while blowing in air, and heating the steam through a sleeve Water began to distill at the reaction solution temperature (reaction temperature) of 102 ° C. After about 8 hours, the distillation of water ended at 122 ° C and cooled to below 30 ° C. The esterification was calculated from the distilled water. The reaction rate was 99.4%. An alkaline aqueous solution was slowly added to the reaction solution, neutralized below 40, and excess acrylic acid and catalyst were pumped out of the water tank to remove the lower layer water. Next, 20 kg of 10% food pinch water was added, and after stirring and standing, the lower layer of water was removed to obtain 180 kg of an oil layer containing 100 kg of toluene. In a 300 liter capacity enamel retort equipped with a condenser, a thermometer, a water vapor injection pipe, an air injection pipe, and an airtight stirring device, add the oil layer obtained in the above manner, and pass 70 ° C warm water into the jacket. Tube, with toluene at 70 ° C and 100 ~ 30 mmHg vacuum. From the time when the remaining toluene became 4.8% (equivalent to 5 parts by weight based on 1,000 parts by weight of acrylate), pressurized water vapor of 2.0 kg / cm2 through a pinhole valve in a 30 mmHg system, and A speed of 4.5 kg / Hr was blown in for 2 hours, and a total of 9 kg (225% by weight of the residual solvent amount) was introduced. After 30 minutes from the end of the introduction, the residual toluene was confirmed to have a weight of 0/0. It takes 6 hours from the distillation of toluene. This residual liquid was filtered to obtain 78 kg of a pale yellow transparent liquid. The hue APHA of the obtained product was 10, the acid value was 0.00 mgKOH / g, and the water content was 0.04%. This paper size is in accordance with Chinese National Standard (CNS) A4 (21 × 297 mm). Please read the notice first

Page 17 574207 A7 B7 V. Description of the invention Example 7 In the same reaction pot as in Example 1, 100 kg of ethylene oxide adduct of Shuangpan A (average EO addition mole number 4) and toluene 1 were added. 〇kg, p-toluene luteinic acid 6 kg, hydrogen g 0.15 kg and acrylic acid 43 kg, while blowing in air, and passing steam through a sleeve to heat and stir. Water began to distill at the reaction liquid temperature (reaction temperature) of 110 ° C. After about 4 hours, the water library was finished at i23 ° C and cooled to below 30 ° C. The reaction rate of esterification calculated from the distilled water was 99.7%. An alkaline aqueous solution was slowly added to the reaction solution to neutralize it at 40 ° C. The excess acrylic acid and catalyst were pumped out of the water tank to remove the lower layer water. Next, 20 kg of 10% food pinch water was added, and after stirring and standing, the lower layer of water was removed to obtain 208 kg of an oil layer containing 100 kg of toluene. In a 300 liter capacity enamel retort equipped with a condenser, a thermometer, a water vapor injection pipe, an air injection pipe, and an airtight stirring device, add the oil layer obtained in the above manner, and pass 70 ° C warm water into the jacket. Tube, and the toluene was evacuated under an internal temperature of 70 ° C and a vacuum of 100 to 30 mmHg. From the point when the remaining toluene became 4.8% (corresponding to 5 parts by weight with respect to 100 parts by weight of acrylate), 2.0 kg / cm2 of pressurized water vapor was passed through a pinhole valve in a system of 50 mmHg with 0. At a speed of i5 kg / Hr, it was blown in for 2 hours, and a total of 0.3 kg was introduced (5.6 weight ❶ / 〇 of the residual solvent amount). After 30 minutes from the end of the introduction, the residual toluene was confirmed to have a weight of 0 · 丨. / q. It took 6.5 hours from the distillation of toluene. After filtering this residual liquid, a product of 106.5 kg as a pale yellow transparent liquid was obtained. The hue of the obtained product is 10 APHA, and the acid value is (Mi mgKOH / g, 18) The paper size is applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) 574207 A7

Water is divided into 0.02%. Example 8 In the same reaction pot as Example 1, 100 kg of ethylene oxide adduct of bisphenol A (average EO addition moles 4), 100 kg of toluene, and 6 kg of p-toluenesulfonic acid were added. , Hydroquinone 0.15 kg and acrylic acid 43 kg, while blowing in air, and passing steam through a sleeve to heat and stir. Water began to distill at the reaction liquid temperature (reaction temperature) of 110 ° c. After about 4 hours, the water was distilled off at 123 ° c and cooled to below 30 ° c. The reaction rate of esterification calculated from the distilled water was 99.7%. ○ An alkaline aqueous solution was slowly added to the reaction solution, and neutralized below 400c. The excess acrylic acid and catalyst were pumped out of the water tank to remove the lower water. . Next, 20 kg of 10% bowl water was added, and after stirring and standing, the lower layer of water was removed to obtain 208 kg of an oil layer containing 100 kg of toluene. In a 300-liter capacity enamel retort equipped with a condenser, a thermometer, a water vapor oxygen injection tube, an air injection tube, and an air-tight stirring device, add the oil layer obtained in the above manner, and pass 70 ° C warm water into it. In a sleeve, toluene was distilled off under reduced pressure at an internal temperature of 70 ° C and a vacuum of 200 to 100 mmHg. From the time when the remaining toluene was 20% (25 weight points relative to 100 weight of acrylic acid ester), pressurized water vapor of 2.0 kg / cm2 through a pinhole valve at 170 mmHg It was blown in at a rate of 15 kg / Hr for 2 hours, and a total of 30 kg (11% by weight of the residual solvent amount) was introduced. 120 minutes after the introduction was completed, residual toluene was confirmed to be 0.1% by weight. It takes 8 hours from the distillation of toluene. After filtering this residual liquid, a light yellow transparent liquid with a size of 106.7 kg was obtained. The paper size is in accordance with Chinese National Standard (CNS) A4 (210X297 mm). 19 Please read the notices before filling out this page.

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/ 4207 V. Description of the invention (1 product. The hue of the obtained product is APHA 5 and the acid value is 3 mgKOH / water is 0.06%.

Comparative Example J A comparative experiment described below was performed as a control test of Example 1. : At the time when the residual toluene became 19%, the amount of air introduced was 0.5 L / min 5 times the amount of Example 1 to replace the water vapor, and the distillation was continued under reduced pressure. After 13 hours, residual toluene was confirmed to be 013%. Page This residue was filtered to obtain a yellow transparent 76 kg product. The hue APHA of the obtained product was 200, the acid value was 15 mgKOH / g, and the moisture content was 0.01%. Comparative Example 2 A comparative experiment described later was performed as a control test of Example 丨. That is, when the residual toluene becomes 20%, water vapor is not introduced, and distillation under reduced pressure is continued without increasing the amount of air introduced. After 5 hours, the residual toluene was confirmed to be 0.15%. This residual liquid was filtered to obtain a product of 76 kg of yellow transparent body. The obtained product had a hue APHA of 25, an acid value of 0.1 mgKOH / g, and a moisture content of 0.01%. Comparative Example 3 A comparative test described below was performed as a control test of Example 2. That is, when the remaining toluene becomes 25%, π kg of water at normal temperature is added to replace water vapor and distillation under reduced pressure is continued. During the phase of adding water, the temperature of the liquid in the system decreased sharply. Thereafter, it was slowly returned to the original temperature (about 5 hours), and distillation under reduced pressure was continued. After 12 hours, residual toluene was confirmed to be 0.12%. This paper size is in accordance with Chinese National Standard (CNS) A4 specification (210X297 mm). 20 5. Description of the invention (18) The residual liquid is filtered to obtain a yellow transparent product of 84 kg. The obtained product had a hue APHA of 250, an acid value of 0.1 mgKOH / g, and a moisture content of ⑽%. Comparative Example 4 A comparative experiment described later was used as a control test 2 of Example 3. When the residual fbenzene reached 9%, water was added instead of water vapor, and steam distillation was continued. During the water addition phase, the liquid temperature in the system decreased sharply. After that, slowly return to the original temperature (about 5 hours) and continue to save money. After 14 hours, residual toluene was confirmed to be 0.01%. This residue was filtered to obtain a product of 101 kg as a yellow transparent body. The obtained product had a hue of APHA of 150, an acid value of 0 "mgKOH / g, and a moisture content of 0.01%. The above experimental results are summarized as "Table 1" and "Table 2" below. 574207 A7 B7 V. Description of the invention (l9) Table 1 The phase of the pressure-reduced water vapor introduction phase to the pressure of the weight of the acrylic acid vinegar 100 weight pressure (mmHg) The introduction speed (Kg / hr) time and The total amount is slow. The remaining solvent amount is the time required for solvent distillation. APHA Acid value mgKOH / g Toluene _ Storage% wt. Example 1 It becomes 25% by weight 30 10 2 hours 100% by weight 4.5 10 0.10 0.1 Example 2 becomes 33% by weight about 50 7 2.5 hours 82% by weight 5 20 0.05 0.1 Example 3 becomes 10% by weight 50 10 2 hours 20% by weight 5 10 0.1 0.1 Example 4 becomes 50% by weight 80 40 3 hours 228% by weight 5.5 15 0.09 0.1 Example 5 becomes 50% by weight 75 1 2 hours 5% by weight 6 10 0.14 0.1 Example 6 becomes 5% by weight 30 4.5 2 hours 225% by weight 6 10 0.10 0.1 Example 7 5 weight division 50 0.15 2 hours 5.6% by weight 6.5 10 0.11 0.1 Example 8 25 weight division 170 15 2 hours 110% by weight 8 15 0.13 0.1 Table 2 Residual solvent distillation status APHA Acid value mgKOH / g toluene The final content of the residual concentration wt% Comparative Example 1 after 13 hours Yue residual benzene 0.13% was confirmed. 200 0.15 0.13 Comparative Example 2 The residual toluene content after 15 hours was confirmed to be 0.15%. 25 0.1 0.15 Comparative Example 3 The residual toluene content after 12 hours was confirmed to be 0.12%. 250 0.1 0.12 Comparative Example 4 The residual toluene content after 14 hours was confirmed to be 0.10%. 150 0.1 0.10 This paper size is in accordance with Chinese National Standard (CNS) A4 (210X297mm) 22 Please read the note of Wengbei before ordering on this page

Claims (1)

574207- 1 Bulletin Patent application scope I A method for cracking Si in formazan, which is characterized in that, in the method for producing methacrylic acid ester, when the organic solvent is removed from the recovered oil reservoir by vacuum distillation, the method includes: The following step is a step of distilling the organic solvent under reduced pressure while introducing reduced-pressure water vapor into the oil layer. 2. A method for producing methacrylate, characterized in that, in the method for producing methacrylate, when the organic solvent is distilled off from the recovered oil layer by vacuum distillation, the method includes the following steps: Water vapor is introduced into the oil layer under reduced pressure, and the organic solvent is distilled under reduced pressure, thereby forming a step of shortening the distillation time required for the organic solvent. 3. A method for producing methacrylic acid ester, characterized in that, in the method for producing methacrylic acid vinegar, when the organic solvent is distilled off from the recovered two layers by vacuum distillation, the method includes the following steps: ^ Pressurized water vapor at a pressure higher than atmospheric pressure, while gradually passing through the tube to gradually reduce the pressure, and then introduce the reduced pressure water vapor into the aforementioned oil layer, so as to reduce the pressure of the organic solvent to form the age. The step of distillation time required for the organic solvent. 4. A method for producing methacrylic acid vinegar, characterized in that, in the method for producing methacrylic acid vinegar, the organic solvent is distilled from the recovered I layer by distillation under reduced pressure, including the following steps, That is, a pressurized water-based gas having a pressure higher than atmospheric pressure is also produced, and-while passing through a thin tube, the pressure is gradually reduced, and then the reduced-pressure water vapor is introduced into the oil layer to reduce the pressure of the organic solvent. Agent to form a decompression hall to remove the organic solvent to the final remaining concentrated production, (please read the precautions on the back before filling this page) · n —ii I n II n 1: ° J II · ϋ II an n ϋ _ Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 23 574207 A8 B8 C8 D8 VI. Step of applying for patent 0.1% by weight, the time required is within 10 hours. 5. The method described in any one of claims 1 to 4 of the scope of the patent application, wherein the decompressed water is introduced from the time when the residual organic solvent becomes 40 to 10 weight percent based on 100 weight percent of the methacrylate. Steam. 6. The method according to any one of claims 1 to 4 in the scope of the patent application, wherein the introduction amount of the reduced pressure water vapor is 10 to 200% by weight of the residual organic solvent. 7 · = The method described in item 5 of the scope of the patent application, wherein the introduction amount of the reduced pressure water vapor is from 0 to 200% by weight of the residual organic solvent. 8. The method as described in any one of items 1 to 4 of the scope of patent application, wherein the vapor pressure of the aforementioned decompressed water vapor is 300 mmHg or less. 9_ The method described in item 5 of the Chinese Patent Application, where M is from 8 to τ, and the pressure of the decompressed ice α milk is 300 mmHg or less.丨 〇 As described in item 6 of the scope of the patent application, the steam pressure of the reduced pressure icing rolls is less than 300 mmHg. ^ Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs