JP4549324B2 - Method for producing dehydration reaction product - Google Patents

Description

The present invention provides a method for producing a dehydration reaction product comprising a dehydration reaction step in which an alcohol and / or amine and (meth) acrylic acid are esterified and / or amidated in the presence of a dehydration solvent, and obtained thereby. The present invention relates to a method for producing a cement additive.

A method for producing a dehydration reaction product comprising a dehydration reaction step is applied to the production of various esters and amides produced by reactions involving dehydration reactions such as esterification and amidation. Such esters and amides are useful as raw materials for producing various polymers, for example, as (meth) acrylic acid ester monomers and (meth) acrylic acid amide monomers. Such polymers include, for example, cement additives (cement dispersants), calcium carbonate, carbon black, pigment dispersants such as ink, scale inhibitors, gypsum / water slurry dispersants, coal / water slurry (CWM). It is suitably used for chemical products such as dispersants and thickeners.

By the way, in the dehydration reaction step, the esterification reaction or amidation reaction is a reaction that reaches chemical equilibrium. Therefore, if the by-product water produced is not removed from the reaction system, that is, if the produced water is accumulated in the reaction system, The reaction to produce an amidate does not proceed. Therefore, the generated water is removed by distilling (azeotropically) this and the generated water using a dehydrated solvent. For example, a method of separating and removing generated water from the distillate, refluxing the dehydrated solvent to the reaction system and performing the reaction, and removing the dehydrated solvent by removing it from the reaction vessel containing the esterified product or amidated product after the reaction is completed. It has been.

As a conventional production method, a reactor (separable flask) is provided with a thermometer, a stirrer, and a generated water separator, and a reaction apparatus that can separate generated water is used as raw materials with methacrylic acid and methoxypolyethylene glycol (oxyethylene). The average number of moles of the group added: 10 mol), sulfuric acid (Comparative Example 1) or p-toluenesulfonic acid (Comparative Example 2) as the acid catalyst, phenothiazine as the polymerization inhibitor, and cyclohexane as the dehydrating solvent were heated with stirring. The cyclohexane-water azeotrope is distilled off under pressure, the cyclohexane is refluxed while removing the produced water with a water separator, and the esterification reaction is performed. A method of synthesizing an esterified product is disclosed (for example, see Comparative Examples 1 and 2 in Patent Document 1).

However, in such a manufacturing method, after distilling the distillate with a condenser, the dehydrated solvent is refluxed while forming the interface between the dehydrated solvent and the produced water using a water separator to remove the produced water. However, when the distillate condensed and liquefied by the condenser is discharged to the water separator, there are the following problems.

That is, (A) If a distillate discharge port is provided in the gas phase part of the water separator, the interface will be shaken by impact when the distillate reaches the liquid level, and the interface between the dehydrated solvent and the produced water will be It cannot be detected accurately. On the other hand, when the discharge port is provided in the liquid phase part of the water separator, not only is the interface swayed, but pressure is applied to the discharge port when distillate is discharged, and from the discharge port at the moment of discharge. The inside of the pipe connected to the reaction tank through the condenser is in a depressurized state, so that a pressure fluctuation occurs in the reaction tank, and the reaction liquid in the reaction tank bumps. (B) The interface cannot be detected accurately. In particular, when the amount of generated water is small or the liquid level is shaken, it is difficult to detect with high accuracy. (C) In the liquid level gauge attached to the water separator, since there is little substantial replacement of the liquid and the liquid pool is generated, a polymerizable such as (meth) acrylic acid distilled with the dehydrated solvent and the generated water is used. The monomer is polymerized to form a gel, so that the liquid level gauge does not function. There was a problem. When such a problem occurs, not only the dehydration reaction product cannot be stably produced, but also the safety is lowered, the repair cost is increased, and the production cost of the dehydration reaction product is increased.
JP-A-9-328346 (pages 10 and 11)

The present invention has been made in view of the above situation, and includes a dehydration reaction step of esterifying and / or amidating alcohol and / or amine and (meth) acrylic acid in the presence of a dehydrating solvent, A method for producing a dehydration reaction product using a reaction vessel and a water separator as essential components, wherein (A) the by-product water produced is removed from the reaction system, while preventing bumping of the reaction solution, and (B) dehydration. By improving and stabilizing the detection accuracy of the interface between the solvent and the produced water, and (C) the formation of the gel-like substance is sufficiently suppressed, the occurrence of defects in the production process is sufficiently prevented. It aims at providing the manufacturing method of the dehydration reaction product which can be suppressed.

The present invention is a method for producing a dehydration reaction product comprising a dehydration reaction step of esterifying and / or amidating an alcohol and / or amine and (meth) acrylic acid in the presence of a dehydrating solvent, The dehydration reaction step is performed using a reaction vessel and a water separator as essential, the water separator is provided with a supply pipe connected to the reaction vessel, and a gas phase part and a liquid phase part are provided therein. The dehydration reaction product is controlled such that the lower diameter is smaller than the upper diameter and the interface between the dehydrating solvent and generated water is maintained at the lower portion.

The present invention is also a method for producing a dehydration reaction product comprising a dehydration reaction step of esterifying and / or amidating an alcohol and / or amine and (meth) acrylic acid in the presence of a dehydrating solvent, The dehydration reaction step is performed using a reaction tank and a water separator as essential, and the water separator is provided with a supply pipe connected to the reaction tank, and a gas phase part and a liquid phase part are provided therein. And a device for detecting the interface between the dehydrated solvent and the produced water and / or the gas-liquid interface, and a method for producing a dehydrated reaction product in which an antigelling agent is allowed to act inside the detection device.

As a result of diligent research to efficiently produce a high-quality dehydration reaction product, the present inventors have devised the supply pipe provided in the water separator used in the (A) dehydration reaction step, and the reaction solution suddenly boiled. (B) the interface between the dehydrated solvent and the produced water is stabilized and the detection accuracy is improved, and (B) the detection accuracy of the interface between the dehydrated solvent and the produced water is improved by devising the shape of the water separator; It has also been found that if the detection device provided in the water separator is devised, clogging with a gel-like substance in the detection device is sufficiently suppressed. Specifically, (1) the supply pipe provided in the water separator is set so as to have an opening in the gas phase portion and the liquid phase portion in the water separator, and (2) the shape of the water separator The lower diameter is smaller than the upper diameter, and the interface between the dehydrated solvent and the generated water is kept at the lower part, and (3) gelation is prevented inside the detection device provided in the water separator. The inventors have conceived that the above-mentioned problems can be solved brilliantly by acting an agent, and the present invention has been achieved. Further, since the product obtained by the method for producing a dehydration reaction product using such a water separator is of high quality, this product is preferably used as a raw material for producing a polymer for cement additives. It has also been found that it can be used.
The present invention is described in detail below.

The method for producing a dehydration reaction product of the present invention comprises a dehydration reaction step of esterifying and / or amidating an alcohol and / or amine and (meth) acrylic acid in the presence of a dehydrating solvent. The form of (2) above, that is, the dehydration reaction step is performed using a reaction tank and a water separator as essential, and the water separator is provided with a supply pipe connected to the reaction tank, and In addition to having a gas phase portion and a liquid phase portion inside, the lower diameter is smaller than the upper diameter and the interface between the dehydrated solvent and the generated water is controlled to be maintained at the lower portion, or The form of (3) above, that is, the dehydration reaction step is performed using a reaction tank and a water separator as essential, the water separator is provided with a supply pipe connected to the reaction tank, and It has a gas phase part and a liquid phase part inside, and a boundary between dehydrated solvent and generated water. And / or liquid interface detector is provided in the form to act anti-gelling agent in the interior of the detection device. Preferably, the form of (1) above, that is, the dehydration reaction step is performed using a reaction tank and a water separator as essential, and the water separator is provided with a supply pipe connected to the reaction tank. And a gas phase part and a liquid phase part inside, and the supply pipe has an open port in the gas phase part and the liquid phase part, and the modes (2) and / or (3) above Is a combination of
Below, it demonstrates in order of the form of said (1), (2) and (3).

The method for producing a dehydration reaction product of the present invention comprises a dehydration reaction step of esterifying and / or amidating an alcohol and / or amine and (meth) acrylic acid in the presence of a dehydrating solvent. Moreover, in the form normally implemented of the manufacturing method of such a dehydration reaction product, following the dehydration reaction process, the neutralization process mentioned later, a solvent distillation process, etc. are included.

First, the apparatus in the present invention used in the dehydration reaction step will be described.
The dehydration reaction step is performed using a reaction tank and a water separator as essential, and the water separator is provided with (1) a supply pipe connected to the reaction tank, and a gas phase section inside. A liquid phase part, and the supply pipe has an opening in the gas phase part and the liquid phase part. (2) a supply pipe connected to the reaction vessel is provided, and the gas phase part is provided inside. And a liquid phase part, and the lower diameter is smaller than the upper diameter, and the interface between the dehydrated solvent and the generated water is maintained at the lower part. (3) Connected to the reaction vessel And a gas phase part and a liquid phase part inside, and a detection device for the interface between the dehydrated solvent and the generated water and / or the gas-liquid interface is provided inside the detection device. It is the form of (2) or (3) among the forms in which the anti-gelling agent acts, or the form combining these. A preferable form of such a water separator is a form in which all of the above (1) to (3) are combined.
In the present invention, the water separator is used, for example, the distillate vaporized in a reaction tank and condensed and liquefied by a condenser is separated into a dehydrated solvent and produced water, and the dehydrated solvent is reacted while removing the produced water. The operation of refluxing to the tank will be performed.

In addition, a distillate means all the things distilled from a reaction tank by a dehydration reaction process and other processes. That is, the reaction product water distilled off from the reaction vessel, the product water from the raw material charged in the form of an aqueous solution, and a dehydrated solvent used for azeotroping with the product water as needed, was distilled (meta ) Means containing reaction raw materials such as acrylic acid, and examples of the form include gaseous and liquid forms.

The method for producing a dehydration reaction product of the present invention preferably combines the above-mentioned form (1).
In the form (1), the supply pipe has open ports in the gas phase portion and the liquid phase portion. In this case, the liquid distillate is supplied from the opening of the liquid phase part of the supply pipe into the water separator, and the gaseous distillate is discharged from the opening of the gas phase part. It is possible to suppress fluctuations in the pressure of the liquid phase portion in the inside, and thereby it is possible to further exert the effects of the present invention.

In the water separator, the supply pipe connected to the reaction tank is a pipe for supplying a distillate from the reaction tank into the water separator. The form in which the reaction vessel and the water separator are connected is usually connected via a condenser, but is particularly limited as long as the distillate from the reaction vessel is supplied into the water separator. It is not something. The supply pipe may be a single pipe or a plurality of pipes, and may be branched or unbranched. Further, when branched, it has a branch pipe. For example, even if it has a branch pipe from the gas phase part to the liquid phase part, it is directed from the liquid phase part to the gas phase part. And may have a branch pipe. Furthermore, the cross-sectional shape is not particularly limited, and for example, a circular shape is preferable. Such a supply pipe is preferably in the form of a single pipe (circular pipe) having a circular cross section and no branch pipe. An open port means the supply port into the water separator of the distillate supplied from a supply pipe, and is a 1 or several hole provided in the front-end | tip and side surface of a supply pipe or a branch pipe. Although there is no restriction | limiting in particular as a shape of such an open port, For example, it is preferable that it is circular.

In the form of (1), it is preferable that the opening of the gas phase part of the supply pipe is one or a plurality of holes formed in the side surface of the supply pipe. More preferably, it is preferable to devise so that liquid distillate is not ejected by discharging only gas through the opening of the gas phase portion. The diameter of the opening to the gas phase is preferably 1 to 200 mm, more preferably 5 to 100 mm, and even more preferably 10 to 50 mm. The number of open ports in the gas phase part is preferably 1 to 50, for example, depending on the size. More preferably, it is 1-10. By doing in this way, it becomes possible to fully suppress the fluctuation | variation of the pressure of the liquid phase part in a water separator.

In the mode (1), it is preferable that the water separator is further provided with a baffle plate, and the opening of the gas phase portion of the supply pipe is in the direction opposite to the baffle plate. By providing the baffle plate, in the liquid phase part in the water separator, the dehydrated solvent is present in the upper phase and the generated water is present in the lower phase (A), and overflow (overflow) from above the baffle plate. ) And the chamber (B) where the dehydrated solvent is present, the generated water can be efficiently removed and the dehydrated solvent can be refluxed. At this time, the opening of the liquid phase part of the supply pipe is in the chamber (A), and if the opening of the gas phase part of the supply pipe is in the direction opposite to the baffle plate, The distillate to be discharged is prevented from being mixed into the chamber (B), thereby preventing the generated water from being mixed in the dehydrated solvent to be refluxed.

In the form of (2) in the method for producing a dehydration reaction product of the present invention, the lower diameter of the water separator is smaller than the upper diameter, and the interface between the dehydrating solvent and the generated water is kept at the lower part. Will be controlled. Thereby, the detection accuracy of the interface between the dehydrated solvent and the generated water can be improved. Therefore, it is possible to stably perform the dehydration reaction in the dehydration reaction process by accurately controlling the reflux amount of the dehydrated solvent and the amount of extracted water and maintaining a stable interface between the dehydrated solvent and the generated water. It becomes. In this case, the form in which the diameter of the lower part becomes thinner than the diameter of the upper part includes, for example, a form that gradually or continuously narrows from the upper part to the lower part. It is preferable that the lower diameter is substantially constant and the lower diameter is smaller than the upper diameter. By making the diameter of the lower part substantially constant, the liquid volume can be easily converted from the height of the interface, and there is no error due to complicated calculation. In addition, as a method for controlling the interface between the dehydrated solvent and the produced water to be kept at the lower part, for example, the distillate is detected in the water separator while detecting the interface between the dehydrated solvent and the produced water using an interface meter. The speed can be adjusted by adjusting the speed supplied to the inside and the speed at which the dehydrated solvent and produced water separated in the water separator are removed to the outside of the water separator. At this time, it is preferable to control the position of the interface by adjusting the opening of the control valve.

In the form of (3) in the method for producing a dehydration reaction product of the present invention, the water separator is provided with a detection device for the interface between the dehydration solvent and the generated water, and the antigelling agent acts inside the detection device. I will let you. Further, when the water separator is further provided with a baffle plate and a detection device for the interface between the gas phase portion and the liquid phase portion (dehydrated solvent) is provided in the chamber (B), the inside of the detection device is also gelled. It is preferable to make an inhibitor act. By causing an anti-gelling agent to act inside the detection device, it is sufficiently suppressed that the detection device is clogged with a gel-like material, causing problems in the manufacturing process and the performance and quality of various chemical products. The decrease can be sufficiently suppressed. The detection device is not particularly limited as long as it has a means capable of detecting the interface. For example, an apparatus having a detecting means using a specific gravity difference or electric resistance is mentioned. As will be described later in FIG. 1, a distillate liquefied from a water separator is introduced into a pipe to detect an interface, so-called It is preferable to use an interface meter.

Examples of the anti-gelling agent include polymerization inhibitors, and specific examples include phenothiazine, tri-p-nitrophenylmethyl, di-p-fluorophenylamine, diphenylpicrylhydrazyl, N- ( 3-N-oxyanilino-1,3-dimethylbutylidene) aniline oxide, benzoquinone, hydroquinone, methoquinone, butylcatechol, nitrosobenzene, picric acid, dithiobenzoyl disulfide, cuperone, copper (II) chloride and the like. These may be used alone or in combination of two or more. Among these, it is preferable to use phenothiazine, hydroquinone, and methoquinone.

The amount of the above-mentioned gelation inhibitor is appropriately set to an amount suitable for the amount of distillate depending on, for example, the dehydration reaction conditions, especially the amount of heat acting on the reaction system and the amount of dehydrated solvent charged into the reaction system. For example, it is preferable to set it as 0.1-5000 weight ppm with respect to the total weight of the charging amount of alcohol and amine which are reaction raw materials, and (meth) acrylic acid. If the amount is less than 0.1 ppm by weight, the effect of the gelation inhibitor may not be sufficiently exhibited. If the amount exceeds 5000 ppm by weight, the expression of the effect corresponding to the amount to be acted on cannot be expected, which is uneconomical. There is a risk of becoming. More preferably, it is 5 to 500 ppm by weight.

The method for causing the anti-gelling agent to act on the detection device is not particularly limited as long as it is a method that can effectively exhibit the action and effect of the anti-gelling agent. For example, a nozzle is provided at a site in the detecting device to be acted on. An antigelling agent can be injected from the nozzle. The site to be acted on is preferably near the interface between the dehydrated solvent and the generated water or near the interface between the gas phase part and the liquid phase part (dehydrated solvent). In addition, the time of action is when the dehydrating solvent or water is present in the water separator. In particular, it is preferable to act while a polymerizable monomer such as (meth) acrylic acid is present in the dehydrating solvent or water phase of the water separator. In particular, it is preferable to act when the monomer is supplied to the water separator, that is, during the dehydration of the dehydration reaction product or during the dehydration solvent distillation. Furthermore, examples of the form of the antigelling agent to be acted include a form liquefied (dissolved) with a solvent, a solidified form such as a powder, a vaporized form including a sublimated state, etc. Among these, a solvent or the like It is preferable to use a form liquefied by the above, particularly a form liquefied by the same kind of solvent as the dehydrated solvent.

The material of the water separator and the supply pipe and baffle plate provided in the present invention is not particularly limited, and known materials can be used. For example, SUS304, SUS316, preferably SUS304, SUS316, SUS316L, More preferably, SUS316, SUS316L, etc. are mentioned. Further, the inside of the water separator may be subjected to glass lining processing, Teflon (registered trademark) processing, or the like to be inert to the corrosiveness of the reaction raw materials and products.

The water separator in the present invention will be described with reference to FIG.
FIG. 1 is a conceptual diagram illustrating a water separator in the present invention. In FIG. 1, a supply pipe is provided, a gas phase part and a liquid phase part are provided therein, a baffle plate is further provided, and an interface meter (A ) And an interface meter (B) as a device for detecting the gas-liquid interface between the gas phase part and the liquid phase part (dehydrated solvent) in the water separator chamber (chamber (B)) opposite to the supply pipe from the baffle plate One form of the water separator which is provided and has a product water outlet and a dehydrated solvent outlet at the bottom is shown. In this form, the opening of the gas phase section of the supply pipe is a plurality of holes formed in the side surface of the supply pipe, and is in the direction opposite to the baffle plate, and the diameter of the lower part of the water separator is A control valve (not shown) is provided in the pipe that is narrower than the upper diameter and connected to the product water outlet and the dehydrated solvent outlet, and is controlled so that the interface between the dehydrated solvent and the produced water is maintained at the lower part. The nozzle is controlled by a valve, and further provided with a nozzle (anti-gelling agent injection port) for allowing the anti-gelling agent to act inside the interfacial meter (A) and interfacial meter (B).

In FIG. 1 above, the supply pipe is connected to a condenser (not shown), and the gaseous distillate generated in the reaction tank is condensed and liquefied by the condenser, passes through the supply pipe, and is provided on the supply pipe side from the baffle plate. In the chamber [A], the generated water accumulates in the lower phase and the dehydrated solvent accumulates in the upper phase. Further, the dehydrated solvent collected in the upper phase of the chamber (A) flows over the baffle plate and enters the chamber (B) and accumulates. The generated water accumulated in the chamber (A) is removed from the generated water outlet by being adjusted by the control valve while detecting the interface with the interface meter (A) so that the interface between the dehydrated solvent and the generated water is at a fixed position. The dehydrated solvent accumulated in the chamber (B) is adjusted by the control valve while detecting the interface with the interface meter (B), extracted from the dehydrated solvent outlet, and returned to the reaction vessel. At this time, an anti-gelling agent acts inside the interfacial meter (A) and the interfacial meter (B) to prevent clogging due to the formation of a gel-like material. In FIG. 1, the dehydrated solvent and the generated water are indicated by oblique lines.

In FIG. 1 above, as the positions of the gas phase part and the liquid phase part opening port of the supply pipe, for example, distillate from the gas phase part or liquid phase part opening port enters the chamber (B). It is preferable to set in a place where it is difficult to adhere to the inner wall of the water separator. Further, it is preferable that the baffle plate is sufficiently high. If the baffle plate is too low, the distillate may overflow over the baffle plate before entering the chamber (B) before the distillate is separated into the dehydrated solvent and generated water in the chamber (A). Moreover, it is because the capacity of the water separator cannot be fully utilized effectively.

In the form of FIG. 1, it is preferable that the lower diameter of the water separator is set to be sufficiently thinner than the upper diameter. For example, it is preferable that the ratio of the diameters of the lower and upper diameters is set to 1/20 to 1/2. If the diameter of the lower part is less than 1/20, if the height is not increased, the water storage capacity is reduced and the water separator may become too large. If the diameter of the lower part is less than 1/2, There is a possibility that the detection accuracy of the interface with the generated water is not sufficiently improved. More preferably, it is 1/10 to 1/3.

In the form of FIG. 1 described above, it is also preferable that the ratio between the lower height and the upper height in the water separator is set to 1/30 to 1/1. If the height of the lower part is too lower than 1/30, the generated water accumulated in the lower part may flow into the upper part and the detection accuracy of the interface between the dehydrated solvent and the generated water may not be sufficiently improved. However, if the height of the lower part is too high, the device may become too large. More preferably, it is 1/10 to 1/2.

As described above, the water separator used in the method for producing a dehydration reaction product of the present invention esterifies and / or amidates alcohol and / or amine and (meth) acrylic acid in the presence of a dehydrating solvent. In a method for producing a dehydration reaction product comprising a dehydration reaction step and using a reaction vessel and a water separator as essential, byproduct water produced as a by-product is removed from the reaction system, and bumping in the reaction vessel is prevented. In addition, by improving and stabilizing the detection accuracy of the interface between the dehydrated solvent and the produced water, and by sufficiently suppressing the formation of gel-like substances, the occurrence of problems in the manufacturing process and various It has the effect of being able to sufficiently suppress the deterioration of the performance and quality of chemical products. Such a water separator is one of the preferred embodiments of the present invention.

In the present invention, the dehydration reaction product is also preferably used as a raw material for producing a polymer for cement additive. That is, it is preferable to use a polymer obtained from a dehydration reaction product produced using the production method of the present invention as a raw material for producing cement additives. Thereby, in manufacture of a cement additive, the fall of the performance and quality is suppressed, and it becomes possible to manufacture stably.

Next, as a method for producing a dehydration reaction product, a method comprising a neutralization step, a solvent distillation step, etc. as necessary following the dehydration reaction step will be described.
In the dehydration reaction step, for example, using a dehydration reaction apparatus that essentially includes a reaction tank, a condenser, and a connecting pipe for connecting the reaction tank and the condenser, and a water separator connected to the condenser and a supply pipe. Done. Using such a dehydration reaction apparatus, a distillation operation is performed using a condenser and a water separator while performing a dehydration reaction in a reaction vessel.

In the dehydration reaction step, when the dehydration reaction is in chemical equilibrium, the reaction proceeds when the reaction water generated by the reaction is removed from the reaction tank. In such a process, (1) in order to make it easy to remove the reaction product water generated in the reaction vessel, if necessary, a dehydrating solvent is mixed with the reaction solution, and the dehydrated solvent and the generated water are azeotropically vaporized. (2) an operation in which the distillate passes through a connecting pipe connecting the reaction vessel and the condenser and enters the condenser, and the distillate is condensed and liquefied in the condenser; (3 ) Operation to separate the condensed and liquefied distillate into dehydrated solvent and produced water in a water separator connected to the condenser, (4) Operation to recirculate the separated dehydrated solvent into the reaction tank, etc. Will be done.

The reaction vessel is used in the same meaning as the reactor, reaction vessel, reaction kettle and the like, and is not particularly limited as long as it is a vessel capable of performing a dehydration reaction. The shape of the reaction vessel is not particularly limited. Although there are a polygonal type and a cylindrical type, a cylindrical type is preferable from the viewpoints of stirring efficiency, handleability, and versatility. The presence or absence of a baffle plate does not matter. The reaction tank may be heated by bringing a heating medium such as steam into contact with the outer jacket, or it is equipped with a heat transfer device such as a coil inside the reaction tank for heating. Also good. The material inside such a reaction vessel is not particularly limited, and a known material can be used. For example, SUS304, SUS316, SUS316L, more preferably SUS316, made of SUS, preferably from the viewpoint of corrosion resistance. SUS316L etc. are mentioned. Moreover, it is good also as what is inactive with respect to a reaction raw material and a product by giving the glass lining process etc. inside the reaction tank. Such a reaction tank is usually equipped with a stirrer to perform a dehydration reaction uniformly and efficiently. The stirrer is not particularly limited. The stirrer is usually composed of an electric motor, a shaft, and a stirrer, but the stirrer may have any shape. As a stirrer, desk turbine, fan turbine, curved fan turbine, arrow blade turbine, multistage fan turbine blade, fowler blade, bull margin type, angled blade, propeller type, multistage blade, anchor type, gate type, double ribbon A blade, a screw blade, a Max blend blade, etc. can be mentioned. Among them, a multistage fan turbine blade and a Faudler blade are preferable from the viewpoint of versatility.

The condenser is a device that condensates and distills the distillate generated from the reaction tank, and the condensation is performed by exchanging heat between the extra-fluid fluid that is the cooling liquid and the distillate.

As the material of the capacitor, known materials such as SUS304, SUS316, SUS316L, etc., carbon steel (CS), and the like can be used. In order to further reduce the occurrence of gel-like substances, a capacitor whose inner surface is mirror-finished or glass-lined can be used. However, from the viewpoint of processing and maintenance costs, SUS304, SUS316, SUS316L, preferably SUS316, SUS316L. It is preferable to use a SUS capacitor such as

The heat transfer area of the capacitor varies depending on the volume of the reaction tank, but is preferably 50 to 500 m ^{2 in the} reaction tank 30 m ³ , for example. More preferably 100 to 200 m ^2. Examples of the cooling medium used in such a condenser include water and oil.

The volume of the water separator, varies depending distillate amount of the volume or distillate of the reaction vessel, for example, the reaction vessel 30 m ^3, it is preferable to 1-20 m ^3. More preferably, it is ³ to 10 m ³ .

The dehydration reaction step is a step of esterifying and / or amidating alcohol and / or amine and (meth) acrylic acid in the presence of a dehydrating solvent, thereby producing an ester and / or amide. . The compounds used as reaction raw materials in such steps may be used alone or in combination of two or more. In the present specification, the above esters and amides are also referred to as esterified products and amidated products, respectively.

The alcohol used in the esterification reaction is not particularly limited as long as it is a compound having a hydroxyl group, and examples thereof include alcohols, phenols, diols, trivalent or higher alcohols, and polyols. For example, alcohols include methanol, ethanol, n-propanol, n-butanol, 2-ethylbutanol, n-octanol, 1-dodecanol, 1-octadecanol, 2-ethylhexanol, cyclohexanol, allyl alcohol, 3 Primary alcohols such as methyl-3-buten-1-ol; iso-propyl alcohol, 2-butanol, 2-pentanol, 3-pentanol, 2-heptanol, 3-heptanol, methylamyl alcohol, 2-octanol Secondary alcohols such as nonyl alcohol and alcohols having 12 to 14 carbon atoms such as “Softanol (trade name)” manufactured by Nippon Shokubai Co., Ltd .; tertiary alcohols such as tert-butanol and tert-pentanol; For example, phenol, And diols include monoethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, monopropylene glycol, dipropylene glycol, polyethylene, and the like. Polypropylene glycol, diethanolamine, N-butyldiethanolamine and the like, and trivalent or higher alcohols and polyols include glycerin, trimethylolpropane, 1,3,5-pentanetriol, pentaerythritol, glucose, fructose, sorbitol, Examples thereof include gluconic acid, tartaric acid, polyvinyl alcohol and the like.

The alcohol preferably contains a compound represented by the following general formula (1), and such a compound is preferably contained as a main component in the alcohol. In this case, the alcohol may or may not contain other components.

R ¹ (R ² O) nH (1)
In formula (1), R ¹ represents a hydrocarbon group having 1 to 30 carbon atoms. R ² O is the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms, preferably 2 to 8 carbon atoms. n represents the average addition mole number of the oxyalkylene group represented by R ² O, and is a number of 0 to 300, preferably 2 to 300.
That is, in a preferred embodiment of the present invention, the alcohol is represented by the following general formula (1);
R ¹ O (R ² O) nH (1)
(In the formula, R ¹ represents a hydrocarbon group having 1 to 30 carbon atoms. R ² O is the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms. N represents R ² O. Represents the average number of added moles of the oxyalkylene group, and is a number of 0 to 300.).
The average added mole number means an average value of the number of moles of the repeating unit in 1 mole of the compound.

When the carbon number of R ¹ exceeds 30 or the carbon number of R ² O exceeds 18, the water-solubility of the polymer obtained from the esterified product as a raw material for production decreases, and is used for cement additives, etc. There is a risk that the application performance of the resin, that is, the cement dispersion performance, etc., may be reduced. On the other hand, when n exceeds 300, the reactivity between the compound represented by the general formula (1) and (meth) acrylic acid may be lowered.

The range of the suitable carbon number of R ¹ or R ² O is set depending on the intended use of the esterified product. For example, when an esterified product is used as a raw material for producing a polymer for a cement additive, R ¹ may be, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, or a tert-butyl group. , Pentyl group, hexyl group, octyl group, nonyl group, 2-ethylhexyl group, decyl group, dodecyl group, undecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group And alkyl groups such as heneicosyl group and docosyl group; aryl groups such as phenyl group; alkylphenyl groups such as benzyl group and nonylphenyl group; cycloalkyl groups such as cyclohexyl group; alkenyl group; alkynyl group and the like. Among these, it is preferable to set it as a C1-C18 linear or branched alkyl group and aryl group. More preferably, they are a methyl group, an ethyl group, a propyl group, a butyl group, and a phenyl group.

Examples of R ² O include an oxyethylene group, an oxypropylene group, an oxybutylene group, and an oxystyrene group. Among these, an oxyethylene group, an oxypropylene group, and an oxybutylene group are preferable. R ² O is a repeating unit constituting the compound represented by the general formula (1), and each repeating unit may be the same or different. Among these, in the case of having two or more different repeating units, each repeating unit may be added in a block shape or may be added in a random shape, and is not particularly limited.

The range of n is also set depending on the intended use of the esterified product. For example, when the esterified product is used as a raw material for producing a polymer for a cement additive, it is preferably 2 to 300. More preferably, it is 5-200, More preferably, it is 8-150. Moreover, when using as a thickener etc., it is preferable to set it as 10-250. More preferably, it is 50-200.

When n is 0, R ¹ is preferably a hydrocarbon group having 4 or more carbon atoms from the viewpoint of solubility in water and boiling point. That is, when n is 0, alcohol such as methanol or ethanol has a low boiling point, and therefore, it evaporates with the produced water and dissolves in the produced water, whereby a part of the alcohol raw material is distilled out of the reaction system, This is because the yield of the target esterified product is lowered, and this is prevented.

The amine used in the amidation reaction is not particularly limited. For example, ammonia; aliphatic primary amines such as methylamine, ethylamine, propylamine, butylamine, dodecylamine, cetylamine; dimethylamine, diethylamine, dipropyl Aliphatic secondary amines such as amine and diamylamine; aliphatic tertiary amines such as trimethylamine, triethylamine, tripropylamine and tributylamine; aliphatic unsaturated amines such as allylamine and diallylamine; cyclopropylamine, cyclobutylamine, Alicyclic amines such as cyclohexylamine; aromatic monoamines such as aniline, monomethylaniline, dimethylaniline and diphenylaniline; aromatic diamines such as o-phenylenediamine and m-phenylenediamine; Aminonaphthalines such as naphthylamine and β-naphthylamine; polyalkylenepolyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, dipropylenetriamine, tripropylenetetramine, tetrapropylenepentamine; monoethanolamine, Oxyethylene amines such as diethanolamine, polyethylene glycol (mono) amine, polyethylene glycol (di) amine; ureas such as urea and thiourea; polyethyleneimine, ethylene oxide adducts to polyethyleneimine, propylene oxide additions to polyethyleneimine And high polymers such as products.

In the esterification reaction or amidation reaction, an unsaturated monomer having another carboxyl group can be used together with (meth) acrylic acid. The unsaturated monomer having a carboxyl group is a monomer having at least a carboxyl group and an unsaturated bond. Specifically, unsaturated monocarboxylic acids such as crotonic acid, tiglic acid, citronellic acid, undecylenic acid, elaidic acid, erucic acid, sorbic acid, linoleic acid; maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid And the like, and the like. These may be used alone or in combination of two or more.

In the esterification reaction or amidation reaction, a catalyst may be added to the reaction system as necessary, and the reaction is preferably performed in the presence of the catalyst. In particular, an acid catalyst is suitable for the esterification reaction, and the reaction can proceed rapidly. Such an acid catalyst may be used in the form of a hydrate and / or an aqueous solution. For example, sulfuric acid, methanesulfonic acid, paratoluenesulfonic acid, paratoluenesulfonic acid hydrate, xylenesulfonic acid, xylenesulfone Acid hydrate, naphthalene sulfonic acid, naphthalene sulfonic acid hydrate, trifluoromethane sulfonic acid, “Nafion (trade name, manufactured by DuPont)” resin, “Amberlyst 15 (trade name)” resin, phosphotungstic acid, phosphotungsten An acid hydrate, hydrochloric acid, etc. are mentioned. These may be used alone or in combination of two or more.

Among the above acid catalysts, those having a high boiling point at normal pressure (1013 hPa) in terms of the azeotropic temperature and reaction temperature of the dehydrating solvent and water described later, specifically, the boiling point at normal pressure is 150 ° C. or higher. Some are preferred. More preferably, it is 200 ° C. or higher. Examples of such an acid catalyst include sulfuric acid (boiling point at normal pressure: 317 ° C.), paratoluenesulfonic acid (boiling point: 185 to 187 ° C./13.3 Pa (0.1 mmHg)), paratoluenesulfonic acid hydrate. And methanesulfonic acid (boiling point: 167 ° C./1333.2 Pa (10 mmHg)). Among these, it is preferable to use paratoluenesulfonic acid and paratoluenesulfonic acid hydrate.

The amount of the acid catalyst used is not particularly limited as long as a desired catalytic action can be effectively expressed. For example, it is preferably 0.4 meq / g or less. If it exceeds 0.4 meq / g, the amount of diester formed in the reaction system during the esterification reaction will increase, and the cement dispersibility of the polymer for cement additives synthesized using these may decrease. There is. More preferably, it is 0.36-0.01 meq / g, More preferably, it is 0.32-0.05 meq / g. In addition, the usage-amount (milli equivalent / g) of an acid catalyst is represented by the value which divided the equivalent number (milli equivalent) of H ⁺ of the acid catalyst used for reaction by the total preparation amount (g) of the reaction raw material. Specifically, it means a value calculated by the following equation.

The amount of the acid catalyst used is also the usefulness of esterified products and amidated products used as raw materials for producing polymers applied to various chemical products, and the basic performance required for such applications. From the viewpoint of preventing or suppressing the generation of gel-like substances that adversely affect performance, etc., the ratio of the weight of the acid in the acid catalyst to the total weight of the reaction raw material is X (wt%), and hydration in the acid catalyst 0 <Y <1.81X-1.62, where Y (% by weight) is the weight ratio of water present as a product and / or aqueous solution.
It is preferable that the following relational expression is satisfied.

The above relational expression will be described with a specific example. For example, taking paratoluenesulfonic acid monohydrate as an example, the ratio of the weight of paratoluenesulfonic acid to the total weight of the reaction raw materials is X (wt%). Yes, the ratio of the weight of water present as a monohydrate to the total weight of the reaction raw material is Y (% by weight), and never as an acid component other than the acid catalyst, for example, (meth) acrylic of the raw material Acids and moisture, that is, reaction product water generated by the esterification reaction, cannot be the above X and Y objects.

In the case where the amount of the acid catalyst used does not satisfy the above relational expression, for example, when Y is 0, there is no moisture present as a hydrate and / or an aqueous solution in the acid catalyst. Occasionally, the amount of gel formed in the reaction system increases, and there is a risk that, for example, cement dispersibility may be reduced as the performance of the polymer for cement additive synthesized using them. If Y ≧ 1.81X−1.62, the amount of gel formed in the reaction system during the esterification reaction increases, and the same as above.
The acid catalyst may be added to the reaction system all at once, continuously or sequentially, but from the viewpoint of workability, it is preferable to charge the reaction tank together with the reaction raw materials.

The esterification reaction or amidation reaction is preferably performed in the presence of a polymerization inhibitor. Thereby, polymerization of the unsaturated carboxylic acid in the reaction raw material and the esterified product and / or amidated product thereof can be prevented. As such a polymerization inhibitor, a known polymerization inhibitor can be used, and is not particularly limited. For example, phenothiazine, tri-p-nitrophenylmethyl, di-p-fluorophenylamine, diphenylpicrylhydrazyl, N -(3-N-oxyanilino-1,3-dimethylbutylidene) aniline oxide, benzoquinone, hydroquinone, methoquinone, butylcatechol, nitrosobenzene, picric acid, dithiobenzoyl disulfide, cuperone, copper (II) chloride and the like. These may be used alone or in combination of two or more. Among these, phenothiazine, hydroquinone, and methoquinone are preferably used from the viewpoint of solubility. These are extremely useful in that they can exhibit the polymerization inhibiting ability very effectively both in the dehydration reaction step and in the solvent distillation step.

As the usage-amount of the said polymerization inhibitor, when the total preparation amount of the alcohol, amine, and acid which are reaction raw materials shall be 100 weight%, it is preferable to set it as 0.001-1 weight%. If it is less than 0.001% by weight, the ability to inhibit polymerization is not sufficiently exhibited, and it is difficult to effectively prevent polymerization of reaction raw materials and products, and if it exceeds 1% by weight, polymerization remaining in the esterified product is prohibited. Since the amount of the agent increases, the quality and performance may be deteriorated, and an effect commensurate with the excessive addition may not be obtained, which may be disadvantageous from an economical viewpoint. More preferably, it is 0.001 to 0.1 weight%.

In the above esterification or amidation reaction, by performing a dehydration reaction in the presence of a dehydrating solvent, the generated water and the dehydrated solvent are azeotroped outside the reaction system, and the product water is separated and removed by condensing into liquid. This can be done by refluxing. Thereby, the reaction product water produced | generated by esterification reaction or amidation reaction can be azeotroped efficiently. Such a dehydrating solvent is not particularly limited as long as it is an azeotropic solvent with water, and examples thereof include benzene, toluene, xylene, cyclohexane, dioxane, pentane, hexane, heptane, chlorobenzene, and isopropyl ether. These may be used alone or in combination of two or more. Among these, those having an azeotropic temperature with water of 150 ° C. or lower are preferable, and those having an azeotropic temperature of 60 to 90 ° C. are more preferable. Specific examples of such a dehydrating solvent include cyclohexane, toluene, dioxane, benzene, isopropyl ether, hexane, heptane, and the like. When the azeotropic temperature with water exceeds 150 ° C., handling properties including temperature control in the reaction system during the reaction and control such as a condensate liquefaction treatment of the distillate may be deteriorated.

In the dehydration reaction operation using the dehydrating solvent, the amount of the dehydrating solvent used is preferably 0 to 100% by weight when the total amount of alcohol, amine and acid as reaction raw materials is 100% by weight. If it exceeds 100% by weight, an effect commensurate with the excessive addition cannot be obtained, and a large amount of heat is required to keep the reaction temperature constant, which may be disadvantageous from an economical viewpoint. More preferably, it is 2 to 50% by weight.

In the dehydration reaction step, the esterification reaction and the amidation reaction can be carried out by either a batch or continuous reaction operation method, but it is preferably carried out in a batch manner. Moreover, it does not specifically limit as reaction conditions, What is necessary is just the conditions which reaction advances smoothly, For example, as reaction temperature, it is preferable to set it as 30-180 degreeC. More preferably, it is 60-130 degreeC, More preferably, it is 90-125 degreeC, Most preferably, it is 100-120 degreeC. When the temperature is lower than 30 ° C, the reflux of the dehydrating solvent is slowed down, and it takes time for dehydration, and the reaction may not easily proceed. In polymers obtained by chemicals and amidated products, the dispersion performance and viscosity increase characteristics in various applications such as cement dispersion performance, polymerization of reaction raw materials, increase in the amount of reaction raw materials mixed in the distillate, There is a risk of degradation of performance and quality of the amidated product.

In the above reaction conditions, the reaction time is preferably set until the reaction rate reaches 70% or more as described later. More preferably, it reaches 80% or more, and even more preferably, it reaches 98% or more. Usually, it is 1 to 100 hours, preferably 3 to 60 hours. In addition, the reaction pressure may be performed under normal pressure or reduced pressure, but it is preferably performed under normal pressure from the viewpoint of equipment.

The reaction rate of the esterification reaction or amidation reaction is preferably set to 70% or more. If it is less than 70%, the yield of the ester or amide produced is insufficient, and there is a risk that the application performance of the polymer for cement additive obtained using this as a polymerization raw material, that is, the cement dispersibility, etc. may be lowered. is there. More preferably, it is 70-99%, More preferably, it is 80-98%. The above reaction rate is the ratio of the amount of alcohol or amine that is a reaction raw material when charged and the amount at the end of the reaction. For example, it is measured as the area of each peak by liquid chromatography (LC) under the following measurement conditions. By doing so, it is a value (%) calculated by the following formula.

Reaction rate measurement condition analyzer: Millensium Chromatography Manager (trade name) manufactured by Waters
Detector: 410 RI detector manufactured by Waters (trade name)
Column used: Inert Sil ODS-2 (inner diameter 4.6 mm, length 250 mm) (trade name) manufactured by GL Sciences Inc. Column temperature: 40 ° C.
Eluent: 8946 g of water, 6000 g of acetonitrile and 54 g of acetic acid are mixed, and a solution adjusted to pH 4.0 with 30% aqueous sodium hydroxide solution is used.
Flow rate: 0.6 ml / min

In the method for producing a dehydration reaction product of the present invention, when an acid catalyst is used in the dehydration reaction step, it is preferable to perform a neutralization step of neutralizing the acid catalyst or (meth) acrylic acid. As a result, the catalyst loses its activity, the hydrolysis of the dehydration reaction product obtained by the esterification reaction or amidation reaction is suppressed, and the generation of impurities not involved in the polymerization is suppressed. It is possible to suppress the decrease.

As the method of the neutralization step, for example, a method of neutralizing the acid catalyst with a neutralizing agent after completion of the esterification reaction or amidation reaction is preferable.
The neutralizing agent is not particularly limited as long as it can neutralize the acid catalyst. For example, alkali metal such as sodium hydroxide, potassium hydroxide, calcium hydroxide and lithium hydroxide, hydroxide of alkaline earth metal; alkali metal such as sodium carbonate, calcium carbonate and lithium carbonate, carbonate of alkaline earth metal Salts: Amines such as ammonia, monoethanolamine, diethanolamine, triethanolamine and the like can be mentioned, and one or more of these are used. Moreover, it does not specifically limit as a form of a neutralizing agent, For example, it is preferable to set it as the form of alkaline aqueous solution.

In the neutralization step, the acid catalyst and (meth) acrylic acid are neutralized, but it is preferable to set so that all of the acid catalyst and part of (meth) acrylic acid are neutralized. . In this case, the (meth) acrylic acid to be neutralized is 20% by weight or less, preferably 0.01 to 5 when the remaining (meth) acrylic acid after the esterification reaction or amidation reaction is 100% by weight. It is preferable that it is weight%. It should be noted that the acid catalyst and (meth) acrylic acid are neutralized from the acid catalyst because the acid catalyst has higher acid strength.

In the neutralization method in the neutralization step, when an esterification reaction or an amidation reaction is performed in a dehydrating solvent, it is preferable to add a large amount of water together with an alkali to the reaction system. In other words, in the absence of a large amount of water, the alkali is hardly soluble in the dehydrating solvent, so it floats in the system in a concentrated state, and such a high concentration of alkali floats for a long time until it is consumed for neutralization. It does not disappear and causes hydrolysis of esterified products and amidated products. In this case, the amount of water added depends on the form of alkali used. For example, when 40 to 60% by weight of an alkaline aqueous solution is added as a neutralizing agent, the alkaline aqueous solution 1 is added separately from the alkaline aqueous solution. Usually, it is preferably 5 to 1000 parts by weight with respect to parts by weight. More preferably, it is 10 to 100 parts by weight. If the amount is less than 5 parts by weight, the alkali may become non-uniform in the reaction system. If the amount exceeds 1000 parts by weight, the production cost increases, such as a separate neutralization tank is required to ensure productivity. There is a risk.

For example, the neutralization temperature in the neutralization step is preferably 90 ° C. or lower. More preferably, it is 0-80 degreeC. More preferably, it is 25-65 degreeC. When it exceeds 90 ° C., the added neutralizing agent acts as a catalyst for hydrolysis, and there is a possibility that a large amount of hydrolysis products may be generated. When the temperature is 80 ° C. or lower, the formation of hydrolysis products is more sufficiently suppressed. However, when the temperature is lower than 0 ° C., the reaction solution becomes viscous, which makes stirring difficult. In order to distill off water after the reaction, it takes a long time to lower the temperature to a predetermined temperature, or it is necessary to install cooling means (equipment) to lower the temperature to a temperature lower than room temperature. Cost may increase.

Except for the case where the dehydrated solvent is used in the polymerization step or the like, the dehydrated solvent is preferably distilled off. In the solvent distillation step, the method for distilling off the dehydrated solvent is not particularly limited. For example, the solvent may be distilled off by distilling only the dehydrated solvent, or may be distilled off by adding other appropriate additives. However, it is preferable to azeotropically distill off with a dehydrating solvent using water. In this case, since the neutralization step is performed, there is substantially no acid catalyst or alkali in the reaction system. Therefore, the hydrolysis reaction does not occur even if the temperature is increased by adding water. By such a method, the dehydrated solvent can be removed at a lower temperature.

The conditions for the distillation method are not particularly limited as long as the dehydrating solvent in the reaction system is suitably distilled (evaporated). For example, the liquid temperature in the reaction vessel during solvent distillation (under normal pressure) ), When water is used, it is usually preferably 80 to 120 ° C. More preferably, it is 90-110 degreeC. Moreover, when not using water, it is preferable to set it as 80-160 degreeC normally. More preferably, it is 90-150 degreeC. In any of the above cases, if the temperature is lower than the above temperature, there is a possibility that the temperature (calorie) sufficient to evaporate the dehydrated solvent may not be obtained. If the temperature is higher than the above temperature, polymerization may be caused. A large amount of heat may be consumed for evaporation of a large amount of low-boiling-point raw materials. The pressure in the reaction vessel may be under normal pressure or under reduced pressure, but it is preferably from the equipment side under normal pressure.
As the apparatus system used in the solvent distillation process, it is preferable to use the apparatus system used in the dehydration reaction process as it is.

The dehydration reaction product obtained by the method for producing a dehydration reaction product of the present invention includes various polymers, that is, pigment additives such as cement additives, calcium carbonate, carbon black, ink, scale inhibitors, gypsum / water slurry. It is suitably applied as a production raw material for producing a polymer used in chemical products such as a dispersant for coal, a dispersant for coal / water slurry (CWM), and a thickener.

In the following, a method for producing a polymer for cement dispersant using a dehydration reaction product obtained by the method for producing a dehydration reaction product as a production raw material, and a method for producing a cement additive containing the polymer for cement dispersant A method of using the cement additive will be described.

Examples of the polymer for cement dispersant include a polycarboxylic acid polymer obtained by polymerizing a monomer having the obtained dehydration reaction product and an unsaturated carboxylic acid monomer as essential components. There is no restriction | limiting in particular as a polymerization method of such a polycarboxylic acid type polymer, For example, well-known polymerization methods, such as solution polymerization using a polymerization initiator, and block polymerization, are employable.

Examples of the unsaturated carboxylic acid-based monomer include unsaturated monocarboxylic acids such as (meth) acrylic acid, crotonic acid, tiglic acid, citronellic acid, undecylenic acid, elaidic acid, erucic acid, sorbic acid, and linoleic acid; Unsaturated dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid; monoesters of these dicarboxylic acids and alcohols, etc., and monovalent metal salts, divalent metal salts thereof, Examples thereof include ammonium salts and organic amine salts.

The polycarboxylic acid polymer may be copolymerized with a monomer other than the unsaturated carboxylic acid monomer, if necessary. Examples of such monomers include unsaturated amides such as (meth) acrylamide and (meth) acrylalkylamide; vinyl esters such as vinyl acetate and vinyl propionate; vinyl sulfonic acid, (meth) allyl sulfonic acid, Unsaturated sulfonic acids such as sulfoethyl (meth) acrylate, 2-methylpropanesulfonic acid (meth) acrylamide, and styrene sulfonic acid, and their monovalent metal salts, divalent metal salts, aluminum salts, organic amine salts; styrene, α- Aromatic vinyls such as methylstyrene; esters of (meth) acrylic acid with an alcohol having a phenyl group such as an aliphatic alcohol or benzyl alcohol having 1 to 18, preferably 1 to 15 carbon atoms; polyalkylene glycol mono ( (Meth) acrylate; polyalkylene glycol mono (meth) allyl Ether and the like.

The polycarboxylic acid polymer is preferably a polymer having a specific weight average molecular weight. For example, the weight average molecular weight in terms of polyethylene glycol by gel permeation chromatography (hereinafter referred to as “GPC”) under the following measurement conditions is preferably, for example, 500 to 500,000. If it is less than 500, the water reducing performance of the cement additive may be lowered, and if it exceeds 500,000, the water reducing performance and slump loss preventing ability of the cement additive may be lowered. More preferably, it is 5000-300000, Most preferably, it is the range of 8000-100,000.

The GPC includes an eluent storage tank, an eluent liquid feeder, an autosampler, a column oven, a column, a detector, a data processor, and the like. For example, the molecular weight can be measured by setting measurement conditions by combining the following commercially available apparatuses.

Molecular weight measurement condition model: LC module 1plus (trade name, manufactured by WATERS)
Detector: differential refractometer (RI) 410 differential refractometer (trade name, manufactured by WATERS)
Eluent: 0.05M sodium acetate, acetonitrile / ion-exchanged water = 40/60 mixture whose pH is adjusted to 6 with acetic acid is used.
Eluent flow rate: 1.0 ml / min
column:
TSK-GEL guard column (inner diameter 6mm, length 40mm)
+ TSK-GEL G-4000SWXL (inner diameter 7.8 mm, length 300 mm) + TSK-GEL G-3000SWXL (inner diameter 7.8 mm, length 300 mm) + TSK-GEL G-2000SWXL (inner diameter 7.8 mm, length 300 mm) Also product name, manufactured by Tosoh Corporation)
Column oven temperature: 40 ° C

Calibration curve: The calibration curve varies depending on the molecular weight and number of standard samples, how to draw a baseline, the method of preparing a calibration curve approximation formula, and the like. For this reason, it is preferable to set the following conditions.
1. Standard samples Commercially available standard polyethylene oxide (PEO) and standard polyethylene glycol (PEG) are used as standard samples. It is preferable to use a standard sample having the following molecular weight.
1470, 4250, 7100, 12600, 24000, 46000, 85000, 219300, 272500 (9 points in total)
These standard samples were selected in consideration of the following points.
(1) Use 7 or more standard samples having a molecular weight of 900 or more.
(2) At least one standard sample having a molecular weight of 900 to 2000 is included.
(3) At least three standard samples having a molecular weight of 2000 to 60000 are included.
(4) At least one standard sample having a molecular weight of 200,000 ± 30000 is included.
(5) At least one standard sample having a molecular weight of 270000 ± 30000 is included.

2. How to draw a base line Upper limit of molecular weight: A point where a peak rises from a horizontal and stable baseline.
Lower limit of molecular weight: The point where the detection of the main peak is completed.
3. Approximation formula of calibration curve A calibration curve ("elution time" vs. "log molecular weight") prepared using the above standard sample is prepared as an approximate expression of a cubic equation and used for calculation.

The cement dispersant containing the above-mentioned polycarboxylic acid polymer can exhibit good cement dispersion performance and slump retention performance, but if necessary, known cement additives (cement other than polycarboxylic acid polymer) A dispersant may be further blended.

In the above cement dispersant, air entraining agent, cement wetting agent, swelling agent, waterproofing agent, retarder, quick setting agent, water-soluble polymer substance, thickener, flocculant, drying shrinkage reducing agent, strength enhancer, A hardening accelerator, an antifoamer, etc. can be mix | blended.
The cement dispersant obtained in this way is a cement composition containing cement and water, such as, for example, hydraulic cement such as Portland cement, high belite cement, alumina cement, various mixed cements, and cement such as gypsum. It will be used for other hydraulic materials.

As the addition amount of the cement dispersant to the hydraulic material, an excellent effect is exhibited even when added in a small amount as compared with conventional cement dispersants. For example, mortar or concrete using hydraulic cement, etc. When the weight of cement is 100% by weight, a ratio of 0.001 to 5% by weight may be added at the time of mixing. If the amount is less than 0.001% by weight, the effect of the cement dispersant may not be sufficiently exhibited. If the amount exceeds 5% by weight, the effect substantially reaches its peak, which is disadvantageous in terms of economy. There is a fear. More preferably, it is 0.01 to 1 weight%. As a result, various effects such as achievement of a high water reduction rate, improvement in slump loss prevention performance, reduction in unit water volume, increase in strength, and improvement in durability are exhibited.

The method for producing a dehydration reaction product of the present invention will be described with reference to FIG. 2 showing a schematic diagram of one embodiment of the apparatus configuration. Such an embodiment is a typical example of the present invention, and the embodiment of the present invention is not limited to this.

In FIG. 2, the temperature is first raised to a predetermined temperature to perform a dehydration reaction step, then the temperature is lowered to a predetermined temperature to perform a neutralization step, and then the temperature is raised to a predetermined temperature to perform a dehydrating solvent evaporating step. The device configuration is shown. In such an apparatus configuration, the distillate containing the reaction product water generated during the dehydration reaction is distilled in the reaction tank 101, and after condensing and liquefying in the condenser 125 while preventing the generation of gelled substances, A circulation mechanism is formed in which the reaction product water is separated and removed by the separator 127, and the remaining distillate is refluxed by the pump 142 at a predetermined solvent circulation rate and returned to the reaction tank 101. In such a circulation mechanism, the upper part of the reaction tank 101 and the top of the vertical multi-tube type circular tube condenser 125 of the countercurrent or cocurrent contact type are connected by the connecting pipe 123, and the bottom bottom of the condenser 125 is separated from the water. The upper part of the vessel 127 is connected by a supply pipe (pipe) 129, whereby the reaction tank 101 and the water separator 127 are connected by the supply pipe 129.
Below, the case where an esterification reaction is performed as a dehydration reaction is demonstrated.

The reaction tank 101 is provided with an external jacket 102 that can use hot water, Kajo steam, or the like as a heat medium as a heat exchange means. In the reaction tank 101, temperature sensors (not shown) for measuring the reaction temperature are attached to several appropriate parts. Such a temperature sensor is electrically connected to a control unit main body (not shown) in order to keep the reaction temperature at a specified temperature. Examples of the device mechanism include a jacket 102 attached to the reaction vessel 101.

The water separator 127 in the above embodiment is made of SUS304, and a baffle plate 131 is provided in the interior, and two chambers (A) 133 and a chamber (B) 134 separated by the baffle plate 131 are formed. Has been. In this water separator 127, the supply pipe 129 has an opening in the liquid phase part of the chamber (A) 133 and also has an opening in the gas phase part by a plurality of holes 162 formed in the side surface of the supply pipe 129. And the opening of the gas phase portion is in the direction opposite to the baffle plate 131. In FIG. 2, the arrow inside the water separator 127 indicates the flow direction of the distillate from the open port, and a plurality of holes 162 of the supply pipe 129 are shown in an enlarged view. Further, the lower diameter of the water separator 127 is smaller than the upper diameter. Further, an interface meter (A) 136 is provided as a detection device for the interface between the dehydrated solvent and the produced water, and an interface meter (B) 138 is provided as a device for detecting the gas-liquid interface between the gas phase portion and the liquid phase portion (dehydrated solvent). The antigelling agent is allowed to act on the inside of the interface meter (A) 136 and the interface meter (B) 138.

The water separator also has a condenser 128 attached to the gas phase. Since the dehydrated solvent, volatile (meth) acrylic acid, and the like in the gas phase portion of the water separator are sufficiently cooled by the condenser 128, they are not released out of the system. Further, the condenser 128 is provided with an open port (so-called vent), so that even when the reaction tank is heated, the pressure in the reaction system does not increase excessively, and the instrument is prevented from being damaged.

In the water separator 127, the lower part of the chamber (A) 133 on the side where the distillate condensed by the condenser 125 is stored is connected to the generated water treatment tank 135 by a pipe 137, and the pipe 137 has a control. A valve 140 is provided, and a wastewater pipe 139 is connected to the processing tank 135. The lower part of the other chamber (B) 134 of the water separator 127 is connected to the reaction tank 101 by a pipe 141, and this pipe 141 is also provided with a control valve (not shown), and the generated water in the reaction tank 101 A pipe 145 connected to a dehydrated solvent storage tank 143 for storing the azeotropic dehydrated solvent is joined (connected). A circulation pump 142 is installed on the path of the pipe 141 before the junction (water separator 127 side), and a flow meter 144 is installed on the path of the pipe 141 behind the junction (on the reaction tank 101 side). Is provided. Further, the flow meter 144 is electrically connected to a flow rate measurement system main body (not shown) for integrating the measured flow rate and calculating the solvent circulation rate.

The reaction tank 101 includes a raw material storage tank 103 made of stainless steel (for example, SUS304) for alcohol raw material, a raw material storage tank 105 for (meth) acrylic acid raw material, a catalyst storage tank 107 for acid catalyst, and dehydration A neutralizing agent storage tank 111 made of carbon steel (for example, high carbon steel) storing a neutralizing agent (neutralizing agent aqueous solution) for neutralizing the acid catalyst after the reaction is provided, and pipes 113 and 115, respectively. 117 and 121 are connected. The pipe 117 is provided with a pump 167. Further, a polymerization inhibitor storage tank 109 storing a polymerization inhibitor for preventing polymerization in the reaction system (reaction tank 101) during the dehydration reaction is connected via a pump 169 via a pipe 119.

In the raw material storage tank 105, (meth) acrylic acid is easily polymerized. For example, methacrylic acid is polymerized by long-term storage, heat, or the like. Is added to (meth) acrylic acid. In FIG. 2, a circulation path 151 having an external jacket 150 (thermal insulation means) using a pump 116 is provided to keep the temperature constant at 30 to 40 ° C., and the (meth) acrylic acid raw material is always kept at 30 to 40 ° C. The apparatus configuration is such that it is held and circulated so as not to polymerize.

The raw material storage tank 105, the pipe 115, the pump 116, and the circulation path 151 are subjected to lining processing with a corrosion-resistant material such as synthetic resin in order to prevent corrosion due to corrosive (meth) acrylic acid. Is preferably used. Similarly, the catalyst storage tank 107, the piping 117, and the pump 167 are also subjected to lining processing using acid-resistant materials such as Teflon (registered trademark) and synthetic resin such as vinyl chloride in order to prevent corrosion by the acid catalyst. It is preferable to use a magnet pump as the pump 167. The polymerization inhibitor storage tank 169 and the anti-gelation agent storage tanks 147 and 159 are each provided with a stirring device (not shown). In the case where the powdery polymerization inhibitor is dissolved in a solvent, it is preferable that the powdery polymerization inhibitor is sufficiently stirred and completely dissolved. However, if a solution of a polymerization inhibitor or an antigelling agent that is not completely dissolved for some reason is transferred by the pumps 160, 169, and 179, the pump may become blocked and stop. Such a situation cannot occur as long as dissolution is sufficient, but pumps 160, 169, and 179 are preferably pumps that can continue the transfer without delay even if a small amount of slurry liquid is transferred. When transferring a polymerization inhibitor or an anti-gelling agent dissolved in a solvent, it is preferable to use a pump sealed with a chemical resistant material such as Teflon (registered trademark) or Viton (registered trademark). As a pump that satisfies such conditions, it is optimal to provide an appropriate seal to the MONO pump (manufactured by Hyojin Equipment Co., Ltd.). Further, a pipe 153 for recovering the esterified product synthesized in the reaction tank 101 by the esterification reaction is connected to the lower part of the reaction tank 101.

In FIG. 2, a spray nozzle 126 is provided at the top of the condenser 125 in order to suppress the generation of gel-like substances in the condenser 125. The spray nozzle 126 is used for preventing gelation of distillate. The antigelling agent storage tank 147 for storing the antigelling agent is connected to the piping 149 via a pump 179. Similarly, a spray nozzle (not shown) is provided in the vicinity of the connection portion between the reaction tank 101 and the connecting pipe 123 so as to spray from the connecting pipe 123 side toward the reaction tank 101 side. The water separator 127 and the pipe 141 are connected.

Part of the circulation mechanism is to distill distillate containing dehydrated solvent from the solution containing esterified product, which is a product in the system (inside reaction tank 101), after the dehydration reaction, thereby preventing the generation of gel-like substances. While being condensed and liquefied, it is also used as a circulation mechanism for removing distillate containing a dehydrated solvent out of the system. In such a circulation mechanism, a vacuum pump (ejector) 155 is attached to the water separator 127 in order to remove the dehydrated solvent by vacuum suction through a pipe 157. Further, in FIG. 2 above, an aqueous solution in which a water-soluble polymerization inhibitor is newly dissolved in the spray nozzle 126 newly provided at the top of the condenser 125 in order to sufficiently prevent gelation in the aqueous phase in the distillate. A water-soluble gelation inhibitor storage tank 159 for storing (hereinafter, also simply referred to as “water-soluble gelation inhibitor”) is connected by a pipe 161.

In FIG. 2 described above, the dehydration reaction product is produced by the above apparatus configuration as described below.
First, as a dehydration reaction step, pipes 113, 115, 117, and 119 are provided in the reaction tank 101 from the raw material storage tanks 103 and 105, the catalyst storage tank 107, the polymerization inhibitor storage tank 109, and the dehydration solvent storage tank 143. In addition, a predetermined amount of alcohol and (meth) acrylic acid, an acid catalyst, a polymerization inhibitor, and a dehydrating solvent as reaction raw materials are charged through a pipe 141 through a pipe 145, and appropriately set reaction temperature, jacket temperature, pressure, etc. The esterification reaction is performed under the following reaction conditions. As a result, the produced water successively produced is azeotroped with the dehydrated solvent charged in the reaction tank 101 and distilled through the connecting pipe 123. The gas fluid that has been distilled, that is, the distillate that is a solvent-water azeotrope, is passed through the condenser 125 to be condensed and liquefied. Further, in FIG. 2 described above, a predetermined amount of the antigelling agent is continuously sprayed from the spraying nozzle 126 provided at the top of the condenser 125 from the antigelling agent storage tank 147 through the pipe 149, and the gas fluid or condensation is sprayed. It is in contact with a distillate that is a liquefied product.

Next, the condensed and liquefied distillate is stored in the chamber (A) 133 of the water separator 127 through the supply pipe 129 from the lower part of the condenser 125, and is divided into two layers of an aqueous phase (lower phase) and a solvent phase (upper phase). Will be separated. At this time, since the opening of the supply pipe 129 is set as described above, even if the pressure of the distillate supplied to the water separator 127 fluctuates, the occurrence of bumping and the detection accuracy of the interface are improved. Problems such as lowering, liquid fluctuation at the interface, and formation of a gel-like substance are sufficiently suppressed. Further, the generated water of the lower phase is sequentially extracted through the pipe 137 and stored in the generated water treatment tank 135. At this time, the interface valve (A) 136 detects the interface between the aqueous phase and the solvent phase, and the control valve provided in the pipe 137 keeps the interface in the narrow portion below the water separator 127. It is controlled by adjusting the extraction amount (distillation amount) of the aqueous phase. Then, after being chemically or biologically treated so as to satisfy the environmental standard (waste water standard) value in the treatment tank 135 as necessary, the waste water is discharged outside the apparatus system through the pipe 139. On the other hand, in the chamber (A) 133, the upper solvent phase containing the gelation inhibitor sprayed from the nozzle 126 overflows the baffle plate 131 and is stored in the adjacent chamber (B) 134. Then, the solvent phase is refluxed at a predetermined solvent circulation speed through the pipe 141 via the pump 142 and returned to the reaction tank 101. At this time, the solvent circulation speed is adjusted by the control valve and the pump 142 provided in the pipe 141. In these operations, since the water separator 127 has the above-described structure, the effects of the present invention are fully exhibited, the occurrence of defects in the production process is suppressed, and the performance and quality of the esterified product to be produced are reduced. It is possible to sufficiently suppress the decrease. At this time, a part is sprayed through a spray nozzle provided in the vicinity of the connection between the reaction tank 101 and the connecting pipe 123 to prevent gelation in the vicinity of the connection between the reaction tank 101 and the connecting pipe 123.

Further, as a neutralization step, after completion of the dehydration reaction, the temperature is lowered and the internal temperature (liquid temperature) of the reaction vessel 101 is lowered through the refrigerant to the outer jacket 102 of the reaction vessel 101 until the temperature falls to, for example, 60 ° C. or lower. Add an alkaline aqueous solution (neutralizing agent) diluted to a predetermined concentration with a large amount of water into the reaction tank 101 from the neutralizing agent storage tank 111 through the pipe 121 while appropriately adjusting to maintain the temperature below a predetermined temperature. By doing so, a part of the acid catalyst or (meth) acrylic acid is partially neutralized.

After the neutralization step is completed, as the solvent distillation step, dehydration in the reaction vessel 101 is performed by heating the external jacket 102 of the reaction vessel 101 to a predetermined temperature through a heating medium (pressurized steam) under normal pressure. In addition to the solvent and water added during the partial neutralization treatment, (meth) acrylic acid and the like are azeotropically distilled through the connecting pipe 123. The solvent-water azeotrope, which is a gaseous fluid that has been distilled off, is passed through the condenser 125 to be condensed and liquefied.

The distillate condensed in the solvent distillation step is treated in the same manner as the distillate condensed in the dehydration reaction step, except that the distilled dehydrated solvent is not refluxed to the reaction vessel 101. Become.
In the solvent distillation step, a larger amount of water enters the condenser 125 together with the solvent than in the dehydration reaction step. In order to prevent the polymerizable compound from gelling on the aqueous phase side, a predetermined amount of water-soluble gelation is obtained from the water-soluble gelation inhibitor storage tank 159 through the pipe 161 through the spray nozzle 126 provided at the top of the condenser 125. It is preferable that the inhibitor is continuously dropped and brought into contact with the distillate.

After the solvent evaporating step, adjusted water is added to the reaction tank 101 from a water storage tank (not shown) or a water pipe (not shown) connected by a pipe (not shown). An aqueous solution of the dehydration reaction product is obtained. The resulting aqueous solution of the dehydration reaction product is recovered (stored) from the pipe 153.

Since the method for producing a dehydration reaction product of the present invention has the above-described configuration, it is possible to sufficiently suppress the occurrence of defects in the production process and the degradation of performance and quality of various chemical products. The resulting dehydration reaction product can be of high quality. Such dehydration reaction products include cement additives (cement dispersants), calcium carbonate, carbon black, pigment dispersants such as ink, scale inhibitors, gypsum / water slurry dispersants, coal / water slurry (CWM). It can be suitably used as a raw material for producing chemical products such as dispersants and thickeners.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples. “Part” means “part by weight” unless otherwise specified, and “%” means “% by weight”.

Example 1
A cylindrical reaction vessel with an external jacket equipped with a thermometer, a stirrer, a water separator, and a columnar reflux condenser (condenser) each was 12340 parts of methoxypoly (n = 10) ethylene glycol, 6000 parts of methacrylic acid, 381 parts of sulfuric acid. Then, 4 parts of phenothiazine and 5300 parts of cyclohexane were charged, and an esterification reaction was performed at a reaction temperature of 85 ° C.
The reaction vessel has an outer diameter of 3.6 m (including the thickness of the jacket), a height of 3.8 m, an internal volume of 30 m ³ , and an inner diameter of 0.2 m at a position 1.15 m from the center of the reaction vessel. The connection pipe can be connected. The condenser is a vertical multi-tube heat exchanger (fixed tube plate type) with an outer diameter of 0.9 m and a height of 4 m. The length is 3.5 m inside, the outer diameter is 24 mm, and the thickness is 2 mm. This structure has 624 heat transfer tubes and can spray the inhibitor solution on the top of the tower.

The water separator is a cylindrical tank, and as shown in FIG. 1, a supply pipe and a baffle plate are provided, interface meters (A) and (B) are provided, and the structure is composed of an upper part and a lower part. did. These materials were made of SUS304. The upper part was 2.6 m in height and the inner diameter was 2.2 m, and the lower part was 0.36 m in height and the inner diameter was 0.2 m. The baffle plate was a flat plate, and was installed at a position 0.55 m from the center of the cylinder so that the height from the bottom of the upper part was 2 m. Furthermore, the supply pipe is a circular pipe, the inner diameter is 25 mm, the position where the height from the bottom of the upper part is 0.4 m is the opening of the liquid phase part, and it becomes the interface between the gas phase part and the liquid phase part Four circular holes with a diameter of 13 mm (1/2 inch) were formed at equal intervals in the vertical direction in the opposite direction to the baffle plate at positions 30 to 100 mm above the position to provide an opening for the gas phase part. The interface meters (A) and (B) were provided with nozzles so that an antigelling agent could be injected.

Separately, 0.5 part of phenothiazine and 578 parts of cyclohexane were mixed in the dissolution tank, and the MONO pump (manufactured by Hyojin Equipment Co., Ltd.) was passed to the top of the condenser from the beginning of reflux of cyclohexane (internal temperature 82 ° C) to the end of the esterification reaction. Was sprayed from a spray nozzle. Moreover, cyclohexane was sprayed also from the spray nozzle also to the connection part of the reaction tank, and 1 part of phenothiazine was added to the interfacial meters (A) and (B) once every 5 times to prevent polymerization of methacrylic acid. It was confirmed that the esterification rate reached 99% in about 24 hours. The reaction rate was monitored from time to time with the total amount of reaction product water. During this reaction, the amount of reaction product water extracted was adjusted by a control valve so that the interface between cyclohexane and water was kept in the lower part of the water separator. Cyclohexane was refluxed from the water separator to the reaction vessel.

To the obtained esterification reaction solution, 967 parts of a 49% aqueous sodium hydroxide solution and 3800 parts of water were added at 50 ° C. or lower to neutralize a part of sulfuric acid and methacrylic acid. After neutralization, the temperature was raised to 98 ° C., and cyclohexane was distilled off azeotropically with water. During the distillation of cyclohexane, the gelation inhibitor solution in the dissolution tank was sprayed onto the top of the condenser tower. Further, steam was blown into the jacket of the connecting pipe from the upper part, and the drain and steam were extracted from two outlets (reaction tank side and condenser side) at the lower part to keep the temperature. Then, after cyclohexane was distilled off, cooling was performed to obtain an aqueous solution (M1) of the esterified product. The obtained aqueous solution (M1) was transferred to a separately provided container. The above operation was repeated 30 batches. During the 30 batch operations, the interface in the water separator was kept accurately and constant, and no bumping or the like was observed. Furthermore, there was no trouble due to gelation in the interface meter.

Comparative Example 1
As the water separator, an aqueous solution of an esterified product was obtained in the same manner as in Example 1 except that the supply pipe did not have an opening on the side surface but only an opening in the liquid phase part. The above operation was repeated 30 batches, but twice of which, bumping occurred in the reaction tank, and a part of the reaction solution reached the water separation pipe through the condenser. Therefore, the reaction solution and the dehydrated solvent (cyclohexane) in the water separation tube were discarded, the dehydration reaction process was stopped, and the connecting tube, the condenser, and the water separation tube were washed.

Comparative Example 2
An aqueous solution of an esterified product was obtained in the same manner as in Example 1 except that the initial setting amount of the interface of the water separator was incorrect and the interface became the upper part of the water separator. During the dehydration reaction process, the amount of reaction product water could not be accurately monitored, and it was not known whether the reaction rate target was achieved.

Comparative Example 3
An aqueous solution of an esterified product was obtained in the same manner as in Example 1 except that phenothiazine (antigelling agent) was not added to the interface meter (A) and the interface meter (B) of the water separator. The above operation was repeated 30 batches, but once a problem occurred due to gelation in the interface meters (A) and (B) in the solvent distillation step. Gels adhered to each interface meter, and the interface and liquid level could not be monitored.

Example 2
6000 parts of diethylenetriamine and 7309 parts of adipic acid were charged into a cylindrical reaction tank equipped with a thermometer, a stirrer, a water separator and a condenser (condenser), and stirred and mixed in a nitrogen atmosphere. The water separator was charged with 2 parts of methoquinone as a gel inhibitor in the cock part. The reaction tank has an outer diameter of 30 cm (heated by an oil bath), a height of 50 cm, an internal volume of 0.03 m ³ , and a structure that allows a connecting tube having an inner diameter of about 2 cm to be connected to a position 10 cm from the center of the reaction tank. is there. A commercially available glass funnel (cooling cylinder length 40 cm, manufactured by Shibata Scientific Instruments Co., Ltd.) was used as the capacitor. A commercially available water determination container (capacity 25 ml, with a cock, manufactured by Shibata Kagaku Kikai Kogyo Co., Ltd.) was used for the produced water separator and the connecting tube. This water separator also has the function of a level gauge because the amount of generated water can be read from a marked line engraved on the side surface of the glass when the cock is closed. The amount of reaction product water is monitored by reading the marked line indicated by the liquid level. When the maximum value of the marked line is reached, the bottom cock is twisted to discharge the reaction product water out of the system, Can be read. The reaction mixture was heated to 150 ° C. and reacted for 20 hours while removing the reaction product water accompanying the condensation polymerization to obtain 11332 parts of the condensation polymer (product water was 1977 parts). Next, 17 parts of hydroquinone methyl ether and 701 parts of methacrylic acid were charged, and an amidation reaction was performed at a reaction temperature of 150 ° C. As a result of carrying out the amidation reaction for 10 hours, 160 parts of the reaction product water was separated by a product water separator to obtain 11890 parts of an amidated product (M2) which is a polyamide polyamine. During the reaction, methacrylic acid contained in the produced water did not gel, and the cock was twisted at any time to discharge water out of the system, and the amount of produced water could be monitored.

Comparative Example 4
An amidated product was obtained in the same manner as in Example 2 except that methoquinone (anti-gelling agent) was not added to the water separator having the function of a liquid level gauge. When the maximum value of the water separator marked line was reached, the cock was twisted to discharge the reaction product water out of the system, but gel was formed in the cock part, so the product water could not be discharged out of the system. From that point on, the amount of reaction product water could not be monitored.

It is the conceptual diagram which showed one form of the water separator in this invention. It is the schematic which showed one form of the apparatus structure used for the manufacturing method of the dehydration reaction product of this invention.

Explanation of symbols

101 Reaction tank 102, 150 Jacket 103 Raw material storage tank for alcohol 105 Raw material storage tank for (meth) acrylic acid 107 Catalyst storage tank 109 Polymerization inhibitor storage tank 111 Neutralizing agent storage tank 113, 115, 117, 119, 121 , 130, 137, 139, 141, 145, 149, 153, 157, 161 Piping 116, 160, 167, 169, 179 Pump 123 Connecting pipe 125, 128 Condenser 126 Spray nozzle 127 Water separator 129 Supply pipe (piping)
131 Baffle 133 Room inside water separator (A)
134 Inside the water separator (B)
135 Generated Water Treatment Tank 136 Interface Meter (A)
138 Interface meter (B)
140 Control valve 142 Circulation pump 143 Dehydrated solvent storage tank 144 Flow meter 147 Antigel storage tank 151 Circulation path 155 Vacuum pump 159 Water soluble antigel storage tank 162 Hole formed in the supply pipe 129

Claims (3)

A method for producing a dehydration reaction product comprising a dehydration reaction step of esterifying and / or amidating an alcohol and / or amine and (meth) acrylic acid in the presence of a dehydrating solvent,
The dehydration reaction step is performed using a reaction vessel and a water separator as essential,
The water separator is provided with a supply pipe connected to the reaction tank, and has a gas phase portion and a liquid phase portion therein, and the lower diameter is smaller than the upper diameter, and the lower diameter is It is constant and controlled so that the interface between the dehydrated solvent and the generated water is kept at the bottom,
The water separator is further detection device of the interface between the product water and dehydrated solvent, and state, and are not provided with a detection device the gas-liquid interface between the gas phase and liquid phase,
An anti-gelling agent is allowed to act on the inside of the detection device for the interface between the dehydrated solvent and generated water and the detection device for the gas-liquid interface between the gas phase part and the liquid phase part. A method for producing a dehydration reaction product. The alcohol has the following general formula (1);
R ¹ O (R ² O) nH (1)
(In the formula, R ¹ represents a hydrocarbon group having 1 to 30 carbon atoms. R ² O is the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms. N represents R ² O. 2. The method for producing a dehydration reaction product according to claim 1, wherein the average added mole number of the oxyalkylene group is 0 to 300. The method for producing a dehydration reaction product according to claim 1 or 2, wherein the dehydration reaction product is used as a raw material for producing a polymer for a cement additive.

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