JP2002166159A - Method of manufacturing dehydration reaction product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method which manufactures dehydration reaction products, applied to the manufacturing of a polymer for cement additives, by a dehydration reaction process in which the use of a vertical multitubular heat exchanger is indispensable, and can sufficiently suppress the occurrence of troubles in a manufacturing process and deterioration in performance and quality of various chemical products by sufficiently suppressing the formation of gel matter in the vertical multitubular heat exchanger. SOLUTION: This manufacturing method of dehydration reaction products comprises a dehydration reaction process in which the use of the vertical multitublar heat exchanger for performing heat exchange between distillate from a reaction liquid and fluid outside a tube is indispensable to manufacture the dehydration reaction products, applied to the manufacturing of the polymer for cement additives, from the reaction liquid. The vertical multitubular heat exchanger has a structure indispensably comprising a body having the inlet and outlet of the liquid outside a tube, covers attached on both upper and lower ends of the body, tube plates installed in the vicinities of both upper and lower ends inside the body, and a plurality of heat-transfer pipes connected between the tube plates. No residence part of the distillate exists substantially in each connecting part between the tube plate and the heat-transfer pipe.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a dehydration reaction product used for producing a polymer for a cement additive, and a method for producing a cement additive obtained thereby.

[0002]

2. Description of the Related Art A method for producing a dehydration reaction product comprising a dehydration reaction step is a method for producing various esters and amides produced from a reaction solution containing a polymerizable compound by esterification or amidation accompanied by a dehydration reaction. Has been applied to Such esters and amides are useful as raw materials for producing various polymers, for example, as (meth) acrylate monomers or (meth) acrylamide monomers.
Such polymers include, for example, cement additives (cement dispersants), pigment dispersants such as calcium carbonate, carbon black, inks, scale inhibitors, dispersants for gypsum / water slurries, and coal / water slurries (CWM). For use in chemical products such as dispersants and thickeners.

In the dehydration reaction step, since esterification, amidation, and the like are reactions that reach chemical equilibrium, the by-product water must be removed from the reaction system, that is, if the generated water accumulates in the reaction system. In addition, the reaction for producing an esterified compound or an amidated compound does not proceed. Therefore, the generated water is removed by distilling (azeotropically) the generated water with a dehydrated solvent. For example, a method of separating and removing generated water from a distillate, performing a reaction by refluxing a dehydrated solvent to a reaction system, and removing and removing a dehydrated solvent from a reaction tank containing an esterified compound or an amidated compound after the reaction is completed. Has been taken.

Japanese Patent Application Laid-Open No. 9-328346 discloses a reactor in which a thermometer, a stirrer, and a water separator are provided in a reactor (separable flask) in Comparative Examples 1 and 2 so that reaction product water can be separated. Methacrylic acid and methoxypolyethylene glycol (average number of moles of oxyethylene groups added: 10 mol) as raw materials, sulfuric acid (Comparative Example 1) or p-toluenesulfonic acid (Comparative Example 2) as an acid catalyst, phenothiazine as a polymerization inhibitor, Cyclohexane as a dehydrating solvent is charged and heated with stirring, and a cyclohexane-water azeotrope is distilled off under normal pressure, and cyclohexane is refluxed while removing water produced by a water separator to carry out an esterification reaction. After completion, a method is disclosed in which the used cyclohexane is distilled off to synthesize a desired esterified product.

In such a production method, a vertical multitubular heat exchanger is used when distilling and condensing an azeotrope (distillate) of the solvent and the produced water or distilling off the solvent. become. In such a vertical multi-tube heat exchanger, as shown in FIG. 5, a distillate is used as a pipe fluid, and the pipe fluid is connected to a plurality of heat transfer pipes connected to an upper tube sheet and a lower tube sheet. The liquid is introduced into the pipe, and then heat-exchanges the fluid in the pipe and the extra-fluid fluid as a cooling liquid. It will be supplied to the separator.

However, the production method using such a vertical multitubular heat exchanger has a problem that a gel-like substance is formed during the production of a dehydration reaction product. Part of such a gel-like substance will accumulate as impurities in the reaction tank.For example, if the impurities adhere to an inner wall of a device such as a vertical multi-tubular heat exchanger or a pipe connected to the reaction tank, a vertical The flow of fluid in the multi-tubular heat exchangers and pipes is deteriorated and blocked, and the heat transfer efficiency of the vertical multi-tubular heat exchangers is reduced and long-term operation is not possible. There is a risk of causing defects, and if mixed into the product,
When used as a raw material for the production of various polymers, they are mixed into chemical products produced from the polymers and cause deterioration in performance and quality. For example, the cement dispersant, while improving the fluidity of the cement composition, has the effect of improving the strength and durability of the cured product, but when the performance and quality are reduced due to contamination by impurities, There is a possibility that the strength, durability, etc. of the cured product such as civil engineering and building structures may be reduced, causing problems such as reduced safety and increased repair costs.

[0007] Japanese Patent Application Laid-Open No. 2000-159881 discloses that an anti-gelling agent is made to act, and Japanese Patent Application No. 11-112535 discloses that a connecting pipe between a reaction tank and a condenser is a double pipe. There is disclosed a method of heating (keeping warm) by performing such operations. However, the structure of the vertical multitubular heat exchanger is designed to sufficiently suppress the occurrence of defects in the manufacturing process due to the formation of gel-like materials and the deterioration of the performance and quality of various chemical products. There was room for research to devise more.

[0008]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above situation, and has been devised to produce a polymer for a cement additive by a dehydration reaction step in which a vertical multitubular heat exchanger is essentially used. A method for producing a dehydration reaction product to be applied, wherein the formation of a gel-like substance in a vertical shell-and-tube heat exchanger is sufficiently suppressed, thereby causing a problem in a production process. It is another object of the present invention to provide a method for producing a dehydration reaction product that can sufficiently suppress deterioration in performance and quality of various chemical products.

[0009]

SUMMARY OF THE INVENTION The present invention relates to a method for producing a dehydration reaction product applied to the production of a polymer for cement additives from a reaction solution, wherein a distillate from the reaction solution and an extrafluid fluid are mixed. A method for producing a dehydration reaction product comprising a dehydration reaction step using a vertical multitubular heat exchanger for heat exchange as an essential component, wherein the vertical multitubular heat exchanger includes an extra-fluid inlet and A body having an extra-tube fluid outlet, lids provided at upper and lower ends of the body, tube plates provided near upper and lower ends inside the body, and a number of heat transfer tubes connected between the tube sheets This is a method for producing a dehydration reaction product, which has a structure that essentially requires the above, and substantially does not have a stagnation portion of the distillate at a connection portion between the tube sheet and the heat transfer tube.

The present invention also relates to a method for producing a dehydration reaction product applied to the production of a polymer for cement additives from a reaction solution, in which a distillate from the reaction solution is subjected to heat exchange with an extrafluid fluid. A method for producing a dehydration reaction product comprising a dehydration reaction step using a type multitubular heat exchanger as essential, wherein the vertical multitubular heat exchanger has an extravascular fluid inlet and an extravascular fluid outlet. It is essential to have a fuselage, a lid provided at upper and lower ends of the fuselage, a tube plate provided near upper and lower ends inside the fuselage, and a number of heat transfer tubes connected between the tube plates. A method for producing a dehydration reaction product wherein the projecting portion of the heat transfer tube is substantially absent on a surface of the tube sheet provided at least near the upper end of the tube sheet where the distillate comes into contact. is there.

The present inventors have conducted intensive studies to efficiently produce a high-quality dehydration reaction product applied to the production of a polymer for a cement additive. As a result, the polymerization inhibitor is usually contained in the reaction solution. Although the formation of a gel-like substance is suppressed due to the presence of, a liquid pool in which the polymerization inhibitor does not act in the vertical multitubular heat exchanger used in the dehydration reaction step, that is, a distillate that distills out of the reaction solution First, paying attention to the formation of a gel-like substance when a liquid pool is formed, it is found that a vertical multi-tube heat exchanger should be devised so that such a liquid pool is sufficiently suppressed. Was. Specifically, (1) a specific portion in the vertical multi-tubular heat exchanger is set so that a stagnation portion of distillate does not substantially exist; (2) a vertical multi-tubular heat exchanger By setting so that the protrusion of the heat transfer tube does not substantially exist on the surface where the distillate of the tube sheet provided at least near the upper end of the tube sheet provided in the vessel is present,
The inventors of the present invention have conceived that it is possible to solve the above problem by suppressing the occurrence of a liquid pool, and have arrived at the present invention. In addition, since the product obtained by the method for producing a dehydration reaction product using such a vertical multitubular heat exchanger is of high quality, this product is used as a cement additive polymer or the like. It has also been found that it can be suitably used as a raw material for production.

Further, in the conventional vertical multi-tube heat exchanger as shown in FIG. 5, (1) a pipe fluid which is a distillate from a reaction solution and an extra-tube fluid which is a cooling liquid are always present. Vibration occurs due to inflow and outflow, and heat transfer tubes receive these vibrations due to vibrations from pumps and compressors and direct pulsating flow from rotating machinery. (2) To improve the heat transfer efficiency, to prevent leakage due to loosening of the connecting portion between the tube plates and (2) to make the connecting portion between each tube sheet and the heat transfer tube strong and to easily attach a large number of heat transfer tubes. It is effective to increase the contact surface with the cooling liquid to reduce the diameter of the heat transfer tubes.However, the pipes with which distillate comes into contact are There will be protrusions of the heat transfer tubes on the plate surface. In the case of producing a dehydration reaction product applied to the production of a polymer from a reaction solution, in the vertical multitubular heat exchanger used in the dehydration reaction step, a stagnation portion of distillate is substantially formed on the tube sheet surface. It has also been found that the above (1) to (3) can be satisfied even if they are set so that they do not exist. Hereinafter, the present invention will be described in detail.

In the method for producing a dehydration reaction product of the present invention, when producing a dehydration reaction product applied to the production of a polymer for a cement additive from a reaction solution, a distillate from the reaction solution and an extra-tube The method includes a dehydration reaction step that essentially uses a vertical multitubular heat exchanger for exchanging heat with a fluid. In a typical embodiment of such a method for producing a dehydration reaction product, a dehydration reaction step of subjecting a reaction solution containing a polymerizable compound to a dehydration reaction is followed by a neutralization step, a solvent distillation step, and the like described below. Comprising. In addition, the vertical multitubular heat exchanger requires a reaction tank, a vertical multitubular heat exchanger, and a connecting pipe connecting the reaction tank and the vertical multitubular heat exchanger in the dehydration reaction step. As a dehydration reaction device. Using such a dehydration reaction apparatus, a condensed and liquefied operation is performed using a vertical multitubular heat exchanger while performing a dehydration reaction in a reaction tank.

In the dehydration reaction step, devices other than a reaction tank, a vertical multitubular heat exchanger, and a connecting pipe connecting them may or may not be used. Since the reaction proceeds when the reaction product water generated by the reaction is removed from the reaction tank, it is preferable to connect a water separator to the vertical multitubular heat exchanger. In such a step, (1) the reaction solution was vaporized by mixing a dehydrating solvent with the reaction liquid as necessary and azeotroping the water with the dehydrating solvent in order to easily remove the reaction water generated in the reaction tank. (2) the distillate passes through a connecting pipe connecting the reaction vessel and the vertical multi-tubular heat exchanger, enters the vertical multi-tubular heat exchanger, and (3) condensed and liquefied distillate in a multi-tubular heat exchanger, (3) dehydrated solvent and water in a water separator connected to a vertical multi-tubular heat exchanger And (4) an operation of refluxing the separated dehydrated solvent into the reaction tank. FIG. 1 is a conceptual diagram illustrating the configuration of the apparatus when such an operation is performed.

In FIG. 1, together with the reactor and the condenser,
One form of a dehydration reaction device that is also provided with a water separator is shown. In this embodiment, a reaction tank, a condenser, a water separator, a strainer, and a pump are provided, and a pipe connecting them is provided. Also,
The connecting pipe connecting the reaction tank and the condenser is shaped so that the distillate exiting the reaction tank rises, goes to the condenser, and then descends into the condenser. In this case, the distillate vaporized in the reaction tank passes through the connecting pipe and enters the condenser, and the distillate condensed and liquefied in the condenser is separated into dehydrated solvent and water in the water separator. As a result, the generated water is removed from the reaction tank, and the dehydrated solvent is filtered by the strainer and returned to the reaction tank by the pump.

First, a dehydration reaction apparatus used in the dehydration reaction step will be described. The term “reaction tank” is used in the same meaning as a reactor, a reaction vessel, a reaction vessel, 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 tank is not particularly limited. There are polygonal type, cylindrical type, etc., but cylindrical type is preferable in terms of stirring efficiency, handleability, versatility and the like. The presence or absence of the baffle plate does not matter. The heating method of the reaction tank may be heating by bringing a heat medium such as steam into contact with the outer jacket, or may be provided with a heat transfer device such as a coil inside the reaction tank to heat. Is also good. The material inside the reaction tank is not particularly limited, and a material of a common quality can be used.
SUS304, SU from the viewpoint of corrosion resistance
S316, SUS316L, more preferably SUS3
16, SUS316L and the like. Further, the inside of the reaction tank may be subjected to a glass lining process or the like so as to be inert to reaction raw materials and products. Such a reaction tank is usually provided with a stirrer for uniformly and efficiently performing a dehydration reaction. The stirrer is not particularly limited. The stirrer is usually composed of an electric motor, a shaft, and a stirrer, and the shape of the stirring blade is not limited. Stirrers include desk turbines, fan turbines, curved fan turbines, arrow blade turbines, multi-stage fan turbine blades,
Faudler blades, bull margin type, angled blades, propeller type, multistage blades, anchor type, gate type, double ribbon blades, screw blades, max blend blades, etc., among which multistage fan turbine blades, Faudler blades Is preferred in terms of versatility.

The vertical multitubular heat exchanger is used in the same meaning as a condenser, a cooler, a condenser, a cylindrical reflux cooling pipe, etc., and is generated from a reaction tank, a water separator, or the like. This is a device that condenses and liquefies distillate. Condensation and liquefaction are performed by exchanging heat between an in-pipe fluid as a distillate and an out-of-pipe fluid as a cooling liquid. The distillate is
It means all that is distilled out of the reaction tank by the dehydration reaction step and other steps. In other words, it means water containing distilled raw materials such as (meth) acrylic acid and the like, in addition to generated water distilled off from the reaction tank and, if necessary, a dehydrating solvent used for azeotropic distillation with the generated water. Examples of the form include gaseous and liquid forms.

The material of the vertical multi-tube heat exchanger is as follows.
SU such as SUS304, SUS316, SUS316L
Known materials such as S and carbon steel (CS) can be used. In order to further reduce the formation of a gel-like material, it is possible to use a mirror-finished or glass-lined inner surface. However, from the viewpoint of processing and maintenance costs, SUS30
4, SUS316, SUS316L, preferably SU
It is preferable to use SUS capacitors such as S316 and SUS316L.

[0019] As the heat transfer area of the vertical multitubular heat exchanger, varies by the volume of the reaction vessel, for example, the reaction vessel 30 m ^3, it is preferable to 50 to 500 m ^2. More preferably, it is 100 to 200 m ² . Examples of the coolant used in such a vertical multi-tube heat exchanger include water and oil.

[0020] 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 .

Next, FIG. 5 is a conceptual diagram illustrating a conventional vertical multitubular heat exchanger using FIGS. 2 to 4 which are conceptual diagrams illustrating a vertical multitubular heat exchanger according to the present invention. It will be described in detail in comparison with. FIGS. 2 and 3 are enlarged conceptual views showing the entire cross section of the vertical multi-tube heat exchanger and the cross section of the connecting portion between the tube sheet and the heat transfer tube according to the present invention. It is the conceptual diagram which showed the cross section of the whole vertical multitubular heat exchanger in this invention, and illustrated the shape of the cover. FIG. 5 is the whole cross section of the conventional vertical multitubular heat exchanger, and FIG. 3 is an enlarged conceptual diagram showing a cross section of a connecting portion between a tube sheet and a heat transfer tube.

2, 3 and 5, the entire cross section of the vertical multitubular heat exchanger is shown on the left, and the cross section of the connecting portion between the tube sheet and the heat transfer tube is shown on the right. I have. Further, the heat transfer tubes are attached to the tube sheet by providing several grooves in the tube sheet and expanding the tube. It should be noted that only one of the plurality of heat transfer tubes is shown, the rest is not shown in the drawing, and other portions such as baffles are also omitted.

The vertical multi-tube heat exchanger has a body having an extra-fluid inlet and an extra-fluid outlet, lids provided at the upper and lower ends of the body, and near the upper and lower ends inside the body. And a plurality of heat transfer tubes connected between the tube sheets. In the above body, the extra-tube fluid inlet is an inlet for introducing the cooling liquid into the vertical multi-tubular heat exchanger, and the extra-fluid outlet is the cooling fluid discharged to the outside of the vertical multi-tubular heat exchanger. This is the exit. The storage form of the extraluminal fluid is not limited to the one-pass type, but may be a two-pass type, a three-pass type, or the like. However, for example, the longitudinal baffle 2
Any of a pass type, a split type, a double split type, a split flow type and the like may be used. The size of the body may be appropriately set according to the manufacturing scale or the like.

In the above-mentioned cover, the cover provided at the upper end of the body is also referred to as a head cover, and the cover provided at the lower end of the body is also referred to as a rear cover. The head cover has an in-tube fluid inlet, and the rear cover has an in-tube fluid outlet. The pipe fluid inlet is an inlet for introducing distillate generated from the reaction solution into the vertical multi-tube heat exchanger, and the pipe fluid outlet is a liquefied and condensed distillate or partially vaporized. This is an outlet for discharging the distillate as it is to the outside of the vertical multitubular heat exchanger. Examples of such a lid include those of the type illustrated in FIGS. 4A to 4E, and examples of the type of the head lid include, for example,
It may be any of a separated lid plate type, an integrated lid plate type, an integrated tube plate type, and the like, and may have a bellows-like distillate flow path in the upper part as shown in FIG. In addition, as a type of the rear lid, for example, a fixed tube plate type, a floating head ground type,
Any of a floating head split flange type, a floating head pull-out type and the like may be used.

In the above tube sheet, the installation position inside the body is not particularly limited as long as it is near the upper and lower ends inside the body. A tube sheet provided near the upper end inside the body is also referred to as an upper tube sheet, and a tube sheet provided near the lower end inside the body is also referred to as a lower tube sheet. With such a tube sheet, the extra-tube fluid and the intra-tube fluid are separated in the vertical multi-tube heat exchanger, and the heat transfer tubes are fixed in the vertical multi-tube heat exchanger.

In the above heat transfer tubes, the outer diameter, length, number of installations, etc. may be appropriately set according to the size, shape, etc. of the vertical multi-tube heat exchanger. Usually, a steel pipe is used as the heat transfer pipe, and the material is preferably, for example, an austenitic steel pipe, an austenitic / ferritic steel pipe, or a ferritic steel pipe because a welded steel pipe is easily produced. With such a material, it is possible to suppress the occurrence of corrosion of the heat transfer tube without reacting with the compound in the distillate, without modifying the product, and the like.

The heat transfer tube is connected between the tube plates. To simplify the connection of the heat transfer tube to the tube plate, a hole is provided in the tube plate, and the heat transfer tube is fitted into the hole. It is preferable that the outer periphery of the end of the heat transfer tube is connected to a hole provided in the tube sheet by attaching and fixing the tube. In such holes,
A sealing material can be used to prevent liquid leakage between the outer periphery of the heat transfer tube end and the hole. As the sealing material, a tape-shaped material may be wound around the heat transfer tube, or a packing may be attached to the hole. The material of such a packing is not particularly limited as long as it is excellent in heat resistance and pressure resistance and does not react with the distillate. For example, a fluorine-based elastomer or silicon can be used. In order to attach the heat transfer tube to the tube sheet without using a sealing material, the tube plate may be expanded by providing several grooves in the tube sheet, or may be welded or the like. In this case, welding is preferable because a large number of heat transfer tubes can be easily attached and liquid leakage is sufficiently prevented.

According to the present invention, there is provided a form in which the stagnation portion of the distillate does not substantially exist in the connection portion between the tube sheet and the heat transfer tube. When the stagnation portion of the distillate is substantially present, the formation of a gel-like substance is usually suppressed because the polymerization inhibitor is present in the reaction solution, but the polymerization inhibitor is hardly contained in the stagnation portion of the distillate. The polymerizable compound contained in the distillate is polymerized due to the absence thereof, and a gel is formed. In the vertical multi-tube heat exchanger, the connection portion between the tube sheet and the heat transfer tube means a portion where the tube sheet and the heat transfer tube are connected and a portion around the connection portion, and is subjected to welding or the like. In this case, it means a part including a welding part. The distillate accumulating portion means a portion where a liquid pool of distillate condensed and liquefied occurs. The substantial absence of the distillate retention part means that the distillate retention part, in which the polymerizable compound contained in the distillate is polymerized to form a gel-like substance, is transmitted to the tube sheet. The purpose is to prevent intentional generation at the connection with the heat pipe. That is, it does not only mean that there is no stagnation portion of distillate at the connection between the tube sheet and the heat transfer tube, but that the stagnation portion of distillate does not intentionally occur at the connection portion. By setting to, the formation of a gel-like material in the connecting portion is suppressed so that no gel-like material is generated, or a decrease in performance or quality of a polymer obtained from a dehydration reaction product is suppressed. Means that no gel is formed. In the present invention, with respect to a plurality of heat transfer tubes, it is preferable that all the heat transfer tubes have the above-described form. However, as long as the effects of the present invention are achieved, some of the heat transfer tubes have the above-described form. It does not have to be.

In the present invention, the tube sheet provided at least in the vicinity of the upper end portion of the tube sheet may have substantially no projecting portion of the heat transfer tube on the surface where the distillate contacts. This makes it possible to effectively perform the dehydration reaction step so that there is substantially no stagnation portion of distillate at the connection between the tube sheet and the heat transfer tube.

In the above embodiment, the tube sheet provided at least near the upper end portion of the tube sheet means that the upper tube sheet is essential. The upper tube sheet is required because distillate tends to remain as a liquid pool at the connection between the tube plate and the heat transfer tube in the upper tube sheet, but the upper tube sheet and the lower tube sheet are required. By doing so, it is preferable to more reliably eliminate the liquid pool of distillate. The surface with which the distillate comes into contact is a surface on the lid side with which the distillate comes into contact, of the two surfaces of each tube sheet, and is also called a tube sheet surface. The fact that the projecting portion of the heat transfer tube does not substantially exist on the surface with which the distillate comes into contact means that the distillate does not substantially exist at the connection between the tube sheet and the heat transfer tube. Means that the projecting portion of the heat transfer tube does not exist on the surface in contact with, for example, the case where the surface in contact with the distillate and the tip of the heat transfer tube are present on the same surface, There is a case where the tip of the heat transfer tube exists between the surface contacting with the distillate and the surface not contacting with the distillate, that is, between the two surfaces of each tube sheet. In the latter case, the tip of the heat transfer tube is embedded in the tube sheet.

In the above embodiment, the method for producing a tube sheet surface having substantially no protrusion of the heat transfer tube includes the following.
For example, as shown in FIG. 2, a method in which the tip of the heat transfer tube and the tube plate surface are installed and fixed by welding, and the heat transfer tube is fixed as shown in FIG. 3. The tip is installed so as to be embedded in the tube sheet and fixed by welding the tip of the heat transfer tube and the hole of the tube sheet so that the tip of the welded portion and the tube sheet surface are flush with each other. A method of supplementing the welding material and polishing if necessary; fixing the heat transfer tube in advance by installing and welding so that the tip of the heat transfer tube projects from the tube plate surface, and cutting the protrusion And polishing methods.

In the above embodiment, it is preferable that the tube sheet surface has substantially no irregularities. If there is an uneven portion on the surface of the tube sheet, the concave portion may become a staying portion for distillate. When there is substantially no uneven portion on the tube sheet surface, for example, when a gap is generated between the tube sheet and the heat transfer tube, or by embedding the tip of the heat transfer tube in the tube sheet, In the case where a step is formed between the surface of the heat transfer tube and the front end portion, the formation of a welded portion prevents the presence of an uneven portion where a stagnation portion of distillate substantially exists. Also, if the tube sheet surface is JIS
Rma, which is a standard of surface roughness specified in B0601
It is preferable that x is set to 12.5S or less. More preferably, it is 3.2S or less. Thereby, the stagnation portion of the distillate can be more reliably eliminated.
In order to adjust the surface roughness of the tube sheet surface in this way, it can be performed by welding and connecting the heat transfer tube to the tube sheet, but it may be further performed by surface treatment.

Examples of the surface treatment include mechanical polishing such as buffing and electrolytic polishing. The buff polishing is a polishing method mainly used when the surface is smooth or glossy, and can be performed by rough polishing with a fixed abrasive, medium polishing with a semi-solid or free abrasive, or finish polishing. In this case, in addition to polishing using a flexible material such as leather or cloth, tripolysilica, chromium oxide,
Polishing can be carried out using an oily or non-oily or spray agent containing silicon carbide, fused alumina, calcined alumina, or chromium oxide as an abrasive.

In the above surface treatment method, electropolishing is a polishing method used for smoothing a metal surface while dissolving the metal surface. When the material of the heat transfer tube is steel, an electrolytic polishing solution such as , Perchloric acid, sulfuric acid, phosphoric acid, sulfuric acid-phosphoric acid, and the like. At this time, since the structure of the steel greatly differs depending on the composition and the degree of heat treatment and processing, the steel is appropriately selected in consideration of these. The amount of acetic anhydride generally added to the perchloric acid-based electrolyte, the electrolysis temperature, the current density, the voltage, the electrolysis time and the like may be appropriately selected depending on the material of the heat transfer tube. The seamless steel pipe, the cold-finished automatic arc welded steel pipe, and the welded processed finish automatic arc welded steel pipe may be mechanically polished and further subjected to electrolytic polishing.

In the present invention, since the stagnation portion of the distillate may also exist on the tube sheet surface other than the connection portion between the tube sheet and the heat transfer tube, the liquefied and condensed distillate can be quickly collected in the vertical type. It is preferable to discharge to outside the tubular heat exchanger. As a method for doing so, for example, it is preferable to adjust the surface roughness of the tube sheet surface as described above.

The vertical multi-tube heat exchanger according to the present invention is not particularly limited with respect to other parts as long as it has the above-mentioned structure. , Partition chamber body flange, body lid side flange,
It may have a body side nozzle, floating head lid, fixed rod and spacer, gas vent seat, drain vent seat, instrument seat, support leg, hanging bracket, liquid level gauge seat, etc. It may be applied.

In the method for producing a dehydration reaction product of the present invention,
The reaction solution contains (meth) acrylic acid and / or its dehydration reaction product (ester or amide). As described above, when (meth) acrylic acid and / or its dehydration reaction product (ester or amide) is contained, a gel-like substance is easily formed in the vertical multitubular heat exchanger. Can be fully exhibited.

In the method for producing a dehydration reaction product of the present invention, in order to more effectively prevent polymerization of distillate inside the dehydration reactor, the molecular oxygen-containing gas and / or An anti-gelling agent may be acted on,
For example, when the distillate and the extrafluid fluid are heat-exchanged with each other by the vertical multitubular heat exchanger to perform the dehydration reaction step, it is preferable to cause the distillate to act on the gelling inhibitor. Examples of such a gelling inhibitor include a polymerization inhibitor and the like. Specifically, 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, cuperon, copper (II) chloride and the like. These may be used alone,
Two or more kinds may be used in combination. Among these, it is preferable to use phenothiazine, hydroquinone, and methoquinone.

As the amount of the above gelling inhibitor, for example,
Dehydration reaction conditions, among them, depending on the amount of heat applied to the reaction system and the amount of dehydration solvent charged into the reaction system, etc., are preferably set appropriately to an amount corresponding to the amount of distillate, for example, alcohol or amine as a reaction raw material It is preferably 0.1 to 5000 ppm by weight based on the total weight of the charged amounts of (meth) acrylic acid and (meth) acrylic acid. If it is less than 0.1 ppm by weight,
There is a possibility that the function and effect of the gelling inhibitor may not be sufficiently exerted, and if it exceeds 5,000 ppm by weight, it may be uneconomical to exhibit the effect corresponding to the amount to be acted on. More preferably, 5 to 500 weight pp
m.

The method for causing the above-mentioned gelling inhibitor to act is not particularly limited as long as the action and effect of the gelling inhibitor can be exerted effectively. It may be a part that acts on gaseous distillate before being condensed and liquefied by the multitubular heat exchanger, and it can be used for liquid distillate condensed and liquefied by the vertical multitubular heat exchanger. It may be a part that acts
Both of the above parts may be used. For the polymerizable compound in the gaseous distillate, since the temperature is high and the anti-gelling agent does not act, the anti-gelling agent acts particularly on the gaseous distillate. It is effective. In addition, as the timing of the action, the total amount of the anti-gelling agent is finally within the above range by applying a fixed amount sequentially from the start of distillation to the end of the reaction corresponding to the amount of distillate distilled out. It is preferable to set so that Furthermore, the form of the gelling inhibitor to be acted on is as follows:
Form, solidified form such as powder, and vaporized form including sublimated state, among them, among these, the form liquefied by a solvent or the like, particularly the form liquefied by the same type of solvent as the dehydration solvent preferable.

As a specific method of causing the above-mentioned gelling inhibitor to act, for example, spraying is carried out from the upper part of the vertical multi-tube heat exchanger, particularly from the vicinity of the tower top, to the connecting pipe so as to come into countercurrent contact with the distillate. A method for preparing a gelling inhibitor in a vertical multi-tubular heat exchanger, and blowing gaseous distillate into the heat exchanger, or pouring liquefied distillate into the heat exchanger, thereby contacting, dissolving or contacting. Dispersion methods and the like can be mentioned. In these cases, in addition to the above-mentioned action site, a joint (flange) between the reaction tank and the connecting pipe and a flange between the connecting pipe and the top of the vertical multi-tube heat exchanger are also provided. An anti-gelling agent may be applied to a site where a gel-like substance is likely to be formed, such as a flange portion of, for example, a thermometer installed in a reaction tank or a projection provided in a viewing window, and a vertical multi-tube type. It is preferable that the vicinity of the top of the heat exchanger and the flange be the working site. In the flange portion, a gelling preventing effect can be obtained by supplying a dehydrating solvent or the like. Further, as a specific method of causing the molecular oxygen-containing gas to act, for example, there is a method of directly mixing gaseous distillate by spraying or the like.

In the method for producing a dehydration reaction product of the present invention, it is preferable that the dehydration reaction product is used as a raw material for producing a cement additive. That is, it is preferable to use a dehydration reaction product produced by the production method of the present invention as a raw material for producing a cement additive. This allows
In the production of the cement additive, it is possible to suppress the deterioration of the properties and quality and to produce the cement additive stably.

As described above, the vertical multitubular heat exchanger used in the method for producing a dehydration reaction product according to the present invention comprises a reaction solution for dehydration reaction applied to the production of a polymer for cement additives. When manufacturing from the point, the occurrence of liquid pools such as the formation of gel-like material in the vertical multi-tube heat exchanger was suppressed, which caused defects in the manufacturing process and various chemical products. It exerts the effect of being able to sufficiently suppress deterioration in performance and quality. Such a vertical multi-tube heat exchanger is one of preferred embodiments of the present invention.

Next, as a method for producing a dehydration reaction product applied to the production of a polymer for a cement additive from a reaction solution, a dehydration reaction step is carried out, followed by a neutralization step and a solvent distillation step as required. A method including the above will be described. The dehydration reaction step is preferably a step in which a reaction liquid containing an alcohol and (meth) acrylic acid is subjected to an esterification reaction or an amidation reaction to generate a dehydration reaction product. Since such a process easily forms a gel-like material, the function and effect of the present invention can be sufficiently exhibited. In the method for producing a dehydration reaction product, the compounds used as reaction raw materials may be used alone or in combination of two or more. The dehydration reaction product is also called an ester, an ester, an amide or an amid.

The alcohol used in the esterification reaction is not particularly limited as long as it is a compound having a hydroxyl group. Examples thereof include alcohols, phenols, diols, trivalent or higher alcohols, and polyols. Can be For example, as alcohols, methanol, ethanol, n-propanol, n-butanol, 2-ethylbutanol, n-octanol, 1-dodecanol, 1-octadecanol, 2-ethylhexanol,
Cyclohexanol, allyl alcohol, 3-methyl-
Primary alcohols such as 3-buten-1-ol;
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 "Sophtanol (trade name)" manufactured by Nippon Shokubai; tertiary alcohols such as tert-butanol and tert-pentanol; and phenols Phenol, cresol, o-cresol, m
-Cresol, p-cresol, and the like. Examples of diols include monoethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, monopropylene glycol, dipropylene glycol, polyethylene polypropylene glycol, diethanolamine, and N-butyl. Diethanolamine and the like, and trihydric or higher alcohols and polyols include glycerin, trimethylolpropane, 1,3,5-pentanetriol, pentaerythritol, glucose, fructose, sorbitol, gluconic acid, tartaric acid, and polyvinyl alcohol Is mentioned.

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

R ¹ O (R ² O) nH (1) In the 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 an average number of added moles of the oxyalkylene group represented by R ² O, and is a number of 0 to 300, preferably 2 to 300. The average number of moles added means the average value of the number of moles of the repeating unit in 1 mole of the compound.

When the number of carbon atoms of R ¹ exceeds 30 or the number of carbon atoms of R ² O exceeds 18, the water solubility of the polymer obtained by using the esterified product as a raw material decreases, and cement additives, etc. The use performance, that is, the cement dispersing performance and the like may be reduced. The above n
Exceeds 300, the reactivity between the compound represented by the general formula (1) and (meth) acrylic acid may be reduced.

The preferred range of the carbon number of R ¹ or R ² O is determined according to 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 is, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group. , Pentyl, hexyl, octyl, nonyl, 2-ethylhexyl, decyl, dodecyl, undecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl An alkyl group such as a heneicosyl group or a docosyl group; an aryl group such as a phenyl group; a benzyl group;
An alkylphenyl group such as a nonylphenyl group; a cycloalkyl group such as a cyclohexyl group; an alkenyl group; an alkynyl group. Among these, carbon number 1-18
It is preferable to use a linear or branched alkyl group and aryl group. More preferred are a methyl group, an ethyl group, a propyl group, a butyl group and a phenyl group.

The R ² O includes, for example, an oxyethylene group, an oxypropylene group, an oxybutylene group, an oxystyrene group and the like. Of 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. Of these, 2
When there are more than one kind of different repeating units, each repeating unit may be added in a block shape or in a random shape, and is not particularly limited.

The range of the above-mentioned n is also set according to the intended use of the esterified product. preferable. More preferably, it is 5 to 200, still more preferably 8 to 1
50. When used as a thickener or the like, 1
It is preferable to set it to 0 to 250. More preferably, 5
0 to 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, particularly alcohols such as methanol and ethanol have a low boiling point and evaporate together with the produced water and dissolve in the produced water, whereby a part of the alcohol raw material is distilled out of the reaction system,
This is to prevent the yield of the desired esterified product from being reduced.

The amine used in the amidation reaction is not particularly restricted but includes, for example, ammonia; aliphatic primary amines such as methylamine, ethylamine, propylamine, butylamine, dodecylamine and cetylamine;
Dimethylamine, diethylamine, dipropylamine,
Aliphatic secondary amines such as diamylamine; aliphatic tertiary amines such as trimethylamine, triethylamine, tripropylamine and tributylamine; aliphatic unsaturated amines such as allylamine and diallylamine; cyclopropylamine, cyclobutylamine and cyclohexylamine Alicyclic amines such as aniline, monomethylaniline,
Aromatic monoamines such as dimethylaniline and diphenylaniline; aromatic diamines such as o-phenylenediamine and m-phenylenediamine; α-naphthylamine, β
-Aminonaphthalenes such as naphthylamine; polyalkylenepolyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, dipropylenetriamine, tripropylenetetramine and tetrapropylenepentamine; monoethanolamine, diethanolamine, polyethylene glycol Oxyethylene amines such as (mono) amine and polyethylene glycol (di) amine; ureas such as urea and thiourea; polyethylene imine; ethylene oxide adducts to polyethylene imine; propylene oxide adducts to polyethylene imine; Molecules and the like.

In the above esterification reaction and amidation reaction,
Along with (meth) acrylic acid, other unsaturated monomers having a carboxyl group can be used. The unsaturated monomer having a carboxyl group is a monomer having at least a carboxyl group and an unsaturated bond. In particular,
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,
Unsaturated dicarboxylic acids such as citraconic acid, mesaconic acid and itaconic acid; These may be used alone or in combination of two or more.

In the above esterification reaction or amidation reaction, if necessary, a catalyst may be added to the reaction system, and the reaction is preferably performed in the presence of a catalyst. Particularly, in the esterification reaction, an acid catalyst is suitable, and the reaction can be promptly advanced. 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, xylenesulfonic Acid hydrate, naphthalenesulfonic acid, naphthalenesulfonic acid hydrate, trifluoromethanesulfonic acid, “Nafion (trade name, manufactured by DuPont)” resin, “Amberlyst 15 (trade name)” resin, phosphotungstic acid, phosphotungsten Acid hydrate, hydrochloric acid and the like can be mentioned. These may be used alone or in combination of two or more.

Among the above-mentioned acid catalysts, from the viewpoint of the azeotropic temperature and reaction temperature of the dehydrating solvent and water, which will be described later, at normal pressure (1013
Those having a high boiling point at hPa), specifically those having a boiling point at normal pressure of 150 ° C. or higher, 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, 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 the desired catalytic action can be effectively exhibited, and is preferably, for example, 0.4 meq / g or less. When the amount exceeds 0.4 meq / g, the amount of impurities formed in the reaction system during the esterification reaction or the amidation reaction increases, and the cement dispersing ability of the polymer for cement additive synthesized using the same increases. May decrease.
More preferably, it is 0.36-0.01 meq / g, and still more preferably, 0.32-0.05 meq / g.
It is. In addition, the amount of use of the acid catalyst (meq / g)
The number of equivalents of H ⁺ of the acid catalyst used in the reaction (milliequivalents)
It is represented by a value divided by the total charge (g) of the reaction raw materials, and specifically means a value calculated by the following formula.

[0058]

(Equation 1)

The amount of the acid catalyst used also depends on the usefulness of the esterified or amidated compound used as a raw material for producing the polymer applied to various chemical products and the basic performance required for such an application. The ratio of the weight of the acid in the acid catalyst to the total weight of the reaction materials is X
(% By weight) and the ratio of the weight of water present as a hydrate and / or aqueous solution in the acid catalyst is represented by Y (% by weight), the relational expression of 0 <Y <1.81X-1.62 is obtained. Is preferably satisfied.

The above-mentioned relational expression will be described with reference to 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 (weight %), And the ratio of the weight of water present as a monohydrate to the total weight of the reaction raw materials is Y (% by weight). Nevertheless, as an acid component other than the acid catalyst, for example, ( (Meth) acrylic acid, etc. and water, ie, water produced by the dehydration reaction, etc.
It cannot be the X or Y object.

When the amount of the acid catalyst used does not satisfy the above relational expression, for example, when Y is 0, there is no water present as a hydrate and / or aqueous solution in the acid catalyst. The amount of gel formed in the reaction system at the time of the dehydration reaction increases, and there is a possibility that, for example, the cement dispersing ability or the like as a use performance of a polymer for a cement additive or the like synthesized using the same may decrease. Also, Y ≧ 1.81X−
When it is 1.62, the amount of gel formed in the reaction system during the dehydration reaction increases, which is the same as above. As a method for adding the acid catalyst to the reaction system, the acid catalyst may be added all at once, continuously or sequentially. However, from the viewpoint of workability, it is preferable to charge the reaction tank together with the reaction raw materials in the reaction tank.

The above esterification reaction and amidation reaction are preferably performed in the presence of a polymerization inhibitor. Thereby, the 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,
Cuperon, 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. They are,
It is very useful in both the dehydration reaction step and the solvent distilling step, since the polymerization inhibiting ability can be exhibited very effectively.

The amount of the above-mentioned polymerization inhibitor to be used may be 10
If it is 0% by weight, it is preferably 0.001 to 1% by weight. When the amount is less than 0.001% by weight, the polymerization inhibiting ability is not sufficiently exhibited, and it is difficult to effectively prevent the polymerization of the reaction raw materials and products. Increase the amount of polymerization inhibitor
There is a possibility that quality and performance may be reduced, and an effect corresponding to excessive addition may not be obtained, which may be disadvantageous from an economic viewpoint. More preferably 0.001 to
0.1% by weight.

The dehydration reaction in the above esterification or amidation reaction can be performed without a dehydration solvent.
By using a dehydration solvent, for example, it is preferable to perform azeotropic distillation of the generated water and the dehydrated solvent outside the reaction system, to condense and liquefy, and to reflux while separating and removing the generated water. As a result, it is possible to efficiently azeotropically generate water generated in the esterification reaction or the amidation reaction. Such a dehydrating solvent is not particularly limited as long as it is a solvent azeotropic 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 them, those having an azeotropic temperature with water of 150 ° C. or less are preferable,
What is -90 degreeC is more preferable. Specific examples of such a dehydrating solvent include cyclohexane, toluene, dioxane, benzene, isopropyl ether, hexane,
Heptane and the like can be mentioned. When the azeotropic temperature with water exceeds 150 ° C., there is a possibility that the handleability including the temperature control in the reaction system during the reaction and the control of the distillate condensed and liquefied and the like may be deteriorated.

In the dehydration reaction operation using the above dehydration solvent, the amount of the dehydration solvent used is 0 to 100% by weight, assuming that the total charged amount of alcohol, amine and acid, which are the reaction raw materials, is 100% by weight. preferable. If it exceeds 100% by weight, an effect corresponding to excessive addition cannot be obtained, and a large amount of heat is required to maintain a constant reaction temperature, which may be disadvantageous from an economic viewpoint. More preferably, it is 2 to 50% by weight.

In the above-mentioned dehydration reaction step, the esterification reaction and the amidation reaction can be carried out by any of batchwise or continuous reaction operation methods, but are preferably carried out batchwise. The reaction conditions are not particularly limited as long as the reaction proceeds smoothly. For example, the reaction temperature is preferably 30 to 180 ° C. More preferably, it is 60 to 130 ° C., still more preferably,
90-125 [deg.] C, most preferably 100-12.
0 ° C. When the temperature is lower than 30 ° C., the reflux of the dehydrating solvent is delayed, and the dehydration takes a long time. In addition, the reaction may be difficult to proceed. In polymers obtained from amides and amidates, the dispersing performance and thickening properties in various applications such as cement dispersing performance decrease, polymerization of reaction raw materials, increase in the amount of reaction raw materials mixed into distillate, esterification products and The performance and quality of the amidated compound may be deteriorated.

Under the above reaction conditions, it is preferable that the reaction time is set until the reaction rate reaches 70% or more as described later. More preferably, it reaches 80% or more, even more preferably 98% or more. Usually, 1 to 100 hours, preferably 3 to
60 hours. The reaction pressure may be either normal pressure or reduced pressure. However, it is preferable to perform the reaction under normal pressure from the viewpoint of facilities.

It is preferable that the reaction rate of the above esterification reaction or amidation reaction is set to be 70% or more. If it is less than 70%, the yield of the produced ester or amide is insufficient, and there is a possibility that the performance of the polymer such as a polymer for a cement additive obtained using this as a polymerization raw material, that is, the cement dispersing ability or the like may be reduced. is there. More preferably, it is 70 to 99%, and still more preferably 80 to 98%. The above-mentioned reaction rate is a ratio of the amount of alcohol or amine as a reaction raw material at the time of preparation and at the time of completion of the reaction, and is measured as, for example, each peak area by liquid chromatography (LC) under the following measurement conditions. This is a value (%) calculated by the following equation.

[0069]

(Equation 2)

[0070]Reaction rate measurement conditions  Analysis device: Millennium manufactured by Waters
Chromatography Manager (product name) Detector: Waters 410 RI detector (product
Name) Column used: Inertsil ODS manufactured by GL Sciences
-2 (4.6 mm inner diameter, 250 mm length) (product name)
Column temperature: 40 ° C. Eluent: 8946 g of water, 6000 g of acetonitrile and
Mix 54 g of acetic acid and add 30% aqueous sodium hydroxide
Use the solution adjusted to pH 4.0 with. 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 for 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 the amidation reaction is suppressed, and the generation of impurities not involved in the polymerization is suppressed. It is possible to suppress the decrease. When a dehydrating solvent is used, it is preferable to perform a solvent distilling step of distilling off the dehydrating solvent in order to remove the dehydrating solvent.

As a method of the above-mentioned neutralization step, for example, a method in which the esterification reaction or the amidation reaction is completed and then the acid catalyst is neutralized with a neutralizing agent is preferable. The neutralizing agent is not particularly limited as long as it can neutralize the acid catalyst. For example, hydroxides of alkali metals and alkaline earth metals such as sodium hydroxide, potassium hydroxide, calcium hydroxide and lithium hydroxide; carbonates of alkali metals and alkaline earth metals such as sodium carbonate, calcium carbonate and lithium carbonate Salt; amines such as ammonia, monoethanolamine, diethanolamine, and triethanolamine, and the like, and one or more of these can be used. The form of the neutralizing agent is not particularly limited, and for example, is preferably in the form of an aqueous alkaline solution.

In the neutralization step, the acid catalyst and (meth) acrylic acid are neutralized.
It is preferable to set so that a part of (meth) acrylic acid is 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 the amidation reaction is 100% by weight. % By weight. Note that, between the acid catalyst and the (meth) acrylic acid, the acid catalyst has a higher acid strength, and is neutralized by the acid catalyst.

In the neutralization method in the above neutralization step, when performing an esterification reaction or an amidation reaction in a dehydrating solvent, it is preferable to add a large amount of water to the reaction system together with the alkali. In other words, in the absence of a large amount of water, the alkali is hardly soluble in the dehydrating solvent, so that the alkali floats in the system in a concentrated state. It will not disappear and will cause hydrolysis of the esterified or amidated product. In this case, although the amount of water to be added depends on the form of use of the alkali, for example, when an aqueous solution of 40 to 60% by weight is added as a neutralizing agent, separately from the aqueous alkali,
Usually 5 to 1000 parts by weight based on 1 part by weight of the aqueous alkali solution.
It is preferred to be parts by weight. More preferably, 10
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, a neutralization tank is separately required to secure productivity, and the production cost increases. There is a possibility that.

The neutralization temperature in the neutralization step is as follows:
For example, the temperature is preferably 90 ° C. or lower. More preferably, it is 0 to 80 ° C. Even more preferably 25 to 6
5 ° C. If the temperature exceeds 90 ° C., the added neutralizing agent may act as a catalyst for hydrolysis, and may generate a large amount of hydrolysis products. When the temperature is 80 ° C. or less,
Although the generation of hydrolysis products will be more sufficiently suppressed, if the temperature is lower than 0 ° C., it becomes difficult to stir due to the viscous reaction solution, and water is distilled off after the reaction. Therefore, it takes a long time to lower the temperature to a predetermined temperature, and it is necessary to provide a new cooling means (device) to lower the temperature to a temperature lower than room temperature, which may increase the production cost. .

In the solvent removal step, the method for removing the dehydrated solvent is not particularly limited. For example, the solvent may be removed by distilling off only the dehydrated solvent, and other appropriate additives may be added. The solvent may be distilled off, but it is preferable that the solvent is distilled off by azeotropic distillation with a dehydrating solvent using water. In this case, since the neutralization step has been performed, there is substantially no acid catalyst or alkali in the reaction system. Therefore, even if water is added and the temperature is raised, no hydrolysis reaction occurs. By such a method, the dehydrating solvent can be efficiently removed at a lower temperature.

The conditions for the above-mentioned distillation method are not particularly limited as long as they are set so as to suitably distill (evaporate) the dehydrated solvent in the reaction system. (Under normal pressure) when water is used, it is usually 80 to
The temperature is preferably set to 120 ° C. More preferably, 90
１１０110 ° C. When water is not used, it is usually preferable to set the temperature to 80 to 160 ° C. More preferably, it is 90 to 150 ° C. In any of the above cases,
If the temperature is lower than the above temperature, the temperature (heat amount) may not be sufficient to evaporate the dehydrating solvent. If the temperature is higher than the above temperature, polymerization may be caused, and a large amount of heat may cause a large amount of low boiling point. The raw materials may be consumed for evaporation. The pressure in the reaction tank may be either normal pressure or reduced pressure. However, from the viewpoint of equipment, the reaction is preferably performed under normal pressure. As the apparatus used in the solvent distillation step, it is preferable to use the apparatus used in the dehydration reaction step as it is.

The dehydration reaction product obtained by the present invention is
It will be suitably applied as a raw material for producing a polymer for a cement additive, but a polymer produced from such a dehydration reaction product, for example, besides a cement additive, carbonic acid It can also be used for chemical products such as calcium, carbon black, pigment dispersants such as inks, scale inhibitors, gypsum / water slurry dispersants, coal / water slurry (CWM) dispersants, and thickeners.

Hereinafter, a method for producing a polymer for a cement dispersant using the dehydration reaction product obtained according to the present invention as a production raw material, a method for producing a cement additive containing the polymer for a cement dispersant, The method of using the cement additive will be described.

Examples of the polymer for a cement dispersant include a polycarboxylic acid polymer obtained by polymerizing the obtained dehydration reaction product and a monomer containing an unsaturated carboxylic acid monomer as an essential component. No. The method for polymerizing such a polycarboxylic acid polymer is not particularly limited, and for example, a known polymerization method such as solution polymerization or bulk polymerization using a polymerization initiator can be employed.

Examples of the unsaturated carboxylic acid monomer include (meth) acrylic acid, crotonic acid, tiglic acid,
Unsaturated monocarboxylic acids such as 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 and itaconic acid; dicarboxylic acids of these And monoesters of alcohol and the like, and monovalent metal salts, divalent metal salts, ammonium salts and organic amine salts thereof.

A monomer other than the unsaturated carboxylic acid monomer can be copolymerized with the polycarboxylic acid polymer, if necessary. Examples of such a monomer 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 styrenesulfonic acid, and monovalent metal salts, divalent metal salts, almonium salts, and organic amine salts thereof; styrene, α- Aromatic vinyls such as methylstyrene; esters of (meth) acrylic acid with an alcohol having a phenyl group such as an aliphatic alcohol having 1 to 18, preferably 1 to 15 carbon atoms or benzyl alcohol; polyalkylene glycol mono ( (Meth) acrylate; polyalkylene glycol mono (meth) allyl Ether and the like.

The above-mentioned 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. 50
If it is less than 0, the water reducing performance of the cement additive may decrease, and if it exceeds 500,000, the water reducing performance and the slump loss preventing ability of the cement additive may decrease. More preferably, it is in the range of 5,000 to 300,000, and most preferably in the range of 8,000 to 100,000.

The above-mentioned GPC comprises an eluent storage tank, an eluent sending device, an autosampler, a column oven, a column,
It consists of 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 devices.

[0085]Molecular weight measurement conditions  Model: LC module 1plus (product name, WATE
Detector: Differential refractometer (RI) 410 Differential refractometer (product)
Eluent: 0.05M sodium acetate, acetonitrile
/ Ion-exchanged water = 40/60 mixture to pH 6 with acetic acid
Use the adjusted one. Eluent flow rate: 1.0 ml / min Column: TSK-GEL guard column (inner diameter 6 mm, length 40)
mm) + TSK-GEL G-4000SWXL (inner diameter 7.8
mm, length 300 mm) + TSK-GEL G-3000SWXL (inner diameter 7.8)
mm, length 300mm) + TSK-GEL G-2000SWXL (inner diameter 7.8)
mm, length 300 mm) (All trade names, manufactured by Tosoh Corporation) Column oven temperature: 40 ° C

Calibration curve: The calibration curve varies depending on the molecular weight and number of the standard sample, how to draw the baseline, the method of preparing the calibration curve approximation, and the like. For this reason, it is preferable to set the following conditions. 1. Standard Samples Standard samples include commercially available standard polyethylene oxide (PE
O) and standard polyethylene glycol (PEG). It is preferable to use a standard sample having the following molecular weight. 1470, 4250, 7100, 12600, 2400
0, 46000, 85000, 219300, 2725
00 (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 2,000 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 ± 30,000 is included. (5) At least one standard sample having a molecular weight of 270000 ± 30,000 is included.

2. How to draw the baseline Upper limit of molecular weight: The point where the peak rises from the horizontal stable baseline. Lower limit of molecular weight: The point at which detection of the main peak is completed. 3. Approximate Formula of Calibration Curve A calibration curve ("elution time" vs. "log molecular weight") prepared using the above standard sample forms a cubic approximation and is used for calculation.

The above-mentioned cement dispersant containing a polycarboxylic acid polymer can exhibit good cement dispersing performance and slump retention performance. An agent (cement dispersant) may be further added.

The above-mentioned cement dispersants also include an air entrainer, a cement wetting agent, a swelling agent, a waterproofing agent, a retarder, a quick-setting agent, a water-soluble polymer, a thickener, a coagulant, a drying shrinkage reducing agent, and a strength. An enhancer, a curing accelerator, an antifoaming agent and the like can be added. The cement dispersant thus obtained is
As a cement composition containing cement or water, for example, portland cement, belite-rich cement, alumina cement, hydraulic cements such as various mixed cements, and hydraulic materials other than cement such as gypsum will be used .

As to the amount of the cement dispersant added to the hydraulic material, excellent effects can be exhibited even when a small amount is added as compared with the conventional cement dispersant. When used for cement or concrete, if the weight of cement is 100% by weight,
What is necessary is just to add the amount of the ratio which becomes 0.001-5 weight% at the time of kneading. If the amount is less than 0.001% by weight, the function and effect of the cement dispersant may not be sufficiently exhibited. There is a risk. More preferably, it is preferably 0.01 to 1% by weight. As a result, various operational effects such as achievement of a high water reduction rate, improvement of slump loss prevention performance, reduction of unit water amount, increase of strength, and improvement of durability can be achieved.

[0091]

BEST MODE FOR CARRYING OUT THE INVENTION A method for producing an esterified product according to the present invention is shown in FIG.
This will be described with reference to FIG. Note that such an embodiment is a typical example of the present invention, and the embodiment of the present invention is not limited to this. Hereinafter, the vertical multitubular heat exchanger in the present invention will be described as a condenser.

In FIG. 6, first, the temperature is raised to a predetermined temperature to perform a dehydration reaction step, and then the temperature is lowered to a predetermined temperature to perform a neutralization step. An apparatus configuration for performing a cleaning step after the cleaning is shown. In such an apparatus configuration, a distillate containing reaction water generated during the dehydration reaction in the reaction tank 101 is distilled off, and after condensed and liquefied by the condenser 125 while preventing the generation of a gel-like substance, the water is removed. 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 at a predetermined solvent circulation speed by the pump 142 and returned to the reaction tank 101. In such a circulation mechanism, the reaction tank 1
01 is connected to the top of a vertical multitubular cylindrical condenser 125 of countercurrent or cocurrent contact type by a connecting pipe 123, and the lower bottom of the condenser 125 and the upper part of the water separator 127 are connected to a supply pipe. (Piping) 129 connects the reaction tank 101 and the water separator 127 with a supply pipe 129.

The above-mentioned reaction tank 101 is used as a heat exchange means.
An outer jacket 102 that can use hot water, Kasho steam, or the like as a heat medium is provided. A temperature sensor (not shown) for measuring a reaction temperature is provided in the reaction tank 101.
Are attached at appropriate locations. Such a temperature sensor is electrically connected to a control unit main body (not shown) to keep the reaction temperature at a specified temperature. As the above-mentioned device mechanism, for example, a jacket 102 attached to the reaction tank 101 and the like can be mentioned.

The condenser 125 is made of SUS304 and includes a body and a lid. An upper tube sheet 174 and a lower tube sheet 175 are provided near the upper and lower ends of the body, and a plurality of capacitors are provided between the tube sheets. Of heat transfer tubes 173 are connected. The fuselage has an extraluminal fluid inlet and an extraluminal fluid outlet, with arrows indicating that extraluminal fluid enters from the extraluminal fluid inlet and exits from the extraluminal fluid outlet. At the top of the condenser 125, a fluid inlet in the pipe connected to the pipe 123 is provided on the head cover, and at the lower bottom of the condenser 125, a fluid outlet in the pipe connected to the pipe 129 is provided on the rear lid. ing. In the condenser 125, as shown in FIG. 2 or FIG.
The heat transfer tube 173 is connected between the upper tube sheet 174 and the lower tube sheet 175 such that the protrusion of the heat transfer tube 173 does not substantially exist.

The water separator 127 is made of SUS304, and has a partition plate 131 provided therein, and two chambers 133 and 134 separated by the partition plate 131 are formed. Among these, the lower part of the chamber 133 on the side where the distillate condensed and liquefied by the condenser 125 is stored and the treatment tank 135 for the reaction generated water are connected by a pipe 137. A wastewater pipe 139 is connected to the treatment tank 135, and the lower part of the other chamber 134 of the water separator 127 and the reaction tank 101 are connected to each other by a pipe 141.
A pipe 145 connected to a dehydration solvent storage tank 143 that stores a dehydration solvent azeotropic with the reaction product water in the reaction tank 101 is connected to 1. In addition, a circulation pump 142 is installed on the path of the pipe 141 just before the junction (on the water separator 127 side), and behind the junction (the reaction tank 101).
A flow meter 144 is provided on the path of the pipe 141 on the side). Further, the flow meter 144 is electrically connected to a flow measurement system main body (not shown) for integrating a measured flow rate and calculating a solvent circulation speed.

In the above water separator, a condenser 128 is mounted in the gas phase. The dehydrating solvent and volatile (meth) acrylic acid in the gas phase of the water separator
Since it is cooled sufficiently at 28, it is not released out of the system. Further, the condenser 128 is provided with an opening (a so-called vent), so that the pressure in the reaction system does not excessively increase even when the reaction tank is heated, and damage to the instrument is prevented. When such a capacitor 128 has a structure similar to that of the capacitor 125, the function and effect of the present invention can be exhibited.

The reaction tank 101 contains 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,
Further, 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 dehydration reaction is provided. , 115, 117 and 121. 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 esterification reaction or the amidation reaction is connected via a pump 119 by a pipe 119. I have.

In the raw material storage tank 105, (meth)
Acrylic acid is easily polymerized. For example, methacrylic acid is polymerized by long-term storage or heat, so that a small amount of a polymerization inhibitor such as 0.1% by weight methoquinone is usually added to (meth) acrylic acid. I have. In FIG. 6, the circulation path 1 having an external jacket 150 (heat insulation means) using a pump 116 in order to always keep the temperature at 30 to 40 ° C.
51 are provided, and the (meth) acrylic acid raw material is always 30 to
The apparatus is configured so as to maintain the temperature at 40 ° C. and circulate so as not to polymerize.

The raw material storage tank 105, piping 115,
In order to prevent corrosion by corrosive (meth) acrylic acid, it is preferable that the inside of the pump 116 and the circulation path 151 be lined with a corrosion-resistant material such as a synthetic resin. Similarly, the catalyst storage tank 107, the pipe 117, and the pump 167 are also provided with a lining process using an acid-resistant material such as Teflon (trade name) or a synthetic resin such as vinyl chloride to prevent corrosion caused by an acid catalyst. Preferably used, pump 1
It is preferable to use a magnet pump for 67. The storage tank 109 for the polymerization inhibitor and the storage tanks 147 and 159 for the anti-gelling agent are provided with a stirring device (not shown). When dissolving the powdery polymerization inhibitor in a solvent, it is preferable to sufficiently stir and completely dissolve the polymerization inhibitor. However, the solution of the polymerization inhibitor or the anti-gelling agent which is not completely dissolved for some reason is supplied to the pump 16.
Pumping at 0, 169, 179 may cause the pump to block and stop. Such a situation cannot occur if the dissolution is sufficient, but the pump 160,
169 and 179 are preferably pumps that can continue the transfer without any delay even when a little slurry-like liquid is transferred. When transferring a polymerization inhibitor or an anti-gelling agent dissolved in a solvent, use Teflon or Viton (both are trade names).
It is preferable to use a pump sealed with a chemical resistant material such as. As a pump satisfying such conditions, it is optimal to provide an appropriate seal to a MONO pump (manufactured by Hyosinki Co., Ltd.). Further, a pipe 153 for collecting an esterified product synthesized in the reaction tank 101 by an esterification reaction is connected to a lower portion of the reaction tank 101.

In FIG. 6, a spray nozzle 126 is provided at the top of the condenser 125 in order to effectively exert the effects of the present invention.
Reference numeral 26 is connected to the anti-gelling agent storage tank 147 for storing the anti-gelling agent for preventing the distillate from gelling by a pipe 149 via a pump 179. Similarly, as shown in FIG. 7, near the connection between the reaction vessel 101 and the connection pipe 123, a spray nozzle 136 is provided from the connection pipe 123 side to the reaction vessel 10.
The spray nozzle 136 is provided so as to be sprayed toward one side, and the spray nozzle 136 is connected to the water separator 127 by a pipe 141.

A part of the circulating mechanism is to distill a distillate containing a dehydrating solvent from a solution containing an esterified product as a product in the system (in the reaction tank 101) after the dehydration reaction, It is also used as a circulation mechanism for removing distillate containing a dehydrating solvent out of the system after condensing and liquefying while preventing generation. In such a circulation mechanism, the water separator 12
7, a vacuum pump (ejector) 155 is attached via a pipe 157 to remove the dehydrated solvent by suction under reduced pressure. In the above embodiment, in order to sufficiently prevent gelation in the aqueous phase in the distillate, an aqueous solution in which a water-soluble polymerization inhibitor is dissolved is newly added to the spray nozzle 126 provided at the top of the condenser 125. A water-soluble anti-gelling agent storage tank 159 for storing (hereinafter, also simply referred to as “water-soluble anti-gelling agent”) is connected by a pipe 161.

In FIG. 6 described above, the dehydration reaction product is produced by the above-described apparatus configuration as described below. First, as a dehydration reaction step, pipes 113, 115, and 1 are supplied 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 into the reaction tank 101.
17, 119 and a pipe 141 through a pipe 145, a predetermined amount of each of a reaction raw material, alcohol and (meth) acrylic acid, an acid catalyst, a polymerization inhibitor and a dehydrating solvent are charged, and a reaction temperature and a jacket temperature appropriately set. ,
The esterification reaction or the amidation reaction is performed under reaction conditions such as pressure. As a result, the reaction water generated sequentially is supplied to the reaction tank 10.
It is azeotroped with the dehydrating solvent charged in 1 and is distilled through the connecting pipe 123. Distilled gas fluid,
That is, the distillate, which is a solvent-water azeotrope,
It is passed through 25 and condensed and liquefied. At this time, the capacitor 1
Since the liquid pool of the distillate is sufficiently prevented from being generated and accumulated on at least the surface of the upper tube sheet 174 and the lower tube sheet 175 which comes into contact with the distillate, the condenser 125 A gel-like material is prevented from being formed in the inside of the device. In FIG. 6, the spray nozzle 126 provided at the top of the condenser 125 from the anti-gelling agent storage tank 147 through the pipe 149 is used.
, A predetermined amount of an anti-gelling agent is continuously sprayed and brought into parallel contact with a gas fluid and a distillate that is a condensed and liquefied product.

Next, the condensed and liquefied distillate is passed through the pipe 129 from the lower part of the condenser 125 to the water separator 12.
7, and is separated into two layers of an aqueous phase and a solvent phase. Of this, the generated water in the lower part is
3 is sequentially drawn through a pipe 137 and stored in a produced water treatment tank 135. And processing tank 1
In 35, if necessary, it is chemically or biologically treated so as to satisfy the environmental standard (wastewater standard) value, and then is discharged to the outside of the present system through a pipe 139. On the other hand, in the water separator 127, the solvent phase containing the anti-gelling agent sprayed from the nozzle 126 overflows the partition 131 and is stored in the adjacent chamber 134. The solvent phase is supplied from a lower part of the chamber 134 to a pipe 141 by a pump 142.
And is returned to the reaction vessel 101 at a predetermined solvent circulation rate. At this time, a part of the spray nozzle 136 provided near the connection between the reaction tank 101 and the connection pipe 123 is provided.
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,
After the temperature is lowered, the internal temperature (liquid temperature) of the reaction vessel 101 becomes, for example, 60 ° C.
Until the temperature drops below, the outer jacket 1 of the reaction vessel 101
02, the temperature of the neutralizing agent storage tank 11 is adjusted while maintaining the temperature at or below a predetermined temperature.
A part of the acid catalyst and (meth) acrylic acid is partially neutralized by adding an aqueous alkali solution (neutralizing agent) diluted to a predetermined concentration with a large amount of water into the reaction tank 101 through the pipe 121 from the line 1. Will be.

After the neutralization step is completed, as a solvent distilling step, the temperature of the reaction vessel 101 is raised to a predetermined temperature through a heating medium (pressure steam) in the outer jacket 102 of the reaction vessel 101 under normal pressure. In addition to the dehydrating solvent and water added during the partial neutralization treatment, unreacted low-boiling-point raw materials such as (meth) acrylic acid are azeotropically distilled off through the connecting pipe 123. . The solvent-water azeotrope, which is a gaseous fluid that has been distilled, is passed through the condenser 125 to be condensed and liquefied. At this time, the capacitor 12
Thus, the formation of a gel-like substance inside the inside 5 is prevented.

The distillate condensed and liquefied in the solvent distillation step is treated in the same manner as the distillate condensed and liquefied in the dehydration reaction step. In the solvent distilling step, water enters the condenser 125 together with the solvent.
In order to prevent the polymerizable compound from gelling on the aqueous phase side, a predetermined amount of the water-soluble gelling agent is supplied from a spray nozzle 126 provided at the top of the condenser 125 through a pipe 161 from a water-soluble gelling agent storage tank 159. Preferably, the inhibitor is dropped continuously and brought into co-current contact with the distillate.

After the solvent distilling step, conditioned water is added into the reaction tank 101 from a water storage tank (not shown) or a water pipe (not shown) connected by a pipe (not shown). Thus, an aqueous solution of a desired dehydration reaction product is obtained. The obtained aqueous solution of the dehydration reaction product is collected (stored) from the pipe 153.

[0108]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. “Parts” means “parts by weight” unless otherwise specified, and “%” means “% by weight”.

Example 1 Production Example 1 of Dehydration Reaction Product [Esterification] A cylindrical type equipped with an outer jacket and having a thermometer, a stirrer, a produced water separator, and one vertical multi-tube heat exchanger (condenser) 36376 parts of methoxypoly (n = 25) ethylene glycol, 10760 parts of methacrylic acid, 1470 parts of a 70% aqueous solution of paratoluenesulfonic acid hydrate, 11 parts of phenothiazine and 2344 parts of cyclohexane were charged into a reaction vessel, and esterified at a reaction temperature of 115 ° C. The reaction was performed. As the reaction tank, a bale-shaped reaction tank having a column having an inner diameter of 3.0 m and a height of 3.8 m and having upper and lower elliptical curved surfaces (2 to 1) was used.
The capacity of the reactor is about 30 m ³ . The reaction tank has an external jacket that can be heated by steam or hot water, two retreating wings each having three blades (upper stage), a blade diameter of 1.05 m, a blade width of 0.12 m,
(Lower stage) A stirrer equipped with a blade diameter of 1.65 m and a blade width of 0.12 m) and a baffle bar, a flush valve at the bottom used for extracting a reaction solution, and a manhole and a material inlet at the top. . The material was SUS, and the inside of the reaction tank and the stirring device were glass lining. The reaction tank has a structure in which a connecting pipe having an inner diameter of 0.2 m can be connected to a position 1.15 m from the center of the reaction tank. A vertical fixed tube plate type heat exchanger was prepared and used as the condenser. The condenser is a bale type having an upper and lower elliptical curved surface (2 to 1) of a cylinder having a body (shell) inner diameter of 0.85 m and a height of 4.0 m. Baffle plate and 624 heat transfer tubes (tube outer diameter 24 mm, inner diameter 20 mm, length 3.5 m)
Equipped with etc. The heat transfer area is 161 m ² . Material is S
US304. In addition, the welded portion between the upper tube sheet surface and the heat transfer tube was polished so as to be flat, so that liquid accumulation did not occur. The condenser has a structure in which a solution of an anti-gelling agent can be sprayed on the top of the tower. The horizontal equivalent length of the connecting pipe connecting the reactor and the top of the condenser is 1.55.
m, and has a downward slope of 0.57 ° from the reaction tank side to the condenser side, and the distance from the center of the reaction tank to the center of the condenser is 2.7 m.

Separately, 1.1 parts of phenothiazine and 1087 parts of cyclohexane were mixed in a dissolving tank, and from the start of cyclohexane reflux (internal temperature of 107 ° C.) to the end of the esterification reaction, a hemopump at the top of the condenser (Hyojin equipment) Using a spray nozzle. In addition, cyclohexane was sprayed from a spray nozzle to the connection part of the reaction tank to prevent polymerization of methacrylic acid. It was confirmed that the esterification rate reached 99% in about 20 hours. The obtained esterification reaction solution was added to 50927 parts at a temperature of 65 ° C. or lower at 4.2 parts.
6030 parts of a 5% aqueous sodium hydroxide solution and 5269 parts of water were added to neutralize a part of p-toluenesulfonic 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, water 772 containing 2 parts of hydroquinone was fed to the top of the condenser.
The part was sprayed using a Mohno pump. In addition, steam was blown into the jacket of the connecting pipe from the upper part, and the drain and the steam were drawn out from the two lower outlets (reactor side and condenser side) to keep the temperature warm. After the cyclohexane was distilled off, the solution was cooled to obtain an aqueous solution of an esterified product (M1). The obtained water melt (M1) was transferred to a separately provided container. After the above operation was repeated for 80 batches, the inside of the condenser and the connection tube were inspected, but no gel was found. In addition, when the aqueous solution (M1) was examined by GPC, no peak of a high molecular weight substance considered as a gel precursor was confirmed.

Comparative Example 1 An aqueous solution of an esterified product (C) was prepared in the same manner as in Example 1 except that the welded portion between the upper tube sheet surface and the heat transfer tube was not polished.
1) was obtained. The obtained aqueous solution (C1) was transferred to a separately provided container. After the above operation was repeated for 80 batches, the condenser was inspected. As a result, a lump of gel was obstructing a part of the inlet of the tube.

Example 2 Production Example 1 of Cement Additive [Polymerization] Next, a glass-lined reaction vessel equipped with a thermometer, a stirrer, a dropping device, a nitrogen inlet tube, and a vertical multitubular heat exchanger (condenser) Was charged with 18122 parts by weight of water, and the inside of the reaction vessel was replaced with nitrogen gas while stirring, and the temperature of the water was heated to 80 ° C. under a nitrogen atmosphere. Further, an aqueous solution in which 29365 parts by weight of the aqueous solution of the monomer mixture (M1) obtained above was added to 223 parts by weight of mercaptopropionic acid and 1323 parts by weight of water was mixed with a static mixer T8-15-4P.
T (trade name, manufactured by Noritake Co., Ltd.), and the mixture was dropped into the reaction vessel over 4 hours. Simultaneously with the start of the dropping, 276 parts by weight of ammonium persulfate as a polymerization initiator was added to water 2205.
An aqueous solution dissolved in parts by weight was added dropwise over 5 hours. After the completion of the dropwise addition of the polymerization initiator, the reaction temperature was maintained at 80 ° C. for an additional hour to complete the polymerization reaction.
3660 parts by weight of aqueous sodium hydroxide solution and water 860
The mixture was neutralized to pH 7 by adding 8 parts by weight, and the weight average molecular weight (gel permeation chromatography (GPC))
20,000 in terms of polyethylene glycol; the same applies hereinafter) to obtain a polymer aqueous solution (P1).

There was no high molecular weight peak in the GPC chart of the aqueous polymer solution (P1). In addition, an aqueous polymer solution (P
1) was taken on a transparent glass pin (200 ml) and the appearance was visually confirmed, but no gel was found, and no gel was accumulated in the strainer of the transfer pump.

Example 3 Use Example 1 of Cement Additive
Ment additive)Mortar test 1  Taiheiyo Cement Co., Ltd. ordinary Portland cement 4
00 parts and 800 parts of Toyoura standard sand, Hobart mortar
30 seconds with a mixer (Model No. N-50, manufactured by Tesco Corporation)
After kneading, a predetermined amount of the cement additive shown in Table 1 was weighed.
Add 260 parts of water diluted and kneaded for 3 minutes
Thus, a cement composition (mortar) was obtained. Profit
Mortar placed on a horizontal table 54m inside diameter
m, into a hollow cylinder with a height of 50 mm
Gently lift the cylinder vertically and spread it on the table
Measure the major axis and minor axis of the mortar,
And the flow rate.

Comparative Example 2 A mortar test was performed in the same manner as in Example 3 except that no cement additive was added. As shown in Table 1, the mortar flow value was smaller than that of Example 3,
In Example 3, it was found that the flowability was improved by adding the cement additive (P1).

[0116]

[Table 1]

Example 4 Production Example 2 of Dehydration Reaction Product [Esterification] A cylindrical type equipped with an outer jacket and having a thermometer, a stirrer, a produced water separator, and one vertical multi-tube heat exchanger (condenser) A reaction vessel was charged with 18000 parts of methoxypoly (n = 25) ethylene glycol, 3600 parts of methacrylic acid, 240 parts of paratoluenesulfonic acid-hydrate, 5 parts of phenothiazine and 1380 parts of cyclohexane, and the reaction temperature was 115 ° C.
To carry out an esterification reaction. The same reactor as in Example 1 was used.

Separately, 0.5 part of phenothiazine and 640 parts of cyclohexane are mixed in a dissolving tank, and from the beginning of refluxing cyclohexane (internal temperature of 107 ° C.) to the end of the esterification reaction, a hemopump at the top of the condenser (Hyojin) (Manufactured by Equipment Co., Ltd.). In addition, cyclohexane was sprayed from a spray nozzle to the connection part of the reaction tank to prevent polymerization of methacrylic acid. It was confirmed that the esterification rate reached 99% in about 40 hours. 2590 parts of a 4.2% aqueous sodium hydroxide solution and 2590 parts of water were added to the obtained esterification reaction solution at 65 ° C. or lower to neutralize a part of p-toluenesulfonic 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, 350 parts of water containing 1 part of hydroquinone was sprayed to the top of the condenser using a mono pump. The connecting pipe was kept warm in the same manner as in Example 1. After cyclohexane was distilled off, the mixture was cooled to obtain an aqueous solution of an esterified product (M2). The obtained aqueous solution (M2) was transferred to a separately provided container. After the above operation was repeated for 5 batches, the inside of the condenser and the connecting tube was inspected, but no gel was found.
The aqueous solution (M2) was examined with C. No high molecular weight peak, which is considered a gel precursor, was observed.

Comparative Example 3 Except that the weld between the upper tube sheet surface and the heat transfer tube was not polished,
An aqueous solution (C3) of an esterified product was obtained in the same manner as in Example 4. The obtained aqueous solution (C3) was transferred to a separately provided container. When the condenser was inspected after 5 batches of the above drying operation, a small lump of gel was adhered to a part of the inlet of the tube.

Example 5 Production Example 2 of Cement Additive [Polymerization] Next, a glass-lined reaction vessel equipped with a thermometer, a stirrer, a dropping device, a nitrogen inlet tube, and a vertical multi-tube heat exchanger (condenser) Was charged with 8270 parts by weight of water, and while stirring, the inside of the reaction vessel was replaced with nitrogen gas, and the temperature of the water was heated to 80 ° C. under a nitrogen atmosphere. Further, an aqueous solution obtained by adding 13430 parts by weight of the monomer mixture aqueous solution (M2) obtained above to 600 parts by weight of water to 97 parts by weight of mercaptopropionic acid and a static mixer T8-15-4PT (trade name, manufactured by Noritake Co., Ltd.) The mixture was added dropwise over 4 hours into the reaction vessel while mixing, and simultaneously with the start of the addition, an aqueous solution in which 125 parts by weight of ammonium persulfate was dissolved in 1000 parts by weight of water was added dropwise over 5 hours. After the addition of the polymerization initiator is completed, the reaction temperature is further increased to 80 ° C. for 1 hour.
And the reaction solution was neutralized to pH 7 by adding 1060 parts by weight of a 49% aqueous sodium hydroxide solution and 3700 parts by weight of water, and the weight average molecular weight was 200.
A polymer aqueous solution (P2) was obtained.

There was no high molecular weight peak in the GPC chart of the aqueous polymer solution (P2). In addition, an aqueous polymer solution (P
2) was taken on a transparent glass pin (200 ml) and the appearance was visually confirmed, but there was no gel, and no gel was accumulated on the strainer of the transfer pump.

Example 6 Use Example 2 of Cement Additive
Ment additive)Mortar test 2  Taiheiyo Cement Corp. ordinary Portland cement 8
00 parts and 400 parts of Toyoura standard sand, Hobart mortar
30 seconds with a mixer (Model No. N-50, manufactured by Tesco Corporation)
After kneading, a predetermined amount of the cement additive shown in Table 2 was weighed.
Add 200 parts diluted with water and knead for 3 minutes
Thus, a cement composition (mortar) was obtained. Profit
Mortar placed on a horizontal table 54m inside diameter
m, into a hollow cylinder with a height of 50 mm
Gently lift the cylinder vertically and spread it on the table
Measure the major axis and minor axis of the mortar and calculate the average value.
And the flow rate.

Comparative Example 4 A mortar test was performed in the same manner as in Example 6, except that no cement additive was added. As shown in Table 2, the mortar flow value was smaller than that in Example 6,
It was found that in Example 6, the flowability was improved by adding the cement additive (P2).

[0124]

[Table 2]

[0125]

The method for producing a dehydration reaction product of the present invention comprises:
With the above-described configuration, it is possible to sufficiently suppress the occurrence of inconvenience in the manufacturing process and the deterioration of the performance and quality of various chemical products. In addition, the polymer produced from the obtained dehydration reaction product is suitably applied as a raw material for producing a cement additive, calcium carbonate, carbon black, a pigment dispersant such as ink, a scale inhibitor, gypsum /
It can be used as a raw material for producing chemical products such as a water slurry dispersant, a coal / water slurry (CWM) dispersant, and a thickener.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an embodiment of a dehydration reaction apparatus according to the present invention, which includes a water separator together with a reaction tank and a condenser.

FIG. 2 is a conceptual diagram showing one embodiment of a vertical multitubular heat exchanger according to the present invention.

FIG. 3 is a conceptual diagram showing one embodiment of a vertical multitubular heat exchanger according to the present invention.

FIG. 4 is a conceptual diagram illustrating a lid of a vertical multitubular heat exchanger according to the present invention.

FIG. 5 is a conceptual diagram showing one embodiment of a conventional vertical multitubular heat exchanger.

FIG. 6 is a conceptual diagram showing one embodiment of an apparatus configuration used in the method for producing a dehydration reaction product of the present invention.

FIG. 7 shows an embodiment of a spray nozzle provided near a connection portion between a reaction tank and a connection portion and a spray nozzle provided in a condenser used in the method for producing a dehydration reaction product of the present invention. FIG.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 extra-fluid inlet 2 extra-fluid outlet 3 intra-fluid inlet 4 intra-fluid outlet 5, 174 upper tube sheet 6, 175 lower tube sheet 7 head cover 8 rear cover 9, 173 heat transfer tube 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 Neutralizer storage tank 113, 115, 117, 119, 121, 130, 1
37, 139, 141, 145, 149, 153, 15
7, 161 Piping 116, 160, 167, 169, 179 Pump 123 Connecting pipe 124 Heat retaining double pipe 125, 128 Condenser 126, 136 Spray nozzle 127 Water separator 129 Supply pipe (piping) 131 Partition plate 133, 134 Water separation Internal chamber 135 Reacted water treatment tank 142 Circulation pump 143 Dehydration solvent storage tank 144 Flow meter 147 Anti-gelling agent storage tank 151 Circulation path 155 Vacuum pump 159 Water-soluble anti-gelling agent storage tank

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor, Tsukasa Yuasa 5-8 Nishiburi-cho, Suita-shi, Osaka F-term in Nippon Shokubai Co., Ltd. (Reference) 3L065 CA12 4G075 AA14 AA15 AA45 AA62 BA10 BB02 BB08 BD03 BD15 CA02 EA06 EB21 EC07

Claims (4)

[Claims] In producing a dehydration reaction product applied to the production of a polymer for a cement additive from a reaction solution,
A method for producing a dehydration reaction product, comprising a dehydration reaction step comprising essentially using a vertical multitubular heat exchanger for exchanging heat between a distillate from the reaction solution and an extracellular fluid, The shell-and-tube heat exchanger has a body having an extra-fluid inlet and an extra-fluid outlet, lids provided at upper and lower ends of the body, and tube plates provided near upper and lower ends of the interior of the body. It has a structure that requires a plurality of heat transfer tubes connected between the tube sheets, and that there is substantially no stagnation portion of the distillate at a connection portion between the tube sheets and the heat transfer tubes. A method for producing a dehydration reaction product characterized by the following. 2. A method for producing a dehydration reaction product applied to the production of a polymer for cement additives from a reaction solution,
A method for producing a dehydration reaction product, comprising a dehydration reaction step comprising essentially using a vertical multitubular heat exchanger for exchanging heat between a distillate from the reaction solution and an extracellular fluid, The multi-tubular heat exchanger has a body having an extra-fluid inlet and an extra-fluid outlet, lids provided at upper and lower ends of the body, and tube plates provided near upper and lower ends inside the body. A plurality of heat transfer tubes connected between the tube sheets. A method for producing a dehydration reaction product, wherein substantially no protrusion of a heat tube is present. 3. The method for producing a dehydration reaction product according to claim 1, wherein the reaction solution contains (meth) acrylic acid and / or an ester thereof. 4. When a dewatering reaction is carried out by exchanging heat between a distillate and an extrafluid by the vertical multitubular heat exchanger, a gelling inhibitor is caused to act on the distillate. The method for producing a dehydration reaction product according to claim 1, 2, or 3.