Reaction apparatus, production method of vinyl polymer, and method for producing vinyl polymer

Abstract

To provide a reaction apparatus for preventing a surface of an inner wall or an inner structure of a suspension polymerization reaction vessel of a monomer mixture composed of mainly a vinyl chloride monomer, or a vinyl chloride compound from depositing a scale of a polymer.SOLUTION: A batch-type reaction apparatus used for producing a polymer by suspension polymerization using a dispersant assistant includes a reactor having a cylindrical straight body part, a plurality of first cooling pipes disposed in the reactor for flowing a coolant, and a stirring shaft disposed in the reactor, fixed with a stirring blade, and configured so as to rotate. Respective representative points of the plurality of first cooling pipes on a plane approximately vertical to an extending direction of the straight body part position substantially on any circle of a plurality of virtual circles disposed approximately concentrically on a plane approximately vertical. A ratio CZ (mg-dispersant assistant / kg-monomer) of a number Nc of the plurality of virtual circles to a mass of the dispersant assistant to a mass of one or more monomers to be a raw material of the polymer satisfies a specific relation.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a reaction apparatus, a method for producing a vinyl polymer, and a method for producing a vinyl polymer.

Background Art

[0002] Patent Document 1 discloses a polymerization apparatus including a baffle and a serpentine pipe through which a refrigerant can flow inside. Patent Document 2 discloses a polymerization apparatus including a baffle and a coiled cooling pipe through which a refrigerant can flow inside. Patent Document 3 discloses a resin synthesis apparatus including a baffle through which a heat medium can flow inside and a stirring means having a helical ribbon blade and an anchor blade. [Prior Art Documents] [Patent Documents] [Patent Document 1] Japanese Patent Laid-Open No. 7-233202 [Patent Document 2] Japanese Patent Laid-Open No. 7-233206 [Patent Document 3] Japanese Patent Laid-Open No. 2013-151621

Summary of the Invention

[0003] In a first aspect of the present invention, a reaction apparatus is provided. The above reaction apparatus is used, for example, for producing a polymer by suspension polymerization using a dispersion aid. The above reaction apparatus is, for example, a batch reaction apparatus. The above reaction apparatus includes, for example, a reactor having a cylindrical straight body portion. The above reaction apparatus includes, for example, a plurality of first cooling pipes arranged inside the reactor for flowing a refrigerant. The above reaction apparatus includes, for example, a stirring shaft arranged inside the reactor, to which a stirring blade is attached and which is configured to be rotatable.

[0004] In the above-described reactor, each representative point of the plurality of first cooling pipes on a plane substantially perpendicular to the extending direction of the straight cylindrical portion is located, for example, on the circumference of any one of a plurality of virtual circles arranged substantially concentrically on the substantially perpendicular plane. In the above-described reactor, when the number Nc [pieces] of the plurality of virtual circles is 1, 2, or 3, the number Nc [pieces] of the plurality of virtual circles and the ratio CZ [mg - dispersing aid / kg - monomer] of the mass of the dispersing aid to the mass of one or more types of monomers that are raw materials of the polymer satisfy, for example, the relationship shown in the following mathematical formula A1. (Mathematical formula A1) 15Nc + 300 < CZ < 175Nc + 2000

[0005] In any of the above-described reactors, when the number Nc of the plurality of virtual circles is 4 or more, the ratio CZ [mg / kg] may satisfy the relationship shown in the following mathematical formula A2. (Mathematical formula A2) 15×3 + 300 < CZ < 175×3 + 2000

[0006] In any of the above-described reactors, when the number Nc [pieces] of the plurality of virtual circles is 1, 2, or 3, the number Nc [pieces] and the ratio CZ [mg - dispersing aid / kg - monomer] may satisfy the relationship shown in the following mathematical formula B1. (Mathematical formula B1) 15Nc + 310 < CZ < 175Nc + 1550

[0007] In any of the above-described reactors, when the number Nc [pieces] of the plurality of virtual circles is 1, 2, or 3, the number Nc [pieces] and the ratio CZ [mg - dispersing aid / kg - monomer] may satisfy the relationship shown in the following mathematical formula C1. (Mathematical formula C1) 15Nc + 400 < CZ < 175Nc + 1850

[0008] In any of the above-described reactors, when the number Nc [pieces] of the plurality of virtual circles is 1, 2, or 3, the number Nc [pieces] and the ratio CZ [mg - dispersing aid / kg - monomer] may satisfy the relationship shown in the following mathematical formula D1. (Mathematical formula D1) 15Nc + 400 < CZ < 175Nc + 1550

[0009] Any of the above reaction apparatuses may be provided with a dispersion aid input section for inputting a dispersion aid into the interior of the reactor. In any of the above reaction apparatuses, when the number Nc [pieces] of a plurality of virtual circles is 1, 2, or 3, the dispersion aid may be input so that the number Nc [pieces] and the ratio CZ [mg - dispersion aid / kg - monomer] satisfy the relationship shown in the above formula A1, formula B1, formula C1, or formula D1.

[0010] In a second aspect of the present invention, a reaction apparatus is provided. The above reaction apparatus is used, for example, for producing a polymer by suspension polymerization using a dispersion aid. The above reaction apparatus is, for example, a batch - type reaction apparatus. The above reaction apparatus includes, for example, a reactor having a cylindrical straight body portion. The above reaction apparatus includes, for example, a plurality of first cooling pipes arranged inside the reactor for circulating a refrigerant. The above reaction apparatus includes, for example, a stirring shaft arranged inside the reactor, to which one or more stirring blades are attached and which is configured to be rotatable. The above reaction apparatus includes, for example, a dispersion aid input section for inputting a dispersion aid into the interior of the reactor.

[0011] In the above reaction apparatus, each representative point of the plurality of first cooling pipes on a plane substantially perpendicular to the extending direction of the straight body portion is located, for example, on the circumference of any of a plurality of virtual circles that are substantially concentrically arranged on the substantially perpendicular plane. In the above reaction apparatus, when the number Nc [pieces] of a plurality of virtual circles is 1, 2, or 3, the dispersion aid input section inputs the dispersion aid so that the number Nc [pieces] of the plurality of virtual circles and the ratio CZ [mg - dispersion aid / kg - monomer] of the mass of the dispersion aid to the mass of one or more types of monomers that are raw materials of the polymer satisfy the relationship shown in the following formula A1. (Formula A1) 15Nc + 300 < CZ < 175Nc + 2000

[0012] In any of the reactors according to the above-described first or second aspect, the stirring shaft may be configured such that a plurality of stirring blades can be attached at different positions in the extending direction of the stirring shaft. In any of the above reactors, the dimension of the straight cylindrical portion, the dimension of at least one of the plurality of stirring blades, and the set value of the rotational speed of the stirring shaft may satisfy the relationship shown in the following formula (1). (Formula 1) N(b / d)(L / D) / n ≦ 6.0 In Formula 1, N represents the number of the plurality of stirring blades, b represents the maximum value [m] of the blade widths of the plurality of stirring blades, d represents the maximum value [m] of the blade diameters of the plurality of stirring blades, L represents the length [m] in the extending direction of the straight cylindrical portion, D represents the maximum value [m] of the diameters of a plurality of inscribed circles that are substantially inscribed in the straight cylindrical portion in each of the cross-sections formed by a plurality of planes, which are planes perpendicular to the extending direction of the straight cylindrical portion and pass through the respective attachment positions of the plurality of stirring blades, when the straight cylindrical portion is cut by the plurality of planes, and n represents the set value of the rotational speed [rps] of the stirring shaft.

[0013] In any of the above reactors, each of the plurality of first cooling pipes may have a meandering portion that extends while repeatedly bending. In any of the above reactors, the meandering portion may include a plurality of extending portions that extend linearly or extend in a curved manner. In any of the above reactors, the meandering portion may include a plurality of bending portions that connect the ends of two adjacent extending portions among the plurality of extending portions.

[0014] In any of the above reactors, each of the plurality of first cooling pipes may include a plurality of ring portions having a ring shape. In any of the above reactors, each of the plurality of first cooling pipes may include one or more connecting portions that connect the plurality of ring portions.

[0015] Any of the above reactors may include a plurality of baffles that extend substantially parallel to the extending direction of the straight cylindrical portion. Any of the above reactors may include a second cooling pipe that is disposed inside at least one of the plurality of baffles and through which a refrigerant flows.

[0016] In a third aspect of the present invention, a method for producing a vinyl polymer is provided. The method for producing a vinyl polymer described above has, for example, a step of polymerizing a vinyl monomer using any of the reaction apparatuses according to the first or second aspect described above to produce a vinyl polymer.

[0017] In a fourth aspect of the present invention, a method for producing a vinyl polymer is provided. The method described above is, for example, a method for producing a vinyl polymer by suspension polymerization using a batch reactor.

[0018] In the method described above, the reaction apparatus includes, for example, a reactor having a cylindrical straight body portion. In the method described above, the reaction apparatus includes, for example, a plurality of first cooling pipes arranged inside the reactor for circulating a refrigerant. In the method described above, the reaction apparatus includes, for example, a stirring shaft arranged inside the reactor, to which a stirring blade is attached and which is configured to be rotatable. In the method described above, each representative point of the plurality of first cooling pipes in a plane substantially perpendicular to the extending direction of the straight body portion is located, for example, on the circumference of any of a plurality of virtual circles arranged substantially concentrically in the substantially perpendicular plane.

[0019] The method described above has, for example, a raw material charging step of charging a vinyl monomer, an aqueous medium, and a dispersion aid into the reactor. The method described above has, for example, a polymerization step of polymerizing a vinyl monomer to produce a vinyl polymer. In the method described above, the raw material charging step includes, for example, a step of charging a dispersion aid such that when the number Nc [pieces] of the plurality of virtual circles is 1, 2, or 3, the number Nc [pieces] of the plurality of virtual circles and the ratio CZ [mg-dispersion aid / kg-monomer] of the mass of the dispersion aid to the mass of the vinyl monomer satisfy the relationship shown in the following mathematical formula A1. (Mathematical formula A1) 15Nc + 300 < CZ < 175Nc + 2000

[0020] In the above method, in the raw material input stage, when the number Nc [pieces] of a plurality of virtual circles is 1, 2, or 3, the raw material input stage may include a stage of inputting a dispersion aid so that the number Nc and the ratio CZ satisfy the relationships shown in the following mathematical formulas B1, C1, or D1. (Mathematical formula B1) 15Nc + 310 < CZ < 175Nc + 1550 (Mathematical formula C1) 15Nc + 400 < CZ < 175Nc + 1850 (Mathematical formula D1) 15Nc + 400 < CZ < 175Nc + 1550

[0021] In the above method, in the raw material input stage, when the number Nc of a plurality of virtual circles is 4 or more, the raw material input stage may include a stage of inputting a dispersion aid so that the ratio CZ [mg-dispersion aid / kg-monomer] satisfies the relationship shown in the following mathematical formula A2. (Mathematical formula A2) 15×3 + 300 < CZ < 175×3 + 2000

[0022] Note that the above summary of the invention does not list all the necessary features of the present invention. Also, sub-combinations of these feature groups can also be inventions.

Brief Description of the Drawings

[0023]

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Mode for Carrying Out the Invention

[0024] Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the invention according to the claims. Also, not all combinations of the features described in the embodiments are essential for the solution means of the invention. In this specification, when a numerical range is expressed as "A to B", this expression means A or more and B or less.

[0025] According to the present embodiment, in a reaction apparatus including a reactor having a cylindrical straight body portion, a stirring shaft, and a plurality of stirring blades, an example of a procedure for controlling or determining the rotational speed of the stirring shaft will be described. In one embodiment of the procedure for controlling or determining the rotational speed of the stirring shaft, a procedure specific to the case where a plurality of cooling pipes are arranged in multiple layers in the radial direction of the inscribed circle of the straight body portion inside the reactor will be described.

[0026] Further, according to the present embodiment, an example of a procedure for producing a polymer by suspension polymerization using a dispersion aid is described using a reaction apparatus including a reactor having a cylindrical straight body portion and a stirring shaft to which one or more stirring blades are attached. In an example of the procedure for producing a polymer by suspension polymerization using a dispersion aid, a procedure specific to the case where a plurality of cooling pipes (sometimes referred to as cooling pipes) are arranged in multiple layers in the radial direction of the inscribed circle of the straight body portion inside the reactor will be described.

[0027] Therefore, first, with reference to FIGS. 1 to 16, the structure of the reaction apparatus according to the above-described embodiment will be described. Further, with reference to FIG. 17, the details of the procedure for controlling or determining the rotational speed of the stirring shaft will be described. Furthermore, with reference to FIG. 18, an example of the attachment positions of the plurality of stirring blades on the stirring shaft will be described. Also, with reference to FIG. 19, an example of the procedure for producing a polymer by suspension polymerization using a dispersion aid will be described.

[0028] (Outline of Polymerization Apparatus 100) With reference to FIGS. 1, 2, 3, and 4, details of an example of the polymerization apparatus 100 will be described. The polymerization apparatus 100 is used, for example, in the production of polymers. The polymerization apparatus 100 may be used for suspension polymerization applications.

[0029] More specifically, the polymerization apparatus 100 is used for the production of vinyl polymers. As a method for producing a vinyl polymer, a method having a step of polymerizing a vinyl monomer using the polymerization apparatus 100 to produce a vinyl polymer is exemplified. The above method for producing a vinyl polymer has, for example, a step of storing a raw material containing a vinyl monomer in a reactor arranged in the polymerization apparatus 100. The above method for producing a vinyl polymer has, for example, a step of initiating the polymerization reaction of the above vinyl monomer to produce a vinyl polymer.

[0030] FIG. 1 shows a schematic cross-sectional view of an example of the polymerization apparatus 100. In the present embodiment, the polymerization apparatus 100 includes a reaction vessel 110, a stirrer 120, one or more (sometimes simply referred to as one or more) baffles 130, one or more serpentine cooling pipes 140, one or more serpentine cooling pipes 150, a jacket 170, and a reflux condenser 180. In the present embodiment, the stirrer 120 has a stirring shaft 122, a stirring blade 124, and a power mechanism 126. In the present embodiment, the baffle 130 has a main body 132 and one or more supports 134. In the present embodiment, the jacket 170 has a flow path 172 for a heat medium. In the present embodiment, the reflux condenser 180 has a flow path 182 for a heat medium.

[0031] In the present embodiment, the stirring shaft 122 and the stirring blade 124 are arranged inside the reaction vessel 110. In the present embodiment, each of the one or more baffles 130 is arranged inside the reaction vessel 110. In the present embodiment, each of the one or more serpentine cooling pipes 140 is arranged inside the reaction vessel 110. In the present embodiment, each of the one or more serpentine cooling pipes 150 is arranged inside the reaction vessel 110.

[0032] In the present embodiment, the power mechanism 126 is arranged outside the reaction vessel 110. In the present embodiment, the jacket 170 is arranged outside the reaction vessel 110. In the present embodiment, the reflux condenser 180 is arranged outside the reaction vessel 110.

[0033] In the present embodiment, the meandering cooling pipes 140 and 150 are arranged such that the distances from the inner surface of the reaction vessel 110 are different. Specifically, the meandering cooling pipe 150 is arranged at a position closer to the side surface of the reaction vessel 110 than the meandering cooling pipe 140. In this case, the distance P C2 between the meandering cooling pipe 140 and the side surface of the reaction vessel 110 C1 is greater than the distance P

[0034] between the meandering cooling pipe 150 and the side surface of the reaction vessel 110. C2 The distance P between the meandering cooling pipe 140 and the side surface of the reaction vessel 110 C1 may be the minimum value of the distance between the center of the cross-section of the meandering cooling pipe 140 and the side surface of the reaction vessel 110. The distance P between the meandering cooling pipe 150 and the side surface of the reaction vessel 110

[0035] may be the minimum value of the distance between the center of the cross-section of the meandering cooling pipe 150 and the side surface of the reaction vessel 110. For example, when the meandering cooling pipe 140 or 150 is a circular pipe, the cross-section of the meandering cooling pipe 140 or 150 is circular, and the center of the cross-section of the meandering cooling pipe 140 or 150 is the center of the circle.

[0035] Accordingly, according to the present embodiment, the heat inside the reaction vessel 110 can be efficiently removed. For example, when the polymerization apparatus 100 is used for the production of a polymer, the polymerization apparatus 100 can efficiently remove the reaction heat generated in the polymerization reaction.

[0036] Incidentally, particularly in the suspension polymerization of vinyl chloride monomers or monomer mixtures mainly composed of vinyl chloride compounds (both may be collectively referred to as vinyl chloride monomers), when internal structures such as cooling coils and draft tubes are arranged inside the reaction vessel 110, the required power of the stirrer 120 increases. In addition, the shape, size, and installation position of the above internal structures affect the mixing performance of the polymerization apparatus 100. Therefore, depending on the internal structure, slow-flowing parts may occur inside the reaction vessel 110. When slow-flowing parts occur inside the reaction vessel 110, the temperature inside the reaction vessel 110 becomes non-uniform. As a result, the particle size and / or degree of polymerization of the produced polymer become non-uniform, or polymer scale easily adheres to the inner wall of the reaction vessel 110 or the surface of the internal structure. The above scale can cause fish eyes that impair the quality of molded products using the polymer.

[0037] Also, under the condition of the same heat removal efficiency, the enlargement of the reaction vessel 110 and the shortening of the reaction time are in a trade-off relationship. Therefore, in order to enlarge the reaction vessel 110 while shortening the reaction time, it is desirable to increase the heat removal efficiency of the polymerization apparatus 100.

[0038] As a method of increasing the heat removal efficiency of the polymerization apparatus 100, it is conceivable to lower the temperature of the refrigerant. However, when the temperature of the refrigerant is lowered, the production cost of the polymer increases. As another method of increasing the heat removal efficiency of the polymerization apparatus 100, it is conceivable to increase the amount of heat removed by the jacket 170 or the reflux condenser 180. In particular, when it becomes a large polymerization vessel of 40 m 3 or more, since the amount of heat removed by only the heat removal by the jacket 170 is insufficient, it is conceivable to greatly increase the amount of heat removed by the reflux condenser 180. However, when the heat removal load of the reflux condenser 180 is increased, the amount of foaming of the polymer slurry inside the reaction vessel 110 may increase. When the amount of foaming of the polymer slurry increases, the heat removal capacity of the reflux condenser 180 may decrease, or polymer scale may adhere to the inside of the reflux condenser 180.

[0039] In addition, for example, when the capacity of the polymerization vessel is increased using the polymerization vessel described in Patent Document 1, if the heat transfer area of ​​the serpentine pipe is insufficient, it may be difficult to shorten the reaction time while maintaining the quality of the product. On the other hand, in the polymerization vessel described in Patent Document 2, the heat transfer area can be increased by a relatively simple structure. However, due to the structure of the vessel, the baffle and the coiled cooling tube cannot be arranged on approximately the same circumference. Therefore, the ratio of the area in which the coiled cooling tube can be installed to the capacity of the vessel is relatively small. When the capacity of the polymerization vessel is increased using the polymerization vessel described in Patent Document 2, if the distance between the coiled cooling tubes is reduced to increase the heat transfer area, the mixing performance of the polymerization vessel may decrease. In addition, if scale or clumped reactants are generated on the surface of the coiled cooling tube due to disturbances, etc., the work inside the vessel becomes complicated, making it difficult to sufficiently remove the scale, etc.

[0040] In contrast, according to the polymerization apparatus 100 of this embodiment, the serpentine cooling pipe 140 and the serpentine cooling pipe 150 are arranged so that the distances from the inner surface of the reaction vessel 110 are different. This allows the heat transfer area to be increased using a relatively simple structure that has little effect on the mixing performance of the polymerization apparatus 100. In addition, according to the polymerization apparatus 100 of this embodiment, the degree of freedom regarding the installation positions of the serpentine cooling pipe 140 and the serpentine cooling pipe 150 is large. For example, at least one of the one or more serpentine cooling pipes 140 and the one or more serpentine cooling pipes 150 and the baffle 130 can be arranged on approximately the same circumference. This allows the heat transfer area of ​​the entire apparatus to be increased while further reducing the effect of the serpentine cooling pipe 150 on the mixing performance of the polymerization apparatus 100.

[0041] (Overview of each part of the polymerization apparatus 100) In this embodiment, the reaction vessel 110 stores raw materials for a synthesis reaction. When the polymerization apparatus 100 is used for producing a polymer, for example, a polymerizable monomer, a polymerization initiator, an aqueous medium, a dispersion aid, and the like are charged into the reaction vessel 110, and then polymerization is initiated. As the dispersion aid, for example, any surfactant can be used.

[0042] The reaction vessel 110 has, for example, a cylindrical shape. The reaction vessel 110 may have a cylindrical shape or a rectangular prism shape. The reaction vessel 110 is installed, for example, such that the extending direction of the reaction vessel 110 (the z direction in the figure) is vertical. The reaction vessel 110 includes, for example, a straight body portion and a mirror portion. In the figure, the total length in the extending direction of the reaction vessel 110 is denoted as H.

[0043] Examples of the shape of the cross section (which may be referred to as a cross-sectional shape) obtained by cutting the reaction vessel 110 with a plane perpendicular to the extending direction of the reaction vessel 110 (the xy plane in the figure) include a circular shape, an elliptical shape, and a polygonal shape. Note that the cross-sectional shape of the reaction vessel 110 may be a shape that can be substantially regarded as a circular shape, an elliptical shape, or a polygonal shape.

[0044] The internal volume of the reaction vessel 110 is not particularly limited, but the internal volume of the reaction vessel 110 is, for example, 1 to 300 m 3 It is. The lower limit value of the internal volume of the reaction vessel 110 may be 40 m 3 It may be, 80 m 3 It may be, 100 m 3 It may be, 120 m 3 It may be, 130 m 3 It may be, 150 m 3 It may be, 200 m 3 It may be, 250 m 3 It may be. The upper limit value of the internal volume of the reaction vessel 110 may be 300 m 3 Or more. The upper limit value of the internal volume of the reaction vessel 110 may be 350 m 3 It may be, 400 m 3 It may be. The larger the internal volume of the reaction vessel 110, the more advantageously the improvement in the cooling capacity according to the present embodiment can act.

[0045] The internal capacity of the reaction vessel 110 is determined as the capacity when the reaction vessel 110 stores liquid up to a predetermined upper limit position of the reaction vessel 110. The internal capacity of the reaction vessel 110 is, for example, the internal volume of the reaction vessel 110 when no internal structure such as a stirring shaft, blades, baffles, coils, etc. is disposed inside the reaction vessel 110.

[0046] As described above, there is a trade-off between increasing the size of the reaction vessel 110 and shortening the reaction time. 3 If the internal volume of the reaction vessel 110 is more than 80 m, the heat removal efficiency of the polymerization apparatus 100 becomes insufficient, and it becomes difficult to shorten the reaction time while increasing the size of the reaction vessel 110. 3 In the above cases, the effects of the polymerization apparatus 100 according to this embodiment are more pronounced. The details of the reaction vessel 110 will be described later.

[0047] In this embodiment, the agitator 120 agitates the liquid stored inside the reaction vessel 110. In this embodiment, the agitator shaft 122 holds the agitator blade 124 and rotates the agitator blade 124. In this embodiment, the agitator blade 124 is attached to the agitator shaft 122 and agitates the liquid stored inside the reaction vessel 110.

[0048] The shape of the agitating blade 124 is not particularly limited, but examples of the shape of the agitating blade 124 include Pfaudle blades, blue margin blades, paddle blades, inclined paddle blades, turbine blades, propeller blades, and combinations thereof. As a result, when the agitating shaft 122 rotates, a discharge flow is generated that radially moves from the agitating shaft 122 toward the outer periphery. The number of blades that the agitating blade 124 has is not particularly limited, but examples of the number of blades are 2 to 6. The installation position and the installation number of the agitating blades 124 are not particularly limited, but it is preferable that the agitating blades 124 are installed in multiple stages. Examples of the number of stages of the agitating blades 124 are 2 to 6 stages.

[0049] In this embodiment, the power mechanism 126 rotates the stirring shaft 122. The power mechanism 126 includes, for example, a power unit (not shown) that generates power and a power transmission unit (not shown) that transmits the power generated by the power unit to the stirring shaft 122. Examples of the power unit include an electric motor. Examples of the power transmission unit include a speed reducer.

[0050] The rotation speed of the stirring shaft 122, as well as the shape, size, number of blades, installation position, installation quantity, and installation interval C of the stirring blades 124 i are appropriately determined according to the use of the polymerization apparatus 100. The rotation speed of the stirring shaft 122, as well as the shape, size, number of blades, installation position, installation quantity, and installation interval C of the stirring blades 124 i are determined in consideration of, for example, the internal volume of the reaction vessel 110, the shape of the reaction vessel 110, the internal structures arranged inside the reaction vessel 110, the configuration of the heat removal means, the heat removal capacity, and the composition of the raw materials charged for polymerization.

[0051] For example, when the polymerization apparatus 100 is used for suspension polymerization, the stirring energy applied to the content (in this case, an aqueous suspension mixture) is 80 - 200 kgf·m / s·m 3 and the rotation speed of the stirring shaft 122 is determined accordingly. Here, the "stirring energy" applied to the content is the net energy required for stirring per unit amount (sometimes referred to as the unit internal volume) of the content, obtained by subtracting various energy losses B such as motor efficiency, conduction loss, and mechanical loss from the energy A loaded on the drive motor for the stirrer arranged in the power mechanism 126 during the operation of the polymerization apparatus 100. Examples of the above unit amount include unit mass, unit volume, etc. For example, if the volume of the content is C, the stirring energy is calculated by the following formula E. (Formula E) (A - B) / C [kgf·m / s·m 3

[0052] ​The energy loaded on the drive motor for the stirrer can be electrically measured using a measuring instrument such as a wattmeter. Also, the stirring energy can be easily adjusted by changing the rotation speed of the stirring shaft 122.

[0053] The rotation speed of the stirring shaft 122 is set, for example, to 10 to 1000 [rpm]. The above set value can be preferably adopted, for example, when the polymerization apparatus 100 is used for suspension polymerization applications. As a method for determining the rotation speed of the stirring shaft 122 so that the stirring energy is within the above numerical range, (i) a method by a scale-up test, (ii) a method using a relational expression such as an experimental formula or an empirical formula, etc. are exemplified.

[0054] In one embodiment, the rotation speed of the stirring shaft 122 in the polymerization apparatus 100 is determined based on, for example, a polymerization test in a pilot plant carried out in advance. Generally, the scale-up from the pilot plant to the polymerization apparatus 100 is carried out so that the stirring state of the polymerization apparatus 100 and the stirring state of the pilot plant are substantially the same. For example, in the pilot plant and the polymerization apparatus 100, the shape and size of the reaction vessel 110 and the shape, size, and arrangement of internal structures such as the stirring blade 124, the baffle 130, the serpentine cooling pipe 140, and the serpentine cooling pipe 150 are determined so as to be similar.

[0055] Therefore, according to one embodiment, the rotation speed of the stirring shaft 122 in the polymerization apparatus 100 can be determined so that the stirring energy in the polymerization apparatus 100 and the stirring energy in the pilot plant are substantially the same. As described above, the stirring energy is calculated, for example, as "(A - B) / C". As a method for determining the rotation speed of the stirring shaft 122 based on the stirring energy, any known method can be adopted.

[0056] The rotational speed of the stirring shaft 122 in the pilot plant is determined, for example, by the following procedure. For example, through a polymerization test using the pilot plant, the relationship between the rotational speed of the stirring shaft 122 in the pilot plant and the quality of the polymer can be obtained. Thereby, the rotational speed of the stirring shaft 122 at which a polymer of the desired quality can be obtained is determined. The above quality is not particularly limited, but examples of the above quality include, for example, particle size.

[0057] Specifically, in the polymerization test using the pilot plant, the polymerization temperature is set according to the reduced viscosity of the target polymer (which may be referred to as the K value). Here, there is a correlation between the polymerization temperature and the average degree of polymerization of the polymer, and the K value of the polymer is widely used as an index representing the average degree of polymerization of the polymer.

[0058] Also, in the polymerization test using the pilot plant, the polymerization time is determined according to the heat removal capacity of the pilot plant. For example, the polymerization time is determined so that the heat generation amount by the reaction does not exceed the heat removal capacity of the pilot plant according to (i) the charged amount of the monomer as the starting material, (ii) the input amount of the polymerization initiator, and (iii) the heat removal capacity of the pilot plant.

[0059] In this way, when the polymerization time is set so that the pilot plant has sufficient heat removal capacity, by setting the polymerization temperature according to the target value of the K value, a polymer having the desired average degree of polymerization can be produced. Therefore, for example, polymerization tests are carried out for each of a plurality of conditions where the polymerization temperature and the polymerization time are the same and the rotational speed of the stirring shaft 122 is different.

[0060] Based on a plurality of test results with different rotational speeds of the stirring shaft 122, the relationship between the rotational speed of the stirring shaft 122 in the pilot plant and the quality of the polymer can be obtained. Thereby, if the target value of the quality of the polymer is determined, the rotational speed of the stirring shaft 122 at which a polymer of the desired quality can be obtained can be determined.

[0061] When the polymerization time is set so that the pilot plant has sufficient heat removal capacity, by setting the polymerization temperature according to the target value of the K value, a polymer having the desired average degree of polymerization can be produced. On the other hand, when the heat removal capacity of the pilot plant is insufficient for the set polymerization time, the polymerization temperature rises due to the heat generated by the polymerization reaction. As described above, there is a correlation between the polymerization temperature and the average degree of polymerization of the produced polymer. Therefore, when the polymerization temperature rises, the error between the K value of the produced polymer and the target value of the K value becomes larger. Also, depending on the rate of increase in the polymerization temperature, the reaction may become uncontrollable.

[0062] Thus, the K value of the produced polymer can be adopted as an index regarding the heat removal capacity of the polymerization apparatus 100. For example, when a polymer is produced using the polymerization apparatus 100, when the target K value is obtained for the set polymerization time, the polymerization apparatus 100 can be determined to have sufficient heat removal capacity.

[0063] As described above, the scale-up from the pilot plant to the polymerization apparatus 100 can be carried out so that the stirring state of the polymerization apparatus 100 and the stirring state of the pilot plant are substantially the same. For example, when the ratio of the size of each internal structure arranged inside the reaction vessel 110 to the inner diameter and / or the height of the straight body part of the reaction vessel 110 in the target polymerization apparatus 100 is substantially the same as the ratio of the size of each internal structure in the pilot plant to the inner diameter and / or the height of the straight body part of the reaction vessel of the pilot plant, when the stirring energy in the polymerization apparatus 100 and the stirring energy in the pilot plant are substantially the same, the stirring state of the scaled-up polymerization apparatus 100 and the stirring state of the pilot plant are substantially the same.

[0064] For example, between the pilot plant and the target polymerization apparatus 100, the size of the baffle 130 in the target polymerization apparatus 100 is determined such that the ratio of the length in the extending direction of the baffle 130 (the vertical direction in the figure) to the height of the straight body portion of the reaction vessel 110 is substantially the same. Between the pilot plant and the target polymerization apparatus 100, the size of the baffle 130 in the target polymerization apparatus 100 is determined such that the ratio of the length in the direction substantially perpendicular to the extending direction of the baffle 130 (the left-right direction in the figure) to the internal diameter (sometimes referred to as the inner diameter) of the reaction vessel 110 is substantially the same. Between the pilot plant and the target polymerization apparatus 100, the number and arrangement of the baffles 130 in the target polymerization apparatus 100 are determined such that the number and arrangement of the baffles 130 are substantially the same. The same applies to other structures (for example, the stirring blade 124, the serpentine cooling pipe 140, the serpentine cooling pipe 150, etc.).

[0065] Also, as described above, if the target value of the quality of the polymer in the scaled-up polymerization apparatus 100 is determined, based on the relationship between the rotational speed of the stirring shaft 122 in the above-described pilot plant and the quality of the polymer, the rotational speed of the stirring shaft 122 in the scaled-up polymerization apparatus 100 can be determined. Specifically, first, based on (i) the target value of the quality of the polymer in the polymerization apparatus 100 and (ii) the relationship between the rotational speed of the stirring shaft 122 in the pilot plant and the quality of the polymer, the rotational speed of the stirring shaft 122 in the pilot plant is determined. Next, the rotational speed of the stirring shaft 122 in the polymerization apparatus 100 is determined such that the stirring energy in the polymerization apparatus 100 and the stirring energy in the pilot plant are substantially the same.

[0066] Thereby, considering (i) the shape, size, number of blades, installation position, installation quantity, and installation interval C of the stirring blade 124 of the target polymerization apparatus 100 i , and (ii) the internal volume of the reaction vessel 110, the shape of the reaction vessel 110, and the internal structures arranged inside the reaction vessel 110, etc., the stirring energy per unit internal volume [kgf·m / s·m 3The rotational speed of the stirring shaft 122 of the target polymerization apparatus 100 can be determined without precisely measuring []. Note that the rotational speed of the stirring shaft 122 in the target polymerization apparatus 100 may be determined based on the simulation results of the polymerization test.

[0067] In other embodiments, the rotational speed of the stirring shaft 122 in the polymerization apparatus 100 is determined such that the dimensions of the straight body portion of the reaction vessel 110, the dimensions of at least one of the plurality of stirring blades 124, and the set value of the rotational speed of the stirring shaft 122 satisfy the relationship shown in the following mathematical formula 1. (Mathematical formula 1) N(b / d)(L / D) / n≦6.0

[0068] In mathematical formula 1, N represents the number of the plurality of stirring blades 124. b represents the maximum value [m] of the blade width of the plurality of stirring blades 124. d represents the maximum value [m] of the blade diameter of the plurality of stirring blades 124. L represents the length [m] of the straight body portion of the reaction vessel 110 in the extending direction. D represents the maximum value [m] of the diameters of a plurality of inscribed circles that are substantially inscribed in the straight body portion in each of the cross-sections formed by a plurality of planes that are planes substantially perpendicular to the extending direction of the straight body portion and pass through the respective mounting positions of the plurality of stirring blades 124 when the straight body portion is cut by the plurality of planes. When the reaction vessel 110 has a cylindrical straight body portion, D is the inner diameter [m] of the straight body portion. n represents the set value of the rotational speed [rps] of the stirring shaft 122.

[0069] The blade diameter of the stirring blade 124 may be the rotational diameter of the stirring blade 124. The rotational diameter of the stirring blade 124 may be the diameter of the rotating body obtained by rotating the stirring blade 124 around the stirring shaft 122. The blade diameter of the stirring blade 124 may be the total length of the stirring blade 124 in a direction (for example, the left-right direction in FIG. 1) that is substantially perpendicular to the extending direction of the stirring shaft 122 when the stirring blade 124 is attached to the stirring shaft 122.

[0070] The wing width of the stirring blade 124 may be the height of the rotating body obtained by rotating the stirring blade 124 around the stirring shaft 122. The wing width of the stirring blade 124 may be the total length of the stirring blade 124 in a direction substantially parallel to the extending direction of the stirring shaft 122 (for example, the vertical direction in FIG. 1) when the stirring blade 124 is attached to the stirring shaft 122.

[0071] According to the present embodiment, the rotational speed of the stirring shaft 122 can be easily determined as compared with the case where the rotational speed of the stirring shaft 122 is determined based on the polymerization test in the pilot plant conducted in advance. Further, even when the rotational speed of the stirring shaft 122 is determined based on the polymerization test in the pilot plant conducted in advance, the rotational speed of the stirring shaft 122 can be easily determined by considering the relationship of the above formula (1).

[0072] It is preferable that the dimensions of the straight body portion of the reaction vessel 110, the dimensions of at least one of the plurality of stirring blades 124, and the set value of the rotational speed of the stirring shaft 122 are determined so as to satisfy the relationship shown in the following formula (2). (Formula 2) 0.05 ≦ N(b / d)(L / D) / n ≦ 6.0

[0073] When the polymerization apparatus 100 includes one or more meandering cooling pipes 140 or one or more meandering cooling pipes 150, it is preferable that the dimensions of the straight body portion of the reaction vessel 110, the dimensions of at least one of the plurality of stirring blades 124, and the set value of the rotational speed of the stirring shaft 122 are determined so as to satisfy the relationship shown in the following formula (3). (Formula 3) 0.15 ≦ N(b / d)(L / D) / n ≦ 5.5

[0074] When the polymerization apparatus 100 includes one or more meandering cooling pipes 140 and one or more meandering cooling pipes 150, it is preferable that the dimensions of the straight body portion of the reaction vessel 110, the dimensions of at least one of the plurality of stirring blades 124, and the set value of the rotational speed of the stirring shaft 122 are determined so as to satisfy the relationship shown in the following formula (4). (Formula 4) 0.3 ≦ N(b / d)(L / D) / n ≦ 5.5

[0075] In one embodiment, based on the dimension of the straight body portion of the reaction vessel 110, the dimension of at least one of the plurality of stirring blades 124, and Equation 1, a set value of the rotation speed of the stirring shaft 122 in the polymerization apparatus 100 is determined. In other embodiments, based on the set value of the rotation speed of the stirring shaft 122 in the polymerization apparatus 100 and Equation 1, the dimension of the straight body portion of the reaction vessel 110 and the dimension of at least one of the plurality of stirring blades 124 are determined. Details of these embodiments will be described in relation to FIG. 17 described later.

[0076] In the present embodiment, the baffle 130 improves the mixing performance of the polymerization apparatus 100. For example, the baffle 130 improves the vertical mixing performance inside the reaction vessel 110. The installation position of the baffle 130 is not particularly limited. For example, the baffle 130 is arranged near the inner wall of the reaction vessel 110. The baffle 130 may be supported by the side wall of the reaction vessel 110. In other embodiments, the baffle 130 is supported by the top plate or the bottom plate of the reaction vessel 110 and is arranged near the stirring blade 124. When the polymerization apparatus 100 is used for the production of a polymer, the upper end of the baffle 130 may be arranged so as to be immersed in the liquid phase, or the upper end of the baffle 130 may be arranged so as not to be immersed in the liquid phase.

[0077] The number of the baffles 130 is preferably about 1 to 12, preferably about 2 to 8, more preferably about 3 to 6, and even more preferably about 4 to 6. It is preferable that an even number of baffles 130 are arranged substantially symmetrically around the extension axis (which may be referred to as the central axis) of the reaction vessel 110. Thereby, the mixing performance of the polymerization apparatus 100 is further improved, and the retention of the liquid is suppressed. As a result, the generation of scale can be suppressed.

[0078] In this embodiment, the main body 132 of the baffle 130 improves the mixing performance of the polymerization apparatus 100. The shape of the main body 132 is not particularly limited, but the main body 132 has, for example, a plate-like or cylindrical shape that extends substantially parallel to the extending direction of the reaction vessel 110. When the main body 132 has a cylindrical shape, the diameter of the main body 132 may be 40 to 500 mm. The length Bh (which may be referred to as the height Bh) in the extending direction of the main body 132 (the z direction in the figure) is not particularly limited.

[0079] The length Bw (which may be referred to as the width Bw) in the direction substantially perpendicular to the extending direction of the main body 132 (the x or y direction in the figure) is not particularly limited. The ratio of the width Bw of the main body 132 to the inner diameter of the reaction vessel 110 may be 1 to 10%, may be 2.5 to 7.5%, or may be 3 to 7%.

[0080] When the main body 132 has a cylindrical shape, the ratio of the total value of the cross-sectional areas of one or more main bodies 132 each having a cylindrical shape to the cross-sectional area of the straight body portion of the reaction vessel 110 may be 0.4 to 3%. When the above ratio is less than 0.4%, the function as a baffle plate is insufficient, and the vertical mixing inside the reaction vessel 110 may become insufficient. For example, when the polymerization apparatus 100 includes a single baffle 130, the above ratio may be less than 0.4%. For example, in the suspension polymerization of a vinyl chloride-based monomer, when the vertical mixing inside the reaction vessel 110 becomes insufficient, the particle size distribution of the produced polymer may become broad. As a result, when the produced polymer is formed into a sheet shape, for example, fish eyes may increase and the quality of the molded product may deteriorate.

[0081] On the other hand, when the above ratio exceeds 3%, the required power of the stirrer 120 excessively increases. Also, the fluidity of the liquid between the baffle 130 and the inner wall surface of the reaction vessel 110 may decrease. As a result, scale may easily adhere to the reaction vessel 110 or the structures inside the reaction vessel 110. For example, when the polymerization apparatus 100 includes more than eight baffles 130, the above ratio may exceed 3% depending on the design of the polymerization apparatus 100.

[0082] The main body 132 of at least one baffle 130 may have a flow path for allowing a heat medium to flow through. The above flow path may be formed inside the main body 132 or arranged outside the main body 132. The above flow path may be a single pipe or may have a double-pipe structure.

[0083] The heat medium may be a known refrigerant. Examples of the refrigerant include water, brine, freon, and other liquefied gases. When a liquefied gas is used as the refrigerant, the liquefied gas may function as a refrigerant by evaporating inside the serpentine cooling pipe 140. The linear velocity of the refrigerant may be about 0.1 to 6.0 m / s.

[0084] The main body 132 is connected to the inner wall surface of the reaction vessel 110 via, for example, a support 134. The distance between the main body 132 and the inner wall surface of the polymerization apparatus 100 is preferably 40 mm or more. When the above distance is less than 40 mm, a polymer scale may easily adhere between the inner wall surface of the reaction vessel 110 and the baffle 130 in the vicinity of the gas-liquid interface inside the reaction vessel 110. Details of the main body 132 will be described later.

[0085] In the present embodiment, the support 134 holds the main body 132. For example, one end of the support 134 contacts the inner wall surface of the reaction vessel 110, and the other end of the support 134 contacts the main body 132. As described above, the support 134 may hold the main body 132 such that the distance between the main body 132 and the inner wall surface of the polymerization apparatus 100 is 40 mm or more.

[0086] (Serpentine cooling pipe 140) In this embodiment, a serpentine cooling pipe 140 has a flow path formed therein for allowing a heat medium to flow therethrough. The serpentine cooling pipe 140 may be a single pipe. The serpentine cooling pipe 140 is arranged at a position closer to the central axis of the reaction vessel 110 than the serpentine cooling pipe 150. The number of the serpentine cooling pipes 140 is preferably about 1 to 12, more preferably about 2 to 8, still more preferably about 3 to 6, and even more preferably about 4 to 6. It is preferable that an even number of the serpentine cooling pipes 140 are arranged substantially symmetrically around the central axis of the reaction vessel 110.

[0087] The heat medium may be a known refrigerant. Examples of the refrigerant include water, brine, freon, and other liquefied gases. When a liquefied gas is used as the refrigerant, the liquefied gas may function as the refrigerant by evaporating inside the serpentine cooling pipe 140. The linear velocity of the refrigerant may be about 0.1 to 6.0 m / s.

[0088] In this embodiment, at least a part of the serpentine cooling pipe 140 extends while repeatedly bending. Among the serpentine cooling pipes 140, the length Ph in the extending direction of the portion that extends while repeatedly bending may be smaller than the length Bh in the extending direction (the z direction in the figure) of the main body 132 of the baffle 130, may be substantially the same as the Bh, or may be larger than the Bh. Thereby, the heat transfer area per installation area becomes large.

[0089] In the example shown in FIG. 1, the serpentine cooling pipe 140 extends substantially parallel to the extending direction of the reaction vessel 110 while repeatedly bending. In the example shown in FIG. 1, the entire serpentine cooling pipe 140 extends while repeatedly bending. The ratio of the length Ph in the extending direction of the portion that extends while repeatedly bending among the serpentine cooling pipes 140 to the total length Pt (not shown) in the extending direction of the serpentine cooling pipe 140 may be 0.25 or more, may be 0.5 or more, may be 0.75 or more, may be 0.8 or more, or may be 0.9 or more.

[0090] When the polymerization apparatus 100 is used for producing a polymer, the serpentine cooling pipe 140 may be arranged such that the upper end of the serpentine cooling pipe 140 is immersed in the liquid phase. This is because if the upper part of the serpentine cooling pipe 140 is exposed to the gas phase, the heat transfer efficiency will decrease, and scale of the polymer will easily adhere to the serpentine cooling pipe 140. At the end stage of polymerization, the gas-liquid interface drops due to liquid shrinkage. Therefore, it is preferable that the serpentine cooling pipe 140 is arranged at a position where there is a sufficient distance between the upper end of the serpentine cooling pipe 140 and the gas-liquid interface even at the end of polymerization. Details of the serpentine cooling pipe 140 will be described later.

[0091] (Serpentine cooling pipe 150) In the present embodiment, a flow path for allowing a heat medium to flow is formed inside the serpentine cooling pipe 150. The serpentine cooling pipe 150 may be a single pipe. The serpentine cooling pipe 150 is arranged at a position closer to the side wall of the reaction vessel 110 than the serpentine cooling pipe 140. The number of the serpentine cooling pipes 150 is preferably about 1 to 12, more preferably about 2 to 8, still more preferably about 3 to 6, and even more preferably about 4 to 6. The number of the serpentine cooling pipes 150 may be the same as or different from the number of the serpentine cooling pipes 140. It is preferable that an even number of the serpentine cooling pipes 150 are arranged substantially symmetrically around the central axis of the reaction vessel 110.

[0092] The heat medium may be a known refrigerant. Examples of the refrigerant include water, brine, freon, and other liquefied gases. When a liquefied gas is used as the refrigerant, the liquefied gas may function as a refrigerant by evaporating inside the serpentine cooling pipe 140. The linear velocity of the refrigerant may be about 0.1 to 6.0 m / s.

[0093] In the present embodiment, at least a part of the serpentine cooling pipe 150 extends while repeatedly bending. Among the serpentine cooling pipes 150, the length Ph in the extending direction of the portion that extends while repeatedly bending may be smaller than, substantially the same as, or larger than the length Bh in the extending direction (the z direction in the figure) of the main body 132 of the baffle 130. Thereby, the heat transfer area per installation area becomes large.

[0094] In the example shown in FIG. 1, the meandering cooling pipe 150 extends substantially parallel to the extending direction of the reaction vessel 110 while repeatedly bending. In the example shown in FIG. 1, the entire meandering cooling pipe 150 extends while repeatedly bending. The ratio of the length Ph in the extending direction of the portion of the meandering cooling pipe 150 that extends while repeatedly bending to the total length Pt in the extending direction of the meandering cooling pipe 150 (not shown) may be 0.25 or more, may be 0.5 or more, may be 0.75 or more, may be 0.8 or more, or may be 0.9 or more.

[0095] When the polymerization apparatus 100 is used for producing a polymer, the meandering cooling pipe 150 may be arranged such that the upper end of the meandering cooling pipe 150 is immersed in the liquid phase. This is because if the upper part of the meandering cooling pipe 150 is exposed to the gas phase, the heat transfer efficiency will decrease and the scale of the polymer will easily adhere to the meandering cooling pipe 150. At the end stage of polymerization, the gas-liquid interface drops due to liquid shrinkage. Therefore, it is preferable that the meandering cooling pipe 150 is arranged at a position where there is a sufficient distance between the upper end of the meandering cooling pipe 150 and the gas-liquid interface even at the end of polymerization.

[0096] In one embodiment, the flow direction of the refrigerant in the meandering cooling pipe 150 is set such that the refrigerant flows from below the reaction vessel 110 toward above the reaction vessel 110. In other embodiments, the flow direction of the refrigerant in the meandering cooling pipe 150 is set such that the refrigerant flows from above the reaction vessel 110 toward below the reaction vessel 110.

[0097] For example, the liquid returned from the reflux condenser 180 is at a lower temperature and has a higher density than the liquid inside the reaction vessel 110. Therefore, in the vicinity of the inlet of the liquid returned from the reflux condenser 180, there is a tendency for the liquid inside the reaction vessel 110 to flow from above downward. Thus, for example, the meandering cooling pipe 150 arranged in the vicinity of the inlet of the liquid returned from the reflux condenser 180 may be configured such that the refrigerant flows from below the reaction vessel 110 toward above the reaction vessel 110. Details of the meandering cooling pipe 150 will be described later.

[0098] (Planar Arrangement of Serpentine Cooling Pipe 140 and Serpentine Cooling Pipe 150) As described above, in the present embodiment, the serpentine cooling pipe 140 and the serpentine cooling pipe 150 are arranged in multiple stages in the diameter direction of the straight body portion 312 of the reaction vessel 110. According to the present embodiment, in a plane (xy plane in the figure) substantially perpendicular to the extending direction of the straight body portion of the reaction vessel 110 (the z direction in the figure as described above), representative points of each of the one or more serpentine cooling pipes 140 and the one or more serpentine cooling pipes 150 are located on the circumference of any one of a plurality of virtual circles arranged substantially concentrically in the xy plane. Details of the plurality of virtual circles will be described later.

[0099] The representative point of each of the one or more serpentine cooling pipes 140 may be any point on the center line of each pipe. When the serpentine cooling pipe 140 includes (i) a plurality of extending portions extending linearly or curvingly, and (ii) a plurality of bending portions connecting the ends of two adjacent extending portions among the plurality of extending portions, the representative point of the serpentine cooling pipe 140 may be any point on the center line of the extending portion. When the above xy plane does not pass through the center of the extending portion, the representative point of the serpentine cooling pipe 140 may also be any point on the center line of the extending portion projected onto the xy plane.

[0100] The representative point of each of the one or more serpentine cooling pipes 150 may be any point on the center line of each pipe. When the serpentine cooling pipe 150 includes (i) a plurality of extending portions extending linearly or curvingly, and (ii) a plurality of bending portions connecting the ends of two adjacent extending portions among the plurality of extending portions, the representative point of the serpentine cooling pipe 150 may be any point on the center line of the extending portion. When the above xy plane does not pass through the center of the extending portion, the representative point of the serpentine cooling pipe 150 may also be any point on the center line of the extending portion projected onto the xy plane.

[0101] In the present embodiment, the jacket 170 heats or cools the reaction vessel 110 from the outside of the reaction vessel 110. As described above, the jacket 170 has a flow path 172 configured to allow a heat medium to flow therethrough. The jacket 170 adjusts the heating amount and the heat removal amount of the reaction vessel 110 by controlling at least one of the temperature and the flow rate of the heat medium flowing through the flow path 172.

[0102] The heat medium may be a known refrigerant. Examples of the refrigerant include water, brine, freon, and various liquefied gases. It is preferable that a liquid refrigerant is used as the refrigerant. When a liquefied gas is used as the refrigerant, the liquefied gas may function as a refrigerant by evaporating inside the serpentine cooling pipe 140. The linear velocity of the refrigerant may be about 0.1 to 6.0 m / s.

[0103] In the present embodiment, the reflux condenser 180 is used for heat removal from the reaction vessel 110. For example, steam from the reaction vessel 110 is supplied to the reflux condenser 180. The reflux condenser 180 cools and liquefies the above steam. The reflux condenser 180 returns the liquid generated by the above cooling to the reaction vessel 110. As described above, the reflux condenser 180 has a flow path 182 configured to allow a heat medium to flow therethrough. The reflux condenser 180 cools the steam from the reaction vessel 110 by heat exchange between the heat medium flowing through the flow path 182 and the steam from the reaction vessel 110. The heat removal amount of the reaction vessel 110 can be adjusted by controlling at least one of the temperature and the flow rate of the heat medium flowing through the flow path 182.

[0104] (Relationship of heat removal means) As described above, in the present embodiment, the reaction vessel 110 has, as heat removal means, a baffle 130, a serpentine cooling pipe 140, a serpentine cooling pipe 150, a jacket 170, and a reflux condenser 180. The ratio of the amount of heat removed using each heat removal device to the total heat generation amount is not particularly limited. The above ratio is determined, for example, in consideration of the quality of the polymer produced, the manufacturing cost, and the like. For example, the ratio of the amount of heat removed by the baffle 130 to the total heat generation amount is preferably 10 to 30%. The ratio of the total amount of heat removed by the serpentine cooling pipe 140 and the serpentine cooling pipe 150 to the total heat generation amount is preferably 10 to 50%. The ratio of the amount of heat removed by the jacket 170 to the total heat generation amount is preferably 20 to 40%. The ratio of the amount of heat removed by the reflux condenser 180 to the total heat generation amount is preferably 10 to 50%.

[0105] Further, the serpentine cooling pipe 140 and the serpentine cooling pipe 150 are designed such that the ratio of the total surface area of the serpentine cooling pipe 140 and the serpentine cooling pipe 150 to the internal volume of the reaction vessel 110 is 0.1 to 0.9 [m 2 / m 3 . Preferably, the above ratio is 0.5 to 0.7 [m 2 / m 3 . Thereby, the ratio of the total amount of heat removed by the serpentine cooling pipe 140 and the serpentine cooling pipe 150 to the total heat generation amount can be made 10 to 50%.

[0106] (Materials of each part of the polymerization apparatus 100) The materials of each part of the polymerization apparatus 100 are appropriately determined in consideration of mechanical strength, corrosion resistance, heat transfer performance, and the like. For example, as the materials used for the stirring shaft 122, the stirring blade 124, the baffle 130, the serpentine cooling pipe 140, and the serpentine cooling pipe 150, stainless steels such as high-chromium high-purity ferritic stainless steel, duplex stainless steel, and austenitic stainless steel are preferable. These materials are excellent in heat transfer performance and corrosion resistance. Further, as the material of the inner wall surface of the reaction vessel 110, clad steel containing stainless steel is exemplified. The material of the outer layer of the above clad steel is preferably carbon steel, and the material of the inner layer of the clad steel is preferably stainless steel.

[0107] (Use of the polymerization apparatus 100) As described above, the polymerization apparatus 100 is used for the production of polymers. The polymerization method may be suspension polymerization or emulsion polymerization. More specifically, the polymerization apparatus 100 is used for the production of polymers by polymerizing various vinyl monomers, such as olefins such as ethylene and propylene, vinyl halides such as vinyl chloride and vinylidene chloride, vinyl esters such as vinyl acetate, vinyl ethers such as ethyl vinyl ether, (meth)acrylic acid esters such as methyl methacrylate, metal salts or esters of maleic acid or fumaric acid, aromatic vinyls such as styrene, diene monomers such as butadiene, chloroprene, and isoprene, and acrylonitrile. The polymerization apparatus 100 is particularly preferably used for the production of polymers by polymerizing vinyl chloride or a monomer mixture mainly composed of vinyl chloride.

[0108] When a polymer is produced using the polymerization apparatus 100, each raw material is supplied from the supply port (not shown) of the polymerization apparatus, and when the temperature of the reaction compound charged into the reaction vessel 110 reaches a predetermined temperature, a refrigerant is circulated through each of the baffle 130, the serpentine cooling pipe 140, the serpentine cooling pipe 150, and the jacket 170, and heat removal of the reaction compound is started. On the other hand, the timing of starting heat removal by the reflux condenser 180 is preferably after the polymerization conversion rate reaches 4%, and more preferably when the polymerization conversion rate is 4 to 20%.

[0109] Even when a polymer is produced using the polymerization apparatus 100, various polymerization conditions may be the same as known polymerization conditions. Examples of the above polymerization conditions include the charging ratio of raw materials and the like, the charging method of raw materials and the like, and the polymerization temperature and the like.

[0110] For example, when a vinyl chloride-based polymer is produced by suspension polymerization using a polymerization apparatus 100, the charging of an aqueous medium, vinyl chloride monomer, and optionally other comonomers, a dispersion aid (sometimes simply referred to as a dispersant), a polymerization initiator, etc. is carried out in the same manner as in known production methods of vinyl chloride-based polymers. Also, the polymerization conditions may be the same as those in known production methods of vinyl chloride-based polymers. The vinyl chloride monomer and / or the above other comonomers may be an example of one or more types of monomers that serve as raw materials for the polymer.

[0111] (Monomer) As the monomer to be polymerized, in addition to vinyl chloride alone, a monomer mixture mainly composed of vinyl chloride (vinyl chloride 50% by mass or more) can be used. Examples of comonomers copolymerized with vinyl chloride include vinyl esters such as vinyl acetate and vinyl propionate; acrylic acid esters or methacrylic acid esters such as methyl acrylate and ethyl acrylate; olefins such as ethylene and propylene; maleic anhydride; acrylonitrile; styrene; vinylidene chloride; and other monomers copolymerizable with vinyl chloride. The vinyl chloride, the monomer mixture mainly composed of vinyl chloride, and the comonomers copolymerized with vinyl chloride may be an example of one or more types of monomers that serve as raw materials for the polymer.

[0112] (Dispersion aid) As the above dispersion aid, a compound usually used during the polymerization of vinyl chloride in an aqueous medium is used. Examples of the above dispersion aid include water-soluble cellulose ethers such as methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, and hydroxypropyl methyl cellulose (HPMC); water-soluble polymers such as partially saponified polyvinyl alcohol (PVA), acrylic acid polymers, and gelatin. The above dispersion aid may be used alone or in combination of two or more.

[0113] For example, the degree of saponification of the partially saponified polyvinyl alcohol may be 20 to 90 mol%. The degree of saponification of the partially saponified polyvinyl alcohol may be 40 to 90 mol%, or may be 50 to 90 mol%. Examples of the degree of saponification of the partially saponified polyvinyl alcohol include 25 mol%, 40 mol%, 48 mol%, 55 mol%, 72 mol%, 78 mol%, 80 mol%, 88 mol%, etc. A plurality of types of partially saponified polyvinyl alcohol with different degrees of saponification may be used as the dispersion aid. The partially saponified polyvinyl alcohol may be modified.

[0114] The dispersion aid can be classified into a main dispersant for adjusting the particle size of the polymer and a secondary dispersant for adjusting the porosity of the polymer. Examples of the main dispersant include partially saponified PVA, HPMC, etc. Examples of the secondary dispersant include partially saponified PVA, HPMC, etc.

[0115] In one embodiment, the dispersion aid is added, for example, in an amount of 0.01 to 5 parts by mass per 100 parts by mass of the monomer to be charged. In other embodiments, the addition amount of the dispersion aid (which may be referred to as the input amount) is adjusted according to the state of the internal structure arranged inside the reaction vessel 110.

[0116] For example, the addition amount of the dispersion aid is adjusted according to the degree of radial multiplexing of the cooling pipes arranged inside the reaction vessel 110. As described above, in the embodiment described in relation to FIG. 1, each representative point of the one or more serpentine cooling pipes 140 and the one or more serpentine cooling pipes 150 is substantially located on the circumference of any of a plurality of virtual circles (which may be referred to as virtual circles) arranged in a substantially concentric manner in the xy plane. The above representative points may be arranged at positions slightly away from the above circumferences to such an extent that the functions of each cooling pipe are not impaired, for example, due to manufacturing or design errors. The number N [pieces] of the plurality of virtual circles can be used as an index indicating the degree of radial multiplexing of the cooling pipes or the state of the internal structure.

[0117] For example, when the number N [pieces] of the plurality of virtual circles described above is 1, 2, or 3, the number Nc [pieces] of the virtual circles and the ratio CZ [mg - dispersion aid / kg - monomer] of the mass of the dispersion aid to the mass of the monomer charged into the reaction vessel 110 satisfy the relationship shown in the following mathematical formula A1. For example, the addition amount of the dispersion aid is adjusted so as to satisfy the relationship shown in the following mathematical formula A1. (Mathematical formula A1) 15Nc + 300 < CZ < 175Nc + 2000

[0118] When a plurality of types of monomers are charged into the reaction vessel 110 as raw materials for the polymer, the mass of the monomers charged into the reaction vessel 110 may be the sum of the masses of the respective monomers of the plurality of types. As described above, by adjusting the addition amount of the dispersion aid according to the state of the internal structure, the stability of the liquid (sometimes referred to as a polymerization system) in the reaction vessel is improved.

[0119] When comparing the stability of the polymerization system when there are many structures (excluding the stirring shaft and stirring blades) arranged inside the reaction vessel 110 with the stability of the polymerization system when there are few structures arranged inside the reaction vessel 110, when there are many structures arranged inside the reaction vessel 110, the polymerization system tends to become unstable. For example, usually, inside the reaction vessel 110, baffles are arranged in the vicinity of the inner wall of the reaction vessel 110 to such an extent that the polymerization system is relatively stable. On the other hand, as in the embodiment described in relation to FIG. 1, when a cooling pipe is arranged inside the reaction vessel 110, the flow state around the cooling pipe and / or the flow state in the region between the cooling pipe and the inner wall of the reaction vessel 110 tends to become unstable. As a result, the polymerization system tends to become unstable.

[0120] Even in such a case, when a dispersion aid is added to the polymerization system, the polymerization system becomes stable. For example, when a dispersion aid is added to the polymerization system, the dispersion characteristics of the suspension are improved. As a result, the form of the polymer particles (sometimes referred to as resin particles) can be improved, and the absorption performance of the plasticizer can be enhanced. Note that a buffer may be added to the polymerization system. By adding a buffer to the polymerization system, the stability of the polymerization system is further improved.

[0121] Generally, the addition amount of the dispersion aid is determined by repeating trials and errors. The inventors focused on the fact that among the structures arranged inside the reaction vessel 110, the structure that greatly affects the flow state of the polymerization system is the cooling pipe, and found that there is a correlation between the amount of the cooling pipe in the radial direction of the reaction vessel 110 and the addition amount of the dispersion aid.

[0122] That is, according to the present embodiment, the number Nc [pieces] of the above virtual circles and the above ratio CZ [mg-dispersion aid / kg-monomer] are adjusted so as to satisfy the relationship of Formula A1. Thereby, resin particles having a small particle size distribution and few fish eyes are produced. In addition, the amount of scale adhering to the inside of the reaction vessel 110 during the polymerization reaction is suppressed.

[0123] By producing the polymer so as to satisfy the relationship of Formula A1, the yield can be improved while maintaining the quality of the polymer particles described above. For example, a yield of about 90% can be obtained. In addition, unreacted monomers may be recovered after the completion of the polymerization reaction, and the recovered monomers (sometimes referred to as recovered monomers) may be used as raw materials in subsequent reactions. By producing the polymer so as to satisfy the relationship of Formula A1, the usage ratio of the recovered monomers can be improved. For example, the usage ratio of the recovered monomers can be set to about 30%.

[0124] In addition, the inventors found that when the addition amount of the dispersion aid exceeds a certain level, even if the addition amount of the dispersion aid is increased, the effect of stabilizing the polymerization system by the dispersion aid does not increase significantly. Specifically, when the number Nc of the above virtual circles is 3, it was found that an amount of the dispersion aid sufficient to stabilize the polymerization system was added.

[0125] For example, when the number Nc of the above virtual circles is 4 or more, the above ratio CZ [mg - dispersion aid / kg - monomer] preferably satisfies the relationship shown in the following mathematical formula A2. For example, the addition amount of the dispersion aid is adjusted so as to satisfy the relationship shown in the following mathematical formula A2. Thereby, while suppressing the excessive addition of the dispersion aid, the above-described effects can be obtained. (Mathematical formula A2) 15×3 + 300 < CZ < 175×3 + 2000

[0126] When the number Nc [pieces] of the above virtual circles and the above ratio CZ [mg - dispersion aid / kg - monomer] are adjusted to satisfy the relationship shown in Mathematical formula A1, the average degree of polymerization of the produced polymer is adjusted to be, for example, about 200 to 4000. The above average degree of polymerization may be adjusted to be 300 to 4000, or may be adjusted to be 300 to 2000. The above average degree of polymerization may be adjusted to be 500 to 1500.

[0127] As described above, a relatively strong correlation is observed between the average degree of polymerization of the polymer and the reduced viscosity or K - value of the polymer. Also, the polymerization temperature is set according to the target reduced viscosity or K - value of the polymer. Therefore, in other embodiments, instead of adjusting the average degree of polymerization of the produced polymer, the reduced viscosity or K - value of the polymer, or the polymerization temperature may be adjusted.

[0128] For example, when a vinyl chloride resin is produced, when the number Nc [pieces] of the above virtual circles and the above ratio CZ [mg - dispersion aid / kg - monomer] are adjusted to satisfy the relationship shown in Mathematical formula A1, the reaction temperature (sometimes referred to as the polymerization temperature) is adjusted to 30 to 75 degrees. The above reaction temperature may be adjusted to 40 to 70 degrees, or may be adjusted to 50 to 60 degrees.

[0129] In one embodiment, when the number Nc [pieces] of the virtual circles is 1, 2, or 3, the number Nc [pieces] of the virtual circles and the above ratio CZ [mg - dispersion aid / kg - monomer] may satisfy the relationship shown in the following mathematical formula B1. For example, the addition amount of the dispersion aid is adjusted so as to satisfy the relationship shown in the following mathematical formula B1. Thereby, the amount of scale adhering to the inside of the reaction vessel 110 due to the polymerization reaction can be further suppressed. (Mathematical formula B1) 15Nc + 310 < CZ < 175Nc + 1550

[0130] When the number Nc of the above virtual circles is 4 or more, the above ratio CZ [mg - dispersion aid / kg - monomer] may satisfy the relationship shown in the following mathematical formula B2. For example, the addition amount of the dispersion aid is adjusted so as to satisfy the relationship shown in the following mathematical formula B2. Thereby, the above-described effect can be obtained. (Mathematical formula B2) 15×3 + 310 < CZ < 175×3 + 1550

[0131] In another embodiment, when the number Nc [pieces] of the above virtual circles is 1, 2, or 3, the number Nc [pieces] of the virtual circles and the above ratio CZ [mg - dispersion aid / kg - monomer] may satisfy the relationship shown in the following mathematical formula C1. For example, the addition amount of the dispersion aid is adjusted so as to satisfy the relationship shown in the following mathematical formula C1. Thereby, resin particles with extremely few fish eyes can be produced. (Mathematical formula C1) 15Nc + 400 < CZ < 175Nc + 1850

[0132] When the number Nc of the above virtual circles is 4 or more, the above ratio CZ [mg - dispersion aid / kg - monomer] may satisfy the relationship shown in the following mathematical formula C2. For example, the addition amount of the dispersion aid is adjusted so as to satisfy the relationship shown in the following mathematical formula C2. Thereby, the above-described effect can be obtained. (Mathematical formula C2) 15×3 + 400 < CZ < 175×3 + 1850

[0133] In still other embodiments, when the number Nc [pieces] of the virtual circles is 1, 2, or 3, the number Nc [pieces] of the virtual circles and the above ratio CZ [mg - dispersion aid / kg - monomer] may satisfy the relationship shown in the following mathematical formula D1. For example, the addition amount of the dispersion aid is adjusted so as to satisfy the relationship shown in the following mathematical formula D1. Thereby, the amount of scale adhering to the inside of the reaction vessel 110 during the polymerization reaction is further suppressed, and resin particles with extremely few fish eyes can be produced. (Mathematical formula D1) 15Nc + 400 < CZ < 175Nc + 1550

[0134] When the number Nc of the above virtual circles is 4 or more, the above ratio CZ [mg - dispersion aid / kg - raw material solution] may satisfy the relationship shown in the following mathematical formula D2. For example, the addition amount of the dispersion aid is adjusted so as to satisfy the relationship shown in the following mathematical formula D2. Thereby, the above-described effects can be obtained. (Mathematical formula D2) 15×3 + 400 < CZ < 175×3 + 1550

[0135] By appropriately adjusting the stirring of the polymerization system in addition to the addition amount of the dispersion aid, the polymerization system becomes more stable. For example, (a) the rotation speed of the stirring shaft 122 in the polymerization apparatus 100 is determined so that the dimensions of the straight body portion of the reaction vessel 110, the dimensions of at least one of the plurality of stirring blades 124, and the set value of the rotation speed of the stirring shaft 122 satisfy the relationship shown in the above mathematical formula 1, and (b) when the number Nc [pieces] of the virtual circles and the ratio CZ [mg - dispersion aid / kg - monomer] of the mass of the dispersion aid to the mass of the monomer charged into the reaction vessel 110 satisfy the relationship shown in the above mathematical formula A1, B1, C1, or D1, particularly good results can be obtained. Also, the above correlation becomes clearer. When the number Nc of the above virtual circles is 4 or more, the number Nc and the ratio CZ may satisfy the relationship shown in the above mathematical formula A2, B2, C2, or D2.

[0136] Although the causes of these phenomena are not certain, it is presumed that, for example, the polymerization system becomes extremely stable due to the synergistic effect of the effect of appropriately controlling the stirring energy and the effect of appropriately controlling the addition amount of the dispersion aid. As a result, the amount of scale adhering to the inside of the reaction vessel 110 during the polymerization reaction can be suppressed. In addition, resin particles with extremely few fish eyes can be produced.

[0137] (Polymerization initiator) As the above polymerization initiator, compounds conventionally used in vinyl chloride polymerization are used. Examples of the above polymerization initiators include percarbonate compounds such as diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, and diethoxyethyl peroxydicarbonate; perester compounds such as α-cumyl peroxyneodecanoate, t-butyl peroxyneodecanoate, t-butyl peroxyneoheptanoate, hexyl peroxyneodecanoate, and octyl peroxyneodecanoate; peroxides such as acetylcyclohexylsulfonyl peroxide and 2,4,4-trimethylpentyl-2-peroxyphenoxyacetate; and azo compounds such as azobis-2,4-dimethylvaleronitrile and azobis(4-methoxy-2,4-dimethylvaleronitrile). The above polymerization initiators may be used alone or in combination of two or more.

[0138] The addition amount of the polymerization initiator is not particularly limited. The polymerization initiator is added, for example, in an amount of 0.01 to 3 parts by mass per 100 parts by mass of the monomer. The addition amount of the polymerization initiator is preferably 0.05 to 3 parts by mass per 100 parts by mass of the monomer.

[0139] Furthermore, various auxiliary agents such as polymerization regulators, chain transfer agents, pH adjusters, buffers, gelation improvers, antistatic agents, and scale inhibitors appropriately used in the polymerization of vinyl chloride can be added as necessary. Regarding the reduced viscosity (K value) of the vinyl chloride polymer obtained in the present invention, although a polymer in a desired range can be obtained by using the apparatus of the present invention, preferably a polymer in the range of 40 to 90 can be obtained.

[0140] Examples of the pH adjuster or buffer include citric acid, trisodium citrate, diammonium citrate, triammonium citrate, potassium hydrogen phthalate, sodium nitrate, sodium carbonate, potassium carbonate, cesium carbonate, sodium hydrogen carbonate, sodium hydroxide, potassium hydroxide, barium hydroxide, disodium phosphate, dipotassium phosphate, tripotassium phosphate, and the like. The above pH adjuster or buffer may be used alone or in combination of two or more.

[0141] The polymerization apparatus 100 may be an example of a reaction apparatus. The polymerization apparatus 100 may be an example of a batch-type reaction apparatus. The reaction vessel 110 may be an example of a reactor. The inner surface of the reaction vessel 110 may be an example of the inner wall surface of the reactor. The side surface of the reaction vessel 110 may be an example of the inner wall surface of the reactor. The flow path of the heat medium disposed in the main body 132 of the baffle 130 may be an example of the second cooling pipe. The support 134 of the baffle 130 may be an example of at least a part of the baffle. The serpentine cooling pipe 140 may be an example of the first cooling pipe. The serpentine cooling pipe 150 may be an example of the first cooling pipe. One of the serpentine cooling pipes 140 and one of the serpentine cooling pipes 150 may be an example of at least two of the plurality of first cooling pipes. The flow path 172 may be an example of the third cooling pipe. The flow path 182 may be an example of the third cooling pipe.

[0142] (An example of another embodiment) In this embodiment, an example of the polymerization apparatus 100 has been described by taking as an example the case where the serpentine cooling pipes 140 and 150 that extend while repeatedly bending are disposed inside the reaction vessel 110. As described above, the serpentine cooling pipes 140 and 150 include a plurality of extending portions that extend linearly or curvedly, and one or more bending portions that connect the ends of two adjacent extending portions. However, the polymerization apparatus 100 is not limited to this embodiment.

[0143] In other embodiments, the polymerization apparatus 100 may include a ring-shaped (sometimes referred to as a coil shape) cooling pipe (sometimes referred to as a ring cooling pipe) inside the reaction vessel 110 as described in Japanese Patent Laid-Open No. 7-233206. The polymerization apparatus 100 may include a plurality of ring cooling pipes. The representative points of the plurality of ring cooling pipes may be substantially located on the circumferences of the plurality of virtual circles described above. Each of the plurality of ring cooling pipes includes, for example, a plurality of ring portions having a ring shape and one or more connecting portions connecting the plurality of ring portions, as shown in Japanese Patent Laid-Open No. 7-233206.

[0144] Even when the polymerization apparatus 100 includes one or more ring cooling pipes inside the reaction vessel 110, when the number Nc [pieces] of the virtual circles is 1, 2, or 3, the number Nc [pieces] of the virtual circles and the ratio CZ [mg - dispersion aid / kg - monomer] of the mass of the dispersion aid to the mass of the monomer charged into the reaction vessel 110 may satisfy the relationships shown in the above mathematical formulas A1, B1, C1, or D1. Thereby, the above-described effects can be obtained.

[0145] FIG. 2 schematically shows an example of the internal structure arranged inside the reaction vessel 110. In FIG. 2, for the purpose of simplicity of explanation, the depiction of the stirrer 120 is omitted. As shown in FIG. 2, the polymerization apparatus 100 includes baffle 232, baffle 234, baffle 236, and baffle 238 as one or more baffles 130. Further, the polymerization apparatus 100 includes serpentine cooling pipe 242, serpentine cooling pipe 244, serpentine cooling pipe 246, and serpentine cooling pipe 248 as one or more serpentine cooling pipes 140. Similarly, the polymerization apparatus 100 includes serpentine cooling pipe 252, serpentine cooling pipe 254, serpentine cooling pipe 256, and serpentine cooling pipe 258 as one or more serpentine cooling pipes 150.

[0146] FIG. 3 shows a schematic cross-sectional view of an example of the reaction vessel 110. In FIG. 3, for the purpose of simplicity of explanation, the depiction of the serpentine cooling pipe 140 is omitted. Also, for the purpose of simplicity of explanation, the installation positions of the baffles 232, 234, 236, and 238 are deformed.

[0147] As shown in FIG. 3, in the present embodiment, the reaction vessel 110 includes a straight cylindrical portion 312, a first end plate 314, a second end plate 316, and a pedestal 318. In the present embodiment, the straight cylindrical portion 312 has a cylindrical shape. When the length of the straight cylindrical portion 312 in the extending direction (the z direction in the figure) is L and the inner diameter of the straight cylindrical portion 312 is D, the straight cylindrical portion 312 is designed such that the value of L / D is, for example, 1.0 to 3.0. The straight cylindrical portion 312 may be designed such that the value of L / D is 1.5 to 2.5.

[0148] In the present embodiment, the first end plate 314 is coupled to one end of the straight cylindrical portion 312 and constitutes the bottom plate of the reaction vessel 110. In the present embodiment, the second end plate 316 is coupled to the other end of the straight cylindrical portion 312 and constitutes the top plate of the reaction vessel 110. In the present embodiment, the pedestal 318 holds the power mechanism 126.

[0149] Also, as shown in FIG. 3, around the polymerization apparatus 100, there are arranged a refrigerant supply pipe 332 for supplying refrigerant from a refrigerant supply source to the reaction vessel 110 and a refrigerant return pipe 334 for returning the heat-exchanged refrigerant from the reaction vessel 110 to the refrigerant supply source. Further, according to the embodiment shown in FIG. 3, the baffle 232 and the baffle 234 are connected by a connecting portion 342, and the refrigerant flowing out from the baffle 232 is configured to be able to flow into the baffle 234. Also, the baffle 234 and the baffle 236 are connected by a connecting portion 344, and the refrigerant flowing out from the baffle 234 is configured to be able to flow into the baffle 236. Similarly, the baffle 236 and the baffle 238 are connected by a connecting portion 346, and the refrigerant flowing out from the baffle 236 is configured to be able to flow into the baffle 238. Details of each baffle will be described later.

[0150] According to the present embodiment, the refrigerant supplied from the refrigerant supply pipe 332 to the reaction vessel 110 flows into the baffle 232, passes through the baffle 234, the baffle 236, and the baffle 238, and is discharged to the refrigerant return pipe 334. Note that the refrigerant flow mode is not limited to the present embodiment.

[0151] For example, in other embodiments, the refrigerant supplied from the refrigerant supply pipe 332 to the reaction vessel 110 flows into the baffle 232, passes through the baffle 234, and is discharged into the refrigerant return pipe 334. Also, the refrigerant supplied from the refrigerant supply pipe 332 to the reaction vessel 110 flows into the baffle 238, passes through the baffle 236, and is discharged into the refrigerant return pipe 334. Further, in other embodiments, each of the baffle 232, the baffle 234, the baffle 236, and the baffle 238 is configured to be able to independently control the flow rate of the refrigerant supplied to each baffle.

[0152] FIG. 4 shows a schematic plan view of an example of the reaction vessel 110. In the present embodiment, (i) the baffle 232, the baffle 234, the baffle 236, and the baffle 238, (ii) the serpentine cooling pipes 242, the serpentine cooling pipes 244, the serpentine cooling pipes 246, and the serpentine cooling pipes 248, and (iii) the serpentine cooling pipes 252, the serpentine cooling pipes 254, the serpentine cooling pipes 256, and the serpentine cooling pipes 258 are arranged concentrically.

[0153] In the present embodiment, the serpentine cooling pipes 242, the serpentine cooling pipes 244, the serpentine cooling pipes 246, and the serpentine cooling pipes 248 are arranged on substantially the same circumference. Also, in the present embodiment, (i) the baffle 232, the baffle 234, the baffle 236, and the baffle 238 and (ii) the serpentine cooling pipes 252, the serpentine cooling pipes 254, the serpentine cooling pipes 256, and the serpentine cooling pipes 258 are arranged on substantially the same circumference.

[0154] That is, in the cross-section at a specific position of the straight body portion 312, the centers of the cross-sections of the baffles 232, 234, 236, and 238 and the centers of the cross-sections of the serpentine cooling pipes 252, 254, 256, and 258 are arranged on substantially the same circumference. The cross-section at the specific position of the straight body portion 312 is a plane (the xy plane in the figure) perpendicular to the extending direction of the straight body portion 312 (the z direction in the figure), passes through the centers of the serpentine cooling pipes 252, 254, 256, and 258, and may be a cross-section obtained by cutting the reaction vessel 110. In this case, the width of each pipe in the cross-section coincides with the diameter of each pipe.

[0155] In the present embodiment, the baffles 232, 234, 236, and 238 are arranged at positions substantially symmetric around the central axis of the reaction vessel 110. The serpentine cooling pipes 242, 244, 246, and 248 are arranged at positions substantially symmetric around the central axis of the reaction vessel 110. The serpentine cooling pipes 252, 254, 256, and 258 are arranged at positions substantially symmetric around the central axis of the reaction vessel 110.

[0156] As shown in FIG. 4, the serpentine cooling pipe 252 is arranged at a position between the baffle 232 and the baffle 234. The serpentine cooling pipe 254 is arranged at a position between the baffle 234 and the baffle 236. The serpentine cooling pipe 256 is arranged at a position between the baffle 236 and the baffle 238. The serpentine cooling pipe 258 is arranged at a position between the baffle 238 and the baffle 232. The outer diameters of the serpentine cooling pipes 252, 254, 256, and 258 may be smaller than the width Bw of the baffles 232, 234, 236, and 238.

[0157] In the present embodiment, the diameter of the circle in which the meandering cooling pipes 242, 244, 246, and 248 are arranged is smaller than the diameter of the circle in which the meandering cooling pipes 252, 254, 256, and 258 are arranged. According to the present embodiment, in the diameter direction of the straight body portion 312 of the reaction vessel 110, the meandering cooling pipes can be arranged in multiple stages. Thereby, for example, compared with the case where a large ring-shaped or spiral-shaped pipe is arranged inside the reaction vessel 110, the degree of freedom in arranging the internal structures is improved. As a result, a polymerization apparatus 100 having excellent cooling efficiency can be manufactured.

[0158] The diameter D of the virtual circle on the outer periphery of the meandering cooling pipes 242, 244, 246, and 248 c is not particularly limited, but is preferably larger than the diameter D of the rotation region of the stirring blade 124. d D c / D d is preferably 1.1 or more, and more preferably 1.2 or more.

[0159] In the present embodiment, the distance between each of the meandering cooling pipes 252, 254, 256, and 258 and the inner surface of the straight body portion 312 is all P. C1 Similarly, the distance between each of the meandering cooling pipes 242, 244, 246, and 248 and the inner surface of the straight body portion 312 is all P. C2 As shown in FIG. 4, in the present embodiment, P C2 > P C1 is satisfied.

[0160] The above P C1 and P C2 are not particularly limited, but P C1 is preferably set so that the distance between the outer periphery of each meandering cooling pipe and the inner surface of the straight body portion 312 is 40 mm or more. Note that P C1 may be set to 40 mm or more. The above distance or P C1When it is less than 40 mm, polymer scale may easily adhere between the inner wall surface of the reaction vessel 110 and the serpentine cooling pipe 150 near the gas-liquid interface inside the reaction vessel 110.

[0161] Similarly, the distance P between the serpentine cooling pipe 242 and the serpentine cooling pipe 252 C is preferably 40 mm or more. The distance Pc is determined, for example, by calculating the minimum value of the distance between the outer periphery of the serpentine cooling pipe 242 and the outer periphery of the serpentine cooling pipe 252 in the above cross section. P C When it is less than 40 mm, polymer scale may easily adhere.

[0162] The distance between a specific serpentine cooling pipe and the inner surface of the straight body portion 312 may be determined as the shortest distance between the two in a cross section perpendicular to the extending direction of the straight body portion 312 and passing through the center of the specific serpentine cooling pipe. The distance between each serpentine cooling pipe and the inner surface of the straight body portion 312 is determined, for example, by calculating the minimum value of the distance between the center line along the extending direction of each serpentine cooling pipe and the inner surface of the straight body portion 312 in the above cross section. In this embodiment, the center line along the extending direction of each of the above serpentine cooling pipes is curved in an arc shape. Details of the above distance will be described later.

[0163] As shown in FIG. 4, in the cross section at a specific position of the straight body portion 312, the cross sections of the meandering cooling pipes 242, 244, 246, and 254 have an arc shape. Similarly, the cross sections of the meandering cooling pipes 252, 254, 256, and 258 have an arc shape. The shapes of the cross sections of the meandering cooling pipes 242, 244, 246, and 254 and the shapes of the cross sections of the meandering cooling pipes 252, 254, 256, and 258 may be similar. For example, when the cross sections of the meandering cooling pipes 242 and 252 have an arc shape, the central angle of the arc of the meandering cooling pipe 242 and the central angle of the arc of the meandering cooling pipe 252 may be substantially the same. The same may apply to the meandering cooling pipes 244 and 254, the meandering cooling pipes 246 and 256, and the meandering cooling pipes 248 and 258.

[0164] When the shape of the above-mentioned meandering cooling pipe is on an arc, the magnitude of the central angle of the arc may be 270 degrees or less. The magnitude of the central angle of the arc may also be 240 degrees or less, 210 degrees or less, 180 degrees or less, 150 degrees or less, 120 degrees or less, 90 degrees or less, or 60 degrees or less.

[0165] Also, in the present embodiment, the length in at least one extending direction of the meandering cooling pipes 252, 254, 256, and 258 (which is the length of the arc in the figure) is smaller than 2 / 3 of the length of the inner circumference of the straight body portion 312. The above-mentioned length in the extending direction (which is the length of the arc in the figure) may be 1 / 2 or less of the length of the inner circumference of the straight body portion 312, may be smaller than 1 / 2 of the length of the inner circumference of the straight body portion 312, may be 1 / 3 or less of the length of the inner circumference of the straight body portion 312, may be smaller than 1 / 3 of the length of the inner circumference of the straight body portion 312, may be 1 / 4 or less of the length of the inner circumference of the straight body portion 312, may be smaller than 1 / 4 of the length of the inner circumference of the straight body portion 312, may be 1 / 6 or less of the length of the inner circumference of the straight body portion 312, or may be smaller than 1 / 6 of the length of the inner circumference of the straight body portion 312.

[0166] As described above, the coiled cooling pipe described in Japanese Patent Application Laid-Open No. 7-233206 has a substantially circular shape. That is, the central angle of the arc of the cooling pipe is approximately 360 degrees. Therefore, it is not possible to arrange the baffle and the coiled cooling pipe on substantially the same circumference. On the other hand, according to the present embodiment, at least one of the one or more serpentine cooling pipes 150 arranged closer to the inside of the straight body portion 312 than the serpentine cooling pipe 140 has the above-described configuration, so that it can be arranged between the two baffles 130. Thereby, while reducing the influence of the serpentine cooling pipe 150 on the mixing performance of the polymerization apparatus 100, the heat transfer area of the entire apparatus can be increased.

[0167] The inner surface of the straight body portion 312 may be an example of the inner wall surface of the reactor. The serpentine cooling pipe 252 may be an example of the first cooling pipe having the smallest distance from the inner wall surface of the reactor. The serpentine cooling pipe 254 may be an example of the first cooling pipe having the smallest distance from the inner wall surface of the reactor. The serpentine cooling pipe 256 may be an example of the first cooling pipe having the smallest distance from the inner wall surface of the reactor. The serpentine cooling pipe 258 may be an example of the first cooling pipe having the smallest distance from the inner wall surface of the reactor.

[0168] (Example of another embodiment) In the present embodiment, an example of the polymerization apparatus 100 has been described by taking as an example the case where the serpentine cooling pipes are multiplexed in a double layer outward from the center of the straight body portion 312. However, the polymerization apparatus 100 is not limited to the present embodiment. In other embodiments, the serpentine cooling pipes may be multiplexed in a triple or more layer outward from the center of the straight body portion 312. It is preferable that the serpentine cooling pipes are multiplexed in a double to five-fold layer outward from the center of the straight body portion 312.

[0169] FIG. 5 schematically shows an example of the internal structure of the baffle 232. Note that the baffles 234, 236, and 238 may also have the same internal structure as the baffle 232. In the present embodiment, the baffle 232 has a double-tube structure including an inner tube 510 and an outer tube 520. The baffle 232 has an inlet 512 for allowing a refrigerant to flow into the inner tube 510 and an outlet 522 for allowing the refrigerant to flow out from the inside of the outer tube 520.

[0170] In the present embodiment, the inlet 512 of the baffle 232 is connected to the refrigerant supply pipe 332 via a pipe 532 and a flow rate adjustment valve 542. Thus, by adjusting the opening degree of the flow rate adjustment valve 542, the flow rate of the refrigerant flowing into the baffle 232 is adjusted. Similarly, the inlet 512 of the baffle 234 is connected to the refrigerant supply pipe 332 via a pipe 534 and a flow rate adjustment valve 544.

[0171] In the present embodiment, the outlet 522 of the baffle 232 is connected to the refrigerant return pipe 334 and the baffle 234 via a connecting portion 342. As shown in FIG. 5, in the present embodiment, the connecting portion 342 includes a pipe 552, a flow rate adjustment valve 554, a pipe 556, and a flow rate adjustment valve 558.

[0172] The pipe 552 connects the outlet 522 and the refrigerant return pipe 334. The flow rate adjustment valve 554 is disposed in the middle of the pipe 552 to adjust the flow rate of the refrigerant flowing through the pipe 552. The pipe 556 connects the outlet 522 and the baffle 234. More specifically, the pipe 556 connects a position on the pipe 552 between the flow rate adjustment valve 554 and the outlet 522 of the baffle 232 and a position on the pipe 534 between the flow rate adjustment valve 544 and the inlet 512 of the baffle 234. The flow rate adjustment valve 558 is disposed in the middle of the pipe 556 to adjust the flow rate of the refrigerant flowing through the pipe 556.

[0173] (An example of another embodiment) In this embodiment, as an example of the polymerization apparatus 100, a case is described where the baffle 232 has a double-tube structure, the refrigerant flowing in from below the baffle 232 flows out from below the baffle 232, and flows into the baffle 234 from below the baffle 234. However, the polymerization apparatus 100 is not limited to this embodiment.

[0174] In other embodiments, the piping may be configured such that the refrigerant flowing in from below the baffle 232 flows out from above the baffle 232 and flows into the baffle 234 from above the baffle 234. In still other embodiments, the baffle 232 may be a single tube.

[0175] FIG. 6 schematically shows an example of the structure of the serpentine cooling tube 252. Note that the other serpentine cooling tubes 140 and 150 may also have the same structure as the serpentine cooling tube 252. As shown in FIG. 6, the serpentine cooling tube 252 extends in the z direction while repeatedly bending. In this embodiment, the serpentine cooling tube 252 has a serpentine portion 610. The serpentine portion 610 has a plurality of extending portions 612 and one or more bending portions 614.

[0176] In the serpentine cooling tube 252 described in relation to FIG. 6, the serpentine portion 610 has 15 extending portions 612 and 14 bending portions 614. The number of extending portions 612 in a single serpentine portion 610 may be referred to as the number of stages. As shown in FIG. 2, in this embodiment, the serpentine cooling tube 252 extends on the xy plane at the extending portion 612 and bends in the z direction at the bending portion 614.

[0177] In this embodiment, each of the plurality of extending portions 612 extends on a substantially the same plane. For example, even when the extending portions 612 are designed to extend on the same plane, due to errors associated with manufacturing, installation, etc., the extending portions 612 may not completely extend on the same plane. In such a case, the extending portions 612 may be regarded as extending on a substantially the same plane. Note that it should be noted that when the extending portions 612 extend on a substantially the same plane, it is not limited to the above example.

[0178] In this regard, the meandering cooling pipe 252 is different from a spiral cooling pipe. Since the meandering cooling pipe 252 meanders and extends, the surface area per installation area can be larger than when the cooling pipe extends in a spiral shape.

[0179] As described in relation to FIG. 4, in the present embodiment, each of the plurality of extending portions 612 extends while curving in the xy plane. The length P in the extending direction of each of the plurality of extending portions 612 L may be the same, or the lengths in the extending directions of at least two of the extending portions 612 may be different. In the present embodiment, P L is the length of the extending portion 612 in the xy plane. P L may be the length of the extending portion 612 in the xy plane passing through the center of the cross section of the extending portion 612 when the extending portion 612 is cut by a plane substantially perpendicular to the extending direction of the extending portion 612 (in this case, a plane substantially parallel to the z direction).

[0180] As described above, P L may be smaller than 2 / 3 of the inner peripheral length of the straight body portion 312. In this regard, the meandering cooling pipe 252 is different from the coiled cooling pipe described in Japanese Patent Laid-Open No. 7-233206.

[0181] In a single meandering portion 610, among the plurality of extending portions 612, the P of more than 1 / 2 of the number of extending portions 612 L may be smaller than 2 / 3 of the inner peripheral length of the straight body portion 312. The above P L may be 1 / 2 or less of the inner peripheral length of the straight body portion 312, may be smaller than 1 / 2 of the inner peripheral length of the straight body portion 312, may be 1 / 3 or less of the inner peripheral length of the straight body portion 312, may be smaller than 1 / 3 of the inner peripheral length of the straight body portion 312, may be 1 / 4 or less of the inner peripheral length of the straight body portion 312, may be smaller than 1 / 4 of the inner peripheral length of the straight body portion 312, may be 1 / 6 or less of the inner peripheral length of the straight body portion 312, or may be smaller than 1 / 6 of the inner peripheral length of the straight body portion 312.

[0182] Among the plurality of extension portions 612, P of the number of extension portions 612 exceeding 2 / 3 L may be smaller than 2 / 3 of the inner circumference length of the straight barrel portion 312. The above P L may be 1 / 2 or less of the inner circumference length of the straight barrel portion 312, may be smaller than 1 / 2 of the inner circumference length of the straight barrel portion 312, may be 1 / 3 or less of the inner circumference length of the straight barrel portion 312, may be smaller than 1 / 3 of the inner circumference length of the straight barrel portion 312, may be 1 / 4 or less of the inner circumference length of the straight barrel portion 312, may be smaller than 1 / 4 of the inner circumference length of the straight barrel portion 312, may be 1 / 6 or less of the inner circumference length of the straight barrel portion 312, or may be smaller than 1 / 6 of the inner circumference length of the straight barrel portion 312.

[0183] In one embodiment, at least one of the plurality of extension portions 612 curves and extends on a substantially the same plane. For example, at least one of the plurality of extension portions 612 extends along an arc or an elliptical arc virtually arranged on the xy plane. In other embodiments, at least one of the plurality of extension portions 612 extends linearly on a substantially the same plane.

[0184] In the present embodiment, two of the plurality of extension portions 612 extend on two substantially parallel planes. For example, two adjacent extension portions 612 extend on two substantially parallel planes. Thereby, a meandering portion 610 extending in a ladder shape is obtained. In other embodiments, two of the plurality of extension portions 612 may extend on two non-parallel planes. For example, two adjacent extension portions 612 extend on two intersecting planes. Thereby, a meandering portion 610 extending in a zigzag shape is obtained.

[0185] In this embodiment, each of the one or more bent portions 614 connects the ends of two adjacent extending portions 612. In the embodiment shown in FIG. 6, each of the one or more bent portions 614 includes a portion bent in the z direction. Thus, the meandering portion 610 extends in the z direction while bending. The shape of the bent portion 614 is not particularly limited. The shape of a cross section (sometimes referred to as a longitudinal section) obtained by cutting the bent portion 614 with a plane parallel to the extending direction of the meandering cooling pipe 252 and passing through the center of the bent portion 614 may have a continuously bent shape or may have a shape composed of a plurality of straight lines. Examples of the continuously bent shape include an arc shape or an elliptical arc shape. The bent portion 614 may be composed of a portion having a continuously bent shape and a portion having a shape composed of one or more straight lines.

[0186] The diameter of the flow path of the meandering cooling pipe 252 is not particularly limited, but the above diameter is preferably 10 to 200 mm. The number of extending portions 612 (sometimes referred to as the number of stages) included in a single meandering cooling pipe 252 is not particularly limited, but the above number of stages is preferably 2 to 70. The size of the distance (sometimes referred to as the pitch) Pp between two adjacent extending portions 612 is not particularly limited, but the above Pp is preferably 60 mm or more. When Pp is less than 60 mm, polymer scale may easily adhere.

[0187] (An example of another embodiment) In this embodiment, an example of the meandering cooling pipe 252 has been described by taking as an example the case where the meandering cooling pipe 252 extends in the z direction while bending. However, the meandering cooling pipe 252 is not limited to this embodiment. In other embodiments, the meandering cooling pipe 252 may extend in the x direction or the y direction while bending.

[0188] In this embodiment, an example of the serpentine cooling pipe 252 has been described by taking the case where the extending portion 612 extends on the xy plane and the bending portion 614 bends in the z direction as an example. However, the serpentine cooling pipe 252 is not limited to this embodiment. In other embodiments, the bending portion 614 may include a first bending member that bends on the xy plane and a second bending member that bends in the z direction.

[0189] FIG. 7 schematically shows another example of the structure of the serpentine cooling pipe 252. In this embodiment, the serpentine cooling pipe 252 extends in the z direction while bending in a zigzag shape. In this embodiment, the serpentine cooling pipe 252 includes a supply pipe 702, an outflow pipe 704, and a serpentine portion 710. In this embodiment, the serpentine portion 710 has a plurality of extending portions 712 and one or more bending portions 714.

[0190] The supply pipe 702 allows the refrigerant supplied to the serpentine portion 710 to flow therethrough. The outflow pipe 704 allows the refrigerant flowing out from the serpentine portion 710 to flow therethrough. The serpentine portion 710 extends in the z direction while repeatedly bending.

[0191] The serpentine cooling pipe 252 described in relation to FIG. 7 is different from the serpentine cooling pipe 252 described in relation to FIG. 6 in that the plurality of extending portions 712 are not arranged substantially parallel. For features other than the above differences, the serpentine cooling pipe 252 described in relation to FIG. 7 may have the same configuration as the serpentine cooling pipe 252 described in relation to FIG. 6.

[0192] FIG. 8 schematically shows another example of the structure of the serpentine cooling pipe 252. In this embodiment, the serpentine cooling pipe 252 includes a supply pipe 702, an outflow pipe 704, and a serpentine portion 810. In this embodiment, the serpentine portion 810 has a serpentine portion 812, a connecting portion 822, a serpentine portion 814, a connecting portion 824, and a serpentine portion 816.

[0193] In the present embodiment, the meandering portion 810 extends in the z direction while repeatedly bending. In the present embodiment, the meandering portion 812 extends in the x direction while repeatedly bending. The meandering portion 812 extends, for example, in the positive direction of the x direction. In the present embodiment, the connecting portion 822 connects the meandering portion 812 and the meandering portion 814. In the present embodiment, the meandering portion 814 extends in the x direction while repeatedly bending. The meandering portion 814 extends, for example, in the negative direction of the x direction. In the present embodiment, the connecting portion 824 connects the meandering portion 814 and the meandering portion 816. In the present embodiment, the meandering portion 816 extends in the x direction while repeatedly bending. The meandering portion 814 extends, for example, in the positive direction of the x direction.

[0194] Each of the meandering portion 812, the meandering portion 814, and the meandering portion 816 may have the same configuration as the meandering portion 610. For example, at least one of the meandering portion 812, the meandering portion 814, and the meandering portion 816 has a plurality of extending portions and one or more bending portions. In this case, each of the plurality of extending portions may extend on the xy plane, may extend on the xz plane, or may extend on the yz plane.

[0195] FIG. 9 schematically shows an example of a main part of the polymerization apparatus 900. The polymerization apparatus 900 is different from the polymerization apparatus 100 in that the pitch Pp of the meandering cooling pipe 140 and the pitch Pp of the meandering cooling pipe 150 are different. The polymerization apparatus 900 may have the same configuration as the polymerization apparatus 100 with respect to features other than the above differences.

[0196] The pitch Pp of the serpentine cooling pipe 140 may be larger than the pitch Pp of the serpentine cooling pipe 150. For example, when the viscosity of the slurry flowing inside the reaction vessel 110 is relatively high, the flow of the slurry becomes slow. When the flow of the slurry becomes slow, scale is likely to adhere to the surfaces of the serpentine cooling pipe 140, the serpentine cooling pipe 150, the straight body portion 312, and the like. An example of a case where the viscosity of the slurry is relatively high is the suspension polymerization of vinyl chloride. Even in such a case, since the serpentine cooling pipe 140 has a relatively large pitch Pp, the discharge flow generated by the stirring blade 124 reaches the serpentine cooling pipe 150 and the straight body portion 312 while maintaining sufficient momentum. Thereby, the flow state in the vicinity of the serpentine cooling pipe 140, the serpentine cooling pipe 150, the straight body portion 312, etc. is improved, and the adhesion of scale is prevented.

[0197] (An example of another embodiment) In another embodiment, the pitch Pp of the serpentine cooling pipe 140 may be smaller than the pitch Pp of the serpentine cooling pipe 150.

[0198] FIG. 10 schematically shows an example of the main part of the polymerization apparatus 1000. The polymerization apparatus 1000 is different from the polymerization apparatus 100 in that the number of stages of the serpentine cooling pipe 140 and the number of stages of the serpentine cooling pipe 150 are different. Regarding features other than the above differences, the polymerization apparatus 1000 may have the same configuration as the polymerization apparatus 100. Also, within a technically non - conflicting range, the polymerization apparatus 1000 may have the features of various polymerization apparatuses according to other embodiments.

[0199] In one embodiment, the number of stages of the serpentine cooling pipe 140 and the serpentine cooling pipe 150 is adjusted such that the position of the upper end of the serpentine cooling pipe 140 is lower than the position of the upper end of the serpentine cooling pipe 150. For example, when the viscosity of the slurry flowing inside the reaction vessel 110 is relatively high, scale may adhere to the gas-liquid interface or foaming may easily occur. An example of a case where the viscosity of the slurry is relatively high is the suspension polymerization of vinyl chloride. When foaming at the gas-liquid interface becomes intense, heat removal by the reflux condenser 180 is restricted. Even in such a case, by suppressing the height of the upper end of the serpentine cooling pipe 140 arranged closer to the stirring blade 124, the flow of the gas-liquid interface becomes active, and adhesion and foaming of the slurry can be suppressed. Preferably, the number of stages of the serpentine cooling pipe 140 is adjusted such that the position of the upper end of the serpentine cooling pipe 140 is lower than that of the stirring blade 124 arranged at the uppermost stage.

[0200] (An example of another embodiment) In another embodiment, the number of stages of the serpentine cooling pipe 140 and the serpentine cooling pipe 150 may be adjusted such that the position of the lower end of the serpentine cooling pipe 140 is higher than the position of the lower end of the serpentine cooling pipe 150. In yet another embodiment, the number of stages of the serpentine cooling pipe 140 is adjusted so that the serpentine cooling pipe 140 does not interfere with the rotation of the stirring blade 124.

[0201] FIG. 11 schematically shows an example of a main part of the polymerization apparatus 1100. The polymerization apparatus 1100 is different from the polymerization apparatus 100 in that it includes a serpentine cooling pipe 1160 between the serpentine cooling pipe 140 and the serpentine cooling pipe 150. Regarding features other than the above differences, the polymerization apparatus 1100 may have the same configuration as the polymerization apparatus 100. Also, within a range where there is no technical contradiction, the polymerization apparatus 1100 may have features of various polymerization apparatuses according to other embodiments.

[0202] FIG. 12 schematically shows an example of the main part of the polymerization apparatus 1200. The polymerization apparatus 1200 is different from the polymerization apparatus 100 in that it includes a serpentine cooling pipe 1252 having a semicircular cross section instead of the serpentine cooling pipes 252, 256, and 258. Regarding features other than the above differences, the polymerization apparatus 1200 may have the same configuration as the polymerization apparatus 100. Also, within a technically non - conflicting range, the polymerization apparatus 1200 may have features of various polymerization apparatuses according to other embodiments.

[0203] FIG. 13 schematically shows an example of the main part of the polymerization apparatus 1300. The polymerization apparatus 1300 is different from the polymerization apparatus 100 in that it includes serpentine cooling pipes 1351, 1352, 1353, 1354, 1355, and 1356 including a linearly extending extension part 612 instead of the serpentine cooling pipes 252, 254, 256, and 258 including a curved and extending extension part 612. Also, the polymerization apparatus 1300 is different from the polymerization apparatus 100 in that it includes baffles 1331, 1332, 1333, 1334, 1335, and 1336. Regarding features other than the above differences, the polymerization apparatus 1300 may have the same configuration as the polymerization apparatus 100. Also, within a technically non - conflicting range, the polymerization apparatus 1300 may have features of various polymerization apparatuses according to other embodiments.

[0204] In the present embodiment, the serpentine cooling pipes 1351, 1352, 1353, 1354, 1355, and 1355 are arranged at positions substantially symmetric around the central axis of the reaction vessel 110 on the sides of a virtual regular hexagon. Also, the baffles 1331, 1332, 1333, 1334, 1335, and 1336 are arranged at the vertices of the above - mentioned virtual regular hexagon.

[0205] According to this embodiment, the number of the meandering cooling pipes 140 is different from the number of the meandering cooling pipes 150. For example, the number of the meandering cooling pipes 140 is smaller than the number of the meandering cooling pipes 150. According to this embodiment, the shapes of the meandering cooling pipe 140 and the meandering cooling pipe 150 are not similar. For example, the extending portion 612 of the meandering cooling pipe 140 extends in a curved manner, and the extending portion 612 of the meandering cooling pipe 150 extends linearly.

[0206] (An example of another embodiment) In this embodiment, an example of the polymerization apparatus 1300 has been described by taking the case where the baffles 1331, 1332, 1333, 1334, 1335, and 1336 are arranged at the vertices of a virtual regular hexagon as an example. However, the polymerization apparatus 1300 is not limited to this embodiment.

[0207] In other embodiments, at least one of the baffles 1331, 1332, 1333, 1334, 1335, and 1336 may be arranged between the above-mentioned regular hexagon and the straight barrel portion 312. In still other embodiments, at least one of the baffles 1331, 1332, 1333, 1334, 1335, and 1336 may be arranged between the above-mentioned regular hexagon and a virtual circle in which the meandering cooling pipes 242, 244, 246, and 248 are arranged.

[0208] According to this embodiment, an example of the polymerization apparatus 1300 has been described by taking the case where the number of the meandering cooling pipes 140 is smaller than the number of the meandering cooling pipes 150 as an example. However, the polymerization apparatus 1300 is not limited to this embodiment. In other embodiments, the number of the meandering cooling pipes 140 may be larger than the number of the meandering cooling pipes 150.

[0209] According to this embodiment, an example of the polymerization apparatus 1300 has been described by taking as an example the case where the extending portion 612 of the meandering cooling pipe 140 extends in a curved manner and the extending portion 612 of the meandering cooling pipe 150 extends linearly. However, the polymerization apparatus 1300 is not limited to this embodiment. In other embodiments, the extending portion 612 of the meandering cooling pipe 140 may extend linearly and the extending portion 612 of the meandering cooling pipe 150 may extend in a curved manner.

[0210] (An example of another embodiment) In this embodiment, an example of the polymerization apparatus 1300 has been described by taking as an example the case where the diameter of the virtual circle 1403 is larger than the diameter of the virtual circle 1404 and smaller than the diameter of the virtual circle 1405. However, the polymerization apparatus 1300 is not limited to this embodiment. In other embodiments, the diameter of the virtual circle 1403 may be smaller than the diameter of the virtual circle 1404. In still other embodiments, the diameter of the virtual circle 1403 may be larger than the diameter of the virtual circle 1405.

[0211] FIG. 14 schematically shows an example of a main part of the polymerization apparatus 1400. The polymerization apparatus 1400 is different from the polymerization apparatus 100 in that a virtual circle 1403 in which baffles 232, 234, 236, and 238 are arranged is disposed between a virtual circle 1404 in which meandering cooling pipes 242, 244, 246, and 248 are arranged and a virtual circle 1405 in which meandering cooling pipes 252, 254, 256, and 258 are arranged. Regarding features other than the above differences, the polymerization apparatus 1400 may have the same configuration as the polymerization apparatus 100. Also, within a technically non - contradictory range, the polymerization apparatus 1400 may have features of various polymerization apparatuses according to other embodiments.

[0212] FIG. 15 schematically shows an example of the main part of the polymerization apparatus 1500. The polymerization apparatus 1500 is different from the polymerization apparatus 1400 in that the baffle 232 is arranged between the serpentine cooling pipes 242 and 252, the baffle 234 is arranged between the serpentine cooling pipes 244 and 254, the baffle 236 is arranged between the serpentine cooling pipes 246 and 256, and the baffle 238 is arranged between the serpentine cooling pipes 248 and 258. Regarding the features other than the above differences, the polymerization apparatus 1500 may have the same configuration as the polymerization apparatus 1400. Also, within a technically non - conflicting range, the polymerization apparatus 1500 may have the features of various polymerization apparatuses according to other embodiments.

[0213] FIG. 16 schematically shows an example of the main part of the polymerization apparatus 1600. The polymerization apparatus 1600 is different from the polymerization apparatus 100 in that it does not include the serpentine cooling pipes 244 and 248. Regarding the features other than the above differences, the polymerization apparatus 1600 may have the same configuration as the polymerization apparatus 100. Also, within a technically non - conflicting range, the polymerization apparatus 1600 may have the features of various polymerization apparatuses according to other embodiments.

[0214] For example, when the viscosity of the slurry flowing inside the reaction vessel 110 is relatively high, if the serpentine cooling pipes 140 and 150 are arranged in multiple stages in the radial direction of the straight body portion 312, the slurry may stay in the region between the serpentine cooling pipes 140 and 150. An example of a case where the viscosity of the slurry is relatively high is the suspension polymerization of vinyl chloride. Even in such a case, by changing the number of radial stages of the serpentine cooling pipes 140 and 150 along the circumferential direction of the straight body portion 312, the retention of the slurry is suppressed. As a result, the mixing of the slurry is promoted.

[0215] FIG. 17 schematically shows an example of a main part of a polymerization system 1700. In the present embodiment, the polymerization system 1700 includes a polymerization apparatus 100 and a controller 1710. Further, in the present embodiment, the polymerization system 1700 includes a stirring system 1702. The stirring system 1702 has a stirring shaft 122, stirring blades 1722, stirring blades 1724, stirring blades 1726, and a power mechanism 126. The polymerization apparatus 100 described in relation to FIG. 17 may have the same configuration as the polymerization apparatus 100 described in relation to FIG. 1, except that it includes stirring blades 1722, stirring blades 1724, and stirring blades 1726 instead of the plurality of stirring blades 124.

[0216] In the present embodiment, for the purpose of simplifying the explanation, an example of the polymerization system 1700 and the stirring system 1702 is described by taking the case where three stirring blades, namely, the stirring blades 1722, the stirring blades 1724, and the stirring blades 1726, are attached to the stirring shaft 122 as an example. However, the polymerization system 1700 and the stirring system 1702 are not limited to the present embodiment. In other embodiments, two stirring blades are attached to the stirring shaft 122 of the polymerization system 1700 and the stirring system 1702. In still other embodiments, in other embodiments, four or more stirring blades are attached to the stirring shaft 122 of the polymerization system 1700 and the stirring system 1702.

[0217] As described above, the stirring shaft 122 is rotatably arranged inside the reaction vessel 110. In particular, a part of the stirring shaft 122 is arranged inside the straight body portion 312 of the reaction vessel 110 and is configured to be rotatable. The stirring shaft 122 is attached to the reaction vessel 110 such that the extending direction of the stirring shaft 122 and the extending direction of the straight body portion 312 substantially coincide.

[0218] In this embodiment, the three stirring blades, namely the stirring blade 1722, the stirring blade 1724, and the stirring blade 1726, are attached at different positions in the extending direction of the stirring shaft 122. The stirring blade 1722 is attached at the uppermost position among the plurality of stirring blades. The stirring blade 1724 is arranged between the stirring blade 1722 and the stirring blade 1726. The stirring blade 1726 is attached at the lowermost position among the plurality of stirring blades.

[0219] In this embodiment, the stirring system 1702 stirs the liquid contained inside the reaction vessel 110 of the polymerization apparatus 100. Specifically, when the stirring shaft 122 rotates, the stirring blades 1722, 1724, and 1726 (which may sometimes be simply referred to as a plurality of stirring blades) attached to the stirring shaft 122 rotate, and as a result, the liquid contained inside the reaction vessel 110 is stirred.

[0220] In this embodiment, the controller 1710 controls the rotational speed of the stirring shaft 122. The controller 1710 controls the rotational speed of the stirring shaft 122, for example, by controlling the output of the power mechanism 126. In this embodiment, the controller 1710 controls the rotational speed of the stirring shaft 122 such that the rotational speed of the stirring shaft 122 satisfies the relationship shown in the following mathematical formula 1. (Mathematical formula 1) N(b / d)(L / D) / n ≦ 6.0

[0221] In mathematical formula 1, N represents the number of a plurality of stirring blades attached to the stirring shaft 122. As described above, in this embodiment, N is 3. b represents the maximum value [m] of the blade widths of the plurality of stirring blades. That is, b represents the blade width of the stirring blade with the largest blade width among the stirring blade 1722, the stirring blade 1724, and the stirring blade 1726. d represents the maximum value [m] of the blade diameters of the plurality of stirring blades. That is, d represents the blade diameter of the stirring blade with the largest blade diameter among the stirring blade 1722, the stirring blade 1724, and the stirring blade 1726.

[0222] L represents the length [m] in the extending direction of the straight cylindrical portion 312 of the reaction vessel 110. D represents the maximum value [m] of the diameters of a plurality of inscribed circles that are substantially inscribed in the straight cylindrical portion 312 in each of the cross-sections formed by a plurality of planes, which are planes substantially perpendicular to the extending direction of the straight cylindrical portion 312 (the vertical direction in the figure) and pass through the mounting positions of the respective stirring blades, when the straight cylindrical portion 312 is cut by the plurality of planes. When the reaction vessel 110 has a cylindrical straight cylindrical portion 312, D is the inner diameter [m] of the straight cylindrical portion 312. n represents the set value of the rotational speed [rps] of the stirring shaft 122.

[0223] Thereby, generation of coarse particles can be suppressed. As a result, the particle size distribution of the polymer becomes narrow. In addition, generation of fish eyes can be suppressed. Further, adhesion of scale can be suppressed.

[0224] The parameter represented by N(b / d)(L / D) / n described above represents the degree of stirring of the liquid when a liquid of about the rated capacity of the reaction vessel 110 is accommodated inside the reaction vessel 110. Therefore, the above parameter may be referred to as a stirring parameter.

[0225] In the present embodiment, the internal volume of the reaction vessel 110 may be 40 to 300 m 3 Moreover, the ratio (L / D) of the length L in the extending direction of the straight cylindrical portion 312 to the diameter D of the inscribed circle of the straight cylindrical portion 312 of the reaction vessel 110 may be 1.0 to 3.0. Thereby, the effect that the dimension of the straight cylindrical portion 312 of the reaction vessel 110, the dimension of at least one of the plurality of stirring blades 124, and the set value of the rotational speed of the stirring shaft 122 are determined so as to satisfy the relationship shown in Formula 1 can be obtained more reliably.

[0226] The controller 1710 preferably controls the rotational speed of the stirring shaft 122 so that the rotational speed of the stirring shaft 122 satisfies the relationship shown in the following Formula 2. (Formula 2) 0.05 ≦ N(b / d)(L / D) / n ≦ 6.0

[0227] In Formula 2, the definitions of N, b, d, L, D, and n are the same as those in Formula 1. As a result, the generation of coarse particles is further suppressed. The particle size distribution of the polymer becomes even narrower. In addition, the occurrence of fish eyes is further suppressed. Moreover, the adhesion of scale is further suppressed.

[0228] When the polymerization apparatus 100 includes one or more serpentine cooling pipes 140 or one or more serpentine cooling pipes 150 (that is, when the number of series of serpentine cooling pipes in the radial direction of the straight body portion 312 is 1 or more), it is preferable that the controller 1710 controls the rotational speed of the stirring shaft 122 so that the rotational speed of the stirring shaft 122 satisfies the relationship shown in the following Formula 3. (Formula 3) 0.15 ≦ N(b / d)(L / D) / n ≦ 5.5

[0229] In Formula 3, the definitions of N, b, d, L, D, and n are the same as those in Formula 1. As a result, the generation of coarse particles is further suppressed. The particle size distribution of the polymer becomes even narrower. In addition, the occurrence of fish eyes is further suppressed. Moreover, the adhesion of scale is further suppressed.

[0230] When a structure such as a cooling pipe is arranged inside the reaction vessel 110, it becomes difficult to control the flow state of the liquid accommodated inside the reaction vessel 110 as compared with the case where no structure is arranged inside the reaction vessel 110. In particular, the serpentine cooling pipe 140 and the serpentine cooling pipe 150 have a complex structure and can interfere with the stirring of the liquid in the extending direction of the straight body portion 312. Therefore, when the serpentine cooling pipe 140 or the serpentine cooling pipe 150 is arranged inside the reaction vessel 110, it becomes more difficult to control the stirring state of the liquid.

[0231] Therefore, when a structure such as a cooling pipe is arranged inside the reaction vessel 110, it is preferable to maintain the value of the stirring parameter within a narrower numerical range (i.e., 0.15 to 5.5) compared to the case where no structure is arranged inside the reaction vessel 110. Further, even when a structure such as a cooling pipe is arranged inside the reaction vessel 110, when the relationship represented by Formula 3 holds, a polymer of the same quality as that in the case where no structure such as a cooling pipe is arranged inside the reaction vessel 110 can be produced.

[0232] In this case, the ratio of the maximum value of the distance Pp between two adjacent stretching portions 612 to the length L in the stretching direction of the straight cylindrical portion 312 may be 0.5 to 15%. The ratio of the minimum value P of the distance between one or more serpentine cooling pipes 140 or one or more serpentine cooling pipes 150 and the inner wall surface of the straight cylindrical portion 312 to the inner diameter D of the straight cylindrical portion 312 C1 may be 0.5 to 10%. The ratio of the maximum value P of the distance between one or more serpentine cooling pipes 140 or one or more serpentine cooling pipes 150 and the inner wall surface of the straight cylindrical portion 312 to the inner diameter D of the straight cylindrical portion 312 C2 may be 1 to 30%.

[0233] When the polymerization apparatus 100 includes one or more serpentine cooling pipes 140 and one or more serpentine cooling pipes 150 (that is, when the number of series of serpentine cooling pipes in the radial direction of the straight cylindrical portion 312 is 2 or more), the controller 1710 preferably controls the rotation speed of the stirring shaft 122 so that the rotation speed of the stirring shaft 122 satisfies the relationship shown in the following Formula 4. (Formula 4) 0.3 ≦ N(b / d)(L / D) / n ≦ 5.5

[0234] In Formula 4, the definitions of N, b, d, L, D, and n are the same as those in Formula 1. Thereby, the generation of coarse particles is further suppressed. The particle size distribution of the polymer becomes narrower. Further, the occurrence of fish eyes is further suppressed. In addition, the adhesion of scale is further suppressed. When the relationship represented by Formula 4 holds, particularly, the effect of suppressing the occurrence of fish eyes is particularly remarkable.

[0235] As described above, the meandering cooling pipes 140 and 150 have a complex structure and may interfere with the stirring of the liquid in the extending direction of the straight body portion 312. In particular, when the number of series of the meandering cooling pipes in the radial direction of the straight body portion 312 is 2 or more, the degree of the above interference becomes remarkable.

[0236] Therefore, when the number of series of the meandering cooling pipes in the radial direction of the straight body portion 312 is 2 or more, it is preferable to maintain the value of the stirring parameter within a narrower numerical range (that is, 0.3 to 5.5) as compared with the case where no structure is arranged inside the reaction vessel 110. Further, even when the number of series of the meandering cooling pipes in the radial direction of the straight body portion 312 is 2 or more, when the relationship represented by Formula 4 holds, a polymer of the same quality as that in the case where no structure such as a cooling pipe is arranged inside the reaction vessel 110 can be produced.

[0237] In this case, the ratio of the maximum value of the distance Pp between two adjacent extending portions 612 to the length L in the extending direction of the straight body portion 312 may be 0.5 to 15%. The ratio of the minimum value L1 of the distance between one or more meandering cooling pipes 140 or one or more meandering cooling pipes 150 and the inner wall surface of the straight body portion 312 to the inner diameter D of the straight body portion 312 may be 0.5 to 10%. The ratio of the maximum value L2 of the distance between one or more meandering cooling pipes 140 or one or more meandering cooling pipes 150 and the inner wall surface of the straight body portion 312 to the inner diameter D of the straight body portion 312 may be 1 to 30%.

[0238] The polymerization system 1700 may be an example of a reaction apparatus. The polymerization system 1700 may be an example of a batch-type reaction apparatus. The stirring system 1702 may be an example of a stirring apparatus. The controller 1710 may be an example of a control unit or a control device. The stirring blade 1722 may be an example of a first stirring blade. The stirring blade 1724 may be an example of a third stirring blade. The stirring blade 1726 may be an example of a second stirring blade. The power mechanism 126 may be an example of a driving unit.

[0239] FIG. 18 schematically shows an example of the attachment positions of the stirring blades on the stirring shaft 122. In the present embodiment, taking the case where the blade diameters of the stirring blades 1722, 1724, and 1726 are all di and the blade widths of the stirring blades 1722, 1724, and 1726 are all bi as an example, an example of the attachment positions of the stirring blades on the stirring shaft 122 will be described. Note that in other embodiments, at least two of the stirring blades 1722, 1724, and 1726 may have different blade diameters. Also, at least two of the stirring blades 1722, 1724, and 1726 may have different blade widths.

[0240] In FIG. 18, the dashed-dotted line 1820 indicates the rotation axis of the stirring shaft 122. The dashed-dotted line 1822 indicates the attachment position of the stirring blade 1722 on the stirring shaft 122. The dashed-dotted line 1824 indicates the attachment position of the stirring blade 1724 on the stirring shaft 122. The dashed-dotted line 1826 indicates the attachment position of the stirring blade 1726 on the stirring shaft 122.

[0241] In the present embodiment, the minimum value of the distance between the attachment positions of the plurality of stirring blades on the stirring shaft 122 and the position corresponding to one end of the straight body portion 312 on the stirring shaft 122 may be 0.1 to 0.45 times the length L of the straight body portion 312 in the extending direction. For example, the distance Z between the attachment position of the stirring blade 1722 on the stirring shaft 122 and the position 1842 corresponding to the upper end 1832 of the straight body portion 312 on the stirring shaft 122 is set to be 0.1 to 0.45 times the length L of the straight body portion 312 in the extending direction.

[0242] In the present embodiment, the stirring blade 1726 on the stirring shaft 122 is disposed between the first position 1852 and the second position 1854 of the stirring shaft 122. The attachment position of the stirring blade 1726 on the stirring shaft 122 may be the position of the midpoint of the blade width of the stirring blade 1726 on the stirring shaft 122. In FIG. 18, the attachment position of the stirring blade 1726 is represented as the intersection of the dashed-dotted line 1820 and the dashed-dotted line 1826.

[0243] The first position 1852 is located above the second position 1854 when the stirring shaft 122 is attached to the straight cylindrical portion 312. Also, the first position 1852 is located above the position 1844 corresponding to the lower end 1834 of the straight cylindrical portion 312 on the stirring shaft 122. The distance between the first position 1852 and the position 1844 corresponding to the lower end 1834 of the straight cylindrical portion 312 on the stirring shaft 122 may be 0.25 times or less of the inner diameter D of the straight cylindrical portion 312.

[0244] Also, the second position 1854 is located below the position 1844 corresponding to the lower end 1834 of the straight cylindrical portion 312 on the stirring shaft 122 when the stirring shaft 122 is attached to the straight cylindrical portion 312. The distance between the second position 1854 and the position 1844 corresponding to the lower end 1834 of the straight cylindrical portion 312 on the stirring shaft 122 may be 0.1 times or less of the inner diameter D of the straight cylindrical portion 312.

[0245] In the present embodiment, the stirring blade 1724 is attached near (N - 1) third positions obtained by equally dividing the interval between the attachment position of the stirring blade 1722 and the attachment position of the stirring blade 1726 into (N - 1) parts. In the present embodiment, since N = 3, the stirring blade 1724 is attached at the position that bisects the interval between the attachment position of the stirring blade 1722 and the attachment position of the stirring blade 1726. In this case, the distance C ia between the attachment position of the stirring blade 1722 and the attachment position of the stirring blade 1724 ib substantially coincides with the distance C

[0246] Note that the distance between the stirring blade 1724 and the above third position may be 0.5 times or less of the ratio (D / N) of the inner diameter D of the straight cylindrical portion 312 to the number N of the plurality of stirring blades. Also, when (N - 2) stirring blades 1724 are arranged between the stirring blade 1722 and the stirring blade 1726, the maximum value of the distances between the (N - 2) stirring blades 1724 and the corresponding third positions may be 0.5 times or less of the ratio (D / N) of the inner diameter D of the straight cylindrical portion 312 to the number N of the plurality of stirring blades.

[0247] One stirring blade 1724 may be an example of the (N - 2) third stirring blades. The mounting position of the stirring blade 1722 may be an example of the first mounting position. The mounting position of the stirring blade 1726 may be an example of the second mounting position.

[0248] FIG. 19 schematically shows an example of the system configuration of the polymerization system 1900. In the present embodiment, the polymerization system 1900 includes a polymerization apparatus 100 and a controller 1910. In the present embodiment, the controller 1910 has a stirring control unit 1912 and a charging control unit 1914. The polymerization apparatus 100 may have the same configuration as the polymerization apparatus 100 described in relation to FIG. 1 or FIG. 17.

[0249] In the present embodiment, the polymerization system 1900 may include one or more monomer storage tanks 1922, one or more pumps 1932, and one or more flow meters 1942. The polymerization system 1900 may include one or more aqueous medium storage tanks 1924, one or more pumps 1934, and one or more flow meters 1944. The polymerization system 1900 may include one or more dispersion aid storage tanks 1926, one or more pumps 1936, and one or more flow meters 1946. The polymerization system 1900 may include one or more polymerization initiator storage tanks 1928, one or more pumps 1938, and one or more flow meters 1948. Various storage tanks, pumps, and / or flow meters may be provided for each type of raw material and / or auxiliary agent.

[0250] In the present embodiment, the controller 1910 controls the polymerization system 1900. For example, the controller 1910 controls the input amounts of various raw materials and auxiliary agents. The controller 1910 may control the timing at which various raw materials and / or auxiliary agents are introduced into the reaction vessel 110. The controller 1910 may control the temperature of the polymerization system. The controller 1910 may control the stirring state of the polymerization system.

[0251] In this embodiment, the stirring control unit 1912 controls the stirring state of the polymerization system. For example, the stirring control unit 1912 controls the rotation speed of the stirring shaft 122. The stirring control unit 1912 may have the same configuration as the controller 1710 described in relation to FIG. 17. For example, the stirring control unit 1912 controls the rotation speed of the stirring shaft 122 such that the rotation speed of the stirring shaft 122 satisfies the relationship shown in the above-described mathematical formula 1.

[0252] In this embodiment, the charging control unit 1914 controls the amounts of various raw materials and auxiliaries (sometimes referred to as the charging amounts) charged into the reaction vessel 110 and the timing at which the various raw materials and / or auxiliaries are charged into the reaction vessel 110. For the purpose of simplifying the explanation, in this embodiment, an example of the charging control unit 1914 will be described by taking the case where the charging control unit 1914 controls the masses of various raw materials and auxiliaries charged into the reaction vessel 110 as an example.

[0253] The charging control unit 1914 controls, for example, the mass of the monomer charged into the reaction vessel 110. The charging control unit 1914 may control the start and stop of the pump 1932 based on the transfer amount of the monomer measured by the flow meter 1942 and the preset charging amount of the monomer.

[0254] The charging control unit 1914 controls, for example, the mass of the aqueous solvent charged into the reaction vessel 110. The charging control unit 1914 may control the start and stop of the pump 1934 based on the transfer amount of the aqueous medium measured by the flow meter 1944 and the preset charging amount of the aqueous medium.

[0255] The charging control unit 1914 controls, for example, the mass of the dispersion aid charged into the reaction vessel 110. The charging control unit 1914 may control the start and stop of the pump 1936 based on the transfer amount of the dispersion aid measured by the flow meter 1946 and the preset charging amount of the dispersion aid.

[0256] The input control unit 1914 determines the input amount of the dispersion aid according to, for example, the state of the cooling pipe disposed inside the reaction vessel 110. According to one embodiment, when the number Nc [pieces] of virtual circles in the reaction vessel 110 is 1, 2, or 3, the input control unit 1914 satisfies the relationship shown in the above mathematical formulas A1, B1, C1, or D1 with the number Nc [pieces] of the above virtual circles and the above ratio CZ [mg / kg], and determines the input amount of the dispersion aid. According to another embodiment, when the number Nc [pieces] of virtual circles in the reaction vessel 110 is 4 or more, the input control unit 1914 satisfies the relationship shown in the above mathematical formulas A2, B2, C2, or D2 with the above ratio CZ [mg / kg], and determines the input amount of the dispersion aid.

[0257] The input control unit 1914 controls, for example, the mass of the polymerization initiator input into the reaction vessel 110. The input control unit 1914 may control the start and stop of the pump 1938 based on the transfer amount of the polymerization initiator measured by the flow meter 1948 and the preset input amount of the polymerization initiator.

[0258] In the present embodiment, the monomer storage tank 1922 stores the monomer. The pump 1932 transfers the monomer from the monomer storage tank 1922 to the reaction vessel 110. Thereby, the monomer is input into the reaction vessel 110. The pump 1932 may operate according to the instruction of the input control unit 1914. The flow meter 1942 measures the transfer amount of the monomer. The flow meter 1942 may output information indicating the transfer amount of the monomer to the input control unit 1914. The monomer may be stored and transferred as a powder, or the monomer may be stored and transferred as a liquid.

[0259] In the present embodiment, the aqueous medium storage tank 1924 stores the aqueous medium. The pump 1934 transfers the aqueous medium from the aqueous medium storage tank 1924 to the reaction vessel 110. Thereby, the aqueous medium is input into the reaction vessel 110. The pump 1934 may operate according to the instruction of the input control unit 1914. The flow meter 1944 measures the transfer amount of the aqueous medium. The flow meter 1944 may output information indicating the transfer amount of the aqueous medium to the input control unit 1914.

[0260] In this embodiment, the dispersion aid storage tank 1926 stores the dispersion aid. The pump 1936 transfers the dispersion aid from the dispersion aid storage tank 1926 to the reaction vessel 110. Thereby, the dispersion aid is introduced into the reaction vessel 110. The pump 1936 may operate according to the instruction of the introduction control unit 1914. The flow meter 1946 measures the transfer amount of the dispersion aid. The flow meter 1946 may output information indicating the transfer amount of the dispersion aid to the introduction control unit 1914. The dispersion aid may be stored and transferred as a powder, or the dispersion aid may be stored and transferred as a liquid.

[0261] In this embodiment, the polymerization initiator storage tank 1928 stores the polymerization initiator. The pump 1938 transfers the polymerization initiator from the polymerization initiator storage tank 1928 to the reaction vessel 110. Thereby, the polymerization initiator is introduced into the reaction vessel 110. The pump 1938 may operate according to the instruction of the introduction control unit 1914. The flow meter 1948 measures the transfer amount of the polymerization initiator. The flow meter 1948 may output information indicating the transfer amount of the polymerization initiator to the introduction control unit 1914. The polymerization initiator may be stored and transferred as a powder, or the polymerization initiator may be stored and transferred as a liquid.

[0262] The polymerization system 1900 may be an example of a reaction apparatus. The polymerization system 1900 may be an example of a batch reaction apparatus. The introduction control unit 1914 may be an example of a dispersion aid introduction unit. The pump 1936 may be an example of a dispersion aid introduction unit.

[0263] (An example of another embodiment) In this embodiment, an example of the polymerization system 1900 has been described by taking as an example the case where the introduction control unit 1914 controls the mass of various raw materials and auxiliaries introduced into the reaction vessel 110. However, the polymerization system 1900 is not limited to this embodiment. In other embodiments, the input amounts of various raw materials and auxiliaries may be in moles or in volume.

[0264] In this embodiment, taking as an example the case where raw materials and / or auxiliaries are transferred by a pump and the amount of the transferred raw materials and / or auxiliaries is measured by a flow meter, an example of a method for producing a polymer by suspension polymerization using a polymerization system 1900 was described. In this case, the above production method includes a raw material input step of charging a vinyl monomer, an aqueous medium, a dispersion aid, and a polymerization initiator into the reactor, and a polymerization step of polymerizing the vinyl monomer to produce a vinyl polymer. Further, in the raw material input step, when the number Nc [pieces] of a plurality of virtual circles is 1, 2, or 3, the number Nc [pieces] of the plurality of virtual circles and the ratio CZ [mg-dispersion aid / kg-monomer] of the mass of the dispersion aid to the mass of the vinyl monomer satisfy the relationships shown in the above-described mathematical formulas A1, B1, C1, or D1, or mathematical formulas A2, B2, C2, or D2, and the step of charging the dispersion aid is included. However, the polymerization system 1900 is not limited to this embodiment.

[0265] In other embodiments, first, the raw materials and / or auxiliaries are metered so that the relationships shown in the above-described mathematical formulas A1, B1, C1, or D1, or mathematical formulas A2, B2, C2, or D2 are satisfied. At this time, the above metering operation is controlled by, for example, an input control unit 1914. Next, the metered raw materials and / or auxiliaries are charged into the reaction vessel 110. Thereby, the number Nc [pieces] of the above virtual circles and the above ratio CZ [mg-dispersion aid / kg-monomer] satisfy the relationships shown in the above-described mathematical formulas A1, B1, C1, or D1, or mathematical formulas A2, B2, C2, or D2.

Examples

[0266] Hereinafter, reference examples and examples will be shown to specifically describe the present invention. Note that the present invention is not limited to the following examples.

[0267] (Reference Examples and Reference Comparative Examples) As a reference example, a polymerization example is shown in the case where the rotation speed of the stirring shaft 122 in the polymerization apparatus 100 satisfies the relationship shown in the above-described mathematical formula 1 with respect to the dimension of the straight body portion of the reaction vessel 110, at least one dimension of the plurality of stirring blades 124, and the set value of the rotation speed of the stirring shaft 122. Further, as a reference comparative example, a polymerization example is shown in the case where the rotation speed of the stirring shaft 122 in the polymerization apparatus 100 does not satisfy the relationship shown in the above-described mathematical formula 1 with respect to the dimension of the straight body portion of the reaction vessel 110, at least one dimension of the plurality of stirring blades 124, and the set value of the rotation speed of the stirring shaft 122.

[0268] (Polymerization conditions) In Reference Examples 1 to 13 and Reference Comparative Examples 1 to 5, deionized water, vinyl chloride monomer, and commercially available reagents were used, and the presence or absence of a serpentine cooling pipe inside the reaction vessel, the arrangement of the serpentine cooling pipe, the dimensions of the reaction vessel, and the rotation speed of the stirring shaft were changed to produce vinyl chloride polymers. In Reference Examples 1 to 13 and Reference Comparative Examples 1 to 5, the polymerization temperature and the supply temperature of the refrigerant were the same. Further, the above polymerization temperature was set based on the target value of the K value of the polymer.

[0269] (Evaluation) (Evaluation regarding resin particles) In each of Reference Examples 1 to 10 and Reference Comparative Example 1, the particle size distribution and the number of fish eyes of the produced polymer (which may be referred to as resin particles) were measured. As the particle size distribution of the polymer, the mass percentage of resin particles passing through a 60-mesh sieve, the mass percentage of resin particles passing through a 100-mesh sieve, and the mass percentage of resin particles passing through a 200-mesh sieve were measured.

[0270] The number of fish eyes was measured according to the following procedure. First, 100 parts by mass of a sample polymer, 50 parts by mass of bis(2-ethylhexyl) phthalate (DOP), 2.0 parts by mass of a Ba / Zn-based stabilizer, 5.0 parts by mass of epoxidized soybean oil, 0.1 part by mass of carbon black, and 0.5 part by mass of titanium dioxide were mixed to obtain a compound. Next, 50 g of the above compound was kneaded with a roll mill at 145 °C for 6 minutes and separated as a sheet with a thickness of 0.3 mm. Then, 100 cm of the above sheet 2The number of fish eyes was measured by visually measuring the number of transparent particles therein.

[0271] (Evaluation regarding scale) Also, in each of Reference Examples 1 to 10 and Reference Comparative Example 1, the polymerization test was repeated. After the polymerization test for a predetermined number of times was completed, the surface of the inner wall surface of the reaction vessel was visually observed to confirm the presence or absence of scale adhesion. Further, when the serpentine cooling pipe 140 and / or the serpentine cooling pipe 150 was disposed inside the reaction vessel, the surface of the serpentine cooling pipe 140 and / or the serpentine cooling pipe 150 was visually observed to confirm the presence or absence of scale adhesion.

[0272] (Reference Example 1) (Specifications of the polymerization apparatus 100) In Reference Example 1, a vinyl chloride polymer was produced using the polymerization apparatus 100 shown in FIG. 2. In Reference Example 1, a reaction vessel 110 having an internal volume of 80 m 3 was used. The diameter of the straight barrel portion 312 of the reaction vessel 110 was 3600 mm, and the length of the straight barrel portion 312 was 6800 mm. The ratio of the length L of the straight barrel portion 312 to the diameter D of the straight barrel portion 312 was 1.9.

[0273] Inside the reaction vessel 110, four serpentine cooling pipes 140 made of austenitic stainless steel cylindrical pipes with an outer diameter of 90 mm were arranged. The distance between the center of each of the four serpentine cooling pipes 140 and the central axis of the reaction vessel 110 was 1360 mm. Further, the four serpentine cooling pipes 140 were arranged at symmetric positions about the central axis of the reaction vessel 110. The number of stages of each of the four serpentine cooling pipes 140 was 12 stages. That is, each of the four serpentine cooling pipes 140 had 12 extending portions 612. In each of the four serpentine cooling pipes 140, the distance between adjacent extending portions 612 (which may be referred to as the pitch Pp) was 400 mm.

[0274] The distance P between the inner wall surface of the straight barrel portion 312 and the serpentine cooling pipe 140 with respect to the diameter D of the straight barrel portion 312 C2The ratio was 12.2%. The ratio of the pitch Pp to the length L of the straight body portion 312 was 5.9%.

[0275] Similarly, four serpentine cooling pipes 150 made of austenitic stainless steel cylindrical pipes with an outer diameter of 90 mm were installed inside the reaction vessel 110. The distance between the center of each of the four serpentine cooling pipes 150 and the central axis of the reaction vessel 110 was 1610 mm. Also, the four serpentine cooling pipes 150 were arranged at symmetric positions about the central axis of the reaction vessel 110. The number of stages of each of the four serpentine cooling pipes 150 was 12 stages. Also, in each of the four serpentine cooling pipes 150, the pitch Pp was 400 mm.

[0276] The ratio of the distance L1 between the inner wall surface of the straight body portion 312 and the serpentine cooling pipe 150 to the diameter D of the straight body portion 312 was 5.3%. The ratio of the pitch Pp to the length L of the straight body portion 312 was 5.9%.

[0277] Next, a stirring shaft 122 with three paddle blades attached was installed in the reaction vessel 110. Also, the rotational speed of the stirring shaft 122 was determined so as to satisfy the relationship of the above-described formula 1. In Reference Example 1, the value of the stirring parameter represented by N(b / d)(L / D) / n was 0.22. Note that the stirring energy applied to the contents of the reaction vessel 110 was in the range of 80 to 200 kgf·m / s·m 3 therein.

[0278] (Polymerization method) A vinyl chloride polymer was synthesized according to the following procedure. First, 32,900 kg of deionized water, 10.5 kg of a partially saponified polyvinyl alcohol with a saponification degree of 80.0 mol%, and 4.5 kg of hydroxypropyl methylcellulose with a methoxy substitution degree of 28.5 mass% and a hydroxypropyl substitution degree of 8.9% were made into an aqueous solution and charged into the reaction vessel 110. Next, 30,100 kg of vinyl chloride monomer was charged into the reaction vessel 110. Then, while stirring the mixed solution with the stirrer 120, polymerization initiator A, polymerization initiator B, and polymerization initiator C were press-fitted into the reaction vessel 110 with a pump.

[0279] As the polymerization initiator A, an isoparaffin solution containing di-2-ethylhexyl peroxydicarbonate was used. The addition amount of di-2-ethylhexyl peroxydicarbonate was 22.1 kg. As the polymerization initiator B, an isoparaffin solution containing t-butyl peroxyneodecanoate was used. The addition amount of t-butyl peroxyneodecanoate was 3.2 kg. As the polymerization initiator C, an isoparaffin solution containing cumyl peroxyneodecanoate was used. The addition amount of cumyl peroxyneodecanoate was 5.0 kg.

[0280] Next, hot water was passed through the jacket 170 to raise the temperature of the mixed solution inside the reaction vessel 110 to 57 °C, thereby initiating the polymerization. Also, when the temperature of the mixed solution inside the reaction vessel 110 reached 57 °C, the passage of cooling water to the baffle 130, the serpentine cooling pipe 140, the serpentine cooling pipe 150, and the jacket 170 was started. Then, when the polymerization conversion rate reached 20%, the reflux condenser 180 was operated.

[0281] Under the condition of maintaining the temperature of the mixed solution inside the reaction vessel 110 at 57 °C, when the pressure inside the reaction vessel 110 decreased by 0.09 MPa compared to the average pressure after the start of polymerization, all cooling was stopped. 18 minutes after all cooling was stopped, a sufficient amount of a triethylene glycol bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate] aqueous dispersion (concentration: 40% by mass) was introduced into the reaction vessel 110. Thereby, the polymerization reaction was completed, and a vinyl chloride polymer was obtained.

[0282] After the polymerization reaction was completed, the particle size distribution of the synthesized vinyl chloride resin and the number of fish eyes were measured. Also, in order to check the scale adhesion situation, taking the above polymerization test as one batch, the above polymerization test was repeated. After the polymerization tests for a predetermined number of times were completed, the scale adhesion situation inside the reaction vessel 110 was visually confirmed. The measurement results of the particle size distribution of the vinyl chloride resin, the measurement results of the number of fish eyes, and the confirmation results of the scale adhesion situation are shown in Table 1.

[0283] (Reference Examples 2 - 8) Using a polymerization apparatus similar to the polymerization apparatus 100 shown in FIG. 2, a vinyl chloride polymer was synthesized. In Reference Examples 2 - 8, a vinyl chloride polymer was synthesized by the same procedure as in Reference Example 1, except that the dimensions of the reaction vessel 110, the rotation speed of the stirring shaft 122, and the charged amount of the raw materials were different. In Reference Examples 2 - 8, the stoichiometric ratio and reaction temperature of each raw material were adjusted in the same manner as in Reference Example 1. Thereby, based on the experimental results of Reference Examples 1 - 8, the relationship between the set values of the dimensions of the reaction vessel, the dimensions of the stirring blades, and the rotation speed of the stirring shaft, and the quality of the produced polymer can be considered.

[0284] The outline of the specifications of the polymerization apparatuses in Reference Examples 2 - 8 is shown in Table 1. Also, the measurement results of the particle size distribution of the vinyl chloride resin, the measurement results of the number of fish eyes, and the confirmation results of the scale adhesion situation in Reference Examples 2 - 8 are shown in Table 1.

[0285] (Reference Example 9) Using a polymerization apparatus similar to the polymerization apparatus 100 shown in FIG. 2 except that it does not include the serpentine cooling pipe 140 and the serpentine cooling pipe 150, a vinyl chloride polymer was synthesized. In Reference Example 9, a vinyl chloride polymer was synthesized by the same procedure as in Reference Example 1, except that the dimensions of the reaction vessel 110, the presence or absence of the serpentine cooling pipe 140 and the serpentine cooling pipe 150, the rotation speed of the stirring shaft 122, and the charged amount of the raw materials were different. In Reference Example 9, the stoichiometric ratio and reaction temperature of each raw material were adjusted in the same manner as in Reference Example 1. Thereby, the influence of the structures arranged inside the reaction vessel can be considered.

[0286] Table 2 shows an overview of the specifications of the polymerization apparatus of Reference Example 9. Table 2 also shows the measurement results of the particle size distribution of the vinyl chloride resin, the measurement results of the number of fish eyes, and the confirmation results of the scale adhesion status in Reference Example 9.

[0287] (Reference Examples 10 - 11) A vinyl chloride polymer was synthesized using a polymerization apparatus similar to the polymerization apparatus 100 shown in FIG. 2, except that it did not have the serpentine cooling pipe 140. In Reference Examples 10 - 11, a vinyl chloride polymer was synthesized by the same procedure as in Reference Example 1, except that the dimensions of the reaction vessel 110, the presence or absence of the serpentine cooling pipe 140, the rotational speed of the stirring shaft 122, and the charged amount of the raw materials were different. In Reference Examples 10 - 11, the stoichiometric ratio and reaction temperature of each raw material were adjusted in the same manner as in Reference Example 1. Thereby, the influence of the structures arranged inside the reaction vessel can be considered.

[0288] Table 2 shows an overview of the specifications of the polymerization apparatuses of Reference Examples 10 - 11. Table 2 also shows the measurement results of the particle size distribution of the vinyl chloride resin, the measurement results of the number of fish eyes, and the confirmation results of the scale adhesion status in Reference Examples 10 - 11.

[0289] (Reference Example 12) A vinyl chloride polymer was synthesized using a polymerization apparatus similar to the polymerization apparatus 100 shown in FIG. 2, except that the number of series of the serpentine cooling pipes in the radial direction of the reaction vessel 110 was tripled. In Reference Examples 10 - 11, a vinyl chloride polymer was synthesized by the same procedure as in Reference Example 1, except that the dimensions of the reaction vessel 110, the number of series of the serpentine cooling pipes, the rotational speed of the stirring shaft 122, and the charged amount of the raw materials were different. In Reference Example 12, the stoichiometric ratio and reaction temperature of each raw material were adjusted in the same manner as in Reference Example 1. Thereby, the influence of the structures arranged inside the reaction vessel can be considered.

[0290] Table 2 shows an overview of the specifications of the polymerization apparatus of Reference Example 12. Table 2 also shows the measurement results of the particle size distribution of the vinyl chloride resin, the measurement results of the number of fish eyes, and the confirmation results of the scale adhesion status in Reference Example 12.

[0291] (Reference Example 13) A vinyl chloride polymer was synthesized using a polymerization apparatus similar to the polymerization apparatus 100 shown in Fig. 2, except that the number of rows of the serpentine cooling pipes in the radial direction of the reaction vessel 110 was five. In Reference Example 13, a vinyl chloride polymer was synthesized by the same procedure as in Reference Example 1, except that the dimensions of the reaction vessel 110, the number of rows of the serpentine cooling pipes, the rotational speed of the stirring shaft 122, and the charged amount of the raw materials were different. In Reference Example 13, the stoichiometric ratio and reaction temperature of each raw material were adjusted in the same manner as in Reference Example 1. Thus, the influence of the structure arranged inside the reaction vessel can be considered.

[0292] Table 2 shows an outline of the specifications of the polymerization apparatus of Reference Example 13. Table 2 also shows the measurement results of the particle size distribution of the vinyl chloride resin, the measurement results of the number of fish eyes, and the confirmation results of the scale adhesion state in Reference Example 13.

[0293] (Reference Comparative Example 1) A vinyl chloride polymer was synthesized using a polymerization apparatus similar to the polymerization apparatus 100 used in Reference Example 1, except that the dimensions of the reaction vessel 110 were different. In Reference Comparative Example 1, a vinyl chloride polymer was synthesized by the same procedure as in Reference Example 1, except that the dimensions of the reaction vessel 110, the dimensions of the stirring blade 124, and the rotational speed of the stirring shaft 122 were different. In Reference Comparative Example 1, the stoichiometric ratio and reaction temperature of each raw material were adjusted in the same manner as in Reference Example 1.

[0294] In Reference Comparative Example 1 and Reference Example 1, the L / D of the reaction vessel 110 is different. Therefore, in Reference Comparative Example 1 and Reference Example 1, the flow states inside the reaction vessel 110 are different. As a result, in Reference Comparative Example 1 and Reference Example 1, the stirring conditions under which polymerization can be continued are also different. Therefore, by adjusting the value of b / d and the set value of the rotational speed of the stirring shaft in Equation 1, the stirring conditions in Reference Comparative Example 1 were determined. As a result, the value of b / d in Reference Comparative Example 1 was larger than the value of b / d in Reference Example 1. Also, the value of the stirring parameter in Reference Comparative Example 1 was 6.44.

[0295] Table 3 shows an overview of the specifications of the polymerization apparatus of Reference Comparative Example 1. Table 3 also shows the measurement results of the particle size distribution of the vinyl chloride resin, the measurement results of the number of fish eyes, and the confirmation results of the scale adhesion status in Reference Comparative Example 1.

[0296] (Reference Comparative Examples 2 to 5) A vinyl chloride polymer was synthesized using the same polymerization apparatus as that used in Reference Example 1, except that the dimensions of the reaction vessel 110 and the arrangement and pitch width of the serpentine cooling pipe were different. In Reference Comparative Examples 2 to 5, a vinyl chloride polymer was synthesized by the same procedure as in Reference Example 1, except that the dimensions of the reaction vessel 110, the arrangement and pitch width of the serpentine cooling pipe, the dimensions of the stirring blade 124, the rotational speed of the stirring shaft 122, and the charged amount of the raw materials were different. In Reference Comparative Examples 2 to 5, the stoichiometric ratio and reaction temperature of each raw material were adjusted in the same manner as in Reference Example 1. In Reference Comparative Examples 2 to 5, the rotational speed of the stirring shaft 122 was determined such that the value of the stirring parameter exceeded 6.

[0297] Table 3 shows an overview of the specifications of the polymerization apparatus of Reference Comparative Examples 2 to 5. Table 3 also shows the measurement results of the particle size distribution of the vinyl chloride resin, the measurement results of the number of fish eyes, and the confirmation results of the scale adhesion status in Reference Comparative Examples 2 to 5.

[0298] As shown by the results of Reference Examples 1 to 13, by determining the dimensions of the straight body portion of the reaction vessel 110, the dimensions of at least one of the plurality of stirring blades 124, and the set value of the rotational speed of the stirring shaft 122 such that the value of the stirring parameter is 6.0 or less, the generation of coarse particles can be suppressed, and a vinyl chloride resin having a good particle size distribution can be synthesized. It can also be seen that the generation of fish eyes is greatly suppressed. Furthermore, the generation of scale can hardly be confirmed visually.

[0299] On the other hand, as shown by Reference Comparative Examples 1 to 5, when the value of the stirring parameter exceeds 6.0, coarse particles are generated, and a vinyl chloride resin having a relatively wide particle size distribution is synthesized. Also, a large number of fish eyes are generated, and scale that can be easily confirmed visually is generated.

[0300] Although the cause of the above phenomenon is not clear, for example, the following causes are presumed. That is, the flow state inside the reaction vessel 110 is affected by the L / D of the reaction vessel 110, the structure and arrangement of the internal structures arranged inside the reaction vessel 110, and the like. For example, when the L / D of the reaction vessel 110 increases, in order to ensure the fluidity of the fluid inside the reaction vessel 110, it is necessary to increase b. On the other hand, when b increases, in order to maintain the magnitude of the stirring energy added to the raw material at about 80 to 200 kgf·m / s·m 3 it may be necessary to decrease the set value n of the rotational speed. At this time, if the relationship represented by Equation 1 or the like does not hold, the fluidity of the fluid inside the reaction vessel 110 becomes insufficient, and it is considered that problems may occur in the polymerization.

[0301] For the same reason, when the influence of the internal structure arranged inside the reaction vessel 110 on the flow state increases, it becomes difficult to control the stirring state. For example, when the number of series of the serpentine cooling pipes is 2 or more, it becomes difficult to control the stirring state. Even in such a case, as shown in Reference Examples 3 to 7, by determining the dimension of the straight body part of the reaction vessel 110, the dimension of at least one of the plurality of stirring blades 124, and the set value of the rotational speed of the stirring shaft 122 so that the value of the stirring parameter becomes 0.3 to 5.5, it can be seen that high-quality vinyl chloride resin can be synthesized even when the number of series of the serpentine cooling pipes is 2 or more. In particular, it can be seen that a great effect is obtained in suppressing the generation of fish eyes.

[0302]

Table 1

[0303]

Table 2

[0304]

Table 3

[0305] (Examples and Comparative Examples) As examples, polymerization examples are shown where the number Nc [pieces] of the above virtual circles is 1, 2, or 3, and the number Nc [pieces] of the above virtual circles and the ratio CZ [mg - dispersing aid / kg - monomer] of the mass of the dispersing aid to the mass of the raw material solution satisfy the relationship shown in the above formula A1. Further, as comparative examples, polymerization examples are shown where the number Nc of the above virtual circles is 1, 2, or 3, and the number Nc of the above virtual circles and the above ratio CZ do not satisfy the relationship shown in the above formula A1.

[0306] In the examples and comparative examples, the physical properties of the resin particles and the amount of scale adhering to the inside of the reaction apparatus are evaluated using the ratio of the mass of the dispersing aid to the mass of the monomer as an index. Therefore, in the description of the examples and comparative examples, the description of the specific numerical values of the mass of the monomer and the mass of the dispersing aid is omitted. However, those skilled in the art who are familiar with the description of the present application can manufacture and use the polymerization apparatus according to the present embodiment without excessive trial and error based on the description of the examples and comparative examples. The dispersing aid and the buffering agent may sometimes be simply referred to as auxiliary agents.

[0307] (Examples 1 to 3) A vinyl chloride polymer was synthesized using a polymerization apparatus configured in the same manner as the polymerization apparatus used in Reference Example 6 except that the "arrangement of the cooling pipes" was "single - layer arrangement". In the above polymerization apparatus, four meandering cooling pipes arranged in a single layer in the radial direction were arranged inside the reaction vessel 110.

[0308] In Examples 1 to 3, vinyl chloride polymers were produced by changing the addition amount of the dispersing aid. In Example 1, a vinyl chloride polymer was synthesized by the same procedure as in Reference Example 6 except that the composition and addition amount of the dispersing aid were different and commercially available citric acid was added as a buffering agent. In Examples 2 to 3, vinyl chloride polymers were synthesized by the same procedure as in Reference Example 6 except that the composition and addition amount of the dispersing aid were different.

[0309] In Examples 1 to 3, the polymerization temperature and the supply temperature of the refrigerant were the same. Further, the above polymerization temperature was set based on the target value of the K value of the polymer. The target value of the K value of the polymer was determined based on the average degree of polymerization of the target polymer. As the dispersion aid, a mixture of partially saponified polyvinyl alcohol (PVA) and hydroxypropyl methylcellulose (HPMC) was used. Table 4 shows the composition and addition amount of the dispersion aid and the addition amount of the buffer in Examples 1 to 3.

[0310] (Comparative Examples 1 to 2) Using the same polymerization apparatus as that used in Example 1, a vinyl chloride polymer was synthesized. In Comparative Example 1, a vinyl chloride polymer was synthesized by the same procedure as in Example 1, except that the addition amounts of the respective dispersion aids were different and no buffer was added. In Comparative Example 2, a vinyl chloride polymer was synthesized by the same procedure as in Example 3, except that the addition amounts of the respective dispersion aids were different and commercially available citric acid was added as the buffer. Table 4 shows the composition and addition amount of the dispersion aid and the addition amount of the buffer in Comparative Examples 1 to 2.

[0311] [Table 4]

[0312] In Table 4, "〇" indicates that the auxiliary agent is added, and "-" indicates that the auxiliary agent is not added. In Example 1, Example 2, and Comparative Example 1, the composition of the partially saponified PVA was the same. In Example 3 and Comparative Example 2, the composition of the partially saponified PVA was the same.

[0313] (Examples 4 to 6) Using a polymerization apparatus configured in the same manner as the polymerization apparatus used in Reference Example 6, a vinyl chloride polymer was synthesized. In the above polymerization apparatus, as shown in FIG. 2, eight meandering cooling pipes arranged in a double layer in the radial direction were arranged inside the reaction vessel 110.

[0314] In Examples 4 to 6, vinyl chloride polymers were produced by changing the addition amount of the dispersion aid. In Examples 4 and 6, vinyl chloride polymers were synthesized by the same procedure as in Reference Example 6, except that the composition and addition amount of the dispersion aid were different, and commercially available citric acid was added as a buffer. In Example 5, a vinyl chloride polymer was synthesized by the same procedure as in Reference Example 6, except that the composition and addition amount of the dispersion aid were different.

[0315] In Examples 4 to 6, the polymerization temperature and the supply temperature of the refrigerant were the same as those in Example 1. As described above, the polymerization temperature was set based on the target value of the K value of the polymer. The composition and addition amount of the dispersion aid and the addition amount of the buffer in Examples 4 to 6 are shown in Table 5.

[0316] (Comparative Examples 3 to 4) Using the same polymerization apparatus as that used in Example 4, vinyl chloride polymers were synthesized. In Comparative Example 3, a vinyl chloride polymer was synthesized by the same procedure as in Example 4, except that the addition amounts of the respective aids were different. In Comparative Example 4, a vinyl chloride polymer was synthesized by the same procedure as in Example 6, except that the addition amounts of the respective dispersion aids were different and no buffer was added. The composition and addition amount of the dispersion aid and the addition amount of the buffer in Comparative Examples 3 to 4 are shown in Table 5.

[0317]

Table 5

[0318] In Table 5, "〇" indicates that the aid is added, and "-" indicates that the aid is not added. In Example 4, Example 5, and Comparative Example 3, the composition of the partially saponified PVA was the same. In Example 6 and Comparative Example 4, the composition of the partially saponified PVA was the same.

[0319] (Examples 7 to 9) A vinyl chloride polymer was synthesized using a polymerization apparatus configured in the same manner as the polymerization apparatus used in Reference Example 6, except that the "arrangement of cooling pipes" was "triple arrangement". In the above polymerization apparatus, 12 meandering cooling pipes arranged in a triple layer in the radial direction were arranged inside the reaction vessel 110.

[0320] In Examples 7 to 9, vinyl chloride polymers were produced by changing the addition amount of the dispersion aid. In Example 7, a vinyl chloride polymer was synthesized by the same procedure as in Reference Example 6, except that the composition and addition amount of the dispersion aid were different. In Examples 8 to 9, a vinyl chloride polymer was synthesized by the same procedure as in Reference Example 6, except that the composition and addition amount of the dispersion aid were different and a commercially available citric acid was added as a buffer.

[0321] In Examples 7 to 9, the polymerization temperature and the supply temperature of the refrigerant were the same as those in Example 1. As described above, the above polymerization temperature was set based on the target value of the K value of the polymer. The composition and addition amount of the dispersion aid and the addition amount of the buffer in Examples 7 to 9 are shown in Table 6.

[0322] (Comparative Examples 5 to 6) A vinyl chloride polymer was synthesized using the same polymerization apparatus as that used in Example 7. In Comparative Example 5, a vinyl chloride polymer was synthesized by the same procedure as in Example 7, except that the addition amount of the partially saponified PVA was different. In Comparative Example 6, a vinyl chloride polymer was synthesized by the same procedure as in Example 9, except that the addition amount of each auxiliary agent was different. The composition and addition amount of the dispersion aid and the addition amount of the buffer in Comparative Examples 5 to 6 are shown in Table 6.

[0323]

Table 6

[0324] In Table 6, “〇” indicates that the auxiliary agent is added, and “-” indicates that the auxiliary agent is not added. In Example 7, Example 8, and Comparative Example 5, the composition of the partially saponified PVA was the same. In Example 9 and Comparative Example 6, the composition of the partially saponified PVA was the same.

[0325] (Evaluation) (Evaluation of resin particles) In each of Examples 1 to 9 and Comparative Examples 1 to 6, the apparent density, particle size distribution, number of fish eyes, and loss on drying of the produced polymer (which may be referred to as resin particles) were measured. The apparent density of the resin particles was measured in accordance with JIS K7365. As the particle size distribution of the polymer, the mass percentage of resin particles passing through a 60-mesh sieve, the mass percentage of resin particles passing through a 100-mesh sieve, and the mass percentage of resin particles passing through a 200-mesh sieve were measured.

[0326] The number of fish eyes was measured according to the following procedure. First, 100 parts by mass of the sample polymer, 50 parts by mass of bis(2-ethylhexyl) phthalate (DOP), 2.0 parts by mass of a Ba / Zn-based stabilizer, 5.0 parts by mass of epoxidized soybean oil, 0.1 part by mass of carbon black, and 0.5 part by mass of titanium dioxide were mixed to obtain a compound. Next, 50 g of the above compound was kneaded with a roll mill at 145 °C for 6 minutes and separated as a sheet with a thickness of 0.3 mm. Then, the number of transparent particles in 100 cm 2 of the above sheet was visually measured to measure the number of fish eyes.

[0327] The loss on drying was measured in accordance with the test method specified in the 18th Revised Japanese Pharmacopoeia (Ministry of Health, Labour and Welfare Notification No. 220 of June 7, 2021). Specifically, 1 g of the resin particles was weighed and dried at 105 °C for 4 hours. The dried resin particles were placed in a desiccator using silica gel and allowed to cool to room temperature. The mass of the resin particles after cooling was measured, and the ratio of the weight loss due to drying to the mass of the resin particles before drying was calculated.

[0328] (Evaluation regarding scale) Also, in each of Examples 1 to 9 and Comparative Examples 1 to 6, after the polymerization test was completed, the surface of the inner wall of the reaction vessel was visually observed to confirm the presence or absence of scale adhesion.

[0329] The evaluation results for Examples 1 to 3 and Comparative Examples 1 to 2 are shown in Table 7. The evaluation results for Examples 4 to 6 and Comparative Examples 3 to 4 are shown in Table 8. The evaluation results for Examples 7 to 9 and Comparative Examples 5 to 6 are shown in Table 9.

[0330]

Table 7

[0331]

Table 8

[0332]

Table 9

[0333] In Tables 7 to 9, "A" for the scale adhesion situation indicates that almost no scale was visually confirmed. "B" indicates that a small amount of scale (more scale than in the case of "A") was visually confirmed. "C" indicates that a large amount of scale was visually confirmed.

[0334] In Examples 1 to 9, the above ratio CZ is within the numerical range indicated by Formula A1, and in Comparative Examples 1 to 6, the above ratio CZ is outside the numerical range indicated by Formula A1. As shown in Tables 7 to 9, in Examples 1 to 9, the particle size distribution was narrower and resin particles with fewer fish eyes were produced compared to Comparative Examples 1 to 6. It can be seen that in Examples 1 to 9, the drying loss of the resin particles was smaller and the mixing of the raw material solution was less compared to Comparative Examples 1 to 6. In particular, in Examples 1 to 9, resin particles with a drying loss of 1% or less were obtained. Also, in Examples 1 to 9, the adhesion of scale was suppressed compared to Comparative Examples 1 to 6.

[0335] In Example 1 and Example 2, the above ratio CZ is within the numerical range shown by Formula B1, and in Example 3, the above ratio CZ is outside the numerical range shown by Formula B1. As shown in Table 7, in Example 1 and Example 2, the adhesion of scale was significantly suppressed. In Example 1 and Example 2, the adhesion of scale was also suppressed as compared with Example 3. Similarly, as shown in Table 8, in Example 4 and Example 5, the adhesion of scale was suppressed as compared with Example 6. Also, as shown in Table 9, in Example 7 and Example 8, the adhesion of scale was suppressed as compared with Example 9.

[0336] In Example 2 and Example 3, the above ratio CZ is within the numerical range shown by Formula C1, and in Example 1, the above ratio CZ is outside the numerical range shown by Formula C1. As shown in Table 7, in Example 2 and Example 3, resin particles with very few fish eyes were produced. In Example 2 and Example 3, resin particles with fewer fish eyes were produced as compared with Example 1. Similarly, as shown in Table 8, in Example 5 and Example 6, resin particles with fewer fish eyes were produced as compared with Example 4. Also, as shown in Table 9, in Example 8 and Example 9, resin particles with fewer fish eyes were produced as compared with Example 7.

[0337] In Example 2, the above ratio CZ is within the numerical range shown by Formula D1, and in Example 1 and Example 3, the above ratio CZ is outside the numerical range shown by Formula D1. As shown in Table 7, in Example 2, resin particles with very few fish eyes were produced, and the adhesion of scale was significantly suppressed. Similarly, as shown in Table 8, in Example 5, resin particles with very few fish eyes were produced, and the adhesion of scale was significantly suppressed. Also, as shown in Table 9, in Example 8, resin particles with very few fish eyes were produced, and the adhesion of scale was significantly suppressed.

[0338] As described above, the present invention has been described using embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. It is obvious to those skilled in the art that various changes or improvements can be made to the above embodiments. It is clear from the description of the claims that forms with such changes or improvements can also be included in the technical scope of the present invention.

[0339] In the claims, the description, and the drawings, the execution order of each process such as operations, procedures, steps, and stages in the apparatus, system, program, and method shown should be noted. Unless specifically stated as "before" or "preceding," and unless the output of the previous process is used in the subsequent process, it can be realized in any order. Regarding the operation flow in the claims, the description, and the drawings, even if it is described for convenience using "first," "next," etc., it does not mean that it is essential to be implemented in this order.

[0340] [Conceivable Embodiments] [Item 1] A batch reactor used for producing a polymer by suspension polymerization using a dispersion aid, a reactor having a cylindrical straight body portion, a plurality of first cooling pipes arranged inside the reactor for circulating a refrigerant, a stirring shaft arranged inside the reactor, to which a stirring blade is attached and which is configured to be rotatable, comprising, each representative point of the plurality of first cooling pipes in a plane substantially perpendicular to the extending direction of the straight body portion is located on the circumference of any of a plurality of virtual circles arranged substantially concentrically in the substantially perpendicular plane, when the number Nc [pieces] of the plurality of virtual circles is 1, 2, or 3, the number Nc [pieces] of the plurality of virtual circles and the ratio CZ [mg - dispersion aid / kg - monomer] of the mass of the dispersion aid to the mass of one or more types of monomers as raw materials of the polymer satisfy the relationship shown in the following mathematical formula A1, (Mathematical formula A1) 15Nc + 300 < CZ < 175Nc + 2000 Reactor [Item 2] When the number Nc of the plurality of virtual circles is 4 or more, the ratio CZ [mg - dispersion aid / kg - monomer] satisfies the relationship shown in the following mathematical formula A2: (Mathematical formula A2) 15×3 + 300 < CZ < 175×3 + 2000 The reactor according to Item 1 [Item 3] When the number Nc [pieces] of the plurality of virtual circles is 1, 2, or 3, the number Nc [pieces] and the ratio CZ [mg - dispersion aid / kg - monomer] satisfy the relationship shown in the following mathematical formula B1: (Mathematical formula B1) 15Nc + 310 < CZ < 175Nc + 1550 The reactor according to Item 1 [Item 4] When the number Nc [pieces] of the plurality of virtual circles is 1, 2, or 3, the number Nc [pieces] and the ratio CZ [mg - dispersion aid / kg - monomer] satisfy the relationship shown in the following mathematical formula C1: (Mathematical formula C1) 15Nc + 400 < CZ < 175Nc + 1850 The reactor according to Item 1 [Item 5] When the number Nc [pieces] of the plurality of virtual circles is 1, 2, or 3, the number Nc [pieces] and the ratio CZ [mg - dispersion aid / kg - monomer] satisfy the relationship shown in the following mathematical formula D1: (Mathematical formula D1) 15Nc + 400 < CZ < 175Nc + 1550 The reactor according to Item 1 [Item 6] Further comprising a dispersion aid input section for inputting the dispersion aid into the reactor, when the number Nc [pieces] of the plurality of virtual circles is 1, 2, or 3, the dispersion aid input section inputs the dispersion aid so that the number Nc [pieces] and the ratio CZ [mg - dispersion aid / kg - monomer] satisfy the relationship shown in the above mathematical formula A1. The reactor according to item 1. [Item 7] A batch reactor used for producing a polymer by suspension polymerization using a dispersion aid, a reactor having a cylindrical straight body portion, a plurality of first cooling pipes arranged inside the reactor for circulating a refrigerant, a stirring shaft arranged inside the reactor, to which one or more stirring blades are attached and which is configured to be rotatable, a dispersion aid input section for introducing the dispersion aid into the reactor, and comprising: Each representative point of the plurality of first cooling pipes in a plane substantially perpendicular to the extending direction of the straight body portion is located on the circumference of any one of a plurality of virtual circles arranged substantially concentrically in the substantially perpendicular plane, When the number Nc [pieces] of the plurality of virtual circles is 1, 2, or 3, the dispersion aid input section inputs the dispersion aid so that the number Nc [pieces] of the plurality of virtual circles and the ratio CZ [mg - dispersion aid / kg - monomer] of the mass of the dispersion aid to the mass of one or more types of monomers that are raw materials of the polymer satisfy the relationship shown in the following mathematical formula A1. (Mathematical formula A1) 15Nc + 300 < CZ < 175Nc + 2000 Reactor. [Item 8] The stirring shaft is configured such that a plurality of the stirring blades can be attached at different positions in the extending direction of the stirring shaft, The dimensions of the straight body portion, the dimensions of at least one of the plurality of stirring blades, and the set value of the rotation speed of the stirring shaft satisfy the relationship shown in the following mathematical formula 1. (Mathematical formula 1) N(b / d)(L / D) / n ≦ 6.0 (In mathematical formula 1, N represents the number of the plurality of stirring blades, b represents the maximum value [m] of the blade width of the plurality of stirring blades, d represents the maximum value [m] of the blade diameter of the plurality of stirring blades, L represents the length [m] in the extending direction of the straight body portion D represents the maximum value [m] of the diameters of a plurality of inscribed circles that are substantially inscribed in the straight cylindrical portion in each of the cross-sections formed by a plurality of planes that are planes substantially perpendicular to the extending direction of the straight cylindrical portion and pass through the attachment positions of the respective stirring blades. When the straight cylindrical portion is cut by the plurality of planes, n represents the set value of the rotational speed [rps] of the stirring shaft.) The reactor according to item 1 or item 7. [Item 9] Each of the plurality of first cooling pipes has a meandering portion that extends while repeatedly bending. The meandering portion includes a plurality of extending portions that extend linearly or extend in a curved manner, and a plurality of bending portions that connect the ends of two adjacent extending portions among the plurality of extending portions. and The reactor according to item 1 or item 7. [Item 10] Each of the plurality of first cooling pipes includes a plurality of ring portions having a ring shape, and one or more connecting portions that connect the plurality of ring portions. and The reactor according to item 1 or item 7. [Item 11] a plurality of baffles that extend substantially parallel to the extending direction of the straight cylindrical portion, and a second cooling pipe disposed inside at least one of the plurality of baffles for circulating a refrigerant. and further includes The reactor according to item 1 or item 7. [Item 12] A method for producing a vinyl-based polymer, comprising a step of polymerizing a vinyl-based monomer using the reactor according to item 1 or item 7 to produce a vinyl-based polymer. A method for producing a vinyl-based polymer. [Item 13] A method for producing a vinyl-based polymer by suspension polymerization using a batch reactor, wherein the reactor is a reactor having a cylindrical straight cylindrical portion. A plurality of first cooling pipes arranged inside the reactor for circulating a refrigerant, and A stirring shaft arranged inside the reactor, to which stirring blades are attached and which is configured to be rotatable, comprising Each representative point of the plurality of first cooling pipes on a plane substantially perpendicular to the extending direction of the straight body portion is located on the circumference of any of a plurality of virtual circles substantially concentrically arranged on the substantially perpendicular plane, The method is A raw material input step of introducing a vinyl monomer, an aqueous medium, and a dispersion aid into the reactor, and A polymerization step of polymerizing the vinyl monomer to produce a vinyl polymer, having The raw material input step is When the number Nc [pieces] of the plurality of virtual circles is 1, 2, or 3, the number Nc [pieces] of the plurality of virtual circles and the ratio CZ [mg - dispersion aid / kg - monomer] of the mass of the dispersion aid to the mass of the vinyl monomer satisfy the relationship shown in the following mathematical formula A1, the step of introducing the dispersion aid, including (Mathematical formula A1) 15Nc + 300 < CZ < 175Nc + 2000 Method.

[0341] [Other conceivable embodiments] [Item 1] A batch reactor used for producing a polymer by suspension polymerization using a dispersion aid, A reactor having a cylindrical straight body portion, and A plurality of first cooling pipes arranged inside the reactor for circulating a refrigerant, and A stirring shaft arranged inside the reactor, to which stirring blades are attached and which is configured to be rotatable, comprising The plurality of first cooling pipes on a plane substantially perpendicular to the extending direction of the straight body portion are arranged on the arcs of one or a plurality of concentric circles having a center on the central axis of the stirring shaft, When the number Nc [pieces] of the concentric circles is 1, 2, or 3, the number Nc [pieces] of the concentric circles and the ratio CZ [mg - dispersing aid / kg - monomer] of the mass of the dispersing aid to the mass of one or more types of monomers that are raw materials of the polymer satisfy the relationship shown in the following mathematical formula A1: (Mathematical formula A1) 15Nc + 300 < CZ < 175Nc + 2000 The stirring shaft is configured such that a plurality of the stirring blades can be attached at different positions in the extending direction of the stirring shaft. The dimensions of the straight barrel portion, the dimensions of at least one of the plurality of stirring blades, and the set value of the rotational speed of the stirring shaft satisfy the relationship shown in the following mathematical formula 1. (Mathematical formula 1) N(b / d)(L / D) / n ≦ 6.0 (In Mathematical formula 1, N represents the number of the plurality of stirring blades. b represents the maximum value [m] of the blade widths of the plurality of stirring blades. d represents the maximum value [m] of the blade diameters of the plurality of stirring blades. L represents the length [m] of the straight barrel portion in the extending direction. D represents the maximum value [m] of the diameters of a plurality of inscribed circles that are substantially inscribed in the straight barrel portion in each of the cross - sections formed by a plurality of planes that are planes substantially perpendicular to the extending direction of the straight barrel portion and pass through the respective attachment positions of the plurality of stirring blades when the straight barrel portion is cut by the plurality of planes. n represents the set value of the rotational speed [rps] of the stirring shaft.) Reactor. [Item 2] When the number Nc of the concentric circles is 4 or more, the ratio CZ [mg - dispersing aid / kg - monomer] satisfies the relationship shown in the following mathematical formula A2. (Mathematical formula A2) 15×3 + 300 < CZ < 175×3 + 2000 The reactor according to Item 1. [Item 3] When the number Nc [pieces] of the concentric circles is 1, 2, or 3, The number Nc [pieces] and the ratio CZ [mg - dispersion aid / kg - monomer] satisfy the relationship shown in the following mathematical formula B1. (Mathematical formula B1) 15Nc + 310 < CZ < 175Nc + 1550 The reactor according to Item 1. [Item 4] When the number Nc [pieces] of the concentric circles is 1, 2, or 3, The number Nc [pieces] and the ratio CZ [mg - dispersion aid / kg - monomer] satisfy the relationship shown in the following mathematical formula C1. (Mathematical formula C1) 15Nc + 400 < CZ < 175Nc + 1850 The reactor according to Item 1. [Item 5] When the number Nc [pieces] of the concentric circles is 1, 2, or 3, The number Nc [pieces] and the ratio CZ [mg - dispersion aid / kg - monomer] satisfy the relationship shown in the following mathematical formula D1. (Mathematical formula D1) 15Nc + 400 < CZ < 175Nc + 1550 The reactor according to Item 1. [Item 6] It further includes a dispersion - aid input section for inputting the dispersion aid into the reactor. When the number Nc [pieces] of the concentric circles is 1, 2, or 3, the dispersion - aid input section inputs the dispersion aid so that the number Nc [pieces] and the ratio CZ [mg - dispersion aid / kg - monomer] satisfy the relationship shown in the above - mentioned mathematical formula A1. The reactor according to Item 1. [Item 7] A batch - type reactor used for producing a polymer by suspension polymerization using a dispersion aid, A reactor having a cylindrical straight - body part, A plurality of first cooling pipes arranged inside the reactor for circulating a refrigerant, A stirring shaft arranged inside the reactor, to which one or more stirring blades are attached and which is configured to be rotatable, A dispersion - aid input section for inputting the dispersion aid into the reactor comprising The plurality of first cooling pipes in a plane substantially perpendicular to the extending direction of the straight cylindrical portion are arranged on one or a plurality of concentric circular arcs having a center on the central axis of the stirring shaft. When the number Nc [pieces] of the concentric circles is 1, 2, or 3, the dispersion aid input section inputs the dispersion aid so that the number Nc [pieces] of the concentric circles and the ratio CZ [mg-dispersion aid / kg-monomer] of the mass of the dispersion aid to the mass of one or more types of monomers that are raw materials of the polymer satisfy the relationship shown in the following mathematical formula A1. (Mathematical formula A1) 15Nc + 300 < CZ < 175Nc + 2000 The stirring shaft is configured such that a plurality of the stirring blades can be attached at different positions in the extending direction of the stirring shaft. The dimensions of the straight cylindrical portion, the dimensions of at least one of the plurality of stirring blades, and the set value of the rotational speed of the stirring shaft satisfy the relationship shown in the following mathematical formula 1. (Mathematical formula 1) N(b / d)(L / D) / n ≦ 6.0 (In Mathematical formula 1, N represents the number of the plurality of stirring blades. b represents the maximum value [m] of the blade widths of the plurality of stirring blades. d represents the maximum value [m] of the blade diameters of the plurality of stirring blades. L represents the length [m] of the straight cylindrical portion in the extending direction. D represents the maximum value [m] of the diameters of a plurality of inscribed circles that are substantially inscribed in the straight cylindrical portion in each of the cross-sections formed by a plurality of planes that are planes substantially perpendicular to the extending direction of the straight cylindrical portion and pass through the respective attachment positions of the plurality of stirring blades when the straight cylindrical portion is cut by the plurality of planes. n represents the set value of the rotational speed [rps] of the stirring shaft.) Reactor. [Item 8] Each of the plurality of first cooling pipes has a meandering portion that extends while repeatedly bending. The meandering portion a plurality of extending portions that extend linearly or extend in a curved manner, and Among the plurality of extended portions, a plurality of bending portions that connect the ends of two adjacent extended portions including the reactor according to Item 1 or Item 7. [Item 9] Each of the plurality of first cooling pipes has a plurality of ring portions having a ring shape, and one or more connecting portions that connect the plurality of ring portions, including the reactor according to Item 1 or Item 7. [Item 10] a plurality of baffles extending substantially parallel to the extending direction of the straight body portion, and a second cooling pipe disposed inside at least one of the plurality of baffles for circulating a refrigerant, further comprising the reactor according to Item 1 or Item 7. [Item 11] A method for producing a vinyl polymer, comprising the step of polymerizing a vinyl monomer using the reactor according to Item 1 or Item 7 to produce a vinyl polymer. A method for producing a vinyl polymer. [Item 12] A method for producing a vinyl polymer by suspension polymerization using a batch reactor, wherein the reactor has a reactor having a cylindrical straight body portion, a plurality of first cooling pipes disposed inside the reactor for circulating a refrigerant, a stirring shaft disposed inside the reactor, to which a stirring blade is attached and which is configured to be rotatable, comprising the plurality of first cooling pipes in a plane substantially perpendicular to the extending direction of the straight body portion are disposed on one or more concentric circular arcs having a center on the central axis of the stirring shaft, the method comprising a raw material charging step of charging a vinyl monomer, an aqueous medium, and a dispersion aid into the reactor, a polymerization step of polymerizing the vinyl monomer to produce a vinyl polymer, having The raw material input stage is When the number Nc [pieces] of the concentric circles is 1, 2, or 3, the number Nc [pieces] of the concentric circles and the ratio CZ [mg - dispersing aid / kg - monomer] of the mass of the dispersing aid to the mass of the vinyl monomer satisfy the relationship shown in the following mathematical formula A1, and the step of adding the dispersing aid including (Mathematical formula A1) 15Nc + 300 < CZ < 175Nc + 2000 The stirring shaft is configured such that a plurality of the stirring blades can be attached at different positions in the extending direction of the stirring shaft. The dimension of the straight barrel part, the dimension of at least one of the plurality of stirring blades, and the set value of the rotation speed of the stirring shaft satisfy the relationship shown in the following mathematical formula 1. (Mathematical formula 1) N(b / d)(L / D) / n ≦ 6.0 (In mathematical formula 1, N represents the number of the plurality of stirring blades. b represents the maximum value [m] of the blade width of the plurality of stirring blades. d represents the maximum value [m] of the blade diameter of the plurality of stirring blades. L represents the length [m] of the straight barrel part in the extending direction. D represents the maximum value [m] of the diameters of a plurality of inscribed circles that are substantially inscribed in the straight barrel part in each of the cross - sections formed by a plurality of planes that are planes substantially perpendicular to the extending direction of the straight barrel part and pass through the respective attachment positions of the plurality of stirring blades when the straight barrel part is cut by the plurality of planes. n represents the set value of the rotation speed [rps] of the stirring shaft.) Method.

Explanation of symbols

[0342] 100 Polymerization apparatus, 110 Reaction vessel, 120 Agitator, 122 Agitation shaft, 124 Agitation blade, 126 Power mechanism, 130 Baffle, 132 Body, 134 Support, 140 Serpentine cooling tube, 150 Serpentine cooling tube, 170 Jacket, 172 Flow path, 180 Reflux condenser, 182 Flow path, 232 Baffle, 234 Baffle, 236 Baffle, 238 Baffle, 242 Serpentine cooling tube, 244 Serpentine cooling tube, 246 Serpentine cooling tube, 248 Serpentine cooling tube, 252 Serpentine cooling tube, 254 Serpentine cooling tube, 256 Serpentine cooling tube, 258 Serpentine cooling tube, 312 Straight body portion, 314 First head plate, 316 Second head plate, 318 Base, 332 Refrigerant supply pipe, 334 Refrigerant return pipe, 342 Connection part, 344 Connection part, 346 Connection part, 510 Inner pipe, 512 Inlet, 520 Outer pipe, 522 Outlet, 532 Pipe, 534 Pipe, 542 Flow rate control valve, 544 Flow rate control valve, 552 Pipe, 554 Flow rate control valve, 556 Pipe, 558 Flow rate control valve, 610 Serpentine part, 612 Extension part, 614 Bend part, 702 Supply pipe, 704 Outlet pipe, 710 Serpentine part, 712 Extension part, 714 Bend part, 810 Serpentine part, 812 Serpentine part, 814 Serpentine part, 816 Serpentine part, 822 Connection part, 824 Connection part, 900 Polymerization device, 1000 Polymerization device, 1100 Polymerization apparatus, 1160, serpentine cooling tube, 1200, polymerization apparatus, 1252, serpentine cooling tube, 1300, polymerization apparatus, 1331, baffle, 1332, baffle, 1333, baffle, 1334, baffle, 1335, baffle, 1336, baffle, 1351, serpentine cooling tube, 1352, serpentine cooling tube, 1353, serpentine cooling tube, 1354, serpentine cooling tube, 1355, serpentine cooling tube, 1356, serpentine cooling tube, 1400, polymerization apparatus, 1403, virtual circle, 1404, virtual circle, 1405, virtual circle, 1500, polymerization apparatus, 1600, polymerization apparatus, 1700, polymerization system, 1702, stirring system, 1710, controller, 1722, stirring blade, 1724, stirring blade, 1726 Agitator blade, 1820 dashed line, 1822 dashed line, 1824 dashed line, 1826 dashed line, 1832 upper end, 1834 lower end, 1842 position, 1844 position, 1852 first position, 1854 second position, 1900 polymerization system, 1910 controller, 1912 agitation control section, 1914 input control section, 1922Monomer storage tank, 1924 aqueous medium storage tank, 1926 dispersion aid storage tank, 1928 polymerization initiator storage tank, 1932 pump, 1934 pump, 1936 pump, 1938 pump, 1942 flowmeter, 1944 flowmeter, 1946 flowmeter, 1948 flowmeter

Claims

1. A batch-type reactor used for producing vinyl chloride polymer by suspension polymerization using a dispersing aid, comprising: A reactor having a cylindrical straight body portion; A plurality of first cooling pipes arranged inside the reactor for circulating a coolant; a stirring shaft disposed inside the reactor, having a stirring blade attached thereto and configured to be rotatable; Equipped with the plurality of first cooling pipes in a plane substantially perpendicular to the extension direction of the straight body portion are arranged on one or more concentric arcs having a center on a central axis of the stirring shaft, When the number Nc of the concentric circles is 1, 2 or 3, the number Nc of the concentric circles and the ratio CZ [mg-dispersing aid / kg-monomer] of the mass of the dispersing aid to the mass of one or more types of monomers that are raw materials for the polymer satisfy the relationship shown in the following formula A1. (Formula A1) 15Nc+300<CZ<175Nc+2000 Reactor.

2. When the number Nc of the multiple concentric circles is 4 or more, the ratio CZ [mg-dispersing agent / kg-monomer] satisfies the relationship shown in the following formula A2: (Formula A2) 15×3+300<CZ<175×3+2000 2. The reactor of claim 1.

3. When the number Nc of the plurality of concentric circles is 1, 2, or 3, The number Nc [pieces] and the ratio CZ [mg-dispersing aid / kg-monomer] satisfy the relationship shown in the following formula B1. (Formula B1) 15Nc+310<CZ<175Nc+1550 2. The reactor of claim 1.

4. When the number Nc of the plurality of concentric circles is 1, 2, or 3, The number Nc [pieces] and the ratio CZ [mg-dispersing aid / kg-monomer] satisfy the relationship shown in the following formula C1. (Formula C1) 15Nc+400<CZ<175Nc+1850 2. The reactor of claim 1.

5. When the number Nc of the plurality of concentric circles is 1, 2, or 3, The number Nc [pieces] and the ratio CZ [mg-dispersing aid / kg-monomer] satisfy the relationship shown in the following formula D1. (Formula D1) 15Nc+400<CZ<175Nc+1550 2. The reactor of claim 1.

6. The reactor further includes a dispersion aid input section for inputting the dispersion aid into the reactor, When the number Nc [pieces] of the concentric circles is 1, 2 or 3, the dispersion aid is added so that the number Nc [pieces] and the ratio CZ [mg-dispersion aid / kg-monomer] satisfy the relationship shown in the above formula A1.

2. The reactor of claim 1.

7. A batch-type reactor used for producing vinyl chloride polymer by suspension polymerization using a dispersing aid, comprising: A reactor having a cylindrical straight body portion; A plurality of first cooling pipes arranged inside the reactor for circulating a coolant; a stirring shaft disposed inside the reactor, having one or more stirring blades attached thereto and configured to be rotatable; A dispersion aid input section for inputting the dispersion aid into the reactor; Equipped with the plurality of first cooling pipes in a plane substantially perpendicular to the extension direction of the straight body portion are arranged on one or more concentric arcs having a center on the central axis of the stirring shaft; When the number Nc [pieces] of the concentric circles is 1, 2 or 3, the dispersion aid input section is such that the number Nc [pieces] of the concentric circles and the ratio CZ [mg-dispersion aid / kg-monomer] of the mass of the dispersion aid to the mass of one or more types of monomers that are raw materials for the polymer satisfy the relationship shown in the following mathematical formula A1. The dispersion aid is input. (Formula A1) 15Nc+300<CZ<175Nc+2000 Reactor.

8. The stirring shaft is configured so that a plurality of the stirring blades can be attached at different positions in the extension direction of the stirring shaft, The dimension of the straight body portion, the dimension of at least one of the plurality of stirring blades, and the set value of the rotation speed of the stirring shaft satisfy the relationship shown in the following formula 1. (Formula 1) N(b / d)(L / D) / n≦6.0 (In Formula 1, N indicates the number of the plurality of stirring blades, b represents the maximum value [m] of the blade width of the plurality of stirring blades, d represents the maximum value [m] of the blade diameter of the plurality of stirring blades, L indicates the length [m] of the straight body portion in the extension direction. D is a plane that is approximately perpendicular to the extension direction of the straight body portion, and when the straight body portion is cut along a plurality of planes that pass through the mounting positions of each of the plurality of stirring blades, the maximum value of the diameters of a plurality of inscribed circles that are approximately inscribed in the straight body portion in each of the cross sections along the plurality of planes [m], n indicates the set value of the rotation speed [rps] of the stirring shaft. The reactor of claim 1 or claim 7.

9. Each of the plurality of first cooling pipes has a meandering portion that extends while repeatedly bending, The meandering portion is A plurality of extension portions extending linearly or curvedly; a plurality of bent portions connecting end portions of two adjacent extension portions among the plurality of extension portions; Including, The reactor of claim 1 or claim 7.

10. Each of the plurality of first cooling pipes is A plurality of ring portions each having a ring shape; One or more connecting portions connecting the plurality of ring portions; Including, The reactor of claim 1 or claim 7.

11. A plurality of baffles extending generally parallel to the extension direction of the straight body portion; a second cooling pipe disposed inside at least one of the plurality of baffles for circulating a coolant; Further comprising: The reactor of claim 1 or claim 7.

12. The method comprises the steps of: polymerizing vinyl chloride monomers using the reactor of claim 1 or claim 7 to produce a vinyl chloride polymer; A method for producing vinyl chloride polymers.

13. A process for producing vinyl chloride polymer by suspension polymerization using a batch reactor, comprising the steps of: The reaction apparatus comprises: A reactor having a cylindrical straight body portion; A plurality of first cooling pipes arranged inside the reactor for circulating a coolant; a stirring shaft disposed inside the reactor, having a stirring blade attached thereto and configured to be rotatable; Equipped with the plurality of first cooling pipes in a plane substantially perpendicular to the extension direction of the straight body portion are arranged on one or more concentric arcs having a center on a central axis of the stirring shaft, The method comprises: A step of introducing a vinyl monomer, an aqueous medium, and a dispersing agent into the reactor; a polymerization step of polymerizing a vinyl monomer to produce a vinyl chloride polymer; having The raw material input step includes: When the number of concentric circles Nc [pieces] is 1, 2 or 3, adding the dispersion aid so that the number of concentric circles Nc [pieces] and the ratio CZ [mg-dispersion aid / kg-monomer] of the mass of the dispersion aid to the mass of the vinyl monomer satisfy the relationship shown in the following mathematical formula A1: Including, (Formula A1) 15Nc+300<CZ<175Nc+2000 method.

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