Residual monomer removal device

Abstract

The present invention relates to a residual monomer removal device, and more particularly, to a residual monomer removal device that can prevent the formation of a dead zone where the distillation target substance does not flow or the flow rate decreases when a gas is supplied to the flowing distillation target substance to remove volatile substances. The residual monomer removal device of the present invention includes: a main body portion capable of supplying a gas to the distillation target substance accommodated therein; a distillation target substance supply portion provided at the upper portion of the main body portion for introducing the distillation target substance; a gas inflow portion provided at the lower portion of the main body portion for introducing the gas; a discharge portion provided at the upper portion of the main body portion for discharging the volatile substances separated from the distillation target substance by the gas; a recovery portion provided at the lower portion of the main body portion for recovering the distillation target substance after removing the volatile substances from the distillation target substance; a plurality of trays provided inside the main body portion, each tray having through holes formed therein and a spiral flow path formed therein; and a downcomer provided between the trays and serving as a moving passage for the distillation target substance to move from the upper portion to the lower portion of the main body portion.

Description

Technical Field

[0001] The present invention relates to a residual monomer removal device, and more particularly, to a residual monomer removal device capable of preventing the formation of a dead zone where the distillation target substance does not flow or the flow rate decreases when supplying a gas to the flowing distillation target substance to remove volatile substances. Background Art

[0002] PVC is generally manufactured by suspension polymerization, emulsion polymerization, or bulk polymerization, but is usually manufactured by suspension polymerization and emulsion polymerization, which have the advantages of easily removing reaction heat and obtaining high-purity products.

[0003] In general, such suspension polymerization and emulsion polymerization involve putting an aqueous medium, a dispersant, and an emulsifier together with vinyl chloride monomer (VCM) and a polymerization initiator into a polymerization vessel equipped with a stirrer, stirring, and maintaining the temperature inside the polymerization vessel to polymerize VCM.

[0004] At this time, the polymerization reaction generally does not continue until all of the VCM is converted to PVC, but ends at a polymerization conversion rate with high production efficiency. After completion, the residual monomer in the polymerization vessel is separated from the PVC slurry by a removal device and then recovered.

[0005] Existing removal devices have proposed various methods to completely remove the VCM formed during such polymerization or to reduce the VCM content to a level harmless to environmental hygiene.

[0006] In particular, the method and device for removing residual monomers of Korean Patent No. 10-0505907 include a perforated plate (tray) provided with a partition plate forming a flow path for the PVC slurry in a sawtooth shape.

[0007] However, in a tray with such a structure, when the PVC slurry flows along the flow path formed by the sawtooth-shaped partition plate, a dead zone where the flow rate of the flowing PVC slurry decreases or it does not flow is formed due to the PVC slurry colliding with the partition plate near the corner. Therefore, the solids of the slurry precipitate and block the holes for supplying gas, so the slurry and the gas may not come into contact, the production efficiency decreases, and the quality of the produced PVC may deteriorate.

[0008] Moreover, since the PVC slurry collides with the partition plate near the corner, a large amount of foam is generated in the PVC slurry. As a result, the gas-liquid contact area between the PVC slurry and the gas decreases, the process efficiency further drops, and the interior of the device may be contaminated. SUMMARY OF THE INVENTION

[0009] An object of the present invention is to relate to a residual monomer removal device that can prevent the formation of a dead zone where the distillation target substance does not flow or the flow rate decreases when removing volatile substances by supplying gas to the flowing distillation target substance.

[0010] The residual monomer removal device according to the present invention may include: a main body portion capable of supplying gas to the distillation target substance accommodated therein; a distillation target substance supply portion provided at an upper portion of the main body portion for introducing the distillation target substance; a gas inlet portion provided at a lower portion of the main body portion for introducing the gas; a discharge portion provided at an upper portion of the main body portion for discharging the volatile substances separated from the distillation target substance by the gas; a recovery portion provided at a lower portion of the main body portion for recovering the distillation target substance after removing the volatile substances from the distillation target substance; a plurality of trays provided inside the main body portion, each tray having a through hole formed therein and a spiral flow path formed thereon; and a downcomer provided between the trays, which is a moving passage for the distillation target substance to move from an upper portion to a lower portion of the main body portion.

[0011] In the residual monomer removal device according to an embodiment of the present invention, the tray may include a disk-shaped body and a spiral baffle. The disk-shaped body is positioned to divide the interior of the main body portion into upper and lower directions. The spiral baffle is located on an upper surface of the body and extends spirally from a central portion of the body portion toward an outer edge direction to form the spiral flow path.

[0012] In the residual monomer removal device according to an embodiment of the present invention, the downcomer may be located at an outer edge of the tray or at the center of the tray and alternate positions along the height direction of the main body portion.

[0013] In the residual monomer removal device according to an embodiment of the present invention, the width of the spiral flow path may be constant.

[0014] In the residual monomer removal device according to an embodiment of the present invention, the supply portion may be formed with a plurality of in a manner capable of dispersedly introducing the distillation target substance.

[0015] In the residual monomer removal device according to an embodiment of the present invention, the supply portion may be spaced apart at the same interval along the inner circumference of the main body portion.

[0016] In the residual monomer removal device according to an embodiment of the present invention, a plurality of the above-mentioned trays may be spaced apart by the same distance along the height direction of the main body portion.

[0017] The method for removing residual monomers by the residual monomer removal device according to the present invention may include the following steps: supplying a gas to the above-mentioned distillation target substance to generate a gas phase containing volatile substances and a distillation target substance from which volatile substances have been removed; and removing the gas phase and the distillation target substance from which volatile substances have been removed from the above-mentioned main body.

[0018] In the method for removing residual monomers according to an embodiment of the present invention, the above-mentioned distillation target substance may include a polymerization product of suspension polymerization or emulsion polymerization.

[0019] In the method for removing residual monomers according to an embodiment of the present invention, the above-mentioned distillation target substance may include a vinyl chloride monomer (VCM) that can be distilled.

[0020] The residual monomer removal device according to the present invention includes a tray formed with a spiral flow path, thereby preventing a dead zone where the distillation target substance does not flow or the flow rate decreases and the formation of foam that reduces the gas-liquid contact area, and thus excellent process efficiency can be maintained. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a partially cut-away perspective view showing a residual monomer removal device according to an embodiment of the present invention,

[0022] Figure 2 is showing Figure 1 a top view of a main part of the residual monomer removal device shown,

[0023] Figure 3 is Figure 1 a partially cut-away side view of the residual monomer removal device shown,

[0024] Figure 4 is a top view of a main part of a residual monomer removal device according to another embodiment of the present invention. DETAILED DESCRIPTION

[0025] For the technical terms and scientific terms used in this specification, unless otherwise defined, they have the meanings commonly understood by those skilled in the art to which the present invention pertains, and in the following description and drawings, descriptions of functions and configurations that may unnecessarily obscure the gist of the present invention are omitted.

[0026] In addition, the singular forms used in this specification are also intended to include plural forms as long as there is no specific indication in the context.

[0027] The term "comprising" in this specification is an open-ended description having an equivalent meaning to expressions such as "including", "containing", "having", or "characterized by", and does not exclude elements, materials, or processes not further enumerated.

[0028] The residual monomer removal device of the present invention is used to supply gas to a substance to be distilled to remove volatile substances, and includes: a main body portion, a supply portion, a gas inlet portion, a discharge portion, a recovery portion, a tray having a spiral flow path formed thereon, and a downcomer.

[0029] In the past, the tray of the residual monomer removal device had a zigzag flow path formed on the upper surface by a partition plate, and the substance to be distilled flowed along the formed flow path. Thus, near the corner of the flow path, since the substance to be distilled collided with the partition plate, a dead zone where the flow velocity of the flowing substance to be distilled decreased or did not flow was formed. Therefore, the solid matter of the substance to be distilled precipitated and blocked the holes for supplying gas, so that the substance to be distilled could not contact the gas, the volatile substances could not be sufficiently removed, the production efficiency decreased, and the quality of the produced PVC might decrease.

[0030] However, the residual monomer removal device of the present invention has a tray having a spiral flow path formed thereon, and on the upper surface of the tray, the substance to be distilled flows in a spiral shape. Therefore, the substance to be distilled flows at a constant flow velocity throughout the flow path, and it is possible to prevent the formation of a dead zone where there is no flow or the flow velocity decreases and foam that reduces the gas-liquid contact area. Thus, excellent process efficiency can be maintained.

[0031] Hereinafter, the residual monomer removal device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The accompanying drawings are always provided as examples to fully convey the technical idea of the present invention to those skilled in the art, and the present invention is not limited to the figures presented below and can be embodied in any other form arbitrarily.

[0032] In Figures 1 to 3 FIG. 1 shows a residual monomer removal device 100 according to an embodiment of the present invention.

[0033] Referring to Figures 1 to 3, the residual monomer removal device 100 of the present invention is used to remove the residual monomer in the polymer slurry from the distillation target substance by supplying gas. As a specific example, it can be a VCM stripper for removing volatile substances including vinyl chloride monomer (VCM), but is not limited thereto. The residual monomer removal device 100 of the present invention includes: a main body 10, a supply unit 30, a gas inlet unit 50, a discharge unit 70, a recovery unit 90, a tray 20 formed with a spiral flow path 25, and a down comer 40.

[0034] In the present invention, the distillation target substance refers to a form in which residual solvents and distillable monomers exist inside the polymer powder obtained by suspension polymerization or emulsion polymerization. For example, it can refer to a suspension polymer (PVC slurry) containing distillable VCM inside after suspension polymerization of polyvinyl chloride (PVC). Although suspension polymerization or emulsion polymerization is described by taking PVC as an example, it is not limited thereto.

[0035] In addition, in the present invention, the gas is used for gasification of residual monomers and residual solvents, etc., and can be gas or vapor, specifically, it can be steam.

[0036] The main body 10 provides an accommodation space for supplying gas to the distillation target substance accommodated therein. As shown in the figure, it can have a cylindrical chamber, but there is no limitation as long as it can form an accommodation space. The main body 10 is arranged perpendicular to the ground, and a plurality of trays 20 and down comers 40 are accommodated inside the main body 10. The inside of the main body 10 can be partitioned by the trays 20 in the vertical direction. In the main body 10, the distillation target substance flows in from the upper part of the main body 10, and the gas flows in from the lower part of the main body 10.

[0037] The supply unit 30 is arranged at the upper part of the main body 10 and is a pipe for introducing the distillation target substance. As the distillation target substance is supplied into the main body 10 through the supply unit 30 arranged at the upper part of the main body 10, the distillation target substance moves with a flow rate depending on gravity. Specifically, the supply unit 30 is arranged at a position on the upper side of the main body 10 relative to the uppermost tray 20 so that the introduced distillation target substance can move to the upper surface of the uppermost tray 20.

[0038] The gas inlet part is a pipe or duct for introducing gas, which is arranged at the lower part of the main body 10 in the direction opposite to the inflow direction of the substance to be distilled. Since the gas inlet part 50 is arranged at the lower part of the main body 10, the gas rises upward from the lower part to the upper part inside the main body 10.

[0039] The discharge part 70 is arranged at the upper part of the main body 10 and can be a pipe or duct for discharging the volatile substances separated from the substance to be distilled through the gas. Specifically, the volatile substances discharged through the discharge part 70 can be the residual solvents and distillable monomers contained in the substance to be distilled.

[0040] The recovery part 90 is arranged at the lower part of the main body and can be a pipe or duct for recovering the substance to be distilled after removing the volatile substances from the substance to be distilled. Specifically, the substance to be distilled after removing the volatile substances discharged through the recovery part 90 can be high-purity PVC after removing the residual solvents and distillable monomers.

[0041] A plurality of trays 20 are provided inside the main body 10. Each tray is formed with a through-hole 21a and a spiral flow path is formed on the upper surface. Specifically, the tray 20 can include a disk-shaped body 21 and a spiral baffle 23. The disk-shaped body 21 is positioned to divide the interior of the main body 10 into upper and lower parts in a direction, and the spiral baffle 23 is located on the upper surface of the disk-shaped body 21 and forms a spiral flow path.

[0042] Since a plurality of trays 20 as described above are provided inside the main body 10, the interior of the main body 10 can be divided into multiple layers. More specifically, the trays 20 can be arranged at the same interval along the height direction of the main body 10 perpendicular to the ground. For the trays 20 arranged at the same interval like this, when the upper tray 20 among any two adjacent trays 20 is set as the upper tray 20 and the lower tray 20 is set as the lower tray 20, since the height of movement from the upper tray 20 to the lower tray 20 is the same, the flow rate of the substance to be distilled determined by the potential energy can be the same in each layer formed by each tray 20. Thus, during the process design, the flow rate of the substance to be distilled inside the main body 10 can be easily controlled. For the uppermost tray 20, as shown in the figure, the supply part 30 can be located at its outer edge position and the downcomer 40 can be located at its central position, but it can also be different, with the supply part 30 located at its central position and the downcomer 40 located at its outer edge position.

[0043] The body 21 of the tray 20 may be formed with a plurality of through holes 21a penetrating in the upper and lower directions of the main body. The through holes 21a may be formed over the entire surface of the body 21, and preferably may be arranged in a concentrated manner on the bottom surface of the distillation target substance movement path, i.e., the spiral flow path 25. At this time, the lower surface of the body 21 may form a spiral pattern corresponding to the spiral flow path 25 due to the through holes 21a. The diameter of the through holes 21a formed in the body 21 may be 10 mm or less, preferably 1 to 5 mm, more preferably 1 to 3 mm, but is not limited thereto. The opening ratio of the body 21 (area of all through holes / area of the upper surface of the body) may be 0.01% to 30%, preferably 0.02% to 10%, but is not limited thereto.

[0044] The spiral baffle 23 rotates and extends from the center of the body 21 toward the outer edge direction to form the spiral flow path 25, and the distillation target substance may flow in a spiral shape on the upper surface of the tray 20 through the spiral baffle 23. Although the spiral baffle 23 may rotate and extend at various angles on the upper surface of the body 21 of the tray 20 in a manner to form various widths of the spiral flow path 25, preferably, it rotates and extends along the extension direction of the spiral baffle 23 in a manner to keep the width of the spiral flow path 25 constant. Since the spiral baffle 23 forms the spiral flow path 25 with a constant width as described above, a constant amount of the distillation target substance can flow through the flow path. Thereby, during the process design, the flow rate of the distillation target substance can be easily controlled.

[0045] As shown in the figure, the spiral baffle 23 rotates and extends in a curved shape to form the spiral flow path 25, and extends linearly in a partial section on the upper surface of the body 21 of the tray 20, thereby including an acceleration section 23a formed linearly in a part of the spiral flow path 25. The acceleration section 23a may be formed in a sector area with a central angle of 10° to 90°, preferably 20° to 80°, more preferably 30° to 60° with the center of the tray 20 as the center. By forming the acceleration section 23a in the sector area as described above, it is possible to further prevent the flow rate of the distillation target substance from decreasing due to friction generated during flow and contact with the gas supplied from the through holes 21a of the body 21.

[0046] The downcomer 40 is provided between the trays 20 and is a moving channel for the distillation target substance to move from the upper part to the lower part of the main body 10. When the upper tray 20 among the adjacent trays 20 is set as the upper tray 20 and the tray 20 located below it is set as the lower tray 20, the downcomer 40 is located between the upper tray 20 and the lower tray 20, so that the distillation target substance flowing in the upper tray 20 can move towards the lower tray 20. The downcomer 40 can be provided in multiple numbers along with the trays 20 being provided in multiple numbers. At this time, the downcomer 40 is located at the outer edge of the tray 20 or the center of the tray 20, and can alternate positions along the height direction of the main body 10.

[0047] Specifically, for the downcomer 40, when sequentially numbered from the upper part to the lower part of the main body, the nth downcomer 40 extends downward from the outer edge of the nth tray 20, and moves the distillation target substance to the upper surface of the outer edge of the (n + 1)th tray 20. Moreover, the (n + 1)th downcomer 40 extends downward from the center of the (n + 1)th tray 20, and moves the distillation target substance to the upper surface of the center of the (n + 2)th tray 20. In this way, the distillation target substance supplied to the tray 20 through the downcomer 40 can move to the next lower tray 20 located below through the next downcomer 40 after flowing along the spiral flow path 25.

[0048] Next, through Figure 3 the operation of the residual monomer removal device 100 according to an embodiment of the present invention will be described in detail.

[0049] Refer to Figure 3 , the distillation target substance is supplied into the main body 10 through the supply unit 30. The supplied distillation target substance is supplied to the upper part of the uppermost tray 20, rotates in the first direction A along the spiral flow path 25, and moves from the outer edge of the tray 20 towards the center. The moving distillation target substance is supplied to the upper center of the next lower tray 20 through the uppermost downcomer 40.

[0050] The supplied distillation target substance rotates in the second direction B along the spiral flow path 25, and moves from the center of the tray 20 towards the outer edge. In the figure, the first and second directions A and B are opposite to each other, but it goes without saying that they can rotate in the same direction.

[0051] In this way, the distillation target substance moves downward from the upper part to the lower part of the main body 10 along the tray 20 and the downcomer 40. When the distillation target substance moves along the spiral flow path 25 on the upper part of the tray 20, the gas supplied from the gas inlet is supplied to the distillation target substance through the through holes 21a formed in the trunk 21 of the tray 20. The distillation target substance separates volatile substances through the supplied gas, and the volatile substances are discharged through the discharge part 70 formed in the upper part of the main body 10. As it moves from the upper part to the lower part of the tray 20, the volatile substances are gradually removed, and the high-purity final product after removing the volatile substances is discharged from the main body 10 through the recovery part 90 provided in the lower part of the main body 10.

[0052] In the residual monomer removal device 100 of the present invention as described above, since the distillation target substance flows in a spiral shape through the spiral flow path 25 on the upper surface of the tray 20, the distillation target substance flows at a constant flow rate throughout the flow path, thereby preventing the formation of dead zones where there is no flow or the flow rate decreases and the formation of foams that reduce the gas-liquid contact area.

[0053] From the internal computational fluid dynamics (CFD) calculation results of the existing zigzag flow path and the spiral flow path of the present invention, it can be confirmed that in the existing flow path, blue dead zones where the fluid hardly flows are formed near each corner, but in the spiral flow path 25 of the present invention, the fluid flows in a constant manner as a whole without forming dead zones.

[0054] That is, the residual monomer removal device 100 of the present invention can make the distillation target substance flow stably by forming the spiral flow path 25, thereby preventing a decrease in process efficiency caused by precipitation and device failures, etc. Moreover, since the distillation target substance flows smoothly, even when the distillation target substance is supplied quickly to speed up the process, the retention and flow rate decrease of the distillation target substance can be prevented. Also, since the fluid can move without great friction, the foam generation rate is very low, thereby further improving the process efficiency.

[0055] In addition, the residual monomer removal device of the present invention can be provided with a plurality of supply parts 30 as Figure 4 shown.

[0056] In the residual monomer removal device 200 according to another embodiment of the present invention, the supply unit 30 may be formed in a plurality to be able to disperse and input the distillation target substance. Specifically, the plurality of supply units 30 may be arranged at the same interval along the inner periphery of the main body 10, and each supply unit 30 may discharge the distillation target substance at the same flow rate. As the flow rate of the distillation target substance discharged from a single supply unit 30 decreases in inverse proportion to the number of supply units 30, and the pressure difference between the supply unit 30 and the main body 10 decreases, foam generation due to the pressure difference can be prevented. The residual monomer removal device 200 of the present invention as described above can further prevent the formation of foam, thereby maximizing the effect of increasing the process efficiency.

[0057] In addition, the present invention is a method for removing residual monomers by the above-mentioned residual monomer removal device, which may include the following steps: inputting the distillation target substance into the main body; supplying gas to the distillation target substance to generate a gas phase containing volatile substances and a distillation target substance from which the volatile substances have been removed; and removing the gas phase and the distillation target substance from which the volatile substances have been removed from the main body.

[0058] In the present invention, the distillation target substance includes the polymerization products of suspension polymerization or emulsion polymerization. Specifically, it may include the suspension polymerization products or emulsion polymerization products of PVC. Examples of polymerizable monomers that can react with VCM to polymerize may include: carboxylic acid esters of vinyl alcohol (e.g., vinyl acetate), vinyl ethers (e.g., alkyl vinyl ethers), unsaturated carboxylic acid esters (e.g., acrylates and methacrylates), vinylidene halides (e.g., 1,1-dichloroethylene and 1,1-difluoroethylene), unsaturated nitriles (e.g., acrylonitrile), and olefins (e.g., ethylene and propylene), but are not limited thereto.

[0059] In the present invention, the distillation target substance is preferably a liquid dispersion (PVC slurry) containing polymerized PVC, unreacted residual monomers (VCM), and mainly water. And as needed, in addition to buffering agents, particle size regulators, scale inhibitors, defoaming agents, etc., it may also contain a small amount of dispersants such as polyvinyl alcohol or hydroxypropyl methylcellulose.

[0060] Specifically, in the step of inputting the distillation target substance into the main body, the concentration of the slurry of the distillation target substance, that is, the concentration of the PVC slurry, is preferably 5 to 50% by weight, more preferably 10 to 40% by weight. When the concentration of the distillation target substance is greater than 50% by weight, the fluidity is very low, and when the concentration is less than 5% by weight, the removal efficiency of the residual monomer decreases significantly.

[0061] In the step of supplying a gas to the distillation target substance to generate a gas phase containing a volatile substance and a distillation target substance from which the volatile substance has been removed, the gas gushing amount is preferably 1 to 100 kg / h, more preferably 5 to 50 kg / h per 1 m of the region formed by the distillation target substance, but is not limited thereto. At this time, the temperature and gushing amount of the gas can be adjusted so that the temperature of the distillation target substance flowing above the uppermost tray becomes 50 to 150 °C, specifically 70 to 120 °C, and more specifically 80 to 110 °C, but is not limited thereto. 3 In the step of removing the gas phase and the distillation target substance from which the volatile substance has been removed from the main body, the volatile substance is discharged through the discharge part, and the distillation target substance from which the volatile substance has been removed is discharged to the recovery part. The distillation target substance from which the volatile substance has been removed may be high-purity PVC from which VCM has been removed. The process efficiency of the residual monomer removal method carried out by the above-mentioned residual monomer removal device is excellent, and high-purity products can be manufactured.

[0062] As described above, in the present invention, it has been described by specific matters, limited embodiments, and drawings, but they are only provided for a more complete understanding of the present invention. The present invention is not limited to the above embodiments, and those skilled in the art of the present invention can make various modifications and deformations based on these descriptions.

[0063] Therefore, the idea of the present invention is not limited to the described embodiments, and not only the scope of the following claims but also all forms equivalent to or having equivalent deformations of the scope of the claims belong to the scope of the idea of the present invention.

[0064] ​

Claims

1. A residual monomer removal device, Among them, including: a main body portion capable of supplying a gas to a distillation target substance accommodated therein; a distillation target substance supply portion provided at an upper portion of the main body portion for introducing the distillation target substance; a gas inlet portion provided at a lower portion of the main body portion for introducing the gas; a discharge portion provided at an upper portion of the main body portion for discharging a volatile substance separated from the distillation target substance by the gas; a recovery portion provided at a lower portion of the main body portion for recovering the distillation target substance after removing the volatile substance from the distillation target substance; a plurality of trays provided inside the main body portion, each tray having a through hole formed therein and a spiral flow path formed therein; and a downcomer provided between the trays and serving as a moving passage for the distillation target substance to move from an upper portion to a lower portion of the main body portion, wherein the tray includes a disk-shaped body and a spiral baffle, the disk-shaped body is positioned to divide the inside of the main body portion into upper and lower directions, and the spiral baffle is located on an upper surface of the body and rotates and extends from a central portion of the body toward an outer edge direction to form the spiral flow path, wherein the downcomer is located at an outer edge or the center of the tray and alternates positions along the height direction of the main body portion.

2. The residual monomer removal device according to claim 1, wherein, the width of the spiral flow path is constant.

3. The residual monomer removal device according to claim 1, wherein, the supply portion is formed in a plurality of numbers so as to be able to disperse and introduce the distillation target substance.

4. The residual monomer removal device according to claim 3, wherein, the supply portions are spaced apart from each other by the same distance along the inner circumference of the main body portion.

5. The residual monomer removal device according to claim 1, wherein, the plurality of trays are spaced apart from each other by the same distance along the height direction of the main body portion.

6. A method for removing residual monomers, which is a method for removing residual monomers by using the residual monomer removing device according to any one of claims 1 to 5, wherein, including the following steps: introducing the distillation target substance into the main body portion; supplying a gas to the distillation target substance to generate a gas phase containing a volatile substance and a distillation target substance from which the volatile substance has been removed; and removing the gas phase and the distillation target substance from which the volatile substance has been removed from the main body.

7. The residual monomer removal method according to claim 6, wherein, the distillation target substance includes a polymerization product obtained by suspension polymerization or emulsion polymerization.

8. The residual monomer removal method according to claim 7, wherein, the distillation target substance includes a vinyl chloride monomer capable of being distilled.

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