JP2013203840A - Operation method of continuous polymerization apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an operation method of continuous polymerization apparatus, capable of smoothly performing stop and restart of continuous polymerization in a multistage serial continuous polymerization apparatus.SOLUTION: A raw material monomer is continuously supplied to a complete mixing type first reaction tank (10) with the supply of a polymerization initiator to the first reaction tank being stopped, raw material monomer-containing fluid in the first reaction tank is continuously extracted with stirring from the first reaction tank as first fluid, the first fluid is continuously supplied from the first reaction tank to a complete mixing type second reaction tank (20) through a connection line (15), and raw material monomer-containing fluid in the second reaction tank is continuously extracted with stirring from the second reaction tank as second fluid. The temperature of the first fluid passing through the connection line is adjusted by a temperature adjustment means (16) of the connection line (15) so that pressure difference P-Pbetween pressure Pin the first reaction tank (10) and pressure Pin the second reaction tank (20) is 0-0.05 MPa.

Description

  The present invention relates to a method for operating a continuous polymerization apparatus, and more particularly to a method for operating a continuous polymerization apparatus while continuous polymerization is stopped in the continuous polymerization apparatus.

  A resin composition such as a methacrylic acid ester polymer is produced by continuous polymerization in which raw material monomers, a polymerization initiator, and the like are continuously supplied to a reaction vessel and polymerized. As such a continuous polymerization method, a continuous solution polymerization method in which continuous polymerization is performed using a solvent (or a dispersion medium, the same applies hereinafter) is also possible, but a continuous bulk polymerization method in which continuous polymerization is performed without using a solvent (for example, Patent Document 1). Is more efficient).

  When the continuous polymerization method is used industrially, in addition to a continuous polymerization apparatus including a reaction vessel for carrying out continuous polymerization, apparatuses such as a preheater and a devolatilizing extruder are usually arranged downstream of the continuous polymerization apparatus. The polymer composition produced in this manner is continuously transferred to these downstream devices for processing. In these downstream apparatuses, when performing inspection and / or repair work due to regular maintenance or trouble occurrence, it is necessary to stop the continuous polymerization in the continuous polymerization apparatus. With regard to such a stopping method, it has been proposed to add a chain transfer agent so that the melt flow rate of the polymer falls within a predetermined range before stopping the supply of the raw material monomer and the polymerization initiator to the reaction vessel (patent) Reference 2). In addition, supply of the polymerization initiator to the reaction tank is stopped, and the supply flow rate of the raw material monomer to the reaction tank is adjusted so that the temperature in the reaction tank and the temperature of the outer wall of the reaction tank satisfy a predetermined relationship. It has also been proposed (Patent Document 3).

JP 07-126308 A JP 2010-229318 A JP 2006-131847 A

  However, the conventional continuous polymerization apparatus operating method (Patent Documents 2 and 3) for stopping the continuous polymerization is a multistage serial polymerization apparatus, more specifically, at least two fully mixed reaction vessels in series. It has been found that it is not necessarily sufficient for a continuous polymerization apparatus that is used in a connected manner, and in which a raw material monomer and a polymerization initiator are subjected to continuous polymerization in these reaction vessels.

  An object of the present invention is to provide a method for operating a continuous polymerization apparatus capable of smoothly stopping and restarting continuous polymerization in a multistage continuous polymerization apparatus.

  In a multi-stage continuous polymerization apparatus, after adding a chain transfer agent so that the melt flow rate of the polymer falls within a predetermined range, the supply of the raw material monomer and the polymerization initiator to the reaction vessel is stopped (Patent Document 2). When this method is applied to a multi-stage continuous polymerization apparatus), while continuous polymerization is stopped, at least two reaction vessels and a material such as a raw material monomer are connected to the connection line connecting these reaction vessels in series. Since it remains as it is, if it is stopped for a long time, the pipe line of the connection line may be narrowed or blocked, and the continuous polymerization cannot be resumed smoothly. Also, in a multi-stage continuous polymerization apparatus, the supply of the polymerization initiator to the reaction tank is stopped, and the reaction tank temperature and the outer wall surface temperature of the reaction tank satisfy a predetermined relationship. When the supply flow rate of the raw material monomer is adjusted (when the method of Patent Document 3 is applied to a multistage continuous polymerization apparatus), at least two reaction tanks and these reactions are performed while continuous polymerization is stopped. The raw material monomer will circulate through the connection line connecting the tanks in series, but if it is stopped for a long time, the pipe line of the connection line connecting the reaction tanks in series is narrowed or blocked. As a result, the pressure in the previous reaction tank rises and the pressure difference between the reaction tanks may increase, and the continuous polymerization cannot be resumed smoothly. In view of such problems, the present inventors have earnestly studied the operation method of a continuous polymerization apparatus capable of smoothly stopping and resuming continuous polymerization even in a multistage continuous polymerization apparatus, and the present invention. It came to complete.

The present invention provides the following [1] to [4].
[1] Continuous while the continuous polymerization is stopped in the continuous polymerization apparatus in which the raw material monomer and the polymerization initiator are subjected to continuous polymerization in the first and second reaction tanks of the complete mixing type connected in series by the connection line. A method of operating a polymerization apparatus,
The raw material monomer is continuously supplied to the first reaction tank in a state where the supply of the polymerization initiator to the fully mixed first reaction tank is stopped, and the raw material monomer-containing fluid in the first reaction tank With continuous stirring as the first fluid from the first reaction vessel,
The first fluid is continuously supplied from the first reaction tank to a fully mixed second reaction tank through a connection line equipped with temperature control means, and in the absence of a new polymerization initiator, Continuously extracting as a second fluid from the second reaction tank while stirring the raw material monomer-containing fluid in the second reaction tank,
The first so that the pressure difference _P 1 -P ₂ of the pressure _{P 1} in the reaction vessel and the pressure _{P 2} of the second reaction vessel is less than 0.05MPa or 0 MPa, temperature adjustment of the connecting line Adjusting the temperature of the first fluid through the connecting line by means.
[2] The temperature of the connection line so that the temperature difference T _m -T ₁ between the temperature T ₁ in the first reaction tank and the set temperature T _m of the temperature control means of the connection line is 10 ° C. or more and 60 ° C. or less. adjusting the set temperature T _m of a regulating unit, the operation method of the continuous polymerization apparatus according to [1].
[3] In the above [2], the pressure P ₁ in the first reaction tank is 1.0 to 2.0 MPa in gauge pressure, and the temperature T ₁ in the first reaction tank is 120 to 170 ° C. A method for operating the described continuous polymerization apparatus.
[4] The operation method of the continuous polymerization apparatus according to any one of [1] to [3], wherein the raw material monomer contains 50% by mass or more of methyl methacrylate, and the continuous polymerization is continuous bulk polymerization.

ADVANTAGE OF THE INVENTION According to this invention, even if it is a multistage continuous polymerization apparatus, the operation method of the continuous polymerization apparatus which can perform the stop and restart of continuous polymerization smoothly is provided. According to the method of operating the continuous polymerization apparatus of the present invention, the raw material monomer-containing fluid flows through the first and second reaction vessels and the connection line connecting these reaction vessels in series, and the temperature of the connection line is adjusted. by means by adjusting the first temperature of the fluid through the connection line, the pressure difference P ₁ -P ₂ of the pressure P ₁ in the first reaction vessel and the pressure P ₂ in the second reaction vessel It can be controlled to be 0 MPa or more and 0.05 MPa or less, thereby effectively preventing the connection line from being narrowed or blocked even if continuous polymerization is stopped for a relatively long time. be able to.

It is the schematic explaining the operation method of the continuous polymerization apparatus in one embodiment of this invention. In the embodiment of FIG. 1, it is the schematic which shows the example of the continuous polymerization apparatus which provided the heating-cooling apparatus in the connection line.

  First, a continuous polymerization apparatus to which the operation method of the present invention is applied and a method for producing a polymer composition using the same will be described.

  The continuous polymerization apparatus to which the operation method of the present invention is applied is a continuous polymerization apparatus in which a raw material monomer and a polymerization initiator are subjected to continuous polymerization in first and second reaction tanks of a completely mixed type connected in series by a connection line. If it is. Such a continuous polymerization apparatus includes at least two reaction tanks, and continuous polymerization, for example, continuous bulk polymerization or continuous solution polymerization can be performed in each reaction tank. Such a continuous polymerization apparatus is understood as a continuous bulk polymerization apparatus when continuous bulk polymerization is carried out in all reaction vessels, and as a continuous solution polymerization apparatus when continuous solution polymerization is carried out in all reaction vessels. Is done. However, the present invention is not limited to these, and the continuous polymerization apparatus performs continuous bulk polymerization in a certain reaction vessel (for example, at least one reaction vessel in the preceding stage), and a certain reaction vessel (for example, at least one reaction vessel in the subsequent stage). Then, continuous solution polymerization may be performed.

  As shown in FIG. 1, the continuous polymerization apparatus used in the present embodiment includes a first reaction tank 10 and a second reaction tank 20. These reaction tanks 10 and 20 are both complete mixing type reaction tanks, and are used for carrying out continuous bulk polymerization in this embodiment.

  More specifically, the first reaction tank 10 has a supply port 11a, an extraction port 11b, and a stirrer 14 for stirring the contents, and preferably adjusts the temperature of the outer wall surface of the reaction tank. A jacket 13 is further provided as a temperature adjusting means for this purpose. Similarly, the 2nd reaction tank 20 has the supply port 21a, the extraction port 21b, and the stirrer 24 for stirring the contents, Preferably, it is the temperature for adjusting the temperature of the outer wall surface of a reaction tank. A jacket 23 surrounding the outer wall surface of the reaction vessel is further provided as adjusting means. The extraction ports 11b and 21b are provided so as to be positioned at the top of each reaction tank in the present embodiment, but are not limited thereto. On the other hand, although supply port 11a and 21a do not limit this embodiment, generally it can be provided in the appropriate position under each reaction tank. Furthermore, these reaction tanks 10 and 20 are each provided with a temperature sensor T as temperature detection means for detecting the temperature in each reaction tank and a pressure sensor P as pressure detection means for detecting the pressure in each reaction tank. In addition, the detection part of the pressure sensor P does not necessarily need to be provided in the reaction tanks 10 and 20 as long as the pressure in the reaction tank can be grasped. For example, a connection described later is provided outside the reaction tanks 10 and 20. On the line 15 and the extraction line 25, it may be provided in the vicinity of the extraction ports 11b and 21b (in FIG. 1, the symbol P is surrounded by a dotted line).

  The volume of the 1st reaction tank 10 and the 2nd reaction tank 20 may mutually be the same, or may differ. By making the volume of the first reaction tank 10 and the volume of the second reaction tank 20 different, the average residence time is effectively made different between the first reaction tank 10 and the second reaction tank 20. Can do.

  The agitators 14 and 24 are for bringing the inside of the reaction tank into a substantially complete mixed state. These agitators may be equipped with any appropriate agitating blade, such as a MIG wing, a Max blend wing (registered trademark, manufactured by Sumitomo Heavy Industries, Ltd.), a paddle wing, a double helical ribbon wing, a full zone. Wings (registered trademark, manufactured by Shinko Environmental Solution Co., Ltd.) may be provided. In order to increase the stirring effect in the reaction vessel, it is desirable to attach a baffle in the reaction vessel. However, the present embodiment is not limited to this, and may have any appropriate configuration in place of the stirrers 14 and 24 as long as the inside of the reaction vessel can be substantially completely mixed.

Although the reaction tanks 10 and 20 are generally preferable as the stirring efficiency is higher, the stirring power should not be larger than necessary from the viewpoint of not adding an excessive amount of heat to the reaction tank by the stirring operation. Although stirring power is not specifically limited, Preferably, it is 0.5-30 kW / m < ³ >, More preferably, it is 1-15 kW / m < ³ >. The stirring power is preferably set larger as the viscosity of the reaction system becomes higher (or as the content of the polymer in the reaction system becomes higher).

  As shown in the figure, the supply port 11a of the first reaction tank 10 is pumped to a raw material monomer tank (raw material monomer supply source) 1 and a polymerization initiator tank (a polymerization initiator and optionally a raw material monomer supply source) 3 respectively. The raw material supply line 9 is connected through 5 and 7. In the present embodiment, the raw material monomer and polymerization initiator supply sources are the raw material monomer tank 1 and the polymerization initiator tank 3, but the number of raw material monomer and polymerization initiator supply sources and the raw material monomer and polymerization initiator modes (For example, in the case of a mixture, the composition thereof) is not particularly limited as long as the raw material monomer and the polymerization initiator can be appropriately supplied to the first reaction vessel 10. Although not essential to the present embodiment, another supply port 11c is provided in the first reaction tank 10, and this supply port 11c is connected to the polymerization initiator tank 3 with a pump 7 as shown by a dotted line in FIG. It may be connected via. The extraction port 11 b of the first reaction tank 10 is connected to the supply port 21 a of the second reaction tank 20 through the connection line 15. The extraction port 21 b of the second reaction tank 20 is connected to the extraction line 25. Thereby, the 1st reaction tank 10 and the 2nd reaction tank 20 are connected in series. It is preferable that no pump exists on the connection line 15 between the extraction port 11b of the first reaction tank 10 and the supply port 21a of the second reaction tank 20.

  Although not essential for the present invention, the second reaction tank 20 is preferably connected to a polymerization initiator tank 17 (a supply source of a new polymerization initiator and optionally a raw material monomer) via a pump 19. In this embodiment, the supply source of the new polymerization initiator is the polymerization initiator tank 17, but the number of supply sources of the new polymerization initiator and the mode of the polymerization initiator (for example, the composition in the case of a mixture) There is no particular limitation as long as a new polymerization initiator can be appropriately supplied to the second reaction vessel 20. When the polymerization initiator tank 17 and the pump 19 are present, the supply port 21a of the second reaction tank 20 is connected to the polymerization initiator tank 17 through the connection line 15 via the pump 19 as shown in FIG. Alternatively, another supply port 21 c is provided in the second reaction tank 20, and this supply port 21 c is connected to the polymerization initiator tank 17 via the pump 19, for example, as shown by a dotted line in FIG. May have been.

  The pumps 5 and 7 and the pump 19 when present are not particularly limited, but the flow rate from the raw material monomer tank 1 and the polymerization initiator tank 3, and when present, from the polymerization initiator tank 17. A pump that can set the flow rate to a constant amount is preferable. Specifically, a multiple reciprocating pump is preferable, and a non-pulsating constant pump such as a double non-pulsating metering pump or a triple non-pulsating metering pump is more preferable. Thereby, the supply amount (or supply flow rate, the same applies hereinafter) of the raw material monomer and the polymerization initiator to the first reaction tank 10 and, in some cases, the polymerization initiator (or the raw material monomer and the second reaction tank 20). The additional supply amount of the polymerization initiator) can be controlled.

  Further, the connection line 15 that connects the extraction port 11b of the first reaction tank 10 to the supply port 21a of the second reaction tank 20 is the temperature of the fluid that passes through the connection line 15 (hereinafter, simply referred to as the temperature in the connection line 15). As a temperature adjusting means capable of adjusting the temperature of the jacket 16 (shown by hatching in FIG. 1) surrounding a part or all of the outer wall surface of the connection line 15, or the connection line 15 as shown in FIG. A heating / cooling device 40 partially replaced, a trace pipe for passing a heat medium, and the like are provided (a connection line including a jacket is understood as a double pipe). Thereby, the temperature of the connection line 15 (more specifically, the temperature in the connection line 15) can be adjusted in accordance with the temperature and pressure of the first reaction tank 10 and / or the second reaction tank 20. it can. As described above, the first reaction tank 10 includes the temperature sensor T as temperature detecting means for detecting the temperature in the first reaction tank 10, and thus the jacket 16 and the heating / cooling device 40 of the connection line 15. The (temperature adjusting means) is such that the temperature in the connection line 15 becomes substantially the same as the temperature in the first reaction vessel 10 detected by the temperature sensor T during continuous polymerization. Or the temperature in the connection line 15 in the vicinity of the supply port 21a of the second reaction tank 20 is lower than the temperature in the first reaction tank 10 detected by the temperature sensor T. Can be controlled. In FIG. 2, the heating / cooling device 40 is provided in the connection line 15 in any appropriate manner, and the line portion other than the heating / cooling device 40 of the connection line 15 is covered with a heat insulating material (not shown) for heat insulation. Alternatively, a jacket (not shown in FIG. 2) surrounding the outer wall surface of the connection line 15 may be used in combination.

  In addition, although not essential to the present invention, the connection line 15 improves the uniformity of the temperature distribution in the connection line 15 and is based on a fluid (described later) that passes through the connection line 15 (more specifically, such fluid). It is preferable to provide a mixing means in that blockage of the connection line 15 (due to a polymer that can be contained in) can be suppressed. The mixing means is preferably provided in the temperature adjustment portion of the connection line 15 in terms of increasing the thermal efficiency. Examples of the mixing means include a static mixer and a dynamic mixer. Among them, a static mixer is preferable. The static mixer is a mixer that does not require a drive unit, and is provided in the connection line 15 in any appropriate manner. For example, in FIG. 1, a static mixer may be inserted at an appropriate position inside the connection line 15, or a part or all of the connection line 15 may be replaced with a static mixer that forms a line. . In FIG. 2, a static mixer may be inserted at an appropriate position inside the line portion other than the heating / cooling device 40 of the connection line 15, or a part of the line portion other than the heating / cooling device 40 of the connection line 15. Alternatively, the whole may be replaced by a static mixer that forms a line. Examples of the static mixer include “Sulzer Mixer” manufactured by Sulzer Chemtech Ltd. For example, SMX type, SMI type, SMV type, SMF type, SMXL type, etc. are used. Can be done.

  In the embodiment of FIG. 2, the heating / cooling device 40 may be provided as the heating / cooling device 40, which has both temperature adjusting means and mixing means. Examples of the heating / cooling device 40 having both the temperature adjusting unit and the mixing unit include a heating / cooling device having a dynamic mixing function and a heating / cooling device having a static mixing function. Examples of the heating / cooling device having a dynamic mixing function include a screw mixer capable of heating and cooling a cylinder. Examples of the heating / cooling device having a static mixing function include a static mixer built-in heat exchanger. As the heat exchanger with a built-in static mixer, an SMR-type sulzer mixer manufactured by Sruzer Chemtech Co., Ltd. is preferably used in terms of a large heat transfer area and high thermal efficiency. When a heat exchanger with a built-in static mixer is used as the heating / cooling device 40, a part or all of the connection line 15 may be replaced with a heat exchanger with a built-in static mixer that forms a line.

Each member described above with reference to FIG. 1 is preferably connected as appropriate to a control means (not shown), which will be described later, and is configured as a whole so that its operation can be controlled by the control means. Thereby, the temperature of the outer wall surface of the reaction tank set for the jackets (temperature adjusting means) 13 and 23 and the temperature in the reaction tank detected by the temperature sensor (temperature detection means) T are the first In order to match each of the reaction tank 10 and the second reaction tank 20 (in other words, to achieve an adiabatic state in each of the first reaction tank 10 and the second reaction tank 20), the raw material monomers and The amount of the polymerization initiator supplied to the first reaction vessel 10 can be adjusted by adjusting the operation of the pumps 5 and 7, or the temperature of the outer wall surface of the reaction vessel set for the jackets 13 and 23 can be adjusted. Further, when the polymerization initiator tank 17 and the pump 19 are present, an additional supply amount of the polymerization initiator (or raw material monomer and polymerization initiator) to the second reaction tank 20 is pumped. It is possible to adjust the operation of 9. In addition, the jacket (temperature adjusting means) 16 that covers the connection line 15 is set so that the polymerization temperature in the second reaction tank 20 does not become too high while achieving the desired polymerization rate in the second reaction tank 20. is controllable by adjusting the temperature T _m, in FIG. 2 can be controlled by adjusting the set temperature of the heating and cooling device 40 obtained by replacing part of the connecting line 15. It is preferable that the temperature in the connection line 15 is actually measured by temperature detection means for detecting the temperature in the connection line 15 in the vicinity of the supply port 21a of the second reaction tank 20 and in some other places. However, depending on the polymerization reaction conditions in the first reaction vessel 10, the polymerization reaction of an intermediate composition (described later) extracted from the extraction port 11b may be caused by factors such as consumption of the supplied polymerization initiator. 15, the polymerization reaction heat may not be generated in the connection line 15. In such a case, the temperature in the connection line 15 in the vicinity of the outlet 11 b of the first reaction tank 10 is The temperature in the first reaction vessel 10 detected by the temperature sensor (temperature detection means) T may be considered as substantially the same temperature. In such a case, the set temperature of the jacket 16 covering the connection line 15 or the set temperature of the heating / cooling device 40 replacing a part of the connection line 15 is equal to or higher than the temperature in the first reaction vessel 10. It is considered that the temperature in the connection line 15 in the vicinity of the supply port 21a of the second reaction tank 20 is equal to or lower than the temperature in the first reaction tank 10 by making the temperature lower. In addition, in FIG. 2, when the jacket which surrounds the circumference | surroundings is provided in line parts other than the heating / cooling apparatus 40 of the connection line 15, you may adjust the temperature in the connection line 15 by using this jacket together. .

  The jackets 13 and 23 cover substantially the entire reaction tanks 10 and 20, respectively, and react by introducing a heat medium such as steam, hot water, or an organic heat medium from a heat medium supply path (not shown). The tanks 10 and 20 are appropriately heated or kept warm. The temperatures of the jackets 13 and 23 can be appropriately adjusted depending on the temperature or pressure of the supplied heat medium. The heat medium introduced into the jackets 13 and 23 is removed from the heat medium discharge path (not shown). The temperature and pressure of the jackets 13 and 23 are detected by a sensor such as a temperature sensor (not shown) provided on the heat medium discharge path. The location of the sensor such as the temperature sensor is not particularly limited, and may be on the heat medium supply path or in the jackets 13 and 23, for example. The jacket 16 provided as the temperature adjusting means in the connection line 15 may have the same configuration as the jackets 13 and 23. Although not limited to this embodiment, typically, the connecting line 15 may be a double tube, and the inner space of the inner tube is a fluid (as described below, an intermediate composition during continuous polymerization). Yes, it is a raw material monomer-containing fluid when continuous polymerization is stopped), and the space between the inner tube and the outer tube is a heat medium channel (jacket 16).

The polymerization reaction in the reaction tanks 10 and 20 is required to be performed with the polymerization temperature substantially constant in the reaction tanks 10 and 20, respectively, from the viewpoint of making the quality of the produced polymer (polymer) constant. . Therefore, the temperature adjusting means (jackets 13 and 23) is controlled to a preset constant temperature so that the internal temperatures of the reaction vessels 10 and 20 can be kept substantially constant.
The set temperature of the temperature adjusting means (jackets 13 and 23) is transmitted to the control means to be described later, and the supply flow rate by the monomer supply means (pump 5) and the initiator supply means (pump 7 and pump 19 if present). Data for determining whether or not the control is necessary. The set temperature of the temperature adjusting means (jackets 13 and 23) can be adjusted by controlling the temperature or pressure of the heating medium.

Examples of the control means include a control unit (not shown) including a CPU, a ROM, a RAM, and the like.
The ROM of the control unit is a device for storing a program for controlling the pumps 5 and 7, and the pump 19 if present, and the RAM of the control unit is used to execute the above-described program. Is a device that temporarily stores the temperature data in the reaction vessels 10 and 20 detected in step 1, the set temperature data of the jackets 13 and 23, and the set temperature data of the jacket 16 or the heating / cooling device 40 of the connection line 15. is there.

  The CPU of the control unit executes the program stored in the ROM based on the temperature data in the reaction vessels 10 and 20 and the set temperature data of the jackets 13 and 23 stored in the RAM, and performs a reaction. The supply flow rate of the raw material monomer and / or polymerization initiator into the tanks 10 and 20 is controlled by monomer supply means (pump 5) and / or initiator supply means (pump 7 and pump 19 if present). Further, regarding the jacket 16 or the heating / cooling device 40 provided as the temperature adjusting means in the connection line 15, the CPU of the control unit stores the temperature data in the reaction tanks 10 and 20 stored in the RAM and the connection line 15. Based on the data on the set temperature of the jacket 16 or the heating / cooling device 40, and the temperature in the connection line 15 in the vicinity of the supply port 21a of the second reaction tank 20 and other places when actually measured, A program stored in the ROM (part of the above program or a program different from the above program) may be executed to adjust the set temperature of the jacket 16 of the connection line 15 or the heating / cooling device 40 Can do.

An example of control by the control means (control unit) is shown below.
When the temperature in the reaction vessel 10 detected by the temperature sensor T exceeds the set temperature of the jacket 13 which is a temperature adjusting means, the CPU executes the program in the ROM, for example, into the reaction vessel 10. The pump 7 is controlled so as to reduce the supply flow rate of the polymerization initiator. When the polymerization initiator tank 17 and the pump 19 are present, the temperature in the reaction tank 20 detected by the temperature sensor T is adjusted while the polymerization initiator is supplied to the reaction tank 20 by the pump 19 and the polymerization is performed. When the set temperature of the jacket 23, which is a means, is exceeded, the program in the ROM is executed by the CPU, thereby controlling the pump 19 so as to decrease the flow rate of the polymerization initiator supplied into the reaction vessel 20, for example. To do. By executing such control, the heat of polymerization generated in the reaction vessel 10 and / or 20 can be reduced, and as a result, the temperature in the reaction vessel 10 and / or 20 can be lowered.

  On the other hand, when the temperature of the reaction vessel 10 is lower than the set temperature of the jacket 13, for example, the supply flow rate of the polymerization initiator into the reaction vessel 10 is increased by executing the program in the ROM by the CPU. The pump 7 is controlled. When the polymerization initiator tank 17 and the pump 19 are present, the polymerization initiator is supplied to the reaction tank 20 by the pump 19 and the polymerization is being performed. When the temperature of the reaction tank 20 falls below the set temperature of the jacket 23, the CPU By executing the program in the ROM, the pump 19 is controlled so as to increase the supply flow rate of the polymerization initiator into the reaction vessel 20, for example. By executing such control, the heat of polymerization generated in the reaction vessel 10 and / or 20 can be increased, and as a result, the temperature in the reaction vessel 10 and / or 20 can be increased.

  Further, for example, in the polymerization reaction in the reaction tanks 10 and 20, when the pump 7 and the pump 19 if present are controlled, the total supply flow rate into the reaction tanks 10 and 20 is significantly reduced. 7 and if present, it is preferable not only to control the pump 19 to decrease the supply flow rate of the polymerization initiator, but also to simultaneously control the pump 5 to increase the supply flow rate of the raw material monomer.

  Furthermore, the following control is mentioned as another control example. That is, when the temperature in the reaction vessel 10 detected by the temperature sensor T exceeds the set temperature of the jacket 13 that is a temperature adjusting means, the supply flow rate of the raw material monomer is increased by controlling the pump 5 to react. The relative supply flow rate of the polymerization initiator into the tank 10 is decreased. Also by such control, the temperature in the reaction vessel 10 can be lowered.

The ratio between the supply flow rate of the raw material monomer and the supply flow rate of the polymerization initiator may be appropriately set according to the type of polymer to be produced, the type of polymerization initiator to be used, and the like.
In addition, the supply flow rate of the raw material monomer and the extent to increase or decrease the supply flow rate of the polymerization initiator are appropriately set according to the type of polymer to be generated (polymer), the type of polymerization initiator to be used, and the like. Is. However, when what is supplied into the reaction tanks 10 and 20 by the initiator supply means is not a polymerization initiator alone but a raw material monomer containing a polymerization initiator, the supply flow rate of the polymerization initiator is the polymerization start It is necessary to control in consideration of the content ratio of the polymerization initiator in the raw material monomer including the agent.

  Furthermore, as another control example, the following control can be given for the jacket 16 or the heating / cooling device 40 provided as the temperature adjusting means in the connection line 15. When the temperature in the connection line 15 in the vicinity of the supply port 21a of the second reaction tank 20 is equal to or higher than the temperature in the first reaction tank 10 detected by the temperature sensor T, the CPU stores the temperature in the ROM. By executing the program, the temperature in the connection line 15 in the vicinity of the supply port 21a of the second reaction tank 20 is equal to or lower than the temperature in the first reaction tank 10, for example, 5 to 80 ° C. Control related equipment (not shown) of the jacket 16 or the heating / cooling device 40 so as to adjust the set temperature of the jacket 16 or the heating / cooling device 40 of the connection line 15 to the same or lower temperature so that the temperature is low. To do. The set temperature of the jacket 16 of the connection line 15 is not particularly limited, but is generally adjustable by controlling the flow rate and / or temperature of the heat medium flowing through the jacket 16. The set temperature of the heating / cooling device 40 in the connection line 15 is not particularly limited. However, when a heat exchanger with a built-in static mixer is used as the heating / cooling device 40, a heat medium that generally flows through the heat exchanger with a built-in static mixer is used. Can be adjusted by controlling the flow rate and / or temperature of the liquid.

  As a preferred control example, the following control can be performed. The temperature in the second reaction tank 20 detected by the temperature sensor T in the second reaction tank 20 is equal to or higher than the temperature in the first reaction tank 10 detected by the temperature sensor T in the first reaction tank 10. In some cases, the CPU executes the program in the ROM so that the temperature in the connection line 15 near the supply port 21a of the second reaction tank 20 is equal to or equal to the temperature in the first reaction tank 10. The setting temperature of the jacket 16 of the connection line 15 or the heating / cooling device 40 (and the jacket when the heating / cooling device 40 and the jacket are used together) is appropriately set so that the temperature becomes lower than that, for example, 5 to 80 ° C. As described above, the pumps 5 and 7 and the pump 19 if present are controlled so as to adjust the supply flow rate to the reaction tank 10 and / or the reaction tank 20. It may be or, thereby, able to reduce the difference between the temperature of the temperature in the first reaction vessel 10 and the second reaction vessel 20. When polymerization heat is generated in the second reaction tank 20 due to the presence of the polymerization initiator tank 17 and the pump 19, the jacket 16 or the heating / cooling device 40 (and the heating / cooling device 40 and the jacket of the connection line 15). It is effective to adjust the set temperature of the jacket) when using together.

  In addition, although not essential for the present embodiment, a preheater 31 and a devolatilizing extruder 33 can be usually arranged downstream of the extraction line 25. A pressure regulating valve (not shown) may be provided between the preheater 31 and the devolatilizing extruder 33. The extrudate after devolatilization is taken out from the take-out line 35.

  Any suitable heater can be used as the preheater 31 as long as the viscous fluid can be heated. The devolatilizing extruder 33 may be a screw type single-screw or multi-screw devolatilizing extruder.

  Furthermore, there may be a recovery tank 37 for storing raw material monomers separated and recovered from volatile components (mainly comprising unreacted raw material monomers) separated by the devolatilizing extruder 33.

Next, a method for producing a polymer composition using such a continuous polymerization apparatus will be described. The method for producing the polymer composition is generally as follows:
The raw material monomer and the polymerization initiator are continuously supplied to the complete mixing type first reaction tank, and subjected to continuous polymerization reaction with stirring in the first reaction tank, and the intermediate composition obtained thereby is added to the first reaction tank. A first polymerization step continuously withdrawing from one reaction vessel;
The intermediate composition is connected from the first reaction tank through the connection line using a connection line that connects between the first reaction tank and the second reaction tank of the complete mixing type and includes a temperature adjusting means. Continuously supplied to the second reaction tank, and further subjected to a continuous polymerization reaction while stirring in the second reaction tank. The polymer composition obtained thereby is continuously supplied from the second reaction tank. The continuous polymerization method including the second polymerization step extracted in the method is performed.

  In this embodiment, as an example, a case where a methacrylic ester monomer is continuously polymerized, in other words, a case where a methacrylic ester polymer is produced will be described, but the present invention is not limited thereto.

-Preparation First, raw material monomers and a polymerization initiator are prepared.

In this embodiment, a methacrylic acid ester monomer is used as the raw material monomer.
Examples of methacrylic acid ester monomers include:
Alkyl methacrylate (alkyl group having 1 to 4 carbon atoms) alone, or alkyl methacrylate (alkyl group having 1 to 4 carbon atoms) 50% by mass or more, copolymerizable with this And a mixture with other vinyl monomer of 50% by mass or less. About the said mixture, the mixture of 80 mass% or more of alkyl methacrylates (thing whose carbon number of an alkyl group is 1-4) and 20 mass% or less of other vinyl monomers copolymerizable with this is preferable.
Examples of the alkyl methacrylate (the alkyl group having 1 to 4 carbon atoms) include, for example, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, and t-methacrylate. Examples thereof include butyl, sec-butyl methacrylate, and isobutyl methacrylate. Among them, methyl methacrylate is preferable. The alkyl methacrylates exemplified above may be used alone or in combination of two or more.
Examples of the copolymerizable vinyl monomer include a monofunctional monomer having one radical polymerizable double bond and a polyfunctional monomer having two or more radical polymerizable double bonds. It is done. Specifically, examples of the monofunctional monomer having one radical-polymerizable double bond include methacrylic acid esters such as benzyl methacrylate and 2-ethylhexyl methacrylate (provided that the alkyl methacrylate (alkyl Acrylic esters such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate; acrylic acid, methacrylic acid, Unsaturated carboxylic acids such as maleic acid, itaconic acid, maleic anhydride, itaconic anhydride or their anhydrides; 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, monoglycerol acrylate, 2-hydroxy methacrylate Ethyl, 2-hydroxypropyl methacrylate, methacrylate Hydroxyl group-containing monomers such as monoglycerol phosphate; nitrogen-containing monomers such as acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, diacetone acrylamide, dimethylaminoethyl methacrylate; allyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, etc. Epoxy group-containing monomers; styrene monomers such as styrene and α-methylstyrene. Examples of the polyfunctional monomer having two or more double bonds capable of radical polymerization include unsaturated carboxylic acid diesters of glycols such as ethylene glycol dimethacrylate and butanediol dimethacrylate; allyl acrylate, allyl methacrylate, Alkenyl esters of unsaturated carboxylic acids such as allyl cinnamate; polyalkenyl esters of polybasic acids such as diallyl phthalate, diallyl maleate, triallyl cyanurate, triallyl isocyanurate; multivalents such as trimethylolpropane triacrylate Unsaturated carboxylic acid ester of alcohol; divinylbenzene. The above exemplified copolymerizable vinyl monomers may be used singly or in combination of two or more.
In the present embodiment, the raw material monomer preferably contains 50% by mass or more of methyl methacrylate.

In this embodiment, for example, a radical initiator is used as the polymerization initiator.
Examples of the radical initiator include azobisisobutyronitrile, azobisdimethylvaleronitrile, azobiscyclohexanenitrile, 1,1′-azobis (1-acetoxy-1-phenylethane), dimethyl 2,2′-azo. Azo compounds such as bisisobutyrate and 4,4′-azobis-4-cyanovaleric acid; benzoyl peroxide, lauroyl peroxide, acetyl peroxide, caprylyl peroxide, 2,4-dichlorobenzoyl peroxide, isobutyl peroxide Oxide, acetylcyclohexylsulfonyl peroxide, t-butylperoxypivalate, t-butylperoxyneodecanoate, t-butylperoxyneoheptanoate, t-butylperoxy-2-ethylhexanoate, 1 , 1-Di ( -Butylperoxy) cyclohexane, 1,1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-di (t-hexylperoxy) -3,3,5-trimethylcyclohexane , Diisopropyl peroxydicarbonate, diisobutylperoxydicarbonate, di-sec-butylperoxydicarbonate, di-n-butylperoxydicarbonate, bis (2-ethylhexyl) peroxydicarbonate, bis (4-t- Butylcyclohexyl) peroxydicarbonate, t-amylperoxy-2-ethylhexanoate, 1,1,3,3-tetramethylbutylperoxy-ethylhexanoate, 1,1,2-trimethylpropylperoxy 2-ethylhexanoate, t-butyl peroxy Isopropyl monocarbonate, t-amyl peroxyisopropyl monocarbonate, t-butyl peroxy-2-ethylhexyl carbonate, t-butyl peroxyallyl carbonate, t-butyl peroxyisopropyl carbonate, 1,1,3,3-tetramethyl Butyl peroxyisopropyl monocarbonate, 1,1,2-trimethylpropyl peroxyisopropyl monocarbonate, 1,1,3,3-tetramethylbutyl peroxyisononate, 1,1,2-trimethylpropylperoxy-isononate And organic peroxides such as t-butyl peroxybenzoate.
These polymerization initiators may be used alone or in a combination of two or more.

  A polymerization initiator is selected according to the kind of polymer (polymer) to produce | generate and the raw material monomer to be used. For example, although the present invention is not particularly limited, the polymerization initiator (radical initiator) is a polymerization initiator having a half-life of τ (seconds) at the polymerization temperature and an average residence time in the reaction vessel of θ ( As the second), τ / θ (−) is, for example, 0.1 or less, preferably 0.02 or less, more preferably 0.01 or less. If the value of τ / θ is less than this value, the polymerization initiator is sufficiently decomposed (and thus generates radicals) in the reaction vessel, and the polymerization reaction can be effectively started. In addition, since the polymerization initiator is sufficiently decomposed in the first reaction vessel 10, it can be effectively reduced that the polymerization initiator is decomposed in the connection line 15 to start polymerization. It can be effectively avoided that the viscosity of the composition increases while it passes through the connection line 15 and that the connection line 15 is blocked by the intermediate composition.

  The supply amount of the polymerization initiator (radical initiator) is not particularly limited, but is usually 0.001 to 1% by mass with respect to the raw material monomer (raw material monomer finally supplied to the reaction vessel 10). It is. When the polymerization initiator tank 17 and the pump 19 are present in addition to the polymerization initiator tank 3 and the pump 7, the polymerization initiator is divided and supplied to the first reaction tank 10 and the second reaction tank 20. can do. When the mixture of the raw material monomer and the polymerization initiator is supplied from the polymerization initiator tank 17 to the second reaction tank 20 by the pump 19, the total supply amount of the polymerization initiator supplied to the reaction tank 10 and the reaction tank 20 is What is necessary is just to make it become the said range with respect to the total amount of the raw material monomer finally supplied to the reaction tank 10, and the raw material monomer newly supplied to the reaction tank 20. FIG.

  In addition to the above raw material monomers and polymerization initiator, any appropriate other components such as chain transfer agents, release agents, rubbery polymers such as butadiene and styrene butadiene rubber (SBR), heat stabilizers, ultraviolet rays Absorbents may be used. Chain transfer agents are used to adjust the molecular weight of the polymer produced. A mold release agent is used in order to improve the moldability of the resin composition obtained from a polymer composition. A heat stabilizer is used in order to suppress thermal decomposition of the produced polymer. An ultraviolet absorber is used in order to suppress deterioration by the ultraviolet-ray of the polymer to produce | generate.

  The chain transfer agent may be a monofunctional or polyfunctional chain transfer agent. Specifically, for example, n-propyl mercaptan, isopropyl mercaptan, n-butyl mercaptan, t-butyl mercaptan, n-hexyl mercaptan, n-octyl mercaptan, 2-ethylhexyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, etc. Alkyl mercaptans such as phenyl mercaptan and thiocresol; mercaptans having 18 or less carbon atoms such as ethylene thioglycol; ethylene glycol, neopentyl glycol, trimethylolpropane, pentaerythritol, dipentaerythritol, tripentaerythritol, Polyhydric alcohols such as sorbitol; hydroxyl group esterified with thioglycolic acid or 3-mercaptopropionic acid, 1,4- Tetrahydronaphthalene, 1,4,5,8-tetrahydronaphthalene, beta-terpinene, terpinolene, 1,4-cyclohexadiene, and the like hydrogen sulfide. These may be used alone or in combination of two or more.

  The supply amount of the chain transfer agent is not particularly limited because it varies depending on the type of chain transfer agent used. For example, when mercaptans are used, the raw material monomer (finally the reaction tank) Is preferably 0.01 to 3% by mass, and more preferably 0.05 to 1% by mass with respect to the raw material monomer supplied to No. 10).

  The release agent is not particularly limited, and examples thereof include higher fatty acid esters, higher aliphatic alcohols, higher fatty acids, higher fatty acid amides, and higher fatty acid metal salts. In addition, only 1 type may be sufficient as a mold release agent, and 2 or more types may be sufficient as it.

  Specific examples of the higher fatty acid ester include, for example, methyl laurate, ethyl laurate, propyl laurate, butyl laurate, octyl laurate, methyl palmitate, ethyl palmitate, propyl palmitate, butyl palmitate, palmitate Octyl acid, methyl stearate, ethyl stearate, propyl stearate, butyl stearate, octyl stearate, stearyl stearate, myristyl myristate, methyl behenate, ethyl behenate, propyl behenate, butyl behenate, octyl behenate Saturated fatty acid alkyl esters such as methyl oleate, ethyl oleate, propyl oleate, butyl oleate, octyl oleate, methyl linoleate, ethyl linoleate, propyl linoleate, Unsaturated fatty acid alkyl esters such as butyl acrylate and octyl linoleate; lauric acid monoglyceride, lauric acid diglyceride, lauric acid triglyceride, palmitic acid monoglyceride, palmitic acid diglyceride, palmitic acid triglyceride, stearic acid monoglyceride, stearic acid diglyceride, stearic acid Saturated fatty acid glycerides such as triglyceride, behenic acid monoglyceride, behenic acid diglyceride, behenic acid triglyceride; unsaturated fatty acid glycerides such as oleic acid monoglyceride, oleic acid diglyceride, oleic acid triglyceride, linoleic acid monoglyceride, linoleic acid diglyceride, linoleic acid triglyceride It is done. Among these, methyl stearate, ethyl stearate, butyl stearate, octyl stearate, stearic acid monoglyceride, stearic acid diglyceride, stearic acid triglyceride and the like are preferable.

  Specific examples of the higher aliphatic alcohol include saturated aliphatic alcohols such as lauryl alcohol, palmityl alcohol, stearyl alcohol, isostearyl alcohol, behenyl alcohol, myristyl alcohol, cetyl alcohol; oleyl alcohol, linolyl alcohol, and the like. Examples include unsaturated fatty alcohols. Of these, stearyl alcohol is preferred.

  Specific examples of higher fatty acids include, for example, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, and 12-hydroxyoctadecanoic acid. Fatty acids; unsaturated fatty acids such as palmitoleic acid, oleic acid, linoleic acid, linolenic acid, cetreic acid, erucic acid, ricinoleic acid and the like.

  Specific examples of the higher fatty acid amide include saturated fatty acid amides such as lauric acid amide, palmitic acid amide, stearic acid amide, and behenic acid amide; unsaturated fatty acid amides such as oleic acid amide, linoleic acid amide, and erucic acid amide. Amides; Amides such as ethylene bislauric acid amide, ethylene bispalmitic acid amide, ethylene bisstearic acid amide, and N-oleyl stearamide. Of these, stearic acid amide and ethylenebisstearic acid amide are preferable.

  Examples of the higher fatty acid metal salt include sodium salts, potassium salts, calcium salts and barium salts of the higher fatty acids described above.

  It is preferable to adjust the usage-amount of a mold release agent so that it may become 0.01-1.0 mass part with respect to 100 mass parts of polymers (polymer) contained in the polymer composition obtained. It is more preferable to adjust so that it may become 01-0.50 mass part.

  The heat stabilizer is not particularly limited, and examples thereof include phosphorus heat stabilizers and organic disulfide compounds. Of these, organic disulfide compounds are preferred. In addition, only 1 type may be sufficient as a heat stabilizer, and 2 or more types may be sufficient as it.

  Examples of the phosphorus-based heat stabilizer include tris (2,4-di-t-butylphenyl) phosphite, 2-[[2,4,8,10-tetrakis (1,1-dimethylethyl) dibenzo [d. , F] [1,3,2] dioxaphosphin-6-yl] oxy] -N, N-bis [2-[[2,4,8,10-tetrakis (1,1-dimethylethyl) Dibenzo [d, f] [1,3,2] dioxaphosphin-6-yl] oxy] -ethyl] ethanamine, diphenyltridecyl phosphite, triphenyl phosphite, 2,2-methylenebis (4,6 -Di-tert-butylphenyl) octyl phosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, and the like. Among these, 2,2-methylenebis (4,6-di-tert-butylphenyl) octyl phosphite is preferable.

  Examples of the organic disulfide compound include dimethyl disulfide, diethyl disulfide, di-n-propyl disulfide, di-n-butyl disulfide, di-sec-butyl disulfide, di-tert-butyl disulfide, di-tert-amyl disulfide, and dicyclohexyl. Examples thereof include disulfide, di-tert-octyl disulfide, di-n-dodecyl disulfide, di-tert-dodecyl disulfide and the like. Among these, di-tert-alkyl disulfide is preferable, and di-tert-dodecyl disulfide is more preferable.

  It is preferable that the usage-amount of a heat stabilizer is 1-2000 mass ppm with respect to the polymer (polymer) contained in the polymer composition obtained. When molding a polymer composition (more specifically, a resin composition after devolatilization) in order to obtain a molded body from the polymer composition of the present invention, the molding temperature is set high for the purpose of increasing molding efficiency. In such a case, it is more effective to add a heat stabilizer.

  Examples of the ultraviolet absorber include benzophenone ultraviolet absorbers, cyanoacrylate ultraviolet absorbers, benzotriazole ultraviolet absorbers, malonic ester ultraviolet absorbers, and oxalanilide ultraviolet absorbers. An ultraviolet absorber may be used independently and may be used in combination of 2 or more type. Among these, benzotriazole type ultraviolet absorbers, malonic acid ester type ultraviolet absorbers, and oxalanilide type ultraviolet absorbers are preferable.

  Examples of the benzophenone-based UV absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, 2-hydroxy-4-octyloxybenzophenone, Examples include 4-dodecyloxy-2-hydroxybenzophenone, 4-benzyloxy-2-hydroxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone.

  Examples of the cyanoacrylate ultraviolet absorber include ethyl 2-cyano-3,3-diphenylacrylate, 2-ethylhexyl 2-cyano-3,3-diphenylacrylate, and the like.

  Examples of the benzotriazole ultraviolet absorber include 2- (2-hydroxy-5-methylphenyl) -2H-benzotriazole and 5-chloro-2- (3,5-di-t-butyl-2-hydroxyphenyl). ) -2H-benzotriazole, 2- (3-t-butyl-2-hydroxy-5-methylphenyl) -5-chloro-2H-benzotriazole, 2- (3,5-di-t-pentyl-2- Hydroxyphenyl) -2H-benzotriazole, 2- (3,5-di-tert-butyl-2-hydroxyphenyl) -2H-benzotriazole, 2- (2H-benzotriazol-2-yl) -4-methyl- 6- (3,4,5,6-tetrahydrophthalimidylmethyl) phenol, 2- (2-hydroxy-5-t-octylphenyl) -2H-benzoto Azoles and the like.

  As the malonic acid ester ultraviolet absorber, 2- (1-arylalkylidene) malonic acid esters are usually used, and examples thereof include 2- (paramethoxybenzylidene) malonic acid dimethyl.

  As the oxalanilide ultraviolet absorber, 2-alkoxy-2'-alkyloxalanilides are usually used, and examples thereof include 2-ethoxy-2'-ethyloxalanilide.

  It is preferable that the usage-amount of a ultraviolet absorber is 5-1000 mass ppm with respect to the polymer (polymer) contained in the polymer composition obtained.

  In the raw material monomer tank 1, the above raw material monomers (one kind or a mixture of two or more kinds) are appropriately mixed (optionally together with other components such as a chain transfer agent). Further, in the polymerization initiator tank 3, the polymerization initiator as described above is appropriately mixed with the raw material monomer (and optionally other components such as a chain transfer agent) as necessary. The polymerization initiator tank 3 may store the polymerization initiator alone or in the form of a mixture of the raw material monomer and the polymerization initiator (which may further include other components such as a chain transfer agent in some cases). May be. In the case where the polymerization initiator tank 17 is used, in the polymerization initiator tank 17, the polymerization initiator as described above is appropriately mixed with the raw material monomer (optionally together with other components such as a chain transfer agent) as necessary. The polymerization initiator tank 17 may store the polymerization initiator alone or in the form of a mixture of the raw material monomer and the polymerization initiator (which may further include other components such as a chain transfer agent in some cases). May be. However, when the supply port 21c is connected to the polymerization initiator tank 17 via the pump 19, if the polymerization initiator is stored alone, the polymerization initiator is supplied to the reaction tank 20 alone, so that the reaction tank 20 There is a possibility that the polymerization reaction proceeds locally. On the other hand, if it stores in the form of the mixture of a raw material monomer and a polymerization initiator, since the polymerization initiator is previously mixed with a part of raw material monomer, this possibility may be eliminated.

First polymerization step From the raw material monomer tank 1 and the polymerization initiator tank 3 which are supply sources of the raw material monomer and the polymerization initiator, the raw material monomer and the polymerization initiator are continuously supplied to the first reaction tank 10 from the supply port 11a. Supply. Specifically, the raw material monomer is supplied from the raw material monomer tank 1 by the pump 5 and the polymerization initiator tank 3 is supplied with a polymerization initiator (preferably a mixture of the raw material monomer and the polymerization initiator, simply referred to as a polymerization initiator in this specification). Are fed together through the raw material supply line 9 by the pump 7 and continuously supplied to the first reaction tank 10 from the supply port 11a. Alternatively, the polymerization initiator may be supplied from the polymerization initiator tank 3 to the first reaction tank 10 from the supply port 11c by the pump 7 as shown by a dotted line in FIG.

  In the supply of the polymerization initiator to the first reaction tank 10, when a mixture of the raw material monomer and the polymerization initiator is prepared and supplied to the polymerization initiator tank 3, the supply flow rate A of the raw material monomer from the raw material monomer tank 1 (Kg / h) and a feed flow rate B (kg / h) of a mixture of the raw material monomer from the polymerization initiator tank 3 and the polymerization initiator (the content of the polymerization initiator is 0.002 to 10% by mass). The ratio A: B to h) is preferably adjusted to be in the range of 80:20 to 98: 2.

  The temperature of the raw material monomer and the polymerization initiator supplied to the first reaction tank 10 is not particularly limited, but it causes the heat balance in the reaction tank to be lost and the polymerization temperature to fluctuate. For this reason, it is preferable to adjust the temperature appropriately before being supplied to the reaction vessel 10 by a heating / cooling device (not shown).

  The raw material monomer and the polymerization initiator supplied to the first reaction tank 10 as described above are continuously polymerized in this embodiment while being stirred by the stirrer 14 (in other words, there is no solvent). Polymerization). The first polymerization step only needs to allow the polymerization reaction to proceed halfway, and the intermediate composition is continuously extracted from the extraction port 11b of the first reaction vessel 10.

  In the first polymerization step, the continuous polymerization may be performed in a state where the reaction vessel is filled with the reaction mixture and substantially no gas phase exists (hereinafter referred to as “full solution state”). This is particularly suitable for continuous bulk polymerization. Due to this full liquid state, there is a problem that the gel adheres to the inner wall surface of the reaction vessel and grows, and a problem that the quality of the finally obtained polymer composition is deteriorated when this gel is mixed into the reaction mixture. Can be prevented in advance. Furthermore, this full liquid state can effectively utilize the entire volume of the reaction tank in the reaction space, and thus high production efficiency can be obtained.

  The full liquid state is simple by simply supplying and extracting the first reaction tank 10 continuously by positioning the extraction port 11b of the first reaction tank 10 at the top of the reaction tank as in this embodiment. Can be realized. The position of the outlet at the top of the reaction vessel is particularly suitable for continuous polymerization of methacrylic acid ester monomers.

  In the first polymerization step, the continuous polymerization can be carried out in an adiabatic state (a state in which there is substantially no heat entering / exiting from the outside of the reaction vessel). This is particularly suitable for continuous bulk polymerization. Due to this heat insulation state, there is a problem that the gel adheres to the inner wall surface of the reaction vessel and grows, and a problem that the quality of the finally obtained polymer composition is deteriorated when this gel is mixed into the reaction mixture. Occurrence can be prevented in advance. Furthermore, this adiabatic state can stabilize the polymerization reaction and can provide self-controllability for suppressing the runaway reaction.

The heat insulation state can be realized by making the temperature T ₁ inside the first reaction tank 10 and the temperature of the outer wall surface thereof substantially equal. Specifically, using the above-described control means (not shown), the temperature of the outer wall surface of the first reaction tank 10 set for the jacket (temperature adjustment means) 13 and the temperature sensor (temperature detection means). ) Adjust the operation of the pumps 5 and 7 so that the raw material monomer and the polymerization initiator are supplied to the first reaction tank 10 so that the temperature T ₁ in the first reaction tank 10 detected by T matches. It can be realized by doing. If the temperature of the outer wall surface of the reaction tank is set too high compared to the temperature in the reaction tank, it is not preferable because extra heat is applied to the reaction tank. It is preferable that the temperature difference between the inside of the reaction tank and the outer wall surface of the reaction tank is as small as possible.

  The polymerization heat and heat of stirring generated in the first reaction tank 10 are usually carried away when the intermediate composition is extracted from the first reaction tank 10. The amount of heat that the intermediate composition takes away is determined by the flow rate of the intermediate composition, the specific heat, and the temperature of the polymerization reaction.

The temperature of continuous polymerization in the first polymerization step is understood as the temperature T ₁ (detected by the temperature sensor T) in the first reaction vessel 10. The first polymerization step is performed, for example, at a temperature within the range of 120 to 170 ° C, preferably at a temperature within the range of 125 to 160 ° C. However, it should be noted that the temperature in the reaction vessel may vary depending on various conditions until a steady state is reached.

The pressure of continuous polymerization in the first polymerization step is understood as the pressure P ₁ in the first reaction vessel 10. This pressure is set to a pressure equal to or higher than the vapor pressure of the raw material monomer at the temperature T ₁ in the reaction vessel so that no gas of the raw material monomer is generated in the reaction vessel. Usually, the gauge pressure is about 1.0 to 2.0 MPa. It is.

  The time given to the continuous polymerization in the first polymerization step is understood as the average residence time of the first reaction vessel 10. The average residence time in the first reaction vessel 10 can be set according to the production efficiency of the polymer in the intermediate composition and is not particularly limited, and is, for example, 15 minutes to 6 hours. The average residence time in the first reaction tank 10 can be adjusted by changing the supply amount (supply flow rate) of the raw material monomer and the like to the first reaction tank 10 using the pumps 5 and 7, but the first reaction Since it largely depends on the volume of the tank 10, it is important how to design the volume of the first reaction tank 10 and the volume of the second reaction tank 20 as described later.

  As described above, the intermediate composition is continuously extracted from the extraction port 11 b of the first reaction tank 10. The obtained intermediate composition contains the produced polymer and unreacted raw material monomers, and may further contain an unreacted polymerization initiator, a polymerization initiator decomposition product, and the like.

  Although the polymerization rate in an intermediate composition does not limit this embodiment, it is 5-80 mass%, for example. The polymerization rate in the intermediate composition generally corresponds to the polymer (polymer) content in the intermediate composition.

Transfer step The intermediate composition obtained as described above is continuously extracted from the extraction port 11b of the first reaction tank 10 and then to the supply port 21a of the second reaction tank 20 through the connection line 15. Supplied.

  While the intermediate composition passes through the connection line 15, the temperature of the intermediate composition may be continuously adjusted by the jacket 16 or the heating / cooling device 40 which is a temperature adjusting means provided in the connection line 15. As described above, when the supply temperature of the intermediate composition to the second reaction tank 20 is adjusted using the jacket 16 or the heating / cooling device 40 provided as the temperature adjusting means in the connection line 15, the supply temperature is kept substantially constant. Therefore, continuous polymerization in the second polymerization step can be performed more stably.

For example, the temperature in the connection line 15 (typically, the set temperature T _m of the temperature adjusting means of the connection line 15) is substantially the same as the temperature T ₁ in the first reaction vessel 10. The temperature of the intermediate composition passing through the connection line 15 may be adjusted by the jacket 16 or the heating / cooling device 40. By preventing the temperature in the connection line 15 from becoming too high with respect to the temperature in the first reaction tank 10, the temperature in the second reaction tank 20 is prevented from rising, and finally Quality such as thermal stability of the obtained resin composition can be maintained.

Further, for example, the intermediate composition passing through the connection line 15 so that the temperature in the connection line 15 in the vicinity of the supply port 21 a of the second reaction tank 20 is lower than the temperature T ₁ in the first reaction tank 10. The temperature may be adjusted (in this case, cooling) by the jacket 16 or the heating / cooling device 40. The degree of cooling may vary depending on the difference between the temperature in the first reaction tank 10 and the temperature in the second reaction tank 20 as in the above preferred control example, and the desired degree in the second reaction tank 20. Specifically, the temperature of the intermediate composition in the supply port 21a of the second reaction tank 20 is adjusted according to the polymerization temperature and the polymerization rate of the intermediate composition. For example, the temperature may be 5 to 80 ° C. lower than the temperature of the object. Even if heat of polymerization is generated in the second reaction tank 20 by cooling, continuous polymerization is performed while avoiding the occurrence of a temperature non-uniform state in the second reaction tank 20, and the second reaction It is possible to achieve a high polymerization rate while keeping the temperature in the tank 20 low, that is, to increase the productivity of the polymer, and as a result, to efficiently obtain a polymer excellent in thermal stability and heat resistance. Can do.

  In addition, although not essential to the present invention, it is preferable to provide a mixing means in the connection line 15. By providing the mixing means, the intermediate composition flowing in the connection line 15 is uniformly mixed, the temperature distribution is likely to be uniform, and blockage of the connection line 15 by the intermediate composition can be suppressed. When the mixing means is provided in the connection line 15, a static mixer or a dynamic mixer may be provided in the connection line 15, or the heating / cooling device 40 having both the mixing means and the temperature adjusting means may be provided in the connection line 15. Good.

-2nd superposition | polymerization process A 2nd superposition | polymerization process is implemented in series after a 1st superposition | polymerization process.
The intermediate composition transferred through the connection line 15 as described above is continuously supplied to the second reaction tank 20 from the supply port 21a. The intermediate composition is further subjected to continuous polymerization while being stirred by the stirrer 24 in the second reaction tank 20, and in this embodiment, continuous bulk polymerization. In the second polymerization step, the polymerization reaction is advanced to a desired polymerization rate, and the polymer composition (or polymerization syrup) is continuously extracted from the extraction port 21b of the second reaction tank 20.

  Hereinafter, the second polymerization step will be described with a focus on differences from the first polymerization step, and the same description as the first polymerization step will be applied unless otherwise specified.

  Although not essential to the present invention, it is preferable to use a polymerization initiator tank 17 and a pump 19. When the polymerization initiator tank 17 and the pump 19 are used, a new polymerization initiator (preferably a mixture of raw material monomers and polymerization initiator) is connected from the polymerization initiator tank 17 to the second reaction tank 20 by the pump 19. It supplies from the supply port 21a through the line 15, or another supply port 21c, and, thereby, a new polymerization initiator is added to an intermediate composition. The temperature of the polymerization initiator supplied from the polymerization initiator tank 17 to the second reaction tank 20 is not particularly limited, but is a factor that causes the polymerization temperature to fluctuate by breaking the heat balance in the reaction tank. Therefore, it is preferable to adjust the temperature appropriately before being supplied to the reaction vessel 20 by a heating / cooling device (not shown).

In the supply of the polymerization initiator to the second reaction tank 20, when the mixture of the raw material monomer and the polymerization initiator is prepared and supplied to the polymerization initiator tanks 3 and 17, the raw material monomer is supplied from the raw material monomer tank 1. Supply flow rate B _{1 of the} flow rate A (kg / h) and a mixture of the raw material monomer and the polymerization initiator from the polymerization initiator tank 3 (the content of the polymerization initiator is 0.002 to 10% by mass). (Kg / h) and a feed flow rate B ₂ (kg) of a mixture of the raw material monomer and the polymerization initiator from the polymerization initiator tank 17 (the content of the polymerization initiator is 0.002 to 10% by mass). / H) so that the ratio A: (B ₁ + B ₂ ) is in the range of 80:20 to 98: 2, and the ratio B ₁ : B ₂ is in the range of 10:90 to 90:10. It is preferable to adjust.

  Also in the second polymerization step, continuous polymerization can be performed in a full liquid state. This is particularly suitable for continuous bulk polymerization. Due to this full liquid state, there is a problem that the gel adheres to the inner wall surface of the reaction vessel and grows, and a problem that the quality of the finally obtained polymer composition is deteriorated when this gel is mixed into the reaction mixture. Can be prevented in advance. Furthermore, this full liquid state can effectively utilize the entire volume of the reaction tank in the reaction space, and thus high production efficiency can be obtained.

  The full liquid state is simple by simply supplying and extracting the second reaction tank 20 continuously by positioning the extraction port 21b of the second reaction tank 20 at the top of the reaction tank as in this embodiment. Can be realized. The position of the outlet at the top of the reaction vessel is particularly suitable for continuous polymerization of methacrylic acid ester monomers.

  Also in the second polymerization step, continuous polymerization can be carried out in an adiabatic state. This is particularly suitable for continuous bulk polymerization. Due to this heat insulation state, there is a problem that the gel adheres to the inner wall surface of the reaction vessel and grows, and a problem that the quality of the finally obtained polymer composition is deteriorated when this gel is mixed into the reaction mixture. Occurrence can be prevented in advance. Furthermore, this adiabatic state can stabilize the polymerization reaction and can provide self-controllability for suppressing the runaway reaction.

Adiabatic conditions, a temperature T ₂ within the second reaction vessel 20 can be realized by substantially equal the temperature of its outer wall surface. Specifically, using the above-described control means (not shown), the temperature of the outer wall surface of the second reaction tank 20 set for the jacket (temperature adjusting means) 23 and the temperature sensor (temperature detecting means). ) When supply amounts of the raw material monomer and the polymerization initiator to the second reaction tank 20 are the pumps 5 and 7 and the temperature T ₂ in the second reaction tank 20 detected by T are equal to each other. This can be realized by adjusting the operation of the pump 19. If the temperature of the outer wall surface of the reaction tank is set too high compared to the temperature in the reaction tank, it is not preferable because extra heat is applied to the reaction tank. It is preferable that the temperature difference between the inside of the reaction tank and the outer wall surface of the reaction tank is as small as possible.

  The heat of polymerization and heat of stirring generated in the second reaction tank 20 are usually carried away when the polymer composition is extracted from the second reaction tank 20. The amount of heat carried away by the polymer composition is determined by the flow rate of the polymer composition, the specific heat, and the temperature of the polymerization reaction.

The temperature of continuous polymerization in the second polymerization step is understood as the temperature T ₂ in the second reaction vessel 20. The second polymerization step is performed, for example, at a temperature within the range of 130 to 200 ° C, preferably at a temperature within the range of 130 to 180 ° C.

The continuous polymerization pressure in the second polymerization step is understood as the pressure P ₂ in the second reaction vessel 20. This pressure is usually about 1.0 to 2.0 MPa in gauge pressure, and may be equal to the pressure in the first polymerization step.

  The time subjected to continuous polymerization in the second polymerization step is understood as the average residence time of the second reaction vessel 20. The average residence time in the second reaction tank 20 can be set according to the production efficiency of the polymer in the polymer composition and is not particularly limited, but is, for example, 15 minutes to 6 hours. The ratio of the average residence time in the second reaction tank 20 to the average residence time in the first reaction tank 10 is preferably 9/1 to 1/9, more preferably 8/2 to 2/8. . The average residence time in the second polymerization step may be equivalent to the average residence time in the first polymerization step, but is preferably different from that. The average residence time in the second reaction tank 20 is obtained by changing the supply amount (supply flow rate) of the raw material monomer or the like to the second reaction tank 20 using the pumps 5 and 7 and, if present, the pump 19. Although it can be adjusted, since it greatly depends on the volume of the second reaction vessel 20, it is important how to design the volume of the first reaction vessel 10 and the volume of the second reaction vessel 20 as described later. is there.

  As described above, the polymer composition is continuously extracted from the extraction port 21 b of the second reaction tank 20. The obtained polymer composition comprises the produced polymer, and may further contain unreacted raw material monomers, unreacted polymerization initiator, polymerization initiator decomposition product, and the like.

  Although the polymerization rate in a polymer composition does not limit this embodiment, it is 30-90 mass%, for example. The polymerization rate in the polymer composition generally corresponds to the polymer (polymer) content in the polymer composition. The higher the polymerization rate, the higher the polymer productivity, but the higher the viscosity of the intermediate composition to the polymer composition, and the larger the stirring power is required. Further, the lower the polymerization rate, the lower the productivity of the polymer and the greater the burden for recovering unreacted raw material monomers. Therefore, it is preferable to set an appropriate polymerization rate as a target or a guide.

  How to set the polymerization reaction conditions in each of the first polymerization step and the second polymerization step depends on the polymer to be produced, the raw material monomers to be used and the polymerization initiator, the desired heat resistance, thermal stability and It can vary depending on production efficiency.

  As described above, a polymer composition is produced using the above-described continuous polymerization apparatus. The polymer composition thus obtained can be subjected to a devolatilization treatment and pelletized by the preheater 31 and the devolatilization extruder 33 arranged downstream of the continuous polymerization apparatus as follows.

-Volatilization step As described above, the polymer composition (polymerization syrup) extracted from the extraction port 21b of the second reaction tank 20 is not only the produced polymer but also the unreacted raw material monomer and the polymerization initiator. And so on. Such a polymer composition does not limit the present embodiment, but it is preferable to separate and recover the raw material monomer through devolatilization or the like.

  Specifically, the polymer composition is transferred to the preheater 31 through the extraction line 25. In the preheater 31, the polymer composition is given a part or all of the amount of heat necessary for volatilization of volatile components mainly composed of unreacted raw material monomers. The polymer composition is then transferred to a devolatilizing extruder 33 via a pressure regulating valve (not shown), where volatile components are at least partially removed in the devolatilizing extruder, and the remaining extrudate is It is formed into a pellet and taken out from the take-out line 35. Thereby, the resin composition containing a methacrylic ester polymer is produced in the form of pellets.

  As a method for transferring the polymer composition, the method described in JP-B-4-48802 is suitable. Examples of methods using a devolatilizing extruder include, for example, JP-A-3-49925, JP-B-51-29914, JP-B-52-17555, JP-B-1-53682, JP-A-62. The method described in JP-A-89710 is suitable.

  Further, when devolatilizing and extruding the polymer composition with the above devolatilizing extruder, or after that, if necessary, lubricants such as higher alcohols and higher fatty acid esters, ultraviolet absorbers, heat stabilizers. Colorants, antistatic agents, etc. can be added to the polymer composition or extrudate and included in the resin composition.

  Volatile components removed by the devolatilizing extruder 33 are mainly composed of unreacted raw material monomers, impurities originally contained in the raw material monomers, additives used as necessary, and volatile by-products generated in the polymerization process. It comprises impurities such as products, oligomers such as dimers and trimers, polymerization initiator decomposition products, and the like. Generally, an increase in the amount of impurities is not preferable because the resulting resin composition is colored. Therefore, the volatile component removed by the devolatilizing extruder 33 (consisting of unreacted raw material monomer as a main component and including impurities as described above) is passed through a monomer recovery tower (not shown), and the monomer It may be treated by means such as distillation or adsorption in a recovery tower, and impurities may be removed from the volatile components, whereby unreacted raw material monomer can be recovered with high purity, and as a raw material monomer for polymerization It can be suitably reused. For example, in the monomer recovery tower, unreacted raw material monomer is recovered with high purity as a distillate from the top of the monomer recovery tower by continuous distillation, stored in the recovery tank 37, and then transferred to the raw material monomer tank 1. May be recycled, or may be transferred to the raw material monomer tank 1 for recycling without being stored in the recovery tank 37. On the other hand, impurities removed in the monomer recovery tower can be discarded as waste.

  In order to prevent the polymerization reaction from proceeding in the recovery tank 37 or the raw material monomer tank 1, the recovered raw material monomer is added with a polymerization inhibitor in the recovery tank 37 or the raw material monomer tank 1, for example 2 It is preferable to make it exist in the ratio of 8 mass ppm, and in addition, it is more preferable when the oxygen concentration of the gas phase part of the recovery tank 37 and the raw material monomer tank 1 is set to 2-8 volume%. Further, when it is desired to store in the recovery tank 37 for a long period of time, it is desirable to store at a low temperature of, for example, 0 to 5 ° C.

  Next, the operation method of the continuous polymerization apparatus of this invention is demonstrated.

  As described above, a pellet-shaped resin composition is produced. For example, in the devices such as the preheater 31 and the devolatilizing extruder 33 downstream of the continuous polymerization apparatus, inspection and inspection are performed due to regular maintenance or occurrence of trouble. When performing repair work, it is necessary to stop the continuous polymerization in the continuous polymerization apparatus. In response to such a request, the continuous polymerization apparatus is operated so as to stop the continuous polymerization and maintain the stopped state from the state in which the continuous polymerization method is performed using the continuous polymerization apparatus. Therefore, the operation method of the continuous polymerization apparatus of the present invention is understood as the operation method of the continuous polymerization apparatus while the continuous polymerization is stopped (more specifically, while the stop of the polymerization reaction is intended). More specifically, the continuous polymerization apparatus is operated as follows.

  In the state in which the continuous polymerization method is carried out using the continuous polymerization apparatus, as described above, the polymerization initiator is supplied from the polymerization initiator tank 3 to the first reaction tank 10 through the supply port 11a and possibly the supply port 11c. When the polymerization initiator tank 17 and the pump 19 are present continuously, newer than the supply port 21 a and / or the supply port 21 c from the polymerization initiator tank 17 to the second reaction tank 20. A polymerization initiator is continuously supplied. In stopping the continuous polymerization, the supply of the polymerization initiator to the first reaction tank 10 and possibly the second reaction tank 20 is stopped. The supply of the polymerization initiator may be stopped, for example, by simply stopping the operation of the pump 7 and, if present, the pump 19. However, in order to prevent the piping leading from the polymerization initiator tank 3 to the first reaction tank 10 and, if present, the piping leading from the polymerization initiator tank 17 to the second reaction tank 20 from being blocked, It is preferable to supply the raw material monomer from the polymerization initiator tank 3 and the polymerization initiator tank 17 when present, to the first reaction tank 10 and the second reaction tank 20, respectively, instead of the polymerization initiator. In this way, by supplying the raw material monomer instead of the polymerization initiator, even if the continuous polymerization is stopped for a long time, blockage of the pipe can be prevented, so that the continuous polymerization can be resumed smoothly. Can do. The supply flow rate of the raw material monomer is sufficient to prevent blockage of the piping, and can be adjusted by controlling the operation of the pump 7 and, if present, the pump 19.

  In the state where the continuous polymerization method is carried out using the continuous polymerization apparatus, the raw material monomer is continuously supplied from the raw material monomer tank 1 to the first reaction tank 10 through the supply port 11a. In stopping the process, the supply of the raw material monomer is continued without stopping. Specifically, the raw material monomer is continuously supplied from the raw material monomer tank 1 to the first reaction tank 10 while the pump 5 is operated. However, the supply flow rate of the raw material monomer may be lowered to the extent that it is possible to prevent the reaction tanks 10, 20 located downstream from the raw material monomer tank 1 and the outlet / outlet piping of these reaction tanks from being blocked, and the operation of the pump 5 is controlled. It is adjustable by doing.

  In the above operation, the raw material monomers supplied to the first reaction vessel 10 and possibly the second reaction vessel 20 are usually the same as the raw material monomers used during continuous polymerization, but are different. Also good. In this embodiment, the methacrylic acid ester monomer described above is used as a raw material monomer, and the raw material monomer preferably contains 50% by mass or more of methyl methacrylate. The raw material monomer may be supplied to the first reaction vessel 10 and optionally the second reaction vessel 20 alone, but other components other than the polymerization initiator, for example, chain transfer as described above. It may be supplied together with an agent, a release agent, a rubbery polymer and the like.

  Stirring by the stirrer 14 in the first reaction tank 10 and stirring by the stirrer 24 in the second reaction tank 20 are continued as they are.

  The raw material monomer (and other components added in some cases, the same applies hereinafter) supplied as described above are combined with the reaction mixture that can remain in the first reaction vessel 10 in the first reaction vessel 10. The raw material monomer-containing fluid is formed, and is stirred by the stirrer 14 and continuously extracted from the first reaction tank 10 as the first fluid through the extraction port 11b. In the first reaction tank 10, the supply of the polymerization initiator is stopped, so that the polymerization reaction does not proceed and is substantially stopped. In addition, the raw material monomer containing fluid in the 1st reaction tank 10 and the 1st fluid extracted from the 1st reaction tank 10 are supplied to the 1st reaction tank 10 as the stop period of continuous polymerization becomes long. It approaches the composition of the raw material monomer to be made and eventually becomes almost the same.

  The first fluid extracted from the first reaction tank 10 is continuously supplied to the fully mixed second reaction tank 20 through the connection line 15. As described above, the connection line 15 includes the jacket 16 (FIG. 1), the heating / cooling device 40 (FIG. 2), and trace piping as temperature adjusting means.

  And this 1st fluid is continuously supplied to the 2nd reaction tank 20 from the supply port 21a.

  In the second reaction tank 20, the first fluid supplied as described above includes a reaction mixture that can remain in the second reaction tank 20 and, optionally, a raw material monomer supplied from the polymerization initiator tank 17. Together, the raw material monomer-containing fluid is formed, stirred by the stirrer 24, and continuously extracted from the second reaction tank 20 as the second fluid through the extraction port 21b. In the second reaction tank 20, the supply of the polymerization initiator to the upstream first reaction tank 10 is stopped, and no new polymerization initiator is supplied to the second reaction tank 20 ( When the polymerization initiator tank 17 and the pump 19 are not present and a new polymerization initiator is not originally supplied to the second reaction tank 20, and when these are present, a new one is introduced when the continuous polymerization is stopped. The polymerization reaction does not proceed and is substantially stopped, including the case where the supply of the polymerization initiator to the second reaction vessel 20 is stopped). Note that the raw material monomer-containing fluid in the second reaction tank 20 and the second fluid extracted from the second reaction tank 20 are separated from the first reaction tank 10 and the case as the continuous polymerization stop period becomes longer. As a result, the composition of the raw material monomer supplied to the second reaction tank 20 approaches and eventually becomes substantially the same.

The temperature T ₁ and pressure P _{1 in} the first reaction tank 10 and the temperature T ₂ and pressure P _{2 in} the second reaction tank 20 do not require special control in order to stop the continuous polymerization. However, the temperature T ₁ and the pressure P ₁ in the first reaction tank 10 can gradually increase due to an increase in the stop period of the continuous polymerization and the influence of the dissolved oxygen concentration in the first reaction tank 10. On the other hand, the temperature T ₂ in the second reaction tank 20 does not vary much, but the pressure P ₂ in the second reaction tank 20 can decrease as the temperature T ₁ in the first reaction tank 10 increases. Although the present invention is not bound by any theory, this is because the polymerization reaction proceeds unintentionally in the first reaction vessel 10 (for example, because the amount of dissolved oxygen in the raw material monomer-containing fluid has increased), The temperature T ₁ in the first reaction tank 10 rises due to the heat of polymerization, and the polymer generated in the first reaction tank 10 narrows or closes the pipe line of the connection line 10, so that the first reaction tank 10 the pressure P ₁ in the 10 the pressure P ₂ in the second reaction tank 20 is believed to decrease with increasing.

Accordingly, the present in the invention, so that the pressure difference _P 1 -P ₂ of the pressure _{P 1} in the first reaction vessel 10 and the pressure _{P 2} in the second reaction tank 20 is equal to or less than 0.05MPa or more 0MPa The temperature of the first fluid passing through the connection line 15 is adjusted by the temperature adjustment means of the connection line 15. As described above, the pressure P ₁ in the first reaction vessel 10 is increased, the pressure P ₂ in the second reaction vessel 20 is lowered, if P ₁ is higher than P _2, the connecting line 15 The first fluid is heated by heating the first fluid passing through the connection line 15 using the jacket 16 (FIG. 1), the heating / cooling device 40 (FIG. 2), the trace piping, etc. Thus, the pressure difference P ₁ -P ₂ can be maintained at 0 MPa or more and 0.05 MPa or less. If the pressure difference P ₁ -P ₂ is 0 MPa or more and 0.05 MPa or less, the pipe line of the connection line 15 can be effectively prevented from being narrowed or blocked, and if it is 0 MPa or more and 0.03 MPa or less, it is more effective. Can be prevented.

Specifically, when the pressure difference P ₁ -P ₂ is 0 MPa or more and 0.05 MPa or less, the heating condition is appropriately set, but the temperature T ₁ in the first reaction tank 10 and the temperature of the connection line 15 are set. The set temperature T of the jacket 16 or the heating / cooling device 40 provided as the temperature adjusting means in the connection line 15 in a range where the temperature difference T _m -T ₁ with respect to the setting temperature T _m of the adjusting means is 10 ° C. or more and 60 ° C. or less. _It is preferable to adjust _m . However, the set temperature T _m of a temperature adjusting means is preferably set in the range of 200 ° C. or less. The temperature difference T _m −T ₁ is preferably 30 ° C. or more and 50 ° C. or less.

Although not limiting the present invention, the pressure P ₁ in the first reaction vessel 10 is, for example, 1.0 to 2.0 MPa, preferably 1.3 to ₁ in gauge pressure during the stop period of the continuous polymerization. 0.7 MPa, and the temperature T ₁ in the first reaction tank 10 is, for example, 120 to 170 ° C., preferably 125 to 160 ° C. The pressure P ₂ in the second reaction tank 20 is, for example, 1.0 to 2.0 MPa, preferably 1.3 to 1.7 MPa as a gauge pressure, and a pressure difference P ₁ −P ₂ = 0 MPa or more. The temperature T2 in the _second reaction tank 20 is not higher than 0.05 MPa and is, for example, 120 to 200 ° C, preferably 130 to 180 ° C.

  The average residence time of the first reaction tank 10 and the second reaction tank 20 may vary depending on the volume of each reaction tank and the supply amount (supply flow rate) of the raw material monomer.

  As described above, the continuous polymerization performed in the continuous polymerization apparatus can be stopped and the stopped state can be maintained. Since the second fluid continuously withdrawn from the second reaction tank 20 during the continuous polymerization stop period contains the raw material monomer, it can be recovered from the extraction line 25 and reused as necessary. it can.

According to the present embodiment, the pressure P ₁ in the first reaction tank 10 and the second reaction tank are simply adjusted by adjusting the temperature of the first fluid passing through the connection line 15 by the temperature adjusting means of the connection line 15. 20 so that the pressure difference P ₁ -P ₂ with respect to the pressure P ₂ within 20 can be controlled to be 0 MPa or more and 0.05 MPa or less, so that even if the continuous polymerization is stopped for a relatively long time, the connecting line It is possible to effectively prevent the 15 pipelines from being narrowed or blocked, and to smoothly stop and restart the continuous polymerization.

  In the present embodiment, the continuous bulk polymerization apparatus in which both the first reaction tank and the second reaction tank are used to perform continuous bulk polymerization has been described. However, the continuous polymerization apparatus of this invention is not limited to this, One or both of a 1st reaction tank and a 2nd reaction tank may be used in order to implement continuous solution polymerization. In such an embodiment, since a solvent is used for solution polymerization, the continuous polymerization apparatus has the same configuration as the continuous polymerization apparatus described above with reference to FIGS. In order to supply the solvent to the reaction tank, a solvent tank and a supply line and a pump (supply means) associated therewith are further provided. These solvent tanks and the supply lines and pumps (supply means) associated therewith are not particularly limited, and those similar to those conventionally used can be used. The solvent may be supplied to a predetermined reaction vessel in which solution polymerization is performed after being mixed with a raw material monomer and / or a polymerization initiator, or may be directly supplied to a predetermined reaction vessel in which solution polymerization is performed. In the predetermined reaction vessel, the polymerization step is performed in the same manner as the polymerization step described above with reference to FIGS. 1 and 2 except that a solvent is used for the polymerization reaction. The solvent is appropriately set according to the raw material monomer of the solution polymerization reaction and is not particularly limited. For example, toluene, xylene, ethylbenzene, methyl isobutyl ketone, methyl alcohol, ethyl alcohol, Examples include octane, decane, cyclohexane, decalin, butyl acetate, and pentyl acetate. The ratio C: D of the feed flow rate C (kg / h) of the raw material monomer to the predetermined reaction tank for carrying out the solution polymerization and the supply flow rate D (kg / h) of the solvent to the predetermined reaction tank is Although not limited to, for example, it is 70: 30-95: 5, Preferably it is 80: 20-90: 10.

In addition, this invention is not limited to said embodiment, A various change is possible. For example, you may apply to the continuous polymerization apparatus which implements continuous polymerization in three steps or more in series using three or more reaction tanks. In this case, the pressure difference P _n −P _{n + 1} between the pressure P _n in the preceding reaction tank and the pressure P _{n + 1} in the subsequent reaction tank is set to 0 MPa or more and 0.05 MPa or less for two adjacent reaction tanks. The temperature of the fluid passing through this connection line may be adjusted by temperature adjusting means provided in the connection line connecting these reaction tanks in series, and the temperature T _n in the previous reaction tank and the previous and subsequent stages are adjusted. between the reaction vessel so that the temperature difference T _m -T _n of the set temperature T _m of a temperature adjusting means of the connecting line to be connected in series becomes 10 ° C. or higher 60 ° C. or less, the set temperature T _m of a temperature adjusting means of the connecting line You can adjust.

  Hereinafter, although the experiment example regarding the operating method of the continuous polymerization apparatus of this invention is shown, this invention is not limited to this example.

(Experimental example)
In this experimental example, schematically, continuous polymerization was performed in two stages according to the embodiment described above with reference to FIG. 1, and then the continuous polymerization was stopped. More details are as follows.

Mix 92.910 parts by weight of methyl methacrylate and 6.900 parts by weight of methyl acrylate, add 0.128 parts by weight of chain transfer agent [n-octyl mercaptan] and 0.062 parts by weight of release agent [stearyl alcohol]. Thus, a raw material monomer mixed solution 1 was prepared.
99.986 parts by mass of methyl methacrylate and 0.014 parts by mass of a polymerization initiator [t-amylperoxy-2-ethylhexanoate] were mixed to prepare a polymerization initiator mixed solution 1.
A polymerization initiator mixed solution 2 was prepared by mixing 99.994 parts by weight of methyl methacrylate and 0.006 parts by weight of a polymerization initiator [1,1-di (t-butylperoxy) cyclohexane].

  In this experimental example, the apparatus shown in FIG. 1 was used. A fully mixed reaction tank with a capacity of 13 L was used as the first reaction tank 10, and a fully mixed reaction tank with a capacity of 6 L was used as the second reaction tank 20. The raw material monomer mixed liquid 1, the polymerization initiator mixed liquid 1 and the polymerization initiator mixed liquid 2 prepared above were placed in the raw material monomer tank 1, the polymerization initiator tank 3 and the polymerization initiator tank 17, respectively.

  The raw material monomer mixed solution 1 and the polymerization initiator mixed solution 1 are respectively supplied from the raw material monomer tank 1 and the polymerization initiator tank 3 to the first reaction tank 10 through the raw material supply line 9 and the supply port located therebelow. It supplied continuously from 11a.

  The supply of the raw material monomer mixture 1 and the polymerization initiator mixture 1 to the first reaction vessel 10 has a flow rate ratio of 16.9: 1, and the average residence time in the first reaction vessel 10 is 40 minutes. It implemented so that it might become. The temperature in the first reaction tank 10 is 140 ° C., the temperature of the jacket 13 surrounding the outer wall surface of the first reaction tank 10 is 140 ° C., and continuous polymerization is performed in an adiabatic state with substantially no heat coming and going. It was. This continuous polymerization was carried out while stirring the reaction mixture with the stirrer 14 in a state where the first reaction vessel 10 was filled with the reaction mixture (mixed solution) and substantially no gas phase was present (full solution state). .

The reaction mixture in the first reaction tank 10 was continuously extracted as an intermediate composition from the extraction port 11 b located at the top of the first reaction tank 10. The extracted intermediate composition was continuously supplied to the second reaction tank 20 through the connection line 15 from the supply port 21a located therebelow. The connecting line 15 and the jacket 16 is provided surrounding the outer wall surface, in order to adjust the temperature of the fluid through the connecting line 15, the set temperature T _m of a jacket 16 and 140 ° C., was allowed to maintain the set temperature. Further, the polymerization initiator mixed liquid 2 was continuously supplied from the polymerization initiator tank 17 to the second reaction tank 20 through another supply port 21c.

  The supply of the intermediate composition and the polymerization initiator mixed solution 2 to the second reaction tank 20 was performed so that the flow rate ratio thereof was 17.9: 1. The average residence time in the second reaction tank 20 was 16 minutes. The temperature in the second reaction tank 20 is 175 ° C., the set temperature of the jacket 23 surrounding the outer wall surface of the second reaction tank 20 is set to 175 ° C., and continuous polymerization is performed in an adiabatic state with substantially no heat coming and going. went. This continuous polymerization was carried out while stirring the reaction mixture with the stirrer 24 in a state where the second reaction vessel 20 was filled with the reaction mixture (mixed solution) and substantially no gas phase was present (full solution state). .

  The reaction mixture in the second reaction tank 20 was continuously extracted as a polymer composition from an extraction port 21 b located at the top of the second reaction tank 20. The polymer composition thus obtained is extracted through a drawing line 25, heated to 200 ° C. by a preheater 31, and volatile such as unreacted raw material monomers at 240 ° C. by a vented devolatilizing extruder 33. The components were removed, and the devolatilized resin composition was extruded in a molten state. After cooling with water, the resin composition was cut and taken out from the take-out line 35 as pellets. Thereby, the resin composition was manufactured in the form of pellets.

As described above, during the continuous polymerization, the pressure P ₁ in the first reaction tank 10 changes within the range of 1.58 to 1.60 MPa as a gauge pressure, and the second reaction tank 20 the pressure _{P 2} of the inner has been at a range of 1.56~1.58MPa a gauge pressure, the pressure difference _P 1 -P ₂ is remained within the 0.02～0.04MPa.

Then, in order to stop continuous polymerization, the continuous polymerization apparatus was operated as follows.
Both the supply of the polymerization initiator mixed solution 1 from the polymerization initiator tank 3 to the first reaction vessel 10 and the supply of the polymerization initiator mixed solution 2 from the polymerization initiator tank 17 to the second reaction vessel 20 are stopped. Instead, the raw material monomer mixed solution is supplied from the polymerization initiator tank 3 to the first reaction tank 10 through the supply port 11a and from the polymerization initiator tank 17 to the second reaction tank 20 through the other supply port 21c. 1 was continuously fed at 0.06 kg / h.
Further, the output of the pump 5 was lowered, and the raw material monomer mixed solution 1 was continuously supplied from the raw material monomer tank 1 to the first reaction tank 10 through the supply port 11a at 0.29 kg / h.
Stirring by the stirrer 14 in the first reaction tank 10 and stirring by the stirrer 24 in the second reaction tank 20 were continued as they were.
The first fluid is continuously extracted from the extraction port 11b of the first reaction tank 10, continuously supplied to the second reaction tank 20 through the connection line 15, and the first fluid is extracted from the extraction port 21b of the second reaction tank 20. Two fluids were continuously extracted.

The set temperature of the jacket 13 surrounding the outer wall surface of the first reaction tank 10 is maintained at 140 ° C., the set temperature T _m of the jacket 16 provided in the connection line 15 is maintained at 140 ° C., and the second reaction tank The set temperature of the jacket 23 surrounding the outer wall surface of 20 was maintained at 175 ° C. The average residence time in the first reaction tank 10 was 2300 minutes, and the average residence time in the second reaction tank 20 was 900 minutes.

During the 24 hours after the continuous polymerization was stopped as described above, the pressure P ₁ in the first reaction vessel 10 changed within the range of 1.58 to 1.60 MPa as the gauge pressure, and the second reaction The pressure P ₂ in the tank 20 changed within the range of 1.56 to 1.58 MPa, and the pressure difference P ₁ -P ₂ changed within the range of 0.02 to 0.04 MPa.

After 24 hours of continuous polymerization was stopped, the temperature T ₁ and pressure P ₁ in the first reaction vessel 10 is gradually increased, the temperature T ₁ of the first reaction vessel 10 is 194 ° C. The pressure P ₁ in the first reaction tank 10 is 1.66 MPa in gauge pressure, the pressure P ₂ in the second reaction tank 20 is 1.48 MPa in gauge pressure, and the pressure difference P ₁ -P ₂ was 0.18 MPa. At this time, the temperature T2 in the _second reaction vessel 20 was about 182 ° C.

Therefore, when changing the setting temperature T _m of a jacket 16 of the connecting line 15 between the first reaction vessel 10 and the second reaction vessel 20 from 140 ° C. to 180 ° C., a first temperature in the reaction vessel 10 T ₁ gradually decreases, the temperature T ₁ in the first reaction tank 10 becomes about 141 ° C., the temperature difference T _m −T ₁ becomes about 39 ° C., and the pressure P in the first reaction tank 10 ₁ is 1.61 MPa in gauge pressure, pressure P ₂ in the second reaction tank 20 is 1.58 MPa in gauge pressure, and the pressure difference P ₁ -P ₂ is in the range of 0.02 to 0.04 MPa. Returned to. At this time, the temperature T ₂ in the second reaction vessel 20 was about 176 ° C.

This result, using a jacket (temperature adjusting means) 16 of the connecting line 15, adjusting the temperature of the first fluid through the connection line 15, to adjust the set temperature T _m of a jacket 16 in the above Experimental Examples Thus, it was confirmed that the pressure difference P ₁ -P ₂ could be maintained at 0.05 MPa or less. Thereby, it was possible to prevent the pipe line of the connection line 16 from being blocked.

  In addition, by allowing the raw material monomer tank 1 to flow from the raw material monomer tank 1 at the above flow rate, it was possible to prevent the reaction tanks 10 and 20 located downstream from the raw material monomer tank 1 and the outlet and outlet piping of these reaction tanks from being blocked. . In addition, by flowing the raw material monomer mixed solution 1 from the polymerization initiator tanks 3 and 17 at the above flow rate, the piping leading from the polymerization initiator tank 3 to the first reaction tank 10 and the second reaction from the polymerization initiator tank 17 are performed. It was possible to prevent the piping leading to the tank 20 from being blocked.

  The present invention can be used to produce a polymer composition suitable for obtaining a resin composition containing a methacrylic acid ester-based polymer.

1 Raw material monomer tank (source of raw material monomer)
3 Polymerization initiator tank (Supply source of polymerization initiator and optional raw material monomer)
5 Pump 7 Pump 9 Raw material supply line 10 First reaction tank 11a Supply port 11b Extraction port 11c Another supply port 13 Jacket (temperature control means)
14 Stirrer 15 Connection line 16 Jacket (temperature control means)
17 Polymerization initiator tank (new polymerization initiator and, optionally, raw monomer supply source)
19 Pump 20 Second reaction tank 21a Supply port 21b Extraction port 21c Another supply port 23 Jacket (temperature control means)
24 Stirrer 25 Extraction line 31 Preheater 33 Devolatilizing extruder 35 Extraction line 37 Collection tank 40 Heating / cooling device (temperature control means)
T Temperature sensor (temperature detection means)
P Pressure sensor (pressure detection means)

Claims (4)

Of the continuous polymerization apparatus while the continuous polymerization is stopped in the continuous polymerization apparatus in which the raw material monomer and the polymerization initiator are subjected to continuous polymerization in the first and second reaction tanks of the complete mixing type connected in series by the connection line. An operation method,
The raw material monomer is continuously supplied to the first reaction tank in a state where the supply of the polymerization initiator to the fully mixed first reaction tank is stopped, and the raw material monomer-containing fluid in the first reaction tank With continuous stirring as the first fluid from the first reaction vessel,
The first fluid is continuously supplied from the first reaction tank to a fully mixed second reaction tank through a connection line equipped with temperature control means, and in the absence of a new polymerization initiator, Continuously extracting as a second fluid from the second reaction tank while stirring the raw material monomer-containing fluid in the second reaction tank,
The first so that the pressure difference _P 1 -P ₂ of the pressure _{P 1} in the reaction vessel and the pressure _{P 2} of the second reaction vessel is less than 0.05MPa or 0 MPa, temperature adjustment of the connecting line Adjusting the temperature of the first fluid through the connecting line by means. The temperature adjustment means of the connection line is adjusted so that the temperature difference T _m -T ₁ between the temperature T ₁ in the first reaction tank and the set temperature T _m of the temperature adjustment means of the connection line is 10 ° C. or more and 60 ° C. or less. adjusting the set temperature T _m, the operation method of the continuous polymerization apparatus according to claim 1. The pressure _{P 1} in the first reaction vessel is 1.0~2.0MPa gauge pressure, the temperature _{T 1} of the first reaction vessel is 120 to 170 ° C., continuous polymerization according to claim 2 How to operate the device.   The operating method of the continuous polymerization apparatus in any one of Claims 1-3 in which a raw material monomer contains 50 mass% or more of methyl methacrylate, and continuous polymerization is continuous block polymerization.

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