JP2008231150A - Method for controlling polymerization reaction and device for controlling the reaction - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for controlling the polymerization reaction by controlling the temperature of an outer bath so that the total dripping amount of a solvent dripped until the completion of the polymerization reaction becomes an objective amount set in advance, and a device for controlling the polymerization reaction. <P>SOLUTION: This method for controlling the polymerization reaction is constituted by calculating the accumulated dripped amount (n) [kg] of the solvent at the time point of passing (tn), on passing (tn) min (in this embodiment, 30 min) from the start of the polymerization reaction (S12), calculating the ΔSV of controlling amount of the temperature of the outer bath (S13) by substituting the calculated accumulated dripped amount (n) to a calculation formula (1): ΔSV [°C]=-0.285(n)×12.555 (1) obtained by performing a prior experiment in advance, and setting the temperature of the outer bath afterwards by the temperature obtained by adding the calculated ΔSV to the set temperature (S14) so that the total dripping amount of the dripped solvent until the completion of the reaction becomes the objective value set in advance. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a polymerization reaction control method and a polymerization reaction control device for controlling a polymerization reaction when a polymer used for an adhesive or the like is synthesized, and in particular, a total dripping amount of a solvent dropped before the completion of the polymerization reaction The present invention relates to a polymerization reaction control method and a polymerization reaction control apparatus for controlling the temperature of an outer bath so that the temperature reaches a preset target amount.

Conventionally, when synthesizing a polymer used for an adhesive or the like, the polymer is synthesized by dropping an initiator into a monomer charged in advance in a stirring tank to cause a monomer mixture to undergo a polymerization reaction. At that time, in order to improve the reproducibility of the polymerization reaction, it is extremely important to reduce the difference from the target temperature with respect to the polymerization temperature (hereinafter referred to as the inner bath temperature).
Therefore, it is necessary to appropriately remove the heat generated by the polymerization accompanying the polymerization reaction, but this is carried out using two types of methods represented below.
(1) A method of removing heat of polymerization heat by performing heat exchange with a cooling jacket installed outside the stirring tank (see, for example, JP-A-2004-256734).
Operating parameters: Outer bath refrigerant temperature, stirring blade rotation speed (heat transfer efficiency)
(2) A method of removing heat generated by polymerization by dropping a solvent (or dispersion medium) having a temperature lower than the polymerization temperature into the system.
Operation parameters: amount of solvent dripping, dripping timing
JP 2004-256734 A

Of the above two methods, the delay time until the actual heat removal effect appears after the start of control is short (the temperature control response is high) is the method of (2) by low temperature solvent dropping.
Particularly, when the polymerization proceeds and the liquid viscosity increases, the boundary film on the inner bath side increases, so that the temperature control response is remarkably reduced by the method (1), and the inner bath temperature cannot be suitably controlled. (2) Control based on this method is important. Therefore, when performing polymerization that results in a particularly high viscosity, the outer bath temperature set value and the stirring speed set value are fixed at predetermined values, and heat is roughly removed. It is necessary to carry out highly accurate temperature control that removes heat by dripping solvent.

Here, there are the following two methods as specific methods for dropping the solvent in the heat removal method (2).
(I) A method in which threshold values for the inner bath temperature are determined stepwise, and when each threshold value is exceeded, a fixed amount of solvent is dropped into the reaction system.
(Ii) A method in which an equation for calculating the optimum amount of solvent dripping using the inner bath temperature and the rate of change in the inner bath temperature as a function is obtained in advance by experiments or the like, and the calculated amount of the solvent is dripped into the reaction system.

  By using the methods (i) and (ii) above, it is possible to suitably control the inner bath temperature near the target temperature. However, even if any of the above dropping methods is employed, the total dropping amount varies, and as a result, the physical property (molecular weight) of the obtained polymer varies.

The reason why the total amount of solvent dripped affects the molecular weight of the polymer is that the solvent itself has an effect as a chain transfer agent for the polymerization reaction, and the monomer concentration is lowered by dripping (the molecular weight depends on the monomer concentration). And so on. Then, it is known that a correlation as shown in FIG. 10 is obtained between the total dripping amount of the solvent actually used for polymerization and the generated polymer molecular weight.
Therefore, in order to obtain desired polymer properties, it is necessary to keep the total amount of solvent dripped within a certain range.
However, in actual production sites, the total amount of solvent dropped varies due to variations in dissolved oxygen concentration in the stirring tank. That is, when the reaction inhibition effect changes due to the variation in dissolved oxygen concentration, the polymerization rate, the exothermic behavior, and the total dripping amount of the solvent change, and as a result, the polymer molecular weight changes. When the change in the molecular weight of the polymer exceeds a predetermined range, an abnormal lot may occur, leading to a decrease in product yield.

And the following factors can be considered for variation in the dissolved oxygen concentration in said stirring tank.
Nitrogen substitution condition variation, oxygen mixing at the time of initiator addition, polymerization temperature (reaction solution temperature) variation, concentration variation of inhibitor contained in various monomers, other impurity contamination concentration variation, dropping solvent temperature, dissolved oxygen in dropping solvent Concentration.
These factors work as factors for changing the polymerization rate, and as a result, the amount of the solvent dropped for cooling changes.

Therefore, there are the following two methods for improving the above problem.
(I) A method of measuring and managing all production lots so that all the above-mentioned factors do not affect the reaction.
(II) A method in which the internal bath temperature is controlled by another control factor while the solvent is continuously dropped at a constant amount and interval even if the above-described variation generation factor affects the reaction.

However, with regard to the method (I), there are many cases where multiple production facilities are introduced in batch-type production facilities, and it is very difficult to measure and control the above factors in all these production facilities. This is unrealistic (including maintenance of measuring instruments).
On the other hand, with respect to the method (II), examples of other control factors here include the outer bath temperature set value and the set value of the stirring blade rotation speed. As described above, these have large time constants. Detailed temperature control is not possible.

  The present invention has been made to solve the above-described problems in the prior art, and by quantifying the degree of influence on the reaction due to various variation factors by the cumulative amount of solvent in the middle of polymerization, and at the end of the reaction It is an object of the present invention to provide a polymerization reaction control method and a polymerization reaction control apparatus that prevent variations in physical properties (molecular weight) of a polymer while improving the reproducibility of the polymerization reaction by predicting the total amount of dripping.

  In order to achieve the above object, the polymerization reaction control method according to claim 1 of the present application controls the outer bath temperature of the stirring tank in the course of synthesizing the polymer by the polymerization reaction by introducing the monomer mixture into the stirring tank, In a polymerization reaction control method for controlling a polymerization reaction by dropping a solvent into a stirring vessel, an integrated dropping amount of the solvent from the start of polymerization is calculated at a predetermined timing during the polymerization reaction, and the polymerization reaction is completed in advance by the end of the polymerization reaction. The temperature of the outer bath is controlled based on the calculated cumulative dripping amount of the solvent so as to drop the total dripping amount of the solvent.

  Further, the polymerization reaction control method according to claim 2 is the polymerization reaction control method according to claim 1, wherein the temperature difference of the outer bath based on the cumulative dripping amount of the solvent is determined as follows. The polymerization reaction is performed using a plurality of types of solvents, and the outer bath temperature is changed after a predetermined time from the start of the polymerization, and the temperature difference of the outer bath temperature changed for each type of the solvent used and the total dropwise addition until the end of the polymerization reaction The control amount of the temperature of the outer bath is obtained from the relationship between the temperature difference that becomes the target total dripping amount and the cumulative dripping amount of the solvent up to the time of changing the outer bath temperature.

  Further, the polymerization reaction control method according to claim 3 is the polymerization reaction control method according to claim 1 or claim 2, wherein the timing for calculating the cumulative dripping amount of the solvent is determined as follows. Performing a polymerization reaction using a plurality of types of solvents, for each type of the solvent used, to determine the correlation between the cumulative amount of the solvent dropped from the start of polymerization and the total amount of dripping from the polymerization reaction until the end of the polymerization reaction, the correlation Is the predetermined height or more and the earliest timing from the start of polymerization is obtained as the timing for calculating the cumulative amount of the solvent.

  The polymerization reaction control device according to claim 4 is a stirring tank for stirring the monomer mixture, an outer bath temperature control means for controlling the temperature of the outer bath of the stirring tank, and a dropping for dropping a solvent into the stirring tank. Means, and in the process of synthesizing the polymer by polymerization reaction by introducing the monomer mixture into the stirring tank, the outer bath temperature is controlled by the outer bath temperature control means, and the solvent is stirred by the dropping means. In the polymerization reaction control apparatus for controlling the polymerization reaction by dripping in, provided with a dripping amount calculating means for calculating the cumulative dripping amount of the solvent from the start of polymerization at a predetermined timing during the polymerization reaction, the outer bath temperature control The means controls the temperature of the outer bath based on the cumulative drop amount of the solvent calculated by the drop amount calculation means so as to drop a preset total drop amount of the solvent by the end of the polymerization reaction. To.

  The polymerization reaction control device according to claim 5 is the polymerization reaction control device according to claim 4, wherein the control amount of the temperature of the outer bath based on the cumulative dripping amount of the solvent by the outer bath temperature control means is as follows. The polymerization reaction is carried out using a plurality of types of solvents at different temperatures, the outer bath temperature is changed after a predetermined time from the start of polymerization, and the temperature difference between the outer bath temperature and the polymerization changed for each type of solvent used. Calculate the total dripping amount until the end of the reaction, and obtain the control amount of the temperature of the outer bath from the relationship between the temperature difference that becomes the target total dripping amount and the cumulative dripping amount of the solvent until the change of the outer bath temperature. It is characterized by.

  Furthermore, the polymerization reaction control device according to claim 6 is the polymerization reaction control device according to claim 4 or claim 5, wherein the timing for calculating the cumulative dripping amount of the solvent by the dripping amount calculating means is as follows. The polymerization reaction is performed using a plurality of types of solvents at different temperatures to be obtained, and the correlation between the total amount of dripping of the solvent and the total amount of dripping from the start of polymerization to the end of the polymerization reaction every predetermined time for each type of the solvent used. The correlation is equal to or higher than a predetermined height and the earliest timing from the start of polymerization is determined as the timing for calculating the cumulative dripping amount of the solvent.

  In the polymerization reaction control method according to claim 1 having the above-described configuration, the cumulative dripping amount of the solvent from the start of polymerization is calculated at a predetermined timing during the polymerization reaction, and the total dripping amount set in advance by the end of the polymerization reaction is calculated. Since the temperature of the outer bath is controlled based on the cumulative amount of solvent calculated so that the solvent is dripped, the degree of influence on the reaction due to various dispersion factors such as dissolved oxygen concentration by the cumulative amount of solvent during polymerization Alternatively, by quantifying the amount and predicting the total dropping amount at the end of the reaction, it is possible to improve the reproducibility of the polymerization reaction and prevent variations in the physical properties (molecular weight) of the polymer.

  Moreover, in the polymerization reaction control method according to claim 2, the polymerization reaction is performed using a plurality of types of solvents at different temperatures, the outer bath temperature is changed after a predetermined time from the start of the polymerization, and is changed for each type of solvent used. Calculate the temperature difference of the outer bath temperature and the total dripping amount until the completion of the polymerization reaction, and calculate the outer bath from the relationship between the temperature difference that becomes the target total dripping amount and the cumulative dripping amount of the solvent until the change of the outer bath temperature. Therefore, by controlling the outer bath temperature, the total dripping amount of the solvent can be always kept within a certain range, and desired polymer physical properties can be obtained.

  In the polymerization reaction control method according to claim 3, the polymerization reaction is performed using a plurality of types of solvents at different temperatures, and the cumulative amount of the solvent dropped and the polymerization reaction every predetermined time from the start of polymerization for each type of solvent used. Since the correlation with the total dripping amount until completion is obtained, and the correlation is equal to or higher than a predetermined height and the earliest timing from the start of polymerization is obtained as the timing for calculating the cumulative dripping amount of the solvent, The temperature setting range of the bath can be reduced, and the influence of disturbance due to control such as overshoot can be reduced.

  Further, in the polymerization reaction control device according to claim 4, the cumulative dropping amount of the solvent from the start of the polymerization is calculated at a predetermined timing during the polymerization reaction, and the total dropping amount of the solvent set in advance by the end of the polymerization reaction is calculated. Since the temperature of the outer bath is controlled based on the cumulative amount of solvent calculated to be dripped, the cumulative amount of solvent in the middle of polymerization substitutes the degree of influence on the reaction due to various variation factors such as dissolved oxygen concentration. By quantitatively quantifying and predicting the total dropping amount at the end of the reaction, it is possible to prevent variations in the physical properties (molecular weight) of the polymer while improving the reproducibility of the polymerization reaction.

  Further, in the polymerization reaction control apparatus according to claim 5, the polymerization reaction is performed using a plurality of types of solvents at different temperatures, the outer bath temperature is changed after a predetermined time from the start of the polymerization, and is changed for each type of the solvent used. The temperature difference between the outer bath temperatures and the total dripping amount until the end of the polymerization reaction are calculated, respectively, and it is excluded from the relationship between the temperature difference that becomes the target total dripping amount and the cumulative dripping amount of the solvent until the change of the outer bath temperature. Since the control amount of the bath temperature is obtained, the total dripping amount of the solvent can be always kept within a certain range by controlling the outer bath temperature, and desired polymer physical properties can be obtained.

  Furthermore, in the polymerization reaction control apparatus according to claim 6, the polymerization reaction is performed using a plurality of types of solvents at different temperatures, and the cumulative amount of the solvent dropped and the polymerization reaction every predetermined time from the start of polymerization for each type of solvent used. Since the correlation with the total dripping amount until completion is obtained, and the correlation is equal to or higher than a predetermined height and the earliest timing from the start of polymerization is obtained as the timing for calculating the cumulative dripping amount of the solvent, The temperature setting range of the bath can be reduced, and the influence of disturbance due to control such as overshoot can be reduced.

  DETAILED DESCRIPTION Hereinafter, a polymerization reaction control method and a polymerization reaction control device according to the present invention will be described in detail with reference to the drawings based on specific embodiments. First, the polymerization reaction control apparatus 1 according to this embodiment will be described with reference to FIG. FIG. 1 is a schematic side view showing a main part of a polymerization reaction control device 1 according to this embodiment.

  As shown in FIG. 1, a polymerization reaction control apparatus 1 according to this embodiment includes a stirrer 2 that synthesizes a polymer from a charged monomer mixture, and a solvent (cooling water in this embodiment) in a stirrer 3 that constitutes the stirrer 2. Is basically composed of a dripping tank 4 for dripping, an outer bath temperature of the stirring tank 3, a controller 5 for controlling the dripping of the solvent, and the like, and an operation section 6 for performing input setting and operation of various conditions.

  Each configuration will be specifically described below. The dropping tank 4 corresponds to the dropping means of the present invention, and the control unit 5 corresponds to the outer bath temperature control means and the dropping amount calculation means.

  The stirrer 2 includes a stirring tank 3 having a bowl-like bottom, a rotating shaft 7 that is cantilevered from above the center of the stirring tank 3, and a stirring blade 8 attached to the rotating shaft 7. . The rotation shaft 7 is connected to a rotation driving means (not shown) and rotates around the Y axis in the drawing. A jacket 9 is attached to the outer periphery of the stirring tank 3 as temperature adjusting means for controlling the polymerization temperature of the polymerization reaction performed in the stirring tank 3 (inner bath temperature in the stirring tank 3).

Further, the stirring tank 3 is provided with a condenser 11 with respect to the upper lid 10. The condenser 11 cools and returns the water evaporated in accordance with the polymerization reaction to water, and discharges unnecessary nitrogen (N ₂ ) supplied to the stirring tank 3. Nitrogen is supplied in a timely and appropriate amount from a nitrogen tank (not shown) disposed in the vicinity thereof through a pipe connected to the lower and upper portions of the stirring tank 3. A temperature sensor S1 for detecting the temperature of the inner bath is attached to the bottom.

  On the other hand, the jacket 9 is connected to the upper and lower portions of a pipe R1 for supplying and discharging the temperature adjusting fluid. A heat exchanger 15 is provided on the jacket inlet side (lower part in FIG. 1) of the pipe R1. The heat exchanger 15 raises the temperature of the water circulating in the pipe R <b> 1 in order to raise the temperature in the stirring tank 3, and supplies the hot water to the jacket 9. Further, the heat exchanger 15 is connected to a pipe R2 through which steam is supplied by opening the valve V1. Further, the pipe R1 is provided with a valve V2 for discharging hot water or cooling water circulating through the pipe R1 in order to cool the stirring tank 3, and when the valve V2 is opened to discharge hot water or the like. A pipe R3 for supplying new cooling water to the pipe R1 is connected to the pipe R1 through a valve V3.

  In addition, a temperature sensor S2 for detecting the inlet temperature of the outer bath is provided on the pipe R1 on the side for supplying the temperature adjusting fluid to the jacket 9 (in the vicinity of the lower portion of the jacket 9 in FIG. 1). On the other hand, on the discharge side (in the vicinity of the upper part of the jacket 9 in FIG. 1), there are a temperature sensor S3 for detecting the outlet temperature of the outer bath and a jacket circulating water flow meter F1 for detecting the flow rate of circulating water circulating through the jacket 9. Each is provided.

  The dripping tank 4 stores a solvent (cooling water in this embodiment) adjusted to a predetermined temperature and a predetermined dissolved oxygen concentration. A jacket 21 for keeping the temperature of the solvent constant is attached to the outer periphery. Further, a temperature sensor S4 for detecting the temperature of the inner bath (cooling water temperature) is disposed inside the dropping tank 4. The jacket 21 is circulated with the cooling water whose setting is changed in a timely manner based on the temperature of the cooling water detected by the temperature sensor S4. As for the dissolved oxygen concentration, in the process of being supplied from the dropping tank 4, oxygen may be supplied and stirred with a static mixer or the like to adjust the concentration level in a timely manner.

Moreover, piping is connected to the upper and lower portions of the dropping tank 4, and nitrogen (N ₂ ) is supplied from each piping. Then, nitrogen replacement is performed in which nitrogen is supplied to the dropping tank 4 and oxygen in the dropping tank 4 is discharged from the exhaust pipe.

  Furthermore, the dripping tank 4 is connected to the stirring tank 3 through a pipe R4 provided with a valve V4. Then, a predetermined amount of the solvent in the dropping tank 4 is dropped into the stirring tank 3 by opening and closing the valve V4 under the control of the control unit 5 described later. Note that a solvent flow meter F2 that detects the dripping amount of the solvent supplied to the stirring tank 3 is attached to the pipe R4.

  The control unit 5 is a control unit that controls the polymerization reaction performed in the polymerization reaction control device 1 by controlling the outer bath temperature of the stirring tank 3 and the dropping of the solvent, and is arranged on the circuit board according to a preset program. A CPU that performs control operations and ROM, RAM, and the like, which are storage means, are provided. In addition, various setting conditions such as the control amount and control timing of the temperature of the outer bath according to the polymer synthesis conditions and the amount and timing of dropping the solvent into the stirring tank 3 are input and set to the control unit 5 from the operation unit 6 in advance. And stored in a memory such as a RAM. And based on the various conditions memorize | stored and the measurement result from each sensor, outer bath temperature and dripping of a solvent are controlled as mentioned later.

Next, a polymerization reaction control method of the polymerization reaction control device 1 having the above configuration will be described.
First, a monomer solution prepared in advance is drawn into the stirring tank 3 of the stirrer 2. Further, a dropping solvent is drawn into the dropping tank 4. Thereafter, the temperature of the temperature adjusting fluid circulating through the jacket 9 and the jacket 21 is adjusted, and the temperatures of the outer baths of the stirring tank 3 and the dropping tank 4 are set to the target temperature (the stirring tank 3 is 59 ° C., the dropping tank 4 is 15 ° C.). Adjust the temperature.
Next, nitrogen substitution is performed by bubbling a monomer solution or a solvent at an arbitrary nitrogen flow rate. After carrying out nitrogen substitution for a specified time, stop nitrogen feeding from the liquid phase part and switch to feeding from the gas phase part. Then, after confirming that the inner bath temperature is stable, a polymerization initiator is added.
After that, the apparatus was on standby with the set temperature of the outer bath of the stirring tank 3 fixed at 59 ° C., and it was confirmed that the inner bath temperature was increased and the polymerization reaction was started, and at the same time, the control of the polymerization reaction by the control unit 5 was started. To do.
When the control of the polymerization reaction is started, the outer bath temperature of the stirring tank 3 is first set to 40 ° C., set to 20 ° C. after 10 minutes, and from 150 minutes to the end of the reaction (180 minutes). Set to 50 ° C.
On the other hand, when the inner bath temperature of the stirring tank 3 is 60 ° C. or higher, the valve V4 is opened and the solvent from the dropping tank 4 is dropped. Here, the dropping of the solvent is performed by repeatedly dropping 10 kg of the solvent over 120 seconds until the inner bath temperature becomes less than 60 ° C.
Further, when 30 minutes have elapsed from the start of the polymerization reaction, the cumulative drop amount n [kg] of the solvent at the point of 30 minutes was calculated, and the calculated cumulative drop amount n was obtained by conducting a preliminary experiment in advance. By substituting into the following equation (1), the control amount of the outer bath temperature (correction amount of the set temperature of the outer bath) ΔSV is calculated.
ΔSV [° C.] = − 0.285 n × 12.555 (1)
Then, the temperature of the outer bath after that is set by the temperature obtained by adding the calculated ΔSV to the set temperature (for example, when ΔSV = 2 ° C. is calculated, 150 minutes have elapsed from the start of the polymerization reaction). (2), the outside bath temperature is newly set to 22 ° C., which is increased by 2 ° C., and is set to 52 ° C. after 150 minutes until the end of the reaction. Thereby, the total amount of solvent dripped before the end of the reaction can be set to a preset target value.

  Next, each process related to the polymerization reaction control of the polymerization reaction control apparatus 1 according to this embodiment having the above-described configuration will be described with reference to FIGS. FIG. 2 is a flowchart of an outer bath temperature control program of the stirring tank 3 of the polymerization reaction control apparatus 1 according to this embodiment. FIG. 3 is a flowchart of the solvent dropping control program of the polymerization reaction control apparatus 1 according to this embodiment. The outer bath temperature control program for the stirring tank 3 is started at the same time as confirming that the polymerization initiator has been introduced into the stirring tank 3 and the inner bath temperature has risen to initiate the polymerization reaction. 2 and FIG. 3 are stored in the RAM or ROM provided in the control unit 5 and executed by the CPU.

  Here, as shown in FIG. 2, the flowchart of the outer bath temperature control program of the stirring tank 3 is basically constituted by two flowcharts. One is a basic control flowchart for changing the set temperature of the outer bath of the stirring tank 3 as the predetermined time elapses from the start of the polymerization reaction, and the other is based on the cumulative amount of solvent dropped at a predetermined timing, It is a preset temperature correction control flowchart which adds correction | amendment to the preset temperature of the subsequent outer bath.

  First, in the outer bath temperature control program, in step (hereinafter abbreviated as S) 1, the control unit 5 starts measuring the timer TM1 indicating the elapsed time from the start of the polymerization reaction. Next, in S2, the control unit 5 controls the opening degree of the heat exchanger 15 and the valves V1 to V3 to set the set temperature of the outer bath temperature SV of the stirring tank 3 to T1 (° C.). Here, in this embodiment, T1 is basically 40 ° C., but when the set temperature is corrected by the process of S14 described later, it is set to the set temperature after correction.

  Subsequently, in S3, the control unit 5 determines whether or not the elapsed time from the start of the polymerization reaction indicated by the timer TM1 has reached t1. In the present embodiment, t1 is 10 minutes. When it is determined that the elapsed time from the start of the polymerization reaction has become t1 (S3: YES), the process proceeds to S4. On the other hand, when it is determined that the elapsed time from the start of the polymerization reaction is not t1 (S3: NO), the process waits until t1 elapses.

  In S4, the control unit 5 controls the opening degree of the heat exchanger 15 and the valves V1 to V3 to set the set temperature of the outer bath temperature SV of the stirring tank 3 to T2 (° C.). Here, in this embodiment, T2 is basically 20 ° C., but when the set temperature is corrected by the process of S14 described later, it is set to the corrected set temperature.

  Subsequently, in S5, the control unit 5 determines whether or not the elapsed time from the start of the polymerization reaction indicated by the timer TM1 has reached t2. In this embodiment, t2 is 150 minutes. When it is determined that the elapsed time from the start of the polymerization reaction has become t2 (S5: YES), the process proceeds to S6. On the other hand, when it is determined that the elapsed time from the start of the polymerization reaction is not t2 (S5: NO), the process waits until t2.

  In S6, the control unit 5 controls the opening degree of the heat exchanger 15 and the valves V1 to V3 to set the set temperature of the outer bath temperature SV of the stirring tank 3 to T3 (° C.). Here, in this embodiment, T3 is basically 50 ° C., but when the set temperature is corrected by the process of S14 described later, it is set to the corrected set temperature.

  Subsequently, in S7, the control unit 5 determines whether or not the elapsed time from the start of the polymerization reaction indicated by the timer TM1 has reached 180 minutes when the polymerization reaction ends. In this embodiment, the time until the completion of the polymerization reaction is 180 minutes, but this time varies depending on the polymer production conditions. If it is determined that the elapsed time from the start of the polymerization reaction is 180 minutes (S7: YES), the outer bath temperature control program is terminated. On the other hand, when it is determined that the elapsed time from the start of the polymerization reaction is not 180 minutes (S7: NO), the process waits until 180 minutes have elapsed.

  In the outer bath temperature control program, in S11, the control unit 5 determines whether or not the elapsed time from the start of the polymerization reaction indicated by the timer TM1 has reached tn. In this embodiment, tn is 30 minutes, but the value of tn is obtained by a preliminary experiment described later. When it is determined that the elapsed time from the start of the polymerization reaction has become tn (S11: YES), the process proceeds to S12. On the other hand, when it is determined that the elapsed time from the start of the polymerization reaction is not tn (S11: NO), the process waits until tn elapses.

  In S12, the control unit 5 calculates the cumulative dropping amount n of the solvent from the dropping tank 4 at the time when tn has elapsed, based on the detection result of the solvent flow meter F2.

Next, in step S13, the control unit 5 substitutes the integrated drop amount n calculated in step S12 into the following arithmetic expression (1) obtained in advance in advance, thereby controlling the temperature (control amount) ΔSV of the temperature of the outer bath. Is calculated.
ΔSV [° C.] = − 0.285 n × 12.555 (1)

  Further, in S14, the control unit 5 corrects the subsequent temperatures T1 to T3 of the outer bath with the temperature obtained by adding ΔSV calculated in S13 to the set temperature. For example, when ΔSV = 2 ° C. is calculated in the present embodiment, the outer bath temperature is newly increased to 22 ° C. by increasing the current set temperature by 2 ° C. until 150 minutes have elapsed from the start of the polymerization reaction. In step S6, the outer bath temperature is set to 52 ° C. In the present embodiment, when ΔSV = −1.5 ° C. is calculated, the current set temperature is decreased by 1.5 ° C. to 18.5 ° C. until 150 minutes have elapsed from the start of the polymerization reaction. The outer bath temperature is newly set, and the outer bath temperature is set to 48.5 ° C. in S6. Thus, by correcting the set temperature of the outer bath, the total amount of solvent dripped before the end of the reaction can be set to a preset target value.

  Subsequently, in the solvent dropping control program shown in FIG. 3, first, in S <b> 21, the control unit 5 detects the inner bath temperature of the stirring tank 3 by the temperature sensor S <b> 1. Next, in S22, the controller 5 determines whether or not the inner bath temperature detected in S21 is equal to or higher than T4 (for example, 60 ° C.).

  When it is determined that the inner bath temperature is equal to or higher than T4 (S22: YES), the process proceeds to S23, the valve V4 is opened, and the dropping of the solvent is started. The solvent is dropped by adding A kg (for example, 10 kg) of solvent over a period of t3 seconds. On the other hand, when it is determined that the inner bath temperature is lower than T4 (S22: NO), the process proceeds to S26.

  Thereafter, in S24, the control unit 5 starts measuring the timer TM2 indicating the elapsed time from the start of the dropping of the solvent. In S25, the control unit 5 determines whether or not the elapsed time from the start of dropping of the solvent indicated by the timer TM2 has reached t3. In the present embodiment, t3 is 120 seconds. And when it determines with the elapsed time from the dripping start of a solvent having become t3 (S25: YES), it transfers to S26. On the other hand, when it is determined that the elapsed time from the start of the dropping of the solvent is not t3 (S25: NO), the process waits until t3 elapses.

  Next, in S26, the control unit 5 determines whether the elapsed time from the start of the polymerization reaction indicated by the timer TM1 has passed 180 minutes when the polymerization reaction ends. In this embodiment, the time until the completion of the polymerization reaction is 180 minutes, but this time varies depending on the polymer production conditions. When it is determined that the elapsed time from the start of the polymerization reaction has passed 180 minutes (S26: YES), the solvent dropping control program is terminated. On the other hand, when it is determined that the elapsed time from the start of the polymerization reaction has not passed 180 minutes (S26: NO), the process returns to S21, and the inner bath temperature of the stirring tank 3 is detected again.

  Subsequently, in the preliminary experiment 1 for obtaining the elapsed time tn from the reaction start time, which is the timing for calculating the cumulative amount of solvent determined in S11, and in calculating the control amount of the outer bath temperature in S13. A preliminary experiment 2 for obtaining the arithmetic expression (1) used in the above will be described.

[Preliminary experiment 1]
In the preliminary experiment 1, the polymerization reaction control apparatus 1 shown in FIG. 1 was used, and four types of solvents A to D having different temperatures (solvent A: 15 ° C., solvent B: 20 ° C., solvent C: 25 ° C., solvent D: 30 C.) is added dropwise to adjust the inner bath temperature of the stirring vessel 3, polymerize the monomer mixture in the stirring vessel 3, and synthesize the polymer. In addition, the outer bath temperature of the stirring tank 3 is controlled by the control part 5 according to the process (FIG. 2) of S1-S7 already demonstrated. Further, the dropping of the solvent is controlled by the control unit 5 in accordance with the processes of S21 to S26 already described (FIG. 3).

First, when the preliminary experiment 1 is performed, nitrogen is substituted by bubbling the stirring tank 3 at an arbitrary nitrogen flow rate. And after nitrogen substitution is performed for 4 hours, the nitrogen feeding from the liquid phase part is stopped, and it switches to the feeding from the gas phase part. Then, after confirming that the inner bath temperature is stable, a polymerization initiator is added.
Then, the outer bath temperature of the agitation tank 3 is controlled according to the processing of S1 to S7 (FIG. 2), and the dropping of the solvent is controlled according to the processing of S21 to S26 (FIG. 3). FIG. 4 is a graph showing the cumulative amount of solvent dripped at each time from the start to the end of the polymerization reaction for each of the solvents A to D used in the experiment as a result of polymer synthesis under the above conditions.

Next, the cumulative drop amount of the solvent and the final total drop amount from the start of the reaction to every 30 minutes are plotted every 10 minutes, and the correlation is equal to or higher than a predetermined height (in this embodiment, the determination coefficient R ² is 0.9 or more) and the earliest time from the start of the polymerization reaction is obtained. FIG. 5 is a graph showing the cumulative amount of solvent added 10 minutes after the start of the polymerization reaction and the total amount of dripping required thereafter until the end of the reaction, for each of the solvents A to D used in the experiment, and FIG. FIG. 7 shows the cumulative amount of solvent dropped 20 minutes after the start and the total amount of dripping required until the end of the reaction for each of the solvents A to D used in the experiment. FIG. 7 shows the result after 30 minutes from the start of the polymerization reaction. It is the figure which showed the total dripping amount required until the completion | finish of reaction after the total dripping amount of a solvent for every solvent AD used for experiment.

First, the correlation between the cumulative dripping amount of the solvent and the total dripping amount after 10 minutes from the start of the polymerization reaction is determined based on FIG. As shown in FIG. 5, the regression line determined based on each plot is y = 12.92x + 214.96. The coefficient of determination R ² calculated based on the difference between the actual measurement data becomes 0.37.

Next, the correlation between the cumulative dripping amount of the solvent and the total dripping amount after 20 minutes from the start of the polymerization reaction is determined based on FIG. As shown in FIG. 6, the regression line determined based on each plot is y = 9.90x + 97.63. The coefficient of determination R ² calculated based on the difference between the actual measurement data becomes 0.83.

Furthermore, the correlation between the cumulative dripping amount of the solvent and the total dripping amount after 30 minutes from the start of the polymerization reaction is determined based on FIG. As shown in FIG. 7, the regression line determined based on each plot is y = 5.39x + 110.19. The determination coefficient R ² calculated based on the difference from the actual measurement data is 0.91.
Therefore, (in the present embodiment, the coefficient of determination R ² is 0.9 or higher) correlated than the predetermined height, and the polymerization reaction earliest time is the time from the start of the 30 minute elapsed time from the beginning of the polymerization reaction It is required to be.

  And let the calculated | required time (at the time of 30-minute progress from a polymerization reaction start) be the elapsed time tn from the reaction start time which is a timing which calculates the cumulative dripping amount of the solvent determined by said S11. Further, the molecular weight of the polymer obtained at this time is measured, and the optimum total dripping amount of the solvent for obtaining a desired molecular weight is derived from the correlation between the total dripping amount of the solvent and the polymer molecular weight shown in FIG. In the present embodiment, assuming that the optimum total amount of the solvent dropped is 350 kg, the preliminary experiment 2 will be described below.

[Preliminary experiment 2]
In the preliminary experiment 2, similarly to the preliminary experiment 1, the polymerization reaction control apparatus 1 shown in FIG. 1 is used, and four types of solvents A to D (solvent A: 15 ° C., solvent B: 20 ° C., solvent C: 25 having different temperatures) are used. C., solvent D: 30.degree. C.) is added dropwise to adjust the inner bath temperature of the stirring tank 3, polymerize the monomer mixture in the stirring tank 3, and synthesize the polymer. In addition, the outer bath temperature of the stirring tank 3 is controlled by the control part 5 according to the process (FIG. 2) of S1-S7 already demonstrated. Further, the dropping of the solvent is controlled by the control unit 5 in accordance with the processes of S21 to S26 already described (FIG. 3).
Further, regarding the control of the outer bath temperature of the stirring tank 3 in the preliminary experiment 2, the set temperature of the outer bath of the subsequent stirring tank 3 at the time of tn obtained in the preliminary experiment 1 (30 minutes after the start of the polymerization reaction). Are changed by -4 ° C, -2 ° C, ± 0, + 2 ° C, and + 4 ° C.
Here, FIG. 8 shows the result of synthesizing the polymer under the above conditions. As a result, the amount of change in the outer bath temperature after the start of the polymerization reaction and the total dripping amount of the solvent required until the end of the polymerization reaction are shown. It is the figure shown for every solvent AD used for experiment.

First, referring to each plot in the case of using the solvent A based on FIG. 8 and finding a regression line, y = 19.5x + 272.8. Then, based on the regression line, the temperature change of the outer bath for dropping 350 kg which is the optimum total dripping amount of the solvent is obtained by the following calculation formula (2).
(350-272.8) /19.5=3.96 [° C.] (2)
Therefore, when the solvent A is used, the total amount of the solvent required to complete the polymerization reaction can be 350 kg by increasing the subsequent bath temperature by 3.96 ° C. after elapse of tn. I understand that.

Next, referring to each plot in the case of using the solvent B based on FIG. 8, the regression line is obtained, and y = 20.3x + 311.0. Then, based on the regression line, the temperature change of the outer bath for dropping 350 kg which is the optimum total dripping amount of the solvent is obtained by the following arithmetic expression (3).
(350-311.0) /20.3=1.92 [° C.] (3)
Therefore, when the solvent B is used, the total amount of the solvent required to complete the polymerization reaction can be 350 kg by raising the subsequent outer bath temperature by 1.92 ° C. after the time tn has elapsed. I understand that.

Next, referring to each plot when the solvent C is used based on FIG. 8, the regression line is obtained, and y = 26.3x + 370.0. Then, based on the regression line, the temperature change of the outer bath for dropping 350 kg which is the optimum total dropping amount of the solvent is obtained by the following calculation formula (4).
(350−370.0) /26.3=−0.76 [° C.] (4)
Therefore, when the solvent C is used, the total amount of the solvent required to complete the polymerization reaction can be reduced to 350 kg by lowering the subsequent outer bath temperature by 0.76 ° C. at the time when tn has elapsed. I understand that.

Further, referring to each plot when the solvent D is used based on FIG. 8, the regression line is obtained and y = 24.1x + 397.3. Then, based on the regression line, the temperature change of the outer bath for dropping 350 kg which is the optimum total dropping amount of the solvent is obtained by the following arithmetic expression (5).
(350-397.3) /24.1=-1.96 [° C.] (5)
Therefore, when the solvent C is used, the total amount of the solvent required to complete the polymerization reaction can be reduced to 350 kg by lowering the subsequent outer bath temperature by 1.96 ° C. after the time tn has elapsed. I understand that.

  Next, the temperature control amount ΔSV of the outer bath to be the optimum total dripping amount of the solvent (350 kg) and the cumulative dripping amount of the solvent when tn has elapsed (30 minutes after the start of the polymerization reaction) are plotted. FIG. 9 shows the temperature control amount ΔSV of the outer bath for setting the total dripping amount of the solvent to 350 kg and the cumulative dripping amount of the solvent after 30 minutes from the start of the polymerization reaction for each of the solvents A to D used in the experiment. It is a figure.

  Here, referring to the plots of the respective solvents A to D based on FIG. 9, the regression line is obtained, and y = −0.285x + 12.555. This equation corresponds to the above equation (1), and the temperature control amount ΔSV of the outer bath performed at the time point tn is calculated by substituting the integrated dripping amount at the time point tn after the start of the polymerization reaction. It becomes possible.

  Therefore, by the preliminary experiment 1 described above, an elapsed time tn from the reaction start time, which is the timing for calculating the cumulative dripping amount of the solvent determined in S11 of FIG. 2, is obtained. The arithmetic expression (1) used when calculating the temperature control amount is obtained.

As described above in detail, in the polymerization reaction control device 1 and the polymerization reaction control method according to the present embodiment, the control unit 5 simultaneously confirms that the polymerization initiator is charged into the stirring tank 3 and the polymerization reaction is started. Control of the polymerization reaction is started. In the control of the polymerization reaction, when tn (30 minutes in the present embodiment) has elapsed from the start of the polymerization reaction, the cumulative drop amount n [kg] of the solvent at the time tn has been calculated (S12) and further calculated. By substituting the integrated dropping amount n into the arithmetic expression (1) obtained by performing the preliminary experiments 1 and 2 in advance, the control amount ΔSV of the temperature of the outer bath is calculated (S13). Then, by setting the calculated ΔSV to the set temperature, the temperature of the outer bath thereafter is set (S14), so that the total amount of solvent dripped before the end of the reaction is set to a preset target value. Therefore, the degree of influence on the reaction due to various variation factors such as dissolved oxygen concentration can be quantified alternatively by the cumulative amount of solvent dropped during the polymerization. Furthermore, by predicting the total dropping amount at the end of the reaction, it is possible to prevent variations in the physical properties (molecular weight) of the polymer while improving the reproducibility of the polymerization reaction.
In the preliminary experiments 1 and 2, the polymerization reaction is performed using a plurality of types of solvents A to D at different temperatures, the outer bath temperature is changed after a predetermined time from the start of polymerization, and the outer bath is changed for each type of solvent used. Calculate the temperature difference of the temperature and the total dripping amount until the end of the polymerization reaction, and calculate the temperature of the outer bath from the relationship between the temperature difference that becomes the target total dripping amount and the cumulative dripping amount of the solvent until the change of the outer bath temperature. Determine the amount of control. Thereby, by controlling the outer bath temperature, the total dripping amount of the solvent can always be kept within a certain range, and desired polymer physical properties can be obtained.
Furthermore, in the preliminary experiments 1 and 2, the polymerization reaction is performed using a plurality of types of solvents at different temperatures, and for each type of solvent used, the total amount of solvent dropped from the start of polymerization to the end of the polymerization reaction every predetermined time. The correlation with the amount is obtained, and the earliest timing at which the correlation is equal to or higher than a predetermined height and from the start of polymerization is obtained as the timing for calculating the cumulative amount of solvent. Thereby, the temperature setting range of the outer bath can be reduced when controlling the outer bath temperature, and the influence of disturbance due to control of overshoot and the like can be reduced.

Note that the present invention is not limited to the above-described embodiment, and various improvements and modifications can be made without departing from the scope of the present invention.
For example, when the present embodiment to determine the timing to calculate the cumulative dropping amount of the solvent in the pre Experiment 1, it determines the coefficient R ² indicating the correlation of the integrated dropwise and total dropping amount of the solvent is 0.9 or more the was a condition may be the condition that the coefficient of determination R ² is 0.8 or more.

It is a schematic side view which shows the principal part of the polymerization reaction control apparatus which concerns on this embodiment. It is a flowchart of the outer bath temperature control program of the stirring tank of the polymerization reaction control device according to the present embodiment. It is a flowchart of the dripping control program of the solvent of the polymerization reaction control apparatus which concerns on this embodiment. It is the figure which showed the cumulative dripping amount of the solvent at each time from the start of a polymerization reaction to completion | finish in the prior experiment 1 for every solvent AD used for experiment. It is the figure which showed the integrated dripping amount of the solvent 10 minutes after the start of the polymerization reaction in the prior experiment 1, and the total dripping amount required until the completion of the reaction for each of the solvents A to D used in the experiment. It is the figure which showed the integrated dripping amount of the solvent 20 minutes after the start of the polymerization reaction in the prior experiment 1, and the total dripping amount required until the completion of the reaction for each of the solvents A to D used in the experiment. It is the figure which showed the integrated dripping amount of the solvent 30 minutes after the start of a polymerization reaction in prior experiment 1, and the total dripping amount required until the completion of reaction for every solvent AD used for experiment. It is the figure which showed the total dripping amount of the solvent required for the external bath temperature change and the completion | finish of a polymerization reaction at the time of 30-minute progress in the prior experiment 2 for every solvent AD used for experiment. The temperature change ΔSV of the outer bath and the cumulative amount of solvent dripping after 30 minutes from the start of the polymerization reaction are shown for each of the solvents A to D used in the experiment in order to set the total dripping amount of the solvent to 350 kg in the preliminary experiment 2. It is a figure. It is the figure which showed the correlation of the total dripped amount of the solvent used for superposition | polymerization, and the produced | generated polymer molecular weight.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Polymerization reaction control apparatus 2 Stirrer 3 Stirrer tank 4 Dripping tank 5 Control part 9 Jacket

Claims (6)

Polymerization reaction control method for controlling the polymerization reaction by controlling the outer bath temperature of the stirring tank and dropping the solvent into the stirring tank in the course of synthesizing the polymer by the polymerization reaction by introducing the monomer mixture into the stirring tank In
Calculate the cumulative dropping amount of the solvent from the start of polymerization at a predetermined timing during the polymerization reaction,
A polymerization reaction control method, wherein the temperature of the outer bath is controlled based on the calculated cumulative drop amount of the solvent so that a preset total drop amount of the solvent is dropped before the end of the polymerization reaction. In the polymerization reaction control method according to claim 1,
A control amount of the temperature of the outer bath based on the cumulative dripping amount of the solvent is determined as follows.
A polymerization reaction is performed using a plurality of types of solvents at different temperatures, the outer bath temperature is changed after a predetermined time from the start of polymerization, and the temperature difference between the outer bath temperature changed for each of the used solvents and the end of the polymerization reaction are changed. Calculate the total dripping amount,
A polymerization reaction control method characterized in that a control amount of a temperature of an outer bath is obtained from a relationship between a temperature difference that becomes a target total dripping amount and an integrated dripping amount of a solvent up to a change time of the outer bath temperature. In the polymerization reaction control method according to claim 1 or 2,
Obtain the timing for calculating the cumulative amount of the solvent added as follows:
The polymerization reaction is performed using a plurality of types of solvents at different temperatures, and the correlation between the total amount of dripping of the solvent from the start of polymerization and the total amount of dripping until the end of the polymerization reaction is determined for each type of solvent used. ,
A polymerization reaction control method characterized in that the correlation is equal to or higher than a predetermined height and the earliest timing from the start of polymerization is determined as the timing for calculating the cumulative dripping amount of the solvent. A stirring tank for stirring the monomer mixture;
Outer bath temperature control means for controlling the temperature of the outer bath of the stirring tank;
Dropping means for dropping the solvent into the stirring tank,
In the process of putting the monomer mixture into the stirring tank and synthesizing the polymer by the polymerization reaction, the outer bath temperature is controlled by the outer bath temperature control means, and the solvent is dropped into the stirring tank by the dropping means. In the polymerization reaction control device for controlling the reaction,
A dropping amount calculating means for calculating the cumulative dropping amount of the solvent from the start of polymerization at a predetermined timing during the polymerization reaction;
The outer bath temperature control means controls the temperature of the outer bath based on the cumulative drop amount of the solvent calculated by the drop amount calculation means so as to drop a preset total drop amount of the solvent by the end of the polymerization reaction. A polymerization reaction control device. In the polymerization reaction control device according to claim 4,
Obtaining the control amount of the temperature of the outer bath based on the cumulative dripping amount of the solvent by the outer bath temperature control means as follows:
A polymerization reaction is performed using a plurality of types of solvents at different temperatures, the outer bath temperature is changed after a predetermined time from the start of polymerization, and the temperature difference between the outer bath temperature changed for each of the used solvents and the end of the polymerization reaction are changed. Calculate the total dripping amount,
A polymerization reaction control apparatus for obtaining a control amount of a temperature of an outer bath from a relationship between a temperature difference that becomes a target total dripping amount and an accumulated dripping amount of a solvent up to a change time of the outer bath temperature. In the polymerization reaction control device according to claim 4 or 5,
The timing for calculating the cumulative amount of solvent dripping by the dripping amount calculating means is determined as follows.
The polymerization reaction is performed using a plurality of types of solvents at different temperatures, and the correlation between the total amount of dripping of the solvent from the start of polymerization and the total amount of dripping until the end of the polymerization reaction is determined for each type of solvent used. ,
A polymerization reaction control apparatus, wherein the correlation is equal to or higher than a predetermined height and the earliest timing from the start of polymerization is determined as the timing for calculating the cumulative amount of the solvent.

Images