JP2008285565A - Apparatus for producing thermoplastic resin and method for cleaning apparatus for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for producing a thermoplastic resin capable of transferring reaction liquid even without installing a transferring device such as a pump, etc., among a multiple number of reaction vessels, and also a method for cleaning the device for producing the thermoplastic resin, capable of transferring cleaning liquid smoothly and cleaning the reaction vessels simply and easily. <P>SOLUTION: This apparatus for producing the thermoplastic resin having the multiple number of reaction vessels for performing melt polymerization and transferring pipes connecting the upstream side reaction vessel with the down stream side reaction vessel among the reaction vessels, and transferring the reaction liquid is provided with that the relationship of the positions of the upstream side reaction vessel which is an adjacent reaction vessel linked with the transferring pipe and the adjacent down stream side reaction vessel is that the vessel bottom of the upstream side reaction vessel is arranged at least a higher position than the installed position of the feeding port of the adjacent downstream side reaction vessel. Also the transferring pipe is arranged at a same height position of the installed position of the feeding port or a higher position than the installed position of the feeding port. And the cleaning is performed by making the inner pressure of the upstream side reaction vessel and of the adjacent downstream side reaction vessel as equal and transferring the cleaning liquid by the height difference of the reaction vessels. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an apparatus for manufacturing a thermoplastic resin and the like, and more particularly to an apparatus for manufacturing a thermoplastic resin and the like that can transfer a reaction liquid without providing a transfer apparatus such as a pump between a plurality of reactors.

As a method for producing a thermoplastic resin such as a polycarbonate resin, a polyester resin, or a polyamide resin, there are a batch type and a continuous type. In the case of mass-produced products, a continuous system that is advantageous in terms of quality and cost is generally adopted.
When manufacturing a thermoplastic resin in a continuous manner, particularly when manufacturing by melt polymerization, use a plurality of reactors connected in series by a transfer pipe, and change from an upstream reactor to a downstream reactor. Production is carried out by transferring the reaction liquid while sequentially proceeding the polymerization reaction toward the end, and continuously discharging the thermoplastic resin having completed the polymerization reaction from the final reactor.

  Here, in the conventional thermoplastic resin production apparatus, all the reactors are installed on a substantially horizontal plane. When the reaction liquid is transferred from the upstream reactor to the downstream reactor, it is usual to sequentially transfer the reaction liquid using a pump (for example, see Patent Documents 1, 2, and 3). .

Japanese Patent Laid-Open No. 11-236439 JP 2000-336162 A JP-A-11-310632

However, the method of transferring a reaction liquid using a pump has a problem that the manufacturing equipment becomes complicated, and the maintenance of the pump and the energy required for operation are also required.
On the other hand, it is necessary to stop the operation of the reactor and clean the reactor in order to repair and check the manufacturing equipment. For this purpose, a cleaning liquid is introduced into the reactor, and the cleaning liquid is sequentially transferred from the upstream side to the downstream reactor for cleaning. At this time, since the internal pressures of the reactors may be different from each other, there is a problem that even if the cleaning liquid is introduced, the cleaning liquid cannot be smoothly transferred from the upstream side to the downstream side reactor.

The present invention has been made in view of the above-described problems of conventional techniques.
That is, an object of the present invention is to provide a thermoplastic resin production apparatus capable of transferring a reaction liquid without providing a transfer device such as a pump between adjacent reactors.
Another object of the present invention is to provide a cleaning method for a thermoplastic resin production apparatus that can smoothly transfer a cleaning liquid and can easily clean a reactor and a transfer pipe.

  In order to solve the above-mentioned problems, the present inventors have conducted intensive studies.As a result, by arranging the position of the upstream reactor at a predetermined position higher than the position of the adjacent downstream reactor, Even if it is not used, the reaction liquid can be sequentially transferred from the upstream reactor to the downstream reactor, and in the two adjacent reactors, the internal pressure is made equal, so that the washing liquid can be changed depending on the height of the reactor. Based on this finding, the present invention has been completed.

  Thus, according to the present invention, there are provided a plurality of reactors provided with vent pipes and connected by transfer pipes, and pipes connecting the vent pipes to each other, and the plurality of reactors are the upstream reactors. The tank bottom is arranged at a position at least higher than the installation position of the supply port of the adjacent downstream reactor, and the transfer pipe is at the same height as the installation position of the supply port or higher than the installation position of the supply port. An apparatus for producing a thermoplastic resin characterized by being disposed is provided.

  The thermoplastic resin is preferably obtained by melt polymerization using any one of a polyaddition reaction, a polycondensation reaction and a transesterification reaction, and the thermoplastic resin is a polyester resin, a polyamide resin or a polycarbonate resin. More preferably, the thermoplastic resin is a polycarbonate resin obtained by an ester exchange reaction using an aromatic dihydroxy compound and a carbonic acid diester as raw materials.

On the other hand, according to the present invention, vent pipes provided in a plurality of reactors arranged with steps and connected by transfer pipes are connected to each other, and the cleaning liquid in the reactors is different in elevation between the reactors. A method for cleaning a thermoplastic resin production apparatus is provided.
Moreover, it is preferable that the step is formed by arranging the tank bottom of the upstream reactor at a position at least higher than the installation position of the supply port of the adjacent downstream reactor.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing apparatus of the thermoplastic resin etc. which can transfer a reaction liquid from an upstream reactor to a downstream reactor sequentially can be provided, without using transfer apparatuses, such as a pump.

  The best mode for carrying out the present invention (hereinafter, an embodiment of the present invention) will be described in detail below. The present invention is not limited to the following embodiments, and various modifications can be made within the scope of the invention. The drawings used are for explaining the present embodiment and do not represent the actual size.

  In order to describe a thermoplastic resin manufacturing apparatus to which the present embodiment is applied, a polycarbonate resin will be described as an example of a thermoplastic resin.

(Polycarbonate resin)
In the present embodiment, the polycarbonate resin is produced by a polycondensation reaction based on an ester exchange reaction using an aromatic dihydroxy compound and a carbonic acid diester as raw materials.
Hereinafter, a method for producing a polycarbonate resin by using an aromatic dihydroxy compound and a carbonic acid diester as raw materials and continuously performing a polycondensation reaction in the presence of a transesterification catalyst will be described.

(Aromatic dihydroxy compounds)
Examples of the aromatic dihydroxy compound used in the present embodiment include compounds represented by the following general formula (1).

Here, in the general formula (1), A is a single bond or an optionally substituted linear, branched or cyclic divalent hydrocarbon group having 1 to 10 carbon atoms, or -O-, A divalent group represented by —S—, —CO— or —SO ₂ —. X and Y are a halogen atom or a C1-C6 hydrocarbon group. p and q are integers of 0 or 1. X and Y and p and q may be the same or different from each other.

  As a specific example of the aromatic dihydroxy compound, 2,2-bis (4-hydroxyphenyl) propane (“bisphenol A”, hereinafter sometimes abbreviated as BPA) is preferable.

(Carbonated diester)
Examples of the carbonic acid diester used in the present embodiment include compounds represented by the following general formula (2).

Here, in general formula (2), A 'is a C1-C10 linear, branched or cyclic monovalent hydrocarbon group which may be substituted. Two A ′ may be the same or different from each other.
In addition, as a substituent on A ′, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a phenyl group, a phenoxy group, a vinyl group, a cyano group, an ester group, an amide group, Examples thereof include a nitro group.

  Specific examples of the carbonic acid diester include diphenyl carbonate (hereinafter sometimes abbreviated as DPC) and substituted diphenyl carbonate.

  Moreover, said carbonic acid diester may substitute the quantity of the 50 mol% or less preferably 30 mol% or less with the dicarboxylic acid or dicarboxylic acid ester preferably.

These carbonic acid diesters (including the above-mentioned substituted dicarboxylic acid or dicarboxylic acid ester; the same shall apply hereinafter) are used in excess with respect to the aromatic dihydroxy compound.
That is, it is usually used in a molar ratio of carbonic acid diester 1.01-1.30, preferably 1.02-1.20, relative to the aromatic dihydroxy compound. When the molar ratio is smaller than 1.01, the terminal OH group of the obtained polycarbonate resin increases, and the thermal stability of the resin tends to deteriorate. In addition, when the molar ratio is larger than 1.30, the transesterification reaction rate decreases, and it becomes difficult to produce a polycarbonate resin having a desired molecular weight, and the residual amount of carbonic acid diester in the resin increases. This is not preferable because it may cause odor of the molded product or the molded product.

(Transesterification catalyst)
Examples of the transesterification catalyst used in the present embodiment include a catalyst usually used for producing a polycarbonate by a transesterification method, and are not particularly limited. However, practically, an alkali metal compound is preferable, and among these, cesium is preferred. Compounds are preferred, and cesium carbonate, cesium bicarbonate, and cesium hydroxide are more preferred.
The transesterification catalyst is generally used in an amount of 1 × 10 ⁻⁹ to 1 × 10 ⁻¹ mol, preferably 1 × 10 ⁻⁷ to 1 × 10 ⁻² mol, relative to 1 mol of the aromatic dihydroxy compound. It is done.

(Production method of polycarbonate resin)
Next, the manufacturing method of polycarbonate resin is demonstrated.
In the production of polycarbonate resin, a mixture containing an aromatic dihydroxy compound and a carbonic acid diester as raw materials is prepared (primary process), and a mixture of these compounds is melted in a reactor in the presence of a transesterification reaction catalyst. Is carried out by a polycondensation reaction in a multistage manner (polycondensation step). The reaction system may be any of a batch system, a continuous system, or a combination of a batch system and a continuous system. As the reactor, generally, a plurality of vertical reactors and / or at least one horizontal reactor subsequent thereto are used. Usually, these reactors are installed in series and processed continuously.
After the polycondensation step, the reaction is stopped and the unreacted raw materials and reaction by-products in the reaction solution are devolatilized and removed, the step of adding a heat stabilizer, release agent, colorant, etc., polycarbonate resin You may add suitably the process etc. which form in the diameter pellet.
Next, each process of the manufacturing method will be described.

(Primary process)
The aromatic dihydroxy compound and carbonic acid diester used as a raw material for the polycarbonate resin are usually a batch type, semi-batch type or continuous type stirring tank type apparatus in an atmosphere of an inert gas such as nitrogen or argon. Prepared as a molten mixture. For example, when bisphenol A is used as the aromatic dihydroxy compound and diphenyl carbonate is used as the carbonic acid diester, the temperature of the melt mixing is usually selected from the range of 120 ° C to 180 ° C, preferably 125 ° C to 160 ° C.

(Polycondensation process)
The polycondensation by the transesterification reaction between the aromatic dihydroxy compound and the carbonic acid diester is usually carried out continuously in a multistage system of two or more stages, preferably 3 to 7 stages.
Specific reaction conditions are temperature: 150 ° C. to 320 ° C., pressure: normal pressure to 1.3 Pa, average residence time: 5 minutes to 150 minutes.
In each reactor when the polycondensation process is performed in multiple stages, in order to more effectively discharge the by-product phenol with the progress of the polycondensation reaction, the reaction conditions are usually higher and higher in steps. Set to vacuum. In order to prevent quality deterioration such as hue of the obtained polycarbonate resin, it is preferable to set a low temperature and a short residence time as much as possible.

  In the present embodiment, the polycondensation step is performed in a multistage manner, and a plurality of vertical reactors are provided to increase the average molecular weight of the polycarbonate resin. Usually, 2 to 6 reactors, preferably 3 to 5 reactors are installed.

In addition, the transesterification catalyst used for the polycondensation of the aromatic dihydroxy compound and the carbonic acid diester is usually prepared in advance as an aqueous solution. The concentration of the catalyst aqueous solution is not particularly limited, and is adjusted to an arbitrary concentration according to the solubility of the catalyst in water. Moreover, it can replace with water and can also use organic solvents, such as acetone, alcohol, toluene, and phenol.
The water used for dissolving the catalyst is not particularly limited as long as the kind and concentration of impurities contained are constant, but usually distilled water, deionized water, and the like are preferably used.

(Manufacturing equipment)
Next, an example of a method for producing a polycarbonate resin to which the present embodiment is applied will be specifically described with reference to the drawings.
FIG. 1 is a diagram illustrating an example of a thermoplastic resin manufacturing apparatus. In the production apparatus shown in FIG. 1, the polycarbonate resin includes a raw material process for preparing raw material aromatic dihydroxy compounds and carbonic acid diesters, and a polycondensation process in which these raw materials are polycondensed using a plurality of reactors in a molten state. It is manufactured through.
Thereafter, the step of stopping the reaction and devolatilizing and removing unreacted raw materials and reaction byproducts in the polymerization reaction solution (not shown), and the step of adding a thermal stabilizer, a release agent, a colorant and the like (not shown) ), A polycarbonate resin pellet is formed through a step (not shown) of forming a polycarbonate resin into a pellet having a predetermined particle diameter.

In the raw material preparation process, a raw material preparation tank 2 and a raw material supply pump 4a for supplying the prepared raw material to the polycondensation process are provided. In the raw material preparation tank 2, for example, an anchor type stirring blade 3 is provided.
In addition, diphenyl carbonate (hereinafter sometimes referred to as DPC), which is a carbonic acid diester, is supplied in a molten state from the DPC supply port 1a-1 to the raw material preparation tank 2, and from the BPA supply port 1b, a fragrance is supplied. Group dihydroxy compound bisphenol A (hereinafter sometimes referred to as BPA) is supplied in a powder state (or melted state), and bisphenol A is dissolved (or mixed) in the molten diphenyl carbonate.

  Next, in the polycondensation step, the thermoplastic resin production apparatus according to the present embodiment is used. A first vertical reactor 6a, a second vertical reactor 6b, a third vertical reactor 6c, and a fourth vertical reactor 6d connected in series are provided. The first vertical reactor 6a, the second vertical reactor 6b, the third vertical reactor 6c, and the fourth vertical reactor 6d are provided with stirring blades 7a, 7b, 7c, and 7d, respectively. And connected in series by transfer pipes 11a, 11b, and 11c.

Vent pipes 8a, 8b, 8c, and 8d for discharging by-products generated by the polycondensation reaction are attached to the four reactors. The vent pipes 8a, 8b, 8c, and 8d are connected to condensers 81a, 81b, 81c, and 81d, respectively, and each reactor is maintained in a predetermined reduced pressure state by a decompression device (not shown).
Moreover, piping 9a, 9b, 9c which connects vent piping 8a, 8b, 8c, 8d mutually is installed, and valve | bulb 10a, 10b, 10c is provided in piping 9a, 9b, 9c.
The positional relationship of each reactor will be described in detail later.

  In the polycarbonate resin production apparatus shown in FIG. 1, a DPC melt prepared at a predetermined temperature in a nitrogen gas atmosphere and a BPA weighed in a nitrogen gas atmosphere are respectively supplied to the DPC supply port 1a-1 and the BPA supply. It is continuously supplied to the raw material preparation tank 2 from the mouth 1b. The liquid level of the raw material preparation tank 2 is controlled to a predetermined level, and the raw material mixture is continuously supplied to the first vertical reactor 6a via the raw material supply pump 4a. As the catalyst, an aqueous cesium carbonate solution is continuously supplied from the catalyst supply port 5a in the middle of the transfer pipe of the raw material mixture.

In the first vertical reactor 6a, under a nitrogen atmosphere, for example, a temperature of 220 ° C., a pressure of 13.33 kPa, and the rotation speed of the stirring blade 7a are maintained so that the stirring power per unit volume is 0.8 kW / m ^3. The polycondensation reaction is carried out while keeping the liquid level constant so that the average residence time is 60 minutes while distilling off the phenol produced as a by-product from the vent pipe 8a. Next, the polymerization reaction liquid discharged from the first vertical reactor 6a is continuously continuously supplied to the second vertical reactor 6b, the third vertical reactor 6c, and the fourth vertical reactor 6d. The polycondensation reaction proceeds. The reaction conditions in each reactor are set so as to become high temperature, high vacuum, and low stirring speed as the polycondensation reaction proceeds. During the polycondensation reaction, the liquid surface level is controlled so that the average residence time in each reactor is, for example, about 60 minutes. In each reactor, by-produced phenol is vent piping 8a, 8b, 8c. , 8d.

  In the present embodiment, distillates such as phenol (unreacted DPC, unreacted DPC, etc.) are supplied from the condensers 81a and 81b attached to the first vertical reactor 6a and the second vertical reactor 6b, respectively. BPA and the like are also included). In the condensers 81c and 81d attached to the third vertical reactor 6c and the fourth vertical reactor 6d, the distillate is continuously condensed and solidified and recovered.

Next, the polycarbonate resin extracted from the fourth vertical reactor 6d is supplied from the outlet pipe 12 to an extruder (not shown) in a molten state. Various types of additives such as butyl p-toluenesulfonate, tris (2,4-di-t-butylphenyl) phosphite, and stearic acid monoglyceride are supplied to the extruder from the additive supply port.
The strand-like polycarbonate resin discharged from the extruder is cooled and solidified with cooling water, then pelletized with a cutter, removed with a centrifugal dehydrator (not shown), and then transported to a product silo.

Next, the positional relationship between the first vertical reactor 6a, the second vertical reactor 6b, the third vertical reactor 6c, and the fourth vertical reactor 6d will be described in detail.
FIG. 2 shows only a necessary part of the thermoplastic resin production apparatus shown in FIG. 1 in a simplified manner.
The thermoplastic resin production apparatus shown in FIG. 2 includes four vertical reactors 6a, 6b, 6c, and 6d that perform a polycondensation reaction as described above. The reactors 6a, 6b, 6c, 6d are sequentially connected in series by transfer pipes 11a, 11b, 11c.

And the positional relationship of each reactor 6a, 6b, 6c, 6d is arrange | positioned with a level | step difference, and each tank bottom of an upstream reactor is the installation position of the supply port of the adjacent downstream reactor. It is arranged at least at a higher position.
Specifically, taking the positional relationship between the first vertical reactor 6a, which is an upstream reactor, and the second vertical reactor 6b, which is an adjacent downstream reactor, the first vertical reaction is taken as an example. The tank bottom 13a of the vessel 6a is arranged at a position higher by h1 than the installation position 14b of the supply port of the second vertical reactor 6b.
Similarly, the tank bottom 13b of the second vertical reactor 6b is higher than the installation position 14c of the supply port of the third vertical reactor 6c by h2, and the tank bottom 13c of the third vertical reactor 6c. Is arranged at a position higher by h3 than the installation position 14d of the supply port of the fourth vertical reactor 6d.

In addition, the transfer pipe for sequentially connecting the upstream reactor to the downstream reactor and transferring the reaction liquid should be arranged at the same height position as the supply port installation position or higher than the supply port installation position. is required.
If there is even a portion that is lower than the installation position of the supply port, the reaction solution accumulates in that portion, making it difficult to transfer the reaction solution completely.

FIG. 3 is a diagram illustrating the positional relationship exemplified by the first vertical reactor 6a, the second vertical reactor 6b which is an adjacent downstream reactor, and the transfer pipe 11a.
In FIG. 3 (a), the tank bottom 13a of the first vertical reactor 6a is at a position higher by h4 than the installation position 14b of the supply port of the second vertical reactor 6b, and the transfer pipe 11a is supplied It is arranged at the same height position as the opening installation position 14b or higher than the supply opening installation position 14b. In this case, there is no problem in the positional relationship between the tank bottom 13a, the supply port installation position 14b, and the transfer pipe 11a.
On the other hand, in FIG. 3 (b), the tank bottom 13a of the first vertical reactor 6a is at a position lower by h5 than the installation position 14b of the supply port of the second vertical reactor 6b. There is a problem with the positional relationship of the mouth installation position 14b.
In FIG. 3 (c), the tank bottom 13a of the first vertical reactor 6a is located at a position h6 higher than the installation position 14b of the supply port of the second vertical reactor 6b. There is no problem in the positional relationship of the installation position 14b, but a part of the transfer pipe 11a has a portion that is lower by h7 than the installation position 14b of the supply port. Therefore, there is a problem in the arrangement relationship of the transfer pipe 11a.

Each reactor 6a, 6b, 6c, 6d is provided with a stirring means (stirrer), and a thermoplastic resin such as polycarbonate resin undergoes a polycondensation reaction in each reactor while being stirred by this stirring means. Let Then, after staying in the reactor for a certain period of time, it is transferred from the tank bottom of each reactor through the transfer pipe to the adjacent downstream reactor. Then, the reaction liquid that has finished the final reaction in the fourth vertical reactor 6d is transferred from the tank bottom 13d of the fourth vertical reactor 6d to the next step.
Here, as described above, since the upstream reactor is arranged at a predetermined height higher than the adjacent downstream reactor, the reaction liquid can be used without using a transfer means such as a pump. It can be transferred to the downstream reactor due to the height difference.
The above-described h1, h2, and h3 can be determined by considering the pressure loss of the reaction liquid in the transfer pipes 11a, 11b, and 11c. That is, it is necessary to install the upstream reactor at a position where the potential energy of the reaction liquid exceeds the pressure loss in the transfer pipe due to the reaction liquid. In the present embodiment, this condition can be satisfied if the tank bottom of the upstream reactor is at a position higher than the installation position of the supply port of the downstream reactor.

The height at which the upstream reactor is installed is not particularly limited as long as the tank bottom of the upstream reactor is higher than the installation position of the supply port of the downstream reactor. In fact, due to earthquake resistance, cost, and other factors, the position of the bottom of the upstream reactor is actually 1.5 times higher than the downstream reactor from the position of the downstream reactor supply port. It is preferable to keep it in position. Further, it is more preferable to keep it up to a position that is one time higher.
Moreover, in the above-mentioned example, all the reactors were saddle type, but it is not restricted to this, A horizontal type | mold other reactor may be sufficient.

In FIG. 2, as described above, each of the reactors 6a, 6b, 6c, 6d is sequentially connected from the upstream reactor to the downstream reactor, and the downstream reactor adjacent to the upstream reactor. Are provided with pipes 9a, 9b, 9c for equalizing the internal pressures of the two.
Valves 10a, 10b, and 10c are attached to the pipes 9a, 9b, and 9c.

When it is necessary to clean the inside of the reactor for inspection, repair, etc. of the reactor, all operation of the reactor is stopped, and the cleaning liquid is sequentially transferred from the upstream reactor to the downstream reactor. Clean the reactor.
Specifically, first, all the reaction liquid is extracted from each of the reactors 6a, 6b, 6c, and 6d, and the cleaning liquid is introduced into the first vertical reactor 6a.
And the 1st vertical reactor 6a is wash | cleaned by rotating the stirrer 7a of the 1st vertical reactor 6a.

Next, the second vertical reactor 6b is cleaned. At this time, the cleaning liquid needs to be transferred from the first vertical reactor 6a to the second vertical reactor 6b. If the internal pressure of the first vertical reactor 6a and the internal pressure of the second vertical reactor 6b are not equal, the cleaning liquid may not be smoothly transferred from the first vertical reactor 6a to the second vertical reactor 6b. . Therefore, the internal pressures of the first vertical reactor 6a and the second vertical reactor 6b are made equal by opening the valve 10a and using the pipe 9a.
When the cleaning liquid is transferred from the first vertical reactor 6a to the second vertical reactor 6b in this state, the transfer of the cleaning liquid is completed smoothly due to the difference in height of the reactor. At this time, the transfer tube 11a can also be cleaned.
And the 2nd vertical reactor 6b can be wash | cleaned by rotating the stirrer 7b of the 2nd vertical reactor 6b.

The procedure for washing the third vertical reactor 6c and the fourth vertical reactor 6d is the same. By using the pipe 9b and the valve 10b and the pipe 9c and the valve 10c as described above, the upstream reactor And the internal pressure of the downstream reactor adjacent thereto can be made equal, and the cleaning liquid can be transferred smoothly. After the transfer, cleaning may be performed by using the stirrers 7c and 7d of the respective reactors, and the transfer pipes 11b and 11c can also be cleaned when the cleaning liquid is transferred.
By adopting the above-described method, the cleaning liquid can be smoothly transferred, and the reactor and the transfer tube can be easily cleaned.

Heretofore, the thermoplastic resin manufacturing apparatus to which the present embodiment is applied has been described using the polycarbonate resin manufacturing apparatus as an example.
The thermoplastic resin production apparatus described in detail in the present embodiment is applicable to any thermoplastic resin production apparatus obtained by melt polymerization using a polyaddition reaction, a polycondensation reaction, or a transesterification reaction. Is possible. Specific examples of the thermoplastic resin include a polyester resin, a polyamide resin, a polycarbonate resin, and a polyarylate resin.

It is a figure which shows an example of the manufacturing apparatus of a thermoplastic resin. Only the necessary part of the thermoplastic resin production apparatus shown in FIG. 1 is shown in a simplified manner. It is the figure which illustrated each positional relationship illustrated by the 1st vertical reactor, the 2nd vertical reactor which is a downstream downstream reactor, and a transfer pipe.

Explanation of symbols

2 ... Raw material preparation tank, 3 ... Anchor type stirring blade, 4a ... Raw material supply pump, 5a ... Catalyst supply port, 6a ... First vertical reactor, 6b ... Second vertical reactor, 6c ... Third vertical reaction Vessel, 6d ... fourth vertical reactor, 7a, 7b, 7c, 7d ... stirring blade, 8a, 8b, 8c, 8d ... vent piping, 9a, 9b, 9c ... piping, 10a, 10b, 10c ... valve, 11a , 11b, 11c ... transfer pipe, 12 ... outlet pipe, 13a, 13b, 13c, 13d ... tank bottom, 14a, 14b, 14c, 14d ... installation position of the supply port, 81a, 81b, 81c, 81d ... condenser

Claims (6)

A plurality of reactors provided with vent pipes and connected by transfer pipes;
A pipe for connecting the vent pipes to each other,
The plurality of reactors are arranged at a position where the tank bottom of the reactor on the upstream side is at least higher than the installation position of the supply port of the downstream downstream reactor, and the transfer pipe is connected to the supply port An apparatus for producing a thermoplastic resin, wherein the apparatus is arranged at the same height position as the installation position or higher than the installation position of the supply port.   The apparatus for producing a thermoplastic resin according to claim 1, wherein the thermoplastic resin is obtained by melt polymerization using any one of a polyaddition reaction, a polycondensation reaction, and a transesterification reaction.   The said thermoplastic resin is any one of a polyester resin, a polyamide resin, a polycarbonate resin, and a polyarylate resin, The manufacturing apparatus of the thermoplastic resin of Claim 2 characterized by the above-mentioned.   The said thermoplastic resin is a polycarbonate resin obtained by transesterification which uses an aromatic dihydroxy compound and a carbonic acid diester as a raw material, The manufacturing apparatus of the thermoplastic resin of Claim 3 characterized by the above-mentioned. Vent pipes provided in a plurality of reactors arranged with steps and connected by transfer pipes are connected to each other,
A cleaning method for a thermoplastic resin production apparatus, wherein the cleaning liquid in the reactor is transferred by a height difference between the reactors.   The said level | step difference is made by arrange | positioning in the position where the tank bottom of the said reactor of the upstream is at least higher than the installation position of the supply port of the said downstream downstream reactor, The said level | step difference is made. A method for cleaning an apparatus for manufacturing a thermoplastic resin.

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