JPH1192555A - Production of polyester and apparatus thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a continuous production process and apparatus capable of reacting more efficiently for a polyester polymer of high quality using three reactions, and to obtain such a continuous production process for a polyethylene terephthalate that the number of the reactors necessary for the reaction is made minimum and the consumed agitation power necessary for the reaction is made minimum. SOLUTION: A polyester production apparatus is made to comprise three vessels of an esterification reactor 33, an initial polymn. reactor 37, and a final polymn. reactor 41, and is completed by furnishing a reactor each not having an external agitation power source for the esterification reactor and initial polymn. reactor, and a horizontal single axis-style, low speed revolution-type reactor for the final polymn. reactor. The necessary minimum reactor constitution produces a polyester polymer of high quality at a good efficiency at a lowest energy cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for continuously producing polyester polymers such as polyethylene terephthalate and polybutylene terephthalate.

[0002]

2. Description of the Related Art Conventionally, as a method for producing a polycondensation polymer such as polyethylene terephthalate, terephthalic acid and ethylene glycol as raw materials are put into a mixing tank at an appropriate ratio for esterification and esterified by a pump. Send to reaction tank. In this esterification step, two or three stirring tanks with stirring blades are arranged in series, and water produced as a by-product is separated by a distillation column. Next, a plurality of vertical stirring tanks and horizontal stirring tanks are installed as a pre-polymerization step, and a horizontal stirring tank is installed as a final polymerization step. A condenser is installed in the tank for these polymerization steps to remove ethylene glycol as a by-product, and the vessel is operated in a reduced pressure atmosphere. In the conventional polyester production process, the number of reaction vessels is 4 to 6 cans, each reaction vessel is equipped with a stirring blade and its power source, and a distillation column and a condenser for separating and removing by-products are installed. ing. Further, since the polymerization process is operated in a reduced-pressure atmosphere, the vacuum means must be operated by another apparatus, and the operation of the production apparatus requires high maintenance costs and equipment costs.

[0003]

SUMMARY OF THE INVENTION The problem of the present invention is an improvement over known processes for the production of high molecular weight polyesters, which increases the efficiency of the entire apparatus and saves energy in plant equipment, thereby operating economically. Is what you do.

An object of the present invention is to improve the above prior art,
An object of the present invention is to provide a continuous polycondensation apparatus and a continuous polycondensation method for efficiently reacting a high-quality polymer with minimum energy by using a minimum necessary reactor configuration.

[0005]

The object of the present invention is to provide an esterification step, a pre-polymerization step, and a final polymerization step as one tank,
A vessel requiring stirring power is achieved by only the final polymerization step.

[0006]

FIG. 1 shows an embodiment of the present invention.
FIG. 1 is an apparatus configuration diagram of a continuous production process of polyethylene terephthalate according to the present invention. As the industrial polyester production method, the direct esterification method is very economically advantageous, and thus the direct esterification method has recently been widely used. In the figure, reference numeral 31 denotes a raw material adjusting tank for mixing and stirring TPA (terephthalic acid) and EG (ethylene glycol) as raw materials of polyethylene terephthalate at a predetermined ratio. During the production process, additives such as a polymerization reaction catalyst, a stabilizer, and a color tone adjuster may be added at this stage. Examples of the polymerization reaction catalyst include metal compounds such as antimony, titanium, germanium, tin, and zinc.Depending on the type and combination of the catalysts used, not only the reaction rate differs, but also the hue and thermal stability of the resulting polyester. It is well known that they are different. Furthermore, these reactions are carried out at a high temperature for a long time in the presence of a catalyst, and are accompanied by various side reactions, and the polymer is colored yellow, and the content of diethylene glycol (DEG) and the terminal carboxyl group concentration are more than appropriate values. And physical properties such as a decrease in the melting point and strength of the polyester are reduced. Attempts have been made to develop new catalysts in order to solve such problems, but antimony compounds which are currently most industrially used, especially antimony triacid, are excellent in price and performance. However, even if this catalyst is used, coloring of the produced polyester polymer cannot be avoided. For this reason, phosphorus stabilizers (for example, trimethyl phosphate, triphenyl phosphate) have been used in combination as stabilizers for improvement. In another manufacturing process, the quality is stabilized by devising a position where a polymerization catalyst and a stabilizer are charged. In a typical process, it is preferable to use 200 to 400 ppm of the catalyst and 50 to 200 ppm of the stabilizer. The raw material adjusted as described above passes through a supply line 32 that supplies the raw material to the esterification reaction tank 33. The outer periphery of the esterification reaction tank (first reactor) 33 has a jacket structure (not shown) in order to keep the processing liquid at the reaction temperature. An exchanger 34 is provided to heat the processing liquid by a heat source from the outside, and to proceed the reaction while circulating the internal liquid by natural circulation. Here, the most desirable type of reactor is a calandria type in which the processing solution in the reactor is naturally circulated by utilizing the evaporating action of a by-product produced by the self-reaction of the esterification reaction. Since this type of reactor does not require an external stirring power source, there is an advantage that the apparatus configuration is simple, the shaft sealing device for the stirring shaft is not required, and the production cost of the reactor is low. As an example of such a reactor, an apparatus as shown in FIG. 2 is desirable. FIG. 2 shows an embodiment of the present apparatus. The liquid to be treated 52 flows from an inlet 53 provided at a lower portion in the vertical evaporator 1, flows through a plurality of heat transfer tubes (not shown) of the multi-tube heat exchanger 4, is heated, and is subjected to natural convection. To rise. Here, a part of the low boiling point component of the liquid to be treated 52 evaporates and is discharged from the vapor pipe 55 to the outside of the apparatus. The remaining liquid to be treated 52 flows down by natural convection between the inner wall of the evaporator 51 and the outer wall of the shell of the multitubular heat exchanger 54, and the cylindrical liquid provided at the lower part of the shell of the multitubular heat exchanger 4 Flows into the approach space 56 of. Here, the flow of the processing liquid is rectified with less turbulence, and the average flow velocity in the tubes of the multi-tube heat exchanger 54 is increased more than the average flow velocity flowing down by natural convection, so that a more uniform velocity is obtained. The liquid flows into the plurality of heat transfer tubes in a distribution, and each liquid to be treated is heated again uniformly and repeats circulation by natural convection. In this process, the components having a low boiling point gradually evaporate, and after a suitable convection time, the liquid to be treated 59 which is concentrated is led out of the system through the outlet 60. Here, in order to generate a smooth accelerated flow, the flow passage area of the cylindrical approach space is designed to be larger than the total flow passage area of the heat transfer tubes, and furthermore, the multi-tube heat exchange with the inner wall of the evaporator 51 is performed. This is achieved by making the flow area of the double pipe portion formed between the outer wall of the shell of the vessel 54 and the flow path area of the entrance space larger. Reference numeral 57 denotes an inlet for the heat medium, and 58, an outlet for the heat medium. The evaporator 51 is surrounded by a heat insulating material or a jacket (not shown). Therefore, in the evaporator of the present embodiment, the velocity distribution is uniform along the axial direction of the heat exchanger, so that the liquid to be treated can more uniformly evaporate or react, and a better product quality can be obtained with a short residence time. There is an effect that can be obtained. Even when the liquid to be treated 52 is a mixture of solid particles and a liquid (hereinafter, referred to as a slurry), the liquid to be treated 52 that naturally circulates is formed into a cylindrical approach space 56 provided at the lower part of the shell of the multi-tubular heat exchanger 54. , But rises more smoothly along the conical member 62 so that solid particles do not settle to the bottom. When the liquid to be treated is a slurry, by providing a conical member at the bottom of the evaporator for raising the liquid to be circulated internally, the solid particles contained in the slurry can be prevented from settling. here,
The conical member may have a certain curvature. Therefore,
The evaporator of the present embodiment has an effect of providing a suitable evaporator by natural circulation of the slurry, and a reliable and good quality product can be obtained. However, the present invention is not limited to this apparatus, and a reactor having a stirring blade may be used for process reasons. First
In the reactor, the water generated by the reaction becomes steam, and forms the vapor phase 5 with the vaporized EG vapor. The recommended reaction conditions at this time are as follows.
A pressure condition of 0 degrees is desirable. The gas in the gas phase 5 is separated into water and EG by a rectification tower (not shown) provided on the upstream side, the water is removed outside the system, and the EG is returned to the system again. As an advantage of the present invention, it is possible to reduce the number of rectification towers by treating the esterification step in one reactor, and not only the production cost of the rectification tower but also the control of the number of pipes and valves. The number and the like can be reduced, resulting in a significant reduction in equipment cost. The processing solution having passed a predetermined reaction time in the esterification reaction tank 33 reaches a predetermined esterification rate, and
Is supplied to the initial polymerization tank (second reactor) 37. At this time, the treatment liquid is heated to a predetermined reaction temperature by the heat exchanger 38 to cause a polycondensation reaction to increase the degree of polymerization. The reaction conditions at this time are 270 to 290 degrees and the pressure is 26.
The reaction is performed at a polymerization degree of about 20 to 40 at 6 Pa to 133 Pa. Although the initial polymerization tank shown in this example is described using a reactor having no stirring blade, this reactor is not limited. However, in the initial polymerization stage, the reaction is a stage in which the polymerization reaction rate is governed by the reaction speed, and the reaction proceeds smoothly if a sufficient amount of heat required for the reaction is supplied. From this viewpoint, the processing liquid does not need to be subjected to unnecessary stirring action by the stirring blade, and EG generated by the polycondensation reaction only needs to be released from the system. As an optimal reactor for such an operation, an apparatus as shown in FIG. 3 is desirable.
In the figure, reference numeral 71 denotes a vertically cylindrical container main body, the outer periphery of which is covered with a heat medium jacket 72, and a downcomer pipe 73 whose upper part is opened in the central longitudinal direction of the main body 71 is attached. Body 7
A plurality of heat transfer tubes 74 are attached to the inner lower portion of the tube 1 in parallel with the downcomer tube 73, and a plurality of spiral baffle plates 75 are attached to the outer side of the downcomer tube 73 above the heat transfer tube 74. Each baffle 75 is a gap between the inner wall of the main body 71 and the volatile substance.
The inside of the main body 71 is partitioned in the up and down direction with the inside 83, and a plurality of retention chambers 84 are formed. The upper part of the main body 71, that is, the upper end of the downcomer pipe 73 and the uppermost baffle 75C has a space 76 for separating the liquid to be treated and the volatile matter. Further, a plurality of tapered liquid receivers 88 are attached inside the descending pipe 73 for allowing the liquid to be treated to flow down the thin film inside the descent penetrator 73. Since the liquid can be successively moved downward while being held in the receiver 88, the number of short paths of the liquid to be treated can be reduced, and the reaction can proceed by evaporating and separating volatiles efficiently. In such an apparatus, the liquid to be treated continuously supplied from the inlet nozzle 77 first enters the heat transfer tube 74, rises while being heated, and reaches the lowermost retention chamber 84A. This staying room 8
The polycondensation reaction proceeds while gradually ascending 4A, and the generated volatile matter such as ethylene glycol moves upward from the gap 83 outside the baffle plate 75. On the other hand, the liquid to be treated is the baffle plate 7
5 while raising a swirling flow along the spiral portion of No. 5, and flows into the next staying chamber 84B. At this time, the liquid moves smoothly to the next retention chamber 84B while turning, so that the backflow is less likely to occur, and the liquid to be treated sequentially rises in the retention part, and the polycondensation reaction proceeds efficiently.

The liquid to be processed reaches the uppermost retaining chamber 84C in this manner, passes over the top 82 of the downcomer 73, and flows down inside the downcomer 73. The liquid to be treated flows down as a thin film inside the downcomer 73, and volatiles generated by the reaction are evaporated and separated, so that the polycondensation reaction can be further advanced.
In this manner, the volatile substances are evaporated and separated, and the liquid to be treated after the reaction is discharged from the outlet nozzle 78 to the outside of the system. On the other hand, the generated volatiles are treated liquid (polymer) in the upper space 6 in the main body.
And is discharged out of the system from the outlet nozzle 79 of the volatile matter.

At this time, the problem that the liquid to be treated (polymer) accompanies the volatile substance, that is, the entrainment is liable to occur, but in the present invention, the liquid to be treated and the volatile substance bumping upward due to the spiral baffle plate 75 are circulated. It can be directed in the direction, and can suppress droplet entrainment. Volatiles, EG, generated by such a device are vaporized in the gas phase 9 maintained in a reduced-pressure atmosphere, condensed by a condenser provided on the upstream side thereof, and then discharged out of the system. As an advantage of the present invention, it is possible to reduce the number of condensers by processing the initial polymerization step in one reactor, thereby reducing not only the production cost of the condenser but also the number of piping and valves and the number of control devices. As a result, the cost of the apparatus is greatly reduced. The treatment liquid after a predetermined reaction time in the initial polymerization tank (second reactor) 37 is supplied to the final polymerization machine (third reactor) 41 through the communication pipe 40. In the final polymerization machine, a stirring blade 42 having no stirring shaft at the center
The polycondensation reaction is further promoted while receiving a better surface renewal action, thereby increasing the degree of polymerization to produce a polymer having a desired degree of polymerization. As the most suitable apparatus as the final polymerization machine (third reactor), the apparatuses shown in FIGS. 4 and 15 have the best surface renewal performance and power consumption characteristics. Further, since the viscosity range of the processing liquid is wide, the processing which has been conventionally performed by dividing the processing liquid into two tanks can be performed by one apparatus, and the cost of the apparatus can be greatly reduced. The final polymerization machine will be described with reference to FIG. FIG. 4 is a front view showing a longitudinal section of the device of the present invention. In the figure,
Reference numeral 1 denotes a horizontally long cylindrical container body whose outer periphery is covered with a heat medium jacket (not shown), and shafts 3a and 3b for rotation support are attached to both ends in the longitudinal direction. A stirring rotor 4 is mounted between the rotation supporting shafts 3a and 3b, and one of the rotation shafts 3a is connected to a driving device (not shown). The stirring rotor 4 has rotor support members 2a, 2b connected to 5a, 5b, 5c, 5d (in this embodiment, four are shown, but the number used is determined by the size of the rotor) at both ends. A stirring rotor 4 composed of a plurality of stirring blocks is formed between the supporting members 2a and 2b.
The support member 2a is a low viscosity side member, and 2b is a high viscosity side support member. The support member 2b is configured to be smaller than the outer diameter of the agitation rotor 4, and oyster members 13a and 13b are provided on the side of the main body of the support member, and the processing liquid on the side wall surface of the main body is pushed to the outer peripheral portion by rotation of the rotor. So that it is attached. FIG. 1 showing a detailed configuration of the EE section of FIG.
It is shown in FIG. The stirring rotor 4 has a low-viscosity stirrer block having a low-viscosity region on the inlet nozzle 11 side constituted by a bucket portion composed of oyster plates 6a and 6b, a thin disk 7a for pouring the processing liquid from the bucket portion, and a hollow disk 8. (The detailed structure will be described with reference to FIGS. 5, 9, and 10). Next, in the medium viscosity region, a hollow disk 8 is arranged on both sides, a plurality of hollow thin plates 7b having the same outer diameter are provided therein, and a plurality of oyster plates 6c penetrating these members are further radially provided on the outer peripheral portion. A medium-viscosity stirrer block (detailed structure will be described with reference to FIGS. 3, 4, 8, and 9) is provided. Further, on the outlet side, a plurality of wheel-shaped disks 9 are installed at appropriate intervals, and an oyster plate 10 is installed on the outer periphery of the wheel-shaped disks 9 to provide a high-viscosity stirring block (see FIG. 13 will be described. Further, an outlet nozzle 11 for the liquid to be treated is attached to the lower end of the other end of the main body 1. Further, a volatile matter outlet nozzle 14 is provided at an upper portion of the main body 1 and connected to a condenser and a vacuuming device (not shown) by piping.

In such an apparatus, the inlet nozzle 11
The low-viscosity liquid to be treated (prepolymer) supplied more continuously and having a low degree of polymerization is first stirred in a low-viscosity stirring block shown in FIG. The viscosity of the processing liquid at this time is several Pas to several tens Pas. Low viscosity stirring block is hollow disk 8
The bucket is formed by the oyster plates 6a and 6b on the outer peripheral portion of.
When it rotates as shown in the figure, it operates to scoop up the processing liquid in the bucket. FIGS. 9 and 10 schematically show the flow state of the processing liquid at this time. Oyster board 6
Small gaps δ are formed at the bottoms of the buckets a and 6b. For this purpose, the low-viscosity processing liquid 91 is picked up by the bucket with the rotation of the stirring rotor (100 in FIG. 9), the bucket is tilted inward by the rotation, and the processing liquid flows out toward the inside (101 in FIG. 9), and also to the outside. Leak little by little (102 in FIG. 9), and apply the liquid film 1 to both the inside and outside of the bucket.
01 and 102 are formed. Further, the processing liquid 101 that has flowed inward is poured into the thin disk 7a provided at the tip of the inner bucket (103 in FIG. 10), and the surface of the thin disk 7a and the thin disk 7a and the thin disk 7a A thin liquid film is formed on both sides, and a wide evaporation surface area can be secured. These actions are repeated every time the bucket rotates, and a sufficient evaporation surface and a good surface renewal action can be obtained. At this time, the rotation speed is 0.5 to several rpm (10 rpm).
pm or less), a sufficiently good performance can be obtained, and a great effect can be obtained in reducing the power consumed by stirring. The by-product evaporated from the processing liquid passes through the hollow portion 20a of the hollow disk 8 and the hollow portion 20a of the thin disk 7a, and is discharged from the outlet nozzle 14 for volatile substances. The treatment liquid having passed a predetermined residence time in the low-viscosity stirring block raises the viscosity to about several tens Pas and reaches the next medium-viscosity stirring block. 6 and 7 show the detailed structure of the medium viscosity stirring blade block. The medium viscosity stirring blade block is composed of a hollow disk 8, a thin hollow disk 7b, and an oyster plate 6c, and has a hole diameter D1 of the hollow disk and a hole diameter D3 of the thin disk 7b.
Is determined so as to have an optimum diameter in accordance with the amount of the reaction by-product gas in the processing solution. The optimum diameter of the hole diameter D2 of the thin disk 7b is also determined according to the viscosity of the processing liquid and the amount of the reaction gas. As shown in FIGS. 11 and 12, the processing liquid 92 that has reached several tens Pas is lifted up by the oscillating plate 6c by rotation, and the oscillating plate is inclined by the rotation, so that the liquid hangs down to form a liquid film 104. The liquid film 104 hangs on the connection strength member 5a of the stirring rotor with rotation, and the liquid film is held for a long time. The hollow portion 20a of the hollow disk 8
The processing liquid dragged by the rotation also hangs down inside the liquid crystal to form a liquid film 105. The liquid film 107 is also formed on the thin disk 7b in the same manner, but the processing liquid further drips into the small holes 20b provided on the thin disk 7b.
6 is formed. While forming such a liquid film, the treatment liquid further increases the degree of polymerization due to a large evaporation surface area and a good surface renewal action, and the viscosity of the treatment liquid increases. When the viscosity of the treatment liquid reaches several hundred Pas, it is treated by the next high viscosity stirring block. In the stirring block for high viscosity, an oyster plate 10a is attached to an outer peripheral portion of a wheel-shaped disk 9 as shown in FIG. Such wheel-shaped discs 9 are connected in a horizontal direction at predetermined intervals by stirring strength members 5a, 5b, 5c, and 5d. At this time, the oyster plates before and after the wheel-shaped disk 9 are installed alternately as 10a and 10b. The entire inner wall is scraped. As shown in FIG. 13, the processing solution 93 having reached several hundred Pas is rotated by the stirring blades so that
Lift the liquid by a. The lifted processing liquid is dripped by rotation to form a liquid film 108. At this time, a liquid film 109 is also formed in the hollow portion of the wheel-shaped disc 9 to create a complicated liquid surface shape. When the viscosity of the processing liquid further increases and reaches several thousand Pas, the amount of the liquid lifted increases. If the number of revolutions is increased in such a state, a rotating phenomenon occurs in which the processing liquid is stirred up again before the treatment liquid drips. Therefore, it is necessary to operate at a number of revolutions of 10 rpm or less. The optimum operating range needs to be lowered as the viscosity of the processing solution increases, and in our experiments, the optimum range was 0.5 to 6 rpm. As described above, the stirring and the surface renewal action are repeated to promote the polycondensation reaction.
The volatiles generated by the reaction move sequentially in the longitudinal direction in the main body 1 through the hollow portion of the hollow disk and are discharged from the volatile matter nozzle 14 to the outside of the system. The liquid to be treated having a high degree of polymerization and a high viscosity is discharged from the outlet nozzle 12 to the outside of the system. At this time, the processing liquid having a high viscosity accumulates in the upper portion of the outlet nozzle 12, but the support member 2 of the stirring rotor 2
Since the outer diameter b is smaller than the outer diameter of the stirring rotor 4, it does not adhere to the support member 2b. Also, the oyster members 13a and 13b are attached to the side surface of the main body 1 of the support member 2b, and the processing liquid is pressed against the outer peripheral portion of the main body. Therefore, the side wall surface of the main body is always self-cleaned, thereby preventing the accumulation of adhesion.

In the case of polymerizing polyethylene terephthalate with such an apparatus, an intermediate polymer of the liquid to be treated is continuously supplied from an inlet nozzle 11 and the surface is renewed by stirring with a stirring rotor 4 to carry out the polymerization reaction. The resulting volatile matter such as ethylene glycol is removed by evaporation, and the polycondensation reaction proceeds to form a polymer having a high viscosity. Volatile substances such as ethylene glycol separated during this time are discharged from the outlet nozzle 14. The operating conditions at this time are, for example, a liquid temperature of 260 to 300 ° C. and a pressure of 0.01 to 10 k.
It is performed in the range of Pa and the number of rotations of 1 to 10 rpm. Then, the polymer is discharged from the outlet nozzle 12 to the outside of the system. At this time, the polymer is stirred in the main body 1 in a substantially completely self-cleaning state and undergoes good surface renewal, so that a high quality product polymer can be efficiently obtained without deterioration due to stagnation. Similarly, the present apparatus can be applied to continuous bulk polymerization of polycondensation resins such as polyethylene naphthalate, polyamide, and polycarbonate. Although the final polymerization machine in FIG. 15 has the same basic configuration as the apparatus shown in FIG. 4, when the viscosity of the processing liquid at the inlet is relatively high, the embodiment of the apparatus in which the low-viscosity blade is omitted is shown. It is a thing. In addition, the stirring block for high viscosity is provided with a plurality of wheel-shaped disks 9 at appropriate intervals, and an oyster plate 200 is connected to the outer periphery of the wheel-shaped disks 9 to form the next wheel-shaped disk. The oscillating plate 200 between the plates 9 is such that a mounting position is shifted to form a high viscosity stirring block.

When polyethylene terephthalate is manufactured in the above-described apparatus configuration, the number of reactors is reduced as compared with the conventional apparatus configuration, so that the cost of the apparatus can be saved. The advantage is that the number of distillation columns and condensers to be used can be reduced, and piping, instrumentation parts, and valves that connect them can be greatly saved, and the running costs can be reduced because utility-related costs such as vacuum sources and heating medium devices are greatly reduced. There is.

[0012]

According to the present invention, the continuous production equipment for polyester is made up of three reactors of an esterification step, a pre-polymerization step and a final polymerization step, so that the efficiency of the whole apparatus is improved and the energy of the factory equipment is improved. It operates more economically with savings.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of a continuous production process of polyethylene terephthalate according to the present invention.

FIG. 2 is a cross-sectional view for convenience showing an embodiment of the evaporator according to the present invention.

FIG. 3 is a longitudinal sectional front view showing one embodiment of the present invention.

FIG. 4 is a vertical sectional front view showing one embodiment of the present invention.

FIG. 5 is a sectional view taken along line AA of FIG. 4;

FIG. 6 is a sectional view taken along line BB of FIG. 1;

FIG. 7 is a sectional view taken along line CC of FIG. 4;

FIG. 8 is a sectional view taken along line DD of FIG. 4;

FIG. 9 is a schematic diagram of a flow of a processing liquid in a bucket portion of a low-viscosity stirring block.

FIG. 10 is a schematic diagram of a flow of a processing liquid near a thin disk of a low-viscosity stirring block.

FIG. 11 is a schematic diagram of a flow of a processing liquid near a hollow disk of a medium viscosity stirring block.

FIG. 12 is a schematic diagram of a flow of a processing liquid in a thin disk shape of a medium viscosity stirring block.

FIG. 13 is a schematic diagram of a flow of a processing liquid in a high-viscosity stirring block.

FIG. 14 is a sectional view taken along line EE of FIG. 4;

FIG. 15 is a longitudinal sectional front view showing one embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Container main body, 3a, 3b ... Rotation support shaft, 4 ... Stirring rotor, 5a, 5b, 5c, 5d ... Stirring member for stirring rotor construction, 2a, 2b ... Rotor support member, 6a, 6b,
6c: oyster plate, 7a, 7b: thin disk, 8: hollow disk, 9: wheel-shaped disk, 10, 10a, 10b: oyster plate, 11: inlet nozzle, 12: outlet nozzle, 13a, 1
3b ... Oyster member, 14 ... Volatile outlet nozzle, 20
a, 20b, 20c: hollow portion, 91, 92, 93: treatment liquid level, 100, 101, 102, 103, 104, 1
05, 106, 107, 109, 110 ... liquid film, 200
... Okitori plate, 31 ... Raw material adjusting tank, 32 ... Raw material supply line, 33 ... Esterification reaction tank, 34 ... Heat exchanger, 35 ...
Gas phase part, 36 ... Connecting pipe, 37 ... Initial polymerization tank, 38 ... Heat exchanger, 39 ... Gas phase part, 40 ... Connecting pipe, 41 ... Final polymerization machine, 42
... stirring blades, 43 ... polymer, 44 ... stirring power source, 51 ... evaporator, 52 ... liquid to be treated, 54 ... multi-tube heat exchanger, 56 ...
Running space, 62: conical member, 71: container body, 72 ...
Heat medium jacket, 73 ... downcomer, 74 ... heat transfer tube, 75 ...
Spiral baffle plate, 76: volatile matter separation space, 77: inlet nozzle of liquid to be treated, 78: outlet nozzle of liquid to be treated, 79 ...
Volatile outlet nozzle.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroo Suzuki 794, Higashi-Toyoi, Kazamatsu, Kudamatsu, Yamaguchi Prefecture Inside the Kasado Plant of Hitachi, Ltd. Inside the Kasado Plant of Hitachi, Ltd.

Claims (18)

[Claims] 1. A first reactor for producing an oligoester or polyester having an average degree of polymerization of 3 to 7 or less by reacting an aromatic dicarboxylic acid or a derivative thereof with a glycol, Average degree of polymerization 20 to 40
A polyester is produced by using a second reactor for producing a low-polymerized product of the above, and a third reactor for further polycondensing the low-polymerized product and polycondensing from an average degree of polymerization of 90 to 180 to produce a high-molecular-weight polyester. In the method, at least one or more of the first and second reactors is a reactor having no stirring function by an external power source, and the method for continuous production of polyester. 2. A first reactor in which an aromatic dicarboxylic acid or a derivative thereof is reacted with a glycol to produce an oligoester or polyester having an average degree of polymerization of 3 to 7 or less. Average degree of polymerization 20 to 40
A polyester is produced by using a second reactor for producing a low-polymerized product of the above, and a third reactor for further polycondensing the low-polymerized product and polycondensing from an average degree of polymerization of 90 to 180 to produce a high-molecular-weight polyester. In the method, the third reactor has an inlet and an outlet for the liquid to be treated at one lower end and the lower end at the other end in the longitudinal direction of the horizontal cylindrical container body, has an outlet for volatiles at the upper part of the main body, A device equipped with a stirring rotor that rotates close to the inside of the main body in the longitudinal direction, and the stirring rotor inside the main body is composed of a plurality of stirring blade blocks according to the viscosity of the processing liquid, and rotates at the center of the stirring rotor. A continuous method for producing polyester, which is a reactor having a stirring blade without a shaft. 3. The method for continuously producing a polyester according to claim 1, wherein the molar ratio of the aromatic dicarboxylic acid or its derivative as a raw material to the glycol is 1: 1.0.
5 to 1: 2.0, and the temperature of the first reactor is 2
40 degrees to 285 degrees, the pressure is 3 × 10 ⁵ Pa from atmospheric pressure,
The temperature of the second reactor is 250 to 290 degrees, the pressure is 133 Pa from the atmospheric pressure, and the temperature of the third reactor is 270 to 290.
A method for continuously producing a polyester, wherein the method is operated at a temperature and pressure in the range of 200 to 13.3 Pa. 4. A continuous production method of a polyester according to claim 3, wherein the rotation speed of the stirring blade of the third reactor is 0.5.
A continuous method for producing polyester, wherein the speed is from 10 rpm to 10 rpm. 5. The method for continuously producing polyester according to claim 1, wherein the total reaction time of the first reactor, the second reactor, and the third reactor is operated between 4 and 8 hours. Continuous production method of polyester. 6. A first reactor for producing an oligoester or polyester having an average degree of polymerization of 3 to 7 or less by reacting an aromatic dicarboxylic acid or a derivative thereof with a glycol, and polycondensing the product. , Average degree of polymerization 20 to 4
And a third reactor for producing a high-molecular-weight polyester by subjecting the low-polymerized product to further polycondensation and polycondensing from an average degree of polymerization of 90 to 180 to produce a high-molecular-weight polyester. At least one reactor of the reactor and the second reactor is a reactor having no stirring function by an external power source, and is a continuous production apparatus for polyester. 7. A first reactor for producing an oligoester or polyester having an average degree of polymerization of 3 to 7 or less by reacting an aromatic dicarboxylic acid or a derivative thereof with a glycol, and polycondensing the resulting product. , Average degree of polymerization 20 to 4
And a third reactor for producing a high-molecular-weight polyester by polycondensing the low-polymer and further polycondensing the average polymerization degree from 90 to 180. The three reactors have an inlet and an outlet for the liquid to be treated at one end lower part and the other end lower part in the longitudinal direction of the horizontal cylindrical container body, respectively, have an outlet for volatile substances at the upper part of the body, and have a main body in the longitudinal direction inside the body. The stirring rotor inside the main body is provided with a plurality of stirring blade blocks according to the viscosity of the processing liquid, and does not have a rotating shaft at the center of the stirring rotor. A continuous production apparatus for polyester, which is a reactor having stirring blades. 8. The molar ratio of the starting material aromatic dicarboxylic acid or derivative thereof to glycols is from 1: 1.05 to 1: 1.
A mixture in the range of 2.0 is supplied, and the temperature is between 240 ° C and 2 ° C.
A first reactor in which a reaction is performed at a temperature of 85 ° C. and a pressure of 3 × 10 ⁵ Pa from the atmospheric pressure, and a reactant from the first reactor are supplied. The temperature is 250 to 290 ° C., and the pressure is A second reactor in which the reaction is carried out under a condition of from atmospheric pressure to 133 Pa, a reactant from the second reactor, and a temperature of 27
An apparatus for continuously producing polyester, comprising: three reactors in which a reaction is performed under the conditions of 0 to 290 degrees and a pressure of 200 to 13.3 Pa. 9. A process for producing a high-molecular-weight polyester from an aromatic dicarboxylic acid or a derivative thereof and a glycol, which is used in a final reaction stage, and is covered at one lower end and at the lower end in the longitudinal direction of a horizontal cylindrical container body, respectively. It has an inlet and an outlet for the processing liquid, and has an outlet for volatiles at the top of the main body,
A device provided with a stirring rotor that rotates close to the inside of the main body in the longitudinal direction inside the main body, wherein the stirring rotor inside the main body is composed of a plurality of stirring blade blocks according to the viscosity of the processing liquid, and the center of the stirring rotor is A reactor for continuous production of polyester, comprising a stirring blade having no rotating shaft in a part. 10. A lower end and a lower end of a substantially horizontal cylindrical container body used in a final reaction stage of a process for producing a high molecular weight polyester from an aromatic dicarboxylic acid or a derivative thereof and a glycol. The inside of the main body of the device having a stirring rotor which has an inlet and an outlet for the liquid to be treated, has an outlet for volatile substances at the top of the main body, and rotates in the longitudinal direction inside the main body and close to the inside of the main body. The rotor is composed of a plurality of stirring blade blocks in accordance with the viscosity of the processing liquid, and a stirring rotor having no rotating shaft at the center of the stirring rotor has an outer end plate connecting the power transmission shafts at both ends and the stirring rotor section. A reactor for continuous production of polyester characterized in that the diameter is smaller than the outer diameter of the stirring rotor. 11. The reactor according to claim 10, wherein a plurality of stirring blocks connected for low-viscosity stirring are provided on the inlet side, and each stirring block has a hollow disk provided at both ends; The bucket is provided on the outer periphery of the disk, and comprises a bucket portion for scooping up the processing liquid by the oyster plate, and a hollow thin disk placed close to the inner peripheral end surface of the oyster plate. A reactor for continuous production of polyester, having a structure in which a pooled treatment liquid is poured into a hollow thin disk and a liquid film is formed between the thin disks. 12. The polyester continuous as claimed in claim 11, wherein said bucket portion is provided with a hole or a slight gap through which a processing liquid flows out at a horizontal joint portion of the bottom plate. Production reactor. 13. The reactor according to claim 10, further comprising a plurality of connected stirring blocks for medium viscosity stirring, wherein each of the stirring blocks has a hollow disk provided at both ends and an outer periphery of the disk. The part consists of a plurality of oyster plates provided radially, and a hollow thin plate having the same size as the outer periphery of the plurality of disks provided between the hollow disks, and a plurality of small circular holes are formed in the thin plate. A reactor for continuous production of polyester. 14. A reactor according to claim 10, wherein a stirring block is provided for high-viscosity stirring, and the stirring block comprises a plurality of wheel-shaped disks with an oyster plate arranged horizontally. And a reactor for continuous production of polyester, wherein the front and rear oyster plates are attached alternately. 15. The reactor according to claim 10, wherein the outer diameter of the high-viscosity side supporting member connecting the stirring rotor portion is smaller than the outer diameter of the stirring rotor, and between the side surface of the supporting member and the inner end surface of the tank. A reactor for continuous production of polyester, which is provided with an oscillating blade which is arranged so as to rotate the inner wall surface of the tank close to the tank and to send out the processing liquid attached near the wall surface to the outer periphery of the tank by rotating. 16. The reactor according to claim 10, wherein an inlet and an outlet for the liquid to be treated are provided at one end and the other end of the substantially horizontal cylindrical container main body in the longitudinal direction, respectively. An outlet is provided, and a stirring rotor that rotates close to the inside of the main body in the longitudinal direction of the inside of the main body is provided. The stirring rotor is configured by a plurality of stirring blade blocks according to the viscosity of the processing liquid. An end connecting the outer peripheral plate between the respective partition disks constituting the stirring blade block, and connecting the power transmission shaft on the end side and the stirring rotor portion in the stirring rotor having no rotating shaft at the center of the stirring rotor. A reactor for continuous production of polyester, wherein the outer diameter of the plate is smaller than the outer diameter of the stirring rotor. 17. A side wall and a lower part at one end in a longitudinal direction of a substantially vertical cylindrical container main body, which is used in an intermediate reaction stage of a process for producing a high molecular weight polyester from an aromatic dicarboxylic acid or a derivative thereof and a glycol. In a device having an inlet and an outlet for the liquid to be treated at the center, a volatile substance outlet at the top of the main body, and the outside of the main body covered with a heat medium jacket, a heat exchange section is provided at the lower portion inside the main body, and at the middle inside the main body. A stagnation portion having a spiral baffle plate for holding the liquid to be treated and moving it sequentially from below is provided, a space for gas-liquid separation is provided in the upper part of the main body, and the liquid to be treated is vertically moved in the central part in the main body. A reactor for continuous production of polyester, comprising a downcomer for flowing down a thin film. 18. A process for producing a high-molecular-weight polyester from an aromatic dicarboxylic acid or a derivative thereof and a glycol, which is used in the first reaction stage, wherein a vertical cylindrical container body is provided with an inlet and an outlet for a liquid to be treated. A multi-tube type in which a vapor tube for discharging steam is provided, the cylindrical container body is covered with a heat medium jacket, and the outside of the tube is heated by a heat medium inside the cylindrical container body, and the liquid to be treated rises inside the tube. In the natural circulation type evaporator having a built-in heat exchanger, the average velocity of the liquid to be treated flowing down by natural convection between the inner wall of the cylindrical container body and the outer wall of the shell of the multitubular heat exchanger is the multitubular type. An approach space for uniformly lowering the liquid to be treated, which is lower than the average flow rate of the liquid to be treated ascending inside the tubes of the heat exchanger and which is internally circulated in the lower part of the shell outside the multi-tube heat exchanger, is provided. That Natural circulation evaporator to the butterflies.