JP3610935B2 - Continuous polycondensation apparatus and method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for stirring a highly viscous substance, and more particularly to an apparatus and method suitable for continuous polymerization reaction of polycondensation polymers such as polyethylene terephthalate and polycarbonate.
[0002]
[Prior art]
Conventionally, as a horizontal continuous processing apparatus for polycondensation polymers such as polyethylene terephthalate, as shown in Japanese Examined Patent Publication No. 53-1228, a liquid to be processed is scooped up with a ring-shaped disk and a scraping plate, and a perforated plate or a metal mesh Some of them dropped to form a thin film, and volatiles were evaporated to react.
[0003]
[Problems to be solved by the invention]
However, the prior art described above evaporates volatiles while dropping on a perforated plate or a wire mesh in the direction of gravity, and there is room for improvement because sufficient consideration has not been given to keeping the thin film state long. Further, since the configuration of the stirring blade has the same structure from the inlet to the outlet of the processing liquid, there is a problem that the viscosity range that can be processed is limited.
[0004]
The object of the present invention is to improve the above-described conventional technology, to maintain the liquid to be processed in the main body in a thin film state for a long time with a relatively simple stirring blade structure, and to improve the viscosity of the processing liquid. It is an object of the present invention to provide a continuous polycondensation apparatus and a continuous polycondensation method which can efficiently react a polymer having a high quality and a high quality by providing an optimum stirring blade shape.
[0005]
[Means for Solving the Problems]
The above-mentioned object has an inlet nozzle and an outlet nozzle for the liquid to be treated at the lower end of the substantially horizontal cylindrical container main body in the longitudinal direction and a lower end of the other end, respectively, and an outlet nozzle for volatiles at the upper part of the main body. In a continuous polycondensation apparatus provided with a stirring rotor that rotates in the longitudinal direction inside and close to the inside of the main body, the stirring rotor does not have a rotating shaft at the center of the stirring rotor and is a rotor that is connected to a plurality of strength members It has a support member at both ends, and is composed of a low-viscosity, medium-viscosity, and high-viscosity stirring blade block corresponding to the viscosity of the treatment liquid formed between the support members. A low-viscosity stirring block comprising a bucket portion provided in a viscosity region and composed of a plurality of scraper plates, a thin disc and a first hollow disc to which a processing liquid is poured from the bucket portion, and provided in a medium-viscosity region Both sides A medium viscosity stirring block comprising a first hollow disk, a plurality of hollow thin plates having the same outer diameter disposed therein, and a plurality of scraper plates penetrating these members radially disposed on the outer periphery; A high viscosity agitation block provided in a high viscosity region on the outlet nozzle side of the liquid to be treated and a plurality of wheel type discs installed at appropriate intervals and a scraping plate installed alternately on the front and rear of the outer periphery of the wheel type disc Using the continuous polycondensation device, a prepolymer having a low degree of polymerization is continuously supplied from the inlet nozzle of the liquid to be treated, and stirring is performed while forming an optimal liquid film by each stirring block. By rotating the rotor and stirring the treatment liquid, a good surface renewal is performed to evaporate volatiles such as ethylene glycol and move it toward the outlet nozzle of the liquid to be treated to increase the degree of polymerization. With continuous polycondensation method of terephthalate and polycondensation is achieved.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an embodiment of the present invention. FIG. 1 is a front view showing a longitudinal section of the apparatus of the present invention. In the figure, 1 is a horizontally long cylindrical container body whose outer periphery is covered with a heat medium jacket (not shown), and rotation support shafts 3a and 3b are attached to both ends in the longitudinal direction. A stirring rotor 4 is attached between the rotation supporting shafts 3a and 3b, and one rotating shaft 3a is connected to a drive device (not shown). The stirring rotor 4 has a rotor support member 2 connected to strength members 5a, 5b, 5c, and 5d at both ends (in this embodiment, four are shown, but the number to be used is determined by the size of the rotor). The stirring rotor 4 including a plurality of stirring blocks is formed between the support members 2. The agitation rotor 4 has a low-viscosity agitation block composed of a bucket part constituted by scraper plates 6a and 6b on the inlet nozzle 11 side, a thin disk 7a for pouring the treatment liquid from the bucket part, and a hollow disk 8. (The detailed structure will be described with reference to FIG. 2, FIG. 6 and FIG. 7). Next, in the medium viscosity region, hollow discs 8 are arranged on both sides, a plurality of hollow thin plates 7b having the same outer diameter are disposed therein, and a plurality of scraping plates 6c penetrating these members are radially provided on the outer peripheral portion. A medium-viscosity agitation block (configured in detail with reference to FIGS. 3, 4, 8, and 9) is provided. Further, a plurality of wheel-shaped discs 9 are installed at appropriate intervals on the outlet side, and a scraper plate 10 is installed on the outer peripheral portion of the wheel-shaped disc 9 to show a high viscosity stirring block (detailed structure is shown in FIG. 5). This will be described with reference to FIG. Further, an outlet nozzle 11 for the liquid to be processed is attached to the lower portion of the other end of the main body 1. Further, an outlet nozzle 14 for volatile substances is provided in the upper part of the main body 1, and is connected to a condenser and a vacuuming device (not shown) by piping.
[0007]
In such an apparatus, the low-viscosity liquid (prepolymer) having a low polymerization degree continuously supplied from the inlet nozzle 11 is first stirred in the low-viscosity stirring block shown in FIG. The viscosity of the treatment liquid at this time is several Pas to several tens Pas. The low-viscosity stirring block forms a bucket with scraping plates 6 a and 6 b on the outer periphery of the hollow disc 8. When rotated as shown in the figure, it operates to scoop up the processing liquid into the bucket. 6 and 7 schematically show the flow state of the treatment liquid at this time. A small gap δ (FIG. 2) is formed at the bottoms of the scrapers 6a and 6b. For this reason, a part 100 of the low-viscosity processing liquid 91 staying at the bottom of the container is scooped up by the bucket along with the rotation of the stirring rotor, and the bucket tilts inward by the rotation and the processing liquid flows out to the inside (101 in FIG. 6). Leaking little by little to the outside (102 in FIG. 6), the liquid films 101 and 102 are formed both inside and outside the bucket. Further, the processing liquid 101 that has flowed inward is poured into a thin plate disk 7a installed at the tip of the inner bucket (103 in FIG. 7), and the surface of the thin plate disk 7a and the thin plate disk 7a and the thin plate disk 7a. A thin liquid film 103 is formed on both sides, and a wide evaporation surface area can be secured. These actions are repeated each time the bucket rotates, and a sufficient evaporation surface and a good surface renewal action can be obtained. At this time, a sufficiently good performance can be obtained even at a low speed of 0.5 to several rpm (10 rpm or less), and a great effect can be obtained in reducing the stirring power consumption. Further, the by-product evaporated from the treatment liquid passes through the hollow portion 20a of the hollow disc 8 and the hollow portion 20a of the thin disc 7a and is discharged from the outlet nozzle 14 for volatile matter. The processing liquid that has passed a predetermined residence time in the low viscosity stirring block increases the viscosity to about several tens of Pas and reaches the next medium viscosity stirring block. The detailed structure of the medium viscosity stirring blade block is shown in FIGS. The medium-viscosity stirring blade block is composed of a hollow disk 8, a thin hollow disk 7b, and a scraping plate 6c. The hole diameter D1 of the hollow disk 1 and the hole diameter D3 of the thin disk 7b depend on the amount of reaction by-products in the processing liquid. Accordingly, it is determined so as to obtain an optimum diameter. The optimum diameter of the hole diameter D2 of the thin disk 7b is determined according to the viscosity of the processing liquid and the amount of reaction gas. The treatment liquid 92 having reached several tens of Pas is lifted by the scraping plate 6c by rotation as shown in FIGS. 8 and 9, and the scraping plate is inclined by the rotation, so that the liquid drips and forms a liquid film 104. The liquid film 104 hangs on the connecting strength member 5a of the stirring rotor with rotation, and the liquid film is held for a long time. In addition, the processing liquid drawn up by the rotation drips down inside the hollow portion 20 a of the hollow disk 8 to form a liquid film 105. In addition, the liquid film 107 is similarly formed on the thin plate disk 7b. However, the processing liquid drips also on the small holes 20b provided in the thin plate disk 7b to form the liquid film 106. The treatment liquid further increases the degree of polymerization and increases the viscosity of the treatment liquid due to the large evaporation surface area and good surface renewal action while forming such a liquid film. When the treatment liquid viscosity reaches several hundred Pas, it is treated in the next high viscosity stirring block. The stirring block for high viscosity has a scraping plate 10a attached to the outer periphery of a wheel-type disc 9 as shown in FIG. Such a wheel-type disk 9 is connected at a predetermined interval by stirring strength members 5a, 5b, 5c, and 5d in the horizontal direction. At this time, the scraping plates before and after the wheel-type disk 9 are alternately installed as 10a and 10b, and the horizontal length of the scraping plate is such that the trajectories of the tip portions overlap each other when the disc rotates. The entire inner wall is scraped off. As shown in FIG. 10, the treatment liquid 93 reaching several hundred Pas is lifted by the scraping plate 10a by the rotation of the stirring blade. The lifted processing liquid drips 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-type disk 9 to create a complicated liquid surface shape. When the viscosity of the treatment liquid further increases and reaches several thousand Pas, the amount of liquid that is lifted increases. If the rotational speed is increased in such a state, a rotating phenomenon is caused in which the liquid is again picked up before the processing liquid drips down. Therefore, it is necessary to operate at a rotational speed of 10 rpm or less. The optimum operating range needs to be lowered as the viscosity of the treatment liquid increases, and the range of 0.5 to 6 rpm was optimum in the experiments by the inventors. As described above, the polycondensation reaction is promoted by repeating the stirring and the surface renewal action. The volatile matter generated by the reaction sequentially moves in the longitudinal direction in the main body 1 through the hollow portion of the hollow disc, and is discharged out of the system from the volatile nozzle 14. The liquid to be treated having a high degree of polymerization and a high viscosity in this manner is discharged out of the system from the outlet nozzle 12.
[0008]
In the case of polymerizing polyethylene terephthalate with such an apparatus, the intermediate polymer of the liquid to be treated is continuously supplied from the inlet nozzle 11 and the surface is renewed by stirring with the stirring rotor 4 to volatilize ethylene glycol or the like generated by the polymerization reaction The product is removed by evaporation, and the polycondensation reaction proceeds to give a highly viscous polymer. 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, in the range of a liquid temperature of 260 to 300 ° C., a pressure of 0.01 to 10 kPa, and a rotational speed of 1 to 10 rpm. Then, the polymer is discharged out of the system from the outlet nozzle 12. At this time, the polymer is stirred in the main body 1 in an almost complete self-cleaning state and is subjected to good surface renewal, so that a high-quality product polymer can be efficiently obtained without deterioration due to retention.
[0009]
Similarly, the present invention can be applied to continuous bulk polymerization of polycondensation resins such as polyamide and polycarbonate.
[0010]
【The invention's effect】
According to the present invention, it is possible to perform good surface renewal by stirring the treatment liquid with an optimum stirring block in accordance with the viscosity of the treatment liquid, and to efficiently produce a high-quality polymer.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional front view showing an embodiment of a continuous polycondensation apparatus according to the present invention.
FIG. 2 is a cross-sectional view taken along line AA in FIG.
FIG. 3 is a cross-sectional view taken along line BB in FIG.
4 is a cross-sectional view taken along the line CC in FIG. 1. FIG.
5 is a cross-sectional view taken along line DD of FIG.
FIG. 6 is a schematic diagram showing a flow of a treatment liquid in a bucket portion of a low viscosity stirring block.
FIG. 7 is a schematic diagram showing a flow of a treatment liquid in the vicinity of a thin disk of a low viscosity stirring block.
FIG. 8 is a schematic diagram showing the flow of the treatment liquid near the hollow disc of the medium viscosity stirring block.
FIG. 9 is a schematic diagram showing the flow of a thin disc-shaped treatment liquid of a medium viscosity stirring block.
FIG. 10 is a schematic diagram showing a flow of a treatment liquid in a high viscosity stirring block.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Container main body, 3a, 3b ... Shaft for rotation support, 4 ... Stirring rotor, 5a, 5b, 5c, 5d ... Strength member for stirring rotor configuration, 2 ... Rotor support member, 6a, 6b, 6c ... Scraping plate 7a, 7b ... thin discs, 8 ... hollow discs, 9 ... wheel discs,
10a, 10b ... scraping plate, 11 ... inlet nozzle, 12 ... outlet nozzle, 14 ... outlet nozzle for volatiles, 20a, 20b, 20c ... hollow part, 91, 92, 93 ... treatment liquid level, 100, 101, 102 , 103, 104, 105, 106, 107, 109, 110... Liquid film.

Claims (2)

A substantially horizontal cylindrical container main body has an inlet nozzle and an outlet nozzle for the liquid to be processed at the lower end and the lower end of the other end, respectively, and a volatiles outlet nozzle at the upper portion of the main body. In the continuous polycondensation apparatus provided with a stirring rotor that rotates close to the inside of the main body,
The stirring rotor has a rotor support member connected to a plurality of strength members without having a rotating shaft at the center of the stirring rotor at both ends, and has a low viscosity corresponding to the viscosity of the treatment liquid formed between the support members. It consists of a stirring blade block in the middle, middle viscosity, and high viscosity ranges,
Provided in a low-viscosity region on the inlet nozzle side of the liquid to be treated, and composed of a bucket portion constituted by a plurality of scraping plates, a thin plate disk on which the treatment liquid is poured from the bucket portion, and a first hollow disc. A low viscosity stirring block;
Provided in the medium viscosity region, the first hollow disk is arranged on both sides, a plurality of hollow thin plates of the same outer diameter are installed in it, and a plurality of scraping plates that penetrate these members in the outer periphery are radially provided A medium viscosity stirring block configured by installing one piece;
A high-viscosity agitation block provided in a high-viscosity region on the outlet nozzle side of the liquid to be treated, in which a plurality of wheel-type discs are installed at appropriate intervals, and scraper plates are alternately installed on the outer peripheral portion of the wheel-type disc. A continuous polycondensation apparatus characterized by comprising: A substantially horizontal cylindrical container main body has an inlet nozzle and an outlet nozzle for the liquid to be processed at the lower end and the lower end of the other end, respectively, and a volatiles outlet nozzle at the upper portion of the main body. A stirring rotor that rotates close to the inside of the main body,
The stirring rotor has a rotor supporting member connected to a plurality of strength members without having a rotating shaft at the center of the stirring rotor at both ends, and has a low viscosity according to the viscosity of the processing liquid formed between the supporting members. It consists of a stirring blade block in the middle, middle viscosity, and high viscosity ranges,
A bucket portion composed of a plurality of scraping plates provided in a low-viscosity region on the inlet nozzle side of the liquid to be treated, and a thin disc and a first hollow disc on which the treatment liquid is poured from the bucket portion. A low viscosity stirring block;
A first hollow disk is provided on both sides of the medium viscosity region, a plurality of hollow thin plates having the same outer diameter are installed therein, and a plurality of scraping plates that penetrate these members are radially provided on the outer periphery. A medium viscosity stirring block configured by installing one piece;
A high-viscosity agitation block in which a plurality of wheel-type discs are installed at appropriate intervals in the high-viscosity region on the outlet nozzle side of the liquid to be treated, and scraper plates are alternately installed on the outer periphery of the wheel-type disc. A continuous polycondensation device composed of
Using this continuous polycondensation device, a prepolymer with a low degree of polymerization is continuously supplied from the inlet nozzle of the liquid to be processed, and the processing liquid is stirred by rotating the stirring rotor while forming an optimal liquid film by each stirring block. Thus, it is possible to carry out good surface renewal, evaporate volatiles such as ethylene glycol, and polycondensate polyethylene terephthalate which is moved toward the outlet nozzle of the liquid to be treated to increase the degree of polymerization. Condensation method.

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