JPH10259242A - Continuous polycondensation apparatus and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus and method for continuous polycondensation, covering a wide range of viscosity of a liquid to be treated and consuming less power for agitation, which satisfactorily renews liquid surfaces while keeping thin films of the liquid in the apparatus body for an extended period by the aid of an agitating blade of relatively simple structure, to efficiently produce a polymer of high quality. SOLUTION: This apparatus is equipped with a horizontal, cylindrical vessel body 1 and agitating rotor 4 arranged in the longitudinal direction to rotate in the vicinity of the inner wall of the body 1, wherein two or more agitating blocks, optimized for a viscosity range of a liquid to be treated, are connected to each other in the agitating rotor 4 to form the agitating rotor 4, and shafts 3a and 3b to rotate the agitating rotor 4 are provided at both ends of the agitating rotor 4 via support members 2a and 2b, so as to dispense with a shaft or the like in the center of rotation of the agitating rotor 4. The liquid to be treated in the body 1 is made into thin films by the agitating blocks, optimized for a viscosity range of the liquid, to provide a wide evaporation surfaces, thereby securing a sufficient surface-renewal effect and efficiently producing a polymer of high quality.

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 stirring a highly viscous substance, and more particularly to a method for stirring a polyethylene terephthalate.
TECHNICAL FIELD The present invention relates to an apparatus and a method suitable for a continuous polymerization reaction of polycondensation polymers such as glass and polycarbonate.

[0002]

2. Description of the Related Art Conventionally, as a horizontal continuous processing apparatus for polycondensation polymers such as polyethylene terephthalate, Japanese Patent Publication No.
As shown in -1228, there was a method in which a liquid to be treated was scooped up with a ring-shaped disk and a scraping plate, dropped on a perforated plate or a wire mesh to form a thin film, and a volatile substance was evaporated to react.

[0003]

However, the above-mentioned prior art evaporates volatiles while dropping on a perforated plate or a wire mesh in the direction of gravity, and there is room for improvement in maintaining the state of a thin film for a long time. . Further, since the structure of the stirring blade has the same structure from the inlet to the outlet of the processing liquid, there is a problem that the range of viscosity that can be processed is limited.

An object of the present invention is to improve the above prior art,
A relatively simple structure of the stirring blade allows the liquid to be treated in the main body to be kept in a thin film state for a long time to perform good surface renewal. It is an object of the present invention to provide a continuous polycondensation apparatus and a continuous polycondensation method for efficiently reacting a high-quality polymer having a wide range.

[0005]

The above object is achieved by a stirring blade which connects a stirring rotor to a plurality of stirring blocks optimal for the viscosity of each processing solution.

[0006]

FIG. 1 shows an embodiment of the present invention. FIG. 1 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). This stirring rotor 4 has 5a, 5b, 5c, 5d at both ends.
(In this embodiment, four rotors are shown, but the number of rotors used is determined by the size of the rotor.) The rotor support members 2a and 2b are connected to each other, and a plurality of stirring members are provided between the support members 2a and 2b. The stirring rotor 4 composed of a block is formed. 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. A detailed configuration is shown in FIG. 11, which is an EE section in FIG. The stirring rotor 4 has a low-viscosity region on the inlet nozzle 11 side in a bucket portion constituted by oyster plates 6a and 6b and a thin disk 7a into which the processing liquid is poured from the bucket portion.
And a low-viscosity stirring block composed of a hollow disk 8 (detailed structure will be described with reference to FIGS. 2, 6, and 7). 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. 10 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) having a lower degree of polymerization supplied more continuously 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. 6 and 7 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. 6), and the bucket tilts inward due to the rotation, and the processing liquid flows out toward the inside (101 in FIG. 6), and also to the outside. Leak little by little (102 in FIG. 6), and apply the liquid film 1 on both the inside and outside of the bucket.
01 and 102 are formed. Further, the processing liquid 101 which has flowed inward is poured into the thin disk 7a provided at the tip of the inner bucket (103 in FIG. 7), 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. The rotation speed at this time is a low speed rotation of 0.5 to several rpm (10 rpm).
m 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. 3 and 4 show the detailed structure of the medium viscosity stirring blade block. The medium-viscosity stirrer block is composed of a hollow disk 8, a thin hollow disk 7b and an oyster plate 6c. The hole diameter D1 of the hollow disk and the hole diameter D3 of the thin disk 7b are determined by the amount of reaction by-product gas in the processing liquid. The diameter is determined so as to be optimal according to the diameter. 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. The processing liquid 92 having several tens Pas is lifted up by the cockle plate 6c by rotation as shown in FIGS. 8 and 9, and the liquid drops down because the cockle plate is inclined by the rotation 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. Further, the processing liquid dragged by the rotation is dripped into the hollow portion 20 a of the hollow disk 8 to form a liquid film 105. The liquid film 107 is similarly formed on the thin disk 7b, but the processing liquid also drips down into the small holes 20b provided on the thin disk 7b to form the liquid film 106. 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. 10, the treatment liquid 93 which has reached several hundred Pas is lifted by the oyster plate 10a by the rotation of the stirring blade. 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 liquid increases, and in our experiments, 0.5 to 6 rpm
The range of m was optimal. 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 above the outlet nozzle 12, but does not adhere to the support member 2b because the outer diameter of the support member 2b of the stirring rotor is smaller than the outer diameter of the stirring rotor 4. 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.

When polymerizing polyethylene terephthalate with such an apparatus, an 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 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 invention can be applied to continuous bulk polymerization of polycondensation resins such as polyamide and polycarbonate.

[0010]

According to the present invention, good surface renewal can be performed by stirring the processing liquid with the optimum stirring block according to the viscosity of the processing liquid, and a high quality polymer can be efficiently produced. .

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional front view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a sectional view taken along line CC of FIG. 1;

FIG. 5 is a sectional view taken along line DD of FIG. 1;

FIG. 6 is a schematic diagram of a flow of a processing liquid in a bucket portion of a low-viscosity stirring block.

FIG. 7 is a schematic diagram of a flow of a processing liquid near a thin disk of a low-viscosity stirring block.

FIG. 8 is a schematic diagram of a flow of a processing liquid near a hollow disk of a medium viscosity stirring block.

FIG. 9 is a schematic view of a flow of a processing liquid in a thin disk shape of a medium viscosity stirring block.

FIG. 10 is a schematic diagram of a flow of a processing liquid in a high-viscosity stirring block.

FIG. 11 is a sectional view taken along line EE of FIG. 1;

[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, 10a, 10b: oyster plate, 1
1 ... Inlet nozzle, 12 ... Outlet nozzle, 13a, 13b ...
Oyster member, 14 ... Volatile outlet nozzle, 20a, 2
0b, 20c: hollow portion, 91, 92, 93: treatment liquid level, 100, 101, 102, 103, 104, 10
5, 106, 107, 109, 110: liquid film.

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

Claims (9)

[Claims] 1. A substantially horizontal cylindrical container body has an inlet and an outlet for a liquid to be treated at one lower end and the lower end of the other end in the longitudinal direction of the main body, and has an outlet for volatile matter at an upper part of the main body. The stirring rotor inside the main body of the apparatus provided with a stirring rotor that rotates close to the inside of the main body in the longitudinal direction is constituted by a plurality of stirring blade blocks according to the viscosity of the processing liquid, and a rotating shaft is provided at the center of the stirring rotor. A continuous polycondensation apparatus characterized in that the outer diameter of an end plate connecting the power transmission shafts at both ends and the agitating rotor section is smaller than the outer diameter of the agitating rotor. 2. The continuous polycondensation apparatus according to claim 1, wherein
The stirring block for low viscosity is provided with hollow disks 8 at both ends,
A bucket portion for scooping up the processing liquid by the oyster plates 6a and 6b is provided on the outer peripheral portion of the disk, and a plurality of hollow thin circular plates 7a are installed near the inner peripheral end surface of the oyster plate.
The processing liquid collected in the bucket portion is poured into the hollow thin disk 7a by the rotation of the blade, and a structure is formed in which a liquid film is formed between the thin disks. A continuous polycondensation apparatus comprising a stirring block for viscosity. 3. The continuous polycondensation apparatus according to claim 2, wherein
A continuous polycondensation apparatus characterized in that a bucket portion for scooping up the processing liquid formed by the oyster plates 6a and 6b is provided with a hole or a slight gap through which the processing liquid flows out at a horizontal joint portion of the bottom oyster plate. 4. The continuous polycondensation apparatus according to claim 1, wherein
The stirring block for medium viscosity has hollow discs 8 at both ends,
A plurality of oyster plates 6c are radially provided on the outer periphery of the disk, and a plurality of hollow thin plates 7b having the same size as the outer circumference of the disk are provided between the hollow disks.
A continuous polycondensation apparatus, wherein a plurality of stirring blocks formed with a plurality of are connected. 5. The continuous polycondensation apparatus according to claim 1, wherein
The stirring block for high viscosity is characterized by arranging a plurality of wheel-shaped discs 9 with an oyster plate in the horizontal direction and alternately setting the mounting positions of the front and rear oyster plates to form a stirring block. Polycondensation equipment. 6. The continuous polycondensation apparatus according to claim 1, wherein
The outer diameter of the support member on the high viscosity side connecting the stirring rotor unit is smaller than the outer diameter of the stirring rotor, and the inner wall surface of the tank is rotated between the side surface of the support member and the inner end surface of the tank so as to rotate. A continuous polycondensation apparatus characterized by providing an oscillating blade so as to send out a processing liquid attached near a wall surface to an outer peripheral portion of a tank. 7. The apparatus according to claim 1, wherein a prepolymer having a low degree of polymerization is continuously supplied from an inlet nozzle, and the processing liquid is stirred by rotating the rotor while forming an optimum liquid film by each stirring rotor. A continuous polycondensation method of polyethylene terephthalate, which performs good surface renewal, evaporates volatiles such as ethylene glycol, and moves toward the outlet to increase the degree of polymerization. 8. The continuous polycondensation apparatus and operation method according to claim 1, wherein the apparatus is operated in a range where the viscosity of the processing solution at the inlet is several Pas or more and the viscosity of the processing solution at the outlet is several kPas or less. 9. The continuous polycondensation apparatus according to claim 1, wherein the rotation range of the stirring blade is 0.5 rpm to 10 rpm.