JPH02160837A - Continuous reaction process - Google Patents

Abstract

PURPOSE:To make it possible to perform continuously intermediate polymerization and final polymerization in the same reaction apparatus by partitioning a reaction tank with partitions each having a special structure to form a plurality of chambers, controlling the operating pressures in the respective chambers according to the reaction states of the solutions treated and agitating the solutions in the respective chambers with agitating elements of different structures. CONSTITUTION:A solution to be treated is fed to a reaction tank 5 (from 16) and agitated in a plane crossing the direction of flow in such a manner that it can be exposed to a vapor phase atmosphere in the tank. A tank body 6 is partitioned in the lengthwise direction into a plurality of chambers (e.g. 5a and 5b) with a partition 9 constructed so that it may completely partition the vapor phase in the reaction tank 5 and that it may have a passage 9a for the solution below the surface of the solution. The pressures in the respective chambers (e.g. 5a and 5b) are decreased (through a vacuum nozzles 18 and 19), the operating pressures in the respective chambers are controlled according to the states of reaction of the solutions to be treated in the respective agitated chambers, and the agitation in the respective chambers is performed with agitating elements (e.g. 10a, 10b, 11a and 11b) of different surface areas.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for removing volatile substances such as alcohol and water during the progress of single polycondensation, for example, when monomers are polycondensed to produce a high molecular weight polymer. This relates to a continuous reaction method for viscous substances.

The operation is as below. The efficiency of evaporation increases in proportion to the degree of pressure reduction, but when the atmospheric pressure is rapidly reduced, a portion of the viscous substance is discharged out of the system together with the volatile substance removed by evaporation. In addition, as evaporation promotion increases liquid viscosity and changes the physical properties of the viscous substance, conventionally, multiple reactors each having stirring blades with different stirring properties suited to the physical properties of the viscous substance were connected in series. , volatile substances were removed by sequentially lowering the pressure in each reactor. Here, to explain a conventional polyester continuous polymerization reaction apparatus using an example, when polyester low polymer is polycondensed at high temperature and reduced pressure, the reaction apparatus is designed according to the need for gradual reduction of the degree of vacuum and the physical properties of the viscous material. Because of the necessity of selecting a reaction mixture, 3-hinoki reaction Ml is generally used as shown in Fig. 1θ. That is, in the early stage of polymerization, a vertical reactor 2 is used, and in the middle stage of polymerization, as the viscosity of the viscous substance in the reactor increases and the required evaporation area increases, a horizontal uniaxial disk blade reactor 3 is used. is used. however,
The processing viscosity range of the viscous substance in this single-axis disk blade reactor [3] is at most several hundred poise, and since the viscosity of the liquid is not very high, the viscosity caused by the lateral liquid level difference in the device is −
Generally, multiple partition plates are installed to prevent this from occurring.

However, because the partition plates tend to create dead space near their attachment parts, it is desirable to use stirring blades to provide a partitioning effect as much as possible, and to reduce the number of partition plates.

Next, in the final polymerization stage, the viscosity of the liquid increases rapidly to about several thousand poise, so a horizontal biaxial reaction with good stirring*! !
4 is used. At this final polymerization stage, dead spaces tend to occur due to the high viscosity of the liquid, and countermeasures are required. For this reason, as shown in Japanese Patent Publication No. 50-21514, an agitation blade has been proposed which can uniformly agitate the entire inside of the tank and has a partitioning effect by reducing the number of partition plates that tend to create dead spaces.

[Problem to be solved by the invention]

The above-mentioned conventional technology does not take into account continuous reaction within one reactor, and the conventional method has a large number of reactor components, resulting in (1) complication of the treatment process;
(2) Increased number of operation and maintenance points and complexity of work;
There were disadvantages such as (3) an increase in device manufacturing cost and (4) an increase in device installation space.

An object of the present invention is to provide a continuous reaction method that allows medium-term polymerization and final polymerization to be carried out in one reaction apparatus.

[Means to solve the problem]

In order to achieve the above objective, a partition plate is installed inside a horizontal twin-shaft reactor for conventional final polymerization, which completely partitions off the gas phase in an airtight manner and has a processing liquid passage below the liquid level. By forming multiple chambers and adjusting the operating pressure for each chamber, medium-term polymerization is carried out in the front chamber, and final polymerization is carried out in the rear chamber, thereby achieving medium-term polymerization in one reactor. treatment and final polymerization treatment.

[For production]

The liquid to be treated that is supplied into the reaction tank is stirred by a stirring blade installed on the rotating shaft and subjected to the surface renewal action to evaporate volatile components and accelerate the reaction, and the liquid is sent to reach the partition plate. . The liquid to be treated that has reached the partition plate passes through the treatment liquid passage (
The gas phase inside the reaction tank is completely airtightly partitioned into multiple chambers by partition plates, and an exhaust nozzle installed in each chamber allows each chamber to be The operating pressure in the chamber can be adjusted independently.The reaction is promoted and the liquid to be treated, whose viscosity gradually increases, is taken out from the treatment liquid outlet nozzle.

Therefore, medium-term polymerization and final polymerization, which conventionally required two or more tanks, can be carried out in one reactor.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 5. 5 is a cylindrical reactor main body installed substantially horizontally, 9 is a cylindrical main body 6 that completely partitions off the gas phase in an airtight manner, and is provided with a processing liquid passageway of 9 m below the liquid level. It is a partition plate. The partition plate 9 partitions the interior of the cylindrical main body 6 in the longitudinal direction to form a front chamber 5a and a rear chamber 5b.

7 is a heating shaft provided on the outer periphery of the main body 6, 9a is a processing liquid passage provided at the bottom of the partition plate 9, and 8a and 8b are rotating shafts provided in parallel inside the main body 6 through the partition plate 9. be. A plate-shaped supporting plate having a large surface area is fixed to the rotating shafts 8a and 8b in the front chamber 5a symmetrically in a direction perpendicular to the shaft,
A stirring blade 1 (1m, 10b) consisting of a scraping plate 13 fixed perpendicularly to the tip thereof is attached.On the other hand, a stirring blade 1 (1m, 10b) is fixed symmetrically to the rotating shaft 8m, 8b in the rear chamber 5b in a direction perpendicular to the axis. Stirring blades 11a and flb are attached, each consisting of an annular support plate 14 with a small surface area and a scraping plate 15 fixed perpendicularly to the tip thereof.Here, the stirring blades 10a and 10b and lfa and llb are opposed mutually 90
A plurality of stirring blades 10a, 10b and 11a are attached to the rotating shafts 8m and 8b with a phase angle of 100 degrees.

The tip of 11b is held so as to pass close to the rotating shafts 8m and 8b. 16 is a processing liquid inlet nozzle provided on one end side of the main body 6 of the front chamber 5a, 17 is a processing liquid outlet nozzle provided on the other end side of the main body 6 of the rear chamber 5b, 18 and 1
Reference numeral 9 denotes exhaust nozzles provided at the upper portions of the front chamber 5m and rear chamber 5b of the main body 6, respectively.

Processing liquid (liquid viscosity approximately 10 poise) that was initially polymerized in the vertical reactor 2 and supplied to the reactor 5 from the inlet nozzle 16
are rotating shafts 8a that rotate in opposite directions from the inside to the outside of the main body 6 as shown by arrows in the front chamber 5;
By the rotation of 8b, a plate-shaped stirring blade 10a with a large surface area is formed.
, 10b, the volatile components are evaporated and the reaction is promoted, the viscosity gradually increases and the liquid moves sequentially from left to right in FIG. 3 until it reaches the partition plate 9. Then, it passes through the processing liquid passage 9a and enters the rear chamber 5.
Sent to side b.

Here, the processing liquid is not filled in the reaction apparatus, and the upper part of the apparatus is a gas phase section. The gas phase section of the reactor 5 according to the present invention is completely (airtightly) partitioned by a partition section 9, and each chamber is separated by exhaust nozzles 1111 and 19 provided in the front chamber 5a and the rear chamber 5b, respectively. The operating pressures at 5a and 5b can be adjusted independently. Normally, the operating pressure in the front chamber 5a is about 4 to 8 Torr, and in the rear chamber 5b, about 1 to 2 Torr.

The processing liquid (liquid viscosity of about 300 poise) supplied into the rear chamber 5b is subjected to surface renewal action by annular stirring blades 11a and flb with a small surface area, while volatile components are evaporated, the reaction is accelerated, and the reaction is gradually accelerated. The viscosity increases and bubbles are ejected from the processing liquid outlet nozzle 17.

In addition, the volatile components evaporated in each chamber 5 m long and Sb are discharged through the exhaust nozzle 18. It is discharged from 19.

Here, the stirring blades 10a and 10b in the front chamber 5a are formed by a plate-shaped support plate with a large surface area fixed symmetrically in the direction perpendicular to the axis, and a scraping plate B fixed to the tip thereof. When the low-viscosity processing liquid in the lower part of the main body 6 is effectively stirred and passes through the upper space of the processing liquid, the liquid adheres to the surface with a larger surface area than the support plate, forming a thin film and increasing the evaporation area of the liquid. Big! (In addition, a plate-shaped support plate with a large surface area provides a partitioning effect for the liquid to be treated.

This facilitates the removal of volatile components from the low viscosity liquid and directs the liquid to be treated in the longitudinal direction of the main body 6 to the piston 7.
It can be set to 0-. In addition, stirring blades 10a, 10b
The scraping plate 13 is the inner wall of the main body 6, the rotation shafts 8a, 8b
another stirring blade 10a fixed adjacent to the outer surface of the
Since it is fixed with a small gap to the scraping plate 13 of 10b, there is a part where the stirring effect of the processing liquid is extremely small.
In other words, no dead base occurs.

In the front chamber 5a, the processing liquid is scraped up from the lower part of the main body 6 by the scraping plate 13, passes through the space above the processing liquid and then falls, filling the gap between the support plate 12 and the inner wall of the main body 6 with the scraping plate 13.
The stirring blade 10a moves to the liquid outlet nozzle 17 side and adjoins the stirring blade 10a as described above.

10 b. Thereafter, the reaction is promoted by moving inside the main body 6 while repeating this action.

In this case, since the viscosity of the processing liquid in the front chamber 5a is low within the range of 10 to 300 poise, the stirring blades 10m and 10b
By making the support plate ratio plate-like, it is possible to sufficiently stir and mix the treatment liquid, and it is also possible to prevent carbon dioxide from passing or back-mixing.

On the other hand, although the processing liquid in the rear chamber 5b has a high viscosity, the stirring blade with the annular support plate 14 with a small surface area! 1a,f
Since lb is used, it can be attached to the blade surface.

In the above embodiment, one partition plate 9 is provided in the main body 6 of the reactor 5.
Although the explanation has been given on a case in which a plurality of partition plates 9 are provided in the main body 6 to form two chambers, the front chamber 5m and the rear chamber 5b, if necessary, a plurality of partition plates 9 can be provided in the main body 6 to form a plurality of rooms, and each room in the main body 6 can be It is also possible to perform polymerization under optimal stirring conditions for increasing the viscosity of the liquid to be treated by decreasing the pressure of the stirring blades in the downward pressure chamber sequentially from the inlet to the outlet. It can be easily implemented.

According to a preferred embodiment of the invention, FIGS.
As shown in the figure, a stirring blade 1 having an annular support plate 14 with a relatively large surface area is mounted on a rotating shaft 8''*8b in a front chamber 5 m'.
Attach 0i and 1Ob and rotate the ear shaft g in the rear chamber 5b'.
There is one in which rectangular lattice-shaped stirring blades 30a and 30b having a smaller surface area are attached between a/ and g and b/. According to this embodiment, since the stirring blades 30a and 30b having a sufficiently small surface area and no rotating shaft are used in the rear chamber 5b', the stirring blade surface and the Since adhesion to the rotating shaft can be reduced, it is possible to process ultra-high viscosity liquids.

According to a further preferred embodiment of the present invention, as shown in FIG. Stirring blades 10m and 10b with plate-shaped support twists are arranged, and the center @2
Stirring blades 11a and llb having an annular support plate 14 having the next largest surface area are arranged in the chamber 5b', and the third chamber 5 on the liquid outlet side
30 m of rectangular lattice stirring blades with the smallest surface area in C'
, (9)b is attached. According to the invention,
The viscosity increases due to reaction from the liquid inlet to the liquid outlet at the optimal vacuum pressure depending on the treatment liquid! The pressure inside the 1-N3 chamber can be reduced, and the surface area of the stirring blade can be gradually reduced in accordance with the increasing viscosity of the treating liquid, so that an optimal polymerization operation can be performed in response to the increasing viscosity of the treating liquid. As a result, optimal surface renewal and stirring can be obtained according to each viscosity, which is effective in shortening reaction time and improving the quality of each treatment liquid.

〔Effect of the invention〕

As described above, according to the present invention, medium-term polymerization and final polymerization treatment, which conventionally required two or more tanks, can be performed in one reactor, thereby reducing the number of reactors in the treatment system. (1) Simplification of processing steps, (2) Reduction of operation and maintenance points and simplification of work, (3) Reduction of equipment manufacturing costs, (4)
Effects such as a reduction in equipment installation space can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing an example of a polymerization reaction apparatus using a horizontal reaction apparatus according to the present invention, and Fig. 2 is a system diagram showing an embodiment of a polymerization reaction apparatus using a horizontal reaction apparatus according to the present invention. A plan view showing a part of an embodiment of Iw in cross section, FIG. 3 is also a longitudinal sectional view, fi4 is a sectional view taken along the line A--A in FIG. N3, and FIG. 6 is a vertical sectional view of a polymerization reaction apparatus according to another embodiment of the present invention, FIG. 7 is a sectional view taken along the line C-C in FIG. 6, and FIG. 8 is a sectional view taken along the line D-D in FIG. 6. 9 is a longitudinal sectional view of a polymerization reaction apparatus according to another embodiment of the present invention, and FIG. 10 is a system diagram of a conventional polymerization reaction apparatus. 2...Vertical reactor, 3...Curved single-axis disk blade reactor, 4...Horizontal twin-shaft reactor, 5...Vertical reactor, 5a... ... Anterior chamber, 5b... Posterior chamber, 6.
Curved/cylindrical body, 7... Heating jacket, 8
a, 8b...Curved rotation axis, 9...Partition plate, 9m.
...Processing liquid passage, 10a. 10 b, na, 11 b... curved stirring blade, ν
... Curved support plate, 13.15 ... Scraping plate, 14 ...... Annular support plate, 16 ......
Processing liquid inlet nozzle, 17... Curved processing liquid outlet nozzle l
Flash 2 Flash Figure A Flash 17 Figure O 8

Claims (1)

[Claims] 1. Supply the liquid to be treated into a reaction tank, stir the supplied liquid to be treated in a plane that crosses the flow direction in the reaction tank so that it can be exposed to the atmosphere of the gas phase in the tank, and stir the supplied liquid to be exposed to the atmosphere of the gas phase in the tank. In addition to completely partitioning the gas phase within the tank, the main body is divided into multiple chambers in the longitudinal direction using a partition plate with a processing liquid passage below the liquid level, and the pressure in each chamber is reduced, allowing the liquid to be processed in each stirring chamber to be separated. A continuous reaction method characterized by adjusting the operating pressure for each stirring chamber according to the reaction situation and stirring and mixing using stirring blades with different surface areas.