JP4144967B2 - Horizontal reactor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a horizontal reactor used for the synthesis of polymer compounds such as polyester, polyamide and polycarbonate. More specifically, the present invention relates to a horizontal reaction apparatus used for the synthesis of a polymer compound that by-produces a volatile low-molecular substance by reaction.
[0002]
[Prior art]
Polymers such as polyester, polyamide, and polycarbonate, among them polyester represented by polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate have excellent physical and chemical properties and are widely used in various applications. . In particular, polyester is excellent in mechanical properties such as strength and elastic modulus, heat resistance, and the like, and is therefore widely used as industrial fibers such as clothing and tire cords, or as films and engineering plastics.
[0003]
Generally, a direct polymerization method or a transesterification method is used as a method for producing a polyester used for such various applications.
[0004]
Here, the former direct polymerization method is a method in which a polyester precursor is formed by directly esterifying an acid component and a diol component, and then the polyester precursor is polycondensed under reduced pressure to produce a polyester. is there. On the other hand, the latter transesterification method is a method in which a lower alkyl ester of an acid component and a diol are transesterified to form a polyester precursor, and then the polyester precursor is polycondensed under reduced pressure.
[0005]
In the case of polymerization of such a polyester, conventionally, a batch method has been used in many cases. However, in recent years, taking advantage of the scale, and in order to produce a polyester at a low cost, switching to a continuous method has been promoted. . This is because the merits such as yield reduction, quality improvement, uniformity of polymerization degree, improvement in operability, etc. are extremely large by adopting the continuous method.
[0006]
In general, most of the production methods by continuous polymerization of polyester are performed by a process in which a plurality of transesterification reaction apparatuses or esterification reaction apparatuses and a polycondensation reaction apparatus are combined. For example, the raw material is first supplied to an ester exchange reaction apparatus or an esterification reaction apparatus to produce a monomer or oligomer, and the obtained monomer or oligomer is supplied to an initial polycondensation reaction apparatus to react under reduced pressure. To produce a low polymer. Next, a system is used in which this low polymer is further supplied to a polycondensation reaction apparatus to produce an intermediate polymer and a high polymer under reduced pressure.
[0007]
In such a polycondensation reaction apparatus, many methods for obtaining a higher reaction rate have been proposed and put into practical use. For example, as one of such conventional methods, a thin film reactor is used in which a reaction is performed in a thin layer for the purpose of quickly separating and removing by-products such as glycols in a polyester polycondensation reaction. It is being used. In addition, by vigorously stirring to increase the evaporation area of the reaction product, a reaction apparatus that can easily evaporate the by-product is also used.
[0008]
As such a reaction apparatus, a wet wall type or screw type vertical reaction apparatus, or a uniaxial or biaxial horizontal reaction apparatus is generally used. Furthermore, many reactors that are agitated so that the free surface area of the reactant can be increased are commercially available. However, these reactors are required to perform intense agitation. Therefore, there is a problem that the equipment cost is high and a lot of energy is consumed. In addition, due to the reaction associated with intense stirring, the resulting reaction product has a problem that the degree of polymerization is likely to occur and the quality of the resulting polyester is deteriorated. Furthermore, there is a serious problem that the quality of the reaction product is deteriorated by the deterioration polymer due to the insufficient renewal of the polymer or the like staying in the gas phase for a long time.
[0009]
As a conventional technique for solving such a problem, Japanese Patent Publication No. 40-3964 proposes to use a horizontal reaction apparatus. In this conventional technique, the reaction solution is stirred up by stirring, and a large part of the stirred up reaction solution is dropped, so that a new liquid film of the reaction solution is constantly formed and the reaction is performed in a very short time. Is. Further, this reaction apparatus employs a structure in which the stirring shaft is eliminated from the intermediate portion inside the horizontal reactor by providing the stirring shafts respectively holding the stirring blades only at both ends of the horizontal reactor. In addition, the reactor comprises (1) the agitating blades facing each other with a small gap with respect to the inner peripheral wall surface of most horizontal reactors, and (2) partitioning the interior of the horizontal reactor into two or more chambers. The central portion has an opening, and further includes a partition plate that rotates integrally with the stirring blade. At that time, it has been proposed that the diameter of the opening provided in the partition plate increases as it approaches the liquid discharge port from the liquid injection port.
[0010]
Certainly, according to such a reaction apparatus, the inner peripheral wall surface of the horizontal reactor can be renewed while constantly being wet with new reaction liquid, so heat transfer to the reaction liquid is good, and the reaction liquid is kept for a long time. It has the advantage that it does not adhere to the inner peripheral wall surface. In addition, since a stirring shaft is not provided in the middle part of the horizontal reactor, there is a great advantage that a situation in which a mass of dumpling reaction liquid is generated around the stirring shaft does not occur. However, the reaction apparatus has a drawback that when the distance between the partition plates is increased, it is difficult to form a stable dripping film when the reaction solution falls from the stirring blade. In the reaction apparatus, most of the reaction solution overflows from the central opening provided in the partition plate and flows into the adjacent chamber partitioned by the partition plate, so that the reaction solution having a high degree of polymerization and a high viscosity can be obtained. There is a problem that it is difficult to feed liquid stably and continuously toward the discharge port.
[0011]
Moreover, as a prior art for solving the above-mentioned problem, Japanese Patent Application Laid-Open No. 8-259699 discloses a polymer having a high viscosity due to continuous or discontinuous ribbon blades attached to a plurality of flat plates provided with slits. A polymerization reaction apparatus has been proposed in which liquid is stably fed to the outlet side. Certainly, in this conventional apparatus, the liquid feeding capacity is increased by using the ribbon blade, but the structure of the apparatus is due to the configuration of “continuous or discontinuous ribbon blades attached to a plurality of flat plates provided with slits”. Is complicated, which is disadvantageous in terms of device production and cost.
[0012]
[Problems to be solved by the invention]
In view of the problems described above, the problem to be solved by the present invention is that a strong stirring is not required, and the generation of foreign substances during the reaction can be reduced, whereby the reaction speed or the reaction efficiency and the polyester produced. Is to provide an inexpensive horizontal reactor capable of significantly improving the quality of the reactor.
[0013]
[Means for Solving the Problems]
Here, as means for solving the above-mentioned problems, a horizontal reactor used for the synthesis of a polymer compound comprising polyester, polyamide or polycarbonate, and comprising the following elements (A) to (F) A reactor is provided.
(A) A cylindrical horizontal reactor having an inlet and an outlet for the reaction liquid at both ends or in the vicinity of both ends.
(B) A rotatable end disk provided to face both ends of the horizontal reactor.
(C) A shaft provided only at both ends of the horizontal reactor, which drives the end disks provided at both ends.
(D) An opening is provided in the central part to allow the reaction liquid to flow, and the liquid level of the reaction liquid is controlled by the opening to form a gas phase part and a liquid reservoir part in the horizontal reactor, Opening disk disposed between the partial disks.
(E) Stirrer blades installed near or in close proximity to the inner peripheral wall surface of the horizontal reactor between the end disk and the open disk and / or between the open disks.
(F) A flow diverting member that is provided on at least one of the stirring blades and for diverting the reaction liquid flowing down the stirring blade into a plurality of flows.
In the present invention, it is preferable that the diversion member has a liquid feeding function with respect to the reaction liquid so as to generate a velocity component in the outlet direction in the liquid reservoir of the horizontal reactor.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings. FIG. 1 is a side cross-sectional view illustrating a horizontal reactor for carrying out the present invention.
[0015]
In this figure, 1 is a horizontal reactor main body, 2 is a reaction liquid inlet, and 3 is a reaction liquid outlet, which are provided at or near both ends of the horizontal reactor 1 as shown. 4 and 5 are shafts provided at both ends of the horizontal reactor 1, and 6 is a steam outlet. The steam outlet 6 opens above the outer shell of the horizontal reactor 1, It also serves as a suction port for keeping the pressure at a reduced pressure. Further, 7 is an inner peripheral wall surface of the horizontal reactor 1, and 8 and 9 are end discs with notched ends. The end discs 8 and 9 are fixed to the shafts 4 and 5, and the end discs 8 and 9 are driven by driving the shafts 4 and 5 by a driving device (not shown). Each can be rotated. At that time, it is preferable that the end discs 8 and 9 are provided with a notch opening in order to prevent the liquid in the mirror part from staying, as disclosed in JP-A-9-52041.
[0016]
Next, 10 is a stirring blade provided with a slight gap in the longitudinal direction of the inner peripheral wall surface 7 or in close contact with it, between the end disk and the opening disk and / or the opening. It is erected between the disks. At this time, the slight interval is desirably 10 mm or less, preferably 5 mm or less. By providing such a slight gap, the stirring blade 10 can be smoothly rotated. Further, reference numerals 11 and 12 denote flow dividing members, and the flow dividing members 11 and 12 are arranged in a single row or a plurality of at least a part of the stirring blade 10 in order to control the flow width of the reaction liquid flowing down the stirring blade 10. It is provided in a row. In the embodiment of FIG. 1, the flow dividing member 11 is a member having a flat plate shape, and the flow dividing member 12 is a curved plate member. Further, reference numeral 13 denotes an opening disk. The opening disk 13 is connected and fixed at a predetermined interval in the longitudinal direction by the stirring blade 10 and has an opening at the center thereof, and is provided in the opening disk 13. As the opening approaches the outlet from the inlet of the reaction solution, the opening diameter gradually increases. The open disc 13 also functions as a partition plate that partitions the interior of the horizontal reactor 1 into a plurality of chambers.
[0017]
In the horizontal reaction apparatus of the present invention configured as described above, the stirring blade 10 is rotated (rotation direction R) and close to or close to the inner peripheral wall surface 7 while the gas phase portion in the horizontal reactor 1 is rising. It is preferable that the stirring blades 10 are inclined so that the side edge faces downward and the falling edge on the opposite side faces upward. Further, while descending the gas phase portion in the horizontal reactor 1, the stirring blade 10 is inclined so that the edge close to or in close contact with the inner peripheral wall surface 7 faces upward and the falling edge on the opposite side faces downward. It is preferable to make it. By doing in this way, while the stirring blade 10 is moving up the gas phase part in the horizontal reactor 1, the reaction solution is stirred up along the inner peripheral wall surface 7, and during the lowering, the reaction solution is stirred in a thin film state. 10 can flow down from above.
[0018]
At that time, in the horizontal reaction apparatus of the present invention, the flow dividing members 11 and 12 are provided as described above, so that the flow dividing members 11 and 12 flow when the reaction liquid flows down from the stirring blade 10 in the gas phase portion of the horizontal reactor 1. The reaction solution flowing down can be divided. Further, the liquid level of the reaction liquid is maintained constant by the opening disk 13 in the liquid reservoir of the horizontal reactor 1. For this reason, when the flow dividing member 12 enters the liquid reservoir, the flow dividing member 12 exhibits the function of feeding the reaction liquid to the outlet side while stirring the reaction liquid. When the stirring blade 10 is brought into close contact with the inner peripheral wall surface 7, a tail blade 14 as shown in Japanese Patent Laid-Open No. 9-52041 is provided in an auxiliary manner while maintaining a slight gap with the inner peripheral wall surface 7. It is preferable. This is because, by doing so, the tail blade 14 can promote the renewal of the reaction liquid adhering to the inner peripheral wall surface 7 of the horizontal reactor 1.
[0019]
In the present invention, it is possible to sufficiently form a liquid flow having a stable free surface by the diverting members 11 and 12 provided on the stirring blade 10 for the reaction liquid flowing down from the stirring blade 10, One of the main features is that the diverting members 11 and 12 cause the reaction solution to be fed and stirred. This point will be described in detail below with reference to FIG. 2 (FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1).
[0020]
In FIG. 2, the stirring blades 10 are provided with an inclination of 45 ° in the direction opposite to the rotation direction thereof, and the four stirring blades 10 are arranged at an equal pitch by being shifted by 90 ° in the circumferential direction of the horizontal reactor 1. ing. Further, the stirring blade 10 is provided with a flow dividing member 11 perpendicular to the stirring blade 10. By doing in this way, the reaction liquid picked up by the stirring blade 10 is diverted by the diverting member 11, and forms a plurality of stable liquid film flows each having an appropriate width and falls. Therefore, instead of the unstable liquid film flow spreading over the entire width of the stirring blade as in the prior art, it is possible to form a target liquid film flow having a sufficiently stable free surface. As such a diversion member 11 or 12, a flat plate having an appropriate height for diverting the reaction liquid can be preferably used. At this time, since the flat plate is for forming a stable liquid film flow, the shape may be curved or uncurved as long as the object can be achieved. Further, the flow dividing member 11 can be provided with an inclination, a lattice shape or a net shape, a perforated plate, or a simple round bar or square bar.
[0021]
Here, the conditions such as the number, shape, and size of the stirring blade 10 and the opening disk 13 and the flow dividing member 11 or 12, or the installation interval differ depending on the polymer manufacturing conditions. However, under these conditions, the flow dividing member 11 or 12 is capable of forming a stable liquid film flow with the condition that the free surface area of the reaction liquid falling from the stirring blade 10 is large and does not rotate together. Is essential. Further, since the melt viscosity of the reaction liquid changes from the inlet 2 to the outlet 3 of the horizontal reactor 1, it goes without saying that these can be changed accordingly.
[0022]
The horizontal reaction apparatus of the present invention has a heating means (not shown) for heating the reaction solution to a desired temperature. At that time, the heating means can directly heat the outer shell of the horizontal reactor 1 with an electric heat source, or the outer shell of the horizontal reactor 1 has a double jacket structure as shown in FIG. A heating medium such as Dowtherm (trade name) or a heating medium vapor may be present and heated directly. Furthermore, a method of installing a heat transfer surface of a heat exchanger in the reaction chamber can be appropriately employed. In this case, the heating may be performed for each reaction chamber partitioned by the opening disk and / or further divided into the reaction chambers so that heating can be performed independently for each divided region, or two or more The reaction chamber may be heated as a unit. The reaction pressure can of course be reduced under reduced pressure, but is not limited to reduced pressure, and the reaction may be carried out under an atmosphere of inert gas under a pressure higher than normal pressure.
[0023]
Next, an experimental example when polyethylene terephthalate is produced using the horizontal reactor of the present invention is shown. In the experimental examples, “Intrinsic viscosity” is a value determined from the viscosity measured at 35 ° C. using orthochlorophenol as a solvent, and “%” is% by weight.
[0024]
A polyethylene terephthalate intermediate polymer having an intrinsic viscosity of 0.37 containing 0.04% of antimony trioxide as a polymerization catalyst was fed from the inlet 2 of the horizontal reactor 1 in FIG. 1 at a rate of 550 kg / hr. The reaction liquid was controlled to be heated from 283 ° C. at the inlet 2 to 288 ° C. at the outlet 3 by heating from a jacket enclosing a heat medium. The reaction pressure was maintained at a vacuum of 1.9 mmHg by sucking the internal gas with an ejector (not shown). Further, the rotational speeds of the shafts 4 and 5 are controlled by a motor so as to be a constant rotation of 4 rpm, and the end disks 8 and 9 are rotated through the shafts 4 and 5, and the end disks 8 and 9 are rotated. The stirring blade 10 and the opening disc 13 connected and fixed to 9 were rotated. The supplied intermediate polymer was scraped up by the stirring blade 10, and most of the intermediate polymer was dropped from the stirring blade 10 into the liquid reservoir while forming a stable liquid film by the rectifying plates 11 and 12. Also, some of them rotated with the stirring blades and the inner surface of the outer shell was constantly renewed with new polymer. This agitation promotes the volatilization of ethylene glycol and promotes the polycondensation reaction, which mainly flows into the next chamber due to overflow from the central opening of the open disc 13 and after a residence time of about 1.3 hours. From the outlet 3, a polyethylene terephthalate high polymer having an intrinsic viscosity of 0.71 was obtained. In addition, the inner peripheral wall surface 7 of the horizontal reactor 1 is constantly renewed with a new polymer due to the scraping effect of the stirring blade 10, so that it is polyethylene terephthalate with less foreign matter, and the reaction rate is compared with the case where the rectifying plates 11 and 12 are not provided. And it was about 1.2 times faster. Further, there was no problem in feeding the high polyethylene terephthalate polymer, and stable continuous operation was possible over a long period of time.
[0025]
【The invention's effect】
According to the horizontal reaction apparatus of the present invention described above, since intense stirring is not essential, the generation of foreign matters during the reaction can be reduced, whereby the reaction rate or reaction efficiency can be improved and manufactured. An inexpensive and simple apparatus capable of significantly improving the quality of the polyester is provided. Moreover, in the gas phase part of the horizontal reactor, the liquid flow width of the reaction liquid falling from the stirring blade can be controlled to a preferable value, so that it can be formed as a liquid film having a stable free surface area. Thereby, the effect of significantly increasing the reaction rate can be obtained. In the liquid reservoir of the horizontal reactor, the reaction liquid can be fed and stirred by the liquid feeding function of the flow dividing member. Thus, by using the horizontal reactor of the present invention capable of improving quality and reaction efficiency, the size of the reactor can be made compact, and the synthesis of a polymer compound with less generation of foreign matters can be achieved. It is extremely useful for producing fibers, films, and other molding materials.
[Brief description of the drawings]
FIG. 1 is a side cross-sectional view schematically illustrating a horizontal reaction apparatus of the present invention.
FIG. 2 is a cross-sectional view taken along the line AA in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Outer shell of horizontal reactor 2 Reaction liquid inlet 3 Reaction liquid outlet 6 Steam outlet 7 Inner peripheral wall surface 8 and 9 of a horizontal reactor End notch disk 10 Stirring blade 11 Dividing member (plane plate)
12 Dividing member (curved plate)
13 Opening disc 14 Tail R Rotation direction

Claims (2)

A horizontal reactor used for the synthesis of a polymer compound comprising polyester, polyamide or polycarbonate, and comprising the following elements (A) to (F).
(A) A cylindrical horizontal reactor having an inlet and an outlet for the reaction liquid at both ends or in the vicinity of both ends.
(B) A rotatable end disk provided to face both ends of the horizontal reactor.
(C) A shaft provided only at both ends of the horizontal reactor, which drives the end disks provided at both ends.
(D) An opening is provided in the central part to allow the reaction liquid to flow, and the liquid level of the reaction liquid is controlled by the opening to form a gas phase part and a liquid reservoir part in the horizontal reactor, Opening disk arranged between the partial disks.
(E) Stirrer blades installed close to or in close contact with the inner peripheral wall surface of the horizontal reactor between the end disk and the open disk and / or between the open disks.
(F) A flow dividing member that is provided on at least one of the stirring blades and splits the reaction liquid flowing down the stirring blade into a plurality of flows.   The horizontal reaction apparatus according to claim 1, wherein the diversion member has a liquid feeding function with respect to the reaction liquid so as to generate a velocity component in the outlet direction in the liquid reservoir of the horizontal reactor.

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