JPH09291154A - Polymerizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polymerizer highly effective in surface renewal and polymer stirring. SOLUTION: The polymerizer comprises: a cylindrical vessel 1 which has a feedstock inlet 2, a polymer outlet 3, and a volatile gas outlet 4 and is placed substantially horizontally; and a rotating member for liquid mixing which is disposed so as to be slightly spaced from the inner circumferential wall of the vessel l and has a lattice structure comprising blades 10 and doughnut-shaped disks 13. The width of the blade 10 decreases gradationally from the inlet 2 toward the outlet 3. The distance between two adjacent disks 13 and the inner diameter of the disks 13 increase gradationally from the inlet 2 toward the outlet 3.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention is directed to a PET by advancing a polycondensation reaction while removing low-molecular substances by-produced by the reaction.
(Polyethylene terephthalate), PBT (Polybutylene terephthalate), PC (Polycarbonate), PA
The present invention relates to a polymerization reaction device for producing a polycondensation product having a high degree of polymerization such as (polyamide), and for removing monomers and devolatilization.

[0002]

2. Description of the Related Art Generally, in a polycondensation reaction, in order to remove a volatile substance produced as a by-product and proceed a polymerization reaction, the surface area of the reactant (polymer) is increased and the surface of the reactant is rapidly renewed. However, it is necessary to promote the diffusion (mass transfer to the gas phase) of low molecular weight substances that are by-produced.

For example, PET (polyethylene terephthalate) is obtained by polycondensing bis-β-hydroxyethyl terephthalate at 270 to 290 ° C. under a pressure of about 1 Torr while removing by-produced ethylene glycol.

In the conventional continuous polymerization apparatus, there is a uniaxial or biaxial horizontal cylindrical reactor, and by rotating a disc, a grid, a wire net, etc., respectively, the surface of the polymer is renewed and diffusion of by-products is promoted. Promote and carry out polycondensation reaction.

[0005]

However, when the viscosity of the polymer is increased, the polymer lifted by a disc, a lattice, a metal net, etc. becomes difficult to flow down while being adhered to them in a semi-solid state. The ability to renew the surface is significantly reduced, and it becomes impossible to efficiently obtain a sufficient polymer.

Particularly in the structure in which the lifting member is provided on the center side of the reaction vessel, a massive polymer is formed in this portion to cause a co-rotation phenomenon, and it may occur even if stirring and mixing are not performed at all.

An object of the present invention is to solve these problems and to provide a polymerization reaction apparatus having a large surface renewal action and an excellent stirring action of the polymer.

[0008]

In order to achieve this object, in a polymerization reactor according to the present invention, a cylindrical container which is provided with a raw material inlet, a polymerized substance outlet and a volatile substance outlet is placed substantially horizontally. And a plurality of vanes and donut-shaped discs arranged in a lattice form so as to be rotatable with the axial center positions of both ends of the cylindrical container as fulcrums with a slight gap from the inner peripheral wall of the cylindrical container. The rotating body for stirring and mixing the liquid is provided.

The width of the vane is gradually reduced from the raw material inlet toward the polymer outlet, and the donut-shaped discs are attached at intervals and inner diameters from the raw material inlet to the polymer outlet. The configuration will be gradually increased toward.

In the polymerization reactor of the present invention thus constructed, the blade is inclined so that the axial center side precedes with respect to the rotational direction, and the rear end side of the blade is bent to the axial center side. It is preferable that the blades between the lattices are provided with slits for updating the liquid surface.

According to the polymerization reactor of the present invention, the polymer lifted by the rotation of the lattice-shaped rotary body constantly renews the polymer surface adhered to the inner peripheral wall while applying the polymer onto the inner peripheral wall of the container. Since the polymer flows down as a film from the bent portion provided on the upper surface of the vane and preferably on the rear side of the vane, the surface area of the reactant is large, and a new surface is always formed on the polymer.

In particular, the film-like polymer that has flowed down from the upper surface of the vane does not have any deposits such as members during the flow, so that it will not flow down to the lower part of the container or the liquid surface and the flow will not deteriorate.

Further, in the region where the viscosity of the reactant on the raw material inlet side is low, the polymer surface is frequently renewed due to the array of dense lattices of rotors that spread to the vicinity of the center with a narrow interval, and byproducts are generated. Diffusion is promoted.

On the other hand, in the region where the viscosity of the reactant is high near the outlet from the center of the cylindrical container, the polymer container is formed by the lattice set of the rotors arranged roughly at the circumferential position away from the center of the cylindrical container. Since only the surface near the wall surface is renewed, the co-rotation phenomenon between the polymer with high viscosity and the lattice group is eliminated, and the polymer with high viscosity has a good retention time distribution (piston flow property). It will be discharged from the outlet.

Further, in the case where the blade plate is inclined so that the axial center side precedes with respect to the rotation direction and the slit is formed in the blade plate, the flow of the adhered polymer is further improved so that the adhered residue is eliminated and the surface of the polymer is eliminated. It is possible to assist the renewal and obtain a polymer having a sharp molecular weight distribution.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION

(Structure) One embodiment of the polymerization reaction device according to the present invention will be specifically described with reference to the drawings. In FIG. 1, reference numeral 1 is a cylindrical container placed substantially horizontally, and this container 1 has a raw material inlet 2 near one end, a polymer outlet 3 near the other end, and a volatile substance outlet 4. ing.

The arrow-wheel-shaped arm rotating bodies 5 and 6 provided at both ends in the container 1 are fixed to rotating shafts 7 and 8 inserted from the outside of the container 1 into the shaft center of the container 1, respectively. The rotating shafts 7 and 8 are supported by bearings 12 and are rotated at an appropriate rotation speed by a driving device (not shown).

A flat blade 1 having a slit 9 provided between the arm wheel-shaped rotating bodies 5 and 6 and one end of which is slightly bent.
The front end, which is preceded by 0 in the direction of rotation, is approximately 45 ° toward the axis.
A plurality of blades 10 are fixed at a position where they are inclined downward and the end on the rear end side with respect to the rotation direction maintains a slight gap with the container 1.
The plate width is gradually reduced from the inlet 2 side of the container 1 toward the reactant outlet 3 side.

That is, in the example of FIG. 1, the area 1 on the inlet 2 side
4a, the central region 14b, and the region 14c on the outlet side are provided by reducing the width of the blade 10 in three stages. Although the slits 9 provided on the blade 10 are two rows in this example, the number and size of the slits 9 are appropriately adjusted and provided according to the viscosity of the reaction liquid.

The vane 10 has a donut-shaped disc 13 whose outer diameter matches the outer end of the vane 10 for the purpose of suppressing mixing of the polymer accumulated in the container 1 in the longitudinal direction of the container 1. Are mounted at intervals from each other. The mounting interval and inner diameter of the donut-shaped disc 13 are increased stepwise from the inlet 2 side of the container 1 to the reactant outlet 3 side. There is.

That is, in the example of FIG. 1, the area 1 on the inlet 2 side
4a, the inner diameter of the donut-shaped disk 13 is about 1/2 of the outer diameter
In addition, the mounting interval is expanded in two stages of 15a and 15b, the inner diameter is expanded in the central region 14b, and the mounting interval is expanded in two stages of 15c and 15d.
The inner diameter is further expanded by c and the mounting interval is further expanded in two steps of 15e and 15f.

In this way, the lattice set consisting of the vanes 10 and the donut-shaped discs 13 fixed between the arm rotating bodies 5 and 6 has the inlet 2 side close to the center of the container 1 and the outlet 3 close. The sides are arranged in a coarse arrangement.

(Operation / Effect) In the polymerization reaction apparatus having the above-mentioned structure, the intermediate polymer supplied from the raw material inlet 2 is distributed inside the container 1 along the inner wall surface of the container 1 by the blade 10 with the slit 9. Can be lifted.

The raw material lifted by the vanes 10 is formed into a film from the bent portions provided on the surfaces of the slits 9 and the vanes 10 and on the rear side of the vanes 10 when the vanes 10 are located in the vapor phase portion. Since there is no member that interferes with the polymer that has been made to flow down and becomes highly viscous during the flow down, the action of efficiently exposing it to the gas phase, that is, the surface renewal action is large, and the stirring action of the polymer is excellent.

Further, at this time, the region 14 on the raw material inlet 2 side
a, the viscosity of the intermediate polymer supplied from the inlet 2 is low, and here, the vanes 10 with slits 9 are closely arranged.
The surface of the intermediate polymer is closely renewed by the lattice combination of the donut-shaped disc 13 and the donut-shaped disk 13 to promote the separation and polymerization of the volatile gas. The renewal action becomes slightly gentle on the circumference side.

On the other hand, at the portion where the viscosity of the polymer in the region 14c on the polymer outlet 3 side is high, the rough surface is provided only along the inner wall surface of the container 1 due to the lattice set roughly arranged near the circumference. The renewal action is performed, the co-rotation phenomenon of the polymer in the central part of the container 1 is eliminated, the flow of the polymer to the outlet 3 becomes smooth, and the good retention time distribution (piston flow property)
Can be obtained.

Therefore, in the polymerization of the polycondensation type polymer, the volatile gas can be removed efficiently, and the polymerization rate is greatly improved. The polymerization reactor according to the present invention is not limited to these embodiments, and its shape and structure may be modified within the scope of the present invention shown in the claims.

[0028]

In summary, in the polymerization reaction apparatus of the present invention, the width of the blades of the lattice-shaped rotating body for liquid stirring and mixing is gradually reduced from the raw material inlet to the polymerized material outlet. By arranging the donut-shaped discs so that the mounting interval and the inner diameter thereof are increased stepwise from the raw material inlet to the polymer outlet, the surface renewal of the polymer is favorably promoted and high viscosity is achieved. The effect of obtaining a good retention time distribution (piston flow property) of the resulting polymer is obtained.

Further, the blade plate is mounted so as to be inclined so that the axial center side precedes with respect to the rotation direction of the lattice-shaped rotary body, the rear end side of the blade plate is bent in the axial direction with respect to the rotation direction, and
The structure in which the blades are provided with slits has the effects of further improving the flowability of the polymer and the surface renewal action, and removing the volatile gas by polymerization and greatly improving the polymerization rate.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a cylindrical horizontal polymerization reaction device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along arrows II-II in FIG.

FIG. 3 is a transverse sectional view taken along the line III-III in FIG.

FIG. 4 is an enlarged cross-sectional view of the IV section in FIG.

5 is a cross-sectional view taken along the line V-V in FIG.

6 is an enlarged cross-sectional view of a VI portion of FIG.

FIG. 7 is a cross-sectional view taken along the line VII-VII of FIG.

FIG. 8 is an enlarged cross-sectional view of a VIII portion in FIG.

9 is a transverse sectional view taken along the line IX-IX in FIG.

[Explanation of Codes] 1 Cylindrical container 2 Raw material inlet 3 Polymerized substance outlet 4 Volatile substance outlet 5,6 Arrow-shaped arm rotating body 7,8 Rotating shaft 9 Slit 10 Blade 12 Bearing 13 Donut-shaped disk 14a Area on the inlet side 14b Central area 14c Area on the outlet side 15a to 15f Increasing mounting interval of donut-shaped discs

Claims (2)

[Claims] 1. A cylindrical container provided with a raw material inlet, a polymerized substance outlet, and a volatile substance outlet and placed substantially horizontally, and the cylindrical container whose axial center positions at both ends of the cylindrical container are axial fulcrums. In addition to having a rotor for liquid stirring and mixing that is rotatably provided with a slight gap from the inner peripheral wall of the blade and is configured in a lattice set with a plurality of vanes and donut-shaped discs, the width of the vanes is used as a raw material. From the inlet of the polymer to the outlet of the polymer, and the mounting interval and the inner diameter of the donut-shaped disc were gradually increased from the raw material inlet to the polymer outlet. A polymerization reaction device characterized by the above. 2. The blade plate is inclined such that the axial center side precedes with respect to the rotation direction, and the rear end side of the blade plate is bent toward the axial center side, and a liquid surface is formed on the blade plate between the lattice sets. The polymerization reaction device according to claim 1, wherein a renewal slit is formed.