JPH07323462A - Biaxial reaction extruder - Google Patents

Abstract

PURPOSE:To obtain a reaction machine with the capability of preventing the leakage of material and achieving an adequate compression reaction by rotatably providing the tip end of each screw in the tip end of a sealed barrel, and also providing an inlet for supplying a reaction material at the tip end side of the barrel and an outlet of a reaction produced matter at the root side of the barrel. CONSTITUTION:An inlet 10 for supplying a reaction material is provided on the upside of the tip end side of a barrel 1, and an outlet 11 for a reaction produced matter is provided downwardly on a screw shaft piercing side, and also some deaeration ports are provided on the upper surface thereof. Within the barrel 1, two screws 2 are disposed side by side, where each root side of the screws 3 is rotatably supported via a shaft sealing part 7 in the screw piercing part 6 provided in the proximity of the axis of the frame 5. In the meanwhile, the tip end of the shaft 3 of each screw 2 is rotatably disposed within a cover 9 sealed and fixed on the tip end of the barrel by a bolt, packing or the like, and on the root side of the screw 2, a counter feeder element is arranged for preventing the leakage of material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a conventional resin extrusion
The present invention relates to a twin-screw reactive extruder in which a modified axial kneading extruder is used as a reactor for polymer polycondensation and the like.

[0002]

2. Description of the Related Art Conventionally, for example, when carrying out condensation polymerization of aromatic nylon, first, in batch, for about 8 hours,
The raw material was agitated and polymerized until it had a viscosity such that it could be extracted like a powder, and then post-polymerization was performed using an extruder for resin extrusion.

As this extruder, a twin-screw kneading extruder is known. In this twin-screw kneading extruder, the base side of the two screws arranged in parallel in the barrel, which are equipped with motors, is rotatably supported by the screw shaft penetrating portion of the barrel. An inlet for supplying the reaction material was provided in the, and the kneaded resin was extruded from a die provided at the tip of the barrel.

[0004]

As described above, in the batch method, the reaction time is very long and the efficiency is low. The present inventor considered that the conventional twin-screw kneading extruder was modified so that it could be used as a twin-screw reaction extruder instead of the conventional polymerization tank type reactor. However, when the material to be reacted is supplied from just before the screw shaft penetrating portion on the root side of the screw and the reacted product is extruded from the tip side of the screw as in the conventional case, The following inconvenience occurred.

That is, at the starting point of the reaction, it is necessary to supply various materials such as monomers and oligomers under pressure.
The material before the reaction has low viscosity. On the other hand, since the rear end of the screw shaft is connected to the drive unit, the screw shaft penetrating part is provided at the rear end of the barrel, and packing and labyrinth are provided in this part. Although a seal portion such as a mechanical seal is provided, the seal is insufficient for a low viscosity material supplied in a pressurized state, and the pressure cannot be maintained under pressure.

This means that the screw shaft is rotating,
The space is narrow, there is a gap between the screw and barrel, and it is difficult to support both ends of the screw shaft. Especially, when the screw length becomes about 2 to 3 m and the ratio of screw length to screw diameter becomes large, the shaft length increases. It is also considered that the fluctuation of the object becomes large.

[0007]

According to the present invention, in order to eliminate these drawbacks, the base side of the two screw motors arranged in parallel in the barrel, which are equipped with the motors, is rotatable by the screw shaft penetrating portion of the barrel. In the twin-screw reaction extruder supported by, the tip of each screw is rotatably installed inside the tip of the sealed barrel, the inlet for the reaction material is provided at the tip of the barrel, and the screw shaft penetrates the root side of the barrel. A reaction product discharge port was provided on the side of the unit.

[0008]

[Function] While the screw of the twin-screw reaction extruder is being rotated, the reactant is supplied from the inlet for supplying the reactant provided at the tip of the barrel, and the screw is rotated to bring the material to the front side of the barrel. The reaction product is discharged during the movement to the discharge shaft, and the reacted product is discharged from the discharge port provided on the screw shaft penetrating side of the barrel.

In this case, since there is no screw shaft penetrating portion on the tip side of the barrel for supplying the material, the barrel is sealed.
Even if a material having a relatively low viscosity and being pressurized is supplied here, the sealing does not matter. Therefore, the pressurized state can be sufficiently maintained and the reaction can be performed well. on the other hand,
At the outlet side of the barrel near the screw shaft penetration, the reaction causes the viscosity of the product to rise sufficiently, so there is no problem with the seal at the screw shaft penetration.

[0010]

1 is a longitudinal sectional view showing an embodiment of the present invention, and FIG. 2 is a partially enlarged view of FIG. 1 and 2 in FIG.
Is a cylindrical barrel, 2 is a screw element or screw assembled by arranging several kinds of different segments in the axial direction around the shaft 3 which is also the core rod of the shaft core part, 4 is a heater provided around the barrel 1, and 5 is A frame,
In the barrel 1, two screws 2 were arranged horizontally in parallel.

The base side of the screw 2 is a screw shaft penetrating portion 6 provided near the axis of the frame 5, and is rotatably supported by being sealed by a shaft sealing portion 7 having packing, labyrinth, or mechanical seal. ing. In some cases, water around the screw shaft penetrating portion 6 can be cooled. A motor (not shown) (illustrated as 13 in FIG. 3) in the box 8 is connected to the root side of the shaft 3 of the screw 2 penetrating the screw shaft penetrating portion 6.

The tips of the shafts 3 of the two screws 2 are rotatably arranged in a cover 9 which is hermetically fixed to the tips of the barrel 1 with bolts and packing. The tip of the shaft 3 is free in the cover 9, and the screw element at the tip and the outer peripheral surface of the screw 2 at other portions are rotatably supported by the cover 9 and the inner peripheral surface of the barrel 1. ing. In some cases, the tip of the shaft 3 may be rotatably supported by a bearing (not shown).

A reverse feeding element 2a, which is often used in a kneading extruder, is arranged at the root of the screw 2 so that the reaction product does not go to the shaft seal portion 7 as much as possible, and the reaction product is discharged from the discharge port 11. It was designed to be discharged smoothly. An inlet 10 for supplying a reaction material is provided on the upper side or the lateral side of the barrel 1 on the upper side, and a discharge port 11 for the reaction product is provided on the screw shaft penetrating side of the barrel 1 toward the lower side or the lateral side. A degassing port 12 was provided at several points on the upper surface of the barrel 1. The deaeration port 12 was equipped with a not-shown pushing device called a vent stuffer that discharges steam and air but returns the resin so that it does not come out.

In this embodiment, the material to be reacted is supplied from the inlet 10 on the tip side of the barrel 1 while the two screws 2 are being rotated. The materials are transferred to the front side while reacting by the mixing by the rotation of the screw 2 composed of various segments and the heating by the heater 4 outside the barrel 1. The material has an extremely low viscosity when supplied, but the viscosity increases as it reacts, and after sufficiently reacting, it becomes a reaction product and is ejected from the ejection port 11 on the front side.

Since the tip side of the barrel 1 is sealed by the cover 9, the material has a low viscosity and does not leak outside even at high temperature and high pressure. At the base side of the barrel 1, there is a screw shaft penetrating portion 6, but here the product has a sufficiently high viscosity due to the reaction, and due to the action of the reverse feeding element 2a, there is no leakage and there is no seal. Problem does not occur.

Therefore, the material can sufficiently hold the pressure under pressure, and the reaction efficiency is improved. Since the tip of the screw 2 is rotatably supported in the barrel 1 like a normal twin-screw kneader, the screw 2 is
Even with a length of ~ 3m, there is almost no run-out of the screw.

FIG. 3 is a simplified view of the apparatus of FIG. 1, and FIG. 4 is a diagram showing the relationship between the degassing port, the degassing amount, and the molecular weight of the reactant. The position on the horizontal axis in FIG. 4 is shown in correspondence with the position in FIG. While the screw 2 is being rotated, for example, 66 salt aqueous solution and solid 6T salt are supplied from the inlet 10 for supplying the reaction material, and the mixture is transferred while being stirred by the action of the screw 2 to cause condensation polymerization and reaction generation. The material is discharged from the discharge port 11. The biaxial screws are partially meshed in the same direction or meshed in different directions.

Degassing is performed by vacuum suction from the degassing port 12 as appropriate. 760 mmHg at 1 vent 12
(Open to the atmosphere), No. 2 Degassing port 12 is 360mmH
g, No. It was set to 210 mmHg at the 3 degassing port 12. In addition, the inlet 10 and the No. Between 1 deaeration port 12, for example, the temperature is 250 ° C. and the vapor pressure is 22 kg / cm.
No. ² 2 The temperature at the vent 12 is 33
It was adjusted to 0 ° C. Inlet 10 and No. 1 Degassing port 12
The area between and corresponds to the conventional batch.

FIG. 4 shows the increasing state of the ratio A of the degassing amount to the charged amount corresponding to FIG. 3 in%, and the increasing state of the molecular weight or the viscosity B. As can be seen from FIG. 4, the deaeration amount that is dehydrated and evaporated by the heating and stirring by the heater 4 and discharged as vapor is large in the first part,
No. The viscosity B does not increase so much after the first degassing port 12, but the viscosity B increases as the reaction progresses and approaches the discharge port 11. The viscosity of the reaction product at the outlet 11 is, for example, about 2.5 times the viscosity of the reaction material at the inlet 10.

In this apparatus, the heater 4 can be divided into a plurality of parts to be controlled, and the temperature of the reactant can be controlled according to the position, so that the temperature unevenness can be eliminated. Also, the shape of the screw element 2,
By appropriately changing the number and the like and appropriately selecting the screw configuration, the retention state of the reactant can also be appropriately changed.
No. (1) It is also possible to arrange a backward feeding element 2a having a relatively narrow width in a part of the screw element 2 located immediately before the degassing port 12 so as to prolong the retention time of the reactant. it can.

[0021]

According to the present invention, in each screw of a twin-screw reaction extruder, the root side of which motors of two screws arranged in parallel in the barrel are mounted is rotatably supported by the screw shaft penetrating portion of the barrel. The tip of the barrel was rotatably provided inside the sealed barrel, the inlet for supplying the reaction material was provided at the tip of the barrel, and the discharge port for the reaction product was provided at the screw shaft penetrating side at the base of the barrel. Therefore, the material does not leak from the tip side or the root side of the barrel.

That is, since the tip end side of the barrel is sealed, the material has a low viscosity and does not leak to the outside even at high pressure. Also, at the root side of the barrel, there is a screw shaft penetrating part, but here the product has a sufficiently high viscosity due to the reaction, so it does not leak.

Therefore, the material can sufficiently hold the pressure under pressure, and the reaction efficiency is improved. Also, the tip of the screw is rotatably supported inside the end of the sealed barrel, so even if the screw becomes long, there is no vibration of the screw and it rotates smoothly and smoothly without vibration.
A good reaction is performed.

Further, according to the present invention, since it can be used as an alternative to the conventional relatively large polymerization tank system, the apparatus is made compact, the installation space is not taken up much, and the equipment cost is low. Also leads to the reduction of Moreover, the reaction time is relatively short, and a relatively small amount of reaction is possible.

[Brief description of drawings]

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

FIG. 2 is an enlarged view of a part of FIG.

FIG. 3 is a simplified diagram of FIG.

FIG. 4 is a diagram showing changes in degassing amount and molecular weight or viscosity of a reactant.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Barrel 2 Screw element (screw) 2a Reverse feeding element 3 Shaft 6 Screw shaft penetrating part 7 Shaft seal part 9 Cover 10 Reactant material supply inlet 11 Reaction product discharge port 12 Degassing port 13 Motor

Claims (1)

[Claims] 1. A twin-screw reaction extruder in which the motor-sides of two screws arranged in parallel in the barrel are rotatably supported by the screw shaft penetrating portion of the barrel, and the tip of each screw is sealed. It is rotatably provided inside the tip of the barrel, and an inlet for supplying the reaction material is provided at the tip of the barrel.
A twin-screw reaction extruder having a discharge port for reaction products on the screw shaft penetrating side on the base side of the barrel.