JP2000017078A - Continuous processing of thermoplastic material and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a continuous processing method and an apparatus for a thermoplastic material to obtain a high-quality thermoplastic material by enabling fluidized mass flow when a thermoplastic material is continuously supplied and processed with a gas. SOLUTION: An apparatus has a thermoplastic material inlet 3 and a gas exit 8 on the top of a processing tower 1, a thermoplastic material exit 4 at the bottom of the processing tower, gas supplying inlets 6a and 7a on the side wall of the lower part of the processing tower 1 which have open ends inside of the side wall and a separating boards 9 facing the gas supplying inlets 6a and 7a which boards have downward open-ends. In this case, a thermoplastic material and a gas for processing are continuously supplied from the thermoplastic material inlet 3 and gas supplying inlets 6a and 7a, respectively. The thermoplastic material is continuously processed by subjecting the thermoplastic material and the gas to a counter-flow contact.

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 continuously treating a thermoplastic material such as polyamide, and more particularly, to a high-quality thermoplastic material which is uniformly treated by continuously flowing the thermoplastic material in a mass flow. The present invention relates to a method and an apparatus for continuous processing of a thermoplastic material to obtain a material.

[0002]

2. Description of the Related Art Conventionally, as a method for performing continuous processing such as heating, cooling, drying or solid phase polymerization of a thermoplastic substance such as polyamide, a continuous processing apparatus as shown in FIG. 4 has been used, for example. This apparatus forms a conical part 2 at the lower part of a cylindrical processing tower main body 1, a thermoplastic substance supply port 3 at an upper part,
The lower part is provided with a thermoplastic substance outlet 4 and a rotary valve 5. Further, gas supply pipes 6, 7 are provided at the lower part of the processing tower main body 1.
Is inserted so as to extend to the center of the interior, the gas supply ports 6a and 7b are opened at the insertion ends, and the processing tower body 1
The gas discharge port 8 is provided at the upper part. And when performing continuous processing of a thermoplastic substance, the pellet-shaped thermoplastic substance is supplied from the thermoplastic substance supply port 3,
Further, the processing gas is continuously supplied from the gas supply ports 6a and 7b so that the thermoplastic material and the processing gas are brought into contact with each other.

However, in this continuous processing apparatus, the gas supply pipes 6, 7 are inserted so as to extend to the center of the inside of the processing tower body 1, so that the gas supply pipes 6, 7 are formed into pellet-like heat. It tends to disturb the flow of plastics. Therefore, there is a problem that the treatment of the thermoplastic substance with the treatment gas becomes non-uniform.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a high quality thermoplastic material by allowing the mass flow of the thermoplastic material in continuous processing with a gas while continuously supplying the thermoplastic material. It is an object of the present invention to provide a method and an apparatus for continuously treating a thermoplastic material.

[0005]

According to the present invention, there is provided a method for continuously treating a thermoplastic material, comprising the steps of: providing a thermoplastic substance supply port and a gas discharge port at an upper portion of a processing tower main body; A thermoplastic substance discharge port is provided at a lower lower end, a gas supply port is provided on a lower side wall so as to be opened on the inner surface of the side wall, and a partition plate which is opened downward facing the gas supply port is provided. The thermoplastic substance and the processing gas are brought into countercurrent contact with each other while continuously supplying the thermoplastic substance from the substance supply port and the processing gas from the gas supply port.

Further, in the continuous thermoplastic material processing apparatus according to the present invention, a thermoplastic material supply port and a gas discharge port are provided at an upper portion of a processing tower main body, and a thermoplastic material discharge port is provided at a lower lower end of the processing tower main body. A gas supply port is provided in the lower side wall so as to open to the inner surface of the side wall, and a partition plate that opens downward facing the gas supply port is provided. The thermoplastic material and the processing gas are brought into countercurrent contact with each other while continuously supplying the processing gas from the gas supply port.

As described above, the gas supply port is attached to the main body of the processing tower such that the gas supply port is opened to the inner surface of the side wall of the main body of the processing tower and the gas supply pipe does not extend to the inside of the main body of the processing tower. The thermoplastic can be homogenized without disturbing the flow in the gas supply pipe. Further, since the gas supply port is provided with a partition plate that opens downward, even if the gas supply port is open on the inner wall surface of the processing tower main body, the gas supply port is clogged with a thermoplastic substance. In addition, a smoother supply of the processing gas enables a better uniform processing of the thermoplastic material.

[0008]

FIG. 1 schematically shows an example of a continuous processing apparatus for a thermoplastic material used in the present invention. In this continuous processing apparatus, an upper main body portion of a processing tower main body 1 is formed in a cylindrical shape, and a lower portion is formed in an inverted conical conical portion 2. In the upper part of the processing tower main body 1, a thermoplastic substance supply port 3 for charging a thermoplastic substance in the form of pellets is provided. A thermoplastic material outlet 4 is provided at the lower end of the conical portion 2, and a rotary valve 5 is further provided downstream thereof.

The thermoplastic substance supply port 3 and the thermoplastic substance discharge port 4 only open to the inner wall surface of the processing tower main body 1, and do not have a portion extending to the inside of the processing tower main body 1. Further, the volume of the conical portion 2 occupies at least 10% of the entire volume of the processing tower main body 1 and its half apex angle A is 2 to 2.
It has a sharp angle of 20 degrees. Here, the half apex angle is shown in FIG.
Angle A shown in FIG.

[0010] Gas supply pipes 6, 7 are connected to the side wall of the inverted conical conical portion 2 in two upper and lower stages. The gas supply pipes 6 and 7 have gas supply ports 6a and 7a at their ends opened directly to the inner wall surface of the conical portion 2 so as not to enter the inside of the processing tower body 1. Further, a partition plate 9 which opens downward is opposed to the outlet side of the gas supply ports 6a and 7a which open directly to the inner wall surface via a small gap. The partition plate 9 guides the processing gas injected from the gas supply ports 6a and 7a downward, and then supplies the processing gas into the processing tower main body 1 (see FIG. 2).

In the illustrated embodiment, of the two upper and lower gas supply pipes 6 and 7, the upper gas supply pipe 6 is a supply pipe for heating gas, and the lower gas supply pipe 7 is a cooling processing pipe. It is a supply pipe for the working gas. These two gas supply pipes 6 and 7 are provided so as to be opposed to each other, and may be vertically connected to the wall surface in the cross section of the conical part 2 as shown in FIG. Or FIG. 3 (B)
As shown in the figure, the conical portion 2 may be tangentially connected to the wall surface in the cross section.

When the gas supply pipes 6 and 7 are connected at right angles to the wall surface of the cross section as shown in FIG. 3A, the processing gas supplied from the gas supply pipes 6 and 7 is left and right after colliding with the partition plate 9. The water is divided into two sides, guided further downward while being further divided, and supplied into the processing tower body 1. Further, when the tangential direction of the cross-section wall surface is connected as shown in FIG.
The processing gas supplied from 7 is guided downward while being swirled around the partition plate 9 in the same direction, and is supplied into the processing tower body 1. In either case, the gas supply pipes 6 and 7 do not extend into the inside of the processing tower main body 1 and the gas supply pipes 6 at the ends are provided.
The openings a and 7a are opened directly on the inner wall surface.

On the other hand, a gas outlet 8 is provided in the upper part of the processing tower body 1. The gas outlet 8 is also used for the treatment tower body 1.
It does not have a part extending inside, and discharges the processing gas supplied into the processing tower body 1 from the supply ports 6a, 7a of the gas supply pipes 6, 7 as described above. The processing gas supplied from the supply ports 6a and 7a into the processing tower body 1 rises while being brought into countercurrent contact with the pellet-shaped thermoplastic substance supplied into the processing tower body 1 from the thermoplastic substance supply port 3 and flowing down. Then, the gas is discharged from the gas discharge port 8.

According to the continuous processing apparatus of the present invention described above,
When the pellet-shaped thermoplastic material is continuously supplied from the upper thermoplastic material supply port 3, the thermoplastic material flows down the inside of the processing tower main body 1 while the gas supply pipe 6 connected to the lower conical portion 2. , 7 are treated in countercurrent contact with the processing gas continuously supplied from the supply ports 6a, 7a.

In the processing of the thermoplastic substance by the processing gas, the gas supply pipes 6 and 7 are not extended into the processing tower main body 1, and the gas supply ports 6a and 7a are opened to the inner wall surface. Therefore, when the pellet-shaped thermoplastic substance flows down as described above, the flow can be made into a mass flow state without being disturbed, so that a uniform treatment can be performed. In the continuous processing apparatus, the gas supply port 6
Since the partition plates 9 are provided opposite to each other, the gas supply ports 6a, 7a are not blocked by the pellet-like thermoplastic substance. The processing gas can be smoothly supplied even if the processing gas is directly opened on the inner wall surface.

In the embodiment shown in the drawings, since the volume of the conical portion 2 occupies at least 10% of the volume of the processing tower body 1, the mass flow of the thermoplastic material is further smoothed, and the processing by the processing gas is performed. Can be made uniform, and a thermoplastic substance having excellent uniformity can be obtained.
The partition plate 9 facing the gas supply ports 6a, 7a is shown in FIG.
As shown in (A) and (B), when formed in an annular shape along the inner wall surface of the processing tower body 1 (cone-shaped portion 2), the processing gas can be distributed evenly around the entire processing tower body 1, Since it is distributed uniformly throughout the inside of the processing tower body 1, more uniform processing of the thermoplastic material is enabled.

The conical portion 2 may have a conical shape or a pyramid shape, but as described above, the volume occupying the processing tower main body 1 is preferably at least 10% of the processing tower main body volume. More preferably, it is set to 20% or more.
If necessary, the volume of the conical portion 2 may be 1 volume of the processing tower body.
It may be 00%. That is, 100% means that the entire processing tower main body 1 is gradually reduced in diameter from the upper part to the lower part and formed in a conical shape.

Further, the conical portion 2 has a half apex angle A
The angle is preferably set to 20 degrees, more preferably 2 degrees to 15 degrees. By making the half vertex angle A such an acute angle, the mass flow of the thermoplastic substance in the treatment tower main body 1 can be further facilitated, and partial stagnation can be eliminated. The size of the processing tower body 1 is determined by its thermoplastic material supply port 3
From the maximum width D in the side view of the processing tower body 1 to the length L from the
It is preferred to be in the range of 15. More preferably,
The ratio L / D is preferably set to 3 to 8.

In the present invention, the treatment of a thermoplastic substance includes:
The method may be any of heating, cooling, drying or solid-phase polymerization with a processing gas, and is not particularly limited, but is particularly suitable when applied to drying or solid-phase polymerization. For example, by connecting a forced supply means such as an air blower to a gas supply pipe, supplying a processing gas controlled to a predetermined temperature into the processing tower main body, and setting the processing tower main body to a predetermined temperature environment. The thermoplastic can be treated to heat or cool. Also, by providing a plurality of gas supply pipes for supplying gases having different temperatures as in the embodiment of FIG. 1, a time elapses between the supply of the thermoplastic substance to the treatment tower main body and the discharge thereof. The processing can be performed so as to change the temperature environment.

The flow rate of the processing gas is controlled so as not to disturb the flow of the thermoplastic substance by controlling the supply amount or increasing the diameter of the processing tower body (cone portion) near the gas supply port. Can be. The residence time from the supply of the thermoplastic substance to the discharge inside the processing tower body to the discharge is set by installing a rotary valve at the thermoplastic substance discharge port as in the illustrated embodiment, and controlling the number of rotations of the rotary valve. It can be controlled by adjusting the emissions.

The thermoplastic substance applicable to the continuous processing apparatus of the present invention is not particularly limited, and examples thereof include polyamide, polybutylene terephthalate, polyacetal, polyethylene,
Although a thermoplastic material such as polypropylene can be used, it is particularly effective when applied to polyamide. The form of the thermoplastic material is pellet (chip)
It is in the form of granules, granules, powders, etc., and among these, it is most preferable to make them into pellets.

Hereinafter, the case where the polyamide 6 is dried or solid-phase weighed using the continuous processing apparatus of the present invention will be specifically described. Polyamide 6 is obtained by polycondensation of ε-caprolactam using water as a catalyst by a usual method and cutting into pellets. The polyamide 6 contains low-molecular-weight substances such as monomers and oligomers in an amount of several percent to several tens percent by polymerization equilibrium.

The extracted polyamide 6 pellets are
When the processing gas is continuously supplied from the thermoplastic substance supply port 3 into the processing tower main body 1 and the processing gas is supplied from the gas supply ports 6a and 7a, the polyamide 6 pellets are heated by countercurrent contact with the processing gas, It flows while performing drying or solid phase polymerization, and is discharged from the thermoplastic material discharge port 4 via the conical portion 2. Here, an inert gas such as dehumidified nitrogen is preferably used as the processing gas.

Processing gases having different temperatures are supplied from the gas supply ports 6a and 7a, and a high-temperature region and a low-temperature region are formed in the processing tower main body 1, and drying or solid-state polymerization and cooling are performed. . The polyamide 6 pellets thus treated become a mass flow without using an insert such as a rectifying spacer or the like, so that they are uniformly treated and discharged from the thermoplastic substance discharge port 4.

The temperature inside the processing tower body 1 is preferably 101 to 125 ° C. in a high temperature region in the case of a drying process.
More preferably, the temperature is set to 115 to 120 ° C. In the case of solid-phase polymerization, the temperature is preferably set to 126 to 186 ° C. On the other hand, in the low-temperature region, both the drying treatment and the solid-phase polymerization treatment are preferably performed at 0 to 100 ° C, and more preferably at 30 to 70 ° C.

The processing time in the high temperature region of the processing tower body 1 is preferably 5 to 50 hours, more preferably 10 to 30 hours. On the other hand, the processing time in the low temperature range is preferably 0.5 to 5 hours, and more preferably 0.5 to 3 hours. The processing time can be controlled by controlling the number of rotations of a rotary valve 5 provided on the outlet side of the thermoplastic substance discharge port 4 or by controlling the processing amount.

According to the continuous processing apparatus of the present invention, since the thermoplastic substance is discharged while flowing in a mass flow, a funnel flow and abnormal stagnation do not occur.
Therefore, the thermoplastic substance can be continuously and uniformly treated, and a very high-quality thermoplastic substance without coloring or deterioration can be produced.

[0028]

EXAMPLES The present invention will be described below with reference to examples and comparative examples. Physical properties and the like used in the examples and comparative examples were measured by the following measuring methods. [Color Tone (YI)] The YI (yellow index) value of the pellet was measured by an SM color computer (Suga Test Machine).

[Sulfuric acid relative viscosity (ηr)] JIS-K68
According to the provisions of 10 above, 98% sulfuric acid was used as a solvent and dissolved in the solvent at a concentration of 10 g / L.
% Relative sulfuric acid was measured. [Water (w)] After adding 20 ml of methanol to 10 g of the pellets and extracting by boiling, the water in methanol was measured by a Karl Fischer moisture meter. The differences between the maximum value and the minimum value of the measured values YI, ηr, and w are indicated by ΔYI, Δηr, and Δw, respectively.

Example 1 A continuous processing apparatus having the configuration of FIG. 1 in which the half vertex angle A of the conical portion 2 is 13 degrees, the volume is 32% of the volume of the main body of the processing tower, and L / D = 5 is used. The polyamide 6 pellets subjected to the extraction treatment after the polycondensation were introduced into the continuous treatment apparatus at 1050 kg / hr.
And continuously supply nitrogen as a processing gas so that the temperature in the high-temperature region is 115 ° C. and the temperature in the low-temperature region is 50 ° C., and the residence time in the high-temperature region is 20 hours. The drying process was performed by adjusting the number of rotations.

The obtained polyamide 6 pellets have a color tone of YI = -12.0, a sulfuric acid relative viscosity of ηr = 2.70, a water content of w = 0.01%, and are uniformly treated so that there is almost no variation. It was of high quality without coloring or deterioration. The results are shown in Table 1.

Example 2 Using the same continuous processing apparatus as in Example 1, polyamide 6 pellets extracted after polycondensation were continuously supplied to the continuous processing apparatus at 1050 kg / hr, and nitrogen was used as a processing gas. The solid-state polymerization was performed by continuously supplying so that the temperature in the high-temperature region was 150 ° C. and the temperature in the low-temperature region was 50 ° C., and adjusting the rotation speed of the rotary valve so that the residence time in the high-temperature region was 20 hours. .

The obtained polyamide 6 pellets have a color tone of YI = -11.5, a sulfuric acid relative viscosity of ηr = 3.40, a water content of w = 0.01%, and are uniformly treated so that there is almost no variation. It was of high quality without coloring or deterioration. The results are shown in Table 1.

COMPARATIVE EXAMPLE 1 A continuous processing apparatus having a structure shown in FIG. 4 in which the half apex angle A of the conical portion 2 is 30 degrees, the volume is 7% of the processing tower body volume, and L / D = 4.4. The same polyamide 6 pellets as used in Example 1 were continuously supplied at the same supply rate, and the same processing gas was continuously supplied to set the high temperature region and the low temperature region at the same temperature, and the residence time of the high temperature region was the same. And dried.

The obtained polyamide 6 pellets had a color tone of YI = -10.7, a sulfuric acid relative viscosity of ηr = 2.71 and a water content of w = 0.03%, and were inferior in average value and also varied. It was large and inferior in quality to the polyamide 6 pellets of Example 1.

Comparative Example 2 Using the same continuous processing apparatus as in Comparative Example 1, the same polyamide 6 pellets as in Example 2 were continuously supplied at the same supply rate, and the same processing gas was continuously supplied to obtain the same temperature. Solid-state polymerization was performed by setting a high-temperature region and a low-temperature region, and setting the same residence time in the high-temperature region.

The obtained polyamide 6 pellets had a color tone of YI = -9.5, a relative viscosity of sulfuric acid of ηr = 3.40, a water content of w = 0.02%, and had an inferior average value and variation. It was large and inferior in quality to the polyamide 6 pellets of Example 2.

Example 3 The same polyamide 6 pellets as in Example 1 were continuously supplied at the same supply rate using a continuous processing apparatus in which the gas supply port was replaced with the structure of FIG. 1 in the structure of FIG. The same processing gas was continuously supplied to set a high temperature region and a low temperature region at the same temperature, and the residence time in the high temperature region was set to be the same to carry out solid phase polymerization treatment.

The obtained polyamide 6 pellets had a color tone of YI = 11.1, a sulfuric acid relative viscosity of ηr = 2.70, a water content of w = 0.02%, and were uniformly treated so that there was almost no variation. It was of high quality without coloring or deterioration. The results are shown in Table 1.

[0040]

[Table 1]

[0041]

As described above, according to the present invention,
Attachment of the gas supply port to the processing tower main body was made to open to the inner surface of the side wall of the processing tower main body, and the gas supply pipe was not extended to the inside of the processing tower main body. The thermoplastic can be uniformly processed without being disturbed. Further, since the gas supply port is provided with a partition plate that opens downward, even if the gas supply port is open on the inner wall surface of the processing tower main body, the gas supply port is clogged with a thermoplastic substance. Without
The smooth supply of the processing gas enables better uniform processing of the thermoplastic material.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view of a continuous processing apparatus for a thermoplastic material used in the present invention.

FIG. 2 is an enlarged vertical sectional view showing a main part of the apparatus of FIG.

FIGS. 3A and 3B respectively show X- in FIG. 2;
It is sectional drawing which shows the mutually different aspect of X sectional view.

FIG. 4 is a schematic longitudinal sectional view of a conventional continuous processing apparatus for a thermoplastic material.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Processing tower main body 2 Conical part 3 Thermoplastic substance supply port 4 Thermoplastic substance discharge port 5 Rotary valve 6,7 Gas supply pipe 6a, 7a Gas supply port 8 Gas discharge port 9 Partition plate A Half-vertical angle

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) C08G 69/46 C08G 69/46 4J100 85/00 85/00 F term (reference) 4F070 AA13 AA15 AA42 AA48 AA54 AB09 AE29 BA02 BA03 BA06 BA10 BB03 BB05 4J001 DA01 GA15 GC10 JA01 JC01 4J011 AA05 DA05 DB15 4J029 AA03 AB05 AC01 BA05 CB06A KE12 KF07 KH03 KH06 LA16 LB05 LB07 4J031 CA06 CA49 CC09 CF01 CG02 CG04 ACG30 ACG30 CG27 CG27 CG27 ACG30 CG27

Claims (12)

[Claims] 1. A processing material supply port and a gas discharge port are provided at an upper portion of a processing tower main body, a thermoplastic material discharge port is provided at a lower lower end of the processing tower main body, and a gas supply port is provided at a lower side wall. Provided so as to open to the inner surface, and provided a partition plate that opens downward facing the gas supply port, a thermoplastic substance is continuously supplied from the thermoplastic substance supply port, and a processing gas is continuously supplied from the gas supply port. A method for continuous processing of a thermoplastic material in which a thermoplastic material and a processing gas are brought into countercurrent contact with each other while heating. 2. The method for continuously treating a thermoplastic material according to claim 1, wherein the partition plate is formed in an annular shape along an inner surface of a side wall of the processing tower main body. 3. The method for continuously treating a thermoplastic material according to claim 1, wherein a cone portion occupying at least 10% of the capacity of the processing tower body is formed at a lower portion of the processing tower body. 4. The method for continuously treating a thermoplastic material according to claim 3, wherein a half vertex angle of the conical portion is 2 to 20 degrees. 5. The method according to claim 1, wherein the treatment is heating, cooling, drying, or solid-state polymerization. 6. The method for continuously treating a thermoplastic material according to claim 1, wherein the thermoplastic material is one selected from the group consisting of polyamide, polybutylene terephthalate, polyacetal, polyethylene and polypropylene. . 7. The continuous processing method for a thermoplastic material according to claim 6, wherein the processing gas is nitrogen. 8. A processing material supply port and a gas discharge port are provided at an upper portion of the processing tower main body, a thermoplastic material discharge port is provided at a lower lower end of the processing tower main body, and a gas supply port is provided at a lower side wall. It is provided so as to open to the inner surface, and has a configuration provided with a partition plate that opens downward facing the gas supply port, the thermoplastic material from the thermoplastic material supply port,
A continuous processing apparatus for a thermoplastic substance, wherein a thermoplastic substance and a processing gas are brought into countercurrent contact with each other while continuously supplying a processing gas from the gas supply port. 9. The continuous thermoplastic material processing apparatus according to claim 8, wherein the partition plate is formed in an annular shape along an inner surface of a side wall of the processing tower main body. 10. The continuous thermoplastic material processing apparatus according to claim 8, wherein a conical portion occupying at least 10% of the capacity of the processing tower main body is formed at a lower portion of the processing tower main body. 11. The apparatus for continuously treating a thermoplastic material according to claim 10, wherein a half apex angle of the conical portion is 2 to 20 degrees. 12. The continuous processing apparatus for a thermoplastic substance according to claim 8, wherein the processing is heating, cooling, drying, or solid-state polymerization.