JP3392684B2 - Continuous polycondensation reaction method and apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to forming a high molecular polymer by a polycondensation reaction or the like, such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polyamide, polyethylene naphthalate, polybutylene naphthalate and liquid crystal polymer. The present invention relates to a continuous polycondensation reaction method and apparatus suitable for producing a polycondensation polymer. The present invention also relates to a continuous processing method and apparatus suitable for use in a volatile substance removing operation or a dehydrating operation from a highly viscous substance.

[0002]

2. Description of the Related Art A conventional technique is disclosed in Japanese Patent Laid-Open No. 63-10460.
As described in Japanese Unexamined Patent Publication No. 2 (1994), two cylindrical rotating bodies are installed in an apparatus body covered with a heat medium jacket, a carrying member such as a metal plate is stretched over a belt, and they are electrically heated. As a result, the liquid to be treated, which has been supplied in the form of a thin film on the surface of the conveying member, is heated to remove volatile substances from the surface. Another technique is to remove the volatile substances in the polymer by mechanically applying the polymer in a thin film onto the inner wall surface of the device with a stirrer installed inside the device like a thin film evaporator. Met.

In the case of producing a polycondensation polymer, a high polymer cannot be obtained unless the volatile substances generated in the reaction process are removed from the liquid to be treated. In addition, since the liquid to be treated is usually a highly viscous solution, the diffusion rate of volatile substances in the liquid to be treated is much slower than the evaporation rate on the liquid surface, and the concentration of volatile substances in the liquid to be treated is very low. In order to reduce the above, it is necessary to make the inside of the reactor a high vacuum or to make the thickness of the liquid to be treated very thin to promote the evaporation of the volatile substance.

However, in the former method of making a high vacuum, the design conditions of the reactor are made strict and a vacuum pump for achieving a high vacuum is required, so that the equipment cost becomes large. Further, in the latter method of reducing the thickness of the liquid to be treated, as described in JP-A-63-104602, replacement of the surface of the liquid to be treated in contact with the vapor phase part (surface renewal)
If not performed, the rate of progress of the polycondensation reaction will be extremely slow unless the thickness of the liquid to be treated is extremely thin. Therefore, a long residence time is required to obtain a high polymer. Therefore, in order to increase the amount of treatment per unit time, it is necessary to increase the size of the reactor, which increases the equipment cost. In addition, the apparatus and method such as the thin film evaporator mechanically renews the surface of the liquid to be treated. Problems such as deterioration of polymer quality due to inclusion in the product and generation of a large amount of off-spec during product type change cannot be avoided.

[0005]

DISCLOSURE OF THE INVENTION According to the present invention, by promoting evaporation of volatile substances in a liquid to be treated in a non-contact state, the flow rate of the liquid to be treated is made small (extremely thin film) for a short time. It is an object of the present invention to provide a continuous polycondensation reaction method capable of obtaining a high polymerized product in the above-mentioned manner and capable of reducing the off-spec which occurs at the time of switching the product type, and an apparatus therefor.

[0006]

In order to solve the above-mentioned problems, the present invention is to move a conveying member made of a metal plate or the like stretched between a plurality of cylindrical rotors installed in an apparatus main body, The liquid to be treated is supplied to the surface of one side of the transport member in a film form, and when they move in the main body of the device, the inert gas heated to a predetermined temperature is jetted from the multiple fine pore nozzles to the surface of the liquid to be treated. Then, the continuous polycondensation reaction method and the apparatus for renewing the surface of the liquid to be treated to allow the polycondensation reaction to proceed.

According to the continuous polycondensation reaction method and apparatus of the present invention, the surface of the liquid to be treated can be renewed in a non-contact manner by injecting an inert gas onto the surface of the liquid to be treated at a high speed. The liquid lump that was present in the liquid also comes into contact with the gas phase to accelerate the evaporation of volatile substances and reduce the concentration of volatile substances in the liquid to be treated. It is possible to reduce the off-spec that occurs in the first place as much as possible.

[0008]

The polycondensation reaction which is the object of the present invention includes, for example, polycondensation polymers such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polyamide, polyethylene naphthalate, polybutylene naphthalate and liquid crystal polymers. The reaction used for production is mentioned. In the present invention, a prepolymer of these polycondensation polymers or a prepolymerized one is used. The viscosity of the polymer to be used varies depending on the kind of the polycondensation reaction of interest and the degree of polymerization of the objective polymer, but is, for example, from 10 Pa · s to 1000 Pa.
・ S.

According to the present invention, the liquid to be treated is formed on one surface of the transfer member while moving the transfer member made of a metal plate or the like stretched between a plurality of cylindrical rotors installed in the apparatus main body at a constant speed. Is supplied in the form of a film, and when they move in the apparatus main body, an inert gas heated to a predetermined temperature is jetted at high speed from a plurality of pore nozzles onto the surface of the liquid to be treated, The surface is renewed to allow the polycondensation reaction to proceed.

Examples of the material of the conveying member used in the present invention include metals (for example, stainless steel and aluminum), rubber, and Teflon. As for the shape,
Examples include a plate shape, a wire mesh shape, and a wire shape. In the present invention, the transport member is moved at a constant speed or the like, but the residence time in the device varies depending on the target resin or the like.

Although a plurality of cylindrical rotors are used in the apparatus body of the present invention, the installation locations of these are, for example, arranged in two or more rows in the vertical direction. For example, it is installed in the upper part and the lower part in the device body. The cylindrical rotor has a rotatable cylindrical shape, and examples of the material thereof include metal (for example, stainless steel and aluminum), rubber, and resin. In some cases, the inside of the cylinder is hollow and the heating medium (heating gas, heating liquid) is circulated inside. In the present invention, the cylindrical rotor installed in the main body of the apparatus and having the surfaces of the film-shaped treatment liquid facing each other has a structure capable of maintaining the non-contact state with the liquid treatment liquid. When the cylindrical rotors are provided in the upper part and the lower part in the apparatus main body, the lower cylindrical rotor comes into contact with the liquid to be treated on the transport member. In this case, if the lower cylindrical rotor has a structure that can hold the film-shaped liquid to be treated in a non-contact state, the liquid to be treated adhered to the cylindrical rotor may stay in the apparatus body for a long time and then be mixed into the product. There is an advantage that problems such as deterioration of polymer quality and generation of a large amount of off-spec when switching product types can be avoided. As a structure capable of holding a non-contact state with the film-shaped liquid to be treated, a wheel shaft is provided at both ends of a rotary shaft connected to a driving device, a wheel shaft-like one having a concave portion provided on an outer peripheral portion of a cylindrical rotor, One example is a cylindrical rotor in which the central portion is deleted and separated into two rotors, but it is preferably a wheel shaft-shaped one in which a concave portion is provided in the outer peripheral portion of the cylindrical rotor.

The liquid to be treated supply device for supplying the liquid to be treated in a film form to one surface of the conveying member should be capable of supplying a constant amount of the liquid to be treated within a range of 0.5 mm to 5 mm. A slit device and a rod-shaped extrusion device may be used. The slit device referred to here means a device in which the shape of the outlet of the liquid to be treated has an opening having a width of 0.5 to 5 mm.

In the continuous polycondensation reaction method according to the present invention, the thickness of the liquid to be treated supplied onto the conveying member is 0.5 mm.
To 5 mm, the average cross-sectional flow velocity of the inert gas jetted from the fine pore nozzle to renew the surface of the liquid to be treated is 50 m / s to 400 m / s, and the tip of the fine nozzle and the surface of the liquid to be treated. It is preferable that the gap is set to 5 mm to 100 mm, and the installation interval of the fine pore nozzles arranged in the direction perpendicular to the traveling direction of the liquid to be treated is set to 1 mm to 20 mm. By these, it becomes possible to create an effective surface renewal state according to the viscosity of the liquid to be treated which increases with the progress of polymerization.

Further, in the continuous polycondensation reaction method according to the present invention, the inside of the apparatus main body is made into an inert gas atmosphere such as nitrogen under normal pressure or slightly pressurized condition, and an inert gas containing a volatile substance generated in the reaction process. Is cooled by sending it to a condenser installed outside the device to recover the volatile substances contained in it, then reheating it to a prescribed temperature and spraying it onto the surface of the liquid to be treated from the multiple fine hole nozzles installed inside the device body. Then, it is preferable to circulate in the main body of the apparatus.

The inert gas used in the present invention means nitrogen and Group 0 gas in the periodic table. Preferred is nitrogen.
By filling the interior of the apparatus with the inert gas, the inside of the apparatus main body is brought into a normal pressure or slightly pressurized state. Slightly pressurized state means several mmH ₂
It is a slightly pressurized state of about O.

The volatile substance generated in the reaction process varies depending on the type of polycondensation reaction to be targeted, and examples thereof include water, methanol, ethylene glycol and acetaldehyde.

The pore nozzle used in the present invention is not particularly limited, but the cross-sectional shape of the tip has a diameter or a long axis of 0.5.
A circular shape or an elliptical shape having a width of ˜3 mm, or a sectional shape of the tip having a slit shape having a width of 0.5 mm to 3 mm is preferable.
The slit shape means a shape having an aspect ratio of 1 or more. The reason why these shapes are used is that there is an advantage that the flow state is controlled according to the degree of polymerization of the liquid to be treated adhered to the member and the surface renewal efficiency is increased.

The inert gas containing volatile substances generated in the reaction process is sent to a condenser installed outside the apparatus to cool the volatile substances contained therein, and then reheated to a predetermined temperature to be stored in the apparatus main body. It is preferable to spray the liquid to be treated from a plurality of installed fine pore nozzles so as to circulate in the apparatus main body. Here, the predetermined temperature is basically the reaction temperature of the target polycondensation reaction, and varies over a wide range depending on the target polycondensation reaction. For example, in the production of polyethylene terephthalate, it is in the range of 270 to 320 ° C.

Further, in the continuous polycondensation reaction method according to the present invention, in addition to the above-mentioned structure, a scraping device for scraping the liquid to be treated on the conveying member is provided outside the main body of the device. As a result, the surface of the transport member is always kept clean.

Further, in the continuous polycondensation reaction method according to the present invention, a heater for preheating the above-mentioned carrying member is provided immediately before the entrance of the carrying member of the apparatus main body, and on the above carrying member immediately after the exit of the carrying member of the apparatus main body. It is preferable to provide a cooler for cooling the liquid to be treated. As a result, the liquid to be treated adhering to the carrying member coming out of the apparatus body is rapidly cooled and solidified to facilitate the removal from the carrying member, and the temperature of the carrying member entering the apparatus body does not hinder the reaction. Can be kept at a predetermined temperature not.

An example of the continuous polycondensation reaction apparatus according to the present invention is shown in FIG. 1, and the present invention will be described based on this, but the present invention is not limited thereto. A plurality of cylindrical rotors (2a, 2b) installed in the upper and lower parts of the apparatus body 1 and a plurality of cylindrical rotors (2c) installed outside the apparatus body
While the transfer member 3 stretched in between is moved at a constant speed by the transfer member delivery cylindrical rotor 7 installed outside the apparatus main body, the liquid to be processed is supplied to one side of the transfer member 3 by the supply slit device 4 for the liquid to be processed. The film is supplied on the surface. When they move in the apparatus main body 1, an inert gas heated to a predetermined temperature is jetted at high speed from the plurality of pore nozzles 15 onto the surface of the liquid to be treated to renew the surface of the liquid to be treated and polycondensate. Allow the reaction to proceed. As shown in FIG. 2, which is an enlarged view of the cylindrical rotor 2b installed in the lower part of the apparatus main body 1, the cylindrical rotor 2b and the liquid to be treated on the transfer member 3 always maintain a non-contact state. As described above, the wheel shaft has a recessed portion on its outer peripheral portion. FIG. 3 shows an enlarged view of the fine nozzle 15 and the fine nozzle pipe 8 for injecting an inert gas onto the surface of the liquid to be treated.

The inside of the apparatus main body 1 is at atmospheric pressure or several mmH _2.
Under an inert gas atmosphere in a slightly pressurized state of about O,
A gas seal device 9 is provided at the entrance and exit of the conveying member of the apparatus body to maintain the state inside the apparatus body. The inert gas containing volatile substances generated in the reaction process is sent to the condenser 11 installed outside the apparatus and cooled to recover the volatile substances.
After that, the inert gas is reheated to a predetermined temperature by the heating device 12 through the compressor 14 and the pipe 10, and is sprayed from the plurality of pore nozzles 15 onto the surface of the liquid to be treated. The scraping device 13 is installed outside the device main body 1 and includes the transport member 3
Scrap the above treated liquid. The conveying member heating device 5 is installed immediately before the entrance of the conveying member 3 of the apparatus body 1, and
Preheat. The transport member cooling device 6 is installed immediately after the exit of the transport member 3 of the apparatus body 1 and cools the liquid to be treated on the transport member 3.

[0023]

EXAMPLES Examples of the polycondensation reaction method according to the present invention will be specifically described below with reference to polymerization examples of polyethylene terephthalate. As the continuous polycondensation reactor, the continuous polycondensation reactor shown in FIG. 1 was used. (Example 1) 350 wtppm antimony trioxide as a catalyst and 300 wtppm triphenyl phosphate as a stabilizer were added to a raw material slurry in which terephthalic acid and ethylene glycol were mixed at a molar ratio of 1.0: 1.5. The esterification reaction was carried out at a temperature of 260 ° C. in a two-stage esterification reaction tank with a residence time of 4.5 hours and 2 hours, respectively, to obtain a prepolymer having a reaction rate of about 95%. next,
The temperature of this prepolymer is 270 ° C. and the pressure is 1.0 mmHg.
Prepolymerization is performed for about 1 hour under the conditions described above, and the intrinsic viscosity of the obtained polymer is measured by using a mixed solvent of phenol and 1,1,2,2-tetrachloroethane in a weight ratio of 4 to 6 at 20 ° C. When measured with a meter, the intrinsic viscosity was 0.60 dl / g. Next, this polymer was continuously supplied so as to maintain a thickness of 1.0 mm on the conveying member of the continuous polycondensation reaction apparatus according to the present invention controlled at a temperature of 300 ° C., and the polymer surface had a pore diameter of 0.7 mm.
Nitrogen gas heated to a temperature of 300 ° C. was jetted from the circular nozzle at a flow rate of about 400 m / s to renew the surface, and polymerized for a residence time of 3 minutes. The obtained polymer has an intrinsic viscosity of 0.79.
It was dl / g.

Example 2 The same experiment as in Example 1 was carried out except that the injection speed of nitrogen gas was changed to about 170 m / s, and a polymer having an intrinsic viscosity of 0.72 dl / g was obtained.

Example 3 The same experiment as in Example 1 was conducted except that the temperature of the inside of the continuous polycondensation reactor according to the present invention and the injected nitrogen gas was changed to 285 ° C.
A polymer with an intrinsic viscosity of 0.71 dl / g was obtained.

[0026]

As described above, according to the continuous polycondensation reaction method and the apparatus thereof of the present invention, the surface of the liquid to be treated supplied in the form of a film is treated by the inert gas jetted at a high speed from the fine pore nozzles. By advancing the polycondensation reaction while renewing, it is possible to increase the frequency of contact between the liquid to be treated and the inert gas, and to accelerate the evaporation of volatile substances generated in the reaction process in the liquid to be treated. It is possible to shorten the time.

[Brief description of drawings]

FIG. 1 is a schematic view of an example of a continuous polycondensation reaction device according to the present invention.

FIG. 2 is a schematic view of a cylindrical rotor 2b installed inside the apparatus main body in the continuous polycondensation reaction apparatus of FIG.

FIG. 3 shows an example of an array of fine hole nozzles 15 for injecting the inert gas shown in FIG.

[Explanation of symbols]

1 device body 2a Cylindrical rotor in the upper part of the device 2b Cylindrical rotor in the lower part of the device 2c Cylindrical rotor outside the device 3 Transport members 4 Liquid supply slitting device 5 Transport member heating device 6 Liquid to be processed cooling device 7 Cylindrical roller for feeding the transport member 8 Fine nozzle piping 9 Gas seal device 10 Piping for sending inert gas 11 condenser 12 Inert gas heating device 13 Scraping device 14 compressor 15 Small nozzle

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08G 63/00-63/91 C08G 85/00

Claims (6)

(57) [Claims] 1. A film-shaped product obtained by supplying a liquid to be treated to one surface of a conveying member while moving the conveying member stretched between a plurality of cylindrical rotors installed in the main body of the apparatus. When the liquid to be treated moves in the main body of the apparatus, an inert gas heated to a predetermined temperature is jetted from a plurality of fine pore nozzles onto the surface of the liquid to be treated in the film to be treated. A continuous polycondensation reaction method, which comprises renewing the surface of a polycondensation reaction to proceed the polycondensation reaction. 2. The film-shaped liquid to be treated on the conveying member has a thickness of 0.5 to 5 mm, and an average cross-sectional flow velocity of the inert gas ejected from the tip of the pore nozzle is 50.
To 400 m / s, and the gap between the tip of the pore nozzle and the surface of the film-shaped liquid to be treated is 5 to 100 mm,
The installation interval of the pore nozzles arranged in a direction perpendicular to the traveling direction of the film-shaped liquid to be treated is 1 to 20 m.
m is set, The continuous polycondensation reaction method of Claim 1 characterized by the above-mentioned. 3. The inside of the main body of the apparatus is set to an inert gas atmosphere in a normal pressure or slightly pressurized state, and the inert gas containing volatile substances generated in the reaction process is stored in a condenser installed outside the apparatus. After being sent and cooled to recover the volatile substance, it is reheated to a predetermined temperature and sprayed onto the surface of the film-shaped liquid to be treated from a plurality of the fine hole nozzles to circulate in the main body of the device. The continuous polycondensation reaction method according to claim 1 or 2. 4. A plurality of cylindrical rotors installed inside and outside the main body of the apparatus, a conveying member stretched between the cylindrical rotors, a drive device for moving the conveying members, and the moving conveyer. A heater for preheating the member before entering the apparatus main body, a treated liquid supply device for supplying the treated liquid to the surface of the conveying member, and an inert film on the surface of the obtained film-shaped treated liquid. A plurality of pore nozzles for injecting gas, a cooler that cools the film-shaped liquid to be processed after it is discharged from the inside of the device body, and the film-shaped liquid to be discharged from the device body. A cylindrical rotor having a scraping device for scraping the film-shaped liquid to be treated, the cylindrical rotor facing the surface of the film-shaped liquid to be treated and being placed in the main body of the device can be kept in a non-contact state with the film-shaped liquid to be treated. Continuous heavy reduction characterized by a structure Combined reaction device. 5. The continuous polycondensation reaction apparatus according to claim 4, wherein the cross-sectional shape of the tip of the pore nozzle is a circle or an ellipse having a diameter or long axis of 0.5 to 3 mm. 6. The continuous polycondensation reaction apparatus according to claim 4, wherein the cross-sectional shape of the tip of the pore nozzle is a slit shape having a width of 0.5 to 3 mm.