JPH1095843A - Method and equipment for continuous reaction of polyester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for producing a polyester wherein the rate of polymerization and yields are greatly increased as compared with the conventional processes by continuous melt polymerization and a good-quality polyester with less terminal carboxyl groups can be produced. SOLUTION: In continuously producing a polyester by continuously feeding raw materials and/or reactants for producing a polyester into a cylindrical horizontal reactor 1 and allowing the reaction to proceed while the raw materials and/or reactants are moved toward the outlet of the reactor 1, the movement of the raw materials and/or reactants is effected by rotating the reactor 1 on the central axis of the cylinder while scraping up the raw materials and/or reactants along the inner wall of the reactor 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for continuously reacting a polyester, and more particularly to an apparatus for continuously performing a reaction such as a polymerization reaction while supplying raw materials and / or reactants to a cylindrical reaction tank. The present invention relates to a continuous reactor for polyester.

[0002]

2. Description of the Related Art Polyesters represented by polyethylene terephthalate and polybutylene terephthalate have been widely used in various applications because of their excellent physical and chemical properties. In particular, by using the fiber as a linear object, the film as a planar object, and the resin molded product as a three-dimensional object, its excellent strength, performance such as heat resistance, etc., has raised its commercial value, It is widely used as garments and industrial fibers requiring durability, especially rotating guide rail cords, and engineering plastics.

As a method for producing such a useful polyester, there is generally a direct polymerization method or a transesterification method. Here, the former direct polymerization method is a method in which an acid component and a diol component are directly subjected to an esterification reaction to produce a polyester precursor, and then the polyester low polymer is subjected to polycondensation under reduced pressure to produce. . In the latter transesterification method, a lower alkyl ester of an acid component is transesterified with a diol to produce a polyester precursor,
Then, the polyester precursor is polycondensed under reduced pressure to produce the polyester precursor. In such a method for producing polyester, switching from a batch polymerization method to a continuous polymerization method has been promoted in order to produce polyester at low cost by taking advantage of its economies of scale.

[0004] However, such a continuous polymerization system has many problems such as a decrease in yield, an improvement in quality, a uniform degree of polymerization, and an improvement in operability, although the advantage of scale can be utilized as described above. I have. Further, in the production of polyester, in the esterification reaction, transesterification reaction and polycondensation reaction, it is necessary to carry out the reaction at a high temperature for a long period of time. Increases, and a problem easily occurs in hydrolysis resistance. For this reason, it is a common practice to provide a stirring blade in each reaction tank and forcibly stir the reactants to cause the reaction to proceed while applying strong shear, thereby trying to advance the reaction. However, in this case, the thermal decomposition of the obtained polyester is rather accelerated, which is not easy.

[0005] In order to solve these problems, polyester is produced by shortening the residence time of reactants in a reaction tank as much as possible by reacting at a high reaction rate without promoting thermal decomposition of the polyester. Is preferred. For these reasons, many methods for shortening the reaction time in a reaction tank have been proposed and put into practical use.

One such conventional method is a thin-film reactor in which a reactant is made into a thin layer and reacted in order to quickly separate and remove by-products such as glycols in a polyester polycondensation reaction. Or using vigorous stirring to increase the evaporation area to facilitate evaporation and increase the reaction rate. The thin-film reactor is provided with a stirring blade to agitate the reactant to increase the evaporation area, and to spontaneously flow the reactant using the wetted wall to increase the evaporation area;
The reaction product is made into a thin filamentous body to increase the evaporation area of by-products.

[0007] Here, with regard to particularly, a large number of reaction tanks having stirring blades devised so as to have a high stirring efficiency and a large free surface area of the reactant from each manufacturer are commercially available. However, these reaction tanks require intense stirring and require a large amount of stirring power, which wastes energy and is not preferable. In addition, there is a problem that a dead space is generated in the reaction tank or a scattered polymer or the like stays for a long time, so that a reaction product is deteriorated and is mixed into a product as a foreign substance.

As a technique for accelerating a reaction other than the thin film polymerization reaction tank, a method of introducing an inert gas into the reaction tank is proposed, for example, in Japanese Patent Publication No. 51-44039. The method is a continuous melt polymerization method of polyester using an inert gas, in which an inert gas is blown into thin bubbles in a reaction solution in a reaction tank, and thereby the reaction solution is stirred to form an alkylene glycol or the like. This is a method in which by-product vapor is diffused into inert gas bubbles in the reaction solution. However, in this method, it is necessary to disperse the raw material liquid flowing down by centrifugal force and collide against the inner wall of the tower. This requires power, which causes an increase in energy consumption and formation of a dead space. There is also a problem.

In Japanese Patent Publication No. 4-58806,
In a heated inert gas atmosphere, screw- (β
A method for continuously extruding a (hydroxyalkyl) terephthalate and / or a low-polymer precondensate thereof is disclosed. However, if the diameter of the die is increased in order to process a large amount of reactants, a sufficient reaction rate cannot be obtained and it is difficult to say that it is practical.

With respect to the above-described reaction tank itself,
All are fixedly installed without rotating, and there is no idea of rotating the reaction tank itself.

Slightly, a reaction apparatus using a rotary body type reaction tank having a helical non-rotating fixed blade therein has been proposed, for example, in Japanese Patent Publication No. Sho 42-26170. However, the helical fixed blade of the reactor only has the effect of simply sending the reactant to the outlet side, and cannot expect the effect of actively updating the surface of the reactant at all. Further, Japanese Patent Publication No. 48-17470 discloses a polymer processing and transporting apparatus provided with a right-angled cylinder having radial holes and a spiral cantilever blade. However,
In this apparatus, since the surface of the gas phase is not sufficiently renewed, the polymer scattered and adhered in the apparatus causes deterioration due to stagnation and becomes a foreign substance.

[0012]

In view of the above-mentioned problems, the problem to be solved by the present invention is that there is no deterioration due to long-term residence of the polyester, and the reaction rate can be greatly increased. An object of the present invention is to provide a reactor for continuously obtaining high-quality polyester having a small number of carboxyl terminals which promotes hydrolysis of a polymer.

[0013]

According to the present invention, as a first aspect of the present invention, raw materials and / or reactants for producing polyester are continuously supplied to a cylindrical horizontal reaction vessel. In a method for continuously producing polyester by causing a reaction to proceed while moving a raw material and / or a reactant to an outlet side of a reaction vessel, the reaction vessel is rotated around a central axis of a cylinder, and the raw material and / or Alternatively, a polyester continuous reaction method is provided in which the reactant is moved to the outlet side of the reaction vessel while being scraped up along the inner wall of the reaction vessel by a scraping means.

According to a second aspect of the present invention, there is provided a supply port for continuously supplying a raw material and / or a reactant for producing a polyester, and an outlet for removing the polyester obtained by the reaction. A rotating means for rotating the cylindrical horizontal reaction vessel around the central axis of the cylinder, and a rotating means provided inside the horizontal reaction vessel and staying at the bottom of the horizontal reaction vessel. A continuous polyester reaction device is provided, which comprises a scraping means for scraping the above-mentioned raw materials and / or reactants along the inner wall of the reaction vessel.

According to a third aspect of the present invention, there is provided a continuous polyester reactor according to the second aspect, wherein the horizontal reaction vessel is inclined downward from the horizontal toward the outlet side.

According to a fourth aspect of the present invention, there is provided a polyester continuous reactor according to the second or third aspect, wherein two or more partition plates having openings are provided on the inner wall surface of the horizontal reaction vessel. Is done.

[0017]

Embodiments of the present invention will be described below in detail.

In the present invention, the polyester and the reactant include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polybutylene isophthalate monomers, low polymers and high polymers. And a polyester produced from a dicarboxylic acid having an aromatic dicarboxylic acid as a main component or an ester-forming derivative thereof, an alicyclic dicarboxylic acid, or an aliphatic dicarboxylic acid and a diol component as raw materials. Examples of the dicarboxylic acid having an aromatic dicarboxylic acid component as a main component or its ester-forming derivative include terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6 -Naphthalenedicarboxylic acid and / or a lower alkyl ester thereof (the alkyl group usually has 1 to 4 carbon atoms).
The alicyclic dicarboxylic acid component includes, for example, cyclohexanedicarboxylic acid, and the aliphatic dicarboxylic acid includes adipic acid, sebacic acid, suberic acid, and the like. Of these, terephthalic acid, 1,
4-naphthalenedicarboxylic acid, isophthalic acid, and dimethyl terephthalate. These aromatic dicarboxylic acid component, alicyclic dicarboxylic acid component and aliphatic dicarboxylic acid component may be used alone or in combination of two or more.

The diol component includes ethylene glycol, neopentyl glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and 1,5-pentane. Examples thereof include diol, 1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, diethylene glycol, triethylene glycol, polyalkylene glycol, and propylene glycol. Of these, ethylene glycol, 1,4-butanediol and diethylene glycol are preferred. In addition, even if these glycol components are used alone,
Two or more kinds may be used in combination.

The polyester may be copolymerized with a compound such as a trifunctional or higher polyfunctional compound such as trimellitic acid, pyromellitic acid or glycerol, or a monofunctional compound such as benzoic acid or phenyl isocyanate.

In the present invention, when producing the polyester, a catalyst may or may not be present, whichever may be used, but it is usually preferable to use a catalyst. However, when a catalyst is used, any of commonly used catalysts may be used.Examples of these catalysts include an antimony compound, a manganese compound, a titanium compound, a tin compound, a zinc compound, and a magnesium compound. No. Further, if necessary, one or more kinds of other commonly used thermoplastic resins, additives, inorganic fillers, organic fillers, etc. are directly kneaded at the output side of the continuous reaction apparatus of the present invention. It can also be kneaded with a machine or the like. further,
Examples of other thermoplastic resins include polyester resins, polyamide resins, polystyrene resins, polycarbonates, polyacetals, and the like. As additives, known antioxidants, antistatic agents, brominated polycarbonates, flame retardants such as brominated epoxy compounds, antimony trioxide, flame retardant aids such as antimony pentoxide, plasticizers, lubricants, Examples thereof include a release agent, a colorant, and a crystal nucleating agent. Examples of inorganic fillers include metals such as glass fiber, talc, mica, glass flakes, carbon fiber, silica, alumina fiber, milled glass fiber, clay, carbon black, kaolin, titanium oxide, iron oxide, antimony oxide, and alumina. Examples thereof include compounds, alkali metal compounds such as potassium and sodium. Examples of the organic filler include aromatic polyester fibers and liquid crystalline polyester fibers.

Hereinafter, the continuous reaction method of polyester according to the present invention and its apparatus will be described in detail with reference to the drawings.

FIG. 1 is a front view schematically illustrating a continuous reaction apparatus for polyester of the present invention. In the figure,
Reference numeral 1 denotes a cylindrical horizontal reaction vessel, reference numerals 2a and 2b denote rotating guide rails fixed to the horizontal reaction vessel, reference numerals 3a and 3b denote a pair of gears meshing with each other, and reference numeral 4 denotes a rotation guide rail 2a and 2b. And a pair of guide rollers (only one guide roller is shown in FIG. 1), respectively, and a rotating means 5 for a horizontal reaction vessel (usually a variable speed motor with a speed reducer is used). Are shown).

Here, inside the horizontal reaction vessel 1, a scraping means for scraping the raw material and / or reactant staying at the bottom of the reaction vessel 1 along the inner wall of the reaction vessel 1, That is, a scraping wing is attached. Further, on the rotating body of the reaction vessel 1, rotating guide rails 2a and 2b and a gear 3 are attached.
A pair of guide rollers 4a and 4b are provided below each rotating guide rail. It is preferable that the guide rollers 4a and 4b be capable of absorbing a certain degree of expansion and contraction in the vertical and horizontal directions of the reaction vessel 1 that is linearly expanded by heating.

In the horizontal continuous reaction apparatus described above, the driving force of the rotating means (motor) 5 is transmitted to the gear 3b (fixed to the reaction vessel 1) and 3a which mesh with each other, whereby the reaction vessel 1 is rotated about the central axis of the cylinder. The type and number of the rotation means 5 are not particularly limited, and the rotation speed can be controlled by inverter control as needed. At this time, rotating guide rails 2a and 2b are fixed to the rotating body of the reaction vessel 1 so that rotation can be performed smoothly, and a pair of guides respectively engaging with the rotating guide rails 2a and 2b are provided. It is rotatably supported by rollers 4a and 4b. further,
The reaction vessel 1 can be inclined downward from the horizontal toward the outlet side, so that the movement of the reactant in the reaction vessel can be maintained from the inlet side to the outlet side, and a stable flow of the reactant can be maintained. .

Since the reaction vessel 1 is rotated, the continuous reaction apparatus rotates when supplying the raw material for producing the polyester and / or its reactant and taking out the reactant after the completion of the reaction. Joint 6b
And 6a. Therefore, the supply of the raw material and / or its reactant is performed from the supply port 7 attached to the rotary joint 6b, and the withdrawal of the reactant after the reaction is completed.
a from the outlet 8 attached to the a.

Further, in order to introduce an inert gas into the continuous polyester reaction apparatus of the present invention to promote the reaction, an inert gas is continuously introduced from a supply port 12 attached to the rotary joint 6a. Glycols by-produced in the reaction may be accompanied by the action of the inert gas and exhausted from the exhaust port 13 attached to the rotary joint 6b. The method for introducing such an inert gas is not particularly limited, but it is preferable to introduce the inert gas into the gas phase in the reaction vessel and / or into the liquid of the reactant. On the other hand, it is preferred to introduce them in countercurrent. Examples of such an inert gas include N ₂ , Ar, He and the like. Among them, nitrogen is preferable because it is inexpensive and easily available, and the reaction temperature is not adversely affected. It is more preferable to reduce the water content of the inert gas or to introduce it by heating beforehand. The amount of the inert gas introduced is not particularly limited, but is preferably as large as possible in order to promote the reaction, and can be circulated and reused from an economical point of view.

Reference numerals 9 and 10 denote an inlet pipe and an outlet pipe of a heat medium for supplying and discharging a heat medium such as steam or dow sum for heating the reaction solution in the reaction vessel 1, respectively. A known heating means such as electric heating or high frequency heating can be used without being limited to the heating means using a medium.

In the polyester continuous reaction apparatus configured as described above, the raw materials and / or reactants for producing the polyester are continuously supplied from the supply port 7 to the rotating reaction vessel 1. Then, the reaction liquid is moved up to the outlet while wetting the surface of the inner wall of the reaction vessel by being scraped up along the inner wall of the reaction vessel 1 by the scraping means provided in the reaction vessel 1, and the reaction proceeds. The liquid is discharged from the outlet 7.

In the present invention, as the scraping means, various scraping blades as shown in FIGS. 2A to 2C can be used. It is not limited to the above.

Here, the scraping means will be described in detail with reference to FIG. 2 (a sectional side view of the reaction vessel 1). In this figure, the reaction vessel 1 has a double cylindrical structure. This forms a jacket through which the heat medium for heating the reaction vessel 1 can pass. Further, reference numerals 14 and 15 indicate a scraping means and a partition plate, respectively, and in FIG. 2A, four flat scraping blades 14a to 14a to
14d is fixed in such a manner as to extend longitudinally and radially between the partition plates 15, and the partition plate 15 is fixed to the inner wall of the inner cylinder of the reaction vessel 1 having a double cylindrical structure. The partition plate 15 has a donut shape, and a hole (H) through which a reactant passes is provided inside the partition plate 15. Further, FIG.
The scraping means 14 shown in FIG. 2 (b) is a plate-shaped scraping wing having four half-moon-shaped cross sections, unlike the flat scraping wings 14a to 14d of FIG. -(c) illustrates eight rod-shaped scraping wings, respectively. In addition, as another specific example of the scraping wings, in addition to the rod-shaped or plate-shaped members shown in FIG. 2, a wire mesh or lattice-shaped member may be used.

In addition to the effect of scraping the reaction solution along the inner wall of the reaction vessel 1, the effect of transferring the reactant to the reaction vessel 1 in the longitudinal direction of the reaction vessel 1 can be provided to the scraper blades. For this purpose, the scraping blades are not provided in parallel with the central axis direction of the cylindrical reaction vessel 1, but are parallel to the central axis of the reaction vessel 1 such that the reaction solution is extruded in the longitudinal direction of the reaction vessel 1. From the arrangement, it may be installed with a certain degree of inclination.

As described above, the function of the scraping means 15 of the present invention is as follows.
It is required that the surface of the reaction solution is renewed and the heat transfer efficiency is promoted by lifting and dropping the reaction solution. Further, in order to suppress the formation of a dead space, it is important that the surface of the scraping blade contacts the reactant during one rotation of the scraping blade together with the reaction vessel 1. Here, it is preferable that the scraping means 14 is fixed to a partition plate with a small gap between the inner wall and a large part of the inner surface in the longitudinal direction of the reaction vessel 1.

The rotation speed of the reaction vessel 1 is
Since it varies depending on the production conditions of the polyester, it may be appropriately selected within a range suitable for each production condition so as not to impair the effects of the present invention. Also, the liquid depth of the reactant in the reaction vessel is preferably smaller than the inner diameter of the reaction vessel, whereby the glycol removal reaction proceeds and a high reaction rate is obtained. However, in this case, it is important that the exhaust (degassing) of the glycols generated in the reaction is not hindered. In order to achieve this object, the introduction of the inert gas into the reaction vessel 1 is required. It is also preferable to take measures such as:

In the reaction vessel 1 of the continuous reaction apparatus of the present invention, the inside of the reaction vessel 1 can be partitioned into two or more places by a partition plate 15 provided with an opening through which the reactant flows. Can be controlled. The number, shape, opening position, etc., of the openings of the partition plate referred to here may be appropriately selected and used as necessary. For example, a wire mesh, a punching plate, a donut having a round hole at the center of the partition plate. Disk (Fig. 2
And the like can be suitably used.

Further, a member for promoting agitation and mixing of reactants other than the scraper blades may be provided inside the reaction vessel of the continuous reaction apparatus of the present invention. Examples of the member that promotes stirring / mixing here include a spiral stirring blade member, a rod-shaped or plate-shaped stirring blade member, and the like. Further, a plurality of these members or a combination of a plurality of these members can be used.

When the polyester is continuously produced using the method and apparatus for continuous reaction of the polyester of the present invention, application to the polyester reaction tank generally called an esterification reaction tank, a transesterification reaction tank and a polycondensation reaction tank. Is possible. It goes without saying that reaction conditions such as pressure and temperature may be appropriately selected and used as appropriate for the reaction.

[0038]

EXAMPLES Examples and comparative examples of the present invention will be described in detail below with respect to typical polyesters such as polybutylene terephthalate and polyethylene terephthalate. However, the present invention is not limited to these examples. Is natural.

The “intrinsic viscosity [η]” referred to in the following Examples and the like is a value calculated from the melt viscosity measured at 25 ° C. in orthochlorophenol. The “terminal carboxyl group concentration ([COOH])” is determined by the method of A. Conix (Makromol. C).
hem, a number of equivalents of polymer per 10 ⁶ g as measured by the 226 (1958)}.

In the following Examples and the like, parts indicate proportions expressed by weight.

Example 1 10 kg of dimethyl terephthalate
/ hr, 6.5 kg / hr of 1,4-butanediol and 0.007 kg / hr of titanium tetrabutoxide were supplied to the supply port 7
It is continuously supplied to the continuous reactor of FIG. 1 installed more horizontally,
The transesterification reaction was carried out so that the temperature inside the reaction vessel was gradually increased from 160 ° C. to 170 ° C. by heating the gas phase heating medium under normal pressure. At this time, the reaction vessel 1 of the continuous
Inside, a wire mesh cylindrical member is installed as a scraping means, and with the rotation of the reaction vessel, the reactant is scraped up along the inner wall of the reaction vessel 1 by the wire mesh, and the scraped-up reactant is dropped. did. Then, the reaction vessel of the continuous reaction apparatus was rotated at 3 rpm by the rotating means 5, and [η] of the low-polymer polybutylene terephthalate was 0.08,
[COOH] = 3 eq / T was obtained. The resulting polybutylene terephthalate low polymer has an extremely good hue,
At this time, the transesterification rate was calculated from the amount of methanol distilled from the exhaust port 11 to be about 92%. Under these conditions, the polyester continuous reaction apparatus was continuously operated for 30 days, but no contamination was found by visual inspection at all, which appeared as deterioration of the reaction product.

The polybutylene terephthalate low polymer thus obtained was further continuously supplied at a flow rate of about 13 kg / hr to the continuous reactor of FIG.
Under the conditions described above, the polycondensation reaction was carried out at 236 ° C. by heating the liquid phase with a heating medium. At this time, inside the reaction vessel 1 of the continuous reaction apparatus, eight flat plates were provided at a constant interval in the longitudinal direction with a slight gap provided between the inner wall and the reactant. Was caused to fall and fall. In addition, ten partition plates having an opening at the center are provided in the reaction vessel 1, and the rotation means 5 rotates the reaction vessel 1.
Was rotated at 1.5 rpm. Then, the polybutylene terephthalate obtained from the outlet 8 has [η] = 0.5.
7 and [COOH] = 6 eq / T. The hue was also very good, and the transesterification rate calculated from the amount of methanol distilled from the exhaust port 11 was about 99.9%. Further, continuous operation was performed for 30 days under these conditions, but there was no foreign matter mixed in visually. In addition,
In carrying out the above reaction, no inert gas was introduced into the reaction vessel 1.

Comparative Example 1 10 kg of dimethyl terephthalate
/ hr, 6.5 kg / hr of 1,4-butanediol, and 0.0007 kg / hr of titanium tetrabutoxide are continuously supplied to a rigid reactor equipped with a stirrer, and heated in a gaseous phase heating medium under a normal pressure to the inside of the reaction vessel. Was subjected to a transesterification reaction such that the temperature gradually increased from 160 ° C. to 170 ° C. The polybutylene terephthalate low polymer obtained at this time is
[Η] = 0.06, [COOH] = 13 eq / T, the hue was slightly yellow, and the transesterification rate calculated from the amount of methanol distilled out was about 76%. In addition, as a result of the continuous operation for 30 days under these conditions, no foreign matter was clearly visible, but unreacted dimethyl terephthalate and oligomer sublimates remained on the inner wall of the gas phase of the rigid reactor. It was confirmed that it was adhered to.

Subsequently, the obtained polybutylene terephthalate low polymer was continuously supplied to a screw-type horizontal biaxial reactor, and subjected to polycondensation at a temperature of 236 ° C. by heating a liquid phase with a heating medium under a vacuum of 2 Torr. Reacted. The obtained polybutylene terephthalate has [η] = 0.33,
[COOH] = 16 eq / T, the hue was yellow, and the transesterification rate calculated from the amount of methanol distilled was about 97%. Then, the continuous operation was carried out for 30 days under these conditions. However, on the seventh day after the start of the continuous operation, the incorporation of brownish deteriorating substances, which can be clearly seen visually, continued to be observed.

[Example 2] Esterification of 8.6 kg / hr of terephthalic acid and 5.5 kg / hr of ethylene glycol was carried out in a continuous esterification reactor at a reaction temperature of 274 ° C under normal pressure. And 1 so that the exit side is lower than horizontal.
Polyethylene terephthalate low polymer obtained in the continuous reactor of FIG. 1 installed at an angle of 0 ° (average degree of polymerization is about 8)
0.04 parts of antimony trioxide was added to
The polycondensation reaction was performed at a reaction temperature of 281 ° C. by heating with a gaseous heating medium at a vacuum of 3 Torr. At this time, 16 semi-moon-shaped scraping means are installed at regular intervals in the longitudinal direction with a gap between the inside of the reaction vessel 1 of the continuous reaction apparatus and a gap between the inside of the reaction vessel and the rotation of the reaction vessel. At the same time, the reactants were lifted up and dropped. Further, eight partition plates having an opening at the center are provided in the reaction vessel 1,
, The reaction vessel 1 was rotated at 2.5 rpm.
At this time, the polybutylene terephthalate obtained from the outlet 8 has [η] = 0.53, [COOH] = 19 eq /
The color was T, the hue was extremely good, and continuous operation was carried out for 30 days under these conditions, but no foreign matter was visually observed.

Example 3 The procedure was carried out using the continuous reactor of FIG. 1 except that nitrogen as an inert gas was introduced into the reaction vessel 1 at a flow rate of 30 Nm ³ / hr in a countercurrent to the flow of the reactants. The same conditions as in Example 2 were used. [Η] of polybutylene terephthalate extracted from the outlet 8 is 0.63, [CO
OH] = 16 eq / T, and the hue is also very good.
Under these conditions, continuous operation was performed for 30 days, but there was no foreign matter mixed in visually.

Comparative Example 2 The polyethylene terephthalate low polymer of Example 2 was continuously supplied to a screw-type horizontal biaxial reactor, and subjected to polycondensation at a reaction temperature of 281 ° C. by heating with a vacuum of 3 Torr and a gaseous heating medium. Reacted. The polyethylene terephthalate thus obtained is
[Η] = 0.26, [COOH] = 85 eq / T,
The hue was yellow, and continuous operation was performed for 30 days under these conditions. However, mixing of brownish-deteriorated substances visually observed on the fifth day from the start of the continuous operation was continuously observed.

[0048]

As described above, according to the present invention,
Compared to conventional polyester continuous reactors and manufacturing methods, the polymerization rate is greatly increased, the yield is also improved, and polyester with good quality with less carboxyl terminals and foreign substances can be manufactured. It has a very remarkable effect as a continuous reaction apparatus and a production method for raw materials.

[Brief description of the drawings]

FIG. 1 is a front view schematically showing a continuous polyester reaction apparatus of the present invention.

FIG. 2 is a front sectional view of a reaction vessel schematically shown for illustrating a scraping means (scraping blade) of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reaction container 2a, 2b Rotating guide rail 3a, 3b Gear 4a, 4b A pair of guide rollers 5 Rotating means 6a, 6b Rotary joint 7 Supply port 8 Discharge port

Claims (4)

[Claims] 1. A raw material and / or a reactant for producing polyester is continuously supplied to a cylindrical horizontal reaction vessel, and the reaction is performed while moving the raw material and / or the reactant to an outlet side of the reaction vessel. In which the reaction vessel is rotated around the central axis of the cylinder, and the raw materials and / or reactants are scraped up along the inner wall of the reaction vessel by a scraping means. While moving the reaction vessel to the outlet side of the reaction vessel. 2. A supply port for continuously supplying raw materials and / or reactants for producing polyester,
A cylindrical horizontal reaction vessel having an outlet for taking out the polyester obtained by the reaction, a rotating means for rotating the cylindrical horizontal reaction vessel around the central axis of the cylinder, A continuous polyester reaction device, which is internally provided and includes a scraping means for scraping the raw material and / or reactant remaining at the bottom of the horizontal reaction vessel along an inner wall of the reaction vessel. 3. The continuous polyester reactor according to claim 2, wherein the horizontal reaction vessel is inclined downward from the horizontal toward the outlet side. 4. The continuous polyester reactor according to claim 2, wherein two or more partition plates having openings are provided on the inner wall surface of the horizontal reaction vessel.