JP2002201261A - Process for producing polyester or its copolymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for producing a polyester or its copolymer that can produce a high quality polyester or its copolymer with a high polymerization degree by enhancing the reactivity of esterification of a dicarboxylic acid and a diol in the direct polymerization process with consequent improvement in the reactivity of the following polycondensation reaction. SOLUTION: The production of a high quality polyester or its copolymer with a high polymerization degree can be achieved by the process for producing a polyester or its copolymer which comprises carrying out the esterification reaction of a dicarboxylic acid composed mainly of an aromatic dicarboxylic acid and a diol composed mainly of 1,4-butanediol and 0-90 wt.%, based on the total polymer, polyalkylene ether glycol having a number-average molecular weight of 600-4,000 in the presence of an organic titanium compound, followed by polycondensation reaction, wherein the esterification reaction is carried out under such conditions that a peripheral speed of an agitating blade in the tank is not less than 0.5 m/sec and the difference in height between the highest level and the lowest level of the reaction fluid in the tank is not more than 1/4 of the internal diameter of the tank.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a process for producing a batch type or continuous type polyester or a copolymer thereof, and more particularly to a process for producing a dicarboxylic acid mainly composed of an aromatic dicarboxylic acid and a diol mainly composed of 1,4-butanediol. Since the esterification reaction can be carried out with high reactivity, the reactivity of the subsequent polycondensation reaction can be improved, and as a result, a high-quality polymer can be industrially advantageously obtained, thereby producing a polyester or a copolymer thereof. About.

[0002]

2. Description of the Related Art A polyester comprising an aromatic dicarboxylic acid and 1,4-butanediol and a copolymer thereof are excellent in mechanical properties, moldability, heat resistance, chemical resistance and the like. As a molding resin for parts, automobile parts, electric and electronic parts, and the like, it is used in a wide range of applications from fibers and films to general consumer goods. In particular, a polyetherester block copolymer comprising an aromatic dicarboxylic acid, 1,4-butanediol and a polyalkylene ether glycol has excellent properties as a thermoplastic elastomer.

[0003] The production method of this polyester has been
Dicarboxylic acid and diol are first subjected to an esterification reaction,
Next, it is roughly divided into two groups: direct polymerization method by polycondensation, transesterification reaction of dialkyl dicarboxylate and diol first, and then transesterification polymerization method by polycondensation.The latter manufactures raw materials of dialkyl dicarboxylate. In this case, a raw material production cost is increased due to the need for a step of transesterification of a dicarboxylic acid, and separation and recovery of by-product tetrahydrofuran (hereinafter, referred to as THF) is difficult, so that it is difficult to use it effectively.
It is said that the production cost of 1,4-butanediol-based polyester is disadvantageous compared to the former direct polymerization method.

On the other hand, the dicarboxylic acid raw material of the direct polymerization method is as follows:
Compared to dialkyl dicarboxylates, which are easily soluble in diol components, they are hardly soluble in diol components, and furthermore, have the property that the organic titanium compound is easily deactivated by water produced by the esterification reaction. Due to this characteristic, when the two are compared in terms of reaction with the diol component, the esterification reaction of the dicarboxylic acid in the solid-liquid (slurry) state is compared with the transesterification reaction of the dialkyl dicarboxylic acid in the liquid-liquid state. Therefore, there is a problem that the reactivity of the main reaction is inferior and it is difficult to suppress the side reaction, and this improvement is important. As a conventionally known countermeasure method, there are many known examples in which a molar ratio of a diol component to a dicarboxylic acid component and a catalyst formulation, and further, reaction conditions such as temperature and pressure are specified, for example, when producing polybutylene terephthalate. Regarding the esterification reaction of terephthalic acid with 1,4-butanedil, JP-A-48-47594, JP-A-49-57092, and JP-A-51-37187.
A gazette is known.

[0005]

However, in order to further improve the esterification reactivity in the direct polymerization method, there is a limit only in specifying the reaction conditions, and the conventional countermeasures have been insufficient. Further, in the production of the polyetherester block copolymer, it is necessary to use a polymer having a higher degree of polymerization in order to enhance the performance of the elastomer. Therefore, it is required to further increase the esterification reactivity.

Accordingly, the present invention provides a process for producing a high-quality polyester or copolymer thereof having a high degree of polymerization by improving the esterification reactivity of a dicarboxylic acid and a diol by a direct polymerization method. The purpose is to:

[0007]

Means for Solving the Problems In order to achieve the above object, the present inventors, in addition to the reaction conditions of the esterification reaction in the production of polyester by the direct polymerization method, have a reaction apparatus, particularly an esterification reaction tank. Focusing on the liquid surface state and reactivity related to the circulating flow direction of the reaction liquid in the reactor, as a result of careful investigation, by setting the peripheral speed of the stirring blade and the reaction liquid surface state in the reaction tank under specific conditions, The inventors have found that the reactivity of the esterification reaction is remarkably improved, and the reactivity of the subsequent polycondensation is also improved.

That is, the object of the present invention is to provide a dicarboxylic acid containing an aromatic dicarboxylic acid as a main component, a diol containing a 1,4-butanediol as a main component, and 0 to 90% by weight of the total polymer. Molecular weight 600-4000
When an esterification reaction is carried out from the polyalkylene ether glycol in the presence of an organic titanium compound and then a polycondensation reaction is carried out to produce a polyester or a copolymer thereof, the esterification reaction is carried out at a peripheral speed of a stirring blade in a tank of 0. .5m /
and a method for producing a polyester or a copolymer thereof, which is carried out under the condition that the height difference of the reaction liquid surface in the tank is not more than 1/4 of the inner diameter of the tank.

In addition, a stirring shaft that can be rotated from outside the tank is installed at the center of the tank, and the shaft has a lattice blade having a bottom paddle at the lower end, or a plurality of blades that are vertically positioned and whose plane directions intersect each other. Esterification reaction is carried out using a stirring reaction tank equipped with stirring blades having flat blades and fixed on the inner wall surface of the tank from the bottom to the top with multiple baffles along the rotation axis at intervals. It is a preferred embodiment of the present invention that the esterification reaction is performed in the presence of the organic titanium compound and the organic tin compound and the molar ratio of the diol to the dicarboxylic acid ranges from 1.2 to 2.2.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

First, the stirring reaction tank used in the ester reaction of the present invention will be described. In general, the state of the reaction liquid surface in the tank varies depending on the type of the reaction liquid and the amount charged,
It is also greatly affected by the stirring conditions such as the shape of the inner wall surface of the tank, the shape of the stirring blade, and the stirring speed. When the direction of the circulating flow by stirring is close to the direction perpendicular to the stirring shaft and the side wall surface (hereinafter referred to as the lateral direction), the reaction liquid level in the tank is usually the lowest at the center around the stirring axis and around the side wall surface. Has the highest height and is V-shaped. This phenomenon tends to be more pronounced in high-speed rotation stirring than in low-speed rotation stirring, and the higher the rotation speed, the greater the difference in height between the central portion and the outer peripheral portion. On the other hand, when the direction of the circulating flow due to the stirring is close to the same direction as the stirring shaft and the side wall surface (hereinafter referred to as the vertical direction), the reaction liquid surface in the tank has a central portion around the stirring axis and an outer peripheral portion around the side wall surface. The difference in height is reduced, and furthermore, it is hardly affected by the low-speed rotation stirring and the high-speed rotation stirring. As a result of examining the relationship between the surface state of the reaction liquid and the esterification reactivity of dicarboxylic acid and diol with the direction of the circulation flow of this stirring, the height of the circulation flow in the vertical direction was higher than that of the reaction liquid surface with a large difference in the horizontal direction. It was found that the reaction liquid surface with a smaller difference was excellent in shortening the reaction time and suppressing side reactions, and could improve the esterification reactivity. The reason for this is that, in the case of a reaction liquid surface having a small height difference, there is no (1) gas phase part (space part) in the center of the reaction liquid surface, so that the reaction liquid phase part (2) a uniform solid-liquid slurry reaction system due to good circulation between the bottom and top of the tank; (3) a reaction to be quickly distilled out of the tank It is conceivable that the generated water is pushed up from the bottom to the top and does not stay.

[0012] As a configuration of a stirring reaction tank for producing a reaction liquid surface with a small difference in elevation by making the circulating flow by stirring a vertical direction, a stirring shaft that can be rotated from outside the tank is installed in the center of the tank, and the shaft is attached to the shaft. A bottom paddle having a lower end disposed close to the bottom of the tank, a lattice wing comprising an arm portion and a strip extending perpendicularly from the arm portion above the bottom paddle portion, or located vertically. Attaching a stirring blade having a plurality of flat plate blades whose plane directions cross each other, and fixing a plurality of baffles (baffles) along the rotation axis direction from the lower part to the upper part on the inner wall surface of the tank at intervals This is characterized by being a stirred reaction tank.

As a specific stirring reaction tank used in the present invention, a stirring tank equipped with a lattice blade having a bottom paddle on a stirring shaft is described in Japanese Patent Application Laid-Open No. 61-200842, Sumitomo Heavy Industries, Ltd. The "Max Blend" manufactured by Shinko Pantec Co., Ltd. is preferable for the one equipped with a plurality of flat blades located vertically on the stirring shaft and intersecting the plane directions with each other.

FIG. 1 shows an example of a stirring reaction tank corresponding to the above-mentioned "Max Blend" applicable to the present invention. FIG. 1 (a) is a side sectional view, and FIG. 1 (b) is an AA sectional view. FIG. The stirring reaction tank 1 has a stirring shaft 2 rotatable from the outside as a center, and the stirring shaft 2 is provided with a stirring blade 3 having a bottom paddle 3a and a lattice blade 3b at a lower end portion. , Four baffle plates 4 along the rotation axis direction from the lower part to the upper part are fixed at intervals.

FIG. 2 shows an example of a stirred reaction tank corresponding to the above “full zone” applicable to the present invention.
(A) is a side sectional explanatory view, and (b) is an AA sectional explanatory view. This stirring reaction tank 1 has a stirring shaft 2 rotatable from outside.
The agitating shaft 2 is provided with a stirring blade 3 having two flat plate blades which are located vertically and intersect with each other in a plane direction. Are fixed at intervals.

FIGS. 3 and 4 show examples of conventional reaction stirring tanks which are not suitable for the present invention. FIG. 3 corresponds to a turbine type stirring tank, and FIG. 4 corresponds to a helical ribbon type stirring tank. is there.

Next, in the esterification reaction of the present invention, when stirring is performed at a peripheral speed of the stirring blade of 0.5 m / sec or more, preferably 0.7 m / sec or more in the tank during the reaction,
The reaction is performed under the condition that the height difference of the reaction liquid surface in the tank is 1/4 or less, preferably 1/5 or less of the diameter in the tank. This makes it possible to improve the reactivity of the esterification reaction in the production of polyesters and their copolymers, which could not be achieved by the method using only reaction conditions.

The peripheral speed (m / sec) of the stirring blade described above
Is a value obtained from a relational expression of the outer circumference of the stirring blade (the outer diameter of the stirring blade × π (m)) × the rotation speed of the stirring blade (rpm) ÷ 60. If the peripheral speed of the stirring blade is 0.5 m / sec or less, the stirring effect becomes insufficient, and the temperature in the reaction system and the slurry property of solid-liquid become non-uniform, so that the reactivity decreases. The upper limit of the peripheral speed of the stirring blade is determined by the outer diameter of the stirring blade and the number of rotations, which are related to the volume and shape of the reaction tank, but as a guide, the resistance load applied to the stirring blade increases and the stirring blade itself deforms. The optimal level is such that stable operation of the stirring reaction tank can be maintained without causing problems such as occurrence of abnormalities in the stirring shaft and its peripheral devices. In order to determine the height difference between the reaction liquid surfaces described above, an ordinary method such as checking with a liquid level meter or a scale previously attached to the inner wall surface of the tank and the stirring shaft is used. If the height difference of the reaction liquid surface in the tank is 1/4 or more of the inner diameter of the tank, the esterification reactivity becomes unstable and poor, and the object of the present invention cannot be achieved. Further, the liquid level in the reaction tank becomes too high, and the adhered liquid splatters increase in the gas phase on the inner wall in the upper part of the tank, which results in the generation of colored foreign matters thermally degraded.

The aromatic dicarboxylic acid of the present invention includes terephthalic acid, isophthalic acid, phthalic acid, naphthalene-2,6
-Dicarboxylic acid, naphthalene-2,7-dicarboxylic acid,
Diphenyl-4,4'-dicarboxylic acid, diphenoxyethanedicarboxylic acid, 5-sulfoisophthalic acid and the like. Of these, terephthalic acid and isophthalic acid are particularly preferably used. Terephthalic acid alone, terephthalic acid and isophthalic acid are mixed, or terephthalic acid and one or more aromatic dicarboxylic acids are mixed. Used as

As another dicarboxylic acid component, an aliphatic dicarboxylic acid can be used in combination with an aromatic dicarboxylic acid. Aliphatic dicarboxylic acids are C2-C36 aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic acid, fumaric acid,
Examples thereof include dimer acid and 1,4-cyclohexanedicarboxylic acid, and in particular, dodecanedicarboxylic acid and dimer acid are preferably used. These are used singly or as a mixture of one or more other aliphatic dicarboxylic acids and used in combination with an aromatic dicarboxylic acid. At this time, the amount of the aliphatic dicarboxylic acid added can be up to 40 mol% based on the total acid content.
An addition amount of 40 mol% or more is not preferred because the range of decrease in polymer melting point becomes large and practical performances such as moldability and heat resistance deteriorate.

As the diol component, 1,4-butanediol is mainly used, and other diols include, for example, ethylene glycol, propylene glycol, pentamethylene glycol, 1,6-hexanediol, neopentyl glycol and the like. Aliphatic diols, 1,4-
Alicyclic diols such as cyclohexane dimethanol and tricyclodecane dimethylol are exemplified, and propylene glycol and 1,4-cyclohexane dimethanol are particularly preferably used. These can be used in a mixture of 1,4-butanediol and one or more kinds, and can be used in an amount of 30 mol% or less of all diol components.

In producing the polyetherester block copolymer, the number average molecular weight is from 600 to 40.
A polyalkylene ether glycol of 00 is used. The polyalkylene ether glycol is an aliphatic polyether, for example, poly (ethylene oxide) glycol, poly (propylene oxide) glycol, poly (tetramethylene oxide) glycol, poly (hexamethylene oxide) glycol, ethylene oxide and propylene oxide. Copolymers, ethylene oxide addition polymers of poly (propylene oxide) glycol, copolymers of ethylene oxide and tetrahydrofuran, and the like. In particular, poly (tetramethylene oxide) glycol, poly (propylene) Ethylene oxide adducts of (oxide) glycols are preferred. These can be used alone or as a mixture of one or more other aliphatic polyethers. Their molecular weight ranges from 600 to 4000, preferably from 800 to 3000.
If it is less than 600, the properties of the elastomer such as elasticity will be insufficient, and if it is more than 4000, the compatibility of the polymer will deteriorate and a high-performance elastomer cannot be obtained. The addition amount of these polyalkylene ether glycols is an upper limit of 90% by weight based on the whole polymer, and is preferably an upper limit of 85% by weight from the viewpoint of the balance between physical properties as a resin and moldability. If it exceeds 90% by weight, physical properties such as durability and heat resistance as an elastomer resin are reduced,
Moldability also becomes poor.

The polyalkylene ether glycol may be added in whole or in part before or during the start of the esterification reaction, and the whole or the remainder other than the one added in the esterification reaction is substantially terminated. You may add after doing.

Examples of the organotitanium compound to be present at the time of the esterification reaction of the present invention include (R ₁ O) nTi (OR ₂ ) _4-n (where R ₁ and R ₂ are an aliphatic group having 1 to 10 carbon atoms). , An alicyclic or aromatic hydrocarbon group, and n is a titanate ester and a condensate represented by a number from 0 to 4 (including a decimal number).

Specifically, methyl ester of titanic acid,
Tetra-n-propyl ester, tetra-n-butyl ester, tetraisopropyl ester, tetraisobutyl ester, tetra-tert-butyl ester, cyclohexyl ester, phenyl ester, benzyl ester,
There are a tolyl ester and a mixed ester thereof. Among these, tetra-n-propyl ester, tetra-n-butyl ester and tetraisopropyl ester are preferred, and tetra-n-butyl ester is particularly preferred. These organic titanium compounds are
One type may be used, or two or more types may be used in combination.

The amount of the organic titanium compound added is usually
It is about 0.005 to 0.3% by weight based on the amount of the produced polymer.

The organic titanium compound may be added at once or in portions before the esterification reaction. If necessary, a catalyst for the polycondensation reaction may be added after the end of the esterification reaction and before the polycondensation reaction. Can also.

In the present invention, in order to further increase the esterification reactivity and further suppress the by-product of THF,
Organotin compounds such as monoalkyltin compounds, monoaryltin compounds, dialkyltin compounds, diaryltin compounds, trialkyltin compounds, triaryltin compounds, and tetraalkyltin compounds can also be added in combination with the organic titanium compounds. Of these, monoalkyltin compounds are particularly preferred. The addition amount of these organotin compounds is usually 0.0
It is about 0.5 to 0.1% by weight.

The esterification reaction and the polycondensation reaction in the present invention may be performed in either a batch system or a continuous system. In the case of a continuous system, the reaction vessel of the present invention is applied to part or all of the steps until the esterification reaction is substantially completed.

In the esterification reaction, a diol containing 1,4-butanediol as a main component is added in excess of all dicarboxylic acids. 1.2 ~
2.2 is preferable, and in the production of the polyetherester block copolymer, 1.4 to 2.2 is preferable.
In particular, 1.6 to 1.9 is preferable. The glycol containing 1,4-butanediol as a main component can be added at the start of the esterification reaction or in the esterification first tank at a time in the continuous method at the above-mentioned molar ratio. Glycol can be added at the start of the reaction or in the first esterification tank, and the remainder can be added during the esterification reaction (in the continuous method, to the reaction tanks after the second esterification tank).

Further, the esterification reaction temperature is 190-2.
40 ° C is preferable, and more preferably 195 to 235 ° C. The reaction is carried out at normal pressure or reduced pressure, and a pressure reduction level of 940 × 10 ^{2 to} 400 × 10 ² Pa, preferably 870 × 10 ^{2 to} 470 × 10 ² Pa is applied.

[0032]

The present invention will be specifically described below with reference to examples.

In this example, parts means parts by weight, the conversion of the esterification reaction product, the solution haze, the amount of by-product tetrahydrofuran (THF), and the melting of the final polymer obtained by the polycondensation reaction. The viscosity (MFR), solution haze, carboxyl end group content and melting point were determined by the following methods. [Reaction rate of esterification reaction product] Reaction rate (%) = [(saponification value−acid value) / saponification value] × 1
00 Saponification value: value obtained by subjecting the product to alkaline hydrolysis and back titrating with an acid.

Acid value: The value obtained by dissolving the product in an O-cresol / chloroform solvent and titrating with ethanolic potassium hydroxide. [Amount of THF by-produced in the esterification reaction] Gas chromatograph quantitative analysis value of the distillate of the esterification reaction. [Solution haze] 5.4 g of a sample was dissolved by heating in 40 ml of a mixed solvent of phenol / ethane tetrachloride (60/40 wt%), and this solution was placed in a 20 mm cell and measured directly by a haze computer (Suga Test Machine HGM-30DP). Value. [Polymer Melt Viscosity (MFR)] Measured at a predetermined temperature under a load of 2160 g in accordance with ASTM D1238. [Amount of carboxyl terminal group of polymer] A sample (1.5 g) was dissolved by heating in a mixed solvent of O-cresol / chloroform (50 ml) and titrated with an N / 25 ethanolic sodium hydroxide solution. [Polymer Melting Point] Using a differential scanning calorimeter (DSC-910, manufactured by Du Pont) under a nitrogen gas atmosphere at 10 ° C.
The top temperature of the melting peak when heated at a heating rate of / min was measured. <Example 1> 149 parts of terephthalic acid, 145 parts of 1,4-butanediol (1.8 mole ratio to terephthalic acid) and 110 parts of polytetramethylene oxide glycol having a number average molecular weight of about 1400 were added to 0.1 parts of tetrabutyl titanate. 12 parts, butylhydroxytin oxide 0.09
Along with the parts, the mixture was charged into a reaction tank of a “Max Blend” stirring blade manufactured by Sumitomo Heavy Industries, Ltd. described in Table 1, and while the temperature was gradually raised from 160 to 230 ° C., the reaction product distillate was passed through a rectification column to outside the system. To carry out an esterification reaction. Table 1 shows the time required from the start of the esterification reaction to the end of the reaction, the conversion of the esterification reaction product, the solution haze, and the amount of by-product THF in the distillate.

Next, the esterification reaction product was transferred to a polycondensation reaction tank, and 0.66 parts of tetrabutyl titanate and 0.36 of "Irganox" 1098 (a hindered antioxidant manufactured by Ciba Geigy) were added. After the addition, the pressure in the system was gradually reduced from normal pressure to 66.5 Pa or less over 60 minutes while increasing the temperature to 245 ° C. After performing the polycondensation reaction for 4 hours after starting the temperature rise and pressure reduction, the resulting molten polymer is discharged in a strand form with water cooling,
After cutting with a cutter, pellets were obtained. Table 1 shows the quality evaluation results of the obtained polymer pellets. <Example 2> The polycondensation reaction was carried out under the same conditions as in Example 1 except that the esterification reaction was carried out in a reaction tank having a "full zone" stirring blade manufactured by Shinko Pantech described in Table 1.
Were obtained. <Comparative Examples 1 and 2> A polycondensation reaction was carried out under the same conditions as in Example 1 except that the esterification reaction was carried out in a reactor equipped with a helical ribbon type or turbine type stirring blade described in Table 1. The results shown in Table 1 were obtained. <Comparative Example 3> In Example 1, the stirring speed of the reaction tank of the “Max Blend” stirring blade manufactured by Sumitomo Heavy Industries, Ltd. was set to 5
Except that the esterification reaction (difference in liquid level: about 1 cm) was carried out under the condition that the stirring peripheral speed was reduced to 8 rpm and the stirring peripheral speed was 0.3 m / sec, the reaction was carried out under the same conditions as in Example 1, and the results shown in Table 1 were obtained. . Example 3 90 parts of terephthalic acid and 93 parts of 1,4-butanediol (1.9 mol ratio to terephthalic acid) were added together with 0.06 part of tetrabutyl titanate while replenishing a slurry-like liquid, A first esterification reaction tank equipped with a “Max Blend” stirring blade manufactured by Sumitomo Heavy Industries, Ltd. described in Table 2 (tank temperature 210 ° C., tank depressurization 800 ×
(Maintained at 10 ² Pa), and the reaction product distillate was distilled out of the system through a rectification column to proceed the reaction. Next, the product of the first esterification reaction tank was withdrawn, and a second esterification reaction tank equipped with a “Max Blend” stirring blade under the same conditions as the first esterification reaction tank (tank temperature: 225 ° C.,
The pressure in the tank was maintained at 600 × 10 ² Pa), and the reaction distillate was distilled out of the system through a rectification column to proceed the reaction. The supply rate of the slurry raw material and the extraction of the esterification product so that the liquid volume in the first esterification reaction tank and the second esterification reaction tank is 2.5 L and the liquid retention in the tank is 2 hours 30 minutes. The continuous esterification reaction step was in a steady state 18 hours after the supply of the slurry raw material was started while controlling the speed. The product in the second esterification reaction tank is continuously extracted and supplied to the next preliminary polycondensation reaction tank, and a part is sampled, cooled and solidified, and then crushed into fine particles. And Table 2 shows the measurement results of the reaction rate and solution haze of this sample, and the amount of by-produced THF in the distillate.
Shown in

Next, 189 parts of polytetramethylene oxide glycol having a number average molecular weight of about 2,000, 0.9 parts of tetrabutyl titanate and "Irganox" 1098
(Hindered phenol-based antioxidant manufactured by Ciba Geigy) While replenishing 0.45 parts of the mixed solution, together with the product extracted from the second esterification reaction tank, the inside temperature of the tank was set to 24.
The reaction was proceeded by continuously supplying to a preliminary polycondensation reaction tank maintained at 0 ° C. and a pressure reduction degree of 20 × 10 ² Pa in the tank. Further, the prepolymer withdrawn from the pre-polycondensation reaction tank was cooled to a temperature in the tank of 2%.
The molten polymer was continuously supplied to a final polycondensation reaction tank maintained at 50 ° C. and a degree of pressure reduction of 2 × 10 ² Pa or less in the tank to advance the reaction, and then continuously withdrawn in a strand form from the final polycondensation reaction tank. After cooling with water and cutting with a cutter,
Pellets were used. The supply rates of the esterification reaction product and the polytetramethylene oxide glycol raw material and the molten polymer were adjusted so that the liquid volume in the pre-polycondensation reaction tank and the final polycondensation reaction tank was 5 L, and the liquid retention in the tank was 2 hours. 16 hours after the start of the supply of the product of the second esterification reaction tank to the preliminary polycondensation reaction tank while controlling the extraction speed, all the steps of the continuous polycondensation reaction reached a steady state, and the quality shown in Table 2 was obtained. The final polymer was obtained. <Comparative Example 4> The esterification reaction to the final weight were performed under the same conditions as in Example 3 except that the esterification reaction was performed in the first and second reaction tanks provided with the helical ribbon type stirring blades described in Table 2. The procedure was continued until all the steps of the continuous reaction up to the condensation reaction reached a steady state, and the results shown in Table 2 were obtained. <Example 4> 148 parts of terephthalic acid, 136 parts of 1,4-butanediol (1.7 mole ratio to terephthalic acid)
While replenishing a mixture of a slurry liquid uniformly prepared with 0.1 part of tetrabutyl titanate and 0.08 part of butylhydroxytin oxide, and 60 parts of polytetramethylene oxide glycol having a number average molecular weight of about 1000, Continuous supply to the first esterification reaction tank equipped with a “Max Blend” stirring blade manufactured by Sumitomo Heavy Industries, Ltd. (holding at a tank temperature of 210 ° C. and a decompression degree of 800 × 10 ² Pa in the tank) shown in Table 2. Then, the reaction product distillate was distilled out of the system through a rectification column to proceed the reaction. Next, the product of the first esterification reaction tank was extracted, and a second esterification reaction tank equipped with a “Max Blend” stirring blade under the same conditions as the first esterification reaction tank (tank temperature: 225 ° C., depressurization in the tank) Degree 600
(Maintained at × 10 ² Pa), and the reaction product distillate was distilled out of the system through a rectification column to proceed the reaction. The supply rate of the slurry raw material and the extraction rate of the esterification product were adjusted so that the amount of the liquid in the first esterification reaction tank and the second esterification reaction tank was 4 L, and the liquid stayed in the tank was 2 hours. Meanwhile, the continuous esterification reaction step was in a steady state 18 hours after the supply of the slurry raw material was started. The product in the second esterification reaction tank is continuously withdrawn and supplied to the next pre-polycondensation reaction tank, and a part of the sample is sampled, cooled and solidified, and crushed into fine particles. And Table 2 shows the measurement results of the reaction rate and solution haze of this sample, and the amount of by-product THF in the distillate.

Next, tetrabutyl titanate 0.43
Parts, "Irganox" 1098 (Hindered phenol-based antioxidant manufactured by Ciba Geigy) 0.3 part and 1,
While replenishing a mixture of 8 parts of 4-butanediol,
Along with the product extracted from the esterification reaction tank, the reaction was continuously fed to a pre-polycondensation reaction tank maintained at a tank temperature of 240 ° C. and a reduced pressure of 20 × 10 ² Pa in the tank. Furthermore, the prepolymer extracted from the preliminary polycondensation reaction tank is
The reaction is advanced by continuously supplying to the final polycondensation reaction tank maintained at a temperature in the tank of 250 ° C. and a degree of vacuum of 2 × 10 ² Pa or less, and then continuously withdrawn in a strand form from the final polycondensation reaction tank. The melted polymer was solidified by water cooling, cut with a cutter, and then pelletized. While adjusting the supply rate of the esterification reaction product and the withdrawal rate of the molten polymer such that the volume of the liquid in the pre-polycondensation reaction tank and the final polycondensation reaction tank is 4 L and the liquid retention in the tank is 2 hours, Sixteen hours after the start of the supply of the product of the second esterification reaction tank to the preliminary polycondensation reaction tank, all the steps of the continuous polycondensation reaction reached a steady state, and a polymer having the quality shown in Table 2 was obtained. <Example 5> According to the conditions of Example 4, except that the esterification reaction was performed in a first reaction tank and a second reaction tank equipped with a "full zone" stirring blade manufactured by Shinko Pantech listed in Table 2. The reaction was performed until all the continuous reaction steps from the esterification reaction to the final polycondensation reaction reached a steady state, and the results shown in Table 2 were obtained. <Comparative Example 5> In Example 5, the stirring speed of the first esterification reaction tank and the second esterification reaction tank equipped with a “full zone” stirring blade manufactured by Shinko Pantech Co., Ltd. was reduced to 75 rpm, and the stirring peripheral speed was set to 0. All the continuous reaction steps from the esterification reaction to the final polycondensation reaction were in a steady state under the same conditions as in Example 5 except that the reaction was performed under the condition of 0.4 m / sec (difference in liquid level: about 1.5 cm). The operation was performed until the results were obtained, and the results shown in Table 2 were obtained. <Comparative Example 6> The esterification reaction was carried out under the same conditions as in Example 4 except that the esterification reaction was carried out in the first reaction tank and the second reaction tank equipped with the turbine type stirring blades described in Table 2. The procedure was continued until all the steps of the continuous reaction up to the polycondensation reaction reached a steady state, and the results shown in Table 2 were obtained.

[0038]

[Table 1]

[0039]

[Table 2]

[0040]

As described above, the production method of the present invention can increase the reactivity of the subsequent polycondensation reaction because the esterification reaction of the polyester direct polymerization method can be made highly reactive, and as a result, high quality A polyester or a copolymer thereof can be advantageously obtained. The reactivity improving effect of the present invention is particularly large in a polyetherester block copolymer, and is particularly advantageous for producing the copolymer.

[Brief description of the drawings]

FIG. 1 is a side sectional view (a) of a stirring reaction tank according to the present invention and an AA section view (b) thereof.

FIG. 2 is a side sectional view (a) of another stirring reaction tank according to the present invention and an AA section view (b) thereof.

FIG. 3A is a side sectional view of a conventional stirring reaction tank, and FIG.

FIG. 4 is a side sectional view (a) of another conventional stirring reaction tank and an AA section view (b) thereof.

[Explanation of symbols]

 Reference Signs List 1 reaction tank 2 stirring shaft 3 stirring blade 4 baffle plate

Continuation of the front page (72) Inventor Mamoru Horiuchi 194-1, Kita-ku, Hoshi-Hoshizaki-cho, Minato-ku, Nagoya-shi, Aichi F-term (reference) 4J029 AA03 AB04 AB07 AC01 AC02 BA05 BF25 CB04A CB05A CB05B CB06A CB10A CC05A CC06A CF15 CH02 HA01 HB01 JB131 JC751 JF321 JF371 KB02 KB05 KE03 KJ05 KJ06 KJ08 LA04 LA05

Claims (3)

[Claims] 1. A dicarboxylic acid having an aromatic dicarboxylic acid as a main component and a diol having a 1,4-butanediol as a main component, and a polyalkylene having a number average molecular weight of 600 to 4000 by 0 to 90% by weight based on the whole polymer. When an esterification reaction is carried out with ether glycol in the presence of an organic titanium compound and then a polycondensation reaction is carried out to produce a polyester or a copolymer thereof, the esterification reaction is carried out at a peripheral speed of 0.5 m / A method for producing a polyester or a copolymer thereof, wherein the method is carried out under conditions where the difference in height of the reaction liquid in the tank is not more than 1/4 of the diameter in the tank. 2. A stirrer shaft rotatable from outside the tank is installed at the center of the tank, and a plurality of lattice wings having a bottom paddle at the lower end or a plurality of vertically arranged crosswise planes intersecting each other are provided on the shaft. Esterification reaction is carried out using a stirring reaction tank equipped with stirring blades having flat blades and fixed on the inner wall surface of the tank from the bottom to the top with multiple baffles along the rotation axis at intervals. The method for producing a polyester or a copolymer thereof according to claim 1, wherein 3. The method according to claim 1, wherein the esterification reaction is carried out in the presence of an organic titanium compound and an organic tin compound, and the molar ratio of the diol to the dicarboxylic acid is in the range of 1.2 to 2.2. 3. The method for producing the polyester or the copolymer thereof according to item 2.