JP2006188576A - Method for producing polyester - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a continuous method for producing a polyester which increases the productivity of the polyester while reducing the quality variation with time such as intrinsic viscosity, color and diethylene glycol content. <P>SOLUTION: The continuous method for producing the polyester comprises subjecting an aromatic dicarboxylic acid or a derivative thereof and a diol compound to esterification reaction in a reactor provided with an esterification reactor and a rectifying column to form a polyester precursor and then subjecting the polyester precursor to polycondensation under vacuum, wherein the molar ratio of the diol compound to the aromatic dicarboxylic acid or a derivative thereof to be subjected to esterification reaction (diol compound/aromatic dicarboxylic acid or a derivative thereof) is adjusted to 1.15 or more; a specified amount of the component containing the diol compound which is distilled to the rectifying column is continuously removed from the esterification reactor; and the remaining part of the component containing the diol compound which is distilled to the rectifying column is returned to the esterification reactor. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for continuously producing polyester, and more particularly to stabilization of an esterification process and stabilization of polyester quality.

  Polyester, especially polyethylene terephthalate, has excellent physical and chemical properties, so it can be used for various molded products such as industrial fibers such as clothing and tire cords, films and engineering plastics, and beverages and detergents. Widely used as a filling container.

  In general, a direct polymerization method or a transesterification method is used as a method for producing the polyester used in such various applications. In recent years, direct polymerization has become the mainstream production method because of the availability of raw materials. In the past, the polymerization of polyesters was often performed by a batch polymerization method. However, in recent years, in order to produce polyesters at a low cost, switching to a continuous polymerization method has been promoted by utilizing the merit of scale.

  In order to further improve the productivity, there have been reports on improvement of the continuous polymerization method (for example, see Patent Documents 1 and 2). Moreover, the report regarding the continuous polymerization method which keeps the quality of polyester favorable, improving productivity is made (for example, refer patent documents 3-7). However, although it is possible to increase productivity by these methods, it is impossible to reduce the variation in the quality of the polyester polymer over time, and it solves all the main problems in the production process of the polyester polymer. Has not reached.

Japanese Examined Patent Publication No. 3-14052 JP 2004-2901 A JP 2001-172378 A Japanese Patent Laid-Open No. 10-279777 Japanese Patent Laid-Open No. 11-279834 JP-A-9-124784 Japanese Patent Publication No.59-48058

  It is to reduce the time-dependent variation in quality such as intrinsic viscosity, color tone and diethylene glycol content of the polyester while increasing the productivity of the polyester.

  As a result of intensive studies to collectively solve the problems of the conventional methods as described above, the recovery process including the rectification process in which the distillate glycol generated from each process is not necessarily installed is not necessarily passed through. The present invention was completed by studying a method for producing a polyester having a stable quality while keeping the components of the reaction raw material constant while directly forming the raw material.

  That is, the present invention “forms a polyester precursor by subjecting an aromatic dicarboxylic acid or an ester-forming derivative thereof and a diol compound to an esterification reaction in an esterification reactor equipped with an esterification reactor and a rectifying column. In the method of continuously producing polyester by polycondensation of the polyester precursor under reduced pressure, the molar ratio of diol compound to be subjected to esterification reaction and aromatic dicarboxylic acid or ester-forming derivative thereof (diol compound / Aromatic dicarboxylic acid or ester-forming derivative thereof) is 1.15 or more, and diol is selected from the group consisting of water distilled into a rectifying column, aromatic dicarboxylic acid or ester-forming derivative thereof, diol compound and polyester precursor. A certain amount of components including compounds are continuously removed from the esterification reactor. The component containing the diol compound is returned to the esterification reactor from the group consisting of the remaining water distilled into the rectification column, aromatic dicarboxylic acid or its ester-forming derivative, diol compound and polyester precursor. A continuous production method for polyester.

  By carrying out the present invention, when polyester is produced by a continuous polymerization method, it is possible to reduce the variation with time in quality while improving productivity.

  In the continuous production method of the polyester of the present invention, the polyester is a polyester obtained by reacting an aromatic dicarboxylic acid or an ester-forming derivative thereof and a diol compound, preferably polyethylene terephthalate, polytrimethylene terephthalate and polybutylene terephthalate. is there. Accordingly, it is preferable to use terephthalic acid or a lower aliphatic ester, a lower aromatic ester, an acid halogenated compound, an acid anhydride, or the like as the aromatic dicarboxylic acid or an ester-forming derivative thereof. More preferred is a methyl ester or phenyl ester, and still more preferred is a methyl ester. As the diol compound, glycols such as ethylene glycol, trimethylene glycol or tetramethylene glycol are preferably selected. Preferably, the aromatic dicarboxylic acid or its ester-forming derivative is terephthalic acid, and the diol compound is ethylene glycol.

  Here, a part of the aromatic dicarboxylic acid or its ester-forming derivative is, for example, 5-sodium sulfoisophthalic acid, 5-potassium sulfoisophthalic acid, p-β-hydroxyethoxybenzoic acid, p-hydroxybenzoic acid, isophthalic acid, 4,4′-diphenylsulfone dicarboxylic acid, 4,4′-diphenyldicarboxylic acid, 1,2-diphenoxyethane-p, p′-dicarboxylic acid, 2,6-naphthalenedicarboxylic acid, adipic acid or sebacic acid, etc. Replace with a bifunctional carboxylic acid or an ester-forming derivative thereof, or part of the diol compound is hexamethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,4-bi -β- hydroxyethoxy benzene, or aliphatic such as bisphenol A, may be a copolymer polyester is replaced with the dihydroxy compound or an ester-forming derivative of the alicyclic or aromatic.

  Further, the polyester of the present invention is obtained by subjecting an aromatic dicarboxylic acid or an ester-forming derivative thereof and a diol compound to an esterification reaction in an esterification reaction apparatus provided with an esterification reactor and a rectifying tower. The polyester precursor is then produced by a continuous production process in which the polyester precursor is polycondensed under reduced pressure. Hereinafter, the continuous production method of the present invention will be described with reference to the drawings. Hereinafter, terephthalic acid is used as the aromatic dicarboxylic acid or its ester-forming derivative, and ethylene glycol is used as the diol compound. However, according to the following description, the present invention is limited to terephthalic acid and ethylene glycol.・ Reaction conditions such as pressure are not limited as described.

  FIG. 1 is a conceptual diagram illustrating the present invention. In FIG. 1, ethylene glycol, which is a combination of terephthalic acid 1, ethylene glycol 2 and ethylene glycol from distilled ethylene glycol storage tank 6, is supplied to a slurry mixer 3 with a constant ethylene glycol / terephthalic acid molar ratio. Stir and mix to make a slurry. This slurry is sent to the esterification reactor. In the esterification reactor A 4-1, the esterification reaction is carried out under the conditions of 240 to 295 ° C. with stirring and normal pressure to 0.5 MPa. Water and polyester precursor 20-2 are produced by the esterification reaction. Of these water, terephthalic acid, ethylene glycol, and polyester precursor, the low boiling point component is distilled into the rectifying column A5-1. Usually, water is separated from the top of the column, and conditions are set so that ethylene glycol can be recovered from the lower part of the rectification column. As a result, a component containing ethylene glycol from the group consisting of water, terephthalic acid, ethylene glycol, and a polyester precursor is distilled from the ester reactor to the rectification column. The water produced by the esterification reaction in the esterification reactor A4-1 is separated as distilled water from the top of the rectification column A5-1 to the outside of the esterification reaction apparatus. Ethylene glycol is separated from the lower part of the rectifying column A5-1 as a bottoms, and a predetermined amount set in advance as distilled ethylene glycol A18-1 is distilled from the esterification reactor (rectifying column A). A fixed amount is continuously taken out to the storage tank 6, and the remainder is returned to the esterification reactor A4-1 (recovered ethylene glycol A19-1). In the esterification reactor A 4-1, the polyester low polymer (polyester precursor) 20-2 almost completed in the esterification reaction is sent to the polycondensation reactor in the next step. The polyester precursor preferably has a degree of polymerization of 2 to 10 from the viewpoint of productivity and the quality of the obtained polyester. A more preferable polymerization degree range is 4-8. Setting the degree of polymerization of the polyester precursor to 2 to 10 can be achieved by controlling the amount of ethylene glycol taken from the rectifying column to be a constant amount.

At this time, it is preferable that the amount W per unit time for taking out the ethylene glycol from the rectifying column provided in the esterification reactor to the outside of the esterification reactor is set so as to satisfy the following formula (1).
W ≦ W1- (Dp + 1) / Dp × (W2 / M2) × M1 (1)
[In the above formula, the amount of diol compound supplied to the esterification reactor per unit time is W1, the molecular weight is M1, the amount of aromatic dicarboxylic acid supplied to the esterification reactor per unit time is W2, and the molecular weight is M2. The polymerization degree of the polyester precursor is Dp. ]
More preferably,
W1-2 × (W2 / M2) × M1 <W
<= W1- (Dp + 1) / Dp * (W2 / M2) * M1 (2)
Set to be.
When the range of these mathematical formulas is satisfied, the degree of polymerization of the polyester precursor can be controlled, so that variations in physical properties such as intrinsic viscosity, color tone, diethylene glycol amount and the like in the obtained polyester are preferable. On the other hand, if the range of this numerical formula is not satisfied, the degree of polymerization increases greatly, and the variation in quality increases. As described above, it is necessary to control the amount of ethylene glycol taken out in advance so as to satisfy this mathematical expression.

  In the polycondensation reactors 7, 8, and 9, the polyester polymer (polyethylene terephthalate 17) is produced by performing the reaction in the temperature and pressure ranges of 250 to 300 ° C. and 0.05 to 60 kPa. These polycondensation reactors are provided with wet condensers 10, 11, and 12, respectively, and the distilled ethylene glycol generated by the polycondensation reaction is condensed here, and is stored in circulating ethylene glycol storage tanks 13, 14, and 15, respectively. While being stored, it is sent to the wet condensers 10, 11, and 12 again as circulating ethylene glycol, and used as a spray liquid for condensing the distilled ethylene glycol from the polycondensation reactor.

  Each wet condenser is preferably connected to a vacuum source by piping. In particular, a high degree of vacuum is required in the late polycondensation reactor 9. Each of the pressure loss resulting from the vapor pressure of low boiling point components such as water contained in the distilled ethylene glycol in the wet condenser 12 attached to the polycondensation reactor 9, and the polyester low polymer generated by entrainment For the purpose of preventing adhesion to the reactor (apparatus) and piping, circulating ethylene glycol 16 is less than the amount equal to ethylene glycol equal to the amount of components in the product polyester and the water content is less than 0.5%. It is also preferable to add to the storage tank 15.

  In the circulating ethylene glycol storage tank 15, the liquid in the storage tank is extracted so that the liquid level is constant. The extracted liquid is sent to the circulating ethylene glycol storage tank 14. Here, the extracted liquid is used as a spray liquid of the wet condenser 11 together with the distilled ethylene glycol generated in the polycondensation reactor 8. Thereafter, the liquid in the storage tank is withdrawn so that the liquid level of the circulating ethylene glycol storage tank 14 is constant, and sent to the circulating ethylene glycol storage tank 13. Then, it is used as the spray liquid of the wet condenser 10 together with the distilled ethylene glycol generated in the polycondensation reactor 7. Thereafter, the liquid in the storage tank is drawn out so that the liquid level in the circulating ethylene glycol storage tank 13 is constant, and sent to the distilled ethylene glycol storage tank 6.

  Here, if the circulating ethylene glycol storage tanks 13 and 14 corresponding to the wet condensers 10 and 11 are unified into one tank of the circulating ethylene glycol storage tank 13, the above operation is performed only once. When there are four or more polycondensation reactors, the above operation is repeated. Further, the present invention mainly relates to an esterification reaction, particularly a rectification column installed in the esterification reaction apparatus, and therefore the polycondensation reactor is not limited to the illustrated one. For example, the polycondensation reactors disclosed in Japanese Patent Application Laid-Open Nos. 2004-2901, 2001-40080, 2000-136247, 2000-239368, 10-95843, etc. There is no problem even if it is replaced. Moreover, there is no problem even if a vertical type complete mixing tank type polycondenser or a horizontal polycondenser which is usually used is used.

  Distilled ethylene glycol collected in the ethylene glycol storage tank 6 is supplied to the slurry mixer 3 together with terephthalic acid 1. At this time, the molar ratio of ethylene glycol and terephthalic acid is controlled to be always constant. This control system may proportionally control terephthalic acid based on ethylene glycol, or may proportionally control ethylene glycol based on terephthalic acid. In order to keep the production amount of the product polyester as constant as possible, it is preferable to keep the molar ratio constant by proportionally controlling ethylene glycol based on the supply amount of terephthalic acid. In the present invention, the molar ratio of the diol compound to be subjected to the transesterification reaction and the aromatic dicarboxylic acid or ester-forming derivative thereof (diol compound / aromatic dicarboxylic acid or ester-forming derivative) needs to be 1.15 or more. It is. More preferably, the molar ratio is 1.35 or more. If it is less than 1.15, a good slurry cannot be obtained. Further, when this ratio is 1.15 or more, a good slurry can be obtained and the esterification (exchange) reaction is stabilized, so that variations in physical properties such as intrinsic viscosity, color tone, diethylene glycol amount, etc. of the obtained polyester are reduced. preferable. In order to keep this ratio at 1.15 or more, a method of proportionally controlling ethylene glycol based on the supply amount of terephthalic acid supplied to the slurry mixer 3 as described above is usually employed. Distilled ethylene glycol from the distillate ethylene glycol storage tank 6 may contain large foreign substances and polymer denatured products. Therefore, a filter is provided between the distillate ethylene glycol tank 6 and the slurry mixer 3 to remove these. It is preferable to install. In addition, it is desirable to install another ethylene glycol supply line 2 in the slurry mixer 3 for emergency use. In addition, it is easy to install an ethylene glycol storage tank as a buffer between the distilled ethylene glycol storage tank 6 and the slurry mixer 3. In this case, in order to make the molar ratio of ethylene glycol and terephthalic acid in the slurry mixer 3 constant, the flow rate on the outlet side of the newly installed ethylene glycol storage tank is controlled.

  A slurry storage tank may be provided between the slurry mixer 3 and the esterification reactor A 4-1. In the slurry mixer, the slurry is produced continuously or discontinuously so that the molar ratio of ethylene glycol / terephthalic acid is constant. And it is preferable to store the slurry in which the molar ratio is kept constant in a slurry storage tank and to continuously supply the slurry to the esterification reaction device in a constant amount.

  Here, the “molar ratio of the diol compound to be used for the esterification reaction and the aromatic dicarboxylic acid or its ester-forming derivative” in claim 1 is supplied from the slurry mixer 3 to the esterification reactor A 4-1. The total amount of the diol compound and the recovered ethylene glycol A 19-1 returned to the esterification reactor from the lower part of the rectifying column A5-1 and "supplied from the slurry mixer 3 to the esterification reactor A4-1. Ratio of the aromatic dicarboxylic acid or ester-forming derivative thereof.

  Further, the “supply amount W1 per unit time of the diol compound to be supplied to the esterification reactor” in claim 4 is the amount of the diol compound contained in the slurry supplied from the slurry mixer 3 to the esterification reactor. Equally, “the supply amount W2 of aromatic dicarboxylic acid to be supplied to the esterification reactor per unit time” is equal to the amount of aromatic dicarboxylic acid contained in the slurry supplied from the slurry mixer 3 to the esterification reactor. .

  FIG. 2 is another conceptual diagram illustrating the present invention. The facility of FIG. 2 is characterized in that it has two esterification reactors as compared to the facility of FIG. The number of esterification reactors is not limited to two tanks, and can be two or more tanks as necessary.

  In FIG. 2, ethylene glycol, which is a combination of terephthalic acid 1, ethylene glycol 2 and ethylene glycol from distilled ethylene glycol storage tank 6, is supplied to slurry mixer 3 with a constant ethylene glycol / terephthalic acid molar ratio. Stir and mix to make a slurry. This slurry is sent to esterification reactor A 4-1. In the esterification reactor A 4-1, the esterification reaction is carried out under the conditions of 240 to 295 ° C. with stirring and normal pressure to 0.5 MPa. Subsequently, the obtained reaction product 20-1 is sent to an esterification reactor B4-2, and a polyester precursor 20-2 is produced. In the esterification reactor 4-2, the esterification reaction is further carried out under the conditions of 240 to 295 ° C. under pressure and normal pressure to 0.5 MPa. The esterification reaction produces water simultaneously with the polyester precursor. Of these water, terephthalic acid, ethylene glycol, and polyester precursor, the low boiling point component is distilled into the rectifying column A5-1. Usually, water is separated from the top of the column, and conditions are set so that ethylene glycol can be recovered from the lower part of the rectification column. More specifically, the temperature of the esterification reactor B 4-2 may be set to be equal to or lower than the temperature of the esterification reactor A 4-1, but from the viewpoint of energy saving, the esterification reactor A 4-1 It is preferable to set the temperature to be equal to or higher than this temperature. A component containing ethylene glycol from the group consisting of water, terephthalic acid, ethylene glycol and a polyester precursor is distilled from the ester reactor to the rectification column. Water produced by the esterification reaction in the esterification reactors 4-1 and 4-2 is separated as distilled water from the top of the rectification column A5-1. Ethylene glycol is separated from the lower part of the rectifying column A5-1 as a bottoms, and a predetermined amount set in advance as distilled ethylene glycol A18-1 is distilled from the esterification reactor (rectifying column A). A fixed amount is continuously taken out to the storage tank 6, and the remainder is returned to the esterification reactor A4-1 (recovered ethylene glycol A19-1). In the esterification reactor B 4-2, the polyester low polymer (polyester precursor) 20-2 almost completed in the esterification reaction is sent to the polycondensation reactor in the next step. The polyester precursor preferably has a degree of polymerization of 2 to 10 from the viewpoint of productivity and the quality of the obtained polyester. A more preferable polymerization degree range is 4-8. Setting the degree of polymerization of the polyester precursor to 2 to 10 can be achieved by controlling the amount of ethylene glycol taken from the rectifying column to be a constant amount. Here, since the number of esterification reactors is two, the range of condition setting is widened, and the polyester precursor can be stably produced.

  Further, for the same reason as in the conceptual diagram of the equipment shown in FIG. 1, the amount W per unit time for taking out the diol compound from the rectifying column provided in the esterification reactor at this time satisfies the above formula (1). It is preferable to set. More preferably, it sets so that the said Formula (2) may be satisfy | filled.

  In the polycondensation reactors 7, 8, and 9, the polyester polymer (polyethylene terephthalate 17) is produced by performing the reaction in the temperature and pressure ranges of 250 to 300 ° C. and 0.05 to 60 kPa. These polycondensation reactors are provided with wet condensers 10, 11, and 12, respectively, and the distilled ethylene glycol generated by the polycondensation reaction is condensed here, and is stored in circulating ethylene glycol storage tanks 13, 14, and 15, respectively. While being stored, it is sent to the wet condensers 10, 11, and 12 again as circulating ethylene glycol, and used as a spray liquid for condensing the distilled ethylene glycol from the polycondensation reactor.

  Each wet condenser is connected to a vacuum source by piping. In particular, a high degree of vacuum is required in the late polycondensation reactor 9. Each of the pressure loss resulting from the vapor pressure of low boiling point components such as water contained in the distilled ethylene glycol in the wet condenser 12 attached to the polycondensation reactor 9, and the polyester low polymer generated by entrainment For the purpose of preventing adhesion to equipment and piping, ethylene glycol 16 having an amount equal to or less than the amount of ethylene glycol equal to the component amount in the product polyester and having a moisture content of 0.5% or less is added to the circulating ethylene glycol storage tank 15 It is also preferable to do this.

  In the circulating ethylene glycol storage tank 15, the liquid in the storage tank is extracted so that the liquid level is constant. The extracted liquid is sent to the circulating ethylene glycol storage tank 14. Here, the extracted liquid is used as a spray liquid of the wet condenser 11 together with the distilled ethylene glycol generated in the polycondensation reactor 8. Thereafter, the liquid in the storage tank is withdrawn so that the liquid level of the circulating ethylene glycol storage tank 14 is constant, and sent to the circulating ethylene glycol storage tank 13. Then, it is used as the spray liquid of the wet condenser 10 together with the distilled ethylene glycol generated in the polycondensation reactor 7. After that, the liquid in the storage tank is extracted so that the liquid level in the circulating ethylene glycol storage tank 13 is constant, and is sent to the distilled ethylene glycol storage tank 6.

  Here, if the circulating ethylene glycol storage tanks 13 and 14 corresponding to the wet condensers 10 and 11 are unified into one tank of the circulating ethylene glycol storage tank 13, the above operation is performed only once. When there are four or more polycondensation reactors, the above operation is repeated. Further, the present invention mainly relates to an esterification reaction, particularly a rectification column installed in the esterification reaction apparatus, and therefore the polycondensation reactor is not limited to the illustrated one. For example, the polycondensation reactors disclosed in Japanese Patent Application Laid-Open Nos. 2004-2901, 2001-40080, 2000-136247, 2000-239368, 10-95843, etc. There is no problem even if it is replaced. Moreover, there is no problem even if a vertical type complete mixing tank type polycondenser or a horizontal polycondenser which is usually used is used.

  Distilled ethylene glycol collected in the ethylene glycol storage tank 6 is supplied to the slurry mixer 3 together with terephthalic acid 1. At this time, the molar ratio of ethylene glycol and terephthalic acid is controlled to be always constant. This control system may proportionally control terephthalic acid based on ethylene glycol, or may proportionally control ethylene glycol based on terephthalic acid. In order to keep the production amount of the product polyester as constant as possible, it is preferable to keep the molar ratio constant by proportionally controlling ethylene glycol based on the supply amount of terephthalic acid. For the same reason as the conceptual diagram shown in FIG. 1, the molar ratio of the diol compound and the aromatic dicarboxylic acid or ester-forming derivative thereof subjected to the transesterification reaction by these methods (diol compound / aromatic dicarboxylic acid or ester thereof) It is necessary in the present invention that the forming derivative) is 1.15 or more. If it is less than 1.15, a good slurry cannot be obtained. Further, when this ratio is 1.15 or more, a good slurry can be obtained and the esterification (exchange) reaction is stabilized, so that variations in physical properties such as intrinsic viscosity, color tone, diethylene glycol amount, etc. of the obtained polyester are reduced. preferable. In order to keep this ratio at 1.15 or more, a method of proportionally controlling ethylene glycol based on the supply amount of terephthalic acid supplied to the slurry mixer 3 as described above is usually employed. Distilled ethylene glycol from the distillate ethylene glycol storage tank 6 may contain large foreign substances and polymer denatured products. Therefore, a filter is provided between the distillate ethylene glycol tank 6 and the slurry mixer 3 to remove these. It is preferable to install. In addition, it is desirable to install another ethylene glycol supply line 2 in the slurry mixer 3 for emergency use. In addition, it is easy to install an ethylene glycol storage tank as a buffer between the distilled ethylene glycol storage tank 6 and the slurry mixer 3. In this case, in order to make the molar ratio of ethylene glycol and terephthalic acid in the slurry mixer 3 constant, the flow rate on the outlet side of the newly installed ethylene glycol storage tank is controlled.

  A slurry storage tank may be provided between the slurry mixer 3 and the esterification reactor A 4-1. In the slurry mixer, the slurry is produced continuously or discontinuously so that the molar ratio of ethylene glycol / terephthalic acid is constant. And it is preferable to store the slurry in which the molar ratio is kept constant in a slurry storage tank and to continuously supply the slurry to the esterification reaction device in a constant amount.

  Here, the “molar ratio of the diol compound to be used for the esterification reaction and the aromatic dicarboxylic acid or its ester-forming derivative” in claim 1 is supplied from the slurry mixer 3 to the esterification reactor A 4-1. The total amount of the diol compound and the recovered ethylene glycol A 19-1 returned to the esterification reactor from the lower part of the rectifying column A5-1 and "supplied from the slurry mixer 3 to the esterification reactor A4-1. Ratio of the aromatic dicarboxylic acid or ester-forming derivative thereof.

  Further, the “supply amount W1 per unit time of the diol compound to be supplied to the esterification reactor” in claim 4 is the amount of the diol compound contained in the slurry supplied from the slurry mixer 3 to the esterification reactor. Equally, “the supply amount W2 of aromatic dicarboxylic acid to be supplied to the esterification reactor per unit time” is equal to the amount of aromatic dicarboxylic acid contained in the slurry supplied from the slurry mixer 3 to the esterification reactor. .

  FIG. 3 is another conceptual diagram for explaining the present invention. The facility in FIG. 3 is characterized by two sets of esterification reaction apparatuses (esterification reactor, rectification column) as compared with the facility in FIG. Further, the number of sets of the esterification reactor and the rectification column is not limited to two sets, and may be set to two sets or more as required.

  In FIG. 3, ethylene glycol, which is a combination of terephthalic acid 1, ethylene glycol 2 and ethylene glycol from distilled ethylene glycol storage tank 6, is supplied to slurry mixer 3 with a constant ethylene glycol / terephthalic acid molar ratio. Stir and mix to make a slurry. This slurry is sent to esterification reactor A 4-1. In the esterification reactor A 4-1, the esterification reaction is carried out under the conditions of 240 to 295 ° C. with stirring and normal pressure to 0.5 MPa. Subsequently, the obtained reaction product 20-1 is sent to an esterification reactor B4-2, and a polyester precursor 20-2 is produced. In the esterification reactor B 4-2, an esterification reaction is further carried out under the conditions of 240 to 295 ° C. under stirring and normal pressure to 0.5 MPa. Water is produced simultaneously with the reaction product and the polyester precursor by the esterification reaction. Of these water, terephthalic acid, ethylene glycol, reaction product, and polyester precursor, the low boiling point component is distilled into the rectifying column A5-1 and the rectifying column B5-2. Usually, water is separated from the top of the column, and conditions are set so that ethylene glycol can be recovered from the lower part of the rectification column. More specifically, the temperature of the esterification reactor B 4-2 may be set to be equal to or lower than the temperature of the esterification reactor A 4-1, but from the viewpoint of energy saving, the esterification reactor A 4-1 It is preferable to set the temperature to be equal to or higher than this temperature. As a result, a component containing ethylene glycol from the group consisting of water, terephthalic acid, ethylene glycol, reaction product and polyester precursor is distilled from the esterification reactor to the rectification column. The water produced by the reaction in the esterification reactors 4-1 and 4-2 is distilled water from the top of the rectification tower A5-1 and rectification tower B5-2 installed in each esterification reaction apparatus. As isolated. Ethylene glycol is separated as bottoms from the lower part of the rectifying column A5-1 and the rectifying column B5-2, and a predetermined amount set in advance is distilled ethylene glycol A18-1 and distilled ethylene glycol B18-. 2 is taken out into the distillate ethylene glycol storage tank 6, and the remainder is returned to the esterification reactor A4-1 and the esterification reactor B4-2 (recovered ethylene glycol A19-1 and B19-2). In the esterification reactor B 4-2, the polyester low polymer (polyester precursor) 20-2 almost completed in the esterification reaction is sent to the polycondensation reactor in the next step. The polyester precursor preferably has a degree of polymerization of 2 to 10 from the viewpoint of productivity and the quality of the obtained polyester. A more preferable polymerization degree range is 4-8. Setting the degree of polymerization of the precursor to 2 to 10 can be achieved by controlling the amount of ethylene glycol taken out from the rectifying column to be a constant amount. Here, since the number of esterification reactors becomes two, the range of condition setting is widened, and the polyester precursor can be stably produced. Specifically, the temperature and pressure in the two sets of esterification reactors can be easily changed.

  Further, for the same reason as in the conceptual diagram of the equipment shown in FIG. 1, the amount W per unit time for taking out the diol compound from the rectifying column provided in the esterification reactor at this time satisfies the above formula (1). It is preferable to set. More preferably, it sets so that the said Formula (2) may be satisfy | filled.

  In the polycondensation reactors 7, 8, and 9, the polyester polymer (polyethylene terephthalate 17) is produced by performing the reaction in the temperature and pressure ranges of 250 to 300 ° C. and 0.05 to 60 kPa. These polycondensation reactors are provided with wet condensers 10, 11, and 12, respectively, and the distilled ethylene glycol generated by the polycondensation reaction is condensed here, and is stored in circulating ethylene glycol storage tanks 13, 14, and 15, respectively. While being stored, it is sent to the wet condensers 10, 11, and 12 again as circulating ethylene glycol, and used as a spray liquid for condensing the distilled ethylene glycol from the polycondensation reactor.

  Each wet condenser is connected to a vacuum source by piping. In particular, a high degree of vacuum is required in the late polycondensation reactor 9. Each of the pressure loss resulting from the vapor pressure of low boiling point components such as water contained in the distilled ethylene glycol in the wet condenser 12 attached to the polycondensation reactor 9, and the polyester low polymer generated by entrainment For the purpose of preventing adhesion to equipment and piping, ethylene glycol 16 having an amount equal to or less than the amount of ethylene glycol equal to the component amount in the product polyester and having a moisture content of 0.5% or less is added to the circulating ethylene glycol storage tank 15 It is also preferable to do this.

  In the circulating ethylene glycol storage tank 15, the liquid in the storage tank is extracted so that the liquid level is constant. The extracted liquid is sent to the circulating ethylene glycol storage tank 14. Here, the extracted liquid is used as a spray liquid of the wet condenser 11 together with the distilled ethylene glycol generated in the polycondensation reactor 8. Thereafter, the liquid in the storage tank is withdrawn so that the liquid level of the circulating ethylene glycol storage tank 14 is constant, and sent to the circulating ethylene glycol storage tank 13. Then, it is used as the spray liquid of the wet condenser 10 together with the distilled ethylene glycol generated in the polycondensation reactor 7. Thereafter, the liquid in the storage tank is drawn out so that the liquid level in the circulating ethylene glycol storage tank 13 is constant, and sent to the distilled ethylene glycol storage tank 6.

  Here, if the circulating ethylene glycol storage tanks 13 and 14 corresponding to the wet condensers 10 and 11 are unified into one tank of the circulating ethylene glycol storage tank 13, the above operation is performed only once. When there are four or more polycondensation reaction tanks, the above operation is repeated. Further, the present invention mainly relates to an esterification reaction, particularly a rectification column installed in the esterification reaction apparatus, and therefore the polycondensation reactor is not limited to the illustrated one. For example, the polycondensation reactors disclosed in Japanese Patent Application Laid-Open Nos. 2004-2901, 2001-40080, 2000-136247, 2000-239368, 10-95843, etc. There is no problem even if it is replaced. Moreover, there is no problem even if a vertical type complete mixing tank type polycondenser or a horizontal polycondenser which is usually used is used.

  Distilled ethylene glycol collected in the ethylene glycol storage tank 6 is supplied to the slurry mixer 3 together with terephthalic acid 1. At this time, the molar ratio of ethylene glycol and terephthalic acid is controlled to be always constant. This control system may proportionally control terephthalic acid based on ethylene glycol, or may proportionally control ethylene glycol based on terephthalic acid. In order to keep the production amount of the product polyester as constant as possible, it is preferable to keep the molar ratio constant by proportionally controlling ethylene glycol based on the supply amount of terephthalic acid. For the same reason as the conceptual diagram shown in FIG. 1, the molar ratio of the diol compound and the aromatic dicarboxylic acid or ester-forming derivative thereof subjected to the transesterification reaction by these methods (diol compound / aromatic dicarboxylic acid or ester thereof) It is necessary in the present invention that the forming derivative) is 1.15 or more. If it is less than 1.15, a good slurry cannot be obtained. Further, when this ratio is 1.15 or more, a good slurry can be obtained and the esterification (exchange) reaction is stabilized, so that variations in physical properties such as intrinsic viscosity, color tone, diethylene glycol amount, etc. of the obtained polyester are reduced. preferable. In order to keep this ratio at 1.15 or more, a method of proportionally controlling ethylene glycol based on the supply amount of terephthalic acid supplied to the slurry mixer 3 as described above is usually employed. Distilled ethylene glycol from the distillate ethylene glycol storage tank 6 may contain large foreign substances and polymer denatured products. Therefore, a filter is provided between the distillate ethylene glycol tank 6 and the slurry mixer 3 to remove these. It is preferable to install. In addition, it is desirable to install another ethylene glycol supply line 2 in the slurry mixer 3 for emergency use. In addition, it is easy to install an ethylene glycol storage tank as a buffer between the distilled ethylene glycol storage tank 6 and the slurry mixer 3. In this case, in order to make the molar ratio of ethylene glycol and terephthalic acid in the slurry mixer 3 constant, the flow rate on the outlet side of the newly installed ethylene glycol storage tank is controlled.

  It is also possible to provide a slurry storage tank between the slurry mixer 3 and the transesterification reactor. In the slurry mixer, the slurry is produced so that the molar ratio of ethylene glycol / terephthalic acid is constant continuously or discontinuously. And it is preferable to store the slurry in which the molar ratio is kept constant in a slurry storage tank and to continuously supply the slurry to the esterification reaction device in a constant amount.

  Here, the “molar ratio of the diol compound to be used for the esterification reaction and the aromatic dicarboxylic acid or its ester-forming derivative” in claim 1 is supplied from the slurry mixer 3 to the esterification reactor A 4-1. Diol and the total amount of the diol compound 19-1 returned to the esterification reactor A 4-1 from the lower part of the rectifying column A 5-1 "from the slurry mixer 3 to the esterification reactor A 4-1 Of the aromatic dicarboxylic acid or ester-forming derivative thereof supplied to

  Further, the “supply amount W1 per unit time of the diol compound to be supplied to the esterification reactor” in claim 4 is the amount of the diol compound contained in the slurry supplied from the slurry mixer 3 to the esterification reactor. Equally, “the supply amount W2 of aromatic dicarboxylic acid to be supplied to the esterification reactor per unit time” is equal to the amount of aromatic dicarboxylic acid contained in the slurry supplied from the slurry mixer 3 to the esterification reactor. .

  In carrying out the method for producing the polyester of the present invention, when an aromatic dicarboxylic acid is used, since the aromatic dicarboxylic acid itself functions as a catalyst in the esterification reaction, it is usually unnecessary to add a new catalyst. A catalyst may be added as necessary, for example, when it is desired to increase the reaction rate. On the other hand, when an ester-forming derivative of an aromatic dicarboxylic acid is used, a catalyst is usually added in the esterification reaction. Further, when any raw material is used, a catalyst is used in the polycondensation stage. As the polycondensation catalyst, a catalyst used in normal polyester production can also be used in the production method of the present invention. Specific examples include antimony compounds, germanium compounds, titanium compounds, and more specifically, antimony trioxide, germanium dioxide, titanium acetate, and tetraalkoxy titanium.

  Further, the polycondensation catalyst of the titanium compound used in the present invention is represented by the titanium compound represented by the following general formula (I), or the titanium compound represented by the following general formula (I) and the following general formula (II). Selected from the group consisting of a titanium compound component containing at least one selected from the group consisting of products obtained by reacting aromatic polycarboxylic acids or anhydrides thereof, and a phosphorus compound represented by the following general formula (III) A phosphorus compound containing at least one kind can also be used in a range where the gram equivalent ratio (P / Ti) of phosphorus atoms to titanium atoms is 1 to 15.

［上記式中、Ｒ^１、Ｒ^２、Ｒ^３及びＲ^４はそれぞれ同一若しくは異なって、アルキル基又はフェニル基を示し、ｍは１〜４の整数を示し、かつｍが２、３又は４の場合、２個、３個又は４個のＲ^２及びＲ^３は、それぞれ同一であっても異なっていてもどちらでもよい。］

[Wherein R ¹ , R ² , R ³ and R ⁴ are the same or different and each represents an alkyl group or a phenyl group, m represents an integer of 1 to 4, and m represents 2, 3 or 4] In this case, 2, 3 or 4 R ² and R ³ may be the same or different from each other. ]

［上記式中、ｎは２〜４の整数を表わす。］

[In the above formula, n represents an integer of 2 to 4. ]

［上記式中、Ｒ^５、Ｒ^６及びＲ^７は、同一又は異なって炭素原子数１〜４のアルキル基を示し、Ｘは、−ＣＨ_２−又は―ＣＨ（Ｙ）―を示す（Ｙは、ベンゼン環を示す）。］

[Wherein, R ⁵ , R ⁶ and R ⁷ are the same or different and each represents an alkyl group having 1 to 4 carbon atoms, X represents —CH ₂ — or —CH (Y) — (Y represents Represents a benzene ring). ]

  Here, as the titanium compound represented by the general formula (I), specifically, tetraisopropoxy titanium, tetrapropoxy titanium, tetra-n-butoxy titanium, tetraethoxy titanium, tetraphenoxy titanium, octaalkyl trititanate, Or hexaalkyl dititanate is preferably used.

  In addition, the aromatic polyvalent carboxylic acid represented by the general formula (II) to be reacted with the titanium compound or an anhydride thereof includes phthalic acid, trimellitic acid, hemimellitic acid, pyromellitic acid, or an anhydride thereof. Is preferably used.

  In the case of reacting the titanium compound with an aromatic polyvalent carboxylic acid or an anhydride thereof, a part or all of the aromatic polyvalent carboxylic acid or an anhydride thereof is dissolved in a solvent, and the titanium compound is dissolved in the mixed solution. It is carried out by dripping and heating at a temperature of 0-200 ° C. for at least 30 minutes, preferably at a temperature of 30-150 ° C. for 40-90 minutes. There is no restriction | limiting in particular about the reaction pressure in this case, A normal pressure is enough.

  As the solvent for dissolving the aromatic polyvalent carboxylic acid or its anhydride, one or more kinds can be selected from ethanol, ethylene glycol, trimethylene glycol, tetramethylene glycol, benzene, xylene and the like as desired.

  Here, the reaction molar ratio between the titanium compound and the aromatic polyvalent carboxylic acid or its anhydride is not particularly limited, but if the proportion of the titanium compound is too high, the color tone of the resulting polyester deteriorates, or the softening point. On the contrary, if the proportion of the titanium compound is too low, the polymerization reaction may be difficult to proceed. For this reason, it is preferable that the reaction molar ratio of a titanium compound and aromatic polyvalent carboxylic acid or its anhydride shall be in the range of 2/1-2/5. Also, there is no particular limitation as long as the above titanium compound can be reacted with the aromatic polyvalent carboxylic acid or its anhydride under other conditions.

  The polymerization catalyst system used as the polymerization catalyst in the present invention is substantially composed of an unreacted mixture of the above titanium compound component and the phosphorus compound represented by the general formula (III). , Carbomethoxymethanephosphonic acid, carboethoxymethanephosphonic acid, carbopropoxymethanephosphonic acid, carboptoxymethanephosphonic acid, carbomethoxy-phosphono-phenylacetic acid, carboethoxy-phosphono-phenylacetic acid, carboprotoxy-phosphono-phenylacetic acid Alternatively, it is preferably selected from dimethyl esters, diethyl esters, dipropyl esters, or dibutyl esters of carbobutoxy-phosphono-phenylacetic acid.

  Since the above phosphorus compound reacts relatively slowly with a titanium compound or a titanium compound component (hereinafter abbreviated as “titanium compound etc.”) as compared with a phosphorus compound usually used as a stabilizer, By maintaining the amount ratio and addition amount of the phosphorus compound and titanium compound to be used within an appropriate range, the catalyst activity duration of the titanium compound and the like during the polyester synthesis reaction is long, and as a result, the addition amount of the titanium compound to the polyester is reduced. In addition, even when a large amount of stabilizer is added to the catalyst as in the present invention, the thermal stability of the polyester is hardly impaired.

  The amount ratio of the phosphorus compound and the titanium compound is such that the gram equivalent ratio of phosphorus atom to titanium atom (P / Ti) is 1 or more and 15 or less, preferably 1 or more and 13 or less, more preferably 1 or more and 10 or less. . When this value is less than 1, the color tone of the obtained polyester may be yellowish. On the other hand, if it exceeds 15, the productivity of the polyester is inferior, and it is sometimes impossible to obtain a polyester having a desired intrinsic viscosity. Further, the addition amount is 2 or more and 15 or less when expressed as a percentage of the milligram atomic weight value of the titanium atom contained in the titanium compound or the like to the total molar amount value of the aromatic dicarboxylic acid or its ester-forming derivative unit constituting the polyester. Yes, preferably 2 or more and 12 or less, more preferably 2 or more and 10 or less. If this value is less than 2, the productivity of the polyester is inferior, and it may be impossible to obtain a polyester having a desired intrinsic viscosity. If this value exceeds 15, the resulting polyester has insufficient thermal stability. If this polyester is subjected to molding processes such as melt spinning, melt film molding, and melt bottle molding, the intrinsic viscosity is significantly reduced and the desired viscosity is lowered. A molded product having mechanical properties may not be obtained.

  On the other hand, as a polycondensation catalyst for a titanium compound used in the present invention, a titanium compound represented by the following general formula (I) and a phosphorus compound represented by the following general formula (IV) are expressed in grams of phosphorus atoms relative to titanium atoms. It is also possible to use a titanium / phosphorus reaction product reacted with a composition having an equivalent ratio (P / Ti) of 1 to 4.

［上記式中、Ｒ^１、Ｒ^２、Ｒ^３及びＲ^４はそれぞれ同一若しくは異なって、アルキル基又はフェニル基を示し、ｍは１〜４の整数を示し、かつｍが２、３又は４の場合、２個、３個又は４個のＲ^２及びＲ^３は、それぞれ同一であっても異なっていてもどちらでもよい。］

[Wherein R ¹ , R ² , R ³ and R ⁴ are the same or different and each represents an alkyl group or a phenyl group, m represents an integer of 1 to 4, and m represents 2, 3 or 4] In this case, 2, 3 or 4 R ² and R ³ may be the same or different from each other. ]

［上記式中、Ｒ^８は炭素数２〜１８のアルキル基又は炭素数６〜２０のアリール基であり、ｐは１又は２であって、ｐが１の時にｑは０又は１、ｐが２の時にｑは０である。］

[In the above formula, R ⁸ is an alkyl group having 2 to 18 carbon atoms or an aryl group having 6 to 20 carbon atoms, p is 1 or 2, and when p is 1, q is 0 or 1, and p is When 2, q is 0. ]

  Here, when the gram equivalent ratio of phosphorus atom to titanium atom (P / Ti) is smaller than 1, the color tone of the resulting polyester is poor, and its heat resistance may be lowered. The catalyst activity for the polyester formation reaction becomes insufficient, which is not preferable. The gram equivalent ratio of phosphorus atoms to titanium atoms (P / Ti) is preferably in the range of 1.2 to 3.5, and more preferably in the range of 1.5 to 3.0.

  The catalyst preparation of the titanium compound component (I) and the phosphorus compound component (IV) needs to be heated in glycol. Examples of the glycol include ethylene glycol, propylene glycol, tetramethylene glycol, hexamethylene glycol, diethylene glycol, triethylene glycol, and tetraethylene glycol. Alternatively, a mixed solvent of these and other compounds may be used. As a specific reaction method, for example, a component composed of phosphorus compound (IV) is mixed with ethylene glycol or a mixed solution of ethylene glycol and another compound, and a part or all of the phosphorus compound component is dissolved in a solvent. The titanium compound component (I) or a solution thereof is dropped into the mixed solution, and the reaction system is heated to a temperature of 0 ° C. to 200 ° C. for 30 minutes or longer, preferably 60 to 150 ° C. for 40 to 90 minutes. Is done by. In this reaction, the reaction pressure is not particularly limited and is usually carried out under normal pressure.

  Examples of the titanium compound represented by the general formula (I) include titanium tetraalkoxides such as titanium tetrabutoxide, titanium tetraisopropoxide, titanium tetrapropoxide, titanium tetraethoxide, octaalkyltrititanate, hexa Examples thereof include alkyl dititanates and alkyl titanates.

  In addition, as the phosphorus compound represented by the above formula (IV), when q in the formula is 0, for example, phenylphosphonic acid, methylphosphonic acid, ethylphosphonic acid, propylphosphonic acid, isopropylphosphonic acid, butylphosphonic acid, tolyl Phosphonic acid, xylylphosphonic acid, biphenylphosphonic acid, naphthylphosphonic acid, anthrylphosphonic acid, 2-carboxyphenylphosphonic acid, 3-carboxyphenylphosphonic acid, 4-carboxyphenylphosphonic acid, 2,3-dicarboxyphenylphosphonic Acid, 2,4-dicarboxyphenylphosphonic acid, 2,5-dicarboxyphenylphosphonic acid, 2,6-dicarboxyphenylphosphonic acid, 3,4-dicarboxyphenylphosphonic acid, 3,5-dicarboxyphenylphosphonic acid Acid, 2,3,4-tricarboxyl Nylphosphonic acid, 2,3,5-tricarboxyphenylphosphonic acid, 2,3,6-tricarboxyphenylphosphonic acid, 2,4,5-tricarboxyphenylphosphonic acid, 2,4,6-tricarboxyphenylphosphonic acid Among them, monoarylphosphonic acid is preferable.

  When q is 1, for example, monomethyl phosphate, monoethyl phosphate, monotrimethyl phosphate, monobutyl phosphate, monohexyl phosphate, monoheptyl phosphate, monononyl phosphate, monodecyl phosphate, monododecyl phosphate, monophenyl phosphate, mono Benzyl phosphate, mono (4-dodecyl) phenyl phosphate, mono (4-methylphenyl) phosphate, mono (4-ethylphenyl) phosphate, mono (4-propylphenyl) phosphate, mono (4-dodecylphenyl) phosphate, monotolyl Examples include phosphate, monoxyl phosphate, monobiphenyl phosphate, mononaphthyl phosphate, monoanthryl phosphate and the like.

  A method in which the titanium compound represented by the general formula (I) is used by reacting with a polyvalent carboxylic acid of the following general formula (II) and / or its anhydride in advance is also preferably used. In that case, the reaction molar ratio of the titanium compound and the polyvalent carboxylic acid and / or anhydride thereof is preferably in the range of 2/1 to 0.4 / 1. A particularly preferable range is 1/1 to 0.5 / 1.

［上記式中、ｎは２〜４の整数を表わす。］

[In the above formula, n represents an integer of 2 to 4. ]

  The amount of the titanium / phosphorus compound obtained by reacting the titanium compound and the phosphorus compound as described above with an appropriate composition ratio is the aromatic dicarboxylic acid constituting the polyester having the milligram atomic weight value of the titanium atom contained in the compound. Alternatively, it is 2 or more and 40 or less, preferably 2 or more and 35 or less, more preferably 2 or more and 30 or less when expressed as a percentage with respect to the total molar amount of the ester-forming derivative unit. If this value is less than 2, the productivity of the polyester is inferior, and it may be impossible to obtain a polyester having a desired intrinsic viscosity. If this value exceeds 40, the thermal stability of the resulting polyester will be insufficient, and if this polyester is subjected to molding processes such as melt spinning, melt film molding, and melt bottle molding, the intrinsic viscosity will be significantly reduced and the desired viscosity will be reduced. A molded product having mechanical properties may not be obtained.

  After the above two types of catalyst systems are produced by the above-described method, they can be used as a polyester polycondensation catalyst by the same operation using the same amount as that of other commonly used polyester catalysts.

Hereinafter, the present invention will be specifically described with reference to examples. In addition, each value in an Example was calculated | required according to the following method. In Examples and Comparative Examples, “parts” represents a ratio expressed by weight.
(A) Intrinsic viscosity After 0.6 g of polyester sampled at regular intervals was dissolved in 50 ml of orthochlorophenol by heating, it was cooled to room temperature. The viscosity of the obtained polyester solution was measured at 35 ° C. using an Ostwald type viscosity tube. The intrinsic viscosity of the polyester was determined from the obtained solution viscosity value. Ten samples were measured and the average and standard deviation were determined.

(B) Color tone (L value and b value)
A polyester sample sampled at regular intervals was melted at 290 ° C. under vacuum for 10 minutes, and after being formed into a plate having a thickness of 3.0 ± 1.0 mm on an aluminum plate, it was immediately cooled in ice water. The plate was dried and crystallized at 160 ° C. for 1 hour, then placed on a white standard plate for color difference adjustment, and the Hunter L and b values on the plate surface were measured using a Minolta Hunter color difference meter CR-200. did. The L value indicates the lightness, and the larger the value, the higher the lightness, and the b value the greater the value, the greater the degree of yellowing. Ten samples were measured and the average and standard deviation were determined.

(C) Terminal carboxyl group concentration The method of Maurice et al. [Anal. Chim. Acta, 22, p363 (1960)], the number of equivalents (eq / T) per 10 ⁶ g of the polyester sample. Ten samples sampled at regular intervals were measured, and an average value and a standard deviation were obtained.

(D) Diethylene glycol (DEG) content in polyester A polyester sample sampled at regular intervals using hydrazine hydrate was decomposed, and the content of diethylene glycol in the decomposition product was determined by gas chromatography (HP6850 manufactured by Hewlett-Packard Company). ) And expressed in weight%. Ten samples were measured and the average and standard deviation were determined.

(E) Fineness spots The polyester sample was dried at 160 ° C. for 4 hours, then formed into a long fiber shape by a usual melt spinning method, and measured at a running speed of 400 m / min using a USTER TESTER type 4 manufactured by Zerberger Wooster. did. The values were obtained 1 hour, 1 day and 2 days after the start of spinning.

(F) Dye spots The polyester sample was formed into a long fiber by the above-mentioned method, and it was made into a 30 cm long tube knitting with a 12 gauge circular knitting machine, and dyed at 100 ° C. for 40 minutes using a dye (terra seal blue GFL). The level dyeability was judged visually. The values were obtained 1 hour, 1 day and 2 days after the start of spinning.
Level 1: Uniformly dyed and scars are hardly observed.
Level 2: Some stripes or spots are observed.
Level 3: Striped or speckled spots are observed on one side.

(G) Thickness unevenness After drying the polyester sample, the thickness (μm) was determined from the weight of the sample cut into a size of 50 mm × 50 mm from the bottle body by molding into a hollow container shape with an internal volume of 1.5 liters. This measurement was performed on 10 bottles sampled at regular intervals in the molding process, and the average value and the standard deviation were obtained.

(H) Haze After the polyester sample was dried, it was molded into a hollow container having an internal volume of 1.5 liters. A sample cut into a size of 50 mm × 50 mm from the body of the hollow container sampled at regular time intervals in the molding process was measured with Nippon Denshoku Industries Color and color difference meter MODEL1001DP. The results are shown in%.

(I) Degree of polymerization A sample of the esterification reactor was sampled and the method of Maurice et al. [Anal. Chim. Acta, 22, p363 (1960)], the amount of carboxyl end groups was measured. Next, the amount of hydroxyl end groups was determined by dissolving the sample in hexafluoroisopropanol and using ¹³ C-NMR for this solution. Further, the number average molecular weight was determined from the amounts of both terminal groups, and converted to the degree of polymerization.

[Example 1]
1, 100 parts per unit time of terephthalic acid from one pipe and 45 parts of ethylene glycol per unit time from the distillate ethylene glycol storage tank 6 are continuously supplied to the slurry mixer 3 in the polyester production facility of FIG. A good slurry was prepared. On the other hand, ethylene glycol was previously supplied to the esterification reactor so that the molar ratio of ethylene glycol / terephthalic acid in the esterification reactor was 1.6, and the esterification reactor A 4- The slurry was fed continuously to 1. Next, the slurry was esterified at 270 ° C. and normal pressure, and water produced as a by-product was taken out from the top of the rectification column to the outside of the esterification reaction apparatus to obtain a polyester precursor having an average degree of polymerization of 7. At this time, the amount of ethylene glycol taken out from the lower part of the rectifying column A5-1 to the outside of the esterification reactor was 1.5 parts per unit time. And the excess rectifying column lower part liquid was returned to esterification reactor A4-1 so that the liquid level of the lower part of a rectifying column might become constant constantly.

Ｗ＝４５−（７＋１）×６２×１００／７／１６６＝２．３１５（部／単位時間） At this time, the right side of the formula (1) can be calculated as follows. That is, since the above equation (1) is expressed as follows, W can be calculated as follows.

W = 45− (7 + 1) × 62 × 100/7/166 = 2.315 (part / unit time)

  To this polyester precursor, 0.044 parts of antimony trioxide, 0.001 part of orthophosphoric acid, and 3.4 parts of ethylene glycol slurry of titanium dioxide having a concentration of 10 wt% were added and then sent to a polycondensation reactor. Polyester was obtained by reacting at 275 ° C. and 6.9 kPa in the polycondensation reactor 7, 280 ° C. and 0.7 kPa in the polycondensation reactor 8 and 284 ° C. and 0.2 kPa in the polycondensation reactor 9. Further, this polyester was extracted in a strand shape and cooled with water, and then cut into a chip shape to obtain a polyester chip.

  After the chips were dried, the oil agent was applied to the spun yarn that was melted and discharged from the spinneret at 288 ° C. and cooled and solidified. After applying interlace with an interlace applying device as required, the undrawn yarn was once wound around a winder through a pair of take-up rollers set at room temperature. Subsequently, the obtained undrawn yarn was drawn at a draw ratio of 2.5 times through a preheating roller heated to 90 ° C. at a drawing speed of 1400 m / min and a non-contact heater set at 220 ° C. to obtain long fibers. Table 1 shows the quality of polyester and long fibers.

[Example 2]
In the polyester production facility of FIG. 2, 100 parts of terephthalic acid per unit time from one pipe and 48 parts of ethylene glycol from a distilled ethylene glycol storage tank 6 per unit time are continuously supplied to the slurry mixer 3. A good slurry was prepared. On the other hand, ethylene glycol was previously supplied to the esterification reactor A4-1 so that the ethylene glycol / terephthalic acid molar ratio in the esterification reactor A4-1 was 1.65, and a slurry mixer The slurry was continuously supplied from 3 to the esterification reactor A 4-1. Next, the slurry was subjected to an esterification reaction under a pressure of 270 ° C. and 0.04 MPa, and then the reaction product was sent to the esterification reactor B 4-2 for further esterification reaction at 273 ° C. and normal pressure. Water produced as a by-product in the esterification reaction was taken out from the top of the rectification column to the outside of the esterification reaction apparatus to obtain a polyester precursor having an average degree of polymerization of 5. At this time, the amount of ethylene glycol taken out from the lower part of the rectifying column A5-1 to the outside of the esterification reaction apparatus was 2.7 parts per unit time. And the excess rectifying column lower part liquid was returned to esterification reactor A4-1 so that the liquid level of the lower part of a rectifying column might become constant constantly.

  To this polyester precursor, 0.036 parts of antimony acetate and 1.7 parts of ethylene glycol slurry of titanium dioxide having a concentration of 20 wt% were added and then sent to a polycondensation reactor. Polyester was obtained by reacting at 275 ° C. and 6.9 kPa in the polycondensation reactor 7, 280 ° C. and 0.7 kPa in the polycondensation reactor 8 and 284 ° C. and 0.2 kPa in the polycondensation reactor 9.

  Further, this polyester was discharged from the spinneret in a molten state without being cooled and solidified, and an oil agent was applied to the cooled and solidified spun yarn and taken up at a speed of 3300 m / min. The yarn was entangled with air while passing through an interlace nozzle having a compressed air blowing hole having a hole diameter of 1.8 mm. Further, the yarn was stretched and false twisted at a speed of 800 m / min using a urethane disk having a draw ratio of 1.60, a first heater first half temperature of 550 ° C., a first heater second half temperature of 350 ° C. and a thickness of 9 mm as a false twist disk. . Table 1 shows the quality of polyester and long fibers.

[Example 3]
3, 100 parts of terephthalic acid per unit time from one pipe and 53 parts of ethylene glycol per unit time from the distillate ethylene glycol storage tank 6 are continuously supplied to the slurry mixer 3 from one pipe. Thus, a good slurry was prepared. On the other hand, ethylene glycol was previously supplied to the esterification reactor A 4-1 so that the ethylene glycol / terephthalic acid molar ratio in the esterification reactor 4-1 was 1.5, and the slurry mixer 3 The slurry was continuously supplied to the esterification reactor A 4-1. Next, the slurry is esterified under a pressure of 265 ° C. and 0.02 MPa, and water produced as a by-product in the esterification reaction is taken out from the top of the rectifying column A5-1 to the outside of the esterification reactor, and the average degree of polymerization is obtained. A polyester precursor of 3 was obtained. At this time, the amount of ethylene glycol taken out from the lower part of the rectifying column A5-1 to the outside of the esterification reaction apparatus was 1.6 parts per unit time. And the excess rectifying column lower part liquid was returned to esterification reactor A4-1 so that the liquid level of the lower part of a rectifying column might become constant constantly. Subsequently, the reaction product was sent to the esterification reactor B4-2, and further esterified at 270 ° C. and normal pressure. Water produced as a by-product in the esterification reaction was taken out from the top of the rectifying column B 5-2 to obtain a polyester precursor having an average degree of polymerization of 7. At this time, the amount of ethylene glycol taken out from the lower part of the rectifying column B5-2 was 5.0 parts per unit time. And the excess rectification column lower part liquid was returned to esterification reactor B4-2 so that the liquid level of the rectification column lower part was always constant.

  After adding 0.040 part of antimony trioxide and 1.7 part of ethylene glycol slurry of titanium dioxide having a concentration of 20 wt% to this polyester precursor, it was sent to a polycondensation reactor. Polyester was obtained by reacting at 275 ° C. and 6.9 kPa in the polycondensation reactor 7, 280 ° C. and 0.7 kPa in the polycondensation reactor 8 and 284 ° C. and 0.2 kPa in the polycondensation reactor 9.

  Further, this polyester is discharged from the spinneret in a molten state without being cooled and solidified, and an oil agent is applied to the spun yarn that has been cooled and solidified, and taken up at a speed of 3300 m / min. The yarn was entangled with air while passing through an interlace nozzle having a compressed air blowing hole having a hole diameter of 1.8 mm. Further, the yarn was drawn using a urethane disk having a draw ratio of 1.60, a first heater first half temperature of 550 ° C., a first heater latter half temperature of 350 ° C. and a thickness of 9 mm as a false twist disk, and drawn at a speed of 800 m / min. did. Table 1 shows the quality of polyester and long fibers.

[Example 4]
1, 100 parts per unit time of terephthalic acid from one pipe and 52 parts of ethylene glycol per unit time from the distilled ethylene glycol storage tank 6 are continuously supplied to the slurry mixer 3 in the polyester production facility of FIG. A good slurry was prepared. On the other hand, ethylene glycol was previously supplied to the esterification reactor so that the molar ratio of ethylene glycol / terephthalic acid in the esterification reactor was 1.5, and the esterification reactor A 4- The slurry was fed continuously to 1. Next, the slurry was subjected to esterification reaction at 275 ° C. and normal pressure, and by-product water was taken out from the top of the rectification column to the outside of the esterification reaction apparatus to obtain a polyester precursor having an average polymerization degree of 6. At this time, the amount of ethylene glycol taken out from the lower part of the rectifying column A5-1 to the outside of the esterification reaction apparatus was 8.4 parts per unit time. And the excess rectifying column lower part liquid was returned to the esterification reactor A4-1 so that the liquid level of the lower part of the rectifying column was always constant.

  To this polyester precursor, 0.044 parts of antimony trioxide, 0.001 part of orthophosphoric acid, and 3.4 parts of ethylene glycol slurry of titanium dioxide having a concentration of 10 wt% were added and then sent to a polycondensation reactor. Polyester was obtained by reacting at 275 ° C. and 6.9 kPa in the polycondensation reactor 7, 280 ° C. and 0.7 kPa in the polycondensation reactor 8 and 284 ° C. and 0.2 kPa in the polycondensation reactor 9. Further, this polyester was extracted in a strand shape and cooled with water, and then cut into a chip shape to obtain a polyester chip. After the chips were dried, the oil agent was applied to the spun yarn that was melted and discharged from the spinneret at 288 ° C. and cooled and solidified. After applying interlace with an interlace applying device as required, the undrawn yarn was once wound around a winder through a pair of take-up rollers set at room temperature. Next, the obtained undrawn yarn was drawn at a draw ratio of 2.5 times through a preheating roller heated to 90 ° C. at a drawing speed of 1400 m / min and a non-contact heater set at 220 ° C. to obtain long fibers. Table 1 shows the quality of polyester and long fibers.

[Example 5]
2, 100 parts per unit time of terephthalic acid from one pipe and 55 parts of ethylene glycol per unit time from the distilled ethylene glycol storage tank 6 are continuously supplied to the slurry mixer 3 in the polyester production facility of FIG. A good slurry was prepared. On the other hand, ethylene glycol was previously supplied to the esterification reactor so that the ethylene glycol / terephthalic acid molar ratio in the esterification reactor was 1.60, and the esterification reactor A 4- The slurry was fed continuously to 1. Next, the slurry was esterified under a pressure of 272 ° C. and 0.04 MPa, and then the reaction product was sent to the esterification reactor B 4-2 for further esterification at 276 ° C. and normal pressure. Water produced as a by-product in the esterification reaction was taken out from the top of the rectifying column to the outside of the esterification reaction apparatus to obtain a polyester precursor having an average degree of polymerization of 6. At this time, the amount of ethylene glycol taken out from the lower part of the rectifying column A5-1 to the outside of the esterification reaction apparatus was 11.0 parts per unit time. And the excess rectifying column lower part liquid was returned to esterification reactor A4-1 so that the liquid level of the lower part of a rectifying column might become constant constantly.

  To this polyester precursor, 0.036 parts of antimony acetate and 1.7 parts of ethylene glycol slurry of titanium dioxide having a concentration of 20 wt% were added and then sent to a polycondensation reactor. Polyester was obtained by reacting at 275 ° C. and 6.9 kPa in the polycondensation reactor 7, 280 ° C. and 0.7 kPa in the polycondensation reactor 8 and 284 ° C. and 0.2 kPa in the polycondensation reactor 9.

  Further, this polyester is discharged from the spinneret in a molten state without being cooled and solidified, and an oil agent is applied to the spun yarn that has been cooled and solidified, and taken up at a speed of 3300 m / min. The yarn was entangled with air while passing through an interlace nozzle having a compressed air blowing hole having a hole diameter of 1.8 mm. Further, the yarn was drawn and twisted at a speed of 800 m / min using a urethane disk having a draw ratio of 1.60, a first heater first half temperature of 550 ° C., a first heater second half temperature of 350 ° C. and a thickness of 9 mm as a false twist disk. . Table 1 shows the quality of polyester and long fibers.

[Example 6]
-Preparation of titanium compound 919 parts of ethylene glycol and 10 parts of acetic acid were mixed, and 71 parts of titanium tetrabutoxide was slowly added to this mixture to prepare a transparent ethylene glycol solution of the titanium compound. When the titanium concentration of this solution was measured using fluorescent X-rays, it was 1.02%.

-Preparation of phosphorus compound 537 parts of ethylene glycol was heated to 100 ° C with stirring. When that temperature was reached, 28.3 parts of monobutyl phosphate was added and dissolved with heating and stirring.

-Preparation of catalyst The phosphorus compound solution prepared as described above was controlled at a temperature of 70 ° C, and the titanium compound solution prepared as described above was slowly added thereto. The amount added was adjusted so that the gram equivalent ratio of phosphorus atoms to titanium atoms was 2.0. And it was made to react at 70 degreeC for 1 hour. The obtained reaction product was insoluble in ethylene glycol and existed as a fine precipitate.
In order to analyze this reaction precipitate, a sample of the obtained reaction solution was filtered through a filter having a pore size of 5 μm to collect the reaction precipitate as a solid, which was washed with water and dried. When this solid was analyzed with an energy dispersive X-ray microanalyzer (EMAX-7000 manufactured by Horiba, Ltd.), the titanium concentration was 17.0% and the phosphorus concentration was 21.2%. The gram equivalent ratio (P / Ti) was 1.9.

Polyester production In the polyester production facility shown in FIG. 1, 100 parts of terephthalic acid per unit time from one pipe and 45 parts of ethylene glycol from a distillate ethylene glycol storage tank 6 per unit time are continuously supplied to the slurry mixer 3. To provide a good slurry. On the other hand, ethylene glycol was previously supplied to the esterification reactor so that the molar ratio of ethylene glycol / terephthalic acid in the esterification reactor was 1.6, and the esterification reactor A 4- The slurry was fed continuously to 1. Next, the slurry was esterified at 270 ° C. and normal pressure, and water produced as a by-product was taken out from the top of the rectification column to the outside of the esterification reaction apparatus to obtain a polyester precursor having an average degree of polymerization of 7. At this time, the amount of ethylene glycol taken out from the lower part of the rectifying column A5-1 to the outside of the esterification reaction apparatus was 1.5 parts per unit time. And the excess rectifying column lower part liquid was returned to esterification reactor A4-1 so that the liquid level of the lower part of a rectifying column might become constant constantly.

  After adding 0.0088 catalyst solids prepared as described above and 3.4 parts of ethylene glycol slurry of titanium dioxide having a concentration of 10 wt% to the polyester precursor, the polyester precursor was sent to a polycondensation reactor. Polyester was obtained by reacting at 275 ° C. and 6.9 kPa in the polycondensation reactor 7, 280 ° C. and 0.7 kPa in the polycondensation reactor 8 and 284 ° C. and 0.2 kPa in the polycondensation reactor 9. Further, this polyester was extracted in a strand shape and cooled with water, and then cut into a chip shape to obtain a polyester chip.

  After the chips were dried, the oil agent was applied to the spun yarn that was melted and discharged from the spinneret at 288 ° C. and cooled and solidified. After applying interlace with an interlace applying device as required, the undrawn yarn was once wound around a winder through a pair of take-up rollers set at room temperature. Subsequently, the obtained undrawn yarn was drawn at a draw ratio of 2.5 times through a preheating roller heated to 90 ° C. at a drawing speed of 1400 m / min and a non-contact heater set at 220 ° C. to obtain long fibers. Table 1 shows the quality of polyester and long fibers. In this polyester, the Ti element was 13 ppm and the P element was 16 ppm.

[Example 7]
Preparation of Titanium Compound Tetrabutoxy titanium was added to an ethylene glycol solution in which 2 parts of trimellitic anhydride was mixed with 98 parts of ethylene glycol so that the molar ratio to trimellitic anhydride was 0.5. The mixture is kept at 80 ° C. under normal pressure for 60 minutes, then cooled to room temperature, the product is recrystallized with 10 times its amount of acetone, and the precipitate is filtered off and removed at 100 ° C. for 2 hours. The desired titanium compound was prepared by drying for a period of time.

Polyester production In the polyester production facility shown in FIG. 1, 100 parts of terephthalic acid per unit time from one pipe and 45 parts of ethylene glycol from a distillate ethylene glycol storage tank 6 per unit time are continuously supplied to the slurry mixer 3. To provide a good slurry. On the other hand, ethylene glycol was previously supplied to the esterification reactor so that the molar ratio of ethylene glycol / terephthalic acid in the esterification reactor was 1.6, and the esterification reactor A 4- The slurry was fed continuously to 1. Next, the slurry was esterified at 270 ° C. and normal pressure, and water produced as a by-product was taken out from the top of the rectifying column to a system esterification reactor to obtain a polyester precursor having an average degree of polymerization of 7. At this time, the amount of ethylene glycol taken out from the lower part of the rectifying column A5-1 to the outside of the esterification reaction apparatus was 1.5 parts per unit time. And the excess rectifying column lower part liquid was returned to esterification reactor A4-1 so that the liquid level of the lower part of a rectifying column might become constant constantly.

  To this polyester precursor was added 0.018 part of the catalyst solid prepared as described above, 0.040 part of triethylphosphonoacetate and 3.4 part of ethylene glycol slurry of titanium dioxide having a concentration of 10 wt%, and then polycondensation. Sent to reactor. The gram equivalent ratio (P / Ti) of phosphorus atoms to titanium atoms in this catalyst solid was 5.0. Subsequently, the reaction was conducted at 275 ° C. and 6.9 kPa in the polycondensation reactor 7, at 280 ° C. and 0.7 kPa in the polycondensation reactor 8, and at 284 ° C. and 0.2 kPa in the polycondensation reactor 9 to obtain a polyester. Further, this polyester was extracted in a strand shape and cooled with water, and then cut into a chip shape to obtain a polyester chip.

  After the chips were dried, the oil agent was applied to the spun yarn that was melted and discharged from the spinneret at 288 ° C. and cooled and solidified. After applying interlace with an interlace applying device as required, the undrawn yarn was once wound around a winder through a pair of take-up rollers set at room temperature. Subsequently, the obtained undrawn yarn was drawn at a draw ratio of 2.5 times through a preheating roller heated to 90 ° C. at a drawing speed of 1400 m / min and a non-contact heater set at 220 ° C. to obtain long fibers. Table 1 shows the quality of polyester and long fibers. The Ti element in the polyester was 15 ppm, and the P element was 48 ppm.

[Comparative Example 1]
In Example 1, an excess of the rectifying column lower liquid is returned to the esterification reactor so that the liquid level in the rectifying column lower part is always constant, from the lower part of the rectifying column A 5-1 to the esterification reactor A. Changed to return 1.9 parts per unit time to 4-1. Further, the amount of ethylene glycol taken out from the lower part of the rectifying column is 1.5 parts per unit time, so that the liquid level in the lower part of the rectifying column is constantly constant so that the liquid level in the lower part of the rectifying column is always constant. A polyester and long fibers were obtained in the same manner as in Example 1 except that the storage tank 6 was changed to take out. Table 2 shows the quality of the polyester and long fibers.

[Comparative Example 2]
In Example 2, instead of setting the amount of ethylene glycol taken out from the lower part of the rectifying column A 5-1 to 2.7 parts per unit time, the esterification reactor A 4 was supplied from the lower part of the rectifying column A 5-1. 2.5 parts ethylene glycol per unit time was returned to -1. Further, instead of returning the excess rectification column lower liquid to the esterification reactor A 4-1 so that the liquid level at the lower part of the rectification column is always constant, the liquid level at the lower part of the rectification column is always constant. Thus, it was decided to take out the excess rectifying column lower liquid into the distilled ethylene glycol storage tank 6. Except for these changes, polyesters and long fibers were obtained in the same manner as in Example 2. Table 2 shows the quality of the polyester and long fibers.

[Comparative Example 3]
In Example 3, the amount of ethylene glycol taken out from the lower part of the rectifying column A5-1 is 1.6 parts per unit time so that the liquid level at the lower part of the rectifying column A5-1 is always constant. Returning the excess rectifying column lower liquid to the esterification reactor A 4-1, 1.5 parts of ethylene glycol from the lower part of the rectifying column A 5-1 per unit time of the esterification reactor A 4-1. The excess rectifying column lower liquid is extracted into the distilled ethylene glycol storage tank 6 so that the liquid level in the lower part of the rectifying column A 5-1 is always constant. Furthermore, the amount of ethylene glycol taken out from the lower part of the rectifying column B5-2 is 5.0 parts per unit time, and the excess rectifying column is set so that the liquid level in the lower part of the rectifying column B5-2 is always constant. Returning the lower liquid to the esterification reactor B 4-2 returns 5.0 parts of ethylene glycol per unit time from the lower part of the rectification column 5-2 to the esterification reactor B 4-2, and the rectification column B 5. -2 was changed to withdraw the excess rectifying column lower liquid into the ethylene glycol storage tank 6 so that the liquid level at the lower part of -2 was always constant. Except for these changes, polyesters and long fibers were obtained in the same manner as in Example 3. Table 2 shows the quality of the polyester and long fibers.

[Comparative Example 4]
In Example 5, a polyester was synthesized in exactly the same manner as in Example 5 except that no ethylene glycol was taken out from the lower part of the rectifying column A5-1. Only polyester with a low intrinsic viscosity was obtained, and could not be processed into long fibers.

[Example 8]
In the polyester production facility of FIG. 2, 100 parts of terephthalic acid per unit time from one pipe and 48 parts of ethylene glycol from a distilled ethylene glycol storage tank 6 per unit time are continuously supplied to the slurry mixer 3. A good slurry was prepared. On the other hand, ethylene glycol is supplied to the esterification reactor A 4-1 in advance so that the ethylene glycol / terephthalic acid molar ratio in the esterification reactor is 1.55, and the esterification reaction is performed from the slurry mixer 3. The slurry was continuously supplied to the vessel A 4-1. Next, the slurry was subjected to an esterification reaction at 265 ° C. and normal pressure, and then the reaction product was sent to the esterification reactor B 4-2 for further esterification reaction at 270 ° C. and normal pressure. Water produced as a by-product in the esterification reaction was taken out from the top of the rectifying column to the outside of the esterification reaction apparatus to obtain a polyester precursor having an average degree of polymerization of 6. At this time, the amount of ethylene glycol taken out from the lower part of the rectifying column A5-1 to the outside of the esterification reaction apparatus was 4.0 parts per unit time. And the excess rectifying column lower part liquid was returned to esterification reactor A4-1 so that the liquid level of the lower part of a rectifying column might become constant constantly.

  0.043 part of an ethylene glycol solution of trimethyl phosphate (phosphorus concentration (weight ratio of phosphorus element in the solution) 5.5 wt%) and an ethylene glycol solution of germanium dioxide (germanium dioxide concentration of 1 wt%) were added to this polyester precursor. After adding 95 parts, it sent to the polycondensation reactor. Polyester was obtained by reacting at 275 ° C. and 6.9 kPa in the polycondensation reactor 7, 280 ° C. and 0.7 kPa in the polycondensation reactor 8 and 284 ° C. and 0.2 kPa in the polycondensation reactor 9. The produced polyester was extracted in the form of a strand from the extraction port provided at the bottom of the polycondensation reactor 9 and cooled with water, and then cut into a chip to obtain a polyester chip.

  After the obtained polyester chip is crystallized with a stirring flow type crystallizer, it is dried at 140 ° C. under a nitrogen flow, then transferred to a packed column type solid phase polymerization tower and subjected to solid phase polymerization at 215 ° C. under a nitrogen flow. Chip-shaped polyethylene terephthalate was produced.

  2. The obtained polyethylene terephthalate chip was dried at 160 ° C. with a vacuum dryer, and then with an injection molding machine (M-100DM manufactured by Meiki Seisakusho Co., Ltd.), the cylinder temperature was 275 ° C., the screw rotation speed was 160 rpm, and the primary pressure time was 3. A cylindrical preform having an outer diameter of about 28 mm, an inner diameter of about 19 mm, a length of 136 mm, and a weight of about 56 g was injection molded at 0 seconds, a mold temperature of 10 ° C., and a cycle of 30 seconds.

Subsequently, only the portion corresponding to the bottle mouth portion of the preform was crystallized at 160 ° C. for 1 minute using a stopper crystallization apparatus (infrared heater). Thereafter, the preform surface temperature is preheated to about 110 ° C. with an infrared heater, stretch blow molding is performed with a blow molding machine set at a blow pressure of 5 to 40 kg / cm ² and a mold temperature of 150 ° C., and the average thickness of the body is 330 μm. A bottle with an internal volume of about 1.5 liters was molded. Table 3 shows the quality of the polyester and bottle after the solid phase polymerization.

[Example 9]
1, 100 parts per unit time of terephthalic acid from one pipe and 45 parts of ethylene glycol per unit time from the distillate ethylene glycol storage tank 6 are continuously supplied to the slurry mixer 3 in the polyester production facility of FIG. A good slurry was prepared. On the other hand, the ethylene glycol is supplied to the esterification reactor A 4-1 in advance so that the ethylene glycol / terephthalic acid molar ratio in the esterification reactor becomes 1.4, and the esterification reaction is performed from the slurry mixer 3. The slurry was continuously supplied to the vessel A 4-1. Next, the slurry was esterified at 265 ° C. and normal pressure, and water produced as a by-product was taken out from the top of the rectifying column to the outside of the esterification reactor to obtain a polyester precursor having an average degree of polymerization of 6. At this time, the amount of ethylene glycol taken out from the lower part of the rectifying column A5-1 to the outside of the esterification reactor was 1.3 parts per unit time. And the excess rectifying column lower part liquid was returned to esterification reactor A4-1 so that the liquid level of the lower part of a rectifying column might become constant constantly.

  0.038 part of an ethylene glycol solution of trimethyl phosphate (phosphorus concentration (weight ratio of phosphorus element in the solution) 5.5 wt%) and an ethylene glycol solution of germanium dioxide (germanium dioxide concentration of 1 wt%) were added to this polyester precursor. After adding 97 parts, it was sent to a polycondensation reactor. Polyester was obtained by reacting at 275 ° C. and 6.9 kPa in the polycondensation reactor 7, 278 ° C. and 0.7 kPa in the polycondensation reactor 8, and 280 ° C. and 0.2 kPa in the polycondensation reactor 9. The produced polyester was extracted in the form of a strand from the extraction port provided at the bottom of the polycondensation reactor 9 and cooled with water, and then cut into a chip to obtain a polyester chip.

  After the obtained polyester chip is crystallized with a stirring flow type crystallizer, it is dried at 140 ° C. under a nitrogen flow, then transferred to a packed column type solid phase polymerization tower and subjected to solid phase polymerization at 215 ° C. under a nitrogen flow. Chip-shaped polyethylene terephthalate was produced.

  2. The obtained polyethylene terephthalate chip was dried at 160 ° C. with a vacuum dryer, and then with an injection molding machine (M-100DM manufactured by Meiki Seisakusho Co., Ltd.), the cylinder temperature was 275 ° C., the screw rotation speed was 160 rpm, and the primary pressure time was 3. A cylindrical preform having an outer diameter of about 28 mm, an inner diameter of about 19 mm, a length of 136 mm, and a weight of about 56 g was injection molded at 0 seconds, a mold temperature of 10 ° C., and a cycle of 30 seconds.

Subsequently, only the portion corresponding to the bottle mouth portion of the preform was crystallized using a stopper crystallizing device (infrared heater) at 160 ° C. for 1 minute. Thereafter, the preform surface temperature is preheated to about 110 ° C. with an infrared heater, stretch blow molding is performed with a blow molding machine set at a blow pressure of 5 to 40 kg / cm ² and a mold temperature of 150 ° C., and the average thickness of the body is 330 μm. A bottle with an internal volume of about 1.5 liters was molded. Table 3 shows the quality of the polyester and bottle after the solid phase polymerization.

[Example 10]
2, 100 parts per unit time of terephthalic acid from one pipe and 52 parts of ethylene glycol per unit time from the distilled ethylene glycol storage tank 6 are continuously supplied to the slurry mixer 3 in the polyester production facility of FIG. A good slurry was prepared. On the other hand, ethylene glycol is supplied to the esterification reactor A 4-1 in advance so that the ethylene glycol / terephthalic acid molar ratio in the esterification reactor is 1.65, and the esterification reaction is started from the slurry mixer 3. The slurry was continuously supplied to the vessel A 4-1. Next, the slurry was subjected to an esterification reaction at 265 ° C. and normal pressure, and then the reaction product was sent to the esterification reactor B 4-2 for further esterification reaction at 268 ° C. and normal pressure. Water produced as a by-product in the esterification reaction was taken out from the top of the rectifying column to the outside of the esterification reaction apparatus to obtain a polyester precursor having an average degree of polymerization of 6. At this time, the amount of ethylene glycol taken out from the lower part of the rectifying column A5-1 to the outside of the esterification reaction apparatus was 8.3 parts per unit time. And the excess rectifying column lower part liquid was returned to esterification reactor A4-1 so that the liquid level of the lower part of a rectifying column might become constant constantly.

  0.043 part of an ethylene glycol solution of trimethyl phosphate (phosphorus concentration (weight ratio of phosphorus element in the solution) 5.5 wt%) and an ethylene glycol solution of germanium dioxide (germanium dioxide concentration of 1 wt%) were added to this polyester precursor. After adding 95 parts and 0.2 parts of diethylene glycol solution, it was sent to a polycondensation reactor. Polyester was obtained by reacting at 275 ° C. and 6.9 kPa in the polycondensation reactor 7, 280 ° C. and 0.7 kPa in the polycondensation reactor 8, and 284 ° C. and 0.2 kPa in the polycondensation reactor 9. The produced polyester was extracted in the form of a strand from the extraction port provided at the bottom of the polycondensation reactor 9 and cooled with water, and then cut into a chip to obtain a polyester chip.

  After the obtained polyester chip is crystallized with a stirring flow type crystallizer, it is dried at 140 ° C. under a nitrogen flow, then transferred to a packed column type solid phase polymerization tower and subjected to solid phase polymerization at 215 ° C. under a nitrogen flow. Chip-shaped polyethylene terephthalate was produced.

  2. The obtained polyethylene terephthalate chip was dried at 160 ° C. with a vacuum dryer, and then with an injection molding machine (M-100DM manufactured by Meiki Seisakusho Co., Ltd.), the cylinder temperature was 275 ° C., the screw rotation speed was 160 rpm, and the primary pressure time was 3. A cylindrical preform having an outer diameter of about 28 mm, an inner diameter of about 19 mm, a length of 136 mm, and a weight of about 56 g was injection molded at 0 seconds, a mold temperature of 10 ° C., and a cycle of 30 seconds.

Subsequently, only the portion corresponding to the bottle mouth portion of the preform was crystallized at 160 ° C. for 1 minute using a stopper crystallization apparatus (infrared heater). Thereafter, the preform surface temperature is preheated to about 110 ° C. with an infrared heater, stretch blow molding is performed with a blow molding machine set at a blow pressure of 5 to 40 kg / cm ² and a mold temperature of 150 ° C., and the average thickness of the body is 330 μm. A bottle with an internal volume of about 1.5 liters was molded. Table 3 shows the quality of the polyester and bottle after the solid phase polymerization.

[Example 11]
Polyester production In the polyester production facility shown in FIG. 1, 100 parts of terephthalic acid per unit time from one pipe and 45 parts of ethylene glycol from a distillate ethylene glycol storage tank 6 per unit time are continuously supplied to the slurry mixer 3. To provide a good slurry. On the other hand, the ethylene glycol is supplied to the esterification reactor A 4-1 in advance so that the ethylene glycol / terephthalic acid molar ratio in the esterification reactor becomes 1.4, and the esterification reaction is performed from the slurry mixer 3. The slurry was continuously supplied to the vessel A 4-1. Next, the slurry was esterified at 265 ° C. and normal pressure, and water produced as a by-product was taken out from the top of the rectification column to the outside of the esterification reactor to obtain a polyester precursor having an average degree of polymerization of 6. At this time, the amount of ethylene glycol taken out from the lower part of the rectifying column 5 to the outside of the esterification reaction apparatus was 1.3 parts per unit time. And the excess rectifying column lower part liquid was returned to esterification reactor A4-1 so that the liquid level of the lower part of a rectifying column might become constant constantly.

  After adding 0.0061 part of the solid material of the catalyst prepared in Example 6 to this polyester precursor, it was sent to a polycondensation reactor. Polyester was obtained by reacting at 275 ° C. and 6.9 kPa in the polycondensation reactor 7, 278 ° C. and 0.7 kPa in the polycondensation reactor 8, and 280 ° C. and 0.2 kPa in the polycondensation reactor 9. The produced polyester was extracted in the form of a strand from the extraction port provided at the bottom of the polycondensation reactor 9 and cooled with water, and then cut into a chip to obtain a polyester chip.

  After the obtained polyester chip is crystallized with a stirring flow type crystallizer, it is dried at 140 ° C. under a nitrogen flow, then transferred to a packed column type solid phase polymerization tower and subjected to solid phase polymerization at 215 ° C. under a nitrogen flow. Chip-shaped polyethylene terephthalate was produced.

  The obtained polyethylene terephthalate chip was dried at 160 ° C. with a vacuum dryer, and then cylinder temperature 275 ° C., screw rotation speed 160 rpm, primary pressure time 3. A cylindrical preform having an outer diameter of about 28 mm, an inner diameter of about 19 mm, a length of 136 mm, and a weight of about 56 g was injection molded at 0 seconds, a mold temperature of 10 ° C., and a cycle of 30 seconds.

Subsequently, only the portion corresponding to the bottle mouth portion of the preform was crystallized using a stopper crystallizing device (infrared heater) at 160 ° C. for 1 minute. Thereafter, the preform surface temperature is preheated to about 110 ° C. with an infrared heater, stretch blow molding is performed with a blow molding machine set at a blow pressure of 5 to 40 kg / cm ² and a mold temperature of 150 ° C., and the average thickness of the body is 330 μm. A bottle with an internal volume of about 1.5 liters was molded. Table 3 shows the quality of the polyester and bottle after the solid phase polymerization. In the polyester, the Ti element was 9 ppm and the P element was 11 ppm.

[Example 12]
Polyester production In the polyester production facility shown in FIG. 1, 100 parts of terephthalic acid per unit time from one pipe and 45 parts of ethylene glycol from a distillate ethylene glycol storage tank 6 per unit time are continuously supplied to the slurry mixer 3. To provide a good slurry. On the other hand, the ethylene glycol is supplied to the esterification reactor A 4-1 in advance so that the ethylene glycol / terephthalic acid molar ratio in the esterification reactor becomes 1.4, and the esterification reaction is performed from the slurry mixer 3. The slurry was continuously supplied to the vessel A 4-1. Next, the slurry was esterified at 265 ° C. and normal pressure, and water produced as a by-product was taken out from the top of the rectification column to the outside of the esterification reactor to obtain a polyester precursor having an average degree of polymerization of 6. At this time, the amount of ethylene glycol taken out from the lower part of the rectifying column 5 to the outside of the esterification reaction apparatus was 1.3 parts per unit time. And the excess rectifying column lower part liquid was returned to esterification reactor A4-1 so that the liquid level of the lower part of a rectifying column might become constant constantly.

  To this polyester precursor, 0.011 part of the catalyst solid prepared in Example 7 and 0.024 part of triethylphosphonoacetate were added, and then sent to a polycondensation reactor. The gram equivalent ratio (P / Ti) of phosphorus atoms to titanium atoms in this catalyst solid was 5.0. Subsequently, the reaction was carried out at 275 ° C. and 6.9 kPa in the polycondensation reactor 7, 278 ° C. and 0.7 kPa in the polycondensation reactor 8, and 280 ° C. and 0.2 kPa in the polycondensation reactor 9 to obtain a polyester. The produced polyester was extracted in the form of a strand from the extraction port provided at the bottom of the polycondensation reactor 9 and cooled with water, and then cut into a chip to obtain a polyester chip.

  After the obtained polyester chip is crystallized with a stirring flow type crystallizer, it is dried at 140 ° C. under a nitrogen flow, then transferred to a packed column type solid phase polymerization tower and subjected to solid phase polymerization at 215 ° C. under a nitrogen flow. Chip-shaped polyethylene terephthalate was produced.

  The obtained polyethylene terephthalate chip was dried at 160 ° C. with a vacuum dryer, and then cylinder temperature 275 ° C., screw rotation speed 160 rpm, primary pressure time 3. A cylindrical preform having an outer diameter of about 28 mm, an inner diameter of about 19 mm, a length of 136 mm, and a weight of about 56 g was injection molded at 0 seconds, a mold temperature of 10 ° C., and a cycle of 30 seconds.

Subsequently, only the portion corresponding to the bottle mouth portion of the preform was crystallized using a stopper crystallizing device (infrared heater) at 160 ° C. for 1 minute. Thereafter, the preform surface temperature is preheated to about 110 ° C. with an infrared heater, stretch blow molding is performed with a blow molding machine set at a blow pressure of 5 to 40 kg / cm ² and a mold temperature of 150 ° C., and the average thickness of the body is 330 μm. A bottle with an internal volume of about 1.5 liters was molded. Table 3 shows the quality of the polyester and bottle after the solid phase polymerization. In the polyester, the Ti element was 9 ppm and the P element was 29 ppm.

[Comparative Example 5]
In Example 8, the amount of ethylene glycol taken out from the lower part of the rectifying column A5-1 is 4.0 parts per unit time, and the excess rectifying column is set so that the liquid level in the lower part of the rectifying column is always constant. In order to return the lower liquid to the esterification reactor A 4-1, 4.0 parts of ethylene glycol from the lower part of the rectification column A 5-1 is returned to the esterification reactor A 4-1, and the rectification column A 5 is recovered. Polyester after solid phase polymerization in exactly the same way as in Example 6 except that the excess liquid in the rectifying column is taken out into the distilled ethylene glycol storage tank 6 so that the liquid level at the lower part of -1 is always constant. And a bottle was obtained. Table 3 shows the quality of the polyester and bottle after the solid phase polymerization.

[Comparative Example 6]
In Example 9, the amount of ethylene glycol taken out from the lower part of the rectifying column 5 is 1.3 parts per unit time, and the excess rectifying column lower liquid is added so that the liquid level in the lower part of the rectifying column is always constant. To return to the esterification reaction apparatus, 1.3 parts of ethylene glycol from the lower part of the rectification column 5 is returned to the esterification reaction apparatus, and the excess refinement is performed so that the liquid level in the lower part of the rectification column 5 is always constant. A polyester and a bottle after solid phase polymerization were obtained in exactly the same manner as in Example 7 except that the distillation column lower liquid was changed to take out into the distillation ethylene glycol storage tank. Table 3 shows the quality of the polyester and bottle after the solid phase polymerization.

  By the production method of the present invention, a polyester with little variation in quality such as intrinsic viscosity and color tone can be produced. Therefore, a polyester having desired physical properties can be produced stably for a long time, and its industrial significance is great.

It is a 1st conceptual diagram for enforcing the continuous manufacturing method of polyester of the present invention. It is a 2nd conceptual diagram for enforcing the continuous manufacturing method of polyester of this invention. It is a 3rd conceptual diagram for enforcing the continuous manufacturing method of polyester of this invention.

Explanation of symbols

1 terephthalic acid 2 ethylene glycol 3 slurry mixer 4-1 esterification reactor A
4-2 Esterification reactor B
5-1 Rectification tower A
5-2 Rectification tower B
6 Distilled ethylene glycol storage tank 7-9 Polycondensation reactor 10-12 Wet condenser 13-15 Circulating ethylene glycol storage tank 16 Ethylene glycol 17 Polyethylene terephthalate 18-1 Distilled ethylene glycol A
18-2 Distilled ethylene glycol B
19-1 Recovered ethylene glycol A
19-2 Recovered ethylene glycol B
20-1 Reaction product 20-2 Polyester precursor

Claims (6)

  A polyester precursor is formed by esterifying an aromatic dicarboxylic acid or an ester-forming derivative thereof and a diol compound in an esterification reactor equipped with an esterification reactor and a rectifying column, and then the polyester precursor. In a method for continuously producing a polyester by polycondensation of a product under reduced pressure, a molar ratio of a diol compound and an aromatic dicarboxylic acid or an ester-forming derivative thereof used for an esterification reaction (diol compound / aromatic dicarboxylic acid or its Ester-forming derivative) is 1.15 or more, and the component containing the diol compound is selected from the group consisting of water distilled into the rectification column, aromatic dicarboxylic acid or its ester-forming derivative, diol compound and polyester precursor The amount was continuously taken out of the esterification reactor and distilled to the rectification column. Rinomizu, aromatic dicarboxylic acid or an ester-forming derivative thereof, a method of continuous production polyester and returning from within the group consisting of diol compounds and polyester precursor components including a diol compound to the esterification reactor.   The method for continuously producing a polyester according to claim 1, wherein the aromatic dicarboxylic acid or its ester-forming derivative is terephthalic acid and the diol compound is ethylene glycol.   The method for continuously producing a polyester according to claim 1 or 2, wherein the degree of polymerization of the polyester precursor is 2 to 10. The polyester continuation according to any one of claims 1 to 3, wherein an amount W per unit time for taking out the diol compound from the rectifying column provided in the esterification reactor to the outside of the esterification reactor satisfies the following formula (1). Production method.
W ≦ W1- (Dp + 1) / Dp × (W2 / M2) × M1 (1)
[In the above formula, the amount of diol compound supplied to the esterification reactor per unit time is W1, the molecular weight is M1, the amount of aromatic dicarboxylic acid supplied to the esterification reactor per unit time is W2, and the molecular weight is M2. The polymerization degree of the polyester precursor is Dp. ] As a catalyst for polycondensation of a polyester precursor under reduced pressure, a titanium compound represented by the following general formula (I), or a titanium compound represented by the following general formula (I) and the following general formula (II) Selected from the group consisting of a titanium compound component containing at least one selected from the group consisting of a product obtained by reacting an aromatic polyvalent carboxylic acid or its anhydride, and a phosphorus compound represented by the following general formula (III) The method for continuously producing a polyester according to any one of claims 1 to 4, wherein the phosphorus compound containing at least one kind is used in a range where the gram equivalent ratio of phosphorus atom to titanium atom (P / Ti) is 1 to 15. .

[Wherein R ¹ , R ² , R ³ and R ⁴ are the same or different and each represents an alkyl group or a phenyl group, m represents an integer of 1 to 4, and m represents 2, 3 or 4] In this case, 2, 3 or 4 R ² and R ³ may be the same or different from each other. ]

[In the above formula, n represents an integer of 2 to 4. ]

[Wherein, R ⁵ , R ⁶ and R ⁷ are the same or different and each represents an alkyl group having 1 to 4 carbon atoms, X represents —CH ₂ — or —CH (Y) — (Y represents Represents a benzene ring). ] As a catalyst for polycondensation of a polyester precursor under reduced pressure, a titanium compound represented by the above general formula (I) and a phosphorus compound represented by the following general formula (IV) are expressed in gram equivalents of phosphorus atoms relative to titanium atoms. The continuous manufacturing method of the polyester of any one of Claims 1-4 using the deposit obtained by heating in glycol in ratio (P / Ti) used as the range which becomes 1-4.

[In the above formula, R ⁸ is an alkyl group having 2 to 18 carbon atoms or an aryl group having 6 to 20 carbon atoms, p is 1 or 2, and when p is 1, q is 0 or 1, and p is When 2, q is 0. ]

Images