JPH0639521B2 - Polyester manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a method for producing a polyester having ethylene terephthalate as a main repeating unit having highly improved electrostatic adhesion and good heat resistance and transparency. Is.

<Relationship with Prior Art> Saturated linear polyester typified by polyethylene terephthalate has excellent mechanical properties, heat resistance, weather resistance, electrical insulation, chemical resistance, etc.
It is widely used in a wide range of fields such as electrical applications and magnetic tapes. Usually, a polyester film is obtained by melt-extruding polyester and then biaxially stretching it. in this case,
In order to increase the uniformity of the film thickness and the casting speed, when the sheet-like material melt-extruded from the extrusion die is cooled on the surface of the rotary cooling drum, the adhesion between the sheet-like material and the drum surface must be enhanced. I have to. As a method for increasing the adhesion between the sheet-shaped material and the drum surface, a wire-shaped electrode is provided between the extrusion die and the rotating cooling drum to apply a high voltage, and static electricity is deposited on the upper surface of the unsolidified sheet-shaped material. It is known that a method of rapidly cooling the sheet while closely contacting the sheet with the surface of the cooling body (hereinafter referred to as electrostatic contact casting method) is effective.

Uniformity of film thickness is a very important property in film quality, and productivity of film is directly dependent on casting speed, so increasing casting speed is very important to improve productivity. ,
Great efforts have been made to improve electrostatic adhesion.

It is known that electrostatic adhesion is an effective means for increasing the amount of charges on the surface of the sheet-shaped material. Further, in order to increase the amount of charges on the surface of the sheet material in the electrostatic contact casting method, it is known that it is effective to modify the polyester raw material used in the film formation of the polyester film to reduce its specific resistance. ing.

The present inventors have already reduced the specific resistance of the polyester raw material by adding a Mg compound, an alkali metal compound, and a P compound in a specific amount ratio during a specific period of the polyester manufacturing process, thereby achieving high electrostatic adhesion. It proposes a method that can be given. Certainly, these methods are effective means for imparting electrostatic adhesion, but in order to achieve a high level of electrostatic adhesion, the atomic ratio of the Mg compound and the P compound (hereinafter, Mg / It is necessary to increase the P ratio).
Increasing the Mg / P ratio is an extremely effective means for improving electrostatic adhesion, but on the other hand, the thermal stability of polyester decreases in proportion to the Mg / P ratio, so high electrostatic adhesion In order to secure the above, it is necessary to allow a decrease in thermal stability to some extent.

However, when the heat resistance of the polyester is deteriorated, it becomes difficult to melt and reuse the edge portion of the film generated in the stretching step and the nonstandard film, which is not preferable.

<Purpose of the Invention> The present invention aims to provide a polyester in which the above-mentioned drawbacks are improved, electrostatic adhesion is highly improved, and the main repeating unit having good heat resistance and transparency is ethylene terephthalate. The manufacturing method is as follows.

<Structure of the Invention> In the present invention, when a polyester having ethylene terephthalate as a main repeating unit is produced, the following (I) to (III) may be used at any stage until the completion of the initial condensation reaction.
The amount of Mg compound and Co compound satisfying the formula at the same time is added, and the amount of P compound satisfying the formula (IV) below is divided into two or more times, and the initial addition amount is 50% of the total amount of P compound. It is a method for producing a polyester characterized in that it is less than mol%.

30 ≦ Mg ≦ 400 (I) 3.0 ≦ Co ≦ 50 (ii) 4.0 ≦ Mg / Co ≦ 150 (III) 0.8 ≦ (Mg + Co) / P ≦ 10 (IV) [In the formula, Mg is the amount of Mg compound added to the polyester as Mg atom (ppm), Co is the amount of Co compound added to the polyester as Co atom (ppm), and P is the residual content of phosphorus compound as P atom to the polyester (pp).
m), Mg / Co and (Mg + Co) / P represent atomic ratios. In the present invention, it is preferable to add at least one alkali metal compound selected from Na and K compounds in an amount satisfying the following formula (V) at any stage until the completion of the initial condensation reaction.

3 ≦ M ₁ ≦ 50 (V) [wherein, M ₁ represents the addition amount (ppm) as a metal atom to the polyester of at least one alkali metal compound selected from Na and K compounds. Further, in the present invention, at least one kind of alkaline earth selected from Ca, Sr and Ba compounds in an amount which simultaneously satisfies the following formulas (VI) to (VIII) at any stage until the completion of the initial condensation reaction. A metal compound and a P compound may be added.

30 ≦ Mg + M ₂ ≦ 400 …… (VI) 2 ≦ Mg / M ₂ ≦ 100 …… (VII) 0.8 ≦ (Mg + Co + M ₂ ) / P …… (VIII) [In the formula, Mg is the Mg atom for the polyester of the Mg compound] (Ppm) as a metal atom, M ₂ as a metal atom to the polyester of at least one alkaline earth metal compound selected from compounds of Ca, Sr and Ba (pp)
m) and P are residual contents (ppm) as P atoms of the phosphorus compound to the polyester, Mg / M ₂ and (Mg + Co + M
₂ ) / P indicates the atomic number ratio. The polyester of the present invention is one in which 80 mol% or more of its repeating unit is composed of ethylene terephthalate, and as other friendly polymerization components, isophthalic acid, P-β-oxyethoxybenzoic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-
Dicarboxyl diphenyl, 4,4'-dicarboxyl benzophenone, bis (4-carboxyl phenyl)
Examples thereof include dicarboxylic acid components such as ethane, adipic acid, sepacic acid, and 5-sodium sulfoisophthalic acid. As the glycol component, propylene glycol, butanediol, neopentyl glycol, diethylene glycol, cyclohexanedimethanol, an ethylene oxide adduct of bisphenol A, or the like can be arbitrarily selected and used. In addition, a small amount of amide bond, urethane bond, ether bond, carbonate bond, etc. may be contained as a copolymerization component.

Mg compound, Co compound, Na compound, K used in the present invention
Any compound, Ca compound, Sr compound and Ba compound can be used as long as it is soluble in the reaction system. Examples of Mg compounds include lower fatty acid salts such as magnesium hydride, magnesium oxide and magnesium acetate, and alkoxides such as magnesium methoxide.

Examples of the Co compound include lower fatty acid salts such as cobalt acetate, cobalt naphthalate, cobalt benzoate, cobalt chloride and cobalt acetylacetonate.

Examples of the Na compound and the K compound include carboxylates, phosphates, carbonates, hydrides and alkoxides of Na and K, and specifically, sodium acetate, potassium acetate, sodium benzoate, potassium benzoate, phosphoric acid. Sodium dihydrogen, potassium dihydrogen phosphate, sodium pyrophosphate, potassium pyrophosphate, sodium tripolyphosphate, potassium tripolyphosphate, sodium bicarbonate, potassium bicarbonate, sodium hydride, potassium hydride, sodium methoxide, potassium methoxide, Examples include sodium ethoxide and potassium ethoxide. These compounds may be used alone or in combination of two or more.

Examples of Ca compounds, Sr compounds and Ba compounds include hydrides such as calcium hydride, strontium hydride and barium hydride, hydroxides such as calcium hydroxide, lower grades such as calcium acetate, strontium acetate and barium acetate. Examples include fatty acid salts, calcium methoxide, strontium methoxide, and alkoxides such as barium methoxide. These alkaline earth metal compounds may be used alone or in combination of two or more.

Examples of the P compound used in the present invention include phosphoric acid, phosphorous acid, phosphonic acid and derivatives thereof, and specific examples include phosphoric acid, phosphoric acid trimethyl ester, phosphoric acid triethyl ester, phosphoric acid tributyl ester, Phosphoric acid triphenyl ester, phosphoric acid monomethyl ester, phosphoric acid dimethyl ester, phosphoric acid monobutyl ester, phosphoric acid dibutyl ester, phosphorous acid, phosphorous acid trimethyl ester, phosphorous acid triethyl ester, phosphorous acid tributyl ester, methylphosphon Acid, methyl phosphonic acid dimethyl ester, ethyl phosphonic acid dimethyl ester, phenyl phosphonic acid dimethyl ester, phenyl phosphonic acid diethyl ester, phenyl phosphonic acid diphenyl ester, etc., these may be used alone, It may be used in combination with more species. The use of phosphoric acid, phosphorous acid and their ester derivatives is particularly preferred.

A feature of the present invention is that a specific amount ratio of an alkaline earth metal compound,
It is to add an alkali metal compound, a cobalt compound and a P compound at a specific time. In particular, divide the P compound into two or more parts and add it to the polyester manufacturing process.
A major feature is that a specific amount of Co compound is used in combination with the compound. By satisfying such limited conditions, it is possible to obtain high transparency for the first time, and even if the metal / P ratio is lowered, a high degree of electrostatic adhesion can be obtained. It is possible to impart excellent electrostatic adhesion.

The amount of Mg compound added is Mg as an alkaline earth metal compound.
When the compound alone is carried out, as shown by the formula (I), 30 to 400 ppm of Ca as a metal atom relative to the produced polyester, Ca
When another alkaline earth metal compound such as a compound is used in combination, the total amount of the alkaline earth metal compound is 30 as a metal atom to the produced polyester as shown in the formula (VI).
It is necessary to be in the range of to 400 ppm, and the range of 50 to 300 ppm is particularly preferable. If it is less than 30 ppm, the specific resistance of the obtained polyester raw material is not significantly reduced, and as a result, the improvement in electrostatic adhesion cannot be satisfied, which is not preferable. On the other hand, if it exceeds 400ppm, the improvement of electrostatic adhesion will reach the ceiling and
It is not preferable because it causes quality deterioration such as increase of by-product amount and deterioration of heat resistance of polyester.

When another alkaline earth metal compound such as a Ca compound is used in combination, the addition amount of the Mg compound to the total amount of the alkaline earth metal compounds other than the Mg compound is represented by the formula (VII), and the atomic ratio of the metal is Should be in the range of 2-100. Especially preferably, it is in the range of 5 to 50. If the molar ratio of the metal is out of the range of 2 to 100, the combined effect of the metals with respect to the electrostatic adhesion improving effect is reduced, which is not preferable.
If it is less than 2, there is a problem in that the particles that are precipitated in the polyester manufacturing process, so-called internal particles, are increased and the transparency of the film is lowered.

The timing of adding these alkaline earth metal compounds to the polyester manufacturing process can be appropriately selected at any stage until the initial condensation reaction is completed, but the optimum timing of addition depends on the manufacturing process and the type of compound. For example, when produced by the direct polymerization method, the Mg compound has a high esterification rate.
It is preferable to add it at a time point of 20 to 80%, particularly preferably at a time point of 50 to 70%. Addition of a Mg compound outside this range is not preferable because the oligomer's transitory property is reduced and insoluble foreign matter in the oligomer cannot be removed excessively better. That is, since the oligomericity is reduced,
In order to remove the insoluble foreign matter in the oligomer, it is necessary to increase the filter excess area or increase the filter replacement frequency, which is economically disadvantageous. On the other hand, if polyester is produced without excess of oligomer, the clarity of the obtained polyester is lowered and product defects such as fish eyes are increased, which is not preferable. Similarly, when manufacturing by the direct polymerization method,
The Ca compound, Sr compound and Ba compound are preferably added after the esterification reaction is completed. If it is added before the completion of the esterification reaction, the amount of internal particles produced will increase and the transparency will decrease, such being undesirable.

Further, in the case of producing by the transesterification method, if all the metal compounds are added before the transesterification reaction, the catalytic activity for the transesterification reaction is too strong and it becomes difficult to control the transesterification reaction. It is preferably added after the transesterification reaction. In addition, Zn compounds and
The transesterification reaction may be carried out using a metal compound such as an Mn compound, and all the metal compounds may be added after the completion of the transesterification reaction.

The intrinsic viscosity was about 0.2 when the initial condensation reaction was completed.
After that, the viscosity of the reaction system is too high, and the mixing of the additive components becomes uneven, making it impossible to obtain a homogeneous product, and depolymerization of the oligomer occurs, resulting in a decrease in productivity. Since this causes an increase in the amount of by-products and DEG, it is necessary to add the metal compound at least before the completion of the initial condensation reaction.

The amount of the Co compound added is 3.0 to 50 p as a metal atom relative to the produced polyester as shown by the formulas (II) and (III).
It is necessary to set the atomic ratio of Mg / Co in the range of 4 to 150 in pm. Particularly preferably, the addition amount as metal atoms is in the range of 5.0 to 30 ppm and the atomic ratio of Mg / Co is in the range of 7 to 100. The electrostatic adhesion is remarkably improved for the first time by adding the Co compound in the above range.

The addition of the Co compound to the reaction system can be appropriately selected at any stage until the completion of the initial condensation reaction. Also,
If the above conditions are satisfied, they may be added alone or may be added simultaneously with other additives. The method of adding simultaneously with other additives is particularly preferable because it can reduce the number of reaction tanks when carrying out by a continuous method.

The addition amount of the alkali metal compound is 3 to 50 pp as metal atom with respect to the produced polyester as shown by the general formula (V).
A range of m, particularly 5 to 30 ppm is preferable. Only when added in this range, a high degree of electrostatic adhesion is imparted. If the addition amount of the alkali metal compound is less than 3 ppm, the electrostatic adhesion is lowered and the amount of DEG by-product is greatly increased, which is not preferable. On the other hand, if it exceeds 50 ppm, not only the electrostatic adhesion is deteriorated, but also coarse particles are increased, the heat resistance is deteriorated, and the resin color is deteriorated.

The addition of these alkali metal compounds to the reaction system can be appropriately selected at any stage until the completion of the initial condensation reaction. The addition of these alkali metal compounds to the reaction system may be carried out alone if the above conditions are satisfied,
It may be performed at the same time as other additives. The method of adding simultaneously with other additives is particularly preferable because the number of reaction tanks can be reduced when carrying out by a continuous method.

The addition amount of the P compound is, as shown by the general formulas (IV) and (VIII), as an atomic ratio of the total metal atoms of the total alkaline earth metal compound and the Co compound to the P atom of the P compound.
Must be in the range 8-10. The range of 1.0 to 3.0 is particularly preferable. If it is less than 0.8, the electrostatic adhesion is deteriorated, which is not preferable. On the other hand, if it exceeds 10, heat resistance and resin color deteriorate, which is not preferable.

Further, the addition of the P compound needs to be performed twice or more in a divided manner. Only when the P compound is added in two or more divided portions, the effect of improving the electrostatic adhesion by the combined use of the Co compound appears remarkably.

The P compound can be added in divided portions by shifting the addition time when it is carried out in a batch system, or by changing the place of addition when it is carried out in a continuous system. When it is carried out in a continuous manner, it can be carried out by increasing the number of reaction cans, but since the equipment cost is high, it is preferable to divide the inside of the reaction can and add it to each divided part. Further, a method of line mixing in the reaction can and the continuous part of the reaction can may be adopted.

The number of divisions is not particularly limited as long as it is two or more. However, if the number of divisions is increased, the addition program becomes complicated when the batch method is used, and the manufacturing apparatus becomes complicated when the continuous method is used. It is particularly preferable to divide into two times because the equipment cost becomes high.

As for the division ratio of the addition amount of the P compound, the addition amount added at the first time is preferably 50% or less of the total addition amount, and particularly preferably 30% or less. By carrying out at such a division ratio, the effect of division and addition is more remarkably exhibited.

Regarding the timing of adding the P compound, it is preferable that the second and subsequent additions be performed after the addition of the Mg compound. According to this aspect, the effect of dividing and adding the P compound is more remarkably exhibited. The addition timing of the first P compound is not particularly limited,
It may be before, at the same time as, or after the Mg compound. The first addition of the P compound may be carried out before the completion of the esterification and transesterification reactions,
Although it may be added after the completion, it is preferable to add the second and subsequent P compounds after the completion of the esterification and transesterification reaction.

By selecting the limited conditions as described above, metal / P
The reason why a high ratio of electrostatic adhesion can be imparted even if the ratio is lowered is unknown, but by satisfying the above requirements, Mg compounds, Co compounds, alkaline earth metal compounds other than Mg compounds, alkali metals It is considered that this is caused by an increase in the concentration of the conductive compound produced by the reaction of the compound, the P compound and the oligomer.

The additive may be added in either solid or liquid form, but it is most preferably added as an ethylene glycol solution from the viewpoint of supply accuracy. When it is added in a solid state, it is preferable to add it to the reaction system after enclosing it in a polyester container.

In addition, the temperature of the reaction system when adding these additives,
There is no particular limitation, but a range of less than 290 ° C, particularly 270 ° C or less is preferable. If it exceeds 290 ° C, side reactions such as an increase in the amount of DEG by-product and coloration are accelerated, which is not preferable.

The pressure of the reaction system at the time of adding the above additives is from normal pressure to 3 kg.
/ Cm ² is preferable, and atmospheric pressure to 1 kg / cm ^{2 is} particularly preferable.
Addition under reduced pressure is not preferable because the additive escapes. On the contrary, if it exceeds 3 kg / cm ² , the amount of DEG by-product increases, which is not preferable.

The present invention can be applied to both the transesterification method and the direct polymerization method. Further, either a batch system or a continuous system may be adopted. In the case of carrying out the transesterification method, there is no particular limitation on the transesterification catalyst, and any conventionally known one can be used. For example, the above alkaline earth metal compound or Co compound may be used, or the Zn compound or Mn compound may be used. When the alkaline earth metal compound is used, a part of the total addition amount may be used as a transesterification catalyst, and the remaining amount may be added after the completion of the transesterification reaction. Further, these transesterification catalysts may be used in combination of two or more kinds.

When the direct polymerization method is used, the use of amines, quaternary ammonium salts, and the like as the DEG generation inhibitor is not limited. The polycondensation catalyst is not subject to any particular restriction, but it is preferable to appropriately select and use from among Sb compounds, Ge compounds and Ti compounds.

Further, in the present invention, a transesterification, esterification and polycondensation reaction may be carried out by adding a lubricant composed of inorganic or organic fine particles.

<Effect of the Invention> When a polyester film is produced using the polyester raw material obtained by the production method according to the present invention as described above, the electrostatic adhesion of the polyester raw material is extremely good, and the heat resistance of the polymer and The effect that the transparency of the film is good.

<Example> Next, the Example and comparative example of this invention are shown. All parts in the examples mean parts by weight unless otherwise specified.

The measuring method used is shown below.

(1) Esterification rate Determined from the amount of carboxyl groups remaining in the reaction product and the saponification value of the reaction product.

(2) Intrinsic viscosity The polymer is dissolved in a mixed solvent of phenol (6 parts by weight) and tetrachloroethane (4 parts by weight) and measured at 30 ° C.

(3) Melt specific resistance of polymer Put two electrode plates in polyester melted at 275 ℃, measure the current value (io) when a voltage of 120V is applied, and calculate the specific resistance value (fi) by the following formula. Ask by.

A = Electrode area (cm ² ), = Electrode distance (cm) V = Voltage (V) (4) Electrostatic adhesion A tungsten wire electrode is provided between the die of the extruder and the cooling drum. Casting is performed by applying a voltage of 10 to 15 KV between the casting drum and the casting drum, and the surface of the obtained casting raw fabric is observed with the naked eye to evaluate the casting speed at which binar bubbles start to occur. The higher the casting speed, the better the electrostatic adhesion.

(5) Heat resistance of polymer The polymer is sealed in a glass ampoule under a reduced pressure of nitrogen of 100 mmHg, and the change in intrinsic viscosity when heat-treated at 300 ° C for 4 hours is measured. Heat resistance is the decrease in intrinsic viscosity due to heat treatment (△
It is displayed as IV).

The smaller the ΔIV, the better the heat resistance.

(6) Film haze Measured with a direct reading haze meter (manufactured by Toyo Seiki Co., Ltd.).

Example 1 A first S-reaction reactor equipped with a stirrer, a partial condenser, a raw material inlet and a product outlet, the inside of a reaction vessel was divided into two tanks, and each reactor was equipped with an agitator to perform partial condensation. A three-stage complete mixing tank type continuous esterification reaction device comprising a second esterification reaction device provided with a vessel, a raw material charging port and a product outlet port was used. An EG slurry of TPA adjusted to a molar ratio of EG to TPA of 1.7 was continuously supplied to the system in which the esterification reaction product of the first esterification reaction vessel was present. At the same time, an EG solution of magnesium acetate tetrahydrate is passed through the reaction port from a supply port other than the TPA EG slurry supply port.
It was continuously supplied so as to be 120 ppm as Mg atoms, and the reaction was carried out at an atmospheric pressure and an average residence time of 4.5 hours at a temperature of 255 ° C.

This reaction product was continuously taken out of the system, supplied to the first tank of the second esterification reaction can, and continuously taken out from the second tank. The overflow system was used for the transfer from the first tank to the second tank.

250 parts by weight of 0.9 parts by weight of EG and Sb atoms per polyester unit of the reaction product passing through the reactor.
An EG solution of antimony trioxide in an amount of m and an EG solution of trimethyl phosphate in an amount of 41 ppm as P atoms are placed in the first tank, and an amount of cobalt acetate tetrahydrate is adjusted to be 30 ppm as Co atoms. EG solution of salt and P
An EG solution of trimethyl phosphate in an amount of 99 ppm as an atom was continuously supplied to the second tank and reacted at atmospheric pressure for various average residence times of 2.5 hours and at a temperature of 260 ° C.

The esterification rate of the reaction product of the first esterification reaction can is 70.
%, And the esterification rate of the reaction product of the second esterification reaction can was 98%.

The esterification reaction product was continuously filtered through a filter made of stainless steel with a mesh of 400 mesh and then a two-stage continuous polycondensation reaction provided with a stirrer, a partial condenser, a raw material charging port and a product outlet port. Polyester was continuously supplied to the apparatus to carry out polycondensation to obtain a polyester having an intrinsic viscosity of 0.620. The quality of this polymer and the film of 12μ film obtained by melt extruding the polymer at 290 ° C., stretching 3.5 times in the longitudinal direction at 90 ° C., stretching 3.5 times in the transverse direction at 130 ° C., and then heat treating at 220 ° C. The haze is shown in Table 1.

As is clear from Table 1, the polyester obtained in this example has extremely high electrostatic adhesion, excellent transparency and heat resistance, and is of extremely high quality.

Comparative Example 1 Obtained by the same method as in Example 1 except that cobalt acetate tetrahydrate was removed from the method of Example 1 and the amount of trimethyl phosphate added was reduced to a metal / P ratio of 1.5. The polymer quality and film haze are shown in Table 1. It can be seen that the method of this comparative example is significantly inferior in electrostatic adhesion to Example 1.

Comparative Example 2 Example 1 except that the addition of magnesium acetate tetrahydrate was discontinued in the method of Example 1 and the amount of trimethyl phosphate added was reduced to a metal / P ratio of 1.5.
The polymer quality and film haze obtained in the same manner as in Table 1 are shown in Table 1. The method of this comparative example is extremely inferior in electrostatic adhesion.

Comparative Example 3 The polymer quality and the haze of the film obtained by the same method as in Example 1 are shown in Table 1 except that the amount of trimethyl phosphate added in the method of Example 1 was increased to a metal / P ratio of 0.5. It was The method of this comparative example is extremely inferior in electrostatic adhesion.

Comparative Example 4 Table 1 shows the quality of the polymer and the haze of the film obtained by the same method as in Example 1 except that the addition of trimethyl phosphate was all discontinued in the method of Example 1.
It can be seen that the method of this comparative example is inferior in electrostatic adhesion and heat resistance to that of Example 1 and is of low quality.

Comparative Examples 5-6 In the method of Example 1, the first of the second esterification reaction tank
The same method as in Example 1 except that the addition of trimethyl phosphate added separately to the second tank and the second tank is changed so that the total amount is collectively added to the first tank and the second tank, respectively. Table 1 shows the quality of the polymer obtained in Example 1 and the haze of the film. It can be seen that the electrostatic adhesion properties of these comparative examples are significantly inferior to those of Example 1.

Example 2 Table 1 shows the results when magnesium acetate tetrahydrate, cobalt acetate tetrahydrate and sodium acetate were used as the metal compound and triethyl phosphate was used as the P compound in the same manner as in Example 1.

As is clear from Table 1, the polymers and films obtained by the method of this example have extremely high quality.

Comparative Example 7 Example 2 was repeated except that in the method of Example 2, the addition of cobalt acetate tetrahydrate was discontinued and the amount of triethyl phosphate added was reduced to a metal / P ratio of 1.6.
The polymer quality and film haze obtained in the same manner as in Table 1 are shown in Table 1.

The method of this comparative example is inferior in electrostatic adhesion to Example 2.

Comparative Example 8 In the method of Example 2, the amount of sodium acetate added was 10
The quality of the polymer and the haze of the film obtained in the same manner as in Example 2 except for increasing to 0 ppm are shown in Table 1.

It can be seen that the method of this comparative example is inferior in electrostatic adhesion, heat resistance and transparency to that of Example 2 and is of low quality.

Comparative Example 9 In the method of Example 2, the amount of cobalt acetate tetrahydrate added was changed.
Example 1 except that the amount of trimethyl phosphate added was increased to 100 ppm and the metal / P ratio was increased to 1.6.
The polymer quality and film haze obtained in the same manner as in Table 1 are shown in Table 1.

The method of this comparative example is inferior in electrostatic adhesion and heat resistance as compared with Example 2.

Example 3 In the same manner as in Example 1, Table 1 shows the results when magnesium acetate tetrahydrate, cobalt acetate tetrahydrate and sodium acetate were used as the metal compounds and phosphoric acid was used as the P compound.

As is clear from Table 1, the polymers and films obtained by the method of this example have extremely high quality.

Example 4 In the same manner as in Example 1, the results of using magnesium acetate tetrahydrate, cobalt acetate tetrahydrate, calcium acetate-hydrate and sodium acetate as the metal compound and trimethyl phosphate as the P compound were obtained. The results are shown in Table 1.

As is clear from Table 1, the polymers and films obtained by the method of this example have extremely high quality.

Comparative Example 10 Obtained by the same method as in Example 4, except that the addition of cobalt acetate tetrahydrate was discontinued in the method of Example 4 and the amount of trimethyl phosphate added was reduced to a metal / P ratio of 1.4. The polymer quality and film haze are shown in Table 1.

The method of this comparative example is inferior in electrostatic adhesion to Example 4.

Example 5 Table 1 shows the results in the same manner as in Example 1 except that magnesium acetate tetrahydrate, cobalt acetate tetrahydrate, strontium acetate and sodium acetate were used as the metal compounds, and triethyl phosphate was used as the P compound. It was

It can be seen that the polymers and films obtained by the method of this example are of very high quality.

Example 6 Table 1 shows the results in the same manner as in Example 1 except that magnesium acetate tetrahydrate, cobalt acetate tetrahydrate, barium acetate and sodium acetate were used as the metal compounds, and triethyl phosphate was used as the P compound. It was

It can be seen that the polymers and films obtained by the method of this example are of very high quality.

Example 7 Using a continuous esterification reaction device consisting of a two-stage complete mixing tank equipped with a stirrer, a dephlegmator, a raw material charging port and a product outlet, the esterification reaction production of the first esterification reaction vessel was performed. An EG slurry of TPA having a molar ratio of EG to TPA of 1.7 and an antimony trioxide Sb atom content of 289 ppm per TPA unit was continuously fed to the system in which the product was present. Average residence time at atmospheric pressure 4.5 hours, temperature 2
The reaction was carried out at 55 ° C.

This reaction product was continuously taken out of the system and supplied to the second esterification reaction can. Furthermore, EG was charged and 0.5 part by weight per polyester unit was continuously added, and the mixture was reacted at atmospheric pressure with an average residence time of 5.0 hours and a temperature of 260 ° C. The esterification rate of the reaction product in the first esterification reactor is 70%
And the esterification rate of the reaction product of the second esterification reaction can was 98%. 1144 parts of the esterification reaction product (corresponding to 1100 parts of ethylene terephthalate unit) and 70 parts of EG were charged into a batch-type polycondensation reaction can, and the temperature was set to 260 ° C.
Heat and stir at normal pressure for 30 minutes, and at the same temperature and pressure, 50 g / concentration of magnesium acetate tetrahydrate in EG solution 19.41 parts by volume (100 ppm in terms of Mg atom based on the produced polyester) and 20 g / concentration of acetic acid. EG solution of cobalt tetrahydrate 4.65
Capacity part (20 pp in terms of Co atom to the produced polyester)
m) was added and the mixture was heated with stirring for 30 minutes. Then, at the same temperature and pressure, trimethyl phosphate EG with a concentration of 130 g /
1.03 parts by volume of the solution (27 ppm in terms of P atom based on the produced polyester) was added, and the mixture was heated and stirred for 15 minutes. Then, at the same temperature and pressure, EG of sodium acetate at a concentration of 50 g /
1.56 parts by volume of the solution (20 ppm in terms of Na atom to the produced polyester) and 3.29 parts by volume of EG solution of trimethyl phosphate having a concentration of 130 g / (86 ppm in terms of P atom to the produced polyester) were added, and the mixture was heated and stirred for 15 minutes. . About 1
After increasing the reaction temperature to 290 ° C in 00 minutes and gradually lowering the pressure of the reaction system to 0.5 mmHg, polycondensation reaction was performed at 290 ° C and 0.5 mmHg for about 100 minutes to obtain a polymer with an intrinsic viscosity of 0.620. Got Table 2 shows the quality of this polymer and the film haze of the film obtained by forming the polymer by the method described in Example 1.

As is clear from Table 2, the polyester obtained in this example has extremely high electrostatic adhesion, excellent transparency and heat resistance, and is of good quality.

Comparative Example 11 In the method of Example 7, the addition of cobalt acetate tetrahydrate was stopped and the amount of triethyl phosphate added was adjusted to 25 pp.
Polymer quality and film haze obtained by the same method as in Example 7 except that m and 80 ppm are shown in Table 2. The polyester obtained in this comparative example is inferior in electrostatic adhesion to Example 7.

Example 8 1000 parts of dimethyl terephthalate and EG800 in a polymerization reactor
And 0.70 part of magnesium acetate tetrahydrate (80 ppm added to the produced polyester in terms of Mg atom) were charged and heated at 195 ° C. for about 4 hours in a nitrogen atmosphere to carry out a transesterification reaction. As the transesterification reaction proceeded, the reaction temperature was raised and finally raised to 240 ° C. At the same temperature, 31.67 parts by volume of an antimony trioxide EG solution having a concentration of 12 g / g and 0.36 parts by volume of an EG solution of sodium acetate having a concentration of 50 g / g were added to the transesterification product (Na for the produced polyester).
0.79 parts by volume of an EG solution of trimethyl phosphate having a concentration of 5 ppm) and a concentration of 130 g / (23 ppm in terms of P atom based on the produced polyester) were added, and the mixture was heated and stirred for 20 minutes. Next, 2.55 parts by volume of a trimethyl phosphate EG solution having a concentration of 130 g / at the same temperature and the same pressure (74 ppm in terms of P atom to the produced polyester) was added, and the mixture was heated and stirred at the same temperature and the same pressure for 10 minutes. Further, 6.27 parts by volume of an EG solution of cobalt acetate tetrahydrate having a concentration of 20 g / (30 ppm in terms of Co atom to the produced polyester) was added, and the mixture was heated and stirred at the same temperature and pressure for 15 minutes, and then 40 minutes were required. The temperature of the reaction system was lowered to 0.05 mmHg while raising the temperature to 290 ° C.
When polycondensation is performed for about 80 minutes under the same pressure, the intrinsic viscosity is 0.620.
A polymer of Table 3 shows the quality of this polymer and the haze of the film obtained by forming the polymer by the method described in Example 1.

It can be seen that the polyester obtained in this example has high electrostatic adhesion, transparency and heat resistance, and high quality.

Comparative Example 12 In the method of Example 8, the addition of cobalt acetate tetrahydrate was stopped and the addition of trimethyl phosphate was changed to 20 ppm.
Table 3 shows the quality of the polymer and the haze of the film, which were obtained by the same method as in Example 8 except that the values were 64 ppm and 64 ppm.

The polyester obtained in this comparative example is inferior in electrostatic adhesion to Example 8.

Comparative Example 13 The procedure of Example 1 was repeated except that the amounts of the P compound added to the first tank for the first esterification reaction vessel and the second tank for the second esterification reaction vessel in the second tank were reversed.

Claims (1)

[Claims] 1. When producing a polyester having ethylene terephthalate as a main repeating unit, any of the following (I) to (II) at any stage until the completion of the initial condensation reaction is carried out.
Formula (I) is added simultaneously with an amount of Mg compound and Co compound, and the amount of P compound satisfying the following formula (IV) is divided into two or more times, and the initial addition amount is the total amount of P compound. Of less than 50 mol% of the polyester. 30 ≦ Mg ≦ 400 (I) 3.0 ≦ Co ≦ 50 (II) 4.0 ≦ Mg / Co ≦ 150 (III) 0.8 ≦ (Mg + Co) / P ≦ 10 (IV) [In the formula, Mg is the amount of Mg compound added to the polyester as Mg atom (ppm), Co is the amount of Co compound added to the polyester as Co atom (ppm), and P is the residual content of phosphorus compound as P atom to the polyester (pp).
m), Mg / Co and (Mg + Co) / P represent atomic ratios. ]