JP5132271B2 - Method for producing flame retardant polyester polymer - Google Patents

Description

  The present invention relates to a method for producing a polyester polymer, a polymer produced by the method, and a fiber produced from the polymer, and more specifically, a phosphorus-based flame retardant is converted to a polyester in terms of phosphorus atoms. Flame retardant polyester polymerization in which a polymer is introduced into the second esterification reaction stage, and manganese salt and phosphorus compound as UV stabilizers are added in an amount of 0.1 to 500 ppm in terms of manganese atom and phosphorus atom, respectively. The present invention relates to a method for producing a product, a polymer produced thereby, and a fiber produced therefrom.

  In general, polyester, particularly polyethylene terephthalate (hereinafter referred to as “PET”) has excellent mechanical properties and chemical properties such as chemical resistance, and is widely used for fibers, films, engineering plastics, and the like. However, such a conventional polyester has a drawback that it easily burns. In recent years, legal regulations have become stricter in the clothing field such as infant clothes and in the field of industrial goods such as car seats, curtains, and carpets for automobiles, and the demand for flame retardant fibers has increased for the purpose of fire prevention. Yes.

  Examples of methods for imparting flame retardancy to polyester fibers include a first method in which a flame retardant is treated on the surface of the fiber, a second method in which a flame retardant is added during spinning, and a method in which spinning is performed. There is a third method in which a flammable substance is added and copolymerized. The first method is advantageous in terms of manufacturing cost, but has a problem in durability. The second method includes a method of mixing and spinning a substance exhibiting flame retardancy (a flame retardant) and a method of blending and spinning a flame retardant master batch containing an excessive amount of a flame retardant. The former has a problem that spinnability and physical properties of the raw yarn are lowered, and the latter has difficulty in producing a polymer having physical properties such as desired viscosity and hue by using a flame retardant masterbatch. is there. The third method is advantageous in terms of durability of flame retardancy and has an advantage that it is similar to a normal polyester production process. For the production of flame retardant polyester by copolymerization, which is the third method, halogen flame retardants (particularly bromine (Br) flame retardants) and phosphorus (P) flame retardants are mainly used.

  Patents using brominated flame retardants include Patent Document 1, Patent Document 2, Patent Document 3 and the like. However, in order to obtain effective flame retardancy, brominated compounds are easily pyrolyzed at high temperatures. A large amount of flame retardant must be added. As a result, when a brominated flame retardant is used, there is a problem that the hue and light resistance of the polymer are lowered, and a toxic gas is generated during combustion.

Patents using phosphorus-based flame retardants include Patent Document 4, Patent Document 5, Patent Document 6, Patent Document 7, and Patent Document 8, and the present inventors conducted tests as described in these patents. As a result, it was confirmed that the flame-retardant polyester has a great decrease in physical properties due to UV. Further, in the case of PET polymerization used in most cases, if dimethyl terephthalate (hereinafter referred to as “DMT”) is used as a raw material, the cost increase compared to the polymerization method using terephthalic acid (hereinafter referred to as “TPA”). Has the disadvantage of being large.
JP 62-6912 A JP-A-53-46398 Japanese Patent Laid-Open No. 51-28894 US Pat. No. 3,941,752 US Pat. No. 5,399,428 US Pat. No. 5,180,793 Japanese Patent Laid-Open No. 50-56488 JP 52-47891 A

  Therefore, the present invention is for solving the above-mentioned problems of the prior art, and the object is to have permanent flame retardancy and particularly excellent stability to UV (ultraviolet rays). Another object of the present invention is to provide a method for producing a polyester polymer and a fiber.

  Another object of the present invention is to provide a polyester polymer produced by the method for producing a flame-retardant polyester polymer, and a fiber produced therefrom.

In order to achieve the above object, according to one aspect of the present invention, a slurry of terephthalic acid (TPA) and ethylene glycol (EG) as reaction raw materials in a method for producing a flame-retardant polyester polymer using a terephthalic acid method A first esterification reaction stage in which the slurry is charged into a first esterification reaction tank to produce an oligomer, and the oligomer produced in the first esterification reaction stage is a second esterification reaction tank The phosphorus-based flame retardant represented by the following chemical formula 1 is mixed with 500 to 50,000 ppm in terms of phosphorus atoms with respect to the polyester polymer , mixed with ethylene glycol (EG), and added as manganese as a UV stabilizer. A flame retardant oligomer is produced by adding 0.1 to 500 ppm of salt and phosphoric acid in terms of manganese atom and phosphorus atom, respectively. There is provided a method for producing a flame-retardant polyester polymer comprising a second esterification reaction step to be prepared, and a step of transferring and polycondensing the oligomer produced in the second esterification reaction step.

    [Chemical Formula 1]

（式中、Ｒ^１は水素または炭素数１〜１０のヒドロキシアルキル基であり、Ｒ^２は水素、炭素数１〜１０のアルキル基、または炭素数６〜２４のアリール基であり、Ｒ^３は水素、炭素数１〜１０のアルキル基またはヒドロキシアルキル基、またはこれらのエステル形成性官能基である。）

(Wherein R ¹ is hydrogen or a hydroxyalkyl group having 1 to 10 carbon atoms, R ² is hydrogen, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 24 carbon atoms, and R ³ is Hydrogen, an alkyl group having 1 to 10 carbon atoms or a hydroxyalkyl group, or an ester-forming functional group thereof.)

  The above-mentioned flame retardant polyester polymer according to the present invention and the flame retardant polyester produced thereby are excellent in hue and flame retardancy, and also have stability against UV when formed into a final product through a spinning operation. Excellent.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a process flow diagram of an embodiment of the present invention. Referring to FIG. 1, the slurry preparation stage is a stage in which a slurry is prepared in a reaction vessel 1 from terephthalic acid and ethylene glycol which are reaction raw materials. At this stage, a slurry storage tank 2 for storing the prepared slurry may be further provided.

  The first ester reaction stage is a stage in which the slurry is charged into the first esterification reaction tank 3 to generate oligomers. A base oligomer as a product always stays in the reaction tank 3. Between the reaction vessel 3 and the reaction vessel 5, a transfer line filter 4 for transferring the oligomer prepared in the reaction vessel 3 may be provided. The filter 4 can be a basket filter.

  The second esterification reaction stage is a stage in which the oligomer produced in the first esterification reaction stage is transferred to the second esterification reaction tank 5 to produce a flame retardant oligomer. Here, 500 to 50,000 ppm of a phosphorus-based flame retardant represented by the following chemical formula 1 is added in terms of phosphorus atom to the polyester polymer, and manganese salt and phosphorus compound as UV stabilizers are converted into manganese atom and phosphorus, respectively. 0.1 to 500 ppm is added in terms of atoms.

  Between the reaction tank 5 and the polycondensation reaction tank 7, a transfer line filter 6 for transferring the oligomer prepared in the reaction tank 5 may be provided. The filter 6 can be a basket filter.

  The polycondensation step is a step in which the oligomer produced in the second esterification reaction step is transferred and polycondensed under high vacuum.

  Here, a pelletizer 8 for discharging the produced polymer into a chip may be provided.

  A method of polycondensation under high vacuum after producing bishydroxyethyl terephthalate and these low-polymerization oligomers by directly reacting terephthalic acid (TPA) and ethylene glycol (EG) as reaction raw materials is already known. However, in the present invention, in order to produce a polyester polymer having permanent flame retardancy, the phosphorous flame retardant represented by the above chemical formula 1 is introduced into the second esterification reaction stage, and UV stabilization is achieved. It is a method for producing a flame retardant polyester polymer in which a manganese salt and a phosphorus compound as an agent are added in an amount of 0.1 to 500 ppm in terms of manganese atom and phosphorus atom, respectively. Hereafter, each characteristic structure of this invention is demonstrated in detail.

1. Selection of Phosphorus Flame Retardant As a result of considering environmental harmlessness, excellent flame retardancy, polymerization processability, production cost, combustion behavior of flame retardant yarn, etc., the phosphorus flame retardant represented by Chemical Formula 1 was suitable. It was.

  Since this phosphorus flame retardant has a high phosphorus content relative to the molecular weight of the flame retardant, a sufficient flame retardant effect can be obtained even if it is used in a small amount, and it is advantageous in terms of process stability. In addition, when compared with conventional flame retardants containing phosphophenanthrene groups, the generation of soot and toxic gases is reduced during combustion due to the small amount of aromatic groups.

2. Selection of content of phosphorus-based flame retardant in polymer As a result of various tests conducted by the present inventors in order to select the content of phosphorus-based flame retardant to be injected into polymer, phosphorus-based flame retardant to be input It has been found that the content of is not particularly related to the structure of the phosphorus-based flame retardant represented by the chemical formula 1, and is suitably 500 to 50,000 ppm in terms of phosphorus atoms relative to the polymer. In particular, from the viewpoint of polymerization processability and raw yarn production, it has been found that 1,000 to 20,000 ppm is more suitable in terms of phosphorus atoms relative to heavy objects. When the content of the phosphorus flame retardant is less than 500 ppm in terms of phosphorus atom relative to the polymer, the intended flame retardant effect cannot be expected, and when it exceeds 50,000 ppm, the degree of polymerization of the produced polyester is increased. Since it is difficult, the crystallinity is lowered so much that it is difficult to produce the fiber, which is not preferable.

3. Method of charging a phosphorus-based flame retardant into a reaction tank The method of charging a flame retardant represented by Chemical Formula 1 varies depending on the properties of the flame retardant. When the flame retardant represented by Chemical Formula 1 is a solid phase, it can be charged as an ethylene glycol (EG) solution or a dispersed phase, and when it is a liquid phase, it can be charged as a flame retardant alone or in a solution with EG. is there. The amount of EG to be charged as a solution or a dispersed phase is advantageously charged within a range satisfying the following formula 1.

[Formula 1]
0.2 x flame retardant (g) x (FN _{flame retardant} x 62) / (MW _{flame retardant} ) x (1 + α) ≤ EG (g) ≤ 3 x flame retardant (g) x (FN _{flame retardant} x 62) / ( MW- _{flame retardant} ) × (1 + α)
( _Where FN _{flame retardant} is the number of carboxylic acid groups per mole of flame retardant, MW _{flame retardant} is the molecular weight of the flame retardant (g / mol), α is 1 if the flame retardant is a solid phase, 1 liquid If it is a phase, it is a constant of 0.)
If the reaction rate of the oligomer transferred to the second esterification reactor is 95% or more, it can be ignored because the acid value of the oligomer is small, but if it is less than 95%, it corresponds to this. More EG must be added. At this time, the amount of EG is preferably set to an amount satisfying the following formula 2 according to the acid value of the oligomer.

[Formula 2]
AV _oligomer x 31/1000 ≦ EG (g) ≦ AV _oligomer x 62/1000
(In the formula, A V _{-o ligomer} is the acid value of the oligomer, and the unit is (KOH equivalent) / (1 kg polymer).)
When the amount (g) of EG added at the time of adding the _{flame retardant} is less than 0.2 × flame retardant (g) × (FN _{flame retardant} × 62) / (MW _{flame retardant} ) × (1 + α), it is added. The flame retardant has a high viscosity and is difficult to be charged into the reaction tank, and the esterification reaction of the flame retardant becomes difficult. The amount of EG charged (g) is 3 x flame retardant (g) x ( Addition of a flame retardant is advantageous if it is more than FN _{flame retardant} x 62) / (2 x MW _{flame retardant} ) x (1 + α), but the amount of DEG produced increases and heat resistance is reduced.

4). Adjustment of the content of diethylene glycol (hereinafter referred to as “DEG”) If the content of DEG increases during the production of polyester by the TPA method, there is a problem that the heat resistance of the polymer decreases. Since the amount of DEG produced increases as the acidity of the reactant increases, a method for lowering the acidity is required.

  What the inventors have tested as a method for lowering the acidity was to introduce an alkaline substance and to introduce a phosphorus compound represented by Chemical Formula 1 into the reaction vessel 5 in FIG. The latter was found to be more advantageous in terms of quality stability. Of course, it is not excluded from the present invention that an alkaline substance is introduced into the reaction tank 3 or 5 or an alkaline substance is introduced into the phosphorus compound represented by the chemical formula 1.

  By introducing the phosphorus compound represented by Chemical Formula 1 into the reaction vessel 5 in FIG. 1, it is possible to keep the DEG content 3.0% by weight or less compared to the polymer and keep it uniform to prevent deterioration of physical properties. In addition, there is no problem in spinning, false twisting, and dyeing, which is preferable.

  When the phosphorus compound of Chemical Formula 1 is introduced into the slurry storage tank 2 or the reaction tank 3, the acidity of the reaction product becomes high, causing a problem that DEG increases continuously.

5. Selection of UV stabilizers Flame retardant polyester fibers are primarily used for interior decorations such as curtains, so UV stability is required. Therefore, the inventors conducted research on UV stability. Many organic and inorganic stabilizers have been developed as UV stabilizers, but it has been found that manganese phosphate is most suitable from the viewpoint of functionality and cost.

  However, since manganese phosphate does not dissolve in EG, if manganese phosphate is added directly to the reaction system, agglomeration occurs and many foreign substances are formed in the polymer, resulting in problems such as an increase in pack pressure during spinning. I found it to be. Therefore, as a result of various tests on methods for producing a manganese compound in a polymerization system, the present inventors have found that a solution is possible by separately adding a manganese salt and a phosphorus compound.

  Further, the content of the manganese salt used as the UV stabilizer is preferably 0.1 to 500 ppm, more preferably 0.2 to 200 ppm in terms of manganese atom relative to the polymer. If the manganese salt content is less than 0.1 ppm, it is difficult to obtain the desired UV stability, and if the manganese salt content exceeds 500 ppm, a problem occurs in dispersibility, thereby increasing the pack pressure during spinning, etc. Problem arises.

  The content of the phosphorus compound added together with the manganese salt is preferably in the range of 0.1 to 500 ppm in terms of phosphorus atom relative to the polymer. More preferably, the range is 0.2 to 200 ppm. The phosphorus-based material may be added as long as the reaction with the manganese salt does not cause a problem. However, when the content of the phosphorus-based material exceeds 500 ppm, the activity of the catalyst decreases and the polymerization processability decreases.

6). Addition of comonomer The polyester copolymer is often the third comonomer in order to provide various functions. The flame-retardant polyester targeted in the present invention can also be charged with a third comonomer for imparting functionality. Examples of the comonomer that can be used in the present invention include the following.

  Examples of the dicarboxylic acid or its ester-forming derivative include aromatic dicarboxylic acids such as isophthalic acid, biphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, and ester-forming derivatives thereof such as 1, Alicyclic dicarboxylic acids such as 4-cyclohexanedicarboxylic acid and alkyl dicarboxylic acids having 2 to 6 carbon atoms, or ester-forming derivatives thereof, acyl chlorides thereof, and the like can be used.

  In order not to significantly reduce the economic properties and the physical properties of the flame-retardant polyester, the molar ratio of terephthalic acid to the total dicarboxylic acid is preferably 70% or more. If it is less than 70 mol%, the melting point, the glass transition temperature, etc. are lowered, causing the problem of moldability, and when some expensive copolymerization monomers are used, the production cost is increased.

  Examples of the glycol component include 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and the like. Alkanediols such as 1,4-cyclohexanediol, alicyclic glycols such as 1,4-cyclohexanedimethanol, aromatic glycols such as bisphenol A and bisphenol S, and ethylene oxide or propylene oxide adducts of aromatic diols, etc. It is. In particular, in order to develop proper polymer properties, the molar ratio of ethylene glycol in the total polymer glycol component is preferably 70% or more.

7). Molar ratio of dicarboxylic acid containing TPA and glycol containing EG for reactivity in the reaction vessel The molar ratio of dicarboxylic acid to glycol (mole ratio of glycol / dicarboxylic acid) is preferably 1.01 to 2.0. . When the molar ratio is lower than 1.01, the esterification reaction is difficult to perform and the reaction rate is low, the amount of dicarboxylic acid remaining without being reacted is large, and the filter replacement period in the polymerization process is shortened. In addition, it is easy to show the problem that the product remains as a foreign substance in the polymer, the optical properties such as transparency and haze of the product are lowered, and the pack pressure rapidly increases during the spinning process. On the other hand, when the molar ratio is higher than 2.0, the capacity of the reflux tower in the polymerization process may be exceeded, the process becomes unstable, and the formation of DEG which causes a decrease in the heat resistance of the polymer and the product. This is disadvantageous for the subsequent process of the polymer.

8). Polycondensation catalyst As the polymerization catalyst, a catalyst used in general polyester polymerization can be used, for example, antimony trioxide, antimony compounds such as antimony triacetate, and, for example, tetrabutyl titanium, tetraisopropyl titanium. Titanium compounds such as can be used.

  The content of these catalysts is suitably 10 to 1,000 ppm in terms of metal content relative to the polymer weight. If the catalyst content is less than 10 ppm, the activity of the catalyst is too low, and if the catalyst content is more than 1,000 ppm, these catalysts form foreign matter and the production cost increases. .

9. Additives As the flame-retardant polyester polymer to be produced, various additives can be added depending on the application. In order to improve the hue of the polymer, an inorganic metal salt such as cobalt acetate or an organic pigment can be used as a toning agent. In order to use as a fiber, it is also possible to introduce 100 to 30,000 ppm of titanium dioxide and 100 to 30,000 ppm of silica or barium sulfate. The input amount and the input method of these inorganic additives can be applied in accordance with the normal input amount and input method when a general polyester is used for fibers.

  Hereinafter, the present invention will be specifically described with reference to examples. The present invention is not limited to these examples.

  Prior to the description of the examples, a fiber performance evaluation method and the like will be described.

  Intrinsic viscosity (IV): It is dissolved in a 6: 4 weight ratio solution of phenol and 1,1,2,2-tetrachloroethane and measured at 20 ° C. using an Ubbelohde tube.

Melting point (T _m ): Measured with a differential scanning calorimeter (Perkin Elmer DSC7).

  DEG: The polymer is decomposed with triethanolamine and analyzed by gas chromatography.

  UV stability: The produced polymer is stretched on a glass plate, exposed to UV for 48 hours with Q-Panel QUV, the intrinsic viscosity is measured, and the intrinsic viscosity maintenance rate is evaluated.

(Initial intrinsic viscosity-intrinsic viscosity after treatment) / initial intrinsic viscosity x 100
Flame retardancy: The fiber is knitted and evaluated by the Limited Oxygen Index (LOI).

Example 1
A slurry was prepared from 1300 kg of TPA and 560 kg of EG. The prepared slurry was charged into DE-1 reaction vessel 3 in which 1.5 tons of bishydroxyethyl terephthalate and its low molecular weight oligomer were stirred at 260 ° C. for 3 hours while maintaining 260 ° C. When stirring was continued while refluxing for 30 minutes, the esterification reaction rate reached 97%. 1.5 tons in the produced oligomer was left in the DE-1 reactor, and the rest was transferred to the DE-2 reactor. In the DE-2 reaction tank 5, 68 kg of a flame retardant in which R ₁ is H, R ₂ is a phenyl group, and R ₃ is hydrogen among the substances represented by Chemical Formula 1 (6500 ppm in terms of phosphorus atom relative to the polyester polymer, Example 2) EG 68 kg mixed with EG 68 kg at room temperature, and manganese salt and phosphorous compound for preparing UV stabilizer, manganese acetate and phosphoric acid are 22 ppm and 100 ppm in terms of manganese atom and phosphorus atom, respectively. After adding 0.3% by weight of titanium dioxide as a quencher to the polymer and stirring at 260 ° C., the entire oligomer in the DE-2 reaction tank 5 is transferred to the polycondensation reaction tank. Thereafter, 200 g of an antimony trioxide solution dissolved in EG at 2% by weight was added and polycondensed in the same manner as ordinary PET polycondensation to produce a polymer. The average and the range of the molecular polymer analysis results are shown in Table 1.

In Example 1, in Formula 1 below, the FN _{flame retardant} is 1, the MW _{flame retardant} is 214, and α is 1. Moreover, since the quantity of EG is about 7.88-188 kg, the following numerical formula 1 is satisfy | filled.

[Formula 1]
0.2 x flame retardant (g) x (FN _{flame retardant} x 62) / (MW _{flame retardant} ) x (1 + α) ≤ EG (g) ≤ 3 x flame retardant (g) x (FN _{flame retardant} x 62) / ( MW- _{flame retardant} ) × (1 + α)
( _Where FN _{flame retardant} is the number of carboxylic acid groups per mole of flame retardant, MW _{flame retardant} is the molecular weight of the flame retardant (g / mol), α is 1 if the flame retardant is a solid phase, 1 liquid If it is a phase, it is a constant of 0.)
In Example 1, the molar ratio of dicarboxylic acid to EG is about 1.15.

Comparative Example 1
A slurry was prepared from a flame retardant 68 kg, TPA 1300 kg and EG 560 kg in which R ₁ is H, R ₂ is a phenyl group, and R ₃ is hydrogen among the substances represented by Chemical Formula 1. The prepared slurry was charged for 3 hours while keeping the temperature at 260 ° C. in the DE-1 reactor 3 in which the oligomer produced with the same composition as the polymer was stirred at 260 ° C. When stirring was continued while refluxing for 30 minutes, the esterification reaction rate reached 96.7%. 1.5 tons in the produced oligomer was left in the DE-1 reactor 3, and the rest was transferred to the DE-2 reactor. The DE-2 tank was charged with 22 ppm and 30 ppm of manganese salt and phosphoric acid as manganese compounds for preparation of UV stabilizers and phosphorous compounds in terms of manganese atom and phosphorus atom, respectively, with respect to the theoretical polymer. After adding 0.3% by weight of titanium dioxide to the polymer and stirring at 260 ° C., the entire oligomer in the DE-2 reaction tank 5 is transferred to the polycondensation reaction tank, and then added to the EG. A polymer was produced by adding 200 g of an antimony trioxide solution dissolved in% by weight and performing polycondensation in the same manner as ordinary PET polycondensation. The average and the range of the polymer analysis results are shown in Table 1.

  As shown in Table 1, the change in DEG content is large, and the change in melting point is also large.

  In Comparative Example 1, the molar ratio of dicarboxylic acid to EG is about 1.07.

Example 2
A polymer was produced in the same manner as in Example 1 except that the phosphorus-based flame retardant and EG were reacted at 190 ° C. for 4 hours and then charged into the DE-2 reaction tank.

Reference example 3
A polymer was produced in the same manner as in Example 1 except that the phosphorus-based flame retardant and EG were reacted at 190 ° C. for 4 hours and then charged into a polycondensation reaction tank.

Comparative Example 2
In the second esterification reaction tank, except that 68 kg of a flame retardant in which R ₁ is H, R ₂ is a phenyl group, and R ₃ is hydrogen among the substances represented by Chemical Formula 1 is not mixed with EG, A polymer was produced in the same manner as in Example 1.

Example 4
Except for adding 82 kg of the substance represented by Chemical Formula 1 as a flame retardant having R ₁ as H, R ₂ as phenyl group, and R ₃ as hydroxyethyl group (—CH ₂ CH ₂ OH), the same procedure as in Example 1 was performed. A polymer was produced.

Comparative Example 3
A polymer was produced in the same manner as in Example 1 except that a manganese salt and a phosphorus compound were not used.

Example 5
The polymer prepared in Example 2 was dried in a vacuum dryer for 24 hours. The dried polymer was extruded at a spinning temperature of 280 ° C. using an extruder having an inner diameter of 95 mm, the first Godet roller heated at 80 ° C. was 1350 m / min, and the second heated at 120 ° C. A 75 denier / 72 filament fiber was produced by a direct spinning drawing method with a godet roller speed of 4100 m / min. The produced oxygen yarn was knitted by hose knitting, and then the limiting oxygen index (LOI) was evaluated. The LOI index was 32 and exhibited excellent flame retardancy.

（平均／範囲で表記、範囲＝最大値−最小値）
＊１．時間：重縮合反応時間であって、触媒投入後から反応終了時までの時間（分）である。

(Expressed as average / range, range = maximum value-minimum value)
* 1. Time: polycondensation reaction time, which is the time (minutes) from the introduction of the catalyst to the end of the reaction.

  * 2. IV: Intrinsic viscosity, unit is dl / g.

  * 3. DEG: The unit is wt%.

  As can be seen from Table 1, all the Examples have a DEG of 3.0 wt% or less, and Comparative Example 3 has a DEG of 3.0 wt% or less. However, since the manganese salt and phosphorus compound as UV stabilizers were not added, the IV maintenance rate was significantly reduced.

It is a process flowchart which shows an example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Preparation tank 2 Slurry storage tank 3 1st esterification reaction tank (DE-1)
4 Transfer line filter 5 Second esterification reactor (DE-2)
6 Transfer line filter 7 Polycondensation reaction tank 8 Pelletizer

Claims (5)

In the method for producing a flame-retardant polyester polymer using the terephthalic acid method,
Preparing a slurry of terephthalic acid (TPA) and ethylene glycol (EG) as reaction raw materials;
A first esterification reaction stage in which the slurry is charged into a first esterification reaction tank to produce an oligomer;
The oligomer produced in the first esterification reaction stage is transferred to a second esterification reaction tank, and a phosphorus-based flame retardant represented by the following chemical formula 1 is converted to a phosphorus atom in terms of phosphorus atom of 500 to 50,000 ppm, While mixing with ethylene glycol (EG) and adding it, manganese salt and phosphoric acid as UV stabilizers are added in an amount of 0.1 to 500 ppm in terms of manganese atom and phosphorus atom, respectively, to produce a flame-retardant oligomer. A second esterification reaction stage;
And a step of transferring and polycondensing the oligomer produced in the second esterification reaction step.
[Chemical Formula 1]

(Wherein R ¹ is hydrogen or a hydroxyalkyl group having 1 to 10 carbon atoms, R ² is hydrogen, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 24 carbon atoms, and R ³ is Hydrogen, an alkyl group having 1 to 10 carbon atoms, or a hydroxyalkyl group.) In the manufacturing method of the flame-retardant polyester polymer of Claim 1,
A method for producing a flame-retardant polyester polymer, wherein the content of DEG (diethylene glycol) is 3.0% by weight or less based on the polyester polymer in the second esterification reaction tank. In the manufacturing method of the flame-retardant polyester polymer of Claim 1,
Isophthalic acid, biphenyl dicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, or ester-forming derivatives thereof, and alicyclic dicarboxylic acids, alkyl dicarboxylic acids having 2 to 6 carbon atoms, or these the method of producing a flame-resistant polyester polymer further characterized by introducing at least one dicarboxylic acid or ester-forming derivative thereof as comonomer chosen from ester-forming derivatives. In the manufacturing method of the flame-retardant polyester polymer of Claim 1,
Flame retardancy characterized in that at least one glycol component selected from alkanediol, alicyclic glycol, aromatic glycol, aromatic diol, and propylene oxide adduct is further added as a comonomer. A method for producing a polyester polymer. In the manufacturing method of the flame-retardant polyester polymer of Claim 1,
The method for producing a flame-retardant polyester polymer, wherein a molar ratio of the dicarboxylic acid containing TPA and ethylene glycol (EG) (glycol / dicarboxylic acid molar ratio) satisfies 1.01 to 2.0. .

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