JP2009108279A - Polyester master batch for improving color tone and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester master batch for improving color tone, with which the color tone of a polymer having a tinge of yellow is improved; and to provide a method for producing the same. <P>SOLUTION: The polyester master batch for improving color tone comprises a specified phosphonic acid ester compound added in an amount of 500 ppm to 5 wt.%, in terms of phosphorus atom, to a polyester. The method for producing the master batch is also provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a polyester masterbatch for improving color tone and a method for producing the same. More specifically, the present invention relates to a color tone improving polyester masterbatch capable of improving the color tone of polyester by melt-kneading and a method for producing the same.

  Polyester is used for various purposes because of its useful functionality, and is used for clothing, materials, and medical use, for example. Among them, polyethylene terephthalate is excellent in terms of versatility and practicality and is preferably used.

  In general, polyethylene terephthalate is produced from terephthalic acid or its ester-forming derivative and ethylene glycol. The process of producing a high molecular weight polymer and the resulting polymer are directly or after chipping and re-melting and molding. When receiving heat history close to 300 ° C. For this reason, in the case of polyester with insufficient thermal stability, the decomposition reaction is vigorous, and undesirable phenomena such as coloration of the polymer and, in some cases, generation of foreign matter occur.

  Polyethylene terephthalate is usually manufactured using polycondensation catalysts such as antimony compounds, titanium compounds, and aluminum compounds, but these metal catalysts accelerate the decomposition reaction during the molding process and give the polymer a yellowish color. The color tone will be damaged. The fact that the polymer is yellowish is not preferable, for example, when polyester is used as the fiber, since it impairs the commercial value of the fiber for clothing.

  Thus, various studies have been made so far to reduce the yellowness of the polymer. For example, there is a method (Patent Document 1) in which a master batch pellet to which a dye or a pigment is added is prepared and kneaded with a yellowish polyester to adjust the color tone (Patent Document 1), but this method certainly suppresses the yellowness of the polymer. However, it is not preferable because the brightness and transparency of the polymer are lowered at the same time. On the other hand, studies for improving the color tone of a polymer by adding a phosphorus compound have been made widely. This method suppresses the activity of the metal catalyst with a phosphorus compound and improves the color tone of the polymer. For example, a method of suppressing coloration at the time of molding by deactivating a metal catalyst by kneading a polymer and a phosphorus compound or a polymer containing a phosphorus compound at a high concentration (Patent Documents 2 and 3) and the like can be mentioned. Although this method can surely reduce the coloration during the molding process, it is not effective for the polymer that is markedly colored.

Therefore, as a result of intensive studies on improving the above problems in the present invention, it has been found that the object of the present invention can be achieved by a polyester masterbatch containing a phosphorus compound having a specific structure at a high concentration.
JP 2000-80172 A (Claims) JP 2006-152066 A (Claims) JP 2006-45455 A (Claims)

  The object of the present invention relates to a polyester masterbatch for improving the color tone for solving the above-mentioned conventional problems, that is, improving the color tone of a yellowish polymer, and a method for producing the same. It is providing the polyester masterbatch for color tone improvement which can improve the color tone of this, and its manufacturing method.

  The subject of the present invention is characterized by containing 500 ppm to 5% by weight in terms of phosphorus atoms with respect to the polyester obtained from at least one of the phosphorus compounds represented by Formula 1, Formula 2, and Formula 3. This can be achieved with a polyester masterbatch for color tone improvement.

(In Formula 1, Formula 2, and Formula 3, R _{1 to} R ₆ each independently represent a hydroxyl group or a hydrocarbon group having 1 to 20 carbon atoms, and m is 0 or 1.)

  The polyester masterbatch containing 500 ppm to 5% by weight in terms of phosphorus atoms is melt-kneaded with respect to the polyester from which at least one of the phosphorus compounds represented by Formula 1, Formula 2, and Formula 3 of the present invention is obtained. This can drastically improve the color tone of the polyester. This polyester masterbatch can solve the problem of deterioration in color tone, which is a problem in the production of molded articles for fibers, films, bottles and the like.

  Hereafter, the manufacturing method of the polyester masterbatch and polyester masterbatch of this invention is demonstrated concretely. The color tone index in the present invention is measured using a hunter type color difference meter, and refers to the L value as the brightness index and the b value as the yellow index. When the L value is large, the lightness is high, and when the b value is large, the yellowness is high. To improve the color tone in the present invention means to reduce the b value while suppressing a decrease in the L value.

  The polyester masterbatch for color tone improvement according to the present invention contains 500 ppm to 5% by weight in terms of phosphorus atoms with respect to the polyester from which at least one of the phosphorus compounds represented by Formula 1, Formula 2, and Formula 3 is obtained. Is essential. The reason why the phosphorus compounds represented by Formula 1, Formula 2, and Formula 3 are essential will be described in detail below.

  It is presumed that the coloring of the polyester is caused by a side reaction of polyester polymerization, as specified in a saturated polyester resin handbook (Nikkan Kogyo Shimbun, first edition, pages 178 to 198). In this polyester side reaction, carbonyl oxygen is activated by a metal catalyst or the like, and β hydrogen is extracted to generate a vinyl end group component and an aldehyde component. Further, the side reaction causes the polymer to become yellowish. Take on. Such a side reaction is empirically known to be particularly noticeable when a titanium compound or an aluminum compound is used as a polycondensation catalyst, and is a problem to be solved.

  In response to the above problems, as described above, improvement of color tone has been studied by two methods. One is a method of changing the color tone by using a blue-based dye or pigment. However, in this method, since other color components are added to the colored polymer, the yellow tone of the color tone can be suppressed. However, it is inevitable that the brightness and transparency of the polymer will be lowered at the same time. Reducing the brightness and transparency of the polymer is an undesirable characteristic when used for film or bottle applications, for example. Another method includes adding a phosphorus compound. This method adjusts the activity of the metal catalyst by interacting a phosphorus compound with the metal catalyst to suppress thermal decomposition and prevent coloring. However, in this method, when the phosphorus compound is added to the polyester by melt kneading or the like, the coloring in the subsequent melt molding step is certainly suppressed, but the polymer already colored in the polycondensation reaction step is not added. Does not make sense. On the other hand, if the phosphorus compound is added before the polycondensation reaction, the phosphorus compound decreases the polycondensation activity as well as the side reaction activity of the metal catalyst, so it is difficult to add a certain amount or more, and the effect is limited. .

  However, in the polyester masterbatch containing 500 ppm to 5% by weight in terms of phosphorus atom to the polyester from which at least one of the phosphorus compounds represented by Formula 1, Formula 2, and Formula 3 of the present invention is obtained, The yellowness can be suppressed without lowering the brightness. Although the mechanism of this effect is not completely clarified at present, it is caused by the fact that the colored component of the polymer once produced reacts with the phosphorus compound of the present invention to produce a non-colored component. thinking. This is essentially different from the effect of the conventional phosphorus compound on the metal catalyst, or at least cannot be sufficiently achieved by the conventional phosphorus compound.

  Among these, a phosphorus compound represented by Formula 4 is preferably used because the phosphorus compound has high heat resistance and hydrolysis resistance.

(In the above formula 4, R _{7 to} R ₉ each independently represents a hydroxyl group or a hydrocarbon group having 1 to 10 carbon atoms, a + b + c is an integer of 0 to 5, and m is 0 or 1.)
Examples of the phosphorus compound represented by the above formula 4 include, for example, a compound having a = 2, b = 0, c = 0, R ₅ = tert-butyl group, and R ₅ = 2,4 as tetrakis (2,4- Di-t-butylphenyl) [1,1-biphenyl] -4,4′-diylbisphosphonite, which is IRGAFOS P-EPQ (Ciba Specialty Chemicals) or Sandostab P-EPQ (Clariant). (Available from Japan).

  Furthermore, the phosphorus compound represented by Formula 5 is preferable because the heat resistance and hydrolysis resistance of the phosphorus compound are particularly good.

(In the above formula 5, R _{10 to} R ₁₂ each independently represents a hydroxyl group or a hydrocarbon group having 1 to 10 carbon atoms, and m is 0 or 1.)
As the phosphorus compound represented by the above formula 5, tetrakis (2,4-di-t-butyl-5 is used as a compound of R ₈ = tert-butyl group, R ₉ = tert-butyl group, R ₁₀ = methyl group. -Methylphenyl) [1,1-biphenyl] -4,4'-diylbisphosphonite, and this compound is available as GSY-P101 (Osaki Kogyo Co., Ltd.). These compounds may be used alone or in combination.

  If the amount of the phosphorus compound added to the polyester masterbatch of the present invention is 500 ppm or less in terms of phosphorus atoms with respect to the polyester, the color tone improving effect is not sufficient, and if it exceeds 5% by weight, foreign matters derived from the phosphorus compound may be generated. There is a case where the color tone L value is lowered. It is preferable that it is the range of 750 ppm-2 weight% in conversion of a phosphorus atom with respect to polyester.

  The polyester masterbatch of the present invention is a polyester obtained from a dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof, preferably the aromatic dicarboxylic acid component is 70 mol% or more of the acid component, Polyester containing 70 mol% or more of aliphatic dicarboxylic acid.

  Examples of the dicarboxylic acid component constituting the polyester masterbatch of the present invention include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyl-4,4′-dicarboxylic acid, diphenoxyethanedicarboxylic acid and ester-forming derivatives thereof. Etc.

  Examples of the diol component constituting the polyester masterbatch of the present invention include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and cyclohexanedimethanol. And ester-forming derivatives thereof.

  Among these, polyethylene terephthalate using terephthalic acid as the dicarboxylic acid component and ethylene glycol as the diol component, or a polyester copolymer mainly containing ethylene terephthalate units is preferable.

  The polyester masterbatch according to the present invention can be obtained by adding at least one of the phosphorus compounds represented by Formula 1, Formula 2, and Formula 3 in an arbitrary manner in an amount of 500 ppm to 5% by weight in terms of phosphorus atoms. . Specific polyester master batch production methods include the addition of phosphorus compounds represented by Formula 1, Formula 2, and Formula 3 before the polycondensation reaction, and the target after starting the polycondensation reaction. Examples thereof include a method of adding before reaching the degree of polymerization and a method of adding after completion of the polycondensation reaction. In the method of adding from the start of the polycondensation reaction until the target degree of polymerization is reached, or the method of adding after the completion of the polycondensation reaction, a large amount of phosphorus compound can be added without impairing the polycondensation reaction activity. preferable.

  When adding a phosphorus compound by a method of adding a phosphorus compound between the start of the polycondensation reaction and the time when the polymerization reaches the target degree of polymerization, bring in a large amount of diol components such as ethylene glycol. When this is done, polyester depolymerization (polyester main chain scission reaction) proceeds, and therefore, a method of adding a phosphorus compound alone or adding master pellets containing phosphorus at a high concentration is preferable. At this time, the phosphorus compound may be added in several portions, or may be continuously added with a feeder or the like. In addition, the above-described method for adding a phosphorus compound is preferably added in a container that can be dissolved or melted in a polymerization system and is made of a polymer having substantially the same component as the polymer obtained in the present invention. . When adding a phosphorus compound in a container as described above, the addition to the polymerization reactor under reduced pressure prevents the phosphorus compound from scattering and flowing out of the reduced pressure line. And a desired amount of phosphorus compound can be added to the polymer. The container referred to in the present invention is not limited as long as it contains phosphorus compounds, and includes, for example, an injection-molded container having a lid or a stopper, or a sheet or film formed into a bag shape by sealing or sewing. More preferably, the container described above creates an air vent. When a phosphorus compound is added to a container that has been vented, even if it is added to the polymerization reactor under vacuum conditions, the container bursts due to air expansion and the phosphorus compound flows out to the decompression line, or the upper part of the polymerization reactor. The phosphorus compound can be added to the polymer in a desired amount without adhering to the wall surface. If the container is too thick, it takes longer to dissolve and melt, so it is better to make the container thinner. However, the container should be thick enough not to rupture when the phosphorus compound is sealed or added. For this purpose, a material having a thickness of 10 to 500 μm and uniform thickness is preferable.

  In addition, in the method of adding after the completion of the polycondensation reaction, the polyester after the completion of the polycondensation reaction and the phosphorus compound represented by Formula 1, Formula 2, and Formula 3 are melt kneaded with a twin screw extruder, Examples include a method of melt-kneading polyester and phosphorus pellets of Formula 1, Formula 2, and Formula 3 containing phosphorus in a high concentration with a twin screw extruder.

  The intrinsic viscosity of the polyester masterbatch of the present invention is not particularly limited, but it is preferable that the polyester masterbatch has a viscosity capable of being melt kneaded with a twin screw extruder. Specifically, the intrinsic viscosity ([η]) measured at 25 ° C. using orthochlorophenol as a solvent is preferably in the range of 0.4 dl / g to 1.2 dl / g, 0.5 dl / g More preferably, it is in the range of ˜0.9 dl / g, particularly preferably in the range of 0.6 dl / g to 0.7 dl / g.

  In the polyester masterbatch of the present invention, a titanium compound, an aluminum compound, an antimony compound, a germanium compound, or the like is used as a polycondensation catalyst. Among them, a titanium compound or an aluminum compound that can reduce the addition amount because of its high catalytic activity is preferably used.

  When using a titanium compound as a polycondensation catalyst, it is preferable to add so that it may become 1-30 ppm in conversion of a titanium atom with respect to the polymer obtained. When it is 3 to 20 ppm, the thermal stability and color tone of the polymer become better, and it is more preferably 5 to 10 ppm.

  Here, as the titanium compound, titanium complex, tetra-n-propyl titanate, tetra-i-propyl titanate, tetra-n-butyl titanate, tetra-n-butyl titanate tetramer, tetra-t-butyl titanate, tetracyclohexyl titanate, Titanium alkoxide such as tetraphenyl titanate, tetrabenzyl titanate, titanium oxide obtained by hydrolysis of titanium alkoxide, titanium-silicon or zirconium composite oxide obtained by hydrolysis of a mixture of titanium alkoxide and silicon alkoxide or zirconium alkoxide, Titanium acetate, titanium oxalate, potassium potassium oxalate, sodium titanium oxalate, potassium titanate, sodium titanate, titanium titanate-aluminum hydroxide mixture, titanium chloride, Titanium bromide-aluminum chloride mixture, titanium bromide, titanium fluoride, potassium hexafluorotitanate, cobalt hexafluorotitanate, manganese hexafluorotitanate, ammonium hexafluorotitanate, titanium acetylacetonate, etc. It is done. Among these, a titanium complex having a polyvalent carboxylic acid and / or hydroxycarboxylic acid and / or nitrogen-containing carboxylic acid as a chelating agent is preferable from the viewpoint of thermal stability and color tone of the polymer. Examples of chelating agents for titanium compounds include polyvalent carboxylic acids such as phthalic acid, trimellitic acid, trimesic acid, hemititic acid, pyromellitic acid, and hydroxycarboxylic acids such as lactic acid, malic acid, tartaric acid, and citric acid. As the nitrogen-containing carboxylic acid, ethylenediaminetetraacetic acid, nitrilotripropionic acid, carboxyiminodiacetic acid, carboxymethyliminodipropionic acid, diethylenetriaminopentaacetic acid, triethylenetetriminohexaacetic acid, iminodiacetic acid, iminodipropion Examples include acid, hydroxyethyliminodiacetic acid, hydroxyethyliminodipropionic acid, methoxyethyliminodiacetic acid and the like. These titanium compounds may be used alone or in combination.

  When using an aluminum compound as a polycondensation catalyst, it is preferable to add so that it may become 5-200 ppm in conversion of an aluminum atom with respect to polyester obtained. When it is 10 to 150 ppm, the thermal stability and color tone of the polymer become better, and more preferably 20 to 100 ppm.

  Examples of the aluminum compound include aluminum carboxylate, aluminum inorganic acid salt, aluminum alkoxide, aluminum chelate compound, aluminum oxide, and the like. Examples of aluminum carboxylates include aluminum carboxylate formate, aluminum acetate, basic aluminum acetate, aluminum propionate, aluminum acrylate, aluminum laurate, aluminum stearate, aluminum benzoate, aluminum lactate, aluminum citrate, and aluminum salicylate. Examples of inorganic acid salts of aluminum include aluminum chloride, aluminum hydroxide, aluminum hydroxide chloride, and aluminum carbonate. Examples of aluminum alkoxide include aluminum methoxide, aluminum ethoxide, aluminum isopropoxide, and aluminum. Butoxide and the like, and aluminum chelate compounds include aluminum acetylacetonate, aluminum Cetyl acetate, include aluminum ethylacetoacetate, and examples of the aluminum oxide, and the like trioxide aluminum. These aluminum compounds may be used alone or in combination.

  When using an antimony compound as a polycondensation catalyst, it is preferable to add so that it may become 10-1000 ppm in conversion of an antimony atom with respect to polyester obtained. When it is 50 to 700 ppm, the thermal stability and color tone of the polymer become better, more preferably 150 to 400 ppm.

  Examples of the antimony compounds include antimony oxides, antimony carboxylic acids, antimony alkoxides, and the like. For example, antimony oxide includes antimony trioxide, antimony pentoxide and the like, antimony carboxylic acid includes antimony acetate, antimony oxalate, antimony potassium tartrate and the like, and antimony alkoxide includes antimony tri-n-butoxide. And antimony triethoxide. Of these, antimony oxide is preferable, and antimony trioxide is particularly preferable. These antimony compounds may be used alone or in combination.

  When using a germanium compound as a polycondensation catalyst, it is preferable to add it so that it may become 10-1000 ppm in conversion of a germanium atom with respect to polyester obtained. When it is 50 to 500 ppm, the thermal stability and color tone of the polymer become better, more preferably 150 to 400 ppm.

  Examples of germanium compounds include germanium oxides, germanium alkoxides, and organic germanium compounds. Germanium oxides include germanium dioxide, germanium alkoxides include germanium ethoxide, germanium tetrabutoxide, and organic germanium compounds include methyl germane, ethyl germane, trimethyl germanium methoxide, dimethyl germanium. Examples thereof include diacetate and tributyl germanium acetate. Of these, germanium dioxide is preferably used. These germanium compounds may be used alone or in combination.

  The polycondensation catalyst referred to in the present invention is generally a series of reactions for synthesizing a polyester from dicarboxylic acid or its ester-forming derivative and diol or its ester-forming derivative. An esterification reaction that is a reaction, or (2) an ester exchange reaction that is a reaction between an ester-forming derivative component of a dicarboxylic acid and a diol component, and (3) the ester reaction or transesterification reaction is substantially completed. Among the polycondensation reactions that increase the degree of polymerization of a polyethylene terephthalate low polymer by a dediol reaction, those having the effect of contributing to at least (3) reaction promotion. Therefore, for example, titanium oxide particles that are generally used as inorganic particles in fiber matting agents and the like have substantially no catalytic effect on the above reaction, and are used as the polycondensation catalyst of the present invention. It is different from the titanium compound that can be used.

  The polyester masterbatch of the present invention may contain various additives such as an ultraviolet absorber, a lubricant, a crystal nucleating agent, an antistatic agent, a dye, and a pigment as long as the color tone is not impaired.

  In the polyester masterbatch of the present invention, it is preferable that the color tone in the chip shape is a Hunter value, the L value is in the range of 60 to 95, and the b value is in the range of -6 to 4. More preferably, the L value is in the range of 70 to 90 and the b value is in the range of -5 to 1.

  The polyester masterbatch of the present invention obtains a polyester resin composition excellent in color tone by melt-kneading with a polyester comprising a dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof with a twin-screw extruder. I can do it. At this time, it is preferable that the polyester to be melt-kneaded with the polyester masterbatch is a substantially identical polymer.

  The manufacturing method of the polyester masterbatch of this invention is demonstrated. Although the example of a polyethylene terephthalate is described as a specific example, it is not limited to this.

Polyethylene terephthalate is usually produced by one of the following processes.
That is, (A) a process in which terephthalic acid and ethylene glycol are used as raw materials, a low polymer is obtained by direct esterification reaction, and a high molecular weight polymer is obtained by subsequent polycondensation reaction, and (B) dimethyl terephthalate and ethylene glycol are used as raw materials. In this process, a low polymer is obtained by a transesterification reaction, and a high molecular weight polymer is obtained by a subsequent polycondensation reaction. Here, the esterification reaction proceeds even without a catalyst, but the aforementioned titanium compound may be added as a catalyst. In the transesterification reaction, a compound such as magnesium, manganese, calcium, cobalt, zinc, lithium, or the above-described titanium compound is used as a catalyst, and after the transesterification reaction is substantially completed, it is used for the reaction. In order to inactivate the catalyst, the phosphorus compound is added. The polycondensation catalyst is added to the low polymer obtained in any stage of the series of reactions (A) or (B), preferably in the first half of the series of reactions (A) or (B), and various After adding the additive, a polycondensation reaction is performed to obtain a high molecular weight polyethylene terephthalate. The polyester masterbatch of the present invention can be obtained by adding at least one of the phosphorus compounds represented by Formula 1, Formula 2, and Formula 3 in this optional stage in an amount of 500 ppm to 5% by weight in terms of phosphorus atoms. .

Hereinafter, the present invention will be described in more detail with reference to examples. In addition, the physical-property value in an Example was measured by the method described below.
(1) Intrinsic viscosity of polymer IV
Measurement was performed at 25 ° C. using orthochlorophenol as a solvent.
(2) Color tone of polymer Using a color difference meter (SM color computer model SM-T45, manufactured by Suga Test Instruments Co., Ltd.), it was measured as a Hunter value (L, b value).

Example 1
About 10 kg of bis (hydroxyethyl) terephthalate is charged in advance, 8.3 kg of high-purity terephthalic acid (manufactured by Mitsui Chemicals) and ethylene glycol are added to an esterification reaction tank maintained at a temperature of 250 ° C. and a pressure of 1.2 × 10 ⁵ Pa. (Manufactured by Nippon Shokubai Co., Ltd.) 3.5 kg of slurry is sequentially supplied over 4 hours, and after completion of the supply, an esterification reaction is carried out over another 1 hour, and 10.2 kg of the obtained esterification reaction product is polycondensed. Transferred to.

30 minutes of adding 1.2 g of magnesium acetate (15 ppm in terms of magnesium atom to the polymer) and a citric acid chelate titanium compound equivalent to 10 ppm in terms of titanium atom to the polymer to the esterification reaction product The mixture was previously mixed in another mixing tank and stirred at room temperature for 30 minutes, and then the mixture was added. After 5 minutes, an ethylene glycol slurry of titanium oxide particles was added to the polymer in an amount of 0.3% by weight in terms of titanium oxide particles. After another 5 minutes, the reaction system was decompressed to initiate the reaction. The reactor was gradually heated from 250 ° C. to 290 ° C., and the pressure was reduced to 40 Pa. The time to reach the final temperature and final pressure was both 60 minutes. When 85% of the predetermined stirring torque is reached (2 hours and 30 minutes after depressurization is started), a container having a thickness of 0.2 mm and an internal volume of 2000 cm ³ is formed by injection molding a polyethylene terephthalate sheet. 17600 ppm (1000 ppm in terms of phosphorus atom) of tetrakis (2,4-di-t-butyl-5-methylphenyl) [1,1-biphenyl] -4,4′-diylbisphosphonite is added to the polymer. And added from the top of the reaction can. Thereafter, when the predetermined stirring torque was reached, the reaction system was purged with nitrogen and returned to normal pressure to stop the polycondensation reaction, discharged in a strand form, cooled, and immediately cut to obtain polymer pellets. The time from the start of decompression to the arrival of the predetermined stirring torque was 2 hours and 50 minutes. This obtained polyester master batch is designated as A-1.

Examples 2-4
A polyester was polymerized in the same manner as in Example 1 except that the polycondensation catalyst was changed to a trimellitic acid chelate titanium compound, a tetrabutoxy titanium compound, or an antimony compound. No delay was observed in the polymerization time, and a predetermined stirring torque was reached. Let the obtained polyester masterbatch be A-2 to A-4, respectively.

Examples 5-7
In Example 5, except that the container to which the phosphorus compound was added was wrapped in a 0.015 mm-thick film and added, in Example 6, the pellets contained 10000 ppm of phosphorus compound as phosphorus atoms and had an intrinsic viscosity of 0.66. Except for the addition, in Example 7, the polyester was polymerized in the same manner as in Example 1 except that the phosphorus compound was added alone from the addition nozzle at the top of the polymerization can. No delay was observed in the polymerization time, and a predetermined stirring torque was reached. Let the obtained polyester masterbatch be A-5 to A-7, respectively.

Examples 8-10
Polyester was polymerized in the same manner as in Example 1 except that the addition amount of the phosphorus compound was changed. No delay was observed in the polymerization time, and a predetermined stirring torque was reached. In Example 10, a slight amount of foreign matter was observed in the polymer. Let the obtained polyester masterbatch be A-8-A-10, respectively.

Examples 11-15
A polyester was polymerized in the same manner as in Example 1 except that the addition type of the phosphorus compound was changed. No delay was observed in the polymerization time, and a predetermined stirring torque was reached. Let the obtained polyester masterbatch be A-11 to A-15, respectively.

Reference Examples 1-2
In Reference Example 1, polyester was polymerized in the same manner as in Example 1 except that the phosphorus compound was not added, and in Reference Example 2 as in Example 2 except that the phosphorus compound was not added. Let the obtained polyester be Z-1 to Z-2, respectively.

Example 16
The polyester Z-1 obtained in Reference Example 1 was pre-crystallized under a nitrogen atmosphere at 120 ° C. for 3 hours, dried at 150 ° C. for 20 hours under a reduced pressure of 10 Torr, and then tetrakis (2,4-di-t-butyl- 5-methylphenyl) [1,1-biphenyl] -4,4′-diylbisphosphonite is fed simultaneously to a vented twin screw extruder so that the phosphorus atom in the resulting polymer is 1000 ppm, and the temperature The mixture was melt-kneaded at 290 ° C. and a residence time of 5 minutes to obtain a polyester master batch B-1. No foreign matter was produced during the kneading, and no foaming was observed.

Examples 17-19
The polyester and the phosphorus compound were melt-kneaded in the same manner as in Example 16 except that the addition amount of the phosphorus compound was changed. No foreign matter was produced during the kneading, and no foaming was observed. Let the obtained polyester masterbatch be B-2-B-4, respectively.

Example 20
The polyester and the phosphorus compound were melt-kneaded in the same manner as in Example 16 except that the addition of the phosphorus compound was performed by melt-kneading with a pellet having an intrinsic viscosity of 0.66 containing 10,000 ppm of the phosphorus compound as a phosphorus atom. No foreign matter was produced during the kneading, and no foaming was observed. Let the obtained polyester masterbatch be B-5.

Examples 21-25
A polyester and a phosphorus compound were melt-kneaded in the same manner as in Example 16 except that the addition type of the phosphorus compound was changed. No foreign matter was produced during the kneading, and no foaming was observed. Let the obtained polyester masterbatch be B-6 to B-10, respectively.

Example 26
A polyester and a phosphorus compound were melt-kneaded in the same manner as in Example 16 except that the polyester was changed to Z-2. No foreign matter was produced during the kneading, and no foaming was observed. The obtained polyester master batches are designated as B-11.

Reference Example 1
The polyester Z-1 obtained in Reference Example 1 and the polyester masterbatch A-1 obtained in Example 1 were pre-crystallized under a nitrogen atmosphere at 120 ° C for 3 hours, and then dried at 150 ° C for 20 hours under a reduced pressure condition of 10 Torr. After that, it was fed to a vent type twin screw extruder so that Z-1 was 90% by weight and A-1 was 10% by weight, and kneaded at a temperature of 290 ° C. and a residence time of 5 minutes to obtain a polyester resin composition. Obtained. In the obtained polyester resin composition, the yellow tone of the color tone was suppressed, and the color tone brightness remained bright. Further, no foreign matter was generated during kneading, and no foaming was observed.

Reference Examples 2-15
Except for changing the polyester master batch to A-2 to A-15, melt kneading was performed in the same manner as in Reference Example 1 to obtain a polyester resin composition. In the obtained polyester resin composition, the yellow tone of the color tone was suppressed, and the color tone brightness remained bright. Further, in Reference Example 10, the generation of foreign matter was slightly observed during kneading, but no other foreign matter was generated and foaming was not observed at other levels.

Reference Examples 16-17
The polyester resin composition was melt kneaded in the same manner as in Reference Example 1 except that the feed ratio between the polyester Z-1 obtained in Reference Example 1 and the polyester master batch A-1 obtained in Example 1 was changed. Got. In the obtained polyester resin composition, the yellow tone of the color tone was suppressed, and the color tone brightness remained bright. Further, no foreign matter was generated during kneading, and no foaming was observed.

Reference Example 18
Except for changing the polyester Z-1 to the polyester Z-2 obtained in Reference Example 2, melt-kneading was performed in the same manner as in Reference Example 1 to obtain a polyester resin composition. In the obtained polyester resin composition, the yellow tone of the color tone was suppressed, and the color tone brightness remained bright. Further, no foreign matter was generated during kneading, and no foaming was observed.

Reference Examples 19-29
Except for changing the polyester master batch to B-1 to B-11, melt kneading was performed in the same manner as in Reference Example 1 to obtain a polyester resin composition. In the obtained polyester resin composition, the yellow tone of the color tone was suppressed, and the color tone brightness remained bright. Further, in Reference Example 22, the generation of foreign matter was slightly observed during kneading, but no other foreign matter was generated and foaming was not observed at other levels.

Comparative Example 1
A polyester was polymerized in the same manner as in Example 1 except that Solvent Blue 104 (manufactured by Clariant, Polysynthren Blue RBL, registered trademark No. 830265), which is a blue dye, was added instead of the phosphorus compound. No delay was observed in the polymerization time, and a predetermined stirring torque was reached. Let the obtained polyester masterbatch be C-1.

Comparative Examples 2-4
A polyester was polymerized in the same manner as in Example 1 except that the addition type of the phosphorus compound was changed. No delay was observed in the polymerization time, and a predetermined stirring torque was reached. However, in Comparative Examples 2 to 3, generation of black foreign matters was confirmed. In the obtained polyester, the master batches are C-2 to C-4, respectively.

Comparative Example 5
A polyester and a phosphorus compound were melt-kneaded in the same manner as in Example 16 except that Solvent Blue 104, which is a blue dye, was added instead of the phosphorus compound. No foreign matter was produced during the kneading, and no foaming was observed. Let the obtained polyester masterbatch be D-1.

Comparative Examples 6-8
A polyester and a phosphorus compound were melt-kneaded in the same manner as in Example 16 except that the addition type of the phosphorus compound was changed. In Comparative Example 6, the occurrence of black foreign matters was observed intensely during kneading. In Comparative Example 7, generation of black foreign matter was also confirmed. Let the obtained polyester masterbatch be D-2 to D-4, respectively.

Reference Comparative Examples 1-8
Polyester Z-1 obtained in Reference Example 1, polyester master batches C-1 to C-4 and D-1 to D-4 obtained in Comparative Examples 1 to 8, and preliminary crystallization at 120 ° C. for 3 hours in a nitrogen atmosphere And then dried at 150 ° C. for 20 hours under a reduced pressure of 10 Torr, and then fed to a bent twin screw extruder so that Z-1 is 90% by weight and the polyester masterbatch is 10% by weight, and the temperature is 290 ° C. The mixture was kneaded for 5 minutes to obtain a polyester resin composition. In Reference Comparative Examples 1 and 5, the yellowness of the polymer can be suppressed, but the color tone of the polymer is lowered. In Reference Comparative Examples 2-3 and 6-7, the yellowishness of the polymer is not improved, and the color brightness is lowered. In Reference Comparative Examples 4 and 8, there is no improvement in the yellow color of the polymer.

Claims (9)

A polyester masterbatch for color tone improvement, comprising at least one of the phosphorus compounds represented by Formula 1, Formula 2, and Formula 3 in an amount of 500 ppm to 5% by weight in terms of phosphorus atoms with respect to the polyester.

(In Formula 1, Formula 2, and Formula 3, R _{1 to} R ₆ each independently represent a hydroxyl group or a hydrocarbon group having 1 to 20 carbon atoms, and m is 0 or 1.) The polyester masterbatch for color tone improvement according to claim 1, wherein the phosphorus compound is a phosphorus compound represented by Formula 4.

(In the above formula 4, R _{7 to} R ₉ each independently represents a hydroxyl group or a hydrocarbon group having 1 to 10 carbon atoms, a + b + c is an integer of 0 to 5, and m is 0 or 1.) The polyester masterbatch for color tone improvement according to claim 1, wherein the phosphorus compound is a phosphorus compound represented by Formula 5.

(In the above formula 5, R _{10 to} R ₁₂ each independently represents a hydroxyl group or a hydrocarbon group having 1 to 10 carbon atoms, and m is 0 or 1.)   The polyester masterbatch for color tone improvement according to any one of claims 1 to 3, further comprising a titanium compound.   In a method for producing a polyester by polycondensation reaction of a dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof in the presence of a polycondensation catalyst under reduced pressure, the pressure reduction in the polymerization reactor is started. To at least one of phosphorus compounds represented by Formula 1, Formula 2, and Formula 3 until the polyester reaches a target degree of polymerization. A method for producing the polyester masterbatch for color tone improvement described.   The color tone improving agent according to any one of claims 1 to 4, wherein at least one of the phosphorus compounds represented by Formula 1, Formula 2, and Formula 3 and a polyester are melt-kneaded with an extruder. A method for producing a polyester masterbatch.   In a method for producing a polyester by polycondensation reaction of a dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof in the presence of a polycondensation catalyst under reduced pressure, the pressure reduction in the polymerization reactor is started. The polyester containing at least one phosphorus compound among the phosphorus compounds represented by Formula 1, Formula 2, and Formula 3 during the period from when the polyester reaches the target degree of polymerization. 5. A method for producing a polyester masterbatch for improving color tone according to any one of 4 above.   The polyester containing at least one phosphorus compound among the phosphorus compounds represented by Formula 1, Formula 2, and Formula 3 and the polyester are melt-kneaded with an extruder, according to any one of claims 1 to 4. A method for producing the polyester masterbatch for color tone improvement described.   A polyester resin having an improved color tone obtained by melt-kneading a polyester comprising a dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof with a polyester masterbatch for improving the color tone according to claim 1. Composition.