JP2010254801A - Polyester oligomer masterbatch for improving color and heat resistance, and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester oligomer masterbatch for improving color and heat resistance, a method for producing the same, and a method for producing a polyester with improved color and heat resistance by using the same. <P>SOLUTION: The polyester oligomer masterbatch for improving color and heat resistance includes a polyester oligomer and at least one phosphorus compound represented by formula (1), wherein the masterbatch contains the at least one phosphorus compound in an amount of 1-5 wt.% in terms of a phosphorus atom based on the amount of polyester oligomer and has an intrinsic viscosity is 0.02-0.2 dl/g. There is also provided a method for producing the masterbatch. In formula 1, R<SB>1</SB>and R<SB>2</SB>each independently represent a hydrogen atom or a 1-18C hydrocarbon group; and m represents 0 or 1. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a polyester oligomer master batch for improving color tone and heat resistance, a method for producing the same, and a method for producing polyester excellent in color tone and heat resistance using 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, decomposition reactions occur actively, and undesirable phenomena such as coloration of the polymer and, in some cases, generation of foreign matter occur.

  Usually, polyethylene terephthalate is produced using a polycondensation catalyst such as an antimony compound, a titanium compound or an aluminum compound. In this process, the decomposition reaction is accelerated, and the polymer may become yellowish. In addition, polyesters containing these metal catalysts have poor heat resistance and promote a decomposition reaction even during the molding process, causing the polymer to become yellowish, and in the case of fibers, thread breakage frequently occurs and deteriorates operability. There is. The fact that the polymer is yellowish is not preferable, for example, when using polyester as a fiber, since it impairs the commercial value of a fiber for clothing.

  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.

  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. Although it is possible to reduce the brightness and transparency of the polymer at the same time, it is not preferable. Reducing the brightness and transparency of a polymer is an undesirable characteristic when used as a film or bottle, for example. Moreover, this method does not improve the heat resistance. On the other hand, studies have been widely made to improve the color tone and heat resistance of a polymer by adding a phosphorus compound. In this method, the activity of the metal catalyst is suppressed by the phosphorus compound, the decomposition reaction is suppressed, and the color tone and heat resistance of the polymer are improved. For example, by kneading a polymer and a phosphorus compound or a polymer containing a phosphorus compound at a high concentration, the metal catalyst is deactivated to suppress coloring during molding and improve heat resistance (Patent Documents 2 and 3) Etc.

  Although this method can surely reduce the coloration during the molding process, it is not effective for the polymer that is markedly colored. 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. . In contrast, there is a method (Patent Document 4) in which a large amount of phosphorus can be added by adding a phosphorus compound in the production process of polyester, and the color tone and heat resistance of the polymer can be improved. In the method of directly adding phosphorus compounds during the reaction, low boiling point phosphorus compounds volatilize immediately under high temperature and reduced pressure, the content of phosphorus in the resulting polyester is lower than the target, sufficient color tone and heat resistance It was not possible to achieve the improvement. Conventional phosphorus compounds having a high boiling point do not have such a problem of phosphorus scattering, but these conventional compounds lower the yellowness (b value) and at the same time lightness (L value) and redness (a value). )) Is also lowered, resulting in a dark greenish polymer.

  Therefore, in order to efficiently add a low-boiling phosphorus compound into the polyester, a masterbatch containing a phosphorus compound in a polyester having a high degree of polymerization that has the same degree of polymerization as the obtained polyester and having a high degree of polymerization is prepared by melt-kneading. It was considered to add it during the polycondensation reaction. However, in this method, since the viscosity is high, the dispersibility of the phosphorus compound is poor, causing foreign matter, or when preparing a masterbatch, it is necessary to melt and knead at a high temperature of 280 ° C to 300 ° C. However, the phosphorus compound volatilized and the content of phosphorus in the masterbatch was lowered. Considering the poor addition efficiency, using a large excess of phosphorus compound, a high-concentration phosphorus-containing polyester high polymer master batch is produced, and the master batch is added during the polycondensation reaction. In the reaction system at 280 ° C. to 300 ° C. under high temperature and reduced pressure, the phosphorus compound volatilizes, the phosphorus content in the resulting polyester is low, and sufficient color tone and heat resistance cannot be achieved.

  In the present invention, diligent investigations have been made to improve the above-described problems. As a result, if a masterbatch is created using a polyester oligomer having a low degree of polymerization, the viscosity is low, so the dispersibility of the phosphorus compound is good, and the temperature at the time of producing the masterbatch can be suppressed to 250 ° C., Scattering of low-boiling phosphorus compounds can also be suppressed, and a high-concentration master batch can be obtained efficiently. Furthermore, even if this high-concentration phosphorus-containing polyester oligomer master batch is added during the polycondensation reaction, it is possible to obtain a polyester having improved color tone and heat resistance by suppressing the scattering of the phosphorus compound and increasing the phosphorus content. I understood that. The mechanism of this scattering suppression effect is not known in detail at present, but is considered as follows. That is, since the concentration of the terminal hydroxyl group per unit mass is higher in the oligomer than in the polymer having a high degree of polymerization, the terminal hydroxyl group and the phosphorus compound undergo transesterification, the phosphorus compound is immobilized at the oligomer end, and the boiling point rises. It is thought that the cause is that it becomes difficult to volatilize.

    Furthermore, as a low-boiling phosphorus compound, if a polyester oligomer masterbatch containing 1 to 5% by weight in terms of phosphorus atom among at least one phosphorus compound represented by the formula (1) is used, the lightness (L value) and Only the yellowness (b value) can be lowered without reducing the redness (a value). The mechanism of this effect is not completely clarified at present, but 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 change the absorption wavelength of the colored component. thinking. This is essentially different from the effect of the conventional phosphorus compound, or at least not fully achieved by the conventional phosphorus compound.

  As described above, in the present invention, as a result of intensive investigations on improving the above problems, a low-boiling phosphorus compound having a specific structure that could not be efficiently added to a polymer by a conventional method is efficiently added as a polyester oligomer master batch. The inventors have found a method and obtained the knowledge that the object of the present invention can be achieved.

JP 2000-80172 A (Claims) JP 2006-152066 A (Claims) JP 2006-45455 A (Claims) JP 2008-255321 A (Claims)

  An object of the present invention is to eliminate the above-mentioned conventional problems, that is, a polyester oligomer masterbatch for improving the color tone and heat resistance of a polymer and a method for producing the same, and a method for producing a polyester having improved color tone and heat resistance using the same. Is to provide.

  The subject of the present invention is that the intrinsic viscosity is 0.05 to 0.2 dl / g, and at least one of the phosphorus compounds represented by the formula (1) is contained in an amount of 1 to 5% by weight in terms of phosphorus atoms. This can be achieved by the polyester oligomer masterbatch for improving the characteristic color tone and heat resistance.

  (In the above formula (1), R1 and R2 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, and m represents 0 or 1.)

  The intrinsic viscosity of the present invention is 0.05 to 0.2 dl / g, and contains at least one of phosphorus compounds represented by the formula (1) in an amount of 1 to 5% by weight in terms of phosphorus atoms. By adding a polyester oligomer master batch for improving the color tone and heat resistance in the polycondensation step, the color tone and heat resistance of the polyester can be dramatically improved. This polyester oligomer masterbatch can solve the problems of polyester color tone and heat resistance, which are problems in the production of molded articles for fibers, films and bottles.

    Hereinafter, the polyester oligomer masterbatch of the present invention, the method for producing a polyester oligomer masterbatch, and the method for producing a polyester having improved color tone and heat resistance using the polyester oligomer masterbatch will be specifically described.

  The polyester oligomer masterbatch for improving the color tone and heat resistance of the present invention has an intrinsic viscosity of 0.05 to 0.2 dl / g, and at least one of the phosphorus compounds represented by the formula (1) is 1 in terms of phosphorus atoms. It is essential to contain ~ 5% by weight.

  Specifically, as the phosphorus compound represented by the formula (1), as a pentavalent phosphorus compound, phenylphosphonic acid, phenylphosphonic acid dimethyl, phenylphosphonic acid diethyl, phenylphosphonic acid dipropyl, phenylphosphonic acid dibutyl, phenylphosphonic acid dipentyl , Phenyl phosphonate dihexyl, phenyl phosphonate diheptyl, phenyl phosphonate dioctyl, phenyl phosphonate didecyl, phenyl phosphonate didodecyl, phenyl phosphonate dioctadecyl, phenyl phosphonate diphenyl, phenyl phosphonate dicyclohexyl, etc. As phenyl phosphonous acid, phenyl phosphonous acid dimethyl, phenyl phosphonous acid diethyl, phenyl phosphonous acid dipropyl, phenyl phosphonous acid dibutyl, Dipentyl phosphite, dihexyl phenyl phosphonite, diheptyl phenyl phosphonite, dioctyl phenyl phosphonite, didecyl phenyl phosphonite, didodecyl phenyl phosphonite, dioctadecyl phenyl phosphonite, diphenyl phenyl phosphonite, phenyl Examples include phosphonous acid dicyclohexyl.

  The polyester oligomer of the present invention is a polyester having a low degree of polymerization and has an intrinsic viscosity of 0.05 to 0.2 dl / g. If it is lower than 0.05 dl / g, in the polyester production method using this master batch, when the master batch is added after the start of the polycondensation reaction until the polymerization reaches the target degree of polymerization. , Polyester depolymerization (polyester main chain cleavage reaction) proceeds. On the other hand, if the intrinsic viscosity is higher than 0.2 dl / g, the melt viscosity of the reaction system becomes high and the dispersibility of the phosphorus compound is deteriorated, so that foreign matter is generated or the phosphorus compound is scattered, resulting in a low phosphorus content. In addition, this is not economically preferable, and the scattered phosphorus compound may be distilled off to the decompression line and clogged.

  When the content of the phosphorus compound in the polyester oligomer masterbatch of the present invention is less than 1% by weight in terms of phosphorus atoms with respect to the polyester oligomer, the polycondensation reaction is started in the polyester production method using this masterbatch. When a masterbatch is added during the period from when the polymerization reaches the target degree of polymerization, it is necessary to add a large amount of oligomers, which promotes depolymerization of the polyester (breaking reaction of the polyester main chain). Resulting in. On the other hand, if it exceeds 5% by weight, foreign substances derived from the phosphorus compound are generated, or the phosphorus compound is scattered and the phosphorus addition efficiency is deteriorated, which is not economically preferable. It may end up.

  The polyester oligomer masterbatch of the present invention and the polyester obtained using the same are polyesters obtained from an aromatic dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof, and as an aromatic dicarboxylic acid component Terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyl-4,4′-dicarboxylic acid and its methyl ester, ethyl ester, hydroxyethyl ester and the like. Examples of the diol component include ethylene glycol, 1 , 3-propanediol, 1,4-butanediol, cyclohexanedimethanol and the like.

  Among them, polyethylene terephthalate using terephthalic acid as an aromatic dicarboxylic acid component and ethylene glycol as a diol component or a polyester copolymer mainly containing an ethylene terephthalate unit is preferable.

  The following method is mentioned as a manufacturing method of the polyester oligomer masterbatch of this invention. In the esterification reaction or transesterification reaction with the aromatic dicarboxylic acid or its ester-forming derivative and the diol or its ester-forming derivative, it is represented by the formula (1) at any stage until the end of the reaction. The method of adding at least 1 sort (s) among phosphorus compounds is mentioned. In this case, the phosphorus compound may be added before the start of the reaction, may be added during the reaction, may be added after the reaction, and before solidification, or the oligomer is solidified once after the reaction is completed. The obtained polyester oligomer may be melted again and then added. Preferably, it is added before solidification after completion of the reaction. In addition, the completion | finish of reaction here represents that water as a by-product stops distilling in the case of esterification reaction, and represents that methanol as a by-product stops distilling in the case of transesterification reaction, Specifically, it represents the time when the column top temperature of the rectifying column is lower by about 20 ° C. than its boiling point, that is, when it is 80 ° C. or lower for water and 40 ° C. or lower for methanol.

  When adding a phosphorus compound in the above production method, if a large amount of a diol component such as ethylene glycol is brought in and added, the depolymerization of the polyester (polyester main chain cleavage reaction) proceeds, so the phosphorus compound alone Is preferably added. At this time, the phosphorus compound may be added in several portions, or may be continuously added with a feeder or the like.

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

Polyethylene terephthalate oligomers are usually produced by one of the following processes.
That is, (A) a process for obtaining a low polymer by direct esterification reaction using terephthalic acid and ethylene glycol as raw materials, and (B) a process for obtaining a low polymer by transesterification using dimethyl terephthalate and ethylene glycol as raw materials. . Here, the esterification reaction proceeds even without a catalyst, but a titanium compound may be added as a catalyst. In the transesterification reaction, a compound such as magnesium, manganese, calcium, cobalt, zinc, lithium and titanium is used as a catalyst. Before solidifying the oligomer after completion of the reaction (A), after completion of the reaction or after completion of the reaction (B), at least one of the phosphorus compounds represented by the formula (1) is 1 to 5 weights in terms of phosphorus atoms. The polyester oligomer masterbatch of this invention can be obtained by adding so that it may become content of%.

  As a method for producing a polyester excellent in color tone and heat resistance using the polyester oligomer masterbatch of the present invention, the following two methods may be mentioned.

  The first is polycondensation in a process for producing a polyester by polycondensation of an aromatic dicarboxylic acid or its ester-forming derivative and a diol or its ester-forming derivative via an esterification reaction or transesterification reaction in the presence of a catalyst. There is a method in which the polyester oligomer masterbatch of the present invention is added after the reaction is started until the polymerization reaches the target degree of polymerization. In this case, if a large amount of a diol component such as ethylene glycol is brought in and added, the depolymerization of the polyester (polyester main chain cleavage reaction) proceeds. It is preferable to add it by filling a container made of a polymer which can be dissolved or melted and is substantially the same component as the polymer obtained in the present invention.

  The container referred to in the present invention is not limited as long as the master batch can be collected, and includes, for example, an injection molded container having a lid and a stopper, or a sheet or film formed into a bag shape by sealing or sewing. The container is more preferably provided with an air vent. When a master batch is added to a container equipped with an air vent, even if it is added to the polymerization reactor under vacuum conditions, the container ruptures due to air expansion and the master batch flows out to the decompression line, or the upper part of the polymerization reactor. And can be reliably added to the polymer 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 masterbatch is sealed or added. For this purpose, a material having a thickness of 10 to 500 μm and uniform thickness is preferable.

  As a second method, a polyester obtained by polycondensation of aromatic dicarboxylic acid or its ester-forming derivative and diol or its ester-forming derivative and the polyester oligomer masterbatch of the present invention are melt-kneaded in a twin-screw extruder. The method of doing is mentioned.

  In either case, when adding the master batch, it may be added in several portions, or may be continuously added with a feeder or the like. Moreover, it is preferable that the polyester oligomer masterbatch and the obtained polyester are substantially the same component polymers.

  As the polycondensation catalyst, a titanium compound, an aluminum compound, an antimony compound, or the like is used. Among these, a titanium compound that can be added in a small 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, the titanium compound is obtained by hydrolysis of titanium alkoxide, titanium alkoxide such as titanium complex, tetra-i-propyl titanate, tetra-n-butyl titanate, tetra-n-butyl titanate tetramer, tetra-t-butyl titanate. And titanium oxide, titanium acetylacetonate, and the like. Among these, a titanium complex containing a polycarboxylic acid and / or hydroxycarboxylic acid and / or a polyhydric alcohol as a chelating agent is preferable from the viewpoint of thermal stability and color tone of the polymer. As chelating agents for titanium compounds, polyvalent carboxylic acids include phthalic acid, trimellitic acid, trimesic acid, hemititic acid, pyromellitic acid, and the like, and hydroxycarboxylic acids include lactic acid, citric acid, and the like. Examples of the monohydric alcohol include mannitol and tripentaerythritol. 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 the aluminum carboxylate include aluminum acetate, aluminum propionate, aluminum stearate, aluminum benzoate, aluminum lactate, and aluminum citrate. Examples of the inorganic acid salt of aluminum include aluminum hydroxide and aluminum carbonate. Examples of the aluminum alkoxide include aluminum ethoxide, aluminum isopropoxide, and aluminum butoxide. Examples of the aluminum chelate compound include aluminum acetylacetonate, aluminum acetylacetate, and aluminum ethylacetoacetate. Examples thereof include dialuminum trioxide. 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 and the like, and antimony alkoxide includes antimony tri-n-butoxide, antimony triethoxy. And the like. Of these, antimony oxide is preferable, and antimony trioxide is particularly preferable. These antimony 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.

  In addition, the polyester oligomer masterbatch of the present invention and the polyester obtained by using the same are provided with 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. It may be added.

  The polyester obtained by adding the polyester oligomer masterbatch of the present invention has improved color tone and heat resistance, the color tone in the chip shape is Hunter value, L value is 70-78, a value is -3-2, It is preferable that b value exists in the range of -5-1. Moreover, it is preferable from the point of the heat resistance of a polymer that (DELTA) b value 290 used as a heat resistance parameter | index is the range of -3-3. The smaller this value, the less the decomposition and coloring due to thermal deterioration, and the better the thermal stability. If this value exceeds 5, the polymer will be discolored during spinning or molding, which will have a significant effect on quality.

  Although the example of a polyethylene terephthalate is described as a specific example of the manufacturing method of polyester excellent in color tone and heat resistance using the polyester oligomer masterbatch of this invention, 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. In this polycondensation reaction, the intrinsic viscosity is 0.02 to 0.2 dl / g at any stage from the start of the pressure reduction in the polymerization reactor until the polyester reaches the target degree of polymerization. By adding a polyester oligomer masterbatch characterized by containing 1 to 5% by weight of at least one of the phosphorus compounds represented by the formula (1) in terms of phosphorus atoms with respect to the polyester oligomer, the color tone and Polyethylene terephthalate having excellent heat resistance can be obtained.

  The above reaction can be applied to a batch, semi-batch, or continuous system.

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.
-Phosphorus content Measured with a fluorescent X-ray analyzer (FLX) manufactured by Rigaku Corporation.
(2) Intrinsic viscosity of polymer [η]
0.1 g of sample was dissolved in 10 mL of orthochlorophenol and measured at 25 ° C.
The Ubbelohde viscometer was used as the viscometer, and the specific viscosity ηsp was determined from the following equation (2).

ηsp = (η−η0) / η0 (2)
(Η represents the solution viscosity, and η0 represents the solvent viscosity.)
Subsequently, the intrinsic viscosity [η] was determined using the following formula (3).

[Η] = {− 1+ (1 + 4K · ηsp) ^1/2 } / 2K · C (3)
(K represents the Huggins constant, and in the case of polyethylene terephthalate, it is 0.343. C represents the sample concentration (g / dl).)
(3) 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, a, b value). L value is lightness, a value is redness index, and b value is an index of yellowness. When the L value is large, the lightness is high, and when the a value is large, the redness is high. If the b value is large, it means that the yellowness is high. To improve the color tone in the present invention means to reduce the b value while suppressing the decrease of the L value, and to make the a value close to 0.
(4) Δb value 290
The polyester chip was dried under reduced pressure at 150 ° C. for 12 hours, then heated and melted at 290 ° C. for 60 minutes in a nitrogen atmosphere, and then the color tone was measured by the method (3). As measured.

Manufacturing method of polyester masterbatch Manufacturing method A
After completion of the esterification or transesterification reaction, a method for producing a polyester oligomer master batch by adding a phosphorus compound before solidification was designated as Production Method A.

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 was sequentially supplied over 4 hours, and after the completion of supply, further esterification reaction was carried out, and when the top temperature of the rectifying column became 80 ° C. or less, the reaction was completed. did.

  To 20.2 kg of the obtained esterification reaction product, 6.2 kg of diethyl phenylphosphonate (so as to be 3.4 wt% in terms of phosphorus atoms with respect to the obtained polyester oligomer master batch) was added from the top of the reaction can. . Subsequently, the mixture was stirred at 250 ° C., and discharged and cooled after 30 minutes to obtain a polyester oligomer master batch M-1. When the phosphorus content was measured with a fluorescent X-ray analyzer (FLX), it was 2.5 wt% in terms of phosphorus atoms. The intrinsic viscosity [η] was 0.10.

Examples 2-7
Polyester oligomer master batches M-2 to 7 were obtained in the same manner as in Example 1 except that the type and addition amount of the phosphorus compound were changed as shown in Table 1. Each phosphorus content and intrinsic viscosity [η] are summarized in Table 1.
Manufacturing method B
After completion of the esterification or transesterification reaction, a method of producing a polyester oligomer master batch by discharging and solidifying by cooling and adding the phosphorus compound after melting the obtained polyester oligomer again was designated as Production Method B.

Example 8
The esterification reaction was carried out in the same manner as in Example 1, and the reaction was further continued for 1 hour from the time when the top temperature of the rectifying column became 80 ° C. or lower, and then the mixture was discharged and cooled. The obtained esterification reaction product (20.2 kg) was again melted in an esterification reaction vessel maintained at a temperature of 250 ° C. and a pressure of 1.2 × 10 ⁵ Pa to obtain 11.0 kg of dioctyl phenylphosphonate (obtained). The polyester oligomer masterbatch was added from the top of the reaction can so that the amount was 2.9 wt% in terms of phosphorus atoms. Subsequently, the mixture was stirred at 250 ° C., and discharged and cooled after 30 minutes to obtain a polyester oligomer master batch M-8. When the phosphorus content was measured with a fluorescent X-ray analyzer (FLX), it was 2.6 wt% in terms of phosphorus atoms. The intrinsic viscosity [η] was 0.15.

Example 9
In the esterification reaction, a polyester oligomer master batch M-9 was obtained in the same manner as in Example 8 except that the reaction was further performed for 2 hours from the time when the column top temperature of the rectification column became 80 ° C. or lower. When the phosphorus content was measured with a fluorescent X-ray analyzer (FLX), it was 2.6 wt% in terms of phosphorus atoms. The intrinsic viscosity [η] was 0.20.

Example 10
During the esterification reaction, when the top temperature of the rectifying column becomes 80 ° C. or lower, the mixture is discharged and cooled, and instead of dioctyl phenylphosphonate, 8.9 kg of phenylphosphonate diphenyl (based on the obtained polyester oligomer master batch) Thus, a polyester oligomer master batch M-10 was obtained in the same manner as in Example 8, except that 3.1 wt% in terms of phosphorus atom was added. When the phosphorus content was measured with a fluorescent X-ray analyzer (FLX), it was 2.7 wt% in terms of phosphorus atoms. The intrinsic viscosity [η] was 0.11.
Manufacturing method C
A method for producing a polyester oligomer master batch by adding a phosphorus compound before the start of the esterification reaction and then carrying out an esterification reaction was designated as production method C.

Example 11
About 10 kg of bis (hydroxyethyl) terephthalate was charged in advance, in an esterification reaction vessel maintained at a temperature of 250 ° C. and a pressure of 1.2 × 10 ⁵ Pa, 11.0 kg of dioctyl phenylphosphonate (into the resulting polyester oligomer master batch) From the upper part of the reaction vessel, 8.3 kg of high-purity terephthalic acid (manufactured by Mitsui Chemicals) and 3.5 kg of ethylene glycol (manufactured by Nippon Shokubai Co., Ltd.) are added. Are sequentially supplied over 4 hours, and after the completion of the supply, the esterification reaction is further carried out, and when the top temperature of the rectifying column becomes 80 ° C. or lower, the mixture is discharged and cooled to obtain a polyester oligomer master batch M-11. It was. When the phosphorus content was measured with a fluorescent X-ray analyzer (FLX), it was 2.6 wt% in terms of phosphorus atoms. The intrinsic viscosity [η] was 0.09.

Manufacturing method A
Example 12
15 kg of dimethyl terephthalate (manufactured by SK Chemical Co., Ltd.) and 9.3 kg of ethylene glycol (manufactured by Nippon Shokubai Co., Ltd.) were charged, and the temperature was gradually raised to conduct a transesterification reaction at a temperature of 240 ° C. The reaction was terminated when the top temperature of the rectification column became 40 ° C. or lower.

  10.2 kg of dioctyl phenylphosphonate (so as to be 2.9 wt% in terms of phosphorus atoms with respect to the obtained polyester oligomer master batch) was added to 19.2 kg of the obtained transesterification reaction product from the upper part of the reaction can. . Subsequently, the mixture was stirred at 240 ° C. and discharged and cooled after 30 minutes to obtain a polyester oligomer master batch M-12. When the phosphorus content was measured with a fluorescent X-ray analyzer (FLX), it was 2.6 wt% in terms of phosphorus atoms. The intrinsic viscosity [η] was 0.06.

Examples 13-17
Polyester oligomer master batches M-13 to 17 were obtained in the same manner as in Example 12 except that the type and addition amount of the phosphorus compound were changed as shown in Table 1. Each phosphorus content and intrinsic viscosity [η] are summarized in Table 1.

Manufacturing method B
Example 18
A transesterification reaction was carried out in the same manner as in Example 12. When the top temperature of the rectifying column became 40 ° C. or lower, the reaction was terminated, and the mixture was discharged and cooled. 19.2 kg of the obtained transesterification reaction product was again put in an ester exchange reaction tank maintained at a temperature of 240 ° C. and melted, and 13.5 kg of didedecyl phenylphosphonate (phosphorus atoms with respect to the obtained polyester oligomer masterbatch). Was added from the top of the reactor. Subsequently, the mixture was stirred at 240 ° C., and discharged and cooled after 30 minutes to obtain a polyester oligomer master batch M-18. When the phosphorus content was measured with a fluorescent X-ray analyzer (FLX), it was 2.2 wt% in terms of phosphorus atoms. The intrinsic viscosity [η] was 0.06.

Example 19
A polyester oligomer master batch M-19 was obtained in the same manner as in Example 18 except that the type and addition amount of the phosphorus compound were changed as shown in Table 1. When the phosphorus content was measured with a fluorescent X-ray analyzer (FLX), it was 2.0 wt% in terms of phosphorus atoms. The intrinsic viscosity [η] was 0.06.

Manufacturing method A
Comparative Example 1
A polyester is obtained in the same manner as in Example 1 except that 20.2 g is added to the polyester oligomer masterbatch to obtain a dye, Solvent Blue 45 (manufactured by Clariant Japan) instead of the phosphorus compound. An oligomer master batch C-1 was obtained. Intrinsic viscosity [η] was 0.11.

Manufacturing method D
After completion of esterification, polycondensation is carried out in the presence of a catalyst. When 85% of the predetermined stirring torque is reached, a phosphorus compound is added, and polymerization is performed until the predetermined torque is reached, thereby producing a polyester polymer master batch. Was made into the manufacturing method D.

Comparative Example 2
The esterification reaction was carried out in the same manner as in Example 1, and 10.2 kg of the obtained esterification reaction product was transferred to a polycondensation tank.

To the esterification reaction product, an ethylene glycol mixed solution of 0.8 g of magnesium acetate (10 ppm in terms of magnesium atom relative to the polymer) and 0.8 g of cobalt acetate (20 ppm in terms of cobalt atom relative to the polymer), and the polymer 30 minutes before adding a citrate chelate titanium compound equivalent to 5 ppm in terms of titanium atom, the mixture was premixed 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. Dioctyl phenylphosphonate (10.4 kg) was added from the upper part of the reaction vessel after adding 2.9 wt% in terms of phosphorus atom to the obtained polyester polymer masterbatch. 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 polymer master batch is designated as C-2. When the phosphorus content was measured with a fluorescent X-ray analyzer (FLX), it was as low as 0.2 wt% in terms of phosphorus atoms. The intrinsic viscosity [η] was 0.66.

Comparative Example 3
A polyester polymer master batch C-3 was obtained in the same manner as in Comparative Example 2 except that the addition amount of the phosphorus compound was changed as shown in Table 1. The phosphorus content was measured with a fluorescent X-ray analyzer (FLX) and found to be 2.4 wt% in terms of phosphorus atoms. The intrinsic viscosity [η] was 0.66.

Example 20 for producing polyester using polyester oligomer masterbatch
In a container having a thickness of 0.2 mm and an internal volume of 2000 cm ³ made by injection-molding a polyethylene terephthalate sheet, polyester oligomer masterbatch M-1 (phosphorus content 2.5 wt%) is used instead of dioctyl phenylphosphonate. Polymer pellets were obtained in the same manner as in Comparative Example 2, except that .2 g (30 ppm in terms of phosphorus atom with respect to the obtained polyester polymer masterbatch) was added and added from the top of the reaction can.

  The time from the start of decompression to the arrival of the predetermined stirring torque was 2 hours and 51 minutes. Further, when the phosphorus content in the obtained polyester was measured with a fluorescent X-ray analyzer (FLX), it was 27 ppm in terms of phosphorus atoms, and it was found that phosphorus was hardly volatilized and remained in the polyester. . Further, a polymer having good color tone and heat resistance was obtained.

Examples 21-38
A polyester was produced in the same manner as in Example 20 except that the polyester oligomer master batch was changed as shown in Tables 2 and 3. All of the obtained polymers were excellent in color tone and heat resistance. The results are summarized in Table 2 and Table 3.

Examples 39-42
A polyester was produced in the same manner as in Example 20 except that the type, addition amount and polyester oligomer master batch of the polycondensation catalyst were changed as shown in Table 3. All of the obtained polymers were excellent in color tone and heat resistance. The results are summarized in Table 3.

Examples 43 and 44
A polyester was produced in the same manner as in Example 20 except that the additive amount and the type of polyester oligomer master batch were changed as shown in Table 3. All of the obtained polymers were excellent in color tone and heat resistance. The results are summarized in Table 3.

Example 45
A polyester was produced in the same manner as in Example 20, except that the type of polyester oligomer master batch and the container to which it was added were changed to a film having a thickness of 0.015 mm. The obtained polymer was excellent in color tone and heat resistance. The results are summarized in Table 3.

Example 46
A polyester was produced in the same manner as in Example 20, except that the type of polyester oligomer master batch and the polyester oligomer master batch were added independently from the addition nozzle at the top of the polymerization can. The obtained polymer was excellent in color tone and heat resistance. The results are summarized in Table 3.

Example 47
The esterification reaction was carried out in the same manner as in Comparative Example 2, and 10.2 kg of the obtained esterification reaction product was transferred to a polycondensation tank. To the esterification reaction product, an ethylene glycol mixed solution of magnesium acetate and cobalt acetate, a mixture of a citrate chelate titanium compound, and titanium oxide particles were added in the same manner as in Comparative Example 2. 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. 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 40 minutes. 1.92 kg of this polymer pellet was pre-crystallized under a nitrogen atmosphere at 120 ° C. for 3 hours, dried at 150 ° C. for 20 hours under a reduced pressure condition of 10 Torr, and then dried at 100 ° C. for 20 hours under a reduced pressure condition of 10 Torr. 3 was simultaneously fed to a bent twin screw extruder so that the phosphorus atom in the resulting polymer was 30 ppm (2.2 g), and melt-kneaded at a temperature of 290 ° C. and a residence time of 5 minutes to obtain a polyester. . No foreign matter was produced during the kneading, and no foaming was observed. The obtained polymer was excellent in color tone and heat resistance. The results are summarized in Table 3.

Comparative Examples 4-6
A polyester was produced in the same manner as in Example 20 except that the type and addition amount of the polyester oligomer master batch were changed as shown in Table 4. In either case, phosphorus was hardly contained. In Comparative Example 4, a polymer having a low brightness was obtained, and in Comparative Examples 5 and 6, a yellowish polymer was obtained. In either case, the heat resistance was poor. The results are summarized in Table 4.

Comparative Examples 7 and 9-13
A polyester was produced in the same manner as in Example 20 except that the phosphorus compound shown in Table 4 was added alone instead of the polyester oligomer masterbatch. The polymer obtained in Comparative Example 7 was a polymer with little phosphorus remaining and poor color tone and heat resistance. The polymers obtained in Comparative Examples 9 to 13 had a high phosphorus content and were all excellent in heat resistance. However, the polymers obtained in Comparative Examples 9 to 11 were dark and light green. Further, the polymers obtained in Comparative Examples 12 and 13 were bright, but a yellowish polymer was obtained. The results are summarized in Table 4.

Comparative Examples 8 and 14
As shown in Table 4, instead of polyester oligomer master batch M-3, Comparative Example 8 was similar to Example 47 except that dioctyl phenylphosphonate was added alone, and normal phosphoric acid was not added to the container alone. To obtain polyester. In either case, foaming was intense. Further, almost no phosphorus remained in the polymer obtained in Comparative Example 8, and a polymer having poor color tone and heat resistance was obtained. The polymer obtained in Comparative Example 14 contained 24 ppm of phosphorus, and was a yellowish polymer with good heat resistance. The results are summarized in Table 4.

Comparative Example 15
The esterification reaction was performed in the same manner as in Comparative Example 2, and 10.2 kg of the obtained esterification reaction product was transferred to a polycondensation tank.

  In the same manner as in Comparative Example 2, a mixed solution of magnesium acetate and cobalt acetate in ethylene glycol and a mixture of citrate chelate titanium compound were added to the esterification reaction product. After 5 minutes, 9.2 g of tetraethylbiphenyl-4,4′-diylphosphonate (manufactured by Johoku Chemical Co., Ltd.) (so that the resulting polymer was 30 ppm in terms of phosphorus atoms) and an ethylene glycol slurry of titanium oxide particles were prepared. Further, 0.3% by weight in terms of titanium oxide particles was added to the polymer. After another 5 minutes, the reaction system was decompressed to initiate the reaction. The temperature in the reactor was gradually raised 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. Thereafter, the polymerization reached a peak, and the target torque was not reached.

Comparative Examples 16-18
The same procedure as in Comparative Example 15 was carried out except that the type and addition amount of the phosphorus compound were changed as shown in Table 4. In either case, when the predetermined stirring torque is reached, the reaction system is purged with nitrogen and returned to normal pressure to stop the polycondensation reaction, discharged into a strand, cooled, and immediately cut to obtain polymer pellets. It was. All the polymers had low phosphorus content, and a polymer with poor color tone and heat resistance was obtained. The results are summarized in Table 4.

Comparative Examples 19 and 20
The same procedure as in Comparative Example 15 was carried out except that the polycondensation catalyst type, addition amount, phosphorus compound type, and addition amount were changed as shown in Table 4. In either case, when the predetermined stirring torque is reached, the reaction system is purged with nitrogen and returned to normal pressure to stop the polycondensation reaction, discharged into a strand, cooled, and immediately cut to obtain polymer pellets. It was. All the polymers were inferior in color tone and heat resistance. The results are summarized in Table 4.

Claims (3)

Inherent viscosity is 0.05 to 0.2 dl / g, and contains at least one of phosphorus compounds represented by the formula (1) in an amount of 1 to 5% by weight in terms of phosphorus atoms, and color tone and heat resistance Polyester oligomer masterbatch for improvement.

(In the above formula (1), R1 and R2 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, and m represents 0 or 1.)   In the esterification reaction or transesterification reaction with an aromatic dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof, phosphorus represented by the formula (1) at any stage until the end of the reaction The method to manufacture the polyester oligomer masterbatch for color tone and heat resistance improvement of Claim 1 by adding at least 1 sort (s) among compounds.   2. The method for producing a polyester by polycondensation reaction of an aromatic dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof in the presence of a polycondensation catalyst. A method for producing a polyester with improved color tone and heat resistance, characterized in that an oligomer masterbatch is added between the start of depressurization in a polycondensation reactor and the polyester reaching a target degree of polymerization. .