JP2010126614A - Polyester polycondensation catalyst, and polyester production method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polycondensation catalyst that can give polyester, preventing increase in filtration pressure due to foreign matter caused by a catalyst, reducing contamination on a mold during molding, resulting in good spinning property and having excellent thermal stability and color tone of polymers compared to conventional products, and to provide a polyester production method using the catalyst. <P>SOLUTION: The polyester polycondensation catalyst is obtained by reacting a titanium compound with tripentaerythritol in a molar ratio of titanium atoms to tripentaerytyritol of 1:1 to 1:2. The production method of polyester is carried out by using the above catalyst. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a polyester polycondensation catalyst. More specifically, in the production of polyester, there is no increase in filtration pressure due to the catalyst-derived foreign matter used during polymerization, the yarn production is good, and the polyester has excellent thermal stability and color tone compared to conventional products. It is related with the polyester polycondensation catalyst which is hard to deactivate during reaction.

  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 an ester-forming derivative thereof and ethylene glycol. In a commercial process for producing a high molecular weight polymer, an antimony compound is widely used as a polycondensation catalyst. However, polymers containing antimony compounds have some undesirable properties as described below.

  For example, it is known that when a polymer obtained using an antimony catalyst is melt-spun into a fiber, a residue of the antimony catalyst is deposited around the die hole. It is believed that the accumulation of the antimony catalyst residue occurs because the antimony compound in the polymer is transformed near the die, and after a part is vaporized and dissipated, a component mainly composed of antimony remains in the die. As this deposition progresses, it becomes a cause of defects in the filament, so that it needs to be removed in a timely manner. In addition, the antimony catalyst residue in the polymer tends to be relatively large particles, and it becomes a foreign substance, causing an increase in the filtration pressure of the filter during molding, causing yarn breakage during spinning or film tearing during film formation, etc. It has an unfavorable defect and contributes to a decrease in operability.

  In view of the above background, there is a demand for polyesters that do not contain antimony. Therefore, germanium compounds are known when the role of the polycondensation catalyst is required for compounds other than antimony compounds, but germanium compounds are difficult to use for general purposes because they have a small reserve and rare value.

  On the other hand, studies using a titanium compound as a polycondensation catalyst have been actively conducted for this problem. Since the titanium compound has a higher catalytic activity than the antimony compound, the desired catalytic activity can be obtained with a small amount of addition, and generation of foreign particles and contamination of the base can be suppressed. However, when a titanium compound is used as a polycondensation catalyst, side reactions such as a thermal decomposition reaction and an oxidative decomposition reaction are promoted due to its high activity, resulting in a problem that the thermal stability is deteriorated and the polymer is colored yellow. It is not preferable that the polymer is yellowish, for example, when polyester is used as the fiber, since the commercial value of the fiber for clothing is impaired. As described above, antimony catalyst is used to reduce the occurrence of foreign matters due to the catalyst and mold contamination during molding, and to obtain polyester with dramatically improved thermal stability and color tone compared to conventional products. Therefore, it was necessary to solve the contradictory problem of using a titanium compound as a polycondensation catalyst and suppressing side reactions without impairing the polycondensation reaction activity.

  On the other hand, as a polycondensation catalyst, a composition comprising a titanium compound, a phosphorus compound and an amine (Patent Document 1), a reaction product of the titanium compound, the phosphorus compound and an aromatic polyvalent carboxylic acid or an anhydride thereof (Patent Document 2). ~ 4) have been proposed. Although these methods can reduce foreign matters caused by the catalyst, the color tone of the obtained polymer is not sufficient. Accordingly, there is a need for further improvements in titanium compounds.

  In the first place, the coloring of the polyester and the deterioration of the heat resistance are caused by a side reaction of the polyester polymerization as clearly shown in the saturated polyester resin handbook (Nikkan Kogyo Shimbun, first edition, pages 178 to 198). In the side reaction of the polyester, carbonyl oxygen is activated by a metal catalyst having Lewis acidity, and β hydrogen is extracted, thereby generating a vinyl end group component and an aldehyde component. As a result of such a side reaction, the polymer is colored yellow and the main chain ester bond is cleaved, resulting in a polymer having poor heat resistance. In particular, when a titanium compound is used as a polycondensation catalyst, since the side reaction due to heat is strongly activated, a large amount of vinyl end group components and aldehyde components are generated, resulting in a yellow colored polymer having poor heat resistance. The coloring mechanism is not completely clarified at present, but it is presumed that the coloring is caused by specific coordination between the titanium compound and impurities. Therefore, if a ligand that clathrates titanium is used, the specific coordination between the titanium compound and the impurity can be suppressed, so that coloring can be suppressed and the Lewis acidity of the titanium compound can be weakened. It was hypothesized that the thermal stability of the polymer would be better because it suppresses the activation of carbonyl oxygen and consequently the cleavage of the main chain ester bond and the generation of vinyl end group components and aldehyde components. . Therefore, in the present invention, as a result of intensive studies on improving the above-mentioned problems based on this hypothesis, the object of the present invention can be achieved by reacting with titanium using a polyhydric alcohol tripentaerythritol as a ligand. I got the knowledge. The present invention was specific even when polypentaerythritol was used even in the case of polyhydric alcohol, and it was found that the catalyst obtained by reacting tripentaerythritol and a titanium compound has a remarkable color tone improving effect. Specifically, instead of tripentaerythritol, there is no improvement in the color tone or improvement in thermal stability of polymers obtained with dihydric, trihydric or tetrahydric alcohols such as ethylene glycol, glycerin, trimethylolpropane, or pentaerythritol. They found that tripentaerythritol has a remarkable effect. Furthermore, this catalyst is not only excellent in the storage stability of the catalyst, but also can be reduced in the amount of the catalyst because it is difficult to deactivate even in the polymerization system, so that foreign matters resulting from the catalyst can be reduced. Since these ligands coordinate so that titanium is included in these phenomena, the compatibility of the titanium compound in PET increases, and the titanium compound reacts with the water generated in a trace amount in the polymerization system. However, it is considered that the cause is that titanium oxide is suppressed from being by-produced.

As a titanium catalyst containing a polyhydric alcohol as a polymerization catalyst, there is a reaction product of a titanium compound, an alcohol having at least two hydroxyl groups, a phosphorus compound, and a base (Patent Document 5). The alcohol possessed mainly represents a dihydric alcohol, and there is no disclosure of a polyhydric alcohol containing 5 or more hydroxyl groups. Further, a titanium-containing solution containing a titanium compound, an aliphatic diol, and a trihydric or higher polyhydric alcohol is disclosed (Patent Document 6). The trihydric or higher polyhydric alcohol referred to here increases the solubility of the catalyst, Used as a solubilizer to improve the stability of the catalyst solution so as not to cause precipitation, to obtain a high-concentration titanium-containing solution, and to not adversely affect the quality of the recovered and reused aliphatic diol. In addition, the invention is essentially different from the present invention, and there is no disclosure regarding the color tone improvement effect and heat resistance improvement of the resulting polymer, and there is no specific disclosure regarding tripentaerythritol. In addition, a catalyst for producing a polyester (Patent Document 7), in which the main component is titanium oxide and contains a polyhydric alcohol, is disclosed, but in general, titanium oxide is poor in reactivity and does not react with a ligand and has a polymerization activity. Therefore, it is different from the invention of this patent. There is no specific disclosure about tripentaerythritol.
Japanese translation of PCT publication No. 2002-512267 WO2001-000706 JP 2002-293909 A WO2003-008479 JP 2001-524536 A WO 2004-111105 gazette JP 2001-200045 A

  The object of the present invention is to solve the above-mentioned conventional problems, that is, the generation of foreign matters due to the catalyst and the mold contamination during molding are reduced, and the thermal stability and color tone of the polymer are remarkably superior to conventional products. Another object of the present invention is to provide a polycondensation catalyst from which a polyester can be obtained and a method for producing a polyester using the same.

  An object of the present invention is to provide a polyester polycondensation catalyst obtained by reacting a titanium compound and tripentaerythritol at a molar ratio of titanium atom to tripentaerythritol of 1: 1 to 1: 2, and a polyester using the catalyst. This can be achieved by the manufacturing method.

  The titanium-based polycondensation catalyst of the present invention is not only excellent in storage stability of the catalyst but also hardly deactivated in the polymerization system, so that the amount of catalyst can be reduced, which is economically advantageous. In addition, the generation of foreign matters due to the catalyst can be suppressed. In addition, the polyester obtained by polycondensation in the presence of the catalyst dramatically improves the thermal stability and color tone of the polymer as compared with conventional products, and is also suitable for molded articles for fibers, films, bottles, etc. In production, problems such as color tone deterioration, base stain, increased filtration pressure, and thread breakage can be solved.

  The polyester of the present invention is a polymer synthesized from a dicarboxylic acid or an ester-forming derivative thereof and an alkylene glycol or an ester-forming derivative thereof, and particularly if it can be used as a molded article such as a fiber, a film, or a bottle. There is no limitation.

  Specific examples of such polyester include polyethylene terephthalate, polytrimethylene terephthalate, polytetramethylene terephthalate, polycyclohexylene dimethylene terephthalate, polyethylene-2,6-naphthalenedicarboxylate, polyethylene-1,2- And bis (2-chlorophenoxy) ethane-4,4′-dicarboxylate. The present invention is suitable for polyethylene terephthalate or polyester copolymers mainly containing ethylene terephthalate units, which are most commonly used.

  In addition, these polyesters have copolymer components such as diphthalic acid such as isophthalic acid, naphthalenedicarboxylic acid, 4,4′-diphenyldicarboxylic acid, cyclohexanedicarboxylic acid, and ester-forming derivatives thereof, polyethylene glycol, hexamethylene glycol, neo Diol compounds such as pentyl glycol, polypropylene glycol, cyclohexane dimethanol, and ester-forming derivatives thereof may be copolymerized.

In general, a series of reactions for synthesizing a polyester from a dicarboxylic acid or an ester-forming derivative thereof and an alkylene glycol or an ester-forming derivative thereof includes the following reactions (1) to (3).
(1) Esterification reaction which is reaction of dicarboxylic acid component and alkylene glycol component (2) Transesterification reaction which is reaction of ester-forming derivative component of dicarboxylic acid and alkylene glycol component (3) Substantially esterification reaction Alternatively, the polycondensation reaction in which the transesterification reaction is completed and the obtained polyethylene terephthalate low polymer is increased in the degree of polymerization by dealkylene glycol reaction is the polycondensation catalyst of the present invention among the above (1) to (3) (3) It has the effect which contributes to reaction promotion. Therefore, titanium oxide particles generally used as inorganic particles in fiber matting agents and the like have substantially no catalytic effect on the above reaction and should be used as the polycondensation catalyst of the present invention. It is different from the titanium compound that can be used.

  In the polyester polycondensation catalyst of the present invention, it is essential to react a titanium compound and tripentaerythritol at a molar ratio of titanium atom to tripentaerythritol of 1: 1 to 1: 2. In addition, the titanium oxide particle added to the titanium atom at this time for the purpose of matting is not included.

  The titanium compound of the present invention is an ortho ester or condensed ortho ester of titanium, and specific examples include titanium tetrabutoxide, titanium tetraisopropoxide, titanium tetraethoxide, titanium tetramethoxide, Of these, titanium tetrabutoxide or titanium tetraisopropoxide, which has good reactivity but is relatively stable and easy to handle, is preferable.

  When the titanium compound and tripentaerythritol are reacted, the reaction in the presence of a base is preferable because the stability of the resulting catalyst to water is enhanced.

  The base used in the present invention is an amine compound or an alkali metal compound. Specifically, lithium hydroxide, sodium hydroxide, potassium hydroxide, ammonium hydroxide, tetrabutylammonium hydroxide, lithium carbonate, sodium carbonate, carbonate Examples include potassium, lithium acetate, sodium acetate, potassium acetate, ammonia, N-methylimidazole, and triethylamine. Among them, lithium hydroxide, sodium hydroxide, tetrabutylammonium hydroxide, potassium carbonate, lithium acetate, sodium acetate, ammonia Or N-methylimidazole is preferred because the color tone of the resulting polymer is good.

  When the amount of the base to be reacted is excessively used, not only the color tone of the polymer obtained is deteriorated but also the polycondensation activity is deactivated. The ratio of the number of moles of base to the number of moles of titanium atoms in the titanium compound is preferably 1: 1 to 0.01: 1, more preferably 0.2: 1 to 0.01: 1 in terms of polycondensation activity. . In addition, the titanium oxide particle added to the titanium atom at this time for the purpose of matting is not included.

  When the titanium compound and tripentaerythritol are reacted, it is preferably reacted in a solvent, and the solvent used in that case is preferably a solvent in which the titanium compound and tripentaerythritol are dissolved, particularly water, ethylene glycol or the like. The mixture of is more preferable.

  The reaction time for reacting the titanium compound with tripentaerythritol is preferably 0.1 to 24 hours, and more preferably 0.5 to 1 hour.

  As a method for preparing the catalyst of the present invention, it is preferable to first dissolve tripentaerythritol in water or ethylene glycol or a mixture thereof and add a titanium compound thereto. In this case, the titanium compound is preferably added as a stock solution or an ethylene glycol solution. When adding the titanium compound as an ethylene glycol solution, it is more preferable to add a base to the ethylene glycol solution of the titanium compound and then add it to tripentaerythritol because the stability of the resulting catalyst with respect to water increases. Or it is preferable to add as an ethylene glycol solution.

  When polyester is produced by polycondensation in the presence of the titanium-based polycondensation catalyst thus obtained, the color tone and heat resistance of the resulting polymer are greatly improved.

  The method for producing the polyester of the present invention is such that when a titanium compound excluding titanium oxide particles added for the purpose of matting is added so as to be 1 to 20 ppm in terms of titanium atom with respect to the obtained polymer, the thermal stability of the polymer is increased. The color tone is preferably improved, and more preferably 2 to 10 ppm. Further, as described above, it is preferable that the ratio of the number of moles of titanium atoms to the number of moles of tripentaerythritol is 1: 1 to 1: 2, and as a result, tripentaerythritol has a ratio of 1 to 1 with respect to the obtained polymer. It is preferable to add so that it may become 200 ppm, and it is more preferable to add so that it may become 30-160 ppm.

  Moreover, the manufacturing method of the polyester of this invention may add a phosphorus compound with a titanium compound so that it may become 1-50 ppm in conversion of a phosphorus atom with respect to polyester. In that case, the amount of phosphorus added may be 10 to 20 ppm from the viewpoint of thermal stability and color tone of the polyester during yarn production and film formation. Further, when the phosphorus atom in the phosphorus compound is P / Ti = 0 to 7.00 in terms of molar ratio with respect to the titanium atom of the titanium compound, the thermal stability and color tone of the polyester will be good. When P / Ti = 1.50 to 3.50, the thermal stability and color tone are good and the polymerization time is short.

  The phosphorus compound may be a phosphite compound, a phosphonite compound, a phosphinite compound, or a phosphine compound that is a trivalent phosphorus compound, a phosphate compound that is a pentavalent phosphorus compound, a phosphonate compound, a phosphinate compound, or a phosphine oxide. System compounds may be used. Specifically, as the trivalent phosphorus compound, trimethyl phosphite, triethyl phosphite, triphenyl phosphite, 3,9-bis (2,6-di-t-butyl- represented by the formula (1) 4-methylphenyl) -2,4,8,10-tetraoxa-3,9-diphosphaspiro [5,5] undecane (PEP-36: manufactured by Asahi Denka), diethylphenylphosphonite, dioctylphenylphosphonite, 2) tetrakis (2,4-di-t-butylphenyl) [1,1-biphenyl] -4,4′-diylbisphosphonite (IRGAFOS P-EPQ: manufactured by Ciba Specialty Chemicals) Sandostab P-EPQ (manufactured by Clariant Japan), tetrakis (2,4-di-t-butyl-5) represented by formula (3) -Methylphenyl) [1,1-biphenyl] -4,4'-diylbisphosphonite (GSY-P101: manufactured by Osaki Kogyo Co., Ltd.).

  Examples of pentavalent phosphorus compounds include phosphoric acid, tributyl phosphate, triphenyl phosphate, diethylphenylphosphonate, dibutylphenylphosphonate, dioctylphenylphosphonate, ethyl diethylphosphonoacetate, tetraethyl [1,1 represented by the formula (4) -Biphenyl] -4,4'-diylbisphosphonate, triphenylphosphine oxide and the like.

  In the polyester production method of the present invention, a magnesium compound may be used as a co-catalyst, and a cobalt compound may be used in combination with the co-catalyst for the purpose of color tone adjustment. Specific examples of the magnesium compound used in this case include magnesium oxide, magnesium hydroxide, magnesium alkoxide, magnesium acetate, and magnesium carbonate. Specific examples of the cobalt compound include cobalt chloride, cobalt nitrate, cobalt carbonate, cobalt acetylacetonate, cobalt naphthenate, and cobalt acetate tetrahydrate.

  Further, in the method for producing a polyester of the present invention, a blue adjusting agent and / or a red adjusting agent may be added as a color adjusting agent instead of cobalt.

  The color tone adjusting agent of the present invention is a dye and / or pigment used for resin (original liquid coloring), and is an oil-soluble dye (SOLVENT DYES), a vat dye (VAT DYES), a disperse dye (DESPERSE DYES). ) And organic pigments (ORGANIC PIGMENT). Specifically, COLOR INDEX GENERIC NAME includes SOLVENT BLUE 104, SOLVENT BLUE 122, SOLVENT BLUE 45, and the like as blue-based adjusting agents, and SOLVENT RED 111, SOLVENT RED 179, SOLVENT RED 179, SOLVENT RED 179, SOLVENT RED 179, RED 195, SOLVENT RED 135, PIGMENT RED 263, VAT RED 41 and the like, and purple-based adjusting agents include DESPERSE VIOLET 26, SOLVENT VIOLET 13, SOLVENT VIOLET 36, SOLVENT VIOLET 49, etc. Among them, SOLVENT BLUE 104, SOLVENT BLUE 45, SOLVENT RED 179, SOLVENT RED 195, SOLVENT RED 135, which do not contain halogen that is likely to cause corrosion of equipment, have relatively good heat resistance at high temperatures and excellent color developability, SOLVENT VIOLET 36 is preferably used.

  Moreover, you may use these color tone regulators 1 type or multiple types according to the objective. In particular, it is preferable to use one or more blue-type adjusting agents and red-type adjusting agents, since the color tone can be finely controlled. Furthermore, in this case, the color tone of the resulting polyester is particularly good when the ratio of the blue-based adjusting agent is 50% by weight or more with respect to the total amount of the added color adjusting agent.

  Finally, the content of the color tone adjusting agent with respect to the polyester is preferably 0 to 10 ppm in total. If it exceeds 30 ppm, the transparency of the polyester may be lowered or the color may become dull.

  In the polyester production method of the present invention, the polycondensation catalyst and additives may be added as they are to the polyester reaction system, but the compound is previously mixed with a solvent containing an alkylene glycol component that forms a polyester such as ethylene glycol. Then, when a low-boiling component such as water used at the time of synthesizing the compound is removed, if necessary, and then added to the reaction system, the generation of foreign matter in the polymer is further suppressed. The addition is preferably performed after the esterification reaction or transesterification reaction and before the polycondensation reaction is started.

  The order of addition of the polycondensation catalyst, phosphorus compound, magnesium compound, cobalt compound and color tone modifier of the present invention to the reaction system is not particularly limited, but the polycondensation catalyst of the present invention and other additives, that is, phosphorus compounds The magnesium compound, cobalt compound and color additive are preferably added separately to the reaction system.

The polyester obtained by the method for producing a polyester of the present invention preferably has an intrinsic viscosity (IV) of 0.4 to 1.0 dlg ⁻¹ when measured at 25 ° C. using orthochlorophenol as a solvent. More preferably from 0.5~0.8dlg ^-1, particularly preferably from 0.6~0.7dlg ^-1.

  Moreover, in order to improve the thermal stability which is the object of the present invention, the terminal carboxyl group concentration of the polyester is preferably in the range of 1 to 40 equivalents / ton. As the terminal carboxyl group concentration is lower, the thermal stability is improved, and the dirt adhering to the mold during molding and the dirt adhering to the die during yarn production are significantly reduced. When the terminal carboxyl group concentration exceeds 40 equivalents / ton, the effect of reducing dirt adhering to the mold or die may be reduced. The terminal carboxyl group concentration is preferably 35 equivalents / ton or less.

  The polyester obtained by the method for producing a polyester of the present invention preferably has a diethylene glycol content of 0.1 to 1.5% by weight or less because mold contamination during molding is small. More preferably, it is 1.3% by weight or less.

  Moreover, since the polyester obtained by the manufacturing method of the polyester of this invention is 1-15 ppm or less in content of acetaldehyde, since the bad influence to the flavor in a molded object and a fragrance is suppressed, it is preferable. More preferably, it is 13 ppm or less, Most preferably, it is 11 ppm or less.

  The color tone of the chip shape is a hunter value, the L value is in the range of 60 to 80, the a value is in the range of -7 to 2, and the b value is in the range of -5 to 5. To preferred.

  The polyester obtained by the method for producing a polyester of the present invention was dried under reduced pressure at 150 ° C. for 12 hours, and after being melted at 290 ° C. for 60 minutes in a nitrogen atmosphere, the change in color tone b value Δb value 290 was −5 to 5 It is preferable from the point of the heat resistance of a polymer that it is the range of these. 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. Preferably it is 3 or less.

  The polyester obtained by the method for producing a polyester of the present invention is useful as a fiber by forming into a filament shape by, for example, melt extrusion molding or the like and then stretching.

  A method for producing the polyester of the present invention will be described. 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.
(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.
(B) A process in which dimethyl terephthalate and ethylene glycol are used as raw materials, a low polymer is obtained by a transesterification reaction, and a high molecular weight polymer is obtained by a subsequent polycondensation reaction.

  Although the esterification reaction proceeds even without a catalyst, the ester exchange reaction proceeds using a compound such as magnesium, calcium, or lithium as a catalyst, and after the ester exchange reaction is substantially completed, In order to inactivate the catalyst used in the step, a phosphorus compound is added.

  The polyester of the present invention is obtained by adding the polycondensation catalyst of the present invention to the low polymer obtained in the first half of the series of reactions (A) or (B), and optionally a phosphorus compound, magnesium compound, cobalt compound, color tone. After adding a regulator and titanium oxide particles, a polycondensation reaction is performed to obtain a high molecular weight polyethylene terephthalate.

  Further, 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.
(1) Intrinsic viscosity of polymer IV
Measurement was performed at 25 ° C. using orthochlorophenol as a solvent.
(2) Carboxyl terminal group amount of polymer The measurement was carried out by titrating with an automatic titrator (Hiranuma Sangyo Co., Ltd., COM-550) using orthocresol as a solvent and a 0.02 N aqueous NaOH solution at 25 ° C.
(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).
(4) Diethylene glycol content of the polymer 1,6-hexanediol / methanol mixed solution was added and cooled using monoethanolamine as a solvent, neutralized and centrifuged, and then the supernatant was gas chromatographed (manufactured by Shimadzu Corporation) GC-14A).
(5) Polymer acetaldehyde content Polyester and pure water were subjected to heat extraction under a nitrogen seal at 160 ° C for 2 hours, and the amount of acetaldehyde in the extract was gas chromatographed using isobutyl alcohol as an internal standard ("Shimadzu Corporation" GC-14A ").
(6) 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.
(7) Observation of deposits in the die The amount of deposits around the die holes 72 hours after spinning of the fibers was observed using a long focus microscope. A state in which almost no deposit was observed was judged as ◯ (passed), and a state in which deposits were found and yarn breakage frequently occurred was judged as x (disqualified).

Example 1
A 3 L three-necked flask was purged with nitrogen, and then 1000 mL of dehydrated ethylene glycol and 5.8 g (15.7 mmol) of tripentaerythritol were added as reaction solvents, and heated to an internal temperature of 80 ° C. in an oil bath. And stirred. After 1 hour, the oil bath was removed, and the internal temperature was cooled to 25 ° C. Then, 2.69 g (15.7 mmol) of titanium tetramethoxide was added as a titanium compound, and then the mixture was stirred at 25 ° C for 1 hour. A colorless and transparent catalyst solution TT-1 (titanium content: 0.75 g / L) was thus obtained.

Examples 2-6
Catalyst solutions TT-2 to 4 and 6 (titanium), except that the titanium compound, the molar ratio of tripentaerythritol / Ti, the reaction temperature, the reaction time, and the reaction solvent were changed as described in Table 1. Content: 0.75 g / L) was obtained. Since only white precipitate was formed in Example 5, after freeze-drying once to remove moisture, the recovered white solid was dispersed in ethylene glycol, and catalyst suspension TT-5 (titanium content: 0 .75 g / L).

Example 7
A 2 L three-necked flask was purged with nitrogen, and 500 mL of distilled water and 5.8 g (15.7 mmol) of tripentaerythritol were added thereto as a reaction solvent, and heated to an internal temperature of 80 ° C. in an oil bath. Stir. After 1 hour, the oil bath was removed and the internal temperature was cooled to 25 ° C. On the other hand, another 2 L three-necked flask was replaced with nitrogen, and 500 mL of dehydrated ethylene glycol was added thereto as a reaction solvent, and 4.46 g (15.7 mmol) of titanium tetraisopropoxide was added thereto as a titanium compound. Subsequently, 1.57 mL (1.57 mmol) of 1 mol / L sodium hydroxide aqueous solution was added as a base, and the mixture was stirred at room temperature for 10 minutes. The ethylene glycol solution of the titanium compound was added to the previously prepared aqueous tripentaerythritol solution and stirred at a reaction temperature of 25 ° C. for 1 hour. A colorless and transparent catalyst solution TT-7 (titanium content: 0.75 g / L) was thus obtained.

Examples 8-14
Catalyst TT-8-14 (titanium content: 0.75 g) in the same manner as in Example 7 except that the titanium compound, base, base / Ti molar ratio, reaction temperature and reaction time were changed as described in Table 1. / L). However, in Example 13, when N-methylimidazole was added as a base, an ethylene glycol solution was used instead of an aqueous solution.

Comparative Example 1
A 3 L three-necked flask was replaced with nitrogen, 1000 mL of dehydrated ethylene glycol was added thereto as a reaction solvent, and the reaction temperature was adjusted to 25 ° C. with a thermostatic bath. Thereto, 4.46 g (15.7 mmol) of titanium tetraisopropoxide was added as a titanium compound, and then the reaction time was 1 hour, followed by stirring at a reaction temperature of 25 ° C. Thus, a colorless and transparent catalyst solution C-1 (titanium content: 0.75 g / L) was obtained.

Comparative Example 2
A 2 L three-necked flask was purged with nitrogen, and 500 mL of distilled water was added thereto as a reaction solvent. On the other hand, another 2 L three-necked flask was replaced with nitrogen, and 500 mL of dehydrated ethylene glycol was added thereto as a reaction solvent, and 4.46 g (15.7 mmol) of titanium tetraisopropoxide was added thereto as a titanium compound. Subsequently, 31.4 mL (31.4 mmol) of 1 mol / L sodium hydroxide aqueous solution was added as a base, and the mixture was stirred for 10 minutes at room temperature. This ethylene glycol solution of the titanium compound was added to 500 mL of the above distilled water and stirred at a reaction temperature of 25 ° C. for 1 hour. As a result, a cloudy catalyst suspension C-2 (titanium content: 0.75 g / L) was obtained.

Comparative Example 3
A colorless and transparent catalyst solution C-3 (titanium content: 0.75 g / L) was prepared in the same manner as in Example 1 except that the molar ratio of the titanium compound and tripentaerythritol / Ti was changed as shown in Table 1. Obtained.

Comparative Examples 4 and 5
Except that the molar ratio of tripentaerythritol / Ti and the molar ratio of base and base / Ti were changed as described in Table 1, catalyst solution C-4,5 (titanium content: 0. 75 g / L) was obtained. However, in Comparative Example 5, when N-methylimidazole was added as a base, an ethylene glycol solution was used instead of an aqueous solution.

Comparative Examples 6, 7, 9-11
As shown in Table 1, titanium tetraisopropoxide is used as the titanium compound, and other polyhydric alcohols listed in Table 1 are used instead of tripentaerythritol, and the molar ratio of polyhydric alcohol / Ti is set forth in Table 1. A colorless and transparent catalyst solution C-6, 7, 9 to 11 (titanium content: 0.75 g / L) was obtained in the same manner as in Example 1 except that it was as described above.

Comparative Example 8
Catalyst C-8 (titanium content: 0.75 g / L) was obtained in the same manner as in Example 7 except that dipentaerythritol was used in place of tripentaerythritol and the base was changed as described in Table 1. .

Example 15
About 100 kg of bis (hydroxyethyl) terephthalate is charged in advance, and 82.5 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.) 35.4 kg of slurry was sequentially supplied over 4 hours, and after completion of the supply, an esterification reaction was carried out over an additional hour, and 101.5 kg of the resulting esterification reaction product was polycondensed. Transferred to.

  In the esterification reaction product, an ethylene glycol solution of magnesium acetate equivalent to 5 ppm in terms of magnesium atom relative to the obtained polymer, an ethylene glycol solution of cobalt acetate equivalent to 20 ppm in terms of cobalt atom relative to the resulting polymer, and the resulting polymer Tetrakis (2,4-di-t-butyl-5-methylphenyl) [1,1-biphenyl] -4,4′-diylbisphosphonite equivalent to 10 ppm in terms of phosphorus atom (Osaki Kogyo Co., Ltd., 30 minutes before adding GSY-P101), the mixture was premixed in another mixing tank, stirred at room temperature for 30 minutes, and then the mixture was added. After 5 minutes, a catalyst solution TT-1 equivalent to 5 ppm in terms of titanium atoms is added to the resulting polymer, and further 5 minutes later, an ethylene glycol slurry of titanium oxide particles is converted to titanium oxide particles in terms of the obtained polymer. 0.3% by weight was added. After another 5 minutes, the reaction system was decompressed to start 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. 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 into a strand, 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 39 minutes. The obtained polymer was excellent in color tone and heat resistance.

  The polyester was vacuum-dried at 150 ° C. for 12 hours, then subjected to a spinning machine, melted by a melter, discharged from the spinning pack portion, and taken up at a speed of 1000 m / min. In the melt spinning process, almost no deposits around the nozzle holes and no increase in filtration pressure were observed during spinning.

Examples 16-28
A polyester was polymerized and melt-spun in the same manner as in Example 15 except that the catalyst was changed as shown in Table 2. The obtained polymer was excellent in both color tone and heat resistance. In addition, almost no deposits and increase in filtration pressure around the nozzle holes during spinning were observed.

Examples 29-37
Polyester was polymerized and melt-spun in the same manner as in Example 15 except that the amount of catalyst and catalyst added, the type and amount of phosphorus compound were changed as shown in Table 4. In Examples 29, 33, and 34, the color tone was slightly inferior, and in Examples 29, 34, and 35, the heat resistance was slightly inferior, but the level was satisfactory for the product. In other examples, both the color tone and heat resistance were good. In addition, almost no deposits and increase in filtration pressure around the nozzle holes during spinning were observed.

Examples 38-42
In addition to changing the addition amount of cobalt as shown in Table 4, when adding magnesium, cobalt, and phosphorus to the esterification reaction product, dyes were subsequently added as color adjusting agents as shown in Table 4. Otherwise, the polyester was polymerized and melt-spun as in Example 15. In all cases, the color tone had a low L value, and in Examples 40 to 42, the color tone a value and b value were low, but they were at a level that is not problematic in terms of product. In all cases, the heat resistance was good. In addition, almost no deposits and increase in filtration pressure around the nozzle holes during spinning were observed.

Comparative Examples 12-22
A polyester was polymerized and melt-spun in the same manner as in Example 15 except that the catalyst was changed as shown in Table 6. In Comparative Example 13, the predetermined stirring torque was not reached. In Comparative Examples 15 and 16, the time required to reach a predetermined stirring torque was significantly increased. In any case, the color tone of the polymer was strongly yellowish (color tone b value was high), contained a large amount of acetaldehyde, the Δb value was large, and the polymer was inferior in heat resistance.

Comparative Examples 23 and 27-29
As described in Table 6, the polycondensation catalyst was changed, the addition amount of magnesium acetate was changed, and a color tone adjusting agent (SOLVENT BLUE 104) was added instead of adding cobalt acetate. Polyester was polymerized and melt spun. The color tone b value of the polymer was good, but the L value was low, it contained a lot of acetaldehyde, the Δb value 290 was large, and the polymer was inferior in heat resistance.

Comparative Example 24
Polyester was polymerized and melt-spun in the same manner as in Example 15 except that C-1 was used as the polycondensation catalyst and tripentaerythritol was added to the polymerization system separately from the catalyst so that the molar ratio of tripentaerythritol / Ti was 1. did. The polymer color tone was strongly yellowish (color tone b value was high), contained a large amount of acetaldehyde, had a large Δb value of 290, and was inferior in heat resistance.

Comparative Examples 25 and 26
The polyester was polymerized in the same manner as in Example 15 except that the polycondensation catalyst and the phosphorus compound were changed as shown in Table 6. In each case, the polyester did not reach the predetermined stirring torque.

Comparative Example 30
Polyester was polymerized and melt-spun in the same manner as in Example 15 except that antimony oxide, an antimony compound, was added as a polycondensation catalyst instead of the titanium compound, and the addition amount of the phosphorus compound was increased. Although the polymer color tone and heat resistance were good, deposits were seen around the mouthpiece holes during melt spinning, resulting in increased filtration pressure and yarn breakage.

Claims (14)

A polyester polycondensation catalyst obtained by reacting a titanium compound and tripentaerythritol at a molar ratio of titanium atom to tripentaerythritol of 1: 1 to 1: 2. The polyester polycondensation catalyst according to claim 1, wherein the titanium compound and tripentaerythritol are reacted in the presence of a base. The polyester polycondensation catalyst according to claim 1 or 2, wherein the titanium compound is at least one selected from titanium tetrabutoxide, titanium tetraisopropoxide, titanium tetraethoxide, or titanium tetramethoxide. 3. The base according to claim 2, wherein the base is at least one selected from lithium hydroxide, sodium hydroxide, tetrabutylammonium hydroxide, potassium carbonate, lithium acetate, sodium acetate, ammonia, or N-methylimidazole. The polyester polycondensation catalyst according to 3. The polyester polycondensation catalyst according to any one of claims 2 to 4, wherein the molar ratio of the base to the titanium atom of the titanium compound is 1: 1 to 0.01: 1. The polyester polycondensation catalyst according to any one of claims 1 to 5, wherein the reaction between the titanium compound and tripentaerythritol is carried out in water and / or ethylene glycol. The polyester polycondensation catalyst according to any one of claims 1 to 6, wherein a titanium compound is added to a water and / or ethylene glycol solution of tripentaerythritol. The polyester polycondensation catalyst according to any one of claims 1 to 6, wherein a mixed solution of an ethylene glycol solution of a titanium compound and a base is added to water and / or ethylene glycol solution of tripentaerythritol. When producing a polyester by polycondensing a polymerization starting material comprising an esterified product of an aromatic dicarboxylic acid and an alkylene glycol and / or a low polymer thereof, a polycondensation catalyst according to any one of claims 1 to 8. A method for producing a polyester comprising using the polyester polycondensation catalyst described above. The method for producing a polyester according to claim 9, wherein the aromatic dicarboxylic acid is a main component of terephthalic acid. The method for producing a polyester according to claim 9 or 10, wherein the alkylene glycol is a main component of ethylene glycol. The method for producing a polyester according to any one of claims 9 to 11, wherein the titanium compound is added so that the amount of titanium element in the obtained polyester is 1 to 20 ppm. Content of tripentaerythritol with respect to polyester is 1-200 ppm, The polyester composition obtained with the manufacturing method of polyester of any one of Claims 9-12 characterized by the above-mentioned. A polyester fiber obtained by melt-molding the polyester composition of claim 13.