JP2007169552A - Polymerization catalyst for aromatic polyester and method for producing aromatic polyester using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymerization catalyst giving an aromatic polyester slight in foreign matter and having favorable color tone, and to provide a method for producing the aromatic polyester using the catalyst. <P>SOLUTION: The polymerization catalyst for aromatic polyester is a nitrogen-containing organic compound with a structure of the formula 1 (wherein, X<SP>1</SP>and X<SP>2</SP>are each H or a 1-30C hydrocarbon group; Y<SP>1</SP>is a 1-30C hydrocarbon group having one or more any groups selected from ether group, ester group, hydroxy group, alkoxy group and carboxy group; and R<SP>1</SP>is a 2-30C hydrocarbon group). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an aromatic polyester polymerization catalyst capable of obtaining an aromatic polyester having less foreign matter and good color tone, and an aromatic polyester production method.

  Aromatic polyesters are used for various purposes because of their useful functionality. For example, they are used for clothing, materials, and medical use. 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. However, 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, when a polymer obtained using an antimony catalyst is melt-spun into a fiber, it is known that an antimony catalyst residue is deposited around the die hole. As this deposition progresses, it becomes a cause of defects in the filament, so that it needs to be removed in a timely manner. The deposition of the antimony catalyst residue is considered to be due to the antimony compound in the polymer being transformed in the vicinity of the die and partially vaporizing and dissipating, and then a component mainly composed of antimony remains in the die.

  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 undesirable characteristics and contributes to a decrease in operability.

  In view of the above background, there is a demand for aromatic polyesters that contain little or no antimony. Thus, germanium compounds are known when the role of a polycondensation catalyst is required for compounds other than antimony compounds, but germanium compounds are very expensive and difficult to use for general purposes.

  On the other hand, as a polymerization catalyst, a proposal has been made to use a titanium complex composed of a titanium compound and a phosphorus compound, or a titanium compound and a compound containing a nitrogen atom (hereinafter abbreviated as “nitrogen-containing”) as an aromatic polyester polymerization catalyst ( Patent Literatures 1 to 3). According to these methods, although the foreign matter resulting from the catalyst can be reduced, it is not sufficient, and the color tone of the obtained polymer is not sufficient.

  Further, a proposal has been made to use a compound comprising an alkaline earth metal compound and a nitrogen-containing compound as a polymerization catalyst as an aromatic polyester polymerization catalyst (see Patent Document 4). Although this method can improve the color of the polymer and the amount of foreign matter due to the catalyst, it is still not sufficient.

  In addition, proposals have been made to use a nitrogen-containing organic compound alone containing no metal as a catalyst, and according to this method, it is possible to improve the color of the polymer and the amount of foreign matter due to the catalyst. However, the activity of the catalyst is low, which is not sufficient from the viewpoint of productivity (see Patent Documents 5 and 6).

Therefore, in the present invention, as a result of improving the above-mentioned problems and intensively studying an aromatic polyester with less thread breakage, the object of the present invention can be achieved by using a nitrogen-containing organic compound having a specific structure as a polymerization catalyst. I got the knowledge.
JP 2001-524536 A (Claims) JP 2001-316463 A (Claims) JP 2004-250588 A (Claims) JP 2000-191764 A (Claims) Japanese Patent Laid-Open No. 03-64320 (Claims) JP 2003-292598 A (Claims)

  The object of the present invention is to solve the above-mentioned conventional problems while maintaining productivity equivalent to that of a metal-containing catalyst, and has good yarn-making properties and film-forming properties, and has fewer foreign matters than conventional products, and has a fragrance. It is an object of the present invention to provide an aromatic polyester polymerization catalyst capable of obtaining an aromatic polyester excellent in color of an aromatic polyester and a method for producing an aromatic polyester using the same.

  An aromatic polyester is produced using a catalyst characterized by being a nitrogen-containing organic compound having a structure represented by Formula 1.

(In Formula 1, X ¹ and X ² each independently represent hydrogen or a hydrocarbon group having 1 to 30 carbon atoms. Y ¹ is an ether group, an ester group, a hydroxy group, an alkoxy group, or a carboxyl group. And represents a hydrocarbon group having 1 to 30 carbon atoms containing one or more of these, R ¹ represents a hydrocarbon group having 2 to 30 carbon atoms.)

  According to the aromatic polyester polymerization catalyst of the present invention and the method for producing an aromatic polyester using the same, it is possible to obtain an aromatic polyester having a good color tone with few foreign matters while maintaining productivity.

  The aromatic polyester of the present invention is a polymer synthesized from a dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof. What can be used as molded articles, such as a fiber, a film, and a bottle, is preferable.

  Specific examples of such aromatic polyesters 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 aromatic polyester copolymers mainly containing ethylene terephthalate units, which are most commonly used.

  In addition to diethylene glycol, these aromatic polyesters include dicarboxylic acids such as adipic acid, isophthalic acid, sebacic acid, phthalic acid, naphthalenedicarboxylic acid, 4,4′-diphenyldicarboxylic acid, cyclohexanedicarboxylic acid and the like as copolymerization components. Its ester-forming derivatives, dioxy compounds such as polyethylene glycol, hexamethylene glycol, neopentyl glycol, polypropylene glycol, cyclohexanedimethanol, oxycarboxylic acids such as p- (β-oxyethoxy) benzoic acid, and ester-forming derivatives thereof May be copolymerized within 5 mol% with respect to the total acid component.

  The aromatic polyester polymerization catalyst of the present invention must be a nitrogen-containing organic compound having a structure represented by Formula 1.

(In Formula 1, X ¹ and X ² each independently represent hydrogen or a hydrocarbon group having 1 to 30 carbon atoms. Y ¹ is an ether group, an ester group, a hydroxy group, an alkoxy group, or a carboxyl group. And represents a hydrocarbon group having 1 to 30 carbon atoms which may contain one or more of these, R ¹ represents a hydrocarbon group having 2 to 30 carbon atoms.)
Examples of the nitrogen-containing organic compound include 1,3-bis (2,4,6-trimethylphenyl) in which R ¹ is ethylene, Y ¹ is methoxymethylene, and X ¹ and X ² are 2,4,6-trimethylphenyl, respectively. ) -2-methoxyimidazolidine, R ¹ is 1,2-dimethylethylene, Y ¹ is methoxymethylene, and X ¹ and X ² are 2,4,6-trimethylphenyl, respectively. , 6-Trimethylphenyl) -2-methoxy-4,5-dimethylimidazolidine, R ¹ is ethylene, Y ¹ is methoxymethylene, and X ¹ and X ² are each methyl. 1,3-bis (2,4,6-) in which lysine, R ¹ is ethylene, Y ¹ is (2-furyl) methylene, and X ¹ and X ² are 2,4,6-trimethylphenyl, respectively. 1,3-dimethyl-2- (2-furyl) imidazolidine in which trimethylphenyl) -2-methoxyimidazolidine, R ¹ is ethylene, Y ¹ is methylene (2-furyl), and X ¹ and X ² are each methyl Among them, 1,3-bis (2,4,6-trimethylphenyl) -2-methoxyimidazolidine is preferable from the viewpoints of productivity, polymer thermal stability, and color tone.

  The catalyst of the present invention is a polyethylene terephthalate obtained by substantially completing the ester reaction or transesterification reaction in a polymer synthesized from a dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof. This refers to a compound that substantially contributes to the acceleration of all or some of the polycondensation reactions that increase the degree of polymerization of the low polymer by a dediol reaction.

  Therefore, a metal oxide such as titanium generally used as inorganic particles has substantially no catalytic action for the above reaction, and can be used as a catalyst of the present invention. Different from compound.

  The nitrogen-containing organic compound in the present invention is preferably added in an amount of 100 to 100,000 ppm with respect to the resulting polymer. When it is 100 to 10000 ppm, the thermal stability and color tone of the polymer become better, more preferably 200 to 5000 ppm.

  The nitrogen-containing organic compound used in the present invention may be added as it is to the reaction system of the aromatic polyester, but may be mixed in advance with a solvent containing a diol component that forms an aromatic polyester such as ethylene glycol or propylene glycol. It is preferable from the viewpoint of maintaining the suppression and catalytic activity. The timing of addition may be substantially before the start of the polycondensation reaction, and may be added before the esterification reaction or transesterification reaction, or after the completion of the reaction and before the polycondensation reaction is started. Furthermore, a phosphorus compound may be added separately from the viewpoints of color tone improvement and thermal stability. In this case, in order to suppress the deactivation of the catalyst due to the contact between the nitrogen-containing organic compound and the phosphorus compound, a method of adding to different reaction tanks or the nitrogen-containing organic compound and the phosphorus compound of the present invention in the same reaction tank You may use the method which makes an addition interval 1-15 minutes, and the method which leaves | separates an addition position.

  Moreover, it is preferable that said phosphorus compound added separately is at least 1 sort (s) chosen from a phosphoric acid type compound, a phosphonic acid type compound, a phosphinic acid type compound, and a phosphite type compound. Specifically, for example, phosphoric acid compounds include phosphoric acid, phosphoric acid sodium salt, phosphoric acid potassium salt, trimethyl phosphate, triethyl phosphate, triphenyl phosphate, and the like. Is phosphorous acid, sodium salt of phosphorous acid, potassium salt of phosphorous acid, trimethyl phosphite, triethyl phosphite, triphenyl phosphite, methylphosphonic acid, ethylphosphonic acid, propylphosphonic acid, isopropylphosphonic acid, Butylphosphonic acid, phenylphosphonic acid, benzylphosphonic acid, tolylphosphonic acid, xylylphosphonic acid, biphenylphosphonic acid, naphthylphosphonic acid, anthrylphosphonic acid, 2-carboxyphenylphosphonic acid, 3-carboxyphenylphosphonic acid, 4- Carboxyphenylphosphonic acid, 2,3-dicarboxy Phenylphosphonic acid, 2,4-dicarboxyphenylphosphonic acid, 2,5-dicarboxyphenylphosphonic acid, 2,6-dicarboxyphenylphosphonic acid, 3,4-dicarboxyphenylphosphonic acid, 3,5-dicarboxyphenyl Phosphonic acid, 2,3,4-tricarboxyphenylphosphonic acid, 2,3,5-tricarboxyphenylphosphonic acid, 2,3,6-tricarboxyphenylphosphonic acid, 2,4,5-tricarboxyphenylphosphonic acid 2,4,6-tricarboxyphenylphosphonic acid, methylphosphonic acid dimethyl ester, methylphosphonic acid diethyl ester, ethylphosphonic acid dimethyl ester, ethylphosphonic acid diethyl ester, phenylphosphonic acid dimethyl ester, phenylphosphonic acid diethyl ester, phenyl Suphonic acid diphenyl ester, benzylphosphonic acid dimethyl ester, benzylphosphonic acid diethyl ester, benzylphosphonic acid diphenyl ester, lithium (ethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate), sodium (3,5- Di-tert-butyl-4-hydroxybenzylphosphonate ethyl), magnesium bis (3,5-di-tert-butyl-4-hydroxybenzylphosphonate ethyl), calcium bis (3,5-di-tert-butyl- 4-hydroxybenzylphosphonic acid ethyl), diethylphosphonoacetic acid, methyl diethylphosphonoacetate, ethyl diethylphosphonoacetate and the like. Examples of phosphinic acid compounds include hypophosphorous acid, sodium hypophosphite, hypophosphorous acid. Potassium acid, methylphosphine Phosphoric acid, ethylphosphinic acid, propylphosphinic acid, isopropylphosphinic acid, butylphosphinic acid, phenylphosphinic acid, tolylphosphinic acid, xylylphosphinic acid, biphenylylphosphinic acid, diphenylphosphinic acid, dimethylphosphinic acid, diethylphosphinic acid, Dipropylphosphinic acid, diisopropylphosphinic acid, dibutylphosphinic acid, ditolylphosphinic acid, dixylphosphinic acid, dibiphenylylphosphinic acid, naphthylphosphinic acid, anthrylphosphinic acid, 2-carboxyphenylphosphinic acid, 3-carboxyphenylphosphine Acid, 4-carboxyphenylphosphinic acid, 2,3-dicarboxyphenylphosphinic acid, 2,4-dicarboxyphenylphosphinic acid, 2,5-dicarboxypheny Phosphinic acid, 2,6-dicarboxyphenylphosphinic acid, 3,4-dicarboxyphenylphosphinic acid, 3,5-dicarboxyphenylphosphinic acid, 2,3,4-tricarboxyphenylphosphinic acid, 2,3,5 -Tricarboxyphenylphosphinic acid, 2,3,6-tricarboxyphenylphosphinic acid, 2,4,5-tricarboxyphenylphosphinic acid, 2,4,6-tricarboxyphenylphosphinic acid, bis (2-carboxyphenyl) Phosphinic acid, bis (3-carboxyphenyl) phosphinic acid, bis (4-carboxyphenyl) phosphinic acid, bis (2,3-dicarboxylphenyl) phosphinic acid, bis (2,4-dicarboxyphenyl) phosphinic acid, Bis (2,5-dicarboxyphenyl) phosphinic acid, bi (2,6-dicarboxyphenyl) phosphinic acid, bis (3,4-dicarboxyphenyl) phosphinic acid, bis (3,5-dicarboxyphenyl) phosphinic acid, bis (2,3,4-tricarboxyphenyl) Phosphinic acid, bis (2,3,5-tricarboxyphenyl) phosphinic acid, bis (2,3,6-tricarboxyphenyl) phosphinic acid, bis (2,4,5-tricarboxyphenyl) phosphinic acid, and bis (2,4,6-tricarboxyphenyl) phosphinic acid, methylphosphinic acid methyl ester, dimethylphosphinic acid methyl ester, methylphosphinic acid ethyl ester, dimethylphosphinic acid ethyl ester, ethylphosphinic acid methyl ester, diethylphosphinic acid methyl ester, Ethyl ethyl phosphinate Esters, diethylphosphinic acid ethyl ester, phenylphosphinic acid methyl ester, phenylphosphinic acid ethyl ester, phenylphosphinic acid phenyl ester, diphenylphosphinic acid methyl ester, diphenylphosphinic acid ethyl ester, diphenylphosphinic acid phenyl ester, benzylphosphinic acid methyl ester, Examples thereof include benzylphosphinic acid ethyl ester, benzylphosphinic acid phenyl ester, bisbenzylphosphinic acid methyl ester, bisbenzylphosphinic acid ethyl ester, bisbenzylphosphinic acid phenyl ester, etc., and phosphite compounds include triphenyl phosphite, tris ( 4-monononylphenyl) phosphite, tri (monononyl / dinonyl phenyl) phosphite Tris (2,4-di-tert-butylphenyl) phosphite, monooctyldiphenyl phosphite, monodecyldiphenyl phosphite, bis [2,4-bis (1,1-dimethylethyl) -6-methylphenyl] ethyl Phosphite, tetrakis (2,4-di-tert-butylphenyl) 4,4'-biphenylene diphosphite, dioctyl monophenyl phosphite, didecyl monophenyl phosphite, bis (2,6-di-tert-butyl -4-methylphenyl) pentaerythritol di-phosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol di-phosphite, 3,9-bis (2,4-dicumylphenoxy)- 2,4,8,10-tetraoxa-3,9-diphosphaspiro [5,5] Ndekan, phenyl - neopentyl glycol - phosphite, 2,2-methylenebis (4,6-di -tert- butylphenyl) octyl phosphite, and the like.

  In particular, from the viewpoint of suppressing foreign matter and improving color tone, it is preferably a phosphite compound, and among them, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol-di-phosphite, bis (2, 4-Di-tert-butylphenyl) pentaerythritol di-phosphite is preferred.

  The phosphorus compound is preferably added in an amount of 0.5 to 250 ppm in terms of phosphorus atoms with respect to the resulting polymer. When it is 1 to 200 ppm, the thermal stability and color tone of the polymer become better, and it is more preferably 5 to 150 ppm.

  In the method for producing an aromatic polyester of the present invention, the addition of a cobalt compound or a manganese compound at an arbitrary time is preferable because the color tone of a polymer obtained is good. The cobalt compound used in this case is not particularly limited, and specific examples include cobalt chloride, cobalt nitrate, cobalt carbonate, cobalt acetylacetonate, cobalt naphthenate, and cobalt acetate tetrahydrate. Further, the manganese compound is not particularly limited, and specific examples thereof include manganese chloride, manganese bromide, manganese nitrate, manganese carbonate, manganese acetylacetonate, manganese acetate tetrahydrate, manganese acetate dihydrate, and the like. Can be mentioned.

  Further, for the purpose of assisting the polymerization activity of the catalyst of the present invention, an alkali metal compound, an alkaline earth metal compound, an aluminum compound, a zinc compound, a tin compound, or the like may be added.

  Furthermore, in addition to particles such as titanium dioxide, silicon oxide, calcium carbonate, magnesium oxide, silicon nitride, clay, talc, kaolin, carbon black, it is possible to add anti-coloring agents, stabilizers, antioxidants, etc. .

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

  Polyethylene terephthalate is usually produced by one of the following processes. (1) 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 (2) 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. Also, in the transesterification reaction, the process proceeds using a compound such as manganese, calcium, magnesium, zinc, lithium and the like, and the catalyst used in the reaction is deactivated after the transesterification reaction is substantially completed. And adding a phosphorus compound is any of the processes performed.

  The production method of the present invention comprises a matting agent applied to a low polymer obtained in any stage of the series of reactions (1) or (2), preferably in the first half of the series of reactions (1) or (2). After adding additives such as titanium dioxide particles, cobalt compounds, manganese compounds, etc., the above-mentioned nitrogen-containing organic compound is added as a polycondensation catalyst and 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) Color tone of polymer The obtained polymer is rapidly cooled from a molten state, molded into a chip shape, and filled in a quartz glass container, and then a Hunter color difference meter (SM color computer manufactured by Suga Test Instruments Co., Ltd.) Measurement was performed using model SM-3) to obtain L and b values of the hunter.
(3) Solution haze Integrating sphere type photoelectric photometry method by dissolving 2.0 g of a sample to be measured in 20 mL of orthochlorophenol and using a quartz cell having a light path length of 10 mm and a haze meter (HGM-2DP type, manufactured by Suga Test Instruments Co., Ltd.) The analysis was performed.

Example 1
A. Nitrogen-containing organic compound 1,3-bis (2,4,6-trimethylphenyl) -2-methoxyimidazolidine (in formula 1, R ¹ is ethylene, Y ¹ is methoxymethylene, X ¹ and X ² are 2, respectively) Synthesis of 4,6-trimethylphenyl) 1,3-bis (2,4,6-trimethylphenyl) imidazolinium chloride (Sigma Aldrich) was added to a 2000 ml three-necked eggplant flask equipped with a stirrer at 25 ° C. in a nitrogen atmosphere. 25 g (72.9 mmol) and 1000 ml of tetrahydrofuran were added to prepare a suspension. To this was added 3.8 g (95 mmol) of potassium hydride (manufactured by Wako Pure Chemical Industries, Ltd.), followed by 2.7 ml (67 mmol) of methanol and stirred for 2 hours. The reaction mixture was filtered to remove the solid, and the filtrate was concentrated to dryness to give a white solid. The crystals obtained by recrystallization from 350 ml of tetrahydrofuran were dried at 60 ° C. under reduced pressure to obtain 6.8 g of the desired product (yield 30%).
B. Polyethylene terephthalate production method 1.0 kg of high purity terephthalic acid (manufactured by Mitsui Chemicals Co., Ltd.) and ethylene glycol (manufactured by Nippon Shokubai Co., Ltd.) of 0.45 kg are charged in advance with about 1.23 kg of bis (hydroxyethyl) terephthalate. Then, the esterification reaction tank maintained at a temperature of 250 ° C. and a pressure of 1.2 × 10 5 Pa was supplied over 4 hours, and after completion of the supply, the esterification reaction was completed over an additional hour. Next, 1.23 kg of the esterification reaction product was transferred to a polycondensation tank.

  Subsequently, an ethylene glycol slurry of titanium oxide particles (manufactured by Fuji Titanium Industry Co., Ltd.) is added to the polycondensation reaction tank to which the esterification reaction product has been transferred, with a particle concentration of 0.3 wt. % Was added. After stirring for 5 minutes, 30 ppm in terms of cobalt atom and 15 ppm in terms of manganese atom were added to a polymer from which an ethylene glycol solution of cobalt acetate (manufactured by Aldrich) and manganese acetate (manufactured by Aldrich) was obtained. After further stirring for 5 minutes, 1.16 g of the nitrogen-containing organic compound was dispersed in 150 ml of ethylene glycol and added (1000 ppm with respect to the resulting polymer). After further stirring for 5 minutes, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol-di-phosphite (Asahi Denka Kogyo Co., Ltd., ADK STAB PEP-36) was added in advance to ethylene glycol. A liquid dispersed at a concentration of 1% by weight was added to the obtained polymer so as to be 10 ppm in terms of phosphorus atoms. Thereafter, while stirring the low polymer at 30 rpm, the reaction system was gradually heated from 250 ° C. to 285 ° 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, returned to normal pressure, the polycondensation reaction was stopped, discharged into cold water in a strand form, and immediately cut to obtain polymer pellets. The time from the start of decompression to the arrival of the predetermined stirring torque was 2.5 hours.

  As shown in Table 1, the polymer obtained had an IV of 0.67 and a solution haze of 0.2%, and there was little foreign matter, and the color tone L value 74 and b value 1.0 were good.

Comparative Examples 1 and 2
1,3,4,6,7,8-Hexahydro-1-methyl-2H-pyrimido [1,2-a] pyrimidine (manufactured by Aldrich) or 4-dimethylaminopyridine (Aldrich) instead of nitrogen-containing organic compound Polymerization was conducted in the same manner as in Example 1 except that In either case, the polymerization time was long due to insufficient activity of the catalyst, and the color tone of the polymer was poor.

Comparative Example 3
Instead of nitrogen-containing organic compound and bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol-di-phosphite, antimony trioxide (manufactured by Sumitomo Metals) and phosphoric acid were converted into polymers, respectively. On the other hand, polymerization was carried out in the same manner as in Example 1 except that 300 ppm and 60 ppm were added. There were very many foreign substances in the obtained polymer.

  The structure A described in Table 1 is Formula 1, the structure B is Formula 3, the structure C is Formula 4, and the phosphorus compound 1 is bis (2,6-di-tert-butyl-4-methylphenyl). ) Pentaerythritol diphosphite (Asahi Denka Kogyo Co., Ltd., Adeka Stub PEP-36).

Example 2
Catalyst preparation and polymerization were performed in the same manner as in Example 1 except that the structure of the nitrogen-containing organic compound was different. The polymerization time was not prolonged, and there was little foreign material, and a polymer having a good color tone was obtained.

In addition, 1,3-dimethyl-2- (2-furyl) imidazolidine which is a nitrogen-containing organic compound (in formula 1, R ¹ is ethylene, Y ¹ is methylene (2-furyl), X ¹ and X ² are respectively Methyl) was purchased from Tokyo Chemical Industry Co., Ltd.

Examples 3-5
Catalyst preparation and polymerization were performed in the same manner as in Example 1 except that the phosphorus compound added in the polymerization step was different. All of them gave a polymer having a good color tone with little foreign matter.

  The structure A described in Table 2 is Formula 1, and the phosphorus compound 1 is bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol-di-phosphite (Asahi Denka Kogyo Co., Ltd.). , Adekastab PEP-36), and phosphorus compound 2 is bis (2,4-di-tert-butylphenyl) pentaerythritol-di-phosphite (manufactured by Asahi Denka Kogyo Co., Ltd., Adekastab PEP-24).

Claims (3)

An aromatic polyester polymerization catalyst, which is a nitrogen-containing organic compound having a structure represented by Formula 1.

(In Formula 1, X ¹ and X ² each independently represent hydrogen or a hydrocarbon group having 1 to 30 carbon atoms. Y ¹ is an ether group, an ester group, a hydroxy group, an alkoxy group, or a carboxyl group. And represents a hydrocarbon group having 1 to 30 carbon atoms containing one or more of these, R ¹ represents a hydrocarbon group having 2 to 30 carbon atoms.) An aromatic polyester polymerization catalyst, which is a nitrogen-containing organic compound having a structure represented by Formula 2.

(In Formula 2, X ¹ and X ² each independently represent hydrogen or a hydrocarbon group having 1 to 30 carbon atoms. Y ² and Y ³ each independently represent hydrogen, or optionally an ether group, an ester group, or a hydroxy group. Represents a hydrocarbon group containing one or more of any one of an alkoxy group and a carboxyl group, provided that the total number of carbon atoms of Y ² and Y ³ is not more than 29. R ² and R ³ are each independently hydrogen Or a hydrocarbon group or a hydrocarbon group connected by a covalent bond, provided that the total number of carbon atoms of R ² and R ³ is 28 or less.)   In the manufacturing method of the aromatic polyester which uses aromatic dicarboxylic acid or its ester-forming derivative, and diol or its ester-forming derivative as a raw material, it uses the polymerization catalyst of Claim 1 or 2 in the arbitrary steps of a process. A method for producing an aromatic polyester, comprising adding at least one selected from a phosphoric acid compound, a phosphonic acid compound, a phosphinic acid compound, and a phosphite compound to a reaction system.