JP2002249559A - Method for continuous polymerization of polyethylene terephthalate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for continuous polymerization of polyethylene terephthalate(PET) having excellent heat stability, color and transparency at a low cost and a high productivity, without using an antimony, germanium, or titanium compound as a main component of the catalyst. SOLUTION: Polyethylene terephthalate is prepared by continuous polymerization using a polycondensation catalyst comprising, as a metal-containing component, at least one selected from the group consisting of aluminum and aluminum compounds, and comprising at least one selected from the group consisting of phenolic compounds.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polyethylene terephthalate (hereinafter referred to as PET) using an aluminum-based catalyst.
). More specifically, without using conventional antimony compounds, germanium compounds, and titanium compounds as the main components of the catalyst, they can be produced with excellent thermal stability, excellent color tone, and at low cost.
The present invention relates to a continuous polymerization method for PET.

[0002]

2. Description of the Related Art PET has excellent properties such as mechanical properties, chemical properties, transparency, heat resistance and gas barrier properties.
It is used in a wide range of fields such as hollow molded articles such as fibers and bottles, films for packaging and industrial use, sheets for packaging and the like, and molding materials for electric and electronic parts.

[0003] PET generally used for such applications
Is made from terephthalic acid and ethylene glycol,
It is produced using an antimony compound, a germanium compound, a titanium compound and a mixture thereof as a polycondensation catalyst.

[0004] Among the above polycondensation catalysts, antimony trioxide is generally widely used. Antimony trioxide is a polycondensation catalyst that is inexpensive and has excellent catalytic activity. However, if this is used as a main component, that is, in an amount of addition to the extent that a practical polymerization rate can be exhibited, metal antimony precipitates during polycondensation, which causes a problem that blackening and foreign matter are generated in polyester. are doing. The above-mentioned foreign substances may cause surface defects when formed into a film, decrease in strength when formed into a fiber, or deteriorate in operability due to stains on a spinneret during spinning.

As a method for solving the above problems, attempts have been made to use antimony trioxide as a polycondensation catalyst and to suppress the occurrence of darkening and foreign matters of polyester. For example, in Japanese Patent No. 2666502,
By using a compound of antimony trioxide, bismuth and selenium as a polycondensation catalyst, generation of black foreign matter in polyethylene terephthalate is suppressed. Further, Japanese Patent Application Laid-Open No. 9-291141 describes that when antimony trioxide containing sodium and iron oxides is used as a polycondensation catalyst, precipitation of antimony metal is suppressed. However, these methods have failed to achieve the purpose of reducing the content of antimony in the polyester.

[0006] Studies have been made on polycondensation catalysts that can replace antimony-based catalysts such as antimony trioxide. For example, titanium compounds and tin compounds represented by tetraalkoxy titanates have already been proposed. However, polyesters produced using these have low thermal stability, and thus are susceptible to thermal degradation during melt molding, and have the problem that the polyester is significantly colored.

As an attempt to overcome such problems when a titanium compound is used as a polycondensation catalyst, for example, Japanese Patent Application Laid-Open No. 55-116722 discloses that a tetraalkoxy titanate is used simultaneously with a cobalt salt and a calcium salt. A method has been proposed. Also, Japanese Patent Laid-Open No. 8-7
No. 3,581, proposes a method in which a tetraalkoxy titanate is used simultaneously with a cobalt compound as a polycondensation catalyst and a fluorescent whitening agent is used. However,
In these techniques, although the coloring of the polyester when the tetraalkoxy titanate is used as the polycondensation catalyst is reduced, it has not been possible to effectively suppress the thermal decomposition of the polyester.

As another attempt to suppress thermal degradation during melt molding of a polyester polymerized by using a titanium compound as a polycondensation catalyst, for example, JP-A-10-259296 discloses a method in which a polyester is polymerized using a titanium compound as a catalyst. A method of adding a phosphorus compound later is disclosed. However, it is not only technically difficult to effectively mix the additive into the polymer after polymerization, but also increases the cost and is not practically used.

It is known that aluminum compounds generally have poor catalytic activity. Among the aluminum compounds,
It has been reported that aluminum chelate compounds have higher catalytic activity as polycondensation catalysts than other aluminum compounds, but that they have sufficient catalytic activity compared to the above-mentioned antimony compounds and titanium compounds. In addition, there is a problem that the polyester which is polymerized for a long time using an aluminum compound as a catalyst has poor thermal stability.

[0010] In order to improve the above-mentioned catalytic activity and thermal stability, a method is disclosed in which an alkali metal compound is used as a polyester polymerization catalyst for an aluminum compound. However, catalysts using this alkali metal compound in combination
In order to obtain a practical catalytic activity, it is necessary to increase the amount of addition. As a result, at least one of the following problems occurs due to the alkali metal compound in the obtained polyester polymer.

1) The amount of foreign matters increases, and when used for fibers, the spinning properties and yarn physical properties are deteriorated, and when used for films, film defects and the like deteriorate. 2) The hydrolysis resistance of the polyester polymer decreases, and the transparency decreases due to the generation of foreign substances. 3) Poor color tone of the polyester polymer, that is, a phenomenon in which the polymer is colored yellow occurs, and when used for a film or the like, there is a problem that the color tone of a molded product is deteriorated. 4) The filter pressure at the time of melting and producing a molded article increases due to clogging of foreign matter, and the productivity also decreases.

[0012] Germanium compounds have already been put to practical use as catalysts which provide polyesters having excellent catalytic activity other than the antimony compounds and not having the above-mentioned problems, but this catalyst is very expensive. And
Since it is easy to distill out of the reaction system during polymerization, the catalyst concentration in the reaction system changes, making it difficult to control the polymerization, and there is a problem in using it as the main component of the catalyst.

Further, as a method for suppressing thermal deterioration during melt molding of polyester, there is a method of removing a catalyst from polyester. As a method for removing a catalyst from polyester, for example, JP-A-10-251394 discloses a method in which a polyester resin is contacted with an extractant which is a supercritical fluid in the presence of an acidic substance.
However, such a method using a supercritical fluid is not preferable because it is technically difficult and leads to an increase in product cost.

In view of the above technical background, PET is desired which does not use an antimony compound, a germanium compound, or a titanium compound as a main component of the catalyst, hardly causes thermal deterioration during melt molding, and has a good color tone.

[0015]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems, and does not use an antimony compound, a germanium compound, or a titanium compound as a main component of a catalyst, and has thermal stability, color tone, and transparency. An object of the present invention is to provide a continuous polymerization method capable of producing PET having excellent properties at low cost and with high productivity.

[0016]

The technical gist of the present invention is as follows.
In order to improve the thermal stability of PET polymerized using a conventional aluminum compound as a polycondensation catalyst, the effect of adding various antioxidants and stabilizers during polymerization was examined. Due to the combination with the compound and / or the phosphorus compound, the aluminum salt of the phosphorus compound, or the compound represented by the above formula 7, the aluminum compound originally having poor catalytic activity has sufficient activity as a polymerization catalyst, and has thermal stability, It has been found that PET having good color tone and transparency can be obtained, and it has been made possible to produce it at low cost and high productivity by a continuous polymerization method.

That is, the present invention relates to aluminum and / or
Alternatively, the method is a continuous polymerization method for PET, wherein the method is a production method using a polycondensation catalyst containing at least one selected from compounds thereof as a metal-containing component and containing at least one selected from phenolic compounds.

Further, PET is produced by using a polycondensation catalyst containing at least one selected from aluminum and / or a compound thereof as a metal-containing component and containing at least one selected from phosphorus compounds.
Is a continuous polymerization method.

Further, there is provided a continuous polymerization method for PET, wherein the method is produced using a polycondensation catalyst containing at least one selected from aluminum salts of phosphorus compounds.

Further, there is provided a method for continuous polymerization of PET, which is produced using a polycondensation catalyst containing at least one compound selected from the compounds represented by the above formula (7).

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the polycondensation catalyst used in the continuous polymerization of PET is aluminum and / or aluminum.
Or a catalyst containing the compound and a phenolic compound,
A catalyst containing aluminum and / or a compound thereof and a phosphorus compound, a catalyst containing an aluminum salt of a phosphorus compound, or a catalyst containing at least one selected from the compounds represented by the above formula (7).

As the aluminum and / or aluminum compound, known aluminum compounds can be used without limitation in addition to metallic aluminum.

Specific examples of the aluminum compound include aluminum formate, aluminum acetate, basic aluminum acetate, aluminum propionate, aluminum oxalate, aluminum acrylate, aluminum laurate, aluminum stearate, aluminum benzoate, and aluminum trichloroacetate. , Aluminum lactate,
Carboxylates such as aluminum citrate and aluminum salicylate; inorganic acid salts such as aluminum chloride, aluminum hydroxide, aluminum hydroxide chloride, aluminum carbonate, aluminum phosphate and aluminum phosphonate; aluminum methoxide, aluminum ethoxide, and aluminum n -Propoxide, aluminum is
aluminum chelate compounds such as o-propoxide, aluminum n-butoxide, aluminum alkoxide such as aluminum t-butoxide, aluminum acetylacetonate, aluminum acetyl acetate, aluminum ethyl acetoacetate, aluminum ethyl acetoacetate di-iso-propoxide, trimethyl aluminum, Organoaluminum compounds such as triethylaluminum and partial hydrolysates thereof,
Aluminum oxide and the like can be mentioned. Of these, carboxylate, inorganic acid salt and chelate compound are preferred,
Among these, aluminum acetate, aluminum chloride, aluminum hydroxide, aluminum hydroxide chloride and aluminum acetylacetonate are particularly preferred.

The amount of the aluminum and / or aluminum compound used is preferably 0.001 to 0.05 mol% based on the total number of moles of the carboxylic acid components such as dicarboxylic acid and polycarboxylic acid in the obtained PET. ,
More preferably, it is 0.005 to 0.02 mol%. If the amount used is less than 0.001 mol%, the catalytic activity may not be sufficiently exhibited. If the amount used is 0.05 mol% or more, the thermal stability and thermo-oxidation stability decrease, and aluminum is caused. In some cases, the generation of foreign matter and the increase in coloring may become a problem. As described above, even when the addition amount of the aluminum component is small, the polymerization catalyst of the present invention is greatly characterized in that it exhibits a sufficient catalytic activity. As a result, thermal stability and thermal oxidation stability are excellent, and foreign substances and coloring due to aluminum can be reduced.

The phenolic compound constituting the polycondensation catalyst is not particularly limited as long as it has a phenol structure. For example, 2,6-di-tert-butyl-4
-Methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,6-dicyclohexyl-4-methylphenol, 2,6-diisopropyl-4-ethylphenol, 2,6-di
-tert-amyl-4-methylphenol, 2,6-di-tert-octyl-4-n-propylphenol, 2,6-dicyclohexyl
-4-n-octylphenol, 2-isopropyl-4-methyl-
6-tert-butylphenol, 2-tert-butyl-2-ethyl-
6-tert-octylphenol, 2-isobutyl-4-ethyl-
6-tert-hexylphenol, 2-cyclohexyl-4-n-
Butyl-6-isopropylphenol, 1,1,1-tris (4-
Hydroxyphenyl) ethane, 1,1,3-tris (2-methyl
-4-hydroxy-5-tert-butylphenyl) butane, triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-
Hexanediol-bis [3- (3,5-di-tert-butyl-4-
Hydroxyphenyl) propionate], 2,2-thiodiethylenebis [3- (3,5-di-tert-butyl-4,4-hydroxyphenyl) propionate], N, N'-hexamethylenebis (3,5- Di-tert-butyl-4-hydroxy-hydrocinnamide), 1,3,5-tris (2,6-dimethyl-3-hydroxy-4)
-tert-butylbenzyl) isocyanurate, 1,3,5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 1,3,5-tris [(3,5-di- tert-butyl-4
-Hydroxyphenyl) propionyloxyethyl] isocyanurate, tris (4-tert-butyl-2,6-dimethyl-3-hydroxybenzyl) isocyanurate, 2,4-bis (n-octylthio) -6- (4-hydroxy -3,5-di-t
ert-butylanilino) -1,3,5-triazine, tetrakis [methylene (3,5-di-tert-butyl-4-hydroxy) hydrocinnamate] methane, bis [(3,3-bis (3-tert-
Butyl-4-hydroxyphenyl) butyric acid
Glycol ester, N, N'-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyl] hydrazine, 2,2'-oxazamide bis [ethyl-3- (3,5-di- tert-
Butyl-4-hydroxyphenyl) propionate], bis [2-tert-butyl-4-methyl-6- (3-tert-butyl-5)
-Methyl-2-hydroxybenzyl) phenyl] terephthalate, 1,3,5-trimethyl-2,4,6-tris (3,5-di-ter
t-butyl-4-hydroxybenzyl) benzene, 3,9-bis [1,1-dimethyl2- {β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} ethyl]
-2,4,8,10-tetraoxaspiro [5,5] undecane, 2,
2-bis [4- (2- (3,5-di-tert-butyl-4-hydroxycinnamoyloxy)) ethoxyphenyl] propane, β
-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid alkyl ester, tetrakis- [methyl-3-
(3 ', 5'-di-tert-butyl-4-hydroxyphenyl) propionate] Methane, octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 1,1,3-
Tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, thiodiethylene-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], ethylenebis (oxyethylene ) Bis [3- (5-tert-butyl-4)
-Hydroxy-m-tolyl) propionate], hexamethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, triethylene glycol-bis
-[-3- (3'-tert-butyl-4-hydroxy-5-methylphenyl)] propionate, 1,1,3-tris [2-methyl-4- [3-
(3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] -5-tert-butylphenyl] butane.

These may be used in combination of two or more. Of these, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tetrakis- [methyl-3- (3 ′, 5 ′) -Di-tert-butyl
4-Hydroxyphenyl) propionate] Methane and thiodiethylene-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] are preferred.

By adding these phenolic compounds during the polymerization of PET, the catalytic activity of the aluminum compound is improved and the thermal stability of PET is also improved.

The amount of the phenolic compound to be used is 5 × 10 ^{−5 with} respect to the total number of carboxylic acid components such as dicarboxylic acid and polycarboxylic acid in the obtained PET.
To 1 mol%, more preferably 1 × 10 ^{−4 to} 0.5
Mol%. In the present invention, a phosphorus compound may be used together with the phenolic compound.

The phosphorus compound constituting the polycondensation catalyst is not particularly limited, but is a phosphonic acid compound, a phosphinic acid compound, a phosphine oxide compound, a phosphonous acid compound, a phosphinous acid compound, a phosphine compound. The use of one or more compounds selected from the group consisting of the above is preferred because the effect of improving the catalytic activity is large. Among these, the use of one or more phosphonic acid compounds is particularly preferable because the effect of improving the catalytic activity is particularly large.

The above phosphonic acid compounds, phosphinic acid compounds, phosphine oxide compounds, phosphonous acid compounds, phosphinous acid compounds, and phosphine compounds are represented by the following formulas 8 to 13, respectively.

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Embedded image Is a compound having a structure represented by

Examples of the phosphonic acid-based compound include dimethyl methylphosphonate, diphenyl methylphosphonate, dimethyl phenylphosphonate, diethyl phenylphosphonate, diphenyl phenylphosphonate, dimethyl benzylphosphonate, diethyl benzylphosphonate, and the like. .

Examples of the phosphinic acid-based compounds include diphenylphosphinic acid, methyl diphenylphosphinate, phenyl diphenylphosphinate, phenylphosphinic acid, methyl phenylphosphinate, phenyl phenylphosphinate and the like.

Examples of the phosphine oxide compounds include diphenylphosphine oxide, methyldiphenylphosphine oxide, and triphenylphosphine oxide.

Among the phosphinic acid compounds, phosphine oxide compounds, phosphonous acid compounds, phosphinous acid compounds, and phosphine compounds, the phosphorus compounds include:

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Embedded image It is preferable to use a compound represented by the formula:

Of the above-mentioned phosphorus compounds, the use of a compound having an aromatic ring structure is more preferable because the effect of improving the catalytic activity is large.

As the phosphorus compound constituting the above-mentioned polycondensation catalyst, it is preferable to use a compound represented by the following general formulas (20) to (22), since the effect of improving the catalytic activity is particularly large.

[0037]

Embedded image

Embedded image

Embedded image (Wherein R ¹ , R ⁴ , R ⁵ , and R ⁶ each independently represent hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group, a halogen group, an alkoxyl group, or an amino group, .R ² representing the 50 hydrocarbon group, R ³ are each independently hydrogen, a hydrocarbon group having 1 to 50 carbon atoms containing a hydrocarbon group, a hydroxyl group or an alkoxyl group having 1 to 50 carbon atoms. However, The hydrocarbon group may contain an alicyclic structure such as cyclohexyl or an aromatic ring structure such as phenyl or naphthyl.

The phosphorus compound constituting the above-mentioned polycondensation catalyst and
In the above Chemical Formulas 20 to 22, R ¹ , R^Four , R^Five , R
⁶ Are particularly preferably compounds having a ring structure having an aromatic ring structure.
No.

Examples of the phosphorus compound constituting the above-mentioned polycondensation catalyst include dimethyl methylphosphonate, diphenyl methylphosphonate, dimethyl phenylphosphonate, diethyl phenylphosphonate, diphenyl phenylphosphonate, dimethyl benzylphosphonate, diethyl benzylphosphonate. , Diphenylphosphinic acid, methyl diphenylphosphinate, phenyl diphenylphosphinate, phenylphosphinic acid, methyl phenylphosphinate, phenyl phenylphosphinate, diphenylphosphine oxide, methyldiphenylphosphine oxide, triphenylphosphine oxide and the like. Of these, dimethyl phenylphosphonate and diethyl benzylphosphonate are particularly preferred.

The amount of the phosphorus compound to be used is preferably 5 × 10 ⁻⁵ to 1 mol%, more preferably ⁵ mol%, based on the number of moles of all carboxylic acid components such as dicarboxylic acid and polycarboxylic acid in the obtained PET. Is 1 × 10 ^{−4 to} 0.5 mol%.

The phosphorus compound having a phenol moiety in the same molecule that constitutes the polycondensation catalyst is not particularly limited as long as it is a phosphorus compound having a phenol structure. -Based compound, phosphinic acid-based compound, phosphine oxide-based compound, phosphonous acid-based compound, phosphinous acid-based compound, and the use of one or more compounds selected from the group consisting of phosphine-based compounds have the effect of improving the catalytic activity. Large and preferred. Among these, the use of a phosphonic acid-based compound having one or more phenol moieties in the same molecule is particularly preferable because the effect of improving the catalytic activity is particularly large.

Examples of the phosphorus compound having the phenol moiety constituting the polycondensation catalyst in the same molecule include compounds represented by the following general formulas (23) to (25). Among these, the use of the following formula is particularly preferable because the catalytic activity is improved.

[0043]

Embedded image

Embedded image

Embedded image (Wherein, R ¹ represents a hydrocarbon group having 1 to 50 carbon atoms including a phenol moiety, a hydroxyl group, a halogen group, an alkoxyl group, an amino group, or another substituent; Represents a hydrocarbon group.
⁴ , R ⁵ and R ⁶ are each independently hydrogen, having 1 to 50 carbon atoms.
Having 1 to 5 carbon atoms including a substituent such as a hydrocarbon group, a hydroxyl group, a halogen group, an alkoxyl group or an amino group.
Represents a hydrocarbon group of 0. R ² and R ³ each independently represent hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydrocarbon group having 1 to 50 carbon atoms including a substituent such as a hydroxyl group or an alkoxyl group. However, the hydrocarbon group may include a branched structure, an alicyclic structure such as cyclohexyl, or an aromatic ring structure such as phenyl or naphthyl. The terminals of R ² and R ⁴ may be bonded to each other. ).

Examples of the phosphorus compound having the phenol moiety in the same molecule include, for example, p-hydroxyphenylphosphonic acid, dimethyl p-hydroxyphenylphosphonate, diethyl p-hydroxyphenylphosphonate,
Diphenyl hydroxyphenylphosphonate, bis (p-
(Hydroxyphenyl) phosphinic acid, methyl bis (p-hydroxyphenyl) phosphinate, phenyl bis (p-hydroxyphenyl) phosphinate, p-hydroxyphenylphenylphosphinic acid, methyl p-hydroxyphenylphenylphosphinate, p-hydroxyphenylphenyl Phenyl phosphinate, p-hydroxyphenylphosphinic acid, methyl p-hydroxyphenylphosphinate, phenyl p-hydroxyphenylphosphinate, bis (p-hydroxyphenyl) phosphine oxide, tris (p-hydroxyphenyl) phosphine oxide, bis (p -Hydroxyphenyl) methylphosphine oxide, and compounds represented by the following formulas (26) to (29). Of these,
The compound represented by 8 and dimethyl p-hydroxyphenylphosphonate are particularly preferred.

[0045]

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Embedded image As the compound represented by Chemical formula 28, for example, SANKO-
220 (manufactured by Sanko Corporation) can be used.

By adding a phosphorus compound having such a phenol moiety in the same molecule during the polymerization of PET, the catalytic activity of the aluminum compound is improved,
The thermal stability of ET is also improved.

The amount of the phosphorus compound having the phenol moiety in the same molecule is preferably 5 × 10 ⁻⁵ to 5 mols per mol of all carboxylic acid components such as dicarboxylic acid and polycarboxylic acid in the obtained PET. It is preferably 1 mol%, more preferably 1 × 10 ^{-4 to} 0.5 mol%.

It is preferable to use a phosphorus metal salt compound as the phosphorus compound. The phosphorus metal salt compound is not particularly limited as long as it is a metal salt of a phosphorus compound, but when a metal salt of a phosphonic acid compound is used,
The effect of improving the catalyst activity is large and is preferable. Examples of the metal salt of a phosphorus compound include a monometal salt, a dimetal salt, and a trimetal salt.

In the above phosphorus compounds, the metal part of the metal salt is Li, Na, K, Be, Mg, Sr, B
It is preferable to use a material selected from a, Mn, Ni, Cu, and Zn because the effect of improving the catalytic activity is large. Of these, Li, Na, and Mg are particularly preferred.

It is preferable to use at least one selected from the compounds represented by the following general formula 30 as the phosphorus metal salt compound because the effect of improving the catalytic activity is large.

[0051]

Embedded image (In Chemical Formula 30, R ¹ represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group or a halogen group, or a hydrocarbon group having 1 to 50 carbon atoms including an alkoxyl group or an amino group.)
R ² represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydrocarbon group having 1 to 50 carbon atoms including a hydroxyl group or an alkoxyl group. R ³ is hydrogen, a hydrocarbon group having 1 to 50 carbon atoms,
Represents a hydrocarbon group having 1 to 50 carbon atoms including a hydroxyl group, an alkoxyl group or a carbonyl. l is an integer of 1 or more;
m represents 0 or an integer of 1 or more, and (l + m) is 4 or less. M represents a (l + m) -valent metal cation. n represents an integer of 1 or more. The hydrocarbon group may contain an alicyclic structure or a branched structure such as cyclohexyl or an aromatic ring structure such as phenyl or naphthyl. ).

As the above R ¹ , for example, phenyl,
Examples thereof include 1-naphthyl, 2-naphthyl, 9-anthryl, 4-biphenyl, 2-biphenyl and the like. R above
^{As 2} , for example, hydrogen, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, long-chain aliphatic, phenyl, naphthyl, substituted Phenyl and naphthyl groups,
And a group represented by —CH ₂ CH ₂ OH. R
Examples of ³ O ⁻ include a hydroxide ion, an alcoholate ion, an acetate ion and an acetylacetone ion.

Among the compounds represented by the above general formula 30, it is preferable to use at least one selected from the compounds represented by the following general formula 31.

[0054]

Embedded image (Wherein R ¹ represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group, a halogen group, an alkoxyl group or an amino group, having 1 to 50 carbon atoms.)
R ³ is hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group or an alkoxyl group or a carbon atom having 1 to 5 carbon atoms including carbonyl.
Represents 50 hydrocarbon groups. l represents an integer of 1 or more, m represents 0 or an integer of 1 or more, and (l + m) is 4 or less.
M represents a (l + m) -valent metal cation. The hydrocarbon group may contain an alicyclic structure or a branched structure such as cyclohexyl or an aromatic ring structure such as phenyl or naphthyl. ).

As the above R ¹ , for example, phenyl,
Examples thereof include 1-naphthyl, 2-naphthyl, 9-anthryl, 4-biphenyl, 2-biphenyl and the like. R ³ O ^-
Examples thereof include a hydroxide ion, an alcoholate ion, an acetate ion and an acetylacetone ion.

Among the above-mentioned phosphorus compounds, the use of a compound having an aromatic ring structure is preferred because the effect of improving the catalytic activity is large.

In the above formula 31, M is Li, Na,
K, Be, Mg, Sr, Ba, Mn, Ni, Cu, Zn
Use of one selected from the above is preferred because the effect of improving the catalytic activity is large. Of these, Li, Na, and Mg are particularly preferred.

Examples of the metal salt compounds of phosphorus include lithium [ethyl (1-naphthyl) methylphosphonate], sodium [ethyl (1-naphthyl) methylphosphonate], magnesium bis [(1-naphthyl) methylphosphonate], Potassium [ethyl (2-naphthyl) methyl phosphonate], magnesium bis [(2-naphthyl) methyl phosphonate], lithium [ethyl benzyl phosphonate], sodium [ethyl benzyl phosphonate], magnesium bis [ethyl benzyl phosphonate], Beryllium bis [ethyl benzylphosphonate],
Strontium bis [ethyl benzylphosphonate], manganese bis [ethyl benzylphosphonate], sodium benzylphosphonate, magnesium bis [benzylphosphonic acid], sodium [ethyl (9-anthryl) methylphosphonate], magnesium bis [(9-anthryl) ) Ethyl methyl phosphonate], sodium [ethyl 4-hydroxybenzyl phosphonate], magnesium bis [ethyl 4-hydroxybenzyl phosphonate], sodium [phenyl chlorophenyl phosphonate], magnesium bis [4-chlorobenzyl phosphonate ethyl] ], Sodium [methyl 4-aminobenzylphosphonate], magnesium bis [methyl 4-aminobenzylphosphonate], sodium phenylphosphonate, magnesium bis [phenylphosphonate] Ethyl phosphate], zinc bis [phenylphosphonic acid ethyl] and the like.

Among them, lithium [ethyl (1-naphthyl) methylphosphonate], sodium [ethyl (1-naphthyl) methylphosphonate], magnesium bis [ethyl (1-naphthyl) methylphosphonate], lithium [benzyl-phosphonate] Ethyl], sodium [ethyl benzylphosphonate], magnesium bis [ethyl benzylphosphonate], sodium benzylphosphonate, and magnesium bis [benzylphosphonic acid] are particularly preferred.

The metal salt compound of phosphorus, which is another preferable phosphorus compound constituting the polycondensation catalyst, is at least one selected from compounds represented by the following general formula (32).

[0061]

Embedded image (Wherein R ¹ and R ² each independently represent hydrogen and a hydrocarbon group having 1 to 30 carbon atoms. R ³ represents hydrogen and 1 carbon atom.
Represents a hydrocarbon group having 1 to 50 carbon atoms including a hydrocarbon group of 50 to 50, a hydroxyl group or an alkoxyl group. R ⁴ is hydrogen,
It represents a hydrocarbon group having 1 to 50 carbon atoms, including a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group, an alkoxyl group or carbonyl. Examples of R ⁴ O ⁻ include a hydroxide ion,
Examples include alcoholate ion, acetate ion and acetylacetone ion. l represents an integer of 1 or more, m represents 0 or an integer of 1 or more, and (l + m) is 4 or less. M represents a (l + m) -valent metal cation. n represents an integer of 1 or more. The hydrocarbon group may contain an alicyclic structure or a branched structure such as cyclohexyl or an aromatic ring structure such as phenyl or naphthyl. ).

Among these, it is preferable to use at least one selected from compounds represented by the following general formula 33.

[0063]

Embedded image (In Formula 33, M ^{n +} represents an n-valent metal cation. N represents 1, 2, 3, or 4.)

In the above formulas 32 and 33, M is
Li, Na, K, Be, Mg, Sr, Ba, Mn, N
It is preferable to use a material selected from i, Cu, and Zn because the effect of improving the catalytic activity is large. Of these, Li, N
a and Mg are particularly preferred.

Examples of the specific phosphorus metal salt compounds include lithium [ethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate] and sodium [3,5-di-tert-butyl-4-ethyl]. Ethyl hydroxybenzylphosphonate], sodium [3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid], potassium [3,5-di-
Ethyl tert-butyl-4-hydroxybenzylphosphonate], magnesium bis [3,5-di-tert-butyl-4]
Ethyl-hydroxybenzylphosphonate], magnesium bis [3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid], beryllium bis [3,5-di-tert-
Methyl butyl-4-hydroxybenzylphosphonate],
Strontium bis [3,5-di-tert-butyl-4-hydroxybenzylphosphonate ethyl], barium bis [3,5-di-tert-butyl-4-hydroxybenzylphosphonate phenyl], manganese bis [3,5 -Di-tert-
Ethyl butyl-4-hydroxybenzylphosphonate],
Nickel bis [3,5-di-tert-butyl-4-hydroxybenzylphosphonate ethyl], copper bis [3,5-di-te
ethyl rt-butyl-4-hydroxybenzylphosphonate], zinc bis [3,5-di-tert-butyl-4-hydroxybenzylphosphonate] and the like. Among them, lithium [3,5-di-tert-butyl-4-]
Ethyl hydroxybenzylphosphonate], sodium [ethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate], magnesium bis [3,5-di-tert]
-Butyl-4-ethyl hydroxybenzylphosphonate]
Is particularly preferred.

Another embodiment of the polycondensation catalyst used in the present invention is a polyester polymerization catalyst comprising at least one selected from aluminum salts of phosphorus compounds. An aluminum salt of a phosphorus compound may be used in combination with another aluminum compound, a phosphorus compound, a phenol compound or the like.

The aluminum salt of a phosphorus compound, which is a preferable component constituting the polycondensation catalyst, is not particularly limited as long as it is a phosphorus compound having an aluminum portion.
It is preferable to use an aluminum salt of a phosphonic acid compound because the effect of improving the catalytic activity is large. Examples of the aluminum salt of the phosphorus compound include a monoaluminum salt, a dialluminum salt, and a trialuminum salt.

Among the above aluminum salts of phosphorus compounds, the use of a compound having an aromatic ring structure is preferred because the effect of improving the catalytic activity is large.

As the aluminum salt of the phosphorus compound constituting the above-mentioned polymerization catalyst, it is preferable to use at least one selected from compounds represented by the following general formula 34 because the effect of improving the catalytic activity is large.

[0070]

Embedded image (In Chemical Formula 34, R ¹ represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group or a halogen group, or a hydrocarbon group having 1 to 50 carbon atoms including an alkoxyl group or an amino group.)
R ² represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydrocarbon group having 1 to 50 carbon atoms including a hydroxyl group or an alkoxyl group. R ³ is hydrogen, a hydrocarbon group having 1 to 50 carbon atoms,
Represents a hydrocarbon group having 1 to 50 carbon atoms including a hydroxyl group, an alkoxyl group or a carbonyl. l is an integer of 1 or more;
m represents 0 or an integer of 1 or more, and (l + m) is 3. n represents an integer of 1 or more. The hydrocarbon group may contain an alicyclic structure or a branched structure such as cyclohexyl or an aromatic ring structure such as phenyl or naphthyl. ).

As the above R ¹ , for example, phenyl,
Examples include 1-naphthyl, 2-naphthyl, 9-anthryl, 4-biphenyl, 2-biphenyl and the like. R above
^{As 2} , for example, hydrogen, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, long-chain aliphatic, phenyl, naphthyl, substituted Phenyl and naphthyl groups,
And a group represented by —CH ₂ CH ₂ OH. Examples of R ³ O ⁻ include a hydroxide ion, an alcoholate ion, an ethylene glycolate ion, an acetate ion and an acetylacetone ion.

Examples of the aluminum salt of the phosphorus compound include an aluminum salt of ethyl (1-naphthyl) methylphosphonate, an aluminum salt of ethyl (1-naphthyl) methylphosphonate, an aluminum salt of ethyl (2-naphthyl) methylphosphonate, and benzylphosphonate. Aluminum salt of ethyl acid, aluminum salt of benzylphosphonic acid, (9-
Anthryl) aluminum salt of ethyl methylphosphonate, aluminum salt of ethyl 4-hydroxybenzylphosphonate, aluminum salt of ethyl 2-methylbenzylphosphonate, aluminum salt of phenyl 4-chlorobenzylphosphonate, methyl 4-aminobenzylphosphonate Aluminum salts, aluminum salts of ethyl 4-methoxybenzylphosphonate, aluminum salts of ethyl phenylphosphonate and the like can be mentioned.

Of these, aluminum salts of ethyl (1-naphthyl) methylphosphonate and aluminum salts of ethyl benzylphosphonate are particularly preferred.

Another embodiment of the polycondensation catalyst used in the present invention is a polyester polymerization catalyst comprising at least one selected from aluminum salts of phosphorus compounds represented by the following general formula 35. The aluminum salt of the phosphorus compound may be used in combination with another aluminum compound, a phosphorus compound, a phenol compound, or the like.

[0075]

Embedded image (In Chemical Formula 35, R ¹ and R ² each independently represent hydrogen or a hydrocarbon group having 1 to 30 carbon atoms. R ³ represents hydrogen or 1 carbon atom.
Represents a hydrocarbon group having 1 to 50 carbon atoms including a hydrocarbon group of 50 to 50, a hydroxyl group or an alkoxyl group. R ⁴ is hydrogen,
It represents a hydrocarbon group having 1 to 50 carbon atoms, including a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group, an alkoxyl group or carbonyl. l represents an integer of 1 or more, m represents 0 or an integer of 1 or more, and (l + m) is 3. n represents an integer of 1 or more. The hydrocarbon group may contain an alicyclic structure or a branched structure such as cyclohexyl or an aromatic ring structure such as phenyl or naphthyl. ).

Among these, it is preferable to use at least one selected from compounds represented by the following general formula 36.

[0077]

Embedded image (Wherein, R ³ represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group or an alkoxyl group having 1 to 50 carbon atoms.
Represents a hydrocarbon group. R ⁴ represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group or an alkoxyl group or a hydrocarbon group having 1 to 50 carbon atoms including carbonyl. l is 1
Or an integer greater than or equal to 0 and m represents an integer greater than or equal to 1 and (l +
m) is 3. The hydrocarbon group may contain an alicyclic structure or a branched structure such as cyclohexyl or an aromatic ring structure such as phenyl or naphthyl. ).

The above R^Three For example, hydrogen, methyl
, Ethyl, propyl, isopropyl, n-butyl
Tyl group, sec-butyl group, tert-butyl group, long chain
Aliphatic, phenyl, naphthyl, substituted
Nyl group, naphthyl group, -CH _Two CH_Two Group represented by OH
And the like. R above^Four O^- For example,
Hydroxide ion, alcoholate ion, ethylene glycol
Rate ion, acetate ion and acetylacetone ion
On and the like.

Examples of the aluminum salt of the phosphorus compound include an aluminum salt of ethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate and an aluminum salt of 3,5-di-tert-butyl.
Aluminum salt of methyl butyl-4-hydroxybenzylphosphonate, aluminum salt of isopropyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate,
Aluminum salts of phenyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, aluminum salts of 3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid and the like can be mentioned.

Of these, 3,5-di-tert-butyl-
Aluminum salts of ethyl 4-hydroxybenzylphosphonate and methyl salts of methyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate are particularly preferred.

It is preferable to use a phosphorus compound having at least one P—OH bond as the phosphorus compound. The phosphorus compound having at least one P-OH bond is not particularly limited as long as it is a phosphorus compound having at least one P-OH in the molecule. Among these phosphorus compounds, the use of a phosphonic acid-based compound having at least one P-OH bond is preferable because the effect of improving the catalytic activity is large.

Of the above-mentioned phosphorus compounds, the use of a compound having an aromatic ring structure is preferred because the effect of improving the catalytic activity is large.

When at least one selected from the compounds represented by the following general formula 37 is used as the phosphorus compound having at least one P-OH bond constituting the polycondensation catalyst, the effect of improving the catalytic activity is improved. Large and preferred.

[0084]

Embedded image (In Chemical Formula 37, R ¹ represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group or a halogen group, or a hydrocarbon group having 1 to 50 carbon atoms including an alkoxyl group or an amino group.
R ² represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydrocarbon group having 1 to 50 carbon atoms including a hydroxyl group or an alkoxyl group. n represents an integer of 1 or more. The hydrocarbon group may contain an alicyclic structure or a branched structure such as cyclohexyl or an aromatic ring structure such as phenyl or naphthyl. ).

As the above R ¹ , for example, phenyl,
Examples thereof include 1-naphthyl, 2-naphthyl, 9-anthryl, 4-biphenyl, 2-biphenyl and the like. R above
^{As 2} , for example, hydrogen, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, long-chain aliphatic, phenyl, naphthyl, substituted Phenyl and naphthyl groups,
And a group represented by —CH ₂ CH ₂ OH.

Among the above-mentioned phosphorus compounds, the use of a compound having an aromatic ring structure is preferred because the effect of improving the catalytic activity is large.

Examples of the phosphorus compound having at least one P—OH bond include ethyl (1-naphthyl) methylphosphonate, (1-naphthyl) methylphosphonic acid, ethyl (2-naphthyl) methylphosphonate, ethyl benzylphosphonate, and benzylphosphonate. Acid, ethyl (9-anthryl) methyl phosphonate, ethyl 4-hydroxybenzyl phosphonate, ethyl 2-methylbenzyl phosphonate, phenyl 4-chlorobenzyl phosphonate, methyl 4-aminobenzyl phosphonate, ethyl 4-methoxybenzyl phosphonate And the like. Among them, ethyl (1-naphthyl) methylphosphonate and ethyl benzylphosphonate are particularly preferred.

Further, preferred phosphorus compounds include P-
Specific phosphorus compounds having at least one OH bond are exemplified. The specific phosphorus compound having at least one P-OH bond, which is a preferable phosphorus compound constituting the polycondensation catalyst, means at least one compound selected from the compounds represented by the following general formula 38. .

[0089]

Embedded image (In Chemical Formula 38, R ¹ and R ² each independently represent hydrogen or a hydrocarbon group having 1 to 30 carbon atoms. R ³ represents hydrogen or 1 carbon atom.
Represents a hydrocarbon group having 1 to 50 carbon atoms including a hydrocarbon group of 50 to 50, a hydroxyl group or an alkoxyl group. n represents an integer of 1 or more. The hydrocarbon group may contain an alicyclic structure or a branched structure such as cyclohexyl or an aromatic ring structure such as phenyl or naphthyl. ).

Among these, it is preferable to use at least one selected from compounds represented by the following general formula 39.

[0091]

Embedded image (In the chemical formula 39, R ³ represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group or an alkoxyl group having 1 to 50 carbon atoms.
Represents a hydrocarbon group. The hydrocarbon group may contain an alicyclic structure or a branched structure such as cyclohexyl or an aromatic ring structure such as phenyl or naphthyl. ).

The above R^Three For example, hydrogen, methyl
, Ethyl, propyl, isopropyl, n-butyl
Tyl group, sec-butyl group, tert-butyl group, long chain
Aliphatic, phenyl, naphthyl, substituted
Nyl group, naphthyl group, -CH _Two CH_Two Group represented by OH
And the like.

The specific phosphorus compounds having at least one P-OH bond include ethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate and 3,5-di-tert-butyl-4ethyl. Methyl-hydroxybenzylphosphonate, 3,5-di-tert-butyl-4-isopropyl-hydroxybenzylphosphonate, 3,5-di-tert-butyl-
Examples include phenyl 4-hydroxybenzylphosphonate, octadecyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, and 3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid. Among these,
Ethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate and methyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate are particularly preferred.

Preferred phosphorus compounds include those represented by Chemical Formula 4
And a phosphorus compound represented by 0.

[0095]

Embedded image (Wherein R ¹ represents a hydrocarbon group having ¹ to 49 carbon atoms, or a hydrocarbon group having ¹ to 49 carbon atoms including a hydroxyl group, a halogen group, an alkoxyl group, or an amino group;
² and R ³ are each independently hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, 1 to 1 carbon atoms including a hydroxyl group or an alkoxyl group.
Represents 50 hydrocarbon groups. The hydrocarbon group may have an alicyclic structure, a branched structure, or an aromatic ring structure. ).

More preferably, at least one of R ¹ , R ² and R ^{3 in} the chemical formula 40 is a compound containing an aromatic ring structure.

Specific examples of the phosphorus compound include the following chemical formulas 41 to 46:

Embedded image

Embedded image

Embedded image

Embedded image

Embedded image

Embedded image Indicated by

The phosphorus compound having a higher molecular weight is more preferable because it is less likely to be distilled off during polymerization.

Another phosphorus compound that is preferably used as a polycondensation catalyst is at least one phosphorus compound selected from compounds represented by the following general formula (47).

[0100]

Embedded image (In Chemical Formula 47, R ¹ and R ² each independently represent hydrogen or a hydrocarbon group having 1 to 30 carbon atoms. R ³ and R ⁴ each independently represent hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, or a hydroxyl group. Or a hydrocarbon group having 1 to 50 carbon atoms including an alkoxyl group, n represents an integer of 1 or more, and the hydrocarbon group includes an alicyclic structure such as cyclohexyl or a branched structure, or an aromatic ring structure such as phenyl or naphthyl. May be used.)

Of the above formulas 47, it is preferable to use at least one compound selected from the compounds represented by the following general formula 48 because the effect of improving the catalytic activity is high.

[0102]

Embedded image (In Chemical Formula 48, R ³ and R ⁴ each independently represent hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydrocarbon group having 1 to 50 carbon atoms including a hydroxyl group or an alkoxyl group. The hydrocarbon group is cyclohexyl or the like. May contain an alicyclic structure, a branched structure, or an aromatic ring structure such as phenyl or naphthyl.).

The above R ³ and R ⁴ are, for example, hydrogen,
Short-chain aliphatic groups such as methyl group and butyl group, long-chain aliphatic groups such as octadecyl, phenyl group, naphthyl group, substituted phenyl group and aromatic group such as naphthyl group, -CH ₂ C
And a group represented by H ₂ OH.

As the specific phosphorus compound, 3,5-
Diisopropyl di-tert-butyl-4-hydroxybenzylphosphonate, di-n-butyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, 3,5-di-te
dioctadecyl rt-butyl-4-hydroxybenzylphosphonate; diphenyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate;

Among them, 3,5-di-tert-butyl-
Dioctadecyl 4-hydroxybenzylphosphonate, 3,
Diphenyl 5-di-tert-butyl-4-hydroxybenzylphosphonate is particularly preferred.

Another phosphorus compound that is preferably used as a polycondensation catalyst is at least one phosphorus compound selected from the compounds represented by Chemical Formulas 49 and 50.

[0107]

Embedded image

Embedded image Compounds represented by the above chemical formula 49 include Irgano
x1222 (Ciba Specialty Chemicals) is commercially available. As the compound represented by Chemical Formula 50, Irganox 1425 (manufactured by Ciba Specialty Chemicals) is commercially available.

That is, by using the above phosphorus compound in combination, a sufficient catalytic effect can be exerted even if the amount of aluminum added in the polyester polymerization catalyst is small.

The amount of the phosphorus compound to be used is preferably 0.0001 to 0.1 mol%, more preferably 0.005 to 0.1 mol%, based on the total number of moles of the constituent units of the dicarboxylic acid component constituting the polyester.
More preferably, it is 0.05 mol%. If the amount of the phosphorus compound is less than 0.0001 mol%, the effect of addition may not be exhibited. On the other hand, if it is added in excess of 0.1 mol%, the catalytic activity as a polyester polymerization catalyst may be reduced. Further, the tendency of the decrease varies depending on the amount of aluminum used and the like.

Without using a phosphorus compound, an aluminum compound is used as a main catalyst component, the amount of the aluminum compound used is reduced, and a cobalt compound is further added to reduce the thermal stability when an aluminum compound is used as a main catalyst. It is considered to prevent coloring by
If the cobalt compound is added to such an extent that it has a sufficient catalytic activity, the thermal stability also decreases. Therefore, it is difficult to achieve both using this technique.

The use of the phosphorus compound having the above-mentioned specific chemical structure does not cause problems such as a decrease in thermal stability and the generation of foreign matter, and a sufficient catalytic effect can be obtained even when the amount of the metal-containing component added as aluminum is small. A polycondensation catalyst is obtained, and by using PET polymerized with this polycondensation catalyst, the thermal stability of PET after melt molding is improved.

Further, even if a phosphoric acid ester such as phosphoric acid or trimethyl phosphoric acid is added instead of the phosphorus compound, the effect of the addition is not observed. Further, the phosphorus compound in the range of the preferred addition amount, a conventional antimony compound,
Even when used in combination with a metal-containing polyester polycondensation catalyst such as a titanium compound, a tin compound, and a germanium compound, the effect of promoting the melt polymerization reaction is not recognized.

On the other hand, in the present invention, aluminum or a compound thereof is further added to a small amount of at least one selected from alkali metals, alkaline earth metals and compounds thereof.
It is also a preferred embodiment to coexist a species as the second metal-containing component. The coexistence of such a second metal-containing component in the catalyst system increases the catalytic activity in addition to the effect of suppressing the production of diethylene glycol, and thus provides a catalyst component with a higher reaction rate, which is effective for improving productivity. .

It is known that a catalyst having sufficient catalytic activity can be obtained by adding an alkali metal compound or an alkaline earth metal compound to an aluminum compound. The use of such a known catalyst provides a polyester having excellent thermal stability. However, a known catalyst using an alkali metal compound or an alkaline earth metal compound in combination has a problem in that the amount of catalyst added is increased in order to obtain practical catalytic activity. Need more.

When an alkali metal compound is used in combination, the amount of foreign matters caused by the compound tends to increase. In addition, when an alkaline earth metal compound is used in combination, in order to obtain practical activity, the thermal stability and thermal oxidative stability of the obtained PET are reduced, the coloring by heating is large, and the generation of foreign substances is caused. The amount also increases.

When an alkali metal, an alkaline earth metal, or a compound thereof is added, the amount M (mol%) used is 1 × 10 ^{− based on the} number of moles of all the polycarboxylic acid units constituting the polyester. It is preferably at least ⁶ and less than 0.1 mol%, more preferably 5 × 10 ^-6 to
0.05 mol%, more preferably 1 × 10 ⁻⁵ to
0.03 mol%, particularly preferably 1 × 10 ⁻⁵ to
0.01 mol%.

That is, since the addition amount of the alkali metal or the alkaline earth metal is small, the reaction rate can be increased without causing problems such as a decrease in thermal stability, generation of foreign matter, and coloring. Further, problems such as a decrease in hydrolysis resistance do not occur.

When the amount M of the alkali metal, alkaline earth metal, or compound thereof is 0.1 mol% or more, the thermal stability is reduced, the generation of foreign substances and coloration, and the hydrolysis resistance is reduced. A problem may occur in product processing.
If M is less than 1 × 10 ⁻⁶ mol%, the effect is not clear even if added.

The alkali metal and alkaline earth metal constituting the second metal-containing component which is preferably used in addition to the aluminum or the compound thereof include Li, N
It is preferably at least one selected from a, K, Rb, Cs, Be, Mg, Ca, Sr, and Ba, and more preferably an alkali metal or a compound thereof.

When an alkali metal or its compound is used, Li, Na and K are particularly preferred as the alkali metal. Examples of the alkali metal or alkaline earth metal compounds include, for example, saturated aliphatic carboxylate such as formic acid, acetic acid, propionic acid, butyric acid, and oxalic acid, and unsaturated aliphatic carboxylate such as acrylic acid and methacrylic acid. ,
Aromatic carboxylate such as benzoic acid, halogen-containing carboxylate such as trichloroacetic acid, hydroxycarboxylate such as lactic acid, citric acid, salicylic acid, carbonic acid, sulfuric acid, nitric acid, phosphoric acid, phosphonic acid, hydrogen carbonate, phosphoric acid Hydrogen, hydrogen sulfide, sulfurous acid, thiosulfuric acid, hydrochloric acid, hydrobromic acid, chloric acid,
Inorganic acid salts such as bromic acid, 1-propanesulfonic acid, 1-
Pentanesulfonic acid, organic sulfonates such as naphthalenesulfonic acid, organic sulfates such as lauryl sulfate, methoxy, ethoxy, n-propoxy, iso-propoxy,
Examples include alkoxides such as n-butoxy and tert-butoxy, chelate compounds with acetylacetonate and the like, hydrides, oxides and hydroxides.

When strong alkalis such as hydroxides are used among these alkali metals, alkaline earth metals or compounds thereof, they are less likely to be dissolved in organic solvents such as diols such as ethylene glycol or alcohols. Therefore, an aqueous solution must be added to the polymerization system, which may cause a problem in the polymerization step.

Further, when a highly alkaline substance such as a hydroxide is used, the polyester is liable to undergo side reactions such as hydrolysis during the polymerization, and the polymerized polyester tends to be colored. Also tends to decrease.

Accordingly, the above-mentioned alkali metals or compounds thereof, alkaline earth metals or compounds suitable as alkaline earth metals include saturated aliphatic carboxylate salts, unsaturated aliphatic carboxylate salts and aromatic aliphatic carboxylate salts of alkali metals or alkaline earth metals. Group carboxylate, halogen-containing carboxylate, hydroxycarboxylate, sulfuric acid, nitric acid, phosphoric acid, phosphonic acid, hydrogen phosphate, hydrogen sulfide, sulfurous acid, thiosulfuric acid, hydrochloric acid, hydrobromic acid, chloric acid, bromic acid Inorganic acid salts, organic sulfonates, organic sulfates, chelating compounds, and oxides of choice. Among these, from the viewpoints of ease of handling and availability, it is preferable to use an alkali metal or alkaline earth metal saturated aliphatic carboxylate, particularly an acetate.

The PET produced by the continuous polymerization method of the present invention further comprises a cobalt compound containing a cobalt atom as a PE.
In a preferred embodiment, it is added in an amount of less than 10 ppm based on T.

It is known that cobalt compounds themselves have a certain degree of polymerization activity. However,
When added to such an extent that a sufficient catalytic effect is exhibited as described above, the color tone and the thermal stability of the obtained PET are reduced.

PET produced by the continuous polymerization method of the present invention
Has good color tone and thermal stability, but by adding the cobalt compound in such a small amount as described above and in an addition amount such that the catalytic effect of the addition is not clear, without lowering the color tone, Coloring can be more effectively eliminated.

The purpose of adding the above-mentioned cobalt compound is to eliminate the coloring, and the addition may be made at any stage of the polymerization step or after the completion of the polymerization reaction.

The type of the cobalt compound is not particularly limited, and examples thereof include cobalt acetate, cobalt nitrate, cobalt chloride, cobalt acetylacetonate, cobalt naphthenate and hydrates thereof. Among them,
Particularly, cobalt acetate tetrahydrate is preferable.

It is preferable that the total amount of the aluminum compound and the cobalt atom is 50 ppm or less and the amount of the cobalt atom is less than 10 ppm with respect to the finally obtained PET. More preferably, the total amount of aluminum atoms and cobalt atoms is 40 p
pm or less, and the amount of cobalt atoms is 8 ppm or less, more preferably the total amount of aluminum atoms and cobalt atoms is 25 ppm or less, and the amount of cobalt atoms is 5 ppm or less.

From the viewpoint of thermal stability of PET, the total amount of aluminum atoms and cobalt atoms is preferably less than 50 ppm, and the amount of cobalt atoms is preferably 10 ppm or less. In order to have sufficient catalytic activity, the total amount of aluminum atoms and cobalt atoms is 0.01 ppm.
More is preferred.

The continuous polymerization method for PET used in the present invention can be produced by a conventionally known production method. That is, terephthalic acid and ethylene glycol are directly reacted to remove water, esterified, and then subjected to polycondensation under reduced pressure, or a direct esterification method of reacting dimethyl terephthalate and ethylene glycol. It is produced by a transesterification method in which methyl alcohol is distilled off and transesterification is carried out, followed by polycondensation under reduced pressure.

The melt polycondensation reaction may be performed in one step or may be performed in multiple steps. The solid-state polymerization reaction can be performed in a batch system or a continuous system. The melt polycondensation and the solid phase polymerization may be performed continuously or may be performed separately.

Hereinafter, an example of a preferable continuous polymerization method of PET will be described.

First, the case of producing a low polymer by an esterification reaction will be described. 1.02-1.5 mol per 1 mol of terephthalic acid or its ester derivative,
Preferably, a slurry containing 1.03 to 1.4 moles of ethylene glycol is prepared and continuously supplied to the esterification reaction step.

In the esterification reaction, water or alcohol produced by the reaction is rectified under a condition in which ethylene glycol is refluxed using a multistage apparatus in which at least two esterification reactors are connected in series. It is carried out while removing the system outside the column.

The temperature of the first stage esterification reaction was 240
To 270 ° C., preferably 245 to 265 ° C., at a pressure of 0.
2-3 kg / cm ² G, preferably 0.5-2 kg / c
m ² G. The temperature of the final esterification reaction is usually 250 to 280 ° C, preferably 255 to 275 ° C,
The pressure is usually 0 to 1.5 kg / cm ² G, preferably 0 to 1.5 kg / cm ² G.
1.3 kg / cm ² G. When the reaction is carried out in three or more stages, the reaction conditions of the esterification reaction in the intermediate stage are those between the above-mentioned first-stage reaction conditions and the last-stage reaction conditions.

The increase in the esterification reaction rate in the multi-stage esterification reaction is preferably distributed smoothly in each stage. Finally, it is desirable that the esterification reaction rate reaches 90% or more, preferably 93% or more. By these esterification reactions, a molecular weight of 50
A low-order condensate of about 0 to 5000 is obtained.

Since the above-mentioned esterification reaction uses terephthalic acid as a raw material, the reaction can be carried out without a catalyst by the catalytic action of terephthalic acid as an acid, but it may be carried out in the presence of a polycondensation catalyst.

Further, tertiary amines such as triethylamine, tri-n-butylamine and benzyldimethylamine, tetraethylammonium hydroxide,
When a small amount of a quaternary ammonium hydroxide such as n-butylammonium and trimethylbenzylammonium hydroxide and a basic compound such as lithium carbonate, sodium carbonate, potassium carbonate and sodium acetate are added, dioxyethylene tereph in the main chain of PET is added. It is preferable because the proportion of the tartrate unit can be kept at a relatively low level (5 mol% or less based on all diol components).

Next, when a low polymer is produced by a transesterification reaction, 1.1 to 1.6 mol, preferably 1.2 to 1.5 mol of ethylene glycol is added to 1 mol of dimethyl terephthalate. Is prepared and continuously supplied to the transesterification step.

The transesterification is carried out by using a device in which one or two transesterification reactors are connected in series under conditions where ethylene glycol is distilled back, and methanol produced by the reaction is passed through a rectification column. Perform while removing outside the system. The temperature of the first-stage transesterification reaction is 180 to 250 ° C, preferably 200 to 240 ° C. The temperature of the final transesterification reaction is usually 230 to 270 ° C., preferably 24 to 270 ° C.
0 to 265 ° C., and as a transesterification catalyst, Zn,
Fatty acid salts such as Cd, Mg, Mn, Co, Ca, and Ba;
Carbonate, Pb, Zn, Sb, Ge oxide or the like is used. By these transesterification reactions, the molecular weight is about 200 to 500.
A low degree of condensate is obtained.

Next, the obtained low-order condensate is supplied to a multi-stage liquid phase condensation polymerization step. The polycondensation reaction conditions are as follows: the reaction temperature of the first stage polycondensation is 250 to 290 ° C, preferably 260 to 280 ° C, and the pressure is 500 to 20 Torr.
r, preferably 200 to 30 Torr, and the temperature of the final polycondensation reaction is 265 to 300 ° C, preferably 275
To 295 ° C., and the pressure is 10 to 0.1 Torr, preferably 5 to 0.5 Torr. When the reaction is carried out in three or more stages, the reaction conditions for the polycondensation reaction in the intermediate stage are those between the above-mentioned first-stage reaction conditions and the last-stage reaction conditions. It is preferred that the degree of increase in the intrinsic viscosity reached in each of these polycondensation reaction steps be distributed smoothly.

In the present invention, the catalyst used for producing PET has catalytic activity not only in polycondensation but also in esterification and transesterification. For example,
Polymerization by transesterification of an alkyl ester of a dicarboxylic acid such as dimethyl terephthalate with a glycol such as ethylene glycol is usually carried out in the presence of a transesterification catalyst such as a titanium compound or a zinc compound. Alternatively, the catalyst according to the present invention can be used in the presence of these catalysts. In addition, the catalyst used when producing PET by the continuous polymerization method of the present invention has catalytic activity not only in melt polymerization but also in solid-phase polymerization and solution polymerization. It is possible to

The catalyst used for producing PET by the continuous polymerization method of the present invention can be added to the reaction system at any stage of the polymerization reaction. For example, it can be added to the reaction system before the start of the esterification reaction or transesterification reaction, at any stage during the reaction, or immediately before the start of the polycondensation reaction or during the reaction. In particular, it is preferable to add aluminum or its compound used as a catalyst in the present invention immediately before the start of the polycondensation reaction.

In the present invention, the method of adding the polycondensation catalyst used in the production of PET may be a powdery or neat addition, or a slurry or solution of a solvent such as ethylene glycol. May be added, and there is no particular limitation. Further, aluminum metal or a compound thereof and another component, preferably the phosphorus compound of the present invention, may be added as a premixed mixture or complex, or they may be added separately. The aluminum metal or its compound and another component, preferably a phosphorus compound, may be added to the polymerization system at the same time, or each component may be added at a different time.

In the present invention, the polycondensation catalyst used in the production of PET is other polycondensation catalysts such as an antimony compound, a germanium compound and a titanium compound. It is effective to improve the productivity by shortening the polymerization time, and it is preferable to use a coexistence in a small amount within the range of an addition amount that does not cause a problem in the product such as processability, color tone and the like.

However, the antimony compound is 50 ppm as an antimony atom based on PET obtained by polymerization.
The following amounts can be added. More preferable addition amount is 3
It is 0 ppm or less. 50 ppm of antimony added
As a result, deposition of metallic antimony occurs, and PET is deposited.
This is not preferable because blackening and foreign matter are generated.

The germanium compound can be added in an amount of 20 ppm or less as a germanium atom to PET obtained by polymerization. A more preferable addition amount is 10 pp.
m or less. If the added amount of germanium is 20 ppm or more, it is not preferable because it is disadvantageous in terms of cost.

Suitable antimony compounds include, as preferred compounds, antimony trioxide, antimony pentoxide, antimony acetate, antimony glycooxide, and the like, with the use of antimony trioxide being particularly preferred. Examples of the germanium compound include germanium dioxide and germanium tetrachloride, with germanium dioxide being particularly preferred.

Other polymerization catalysts such as a titanium compound and a tin compound include tetra-n-propyl titanate, tetraisopropyl titanate, tetra-n-butyl titanate, tetraisobutyl titanate, and tetra-butyl titanate.
Examples thereof include tert-butyl titanate, tetracyclohexyl titanate, tetraphenyl titanate, and tetrabenzyl titanate, and the use of tetrabutyl titanate is particularly preferred. Further, as the tin compound, dibutyltin oxide, methylphenyltin oxide, tetraethyltin, hexaethylditin oxide, triethyltin hydroxide, monobutylhydroxytin oxide, triisobutyltin acetate, diphenyltin dilaurate, monobutyltin trichloride, dibutyltin sulfide, Examples thereof include dibutylhydroxytin oxide, methylstannoic acid and ethylstannoic acid, and the use of monobutylhydroxytin oxide is particularly preferable.

The PET in the present invention is a polyester whose acid component is terephthalic acid or its ester-forming derivative and whose glycol component is ethylene glycol.

After the PET is continuously polymerized according to the production method of the present invention, the catalyst is removed from the PET or the catalyst is deactivated by adding a phosphorus compound or the like, thereby further improving the thermal stability of the PET. be able to.

In the PET obtained by the present invention, in the polyester used in the present invention, depending on the purpose of use, inert particles such as inorganic particles, heat-resistant polymer particles, cross-linked polymer particles, and fluorescent enhancers. One or more kinds of various additives such as a whitening agent, an ultraviolet ray inhibitor, an infrared absorbing dye, a heat stabilizer, a surfactant, and an antioxidant can be contained.
As the antioxidant, an antioxidant such as an aromatic amine type or a phenol type can be used, and as the stabilizer, a phosphoric acid type such as phosphoric acid or a phosphoric acid ester type, a sulfur type or an amine type stabilizer can be used. Can be used.

These additives can be added during or after the polymerization of PET or at any stage during the molding of the PET molded article. Which stage is most suitable depends on the properties of the compound and the PET molding. They differ depending on the performance requirements of the body.

After the PET is polymerized according to the method of the present invention, the thermal stability of PET can be further enhanced by removing the catalyst from the PET or deactivating the catalyst by adding a phosphorus compound or the like. it can.

The intrinsic viscosity of PET obtained by the continuous polymerization method of the present invention is preferably from 0.50 to 1.30 dl / g, more preferably from 0.55 to 1.10 dl / g, particularly preferably from 0.60 to 1.10 dl / g. It is in the range of 0.90 dl / g. When the intrinsic viscosity is less than 0.50 dl / g, the mechanical properties of the obtained molded article and the like are poor. On the other hand, if it exceeds 1.30 dl / g, the resin temperature rises during melting by a molding machine or the like, and thermal decomposition becomes severe, so that free low-molecular-weight compounds that affect fragrance retention increase, Problems such as yellowing occur.

The shape of the PET chips obtained by the continuous polymerization method of the present invention may be any of a cylinder type, a square type, a spherical shape, a flat plate shape and the like, and the average particle size thereof is usually 1.5.
To 5 mm, preferably 1.6 to 4.5 mm, and more preferably 1.8 to 4.0 mm. For example, in the case of a cylinder type, the length is 1.5 to 4 mm and the diameter is 1.5.
It is practical to be about 4 mm. In the case of spherical particles, it is practical that the maximum particle size is 1.1 to 2.0 times the average particle size and the minimum particle size is 0.7 times or more the average particle size. Further, the weight of the chip is practically in the range of 15 to 30 mg / piece.

[0158]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction and effects of the present invention will be described below based on embodiments, but the present invention is not limited to these embodiments.

(1) Intrinsic Viscosity (IV) A PET chip was dissolved in a phenol / 1,1,2,2-tetrachloroethane 6/4 (weight ratio) mixed solvent and measured at a temperature of 30 ° C. .

(2) Presence of Sb Particles in PET 40 g of PET chips were dissolved in a mixed solvent of parachlorophenol and tetrachloroethane (75/25 in weight ratio), and the average pore size of hydrophilic polytetrafluoroethylene was 0.1 mm. The solution was filtered through a 1 μm membrane filter. After vacuum drying the residue on the membrane filter, particles trapped in the filter were observed by a scanning electron microscope, and the presence or absence of the Sb element was confirmed by an energy dispersive X-ray microanalyzer (EMAX 2770, manufactured by Horiba, Ltd.).

Example 1 A slurry of high-purity terephthalic acid and ethylene glycol was supplied at a rate of 2000 kg / h to a first esterification reactor containing a reactant in advance, and an N ₂ gas flow rate of 1 m was stirred. ³ / h,
The reaction was carried out at a temperature inside the reactor of about 250 ° C. and a pressure inside the reactor of 0.05 MPa for an average residence time in the reactor of about 3 hours. As a result, the acid value of the obtained oligomer was 1660 eq / ton. The reaction product was transferred to a second esterification reactor, and reacted with stirring at a temperature in the reactor of about 260 ° C. and a pressure of 0.005 MPa in the reactor to obtain an oligomer having an acid value of 650 eq / ton. A 2.5 g / L ethylene glycol solution of aluminum chloride was added in an amount of 0.015 mol% with respect to the acid component in the polyester.
A 10 g / L ethylene glycol solution of nox 1425 (manufactured by Ciba Specialty Chemicals) was continuously supplied to the second esterification reactor separately at 0.02 mol% based on the acid component. This esterification reaction product was continuously supplied to the first polycondensation reactor, and the reaction was carried out with stirring at a temperature in the reactor of about 265 ° C., a pressure in the reactor of 50 hPa, and a residence time in the reactor of about 1 hour.

Further, in the second polycondensation reactor, 18 rpm
The reaction was performed at a temperature of 270 ° C. and a pressure of 10 hPa in the reactor for a residence time of about 1 hour.
Further, in the third polycondensation reactor, stirring was performed at a speed of 18 rpm, the temperature in the reactor was 277 ° C., and the pressure in the reactor was 0.5 to
The polycondensation reaction was performed at 1.5 hPa for about 1 hour. P obtained
The IV of ET was 0.65 dl / g, and the polycondensation catalyst had a practical polymerization activity.

The properties of the obtained PET resin were such that there was no foreign matter due to precipitation of antimony metal, transparency was good, and no darkening was observed.

Comparative Example 1 An intrinsic viscosity of 0.1 was obtained in the same manner as in Example 1 except that antimony trioxide was added as a polycondensation catalyst so that the amount of antimony atoms was 0.05 mol% with respect to the acid component in PET. 65 dl / g of PET was obtained. As antimony trioxide, commercially available diantimony trioxide (manufactured by ALDRICH, purity: 99.999%) was used, and this was stirred with ethylene glycol at 150 ° C. for about 1 hour to a concentration of about 10 g / l. The solution that was dissolved by use was used.

In the obtained PET resin, foreign substances caused by antimony metal were observed, and the PET resin obtained in the examples was used.
Blackening was seen compared to.

[0166]

According to the continuous polymerization method of PET of the present invention, PET excellent in thermal stability, color tone and transparency can be produced at low cost and with high productivity. Therefore, films, bottles,
It can be used for a wide range of applications where PET is currently used, such as fibers.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Shoichi Katamai 2-1-1 Katata, Otsu-shi, Shiga F-term in Toyobo Co., Ltd. Research Laboratory (reference) 4J029 AA03 AB04 AC01 AD01 AD10 AE01 BA03 CB06A JC551 JC561 JC571 JC591 JF021 JF031 JF041 JF071 JF121 JF131 JF151 JF181 JF221 JF541 JF561 KE07 KE09 LA02

Claims (17)

[Claims] 1. A polyethylene produced by using a polycondensation catalyst containing at least one selected from aluminum and / or a compound thereof as a metal-containing component and containing at least one selected from phenolic compounds. A continuous polymerization method of terephthalate. 2. A polyethylene terephthalate produced by using a polycondensation catalyst containing at least one selected from aluminum and / or a compound thereof as a metal-containing component and containing at least one selected from a phosphorus compound. Continuous polymerization method. 3. The continuous polymerization method of polyethylene terephthalate, wherein the polycondensation catalyst according to claim 1 further contains a phosphorus compound. 4. The phosphorus compound is a phosphonic acid compound, a phosphinic acid compound, a phosphine oxide compound,
4. A compound selected from the group consisting of a phosphonous acid compound, a phosphinic acid compound, and a phosphine compound.
A continuous polymerization method for the polyethylene terephthalate according to the above. 5. The phosphorus compound is one or two or more phosphonic acid compounds.
The method for continuous polymerization of polyethylene terephthalate according to any one of the above. 6. The method for continuous polymerization of polyethylene terephthalate according to claim 2, wherein the phosphorus compound is a compound having an aromatic ring structure. 7. The method according to claim 2, wherein the phosphorus compound is one or more selected from the group consisting of compounds represented by the following general formulas (1) to (3). Continuous polymerization method of polyethylene terephthalate. Embedded image Embedded image Embedded image (In the chemical formulas (1) to (3), R ¹ , R ⁴ , R ⁵ , and R ⁶ each independently represent hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group, a halogen group, an alkoxyl group, or an amino group. Represents a hydrocarbon group of 50 to 50. R ² and R ³
Are each independently hydrogen, a hydrocarbon group having 1 to 50 carbon atoms,
Represents a hydrocarbon group having 1 to 50 carbon atoms including a hydroxyl group or an alkoxyl group. However, the hydrocarbon group may contain an alicyclic structure or an aromatic ring structure. ) 8. The method according to claim ¹ , wherein R ¹ , R ⁴ , R ⁵ ,
Continuous polymerization method of polyethylene terephthalate according to claim 7, wherein the R ⁶ is a group having an aromatic ring structure. 9. The method for continuous polymerization of polyethylene terephthalate according to claim 2, wherein the phosphorus compound has a phenol moiety in the same molecule. 10. The phosphorus compound having a phenol moiety in the same molecule is one or more selected from the group consisting of compounds represented by the following general formulas (4) to (6). 10. The continuous polymerization method for polyethylene terephthalate according to item 9. Embedded image Embedded image Embedded image (In Chemical Formulas 4 to 6, R ¹ represents a hydrocarbon group having 1 to 50 carbon atoms including a phenol moiety, a hydroxyl group or a halogen group or an alkoxyl group or an amino group and a hydrocarbon group having 1 to 50 carbon atoms including a phenol moiety. R ⁴ , R ⁵ ,
R ⁶ each independently represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group, a halogen group, an alkoxyl group, or a hydrocarbon group having 1 to 50 carbon atoms including an amino group.
R ² and R ³ each independently represent hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group or an alkoxyl group;
Represents up to 50 hydrocarbon groups. However, the hydrocarbon group may have a branched structure, an alicyclic structure or an aromatic ring structure. R ²
And the terminals of R ⁴ may be bonded to each other. ) 11. A continuous polymerization method for polyethylene terephthalate, which is produced using a polycondensation catalyst containing at least one selected from aluminum salts of phosphorus compounds. 12. A continuous polymerization method for polyethylene terephthalate, which is produced using a polycondensation catalyst containing at least one selected from compounds represented by the following general formula 7. Embedded image (In formula 7, R ¹ and R ² each independently represent hydrogen or a hydrocarbon group having 1 to 30 carbon atoms. R ³ includes hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group or an alkoxyl group. R ⁴ represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group or an alkoxyl group, or a hydrocarbon group having 1 to 50 carbon atoms including a carbonyl; An integer of 1 or more, m represents 0 or an integer of 1 or more, (l + m) is 3. n represents an integer of 1 or more, and the hydrocarbon group contains an alicyclic structure, a branched structure, or an aromatic ring structure. May be.) 13. The method for continuously polymerizing polyethylene terephthalate according to claim 1, wherein the method is carried out using at least two esterification reactors and a multistage liquid phase condensation polymerization reactor. 14. The esterification reactor according to claim 13, wherein the temperature in the reactor is 240 to 270 ° C., the pressure in the reactor is 0 to 0.15 MPa, and the residence time in the reactor is 1.
A continuous polymerization method of polyethylene terephthalate, wherein the esterification reaction is carried out for 5 to 5 hours. 15. In the esterification reactor, the esterification rate is 90% or more, and the molecular weight is 500 to 500.
The continuous polymerization method for polyethylene terephthalate according to claim 13 or 14, wherein the esterification reaction is performed so as to become 0. 16. The multi-stage liquid-phase condensation polymerization reactor according to claim 13, wherein the first-stage liquid-phase condensation polymerization reaction has a temperature in the reactor of 250 to 290 ° C. and a pressure of 30 to 10 in the reactor.
16. The continuous polymerization method for polyethylene terephthalate according to claim 13, wherein the reaction is carried out at 00 hPa and the residence time in the reactor is 0.5 to 2 hours. 17. The multi-stage liquid-phase condensation polymerization reactor according to claim 13, wherein the final-stage liquid-phase condensation polymerization reaction has a reactor internal temperature of 265 to 300 ° C. and a reactor internal pressure of 0.01.
The method for continuous polymerization of polyethylene terephthalate according to claim 13, wherein the reaction is carried out at a pressure of up to 15 Pa and a residence time in the reactor of 0.5 to 3 hours.