JP2001354760A - Catalyst for polymerization of polyester, polyester produced by using it and process for producing polyester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catalyst for the polymerization of a polyester, which comprises mainly a component other than an antimony compound or a germanium compound, is excellent in catalytic activity and gives a polyester producing a melt molded article excellent in thermal stability, a color tone, excellent in oxidation and hydrolysis resistance and containing less foreign substance. SOLUTION: The catalyst for the polymerization of a polyester contains a first metal-containing component comprising at least one compound selected from aluminum and its compounds, has an activity parameter(AP) satisfying the relation of the formula: AP(min)<2T(min), and the use thereof gives a polyethylene terephthalate having a thermal stability parameter (TS) below 0.30 and a color delta b value parameter (Δb), obtained from Hunter b values measured by using a color difference meter, below 4.0.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester polymerization catalyst, a polyester produced by using the same, and a method for producing the polyester. More specifically, the present invention relates to a novel polymerization catalyst containing no germanium or antimony compound as a main component of the catalyst. The present invention relates to a polyester polymerization catalyst, a polyester produced using the same, and a method for producing a polyester.

[0002]

2. Description of the Related Art Polyethylene terephthalate (PE)
T), polyesters represented by polybutylene terephthalate (PBT), polyethylene naphthalate (PEN) and the like are excellent in mechanical properties and chemical properties, and depending on the properties of each polyester, for example, for clothing and It is used in a wide range of fields such as fibers for industrial materials, films and sheets for packaging and magnetic tape, bottles that are hollow molded products, casings for electric and electronic parts, and other engineering plastic molded products.

[0003] A typical polyester which is mainly composed of aromatic dicarboxylic acid and alkylene glycol is, for example, polyethylene terephthalate (PE).
In the case of T), bis (2-hydroxyethyl) terephthalate is produced by esterification or transesterification of terephthalic acid or dimethyl terephthalate with ethylene glycol, and this is polycondensed at high temperature and under vacuum using a catalyst. It is industrially manufactured by a polycondensation method or the like.

Hitherto, antimony trioxide has been widely used as a polyester polymerization catalyst used in such polycondensation of polyester. Antimony trioxide is a catalyst that is inexpensive and has excellent catalytic activity.
When this is used as a main component, that is, in an amount added so that a practical polymerization rate is exhibited, since metallic antimony is precipitated during polycondensation, there is a problem that blackening and foreign matter are generated in polyester. I have. Under such circumstances, a polyester containing no antimony or containing no antimony as a main component of a catalyst is desired.

[0005] The above-mentioned foreign substances in the polyester cause the following problems, for example. (1) In polyester for a film, the precipitation of antimony metal becomes a foreign substance in the polyester and causes not only stains on a die at the time of melt extrusion but also surface defects on the film. In addition, when a raw material such as a hollow molded article is used, it is difficult to obtain a hollow molded article having excellent transparency.

(2) The foreign matter in the polyester for the fiber is
It becomes a foreign substance that causes a decrease in strength in the fiber, and causes stains on a spinneret during spinning. In the production of polyester fibers, a polyester polymerization catalyst free of foreign matter is required mainly from the viewpoint of operability.

As a method for solving the above-mentioned problem, an attempt has been made to use antimony trioxide as a catalyst and to suppress the occurrence of darkening or foreign matter in PET. For example, in Japanese Patent No. 2666502, generation of black foreign matter in PET is suppressed by using a compound of antimony trioxide, bismuth, and selenium as a polycondensation catalyst.
JP-A-9-291141 describes that when antimony trioxide containing sodium and iron oxides is used as a polycondensation catalyst, the precipitation of antimony metal is suppressed. However, these polycondensation catalysts cannot ultimately achieve the purpose of reducing the content of antimony in the polyester.

As a method for solving the problems of the antimony catalyst for applications requiring transparency such as PET bottles, for example, Japanese Patent Application Laid-Open No. 6-279579 discloses a method.
A method is disclosed in which the transparency is improved by defining the amount ratio of the antimony compound to the phosphorus compound. However, the hollow molded article made of the polyester obtained by this method cannot be said to have sufficient transparency.

Japanese Patent Application Laid-Open No. 10-36495 discloses a continuous production method of polyester having excellent transparency using antimony trioxide, phosphoric acid and a sulfonic acid compound. However, the polyester obtained by such a method has a problem that heat stability is poor and the acetaldehyde content of the obtained hollow molded article is high.

[0010] A polycondensation catalyst, which replaces an antimony-based catalyst such as antimony trioxide, has been studied. Titanium compounds and tin compounds represented by tetraalkyl titanates have already been proposed. Polyesters 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 using a titanium compound as a polycondensation catalyst, for example, JP-A-55-116722 discloses a method in which a tetraalkyl titanate is used simultaneously with a cobalt salt and a calcium salt. Has been proposed. Also, JP-A-8-7358
No. 1 proposes a method in which a tetraalkyl titanate is used simultaneously with a cobalt compound as a polycondensation catalyst and a fluorescent brightener is used. However, in these techniques, although the coloring of PET is reduced when a tetraalkyl titanate is used as a polycondensation catalyst, it has not been achieved to effectively suppress the thermal decomposition of PET.

As another attempt to suppress thermal degradation during melt molding of a polyester polymerized using a titanium compound as a catalyst, for example, Japanese Patent Application Laid-Open No. Hei 10-259296 discloses a method in which a polyester is polymerized using a titanium compound as a catalyst and then phosphorus-based. Methods for adding compounds are disclosed. But,
At present, it is not only technically difficult to effectively mix the additive into the polymer after polymerization, but also to increase the cost, so that it is not practically used.

There is also known a technique of adding an alkali metal compound to an aluminum compound to obtain a polyester polymerization catalyst having sufficient catalytic activity. Use of such a known catalyst can provide a polyester having excellent thermal stability.However, a catalyst using this alkali metal compound in combination requires a large amount of addition thereof in order to obtain practical catalytic activity.
As a result, the amount of foreign substances caused by the alkali metal compound in the obtained polyester polymer increases, and when used for fibers, the yarn-forming properties and thread properties are deteriorated, and when used for films, the film properties are deteriorated. In addition, there is a problem that the hydrolysis resistance of the polyester polymer is lowered and the color tone of the polymer is poor, that is, the polymer is colored yellow.

As a catalyst other than an antimony compound, which has excellent catalytic activity and gives a polyester excellent in heat stability and color tone, a germanium compound has already been put to practical use, but this catalyst is said to be very expensive. There is a problem and it is difficult to control the polymerization because the concentration of the catalyst in the reaction system changes because it is easy to distill out of the reaction system during the polymerization. is there.

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 cost.

As described above, the polymerization catalyst comprising a metal component other than antimony and germanium as a main metal component of the catalyst, has excellent catalytic activity and has low thermal stability and color tone which hardly causes thermal deterioration during melt molding. There is a need for polymerization catalysts that provide excellent polyesters.

[0017]

DISCLOSURE OF THE INVENTION The present invention comprises an antimony compound or a germanium compound as a main component of a catalyst, aluminum as a main metal component, excellent catalytic activity, and without deactivation or removal of the catalyst. Polyester with excellent heat stability, thermo-oxidation stability, less foreign matter generation, and excellent hydrolysis resistance, as well as polyester with excellent color tone of melt-molded products, effectively suppressing thermal degradation during melt molding To provide a polyester polymerization catalyst.
The present invention also provides heat stability, thermal oxidation stability, generation of foreign matter, and hydrolysis resistance when performing melt molding of films, bottles and other hollow molded articles, fibers, engineering plastics, and the like using the catalyst. The polyester has improved properties, is less colored even when virgin resin is used, and is less colored even if the waste generated during molding is reused, and a polyester that can provide a product with excellent quality even in color tone, and the polyester polymerization catalyst. An object of the present invention is to provide a method for producing a used polyester.

[0018]

The polyester polymerization catalyst of the present invention contains at least one selected from the group consisting of aluminum and its compounds as a first metal-containing component, and has an activity parameter (AP) of the following formula (1). And the thermal stability parameter (TS) of the polyethylene terephthalate polymerized using the catalyst satisfies the following equation (2), and the color delta b value parameter (Δb) satisfies the following equation (3). And (1) AP (min) <2T (min) In the above formula, the activity parameter AP is 275 ° C. using a predetermined amount of catalyst, and the intrinsic viscosity is 0.65 dl / g at a reduced pressure of 13.3 Pa (0.1 Torr). Shows the time (min) required to polymerize polyethylene terephthalate. T indicates AP when antimony trioxide is used as a catalyst. However, antimony trioxide is added in an amount of 0.05 mol% as antimony atoms to the acid component in the produced polyethylene terephthalate. In the measurement of T, antimony trioxide having a purity of 99% or more, for example, commercially available An
Timony (III) oxide (ALDRICH
CHEMICAL, purity 99.999%) is used.

(2) TS <0.30 In the above formula, TS is a melt-polymerized polyethylene terephthalate (PE) having an intrinsic viscosity (IV) of about 0.65 dl / g.
T) 1 g of a resin chip was placed in a glass test tube, vacuum-dried at 130 ° C. for 12 hours, and then dried under a non-circulating nitrogen atmosphere.
It is calculated | required using the following formula from IV after 2 degreeC and maintaining in a molten state for 2 hours. TS = 0.245 ｛[IV] _f ^-1.47- [IV] _i
^-1.47 ｝ [IV] _i and [IV] _f indicate the IV (dl / g) before and after the melting test, respectively.

The non-circulating nitrogen atmosphere means a non-circulating nitrogen atmosphere. For example, a glass test tube containing a resin chip is connected to a vacuum line, and the pressure becomes 100 Torr after the pressure reduction and the nitrogen filling are repeated 5 times or more. Is sealed with nitrogen.

(3) Δb <4.0 In the above formula, Δb is a value obtained by using a colorimeter using a polyethylene terephthalate (PET) resin chip having an intrinsic viscosity of about 0.65 dl / g obtained by melt polymerization using a predetermined catalyst. The value obtained by subtracting the color b value when antimony trioxide is used as a catalyst from the hunter's b value (color b value) measured as described above is shown. However, antimony trioxide is added in an amount of 0.05 mol% as antimony atoms to the acid component in the produced polyethylene terephthalate. As antimony trioxide, antimony trioxide having a purity of 99% or more, for example,
Commercially available Antimony (III) oxide (AL
DRICH CHEMICAL, purity 99.999
%).

The above-mentioned polyester polymerization catalyst does not contain an antimony compound or a germanium compound as a main component of the catalyst, contains aluminum as a main metal component, has excellent catalytic activity, and does not deactivate or remove the catalyst.
Particularly, as in the production of a film or a PET bottle, it is intended to give a polyester in which thermal deterioration during melt molding is effectively suppressed, heat stability is excellent, and the color tone of the melt-molded product is good.

The method for measuring AP is specifically as follows. 1) (BHET production process) Terephthalic acid and a 2-fold molar amount of ethylene glycol were used, and the esterification rate was 95%.
% Bis (2-hydroxyethyl) terephthalate (B
HET) and a mixture of oligomers (hereinafter, referred to as a BHET mixture). 2) (Catalyst addition step) A predetermined amount of a catalyst is added to the above BHET mixture, and the mixture is stirred at 245 ° C. for 10 minutes under a normal pressure under a nitrogen atmosphere, and then heated to 275 ° C. in 50 minutes. Of the mixture reaction system is gradually reduced to 0.1 Torr. 3) (Polycondensation step) A polycondensation reaction is performed at 275 ° C. and 13.3 Pa, and the IV of polyethylene terephthalate is 0.6.
Polymerize until reaching 5 dl / g. 4) The polymerization time required for the polycondensation step is defined as AP (min). These are performed using a batch-type reactor.

The production of the BHET mixture is performed by a known method. For example, terephthalic acid and a 2-fold molar amount of ethylene glycol are charged into a batch type autoclave equipped with a stirrer, and an esterification reaction is performed while distilling water out of the system at 245 ° C. under a pressure of 0.25 MPa. Manufactured.

By setting the activity parameter AP within the above range, the reaction rate is high, and the time for producing a polyester by polycondensation is reduced. The AP is more preferably 1.5 T or less, further preferably 1.3 T or less, and particularly preferably 1.0 T or less.

The term "predetermined amount of catalyst" means the amount of the catalyst used in a variable amount according to the activity of the catalyst. The amount of the catalyst is small for a highly active catalyst and large for a low active catalyst. . The amount of the catalyst used is at most 0.1 mol% as an aluminum compound based on the number of moles of terephthalic acid. If more is added, the residual amount in the polyester is large,
It is no longer a practical catalyst.

The Δb value obtained from the color b value as an index of yellow coloring is more preferably 3.0 or less, further preferably 2.5 or less, and TS is more preferably 0.25 or less. Especially preferably, it is 0.20 or less.

In the present invention, a PET resin chip used for measuring TS is prepared by quenching from a molten state after the above steps 1) to 3). As the shape of the resin chip used for these measurements, for example, a cylindrical resin chip having a length of about 3 mm and a diameter of about 2 mm is used. Further, as the resin chip for color measurement, after passing through the above steps 1) to 3), a substantially amorphous resin chip produced by rapid cooling from a molten state is used. As a method for obtaining a substantially amorphous resin chip, for example, when taking out the polymer from the reaction system after melt polymerization, quenching with cold water immediately after discharging the polymer from the discharge port of the reaction system, then sufficient cooling For example, a method of holding in cold water for a time and then cutting it into chips may be used. The resin chip thus obtained is transparent in appearance without whitening due to crystallization. The resin chip thus obtained is air-dried on a filter paper or the like at room temperature for about 24 hours, and then used for color measurement.
After the above-mentioned operation, the resin chip remains transparent without any whitening due to crystallization. It should be noted that no additive affecting the appearance such as titanium dioxide is used for the resin chip for color measurement. As the shape of the resin chip used for color measurement, for example, a length of about 3 mm,
A cylindrical resin tip having a diameter of about 2 mm is used.

It is preferable that the above-mentioned catalyst does not contain an alkali metal, an alkaline earth metal, or a compound thereof.

On the other hand, in the present invention, it is preferable that a small amount of at least one selected from alkali metals, alkaline earth metals, and compounds thereof be coexisted as the second metal-containing component in addition to aluminum or its compound. is there. 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 can provide a polyester having excellent thermal stability. However, the known catalyst using an alkali metal compound or an alkaline earth metal compound in combination is not suitable for obtaining a practical catalytic activity. When an alkali metal compound is used, the amount of foreign matter caused by the alkali metal compound increases, and when used for fibers, the spinning properties and yarn properties, and when used for films, the film properties, transparency, and heat stability Properties, thermal oxidation stability, etc. are degraded. Further, the color tone of a melt-formed product such as a fiber or a film deteriorates. When an alkaline earth metal compound is used in combination, the thermal stability and thermal oxidative stability of the obtained polyester are reduced to obtain a practical activity, and the amount of foreign substances generated is increased.

When an alkali metal, an alkaline earth metal or a compound thereof is added, the amount of use M (mol%) is as follows:
It is preferably from 1 × 10 ^{−6 to} less than 0.1 mol%, more preferably from 5 × 10 ^{−6 to} 0.05, based on the number of moles of all the polycarboxylic acid units constituting the polyester.
Mol%, more preferably 1 × 10 ^{−5 to} 0.03.
Mol%, particularly preferably 1 × 10 ^{−5 to} 0.01.
Mol%. Since the added amount of the alkali metal and 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. When the amount M of the alkali metal, alkaline earth metal or compound thereof is 0.1 mol% or more, a decrease in thermal stability, generation of foreign matter and an increase in coloring may cause problems in product processing. When M is less than 1 × 10 ⁻⁶ mol%,
Even if added, the effect is not clear.

The above-mentioned catalyst is preferably one in which a phosphorus compound coexists.
At least one selected from the group consisting of phosphonic acid compounds
It is preferable that one kind coexists. Among these, it is preferable to use a compound having an aromatic ring structure. In particular, it is preferable to coexist at least one selected from phosphonic acid compounds represented by the following general formulas [Chemical Formula 3] and [Formula 4].

[0034]

Embedded image Ph—P (は O) (OR ¹ ) (OR ² ) (wherein R ¹ and R ² each independently represent hydrogen, an alkyl group having 1 to 50 carbon atoms, or an aryl group. Represents.)

Embedded image Me—P (＝ O) (OR ³ ) (OR ⁴ ) (wherein R ³ and R ⁴ each independently represent hydrogen, an alkyl group having 1 to 50 carbon atoms or an aryl group. When a compound having at least one aryl group is used as the compound represented by the above (Chemical Formula 3) or (Chemical Formula 4), it is difficult to be distilled out of the system during the polymerization reaction, so that the addition effect is large. preferable. The phosphorus compound having at least one aryl group is preferably at least one selected from dimethyl phenylphosphonate and diphenyl methylphosphonate, and the use of dimethyl phenylphosphonate is particularly preferred.

Although phosphorus compounds are generally well known as antioxidants, even when these phosphorus compounds are used in combination with a conventional metal-containing polyester polymerization catalyst,
It is not known to greatly promote melt polymerization. In fact, when a polyester compound is melt-polymerized using a typical catalyst for polyester polymerization such as an antimony compound, a titanium compound, a tin compound or a germanium compound as a polymerization catalyst, even if a phosphorus compound is added, a substantially useful level is obtained. No accelerated polymerization is observed.

The amount of the phosphorus compound of the present invention 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 all constituent units of the polycarboxylic acid component of the obtained polyester. More preferably, it is 05 mol%.

When the phosphorus compound of the present invention is used in combination, a catalyst exhibiting a sufficient catalytic effect can be obtained even when the amount of aluminum added in the polyester polymerization catalyst is small. When the amount of the phosphorus compound is less than 0.0001 mol%, the effect of addition may not be exhibited, and when the amount exceeds 0.1 mol%, the catalytic activity as a polyester polymerization catalyst may be reduced. , The trend of decline is
It changes depending on the amount of aluminum used.

There is a technique of reducing the amount of the aluminum compound used and further adding a cobalt compound to prevent the coloring due to a decrease in thermal stability when the aluminum compound is used as a catalyst. When added to such an extent as to have, the thermal stability also decreases. Therefore,
It is difficult to balance both. Further, when the cobalt compound is added to such an extent that it has a sufficient catalytic activity or suppresses yellowing, blackening occurs in the obtained polyester polymer, and the brightness of the polymer is reduced, and the polymer is used for a film or a hollow bottle. There is a problem that the color tone of the molded product sometimes deteriorates. In addition, when the cobalt compound is added to such an extent that it has a sufficient catalytic activity, a problem that the hydrolysis resistance and the like of the obtained polyester polymer are lowered also occurs.

According to the present invention, the use of the phosphorus compound of the present invention does not cause problems such as a decrease in thermal stability and the generation of foreign matters, and is sufficient even when the addition amount of the first metal-containing component as aluminum is small. A polyester polymerization catalyst having a catalytic effect is obtained, and by using this polyester polymerization catalyst, heat stability, thermo-oxidation stability, and foreign matter during melt molding of hollow molded articles such as polyester films and bottles, fibers, and engineering plastics. Generation and color tone are improved. Even if a phosphoric acid ester such as phosphoric acid or trimethyl phosphoric acid is added in place of the phosphorus compound of the present invention, the effect of addition is small and not practical. Further, even when the phosphorus compound of the present invention is used in combination with a conventional antimony compound, a titanium compound, a tin compound, and a metal-containing polyester polymerization catalyst such as a germanium compound in the range of the addition amount of the present invention, the effect of promoting melt polymerization is obtained. It is not allowed. In addition, even if the phosphorus compound of the present invention is used alone in the range of the addition amount of the present invention, no catalytic activity is observed.

[0040]

BEST MODE FOR CARRYING OUT THE INVENTION As the aluminum or aluminum compound constituting the polycondensation catalyst of the present invention, known aluminum compounds can be used without limitation, in addition to metallic aluminum.

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, aluminum trichloroacetate. , Aluminum lactate,
Carboxylates such as aluminum citrate, aluminum salicylate, aluminum chloride, aluminum hydroxide, aluminum hydroxide chloride, poly aluminum chloride,
Inorganic acid salts such as aluminum nitrate, aluminum sulfate, aluminum carbonate, aluminum phosphate and aluminum phosphonate, aluminum methoxide, aluminum ethoxide, aluminum n-propoxide, aluminum iso-propoxide, aluminum n-butoxide, aluminum t-butoxide, etc. Aluminum chelate compounds such as aluminum alkoxide, aluminum acetylacetonate, aluminum acetylacetate, aluminum ethyl acetoacetate, aluminum ethyl acetoacetate diiso-propoxide, organic aluminum compounds such as trimethylaluminum, triethylaluminum, and partial hydrolysates thereof , Aluminum alkoxide or aluminum key Reaction products of over preparative compound and hydroxycarboxylic acid, aluminum oxide, superfine particles of aluminum oxide, aluminum silicate, and composite oxides such as aluminum and titanium, silicon or zirconium and an alkali metal or an alkaline mechanic metals and the like. Of these, carboxylate, inorganic acid salt and chelate compound are preferable, and among these, basic aluminum acetate, aluminum chloride, aluminum hydroxide, aluminum hydroxide chloride and aluminum acetylacetonate are particularly preferable. As the basic aluminum acetate, one stabilized with an additive such as boric acid may be used.

The amount of the aluminum compound to be used is preferably 0.001 to 0.05 mol% with respect to the total number of moles of all constituent units of the carboxylic acid component such as dicarboxylic acid or polycarboxylic acid of the obtained polyester. Preferably it is 0.005 to 0.02 mol%. As described above, the polymerization catalyst of the present invention has a significant feature in that it exhibits sufficient catalytic activity even when the addition amount of the aluminum component or the alkali metal component is small. As a result, by using this polyester polymerization catalyst, generation of foreign matter is suppressed, and thermal stability and
A polyester having excellent thermal oxidation stability and color tone can be produced.

In the present invention, the alkali metal and alkaline earth metal constituting the second metal-containing component which is preferably used in addition to aluminum or its compound include Li, Na, K, Rb, Cs, Be, Mg, Ca,
It is preferably at least one selected from Sr and Ba, and more preferably an alkali metal or a compound thereof. When an alkali metal or a compound thereof is used, it is particularly preferable to use Li, Na, and K. 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, phosphorus Inorganic acid salts such as oxyhydrogen, hydrogen sulfide, sulfurous acid, thiosulfuric acid, hydrochloric acid, hydrobromic acid, chloric acid, and bromic acid, and organic sulfonic acid salts such as 1-propanesulfonic acid, 1-pentanesulfonic acid, and naphthalenesulfonic acid , Organic sulfates such as lauryl sulfate, methoxy, ethoxy, n
-Propoxy, iso-propoxy, n-butoxy, t
alkoxides such as tert-butoxy, chelate compounds with acetylacetonate and the like, hydrides, oxides,
Hydroxide and the like.

When strong alkalis such as hydroxides are used among these alkali metals, alkaline earth metals or compounds thereof, they tend not to be easily dissolved in diols such as ethylene glycol or organic solvents such as alcohols. Therefore, an aqueous solution must be added to the polymerization system, which may cause a problem in the polymerization step. Further, when a strong alkali such as a hydroxide is used, the polyester is liable to undergo side reactions such as hydrolysis during polymerization, and the polymerized polyester tends to be easily colored, and the hydrolysis resistance is also reduced. Tend to. Accordingly, the alkali metal or a compound thereof or an alkaline earth metal or a compound thereof suitable for the present invention is preferably a saturated aliphatic carboxylate, an unsaturated aliphatic carboxylate, or an aromatic salt of an alkali metal or an alkaline earth metal. 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,
It is an inorganic acid salt selected from chloric acid and bromic acid, an organic sulfonate, an organic sulfate, a chelate compound, and an oxide. 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.

In a preferred embodiment, a cobalt compound is added to the polyester polymerization catalyst of the present invention in an amount of less than 10 ppm as a cobalt atom relative to the polyester. The addition amount of the cobalt compound is more preferably less than 5 ppm, and further preferably 3 ppm or less.

It is known that the cobalt compound itself has a certain degree of polymerization activity. However, as described above, if the cobalt compound is added to such an extent that a sufficient catalytic effect is exhibited, the brightness of the obtained polyester polymer is reduced. And thermal stability decreases. The polyester obtained according to the present invention has good color tone and thermal stability, but can be obtained by adding a cobalt compound in an amount such that the catalytic effect of the addition by a small amount as described above is not clear. The coloring can be more effectively eliminated without lowering the brightness of the polyester. The purpose of the cobalt compound in the present invention is to eliminate coloration, and it may be added at any stage of the polymerization or after the completion of the polymerization reaction.

The production of the polyester according to the present invention can be carried out by a method having conventionally known steps except that the polyester polymerization catalyst of the present invention is used as a catalyst. For example, in the polymerization method of PET, a method of esterifying terephthalic acid and ethylene glycol followed by polycondensation,
Alternatively, any of the following methods can be used: a transesterification reaction between an alkyl ester of terephthalic acid such as dimethyl terephthalate and ethylene glycol, followed by polycondensation. The polymerization apparatus may be of a batch type or a continuous type.

The catalyst of the present invention 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, or in combination with these catalysts, the catalyst of the present invention can be used.
Further, the catalyst of the present invention has catalytic activity not only in melt polymerization but also in solid phase polymerization and solution polymerization, and it is possible to produce polyester by any method.

The polycondensation catalyst 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 the transesterification reaction and 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 immediately before the start of the polycondensation reaction.

The method for adding the polycondensation catalyst of the present invention may be a powdery or neat addition, or a slurry or solution addition of a solvent such as ethylene glycol. Not limited. 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. Further, the whole amount of the catalyst may be added at once, or may be added in plural times.

The polycondensation catalyst of the present invention may be used in combination with other polycondensation catalysts such as an antimony compound, a germanium compound and a titanium compound. And coexistence within the range of the addition amount that does not cause is effective in improving productivity by shortening the polymerization time and is preferable.

However, the antimony compound has an antimony atom of 50% with respect to the polyester obtained by polymerization.
It can be added in an amount of ppm or less. A more preferable addition amount is 30 ppm or less. 50 antimony
If it is more than ppm, precipitation of metal antimony occurs,
It is not preferable because darkening and foreign matter are generated in the polyester.

The germanium compound has a germanium atom content of 20 pp with respect to the polyester obtained by polymerization.
m or less. The more preferable addition amount is 1
It is 0 ppm or less. 20 pp of germanium
If it is more than m, it is not preferable because it is disadvantageous in terms of cost.

The antimony compound that can be used in the present invention is not particularly limited, but preferable compounds include antimony trioxide, antimony pentoxide, antimony acetate, antimony glycooxide, and the like. Is preferred. The germanium compound is not particularly limited, but includes germanium dioxide, germanium tetrachloride, and the like, with germanium dioxide being particularly preferred. Both germanium dioxide and crystalline one can be used.

The titanium compound that can be used in the present invention is not particularly limited, but includes tetra-n-propyl titanate, tetra-iso-propyl titanate, tetra-n-butyl titanate, tetra-iso-butyl titanate, tetra-tert. -Butyl titanate, tetracyclohexyl titanate, tetraphenyl titanate, tetrabenzyl titanate, lithium oxalate titanate, potassium oxalate titanate, ammonium oxalate titanate, titanium oxide, titanium and silicon or zirconium or alkali metal or alkaline earth metal Complex oxide, titanium orthoester or condensed orthoester, reaction product of titanium orthoester or condensed orthoester and hydroxycarboxylic acid, titanium orthoester or condensed orthoester Reaction products comprising a stele, a hydroxycarboxylic acid and a phosphorus compound, a polyhydric alcohol having at least two hydroxyl groups with an orthoester or condensed orthoester of titanium, a reaction product comprising a 2-hydroxycarboxylic acid and a base, and the like. Of these, a composite oxide of titanium and silicon, a composite oxide of titanium and magnesium, and a reaction product comprising an orthoester or condensed orthoester of titanium, a hydroxycarboxylic acid, and a phosphorus compound are preferred.

Examples of the tin compound include dibutyltin oxide, methylphenyltin oxide, tetraethyltin, hexaethylditin oxide, triethyltin hydroxide, monobutylhydroxytin oxide, triisobutyltin acetate, diphenyltin dilaurate, monobutyltin trichloride, Examples thereof include dibutyltin sulfide, dibutylhydroxytin oxide, methylstannoic acid and ethylstannoic acid, and the use of monobutylhydroxytin oxide is particularly preferred.

The cobalt compound usable in the present invention is not particularly limited, but specific examples thereof include cobalt acetate, cobalt nitrate, cobalt chloride, cobalt acetylacetonate, cobalt naphthenate and hydrates thereof. No. Among them, cobalt acetate tetrahydrate is particularly preferred.

The polyester referred to in the present invention is one or two or more selected from polyhydric carboxylic acids including dicarboxylic acids and one or more selected from ester-forming derivatives thereof and polyhydric alcohols including glycols. More than one species, or those composed of hydroxycarboxylic acids and their ester-forming derivatives, or those composed of cyclic esters.

As the dicarboxylic acid, oxalic acid, malonic acid,
Succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, dodecanedicarboxylic acid, tetradecanedicarboxylic acid, hexadecanedicarboxylic acid, 3-cyclobutanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid Acid, 1,
Saturated aliphatic dicarboxylic acids exemplified by 2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 2,5-norbornanedicarboxylic acid, dimer acid and the like, and ester-forming derivatives thereof, Unsaturated aliphatic dicarboxylic acids exemplified by fumaric acid, maleic acid, itaconic acid and the like and ester-forming derivatives thereof, orthophthalic acid, isophthalic acid, terephthalic acid, diphenic acid, 1,3-naphthalenedicarboxylic acid, 1,4 -Naphthalenedicarboxylic acid,
1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,
4'-biphenyldicarboxylic acid, 4,4'-biphenylsulfonedicarboxylic acid, 4,4'-biphenyletherdicarboxylic acid, 1,2-bis (phenoxy) ethane-
Aromatic dicarboxylic acids exemplified by p, p'-dicarboxylic acid, pamoic acid, anthracene dicarboxylic acid and the like, and ester-forming derivatives thereof are exemplified.

Among the above dicarboxylic acids, the use of terephthalic acid, isophthalic acid and naphthalenedicarboxylic acid is particularly preferred in view of the physical properties of the resulting polyester, and other dicarboxylic acids may be used as constituents if necessary. I do.

Examples of polycarboxylic acids other than these dicarboxylic acids include ethanetricarboxylic acid, propanetricarboxylic acid, butanetetracarboxylic acid, pyromellitic acid, trimellitic acid, trimesic acid, 3,4,3 ', 4'-biphenyltetracarboxylic acid. Examples include carboxylic acids and their ester-forming derivatives.

As the glycol, ethylene glycol,
1,2-propylene glycol, 1,3-propylene glycol, diethylene glycol, triethylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, 1,4-butylene glycol, 1, 5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,2
-Cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol,
1,4-cyclohexanediethanol, 1,10-decamethylene glycol, 1,12-dodecanediol, polyethylene glycol, polytrimethylene glycol,
Aliphatic glycols exemplified by polytetramethylene glycol, hydroquinone, 4,4'-dihydroxybisphenol, 1,4-bis (β-hydroxyethoxy) benzene, 1,4-bis (β-hydroxyethoxyphenyl) ) Sulfone, bis (p-hydroxyphenyl)
Ether, bis (p-hydroxyphenyl) sulfone,
Bis (p-hydroxyphenyl) methane, 1,2-bis (p-hydroxyphenyl) ethane, bisphenol A, bisphenol C, 2,5-naphthalenediol,
Aromatic glycols exemplified by glycols obtained by adding ethylene oxide to these glycols, and the like can be given.

Among the above glycols, ethylene glycol, 1,3-propylene glycol, 1,
It is preferable to use 4-butylene glycol and 1,4-cyclohexanedimethanol as main components.

As polyhydric alcohols other than these glycols, trimethylolmethane, trimethylolethane,
Trimethylolpropane, pentaerythritol, glycerol, hexanetriol and the like.

Examples of the hydroxycarboxylic acid include lactic acid, citric acid, malic acid, tartaric acid, hydroxyacetic acid, 3-hydroxybutyric acid, p-hydroxybenzoic acid, p- (2-hydroxyethoxy) benzoic acid, and 4-hydroxycyclohexanecarboxylic acid. Or an ester-forming derivative thereof.

Examples of the cyclic ester include ε-caprolactone, β-propiolactone, β-methyl-β-propiolactone, δ-valerolactone, glycolide, lactide and the like.

Examples of the ester-forming derivatives of polycarboxylic acids and hydroxycarboxylic acids include these alkyl esters, acid chlorides and acid anhydrides.

The polyester used in the present invention is preferably a polyester whose main acid component is terephthalic acid or its ester-forming derivative or naphthalenedicarboxylic acid or its ester-forming derivative, and whose main glycol component is an alkylene glycol.

The polyester in which the main acid component is terephthalic acid or an ester-forming derivative thereof is a polyester containing terephthalic acid or an ester-forming derivative thereof in a total amount of 70 mol% or more based on all the acid components. It is preferably a polyester containing more than 80 mol%, more preferably a polyester containing more than 90 mol%. Similarly, the polyester in which the main acid component is naphthalenedicarboxylic acid or an ester-forming derivative thereof is preferably a polyester containing a total of 70 mol% or more of naphthalenedicarboxylic acid or an ester-forming derivative thereof, and more preferably 80% or more. It is a polyester containing at least 90 mol%, more preferably a polyester containing at least 90 mol%.

The polyester in which the main glycol component is an alkylene glycol is preferably a polyester containing 70 mol% or more of alkylene glycol in total with respect to all glycol components, more preferably a polyester containing 80 mol% or more. And more preferably a polyester containing 90 mol% or more. The alkylene glycol referred to herein may have a substituent or an alicyclic structure in the molecular chain.

The naphthalenedicarboxylic acid or ester-forming derivative thereof used in the present invention includes 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, and 1,5-naphthalenedicarboxylic acid exemplified as the above-mentioned dicarboxylic acids. , 2,6-naphthalenedicarboxylic acid,
2,7-Naphthalenedicarboxylic acid or their ester-forming derivatives are preferred.

Examples of the alkylene glycol used in the present invention include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol and the above-mentioned glycols.
1,3-butylene glycol, 2,3-butylene glycol, 1,4-butylene glycol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,2-cyclohexanediol, 1,3-
Cyclohexanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-
Cyclohexane dimethanol, 1,4-cyclohexane dimethanol, 1,4-cyclohexane diethanol,
The use of 1,10-decamethylene glycol, 1,12-dodecanediol or the like is preferred. Two or more of these may be used simultaneously.

The polyester of the present invention may contain a known phosphorus compound as a copolymer component. As the phosphorus compound, a bifunctional phosphorus compound is preferable, for example, (2-carboxylethyl) methylphosphinic acid,
(2-carboxylethyl) phenylphosphinic acid,
9,10-dihydro-10-oxa- (2,3-carboxypropyl) -10-phosphaphenanthrene-10
-Oxide and the like. By including these phosphorus compounds as copolymer components, it is possible to improve the flame retardancy and the like of the obtained polyester.

As the constituent components of the polyester of the present invention,
In a preferred embodiment, a polycarboxylic acid having a sulfonate alkali metal base is used as a copolymer component in order to improve dyeability when polyester is used as a fiber.

The metal sulfonate group-containing compound used as the copolymerization monomer is not particularly limited, but may be 5-sodium sulfoisophthalic acid, 2-sodium sulfoterephthalic acid, 5-lithium sulfoisophthalic acid, or 2-lithium sulfoisophthalic acid. Examples include terephthalic acid, 5-potassium sulfoisophthalic acid, 2-potassium sulfoterephthalic acid, and lower alkyl ester derivatives thereof. In the present invention, use of 5-sodium sulfoisophthalic acid or an ester-forming derivative thereof is particularly preferred.

The copolymerization amount of the metal sulfonate group-containing compound is 0.3 to 1 with respect to the acid component constituting the polyester.
0.0 mol% is preferable, and more preferably 0.80%
5.0 mol%. If the copolymerization amount is too small, the dyeability of the basic dye is inferior. If the copolymerization amount is too large, not only the spinning properties are poor, but also the fiber does not have sufficient strength due to the thickening phenomenon. Further, when 2.0 mol% or more of the metal sulfonate group-containing compound is copolymerized, it is possible to impart normal pressure dyeability to the obtained modified polyester fiber. It is possible to appropriately reduce the amount of the metal sulfonate group-containing compound by selecting an appropriate dye for facilitating dyeing. Examples of the easily dyeable monomer include, but are not particularly limited to, long-chain glycol compounds represented by polyethylene glycol and polytetramethylene glycol, and aliphatic dicarboxylic acids represented by adipic acid, sebacic acid, and azelaic acid.

The polyester produced using the polyester polymerization catalyst of the present invention includes polyethylene terephthalate, polybutylene terephthalate, polypropylene terephthalate, poly (1,4-cyclohexanedimethylene terephthalate), polyethylene naphthalate, polybutylene naphthalate, Polypropylene naphthalate and copolymers thereof can be exemplified as preferred polymers, and particularly preferred polymers are polyethylene terephthalate and copolymers thereof.

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

The polyester of the present invention may contain organic, inorganic, and organometallic toners, a fluorescent whitening agent, and the like. Coloration such as yellowishness can be suppressed to a more excellent level. In addition, any other polymer, antistatic agent, antifoaming agent, dyeing improver, dye, pigment, matting agent, optical brightener, stabilizer, antioxidant,
Other additives may be contained. As the antioxidant, an aromatic amine-based, phenol-based, etc. antioxidant can be used, and as the stabilizer, a phosphoric acid-based or phosphoric acid ester-based stabilizer, a sulfur-based, amine-based stabilizer, etc. Can be used.

[0080]

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.

[Evaluation Method] 1) Intrinsic Viscosity (IV) Polyester was dissolved in a mixed solvent of phenol / 1,1,2,2-tetrachloroethane in a 6/4 (weight ratio) mixed solvent, and the temperature was 30 ° C. It was measured.

2) Thermal stability parameter (TS) Melt polymerized IV was about 0.65 dl / g (before melt test;
[IV] 1 g of PET resin chip of _i ) is about 14 m in inner diameter
m, and vacuum-dried at 130 ° C. for 12 hours. Then, the glass test tube was connected to a vacuum line, and after repeating depressurization and nitrogen filling at least 5 times, nitrogen was sealed to 100 Torr and sealed. did. After the test tube was immersed in a salt bath at 300 ° C. and maintained in a molten state for 2 hours, a sample was taken out, freeze-pulverized, dried under vacuum, and measured for IV (after the melting test; [IV] _f ). From this [IV] _f ,
TS was calculated using the following formula. The formula was reported previously (Kamiyama et al .: The Society of Rubber Industry, Japan, Vol. 63, No. 8, p. 497, 1990)
Year).

TS = 0. 245 ｛[IV] _f ^-1.47 −
[IV] _i ^-1.47 ｝ 3) Color delta b value parameter (Δb) When a predetermined stirring torque was reached in the PET melt polymerization, nitrogen was introduced into the autoclave, the pressure was returned to normal pressure, and the polycondensation reaction was stopped. After that, the polymer is discharged into a cold water in the form of strands under a slight pressure to be rapidly cooled, then held in the cold water for about 20 seconds, and then cut to a length of about 3 mm and a diameter of about 2 mm.
Was obtained in a cylindrical shape. The resin chip thus obtained was air-dried on a filter paper at room temperature for about 24 hours, and then used for color measurement. PET having an IV of about 0.65 dl / g obtained as described above
Model TC-1500MC using resin chip
Using a -88 color difference meter (manufactured by Tokyo Denshoku Co., Ltd.), the b value of the Hunter was measured, and PET was polymerized by using 0.05 mol% of antimony trioxide as an antimony atom with respect to the acid component of PET. Was determined by subtracting the b-value.

4) Thermal Stability of Film (i) Film Formation The PET resin chips obtained by melt polymerization in each of the following Examples and Comparative Examples were vacuum dried at 135 ° C. for 6 hours. Then, it was supplied to an extruder, melted and extruded into a sheet at 280 ° C., quenched and solidified on a metal roll maintained at a surface temperature of 20 ° C., and a cast film having a thickness of 1400 μm was obtained.

Next, this cast film was heated to 100 ° C. by a heated roll group and an infrared heater, and then stretched 3.5 times in the longitudinal direction by a roll group having a peripheral speed difference to obtain a uniaxially oriented PET film. Was. Subsequently, the film was stretched 4.0 times in the width direction at 120 ° C. with a tenter, and the film was heated with an infrared heater at 260 ° C. for 0.5 second with the film width fixed, and further 3% at 200 ° C. for 23 seconds. To obtain a biaxially oriented PET film having a thickness of 100 μm.

(Ii) Formation of Film from Collected Pellets The PET film obtained by the method described in (i) above is cut into strips, dried in vacuum, put into an extruder, and melted at a temperature of 280 ° C. After extruding the resin from a nozzle having a diameter of 5 mm, the resin was cooled and cut with water to obtain a recovered pellet.

The PET resin chips obtained by melt polymerization and the above-mentioned recovered pellets were mixed at a weight ratio of 50:50,
Vacuum dried at 35 ° C. for 6 hours. Then, it is supplied to an extruder, melt-extruded into a sheet at 280 ° C., quenched and solidified on a metal roll maintained at a surface temperature of 20 ° C.
A 0 μm cast film was obtained.

Next, the cast film was heated to 100 ° C. by a heated roll group and an infrared heater, and then stretched 3.5 times in the longitudinal direction by a roll group having a peripheral speed difference to obtain a uniaxially oriented PET film. Was. Then, in the tenter,
Stretched 4.0 times in the width direction at 120 ° C, thickness 100 μm
Was obtained.

(Iii) Evaluation of Thermal Stability of Film The appearance of the obtained film was visually observed, and the degree of coloring of the film was evaluated as being better with less coloring.

5) Evaluation of Film Coloring The appearance of the film obtained by the method described in 4) (i) above was visually observed to evaluate the degree of coloring. The evaluation results indicated that those with little coloring were good.

[Synthesis Example of Polyester] (Example 1) A mixture of bis (2-hydroxyethyl) terephthalate and an oligomer produced from high-purity terephthalic acid and ethylene glycol by a conventional method using a 15-L stainless steel autoclave equipped with a stirrer. On the other hand, a 10 g / l ethylene glycol solution of aluminum acetylacetonate was used as a polycondensation catalyst in an amount of 0.02 as an aluminum atom to the acid component in the polyester.
mol% and 10 g / l of ethylene glycol solution of dimethyl phenylphosphonate with respect to the acid component 0.03 mol% of dimethyl phenylphosphonate and 50 g / l of lithium acetate dihydrate with respect to the acid component Then, 0.01 mol% as lithium atom was added, and the mixture was stirred at 245 ° C. for 10 minutes under a nitrogen atmosphere at normal pressure. Then, over 50 minutes, the temperature of the reaction system was gradually lowered while the temperature was raised to 275 ° C., and the pressure was reduced to 13.3 Pa (0.1 Torr).
The polycondensation reaction was further performed at 275 ° C. and 13.3 Pa as r).

The polyethylene terephthalate has an IV of 0.
Polymerization time required to reach 65 dl / g (AP)
Was 130 minutes, and the polycondensation catalyst had a practical polymerization activity.

A polyethylene terephthalate having an IV of 0.65 dl / g obtained by the above polycondensation was formed into a chip having a length of about 3 mm and a diameter of about 2 mm according to a conventional method. The color b value of this PET resin chip is 5.1, and the b value is 3.0 as described in Reference Example for a PET resin chip polymerized with antimony trioxide as a catalyst.
Therefore, Δb = 2.1.

Further, a melting test was carried out using this PET resin chip to determine a thermal stability parameter (TS). T
S was 0.22, and the thermal stability was good.

A film was formed using PET resin chips obtained by melt polymerization. No coloring was observed in the film, and the result of the film coloring evaluation was good. Subsequently, a recovered pellet was formed, and a film was formed from the recovered pellet. As for the evaluation result of the thermal stability of the film, no coloring was recognized in the film, and the result of the evaluation of the thermal stability of the film was good.

Comparative Example 1 As a catalyst, a 10 g / l solution of aluminum acetylacetonate in ethylene glycol was used in an amount of 0.015 mol% as aluminum atoms with respect to the acid component in the polyester and 50 g / l of lithium acetate dihydrate. The same operation as in Example 1 was performed except that the ethylene glycol solution was added as a lithium atom to the acid component at 0.06 mol%.

The AP was 107 minutes, but the color b value of the PET resin chip was 7.9, so Δb = 4.
9, which was yellow.

A film was formed using this PET resin chip. The film was colored, and the result of the film coloring evaluation was not satisfactory.

(Reference Example) The same operation as in Example 1 was carried out except that antimony trioxide was used as a catalyst so that the addition amount was 0.05 mol% as antimony atom with respect to an acid component in PET. Was.

As antimony trioxide, commercially available Ant
imony (III) oxide (ALDRICH C
(HEMICAL, purity 99.999%) was used. As the antimony trioxide, a solution was used which was dissolved in ethylene glycol by stirring at 150 ° C. for about 1 hour so that the concentration became about 10 g / l. AP was 110 minutes, TS was 0.21, color b value was 3.0 (Δb = 0), and these physical properties were excellent.

As is clear from the above Examples and Comparative Examples, the PET resin having the thermal stability parameter and the color delta b value parameter within the scope of the present invention was excellent in the thermal stability of the film. It is excellent in film quality, and the one obtained by reusing the waste film is also excellent in quality and excellent in color tone of the film.

On the other hand, what is out of the claims of the present invention is:
Thermal stability of the film, one or both of the color tone is inferior, the quality of the film is low, the problem that the reuse of the scrap film can only obtain a low-quality film,
The film suffers from one or both of the problems of coloring.

[Industrial Application Field] The polyester polymerization catalyst and the method for producing a polyester of the present invention can be used for producing a polyester polymer. The polyester of the present invention can be used in a wide variety of applications such as fibers for clothing and industrial materials, films and sheets for packaging and magnetic tape, bottles as hollow molded articles, casings for electric and electronic parts, and other engineering plastic molded articles. Can be used in various fields.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Shoichi Katamai 2-1-1 Katata, Otsu-shi, Shiga F-term in Toyobo Co., Ltd. Research Laboratory 4J029 AA03 AB04 AD01 BA03 BA04 BA05 BB10A BD02 BD03A CA02 CB05 CB06 CC05 EA01 EG07 EG09 FC05 FC08 HA01 HB01 JA011 JA061 JA091 JA121 JA201 JA261 JB131 JB171 JC561 JC751 JF011 JF021 JF111 JF221 JF571 KC02

Claims (13)

[Claims] 1. A polyester polymerization catalyst comprising at least one selected from the group consisting of aluminum and its compounds as a first metal-containing component, and having an activity parameter (A
P) satisfies the following formula (1), and the thermal stability parameter (TS) of the polyethylene terephthalate polymerized using the catalyst is represented by the following formula (2), and the color delta b value parameter (Δb) is represented by the following formula (3) ), Respectively. (1) AP (min) <2T (min) (In the above formula, the activity parameter AP is 0 at 275 ° C. and a reduced pressure of 13.3 Pa (0.1 Torr) using a predetermined amount of catalyst. The time (min) required to polymerize .65 dl / g of polyethylene terephthalate is represented by T. AP represents the case where antimony trioxide is used as a catalyst, where antimony trioxide is an acid component in the produced polyethylene terephthalate. (2) TS <0.30 (in the above formula, TS is polyethylene terephthalate (PE) having a melt-polymerized intrinsic viscosity (IV) of about 0.65 dl / g.
T) 1 g of a resin chip was placed in a glass test tube, dried at 130 ° C. for 12 hours under vacuum,
It is calculated | required using the following formula from IV after 2 degreeC and maintaining in a molten state for 2 hours. TS = 0.245 ｛[IV] _f ^-1.47- [IV] _i
^-1.47 ｝ [IV] _i and [IV] _f indicate the IV (dl / g) before and after the melting test, respectively. (3) Δb <4.0 (in the above formula, Δb is a value obtained by using a colorimeter using a polyethylene terephthalate (PET) resin chip having an intrinsic viscosity of about 0.65 dl / g melt-polymerized using a predetermined catalyst. The value obtained by subtracting the b value when antimony trioxide is used as the catalyst from the b value of the hunter measured by the method described above, where antimony trioxide is 0.05 mol as an antimony atom with respect to the acid component in the produced polyethylene terephthalate. %
Added. ) 2. The polyester polymerization catalyst according to claim 1, wherein an alkali metal, an alkaline earth metal or a compound thereof is not added. 3. The polyester polymerization catalyst according to claim 1, wherein at least one kind of a second metal-containing component selected from the group consisting of an alkali metal, an alkaline earth metal and a compound thereof is co-present. 4. The polyester polymerization catalyst according to claim 3, wherein the second metal-containing component is an alkali metal or a compound thereof. 5. The polyester polymerization catalyst according to claim 4, wherein the alkali metal is at least one selected from Li, Na, and K. 6. The polyester polymerization according to claim 3, wherein an addition amount M (mol%) of the second metal-containing component with respect to all carboxylic acid components constituting the polyester satisfies the formula (4). catalyst. (4) M ≦ 0.05 7. The polyester polymerization catalyst according to claim 1, further comprising a cobalt compound. 8. The polyester polymerization catalyst according to claim 1, wherein at least one of phosphorus compounds represented by the following general formulas (Chem. 1) and (Chem. 2) coexists. . Embedded image Ph—P (＝ O) (OR ¹ ) (OR ² ) (wherein R ¹ and R ² each independently represent hydrogen, an alkyl group having 1 to 50 carbon atoms or an aryl group. Me—P (＝ O) (OR ³ ) (OR ⁴ ) (wherein R ³ and R ⁴ are each independently hydrogen, an alkyl group having 1 to 50 carbon atoms, Represents an aryl group.) 9. The polyester polymerization catalyst according to claim 1, further comprising at least one of an antimony compound and a germanium compound. 10. The polyester polymerization catalyst according to claim 9, wherein the amount of the antimony compound added is 50 ppm or less as antimony atoms based on the polyester. 11. The addition amount of the germanium compound is as follows:
20pp for polyester as germanium atom
11. An amount not more than m.
The polyester polymerization catalyst according to any one of the above. 12. A polyester produced using the polyester polymerization catalyst according to claim 1. 13. A method for producing a polyester, comprising using the polyester polymerization catalyst according to any one of claims 1 to 11.