JP7363232B2 - Method for producing polyester composition with excellent hygroscopicity - Google Patents

Description

The present invention relates to a manufacturing method that can easily provide a polyester composition used for fibers that has excellent hygroscopicity and good resistance to oxidative decomposition.

Polyester fibers are used in a wide range of applications because they are inexpensive and have excellent mechanical properties and dry feel. However, due to its poor hygroscopicity, it has problems that need to be solved from the viewpoint of wearing comfort, such as a feeling of stuffiness during high humidity in the summer and generation of static electricity during low humidity in the winter.

Methods for imparting hygroscopic properties to polyester fibers to improve the above-mentioned drawbacks include copolymerization of hydrophilic compounds to polyester, addition of hydrophilic compounds, etc. Polyethylene glycol is an example of a hydrophilic compound. It will be done.

Furthermore, when considering the application to clothing, the essential fiber properties include suppression of yellowing after washing with water and suppression of oxidative heat generation, so it is necessary to include additives and the like. Additives are usually added to the polymer after polymerization by melt-kneading, but since the hygroscopic polyesters mentioned above easily absorb water, a drying process is essential. had to be kept low. Another approach is to strengthen deaeration during kneading, and for example, various kneading methods have been proposed that involve deaeration through a plurality of vent holes.

For example, Patent Document 1 proposes a method of kneading and degassing α-methylstyrene resin containing 1% by weight or more of volatile matter using an extruder provided with a plurality of vent holes.

In addition, Patent Document 2 proposes a kneading method in which particles are added to polyester as a slurry of water or an organic medium and then kneaded to obtain a polyester composition with an excellent dispersion state. Kneading is disclosed.

Japanese Patent Application Publication No. 7-300508 Japanese Patent Application Publication No. 2000-273163

However, the method described in Patent Document 1 removes volatile components such as unreacted monomers and solvents from the α-methylstyrene resin, and could not be immediately applied to hygroscopic polyester. In particular, there is no mention of suppressing yellowing and oxidative heat generation in hygroscopic polyester after washing with water.

Furthermore, the method described in Patent Document 2 is a method that pursues the uniformity and dispersibility of inorganic/organic particles in a polymer, and does not disclose anything about suppressing yellowing and suppressing oxidative heat generation after washing with water in hygroscopic polyester. It has not been.

The purpose of the present invention is to solve the problems of the prior art described above, and to provide a hygroscopic polyester composition that is more efficient by omitting the drying step, and that can suppress yellowing and oxidative heat generation after washing with water. The purpose of this invention is to provide a method for manufacturing the same.

In order to solve the above problems, the present invention employs the following means.

A step of adding polyester having a moisture content of 1.0 to 5.0% by weight, which will be a raw material for a polyester composition, from the most upstream barrel using a kneader having four or more barrels and a discharge die, and an antioxidant. and a step of deaerating gas containing water vapor from two or more vent holes while melting and kneading in the kneading machine, and the vent holes are used to remove polyester from a barrel having four or more holes. A method for producing a polyester composition, wherein vent holes are installed in two or more barrels of the remaining barrels excluding the most upstream barrel to be added.

A polyester composition that has high hygroscopicity and can suppress yellowing and oxidative heat generation after water washing treatment (JIS L0217-1995) can be efficiently obtained by omitting the drying step and using a high water content polyester. .

1 is a schematic diagram of an example of a kneading machine used in the method for producing a polyester composition of the present invention, which is a twin-screw extruder used in Examples and Comparative Examples (however, the position and number of vent holes vary).

The present invention will be explained in detail below.

Hygroscopicity in the present invention refers to the difference between the moisture absorption rate at a temperature of 30°C and humidity of 90% RH, which assumes the temperature and humidity inside clothing after light exercise, and the moisture absorption rate at an outside temperature of 20°C and humidity of 65% RH: It can be expressed as ΔMR. The larger the value of ΔMR, the higher the hygroscopicity, and the more comfortable it is to wear when made into fibers or fabrics.

From the viewpoint of wearing comfort, the ΔMR of the polyester composition is preferably 2.0 to 25.0%, more preferably 4.0 to 25.0% or less, and 8.0 to 25.0% or less. It is more preferably 15.0 to 25.0%, particularly preferably 20.0 to 25.0%, most preferably 20.0 to 25.0%. When ΔMR is less than 2.0%, hygroscopicity is low and the inside of the clothes feels stuffy. When ΔMR is greater than 25.0%, melt moldability deteriorates, and the mechanical strength of the molded product may decrease or fuzz may occur.

The method for producing a polyester composition of the present invention uses a kneader having four or more barrels and a discharge die to mix the polyester with a moisture content of 1.0 to 5.0% by weight, which will be the raw material for the polyester composition, into the uppermost stream. A step of adding the antioxidant from the barrel at the initial charging position, a step of adding the antioxidant, and a step of degassing gas containing water vapor from two or more vent holes while melting and kneading in the kneader. , the vent holes are vent holes arranged in two or more barrels among the constituent barrels excluding the barrel at the most upstream loading position where polyester is added. be.

The method for producing the polyester composition of the present invention uses polyester with a moisture content of 1.0 to 5.0% by weight as the raw material for the polyester composition, and feeds the polyester into a kneading machine without using a drying process. can be done and is very efficient. From the viewpoint that if the moisture content is too high, hydrolysis will occur during kneading and the melt viscosity will decrease, the moisture content is preferably 5.0% by weight or less. The lower limit of the moisture content is preferably 1.0% or more, more preferably 2.5% or more, since the drying step can be omitted and the polyester composition can be efficiently produced.

Conventionally, when kneading polyester, it is customary to dry the polyester raw materials used for kneading in advance to reduce the moisture content in the raw material chips to 500 ppm or less, and then melt-knead them with additives such as antioxidants. be. However, the method for producing the polyester composition of the present invention uses a kneader having two or more vent holes as described below, and also kneads the antioxidant described below to remove the moisture contained in the raw material chips. A very efficient method for producing a polyester composition, which can be used for kneading without prior drying and removal, has been realized.

The method for producing the polyester composition of the present invention involves adding the above-mentioned raw material polyester from the most upstream barrel, adding an antioxidant, and melt-kneading using a kneader having four or more barrels and a discharge die. This is a method for producing a polyester composition while degassing gas containing water vapor from two or more vent holes.

The method for kneading the polyester composition of the present invention includes selecting two or more barrels from among the constituent barrels excluding the barrel at the most upstream loading position where polyester is added, and installing vent holes therein; This is a kneading method in which gas containing water vapor is degassed from this vent hole. From the viewpoint of improving the degassing efficiency of gas containing water vapor, it is preferable to arrange vent holes in two or more barrels. When there is only one vent hole, the efficiency of degassing gas containing water vapor is reduced, the added antioxidant is deactivated, and the retention stability of the obtained polyester composition is reduced.

For example, in the case of a kneader having eight barrels C1 to C8 as shown in FIG. 1, C1 is the barrel at the most upstream loading position. At this time, it is preferable that two or more barrels from C2 to C8, excluding the barrel at the loading position, have vent holes. If there are two vent holes, the first vent hole is located in the barrel next to the charging barrel: C2, because deaeration is performed immediately after the polymer melts, and the hydrolysis reaction that causes strength reduction can be suppressed. It is preferable to place Furthermore, the second point is the discharge die because it removes decomposed gas and residual steam generated during kneading with antioxidant, suppresses bleed-out during drying of the obtained polymer, and suppresses hydrolysis reaction. It is preferable to arrange the vent hole in the barrel next to C8, that is, the last barrel: C8.

When there are three vent holes, in addition to the two barrels mentioned above, it is preferable to select one of the barrels C4 to C6 in the middle and arrange the vent holes. By using three barrels, it is possible to remove the decomposition gas and residual steam generated during kneading with the antioxidant, suppressing bleed-out during drying of the resulting polymer, and improving the hydrolysis reaction. can be suppressed.

The method for kneading the polyester composition of the present invention is to degas the gas containing water vapor from the vent hole by connecting it to a vacuum pump and degassing it under reduced pressure, or by not connecting anything to the vent hole. Although there are methods of degassing under normal pressure as an open system, degassing under reduced pressure is preferred from the viewpoint of improving the degassing efficiency and improving the retention stability of the obtained polyester composition.

Preferably, the method for producing a polyester composition of the present invention further includes a step of discharging the polyester composition from a discharging die in the form of a strand, immersing it in water in a tank, and cooling it. Specifically, it is preferable to water-cool the strand immediately after discharge, take it out from the water tank immediately after solidifying the strand, then air-cool the strand, and then cut it into chips using a cutter. By cooling with water immediately after discharge and taking out from the water tank immediately after solidification, sagging of the strand due to water content can be suppressed and the string tension can be maintained, allowing stable chipping with a cutter.

The method for producing the polyester composition of the present invention involves removing water adhering to the air-cooled strands by suction, from the viewpoint of reducing the moisture content of the chips after cutting and suppressing hydrolysis during chip storage. It is preferable to include a step.

The method for producing a polyester composition of the present invention involves adding a number of hygroscopic polyesters, specifically, polyesters comprising an aromatic dicarboxylic acid and/or an ester-forming derivative thereof, a diol and/or an ester-forming derivative thereof, It is useful when adding an antioxidant to a copolyester obtained by copolymerizing 10 to 50% by weight of polyethylene glycol with an average molecular weight of 5,000 to 20,000, and the antioxidant is represented by the following chemical formula (1). It is preferable to add 10.0 to 200.0 mmol/kg of the phenolic antioxidant, and add the phosphorus antioxidant in an amount of 15.0 to 75.0 mmol/kg.

In the above formula, R ₁ , R ₂ , and R ₃ represent any one of a hydrocarbon group, a hydroxyl group, and a hydrogen atom.

In the method for producing a polyester composition of the present invention, the polyester is a polyester comprising a dicarboxylic acid and an ester-forming derivative thereof, and a diol and an ester-forming derivative thereof.

Specific examples of such polyester include polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polycyclohexylene dimethylene terephthalate, polyethylene-2,6-naphthalenedicarboxylate, polyethylene-1,2-bis Examples include (2-chlorophenoxy)ethane-4,4'-dicarboxylate. In the present invention, polybutylene terephthalate is preferred from the viewpoint of excellent crystallinity and excellent cutting properties at the time of discharge after polymerization.

These polyesters contain dicarboxylic acids such as isophthalic acid, naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, cyclohexanedicarboxylic acid, and 5-sulfoisophthalic acid, and their ester-forming derivatives, which are copolymerized as dicarboxylic acid components. It's okay. Preferably, the amount of the copolymerized dicarboxylic acid component in the total dicarboxylic acid component is 20 mol% or less, more preferably 10 mol% or less.

These polyesters also contain diol compounds such as ethylene glycol, propylene glycol, butanediol, tetramethylene glycol, hexamethylene glycol, diethylene glycol, cyclohexanedimethanol, neopentyl glycol, and polypropylene glycol, and their ester-forming derivatives. etc. may be copolymerized. Preferably, butanediol accounts for 80 mol% or more in all diol components. Diol components other than butanediol can also be copolymerized within a range that does not impair the effects of the invention.

In the method for producing a polyester composition of the present invention, the polyester is preferably a polyester copolymerized with polyethylene glycol. Compared to the case where polyethylene glycol is kneaded with polyester, there is no elution of polyethylene glycol during the washing step in the higher processing step, and high hygroscopicity can be maintained, so it is suitably used as processed products such as fibers.

In the method for producing a polyester composition of the present invention, a polyester copolymerized with polyethylene glycol is used as the polyester, and the polyethylene glycol copolymerized with the polyester has a number average molecular weight of 5,000 to 20,000. 10 to 50% by weight is copolymerized. Here, the specific method for measuring the number average molecular weight and copolymerization amount of polyethylene glycol in the copolymerized polyester will be described later, but after hydrolyzing the copolymerized polyester with an alkaline aqueous solution, it is measured by gel permeation chromatography (GPC). can do.

In the method for producing the polyester composition of the present invention, the polyester is preferably a polyester copolymerized with polyethylene glycol, and by setting the polyethylene glycol copolymerized with the polyester to a specific number average molecular weight, the moisture absorption property becomes extremely large and the processability is improved. Becomes good. Specifically, when the number average molecular weight of the polyethylene glycol copolymerized with the copolymerized polyester is 5000 or more, the moisture absorption performance becomes extremely high. The reason for this is not clear, but it is thought that when the number average molecular weight is 5000 or more, the polyethylene glycol and polyester in the polyester composition of the present invention form a unique structure, resulting in extremely high hygroscopicity. ing. The number average molecular weight of polyethylene glycol is more preferably 5,500 or more, and even more preferably 6,000 or more.

In the method for producing a polyester composition of the present invention, the polyester is preferably a polyester copolymerized with polyethylene glycol, but if the number average molecular weight of the polyethylene glycol copolymerized with the polyester exceeds 20,000, the reactivity with polyethylene terephthalate decreases. In some cases, the dischargeability during polymerization is poor, and the polyethylene glycol dissolves in hot water. The number average molecular weight of the polyethylene glycol copolymerized with the polyester is more preferably 10,000 or less from the viewpoint of moldability, particularly filamentability.

The number average molecular weight of polyethylene glycol in the polyester composition obtained by the production method of the present invention can be calculated by the following procedure. Approximately 0.05 g of copolymerized polyester is collected in a sealable vial, 1 mL of 28% by weight ammonia water is added, and the sample is dissolved by heating at 120° C. for 5 hours. After cooling, 1 ml of purified water and 1.5 ml of 6M hydrochloric acid were added, and the volume was adjusted to 5 ml with purified water. After centrifugation, it is filtered through a 0.45 μm filter, and the number average molecular weight of the one-end-capped polyalkylene oxide compound contained in the filtrate is measured by gel permeation chromatography (GPC). Note that the number average molecular weight of polyethylene glycol, which is a copolymerization component in the present invention, refers to a value determined by GPC in terms of standard polyethylene glycol.

In the method for producing a polyester composition of the present invention, the polyester is preferably a polyester copolymerized with polyethylene glycol, and the amount of polyethylene glycol copolymerized with the polyester is 10 to 50% by weight. When the copolymerized amount of polyethylene glycol is less than 10% by weight, the resulting copolymerized polyester has low hygroscopicity, and has a hygroscopicity comparable to that of polyester that is not copolymerized with polyethylene glycol, resulting in a feeling of stuffiness inside the clothes. From the viewpoint of being able to obtain high hygroscopicity, the copolymerization amount of polyethylene glycol is preferably 10% by weight or more, more preferably 20% by weight or more, even more preferably 30% by weight or more, and particularly preferably 40% by weight or more. . Further, from the viewpoint of heat resistance, melt moldability, for example, spinnability, the amount of polyethylene glycol added must be 50% by weight or less. If it exceeds 50% by weight, the resulting copolyester may not be able to withstand use in a high temperature range, or the mechanical strength of the molded product may decrease.

The copolymerized amount of polyethylene glycol in the polyester composition obtained by the production method of the present invention can be calculated by the following procedure. Approximately 0.05 g of the copolymerized polyester was collected into a measurement tube of a nuclear magnetic resonance apparatus (NMR), and 1 g of deuterated 1,1,1,3,3,3-hexafluoro-2-isopropanol (HFIP) was added. dissolve. By performing 1H-NMR measurement on this solution, the amount of copolymerized polyethylene glycol copolymerized into the polyester composition can be calculated.

In the method for producing the polyester composition of the present invention, the method for producing the copolymerized polyester used is not particularly limited, and it can be produced by known polycondensation methods, ring-opening polymerization methods, etc., and batch polymerization and continuous polymerization. Although either transesterification reaction or direct polymerization can be applied, continuous polymerization is preferable because it can reduce the amount of carboxyl terminal groups, and direct polymerization is preferable from the viewpoint of cost. Polymerization is preferred. The timing of addition of polyethylene glycol as a copolymerization component is, for example, before the esterification reaction or transesterification reaction, from the time when the esterification reaction or transesterification reaction is substantially completed until the polycondensation reaction is started, or after the polycondensation reaction is started. It may be added at any stage, such as after substantially completion.

In the method for producing the polyester composition of the present invention, as a method for producing the copolymerized polyester used, an esterification reaction may be performed using an aromatic dicarboxylic acid and a diol containing 50 mol% or more of 1,4-butanediol. preferable.

Examples of aromatic dicarboxylic acids include isophthalic acid, phthalic acid, 2,6-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, bis(p-carboxyphenyl)methane, anthracene dicarboxylic acid, and 4,4'-diphenyl ether. Examples include dicarboxylic acids, 5-sodium sulfoisophthalic acid, and the like.

From the viewpoint of efficiently producing a polyester composition having excellent heat resistance, mechanical properties, and dyeability, it is preferable that terephthalic acid accounts for 50 mol% or more of the total dicarboxylic acid component, and preferably 90 mol% or more. More preferably, the content is 100 mol%. It is also a preferred embodiment to use isophthalic acid, 2,6-naphthalene dicarboxylic acid, and 5-sodium sulfoisophthalic acid together as the aromatic dicarboxylic acid component other than terephthalic acid.

Examples of diols include aromatic diols, aliphatic diols, alicyclic diols, and heterocyclic diols. Two or more types of these may be used.

Examples of the above aromatic diol include polyoxyethylene-(2.0)-2,2-bis(4-hydroxyphenyl)propane, polyoxyethylene-(2.3)-2,2-bis(4-hydroxyphenyl)propane, and polyoxyethylene-(2.3)-2,2-bis(4-hydroxyphenyl)propane. -hydroxyphenyl)propane, polyoxyethylene-(2.8)-2,2-bis(4-hydroxyphenyl)propane, and polyoxyethylene-(3.0)-2,2-bis(4-hydroxyphenyl) ) Bisphenol A derivatives with ethylene oxide added such as propane, polyoxypropylene-(2.0)-2,2-bis(4-hydroxyphenyl)propane, polyoxypropylene-(2.3)-2,2 -bis(4-hydroxyphenyl)propane, polyoxypropylene-(2.8)-2,2-bis(4-hydroxyphenyl)propane, and polyoxypropylene-(3.0)-2,2-bis( Examples include bisphenol A derivatives to which propylene oxide is added, such as 4-hydroxyphenyl)propane. Two or more types of these may be used.

Examples of the other aliphatic diols mentioned above include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, Examples include 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, neopentyl glycol, diethylene glycol, polypropylene glycol, polytetramethylene glycol, and the like. Two or more types of these may be used.

Examples of the above alicyclic diol include cyclopentanediol, 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, and 1,4-cyclohexanedimethanol. Two or more types of these may be used.

Examples of the above-mentioned heterocyclic diols include isosorbide, isomannide, isoidet, and the like. Two or more types of these may be used.

From the viewpoint of efficiently producing polybutylene terephthalate having excellent crystallization properties, moldability, heat resistance, and mechanical properties, it is preferable that 1,4-butanediol is 50 mol% or more of the total diol component, and 90 It is more preferably mol% or more, and most preferably 100 mol%. It is also a preferred embodiment to use ethylene glycol, 1,3-propanediol and 1,4-cyclohexanedimethanol together as diol components other than 1,4-butanediol.

Next, the polycondensation reaction in the present invention will be explained. In the polycondensation reaction, the polycondensation conditions used in ordinary polyester production, such as a batch method or a continuous method, can be applied as they are.

In the present invention, it is preferable to charge polyethylene glycol into the polymerization tank in advance and transfer the esterified product when the temperature of the polymerization tank is 210° C. or lower. The temperature is preferably 210° C. or lower, more preferably 200° C. or lower, since decomposition of polyethylene glycol can be suppressed and polycondensation reactivity does not decrease.

In the present invention, the temperature of the polymerization tank when transferring the esterified product is synonymous with the temperature of polyethylene glycol that has been charged in the polymerization tank in advance.In the embodiment of the present invention, the spinning pack is replaced during spinning. Pentaerythritol-tetrakis (3-(3,5-di-t-butyl-4-hydroxyphenol) propionate) (manufactured by BASF, Irganox 1010 (IR1010)) is used as an antioxidant during polyester polymerization to reduce the frequency of )) is preferably added. The amount of IR1010 added is preferably in the range of 0.15 to 0.50 parts by weight, more preferably 0.25 to 0.50 parts by weight, and most preferably 0.35 to 0.50 parts by weight. preferable. If the amount added is less than 0.15 parts by weight, the effect of reducing the frequency of replacing the spinning pack during spinning tends not to be exhibited. If the amount added is more than 0.50 parts by weight, the yarn obtained in the presence of nitrogen oxides tends to yellow.

In the method for producing a polyester composition of the present invention, a phenolic antioxidant represented by the following chemical formula (1) is added to the copolyester.

In the above formula, R ₁ , R ₂ , and R ₃ represent any one of a hydrocarbon group, a hydroxyl group, and a hydrogen atom.

In the method for producing a polyester composition of the present invention, specific examples of the phenolic antioxidant to be added include 2,6-di-t-butyl-p-cresol, butylhydroxyanisole, and 2,6-di-t-butyl-p-cresol. t-Butyl-4-ethylphenol, stearyl-β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2,2'-methylenebis(4-methyl-6-t-butylphenol), 2 , 2'-methylenebis(4-ethyl-6-t-butylphenol), 4,4'-butylidenebis(3-methyl-6-t-butylphenol), 3,9-bis{1,1-dimethyl-2-{ β-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl}2,4,8,10-tetraoxaspiro{5,5}undecane, 1,1,3-tris(2 -Methyl-4-hydroxy-5-t-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, bis {3,3'-bis-(4'-hydroxy-3'-t-butylphenyl)butyric acid} glycol ester, tocopherol, pentaerythritol-tetrakis (3-(3,5-di-t-butyl-4 -hydroxyphenol)propionate), bis[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionic acid][ethylenebis(oxyethylene)], 1,3,5-tris[[4- (1,1-dimethylethyl)-3-hydroxy-2,6-dimethylphenyl]methyl]-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, etc. , but not limited to. These phenolic compounds may be used alone or in combination of two or more. Bis[3-(3-t-butyl-4- hydroxy-5-methylphenyl)propionic acid] [ethylenebis(oxyethylene)] (manufactured by BASF, IRGANOX (registered trademark) 245), 3,9-bis{1,1-dimethyl-2-{β-(3- t-Butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl}2,4,8,10-tetraoxaspiro{5,5}undecane (manufactured by ADEKA, ADEKA STAB (registered trademark) AO-80), 1 ,3,5-tris[[4-(1,1-dimethylethyl)-3-hydroxy-2,6-dimethylphenyl]methyl]-1,3,5-triazine-2,4,6(1H,3H , 5H)-trion (manufactured by RIANINLON CORPORATION, THANOX1790) can be suitably employed.

The type of phenolic antioxidant contained in the polyester composition obtained by the production method of the present invention can be identified by the following procedure. After dissolving about 1 g of the polyester composition in 20 mL of HFIP, 40 mL of toluene is added. Then, 60 mL of methanol is added to cause precipitation. The prepared solution is filtered through a 0.45 μm filter, and the solvent is removed from the filtrate using an evaporator to obtain the antioxidant. The obtained antioxidant is placed in an NMR measurement tube, and 1 g of deuterated HFIP is added and dissolved. By performing 1H-NMR measurement on this solution, the structure of the phenolic antioxidant contained in the polyester composition can be determined, and the type can be identified.

In the method for producing the polyester composition of the present invention, it is preferable to add the above-mentioned phenolic antioxidant in an amount of 10.0 to 200.0 mmol/kg. When the amount of the phenolic antioxidant added is less than 10 mmol/kg, the oxidative exothermic resistance of the composite fiber made using the polyester composition obtained by the present invention after water washing treatment (JIS L0217-1995) is decreases, and an oxidative exotherm occurs in less than 90 hours. If the amount of the phenolic antioxidant added is more than 200.0 mmol/kg, the orientation of the fibers made of the polyester composition will be suppressed, resulting in a decrease in fiber strength, resulting in frequent yarn breakage during knitting and weaving processes. , deterioration of quality occurs due to fuzz generation during use. From the viewpoint of oxidative exothermic resistance and fiber strength, the amount of the phenolic antioxidant added is more preferably 70.0 to 200.0 mmol/kg, particularly preferably 120.0 to 200.0 mmol/kg.

The method for producing a polyester composition of the present invention is characterized in that 0.5 to 8.0% by weight of the above phenolic antioxidant is added. If the amount of the phenolic antioxidant added is less than 0.5% by weight, the oxidative exothermic resistance of the composite fiber made from the polyester composition of the present invention after water washing treatment (JIS L0217-1995) is reduced. , oxidative heat generation may occur in less than 90 hours. If the amount of the phenolic antioxidant added is more than 8.0% by weight, the orientation of the fibers made from the polyester composition will be suppressed, resulting in a decrease in fiber strength, resulting in frequent yarn breakage in the knitting and weaving processes. , deterioration in quality may occur due to fuzz formation during use. From the viewpoint of oxidative exothermic resistance and fiber strength, the content of the phenolic antioxidant is more preferably 3.0 to 8.0% by weight, particularly preferably 5.0 to 8.0% by weight.

The oxidation heat resistance test of the composite fiber using the polyester composition of the present invention is carried out according to the following procedure. Samples subjected to water washing treatment (JIS L0217-1995) are stacked up to a depth of 25 mm in a cylindrical container, and a thermocouple is installed in the center. Further, the samples are stacked and filled into a cylindrical container without any gaps. The cylindrical container filled with the sample is placed in a constant temperature dryer set at 150°C, and the time at which oxidation heat generation starts is measured. If the oxidation exothermic start time was 100 hours or more, it was considered acceptable, if it was 90 hours or more, it was good, and if it was less than 90 hours, it was judged to be failed.

The content of the phenolic antioxidant contained in the polyester composition obtained by the production method of the present invention can be calculated by the following procedure. After dissolving about 1 g of copolymerized polyester in 20 mL of HFIP, 40 mL of toluene is added. Thereafter, 60 mL of methanol was added to cause precipitation. The content of the phenolic antioxidant contained in the polyester composition can be calculated by filtering the prepared solution with a 0.45 μm filter, using the resulting filtrate as a measurement sample, and performing HPLC measurement.

In the method for producing a polyester composition of the present invention, it is preferable to further add a phosphorous antioxidant. By adding a phosphorus-based antioxidant, the deactivation of phenol caused by the hypochlorous acid bleach used in water washing treatment (JIS L0217-1995) is suppressed, and the product maintains high oxidation resistance and heat generation even after water washing treatment. Express. The phosphorus-based antioxidant added in the method for producing the polyester composition of the present invention is not particularly limited as long as it is a compound containing the phosphorus element. Specifically, triphenyl phosphite, tris(2,4-t-butylphenyl) phosphite, bis[2,4bis(1,1-dimethylethyl)-6-methylphenyl]ethyl ester phosphorous acid, Bis(2,4-t-butylphenyl)pentaerythritol diphosphite, tetrakis(2,4-di-t-butylphenyl)[1,1biphenyl]-4,4'-diylbisphosphonite, tetra (C12-C15 alkyl)-4,4'-isopropylidene diphenyl diphosphite, 3,9-bis(2,6-t-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3 , 9-diphosphaspiro[5,5-undecane], 1,1'-biphenyl-4,4'-diylbis[bis(2,4-di-t-butylphenyl)phosphonite], and the like. These phosphorus antioxidants may be used alone or in combination of two or more. Among them, tris(2,4-t-butylphenyl)phosphite (manufactured by BASF, IRGAFOS (registered trademark) 168), 3,9-bis(2,6-t-butyl-4-methylphenoxy)-2, 4,8,10-tetraoxa-3,9-diphosphaspiro[5,5undecane] (manufactured by ADEKA, ADEKA STAB (registered trademark) PEP-36), tetra(C12-C15 alkyl)-4,4'-isopropylidenediphenyldi Phosphite (manufactured by Johoku Chemical Co., Ltd., JA-805), 1,1'-biphenyl-4,4'-diylbis [bis(2,4-di-t-butylphenyl) phosphonite] (manufactured by Clariant Chemicals, HOSTANOX P) -EPQ) has good oxidative decomposition resistance after washing with water, and can therefore be suitably employed, and from the viewpoint of suppressing yellowing after washing with water, P-EPQ or PEP-36 is more preferred. PEP-36 is particularly preferred from the viewpoint of being able to suppress bleed-out during chip drying before spinning.

The type of phosphorus antioxidant contained in the polyester composition obtained by the production method of the present invention can be identified by the following procedure. After dissolving about 1 g of copolymerized polyester in 20 mL of HFIP, 40 mL of toluene is added. Then, 60 mL of methanol is added to cause precipitation. The prepared solution is filtered through a 0.45 μm filter, and the solvent is removed from the filtrate using an evaporator to obtain the antioxidant. The obtained antioxidant is placed in an NMR measurement tube, and 1 g of deuterated HFIP is added and dissolved. By performing 1H-NMR measurement on this solution, the structure of the phosphorous antioxidant contained in the polyester composition can be determined, and the type can be identified.

In the method for producing a polyester composition of the present invention, it is preferable to add a phosphorus-based antioxidant in an amount of 15.0 to 75.0 mmol/kg. If the amount of phosphorus added in the phosphorus-based antioxidant is less than 15.0 mmol/kg, yellowing will occur after water washing treatment (JIS L0217-1995), oxidation resistance will decrease, and oxidation will occur in less than 90 hours. Fever may occur. Furthermore, if the amount of phosphorus added in the phosphorus-based antioxidant is more than 75.0 mmol/kg, the orientation of fibers made of the polyester composition is suppressed, resulting in a decrease in fiber strength, resulting in The quality may deteriorate due to frequent breakage or fluffing during use. From the viewpoint of suppressing yellowing after washing with water, oxidation heat resistance, and fiber strength, the amount of phosphorus added in the phosphorus antioxidant is more preferably 35.0 to 65.0 mmol/kg, and 35.0 to 50 mmol/kg. .0 mmol/kg is particularly preferred.

The method for producing a polyester composition of the present invention is characterized in that a phosphorus-based antioxidant is added in an amount of 0.10 to 0.25% by weight as phosphorus. If the amount of phosphorus added in the phosphorus-based antioxidant is less than 0.10% by weight, yellowing will occur after washing with water (JIS L0217-1995), the oxidation heat resistance will decrease, and the product will oxidize in less than 90 hours. Fever may occur. Furthermore, if the amount of phosphorus added in the phosphorus antioxidant is more than 0.25% by weight, the orientation of the fibers made of the polyester composition will be suppressed, resulting in a decrease in fiber strength, resulting in The quality may deteriorate due to frequent breakage or fluffing during use. From the viewpoint of suppressing yellowing after washing with water, oxidative heat resistance, and fiber strength, the amount of phosphorus added in the phosphorus antioxidant is more preferably 0.15 to 0.25% by weight, and 0.15 to 0. .20% by weight is particularly preferred.

The phosphorus content of the phosphorus antioxidant contained in the polyester composition obtained by the production method of the present invention can be calculated by the following procedure. Add 10 mL of sulfuric acid to about 1 g of copolyester and decompose it on a sand bath at 250°C. Add 1.0 mL of perchloric acid and further decompose at 300°C. When the sample becomes colorless and transparent, it is decomposed at 350°C and refluxed with sulfuric acid. After cooling, neutralize with 20% aqueous sodium hydroxide solution. The amount of phosphorus can be calculated by measuring the absorbance of the obtained solution and sample solution at 720 nm using a spectrophotometer.

In the method for producing a polyester composition of the present invention, the phosphorus-based antioxidant to be added is subjected to heat loss evaluation using a thermogravimetric differential thermal analyzer (TG-DTA) at a heating rate of 10°C/min in a nitrogen atmosphere. It is characterized in that when carried out, the 5% weight loss temperature is 170°C or higher. When the 5% weight loss temperature is less than 170° C., the fiber tends to decompose and/or volatilize during kneading or spinning, resulting in a decrease in the oxidative exothermic resistance and yellowing inhibiting effect of the resulting fiber. From the viewpoint of exhibiting oxidation exothermic resistance and yellowing inhibiting effect, the 5% weight loss temperature is preferably 170°C or higher, more preferably 180°C or higher, even more preferably 200°C or higher, and particularly preferably 220°C or higher.

In the method for producing a polyester composition of the present invention, the phosphorus-based antioxidant to be added has a molecular structure containing two or more phosphorus atoms in one molecule. If a phosphorus-based antioxidant having a molecular structure in which one phosphorus atom is used in one molecule is used, it will volatilize during kneading or spinning, resulting in a decrease in the oxidation heat resistance and yellowing inhibiting effect of the resulting fibers. From the viewpoint of exhibiting oxidative exothermic resistance and yellowing inhibiting effect, the phosphorus-based antioxidant preferably has a molecular structure containing two or more phosphorus atoms in one molecule.

In the method for producing a polyester composition of the present invention, the phosphorus antioxidant to be added has a melting point of 80°C or higher. When the melting point of the phosphorus-based antioxidant is less than 80° C., it tends to decompose and/or volatilize during kneading and spinning, resulting in a decrease in the oxidative exothermic resistance and yellowing inhibiting effect of the resulting fibers. From the viewpoint of exhibiting oxidation exothermic resistance and yellowing suppressing effect, the melting point is preferably 80°C or higher, more preferably 100°C or higher, even more preferably 150°C or higher, particularly preferably 180°C or higher, and most preferably 200°C or higher. preferable.

In the method for producing a polyester composition of the present invention, the phosphorous antioxidant to be added has a molecular structure represented by the following chemical formula (2) or chemical formula (3).

In the above formula (2), R represents a hydrocarbon group.

In the above formula (3), R represents a hydrocarbon group.

Examples of the phosphorus antioxidant having the molecular structure represented by the chemical formula (2) include HOSTANOX P-EPQ manufactured by Clariant Chemicals.

Examples of the phosphorus antioxidant having the molecular structure represented by chemical formula (3) include ADEKA STAB PEP-36 manufactured by ADEKA.

The method for producing the polyester composition of the present invention uses a single-screw or twin-screw extruder as a kneader, although other conditions are not particularly limited as long as the requirements specified in the present invention are met. A method of kneading is preferred, and a method of uniformly kneading with a twin-screw extruder is particularly preferred since fibers with excellent mechanical properties can be obtained.

In the embodiment of the present invention, when melt-kneading, each component is introduced using an extruder having two inlets, and the main inlet of the polyester composition is inserted from the main inlet installed at the base of the screw. A method for supplying the component copolyester, a phenolic antioxidant, a phosphorus antioxidant, and other components as necessary, and a method for supplying the main component copolyester and other components of the polyester composition from the main input port, Examples include a method of supplying phenolic antioxidants and phosphorus antioxidants from a sub-inlet installed between the main input port and the tip of the extruder and melt-mixing them, which has excellent mechanical properties and production stability. A preferred method is to supply the copolymerized polyester, the main components of the polyester composition, the phenolic antioxidant, the phosphorus antioxidant, and other components as necessary from the main input port.

Particles may be added to the polyester composition of the present invention for the purpose of reducing friction with contact objects such as various guides and rollers during the molding process, improving process passability, and adjusting the color tone of the product. do not have. As for the type of particles, any conventionally known particles can be used. Specifically, for example, inorganic particles such as silicon dioxide, titanium dioxide, calcium carbonate, barium sulfate, aluminum oxide, and zirconium oxide, and organic polymer particles such as crosslinked polystyrene can be used. Among these particles, titanium dioxide particles are preferred because they have good dispersibility in polymers and are relatively low cost. Titanium dioxide particles are produced by various wet and dry methods, and are added to the reaction system of copolyester after being subjected to pretreatment such as pulverization and classification, if necessary. The particles may be added to the copolymerized polyester reaction system at any stage, but it is preferable to add the particles after substantially completing the esterification reaction or transesterification reaction, since this improves the dispersibility in the polymer. The amount of particles added to the polymer and the particle size vary depending on the application and are not particularly limited, but 0.01 to 10% by weight based on the copolymerized polyester, an average particle size of 0.05 to 5 μm, and a particle size of 4 μm. It is preferable that the number of coarse particles is 1000 pieces/0.4 mg or less, since process passability and color tone are particularly good.

Furthermore, a blue tone adjusting agent, a red tone adjusting agent, or a purple tone adjusting agent may be added as a color tone adjusting agent. The color tone adjusting agent of the present invention refers to a dye used for resins, etc., and specific COLOR INDEX GENERIC NAMEs include blue color tone adjusting agents such as SOLVENT BLUE 104, SOLVENT BLUE 122, and SOLVENT BLUE 45; Red tone adjusters such as SOLVENT RED 111, SOLVENT RED 179, SOLVENT RED 195, SOLVENT RED 135, PIGMENT RED 263, VAT RED 41, DESPERSE VIOLET 26, SO Purple such as LVENT VIOLET 13, SOLVENT VIOLET 37, SOLVENT VIOLET 49, etc. Examples include color tone adjusting agents. Among them, SOLVENT BLUE 104, SOLVENT BLUE 45, SOLVENT RED 179, SOLVENT RED 195, SOLVENT RED 135, which do not contain halogens that tend to cause equipment corrosion, have relatively good heat resistance at high temperatures, and have excellent color development. SOLVENT VIOLET 49 is preferably used. Furthermore, one type or a plurality of types of these color tone adjusting agents can be used depending on the purpose. In particular, it is preferable to use one or more of each of a blue tone adjusting agent and a red tone conditioner, since the color tone can be controlled finely. Furthermore, in this case, it is preferable that the ratio of the blue tone adjusting agent to the total amount of the color tone adjusting agent added is 50% by weight or more, since the color tone of the resulting copolyester will be particularly good. The final amount of the color tone adjusting agent added to the copolymerized polyester is preferably 30 ppm or less in total. If it exceeds 30 ppm, the copolyester may decrease in transparency or develop a dull color. The amount added can be calculated from the structural identification of the color tone adjusting agent using a nuclear magnetic resonance apparatus (NMR) and the ratio of the constituent parts of the color tone adjusting agent.

Other additives include, in addition to the particles and color tone modifiers mentioned above, pigments such as carbon black, surfactants such as alkylbenzenesulfonic acids, conventionally known antioxidants, color inhibitors, light stabilizers, antistatic agents, Compatibilizer, plasticizer, optical brightener, mold release agent, antibacterial agent, nucleating agent, conditioning agent, matting agent, antifoaming agent, preservative, gelling agent, latex, filler, ink, coloring agent, Examples include fragrances. These other additives may be used alone or in combination of two or more.

In the method for producing a polyester composition of the present invention, the melt-kneading temperature when producing the polyester composition is preferably 110 to 360°C, more preferably 210 to 320°C, and more preferably 240 to 280°C. C is particularly preferred.

The polyester composition obtained by the production method of the present invention preferably has an intrinsic viscosity (IV) of 1.50 dL/g or more, preferably 1.55 dL/g when measured at 25°C using o-chlorophenol as a solvent. The above is more preferable, 1.60 dL/g or more is even more preferable, and 1.63 dL/g or more is particularly preferable. Moreover, the upper limit is preferably 2.20 dL/g or less, more preferably 2.15 dL/g or less, and even more preferably 2.10 dL/g or less. By falling within this range, high strength fibers due to a high degree of polymerization can be obtained in the copolymerized polyester.

By using the polyester composition obtained by the production method of the present invention as a component of a composite fiber, it is possible to obtain a composite fiber that exhibits unprecedented hygroscopicity and does not impair the physical properties of the fiber.

Examples are described below as specific embodiments of the composite fiber.

Examples of the fiber form include core-sheath type composite fibers, core-sheath type composite hollow fibers, sea-island type composite fibers, etc., and the polyester composition obtained by the production method of the present invention can be used as a constituent component in any proportion. I can do it. For example, in the case of core-sheath type composite fibers and core-sheath type composite hollow fibers, the composite ratio (weight %) of the polyester composition in the core is preferably core/sheath = 10/90 to 90/10. More preferably 15/85 to 50/50, particularly preferably 20/80 to 40/60. The lower limit of the composite ratio of the core is set for the purpose of imparting sufficient hygroscopicity, and the upper limit of the composite fiber ratio is set for the purpose of preventing deterioration of spinnability and fiber physical properties. In the case of a sea-island composite fiber, the composite ratio (wt%) of the polyester composition in the island portion is preferably island/sea=10/90 to 90/10. More preferably 15/85 to 50/50, particularly preferably 20/80 to 40/60. The lower limit of the composite ratio of the island portion is set for the purpose of imparting sufficient hygroscopicity, and the upper limit of the composite fiber ratio is set for the purpose of preventing deterioration of spinnability and fiber physical properties.

Composite fibers using the polyester composition obtained by the production method of the present invention and other polyesters can be produced by conventionally known methods. show. In the case of the sea-island type composite fiber, the polyester composition (island part) and polyester (sea part) obtained by the production method of the present invention are separately melted and introduced into a spinning pack to form a sea-island composite flow in a spindle device. , is spun out from the discharge hole. After the spun filament yarn is taken off at a predetermined speed, it is once wound up into a package, and the resulting undrawn yarn is stretched using a conventional stretching machine. In addition, the drawing may be carried out continuously without winding up after the spun yarn is taken off, or it may be taken off at a high speed of 4000 m/min or more to obtain the desired fiber performance at once without substantially drawing. You can find a way to get it. Examples of the direct spinning/drawing method include a method in which the spun yarn is taken up at a rate of 1,000 to 5,000 m/min, and then drawn and heat-set at a rate of 3,000 to 6,000 m/min. The filament form of the fiber may be either a filament or a staple, and is appropriately selected depending on the application. The form of the fabric may be appropriately selected depending on the purpose, such as woven fabric, knitted fabric, or non-woven fabric.

Hereinafter, the present invention will be explained in more detail with reference to Examples. In addition, each characteristic value in an Example was calculated|required by the following method.

A. Number Average Molecular Weight of Polyethylene Glycol The molecular weight of polyethylene glycol in the copolymerized polyester was analyzed by gel permeation chromatography (GPC) on the extracted filtrate.
Detector: Waters 2410 differential refractive index detector, sensitivity 128x
Column: Tosoh TSKgelG3000PWXLI
Solvent: 0.1M sodium chloride aqueous solution Flow rate: 0.8mL/min
Injection volume: 200μL
Column temperature: 40℃
Standard substance: polyethylene glycol (manufactured by AML Co., Ltd., Mw106-10100).

B. Extraction of polyethylene glycol in copolymerized polyester The following procedure was performed to extract polyethylene glycol in copolymerized polyester, and the molecular weight of polyethylene glycol was measured by gel permeation chromatography (GPC).

A procedure for extracting polyethylene glycol from copolymerized polyester is shown.

0.05 g of the obtained copolymerized polyester was collected and dissolved in 1 mL of 28% ammonia water by heating at 120°C for 5 hours. After cooling, 1 mL of purified water and 1.5 mL of 6M hydrochloric acid were added, and 5 mL of purified water was added. After constant volumetric centrifugation, it was filtered with a 0.45 μm filter, and the filtrate was used for GPC measurement.

C. Amount of copolymerized polyethylene glycol The amount of copolymerized polyethylene glycol in the copolymerized polyester was analyzed using a nuclear magnetic resonance apparatus (NMR).
Equipment: JEOL Ltd. AL-400
Heavy solvent: deuterated 1,1,1,3,3,3-hexafluoro-2-isopropanol (HFIP)
Number of integrations: 128 times Sample concentration: 0.05 g of measurement sample/1 mL of heavy solvent.

D. Extraction of phenolic antioxidant contained in copolymerized polyester The following procedure was used to extract the phenolic antioxidant contained in copolymerized polyester, and structural analysis of the phenolic antioxidant was performed using a nuclear magnetic resonance apparatus (NMR). It was carried out using

A procedure for extracting phenolic antioxidants from copolymerized polyester is shown.

About 1 g of the obtained copolymerized polyester was dissolved in 20 mL of HFIP, and then 40 mL of toluene was added. Then, 60 mL of methanol was added to cause precipitation. The precipitate was removed with a 0.45 μm filter, and the filtrate was concentrated using an evaporator to obtain a dry product. This dried product was used for 1H-NMR measurement or high performance liquid chromatogram (HPLC) measurement.

E. Structural analysis of the phenol group structural formula and the phenolic antioxidant contained in the copolymerized polyester The phenol group structural formula and structural analysis of the phenolic antioxidant contained in the copolymerized polyester were performed using a nuclear magnetic resonance apparatus (NMR). It was carried out using
Equipment: JEOL Ltd. AL-400
Heavy solvent: deuterated HFIP
Number of integrations: 128 times Sample concentration: 0.05 g of measurement sample/1 mL of heavy solvent.

F. Analysis of phenolic group content (1) Using the fiber obtained in the example as a sample, 1 g of the sample was dissolved in 20 mL of HFIP, and then 40 mL of toluene was added. Then, 60 mL of methanol was added to cause precipitation. The precipitate was removed with a 0.45 μm filter, and the resulting filtrate was used as an HPLC measurement sample. Using this sample, perform HPLC measurement with an HPLC device (SCL-10AVP manufactured by Shimadzu Corporation) under the following conditions, and from the calibration curve of the standard material (1,4-diphenylbenzene) prepared in advance, The amount of phenol groups contained in the sample was quantified, and the phenol group content (mmol/kg) contained in the fibers obtained in the examples was calculated. The measurement was performed five times for each sample, and the average value was taken as the phenol group content.
Column: YMC-Pack ODS-A manufactured by YMC (inner diameter 4.6 mm, length 150 mm, particle diameter 5 nm) Detector: SPD-10AVVP manufactured by Shimadzu Corporation
Mobile phase: methanol (solvent A), water (solvent B), solvent A: solvent B = 88:12
Flow rate: 1.3mL/min Injection volume: 1μL
Column temperature: 40℃
Standard material: 1,4-diphenylbenzene.

(2) Using the fiber obtained in the example as a sample, 0.01 g of the sample was decomposed with 4 mL of 10% hydrochloric acid and methanol at 80°C. After cooling, 1 mL of methanol hydrochloric acid was added, and the precipitate was filtered. HPLC measurements were performed using the filtrate. Standard solutions were IRGANOX® 1010, methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and 3-(3,5-di-tert-butyl-4-hydroxyphenyl). ) Each propionic acid was prepared by dissolving it in a chloroform/acetonitrile solvent, a calibration curve was created, and the phenol group content (mmol/kg) contained in the fiber obtained in the example was calculated.
Column: Inertsil ODS-3 (3 x 150 mm, 5 μm)
Detector: Shimadzu LC-20A
Mobile phase: A. 0.1 vol% formic acid aqueous solution, B. Acetonitrile program: 0.0min → 10.0min B25% → 100%
10.0min→20min B100%
Flow rate: 0.8mL/min Injection volume: 20μL
Column temperature: 50℃
Detection wavelength: PDA 260-280nm.

G. Analysis of content of phenolic antioxidant contained in copolymerized polyester The content of phenolic antioxidant contained in copolymerized polyester was analyzed by HPLC measurement using the precipitate described in Section E. The content of the phenolic antioxidant contained in the sample for HPLC measurement was determined using a calibration curve of a standard substance (1,4-diphenylbenzene) prepared in advance. Note that the measurement was performed five times for each sample, and the average value was used.
Column: YMC-Pack ODS-A manufactured by YMC (inner diameter 4.6 mm, length 150 mm, particle diameter 5 nm) Detector: SPD-10AVVP manufactured by Shimadzu Corporation
Mobile phase: methanol (solvent A), water (solvent B), solvent A: solvent B = 88:12
Flow rate: 1.3mL/min Injection volume: 1μL
Column temperature: 40℃
Standard material: 1,4-diphenylbenzene.

H. Phosphorus element content 1 g of sample was placed in a 100 mL Erlenmeyer flask, 10 mL of sulfuric acid was added, and the sample was decomposed on a sand bath at 250°C. 1.0 mL of perchloric acid was added, and the mixture was further decomposed at 300°C. When the sample became colorless and transparent, it was decomposed at 350°C and continued until the sulfuric acid was sufficiently refluxed. After cooling, the solution was transferred to a 50 mL volumetric flask, and after titration neutralization with a 20% aqueous sodium hydroxide solution, 2 mL of a molybdenum blue coloring solution was added to the neutralized solution. After standing for 15 minutes, the absorbance at 720 nm was measured using a spectrophotometer (U-3310, manufactured by Hitachi High-Tech Science), the amount of phosphorus was determined, and the phosphorus element content (mmol) contained in the fiber obtained in the example was determined. /kg) was calculated.

I. Structural analysis of phosphorus-based antioxidant Using the precipitate obtained by the method described in Section D, structural analysis of the phosphorus-based antioxidant contained in the copolymerized polyester was carried out using a nuclear magnetic resonance apparatus (NMR). did.
Equipment: JEOL Ltd. AL-400
Heavy solvent: deuterated HFIP
Number of integrations: 128 times Sample concentration: 0.05 g of measurement sample/1 mL of heavy solvent.

J. Evaluation of heating loss of phosphorus-based antioxidant Using the precipitate obtained by the method described in Section D, heating loss analysis of the phosphorus-based antioxidant contained in the copolymerized polyester was performed using a thermogravimetric differential thermal analyzer (TG- DTA).
Equipment: TG/DTA6200 manufactured by SEIKO Instruments
Sample: Vacuum drying at 90°C for 24 hours under 0.1 KPa Measurement atmosphere: Under nitrogen Temperature increase rate: Hold at 100°C for 5 minutes, 10°C/min, 100°C → 300°C.

K. Melting point of phosphorus antioxidant Using the precipitate obtained by the method described in section D, melting point analysis of the phosphorus antioxidant contained in the copolymerized polyester was carried out using a differential scanning calorimeter (DSC). .
Equipment: Q-2000 manufactured by TA Instruments
Sample: Vacuum drying at 90°C for 24 hours under 0.1 KPa Temperature increase rate: 16°C/min, 20°C → 150°C.

L. Melting point of phosphorus antioxidant Using the precipitate obtained by the method described in section D, melting point analysis of the phosphorus antioxidant contained in the copolymerized polyester was carried out using a differential scanning calorimeter (DSC). .
Equipment: Q-2000 manufactured by TA Instruments
Sample: Vacuum drying at 90°C for 24 hours under 0.1 KPa Temperature increase rate: 16°C/min, 20°C → 150°C.

M. Melt-kneading viscosity measurement The polyester was vacuum dried at 150°C for 12 hours, and using a Capillograph 1B (manufactured by Toyo Seiki Seisakusho Co., Ltd.) according to JIS 7199:1999, using a capillary die with an inner diameter of 1 mm and a length of 40 mm. Measurement temperature: Measured at a setting of 275°C.

The shear viscosity (η4) at a shear rate of 243.2 sec ^-1 with a preheating time of 4 minutes and the shear viscosity (η20) at a shear rate of 243.2 sec ^-1 with a preheating time of 20 minutes were determined.

N. Fineness: 100 m of fibers obtained in Examples were skeined using an electric measuring machine manufactured by INTEC in an environment of a temperature of 20° C. and a humidity of 65% RH. The weight of the obtained skein was measured, and the fineness (dtex) was calculated using the following formula. The measurement was performed five times for each sample, and the average value was taken as the fineness.

Fineness (dtex) = weight (g) of 100 m of fiber x 100.

O. Strength and Elongation Strength and elongation were calculated using the fibers obtained in the examples as samples according to JIS L1013:2010 (chemical fiber filament yarn testing method) 8.5.1. A tensile test was conducted in an environment of a temperature of 20° C. and a humidity of 65% RH using Tensilon UTM-III-100 manufactured by Orientech Co., Ltd., with an initial sample length of 20 cm and a tensile speed of 20 cm/min. Calculate the strength (cN/dtex) by dividing the stress (cN) at the point showing the maximum load by the fineness (dtex), and use the elongation (L1) at the point showing the maximum load and the initial sample length (L0) to calculate the following: Elongation (%) was calculated using the formula. The measurements were performed 10 times for each sample, and the average values were taken as the strength and elongation. If the strength was 2.0 cN/dtex or more, it was judged to be good, and if it was 2.3 cN/dtex or more, it was judged to be even better.
Elongation (%) = {(L1-L0)/L0}×100.

P. Difference in moisture absorption rate of samples (△MR)
(1) ΔMR of fabric
Using the obtained fiber as a sample, approximately 2 g of tubular knitting was made using a circular knitting machine NCR-BL manufactured by Eiko Sangyo (pot diameter 3 and a half inches (8.9 cm), 27 gauge), and then 1 g/L of sodium carbonate, It was poured into an aqueous solution containing the surfactant Granup US-20 manufactured by Meisei Chemical Industry Co., Ltd., and after scouring at 80° C. for 20 minutes, it was dried in a hot air dryer at 60° C. for 60 minutes to obtain a scoured tube knit. In addition, after the scouring tubular knitting was subjected to hot water treatment under the conditions of a bath ratio of 1:100, a treatment temperature of 130°C, and a treatment time of 60 minutes, it was dried for 60 minutes in a hot air dryer at 60°C. It was knitted.

The moisture absorption rate (%) was calculated according to the moisture content of JIS L1096:2010 (fabric testing method for woven and knitted fabrics) 8.10 using a tube knitted sample after scouring and hot water treatment. First, the tubular knitting was dried with hot air at 60°C for 30 minutes, and then the tubular knitting was left for 24 hours in a constant temperature and humidity machine LHU-123 manufactured by Espec, which was controlled to a temperature of 20°C and humidity of 65% RH. After measuring the weight (W1) of the knitted tube, the tube knitted tube was left to stand for 24 hours in a constant temperature and humidity controlled machine with a temperature of 30° C. and a humidity of 90% RH, and the weight (W2) of the tube knitted tube was measured. Thereafter, the tube knit was dried with hot air at 105° C. for 2 hours, and the weight (W3) of the tube knit after being completely dried was measured. Using the weights W1 and W3 of the tube knitting, calculate the moisture absorption rate MR1 (%) when it is left standing for 24 hours in an atmosphere of temperature 20 ° C. and humidity 65% RH from an absolutely dry state using the following formula, and calculate the weight W2 of the tube knitting. , W3 is used to calculate the moisture absorption rate MR2 (%) when left standing for 24 hours in an atmosphere of temperature 30°C and humidity 90% RH from an absolutely dry state using the following formula, and then calculate the moisture absorption rate difference (△MR ) was calculated. Note that the measurement was performed five times for each sample, and the average value was taken as the moisture absorption rate difference (ΔMR). If ΔMR was 2.0% or more, it was judged to have hygroscopicity, and if it was 3.0% or more, it was judged to be even better.
MR1 (%) = {(W1-W3)/W3}×100
MR2 (%) = {(W2-W3)/W3}×100
Moisture absorption rate difference (ΔMR) (%) = MR2-MR1.

(2) Chip ΔMR
3 g of the obtained chips were freeze-pulverized and used as a measurement sample. After drying with hot air at 60°C for 30 minutes, the sample was left to stand for 24 hours in a constant temperature and humidity machine LHU-123 made by Espec, which was controlled to a temperature of 20°C and humidity of 65% RH, and the weight (W1) of the sample was measured. Thereafter, the sample was left for 24 hours in a constant temperature and humidity chamber controlled to a temperature of 30° C. and a humidity of 90% RH, and the weight (W2) of the tube knit was measured. Thereafter, the sample was dried with hot air at 105° C. for 2 hours, and the weight (W3) of the sample after completely drying was measured. Using the weights W1 and W3 of the sample, calculate the moisture absorption rate MR1 (%) when the sample is left standing for 24 hours in an atmosphere of temperature 20°C and humidity 65% RH from an absolutely dry state using the above formula, and calculate the weight W2 and W3 of the sample. Using the above formula, calculate the moisture absorption rate MR2 (%) when left standing for 24 hours in an atmosphere of temperature 30 ° C and humidity 90% RH from an absolutely dry state, and then calculate the moisture absorption rate difference (ΔMR) using the above formula. did.

Q. Water washing treatment was carried out in accordance with method 103 of JIS L0217:1995 (display symbols and display methods for handling textile products). After adding detergent "Attack" manufactured by Kao Corporation and 2.3 ml/L of bleach "Hiter" manufactured by Kao Corporation and repeating the washing process 10 times, drying was performed at 60℃ for 30 minutes in a tumble dryer. The number of cycles to be performed was one set, and this was repeated 10 times. In the color tone measurement described below, as an evaluation of yellowing inhibition after washing with water, "b* value is less than 10" is A, "b* value is 10 or more and 15 or less" is B, and "b* value is greater than 15". ” was designated as C.

R. Oxidation exothermic start time The samples prepared in step P above and subjected to water washing were stacked up to a depth of 25 mm in a cylindrical container, and a thermocouple was installed in the center. Furthermore, the samples were stacked and filled into a cylindrical container without any gaps. The cylindrical container filled with the sample was placed in a constant temperature dryer set at 150° C. for 200 hours, and the time at which oxidative heat generation started was measured. "Oxidative heat does not occur even after 150 hours" is S, "oxidative heat does not occur even after 100 hours" is A, "oxidative heat starts after 90 hours" is B, "oxidation occurs within less than 90 hours""Start of heat generation" was rated C, and S and A were rated as passing.

S. Nitrogen oxide fastness It was conducted according to JIS L0855:2005 (test method for dye fastness to nitrogen oxides) weak test (1 cycle test). The scouring tubular knit fabric produced in Section P (1) was used as a sample, and after being exposed to nitrogen oxides and post-treated with a buffered urea solution, the degree of discoloration and fading of the sample was determined according to the standards for discoloration and fading specified in JIS L0804:2004. Nitrogen oxide fastness was evaluated by grading using a gray scale.

[Reference example 1]
82.5 kg of high-purity terephthalic acid (manufactured by Mitsui Chemicals) and 35.4 kg of ethylene glycol (manufactured by Nippon Shokubai) were placed in an esterification reaction tank in which 100 kg of bis(hydroxyethyl) terephthalate was charged in advance and maintained at a temperature of 250°C. The slurry was sequentially supplied over a period of 4 hours, and after the completion of the supply, the esterification reaction was continued for another 1 hour, and 101.5 kg of the obtained esterification reaction product was transferred to a polycondensation tank.

To this esterification reaction product, 25.3 g of trimethyl phosphate was added, and 10 minutes later, 20.3 g of cobalt acetate tetrahydrate and 25.3 g of antimony trioxide were added. After a further 5 minutes, an ethylene glycol slurry of titanium oxide particles was added to the polymer in an amount of 0.3% by mass in terms of titanium oxide particles. After another 5 minutes, the reaction system was depressurized to start the reaction. The temperature inside the reactor was gradually raised from 250°C to 290°C, and the pressure was lowered to 40Pa. The time to reach the final temperature and pressure was 60 minutes. When the specified stirring torque is reached, the reaction system is purged with nitrogen and returned to normal pressure to stop the polycondensation reaction, extruded into a strand from the die, cooled in a water bath, and cut to obtain polyethylene terephthalate (PET) pellets. Ta. The intrinsic viscosity of the obtained PET was 0.65.

(Example 1)
After heating 1.0 kg of BDO to 100° C., 250 g of titanium catalyst: tetra-n-butoxy titanate (TBT) (Tokyo Kasei) was mixed to obtain a catalyst solution.

Terephthalic acid (TPA) (Tokyo Kasei Kogyo Co., Ltd.) 45.3 kg as a dicarboxylic acid component, butanediol (BDO) (Tokyo Kasei Kogyo Co., Ltd.) 44.2 kg as a diol component, obtained by the above method as an esterification reaction catalyst. 135 g of the prepared catalyst solution was charged into an ES reaction tank equipped with a rectification column. After starting the esterification reaction under reduced pressure at a temperature of 160°C and a pressure of 93 kPa, the temperature was gradually raised, and finally the esterification reaction was carried out at a temperature of 235°C for 270 minutes.

60.0 kg of polyethylene glycol (PEG) with a number average molecular weight of 8300 g/mol (PEG6000S manufactured by Sanyo Chemical Industries, Ltd.), antioxidant: pentaerythritol-tetrakis (3-(3,5-di-t-butyl-4- 180 g of hydroxyphenol propionate) (manufactured by BASF, IRGANOX1010) was put into a polymerization tank, and when the temperature of the polymerization tank reached 180° C. or higher, the reaction product obtained in the ES reaction tank was transferred. After the temperature of the polymerization tank reached 250°C, 300 g of the catalyst solution obtained by the above method was added as a polycondensation reaction catalyst, and the polycondensation reaction was carried out at a temperature of 250°C and a pressure of 100 Pa to achieve a predetermined stirring torque. At that point, the reaction system was purged with nitrogen to return to normal pressure to stop the polycondensation reaction, extruded into a strand from a die, cooled in a water bath, and cut to obtain pellets of polyethylene glycol copolymerized polybutylene terephthalate. There were no problems with polymerization and discharge. The intrinsic viscosity of the obtained copolymerized polyester was 2.00.

Subsequently, 2,2'-dimethyl-2,2'-(2,4,8,10-tetraoxaspiro[5, 5] undecane-3,9-diyl)dipropane-1,1' diyl-bis[3-(3-t-butyl-4-hydroxy 5-methylphenyl)propanoate] (manufactured by ADEKA, ADEKA STAB AO-80) .0% by weight, 1,1'-biphenyl-4,4'-diylbis[bis(2,4-di-t-butylphenyl)phosphonite] (manufactured by Clariant Chemicals, HOSTANOX P-EPQ) 2.9 weight % and oxidized using a twin-screw extruder with L/D = 45 (L represents screw length, D represents screw diameter) under conditions of cylinder temperature 250 ° C, rotation speed 200 rpm, and discharge rate 30 kg/h. The inhibitor was melt-kneaded. In addition, polyethylene glycol copolymerized polybutylene terephthalate and two types of antioxidants (AO-80, P-EPQ) are transported together with the raw material polyester from the barrel (C1) at the most upstream (priming position) of the twin-screw extruder. Batch addition was performed. The twin-screw extruder used has eight barrels C1 to C8 as shown in Figure 1, but vent holes were installed in two barrels C2 and C8, and degassing was performed under reduced pressure conditions of 10 kPa. Ta.

The polymer properties of the obtained polyester composition were ΔMR of 22.0% and melt viscosity (η4) of 1500 poise after residence at 275° C. for 4 minutes.

The obtained polyester composition was used as an island component, and the polyester obtained in Reference Example 1 was used as a sea component, and after drying each until the moisture content became 300 ppm or less, the island component was 20% by mass and the sea component was 80% by mass. The raw material of 92 dtex-72 f was fed to an extruder-type composite spinning machine at a blending ratio of A drawn yarn was obtained. Thereafter, using a drawing false twisting machine (twisting part: friction disk type, heater part: contact type), the obtained undrawn yarn was drawn and false twisted at a heater temperature of 140 ° C. and a magnification of 1.4 times, A sea-island type composite false twisted yarn of 66 dtex-72 f was obtained. There were no problems such as bleed-out during drying preparation before spinning.

Tables 9 and 12 show the polymer properties, fiber properties, and fabric properties of the obtained copolyester. The fiber strength was 2.5 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 4.0%. The yellowing inhibition after washing with water was rated "A", and the heat of oxidation after washing with water was rated "S", which was good. In addition, the nitrogen oxide fastness test result was grade 4-5.

(Example 2)
Example 1 was carried out in the same manner as in Example 1, except that the amount of AO-80 added during kneading was 7.0% by weight.

There was no problem in polymerization and discharge, and the melt viscosity of the polyester composition after kneading with the antioxidant was η4: 1450 poise and η20: 900 poise. The obtained fiber strength was 2.5 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 4.1%. The yellowing inhibition after washing with water was rated "A", and the heat of oxidation after washing with water was rated "S", which was good. In addition, the nitrogen oxide fastness test result was grade 4-5.

(Example 3)
Example 1 was carried out in the same manner as in Example 1, except that the amount of AO-80 added during kneading was 6.0% by weight.

There was no problem in polymerization and discharge, and the melt viscosity of the polyester composition after kneading with the antioxidant was η4: 1450 poise and η20: 900 poise. The obtained fiber strength was 2.4 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 4.1%. The yellowing inhibition after washing with water was rated "A", and the heat of oxidation after washing with water was rated "S", which was good. In addition, the nitrogen oxide fastness test result was grade 4-5.

(Example 4)
Example 1 was carried out in the same manner as in Example 1, except that the amount of AO-80 added during kneading was 5.0% by weight.

There was no problem in polymerization and discharge, and the melt viscosity of the polyester composition after kneading with the antioxidant was η4: 1200 poise and η20: 750 poise. The obtained fiber strength was 2.4 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 4.0%. The inhibition of yellowing after washing with water was rated "A", and the heat generation due to oxidation after washing with water was rated "A", which was good. In addition, the nitrogen oxide fastness test result was grade 4-5.

(Example 5)
Example 1 was carried out in the same manner as in Example 1, except that the amount of AO-80 added during kneading was 4.0% by weight.

There was no problem in polymerization and discharge, and the melt viscosity of the polyester composition after kneading with the antioxidant was η4: 1100 poise and η20: 600 poise. The obtained fiber strength was 2.6 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 4.0%. The yellowing inhibition after water washing treatment was rated "A", and the oxidation heat generation after water washing treatment was rated "B". In addition, the nitrogen oxide fastness test result was grade 4-5.

(Example 6)
Example 1 was carried out in the same manner as in Example 1, except that the amount of AO-80 added during kneading was 3.0% by weight.

There was no problem in polymerization and discharge, and the melt viscosity of the polyester composition after kneading with the antioxidant was η4: 950 poise and η20: 500 poise. The obtained fiber strength was 2.6 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 3.9%. The yellowing inhibition after water washing treatment was rated "A", and the oxidation heat generation after water washing treatment was rated "B". In addition, the nitrogen oxide fastness test result was grade 4-5.

(Example 7)
Example 1 was carried out in the same manner as in Example 1, except that the amount of AO-80 added during kneading was 2.0% by weight.

There was no problem in polymerization and discharge, and the melt viscosity of the polyester composition after kneading with the antioxidant was η4: 900 poise and η20: 400 poise. The obtained fiber strength was 2.5 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 4.0%. The yellowing inhibition after water washing treatment was rated "A", and the oxidation heat generation after water washing treatment was rated "C". In addition, the nitrogen oxide fastness test result was grade 4-5.

(Example 8)
Example 1 was carried out in the same manner as in Example 1, except that the amount of AO-80 added during kneading was 1.0% by weight.

There was no problem in polymerization and discharge, and the melt viscosity of the polyester composition after kneading with the antioxidant was η4: 850 poise and η20: 350 poise. The obtained fiber strength was 2.5 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 4.2%. The yellowing inhibition after water washing treatment was rated "A", and the oxidation heat generation after water washing treatment was rated "C". In addition, the nitrogen oxide fastness test result was grade 4-5.

(Example 9)
Example 1 was carried out in the same manner as in Example 1, except that the amount of AO-80 added during kneading was 0.5% by weight.

There was no problem in polymerization and discharge, and the melt viscosity of the polyester composition after kneading with the antioxidant was η4: 800 poise and η20: 350 poise. The obtained fiber strength was 2.5 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 4.2%. The yellowing inhibition after water washing treatment was rated "A", and the oxidation heat generation after water washing treatment was rated "C". In addition, the nitrogen oxide fastness test result was grade 4-5.

(Example 10)
Example 3 was carried out in the same manner as in Example 3, except that the amount of P-EPQ added during kneading was 3.6% by weight.

There was no problem in polymerization and discharge, and the melt viscosity of the polyester composition after kneading with the antioxidant was η4: 1400 poise and η20: 900 poise. The obtained fiber strength was 2.3 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 4.0%. The yellowing inhibition after water washing treatment was rated "A", and the oxidation heat generation after water washing treatment was rated "S". In addition, the nitrogen oxide fastness test result was grade 4-5.

(Example 11)
Example 3 was carried out in the same manner as in Example 3, except that the amount of P-EPQ added during kneading was 2.2% by weight.

There was no problem in polymerization and discharge, and the melt viscosity of the polyester composition after kneading with the antioxidant was η4: 1350 poise and η20: 900 poise. The obtained fiber strength was 2.6 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 3.9%. The yellowing inhibition after water washing treatment was rated "A", and the oxidation heat generation after water washing treatment was rated "A". In addition, the nitrogen oxide fastness test result was grade 4-5.

(Example 12)
Example 3 was carried out in the same manner as in Example 3, except that the amount of P-EPQ added during kneading was 1.4% by weight.

There was no problem in polymerization and discharge, and the melt viscosity of the polyester composition after kneading with the antioxidant was η4: 1100 poise and η20: 750 poise. The obtained fiber strength was 2.5 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 4.0%. The yellowing inhibition after water washing treatment was rated "B", and the oxidation heat generation after water washing treatment was rated "B". In addition, the nitrogen oxide fastness test result was grade 4-5.

(Example 13)
In Example 12, the esterification reaction was performed by changing TPA to 54.3 kg, BDO to 53.0 kg, and 162 g of ES catalyst solution, and the polycondensation reaction was performed by changing PEG to 48.0 kg. Except for this, the same procedure as in Example 12 was carried out.

There was no problem in polymerization and discharge, and the melt viscosity of the polyester composition after kneading with the antioxidant was η4: 1200 poise and η20: 900 poise. The obtained fiber strength was 2.6 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 3.1%. The yellowing inhibition after water washing treatment was rated "A", and the oxidation heat generation after water washing treatment was rated "A". In addition, the nitrogen oxide fastness test result was grade 4-5.

(Example 14)
Example 3 was carried out in the same manner as in Example 3, except that the phosphorous antioxidant added during kneading was changed to tris(2,4-t-butylphenyl)phosphite (manufactured by BASF, IRGAFOS168).

There was no problem in polymerization and discharge, and the melt viscosity of the polyester composition after kneading with the antioxidant was η4: 950 poise and η20: 450 poise. Bleed-out derived from the phosphorus antioxidant occurred during chip drying before spinning, and the obtained fiber strength was 2.4 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 4.0%. The yellowing inhibition after water washing treatment was rated "B", and the oxidation heat generation after water washing treatment was rated "A". In addition, the nitrogen oxide fastness test result was grade 4-5.

(Example 15)
In Example 3, the phosphorus antioxidant added during kneading was changed to tetra(C12-C15 alkyl)-4,4'-isopropylidene diphenyl diphosphite (manufactured by Johoku Kagaku Kogyo Co., Ltd., JA-805). The same procedure as in Example 3 was carried out except that the amount added was changed to 2.6% by weight.

There was no problem in polymerization and discharge, and the melt viscosity of the polyester composition after kneading with the antioxidant was η4: 1100 poise and η20: 750 poise. The obtained fiber strength was 2.6 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 4.1%. The yellowing inhibition after water washing treatment was rated "C", and the oxidation heat generation after water washing treatment was rated "A". In addition, the nitrogen oxide fastness test result was grade 4-5.

(Example 16)
In Example 3, the phosphorous antioxidant added during kneading was changed to triphenyl phosphite (JP-360, manufactured by Johoku Kagaku Kogyo Co., Ltd.), and the amount added was changed to 1.4% by weight. It was carried out in the same manner as in Example 3.

There was no problem in polymerization and discharge, and the melt viscosity of the polyester composition after kneading with the antioxidant was η4: 900 poise and η20: 400 poise. Bleed-out derived from the phosphorus antioxidant occurred during chip drying before spinning, and the obtained fiber strength was 2.4 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 4.0%. The yellowing inhibition after water washing treatment was rated "C", and the oxidation heat generation after water washing treatment was rated "B". In addition, the nitrogen oxide fastness test result was grade 4-5.

(Example 17)
In Example 3, the phosphorus antioxidant added during kneading was replaced with 3,9-bis(2,6-t-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro. The same procedure as in Example 3 was carried out except that [5,5 undecane] (ADEKA STAB PEP-36) was used and the amount added was changed to 1.4% by weight.

There was no problem in polymerization and discharge, and the melt viscosity of the polyester composition after kneading with the antioxidant was η4: 950 poise and η20: 400 poise. Bleed-out derived from the phosphorus antioxidant occurred during chip drying before spinning, and the obtained fiber strength was 2.5 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 4.0%. The yellowing inhibition after water washing treatment was rated "A", and the oxidation heat generation after water washing treatment was rated "A". In addition, the nitrogen oxide fastness test result was grade 4-5.

(Example 18)
In Example 3, the phenolic antioxidant added during kneading was bis[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionic acid][ethylenebis(oxyethylene)] (manufactured by BASF, The same procedure as in Example 3 was carried out except that the amount of the phosphorus antioxidant was changed to 4.8% by weight, and the amount of the phosphorus antioxidant was changed to 2.2% by weight.

There was no problem in polymerization and discharge, and the melt viscosity of the polyester composition after kneading with the antioxidant was η4: 1300 poise and η20: 800 poise. The obtained fiber strength was 2.5 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 4.1%. The yellowing inhibition after water washing treatment was rated "A", and the oxidation heat generation after water washing treatment was rated "A". In addition, the nitrogen oxide fastness test result was grade 4-5.

(Example 19)
In Example 3, the phenolic antioxidant added during kneading was 1,3,5-tris[[4-(1,1-dimethylethyl)-3-hydroxy-2,6-dimethylphenyl]methyl]-1 , 3,5-triazine-2,4,6(1H,3H,5H)-trione (manufactured by RIANINLON CORPORATION, THANOX1790), and the amount added was changed to 3.8% by weight, and the amount of phosphorus antioxidant The same procedure as in Example 3 was carried out except that the amount added was changed to 2.2 parts by weight.

There was no problem in polymerization and discharge, and the melt viscosity of the polyester composition after kneading with the antioxidant was η4: 1300 poise and η20: 800 poise. The obtained fiber strength was 2.5 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 4.1%. The yellowing inhibition after water washing treatment was rated "A", and the oxidation heat generation after water washing treatment was rated "B". Further, the nitrogen oxide fastness test result was grade 4-5.

(Example 20)
51.9 kg of high-purity terephthalic acid (manufactured by Mitsui Chemicals, Inc.) and ethylene glycol (manufactured by Nippon Shokubai Co., Ltd.) were placed in an esterification reaction tank in which 100 kg of bis(hydroxyethyl) terephthalate was charged in advance and maintained at a temperature of 250°C. 23.3 kg of slurry was sequentially supplied over 4 hours, and after the supply was completed, the esterification reaction was continued for another 1 hour.

60.0 kg of polyethylene glycol (PEG) with a number average molecular weight of 8300 g/mol (PEG6000S manufactured by Sanyo Chemical Industries, Ltd.), antioxidant: pentaerythritol-tetrakis (3-(3,5-di-t-butyl-4- 180g of hydroxyphenol)propionate (manufactured by BASF, IRGANOX1010) was put into the polymerization tank, and when the temperature of the polymerization tank reached 180°C or higher, 63.9kg of the reactant obtained in the ES reaction tank was added to the polycondensation tank. Transferred. After the temperature of the polymerization tank reached 250° C., 30.0 g of trimethyl phosphate was added as a polycondensation reaction catalyst, and 10 minutes later, 24.0 g of cobalt acetate tetrahydrate and 30.0 g of antimony trioxide were added. After a further 5 minutes, an ethylene glycol slurry of titanium oxide particles was added to the polymer in an amount of 0.3% by mass in terms of titanium oxide particles. After another 5 minutes, the reaction system was depressurized to start the reaction. The temperature inside the reactor was gradually raised from 250°C to 290°C, and the pressure was lowered to 40Pa. The time to reach the final temperature and pressure was 60 minutes. When the specified stirring torque is reached, the reaction system is purged with nitrogen and returned to normal pressure to stop the polycondensation reaction, extruded into a strand from a spinneret, cooled in a water bath, and cut to produce pellets of polyethylene glycol copolymerized polyethylene terephthalate. Obtained. There were many miscuts during polymerization and discharge. The intrinsic viscosity of the obtained copolymerized polyester was 1.15.

In Example 11, kneading and spinning were carried out in the same manner as in Example 11, except that the cylinder temperature during kneading was 280°C.
The melt viscosity of the polyester composition after kneading with the antioxidant was η4: 2000 poise, η20: 1800 poise.

The obtained fiber strength was 3.5 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 4.0%. The inhibition of yellowing after washing with water was rated "A", and the heat generation due to oxidation after washing with water was rated "A", which was good. In addition, the nitrogen oxide fastness test result was grade 4-5.

(Example 21)
In Example 12, the esterification reaction was carried out by changing TPA to 76.9 kg, BDO to 75.1 kg, and 230 g of ES catalyst solution, and PEG to polyethylene glycol (PEG) with a number average molecular weight of 10,000 g/mol ( The same procedure as in Example 12 was carried out except that the polycondensation reaction was carried out using 18.0 kg of PEG10000 (manufactured by Sanyo Chemical Industries, Ltd.).

Thickness and thinness of the discharge gut occurred during polymerization discharge, and the melt viscosity of the polyester composition after kneading the antioxidant was η4: 1500 poise and η20: 1200 poise. The obtained fiber strength was 2.5 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 0.7%. The yellowing inhibition after water washing treatment was rated "A", and the oxidation heat generation after water washing treatment was rated "A". In addition, the nitrogen oxide fastness test result was grade 4-5.

(Example 22)
Example 21 was carried out in the same manner as in Example 21, except that PEG was changed to polyethylene glycol (PEG) (PEG20000 manufactured by Sanyo Chemical Industries, Ltd.) with a number average molecular weight of 20000 g / mol and the polycondensation reaction was carried out. .

Thickness and thinness of the discharge gut occurred during polymerization discharge, and the melt viscosity of the polyester composition after kneading the antioxidant was η4: 1500 poise and η20: 1200 poise. The obtained fiber strength was 2.3 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 0.8%. The yellowing inhibition after water washing treatment was rated "A", and the oxidation heat generation after water washing treatment was rated "A". In addition, the nitrogen oxide fastness test result was grade 4-5.

(Example 23)
Example 11 was carried out in the same manner as in Example 11, except that the antioxidant kneading conditions were that vent holes were installed in three barrels, C2, C4, and C8.

There was no problem in polymerization and discharge, and the melt viscosity of the polyester composition after kneading with the antioxidant was η4: 1400 poise and η20: 950 poise. The obtained fiber strength was 2.4 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 4.1%. The yellowing inhibition after water washing treatment was rated "A", and the oxidation heat generation after water washing treatment was rated "A". In addition, the nitrogen oxide fastness test result was grade 4-5.

(Example 24)
In Example 11, as the antioxidant kneading conditions, two kinds of antioxidants were added from a side feeder installed in a C5 barrel. The same procedure as in Example 11 was carried out except that vent holes were installed in three barrels, C2, C4, and C8, and the vent hole of C4 was an open system.

There was no problem in polymerization and discharge, and the melt viscosity of the polyester composition after kneading with the antioxidant was η4: 1150 poise and η20: 850 poise. The obtained fiber strength was 2.4 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 3.7%. The yellowing inhibition after water washing treatment was rated "A", and the oxidation heat generation after water washing treatment was rated "A". In addition, the nitrogen oxide fastness test result was grade 4-5.

(Example 25)
Example 11 was carried out in the same manner as in Example 11, except that the antioxidant kneading conditions were deaeration in an open system.

There was no problem in polymerization and discharge, and the melt viscosity of the polyester composition after kneading with the antioxidant was η4: 1150 poise and η20: 700 poise. The obtained fiber strength was 2.3 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 3.8%. The yellowing inhibition after water washing treatment was rated "A", and the oxidation heat generation after water washing treatment was rated "A". In addition, the nitrogen oxide fastness test result was grade 4-5.

(Example 26)
Example 11 was carried out in the same manner as in Example 11, except that the antioxidant kneading conditions were a raw material polyester that was vacuum dried (150° C., 2 hours) and had a moisture content of 2.5%.

There was no problem in polymerization and discharge, and the melt viscosity of the polyester composition after kneading with the antioxidant was η4: 1400 poise and η20: 850 poise. The obtained fiber strength was 2.3 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 4.0%. The yellowing inhibition after water washing treatment was rated "A", and the oxidation heat generation after water washing treatment was rated "A". In addition, the nitrogen oxide fastness test result was grade 4-5.

(Example 27)
Example 11 was carried out in the same manner as in Example 11, except that the antioxidant kneading conditions were a raw material polyester that was vacuum dried (150° C., 4 hours) and had a moisture content of 1.0%.

There was no problem in polymerization and discharge, and the melt viscosity of the polyester composition after kneading with the antioxidant was η4: 1400 poise and η20: 900 poise. The obtained fiber strength was 2.4 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 4.0%. The yellowing inhibition after water washing treatment was rated "A", and the oxidation heat generation after water washing treatment was rated "A". In addition, the nitrogen oxide fastness test result was grade 4-5.

(Comparative example 1)
Example 1 was carried out in the same manner as in Example 1, except that the phenolic antioxidant and phosphorus antioxidant were not added during kneading.

There was no problem in polymerization and discharge, and the melt viscosity of the polyester composition after kneading with the antioxidant was η4: 750 poise and η20: 250 poise. The obtained fiber strength was 2.4 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 3.8%. The yellowing inhibition after water washing treatment was rated "A", and the oxidation heat generation after water washing treatment was rated "C". Further, the nitrogen oxide fastness test result was grade 5.

(Comparative example 2)
Example 11 was carried out in the same manner as in Example 11, except that the antioxidant kneading conditions were that a vent hole was installed in one barrel of C8.

There was no problem in polymerization and discharge, and the melt viscosity of the polyester composition after kneading with the antioxidant was η4: 1100 poise and η20: 400 poise. The obtained fiber strength was 2.4 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 4.1%. The yellowing inhibition after water washing treatment was rated "A", and the oxidation heat generation after water washing treatment was rated "A". In addition, the nitrogen oxide fastness test result was grade 4-5.

(Comparative example 3)
Example 11 was carried out in the same manner as in Example 11, except that the antioxidant kneading conditions were a raw material polyester that was vacuum dried (150° C., 12 hours) and had a moisture content of 0.5%.

There was no problem in polymerization and discharge, and the melt viscosity of the polyester composition after kneading with the antioxidant was η4: 1350 poise and η20: 850 poise. The obtained fiber strength was 2.3 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 4.0%. The yellowing inhibition after water washing treatment was rated "A", and the oxidation heat generation after water washing treatment was rated "A". In addition, the nitrogen oxide fastness test result was grade 4-5.

(Comparative example 4)
Example 11 was carried out in the same manner as in Example 11, except that the antioxidant kneading conditions were a raw material polyester that was vacuum dried (150° C., 24 hours) and had a moisture content of 0.05%.

There was no problem in polymerization and discharge, and the melt viscosity of the polyester composition after kneading with the antioxidant was η4: 1400 poise and η20: 900 poise. The obtained fiber strength was 2.4 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 3.8%. The yellowing inhibition after water washing treatment was rated "A", and the oxidation heat generation after water washing treatment was rated "A". In addition, the nitrogen oxide fastness test result was grade 4-5.

(Comparative example 5)
Example 11 was carried out in the same manner as in Example 11, except that water was added as the antioxidant kneading condition and raw polyester was used with a moisture content of 7.0%.

There was no problem in polymerization and discharge, and the melt viscosity of the polyester composition after kneading with the antioxidant was η4: 1000 poise and η20: 600 poise. The obtained fiber strength was 2.4 cN/dtex. The moisture absorption rate difference (ΔMR) after hot water treatment was 4.0%. The yellowing inhibition after water washing treatment was rated "A", and the oxidation heat generation after water washing treatment was rated "A". In addition, the nitrogen oxide fastness test result was grade 4-5.

The chemical structural formulas of the phenolic compounds (phenolic antioxidants) and phosphorus antioxidants used in Examples and Comparative Examples are shown in Tables 3 and 4. Table 5 shows various physical properties of the phosphorus antioxidant used in the present invention.

The method for producing the polyester composition of the present invention is more efficient by omitting the drying step and using a polyester with high water content, and has high hygroscopicity and suppresses yellowing and oxidative heat generation after washing with water. It is possible to provide possible polyester compositions. Due to these characteristics, the polyester composition obtained according to the present invention can be suitably used in applications where comfort and elegance are required. Specifically, it can be used for general clothing, sports clothing, bedding, interior decoration, materials, etc.

1: Main feeder 2: Side feeder 3: Vent (hole)
4: Die 5: Barrel A: Kneader (twin screw extruder)
C1: Most upstream barrel C2 to C8: Other (remaining barrels excluding the most upstream barrel)

Claims (3)

10 to 50% by weight of polyethylene glycol having a number average molecular weight of 5,000 to 20,000 is copolymerized to a polyester consisting of an aromatic dicarboxylic acid and/or its ester-forming derivative and a diol and/or its ester-forming derivative. It is a copolymerized polyester with
To the copolymerized polyester, add 10.0 to 200.0 mmol/kg of a phenolic antioxidant having a structure represented by the following chemical formula (1), and add 15.0 to 75.0 mmol of phosphorus antioxidant as phosphorus amount. /kg is added to a polyester composition, the method comprising:
Using a kneader with four or more barrels and a discharge die,
A step of adding the copolymerized polyester having a moisture content of 1.0 to 5.0% by weight, which is a raw material for the polyester composition, from the most upstream barrel;
adding the antioxidant;
while melting and kneading in the kneader, degassing gas containing water vapor from two or more vent holes,
The polyester composition is characterized in that the vent holes are vent holes installed in two or more barrels among the four or more barrels excluding the most upstream barrel where polyester is added. How things are manufactured.

In the above formula, R1, R2, and R3 represent a hydrocarbon group, a hydroxyl group, or a hydrogen atom. A step of discharging the polyester composition obtained by the production method according to claim 1 in the form of a strand from a discharging die and cooling it by immersing it in water in a water tank,
The process is a method for producing a polyester resin composition, in which the strands are water-cooled immediately after being discharged, taken out from the water tank immediately after solidification, and then air-cooled and then chipped with a cutter. 3. The method for producing a polyester resin composition according to claim 2 , further comprising the step of removing water adhering to the air-cooled strands by suction.