JPH05214221A - Polyester composition - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve the resistance to oxidative decomposition without lowering the mechanical properties of copolyesters containing polyoxyalkylene units. A polyester composition comprising a polyoxyalkylene unit-containing copolyester and 0.2 to 10% by weight of each of the polyoxyalkylene units, a single hindered phenolic compound and both hindered phenolic compounds.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a polyester composition having excellent resistance to oxidative decomposition. The polyester composition of the present invention exhibits excellent hydrophilicity and dyeability derived from the polyoxyalkylene unit-containing copolyester, as well as being capable of maintaining excellent oxidative decomposition resistance for a long period of time. It is useful as a material for fibers, films, sheets and other molded articles having stain resistance, easy dyeability, hygroscopicity, antistatic property and the like.

[0002]

2. Description of the Related Art Polyester fibers typified by polyethylene terephthalate fibers generally have many excellent properties such as easy-care properties and are widely used for various purposes. Therefore, compared with natural fibers such as cotton, hygroscopicity, water absorption, etc.
It is inferior in the property called hydrophilicity, and its use is restricted in many fields. Further, it is known that the dyeability is also problematic in that it has no reactive functional group in the molecule, has high crystallinity and has a dense molecular structure, and has a high glass transition temperature.

Various attempts have been made in the past to solve these problems, but the most commonly known method is to copolymerize a polyoxyalkylene group-containing compound. However, in the copolyester obtained by copolymerizing the polyoxyalkylene group-containing compound,
Since the polyoxyalkylene group part causes oxidative decomposition by the attack of oxygen in the air, it is said that yellowing and a decrease in the degree of polymerization are likely to occur in each step such as polycondensation reaction of the copolyester, spinning, and heat treatment. ing. Therefore,
It is necessary to improve the resistance to oxidative decomposition of these polyoxyalkylene unit-containing copolyesters, and many proposals have been made so far, and it is said that an additive called an antioxidant is effective.

For example, JP-B-44-32311, JP-B-44-12591 and JP-B-44-13271
Publication, Japanese Patent Publication No. 45-7870, Japanese Publication No. 45-2
According to JP-B No. 4023, JP-B No. 47-6426 and JP-B No. 58-5938, easy dyeing excellent in oxidative decomposability is obtained by compounding a polyoxyalkylene glycol copolymerized polyester with a hindered phenol compound. It is said that a polyoxyalkylene glycol copolymerized polyester composition having a hydrophilic property is obtained.

According to Japanese Patent Laid-Open No. 2-38421, a mixture obtained by mixing polyethylene glycol with a hindered phenol compound and heating at a temperature in the range of 50 to 200 ° C. for 1 hour or more is added. The modified polyester thus obtained is said to be excellent in color tone and resistance to oxidative decomposition.

[0006]

SUMMARY OF THE INVENTION From the viewpoint of improving the resistance to oxidative decomposition of polyoxyalkylene unit-containing copolyesters, the present inventors have determined the performance of the various polyoxyalkylene glycol copolyesters or compositions thereof. As a result of evaluation, Japanese Patent Publication No. 44-32311, Japanese Patent Publication No. 44-12591, and Japanese Patent Publication No. 44-13271.
Publication, Japanese Patent Publication No. 45-7870, Japanese Publication No. 45-2
In the copolymerized polyester compositions described in JP-B No. 4023, JP-B No. 47-6426 and JP-B No. 58-5938, a hindered phenolic compound is added in an amount capable of exhibiting a practically sufficient antioxidant effect. in case of,
It was found that the mechanical properties were significantly reduced in the fiberizing process. Also, in the modified polyester described in JP-A-2-38421, oxidative decomposition resistance is greatly reduced as the copolymerization amount of polyethylene glycol increases, and hydrophilicity and oxidative decomposition resistance are practically sufficient. It turns out that there is no compatible product at all levels.

As described above, it has been clarified that the addition of a hindered phenolic compound is effective for improving the oxidative decomposition resistance of the polyoxyalkylene unit-containing copolyester, but it is practically sufficient. It is necessary to add a large amount of hindered phenolic compounds in order to obtain various effects. However, in that case, there is a possibility of causing troubles such as single yarn breakage during spinning and deterioration of mechanical properties of the obtained fiber. Therefore, the color tone and oxidative decomposition resistance are improved without these problems. Technology is desired.

An object of the present invention, therefore, is to provide a polyoxyalkylene unit-containing copolymerized polyester composition capable of maintaining excellent oxidative decomposition resistance for a long period of time.

[0009]

Means for Solving the Problems As a result of intensive studies to achieve the above-mentioned object, the inventors of the present invention have selected one hindered phenol compound as a hindered phenol compound and both hindered phenol compounds. It was found that the above object can be achieved by the combined use, and the present invention was further studied based on these findings, and the present invention was achieved.

That is, the present invention relates to a polyoxyalkylene unit-containing copolyester and an amount of the one-hindered phenolic compound and both hindered compounds in an amount of 0.2 to 10% by weight based on the polyoxyalkylene unit. It is a polyester composition containing a phenolic compound.

The copolyester used in the present invention is
It is a polyester containing a polyoxyalkylene structure in the main chain of the molecule, in the side chain of the molecule, or at the end of the molecule. Such a copolyester can be obtained by, for example, a polymerization reaction using a dicarboxylic acid or its ester-forming derivative, a diol compound or its ester-forming derivative, and a polyoxyalkylene group-containing compound as main monomer components according to a conventional method. Examples of the dicarboxylic acid here include terephthalic acid, isophthalic acid, 1,4-naphthalenedicarboxylic acid,
1,5-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,
4'-biphenyldicarboxylic acid, 3,3'-biphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, 4,4'-diphenylmethanedicarboxylic acid, 4,
4'-diphenylisopropylidene dicarboxylic acid, 1,
2-diphenoxyethane-4 ', 4 "-dicarboxylic acid,
2,5-anthracene dicarboxylic acid, 2,6-anthracene dicarboxylic acid, 2,5-pyridinedicarboxylic acid,
Examples thereof include aromatic dicarboxylic acids such as 3,5-dicarboxybenzenesulfonic acid sodium salt; aliphatic dicarboxylic acids such as adipic acid, azelaic acid and sebacic acid; and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid. These dicarboxylic acids may be used alone or in combination of two or more, but the dicarboxylic acid to be used can be obtained from the viewpoint that a copolyester having excellent mechanical performance required for fiber applications can be obtained. 70 of the acid component
It is desirable that the mol% or more is aromatic dicarboxylic acid, especially terephthalic acid.

Examples of the ester-forming derivative of the above-mentioned dicarboxylic acid include lower alkyl esters such as dimethyl ester of dicarboxylic acid exemplified above. Examples of the diol compound include ethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, nonamethylene glycol, 3-methylpentane-1,5-diol, 2-methyloctane-1,8-. Aliphatic diols such as diol and diethylene glycol; and alicyclic diols such as cyclohexanedimethanol. These diols may be used alone or in combination of two or more, but from the viewpoint of obtaining a copolyester having excellent mechanical performance required for fiber applications, 7 of the diol compounds is used.
0 mol% or more is preferably a linear alkylene glycol having 2 to 6 carbon atoms such as ethylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, and hexamethylene glycol. Examples of the ester-forming derivative of the diol compound include alkylene oxides such as ethylene oxide.

Examples of the polyoxyalkylene group-containing compound include the following general formulas (I), (II) and (III)
Alternatively, the compound represented by (IV) may be mentioned, but these may be used alone or in combination of two or more.

HO (R ₁ O) _n1 H (I)

R ₂ O (R ₃ O) n ₂ H (II)

[0016]

[Chemical 1]

[0017]

[Chemical 2]

(In the above formulas, R ₁ , R ₃ , R ₅ and R ₇ each represent an alkylene group having 2 to 4 carbon atoms, and R ₂ , R ₄
And R ₆ each represent a monovalent hydrocarbon group,
n2, n3, and n4 are numbers representing the average degree of polymerization of the polyoxyalkylene moiety, and are numbers in the range of 10 to 100. )

The above formulas (I), (II), (III) and (I
In V), R ₂ , R ₄ and R ₆ each represent a monovalent hydrocarbon group, and preferred examples include methyl, ethyl and n-.
Propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, n-octyl,
Examples thereof include alkyl groups such as 2-ethylhexyl, n-dodecyl and n-stearyl; cycloalkyl groups such as cyclohexyl; aryl groups such as phenyl and nonylphenyl. Further, R ₁ , R ₃ , R ₅ and R ₇ each represent an alkylene group having 2 to 4 carbon atoms such as an ethylene group and a propylene group, but an ethylene group is more preferable. R ₁ ,
As R ₃ , R ₅ and R ₇ , plural kinds of alkylene groups may coexist in the same polyoxyalkylene group-containing compound molecule, such as a combination of an ethylene group and a propylene group. n1, n2, n3 and n4 are numbers each representing the average degree of polymerization of the polyoxyalkylene moiety, and are 10
It is preferably a number within the range of -100. n1, n
When 2, n3 and n4 are more than 100, the polyoxyalkylene group-containing compound may have poor polymerizability, and the resulting copolyester may be easily colored. The polyoxyalkylene group-containing compound has a polyoxyalkylene unit content of 3 to 5 in the obtained copolyester.
It is desirable to use it in an amount of 0% by weight from the viewpoint of obtaining a polyester having hydrophilicity and dyeability compatible with excellent mechanical performance required as a raw material for molded articles such as fibers, films and sheets. ..

In the copolyester used in the present invention, the main monomer is a dicarboxylic acid or an ester-forming derivative thereof, a diol compound or an ester-forming derivative thereof, and a difunctional compound such as a polyoxyalkylene group-containing compound. However, other bifunctional compounds may be used in combination. Examples of such other bifunctional compounds include aromatic hydroxycarboxylic acids such as β-hydroxyethoxybenzoic acid and p-oxybenzoic acid. In the copolyester used in the present invention, for example, triols such as glycerin and trimethylolpropane; tetraols such as pentaerythritol; tricarboxylic acids such as trimellitic acid and trimesic acid; and tetracarboxylic acids such as pyromellitic acid. A polyfunctional compound having a valence of 3 or more can be used together as a copolymerization component in an amount within a range capable of being melt-molded.

In producing the copolymerized polyester in the present invention, as described above, an operation according to a known method is adopted. For example, a desired dicarboxylic acid such as terephthalic acid is directly esterified with a desired diol such as ethylene glycol, or an ester-forming derivative of the desired dicarboxylic acid such as a lower alkyl ester of terephthalic acid such as dimethyl terephthalate is used. Forming an ester of a dicarboxylic acid and a diol compound or a low polymer thereof, which comprises transesterifying a desired diol such as ethylene glycol or reacting a desired dicarboxylic acid with a desired alkylene oxide such as ethylene oxide. It can be carried out by a first-step reaction, followed by a second-step reaction comprising heating the product under reduced pressure to polycondense until a desired degree of polymerization is reached. A known catalyst can be used in these reactions. Examples of such catalysts include zinc compounds such as zinc acetate and zinc carbonate; manganese compounds such as manganese acetate and manganese carbonate; calcium compounds such as calcium acetate and calcium carbonate; cobalt compounds such as cobalt acetate and cobalt carbonate; barium acetate; Transesterification catalysts such as barium compounds such as barium carbonate and antimony compounds such as antimony oxide,
Examples thereof include germanium compounds such as germanium oxide and polycondensation catalysts such as titanium compounds such as tetraisopropyl orthotitanate.

In the production of the copolyester used in the present invention, a polycondensation reaction is carried out so that the polyester produced has an intrinsic viscosity of 0.5 dl / g or more measured at 30 ° C. in a mixed solvent of equal weight of phenol and tetrachloroethane. Is generally preferred. With a copolyester having an intrinsic viscosity of 0.5 dl / g or more, mechanical properties such as strength are sufficient, and the number of yarn breakages when subjected to melt spinning is small. On the other hand, in the case of a copolyester having an intrinsic viscosity that is too large, the melt viscosity may become too large and the spinnability may become poor, so the mechanical performance becomes particularly good, and troubles during the fiberizing process may be reduced. Therefore, the polycondensation reaction time is such that the intrinsic viscosity of the obtained copolyester is within the range of 0.55 to 1.5 dl / g, and particularly within the range of 0.6 to 1.0 dl / g. preferable.

In order to copolymerize the polyoxyalkylene group-containing compound with the polyester molecule, the polycondensation reaction may be carried out at any stage until the completion of the polycondensation reaction, for example, before the reaction in the first stage, during the reaction, or during the reaction. After the completion, the polyoxyalkylene group-containing compound may be added to the reaction system at any stage such as during the reaction in the second stage, and the reaction may be completed after the addition.

The polyester composition of the present invention contains a specific amount of one hindered phenolic compound and both hindered phenolic compounds as essential components. The hindered phenolic compound is a phenolic compound having a sterically hindering substituent on one or both of two carbon atoms adjacent to the carbon atom having a phenolic hydroxyl group, and in the present invention, only one is steric. "Half-hindered phenolic compounds" are those having a hindering substituent and a hydrogen atom on another adjacent carbon atom; a non-sterically hindering substituent such as a primary alkyl group such as a methyl group and an ethyl group. Good,
Further, a compound having a sterically hindering substituent on both is referred to as "both hindered phenol compound". As the sterically hindering substituent here, a tertiary alkyl group such as a tert-butyl group is preferable. Preferable specific examples of the above-mentioned one-sided hindered phenol compounds include respective compounds represented by the following formula.

[0025]

[Chemical 3]

[0026]

[Chemical 4]

[0027]

[Chemical 5]

[0028]

[Chemical 6]

[0029]

[Chemical 7]

Further, preferred specific examples of both hindered phenol compounds include respective compounds represented by the following formula.

[0031]

[Chemical 8]

[0032]

[Chemical 9]

[0033]

[Chemical 10]

The content of the one-hindered phenolic compound and both hindered phenolic compounds in the polyester composition of the present invention is as follows, based on the weight of the polyoxyalkylene units contained in the polyoxyalkylene unit-containing copolymerized polyester. It is necessary that the amount be in the range of 0.2 to 10% by weight, and preferably in the range of 0.5 to 5% by weight. When the content is less than 0.2% by weight, the oxidative decomposition resistance of the copolyester may be insufficiently improved, and when the content exceeds 10% by weight, the oxidative decomposition resistance of the obtained copolyester is no longer obtained. Is not observed, and on the contrary, there is a risk of causing troubles such as single yarn breakage in the spinning step, and further, the mechanical properties of the obtained fiber may be deteriorated.

From the viewpoint of improving the oxidative decomposition resistance of the copolyester with almost no deterioration in mechanical properties, the total content of one hindered phenolic compound and both hindered phenolic compounds is It is preferably within the range of 1 to 10% by weight based on the weight of the oxyalkylene unit. Furthermore, in the present invention, the content of the one-sided hindered phenolic compound is Y (% by weight) based on the polyoxyalkylene unit in the copolyester,
The content of both hindered phenolic compounds is Z relative to the polyoxyalkylene unit in the copolyester.
When represented by (% by weight), it is preferable that the value of Y / Z is within the range of 0.3 to 3 because a copolymerized polyester composition having particularly excellent resistance to oxidative decomposition can be obtained.

The polyester composition of the present invention may contain optional additives such as anti-coloring agent, heat-resistant agent, fluorescent bleaching agent, flame retardant, matting agent, coloring agent and inorganic fine particles, if necessary. May be.

As the method for producing the polyester composition of the present invention, a method of blending desired amounts of the one-hindered phenolic compound and the both hindered phenolic compounds after the above-mentioned polyoxyalkylene unit-containing copolymerized polyester is manufactured. Although it can be mentioned, from the viewpoint of suppressing the coloring phenomenon due to oxidative decomposition that may occur during the production of the copolyester, the reaction at any stage until the polycondensation reaction for obtaining the copolyester is completed. A method of adding one hindered phenolic compound and both hindered phenolic compounds to the system is more preferable. That is, before the start of the esterification reaction or transesterification reaction, during the reaction or after the reaction, and at any stage selected from the polycondensation reaction, one hindered phenolic compound and both hindered phenolic compounds By adding it to the reaction system and carrying out the rest of the reaction by a predetermined method, it is possible to obtain a polyester composition which is excellent not only in oxidative decomposition resistance, hydrophilicity and dyeability but also in its own good color tone. In the production of the copolyester used in the present invention, usually, most of the polyoxyalkylene group-containing compound used reacts to form a polyoxyalkylene unit in the polyester molecule. Therefore, in order to obtain a polyester composition containing a one-hindered phenolic compound and both hindered phenolic compounds at a desired ratio in the polyoxyalkylene unit standard in the polyester, the blending ratio of these hindered phenolic compounds, It is practically easy to set it on the basis of the polyoxyalkylene unit in the polyoxyalkylene group-containing compound used for producing the copolyester.

It is not necessary to employ a particular method as a method for molding the polyester composition of the present invention. Like the usual polyester, the melt molding method is optionally adopted to obtain an arbitrary molded product such as a fiber, a film, a sheet and the like. For example, when forming into fibers, a melt spinning method can be adopted. Fibers comprising the polyester composition of the present invention may be circular depending on the shape of the nozzle used; or trilobal, tetralobal, pentalobal, hexalobal, heptagonal,
It may have an arbitrary cross-sectional shape such as a multilobe shape such as an octalobe shape, or an irregular shape such as a T shape, and is not limited to a solid fiber and may be a hollow fiber. The spun raw yarn produced by melt-spinning the polyester composition of the present invention can be made into a drawn yarn by drawing according to a conventional method. The drawn yarn can be further subjected to desired post-treatments such as heat treatment, crimping and cutting according to a conventional method.

The fiber comprising the polyester composition of the present invention can be made into a fiber product by itself, or may be mixed with other fibers to form a fiber product.

[0040]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Moreover, each physical property value in an Example is a value obtained by measuring according to the following method.

(1) Intrinsic viscosity of polymer [η] 0.25 g / dl, 0.50 of the target polymer was prepared by using an equal weight mixed solvent of phenol and tetrachloroethane.
It was determined from the three reduced viscosities measured at a temperature of 30 ° C. for solutions of three concentrations of g / dl and 1.0 g / dl.

(2) Color tone of polymer (yellowness: b value) A cylindrical polymer chip having a diameter of 2 mm and a length of 4 mm was used as a sample, and a color computer (Suga Test Instruments Co., Ltd.) was used.
Manufactured by SM Color Computer, SM-3 type).

(3) Oxidative decomposition resistance The oxidative decomposition resistance was evaluated by determining the viscosity retention rate from the intrinsic viscosities before and after the treatment of the polymer which was made into fibers and treated with hot air at 150 ° C. for 1 hour. The fiberizing method is as follows.
The polymer was spun with a circular nozzle at 280 ° C., stretched in hot water at 75 ° C., heat-fixed, and then mechanically crimped to 0.1 wt% of an oil agent containing an ethylene oxide adduct of stearyl phosphate as a main component. To 150 ℃
Was subjected to a relaxation treatment for 10 minutes and then cut into a length of 51 mm to obtain raw cotton.

The polyoxyalkylene group-containing compound used in each example was subjected to NMR analysis on the copolyester produced in the same manner as in the example except that the hindered phenol compound was not added. Were found to constitute the polyoxyalkylene units in the copolyester molecule. Therefore, in the present examples and comparative examples, the weight percentage of the added polyoxyalkylene group-containing compound based on the weight of the obtained polyester is the weight of the polyoxyalkylene unit in the polyester molecule based on the weight of the obtained polyester. Substantially equal to the percentage. The weight percentage of the added hindered phenolic compound based on the weight of the added polyoxyalkylene group-containing compound is substantially equal to the weight percentage of the hindered phenolic compound based on the weight of the polyoxyalkylene unit in the polyester molecule. equal.

Examples 1 to 3 996.8 g terephthalic acid and ethylene glycol 7
Charge 50 g to the esterification reactor and bring to 2.5 at 230 ° C.
The esterification reaction was carried out for 2 hours under a pressure of kg / cm ² . Then, the obtained reaction product was transferred to a polycondensator previously heated to 230 ° C.

HO (CH ₂ CH ₂ O) ₄₅ H

The polyoxyalkylene group-containing compound represented by the formula (1) is added in an amount shown in Table 1, and the compound represented by the formula (3) is added as a one-hindered phenol compound.
3,5-tris (4-t-butyl-3-hydroxy-
2,6-Dimethylbenzyl) -1,3,5-triazine-2,4,6- (1H, 3H, 5H) -trione (manufactured by American Cyanamid, Syanox 1790)
As both hindered phenol compounds,
Pentaerythrityl-tetrakis [3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate] (Irganox 1010, manufactured by Ciba Geigy) was added in an amount shown in Table 1, and 0.4 g of antimony trioxide and 0.12 g of phosphorous acid were further added to prepare a polycondensation reaction system. While increasing the temperature of the polycondensation reaction system from 230 ° C to 280 ° C over 45 minutes, the pressure was gradually reduced to 0.1 mmHg, and then at 280 ° C, the melt viscosity of the system was polyethylene terephthalate having an intrinsic viscosity of 0.70 dl / g. The polycondensation reaction was continued until the melt viscosity at 280 ° C. of the columnar chips (diameter 2)
mm, length 4 mm).

Table 1 shows the evaluation results of the intrinsic viscosity, color tone and resistance to oxidative decomposition of the obtained copolyester composition.

Examples 4 and 5 In the same manner as in Example 1, except that the addition amount of the polyoxyethylene group-containing compound was changed to the amount shown in Table 1, the corresponding copolyester compositions were obtained.

Table 1 shows the evaluation results of the intrinsic viscosity, color tone and resistance to oxidative decomposition of the obtained copolyester composition.

Examples 6 to 9 The same as in Example 1 except that the corresponding polyoxyalkylene group-containing compound represented by the following formula was used as the comonomer polyoxyethylene group-containing compound in the amounts shown in Table 1, respectively. Thus, corresponding copolyester compositions were obtained.

Comonomers used in Example 6:

[Chemical 11]

Comonomers used in Example 7:

[Chemical 12]

Comonomer used in Example 8: C ₈ H ₁₇ O (CH ₂ CH ₂ O) ₈₀ H

Comonomers used in Example 9:

[Chemical 13]

Table 1 shows the evaluation results of the intrinsic viscosity, color tone and resistance to oxidative decomposition of the obtained copolyester composition.

Example 10 In Example 1, instead of 996.8 g of terephthalic acid, 947.0 g of terephthalic acid and 49.8 g of isophthalic acid were used.
A corresponding copolyester composition was obtained in the same manner except that the mixture of was used.

Table 1 shows the evaluation results of the limit, color tone and oxidative decomposition resistance of the obtained copolyester composition.

[0059]

[Table 1]

Comparative Example 1 A corresponding copolyester was obtained in the same manner as in Example 1, except that neither the one-hindered phenol type compound nor the both hindered phenol type compounds were used.

Table 2 shows the evaluation results of the intrinsic viscosity, color tone and oxidative decomposition resistance of the obtained copolyester.

Comparative Example 2 A corresponding copolyester composition was obtained in the same manner as in Example 1 except that only the one-hindered phenolic compound was not used.

Table 2 shows the evaluation results of the intrinsic viscosity, color tone, and resistance to oxidative decomposition of the obtained copolyester composition.

Comparative Example 3 A corresponding copolyester composition was obtained in the same manner as in Example 1 except that both hindered phenol compounds were not used.

Table 2 shows the evaluation results of the intrinsic viscosity, color tone and resistance to oxidative decomposition of the obtained copolyester composition.

Comparative Example 4 A corresponding copolyester composition was prepared in the same manner as in Example 1 except that the amounts of the one-hindered phenolic compound and the both hindered phenolic compounds used were changed to the amounts shown in Table 2. Got

When this copolyester composition was made into fibers, many yarn breakages occurred during spinning, and the drawability of the obtained spun raw yarn was also poor. It didn't come.

[0068]

[Table 2]

[0069]

INDUSTRIAL APPLICABILITY The polyester composition provided by the present invention has high resistance to oxidative decomposition despite containing a polyester containing a polyoxyalkylene chain in the molecule.

Therefore, the polyester composition of the present invention is
It is possible to mold the polyester while suppressing a decrease in the molecular weight and deterioration of the color tone, and to provide a molded product having good mechanical properties and color tone. Moreover, the obtained molded product effectively exhibits the resistance to oxidative decomposition, hydrophilicity and dyeing property derived from the polyester composition of the present invention.

Claims (1)

[Claims] 1. A polyoxyalkylene unit-containing copolyester and an amount of one hindered phenolic compound and both hindered phenolic compounds in an amount within the range of 0.2 to 10% by weight based on the polyoxyalkylene unit. A polyester composition containing: