TWI753033B - a polyester - Google Patents

Abstract

The invention discloses a polyester. The polyester is a polymer formed by an aromatic dicarboxylic acid or a derivative thereof and an aliphatic diol as main constituents, and polyethylene glycol as a copolymerization constituent, wherein polyethylene glycol is used as a copolymer. The number-average molecular weight of the diol is 2000-30000 g/mol, and the copolymerization rate is 25-55 wt%. The polyester of the present invention is excellent in hygroscopicity of fibers obtained by spinning alone or in combination with other components by conventional spinning methods, as well as false twisted yarns and fiber structures formed therefrom. Therefore, it can be used for applications requiring comfort and quality.

Description

a polyester

The present invention is a polyester with excellent hygroscopicity.

Due to its excellent properties, polyester has a wide range of applications in the fields of fibers, films, and plastics. However, due to the regular structure and strong hydrophobicity of polyester, compared with natural fibers such as cotton or hemp, polyester fibers have poor water absorption and hygroscopicity, which greatly limits the application of polyester fibers in environments requiring hygroscopicity. . When the textile obtained from polyester fiber is made into intimate clothing, because polyester fiber has poor hygroscopicity, it will give people a feeling of stuffiness, so polyester fiber is especially not suitable for summer clothing.

In order to solve the problem of poor water absorption and hygroscopicity of polyester fibers, those skilled in the art have tried many methods. For example, the modification of the fiber surface is mainly to improve the hygroscopicity of the fiber by using the capillary principle after making the fiber surface porous. Modification of the fiber surface can also be achieved by methods such as electrical discharge treatment, photografting modification, and low temperature plasma treatment. However, after the fibers obtained by these methods are made into fabrics, they do not have a good effect on reducing the feeling of steaming and heat in the state of sweating, and they will not have the cooling feeling of natural fibers such as cotton and hemp. In addition to these methods, there is also a method of wrapping a hydrophilic film on the surface of the fiber, but this method often has the disadvantages of poor affinity between the fiber and the film, and poor durability after washing.

The hygroscopic properties of fibers can also be improved by chemically grafting polyester fibers. For example, after graft copolymerization of about 15% of acrylic acid and methacrylic acid on polyethylene terephthalate (PET) fiber, and sodium ion exchange treatment, a moisture absorption rate equivalent to that of cotton can be obtained. However, the moisture absorption speed of this kind of fiber is very slow, and the basic properties of polyester fiber are greatly lost, which basically has no application value, so there has been no industrial production.

In addition, high molecular weight polyether compounds are also used to improve hygroscopicity, but high molecular weight polyether compounds are not completely copolymerized with the polyester matrix, and most of them exist in the polyester in the state of separate phases, which will lead to polymerization. When the material is melted and retained, it coarsens to form an unstable phase-separated structure, and the discharge after the polymerization reaction ends and the discharge of the gold part of the mouth during spinning is unstable, resulting in the final fiber size spot, large dye spot, and hairiness. Japanese Patent Laid-Open No. 2007-70467 uses special PEG to copolymerize with PET to improve the hygroscopic properties of PET. However, if the addition amount of PEG is too small, it cannot bring high hygroscopicity, so a higher addition amount is required. As a result, the basic properties of the fiber will be lost after the polyester fiber is formed, and the heat resistance, hot water resistance and oxidation resistance will be lost. The heating performance is greatly deteriorated, and the use value becomes very low.

The object of the present invention is to provide a polyester having excellent hygroscopicity, and the fibers obtained by spinning the polyester have excellent hot water resistance and oxidation heat generation resistance.

The technical solution of the present invention is as follows:

其中，R1為由碳氫、氧、氮中的一或多種結合形成的基團；R2為由氫、碳氫、氧、氮中的一或多種結合形成的基團。 A polyester, the polyester is a polymer formed of an aromatic dicarboxylic acid or a derivative thereof and an aliphatic diol as the main component, and polyethylene glycol as a copolymerization component, wherein the The number average molecular weight is 2000~30000g/mol, the copolymerization rate is 25~55wt%, and the polyester contains a semi-hindered phenolic antioxidant as shown in formula 1,

Wherein, R1 is a group formed by the combination of one or more of hydrocarbon, oxygen and nitrogen; R2 is a group formed by the combination of one or more of hydrogen, hydrocarbon, oxygen and nitrogen.

The content of the semi-hindered phenolic antioxidant preferably accounts for 1.0-8.0 wt % of the total weight of the polyester.

-2,4,6-(1H,3H,5H)-三酮，

The semi-hindered phenolic antioxidant is preferably the antioxidant 3,9-bis[1,1-dimethyl-2-[(3-tert-butyl-4-hydroxy-5-methyl shown in formula 2) phenyl)propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, or 1,3,5-tris(4-th Tributyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-tri

-2,4,6-(1H,3H,5H)-trione,

The copolymerization rate of the polyethylene glycol is preferably 35 to 55 wt%.

The aliphatic diol is preferably ethylene glycol or 1,4-butanediol; when the aliphatic diol is preferably ethylene glycol, the number average molecular weight of the polyethylene glycol is preferably 4000~30000g/ mol.

The copolymerization rate of polyethylene glycol in the polyester of the present invention is high, the hygroscopicity of polyester chips is excellent, and the difference between the difference in hygroscopicity before and after fiber dyeing of the polyester fiber is small. At the same time, polyester has good heat resistance, excellent yellowing resistance and high application value.

The polyester of the present invention is a polyether ester obtained by copolymerizing aromatic dicarboxylic acids or derivatives thereof, aliphatic diols as main monomers, and polyethylene glycol as copolymerization components, and has good heat resistance and mechanical properties.

Described aromatic dibasic carboxylic acid or its derivative, can specifically cite terephthalic acid, isophthalic acid, phthalic acid, isophthalic acid-5-sodium sulfonate, isophthalic acid- 5-Lithium sulfonate, 5-(tetraalkyl)-isophthalic acid phosphorus compound, 4,4'-biphenyl dicarboxylic acid, 2,6-naphthalenedicarboxylic acid, etc., but not limited to the above substances, Among them, terephthalic acid is preferred.

Specific examples of the aliphatic diols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, hexanediol, cyclohexanehexanediol, diethylene glycol, and hexaethylene glycol. Methyl glycol, neopentyl glycol, etc., but not limited to the above substances. In particular, ethylene glycol, propylene glycol, and 1,4-butanediol are preferable because they have good availability during production and use. From the viewpoint of heat resistance and mechanical properties, ethylene glycol is more preferable; from the viewpoint of crystallinity, 1,4-butanediol is more preferable.

In the polyester of the present invention, the number-average molecular weight of polyethylene glycol as a copolymerization component can be appropriately selected within the range where the polyester has crystallinity. The copolymerization ratio of polyethylene glycol in the polyester of the present invention is 25 to 55 wt %. When the copolymerization rate of polyethylene glycol is less than 25 wt %, the dischargeability of the polyester is poor; when the copolymerization rate of polyethylene glycol is greater than 55 wt %, the physical properties of the fibers formed by the obtained polyester decrease. When the copolymerization rate of polyethylene glycol is between 25 and 35wt%, the discharge property of the obtained polyester is general, so in order to obtain polyester with better discharge property, the preferred copolymerization rate of polyethylene glycol in the present invention is 35%. ~55wt%.

The preferable range varies depending on the composition of the polyester. For example, in the case where the aliphatic diol of the polyester is ethylene glycol, if the molecular weight of the polyester is too low, the polyethylene glycol will be degraded seriously because the polymerization temperature is too high, and the final polyester, or even made into The moisture absorption rate of the fibers will decrease. At the same time, when the constituent aliphatic diol of the polyester is 1,4-butanediol, compared with the above-mentioned case of using ethylene glycol, the degradation of polyethylene glycol is relatively less serious due to the low polymerization temperature, so The hygroscopicity of polyester, even after being made into fibers, can be improved.

When the aliphatic diol of the present invention is ethylene glycol, the number average molecular weight of polyethylene glycol is preferably 4000-30000 g/mol, and the copolymerization rate of polyethylene glycol is preferably 35-55 wt%. When the number-average molecular weight of polyethylene glycol is 4000 g/mol or more, polyester has high hygroscopicity, and fibers excellent in hygroscopicity can be obtained by single spinning or combined spinning. At the same time, the decrease of the crystallinity of polyester and the decrease of the extrapolated melting initiation temperature can be suppressed. Since the occurrence of yarn breakage and hairiness after polyester spinning is reduced, the processability is good, and it is dyed when forming fiber structures such as woven fabrics and knitted fabrics. The occurrence of spots and hairiness is reduced, and the quality is excellent. On the other hand, when the number-average molecular weight of polyethylene glycol is 30,000 g/mol or less, polycondensation reactivity is high, unreacted polyethylene glycol is reduced, elution in hot water during hot water treatment such as dyeing can be suppressed, and hot water Hygroscopicity after treatment can be maintained. The number average molecular weight of polyethylene glycol is preferably 25,000 g/mol or less, more preferably 20,000 g/mol or less.

At the same time, when the copolymerization ratio of polyethylene glycol is 35 wt% or more, polyester has high hygroscopicity, and fibers excellent in hygroscopicity can be obtained by single spinning or combined spinning. On the other hand, when the copolymerization ratio of polyethylene glycol is 55 wt% or less, the occurrence of yarn breakage and hairiness after polyester spinning is reduced, the processability is good, and dye spots and hairiness are formed when fiber structures such as woven fabrics and knitted fabrics are formed. The production is less and the quality is excellent. At the same time, the elution of polyethylene glycol during hot water treatment such as dyeing can be suppressed, and the hygroscopicity of the fiber can be maintained after the hot water treatment.

When the aliphatic diol of the present invention is 1,4-butanediol, the number-average molecular weight of polyethylene glycol is preferably 2000-30,000 g/mol, and the copolymerization rate of polyethylene glycol is preferably 35-55 wt% . When the number-average molecular weight of polyethylene glycol is 2,000 g/mol or more, polyester has high hygroscopicity, and fibers excellent in hygroscopicity can be obtained by single spinning or combined spinning. At the same time, the decrease in the crystallinity of the polyester can be suppressed. At the same time, if the number average molecular weight of polyethylene glycol is 2000 g/mol or more, the decrease of the crystallinity of polyester and the decrease of the extrapolated melting start temperature can be suppressed, and the occurrence of yarn breakage and hairiness due to drawing and false twisting process can be reduced. , The processability is good, the generation of dye spots and hairiness is reduced when forming fiber structures such as fabrics and knitted fabrics, and the quality is excellent. On the other hand, when the number-average molecular weight of polyethylene glycol is 30,000 g/mol or less, polycondensation reactivity is high, unreacted polyethylene glycol is reduced, elution in hot water during hot water treatment such as dyeing can be suppressed, and hot water The hygroscopicity after the treatment can be maintained. The number average molecular weight of polyethylene glycol is preferably 27,000 g/mol or less, more preferably 25,000 g/mol or less, and most preferably 20,000 g/mol or less. At the same time, when the copolymerization ratio of polyethylene glycol is 35 wt% or more, polyester has high hygroscopicity, and fibers excellent in hygroscopicity can be obtained by single spinning or combined spinning. On the other hand, when the copolymerization ratio of polyethylene glycol is 55 wt% or less, the occurrence of yarn breakage and hairiness due to drawing and false twisting process is reduced, and the workability is good, and dye spots and hairiness are formed when fiber structures such as woven fabrics and knitted fabrics are formed. The production is less and the quality is excellent. At the same time, elution in hot water during hot water treatment such as dyeing can be suppressed, and hygroscopicity after hot water treatment can be maintained.

It is well known that when a large amount of polyether compounds is added to polyester, the hygroscopicity of polyester is greatly reduced after being formed into fibers due to the thermal oxidative decomposition of ether bonds. Therefore, in the synthesis process of polyester, hindered phenolic antioxidants are generally added. However, after polyester is made into fibers, in the high-temperature dyeing process, the oxidatively decomposed ether bond free radicals attack the phenolic hydroxyl groups of hindered phenolic antioxidants. Para, generate quinone yellow substances. The same machine rotation will also generate yellow substances after the action with NO ₂ , which makes the fiber fastness to nitrogen and oxygen unqualified and affects the performance of the fiber. When the copolymerization rate of polyethylene glycol is lower than 25wt%, the amount of hindered phenolic antioxidants added is generally less, so the above-mentioned yellowing problem will not occur; however, when the copolymerization rate of polyethylene glycol is higher than 25wt% , the yellowing problem will be more serious. The present invention uses the semi-hindered phenolic antioxidant shown in formula 1. Even if there is an ether bond free radical formed after being decomposed by thermal oxidation, because the ortho-position of the phenolic hydroxyl group of the semi-hindered phenolic antioxidant is a methyl group, the steric hindrance effect is relatively high. small, the ether bond free radical will attack the meta position of the phenolic hydroxyl group of the semi-hindered phenolic antioxidant, and will not generate yellow quinones,

Wherein, R1 is a group formed by the combination of one or more of hydrocarbon, oxygen and nitrogen; R2 is a group formed by the combination of one or more of hydrogen, hydrocarbon, oxygen and nitrogen.

-2,4,6-(1H,3H,5H)-三酮，添加量根據聚乙二醇的量而改變，最終聚酯中半受阻酚類抗氧化劑的含量較佳1.0~8.0wt%。半受阻酚類抗氧化劑的含量太低的話，使得聚酯形成纖維後的抗氧化性能差，聚乙二醇氧化分解後聚酯纖維的吸濕性下降；半受阻酚類抗氧化劑的含量太高的話，由於抗氧劑自身的分解也會使得聚酯纖維發生黃變。 The semi-hindered phenolic antioxidant of the present invention is preferably 3,9-bis[1,1-dimethyl-2-[(3-tert-butyl-4-hydroxy-5-methylphenyl)propane] Ethyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, or 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6 -Dimethylbenzyl)-1,3,5-tris

-2,4,6-(1H,3H,5H)-trione, the addition amount varies according to the amount of polyethylene glycol, and the content of the semi-hindered phenolic antioxidant in the final polyester is preferably 1.0~8.0wt%. If the content of semi-hindered phenolic antioxidants is too low, the antioxidant properties of polyester after forming fibers will be poor, and the hygroscopicity of polyester fibers will decrease after oxidative decomposition of polyethylene glycol; the content of semi-hindered phenolic antioxidants will be too high. If so, the polyester fiber will also turn yellow due to the decomposition of the antioxidant itself.

In the present invention, the polyester is the moisture absorption rate

A polyetherester compound with a difference (ΔMR) of 13.0 wt% or more. The difference in moisture absorption rate (ΔMR) in the present invention refers to a value measured by the method described in the specification. The polyester can be spun by conventional spinning methods alone or combined with other component polymers to obtain fibers with excellent hygroscopicity.

In the present invention, the fiber obtained by the conventional single or composite spinning method of the polyester, after being treated with hot water at 130°C, compared with the non-hot water treatment, the change of the color tone L value of the fiber is less than 6, preferably 4 or less. On the other hand, after the fiber has been tested for nitroxide fastness, the hue yellowing value ΔYI is 10.0 or less, preferably 8.0 or less, more preferably 7.5 or less. When △YI is below 7.5, the fastness to nitrogen and oxygen reaches grade 4-5, and when △YI is above 7.5, the fastness to nitrogen and oxygen is grade 4.

In the synthesis of the above polyester, a compound containing a titanium element or an antimony element may be added as a catalyst. Due to the high catalytic activity of titanium-containing catalysts, it is easy to promote side reactions and affect the color stability of the final polyester fiber. Therefore, when selecting titanium-containing catalysts, the addition amount should preferably be controlled at 10-150ppm equivalent to polyester in terms of titanium element. within the range. When the compound of antimony element is used as a catalyst, the addition amount is in the range of 150-300 ppm equivalent to polyester in terms of antimony element.

In the above polyester synthesis, various auxiliary modifiers can also be added. Auxiliary modifiers, specifically, other types of antioxidants, compatibilizers, plasticizers, ultraviolet absorbers, optical brighteners, antibacterial agents, nucleating agents, heat stabilizers, anti-charge agents, and matting agents can be listed , defoamer, dyes, pigments, fragrances, etc., but not limited to the above substances. The above-mentioned auxiliary additives may be used alone or in combination.

The extrapolated melting onset temperature of the polyester of the present invention is above 180°C. The extrapolated melting onset temperature of the polyester of the present invention means a value calculated according to the method described in the specification. When a plurality of melting peaks are observed, calculation is performed from the melting peak with the lowest temperature. When the extrapolated melting start temperature of polyester is 180°C or higher, the occurrence of yarn breakage and hairiness after polyester is formed into fibers is reduced, the processability is good, and the occurrence of dye spots and hairiness when forming fiber structures such as woven fabrics and knitted fabrics is reduced. , excellent quality.

The polyester of the present invention is excellent in hygroscopicity of fibers obtained by spinning alone or in combination with other components by conventional spinning methods, as well as false twisted yarns and fiber structures formed therefrom. Therefore, it can be used for applications requiring comfort and quality. For example, general clothing application, sports clothing application, bedding application, interior decoration application, material application, etc. are not limited to the above-mentioned ones.

Hereinafter, the present invention will be described in detail through specific embodiments. Meanwhile, each characteristic value in the examples was tested by the following methods.

A. Difference in moisture absorption between polyester and fiber (△MR)

The polyester and fiber were used as samples, and after drying with hot air at 60°C for 30 minutes, they were left standing for 24 hours in a constant temperature and humidity machine LHU-123 manufactured by ESPEC at a temperature of 20°C and a humidity of 65% RH, and the weight of the polymer was measured. (W1); Next, it was left to stand in a constant temperature and humidity machine with a temperature of 30° C. and a humidity of 90% RH for 24 hours, and the weight of the polymer was measured as (W2). Then, it was hot-air-dried at 105 degreeC for 2 hours, and the polymer weight after absolute drying was measured as (W3). Calculate the moisture absorption rate MR1 (%) after standing for 24 hours from a dry state to a 20°C, humidity 65%RH environment using the weights W1 and W3 of the polymers according to the following formula, and use the weight W2 of the polymer according to the following formula , W3 Calculate the moisture absorption rate MR2 (%) after standing for 24 hours in a dry state to 30 ℃, humidity 90%RH environment, and then calculate the moisture absorption rate difference (△MR) according to the following formula. In addition, one sample is measured 5 times, and the average value is taken as the difference in moisture absorption rate (ΔMR), MR1(%)={(W1-W3)/W3}×100, MR2(%)={(W2-W3) /W3}×100, moisture absorption difference (△MR) (%)=MR2-MR1.

B. Hot water yellowing properties of fibers

The polyesters prepared in the examples, the fibers formed by spinning alone or in combination with other components by conventional methods, were subjected to hot water treatment under the condition of 130 ° C × 20 minutes, and the obtained samples were measured with a color difference meter (USTC). -datacolor) L value was measured as L2, L value before hot water treatment was measured as L1, and L2-L1 was the yellowing value of hot water treatment.

C. Fiber yellowing value test

The polyesters obtained in the examples were used as test samples after spinning alone or in combination with other components by conventional methods. NOx gas generating agent (85% phosphoric acid and 2% nitrous oxide) was placed in a closed container. Nitric acid aqueous solution), then arrange the sample and blue standard dyeing in the container, when the color of the blue standard cloth fades to the standard grayscale plate No. 3, replace the blue standard dyeing cloth, when the color reaches the standard grayscale plate 3 again No., take out the sample, wash it twice, and dry it. Yellowing values were determined by a Datacolor 650 spectrophotometer.

D. Copolymerization rate of polyethylene glycol

Copolymerization rate of polyethylene glycol: (peak area of H in ether bond/number of H in ether bond × molecular weight of structural unit of polyether compound)/[(peak area of H in ether bond/number of H in ether bond Number × molecular weight of structural unit of polyether compound) + (peak area of H in isophthalic acid containing sodium sulfonate/3 × molecular weight of ester formed by isophthalic acid containing sodium sulfonate) + H in PTA Peak area/4 x molecular weight of PET + peak area of H of EG unit structure in polyester/4 x molecular weight of EG unit structure].

E. Number average molecular weight (Mn) of polyethylene glycol contained

Weigh 50 mg of sample with a bottle, add 1 mL of ammonia water to seal, and heat at 120°C for 3 hours. After cooling, the samples were pulverized and heated at 120°C for a further 2 hours. After cooling, 1Ml of distilled water and 1.5mL of 6M hydrochloric acid were added, and the volume was adjusted with a 5ML volumetric flask. After telecentric separation (3500 rpm×10 minutes), it was filtered with a 0.45 μm mesh, and the obtained filtrate was subjected to GPC test. This sample was subjected to a GPC test (Alliance 2690 manufactured by Waters) under the following conditions. Impurities with a molecular weight lower than 1800 cannot be separated, and the number average molecular weight is obtained in addition to that;

Detector: RI-8020 made by Japan "Tosoh", sensitivity 128x

Column: TSKgelG3000PWXL I manufactured by Japan "Tosoh"

Solvent: 0.1M aqueous sodium chloride solution

Injection volume: 200μm

Column temperature: 40℃

Standard substance: polyethylene glycol (Mn106~101000g/mol manufactured by "AMR Co., Ltd.").

F. Content of semi-hindered phenolic antioxidants and hindered phenolic antioxidants

Pre-treatment: take 8g of polyester, and use 150ml of solvent toluene for circulation treatment for 35 minutes; after treatment, cool it to 100 degrees, and then pour it into a telecentric separation tube; then carry out telecentric separation, take the upper layer of liquid and filter it with a 0.45μm filter; Then, it was diluted with methanol, and the supernatant liquid was collected by centrifugation; finally, the internal standard was added, filtered through a 0.45 μm filter, and then measured by HPLC.

HPLC determination: mobile phase A/B: methanol/water (12%); flow rate: 1.3 ml/min; column temperature: 40 degrees; ultraviolet wavelength: 284 nm; time: 15 min.

G. Extrapolated melting onset temperature

The polymer of the core component, the sheath component, and the fibers obtained in the examples were taken as samples, and the extrapolated melting onset temperature was measured using a Q2000 differential scanning calorimeter (DSC) manufactured by TA Instruments. First, a 5 mg sample was heated from 0°C to 280°C at a temperature increase rate of 50°C/min in a nitrogen atmosphere, and kept at 280°C for 5 minutes to eliminate thermal history. Then, it was quenched from 280°C to 0°C, and then heated again from 0°C to 280°C at a rate of 3°C/min. The temperature adjustment range was ±1°C, and the temperature was adjusted after a period of 60 seconds, and then the temperature was increased to perform TMDSC measurement. The extrapolated melting onset temperature was calculated from the melting peak observed in the second heating process in accordance with the standards of JISK7121:1987 (Method for Measuring Transition Temperature of Plastics) 9.1. One sample was measured three times, and the average value was used as the extrapolated melting onset temperature. In addition, when a plurality of melting peaks are observed, the extrapolated melting onset temperature is calculated from the melting peak on the lowest temperature side.

[Example 1]

-2,4,6-(1H,3H,5H)-三酮(CN1790)，攪拌10分鐘後向反應體系裡導入氮氣回至常壓，停止縮聚反應得到共聚酯。 10.9Kg of terephthalic acid and 4.7Kg of ethylene glycol were put into the esterification kettle, stirred and heated to 230° C. to carry out the esterification reaction, and then moved to the polycondensation kettle, and the polyethylene glycol of 35wt% relative to the total amount of the final polyester was added 8300 (polyethylene glycol with a number-average molecular weight of 8300 g/mol, abbreviated as PEG8300), with antimony trioxide having a content of 250 ppm relative to the total amount of the final polyester in terms of antimony element as a polymerization catalyst, and adding antimony trioxide relative to the total amount of the final polyester. The amount of stabilizer trimethyl phosphate was 250ppm, and after 5 minutes, the pressure was reduced and the temperature was raised. After reaching the final temperature of 285 ° C and the final pressure, 1.0 wt% of the semi-hindered phenolic antioxidant was added to the reaction system relative to the total amount of the final polyester. 1,3,5-Tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-tris

-2,4,6-(1H,3H,5H)-trione (CN1790), after stirring for 10 minutes, nitrogen was introduced into the reaction system to return to normal pressure, and the polycondensation reaction was stopped to obtain a copolyester.

The polyester chips obtained above were melt-spun at a spinning speed of 3 Km/min to obtain pre-oriented yarns. Then, the obtained pre-oriented yarn is subjected to false twisting processing, processing conditions: the temperature of the first hot box is 180°C, the temperature of the second hot box is normal temperature, and the stretching ratio is 1.7 to obtain a highly hygroscopic polyester fiber. The specific physical properties of polyester and fibers are shown in Table 1.

[Example 2]

The addition amount of PEG8300 was 40wt%, and the addition amount of semi-hindered phenolic antioxidant CN1790 was 1.1wt%. The rest are the same as in Example 1. See Table 1 for details.

[Example 3]

The addition amount of PEG11000 (number average molecular weight 11000g/mol) was 35wt%, and the addition amount of semi-hindered phenolic antioxidant CN1790 was 1.0wt%. The rest are the same as in Example 1. See Table 1 for details.

[Example 4]

The addition amount of PEG20000 (number average molecular weight 20000g/mol) is 35wt%, and the addition amount of semi-hindered phenolic antioxidant CN1790 is 1.0wt%. The rest are the same as in Example 1. See Table 1 for details.

[Example 5]

The addition amount of PEG30000 (number average molecular weight 30000g/mol) is 35wt%, and the addition amount of semi-hindered phenolic antioxidant CN1790 is 1.0wt%. The rest are the same as in Example 1. See Table 1 for details.

[Example 6]

The addition amount of PEG8300 is 35wt%, and the addition amount of semi-hindered phenolic antioxidant CN1790 is 3.0wt%. The rest are the same as in Example 1. See Table 1 for details.

[Example 7]

The addition amount of PEG8300 was 35wt%, and the addition amount of semi-hindered phenolic antioxidant CN1790 was 5.0wt%. The rest are the same as in Example 1. See Table 1 for details.

[Example 8]

The addition amount of PEG8300 is 35wt%, the semi-hindered phenolic antioxidant, the semi-hindered phenolic antioxidant, 3,9-bis[1,1-dimethyl-2-[(3-tert-butyl-4-hydroxy-5 -Methylphenyl)propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane (AO80) was added in an amount of 1.6 wt%. The rest are the same as in Example 1. See Table 1 for details.

[Example 9]

The addition amount of PEG8300 was 35wt%, and the addition amount of semi-hindered phenolic antioxidant AO80 was 4.7wt%. The rest are the same as in Example 1. See Table 1 for details.

[Example 10]

The addition amount of PEG8300 was 35wt%, and the addition amount of semi-hindered phenolic antioxidant AO80 was 8.0wt%. The rest are the same as in Example 1. See Table 1 for details.

[Example 11]

The addition amount of PEG8300 is 30wt%, and the addition amount of semi-hindered phenolic antioxidant CN1790 is 1.0wt%. The rest are the same as in Example 1. See Table 1 for details.

[Example 12]

The addition amount of PEG8300 was 27wt%, and the addition amount of semi-hindered phenolic antioxidant CN1790 was 10.0wt%. The rest are the same as in Example 1. See Table 1 for details.

[Example 13]

-2,4,6-(1H,3H,5H)-三酮(CN1790)，攪拌10分鐘後向反應體系裡導入氮氣回至常壓，停止縮聚反應得到共聚酯。 Put 10.9Kg of terephthalic acid and 11.8Kg of 1,4-butanediol into the esterification kettle, add 450ppm of tetrabutyl titanate catalyst relative to the total amount of the final polyester, stir and heat up to 230°C for esterification reaction Move to the polycondensation kettle, add polyethylene glycol 3400 (polyethylene glycol with a number-average molecular weight of 3400 g/mol, abbreviated as PEG3400) of 45wt% relative to the final polyester total amount, add titanium relative to the final polyester total amount 900 ppm of tetrabutyl acid catalyst, and 250 ppm of stabilizer trimethyl phosphate relative to the total amount of the final polyester were added. After 5 minutes, the pressure was reduced and the temperature was raised. Semi-hindered phenolic antioxidant 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5 with a total polyester of 1.3 wt% -three

-2,4,6-(1H,3H,5H)-trione (CN1790), after stirring for 10 minutes, nitrogen was introduced into the reaction system to return to normal pressure, and the polycondensation reaction was stopped to obtain a copolyester.

The polyester chips obtained above were melt-spun at a spinning speed of 3 Km/min to obtain pre-oriented yarns. Then, the obtained pre-oriented yarn is subjected to false twisting processing. The processing conditions are as follows: the temperature of the first hot box is 180°C, the temperature of the second hot box is normal temperature, and the elongation ratio is 1.7 to obtain a highly hygroscopic polyester fiber. The specific physical properties of polyester and fibers are shown in Table 2.

[Example 14]

The addition amount of PEG3400 was 55wt%, and the addition amount of semi-hindered phenolic antioxidant CN1790 was 1.4wt%. The rest are the same as in Example 13. See Table 2 for details.

[Example 15]

The addition amount of PEG3400 was 58wt%, and the addition amount of semi-hindered phenolic antioxidant CN1790 was 1.8wt%. The rest are the same as in Example 13. See Table 2 for details.

[Example 16]

The addition amount of PEG11000 was 55wt%, and the addition amount of antioxidant CN1790 was 1.4wt%. The rest are the same as in Example 13. See Table 2 for details.

[Example 17]

The addition amount of PEG20000 was 55wt%, and the addition amount of semi-hindered phenolic antioxidant CN1790 was 1.4wt%. The rest are the same as in Example 13. See Table 2 for details.

[Example 18]

The addition amount of PEG3400 is 55wt%, the addition amount of semi-hindered phenolic antioxidant CN1790 is 4.2wt%, and the rest are the same as in Example 13. See Table 2 for details.

[Example 19]

The addition amount of PEG3400 was 55wt%, the addition amount of semi-hindered phenolic antioxidant CN1790 was 8.0wt%, and the rest were the same as in Example 13. See Table 2 for details.

[Example 20]

The addition amount of PEG3400 is 55wt%, the semi-hindered phenolic antioxidant 3,9-bis[1,1-dimethyl-2-[(3-tert-butyl-4-hydroxy-5-methylphenyl) The addition amount of propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane (AO80) was 2.2 wt%. The rest are the same as in Example 13. See Table 2 for details.

[Example 21]

The addition amount of PEG3400 was 55wt%, and the addition amount of semi-hindered phenolic antioxidant AO80 was 6.6wt%. The rest are the same as in Example 13. See Table 2 for details.

[Example 22]

The addition amount of PEG3400 was 55wt%, and the addition amount of semi-hindered phenolic antioxidant AO-80 was 8.0wt%. The rest are the same as in Example 13. See Table 2 for details.

[Example 23]

The addition amount of PEG3400 is 50wt%, and the addition amount of semi-hindered phenolic antioxidant CN1790 is 10.0wt%. The rest are the same as in Example 13. See Table 2 for details.

[Example 24]

-2,4,6-(1H,3H,5H)-三酮(CN1790)，攪拌10分鐘後向反應體系裡導入氮氣回至常壓，停止縮聚反應得到共聚酯。 10.9Kg of terephthalic acid and 4.7Kg of ethylene glycol were put into the esterification kettle, stirred and heated to 230° C. to carry out the esterification reaction, and then moved to the polycondensation kettle, and the polyethylene glycol of 35wt% relative to the total amount of the final polyester was added 8300 (polyethylene glycol with a number-average molecular weight of 8300 g/mol, abbreviated as PEG8300), with antimony trioxide having a content of 250 ppm relative to the total amount of the final polyester in terms of antimony element as a polymerization catalyst, and adding antimony trioxide relative to the total amount of the final polyester. The amount of stabilizer trimethyl phosphate was 250ppm, and after 5 minutes, the pressure was reduced and the temperature was raised. After reaching the final temperature of 285 ° C and the final pressure, 1.0 wt% of the semi-hindered phenolic antioxidant was added to the reaction system relative to the total amount of the final polyester. 1,3,5-Tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-tris

-2,4,6-(1H,3H,5H)-trione (CN1790), after stirring for 10 minutes, nitrogen was introduced into the reaction system to return to normal pressure, and the polycondensation reaction was stopped to obtain a copolyester.

The above polyester was used as the island component, and polyethylene terephthalate (IV=0.66) was used as the sea component. After vacuum drying at 150 ° C for 12 hours, the island component was 20wt% and the sea component was 80wt%. The mixing ratio is supplied to the screw type composite spinning machine for melting separately, and the spinning temperature is 285°C and the discharge rate is 36g/min. strip. The spun yarn is cooled under cold air with a wind temperature of 20°C and a wind speed of 20m/min, and is fed with oil by the oil feeder. The 2nd stage roller of the rotation speed was taken up to obtain an undrawn filament of 144dtex-36f. Then, the obtained undrawn yarn was drawn and false-twisted at a heater temperature of 170° C. and a magnification of 1.7 times using a draw-false-twist machine (twisting part: friction disk type, heater part: contact type) to obtain 84 dtex -36f false twisted silk.

Table 3 shows the evaluation results of the fiber properties, fabric properties, and processability of the obtained fibers. The number of times of yarn breakage during false twisting was 0, and the workability was extremely good. At the same time, the hygroscopicity was not substantially reduced after the hot water treatment, and the hygroscopicity was also good after the hot water treatment. And, but the leveling, quality have reached the qualified level. See Table 3 for details.

[Example 25]

The addition amount of the semi-hindered phenolic antioxidant CN1790 is 3.0 wt %, and the rest are the same as those in Example 24. See Table 3 for details.

[Example 26]

The addition amount of the semi-hindered phenolic antioxidant CN1790 was 5.0 wt %, and the rest were the same as those in Example 24. See Table 3 for details.

[Example 27]

The addition amount of PEG8300 is 45wt%, the addition amount of semi-hindered phenolic antioxidant CN1790 is 5.0wt%, and the rest are the same as in Example 24. See Table 3 for details.

[Example 28]

The addition amount of PEG8300 is 55 wt%, the addition amount of semi-hindered phenolic antioxidant CN1790 is 5.0 wt%, and the rest are the same as in Example 24. See Table 3 for details.

[Example 29]

The addition amount of the semi-hindered phenolic antioxidant AO80 was 1.6 wt %, and the rest were the same as those in Example 24. See Table 3 for details.

[Example 30]

The addition amount of the semi-hindered phenolic antioxidant AO80 is 4.7 wt %, and the rest are the same as those in Example 24. See Table 3 for details.

[Example 31]

The addition amount of the semi-hindered phenolic antioxidant AO80 is 8.0 wt%, and the rest are the same as those in Example 24. See Table 3 for details.

[Example 32]

The addition amount of the semi-hindered phenolic antioxidant CN1790 is 2.0 wt %, and the rest are the same as those in Example 24. See Table 3 for details.

[Example 33]

The addition amount of the semi-hindered phenolic antioxidant AO80 is 4.0 wt %, and the rest are the same as those in Example 24. See Table 3 for details.

[Example 34]

The addition amount of the semi-hindered phenolic antioxidant AO80 is 6.0 wt %, and the rest are the same as those in Example 24. See Table 3 for details.

[Example 35]

The addition amount of the semi-hindered phenolic antioxidant CN1790 is 9.0 wt%, and the rest are the same as those in Example 24. See Table 3 for details.

[Example 36]

The addition amount of the semi-hindered phenolic antioxidant CN1790 was 0.9 wt %, and the rest were the same as those in Example 24. See Table 3 for details.

[Example 37]

-2,4,6-(1H,3H,5H)-三酮(CN1790)，攪拌10分鐘後向反應體系裡導入氮氣回至常壓，停止縮聚反應得到共聚酯。其餘同實施例24。具體見表4。 Put 10.9Kg of terephthalic acid and 11.8Kg of 1,4-butanediol into the esterification kettle, add 450ppm of tetrabutyl titanate catalyst relative to the total amount of the final polyester, stir and heat up to 230°C for esterification reaction Move to the polycondensation kettle, add polyethylene glycol 8300 (polyethylene glycol with a number-average molecular weight of 8300 g/mol, abbreviated as PEG8300) that is 50 wt% relative to the final polyester total amount, and add titanium relative to the final polyester total amount. 900 ppm of tetrabutyl acid catalyst, and 250 ppm of stabilizer trimethyl phosphate relative to the total amount of the final polyester were added. After 5 minutes, the pressure was reduced and the temperature was raised. Semi-hindered phenolic antioxidant 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5 with a total polyester of 1.3 wt% -three

-2,4,6-(1H,3H,5H)-trione (CN1790), after stirring for 10 minutes, nitrogen was introduced into the reaction system to return to normal pressure, and the polycondensation reaction was stopped to obtain a copolyester. The rest are the same as in Example 24. See Table 4 for details.

[Example 38]

The addition amount of the semi-hindered phenolic antioxidant CN1790 is 2.4 wt %, and the rest are the same as those in Example 37. See Table 4 for details.

[Example 39]

The addition amount of the semi-hindered phenolic antioxidant CN1790 is 4.2wt%, and the rest are the same as in Example 37. See Table 4 for details.

[Example 40]

The addition amount of the semi-hindered phenolic antioxidant CN1790 is 8.0 wt %, and the rest are the same as those in Example 37. See Table 4 for details.

[Example 41]

The addition amount of the semi-hindered phenolic antioxidant AO80 was 2.2 wt%, and the rest were the same as those in Example 37. See Table 4 for details.

[Example 42]

The addition amount of the semi-hindered phenolic antioxidant AO80 is 6.6 wt %, and the rest are the same as those in Example 37. See Table 4 for details.

[Example 43]

The addition amount of PEG8300 is 45wt%, the addition amount of semi-hindered phenolic antioxidant AO80 is 6.6wt%, and the rest are the same as in Example 37. See Table 4 for details.

[Example 44]

The addition amount of PEG8300 is 55wt%, the addition amount of semi-hindered phenolic antioxidant AO80 is 6.6wt%, and the rest are the same as in Example 37. See Table 4 for details.

[Example 45]

The addition amount of PEG8300 is 50wt%, the addition amount of semi-hindered phenolic antioxidant AO80 is 8.0wt%, and the rest are the same as in Example 37. See Table 4 for details.

[Example 46]

The addition amount of PEG8300 is 50wt%, the addition amount of semi-hindered phenolic antioxidant CN1790 is 2.0wt%, and the rest are the same as in Example 37. See Table 4 for details.

[Example 47]

The addition amount of PEG8300 is 50wt%, the addition amount of semi-hindered phenolic antioxidant CN1790 is 3.0wt%, and the rest are the same as in Example 37. See Table 4 for details.

[Example 48]

The addition amount of PEG8300 is 50wt%, the addition amount of semi-hindered phenolic antioxidant CN1790 is 5.0wt%, and the rest are the same as in Example 37. See Table 4 for details.

[Example 49]

The addition amount of PEG8300 is 50wt%, the addition amount of semi-hindered phenolic antioxidant AO80 is 4.0wt%, and the rest are the same as in Example 37. See Table 4 for details.

[Example 50]

The addition amount of PEG8300 is 50wt%, the addition amount of semi-hindered phenolic antioxidant AO80 is 6.0wt%, and the rest are the same as in Example 37. See Table 4 for details.

[Example 51]

The addition amount of PEG8300 is 50wt%, the addition amount of semi-hindered phenolic antioxidant CN1790 is 9.0wt%, and the rest are the same as in Example 37. See Table 4 for details.

[Comparative Example 1]

The addition amount of PEG8300 is 12wt%, the addition amount of semi-hindered phenolic antioxidant CN1790 is 1.0wt%, and the rest are the same as in Example 1. See Table 5 for details. Due to the relatively small amount of PEG added, the effect of high hygroscopicity cannot be achieved.

[Comparative Example 2]

The addition amount of PEG8300 is 20wt%, the addition amount of semi-hindered phenolic antioxidant CN1790 is 1.0wt%, and the rest are the same as in Example 1. See Table 5 for details. Due to the relatively small amount of PEG added, the effect of high hygroscopicity cannot be achieved.

[Comparative Example 3]

The addition of PEG100000 (number-average molecular weight 100000g/mol) is 30wt%, and the addition of semi-hindered phenolic antioxidant CN1790 is 2.0wt%, and all the other are the same as in Example 1. See Table 5 for details. Due to the addition of ultra-high molecular weight PEG, spit swelling occurs, and it is difficult to spit out.

[Comparative Example 4]

The addition amount of PEG3400 was 12 wt %, the addition amount of semi-hindered phenolic antioxidant CN1790 was 0.8 wt %, and the rest were the same as in Example 13. See Table 5 for details. Due to the relatively small amount of PEG added, the effect of high hygroscopicity cannot be achieved.

[Comparative Example 5]

The addition amount of PEG3400 is 70wt%, the addition amount of semi-hindered phenolic antioxidant CN1790 is 4.6wt%, and the rest are the same as in Example 13. See Table 5 for details. If the amount of PEG3400 added is too high, the extrapolated melting starting temperature of the final polyester is low. After the polyester is formed into fibers, the occurrence of broken filaments and hairiness increases, and the processability becomes poor. When forming fiber structures such as fabrics and knitting Dyed spots and hairiness increased, and the quality was poor.

[Comparative Example 6]

The addition amount of PEG600 (number-average molecular weight 600 g/mol) is 50 wt %, the addition amount of semi-hindered phenolic antioxidant CN1790 is 3.3 wt %, and the rest are the same as in Example 13. See Table 5 for details. The molecular weight of PEG is relatively low, and a large amount of PEG is scattered during the polymerization process. Even if a large amount of PEG is added, the obtained polyester has poor hygroscopicity.

[Comparative Example 7]

The addition amount of PEG100000 is 50wt%, the addition amount of semi-hindered phenolic antioxidant CN1790 is 3.3wt%, and the rest are the same as in Example 13. See Table 5 for details. Due to the addition of ultra-high molecular weight PEG, spit swelling occurs, and it is difficult to spit out.

[Comparative Example 8]

The addition amount of PEG3400 is 20wt%, the addition amount of semi-hindered phenolic antioxidant CN1790 is 1.0wt%, and the rest are the same as in Example 13. See Table 5 for details. Due to the relatively small amount of PEG added, the effect of high hygroscopicity cannot be achieved.

[Comparative Example 9]

The addition amount of PEG8300 is 20wt%, the addition amount of hindered phenolic antioxidant...(IR1010) is 0.5wt%, and the rest are the same as in Example 1. See Table 5 for details. Compared with hindered phenolic antioxidants, hindered phenolic antioxidants tend to cause polyester yellowing. In the case of a small amount of PEG, although only a small amount of hindered phenolic antioxidant tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] neopentaerythritol ester IR1010 , the yellowing index of polyester is also within the acceptable range, but the antioxidant effect of polyester is reduced, and the difference between the difference in moisture absorption rate of polyester fiber before and after dyeing is large, indicating that the moisture absorption of polyester fiber after dyeing is significantly reduced .

[Comparative Example 10]

The addition amount of PEG8300 is 50wt%, the addition amount of hindered phenolic antioxidant IR1010 is 3.0wt%, and the rest are the same as in Example 1. See Table 5 for details. When a large amount of hindered phenolic antioxidant is added, although the antioxidant effect is excellent, the fiber tends to be yellowed.

[Comparative Example 11]

The addition amount of PEG8300 is 50wt%, the addition amount of hindered phenolic antioxidant IR1010 is 0.5wt%, and the rest are the same as in Example 1. See Table 5 for details. When a hindered phenolic antioxidant is added in a small amount, the yellowing of fibers can be suppressed, but the antioxidant effect is reduced.

[Comparative Example 12]

The addition amount of PEG3400 is 20wt%, the addition amount of hindered phenolic antioxidant IR1010 is 0.5wt%, and the rest are the same as Example 13. See Table 5 for details. Compared with hindered phenolic antioxidants, hindered phenolic antioxidants tend to cause polyester yellowing. In the case of a small amount of PEG added, although only a small amount of hindered phenolic antioxidant IR1010 needs to be added, the yellowing index of polyester is also within the acceptable range, but the antioxidant effect of polyester is reduced, and the polyester fiber before and after dyeing. The difference of the difference in the moisture absorption rate is large, indicating that the moisture absorption of the polyester fiber after dyeing is significantly reduced.

[Comparative Example 13]

The addition amount of PEG3400 is 50wt%, the addition amount of hindered phenolic antioxidant IR1010 is 3.0wt%, and the rest are the same as Example 13. See Table 5 for details. When a large amount of hindered phenolic antioxidant is added, although the antioxidant effect is excellent, the fiber tends to be yellowed.

[Comparative Example 14]

The addition amount of PEG3400 is 50wt%, the addition amount of hindered phenolic antioxidant IR1010 is 0.5wt%, and the rest are the same as in Example 13. See Table 5 for details. When the hindered phenolic antioxidant is added in a small amount, the yellowing of the fiber can be suppressed, but the antioxidant effect is reduced.

[Example 15]

The addition amount of PEG8300 is 22wt%, the addition amount of semi-hindered phenolic antioxidant CN1790 is 1.0wt%, and the rest are the same as in Example 1. See Table 5 for details. The amount of PEG8300 added was inappropriate, resulting in poor discharge properties.

[Example 16]

The addition amount of PEG8300 is 25wt%, the addition amount of semi-hindered phenolic antioxidant CN1790 is 1.0wt%, and the rest are the same as in Example 1. See Table 5 for details. The amount of PEG8300 added was inappropriate, resulting in poor discharge properties.

[Comparative Example 17]

The addition of PEG8300 is 50wt%, the addition of hindered phenolic antioxidant IR1010 is 3.0wt%, and the rest are the same as in Example 24. See Table 6 for details. In the case of composite spinning, when a large amount of hindered phenolic antioxidant is added, although the antioxidant effect is excellent, the fiber tends to be yellowed.

[Comparative Example 18]

The addition amount of PEG8300 is 50wt%, the addition amount of hindered phenolic antioxidant IR1010 is 0.8wt%, and the rest are the same as in Example 24. See Table 6 for details. In the case of composite spinning, when a small amount of hindered phenolic antioxidant is added, the yellowing of the fiber can be suppressed, but the antioxidant effect is reduced.

[Comparative Example 19]

The addition amount of PEG8300 is 50wt%, and no antioxidant is added, and the rest are the same as in Example 24. See Table 6 for details. Since no antioxidants are added, the fiber does not yellow, but it does not have an antioxidant effect.

Claims (5)

A polyester is characterized in that: the polyester is a polymer formed of aromatic dicarboxylic acid or its derivative and aliphatic diol as main constituents, and polyethylene glycol as a copolymerization constituent, wherein poly The number average molecular weight of ethylene glycol is 2000~30000g/mol, the copolymerization rate is 25~55wt%, and the polyester contains a semi-hindered phenolic antioxidant as shown in formula 1,

Wherein, R1 is a group formed by the combination of one or more of hydrocarbon, oxygen and nitrogen; R2 is a group formed by the combination of one or more of hydrogen, hydrocarbon, oxygen and nitrogen; the semi-hindered phenols The content of antioxidants accounts for 2.35wt%~8.0wt% of the total weight of polyester. The polyester of claim 1, wherein the semi-hindered phenolic antioxidant is the antioxidant 3,9-bis[1,1-dimethyl-2-[(3-tert-butylene shown in formula 2 yl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, or 1, as shown in formula 3, 3,5-Tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-tris

-2,4,6-(1H,3H,5H)-trione,

The polyester of claim 1, wherein the copolymerization rate of the polyethylene glycol is 35-55 wt%. The polyester of claim 3, wherein the aliphatic diol is ethylene glycol, and the number average molecular weight of the polyethylene glycol is 4000-30000 g/mol. The polyester of claim 3, wherein the aliphatic diol is 1,4-butanediol.