KR100558688B1 - An excellent form-stability polyester copolymer, and its polyester filament - Google Patents

Abstract

The present invention relates to a polyester copolymer and a polyester filament thereof in which an ethylene terephthalate repeating unit is copolymerized with a hydrocarbylenedioxy repeating unit alone or together with a hydrocarbylenedicarbonyl repeating unit.

The polyester copolymer of this invention has a glass transition temperature of 65 degrees C or less, and melting | fusing point is 240 degreeC or more. The polyester filament of the present invention is capable of atmospheric dyeing with disperse dyes, and has excellent form stability and is mainly used as a yarn for clothes.

Polyester copolymer, polyester filament, ethylene terephthalate, hydrocarbylenedioxy, hydrocarbylenedicarbonyl, polyethylene glycol, form stability

Description

An excellent form-stability polyester copolymer, and its polyester filament             

The present invention can be dyed at a low temperature of 100 ℃ or less without the carrier, and can be dyed at a low temperature of less than 100 ℃, good fastness and radiation stability in addition to the dyeability, in particular, the shape stability of the yarn is excellent soft touch without the need for high temperature heat treatment to prevent shrinkage It relates to a polyester copolymer capable of obtaining and a filament thereof.

Conventional polyester polyester fibers are 100% polyethylene terephthalate with a glass transition temperature (Tg) of about 80 ° C., and can be dyed at a high temperature of about 130 ° C. without a carrier. Polyester is difficult to penetrate the dye due to its structural crystal structure, and dyeing is possible at a temperature above the glass transition temperature (Tg), but the dyeing speed is very slow, it takes about several days or weeks at 85 ℃.

The technique developed to solve this problem is high temperature dyeing. This method is now industrialized because the dye diffusion speed is increased at high temperature (about 130 ° C.) and the dyeing time can be completed within about 1 hour.

If the existing polyester yarn is mixed with natural fibers (cotton, wool) and regenerated fibers (rayon, acetate), the dyeing temperature of the polyester is high, causing problems such as a decrease in strength and dying of natural or regenerated fibers.

When polyester yarn is mixed with cotton, cellulose fiber, wool, and spandex, polyester needs to be dyed at 130 ℃ or higher, but the direct dye used for dyeing other mixed fibers is 100 ~ 110 ℃ and the reaction dye is below 95 ℃. There is no thermal decomposition of the dye to dye, wool is dyed at a temperature of more than 100 ℃ damage the fiber, spandex is reduced elastic recovery rate and strength. Therefore, there has been a demand for developing a polyester yarn capable of atmospheric dyeing at 100 ° C or lower.

As a conventional technique for producing a polyester capable of atmospheric dyeing, Japanese Patent Application Laid-Open No. 53-78383, Japanese Patent Application No. 53-78384, Japanese Patent Application 57-45646, Japanese Patent Application No. 63-235536, Japanese Patent Application No. 4-41716, etc. A method of improving the dyeability without reducing the melting point by block copolymerization of glycol has been proposed.

JP 57-25646 proposes a polyester fiber in which dyeing properties are modified by copolymerizing polyethylene glycol (PEG) having an average molecular weight of 300 to 4000 by 2 to 10% by weight. Japanese Patent Laid-Open No. 4-41716 proposes a polyester atmospheric salted yarn obtained by copolymerizing 6 to 10% by weight of polyethylene glycol having an average molecular weight of 500 to 3000. According to the example, the average molecular weight of PEG is 1000, and a copolymerization rate is 8 weight%. This known fiber was developed for the purpose of mixing with wool, and achieves 98 ° C salting.

However, it is insufficient for dyeing of the reaction dye used for dyeing cellulose fibers (below 95 ° C) by 98 ° C salting. In addition, the dyeing temperature of the atmospheric pressure jigs used in the atmospheric dyeing machine is less than 95 ℃, more preferably around 90 ℃. That is, at 98 degreeC, dyeing may be difficult depending on a deep color or dye and color.

In addition, when the copolymerization ratio is increased by copolymerizing polyethylene glycol alone as in Japanese Patent Laid-Open No. 4-41716, the dyeability is improved, but the radiation stability is deteriorated, and the light fastness and the wash fastness are poor.

In particular, due to the poor heat resistance of polyethylene glycol during copolymerization, the radiation stability is deteriorated due to the addition of a large amount of antioxidants and antifoaming agents other than Dolby prevention, the contamination of the spinneret is severe and there is a problem that the cleaning cycle is greatly shortened.

Japanese Patent Application Laid-Open No. 9-324322 proposes a polyester atmospheric salt yarn copolymerized with polyethylene glycol having an average molecular weight of 500 to 4000 in a range of 1.5 to 4.5% by weight, and 9 to 6% by weight of adipic acid. According to the embodiment, the average molecular weight was copolymerized with 4% by weight of PEG and 7% by weight of adipic acid.

However, while the PEG content is reduced, the total copolymer content is rather increased due to an increase in the content of replaced adipic acid. The copolymerized adipic acid lowers the yarn strength and the heat resistance and the fastness of the copolyester. In addition, a large amount of adipic acid lowers the crystallinity of the fiber, lowers the melting point, and greatly increases the heat shrinkage of the yarn, resulting in poor shape stability.

Thus, knitted fabrics made from these yarns require high temperature treatment to provide sufficient thermal dimensional stability before or after dyeing, resulting in a stiff hand feel of the fabric.

The present invention solves the problems of the prior art described above, and can be dyed at atmospheric pressure, and excellent in form stability, and thus can be omitted at a high temperature during the post-processing, to provide a polyester copolymer and a yarn of which the touch is improved. .

In another aspect, the present invention is to provide a polyester filament having a low shrinkage and low heat shrink stress by relaxing the internal stress of the polymer.

The present invention relates to a polyester copolymer having excellent shape stability and a polyester filament thereof.

More specifically, the present invention provides (i) 85 to 99% by weight of ethylene terephthalate repeating units of the following general formula (I) and (ii) hydrocarbylenedioxy repeating units of the following general formula (II) alone or the following general formula ( Hydrocarbylenedioxy repeating units of II) and 1 to 15% by weight of one or more hydrocarbylenedicarbonyl repeating units selected from the following general formulas (III) to (V) are copolymerized, and the glass transition temperature is 65 It relates to a polyester copolymer having a melting point of 240 ° C or higher and lower than or equal to ° C.

                           - doing -

The present invention also relates to a polyester filament composed of the polyester copolymer and having the following physical properties.

                            -Below-

                Cutting elongation: 25 ~ 45%

                Strength at 7% elongation: 1.5g / d or more

                Maximum heat shrinkage stress: 0.2g / d or less

                Non-shrinkage rate: 12% or less

Hereinafter, the present invention will be described in detail.

First, in the polyester copolymer of the present invention, the ethylene terephthalate repeating unit and the hydrocarbylenedioxy repeating unit of the general formula (I) are copolymerized, or a hydrocarbylenedioxy repeating unit and a hydrocarbylenedicarbonyl repeating The unit is copolymerized.

구조와는 상이한 상기 일반식(Ⅱ)의 구조를 갖는다. 상기 히드로카르볼렌디카르보닐 반복단위는

구조와는 상이한 구조를 갖는한 어떠한 구조라도 무방하다. 바람직하기로는 상기 일반식(Ⅲ)~일반식(Ⅴ)의 구조중 1개인 것이 좋다.The hydrocarbylenedioxy repeating unit is

It has a structure of the said general formula (II) different from a structure. The hydrocarbylenedicarbonyl repeat unit is

Any structure may be used as long as it has a structure different from the structure. Preferably, one of the structures of the general formulas (III) to (V) is preferable.

The ethylene terephthalate repeating unit of formula (I) is prepared by polymerizing ethylene glycol (EG) and terephthalic acid (TPA) or dimethyl terephthalic acid (DMT). The hydrocarbylenedioxy repeating unit of formula (II) is copolymerized by adding polyethylene glycol (PEG) during the polyester polymerization.

Among the aliphatic diols, PEG is a very effective compound capable of atmospheric pressure salt even if the polyester copolymerization rate is lowered. As for PEG molecular weight used for superposition | polymerization, 500-4000 are suitable, More preferably, 1000-2000 are suitable. If the molecular weight is less than 500, a part of the PEG added at the time of polymerization is scattered under the reaction conditions of high temperature and pressure reduction, so that the copolymerization ratio is uneven, and the elongation and shrinkage ratio of the obtained fiber become uneven. In addition, in order to improve the dyeability by copolymerizing low molecular weight PEG, the number of moles of copolymerization increases, thereby lowering the softening point and melting point of the obtained polymer, thereby degrading the shape stability. When the molecular weight exceeds 4000, the high molecular weight PEG that is not copolymerized due to poor reactivity increases, and dyes are bleed-out during heat treatment before and after dyeing, thereby decreasing dyeability and color fastness.

The copolymerization content of the hydrocarbylenedioxy repeating unit is preferably 1 to 15% by weight. When copolymerizing with a hydrocarbylenedicarbonyl repeating unit, it is preferable that it is 5-9 weight% or more, and when copolymerizing a hydrocarbylenedioxy repeating unit alone, it is preferable that copolymerization content is 9-15 weight%. . When copolymerized with hydrocarbylenedicarbonyl repeating units, copolymerization content of less than 5% by weight may result in poor dyeability due to lack of dyeability, and when copolymerization content of more than 9% by weight, dyeability is good but strength decreases and color fastness. And radiation stability may deteriorate. In addition, the high temperature heat treatment may cause a disadvantage that the stiffness of the touch due to heat curing phenomenon.

In order to obtain atmospheric dyeing by copolymerizing hydrocarbylenedioxy repeating units alone, a copolymerization content of 9 to 15% by weight is preferable. 9 wt% or more is required to dye at a temperature of 95 ° C. or lower, but as the content thereof increases, polymerization and spinning stability decrease and production becomes difficult.

In addition, as their content increases, unreacted PEG also increases, and PEG is easily hydrophilic, causing process problems. Therefore, it is practical to improve dyeing and spinning stability and yarn strength by copolymerizing other repeating units having good fastness instead of increasing hydrocarbylenedioxy repeating units.

The present invention copolymerizes a hydrocarbylenedicarbonyl repeating unit such as General Formulas (III) to (V) as a secondary component to polyester for this purpose. The hydrocarbylenedicarbonyl repeating unit is copolymerized by adding an aliphatic dicarboxylic acid or aromatic dicarboxylic acid such as adipic acid, sebacic acid or isophthalic acid during polyester polymerization.

Copolymerization of only the hydrocarbylenedicarbonyl repeating unit reduces the Tg reduction effect, scatters the polyester crystal structure, greatly lowers the softening point and melting point, resulting in poor shape stability. Therefore, the hydrogarbolenedicarbonyl repeating unit needs to be used in a limited way to improve the dyeing property of the polymer, and to suppress degradation of the fastness and the radiation stability while maintaining the heat resistance and the fiber strength.

The hydrocarbylene dicarbonyl repeating unit can obtain a synergistic effect of dyeability while suppressing a decrease in fastness when the hydrocarbylene dioxy content is added at a content of 6% by weight or more. The copolymerization content of the hydrocarbylenedicarbonyl repeating unit is preferably 0 to 4% by weight. When the copolymerization content exceeds 4% by weight, the lowering of the melting point of the polymer and the increase in shrinkage rate are noticeable, and side effects occur. It is preferable to improve the fastness and radiation stability to make the total copolymerization content of the hydrocarbylenedioxy repeating unit and the hydrocarbylenedicarbonyl repeating unit less than 10% by weight.

The polyester copolymer of the present invention has a glass transition temperature (Tg) of 65 ° C. or lower and a melting point of 240 ° C. or higher. If the melting point (Tm) of the polymer is less than 240 ° C., the dyeability is good, but the fastness and shape stability are poor, and the yarn strength is insufficient, which makes it less practical. If the yarn shrinkage is high, high temperature heat treatment is required before and after dyeing for morphological stability, in which case the fabric feels stiff. If the glass transition temperature (Tg) is higher than 65 ° C., dyeing speed and dye adsorption rate decrease at normal pressure (100 ° C. or lower), making dark color difficult.

The polyester copolymer is radially stretched to produce a filament yarn. In the present invention, it is preferable to use a direct spin-drawing method (Direct-Spin-Drawing) to improve the shape stability of the filament yarn. This method is very effective because it can reduce the heat shrinkage of yarns by relieving non-governmental orientation.

The cutting elongation of the polyester filament of the present invention is 25 ~ 45%, less than 25%, the elongation at the time of weaving is increased, the quality is worsened by the occurrence of the shear by the single-cutting yarn, and if it exceeds 45%, the tensile elongation in the post-process The thread is stretched and the process passability is bad. In addition, the strength at 7% elongation is 1.5 g / d or more. If the strength at 7% elongation is less than 1.5 g / d, the strength is low, making it unsuitable for garment yarn.

The polyester filament of the present invention has a maximum heat shrinkage stress of 0.2 g / d or less. If the maximum heat shrinkage stress exceeds 0.2g / d, the shrinkage occurs in the heat treatment and dyeing process so that the fabric thickness increases, and if the heat treatment is performed before or after dyeing to prevent shrinkage, the fabric feels stiff. There is a downside to termination. The non-shrinkage rate of the polyester filament of this invention is 12% or less, Preferably it is 6-10%.

In the present invention, various physical properties of the copolymer and the yarn are evaluated as follows.

Maximum heat shrinkage stress (g / d)

Heat shrinkage stress tester (model KE-2) manufactured by Kanebo Engineering, Japan, is used to measure the shrinkage stress at the temperature at which the highest shrinkage stress occurs.

Non-shrinkage rate (%)

After measuring the length (L0) and the length (L1) after immersion, the sample (yarn) is immersed in boiling water (non-water) for 30 minutes.

× 100Non-shrinkage rate (%) =

× 100

Strength at 7% elongation

It measures by the JIS L-1017 method.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited only to the following examples.

Example 1

1000 parts of terephthalic acid and 420 parts of ethylene glycol were added to the esterification reaction tube at 240 ° C to 250 ° C, and the reaction was transferred to a polymerization tube. 85 parts (7.5 weight%) of polyethyleneglycols of an average molecular weight 1000, 0.4 part of antimony trioxide, 0.5 part of titanium dioxides, 0.3 part of phosphoric acid, 3 parts of sulfates, 0.4 part of cobalt acetates, and 0.1 part of antifoamers are added, followed by stirring. The temperature of the polymerization tube was gradually increased from 250 ° C to 280 ° C, and the pressure was reduced gradually to continue the polymerization while reducing the pressure to 1 Torr or less to prepare a polyester copolymer. The polyester copolymer is spun by direct spinning at a spinning temperature of 285 ° C. to prepare a polyester yarn of 75 denier / 36 filaments. The results of evaluating the physical properties of the prepared polyester copolymer and yarn are shown in Table 2.

Example 2-Example 3 and Comparative Example 1

A polyester copolymer and a yarn were prepared in the same process and conditions as in Example 1 except that the composition ratio of the polyester copolymer was changed as in Table 1. The results of evaluating the physical properties of the prepared polyester copolymer and yarn are shown in Table 2.

Copolymerization conditions division Copolymer Composition (wt%) Polyethylene terephthalate Polyethylene glycol Isophthalic acid Example 1 92.5 7.5 0 Example 2 94.0 6 0 Example 3 91.0 7 2 Comparative Example 1 92.0 0 8

Copolymer and Yarn Properties division Example 1 Example 2 Example 3 Comparative Example 1   Glass transition temperature (℃) 60 65 58 76   Melting temperature (℃) 249 251 246 235   Elongation at break (%) 35 37 38 18   7% new town strength (g / d) 2.1 2.0 2.2 2.3   Heat shrinkage stress (g / d) 0.19 0.18 0.19 2.2   Non-shrinkage rate (%) 9 8 9 11   Dyeability Good Good Good Bad

The polyester copolymer of the present invention and its yarn can be dyed under atmospheric pressure and can be mixed with natural or regenerated fibers. In addition, the internal stress of the polymer is alleviated, resulting in low heat shrinkage stress and excellent shape stability. As a result, it is possible to omit the high temperature treatment in the post process so that the touch can be prevented from deteriorating.

Claims (5)

(Iii) 85 to 99% by weight of ethylene terephthalate repeating units of the following general formula (I) and (ii) hydrocarbylenedioxy repeating units of the following general formula (II) or hydrocarbylene of the following general formula (II) 1 to 15% by weight of the deoxy repeating unit and at least one hydrocarbylenedicarbonyl repeating unit selected from the following general formulas (III) to (V) are copolymerized, the glass transition temperature is 65 ° C or lower, and the melting point is 240 Polyester copolymer which is C or more.                            - doing -

In said general formula (II), n is an integer of 10-100. The polyester copolymer according to claim 1, wherein the copolymer content of the hydrocarbolenedioxy repeating unit is 5 to 9% by weight. The polyester copolymer according to claim 1, wherein the copolymer content of the hydrocarbylenedicarbonyl repeating unit is 0 to 4% by weight. The polyester copolymer according to claim 1, wherein the total copolymerization content of the hydrocarbylenedioxy repeating unit and the hydrocarbylenedicarbonyl repeating unit is 1 to 10% by weight. A polyester filament composed of the polyester copolymer of claim 1 having the following physical properties.                             -Below-                 Cutting elongation: 25 ~ 45%                 Strength at 7% elongation: 1.5g / d or more                 Maximum heat shrinkage stress: 0.2g / d or less                 Non-shrinkage rate: 12% or less