KR20000008130A - Preparation method of copolymer for polyester elastic yarn - Google Patents

Abstract

PURPOSE: Preparation method of copolymer by post-polymerizing polyetherester blockcopolymer having intrinsic viscosity of below 1.75 at 120-180°C under the degree of vacuum pressure of 0.1-0.5 torr is provided to improve strength of fiber and elastic performance. CONSTITUTION: The process comprises a process for increasing viscosity by post-polymerization of high viscosity polyetherester blockcopolymer having intrinsic viscosity of below 1.75 at 120-180°C under the degree of vacuum pressure of 0.1-0.5 torr. For an example, 3,900g of dimethylterephthalic acid and about 15 mole of polyoxybutyleneglycol, and 1,4-butanediol are reacted with 0.2 mass% of metal salt or titan compound as a catalyst at 210°C in a reactor with a distillation condenser to give an esterification product, which is heated to 230°C, added with 0.12 mass% of titan compound, and reacted for 7 hr under the degree of vacuum pressure of below 0.5 torr to give a polyetherester block copolymer, which is post-polymerized at above 150°C for 24 hr under the degree of vacuum pressure of 0.1-0.5 torr, and melt-spun to give a final product. The product shows a good strength, elastic recovery percentage of elongation and elongation.

Description

Manufacturing method of polyester elastic use copolymer

The present invention relates to a method for producing a polyether ester block copolymer having excellent strength, elasticity and dyeing property. In particular, the polyether ester block copolymer having an intrinsic viscosity of 1.75 or less, prepared by melt polymerization, is heated in a vacuum to have an intrinsic viscosity of 1.8 to 2.2. The present invention relates to a method for preparing a polyester-based elastomeric use copolymer prepared from a polyetherester block copolymer of the range to improve the strength, elastic performance and dyeability of elastic yarn.

As is well known, the polyether ester block copolymer is a copolymer in which polyether soft segments and polyester hard segments are irregularly arranged in a molecular chain, and is mainly used in swimwear or sports clothing requiring such elastic force performance. have.

In recent years, polyether ester block copolymer elastomers are made of fibers, and their use has been gradually expanded to stretch garments and the like.

In addition, the elastic recovery rate is less than polyurethane, but exhibits relatively good elastic properties under low elongation and enables melt spinning.

On the other hand, the characteristic of the polyurethane is that the hard chains are connected by chemical bonds called hydrogen bonds, which makes the structure very strong and difficult to break. On the other hand, the elastic yarn made from the polyether ester block copolymer is different from the polyurethane. Otherwise, since molecular chains are connected by physical bonds, such as crystallization of hard segments, the attraction between the molecular chains is small and the crystal regions are destroyed by external forces, so that permanent deformation is likely to occur, and thus the elastic force performance is not good.

In order to improve this disadvantage, a method of improving the performance of elastic yarns by increasing the crystallinity by blending a crystal nucleating agent as a polymerization additive is disclosed in Japanese Patent Laid-Open Nos. 59-45349 and 59-45350. There is a disadvantage that the performance is insufficient to use as an elastic yarn because it can not be greatly improved.

In addition, a method of improving the crystallinity of a hard segment to improve elastic properties by blending a high melting point polybutylene terephthalate during spinning is disclosed in Japanese Patent Laid-Open No. 58-141236, but this method also lacks crystal coagulation power. Therefore, the improvement effect of the elastic properties is small, and there is a disadvantage that the performance is insufficient to use as an elastic yarn.

In addition, Japanese Patent Application Laid-Open No. 57-56513 discloses a method of increasing the elastic recovery rate by blending polypropylene during spinning to shorten the initial elastic modulus. However, this method also has insufficient physical properties to be used as an elastic yarn due to its small improvement in elastic properties. There is one disadvantage.

In addition, a method of improving the elastic performance by reducing the permanent deformation by blending a specific metal sulfonate salt as an additive during polymerization is disclosed in Japanese Patent Application Laid-Open No. 2-117949, but this method also has insufficient dyeability by ion dyes. Disperse dyes can be dyed, but wash fastness and light fastness have a disadvantage in that it is insufficient to use as an elastic yarn.

Therefore, the present invention is a polyether ester block copolymer having an intrinsic viscosity of 1.75 or less prepared by melt polymerization in a vacuum to prepare a polyether ester block copolymer having an intrinsic viscosity of 1.8 to 2.2 to the strength, elastic performance and dyeability of the elastic yarn It is an object of the present invention to provide a method for preparing a polyester-based elastomer use copolymer to improve the efficiency of the copolymer.

In order to achieve the above object, the present invention provides a polyether ester block copolymer having an intrinsic viscosity of 1.75 or less, prepared by melt polymerization in order to improve the strength and elastic performance of fibers during melt spinning. It is characterized in that the viscosity is increased by using a postcondensation polymerization method which proceeds at 120-180 degreeC.

Hereinafter, an embodiment of the present invention will be described in detail.

In the present invention, the polyester portion constituting the hard segment of the polyether ester block copolymer, which is a basic material of the elastic yarn, mainly uses polybutylene terephthalate synthesized from a terephthalic acid component and a butylene glycol component.

As a method of preparing the polyether ester block copolymer, a conventional method is used, but terephthalic acid, terephthalic acid dimethyl, butylene glycol and polyoxybutylene glycol are heated at 160 to 250 ° C. or a butylene terephthalate is synthesized in advance. And a method of heating and reacting the polyoxybutylene glycol at 210 to 250 ° C. may also be employed.

In this case, arbitrary catalysts, stabilizers, ultraviolet absorbers, midpoints, colorants, and various other improving agents may be optionally used as necessary.

In this case, lithium acetate hydrate, manganese acetate hydrate, magnesium acetate hydrate, calcium acetate hydrate, zinc acetate hydrate, and titanium compound may be used at about 0.05 to 0.15 mass% based on the polyether ester block copolymer.

The polyether ester block copolymer having an intrinsic viscosity of 1.75 or less uses a post-condensation polymerization method such as solid phase polymerization of a high viscosity polyether ester block copolymer in a vacuum dryer to improve the strength, elastic performance, and dyeability of elastic yarn. .

The solid phase polymerization carried out at this time is carried out in a temperature range of 120 to 180 ° C. at a vacuum degree of 0.05 to 5 Torr.

The present invention is described in more detail as follows.

3,900 g of dimethyl terephthalic acid, about 15 mol% of polyoxybutylene glycol and 1,4-butanediol were added to a reactor equipped with a stirrer, a distillation capacitor and a thermometer so that the G value was 1.1 to 1.3. Using a titanium compound as a catalyst, 0.12% by mass was added to carry out the transesterification reaction.

The end point of the exchange reaction was determined by the amount of methanol leaked out, and the transesterification reaction was terminated after evaluating the actual amount of methanol released as the reaction proceeded.

At this time, the reaction rate in the transesterification reaction was maintained at 99 ± 2% level.

After raising the esterified product at 230 ° C., 0.12% by mass of a titanium compound was added and reacted under low vacuum of 0.5 Torr or less for 7 hours to prepare a polyether ester block copolymer.

The polyether ester block copolymer thus obtained was subjected to postcondensation polymerization in a vacuum drier of 0.1 to 0.5 Torr or less for 24 hours at 150 ° C. or higher, followed by melt spinning to measure elastic performance.

The elastic performance measured here was measured for strength, elongation and elastic recovery rate using Instron.

The elastic recovery rate was calculated as the recovered length after 200% elongation of the elastic yarn of a certain length.

(Example 1)

3,900 g of dimethyl terephthalic acid, about 15 mol% of polyoxybutylene glycol, and 1,4-butanediol were mixed with a stirrer, a distillation capacitor, and a thermometer so that the G value was 1.1 to 1.3. About 0.12 mass% was added and a transesterification reaction was carried out at 210 ° C.

The end point of the transesterification reaction is determined by the amount of methanol leaked out.

At this time, the reaction rate in the transesterification reaction was maintained at 99 ± 2% level.

After raising the esterified product at 230 ° C., 0.12% by mass of a titanium compound was added and reacted under low vacuum of 0.5 Torr or less for 7 hours to prepare a polyether ester block copolymer.

The polyether ester block copolymer obtained as described above was postcondensation polymerized in a vacuum drier of 0.1 to 0.5 Torr or less for 24 hours at 150 ° C. or higher, followed by melt spinning to measure elastic performance.

The elastic performance measured here was measured for strength, elongation and elastic recovery rate using Instron.

The elastic recovery rate is shown in Table 1 below when the characteristics of the polyester elastic use copolymer obtained by calculating the recovered length after stretching the elastic yarn of a certain length by 200%.

(Example 2)

The same conditions as in Example 1 were carried out except that postcondensation polymerization was carried out in a vacuum dryer of 0.1 to 0.5 Torr or less for 14 hours at 140 ° C. and melt-spun to measure the elastic performance. It is as Table 1 when shown.

(Example 3)

The same conditions as in Example 1 were obtained except that after the condensation polymerization was carried out in a vacuum drier of 0.5 to 2 Torr or less for 15 hours at 150 ° C. and melt-spun, the elastic performance was measured. Table 1 is as follows.

Comparative example

As in Example 1, the same conditions as in Example 1 were obtained except that the elastic performance was measured by melt spinning without performing postcondensation polymerization in a vacuum drier of 0.1 to 0.5 Torr or less at 150 ° C. for 24 hours. It is as Table 1 when shown.

Table 1

division Strength (g / d) Elastic recovery rate (%) Elongation (%) Example 1 Very good good good Example 2 Very good usually good Example 3 good usually good Comparative Example usually usually good

As described above, in the present invention, an elastic yarn is prepared by preparing a polyether ester block copolymer having an intrinsic viscosity of 1.75 or less produced by melt polymerization in a polyether ester block copolymer having an intrinsic viscosity enhanced to a range of 1.8 to 2.2 by a postcondensation polymerization method. It has the effect of improving the strength, elastic performance and dyeability.

Claims (1)

In order to improve the strength and elastic performance of fibers during melt spinning, polyether ester block copolymers having an intrinsic viscosity of 1.75 or less, prepared by melt polymerization, have a vacuum of 0.1 to 0.5 torr and a polymerization temperature of 120 to 180 캜. A method for producing a polyester-based elastomeric polymer, characterized in that the viscosity is increased by the condensation polymerization method.