KR100569678B1 - A extractable polyester and a process for preparing the same - Google Patents

Abstract

The present invention relates to a water-soluble polyester and a method for producing the same.

The water releasing polyester of the present invention is characterized in that the polyalkylene glycol (PAG) of the general formula (I) below having a molecular weight of 10,000 or more is copolymerized.

The eluted polyester of the present invention is prepared by dissolving a terephthaloyl chloride (TPC) and a polyalkylene glycol (PAG) of the general formula (I) having a molecular weight of 10,000 or more to prepare an elutable component of the general formula (II) Next, it is manufactured by the method of copolymerizing by adding the said elutable component in a polyester polymerization process.

In the formula (I) or (II), R1 and R2 are alkyl, n is an integer of 220 or more, and Y is a polyalkylene glycol having a molecular weight of 10,000 or more.

The water soluble polyester of the present invention is mainly used for the production of ultrafine fibers.

Description

Solvent-releasing polyester and its manufacturing method {A extractable polyester and a process for preparing the same}

The present invention relates to a fusible polyester used in the production of ultrafine fibers and a method for producing the same.

In general, microfibers are prepared by a composite spinning of a copolymer polymer or blend as a water soluble component and a homo polymer as a poorly soluble component, and then eluting the copolymer polymer as a water soluble component. As the copolymerized polymer which is a water-releasing component, a water-soluble copolymer is mainly used, and as a homopolymer which is a poorly water-soluble component, polyamide or polyethylene terephthalate is mainly used. The present invention relates to a copolyester (hereinafter referred to as a 'soluble polyester') and a method for producing the same, which are used as a soluble component in the production of ultrafine fibers as described above.

Conventional techniques for producing water-soluble polyesters used in the production of microfibers include, firstly, dimethylisophthalate sulfonate salt (hereinafter referred to as 'DMIS') or low molecular weight polyalkylene glycol (hereinafter referred to as 'PAG') during the polyester polymerization process. And a second blend of polyester and high molecular weight PAG. However, the method of copolymerizing DMIS during the polyester polymerization process has a problem in that the heat resistance of the polymer is lowered due to the ionicity of the DMIS and foreign substances such as carbides are generated. On the other hand, the method of copolymerizing low molecular weight PAG during the polyester polymerization process has a problem in that the processability such as spinning is poor when the PAG content is 10% or more, and the elution property is lowered when the PAG content is less than 10%. On the other hand, the method of blending the polyester polymer and the high molecular weight PAG is not uniformly dispersed due to the PAG not uniformly dispersed in the prepared soluble polymer, and the soluble polymer is not easily eluted in the elution process. There is a problem that occurs.

The present invention is to solve the problems of the prior art described above to provide a water-soluble polyester having a low foreign matter content such as gel or carbide in the polymer and excellent in uniformity and heat resistance.

The present invention is to provide a high-molecular-weight PAG is uniformly copolymerized in the polymer to facilitate the elution of the PAG and at the same time excellent in heat resistance, and a fusible polyester for the production of ultrafine fibers without foreign substances such as gel or carbide, and a method for producing the same.

The present invention relates to a water-soluble polyester used in the production of ultrafine fibers and a method for producing the same.

More specifically, the present invention relates to a water-releasing polyester characterized in that a polyalkylene glycol (PAG) having a molecular weight of 10,000 or more is copolymerized.

Hereinafter, the present invention will be described in detail.

First, a terephthaloyl chloride (hereinafter referred to as 'TPC') and a polyalkylene glycol (PAG) of the following general formula (I) having a molecular weight of 10,000 or more are reacted to prepare an elutable component of the following general formula (II).

In the formula (I) or (II), R ₁ and R ₂ are alkyl, n is an integer of 220 or more, and Y is a polyalkylene glycol having a molecular weight of 10,000 or more.

The molar ratio of TPC and PAG is preferably 1: 1 to 1: 3. The reaction conditions of TPC and PAG are preferably reacted with stirring at a temperature of 100 ° C. or more for 2 hours or more.

The eluted component of Formula (II) was washed with excess water to remove hydrochloric acid as a by-product and dried at about 100 ° C. Next, the elution component of the dried general formula (II) is added to the polyester polymerization step to copolymerize to prepare the water-releasing polyester of the present invention. At this time, the addition amount of the elutable component of the general formula (II) is adjusted so that the content of the copolymerized PAG in the water-soluble polyester is 5 to 50% by weight.

It is good. If the PAG content in the usable polyester is less than 5% by weight, the PAG elutability is poor and it is difficult to micronize the yarn. If the content is more than 50% by weight, the processability such as spinning is deteriorated.

The polyester polymerization step is carried out under the usual conditions of reacting dimethyl terephthalate and ethylene glycol.

In the present invention, 1% by weight or less of the alkane sulfonate salt of the general formula (III) may be optionally added simultaneously with the elutable component of the general formula (II) during the polyester polymerization process.

R ₃ ― So ₃ ^- M ⁺ (Ⅲ)

In formula (III), R ₃ is alkyl or aromatic dicarbonic acid and M is an alkali metal.

The water-soluble polyester of the present invention prepared in this way is uniformly copolymerized with polyalkylene glycol (PAG) having a molecular weight of 10,000 or more, so that it is easy to dissolve PAG in the elution process and spots due to undissolved residual PAG. This does not occur. In addition, since the water-soluble polyester of the present invention does not contain DMIS or contains only a very small amount, there is little degradation in polymer heat resistance due to the ionic component of DMIS, and foreign substances such as gels and carbides are not generated.

The water releasing polyester of the present invention is used in the production of ultrafine fibers as described above. Specifically, after the composite spinning of the water-soluble polyester of the present invention and poorly water-soluble polymers such as polyethylene terephthalate and polyamide together, eluting polyester is eluted in the elution process to produce ultrafine fibers.

The microfibers produced using the water-soluble polyester of the present invention have no spots due to unextracted PAG components and are excellent in heat resistance. In addition, the cutting rate is reduced in the production of ultrafine fibers.

In the present invention, the criteria for evaluating various physical properties or properties of the usable-release polyester and the microfiber are as follows.

Polyethylene glycol (hereinafter referred to as 'PEG') content (Wt%)

Using a nuclear magnetic resonance spectroscopy (NMR) 300MHZ to determine the weight of the PEG in the fusible polyester obtained by the following equation.

Intrinsic viscosity (IV)

After dissolving the soluble polyester in 2 g / 25 ml of solvent O-chlorophenol, the temperature of the solution was adjusted to 25 ° C. and measured with a capillary viscometer.

Radiation processability

Relative evaluation is performed by measuring the number of times of cutting for 10 hours in a small radiator.

◎: less than 5 times of cutting

(Circle): 5 times or more cuts and 20 times

△: more than 20 rounds of cuts

Foreign body content (Wt%)

A solution was prepared by dissolving 100 g of the eluted polymer in 1 L of O-chlorophenol for 1 hour at 100 ° C., filtering the solution with a 5 μm filter, and substituting the weight of the solution before and after Obtain

Foreign matter

After slicing the polymer, the polymer was observed 400 times with an optical microscope, and the number of carbides or gels was measured five times to obtain an average value.

◎: less than 5 foreign bodies

○: 5 to 20 foreign objects

△: more than 20 foreign materials

Heat resistance (Wt%)

Heat-treat the polymer 3g at 280 ℃ for 4 hours to measure the amount of pyrolysis loss three times to determine the average value and substitute the following equation to obtain the weight percent of the decomposition loss.

Polymer elution (min)

The average value is obtained by measuring three times the time when 1 g of the soluble polymer is completely dissolved in 100 ml of an aqueous 1% by weight aqueous sodium hydroxide solution having a temperature of 90 ° C.

Yarn elution (Wt%)

10 g of the composite spun yarn was added to 100 ml of a 1 wt% caustic soda solution and treated at 90 ° C. for 30 minutes to measure the weight of the remaining yarn.

The measured elution (eluted amount of yarn) is evaluated by substituting the measured weight into the following equation.

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

Elutable ingredient manufacturing

First, 50 g of TPC and polyethylene glycol having a molecular weight of 16,000 (hereinafter referred to as 'PEG') are reacted for 50 hours (molar ratio = 1: 1) at 230 ° C. for 5 hours to prepare a ready-release component, followed by washing with 1000 parts by weight of water. By-product hydrochloric acid is removed and dried at 100 ° C.

Produced polyester (copolymer)

Next, in a separate polymerization tube, dimethyl terephthalate and ethylene glycol are zinc acetate-catalyzed and reacted while raising the temperature to 240 ° C. for 3 hours to allow methanol to flow out. Subsequently, phosphoric acid and antimony oxide were added thereto, immediately before the high vacuum conversion, 20% by weight of the extracted component prepared above and 0.5% by weight of DMIS were added, followed by polymerization at 280 ° C for 3 hours under high vacuum to obtain the water-releasing polyester of the present invention. (Copolymer) is prepared.

Microfiber Manufacturing

The conjugated spun polyester (copolymer) is used as a sea component, and polyethylene terephthalate is conjugated to a island component to prepare a composite fiber, and then the eluted polyester is eluted with an aqueous solution of caustic soda to prepare a microfiber.

Example 2-Example 6

The solvent-elutable polyester and the microfiber are manufactured in the same process and conditions as in Example 1 except that the conditions for the elutable component and the conditions for the elutable polyester are changed as shown in Table 1. Table 3 shows the results of measuring the properties and spinning properties of the prepared fusible polyester and microfiber.

<Table 1>

Preparation Conditions of Example

division Elutable Ingredients Manufacturing Conditions Elution polyester manufacturing conditions TPC content (g) PEG content (g) Reaction temperature (℃) Response time (hours) TPC: PEG molar ratio Copolymer Content (Wt%) Copolymer Injection Time Elution Polyester DMIS Example 1 50 50 230 5 1: 1 20 0.5 Just before high vacuum transition Example 2 50 100 230 5 1: 2 20 0 Just before high vacuum transition Example 3 50 200 230 5 1: 4 20 0 Just before high vacuum transition Example 4 50 100 230 3 1: 2 30 0 Polymerization reaction Example 5 50 100 200 10 1: 2 40 0.7 Polymerization reaction Example 6 50 100 150 20 1: 2 20 0 Polymerization reaction

Comparative Example 1

Produced polyester (copolymer)

Dimethyl terephthalate and ethylene glycol were zinc acetate-catalyzed in a polymerization tube and reacted while raising the temperature to 240 ° C. for 3 hours to release methanol. Subsequently, phosphoric acid and antimony oxide were added thereto, 8 mol% of DMIS immediately before high vacuum conversion was added, and polymerization was carried out at 280 ° C. for 3 hours under high vacuum to prepare a water-soluble polyester (copolymer) of the present invention.

Microfiber Manufacturing

The conjugated spun polyester (copolymer) is used as a sea component, and polyethylene terephthalate is conjugated to a island component to prepare a composite fiber, and then the eluted polyester is eluted with an aqueous solution of caustic soda to prepare a microfiber. Table 3 shows the results of measuring the properties and spinning properties of the prepared fusible polyester and microfiber.

Comparative Example 2 to Comparative Example 4

The usable-extracted polyester and the microfiber were prepared in the same process and conditions as in Comparative Example 1 except that the copolymer or blend composition added during the polyester polymerization process was changed as shown in Table 2. Table 3 shows the results of measuring the properties and spinning properties of the prepared soluble polyesters and microfibers.

<Table 2> Copolymer / Blend Composition of Comparative Example 1-Comparative Example 4

division Copolymer composition Blend Water Composition Comparative Example 1 DMIS 8 mol% - Comparative Example 2 DMIS 2 mol% PEG (molecular weight 6,000) 10Wt% - Comparative Example 3 DMIS 3 mol% PEG (molecular weight 20,000) 10% by weight Comparative Example 4 15 mole% of isophthalic acid (IPA) -

<Table 3> Evaluation results of characteristics and radioprocessability

division Release property polyester properties / characteristics Raw release (Wt%) Radio Machinability PEG content (Wt%) IV Foreign body content (Wt%) Foreign matter Elution (min) Heat resistance (Wt%) Example 1 10 1.02 0 ◎ 48 3 29 ◎ Example 2 13 1.21 0 ◎ 43 3.5 30 ◎ Example 3 18 1.43 0 ◎ 40 3.9 31 ◎ Example 4 13 1.29 0.01 ○ 42 3.3 30 ◎ Example 5 19 1.62 0.02 ○ 30 3.8 30 ◎ Example 6 8 0.99 0 ◎ 32 2.8 30 ◎ Comparative Example 1 0 0.60 0.25 △ 48 10 35 ○ Comparative Example 2 10 0.97 0.15 △ 55 6.2 25 ○ Comparative Example 3 10 0.99 0.19 △ 52 8.0 29 ○ Comparative Example 4 0 0.57 0.07 ○ 70 3.8 24 △

The water-soluble polyester of the present invention is excellent in the elution property in the elution step because the high molecular weight PAG is uniformly copolymerized. In addition, since the high-molecular weight PAG is used as a copolymer, the water-releasing polyester of the present invention does not contain DMIS or contains only a very small amount. As a result, deterioration of polymer heat resistance and foreign substances such as gels and carbides are not generated by the ionic component of DMIS.

Therefore, when the ultrafine fiber is manufactured from the usable polyester of the present invention, the cutting ratio is reduced, and spots due to the remaining elution components do not occur after the elution process, thereby improving the quality of the ultrafine fiber.

Claims (4)

Terephthaloyl chloride (TPC) is reacted with polyalkylene glycol (PAG) of the general formula (I) having a molecular weight of 10,000 or more to prepare an elutable component of the general formula (II) below, and then A method for producing a water-soluble polyester, which comprises adding an elutable component and copolymerizing it. In the formula (I) or (II), R ₁ and R ₂ are alkyl, n is an integer of 220 or more, and Y is a polyalkylene glycol having a molecular weight of 10,000 or more. The method of claim 1, wherein the terephthaloyl chloride (TPC) and polyalkylene glycol (PAG) in a molar ratio of 1: 1 to 1: 3 at least 100 hours to prepare a water-soluble polyester characterized in that the reaction Way. The method for producing a water-soluble polyester according to claim 1, wherein the eluted component is washed with water and then dried. The method for producing a water-releasing polyester according to claim 1, wherein 1% by weight or less of alkane sulfonate salt of formula (III) is added during the polyester polymerization step. R ₃ ― So ₃ ^- M ⁺ (Ⅲ) In formula (III), R ₃ is alkyl or aromatic dicarbonic acid and M is an alkali metal.