KR100525064B1 - Alkaline easily soluble copolyester polymer for polyester composite fiber and its manufacturing method using terephthalic acid process, and polyester composite fiber therefrom. - Google Patents

Abstract

The present invention relates to an alkali-soluble copolyester polymer having a general polyester alkali reduction rate of 50 times or more, a preparation method thereof, and a polyester composite fiber using the same. Specifically, a bishydroxy ethyl isophthalate containing a metal sulfonate salt prepared by reacting a dimethyl isophthalate component containing a metal sulfonate salt with ethylene glycol using a batch polymerization method using terephthalic acid as a raw material in the polymer. 1 to 6 mol% of the dieside component is added, and isophthalic acid component is added to 0.01 to 5% by weight of the dieside component in the polymerized product, subjected to esterification at an esterification rate of 96% or more, and then transferred to the polycondensation reaction tank. 100 to 500 ppm of antimony trioxide as a polycondensation catalyst and 3 to 15% by weight of polyalkylene ether glycol having a molecular weight of 1,000 to 20,000 were added to the polymer to polymerize the oligomer filter and the pack exchange cycle during spinning. Alkali-soluble copolyesters having a good melting temperature of 205-240 ° C. and methods for their preparation, And it relates to a copolyether polyester composite fibers with ester polymers.

Alkali-soluble copolyester polymer produced by the present invention is excellent in the cycle of replacement of the oligomer filter by the unreacted material at the time of polymerization, the polymerization processability is good, and the composite fiber produced by complex spinning from the conventional polyester fiber It has a strength similar to that of the excellent alkali dissolving property, thus facilitating the preparation of microfiber.

Description

Alkaline easily soluble copolyester polymer for polyester composite fiber and its manufacturing method using terephthalic acid process, and polyester composite fiber therefrom.

The present invention relates to alkali-soluble copolyester polymers for composite fibers. More specifically, it has excellent alkali-elasticity, and pack pressure increase during spinning is similar to that of ordinary polyester, and thus workability is excellent. The present invention relates to a composite-use alkali-soluble copolyester polymer using a terephthalic acid polymerization method that enables the mechanical properties of yarns to be similar to a general polyester, a method for preparing the same, and a polyester composite fiber using the same.

In addition, the present invention is a composite in which a bishydroxy ethyl isophthalate component containing a metal sulfonate salt and a poly alkylene ether glycol are copolymerized in order to increase alkali availability, and the isophthalic acid component is copolymerized in order to increase the ester reaction rate of terephthalic acid. The present invention relates to an alkali-soluble copolyester polymer, a preparation method thereof, and a polyester composite fiber using the same.

In addition, the present invention is not only similar to the general polyester in the melt viscosity in the molten state at the time of the composite spinning for the production of microfiber, not only similar to the general polyester yarn, but also has a high melting temperature workability of flammable, knit knitting, etc. The present invention relates to an excellent composite use alkali-soluble copolyester polymer, a preparation method thereof, and a polyester composite fiber using the same.

In general, polymers having a high alkali elution rate are widely used for producing ultrafine yarns, and Japanese Patent Application Laid-open No. Hei 9-291418, Japanese Patent Application Laid-open No. Hei 8-92819, and Patent No. Publication 12-95850 and much more.

However, Japanese Patent Laid-Open No. 9-291418 discloses that the metal sulfonate-containing dimethyl isophthalate (hereinafter DMS) component is 1 to 5 mol% based on the total acid component, and the polyalkylene ether glycol is 5 to 25 weight percent based on the copolyester. % Copolymerized, but the detailed manufacturing method is not shown. The production is different from the configuration of the present invention because it adopts the DMT method and uses a metal sulfonate-containing dimethyl isophthalate. In addition, its use is not a composite yarn, but a single fiber, which is different from the ultrafine composite spinning yarn for the purpose of the present invention.

In addition, Japanese Unexamined Patent Application Publication No. Hei 8-92819 et al., Although the use of the polymer is different from the present invention, in order to suppress the increase in the melt viscosity of the polymer when the metal sulfonate-containing dimethyl isophthalate is added, the anionic and cationic non-reactive compound of the phosphorus system. A method of lowering the melt viscosity by adding is proposed.

In JP-A-12-95850, there is proposed a polymer having a content of 25 equivalents / ton or less of a terminal carboxylic acid group copolymerized with a metal sulfonate group-containing dimethyl isophthalate and a polyalkylene glycol having an average molecular weight of 1000 to 10000. The polymerization method proposes to add a metal sulfonate-containing dimethyl isophthalate to the reactor at the time when the esterification reaction rate becomes an oligomer having 80 to 96%, and then add polyalkylene glycol.

However, since the present invention is based on the annual hollow process, the metal sulfonate compound does not exist in the ether reactor, but in the batch method, the metal sulfonate compound is always present in the ester reaction tank, which makes it difficult to increase the ester reaction rate.

In addition, the alkali-elutable polymer produced by the above-mentioned method has a sharp increase in melt viscosity due to the addition of DMS, making it difficult to produce a high molecular weight polymer. Thus, in Japanese Unexamined Patent Publication No. 59-93722, the low viscosity of 0.2-0.4 A method for producing a polymer having a desired molecular weight by solid-phase polymerizing a polymer is also proposed.

However, these polymers are commonly copolymerized with DMS, and the reaction proceeds by the transesterification reaction, which is the same method in the DMT polymerization method in which a polyester is polymerized using dimethyl terephthalate (abbreviated to DMT) as a raw material. As a result, almost no unreacted DMS component remains, but the DMT polymerization method has a disadvantage in that the manufacturing cost is higher than that of the TPA polymerization method using terephthalic acid as a raw material.

As described above, in the TPA polymerization method using terephthalic acid (hereinafter abbreviated as TPA) as a raw material, the reaction of DMS does not proceed, which causes problems such as an increase in pack pressure when spinning as unreacted material, and also DMT. Unlike the polymerization method, in the TPA polymerization method, the unreacted TPA remains, and unlike the unreacted DMT, the unreacted TPA is not melted and dissolved in the oligomer or polymer, so it is caught in the oligomer filter or the polymer filter, and these are aggregated with the unreacted DMS. This causes problems such as shortening of the filter replacement cycle of the oligomer.

Accordingly, the present invention is to solve the problems as described above, by using the TPA polymerization method to prepare a low-cost alkali-soluble copolyester polymer, to increase the replacement cycle of the oligomer filter to improve the polymerization processability, general The purpose of the present invention is to provide an alkali dissolving rate of 50 times faster than a polyester polymer, and a melt-visible alkali-soluble copolyester polymer having a general polyester level, a method for preparing the same, and a polyester composite fiber using the same.

Hereinafter, the present invention for solving the above object will be described in detail. The present invention uses a metal sulfonate group-containing bishydroxy ethyl isophthalate (formula (1), hereinafter abbreviated as DES) instead of DMS.

This is because the DMS has a low reactivity with ethylene glycol (hereinafter EG) in the TPA polymerization method and thus remains in the DMS state, causing a pack pressure increase. Therefore, DMS was reacted separately with EG, and a metal sulfonate group-containing bis hydroxy ethyl isophthalate (hereinafter abbreviated as DES) having a structure of Formula (1) was used as a raw material.

--------------- Equation (1)

However, M represents Na, Li, K and Na and Li were used in Examples of the present invention.

A method for manufacturing DES industrially is disclosed in Korean Patent Laid-Open Publication No. 2003-0024191.

The content in the polymer of DES represented by the formula (1) is preferably in the range of 1.5 to 6.0 mol% based on the total dieside. If the content of DES is less than 1.5 mol%, the elution to the alkali solution of the polymer is low, and thus it is not valuable as an ultra-fine alkali-soluble polyester polymer. If the content of the DES exceeds 6.0 mol%, the melt viscosity is high and radioactivity is not good. It is difficult to obtain a polymer having a degree of polymerization, and the melting temperature (Melting Temperature) of the polymer is too low, resulting in process difficulties such as flammability.

In addition, polyalkylene ether glycol (hereinafter, abbreviated as PAG) used in the present invention used a raw material represented by the following formula (2).

H {-O (CH ₂ ) _m } _n -OH ----------------- Formula (2)

However, m is an integer of 1-4, n is an integer of 2 or more, and the degree of polymerization differs according to the molecular weight of polyalkylene ether glycol. In the exemplary embodiment of the present invention, polyethylene ether glycol (hereinafter abbreviated as PEG) and poly tetramethylene ether glycol (hereinafter abbreviated as PTMG) having m of 2 were used.

The content of the PAG in the polymer is in the range of 3 to 15% by weight relative to the weight of the polymer. If the content of PAG is less than 3% by weight, the elution of the alkaline aqueous solution is low, making it difficult to manufacture microfiber, and the DES content must be increased to increase the elution. In this case, it is difficult to obtain a polymer having high polymerization degree again. do. In addition, when the content exceeds 15% by weight, the melting temperature of the polymer is too low and the heat resistance of the PAG is lowered, which causes difficulty in quality control, and also creates a large amount of foam (foam), which makes it difficult to manage the polymerization process.

And in order to raise the ester reaction rate of terephthalic acid, the isophthalate component represented by Formula (3) was used.

---- Formula (3)

Provided that R is H in this case isophthalic acid or CH ₃ in this case dimethyl isophthalate.

The isophthalic acid component represented by formula (3) has the same molecular weight and properties but very high reactivity compared to terephthalic acid. By the Hammet Rule, the meta position isophthalic acid is more reactive than the para position terephthalic acid. In the present invention, since the TPA method containing terephthalic acid as a main raw material is used, isophthalic acid having R is H is used.

The content of isophthalic acid is preferably from 0.01 to 5% by weight, which is a content showing an ester reaction rate of 97% or more according to the polymerization prescription, and the replacement cycle of the oligomer filter is good. The role of isophthalic acid in the present invention is to increase the reaction rate of terephthalic acid, so the lower the content is better. If the content of isophthalic acid is more than 5% by weight, the melting point of the copolyester produced is too low, causing problems such as fusion in the combustible when forming the composite fiber. When the isophthalic acid content is less than 0.01% by weight, the ester reaction rate is too low to increase the content of unreacted TPA so that they form agglomerates with the metal sulfonate-containing dimethyl isophthalate which is not completely reacted during the preparation of Formula (1) to polymerize. Fairness will be lowered.

For the contents of DES and PAG, which directly affect the elution of alkali-soluble copolyester polymers, the mole percentage of the total dieside of DES is M (D), and the weight percentage of the polymer of PAG is W (P). It is appropriate that the sum of (D) and W (P) is between 4 and 21.

 That is, a range of 4 ≦ M (D) + W (P) ≦ 21 is appropriate.

If it is less than 4, elution in alkaline aqueous solution may not be enough and it may not divide.

And, if it exceeds 21, the melting point of the polymer is too low, the sacrificial property is lowered, and the increase in manufacturing cost is too high.

The melting temperature of the polymer (Melting Point, hereinafter abbreviated as T _m ) is preferably in the range of 205 to 240 ° C. If it is lower than 205 ℃, there is a problem that the spinning temperature is too low, there is a problem that the post-processability is bad, and if the spinning at a normal spinning temperature, the problem that the pyrolysis is too large. And the polymer composition higher than 240 ℃ by the composition of the present invention is not only impossible to manufacture, but also possible to increase the radiation temperature even if possible, so that the problem of pyrolysis occurs, which is not suitable for the purpose of the present invention.

The intrinsic viscosity of the polymer is preferably 0.50 to 0.75 dl / g. The lower the intrinsic viscosity, the more advantageous for the elution of the polymer, but too low the melt viscosity tends to be too low. If the intrinsic viscosity is less than 0.50dl / g, the viscosity of the polymer is too low to pelletize during discharge after polymerization or the melt viscosity is too low during spinning is easy to occur. If the intrinsic viscosity exceeds 0.75dl / g, the melt viscosity is too high to increase the spinning temperature, and if the spinning temperature is increased, problems such as pyrolysis are likely to occur.

Other raw materials used in the present invention will be described.

DES may be added at any stage of the Direct Esterification Reaction (DE reaction) in which TPA and EG react, but for ease of reaction and uniformity, the present inventors are in a process of preparing a slurry from TPA and EG. Input.

Polyalkylene ether glycol may be added at any point in the reaction if there is no problem in the polymerization operation. However, according to the TPA polymerization method according to the present invention, the liquid level of the esterification reaction tank is increased as the slurry is introduced, so that when the PAG is added to the esterification reaction vessel, the liquid level is increased in the same reactor by the generation of PAG foam. Productivity may be lowered, and when put into a polycondensation reaction tank, PAG, which is not compatible with polyester oligomer, is sucked into the vacuum system in the process of applying a vacuum, and the vacuum system is clogged. Therefore, the present inventors conducted various experiments, and after completing the esterification reaction, transferred the polyester oligomer to a polycondensation reactor (hereinafter, referred to as a PC reactor), and then slowly added a vacuum to control the vacuum system by adding a PAG. To minimize scattering.

In addition, isophthalic acid to be added to increase the esterification rate is naturally required to be added to the esterification reactor, the method is a method of adding in advance before the slurry is introduced, or a method such as TPA at the time of slurry production. The present inventors have selected a method of introducing into the slurry, such as TPA for ease of operation.

Since the alkali-soluble copolyester polymer according to the present invention includes PAG having low heat resistance, thermal stability at high temperature is weakened, so a stabilizer may be used to prevent this. As a stabilizer, a phosphorus stabilizer, a phenolic, and an amine stabilizer can be used effectively. Phosphate compounds such as trimethyl phosphate and triphenyl phosphate, phosphites such as triphenyl phosphite and phosphine compounds such as triphenyl phosphine can be used as phosphorus stabilizers. Examples of the Knox (Irganox) series and the amine-based, such as HLS (Hindered Amine Light Stabilizer) such as Tinuvin series of Shivagaigi can be used.

In addition, the physical properties of the polymer produced by the reaction was analyzed by the following method.

1. Ester reaction rate of terephthalic acid: The concentration of carboxylic acid was titrated using ester-reacted oligomer.

2. Polymer weight loss rate: Pellet polymer was crushed with liquid nitrogen and treated for 10 minutes using a 1.2 wt% NaOH aqueous solution at 95 ° C. to calculate the weight of the polymer before and after treatment.

3. Intrinsic Viscosity: The polymer was dissolved in a solution containing phenol and 1,1,2,2-tetrachloroethane in a 6: 4 weight ratio, and was measured using a Ubbelode tube in a 30 ° C thermostat.

4 Melting temperature: Perkin Elmer's DSC 7 (Differential Scanning Calorimetry) was used to increase the temperature to 10 ℃ / min was analyzed as a peak within the melting range.

5 Melt Viscosity: The prepared polymers were rolled in a vacuum dryer at 120 ° C. for 12 hours, and the viscosity at Shear Rate 608 at 285 ° C. was measured using poise of 1B of TOYOSEI.

6. Combustible work: Combing work using Murata Combustor using radiated partial orientation yarn to make X or 160m yarn with 3 or more wool and pin yarn. The case where two are seen is represented by (o) and the case where there is no.

7. Reduction rate of yarn: Knitting the prepared yarn, eluting with 1.2% NaOH solution, and analyzing the cross section of the yarn by Scanning Differential Microscopy (SEM) to see if there were any remaining parts other than the normal PET part. .

Hereinafter, the present invention will be described in detail with reference to Examples. However, the scope of the present invention is not limited by this embodiment.

<Example 1>

In the DES represented by the formula (1), a substance having M of Na was used (molecular weight 356.28 and dissolved in ethylene glycol (EG) at a concentration of 35% by weight).

The molar ratio of EG / (TPA + IPA + DES) is 1.12, the molar ratio of DES / (TPA + IPA + DES) is 4.0% using TPA, isophthalic acid (IPA) and DES and M of Na. In consideration of adding 5% by weight of PEG to 1% by weight of the IPA relative to the polymer to prepare a slurry.

In the DE reactor, the DES content of M is Na is 2.2 mol% and the oligomer containing 1% by weight of IPA compared to the polymer is maintained at 255 ° C.

Slurry was added at the time when the reactor internal temperature rose to 255 degreeC, and stirring was continued after completion | finish of slurry addition. At this time, the esterification reaction rate in the ester reactor was 97.2%.

The prepared oligomer was passed through a filter having a pore of 38 micrometers and transferred to a polycondensation reactor, and as a catalyst, 300 ppm of antimony trioxide as a catalyst, 300 ppm of phosphoric acid (Phosphoric Acid) as a stabilizer, and polyethylene glycol having a molecular weight of 4,000. 5 wt% of the polymer was added, and the reaction was started at 500 torr for 30 minutes, and then a high vacuum was started, and after 200 minutes in vacuum, the polymer was discharged. The intrinsic viscosity of the discharged polymer was 0.55 dl / g and the melting temperature was 220 ° C.

Using the prepared polymer and the general polyester polymer, the compound ratio between the alkali-soluble polymer having 37 island components and the general polyester polymer having an intrinsic viscosity of 0.63 dl / g containing 0.3 wt% of TiO ₂ as a quencher 30 The results of the analysis of the 75 denir / 36fila twisted yarns were prepared by fabricating partial alignment yarns of 120denir / 36fila seaweed island (Sea and Island Conjugate Fiber) 120denir / 36fila. Indicated.

Comparative Example 1

Except that 7 mol% of DES M is Na was added in the same manner as in Example 1 and the physical properties are shown in Table 1.

<Example 2>

Except that 3% by weight of IPA compared to the polymer was carried out in the same manner as in Example 1 and the physical properties are shown in Table 1.

Comparative Example 2

Except that 7% by weight of IPA compared to the polymer was carried out in the same manner as in Example 1 and the physical properties are shown in Table 1.

Comparative Example 3

Except that the polyethylene glycol having a molecular weight of 4000 was added 17% by weight relative to the polymer, it was carried out in the same manner as in Example 1 and the physical properties are shown in Table 1.

<Comparative Example 4>

The polymer of Example 1 was subjected to solid phase polymerization using a vacuum at 200 ° C. to prepare a polymer having an intrinsic viscosity of 0.83 dl / g, to prepare fibers, and the physical properties thereof are shown in Table 1 below.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 DES input (mol%) 4.0 4.0 7.0 4.0 4.0 4.0 PEG injection amount (% by weight) 5.0 5.0 5.0 5.0 17.0 5.0 IPA input amount (% by weight) 1.0 3.0 1.0 7.0 1.0 1.0 Intrinsic viscosity (dl / g) 0.55 0.57 0.49 0.60 0.76 0.83 Polymer weight loss rate (% by weight) 23 30 37 21 33 21 Melting temperature (℃) 220 218 203 198 214 220 Melt viscosity 218 197 243 216 183 249 Oligomer Filter Exchange (Batch) 9 9 6 11 10 9 Polymerization processability ◎ ◎ ｏ ◎ Scattering ◎ Yarn Species (den / fila) 74/36 75/36 75/36 75/36 75/36 75/36 Strength (g / d) 4.2 4.1 3.8 3.7 3.9 2.8 Elongation (%) 29 31 31 28 28 31 Combustible Workability ◎ ◎ × × ｏ ｏ

 -The evaluation of polymerization processability is evaluated by × when there is no problem such as fu or scattering when there is no problem such as scattering.

 * Evaluation of dissolution property is evaluated as ◎: very good, ｏ: good, △ poor

 The copolyester of the present invention has a low content of unreacted material and thus a low rate of pack pressure rise, an alkali dissolution rate is 50 times faster than that of a general polyester polymer, and a melt viscosity can provide a polymer having a general polyester level. .

In addition, the manufacturing method of the copolyester according to the present invention is easy to manufacture, it is possible to manufacture a polymer having a uniform physical properties and can produce a composite yarn having stable workability and physical properties and uniform alkali dissolution properties. .

Claims (4)

The bishydroxy ethyl isophthalate component containing the metal sulfonate salt represented by General formula (1) contains 1.5-6 mol% of the dieside component in a polymer, and the isophthalic acid component is 0.01- of the dieside component in the said polymer. 5 wt%, containing 3 to 15 wt% of polyalkylene ether glycol having an average molecular weight of 1,000 to 20,000 relative to the polymer, the resulting polymer has a melting temperature of 205 to 240 ° C and an intrinsic viscosity of 0.50 to 0.75 dl / g. The composite use alkali-soluble copolyester polymer characterized by the above-mentioned. ----- Equation (1) With the proviso that M represents Na, Li and K. ---- Formula (3) With the proviso that R is H or CH ₃ . The bishydroxy ethyl isophthalate component containing the metal sulfonate salt represented by General formula (1) contains 1.5-6 mol% of the dieside component in a polymer, and the isophthalic acid component is 0.01- of the dieside component in the said polymer. 5 wt%, containing 3 to 15 wt% of polyalkylene ether glycol having an average molecular weight of 1,000 to 20,000 relative to the polymer, the resulting polymer has a melting temperature of 205 to 240 ° C and an intrinsic viscosity of 0.50 to 0.75 dl / g. A polyester composite fiber characterized in that the composite is produced by complex spinning using an alkali-soluble copolyester polymer produced by the conventional polyester polymer. ----- Equation (1) With the proviso that M represents Na, Li and K. ---- Formula (3) With the proviso that R is H or CH ₃ .  In the method for producing a copolyester polymer containing terephthalic acid and ethylene glycol as a main raw material, In the polymerization of terephthalic acid and ethylene glycol, the bishydroxy ethyl isophthalate component containing the metal sulfonate salt represented by formula (1) is 1.5 to 6 mol% of the dieside component in the polymer and the isophthalic acid component of the dieside component in the polymer. Injecting 0.01 to 5% by weight to prepare a slurry; After the completion of the esterification of the slurry, a multi-use alkali-soluble copolyester polymer comprising the step of adding 3 to 15% by weight of polyalkylene ether glycol having an average molecular weight of 1,000 to 20,000 relative to the polymer. Manufacturing method. ----- Equation (1) With the proviso that M represents Na, Li and K. ---- Formula (3) With the proviso that R is H or CH ₃ . The method of claim 3, wherein A method for producing a mixed-use alkali-soluble copolyester polymer, which is produced by TPA polymerization method containing terephthalic acid as a main raw material.