KR100320768B1 - Process for preparing a polyester containing additives - Google Patents

Abstract

The present invention is to disperse the additives in high concentration in one step in the polyester melt in the spinning process without going through the process of preparing a separate master batch chip or the polymerization step as in the conventional manufacturing method additives desired on the final product The present invention relates to a manufacturing method of diluting and uniformly distributing in two stages by joining with a substrate polyester to a content, followed by stirring.

Polyester fibers produced by the production method of the present invention is excellent in the dispersibility and workability of the additives and has a uniform physical properties.

Description

Process for preparing a polyester containing additives

The present invention relates to a method for producing an additive-containing polyester, in which various additives such as titanium dioxide, carbon black, pigments, stabilizers, brighteners, antistatic agents, and flame retardants are dispersed in high concentration in one step on a polyester melt on a melt kneading extruder. After this, the present invention relates to a method of quantitatively feeding the substrate polyester melt provided from the final polymerization tube of the melt extruder or the polymerization reactor, and passing the two melted polyesters through a stationary stirrer so as to be diluted and uniformly distributed in two stages.

Conventional methods of incorporating additives into polyesters generally fall into two broad categories.

The first method is a method of dispersing a matting agent such as titanium dioxide in the form of slurry in a dispersion medium such as ethylene glycol and adding it during the polymerization process. The second method is to prepare a high concentration additive masterbatch chip and then separate it in a spinning process. It is a method of adding to the desired content using a metering input equipment.

However, the method of adding the additive to the polymerization process causes depolymerization of the ester bond by ethylene glycol or containing moisture used for slurry production, and contamination of the reactor by the additive cannot be avoided.

Therefore, the method of addition to the polymerization process is suitable for the mass production of a single variety that does not change the type and content of the additive.

On the other hand, the master batch chip input method in the spinning process, which is mainly used for small quantity batch production methods, involves drying prior to use of the master batch chip, decomposition of polymer melt during re-melting of the master batch chip, and external contamination during handling of the master batch chip. And a decrease in workability due to poor dispersibility of the additive.

In order to compensate for the disadvantages of the method of adding the additive during the polymerization process as described above, German Patent 1924691 adds an additive slurry to the polyester melt in which the polymerization is completed in a separate additive mixing reactor, and then depolymerizes it to about 1 to 20 degrees. Although the obtained material is introduced into the polymerization reactor again to complete the polymerization, this process also inevitably avoids partial contamination of the main portion of the polymerization reactor, and also generates a thermal history of the polyester melt through a separate additive mixing reactor. It is easy to cause quality deterioration.

In addition, in order to improve the dispersibility of the master batch chip introduced in the spinning process, US Pat. No. 5,308,892 adds 0.01 to 5.0 moles of diols before adding an additive in the process of manufacturing the master batch chip to limit the amount of feed polyester. After the viscosity is reduced by about 1 to 70, this is mixed with an additive on an extruder, and then polyester is added to prepare a master batch chip.

This method not only avoids the disadvantage of the addition of the manufacturing process as described above, which is called master batch chip injection during the spinning process, but also lowers the viscosity at the time of manufacturing the master batch chip, resulting in low-polymerization of polyester. There is a problem that causes degradation and quality deterioration.

An object of the present invention is to provide a method for producing a polyester in which the additive is well dispersed while minimizing the problems of contamination and workability and quality deterioration in the production process by adding the additive in the spinning process. .

1 and 2 are schematic views of the manufacturing process of the present invention.

The present invention provides high functional materials such as gloss reduction, coloration, color improvement, thermal stability improvement, flame retardant and antistatic performance in polymer materials produced in the form of fibers through a melt spinning process such as polyester, polyamide or polyolefin. Inorganic or organic additives such as titanium dioxide, carbon black, pigments, brighteners, stabilizers, flame retardants, antistatic agents, crosslinking agents and barium sulfate added for high specific gravity, etc. It relates to a method of adding so that the quality of the final product is uniform.

That is, the present invention is introduced into the melt kneading extruder so that the content of the additive contained in the final fiber product is 0.02 to 5.0 weight, and then dispersing and distributing the additive step by step through one step high concentration dispersion and two step dilution uniform distribution process It relates to a method for producing a polyester in which the additive is well dispersed.

In the present invention, the polyester is a polymer of a condensate of an aromatic dicarboxylic acid such as terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, and glycols such as ethylene glycol, 1,3-propanediol, and 1,4-butanediol For example, polyethylene terephthalate, polyethylene 2,6-dinaphthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene isophthalate and the like and copolymers thereof may be used.

When described in detail by the accompanying drawings of the present invention.

In the present invention, conventional polyethylene terephthalate was used as the substrate polymer.

The polyethylene terephthalate is supplied to the melt extruder 3 through the feed hopper 1 of the substrate polyester chip and then melted (FIG. 1) in the form of a melt in the final polymerization tube 13 of the polymerization reactor (FIG. 2). After being transferred to the substrate polyester feed pipe (6- (1)), the melt kneading extruder (4) is joined at the joining point (9) with the modified polyester in which the additive is dispersed in high concentration in one step.

In Fig. 1, 7- (2) is the discharge tube of the extra modified polyester, and 6- (2) in Fig. 2 is the discharge tube of the extra substrate polyester.

The melt kneading extruder 4 may be a coaxial or bidirectional rotary twin screw melt extruder, an extruder having a kneading rotor and blades, a uniaxial continuous kneader and a melt extruder, and the like, in the present invention. A twin screw melt extruder was used.

The melt kneading extruder 4 is provided with a separate reforming polyester chip feed hopper 2 and an additive supply device 5 for supplying additives to the molten reforming polyester.

In the present invention, a general polyethylene terephthalate was used as the polymer to be supplied to the modified polyester chip feed hopper (2).

In the present invention, the amount of the additive contained in the modified polyester to be joined at the joining point 9 with the substrate polyester is 3 to 30 times the amount of the additive contained in the final fiber product. It is preferable to make ratio (A: B) of A) and modified polyester feed amount (B) into 2: 1-29: 1 by weight ratio.

In the present invention, if the additive content contained in the modified polyester is less than three times the additive content contained in the final fiber product, the capacity of the melt kneading extruder 4 for producing and supplying the modified polyester becomes larger than necessary to produce the product. Unfavorable in terms of cost, and exceeding 30 times, the additive content contained on the final fiber product becomes non-uniform, leading to deterioration in quality.

At the confluence point 9, the substrate polyester and the modified polyester are combined so that the content of the additive contained in the final fiber product is 0.02 to 5.0 weight, and is uniformly distributed in two stages while passing through the static stirrer 10.

If the amount of the additive to be added is less than 0.02 weight, the performance of the additive cannot be expressed, and if it exceeds 5.0 weight, it becomes difficult to uniformly disperse the additive and cause problems of trimming and excessive pack pressure increase during spinning.

As the stationary stirrer 10 used in the present invention, various types of products may be used, and the pressure loss generated while the polyester melt passes through the stationary stirrer 10 is 5.0Kg / cm 2 to 50.0Kg / cm 2. It is preferable to install so that.

If the pressure loss by the stationary stirrer 10 is less than 5.0 Kg / ㎠ it is difficult to obtain a sufficient uniform distribution effect of the additive, if it exceeds 50.0 Kg / ㎠ the viscosity decrease phenomenon due to excessive pressure loss and the temperature rise of the polymer melt It causes the problem of workability deterioration.

The polyester melt containing the additive uniformly dispersed by the manufacturing process of the present invention is spun and stretched through the metering pump 11 and the spinneret 12 as in the conventional polyester manufacturing process.

The measurement of the evaluation item shown in the Example and the comparative example was as follows.

Ultimate viscosity (IV)

The copolyester was dissolved in phenol / tetrachloroethane (weight ratio 50/50) to make 0.5 weight solution, and then measured at 35 ° C. with a Uberod viscometer.

Additive content

① titanium dioxide

After the polyester was sintered, sulfuric acid and ammonium sulfate were added to dissolve the remaining titanium dioxide, and then, hydrogen peroxide solution was added to give a yellowish orange color. The absorbance was measured on a spectrophotometer, and the content was measured from a calibration curve prepared in advance.

② carbon black

Carbon black-added polyester was dissolved in phenol / tetrachloroethane (weight ratio 50/50), and then absorbance was measured on a spectrophotometer to determine the content in terms of a calibration curve prepared in advance.

Additive dispersibility

The polyester was melted at 295 ° C. using a single screw extruder with a D = 19 mm, L = 475 mm and a compression ratio of 1: 4, and then raised for 1 hour while passing through a 10 μm (area 2.83 cm 2) filter at a discharge rate of 18 cc / min. The pressure to measure was measured.

Workability

The spinning workability of the polyester fiber containing the additive was evaluated by the trimming and cutting of the yarn when spinning 100 kg of the product with 250 denier yarns at a winding speed of 3,100 m / min according to a conventional method.

◎ (excellent): no trimming, single trimming

○ (Good): One time of four times

△ (normal): 4 to 4 times

불 (poor): not more than 5 times

Hereinafter, the present invention will be specifically described based on Examples and Comparative Examples.

Example 1

As shown in Table 1, a conventional polyethylene terephthalate chip having an intrinsic viscosity of 0.64 and no additives was supplied through a chip feed hopper 1 for substrate polyester as shown in FIG. 1 at a feed rate of 9.31 Kg / hr. It was then melted and transferred to the substrate polyester supply pipe (6- (1)).

Meanwhile, a conventional polyethylene terephthalate chip having an intrinsic viscosity of 0.64 was supplied at a feed rate of 5.79 Kg / hr through a modified polyester chip feed hopper (2) to a co-rotating twin screw melt extruder, and then added to the melt. Titanium dioxide was introduced at a feed rate of 0.21 Kg / hr through the feeder 5 to be dispersed in one step.

A portion of the modified polyester melt dispersed in one step at a temperature of 220 ° C. to 270 ° C. on a twin screw melt extruder so that the content of titanium dioxide is 3.5 weight is modified polyester feed pipe at a feed rate of 1.034 Kg / hr (7- (1)). ) And a modified polyester metering pump (8) at the point of incorporation (9) with the substrate polyester so that the content of the additive on the final yarn is 0.35 weight.

Modified polydispersed in one step so that the ratio (A: B) of the substrate polyester feed amount (A) and the modified polyester feed amount (B) was 9: 1 by weight to be 10 times the titanium dioxide content contained in the final product. After the ester and the substrate polyester melt are combined, two stages of dilution and uniform distribution are carried out while passing through the stationary stirrer 10 arranged to have a pressure loss of 20.0 Kg / cm 2, and the metering pump 11 and the spinneret as usual. Through (12) was spun into 250 denier yarn at a winding speed of 3,100m / min and the results are shown in Table 2.

Examples 2, 3, 4, 5 and Comparative Examples 1, 2, 3

As shown in Table 1, the substrate polyester feed amount, the modified polyester feed amount, the additive type, the additive content in the first stage dispersion, the second stage dilution ratio, the pressure loss in the stationary stirrer 10, the final additive target content Except for the above, the same procedure as in Example 1 was carried out.

The results obtained at this time are shown in Table 2.

<Table 1>

division Substrate Polyester Supply (A: Kg / hr) 1st stage dispersion 2-step dilution distribution Yarn additive additive target content (weight) Modified Polyester Supply (B: Kg / hr) Type of additive Additive content (weight) Dilution ratio (A: B) Stationary Stirrer Pressure Loss (Kg / ㎠) Example 1 9.306 1.034 Titanium dioxide 3.5 9: 1 20.0 0.35 Example 2 9.995 0.345 Titanium dioxide 15.0 29: 1 20.0 0.5 Example 3 9.306 1.034 Titanium dioxide 50.0 9: 1 20.0 5.0 Example 4 9.995 0.345 Titanium dioxide 0.6 29: 1 20.0 0.02 Example 5 6.893 3.447 Carbon black 9.0 2: 1 20.0 3.0 Comparative Example 1 8.272 2.068 Titanium dioxide 40.0 4: 1 3.0 8.0 Comparative Example 2 10.082 0.259 Titanium dioxide 20.0 39: 1 20.0 0.5 Comparative Example 3 6.893 3.447 Carbon black 9.0 2: 1 55.0 3.0

* Polyester used: Polyethylene terephthalate with an ultimate viscosity of 0.64

<Table 2>

Yarn additive content Sprayability (Kg / ㎠) Workability 5 measurements average (weight) % Change Example 1 0.35 1.2 11 ◎ Example 2 0.51 2.1 13 ◎ Example 3 5.0 1.5 25 ○ Example 4 0.02 2.0 9 ◎ Example 5 3.0 1.5 28 ○ Comparative Example 1 8.1 6.3 More than 100 × Comparative Example 2 0.52 7.4 15 △ Comparative Example 3 3.0 1.3 23 ×

* Change rate of additive content of yarn () = (standard deviation / average) × 100

* Workability: ◎ (Excellent), ○ (Good), △ (Normal), Ⅹ (Poor)

In the present invention, in the method of adding an additive in the polyester manufacturing process, as in the conventional manufacturing method, the additive is directly added to the polyester melt in the spinning process without a separate master batch chip manufacturing or polymerization step addition process in the second step. By dispersing uniformly throughout, it is possible not only to produce various kinds of polyester fibers, but also to minimize the problems of production process contamination, workability and final product quality due to the addition of additives. It can manufacture.

Claims (4)

At the confluence point 9, the substrate polyester supplied from the melt extruder 3 or the polymerization reactor final polymerization tube 13 and the modified polyester containing the additive dispersed in one step in the melt kneading extruder 4 are combined. In the process of spinning polyester fibers by two-step dilution and uniform distribution while passing through the static stirrer 10, the melt kneading extruder 4 is supplied with a chip feed hopper 2 for a modified polyester. After the melt is attached, an additive supply device 5 for supplying an additive on the molten polymer is attached, and the modified polyester melt containing the additive dispersed in one step is passed through the modified polyester metering pump 8 to the final fiber. A method for producing an additive-containing polyester, characterized in that it is fed to the confluence point (9) so as to have a desired additive content on the product. The substrate polyester supply amount (A) and the modified polyester supply amount so that the content of the additive contained in the substrate polyester and the modified polyester to be joined is 3 to 30 times the content of the additive contained on the final fiber product. Method for producing a polyester containing an additive, characterized in that the ratio (A: B) of (B) is 2: 1 to 29: 1. The method of claim 1, wherein the matrix polyester and the modified polyester are joined to each other so that the content of the additive contained in the final fiber product is 0.02 to 5.0 weight. The method of producing a polyester fiber containing an additive according to claim 1, wherein a static stirrer is installed so that the pressure loss generated while the polyester melt passes is 5.0 Kg / cm 2 to 50.0 Kg / cm 2.