KR20020008317A - Process for the preparation of additive-containing polyester with enhanced dispersibility - Google Patents

Abstract

In the present invention, in the method of adding an additive added during the polyester manufacturing process, a separate high-concentration masterbatch chip is prepared as in the conventional method and then added thereto, or dispersed in a slurry form in a dispersion medium and then added in a polymerization step. By adding an additive in the spinning process, the additive is dispersed in a high concentration in the polyester melt in one step, then diluted in two steps with the additive content required by the final product, and uniformly dispersed in various varieties of polyester fibers. Not only can it be manufactured, but it is also possible to manufacture polyester products with well-dispersed additives that improve the generation of contamination and workability and quality deterioration due to the addition of additives.

Therefore, the polyester fiber produced by the manufacturing method of the present invention is excellent in the dispersibility and workability of the additives and has uniform physical properties.

Description

Process for the preparation of additive-containing polyester with enhanced dispersibility

In producing the polyester fibers, the present invention provides a substrate poly that is provided from a melt extruder after high concentration dispersion of a polyester melt in one step by a melt kneading extruder in order to effectively disperse various additives such as titanium dioxide in the polyester. The present invention relates to a method for producing a polyester, characterized in that a fixed quantity is fed to an ester melt, and the two melted polyesters are passed through the front end of the melt extruder and a stationary stirrer in two steps, and uniformly distributed.

Conventional methods for mixing various additives in polyester can be generally classified into two methods.

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

However, the method of adding the additive in the polymerization process has been a problem due to the generation of depolymerization of the ester bond by the ethylene glycol or the moisture contained in the slurry production and contamination of the reactor by the additive.

Therefore, the method of addition in the polymerization process is suitable for the mass production method of a single product that does not change the type and content of the additive. In addition, depending on the additive, it is difficult to expect good dispersion by the method of addition in the polymerization step, so that coarse particles aggregated in the polymer are often formed. On the other hand, the master batch chip input method in the spinning process, which is mainly adopted in the multi-product small quantity production method, is likely to cause problems such as deterioration of workability due to external contamination and poor dispersibility of additives during handling of the master batch chip.

In addition, in order to improve the dispersibility of the masterbatch chip added in the spinning process, before adding the additive in the masterbatch chip manufacturing process in US Patent No. 5308892

A method for producing a masterbatch chip is disclosed by adding 0.01 to 5.0 mol% of diols to lower the intrinsic viscosity of the feed polyester by 1 to 70%, then mixing in an extruder and further adding polyester.

This method requires not only additional operations in the manufacturing process to inject the master batch chip during the spinning process, but also lowers the extreme viscosity during the manufacture of the master batch chip, resulting in low-polymerization polyester, which reduces workability and quality. It causes problems that cause degradation.

The present invention is to provide a method for producing a polyester characterized in that the mixing of the additives in the spinning process, minimizing the occurrence of pollution and workability in the production process according to the additives, and improves the dispersibility of the additives. There is a purpose.

1 is a schematic representation of a manufacturing process of the present invention.

<Explanation of symbols for main parts of drawing>

1: Polyester chip feed hopper for substrate

2: polyester chip feed hopper for reforming

3: melt extruder 4: melt kneading extruder

5: additive feeder 6: metering pump

7-1: confluence point 7-2: melt extruder tip

8: melt feed line 9: stationary stirrer

10: radiation metering pump 11: spinneret

In the present invention, in the polymer fiber material manufactured in the form of fiber through melt spinning process such as polyester, polyamide or polyolefin, the present invention imparts functionality such as gloss reduction, coloration, color improvement, thermal stability improvement, flame retardant and antistatic performance. To improve the dispersibility of inorganic or organic additives such as titanium dioxide, carbon black, pigment, varnish, stabilizer, flame retardant, antistatic agent, crosslinking agent, barium sulfate, etc. It relates to a method for producing a polyester to be.

That is, the present invention is stepwise through a one-step high concentration dispersion and two-step dilution uniform dispersion distribution process in the polyester melt by the melt kneading extruder during the spinning process so that the content of the additive contained in the final fiber product is 0.02 to 5.0% by weight It is related with the manufacturing method of polyester which makes it excellent in the dispersibility of an additive.

The polyester in the present invention is a condensed polymer 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.

Hereinafter, the present invention will be described in detail with reference to the manufacturing process of FIG.

In the present invention, a general polyethylene terephthalate as a substrate polyester chip

Chip was used.

The conventional polyethylene terephthalate is fed to the melt extruder 3 through the polyester chip feed hopper 1 for the substrate and then melted, and is separately added to the melt kneading extruder 4 for high concentration addition and dispersion of the additive. The hopper (2) for supplying the modified polyester chip and the additive supply device (5) for supplying the additive are provided.

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

In the present invention, the melt supplied from the melt kneading extruder 4 in which the additive is dispersed in a high concentration at the confluence point 7-1 immediately after the transfer step and the melting step of the melt extruder 3 to which the substrate polyester is supplied is metered. It is supplied by the pump 6 by a fixed amount, and it is diluted and disperse | distributed in the front-end | tip part 7-2 of the melt extruder 3, and the stationary stirrer 9. Substrate polyester feed amount (A) so that the content of the additive contained in the modified polyester to be joined at the joining point (7-1) in the present invention is 4 to 30 times the additive content contained in the final fiber product (A ) And the ratio (A: B) of the modified polyester feed amount (B) is preferably 3: 1 to 29: 1 by weight.

In the present invention, when the additive content contained in the modified polyester is less than four times the additive content contained in the final textile product, the capacity of the melt kneading extruder 4 for producing and supplying the modified polyester becomes larger than necessary. It is not preferable in terms of production cost, and it becomes difficult to control the tip pressure of the melt extruder 3, resulting in a large imbalance between the object and the additive content. In addition, when the additive content exceeds 30 times the additive content contained in the final fiber product, the content of the additive contained in the final fiber product is uneven due to an excessively large dilution ratio, resulting in deterioration of quality.

The polyester chip supplied from the substrate polyester chip supply hopper 1 is supplied by the metering pump 6 to the confluence point 7-1 located immediately after the melting step after the transfer step of the melt extruder 3. The modified polyester is fed so that the content of the additive contained in the final fiber product is 0.02 to 5.0% by weight, which is diluted and uniformly distributed in two stages by the front end portion 7-2 and the stationary stirrer 9 of the melt extruder.

In case of the position of the confluence point 7-1 where the modified polyester is joined to the substrate polyester, if it is installed before the melting step of the melt extruder 3, the transfer of the substrate polyester and the melt pressure of the melt extruder 3 The fluctuation becomes large, resulting in object nonuniformity such as poor workability and nonuniformity of additive content.

When the amount of the additive to be added is less than 0.02% by weight, the performance cannot be expressed, and when it exceeds 5.0% by weight, it is difficult to uniformly disperse the additive, such as trimming and excessive pack pressure increase during spinning.

Stationary stirrer (9) used in the present invention may be used in a variety of conventional forms, the pressure loss generated while the polyester melt passes through the stationary stirrer (9) is within the range of 5.0 ~ 50.0Kg / ㎠ It is preferable to use.

When the pressure loss by the stationary stirrer 9 is less than 5.0 Kg / cm 2, it is difficult to obtain a sufficient uniform distribution effect of the additive, and when the pressure loss exceeds 50.0 Kg / cm 2, the viscosity decrease due to excessive pressure loss and the temperature rise of the polymer melt are increased. There is a defect in workability. The polyester melt containing the additive uniformly dispersed by the manufacturing process of the present invention is spun through the radiation metering pump 10 and the spinneret 11 through the melt supply pipe 8 as in the conventional polyester manufacturing process. .

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

Ultimate viscosity (IV):

The polyester was dissolved in phenol / tetrachloroethane (50/50 by weight) to make a 0.5% by weight solution and measured at 35 ° C. with a Uberod viscometer.

2. Additive Content:

① Titanium Dioxide

After the polyester was sintered, sulfuric acid and ammonium sulfate were added to dissolve the remaining titanium dioxide, followed by the addition of hydrogen peroxide to color the yellow orange color. The absorbance was measured using a spectrophotometer, and the content was measured from the calibration curve prepared in advance.

② carbon black

Polyester with carbon black was added to phenol / tetrachloroethane (weight ratio 50/50).

After melting, the absorbance was measured on a spectrophotometer, and the content was measured from a calibration curve prepared in advance.

3. 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.

4. Workability

Spinning workability of the polyester fiber containing the additive according to a conventional method

Trimming when spinning 100 kg of product with 250 denier yarn at a winding speed of 3,100 m / min;

Evaluated by single trimming.

◎ (excellent): no trimming, no single trimming ○ (good): one trimming, single trimming

△ (normal): four to four times for trimming and single trimming × (bad): five or more trimming and trimming

Hereinafter, the present invention will be described in more detail with reference to 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 is supplied through a polyester chip feed hopper 1 for a substrate as shown in FIG. 1 at a feed rate of 9.31 Kg / hr. After melt transfer.

On the other hand, through the modified polyester chip supply hopper (2) to the co-rotating twin-screw melt extruder to supply the melt of the usual polyethylene terephthalate chip having an ultimate viscosity of 0.64 at a feed rate of 5.79 Kg / hr, and then the additive Titanium dioxide was introduced into the molten reforming polyester at a feed rate of 0.21 Kg / hr through the feeder 5 to be dispersed in one step, and then 220 to 270 on a twin screw extruder so that the titanium dioxide content was 3.5% by weight. A portion of the modified polyester melt dispersed in one step at a temperature of &lt; RTI ID = 0.0 &gt; C &lt; / RTI &gt; was subjected to a modified polyester feed tube and modified polyester metering pump 6 at a feed rate of 1.034 Kg / hr so that the additive content of the final fiber was 0.35% by weight. Join with substrate polyester at confluence point 7-1.

At this time, the dilution ratio (A: B) of the substrate polyester feed amount (A) and the modified polyester feed amount (B) is 9: 1 by weight, and melt kneading extruder (10) to be 10 times the titanium dioxide content contained in the final fiber product. The modified polyester dispersed in one step in 4) and the substrate polyester melt at the confluence point 7-1 installed after the melting step in the melt extruder 3 are combined with the front end portion 7-2 of the melt extruder and 20.0 Kg. Two-stage dilution, uniform dispersion distribution while passing through a static stirrer (9) arranged to have a pressure loss of / cm 2 level, and spun into 250 denier fibers at a winding speed of 3,100 m / min in a conventional manner, the result Table 2 shows.

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

In the following Table 1, the substrate polyester feed amount (A), the modified polyester feed amount (B), the additive type, the additive content in the first stage dispersion, the second stage dilution ratio (A: B), in the stationary stirrer (9) Was carried out in the same manner as in Example 1 except that the pressure loss, the final additive target content, and the injection position of the modified polyester. The results obtained at this time are shown in Table 2.

Table 1

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

TABLE 2

* Flux additive content variation (%) = (standard deviation / average) × 100

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

The present invention is a method of adding an additive to be added in the polyester manufacturing process, without the addition of a master batch chip of a high concentration additive as in the conventional method, or by dispersing in the form of slurry in the dispersion medium in the polymerization step, additives In order to effectively disperse the high-density dispersion in the polyester melt in one step on the melt kneading extruder, the two polyester melts are quantitatively supplied to the substrate polyester melt provided from the melt extruder and the melted extruder tip and the stationary stirrer By diluting and uniformly distributing in two stages, it is possible not only to manufacture various varieties of polyester fibers, but also to minimize the occurrence of contamination, deterioration of workability, and deterioration of quality due to the addition of additives. On this enhanced poly It was able to produce the Termini fibers.

Claims (5)

After joining the substrate polyester supplied from the melt extruder 3 and the modified polyester containing the additive supplied from the melt kneading extruder 4, the two joined polyester melts are diluted, uniformly distributed, and then the fibers are separated. In the spinning process, an additive supply device 5 for supplying an additive to the molten reforming polyester separately from the reforming polyester chip supply hopper 2 is installed in the melt kneading extruder 4, and in one step, The modified polyester melt dispersed in high concentration in the melt kneading extruder 4 is metered by the metering pump 6 to the confluence point 7-1 so that the final fiber product can have the desired additive content. Of the polyester fiber containing the additive, characterized in that the tip portion 7-2 and the stationary stirrer 9 are diluted in two stages and distributed uniformly. Manufacturing method. The substrate polyester feed amount according to claim 1, wherein the amount of the additive contained in the modified polyester joining at the joining point (7-1) is 4 to 30 times the amount of the additive contained in the final textile product (A And a ratio (A: B) of the modified polyester feed amount (B) to 3: 1 to 29: 1 by weight. The modified polyester which joins the substrate polyester at the confluence point 7-1 is conveyed and supplied using the metering pump 6 so that the additive content contained in the final fiber product is 0.02 to 5.0% by weight. Method for producing polyester fiber containing the additive The joining point 7-1 is characterized in that the polyester chip supplied through the polyester chip supply hopper 1 for the substrate is installed immediately after the transfer step and the melting step of the melt extruder 3. Manufacturing method of polyester fiber containing additive The method of producing a polyester fiber with an additive according to claim 1, wherein the pressure melt generated when the polyester melt passes through the stationary stirrer (9) is used within the range of 5.0 to 50.0 kg / cm 2.