TWI386430B - Which does not contain heavy metal antimony PET resin and the PET polyester fibers - Google Patents

Description

PET resin without helium heavy metal and PET polyester fiber made thereof

The present invention relates to a PET resin, and more particularly to a PET polyester fiber which is excellent in hue and contains no barium heavy metal, which is obtained by using such a PET resin.

A conventional method for preparing polyethylene terephthalate (PET) resin is to use pure terephthalic acid (PTA) and ethylene glycol (EG) as raw materials, and the first direct esterification reaction is carried out. Esterification) and a second stage of polycondensation, further adding a bismuth (Sb) catalyst to the second stage polycondensation reaction, or adding a solid state polymerization reaction after completion of the second stage polycondensation reaction, as needed It is obtained by increasing the molecular weight.

The obtained PET resin is often used in the manufacture of PET polyester fibers because of its excellent mechanical strength and chemical resistance. However, in the production process of PET polyester fiber, because PET resin uses bismuth (Sb) as a polycondensation catalyst, in the process of melt spinning, a large amount of ethylene glycol oxime is often volatilized and accumulated in the spray. On the surface of the silk plate, in addition to the foreign matter that needs to be cleaned frequently on the surface of the spinneret, the molten PET polymer cannot flow normally from the spinning orifice of the spinneret, and the melt spinning often occurs. Broken wire phenomenon.

In order to solve the above problems, the PET resin method of the prior art has been disclosed to change the use of a titanium-based polycondensation catalyst in place of the lanthanide-based polycondensation catalyst, and the obtained PET resin actually improves the occurrence of the melt-spinning process. The phenomenon of silk. However, the disadvantage of using a titanium-based polycondensation catalyst is that the PET resin produced has a problem of yellowish color tone, and the PET polyester fiber produced is obviously not high in commercial value because of the yellowish hue.

In order to improve the problem that the use of a titanium-based polycondensation catalyst causes a yellowish color of the PET resin, the conventional PET resin process further discloses the use of a phosphorus-based stabilizer to stabilize the titanium-based polycondensation catalyst. For example, US Publication No. 2006/0014920 discloses the use of a mixed state catalyst to improve the yellowing of the PET resin color. The mixed catalyst comprises a reaction product of tetrabutyl titanate (TBT), tetrabutyl titanate (TBT) and bismuth phthalate, and triethyl phosphonoacetate (TEPA). Three ingredients.

The Japanese Patent Publication No. 2005-015630 also discloses the use of a mixed state catalyst to improve the yellowish color of the PET resin. The mixed catalyst is prepared by first forming a chelated titanium compound with titanium tetraisopropoxide and citric acid, and then converting the chelated titanium compound with phosphoric acid to form a phosphorus compound chelated titanium. catalyst. Next, the above-prepared phosphorus-chelating chelate titanium-based catalyst is further added with cobalt acetate, manganese acetate, and a phosphorus compound having a six-membered ring or more to prepare the mixed catalyst.

Further, in the prior art, in order to improve the gloss of the PET polyester fiber, titanium oxide (TiO ₂ ) is used as a fiber matting agent. Therefore, a titanium oxide (TiO ₂ ) additive having no catalyst action is added during the production of the PET resin. However, if the PET resin is obtained by using a titanium-based polycondensation catalyst, and the problem of yellowing the color of the PET resin is solved, and a phosphorus-based stabilizer is added to stabilize the titanium-based polymerization catalyst, the melt-spinning is performed. In the process of producing PET polyester fiber, the phosphorus stabilizer used in the PET resin causes the agglomeration of titanium dioxide (TiO ₂ ), which in turn affects the quality of the PET polyester fiber.

In view of the above, an object of the present invention is to overcome the problems of hue and gloss of the above-mentioned PET polyester fiber, and to disclose the use of an inorganic titanium-magnesium catalyst and a small amount of dye to prepare a PET resin. Such a PET resin can eliminate the problem of yellowing of the color of the PET resin because the inorganic titanium-magnesium catalyst is used, and the phosphorus-based stabilizer can be omitted, and a small amount of the dye can be used in combination. In particular, the PET resin does not contain a ruthenium-based catalyst and a phosphorus-based stabilizer, and does not cause a filament breakage during the melt-spinning process, nor does it cause agglomeration of titanium dioxide (TiO ₂ ), so that PET polyester is obtained. The hue and luster of the fiber are good.

The PET resin of the present invention is prepared by the following method:

a. Using terephthalic acid and ethylene glycol as raw materials, after the first direct esterification reaction, adding inorganic titanium-magnesium catalyst, blue dye, red dye and titanium dioxide (TiO ₂ ), and then completing the second stage Polycondensation reaction to obtain a PET resin having an intrinsic viscosity of 0.5 to 0.7 dl/g;

b. The inorganic titanium-magnesium catalyst is added in an amount of 30 to 150 ppm based on the PET resin, wherein the effective titanium amount is 2 to 10 ppm;

c. The amount of blue dye injected is between 1 and 5 ppm based on the PET resin;

d. The amount of red dye injected is between 1 and 3 ppm based on the PET resin;

e. The amount of titanium dioxide (TiO ₂ ) injected is 0 to 4 wt% based on the PET resin;

The inorganic titanium-magnesium catalyst to be injected may be selected from a granular titanium-magnesium catalyst having a particle diameter of 0.1 to 1.0 micrometers (μm), and the titanium element content is 1 to 20% by weight, wherein the titanium element is a molar element of magnesium. The ratio is between 0.005 and 1, preferably from 0.01 to 0.2. The PET resin of the present invention and the PET polyester fiber produced thereof have environmental protection value because they do not contain heavy metals and do not cause heavy metal pollution to the environment.

The PET resin of the present invention is free of barium heavy metals and is prepared by the following method:

a. using a diacid component and a diol component as a raw material, preferably using terephthalic acid and ethylene glycol as raw materials, after the first direct esterification reaction, adding an inorganic titanium-magnesium catalyst, blue dye, red The dye and titanium dioxide (TiO ₂ ) are further subjected to the second stage polycondensation reaction to obtain a PET polymer having an intrinsic viscosity of 0.5 to 0.7 dl/g, and then the PET polymer is rapidly cooled in cooling water and cut into PET resin. ;

b. The amount of the inorganic titanium-magnesium catalyst to be injected is 30 to 150 ppm based on the PET resin, wherein the effective titanium amount is 2 to 10 ppm;

c. The blue dye to be injected may be selected from Blue 104, and the added amount is between 1 and 5 ppm based on the PET resin;

d. The red dye to be injected may be Red 195, and the added amount is between 1 and 3 ppm based on the PET resin;

e. The amount of titanium dioxide (TiO ₂ ) to be injected is between 0 and 4 wt% based on the PET resin.

In the above method for producing a PET resin, the obtained PET resin can be classified into a full-light PET resin, a photo-PET resin, a semi-light PET resin, and a blunt PET resin depending on whether or not titanium dioxide is added and the amount thereof is added. Among them, the all-light PET resin does not contain titanium dioxide, the photo-PET resin contains 0.01 to 0.1 wt% of titanium dioxide, the semi-gloss PET resin contains 0.2 to 0.4 wt% of titanium dioxide, and the obtuse PET resin contains 1 to 4 wt% of titanium dioxide.

In the above method for producing a PET resin, the diacid component may be selected from the group consisting of pure terephthalic acid, iso-phthalic acid, succinic acid, glutaric acid, and One of a group consisting of adipic acid, sebacic acid, and a mixture of such analogs.

In the above method for producing a PET resin, the diol component may be selected from the group consisting of ethylene glycol, diethylene glycol, 1,3-propanediol, and 1,4-butane. One of a group of alcohols (1,4-butanediol) or a mixture of such analogs.

In the above method for producing a PET resin, the inorganic titanium-magnesium catalyst used is obtained by chemical precipitation, and the preparation method comprises the following steps:

1. The magnesium chloride (MgCl ₂ ) aqueous solution is reacted with an aqueous solution of sodium hydroxide (NaOH) at 170 ° C for about half an hour, and filtered to obtain a magnesium hydroxide (Mg(OH) ₂ ) slurry aqueous solution;

2. Mixing an aqueous solution of titanium chloride (TiCl ₄ ) with an aqueous solution of sodium hydroxide (NaOH), and then adding the solution dropwise to the aforementioned Mg(OH) ₂ slurry solution, and aging the titanium dioxide to cover the magnesium hydroxide after 1 hour of aging. On the surface of the (Mg(OH) ₂ ) particles, the slurry was filtered, washed with water and dried, and then pulverized to obtain a particulate inorganic titanium-magnesium catalyst.

The obtained granular inorganic titanium-magnesium catalyst has a particle diameter of 0.1 to 1.0 micrometer (μm), and the inorganic titanium-magnesium catalyst has a titanium content of 1 to 20% by weight, and the titanium element is magnesium to The molar ratio is between 0.005 and 1, preferably between 0.01 and 0.2.

The particulate inorganic titanium-magnesium catalyst produced by the above process has the following advantages over the organic catalyst:

1. In the polycondensation reaction process of PET resin, the inorganic titanium-magnesium catalyst does not reduce the activity due to the presence of titanium dioxide; however, the organic catalyst is deactivated by the presence of titanium dioxide.

2. The characteristic of the particulate inorganic titanium-magnesium catalyst is that the titanium catalyst is uniformly distributed on the surface of the particulate magnesium hydroxide. The particulate inorganic titanium-magnesium catalyst is capable of contacting the titanium catalyst with the reactants at a maximum surface area during the polycondensation process. Therefore, in the polycondensation reaction process, the particulate inorganic titanium-magnesium catalyst achieves the same catalytic effect in a lesser amount than the use of the organic catalyst.

The concentration of the catalyst solution prepared by the granular inorganic titanium-magnesium catalyst and ethylene glycol is between 0.01% and 15% by weight.

The PET resin of the present invention can be applied to melt-spinning to obtain PET polyester fibers. In the case of melt spinning, the PET resin is first subjected to crystallization and drying so that the moisture content of the PET resin is less than 50 ppm to prevent hydrolysis of the ester particles during post-processing. The dried PET resin is placed in a screw extruder with a temperature of 260 ° C to 295 ° C, and after extrusion, it is melted and spun through a spinning assembly having a temperature of 275 ° C to 300 ° C. After melt extrusion After being cooled by the side air blower, it is oiled and squirted through the guide wire wheel, and then coiled and produced at a speed of less than 4000 m/min to produce a semi-stretched silk (POY) cake.

The PET resin of the present invention and the PET polyester fiber obtained therefrom have the following characteristics:

1. The PET resin of the present invention is prepared by using an inorganic titanium-magnesium catalyst and a small amount of blue and red dyes, and the problem of yellowing of the color of the past PET resin can be improved without adding any phosphorus stabilizer. The color tone is also quite similar compared to the PET resin produced using the lanthanide catalyst.

2. Since the PET resin of the present invention does not contain a phosphorus-based stabilizer, the absence of the phosphorus-based stabilizer inhibits the catalytic activity of the titanium-based polymerization catalyst. Therefore, a titanium-based polymerization catalyst can be added to produce a PET resin.

3. The PET resin of the present invention does not contain a ruthenium-based catalyst and a phosphorus-based stabilizer, and has good spinning properties without breaking the filament during the melt-spinning process, and does not cause the extinction of titanium dioxide (TiO ₂ ) fibers. The agent is agglomerated, so the color and gloss of the PET polyester fiber obtained are good.

4. The PET polyester fiber obtained by melt spinning using the PET resin of the present invention does not contain barium and cobalt heavy metals, and does not cause problems of heavy metal pollution to the environment.

The PET copolyester intrinsic viscosity (IV) of the following examples and the color of the PET resin were measured by the following methods.

The intrinsic viscosity (IV) analysis was measured by Ubelohde viscosity measurement at 25 ° C for phenol and tetrachloroethane in a 3:2 by weight mixed solvent.

The color of the PET ester granules was measured by a color difference meter (Spectro photo meter, TC-1800 MKII) manufactured by TOKYO DENSHOKU CO., LTD., and expressed by L/a/b value. The higher the L value measured by the color difference meter, the whiter the color of the ester granule, and the lower the L value, the darker the color of the ester granule; the higher the measured a value, the more red the color of the ester granule, and the lower the value of a, the greener the color of the granule. The higher the measured b value, the yellower the color of the ester granule, and the lower the b value, the bluer the color of the ester granule.

The spinning condition of the PET polyester fiber of the following examples was judged by the state of the foreign matter of the spinneret, the state of the broken yarn, and the appearance of the wool.

Among them, the judgment standard of the broken wire condition refers to the number of broken wires calculated in the continuous spinning process for 2 days. The appearance of the wool is checked by observing and calculating the number of filaments on the side of the 9 kg pre-stretched silk (POY) cake.

Example 1

In a 30 liter stainless steel reactor equipped with an electric heater, 12.11 Kg of PET oligomer and 3.87 Kg of ethylene glycol (EG) were added, stirred at atmospheric pressure and heated to 260 ° C to obtain distilled ethylene glycol 1.3 to 1.6. Kg and remove it. Before the polycondensation reaction, 50 ppm of an inorganic titanium-magnesium catalyst was sequentially added, wherein the effective titanium amount was 3.5 ppm, the blue dye (Blue 104) 2 ppm, and the red dye (Red 195) 1 ppm. Subsequently, evacuation was carried out to gradually reduce the pressure in the reactor to 1 mmHg or less, prepolymerization was carried out at a temperature of 270 ° C, and main polymerization reaction was carried out at a temperature of 280 ° C to obtain 11.47 kg of a copolyester. The intrinsic viscosity of this copolyester was 0.651 dl/g, and the ester grain color L/a/b = 48/-3.0/4.2.

After the obtained ester granules were crystallized and dried, they were extruded through a screw extruder and heated and melt-spun at 296 ° C. The ester granule melt was extruded through a spinneret having 72 holes and a hole diameter of 0.2 mm, and the air temperature was 23 °C and wind speed 0.55m / s side blowing cooling, through the oiling and sneezing process, and then applied at 2850 m / min speed to coil and produce semi-light semi-stretched yarn (POY) with fiber fineness of 65den / 72f.

The spinning condition of the PET polyester fiber includes the state of the foreign matter of the spinning spinneret, the state of the broken wire, and the appearance of the wool, and the results are shown in Table 1.

Example 2

The procedure of Example 1 was repeated, but before the polycondensation reaction, the additive titanium oxide (TiO ₂ ) was added in an amount of 0.35 wt% based on the PET resin. The intrinsic viscosity of the copolyester obtained was 0.648 dl/g, and the color of the ester granules was L/a/b = 74/-1.1/5.0.

After the obtained ester granules were crystallized and dried, a fiber fineness of 65 den/72f semi-light semi-stretched yarn (POY) was obtained by the procedure of Example 1.

The spinning condition of PET polyester fiber is shown in Table 1.

Comparative example 1

The procedure of Example 1 was repeated, but the catalyst subjected to the polycondensation reaction was changed to TBT in which the amount of available titanium was 6 ppm, and TEPA 217 ppm was added. The intrinsic viscosity of the obtained copolyester was 0.650 dl/g, and the color of the ester granules was L/a/b = 47/-3.0/6.9.

The spinning condition of PET polyester fiber is shown in Table 1.

Comparative example 2

Example 2 was repeated except that the catalyst was changed to TBT in which the amount of available titanium was 6 ppm, and TEPA 217 ppm and titanium oxide (TiO ₂ ) 0.35 wt% were added. The intrinsic viscosity of the obtained copolyester was 0.642 dl/g, and the color of the ester granules was L/a/b = 73/-1.5/7.5.

The spinning condition of PET polyester fiber is shown in Table 1.

Comparative example 3

Example 2 was repeated, but the catalyst was changed to 400 ppm of cerium acetate, wherein the effective amount was 162 ppm. The intrinsic viscosity of the copolyester obtained was 0.650 dl/g, and the color of the ester granules was L/a/b = 74/-3.5/4.4.

The spinning condition of PET polyester fiber is shown in Table 1.

result

After comparing the results of Example 1-2 and Comparative Example 1-3 shown in Table 1, the following conclusions can be obtained:

1. In the case where no titanium oxide (TiO ₂ ) additive was added, the color tone of the PET resin obtained in Example 1 with an inorganic titanium-magnesium catalyst was better than that of the PET resin obtained in Comparative Example 1 with a TBT catalyst.

2. When the titanium oxide (TiO ₂ ) additive was added, the color tone of the PET resin prepared in Example 2 with an inorganic titanium-magnesium catalyst was very similar to that of the PET resin obtained by the ruthenium catalyst of Comparative Example 3, and Comparative Example 2 The PET resin obtained by the TBT catalyst had a good hue.

3. The PET resin prepared by the inorganic titanium-magnesium catalyst of Example 1 and Example 2 has good spinnability during the spinning process, including: no foreign matter accumulation on the surface of the spinneret of the spinning, at 2 There is no broken wire condition and excellent appearance of the wool during the spinning process.

Claims (3)

A PET resin for melt spinning to form a PET polyester fiber, characterized in that the PET resin comprises a PET main component, a blue dye, a red dye, and a titanium dioxide (TiO ₂ ), and does not contain a heavy metal or a phosphorus component. And prepared by the following method: a) using terephthalic acid and ethylene glycol as raw materials, after the first direct esterification reaction, adding granular inorganic titanium-magnesium catalyst, blue dye, red dye and titanium dioxide, Further completing the second stage polycondensation reaction to obtain a PET resin having an intrinsic viscosity of 0.5 to 0.7 dl/g; b) injecting a granular inorganic titanium-magnesium catalyst having a particle diameter of 0.1 to 1.0 μm and having a titanium composition Covering the surface of the magnesium hydroxide particles to form a granular catalyst, the amount of which is based on the PET resin is between 30 and 150 ppm, wherein the effective titanium amount is 2 to 10 ppm, and the molar ratio of titanium to magnesium is between 0.005 and 1; The amount of blue dye injected is based on 1 to 5 ppm of PET resin; d) the amount of red dye injected is 1 to 3 ppm based on PET resin; e) the amount of titanium dioxide injected is based on PET resin 0.01~4 wt%. The PET resin according to claim 1, wherein the inorganic titanium-magnesium catalyst has a molar ratio of titanium element to magnesium element of 0.01 to 0.2. A PET polyester fiber containing no heavy metal and phosphorus component is obtained by melt spinning of a PET resin of the first application of the patent scope.