JP2002105753A - Method for producing polyester fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing polyester fibers, by which the polyester fibers can be produced in good fiber productivity in a state scarcely causing the breakage of the fibers, when spun at a high speed. SOLUTION: This method for producing the polyesters, comprising spinning a polyester at a speed of >=5,500 m/min, characterized by using a titanium compound and an antimony compound in specific amounts, respectively, as polymerization catalysts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing polyester fibers, and more particularly to a method for obtaining polyester fibers stably at a spinning speed of 5500 m / min or more.

[0002]

2. Description of the Related Art Polyester fibers represented by polyethylene terephthalate are fibers having high strength, high Young's modulus and excellent thermal dimensional stability, and are widely used for clothing, industrial materials and the like. In addition, recently, the use of high-speed spinning has made it possible to reduce the cost by eliminating the stretching and heat treatment steps conventionally required, and is becoming increasingly important. In addition, the polyester fiber obtained by high-speed spinning at a spinning speed of 5500 m / min or more has characteristics such as easy dyeability, low Young's modulus, and a very low heat shrinkage as compared with a conventional polyester fiber. .

[0003] Polyester fibers having a low heat shrinkage ratio exhibit extremely excellent properties in various applications and are suitable for improving the feeling and for producing high-quality fabrics. For example, in the case of a strongly twisted yarn, the shrinkage of the woven fabric at the time of the appearance of the grain after the woven fabric is suppressed, and the grain becomes fine and uniform, showing an excellent appearance and texture. In addition, when used as a warp yarn of a lining fabric, rough curing of the texture due to shrinkage of the fabric is suppressed even at a high temperature such as dyeing and finishing setting, and a soft texture can be maintained. Furthermore, when used as a fiber for building such as pasting on a chair or curtain, the shape is easily maintained by heat treatment or the like, and troubles during molding and deformation of joints can be minimized.

[0004] As described above, polyester fibers obtained by high-speed spinning have a low heat shrinkage, so that it is possible to produce high-order processed products having characteristics that cannot be obtained with conventional fibers.

However, while having the above excellent aspects,
There is a problem that the yarn breakage in the spinning process tends to increase as the spinning speed is increased. In addition, as compared with the conventional low-speed spinning, the influence of the occurrence of yarn breakage increases as the spinning speed increases.

That is, the yarn breakage easily spreads to the adjacent yarns, and it takes extra time to re-thread the weight that has caused the yarn breakage, and the productivity is reduced due to the yarn breakage. Is to be large. Therefore, in high-speed spinning, it is indispensable that the frequency of occurrence of yarn breakage is lower than ever before in order to ensure operational stability.

To solve such a problem, a spinning temperature,
Various spinning conditions, such as optimization of spinning conditions such as cooling conditions, a heating cylinder below the spinneret, and a spinneret have been proposed.
These methods have limitations and cannot greatly reduce the number of thread breaks. Attempts have also been made to solve this problem by improving the polymer. JP-A-56-
No. 96913, JP-A-57-42920, 4292
Nos. 1, 51814 and 51815 disclose an antimony compound and a metal carboxylate during polymerization or an esterification reaction of the antimony compound in order to suppress crystallization under molecular orientation during fiber formation in high-speed spinning. Although the method of adding separately at the time and polymerization is used,
Since the antimony compound is modified at the time of polymerization or spinning and foreign matter defects caused by antimony occur, causing yarn breakage, the yarn breakage reduction effect obtained by these methods is small.

On the other hand, JP-A-61-43653, 4772
No. 9,111358 and 239016, there is an attempt to increase spinnability by precipitating calcium phosphate in polyester to obtain a polymer exhibiting high viscosity at low shearing. In addition, foreign matter is trapped by the filter in the spinning pack during spinning, so that the spinning pressure rises greatly and shortens the life of the pack. JP-A-62-187726, 206
018, 388815 each attempt to reduce yarn breakage by adding a phosphonic acid compound during the production of polyester to react with other catalysts to form precipitated particles and improve physical properties. However, for the same reason as above, it is not possible to avoid the adverse effect of the precipitated particles.

Further, Japanese Patent Application Laid-Open Nos. 63-303113 and 303
In each of JP-A Nos. 114 and 304024, use of a polyester having a crystallization enthalpy within a specific range is described in order to obtain a high-speed spun fiber that can be deeply dyed at a lower temperature. Specifically, by using a metal compound of Group 4 of the periodic table such as germanium oxide as a polymerization catalyst,
It is indicated that the polyester is obtained. However, germanium oxide is not only expensive as a catalyst, but also degrades the thermal dimensional stability, which is an excellent property of high-speed spun fibers. This is because the germanium catalyst produces diethylene glycol as a by-product to promote the ether formation reaction, and this is copolymerized in the polyethylene terephthalate main chain, thereby lowering the crystallinity and thus increasing the shrinkage. I will let it.

[0010] As described above, at present, it is not possible to prevent yarn breakage in high-speed spinning by modifying a polymer by conventional techniques. On the other hand, a case using an antimony compound and a germanium compound in combination as a polymerization catalyst for polyester is disclosed in JP-B-47-6744.
39239, JP-B-48-1, 3707, 38477,
38478, 38479, and JP-B-49-6197. All of these are intended to improve the color tone, which is a drawback when using an antimony compound as a catalyst, and to express a special color tone, and to reduce yarn breakage in high-speed spinning and reduce shrinkage. No consideration has been given.

[0011]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made intensive studies from polymers for the purpose of stably producing polyester fibers by high-speed spinning, and have reached the production method of the present invention.

[0012]

SUMMARY OF THE INVENTION The object of the present invention is to provide a polymerization catalyst for spinning polyester at 5500 m / min or more in an amount of 0.1 to 300 p.
pm titanium compound and antimony metal content of 30 pp
It can be achieved by a method for producing a polyester fiber, characterized by using a polyester obtained by using an antimony compound of m or less.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The polyester of the present invention is a polymer synthesized from dicarboxylic acid or its ester-forming derivative and diol or its ester-forming derivative, as long as it can be used as a fiber. There is no particular limitation.

Specific examples of such polyesters include, for example, polyethylene terephthalate, polytetramethylene terephthalate, polycyclohexylene dimethylene terephthalate, polyethylene-2,6-naphthalenedicarboxylate, and polyethylene-1,2-bis ( 2
-Chlorophenoxy) ethane-4,4'-dicarboxylate, polypropylene terephthalate and the like. The present invention is suitable for the most widely used polyethylene terephthalate or a polyester copolymer mainly composed of polyethylene terephthalate.

[0015] These polyesters may contain adipic acid, isophthalic acid, sebacic acid, phthalic acid, 4,4'- as a copolymerizing component as long as the object of the present invention is not impaired.
Dicarboxylic acids such as diphenyldicarboxylic acid and ester-forming derivatives thereof, dioxy compounds such as polyethylene glycol, diethylene glycol, hexamethylene glycol, neopentyl glycol, and polypropylene glycol; oxycarboxylic acids such as p- (β-oxyethoxy) benzoic acid; The ester-forming derivative may be copolymerized.

[0016] However, when a particularly high low shrinkage fiber is required, a third by-product such as diethylene glycol is produced.
It is preferred that the components other than the components are not substantially copolymerized.

Further, the addition of other polymers such as an antistatic agent and particles such as a matting agent, a conductive agent, and ceramics are also preferably used as long as the object of the present invention is not impaired.

The present inventors have paid attention to defects in the yarn, particularly particles resulting from the catalyst, as a factor causing yarn breakage during fiber production. Among these particles, the antimony compound, which is currently most commonly used as a polymerization catalyst, generates foreign substances such as metallic antimony by undergoing a reducing action in the polymer production process, and this has an effect on the spinning properties in high-speed spinning. Thought to have an adverse effect.

Therefore, as a result of intensive studies on the reduction of foreign substances caused by the antimony compound catalyst, the spinning property in high-speed spinning is improved by using a titanium compound as a polymerization catalyst and using no or a small amount of the antimony compound. I found that.

As the titanium compound, an alkoxytitanium compound such as tetraisopropyl titanate and tetrabutyl titanate, as well as a titanium complex compound and a composite oxide containing titanium and silicon as main metals are preferably used. In particular, a titanium complex compound and a composite oxide containing titanium and silicon as main metals have good spinning properties, and also have a good color tone of the obtained fiber, which is preferable.

Examples of the titanium complex include those obtained by bonding various complexing agents to an alkoxytitanium compound as a base material. Examples of the complexing agent include hydroxycarboxylic acids such as lactic acid, glycolic acid, citric acid, tartaric acid, and malic acid, glycine, bishydroxyethylglycine, hydroxyethylglycine, nitrilotripropionic acid, and carboximinodiamine. Acetic acid, carboxymethyl iminodipropionic acid, diethylenetriaminopentaacetic acid, triethylenetetramininohexaacetic acid, iminodiacetic acid,
Iminodipropionic acid, hydroxyethyliminodiacetic acid, hydroxyethyliminodipropionic acid, methoxyethyliminodiacetic acid, alanine-N-acetic acid, alanine-
N, N-diacetate, β-alanine-N-acetic acid, β-alanine-N, N-diacetate, serine-N-acetic acid, serine-N,
Aminocarboxylic acids such as N-diacetate, isoserine-N, N-diacetate, aspartic acid-N-acetic acid, aspartic acid-N, N-diacetic acid, glutamic acid-N-acetic acid, glutamic acid-N, N-diacetic acid And nitrogen-containing compounds such as aspartic acid, glutamic acid, leucine and isoleucine.

Further, among the titanium complexes, a titanium complex using a nitrogen-containing compound having two or more carboxylic acids in one molecule as a complexing agent has a large effect of improving thread breakage and has a good color tone of the obtained fiber. Is preferable. Further, a titanium complex having a nitrogen-containing compound having three or more carboxylic acids in one molecule as a complexing agent is preferable.

On the other hand, when the main metal is a composite oxide composed of titanium and silicon, the ratio of Ti to Si is not particularly limited, but the molar ratio of both metals (Ti / Si) is 20%.
When it is / 80 or more, the activity as a polymerization catalyst is high, and it becomes possible to polymerize in a small amount, so that it is preferable. More preferably, T
i / Si = 98/2 to 50/50.

The composite oxide comprising titanium and silicon is not particularly limited. For example, a coprecipitation method using an alkoxide compound having each metal element as a raw material,
It can be synthesized by a partial hydrolysis method or a coordination chemical sol-gel method. Here, the coprecipitation method is a method in which a solution having a predetermined composition containing two or more components is prepared, and a hydrolysis reaction is allowed to proceed with the composition to obtain a target composite oxide. The partial hydrolysis method is a method in which one component is previously hydrolyzed, the other component is added thereto, and the hydrolysis is further advanced. On the other hand, the coordination chemical sol-gel method is a method in which an organic polydentate ligand having a plurality of functional groups in a molecule coexists with a raw material such as a metal alkoxide and a complex is formed between the two to form a complex. The purpose is to control the rate of the decomposition reaction to obtain a binuclear oxide. The method for synthesizing such a binuclear oxide is described in, for example, Ueno et al., "Preparation of Catalyst Using Metal Alkoxide", IPC (1993), and the like.

Examples of the titanium compound used for producing the above-mentioned composite oxide include titanium isopropylate, titanium ethylate and titanium tert-butylate. Examples of the silicon compound include methyl orthosilicate, ethyl orthosilicate and the like. Examples of the organic polydentate ligand used in the case of the coordination chemical sol-gel method include, for example, ethylene glycol, 1,2-propanediol, 1,2-butanediol, 1,3-propanediol, Examples thereof include 3-butanediol and 2,4-pentadiol. Examples of the solvent for performing the reaction include methanol, ethanol, propanol, and isopropanol.

It is preferable to use a compound obtained by reacting a phosphorus compound with a titanium compound as a polymerization catalyst in the present invention in advance, since breakage during high-speed spinning is further reduced. Such a phosphorus compound is not particularly limited, but specifically, for example, phosphoric acid, trimethyl phosphate, triethyl phosphate, triphenyl phosphate, phosphorous acid, trimethyl phosphite, methylphosphonic acid, phenylphosphonic acid Benzylphosphonic acid, methylphosphonic acid methyl ester, phenylphosphonic acid ethyl ester, benzylphosphonic acid phenyl ester, phosphonoacetic acid ethyl ester and the like.

Here, the method of reacting the titanium compound with the phosphorus compound is not particularly limited, and a method of heating both compounds in a solvent such as ethylene glycol can be used.

The addition amount of the titanium compound as the polymerization catalyst in the present invention is 0.1 to 300 ppm, more preferably 2 to 2 ppm, based on the polyester in terms of titanium atom.
00 ppm, more preferably 3 to 100 ppm, particularly preferably 3 to 50 ppm. If the amount is less than 0.1 ppm, the polymerization reaction does not sufficiently proceed, and if it exceeds 300 ppm, the color tone of the obtained fiber is undesirably deteriorated.

In the present invention, as the polymerization catalyst,
An antimony compound may be used in combination with the titanium compound in order to improve the polymerization productivity, but from the viewpoint of the effect on the spinnability due to the formation of foreign substances, it is necessary to set the content to 30 ppm or less. More preferably 20 ppm or less, and even more preferably 5 ppm
ppm or less is preferable, and it is particularly preferable that the antimony compound is not substantially contained. Specific examples of the antimony compound include antimony trioxide, antimony pentoxide, antimony acetate, antimony glycolate and the like.

The polyester used in the present invention may contain a known phosphorus compound for the purpose of improving the heat resistance of the polymer. It is preferable that the phosphorus compound be contained in the polyester in an amount of from 0.5 to 400 ppm in terms of phosphorus atoms, since the heat resistance becomes good. More preferably 2-200pp
m, more preferably 3 to 100 ppm.

Further, T is used as a phosphorus atom in a molar ratio with respect to a titanium atom derived from a titanium compound used as a polymerization catalyst.
When the ratio of i / P is 0.1 to 20, the heat resistance of the polyester becomes good, which is preferable. More preferably, Ti / P =
0.2-10, more preferably Ti / P = 0.3-5
It is.

The phosphorus compound is not particularly limited, but specific examples thereof include phosphoric acid, phosphorous acid, phosphonic acid and their lower alkyl esters and phenyl esters, trimethyl phosphate, triethyl phosphate, phosphorus Examples include triphenyl acid, phosphorous acid, trimethyl phosphite, methylphosphonic acid, phenylphosphonic acid, benzylphosphonic acid, methylphosphonic acid methyl ester, phenylphosphonic acid ethyl ester, benzylphosphonic acid phenyl ester, and phosphonoacetic acid ethyl ester.

In the polyester of the present invention, an alkali metal, an alkaline earth metal, a cobalt compound or the like may be used in combination for the purpose of improving the color tone or the like within a range not impairing the object of the present invention. Of these, cobalt is preferable because the color tone of the resulting polymer and fiber is particularly good. The content of the cobalt compound is 5 to polyester in terms of metal atom.
~ 250 ppm is preferred, more preferably 5-120.
ppm, more preferably 10 to 80 ppm. Further, it is preferable that the molar ratio (Ti / Co) of the titanium atom and the cobalt atom of the titanium compound used as the polymerization catalyst is 0.3 to 20, since the heat resistance of the polyester is particularly good. The cobalt compound is not particularly limited, but specific examples thereof include cobalt chloride, cobalt nitrate, cobalt carbonate, cobalt acetylacetonate, cobalt naphthenate, and cobalt acetate tetrahydrate.

The method for producing the polymer of the present invention can be carried out by a direct polymerization method or via dimethyl terephthalate.
It can also be obtained by the so-called DMT method. In the case of production by the DMT method, it is preferable to use a manganese compound which does not easily generate foreign matters in the polyester as the transesterification catalyst.

As described above, in the present invention, it is necessary to reduce the amount of foreign substances caused by an antimony catalyst such as antimony metal generated by reduction of an antimony compound which is a polymerization catalyst generally used in the related art. This is important for obtaining a stable spinning state.

According to the study of the present inventors, it is preferable to minimize the amount of the antimony compound used as a polymerization catalyst and to strictly control the polymerization conditions (time and temperature) in order to suppress the generation of foreign matters. It is also preferable to take care that the stagnation area is as small as possible, and to perform chromium plating, Teflon (registered trademark) coating, or the like on the reaction tank, piping, or pack parts because they are effective in suppressing the generation of foreign substances.

In the present invention, it is necessary to produce a polyester obtained using the above polymerization catalyst at a high spinning speed of 5500 m / min or more. If spinning is performed at a spinning speed of less than 5500 m / min, productivity may be reduced and excellent low shrinkage yarn may not be obtained.

The term "low shrinkage yarn" used herein means a yarn having a boiling water shrinkage of 3.5% or less. In order to obtain a high-performance, low-shrink yarn, it is preferable to adopt a spinning speed of 6000 m / min or more.

Although particles can be added to the polyester of the present invention, the average particle size of the particles is preferably 2 μm or less in order to reduce yarn breakage by high-speed spinning at 5500 m / min or more. Further, the particles are stirred in a dispersion medium such as ethylene glycol with a medium such as glass beads having a diameter of 10 to 4000 times the above particle diameter, and then filtered, decanted, or other methods. It is preferable to remove the medium and coarse particles and to add them during the polyester production reaction.

In the slurry, it is preferable to use a dispersant comprising a phosphorus compound and / or ammonia or a lower amine compound in order to prevent the particles from reaggregating in the polymer.

The intrinsic viscosity of the polyester in the present invention is preferably 0.55 or more from the viewpoint of the strength of the obtained fiber.

When the polyester in the present invention is a polyester containing ethylene terephthalate as a main repeating unit, the amount of diethylene glycol by-produced in the polymerization step is preferably 1.2 wt% or less. If it exceeds 1.2 wt%, the fiber shrinkage tends to increase.

As in the present invention, in high-speed spinning at 5500 m / min or more, it is preferable to provide a foreign matter excess filter in the spinning pack from the viewpoint of preventing yarn breakage. In this case, a metal fiber nonwoven fabric filter having an absolute filtration diameter of 20 μm or less is preferably employed as the filter. Further, in order to improve the filtration accuracy, the absolute filtration diameter is more preferably 10 μm or less.

[0044]

The present invention will be described in more detail with reference to the following examples.

The physical properties in the examples were measured as follows. A. Metal content in polymer and fiber Determined by X-ray fluorescence. B. Diethylene glycol content The sample was alkali-decomposed and quantified using gas chromatography. C. Boiling water shrinkage △ SW Take a sample in a scallop and place in a temperature controlled room at 20 ° C and 65% RH.
After leaving the sample for more than an hour, a sample having a length L0 measured by applying a load corresponding to 0.9 cN / dtex of the sample was left under no tension in 98 ° C. boiling water for 15 minutes. It was left in the control room for 4 hours, and the above-mentioned load was applied again to calculate the length L1 according to the following equation.

ΔSW = (L0−L1) / L0 × 100 (%) Average particle size Light transmission centrifugal sedimentation type particle size analyzer (CP-2 manufactured by Shimadzu Corporation)
(Type). E. FIG. Coagulated coarse particles in polymer 5 mg of polymer sandwiched between two cover glasses 320
After melt-pressing to about 15 mm in diameter at ℃ and quenching,
Observation under a microscope revealed that a plurality of particles aggregated and a portion where the particle size became coarse was determined to be aggregated coarse particles.

The dispersibility of the particles was determined as follows by observing aggregated coarse particles having a size exceeding four times the average particle diameter existing in 1 mm ² .

Grade 1: Less than 10 aggregated coarse particles having a size exceeding 4 times the average particle size are less than 10 particles / mm 2 Secondary: 10 aggregated coarse particles having a size exceeding 4 times the average particle size / mm ² mm ² or more 30 / mmm ² below exists tertiary: average size of agglomerated coarse particles exceeding four times the particle diameter of 30 / mm ² to 50 pieces / mm ² lower than existing quaternary: average particle size F. Coagulated coarse particles having a size exceeding 4 times exist at least 50 particles / mm ² . Intrinsic viscosity: Measured using orthochlorophenol at a temperature of 25 ° C. G. FIG. Absolute filtration diameter This refers to the maximum particle size of the glass beads that have passed through the filter media according to the method of JIS-B8356. H. Number of yarn breaks The number of yarn breaks per ton was determined from the number of yarn breaks during spinning of 5 tons. In the case of 2 times / ton or less, it was judged that stable spinning property was excellent. I. Pack pressure rise The spin pack pressure rise from the beginning of spinning to the point of 200 kg of polymer passing amount was determined.

Examples 1 to 3 and Comparative Example 1 0.4 parts of phosphoric acid, 0.4 parts of triethylamine, 100 parts of ethylene glycol and 100 parts of a glass vial having a particle diameter of 100 μm were added to 12 parts of titanium dioxide particles having an average particle diameter of 0.35 μm. ―
150 parts into a stirrer equipped with a turbine blade,
The mixture was stirred at 2500 rpm for 3 hours and 30 minutes. After stirring,
The glass beads were separated and removed with a 400 mesh wire mesh to obtain a slurry of ethylene glycol of titanium dioxide particles. The average diameter of the titanium dioxide particles in the slurry is 0.4μ
m.

Manganese acetate tetrahydrate 0.035 was added to 100 parts of dimethyl terephthalate and 50.2 parts of ethylene glycol.
Was added, and a transesterification reaction was carried out by a conventional method.
Next, 0.009 parts of phosphoric acid is added to the obtained product (29 ppm as P), and then a polymer is obtained which gives an ethylene glycol slurry containing a titanium / silicon composite oxide (molar ratio Ti / Si = 90/10). And a polymerization reaction was carried out at a polymerization temperature of 290 ° C. for 3 hours and 5 minutes. The intrinsic viscosity of the obtained polymer was 0.67 and the amount of diethylene glycol was 0.8% by weight. The amount of titanium and the amount of phosphorus in the obtained polymer were 20 ppm and 20 ppm, respectively.

When the dispersion state of the titanium dioxide particles in the obtained polymer was observed, the aggregated coarse particles were found to be 3 particles / m 2.
m ^{2 and} was in a good dispersion state.

After drying the polymer at 160 ° C. for 4 hours, it was spun at an extruder type spinning machine at a spinning temperature of 298 ° C. At this time, a metal nonwoven fabric having an absolute excess diameter of 7 μm was used as a filter, and a 0.2 mmφ round hole was used as a base. In addition, chrome plating is applied to the polymer piping and the parts of the pack parts that come into contact with the polymer, and the air for chimney is 1μ.
m and then used. The yarn discharged from the spinneret is gradually cooled in a heating cylinder having a length of 25 cm, an inner diameter of 25 cmφ, and a temperature of 300 ° C., and then cooled and solidified by applying chimney cooling air, and after lubrication, confounding is applied. Taking over,
Winding with a winding tension of 0.19 cN / dtex, 84 denier
A 36-filament polyester fiber was obtained. The fibers were used as ground yarns, the polyester yarns were used as front yarns, and tricot pattern knitting was performed as a laser cuten to complete the finishing set. Table 1 shows the results of the appearance determination of the resulting race pattern.

As is apparent from Table 1, when the production of polyester fiber was carried out within the scope of the present invention, the number of yarn breakage,
A low-shrinkage polyester fiber can be obtained while suppressing a rise in pack pressure. In addition, the fiber had a good laser scout appearance. On the other hand, when the spinning speed is 5500
Under conditions less than m / min, a car with high shrinkage can be obtained.
In the ten appearance, since the fibers contracted, the pattern was broken.

[0054]

[Table 1]

Example 4 132 g of titanium isopropylate and 92 g of isopropyl alcohol were charged into a 1000 ml four-necked flask.
With stirring, 22.8 g of phosphoric acid was slowly added dropwise,
After stirring for 1 hour at 5 ° C., add serine-N, N-diacetic acid 5
1.3 g was added dropwise, and the mixture was further stirred at 60 ° C. for 2 hours and then cooled to obtain a transparent liquid (A).

A polyester was obtained in the same manner as in Example 1 except that the transparent liquid (A) was used instead of using the titanium / silicon composite oxide as the polymerization catalyst.

Further, high-speed spinning was performed under the same conditions to obtain a polyester fiber, and further a laser cutene was obtained. The results are shown in Table 2.

Example 5 In the preparation stage of the transparent liquid (A) of Example 4, the preparation was carried out without adding phosphoric acid to obtain a transparent liquid (B). A polymer was produced in the same manner as in Example 4 except that (B) was used instead of the transparent liquid (A), and a high-speed spinning and a lace curtain were obtained.
The results are shown in Table 2.

Example 6 A polymer was produced in the same manner as in Example 4 except that a reaction product obtained by heat treatment of titanium isopropylate and lactic acid was used instead of the transparent liquid (A) in Example 4, and a high-speed spinning was performed. Got a lace curtain. The results are shown in Table 2.

Example 7 A polymer was produced in the same manner as in Example 4 except that tetrabutyl titanate was used instead of the transparent liquid (A), and a high-speed spinning and lace curtain were obtained. The results are shown in Table 2.

Example 8 A polymer was produced in the same manner as in Example 4 except that tetrabutyl titanate and antimony trioxide were used instead of the transparent liquid (A), and a high-speed spinning and lace curtain were obtained. . The results are shown in Table 2.

Comparative Example 2 A polymer was produced in the same manner as in Example 4 except that antimony trioxide was used alone as the polymerization catalyst instead of the transparent liquid (A), and a high-speed spinning and lace curtain were obtained. Was. The results are shown in Table 2. As is clear from Table 2, when the catalyst composition, the amount of addition, etc. were within the range of the present invention, good spinning properties and good quality fibers could be obtained. Outside the range of the invention, the yarn-making properties were reduced and the yarn quality such as shrinkage characteristics was poor.

[0063]

[Table 2]

[0064]

According to the method for producing a polyester fiber of the present invention, particularly in high-speed spinning, problems such as thread breakage, which have been a problem when a conventional polymer is used, can be solved, and high productivity can be achieved.

Claims (6)

[Claims] When a polyester is spun at 5500 m / min or more, the amount of titanium atom as a polymerization catalyst is from 0.1 to 0.1.
A method for producing a polyester fiber, comprising using a polyester obtained by using a 300 ppm titanium compound and an antimony compound having an antimony metal content of 30 ppm or less. 2. The method according to claim 1, wherein the polyester does not substantially contain antimony metal. 3. The method for producing a polyester fiber according to claim 1, wherein the main metal of the titanium compound is a composite oxide comprising titanium and silicon. 4. The method for producing a polyester fiber according to claim 1, wherein the titanium compound is a titanium complex. 5. The method according to claim 4, wherein the complexing agent forming the titanium complex is a nitrogen-containing compound having two or more carboxylic acids in one molecule. 6. The titanium complex according to claim 4, wherein the titanium complex comprises a titanium atom, a phosphorus atom and a nitrogen-containing compound.
Method for producing the described polyester fiber