JP2011063895A - Polyester fiber and false-twisted yarn obtained from the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide partially oriented undrawn polyester fibers which are produced from a polyester mainly using a titanium catalyst, inhibit the expansion of crystal sizes in orientation crystallinity, especially hardly form the irregularity of fineness in a one step spinning process in a spinning rate region of 2,000 to 4,000 m/min, and are excellent in the dyed irregularity of drawn fibers obtained in the subsequent drawing process; and to provide a false-twisted yarn obtained from the same. <P>SOLUTION: The partially oriented undrawn polyester fibers are characterized by including a polyester composition composed of a polyester (PES), a metal atom, and a phosphonic acid compound, wherein the PES is a polyester which has an intrinsic viscosity of ≥0.55 dL/g and ≥90 mol% of whose whole repeating units are ethylene terephthalate units, having a double refractive index of 0.03 to 0.07, having a fiber structure having crystal sizes of ≤45 angstrom, having a polyester-soluble titanium atom content of 3 to 30 mmol% as Ti metal atoms per the total repeating units constituting PES, has the content of one or more metal atoms selected from the group consisting of manganese, magnesium and zinc in an amount of 10 to 1,000 mmol% per the total repeating units constituting PES, having an antimony element content of <15 mass ppm based on the polyester composition, and containing phenylphophosnic acid in a range satisfying a constant numerical expression. The false-twisted yarn is obtained from the same. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a polyester fiber. More specifically, there are few fineness spots, the enlargement of the crystal size in the orientation crystallinity is suppressed, and the polyester fiber excellent in leveling property of the drawn yarn obtained in the subsequent drawing step, and the temporary fiber obtained using the same are used. It is a twisted yarn.

  Polyethylene terephthalate is excellent in mechanical properties, chemical properties, moldability and the like, and has been used for polyester fibers for a long time. In particular, the spinning speed is 2000 to 4000 m / min. After obtaining partially oriented unstretched yarn in the region of, the false twisted yarn that has been crimped with a false twisting machine has many applications utilizing various properties such as bulkiness, texture, stretchability, etc. In order to efficiently produce a partially oriented undrawn yarn and false twisted yarn using the same, a low-cost and high-quality one has been developed in various places. On the other hand, polyethylene terephthalate generally uses an antimony compound as a polymerization catalyst. However, when this polyester is melt-spun and continuously spun into fiber for a long time, foreign matter (hereinafter simply referred to as a die) Productivity that fluff and / or yarn breakage occurs during spinning and false twisting process due to the occurrence of bending phenomenon (bending) of molten polymer flow. The problem of degradation occurs.

  In order to solve such problems, it has been proposed to use a titanium-based compound in which titanium tetrabutoxide is modified as a polyester polymerization catalyst (see, for example, Patent Document 1 and Patent Document 2). . The polyethylene terephthalate produced by such a method certainly reduces the deposit around the mouthpiece hole, and can stabilize the fiber production process.

  However, the polyester produced using the titanium-based catalyst as described above was obtained as a result of increasing the spinning speed of the fiber production process and promoting the oriented crystallization of the fiber in the brand having a fine single yarn fineness. It has the disadvantage that the quality of the fibers is difficult to stabilize. In other words, as the spinning speed increases or the single yarn fineness decreases, the degree of orientation of the fibers increases and at the same time, crystallization progresses. Is known to be very fast. If the orientation crystallization is too fast, the crystallization will proceed before the orientation has progressed sufficiently, resulting in non-uniform crystal size and poor fineness due to the spinning process at the fiber formation stage. The leveling property of a false twisted yarn that has been crimped with a false twisting machine using a partially oriented undrawn yarn also deteriorates.

  As means for suppressing fiber crystallization in the spinning process as described above, for example, a method of adding a diphenyl compound and an alkali metal salt compound has been proposed (for example, see Patent Document 3). However, this method is effective for polyethylene terephthalate using an antimony compound as a catalyst, but has little effect on polyethylene terephthalate using a titanium compound as a catalyst.

  From the above, an effective technique capable of improving the oriented crystallinity has not been obtained by many studies on non-antimony catalysts, particularly titanium catalysts, conducted so far.

Japanese Patent Publication No.59-046258 International Publication No. 03/027166 Pamphlet Japanese Patent Publication No. 08-019566

  The object of the present invention is to suppress the enlargement of crystal size in oriented crystallinity when producing a fiber using a polyester mainly produced using a titanium catalyst, in particular, the spinning speed is 2000 to 4000 m / min. A polyester fiber that has less unevenness in fineness in the one-step yarn production process in the region of, and has excellent leveling property of the drawn yarn obtained in the subsequent drawing step, and a false twisted yarn obtained using the polyester fiber It is.

  As a result of intensive studies in view of the above-described prior art, the present inventors have completed the present invention.

That is, the present invention is a polyester fiber comprising a polyester composition containing one or more metal atoms selected from the group consisting of manganese, magnesium and zinc, and phenylphosphonic acid, and the polyester constituting the polyester composition is: 90 mol% or more of all repeating units constituting the polyester are ethylene terephthalate units, antimony atom content is 15 ppm or less, intrinsic viscosity is 0.55 dL / g or more, birefringence is 0.03 to 0.07, polyester The polyester fiber is characterized in that the average crystallite size of the (010) plane and (100) plane of the fiber is 45 angstroms or less and the fineness unevenness is 1.0% or less. Moreover, this invention is such a polyester fiber, Comprising: The polyester soluble titanium atom content in this polyester composition is 3-30 mmol% as a Ti metal atom with respect to all the repeating units which comprise polyester, The content of one or more metal atoms selected from the group consisting of manganese, magnesium and zinc is 10 to 1000 mmol% with respect to all repeating units constituting the polyester, and the phenylphosphonic acid is represented by the following formula (1 The polyester fiber according to claim 1, which is contained in the polyester composition within a range satisfying the above.
0.8 ≦ P / M ≦ 2.0 (1)
[In the above formula (1), P is the total molar amount of phenylphosphonic acid relative to all repeating units constituting the polyester in the polyester composition, M is a manganese atom and magnesium for all repeating units constituting the polyester in the polyester composition Represents the total molar amount of atoms and zinc atoms. ]

［上記一般式（Ｉ）中、Ｒ_１は、２〜１０個の炭素原子を有するアルキル基またはフェニル基を表し、ｐは１〜３の整数を表す。］

［上記一般式（ＩＩ）中、ｎは２〜４の整数を表す。］
最後にそれらのポリエステル繊維を仮撚り加工してなる仮撚加工糸が本発明に該当し、これによって上記の課題が解決できる。 Further, the titanium compound containing a polyester-soluble titanium atom contained in the polyester composition is a compound represented by the following general formula (I) or a compound represented by the following general formula (I) and the following general formula (II): The polyester fiber according to claim 1 or 2, which is a compound formed by reacting with an aromatic polyvalent carboxylic acid or acid anhydride represented by

[In the above general formula (I), R ₁ represents an alkyl group having 2 to 10 carbon atoms or a phenyl group, and p represents an integer of 1 to 3. ]

[In said general formula (II), n represents the integer of 2-4. ]
Finally, false twisted yarns obtained by false twisting these polyester fibers correspond to the present invention, whereby the above-mentioned problems can be solved.

  According to the present invention, a polyester fiber in which oriented crystals are suppressed can be obtained even if the polyester obtained using a titanium catalyst is spun under conditions for obtaining a normal polyester partially oriented undrawn yarn. As a result, high-quality fibers can be stably produced by subsequent yarn processing operations. That is, the adhesion and deposition of foreign matter (hereinafter sometimes simply referred to as base foreign matter) around the mouthpiece hole when trying to continuously melt spin and fiberize using a titanium catalyst for a long time is greatly suppressed, The production yield can be improved by suppressing defects such as fuzz and / or yarn breakage in the spinning and false twisting processes. Furthermore, since the fineness unevenness of the polyester fiber is small, it is possible to improve the leveling property of the processed yarn obtained in the false twisting drawing process, and it is possible to improve the processability of the fiber production process and reduce the cost. It becomes.

The present invention will be described in detail below.
The polyester in the present invention is a polyester in which 90 mol% or more of all repeating units constituting the polyester are ethylene terephthalate units. When there are few ethylene terephthalate units, mechanical properties, such as tensile strength, may fall. Preferably 95 mol% or more is an ethylene terephthalate unit. The polyester fiber in the present invention needs to have an intrinsic viscosity of 0.55 dL / g or more. If the intrinsic viscosity is less than 0.55 dL / g, the mechanical properties such as tensile strength are similarly lowered, and it cannot be used for applications such as fibers. More preferably, 95 mol% or more is ethylene terephthalate unit, and the intrinsic viscosity is 0.60 dL / g or more. In addition, the intrinsic viscosity of the polyester composition of the present invention may be increased by solid phase polymerization. When measuring the intrinsic viscosity, usually use an Ostwald viscometer, Ubbelohde viscometer, etc., but if the polyester composition contains particles that would interfere with the use of these viscometers, It is also possible to employ a filtration operation after dissolving in a solvent. In addition, when the intrinsic viscosity is too high, when it is used for an application in which the high intrinsic viscosity is not preferable because melt molding becomes difficult, the range of 0.55 to 0.90 dL / g is preferable, and 0.60 to 0.00. A range of 80 dL / g is more preferred.

  The polyester of the present invention may be copolymerized with other components within a range that does not affect physical properties and characteristics and within a range of 10 mol% or less of all repeating units. Examples of the copolymer component include a dicarboxylic acid component, a diol component (glycol component), and a hydroxycarboxylic acid component that are generally used in polyester. More specifically, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4′-diphenyldicarboxylic acid, 4,4′-diphenylmethanedicarboxylic acid, diphenylketone dicarboxylic acid, 4, 4'-diphenylsulfone dicarboxylic acid, succinic acid, adipic acid, azelaic acid, 1,2-propylene glycol, trimethylene glycol, heptamethylene glycol, hexamethylene glycol, diethylene glycol, dipropylene glycol, bis (trimethylene glycol), bis (Tetramethylene glycol) and triethylene glycol can be mentioned.

  The polyester fiber in the present invention has a fiber structure with a birefringence of 0.03 to 0.07 and an average crystallite size of the (010) plane and the (100) plane of the polyester fiber of 45 angstroms or less. The fineness spots (U%, normal value) are 1.0% or less. When the birefringence is 0.03 or less, the take-up speed in the spinning process is low and the productivity may not be improved. However, the orientation crystallization is very low, so the change in physical properties after winding is large, and quality control. This also leads to a decrease in productivity even in the face of difficulty. When the birefringence is 0.07 or more, the take-up speed in the spinning process is too high, and the fiber elongation becomes low, and the strength is lowered due to insufficient neck stretching in the subsequent stretching process. The birefringence of the polyester partially oriented undrawn yarn is preferably in the range of 0.03 to 0.07, and more preferably in the range of 0.04 to 0.06.

  In the case of a polyester partially oriented undrawn yarn in which the average crystallite size of the (010) plane and the (100) plane of the polyester fiber of the present invention exceeds 45 angstroms, a fiber structure is formed immediately after the polymer is discharged immediately below the spinneret. At this stage, the crystallite size grows too rapidly, and the spinning tension unevenness at the stage where the fiber diameter is determined by cooling and solidification becomes large. As a result, the fineness unevenness (U%, normal value) is 1. It becomes a fiber with large fineness spots exceeding 0%. It is important that the fineness unevenness (U%, normal value) is 1.0% or less, and the polyester partially oriented undrawn yarn having a fineness of 1.0% or less exhibits a stretching tension with little variation in the subsequent stretching process. As a result, it is possible to obtain a drawn yarn having excellent levelness. Particularly in recent years, in order to express the soft texture of the fabric, the number of high-count multifilaments having 72 or more filaments has been increasing, and in order to maintain the uniformity of the fibers of these standards. It is important that the fineness unevenness (U%, normal value) is 1.0% or less, more preferably 0.90% or less. Moreover, when manufacturing the polyester fiber of this invention with the manufacturing method mentioned later, it may become a partially oriented yarn.

  In the polyester fiber of the present invention, an antimony compound is generally used as a polymerization catalyst used in the production of the polyester constituting the fiber, but the polyester composition of the present invention is contained in the polyester composition. The amount of antimony element to be contained must be 15 mass ppm or less. When the content of the antimony element in the polyester composition exceeds 15 ppm by mass, the antimony compound adheres to the periphery of the die as a foreign substance particularly in the spinning process, which is not preferable. The amount of antimony element in the polyester composition is preferably 10 mass ppm or less, more preferably 5 mass ppm or less.

  The manufacturing method of the polyester composition which comprises the polyester fiber in this invention uses the manufacturing method generally known. That is, first, a method in which an aromatic dicarboxylic acid component such as terephthalic acid is directly esterified with a glycol component such as ethylene glycol, or a lower alkyl ester of an aromatic dicarboxylic acid component such as dimethyl terephthalate and a glycol component such as ethylene glycol. A glycol ester of an aromatic dicarboxylic acid and / or a low polymer thereof is produced by, for example, a method of subjecting to a transesterification reaction in the presence of a transesterification reaction catalyst. Then, the reaction product is heated under reduced pressure in the presence of a polymerization catalyst and subjected to a polycondensation reaction until a predetermined degree of polymerization is obtained, whereby a target polyester is produced. Preferred examples of the transesterification reaction catalyst described above include manganese compounds, magnesium compounds, zinc compounds, and titanium compounds.

  In the polyester composition constituting the polyester fiber of the present invention, one or more metal atoms selected from the group consisting of manganese, magnesium and zinc are added in an amount of 10 to 1000 with respect to all repeating units constituting the polyester. It is preferable to contain in the range of millimol%. That is, in the case of using a transesterification catalyst, if these metal compounds are used as a transesterification reaction catalyst, not only the object of the present invention can be achieved but also the use as a catalyst is efficient. These metal atoms preferably have a divalent valence.

  On the other hand, in a method of directly esterifying an aromatic dicarboxylic acid component such as terephthalic acid and a glycol component such as ethylene glycol, a transesterification catalyst or a catalyst for the direct esterification reaction is not necessary. In order to express the effects of the invention, one or more metal components of manganese, magnesium, and zinc are intentionally included in a range of 10 to 1000 mmol% with respect to all repeating units constituting the polyester. is required.

  When the content of these metal elements is less than 10 mmol%, the effects of the present invention cannot be fully exhibited. When the content exceeds 1000 mmol%, these metal compounds form coarse particles. For example, it is not desirable because it becomes a foreign matter when the polyester is produced and remarkably deteriorates the moldability. The total content of these metal elements is preferably 20 to 500 mmol%, more preferably 30 to 100 mmol%.

  Manganese, magnesium, and zinc contained in the polyester composition of the present invention are added as compounds containing respective metal atoms in any of the production steps of the polyester composition. The manganese compound, magnesium compound, and zinc compound to be added are not particularly limited as long as they are organometallic compounds, but aliphatic monocarboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, valeric acid or stearic acid. Salts, aliphatic dicarboxylates such as oxalic acid, malonic acid or succinic acid, aromatic carboxylates such as benzoic acid, phthalic acid, isophthalic acid or terephthalic acid, or glycolic acid, lactic acid, malic acid, tartaric acid, citric acid Alternatively, hydroxycarboxylates such as hydroxybenzoic acid are preferably used, and acetate is most preferably used.

Moreover, it is necessary to contain the phenylphosphonic acid in the range of following Numerical formula (1) in the polyester composition which comprises the polyester fiber of this invention.
0.8 ≦ P / M ≦ 2.0 (1)
[In the above formula (1), P is the total molar amount of phenylphosphonic acid relative to all repeating units constituting the polyester in the polyester composition, M is a manganese atom and magnesium for all repeating units constituting the polyester in the polyester composition Represents the total molar amount of atoms and zinc atoms. ]

  When P / M shown by the mathematical formula (1) is less than 0.8, the metal compound concentration M becomes excessive, and the excess metal atom component promotes thermal decomposition of the polyester, the polyester composition, and the polyester fiber, thereby improving thermal stability. This is not preferable because it significantly deteriorates. On the other hand, when P / M exceeds 2.0, the phenylphosphonic acid is excessive, and excessive phenylphosphonic acid significantly inhibits the polymerization reaction of the polyester, which is not preferable. Preferably, P / M is 0.9 to 1.8.

  In the polyester composition constituting the polyester fiber of the present invention, the content of the polyester-soluble titanium element is preferably 3 to 30 mmol% as Ti metal with respect to all repeating units constituting the polyester. It is preferable that the compound containing titanium element is added as a catalyst in the polyester production process. Here, the polyester-soluble titanium element does not include an inorganic titanium compound such as titanium dioxide added for the purpose of matting, and is an organic titanium compound ordinarily used as a matting agent. An organic titanium compound contained as an impurity in titanium. The content of the polyester-soluble titanium element is preferably 4 to 20 mmol% as a Ti metal, more preferably 4 to 15 mmol%, based on all repeating units constituting the polyester. .

  When the content of the titanium element soluble in the polyester is less than 3 mmol% as the Ti metal with respect to all the repeating units constituting the polyester, other metal components such as manganese atom, magnesium atom and zinc atom, and phosphonic acid component Combined with the interaction, the effects of the present invention cannot be realized. On the other hand, when it exceeds 30 mmol%, thermal degradation and thermal decomposition tend to be promoted, and the intrinsic viscosity of the polyester during heating, melting, etc. is significantly reduced, which is not preferable.

  The organic titanium compound containing the polyester-soluble titanium element is preferably a titanium complex compound, more specifically, tetraalkoxytitanium or tetraphenoxytitanium having an alkyl group having 1 to 10 carbon atoms, hexaalkyldioxide. Examples include titanate or octaalkyltrititanate. Examples of specific compounds of tetraalkoxytitanium include tetraethoxytitanium, tetraisopropoxytitanium, tetra-n-propoxytitanium, and tetra-n-butoxytitanium. Preferred examples of the other titanium compounds include tetraphenoxy titanium, hexabutyl dititanate, and octabutyl trititanate.

  Other titanium complex compounds include titanium lactate, titanium acetate, tetrakisacetylacetonatotitanium, tetrakis (2,4-hexanedionato) titanium, tetrakis (3,5-heptanedionato) titanium, bisacetylacetonatodimethoxytitanium, bisacetyl Acetonatodiethoxytitanium, bisacetylacetonatobis (n-propoxy) titanium, bisacetylacetonatodiisopropoxytitanium, diacetylacetonatodibutoxytitanium, titanium dihydroxybisglycolate, titanium dihydroxybislactate, titanium dihydroxybis (2 -Hydroxypropionate), dimethoxybis (triethanolaminato) titanium, diethoxybis (triethanolaminato) titanium, diisopropoxybis (triethanol Minato) titanium, di-n-propoxy-bis (triethanolaminato) titanium or dibutoxybis (triethanolaminato) can be exemplified preferably titanium. These compounds can be used as a polymerization catalyst during the production of the polyester.

  Furthermore, as the titanium compound containing a polyester-soluble titanium element used in the present invention, a compound represented by the following general formula (I), or a compound represented by the general formula (I) and an aromatic represented by the following general formula (II): The use of a product obtained by reacting a polyvalent carboxylic acid or an anhydride thereof can also be preferably mentioned.

［上記一般式（Ｉ）中、Ｒ_２は、２〜１０個の炭素原子を有するアルキル基またはフェニル基を表し、ｐは１〜３の整数を表す。］

［上記一般式（ＩＩ）中、ｎは２〜４の整数を表す。］

[In the general formula (I), R ₂ represents an alkyl group having 2 to 10 carbon atoms or a phenyl group, and p represents an integer of 1 to 3. ]

[In said general formula (II), n represents the integer of 2-4. ]

The tetraalkoxide titanium and / or tetraphenoxide titanium represented by the general formula (I) is not particularly limited as long as R ₂ is an alkyl group and / or a phenyl group, but tetraisopropoxy titanium, tetra-n- Propoxy titanium, tetra-n-butoxy titanium, tetraethoxy titanium, tetramethoxy titanium, tetraphenoxy titanium and the like are preferably used. In addition, the aromatic polyvalent carboxylic acid represented by the general formula (II) to be reacted with the titanium compound or the anhydride thereof includes phthalic acid, trimellitic acid, hemimellitic acid, pyromellitic acid or an anhydride thereof. Preferably used. When reacting the above titanium compound with an aromatic polyvalent carboxylic acid or anhydride thereof, dissolve the aromatic polyvalent carboxylic acid or part or all of the anhydride in a solvent, and drop the titanium compound into this. And may be allowed to react at a temperature of 0 to 200 ° C. for 30 minutes or more. The reaction product thus obtained can also be used as a polymerization catalyst in the production of polyester.

  The amount of the titanium compound used as the polymerization catalyst is not particularly limited, but is preferably in the range of 3 to 30 mmol% as a Ti metal atom with respect to all repeating units constituting the polyester as described above. A more preferable usage amount is as described above. Moreover, the catalyst which consists of these titanium compounds can be used simultaneously not only as a polymerization catalyst but also as a transesterification reaction catalyst. Among the above-described polymerization catalysts, particularly when a titanium compound is used as the polymerization catalyst, the effects of the present invention can be particularly exerted. However, the titanium compound used as the polymerization catalyst is more preferably the above-described general formula ( II), or a product obtained by reacting a compound represented by the general formula (II) with an aromatic polycarboxylic acid represented by the following general formula (III) or an anhydride thereof. .

  In the present invention, as the polymerization catalyst used in producing the polyester, it is also preferable to use any one or more of a germanium compound and an aluminum compound in addition to the titanium compound as described above. Here, it does not specifically limit as a germanium compound and an aluminum compound, A general thing is mentioned as a polymerization catalyst of polyester. For example, germanium dioxide or germanium tetraalkoxide, aluminum acetylacetonate and the like can be mentioned. Among these, germanium dioxide, aluminum acetylacetonate and the like are particularly preferably selected.

  The polyester composition of the present invention contains a small amount of additives as necessary, for example, a lubricant, an antioxidant, a solid phase polymerization accelerator, a color adjuster, an optical brightener, an antistatic agent, an antibacterial agent, an ultraviolet absorber, It may contain a light stabilizer, a heat stabilizer, a light shielding agent, a matting agent, or the like. As the color adjusting agent, in order to suppress the yellowness of the appearance of the polyester, it is preferable to add a blue color adjusting agent or a purple color adjusting agent individually or simultaneously.

  There is no particular limitation on the production method for producing the polyester partially oriented undrawn yarn of the present invention, and conventionally known melt spinning methods are used. For example, it is preferable to produce the dried polyester composition by melt spinning in the range of 270 ° C. to 300 ° C., and the spinning speed can be 2000 to 4000 m / min. In order to reliably achieve the effects of the present invention, the following spinning method can be employed. Moreover, there is no limitation in particular as a manufacturing method when manufacturing the false twisting yarn of this invention, A conventionally well-known false twisting method is used.

  There is a method for producing the polyester fiber of the present invention so as to satisfy the requirements of the plurality of parameters as described above. In order to make the birefringence and the like within this numerical range, the polyester composition as described above is used. It is preferable to employ melt spinning by the following method. The melt spinning in the polyester fiber of the present invention uses a normal polyester melt spinning machine equipped with a melt extruder (screw extruder), and the above-mentioned polyethylene terephthalate-based polyester at a normal polyester melt spinning temperature (270 to 310 ° C.). It is melted, discharged from a spinneret, cooled and solidified, and is taken up at a speed of 2000 to 4000 m / min while applying an oil with a rotating roller or a metering nozzle type oiling device. When the spinning speed is less than 2500 m / min, the birefringence of the polyester partially oriented undrawn yarn obtained is less than 0.03, and drawing false twisting becomes difficult. When the birefringence exceeds 0.06, the strength and elongation of the drawn false twisted yarn from the polyester partially oriented undrawn yarn are lowered to a practical range or less. As described above, according to the present invention, a polyester uncoated polyester having a molecular orientation degree of 0.03 to 0.06 in terms of birefringence, having a favorable color tone and continuously having a favorable color tone and a low quality unevenness over a long period of time. A drawn yarn (partially oriented yarn) can be produced.

  Further, in order to bring the crystallite size and fineness within the above-mentioned range of values, as described above, using a polyester composition containing a certain amount of phenylphosphonic acid and a specific type of metal atom as described above. It is preferable to spin. Among them, it is particularly important that the polyester immediately after discharge is cooled and solidified to become a fiber structure. First, the polyester after discharge passes through a 30 to 200 mm zone maintained at an ambient temperature of 150 to 300 ° C. However, it is necessary to suppress the rapid growth of the crystallite size. Next, it is the relationship between the polyester discharge speed when discharged from the die and the speed (spinning speed) for taking it out, and the draft value (take-up speed (spinning speed) / discharge speed) is 100 to 600. is important. When the draft value is 600 or more, the cooling and solidification of the fiber is actively progressed, so that the effect of suppressing the enlargement of the crystallite size in the present technology is not sufficiently exhibited, the crystallite size becomes 45 angstroms or more, and the fineness The plaque U% often becomes 1.0% or more. When the draft value is 100 or less, the effect of suppressing the enlargement of the crystallite size is exhibited, but since the volume of the nozzle discharge hole is too small with respect to the volume of the discharged polymer, the discharged polymer rapidly swells and the nozzle discharge As a result, the polymer oozes out around the hole and adheres as a foreign substance, thereby inducing deterioration in process passability such as yarn breakage and fluff. A preferred draft value range is 150-450.

  Also, the shape of the die used at the time of spinning is not particularly limited as long as it satisfies the above requirements including other spinning conditions, and any of circular, irregular, solid or hollow can be adopted. Furthermore, the polyester fiber of the present invention is preferably subjected to an alkali weight reduction treatment in order to enhance the texture.

  The present invention will be further described in the following examples, but the scope of the present invention is not limited by these examples. Various characteristics were measured by the following methods.

(A) Intrinsic viscosity:
A dilute solution obtained by dissolving a polyester composition chip in orthochlorophenol at 100 ° C. for 60 minutes was determined from a value measured at 35 ° C. using an Ubbelohde viscometer.

(I) Phosphorus and metal element content in the polyester composition:
The amount of phosphorus metal element in the polyester composition and the amount of metal element were obtained by heating and melting a granular polyester composition sample on a steel plate, and then preparing a test compact having a flat surface with a compression press. Using this test molded body, it was determined using a fluorescent X-ray apparatus (Model 3270E manufactured by Rigaku Corporation). About what used the titanium compound as a catalyst, after dissolving a sample in orthochlorophenol, extraction operation was performed with 0.5N hydrochloric acid. The extract was quantified using a Hitachi Z-8100 atomic absorption spectrophotometer. Here, when dispersion of titanium oxide was confirmed in the extract after extraction with 0.5 N hydrochloric acid, titanium oxide particles were precipitated using a centrifuge. Next, only the supernatant was recovered by the gradient method, and the same operation was performed. By these operations, the titanium element soluble in the polyester added as a catalyst can be quantified even if the sample contains titanium oxide. Moreover, when content was less than the measurement limit of less than 1 ppm, it described as "ND".

(C) Polyester repeating unit, chemical structure of contained compound A polyester composition sample was dissolved in a deuterated trifluoroacetic acid / deuterated chloroform = 1/1 mixed solvent, the precipitate was removed by filtration, and the resulting solution was removed. A nuclear magnetic resonance spectrum ( ¹ H-NMR) was measured using JEOL A-600 superconducting FT-NMR manufactured by JEOL Ltd. The chemical structure of the repeating unit of the polyester was identified from the spectrum pattern according to a conventional method. Further, methanol was added to the polyester composition solution to precipitate the polyester component, and then the supernatant liquid was concentrated and subjected to nuclear magnetic resonance spectrum analysis to identify the chemical structures of the titanium compound and the phosphonic acid compound.

(D) Tensile strength and fineness of fiber:
Measurement was performed in accordance with the method described in JIS L1013.

(E) Birefringence of fiber It calculated | required from the retardation of the polarization observed on the surface of a fiber using an optical microscope and a compensator. The birefringence is used as an index value of the fiber orientation, and the larger the birefringence value, the more the orientation is advanced.

(F) Crystallite size of polyester fiber The crystallite size of polyester fiber was determined by wide-angle X-ray diffraction method using D8 DISCOVER with GADDS Super Speed manufactured by Brucer.
The crystallite size is determined by identifying 2Θ peaks corresponding to the (010) plane and (100) plane in the wide-angle X-ray diffraction of the polyester fiber (polyethylene terephthalate fiber). The crystallite size D in Ferraer's formula D = [(0.94 × λ × 180) / (π × (B−1) × cos Θ)]
(Here, D represents the crystallite size, B represents the half width of the diffraction peak, Θ represents the diffraction angle, and λ represents the X-ray wavelength (0.154178 nm = 1.54178 angstrom because CuKα was used).)
The average value of the crystallite sizes on both sides was calculated.

(G) Fineness spots (Fineness fluctuation value, U% (normal value))
It calculated | required with the following method.
Measuring machine: Evenes tester (Wooster tester type 4 manufactured by Twelveger Wooster)
Measurement condition mode: Normal mode Yarn speed: 200 m / min Twist number: 10,000 times / min S twist tension range: 10
Measurement fiber length: 2,000m

(H) Height of the deposit layer generated in the spinneret The polyester composition chip is melted at 290 ° C., and the polymer is discharged in a range where the spinning draft (take-off speed / discharge speed) enters from 150 to 300 from the spinneret discharge hole. The amount was set, taken up at 3000 m / min and spun for 3 days, and the height of the layer of deposits generated on the outer edge of the outlet of the die was measured. As the height of the adhered layer increases, bending tends to occur in the filamentous flow of the melted polyester composition, and the moldability of the polyester decreases. That is, the height of the deposit layer generated in the spinneret is an index of the moldability of the polyester.

(K) Judgment judgment of false twisted yarn The obtained processed yarn is made into a 100 cm long tube knitting with a 12 gauge circular knitting machine, dyed with a dye (terra seal blue GFL) at 100 ° C. for 40 minutes, and leveled. Were visually rated by the following criteria.
Level 1: Uniformly dyed and scars are hardly observed.
Level 2: Spots appearing as stripes or flickering are recognized as faint.
Level 3: Spots appearing as stripes or flickering are clearly recognized as a whole.

[Reference Example] Synthesis of titanium catalyst A Tetrabutoxy titanium was added to an ethylene glycol solution (0.2% by weight) of trimellitic anhydride in an amount of 1/2 mol with respect to trimellitic anhydride, and the mixture was heated to 80 ° C. under normal pressure in air. The reaction was continued for 60 minutes. Thereafter, it was cooled to room temperature, and the produced catalyst was recrystallized with 10 times the amount of acetone. The precipitate was filtered through filter paper and dried at 100 ° C. for 2 hours to obtain the target compound. The titanium content of the obtained compound was 11.5% by weight. This is designated as titanium catalyst A.

[Example 1]
-Manufacture of a polyester composition chip In a mixture of 100 parts by mass of dimethyl terephthalate and 70 parts by mass of ethylene glycol, 0.022 parts by mass of magnesium acetate tetrahydrate was charged into a SUS container. After the ester exchange reaction while raising the temperature from 140 ° C. to 240 ° C. under normal pressure, 0.020 parts by mass of phenylphosphonic acid was added to complete the ester exchange reaction. Thereafter, 0.011 part by mass of titanium catalyst A prepared in Reference Example (corresponding to 4.8 mmol% as Ti metal atom with respect to all repeating units constituting polyester) was used as the reaction product, and C.I. I. Solvent Blue 45 in 0.0003 parts by mass, C.I. I. 0.0002 parts by mass of Solvent Violet 36 and 1.5 parts by mass of 20 mass% ethylene glycol slurry of titanium dioxide were added and transferred to a reaction vessel equipped with a stirrer, a nitrogen inlet, a vacuum port and a distillation apparatus. The internal temperature of the reaction vessel was raised to 285 ° C., and a polycondensation reaction was performed at a high vacuum of 30 Pa or less to obtain a polyester composition having an intrinsic viscosity of 0.64 dL / g. Furthermore, it was made into a chip according to a conventional method. The results are shown in Table 1.

-Production of polyester fiber After the chip was dried at 130 ° C for 2 hours and 160 ° C for 4 hours, a partially oriented undrawn yarn of 90 dtex / 72 fil was obtained at a spinning temperature of 290 ° C and a winding speed of 2730 m / min. The draft value during spinning was calculated from the spinning speed / discharge speed. The obtained yarn was processed with a friction false twisting machine at a processing speed of 600 m / min, a processing magnification of 1.65, a non-contact false twisting heater temperature of 400 ° C./230° C., and a twisting tension (T1) by a polyurethane false twisting unit. Tension) was subjected to false twisting so that the ratio of untwisting tension (T2 tension) was 1: 0.70 to 1: 0.75 to obtain a processed yarn of 56 dtex / 72 fil. The results are shown in Table 2.

[Example 2]
In Example 1, it implemented like Example 1 except having changed the manufacturing method of the polyester fiber as follows. The results are shown in Tables 1 and 2.
-Production of polyester fiber After the chip was dried at 130 ° C for 2 hours and at 160 ° C for 4 hours, a partially oriented undrawn yarn of 90 dtex / 36 fil was obtained at a spinning temperature of 290 ° C and a winding speed of 3300 m / min. The draft value was calculated in the same manner as in Example 1. The obtained yarn was processed with a friction false twisting machine at a processing speed of 600 m / min, a processing magnification of 1.65, a non-contact false twisting heater temperature of 400 ° C./230° C., and a twisting tension (T1) by a polyurethane false twisting unit. Tension) was subjected to false twisting so that the ratio of untwisting tension (T2 tension) was 1: 0.80 to 1: 0.85 to obtain a processed yarn of 56 dtex / 36 fil. The results are shown in Tables 1 and 2.

[Examples 3 to 4, Comparative Example 1]
In Example 1, it carried out similarly to Example 1 except having changed the addition amount of magnesium acetate, phenylphosphonic acid, etc. into the quantity of Table 1. The results are shown in Tables 1 and 2.

[Comparative Example 2]
In Example 1, it implemented like Example 1 except having changed 0.020 mass part of phenylphosphonic acid into 0.042 mass part of phosphoric acid, and having changed addition amount etc. into the quantity of Table 1. The results are shown in Tables 1 and 2.

[Comparative Example 3]
A mixture of 100 parts by mass of dimethyl terephthalate and 70 parts by mass of ethylene glycol was charged with 0.077 parts by mass of magnesium acetate tetrahydrate in a stainless steel SUS314 container. The ester exchange reaction was carried out while raising the temperature from 140 ° C. to 240 ° C. under normal pressure, and then 0.068 parts by mass of phenylphosphonic acid was added to complete the ester exchange reaction. Thereafter, 0.041 part by mass of diantimony trioxide was added to the reaction product, and C.I. I. Solvent Blue 45 in 0.0003 parts by mass, C.I. I. 0.0002 parts by mass of Solvent Violet 36 and 1.5 parts by mass of 20 mass% ethylene glycol slurry of titanium dioxide were added and transferred to a reaction vessel equipped with a stirrer, a nitrogen inlet, a vacuum port and a distillation apparatus. The internal temperature of the reaction vessel was raised to 285 ° C., and a polycondensation reaction was performed at a high vacuum of 30 Pa or less to obtain a polyester composition having an intrinsic viscosity of 0.64 dL / g. Furthermore, it chipped according to the conventional method and obtained the polyester fiber similarly to Example 1. The results are shown in Tables 1 and 2.

  As is clear from Table 1 and Table 2, the polyester composition of the present invention obtained good performance, but those outside the scope of the present invention had properties of the obtained yarn (intrinsic viscosity, birefringence, Crystallization size, fineness unevenness U%, dyeing unevenness, deposit height) were insufficient.

  According to the present invention, a polyester fiber in which oriented crystals are suppressed can be obtained even if the polyester obtained using a titanium catalyst is spun under conditions for obtaining a normal polyester partially oriented undrawn yarn. As a result, high-quality fibers can be stably produced by subsequent yarn processing operations. That is, the adhesion and deposition of foreign matter (hereinafter sometimes simply referred to as base foreign matter) around the mouthpiece hole when trying to continuously melt spin and fiberize using a titanium catalyst for a long time is greatly suppressed, In the spinning and false twisting process, while improving the production yield by suppressing defects such as fuzz and / or yarn breakage, passing through the fiber production process by suppressing dyeing defects in the drawn yarn obtained in the drawing process It becomes possible to improve the cost and reduce the cost. Furthermore, since the fineness unevenness of the polyester fiber is small, it is possible to suppress the dyeing unevenness of the drawn yarn or false twisted yarn.

Claims (4)

  A polyester fiber comprising a polyester composition containing one or more metal atoms selected from the group consisting of manganese, magnesium, and zinc, and phenylphosphonic acid, wherein the polyester constituting the polyester composition is the entire polyester constituting the polyester 90 mol% or more of the repeating units are ethylene terephthalate units, the antimony atom content is 15 ppm or less, the intrinsic viscosity is 0.55 dL / g or more, the birefringence is 0.03 to 0.07, (010) of the polyester fiber A polyester fiber characterized in that the average crystallite size of the plane and the (100) plane is 45 angstroms or less and the fineness unevenness is 1.0% or less. The polyester composition has a polyester-soluble titanium atom content of 3 to 30 mmol% as Ti metal atoms with respect to all repeating units constituting the polyester, and is selected from the group consisting of manganese, magnesium and zinc Alternatively, the content of two or more metal atoms is 10 to 1000 mmol% with respect to all repeating units constituting the polyester, and the phenylphosphonic acid is contained in the polyester composition in a range satisfying the following mathematical formula (1). The polyester fiber according to claim 1.
0.8 ≦ P / M ≦ 2.0 (1)
[In the above formula (1), P is the total molar amount of phenylphosphonic acid relative to all repeating units constituting the polyester in the polyester composition, M is a manganese atom and magnesium for all repeating units constituting the polyester in the polyester composition Represents the total molar amount of atoms and zinc atoms. ] The titanium compound containing a polyester-soluble titanium atom contained in the polyester composition is represented by the compound represented by the following general formula (I) or the compound represented by the following general formula (I) and the following general formula (II). The polyester fiber according to claim 1 or 2, which is a compound formed by reacting with an aromatic polycarboxylic acid or acid anhydride.

[In the above general formula (I), R ₁ represents an alkyl group having 2 to 10 carbon atoms or a phenyl group, and p represents an integer of 1 to 3. ]

[In said general formula (II), n represents the integer of 2-4. ]   A false twisted yarn obtained by false twisting the polyester fiber according to claim 1.