JPH10168653A - Polyester yarn and manufacturing method - Google Patents

Abstract

(57) [Summary] [Problem] A yarn made of high-quality polyester thick denier fiber which is excellent in uniformity without generation of loops and fluff, unevenness in fineness, and excellent in mechanical properties such as strength and elongation and dyeability. Providing Articles. SOLUTION: A polyester yarn comprising a polyester having a trans fraction of at least 50% in a crystal region in a total trans fraction by an infrared absorption method, a single yarn denier of 4.0d or more and a number of filaments of 24 or less. .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a yarn made of polyester thick denier fiber having a small fineness variation and extremely excellent yarn quality, and a polyester thick denier fiber yarn suitable as a core yarn of a multilayer structure false twisted yarn. Article.

[0002]

2. Description of the Related Art Polyester fibers are generally used after being drawn from the viewpoints of mechanical properties such as strength and elongation, dimensional stability, and other points. When the conventional polyester fibers are classified according to the manufacturing method, yarn (FOY) obtained in two steps of spinning and drawing, yarn (SDY) obtained in one step of direct spinning and drawing, and high-speed take-up at 5,000 m / min or more Yarn (DSY).

[0003] However, since the FOY process is divided into two processes, there are many problems such as a reduction in quality due to movement between processes and a reduction in production efficiency in the next process, and as a result, in terms of mass productivity. There were many difficulties such as cost. In the case of SDY, spinning and drawing are performed in a single step, so that the processability and mass productivity are excellent, but the heat treatment on the roller causes considerable breakage of the thread depending on the brand, which is a cause of winding. Further, in terms of fiber properties, shrinkage stress was generally lower than that of FOY, and the evaluation after processing was poor in swelling. Further, DSY has good processability and mass productivity, but this yarn-making method is limited in terms of application since only a low shrinkage (4 to 5%) yarn can be obtained.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a high-quality polyester excellent in uniformity without generation of loops and fluff, unevenness in fineness, and excellent in mechanical properties such as strength and elongation and dyeability. An object of the present invention is to provide a yarn made of thick denier fiber and a method for efficiently producing the yarn.

[0005]

Means for Solving the Problems In order to achieve the above object, the present inventors studied the fine structure of a polyester fiber having good yarn quality, and used a spinning method as a spinning method for expressing the structure. The polyester yarn is cooled to a glass transition temperature or lower once, and then is drawn directly in a heating zone to perform polyester spinning while producing polyester fibers at high speed. By regulating the thread-making conditions such as the hole diameter, spinning draft, distance from the die to the heating zone entrance, heating zone entrance diameter, heating zone length, etc. The present inventors have found that a polyester thick denier fiber yarn excellent in the above can be efficiently produced with good processability.

That is, the present invention comprises a polyester having a trans fraction of 50% or more in the crystal region of the total trans fraction determined by the infrared absorption method, and a single yarn denier of 4.
A polyester yarn having a filament number of 0 d or more and 24 or less, and further, a fiber-forming polyester is melt-spun from a spinneret, and the spun yarn is once cooled to a temperature equal to or lower than a glass transition point, and then heated in a heating zone. The polyester yarn is manufactured by applying an oil agent after drawing heat treatment by drawing and drawing at 4000 m / min or more. The intrinsic viscosity of the polyester is [η], the nozzle single hole area is S (mm ² ), and the spinning draft is Is V and the distance from the base to the entrance of the heating zone is L
_When the heating zone is ₁ (cm), the heating zone inlet diameter is R (mmφ), and the length of the heating zone is L ₂ (cm), the polyester is spun under the following conditions (1) to (6). This is a method for producing a yarn. 0.65 ≦ [η] ≦ 0.75 (1) 0.049 ≦ S ≦ 0.283 (2) 80 ≦ V ≦ 250 (3) 150 ≦ L ₁ ≦ 250 (4) 5 ≦ R ≦ 15 (5 ) 100 ≦ L ₂ ≦ 200 (6)

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The polyester used in the present invention is not particularly limited as long as it is a melt-spinnable polyester, and the polyester is polyethylene terephthalate, polybutylene terephthalate, or an ethylene terephthalate unit or a butylene terephthalate unit. Is a main constituent unit, and a copolyester containing a small amount of other copolymerized unit is preferable, and polyethylene terephthalate is particularly preferable.

When a copolyester mainly containing ethylene terephthalate units or butylene terephthalate units is used as the polyester, the proportion of the copolymer units in the copolyester is preferably 10 mol% or less. As aromatic dicarboxylic acids such as isophthalic acid, phthalic acid, 2,6 naphthalene dicarboxylic acid and 5-alkali metal sulfoisophthalic acid; aliphatic dicarboxylic acids such as oxalic acid, adipic acid, azelaic acid and sebacic acid; Carboxylic acid units derived from polyfunctional carboxylic acids such as acid and pyromellitic acid, or ester-forming components thereof; diethylene glycol, propylene glycol, butanethiol or ethylene glycol, polyethylene glycol, glycerin, pentaerythri It can be mentioned units derived from such Lumpur. The copolyester may contain two or more of the above copolymerized units.

Further, if necessary, a fluorescent whitening agent, a stabilizer, an antioxidant, an ultraviolet absorber, a hydrolysis inhibitor, an antistatic agent, a flame retardant, an inorganic fine particle for matting and other additives may be added to the polyester. One or more kinds may be included.

The polyester fiber constituting the polyester yarn of the present invention has a single yarn denier of 4.0 denier or more,
It is preferably at least 5.0 denier. When the single yarn denier is less than 4.0 denier, for example, when used as a core yarn of a multilayer structure false twisting yarn, a swelling feeling is obtained, but the stiffness is insufficient. The upper limit of single yarn denier is not particularly limited, but is preferably about 10 denier or less. Also, the number of filaments constituting the yarn must be 24 or less. If the number exceeds 24, single yarn denier4.
In order to maintain 0d or more, the total denier becomes too large, and it is also difficult in terms of spinning equipment. The lower limit of the number of filaments is not particularly limited, but is preferably about six. The total denier as the yarn is appropriately set in consideration of the single yarn denier and the number of filaments as described above, and the total denier as the yarn can be about 30 to 200 denier depending on the application. The invention is not so limited.

Next, the fiber structure of the polyester fiber constituting the yarn of the present invention has a ratio (B / A) occupied by the trans fraction (B) of the crystal region in the total trans fraction (A) by the infrared absorption method. ) Needs to be 50% or more. That is, in the infrared absorption method, the amorphous portion can be classified into two types, trans and gouge, by conformation analysis as shown in Table 1 below. However, the polyester constituting the yarn of the present invention has a total trans fraction (trans 50% or more, and preferably 60% or more, of CT total must be trans (CTcrys) in the crystalline region. When the trans-fraction of the crystal region is less than 50% of the total trans-fraction, the heat shrinkage stress is low, and the texture and surface feel are poor when the fabric is used.

[0012]

[Table 1]

Next, the manufacturing method of the present invention will be described.
In the production method of the present invention, the yarn of the fiber-forming polyester melt-spun from the spinneret is once cooled to a temperature equal to or lower than the glass transition point, and then is run in a heating zone and subjected to a stretching heat treatment. Winding at a take-up speed of 4000 m / min or more. The melt spinning temperature in this case is not particularly limited, and can be the same condition as that usually used for producing polyester fiber. Generally, the melt spinning temperature is (melting point of polyester + 20 ° C.) To (the melting point of polyester + 40 ° C.) (for example, generally about 280 to 300 ° C. in the case of polyethylene terephthalate).

The intrinsic viscosity [η] of the polyester used in this case is 0.65 or more and 0.75 or less, more preferably
It is 0.65 or more and 0.70 or less. In the production of thick denier fiber, [η] may be slightly higher than that of ordinary clothing fiber. When [η] is less than 0.65, the viscosity is low, so that cooling at the lower part of the nozzle during spinning becomes insufficient, which causes unevenness of fineness and variation of single yarn properties. On the other hand, if [η] exceeds 0.75, on the other hand, the viscosity becomes too high, and the unevenness of ejection from the spinneret during spinning or the spun yarn is likely to occur.

In the case of a fiber having a round cross section, the spinneret used for spinning has a hole diameter (nozzle hole diameter rmmφ) of 0.25 mmφ or more and 0.60 mm or more.
mmφ or less is desirable. Hole diameter less than 0.25mmφ or 0.60
If the diameter exceeds mmφ, the spinning draft deviates from the appropriate area, and the process condition deteriorates. And in the present invention,
Regardless of the fiber cross-sectional shape such as round cross-section or an irregular cross-section, it is important that the nozzle single hole area S (mm ²⁾ uses 0.049 mm ² or more 0.283Mm ² or less nozzles. Outside of this range, the spinning draft goes out of the appropriate region as described above, which is not preferable. The spinning draft V must be 80 or more and 250 or less using the above-mentioned die. If it is too low or too high outside this range, the process condition will be significantly deteriorated.
More preferably, it is 80 or more and 150 or less.

Next, the melt-spun polyester fiber is
Once cooled to a temperature below its glass transition temperature, preferably 10 ° C. or more below the glass transition temperature. The cooling method and the cooling device in this case are not particularly limited as long as the method and the device can cool the spun polyester fiber to the glass transition temperature or lower, but are not particularly limited. It is preferable that a cooling air blowing device is provided, and cooling air is blown onto the spun polyester fiber to cool the polyester fiber to a temperature lower than the glass transition temperature. At this time, the cooling conditions such as the temperature and humidity of the cooling air, the blowing speed of the cooling air, and the blowing angle of the cooling air to the spun yarn are not particularly limited, and the polyester fibers spun from the die are shaken. Any condition may be used as long as it can rapidly and uniformly cool the glass transition temperature or lower while keeping the glass transition temperature or less. Among them, the cooling air temperature is about 20-30 ° C, and the cooling air humidity is 20-60
%, The cooling air is blown at a speed of 0.4 to 1.0m / sec, and the spun polyester fiber is cooled with the blowing direction of the cooling air perpendicular to the spun fiber to cool the spun polyester fiber. It is preferable because the polyester fiber of the above can be obtained smoothly. In addition, when cooling is performed under the above conditions using a cooling air blowing cylinder, the length is about 80 mm with or without a slight interval directly below the spinneret.
It is preferable to arrange a cooling air blowing cylinder of about 150 cm.

Subsequently, the polyester fiber cooled to the glass transition temperature or lower is subsequently directly introduced into the heating zone and drawn. At this time, the distance L ₁ (cm) from the base to the entrance of the heating zone needs to be 150 cm or more and 250 cm or less. For thick denier fibers of the present invention, L ₁ is spun yarn of cooling after the high possibility of poor is less than 150 cm, or cause stretching unevenness in the heating zone, no stretching spots Even if
If the cooling before entering the heating zone is insufficient and the temperature is equal to or higher than the glass transition temperature, the stretching in the heating zone becomes insufficient, resulting in an unsatisfactory elongation.

On the other hand, if L ₁ exceeds 250 cm, the air resistance to the spun yarn becomes too large, so that yarn breakage is likely to occur due to yarn hooking or single yarn blowing before entering the heating zone.
More preferably, it is 150 cm or more and 200 cm or less.

The inlet diameter R (mmφ) of the heating zone is 5 mm or more and 15 mm or more.
mm or less is required. R can be appropriately selected in the above range depending on the target number of filaments of the fiber, denier of single yarn, and the like. However, when R is less than 5 mm, the resistance to the yarn is too large, and the yarn is likely to break, which is not preferable.
On the other hand, if it exceeds 15 mm, there is no problem in processability, but the amount of air brought into the heating zone increases, so that the thermal efficiency in the heating zone deteriorates, and stretching and heat fixation tend to be insufficient.
The exit diameter of the heating zone is desirably as small as possible in terms of quality. However, considering the workability of lowering the yarn at the time of yarn introduction, 8 mm to 15 mm is appropriate according to the brand such as the number of filaments.

Subsequently, the length L ₂ (cm) of the heating zone is 100 cm
At least 200cm is required. L ₂ is uniform stretching and heat the yarn traveling at high speed is difficult in the case of less than 100 cm. On the other hand, if L ₂ exceeds 200 cm, the effect on the fiber is small, but the operability of equipment is poor, which is not preferable.

The temperature of the heating zone may vary depending on the type of polyester and the like. However, if the temperature is higher than the glass transition temperature of the polyester by 40 ° C. or more, the physical properties of the obtained polyester fiber are practically satisfactory. For example, in the case of polyethylene terephthalate fiber, the temperature of the heating zone is preferably about 100 ° C. or more. The upper limit temperature of the heating zone may be any temperature that does not cause fusion between fibers, breakage of yarn, breakage of single yarn, and the like in the heating zone.

Then, an oil agent is applied to the polyester fiber drawn in the heating zone, if necessary, and then the polyester fiber is drawn at a high speed. In the present invention, it is necessary to perform the manufacturing process of the drawn polyester fiber comprising the above-described series of processes at a polyester fiber take-off speed of 4000 m / min or more, and the take-up speed is 4500 m / min or more. preferable. When the take-up speed of the polyester fiber is less than 4000 m / min, the drawing of the fiber is not sufficiently performed in the heating zone, the mechanical properties of the obtained polyester fiber are reduced, and the present invention comprising the above-described series of steps is performed. The method is not carried out smoothly, and in particular, fluctuations in the tension of the yarn in the heating zone, overheating, etc. occur, making it difficult to perform uniform stretching.

In the present invention, as long as the area of the nozzle single hole satisfies the above condition, the cross-sectional shape of the fiber is not limited.
Irregular cross sections such as polygonal, hollow, multi-lobe, array, V-shaped, and T-shaped may also be used.

[0024]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto. In addition, the physical property values in each Example and Comparative Example were measured by the following methods.

<Intrinsic viscosity [η]> The intrinsic viscosity [η] was measured at 30 ° C. in an equal weight mixed solvent of phenol and tetrachloroethane. <Strength and elongation of fiber> The strength and elongation were determined from a stress-strain curve obtained using a tensile tester manufactured by Instron. <Boiling water shrinkage ratio Wsr> Measured according to JIS-L1013. <Quantification of transformer fraction> JEOL FT-IR (JIR-5500)
And the peak area A _{988 of the 988} cm ^-1 band (crystallized band) and the peak area A _{793 of the 793} cm ^-1 band (internal standard) using a photoacoustic spectrometer manufactured by MTEX and a crystal fraction using the formula (1 ′). CTcrys were sought. _{CTcrys = {1.12 × (A 988} / A 793) + 0.092} × 100 (1 ') The 973 cm ^-1 band (trans): O-C stretchi
ng peak area A ₉₇₃ and 793 cm ^-1 band (internal standard)
From the peak area A _{793, the} total trans fraction CTtotal and the trans fraction CTamor in the amorphous phase are obtained from the equations (2 ′) and (3 ′).
I asked. CTtotal = 0.12 × (A ₉₇₃ / A ₇₉₃ ) × 100 (2 ′) CTamor = CTtotal−CTcrys (3 ′) <Uniformity of polyester fiber (Wooster spots: U%)>
Pass the yarn at a constant speed between the electrodes using a Worcester spot tester manufactured by Zellbaker (yarn speed 100 m / min, range ± 12.5
%, Chard speed 10 cm / min) Continuous measurement of the change in electric capacity in proportion to the change in cross section, the average deviation coefficient U for a certain length of yarn
% Was measured. <Evaluation of yarn production process> Good process condition (○), level of mass production now (一), mass production pear (×) <Dyeing / feel evaluation> The obtained polyester fiber yarn is used as warp and weft. A plain woven fabric was woven and subjected to ordinary weight loss dyeing and finishing to obtain a woven fabric. Knitted fabrics were also prepared and evaluated by panelists. The results were indicated as good (（), now (一), and poor (×).

Example 1 Polyethylene terephthalate ([η] = 0.65) was filled with 2 holes.
Melt spinning is performed at a spinning temperature of 295 ° C and a single-hole discharge rate of 2.32 g / min using a nozzle with 4 nozzles (nozzle hole diameter 0.25 mmφ, single hole area 0.049 mm ² ). After spraying the spun yarn at a speed of m / sec, the temperature of the yarn is reduced to 70 ° C. or less, and a length of 1.0 m, an inlet diameter of 8 mm is installed at a position 150 cm below the spinneret.
After being introduced into a tube heater with an outlet diameter of 10 mm (internal temperature 180 ° C) and stretched in the tube, the yarn coming out of the tube heater is lubricated with a crow mouth guide and 5,000 m / min through two take-off rollers. A 100d / 24f stretched polyester fiber was wound at a high speed. Tables 2 and 3 show the spinning conditions and the structural properties and weaving and knitting evaluation of the resulting fibers.

[0027]

[Table 2]

[Table 3]

Example 2 Polyethylene terephthalate ([η] = 0.65) was filled with 8 holes.
Melt spinning at a spinning temperature of 290 ° C and a single-hole discharge rate of 3.12 g / min using a die (pore diameter 0.3 mmφ, single-hole area 0.071 mm ² )
Spray the cooling air at a temperature of 25 ° C and a humidity of 60% onto the spun yarn at a speed of 0.6 m / sec to reduce the temperature of the spun yarn to 70 ° C or less.
1.0m length, 5mm inlet diameter, 10mm outlet diameter
After being introduced into a tube heater (internal temperature 200 ° C.) and stretched in the tube heater, the yarn coming out of the tube heater is lubricated in the same manner as in Example 1, and wound at a speed of 4500 m / min. 8f drawn polyester fiber was obtained. Tables 2 and 3 show the spinning conditions and the structural properties and weaving and knitting evaluation of the resulting fibers.

Example 3 Polyethylene terephthalate ([η] = 0.67) was filled with 6 holes.
Melt spinning at a spinning temperature of 290 ° C with a single hole discharge rate of 2.21 g / min using a die with a hole diameter of 0.3 mmφ and a single hole area of 0.071 mm ² , and a cooling wind of 25 ° C and 60% humidity of 0.6 m / sec. Spraying the spun yarn at the speed of
1.0m length, 5mm inlet diameter, 10mm outlet diameter
After being introduced into a tube heater (internal temperature 180 ° C.) and stretched in the tube heater, the yarn coming out of the tube heater is lubricated in the same manner as in Example 1, and wound at a speed of 4000 m / min. 6f drawn polyester fiber was obtained. Tables 2 and 3 show the spinning conditions and the structural properties and weaving and knitting evaluation of the resulting fibers.

Example 4 A yarn was produced in the same manner as in Example 3 except that the internal temperature of the tube heater was changed to 130 ° C. to obtain a 30d / 6f drawn polyester fiber. As a result, fibers with high shrinkage were formed. Table 2 shows the spinning conditions and structural properties of the resulting fibers, and the evaluation of weaving and knitting after false twisting.
The results are shown in Table 3.

Comparative Example 1 A yarn was drawn in the same manner as in Example 1 except that the intrinsic viscosity of the polymer was changed to [η] = 0.60 to obtain a 100d / 24f drawn fiber, but the process condition was not good.

Comparative Example 2 The procedure of Example 2 was repeated, except that the hole diameter of the die was 0.2 mmφ (single hole area: 0.031 mm ² ). But the process condition was not good.

Comparative Example 3 A fiber was drawn in the same manner as in Example 3 except that the spinning speed was changed to 3600 m / min to obtain a drawn fiber of 30d / 6f. The feeling was poor.

As described above, all of the fibers obtained in Examples 1 to 4 had a good condition in the spinning process, had no fineness unevenness, and had a good woven and knitted evaluation. On the other hand, in Comparative Examples 1 to 3, the process condition was not obtained or the physical properties were unsatisfactory.

Claims (3)

[Claims] 1. A polyester yarn comprising a polyester having a trans fraction of at least 50% in a crystalline region in a total trans fraction by an infrared absorption method, a single yarn denier of 4.0 d or more and a number of filaments of 24 or less. Article. 2. A fiber-forming polyester is melt-spun from a spinneret, and the spun yarn is once cooled to a temperature below the glass transition temperature, then run in a heating zone and subjected to a drawing heat treatment. In the method for producing a polyester yarn drawn at 4000 m / min or more, the intrinsic viscosity of the polyester is [η], the area of the single hole of the nozzle is S (mm ² ), the spinning draft is V, and the distance from the die to the entrance of the heating zone is L. ₁ (cm), heating zone inlet diameter R (mmφ), heating zone length L ₂ (c
When m), a method for producing a polyester yarn, comprising spinning under the following conditions (1) to (6). 0.65 ≦ [η] ≦ 0.75 (1) 0.049 ≦ S ≦ 0.283 (2) 80 ≦ V ≦ 250 (3) 150 ≦ L ₁ ≦ 250 (4) 5 ≦ R ≦ 15 (5 ) 100 ≦ L ₂ ≦ 200 (6) 3. A multilayer false-twisted yarn comprising the polyester yarn according to claim 1 as a core yarn and at least one other polyester yarn as a side yarn.