JP3022998B2 - Method for producing polyester fiber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polyester fiber having a very good quality and a good winding shape only through a direct spinning and drawing step.

[0002]

2. Description of the Related Art A direct spinning / drawing method in which a spinning step and a drawing step are continuous has been industrially practically used. One of the direct spinning / drawing methods is a method using a heating tube. In this method, a melt-spun polyester yarn is cooled and solidified to a temperature equal to or lower than a glass transition temperature, then introduced into a heating zone in a heating cylinder, heated and stretched, applied with an oil agent, and wound up through a take-off roller. Is the way.

[0003] However, according to this method, the yarn is wound without sufficiently relaxing the structural distortion inside the fiber that occurs when the yarn is drawn in the heating zone, so that the bulge of the package end face and the ear height are increased. However, there is a drawback that the package cannot be taken out from the winding machine due to the tightness of the paper tube in a remarkable case. In addition, the poor winding often causes poor unwinding in the subsequent process, particularly in the weaving process.

In order to improve such disadvantages, two
Method of performing non-contact relaxation heat treatment between take-off rollers
However, for example, Japanese Patent Laid-Open Nos.
No. 29212. JP-A-2-220
In the method disclosed in Japanese Patent Publication No. 211, the non-contact
Make the yarn tension at the specified tension when performing the Japanese heat treatment
Is important. In addition, as a means of non-contact heat treatment
Therefore, it is best to use moist heat (steam) with a large heat capacity.
It is considered to be suitable.
By setting the degree, you can obtain the same effect as steam
I have. Further, Japanese Unexamined Patent Publication No. 2-229212 discloses
In the method, the relaxation heat treatment is performed at a temperature of 150 to 250 ° C.
It is preferable to perform at a relaxation rate of 0.5 to 1.0%.
The heat treatment equipment is a dry heat treatment using ordinary hot air.
The processing device is illustrated.

[0005]

SUMMARY OF THE INVENTION Indeed, Japanese Patent Laid-Open No. 2-2
Production of polyester fiber disclosed in Japanese Patent No. 29212
According to the dry heat between the take-up rollers after the stretching process
The relaxation heat treatment improves winding defects.
However, since it is a relaxation heat treatment with heated air,
The sum is insufficient and a good winding shape cannot be obtained yet. one
On the other hand, the technology disclosed in Japanese Patent Application Laid-Open No.
The method of applying the relaxation heat treatment by the team is simply non-contact drying.
Better relaxation effect than heat treatment, more reliable than dry heat
However, the effect of slightly improving the winding shape is observed. However,
Steam treatment to a lesser degree than relaxation treatment by dry heat
The unevenness of the yarn quality caused by
Has led to a decline. These are the take-off rollers
Of heat to the inside of a single fiber of yarn running at high speed
And it is difficult to provide uniform stress relaxation.
is there. Furthermore, the above-mentioned relaxation treatment method is not versatile for a wide variety of varieties. For example, when it is used for a copolyester having a large residual strain after stretching, there still remains a problem of poor winding.

SUMMARY OF THE INVENTION An object of the present invention is to provide a polyester fiber for producing a package having a good winding shape while maintaining a high quality and operation stability of the fiber when producing the polyester fiber by the direct spinning and drawing method. It is to provide a manufacturing method.

[0007]

Means and Action for Solving the Problems The present inventors have
It relates to an effective method for uniformly relieving structural strain of a yarn running at high speed to the inside of a fiber in a very short time, and furthermore, energy having excellent relaxation frequency of structural strain and excellent permeability into a polymer. As a result of detailed research on the supply source, etc., it was found that far-infrared rays are effective for efficiently relieving structural distortion inside polyester fibers in a very short time, and a relaxation heat treatment technology using far-infrared rays was found. As a result of diligent studies on, the present invention has been achieved.

That is, an object of the present invention is to provide a polyester yarn melt-spun from a spinneret once cooled and solidified to a glass transition temperature or lower, subsequently introduced into a heating zone, heated and stretched, and then applied with an oil agent. Then, in the direct spinning and drawing step of winding at 3500 m / min or more via the first and second take-up rollers, a wave number range of 1800 cm ^-1 to 60 is provided between the first and second take-up rollers.
At 0 cm ^-1 (wavelength range 5.6 μm to 16.7 μm)
The method can be solved by a method for producing a polyester fiber, wherein non-contact relaxation heat treatment is performed using far infrared rays having an average spectral infrared emissivity of 0.6 or more .

Hereinafter, the present invention will be described in further detail with reference to the accompanying drawings. FIG. 1 shows a schematic example of the direct spinning and drawing process of the present invention. In the same figure, 1 is a spinneret, 2 is a cooling zone, 3 is a heating cylinder, 4 is an oil applying device, 5
Denotes a first take-up roller, 6 denotes a confounding treatment device, 7 denotes a far-infrared ray relaxation heat treatment device, 8 denotes a second take-up roller, and 9 denotes a package wound by a winder (not shown).

The polyester yarn melt-spun from the spinneret 1 is once cooled to a glass transition temperature or lower in a cooling zone 2 and immediately led to a heating cylinder 3 where it is heated and stretched. After the yarn exiting the heating cylinder 3 is applied with the oil agent by the oil agent applying device 4, the yarn passes between the first take-up roller 5 and the second take-up roller, passes through the entanglement processing device 6 and the far-infrared mitigation heat treatment device 7, and is wound. Can be

The polyester in the present invention is mainly a polyester having ethylene terephthalate as a main repeating unit, but may be a polyester having butylene terephthalate as a main repeating unit.

The polyester whose main repeating unit is an ethylene terephthalate unit is a polyester having terephthalic acid or an ester-forming derivative thereof as a main acid component and ethylene glycol as a main alcohol component. Alternatively, those obtained by copolymerizing an alcohol component may be used.

Specific examples of the acid component include isophthalic acid,
Dicarboxylic acids such as naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenylsulfondicarboxylic acid, adipic acid, sebacic acid and 1,4-cyclohexanedicarboxylic acid or ester-forming derivatives thereof, 5-sodium sulfoisophthalic acid, 2-sodium sulfoisophthalic acid , Metal sulfonate group-containing dicarboxylic acids such as sodium 1,8-dicarboxynaphthalene-3-sulfonate,
Or an ester-forming derivative thereof, or a potassium salt, a lithium salt or the like of these compounds, or an oxycarboxylic acid such as p-oxybenzoic acid or p-β-oxyethoxybenzoic acid, or an ester-forming derivative thereof.

Further, specific examples of the alcohol component include:
Examples thereof include lower alkylene glycols such as propylene glycol and butylene glycol, 1,4-cyclohexanedimethanol, neopentyl glycol, 1,4-bis (β-oxyethoxy) benzene, and bisglycol ether of bisphenol A.

Further, as long as the polyester is substantially linear, a polycarboxylic acid such as trimellitic acid or pyromellitic acid, a polyol such as pentaerythritol, trimethylolpropane or glycerin, or a monohydric polyalkylene oxide is used. And a polymerization terminator such as phenylacetic acid.

In the present invention, once the polyester yarn melt-discharged from the spinneret 1 is cooled and solidified to the glass transition temperature or lower in the cooling zone 2, the drawing in the next heating zone is sufficiently performed so that the physical properties of the fiber are practically used. It is an essential condition to be sufficient. The subsequent heat drawing in the heating zone is performed at a temperature equal to or higher than the glass transition temperature of the fiber.However, in order to make the fiber physical properties sufficiently practical,
It is preferable to use a temperature of 100 ° C. or higher. The upper limit temperature of the heating zone is not less than the melting point of the fibers, and may be as high as possible, as long as the temperature does not substantially cause fusion between the single fibers or yarn breakage in the heating tube 3. The winding speed is 350 from the viewpoint of fiber physical properties, yarn spots, dyeing property, etc.
It is preferably at least 0 m / min.

The most important feature of the present invention is that the wave number range between the first take-up roller 5 and the second take-up roller 8 is 1800 cm.
^-1 to 600 cm ^-1 (wavelength range 5.6 μm to 16.7 μm
m) when the average value of the spectral infrared emissivity is 0.6 or more
The point is that a non-contact relaxation heat treatment is performed by a certain far infrared ray. In the direct spinning and drawing step in the present invention, the yarn introduced into the heating zone in a low-speed running state as an undrawn yarn is drawn in a non-contact manner in the heating zone, and immediately thereafter, enters a high-speed running state as a drawn yarn. After that, the liquid leaves the heating zone, is supplied with an oil agent, and is introduced into the first take-off roller 5. That is, in the fiber of the yarn introduced into the first take-off roller 5, there is a structural distortion caused by high-speed deformation from an undrawn yarn in a low molecular orientation state to a drawn yarn in a high molecular orientation state in a heating zone. Remain unmitigated. Therefore, if the yarn is wound up as it is, that is, in a state where the stress inside the fiber is large, poor winding is caused.

Examples of defective winding include a bulge (bulging of an end face of a package), an increase in the height of a package, and a failure in removing a paper tube due to tight tightening. The bulge means that the force acts as a whole in the direction of the end face of the package and the end face expands in order to wind the yarn while the internal stress of the fiber remains large. This is caused by tightening the lower package center. Paper tube pull-out failure due to tightening occurs when the residual strain inside the fiber, that is, the residual stress inside the fiber is extremely large.

In general, the residual stress inside the fiber increases as the deformation speed of the fiber increases, that is, as the take-up speed increases, and the winding defect becomes remarkable at 4500 m / min or more, particularly 5000 m / min or more. In addition, the residual stress inside the fiber during deformation also depends on the type of polyester polymer, and in the case of a copolyester whose melt viscosity is higher than the average molecular weight of the polymer, winding defects may occur even at the same take-off speed. Wake up.

In order to improve the poor winding caused by the residual stress inside the fiber, a heat treatment device is provided between the first take-up roller 5 and the second take-up roller 8, and the yarn is relaxed and heat-treated by overfeed. It is important to reduce the residual stress inside the fiber.

However, the staying time of the yarn running at 3500 m / min or more in the heat treatment apparatus is only about several milliseconds. Therefore, in order to alleviate the internal stress of the fiber within such an extremely short time, that is, to release the internal residual strain of the fiber, the energy having excellent permeability into the interior of the fiber and matching the relaxation frequency of the structural strain is required. The key is extremely important.

As a heat treatment means, for example , a usual hot air treatment equipment
When dry heat is used, the means for transferring energy from the heat treatment device to the yarn depends only on the conduction of heat by air. However, the yarn traveling at a high speed of 3500 m / min or more has a considerable accompanying airflow, and the energy received by the yarn is extremely small. Therefore, it is extremely inefficient to relax the internal stress of the yarn by the dry heat treatment within a very short time of several milliseconds, and as a result, the improvement of the winding shape is also unsatisfactory.

The heat treatment means is wet heat (steam).
In the case of using the same, it is difficult to relax the entire yarn to the inside of the single fiber within a very short time of several milliseconds for exactly the same reason. Furthermore, when steam is used, it causes troubles such as spots due to unevenness of the relaxation effect.

On the other hand, the method of performing heat treatment while bringing the yarn into contact with a hot plate or the like improves the thermal efficiency. And the fiber becomes unpractical. Therefore, it is necessary to make the heat treatment method non-contact.

In order to solve the above problems, it is the most important point in the present invention to employ a far-infrared ray as the relaxation heat treatment means, as described above. The wavelength range of infrared light, which is a type of electromagnetic wave, is from 0.75 μm to about 1000 μm at the red end wavelength of visible light, and those in the wavelength range of 5.6 μm to about 1000 μm are called far infrared rays. Far-infrared rays are also called heat rays because they have a large effect of exciting thermal motion in a substance to raise the temperature.

FIG. 2 shows an infrared absorption spectrum of the polyester. In the wave number range of 1800 cm ^-1 to 600 cm ^-1 , that is, in the wavelength range of 5.6 μm to 16.7 μm, the polyester shows significant infrared absorption. Therefore, when the polyester is irradiated with infrared rays corresponding to this wavelength range, the polyester resonates and absorbs the electromagnetic wave, the molecular vibration inside the polyester fiber is activated, the temperature inside the fiber rises, and the amorphous phase and the orientation non-alignment are increased. It helps the conformational change of the polymer chains in the crystal phase (intermediate phase), and alleviates the internal structural strain of the fiber.

Further, far infrared rays do not need to heat a medium such as air, and directly transmit energy to an object to be heated by radiation. Therefore, the inside and outside of the object to be heated are uniformly heated.

The far-infrared radiation source used in the present invention includes:
Far infrared emitting ceramic materials are preferred. Radiation characteristics of far infrared, that is, the spectral infrared emissivity curve varies depending on the firing conditions and composition of the ceramic material, in particular, 600 cm ^-1 (wavelengths ranging from the wave number range 1800cm ^-1 5.6μ
m to 16.7 μm) are preferred. Further, a ceramic material having an average spectral infrared emissivity of 0.8 or more in a frequency range is particularly preferable. FIG.
Is Examples A and B of the far infrared radiation ceramic material used in the present invention (average of 0.92 and 0.89 of the spectral infrared emissivity at 600 cm ^-1 wave number range 1800 cm ^-1)
It has been widely used as a dry heat treatment device.
5 shows a spectral infrared emissivity curve of an example C of the cast aluminum heater (the average spectral infrared emissivity in the same wave number range is 0.28). Further, 600 cm ^-1 (wavelength range 5.6 parts subjected to in FIG. 3 ///// from the wave number range 1800 cm ^-1
μm to 16.7 μm).

The far infrared ray relaxation heat treatment apparatus 7 used in the present invention
As a non-contact type, it is necessary to shorten the distance between the far-infrared radiating ceramic heater and the yarn within a range where the yarn does not contact the heater even if the running state of the yarn fluctuates slightly. Is preferred.

The temperature used in the far-infrared ray relaxation heat treatment in the present invention is not particularly limited, and may be any temperature. However, when the temperature of the ceramic heater is increased, the amount of far-infrared ray radiated from the ceramic material is increased. Therefore, it is preferable to use the polyester yarn at a high temperature within a range in which the polyester yarns do not substantially fuse with each other or generate fluff. The use of a high temperature is also preferable because, in addition to the effect of increasing the amount of radiation of far infrared rays, the conventional dry heat conduction effect is also synergistic. From the above viewpoints, the far-infrared ray relaxation heat treatment apparatus 7 of the present invention is preferably used at a temperature exceeding 250 ° C.

Further, when the present invention is carried out, it is preferable that the yarn is overheated between the first take-up roller 5 and the second take-up roller 8, that is, the relaxation heat treatment is performed while the yarn is relaxed. Regarding the overfeed rate of the yarn, since the appropriate overfeed rate varies depending on the type of the polyester polymer and the take-up speed, it is not particularly limited, but is generally 0.3 to
An overfeed rate of 3.0%, preferably 0.5-2.0% can be used.

[0032]

The present invention will be described below in detail with reference to examples. The spectral infrared emissivity curve is based on the Electro Optical Indust
ries Inc. Black body furnace ModelWS 153 500
C., and the sample was measured at the same temperature using an infrared spectrophotometer A-302 manufactured by JASCO Corporation. Bulge measured the swelling of the end face of a 5 kg wound package. In addition, the judgment of the winding shape is comprehensively judged from both the bulge and the ear height, and is determined as poor ... ×, somewhat good… △,
Good: good, very good: good.

The symbol of the relaxation heat treatment apparatus in Table 1 indicates the following apparatus. A: Far Infrared relaxation heat treatment apparatus of the present invention, however, spectral infrared emissivity curve of the ceramic material is A in FIG. 3, the average value of the spectral infrared emissivity at 600 cm ^-1 wave number range 1800 cm ^-1 is 0.92 It is. B: far infrared relaxation heat treatment apparatus of the present invention, however, spectral infrared emissivity curve of the ceramic material is a B in FIG. 3, the average value of the spectral infrared emissivity at 600 cm ^-1 wave number range 1800 cm ^-1 is 0.89 It is. C: a conventional aluminum cast dry heat relaxation treatment apparatus, the average value of the spectral infrared emissivity at 600 cm ^-1 wave number range 1800 cm ^-1 is 0.28.

(Examples 1 to 7 and Comparative Examples 1 to 3) Polyethylene terephthalate was melted and discharged from a spinneret having 72 holes at 292 ° C. in a direct spinning and stretching apparatus shown in FIG. After cooling, the mixture was introduced into a heating cylinder at 220 ° C., stretched by heating, oil was applied, and then passed through the first take-up roller and the second take-up roller of the entanglement treatment device.
Winding was performed at a speed of 00 m / min to obtain a 75d / 72f yarn. At this time, the heat treatment device, the temperature, and the overfeed ratio between the first take-up roller and the second take-up roller were as shown in Table 1. The results are shown in Table 1. Heat treatment temperature and
Same overheat rate and same dry heat
In Example 1 and Comparative Example 3 where heat treatment was performed under the conditions,
There is a large difference in the evaluation of the winding shape of the. This is the ratio
Normal aluminum casting dry heat relaxation treatment used in Comparative Example 3
In apparatus, put the wavenumber range 1800 cm ^-1 to 600 cm ^-1
Since the average value of the spectral infrared emissivity is as small as 0.28,
Insufficient relaxation heat treatment, resulting in poor winding shape
It is.

Examples 8 to 14 and Comparative Examples 4 to 6 The polyethylene terephthalates of Examples 1 to 7 and Comparative Examples 1 to 3 were copolymerized with 3% by weight of polyethylene glycol and 1% by weight of sodium 5-sulfoisophthalate. As in Examples 1 to 7 and Comparative Examples 1 to 3, except that the melt discharge temperature was changed to polyester and the melt discharge temperature was changed to 285 ° C., and a yarn of 75 d / 36 f was formed using a spinneret having 36 holes. Carried out. The results are shown in Table 1. Even in the case of this copolymerized polyester, similarly to the above-mentioned polyethylene terephthalate, even in the case of the relaxation heat treatment under the same conditions, the wave number range of 18
Flat spectral emissivity from 00 cm ^-1 to 600 cm ^-1
In Example 8 where the average value is large, the winding shape is good.
However, in Comparative Example 6 where the average value was small, the winding shape was poor.
The result was obtained.

[0036]

[Table 1]

[0037]

According to the present invention, if the far-infrared ray relaxation heat treatment method is used in the direct spinning and drawing step, it is not necessary to heat a medium such as air or water vapor, and the far-infrared ray directly radiates the traveling yarn to the running yarn by radiation. Since energy is applied and energy is uniformly given to both inside and outside of the running yarn, a much better relaxation heat treatment effect than the conventional dry heat treatment method or wet heat treatment method can be obtained. as a result,
A good winding shape can be obtained while maintaining stable operability and high yarn quality.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an example of a direct spinning and stretching apparatus used for carrying out the present invention.

FIG. 2 is a characteristic diagram showing an infrared absorption spectrum of polyester.

FIG. 3 is a comparison diagram showing a spectral infrared emissivity curve.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Spinneret 2 Cooling area 3 Heating cylinder 4 Lubricant application apparatus 5 1st take-up roller 6 Entanglement processing apparatus 7 Far-infrared relaxation heat treatment apparatus 8 2nd take-up roller 9 Package A, B Spectral infrared emissivity curve C of far infrared radiation ceramic material Spectral infrared emissivity curve of conventional aluminum cast heater

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masatoshi Sashiyama 4-1, Ushikawa-dori, Toyohashi-shi, Aichi Pref. Mitsubishi Rayon Co., Ltd. Toyohashi Works (56) References JP-A-2-229212 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) D01F 6/62 301-308

Claims (1)

(57) [Claims] 1. A polyester yarn melt-spun from a spinneret is cooled and solidified to a glass transition temperature or lower once, subsequently introduced into a heating zone, heated and stretched, and then an oil agent is applied.
350 through the first take-up roller and the second take-up roller
In the direct spinning and drawing step of winding at a speed of 0 m / min or more, a wave number range of 1 between the first take-up roller and the second take-up roller.
800 cm ^-1 to 600 cm ^-1 (wavelength range 5.6 μm to 1
The average value of the spectral infrared emissivity at 6.7 μm) is 0.
A method for producing a polyester fiber, wherein the non-contact relaxation heat treatment is performed using far infrared rays of 6 or more .