JPS59144618A - Production of polyester conjugate fiber - Google Patents

Abstract

PURPOSE:Two kinds of polyesters different in their intrinsic viscosity are mixed and taken up at a specific speed to give a side-by-side conjugate yarn with good touch, causing no yarn tighting. CONSTITUTION:The polyester of lower viscosity is set to 0.34-0.50 in its intrinsic viscosity [eta]f and the difference in the intrinsic viscosity from the higher viscosity polyester is set to 0.20-0.30 DELTA[eta]f. Then, these polyesters are mixed and taken up at a spinning speed of 4,000-5,500m/min to give the objective side-by-side type conjugate fiber. The polyester of the lower viscosity is preferably a copolyester containing 3-10mol% of a third component.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing side-pie-side type composite fibers made of polyester polymers having different intrinsic viscosities.

In particular, the object of the present invention is to provide a method for producing high-performance polyester composite crimped yarn at high speed.

Conventionally, the mainstream method for manufacturing crimped yarn has been the false twisting process, and with the recent appearance of friction false twisting units, this method has become faster than the spindle-type plate twisting method up until then. However, it is still only about 1000 m/m at most, and no significant improvement in productivity can be expected even with direct spinning processing.

On the other hand, various methods have been proposed in which the drawn yarn is preheated and then bulked with heated air (for example, Japanese Patent Publication No. 53-3517
No. 5, U.S. Pat. No. 3,729,831, U.S. Pat. No. 3,852,857). Although these methods are superior in terms of speeding up, they are inferior in bulk as processed yarns used for clothing, and because the processing method causes excessive heat shrinkage of the fibers, they cause problems such as dye spots and mechanical problems. It is inferior in physical properties (high elongation, easy to stretch).

For this reason, this technology is used to manufacture tact yarns for carpets with a large single denier and a large total denier.

On the other hand, there is a method of heat setting with an air forced nozzle after false twisting (Japanese Patent Application Laid-Open No. 53-119348, Japanese Patent Application Laid-Open No. 54-68433).
Although it has also been proposed (Japanese Patent Publication No. 2003-12101), it is difficult to process at high speeds and is not suitable for direct spinning processing.

In contrast to these methods, a method has been proposed in which a polyester composite fiber having a difference in intrinsic viscosity is spun at high speed to produce a crimped bulky yarn (Japanese Patent Publication No. 11848/1983). However, with this method, the difference in intrinsic viscosity is small, and the intrinsic viscosity itself is too high, making it impossible to obtain yarn with bulkiness and texture suitable for clothing applications.

Furthermore, a method has also been proposed in which composite spinning of different types of polymers is carried out, followed by drawing heat treatment and heating air processing (U.S. Pat. No. 4,115,989, U.S. Pat. No. 4,118).
, No. 534, Japanese Utility Model Publication No. 46-9535, Japanese Patent Publication No. 45-37576, Japanese Unexamined Patent Application Publication No. 54-42441). However, although these methods are suitable for high-speed processing, the electrical properties and mechanical properties of the crimped yarn are poor, and it is still unsuitable for use in clothing.

In addition, a method has been proposed in which composite spinning of different types of different polymers is carried out, and processing is carried out using a heated fluid after drawing heat treatment (Japanese Unexamined Patent Application Publication No. 1986-1999).
169830). This proposal has crimped bulk,
It also has good mechanical properties and can be used for clothing, but production efficiency cannot be improved due to the extremely low spinning speed and low heat elongation treatment ().

The present invention aims to solve the drawbacks of these conventional methods and obtain a crimped yarn with good crimped bulk and mechanical properties by ultra-high-speed spinning. It was based on the results of physical property research (it was created based on a new idea).

That is, in the first invention of the present application, when manufacturing a side-pie-side type composite fiber made of polyester having an intrinsic viscosity difference Δ[η]f, the intrinsic viscosity [η]f of the polyester component having a low intrinsic viscosity is reduced to 0. .34~O0S O, the intrinsic viscosity difference △[η]f between both polyester components is 0.20~0.3
0 and the spinning speed is 4,000 to 5 oon/min. When producing a side-pie-side type composite fiber, the intrinsic viscosity Cq]t of the polyester component with low intrinsic viscosity is set to 0.34 to 0.50, and the intrinsic viscosity difference Δ[η]f between both polyester components is set to 0.34 to 0.50. 20-0.30
The spinning speed was 4,000~s, soo * 7 minutes, and the spinning speed was 4,000~s, soo * 7 minutes.
'C temperature, 0.03g/d/! A method for producing a polyester composite fiber characterized by carrying out a pre-relaxation heat treatment under the following tension and then a relaxation heat treatment at 160 to 220°C, and a third invention of the present application provides a method for producing a polyester composite fiber, which is characterized by carrying out a pre-relaxation heat treatment under the following tension and then a relaxation heat treatment at 160 to 220°C. When producing a side-pie-side type composite fiber made of polyester having a polyester component having a low intrinsic viscosity, the intrinsic viscosity [η]f of the polyester component with a low intrinsic viscosity is set to 0.34 to 0.50, and the intrinsic viscosity difference Δ[η] between both polyester components is ]tff:o, 2o~
0.30 and taken at a spinning speed of 4,000 to 5,500 m 7 min, followed by a heating fluid push nozzle for 16 min.
This is a method for producing a polyester composite fiber characterized by carrying out a relaxation heat treatment at 0 to 220'C.

The polyester used in the present invention is mainly polyethylene terephthalate, but it is preferable to use copolymerized polyethylene terephthalate as the polyester component with lower intrinsic viscosity, since this will result in a higher degree of crimp.

In this case, examples of the third copolymerized component include inphthalic acid, diethylene glycol, triethylene glycol, etc., and the amount of copolymerization is preferably in the range of 3 to 10 mol%.

The basic idea of the present invention is to utilize the fact that the physical properties of the spun yarn vary significantly depending on the intrinsic viscosity [η]f of the spun yarn in ultrahigh-speed spinning. That is, according to our basic research, in the melt spinning of general polyethylene terephthalate, there is a relationship between the spinning speed and the heat shrinkage rate as shown in the figure. In the figure, the behavior of a yarn with a high intrinsic viscosity [η]f is shown by a solid line, and the behavior of a yarn with a low intrinsic viscosity [η]f is shown by a dotted line.

In the low spinning speed range of 2500 @ / 7M4 or lower (region I in the figure), for both high [η]t + low [η]'f yarns, as the spinning speed increases, the molecular orientation increases, and high [η]t + low [η]'f yarns increase.
[eta]f The heat shrinkage rate increases as the yarn increases.

Since these yarns have low strength and high elongation, they cannot be used by themselves, so they are subsequently subjected to drawing heat treatment. The density of the yarn obtained at this time is as small as bi[η]f yarn, and therefore the heat shrinkage rate becomes large. This high [η] f, low [η] f
Side-pie-side type composite fibers based on polyester having different intrinsic viscosity utilize differences in shrinkage properties of yarns, and most of the fibers proposed in the past belong to this area. - For example, there is a technique described in Japanese Unexamined Patent Publication No. 169830/1983.

However, when the spinning speed was further increased to 2,800 to 3,200, /
Surprisingly, when the area of 11111, that is, the area of ■ in the figure, there is no significant difference in the warpage of the spun yarn with crystal [ηlr, low [η]f] and the physical properties of the drawn and heat-set yarn.

That is, in this spinning speed range, it is difficult to obtain high bulkiness with composite fibers that utilize the difference in intrinsic viscosity.

For this reason, the above-mentioned Japanese Unexamined Patent Publication No. 169830/1983 states that the preferred spinning speed is 2.
000m/a.

However, what is even more surprising is that as the spinning speed is further increased (region marked ■ in the figure), the density of the spun yarn increases and the shrinkage rate of the spun yarn decreases as the spinning speed increases. 5
, will be. From this region, differences in physical properties begin to appear again between high [η]f and low [η]f spun yarns. However, in this region, the yarn density is high [*)r. becomes larger, and therefore the shrinkage rate becomes smaller. This is a phenomenon opposite to the area I in the figure.

These spun yarns have low strength and high elongation, so they require drawing and heat setting, but when heat set, both high [η]f and low [η]f yarns exhibit extremely similar high densities. , the difference in shrinkage properties disappears. If the spun yarn of the intrinsic viscosity difference side-pie-side type composite fiber is subjected to relaxation heat treatment without drawing heat centrifugation in this spinning speed range, crimp occurs. However, once a material has been heat treated under tension, even if it is subsequently subjected to relaxation heat treatment, only a very small degree of crimp structure will occur. Taking advantage of this phenomenon, it is possible to develop a crimp structure by directly performing relaxation heat treatment without stretching and heat treatment after spinning, but the resulting yarn has extremely high elongation and low strength. Because of this, it cannot withstand use.

Next, from 4000, which is even faster, s s o o, /+
In the m-region (region marked ■ in the figure), there is high density with only the spun yarn,
A product with low shrinkage and high strength that can withstand use can be obtained. Fortunately, in this region, there is a large difference in the physical properties of the two spun yarns due to the difference in intrinsic viscosity.

Based on this knowledge, when the spun yarn of the intrinsic viscosity difference side pie-side type composite fiber was subjected to relaxation heat treatment, an extremely good limp structure was obtained. However, no matter how much relaxation heat treatment was applied to the material that had once been subjected to stretching heat setting or tension heat treatment, no crimp structure was developed. This is the same phenomenon as in the area (■), and the reason is that when the composite fiber is subjected to tension heat treatment that does not form a crimp structure, crystallization proceeds in that state, eliminating the structural difference between nide and pide. 1 It is thought that it is due to the body. Furthermore, even if a crimp structure is developed first and then heat treatment is performed at a more controlled temperature, the crimp structure does not disappear and crystallization progresses further (-j
However, a morphologically stable structure can be obtained.

The present invention makes use of the above knowledge to produce a side pie-side type composite fiber with an intrinsic viscosity difference of <ooWL/m to 5500
The most significant feature is that it is spun at a spinning speed of B/min and heat-treated in a relaxed state.

When the spinning speed is further increased (region marked ■ in the figure), the spinning speed becomes low [
η]f thread density increases, and the difference between high [η]f and low [η]f thread properties disappears again.

From this, the spinning speed of the present invention is 4000 to 5 soo.
It will be clear that it is important to directly relax heat treat the spun yarn in the range of , 7 m.

Next, what was needed was that the intrinsic viscosity [η]f on the low [η]f side ranged from 0.34 to 0 in both the side, pi, and side components.
．． It must be within the range of 50.

If [η]f is smaller than 0.34, thread breakage during melt spinning and staining of the spinneret surface will occur, making stable spinning impossible. On the other hand, if it exceeds 0.50, the spinnability will improve, but the intrinsic viscosity difference Δ[η]f.

Even if the spinning speed is within the range of the present invention, the potential crimp performance of the spun yarn is reduced. The reason for this is that crystallization in the spinning stage is promoted when [η] f becomes large, and sparrow [η]
] Intrinsic viscosity on the f side [η] f is lower [η] Intrinsic viscosity on the f side [
Even if it is increased to match the increase in [η]f, [η]
When f exceeds 0.70, the tendency for crystallization to become saturated begins to be seen, and the differences in physical properties between image components begin to shrink. These two points are the reasons for determining the upper limit of low [η] f. .

The next important thing is that the difference in intrinsic viscosity between the two components [η] f is 0.
．． 20 to 0.30.

If this Δ[η]f becomes smaller than 0.20, it becomes difficult to obtain sufficient crimp performance. If it is larger than 0.30, bending of the polymer in the direction of the spinneret during spinning becomes large, resulting in extremely poor spinnability.

The polyester composite fiber obtained by this method can be made to exhibit good crimping by being subjected to a relaxation heat treatment in one twist, but it can be made to have a tensile strength of 800 to 12 without further low elongation.
Relaxation preheat treatment is performed in advance at a temperature of 0 ° 0 and a tension of 03ji/di or less, and then 160'O~220
By carrying out the relaxation heat treatment at a temperature of °C, a composite crimped yarn of even better quality can be obtained.

Here, the reason for performing the relaxation preheat treatment is that, as explained earlier in relation to the spinning speed and the physical properties of the spun yarn, if the tension heat treatment is directly performed at high temperature, both the side, pie, and side components will crystallize. This is because the crimp structure will not be formed afterward, and it is necessary to perform a pre-relaxation heat treatment in advance to develop the crimp structure. Here, the tension may be 0.03 g/dl or less. If the size is larger than this, it becomes difficult to effectively relax the crimp structure, resulting in an inferior crimp structure. In addition, the temperature needs to be higher than the glass transition temperature in order to exhibit the potential shrinkage performance between the side-pipe-side components, and 80 to 120'O is suitable.

Note that even if the temperature is higher than 120°C, it will sufficiently relax and form a crimped structure, but if the temperature is too high, both the side, pie, and side components will contract, and the resulting crimp performance will deteriorate. .

After the pre-relaxation heat treatment is carried out in this manner, a temperature-controlled relaxation heat treatment is further performed at a low tension. This is because crystallization does not progress sufficiently with the relaxation preheat treatment alone, and the crimp structure becomes flattened and a freezing phenomenon is observed in subsequent processing steps (dying, fabric tension treatment, final setting). That is, high-temperature heat treatment is desirable in order to promote crystallization and stabilize the structure. The temperature used is from 160'O to 220'Q, at which crystallization progresses; if it is lower than this temperature, the effect of stabilizing the structure in the post-process described above will be reduced, and if it is too high, shrinkage will occur, resulting in a crimp structure. There is a phenomenon where the sky becomes cloudy. The reason why the treatment is performed in a relaxed state is that if the tension is increased and the high temperature heat treatment is performed, the crimp structure will deteriorate.

On the other hand, even if the yarn after being spun is subsequently subjected to relaxation heat treatment at 160 to 220'O using a heated fluid pushing nozzle,
A good composite crimped yarn can be obtained. The relaxation heat treatment temperature with heated fluid intrusion nozzle is from 160C to 220'
Q position is suitable.

If the temperature is lower than 160C, the fabric will not be able to withstand the temperature at which it is processed after being made into a woven or knitted fabric (tension set at about 180'O), resulting in poor crimp. Furthermore, when the temperature is lower than 220'O, the spun yarn shrinks significantly on both the high [η] f and low [η] f sides, and a phenomenon is observed in which the appearance of crimp decreases. From this, 1
It is preferable to carry out relaxation heat treatment at a temperature of 60'0 or higher to promote crystallization at the same time as crimp development occurs.

In any of the methods explained above, in order to further improve the crimp performance, it is recommended to use a copolymerized polyester in which 3 to 10 mol% of a third component is copolymerized on the low [η]f side, as described above. preferable.

Many side-pie-side type transition fibers made of homopolyester and copolymer polyester have been proposed so far, but all of them use copolymer polyester on the rib [η] f side. This point differs greatly from the present invention.

To explain this point, most of the conventional technologies are 2,
It is a low-speed spinning system of 000 m/min or less, and in this speed range, the high [η] f side must be on the contraction side, so in order to improve the shrinkability, a copolymer component is added to the high [η] f side.
] It was used on the f side. However, since the present invention is a high-speed spinning system, the shrinkage must be higher on the low [η] f side, and for this reason, it is better to use a copolymer component on the low [η] f side. .

Here, as the copolymerized polyester, common ones such as inphthalic acid, dimethyl isophthalate, gegarene glycol, triethylene glycol, etc. may be used, and the thread thereof may also be 3 to 1 liters.
Oman% is sufficient. It should be noted that at 3 mO1, a very large effect cannot be expected. Also, if it exceeds 10 mO1%, spinning of a polymer on the low [η] f side becomes more difficult due to a decrease in viscosity, a decrease in melting point, etc.

The crimp performance can also be improved by adding a crystallization accelerator such as dimethyl inphthalate-5 sodium sulfonate to the distance [η] f side to reduce the number box ratio.

Further, the relaxation heat treatment after the spinning yarn take-off in the present invention may be performed directly in connection with the melt-spinning pressure, or may be performed in a separate step. That is, it may be melt-spun and then subjected to a relaxation heat treatment after being rolled up into large volumes, or further may be treated after knitting and weaving.

The present invention will be explained below with reference to a large example, and Tc, which represents crimp performance in the present invention, was determined using the following 1llll constant.

'l' c = "-2-"-X i o o%
For 1゜lo, a load of 2 Tng per denier was applied, treated in gamma well water for 20 minutes, then taken out, dried under this load at 40'Q or less for 14 hours, and then a load of 200 rAg per denier was applied. Length after minutes,! , is 1
The length is K after 3 minutes after setting 0, and the length after 1 minute after applying a load of 2 g per denier.

1, solid viscosity [η] f is free hole (free fall)
Free-hole (free-falling) filaments are the intrinsic viscosity measured in filaments of
M1 is determined by a free-hole (free-falling) filament spun with only the other polymer. In this case [l
] f is determined by the following formula.

(1) f = l:m
C (ηrel) is the ratio of the viscosity of a dilute solution of polyester in a mixture of 60% phenol and 40% carbon tetrachloride to the viscosity of the solvent mixture measured at the same temperature and in the same units; grams of polyester.

Example 1 Two types of polyethylene terephthalate having different intrinsic viscosities were melt-spun into a composite yarn using the spin method, and subjected to relaxation heat treatment at 180°C to develop crimping to obtain a composite crimped yarn of 150 denier/48 filaments. At that time, the intrinsic viscosity [η]f and spinning speed of both components of the spun yarn were varied as shown in Table 1.

The evaluation of the fabric was carried out using a 2-2 twill with a dyed finish of 1" to approximately 1sog/ze. Texture,
Sink marks, spots, and blemishes were determined by the naked eye. ◯ indicates good, △ (slightly poor), and × (slightly poor).

Example 2 Similar to Example 1, the intrinsic viscosity [η] of the same components of the spun yarn
The composite fibers obtained by changing the f-warp spinning speed were subjected to a pre-relaxation heat treatment and a high-temperature relaxation heat treatment under the conditions shown in Table 2 without subsequent drawing. Regarding the obtained composite crimped yarn,
Evaluations are shown in Table 2 in the same manner as in Example 1.

Example 3゜Same as Example 1, the intrinsic viscosity [η] of both components of the spun yarn
The composite fiber obtained by changing f and spinning speed was then
Relaxation heat treatment was performed using a heated fluid forced nozzle at the forced nozzle temperature (heated air temperature) shown in the table. The obtained composite curled yarn was evaluated in the same manner as in Example 1, and the results are shown in Table 3.

1) Isophthal #I 15 mol% copolymerized polyethylene 2) Isophthal rR 7 mol% copolymerized polyethylene Table: lente phthalate to lente 7 tallate

BRIEF DESCRIPTION OF THE DRAWINGS The figure is a graph showing the relationship between spinning speed and heat shrinkage rate of spun yarn for polyethylene terephthalate. The solid line shows the behavior of the high [η] f yarn, and the dotted line shows the behavior of the low [η] f yarn.

Claims (1)

[Claims] 1. When producing a side-pie-side type composite fiber made of polyester having an intrinsic viscosity difference Δ[η]f, the intrinsic viscosity [η]f of a polyester component with a low intrinsic viscosity
is 0.34 to 0,50°, and the intrinsic viscosity Δ[η]f of both polyester components is 0.20 to 0+30, and 4,000 to 5
A method for producing a polyester composite fiber, characterized in that the fiber is taken at a spinning speed of t Fi OO yarn/min. 2 The polyester component with the lower intrinsic viscosity [η]f is
The method according to claim 1, wherein the third component is a polyester copolymerized with 3 to 10 mol%. 3. When producing a side-pie-side type composite fiber made of polyester having an intrinsic viscosity difference Δ[η]f,
The intrinsic viscosity [η]f of the polynisder component with low intrinsic viscosity is set to 0.34 to O-S O, and the intrinsic viscosity difference Δ[η]f of both polyester components is set to 0.20 to 0.30, and the range is 4,000 to 4,000.
5 + 500 ++t Take-off at a spinning speed of 7 minutes, then at a temperature of 80-120C without stretching, o, o
A method for producing a polyester composite fiber, which comprises performing a pre-relaxation heat treatment under a tension of 3 g/d1 or less, and then a relaxation heat treatment at 160 to 220°C. 4. When producing a side-pie-side type composite fiber made of polyester having an intrinsic viscosity difference [η]f, the intrinsic viscosity of the polyester component with a low intrinsic viscosity [η]f
is 0.34 to 0.50°, and the intrinsic viscosity difference Δ[η]f between both polyester components is 0.20 to 0.30, and 4. 'OOO
1. A method for producing polyester composite fibers, which comprises taking the fibers at a spinning speed of ~5,500 m/min, and then subjecting them to relaxation heat treatment at 160 to 220°C using a heated fluid forcing nozzle. 5. The method according to claim 4, wherein the polyester component having the lower intrinsic viscosity [η]f is a polyester copolymerized with 3 to 10 mol% of the third component.