JPH03167341A - Production of combined polyester filament yarn having different shrinkage - Google Patents

Abstract

PURPOSE:To obtain the subject yarn capable of producing sufficient bulkiness by weaving, knitting or relaxing heat treatment and maintaining soft hand even under dry heat-treating conditions at a high temperature by producing yarn from two or more kinds of polyesters having different copolymerization ratios according to a specific method. CONSTITUTION:The objective yarn, obtained by initially respectively melt spinning two or more kinds of polyesters having >=10mol% difference in copolymerization ratio between a polyester having the highest copolymerization ratio and a polyester having the lowest copolymerization ratio, respectively once cooling and solidifying the respective yarns, passing the aforementioned respective yarns through a common heating zone, drawing and heat-treating the yarns, then taking off the produced yarns and having >=0.3g/d heat shrinkage stress, >=105 deg.C peak temperature of the heat shrinkage stress and <=10% difference ( S=SH2-SH1) between the dry heat shrinkage factor (SH2) after treatment with boiling water and the boiling water shrinkage factor (SH1). Furthermore, an ethylene oxide adduct of bisphenol A is preferred as the copolymerization component of the polyester.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for producing polyester differential shrinkage blend yarn.

More specifically, the present invention relates to a method for producing a polyester shrinkage blend yarn that can maintain a soft texture even after knitting, weaving, relaxing heat treatment, and high-temperature dry heat treatment.

[Prior Art] Polyester differential shrinkage blend yarn has been used for high-grade silky #1 knitting fabrics with a soft texture that has good bulk and drapability, and various applied products are popular on the market.

The differential shrinkage polyester mixed yarn is a yarn in which two or more types of polyester yarns having different heat shrinkage rates are mixed. In order to provide a difference in shrinkage, it is known to provide a difference in copolymerization rate as well as a difference in heat treatment between yarns and a difference in the degree of polymerization of polyester.

An example of polyester shrinkage mixed fiber yarns having different copolymerization rates is disclosed in JP-A-55-45873. After knitting, knitting and weaving, such blended yarns are heat-treated under relaxed conditions during scouring and other steps, so that latent differences in heat shrinkage between each yarn are revealed, and the result is sufficient even under the constraining force of the woven or knitted structure. It exhibits high bulkiness and can be used to create silky woven and knitted fabrics with a soft texture. However, this woven and knitted fabric undergoes various processes such as alkali treatment, dyeing, intermediate setting, and printing, and is subjected to high-temperature heat treatment during the process of becoming an R finished product, causing the threads that make up the #1 knitted fabric to become rough. It contracts. For this reason, the good texture after the initial relaxing heat treatment cannot be maintained, resulting in a woven or knitted fabric with a hard and rough texture.

On the other hand, Japanese Unexamined Patent Publication No. 1983-20320 attempts to obtain polyester shrinkage mixed fiber yarn by high-speed spinning method. This publication discusses the relationship between the copolymerization ratio of a high shrinkage polymer and the spinning speed. However, consideration is not given to heating stretching and heat treatment, and only products with low heat shrinkage stress can be obtained. Therefore, although you can get something with a soft texture! The Ia knitted fabric has the disadvantage that it lacks bulk under restraint and lacks a sense of fullness.

[Problems to be Solved by the Invention] Recently, high-speed spinning at a spinning speed of 4000 m/min or more has become widespread as a production process for melt spinning polyester and the like. This is not only because the process itself has a large cost reduction effect, but also because the fibers obtained by this process have a soft texture, dyeability, etc. compared to IJAH obtained by the conventional two-step method of spinning and drawing. This is because it exhibits excellent properties.

A woven or knitted fabric made of high speed spun fibers exhibits a good texture with a softness of 1 or higher. This is because the orientation of the amorphous molecular chains within the fiber becomes low and the substrate becomes softer due to the special structure formation process. Therefore, in software, S
Although this process is thought to be suitable for obtaining a differentially shrinkage mixed fiber yarn with a loose feel, it has been found that this is not necessarily the case.

It is because the fibers obtained by high-speed spinning have shrinkage behavior.
This is because the fibers are different from those obtained by the conventional two-step method. The inventors of the present invention took note of this point and conducted extensive studies, resulting in the present invention.

The object of the present invention is to provide a polyester shrinkage blend yarn that does not have the above-mentioned drawbacks, that is, a polyester shrinkage blend blend that can exhibit sufficient bulk through knitting and weaving and relaxing heat treatment, and can maintain a soft feel even under high-temperature dry heat treatment. The present invention provides a method for manufacturing yarn.

[1,000 Steps to Solve the Problems] In other words, the purpose of the present invention described above is to solve the difference in copolymerization rate between a polyester with the highest copolymerization rate and a polyester with the lowest copolymerization rate in a method for manufacturing a polyester differential shrinkage mixed fiber yarn. Melt-spun two or more types of polyesters each having a content of 10 mol% or more, cooling and solidifying each yarn, and then passing each yarn through a common heating zone to heat treatment for stretching, and then taking it off. The heat shrinkage stress of the mixed fiber yarn is reduced to 0.
．． From 39/d, the peak temperature of heat shrinkage stress is 105℃
The above can be achieved by a method for producing a polyester differential shrinkage blend yarn characterized in that the difference ΔS=SH2−SH1 between the dry heat shrinkage rate SH2 and the boiling water shrinkage rate S111 after boiling water treatment is 10% or less.

The polyester differential shrinkage mixed fiber yarn produced by the present invention has two major characteristics.

That is, first, the differential shrinkage mixed fiber yarn obtained by the method of the present invention exhibits sufficient bulk even under the restraining force of the woven or knitted fabric structure. This property can be characterized by the bulkiness of the mixed yarn ~1 determined by the measurement method described below, and M
This corresponds to 25 cc/() or more, preferably 30 cc/g or more.

The reason for this feature is that polyesters with copolymerization ratios different by 10 mol% or more are melt-spun, each yarn is once cooled and solidified, and then each yarn is passed through a common 7JO thermal zone for drawing heat treatment. This is because By passing through this zone and carrying out stretching heat treatment, 0.3
A 4-4 structure is formed that brings out a high heat shrinkage stress of Q/d or higher. This property is similar to that of conventional yarns that are drawn after slow spinning and winding. Japanese Unexamined Patent Publication No. 64-2032
As in Publication No. 0, the yarn obtained by a high-speed spinning process without consideration for the drawing heat treatment in the heating zone has a high degree of crystallinity and a low degree of amorphous orientation, so the heat shrinkage stress is 0.25 Md.
Therefore, it does not have the ability to develop sufficient bulk under restraining force. In contrast, in the present invention, since the heat shrinkage stress is high, sufficient bulkiness can be exhibited even under the restraining force of the woven or knitted structure. Moreover, it is possible to maintain the soft texture characteristic of high-speed spinning.

A second feature of the polyester shrinkage differential blend yarn of the present invention is that it can maintain its soft feel even when subjected to high temperature heat treatment after bulking. The reason for this is that the initial bulking treatment after knitting and weaving releases all heat shrinkage stress, resulting in an extremely stable fiber structure, which hardly causes further shrinkage in subsequent heat treatments. This property is determined by the measurement method described below, which is the difference ΔS between the dry heat shrinkage rate SH2 and the boiling water shrinkage rate SH+ of the mixed yarn after boiling water treatment.
2-Characterized by SHI, ΔS is 10% or less,
This corresponds to preferably 5% or less. This property is similar to that of yarn obtained by high-speed spinning without a heating zone, but it is different from the conventional differential shrinkage mixed fiber yarn that is drawn after being spun and wound at low speed, such as the aforementioned Japanese Patent Application Laid-Open No. 55-45873. Totally different. Differential shrinkage mixed fiber yarn obtained through the conventional spinning process is
The yarn further shrinks due to the high-temperature heat treatment after the bulking treatment in knitting #1, resulting in a final product with a rough and hard texture, and the appearance of the fabric is full of sink-like defects. The reason for exhibiting such special heat shrinkage behavior is considered to be that two or more yarns of the present invention pass through a common heating zone. Stretching in the heating zone is extremely complex, as it is influenced by the orientation of the fibers entering the heating zone, the spinning tension, the ease of stretching based on the volima matrix, and the field temperature excess of the yarn in the heating zone. This is a phenomenon.

However, on the contrary, the advantage of passing two or more types of yarn through a common heating zone is that the drawing of each yarn, including the stretching ratio, can be naturally controlled to be optimal. . In the present invention, by passing two types of yarns through a common heating zone, yarns made of components with different copolymerization rates can be stretched optimally. This is considered to be indicative of the behavior.

As described above, it is only the mixed fiber yarn obtained by the present invention that can develop bulk under the restraining force of the woven or knitted fabric structure and maintain its soft texture through high-temperature treatment after bulk development. This is due to the special mM structure of the fiber obtained by the combination of the polyester specified in and the spinning method.

In the present invention, the difference in copolymerization rate between the polyester with the highest copolymerization rate and the polyester with the lowest copolymerization rate must be 10 mol% or more. Here, copolymerization rate P (mol%)
is the sum of a certain molar fraction Pa (mol%) of the copolymerized acid to the acidic component of the copolymerized polyester and a mole fraction Pb (mol%) of the copolymerized glycol component to the total glycol component of the copolymerized polyester. , that is, P=Pa
+Pb is one shift.

In these polyesters, the copolymerization rate is 10 mol%
If there is no difference above, the difference in heat shrinkage rate is small and sufficient m-heightness cannot be achieved. Polyester with a high copolymerization rate is a prerequisite for yarns on the high shrinkage side, and in order to ensure a soft feel, the copolymerization rate is preferably 30 mol% or less, and particularly preferably 25 mol% or less. The polyester having a low copolymerization rate is a component of the low-shrinkage yarn of the mixed fiber yarn of the present invention, and may be a polyester containing substantially no copolymerization component.

As copolymerization components in the present invention, aromatic dicarboxylic acids, aliphatic dicarboxylic acids, aliphatic diols, alicyclic diols, aromatic diols, or diols obtained by adding ethylene oxide or the like to these may be used. Degi, specifically isophthalic acid, naphthalene-2.6
-Dicarboxylic acid, adipic acid, sebacic acid, 1,4-butanediol, diethylene glycol, trimethylene glycol, polyethylene glycol with molecular ffi of about 600 to 6000, cyclohexanediol, ethylene oxide adduct of bisphenol A, ethylene oxide adduct of bisphenol sulfone, etc. can be preferably used. Since the shrinkage behavior differs depending on the copolymerization components, it is necessary to set the copolymerization ratio so that the above-mentioned ΔS falls within the range of the present invention.

In addition, it is preferable to use an aromatic diol as the diol which has particularly good thermal stability and tends to have a high boiling water shrinkage rate SH1. For example, an ethylene oxide adduct of isophthalic acid and bisphenol A is mixed with It is more preferable to copolymerize in fractions.

10.0≦Fa+Fb≦25.0 1.0≦Fb≦4.8 (Fa is the molar fraction (%) of isophthalic acid to the flavoring components of the copolyester, Fb is the molar fraction (%) of isophthalic acid to the total glycol component of the copolyester The molar fraction (%) of the ethylene oxide adduct of A is
It is preferable to make it less than mol%. In addition, in order to sufficiently express the bulk, which is the advantage of copolymerizing isophthalic acid and the ethylene oxide adduct of bisphenol 8, and to have a preferable bulk level of 30 cc/g or more, it is necessary to set b to 1.
．． The content is preferably 0 mol% or more. On the other hand, in order to reduce shrinkage during high-temperature heat treatment and maintain a soft texture in the final product, it is preferable that b be 4.8 mol% or less.

As the polyester of the present invention, polyethylene terephthalate whose basic unit is ethylene terephthalate can be preferably used.

The intrinsic viscosity of polyester is orthochlorophenol2
In a 5°C solution, the range is preferably from 0.45 to 0.75,
The range of 0.55 to 0.65 is more preferable. In addition, if sagging occurs in the wound package, it will be difficult to pull out the yarn or pass through the process in the subsequent process, so to prevent this, it is preferable to change the intrinsic viscosity between polyesters with different copolymerization rates. Ru. Furthermore, it is also preferable to increase the shrinkage rate difference by combining the copolymerization rate and the intrinsic viscosity, such as increasing the intrinsic viscosity of a polyester with a high copolymerization rate.

In the present invention, the two or more components of polyester are discharged from separate discharge holes, cooled and solidified, passed through a common heating zone, subjected to stretching heat treatment, and wound up. The shape of the spinneret hole may be round, Y, T, or other known shapes. Two or more components of polyester may be discharged from one spinneret, or two or more polyesters may be discharged from two or more spinnerets.

The dispersion state of high- and low-shrinkage yarns of mixed fiber yarns, so-called "Konare", is best achieved by discharging two or more portions of polyester from one spinneret, and the discharge hole group of each yarn is circular or alternate. It is even better to arrange it in , and it is preferably used in the present invention.

The polyester discharged from the spinneret is cooled and solidified by cooling air. Cooling is performed until the temperature at which the polyester yarn solidifies, that is, below the glass transition temperature, so that the subsequent drawing heat treatment can be performed stably.

Once cooled and solidified, the polyester yarn is introduced into a heating zone and subjected to drawing heat treatment. In order to allow the yarn to stretch freely in the heating zone, it is preferable that the yarn does not come into contact with anything other than the yarn path regulating section at the entrance or exit. It is preferable to use a heating tube as the heating zone. Such a heating cylinder is one that is heated from the surroundings, one that is heated by heated dry heated air,
Alternatively, it is preferable to use one filled with saturated steam, or a combination of these.

In the heating zone, it is necessary that the passing yarn be subjected to drawing heat treatment. As a result of the drawing heat treatment, a mixed fiber yarn having a heat shrinkage stress of 0.3 g/d or more and a peak temperature of heat shrinkage stress of 105° C. or more is obtained. What is stretching heat treatment?
It refers to stretching and subsequent heat treatment. For drawing to occur, it is necessary that sufficient tension be applied to the yarn for drawing and that sufficient heat be supplied from the heating zone.

Here, the tension is (actual tension of the yarn at the entrance of the heating zone) ÷ <denier of the wound yarn>, and the tension is calculated by dividing the actual tension of the yarn at the entrance of the heating zone by the denier of the wound yarn, the take-up speed, and the tension from the spinneret to the heating zone. It changes depending on distance etc. The tension required for stretching is usually 0.3
Md or more. When the stretching tension is less than 0.3 Md, the heat shrinkage stress of the yarn does not reach 0.3 Md, and therefore no bulk is developed under the restraining force of the woven or knitted fabric structure.

In addition, the heating zone temperature necessary for drawing and heat-treating the yarn passing through the heating zone is preferably 105°C or higher, and 105°C or higher.
More preferably, the temperature is 10°C or higher. When the heating zone temperature is lower than 105° C., even if stretching occurs, sufficient heat treatment is not performed, so the boiling water shrinkage rate becomes extremely high, exceeding 60%, and only a rough #1 knitted fabric is obtained.

The temperature of the heating zone is a major factor that affects the thermal shrinkage rate of mixed fiber yarns, and in order to obtain bulk with sufficient swelling, heat treatment is performed at a temperature equivalent to the peak temperature of thermal shrinkage stress of 140°C or less. It is preferable that the heat treatment corresponds to a peak temperature of 130° C. or less as the peak temperature of heat shrinkage stress. The approximate temperatures of the heating zone corresponding to the peak temperatures of 140°C or lower and 130°C or lower of the heat shrinkage stress are as follows:
They are 150°C or lower and 140°C or lower, respectively.

The distance from the spinneret to the entrance of the heating zone is preferably 0.5 to 4.0 m in order to provide sufficient cooling under the spinneret, workability, and sufficient tension caused by air resistance. 1.0 to 3.0 m is more preferable. The length of the heating zone is preferably 0.5 to 3.0, preferably 1.0 to 2.0, from the viewpoint of stable stretching heat treatment and energy saving.
0 m is more preferable. The take-up speed is 4000 to 7000 m in terms of the mechanical properties of the yarn obtained and the spun yarn breakage.
/min is preferable, and 5000 to 6000 m/min is more preferable.

In the present invention, as described above, two or more types of polyester yarns are passed through a common heating process, but in order to improve the splitting state of each yarn of the mixed fiber yarn, so-called "coating". It is also suitable for each thread to pass through a common heating zone.

Even if you try to improve the dispersibility by passing each yarn through a separate heating zone, mixing the fibers before winding, and performing air entanglement treatment,
The texture is not good, and on the contrary, fluff increases during air entanglement treatment.

In the polyester of the present invention, titanium oxide is added in order to reduce the friction resistance with the thread guide during the spinning process, weaving, weaving, and culm, or to impart a special hue such as mild luster or dullness. , 0.015 to 5.0% by weight of fine particles such as calcium carbonate, kaolin, metakaolin, and silica.
It is preferable to add. In addition, in order to impart other functionality, antistatic agents, flame retardants, light stabilizers, moisture absorbers, coloring agents, etc. may be added as necessary in the range of 0.01 to 5.0% by weight. can.

The single yarn denier after winding of a yarn made of polyester with a high copolymerization rate is 1.2 to 5.0 times larger than the single yarn denier after winding of a yarn made of a polyester with a low copolymerization rate. Since the stiffness and tension of the obtained 11 knitted fabric are improved by this method, it is preferably employed in the present invention. In this case, by setting the single yarn denier of the yarn with a small single yarn denier to 1.0 denier or less, a softer texture can be achieved.
Since it can be applied to one knitted fabric, it is suitable for the present invention.

In the mixed fiber yarn of the present invention, each yarn or one yarn can be made into a composite fiber within a range that does not impair its properties. Such a composite fiber may contain an easily eluted component, a conductive component, or a conductive component in addition to the polyester having a different copolymerization rate used in the present invention.

[Example] The present invention will be briefly and concretely explained using the following example.

First, methods for measuring heat shrinkage stress, boiling water shrinkage rate, dry heat shrinkage rate after boiling water treatment, and bulkiness in the present invention will be described below.

A. Heat shrinkage stress and peak temperature of heat shrinkage stress were measured using a heat stress measuring instrument KE-2 manufactured by Kanebo Engineering.
A sample of 0 Cffl (mixed fiber yarn) is made into a loop of 10 cm, and the denier of the sample Fl (mixed fiber yarn) to be measured is X 1 /1
After adjusting by applying an initial load of 5, the temperature was increased at a temperature increase rate of 150° C./min to obtain a heat shrinkage stress curve. The stress (+; +/d 2 ) and temperature (° C.) at the peak position are read from this curve. The recorder used was an X-Y recorder, type 3083 manufactured by Yokogawa Electric.

B. The boiling water shrinkage test yield is 1' for a 10-turn skein with a circumference of 1 m.
) sample and calculate the original length 1 under a 0.1 Md load. Next, after processing for 15 minutes in boiling water under no load, 0. I
The length L2 after treatment is determined under Md, and the boiling water shrinkage rate S day 1 (%) is calculated from the following formula (the average value of 5 measurements is taken).

SH+ = ((Ll-12)/L+)XIOOC. Dry heat shrinkage rate after boiling water treatment }ll! After air-drying the sample after water treatment, 2IIl
After processing for 5 minutes in a dry heat 180°C open environment under a load of g/d, the length L3 after treatment was determined under a load of 0.1 a,,'d, and the length L3 after treatment with boiling water was calculated using the following formula. Dry heat shrinkage rate S
Calculate H2 (%) (take the average value of 5 measurements).

SH2=((Ll-L3)/Ll)XIOO%D. Bulk Height Figure 1 is a perspective view of a device for measuring bulk height M, and Figures 2 (8), (B) and (C) are sketches for explaining the measuring method using this device.

Two notches 2 are provided on the upper surface of the sample stage 1, and the outer edge interval 3 is 5 mm. A flexible film 4 with a width of 25 mm is passed through the notches 2, and a metal fitting 5 with a pointer and a load 6 are attached to the lower end of the flexible film 4. combine. The pointer on the metal fitting 5 is set so as to indicate the O position on the scale 7 when no sample is attached.

For the sample, prepare a skein of 80 III yarn with a circumference of 11+1 and a skein of 48,000 denier (for example, if the yarn has a nominal fineness of 30 denier,
0x BOX 2 = 4800, 48000÷48
00 = 10 te 10 kase, display [! r! For 175 denier yarn, 75X 80X 2 = 12000
, 48000 ÷ 12000 = 4 = 4 cassettes). This skein is subjected to heat treatment similar to the measurement of the dry heat shrinkage rate after boiling water treatment in Section C above, and the skeins are aligned. Next, the aligned skeins are folded into four as shown in FIG. 2(A) to form sample 8, and the front view of FIG. 2(8) and the front view of FIG. 2(C)
As shown in the cross-sectional view of
and sample stage 1. The load 6 is added to the metal fitting 5 with a pointer so that it becomes 509, and the value L (Clll) indicated by the pointer is read.

The bulk height M is calculated from the following formula.

M (cc/g>=V/W V= (L2/l x2.5 W=DX (100 / (100-SH2))XPx
(0.025/9000) (where ■ is the volume in the tape (CC), W is the yarn weight in the tape 1 (o), D is the fineness (denier) of the sample yarn before heat treatment, and P is the volume in the tape The number of threads parallel to SH
2 is the dry heat shrinkage rate measured in Section C above. ) Example 1 After carrying out an esterification reaction using terephthal M/ethylene glycol and isophthalic acid/ethylene glycol slurries, an ethylene glycol solution of bisphenol A/2-ethylene oxide adduct was added, and the reaction was carried out as usual. Polymerization was carried out according to the method, and the mole fraction Fa of inphthalic acid with respect to the total acid components of the copolymerized polyester was 11.0%, and the mole fraction Fb of the adduct of bisphenol and 2 ethylene oxide with respect to the glycol component of the copolymerized polyester was 4.0%. 0
%, the intrinsic viscosity in Orunc mouth phenol at 25°C is 0.
67 copolymerized polyester chips were obtained.

In addition, chips of uncopolymerized polyethylene terephthalate having a solid 4j viscosity of 0.65 and having a width of 25°C orthochloro12]noenol were obtained.

The difference in copolymerization rate is 15.0 mol%.

In addition, calcium carbonate particles were added to the copolymerized polyester, and particles caused by the catalyst were generated in the non-copolymerized polyethylene terephthalate to improve the passability of the yarn in spinning and higher steps.

Non-copolymerized polyethylene terephthalate was extracted from the 12 Y holes located at P C 0 70 of the spinneret.
p Q [) Copolymerized polyester was spun at a spinning temperature of 290°C at the same discharge rate from 12 Y holes located at 40 mm. After passing through a heat insulator 20 cm below the spinneret, it was cooled in a 50 cm long uniflow chimney at a wind speed of 20 m/min and an air temperature of 30°C. Inner diameter 30mm, inner wall temperature 130℃
Stretching heat treatment is carried out using a heating cylinder, and an oil agent and entanglement are sequentially applied. After passing through the first and second take-up rolls at a circumferential speed of 5200 m/min, a 50 denier 24 filament mixed yarn is wound up at a tension of 0.25 Md. Ta. The tension at the inlet of the heating zone at this point was 0.46 Md.

The obtained yarn was designated as Taka 1, and its yarn properties are shown in Table 1.

This yarn is woven vertically and horizontally into habutae, scoured in boiling water for 5 minutes, dried at 200℃ for 5 minutes in a relaxed state, dyed at 130℃, and printed.After passing through the culm, 180℃ , heat fixation was performed for 30 minutes. Table 1 shows the texture and appearance of the obtained fabric.

As is clear from Table 1, N. 1 has a heat shrinkage stress of 0.3 Md or more, a heat shrinkage stress peak temperature of 105°C or more, ΔS of 10% or less, and a bulk height of 25 as required by the present invention.
Satisfies all of the characteristics of CC/Q or higher. therefore,
Shows good texture and appearance.

Comparative Example 1 The process was carried out in the same manner as in Example 1 until cooling, but without drawing heat treatment in the heating zone, after oiling at 2.2 m below the spinneret, convergence and entanglement were applied, and the spinning rate was 5600 m/min each day. Take it off with 0 tension. Core 2 is a yarn of 50 denier 24 filament 1 wound at 25 g/d.

The yarn was spun, cooled, and wound at 1800 m/min in the same manner as in Example 1, and the wound yarn was drawn at 87°C to 2.7
50 denier 2 heat-treated and rolled up with a heated roll at 5°C
4 filament thread N. Set it to 3.

N. Table 1 shows the properties of the mixed fiber yarns Nos. 2 and 3.

A woven fabric similar to that of Example 1 was obtained using the obtained mixed fiber yarn. Table 1 shows the texture and appearance of the obtained fabric.

As is clear from Table 1, since Seed 2 was not subjected to the stretching heat treatment in the heating zone, the heat shrinkage stress was low, and the bulk in the fabric was not sufficiently developed, resulting in a fabric with a flat texture.

N. 3 is also different from the present invention in the manufacturing method of the mixed fiber yarn, so Δ
S, that is, 31-12-31-1+ exceeds 10, the texture of the fabric becomes rough and hard, and the outer inkstone also has sink-like defects on the weft yarn, and the poor quality is 0. .

(Leaving space below) Example 2 Polyester differential shrinkage mixed fiber yarn was produced in the same manner as in Example 1 except that the mole fraction of isophthalic acid in the copolymerized polyester "a" and the mole fraction Fb of the bisphenol-2 ethylene oxide adduct were changed. "a", "b", their yarn properties, and the texture and appearance of the fabric obtained in the same manner as in Example 1 are shown in Table 2.
Shown below.

As is clear from Table 2, N. Sample No. 7 is a comparative example, in which the difference in copolymerization rate was less than 10 mol %, and the bulk of the fabric was small and did not have a fluffy feel.

Comparative Examples 4 and 6 are conventional yarns, because the Fb content is not within the range of 1.0 to 4.8 mol%, so the texture of the fabrics is slightly lacking in fullness and is somewhat rough and hard. 1 is better than 2 and 3, and is within the scope of the present invention. Core 8 has a difference in copolymerization rate of more than 25 mol%, so
Although the shrinkage rate is high, the texture is a little rough and hard, and some staining spots are observed, the degree of these is small and the purpose of the present invention is achieved.

Example 3 Mixed fiber yarns 9 to 11 of 50 denier 24 filaments were prepared in the same manner as in Example 1 except that the inner wall temperature T of the heating cylinder was changed.
I got it. The yarn properties are shown in Table 3.

One woven fabric similar to that of Example 1 was made using the obtained mixed fiber yarn. Table 3 shows the texture and appearance of the obtained fabric.

As is clear from Table 3, the heating cylinder temperature in the comparative example was 1.
00℃N. No. 9 was a yarn that was not heat treated inside the heating cylinder, had an extremely high shrinkage rate, and was completely unusable.

N. obtained by Masaaki Moto. Those with a level of 10 or 11 exhibit almost good texture and appearance. However, the material No. 11 in which the heat shrinkage stress peak temperature exceeds 150° C. has a rather low shrinkage rate, and the texture of the fabric is somewhat lacking in fullness.

(The following is a blank space) [Effect of the invention] The polyester differential shrinkage mixed fiber yarn obtained by the present invention has f11
It exhibits sufficient bulk under the constraining force within the knitted fabric, and maintains its soft feel through high temperature treatment after bulking. Therefore, the final product can be made into a silky woven or knitted fabric that has an extremely soft and fluffy feel compared to conventional products.

In addition, in the polyester differential shrinkage mixed fiber yarn of 1q in the present invention, components with different shrinkage rates are well dispersed among each other,
The final product also has a very good appearance because the high shrinkage component yarns do not twitch. Further, by the manufacturing method of the present invention, it is possible to obtain a polyester shrinkage mixed fiber yarn at a lower cost than conventional manufacturing methods and with good spinnability.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a device for measuring bulk height M, and FIGS. 2(^), (B) and (C) are sketches for explaining the measuring method using this device.

Claims (1)

[Claims] In the method for producing polyester differential shrinkage blend yarn, two or more types of polyesters having a difference in copolymerization rate of 10 mol% or more between the polyester with the highest copolymerization rate and the polyester with the lowest copolymerization rate are melt-spun, and each Each yarn is once cooled and solidified, and then each yarn is passed through a common heating zone to be subjected to a drawing heat treatment, and then taken off, so that the heat shrinkage stress of the mixed fiber yarn is reduced to 0.3 g/d or more. The peak temperature of shrinkage stress is 105°C or higher, and the difference ΔS between the dry heat shrinkage rate SH_2 after boiling water treatment and the boiling water shrinkage rate SH_1 = SH_2
- A method for producing a polyester differential shrinkage blend yarn, characterized in that SH_1 is 10% or less.