JPH11152635A - Special polyester spun yarn and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a special polyester spun yarn capable of giving knitted fabrics with excellent puffy feeling, extremely soft surface tough, favorable firm texture and high resilience, and to provide a method for producing the spun yarn. SOLUTION: This spun yarn is obtained by blending spinning of low-shrinkage polyester short fibers each with an intrinsic viscosity [ηs] of >=0.6 W extension in the constant stress elongation zone in its strength elongation curve of <=20%, an elongation at break of 90-150%, and a boiling water shrinkage and a 180 deg.C dry heat shrinkage of each 1-5%, and high-shrinkage polyester short fibers consisting of a highly shrinkable polyester copolymerized with a 3rd component and having a boiling water shrinkage of <=15% and a 180 deg.C dry heat shrinkage after treated with boiling water at 5-30%, in the weight ratio of (30:70) to (80:20).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spun special polyester yarn and a method for producing the same, and more particularly, to a low-shrink polyester short fiber having a high intrinsic viscosity and a specific physical property range, and a third component. A special polyester spun yarn blended with a high-shrink polyester short fiber with an improved copolymerized shrink profile, combining excellent swelling feeling and extremely soft surface touch, as well as good tension and waist and high rebound. The present invention relates to a special polyester spun yarn capable of obtaining a woven or knitted fabric having the same and a method for producing the same.

[0002]

2. Description of the Related Art Hitherto, it has been widely practiced to produce a spun yarn exhibiting bulkiness by blending two or more types of short fibers having different shrinkages. A spun yarn is formed by blending a staple fiber and a short fiber, and the spun yarn is formed into a woven or knitted fabric and then heat-treated to increase the bulk due to a difference in shrinkage between the two short fibers. However, in such a conventional spun yarn,
There is a problem that the bulkiness is reduced, the resilience of the obtained woven fabric is reduced, and wrinkles are likely to be formed every time the higher process is performed.

[0003] In order to improve such disadvantages of the different shrinkage fibers, Japanese Patent Publication No. 3-34234 discloses a different shrinkage polyester multifilament in which the low shrinkage fiber has an elongation of 80% or more and an elongation modulus of 600 kg /. mm ² or less, crystallinity 25% or more, thermal stress 40 mg / d or less, boiling water shrinkage 3% or less, elongation of high shrinkage fiber 40% or less, elongation rigidity 800 kg / mm ² or more A composite yarn having a thermal stress of 100 mg / d or more and a boiling water shrinkage of 5% or more is disclosed. According to this publication, a woven or knitted fabric which is less likely to wrinkle and has good resilience can be obtained. However, when the low shrinkage fiber of this publication is used as a multifilament, there is no problem in the high process passability, but short fibers are used. When the short fiber is passed through an essential carding process after drawing, a draw occurs partially due to the process tension, resulting in a spun yarn having large unevenness, and has a drawback that the spinnability deteriorates. Further, when the composite yarn according to the publication is made into a woven or knitted fabric by shortening the fiber, the swelling feeling is insufficient.

It is also known that other drawbacks of a woven or knitted fabric using a spun yarn of different shrinkage blending include that the hand tends to be hard and the dimensions of the woven or knitted fabric are easily changed. For the purpose of improving this drawback, Japanese Patent Publication No. 60-54404, Japanese Patent Publication No. 62-7300, and Japanese Patent Publication No. 63-66
Japanese Patent Application Laid-Open No. 923-923 discloses the use of spontaneously extensible short fibers. In particular, Japanese Patent Application Laid-Open No. 6-346321 discloses a polymer having a high intrinsic viscosity of 3000 m / m.
This patent discloses that high-speed spinning is performed for at least one minute, stretched at a low temperature, and then subjected to relaxation heat treatment to form a spontaneously extensible multifilament. However, any of such spontaneously extensible short fibers or multifilaments is obtained by stretching a so-called POY obtained by high-speed spinning and then performing a relaxation heat treatment, or by performing a relaxation heat treatment and then stretching. Since the film undergoes a stretching step, the Young's modulus tends to be high, and the softness is still insufficient. Further, a woven or knitted fabric using the spontaneously elongated yarn alone has a drawback that the woven or knitted fabric lacks swelling feeling and lacks tension and waist.

Further, as means for obtaining flexible polyester multifilaments or short fibers, Japanese Patent Application Laid-Open No.
Japanese Patent No. 52721 discloses that a polyester chip having a high intrinsic viscosity is melt-spun at an ultra-high speed of 4000 m / min or more. According to the publication, although a practical polyester multifilament or short fiber can be obtained without performing a drawing heat treatment,
Since it is obtained by so-called ultra-high-speed spinning, it has a high Young's modulus, requires ultra-high-speed spinning equipment, and has a drawback that a woven or knitted fabric obtained by using the fiber alone lacks swelling feeling.

Japanese Patent Application Laid-Open Nos. 55-62240 and 55-137243 for the purpose of improving the swelling feeling, lack of tension and waist of the woven or knitted fabric obtained by using the short fibers or multifilaments alone. JP-A-56-1
No. 12537, JP-A-56-123419,
JP-A-5-331730 discloses that a spontaneously extensible short fiber is used as a low-shrink short fiber, and the low-shrink short fiber is blended with or mixed with a high shrink fiber. According to these publications, it is possible to obtain a woven or knitted fabric having a good resilience and a soft feel. However, any of the spontaneously extensible short fibers is obtained by stretching a so-called POY obtained by high-speed spinning and then performing a relaxation heat treatment, or by performing a relaxation heat treatment and then stretching. In addition to the fact that the Young's modulus is likely to increase, the spontaneously elongating short fiber has a spontaneous elongation of 3% or more.
There is a disadvantage that it is easily separated into two layers and a fluffy feeling is easily generated.

In order to improve such disadvantages, the present applicant has disclosed Japanese Patent Application Laid-Open Nos. Sho 62-199827 and Sho 62-1.
No. 99828, POY obtained by high-speed spinning
We have proposed a spun yarn that can obtain an extremely flexible woven or knitted fabric by subjecting it to stretch heat treatment under specific conditions. The use of the spun yarn according to the publication gives excellent woven and knitted fabrics having bending properties similar to wool, but requires high-speed spinning equipment, and is still insufficient in terms of swelling, tension and waist. There is.

On the other hand, JP-A-4-194007 and JP-A-4-194010 disclose a method for obtaining a mixed fiber consisting of a polymer using a spinneret having a plurality of ejection hole groups having different cross-sectional areas. By making a discharge hole continuously expanding the cross-sectional area of at least one group of discharge holes of the group of discharge holes, the maximum cross-sectional area is at least 0.785 mm ² by spinning one group as a spinneret at a high draft, A production method for obtaining a mixed fiber by single spinning is disclosed. According to the publication, the orientation and elongation level of a thick denier component can be made higher than the orientation and elongation level of a thin denier component. An undrawn yarn is obtained. However, the undrawn yarn with different fineness needs to be drawn and heat-treated, and the obtained drawn yarn has drawbacks of high orientation, low elongation, high Young's modulus and lack of softness.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to overcome the above-mentioned problems of the prior art, and to have an excellent swelling feeling and an extremely soft surface touch, as well as good tension and waist and high resilience. An object of the present invention is to provide a special polyester spun yarn from which a woven or knitted fabric can be obtained and a method for producing the same.

[0010]

SUMMARY OF THE INVENTION The object of the present invention is to achieve an intrinsic viscosity [ηs] of 0.66 or more, an elongation at constant stress in an elongation curve of 20% or less, and an elongation at break of 90 to 90%.
150%, both boiling water shrinkage and 180 ° C dry heat shrinkage are 1
It consists of a low-shrink polyester short fiber of about 5% and a high-shrink polyester obtained by copolymerizing the third component, and has a boiling water shrinkage of 15% or less and a dry heat shrinkage of 180 ° C after boiling water treatment of 5%.
30% high-shrink polyester short fiber by 30/7
A special polyester spun yarn characterized by being blended at a ratio of 0 to 80/20, and a chip made of polyester having an intrinsic viscosity [ηc] of 0.68 or more, a spinning draft 5000 having a mouth surface depth of 70 mm or less. As described above, the low-shrinkage polyester short fiber which is melt-spun at a spinning speed of 2000 m / min or less, heat-treated the obtained undrawn yarn at a dry heat of 140 to 200 ° C. under a tension of 1 to 5%, and then shortened to a short fiber. A chip made of a high-shrinkable polyester copolymerized with a third component is melt-spun, and the undrawn yarn is drawn, and subsequently heat-treated at 125 to 180 ° C. for 3 seconds or more at a relaxation rate of −2 to 2%. This can be achieved by a method for producing a special polyester spun yarn, which is characterized by blending a short-shortened high-shrink polyester short fiber at a ratio of 30/70 to 80/20.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the spun polyester yarn of the present invention will be described in detail.

The special polyester spun yarn of the present invention is a special polyester spun yarn obtained by blending a low shrinkage polyester short fiber having a specific range of physical properties and a high shrinkage polyester short fiber having an improved shrinkage profile obtained by copolymerizing a third component. It is important that The spun yarn, in which the low-shrink polyester short fiber and the high-shrink polyester short fiber are each independent, combines the excellent swelling feeling and the extremely soft surface touch, which are the objectives of the present invention, and the good tension and waist and high resilience. You cannot get a woven or knitted fabric. The special polyester spun yarn of the present invention has an improved shrinkage profile obtained by copolymerizing a third component with a low-shrinkage polyester short fiber having not only a swelling feeling and a soft touch and tension and waist, but also a specific range of physical properties. For the first time by blending with high-shrink polyester short fibers
It is surprising that it can exhibit high resilience.

The low-shrinkage polyester short fibers of the present invention have an intrinsic viscosity [ηs] of 0.66 or more. When the intrinsic viscosity [ηs] is less than 0.66, the elongation of the constant stress elongation region in the elongation / elongation curve is 20 in the production method described later.
% Or less, and it is difficult to obtain a low-shrink polyester short fiber having a breaking elongation of 90 to 150%. On the other hand, when the intrinsic viscosity [ηs] is less than 0.66, it is difficult to obtain a highly resilient woven fabric which is the object of the present invention. The intrinsic viscosity [ηs] is 0.1 in comparison with the ordinary intrinsic viscosity [ηs] of about 0.62.
Although the reason for exhibiting higher resilience at 66 or more is not clear, it is considered that since the molecular chain is long, the number of amorphous materials surrounded by crystals increases, and it is easy to return to bending. The intrinsic viscosity [ηs] in the present invention means the intrinsic viscosity of the low-shrink polyester short fiber, and is different from the intrinsic viscosity [ηc] of the chip. Generally, in melt spinning of polyester, the intrinsic viscosity [η] decreases due to thermal decomposition or hydrolysis. Therefore, the intrinsic viscosity [ηs] 0.
In order to obtain 66 or more, a chip having an intrinsic viscosity [η] higher than the intrinsic viscosity [ηs] of the low-shrink polyester short fiber is used.

The low shrinkage polyester short fiber of the present invention has a constant stress elongation region elongation of not more than 20% in a high elongation curve. The constant stress elongation region elongation in the present invention,
The elongation of a region (a) that elongates at a constant stress as indicated by 1 in FIG. 1 is shown. The elongation of the constant stress elongation region of 20% or less means the elongation of the so-called constant stress elongation region of POY obtained by conventional high-speed spinning. Elongation sufficiently lower than that. When the elongation in the constant stress elongation region of the elongation curve in the elongation measurement described later exceeds 20%, the fibers are elongated by the tension applied in the spinning step, and undesirably thick and thin spots are generated.

The low shrinkage polyester short fiber of the present invention has a breaking elongation of 90 to 150%,
More preferably, it is 140%. 90% elongation at break
If it is less than 1, the Young's modulus tends to be high, and it is difficult to obtain the softness aimed at by the present invention. On the other hand, the elongation at break is 150%
If it exceeds, the stress at the yield point becomes low, and clear thick spots are not generated, but the fiber is easily elongated by the tension applied in the spinning process, and the uniformity of the fiber is undesirably reduced.

The low shrinkage polyester short fiber of the present invention has a boiling water shrinkage ratio and a dry heat shrinkage ratio at 180 ° C. of 1
~ 5%. In a spun yarn using a low-shrink polyester short fiber in which one or both of the boiling water shrinkage and the 180 ° C. dry heat shrinkage are less than 1%, when the woven or knitted fabric is post-heat-treated, the high shrink short fiber and the low shrink short. It is not preferable because the fibers are easily separated into two layers and a fluffy feeling is produced. On the other hand, in a spun yarn using a low-shrink polyester short fiber in which one or both of the boiling water shrinkage and the 180 ° C dry heat shrinkage exceed 5%,
When the woven or knitted fabric is post-heat treated, the woven or knitted fabric becomes a hard-handed woven or knitted fabric, which is not preferable.

The low shrinkage polyester staple fiber of the present invention has a Young's modulus of 50 g / d or less, more preferably 40 g / d or less, so that the object of the present invention exhibits excellent wool-like softness. It is preferable because it can be performed.

The low-shrinkage polyester short fiber of the present invention has a dry heat shrinkage of 180 ° C. after boiling water treatment of -2 to 3;
%, There is no flickering, excellent softness,
It is preferable to obtain a woven or knitted fabric having high resilience, and more preferably 0 to 3%.

The cross-sectional shape of the low-shrinkage polyester short fibers in the present invention is not limited to a round cross-section, but may be any cross-section such as a triangle, a pentagon, a flat, and a hollow. In particular, when the spinneret is formed of a slit, the spinning draft can be easily increased, and it is also preferable to form a modified cross section.

It is important that the high-shrinkage polyester short fiber in the present invention is composed of a high-shrinkage polyester obtained by copolymerizing a third component. It is preferable to use a specific copolymer polyester which is easy and can exhibit high shrinkage stress. The high shrinkage polyester short fiber composed of the high shrinkage polyester copolymerized with the third component, when blended with the low shrinkage polyester short fiber, the shrinkage ratio with the low shrinkage polyester short fiber in a post-process such as intermediate setting and dyeing. The difference can be increased.

The third component of the copolymer includes aromatic dicarboxylic acids such as isophthalic acid and 5-sodium sulfoisophthalic acid; aliphatic carboxylic acids such as sebacic acid and oxalic acid; and 2,2bis {4- (2- Glycols such as (hydroxyethoxy) phenyl} propane, 2,2bis {4- (2-hydroxyethoxy) phenyl} sulfone, spiro glycol and neopentyl glycol can be used.

In particular, the high-shrinkage polyester short fiber of the present invention is used for isophthalic acid and 2,2 bis-diphenyl terephthalate in order to obtain a high-quality woven or knitted fabric in terms of dyeing properties in addition to swelling, softness and light fastness. It is preferable to use a high-shrinkage polyester obtained by copolymerizing 4- (2-hydroxyethoxy) phenyl} propane, and more preferable to use a high-shrinkage polyester containing an amount satisfying the following formulas I, II and III at the same time. . P (a) + 1.5 × P (b) ≧ 8.5 −−− IP (a) + P (b) ≦ 18.0 −−−− II 1.0 ≦ P (b) ≦ 4.8 --- III (wherein, P (a) is the mole fraction (%) of isophthalic acid with respect to all the acid components in the copolymerized polyester, and P (b) is the mole fraction of all the glycol components in the copolymerized polyester. 2,
It is the mole fraction (%) of 2-bis {4- (2-hydroxyethoxy) phenyl} propane. ) Highly shrinkable polyesters include isophthalic acid and 2,2
A woven or knitted fabric having bis (4- (2-hydroxyethoxy) phenyl} propane as a copolymer component and satisfying Formula I, which can maintain a high dry heat shrinkage after boiling water treatment and is excellent in swelling feeling. And P (a) +1.5 in order to sufficiently increase the shrinkage.
× P (b) is more preferably 12 or more.

P (a) + 1.5 × P (b) ≧ 8.5 It is preferable that the formula II is satisfied.

P (a) + P (b) ≦ 18.0 --------- II Within this range, the melting point of the copolymerized polyester is 2
By maintaining the temperature at 10 ° C. or higher, the heat resistance can be improved, yarn breakage during spinning and sticking during stretching can be eliminated, and the yarn forming property can be improved. It is more preferable that P (a) + P (b) be 16.0 or less, because more stable spinning and drawing can be performed.

It is preferable that the formula III is satisfied.

1.0 ≦ P (b) ≦ 4.8 −−−−−−−− III Within such a range, excellent shrinkage characteristics, particularly dry heat shrinkage after boiling water treatment, are improved. Also, P (b) ≦ 4.8
By doing so, a woven or knitted fabric having excellent light fastness can be obtained, and more preferable results are obtained when P (b) is 4.6 or less.

In the present invention, isophthalic acid is copolymerized at a higher rate than 2,2bis {4- (2-hydroxyethoxy) phenyl} propane, so that the decrease in light fastness tends to be suppressed. Yes, even more preferred.

Here, as the base polyester, polyethylene terephthalate is preferred. The copolymerized polyester may contain diethylene glycol or the like in the main chain as long as it is produced as a by-product in the production process, or isophthalic acid and 2,2,2 as long as the high-shrink polyester short fiber of the present invention can be produced. A copolymer component other than bis {4- (2-hydroxyethoxy) phenyl} propane may be contained. Further, an additive such as titanium oxide may be added as long as the object of the present invention is not impaired.

In the present invention, the high shrinkage polyester short fiber has a boiling water shrinkage of 15% or less, more preferably 13% or less. If the boiling water shrinkage exceeds 15%, the shrinkage during twist setting of the spun yarn and drying of the warp with glue is too large, causing shrinkage spots and sink marks. Inevitably, processability decreases. The high shrinkage polyester short fiber of the present invention has a boiling water shrinkage of 15%.
The dry heat shrinkage after the boiling water treatment can be increased even in the following cases. Although the lower limit of the boiling water shrinkage is not particularly limited, it is preferably 5% or more in order to improve the process passability.

In the high-order process, a bulk-up process after forming a woven or knitted fabric is a very important factor. In other words, large shrinkage during bulk-up due to dry heat such as an intermediate set imparts swelling to the woven or knitted fabric,
This is because a soft woven or knitted fabric can be obtained. For this purpose, the high shrinkage polyester short fibers after boiling water treatment are treated with 180.
The dry heat shrinkage at 5 ° C. is 5 to 30%, more preferably 10 to 30%. If the dry heat shrinkage at 180 ° C. after the boiling water treatment is less than 5%, it is difficult to impart good bulkiness to the woven or knitted fabric when blended with the low shrinkage polyester short fiber. On the other hand, if the dry heat shrinkage at 180 ° C. after the boiling water treatment exceeds 30%, the shrinkage of the whole spun yarn becomes high, and the woven or knitted fabric becomes coarse and hard. The high shrinkage polyester short fiber in the present invention has a low boiling water shrinkage ratio, and is 1% after the boiling water treatment.
High dry heat shrinkage at 80 ° C, showing excellent shrinkage profile not found in conventional high shrinkage raw cotton.

The cross-sectional shape of the high-shrinkage polyester short fibers in the present invention is not limited to a round cross-section, but may be an irregular cross-section or a hollow cross-section. In particular, for the purpose of achieving weight reduction while satisfying tension and waist, a hollow cross section can be used.

The special polyester spun yarn of the present invention is obtained by blending a low-shrink polyester short fiber having a specific range of physical properties with a high-shrink polyester short fiber having an improved shrink profile obtained by copolymerizing a third component. Special polyester spun yarn, but its blend ratio is 30/7
It is important that it is between 0 and 80/20. If the proportion of the low-shrinkage polyester short fibers is less than 30% and the proportion of the high-shrinkage polyester short fibers exceeds 70%, the resulting woven or knitted fabric is undesirably coarse and hard. On the other hand, low shrinkage polyester short fiber exceeds 80%, and high shrinkage polyester short fiber is 20%.
Below, the resulting woven or knitted fabric is more flexible,
It is not preferable because the tension, waist and resilience are insufficient.

In the special polyester spun yarn of the present invention, the low-shrinkage polyester short fiber and the high-shrinkage polyester short fiber do not need to have the same denier, and can be mixed with different fineness. In particular, it is also possible to make the high-shrinkage polyester short fiber thick and improve the tension and waist.

Next, a preferred method for producing the special polyester spun yarn of the present invention will be described in detail.

The special polyester spun yarn of the present invention is obtained by spinning a chip made of polyester having an intrinsic viscosity [ηc] of 0.68 or more at a die surface depth of 70 mm or less and a spinning draft 5.
2,000 or more and melt spinning at a spinning speed of 2000 m / min or less.
A heat treatment is performed in a tension state of 5%, and then a chip made of a low-shrinkage polyester short fiber which has been shortened and a high-shrinkage polyester obtained by copolymerizing a third component is melt-spun. 125 to 1 with a relaxation rate of -2 to 2%
It can be obtained by blending a high-shrinkage polyester short fiber which has been heat-treated at 80 ° C. for 3 seconds or more and then shortened in a ratio of 30/70 to 80/20.

In order to obtain a low-shrink polyester short fiber in the present invention, a chip made of a polyester having an intrinsic viscosity [ηc] of 0.68 or more, a spinning draft of 5000 or more and a spinning speed of 2000 m or less at a die surface depth of 70 mm or less.
/ Min or less and melt-spun, and the undrawn yarn
It is heat-treated at 200 ° C. under a tension of 1 to 5%, and then shortened to obtain a short fiber.

As described above, in the present invention, a chip made of polyester having an intrinsic viscosity [ηc] of 0.68 or more is used.
More preferably, it is 7 or more. When the intrinsic viscosity [ηc] is less than 0.68, the spinning draft is 5000 or more and the spinning speed is 2000 m / min or less at a die surface depth of 70 mm or less. Low shrinkage polyester short fibers of 20% or less cannot be obtained. When the melt spinning and the tension heat treatment are performed using a chip made of polyester having an intrinsic viscosity [ηc] of 0.68 or more, a fiber having an elongation in a constant stress elongation region of 20% or less in a strong elongation curve is obtained. The reason is considered as follows. Polyester having an intrinsic viscosity [ηc] of 0.68 or more has a high melt viscosity, has a high elongational viscosity under a high draft of 5000 or more, and has a high spinning tension during thinning orientation, resulting in neck-like stretching. It is considered that the undrawn yarn characteristics approximate to POY (highly oriented undrawn yarn) or FOY (highly oriented high density yarn) at a spinning speed of 2000 m / min or less.

In the present invention, the die surface depth is set to 7
0 mm or less, and more preferably 50 mm or less. The spinneret surface depth in the present invention refers to a distance (L) from the spinneret surface to the lower end of the spinning head as shown in FIG. When the mouth surface depth exceeds 70 mm, a rainy season in May occurs immediately below the mouth surface, which undesirably deteriorates the spinnability.

In the present invention, the spinning draft is 5000
And more preferably 6000 or more. The spinning draft referred to in the present invention is a value obtained by dividing the spinning speed (m / min) by the linear discharge speed (m / min) of the polymer discharged from the die discharge hole. Spinning draft is 50
If it is less than 00, it becomes difficult to produce a fiber having an elongation level (120 to 170%) and a birefringence level (0.025 to 0.070) close to POY at a spinning speed of 2000 m / min or less.

In the present invention, the spinning speed is set to 200.
0 m / min or less. Spinning draft 5000
In the above, when the spinning speed exceeds 2,000 m / min, the yarn breaks easily. Therefore, in the present invention,
A low-speed melt spinning device can be used effectively.

In order to obtain a low-shrink polyester short fiber according to the present invention, the highly oriented undrawn yarn is dried at 14 ° C.
The heat treatment is performed at 0 to 200 ° C. under a tension of 1 to 5%. When the dry heat treatment temperature is lower than 140 ° C., the boiling water shrinkage rate is 1
It is difficult to make both the dry heat shrinkage at 80 ° C. less than 5%. On the other hand, when the dry heat treatment temperature exceeds 200 ° C., the tow containing water is easily softened, and the strength of the low-shrinkage polyester short fiber becomes extremely low, which is not preferable. On the other hand, if the tension ratio is less than 1%, the fibers are sagged, making it difficult to carry out a uniform heat treatment, and lowering the running stability, which is not preferable. On the other hand, if the tension ratio exceeds 5%, the Young's modulus increases, neck stretching tends to occur, and thick and thin spots are generated.

The low-shrinkage polyester short fiber in the present invention can be obtained by drying, crimping and cutting after the above-mentioned tension heat treatment.

The high-shrink polyester short fiber according to the present invention is obtained by melt-spinning a high-shrink polyester obtained by copolymerizing a third component, stretching the obtained unstretched yarn, and subsequently reducing it by -2% to
Heat-treated at 125-180 ° C. for 3 seconds or more at a 2% relaxation rate,
Thereafter, it can be obtained by shortening the fiber. In particular,
Melt spinning is performed using a high-shrinkable polyester obtained by copolymerizing the third component, the yarn is drawn while being taken up at a predetermined speed, and then temporarily stored in a can. While pulling out a plurality of the obtained subtows, it is stretched in a commonly used liquid bath under high temperature and high magnification, and the stretched fiber is continuously stretched at a relaxation rate of -2 to 2% to 125 to 18%.
After heat treatment at 0 ° C. for 3 seconds or more, the tow is inserted into the crimper, crimped, applied with a predetermined treating agent, and cut with a cutter.

As the highly shrinkable polyester, isophthalic acid and 2,2bis {4- (2-hydroxyethoxy) phenyl} propane are preferably used as copolymer components, and the following formulas I, II and III are simultaneously satisfied. More preferably, the amount is contained.

P (a) + 1.5 × P (b) ≧ 8.5 −−− IP (a) + P (b) ≦ 18.0 −−−− II 1.0 ≦ P (b) ≦ 4.8 --- III (where P (a) is the mole fraction (%) of isophthalic acid with respect to all the acid components in the copolymerized polyester, and P (b) is the total fraction in the copolymerized polyester. 2, relative to the glycol component
It is the mole fraction (%) of 2-bis {4- (2-hydroxyethoxy) phenyl} propane. In producing the high-shrink polyester short fiber of the present invention, what is important is a relaxation rate of −2 to 2% and 125 to 180 ° C.
If the relaxation rate is less than -2%, winding of the single yarn around the heating roll or breakage of the yarn frequently occurs during the heat treatment, and the yarn formability is greatly reduced. On the other hand, if the relaxation rate exceeds 2%, the tow path is difficult to stabilize, and it becomes difficult to apply a uniform heat treatment to the tow. The heat treatment temperature is 125
If the temperature is lower than 0 ° C., it is difficult to sufficiently suppress shrinkage when forming a spun yarn and drying by gluing, and low-temperature and low-speed processing is required, which is not preferable because productivity is reduced. The heat treatment temperature is more preferably 135 ° C. or higher. However, if the heat treatment temperature exceeds 180 ° C., shrinkage becomes too small, and sufficient shrinkage cannot be exhibited in a bulk-up step such as an intermediate setting. On the other hand, if the heat treatment time is less than 3 seconds,
Since a sufficient heat treatment cannot be performed, shrinkage variation between single fibers occurs, and shrinkage unevenness occurs.

By employing this method, the boiling water shrinkage of the high shrinkage polyester short fiber is reduced, and
The dry heat shrinkage at 80 ° C. can be increased, and a shrinkage profile superior to conventional high shrinkage raw cotton can be obtained.

The thus obtained low-shrink polyester short fiber and high-shrink polyester short fiber are mixed with 30 / 70-80.
The special polyester spun yarn of the present invention can be obtained by spinning at a ratio of / 20 and spinning according to an ordinary method.

[0048]

The present invention will be described in more detail with reference to the following examples. In addition, each characteristic value in an Example was implemented by the following measuring methods.

A. Strength-elongation curve Using a Tensilon tensile tester manufactured by Toyo Baldwin Co., a stress-strain curve was drawn under the conditions of a sample length of 2 cm, a pulling speed of 10 cm / min, and a chart speed of 20 cm / min. I asked. The elongation of the constant stress elongation region is obtained by drawing a line parallel to the X axis at the minimum stress portion in the constant stress elongation region ((b) in FIG. 1) and drawing a tangent line at the portion where the stress rises from the constant stress elongation region ( (C) in FIG. 1) It is determined from the elongation at the intersection.

B. Young's modulus Using a Tensilon tensile tester manufactured by Toyo Baldwin Co., the stress-strain curve up to the secondary yield point is enlarged and drawn under the conditions of a sample length of 2 cm, a tensile speed of 2 cm / min, and a chart speed of 10 cm / min. C. determined from tangent Birefringence (Δn) Birefringence (Δn) is the difference between the refractive index for light polarized perpendicular to the fiber axis and the refractive index for light polarized parallel to the fiber axis. Was measured by a conventional method using a polarizing microscope equipped with a compensator. (So-called compensator method) Boiling water shrinkage Grasp both ends of short fiber sample with clips, total 300m
An initial load of g / d is applied to determine the original length (L1). Loosen the clips sufficiently and treat them in a boiling water bath at 98 ° C under no load for 15 minutes.
/ D is applied, and the length (L2) after the treatment is measured. The boiling water shrinkage is determined according to the following equation. 1 test
Five times, the average value is determined.

B. Shrinkage of boiling water = {(L1-L2) / L1} × 100 (%) Dry heat shrinkage Grasp both ends of short fiber sample with clips, total 300m
An initial load of g / d is applied to determine the original length (L3). Loosen the gap between the clips sufficiently, treat in an oven at 180 ° C for 15 minutes under no load, and add a total of 300 mg to the treated sample.
/ D is applied, and the length (L4) after the treatment is measured. The dry heat shrinkage is determined according to the following equation. 1 test
Five times, the average value is determined.

F. Dry heat shrinkage = {(L3-L4) / L3} × 100 (%) 180 ° C dry heat shrinkage after boiling water treatment Hold both ends of the short fiber sample with clips, loosen the gap between the clips sufficiently, treat in a boiling water bath at 98 ° C under no load for 15 minutes, and give a total of 300mg to the sample after air drying. Apply an initial load of / d and measure the length (L5) after the treatment. Next, loosen the space between the clips again, and treat the sample in an oven at 180 ° C. for 15 minutes under no load.
/ D is applied, and the length (L6) after the treatment is measured. The dry heat shrinkage at 180 ° C. after the boiling water treatment is determined according to the following equation. The number of tests is 15 times, and the average value is obtained.

180 ° C. dry heat shrinkage (%) after boiling water treatment =
{(L5−L6) / L5} × 100 Examples 1 to 9, Comparative Examples 1 to 5 The limiting viscosity [ηc] of the polyester chip, the discharge hole diameter of the spinneret, the spinning speed, the spinning draft, and the spinneret depth are shown in Table 1. In addition to the above, melt spinning was carried out at a spinning temperature of 300 ° C. and a discharge rate of 24.7 g / min using a spinneret having 48 discharge holes. Align the undrawn yarn,
After heat treatment was performed at 100,000 D under the conditions shown in Table 1, crimping was applied, dried, and then cut to 76 mm to obtain low shrinkage polyester short fibers of 3d × 76 mm having the physical properties shown in Table 1. Example 9 is a low-shrink polyester short fiber of 2.3d × 76 mm.

Further, after performing an esterification reaction using terephthalic acid / ethylene glycol and isophthalic acid / ethylene glycol slurry, adding a coloring inhibitor / ethylene glycol slurry, a polymerization reaction catalyst and a titanium oxide / ethylene glycol slurry. (0.1 wt% of titanium oxide based on the obtained copolymerized polyester)
Was added, and a solution of 2,2bis {4- (2-hydroxyethoxy) phenyl} propane / ethylene glycol was added, and polymerization was carried out by a usual method to obtain a chip of a highly shrinkable polyester. The isophthalic acid at this time was 7.0.
mol%, 2,2 bis {4- (2-hydroxyethoxy) phenyl} propane is 4 mol%, and P (a) +
1.5 × P (b) = 13 (specified value ≧ 8.5), P (a) + P
(b) = 11 (specified value ≦ 18.0), P (b) = 4 (1.0
≤ specified value ≤ 4.8). An undrawn yarn was spun from the obtained chip at a spinning temperature of 290 ° C. and a spinning speed of 1350 m / min using a spinneret having a discharge hole diameter of 0.23 mmφ and 36 holes. This undrawn yarn is drawn into a tow of 100,000 D, drawn at a liquid bath drawing temperature of 90 ° C., at a draw ratio of 3.3 times, at a drawing speed of 150 m / min.
After a heat treatment at 5 ° C. for 5 seconds to give a mechanical crimp, the fiber was cut and 3d × 76 mm. 1
A high shrinkage polyester short fiber of 9.7% was obtained.

After blending the low-shrinkage polyester short fibers and the high-shrinkage polyester short fibers at a ratio of 50/50, a spun yarn was obtained to obtain a woven fabric with a weft.

In Comparative Example 1, the intrinsic viscosity [ηc] of the polyester chip was less than 0.68, the intrinsic viscosity [ηs] of the obtained low-shrink polyester short fiber was less than 0.66, and the breaking elongation was It exceeded 150%, the shrinkage rate of boiling water exceeded 5%, and thick and thin spots were generated, resulting in poor quality woven fabric.

In Comparative Example 2, the intrinsic viscosity [ηc] of the polyester chip was less than 0.68, and the intrinsic viscosity [ηs] of the obtained low-shrink polyester short fiber was less than 0.66;
In addition, the elongation at break exceeded 150%, the shrinkage ratio of boiling water and the shrinkage ratio of dry heat were both less than 1%, and the fabric had a fluffy feeling.

In Comparative Example 3, the spinneret surface depth exceeded 70 mm, pulsation occurred immediately below the spinneret, and stable spinning was not possible.

In Comparative Example 4, the elongation at break of the low-shrinkage polyester short fiber exceeded 150%, and when the card was passed through, stretching occurred, and only a thick and thin spun yarn was obtained.

In Comparative Example 5, the spinning speed exceeded 2,000 m / min, yarn breakage occurred at the spinning stage, and stable spinnability was not obtained.

On the other hand, Examples 1 to 3 satisfying the requirements of the present invention
From No. 9, a woven fabric having an excellent swelling feeling and an extremely soft surface touch, as well as good tension and waist and high resilience was obtained.

[0062]

[Table 1] Examples 10 to 14, Comparative Examples 6 to 9 A polyester chip having an intrinsic viscosity [ηc] of 0.74 was
Using a spinneret having a discharge hole diameter of 1.8 mmφ and a discharge hole number of 48 holes, melting at a die surface depth of 20 mm, a spinning temperature of 300 ° C., a discharge amount of 28.8 g / min, a spinning speed of 1750 m / min, and a spinning draft of 8750. The spinning was carried out. The unstretched yarn is aligned, adjusted to 100,000 D, heat-treated under the conditions shown in Table 2, crimped, dried, and cut to 76 mm to obtain a low 3d × 76 mm physical property shown in Table 2. Shrinkable polyester short fibers were obtained.

Further, the low-shrinkage polyester short fibers are:
The same high shrinkage polyester staple fiber as in Example 21 was mixed with 50 /
After blending at 50, the yarn was used as a spun yarn to obtain a woven fabric using the process.

In Comparative Example 6, since the stretch ratio in the heat treatment of the low-shrink polyester short fibers exceeded 5%,
Since the elongation at break is less than 90%, the shrinkage in boiling water and the shrinkage in dry heat both exceed 5%, and the Young's modulus is high, the obtained woven fabric is hard, lacking swelling and softness. Only textiles were obtained.

In Comparative Example 7, the stretch ratio in the heat treatment of the low-shrink polyester short fibers was less than 1%, the running of the tow became unstable, and stable heat treatment was not possible.

In Comparative Example 8, the heat treatment temperature of the low-shrink polyester short fiber was less than 140 ° C., the boiling water shrinkage ratio and the dry heat shrinkage ratio both exceeded 5%, and the obtained woven fabric had a swelling feeling and softness. Only a hard woven fabric lacking in feeling was obtained.

In Comparative Example 9, since the heat treatment temperature of the low-shrinkage polyester short fibers exceeded 200 ° C., toe sticking occurred on the HD (heating roll), and stable heat treatment could not be performed.

On the other hand, Embodiment 10 which satisfies the requirements of the present invention
From No. 14 to 14, a woven fabric having excellent swelling feeling and extremely soft surface touch, as well as good tension and waist and high resilience was obtained.

[0069]

[Table 2] Examples 15 to 26, Comparative Examples 10 to 15 A polyester chip having an intrinsic viscosity [ηc] of 0.74,
Using a spinneret having a discharge hole diameter of 1.8 mmφ and the number of discharge holes is 48 holes, melting at a die surface depth of 20 mm, a spinning temperature of 300 ° C., a discharge amount of 24.7 g / min, a spinning speed of 1500 m / min, and a spinning draft of 8750. The spinning was carried out. The undrawn yarn is aligned and adjusted to 100,000 D, heat-treated under the conditions of an HD temperature (heat treatment temperature) of 165 ° C. and an HD stretch ratio of 2.5%, crimped, dried and cut into 76 mm. The intrinsic viscosity [ηs] was 0.71, constant elongation elongation 4%, elongation at break 118%, boiling water shrinkage 2.4%, dry heat shrinkage 2.5%, Young's modulus 35 g / d, A low-shrink polyester short fiber of 3d × 76 mm having a dry heat shrinkage of 0.2% after the boiling water treatment was obtained.

Further, a highly shrinkable polyester chip having a copolymer component changed as shown in Table 3 was used to form a discharge hole having a diameter of 0.23 mmφ.
The undrawn yarn was spun at a spinning temperature of 290 ° C. and a spinning speed of 1350 m / min using a spinneret having 36 holes. This undrawn yarn is drawn into a tow of 100,000 D, drawn at a liquid bath drawing temperature of 90 ° C., at a draw ratio of 3.3 times, at a drawing speed of 150 m / min, and after drawing, HD temperature (heat treatment temperature), HD relaxation rate, HD After the heat treatment was performed by changing the heat treatment time as shown in Table 3 and mechanical crimping was applied, the fiber was cut to obtain a 3d × 76 mm high-shrink polyester short fiber.

In Comparative Example 9, a low-temperature, low-magnification stretched, high-shrink polyester obtained by using a normal polyethylene terephthalate unstretched yarn (spinning speed: 1350 m / min) at a liquid bath stretching temperature of 70 ° C. and a stretching ratio of 2.9 was used. It is a short fiber.

After blending the above-mentioned low-shrinkage polyester short fiber and high-shrinkage polyester short fiber at a ratio of 50/50, a spun yarn was obtained to obtain a woven fabric having a weft.

Comparative Example 10 is a low-temperature, low-magnification stretched, high-shrinkage polyester staple fiber, so that the boiling water shrinkage rate greatly exceeds 15%. , The productivity was low, the dry heat shrinkage after the boiling water treatment was extremely low, and the bulkiness in the bulk-up step was extremely low.

In Comparative Example 11, the HD temperature (heat treatment temperature) was less than 125 ° C., the boiling water shrinkage exceeded 15%, and shrinkage spots occurred in the gluing and drying step after spinning, so that low-temperature and low-speed processing was required. In addition to the low productivity, the dry heat shrinkage after the boiling water treatment exceeded 35%, and the obtained woven fabric had a rough and hard feeling.

In Comparative Example 12, the HD temperature exceeded 180 ° C., and the dry heat shrinkage after the boiling water treatment was less than 15%.
Only woven fabrics with little swelling were obtained.

In Comparative Example 13, since the HD relaxation rate exceeded 2%, the running stability of the tow was poor, and the tow was wrapped.

In Comparative Example 14, since the HD relaxation rate was less than -2%, breakage of single yarn occurred, tow winding occurred, and operability was poor.

In Comparative Example 15, the HD heat treatment time was less than 3 seconds, the heat treatment was insufficient, the shrinkage ratio of boiling water greatly exceeded 15%, and the shrinkage unevenness occurred in the gluing and drying process after spinning. In addition to the need for treatment, the productivity was low, and the dry heat shrinkage after boiling water treatment exceeded 35%, and only a woven fabric having a hard feel was obtained.

On the other hand, Embodiment 15 which satisfies the requirements of the present invention
From No. 26 to 26, a woven fabric having an excellent swelling feeling and an extremely soft surface touch, as well as good tension and waist and high resilience was obtained.

[0080]

[Table 3] Examples 27 and 28, Comparative Examples 16 and 17 Polyester spinning at a blending ratio shown in Table 4 using the short fibers of Example 3 as low-shrink polyester short fibers and the short fibers of Example 20 as high-shrink polyester short fibers. Yarn was obtained. A woven fabric was obtained using the spun yarn as a weft.

Comparative Example 16 was a polyester spun yarn in which the blend ratio of the low-shrinkage polyester short fiber was less than 30%, and a woven fabric having a core and a hard feel was obtained.

Comparative Example 17 is a polyester spun yarn in which the blending ratio of the low-shrinkage polyester short fibers exceeded 80%.
The obtained woven fabric was too soft and had no tension and waist.

[0083]

[Table 4]

[0084]

The special polyester spun yarn of the present invention comprises a low-shrink polyester short fiber having a high intrinsic viscosity, a specific shrinkage range and a low Young's modulus, and a high-shrink polyester short fiber having an improved shrink profile. Is a special polyester spun yarn that is able to obtain a woven and knitted fabric that has excellent swelling feeling and extremely soft surface touch, as well as good tension and waist and high resilience, It is extremely practical. In addition, the special polyester spun yarn of the present invention is a low-shrinkage polyester short fiber that can be produced by a specific heat treatment means that spins a polymer having a high intrinsic viscosity at a high draft and at a practically low spinning speed and has a good spinning property. Since a polymer containing a specific copolymer component is spun and drawn, and is composed of high-shrinkage polyester short fibers that can be produced by a specific heat treatment means having good spinnability, it is possible to obtain stable spinnability.

[Brief description of the drawings]

FIG. 1 is an illustration of a strong elongation curve illustrating a constant stress elongation region.

FIG. 2 is a schematic view of a spinning device for explaining a die surface depth.

[Explanation of symbols]

1: Strength and elongation curve of POY having constant stress elongation region 2: Strength and elongation curve of low shrinkage polyester short fiber of the present invention 3: Other strong and elongation curve of low shrinkage polyester short fiber of the present invention i: Constant stress Elongation area b: Line parallel to the X axis of the minimum stress part in the constant stress elongation area C: Tangent line of the part where stress rises from the constant stress elongation area 4: Spinning head 5: Spinneret

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI D01F 6/84 301 D01F 6/84 301J

Claims (7)

[Claims] 1. An intrinsic viscosity [ηs] of 0.66 or more, a constant stress elongation area elongation of 20% or less, a breaking elongation of 90 to 150%, a boiling water shrinkage rate of 180 ° C. and dry heat shrinkage of 180 ° C. Low-shrinkage polyester short fiber having a percentage of 1 to 5%, and a high-shrinkage polyester obtained by copolymerizing the third component. Boiling water shrinkage is 15% or less, and 180 ° C dry heat shrinkage after boiling water treatment is 5%. A high shrinkage polyester short fiber that is ~ 30%,
Special polyester spun yarn characterized by being blended at a ratio of 30/70 to 80/20. 2. A low-shrinkage polyester short fiber having a Young's modulus of 5
The special polyester spun yarn according to claim 1, wherein the yarn is 0 g / d or less. 3. The special polyester spun yarn according to claim 1, wherein the low heat shrinkage polyester short fiber has a dry heat shrinkage at 180 ° C. after boiling water treatment of -2 to 3%. 4. The high-shrinkable polyester obtained by copolymerizing isophthalic acid and 2,2bis {4- (2-hydroxyethoxy) phenyl} propane. Special polyester spun yarn according to the item. 5. The high-shrinkable polyester has the following formula I, II, II
The special polyester spun yarn according to claim 4, wherein an amount satisfying I at the same time is copolymerized. P (a) + 1.5 × P (b) ≧ 8.5 −−− IP (a) + P (b) ≦ 18.0 −−−− II 1.0 ≦ P (b) ≦ 4.8 ------ III (where P (a) is the mole% of isophthalic acid, P
(b) is 2,2bis {4- (2-hydroxyethoxy)
Phenyl モ ル propane mole%) 6. A chip made of polyester having an intrinsic viscosity [ηc] of 0.68 or more, a spinning draft of 5,000 or more, and a spinning speed of 2,000 m / m.
Minutes or less and melt-spun.
A heat treatment is performed at 40 to 200 ° C. under a tension of 1 to 5%, and then a chip made of a short shrinkage polyester short fiber which has been shortened and a high shrinkage polyester obtained by copolymerizing a third component is melt-spun. After stretching the undrawn yarn,
Heat-treated at 125-180 ° C. for 3 seconds or more at a relaxation rate of ２2%, and then blended with short-shortened high-shrink polyester short fibers at a ratio of 30 / 70-80 / 20. Method for producing polyester spun yarn. 7. The special polyester spun yarn according to claim 6, wherein the highly shrinkable polyester is obtained by copolymerizing isophthalic acid and 2,2bis {4- (2-hydroxyethoxy) phenyl} propane. Manufacturing method.