JP2008013862A - Cation dyeable polyester composite fiber, method for producing the same and fiber product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cation dyeable polyester composite fiber having cation dyeability excellent in clearness, able to be dyed under normal pressure by accurate and stable production method and excellent in tensile strength and elongation characteristics, and a product including the fiber. <P>SOLUTION: The polyester composite fiber is a core-sheath type one and comprises a modified polyester as the sheath part and a non-modified polyester as the core part. The modified polyester includes a polyethylene terephthalate as a main repeating unit, copolymerized with 1.0-3.0 mol% 5-sodium sulfoisophthalate as a dicarboxylic acid component and 3.0-10.0 mol% adipic acid, and has an intrinsic viscosity of 0.46-0.63. The non-modified polyester comprises ≥95 mol% ethylene terephthalate and has an intrinsic viscosity of 0.73-0.83. The polyester composite fiber is cation dyeable, has a volume ratio of the core part/the sheath part of 1/1-4/1, simultaneously satisfies a strength at break (DS) of ≥4.0cN/dtex and an elongation at break (DE) of ≥40% and satisfies ≥DS×(DE)<SP>1/2</SP>. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a polyester composite fiber excellent in dyeability and strong elongation characteristics of a cationic dye, a method for producing the same, and a fiber product including the composite fiber.

  Conventionally, various different materials have been used in the embroidery race field. For example, rayon or cotton is mainly used for the embroidery thread, and nylon is mainly used for the cup thread that is the back thread of the embroidery. Nylon and silk have been used for tulle lace, organdy, which is the base fabric for embroidery.

  In the embroidery field, since various fiber materials are used in this way, atmospheric dyeing is essential for dyeing, and each yarn requires a pre-dyeing process. There was a problem of being complicated.

  In order to remedy this problem, attempts have been made to use cationic dye-dyeable polyester fibers that can be dyed at normal pressure and have excellent sharpness for all embroidery threads and base fabrics. With the introduction of dyed polyester fibers, there is an increasing demand for embroidery products that are excellent in one-step dyeing after the embroidery process and sharpness.

  However, when the strength and elongation characteristics are low compared to normal polyester fibers, such as cationic dye-dyeable polyester fibers, the base fabric cannot withstand the entry of the embroidery thread during the embroidery process and breaks. It was easy to make holes and many problems occurred in process passability and merchantability.

  For example, in JP-A-06-166910 (Patent Document 1), as a countermeasure, the main repeating unit is composed of polyethylene terephthalate, and 1.5-3.5 mol% of 5-sodium sulfoisophthalic acid and 2.0 of adipic acid are used. ~ 7.0 mol% copolymerized modified polyester is disposed in the sheath, and 95 mol% or more unmodified polyester of polyethylene terephthalate is disposed in the core, and the area ratio of the core to the sheath in the fiber cross section is 4 Polyester fiber for embroidery having a fineness of 3 denier or less, a breaking strength (DS) of 4.0 g / denier or more, and a breaking elongation (DE) of 30% or more. Yes.

  However, in recent years, the speed of embroidery machines has increased, and when conventional embroidery polyester fibers are used, perforations in the base fabric have become conspicuous, which has been a problem.

Japanese Patent Laid-Open No. 04-174748 (Patent Document 2) discloses a multi-embroidery lace having a fineness of 50 denier or less, a tensile breaking elongation of 45 to 75%, and an initial tensile resistance of 950 kg / mm ² or more. A base fabric made of a filament is described. Further, JP 2004-277909 A (Patent Document 3) has a fineness of 55 dtex or less, a single yarn fineness of 3.0 to 7.0 dtex, and a tensile breaking elongation of 45. A base fabric made of multifilaments for embroidery lace having an initial tensile resistance of 800 kg / mm ² or more and less than 940 kg / mm ² and a boiling water shrinkage of 5% or less is described.

However, although these embroidery laces described in Patent Documents 2 and 3 can improve perforation, they are inferior in dyeability, so that normal dyeing is essential for dyeing, and each yarn is pre-dyed. There is a problem that the dyeing process is complicated.
Japanese Patent Laid-Open No. 06-166910 Japanese Patent Laid-Open No. 04-174748 JP 2004-277909 A

  An object of the present invention is to provide a cationic dyeable polyester composite fiber which is a cationic dye dyeable with excellent vividness and can be dyed at normal pressure by a reliable and stable production method, and at the same time has excellent high elongation properties. And providing a fiber product containing the fiber.

The basic constitution of the first invention of the present case is that the main repeating unit is composed of polyethylene terephthalate, the dicarboxylic acid component is 5-sodium sulfoisophthalic acid 1.0 to 3.0 mol%, and adipic acid 3.0 to A modified polyester copolymerized with 10.0 mol% and having an intrinsic viscosity of 0.46 to 0.63 is disposed in the sheath, and 95 mol% or more is composed of repeating units of ethylene terephthalate in the core, and the intrinsic viscosity is A core-sheath type composite spun fiber in which 0.73-0.83 unmodified polyester is arranged, the core / sheath volume ratio is 1 / 1-4 / 1, and the breaking strength is 4.0 cN / It is a cationic dyeable polyester composite fiber having a dtex or more, a breaking elongation of 40% or more, and a DS × (DE) ^1/2 of 27 or more.

  The basic constitution of the second invention of the present invention is that the main repeating unit is composed of polyethylene terephthalate, 5-sodiumsulfoisophthalic acid as a dicarboxylic acid component is 1.0 to 3.0 mol%, and adipic acid is 3. A modified polyester copolymerized with 0 to 10.0 mol% and having an intrinsic viscosity of 0.46 to 0.63 is disposed in the sheath, 95 mol% or more is composed of ethylene terephthalate repeating units, and the intrinsic viscosity is 0. After the unmodified polyester of .73 to 0.83 is arranged in the core and the core / sheath volume ratio of the core / sheath is 1/1 to 4/1, an unstretched yarn of the core-sheath composite spine is obtained. This is a method for producing a cationic dyeable polyester composite fiber, which is subjected to stretching and relaxation heat setting under the conditions satisfying) to 6).

1) 1.0 <DR1 <1.20
2) 75 ≦ HR1 ≦ 95
3) MDR × 0.60 <DR2 <MDR × 0.80
4) 100 ≦ HR2 ≦ 170
5) 150 ≦ HP ≦ 200
6) 0.85 <DR3 <1.00
Here, DR1: stretching ratio in the first stage stretching area MDR: maximum stretching ratio measured at a preheating temperature of 80 to 85 ° C. HR1: surface temperature of take-up roller in the first stage stretching area (° C.)
DR2: Stretch ratio in the second stage stretch zone HR2: Surface temperature (° C.) of the take-up roller in the second stage stretch zone
HP: Surface temperature of the hot plate in the third-stage stretch zone (° C.)
DR3: Stretch ratio in the third-stage stretch zone The basic configuration of the third invention of the present invention is a fiber product comprising at least a part of the polyester conjugate fiber described in claim 1.

  The present invention is a cationic dyeable polyester composite fiber that is cationic dyeable and capable of normal pressure dyeing and has improved strength and elongation properties, and a swimsuit using the cationic dyeable polyester composite fiber, Textile products such as sports inners, lingeries and foundations have vivid dyeability and good strength and elongation characteristics. In particular, an embroidery lace using the polyester fiber is a product which does not have a hole in the embroidery process and has good dyeing quality. Furthermore, by making both the embroidery thread and the base fabric cationically dyeable, one-step dyeing after the embroidery process is possible.

Hereinafter, the composite fiber of the present invention will be described in detail.
In the present invention, the modified polyester disposed in the sheath is dyeable with a cationic dye and exhibits atmospheric pressure dyeability, the main repeating unit is composed of polyethylene terephthalate, and 5-sodium sulfoisophthalic acid is 1 0.0 to 3.0 mol% and 3.0 to 10.0 mol% of adipic acid are copolymerized, and the intrinsic viscosity is 0.46 to 0.63.

  When the copolymerization amount of 5-sodium sulfoisophthalic acid is less than 1.0 mol%, the cation dyeability is lowered. When it exceeds 3.0 mol%, the strength and elongation characteristics of the fiber are lowered, and the base fabric is frequently perforated. When the copolymerization amount of adipic acid is less than 3.0 mol%, the dyeability in atmospheric dyeing is lowered. If it exceeds 10.0 mol%, the melting point will be lowered, and it will not be able to withstand the heat setting of about 200 ° C. in the processing step, resulting in perforation.

  When the intrinsic viscosity is less than 0.46, the difference in viscosity from the core component becomes too large, and it is difficult to stably obtain a uniform core-sheath composite cross section. If the intrinsic viscosity exceeds 0.63, the melt viscosity becomes too high due to the thickening action of 5-sodium sulfoisophthalic acid, and the yarn-making property deteriorates.

  The unmodified polyester polymer disposed in the core is polyethylene terephthalate having a copolymer component of less than 5 mol% and an intrinsic viscosity of 0.73 to 0.83. When the copolymerization component exceeds 5 mol%, it is difficult to obtain sufficient fiber elongation properties. Similarly, when the intrinsic viscosity is less than 0.73, it is difficult to obtain the strength and elongation characteristics of the fiber. When the intrinsic viscosity exceeds 0.83, the difference in viscosity from the sheath component becomes too large, and it becomes difficult to stably obtain a uniform core-sheath composite cross section.

  The volume ratio of the core / sheath to the core-sheath fiber cross section needs to be in the range of 1/1 to 4/1. When the ratio of the core component is lower than this range, the strength and elongation characteristics of the fiber are lowered, and perforation occurs in the embroidery process. On the contrary, when the ratio of the core component exceeds this range, it becomes difficult to stably obtain a uniform core-sheath composite cross section, and the atmospheric pressure cationic dyeability of the fiber is lowered.

The strong elongation characteristics of the cationic dyeable polyester composite fiber of the present invention are as follows: the breaking strength is 4.0 cN / dtex or more, the breaking elongation is 40% or more, and DS × (DE) ^1/2 is 27 or more. If the breaking strength is less than 4.0 cN / dtex, the breaking elongation is less than 40%, and DS × (DE) ^1/2 is less than 27, During the embroidery process, the thread cannot withstand the entry of the thread, and the resulting embroidery lace is perforated.

  Next, the manufacturing method of the polyester type composite fiber of this invention is demonstrated in detail. First, for spinning, the main repeating unit is composed of polyethylene terephthalate, and the dicarboxylic acid component is 1.0 to 3.0 mol% of 5-sodium sulfoisophthalic acid and 3.0 to 10.0 mol% of adipic acid. A modified polyester that is polymerized and has an intrinsic viscosity of 0.46 to 0.63 is arranged in the sheath, and an unmodified polyester in which 95 mol% or more is composed of repeating units of ethylene terephthalate is arranged in the core, and the core A core-sheath type composite spinning having a volume ratio of the sheath portion of 1/1 to 4/1. At this time, the intrinsic viscosity of the polyester in the core portion needs to be 0.73 to 0.83.

  Subsequently, it is obtained by drawing an undrawn yarn as follows using a three-stage stretcher. First, the draw ratio in the first-stage draw zone is set to a range of more than 1.0 times and less than 1.2 times, which is a ratio at which the yarn does not sag. Next, the film is heated with a take-up roller in the first-stage stretching zone heated to 75 to 95 ° C., and stretched at a magnification in the second stretching zone that exceeds 0.60 times the MDR and less than 0.80 times. Heat setting is performed with a take-off roller in the second stretching zone heated to ˜170 ° C. Thereafter, in the third-stage stretching region, heat setting is performed by bringing it into contact with a hot plate at 150 to 200 ° C. while relaxing in the range of more than 0.85 times and less than 1.00 times.

  If the draw ratio of the first stage drawing region is 1.0 or less, yarn slack occurs and winding around the roller occurs. On the other hand, if it is 1.2 times or more, stretched spots are generated and the quality after dyeing is lowered.

  The surface temperature of the take-up roller in the first-stage stretching region is in the range from the glass transition temperature of the core component polyester having a relatively high glass transition temperature of the polymer to (glass transition temperature + 20 ° C.), that is, 75 ° C. or more. , 95 ° C. or less. If the surface temperature of the take-up roller in the first-stage drawing region is outside this range, drawing spots are generated and the quality after dyeing is lowered.

When the draw ratio in the second-stage drawing region is 0.60 or less of MDR, the breaking strength of the fiber is excessively lowered and DS × (DE) ^1/2 cannot be maintained at 27 or more. On the other hand, if the MDR is 0.80 or more, the breaking elongation of the fiber is excessively lowered, and DS × (DE) ^1/2 cannot be maintained at 27 or more.

  The surface temperature of the take-up roller in the second stage stretching region is 100 to 170 ° C. When the temperature is lower than 100 ° C., the fiber unevenness is deteriorated and the dyeing quality is also inferior. When the temperature exceeds 170 ° C., the yarn swaying in the relaxation region becomes severe and yarn breakage is likely to occur.

The surface temperature of the hot plate in the third stage drawing zone is 150 to 200 ° C. When the temperature is lower than 150 ° C., yarn swaying due to a decrease in tension in the relaxation region becomes severe, and yarn breakage is likely to occur. When the temperature exceeds 200 ° C., the strength and elongation characteristics of the fiber are deteriorated, DS × (DE) ^1/2 cannot be maintained at 27 or more, and further cracks are generated.

  The draw ratio in the third stage drawing region needs to be in the range of more than 0.85 times and less than 1.00 times, that is, the relaxation region. In this relaxed state, the elongation at break can be increased without lowering the breaking strength of the fiber by heat setting using a hot plate. When the draw ratio in the third stage drawing region is 0.85 times or less, the tension drop is increased and the winding becomes unstable. On the other hand, if it is 1.00 times or more, the breaking strength is maintained, but the breaking elongation is lowered, and the effect of the present invention cannot be obtained.

  In addition, textile products such as swimwear, sports inners, lingerie, foundations and embroidery laces containing the cationic dyeable polyester composite fiber of the present invention may be used alone or in combination with the polyester composite fiber of the present invention. Although it may contain fibers, in order to reduce the perforation of the base fabric and improve the dyeing quality, the polyester-based composite fiber of the present invention is contained in 50% by mass in the base fabric constituting the embroidery lace. It is preferable to include the above.

  Furthermore, the combination of the base fabric using the cationic dyeable polyester composite fiber of the present invention and the embroidery thread using the cationic dyeable polyester fiber enables one-step dyeing after the embroidery process.

Hereinafter, the present invention will be specifically described with reference to Examples 1 to 5 and Comparative Examples 1 to 3. In addition, each evaluation followed the following method.
(Intrinsic viscosity of polymer [η])
The polymer was dissolved in a 1: 1 mixed solvent of phenol and tetrachloroethane and measured at 25 ° C. with an Ubbelohde viscometer.

(Polymer melting point, glass transition temperature)
Using a DSC220 manufactured by Seiko Denshi Kogyo Co., Ltd., the temperature was increased at a rate of 10 ° C./min.

(Fiber breaking strength and breaking elongation)
Using an autograph SD-100-C manufactured by Shimadzu Corporation, a stress elongation curve was measured at a test length of 200 mm and a tensile speed of 200 mm / min, and the strength and elongation at the breaking point of the fiber were determined.

An unmodified polyester having a melting point of 256 ° C. is arranged on the core, and a modified polyester having a melting point of 242 ° C. copolymerized with 2.25 mol% of 5-sodium sulfoisophthalic acid and 5 mol% of adipic acid is arranged on the sheath. Part / sheath part = 2/1 (volume ratio), core-sheath type composite spinning was performed at 287 ° C. to obtain an undrawn yarn. At this time, the intrinsic viscosity of the unmodified polyester was 0.76, and the intrinsic viscosity of the modified polyester was 0.52. Next, the undrawn yarn was stretched under the following conditions using a three-stage stretcher as shown in FIG. 1 and subjected to relaxation heat setting, 40 dtex / 8f, breaking strength 4.25 cN / dtex, breaking elongation 46. A drawn yarn of 8%, DS × (DE) ^1/2 = 29.1 was obtained.

At this time,
DR1 = 1.011
HR1 = 82 ° C
DR2 = 2.627 (MDR × 0.65)
HR2 = 130 ° C
HP = 185 ° C
DR3 = 0.954
However, DR1: Stretch ratio in the first stage stretch zone
MDR: Maximum draw ratio measured at a preheating temperature of 80 to 85 ° C
HR1: surface temperature (° C.) of the take-up roller in the first stage drawing zone
DR2: Stretch ratio in the second stage stretch zone
HR2: surface temperature of take-up roller in second-stage stretch zone (° C.)
HP: Surface temperature of the hot plate in the third-stage stretch zone (° C.)
DR3: Stretch ratio in the third stage stretching region.

  Next, using this drawn yarn, a tulle lace base fabric was produced with a warp knitting machine, and a double yarn of cationic dyeable polyester filament (135 dtex / 48 filament) and a high-speed embroidery machine (Saurar) 3 pieces of tulle lace having a length of 35 cm and a width of 14 m were produced. When the number of perforations in the entire area of the tulle race 3 obtained was inspected, no perforations were confirmed.

  Furthermore, when this tulle lace was dyed with a cationic dye (AIZEN CATHILON MARINEBLUE GPLH manufactured by Hodogaya Chemical Co., Ltd.) at 98 ° C. for 60 minutes, an embroidery product excellent in sharpness and leveling was obtained.

  A drawn yarn was obtained using the same polymer as in Example 1 except that the volume ratio of the core part to the sheath part was changed to 3/1. The drawn yarn obtained had good strength and elongation characteristics. When a tulle lace was produced using this drawn yarn, no opening was confirmed as in Example 1. Furthermore, when this tulle lace was dyed in the same manner as in Example 1, an embroidery product excellent in sharpness and levelness was obtained.

  A drawn yarn was obtained using the same polymer as in Example 1 except that the intrinsic viscosity of the unmodified polyester as the core component was changed to 0.80. The drawn yarn obtained had good strength and elongation characteristics. When a tulle lace was produced using this drawn yarn, no opening was confirmed as in Example 1. Furthermore, when this tulle lace was dyed in the same manner as in Example 1, an embroidery product excellent in sharpness and levelness was obtained.

  A drawn yarn was obtained in the same manner as in Example 1 except that the modified amount of 5-sodium sulfoisophthalic acid relative to the modified polyester as the sheath component was changed to 1.5 mol%. The intrinsic viscosity of the unmodified polyester at this time was 0.57.

  The drawn yarn obtained had good strength and elongation characteristics. When a tulle lace was produced using this drawn yarn, no opening was confirmed as in Example 1. Furthermore, when this tulle lace was dyed in the same manner as in Example 1, an embroidery product excellent in sharpness and levelness was obtained.

  A drawn yarn was obtained in the same manner as in Example 1 except that the modified amount of adipic acid relative to the modified polyester as the sheath component was changed to 10 mol%. The intrinsic viscosity of the unmodified polyester at this time was 0.54. The drawn yarn obtained had good strength and elongation characteristics. When a tulle lace was produced using this drawn yarn, no opening was confirmed as in Example 1. Furthermore, when this tulle lace was dyed in the same manner as in Example 1, an embroidery product excellent in sharpness and levelness was obtained.

[Comparative Example 1]
A drawn yarn was obtained using the same polymer as in Example 1 except that the volume ratio between the core and the sheath was changed to ½. However, the breaking strength of the drawn yarn was as low as 3.31, and DS × (DE) ^1/2 was a low value of 22.5. A tulle lace was produced using this drawn yarn in the same manner as in Example 1, and 16 holes were confirmed.

[Comparative Example 2]
A drawn yarn was obtained in the same manner as in Example 1 except that the intrinsic viscosity of the unmodified polyester as the core component was changed to 0.65. However, the breaking strength of the drawn yarn was slightly low at 3.72, and DS × (DE ) ^1/2 also became a low value of 24.9. Using this drawn yarn, a tulle lace was produced in the same manner as in Example 1, and 7 holes were confirmed.

[Comparative Example 3]
An undrawn yarn was obtained in the same manner as in Example 1. Next, the undrawn yarn was drawn under the following conditions using a two-stage twisting machine as shown in FIG. 2, and it was 40 dtex / 8f, breaking strength 4.30 cN / dtex, breaking elongation 35.2%, DS × (DE ) A stretched yarn of ^1/2 = 25.5 was obtained, but the elongation at break of the stretched yarn was slightly low, and DS × (DE) ^1/2 was also at a low level. Using this drawn yarn, a tulle lace was produced in the same manner as in Example 1, and five holes were confirmed.

At this time,
DR1 = 1.011
HR1 = 82 ° C
DR2 = 2.627 (MDR × 0.65)
HP = 160 ° C
However, DR1: Stretch ratio in the first stage stretch zone
MDR: Maximum draw ratio measured at a preheating temperature of 80 to 85 ° C
HR1: surface temperature (° C.) of the take-up roller in the first stage drawing zone
DR2: Stretch ratio in the second stage stretch zone
HP: Surface temperature of the hot plate in the third-stage stretch zone (° C.)
Met.

[Comparative Example 4]
Polyester having a melting point of 242 ° C. copolymerized with 2.25 mol% of 5-sodium sulfoisophthalic acid and 5 mol% of adipic acid was subjected to single spinning at 286 ° C. to obtain an undrawn yarn. The intrinsic viscosity of the modified polyester at this time was 0.54. Next, the unstretched yarn was stretched under the following conditions using a three-stage stretcher as shown in FIG. 1 and subjected to relaxation heat setting, but it was 40 dtex / 8f, breaking strength 3.68 cN / dtex, breaking elongation. Only a drawn yarn of 31.0%, DS × (DE) ^1/2 = 20.5 was obtained.

At this time,
DR1 = 1.011
HR1 = 81 ° C
DR2 = 2.919 (MDR x 0.72)
HR2 = 130 ° C
HP = 185 ° C
DR3 = 0.924
However, DR1: Stretch ratio in the first stage stretch zone
MDR: Maximum draw ratio measured at a preheating temperature of 80 to 85 ° C
HR1: surface temperature (° C.) of the take-up roller in the first stage drawing zone
DR2: Stretch ratio in the second stage stretch zone
HR2: surface temperature of take-up roller in second-stage stretch zone (° C.)
HP: Surface temperature of the hot plate in the third-stage stretch zone (° C.)
DR3: Stretch ratio in the third stage stretching region.
A tulle lace was produced using the drawn yarn in the same manner as in Example 1. As a result, 30 or more holes were confirmed.

[Comparative Example 5]
An unmodified polyester having a melting point of 256 ° C. was spun at 293 ° C. to obtain an undrawn yarn. The intrinsic viscosity of the unmodified polyester at this time was 0.75. Next, the undrawn yarn was drawn using a two-stage twisting machine as shown in FIG. 2, and it was 40 dtex / 8f, breaking strength 4.42 cN / dtex, breaking elongation 43.8%, DS × (DE) ^{1 /} 2 = was obtained 29.3 drawn yarn of. The obtained stretched tubular knitted fabric was dyed with a cationic dye (AIZEN CATHILON MARINEBLUE GPLH manufactured by Hodogaya Chemical Co., Ltd.) at 98 ° C. for 60 minutes.

The above results are summarized in Table 1. As is clear from Table 1, when Examples 1 to 5 and Comparative Examples 1 to 5 are compared, as one of the factors related to whether or not the tulle race can be perforated, the breaking strength (DS) and There is a breaking elongation (DE). When it sees about the strong elongation characteristic of the cationic dyeable polyester composite fiber of the present invention, it is necessary to satisfy the breaking strength of 4.0 cN / dtex or more and the breaking elongation of 40% or more. DS × (DE) ^{When 1/2} does not satisfy 27 or more, it can be understood that perforations occur in the obtained embroidery race.

  Further, from Table 1, in addition to the above-described strong elongation characteristics, for example, the volume ratio between the core and the sheath is within a range of 1/1 to 4/1. Since the volume ratio of the core part and the sheath part of 1 is 1 or less, the number of perforations is 2-3 times that of the other comparative examples 2 and 3, which is an important factor. I understand that.

It is the schematic which shows the whole content of a three-stage stretcher. It is the schematic which shows the whole content of a two-stage stretcher.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Undrawn yarn 2 Supply roller 3 Take-up roller in the first stage drawing area
4 Take-up roller in the second stage stretch zone
4 'Hot plate 5 in the second stage drawing zone 5 Hot plate in the third stage drawing zone 6 Take-up roller 7 in the third stage drawing zone

Claims (4)

The main repeating unit is composed of polyethylene terephthalate, and 1.0 to 3.0 mol% of 5-sodiumsulfoisophthalic acid and 3.0 to 10.0 mol% of adipic acid are copolymerized as the dicarboxylic acid component, and the intrinsic viscosity is An unmodified polyester having a modified polyester of 0.46 to 0.63 arranged in the sheath, 95 mol% or more of ethylene terephthalate repeating units in the core, and an intrinsic viscosity of 0.73 to 0.83 A core-sheath type composite spun fiber,
The volume ratio of the core part / sheath part is 1/1 to 4/1, the breaking strength (DS) is 4.0 cN / dtex or more, the breaking elongation (DE) is 40% or more, and DS × (DE) Cationic dyeable polyester composite fiber having a ^1/2 of 27 or more. The main repeating unit is composed of polyethylene terephthalate, and 1.0 to 3.0 mol% of 5-sodiumsulfoisophthalic acid and 3.0 to 10.0 mol% of adipic acid are copolymerized as the dicarboxylic acid component, and the intrinsic viscosity is A modified polyester of 0.46 to 0.63 is arranged in the sheath, and 95 mol% or more is composed of ethylene terephthalate repeating units, and an unmodified polyester having an intrinsic viscosity of 0.73 to 0.83 is used as the core. The core / sheath volume ratio of 1/1 to 4/1 is unstretched yarn and then stretched and relaxed heat set under the following conditions 1) to 6) A method for producing a cationic dyeable polyester composite fiber.
1) 1.0 <DR1 <1.20
2) 75 ≦ HR1 ≦ 95
3) MDR × 0.60 <DR2 <MDR × 0.80
4) 100 ≦ HR2 ≦ 170
5) 150 ≦ HP ≦ 200
6) 0.85 <DR3 <1.00
Here, DR1: stretching ratio in the first stage stretching area MDR: maximum stretching ratio measured at a preheating temperature of 80 to 85 ° C. HR1: surface temperature of take-up roller in the first stage stretching area (° C.)
DR2: Stretch ratio in the second stage stretch zone HR2: Surface temperature (° C.) of the take-up roller in the second stage stretch zone
HP: Surface temperature of the hot plate in the third-stage stretch zone (° C.)
DR3: Stretch ratio in the third stage stretch zone   A fiber product comprising at least a part of the cationic dyeable polyester composite fiber according to claim 1.   A textile product comprising the cationic dyeable polyester composite fiber according to claim 1 and the cationic dyeable polyester fiber.

Images