JP2007247107A - Bulky polyester conjugate fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a bulky polyester conjugate fiber having no surface quality defect by occurrence of band-like unevenness or streak-like defect in manufacturing a woven or knitted fabric by using a bulky polyester conjugate fiber having excellent stretchability and a bulky polyester conjugate fiber having excellent surface qualities and proper stretchability in a woven or knitted fabric. <P>SOLUTION: The bulky polyester conjugate fiber is a side by side type conjugate fiber of two kinds of intrinsic viscosities, comprises two or more single filament groups having different modification degrees and satisfies the following requirements: (A) stretch elongation percentage S is expressed by 20≤S≤150(%); and (B) bulkiness B is expressed by 71x10<SP>-3</SP>≤B≤200x10<SP>-3</SP>(m<SP>3</SP>/kg). The modification degree is calculated by the following formula. The modification degree of each single filament = major axis length/minor axis length. The major axis length is the diameter of the circumscribed circle of the section of each single filament. The minor axis length is a distance between two points of intersections of crosssectional conjugate interface and filament surface of each filament. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a bulky polyester composite fiber suitable for woven and knitted fabric applications. More specifically, when used for the front yarn and / or the back yarn of a knitted fabric, a bulky polyester composite fiber that exhibits excellent quality, soft texture and stretch characteristics without generating band-like spots or streak-like defects. About.

  In recent years, a stretch woven or knitted fabric imparted with a stretch performance among woven and knitted fabrics has been strongly demanded from its wearing feeling. In order to satisfy such a demand, for example, many knitted and knitted fabrics that have been given stretch properties by blending polyurethane fibers are used. However, polyurethane fibers are difficult to be dyed with polyester dyes, and the dyeing process becomes complicated, and there are problems such as embrittlement and deterioration of performance when used for a long time, especially when deployed on swimsuit knitted fabrics. Polyurethane fibers are brittle due to chlorine contained in water, and a sufficient function cannot be imparted. In order to avoid such drawbacks, application of polyester fiber crimped yarn instead of polyurethane fiber has been studied.

  In recent years, a 3GT crimped yarn has been proposed focusing on the stretch recovery property of polytrimethylene terephthalate (hereinafter referred to as 3GT). In particular, a large number of latently crimped fibers have been proposed in which two types of polymers are bonded side-by-side or eccentrically to develop crimps after heat treatment. However, when these 3GT-based composite fibers are used in a knitted fabric with a weak fabric binding force, the crimp phases of individual single yarns coincide with each other, resulting in band-like spots and streak-like defects. There was a problem that was restricted.

  Patent Document 1 discloses a side-by-side bicomponent composite fiber using 3GT as at least one component. This prior art discloses a method for dramatically improving the fineness variation value U% by specifying a polymer discharge condition and a cooling condition in the production of 3GT-based composite fiber. It is disclosed that, when used for wefts, it is possible to develop excellent quality, soft texture and stretch characteristics without generating band-like spots or streak-like defects. However, the composite fiber disclosed in the publication is effective in that the single yarn constituting the multifilament has a substantially round cross section and a low bulk height, and there is no variation in the single yarn cross section. When used, band-like spots and streak-like defects are generated due to matching of crimp phases of individual single yarns, and a knitted fabric of good quality cannot be obtained.

  Patent Document 2 discloses a side-by-side bicomponent composite fiber using 3GT as at least one component or using 3GT having different intrinsic viscosities for both components. This 3GT-based composite fiber is characterized by a soft texture and good crimp expression. This prior art describes that it has stretchability and stretch recovery, and can be applied to various stretch woven fabrics or bulky woven fabrics taking advantage of these properties. A PTT-based composite fiber having a high crimp before boiled water treatment and excellent in bulkiness is disclosed, but the composite fiber disclosed in the publication is a cross-sectional shape of a single yarn constituting a multifilament Are the same, have a low bulk height, and cause band-like spots and streaks in the knitted fabric.

Patent Document 3 and Patent Document 4 give a random feeling by joining the high-viscosity polyester component and the low-viscosity polyester component to the side-by-side type so that the composite ratio is different between the single yarns. In addition, a method is disclosed in which each single yarn of only a low-viscosity polyester component is mixed to give an appropriate feeling of swelling, bulkiness and firmness. However, the polyester composite fiber obtained by this method is unstable in yarn-making property because the strength and elongation levels differ between the single yarns. In addition, since the yarn itself contains single yarns without crimps, A feeling is emphasized. In addition, since single-component filaments of low-viscosity polyester components are spun at the same time, the ultimate viscosity difference between the high-viscosity polyester component and the low-viscosity polyester component cannot be increased from the standpoint of yarn production stabilization, and a bulge feeling with poor crimp expression There was no flat texture.
Further, Patent Document 5 discloses that a cross-section side-by-side polyester composite fiber having a difference in shrinkage due to a difference in polymer characteristics is composed of two or more single yarn groups having different composite joint surface states, and thus has a natural fiber-like swelling feeling and bulkiness. In addition, a method for imparting stretchability, tension waist and resilience is disclosed. However, since the invention described in the publication has a substantially multi-leafed cross section, the stretchability is weak and the bulkiness is low, the occurrence of band-like spots and streak-like defects cannot be improved in the knitted fabric.

Therefore, there is a strong demand for the emergence of composite fibers that are mainly used for knitting, have no band-like or streak-like defects, have good surface flatness and surface quality, and can exhibit appropriate stretch properties. It was done.
JP 2004-323991 A (Claims) JP 2002-061031 A (Claims) JP 01-266220 A (Claims) Japanese Unexamined Patent Publication No. 09-041233 (Claims) JP 2004-011067 A (Claims)

  An object of the present invention is to provide a bulky polyester composite fiber having no surface quality defects due to the occurrence of band-like spots or streak-like defects when producing a woven or knitted fabric using the bulky polyester composite fiber having good stretchability. Is to provide.

  It is another object of the present invention to provide a bulky polyester composite fiber that has a good surface quality in a woven or knitted fabric and can exhibit an appropriate stretch property.

  As a result of studying the above problems, the inventors of the present invention have dramatically improved the surface quality of the knitted fabric by controlling the cross-sectional shape of the single yarn constituting the multifilament and the bulk height of the composite fiber in the polyester composite fiber. As a result, the present invention has been completed.

That is, the subject of this invention is achieved by employ | adopting the item as described in the following (1)-(5).
(1) A bulky polyester characterized in that it is a side-by-side type composite fiber made of polyesters of two kinds of intrinsic viscosities, which is composed of two or more groups of single yarn groups having different degrees of irregularity, and satisfies the following requirements: Composite fiber.
(A) Expansion / contraction elongation S 20 ≦ S ≦ 150 (%)
(B) Bulk height B 71 × 10 ⁻³ ≦ B ≦ 200 × 10 ⁻³ (m ³ / kg)
However, the deformity is calculated by the following equation.
Deformation degree of each single yarn = major axis length / minor axis length Major axis length: diameter of circumscribed circle of the cross section of each single yarn Short axis length: between the two points of intersection of the cross-section composite interface of each single yarn and the fiber surface Distance (2) Bulky polyester composite fiber according to (1), wherein dispersion V _D of irregularity degree of single yarn satisfies the following requirement (C):
(C) 0.4 <V _D <150
However, the variance V _{D of the} irregularity is calculated by Equation 1.

(3) The bulky polyester composite fiber according to (1) or (2), wherein at least one component constituting the single yarn is polytrimethylene terephthalate.
(4) A fiber product comprising at least a part of the bulky polyester composite fiber according to any one of (1) to (3).
(5) A knit product, at least a part of which is made of the bulky polyester composite fiber according to any one of (1) to (3).

  According to the present invention, it is possible to provide a stretch woven or knitted fabric with good surface quality free from band-like spots and streak-like defects that could not be achieved by the prior art.

  The present invention will be described in detail below.

  The composite fiber of the present invention needs to take a form in which a high-viscosity polyester component and a low-viscosity polyester component are bonded to each other in order to obtain good crimp characteristics. By laminating polyesters with different viscosities to the side-by-side type, stress concentrates on the high viscosity side during spinning and drawing, so that the internal strain differs among the components. Therefore, the high-viscosity side contracts greatly due to the difference in elastic recovery rate after stretching and the difference in thermal shrinkage in the heat treatment step of the fabric, and distortion occurs in the single yarn to take the form of a three-dimensional coil. It can be said that the diameter of this three-dimensional coil and the number of coils per unit fiber length are determined by the shrinkage difference between the high-viscosity component and the low-viscosity component. In order to satisfy the coil crimp characteristics required as a stretch material Requires a difference in intrinsic viscosity of the polyester component.

  The intrinsic viscosity of the polyester component in the present invention is preferably 0.7 to 2.0 in the high viscosity component, and by making the intrinsic viscosity 0.7 or more, it is possible to produce a fiber having sufficient strength and elongation. It becomes easy. A more preferable intrinsic viscosity is 0.8 or more. Further, when the intrinsic viscosity is 2.0 or less, production stability is easily obtained. A more preferable intrinsic viscosity is 1.8 or less. On the other hand, the polyester component on the low viscosity side is preferable because the stable viscosity can be obtained by setting the intrinsic viscosity to 0.4 or more. More preferably, it is 0.50 or more. In order to obtain higher crimp characteristics, it is preferably 0.7 or less.

  Furthermore, by setting the difference in intrinsic viscosity between the high-viscosity component and low-viscosity component of the polyester component to 0.3 or more, it becomes a raw yarn excellent in crimping characteristics. This is preferable because it becomes a raw yarn. On the other hand, when the difference in intrinsic viscosity exceeds 1.5, the crimped property of the obtained yarn is good, but the spun yarn is bent excessively toward the high-viscosity component side, so that the yarn can be stably produced for a long time. It is not preferable. Therefore, in order to satisfy both stable yarn forming properties and stretch recovery properties, it is desirable that the difference in intrinsic viscosity is 0.3 or more and 1.5 or less.

  Here, the polyester component of the present invention is not particularly limited as long as it is a fiber-forming polyester having good interfacial adhesion between a high-viscosity component and a low-viscosity component and having a stable yarn-forming property. However, in consideration of mechanical properties, chemical properties, and raw material prices, polyethylene terephthalate (hereinafter referred to as PET), 3GT, and polybutylene terephthalate (hereinafter referred to as PBT) having fiber formability are preferable. In addition to 3GT, PET, and PBT, polylactic acid (PLA), those obtained by copolymerizing a third component thereof, or a mixed polymer thereof may be used.

  3GT in the present invention is 3GT in which 90 mol% or more is composed of a repeating unit of trimethylene terephthalate, and is a polyester obtained using 1,3-propanediol as a main glycol component. However, it may contain a copolymer component capable of forming another ester bond at a ratio of 10 mol% or less. Examples of copolymerizable compounds include dicarboxylic acids such as isophthalic acid, cyclohexanedicarboxylic acid, adipic acid, dimer acid, and sebacic acid, while glycol components include, for example, ethylene glycol, diethylene glycol, butanediol, neopentyl glycol, and cyclohexanedi Examples thereof include, but are not limited to, methanol, polyethylene glycol and polypropylene glycol. Further, titanium dioxide as a matting agent, silica or alumina fine particles as a lubricant, hindered phenol derivatives, coloring pigments and the like as antioxidants can be added as necessary.

  On the other hand, PET in the present invention is a polyester obtained by using terephthalic acid as a main acid component and ethylene glycol as a main glycol component, and 90 mol% or more consisting of repeating units of ethylene terephthalate. However, it may contain a copolymer component capable of forming another ester bond at a ratio of 10 mol% or less. Examples of copolymerizable compounds include dicarboxylic acids such as isophthalic acid, cyclohexanedicarboxylic acid, adipic acid, dimer acid, and sebacic acid, while glycol components include, for example, ethylene glycol, diethylene glycol, butanediol, neopentyl glycol, and cyclohexanedi Examples thereof include, but are not limited to, methanol, polyethylene glycol and polypropylene glycol. Further, titanium dioxide as a matting agent, silica or alumina fine particles as a lubricant, hindered phenol derivatives, coloring pigments and the like as antioxidants can be added as necessary.

  Moreover, PBT in this invention is PBT which 90 mol% or more consists of a repeating unit of tetramethylene terephthalate, and is a polyester obtained by using 1, 4- butanediol as the main glycol component. However, it may contain a copolymer component capable of forming another ester bond at a ratio of 10 mol% or less. Examples of copolymerizable compounds include dicarboxylic acids such as isophthalic acid, cyclohexanedicarboxylic acid, adipic acid, dimer acid, and sebacic acid, while glycol components include, for example, ethylene glycol, diethylene glycol, butanediol, neopentyl glycol, and cyclohexanedi Examples thereof include, but are not limited to, methanol, polyethylene glycol and polypropylene glycol. Further, titanium dioxide as a matting agent, silica or alumina fine particles as a lubricant, hindered phenol derivatives, coloring pigments and the like as antioxidants can be added as necessary.

In addition, PLA in the present invention is a polymer in which 90 mol% or more has — (O—CHCH ₃ —CO) n—) as a repeating unit, and is obtained by polymerizing lactic acid or an oligomer. However, a copolymerization component, a polyfunctional compound, etc. may be added in the range of 10 mol% or less.

  Moreover, it is preferable that the composite fiber of this invention is a composite fiber in which at least one component which comprises single yarn is 3GT, and the other component consists of another polyester. That is, a combination of 3GT and another polyester or a combination of 3GTs is preferable. The coil crimp characteristics of the fiber are dominated by the stretch characteristics of the high viscosity component with the low viscosity component as a fulcrum. Therefore, in order to obtain the coil crimp characteristics of the fiber that can express the soft feeling and bulkiness required for the stretch material, the polymer used for the high viscosity component is required to have particularly high extensibility and recoverability. The 3GT has the same mechanical properties and chemical properties as PET and PBT fibers, and is extremely excellent in stretch recovery and can exhibit good stretch performance.

  Next, the bulky polyester conjugate fiber of the present invention needs to be composed of two or more single yarn groups having different degrees of irregularity. Here, the irregularity defined in the present invention means the major axis length, which is the diameter of the circumscribed circle of the cross section of each single yarn, as shown in FIG. 1, and the intersection between the composite interface of the cross section of each single yarn and the fiber surface. The value divided by the short axis length, which is the distance between the two points, indicates that the larger the value, the flatter. For example, as illustrated in FIG. 2, the two or more single yarn groups having different irregularities indicate a case where two or more types of single yarns having different irregularities are mixed in the multifilament. As a result, the fabric is given firmness and firmness to give a unique texture, and a very favorable effect can be obtained on the surface of the fabric. As is well known, in a side-by-side type composite fiber yarn, the crimped phases of individual single yarns are matched, and it is easy to present a strongly converged appearance as if it were a spiral monofilament. Appears as streaks on the surface of the fabric, and at the same time, the texture becomes hard. Therefore, it is important to control the cross-sectional shape of the single yarns constituting the multifilament and to mix single yarns having different degrees of irregularity so that a bulky polyester composite fiber having a crimped phase shifted is important.

  Although the example of the cross-sectional shape of the single yarn of the polyester composite fiber in this invention is illustrated in FIG. 3, of course, it is not limited to what was illustrated.

Here, the dispersion V _D of the irregularity degree of the bulky polyester composite fiber of the present invention is defined by Formula 1, and is preferably in the range of 0.4 <V _D <150. By setting the dispersion of the irregularity in the range of 0.4 <V _D <150, the crimp phase can be shifted, and a random feeling of crimp expression and functionality can be imparted.

  The bulky polyester composite fiber of the present invention preferably has the same composite ratio and single yarn fineness of the two polyester components constituting the single yarn. When the composite ratio and the single yarn fineness are the same, variations in the strength and elongation between single yarns can be minimized, and stable yarn production and good quality and quality can be obtained. Note that the same composite ratio and single yarn fineness indicate that in the fiber cross section, the composite ratio indicates that the cross-sectional area ratios of the two polyester components constituting the single yarn are the same. It shows that the cross-sectional area of the yarn is the same, and the area ratio of each cross-sectional photograph is the same up to ± 3%. The composite ratio is preferably in the range of high viscosity component: low viscosity component = 80: 20 to 20:80 in terms of yarn production, expression of crimping performance and dimensional homogeneity of the coil in the fiber length direction, and 70: The range of 30-30: 70 is more preferable. Further, the single yarn fineness is not particularly limited, but a range of 0.3 to 5.0 dtex is obtained in that a soft feeling is obtained when the bulky polyester composite fiber of the present invention is made into a fabric, particularly a knitted fabric. Preferably, it is more preferable than the range of 0.3 to 3.0 dtex.

  Next, physical properties of the bulky polyester composite fiber of the present invention will be described.

  In the bulky polyester conjugate fiber of the present invention, it is noted that the stretch elongation rate is important for the ability to develop crimps under fabric restraint, and as shown in the formula described later, the load corresponding to the restraint force in the fabric. It was assumed that the crimping ability under fabric restraint could be expressed by the expansion / contraction elongation rate of the fiber cassette by suspending it in the fiber cassette and performing heat treatment. It indicates that the higher the stretch elongation rate, the higher the crimp expression ability, and it is necessary to be 20% or more and 150% or less in order to give an appropriate stretch. If the stretch / elongation rate is less than 20%, the stretch rate of the fabric becomes small, and if it exceeds 150%, the crimp is too strong and the surface quality of the fabric becomes poor. The higher the stretch / extension ratio, the better the stretch performance when it is made into a fabric, so it is preferably 40 to 150%, more preferably 50 to 150%. In order to achieve the stretch / extension rate as described above, as described above, a side-by-side type composite fiber made of polyesters having two intrinsic viscosities may be used. If the intrinsic viscosity is large, the stretch / extension rate is increased. Further, by using 3GT on one side, it is possible to obtain a composite fiber having a high expansion / contraction rate and rich in softness.

In addition, the bulky polyester conjugate fiber of the present invention has a high crimp height because the crimp phase is shifted between the constituting conjugate fibers. By increasing the bulk height, an appropriate swell can be provided, and a soft and repulsive fabric can be obtained. Furthermore, the displacement of the crimp phase enhances the torque dispersion effect due to the coil crimp, and a high-quality fabric can be obtained. The above effect is achieved at a ^bulk height of 71 × 10 ⁻³ to 200 × 10 ⁻³ m ³ / kg, preferably 80 × 10 ⁻³ to 200 × 10 ⁻³ m ³ / kg, more preferably 90 ×. 10 ⁻³ to 200 × 10 ⁻³ m ³ / kg. In order to achieve the above bulk height, as described above, a composite fiber composed of two or more single yarn groups having different deformities may be used. This point is different from the known technique, and it is possible to achieve both an excellent stretch / extension ratio and a high bulkiness.

  The bulky polyester composite fiber of the present invention preferably has a breaking elongation of 20 to 50%. By making the elongation at break 20% or more, the occurrence of stretch breaks can be suppressed, and industrially stable production becomes possible. Alternatively, when the elongation at break is 50% or less, good tear strength can be obtained in the fabric. A more preferable elongation at break is 25 to 45%.

  In addition, the bulky polyester conjugate fiber of the present invention preferably has a Wooster plaque U% (half inert) of 1.2% or less, which is an index of the thickness variation in the longitudinal direction of the yarn. Thereby, not only the occurrence of dyed spots on the fabric can be avoided, but also the shrinkage spots of the yarn when made into a fabric can be suppressed, and a beautiful fabric surface can be obtained. The Worcester plaque U% (half inert) is more preferably 1.0% or less, and still more preferably 0.8% or less.

  In addition, in order to overcome the fabric restraining force and stably crimp the coil, the temperature indicating the contraction stress and the maximum of the contraction stress may be an important characteristic. The higher the shrinkage stress is, the better the crimp developability under fabric restraint is, and the higher the temperature at which the maximum shrinkage stress is, the easier the handling in the finishing process. Therefore, in order to enhance the crimp development in the heat treatment step of the fabric, the temperature at which the shrinkage stress is maximized is 110 ° C. or higher, preferably 120 ° C. or higher, more preferably 125 ° C. or higher. It is 0.15 cN / dtex or more, preferably 0.18 cN / dtex or more.

  Subsequently, the manufacturing method of the bulky polyester composite fiber of this invention is demonstrated. The method for producing a polyester conjugate fiber according to the present invention is such that two different types of polyester components are made up of two or more groups of single yarn groups having different degrees of deformation using a composite spinning machine and a predetermined composite pack. A two-step method in which a composite base is bonded to a side-by-side mold using a simple die, the unstretched yarn is wound up, and then stretched to a predetermined breaking elongation with a normal stretching machine, or is wound up once It can also be produced by any one of the one-step methods in which stretching is continued. However, when quality stability and production stability in the longitudinal direction of the fiber are taken into consideration, production by the direct spinning drawing method (hereinafter referred to as DSD method) is most excellent.

  Generally, in order to obtain a side-by-side type composite fiber, for example, a die as shown in FIG. In order to obtain a composite fiber composed of n single yarns (n filaments), each polyester is weighed on the upper plate, and both polyesters merge on the lower plate to form a single yarn cross-sectional shape. In the conventional technique, since all of the n discharge holes in the lower plate have the same shape, it has been impossible to obtain a composite fiber having a variation in irregularity that is greater than a variation in normal production.

  In the present invention, the base used has the same cross-sectional area in the lower plate, but changes its shape. For example, as shown in FIG. If the round shape is 0, and the discharge hole 2 is elliptical so that the degree of irregularity is 3.0, it is possible to intentionally create composite fibers with irregularity variations. Can be controlled. Furthermore, it is possible to configure a multifilament composed of n single yarns from single yarns having different degrees of irregularity.

  The fabric form of the bulky polyester conjugate fiber of the present invention can be appropriately selected according to the purpose such as woven fabric, knitted fabric, nonwoven fabric, and cushioning material, and can be suitably used for shirts, blouses, pants, suits, blouses and the like. It is preferably used mainly for knitted products such as shirts, swimsuits, and innerwear as knitted fabrics. This is because when the bulky polyester conjugate fiber of the present invention is used for a knitted fabric having a weak fabric binding force, the crimped phases of individual single yarns do not coincide with each other, and band-like spots and streak-like defects are eliminated. This is because a fabric having a good surface quality can be provided. In the woven fabric, it may be used alone for warp and weft, may be used in combination with other yarns, and any method that exhibits the characteristics of the composite fiber of the present invention can be used.

Hereinafter, although an example is given and explained concretely, the present invention is not limited to an example. In addition, the measured value of the Example was measured with the following method.
(1) Intrinsic viscosity For 3GT, ηr is 0.8 g of o-chlorophenol (hereinafter abbreviated as OCP) having a purity of 98% or higher at 160 ° C. dissolved in 0.8 g of sample polymer and cooled to 25 ° C. Then, using an Ostwald viscometer, the relative viscosity ηr was determined by the following formula, and IV was calculated. For other polymers, 0.8 g of the sample polymer was dissolved in 10 mL of OCP having a purity of 98% or higher at 25 ° C., and the relative viscosity ηr was obtained from the following equation using an Ostwald viscometer at 25 ° C., and IV was calculated.
ηr = η / η ₀ = (t × d) / (t ₀ × d ₀ )
IV = 0.0242ηr + 0.2634
Here, η: viscosity of polymer solution η ₀ : viscosity of OCP t: drop time of solution (second)
d: density of the solution (g / cm ³ )
t ₀ : OCP fall time (seconds)
d ₀ : OCP density (g / cm ³ )
(2) Expansion / contraction elongation The heat treatment was performed by the method shown in FIG. 5, and the expansion / contraction elongation was defined by the following formula.
Expansion / contraction rate (%) = [(L ₁ −L ₀ ) / L ₀ ] × 100%
L ₀ : Hot water treatment at 90 ° C. for 20 minutes with a treatment load of 1.8 × 10 ⁻³ cN / dtex hung on a fiber cassette sampled by filing (1 m × 10 turns), after hot water treatment After removing moisture with the filter paper, the treatment load is removed, and drying is performed in a constant temperature and humidity chamber at 20 ° C. and 70% RH for 12 hours. An initial load of 1.8 × 10 ⁻³ cN / dtex was hung on the treated sample, and after measuring the cassette length L ₁ : L ₀ after 30 seconds, the initial load was removed and a heavy load of 88.2 × 10 ⁻³ cN / Fig. 6 is a perspective view of a device for measuring the bulk height B, and Fig. 7 is a sketch for explaining the measuring method by this device. Two cuts 6 are provided on the upper surface of the sample stage 1, the distance between the outer edges is set to 6 cm, a PET film 2 having a width of 2.5 cm and a thickness of 5 μm is passed over this cut, and a metal fitting with a pointer underneath 3 and load 4 are combined. The pointer of the metal fitting 3 is set so as to indicate the zero position of the scale 5 when the sample is not attached. The sample is wound up using a measuring machine having a circumference of 1 m so that the display fineness is 50000 dtex and the yarn length is 50 cm. Next, as shown in the front view (a) and the cross-sectional view (b) of FIG. 7, the obtained cassette 7 is inserted between the PET film 2 and the sample stage 1, and the sample that has shrunk is pulled to a cassette length of 25 cm. The cassette 7 is fixed as follows. The load 4 is set to 50 g in total with the metal fitting 3 with the pointer, and after applying the load slowly, L (cm) indicated by the pointer is read. The measurement is performed three times, and the bulk height B is calculated from the average L value according to the following equation.
B (m ³ / kg) = volume V in film / yarn weight W in film
V (m ³ ) = L ² /π×2.5×10 ⁻⁶
W (kg) = 50000 × (0.5 / 0.25) × (0.025 / 10000) × 10 ⁻³ = 0.25 × 10 ⁻³
(4) Strength and elongation Measured with Tensilon UCT-100 manufactured by Orientex as an initial load of 0.089 cN / dtex in accordance with JIS L1013 (1999).
(5) Wet heat shrinkage (boiling)
The wet heat shrinkage was measured by the following formula.
Wet heat shrinkage (%) = [(L ₁ −L ₀ ) / L ₀ ] × 100%
L ₀ : Case length in a state where a load of 0.176 cN / dtex is hung on a fiber case sampled by picking up (1 m × 10 turns) L ₁ : Put in 98 ° C. hot water with the load suspended After treating for 15 minutes, remove moisture with filter paper, and dry it for 30 minutes in a constant temperature and humidity chamber at 20 ° C. and 70% RH (6) Dry heat shrinkage (dry yield)
The dry heat shrinkage was measured by the following formula.
Dry heat shrinkage rate (%) = [(L ₁ −L ₀ ) / L ₀ ] × 100%
L ₀ : Case length in a state where a load of 0.176 cN / dtex is hung on a fiber case sampled by picking up (1 m × 10 turns) L ₁ : Placed in a high-temperature dryer at 160 ° C. while the load is hung For 15 minutes, after cooling the high-temperature dryer to 40 ° C and taking it out (7) Fluctuation rate (U%)
Using a Worcester tester UT-4CX manufactured by Twelvegar Worcester, a fineness variation chart (Diagram Mass) was obtained under the following measurement conditions, and at the same time, U% (half inert) was measured.
Yarn feeding speed: 200 m / min Measuring thread length: 200 m
Twister: S twist 12000 turns / min Disc tension strength: 10%
Scale: -10% to + 10%
(8) Fabric surface quality After winding the product, bulky polyester composite fiber stored at room temperature for 1 month is used for the front and back yarns, and 33 dtex PET yarn is used for the middle yarn to form a 28 gauge circular knitted cardboard structure. 50% at a bath ratio of 1: 100 using Tetraseal Navy Blue SGL 0.275% owf as a dye, Tetrocin PE-C 5.0% owf as an auxiliary agent, Nikka Sun Salt # 12001.0% owf as a dispersing agent Dyeing was performed at 15 ° C. for 15 minutes and further at 90 ° C. for 20 minutes. The sample after dyeing was subjected to a comprehensive sensory inspection for the presence of stained spots and streak-like defects, and evaluated according to the following four levels. The passing level is ◯ or higher.
○ ○: Very homogeneous and excellent quality ○: There are minor defects that can be shipped Δ: There are defects that cannot be shipped ×: There are serious defects that cannot be shipped (9) Stretch-back property The sensory evaluation was conducted by five skilled workers with a focus on stretch-back property, taking into account moderate resilience, stiffness, and resilience, and evaluated by a four-step judgment method. The passing level is ◯ or higher.
○: Excellent compared to conventional products ○: Good compared to conventional products △: Same level as conventional products ×: Inferior to conventional products Example 1
3GT with an intrinsic viscosity of 1.43 and PET with an intrinsic viscosity of 0.51 were melted at 285 ° C. and 260 ° C. using an extruder, respectively, and weighed with a pump. Three different types of single yarns with different degrees of shape of 2.5, 2.1, and 1.8 were introduced into the die to form 8 filaments each. Pump metering was performed so that the composite ratio was 3GT: PET = 50: 50. The pipe passage time of each polymer was 12 minutes for 3GT and 8 minutes for PET. The yarn discharged from the die was spun and drawn with the equipment shown in FIG. That is, after cooling and applying the oil, it is taken up by a first hot roller (hereinafter referred to as HR) 12 heated to 55 ° C. at a speed of 1250 m / min, and is temporarily wound up to 155 ° C. at a speed of 4200 m / min. Drawing to the heated second HR13, stretching and heat setting were performed. Further, after being drawn around two godet rollers (hereinafter referred to as GR) 15 and 16 at 4000 m / min, it was wound around a contact roller (hereinafter referred to as CR) 17 at a speed of 3980 m / min, as shown in FIG. A bulky polyester composite fiber of 56 dtex-24 filaments composed of three types of single yarns having different degrees of deformity was obtained. The property evaluation results of this bulky polyester composite fiber are as shown in Table 1, and very excellent fabric surface quality and stretch back properties were obtained.

Examples 2-11, Comparative Examples 1-5
Bulky polyester composite fibers were obtained by the DSD method under the production conditions shown in Tables 1 and 2. The composite fibers having the irregularities shown in Tables 1 and 2 are obtained by appropriately changing the die.

  In Example 2, although the side-by-side cross-sectional shape has two types of 1.8, 2.3, and 14 filaments and 10 filaments, respectively, one step is taken in Example 1 in terms of fabric surface quality and stretch back. An excellent one was given.

  In Example 3, the side-by-side cross-sectional shape has two types of irregularities of 2.3 and 2.1, and 14 filaments and 10 filaments, respectively. However, one step is taken in Example 1 in terms of fabric surface quality and stretch back properties. An excellent one was given.

  In Example 4, the discharge amount and the mouthpiece were changed, and the side-by-side cross-sectional shape was changed to 2.3, 1.8, and 1.4, each of 4 types of 33 dtex-12 filament polyester composite fibers and However, in terms of stretch-back property, a material excellent in the fabric surface quality was obtained although it was a step away from Example 1.

  In Example 5, both of the polymer components were 3GT, but in terms of fabric surface quality and stretch back property, a good one was obtained although it was a step away from Example 1.

In Example 6, the polymer component is PET having intrinsic viscosities of 0.85 and 0.51, respectively, and the cross-sectional shape irregularity is 2.5, 2.0, and 1.5, each of 16 types of 16 filaments and 56 dtex. A polyester composite fiber of −48 filaments was obtained, but in terms of fabric surface quality and stretch-back properties, a pass level that was one step away from Example 1 was obtained.
In Example 7, the cross-sectional shape irregularity is 16 filaments each of three types of 2.5, 2.0, and 1.5. However, in terms of fabric surface quality and stretch back property, An excellent product was obtained.

  In Example 8, the degree of profile variation in the cross-sectional shape was set to 4 filaments of three types of 2.0, 1.9, and 1.8, respectively, but in terms of fabric surface quality and stretch back properties, one step was given to Example 1. However, a good one was obtained.

  In Example 9, two types of cross-sectional shapes of 3.0 and 1.0, each of 12 filaments, were used. However, although the fabric surface quality and stretch-back properties were one step away from Example 1, they were good. Things were obtained.

  In Example 10, the intrinsic viscosity of 3GT was set to 1.82 and the intrinsic viscosity of PET was set to 0.51, but in terms of the fabric surface quality and stretch back properties, the same excellent results as in Example 1 were obtained. .

  In Example 11, the intrinsic viscosity of 3GT was 1.02 and the intrinsic viscosity of PET was 0.51, but the shrinkage difference between the high-shrinkage polyester and the low-shrinkage polyester component was small compared to Example 1, and the fabric surface Although the quality and stretch-back properties were transferred to Example 1, good ones were obtained.

  On the other hand, in Comparative Example 1, the polyester composite fiber is composed of a single single yarn having a cross-sectional shape irregularity of 1.8. However, since the dispersion of the irregularity is small, the crimp phase shifts. It was small and low in bulk height, and the surface quality of the fabric did not greatly exceed Example 1.

  In Comparative Example 2, the cross-sectional shape irregularity was 1.8, 1.9, 14 filaments and 10 filaments respectively, but the stretch back property was very excellent as in Example 1. However, since the dispersion of the degree of deformation was small, the crimp phase shift was small, the bulkiness was low, and the surface quality of the fabric did not greatly exceed Example 1.

  In Comparative Example 3, referring to Example 10 of Japanese Patent Application Laid-Open No. 2004-323991, the polymer component was 3GT having intrinsic viscosities of 1.90 and 1.20, respectively, and the cross-sectional shape was 1.1 and the cross-sectional area was 1.1. Although it was set as the polyester composite fiber comprised from the single thread | yarn whose ratio will be 1.2, although it is the very same thing as Example 1 in stretch back property, in the surface quality of a cloth, it is a deformity degree Therefore, the crimp phase shift was small and the bulk height was low, which was significantly inferior to Example 1.

  In Comparative Example 4, the shape of the cross-sectional shape was set to 12 filaments each of two types of 4.0 and 1.0. However, because of the two groups having extremely different shapes, the phase of crimping is different. As a result, the bulk height did not increase, and the fabric surface quality was significantly inferior to that of Example 1.

  In Comparative Example 5, although the polymer component was 3GT having an intrinsic viscosity of 1.02 and PET having an intrinsic viscosity of 0.78, the difference in shrinkage between the high-shrinkage polyester and the low-shrinkage polyester component was small compared to Example 1. The expansion / contraction elongation ratio was lowered, and the stretchability was reduced to Example 1. Moreover, since the shrinkage difference of the polyester component was small in the fabric surface quality, the bulk height was low, which was not much higher than Example 1.

Example 12, Comparative Examples 6-7
Bulky polyester composite fibers were obtained by the two-step method under the production conditions shown in Table 3. In addition, the composite fiber of the irregularity degree of Table 3 is obtained by changing a nozzle | cap | die suitably.

  In Example 12, the polymer component was PET having intrinsic viscosities of 0.85 and 0.51, respectively. These are melted separately and allowed to flow into the die at a spinning temperature of 280 ° C., so that three different types of single yarns with cross-section irregularities of 2.5, 2.0, and 1.5 become 16 filaments each. It was. This was taken up at a spinning speed of 1450 m / min to obtain an undrawn yarn of 145 dtex-24 filaments. Using the drawing machine shown in FIG. 10, the undrawn yarn is supplied while being drawn 2.6 times between a supply roller (hereinafter referred to as supply R) 20 and a take-off roller (DR) 22 heated to 90 ° C. A heat treatment was performed by running on a hot plate at 150 ° C. provided between the roller and the take-up roller, and wound at 800 m / min to obtain a 56 dtex-24 filament polyester composite fiber. The property evaluation results of the polyester conjugate fiber are as shown in Table 3, and in terms of fabric surface quality and stretch-back property, the one with a pass level of one step in Example 1 was obtained.

  In Comparative Example 6, Example 1 of JP-A-01-266220 was referred to. Polymer component A has an intrinsic viscosity of 0.68, polymer component B has a dicarboxylic acid component having 2.3 mol% 5-sodium sulfoisophthalic acid, and adipic acid 4.8 mol% as a copolymer component. Using the modified PET of 0.57, the single yarn group is (1) a single yarn having a composite ratio of the A component and the B component of 50:50 and a deformity of 1.0. (2) A single yarn comprising only the A component. Yarn (the degree of irregularity is 0) (3) A polyester composite fiber consisting of three groups of single yarns (only the degree of irregularity is 0) consisting of component B was obtained. The polyester composite fiber property evaluation results are as shown in Table 3. Both the stretch back property and the fabric surface quality were significantly inferior to those of Example 1.

  In Comparative Example 7, the polymer component is PET having intrinsic viscosities of 0.78 and 0.51, respectively, and a 56 dtex-12 filament composed of a single single yarn having a cross-sectional shape irregularity of 1.0. Although it was set as the polyester composite fiber, since the difference in shrinkage between the high-viscosity polyester and the low-viscosity polyester was small, the stretch / elongation rate was low, and the stretch-back property did not greatly exceed Example 1. Further, in the fabric surface quality, since the dispersion of the degree of deformation was small, the crimp phase shift was small and the bulk height was low, which was significantly inferior to Example 1.

Example 13, Comparative Example 8
Bulky polyester composite fibers were obtained by the two-step method under the production conditions as shown in Table 4. In addition, the composite fiber of the irregularity degree of Table 4 is obtained by changing a nozzle | cap | die suitably.

  In Example 13, the polymer component was 3GT with an intrinsic viscosity of 1.43 and PET of 0.51. These are melted separately and allowed to flow into the die at a spinning temperature of 270 ° C., so that three different single yarns with cross-sectional irregularities of 2.5, 2.1, and 1.8 become 8 filaments each. It was. This was taken up at a spinning speed of 1400 m / min to obtain a 156 dtex-24 filament side-side composite structure undrawn yarn. Further, after aging the undrawn yarn at an environmental temperature of 25 ° C. × 2 days, using the drawing machine shown in FIG. 11, the draw ratio between the first HR 25 temperature of 70 ° C., the second HR 26 temperature of 35 ° C., the first HR and the second HR is 3.2 times. At a third HR27 temperature of 170 ° C., and a relaxation rate of 13% between the second HR and the third HR, stretched 1.02 times between the third HR and the take-up roller (hereinafter referred to as DR) 28, and a 56 dtex-24 filament A polyester composite fiber was obtained. The characteristic evaluation results of the polyester composite fiber are as shown in Table 4, and the fabric surface quality and the stretch back property were very excellent as in Example 1.

  In Comparative Example 8, Example 1 of JP-A-2002-61031 was referred to. The polymer component was 3GT having an intrinsic viscosity of 1.38 and 3GT having an intrinsic viscosity of 0.65, and a polyester composite fiber having 84 dtex-36 filaments composed of a single single yarn having an irregularity of 1.0 was obtained. The results of property evaluation of the polyester composite fiber are as shown in Table 4. Although the stretch back property is as excellent as that of Example 1, the dispersion of the deformity is small in the fabric surface quality. The shrinkage of the contraction phase was small and the bulk height was low, which was not much greater than that of Example 1.

The figure for demonstrating the definition of the irregularity degree of the single yarn cross-sectional shape in this invention is shown. An example of the single yarn group which comprises the polyester composite fiber in this invention is shown. An example of the cross-sectional shape of the single yarn of the polyester composite fiber in this invention is shown. An example of the longitudinal cross-sectional view of the spinneret preferably used in order to manufacture the polyester composite fiber of this invention is shown. The figure for demonstrating the measuring method of expansion-contraction elongation rate is shown. 1 shows a perspective view of an apparatus for measuring bulk height. The sketch which shows the measuring method of bulk height is shown. The schematic of the direct spinning | stretching extending | stretching apparatus used in the Example of this invention is shown. The cross-sectional shape of the single yarn group which comprises the polyester composite fiber obtained by this invention (Example 1) is shown. The schematic of the extending | stretching apparatus used in the Example of this invention is shown. The schematic of the extending | stretching apparatus used in the Example of this invention is shown.

Explanation of symbols

1: Sample stage 2: PET film 3: Metal fitting with pointer 4: Load 5: Scale 6: Notch 7: Fuse 8: Base 9: Yarn cooling blower 10: Oil supply device 11: Entangling device 12: First hot Roll 13: Second hot roll 14: Entangling device 15: Third godet roller 16: Fourth godet roller 17: Contact roller 18: Package 19: Undrawn yarn 20: Supply roller 21: Hot plate 22: Take-up roller 23: Undrawn yarn 24: supply roller 25: first hot roller 26: second hot roller 27: third hot roller 28: take-up roller 29: drawn yarn

Claims (5)

A bulky polyester composite fiber, which is a side-by-side type composite fiber composed of two types of intrinsic viscosity polyesters, which is composed of two or more groups of single yarn groups having different degrees of deformity, and satisfies the following requirements.
(A) Expansion / contraction elongation S 20 ≦ S ≦ 150 (%)
(B) Bulk height B 71 × 10 ⁻³ ≦ B ≦ 200 × 10 ⁻³ (m ³ / kg)
However, the deformity is calculated by the following equation.
Deformation degree of each single yarn = major axis length / minor axis length Major axis length: diameter of circumscribed circle of the cross section of each single yarn Short axis length: between the two points of intersection of the cross-section composite interface of each single yarn and the fiber surface distance The bulky polyester composite fiber according to claim 1, wherein the dispersion V _{D of the} degree of deformation of the single yarn satisfies the following requirement (C).
(C) 0.4 <V _D <150
However, the variance V _{D of the} irregularity is calculated by Equation 1.

  3. The bulky polyester composite fiber according to claim 1, wherein at least one component constituting the single yarn is polytrimethylene terephthalate.   A fiber product comprising at least a part of the bulky polyester conjugate fiber according to any one of claims 1 to 3.   A knit product comprising at least a part of the bulky polyester conjugate fiber according to any one of claims 1 to 3.

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