JP2013209785A - Latent crimpable polyester conjugated fiber yarn - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a latent crimpable polyester conjugated fiber yarn having extremely soft touch feeling as well as excellent stretchability and surface smoothness when made into a woven or knitted fabric, and a woven or knitted fabric comprising the conjugated fiber yarn.SOLUTION: There is provided a latent crimpable polyester conjugated fiber yarn that is provided by converging latent crimpable polyester conjugated fibers which are obtained by joining a highly heat-shrinkable polyester (A) and a lowly heat-shrinkable polyester (B) with each other in a side-by-side manner or in an eccentric core-sheath manner. The highly heat-shrinkable polyester (A) includes 4 to 10 mol% of a neopentyl glycol component as a copolymerization component. The fiber yarn has actual crimps in a three-dimensional spiral shape. An actual crimp rate (C0(%)) of the fiber yarn satisfies an expression (I): 0<C0(%)≤5, and a latent crimp rate (C100(%)) thereof satisfies an expression (II): 20<C100(%)≤40.

Description

  The present invention relates to a latent crimpable polyester composite fiber yarn, and more particularly to a latent crimpable polyester composite fiber yarn that gives excellent stretch properties, surface smoothness and texture to a fabric using the yarn, and The present invention relates to a woven or knitted fabric made of composite fiber yarn.

  A fiber made of a polyester resin represented by polyethylene terephthalate (hereinafter abbreviated as PET) has excellent mechanical properties and chemical properties, and is used in a wide range of applications. One of the uses is a woven or knitted fabric having stretch properties.

  Many latent crimped polyester composite fibers in which polyester resins having different heat shrinkage properties are joined in a side-by-side type or an eccentric core-sheath type have been proposed as fibers for imparting stretch properties to a woven or knitted fabric. The latent crimped polyester composite fiber can impart stretchability to the woven or knitted fabric by applying heat treatment after weaving and knitting to develop crimp.

  In addition to the above stretch properties, two types of PET having different intrinsic viscosities are bonded to the side-by-side type as a soft texture with a feeling of swelling to the woven or knitted fabric, and the bonding surface of the two types of PET in the fiber cross section is Composite fibers and multifilaments that are curved into a specific shape are known (see, for example, Patent Documents 1 and 2).

  However, when the above multifilament is used alone in a woven or knitted fabric, there is a problem that the form of crimp that appears is large, the surface smoothness is poor, and the embossing defect occurs.

  As a method of solving the above problem, there is a method of reducing the single yarn fineness of the multifilament, but if the single yarn fineness is reduced, the surface smoothness is improved, but the crimping performance is remarkably lowered, and sufficient stretchability is obtained. There was a problem that it was not possible.

  Also known is a composite fiber of copolyester and PET obtained by copolymerizing 5-30 mol% of a neopentyl glycol ethylene oxide adduct (hereinafter abbreviated as NPGEO adduct) as a glycol component (see, for example, Patent Document 3). ). According to Patent Document 3, it is said that the conjugate fiber exhibits an excellent latent crimp expression even under restraint.

  However, since the copolyester is poor in crystallinity due to the molecular structure due to addition of NPGEO, the composite fiber made of the copolyester has a high shrinkage rate and is poor in thermal stability, and the woven fabric obtained from the composite fiber. The knitted fabric has a problem that the texture becomes harder by heat treatment.

  As described above, when a woven or knitted fabric is used, a latent crimpable polyester fiber yarn capable of simultaneously obtaining excellent stretch properties, surface smoothness, and soft texture has not yet been obtained.

Japanese Patent Laid-Open No. 11-241229 JP 2000-212838 A JP-A-9-296325

  The present invention solves the various problems in the prior art, and provides a very soft texture when a woven or knitted fabric is obtained, and a latent crimpable polyester composite fiber yarn that provides excellent stretchability and surface smoothness. It is a technical object to provide a woven or knitted fabric composed of a strip and the composite fiber yarn.

  The inventors of the present invention have arrived at the present invention as a result of intensive studies to solve the above problems. That is, the gist of the present invention is as follows (1) to (3).

(1) A yarn formed by converging latent crimpable polyester composite fibers obtained by bonding a high heat-shrinkable polyester (A) and a low heat-shrinkable polyester (B) to a side-by-side type or an eccentric core-sheath type, The high heat-shrinkable polyester (A) contains 4 to 10 mol% of a neopentyl glycol component as a copolymer component, the yarn has a three-dimensional spiral-like crimp, and the yarn has an apparent crimp rate (C0 ( %)) Satisfies the formula (I), and the latent crimp rate (C100 (%)) satisfies the formula (II).
0 <C0 (%) ≦ 5 (I)
20 ≦ C100 (%) ≦ 40 (II)
C0 (%) = [(L0−L1) / L0] × 100
C100 (%) = [(A0−A1) / A0] × 100
L1: Knot length while applying a tension of 90.91 × 10 ⁻³ cN / dtex to the yarn, applying a load of 1.67 × 10 ⁻⁴ cN / dtex to the knot, and standing for 30 minutes L0: After the L1 measurement, the length A1: when the load is changed from 1.67 × 10 ⁻⁴ cN / dtex to 90.91 × 10 ⁻³ cN / dtex, the yarn has 90.91 × 10 ⁻³ cN / dtex. Remove the wrinkle while applying tension, and after boiling water for 30 minutes while applying a load of 1.67 × 10 ⁻⁴ cN / dtex, apply a load of 1.76 × 10 ⁻³ cN / dtex and leave it for 30 minutes. Later saddle length A0: The saddle length when the load is changed from 1.76 × 10 ⁻³ cN / dtex to 4.4 × 10 ⁻² cN / dtex after A1 measurement.

(2) The high heat-shrinkable polyester (A) comprises only a terephthalic acid component, an ethylene glycol component and a neopentyl glycol component, and the low heat-shrinkable polyester (B) is polyethylene terephthalate (1) ) Latent crimped polyester composite fiber yarn.
(3) A woven or knitted fabric comprising the latently crimpable polyester composite fiber yarn described in (1) or (2) above.

  According to the latent crimpable polyester composite fiber yarn of the present invention, a woven or knitted fabric using the yarn has an extremely soft texture and is excellent in stretchability and surface smoothness.

It is a cross-sectional schematic diagram of this composite fiber showing the side-by-side type | mold which is one embodiment of the composite shape of the composite fiber which comprises the thread | yarn of this invention. It is a cross-sectional schematic diagram of this composite fiber showing the eccentric core-sheath type | mold which is one embodiment of the composite shape of the composite fiber which comprises the thread | yarn of this invention.

  The present invention will be described in detail below.

  The latent crimpable polyester composite fiber yarn of the present invention is a latent crimpable polyester composite fiber in which a high heat-shrinkable polyester (A) and a low heat-shrinkable polyester (B) are joined in a side-by-side type or an eccentric core-sheath type. It is a yarn that converges.

  In the present invention, the high heat-shrinkable polyester (A) needs to contain a neopentyl glycol (hereinafter abbreviated as NPG) component as a copolymerization component. Especially, it is preferable that the said high heat-shrinkable polyester (A) consists only of a terephthalic acid component, an ethylene glycol component, and an NPG component.

  When the high heat-shrinkable polyester (A) contains the NPG component as a copolymerization component, the heat-shrinkability of the portion occupied by the high heat-shrinkable polyester (A) in the composite fiber is reduced by the low heat-shrinkable polyester (B ) Is significantly higher than the heat shrinkability of the portion occupied. As a result, the composite fiber and the yarn formed by converging the composite fiber have a three-dimensional spiral-shaped apparent crimp, and heat treatment is performed on the woven or knitted fabric using the yarn, for example, by heat treatment after yarn production. By doing so, it becomes excellent in the latent crimp expression property in which a three-dimensional spiral latent crimp is developed. Here, the three-dimensional spiral shape means a three-dimensional form that is a coil (spiral) spring shape.

  In the present invention, the composite fiber yarn containing the high heat-shrinkable polyester (A) copolymerized with NPG gives a soft texture to the woven or knitted fabric using the composite fiber yarn. Furthermore, when the high heat-shrinkable polyester (A) is a terpolymer comprising only a terephthalic acid component, an ethylene glycol component and an NPG component, the texture of the woven or knitted fabric using the resulting composite fiber yarn is particularly excellent. Since it becomes a thing, it is preferable.

  The high heat-shrinkable polyester (A) copolymerized with NPG gives the composite fiber yarn a spiral crimp superior to, for example, a polyester copolymerized with isophthalic acid (hereinafter abbreviated as IPA). The reason for this is not clear, but the high heat-shrinkable polyester (A) has a large steric hindrance due to two methyl groups in the NPG unit, and is used when fiberizing a composite fiber containing the high heat-shrinkable polyester (A). Since the residual stress becomes very high, it is presumed that an excellent spiral crimp is developed by the heat treatment.

  On the other hand, the crystallinity of the highly heat-shrinkable polyester (A) copolymerized with the NPG component is maintained to some extent as compared with, for example, polyester copolymerized with IPA or NPGEO adduct. The reason for this is also not clear, but the polyester copolymerized with IPA is copolymerized as a polybasic acid component, so the high terephthalic acid component that is also a polybasic acid component in the polyester has high rigidity. Presumed to be damaged. On the other hand, in the high heat shrinkable polyester (A) copolymerized with NPG according to the present invention, the NPG is copolymerized as a polyhydric alcohol component, so that terephthalate which is a polybasic acid component in the high heat shrinkable polyester (A) It is presumed that the high rigidity of the acid component is not impaired. For polyesters copolymerized with NPGEO adducts, NPGEO adducts have ethylene oxide in the molecule, and thus have higher crystallinity than high heat-shrinkable polyesters (A) copolymerized with NPG components that do not have ethylene oxide. Presumed to be reduced.

  In the present invention, the high heat-shrinkable polyester (A) needs to contain 4 to 10 mol% of an NPG component as a copolymerization component, and preferably 6 to 10 mol%.

  When the amount of copolymerization of the NPG component with respect to the whole high heat-shrinkable polyester (A) is less than 4 mol%, when the resulting composite fiber is made into a woven or knitted fabric, the woven or knitted fabric is soft. A smooth texture cannot be obtained. Further, when the copolymerization amount exceeds 10 mol%, when only a yarn formed by convergence of the obtained composite fiber is used to form a woven or knitted fabric, the woven or knitted fabric has poor surface smoothness, and further has a wrinkle-prone defect. Will occur. It is preferable that the amount of copolymerization is 6 to 10 mol% because the stretchability of the resulting woven or knitted fabric becomes particularly excellent.

  In the present invention, the intrinsic viscosity of the high heat-shrinkable polyester (A) is preferably 0.58 to 0.80. When the intrinsic viscosity of the high heat-shrinkable polyester (A) is less than 0.58, it is difficult to obtain a composite fiber yarn having sufficient spiral crimp expression. On the other hand, when the intrinsic viscosity exceeds 0.80, spinning operability is likely to be remarkably deteriorated, for example, kneeling occurs during spinning and yarn breakage occurs frequently. As will be described later, when PET, which is one of the preferred embodiments as the low heat-shrinkable polyester (B), is used, the intrinsic viscosity of the PET usually used is 0.58 to 0.66. The intrinsic viscosity of the high heat shrinkable polyester (A) is preferably 0.70 to 0.80.

  70-80 degreeC is preferable and, as for the glass transition point (Tg) of the high heat-shrinkable polyester (A) in this invention, 75-80 degreeC is more preferable. When the glass transition point is less than 70 ° C., the crystallinity of the high heat-shrinkable polyester (A) is low, and the resulting composite fiber yarn tends to be inferior in thermal stability. Due to this, the texture tends to be hard. Furthermore, as a result of the low crystallinity of the high heat-shrinkable polyester (A), when the woven or knitted fabric is heat-treated, the composite fiber yarns constituting the woven or knitted fabric are easily fused to each other. Is likely to get worse. Moreover, since the glass transition point of ordinary PET is about 78 ° C., it does not exceed 80 ° C. unless a component that increases the rigidity of polyester resin such as naphthalenedicarboxylic acid is copolymerized, but Tg is 80 ° C. It is not preferable to copolymerize a component that becomes more rigid as it exceeds, because it tends to inhibit the expression of spiral crimp.

  The latent crimpable polyester composite fiber yarn of the present invention contains, for example, an IPA or NPGEO adduct as a copolymerization component, because the high heat-shrinkable polyester (A), which is a highly shrinkable component, contains an NPG component as a copolymerization component. The crystallinity is higher than that. As a result, Tg becomes relatively high, so that the composite fiber yarn is excellent in thermal stability. Furthermore, the copolymer composition and the ratio of the high heat-shrinkable polyester (A) can be adjusted so that the Tg of the high heat-shrinkable polyester (A) satisfies the above range, thereby obtaining a composite fiber yarn. It is possible to increase the temperature of the spinning and drawing heat treatment, and the resulting composite fiber yarn is hard to be hardened even by heat treatment for developing latent crimps.

  In the present invention, the low heat-shrinkable polyester (B) is not particularly limited as long as it has ethylene terephthalate as a main component, but it is necessary that the heat-shrinkable property is lower than that of the high heat-shrinkable polyester (A). Therefore, it is preferable to use PET in which the repeating unit of the ethylene terephthalate component is 95% or more.

  In the present invention, the intrinsic viscosity of the low heat shrinkable polyester (B) is preferably 0.44 to 0.66.

  If the intrinsic viscosity of the low heat-shrinkable polyester (B) is less than 0.44, the spinning operability is likely to be deteriorated, such as the occurrence of kneeling and frequent yarn breakage during spinning, and the intrinsic viscosity is more than 0.66. It is difficult to obtain a composite fiber yarn having a spiral crimp expression. Moreover, when PET which is one of the preferred embodiments as the low heat shrinkable polyester (B) is used as described above, the intrinsic viscosity of the low heat shrinkable polyester (B) is preferably 0.58 to 0.66. .

  Furthermore, in the present invention, the intrinsic viscosity difference between the high heat-shrinkable polyester (A) and the low heat-shrinkable polyester (B) is not particularly limited, but is preferably 0 to 0.25.

  When the above intrinsic viscosity difference exceeds 0.25, when the composite flow of each polyester is discharged from the spinneret, the yarn bends excessively, and the yarn adheres to the spinneret and is likely to be cut and stable. Therefore, it is difficult to perform spinning.

  In the present invention, the high heat-shrinkable polyester (A) and the low heat-shrinkable polyester (B) may contain other copolymerization components as long as the effects of the present invention are not impaired.

  For example, as polybasic acids, in addition to terephthalic acid, isophthalic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, hydrogenated dimer acid and other aliphatic dicarboxylic acids, 1,4-cyclohexane Examples thereof include alicyclic dicarboxylic acids such as dicarboxylic acids, and aromatic dicarboxylic acids such as 5-sodium sulfoisophthalic acid, 2,6-naphthalenedicarboxylic acid, orthophthalic acid, and trimellitic acid.

  Further, as polyhydric alcohols other than NPG and ethylene glycol, diethylene glycol, triethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, dipropylene glycol , Polyethylene glycol, polypropylene glycol, polytetramethylene glycol, 2-ethyl-2-butylpropanediol, 2-methyl-1,3-propanediol, 1,4-cyclohexanedimethanol, 2,2-bis (4-hydroxy Phenyl) propane alkylene oxide adduct, tricyclodecane glycols, trimethylolethane, trimethylolpropane and the like.

  The high heat-shrinkable polyester (A) and the low heat-shrinkable polyester (B) are matte agents, antioxidants, ultraviolet absorbers, pigments, flame retardants, antibacterial agents, and conductivity-imparting agents as long as the essential properties are not impaired. Etc., and may contain a small amount of other components.

  In the present invention, the high heat-shrinkable polyester (A) and the low heat-shrinkable polyester (B) need to be joined to the side-by-side type or the eccentric core-sheath type along the longitudinal direction of the composite fiber.

  1A and 1B are schematic cross-sectional views of a composite fiber representing a side-by-side type which is an embodiment of the composite shape of the composite fiber constituting the yarn of the present invention. As a side-by-side type in the present invention, the joint surfaces of the two types of polyester shown in FIG. 1A are linear and substantially equally joined, or the joint surfaces shown in FIG. What is joined is mentioned.

  FIG. 2 is a schematic cross-sectional view of the composite fiber representing an eccentric core-sheath type which is an embodiment of the composite shape of the composite fiber constituting the yarn of the present invention. As an eccentric core-sheath type in the present invention, one in which one polyester shown in FIG. 2 is a sheath and the other polyester is a core, and the centers of the core and the sheath do not coincide with each other. In the present invention, it is preferable that the sheath part is a high heat shrinkable polyester (A) and the core part is a low heat shrinkable polyester (B).

  In the present invention, the mass ratio (A / B) of the high heat-shrinkable polyester (A) and the low heat-shrinkable polyester (B) is preferably in the range of 40/60 to 60/40. Outside this range, it is difficult for the resulting composite fiber yarn to exhibit sufficient crimping performance.

  In addition, the fineness of the composite fiber constituting the composite fiber yarn of the present invention is not particularly limited, but is preferably 0.9 dtex or more and 2 dtex or less. When the fineness is less than 0.9 dtex, the obtained composite fiber yarn is not only insufficient in the expression of crimp performance, and it is difficult to obtain a woven or knitted fabric having sufficient stretch performance, The composite fiber tends to adhere to the spinneret during spinning, and it is difficult to perform stable spinning. On the other hand, if the fineness exceeds 2 dtex, the resulting woven or knitted fabric made of the composite fiber yarn is likely to be difficult to obtain good softness.

  The latent crimpable polyester composite fiber yarn of the present invention needs to have a three-dimensional spiral-like manifest crimp.

  As described above, the three-dimensional spiral-shaped actual crimp is a crimp having a three-dimensional form that is a coil (spiral) spring shape, and in the present invention, the composite constituting the yarn of the present invention. The fiber has the actual crimp and also has the actual crimp as a yarn formed by converging the composite fiber. The actual crimp is mainly caused by a process such as spinning or drawing due to a difference in heat shrinkage between two kinds of polyesters constituting the composite fiber.

  The actual crimp rate (C0) in the present invention needs to satisfy 0 <C0 (%) ≦ 5, and preferably 0.5 ≦ C0 (%) ≦ 5.

Here, the actual crimp rate (C0) can be expressed by the following equation.
C0 (%) = [(L0−L1) / L0] × 100
L1: Knot length while applying a tension of 90.91 × 10 ⁻³ cN / dtex to the yarn, applying a load of 1.67 × 10 ⁻⁴ cN / dtex to the knot, and standing for 30 minutes L0: After L1 measurement, the length when the load is changed from 1.67 × 10 ⁻⁴ cN / dtex to 90.91 × 10 ⁻³ cN / dtex

  When the actual crimp rate exceeds 5%, when only the resulting composite fiber yarn is used to form a woven or knitted fabric, the woven or knitted fabric has a poor surface smoothness and a wrinkle standing defect. Further, when the actual crimp rate is less than 0.5%, the resulting woven or knitted fabric made of the composite fiber yarn tends to have poor stretchability.

  In addition, the latent crimp rate (C100) in the present invention needs to satisfy 20 ≦ C100 (%) ≦ 40, and preferably 30 ≦ C100 (%) ≦ 40.

Here, the latent crimp rate (C100) can be expressed by the following equation.
C100 (%) = [(A0−A1) / A0] × 100
A1: The yarn is taken off while applying a tension of 90.91 × 10 ⁻³ cN / dtex to the yarn, and 1.67 × 10 ⁻⁴ cN / dtex is applied to the heel for 1.30 minutes after boiling water treatment. After applying a load of 10 ⁻³ cN / dtex and leaving it to stand for 30 minutes, after measuring A0: A0, the load is changed from 1.76 × 10 ⁻³ cN / dtex to 4.4 × 10 ⁻² cN / dtex. Chief

  By setting the latent crimp rate to 20% or more, regardless of the combination with other materials and the selection of processing conditions, the woven or knitted fabric made of composite fiber yarns can exhibit excellent stretch performance. It becomes. When the latent crimp rate is less than 20%, the woven or knitted fabric cannot obtain sufficient stretch performance. On the other hand, when the actual crimping rate exceeds 40%, the surface smoothness is poor and a wrinkle standing defect occurs when used alone in a woven fabric. By setting the latent crimp rate to 30 to 40%, the obtained woven or knitted fabric is preferable because excellent stretchability and soft texture can be easily obtained.

  The apparent crimp rate and the latent crimp rate are set appropriately depending on the copolymer component and intrinsic viscosity of the high heat-shrinkable polyester (A) and the low heat-shrinkable polyester (B), and the fineness of the composite fiber constituting the composite fiber yarn. It can be adjusted by making things.

  Next, an example is given and demonstrated about the manufacturing method of the composite fiber yarn of this invention.

  The composite fiber yarn of the present invention can be produced by a normal composite melt spinning apparatus. First, on the back surface of the spinneret, the high heat-shrinkable polyester (A) and the low heat-shrinkable polyester (B) are joined so as to be a side-by-side type, and the composite fiber is spun from the same spinneret. In this case, the spinning temperature is appropriately selected depending on the intrinsic viscosity of both polyesters, but is usually preferably in the range of 280 ° C to 310 ° C.

  The spun composite fiber is cooled and solidified, and then applied with a spinning oil agent to be converged into a composite fiber bundle, taken up at a speed of 1000 m to 4000 m / min, once taken up, and subjected to heat drawing by a drawing machine, Alternatively, the composite fiber yarn of the present invention can be obtained by continuously drawing the taken composite fiber bundle without taking it off.

  Although the draw ratio in the said manufacturing method is suitably selected by the residual elongation of the composite fiber at the time of taking, it is preferable to select so that the residual elongation after extending | stretching may be in the range of 15 to 40%. If the residual elongation is higher than this range, sufficient crimping performance will not be exhibited, and if the residual elongation is lower than this range, the composite fiber is likely to be broken during stretching, which is likely to cause operational problems. Absent.

  And when using the composite fiber yarn of the present invention as a woven or knitted fabric, it can be used as warp or weft as it is, but it may be mixed with other yarns. Moreover, false twist processing may be given and false twist mixing fiber may be sufficient. Moreover, a real twist may be provided, a real twist mixed fiber, or a combination of these may be used.

  Since the latent crimp of the composite fiber yarn of the present invention is expressed by crimping by heat treatment, considering the workability such as process passability, the composite fiber yarn of the present invention is knitted or woven. It is preferable to make a woven or knitted fabric by using a boiling water treatment to develop latent crimps. In particular, it is preferable to perform boiling water treatment in the dyeing step to develop it.

  Next, a woven or knitted fabric using the latent crimpable polyester composite fiber yarn of the present invention (hereinafter sometimes abbreviated as the woven or knitted fabric of the present invention) will be described.

  The woven or knitted fabric of the present invention comprises the above-described composite fiber yarn of the present invention.

  In order to further enhance the effects of the invention, it is preferable that the composite fiber yarn of the present invention is used in an amount of 40% by mass or more based on the total constituent yarn of the woven or knitted fabric. Further, according to the composite fiber yarn of the present invention, even when the woven or knitted fabric of the present invention is made using only the composite fiber yarn, the woven or knitted fabric has good surface smoothness and little occurrence of wrinkle-prone defects. .

  The structure of the woven or knitted fabric of the present invention is not particularly limited. The woven or knitted fabric of the present invention may be woven or knitted by a known method using the latent crimpable polyester composite fiber yarn of the present invention, and may be subjected to scouring, relaxation, dyeing or the like as necessary. For example, in any of the steps of scouring, relaxing, and dyeing, the latent crimps of the yarn can be manifested, and as a result, the knitted or knitted fabric can be provided with stretch performance.

  As described above, in the latent crimpable polyester composite fiber yarn of the present application, the high heat-shrinkable polyester (A) contains an NPG component, the content of the NPG component is set to a predetermined value, and the manifested crimp of the yarn By making the ratio and the latent crimp ratio within a predetermined range, it becomes possible to simultaneously give an extremely soft texture and excellent stretchability and surface smoothness to the woven or knitted fabric obtained from the yarn.

  Hereinafter, the present invention will be described more specifically with reference to examples. In the examples, measurement and evaluation were performed as follows.

(1) Intrinsic viscosity (V (A), V (B))
The polyester was dissolved in a 1: 1 mixed solvent of phenol and tetrachloroethane, and measured at 20 ° C. using an Ubbelohde viscometer.

(2) Measurement of glass transition point (Tg) and melting point (Tm) of high heat-shrinkable polyester (A) Using a differential scanning calorimeter SSC5200 manufactured by Seiko Denshi Kogyo Co., Ltd., it was measured at a temperature rising rate of 10 ° C / min.

(3) Composite fiber fineness The value obtained by dividing the correct fineness of the composite fiber yarn measured by the JIS L 1013 positive fineness A method by the number of filaments was defined as the composite fiber fineness.

(4) High elongation JIS L 1013 It measured by tensile strength and elongation rate.

(5) Latent crimp rate and apparent crimp rate Measurement and calculation were performed by the method described above.

(6) Stretchability, surface smoothness (texture standing), and softness Using the obtained composite fiber yarn, weaving into a plain weave structure, and sensory evaluation by 10 panelists was performed. Each sample has a high stretchability, good surface smoothness (no wrinkles) and excellent softness, and was evaluated on a scale of 1 to 10 on a 10-point scale. Each evaluation scored 7 points or more).

Example 1
As the high heat-shrinkable polyester (A), a polyester having an intrinsic viscosity of 0.73 mainly composed of ethylene terephthalate units and copolymerized with 6 mol% of NPG is used, and as the low heat-shrinkable polyester (B), an intrinsic viscosity consisting essentially of PET. 0.64 polyester was used. The high heat-shrinkable polyester (A) and the low heat-shrinkable polyester (B) are supplied in equal amounts to a compound spinning melt extruder, melted at a spinning temperature of 295 ° C., and both polyesters on the back of a spinneret having 48 spinning holes. After the composite fiber spun by spinning into the side-by-side mold shown in FIG. 1 (A) is cooled and solidified, the composite fiber is converged into a composite fiber bundle while applying an oil agent, and the surface speed is 3000 m / The sample was taken off by a take-up machine through a minute take-up roller. Next, the drawn composite fiber bundle is supplied to a drawing machine, and is drawn 1.60 times through a roller having a surface temperature of 85 ° C. and a hot plate having a temperature of 170 ° C., and is a 56 dtex / 48 filament latent crimpable polyester. A composite fiber yarn was obtained. In addition, the measurement of the said composite fiber fineness, the said strong elongation, the said actual crimp rate, and the latent crimp rate was performed using what was sampled from the said latent crimp polyester composite fiber yarn.

  Weaving a plain weave fabric with warp density of 110 / 2.54 cm and weft density of 80 / 2.54 cm using the latently crimped polyester composite fiber yarn obtained as above for warp and weft, and scouring Thereafter, it was treated in boiling water at 100 ° C. for 30 minutes and then air-dried to obtain a woven fabric. About the obtained textile fabric, the said stretch property, surface smoothness (texture standing), and soft evaluation were performed.

Examples 2 and 3, Comparative Examples 3, 5 and 6
A composite fiber yarn and woven fabric were obtained in the same manner as in Example 1 except that the copolymerization amount of NPG, the intrinsic viscosity of the high heat-shrinkable polyester (A) and the resin properties were changed as shown in Table 1.

Example 4
A composite fiber yarn and woven fabric were obtained in the same manner as in Example 1 except that the intrinsic viscosity of the low heat-shrinkable polyester (B) was changed as shown in Table 1.

Example 5, Comparative Examples 1 and 2
A composite fiber yarn and woven fabric were obtained in the same manner as in Example 1 except that the copolymer composition and resin properties of the high heat-shrinkable polyester (A) were changed as shown in Table 1.

Comparative Example 4
A composite fiber yarn and woven fabric were obtained in the same manner as in Example 1 except that the copolymerization amount and resin properties of the high heat-shrinkable polyester (A) were changed as shown in Table 1.

  Table 1 shows the evaluation results of the composite fiber yarns and woven fabrics obtained in Examples 1 to 5 and Comparative Examples 1 to 6.

  As is apparent from Table 1, the composite fiber yarns of Examples 1 to 5 satisfy the desired actual crimp rate and the latent crimp rate, and the obtained woven fabric has stretch properties, surface smoothness and All of the softness was good. In particular, since the composite fiber yarns of Examples 1, 3 and 4 had a preferable amount of copolymerization of NPG, the stretchability of the woven fabric comprising the yarns was particularly excellent.

  On the other hand, the composite fiber yarn of Comparative Example 1 was inferior in latent crimp rate because IPA was copolymerized in place of NPG, and the resulting woven fabric was inferior in stretchability and softness.

  Since the composite fiber yarn of Comparative Example 2 was copolymerized with NPGEO adduct instead of NPG, the actual crimp rate and the latent crimp rate exceeded the desired values, and the resulting woven fabric had surface smoothness. It became inferior. Furthermore, the Tg of the high heat-shrinkable polyester (A) is lowered, and when the resulting woven fabric is heat-treated, fusion of the composite fiber yarns constituting the woven fabric occurs, so that the woven fabric is stretchable and soft. It became inferior.

  The composite fiber yarn of Comparative Example 3 has a large amount of copolymerized NPG, the actual crimp rate exceeds 5%, and the latent crimp rate also exceeds 40%. Although the properties were good, the surface smoothness was poor and the embossing was conspicuous.

  Since the composite fiber yarn of Comparative Example 4 had a low NPG copolymerization amount and a latent crimp rate of less than 20%, the resulting woven fabric had good surface smoothness but had good stretch properties and softness. It became inferior.

  Since the composite fiber yarn of Comparative Example 5 had a latent crimp rate of less than 20%, the resulting woven fabric was inferior in stretchability and softness.

  Since the composite fiber yarn of Comparative Example 6 had a latent crimp rate of over 40%, the stretch property was good, but the surface smoothness was poor.

Claims (3)

A yarn obtained by converging a latent crimpable polyester composite fiber in which a high heat-shrinkable polyester (A) and a low heat-shrinkable polyester (B) are bonded to a side-by-side type or an eccentric core-sheath type, Polyester (A) contains 4 to 10 mol% of a neopentyl glycol component as a copolymerization component, the yarn has a three-dimensional spiral-like manifest crimp, and the apparent crimp rate (C0 (%)) of the yarn A latent crimpable polyester composite fiber yarn characterized by satisfying the formula (I) and the latent crimp ratio (C100 (%)) satisfying the formula (II).
0 <C0 (%) ≦ 5 (I)
20 ≦ C100 (%) ≦ 40 (II)
C0 (%) = [(L0−L1) / L0] × 100
C100 (%) = [(A0−A1) / A0] × 100
L1: Knot length while applying a tension of 90.91 × 10 ⁻³ cN / dtex to the yarn, applying a load of 1.67 × 10 ⁻⁴ cN / dtex to the knot, and standing for 30 minutes L0: After the L1 measurement, the length A1: when the load is changed from 1.67 × 10 ⁻⁴ cN / dtex to 90.91 × 10 ⁻³ cN / dtex, the yarn has 90.91 × 10 ⁻³ cN / dtex. Remove the wrinkle while applying tension, and after boiling water for 30 minutes while applying a load of 1.67 × 10 ⁻⁴ cN / dtex, apply a load of 1.76 × 10 ⁻³ cN / dtex and leave it for 30 minutes. Later saddle length A0: The saddle length when the load is changed from 1.76 × 10 ⁻³ cN / dtex to 4.4 × 10 ⁻² cN / dtex after A1 measurement.   The latent heat according to claim 1, wherein the high heat-shrinkable polyester (A) comprises only a terephthalic acid component, an ethylene glycol component and a neopentyl glycol component, and the low heat-shrinkable polyester (B) is polyethylene terephthalate. Crimpable polyester composite fiber yarn.   A woven or knitted fabric comprising the latent crimpable polyester composite fiber yarn according to claim 1 or 2.