WO2024018814A1 - False-twist textured yarn, and clothes, woven knitted product, twist yarn, and composite false-twist textured yarn including same - Google Patents

Abstract

A false-twist textured yarn according to the present invention comprises a polyester thermoplastic resin A and a polyester thermoplastic resin B and satisfies the following requirements in order to provide a false-twist textured yarn and a composite false-twist textured yarn, a twist yarn, a woven knitted product, and clothes that include the same, said false-twist textured yarn providing feelings such as dryness and resilience, having a high grainy feel with suppressed glare, and realizing functionalities such as high sensitiveness and stretchability with a worsted-yarn like feature having a natural appearance. (1) The difference (M_A-M_B) between the weight average molecular weight M_A of the polyester thermoplastic resin A and the weight average molecular weight M_B of the polyester thermoplastic resin B is 2,000-15,000. (2) The polyester thermoplastic resin A and the polyester thermoplastic resin B are bonded in an eccentric manner. (3) The apparent thick-thin ratio (D_thick/D_thin) of the false-twist textured yarn is 1.05-3.00. (4) A slit in the fiber axis direction is provided in the surface of the false-twist textured yarn, and a crack in the direction substantially orthogonal to the fiber axis direction is provided in said surface.

Description

False-twisted yarns, composite false-twisted yarns containing the same, twisted yarns, woven and knitted fabrics, and clothing

The present invention relates to false-twisted yarns, composite false-twisted yarns, twisted yarns, woven and knitted fabrics, and clothing containing the same.

Even among wool materials, there has been a demand for worsted fabrics that combine softness, dryness, resilience, and natural appearance with high sensitivity and stretch functionality.

Until now, wool-like fabrics have been produced that have thick and thin spots in the fiber axis direction of single fibers constituting a multifilament made by bonding two types of polyester polymers with different melt viscosities, as disclosed in Patent Document 1, for example. Fibers and woven and knitted fabrics using them have been proposed. Further, Patent Document 2 proposes a polyester composite false twisted yarn made of a polyester yarn having latent crimp performance and another polyester yarn.

Japanese Patent Application Publication No. 2004-124271 JP 2017-214698 Publication

One possible way to obtain a worsted-like natural appearance and stretchability is to stretch a conjugate fiber that has a crimp structure, as seen in wool, to give it thick and thin spots. However, although the technology disclosed in Patent Document 1 has crimps and thick spots, the cross-sectional shape of the single fibers that make up the multifilament is constant, so there is a problem that it is not possible to obtain a natural appearance and dry feel. There is.

Furthermore, although the technology disclosed in Patent Document 2 performs false twisting, the multifilaments take a close-packed structure in the false-twisting process, making the single yarn surface smooth and making it impossible to obtain a natural appearance. There is a problem. In other words, it was not possible to simultaneously satisfy the texture of dryness and resilience, the high sensitivity of worsted hair such as a natural appearance, and the functionality of stretchability.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to have a worsted-like texture that has a dry feel, resilience, and a natural appearance with a high heathered feel and suppressed glare. An object of the present invention is to provide a false-twisted yarn that exhibits functionality such as high sensitivity and stretchability, as well as composite false-twisted yarns, twisted yarns, woven or knitted fabrics, and clothing containing the false-twisted yarn.

The present invention has the following configuration.

[1] A false twisted yarn containing polyester thermoplastic resin A and polyester thermoplastic resin B and satisfying the following requirements.
(1) The difference (M _A − M _B ) between the weight average molecular weight M _A of the polyester thermoplastic resin A and the weight average molecular weight M _B of the polyester thermoplastic resin B is 2,000 to 15,000.
(2) The polyester thermoplastic resin A and the polyester thermoplastic resin B are eccentrically joined.
(3) The apparent thick/thin ratio (D _thick /D _thin ) of the false twisted yarn is 1.05 to 3.00.
(4) The surface of the false twisted yarn has slits in the fiber axis direction and cracks in a direction substantially perpendicular to the fiber axis direction.

[2] The false twisted yarn according to [1], wherein the single yarn fineness is 3.0 dtex or more.

[3] The false twisted yarn according to [1] or [2], which has a stretch recovery rate (CR) of 25.0% or more.

[4] A composite false-twisted yarn comprising the false-twisted yarn according to any one of [1] to [3] and at least one other yarn.

[5] The composite false twisted yarn according to [4], wherein the other yarn is an overtly crimped yarn.

[6] Contains either the false twisted yarn according to any one of [1] to [3] or the composite false twisted yarn according to [4] or [5], and has a twist coefficient of 1200 to 6000. , twisted yarn.

[7] At least one of the false twisted yarn according to any one of [1] to [3], the composite false twisted yarn according to [4] or [5], or the twisted yarn according to [6] Woven and knitted fabrics included in this section.

[8] Clothing at least partially containing the woven or knitted fabric according to [7].

According to the present invention, the false twisting process has a texture such as a dry feeling and resilience, a high heathered feel, suppressed glare, a natural appearance, high sensitivity of a worsted texture, and functionality such as stretchability. Yarn is obtained. In particular, composite false-twisted yarns, twisted yarns, woven and knitted fabrics, and clothing using the false-twisted yarn of the present invention are useful for items in the field of outwear worn as women's and men's clothing, such as jackets, suits, bottoms, etc. It can be suitably used for.

FIG. 1 is a cross-sectional view showing an example of the existence form of polyester thermoplastic resin A and polyester thermoplastic resin B in the false twisted yarn of the present invention. FIG. 2 is a cross-sectional view showing another example of the presence of the polyester thermoplastic resin A and the polyester thermoplastic resin B in the false twisted yarn of the present invention. FIG. 3 is a perspective view illustrating one embodiment of the surface of the false twisted yarn of the present invention. FIG. 4 is a schematic diagram of a false-twisting apparatus used in manufacturing the false-twisted yarn of the present invention. FIG. 5 is a schematic diagram of a final distribution plate according to Example 1 of the false twisted yarn of the present invention. FIG. 6 is a schematic diagram of a final distribution plate according to Comparative Example 8 of the false twisted yarn of the present invention.

The false twisted yarn of the present invention contains polyester thermoplastic resin A and polyester thermoplastic resin B, and satisfies the following requirements.
(1) The difference (M _A − M _B ) between the weight average molecular weight M _A of the polyester thermoplastic resin A and the weight average molecular weight M _B of the polyester thermoplastic resin B is 2,000 to 15,000.
(2) The polyester thermoplastic resin A and the polyester thermoplastic resin B are eccentrically joined.
(3) The apparent thick/thin ratio (D _thick /D _thin ) of the false twisted yarn is 1.05 to 3.00.
(4) The surface of the false twisted yarn has slits in the fiber axis direction and cracks in a direction substantially perpendicular to the fiber axis direction.

The present invention will be described in detail below, but the present invention is not limited to the scope described below unless it exceeds the gist thereof.

[Polyester thermoplastic resin A, polyester thermoplastic resin B]
The false twisted yarn of the present invention is obtained by false twisting a composite fiber containing a polyester thermoplastic resin A and a polyester thermoplastic resin B. False twisting creates a random crimp pattern for each single yarn, giving it a dry feel, stretch, and resilience.

Therefore, the false twisted yarn of the present invention contains polyester thermoplastic resin A and polyester thermoplastic resin B.

Specific examples of the polyester resin used in the false twisted yarn of the present invention include polyethylene terephthalate resin whose main repeating unit is ethylene terephthalate, polytrimethylene terephthalate resin whose main repeating unit is trimethylene terephthalate, or A polybutylene terephthalate resin whose main repeating unit is butylene terephthalate is preferred. More preferably, the main repeating unit of both the polyester thermoplastic resin A and the polyester thermoplastic resin B is ethylene terephthalate. Here, "the main repeating unit is ethylene terephthalate" means that the proportion of the structure derived from ethylene terephthalate contained in the repeating unit is 60 mol% or more. The same applies hereafter.

The above polyethylene terephthalate resin, polytrimethylene terephthalate resin, and polybutylene terephthalate resin may contain a small amount (usually less than 30 mol% (amount relative to the total amount of acid component and diol component 100 mol%)) of a copolymerized component as necessary. may have. It is preferable that the copolymerization component of the polyester thermoplastic resin A is 8 mol % or less, since it is easy to maintain strength even after alkali weight loss and to obtain softness. Further, by controlling the copolymerization component to 8 mol % or less, the molecular orientation in the false-twisted yarn can be maintained even after dyeing, thereby improving dimensional stability. Further, preferably both the polyester thermoplastic resin A and the polyester thermoplastic resin B have a copolymerization component of 5 mol% or less, and more preferably, both the polyester thermoplastic resin A and the polyester thermoplastic resin B contain a copolymerization component. Polyethylene terephthalate resin. By using polyethylene terephthalate that does not contain copolymerized components, the boiling water shrinkage rate of the false twisted yarn can be easily lowered, making it easier for crimp to occur in woven or knitted fabrics, resulting in stretchability and resilience. This makes it easier to recycle the fibers, and it also makes it easier to recycle the fibers.

In the present invention, the boiling water shrinkage rate of the false twisted yarn after false twisting and before crack formation (hereinafter referred to as the false twisted yarn before crack formation) is preferably 10.0% or less. When the boiling water shrinkage rate is 10.0% or less, the fibers are not restricted in the woven or knitted fabric and the stretchability is further improved.

In addition, in the polyester thermoplastic resin A and the polyester thermoplastic resin B in the present invention, a micropore forming agent, a cationic dyeing agent, and a coloring inhibitor may be added as necessary within a range that does not impair the purpose of the present invention. , a heat stabilizer, a flame retardant, a fluorescent whitening agent, a matting agent, a coloring agent, an antistatic agent, a hygroscopic agent, an antibacterial agent, an inorganic fine particle, etc. may be contained one or more.

The false twisted yarn of the present invention has a difference between the weight average molecular weight M _A of the polyester thermoplastic resin A and the weight average molecular weight M _B of the polyester thermoplastic resin B (M _A - M _B , hereinafter simply referred to as "weight average molecular weight M B"). The molecular weight difference (sometimes referred to as "difference in molecular weight") is between 2,000 and 15,000. If the difference in weight average molecular weight is less than 2000, the stretchability of the false twisted yarn will be low and the glare suppression effect will be insufficient. The difference in weight average molecular weight is preferably 5000 or more. On the other hand, if the difference in weight average molecular weight is greater than 15,000, the strength of the yarn decreases and spinning becomes unstable. The difference in weight average molecular weight is preferably 13,000 or less.

Further, the weight average molecular weight M _A of the polyester thermoplastic resin A is preferably in the range of 20,000 to 28,000, and the weight average molecular weight M _B of the polyester thermoplastic resin B is preferably in the range of 12,000 to 20,000. It is preferable that When each of these values is within this range, the functionality and durability of the false-twisted yarn are improved, and the process stability when spinning the composite fiber that is the source of the false-twisted yarn is also improved.

Note that the weight average molecular weight in the present invention is measured by the method described in Examples.

[False twisted yarn]
In the false twisted yarn of the present invention, polyester thermoplastic resin A and polyester thermoplastic resin B are eccentrically joined. By doing so, the shrinkage difference between the polyester thermoplastic resin A and the polyester thermoplastic resin B results in a coil-like structure, so that the stretchability of the obtained fabric is improved. Here, "joined eccentrically" means a state in which polyester thermoplastic resin A and polyester thermoplastic resin B are joined without being substantially separated in a cross section that is substantially perpendicular to the fiber axis of the false twisted yarn. This refers to a state in which the centers of gravity of each object are shifted from each other. Examples of eccentrically joined structures include side-by-side and eccentric core-sheath structures, and structures made of polyester thermoplastic resin A (1) as shown in the cross-sectional shape of the false twisted yarn in Figure 1. Examples include a structure in which a portion is exposed from the polyester thermoplastic resin B(2).

At this time, if the false twisted yarn is of side-by-side type, it is necessary to form slits parallel to the fiber axis direction in the polyester thermoplastic resin B at the time of forming the composite fiber before false twisting.

When the false twisted yarn is an eccentric core-sheath type, as shown in FIG. 2, the cross-sectional structure is such that polyester thermoplastic resin A (1) is covered with polyester thermoplastic resin B (2).

The false twisted yarn having the cross-sectional structure shown in FIG. 1 can be obtained, for example, by obtaining an eccentric core-sheath type conjugate fiber and then exposing a part of the polyester thermoplastic resin A by alkali reduction. At this time, by forming an eccentric core-sheath type composite fiber using polyester thermoplastic resins with the above-mentioned difference in weight average molecular weight, fine particles are formed at the bonding interface between polyester thermoplastic resin A and polyester thermoplastic resin B. It is possible to stably form irregularities, and by exposing a part of the polyester thermoplastic resin A, these irregularities are exposed and become slits to be described later.

In addition, when the composite fiber is an eccentric core-sheath type, the minimum value t _min of the thickness t (3) of the polyester thermoplastic resin B (2) covering the polyester thermoplastic resin A (1) and the The ratio (t _min /D) to the fiber diameter D is preferably 0.01 to 0.10. When (t _min /D) is 0.01 or more, the quality of the fabric is improved in that the generation of fuzz is suppressed, and the slit forming property is improved. (t _min /D) is preferably 0.02 or more. On the other hand, when (t _min /D) is 0.10 or less, stretchability is further improved due to sufficient crimp development force. (t _min /D) is preferably 0.08 or less.

In addition, when the composite fiber is of an eccentric core-sheath type, in the cross section, the length of the portion where the region where the thickness t satisfies 1.00t _min ≦t≦1.05t _min and the peripheral line of the composite fiber overlaps C _t It is preferable that C _t ≧0.33C with respect to the circumferential length C of the entire composite fiber. By doing this, compared to conventional eccentric core-sheath composite fibers in which the ratio of the area of polyester thermoplastic resin A (S _A ) and the area of polyester thermoplastic resin B (S _B ) in the cross section is the same. Since the centers of gravity of the regions where each resin exists are separated, the resulting crimped fibers can form finer spirals and exhibit better crimp. It is more preferable that C _t ≧0.40C. Further, in principle, C _t <C, but preferably C _t ≦0.70C.

Further, the false twisted yarn of the present invention has an apparent thick/thin ratio (D _thick /D _thin ) of 1.05 to 3.00. In the present invention, the apparent thick/thin ratio (D _thick /D _thin ) refers to the portion where the width of the false twisted yarn bundle in the direction orthogonal to the fiber axis direction at a load of 0.11 cN/dtex is relatively thicker than the average value. It is the ratio of the fiber diameter (D _thick ) of the fiber to the fiber diameter (D _thin ) of the portion that is relatively thinner than the average value. If the apparent thick/thin ratio (D _thick /D _thin ) of the false twisted yarn of the present invention is less than 1.05, a heathered appearance cannot be obtained when it is made into a woven or knitted fabric. (D _thick /D _thin ) is preferably 1.25 or more, more preferably 1.40 or more. Furthermore, if (D _thick /D _thin ) exceeds 3.00, the appearance will deviate from the natural appearance and will not be desirable. (D _thick /D _thin ) is preferably 2.00 or less.

Note that the specific measuring methods for the above-mentioned thickness t, fiber diameter D, thick-to-thin ratio, circumferential length C, etc. are as described in the examples.

Further, the false twisted yarn of the present invention has slits in the axial direction of the single fibers and cracks in a direction substantially perpendicular to the axial direction of the single fibers on the surface of the single fibers. By having unevenness in the direction of the single fiber axis and in a direction substantially perpendicular thereto, light can be scattered from all angles, and a natural appearance with suppressed glare can be achieved. In the present invention, a crack is an unevenness in a direction substantially perpendicular to the single fiber axis direction of the false twisted yarn, and the depth of the crack is preferably 0.5 to 5.0 μm. Furthermore, in the present invention, slits are irregularities formed in the axial direction of the single fibers of the false twisted yarn, and the depth of the slits is preferably 0.1 to 1.5 μm. When the depth of the crack is 0.5 μm or more or the depth of the slit is 0.1 μm or more, the glare suppression effect is further improved. Furthermore, wear resistance is improved by making the depth of the slits 5.0 μm or less, or 1.5 μm or less.

For the same reason, the width of the crack is preferably 1.0 to 30.0 μm, and the width of the slit is preferably 0.1 to 10.0 μm. Moreover, it is preferable that the length of the slit is 100 μm or more.

Here, the depth of each crack or slit shall be measured at its deepest point. Furthermore, the direction substantially perpendicular to the fiber axis direction of the false twisted yarn is the direction along the circumference of the single fibers of the false twisted yarn 4, as schematically illustrated in FIG. The direction is within ±80° with respect to the axial direction. FIG. 3 is a perspective view illustrating one embodiment of the surface of the false twisted yarn of the present invention, in which the single fiber surface of the false twisted yarn 4 has slits 6 in the single fiber axis direction. It has a crack 5 in a direction substantially perpendicular to the direction. The length of such a crack is not particularly limited. _{It usually varies depending on the ratio S A :S B of} the polyester thermoplastic resin A area (S _A ) and the polyester thermoplastic resin B area (S _B ) of the false twisted yarn before crack formation, which will be described later. When the ratio is around 50:50 (for example, about 40 to 60:60 to 40), cracks are likely to form in an area of about 1/2 of the outer circumference of the single fiber of the false twisted yarn. It is preferable that the length be about 1/2 of the outer circumference of a single fiber of the false twisted yarn, since this has a good balance with slit formation and glare can be further suppressed when it is made into a woven or knitted fabric. Here, the above-mentioned "approximately 1/2 of the length of the outer circumference" may mean that one crack forms about 1/2 of the length of the outer circumference of the single fiber, or 2 The above-mentioned cracks may be formed in a dispersed manner in an area of about 1/2 of the length of the outer circumference of the single fiber. Further, it does not have to be strictly 1/2 of the length of the outer circumference, and approximately 1/2 circumference is sufficient.

In addition, as for the frequency of crack formation, it is preferable that the number of cracks is 10 or less and the dispersion form is such that it covers almost the entire area in the outer circumferential direction of the area where no slits are formed, and such a dispersion form is such that the cracks are formed in 10 or less cracks. It is more preferable that cracks are formed at a frequency within a range of 1 cm in the direction.

Furthermore, the fiber axis direction of the false-twisted yarn is the longitudinal direction of the false-twisted yarn 4, as schematically illustrated in FIG. The length in the circumferential direction of the false twisted yarn in which such slits are formed is not particularly limited, but it is recommended that it be about 1/2 of the circumferential length of a single fiber of the false twisted yarn to prevent crack formation. It is preferable because it has good balance and can further suppress glare when made into a woven or knitted fabric. Furthermore, it is particularly preferable that both cracks and slits be formed in the single fibers constituting the false twisted yarn. In that case, as shown in FIG. 3, it is preferable to have a region in which cracks are formed in about half the outer circumference and a region in which slits are formed in about half the outer circumference.

In the present invention, the depth and length of each crack or slit are observed using an electron microscope, and the average value of 10 cracks or slits measured within one false twisted yarn is used. The specific measurement method is as described in Examples.

Examples of the method for forming cracks on the surface of the false-twisted yarn include a method of alkali reduction of the false-twisted yarn after pin stretching within a range not exceeding the natural stretching ratio of the composite fiber. By setting the above stretching ratio, a difference in the orientation of the molecules constituting the composite fiber occurs in the length direction of the fiber, and the unoriented portion is preferentially eluted by alkali, so that the weight loss rate increases with the fiber length. This results in different directions, and unevenness, that is, cracks, are formed in a direction substantially orthogonal to the fiber axis direction.

The method for forming slits on the surface of the false twisted yarn is to change the shape of the discharge hole from the usual circular shape when obtaining composite fibers, and to change the shape of the discharge hole to have a multi-lobed cross section with 8 or more protrusions. An example of this method is to create unevenness in the fiber axis direction.

Furthermore, slits can also be formed by obtaining a false twisted yarn from a composite fiber with an eccentric core-sheath structure and then reducing the yarn with alkali. Here, a method for forming slits based on a composite fiber having an eccentric core-sheath structure will be described in detail. By spinning polyester thermoplastic resin A and polyester thermoplastic resin B with the above-mentioned molecular weight difference using a distribution plate described later, unevenness is created at the joint interface of the eccentric core-sheath structure due to the viscosity difference of each thermoplastic resin. is formed. Furthermore, in alkali weight loss of woven or knitted fabrics using false twisted yarn, polyester thermoplastic resin B is preferentially reduced, so polyester thermoplastic resin A is exposed and the unevenness at the bonding interface is exposed. This results in the formation of unevenness (slits) in the direction of the fiber axis.

It is preferable to make the slit based on the above-mentioned conjugate fiber with an eccentric core-sheath structure because it can be formed more stably and the slit can be made deep.

By satisfying the above-mentioned requirements (1) to (4) at the same time, the present invention achieves textures such as dryness and resilience, which were issues with conventional false twisted yarns, as well as high combed-like sensitivity and stretch, such as a natural appearance. Both characteristics of functionality such as gender can be solved at once.

Further, the cross-sectional shape of the false twisted yarn is not particularly limited, and a circular, elliptical, triangular, etc. cross-sectional shape can be adopted, but a circular cross-sectional shape is preferable for the composite fiber for obtaining the false twisted yarn. It is more preferable because it allows stable spinning.

In the present invention, the ratio S A :S _B of the area of polyester thermoplastic resin A (S _A ) to the area of polyester thermoplastic resin B (S _B ) in the cross section of the false twisted yarn before crack formation _is When the ratio is preferably 70:30 to 30:70, more preferably 60:40 to 40:60, physical properties are improved. Further, in order to make the crimps of the false twisted yarn more fine, it is further preferable that S _A ≧ _SB .

The single yarn fineness of the false twisted yarn in the present invention is preferably 3.0 dtex or more. Further, the upper limit is preferably 5.0 dtex or less. By setting it within this range, the dry feel when made into a woven or knitted fabric becomes high, and a texture closer to that of worsted wool can be obtained. In the present invention, the single yarn fineness is a value calculated from the total fineness (dtex)/number of filaments.

Further, it is preferable that the false twisted yarn of the present invention has a crimp rigidity (CR) of 25.0% or more as measured from the decomposed yarn of the woven or knitted material. When the CR is 25.0% or more, the woven or knitted fabric exhibits more crimp and better stretchability. CR is more preferably 30.0% or more. Moreover, CR is preferably 50.0% or less. When the CR is 50.0% or more, the swelling of the woven or knitted fabric is prevented from becoming too strong, and appropriate resilience is easily obtained. CR can be measured by the method described in Examples, including when using the composite false twisted yarn described below. Further, as a method for setting the CR within the above range, the stretching ratio during false twisting may be increased to increase the orientation difference between the polyester thermoplastic resin A and the polyester thermoplastic resin B.

[Composite false twisted yarn]
The composite false twisted yarn of the present invention comprises the false twisted yarn of the present invention and at least one other yarn. By doing so, the heathered feel of the woven or knitted fabric becomes even better.

Other yarns are not particularly limited as long as they are different from the false twisted yarn of the present invention, but among them, polyester yarns are preferred because they have good mechanical properties and excellent dimensional stability against changes in humidity and temperature. Preferably, it is made of resin. Specific examples of polyester resins include polyethylene terephthalate resins whose main repeating unit is ethylene terephthalate, polytrimethylene terephthalate resins whose main repeating unit is trimethylene terephthalate, or polybutylene whose main repeating unit is butylene terephthalate. Terephthalate resins are preferred. In addition, the above polyethylene terephthalate resin or polybutylene terephthalate resin may have a small amount (usually less than 30 mol% (amount relative to the total 100 mol% of acid component and diol component)) of a copolymer component, if necessary. good. Furthermore, from the viewpoint of soft texture and fiber recycling, it is more preferable that all yarns constituting the composite false twisted yarn are made of polyethylene terephthalate resin containing no covalent components.

Further, it is preferable that the boiling water shrinkage rate of the other yarns is 10.0% or less. When the boiling water shrinkage rate is 10.0% or less, the false twisted yarn and other yarns are less likely to be restricted in the woven or knitted fabric, and the stretchability is further improved.

Furthermore, it is preferable that the other yarns are obviously crimped yarns. Here, the term "actually crimped yarn" refers to a yarn with an expansion/contraction recovery rate of 5.0% or more, such as a yarn in which two types of polymers with different contractility are combined in a side-by-side or eccentric core-sheath type, or a yarn with a false twist. This shows something that has been mechanically crimped by processing. In that case, the CR of the other yarns is preferably 10.0 to 20.0% higher than the CR of the false twisted yarn. By setting the CR in this range, the false twisted yarn and crimps with different coil diameters are mixed in the composite false twisted yarn, so it is possible to obtain a dry feel closer to that of worsted yarn without impeding stretchability. . In addition, it is preferable that the other threads as the raw threads before being combined are latent crimped threads. After the latent crimped yarn is combined, it undergoes a process such as dyeing to become an actual crimped yarn that constitutes the composite false twisted yarn of the present invention.

[Twisted yarn]
The twisted yarn of the present invention includes either the above-mentioned false-twisted yarn or the above-mentioned composite false-twisted yarn, and has a twist coefficient of 1200 to 6000. By using the false twisted yarn or the composite false twisted yarn as a twisted yarn and setting the twist coefficient within the above range, the process passability of the weaving process is improved while maintaining stretchability. The twist coefficient is preferably 1500 to 4500. Here, the twist coefficient can be calculated using the following formula.

Twist coefficient (K) = number of twists (T/m) x √ (fineness (dtex) x 0.9).

It is preferable that the twisting direction is the same as the twisting direction of false twisting. If the twisting direction and the false twisting direction are the same, the resilience is further improved.

[Woven and knitted fabrics]
The woven or knitted fabric of the present invention contains at least a portion of the false twisted yarn, composite false twisted yarn, or twisted yarn thereof of the present invention. The proportion of these used is preferably 30% by mass or more, more preferably 40% by mass or more based on the mass of the woven or knitted material. It is also a preferred embodiment that all of the fibers constituting the woven or knitted fabric are made of any one of the false twisted yarn, composite false twisted yarn, and twisted yarn of the present invention.

The fabric structure of the woven or knitted fabric of the present invention is a woven fabric or a knitted fabric. The fabric structure is selected from plain weave, twill weave, satin weave, and variations thereof depending on the texture and design. Furthermore, a multiple weave structure such as a double weave may be used. The knitting structure may be selected according to the desired texture and design, and examples of weft knitting include jersey knitting, rubber knitting, pearl knitting, tuck knitting, floating knitting, lace knitting, and variations thereof. Warp knitting includes single denby knitting, single vandyke knitting, single cord knitting, Berlin knitting, double denby knitting, atlas knitting, cording knitting, half tricot knitting, satin knitting, sharkskin knitting, and their variations. can be mentioned. Among these, relatively simple weaving and knitting structures such as plain weave or its variations, twill weave or its variations, and satin weave are more preferable in order to have a delicate worsted texture and a deep natural appearance.

[clothing]
The clothing of the present invention includes at least a portion of the woven or knitted fabric of the present invention. By doing so, the false twisted yarn, composite false twisted yarn, twisted yarn, or woven or knitted fabric of the present invention can have a texture such as dryness and resilience, and a high combed-like sensitivity and stretchability such as a natural appearance. It can be made into functional clothing. The clothing of the present invention refers to items in the field of outwear worn as women's and men's clothing, sports clothing, and outdoor clothing, particularly jackets, suits, bottoms, and parts thereof, such as front bodies, back bodies, and collars. These items include items such as jackets, sleeves, chest pockets, and side pockets, as well as innerwear, socks, and hats.

[Production method of false twisted yarn and woven and knitted fabrics]
Next, a preferred example of a method for producing the false twisted yarn and woven or knitted fabric of the present invention will be described.

The false-twisted yarn of the present invention can be produced by false-twisting a composite fiber obtained by winding the discharged thermoplastic resin as an undrawn yarn or a semi-drawn yarn, and then performing alkali weight reduction. In particular, the use of composite fibers obtained in the process of winding and stretching as semi-drawn yarns for false twisting makes it possible to fabricate woven or knitted fabrics and dye them due to the orientation difference between polyester thermoplastic resin A and polyester thermoplastic resin B. It is preferable because it has particularly excellent stretchability when processed, and because the polyester resin A is highly oriented, it has excellent resistance to embrittlement due to alkali weight loss.

[Spinning process]
In the method for producing a false twisted yarn of the present invention, first, polyester thermoplastic resin A and polyester thermoplastic resin B are respectively melted and discharged from a spinneret, preferably at 1400 m/min to 3800 m/min. The yarn is wound as an undrawn yarn or a semi-drawn yarn at a spinning speed of 10 minutes. In the present invention, it is preferable to wind the yarn as a semi-drawn yarn at a spinning speed of 2,500 m/min to 3,800 m/min.

In the present invention, it is preferable to make the false twisted yarn of the present invention from a semi-drawn yarn because it has excellent abrasion resistance after alkali weight loss. Since the semi-drawn yarn has more advanced crystallization than the undrawn yarn, local fiber breakage due to alkali weight loss can be suppressed.

The spinning temperature is preferably +20°C to +50°C with respect to the melting points (T _mA , T _mB ) of the polyester thermoplastic resin A and the polyester thermoplastic resin B. (T _mA , T _mB )+20° C. or higher can prevent the melted polyester thermoplastic resin A and polyester thermoplastic resin B from solidifying and clogging inside the spinning machine piping. On the other hand, by setting the temperature to (T _mA , T _mB )+50° C. or lower, thermal deterioration of the molten polyester thermoplastic resin A and polyester thermoplastic resin B can be suppressed.

The spindle used in the method for producing false twisted yarn of the present invention may have any known internal structure as long as it is capable of spinning with stable quality and operation.

Here, when the cross section of the false twisted yarn of the present invention is a side-by-side type, by making the shape of the nozzle uneven, a slit in a direction substantially parallel to the fiber axis direction can be obtained on the surface of the polyester thermoplastic resin A.

In addition, by using an eccentric core-sheath type composite fiber cross section, we can solve the problem of the difference in flow velocity between two types of thermoplastic resins discharged from the die, which is a problem when manufacturing composite fibers before false twisting. It is also possible to suppress the bending of the discharge line.

In order to make the composite fiber have an eccentric core-sheath type cross section, the minimum value t _min of the thickness t of the polyester thermoplastic resin B covering the polyester thermoplastic resin A and the thickness in the cross section of the composite fiber are determined as described above. It is preferable to precisely control the length C _t of the portion where the region where t satisfies 1.00t _min ≦t≦1.05t _min and the peripheral line of the composite fiber overlaps, as disclosed in Japanese Patent Application Laid-Open No. 2011-174215. A spinning method using a distribution plate is preferably used, as exemplified in JP-A No. 2011-208313 and JP-A No. 2012-136804. By using such a distribution plate, t _min can be brought within the ranges mentioned above. The obtained eccentric core-sheath type conjugate fiber may be used as an eccentric core-sheath type false-twisted yarn as it is, or may be made into a false-twisted yarn having a cross-sectional structure as shown in FIG. 1 by alkali reduction.

When forming a false twisted yarn with a cross-sectional structure as shown in FIG. Forms unevenness parallel to the fiber axis direction on the composite interface of the composite fiber. Therefore, by false-twisting eccentric core-sheath type composite fibers and then alkali treatment, a part of the polyester thermoplastic resin B covering the polyester thermoplastic resin A is removed, and the polyester thermoplastic resin By exposing a part of A, a slit parallel to the fiber axis direction as shown in FIG. 3 can be stably obtained.

In addition, if the t _min of the composite fiber is too small, the effect of suppressing the bending of the ejected wire cannot be sufficiently obtained, and as a result, the false-twisted yarn may become fluffy, its passability through the process may be reduced, and its strength may be reduced. There are cases where Alternatively, it is possible to prevent t _min from becoming excessively large, and to allow crimp of the false twisted yarn to develop within a suitable range, thereby improving the stretchability of the woven or knitted fabric. In a method using such a distribution plate, the cross-sectional form of the single yarn can be controlled by the arrangement of the distribution holes in the final distribution plate installed most downstream among the distribution plates made up of a plurality of plates.

[False twisting process]
Next, the yarn produced through the above spinning process is pin-stretched using a false twisting device as illustrated in FIG. 4 at a stretching ratio that does not exceed the natural stretching ratio of this yarn, and then Then, false twisting is performed while drawing with a heater to form a false twisted yarn. Through this step, a desired false twisted yarn can be obtained. FIG. 4 is a schematic diagram of a false-twisting apparatus used in manufacturing the false-twisted yarn of the present invention. That is, the composite fiber 7 is heated and stretched with a hot pin 9 between the first feed roller 8 and the second feed roller 10, and further stretched with a heater 11 and a twister 12 between the second feed roller 10 and the third feed roller 13. When twisting is performed and other yarns 16 are mixed, the fibers are fed from the fourth feed roller 17 to the heater 11 along with the composite fibers 7, and the false-twisted yarn or composite false-twisted yarn is 14, and is wound up by the winding section 15.

For example, semi-drawn yarn obtained by composite spinning at a spinning speed of 2,500 m/min to 3,800 m/min is pin-stretched at a yarn speed of 100-800 m/min, at a pin-stretching ratio described below and at a hot pin temperature of 70-120°C. False twisting is performed at the heater draw ratio and heater temperature of 140 to 200°C as described below (one example of conditions: semi-drawn yarn obtained by composite spinning at a spinning speed of 2,600 m/min is subjected to a pin draw ratio of 1 at a yarn speed of 400 m/min). After pin-stretching at a hot pin temperature of 80°C and a heater stretching ratio of 1.20x and a heater temperature of 170°C, the apparent thick-to-thin ratio is 1.05 or more and 3.00 or less. Processed yarn can be obtained. Pin stretching is carried out in the range of the lower limit of the natural draw ratio x 1.2 times to the upper limit x 0.8 times, and the total draw ratio expressed by the pin draw ratio x heater draw ratio is the upper limit of the natural draw ratio x 1.1 times. By false-twisting the fibers, a desired thick-to-fine ratio can be obtained, and by alkali treatment, cracks and slits can be formed on the surface of the false-twisted yarn. Further, it is preferable that the total stretching ratio is at least 1.3 times the upper limit of the natural stretching ratio, since this increases the orientation difference between the polyester thermoplastic resins constituting the composite fibers, making it easier to obtain stretchability. Furthermore, if the false twisting process is performed at a total stretching ratio of less than the upper limit of the natural stretching ratio x 1.1 times, the processing stability will be poor, and cracks will preferentially develop due to the alkali treatment, making it difficult to form slits.

Additionally, before or after winding this false twisted yarn, other threads may be mixed with it to form a composite false twisted yarn. The composite method is not particularly limited, and general methods such as interlace blending, taslan blending, etc. may be used without any problem.

[Formation process of woven or knitted fabric]
The false-twisted yarn or composite false-twisted yarn obtained by the above false-twisting process is used to make a woven or knitted fabric. In the case of textiles, air jet looms, water jet looms, rapier looms, projectile looms, shuttle looms, etc. are used for weaving. For knitting, we used flat knitting machines, full fashion knitting machines, circular knitting machines, computerized jacquard knitting machines, sock knitting machines, tube knitting machines, tricot knitting machines, raschel knitting machines, air jet looms, Milanese knitting machines. Knit using a warp knitting machine.

[Alkali weight loss process]
Further, the woven or knitted fabric obtained in the above-described woven or knitted fabric forming step is subjected to alkali weight loss processing so that the alkali weight loss rate is 5% or more, more preferably 10 to 25%. As mentioned above, false-twisted yarns that are pin-stretched within a range that does not exceed the natural draw ratio of a composite fiber with an eccentric structure have orientation differences in the fiber length direction, and the rate of weight loss due to alkali differs in the fiber length direction. By performing the alkali weight reduction process, unevenness, that is, cracks, are formed in a direction substantially perpendicular to the fiber axis direction. In addition, in the case of forming a false twisted yarn having the structure shown in FIG. A slit is formed by exposing a portion of the At this time, the slit depth can be easily controlled by controlling the exposed state of the polyester thermoplastic resin A.

In the alkaline weight loss process, a batch type weight loss process (for example, liquid flow weight loss) is preferable because repulsion is easily obtained.

[Dyeing process]
Furthermore, if necessary, conventional scouring, relaxation treatment, intermediate heat setting, dyeing processing, and final heat setting may be performed before and/or after the above-mentioned alkali weight loss step (in the present invention, these (This process is sometimes collectively referred to as the "dying process.") In order to obtain the stretchability and resilience of the present invention, feed and tension management in each step is performed as appropriate. For example, in the axial direction of the composite fiber of the present invention, overfeed is within 10% in equipment using a roll-to-roll system that can control the feed amount, and in a batch-type liquid jet dyeing machine, excessive tension in the direction of movement can be avoided. It is desirable to control the liquid volume and flow rate to avoid this. Dyeing is preferably carried out in a dyeing solution at 110 to 130° C. using a disperse dye or a cationic dye, depending on the dyeability of the thermoplastic resin constituting the false twisted yarn or other composite yarns.

The false-twisted yarn in a woven or knitted fabric produced using the false-twisted yarn that has been false-twisted using the composite fibers described above usually develops a structure due to the thermal history in the dyeing process or the alkali weight loss process, and then winds up. Shrinkage occurs. Then, by carrying out the alkali reduction step, slits are formed in the fiber axis direction, and cracks are formed in a direction substantially perpendicular to the fiber axis direction. When a latent crimped yarn is used as another yarn in the composite false twisted yarn, the latent crimped yarn also develops a structure due to the heat history in the dyeing process or alkali weight loss process, and becomes an actual crimped yarn. becomes.

Next, the present invention will be specifically explained based on Examples. However, the present invention is not limited to these examples. In addition, in the measurement of each physical property, unless otherwise specified, the measurement was performed based on the method described above.

[Measuring method]
(1) Measurement of weight average molecular weight of thermoplastic resin Polyester thermoplastic resin A and polyester thermoplastic resin B used for composite fibers were tested using a gel permeation chromatography (GPC) tester, "TOSO GMHHR" manufactured by Tosoh Corporation. -H(S)HT" was used to measure the weight average molecular weight.

Detector: Differential refractive index detector RI (Waters-2414, sensitivity 128x)
Column: Showa Denko K.K. ShodexHFIP806M (2 columns connected)
Solvent: Tetrohydrofuran (25cm ³ )
Flow rate: 1.0mL/min
Column temperature: 30℃
Injection volume: 0.10mL
Standard material: polystyrene.

(2) Measurement of the fiber diameter D, the thickness t of the polyester thermoplastic resin B covering the polyester thermoplastic resin A, and the fiber perimeter C Multifilaments made of composite fibers are placed at 1 cm intervals in the fiber axis direction at 10 Samples were continuously embedded in an embedding agent such as an epoxy resin, and images of each sample were photographed using a transmission electron microscope (TEM) at a magnification that enabled observation of 10 or more fibers. At this time, metal staining was performed to clarify the contrast of the joint between polyester thermoplastic resin A and polyester thermoplastic resin B. As image analysis software, "WinROOF2015" manufactured by Mitani Shoji Co., Ltd. was used to measure the fiber diameter D from all single yarns in the observed image, the respective circumferential length C, and the thickness t of the polyester thermoplastic resin B. . In addition, the fiber diameter D was set as the diameter in terms of yen. Prepare 10 sets of the obtained fiber diameter D, perimeter C, thickness t, and area ratio Sa of polyester thermoplastic resin A, and average them to determine the fiber diameter D with 3 significant figures, perimeter C, and thickness. t was determined using two significant figures and was defined as the fiber diameter D, peripheral length C, thickness t, and area ratio Sa of the present invention. Further, the thickness t is measured at 360 points every 1° in the fiber circumferential direction, and the smallest one is t _min , and the area where the thickness t satisfies 1.00t _min ≦t≦1.05t _min and the peripheral line of the composite fiber are The length of the overlapping portion was defined as _Ct . Further, the area ratio Sa of the polyester thermoplastic resin A was subtracted from the total area S of the cross section to obtain the area ratio Sb of the polyester thermoplastic resin B.

(3) Measurement of apparent thick/thin ratio (D _thick /D _thin ) The false twisted yarn was extracted from the woven or knitted fabric after the dyeing process (finish heat setting) and false twisted under a load of 0.11 cN/dtex. Both ends of the processed yarn were fixed. In an image taken of the side surface of the fixed sample at 200x magnification using a digital microscope "VHX-2000" manufactured by Keyence Corporation, the diameter of the fiber bundle was measured at 500 consecutive locations at 1.0 mm intervals in the fiber axis direction. It was measured. To determine the fiber diameter of the thick part (D _thick ) and the fiber diameter of the detail (D _thin ), the part thinner than the average value of all measurement data is called "detail" (detail < average value), and the part thicker than the average value of all measurement data is called "detail" (detail < average value). This was done by setting the thick part (thick part>average value). The apparent thickness ratio was calculated by rounding off the third decimal place to two decimal places.

(4) Measurement of existence and depth of cracks and slits Any location was observed using a scanning electron microscope "S-3400N" manufactured by Hitachi, Ltd. as an electron microscope. Composite fibers were pulled out from the woven or knitted fabric after finishing heat setting without applying any external force, and the presence or absence of cracks and slits was confirmed. If cracks or slits were present, the side surfaces in the fiber axis direction were observed at a magnification of 2000 times. The deepest depth and length of the cracks and slits were measured, and the average value of 10 cracks and slits measured within one false twisted yarn was taken as the respective depth. Note that a crack refers to a groove in a direction substantially perpendicular to the fiber axis direction, and a slit refers to a groove in a direction substantially parallel to the fiber axis direction.

In the table, when an area where a crack is formed around half of the outer circumference of a single fiber or an area where a slit is formed around half of the outer periphery is observed, it is referred to as a "crack/slit" and an area where a crack is formed. A "full-circumference crack" occurs when a crack is observed extending over the entire circumference of the single fiber and no slits are observed, and a "full circumference crack" is observed when the crack is observed extending over half the circumference of the single fiber and no slits are observed. It was written as ``half circumference crack''. In addition, in the Examples and Comparative Examples described below, the width of the crack was in the range of 1.0 to 30.0 μm in all cases where cracks were present. In this region, cracks were formed with a frequency of 10 or less such that a dispersion pattern covering almost the entire area in the outer circumferential direction of the region existed within a range of 1 cm in the fiber axis direction. Furthermore, in all cases with slits, the length of the slits was 100 μm or more. Moreover, when neither cracks nor slits were observed, it was written as "none".

(5) Single yarn fineness For each fiber before weaving, the fineness/number of filaments was determined from the fineness and number of filaments measured by the following method.
Fineness: JIS L 1013:2021 Chemical fiber filament yarn test method 8.3.1 (normal fineness) a) Number of filaments: JIS L 1013:2021 Chemical fiber filament yarn test method (8.4 number of filaments).

Regarding the fibers after weaving, the false twisted yarn was extracted from the woven or knitted fabric after dyeing, and the fineness and number of filaments were determined according to JIS L1013 (2010) 8.3.1B method and JIS L1013 (2010) 8.4, respectively. The single yarn fineness was obtained by measuring the fineness/number of filaments.

In the case of a composite false-twisted yarn, it was wound without being composited for measurement and evaluated (single yarn fineness of the false-twisted yarn before crack formation). Furthermore, when heat treatment equivalent to dyeing processing and alkaline weight loss processing were performed, the same processing was performed and evaluated (single yarn fineness of false twisted yarn).

(6) Stretch recovery rate (CR)
JIS L 1013:2021 Chemical fiber filament yarn test method 8.12 except that the sample was a small skein (skein length 20 cm, number of turns 1) made from false twisted processed yarn decomposed from the sample of the woven or knitted fabric in the present invention. The stretch recovery rate (CR) was measured using the following method. The measurement was carried out five times, and the average value was rounded off to the second decimal place and calculated to one decimal place. In the case of composite false-twisted yarns, they were wound up without being composited for measurement, and when subjected to heat treatment equivalent to dyeing processing, and alkali weight loss processing, treatment equivalent to that was performed for evaluation.

(7) Boiling water shrinkage rate Using the false twisted yarn before crack formation as a sample, JIS L2013:2021 Chemical fiber filament yarn test method 8.18.1 (hot water dimensional change rate) a) method (skein dimensional change rate) It was measured.

In addition, in the case of composite false-twisted yarn, it was wound up without being composited for measurement and evaluated.

(8) Twisting coefficient The false twisted yarn or composite false twisted yarn decomposed from the sample of the woven or knitted fabric in the present invention was twisted in accordance with JIS L1013:2021 Chemical fiber filament yarn test method 8.13.1 (number of strands). The number was measured. The twist coefficient was calculated from the obtained number of twists using the following formula.
Twist coefficient (K) = number of twists (T/m) x √ (fineness (dtex) x 0.9).

(9) Stretchability of woven or knitted fabric The elongation rate in the direction along the false twisted yarn or composite false twisted yarn of the present invention was measured according to JIS L1096 (2010) 8.16.1B method. When the false-twisted yarn of the present invention or the composite false-twisted yarn of the present invention was used for both warp and warp, the elongation rate of each warp and warp was measured, and the average value was taken as the result.

(10) Glare suppression degree A woven or knitted fabric was dyed black, and the woven or knitted fabric after dyeing was observed using a digital microscope “VHX-2000” manufactured by Keyence Corporation. The observation conditions were a magnification of 50 times, illumination settings of auto 60, super charge 60 ms, and gain 0 dB. After photographing the surface of the woven or knitted fabric under the above conditions, a region (S2) with a brightness of 200 to 255 was extracted from the entire observation region (S1), and the glare suppression degree was calculated using the following formula.
Glare suppression degree = 1/(S2/S1)
The measurement was performed three times, and the average value was taken as the result.

(11) Evaluation of heather feel, dry feel, and resilience of woven and knitted fabrics Samples of the woven and knitted fabrics of the present invention were evaluated visually by 10 healthy adults (5 men and 5 women) for the heather feel of the woven and knitted fabrics. Sensory evaluation of dry feel and resilience on a five-point scale: very good (5 points), good (4 points), fair (3 points), not very good (2 points), and poor (1 point). Then, the average value of each examiner was rounded to the nearest whole number. For comparison, a fabric made of polyethylene terephthalate false twisted yarn having the same total fineness and the same number of filaments as the example and comparative example was used as normal (3 items).

[Example 1]
The polyester thermoplastic resin A was polyethylene terephthalate with a weight average molecular weight of 25,000, the polyester thermoplastic resin B was polyethylene terephthalate with a weight average molecular weight of 15,000, the spinning temperature was 290°C, the polyester thermoplastic resin A and the polyester thermoplastic resin B were The arrangement of the distribution holes in the final distribution plate installed most downstream among the distribution plates made up of multiple plates is as shown in Figure 5 so that the mass composite ratio is 50:50, and the number of discharge holes is 36 composite fiber spinnerets. FIG. 5 is a schematic diagram of the final distribution plate according to Example 1 of the false twisted yarn of the present invention, and shows the area around the group of distribution holes 18 for polyester thermoplastic resin A among the distribution holes in the final distribution plate. A group of distribution holes 19 for polyester thermoplastic resin B are formed in an eccentric core-sheath type.
In this way, an eccentric core-sheath type composite cross section (FIG. 2) in which polyester thermoplastic resin A was included in polyester thermoplastic resin B was formed. The yarn discharged from the spinneret was cooled with an air cooling device, oiled, and then wound up with a winder at a speed of 2,600 m/min to stably obtain a composite fiber as a semi-drawn yarn with a total fineness of 240 dtex and a single filament count of 36. . Regarding this composite fiber, the above-mentioned (t _min /D) was 0.02, and the relationship between C _t and C was C _t /C=0.40. Further, S _A :S _B =50:50.

Subsequently, the obtained composite fiber was fed with the semi-drawn yarn from a feed roller using a friction false twisting machine (ATF12: manufactured by TMT Machinery Co., Ltd.) at a processing speed of 400 m/min and a pin stretching ratio of 1. .40 times, pin temperature 80 degrees Celsius, heater stretch ratio 1.20 times, heater temperature: 170 degrees Celsius, false twist coefficient: 28,000, twisting direction: S, false twist processed yarn with fineness: 143 dtex. Obtained.

Next, using the above false twisted yarn as the warp and weft, a plain weave fabric was produced with a warp density of 105/2.54 cm and a weft density of 90/2.54 cm.

Furthermore, this fabric was subjected to scouring, relaxation treatment, and intermediate heat setting. After that, alkali weight loss processing (weight loss rate 20%) is performed to form cracks and slits on the single yarn surface of the false twisted yarn, and as a dyeing process, a disperse dye "Dystar Navy Blue S-GL" is used to dye the yarn at a concentration of 1.0 owf%. , dyeing was carried out at a temperature of 130°C for 30 minutes, and a final heat set was applied at 160°C. At this time, the apparent thickness ratio (D _thick /D _thin ) was 1.23, and the expansion/contraction recovery ratio (CR) was 20.0%. The results are shown in Table 1.

[Example 2]
False twisted yarn and fabric were obtained in the same manner as in Example 1, except that the total fineness of the semi-drawn yarn was 270 dtex, the pin draw ratio was 1.45 times, and the heater draw ratio was 1.30 times. . The resulting false twisted yarn had an elongation recovery rate (CR) of 28.0%, and the elongation rate of the woven fabric was 25%, indicating excellent stretchability. The results are shown in Table 1.

[Example 3]
False twisted yarn and fabric were obtained in the same manner as in Example 1, except that the pin draw ratio was 1.35 times and the heater draw ratio was 1.20 times. The results are shown in Table 1.

[Example 4]
False twisted yarn and fabric were obtained in the same manner as in Example 1 except that the pin draw ratio was 1.20 times and the heater draw ratio was 1.35 times. The results are shown in Table 1.

[Example 5]
False twisted yarn and woven fabric were obtained in the same manner as in Example 2, except that the number of spindle holes was changed and a semi-drawn yarn with a total fineness of 240 dtex and a single filament count of 48 was used. The results are shown in Table 1.

[Example 6]
In the false twisting process, semi-drawn yarns made of polyethylene terephthalate fibers are merged in front of the heater as other yarns, and the other yarns are combined at a heater draw ratio of 1.50 times and a mixed ratio of false twisted yarn is 63%. A woven fabric was obtained in the same manner as in Example 2, except that the yarn was false-twisted, the warp density was 88 threads/inch (2.54 cm), and the weft thread density was 75 threads/inch (2.54 cm). The resulting fabric had a more excellent heathered feel due to the difference in dyeing between the false twisted yarn and other yarns. The results are shown in Table 1.

[Example 7]
A semi-drawn yarn was obtained in the same manner as in Example 1, except that the number of die holes and the amount of inflow of polyester thermoplastic resin were changed, and the total fineness was 113 dtex and the number of single yarns was 24 filaments. Using this semi-drawn yarn as another yarn, a composite false twisted yarn and fabric were obtained in the same manner as in Example 6. The resulting fabric has a better heathered feel due to the difference in dyeing between the false twisted yarn and other yarns, and also has excellent stretchability due to the high CR of the other yarns. Ta. The results are shown in Table 1.

[Example 8]
A woven fabric was obtained in the same manner as in Example 2, except that the false twisted yarn obtained in Example 2 was twisted at a twist coefficient of 3000 and in the twist direction S. This twisted yarn improved the convergence of the false-twisted yarn, allowing it to pass through the weaving process well, and the stretchability and resilience of the fabric were also equivalent to those without twisting. The results are shown in Table 1.

[Example 9]
A woven fabric was obtained in the same manner as in Example 2, except that the false twisted yarn obtained in Example 2 was twisted at a twist coefficient of 3000 and in the twist direction Z. The true twisted yarn improved the convergence of the false-twisted yarn and had good passability during the weaving process. Furthermore, the stretchability of the fabric was also the same as that without twisting. The results are shown in Table 1.

[Example 10]
A woven fabric was obtained in the same manner as in Example 2, except that the false twisted yarn obtained in Example 2 was twisted at a twist coefficient of 10,000 and in the twist direction S. The true twisted yarn improved the convergence of the false-twisted yarn and had good passability during the weaving process. The results are shown in Table 1.

[Example 11]
A woven fabric was obtained in the same manner as in Example 1, except that the thermoplastic polyester resin A was a polyester having a weight average molecular weight of 25,000, which was obtained by copolymerizing 10 mol % of isophthalic acid (IPA) with respect to the acid component. The results are shown in Table 1.

[Example 12]
A woven fabric was obtained in the same manner as in Example 1, except that the polyester thermoplastic resin A was a polyester having a weight average molecular weight of 19,000. The results are shown in Table 1.

[Comparative example 1]
False twisted yarns and fabrics were obtained in the same manner as in Example 2, except that the alkali weight reduction process was not performed. The obtained fabric had no cracks or slits because it had not been subjected to alkali weight loss, had low glare suppression, and had a poor worsted appearance. The results are shown in Table 2.

[Comparative example 2]
Polyethylene terephthalate having a weight average molecular weight of 20,000 was flowed into a fiber spinneret (round holes) having 36 discharge holes at a spinning temperature of 290°C. The yarn discharged from the spinneret was cooled with an air cooling device, and after being applied with an oil agent, it was wound up with a winder at a speed of 2600 m/min, and was stably wound up as a semi-drawn yarn with a total fineness of 240 dtex and a single filament count of 36. A false-twisted fabric was obtained in the same manner as in Example 2 except that this semi-drawn yarn was used. The resulting woven fabric had poor stretchability, and because it was made of one type of thermoplastic resin, slits could not be obtained even after alkali reduction, and the degree of suppression of glare was low, resulting in poor worsted appearance. The results are shown in Table 2.

[Comparative example 3]
False twisted yarn and fabric were obtained in the same manner as in Example 2, except that polyester thermoplastic resin A was polyethylene terephthalate with a weight average molecular weight of 20,000, and polyester thermoplastic resin B was polyethylene terephthalate with a weight average molecular weight of 19,000. The obtained woven fabric had poor stretchability, and due to the small molecular weight difference, sufficient unevenness could not be obtained at the joint interface of the composite fibers, so cracks could not be formed, and the degree of suppression of glare was low, resulting in poor worsted appearance. The results are shown in Table 2.

[Comparative example 4]
In Example 2, the spinneret used was replaced with a spinneret of the type described in JP-A-09-157941 from a distribution plate type spinneret, and was made of polyester thermoplastic resin A and polyester thermoplastic resin B. A woven fabric was obtained in the same manner as in Example 2, except that the side-by-side composite fibers were used. In the case of side-by-side type composite fibers, the polyester thermoplastic resin A was exposed at the time of composite fibers, and slits were not formed even after alkali reduction, so the degree of glare suppression was low and the worsted appearance was poor. The results are shown in Table 2.

[Comparative example 5]
A woven fabric was obtained in the same manner as in Example 2, except that only stretching was performed without passing through the twister of the false twisting machine. The obtained woven fabric had a smooth surface and a poor dry feel. The results are shown in Table 2.

[Comparative example 6]
In the false twisting process of Example 2, the procedure was the same as in Example 2 except that pin stretching was not performed and the heater stretching ratio was 1.68 times, and the apparent thick/thin ratio (D _thick /D _thin ) was 1. A false twisting process and fabric of No. 02 was obtained. The resulting woven fabric has a low thick/fine ratio of false twisted yarn, is low in naturalness, has a uniform structure in the longitudinal direction of the fibers, has small differences in the longitudinal orientation of molecules constituting the fibers, and is free from cracks due to alkali loss. Because of this, glare suppression was low and the worsted appearance was poor. The results are shown in Table 2.

[Comparative Example 7]
In the false twisting process of Example 2, the pin draw ratio was set to 1.30 times, the heater draw ratio was set to 1.02 times, and false twisting process with an apparent thick/thin ratio (D _thick /D _thin ) of 3.20 was obtained. . A woven fabric was obtained in the same manner as in Example 2 except that the warp density was 88 threads/inch (2.54 cm) and the weft thread density was 75 threads/inch (2.54 cm). The resulting woven fabric had a large thick/fine ratio of the false twisted yarn, had a mechanically shaded heather, and had an inferior worsted appearance. The results are shown in Table 2.

[Comparative example 8]
In Example 2, the distribution holes of the final distribution plate of the spinneret used are such that the minimum value t _min of the thickness t of the polyester thermoplastic resin B covering the polyester thermoplastic resin A is 10 times. The arrangement was changed from FIG. 5 to FIG. 6, and a core-sheath type composite fiber consisting of polyester thermoplastic resin A and polyester thermoplastic resin B and having (t _min /D) of 0.20 was obtained. A woven fabric was obtained in the same manner as in Example 2 except for the above. FIG. 6 is a schematic diagram of the final distribution plate according to Comparative Example 1. Among the distribution holes in the final distribution plate, a group of distribution holes 18 for polyester thermoplastic resin A are surrounded by polyester thermoplastic resin B. The group of distribution holes 19 is formed to have an eccentric core-sheath type, and the arrangement is such that the minimum value t _min of the thickness t is as described above. In the obtained fabric, the polyester thermoplastic resin B covering the polyester thermoplastic resin A is thick, so even if the alkali weight reduction process is performed, the bonding interface is not exposed, so slits are not formed, and the degree of glare suppression is low. The worsted appearance was inferior. In addition, the stretchability was also poor. The results are shown in Table 2.

1: Polyester thermoplastic resin A
2: Polyester thermoplastic resin B
3: Thickness t of polyester thermoplastic resin B covering polyester thermoplastic resin A
4: False twisted yarn 5: Crack 6: Slit 7: Composite fiber 8: First feed roller 9: Hot pin 10: Second feed roller 11: Heater 12: Twister 13: Third feed roller 14: False twisted yarn or Composite false twisted yarn 15: Winding section 16: Other yarn 17: Fourth feed roller 18: Distribution hole for polyester thermoplastic resin A 19: Distribution hole for polyester thermoplastic resin B

Claims (8)

1. A false twisted yarn containing polyester thermoplastic resin A and polyester thermoplastic resin B and satisfying the following requirements.
   (1) The difference (M _A − M _B ) between the weight average molecular weight M _A of the polyester thermoplastic resin A and the weight average molecular weight M _B of the polyester thermoplastic resin B is 2,000 to 15,000.
   (2) The polyester thermoplastic resin A and the polyester thermoplastic resin B are eccentrically joined.
   (3) The apparent thickness ratio (D _thick /D _thin ) of the false twisted yarn is 1.05 to 3.00.
   (4) The surface of the false twisted yarn has slits in the fiber axis direction and cracks in a direction substantially perpendicular to the fiber axis direction.
2. The false twisted yarn according to claim 1, having a single yarn fineness of 3.0 dtex or more.
3. The false twisted yarn according to claim 1 or 2, having a stretch recovery rate (CR) of 25.0% or more.
4. A composite false-twisted yarn comprising the false-twisted yarn according to any one of claims 1 to 3 and at least one other yarn.
5. The composite false twisted yarn according to claim 4, wherein the other yarn is an overtly crimped yarn.
6. A twisted yarn having a twist coefficient of 1200 to 6000, comprising either the false twisted yarn according to any one of claims 1 to 3 or the composite false twisted yarn according to claim 4 or 5.
7. A woven or knitted fabric comprising at least a portion of the false twisted yarn according to any one of claims 1 to 3, the composite false twisted yarn according to claim 4 or 5, or the twisted yarn according to claim 6.
8. Clothing comprising at least a portion of the woven or knitted fabric according to claim 7.

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