JP7061441B2 - Heat shrinkable composite yarn and its manufacturing method - Google Patents

Description

The present invention relates to a heat-shrinkable composite yarn having excellent see-through prevention properties and suppressed deterioration of deep dyeing property, and a heat-shrinkable composite yarn obtained by heat-shrinking the heat-shrinkable composite yarn. Furthermore, the present invention relates to the heat-shrinkable composite yarn or a woven or knitted fabric using the composite yarn.

Conventionally, filaments made of synthetic resin containing inorganic oxide fine particles such as titanium oxide have been known as fibers that impart coolness and anti-shedding properties to woven and knitted fabrics. For example, Patent Document 1 describes a composite fiber composed of a portion containing a high concentration of inorganic oxide fine particles and a portion not containing inorganic oxide fine particles, having a hollow portion and having a specific cross-sectional shape. Have been described. When this composite fiber is used as a woven or knitted fabric, it is excellent in preventing see-through when wet, and can be further provided with a cool feeling and an ultraviolet ray protection property.

Further, as described in Patent Document 2, the false twist hollow multifilament yarn obtained so as to maintain a specific hollow portion effectively exhibits light reflection and refraction, and is excellent in transparency.

On the other hand, the composite fibers proposed in Patent Documents 1 and 2 are drawn yarns (SDY yarns), but from the viewpoint of simplification of the production process, cost or handleability, SDY yarns or FDY yarns are used in various clothing fields. Instead, it is becoming mainstream to use highly oriented undrawn yarn (POY yarn).

As a method for obtaining false twisted yarn from highly oriented undrawn yarn, a simultaneous drawing false twisting method is generally adopted. The false twisted yarn obtained by this simultaneous drawing and false twisting method is not inferior to the false twisted yarn obtained from a general drawn yarn in both crimping characteristics and yarn quality characteristics, and is widely used for general clothing. Further, the spindle method and the friction method are generally adopted as the false twist method in this simultaneous drawing false twist processing method.

Here, when a highly oriented unstretched hollow fiber having a hollow portion is used for general simultaneous drawing false twisting, the hollow portion of the hollow fiber is formed by physical pressure during false twisting in both the spindle method and the friction method. Since it is crushed, the target hollow ratio cannot be obtained, and there is a drawback that the original functions such as lightness of the hollow fiber are not fully exhibited.

Further, the filament containing the inorganic oxide fine particles is inferior in deep dyeing property (dyeing property by dye), and when such a filament is subjected to the simultaneous stretching false twisting process as described above, the orientation is advanced and the filament is further dyed deeply. The sex is reduced.

Japanese Unexamined Patent Publication No. 2016-113715 Japanese Unexamined Patent Publication No. 2016-13714

An object of the present invention is a heat-shrinkable composite yarn containing a false-twisted hollow multifilament containing inorganic oxide fine particles, wherein the hollow portion of the false-twisted hollow multifilament is maintained and has excellent see-through prevention. Further, it is intended to provide a heat-shrinkable composite yarn in which a decrease in deep dyeability is suppressed. Another object of the present invention is to provide a composite yarn obtained by heat-shrinking the heat-shrinkable composite yarn. Another object of the present invention is to provide a heat-shrinkable composite yarn or a woven or knitted fabric using the composite yarn.

The present inventors have conducted diligent studies to solve the above problems, and found that (i) a highly oriented unstretched hollow multifilament a having a specific structure is false-twisted under predetermined conditions using a fluid swirling nozzle. By undergoing a step of obtaining a false twist hollow multifilament a and (ii) a step of compounding the false twist hollow multifilament a and a specific polyester drawn yarn b by fluid injection processing, the hollow ratio is 3 to 3 to. It has been found that a heat-shrinkable composite yarn containing false-twisted hollow multifilament yarn maintained at 30% and having a crimp ratio of 5% or less can be obtained. Further, the heat-shrinkable composite yarn and the heat-shrinkable composite yarn have excellent see-through prevention properties, and even though they contain inorganic oxide fine particles, the deep dyeing property is deteriorated. I found that it was suppressed. Furthermore, it has been found that the heat-shrinkable composite yarn and the woven or knitted fabric containing the heat-shrinkable composite yarn heat-shrinked can have excellent see-through prevention even if it is thin and lightweight. The present invention has been completed by further studies based on such findings.

That is, the present invention provides the inventions of the following aspects.
Item 1. A heat-shrinkable composite yarn containing a false twist hollow multifilament a and a polyester drawn yarn b and having a crimp ratio of 5% or less.
The false twist hollow multifilament a has a first resin portion containing more than 2% by mass of inorganic oxide fine particles and 10% by mass or less, and a second resin portion containing 2% by mass or less of inorganic oxide fine particles. Ori,
In the cross section of the single yarn constituting the false twist hollow multifilament a, the second resin portion forms a hollow shape including the inner peripheral surface and the outer peripheral surface of the single yarn, and the first resin portion is the said. A multi-leaf shape including 6 to 30 leaves radially extending from the center side to the outer peripheral side of the hollow shape in the second resin portion is formed, and the leaf portion formed by the first resin portion is formed. May form part of the outer peripheral surface of the single yarn,
The single yarn constituting the false twist hollow multifilament a has a hollow ratio of 3 to 30% and a degree of deformation of 20% or less.
The polyester drawn yarn b has an elongation of 15 to 40% and a boiling water shrinkage rate of 10 to 25%.
Heat shrinkable composite yarn.
Item 2. Item 2. The heat-shrinkable composite yarn according to Item 1, wherein the torque is 45 T / M or more.
Item 3. Item 1 or 2, wherein the mass ratio of the false twist hollow multifilament a and the polyester drawn yarn b is (false twist hollow multifilament a) / (polyester drawn yarn) = 95/5 to 65/35. Heat shrinkable composite yarn.
Item 4. The mass ratio of the first resin portion to the second resin portion in the false twist hollow multifilament a is (first resin portion) / (second resin portion) = 30/70 to 90/10. Item 3. The heat-shrinkable composite yarn according to any one of Items 1 to 3.
Item 5. A composite yarn in which the false twist hollow multifilament a is arranged on the sheath side and the polyester fiber B is arranged on the core side.
The false twist hollow multifilament a has a first resin portion containing more than 2% by mass of inorganic oxide fine particles and 10% by mass or less, and a second resin portion containing 2% by mass or less of inorganic oxide fine particles. Ori,
In the cross section of the single yarn constituting the false twist hollow multifilament a, the second resin portion forms a hollow shape including the inner peripheral surface and the outer peripheral surface of the single yarn, and the first resin portion is the said. A multi-leaf shape including 6 to 30 leaves radially extending from the center side to the outer peripheral side of the hollow shape in the second resin portion is formed, and the leaf portion formed by the first resin portion is formed. May form part of the outer peripheral surface of the single yarn,
A composite yarn in which the single yarn constituting the false twist hollow multifilament a has a hollow ratio of 3 to 30% and a degree of deformation of 20% or less.
Item 6. A woven or knitted fabric containing the heat-shrinkable composite yarn according to any one of Items 1 to 4 or the composite yarn according to Item 5.
Item 7. Item 6. The method for producing a heat-shrinkable composite yarn according to any one of Items 1 to 4, which comprises the following steps (a) to (c).
(A) A step of preparing a highly oriented unstretched hollow multifilament yarn a satisfying the following (1) to (3) and a polyester drawn yarn b having an elongation of 15 to 40% and a boiling water shrinkage rate of 10 to 25%. 1) It has a first resin portion containing more than 2% by mass of inorganic oxide fine particles and 10% by mass or less and polyester, and a second resin portion containing 2% by mass or less of inorganic oxide fine particles and polyester.
(2) Structure In the cross section of the single yarn, the second resin portion forms a hollow shape including the inner peripheral surface and the outer peripheral surface of the single yarn, and the first resin portion is the second resin portion. Inside, a multi-leaf shape including 6 to 30 leaves radiating from the center side to the outer peripheral side of the hollow shape is formed, and the leaf portion formed by the first resin portion is the outer circumference of the single yarn. It may form a part of the surface.
(3) The single yarn has a hollow portion and has a hollow ratio of 3 to 30%.
(B) Using a fluid swirling nozzle, the highly oriented unstretched hollow multifilament yarn a has a false twist coefficient of 20000 or less, a draw ratio of 1.1 times or less, and a tension ratio of twisting / untwisting of 1.0 to 1. In step 25, a false twist process is performed to obtain a false twist hollow multifilament yarn a, and (c) the false twist hollow multifilament yarn a and the polyester drawn yarn b are combined by fluid injection processing to generate heat. The process of obtaining a shrinkable composite yarn.
Item 8. Item 7. The production method according to Item 7, wherein the highly oriented unstretched hollow multifilament yarn a prepared in the step (a) further satisfies the following (4) to (7).
(4) Structure In the cross section of the single yarn, the tip portion on the outer peripheral side of the leaf portion has a curved shape.
(5) In the cross section of the constituent single yarn, the ratio of the exposure length of the first resin portion to the outer peripheral surface of the constituent single yarn to the outer peripheral length of the constituent single yarn is 10% or less.
(6) In the cross section of the constituent single yarn, the average value of the ratio of the shortest distance from the outer circumference of the constituent single yarn to the end of the leaf to the distance from the center to the outer circumference of the constituent single yarn is 10% or less. be.
(7) The elongation is 100 to 180%.
Item 9. Item 5. The method for producing a composite yarn according to Item 5, which comprises a step of performing a heat shrink treatment on the heat-shrinkable composite yarn according to any one of Items 1 to 4.
Item 10. A method for producing a woven or knitted product, which comprises the following steps (i) to (iii).
(I) The step of preparing the heat-shrinkable composite yarn according to any one of Items 1 to 4.
(Ii) A step of weaving and knitting the heat-shrinkable composite yarn to manufacture a raw machine, and (iii) a step of performing a heat-shrinking treatment on the raw machine to obtain a woven or knitted product.

The heat-shrinkable composite yarn and the composite yarn of the present invention contain a false twist hollow multifilament yarn in which a hollow portion is maintained, have excellent see-through prevention properties, and can be used in the production of thin woven and knitted fabrics. , Sufficient see-through prevention can be imparted. Further, the heat-shrinkable composite yarn and the composite yarn of the present invention are used for dark-colored clothing and the like because the degree of orientation of the yarn is suppressed, the dyeing property is enhanced, and the deep dyeing property is improved. Can give a sense of luxury.

It is a figure which showed schematically the circumscribed circle diameter (D) and the inscribed circle diameter (d) used for calculating the degree of deformation of the cross section of a single yarn. It is a schematic diagram of the cross-sectional shape of the heat shrinkable composite yarn of this invention. It is a schematic diagram which shows an example of the cross-sectional shape with respect to the longitudinal direction of the highly oriented unstretched hollow multifilament yarn A used in the manufacturing method of this invention. It is a vertical sectional view which shows an example of the fluid swirling nozzle used in this invention. It is a schematic process diagram which shows an example of the manufacturing method of this invention. It is a schematic diagram of the cross-sectional shape of the composite yarn contained in the woven and knitted fabric of this invention. It is a cross-sectional photograph of the heat-shrinkable composite yarn obtained in Example 1 (magnification: 230 times). It is a cross-sectional photograph of the heat-shrinkable composite yarn obtained in Comparative Example 1 (magnification: 230 times).

1. 1. Heat-shrinkable composite yarn The heat-shrinkable composite yarn of the present invention contains a false twist hollow multifilament a and a polyester drawn yarn b, and has a crimp ratio of 5% or less. The false twist hollow multifilament a has a first resin portion containing more than 2% by mass and 10% by mass or less of inorganic oxide fine particles, and a second resin portion containing 2% by mass or less of inorganic oxide fine particles. In the cross-sectional shape of the single yarn constituting the false twist hollow multifilament a, the second resin portion forms a hollow shape including the inner circumference and the outer circumference of the single yarn, and the first resin portion is formed. Formed a multi-leaf shape including 6 to 30 leaf portions radially extending from the center side to the outer peripheral side of the hollow shape in the second resin portion. Further, the false twist hollow multifilament a has a hollow ratio of 3 to 30% and a degree of deformation of 20% or less, the polyester drawn yarn b has an elongation of 15 to 40%, and a boiling water shrinkage ratio of 10 to 25. %. By having such a feature, it is possible to have excellent see-through prevention properties and to suppress a decrease in deep dyeing property even though it contains inorganic oxide fine particles. Hereinafter, the heat-shrinkable composite yarn of the present invention will be described in detail.

[False twist hollow multifilament a]
The single yarn constituting the false twist hollow multifilament yarn a is a hollow yarn including a first resin portion and a second resin portion. Since the false twist hollow multifilament yarn a is false twisted by a swivel nozzle described later, the progress of polyester orientation is suppressed as much as possible, and as a result, the false twist hollow multifilament yarn a has excellent deep dyeing property and the hollow portion is not crushed. It is possible to have excellent see-through prevention.

In the cross section (cross section in the direction perpendicular to the length direction) of the single yarn constituting the false twist hollow multifilament yarn a, the second resin portion is the inner peripheral surface of the single yarn (the boundary of the outer surface of the single yarn). ) And the outer peripheral surface (the boundary of the hollow portion of the single yarn), and the first resin portion radiates from the center side to the outer peripheral side of the hollow shape in the second resin portion 6 It forms a multi-leaf shape including up to 30 leaves. That is, the second resin portion is a resin portion that forms the outer shape of the single yarn constituting the false twist hollow multifilament yarn a, and the first resin portion is embedded in the second resin portion. , The multi-leaf shape is formed. The second resin portion may constitute the entire outer peripheral surface of the cross section of the single yarn, and a part of the outer peripheral surface is formed by the second resin portion (leaf portion) (that is, the leaf portion). A part may be exposed on the outer peripheral surface).

The number of leaf portions formed by the first resin portion is preferably 8 to 25. In the present invention, the leaf portion refers to a shape having a substantially rectangular shape, a substantially elliptical shape, a substantially trapezoidal shape, or the like and having at least one corner curved. Further, the leaf portion formed by the first resin portion may have smooth sides such as a substantially rectangular shape, a substantially elliptical shape, a substantially trapezoidal shape, etc., but for example, a minute convex It may have a portion and / or a recess, or it may be a wavy line. Further, the leaf portions formed by the first resin portion may be connected to each other or may be separated from each other. Further, among the plurality of leaf portions, some of the leaf portions may be connected and the other leaf portions may have a shape separated from each other. The false-twisted hollow multifilament yarn a is a false-twisted “highly oriented unstretched hollow multifilament yarn a” described later, and is basically a first resin portion and a first resin portion of the false-twisted hollow multifilament yarn a. (Ii) The shape of the resin portion follows the shape of the first resin portion and the second resin portion in the highly oriented unstretched hollow multifilament yarn a which is the production raw yarn. That is, the specific shapes of the first resin portion and the second resin portion shown in the column of "highly oriented unstretched hollow multifilament yarn a" described later are basically tentative except for the point of the degree of deformation. It also corresponds to the twisted hollow multifilament yarn a.

The cross section of the single yarn constituting the false twist hollow multifilament yarn a preferably has a rotationally symmetric leaf portion. Here, the rotationally symmetric shape means a shape that overlaps with the original shape when rotated by a constant angle about the center point of the cross section of the single yarn. Since the shape of the leaf portion formed by the first resin portion is rotationally symmetric, the shielding property of the leaf portion, which contributes to the see-through prevention property, is less likely to be biased, and the see-through prevention is uniform at all angles. It becomes easier to obtain sex.

The resin contained in the first resin portion and the second resin portion is polyester. The type of polyester is not particularly limited, but for example, polyalkylene terephthalates such as polyethylene terephthalate (PET), polybutylene terephthalate, and polytrimethylene terephthalate; and biomass-derived monomers such as polybutylene succinate (PBS) are chemically polymerized. Biomass polymer and the like.

The polyester is an aromatic dicarboxylic acid such as isophthalic acid or 5-sulfoisophthalic acid, if necessary, based on melt viscosity, thermal properties, compatibility, etc .; adipic acid, succinic acid, suberic acid, sebacic acid. , An aliphatic dicarboxylic acid such as dodecanedioic acid; an aliphatic diol such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol; glycolic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxycaproic acid. , Hydroxycarboxylic acids such as hydroxypentanoic acid, hydroxyheptanic acid, hydroxyoctanoic acid; and aliphatic lactones such as ε-caprolactone may be polymerized.

The polyesters used in the first resin portion and the second resin portion may be the same or different from each other. When the polyesters used for the first resin portion and the second resin portion are different from each other, it is preferable that the polyesters have excellent compatibility with each other. In the case where the first resin part and the second resin part are subjected to a physical impact or a thermal impact in the silk reeling process or the weaving process by using the combination of polyesters having excellent compatibility in this way. However, it becomes difficult to peel off.

In the present invention, the inorganic oxide fine particles are preferably those having a high sunlight shielding effect, and examples thereof include fine particles such as titanium oxide, calcium oxide, magnesium oxide, and zinc oxide. Of these, titanium oxide fine particles are preferable. The inorganic oxide fine particles used in the first resin portion and the second resin portion may be the same or different from each other.

The particle size of the inorganic oxide fine particles may be fine enough to be dispersed in the first resin portion and the second resin portion.

In the first resin portion, the content of the inorganic oxide fine particles is more than 2% by mass and 10% by mass or less. By satisfying such a content, in combination with the shape of the first resin portion described above, excellent see-through prevention property can be obtained, and further excellent UV protection property can be provided. Further, by satisfying such a content, the spinning operability is also improved. The content of the inorganic oxide fine particles in the first resin portion is preferably 5% by mass or more and 8% by mass or less.

In the second resin portion, the content of the inorganic oxide fine particles is 2% by mass or less. By satisfying such a content, it is possible to improve the spinnability, the silk-reeling process, and the process-passability in the weaving and knitting process while providing the see-through prevention property. From the viewpoint of suitably achieving both see-through prevention and process passability, the content of the inorganic oxide fine particles in the second resin portion is preferably 0% by mass or more and 1% by mass or less, more preferably more than 0% by mass and 0. .5% by mass or less can be mentioned.

Further, in the first resin part and / or the second resin part, in addition to the inorganic oxide fine particles, if necessary, a stabilizer such as an antioxidant, a fluorescent agent, a pigment, an antibacterial agent, and a deodorant can be used. Agents, matting agents, strengthening agents and the like may be contained.

In the single yarn constituting the false twist hollow multifilament yarn a, the mass ratio between the first resin portion and the second resin portion (first resin portion / second resin portion) is not particularly limited. For example, 30/70 to 90/10, preferably 60/40 to 80/20 can be mentioned.

When the mass ratio (first resin portion / second resin portion) is 30/70 or more, the see-through prevention property and the ultraviolet ray protection property can be further improved. On the other hand, when the mass ratio is 90/10 or less, the process passability is further improved. In particular, when the mass ratio (first resin portion / second resin portion) satisfies 60/40 to 80/20, the see-through prevention property, the ultraviolet ray protection property, and the process passability are remarkably improved. Can be done.

The false twist hollow multifilament yarn a has a hollow ratio of 3 to 30% of the constituent single yarns. By maintaining the single yarn hollowness ratio and satisfying the degree of deformation described later in this way, it is possible to provide excellent see-through prevention and realize light weight. Further, when the hollow ratio is 10% or more, the yarn has the same fineness and the same number of filaments, and has bulkiness. From the viewpoint of further improving the see-through prevention property and the lightness, the hollow ratio is preferably 5 to 25%, more preferably 10 to 25%.

In the present invention, the hollow ratio is a value obtained according to the following measuring method. A cross-sectional photograph of the false twisted hollow multifilament yarn a in the direction perpendicular to the longitudinal direction of the single fiber was taken at a magnification of 345 times using an optical microscope, and the entire area and the hollow portion were subjected to image processing from this cross-sectional photograph. The area is measured, and the ratio of the area of the hollow portion to the total area is calculated as the hollow ratio (%). In the present invention, the hollow ratio is a value obtained by collecting 20 single yarns from false twisted hollow multifilament yarns and taking an average value thereof.

The single yarn constituting the false twist hollow multifilament yarn a has a degree of deformation of 20% or less. When the degree of deformation is 20% or less, the degree of crushing of the single yarn is small, that is, the hollow portion of the single yarn is sufficiently held. From the viewpoint of further improving the see-through prevention property, the degree of deformation is preferably 15% or less, more preferably 2 to 10%.

In the present invention, the degree of deformation is a value obtained according to the following measuring method. First, the cross section of the single yarn of the false twist hollow multifilament yarn a is magnified 580 times. From the obtained enlarged photograph, the diameter of the perfect circle circumscribing the cross section of the single yarn is determined as the circumscribed circle diameter (D), and the diameter of the perfect circle inscribed in the cross section is determined as the inscribed circle diameter (d). FIG. 1 shows a diagram schematically showing the circumscribed circle diameter (D) and the inscribed circle diameter (d). In FIG. 1, the hollow portion is omitted for convenience. From the values of the circumscribed circle diameter (D) and the inscribed circle diameter (d), the degree of deformation is calculated according to the following formula. In the present invention, the degree of deformation is a value obtained by collecting 20 single yarns from false twisted hollow multifilament yarns and taking an average value thereof.
Deformity (%) = (1-d / D) x 100

The elongation of the false twist hollow multifilament yarn a is not particularly limited, and examples thereof include 100 to 180%, preferably 120 to 160%. When the elongation is in this range, the degree of orientation of the yarn can be suppressed, and as a result, the dyeability is enhanced and the deep dyeability can be further improved. The elongation of the false twist hollow multifilament yarn a is based on JIS L1013 8.5.1, and a tensile test is performed under the conditions of a sample length of 200 mm and a tensile speed of 200 mm / min using a constant speed elongation type tensile tester. It is a value obtained by doing.

The single yarn fineness of the false twist hollow multifilament yarn a is not particularly limited, but is, for example, 0.5 to 5.0 dtex, preferably 0.8 to 4.0 dtex, and more preferably 1.0 to 3.0 dtex. Can be mentioned. The number of single yarns of the false twist hollow multifilament yarn a is also not particularly limited, but is preferably large for the purpose of enhancing the see-through prevention property, and examples thereof include 10 to 200 yarns, preferably 20 to 100 yarns.

[Polyester drawn yarn b]
The polyester drawn yarn b has an elongation of 15 to 40%. By satisfying such elongation, the physical properties are stabilized even if tension is inevitably applied in the post-processing after weaving and knitting (for example, a series of processing including dyeing processing) in the manufacturing process of the woven and knitted material. It is possible to suppress troubles in terms of quality and quality of woven and knitted fabrics. The elongation of the polyester drawn yarn b is preferably 20 to 35%. The method for measuring the elongation of the polyester drawn yarn b is the same as that of the false twist hollow multifilament yarn a.

Further, the boiling water shrinkage rate of the polyester drawn yarn b is 10 to 25%. When such a boiling water shrinkage rate is satisfied, it becomes possible to impart an excellent elasticity and a texture that does not become too hard to the produced woven or knitted fabric by the shrinkage after the hot water shrinkage treatment described later. The boiling water shrinkage rate of the polyester drawn yarn b is preferably 12 to 23%. In the present invention, the boiling water shrinkage rate of the polyester drawn yarn b is a condition of immersing the polyester drawn yarn b in hot water at 100 ° C. for 30 minutes under the “skein dimensional change rate (method A)” specified in JIS L1013 8.18.1. It is the skein dimensional change rate measured by. The same applies to the method for measuring the boiling water shrinkage rate of the polyester highly oriented undrawn yarn B described later.

The total fineness of the polyester drawn yarn b is not particularly limited, and examples thereof include 20 to 70 dtex, preferably 30 to 45 dtex. The number of single yarns of the polyester drawn yarn b is also not particularly limited, and examples thereof include 6 to 36 yarns, preferably 12 to 24 yarns.

[Heat shrinkable composite yarn]
The heat-shrinkable composite yarn of the present invention is a composite yarn containing the false twist hollow multifilament a and the polyester drawn yarn b.

In the heat-shrinkable composite yarn of the present invention, the mass ratio (a / b) of the false twist hollow multifilament a and the polyester drawn yarn b is not particularly limited, but is, for example, 95/5 to 65/35, preferably 95/5 to 65/35. 85/15 to 75/25 can be mentioned. When the mass ratio is in this range, the see-through prevention property and the texture can be further improved.

The heat-shrinkable composite yarn of the present invention has a crimp ratio of 5% or less. When the crimp ratio is 5% or less, the twisting phenomenon of the polyester filament yarn is weakened, the structural change inside the fiber (for example, morphological strain) is small, and the cross-sectional deformation is gentle. The hollow portion of the filament a is maintained without being crushed, and the progress of the orientation of the false twisted hollow multifilament a is suppressed as much as possible, so that excellent deep dyeability can be realized. The crimp ratio of the heat-shrinkable composite yarn of the present invention is preferably 1.0 to 2.5%, more preferably 1.5 to 2.5%.

In the present invention, the crimp ratio of the heat-shrinkable composite yarn is a value obtained by measuring by the following method. First, the heat-shrinkable composite yarn is removed by a measuring machine having a frame circumference of 1.125 m with 5 turns, and then the skein is hung on a stand at room temperature free of charge all day and night. Next, the skein is put into boiling water with a load of 0.000147 cN / dtex applied and subjected to a wet heat treatment for 30 minutes. Then, take out the skein, lightly remove the water with a filter paper, and leave it in a free state at room temperature for 30 minutes. Then, a load of 0.000147 cN / dtex and 0.00177 cN / dtex (light load) are applied to the skein, and the length X is measured. Subsequently, while the load of 0.000147 cN / dtex is still applied, a load of 0.044 cN / dtex (heavy load) is applied instead of the light load, and the length Y is measured. Then, it is calculated based on the formula of crimp ratio (%) = (YX) / Y × 100. The crimp ratio is measured for five heat-shrinkable composite yarns, and the average of each is taken as the crimp ratio of the yarn.

The torque of the heat-shrinkable composite yarn of the present invention is not particularly limited, and for example, the torque required under the following measurement conditions is 45 T / M or more, preferably 50 T / M or more, and more preferably 55 or more. .. When the torque is 45 T / M or more, the twisting phenomenon of the polyester filament yarn is weakened, the structural change (for example, morphological strain) inside the fiber is small, and the cross-sectional deformation is gentle. The hollow portion of the filament a is easily maintained without being crushed, the progress of orientation is suppressed as much as possible, and the deep dyeability can be further improved. Further, the higher the torque, the greater the effect of twisting and the more excellent the focusing property can be produced.
<Torque measurement conditions>
First, the heat-shrinkable composite yarn 200 cm is hung in a U shape with a pin as a fulcrum (arranged so that both ends of the heat-shrinkable composite yarn are at the top and the pin serving as the fulcrum is at the bottom). An initial load of 0.33 cN / dtex is applied to both upper ends of the heat-shrinkable composite yarn to fix them. After applying a load of 0.003 cN / dtex to the heat-shrinkable composite yarn portion of the pin serving as the fulcrum, the pin is removed and the pin is self-turned in a suspended state. When the self-turning stops, the twist is checked, the number of turns is obtained, and the number of twists per meter is calculated as torque (T / M).

[Manufacturing method of heat-shrinkable composite yarn]
The method for producing a heat-shrinkable composite yarn of the present invention includes the following steps (a) to (c).
(A) A step of preparing a highly oriented unstretched hollow multifilament yarn a satisfying the following (1) to (3) and a polyester drawn yarn b having an elongation of 15 to 40% and a boiling water shrinkage rate of 10 to 25%. 1) It has a first resin portion containing more than 2% by mass of inorganic oxide fine particles and 10% by mass or less and polyester, and a second resin portion containing 2% by mass or less of inorganic oxide fine particles and polyester.
(2) Structure In the cross section of the single yarn, the second resin portion forms a hollow shape including the inner peripheral surface and the outer peripheral surface of the single yarn, and the first resin portion is the second resin portion. Inside, a multi-leaf shape including 6 to 30 leaves radiating from the center side to the outer peripheral side of the hollow shape is formed, and the leaf portion formed by the first resin portion is the outer circumference of the single yarn. It may form a part of the surface.
(3) The single yarn has a hollow portion and has a hollow ratio of 3 to 30%.
(B) Using a fluid swirling nozzle, the highly oriented unstretched hollow multifilament yarn a has a false twist coefficient of 20000 or less, a draw ratio of 1.1 times or less, and a tension ratio of twisting / untwisting of 1.0 to 1. Step of obtaining false-twisted hollow multifilament yarn a by subjecting false twisting at 25 (c) The false-twisted hollow multifilament yarn a and the polyester drawn yarn b are combined by fluid injection processing and heat-shrinkable. Step to obtain composite yarn

Hereinafter, the method for producing the heat-shrinkable composite yarn of the present invention will be specifically described for each step.

[Process (a)]
In step (a), a highly oriented undrawn hollow multifilament yarn a and a polyester drawn yarn b are prepared.

(Highly oriented unstretched hollow multifilament yarn a)
In the method for producing a heat-shrinkable composite yarn of the present invention, the highly oriented unstretched hollow multifilament yarn a becomes a false twisted hollow multifilament a after production. The highly oriented unstretched hollow multifilament yarn a contains a first resin portion containing more than 2% by mass of inorganic oxide fine particles and 10% by mass or less and polyester, and a second resin portion containing 2% by mass or less of inorganic oxide fine particles and polyester. It has a resin part of. Regarding the types and contents of the inorganic oxide fine particles and polyester used in the first resin portion and the second resin portion of the highly oriented unstretched hollow multifilament yarn a, and other components that can be contained as needed. , The same as in the case of the false twist hollow multifilament a.

In the cross section of the constituent single yarn of the highly oriented unstretched hollow multifilament yarn a, the second resin portion is the outer peripheral surface (boundary of the outer surface of the single yarn) and the inner peripheral surface (hollow of the single yarn) of the constituent single yarn. A hollow shape including the boundary of the portion) is formed, and the first resin portion has 6 to 30 leaves radially extending from the center side to the outer peripheral side of the hollow shape in the second resin portion. It forms a multi-leaf shape including. That is, the constituent single yarn of the highly oriented unstretched hollow multifilament yarn a has the outer shape of the constituent single yarn of the false twisted hollow multifilament yarn a in the second resin portion, as in the case of the false twisted hollow multifilament yarn a. The first resin portion is embedded in the second resin portion to form the multi-leaf shape. The second resin portion may constitute the entire outer peripheral surface of the constituent single yarn, and a part of the outer peripheral surface of the constituent single yarn is formed by the second resin portion (that is, a part of the leaf portion). May be exposed on the outer peripheral surface). As described above, since the cross section of the constituent single yarn of the highly oriented unstretched hollow multifilament yarn a is a multi-leaf shape including 6 to 30 leaves, the false twisted hollow multi in the obtained heat-shrinkable composite yarn is obtained. Even in the filament a, the distance between the leaf portions adjacent to each other can be reduced.

The number of leaf portions formed by the first resin portion is preferably 8 to 25. In the present invention, the shape of the leaf portion is as described in the column of false twist hollow multifilament a.

Configuration of Highly Oriented Unstretched Hollow Multifilament Thread a Specifically, the cross-sectional shape shown in FIG. 3 is exemplified as the cross-sectional shape of the single yarn. As illustrated in FIGS. 3A to 3D, the first resin portion forms a leaf portion radially extending from the center side to the outer peripheral side of the single yarn, but the leaf portion (first resin) is formed. They may exist separately in the second resin portion (for example, FIGS. 3 (a), (c) and (d)), or may be connected to each other in the second resin portion (for example). For example, FIG. 3 (b). Further, a part of 6 to 30 leaves may be connected and the rest may be separated by a second resin part.

Structure of Highly Oriented Unstretched Hollow Multifilament Thread a It is preferable that the cross section of the single yarn has a rotationally symmetric leaf portion. Here, the rotationally symmetric shape means a shape that overlaps with the original shape when rotated by a constant angle about the center point of the cross section of the single yarn. Since the shape of the leaf portion formed by the first resin portion is rotationally symmetric, the single yarn spun from the spinning nozzle exhibits a so-called yarn bending phenomenon, and stable spinnability or good yarn quality can be obtained. The problem of not being able to obtain it is less likely to occur. In addition, the shielding property of the leaf portion, which contributes to the see-through prevention property, is less likely to be biased, and it becomes easy to obtain a uniform see-through prevention property at all angles.

When the leaf portions formed by the first resin portion are separated from each other, the shortest distance between the adjacent leaf portions is preferably 0.1 to 2.0 μm, preferably 0.3 to 1 It is more preferably 9.0 μm. Since the leaves formed by the first resin part are independently present so as to satisfy such the shortest interval, the sunlight incident on one of the leaves and diffusely reflected is further applied to the adjacent leaves. It is presumed that diffuse reflection is likely to be repeated, and in combination with the effect of providing the hollow portion, the see-through prevention property can be further improved.

Further, it is preferable that the tip portion on the outer peripheral side of the leaf portion has a curved shape. Since the tip portion has a curved shape, it is possible to further improve the see-through prevention property when the knitted fabric is woven and knitted. It is presumed that such an effect is caused by the sunlight incident on the false twist hollow multifilament a in the obtained heat-shrinkable composite yarn causing diffuse reflection by the tip of the leaf portion having a curved shape.

Structure of Highly Oriented Unstretched Hollow Multifilament Thread a In the cross section of the single yarn, the outer peripheral surface of the single yarn may be entirely formed by the second resin portion, but a part of the outer peripheral surface of the single yarn is the first. It may be formed of one resin portion and the rest may be formed of a second resin portion. When a part of the outer peripheral surface of the single yarn is formed by the first resin portion (that is, the first resin portion is exposed on a part of the outer peripheral surface of the single yarn), the outer peripheral length (μm) of the single yarn is increased. The ratio (EC) of the exposure length (length of the outer peripheral portion formed by the first resin portion) (μm) to the outer peripheral surface of the single yarn of the first resin portion may be 10% or less. It is preferably 5% or less, and more preferably 5% or less. By setting the ratio (EC) to 10% or less, it is possible to improve the spinning operability, the process passability in the silk reeling process and the weaving and knitting process.

In the cross section of the constituent single yarn of the highly oriented unstretched hollow multifilament yarn a, the distance (μm) from the center of the constituent single yarn (center point of the hollow portion) to the outer circumference (μm) is from the outer circumference of the constituent single yarn to the end of the leaf portion. The average value of the ratio (DC) of the shortest distance (μm) to the portion is preferably 10% or less, and more preferably 5% or less. When the average ratio (DC) is 10% or less, the region of the second resin portion existing from the leaf portion to the outer peripheral surface of the single yarn becomes smaller in the region of the second resin portion, and this region is exposed to sunlight. Becomes difficult to penetrate. As a result, the amount of sunlight transmitted through this region is reduced, so that the see-through prevention property can be further improved and the ultraviolet ray protection property can be improved. Here, the average value of the ratio (DC) is a value obtained by obtaining the ratio (DC) for all the leaves existing in the cross section of the constituent single yarn and calculating the average value.

The ratio (EC) and the average ratio (DC) can be controlled by appropriately adjusting spinning conditions such as the shape of the spinning nozzle, the viscosity of the synthetic resin, and the spinning temperature.

Structure of Highly Oriented Unstretched Hollow Multifilament Thread a The outer peripheral shape of the cross section of the single yarn is a substantially perfect circle, and the degree of deformation is usually 3% or less. Structure of Highly Oriented Unstretched Hollow Multifilament Thread a The method for measuring the degree of deformation of the single yarn is the same as that for the false twisted hollow multifilament a.

Composition of Highly Oriented Unstretched Hollow Multifilament Thread a The single yarn has a hollow portion, and the hollow ratio thereof needs to be 3 to 30%, preferably 7 to 25%, more preferably 12 to 25%. Is. Further, the hollow portion is preferably arranged at the center of the single yarn from the viewpoint of spinning operability or uniform sheer prevention. Structure of Highly Oriented Unstretched Hollow Multifilament Thread a The method for measuring the hollowness of a single yarn is the same as that of the false twisted hollow multifilament a.

Structure of Highly Oriented Unstretched Hollow Multifilament Thread a The cross section of the single yarn is provided with a specific hollow portion in addition to the multi-leaf shape formed by the first resin portion as described above. As a result, the false twist hollow multifilament a in the obtained heat-shrinkable composite yarn is prevented from see-through as compared with the conventional concentric composite fiber, the linear split type fiber, or the composite fiber having no hollow portion. The property is improved, and excellent coolness and UV protection can be imparted. This is because the refractive index of the air layer contained in the hollow portion differs from the refractive index of the first resin portion and / or the second resin portion by further providing the hollow portion. It is presumed that this is due to the synergistic effect caused by the refraction of sunlight incident on the yarn in the hollow portion.

Composition of Highly Oriented Unstretched Hollow Multifilament Thread a When the hollow ratio of the single yarn is less than 10%, the hollow portion occupying the cross section of the single yarn is small, so that the air layer and the first resin portion and / or the second The effect due to the difference in refractive index from the resin portion may not be sufficiently exhibited, and the see-through prevention property may be insufficient. Further, if the hollow ratio exceeds 30%, the hollow portion disappears due to crushing in the silk reeling process or the post-processing process, or fibrillation or whitening occurs due to peeling of the hollow portion, which is not preferable.

The elongation of the highly oriented unstretched hollow multifilament yarn a is particularly limited, and examples thereof include 100 to 180%, preferably 120 to 160%. If the elongation is less than 100%, yarn breakage may occur frequently in the false twisting step described later. On the other hand, even if an attempt is made to obtain a highly oriented undrawn yarn exceeding 180%, there is a tendency that yarn breakage, quality deterioration, etc. occur during manufacturing, making stable supply difficult. The method for measuring the elongation of the highly oriented unstretched hollow multifilament yarn a is the same as that of the false twisted hollow multifilament yarn a.

The composition of the highly oriented unstretched hollow multifilament yarn a The mass ratio of the first resin portion to the second resin portion (first resin portion / second resin portion) is not particularly limited in the single yarn. For example, 30/70 to 90/10, preferably 60/40 to 80/20.

Examples of the single yarn fineness of the highly oriented unstretched hollow multifilament yarn a include 0.5 to 5.0 dtex, preferably 0.8 to 4.0 dtex.

The number of single yarns of the highly oriented unstretched hollow multifilament yarn a is the same as that of the false twisted hollow multifilament yarn a.

The highly oriented unstretched hollow multifilament yarn a can be obtained by a known production method.

(Polyester drawn yarn b)
In the method for producing a heat-shrinkable composite yarn of the present invention, the polyester drawn yarn b prepared in the step (a) becomes the polyester drawn yarn b contained in the heat-shrinkable composite yarn as it is. That is, the configuration of the polyester drawn yarn b prepared in the step (a) is as described above.

[Process (b)]
In step (b), the highly oriented unstretched hollow multifilament yarn a is subjected to a false twist coefficient of 20000 or less, a draw ratio of 1.1 times or less, and a tension ratio of twisting / untwisting of 1.0 by using a fluid swirling nozzle. False twisting is performed at 1.25 to obtain false twisted hollow multifilament yarn a.

Generally, a drawing simultaneous false twisting method is adopted as a method for obtaining false twisted yarn from a highly oriented undrawn multifilament yarn. The spindle method and the friction method are generally adopted as the false twist method in this simultaneous draw and false twist processing method, but if the draw ratio is lowered in either method, the operability such as yarn breakage and untwisted state due to ballooning is affected. Therefore, a certain degree of draw ratio and processing tension are required.

Therefore, when the highly oriented unstretched hollow multifilament yarn a having a hollow portion is processed by the drawing simultaneous false twisting method, it is necessary to give twist at the same time as drawing at the time of false twisting, so that the single yarn form is liable to collapse. The single yarn hollow portion of the highly oriented unstretched hollow multifilament yarn a also loses its single yarn morphology and becomes easily crushed. Further, in the simultaneous drawing false twisting method, a certain degree of stretching ratio and processing tension are required, so that the orientation is promoted and the deep dyeability is inferior.

In the present invention, the false twist coefficient is 20000 or less, the draw ratio is 1.1 or less, and the untwisting / twisting tension ratio is 1.0 to 1.25 for the highly oriented unstretched hollow multifilament a using a fluid swirling nozzle. By false twisting under the false twisting conditions of the above, a composite yarn containing the false twist hollow multifilament yarn a holding the hollow portion can be obtained. As the fluid swirling nozzle, for example, the fluid swirling nozzle described in FIG. 9 of JP-A-4-214431 can be used.

By false twisting under the above conditions, the highly oriented unstretched hollow multifilament yarn a is twisted, the untwisting tension is set to a stress value of 0.05 to 0.15 g / d or less, and the yarn is temporarily twisted without being substantially stretched. Can be twisted. In addition, since processing with a false twist coefficient of 20000 or less is possible, the twisting action of the fiber due to twisting can be suppressed. That is, since the stress applied to the yarn form due to stretching and twisting during false twisting can be suppressed, the false twisted hollow multifilament yarn a holding the hollow portion can be obtained. In a normal false twist process using a friction method or the like, the hollow portion of the highly oriented unstretched hollow multifilament a is crushed and has poor permeability, resulting in a thick woven or knitted fabric.

In the false twist processing conditions in the step (b), the false twist coefficient is 20,000 or less, preferably 15,000 or less, and more preferably 10,000 or less. When the false twist coefficient exceeds 20000, the twisting action of the fiber due to twisting becomes strong, the single yarn morphology changes, and the single yarn hollow portion is easily crushed, which is not preferable. The false twist coefficient is calculated by the following formula using the false twist number (unit: T / M) and the yarn fineness T (unit: denier).
False twist coefficient = false twist number x T ^1/2

Under the false twisting conditions in step (b), the draw ratio is preferably 1.1 or less. If the draw ratio exceeds 1.1, the single yarn morphology changes and the single yarn hollow portion is easily crushed, which is not preferable.

Under the false twisting conditions in the step (b), the untwisting / twisting tension ratio is 1.0 to 1.25, preferably 1.0 to 1.1. When the tension ratio is within the above range, the structural change inside the fiber caused by the tension difference between the twisting point and the untwisting point of the running yarn can be minimized. The twisting tension and untwisting tension are preferably 0.05 to 0.15 g / d, preferably 0.05 to 0.125 g / d.

Under the false twisting conditions in step (b), the heater temperature during false twisting may be adopted in the range of 200 to 320 ° C, preferably 220 to 300 ° C, at which undrawn yarn does not cause fusion. In order to further enhance the shrinkage characteristics, a high temperature within the above range is preferable.

Further, by using the fluid swirling nozzle, the stretching of the highly oriented unstretched hollow multifilament yarn a can be suppressed, and the degree of orientation of the polyester can be suppressed from being excessively advanced.

An example of the fluid swirling nozzle is shown in FIG. In FIG. 4, the compressed fluid is ejected from the air supply port 17 in the tangential direction of the thread supply port 16 to twist the running yarn. Here, in order to set the twisting / untwisting tension ratio described above to 1.0 to 1.25, the air supply port 17 is provided so as to be substantially perpendicular to the thread supply port 16 to supply the yarn. The diameters of the thread inlet side and the thread outlet side of the mouth 16 may be equal or widened in a tapered shape from the thread outlet side toward the thread inlet side. The reason why the twisting tension is set to be equal to or slightly lower than the untwisting tension is that the traveling yarn minimizes the structural change inside the fiber caused by the tension difference between the twisting point and the untwisting point.

[Process (c)]
In the step (c), the false twist hollow multifilament yarn a and the polyester drawn yarn b are combined by fluid injection processing to obtain a heat-shrinkable composite yarn.

Examples of the fluid injection method include a method of entwining fibers by adopting interlacing or Taslan processing.

As a condition for fluid injection processing, it is preferable that the overfeed rate is 1.0 to 3.0%. Further, it is preferable that the air pressure is 1.5 to 5.0 kg / cm ² .

The elongation of the false twist hollow multifilament yarn a obtained in the step (b) is as high as 100 to 180%, but in the step (c), the polyester drawn yarn b having an elongation of 40% or less and the fluid injection process are used. By using the composite yarn, a heat-shrinkable composite yarn having a low elongation as a whole yarn can be obtained.

[Specific embodiments of steps (b) and (c)]
Next, in the method for producing a heat-shrinkable composite yarn of the present invention, specific embodiments of the steps (b) and (c) will be described in detail with reference to the schematic process diagram of FIG.

First, the packages YA and YB of the above-mentioned highly oriented undrawn yarn hollow multifilament yarn a and polyester drawn yarn b are set on the creel, respectively.

Next, the polyester drawn yarn b is introduced into the first supply roller 6 and pulled out from the first take-up roller 11. The draw ratio at this time is preferably about 0.98 to 1.02 times. Here, the draw ratio is the ratio of the surface speed of the first supply roller 6 to the surface speed of the first take-up roller 11 (stretch ratio = surface speed of the first take-up roller 11 / surface speed of the first take-up roller 6). To say. When the draw ratio of the polyester drawn yarn b is less than 0.98 times, slack occurs in the polyester drawn yarn b between the first supply roller 6 and the first take-up roller 11 during yarn processing, and the yarn is wound around the rollers. It can cause thread breakage. On the other hand, if the draw ratio exceeds 1.02 times, the yarn physical characteristics such as the fineness and elongation of the polyester drawn yarn b may change.

Here, the polyester drawn yarn b may be used instead of the polyester highly oriented undrawn yarn that can obtain the same yarn physical characteristics. In that case, a drawing step of drawing the polyester highly oriented undrawn yarn is performed between the first supply roller 6 and the first take-up roller 11 while applying heat with a heater to obtain a drawn yarn equivalent to the polyester drawn yarn b. obtain. As the drawing conditions at this time, for example, a polyester highly oriented undrawn yarn having a total fineness of 54.3 dtex, 12 filaments and an elongation of 115.4% was prepared, and the heater temperature was 260 ° C. and the drawing magnification was 1.60 times. By heat stretching, a polyester drawn yarn b having a total fineness of 33.9 dtex, an elongation of 31.0%, and a boiling water shrinkage rate of 22.8% can be obtained.

Next, a false twisting step of false twisting the highly oriented unstretched hollow multifilament yarn a with a fluid swirling nozzle is performed under predetermined conditions. That is, the highly oriented unstretched hollow multifilament yarn a is false twisted under false twist conditions of a false twist coefficient of 20000 or less, a draw ratio of 1.1 or less, and a untwisting / twisting tension ratio of 1.0 to 1.25. Specifically, as shown in FIG. 5, the highly oriented unstretched hollow multifilament yarn a is introduced into the second supply roller 7, passes through the heater 8, the cooling plate 9, and the fluid swirling nozzle 10, and then the second take-up roller 13. By pulling out from, a false twist hollow multifilament yarn a is obtained. Here, the false twist region is between the second supply roller 7 and the first take-up roller 11 in FIG. Specifically, the area between the second supply roller 7 and the fluid swirling nozzle 10 is the twisting area T1, and the area between the fluid swirling nozzle 10 and the first take-up roller 11 is the untwisting area T2.

The processing speed of the false twisting step is preferably 200 to 700 m / min, and it is preferable to specify the processing speed, the draw ratio, and the like. The processing speed refers to the yarn speed when the yarn is pulled out from the first take-up roller 11, that is, the surface speed of the first take-up roller 11.

In the false twisting step, the draw ratio is preferably 1.1 times or less. Here, the draw ratio in the false twisting step is the ratio of the surface speed of the second supply roller 7 to the surface speed of the first take-up roller 11 (stretch ratio = surface speed of the first take-up roller 11 / second supply roller 7). Surface velocity). If the draw ratio exceeds 1.1, the single yarn morphology changes and the single yarn hollow portion is easily crushed, which is not preferable.

After the false twisting step, the false twist hollow multifilament yarn a is aligned with the polyester drawn yarn b and guided to the interlaced nozzle 12, and the air pressure is 1.0 to 7.0 kg / cm ² using the interlaced nozzle 12, which is over. The mixed fibers are entangled under the condition that the feed rate is 1.0 to 5.0% to obtain a heat-shrinkable composite yarn. The overfeed rate is the overfeed rate = (V1-V2) / V2 × 100 (%) when the thread speed immediately before being introduced into the interlaced nozzle is V1 and the thread speed immediately after passing through the interlaced nozzle is V2. It is calculated by the formula. In the case of FIG. 5, it is calculated by the formula: overfeed rate = (surface speed of the first take-up roller 11-surface speed of the second take-up roller 13) / surface speed of the second take-up roller 8 × 100 (%). ..

After passing through the second take-up roller 13, the heat-shrinkable composite yarn is wound up on the package 15 by the take-up roller 14. As a guide, the heat-shrinkable composite yarn can be said to have an appropriate mixed fiber entanglement when the number of entanglements is in the range of about 20 to 150 pieces / m.

2. 2. Composite yarn The composite yarn of the present invention contains the above-mentioned false twist hollow multifilament a and polyester fiber B. The composite yarn of the present invention is obtained by subjecting the heat-shrinkable composite yarn to, for example, heat-shrinking to shrink the polyester drawn yarn b, and the polyester drawn yarn b is made of polyester after heat-shrinking. It becomes fiber B. As shown in FIG. 6, in the composite yarn of the present invention, the false twist hollow multifilament a is arranged on the sheath side and the polyester fiber B is arranged on the core side. The false twisted hollow multifilament a, which contributes to see-through resistance, is arranged on the sheath side relatively, so that it has excellent see-through resistance, and the polyester fiber B exhibits sufficient shrinkage, so that it is woven. Even if it is thin when knitted, it has an excellent texture.

In the composite yarn of the present invention, the structure of the false twist hollow multifilament a is the same as that of the false twist hollow multifilament a in the heat shrinkable composite yarn.

The polyester fiber B is in a state in which the polyester drawn yarn b is sufficiently shrunk by the heat shrinkage treatment.

The single yarn fineness of the polyester fiber B is not particularly limited, and examples thereof include 1.0 to 5.0 dtex, preferably 1.5 to 4.5 dtex. The total fineness of the polyester fiber B is not particularly limited, and examples thereof include 20 to 100 dtex, preferably 30 to 90 dtex. The number of single yarns of the polyester fiber B is the same as that of the polyester drawn yarn b in the heat-shrinkable composite yarn.

In the composite yarn, the mass ratio (a / B) of the false twist hollow multifilament a and the polyester fiber B is not particularly limited, but is, for example, 95/5 to 65/35, preferably 85/15 to 75/25. Can be mentioned.

The crimp ratio of the composite yarn of the present invention is 5% or less, preferably 1.0 to 2.5%, and more preferably 1.5 to 2.5%. When the crimp ratio is 5% or less, the twisting phenomenon of the polyester filament yarn is weakened, the structural change inside the fiber (for example, morphological strain) is small, and the cross-sectional deformation is gentle, so that the hollow portion is not crushed. While being maintained, the progress of polyester orientation is suppressed as much as possible, and excellent deep dyeability can be realized.

The torque of the composite yarn of the present invention is not particularly limited, and examples thereof include a torque of 45 T / M or more, preferably 50 T / M or more, and more preferably 55 or more, which are obtained under the above-mentioned measurement conditions. When the torque is 45 T / M or more, the twisting phenomenon of the polyester filament yarn is weakened, the structural change (for example, morphological strain) inside the fiber is small, and the cross-sectional deformation is gentle. The hollow portion of the filament a is easily maintained without being crushed, and the progress of the orientation of the polyester is suppressed as much as possible, so that the deep dyeability can be further improved. Further, the higher the torque, the greater the effect of twisting and the more excellent the focusing property can be produced.

The composite yarn of the present invention has excellent deep dyeing property even if it is thin due to the synergistic effect with the deep dyeing property of the false twisted yarn, in addition to the fact that the diffused reflection to the outside is not reduced due to the complicated internal refraction between the filaments. Weaving and knitting can be formed.

The composite yarn of the present invention can be obtained by heat-shrinking the heat-shrinkable composite yarn. By heat-shrinking the heat-shrinkable composite yarn, as shown in FIG. 2, the polyester drawn yarn b located relatively on the sheath side in the heat-shrinkable composite yarn is transferred to the core side, and is shown in FIG. As described above, a composite yarn is obtained in which the false twist hollow multifilament a is relatively arranged on the sheath side and the polyester fiber B is arranged on the core side.

Specific examples of the heat shrinkage treatment include hot water shrinkage treatment. The conditions for the hot water shrinkage treatment may be appropriately set so that the polyester drawn yarn b can be sufficiently shrunk, and examples thereof include 10 to 30 minutes at 80 to 130 ° C.

[Woven knit]
The woven and knitted fabric of the present invention includes the heat-shrinkable composite yarn or the composite yarn. In the woven and knitted fabric of the present invention, the heat-shrinkable composite yarn or the composite yarn may be used for at least a part of the constituent yarns, but from the viewpoint of providing excellent see-through prevention and deep dyeing property, weaving. The amount of the heat-shrinkable composite yarn or the composite yarn used in the knitted fabric is 50% by mass or more, preferably 70% by mass or more, more preferably 80% or more, 90% or more, 95% by mass or more, or 100% by mass. Can be mentioned.

Further, in the woven and knitted fabric of the present invention, the structure of the woven and knitted fabric is not particularly limited, and the structure may be appropriately set according to the intended use. For example, in the case of woven fabrics, plain weave, twill weave, satin weave, and multiple textures may be adopted as needed, and in the case of knitted fabrics, round knitted fabric, smooth, warp knitted tricot, and multipled as necessary. Organization) should be adopted.

The thickness of the woven or knitted fabric of the present invention may be appropriately set according to the intended use, but for example, in the case of a knitted fabric, it is preferably 0.5 mm or less, preferably 0.3 to 0.5 mm. Is even more preferable. Even if the woven or knitted fabric of the present invention is thinned sufficiently in this way, it can have an excellent sheer prevention property and a firm texture.

Further, as one aspect of the woven or knitted fabric of the present invention, the degree of decrease in permeability when wet, which is represented by the following formula (I), is 5.0% or less, preferably 4.5% or less.

In order to satisfy the low excess of permeability at the time of wetting within the above range, the amount of the heat-shrinkable composite yarn or the composite yarn to be used, the heat-shrinkable composite yarn or the false twisted hollow multifilament a in the composite yarn. The mixing ratio, the cover factor of the woven and knitted fabric, and the like may be appropriately adjusted.

The cover factor (CF) of the woven or knitted fabric of the present invention is not particularly limited. For example, in the case of a woven fabric, the CF is 1000 to 3500, preferably 1500 to 2500, and even in the case of a knitted fabric. For example, CF is 500 to 2500, preferably 800 to 1800. When the CF of the woven or knitted fabric of the present invention satisfies the above range, it is possible to further improve the cool feeling property and the ultraviolet ray protection property as well as the remarkably excellent see-through prevention property.

Here, CF is calculated by the following formula (III) in the case of a woven fabric and by the following formula (IV) in the case of a knitted fabric.

The use of the woven and knitted fabric of the present invention is not particularly limited, and examples thereof include uniforms, sportswear, innerwear, and the like, for which transparency is desired even in a thin material.

The woven and knitted fabric of the present invention may be manufactured by weaving and knitting using the composite yarn. Further, the woven and knitted fabric of the present invention may be produced by weaving and knitting using the shrinkable composite yarn to produce a raw machine, and then heat-shrinking the raw machine to produce a woven and knitted fabric containing the composite yarn. good. Further, the woven and knitted fabric of the present invention may be used as a woven and knitted fabric containing the contractile composite yarn without heat-shrinking the knitted fabric woven and knitted using the contractile composite yarn.

In the production of the woven and knitted fabric of the present invention, the shrinkable composite yarn or the composite weaving and knitting may be performed using a known loom or knitting machine, and the preparatory step prior to the weaving and knitting may also be performed by using known equipment. good.

Further, when the raw machine woven and knitted using the shrinkable composite yarn is heat-shrinked, the heat-shrinking treatment is performed by, for example, a hot water shrinking treatment in which the raw machine is immersed in hot water for a predetermined time. b may be sufficiently heat-shrinked. The conditions for the hot water shrinkage treatment include, for example, about 10 to 30 minutes at about 80 to 135 ° C. By such a hot water shrinkage treatment, the polyester drawn yarn b is sufficiently heat-shrinked, and a woven or knitted fabric having excellent see-through prevention property and deep dyeing property can be obtained.

The heat shrinkage treatment may be performed in the scouring process and the dyeing process. The heat shrinkage treatment of this embodiment will be described below with an example. First, refine the raw machine. The refining may be carried out by a continuous method or a batch method at a temperature of 80 to 130 ° C. Usually, it is preferable to carry out by a batch method at 100 ° C. or lower, and it is particularly preferable to carry out by using a high-pressure liquid flow dyeing machine equipped with a jet nozzle. After refining, presetting may be performed if necessary. The preset is usually dry heat treated at 170 ° C. to 200 ° C. for 30 to 120 seconds using a pin tenter. After that, the dyeing process is performed according to a conventional method. The final set may be performed if necessary.

Hereinafter, the present invention will be described in detail by way of examples. However, the present invention is not limited to the following examples.

1. 1. Measurement / Evaluation Method The measurement and evaluation in the following Examples and Comparative Examples were performed according to the following methods.
(1) Extreme viscosity [η]
The measurement was carried out by a conventional method under the condition of a temperature of 20 ° C. using an equal mass mixture of phenol and ethane tetrachloride as a solvent.

(2) Ratio (EC) of the exposure length (μm) of the first resin portion to the single yarn surface with respect to the outer peripheral length (μm) of the single yarn.
The cross section of the single yarn taken out from the highly oriented unstretched hollow multifilament yarn a in the direction perpendicular to the longitudinal direction was observed with an optical microscope (“PCSCOPE PCS-81X” manufactured by INABATA & CO), and the outer circumference length (μm) of the single yarn was observed. , And the exposure length of the first resin portion to the outer peripheral surface of the single yarn (the length of the outer peripheral portion formed by the first resin portion) (μm) was measured, and the ratio (EC) was calculated by the following equation. ..
EC (%) = {Exposure length of the first resin part (μm) / Peripheral length of single yarn (μm)} × 100

(3) Average ratio (DC) of the shortest distance (μm) from the outer circumference of the single yarn to the leaf portion with respect to the distance (μm) from the center of the single yarn to the outer circumference of the single yarn.
Observe the cross section of the single yarn taken out from the highly oriented unstretched hollow multifilament yarn in the direction perpendicular to the longitudinal direction with an optical microscope (INABATA & CO "PCSCOPE PCS-81X"), and the distance from the center of the single yarn to the outer circumference of the single yarn. (Μm) and the shortest distance (μm) from the outer circumference of the single thread to each leaf in each leaf were measured. Then, the average ratio (DC (%)) of the shortest distance (μm) from the outer circumference of the single yarn to each leaf in each leaf portion with respect to the distance (μm) from the center of the single yarn to the outer circumference of the single yarn is calculated by the following equation. bottom.
DC (%) = average value of the shortest distance from the outer circumference of the single yarn to each leaf (μm) / distance from the center of the single yarn to the outer circumference of the single yarn (μm) × 100

(4) The shortest distance (μm) between the leaves adjacent to each other
The cross section of the single yarn taken out from the highly oriented unstretched hollow multifilament yarn in the direction perpendicular to the longitudinal direction was observed with an optical microscope (INABATA & CO "PCSCOPE PCS-81X"), and the adjacent leaves in the separated leaves were observed. The shortest distance (μm) was measured. All the separated leaves in the cross section were measured, and the average value was taken as the shortest distance (μm) between the adjacent leaves.

(5) Hollow rate A cross-sectional photograph of a single fiber of a multifilament yarn in the direction perpendicular to the longitudinal direction is taken at a magnification of 345 times using an optical microscope, and the entire area and hollow portion are processed by image processing from this cross-sectional photograph. The area of the hollow part was calculated with respect to the total area. Twenty single yarns were collected from the multifilament yarns, and the average value of these was calculated.

(6) Degree of Deformity First, the cross section of the single thread of the false twist hollow multifilament thread a was magnified 580 times, and from the obtained enlarged photograph, the diameter of the perfect circle circumscribed to the cross section of the single thread was circumscribed. The diameter (D) and the diameter of the perfect circle inscribed in the cross section were determined as the inscribed circle diameter (d), and the degree of deformation was calculated according to the following formula. Twenty single yarns were collected from the false twist hollow multifilament yarn a, and the average value of these was calculated.
Deformity (%) = (1-d / D) x 100

(7) Shrinkage rate Using a measuring machine with a frame circumference of 1.125 m, the mixed fiber entangled yarn was removed with 5 turns, and then the skein was hung on a stand in a free state at room temperature all day and night. Next, the skein was put into boiling water with a load of 0.000147 cN / dtex applied and subjected to a wet heat treatment for 30 minutes. Then, the skein was taken out, the water was lightly removed with a filter paper, and the mixture was left in a free state at room temperature for 30 minutes. Then, a load of 0.000147 cN / dtex and 0.00177 cN / dtex (light load) were applied to the skein, and the length X was measured. Subsequently, while the load of 0.000147 cN / dtex was still applied, a load of 0.044 cN / dtex (heavy load) was applied instead of the light load, and the length Y was measured. Then, it was calculated based on the formula of crimp ratio (%) = (YX) / Y × 100. The crimp ratio was measured for five mixed entangled yarns, and the average of each was taken as the crimp ratio of the yarn.

(8) Torque First, a heat-shrinkable composite yarn of 200 cm was hung in a U shape with a pin as a fulcrum (arranged so that both ends of the heat-shrinkable composite yarn are at the top and the pin serving as the fulcrum is at the bottom). Next, an initial load of 0.33 cN / dtex was applied to both upper ends of the heat-shrinkable composite yarn to fix them. After applying a load of 0.003 cN / dtex to the heat-shrinkable composite yarn portion of the pin serving as the fulcrum, the pin was removed and self-turned in a suspended state. When the self-turning stopped, the twist was checked, the number of turns was obtained, and the number of twists per meter was calculated as torque (T / M).

(9) Degree of decrease in permeability (TF)
Using a spectrophotometer (“UV-3100PC” manufactured by Shimadzu Corporation), determine the transparency (%) (WId) of the woven and knitted fabric when it is dry and the transparency (%) (WIw) of the woven and knitted fabric when it is wet. , The degree of decrease in permeability was calculated by the following formula. The woven and knitted material at the time of drying was a sample in which the woven and knitted material was allowed to stand for 24 hours in an environment of 20 ° C. and 65% RH. The woven and knitted fabric at the time of wetting is a sample in which the woven and knitted fabric is allowed to stand in an environment of 20 ° C. and 65% RH for 24 hours and then impregnated with the same mass of water as the woven and knitted fabric.
Degree of decrease in permeability (%) when wet = WId-WIw
Transparency (%) = 100- (Difference in L * value when whiteboard and blackboard are placed on the back side of woven and knitted fabric) / (Difference in L * value between whiteboard and blackboard) x 100 (II)

(10) Fineness JIS L 1096: 2010 8.99.1. Measured and calculated according to b.

(11) Thickness of knitted fabric Measured and calculated using a precision thickness measuring instrument (“Peacock” manufactured by Ozaki Seisakusho Co., Ltd.).

(12) L value The L value was measured using a color difference meter (spectrophotometer CE-3100 manufactured by Macbeth).

(13) Texture (feeling of fluffiness (thickness), elasticity)
The woven and knitted fabrics were evaluated according to the following criteria based on the tactile sensation.
◯: There is a feeling of elasticity and there is little feeling of fluffiness.
X: There is a feeling of elasticity, but a feeling of sickness appears.

2. 2. Production of heat-shrinkable composite yarn and knitted fabric (Example 1)
In the first resin portion, as the polyethylene terephthalate, a polyethylene terephthalate having an ultimate viscosity of 0.65, chipped by a conventional method, and dried was used. In the first resin portion, a resin composition containing titanium oxide fine particles (TiO ₂ ) as inorganic oxide fine particles in a proportion of 5% by mass with respect to the polyethylene terephthalate was used. In the second resin portion, as the polyethylene terephthalate, a polyethylene terephthalate having an ultimate viscosity of 0.65, chipped by a conventional method, and dried was used. In the second resin, titanium oxide fine particles (TiO ₂ ) were contained in a proportion of 0.4% by mass with respect to the polyethylene terephthalate.

The mass ratio of the first resin portion to the second resin portion (first resin portion / second resin portion) is 75/25, and the multi-leaf shape (leaf portion) shown in FIG. 3 (c). A multifilament was spun at a spinning temperature of 295 ° C. using a conventional composite spinning apparatus using a nozzle having a number of nozzles (number: 20). Then, the spun multifilament is cooled, an oil agent is applied to the surface thereof, and the spun multifilament is picked up by a take-up roller at a speed of 3000 m / min, and the highly oriented undrawn hollow multifilament yarn a (total fineness: 114.4 dtex, single yarn). The number was 48, the elongation was 146.3%, and the degree of deformation of the outer periphery of the cross section was 3% or less, which was a substantially perfect circle).

On the other hand, a polyester drawn yarn b having an elongation of 25.9%, a single yarn fineness of 1.8 dtex, a total fineness of 32.7 dtex 18 filament, and a heat shrinkage rate of 15.7% was prepared. Then, the highly oriented unstretched hollow multifilament yarn a and the polyester drawn yarn b were subjected to a process for manufacturing a heat-shrinkable composite yarn as shown in FIG. The false twist processing conditions and the fluid injection processing conditions were as follows, and a 148.4 dtex66 filament heat-shrinkable composite yarn was obtained.

<Casual twist processing conditions>
Surface speed of the first supply roller 6: 498.0 m / min Stretch ratio of polyester drawn yarn b: 1.00 times Surface speed of the second supply roller 7: 485.4 m / min Stretching ratio of polyester highly oriented unstretched yarn a : 1.03 times Heater 8 temperature: 285 ° C
Torture tension: 11.3 g
Untwisting tension: 11.7 g
Untwisted / twisted tension ratio (K value): 1.04
Air pressure of fluid swirling nozzle 10: 5.0 kg / cm ²
Swirling direction of fluid swirling nozzle 10: Surface speed of first take-up roller 11 in Z direction: 500 m / min False twist coefficient: 8000
False twist number: 800T / M
<Fluid injection processing conditions>
Interlaced Nozzle 12: Hevaline P-212
Air pressure of interlaced nozzle 12: 3.5 kg / cm ²
Surface speed of the second take-up roller 13: 491.6 m / min Overfeed rate of interlaced zone: 2.0%

The surface speed of the take-up roller 14 was set to 492.5 m / min, and the overfeed rate of the take-up zone was set to 1.5%.

FIG. 7 shows a cross-sectional photograph of the obtained heat-shrinkable composite yarn taken at a magnification of 230 times using an optical microscope (manufactured by Olympus Corporation, trade name “BH2-UMF”). The hollow ratio of the false twist hollow multifilament yarn a in FIG. 7 was 13%, and the degree of deformation was 10%.

Next, a cylinder knitting machine (manufactured by Fukuhara Kogyo) was used to obtain a raw machine in which heat-shrinkable composite yarn was arranged (Tenjiku knitting, 41 wales / 2.54 cm, 42 courses / 2.54 cm). Then, using a BOLOFF smelter (manufactured by Fukushin Kogyo Co., Ltd.), the raw machine was smelted at 80 ° C. for 20 minutes to obtain knitted fabrics, and various evaluations excluding the L value were performed.

Next, a dyeing solution having the composition shown in the following formulation 1 is prepared, and the raw machine is dyed at 135 ° C. for 30 minutes using this dyeing solution, and then the reducing solution having the composition shown in the following formulation 2 is adjusted for dyeing. The ground was reduced at 80 ° C. for 20 minutes.
<Prescription 1>
Dianix Black 15% omf
Nikka Sun Salt SN-130 0.5g / L
Acetic acid 0.2g / L
<Prescription 2>
Hydrosalify 1g / L
Sodium hydroxide 1g / L
Sun Mall FL 1g / L

Then, it was dried at 60 ° C. using a shrink surfer type dryer (manufactured by Hirano Tech Sheet Co., Ltd.), and the L value was measured.

(Examples 2 to 4)
Using the same method as in Example 1, highly oriented unstretched hollow multifilament yarns a having a hollow ratio of 20%, 10%, and 5% were obtained (structures and characteristics other than the hollow ratio are described in Example 1). Similar to the highly oriented unstretched hollow multifilament yarn a used). Using the highly oriented unstretched hollow multifilament yarn a, a knitted fabric was produced under the same conditions as in Example 1.

(Comparative Example 1)
In Example 1, the false twisting process for the highly oriented unstretched hollow multifilament yarn a is changed from the fluid swirling false twisting to the disk false twisting, and the false twisting process and the fluid injection process are executed under the following conditions, and the 110.7 dtex66 filament is executed. The heat-shrinkable composite yarn of the above was obtained.

<Casual twist processing conditions>
Surface speed of the first supply roller 6: 498.0 m / min Stretch ratio of polyester drawn yarn b: 1.00 times Surface speed of the second supply roller 7: 320.5 m / min Stretching ratio of polyester highly oriented unstretched yarn a : 1.56 times Heater 8 temperature (short part / long part): 400 ° C / 220 ° C
Torture tension: 42.0 g
Untwisting tension: 32.0 g
K value (tension ratio of untwisted / twisted): 0.76
Disc configuration: Z-1-6-K
Disk turning direction: Z direction Disk rotation speed: 800 rotations / minute Surface speed of the first take-up roller 11: 500 m / minute <Fluid injection processing conditions>
Interlaced Nozzle 12: Hevaline P-102
Air pressure of interlaced nozzle 12: 3.5 kg / cm ²
Surface speed of the second take-up roller 13: 491.5 m / min Overfeed rate in the interlaced zone: 1.7%

The surface speed of the take-up roller 14 was set to 492.5 m / min, and the overfeed rate of the take-up zone was set to 1.5%.

FIG. 8 shows a cross-sectional photograph of the obtained heat-shrinkable composite yarn taken at a magnification of 230 times using an optical microscope (manufactured by Olympus Corporation, trade name “BH2-UMF”). The hollow ratio of the false twist hollow multifilament yarn a in FIG. 8 was 0%, and the degree of deformation was 50%.

Using the obtained heat-shrinkable composite yarn, knitting, refining, dyeing, reduction, and drying treatment were carried out under the same conditions as in Example 1 to obtain a knitted fabric.

(Comparative Example 2)
(1) Highly oriented unstretched multifilament in which titanium oxide fine particles (TiO2) are contained as inorganic oxide fine particles in a proportion of 0.4% by mass instead of the highly oriented unstretched hollow multifilament yarn a and are completely dispersed. The yarn (total fineness: 136.2 dtex, number of single yarns: 36, elongation: 139.2%) was used, and (2) false twisting was changed from fluid swirling false twist to disc false twist under the following conditions. A heat-shrinkable composite yarn (117 dtex54 filament) was obtained under the same conditions as in Example 1 except that the false twisting process and the fluid injection process were performed.

<Casual twist processing conditions>
Surface speed of the first supply roller 6: 398.5 m / min Stretch ratio of polyester drawn yarn b: 1.00 times Surface speed of the second supply roller 7: 232.5 m / min Stretching ratio of polyester highly oriented undrawn yarn a 1.72 times Heater 8 temperature (short part / long part): 215 ° C / 215 ° C
Torture tension: 36.8 g
Untwisting tension: 30.7 g
K value (tension ratio of untwisted / twisted): 0.83
Disc configuration: Z-1-6-K
Disk turning direction: Z direction Disk rotation speed: 640 rotations / minute Surface speed of the first take-up roller 11: 400 m / minute <Fluid injection processing conditions>
Interlaced Nozzle 12: Hevaline P-102
Air pressure of interlaced nozzle 12: 3.0 kg / cm ²
Surface speed of the second take-up roller 13: 386.0 m / min Overfeed rate of interlaced zone: 3.5%

The surface speed of the take-up roller 14 was set to 386.0 m / min, and the overfeed rate of the take-up zone was set to 3.5%.

The false twist hollow multifilament yarn contained in the obtained heat-shrinkable composite yarn was photographed with an optical microscope (manufactured by Olympus Corporation, trade name "BH2-UMF") at a magnification of 230 times. The degree of deformation was 0% and the degree of deformation was 42%.

The obtained heat-shrinkable composite yarn was knitted, refined, dyed, reduced, and dried under the same conditions as in Example 1 to obtain a knitted fabric.

2. 2. Results Table 1 shows the manufacturing conditions and the like of Examples and Comparative Examples. Table 2 shows the evaluation results of the obtained heat-shrinkable composite yarn and knitted fabric.

In Examples 1 to 4, the L value was sufficiently low, and the results were excellent in see-through prevention and texture. In Comparative Example 1, the L value was high, a feeling of wall thickness was obtained, the texture was poor, and although the thickness was larger than that of the example, only the same transparency as that of the example could be achieved. In Comparative Example 2, the hollow portion was crushed and the transparency was inferior, and a thick feeling was obtained and the texture was not soft. The cross section of the false twist hollow multifilament a included in the heat-shrinkable composite yarns of Examples 1 to 4 has a multi-leaf shape similar to the cross section of the oriented unstretched hollow multifilament yarn a used as the raw yarn. there were.

a False twist hollow multifilament a
b Polyester drawn yarn b
1 Single thread 2 First resin part 3 Second resin part 4 Leaf part 5 Hollow part 6 First supply roller 7 Second supply roller 8 Heater 9 Cooling plate 10 Fluid swirling nozzle 11 First take-up roller 12 Interrace nozzle 13 No. (2) Take-up roller 14 Take-up roller 15 Package 16 Thread supply port 17 Air supply port B Polyester fiber B

Claims (10)

A heat-shrinkable composite yarn containing a false twist hollow multifilament a and a polyester drawn yarn b and having a crimp ratio of 5% or less.
The false twist hollow multifilament a has a first resin portion containing more than 2% by mass of inorganic oxide fine particles and 10% by mass or less, and a second resin portion containing 2% by mass or less of inorganic oxide fine particles. Ori,
In the cross section of the single yarn constituting the false twist hollow multifilament a, the second resin portion forms a hollow shape including the inner peripheral surface and the outer peripheral surface of the single yarn, and the first resin portion is the said. A multi-leaf shape including 6 to 30 leaves radially extending from the center side to the outer peripheral side of the hollow shape in the second resin portion is formed, and the leaf portion formed by the first resin portion is formed. May form part of the outer peripheral surface of the single yarn,
The single yarn constituting the false twist hollow multifilament a has a hollow ratio of 10 to 30% and a degree of deformation of 20% or less.
The polyester drawn yarn b has an elongation of 15 to 40% and a boiling water shrinkage rate of 10 to 25%.
Heat shrinkable composite yarn. The heat-shrinkable composite yarn according to claim 1, wherein the torque is 45 T / M or more. Claim 1 or 2, wherein the mass ratio of the false twist hollow multifilament a and the polyester drawn yarn b is (false twist hollow multifilament a) / (polyester drawn yarn) = 95/5 to 65/35. The heat shrinkable composite yarn described. The mass ratio of the first resin portion to the second resin portion in the false twist hollow multifilament a is (first resin portion) / (second resin portion) = 30/70 to 90/10. The heat-shrinkable composite yarn according to any one of claims 1 to 3. A composite yarn in which a false twist hollow multifilament a is arranged on the sheath side and a polyester fiber B is arranged on the core side.
The false twist hollow multifilament a has a first resin portion containing more than 2% by mass of inorganic oxide fine particles and 10% by mass or less, and a second resin portion containing 2% by mass or less of inorganic oxide fine particles. Ori,
In the cross section of the single yarn constituting the false twist hollow multifilament a, the second resin portion forms a hollow shape including the inner peripheral surface and the outer peripheral surface of the single yarn, and the first resin portion is the said. A multi-leaf shape including 6 to 30 leaves radially extending from the center side to the outer peripheral side of the hollow shape in the second resin portion is formed, and the leaf portion formed by the first resin portion is formed. May form part of the outer peripheral surface of the single yarn,
A composite yarn in which the single yarn constituting the false twist hollow multifilament a has a hollow ratio of 10 to 30% and a degree of deformation of 20% or less. A woven or knitted fabric comprising the heat-shrinkable composite yarn according to any one of claims 1 to 4 or the composite yarn according to claim 5. The method for producing a heat-shrinkable composite yarn according to any one of claims 1 to 4, which comprises the following steps (a) to (c).
(A) A step of preparing a highly oriented unstretched hollow multifilament yarn a satisfying the following (1) to (3) and a polyester drawn yarn b having an elongation of 15 to 40% and a boiling water shrinkage rate of 10 to 25%. 1) It has a first resin portion containing more than 2% by mass of inorganic oxide fine particles and 10% by mass or less and polyester, and a second resin portion containing 2% by mass or less of inorganic oxide fine particles and polyester.
(2) Structure In the cross section of the single yarn, the second resin portion forms a hollow shape including the inner peripheral surface and the outer peripheral surface of the single yarn, and the first resin portion is the second resin portion. Inside, a multi-leaf shape including 6 to 30 leaves radiating from the center side to the outer peripheral side of the hollow shape is formed, and the leaf portion formed by the first resin portion is the outer circumference of the single yarn. It may form a part of the surface.
(3) The single yarn has a hollow portion and has a hollow ratio of 12 to 30%.
(B) Using a fluid swirling nozzle, the highly oriented unstretched hollow multifilament yarn a has a false twist coefficient of 15,000 or less , a draw ratio of 1.1 times or less, and a untwisting / twisting tension ratio of 1.0 to 1. In step 25, a false twist process is performed to obtain a false twist hollow multifilament yarn a, and (c) the false twist hollow multifilament yarn a and the polyester drawn yarn b are combined by fluid injection processing to generate heat. The process of obtaining a shrinkable composite yarn. The manufacturing method according to claim 7, wherein the highly oriented unstretched hollow multifilament yarn a prepared in the step (a) further satisfies the following (4) to (7).
(4) Structure In the cross section of the single yarn, the tip portion on the outer peripheral side of the leaf portion has a curved shape.
(5) In the cross section of the constituent single yarn, the ratio of the exposure length of the first resin portion to the outer peripheral surface of the constituent single yarn to the outer peripheral length of the constituent single yarn is 10% or less.
(6) In the cross section of the constituent single yarn, the average value of the ratio of the shortest distance from the outer circumference of the constituent single yarn to the end of the leaf to the distance from the center to the outer circumference of the constituent single yarn is 10% or less. be.
(7) The elongation is 100 to 180%. The method for producing a composite yarn according to claim 5, which comprises a step of performing a heat shrinkage treatment on the heat-shrinkable composite yarn according to any one of claims 1 to 4. A method for producing a woven or knitted product, which comprises the following steps (i) to (iii).
(I) The step of preparing the heat-shrinkable composite yarn according to any one of claims 1 to 4.
(Ii) A step of weaving and knitting the heat-shrinkable composite yarn to manufacture a raw machine, and (iii) a step of performing a heat-shrinking treatment on the raw machine to obtain a woven or knitted product.

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