TWI658183B - Flat section crimped yarn, method for manufacturing the crimped yarn, and knitted fabric containing the crimped yarn - Google Patents

Abstract

Provided is a crimped yarn having a flat fiber cross section and an excellent crimping rate CC, a method for manufacturing the crimped yarn with excellent step passability, and a permeability preventing even if the density is reduced or the basis weight is reduced, A knitted fabric with excellent cold sensitivity. The crimped yarn includes a multifilament, and a cross-sectional shape of a cross-section perpendicular to the fiber axis direction of 50% to 100% by mass of the single fiber of the multifilament is a flat shape, and the flatness of the flat shape is 2.0 to 5.5, and transmittance of visible light having a wavelength of 400 nm to 780 nm when the knitted fabric has a basis weight of 220 g / m ² to 250 g / m ² is 33% or less.

Description

Flat section crimped yarn, method for manufacturing the crimped yarn, and containing Braid of the crimped silk

The present invention relates to a crimped yarn, a method for producing the crimped yarn, and a knitted fabric. The fiber cross section of the crimped yarn perpendicular to the fiber axis direction has a flat shape, and the crimping property is excellent in crimping properties. The knitted fabric contains the crimped yarn, and is a knitted fabric having a small density or a low basis weight, but excellent in permeability resistance and cold feeling.

Previously, long fibers used for clothing were subjected to crimping processing to give bulk. Regarding the crimping processing, false twist processing and frustrating crimping are used, and false twist processing is mainly performed on polyester long fibers, nylon long fibers, acetate long fibers, and polyolefin long fibers.

In addition, the shape of the fiber cross section (hereinafter simply referred to as “fiber cross section”) of the long fibers perpendicular to the fiber axis direction includes various shapes such as a circle, a triangle, a Y shape, and a daisy shape.

On the other hand, when a long fiber having a flat fiber cross section is subjected to false twist processing, derailment due to wire rolling caused by untwisting occurs, which has a problem in processing stability.

Japanese Patent Application Laid-Open No. 2004-346461 (Patent Document 1) discloses a false-twisted yarn of flat fibers having a fiber cross-sectional shape having two or more constrictions. However, the problem of the passability of the residual derailment step cannot be improved. The problem of physical properties with high shrinkage.

The crimped yarn having a flat fiber cross section is expected to have the effects of permeability prevention, heat insulation, and ultraviolet shielding, and therefore, it is required to solve the above problems.

The fiber used for curtains or clothing for the purpose of permeability prevention, heat insulation, and ultraviolet shielding is disclosed in, for example, Japanese Patent Laid-Open No. 11-81048 (Patent Document 2) or Japanese Patent Laid-Open No. 9-137345. Japanese Patent Publication (Patent Document 3) and the like disclose fibers in which white pigments such as titanium oxide, talc or barium sulfate, or inorganic fine particles such as carbon black and aluminum powder are dispersed and contained in the fibers.

Furthermore, for example, Japanese Patent Application Laid-Open No. 2012-12726 (Patent Document 4) discloses a method for improving the heat insulation property of a knitted fabric by using a fiber with a flat cross-section, and Japanese Patent Application Laid-Open No. 2014-177716 Patent Document 5) discloses that a fiber assembly of a core-sheath type profiled composite fiber exhibits excellent heat insulation and permeability, and the core-sheath type profiled composite fiber is a leaf-shaped fiber having a core shape and a core The component contains a thermoplastic polymer containing 8% by weight to 70% by weight of a minute sunlight shielding substance, and the sheath component contains a polyester-based polymer which contains 0.5% by weight Above 10 wt% inorganic fine particles.

[Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2004-346461

[Patent Document 2] Japanese Patent Laid-Open No. 11-81048

[Patent Document 3] Japanese Patent Laid-Open No. 9-137345

[Patent Document 4] Japanese Patent Laid-Open No. 2012-12726

[Patent Document 5] Japanese Patent Laid-Open No. 2014-177716

An object of the present invention is to provide a crimped yarn having a flat fiber cross section and an excellent crimping rate CC, and a method for producing the crimped yarn having excellent step passability.

Another object of the present invention is to provide a knitted fabric having excellent permeability and cold feeling even if the density or basis weight is reduced.

The main configuration of the present invention satisfies any of 1 to 15 below.

A crimped yarn comprising a multifilament, and a cross-sectional shape of a cross-section perpendicular to the fiber axis direction of 50% to 100% by mass of the single fiber of the multifilament is a flat shape, and the flatness of the flat shape is flat It is 2.0 to 5.5, and the transmittance of visible light having a wavelength of 400 nm to 780 nm when the knitted fabric has a basis weight of 220 g / m ² to 250 g / m ² is 33% or less.

2. The crimped yarn according to 1, wherein the crimping rate CC of the multifilament is 15% to 60%, and the crimping return rate CR is 80% or more.

3. The crimped yarn according to 1 or 2, which has a hollow portion or a contact surface in a cross section of the single fiber perpendicular to the fiber axis direction.

4. The crimped yarn according to any one of 1 to 3, wherein the single fiber fineness of the single fiber constituting the multifilament is 1 dtex to 8 dtex, and the content of titanium oxide is 1.5% by mass to 5 Mass%, the total fineness of the multifilament is 33dtex ~ 250dtex.

5. A method for manufacturing a crimped yarn, in which false twist processing is performed at a false twist coefficient of 16000 to 42000, the multifilament containing 50% by mass or more of a cross-sectional shape of a cross section perpendicular to a fiber axis direction having a hollow portion Single fiber; false twist coefficient = (spindle speed rpm / false twist speed m / min) × (total fineness of false twist crimped yarn) ^1/2 .

6. The method for manufacturing a crimped yarn according to 5, wherein the cross-sectional shape of the cross-section of the multifilament perpendicular to the fiber axis direction has a hollow portion, and the cross-sectional shape is a polygon of four to eight corners.

A knitted fabric comprising a multi-filament crimped yarn having a content of 50% to 100% by mass, a density of 0.40 g / cm ³ or less, and a visible light transmittance of a wavelength of 400 nm to 780 nm of 33% or less. The shape of the cross-section perpendicular to the fiber axis direction of 50% to 100% by mass of the single fiber of the multifilament is a flat shape, and the flatness of the flat shape is 2.0 to 5.5.

8. The knitted fabric according to 7, wherein the crimped yarn is a multifilament with a crimp rate CC of 15% to 60%.

9. The knitted fabric according to 7 or 8, which has a hollow portion or a contact surface in a cross section perpendicular to the fiber axis direction.

10. The knitted fabric according to any one of 7 to 9, which has a basis weight of 50 g / m ² to 200 g / m ² and a cloth thickness of 0.2 mm to 0.5 mm.

11. The knitted fabric according to any one of 7 to 10, wherein the crimped yarn is a false twisted yarn.

12. The knitted fabric according to any one of 7 to 11, wherein the single fiber fineness of the crimped yarn is 1 dtex to 8 dtex, and the total fineness is 33 dtex to 250 dtex.

13. The knitted fabric according to any one of 7 to 12, wherein a crimped repetition rate CR of the crimped yarn is 80% or more.

14. The knitted fabric according to any one of 7 to 13, which has a thermal insulation property of 41.5 ° C or lower and a Qmax of 0.22 or higher.

15. The knitted fabric according to any one of 7 to 14, wherein the crimped yarn is arranged on one side of a fabric.

According to the present invention, it is possible to provide a crimped yarn having an excellent crimping rate CC and excellent step stability in crimping processing. Moreover, according to this invention, the manufacturing method of the crimped yarn which is excellent in process passability can be provided. In addition, according to the present invention, it is possible to provide a knitted fabric which has better permeability and cold feeling properties than before, even if the density is reduced or the basis weight is reduced.

FIG. 1 is a sectional photograph of the multifilament before crimping.

Fig. 2 is a cross-sectional photograph of a crimped wire after being crimped.

Hereinafter, embodiments of the present invention will be described in detail.

The crimped yarn of the present invention is a crimped yarn including a multifilament, and a cross-sectional shape of a cross-section perpendicular to the fiber axis direction of a single fiber of 50% to 100% by mass of the multifilament is a flat shape, and the flat shape with a flatness of 2.0 to 5.5, a basis weight in the formed wavelength at 220g / m ² ~ 250g / m ² knitted transmittance of visible light is 400nm - 780 nm is 33% or less.

The so-called flatness here means that the ratio (A / B) of the length (A) of the long side of the circumscribed rectangle to the length (B) of the circumscribed rectangle reaches the maximum value in the cross section of the single fiber perpendicular to the fiber axis direction. The ratio of the circumscribed rectangle is the flatness.

When the flatness is 2.0 or more, excellent barrier properties, heat insulation, and light-shielding properties can be obtained. When the flatness is 5.5 or less, the texture does not become too hard when knitted.

From these viewpoints, the flatness is more preferably 2.2 to 5.0, and further preferably 2.4 to 4.0.

If the cross-sectional shape of the cross section with respect to multifilament contained 50 mass% or more to the fiber axis is perpendicular to the flat shape of the single fiber, it is easily made to a basis weight of ^{220g / m 2 ~ 250g / m} 2 of The visible light transmittance at a wavelength of 400 nm to 780 nm in a knitted fabric is 33% or less.

From these viewpoints, the content of the flat single fiber with respect to the multifilament is more preferably 70% by mass or more, and even more preferably 90% by mass or more.

When the transmittance of visible light having a wavelength of 400 nm to 780 nm becomes 33% or less when a knitted fabric having a basis weight of 220 g / m ² to 250 g / m ² is made, even if the knitted fabric is thinned, it is easy to obtain the barrier property.

The crimped yarn of the present invention is preferably such that the crimping rate CC of the multifilament is 15% to 60%, and the crimping return rate CR is 80% or more.

If the crimping rate CC is 15% or more, the swelling of the knitted fabric can be obtained. If the feeling of looseness or rebound is 60% or less, there is no thick feeling, and a moderate bulky feeling can be obtained.

From these viewpoints, the shrinkage rate CC is more preferably 25% to 55%.

In addition, if the crimping reversion rate CR is 80% or more, it is easy to obtain a bulky feeling and a rebounding feeling at the same time. From this viewpoint, it is more preferable that the roll-up response rate CR is 85% or more.

The crimped yarn of the present invention preferably has a hollow portion or a contact surface in a cross section of the single fiber perpendicular to the fiber axis direction.

By having a hollow portion or a contact surface, and having the effects of reflection and scattering inside the fiber, excellent transparency, heat insulation, and light shielding properties can be obtained.

The contact surface is a portion where the hollow portion is crushed and the inner wall surfaces of the hollow portion are in contact with each other.

The crimped yarn of the present invention is preferably a single fiber having a single fiber fineness of 1 dtex to 8 dtex, a titanium oxide content of 1.5 to 5% by mass, and a total fineness of the multifilament of 33 dtex to 250 dtex.

If the single-fiber fineness is 1 dtex or more, it is easy to have a flat shape with a flatness of 2.0 or more, and if it is 8 dtex or less, it is easy to obtain a soft hand when making a knitted fabric.

From these viewpoints, the single fiber fineness is more preferably 1.5 dtex to 6.0 dtex, and further preferably 2.0 dtex to 4.0 dtex.

When the content of the titanium oxide is 1.5% by mass or more, barrier properties, heat insulation, and light-shielding properties are easily obtained. When the content is 5% by mass or less, yarn breakage is reduced and spinnability is improved.

From these viewpoints, the content of the titanium oxide is more preferably 1.7% to 3% by mass.

In addition, if the total fineness of the multifilament is 33 dtex or more, the number of constituents of the multifilament can be increased, and permeability and heat insulation properties can be easily obtained. Moreover, if it is 250 dtex or less, it is preferable that the feeling in clothing use will not become too hard.

From these viewpoints, the total fineness is more preferably 50 dtex to 200 dtex, and even more preferably 70 dtex to 170 dtex.

The manufacturing method of the crimped yarn of the present invention is a method of manufacturing a crimped yarn with a false twist coefficient of 16,000 to 42,000, and false-twisting a multifilament containing 50% by mass or more in a direction perpendicular to the fiber axis A single fiber with a hollow portion in its cross section.

The false twist coefficient is calculated from the spindle rotation speed T (rpm), the false twist speed S (m / min), and the total fineness D (dtex) of the false twist processed yarn as (T / S) × D ^1/2 .

If a hollow portion is included in the cross-sectional shape, the hollow portion is crushed during false twist processing, so the cross-sectional shape is likely to be flat.

If the false twist coefficient is 16,000 or more, the hollow portion is crushed and the cross-sectional shape of the fiber becomes flat, and a crimped yarn with a crimp ratio CC of 15% or more can be obtained. If it is 42,000 or less, a crimp ratio CC can be obtained. It is a crimped yarn with a stable quality of 60% or less and without fluff.

From these viewpoints, the false twist coefficient is more preferably 18000 to 38000, and further preferably 20,000 to 35,000.

The method for manufacturing the crimped yarn of the present invention is more preferably that the multifilament is perpendicular to The cross-sectional shape of the cross section in the direction of the fiber axis is a polygon of four to eight corners.

By making a polygon, the cross section is easily deformed with the vertex as the center, and it is easy to become flatter. From this point of view, the cross-sectional shape is further preferably pentagonal to pentagonal.

The corners of the polygon may also have radians, but the radius of curvature of the radians is smaller than the radius of the inscribed circle of the polygon. In addition, not all sides may be constituted by straight lines, and the multifilament may include monofilaments in which a part of sides of the fiber cross-sectional shape is a curve, or a part of the polygonal monofilament with arcs at corners.

The crimped yarn of the present invention crushes the hollow portion of each single fiber into a flat shape, but if the flatness is in the range of 2.0 to 5.5, the hollow portion may remain. When a hollow portion is present, the refraction or scattering of light is increased, and thus it is easy to reduce the transmittance of visible light.

When false twist processing is performed on a multifilament having a flat fiber cross-section of a single fiber, derailment due to yarn rolling caused by untwisting occurs, and the multifilament is easily detached from a supply roll or the like, which is stable in production. There are problems.

By making the cross-sectional shape of the single fiber into a circular cross-section or a polygonal shape, it is possible to prevent detachment from the supply roller or the like.

In the method for producing a crimped yarn of the present invention, the false twist temperature is preferably set to 160 ° C to 220 ° C.

The false twist temperature refers to the temperature of the hot plate immediately before the spindle to which the false twist is applied.

When the false twist temperature is 160 ° C or higher, the crimping rate CC can be increased, and when it is 220 ° C or lower, the fiber can be melted and cut. From these viewpoints, the false twist temperature is more preferably set to 170 ° C to 210 ° C.

The manufacturing method of the crimped yarn of the present invention is preferably hollowing the multifilament The hollow ratio of the part is set to 10% to 40%. If the hollow ratio is 10% or more, it will easily become a flat shape, and if it is 40% or less, it will have good spinnability and become homogeneous filaments, and the crimped yarn of the present invention can be obtained with uniform quality. From these viewpoints, it is more preferable to set the hollow ratio to 12% to 30%.

The type of the fiber used for the crimped yarn of the present invention is not particularly limited, and may be a chemical fiber. Examples include polyethylene terephthalate fibers, nylon fibers, polypropylene fibers, and acrylic fibers. Among these, polyethylene terephthalate fiber is more preferable in terms of having a cool feeling and producing a profiled hollow fiber.

Examples of the polymer constituting the crimped yarn include polyesters having ethylene terephthalate as a main structural unit, and a copolymer may be contained in the polyester. Examples of the copolymerization component include aromatic and aliphatic dicarboxylic acid components other than terephthalic acid components such as isophthalic acid components, isophthalic acid components containing sulfonic acid metal salt groups, and adipic acid components. Aliphatic diol components other than ethylene glycol components.

The crimped yarn of the present invention preferably has a single fiber strength of 2.0 cN / dtex to 5.0 cN / dtex. If the single fiber strength is 2.0 cN / dtex or more, the fiber bundle is not easily cut during weaving or knitting of the knitted fabric, so it is preferable. The upper limit of the fiber strength is sufficient if it is about 5.0 cN / dtex.

The manufacturing method of the said multifilament used for the crimped yarn of this invention can use the general melt-spinning process and drawing process similarly to the normal melt-spinning of polyethylene terephthalate.

First, in the melt spinning step, the thermoplastic resin of the raw material is melted from the spinning nozzle. Extruded to obtain unstretched filaments, which are temporarily wound up and then stretched in the stretching step to obtain fibers. The stretching step can be continuously stretched in an in-line manner after spinning the unstretched yarn, or it can be independently stretched after being wound up on another production line. In addition, the extending step may be one stage, or may be a multi-stage of two or more stages. Furthermore, the heat source used in the extension step may be any of a contact-type or a non-contact-type heat source. The draw ratio can also be arbitrarily set within a range before reaching the elongation at break of the undrawn yarn obtained by melt spinning.

For example, it is sprayed from a spinning nozzle at a spinning temperature of 270 ° C to 300 ° C, and is drawn at a spinning (extraction) speed of 1000m / min ~ 2000m / min to make an undrawn yarn, and the drawing speed is 200m / min ~ 800m / min The stretching ratio is 0.65 to 0.80 times the maximum stretching ratio, the stretching temperature is 60 ° C to 90 ° C, and the heat setting temperature is 100 ° C to 170 ° C. The hollow section polyester multifilament is obtained in the form of stretched yarn. The maximum draw ratio refers to the draw ratio at which the undrawn yarn is drawn at a draw temperature of 80 ° C, a heat setting temperature of 145 ° C, and a draw speed of 600 m / min.

In addition, during the spinning process, the following methods can be adopted: the undrawn yarn that is spun out is temporarily wound up and stretched; the undrawn yarn that is spun out is stretched without being wound up; the spinning speed is 3000 m high-speed spinning and winding at high speeds above min / min, or high-speed spinning without drawing up, etc.

In order to efficiently obtain the crimped yarn of the present invention, it is more preferable to use a high-alignment undrawn yarn by high-speed spinning at a spinning speed of 3,000 m / min or more. In the case of the drawn yarn, since the crystal orientation is performed, the hollow portion is not easily deformed and the flatness tends to decrease.

In the knitted fabric of the present invention, the content of the crimped yarn including the multifilament is 50% to 100% by mass, the density is 0.40 g / cm ³ or less, and the visible light transmittance at a wavelength of 400 nm to 780 nm is 33% or less. The shape of a cross section perpendicular to the fiber axis direction of the 50% to 100% by weight single fiber constituting the multifilament is a flat shape, and the flatness of the flat shape is 2.0 to 5.5.

In the knitted fabric of the present invention, the false-twisted yarn is preferably composed of a multifilament yarn.

The so-called multifilament is an aggregate of a plurality of long fibers. With the presence of a plurality of fibers, light is easily reflected and scattered, and the transmittance of visible light is easily reduced.

From this viewpoint, the number of fibers constituting the multifilament is preferably 20 or more, and more preferably 30 or more.

By containing flat-shaped fibers with a cross-section perpendicular to the fiber axis direction, visible and infrared light are easily reflected and scattered, so it is easy to obtain the effect of preventing light transmission. Soft feel for clothing.

In addition, the knitted fabric of the present invention has a density of 0.40 g / cm ³ or less and a visible light transmittance of wavelengths of 400 to 780 nm of 33% or less. Therefore, the knitted fabric is lightweight and has good barrier properties. It is particularly suitable for sports clothing, Uniform.

From the viewpoint of reducing the weight, if the transmittance is 33% or less, the density is more preferably 0.30 g / cm ³ or less, and even more preferably 0.192 g / cm ³ or less.

When the content of the crimped yarn including the multifilament is 50% by mass or more, the transmittance of visible light having a wavelength of 400 nm to 780 nm is easily 33% or less.

The higher the content of the multifilament-containing crimped yarn, the greater the effect of the barrier properties, but if Visible light with a wavelength of 400 to 780 nm has a transmittance of 33% or less, and can be combined with other fibers.

The knitted fabric of the present invention is preferable if the transmittance of visible light having a wavelength of 400 nm to 780 nm is 33% or less, since it is difficult to see underwear or the like through the knitted fabric. From this viewpoint, the transmittance is preferably 31% or less, and more preferably 29% or less.

If the false-twist processed yarn has a visible light transmittance of less than 33% at a wavelength of 400 nm to 780 nm, it can also be compounded with other fibers to form a composite false-twist processed yarn. The false-twisted yarn includes the composite false-twisted processing wire.

For example, polyurethane fibers can be compounded to provide stretchability.

The ratio of the other fibers to the false-twist-processed yarn is preferably 20% by mass or less in terms of reducing visible light transmittance.

In addition, if the content of the crimped yarn with respect to the knitted fabric is 50% by mass or more, the effect of preventing the transmission of visible light and infrared light is easily obtained. From this viewpoint, the content of the crimped yarn with respect to the knitted fabric is preferably 60% by mass or more, and more preferably 70% by mass or more.

In the knitted fabric of the present invention, the flatness of the flat shape is preferably 2.0 to 5.5.

If the flatness of the flat shape is 2.0 or more, the effect of preventing the transmission of visible light and infrared light is easily obtained. If the flatness is 5.5 or less, it is difficult to cause fluff and the like during silk processing such as false twist processing.

From these viewpoints, the flatness of the flat shape is preferably 2.2 to 5.0, and more preferably 2.4 to 4.0.

The knitted fabric of the present invention is preferably a multifilament yarn having a crimp ratio CC of 15% to 60% of the crimped yarn.

If the shrinkage rate CC is 15% or more, a bulky feeling or a springback feeling of the knitted fabric can be obtained, and if it is 60% or less, there is no thick feeling and a moderate bulky feeling can be obtained.

From these viewpoints, the shrinkage rate CC is more preferably 25% to 55%.

The knitted fabric of the present invention preferably has a hollow portion or a contact surface in a cross section perpendicular to the fiber axis direction.

By having a hollow portion or a contact surface in a cross section perpendicular to the fiber axis direction, refraction or scattering of light occurs, so it is easy to reduce the transmittance of visible light. The contact surface refers to a portion where the hollow portion is crushed and the inner wall surfaces of the hollow portion are in contact with each other, the surface of the inner wall surface of the hollow portion and the gas layer, and the boundary surface of the core and sheath portions of the core-sheath structure.

The knitted fabric of the present invention preferably has a basis weight of 50 g / m ² to 200 g / m ² and a cloth thickness of 0.2 mm to 0.5 mm.

If the basis weight of the knitted fabric is 50 g / m ² or more, the effect of preventing visible light and infrared light from being transmitted can be obtained. If the basis weight of the knitted fabric is 200 g / m ² or less, it can be used as a spring and summer material that requires the effect of preventing visible light and infrared light from passing Make the knitted fabric thin and light. From these viewpoints, the lower limit of the basis weight of the knitted fabric is preferably 60 g / m ² or more, and more preferably 70 g / m ² or more. The upper limit of the basis weight of the knitted fabric is preferably 180 g / m ² or less, and more preferably 170 g / m ² or less.

The knitted fabric of the present invention preferably has a cloth thickness of 0.2 mm to 0.5 mm.

If the thickness of the cloth is 0.2mm or more, it is easy to obtain the effect of preventing the transmission of visible light and infrared light. If the thickness of the cloth is 0.5mm or less, the knitted fabric becomes thin, which is suitable for spring and summer clothing. material.

From these viewpoints, the cloth thickness is more preferably 0.3 mm to 0.45 mm.

In the knitted fabric of the present invention, the crimped yarn is preferably a false twisted yarn.

In the case of a false-twist-processed yarn, the fiber cross section of a single fiber tends to be a flat shape, and the crimping rate CC is easily 15% to 60%.

The knitted fabric of the present invention preferably has a single fiber fineness of 1 dtex to 8 dtex and a total fineness of 33 dtex to 250 dtex.

If the single fiber fineness of the fibers constituting the crimped yarn is 1 dtex or more, the yarn strength is sufficient, and it is difficult to break the yarn during weaving and knitting. Feel.

From these viewpoints, the single fiber fineness of the fibers constituting the crimped yarn is more preferably 1.5 dtex to 6.0 dtex, and even more preferably 2.0 dtex to 4.0 dtex.

If the total fineness of the crimped yarn is 33 dtex or more, the number of constituent yarns of the multifilament can be increased, so the permeability is improved, and the yarn strength necessary for weaving and knitting can be obtained. Makes the fabric thin. From these viewpoints, the total fineness of the crimped yarn is more preferably 50 dtex to 200 dtex, and even more preferably 70 dtex to 170 dtex.

In the knitted fabric of the present invention, it is preferable that the crimped reversion ratio CR of the crimped yarn is 80% or more.

If the crimped reversion ratio CR of the crimped yarn is 80% or more, it is easy to obtain a bulky feeling and a springback feeling at the same time. From this viewpoint, it is more preferable that the crimping recovery rate CR of the crimped yarn is 85% or more.

The knitted fabric of the present invention preferably has a heat insulation property of 41.5 ° C or lower and a Qmax of 0.22 or higher.

When the heat insulation property is 41.5 ° C. or lower, even if it is irradiated with sunlight, the temperature rise in the clothes is small, and a comfortable wearing feeling can be obtained. From this viewpoint, the heat insulation is more preferably 41 ° C or lower.

In addition, if the Qmax is 0.22 or more, a cold feeling is easily felt when the knitted fabric comes into contact with the skin. From these viewpoints, the Qmax is more preferably 0.23 or more, and even more preferably 0.24 or more.

In the knitted fabric of the present invention, the crimped yarn is preferably arranged on one side of the fabric.

When the crimped yarn is arranged on one side of the fabric, the side can be arranged on the outside to provide good permeability and heat insulation properties. By using the other side as the skin side, skin touch can be used. Various materials such as good materials or materials that absorb water quickly.

The knitted fabric of the present invention is preferably a polyester fiber in which the shape of the cross section perpendicular to the fiber axis direction is a flat shape. Since the fiber is a polyester fiber, the fabric has excellent strength, light resistance, dyeability, fastness, and the like.

In terms of preventing light transmission, the polyester fiber preferably has a titanium oxide fine particle content of 1% to 3% by mass. When the content of the titanium oxide fine particles with respect to the polyester fiber is 1% by mass or more, the effect of preventing light transmission is easily obtained, and when the content is 3% by mass or less, breakage during spinning can be reduced, which is preferable.

The knitted fabric of the present invention may contain other fibers in a range in which the transmittance of visible light does not exceed 33%.

Other fibers may also be natural fibers or chemical fibers, and there is no particular limitation.

The structure of the knitted fabric of the present invention is not particularly limited.

[Example]

Hereinafter, the present invention will be described more specifically based on examples.

[Flatness]

The ratio of the circumscribed rectangle where the ratio (A / B) of the length (A) of the long side of the circumscribed rectangle to the length (B) of the circumscribed rectangle reaches a maximum value in the cross section of the single fiber perpendicular to the fiber axis direction. As flatness.

[Curling rate CC, CR rate CR]

The roll-back response rate CR refers to the elastic modulus of expansion measured and calculated in accordance with the "Japanese Industrial Standards (JIS) 1013 8.11 C method".

The shrinkage rate CC is a value of "(b-c / b) × 100" in the "JIS1013 8.11 C method".

[False twist coefficient]

The false twist coefficient is calculated by the following formula.

False twist coefficient = (T / S) × D ^1/2

T: Spindle speed, S: False twist speed, D: Total fineness of crimped yarn (dtex)

(Measurement method of transmittance of visible light and infrared light)

A 30 cm × 30 cm knitted fabric sample was allowed to stand for 24 hours in a test room managed at an ambient temperature of 20 ° C. and a humidity of 65%. A spectrophotometer (U-3400 manufactured by Hitachi) was used for the fabric sample, and the following (1) to (5) were performed in this order. Operation.

(1) Prepare a knitted fabric to be measured.

(2) The transmittance (%) of the sample-free state (hereinafter referred to as Tg) is measured in the range of 250 nm to 2000 nm in 5 nm units.

(3) The sample is mounted on a spectrophotometer, and the transmittance (%) in the state of the sample (hereinafter referred to as Ts) is measured in a unit of 5 nm in a wavelength range of 250 nm to 2000 nm of light.

(4) In the range of 250 nm to 2000 nm, use the following equation to correct Ts in units of 5 nm to calculate the corrected transmittance (hereinafter referred to as T).

T = (Ts / Tg) × 100

(5) Calculate the arithmetic average of each T in the visible light range of 400 nm to 780 nm and the infrared light range of 780 nm to 2000 nm as the visible light transmittance and infrared light transmittance.

(Method for measuring cloth thickness)

The measurement was performed in accordance with JIS L 1096 (2010) 8.4 A method.

(Measurement method of air permeability)

The air permeability tester FX3300 (manufactured by TEXTEST) was used in an environment-variable room at 20 ° C and a relative humidity of 65% in accordance with JIS L 1096 permeability A method (Frazir Type method). ) Is measured to determine the air permeability (cm ³ / cm ² / s) at this time.

(Method for measuring thermal insulation)

A 30cm × 30cm fabric sample was managed to have an ambient temperature of 20 ° C and humidity. The test chamber was left at rest for 65 hours with a degree of 65%. The fabric sample was held on 5 mm of a hot-wire light receiver (black drawing paper), and the sample was irradiated with a reflector lamp from a distance of 50 cm above the sample. The temperature of the center of the hot-wire light receiver was measured with a thermocouple over time for 15 minutes. Let the temperature after 15 minutes be the temperature of heat insulation.

The test was performed six times, and the average value of the data was used as the test result.

Lamp used: Incandescent lamp <Spot> PRS100V500W manufactured by Iwasaki Electric Co., Ltd.

(Example 1)

Polyethylene terephthalate containing 0.676% of titanium dioxide having an intrinsic viscosity of 0.676 was melted, and the obtained melt was heated to 280 ° C to arrange six middle-folded slits having an inner angle of 120 ° in a ring shape. As a group, the ejection holes with a diameter of 1.1 mm Φ formed as a circumscribed circle are used to eject the melt from the ejection holes of a spinning nozzle having 36 groups of the ejection holes, and take up the coil at a extraction speed of 3000 m / min to make a high The unstretched yarn was aligned to produce a polyester multifilament of 135 dtex / 36 filament (f). As shown in FIG. 1, the obtained polyester multifilament is a multifilament with a single fiber accounting for 89% of all the single fiber number in the fiber cross section of the multifilament. The cross-sectional shape of the fiber of the single fiber is a regular hexagon. There is a single, circular hollow portion in the cross section, and the hollow ratio is 17.5%.

Then, the obtained polyester multifilament was subjected to false twist processing under the conditions of setting the false twist heater temperature to 200 ° C., the spindle speed to 402300 rpm, and the false twist speed to 100 m / min to obtain 96.7 dtex / 36 filament Curling silk. The false twist coefficient at this time was 39561. The physical properties are shown in Table 1.

In the false twist process, no silk rolls that are considered to be caused by untwisting have occurred Off track.

In addition, with respect to the crimped yarn subjected to false twist processing, the fiber cross section of the single fiber has a flat shape as shown in FIG. 2.

Furthermore, four obtained crimped yarns were aligned, and a rib knitted fabric was knitted with a 16G flat knitting machine. This knitted fabric was measured for visible light transmittance, infrared light transmittance, air permeability, basis weight, cloth thickness, and heat insulation. The density is calculated from the basis weight cloth thickness. The results are shown in Table 1.

(Example 2 and Example 3)

A crimped yarn was obtained in the same manner as in Example 1 except that the multi-filament yarn obtained in Example 1 was used and the spindle rotation speed was changed to the conditions shown in Table 1 regarding the false twist conditions. The physical properties are shown in Table 1.

In the false twisting process, no derailment due to wire rolling, which is considered to be caused by untwisting, occurred.

In addition, with respect to the crimped yarn subjected to false twist processing, the fiber cross section of the single fiber has a flat shape.

Furthermore, four obtained crimped yarns were aligned, and a rib knitted fabric was knitted with a 16G flat knitting machine. This knitted fabric was measured for visible light transmittance, infrared light transmittance, air permeability, basis weight, cloth thickness, and heat insulation. The density is calculated from the basis weight cloth thickness. The results are shown in Table 1.

(Example 4)

Polymerization using 110 dtex / 30 filaments containing 0.35 mass% titanium dioxide, a cross-sectional shape perpendicular to the fiber axis direction, a circular cross section, and a hollow portion with a single circular shape The expanded yarn of the ester multifilament was changed to the false twist conditions shown in Table 1, and false twist processing was performed in the same manner as in Example 1 to obtain a crimped yarn. The physical properties are shown in Table 1.

In the false twisting process, no derailment due to wire rolling, which is considered to be caused by untwisting, occurred.

The crimped yarn subjected to false twist processing was observed for the fiber cross section of the single fiber, and as a result, a flat-shaped false twist processed yarn was obtained.

Furthermore, the three obtained crimped yarns were aligned, and a rib knitted fabric was knitted with a 16G flat knitting machine. This knitted fabric was measured for visible light transmittance, infrared light transmittance, air permeability, basis weight, cloth thickness, and heat insulation. The density is calculated from the basis weight cloth thickness. The results are shown in Table 1.

(Comparative example 1)

A crimped yarn was obtained in the same manner as in Example 1 except that the false twist conditions were changed to those shown in Table 1 using the multifilament yarn obtained in Example 1. The physical properties are shown in Table 1.

As for the processed yarn subjected to false twist processing, the fiber cross section of the single fiber was observed. As a result, although the false-twist processed yarn having a flat shape was obtained, the flatness and the shrinkage rate CC were low.

In the false twisting process, no derailment due to wire rolling caused by untwisting occurred.

Furthermore, four obtained crimped yarns were aligned, and a rib knitted fabric was knitted with a 16G flat knitting machine. This knitted fabric was measured for visible light transmittance, infrared light transmittance, air permeability, basis weight, cloth thickness, and heat insulation. In addition, the density is calculated based on the basis weight cloth thickness Out. The results are shown in Table 1.

(Comparative example 2)

Polyester multifilament with high-alignment unstretched 90dtex / 36 filaments containing 0.35 mass% titanium dioxide, a cross-sectional shape perpendicular to the fiber axis direction, a circular cross-section, and no hollow portion was used. Except for the conditions, a crimped yarn was obtained in the same manner as in Example 1.

Regarding the fiber cross section of the single fiber of the crimped yarn, although a false-twist processed yarn having a deformed cross section can be obtained, the flatness is low. The physical properties are shown in Table 1.

Furthermore, the six obtained crimped yarns were aligned, and a rib knitted fabric was knitted with a 16G flat knitting machine. This knitted fabric was measured for visible light transmittance, infrared light transmittance, air permeability, basis weight, cloth thickness, and heat insulation. The density is calculated from the basis weight cloth thickness. The results are shown in Table 1.

In addition, the fabric produced in Example 1 and the fabric produced in Comparative Example 2 were subjected to a color scale for discoloration and fading, and the permeability of the fabrics of Example 1 and Comparative Example 2 was compared. As a result, the fabric of Example 1 Better permeability.

Furthermore, the fabrics were not dyed.

(Knit fabric sample)

The fabric sample to be described below refers to a knitted fabric sheet obtained by cutting each fabric used in (Example 5) and (Comparative Example 3) described below into 30 cm × 30 cm, respectively.

(Qmax measurement method)

The Qmax value of the contact temperature and cold sensation was measured by using Thermolab II manufactured by Keto-Tech Co., Ltd. under the conditions of an ambient temperature of 20 ° C and a hot plate temperature of 40 ° C.

(Example 5)

Polyethylene terephthalate having 2% by mass of titanium dioxide and an intrinsic viscosity of 0.676 was melted and heated to 280 ° C to obtain a melt, and six middle-folded slits having an inner angle of 120 degrees were arranged in a ring shape. And the diameter of the circumscribed circle is 1.1mmΦ. One group, the melt is ejected from the ejection holes of a spinning nozzle having 36 groups of the ejection holes to form a fibrous shape, and is wound up at an extraction speed of 3000 m / min to produce a high-alignment unstretched yarn to produce 135dtex Polyester multifilament of 36 filaments (f). The obtained polyester multifilament is a multifilament in the single fiber cross section of the multifilament with the following single fibers accounting for 89% of the total number of single fibers. The hollow portion of the circular shape had a hollow ratio of 17.5%.

Then, the obtained polyester multifilament was subjected to false twist processing under the conditions of a false twist heater temperature of 180 ° C., a spindle rotation speed of 495,000 rpm, and a false twist speed of 150 m / min to obtain a crimped yarn of 84 dtex / 36 filament. The false twist coefficient at this time was 29,700.

In the false twisting process, no derailment due to wire rolling, which is considered to be caused by untwisting, occurred.

Table 2 shows the flatness of the crimped yarn subjected to false twist processing.

Using the obtained false-twisted yarn and a textile yarn (cotton yarn size: 40 /-) containing 100% by mass of cotton, a knitted fabric of a pique texture was produced.

In the dyeing process step, a polyester fiber is subjected to a hydrophilization treatment to impart water absorption.

Table 2 shows the mixing ratio, basis weight, and cloth thickness of the obtained knitted fabric.

Furthermore, the visible light transmittance, infrared light transmittance, and Qmax of the obtained knitted fabric were measured. The results are shown in Table 2.

(Comparative example 3)

False twist processing using false twist processing of a semi-matte polyester fiber having a titanium oxide content of 0.8% by mass and a cross section perpendicular to the fiber axis direction with a circular cross section. False-twist processing of semi-dull polyester fibers (84 dtex / 36 filaments) with a titanium oxide content of 0.8% by mass and a cross section perpendicular to the fiber axis direction with a circular cross section. False-twist-processed yarn (88 dtex / 36 filament) and a textile yarn (cotton yarn size: 40 /-) containing 100% by mass of cotton were used to produce a knitted fabric with a pearl mesh structure.

In the dyeing process step, a polyester fiber is subjected to a hydrophilization treatment to impart water absorption.

Table 2 shows the mixing ratio, basis weight, and cloth thickness of the obtained knitted fabric.

Furthermore, the visible light transmittance, infrared light transmittance, and Qmax of the obtained knitted fabric were measured. The results are shown in Table 2.

Compared with the knitted fabric of Example 6, the obtained knitted fabric had higher visible light transmittance and infrared light transmittance, poor permeability, low Qmax value, and poor cold sensitivity.

[Industrial availability]

The crimped yarn of the present invention is a crimped yarn with a flat cross section, and is suitable as a material for various textiles.

Claims (13)

A crimped yarn includes a multifilament, and a cross-sectional shape of a cross-section perpendicular to a fiber axis direction of a single fiber having a hollow portion of 50% to 100% by mass of the multifilament is a flat shape. The flatness is 2.0 to 5.5. In the cross section of the single fiber that is perpendicular to the fiber axis direction, the contact surface having the inner wall surface of the hollow portion in contact with each other is produced in the form of rib knitted fabric by a 16G flat knitting machine. When a knitted fabric having a basis weight of 220 g / m ² to 250 g / m ² is used, the transmittance of visible light having a wavelength of 400 nm to 780 nm is 33% or less. The crimped yarn according to item 1 of the scope of patent application, wherein the crimping rate CC of the multifilament is 15% to 60%, and the crimping response rate CR is 80% or more. The crimped yarn according to item 1 or item 2 of the patent application scope, wherein the single fiber fineness of the single fiber constituting the multifilament is 1 dtex to 8 dtex, and the content of titanium oxide is 1.5% to 5% by mass. The total fineness is 33dtex ~ 250dtex. A method for manufacturing a crimped yarn, wherein false twist processing is performed on a multifilament yarn with a false twist coefficient of 16000 to 42000, wherein the multifilament yarn contains 50% by mass or more of a cross-sectional shape of a cross section perpendicular to the fiber axis direction and has a hollow portion. Fiber, the cross-sectional shape of the cross section of the single fiber perpendicular to the fiber axis direction is a flat shape, and the flatness of the flat shape is 2.0 to 5.5, and the cross section of the single fiber is perpendicular to the fiber axis direction. Contact surfaces where the inner wall surfaces of the hollow portion are in contact with each other; false twist coefficient = (spindle speed pm / false twist speed m / min) × (total fineness of false twist crimped yarn) ^1/2 . The method for manufacturing a crimped yarn according to item 4 of the scope of patent application, wherein the cross-sectional shape of the cross section of the single fiber perpendicular to the fiber axis direction has a hollow portion, and the cross-sectional shape of the cross section perpendicular to the fiber axis direction is four corners. ~ Octagonal polygon. A knitted fabric comprising a multi-filament crimped yarn having a content of 50% to 100% by mass, a fabric density of 0.40 g / cm ³ or less, and a visible light transmittance of a wavelength of 400 nm to 780 nm of 33% or less. 50 to 100% by mass of the multifilament has a single fiber having a hollow portion, the shape of a cross section perpendicular to the fiber axis direction is a flat shape, and the flatness of the flat shape is 2.0 to 5.5, which is perpendicular to the single fiber. The cross section of the fiber axis direction has a contact surface where the inner wall surfaces of the hollow portion are in contact with each other. The knitted fabric according to item 6 of the scope of patent application, wherein the crimped yarn is a multifilament with a crimp rate CC of 15% to 60%. The knitted fabric according to item 6 or item 7 of the scope of patent application has a basis weight of 50 g / m ² to 200 g / m ² and a cloth thickness of 0.2 mm to 0.5 mm. The knitted fabric according to item 6 or item 7 of the scope of patent application, wherein the crimped yarn is a false twisted yarn. The woven fabric according to item 6 or item 7 of the patent application scope, wherein the single fiber fineness of the crimped yarn is 1 dtex to 8 dtex, and the total fineness is 33 dtex to 250 dtex. The knitted fabric according to item 6 or item 7 of the scope of application for a patent, wherein the crimping response rate CR of the crimped yarn is 80% or more. The knitted fabric according to item 6 or item 7 of the scope of patent application has a heat insulation property of 41.5 ° C or lower and a Qmax of 0.22 or more. The knitted fabric according to item 6 or item 7 of the patent application scope, wherein the crimped yarn is arranged on one side of the fabric.