JP6420658B2 - Multifilament yarn and knitted fabric - Google Patents

Description

  The present invention relates to a multifilament yarn and a woven or knitted fabric.

  In order to obtain a woven or knitted fabric having excellent sunlight shielding properties, cool feeling and anti-through properties, it is known to use a filament yarn made of a synthetic resin containing inorganic oxide fine particles (for example, titanium oxide fine particles).

  However, when inorganic oxide fine particles are contained at a high concentration, many inorganic oxide fine particles are exposed on the surface of the filament yarn. The exposed inorganic oxide fine particles cause guide wear in the yarn making process or the weaving and knitting process, and deteriorate the process passability. In order to maintain the process passability, the inorganic oxide fine particles can be contained only at about 2% by mass, and in the woven or knitted fabric obtained from the filament yarn having a low content of the inorganic oxide fine particles, Insufficient see-through property.

  In order to solve the above problems, the core portion containing the inorganic oxide fine particles at a high concentration and the sheath portion not containing the inorganic oxide fine particles are composed of the core-sheath type composite fibers arranged concentrically. Woven and knitted fabrics are known. Such a core-sheath type composite fiber can improve to some extent the cool feeling and the see-through preventing property when made into a woven or knitted fabric while maintaining good processability.

  Further, a linear split type composite fiber is known in which a resin part containing no inorganic oxide fine particles is divided by a resin part containing inorganic oxide fine particles in a proportion of 5 to 30% by mass (for example, Patent Documents). 1). In this fiber, the resin part not containing the inorganic oxide fine particles occupies 50% or more of the area of the fiber cross section. In the fiber having such a configuration, the area through which sunlight passes is reduced, so that the cool feeling and the see-through prevention can be improved to some extent.

JP-A-5-247723

  However, in the core-sheath type composite fiber as described above, the composite shape of the fiber cross section is concentric, and the area through which sunlight passes in a portion not containing the inorganic oxide fine particles increases, Insufficient see-through property. Further, even in the linear split type composite fiber, the cool feeling and the anti-slipping property are insufficient.

  In order to enhance the sunlight shielding effect and improve the coolness and the prevention of see-through, it is conceivable to increase the area ratio of the resin portion containing the inorganic oxide fine particles. However, even if such a method is used, the amount of inorganic oxide fine particles exposed on the fiber surface is further increased, and thus the process passability problem such as guide wear cannot be solved.

  Furthermore, in a woven or knitted fabric using a linear split type composite fiber, the see-through preventing property when wet is insufficient. Therefore, when used for sports clothing or summer clothing, the sense of sheer changes greatly before and after sweating.

  The present invention solves the above problems, and has good spinning operability and good processability in the yarn production process and the weaving and knitting process, and when used in woven and knitted fabrics, It is a technical problem to provide a multifilament yarn excellent in see-through preventing property when wet, and a woven or knitted fabric made of the multifilament yarn.

  In the composite fiber as described in Patent Document 1, the cross-sectional shape of the resin portion containing the inorganic oxide fine particles at a high concentration is linear, and the cross-sectional shape of the fiber itself is round. Because it is a cross section, the reflection of sunlight incident on this resin part is simplified, and as a result, the diffuse reflection of sunlight is sufficient, and it has been determined that the anti-transparency when wet is insufficient. It was. And it discovered for the first time that the shape of the cross section of the single yarn contained in a multifilament yarn was made into a specific shape, and markedly improved see-through preventing performance when wet, and reached the present invention.

That is, the gist of the present invention is the following (1) to (10).
(1) A multifilament yarn composed of a plurality of single yarns including a first resin portion containing inorganic oxide fine particles and a second resin portion. The content of the inorganic oxide fine particles in the first resin part is more than 2% by mass and 10% by mass or less, and the content of the inorganic oxide fine particles in the second resin part is 2% by mass or less. The shape of the cross section with respect to the longitudinal direction of the single yarn satisfies the following (i) to (v).
(I) The shape of the second resin portion extends from the central portion of the single yarn to the outer peripheral side of the cross section so as to form the outer periphery of the cross section including the first resin portion. A multi-leaf shape having not less than 6 protrusions, and the shape of the first resin portion has a leaf portion extending from the center of the single yarn toward the tip of the protrusion, and The single yarn has a hollow portion.
(Ii) The shape of the distal end portion on the outer peripheral side of the leaf portion is a curved shape.
(Iii) The ratio of the exposed length of the first resin portion on the surface of the single yarn to the outer peripheral length of the single yarn is 10% or less.
(Iv) The average ratio of the shortest distance from the outer periphery of the single yarn to the leaf portion with respect to the distance from the center of the single yarn to the outer periphery of the single yarn is 10% or less.
(V) The hollow rate of the single yarn is 5 to 30%.

  The multifilament yarn of (1), wherein the resin constituting the first resin portion and the resin constituting the second resin portion are polyester resins.

  The mass ratio of the first resin part and the second resin part is (first resin part) / (second resin part) = 30/70 to 90/10, (1) or ( 2) Multifilament yarn.

  The multifilament yarn according to any one of (1) to (3), wherein the fineness of the single yarn is 0.5 to 10.0 dtex.

  A woven or knitted fabric comprising the multifilament yarn of any one of (1) to (4).

  The knitted or knitted fabric according to (5), wherein the cooling property is 2.0 or more.

  The woven or knitted fabric according to (5) or (6), which has an ultraviolet protection index of 30 or more.

The woven or knitted fabric according to any one of (5) to (7), wherein the degree of permeability reduction represented by the following formula (I) is 8.0% or less.
TF (%) = [(WId−WIw) / WId] × 100 (I)
In the above formula (I), WId indicates the whiteness of the sample when dried, and WIw indicates the whiteness of the sample when wet.

  The woven fabric according to any one of (5) to (8), which has a cover factor of 1000 to 3500.

  The knitted fabric according to any one of (5) to (8), wherein the cover factor is 500 to 2500.

  The multifilament yarn of the present invention has good spinning operability and process passability in the yarn making process and the weaving and knitting process, and also has a cool feeling when used in a woven or knitted fabric, UV protection, and see-through when wet. Excellent prevention. Furthermore, the knitted or knitted fabric of the present invention is excellent in coolness, UV protection, and see-through resistance when wet. Therefore, since the clothing made of the woven or knitted fabric of the present invention can reduce the change in sheer feeling before and after sweating, it is suitably used for sports clothing or summer clothing, for example.

It is the schematic which shows an example of the shape of the cross section with respect to the longitudinal direction of the single yarn contained in the multifilament yarn of this invention. It is a schematic diagram which shows an example of the shape of the cross section with respect to the longitudinal direction of the single yarn contained in the multifilament yarn obtained in the comparative example. It is a schematic diagram which shows an example of the shape of the cross section with respect to the longitudinal direction of the single yarn contained in the multifilament yarn obtained in the comparative example. It is a plane schematic diagram which shows the principal part of the apparatus for measuring the cooling property of the woven / knitted fabric of this invention. It is a schematic diagram which shows the cross section of A-A 'in the principal part of the apparatus for measuring the cooling property of the woven or knitted fabric of the present invention. It is a schematic diagram which shows the cross section of B-B 'in the principal part of the apparatus for measuring the cooling property of the woven / knitted fabric of this invention. It is a schematic diagram which shows an example of the shape of the cross section with respect to the longitudinal direction of the single yarn contained in the multifilament yarn obtained in the comparative example 10. It is a schematic diagram which shows an example of the shape of the cross section with respect to the longitudinal direction of the single yarn contained in the multifilament yarn obtained in the comparative example 9. It is a schematic diagram which shows an example of the shape of the cross section with respect to the longitudinal direction of the single yarn contained in the multifilament yarn obtained in Example 10. FIG.

Hereinafter, the present invention will be described in detail.
The multifilament yarn of the present invention is composed of a plurality of single yarns including a first resin portion and a second resin portion containing inorganic oxide fine particles. The content of the inorganic oxide fine particles in the first resin part is more than 2% by mass and 10% by mass or less, and the content of the inorganic oxide fine particles in the second resin part is 2% by mass or less. And the shape of the cross section with respect to the longitudinal direction of a single yarn satisfies the following (i)-(v).
(I) The shape of the second resin portion is a multi-leaf shape having 3 to 6 protrusions extending from the center side of the cross section to the outer peripheral side, and the shape of the first resin portion is the center portion of the single yarn The single yarn has a hollow portion and has a shape having a leaf portion extending toward the tip of the outer peripheral projection portion.
(Ii) The tip part on the outer peripheral side of the leaf part has a curved shape.
(Iii) The ratio of the exposed length of the first resin portion on the single yarn surface to the outer peripheral length of the single yarn is 10% or less.
(Iv) The average ratio of the shortest distance from the outer periphery of the single yarn to the leaf portion with respect to the distance from the center of the single yarn to the outer periphery of the single yarn is 10% or less.
(V) The hollow rate of the single yarn is 5 to 30%.

  The resin constituting the first resin part (first resin) and the resin constituting the second resin part (second resin) are not particularly limited as long as they can be melt-spun. Specifically, polyester resin (polyethylene terephthalate such as polyethylene terephthalate (PET), polybutylene terephthalate or polytrimethylene terephthalate), polyamide resin (nylon 6, nylon 66, nylon 46, nylon 11 or nylon 12), polyolefin Chemically polymerize resin (polypropylene or polyethylene), polychlorinated polymer (polyvinyl chloride or polyvinylidene chloride), fluorine-based polymer (polytetrafluoroethylene or its copolymer, or polyvinylidene fluoride) or biomass-derived monomer. Or a biomass polymer (PLA (polylactic acid), PTT (polytrimethylene terephthalate), or PBS (polybutylene succinate)). Of these, a polyester resin or a polyamide resin is preferable because of excellent spinning operation or processability.

  The first resin and the second resin are preferably resins having excellent compatibility with each other. When the resins are excellent in compatibility with each other, the first resin portion and the second resin portion are hardly separated even when subjected to a physical impact or a thermal impact in the yarn making process or the weaving and knitting process. . For example, when both the first resin and the second resin are polyester resins, they tend to be excellent in compatibility with each other, and can prevent peeling between the first resin portion and the second resin portion. This is preferable because the thermal stability of the obtained multifilament yarn is improved.

  Among the above resins, for example, for polyester resins, aromatic dicarboxylic acid (isophthalic acid or 5-sulfoisophthalic acid), aliphatic dicarboxylic acid (adipic acid, Succinic acid, suberic acid, sebacic acid or dodecanedioic acid), aliphatic diol (ethylene glycol, propylene glycol, 1,4-butanediol or 1,4-cyclohexanedimethanol), hydroxycarboxylic acid (glycolic acid, hydroxybutyric acid, Hydroxyvaleric acid, hydroxycaproic acid, hydroxypentanoic acid, hydroxyheptanoic acid or hydroxyoctanoic acid) or aliphatic lactone (ε-caprolactone) may be copolymerized.

  The inorganic oxide fine particles preferably have a high sunlight shielding effect, and specific examples thereof include fine particles of titanium oxide, calcium oxide, magnesium oxide, or zinc oxide. Of these, titanium oxide fine particles are preferable.

  The content of the inorganic oxide fine particles in the first resin part is more than 2% by mass and 10% by mass or less, preferably 3% by mass to 9% by mass, and more preferably 5% by mass to 8% by mass. When the content of the inorganic oxide fine particles is in the above range, the spinning operability is improved and the shape of the cross-section of the single yarn is the specific shape described later, thereby forming the multifilament yarn of the present invention. The woven or knitted fabric is excellent in cool feeling, ultraviolet ray prevention property and anti-slipping property when wet.

  The content of the inorganic oxide fine particles in the second resin part is 2% by mass or less. Thereby, the multifilament yarn of the present invention has good spinning operability and process passability in the yarn making process and the weaving and knitting process, and further has an excellent anti-slipping effect when made into a woven or knitted fabric. The content of the inorganic oxide fine particles in is more than 0% by mass and preferably 1% by mass or less, more preferably more than 0% by mass and 0.5% by mass or less.

  In addition to the inorganic oxide fine particles, the first resin and the second resin include a stabilizer (for example, an antioxidant), a fluorescent agent, a pigment, an antibacterial agent, an antibacterial agent, as long as the effects of the present invention are not impaired. An odorant, a matting agent, a reinforcing agent, or the like may be contained.

Regarding the single yarn constituting the multifilament yarn, the shape of the cross section with respect to the longitudinal direction (hereinafter sometimes referred to as “composite shape”) will be described below. In the present invention, a multifilament yarn having a synergistic effect due to the composite shape being a specific shape satisfying the above (i) to (v) and having significantly improved see-through preventing property when wet is produced. Can get well.
(I) will be described below. The shape of the second resin part includes 3 or more and 6 or less protrusions extending from the center of the single yarn to the outer peripheral side of the cross section so as to form the outer periphery of the cross section including the first resin part. It has a multi-leaf shape. These protrusions may be partly connected and the remainder separated by the first resin part.

  In addition, as illustrated in FIGS. 1A to 1D, the shape of the first resin portion in the composite shape is a leaf portion that extends radially from the center side of the single yarn 1 toward the tip of the protrusion on the outer periphery. 4. That is, the number of leaf parts 4 is the same as the number of the above-mentioned projection parts. The leaf portions 4 may exist separately (for example, FIGS. 1A, 1C, and 1D) or may be connected to each other (for example, FIG. 1B).

  In this specification, the leaf portion refers to a leaf having at least one end formed of a curve, and specific examples thereof include a shape such as a substantially rectangular shape, a substantially oval shape, or a substantially trapezoidal shape. Specifically, it is shown by the second resin part 2 (leaf part 4) in FIGS. In addition, the leaf portion does not need to be smooth in each side of, for example, a substantially rectangular shape, a substantially oval shape, or a substantially trapezoidal shape. For example, the leaf portion includes a minute convex portion and / or a concave portion or a wavy line. May be.

  The multifilament yarn of the present invention has a multi-leaf shape in which the shape of the second resin portion has 3 to 6 protrusions extending from the center portion of the single yarn to the outer peripheral side of the cross section. One incident sunlight can be reflected or refracted. And it combines with the diffuse reflection effect of the below-mentioned sunlight, and is excellent in the see-through prevention property at the time of wet when it is set as a woven or knitted fabric. Furthermore, since the air layer is formed between the plurality of single yarns as compared to the single yarn itself having a round cross-sectional shape, not only the air layer in the hollow portion but also the air layer outside the single yarn. There is also a synergistic effect that the anti-permeability, the coolness, and the ultraviolet protection when wet are remarkably improved.

  In the multifilament yarn of the present invention, since the shape of the first resin portion is a shape having leaf portions that radially extend from the center side of the single yarn toward the tip of the outer peripheral projection portion, the leaf portions adjacent to each other Can be made small. Furthermore, as the interval between the leaf portions becomes smaller, it becomes easier to repeat that the sunlight that has entered one of the leaf portions and diffusely reflected is further diffusely reflected by the adjacent leaf portions. And compared with what the cross-sectional shape of single yarn itself is a round cross-section, combined with the effect by providing the hollow part mentioned later, the see-through prevention property at the time of becoming wet when using a woven or knitted fabric further improves.

  (Ii) will be described below. The leaf portion needs to have a curved shape at the tip. When the tip is curved, the woven or knitted fabric made of the multifilament yarn of the present invention is excellent in see-through preventing property when wet. This is presumably because sunlight incident on the multifilament yarn causes diffuse reflection at the tip of the leaf portion having a curved shape.

  (Iii) will be described below. Regarding the single yarn constituting the multifilament yarn of the present invention, in the composite shape, the ratio (EC) of the exposed length (unit: μm) of the first resin portion to the surface of the single yarn in the outer peripheral length (unit: μm) is It must be 10% or less, and preferably 5% or less.

  When the EC value is 10% or less, spinning operability and process passability in the yarn making process and the weaving and knitting process are improved.

  (Iv) will be described below. Regarding the single yarn constituting the multifilament yarn of the present invention, the shortest distance from the outer periphery of the single yarn to the leaf portion relative to the distance (unit: μm) from the center of the single yarn to the outer periphery of the single yarn in each leaf portion of the composite shape The average ratio (DC) of distance (unit: μm) needs to be 10% or less, and preferably 5% or less.

  If the value of DC exceeds 10%, the area sandwiched between the leaf part and the outer periphery of the single yarn becomes large, so that sunlight is easily transmitted. As a result, the amount of sunlight passing through this region increases, and when the multifilament yarn of the present invention is used as a woven or knitted fabric, it is inferior in coolness, anti-ultraviolet rays, and anti-transparency when wet.

  The EC and DC values can be controlled by appropriately adjusting the spinning conditions (for example, the shape of the spinning nozzle, the viscosity of the resin, or the spinning temperature).

  The single yarn constituting the multifilament yarn of the present invention has a hollow portion. And the hollow rate (area of the hollow part with respect to the total area of a cross section) of a single yarn needs to be 5-30%, and 10-20% is preferable. Moreover, it is preferable that a hollow part is distribute | arranged to the center part of a single yarn from a viewpoint of spinning operation property and uniform see-through prevention property.

  The hollow ratio can be measured by the following method. Using an optical microscope (“PCSCOPE PCS-81X” manufactured by INABATA & CO), the magnification is adjusted to 10 to 20 times and a photograph of a cross section of the single yarn is taken. Then, the cross-sectional photograph is enlarged so that the single yarn diameter is about 10 to 20 mm, the single yarn diameter (unit: μm), the length of the long axis of the hollow portion (unit: μm), and the short axis of the hollow portion The length (unit: μm) is measured. And a hollow rate is computed by following formula (II).

Hollow ratio (%) = [{(r1) ² + (r2) ² } / 2R ² ] × 100 (II)
In the above formula (II), r1 represents the length of the long axis of the hollow part, r2 represents the length of the short axis of the hollow part, and R represents the diameter of the cross section of the single yarn.

  The hollow ratio can be controlled by appropriately adjusting the spinning conditions (for example, the shape of the spinning nozzle, the viscosity of the resin, or the spinning temperature).

  The multifilament yarn of the present invention is composed of a single yarn having a specific multi-leaf shape in a cross section and having a hollow portion having a specific occupation area. Due to the synergistic effect of such a configuration, the conventional core-sheath conjugate fiber (see FIG. 2 (a)), linear split-type conjugate fiber (see FIG. 2 (b)), and the first resin portion are excessively exposed on the surface of the single yarn. Compared with a composite fiber (see FIG. 3A), a composite fiber in which the first resin part does not form a leaf part (see FIG. 3B), or a composite fiber having no hollow part, In this case, it is remarkably excellent in cool sensation, UV protection, and see-through resistance when wet. This is because the refractive index of the air layer contained in the hollow portion is different from the refractive index of the first resin portion and / or the second resin portion, so that the sunlight incident on the single yarn is the hollow portion. This is presumably due to a synergistic effect of refraction.

  When the hollow ratio is less than 5%, the occupied area of the hollow portion in the cross section of the single yarn becomes too small. Therefore, the effect due to the difference in refractive index between the air layer and the first resin part and / or the second resin part is not sufficiently exhibited, and cool sensation when used as a woven or knitted fabric, UV protection, and prevention of see-through when wet Inferior to sex. On the other hand, if the hollow ratio exceeds 30%, the hollow portion is crushed and disappears or peels off in the yarn making process or the post-processing process, which causes fibrillation or whitening.

  In the composite shape, the shape of the first resin portion is preferably rotationally symmetric. Here, the “rotationally symmetric shape” means “a shape that overlaps the original shape (the shape before the rotation) when rotated at a certain angle around the center point of the cross section of the single yarn”. When the shape of the first resin portion is rotationally symmetric, the single yarn spun from the spinning nozzle is prevented from exhibiting a phenomenon of so-called yarn bending when spinning a single yarn, and stable spinnability and Good yarn quality can be achieved. Moreover, since it becomes difficult to produce a deviation in the shielding property of the first resin portion that contributes to the see-through preventing property, uniform see-through preventing property is easily obtained when the single yarn is viewed from various angles.

  The mass ratio of the first resin part to the second resin part (first resin part / second resin part) is preferably 30/70 to 90/10, and 60/40 to 80/20. It is more preferable that

  When the mass ratio is 30/70 or more, the woven or knitted fabric made of the multifilament yarn of the present invention is particularly excellent in cool feeling, ultraviolet ray prevention property, and see-through prevention property when wet. When the mass ratio is 90/10 or less, the spinning operability and the process passability in the yarn making process and the weaving and knitting process are improved. When this mass ratio is 60/40 to 80/20, while maintaining good spinning operability and process passability in the yarn making process and the weaving and knitting process, the coolness of the knitted and knitted fabric, the UV protection and the wetness Especially excellent in prevention of see-through.

  The single filament fineness of the multifilament yarn of the present invention is preferably 0.5 to 10 dtex, more preferably 0.5 to 3 dtex, and further preferably 0.5 to 2 dtex. It is presumed that the smaller the single yarn fineness, the flatter the surface of the fabric during weaving and knitting, and the higher the sunlight reflection effect. If the single yarn fineness is less than 0.5 dtex, the spinnability may be deteriorated. On the other hand, if the single yarn fineness exceeds 10 dtex, the texture of the fabric becomes hard, which is not preferable.

  The number of single yarns contained in the multifilament yarn is preferably larger in order to enhance the effect of diffuse reflection of sunlight by the multifilament yarn, more preferably 10 to 200, and more preferably 20 to 100. Further preferred.

  The multifilament yarn of the present invention may be processed yarn as long as the hollow portion does not disappear or peel off and does not impair the effects of the present invention. In order to obtain a processed yarn, for example, real twist processing, loop processing, or interlace processing can be performed.

  The woven or knitted fabric of the present invention composed of the multifilament yarn of the present invention as described above has excellent coolness and UV protection, and is excellent in see-through resistance even if the woven or knitted fabric is moistened by perspiration or the like.

  The cooling property (CT) of the woven or knitted fabric of the present invention is preferably 2.0 or more, more preferably 2.5 or more, and further preferably 3.0 or more. A higher CT value indicates that the woven or knitted fabric is more excellent in coolness.

  In order to increase the CT in the woven or knitted fabric of the present invention, for example, the multifilament yarn of the present invention itself has a high sun shielding property, the mixed rate of the multifilament yarn or the cover factor of the woven or knitted fabric described later is appropriate. Or control within a certain range.

  The UV prevention index (UPF) of the woven or knitted fabric of the present invention is preferably 30 or more, and more preferably 40 or more. UPF is calculated as follows. According to the Australian New Zealand standard (AS / NZS; 4399: 1996), an ultraviolet transmission in the range of 280 to 400 nm is measured using a spectrophotometer. This is calculated in consideration of a predetermined damage coefficient. The UPF indicates that the higher the numerical value, the greater the UV protection. In particular, when the UPF value is 30 or more, the grade becomes “Very good protection” or more, and the effect of protecting the skin from ultraviolet rays and preventing damage is further enhanced. In order to improve the numerical value of UPF, for example, the sun-shielding property of the multifilament yarn itself is increased, or the mixture ratio or cover factor described later is adjusted to an appropriate range.

The woven or knitted fabric of the present invention preferably has a permeation reduction degree (TF) represented by the following formula (I) of 8.0% or less, more preferably 7.0% or less, and 6.0% or less. Is more preferable. A TF of 8.0% or less is an indicator of good anti-penetration when wet.
TF (%) = [(WId−WIw) / WId] × 100 (I)
In the above formula (I), WId indicates the whiteness of the sample when dried, and WIw indicates the whiteness of the sample when wet.

  Specifically, WId and WIw are numerical values obtained by measuring the tabe whiteness using a spectrophotometer (for example, “MS-2020 type” manufactured by Macbeth). In addition, the sample at the time of drying is a sample (woven or knitted fabric) left to stand for 24 hours in an environment of 20 ° C. and 65% RH. The wet sample refers to a sample that is allowed to stand for 24 hours in an environment of 20 ° C. and 65% RH and that contains the same amount of moisture as the sample.

  In order to adjust the TF of the woven or knitted fabric of the present invention to 8.0% or less, for example, the multifilament yarn of the present invention is adjusted so as to enhance the see-through preventing property when wet, and will be described later. It is possible to adopt a method of controlling the mixed rate or the cover factor within an appropriate range.

  In the woven or knitted fabric of the present invention, the mixed rate of the multifilament yarn of the present invention is preferably 25% by mass or more, more preferably 30% by mass or more, and further preferably 40% by mass or more. When the mixing ratio is 25% by mass or more, it is excellent in cool sensibility, ultraviolet ray prevention property, and anti-translucency property when wet. In order to sufficiently block sunlight, it is preferable to set the above-mentioned mixed rate to 100% by mass. Examples of the mixing method include mixed spinning, twisting or knitting.

  Moreover, when the woven or knitted fabric of the present invention is a woven fabric, the cover factor (CF) is preferably 1000 to 3500, and more preferably 1500 to 2500. Moreover, when the woven or knitted fabric of the present invention is a knitted fabric, the CF is preferably 500 to 2500, and more preferably 800 to 1800. Here, CF is calculated by the following formula (III) in the case of a woven fabric, and is calculated by the following formula (IV) in the case of a knitted fabric.

CF = WAD × √DT + WED × √DT (III)
CF = CD × √DT + WD × √DT (IV)

In the above formulas (III) and (IV), abbreviations indicate the following.
DT: Fineness of multifilament yarn (dtex)
WAD: Warp density (main / 2.54cm)
WED: Weft density (main / 2.54cm)
CD: Course density (book / 2.54cm)
WD: Wale density (book / 2.54cm)

  In addition, the calculation of the fineness of the multifilament yarn is JIS L 1096: 2010 8.9.9.1. Follow method A of a. Similarly, in the case of a knitted fabric, JIS L 1096: 2010 8.9.9.1. Follow b. The calculation of the warp density and the weft density follows the JIS L 1096: 2010 8.6.1A method. The calculation of the course density and the wale density follows JIS L 1096: 2010 8.6.2.

  When the value of CF satisfies the above range, the woven or knitted fabric of the present invention is excellent in coolness, anti-ultraviolet rays, and anti-translucency when wet.

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

Measurement and evaluation in the following examples and comparative examples were performed by the following methods.
(1) Intrinsic viscosity [η]
Using an equal mass mixture of phenol and ethane tetrachloride as a solvent, the measurement was carried out according to a conventional method under a temperature of 20 ° C.

(2) Ratio (EC) of the exposed length (μm) of the first resin portion on the surface of the single yarn to the outer peripheral length (μm) of the single yarn
One single yarn was collected from the multifilament yarn. The cross section of this single yarn in the longitudinal direction was observed with an optical microscope (manufactured by INABATA & CO, “PCSCOPE PCS-81X”), and the outer peripheral length (μm) of the single yarn and the exposure on the surface of the single yarn of the first resin portion The length (μm) was measured. EC (%) was calculated by the following formula.
EC (%) = (exposed length of first resin portion / periphery length of single yarn) × 100

(3) The average ratio (DC) of the shortest distance (μm) from the outer periphery of the single yarn to the leaf portion relative to the distance (μm) from the center of the single yarn to the outer periphery of the single yarn
One single yarn was collected from the multifilament yarn. Observe the cross-section of this single yarn in the longitudinal direction with the above optical microscope and measure the distance from the center of the single yarn to the outer periphery of the single yarn (μm) and the shortest distance from the outer periphery of the single yarn to each leaf (μm). did. Then, DC (%) was calculated by the following formula.
DC (%) = (average value of the shortest distance from the outer periphery of the single yarn to each leaf portion / distance from the center of the single yarn to the outer periphery of the single yarn) × 100

(4) Hollow ratio The hollow ratio was measured as follows. Using the above optical microscope, the cross-sectional photograph of the single yarn is enlarged so that the diameter is about 10 to 20 mm, the single yarn diameter (unit: μm), the length of the long axis of the hollow portion (unit: μm) ), The length (unit: μm) of the short axis of the hollow portion was measured. And the hollow ratio was computed by following formula (II).
Hollow ratio (%) = [{(r1) ² + (r2) ² } / 2R ² ] × 100 (II)
In the above formula (II), r1 represents the length of the long axis of the hollow part, r2 represents the length of the short axis of the hollow part, and R represents the diameter of the single yarn.

(5) Cooling property (CT)
The cooling property (CT) of the woven or knitted fabric was measured using the apparatus shown in FIGS. 4 is a schematic plan view showing the main part of the apparatus, FIG. 5 is a schematic diagram of the AA ′ cross section in the apparatus shown in FIG. 4, and FIG. 6 is a BB ′ in the apparatus shown in FIG. It is a schematic diagram of a cross section. As shown in FIGS. 4 and 5, this apparatus has holes 13a and 13b (all 8 cm in length, 8 cm in width, and 0.7 cm in depth) on the upper surface side of the polystyrene foam 12 having a height of 20 cm. Thermocouples 15a and 15b were provided at the center of the bottom of 13a and 13b.

  The woven or knitted material to be measured was cut into a square (size: the length of one side was 10 cm) to obtain a woven or knitted fabric 14a. This woven or knitted fabric 14a was attached to the upper surface of the polystyrene foam 12 so as to cover one hole 13a. Woven knitted fabric 14b was used as a blank woven or knitted fabric. The woven or knitted fabric 14b had the same structure as the woven or knitted fabric to be measured. The woven or knitted fabric 14b had the same single yarn fineness and the same number of filaments as the multifilament yarn, and consisted of a PET multifilament yarn composed of a single component containing 0.4% by mass of titanium oxide fine particles. This woven or knitted fabric 14b was pasted so as to cover the other hole 13b in the same manner as the woven or knitted fabric 14a to be measured. Then, as shown in FIG. 6, the apparatus was installed outdoors so that the surface on which the woven or knitted fabric was attached faced in the horizontal direction. After 15 minutes from the installation, the temperature (T1 (° C.)) of the thermocouple 15a provided in the hole 13a (the hole to which the measurement target woven or knitted fabric 14a is attached) and the hole 13b (the hole to which the blank woven or knitted item 14b is attached). ) Was measured with the temperature (T2 (° C.)) of the thermocouple 15b provided in FIG. And the difference (T2-T1) (degreeC) of these temperature was set to CT. As measurement conditions, the illuminance on the surfaces of the woven and knitted fabric 14a and 14b was set to 100000 lux.

(6) UV protection index (UPF)
According to the Australian New Zealand standard (AS / NZS; 4399: 1996), the ultraviolet transmittance of 280 to 400 nm was measured using a spectrophotometer. This was calculated in consideration of a predetermined damage coefficient.

(7) Permeability reduction degree (TF)
A spectrophotometer (manufactured by Macbeth, “MS-2020”) was used to measure the whiteness (WId) of the sample when dried and the whiteness (WIw) of the sample when wet. It calculated by the following formula (I). The dry sample was a sample (woven or knitted fabric) that was allowed to stand for 24 hours in an environment of 20 ° C. and 65% RH. The wet sample was a sample in which the sample was allowed to stand for 24 hours in an environment of 20 ° C. and 65% RH, and contained the same amount of moisture as this sample.

TF (%) = [(WId−WIw) / WId] × 100 (I)

(8) Cover factor The cover factor (CF) of the knitted fabric was calculated by the following formula (IV).
CF = CD × √DT + WD × √DT (IV)
Abbreviations in the above formula (IV) indicate the following.
DT: Fineness of multifilament yarn (dtex)
CD: Course density (book / 2.54cm)
WD: Wale density (book / 2.54cm)

  The fineness of the multifilament yarn is calculated according to JIS L 1096: 2010 8.9.9.1. b was followed. Moreover, calculation of a course density and a wale density followed JIS L 1096: 2010 8.6.2.

(9) Spinning operability Spinning was performed continuously for 24 hours, and the following three stages were evaluated based on the number of cut yarns (number of times per spindle) during the spinning operation. In the present invention, “good” is regarded as acceptable.
○: The number of cut yarns during operation is 0 to 1 times.
(Triangle | delta): The frequency | count of cut yarn in operation is 2-3 times.
X: The number of cut yarns during operation is 4 or more.

(10) Process passability Before knitting the knitted fabric, 10 knitting needles of the knitting machine that are free from scratches or wear were randomly selected. And after knitting, the knitting needle selected beforehand was observed with the optical microscope, and the following references | standards evaluated.
○: Scratches or wear were not observed in all 10 knitting needles.
X: Scratches or wear was observed on one or more of the 10 knitting needles.

(11) Texture The knitted fabric obtained in Examples and Comparative Examples was touched by 10 testers. The texture was evaluated according to the following criteria.
A: 0 to 2 testers evaluated that the texture of the knitted fabric was hard.
Δ: 3 to 5 testers evaluated that the texture of the knitted fabric was hard.
X: Six or more testers evaluated that the texture of the knitted fabric was hard.

Example 1
PET (intrinsic viscosity: 0.65) was made into a chip by a conventional method and then dried to obtain a PET chip. Titanium oxide fine particles (TiO ₂ ) as inorganic oxide fine particles were added to the PET chip at a ratio of 3.0% by mass to obtain a first resin. Further, titanium oxide fine particles (TiO ₂ ) were added to the PET chip at a ratio of 0.4% by mass to obtain a second resin.

  Using the first resin and the second resin, a multifilament was spun using a conventional compound spinning device (spinning temperature: 295 ° C.). At the time of spinning, the mass ratio (first resin / second resin) of both is 75/25, and the composite shape is the shape shown in FIG. 1 (c) (number of protrusions and leaves: 3). A nozzle was used. Then, the spun multifilament was cooled, and an oil agent was applied to the surface thereof, and then taken up by a take-up roller at a speed of 3000 m / min. Next, the film was drawn at a temperature of 90 ° C. and a draw ratio of 1.50, and heat treated at a temperature of 140 ° C. to obtain a multifilament yarn of Example 1 (fineness: 90 dtex, number of single yarns: 48, single yarn fineness: 1.88 dtex). In addition, EC, DC, and hollow ratio in the composite shape were measured and calculated using this multifilament yarn. The EC value was 0% (that is, it was not confirmed that the first resin portion was exposed on the surface of the single yarn), the DC value was 4.2%, and the hollowness was 15%. .

Using only the obtained multifilament yarn, a circular knitting machine was used to obtain knitted fabrics having a smooth structure of 51 wal / 2.54 cm and 63 course / 2.54 cm. Thereafter, scouring was conducted by a conventional method, and dyeing was performed at a temperature of 130 ° C. for 30 minutes using the following formulation.
Dye (Nippon Ciba-Geigy Co., Ltd., “UVITEX EBF”): 1% omf
Auxiliary agent (manufactured by Nikka Chemical Co., Ltd., “Nikka Sun Salt SN-130”): 0.5 g / L
Acetic acid: 0.2 mL / L

  Finishing was performed after dyeing to obtain a knitted fabric of Example 1. CT, UPF, TF and CF were measured and calculated using this knitted fabric.

(Examples 2 and 3)
A multifilament yarn and a knitted fabric were obtained in the same manner as in Example 1 except that the content of the titanium oxide fine particles in the first resin part was changed as shown in Table 1.

Example 4
A multifilament yarn and a knitted fabric are obtained by performing the same operation as in Example 1 except that the content of the titanium oxide fine particles in the first resin portion and the second resin portion is changed as shown in Table 1, respectively. It was.

(Example 5)
PET having an intrinsic viscosity of 0.65 was chipped by a conventional method and dried to obtain a PET chip. Titanium oxide fine particles (TiO ₂ ) as inorganic oxide fine particles were added to this PET so as to have a ratio of 5.0% by mass to obtain a first resin. Further, fine particles of titanium oxide (TiO ₂ ) were added to this PET so as to have a ratio of 0.4% by mass to obtain a second resin.

  The first resin and the second resin were spun into multifilaments using a conventional compound spinning apparatus (spinning temperature 295 ° C.). When spinning, the mass ratio (first resin / second resin) of both is 75/25, and the composite shape is as shown in FIG. 1 (d) (number of protrusions and leaves: 3). ) Was used. Then, the spun multifilament was cooled, and an oil agent was applied to the surface thereof, and then taken up by a take-up roller at a speed of 3000 m / min. Next, the film was drawn at a temperature of 90 ° C. and a draw ratio of 1.50, and heat-treated at a temperature of 140 ° C. to obtain a multifilament yarn of Example 1 (fineness: 90 dtex, number of single yarns: 48, single yarn fineness: 1.88 dtex). EC, DC, and hollow ratio were measured and calculated using this multifilament yarn. The EC value was 0% (that is, it was not confirmed that the first resin portion was exposed on the surface of the single yarn), the DC value was 3.8%, and the hollowness was 15%. .

Using only the obtained multifilament yarn, a knitted fabric of 49 wal / 2.54 cm and 53 course / 2.54 cm was obtained as a smooth structure by a circular knitting machine. Thereafter, scouring was conducted by a conventional method, and dyeing was performed at a temperature of 130 ° C. for 30 minutes using the following formulation.
Dye (Nippon Ciba-Geigy Co., Ltd., “UVITEX EBF”): 1% omf
Auxiliary agent (manufactured by Nikka Chemical Co., Ltd., “Nikka Sun Salt SN-130”): 0.5 g / L
Acetic acid: 0.2 mL / L

  After dyeing, finishing was performed to obtain a knitted fabric of Example 5. CT, UPF, TF and CF were measured and calculated using this knitted fabric.

(Example 6)
A multifilament yarn and a knitted fabric of Example 6 were obtained in the same manner as in Example 1 except that the hollow ratio in the single yarn was changed to 30% by changing the spinning nozzle.

(Example 7)
A multifilament yarn and a knitted fabric of Example 7 were obtained in the same manner as in Example 1 except that the hollow ratio in the single yarn was changed to 5% by changing the spinning nozzle.

(Example 8)
A multifilament yarn and a knitted fabric of Example 8 were obtained by performing the same operation as in Example 2 except that the EC in the single yarn was changed to 10% by changing the spinning nozzle.

Example 9
A multifilament yarn and a knitted fabric of Example 9 were obtained by performing the same operation as in Example 5 except that the spinning nozzle was changed so that the DC in the single yarn was 10%.

(Example 10)
By changing the spinning nozzle, the same operation as in Example 2 was performed except that the composite shape of the single yarn was changed to the shape shown in FIG. 9 (the shape in which the number of protrusions and leaves was 6). The multifilament yarn and the knitted fabric of Example 10 were obtained.

(Comparative Example 1)
A multifilament yarn and a knitted fabric of Comparative Example 1 were obtained in the same manner as in Example 1, except that the content of the titanium oxide fine particles in the first resin part was changed to 1.5% by mass.

(Comparative Example 2)
Although the same operation as in Example 1 was performed except that the content of the titanium oxide fine particles in the first resin part was changed to 12.0% by mass, the multifilament yarn of Comparative Example 2 was obtained. I couldn't.

(Comparative Example 3)
By changing the spinning nozzle, the composite shape of the single yarn is changed to the shape shown in FIG. 2B (composite shape in which the first resin portion 10 is divided by the second resin portion 11), and is linear. A multifilament yarn and a knitted fabric of Comparative Example 3 were obtained in the same manner as in Example 2 except that the split composite fiber 9 was used.

(Comparative Example 4)
By changing the spinning nozzle, the composite shape of the single yarn is the shape shown in FIG. 2A (the first resin portion 7 is arranged on the core portion, and the second resin portion 8 is arranged on the sheath portion). The multifilament yarn and the knitted fabric of Comparative Example 4 were obtained by performing the same operation as in Example 2 except that the core-sheath type composite fiber 6 was obtained.

(Comparative Example 5)
The multifilament yarn and knitted fabric of Comparative Example 5 were obtained by performing the same operation as in Example 5 except that the composite shape of the single yarn was changed to the shape shown in FIG. 3A by changing the spinning nozzle. It was.

(Comparative Example 6)
A multifilament yarn and a knitted fabric of Comparative Example 6 were obtained in the same manner as in Example 1 except that the hollow rate in the single yarn was changed to 3% by changing the spinning nozzle.

(Comparative Example 7)
The same procedure as in Example 1 was performed except that the hollow ratio of the single yarn was changed to 40% by changing the spinning nozzle to obtain the multifilament yarn of Comparative Example 7, but spinning was performed. I couldn't.

(Comparative Example 8)
The multifilament yarn and the knitted fabric of Comparative Example 8 were obtained by performing the same operation as in Example 2 except that the composite shape of the single yarn was changed to the shape shown in FIG. 3B by changing the spinning nozzle. It was.

(Comparative Example 9)
By changing the spinning nozzle, the same operation as in Example 1 was performed except that the composite shape of the single yarn was changed to the shape shown in FIG. 8 (a shape in which the number of protrusions and leaves was 20). As a result, a multifilament yarn and a knitted fabric of Comparative Example 9 were obtained.

(Comparative Example 10)
As the second resin, an alkali-soluble polyester resin having an intrinsic viscosity of 0.73 (polyethylene glycol (PEG) having an average molecular weight of 8000, 2.5 mol% of 5-sodium sulfoisophthalic acid (SIP-Na) with respect to the polyester resin) A product obtained by copolymerizing 13.3 mass%) into a chip by a conventional method and drying it was used. And the same operation as Example 1 is performed except performing the alkali treatment after knitting and dissolving and removing the alkali-soluble polyester resin, and the shape of the single yarn of Comparative Example 10 is the shape shown in FIG. Multifilament yarn and knitted fabric were obtained. CT, UPF, TF and CF were measured and calculated using this knitted fabric.

The evaluation results of the obtained knitted fabric are shown in Table 1.

  As shown in Table 1, the knitted fabrics obtained in Examples 1 to 10 have excellent coolness and UV protection, and excellent anti-slipping properties even when wet with sweating. It was clear to have. In particular, in Examples 2 to 5, since the content of the titanium oxide fine particles in the first resin portion was 5 to 8% by mass, it was particularly excellent in both the coolness and the see-through property when wet. . In Example 2, the DC value was 4.1%, whereas in Example 9, the DC value was 10.0%. From this result, the knitted fabric obtained in Example 2 has particularly excellent CT, UPF and TF values as compared with the knitted fabric obtained in Example 9, and has a cool feeling, UV protection and wetness. It was clear that it was particularly excellent in the prevention of see-through.

  In Comparative Example 1, since the content of the titanium oxide fine particles in the first resin part was less than 2% by mass, the obtained knitted fabric had values of CT, UPF, and TF that were outside the preferred range of the present invention, and was cool. In addition, it was inferior in ultraviolet ray prevention and wet-through prevention properties.

  In Comparative Example 2, the content of the titanium oxide fine particles in the first resin portion exceeded 10% by mass, so that spinning could not be performed, and multifilament yarn and knitted fabric could not be obtained.

  In Comparative Example 3, the composite shape of the single yarn constituting the multifilament yarn was the shape shown in FIG. 2B, and the EC value exceeded 10%. Therefore, it was inferior to the spinning operability of the multifilament yarn and process passability in the yarn making process and the knitting process. In addition, since the shape of the first resin portion does not include a curved portion and is composed only of a straight portion, the obtained knitted fabric has a TF value that is outside the preferred range of the present invention, and is inferior in see-through prevention when wet. .

  In Comparative Example 4, the composite shape of single yarns constituting the multifilament yarn was the shape shown in FIG. 2A, and the DC value exceeded 10% (13.1%). For this reason, the area through which sunlight can be transmitted in the second resin portion becomes large, and the obtained knitted fabric has CT and TF values that are out of the preferred range of the present invention, and is inferior in coolness and anti-transparency when wet. It was.

  In Comparative Example 5, since the EC value exceeded 10% (15%), the obtained multifilament yarn was inferior in spinning operability and process passability.

  In Comparative Example 6, since the hollowness was less than 5%, the obtained knitted fabric had UPF and TF values outside the preferred range of the present invention, and was inferior in ultraviolet ray prevention and wet-through prevention properties. .

  In Comparative Example 7, since the hollow ratio exceeded 30%, the hollow portion was peeled off or crushed in most of the single yarns constituting the multifilament yarn. As a result, the yarn forming property was remarkably deteriorated, so that the multifilament yarn could not be stably spun and a knitted product could not be obtained.

  In Comparative Example 8, the first resin portion of the single yarn was a core-sheath type having no leaf portion (FIG. 3B), and the DC value greatly exceeded 10% (72.1%). For this reason, the obtained knitted fabric was inferior in coolness and the see-through preventing property when wet because the values of CT and TF were outside the preferred range of the present invention.

  In Comparative Example 9, as shown in FIG. 8, the number of leaf portions in the single yarn composite shape was 20, and the composite shape was close to a round cross section. For this reason, the values of CT and UPF deviated from the preferred range of the present invention, and the coolness and UV protection were inferior.

  In Comparative Example 10, a polyester resin, which is an alkali-soluble component, is disposed on the second resin portion, and the second resin portion is dissolved and removed after forming a knitted fabric. It was a thread. Therefore, the values of CT and TF deviated from the preferred range of the present invention, and the coolness and the anti-slipping property when wet were inferior.

DESCRIPTION OF SYMBOLS 1 Single yarn 2 First resin part 3 Second resin part 4 Leaf part 5 Hollow part 6 Core-sheath type composite fiber 7 First resin part 8 Second resin part 9 Linear split type composite fiber 10 First Resin part 11 Second resin part 12 Styrofoam 13a, 13b Hole 14a Woven knitted fabric 14b Blank knitted fabric 15a, 15b Thermocouple

Claims (9)

A multifilament yarn composed of a plurality of single yarns including a first resin portion and a second resin portion containing inorganic oxide fine particles,
The content of the inorganic oxide fine particles in the first resin part is more than 2% by mass and 10% by mass or less,
The content of the inorganic oxide fine particles in the second resin part is 2% by mass or less,
The multifilament yarn, wherein the shape of the cross section with respect to the longitudinal direction of the single yarn satisfies the following (i) to (v):
(I) The shape of the second resin portion extends from the central portion of the single yarn to the outer peripheral side of the cross section so as to form the outer periphery of the cross section including the first resin portion. A multi-leaf shape having not less than 6 protrusions, and the shape of the first resin portion has a leaf portion extending from the center of the single yarn toward the tip of the protrusion, and The single yarn has a hollow portion.
(Ii) The shape of the distal end portion on the outer peripheral side of the leaf portion is a curved shape.
(Iii) The ratio of the exposed length of the first resin portion on the surface of the single yarn to the outer peripheral length of the single yarn is 10% or less.
(Iv) The average ratio of the shortest distance from the outer periphery of the single yarn to the leaf portion with respect to the distance from the center of the single yarn to the outer periphery of the single yarn is 10% or less.
(V) The hollow rate of the single yarn is 5 to 30%.   The multifilament yarn according to claim 1, wherein the resin constituting the first resin portion and the resin constituting the second resin portion are polyester resins.   The mass ratio between the first resin part and the second resin part is (first resin part) / (second resin part) = 30/70 to 90/10, The multifilament yarn according to claim 1 or 2.   The multifilament yarn according to any one of claims 1 to 3, wherein the fineness of the single yarn is 0.5 to 10.0 dtex.   A woven or knitted fabric comprising the multifilament yarn according to any one of claims 1 to 4. The woven or knitted fabric according to claim 5 , wherein the ultraviolet ray prevention index is 30 or more. The knitted or knitted fabric according to claim 5 or 6 , wherein the degree of permeation reduction represented by the following formula (I) is 8.0% or less.
TF (%) = [(WId−WIw) / WId] × 100 (I)
In the above formula (I), WId indicates the whiteness of the sample when dried, and WIw indicates the whiteness of the sample when wet. The woven fabric according to any one of claims 5 to 7 , wherein the cover factor is 1000 to 3500. The knitted fabric according to any one of claims 5 to 7 , wherein the cover factor is 500 to 2500.

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