JP2007162158A - Knitted fabric - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a knitted fabric that is constituted with multilobular cross-sectional filaments formed by the elution processing and have each a sharp multilobular cross section, as it retains light weight, thinness, softness and mild and graceful gloss, thus giving dry skin touch and bursting strength. <P>SOLUTION: This knitted fabric comprises at least more than 30 wt.% of multilobular cross-sectional filament in which the cross section has three or more leaves 1 having the leaf top pont angle α less than 90 degree. Further, the knitted fabric has a burst strength of more than 250 kPa and a unit weight of less than 130 g/m<SP>2</SP>. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a knitted fabric that is light, thin and soft, and has a mild, elegant luster and a smooth feel with excellent bursting strength characteristics.

Conventionally, knitted fabrics have been widely used for inner use, sports use, sweaters and the like because of their excellent stretchability. However, it is difficult to reduce the thickness and weight of the fabric because it is structurally bulkier than the fabric. Until now, hollow fibers have been frequently used to reduce the weight of knitted fabrics. For example, Patent Document 1 discloses a method for producing hollow fibers by a spinneret as a method for producing hollow fibers, and Patent Document 2 discloses a method for producing hollow fibers by producing a core-sheath composite yarn and then removing the core portion after elution. Are listed. In any case, the weight can be reduced to some extent, but it becomes bulky and does not have both weight reduction and thinning. In addition, various types of knitted fabrics using irregular cross-section yarns have been studied in order to obtain gloss, and many studies have been conducted on multi-leaf cross-section yarns. Immediately after the viscosity of the polymer was low, the cross-sectional shape was rounded and the glossiness was poor.
On the other hand, Patent Document 3 describes a filament yarn having a controlled cross-sectional shape obtained from a core-sheath type composite yarn containing an elution component. However, a lightweight knitted fabric having a high bursting strength is not disclosed.
Japanese Patent No. 3653842 JP 2005-42222 A JP 2003-313721 A

  In light of the background of the prior art, the present invention is a lightweight, thin, soft, knitted fabric that has a mild, elegant luster and a smooth feel with excellent sharp bursting properties due to the sharp multileaf cross-section yarn obtained by elution Is intended to provide.

  The present invention employs the following means in order to solve such problems.

That is, the multi-leaf cross-sectional filament yarn is a knitted fabric containing at least 30% by weight or more, and the shape of the multi-lobe cross-section is a shape having three or more leaves whose angle α formed by the apex of the leaf is 90 degrees or less The knitted fabric satisfies the following formulas (1) to (2), has a bursting strength of 250 kPa or more and a basis weight of 130 g / m ² or less.
(1) 0.5r ≦ a _max
(However, the circumscribed circle radius of the filament cross-section is r, and two points B _i (common to C _i-1 ) and C _i (common to B _{i + 1} ) each leaf of the filament cross-section shares with the adjacent leaf) the longest of the line segments are connected by apexes T _i of each leaf was a _max.)
(2) Σ2S _i / K _i L _i N ≦ 1.7
(However, the length of a line segment B _i C _i connecting two points B _i (common to C _i-1 ) and C _i (common to B _{i + 1} ) that each leaf of the filament cross-section configures with the adjacent leaf is defined as K and _i, the area of a portion where each leaf is cut at the line segment _B i _{C i} and _{S i,} the distance between the midpoint of the vertices _{T i} and the line segment _B i _{C i} of each lobe and _{L i.} the filament cross The number of leaves on the face is N.)
Further, the multi-leaf cross-sectional filament yarn of the present invention is composed of a polyamide fiber produced by dissolving the sheath component of the core-sheath composite yarn, and the composite ratio of the core-sheath multi-leaf cross-section filament yarn is in a weight ratio, Core component: sheath component = 30: 70 to 50:50.
The multifilamentary cross-section filament yarn has a total fineness of 10 to 75 dtex, a single fiber fineness of 0.5 to 4.0 dtex, a first knitted fabric well of 40 to 85 / 2.54 cm, and a course of 40 to 150. The length is 2.54 cm, and the thickness is 0.15 to 0.75 mm.

  According to the present invention, a knitted fabric made of sharp multi-leaf cross-sectional filament yarns is extremely lightweight, thin and soft, has a mild and elegant luster, a smooth touch, and has excellent bursting strength characteristics. Can be provided.

  Hereinafter, the present invention will be described in detail.

  The multi-leaf cross-sectional filament yarn used in the knitted fabric of the present invention includes polyethylene terephthalate, polypropylene terephthalate, polybutadiene terephthalate, polytrimethylene terephthalate and other polyesters, nylon 6, nylon 66, nylon 12 and other polyamides, polyacrylonitrile, and any other Although it may be a synthetic polymer (polymer) fiber, it is preferably a polyamide fiber in terms of color development and strength. The polymer used for the fiber is not limited to a homopolymer but may be a copolymer thereof. In addition, known matting agents, light resistance agents, heat resistance agents, antistatic agents, and the like can be added depending on the purpose.

The multi-leaf cross-sectional filament yarn used in the knitted fabric of the present invention has a shape in which the cross section has three or more leaves having an angle α formed by the apexes of the leaves of 90 degrees or less, and preferably the number of leaves is 5 or more. Here, the leaf refers to a portion that is a convex protrusion in the cross section of the yarn, as shown in FIG. Further, the angle α is an angle B _i T _i C _i formed by the vertex T _i of the leaf and two points B _i (common to C _i −1) that each leaf shares with the adjacent leaf, and C _i (common to B _{i + 1} ). It is defined as If the angle α between the leaves is less than 90 degrees, and the number of leaves is 2 or less, the contact point with the skin does not become a point when knitting, and the skin is not smooth and gloss is too strong. Mild and elegant gloss cannot be obtained. The angle forming the apex of the leaf can be measured from a photograph of the cross section of the yarn.

The leaf radius of the multifilament cross-section filament thread is r, and two leaves B _i (common to C _i -1) that each leaf of the filament cross-section shares with the adjacent leaf, and C _i (common to B _{i + 1} ) are each leaf. The longest line segment connected by the vertices T _i is defined as a _max as shown in FIGS. At this time, the multileaf filament yarn in the present invention,
(1) 0.5r ≦ a _max
When 0.5r> a _max , since the leaf length is small, the contact with the skin is increased and a light touch is not obtained. In addition, when the leaf length is large, the reflected light into the fiber is complicated, and the depth of gloss increases, resulting in a mild and elegant gloss.

In addition, the length of a line segment B _i C _i connecting two points B _i (common to C _i-1 ) and C _i (common to B _{i + 1} ) that each leaf of the filament cross section constitutes the adjacent leaf is defined as K _i. The area of the portion where each leaf is cut out by the line segment B _i C _i is S _i , the distance between the vertex T _{i of} each leaf and the midpoint of the line segment B _i C _i is L _i , and the filament cross section has When the number of leaves is N, the multileaf filament in the present invention is
(2) Σ2S _i / K _i L _i N ≦ 1.7
It is important that Σ2S _i / K _i L _i N ≦ 1.5. When Σ2S _i / K _i L _i N = 1, the leaf becomes an accurate triangle, and when Σ2S _i / K _i L _i N> 1.7, the leaf is rounded and not sharp, so It is not possible to obtain an elegant luster with a mild touch and mild touch.

For S _i , K _i , L _i , and N, the yarn is cut perpendicularly to the fiber length direction, the cut surface is observed, taken in a photograph, and the area and length of the copied cross section are measured. Can be obtained. Specifically, the area can be measured by “DIGITAL PLANIMETER” or the like by Hiroyuki Uchida. From the measured values, S _i / K _i L _i N is calculated for i = 1 to N, respectively, and summed up to obtain Σ2S _i / K _i L _i N. For example, in the case of FIG. 2A, S ₁ , K ₁ , L ₁ , S ₂ , K ₂ , L ₂ ... S ₈ , K ₈ , L ₈ are measured and S ₁ / K ₁ L _i N , S ₂ / K ₂ L ₂ N... S ₈ / K ₈ L ₈ N is calculated and summed up to obtain Σ2S _i / K _i L _i N.

  In the present invention, it is important that the knitted fabric contains at least 30% by weight or more of multi-leaf section filament yarn, preferably 50% by weight or more, and more preferably 80% by weight or more. When the constitutional weight of the multi-leaf cross-section filament is 30% by weight or less, the characteristics of the multi-leaf cross-section yarn are not recognized, and characteristics such as lightness, light touch, mild and elegant gloss cannot be obtained.

In addition, it is important that the bursting strength of the knitted fabric of the present invention is 250 kPa or more. If the rupture strength of the knitted fabric is less than 250 kPa, it may be broken during wearing, and the rupture strength is preferably 1500 kPa or less. If it exceeds 1500 kpa, the knitted fabric becomes coarse and hard. Here, the bursting strength refers to a value measured based on A method (Murlen type method) in accordance with JIS L1018 “Knit Fabric Test Method” (1999). The knitted fabric of the present invention preferably has a basis weight of 130 g / m ² or less. If the basis weight is 130 g / m ² or less, it is generally possible to feel lightness as a knitted fabric. More preferably, it is 100 g / m ² or less. Although it varies depending on the knitted fabric, if it is a knitted fabric using 100% multi-leaf cross-sectional filament yarn, it can be 70 g / m ² or less, and a very light feeling can be obtained. Further, by setting the basis weight to 30 g / m ² or more, the process passability during dyeing, the handleability during sewing, and the sewing property become good. Here basis weight and were determined by mass per 1 m ² in accordance with JIS L1018 "knit fabric test method" (1999).

  A knitted fabric having a bursting strength in the above range and also having a gloss while maintaining the basis weight in the above range can be obtained by using the above-mentioned multileaf cross-section filament yarn. This can be achieved by using at least 30% by weight or more based on the weight. In addition, the total fineness of the multileaf filament yarn is 10 to 75 decitex, and the single fiber fineness is 0.5 to 4.0 decitex, so that it is lightweight and soft and has a soft touch and elegant luster. A knitted fabric having a high bursting strength can be obtained.

  The knitted fabric of the present invention is preferably used as a multifilament obtained by combining a plurality of multileaf filament yarns. The total fineness of the multileaf filament yarn is preferably 10 to 75 dtex and the single fiber fineness is preferably 0.5 to 4.0 dtex. More preferably, the total fineness is 10 to 56 dtex, and the single fiber fineness is 0.5 to 2.0 dtex. Unless the total fineness is 10 to 75 dtex and the single fiber fineness is 0.5 to 4.0 dtex, it is soft and thin, and the bursting strength cannot be maintained at 250 kPa.

  Moreover, the well of the knitted fabric is 40 to 85 pieces / 2.54 cm, the course is 40 to 150 pieces / 2.54 cm, and the thickness is 0.15 to 0.75 mm, so that the soft and thin And lightweight knitting can be obtained.

Further, in the present invention, it is desirable to use a core-sheath type composite yarn as described later in order to obtain a multileaf cross-sectional filament yarn, but in order to obtain a light feeling, the composite ratio of the core component to the sheath component = 30. : 70-50: 50 is desirable. In order to maintain the bursting strength of the knitted fabric of the present invention at 250 kPa or more, the composite ratio of the core component and the sheath component = 40: 60, more preferably the composite ratio of the core component and the sheath component = 50: 50, It is more preferable to thicken the part.
An example of the method for producing a multileaf filament in the present invention is as follows, for example. That is, the core-sheath composite spinning is performed with the elutable component as the sheath, the component insoluble in the eluent used when eluting the sheath component, or the component with extremely low solubility as compared with the sheath component as the multileaf portion (core component). The core component having a sharp multilobal cross-sectional shape can be left by elution treatment of the sheath component. In addition, as a polymer used for the raw material of a core component, the above-mentioned polymer (polymer) can be used, and about a sheath component eluent, it can select suitably according to a core component. Of these, a core-sheath composite yarn in which the core component is polyamide and the sheath component is polyester or polylactic acid is preferable. As the elution process, a known elution process such as an alkali elution process can be employed. These polymers, particularly the sheath component polymer, can be copolymerized or contain additives as necessary in order to accelerate the alkali elution treatment rate. In this elution process, it is important to completely elute the sheath component. If the sheath component remains, a light feeling and glossiness cannot be obtained. Moreover, in the core-sheath type composite yarn, the core component is surrounded by the sheath component, so that the surface tension prevents the leaf tip and valley of the core component from being rounded, and the core component (multi-leaf portion) Can maintain a sharp shape. From the viewpoint of preventing the core component from becoming round, it is desirable that the polymer used for the sheath component has a higher viscosity than the polymer used for the core component. In addition, the cross section of the core-sheath type composite yarn before elution of the sheath component may be any shape such as round, square, flat, Y-shaped, etc., but the round cross section is from the point of maintaining the shape of the core component. preferable. The elution process is preferably performed after knitting rather than before knitting.

  The knitted fabric of the present invention is not particularly limited to a knitted structure or the like. For example, a circular knitted fabric may be a single circular knitted fabric, a double circular knitted fabric, or a molded circular knitted fabric, and a warp knitted fabric may be a single tricot fabric, a double tricot fabric, a single raschel fabric, or a double knitted fabric. A raschel fabric can be used, and if it is a flat knitted fabric, a single flat knitted fabric, a double flat knitted fabric, or a molded flat knitted fabric can be used.

  In addition, the knitting structure includes a circular knitted fabric, a tempered reversible structure, a milling structure, an interlock structure, a reversible structure, other change structures, a half structure of a vertical knitted fabric, a back half structure, a quince coat structure, a satin structure, and a satin structure. There is no particular limitation such as a net organization, a power net organization, or other change organization. However, since 50 to 70% by weight of the sheath component is eluted after knitting, it is preferable to increase the strength more than usual in order to obtain a bursting strength of 250 kPa or more. By making the loop length and runner length during knitting 15% or more shorter than the normal knitting conditions, it is possible to increase the stitch length. When stretchability is required depending on the application, it is preferable to knit polyurethane-based elasticity. Further, depending on the use, it is also preferable to knit with a polyamide fiber that does not dissolve by elution, cotton, hemp or the like. Processing such as alkali elution treatment, scouring and dyeing in the present invention may be carried out in accordance with ordinary knitting fabric processing methods, and no special equipment is required. A flexible finishing process is preferable as an incidental process at this dyeing stage.

  In the knitted fabric of the present invention, the gap between the yarns becomes large due to high weight loss, so when a phenomenon called warai occurs in which the sharp knitted fabric and the knitted fabric stretched by the leaf tips are difficult to return, It is preferable to apply the processing with a silicon softener. As a result, the yarn and the yarn become slippery and the cracking phenomenon is eliminated. Water repellent, antifouling, antibacterial, deodorant, flame retardant, sweat-absorbing, moisture-absorbing, anti-mold, UV-absorbing, etc. It is desirable to apply appropriately according to required characteristics such as wrinkling, raising, printing, or opal processing.

  The knitted fabric of the present invention can be developed for a wide range of uses as follows. For example, it can be preferably used for athletic wear, inner wear, home wear, uniform wear, outer wear, and for supporters and socks for materials. In addition, it can be used for linings, shoe materials, gloves and the like without any problems. For athletic clothing, running shirts / pants, competition shirts / pants, golf shirts, tennis shirts, cycle shirts, outdoor shirts, polo shirts, T-shirts, baseball undershirts, training wear, sweatshirts / pants, etc. For innerwear, slips, camisole, petticoats, shorts, underpants, tights, T-shirts, round-neck shirts, U-neck shirts, body suits, girdles for general ladies, T-shirts for general gentlemen, round-neck shirts, U-neck shirts, running shirts, underpants, tights, briefs, trunks, etc. In addition, sports inners including diversion of these inners, outdoor, skiing, etc., outdoor work, indoor work, etc. Work inners. For homewear, indoor clothes, pajamas, nightgowns, gowns, etc. For outerwear, women's clothes, men's clothes, children's clothes, work clothes, etc. If it is a lining material, it can be preferably used for sportswear, women's clothing, men's clothing, children's clothing, dressing clothes, student clothing, work clothing lining, and the like. Since it is lightweight and has a soft touch and a mild and elegant luster, it is particularly preferred for dresses that are outerwear for women's clothing, slips for innerwear, camisole, petticoats, and the like.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples. In addition, each evaluation in this invention was performed with the following method.
(1) Weight per unit area Mass per 1 m ² was determined according to JIS L1018 “Testing method for knit fabric” (1999).
(2) Thickness According to JIS L1018 “Testing method for knit fabric” (1999), a thickness was measured using a thickness measuring device at a pressure of 0.7 kPa, and an average value was obtained.
(3) Burst strength Measured based on A method (Murlen type method) according to JIS L1018 “Testing method for knit fabric” (1999). That is, first, five 15 cm × 15 cm test pieces are collected. The test piece is faced up to prevent wrinkling and sagging, and the unknitted polyurethane knitted fabric is attached to a Mülen type bursting tester without applying tension. If the knitted fabric with polyurethane is knitted, it will be impossible to measure if tension is not applied because it stretches more than the rubber film of the Müren type testing machine. After drawing a 2cm diameter circle in advance on the knitted surface and fixing it to the embroidery frame When the rubber film breaks the test piece, the circle is expanded to a circle with a diameter of 3 cm and is re-fixed to the embroidery frame with tension applied, and is attached to a mullen-type burst tester. (A), and then the test piece is removed to determine the strength (B) of the rubber film alone. The burst strength (C) was calculated by the following formula, and the average value of the five sheets was shown as the burst strength.
Burst strength (C) = (A)-(B)
A: Strength at which the rubber film breaks through the test piece (kPa)
B: Strength of rubber film only at break (kPa)
(4) Evaluation of softness The softness of the knitted fabric was subjected to a comparative evaluation by tenants with respect to 10 monitors.
The average of 10 people was listed with 3 points for fairly soft items, 2 points for slightly soft items, 1 point for non-soft items, and 0 points for non-soft items.
(5) Skin touch evaluation The soft touch of the knitted fabric was subjected to a sensory comparison with 10 monitors.
The average of 10 people was listed, with 3 points being fairly dull, 2 points being slightly dull, 1 point being none, and 0 points being slimy.
(6) Glossiness evaluation The glossiness of the knitted fabric was subjected to a sensory comparison with 10 monitors.
3 points for mild and elegant gloss, 2 points for mild and elegant gloss, 1 point for non-glossy, 0 points for glare gloss, and average of 10 people did.

(7) Radius r, a _max , S _i , K _i , L _i , Σ2S _i / K _i L _i N
Various cross-section filaments were cut perpendicularly to the fiber length direction, and the cut surface was magnified and observed with a scanning microscope, photographed with a magnification of 800 times, and then further magnified 400 times with a copier. A circumscribed circle was drawn on the enlarged cross section, and the radius r was obtained. Two points B _i (common with C _i-1 ), C _i (common with B _{i + 1} ), B _i (common with C _i-1 ), C _i (B The length of the line segment B _i C _i connecting ( _{i + 1} ) is measured with K _i , and the distance between the vertex T _{i of} each leaf and the midpoint of the line segment B _i C _i is measured with L _i . The area S _i was measured by “DIGITAL PLANIMETER” by Hiroyuki Uchida. Σ2S _i / K _i L _i N is obtained by calculating 2S _i / K _i L _i for i = 1 to N from the actually measured values and summing them. For example, in the case of FIG. 2A, S ₁ , K ₁ , L ₁ , S ₂ , K ₂ , L ₂ ... S ₈ , K ₈ , L ₈ are measured and S ₁ / K ₁ L _i N , S ₂ / K ₂ L ₂ N... S ₈ / K ₈ L ₈ N is calculated and summed up to obtain Σ2S _i / K _i L _i N. When the multi-section filament was cut perpendicularly to the fiber length direction, the one deformed by cutting was omitted from the measurement.

Example 1
Using a spinneret designed such that 98% sulfuric acid relative viscosity of 2.62 nylon 6 is placed in the 8-leaf star core and polyethylene terephthalate is placed in the sheath, nylon 6 is 30% by weight. , Polyethylene terephthalate is melted and discharged at 70% by weight, spinning temperature of 290 ° C., cooled, lubricated, entangled, taken up with a non-heated roller, stretched 1.4 times with a roller heated to 160 ° C., Winding was performed at a winding speed of 4000 m / min to obtain a core-sheath composite yarn having a shape shown in FIG. 4A of 56 dtex and 18 filaments. The obtained yarn was knitted smoothly on a 42G circular knitting machine under the condition that the loop length was 180 loops with 100 loops. After refining this raw machine, the polyester component in the sheath portion was completely dissolved using sodium hydroxide 60 g / L. Subsequently, 1% by weight of acid dye (Nylosan Blue N-GFL 167% (manufactured by Client Japan Co., Ltd.)), dyeing rate at 1 ° C / min, dyeing temperature of 90 ° C, dyeing time of 30 minutes, and finishing set at 180 ° C A knitted fabric having 71 wells / 2.54 cm, 58 courses / 2.54 cm, a basis weight of 40 g / m ² , and a thickness of 0.25 mm was obtained. The bursting strength was 300 kPa. The cross-section of the multileaf filament was taken on a SEM photograph (Fig. 4 (a ')), and the angle α between the cross-section leaves and the apex was measured. Was 29 degrees. The other evaluation results are shown in Table 1.

Example 2
A yarn obtained by melt spinning under the same conditions as in Example 1 was obtained except that nylon 6 was 50% by weight and polyethylene terephthalate was 50% by weight. The obtained 56 dtex 18 filament core-sheath composite yarn having the shape shown in FIG. 4 (b) and 33 dtex polyurethane elastic yarn ("Lycra" (registered trademark), manufactured by Operontex Co., Ltd.) in a 32G tricot machine, 2 ways Tricot half was organized. The runner length was 480 loops, the nylon polyester composite yarn was 130 cm, and the lycra was 63 cm. After refining this raw machine and intermediate setting, the polyester component in the sheath portion was completely dissolved using sodium hydroxide 60 g / L. After dyeing under the same conditions as in Example 1, a finishing set is performed at 185 ° C., and a knitted fabric having 66 wells / 2.54 cm, 130 courses / 2.54 cm, a basis weight of 128.5 g / m ² , and a thickness of 0.63 mm. Obtained. The bursting strength was 280 kPa. As in Example 1, the cross-section of the multileaf filament was taken on a SEM photograph, and the angle α between the leaves of the cross-section was measured. As a result, the smallest angle was 43 degrees and the maximum was 50. It was a degree. The evaluation results are shown in Table 1.

Example 3
Except for 33 dtex and 18 filaments, a yarn having the shape shown in FIG. 4A was obtained, in which the weight ratio nylon 6 was 30% by weight and polyethylene terephthalate was 70% by weight. The resulting yarn and 17 dtex, 8 filament round nylon 6 yarns were alternately knitted on a 42G circular knitting machine under the condition that the loop length would be 170 mm with 100 loops. Dyeing was performed under conditions. The resulting knitted fabric was a knitted fabric having 83 wells / 2.54 cm, 61 courses / 2.54 cm, a basis weight of 37 g / m ² , and a thickness of 0.26 mm. The bursting strength was 290 kPa. As in Example 1, the cross-section of the multi-section filament was taken with an SEM photograph and the angle α between the leaves of the cross-section was measured. As a result, the minimum of the eight angles was 15 degrees and the maximum was 25 degrees. Met. Other results are shown in Table 1.

Comparative Example 1
A yarn obtained by melt spinning under the same conditions as in Example 1 was obtained except that nylon 6 was 20% by weight and polyethylene terephthalate was 80% by weight. The obtained 56 dtex 18 filament core-sheath composite yarn was knitted and smoothed under the same conditions as in Example 1. The obtained knitted fabric was a knitted fabric having 75 wells / 2.54 cm, 56 courses / 2.54 cm, a basis weight of 27 g / m ² , and a thickness of 0.14 mm. The bursting strength was 179 kPa. As in Example 1, the cross-section of the multileaf filament was taken on a SEM photograph, and the angle α between the leaves of the cross-section was measured. As a result, the minimum angle was 8 degrees and the maximum angle was 16 degrees. It was a degree. The other evaluation results are shown in Table 1.

Comparative Example 2
A yarn obtained by melt spinning under the same conditions as in Example 1 was obtained except that nylon 6 was 70% by weight and polyethylene terephthalate was 30% by weight. Two-way tricot halves were knitted and dyed under the same conditions as in Example 2 with the obtained 56-decitex 18-filament core-sheath composite yarn. The resulting knitted fabric was a knitted fabric having 61 wells / 2.54 cm, 134 courses / 2.54 cm, a basis weight of 182 g / m ² , and a thickness of 0.99 mm. The bursting strength was 392 kPa. As in Example 1, the cross section of the multileaf filament was taken in a SEM photograph and the angle α between the leaves of the cross section and the apex was measured. As a result, the smallest angle was 81 degrees and the largest angle was 87. It was a degree. The other evaluation results are shown in Table 1.

Comparative Example 3
Same as Example 1 30 wt% nylon 6 and 70 wt% polyethylene terephthalate melt spun 56 dtex 18 filament core-sheath composite yarn, 33 dtex nylon 6 yarn and 33 dtex polyurethane elastic yarn ("Lycra") (Registered trademark), manufactured by Operontex Co., Ltd.), a 2-way tricot half was knitted with a 32G tricot machine. The runner length was 480 loops, the nylon polyester composite yarn was 144 cm, the nylon yarn was 102 cm, and the lycra was 80 cm. After refining this raw machine and intermediate setting, the polyester component in the sheath portion was completely dissolved using sodium hydroxide 60 g / L. After dyeing under the same conditions as in Example 2, a finishing set was performed at 185 ° C. to obtain a knitted fabric having 60 wells / 2.54 cm, 125 courses / 2.54 cm, a basis weight of 190 g / m ² , and a thickness of 0.92 mm. . The bursting strength was 372 kPa. As in Example 1, the cross-section of the multileaf filament was taken on a SEM photograph and the angle α between the cross-section leaves and the apex was measured. As a result, the minimum angle was 8 degrees and the maximum angle was 29 degrees. It was a degree. The evaluation results are shown in Table 1.

It is a cross-sectional view which shows an example of the cross-sectional shape of the multileaf cross-section filament which this invention provides, (a) shows 8 leaves, (b) shows the example of 6 leaves. It is a cross-sectional view explaining the symbol which shows the cross-sectional shape of the multileaf cross-section filament defined by this invention, (a) shows 8 leaves, (b) shows the example of 6 leaves. It is a cross-sectional view explaining the symbol which shows the part of the leaf of the multileaf-section filament defined by this invention. It is the cross-sectional schematic and SEM photograph of the core-sheath composite yarn used in the Example of this invention.

Explanation of symbols

1: leaf T1 to T8: apex α of each leaf: angle r of leaf apex r: radius of circumscribed circle K1: length of B1 and C1 S1: area L of the portion where the leaf is cut by line segment B1C1 L1: leaf Distance between the vertex T1 and the midpoint of the line segment B1C1

Claims (4)

At least 30 multifilament cross-section filament yarns having a cross-sectional shape having three or more leaves having an angle α of 90 degrees or less formed by the apex of the leaves and satisfying the following expressions (1) to (2): A knitted fabric containing at least% by weight, having a bursting strength of 250 kPa or more and a basis weight of 130 g / m ² or less.
(1) 0.5r ≦ a _max
(However, the circumscribed circle radius of the filament cross-section is r, and two points B _i (common to C _i-1 ) and C _i (common to B _{i + 1} ) each leaf of the filament cross-section shares with the adjacent leaf) the longest of the line segments are connected by apexes T _i of each leaf was a _max.)
(2) Σ2S _i / K _i L _i N ≦ 1.7
(However, the length of a line segment B _i C _i connecting two points B _i (common to C _i-1 ) and C _i (common to B _{i + 1} ) that each leaf of the filament cross-section configures with the adjacent leaf is defined as K and _i, the area of a portion where each leaf is cut at the line segment _B i _{C i} and _{S i,} the distance between the midpoint of the vertices _{T i} and the line segment _B i _{C i} of each lobe and _{L i.} the filament cross The number of leaves on the face is N.) The knitted fabric according to claim 1, wherein the multileaf filament yarn is a polyamide fiber manufactured by dissolving a sheath component of a core-sheath composite yarn. 3. The knitted fabric according to claim 2, wherein a composite ratio of the core-sheath composite yarn is a weight ratio of core component: sheath component = 30: 70 to 50:50. The multifilamentary filament yarn has a total fineness of 10 to 75 dtex, a single fiber fineness of 0.5 to 4.0 dtex, and a knitted fabric well of 40 to 85 / 2.54 cm and a course of 40 to 150. The knitted fabric according to any one of claims 1 to 3, wherein the knitted fabric is 2.54 cm / 2.54 cm and has a thickness of 0.15 to 0.75 mm.