EP2628833A1

EP2628833A1 - Multilayered knitted fabric

Info

Publication number: EP2628833A1
Application number: EP11832312.0A
Authority: EP
Inventors: Junko Deguchi; Shoichi Akita
Original assignee: Asahi Kasei Fibers Corp
Current assignee: Asahi Kasei Corp
Priority date: 2010-10-12
Filing date: 2011-03-31
Publication date: 2013-08-21
Anticipated expiration: 2031-03-31
Also published as: CN103154344B; WO2012049870A1; KR20130054420A; CN103154344A; JPWO2012049870A1; US20130209743A1; KR101398699B1; JP5788895B2; EP2628833B1; TW201215721A; TWI475137B; EP2628833A4

Abstract

The knitted fabric of the present invention is knitted fabric which is not stuffy and is comfortable during insensible perspiration or slight perspiration, which even after considerable perspiration due to exercise etc. does not make the wearer feel sticky, wet, or cold because of the sweat, and which has a satisfactory texture and excellent wear resistance. The knitted fabric comprises 5-25 wt.% cellulosic filaments and 75-95 wt.% synthetic fibers, and is characterized in that in at least one surface A thereof, the proportion of the area occupied by the cellulosic filaments to the overall area of the knitted fabric in the region of the knitted fabric which ranges to a depth of 0.13 mm is 0.2-15% and that surface A to which moisture was imparted in an amount of 200 g/m² has a degree of coldness to the touch of 180-330 W/m²·C.

Description

Technical Field

The present invention relates to a multilayered knitted fabric. More specifically, the present invention relates to a multilayered knitted fabric which is highly hydroscopic, comfortable to wear, not stuffy during slight perspiration due to exercise etc., and which, even after considerable perspiration, does not make the wearer feel sticky, wet, or cold because of the sweat, and which has a satisfactory texture and appearance, as well as a textile product using said knitted fabric such as innerwear, sportswear, and bedclothes.

Background Art

Cellulosic materials such as cotton and cupra have excellent hygroscopic and water absorbing properties, and thus, when used in clothing, generally it is very comfortable during no (insensible perspiration) or slight perspiration. However, when the amount of perspiration exceeds about 100 g/m² during the summer season or during exercise, cellulosic materials, which can easily retain the absorbed sweat, tend to make the wearer feel sticky or cold after exercise. In particular, when the amount of perspiration exceeds about 200 g/m², the sticky or coldness becomes severe, making the wearer feel very uncomfortable.
As a method for preventing discomforts due to such stickiness or coldness, a variety of fabrics are being investigated that can transfer the sweat from the skin side to the front side of clothing, so as to leave no moisture on the skin side. Many of them use hydrophobic fabric at the skin side, and a variety of fabrics have been proposed including those in which different single yarn fineness and crosssectional shape of the yarn used are used at the front side and the back side of a knitted fabric.
For example, the following Patent Document 1 and Patent Document 2 propose knitted fabrics having a structure in which the front side uses a fiber having an excellent moisture absorbing ability and the back side uses a fiber having a poor moisture absorbing ability, thereby controlling the stickiness or coldness.
Patent Document 1, which uses a fiber having a poor moisture absorbing ability on the back (skin) side of a knitted fabric, has an insufficient ability of absorbing sweat. Also, since it uses a staple fiber as one having an excellent moisture absorbing ability, it has a poor ability of diffusing the absorbed sweat, and thus has an insufficient ability of reducing stickiness.
On the other hand, Patent Document 2 uses a cellulose filament as a fiber having a high moisture absorbing ability and thus has an excellent diffusing ability. However, since it uses a hydrophobic fiber on the back (skin) side of the knitted fabric, its ability of absorbing sweat is not sufficient.
Also, the following Patent Document 3 discloses a knitted fabric having unevenness provided on the back (skin) side of the knitted fabric, in which a polyester filament is arranged on the protrusion and a rayon filament fiber on the recess. However, since the protrusion which comes into contact with the skin is a hydrophobic fiber, its ability of absorbing sweat is insufficient as for the knitted fabrics described in Patent Document 1 and Patent Document 2.
Furthermore, Patent Document 4 discloses a knitted fabric having a hydrophilic fiber on the back (skin) side thereof. The Patent Document 4 discloses a knitted fabric having a dry and smooth feel, which is obtained by using a knitted fabric comprising a hydrophilic fiber and a hydrophobic fiber and making the course density of the back (skin) side of the knitted fabric greater than that of the front side, thereby imparting unevenness to the back (skin) side of the knitted fabric.
However, since the knitted fabric is highly dense and has a very high mixing ratio of a hydrophilic fiber of 25-75%, the moisture is retained at the skin side, and therefore despite the presence of unevenness, it has a considerable stickiness, and has an insufficient skin-dryness to be used in clothing.
Thus, there is still a need for providing a knitted fabric that is not stuffy and that can control stickiness and coldness, and therefore is comfortable during insensible perspiration or slight perspiration or even considerable perspiration.

Citation List

Patent Documents

Patent Document 1: Kokai (Japanese Unexamined Patent Publication) No. 2001-81652
Patent Document 2: Kokai (Japanese Unexamined Patent Publication) No. 10-25643
Patent Document 3: Kokai (Japanese Unexamined Patent Publication) No. 10-131000
Patent Document 4: Kokai (Japanese Unexamined Patent Publication) No. 2004-190151

Summary of the Invention

Problems to be Solved by the Invention

The problem to be solved by the invention is to provide a knitted fabric which is not stuffy and is comfortable during insensible perspiration or slight perspiration, which, even after considerable perspiration due to exercise etc., does not make the wearer feel sticky, wet, or cold because of the sweat, and which has a satisfactory texture and excellent wear resistance. Means to Solve the Problems
After intensive and extensive research and repeated experiments to solve the above problems, the present inventors have found that by arranging a specific amount of cellulosic filaments in the vicinity of the surface of the back (skin) side of a knitted fabric, the above problems can be solved, and thereby have completed the present invention.
The present invention is as described below.

[1] A knitted fabric at least comprising 5 to 25% by weight of cellulosic filaments and 75 to 95% by weight of synthetic fibers, wherein in at least one surface A of the knitted fabric, the proportion of the area occupied by the cellulosic filaments to the overall area of the knitted fabric in the region of the knitted fabric which ranges to a depth of 0.13 mm is 0.2 to 15% and surface A to which moisture was imparted in an amount of 200 g/m² has a degree of coldness to the touch of 180 to 330 W/m²·°C.

[2] The knitted fabric according to the above [1] which has a thickness of 0.5 to 1.2 mm.

[3] The knitted fabric according to the above [1] or [2] which has unevenness at a depth of 0.13 to 0.50 mm in the above surface A.

[4] The knitted fabric according to any one of the above [1] to [3] wherein surface B opposite to the above surface A comprises synthetic fibers.

[5] The knitted fabric according to any one of the above [1] to [3] wherein when the mixing ratio of the cellulosic filaments in the above overall knitted fabric is assumed to be X, and the proportion of the area occupied by the cellulosic filaments in the region of the knitted fabric which ranges to a depth of 0.13 mm is assumed to be Y, X>Y.

[6] The knitted fabric according to any one of the above [1] to [5] wherein the above cellulosic filaments are a composite yarn with polyester- or polyamide-based filaments.

[7] A textile product which comprises the knitted fabric according to any one of the above [1] to [6] and in which the above surface A is arranged at the skin side during wearing.

Effects of the Invention

The knitted fabric of the present invention is not stuffy and is comfortable during insensible perspiration or slight perspiration, which, even after considerable perspiration due to exercise etc., does not make the wearer feel sticky, wet, or cold because of the sweat, and has a satisfactory texture and excellent wear resistance, and thus is preferably used as a knitted fabric for innerwear, sportswear, and bedclothes.

Brief Description of Drawings

[Fig. 1] An example of the structural diagram of the knitted fabric of the present invention.
[Fig. 2] An example of the structural diagram of the knitted fabric of the present invention.
[Fig. 3] An example of the structural diagram of the knitted fabric of the present invention.
[Fig. 4] An example of the structural diagram of a conventional knitted fabric.

Mode for Carrying Out the Invention

The present invention will now be explained in detail below.
The knitted fabric of the present invention is a fabric that at least comprises 5 to 25% by weight of cellulosic filaments and 75 to 95% by weight of synthetic fibers. Thus, in the knitted fabric of the present invention, the cellulosic filaments occupy 5 to 25% by weight, preferably 5 to 20% by weight of the overall knitted fabric.
As used herein, cellulosic filaments include, but not limited to, regenerated cellulosic filaments such as rayon, cupra and acetate, natural cellulosic filaments such as silk, and the like. Compared to cellulosic staple fibers such as cotton and regenerated cellulosic staple fibers, these filaments contain less fluff and have smooth yarn surface, and thus they have a higher ability of diffusing moisture. Among them, regenerative cellulosic filaments may be preferred and, among the regenerative cellulosic filaments, rayon filaments and cupra filaments have a higher moisture content and a higher moisture-absorbing effect than the original cotton, and thus may be more preferred. Specifically in cupra filaments compared to rayon filaments, even a single fiber has smooth surface and thinner fineness, and therefore, when used in a knitted fabric, they are very soft and have a satisfactory texture, which may be specifically preferred. By arranging these fibers effectively in a knitted fabric, a knitted fabric that has an excellent hygroscopic property and excellent effect of reducing stickiness, that is not stuffy or sticky during insensible perspiration or slight to considerable perspiration, and is comfortable to wear can be made. When the proportion of cellulosic filaments to the overall knitted fabric is less than 5%, the knitted fabric has a low hygroscopic property and a poor ability of absorbing gaseous sweat during insensible perspiration or slight perspiration, the ability of absorbing and transferring moisture by cellulosic filaments becomes insufficient, the effect of reducing stickiness during perspiration cannot be expected, and thus the knitted fabric is not comfortable to wear. On the other hand, when the content of cellulosic filaments exceeds 25%, stickiness during perspiration and coldness after perspiration become greater, and thus the knitted fabric is not comfortable to wear.
The fineness of cellulosic filaments may preferably be, but not limited to, about 22 to about 84 decitex (dtex), and more preferably about 33 to about 56 dtex. While the fineness of a single yarn of cellulosic filaments may not be specifically limited, it may preferably be about 0.5 to about 2 dtex from the viewpoint of feel to the touch and texture.
When cellulosic filaments are contained in a knitted fabric, it can be interknitted with filaments or staple fibers of a polyester- or polyamide-based synthetic fiber. However, from the viewpoint of treating sweat, it may be preferred that the cellulosic filaments are arranged in the knitted fabric as a composite yarn with synthetic fibers such as a polyester- or polyamide-based synthetic fiber, specifically with a synthetic filaments. When combined, a multifilament yarn may be preferred having a fineness of the synthetic filaments of about 22 to about 84 dtex, and a fineness of a single yarn of about 0.5 to about 2 dtex, so as not to ruin softness to the touch. The ratio of fineness of the cellulosic filaments to the synthetic filaments may preferably be 1:3 to 2:1. The synthetic filaments may preferably have a modified cross-section from the viewpoint of treating sweat by diffusion during perspiration. Since a W-shaped cross-section fiber is a modified and flat shape, it satisfies both of sweat treatment by capillary action and softness, and therefore may be more preferred.
Cellulosic filaments or a composite yarn of cellulosic filaments and synthetic filaments can be arranged by being interknitted with another fiber in the knitted fabric. The partner yarn of interknitting may preferably be a synthetic filament, specifically a polyester- or polyamide-based synthetic fiber, and a multifilament yarn may be preferred having a fineness of a synthetic filament of about 16 to about 170 dtex, and a fineness of a single yarn of about 0.5 to about 2 dtex. A polyurethane fiber may be interknitted as appropriate to impart a stretching property to the knitted fabric. A multifilament yarn for use in the present invention may comprise a delustering agent such as titanium dioxide, a stabilizer such as phosphoric acid, an ultraviolet absorber such as a hydroxybenzophenone derivative, a crystal nucleating agent such as talc, a lubricant such as aerosil, an antioxidant such as a hindered phenol derivative, a flame retardant, an antistatic agent, a pigment, a fluorescent whitener, an infrared absorber, an antifoaming agent etc.
A material for use in the knitted fabric of the present invention can have crimp, and the crimp extension rate may preferably be 0 to 150% from the viewpoint of softness to the touch. The crimp extension rate of a false twisted yarn was measured under the following conditions:

The upper end of a crimped yarn is fixed, a load of 1.77 × 10^-3 cN/dt is applied on the lower end, and a length (A) after 30 seconds is measured. Then, the load of 1.77 x 10^-3 cN/dt is removed, a lowad of 0.088 cN/dt is applied, and a length (B) after 30 seconds is measured. The crimp extension rate is determined from the following formula (1): $Crimp extension rate (%) = \{(B - A) / A\} \times 100$
As described above, the knitted fabric of the present invention is a fabric that at least comprises 5 to 25% by weight of cellulosic filaments and 75 to 95% by weight of synthetic fibers. Thus, the knitted fabric of the present invention can comprise fibers other than the cellulosic filaments or the synthetic fibers. However, said synthetic fibers occupy 75 to 95% by weight, preferably 80 to 95% by weight of the overall knitted fabric.

The knitted fabric of the present invention is characterized in that in one surface A thereof, the proportion of the area occupied by the cellulosic filaments to the overall area of the knitted fabric in the region of the knitted fabric which ranges to a depth of 0.13 mm may be 0.2 to 15%, preferably 0.5 to 10%. As used herein, the region which ranges to a depth of 0.13 mm refers to the outermost layer of surface A, and this layer comes into direct contact with the sweat on the skin, and absorbs it. By generating a slantingly arranged structure in which a small amount of cellulosic filaments in this layer and more cellulosic filaments are arranged in the inner layer of the knitted fabric, the knitted fabric absorbs sweat faster than the conventional knitted fabric in which 100% of synthetic fibers is present in the skin side surface of the knitted fabric, absorbs sweat strongly into the inner layer of the knitted fabric by slantingly arranged cellulosic filaments, and furthermore sweat is widely diffused in the knitted fabric without retaining it due to the diffusing property of cellulosic filaments. Thus, the sweat on the skin can be incorporated quickly and in large quantities into the knitted fabric, permitting drastic improvement in stickiness during wearing. Also, since cellulosic filaments also have excellent moisture dispersing property, moisture dispersion tends to occur in the inner layer, and the dispersed sweat is released from the skin side to the front side where the humidity is lower.
In order to slantingly arrange cellulosic filaments from the outermost layer to the inner layer of a knitted fabric, the relation of the mixing percent X (% by weight) of cellulosic filaments in the overall knitted fabric and the proportion Y (% by area) occupied by the cellulosic filaments in the outermost layer may preferably be X>Y, more preferably (2/3) ·X>Y, and most preferably (1/2) ·X>Y. As used herein, that the proportion occupied by the cellulosic filaments on the surface of the outermost layer is smaller that the mixing percent of cellulosic filaments in the overall knitted fabric is rephrased that cellulosic filaments are slantingly arranged.
In the relationship between the proportion Yw (% by weight) occupied by the cellulosic filaments in the outermost layer and X when the specific gravity of cellulosic filaments is about 1.5, and the specific gravity of synthetic fibers is usually smaller (generally, the specific gravity of polyester-based fibers is about 1.4, that of polyurethane-based fibers is about 1.2, and that of polyamide-based fibers is about 1.1) than that was considered as well, preferably X>Yw, more preferably (2/3) ·X>Yw, and still more preferably (1/2) ·X>Yw.
At this time, Yw can be determined from the following formula (2): $Y_{W} = Y \cdot D_{1} / \{X \cdot D_{1} + (100 - X) \cdot D_{2}\}$

wherein, D₁ denotes the specific gravity of cellulosic filaments, and D₂ denotes an average specific gravity of fibers other than the cellulosic filaments.
Because, in the knitted fabric of the present invention, a small amount of cellulosic filaments are arranged in surface A which comes into direct contact with the skin of the knitted fabric of the present invention, it has excellent feel to the touch. Also, due to an excellent hygroscopic property, it can control stuffiness.
In order to further enhance the effect of reducing stickiness of the knitted fabric of the present invention, it may be preferred to create a knit structure having unevenness in surface A. The difference in height between the protrusion and the recess may preferably be about 0.13 to about 0.50 mm. Preferably, the protrusion is evenly distributed in surface A, and specifically when areas of 1 cm x 1 cm in the sample were measured, it may be preferred that any one area has 10 or more of the above protrusions, and the area of the protrusion is about 10 to 70% of the surface area. As a method for providing unevenness, there can be mentioned a method for devising a knit structure and introducing a tack structure or needle-drawing structure, a method for stacking yarns at the protrusions, a method for varying yarn fineness, and the like.
By providing unevenness on the surface of knitted fabric, degree of coldness to the touch becomes smaller, and thus when this surface was used as the skin side, stickiness during perspiration can be further alleviated. When the difference in height between the protrusion and the recess is less than about 0.13 mm, the area in contact with the skin is not different from when there is no unevenness, and thus it cannot be said that there is unevenness, and effect of the knitted fabric of further reducing stickiness cannot be expected. When the difference in height between the protrusion and the recess is about 0.13 mm or more, the contact area of the skin and the knitted fabric becomes smaller when the fabric is worn with the side having unevenness as the skin side, and thus the effect of reducing stickiness becomes greater when the knitted fabric absorbed moisture. On the other hand, when the difference in height between the protrusion and the recess exceeds about 0.50 mm, the thickness of the fabric becomes great, and thereby rough feel due to unevenness becomes greater leading to poor wearing feel such as stuffiness due to retention of the air layer.
Also, if the difference in height between the protrusion and the recess exceeds 0.13 mm, there will be regions which are not included in the region ranging to a depth of 0.13 mm from the surface. Thus, in this case, surface A can be divided into a region (hereinafter referred to as the outermost layer of surface A) which ranges to a depth of 0.13 mm and a region (hereinafter referred to as the inner layer of surface A) which exceeds a depth of 0.13 mm. The area occupied by the protrusions of the knitted fabric in the outermost layer of surface A may preferably be 10 to 70% of the total area of surface A.
The difference in height between the protrusion and the recess can be determined by photographing the cross section of a knitted fabric with an electron microscope, followed by measuring at 5 different sites and averaging. The difference between the protrusion and the recess of about 0.17 to 0.45 mm may be more preferred.
By arranging surface A of the knitted fabric of the present invention at the skin side of the wearer of the textile product, the above-mentioned effect exhibited by the knitted fabric of the present invention can preferably be expressed.
The knitted fabric of the present invention is characterized in that the degree of coldness to the touch of surface A when a 200 g/m² moisture was imparted is about 180 to about 330 W/m²·°C. Said degree of coldness to the touch (hereinafter referred to as the value of coldness to the touch) may preferably be about 180 to 280 W/m²·°C, more preferably about 180 to about 260 W/m²·°C, and more preferably about 180 to about 240 W/m²·°C.
In measuring this degree of coldness to the touch, Thermo Labo II manufactured by Kato Tech Co., Ltd. is used. This instrument measures the amount of heat transfer when a warmed hot plate is placed on a sample. A specific measuring procedure is as follows:
After adjusting the humidity of a sample to be used in measurement for 24 hours in an environment of 20°C and 65% RH (relative humidity), sampling is carried out at 8 cm × 8cm. A maximum amount of heat transfer is measured at the instant when a hot plate warmed to 30°C in an environment of 20°C and 65% RH is placed onto a sample of the knitted fabric placed with surface A facing upward.
The moisture when a moisture of 200 g/m² was imparted is a condition that simulates the amount of moisture in the sweat absorbed by fabric after an exercise that induces considerable sweating.
In a method of imparting moisture during measurement, a sprayer may be used to impart moisture to the surface A side of the sample to a weight of the sample sampled at 8 cm × 8cm of +1.28 g. The temperature of water in the sprayer at this time is 20°C.
When there is residual water in the knitted fabric, a large amount of heat is taken from the hot plate, because the thermal conductivity of water is high, and the degree of coldness to the touch becomes large. Thus, a sample having a large degree of coldness to the touch means a high stickiness. When the degree of coldness to the touch exceeds about 330 W/m²·°C, the stickiness becomes unfavorably large, whereas at a degree of coldness to the touch smaller than about 180 W/m²·°C, the stickiness is favorably small, but to attain a degree of coldness to the touch of less than about 180 W/M²·°C, unevenness must be markedly large, which is not preferred from the viewpoint of texture to the touch. While a conventional knitted fabric comprising cellulose that generally has a large degree of coldness to the touch far exceeding about 330 W/m²·°C, cellulosic filaments are slantingly arranged in the knitted fabric of the present invention so as to utilize the water-absorbing and diffusing ability of the cellulosic filaments, thereby providing a knitted fabric having an improved stickiness even when a large amount of water was imparted.
The thickness of the knitted fabric of the present invention may preferably be about 0.5 to about 1.2 mm.
The thickness of a knitted fabric is measured using a thickness measuring gauge manufactured by Peacock, in which a measuring part of φ3.0 cm was allowed to come into contact with a knitted fabric with a 5 g load, and thickness is measured at 3 sites and averaged. When this thickness is smaller than about 0.5 mm, it has a poor ability of treating sweat and is not comfortable, whereas when the thickness exceeds about 1.2 mm, roughness of the fabric becomes large and spoils texture. The thickness of the knitted fabric of the present invention may more preferably be about 0.5 to about 1.0 mm. According to the present invention, the sweat on the skin is absorbed quickly by the water-absorbing and diffusing properties of cellulosic filaments, and thus even a knitted fabric thinner than those intended to reduce stickiness by the difference of density or fineness between the front and back of a 100% polyester can exhibit a comparative effect.
In the knitted fabric of the present invention, surface B opposite to surface A may be composed mainly of synthetic fibers. Because, when cellulosic filaments are arranged on the surface of a knitted fabric, broken thread may easily occur due to abrasion on the front surface side of a textile product during wearing, and interknitting or difference in color and luster from a composite fiber may easily occur, which can ruin the appearance. The area occupied by the cellulosic filaments in surface B to the entire area of the knitted fabric may preferably be 5% or less, more preferably 1% or less, and still more preferably 0.2% or less, and may preferably be smaller than the proportion of the area occupied by the cellulosic filaments in the region up to a depth of 0.13 mm in surface A. Most preferably, surface B may be composed only of synthetic fibers.
The knitted fabric of the present invention may be warp knitted or weft knitted, and may preferably have a layered structure of 3 layers or more, having 2 layers of the front and back layers and an inner layer in between them. Due to restraint of knitted fabric structure, boundaries between layers may be ambiguous or may be so as long as it is a knitted fabric that functions equally to 3 layers.
As a knitting machine for making the knitted fabric of the present invention, there can be used a flat knitting machine, a double knit circular knitting machine, a tricot knitting machine, a Raschel knitting machine and the like, and in order to make a multilayered knitted fabric having 3 layers or more, a double knit circular knitting machine may be preferred. The knitting gauge used of a knitting machine may preferably be about 10 to about 40 GG.
As knitting structure, in the case of double knit circular knitting, for making the knitted fabric of the present invention, herringbone, blister, waffle, dimple mesh etc. can be used, and a structure that uses, but not limited to, tuck knitting in which unevenness can be obtained on the back side of a knitted fabric may be preferred. In warp knitting, by arranging cellulosic filaments in the middle in three-reed knitting to produce a structure that expresses unevenness, the desired effect can be exhibited. The number of loops in the course direction on the front and back of a knitted fabric of the present invention may not be specifically limited as long as it does not cause any problems in construction.
In order to exhibit the effect of reducing stickiness of the knitted fabric of the present invention, a slantingly arranged structure is effective in which a small amount of cellulosic filaments are arranged in the outermost layer of surface A of the 3-layered structure, cellulosic filaments at an amount larger than that in the outermost layer are arranged in the inner layer of surface A, and synthetic fibers are arranged in surface B. In this case, for example, by controlling the amount supplied of an interlinked partner yarn and cellulosic filaments by varying the number of yarn feeding ports and yarn fineness, cellulosic filaments can be slanted. Also, by using plating knitting of cellulosic filaments or a composite yarn thereof and synthetic fibers in surface A of a 2-layer structured knitted fabric, and arranging cellulosic filaments mainly in the inner layer of surface A of the knitted fabric, there may preferably be used a method that satisfies the construction of the present invention, if not a 3-layered structure. There can also be used a method in which, by using cellulosic filaments or a composite yarn thereof and synthetic fibers in surface A and varying the yarn fineness to thicken the yarn of synthetic fibers, the cellulosic filaments can be relatively arranged inside. In this case, the fineness of synthetic fibers in surface A may preferably be 1.5-times as that of the cellulosic filaments or a composite yarn thereof.
The weight of the knitted fabric of the present invention may preferably be, but not limited to, about 50 to about 300 g/m², more preferably about 80 to about 250 g/m².
The knitted fabric of the present invention may preferably be subjected to a moisture absorption process.
By making the knitting density of surface B greater than that of surface A of the knitted fabric of the present invention, a capillary phenomenon can be exhibited to transfer moisture from the surface A side to the surface B side. By wearing such a surface A of the knitted fabric of the present invention having a moisture-transferring function as the skin side of clothing, moisture tends not to remain on the skin surface even during considerable perspiration, and can alleviate stickiness and coldness during wearing. Such a knitted fabric can be produced using a different-gauge knitting machine that has different gauges at the dial side and the cylinder side.
In order to exhibit a capillary phenomenon, the number of loops in the well direction of knitted fabric surface B may preferably be made about 1.1 to about 4.5-fold the number of loops in the well direction of knitted fabric surface A. The number of loops in the wale direction on the surface may be determined by measuring the number of knitted loops per width of 2.54 cm (1 inch) with a densimeter, linen tester, or the like. The number of loops as used herein refers to the number of knitted stitches identified on each of the front and back of a knitted fabric, and does not include knitted stitches such as tuck loop or sinker loop.
In another method for exhibiting a capillary phenomenon, the yarn fineness of the single yarn on the surface B side is made smaller than that of the single yarn on the surface A side. Preferably the yarn fineness of the single yarn on the surface B side is made 1/2 or less that of the single yarn on the surface A side.
The knitted fabric of the present invention can be used in textile products to be worn by humans. At this time, by using surface B of the knitted fabric of the present invention at the outer air side and surface A at the skin side, the above-mentioned effect can be exhibited.
The knitted fabric of the present invention may be suitable for, but not limited to, applications in clothing materials among textile products, for example clothing for which a sweat treating function is desired such as sportswear and innerwear, can also be applied in clothing materials for outer wear and lining, bedclothing such as sheets, and furthermore sanitary articles such as incontinence pants, has comfort due to the moisture-absorbing property, and exhibits the effect of reducing stickiness and coldness due to moisture.

Examples

The present invention will now be explained more specifically below with reference to examples. The present invention is not limited to them in any way. The knitted fabric obtained in examples was evaluated in the following manner.

(1) Area occupied by the cellulosic filaments in surface A.
- (i) A knitted fabric sample is immersed in a dye solution containing 1% owf of a direct dye of an intermediate deep color (such as Sumilight Blue) and 5 g/l of Na₂SO₄ and heated at 90°C for 30 minutes to stain the cellulosic filament part of the fabric. The density of the stained sample is adjusted to be equal to that before staining.
- (ii) In the sample from the above (i), 3 areas in a range of 1 cm long × 1 cm wide are randomly specified, and marked with thread etc. so as to permit three dimensional identification.
- (iii) The marked areas in surface A of the sample are measured at a measuring interval of 20 µm using a three dimensional surface profile measuring machine. After correcting the tilt of the data, the maximum value of height is changed to 20 µm in Excel's contour map, and the height in which distribution is ubiquitously exhibited in a 1 cm × 1 cm sample is set as the height of the outermost side, from which a two-dimensional map is created with a value smaller by 0.13 mm as the maximum value of the contour map to specify the outermost layer part (a region that ranges to a depth of 0.13 mm) in surface A. As used herein "the height in which distribution is ubiquitously exhibited" refers to a height in which, when a 1 cm × 1 cm region was divided into four regions of 5 mm × 5 mm, the surface appears in any of the divided regions. The cellulosic filaments in the surface of the outermost layer is measured in the following manner.

(iv) The marked areas in surface A of the same sample are photographed with a microscope, the data of the above (iii) and (iv) are superimposed, and the area wherein the colored yarns appear on the surface of the outermost layer in surface A is calculated as an area occupied by the cellulosic filaments. When the processing of image (iv) is difficult, the data in the above (iii) and (iv) are printed out in the same size, and after measuring the weight of paper of a 1 cm × 1 cm area, the two are superimposed, the outermost layer part is excised, from which the stained yarn part is further excised and the weight is measured for calculation. The area occupied by the cellulosic filaments in surface A of the knitted fabric can be calculated in the following equation: $A proportion (area %) occupied by the cellulosic filaments in surface A of the knitted fabric = the area$
$occupied by the cellulosic filaments in the surface of the outermost layer part / the area of the sample$

(2) The mixing ratio of cellulosic filaments (% by weight)

The mixing ratio X of the overall knitted fabric represents an interknitting ratio of cellulosic filaments of the knitted fabric, and can be calculated from the weight consumed of the yarn in constructing the knitted fabric, or the weight of cellulosic filaments measured by decomposing the knitted fabric obtained based on the following equation (4): $X (% by weight) = (weight of cellulosic filaments in the knitted fabric / weight of the knitted fabric) \times 100$

When the calculation based on the amount of yarn used is difficult, it can be calculated based on the moisture content of the knitted fabric.

(3) Wearing test

After a person wearing a shirt prepared so that the back side of the stained knitted fabric becomes the skin side was placed at rest for 10 minutes in an artificial climate chamber at an environment of 28°C and 65% RH, the wearer was subjected to a running exercise for 30 minutes at 8 km/h on a treadmill ORK-3000 manufactured by Ohtake Root Kogyo Ltd., and then placed at rest for 10 minutes again. Feel to the touch/texture, comfortable feeling before the running exercise, and stickiness and coldness after the running exercise were each subjected to sensory rating based on the following criteria:

A: Good feel to the touch and good texture
B: Slightly bad feel to the touch and slightly bad texture
C: Bad feel to the touch and bad texture

A: Comfortable
B: Slightly uncomfortable
C: Uncomfortable

A: Feel no stickiness
B: Feel slight stickiness
C: Feel stickiness

A: Feel no coldness
B: Feel slight coldness
C: Feel coldness

[Working Example 1]

Using a dual different-gauge circular knitting machine with 18 GG on the dial side and 24 GG on the cylinder side, a composite yarn (crimp extension rate 7.4%) prepared by combining a polyester circular cross-sectional yarn of 84dtex/72f, a cupra circular cross-sectional yarn of 33dtex/24f, and a polyester circular cross-sectional yarn of 56dtex/72f followed by false twisting, and a yarn (total fineness 336 dtex) prepared by knitting 4 polyester circular cross-sectional yarns of 84dtex/72f together were fed as shown in the knitting structure of Fig. 1 (circled numerals in the figure indicate the order of knitting) to obtain a knitted gray fabric. After this gray fabric was scoured at 80°C × 20 minutes and washed in a jet dyeing machine, it was preset at 180 × 90 seconds at a tentering rate of 20% using a pin tenter. Thereafter, it was subjected to polyester staining, a water absorption process and water-washing, and then extended to a degree in which wrinkles are removed, and final set was carried out at 150 × 90 seconds to obtain a knitted fabric with a weight of 150 g/m² and a thickness of 0.97 mm. At the surface A side of the knitted fabric obtained, protrusions were present due to difference in fineness of arranged yarns, but the region (the outermost part) ranging to a depth of 0.13 mm occupied 55% of the area of the overall knitted fabric. The ratio of area occupied by the cellulosic filaments at the outermost layer of surface A was 2.5% of the area of the overall knitted fabric, and the cellulosic filaments were slantingly arranged. The ratio of area occupied by the cellulosic filaments at the outermost layer of surface B was 0%. The degree of coldness of surface A when 200 g/m² of water was imparted was 195 W/m²·°C. In the wearing test of a shirt obtained from this knitted fabric, it was comfortable to wear before exercise, and even after perspiration, there was no stickiness or coldness. The result is shown in Table 1.

[Working Example 2]

Using a 28-gauge dual gauge circular knitting machine, a composite yarn prepared by combining a polyester circular cross-sectional yarn of 56dtex/72f, a cupra circular cross-sectional yarn of 33dtex/24f, and a polyester circular cross-sectional yarn of 56dtex/72f followed by false twisting, and a polyester circular cross-sectional yarns of 56dtex/24f were fed as shown in the knitting structure of Fig. 2 (circled numerals in the figure indicate the order of knitting, and the same yarn type is fed at the knitting portion indicated on the same line (for example, circled numerals 1 and 13)). When the composite yarn and a polyester circular cross-sectional yarn of 56dtex/72f were fed, they were subjected to plating so that the composite yarn is arranged inside of the knitted fabric, and by processing similarly to Working Example 1, a knitted fabric with a weight of 134 g/m² and a thickness of 0.69 mm was obtained. At the surface A side of the knitted fabric obtained, protrusions were present due to yarn overlapping, and the ratio of area occupied by the cellulosic filaments at the outermost layer of surface A was 4.7%, and the cellulosic filaments were slantingly arranged. The ratio of area occupied by the cellulosic filaments at surface B was 0%. The degree of coldness of surface A when 200 g/m² of water was imparted was 220 W/m²·°C. In the wearing test of a shirt obtained from this knitted fabric, it was comfortable to wear before exercise, and even after perspiration, there was no stickiness or coldness. The result is shown in Table 1.

[Working Example 3]

Using a 28 GG tricot knitting machine, a polyester circular cross-sectional yarn of 56dtex/24f as a structure 10/23 at the front, a polyester circular cross-sectional yarn of 56dtex/24f and a cupra circular cross-sectional yarn of 56dtex/30f with each single yarn alternately arranged as structure 21/10 at the middle, and a polyester W cross-sectional yarn of 56dtex/30f as a structure 10/12 at the back were arranged. The cupra circular cross-sectional yarn was arranged mainly in the intermediate layer of the knitted fabric. In a processing treatment similar to Working Example 1, a knitted fabric with a weight of 138 g/m² and a thickness of 0.61 mm was obtained. At the surface A side of the knitted fabric obtained, unevenness was present in the knitting structure, and the ratio of area occupied by the cellulosic filaments at the outermost layer of surface A was 9.3%, and the cellulosic filaments were slantingly arranged. The ratio of area occupied by the cellulosic filaments at surface B was 0%. The degree of coldness of surface A when 200 g/m² of water was imparted was 255 W/m²·°C. In the wearing test of a shirt obtained from this knitted fabric, it was comfortable to wear and there was no stickiness or coldness. The result is shown in Table 1.

[Working Example 4]

Using a 26-gauge dual circular knitting machine, a composite yarn prepared by interlace-combining a polyester circular cross-sectional yarn of 84dtex/72f, a cupra circular cross-sectional yarn of 33dtex/24f, and a polyester circular cross-sectional yarn of 56dtex/72f followed by false twisting, and a polyester circular cross-sectional yarns of 56dtex/24f were fed as shown in the knitting structure of Fig. 3 (circled numerals in the figure indicate the order of knitting, and the same yarn type is fed at the knitting portion indicated on the same line (for example, circled numerals 1, 5 and 9)). When the composite yarn and a polyester circular cross-sectional yarn of 56dtex/24 were fed, they were subjected to plating so that the composite yarn is arranged inside of the knitted fabric, and by processing similarly to Working Example 1, a knitted fabric with a weight of 148 g/m² and a thickness of 0.68 mm was obtained. At the surface A side of the knitted fabric obtained, unevenness was small, and the ratio of area occupied by the cellulosic filaments at surface A was 4.2%, and the cellulosic filaments were slantingly arranged. The ratio of area occupied by the cellulosic filaments at surface B was 0%. The degree of coldness at surface A when 200 g/m² of water was imparted was 229 W/m²·°C. In the wearing test of a shirt obtained from this knitted fabric, it was comfortable to wear before exercise, and even after perspiration, there was no stickiness or coldness. The result is shown in Table 1.

[Working Example 5]

Except that the cupra circular cross-sectional yarn of 33dtex/24f in Working Example 2 was replaced with a rayon 84dtex/30f, a knitted fabric similar to that in Working Example 2 was prepared and a knitted fabric with a weight of 147 g/m² and a thickness of 0.78 mm was obtained. At the surface A side of the knitted fabric obtained, protrusions were present due to yarn overlapping, and the ratio of area occupied by the cellulosic filaments at the outermost layer of surface A was 9.8%, and the cellulosic filaments were slantingly arranged. The ratio of area occupied by the cellulosic filaments in surface B was 5%. The degree of coldness in surface A when 200 g/m² of water was imparted was 273 W/m²·°C. In the wearing test of a shirt obtained from this knitted fabric, it was comfortable to wear, and there was little stickiness or coldness. The result is shown in Table 1.

[Working Example 6]

Except that the composite yarn in Working Example 2 was replaced with a cupra circular cross-sectional yarn of 56dtex/30f and the yarn was fed as shown in the knitting structure of Fig. 2, conditions similar to that in Working Example 2 were used to obtain a knitted fabric with a weight of 127 g/m² and a thickness of 0.68 mm. At the surface A side of the knitted fabric obtained, protrusions were present due to yarn overlapping, and the ratio of area occupied by the cellulosic filaments at the outermost layer of surface A was 13.8%. The ratio of area occupied by the cellulosic filaments at surface B was 3%. The degree of coldness in surface A when 200 g/m² of water was imparted was 294 W/m²·°C. In the wearing test of a shirt obtained from this knitted fabric, there was little stickiness or coldness. The result is shown in Table 1.

[Comparative Example 1]

Using a 28 GG dual circular knitting machine, a composite yarn prepared by interlace-combining a cupra circular cross-sectional yarn of 56dtex/24f and a polyester circular cross-sectional yarn of 56dtex/72f followed by false twisting, and a polyester circular cross-sectional yarn of 84dtex/72f with each single yarn alternately arranged were knitted as shown in the knitting structure of Fig. 4. By processing similarly to Working Example 1, a knitted fabric with a weight of 139 g/m² and a thickness of 0.71 mm was obtained. At the surface A side of the knitted fabric obtained, unevenness was small, and the ratio of area occupied by the cellulosic filaments at surface A was as large as 18.8%, and the cellulosic filaments were not slantingly arranged. The ratio of area occupied by the cellulosic filaments at surface B was 18%. The degree of coldness at surface A when 200 g/m² of water was imparted was 355 W/m²·°C. In the wearing test of a shirt obtained from this knitted fabric, there was considerable stickiness and coldness. The result is shown in Table 1.

[Comparative Example 2]

Except that all yarns were a polyester circular cross-sectional yarn of 84dtex/72f, processing similarly to Working Example 1 was carried out to obtain a knitted fabric with a weight of 126 g/m² and a thickness of 0.66 mm. The knitted fabric was 100% polyester, and the degree of coldness when 200 g/m² of water was imparted was 348 W/m²·°C. In the wearing test of a shirt obtained from this knitted fabric, it lacked comfort both before and after exercise. The result is shown in Table 1.
[Table 1]

Industrial Applicability

By using the knitted fabric of the present invention, there can be produced a textile product such as clothing that is not stuffy and is comfortable during insensible perspiration, and can alleviate stickiness or coldness during slight perspiration or even considerable perspiration due to exercise for long hours etc. Textile products thus produced such as sportswear, inner, and outer, and bedclothing etc. are comfortable to wear.

Claims

A knitted fabric at least comprising 5 to 25% by weight of cellulosic filaments and 75 to 95% by weight of synthetic fibers, wherein in at least one surface A of the knitted fabric, the proportion of the area occupied by the cellulosic filaments to the overall area of the knitted fabric in the region of the knitted fabric which ranges to a depth of 0.13 mm is 0.2 to 15% and surface A to which moisture was imparted in an amount of 200 g/m² has a degree of coldness to the touch of 180 to 330 W/m²·°C.
The knitted fabric according to claim 1 which has a thickness of 0.5 to 1.2 mm.
The knitted fabric according to claim 2 which has unevenness at a depth of 0.13 to 0.50 mm in said surface A.
The knitted fabric according to any one of claims 1 to 3 wherein surface B opposite to said surface A comprises synthetic fibers.
The knitted fabric according to any one of claims 1 to 3 wherein when the mixing ratio of the cellulosic filaments in said overall knitted fabric is assumed to be X, and the proportion of the area occupied by the cellulosic filaments in the region of the knitted fabric which ranges to a depth of 0.13 mm is assumed to be Y, X>Y.
The knitted fabric according to any one of claim 1 to 3 wherein said cellulosic filaments are a composite yarn with polyester- or polyamide-based filaments.
A textile product which comprises the knitted fabric according to any one of claims 1 to 3 and in which the abovesaid surface A is arranged at the skin side during wearing.