JP7193912B2 - Absorbent knitted fabric - Google Patents

Description

TECHNICAL FIELD The present invention relates to a water-absorbing knitted fabric having excellent water-absorbing properties and good texture.

BACKGROUND ART Conventionally, there has been a demand for knitted fabrics having water absorption and good texture in fields such as uniform clothing and sports clothing, and many water-absorbing knitted fabrics have been proposed so far. In recent years, from the viewpoint of imparting high added value to knitted fabrics, it is desired to impart high water absorption performance at a lower cost, but the fact is that such demands cannot be met simply by water-absorbing knitted fabrics. is.

In order to impart high water absorbency to a woven or knitted fabric, first, the shape of the yarn used in the woven or knitted fabric should be devised, and second, the structure of the woven or knitted fabric, which is the base material, should be devised so that the water absorbency can be more easily expressed. and thirdly, devising the composition or concentration of the water-absorbing agent to be used. Among them, devising the thread form is an effective technique that has been conventionally practiced.

Patent Documents 1 to 3 propose woven or knitted fabrics using modified cross-section yarns. By using these techniques, it is possible to impart water absorbency to the woven or knitted fabric.

Patent document 4 describes a mixed yarn composed of at least two types of fiber groups with different dyeing properties, and at least one of the fiber groups has a multi-lobed cross-sectional shape with three or more recesses in the cross-sectional shape. and a polyester mixed yarn having an irregularity of 1.7 to 6.0. , and lightness, as well as water absorbency.

Japanese Patent No. 3869107 Japanese Patent No. 5003643 JP 2016-44377 A Japanese Patent Application Laid-Open No. 2001-200439

The use of modified cross-section yarns such as those described in Patent Documents 1 to 4 is effective in that water absorbency can be imparted uniformly regardless of the design of the knitted fabric, but is sufficiently satisfactory in terms of water absorbency. However, further improvement is desired. In addition, the surface of a knitted fabric using the modified cross-section yarn has a rough touch, and there is also the drawback that it is not possible to express a luxurious texture.

Under these circumstances, there is a demand for a technique that imparts excellent water absorption even when using an inexpensive water-absorbing agent and imparts a luxurious and unique texture to the surface of the knitted fabric. No technique has been proposed so far.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a knitted fabric that has excellent water absorbency even with the use of an inexpensive water absorbing agent, and that exhibits a luxurious and unique texture on the surface of the knitted fabric.

The inventors of the present invention consider that the conventional technique of providing a fine uneven structure on the surface of a woven or knitted fabric is realized by devising the design of the woven or knitted fabric, such as the texture, density, and basis weight of the woven or knitted fabric. I thought that such a device would not lead to a fundamental solution for further improving the water absorption and the luxurious texture. In other words, the inventors focused on obtaining high water absorbency and high-quality feel by devising the structure of the yarn itself constituting the knitted fabric and the physical properties of the knitted fabric.

From this point of view, the present inventors have made intensive studies on the structure of the yarn of the constituent fibers of the knitted fabric and the physical properties of the knitted fabric. A knitted fabric containing a mixed entangled yarn (heat-shrinkable mixed entangled yarn) that shrinks by hot water treatment and subjected to hot water shrinkage treatment has excellent water absorption just by using a water absorbing agent. and a unique texture with a sense of luxury can be provided. Specifically, in the threads of the constituent fibers of the knitted fabric, protrusions made of polyester fibers with a small fineness are stably formed, and the water absorption action due to the capillary action of the protrusions and the water absorption action of the water absorbing agent are combined to increase the water absorption. found to rise. Furthermore, since the protrusions formed on the yarns of the constituent fibers of the knitted fabric are formed by gently intertwining polyester fibers with a small fineness, the surface of the knitted fabric has a soft and smooth touch due to the brushed feeling. The part where the fine fibers are intertwined forms a layer (air retention layer) that can retain a lot of air on the surface of the yarn, and the air retention layer provides a good feeling of swelling or resilience on the surface of the knitted fabric. It was discovered that it imparts texture.

More specifically, it includes a mixed entangled yarn having the following characteristics (i) to (iv), a water absorbing agent is attached to the surface, and an elongation rate measured according to JIS L 1096:2010 (constant load method , load 14.7 N) is 120% or less, it has been found that a water-absorbent knitted fabric can have both excellent water absorbency and good texture.
(i) Polyester fiber A having a single filament fineness of 0.2 to 0.9 dtex and a total fineness of 30 to 100 dtex, and polyester fiber B having a single filament fineness of 1.0 to 5.0 dtex and a total fineness of 30 to 100 dtex. Consists of
(ii) The single filament fineness ratio (A/B) between the polyester fiber A and the polyester fiber B is in the range of 1/20 to 1/4.
(iii) The mass ratio (A/B) of the polyester fiber A and the polyester fiber B is in the range of 20/80 to 80/20.
(iv) Protrusions made of polyester fiber A are formed on the surface portion.

The present invention is an invention completed by further studies based on these findings. That is, the present invention provides inventions in the following aspects.
Section 1. A water-absorbing knitted fabric containing a mixed entangled yarn and having a water-absorbing agent attached to the surface,
The mixed entangled yarn consists of a polyester fiber A having a single yarn fineness of 0.2 to 0.9 dtex and a total fineness of 30 to 100 dtex, and a single yarn fineness of 1.0 to 5.0 dtex and a total fineness of 30 to 100 dtex. It is composed of polyester fiber B of
The single yarn fineness ratio (A/B) between the polyester fiber A and the polyester fiber B is 1/20 to 1/4,
The mass ratio (A/B) of the polyester fiber A and the polyester fiber B is 20/80 to 80/20,
A protruding portion is formed by the polyester fiber A on the surface portion of the mixed entangled yarn,
Item 2. A water-absorbent knitted fabric having an elongation rate (constant load method, load 14.7 N) of 120% or less measured according to JIS L 1096:2010. Item 2. The absorbent knitted fabric according to Item 1, wherein the average deviation (SMD) of the surface roughness of the woven or knitted fabric measured by the KES-F system is 1.5 to 6.5 μm.
Item 3. Item 3. The water-absorbing quick-drying woven or knitted fabric according to Item 1 or 2, which has a water absorption height of 101 mm or more as measured according to the Byrek method described in JIS L 1907:2010.
Section 4. Item 4. The absorbent knitted fabric according to any one of items 1 to 3, wherein the number of entanglements of the mixed entangled yarn is 90 to 300/m.
Item 5. 5. The absorbent knitted fabric according to any one of Items 1 to 4, wherein the knitting density is 55 to 150 courses/2.54 cm and 45 to 100 wales/2.54 cm.
Item 6. A method for producing the absorbent knitted fabric according to any one of Items 1 to 5,
A step of preparing a heat-shrinkable mixed entangled yarn having an elongation of 18 to 50%;
a step of knitting the heat-shrinkable mixed entangled yarn to produce a gray fabric;
a step of subjecting the gray fabric to a hot water shrinkage treatment to obtain a low-stretch woven or knitted fabric;
a step of water-absorbing the low-stretch knitted fabric to obtain the water-absorbent knitted fabric of the present invention;
A method for producing a water-absorbing knitted fabric, comprising:
Item 7. The step of preparing the heat-shrinkable mixed entangled yarn comprises:
(1) A polyester highly oriented undrawn yarn B having a single filament fineness of 1.0 to 10.0 dtex, a total fineness of 30 to 200 dtex, an elongation of 80 to 150%, and a boiling water shrinkage of 20% or more is drawn at a draw ratio of 1.0. A drawing step of drawing at 3 to 1.7 times to obtain a polyester drawn yarn B, or
A step of preparing a polyester drawn yarn B having a single yarn fineness of 0.6 to 4.8 dtex, a total fineness of 18 to 96 dtex, an elongation of 15 to 60%, and a boiling water shrinkage of 20% or more;
(2) Polyester highly oriented undrawn yarn A with a single yarn fineness of 0.20 to 1.44 dtex, a total fineness of 30 to 160 dtex, and an elongation of 80 to 150% is processed at a processing speed of 100 to 700 m / min and a draw ratio of 1. A false twisting step of false twisting under conditions of 1 to 1.6 times to obtain a polyester false twisted yarn A;
(3) The polyester false twisted yarn A and the drawn polyester yarn B are subjected to an air pressure of 0.1 to 1.0 Mpa using a fluid nozzle, and the difference in overfeed rate between the drawn polyester yarn B and the polyester false twisted yarn A is 0 to 10. a mixed fiber entanglement step of mixing and entangling under the condition of 0%;
Item 7. The method for producing a water absorbent knitted fabric according to Item 6.

In the knitted fabric of the present invention, a protruding portion in which thin fibers protrude is formed on the surface portion of the mixed entangled yarn, which is the constituent fiber. Excellent water absorbency is realized by the combination of the water absorbency caused by the capillary action of the protrusions of the fine fibers and the water absorbency of the water absorbing agent. Therefore, according to the present invention, it is possible to provide a knitted fabric having excellent water absorbency without any special modification to the structure of the knitted fabric and using a normal water-absorbing agent.

In addition, in the knitted fabric of the present invention, the protrusions of the thin fibers formed in the mixed entangled yarn, which are the constituent fibers, provide a soft and smooth touch due to the brushed feeling, and the air formed by the entanglement of the fine fibers. The holding layer expresses a feeling of resilience and a feeling of swelling. Therefore, according to the present invention, it is possible to provide a knitted fabric having not only excellent water absorbency but also a high quality and unique texture.

1 is an optical microscope photograph of a mixed entangled yarn contained in a water-absorbent knitted fabric (Example 1) of the present invention. 1 is an optical microscope photograph of a thick portion of a water-absorbent knitted fabric (Example 1) of the present invention. FIG. 2 is a schematic diagram for explaining an example of a heat-shrinkable mixed entangled yarn preparation step in the method for producing a water-absorbent knitted fabric of the present invention.

The water-absorbent knitted fabric of the present invention contains a mixed entangled yarn having a specific configuration, has a water-absorbing agent attached to the surface, and has an elongation rate measured according to JIS L 1096:2010 (constant load method, load 14. 7N) is 120% or less. The present invention will be described in detail below.

[Mixed entangled yarn]
The mixed fiber entangled yarn used in the present invention includes polyester fiber A having a single yarn fineness of 0.2 to 0.9 dtex and a total fineness of 30 to 100 dtex, and a single yarn fineness of 1.0 to 5.0 dtex, and Polyester fiber B having a total fineness of 30 to 100 dtex. In this mixed fiber entangled yarn, the mass ratio (A/B) of the polyester fiber A and the polyester fiber B is in the range of 20/80 to 80/20, and the surface portion of the mixed fiber entangled yarn is A projecting portion (convex portion) is formed.

By setting the monofilament fineness of the polyester fiber A and the polyester fiber B within the specific ranges described above, both can be sufficiently entwined. As a result of this entanglement, fine projections are formed by the relatively fine polyester fibers A on the surface of the mixed entangled yarn (see FIG. 1). Therefore, when water droplets are placed on the projecting portion, the water droplets tend to migrate to the inside of the mixed entangled yarn due to capillary action. The water-absorbing action of the protrusions due to the capillary action and the water-absorbing action of the water-absorbing agent described below are combined to provide the water-absorbing knitted fabric of the present invention with excellent water-absorbing properties. In the present invention, the protruding portion of the polyester fiber A refers to a portion of the surface portion of the mixed entangled yarn in which the polyester fiber A protrudes outward due to loops, slacks, or the like of the polyester fiber A.

In addition, as will be described later, since this mixed fiber entangled yarn is obtained by mixing two types of polyester fibers A and B having a specific single filament fineness at a specific mass ratio, relatively thin polyester fibers are formed on the surface portion. A part is formed in which A is loosely intertwined. The portion where the fine fibers are entangled forms a layer (air retention layer) that easily retains air. The protruding portion protrudes from this portion where the polyester fibers A are intertwined. By forming the protrusions and the air retention layer in the mixed intertwined yarn in this manner, the water-absorbing knitted fabric of the present invention can have a luxurious and unique texture such as a swelling feeling and a resilience feeling. Become. In the mixed fiber entangled yarn, the polyester fibers A and B are entangled further inside the air retaining layer.

Furthermore, by setting the total fineness of the polyester fiber A and the polyester fiber B within the specific ranges described above, it is possible to obtain a water-absorbing knitted fabric having excellent water-absorbing properties and feel. Here, simply reducing the fineness of the constituent fibers reduces the volume and makes it difficult to maintain the projections of the polyester fibers A, resulting in poor water absorption and poor texture. However, in the water-absorbing knitted fabric of the present invention, polyester fibers B having high hot water shrinkability are used as the material fibers, and mixed fiber entangled yarns subjected to heat shrink treatment are included. Therefore, the polyester fiber B is sufficiently heat-shrunk, making it easier to remarkably maintain the protruding portion formed by protruding the polyester fiber A, and even when fine fineness polyester fibers are used (in particular, Even when the fineness of the polyester fiber A is sufficiently reduced, the projections are maintained. Furthermore, in the water-absorbing knitted fabric of the present invention, the polyester fiber B is sufficiently heat-shrunk, so that the stretchability is suppressed, and the stretchability is weak and difficult to stretch, so that it does not become too soft and has a good texture. be able to.

From the viewpoint of making a mixed entangled yarn that can impart high water absorbency to knitted fabrics, the single yarn fineness of the polyester fiber A is preferably about 0.2 to 0.8 dtex, more preferably 0.2 to 0.6 dtex. about 0.2 to 0.5 dtex, more preferably about 0.2 to 0.5 dtex. If the single filament fineness of the polyester fiber A is less than 0.2 dtex, the fiber is too fine to have a poor opening effect, and the effect of entangling with the polyester fiber B is reduced, and entanglement defects are likely to occur. On the other hand, if the single filament fineness of the polyester fiber A exceeds 0.9 dtex, the fiber becomes rigid and the mixed fiber with the polyester fiber B becomes insufficient, resulting in poor entangling. Further, when the polyester fibers A are thick, the fibers become rigid, making it difficult to form the above-mentioned air retention layer, and as a result, it becomes difficult to impart desired water absorbency and texture.

The polyester fiber A has a total fineness of 30 to 100 dtex, preferably 30 to 85 dtex, more preferably 30 to 80 dtex. When it is 30 dtex or more, the entanglement with the polyester fiber B becomes sufficient, the entangled state becomes good, and the projecting portion and the air retaining layer are easily maintained. When it is 100 dtex or less, it is excellent in lightness.

When the single filament fineness of the polyester fiber B is less than 1.0 dtex, it becomes difficult to retain the fine protrusions formed by the polyester fiber A on the surface portion of the mixed entangled yarn, and the air retention as described above becomes difficult. It becomes difficult to form layers. In addition, when the single yarn fineness of the polyester fiber A and the polyester fiber B are approximately the same, the water-absorbent knitted fabric of the present invention having mixed entangled yarns becomes too soft, and the knitted fabric tends to have no stiffness. On the other hand, if the single filament fineness of the polyester fiber B exceeds 5.0 dtex, even when mixed with the polyester fiber A having a single filament fineness in the above range, the knitted fabric as a whole will have a hard feel. Such a woven or knitted fabric is not preferable as a woven or knitted fabric for clothing. Furthermore, when the single filament fineness of the polyester fiber B exceeds 5.0 dtex, the entangled state becomes poor, making it difficult to form the fine projections on the surface of the knitted fabric, and the desired water absorption of the knitted fabric. It becomes difficult to impart properties and texture. From the viewpoint of effectively providing excellent texture while providing excellent water absorption, the single yarn fineness of the polyester fiber B is preferably about 1.5 to 4.0 dtex, more preferably 2.0 to 4.0 dtex. About 3.8 dtex is mentioned.

The polyester fiber B has a total fineness of 30 to 100 dtex, preferably 32 to 90 dtex, more preferably 40 to 90 dtex, and even more preferably 40 to 85 dtex. When it is 30 dtex or more, it becomes easier to form and maintain the protrusions and the air retention layer. When it is 100 dtex or less, it is excellent in lightness.

The single yarn fineness ratio (A/B) between polyester fiber A and polyester fiber B may be set to 1/20 to 1/4, preferably 1/20 to 1/5, and 1/15. It is more preferably to 1/6, more preferably 1/10 to 1/6. In the water-absorbing knitted fabric of the present invention, even if the fineness of the polyester fiber A is sufficiently small in order to make it lighter, the above-mentioned polyester fiber B facilitates the formation and maintenance of the projections, resulting in excellent water absorption. properties and texture can be imparted.

In the present invention, the degree of false twist crimp (that is, the crimp ratio) in the mixed entangled yarn is preferably low, for example, 10% or less is more preferable, and 0% is particularly preferable. The mixed fiber entangled yarn can form or maintain the protrusions as described above on the surface portion due to the heat shrinkage of the polyester fiber B, and because it heat shrinks in the longitudinal direction, the crimp rate as the mixed fiber entangled yarn is This is because they do not actually have them. If the crimp rate of the mixed entangled yarn exceeds 10%, the heat shrink treatment may be insufficient, and it may become difficult to obtain the desired water absorbency and feel.

In the present invention, the crimp ratio of the mixed entangled yarn is a value obtained by measuring by the following method. First, using a measuring machine with a frame circumference of 1.125 m, the knot is removed from the mixed entangled yarn by winding it five times, and then the kasse is hung on a stand in a free state at room temperature for a whole day and night. Next, while applying a load of 0.000147 cN/dtex to the skein, it is placed in boiling water and subjected to wet heat treatment for 30 minutes. After that, the skein is taken out, the water is lightly removed with a filter paper, and the skein is left at room temperature in a free state for 30 minutes. Then, a load of 0.000147 cN/dtex and 0.00177 cN/dtex (light heavy load) are applied to the skein, and the length X is measured. Subsequently, while the load of 0.000147 cN/dtex is applied, a load of 0.044 cN/dtex (heavy load) is applied instead of the light heavy load, and the length Y is measured. After that, it is calculated based on the formula of crimp rate (%)=(Y−X)/Y×100. The crimp rate is measured for five mixed entangled yarns, and the average of each is taken as the crimp rate of the yarn.

The mass ratio (A/B) of polyester fiber A and polyester fiber B is in the range of 20/80 to 80/20. When the mass ratio (mixing ratio) of the polyester fiber A is less than 20%, the proportion of the polyester fiber A in the mixed entangled yarn is too small, so it is difficult to form the protrusions as described above on the surface portion of the mixed entangled yarn. It becomes difficult to impart high water absorbency to the woven or knitted fabric. On the other hand, if the mixed ratio of the polyester fiber A exceeds 80%, the ratio of the polyester fiber B is too small, and it becomes difficult to retain the protrusions on the surface portion. For this reason, the fine protrusions are easily crushed, making it difficult to impart excellent water absorbency and texture to the knitted fabric. The mass ratio (A/B) between polyester fiber A and polyester fiber B is preferably about 30/70 to 70/30.

The mixed fiber entangled yarn is mixed and entangled as a whole yarn. is more preferred. If the entanglement number is less than 90 pieces/m, the entanglement state is likely to be unraveled, and it may be difficult to form the fine protrusions as described above on the surface portion of the mixed entangled yarn. In addition, if the entangled state is easily unraveled, guide wear that is inevitably received in the manufacturing process of the woven or knitted fabric may cause misalignment inside the yarn, which may easily induce defects in the knitted fabric. On the other hand, if the entanglement number exceeds 300/m, the polyester fiber A and the polyester fiber B are excessively entangled, making it difficult to form the above protrusions, making it difficult to impart excellent water absorbency and texture to the knitted fabric. . In the present invention, the number of entanglements of the mixed entangled yarn is a value obtained by measuring based on the JIS L1013 8.15 hook method.

In addition, in the mixed fiber entangled yarn used in the present invention, at least one of the polyester fiber A and the polyester fiber B may contain an appropriate additive to provide a secondary function to the water absorbent knitted fabric of the present invention. can also be given. Note that the function imparted by the additive usually increases as the amount (absolute amount) of the additive used increases. It is preferable to polyester fiber A because the amount of additive used can be increased. Such additives include, for example, solar blocking substances, infrared absorbing substances, and the like. These additives may be used singly or in combination of two or more.

When the mixed entangled yarn used in the present invention contains a sun-blocking substance, the water-absorbent knitted fabric can be provided with a cool feeling due to the sunlight-blocking effect. When the mixed fiber entangled yarn contains a sunscreen substance, it is preferable that the polyester fiber B contains the sunscreen substance from the above-mentioned viewpoint. The sunscreen material used in the present invention may be any material that does not transmit visible or infrared rays of sunlight and that is dispersible in the polyester. From the viewpoint of imparting a good cool feeling to the water-absorbing knitted fabric by providing excellent sun-shielding properties, preferred examples of the sun-shielding substance include titanium oxide, potassium titanate, zinc oxide, and indium oxide. be done. These sunscreen substances may be used singly or in combination of two or more.

When the polyester fiber A and/or the polyester fiber B contains the sunscreen substance, the content is not particularly limited, but is, for example, approximately 3 to 10% by mass, preferably approximately 3 to 7% by mass. By satisfying such a content, it is possible to impart a desired refreshing feeling while suppressing deterioration of spinnability. Further, the polyester fiber A or the polyester fiber B may have a concentric core-sheath fiber cross section, and the amount of the solar blocking substance contained in the core and the sheath may be different. For example, the amount of the sunscreen substance contained in the sheath should be 0.8% by mass or less, and the total fiber should contain about 3 to 10% by mass of the sunscreen substance. By reducing the content of the sheath, the guide is less likely to be worn during the manufacturing process, and yarn breakage and fluff are less likely to occur.

Further, when the mixed fiber entangled yarn used in the present invention contains an infrared absorbing substance, heat retention can be imparted to the water-absorbent knitted fabric. When the mixed fiber entangled yarn contains an infrared absorbing substance, it is preferable that the polyester fibers B contain the infrared absorbing substance from the above-mentioned viewpoint. The UV-absorbing substance used in the present invention may be any substance that can absorb infrared rays and convert them into heat and that can be dispersed in the polyester. From the viewpoint of imparting excellent heat retention to the water-absorbing knitted fabric by providing excellent infrared absorption, suitable examples of the infrared absorbing material include zirconium carbide, silicon carbide, antimony-doped indium oxide, and the like. These infrared absorbing substances may be used singly or in combination of two or more.

When the polyester fiber A and/or the polyester fiber B contains an infrared absorbing substance, the content is not particularly limited, but is, for example, about 0.5 to 5% by mass. By satisfying such a content, desired heat retention can be imparted while suppressing deterioration of spinnability. Further, the polyester fiber A or polyester fiber B may have a concentric core-sheath type fiber cross section, and a difference may be provided in the amount of the infrared absorbing substance contained in the core portion and the sheath portion. For example, the amount of the infrared absorbing material contained in the core is about 5 to 25% by mass, more preferably about 7 to 17% by mass, and the entire fiber contains about 0.5 to 5% by mass of the infrared absorbing material. It is better to By reducing the content of the sheath, the guide is less likely to be worn during the manufacturing process, and yarn breakage and fluff are less likely to occur.

In addition, cationic dyeable polyester may be used as the polyester fiber A and/or the polyester fiber B in order to impart design properties to the water-absorbent knitted fabric of the present invention. When a cationic dyeable polyester is used, it is possible to impart a heathered feeling by dyeing with a cationic dye during the dyeing process.

The cationic dyeable polyester is not particularly limited as long as it is dyed with a cationic dye. Polyesters that have been copolymerized to some extent are preferred.

[Water absorbing agent]
In the absorbent knitted fabric of the present invention, a water absorbing agent is attached to at least one surface of the woven or knitted fabric. In the water-absorbent knitted fabric of the present invention, when the moisture-permeable waterproof layer described later is laminated, it is sufficient that the water-absorbing agent is attached to the surface opposite to the surface on which the moisture-proof waterproof layer is provided. When the waterproof layer is not laminated, the water-absorbing agent may be attached to one or both surfaces of the knitted fabric.

A water-absorbing agent is an additive that imparts hydrophilicity to fibers and improves affinity with water, and is sometimes called a water-absorbing agent, a water-absorbing agent, or the like. As the water absorbing agent, any hydrophilic substance can be used as long as it adheres to textile products and can impart affinity for water, and those commonly used in the textile field can be used. As described above, in the water-absorbent knitted fabric of the present invention, the surface structure of the mixed entangled yarns constituting the knitted fabric is made specific, thereby improving the water absorbency and the texture. Even if it is used, it can have excellent water absorbency. Therefore, the type of water-absorbing agent used in the present invention is not particularly limited. , polyethylene oxide-based compounds such as polyethylene oxide-added silicon-based compounds; and dialkyl sulfosuccinates such as sodium dioleyl sulfosuccinate. These water absorbing agents may be used singly or in combination of two or more. Among these water-absorbing agents, polyethylene oxide-based compounds are preferred, and polyethylene oxide-added polyester-based compounds are more preferred.

The amount of the water-absorbing agent attached to the water-absorbing knitted fabric of the present invention may be appropriately set according to the type of water-absorbing agent to be used, the intended degree of water absorption, and the like. For example, if the amount of the water-absorbing agent attached to the knitted fabric is increased, the ability to absorb sweat will increase when the knitted fabric is used in, for example, sportswear. The solid content of the water absorbing agent in the water absorbent knitted fabric of the present invention is, for example, 0.0001 to 5 g/m ² , preferably 0.01 to 0.5 g/m ² .

In addition, in the water-absorbing knitted fabric of the present invention, by increasing the adhesion of the water-absorbing agent, it is possible to maintain good water-absorbing and quick-drying properties even after repeated washing, and even if it is worn repeatedly in actual use. , you can get comfortable wearing feeling. In order to increase the adhesion of the water absorbing agent, for example, a cross-linking agent may be used to bind the water absorbing agent to the knitted fabric, or a water absorbing agent having a reactive group that binds to the polyester fiber may be used.

[Structure and characteristics of water-absorbing knitted fabric]
In the absorbent knitted fabric of the present invention, it is sufficient that the mixed entangled yarn is used as at least a part of the constituent yarns. The amount used is 20% by mass or more, preferably 25% by mass or more, more preferably 35% by mass or more, still more preferably 50% by mass or more, still more preferably 70% by mass or more, particularly preferably 80% by mass or more, 90 % or more, 95 mass % or more, or 100 mass %.

The water-absorbent knitted fabric of the present invention has an elongation rate (constant load method, load 14.7 N) measured according to JIS L 1096:2010 of 120% or less. The elongation rate is preferably 30 to 100%, more preferably 40 to 90%. When the elongation rate (elasticity) is within the above range, the polyester fibers B contained in the mixed entangled yarn are sufficiently thermally shrunk, which is an indicator that the knitted fabric has a good feel. Furthermore, when the elongation rate (stretchability) is within the above range, the polyester fibers B in the mixed entangled yarn are sufficiently shrunk in hot water, and the fine protrusions caused by the polyester fibers A as described above are sufficiently removed. Since it is formed and maintained, it serves as an indicator that the water absorbency of the knitted fabric is enhanced. The lower limit of stretchability is preferably about 30% so that the texture does not become too stiff. In the water-absorbent knitted fabric of the present invention, the use amount of the mixed entangled yarn in the knitted fabric may be set to 20% by mass or more in order to set the elongation rate within the above range.

In the water-absorbing knitted fabric of the present invention, the mean deviation (SMD) of the surface roughness of the woven or knitted fabric by the KES-F system can be used as an index of the fineness of the protrusions formed on the surface portion of the mixed entangled yarn. . In the absorbent knitted fabric of the present invention, the mean deviation (SMD) of the fabric surface roughness by the KES-F system is preferably 1.5 to 5.0 μm. When the average deviation (SMD) is less than 1.5 μm, the projections are too fine and rather flat. As a result, the texture may be poor in swelling feeling and repulsion feeling. On the other hand, when the average deviation (SMD) exceeds 6.5 μm, the projections become too large, and the texture may be rough and poor. In order to set the average deviation (SMD) within the above range, the amount of the mixed entangled yarn used in the water absorbent knitted fabric of the present invention may be adjusted. It may be set to 20% by mass or more.

In addition, in the water-absorbing knitted fabric of the present invention, even if polyester fibers A and polyester fibers B having a fine fineness are used in order to improve lightness, mixed fibers are entangled because the polyester fibers B are shrunk in hot water. Thread protrusions can be easily formed and maintained, and an SMD of 1.5 or greater can be achieved.

In the present invention, the mean deviation (SMD) of the surface roughness of a woven or knitted fabric measured by the KES-F system is a value obtained under the following measurement conditions using an automated surface tester.
(1) A water-absorbing knitted fabric to be measured is cut into a 20 cm square test piece, and a tension of 400 g is applied to the test piece, and the test piece is placed in an automated surface tester.
(2) A vertical load of 50 g including the metal friction element is applied to the test piece, and the test piece is moved back and forth 30 mm with the contact pressure of the spring contacting the friction element with a force of 10 g. Measure the variation in surface roughness of the piece.
(3) The measurement is performed three times each in two directions of WARP and WEFT, and the average value is defined as the mean deviation (SMD).

The water-absorbing knitted fabric of the present invention has excellent water-absorbing properties, and such water-absorbing properties can be evaluated using the water-absorbing height in the Byrek method described in JIS L 1907:2010 as an index. The water absorbency of the water-absorbing knitted fabric of the present invention includes, for example, a water absorption height of 101 mm or more, preferably 120 mm or more, and more preferably 150 mm or more according to the Byrek method described in JIS L 1907:2010.

In addition, from the viewpoint of further improving water absorption in the present invention, the cover factor (CF) of the knitted fabric is preferably 1500 to 3000, more preferably 2200 to 2800. If the cover factor is less than 1,500, the knitted fabric will have rough texture points and will have more voids in the knitted fabric. As a result, water droplets tend to fall into the voids, and the capillarity may not be properly developed. On the other hand, when the cover factor exceeds 3000, the restraint by the structure points is strengthened, and the fine projections on the surface of the mixed entangled yarn tend to be lost, and the improvement of water absorbency cannot be expected. , the soft and smooth texture may be lost.

Note that the cover factor (CF) is a numerical representation of the coarseness and density of a knitted fabric, and in the case of a woven fabric, it is calculated by the following formula.

In the water absorbent knitted fabric of the present invention, the knitting density is not particularly limited, but is, for example, 55 to 150 courses/2.54 cm and 45 to 100 wales/2.54 cm, preferably 50 to 100 courses/2.54 cm and 45 ~85 wales/2.54 cm. If the course density and the wale density are below the respective ranges, the knitted fabric will have rough texture points, and there will be a tendency for voids to increase in the knitted fabric. As a result, water droplets tend to fall into the voids, and the capillarity may not be properly developed. On the other hand, when the course density and wale density are exceeded, the restraint by the tissue points is strengthened, and the tear strength and burst strength of the knitted fabric may be lowered.

The water-absorbent knitted fabric of the present invention is excellent in light weight by using fibers having a fine fineness as constituent fibers. Although the basis weight of the water-absorbing knitted fabric of the present invention is not particularly limited, it is, for example, preferably 200 g/m ² or less, more preferably 150 g/m ² or less. The lower limit of the basis weight is not particularly limited, but is, for example, 80 g/m ² .

Further, the knitting structure of the water-absorbent knitted fabric of the present invention is not limited, and a structure may be appropriately adopted according to the application. Specific examples of the knitting structure of the water-absorbing knitted fabric of the present invention include circular knitting such as plain knitting, smooth knitting, rubber knitting, and pearl knitting; warp knitting such as half knitting and satin knitting; It can be an organization. In the water-absorbent knitted fabric of the present invention, the knitted fabric in which the fine protrusions of the mixed entangled yarn are retained as they are can further improve the water absorbency and the texture. It is preferably arranged in a woven weave. From the same point of view, among the knitting structures described above, a structure with a smooth surface (for example, circular knitting is smooth, tuck mesh, etc., warp knitting is half, satin, etc.) is preferable.

FIG. 2 is a photograph of the thick portion of the water-absorbing knitted fabric of the present invention obtained in Example 1, taken with an optical microscope (magnification: 100 times). As is clear from FIG. 1, it can be understood that the polyester fiber B is thermally shrunk, so that the knitted fabric itself is pushed in, and the protrusion of the polyester fiber A is maintained. As a result, even when the fineness of the constituent fibers is reduced to improve the lightness, especially when the fineness of the polyester fiber A is made thinner than that of the polyester fiber B, the projecting portion is sufficiently formed. It maintains a non-flat knitted surface and can have excellent water absorption.

The water-absorbent knitted fabric of the present invention may be made into a laminated fabric by laminating a moisture-permeable waterproof layer on one side. By providing the moisture-permeable and waterproof layer in this manner, both moisture permeability and waterproofness can be achieved. In the water-absorbing knitted fabric of the present invention, when the water-absorbing agent is attached only to one surface, the water-permeable moisture-proof layer may be provided on the side to which the water-absorbing agent is not attached.

The resin that constitutes the moisture-permeable and waterproof layer is not particularly limited, but examples thereof include those composed of a polyurethane resin as a main component. Further, an adhesive layer may be included between the absorbent knitted fabric and the moisture-permeable waterproof layer. Further, another fiber fabric may be laminated on the moisture-permeable and waterproof layer.

[Other processing]
If necessary, the water-absorbing knitted fabric of the present invention may be subjected to antibacterial finishing, dyeing finishing, water-repellent back water-absorbing finishing, UV-cut finishing, heat storage finishing, antibacterial finishing, antibacterial and deodorizing finishing, deodorizing finishing, antifouling finishing, antibacterial finishing, Post-processing such as mosquito processing, calendering, and printing may be applied. In any processing, it is preferable to perform such processing under conditions that the projections are not crushed to the extent that the effects of the present invention are lost.

[Use of water-absorbing knitted fabric]
The water-absorbing knitted fabric of the present invention is excellent in water-absorbing property and light weight, and has a good texture. Therefore, it is suitably used in applications such as uniform clothing, sports clothing, clothing products such as casual wear, and outdoor products.

[Method for producing water-absorbing knitted fabric]
The method for producing a water-absorbent knitted fabric of the present invention includes a step of preparing a heat-shrinkable mixed fiber entangled yarn having an elongation of 18 to 50% (heat-shrinkable mixed fiber entangled yarn preparation step), and a heat-shrinkable mixed fiber entangled yarn. A process of knitting yarn to produce a gray fabric (grey fabric manufacturing process), a process of subjecting the gray fabric to hot water shrinkage to obtain a low-stretch woven or knitted fabric (hot water shrinkage treatment process), and a water absorption treatment of the low-stretch fabric. and a step of obtaining the water-absorbing knitted fabric of the present invention (water-absorbing processing step) in this order.

Further, when laminating a moisture-permeable waterproof layer on the water-absorbent knitted fabric of the present invention, a step of laminating a moisture-permeable waterproof layer on one side of the water-absorbent knitted fabric after the water-absorbing process (moisture-permeable waterproof layer lamination step). include.

Hereinafter, each step of the method for producing a water-absorbent knitted fabric of the present invention will be specifically described.

(Preparation step for heat-shrinkable mixed fiber entangled yarn)
In the heat-shrinkable mixed-fiber entangled yarn preparation step, a heat-shrinkable mixed-fiber entangled yarn having an elongation of 18 to 50% may be prepared. The elongation of the heat-shrinkable mixed entangled yarn to be prepared is preferably 18 to 45%, more preferably 18 to 40%. The elongation of the heat-shrinkable mixed entangled yarn was measured using a constant-speed elongation-type tensile tester in accordance with JIS L1013 8.5.1 under the conditions of a sample length of 200 mm and a tensile speed of 200 mm/min. It is a value obtained by doing. The same applies to the method for measuring the elongation of highly oriented polyester undrawn yarn A and highly oriented polyester undrawn yarn B, which will be described later.

Specific embodiments of the heat-shrinkable mixed entangled yarn preparation step are not particularly limited, but include, for example, the following steps.
(1) A polyester highly oriented undrawn yarn B having a single filament fineness of 1.0 to 10.0 dtex, a total fineness of 30 to 200 dtex, a boiling water shrinkage of 20% or more, and an elongation of 80 to 150% is drawn at a draw ratio of 1.0. Drawing step of drawing at 3 to 1.7 times to obtain polyester drawn yarn B, or single yarn fineness of 0.6 to 4.8 dtex, total fineness of 18 to 96 dtex, elongation of 15 to 60%, boiling water shrinkage A step of preparing a polyester drawn yarn B having a ratio of 20% or more;
(2) Polyester highly oriented undrawn yarn A with a single yarn fineness of 0.2 to 1.44 dtex, a total fineness of 30 to 160 dtex, and an elongation of 80 to 150% is processed at a processing speed of 100 to 700 m / min and a draw ratio of 1. A false twisting step of false twisting under conditions of 1 to 1.6 times to obtain a polyester false twisted yarn A.
(3) The polyester drawn yarn B drawn in the drawing process and the polyester false twisted yarn A false twisted in the false twisting process are subjected to an air pressure of 0.1 to 1.0 Mpa using a fluid nozzle. and the polyester false twisted yarn A are mixed and entangled under the condition that the difference in overfeed rate is 0 to 10.0%.

The heat-shrinkable mixed-fiber entangled yarn prepared in the heat-shrinkable mixed-fiber entangled yarn preparation step passes through the gray fabric production step, the hot water shrinkage treatment step, and the water-absorbent treatment step, and is included in the water-absorbent knitted fabric of the present invention. It can be an entangled yarn. In the heat-shrinkable mixed fiber entangled yarn preparation step, a specific polyester highly oriented undrawn yarn B (to become the polyester fiber B constituting the mixed fiber entangled yarn) is drawn in advance at a specific draw ratio, and the polyester drawn yarn B A stretching step is performed. As a result, the elongation of the polyester highly oriented undrawn yarn A (which becomes the polyester fiber A constituting the mixed entangled yarn) and the drawn polyester yarn B are almost the same, or the drawn polyester yarn B is slightly lower. Next, the polyester highly oriented undrawn yarn A is false-twisted in advance to obtain a polyester false-twisted yarn A, which is a false-twisting step. As a result, the polyester highly oriented undrawn yarn A is opened and easily entangled with the drawn polyester yarn B. After that, a mixed fiber entangling step is performed to combine the drawn polyester yarn B drawn in the drawing step and the false twisted polyester yarn A, which is the other party of the mixed fiber, to obtain a heat-shrinkable mixed fiber entangled yarn. In the heat-shrinkable mixed entangled yarn, it is preferable that the polyester false-twisted yarn A is arranged more on the outer side (surface side) by adjusting the overfeed rate of both.

In the water-absorbent knitted fabric of the present invention obtained through the greige production process, the hot water shrinkage treatment process, and the water absorption process, the polyester highly oriented undrawn yarn A constitutes the mixed fiber entangled yarn. As a result, the polyester highly oriented undrawn yarn B becomes the above polyester fiber B constituting the mixed fiber entangled yarn.

A polyester highly oriented undrawn yarn refers to a multifilament yarn obtained by spinning and winding a polyester polymer at a speed of about 2000 to 4000 m/min. As the polyester polymer, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and the like can be used singly or in combination. The polyester polymer may also be a copolyester. Copolymerization components include aromatic dicarboxylic acids such as isophthalic acid, 5-alkaline isophthalic acid and 3,3′-diphenyldicarboxylic acid; aliphatic dicarboxylic acids such as adipic acid, sebacic acid and succinic acid; diethylene glycol, 1,4 -aliphatic or alicyclic diols such as butanediol and 1,4-cyclohexanediol; copolymerization components such as p-hydroxybenzoic acid. The polyester polymer may optionally contain modifiers such as matting agents, stabilizers, flame retardants, colorants and the like. The polyester highly oriented undrawn yarn is configured by bundling a plurality of highly oriented undrawn fibers. For example, when the fiber cross section is a concentric core-sheath type, it is arranged in each of the core and the sheath. In consideration of polymer compatibility, it is preferred that both polyester polymers are the same.

The polyester highly oriented undrawn yarn A may have a single yarn fineness of 0.2 to 1.44 dtex, a total fineness of 30 to 160 dtex, and an elongation of 80 to 150%, but the single yarn fineness is 0.2 to 0. It is preferable that the single yarn fineness is 0.22-0.9 dtex, the total fineness is 30-100 dtex, and the elongation is 85-130%. More preferably, the single yarn fineness is 0.22 to 0.85 dtex, and the total fineness is particularly preferably 33 to 100 dtex. If the single yarn fineness of the polyester highly oriented undrawn yarn A is less than 0.2 dtex, the single yarn is too thin and the opening effect is poor, making it difficult to sufficiently mix with the polyester highly oriented undrawn yarn B described later. , entanglement defects tend to occur. As a result, in the water-absorbent knitted fabric of the present invention, it becomes difficult to form protrusions on the surface portion of the mixed entangled yarn, and yarn breakage and fluff are likely to occur, which is not preferable. On the other hand, if the single yarn fineness of the polyester highly oriented undrawn yarn A exceeds 1.44 dtex, large voids are likely to be formed in the yarn, making it difficult to sufficiently mix with the polyester highly oriented undrawn yarn B, resulting in poor entanglement. easily occur. As a result, it becomes difficult to form a protrusion.

Further, the boiling water shrinkage of the polyester highly oriented undrawn yarn A is preferably in a range lower than that of the polyester highly oriented undrawn yarn B, for example, 15 to 35%, preferably 15 to 30%, more preferably 15%. % or more and less than 20%. Here, the boiling water shrinkage rate of the polyester highly oriented undrawn yarn A is immersed in hot water at 100 ° C. for 30 minutes in the "skein dimensional change rate (A method)" specified in JIS L1013 8.18.1. It is the skein dimensional change rate measured under the condition of The same applies to the method for measuring the boiling water shrinkage of the polyester highly oriented undrawn yarn B, which will be described later.

When the total fineness of the polyester highly oriented undrawn yarn A is 30 dtex or more, the entanglement with the polyester highly oriented undrawn yarn B is improved, and the projecting portion and the air retention layer are easily maintained. On the other hand, when it is 160 dtex or less, a water-absorbent knitted fabric having excellent lightness can be obtained.

If the elongation of the polyester highly oriented undrawn yarn A is less than 80%, yarn breakage may occur frequently in the false twisting step described below. On the other hand, even if an attempt is made to obtain a highly oriented undrawn yarn having an elongation of more than 150%, yarn breakage, quality deterioration, and the like occur during production, making stable supply difficult.

The polyester highly oriented undrawn yarn B may have a single filament fineness of 1.0 to 10.0 dtex, a total fineness of 30 to 200 dtex, a boiling water shrinkage of 20% or more, and an elongation of 80 to 150%. Preferably, the yarn fineness is 1.0-5.0 dtex, the total fineness is 30-100 dtex, the boiling water shrinkage is 20-50%, the elongation is 85-150%, and the single yarn fineness is 1.5-5. More preferably, the fiber has a total fineness of 0 dtex, a total fineness of 30 to 90 dtex, a boiling water shrinkage of 20 to 40%, and an elongation of 90 to 150%. When the single filament fineness of the polyester highly oriented undrawn yarn B is less than 1.0 dtex, the projecting portion made of the polyester fiber A can be firmly held after becoming the mixed filament entangled yarn contained in the water absorbent knitted fabric. However, the protrusion is easily crushed. In addition, the thread as a whole becomes too thin, and the texture of the woven or knitted fabric becomes poor in elasticity. In addition, if the single yarn fineness exceeds 10.0 dtex, the entangled state is deteriorated. Furthermore, the texture of the water-absorbing knitted fabric deteriorates, which is not preferable.

Further, when the total fineness of the polyester highly oriented undrawn yarn B is 30 dtex or more, it becomes easy to maintain the protruding portion and the air retaining layer. On the other hand, when it is 200 dtex or less, a knitted fabric having excellent lightness can be obtained.

Further, when the boiling water shrinkage ratio of the polyester highly oriented undrawn yarn B is 20% or more, the stretchability and SMD can be set to the ranges as described above by going through the hot water shrinkage treatment step described later, and the water absorption A knitted fabric having excellent properties can be obtained. Furthermore, it is preferable because a water-absorbent knitted fabric with good texture can be obtained. Here, the boiling water shrinkage rate of the polyester highly oriented undrawn yarn B is immersed in hot water at 100 ° C. for 30 minutes in the "skein dimensional change rate (A method)" specified in JIS L1013 8.18.1. It is the skein dimensional change rate measured under the condition of

Further, if the elongation of the polyester highly oriented undrawn yarn B is less than 80%, yarn breakage may occur frequently in the later-described drawing step. On the other hand, if the elongation exceeds 150%, the elongation of the mixed entangled yarn becomes too high, which is not preferable from the viewpoint of stable quality.

Next, the heat-shrinkable mixed entangled yarn preparation step will be described in detail with reference to the schematic diagram of FIG. First, the packages YA and YB of the polyester highly oriented undrawn yarns A and B are set on creels, respectively. Next, the polyester highly oriented undrawn yarn B is introduced to the first supply roller 1 . Then, a drawing step is performed in which the polyester highly oriented undrawn yarn B is drawn while being heated by the heater 2 between the first supply roller 1 and the first take-up roller 3 .

In the stretching step, the stretching ratio may be set to 1.3 to 1.7 times, preferably about 1.35 to 1.7 times, more preferably about 1.4 to 1.7 times. As a result, the elongation of the polyester highly oriented undrawn yarn A and that of the polyester drawn yarn B are almost the same. Here, the draw ratio in the drawing step is the ratio of the surface speed of the first supply roller 1 to the surface speed of the first take-up roller 3 (stretch ratio=surface speed of first take-up roller 3/thickness of first supply roller 1). surface velocity). By drawing the polyester highly oriented undrawn yarn B, the single yarn fineness can be finely adjusted to a more preferable one, and the blend ratio of the polyester highly oriented undrawn yarn A and the polyester drawn yarn B can be finely adjusted to a more preferable one. You can also The highly oriented undrawn polyester yarn B is drawn while applying heat by installing a heater or the like. By heating with a heater, a drawn yarn B with stable yarn physical properties can be obtained.

When the draw ratio of the polyester highly oriented undrawn yarn B is less than 1.3 times, the elongation of the mixed entangled yarn as a whole increases, and in post-processing (for example, a series of processing including dyeing processing), inevitably The physical properties of the mixed entangled yarn tend to fluctuate due to the applied tension, which can be a cause of troubles in the quality of the woven or knitted product. On the other hand, when the draw ratio exceeds 1.7 times, yarn breakage tends to occur frequently.

In addition, instead of the above drawing process, polyester drawn yarn B having a single yarn fineness of 0.6 to 4.8 dtex, a total fineness of 18 to 96 dtex, an elongation of 15 to 60%, and a boiling water shrinkage of 20% or more is commercially available. etc., and the drawn polyester yarn B may be subjected to the mixed fiber entangling step. The drawn polyester yarn B to be prepared preferably has a single filament fineness of 0.8 to 3.8 dtex, a total fineness of 26 to 76 dtex, an elongation of 16 to 40%, and a boiling water shrinkage of 20 to 45%.

Next, a false twisting step is performed to falsely twist the polyester highly oriented undrawn yarn A under predetermined conditions. That is, the polyester highly oriented undrawn yarn A is false twisted under the conditions of a processing speed of 100 to 700 m/min and a draw ratio of 1.1 to 1.6 times. Specifically, as shown in FIG. 3, the polyester highly oriented undrawn yarn A is introduced into the second supply roller 4, passed through the heater 5 and the false twisting device 6, and pulled out from the second take-up roller 7 to obtain the polyester. A false twisted yarn A is obtained. Here, the area between the second supply roller 4 and the second take-up roller 7 shown in FIG. 3 becomes the composite false twist area. Specifically, the area between the second supply roller 4 and the false twister 6 is the twisting zone T1, and the area between the false twister 6 and the second take-up roller 7 is the untwisting zone T2.

In the false twisting process, the processing speed refers to the yarn speed when the yarn is pulled out from the second take-up roller 7 , that is, the surface speed of the second take-up roller 7 .

False twisting methods are generally classified into a spindle method and a friction method. Any of these methods can be adopted in the present invention. Generally, as the false twister 6, a pin type is used in the case of the spindle method, and a disk type is used in the case of the friction method.

In the false twisting process, the processing speed may be 100 to 700 m/min, but preferred false twisting conditions are slightly different between the spindle method and the friction method. For example, the working speed is preferably about 100 to 200 m/min for the spindle method, and about 200 to 700 m/min for the friction method. Further, the heater temperature is preferably about 150 to 200° C. in the case of the spindle method. On the other hand, in the case of the friction method, the range is preferably about 170 to 200° C. for the contact heater and about 200 to 300° C. for the point contact heater. If the heater temperature is below the above range, it will be difficult to impart sufficient crimps in any method. does not fully open, making it difficult to mix later.

Furthermore, the twisting/untwisting mechanism is slightly different between the spindle method and the friction method.

In the spindle method, the rotation of the spindle causes the pin-type false twister 6 to rotate, and the yarn is twisted. The degree of twisting at this time, that is, the false twist coefficient is preferably 20,000 to 34,000, more preferably 22,000 to 30,000. The false twist coefficient is calculated by the formula K=T×D ^1/2 . In the formula, K is the false twist coefficient, T is the number of false twists (T/M), and D is the total fineness (dtex) of the composite false twisted yarn. The number of false twists is calculated by T=spindle rotation speed (rpm)/surface speed of the second take-up roller 7 (m/min). If the false twist coefficient is less than 20,000, the crimp becomes weak and it becomes difficult to impart sufficient crimp to the false twisted yarn A. For this reason, it becomes difficult to form the above-described fine protrusions on the surface portion of the mixed entangled yarn contained in the water absorbent knitted fabric of the present invention. On the other hand, if the false twist coefficient exceeds 34000, the crimp shape becomes too dense, and the above-mentioned air retention layer is difficult to form on the surface portion of the mixed entangled yarn.

On the other hand, in the friction method, the degree of twisting is generally controlled not by the false twist coefficient, but by the K value and the number of discs. This is due to the difference in the twisting/untwisting mechanism of both types. The K value is the ratio (F2/F1) between the untwisting tension (F2) and the twisting tension (F1), where F2 is the yarn tension immediately after passing through the disc and F1 is the yarn tension introduced into the disc. It means the yarn tension just before. In the friction method, twisting occurs due to the rotation of the disc. Therefore, the degree of twisting is determined by the disc speed and the number of discs. However, direct management of the disk speed is not very efficient in terms of process control, so in view of the fact that the K value fluctuates due to fluctuations in the disk speed, it is generally more efficient to manage the K value. It is said that there is

In the friction system, a disk made of polyurethane is generally used. The number of discs is generally preferably 5 to 7, and the thickness of the disc is preferably 5 to 10 mm. Also, the K value is preferably 0.6 to 1.2. If the K value is less than 0.6, yarn breakage may increase and the false twisted yarn may have a lot of fluff. On the other hand, when it exceeds 1.2, surging tends to occur. Note that surging refers to a state in which twisted twists are not untwisted in the untwisting area and the twist remains.

In the false twisting step, the draw ratio may be 1.1 to 1.6 times, preferably about 1.1 to 1.55 times, more preferably about 1.15 to 1.5 times. The draw ratio in the false twisting step is the ratio of the surface speed of the second supply roller 4 to the surface speed of the second take-up roller 7 (stretch ratio=surface speed of the second take-up roller 7/surface speed of the second supply roller 4 ). If the draw ratio is less than 1.1 times, it becomes difficult to stabilize the quality of the polyester false twisted yarn A. On the other hand, if the draw ratio exceeds 1.6 times, it is not preferable because it causes frequent occurrence of fluff and yarn breakage in the false twisting process.

After the false twisting step, the polyester false twisted yarn A is guided to the fluid nozzle 8 together with the drawn polyester yarn B, and the fluid nozzle 8 is used to separate the drawn polyester yarn B and the polyester false twisted yarn A at an air pressure of 0.1 to 1.0 Mpa. The mixed fiber entangling process is performed under the condition that the difference in the overfeed rate of is 0 to 10.0%, and a heat-shrinkable mixed fiber entangled yarn is obtained. In the heat-shrinkable mixed entangled yarn, the yarn length of the polyester false-twisted yarn A is preferably longer than the yarn length of the drawn polyester yarn B by about 10% or less, more preferably by about 4 to 8%. If the polyester false-twisted yarn A is longer than the polyester drawn yarn B by more than 10%, the bulkiness of the heat-shrinkable mixed entangled yarn increases, so that the protrusions on the surface of the water-absorbing knitted fabric of the present invention become excessively large, resulting in water absorption. It is not preferable because it lowers the performance.

Fluid nozzles used in the mixing and entangling step are not particularly limited, but Tasrun nozzles or interlace nozzles are generally suitable. In addition, the overfeed rate at that time is preferably 1 to 5% in the aligning mixed fiber method of supplying at the same feeding rate (overfeed rate difference is 0%). In the so-called core/sheath mixed fiber method in which the supply speed is changed, the difference in overfeed rate between the polyester false twist yarn A and the drawn polyester yarn B is set to 1 to 7%, and the drawn polyester yarn B (core) is overfed. It is preferable to set the overfeed rate to 0.5 to 3.0% and the overfeed rate of polyester false twist yarn A (sheath) to 4.0 to 9.5%. The overfeed rate is defined as the overfeed rate = (V1 - V2) / V2 x 100 (%) where V1 is the yarn speed immediately before being introduced into the fluid nozzle and V2 is the yarn speed immediately after passing through the fluid nozzle. It is calculated by the following formula. In the case of FIG. 3, overfeed rate=(surface speed of first take-up roller 3−surface speed of third take-up roller 9)/surface speed of third take-up roller 9×100 (%), or overfeed rate=( It is calculated by the formula (surface speed of second take-up roller 7−surface speed of third take-up roller 9)/surface speed of third take-up roller 9×100 (%). By mixing and entangling the fibers under the above conditions, the air retention layer described above with the projections of the polyester fibers A is formed. If the conditions for the mixed fiber entanglement are outside the above range, the projections of the polyester fiber A in the water-absorbent knitted fabric of the present invention will not be of an appropriate size, and the surface portion of the mixed fiber entangled yarn will have the above-mentioned appearance. It becomes difficult to form an air retaining layer.

After passing through the third take-up roller 9 , the heat-shrinkable mixed entangled yarn is wound onto the package 11 by the take-up roller 10 . In addition, in the mixed fiber entangled yarn contained in the water absorbent knitted fabric of the present invention, it can be said that the mixed fiber entanglement is appropriately entangled when the entanglement number is in the range of about 90 to 300 pieces/m.

In general, the thicker the fiber, the stiffer the fiber, and the thinner the fiber, the more supple. By inserting the relatively thin polyester false-twisted yarn A into the large gaps generated between B, the polyester fiber A can be protruded from the surface portion of the mixed entangled yarn in the case of a woven or knitted fabric.

(grey machine manufacturing process)
In the greige fabric manufacturing process, the heat-shrinkable mixed entangled yarn is knitted to obtain a greige fabric. Knitting may be performed using a known knitting machine, and the preparation process prior to knitting may also use known equipment.

(Hot water shrinkage process)
In the hot water shrinkage treatment step, the raw fabric is immersed in hot water for a predetermined period of time to sufficiently heat shrink the drawn polyester yarn B to obtain a low-stretch knitted fabric. The hot water shrinkage treatment can be performed, for example, at about 80 to 135° C. for about 10 to 30 minutes. A polyester drawn yarn B prepared from a highly oriented polyester drawn yarn B having a boiling water shrinkage ratio within a specific range is subjected to a hot water shrinkage treatment to sufficiently heat shrink the polyester drawn yarn B and sufficiently maintain the protrusions. It can be a knitted fabric with reduced stretchability. The hot water shrinkage treatment step may be carried out during the scouring and dyeing processes. Specifically, the hot water shrinkage treatment step can be carried out as scouring treatment at about 80 to 120° C. for about 10 to 30 minutes, and as dyeing treatment at about 100 to 135° C. for about 10 to 30 minutes, more preferably. The scouring treatment can be performed at about 80 to 100° C. for about 10 to 30 minutes, and the dyeing treatment can be performed at about 120 to 135° C. for about 10 to 30 minutes. Also, scouring and dyeing may be performed together.

An example is shown below. First, the greige machine is scouring. The scouring may be carried out at a temperature of 80-130° C. by a continuous method or a batch method. Generally, it is preferable to carry out the dyeing by a batch method at a temperature of 100° C. or lower, and it is particularly preferable to use a high-pressure jet dyeing machine equipped with a jet nozzle. After scouring, presetting may be performed, if desired. The preset is usually subjected to dry heat treatment at 170° C. to 200° C. for 30 to 120 seconds using a pin tenter. After that, dyeing processing is carried out according to a conventional method. When cationic dyeable polyester is used as a constituent material, it may be dyed with a cationic dye. A final set may also be played if necessary.

In the manufacturing method of the present invention, the thickness of the water-absorbent knitted fabric is preferably 1.01 to 2.00 times the thickness of the gray fabric (obtained in the gray fabric manufacturing process), and preferably 1.20 to 1.0 times. More preferably 80 times. When it is 1.01 times or more, the polyester fiber B is sufficiently heat-shrunk, and the projections of the polyester fiber A are sufficiently maintained in the mixed entangled yarn, resulting in a knitted fabric with excellent water absorption and texture. . When it is 2.00 times or less, the obtained knitting does not become excessively stiff, and an appropriate texture can be embodied.

By subjecting the low-stretchable knitted fabric thus obtained to the water-absorbent processing step described later, the water-absorbent knitted fabric of the present invention can be obtained. can.

(Water absorption process)
In the water-absorbing process, the low-stretch knitted fabric is water-absorbent. For example, first, an aqueous solution containing a water absorbing agent is prepared, and then the aqueous solution is applied to a low-stretch knitted fabric based on a padding method, a spray method, a kiss roll coater method, a slit coater method, etc., and heated at 105 to 190 ° C. A dry heat treatment may be performed for 30 to 150 seconds. If necessary, the aqueous solution may contain a cross-linking agent, a softening agent, an antistatic agent, and the like. The water-absorbing knitted fabric of the present invention obtained after water-absorbing processing may be subjected to calendering or the like.

In addition, the water-absorbing process may be performed simultaneously with the dyeing process using an aqueous solution containing a water-absorbing agent and a dyeing agent in a dyeing bath.

(Lamination process of moisture-permeable waterproof layer and fiber fabric)
When laminating a moisture-permeable waterproof layer on the water-absorbent knitted fabric of the present invention, the moisture-permeable waterproof layer may be laminated according to a known method. Furthermore, when laminating the fiber fabric on the moisture-permeable and waterproof layer, the fiber fabric may be laminated according to a known method.

[Other processing]
The water-absorbent knitted fabric of the present invention is subjected to antibacterial treatment, dyeing treatment, water-repellent back water-absorbing treatment, UV-cut treatment, heat storage treatment, antibacterial treatment, antibacterial deodorant treatment, deodorant treatment, antifouling treatment, anti-mosquito treatment, calendering, When printing or the like is applied, these treatments may be performed before, at the same time as or after the water-absorbing process, or before or after the moisture-permeable waterproof layer lamination process.

The present invention will be specifically described below in accordance with examples. The invention is not limited to this example.

[Measurement method/evaluation method]
In Examples and Comparative Examples, 1. surface shape of mixed entangled yarn;2. Single filament fineness and total fineness of highly oriented undrawn yarn, drawn yarn and mixed entangled yarn;3. 4. elongation of highly oriented undrawn yarn; 4. entanglement number of mixed entangled yarn; 5. water absorption (height of water absorption according to the Byrek method); Mean deviation (SMD) of woven and knitted fabric surface roughness;7. The texture of the woven or knitted fabric was measured and evaluated by the following methods.

1. Surface shape of mixed fiber entangled yarn Using an optical microscope ("Microscope VHX-900" manufactured by Keyence Co., Ltd.), the surface shape of the mixed fiber entangled yarn is observed at 200 times in a free state, and the protrusions due to polyester fiber A are observed. is formed, and a layered portion (an air retaining layer that contributes to improving the texture) formed by loosely entangling the polyester fibers A in the surface portion of the mixed entangled yarn is formed. It was evaluated as "good", otherwise it was evaluated as "bad".

2. Single yarn fineness and total fineness of highly oriented undrawn yarn and mixed entangled yarn Single yarn fineness and total fineness of highly oriented undrawn yarn and mixed entangled yarn are based on the provisions of JIS L1013 8.3.1. It was measured.

3. Elongation of Highly Oriented Undrawn Yarn The elongation of the highly oriented undrawn yarn was measured based on JIS L1013 8.5.1.

4. Entanglement number of mixed fiber entangled yarn The entanglement number (pieces/m) of the mixed fiber entangled yarn was measured based on the JIS L1013 8.15 hook method.

5. Water absorption The water absorption height was measured based on the Byrek method described in JIS L 1907:2010 to evaluate the water absorption.

6. Mean deviation of woven and knitted surface roughness (SMD)
SMD was measured using an automated surface tester (“KESFB4-AUTO-A” manufactured by Kato Tech Co., Ltd.). First, a test piece of 20 cm square was taken, and the test piece to which a tension of 400 g was applied was placed in the above tester. Next, a vertical load of 50 g including the metal friction element is applied, the friction element is brought into contact with a force of 10 g by the contact pressure of the spring, and the test piece is moved back and forth 30 mm to measure the surface roughness of the test piece. variation was measured. Measurement was performed three times each in two directions, WARP and WEFT, and the average value was taken as SMD. SMD indicates the fluctuation of surface roughness, and it can be determined that the larger the value, the more unevenness is caused by the protrusions. The SMD was measured by moving the friction element in the longitudinal direction of the absorbent knitted fabric.

8. Texture of Woven or Knitted Fabric Five subjects evaluated the texture of the surface of the woven or knitted fabric, such as softness, smoothness, fullness, and resilience. It was judged according to the following criteria.
○: Four or more out of five subjects evaluated that the texture of the woven or knitted fabric was good.
Δ: 2 to 3 out of 5 subjects evaluated that the texture of the woven or knitted fabric was good.
x: Not more than 1 out of 5 subjects evaluated that the texture of the woven or knitted fabric was good.

[Production of water-repellent woven or knitted fabric]
(Example 1)
A polyester highly oriented undrawn yarn A having an elongation of 104%, a single filament fineness of 0.54 dtex, a boiling water shrinkage of 19.3%, and a total fineness of 45 dtex and 84 filaments was prepared. On the other hand, a polyester highly oriented undrawn yarn B having an elongation of 118%, a single filament fineness of 4.7 dtex, a total fineness of 56 dtex, 12 filaments, and a boiling water shrinkage of 22.3% was prepared. Then, the polyester highly oriented undrawn yarns A and B were subjected to the manufacturing process of the heat-shrinkable mixed-fiber entangled yarn as shown in FIG. A disc-type false twisting device 5 was used, and the conditions for composite false twisting and the entangling conditions for the mixed fibers were set as follows to obtain a heat-shrinkable mixed-fiber entangled yarn having an elongation of 26.6%.

<Stretching conditions>
Surface speed of first supply roller 1: 284 m/min Temperature of heater 2 (non-contact heater): 245°C
Draw ratio of polyester highly oriented undrawn yarn B: 1.6 times Surface speed of first take-up roller 3: 455 m/min

<False twisting conditions>
Surface speed of second supply roller 4: 367 m/min Temperature of heater 5 (contact heater): 160°C
Twisting direction: Z direction Structure of false twister 6 (disk): 1-6-1
Thickness of false twisting tool 6 (disk): 9 mm
K value: 1.0
Surface speed of second take-up roller 7: 477 m/min Draw ratio during false twisting: 1.3 times

<Mixed fiber entanglement conditions>
Surface speed of third take-up roller 9: 450 m/min Fluid nozzle 8: Taslan nozzle Air pressure: 0.735 MPa
Overfeed rate of polyester false twist yarn A: 6%
Overfeed rate of polyester drawn yarn B: 1%

Next, using a circular knitting machine (33 inches, 46 gauge) manufactured by Fukuhara Seiki Co., Ltd., the obtained mixed fiber entangled yarn is knitted in a jersey structure, and the knitting density is 60 courses / 2.54 cm, 48 A wale/2.54 cm circular knit fabric was obtained.

Next, using a liquid jet dyeing machine, the obtained gray fabric is washed in a bath (bath ratio 1:30) containing a scouring agent "Sunmol FL (trade name)" manufactured by Nicca Chemical Co., Ltd. at 80 ° C. Scouring for 30 minutes. After that, 1.0% o.d. m. f, 0.2 cc / L of acetic acid, 0.5 g / L of dispersing and leveling agent "Nikka Sun Salt SN-130 (trade name)" manufactured by Nicca Chemical Co., Ltd. and water absorbing agent "SR1801 ( (trade name)” at 3.0% o.o. m. The circular knitted fabric was subjected to water absorption and dyeing at 135° C. for 20 minutes with a water-absorbing/dyeing solution containing f (raw fabric: water-absorbing/dyeing solution at a weight ratio of 1:50). Thereafter, the circular knitted fabric was finish-set using a pin tenter to obtain a water-absorbing knitted fabric (knitting density: 94 courses/2.54 cm, 70 wales/2.54 cm, basis weight: 180 g/m ² ).

(Example 2)
The heat-shrinkable mixed fiber entangled yarn used in Example 1 was used on the front surface in an untwisted state, and the polyester false twisted yarn of 56 dtex 24 filaments was used on the back surface in an untwisted state. -H type, 33 inches, 32 gauge), a knitted fabric with a mesh structure having a knitting density of 45 courses/2.54 cm and 34 wales/2.54 cm was knitted. Using this knitted fabric, scouring, dyeing, and water-absorbing processing were performed in the same manner as in Example 1 to obtain a water-absorbing knitted fabric (knitting density: 78 courses/2.54 cm, 55 wales/2.54 cm). In this water-absorbent woven or knitted fabric, the mixing rate of the mixed fiber entangled yarn was 39% by mass.

(Comparative example 1)
The highly oriented undrawn yarn B used in Example 1 was changed to a polyester highly oriented undrawn yarn B having an elongation of 131%, a single filament fineness of 3.3 dtex, a total fineness of 45 dtex, 12 filaments, and a boiling water shrinkage of 5.1%. A water-absorbent knitted fabric (knitting density: 68 courses/2.54 cm, 50 wales/2.54 cm, weight per unit area: 140 g/m ² ) was obtained under the same conditions as in Example 1 except for this.

(Comparative example 2)
Water-absorbent knitted fabric (knitting density 70 courses / 2.54 cm, 60 wales/2.54 cm, basis weight of 140 g/m ² ) was obtained.

[Test results]
Tables 1 and 2 show the structures and evaluation results of the absorbent knitted fabrics of Examples and Comparative Examples. In addition, FIG. 1 shows an optical microscope photograph of the mixed fiber entangled yarn contained in the water absorbent knitted fabric obtained in Example 1, and FIG. Show pictures.

In the water absorbent knitted fabrics of Examples 1 and 2, the mixed fiber entangled yarn that constitutes has a continuous projection formed by loops and slacks of the polyester fiber A, and the inside of the projection (mixed fiber entangled yarn An air retaining layer formed by loosely intertwining fine polyester fibers A was formed on the inner side of the yarn. As shown in Table 1, the water-absorbing knitted fabrics of Examples 1 and 2 had excellent water-absorbing properties and feel.

On the other hand, in the water-absorbing knitted fabric of Comparative Example 1, since the mixed fiber entangled yarn formed using the polyester highly oriented undrawn yarn B with high hot water shrinkage is not used, the mixed fiber entangled yarn has fine protrusions. was not sufficiently formed, and the elongation rate of the knitted fabric was high, resulting in unsatisfactory water absorbency and feel.

In addition, in the absorbent knitted fabric of Comparative Example 2, since a general false twisted textured yarn was used instead of the mixed entangled yarn, the shape of the fiber surface was not formed with fine protrusions. As a result, the water absorption is inferior to that of . Furthermore, in the water-absorbing knitted fabric of Comparative Example 2, the touch of the surface was rough and hard, and the feeling of fullness and resilience was not sufficient, and a good feeling was not achieved.

YA Package of polyester highly oriented undrawn yarn A YB Package A of polyester highly oriented undrawn yarn B Highly oriented polyester undrawn yarn A
B Polyester highly oriented undrawn yarn B
1 First supply roller 2 Heater 3 First take-up roller 4 Second supply roller 5 Heater 6 False twister 7 Second take-up roller 8 Fluid nozzle 9 Third take-up roller 10 Winding roller 11 Package T1 Twisting zone T2 Untwisting zone

Claims (6)

A water-absorbing knitted fabric containing a mixed entangled yarn and having a water-absorbing agent attached to the surface,
The mixed entangled yarn consists of a polyester fiber A having a single yarn fineness of 0.2 to 0.9 dtex and a total fineness of 30 to 100 dtex, and a single yarn fineness of 1.0 to 5.0 dtex and a total fineness of 30 to 100 dtex. It is composed of polyester fiber B of
The single yarn fineness ratio (A/B) between the polyester fiber A and the polyester fiber B is 1/20 to 1/6,
The mass ratio (A/B) of the polyester fiber A and the polyester fiber B is 20/80 to 80/20,
A protruding portion is formed by the polyester fiber A on the surface portion of the mixed entangled yarn,
The number of entanglements of the mixed entangled yarn is 90 to 300/m,
The elongation rate (constant load method, load 14.7 N) measured according to JIS L 1096: 2010 is 120% or less,
A water-absorbent knitted fabric having a surface roughness mean deviation (SMD) of 1.5 to 6.5 μm according to the KES-F system. 2. The water- absorbing knitted fabric according to claim 1, which has a water absorption height of 101 mm or more as measured according to the Byrek method described in JIS L 1907:2010. The absorbent knitted fabric according to claim 1 or 2, wherein the number of entanglements of the mixed entangled yarn is 130 to 300/m. The absorbent knitted fabric according to any one of claims 1 to 3, wherein the knitting density is 55-150 courses/2.54 cm and 45-100 wales/2.54 cm. A method for producing the absorbent knitted fabric according to any one of claims 1 to 4,
A step of preparing a heat-shrinkable mixed entangled yarn having an elongation of 18 to 50%;
a step of knitting the heat-shrinkable mixed entangled yarn to produce a gray fabric;
a step of subjecting the gray fabric to a hot water shrinkage treatment to obtain a low-stretch woven or knitted fabric;
a step of water-absorbing the low-stretch knitted fabric to obtain the water-absorbent knitted fabric of the present invention;
A method for producing a water-absorbing knitted fabric, comprising: The step of preparing the heat-shrinkable mixed entangled yarn comprises:
(1) A polyester highly oriented undrawn yarn B having a single filament fineness of 1.0 to 10.0 dtex, a total fineness of 30 to 200 dtex, an elongation of 80 to 150%, and a boiling water shrinkage of 20% or more is drawn at a draw ratio of 1.0. A drawing step of drawing at 3 to 1.7 times to obtain a polyester drawn yarn B, or
A step of preparing a polyester drawn yarn B having a single yarn fineness of 0.6 to 4.8 dtex, a total fineness of 18 to 96 dtex, an elongation of 15 to 60%, and a boiling water shrinkage of 20% or more;
(2) Polyester highly oriented undrawn yarn A with a single yarn fineness of 0.20 to 1.44 dtex, a total fineness of 30 to 160 dtex, and an elongation of 80 to 150% is processed at a processing speed of 100 to 700 m / min and a draw ratio of 1. A false twisting step of false twisting under conditions of 1 to 1.6 times to obtain a polyester false twisted yarn A;
(3) The polyester false twisted yarn A and the drawn polyester yarn B are mixed with a fluid nozzle at an air pressure of 0.1 to 1.0 Mpa, and the overfeed rate of the polyester false twisted yarn A is higher than the overfeed rate of the drawn polyester yarn B. a mixed fiber entanglement step in which the mixed fiber entanglement is performed with a 4 to 10.0% higher overfeed rate difference;
including,
The method for manufacturing the absorbent knitted fabric according to claim 5.

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