JP2008202204A - Production method of ultrafine fiber fabric - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrafine fiber high density woven fabric high in cover factor and hardly causing slippage, and to provide a production method thereof. <P>SOLUTION: The ultrafine fiber fabric is a woven or knitted fabric using an ultrafine fiber having 1-500 nm number-average diameter and has 1,500-3,500 cover factor CF. The production method of the ultrafine fiber fabric comprises weaving or knitting by using an ultrafine fiber obtained by twisting a sea-island type conjugate fiber having 1-500 nm number-average island diameter and removing the sea component. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fabric using ultrafine fibers having a single fiber diameter of nanometer level, particularly a high-density fabric and a method for producing the fabric.

  Ultrafine fibers with a single fiber diameter of several μm or several hundreds of nanometers or less are thin and flexible, so that they enter into fine grooves and have high adsorption performance due to increased surface area, and are used as wiping cloths for precision equipment. Yes. Also, fabrics using these ultrafine fibers are often used as abrasives that require high smoothness because the fabric surface is smooth and the fabric surface can be smoothed. In addition, fine touch is preferred, and it has been developed as artificial leather and new tactile textile.

  Examples of a method for obtaining these ultrafine fiber fabrics include a method of making a sea-island type composite fiber or a split type composite fiber into a fabric and then desealing or splitting the fabric. Particularly, the ultrafine fiber having a single fiber diameter of 1 μm or less. In order to obtain this, a sea-island type composite fiber is used (Patent Document 1).

  However, in the method in which sea-island type composite fibers are subjected to sea removal treatment after forming a fabric, voids are formed by the amount of decomposition or dissolution of sea components and the fineness is reduced. Later density reduction was inevitable. In particular, in the woven fabric, there is a problem that the eyes become rough due to the reduction in the fineness, that is, the so-called cover factor is lowered, so that misalignment is likely to occur, wiping and polishing performance are deteriorated, and development of clothing applications is restricted. As means for solving this problem, it has been proposed to apply a high-pressure fluid to the ultrafine fiber fabric to disperse the ultrafine fiber bundle to increase the apparent density (Patent Documents 2, 3 and 4). However, although the apparent density is increased by this method, it is not sufficient for improving the misalignment because only the ultrafine fibers are scattered and the cover factor is not changed. Further, since the fabric yarns are entangled with each other and restrained, the fabric becomes inflexible and paper-like.

For the purpose of reducing the cover factor, a method of improving the cover factor by heat treating a fabric which is shrunk by heat or mixed / woven with a large fine fiber and a very fine fiber with latent crimpability is also being studied. (Patent Documents 5, 6 and 7). However, if the thick fiber deteriorates the polishing performance and the adsorption performance, or if the thick fiber is exposed on the surface, the substrate may be damaged during wiping, so that it cannot be applied as a wiping material for precision equipment.
In addition, although a method of shrinking an ultrafine fiber fabric with an organic solvent has been proposed (Patent Documents 8 and 9), it causes a decrease in strength due to solvent treatment, safety during production, product safety, and recent environmental problems. Given that, there was much room for improvement.
JP 2004-244758 A JP-A-60-39439 JP 61-39439 A JP-A-61-58573 Japanese Patent Laid-Open No. 2-89144 Japanese Patent Laid-Open No. 9-19393 Japanese Patent Laid-Open No. 10-212629 JP 56-154546 A JP 61-146840 A

  An object of the present invention is to provide a method for producing a high-density ultrafine fiber fabric, in particular, an ultrafine fiber high-density fabric having a high cover factor and less likely to cause misalignment, and a method for producing the same.

  In order to solve the above problems, the present invention mainly comprises the following configuration. That is, the present invention is “a woven fabric using ultrafine fiber bundles composed of ultrafine fibers having a number average diameter of 1 nm to 500 nm, and has a cover factor CF of 1500 to 3500” and “number average” “A method for producing an ultrafine fiber fabric, comprising knitting and weaving using an ultrafine fiber bundle obtained by twisting a sea-island type composite fiber having an island diameter of 1 nm to 500 nm and then removing the seawater”.

  The fabric of the present invention can be used as a wiping material or an abrasive for precision equipment such as computer-related equipment and optical equipment. In addition, since it is a high-density woven or knitted fabric made of ultrafine fibers that have a large cover factor and are less likely to slip or lose shape, it can be developed into clothing as a fine-grained new tactile texture.

  Hereinafter, the ultrafine fiber fabric according to the present invention will be described in detail together with desirable embodiments.

  The ultrafine fiber fabric in the present invention refers to all fabrics using ultrafine fibers, and particularly refers to woven fabrics and knitted fabrics (hereinafter collectively referred to as woven or knitted fabrics) using ultrafine fibers.

  It is important that the ultrafine fibers used in the present invention have a number average diameter of 1 to 500 nm. Thereby, the absolute strength of a single fiber is obtained. Moreover, since it is a nanometer level fiber, the surface area is large and the cohesive force between single yarns is high, and high strength can be obtained as an ultrafine fiber bundle. For example, when a woven or knitted fabric using ultrafine fiber bundles is used as a wiping material or an abrasive, single yarn breakage, fluff fall, and fiber bundle breakage can be suppressed, and a high woven / knitted fabric strength can be obtained. In addition, since it is a fiber bundle formed of ultrafine fibers, there is an advantage that it is difficult to be damaged during wiping and polishing, and the fibers penetrate into fine grooves to exhibit high wiping performance and obtain high smoothness.

  As an island diameter by the number average of sea-island type composite fibers, it is preferably 1 nm to 200 nm, more preferably 30 nm to 100 nm.

  In the present invention, the number average diameter of the ultrafine fibers can be determined as follows. That is, the cross section of the ultrafine fiber is observed at a transmission electron microscope (TEM) magnification of 40000 times, the diameter of 50 ultrafine fibers randomly extracted in the same cross section is obtained, and the number average is calculated.

In the ultrafine fiber used in the present invention, the area ratio of coarse fibers having a diameter larger than 500 nm is preferably 3% or less. Here, the area ratio of coarse fibers means the area ratio of coarse fibers (fibers having a diameter larger than 500 nm) to the whole ultrafine fibers, and is calculated as follows. That is, the diameter of the ultrafine fibers and di, the square of the sum ^{(d1 2 + d2 2 + ··} + d50 2) = Σdi calculates ² (i = 1~50). Moreover, the diameter of the coarse fiber larger than 500 nm in diameter is set to Di, and the sum of the squares (D1 ² + D22 +... + Dm ² ) = ΣDi ² (i = 1 to m) is calculated. By calculating the ratio of ΣDi ² to Σdi ² , the area ratio of coarse fibers to all ultrafine fibers can be obtained.

  In the ultrafine fibers used in the present invention, the area ratio of coarse fibers having a diameter larger than 500 nm is preferably 3% or less, more preferably 1% or less, and further preferably 0%. That is, this means that the presence of coarse fibers exceeding 500 nm is close to zero or not.

  Further, when the diameter of the ultrafine fibers is 200 nm or less, the area ratio of the fibers having a diameter larger than 200 nm is preferably 3% or less, more preferably 1% or less, and further preferably 0%. . In addition, when the number average diameter of the ultrafine fibers is 100 nm or less, the area ratio of the fibers having a diameter larger than 100 nm is preferably 3% or less, more preferably 1% or less, and further preferably 0%.

  By using such an ultrafine fiber bundle with few coarse fibers or no coarse fibers, it is difficult to damage during wiping and polishing, and a high-performance wiping material or abrasive can be obtained.

The fabric of the present invention preferably has a cover factor CF of 1500 to 3500, more preferably 1500 to 2800, still more preferably 1500 to 2500, and most preferably 1800 to 2200. When the fabric is a woven fabric, the cover factor CF has a warp density of X (lines / 2.54 cm), a weft number of the fabrics Y (lines / 2.54 cm), a warp fineness of D1 (dtex), and a weft fineness of Assuming that D2 (dtex), it is calculated by the following equation.
CF = X × D1 ^1/2 + Y × D2 ^1/2
When the fabric is a knitted fabric, the cover factor CF is regulated as follows in the present invention. That is, twice the number of courses per 2.54 cm (the number of loops in the weft direction of the loop) is X, the number of wales per 2.54 cm (the number of loops in the warp direction of the loop) is Y, and the fineness of the yarn used is D ( dtex), it is calculated by the following equation.
CF = (X + Y) × D ^1/2
Here, the cover factor CF is a coefficient representing the density of the woven or knitted fabric structure determined by the thickness of the yarn constituting the woven or knitted fabric and the yarn density. The larger the cover factor CF, the denser the woven or knitted fabric is packed. When the cover factor CF is less than 1500, the eyes are rough and the voids are increased, so that misalignment is likely to occur, and the feeling of tension and waist is poor in the texture of the woven or knitted fabric. On the other hand, when the cover factor CF exceeds 3500, it becomes difficult to knit or weave or the sliding resistance of the woven or knitted fabric increases, leading to a reduction in tearing strength.

  The twist coefficient k of the ultrafine fiber bundle used in the present invention is preferably 1500 to 15000. When the twist coefficient k of the ultrafine fiber bundle is 1500 or more, a sufficient binding force between the ultrafine fibers in the ultrafine fiber bundle is obtained, and the fiber is less likely to fall off. On the other hand, if the twist coefficient k is 15000 or less, the binding force between the ultrafine fibers in the ultrafine fiber bundle does not become too strong, and it is soft and very fine because it does not harden and aggregate like a single fiber. Since the ultrafine fibers on the surface of the fiber bundle are easily scattered, it is possible to uniformly hold the abrasive to be used on the fabric surface.

  As the twisted yarn form, single twist, various twists, covering in which another yarn is wound around the core yarn, or the like can be adopted. In particular, twists with a lower twist number and an upper twist number have less residual torque of the twisted yarn, and the filaments are untwisted within the twisted yarn, making it easy for the ultrafine fiber bundles and single fibers in the ultrafine fiber bundle to break apart. This is preferable because the wiping performance is improved.

  In the present invention, the total fineness of each ultrafine fiber bundle constituting the fabric is preferably 130 to 300 dtex. By setting it to 130 dtex or more, the absolute strength of the ultrafine fiber bundle can be obtained, and a sufficiently high tear and tensile strength can be obtained. Moreover, since the texture of a cloth is soft and the unevenness | corrugation of a cloth becomes small by setting it as 300 dtex or less, a high performance wiping material and abrasive cloth can be obtained.

  Next, the ultrafine fiber fabric manufacturing method of the present invention will be described in detail.

  The sea-island type composite fiber in the present invention is composed of two or more polymers having different solubility (including degradability) in liquids such as solvent, acid, alkali, and water (including hot water). A fiber having a structure having a sea component and a hardly soluble polymer as an island component, and there is no limitation on the fiber cross-sectional shape, the island cross-sectional shape, the number of islands, and the like.

  In the present invention, the production method of the sea-island type composite fiber is not particularly limited, and the sea component polymer and the island component polymer are separately melted and obtained by sea-island composite spinning. It can be obtained by melt spinning a polymer alloy obtained by mixing with an extrusion kneader, a pressure kneader or the like, or finely dividing with a static kneader. As an example of a production method for obtaining by the melt spinning method, for example, a known method described in JP-A No. 2004-169261 can be employed.

In particular, when a sea-island type composite fiber obtained by melt spinning a polymer alloy is used, a sea-island type composite fiber having a small number average island diameter can be obtained by setting the sea component area ratio S as high as 50 to 90%. Since the island components can be separated from each other, merging of the island components can be suppressed. The sea component area ratio S is more preferably 55 to 85%.
Here, the sea component area ratio S is calculated as follows. That is, the cross section of the sea-island type composite fiber was observed at a transmission electron microscope (TEM) magnification of 40000 times to obtain the sea component area sμm ² in the range of 4 μm ² (real image 64 cm ² ), and the ratio of sμm ^{2 to} 4 μm ² The sea component area ratio S can be obtained by calculating.

  It is important that the sea-island type composite fiber used in the present invention has a number average island diameter of 1 to 500 nm. As a result, the absolute strength of the single fiber obtained through the sea removal treatment to be performed later is obtained, and since the finally obtained fiber is also a nanometer level fiber, the surface area is large and the cohesive force between the single yarns is increased. Also, high strength can be obtained as an ultrafine fiber bundle. For example, when a woven or knitted fabric using ultrafine fiber bundles is used as a wiping material or an abrasive, single yarn breakage, fluff fall, and fiber bundle breakage can be suppressed, and a high woven / knitted fabric strength can be obtained. In addition, since it is a fiber bundle formed of ultrafine fibers, there is an advantage that it is difficult to be damaged during wiping and polishing, and the fibers penetrate into fine grooves to exhibit high wiping performance and obtain high smoothness.

  In addition, when trying to knit using a single fiber with a diameter of about 1 to 10 μm, which is generally called an ultrafine fiber, the surface area is larger than that of a normal fiber of 10 μm or more, and static electricity is likely to occur or the single fiber is scattered. Fluffing occurs, making process passing worse, making it difficult to weave and weave, but ultrafine fiber bundles obtained by sea-sealing sea-island composite fibers with an island diameter of 1 to 500 nm by number average are the surface area of single fibers Is extremely large and the cohesive strength between the single fibers is high, so that the single fibers are difficult to be separated into a bundle, which is like a single thread. Further, due to the high cohesive force, sea removal treatment can be performed in the state of yarn as in the present invention. Therefore, it is important that the island diameter by the number average of sea-island type composite fibers is 1 to 500 nm.

  As an island diameter by the number average of sea-island type composite fibers, it is preferably 1 nm to 200 nm, more preferably 30 nm to 100 nm.

  In this invention, the island diameter by the number average of sea island type composite fiber can be calculated | required as follows. That is, the cross section of the sea-island type composite fiber was observed at a transmission electron microscope (TEM) magnification of 40000 times, the diameter of 50 island components randomly extracted in the same cross section was obtained, and the number average was calculated. To do.

In the sea-island type composite fiber used in the present invention, the area ratio of coarse island components having an island diameter larger than 500 nm is preferably 3% or less. Here, the area ratio of the coarse island component means the area ratio of the coarse island component (island having a diameter larger than 500 nm) to the island component that becomes the ultrafine fiber after sea removal, and is calculated as follows. That is, the diameter of the island component and di, the square of the sum ^{(d1 2 + d2 2 + ··} + d50 2) = Σdi calculates ² (i = 1~50). Further, the diameter of the island component having a diameter larger than 500 nm is set to Di, and the sum of the squares (D1 ² + D2 ² +... + Dm ² ) = ΣDi ² (i = 1 to m) is calculated. By calculating the ratio of ΣDi ² to Σdi ² , the area ratio of coarse fibers to all ultrafine fibers can be obtained.

  In the sea-island type composite fiber used in the present invention, the area ratio of the coarse island component in the diameter range larger than 500 nm is preferably 3% or less, more preferably 1% or less, and still more preferably 0%. That is, this means that the presence of coarse island components exceeding 500 nm is close to zero or absent.

  Moreover, when the island diameter by the number average of sea-island type composite fibers is 200 nm or less, the area ratio of the island component larger than 200 nm is preferably 3% or less, more preferably 1% or less, and still more preferably 0%. That is. Moreover, when the island diameter by the number average of sea-island type composite fibers is 100 nm or less, the area ratio of the island component larger than 100 nm is preferably 3% or less, more preferably 1% or less, and still more preferably 0%. is there.

  By using such a sea-island type composite fiber, the ultrafine fiber bundle obtained after sea removal has extremely low mixing of coarse fibers. For this reason, the cohesive force between the single fibers becomes strong during sea removal or after sea removal, and the process passability during sea removal or weaving and weaving is improved.

  The sea-island composite fiber used in the present invention is preferably made of a thermoplastic polymer. Thereby, since the sea-island type composite fiber can be produced by using the melt spinning method, the productivity can be made extremely high. In addition, it is preferable to consist of a thermoplastic polymer over the whole ultrafine fiber in this invention. The thermoplastic polymer as used in the present invention is a polyester such as polyethylene terephthalate (hereinafter sometimes referred to as PET), polybutylene phthalate, polylactic acid (hereinafter sometimes referred to as PLA), or nylon 6 (hereinafter referred to as PLA). N6), polyamides such as nylon 66, polyolefins such as polystyrene and polypropylene (hereinafter also referred to as PP), polyphenylene sulfide (hereinafter also referred to as PPS), and the like. Many polycondensation polymers such as polyamide and those having a high melting point are more preferable. It is preferable that the melting point of the polymer is 165 ° C. or higher because the heat resistance is good. For example, the melting point is 170 ° C for PLA and 220 ° C for N6. Since sea removal will be performed later, the sea component polymer and the island component polymer have different solubility in solvents and water. Further, the polymer may contain additives such as particles, a flame retardant, and an antistatic agent. Further, other components may be copolymerized as long as the properties of the polymer are not impaired. Furthermore, a polymer having a melting point of 300 ° C. or less is preferable because of ease of melt spinning.

  In the present invention, it is important to twist the sea-island type composite fiber before sea removal. The ultrafine fibers obtained by sea removal are thin and have a large surface area, so they have a large interaction with other fibers, tending to become entangled between ultrafine fiber bundles during sea removal, and difficult to unwind after sea removal. However, such a problem can be solved by twisting before sea removal as in the present invention. In addition, when the sea-island type composite fiber is a multifilament, it is natural that a single strong yarn is obtained by twisting, but the convergence of single fibers in the multi-filament of the sea-island type composite fiber is increased. It is also possible to reduce the entanglement between the sea-island type composite fiber bundles.

  As for the twisted yarn form, one or two sea-island type composite fiber bundles are aligned and simply twisted, or two or more single-twisted yarns are aligned and twisted in the opposite direction to the single-twisted yarn (that is, Various twisted yarns (with an upper twist opposite to the twist), covering yarns in which other yarns are wound around the core yarn, and the like can be employed. In particular, various twisted yarns with a lower twist number and an upper twist number have less residual torque after twisting, and the filaments are untwisted in the twisted yarn. This is preferable because the wiping performance is improved.

  In the present invention, the twisting method is not particularly limited, and in consideration of the number of twists, the twisting form, the twisting tension, etc., an up twister such as an Italian twisting machine or a double twister, a down twister such as a ring twisting machine, a covering machine, and a Beldor twisting thread. It can be performed using a machine. Moreover, the composite twisting machine which combined these can also be employ | adopted.

  In this invention, it is preferable to twist so that the twist coefficient K of the sea-island type composite fiber before sea removal may be 2000-20000. In the case of various twisted yarns, it is preferable to twist the yarn so that the twist coefficient K of either the lower twist, the upper twist, or both is 2000 to 20000. When the twist coefficient K is 2000 or more and the multifilaments of the sea-island composite fibers are in a tight state, the binding force between the filaments and the islands within the filaments can be sufficiently obtained during sea removal, and between the sea-island composite fiber bundles Entanglement can be suppressed. On the other hand, when the twisting coefficient K exceeds 20000, the binding force between the filaments becomes too strong, and it becomes difficult for the seawater removal solvent to permeate and replace the filament during seawater removal, resulting in an increase in seawater removal ratio and processing time. The twist coefficient K of the sea-island type composite fiber before sea removal is more preferably 3000 to 17000, and further preferably 5000 to 15000.

The twist coefficient K is calculated by the following formula, where T (times / m) is the number of twists before sea removal and D (dtex) is the total fineness of the sea-island composite fibers.
K = T × D ^1/2
Moreover, it is preferable to twist the sea-island type composite fiber before sea removal so that the twist coefficient k after sea-sea type composite fiber is removed from seawater is 1500-15000. Since the twisting factor k is 1500 or more after sea removal, the binding force between filaments and filament islands can be sufficiently obtained during unwinding after sea removal. The entanglement can be suppressed, and the process passability of the unwinding process is improved. On the other hand, if the twist coefficient k exceeds 15000, the residual torque increases and handling becomes difficult.

  It is necessary to increase the sea component area ratio of the sea-island type composite fiber for obtaining a single fiber having a small island diameter as in the present invention, and it is preferably 50 to 90%. Since the total fineness d of the ultrafine fiber bundle obtained after sea removal decreases with respect to the total fineness D, it is preferable to set the number of twists in consideration of this.

The twist coefficient k is calculated by the following equation, where t (times / m) is the number of twists after sea removal, and d (dtex) is the total fineness of the ultrafine fiber bundle obtained by sea removal.
k = t × d ^1/2
As a means of sea-sealing the twisted sea-island type composite fiber, a method of immersing the sea-island type composite fiber yarn in a liquid such as a solvent, acid, alkali, water, etc. in which sea components dissolve (including decomposition) is adopted. However, it is preferable to use an aqueous liquid from the viewpoint of operability and product safety as the liquid for dissolving (including decomposing) sea components. In addition, the sea removal process of immersing sea-island type composite fiber yarn in a liquid that dissolves seawater components (including decomposition) is a yarn dyeing machine such as a cheese dyeing machine, a kite dyeing machine, or a package dyeing machine (Obermeier dyeing machine). However, when a cheese dyeing machine is used, the yarn does not move, only the liquid circulates and seawater can be removed, and entanglement between sea-island type composite fiber bundles is unlikely to occur. preferable.

  If the sea-island type composite fiber having a number average island diameter of 1 to 500 nm as in the present invention, the cohesive force between ultrafine fibers obtained by sea removal is strong even when the sea component ratio is high, and the ultrafine fiber bundle It is possible to escape from the sea in the state of yarn. In addition, the volume is usually reduced by the amount of sea removal, and the package of cheese and the like collapses during sea removal, but in the case of sea-island type composite fibers with an island diameter of 1 to 500 nm, the ultrafine fiber Because of the large surface area, it absorbs and swells the liquid that dissolves (including decomposes) the sea components, making it difficult for the apparent volume to change, so that the package does not collapse and can be unwound after sea removal. Therefore, by adopting the method of the present invention, an ultrafine fiber bundle can be obtained in a yarn state.

  In the present invention, it is preferable that the total fineness of the sea-island type composite fiber before sea removal is 50 to 500 dtex. Thereby, the absolute strength of the sea-island type composite fiber is obtained, and the processability of twisted yarn and sea removal is improved. In addition, sea island type composite fibers exceeding 500 dtex are likely to get entangled between ultra-fine fiber bundles, resulting in poor unwinding after de-sealing, or the total fineness of the ultra-fine fiber bundles obtained even if they can be unraveled However, as a woven or knitted fabric, a soft texture is sometimes not obtained, and even when trying to split this thick ultrafine fiber bundle, it is difficult to split the cohesive force between the ultrafine fibers strongly.

  In the present invention, it is preferable to design the sea-island type composite fiber before sea removal so that the total fineness of the ultrafine fiber bundle after sea-island type composite fiber is removed from the sea is 130 to 300 dtex. Thereby, the absolute strength of the ultrafine fiber bundle obtained through the sea removal treatment to be performed later is obtained, and the process passability during knitting and weaving is improved. Also, a woven or knitted fabric having a soft texture and having a sufficiently high tear and tensile strength can be obtained.

In the present invention, when weaving and weaving the ultrafine fiber bundle obtained by sea-sealing the sea-island type composite fiber, it is important to make the density as high as possible, but when weaving and weaving, the cover factor CF is set to 1500 to 3500. It is preferable to design, more preferably 1500 to 2800, even more preferably 1500 to 2500, and most preferably 1800 to 2200. Cover factor CF, when the fabric is a woven fabric, the warp density of the fabric is X (lines / 2.54 cm), the number of wefts of the fabric is Y (lines / 2.54 cm), the fineness of the warps is D1 (dtex), When the fineness is D2 (dtex), the following formula is used.
CF = X × D1 ^1/2 + Y × D2 ^1/2
When the fabric is a knitted fabric, the cover factor CF is defined as follows in the present invention. That is, twice the number of courses per 2.54 cm (the number of loops in the weft direction of the loop) is X, the number of wales per 2.54 cm (the number of loops in the warp direction of the loop) is Y, and the fineness of the yarn used is D ( dtex), the following formula is used.
CF = (X + Y) × D ^1/2
Here, the cover factor CF is a coefficient representing the density of the fabric structure determined by the thickness of the yarn constituting the fabric and the fabric density. The larger the cover factor, the denser the fabric. When the cover factor CF is less than 1500, the eyes are rough and the voids are increased, so that misalignment is likely to occur, and the feeling of tension and waist is poor in the texture of the woven or knitted fabric. On the other hand, when the cover factor CF exceeds 3500, weaving becomes difficult or the sliding resistance of the fabric increases, leading to a reduction in tear strength.

  When weaving and knitting the ultrafine fiber bundle, it is preferable to twist the same direction as the twisting direction applied to the sea-island type composite fiber before sea removal, that is, to twist the ultrafine fiber bundle. Thereby, the restraining force between the ultrafine fibers in the ultrafine fiber bundle can be improved, and the process passability during knitting and weaving can be improved. Also, as needed, to improve the processability during weaving, such as pasting polyvinyl alcohol or carboxymethyl cellulose to the ultrafine fiber bundle, or attaching an oil agent to improve yarn sliding during weaving. It can be carried out.

  Moreover, when weaving and knitting the ultrafine fiber bundle, it is preferable to twist the ultrafine fiber bundle in a direction opposite to the twist direction applied to the sea-island type composite fiber before sea removal. Thereby, it can be set as the textile fabric of a thread | yarn with a small twist coefficient, and it can be set as the wiping material with which the ultrafine fiber in an ultrafine fiber bundle is easy to disperse | distribute, and has high wiping performance.

  When twisted yarn is applied to the ultrafine fiber bundle before weaving and weaving, in order to reduce the residual torque, it is preferable to perform twisting set with wet heat or dry heat to suppress chatter during unwinding.

  In the present invention, the weaving and weaving method is not particularly limited. For weaving, a fly shuttle loom, a rapier loom, a water jet loom, an air jet loom, or the like can be used. It is preferable to suppress the occurrence of warp fluff by adding an agent. The weaving structure is not particularly limited. When used for wiping materials, etc., weaving with satin weaving or satin weaving with a large number of floating warps so that weaving fibers can be easily separated, or plain weaving when we want to prevent misalignment and deformation. Or can be set appropriately according to the purpose.

  Even in knitting, the knitting machine and the knitting structure are not particularly limited and may be appropriately set according to the purpose. However, since ultrafine fibers are used, fluff is likely to occur and yarn breakage is easily caused, so that tension is sufficiently controlled during weaving. It is preferable. A preferred range of tension is 0.08 to 0.12 cN / dtex.

  The ultra-fine fiber high-density woven or knitted fabric obtained by the production method of the present invention has both suppleness and high wiping property due to the fineness of the ultra-fine fiber and softness unique to the woven and knitted fabric, and is knitted and woven at a high density. Since the misalignment is difficult to occur, it can be used as a wiping material or precision polishing for precision equipment such as computer-related equipment and optical equipment. Further, since it is a high-density sheet using ultrafine fibers having a large surface area and high adsorptivity, it can be suitably used as a filter or an adsorbent. In addition, it is an ultrafine fiber high-density woven or knitted fabric that has a large cover factor and is less likely to be misaligned or deformed. Therefore, it can be applied to clothing applications as a fine-grained new tactile texture.

  Hereinafter, the present invention will be described in detail with reference to examples. In addition, the measuring method in an Example used the following method.

A. Polymer melt viscosity The polymer melt viscosity was measured with a Capillograph 1B manufactured by Toyo Seiki Seisakusho. The polymer storage time from sample introduction to measurement start was 10 minutes.

B. Melting | fusing point The peak top temperature which shows melting | dissolving of a polymer in 2nd run was made into melting | fusing point of a polymer using DSC-7 made from Perkin Elmer (Perkin Elmae). At this time, the rate of temperature increase was 16 ° C./min, and the sample amount was 10 mg.

C. Worcester spots of polymer alloy fibers (U%)
Measurement was performed in the normal mode at a yarn feeding speed of 200 m / min using a USTER TESTER 4 manufactured by Zerbegger Worcester.

D. SEM Observation Platinum was vapor-deposited on the sample and observed with an ultrahigh resolution electrolytic emission scanning electron microscope at magnifications of 1000 and 10,000.
SEM device: UHR-FE-SEM manufactured by Hitachi, Ltd.
E. Cross-sectional observation of ultrafine fibers by TEM Ultra-thin sections were cut in the cross-sectional direction of the fibers, and the cross-section of the ultrafine fibers was observed by a TEM at a magnification of 40000 times. Moreover, metal dyeing | staining was given as needed.
TEM apparatus: H-7100FA type manufactured by Hitachi, Ltd. Sea component area ratio S of sea-island type composite fiber
Using image processing software (WINROOF) from a photograph by TEM observation of the E section obtains the sea component area Esumyuemu ² ranging from 4 [mu] m ^2, and the sea component area ratio S by calculating the ratio of Esumyuemu ² for 4 [mu] m ² did.

G. Island diameter by number average of sea-island type composite fiber The island diameter of the fiber was calculated in terms of a circle using image processing software (WINROOF) from the photograph of TEM observation in section E above, and a simple average value was obtained. At this time, 50 island diameters randomly extracted in the same cross section were analyzed and used for calculation.

H. Coarse island area ratio of island component Using the diameter analysis of F above, each island diameter is di, and the sum of the squares (d1 ² + d2 ² +... + D150 ² ) = Σdi ² (i = 1 to 150) Is calculated. Moreover, the island diameter larger than 500 nm is set to Di, and the sum of the squares (D1 ² + D2 ² +... + Dm ² ) = ΣDi ² (i = 1 to m) is calculated. By calculating the ratio of ΣDi ² to Σdi ² , the area ratio of coarse islands in the entire island component was obtained.

I. Fineness A sea-island type composite fiber or ultrafine fiber bundle was weighed 10 m and weighed. This was performed on five samples (n = 5), and the average value thereof was defined as the fineness (dtex).

J. et al. Mechanical properties At room temperature (25 ° C.), an initial sample length = 200 mm, a pulling speed = 200 mm / min, and a load-elongation curve was obtained under the conditions shown in JIS L1013 (1999) 8.5.1. Next, the load value at the time of breaking was divided by the initial fineness, which was taken as the strength, the elongation at the time of breaking was divided by the initial sample length, and a strong elongation curve was obtained as the elongation.

[Production Example 1 of Ultrafine Fiber Bundle]
Melt viscosity 57 Pa · s (240 ° C., shear rate 2432 sec ⁻¹ ), melting point 220 ° C. nylon 6 (hereinafter, N6) 20% by weight, weight average molecular weight 120,000, melt viscosity 30 Pa · s (240 ° C., shear rate 2432 sec − 1) 80% by weight of poly L lactic acid (optical purity: 99.5% or more) having a melting point of 170 ° C. was melt-kneaded at 220 ° C. with a twin-screw extrusion kneader to obtain a polymer alloy chip. Here, the weight average molecular weight of poly L lactic acid was determined as follows. That is, THF (tetrahydrofuran) was mixed with the sample chloroform solution to obtain a measurement solution. This was measured at 25 ° C. using water permeation gel permeation chromatography (GPC) Waters 2690, and the weight average molecular weight was determined in terms of polystyrene. The melt viscosity of N6 at 262 ° C. and a shear rate of 121.6 sec ⁻¹ was 53 Pa · s. Further, the melt viscosity of this poly L lactic acid at 215 ° C. and a shear rate of 1216 sec ⁻¹ was 86 Pa · s. During kneading, N6 and copolymer poly (L-lactic acid) were weighed separately and supplied separately to the kneader.

  This polymer alloy chip was melted at a melting portion of 230 ° C. and led to a spin block having a spinning temperature of 230 ° C. Then, after the polymer alloy melt was filtered with a metal nonwoven fabric having a limit filtration diameter of 15 μm, it was melt-spun from a die having a die surface temperature of 215 ° C. and wound up. This was subjected to a stretching heat treatment with the temperature of the first hot roller being 90 ° C. and the temperature of the second hot roller being 130 ° C. At this time, the draw ratio between the first hot roller and the second hot roller was 1.5 times. The obtained polymer alloy fiber showed excellent properties of 62 dtex, 36 filament, strength 3.4 cN / dtex, elongation 38%, U% = 0.7%. Further, when a cross section of the obtained polymer alloy fiber was observed with a TEM, poly-L-lactic acid was sea, N6 was an island-island structure, and the number average diameter of the island N6 was 55 nm, and the island diameter was larger than 100 nm. The island ratio of the product was 0%, and it was a sea-island type composite fiber that is a precursor of N6 ultrafine fiber in which N6 was ultrafinely dispersed. The sea component area ratio S was 78%.

  Six obtained sea-island type composite fibers were combined, twisted at 1000 T / m in the Z direction (twisting coefficient K = 19287), rewound into a cheese shape, charged into a cheese dyeing machine and 98 ° C. Treated with a 5 wt% aqueous sodium hydroxide solution for 1 hour. Next, after washing with hot water at 60 ° C. for 5 minutes three times, dehydration drying was performed. As a result, 99% by weight or more of the poly-L lactic acid component in the sea-island composite fiber was hydrolyzed and removed, and an N6 ultrafine fiber bundle 1 having 76 dtex (twisting coefficient after sea removal k = 8775) was obtained. The processability at the time of unraveling was good without the cheese breaking during sea removal. As a result of analyzing this ultrafine fiber bundle from the TEM photograph, the number average diameter of the N6 ultrafine fiber was 60 nm, which is an unprecedented thinness, and the fiber composition ratio of the single fiber diameter larger than 100 nm was 0%.

[Production Example 2 of ultrafine fiber bundle]
102 dtex (twisting factor k = 10149 after sea removal) in the same manner as in manufacturing example 1 of the ultrafine fiber bundle, except that the number of yarns before twisting in the production example 1 of the ultrafine fiber bundle was changed to 8 (twisting coefficient K = 22221). N6 extra fine fiber bundle 2 was obtained.

[Production Example 3 of extra fine fiber bundle]
Production example 1 of an ultrafine fiber bundle except that N6 in Production Example 1 of the ultrafine fiber bundle was changed to N6 (45 wt%) having a melt viscosity of 212 Pa · s (262 ° C., shear rate 121.6 sec ⁻¹ ) and a melting point of 220 ° C. Similarly, melt kneading was performed to obtain a polymer alloy chip. Subsequently, this was melt-spun and stretched and heat treated in the same manner as in Production Example 1 for ultrafine fiber bundles to obtain polymer alloy fibers. The obtained polymer alloy fiber exhibited excellent properties of 67 dtex, 36 filaments, strength 3.6 cN / dtex, elongation 40%, U% = 0.7%. Further, when the cross section of the obtained polymer alloy fiber was observed with a TEM, as in Production Example 1 of the ultrafine fiber bundle, poly L-lactic acid was the sea, N6 was the island-island structure, and the number average diameter of the island N6 was An island ratio of 110 nm and an island diameter larger than 200 nm was 2%, and it was a sea-island type composite fiber in which N6 was ultrafinely dispersed. The sea component area ratio S was 52%.

  Three obtained sea-island type composite fibers were combined and twisted at 1000 T / m in the Z direction (twisting coefficient K = 14177). 99% by weight or more of the L lactic acid component was removed by hydrolysis to obtain an N6 ultrafine fiber bundle 3 having 93 dtex (twisting coefficient after sea removal k = 9695). The processability at the time of unraveling was good without the cheese breaking during sea removal. As a result of analyzing this ultrafine fiber bundle from a TEM photograph, the number average diameter of N6 ultrafine fibers is 120 nm, the fiber composition ratio of the single fiber diameter larger than 500 nm is 0%, and the single fiber diameter is greater than 200 nm. The ratio was 2%.

[Production Example 4 of Ultrafine Fiber Bundle]
124 dtex (twisting factor k = 11180 after sea removal) was performed in the same manner as in manufacturing example 3 of the ultrafine fiber bundle, except that the number of yarns before twisting in production example 3 of the ultrafine fiber bundle was changed to four (twisting coefficient K = 16371). N6 extra fine fiber bundle 4 was obtained.

[Production Example 5 of extra fine fiber bundle]
155 dtex (twisting coefficient k after sea removal k = 1290) in the same manner as in manufacturing example 3 of the ultrafine fiber bundle, except that the number of combined yarns before twisting in production example 3 of the ultrafine fiber bundle was changed to 5 (twisting coefficient K = 18303). N6 extra fine fiber bundle 5 was obtained.

[Production Example 6 of Ultrafine Fiber Bundle]
N6 extra fine fiber bundle 6 (twist factor k after sea removal) in the same manner as extra fine fiber bundle production example 3, except that the number of twists in extra fine fiber bundle production example 3 was 500 T / m (twist coefficient K = 7089). = 4848). The processability at the time of unraveling was good without the cheese breaking during sea removal.

[Production Example 7 of extra fine fiber bundle]
N6 extra fine fiber bundle 7 (twist factor k after sea removal) in the same manner as extra fine fiber bundle production example 4 except that the number of twists in extra fine fiber bundle production example 4 was 500 T / m (twist coefficient K = 8185). = 5590). The processability at the time of unraveling was good without the cheese breaking during sea removal.

[Production Example 8 of Ultrafine Fiber Bundle]
Two sea-island type composite fibers of Production Example 3 for producing ultrafine fiber bundles were combined and twisted in the S direction at 1200 T / m. Two of these yarns were combined and twisted in the Z direction at 800 T / m (twisting coefficient K = 13097) to obtain various twisted yarns. In the same manner as in Production Example 3 of the ultrafine fiber bundle, an N6 ultrafine fiber bundle 8 (twist coefficient after sea removal k = 8944) was obtained. The processability at the time of unraveling was good without the cheese breaking during sea removal.

[Production Example 9 of Ultrafine Fiber Bundle]
Production Example of Dispersion Except that N6 of Production Example 1 of ultrafine fiber bundle was changed to polypropylene (hereinafter, PP) (23 wt%) having a melt viscosity of 350 Pa · s (220 ° C., 121.6 sec ⁻¹ ) and a melting point of 162 ° C. 1 was melt-kneaded in the same manner as in 1 to obtain a polymer alloy chip. The melt viscosity of poly L lactic acid at 220 ° C. and 121.6 sec −1 was 107 Pa · s. This polymer alloy chip was melt-spun in the same manner as in Production Example 1 for an ultrafine fiber bundle at a melting temperature of 230 ° C., a spinning temperature of 230 ° C. (die surface temperature of 215 ° C.), and a single-hole discharge rate of 1.5 g / min. The obtained undrawn yarn was drawn at a drawing temperature of 90 ° C., a draw ratio of 2.7 times, and a heat setting temperature of 130 ° C., and subjected to drawing heat treatment in the same manner as in Production Example 1 of an ultrafine fiber bundle to obtain 110 dtex, 18 filament polymer alloy fiber. . When the cross section of the obtained polymer alloy fiber was observed with a TEM, poly-L-lactic acid showed a sea-island structure with PP as an island, and the number average diameter of the island PP was 240 nm, and the island diameter was larger than 500 nm. The island ratio was 0%, and it was a sea-island type composite fiber in which PP was finely dispersed. The sea component area ratio S was 64%.

  Three obtained sea-island type composite fibers were combined, twisted at 1000 T / m in the Z direction (twisting coefficient K = 18166), and the same as in Production Example 1 of the ultrafine fiber bundle, 99% by weight or more of the L lactic acid component was removed by hydrolysis to obtain a PP ultrafine fiber bundle 9 having 78 dtex (twisting coefficient after sea removal k = 8888). The processability at the time of unraveling was good without the cheese breaking during sea removal. As a result of analyzing this fiber bundle from a TEM photograph, the number average diameter of PP ultrafine fibers was 240 nm, and the fiber ratio of single fiber diameters larger than 500 nm was 0%.

[Manufacturing Example 10 of Ultrafine Fiber Bundle]
78 dtex (twisting coefficient k after sea removal = 10247) in the same manner as in manufacturing example 9 of the ultrafine fiber bundle, except that the number of combined yarns before twisting in production example 9 of the ultrafine fiber bundle was changed to 4 (twisting coefficient K = 20976). ) PP ultrafine fiber bundle 10 was obtained.

[Production Example 11 of Ultrafine Fiber Bundle]
Melt viscosity 280Pa · s (300 ℃, 1216sec -1) polyethylene terephthalate (hereinafter, PET) of 80 wt%, polyphenylene sulfide (hereinafter, PPS) and 20 weight melt viscosity 160Pa · s (300 ℃, 1216sec -1) %, Melt kneading was performed using a biaxial extrusion kneader to obtain a polymer alloy chip. Here, the PPS used was a linear type and the molecular chain terminal was replaced with calcium ions.

  The polymer alloy chip obtained here was guided to a spinning machine in the same manner as in Production Example 1 for ultrafine fiber bundles, and spinning was performed. At this time, the polymer alloy melt was filtered with a metal nonwoven fabric having a spinning temperature of 315 ° C. and a limit filtration diameter of 15 μm, and then melt-spun from a die having a die surface temperature of 292 ° C. The discharged yarn was wound up at 1000 m / min via a non-heated first take-up roller and a second take-up roller after the process oil was supplied. The spinnability at this time was good, and there was no yarn breakage during continuous spinning for 24 hours. This was subjected to a stretching heat treatment with the temperature of the first hot roller being 100 ° C. and the temperature of the second hot roller being 130 ° C. At this time, the draw ratio between the first hot roller and the second hot roller was 3.3 times. The obtained polymer alloy fiber exhibited excellent properties of 60 dtex, 36 filaments, strength 4.4 cN / dtex, elongation 27%, U% = 1.3%. Moreover, when the cross section of the obtained polymer alloy fiber was observed with a TEM, the islands with PET as the sea and PPS as the islands, and the number average diameter of the islands PPS was 65 nm, and the island diameter was larger than 100 nm. The ratio was 0%, and it was a sea-island type composite fiber in which PPS was finely dispersed. The sea component area ratio S was 83%.

  Six obtained sea-island type composite fibers were combined, twisted at 1000 T / m in the Z direction (twisting coefficient K = 18974), and PET in the sea-island composite fiber was produced in the same manner as in Production Example 1 of the ultrafine fiber bundle. 99% by weight or more of the components were removed by hydrolysis to obtain a PPS ultrafine fiber bundle 11 having 74 dtex (twisting coefficient after sea removal k = 8660). The processability at the time of unraveling was good without the cheese breaking during sea removal.

[Production Example 12 of Ultrafine Fiber Bundle]
98 dtex (twisting coefficient k after seawater removal = 9950) in the same manner as in manufacturing example 11 of the ultrafine fiber bundle, except that the number of combined yarns before twisting in the production example 11 of the ultrafine fiber bundle was set to 8 (twisting coefficient K = 2909). ) PPS ultrafine fiber bundle 12 was obtained.

[Manufacturing Example 13 of Ultrafine Fiber Bundle]
Using seawater-type copolyester resin 60% by weight for the sea component and 40% by weight N6 resin for the island component, the island component is 100 islands by melt spinning. After the preparation, it was stretched 2.5 times to obtain a sea-island composite fiber having a single yarn fineness of 2.1 dtex, a total fineness of 38 dtex, and 18 filaments. The strength of this sea-island type composite fiber was 2.6 cN / dtex, and the elongation was 35%.

  Five obtained sea-island composite fibers were combined and twisted at 1000 T / m in the Z direction (twisting coefficient K = 13784), and the PET in the sea-island composite fibers was made in the same manner as in Production Example 1 of the ultrafine fiber bundle. 99% by weight or more of the components were hydrolyzed and removed, and an ultrafine fiber bundle 13 having 78 dtex (twisting coefficient after sea removal k = 8888) was obtained. Locations that collapsed on the edge of the cheese during sea removal were observed, and many yarn breaks occurred during unwinding. Moreover, the single yarn was scattered from the fiber bundle, and fluff was recognized. When the average single fiber fineness of the obtained ultrafine fibers was analyzed from the TEM photograph, it was 0.02 dtex (average fiber diameter 2 μm).

[Production Example 14 of Ultrafine Fiber Bundle]
109 dtex (twisting factor k = 10488 after sea removal) in the same manner as in manufacturing example 13 of the ultrafine fiber bundle, except that the number of yarns before twisting in the fiber bundle production example 13 was 7 (twisting coefficient K = 16310). The ultrafine fiber bundle 14 was obtained.

<Example 1>
To the ultrafine fiber bundle 1 obtained in Production Example 1 of the ultrafine fiber bundle, 5% to 8% by weight of a paste obtained by dissolving 6% by weight of polyvinyl alcohol in 60 ° C. water was adhered, and the dried one was used as a warp. The ultra-fine fiber bundle 2 obtained in Production Example 2 of the ultra-fine fiber bundle is applied to a fly shuttle loom as a weft and is made into a plain weave (cover factor CF1962) with a warp density of 115 / 2.54 cm and a weft density of 95 / 2.54 cm. An ultrafine fiber high-density fabric was obtained. When this was used to wipe a glass plate coated with petrolatum thinly, it showed excellent wiping performance and no scratches were observed on the glass plate.

<Example 2>
Using the ultrafine fiber bundle 3 obtained in Production Example 3 of the ultrafine fiber bundle as a warp and using the ultrafine fiber bundle 4 obtained in Production Example 4 of the ultrafine fiber bundle as a weft, a warp density of 105 / 2.54 cm, a weft density An ultrafine fiber high-density woven fabric was obtained in the same manner as in Example 1 except that 90 pieces / 2.54 cm plain weave (cover factor CF2015) was used. When this was used to wipe a glass plate coated with petrolatum thinly, it showed excellent wiping performance and no scratches were observed on the glass plate.

<Example 3>
In the same manner as in Example 2, except that the ultrafine fiber bundle 6 obtained in Production Example 6 of the ultrafine fiber bundle was used as a warp and the ultrafine fiber bundle 7 obtained in Production Example 7 of the ultrafine fiber bundle was used as a weft. A fiber high density fabric was obtained. When this was used to wipe a glass plate coated with petrolatum thinly, it showed excellent wiping performance and no scratches were observed on the glass plate.

<Example 4>
Except for using the ultrafine fiber bundle 8 obtained in Production Example 8 of the ultrafine fiber bundle for warp and weft, a plain weave (cover factor CF2060) having a warp density of 95 / 2.54 cm and a weft density of 90 / 2.54 cm was used. In the same manner as in Example 1, a fine fiber high-density fabric was obtained. When these were used to wipe a glass plate coated with petrolatum thinly, the ultrafine fibers were easily dispersed and showed excellent wiping performance. Further, no scratch was observed on the glass plate.

<Example 5>
In the same manner as in Example 1, except that the ultrafine fiber bundle 9 obtained in Production Example 9 of the ultrafine fiber bundle was used as a warp, and the ultrafine fiber bundle 10 obtained in Production Example 10 of the ultrafine fiber bundle was used as a weft. A high-density fiber fabric (cover factor CF1985) was obtained. When this was used to wipe a glass plate coated with petrolatum thinly, it showed excellent wiping performance and no scratches were observed on the glass plate.

<Example 6>
In the same manner as in Example 2, except that the ultrafine fiber bundle 11 obtained in Production Example 11 of the ultrafine fiber bundle was used as a warp and the ultrafine fiber bundle 12 obtained in Production Example 12 of the ultrafine fiber bundle was used as a weft. A high-density fiber fabric (cover factor CF1929) was obtained. When this was used to wipe a glass plate coated with petrolatum thinly, it showed excellent wiping performance and no scratches were observed on the glass plate.

  <Comparative Example 1> Example 1 except that the ultrafine fiber bundle 13 obtained in Production Example 13 of the ultrafine fiber bundle was used as the warp and the ultrafine fiber bundle 14 obtained in Production Example 14 of the ultrafine fiber bundle was used as the weft. Similarly, an ultrafine fiber high-density fabric (cover factor CF1985) was obtained. Wiping a thin glass plate with petrolatum using this, it took time to wipe.

<Comparative example 2>
Two sea-island type composite fibers obtained in Production Example 2 of ultrafine fiber bundle are combined and twisted at 1000 T / m in the Z direction (twisting coefficient 11576), and this is used as warp and weft without sea removal. A high density woven fabric of sea-island type composite fibers was obtained in the same manner as in Example 1 except that a plain weave (cover factor CF2084) having a warp density of 90 / 2.54 cm and a weft density of 90 / 2.54 cm was used. This was charged into a drum dyeing machine and treated with a 5 wt% aqueous sodium hydroxide solution at 98 ° C. for 1 hour. Next, after washing with hot water at 60 ° C. for 5 minutes three times, dehydration drying was performed. As a result, 99% by weight or more of the poly-L lactic acid component in the sea-island composite fiber was hydrolyzed and removed to obtain a woven fabric (cover factor CF1418) of ultrafine fibers. The resulting woven fabric was thinned by the amount of sea components decomposed during sea removal, the cover factor CF was small, and misalignment was likely to occur.

<Example 7>
The ultrafine fiber bundle 3 and the ultrafine fiber bundle 4 of Example 2 were additionally twisted in the S direction by 1000 T / m (that is, 1000 T / m in the Z direction twisted before sea removal was untwisted) and dried at 70 ° C. A high-density knitted fabric was obtained in the same manner as in Example 2 except that the one set for 1 hour was used. The process passability was good during weaving. When these were used to wipe a glass plate coated with petrolatum thinly, the ultrafine fibers were easily dispersed and showed excellent wiping performance. Further, no scratch was observed on the glass plate.

<Example 8>
The fabric at the time of weaving in Example 2 was tailored into a woven fabric having a 2/2 twill structure to obtain an ultrafine fiber high-density fabric. When these were used to wipe a glass plate coated with petrolatum thinly, excellent wiping performance was exhibited and no scratches were observed on the glass plate.
<Example 9>
A high-density knitted fabric was obtained in the same manner as in Example 2 except that plain weave (cover factor CF1694) having a warp density of 135 / 2.54 cm and a weft density of 125 / 2.54 cm was used. The process passability was good during weaving. When these were used to wipe a glass plate coated with petrolatum thinly, it showed excellent wiping performance and no scratches were observed on the glass plate.

<Example 10>
Using the ultrafine fiber bundle 5 obtained in Production Example 5 of the ultrafine fiber bundle, a high-density knitted fabric having a knitting structure of tengu, wales 43, and course 40 (cover factor CF1531) was obtained using a 28G circular knitting machine. When this was used to wipe a glass plate coated with petrolatum thinly, it showed excellent wiping performance and no scratches were observed on the glass plate.

  The ultrafine fiber fabric obtained by the production method of the present invention has both suppleness and high wiping property due to the fineness of the ultrafine fibers and softness unique to the woven and knitted fabric, and is knitted and woven at high density. Therefore, it can be used as a wiping material or precision polishing for precision equipment such as computer-related equipment and optical equipment. Further, since it is a high-density sheet using ultrafine fibers having a large surface area and high adsorptivity, it can be suitably used as a filter or an adsorbent. In addition, it is an ultrafine fiber high-density fabric that has a large cover factor and is resistant to misalignment and loss of shape. Therefore, it can be used for clothing as a fine, new tactile texture.

Claims (12)

An ultrafine fiber fabric, which is a woven or knitted fabric using an ultrafine fiber bundle made of ultrafine fibers having a number average diameter of 1 nm to 500 nm, and has a cover factor CF of 1500 to 3500. The ultrafine fiber fabric according to claim 1, wherein the twist coefficient k of the ultrafine fiber bundle is 1500 to 15000. The ultrafine fiber fabric according to claim 1 or 2, wherein the area ratio of the ultrafine fibers having a fiber diameter larger than 500 nm in the entire ultrafine fibers is 3% or less. The ultrafine fiber fabric according to any one of claims 1 to 3, wherein the twisted yarn is of various twists. The ultrafine fiber fabric according to any one of claims 1 to 4, wherein the total fineness of the ultrafine fiber bundle is 130 to 300 dtex. A method for producing an ultrafine fiber fabric, comprising knitting and weaving an ultrafine fiber bundle obtained by twisting a sea-island type composite fiber having a number average island diameter of 1 nm to 500 nm and then desealing. The method for producing an ultrafine fiber fabric according to claim 6, wherein the twisting coefficient K of the sea-island composite fiber before sea removal is 2000 to 20000. The method for producing an ultrafine fiber fabric according to claim 6 or 7, wherein the sea component area ratio S of the sea-island type composite fiber is 50 to 90%. The method for producing an ultrafine fiber fabric according to any one of claims 6 to 8, wherein an area ratio of an island component larger than an island diameter of 500 nm occupying in the entire island component is 3% or less. The method for producing an ultrafine fiber fabric according to any one of claims 6 to 9, wherein the twisted yarn is a plied yarn. The method for producing an ultrafine fiber fabric according to any one of claims 6 to 10, wherein the total fineness of the sea-island type composite fiber is 50 to 500 dtex. The method for producing an ultrafine fiber fabric according to any one of claims 6 to 11, wherein the fabric is knitted and woven so that the cover factor CF of the woven or knitted fabric knitted and woven from the ultrafine fiber fabric is 1500 to 3500.