JP2009256863A - Composite fabric - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite fabric which suppresses air permeability, ensures proper moisture permeability, and furthermore has softness, and to provide a method for producing the same. <P>SOLUTION: The composite fabric is obtained by directly laminating a nanofiber nonwoven fabric formed of ultrafine fibers each having a diameter of a cross-section of not less than 50 nm and less than 1.5 μm in the longitudinal direction of the fiber on at least one side of a sheet shape substrate; and the method for producing the composite fabric includes a process for directly electric-field spinning on at least one side of the sheet-like substrate to laminate the nanofiber nonwoven fabric formed of the ultrafine fibers each having a diameter of a cross-section of not less than 50 nm and less than 1.5 μm in the longitudinal direction of the fiber to the sheet-like substrate. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a composite fabric composed of a nanofiber nonwoven fabric and a sheet-shaped body. More specifically, the present invention relates to a composite fabric in which the feeling of stuffiness is reduced by suppressing heat transfer by suppressing breathability and ensuring good moisture permeability.

  Until now, various fabrics having windproof properties and high moisture permeability (and water repellency) for the purpose of keeping the environment in clothes (including gloves) comfortable have been reported. For example, Patent Document 1 discloses a laminate of a porous sheet and a fiber sheet using a thermoplastic elastomer. Patent Document 2 discloses a laminate in which a moisture-permeable and waterproof resin and ultrafine fibers are combined.

  However, the fabrics obtained by the conventional techniques as described above have both properties such as insufficient wind permeability for wind resistance or insufficient wind resistance if sufficient moisture permeability is obtained. It was hard to say. In addition, since the sheets are laminated using the adhesive layer, there are various problems such as a heavy fabric and a poor feeling of wear because the flexibility of the fiber sheet is impaired. Furthermore, the production method also requires the production of a windproof and moisture-permeable sheet and the lamination / adhesion step to the fiber sheet, so that there are problems such as a large number of steps and inferior productivity.

JP 2002-54009 A Japanese Patent Laid-Open No. 5-230770

  The main object of the present invention is to provide a composite fabric having windproof properties, moisture permeability, and softness, and a method for producing the same.

  As a result of intensive studies to solve the above problems, the inventors of the present invention laminated the nanofiber nonwoven fabric directly on a sheet-shaped body such as a knitted fabric, thereby suppressing air permeability and improving heat retention. It has been found that a composite fabric having a sufficient moisture permeability can be obtained. Furthermore, it has been found that such a composite fabric does not impair the suppleness of the fabric used as a sheet-shaped body. The present invention has been completed as a result of further studies based on these findings.

The present invention provides the following composite fabric and method for producing the same.
Item 1. A composite fabric obtained by directly laminating a nanofiber nonwoven fabric composed of ultrafine fibers having a diameter in a direction perpendicular to the fiber axis of 50 nm or more and less than 1.5 μm on at least one surface of a sheet-shaped body.
Item 2. Item 2. The composite fabric according to Item 1, wherein the sheet-shaped body is a woven fabric, a knitted fabric, or a nonwoven fabric.
Item 3. Item 3. The composite fabric according to Item 1 or 2, wherein the component constituting the nanofiber nonwoven fabric is a urethane-based elastomer.
Item 4. The composite fabric according to claim 3, wherein the same component as that constituting the nanofiber nonwoven fabric is exposed at a surface ratio of 45% or more on the surface on which the nanofiber nonwoven fabric of the sheet shape is laminated.
Item 5. Item 5. The composite fabric according to any one of Items 1 to 4, wherein the nanofiber nonwoven fabric is laminated on a sheet-shaped body by an electrospinning method.
Item 6. Claim airflow resistance by KES-F8-AP1 is at 0.2 KPa · s / m or more and moisture permeability, characterized in that at 3000cm ³ / 24h · ^{m 2} or more in JIS L 1099 A-2 Method 1 The composite fabric in any one of -4.
Item 7. The composite fabric according to any one of claims 1 to 6, which is in the form of a glove or an inner wear.
Item 8. A step of directly performing electrospinning on at least one surface of the sheet-shaped body, and laminating a nanofiber nonwoven fabric made of ultrafine fibers having a diameter in the direction perpendicular to the fiber axis of 50 nm or more and less than 1.5 μm on the sheet-shaped body. A method for producing a composite fabric comprising:

  ADVANTAGE OF THE INVENTION According to this invention, the comfortable composite fabric which has moderate moisture permeability can be provided, suppressing air permeability. More specifically, the composite fabric of the present invention can keep the humidity in the garment moderate while suppressing direct external air contact with the skin. Further, the composite fabric of the present invention is not too heavy, and when a knitted fabric is used as the sheet-shaped body, the flexibility and stretchability peculiar to the knitted fabric are not impaired. The composite fabric of the present invention having such properties is useful as a material for clothes, particularly gloves and underwear. A garment using the composite fabric of the present invention is excellent in windproof properties and heat retaining properties and has no discomfort due to stuffiness or weight, so that the garment can be kept comfortable even when the outside air temperature is low.

  Furthermore, the manufacturing method of the composite fabric of the present invention has a shorter manufacturing process than the conventional method, and can efficiently provide the composite fabric of the present invention with fewer steps.

The typical example of the scanning electron micrograph which confirmed welding of the polyurethane nanofiber and the sheet-shaped body (knitted fabric of cotton yarn and polyurethane fiber) is shown. The schematic of the slit method used for the bending resistance measurement is shown.

1. Composite Fabric The composite fabric of the present invention is obtained by directly laminating a nanofiber nonwoven fabric composed of ultrafine fibers having a diameter in the direction perpendicular to the fiber axis of 50 nm or more and less than 1.5 μm on at least one side of a sheet-shaped body. is there. The configuration of the present invention will be described in detail below.

(1) Sheet-shaped body The composite fabric of the present invention has a form in which the nanofiber nonwoven fabric is directly laminated on at least one surface of the front or back surface of the sheet-shaped body without using an adhesive (or adhesive layer). Have.

  The sheet-shaped body used in the present invention is not particularly limited as long as it has flexibility such as woven fabric, knitted fabric, and nonwoven fabric. The degree of flexibility can be appropriately selected according to the application.

  Since the composite fabric of the present invention directly forms (laminates) the nanofiber nonwoven fabric on the sheet-shaped body, the material (component) of the sheet-shaped body is the same material (component) as the material (component) constituting the nanofiber nonwoven fabric. ), Or a material (component) that can be dissolved in the same solvent as the material (component) constituting the nanofiber nonwoven fabric (in this specification, “the same material as the nanofiber nonwoven fabric or the same material as the nanofiber nonwoven fabric”). May be referred to as “a material that can be dissolved in a solvent of the above”). That is, when the material of the nanofiber nonwoven fabric is polyurethane, a material that can be dissolved in polyurethane or a solvent (for example, N, N-dimethylformamide) in which polyurethane is dissolved is selected as the sheet shape body.

  The material for the sheet-shaped body can be selected from conventionally known materials. When the sheet-shaped body is a knitted fabric, a material that can be used for clothing and the like, and a material that is the same as the nanofiber nonwoven fabric or a material that can be dissolved in the same solvent as the material of the nanofiber nonwoven fabric can be used in combination. . Moreover, you may use combining the raw material which can be melt | dissolved in the same raw material as a nanofiber nonwoven fabric, or the raw material of a nanofiber nonwoven fabric.

  Examples of such materials include plant fibers such as cotton and hemp, and natural fibers such as animal hair fibers such as wool, and cotton and wool are preferable from the viewpoint of touch and heat retention. Also, recycled fibers such as cupra, rayon, acetate, polynosic, lyocell, etc. can be used. These materials can be used alone or in combination of two or more. Since vegetable fiber and animal hair fiber are usually insoluble in the solvent for producing the nanofiber nonwoven fabric, it is desirable to combine them with the following synthetic fiber, elastomer fiber and the like.

  Synthetic fibers include, for example, polyester (for example, polyethylene terephthalate (PET), polyester with hydrophilicity, etc.), polyacrylonitrile, polyamide (for example, nylon fibers such as nylon-6, nylon-66, etc.), polychlorinated Examples include those composed of resins such as vinyl, polyvinylidene chloride, polyurethane (for example, spandex, etc.), polyolefin (for example, polypropylene, etc.), preferably polyurethane, polyolefin (preferably polypropylene), polyamide (preferably nylon- 6). These materials can be used alone or in combination of two or more.

  Moreover, a thermoplastic elastomer fiber can also be used as a raw material for the sheet-shaped body. The thermoplastic elastomer fiber may be appropriately selected from conventionally known fibers, and examples thereof include styrene elastomers, olefin elastomers, urethane elastomers, vinyl chloride elastomers, polyester elastomers, polyamide elastomers, and the like. Are urethane elastomers and polyamide elastomers. As the urethane elastomer, Pandex, Desmopan manufactured by DIC Bayer Polymer Co., Ltd., Nisshinbo Mobilon manufactured by Nisshinbo Co., Ltd., etc. are distributed as commercial products and can be obtained commercially. Also, as polyamide-based elastomers, Pebax manufactured by Atofina Japan, Grilon ELX, Grillamide ELY manufactured by Ems Showa Denko, Diamide manufactured by Daicel Dexa, and Vestamide are distributed as commercial products. can do. These materials can be used alone or in combination of two or more.

  When the sheet-shaped body is in the form of a knitted fabric or the like, it can be appropriately selected from the above materials and is not particularly limited as long as the effects of the present invention are not impaired, but at least one side of the resulting knitted fabric (laminated with a nanofiber nonwoven fabric) It is desirable to combine the same material with the nanofiber nonwoven fabric or a material that can be dissolved in the same solvent with the nanofiber nonwoven fabric. Examples of such a combination of materials include cotton / polyurethane, cotton / urethane elastomer, and cupra / polyurethane.

  When the sheet-shaped body is knitted, there are no particular restrictions on the type of tissue (type of knitting method), fiber length (filament (long fiber), staple (short fiber)), etc., but the same material as the nanofiber nonwoven fabric Alternatively, it is desirable that a material that can be dissolved in the same solvent as the material of the nanofiber nonwoven fabric is displayed on the uppermost surface of the surface on which the nanofiber nonwoven fabric is laminated.

  Examples of the knitted fabric that can be employed in the present invention include flat knitted fabrics composed of flat knitting and circular knitting, rubber knitted fabrics, double-sided knitted fabrics, and the like, and can be knitted into various organizations according to conventionally known methods. it can. For example, using a circular knitting machine suitable for a knitted structure, the yarn length and loop length, yarn feeding tension, fabric tension, etc. can be set and knitted within the range of 16 to 40 G gauge.

  When the sheet-shaped body is a knitted fabric, for example, the surface yarn is made of cotton yarn and the back yarn is made of polyurethane bear yarn, so that the polyurethane bare yarn is exposed on one side of the resulting knitted fabric, and the polyurethane nano yarn is formed thereon. A fiber nonwoven fabric can be laminated.

  At this time, it is desirable that the surface on which the polyurethane nanofiber nonwoven fabric is laminated has as much polyurethane bare yarn as possible. Thereby, the laminated nanofiber nonwoven fabric is easily welded to the knitted fabric by the residual solvent. Therefore, on at least one side of the knitted fabric, the polyurethane bear yarn is preferably 45% or more in terms of surface ratio, more preferably 50% or more, further preferably 55% or more, and particularly preferably 70% or more. Yes. It is desirable to appropriately set the manufacturing conditions of the knitted fabric so that the surface ratio is such. The upper limit of the surface ratio is not particularly limited, but is preferably 90% or less, and more preferably 80% or less.

  Here, the surface ratio can be calculated as follows.

  Using a video microscope, take a loop on the back of the fabric at a magnification of 100-300. At this time, no special tension is applied to the fabric, and the stress is relaxed. From the photographed image, the total of the area of the polyurethane bear yarn appearing on the surface and the area of the surface yarn can be obtained, and the surface ratio can be obtained by the following formula.

  Production conditions that affect the surface ratio include yarn feeding tension, fineness, surface yarn processing state, fineness balance between front yarn and back yarn, yarn length, and the like. In order to satisfy the surface ratio, the yarn feeding tension of the back yarn (polyurethane bear yarn) is preferably 0.2 to 1.5 cN, and more preferably 0.2 to 0.5 cN. When the sheet-shaped body is a knitted fabric, the fineness of the back yarn (polyurethane bear yarn) is preferably 33 dtex or more, more preferably 44 to 222 dtex, still more preferably 44 to 111 dtex, and particularly preferably 50 to 111 dtex. If it is such a range, the knitted fabric of the said surface rate can be obtained, and the intensity | strength of the composite fabric of this invention can also be maintained.

  Moreover, in order to expose the polyurethane bear yarn at the surface ratio on the surface on which the nanofiber nonwoven fabric is laminated, it is preferable to use raw yarn rather than wooly yarn or spun yarn as the surface yarn. Furthermore, regarding the balance between the fineness of the front yarn and the back yarn, it is desirable that the fineness of the back yarn does not become 20% or less with respect to the fineness of the front yarn. As for the yarn length, if the back yarn is too short with respect to the front yarn, it is difficult to be exposed on the fabric. Therefore, the back yarn is desirably 50% or more of the front yarn. Here, the case where cotton yarn is used for the front yarn and polyurethane bear yarn is used for the back yarn has been described as an example. However, even when polyurethane bear yarn is used for the front yarn and cotton yarn is used for the back yarn, the surface ratio is adjusted under the same conditions. be able to. In addition, even if the front yarn and the back yarn are materials other than cotton yarn and polyurethane bear yarn, respectively, referring to the above, the same material as the nanofiber nonwoven fabric or the same solvent as the nanofiber nonwoven material is used. The surface ratio of the material that can be dissolved can be adjusted.

  Even when a woven fabric is used as the sheet-shaped body of the present invention, a material used for the knitted fabric can be selected. Examples of the fabric structure include plain weaves, twill weaves, and weaves, and can be knitted into various structures according to conventionally known methods. Even when a woven fabric is used as the sheet-shaped body, the same material as the nanofiber nonwoven fabric, or a material that can be dissolved in the same solvent as the nanofiber nonwoven material on the surface on which the nanofiber nonwoven fabric is laminated is the same as the above knitted fabric. It is desirable to have a surface ratio.

  When using a nonwoven fabric as the sheet-shaped body of the present invention, the material can be appropriately selected from conventionally known materials, and is not particularly limited. For example, it is composed of polyurethane, aramid, cellulose, nylon, polyester, polyolefin, rayon, etc. These fibers can be used, and these materials can be used alone or in combination of two or more.

  By using such a material, a nonwoven fabric can be obtained according to a conventionally known production method such as a thermal bond method, a chemical bond method, a needle punch method, a spunlace method (a hydroentanglement method), a stitch bond method, or a steam jet method. . However, at least the surface on which the nanofiber nonwoven fabric is laminated is preferably composed of the same material as that of the nanofiber nonwoven fabric, or a material that can be dissolved in the same solvent as the material of the nanofiber nonwoven fabric. It is desirable to have a surface ratio.

  In addition, as a combination of materials when using a material that can be dissolved in the same solvent as the material of the nanofiber nonwoven fabric as a material of the sheet shape body, for example, on a sheet shape body constituted by nylon 6 or polyamide elastomer The nanofiber nonwoven fabric can be laminated using a solution of polyurethane dissolved in hexafluoroisopropanol (HFIP).

  In the present invention, any of the above-mentioned knitted fabric, woven fabric and non-woven fabric may be adopted as the sheet-shaped body, but a knitted fabric is preferred particularly when the composite fabric of the present invention is used for clothing. In the composite fabric of the present invention, the total thickness of the sheet-shaped body is usually 100 to 500 μm, preferably 140 to 400 μm.

(2) Nanofiber non-woven fabric In the composite fabric of the present invention, the nanofiber non-woven fabric has a function of exerting an excellent heat retaining effect while preventing moisture from entering the clothes while preventing moisture from entering.

  The diameter of the nanofiber which comprises the nanofiber nonwoven fabric used in this invention is 50 nm or more and less than 1.5 micrometers, Preferably it is 20-900 nm, More preferably, it is 50-700 nm, More preferably, it is 100-500 nm. Here, the diameter of the nanofiber was photographed with a scanning electron microscope (SEM) at a magnification of 10,000 to 50,000 times, and the thickness of the randomly selected fiber (the length in the direction perpendicular to the fiber axis) was measured at 30 points. And is represented by the average value.

  The nanofiber material is not particularly limited as long as the material has an elongation enough to follow the stretchability of the sheet-shaped body, and a conventionally known material can be used. Moreover, it can be selected from the synthetic fibers and thermoplastic elastomer fibers exemplified as the material for the sheet-shaped body in the above (1), polyurethane (for example, spandex, etc.), elastomer-based polymer (for example, urethane-based elastomer) , Thermoplastic elastomer fibers such as polyester-based elastomers and polyamide-based elastomers) and the like, preferably polyurethane and urethane-based elastomers. Such nanofibers made of a polymer material are excellent in stretchability, and are therefore suitable when the composite fabric of the present invention is used as a material for underwear.

  The nanofiber nonwoven fabric used in the present invention is directly laminated on at least one surface of a sheet-shaped body by an electrospinning method (ESD). Regarding the method of laminating the nanofiber nonwoven fabric, the following 2. The details are described in the column.

The nanofiber nonwoven fabric used for the composite fabric of the present invention preferably has an apparent density of less than 1 g / cm ³ , more preferably 0.01 to 0.5 g / cm ³ , still more preferably 0.01 to 0.1 g / cm ^{3. 3} . The apparent density is a value obtained by measuring the thickness and weight of a 20 cm × 20 cm sample and calculating the weight per unit volume. The nanofiber nonwoven fabric having such an apparent density has many immobile air layers. The immovable air layer is a very minute layer of air in the nonwoven fabric, and since heat convection does not occur as moisture moves, high heat retention can be realized.

  The total thickness of the nanofiber nonwoven fabric used in the present invention is usually 10 to 300 μm, preferably 50 to 200 μm.

(3) Other Embodiments As another preferred embodiment of the nonwoven fabric of the present invention, a form in which nanofiber nonwoven fabrics are laminated on both surfaces of a sheet-shaped body may be included. That is, for example, a form in which a large amount of polyurethane is exposed on one side of the sheet-shaped body and a polyurethane nanofiber nonwoven fabric is laminated, and a large amount of nylon is exposed on the other surface to laminate a nylon nanofiber nonwoven fabric.

  Moreover, the form which laminated | stacked the sheet-shaped body further on the nanofiber nonwoven fabric laminated | stacked on the sheet-shaped body may be sufficient as the composite fabric of this invention. At this time, the two sheet-shaped bodies may be the same or different from each other. The method for further laminating the sheet-shaped body on the laminated nanofiber nonwoven fabric is not particularly limited, but for example, both can be sewn and laminated together like a quilt material. By further laminating and sewing the sheet-shaped body, the composite fabric of the present invention can be reinforced, and sufficient practical strength is imparted. In addition, by sandwiching the nanofiber nonwoven fabric between the sheet-shaped bodies, the nanofiber nonwoven fabric can be prevented from being peeled off, and the practicality is enhanced in terms of durability.

  (4) The composite fabric of the present invention preferably has the following physical properties.

(Ventilation resistance)
In the KES ventilation resistance test (KES-F8-AP1 permeability tester manufactured by Kato Tech Co., Ltd.), it is 0.2 kPa · s / m or more, preferably 0.2 to 10 kPa · s / m. This is considered to be because the air permeability is blocked because the hole diameter is very fine, and thus the windproof property is maintained.

The windproof property can be expressed not only by the above-described ventilation resistance value but also by the amount of ventilation per unit time. For example, in the air flow test by the Frazier method (JIS L 1096), the air flow is 60 cm ³ / cm ² / sec or less, preferably 50 cm ³ / cm ² / sec or less. In addition, the measured value of said KES ventilation resistance test has a correlation with the ventilation amount value by a Frazier method (JIS L1096).

(Breathable)
Composite fabric of the present invention, moisture permeation amount 3000g / 24h · ^{m 2} or more according to JIS L 1099 A-2 method, preferably 4000g / 24h · ^{m 2} or more, more preferably 4200g / 24h · ^{m 2} or more. A moisture permeability of 3000 g / 24 h · m ² or more is preferred because it does not feel uncomfortable due to stuffiness in clothing.

  The composite fabric of the present invention preferably satisfies both the above-mentioned ventilation resistance and moisture permeability.

(Peel strength)
The composite fabric of the present invention has a peel strength of 20 cN to 30 cN according to JIS L 1089 method. By having such a peel strength, the nanofiber nonwoven fabric is hardly peeled off from the sheet-shaped body, and can be used for a long time.

(Flexibility)
The composite fabric of the present invention has a bending resistance of 4 cN to 10 cN. The bending resistance can be measured according to the method (G method) described in the column of Examples below. Since the composite fabric having such a bending resistance is soft, it can be suitably used for clothes and the like.

  When the composite fabric of the present invention is in a form in which a nanofiber nonwoven fabric is laminated on a sheet-shaped body, the glove (for clean room, using the non-slip and water repellency with the nanofiber nonwoven fabric surface outside is used. It can be used as a fabric such as a motorcycle glove.

  Further, the composite fabric of the present invention can be suitably used as a material for clothes, particularly innerwear (preferably underwear for cold protection, underwear for heat retention, etc.), sportswear and the like. Examples of such underwear include shirts, briefs, stomach wraps, stetecos, patches, shorts, girdles, petticoats, leggings, socks, tights, and the like. Examples of sportswear include use of wear worn when performing competitions such as motorcycles, bicycle road races, fishing, yacht sailing, and golf. When manufacturing clothes etc. using the composite fabric of this invention, what is necessary is just to follow a conventionally well-known method, and a cutting method, a sewing method, etc. are not specifically limited. When the composite fabric of the present invention is used as a material for clothes, the sheet-shaped body is further laminated on the nanofiber nonwoven fabric laminated on the sheet-shaped body described in the above (3) other embodiments. By adopting the form, clothes suitable for practical use can be obtained.

2. Manufacturing Method The present invention also provides a method for manufacturing the above-mentioned double post-fabric. That is, the present invention relates to a nanofiber nonwoven fabric composed of ultrafine fibers having a diameter in the direction perpendicular to the fiber axis of 50 nm or more and less than 1.5 μm by directly performing electrospinning on at least one side of the sheet-shaped body. A method for manufacturing a composite fabric comprising the step of laminating on top is provided.

  In the method for producing a composite fabric of the present invention, the material constituting the nanofiber nonwoven fabric is dissolved in a solvent, and this solution is directly sprayed onto the sheet-shaped body by electrospinning to generate, laminate and bond at a time. It is characterized by. Hereinafter, a case where a knitted fabric composed of polyurethane yarn and cotton yarn is formed into a sheet-shaped body and a polyurethane nanofiber nonwoven fabric is laminated will be described as an example.

  The surface of the knitted fabric where a large amount of polyurethane yarn appears is placed on the collector with the nozzle side, and a polyurethane nanofiber nonwoven fabric is produced and laminated thereon by electrospinning. Here, it is preferable that the polyurethane polymer used for producing the nanofiber nonwoven fabric and the polyurethane yarn used for the knitted fabric can be dissolved in the same solvent. Examples of the solvent include N, N-dimethylformamide, tetrahydrofuran, dimethylacetamide, hexafluoroisopropanol, and the like, preferably N, N-dimethylformamide.

  Typical examples of producing a nanofiber nonwoven fabric by the electrospinning method include a voltage of -70 to 70 kV, a nozzle diameter of 14 to 32 G, and a distance of 5 to 30 cm from the nozzle tip to the collector. Moreover, although it changes suitably according to the polymer raw material to be used, for example, in the case of a polyurethane resin, it is used by dissolving in the solvent at a concentration of 3 to 40% by weight, preferably 5 to 30% by weight.

  In addition, it is preferable to laminate the nanofiber nonwoven fabric without completely evaporating the solvent of the nanofiber nonwoven fabric. The residual solvent remaining in the nanofiber dissolves the polyurethane yarn on the knitted fabric, and the nanofiber and the polyurethane yarn can be welded. The residual solvent can be adjusted by adjusting the solution concentration, the applied voltage, the nozzle diameter, and the distance from the nozzle tip to the collector in the production environment.

  Moreover, the residual degree of a solvent can be confirmed by observing the state of the nanofiber nonwoven fabric produced | generated by SEM. A representative example of an electron micrograph is shown in FIG. As shown in FIG. 1A, when a large amount of residual solvent remains, it can be confirmed that the fibers are welded at the time of lamination. On the other hand, as shown in FIG. 1B, it can be confirmed that the fibers are not welded when the residual solvent is not so much left. In the present invention, the state as shown in FIG. 1A is preferable, and it is desirable to adjust the electrospinning conditions so that the state as shown in FIG. .

  When the nanofiber nonwoven fabric is laminated on the sheet-shaped body using other materials, a conventionally known solvent suitable for various resins can be used, and the dissolution concentration can be appropriately set with reference to the above concentration. . At this time, as a solvent for dissolving the material of the nanofiber nonwoven fabric, it is desirable to use a solvent capable of dissolving the material constituting the surface on which the nanofiber nonwoven fabric of the sheet-shaped body is laminated.

  When the nanofiber nonwoven fabric is produced by the electrospinning method, the molecular weight of the resin as a raw material is, for example, 70,000 or more, preferably 100,000 or more, for example, about 70,000 to 500,000, preferably about 100,000 to 500,000. The resin is preferably completely dissolved in the solvent.

  According to such a method of the present invention, it is possible to simultaneously produce, laminate, and bond the nanofiber nonwoven fabric and reduce the number of steps.

  EXAMPLES Hereinafter, although an Example is shown and this invention is demonstrated in detail, this invention is not limited to these.

[Example 1]
The surface yarn was cotton yarn (96th) and the back yarn was polyurethane knitted yarn (Mobilon 78T: manufactured by Nisshinbo Industries, Ltd .; fineness 78 dtex) to produce a bare sheet material. The yarn feeding tension of the yarn feeding device (KTF) used for producing the knitted fabric was polyurethane fiber 0.5 cN.

  Electrospinning was performed on one side of the bare sheet material by the following method, and a nanofiber nonwoven fabric made of a thermoplastic polyurethane resin was laminated and welded.

  A thermoplastic polyurethane resin (urethane-based elastomer: product name Pandex1185: manufactured by DIC Bayer Ltd.) is dissolved in 23% by weight in DMF (N, N-dimethylformamide), and this is filled in the solution filling portion of the electrospinning apparatus. Then, electrospinning was performed by applying a voltage of 55 kV. The diameter of the metal nozzle used at this time was 21 G (inner diameter: 0.51 mm), and the distance to the collector was 15 cm.

[Example 2]
A composite fabric was produced in the same manner as in Example 1 except that the front yarn was polypropylene fiber (PP56T: manufactured by Mitsubishi Rayon Co., Ltd.).

[Example 3]
A composite fabric was prepared in the same manner as in Example 1 except that the front yarn was polypropylene fiber (PP56T: manufactured by Mitsubishi Rayon Co., Ltd.) and the back yarn was polyurethane bear yarn (Mobilon 78T: manufactured by Nisshinbo Co., Ltd .; fineness 110 dtex). .

[Comparative Example 1]
A composite fabric was produced in the same manner as in Example 1 except that the yarn feeding tension of the yarn feeding device (KTF) was polyurethane fiber 6cN.

[Comparative Example 2]
A composite fabric was produced in the same manner as in Example 1 except that the back yarn was a polyurethane fiber having a fineness different from that in Example 1 (Mobilon 33T: manufactured by Nisshinbo Industries, Ltd .; fineness 33 dtex).

[Comparative Example 3]
A nanofiber nonwoven fabric is electrospun in the same manner as in Example 1 for a common bare sheet material, with the front yarn being cotton yarn (60th) and the back yarn being Mobilon 44T (Nisshinbo Co., Ltd .: Fineness 44 dtex). And laminated.

[Comparative Example 4]
A nanofiber nonwoven fabric was separately prepared according to the method of Example 1 without being laminated on the knitted fabric. A mesh-type urethane heat-sealing film (FUUSEC C6J5 manufactured by Tokai Thermo Co., Ltd.) is inserted between the obtained nanofiber nonwoven fabric and the knitted fabric, and pressure bonded at 115 ° C. under a pressure of 2 MPa to form a composite fabric Got.

[Comparative Example 5]
A knitted fabric was produced in the same manner as in Example 1 (the nanofiber nonwoven fabric was not laminated).

  The composite fabric obtained as described above was evaluated according to the following evaluation method.

[Evaluation methods]
<Nanofiber fiber diameter>
The fiber diameter of the nanofiber was photographed with a scanning electron microscope (SEM) at a magnification of 10,000 to 50,000 times, and the thickness of the randomly selected fiber (length in the direction perpendicular to the fiber axis) was measured at 30 points. The average value was obtained. All of the fibers of Examples 1 and 2 and Comparative Examples 1 to 3 were within an average range of 432.5 nm ± 10%.

<Surface ratio>
A loop on the back of the fabric was photographed at a magnification of 100 to 300 using a video microscope. At this time, the fabric is in a free state, that is, no special tension is applied to the fabric, and the image is taken with the stress relaxed. From the photographed image, the total of the area of the polyurethane bear yarn appearing on the surface and the area of the surface yarn was determined, and the surface ratio was determined by the following formula.

<Dough thickness>
Using a micro gauge, three locations were measured for each fabric, and the average value was taken as the thickness.

<Moisture permeability>
JIS L 1099 was evaluated according to Method A-2 ^{(Unit: cm 3 / 24h · m 2} ).

<Ventilation resistance>
It was measured using a KES air permeability tester (KES-F8-AP1 manufactured by Kato Tech Co., Ltd.) (unit: kPa · sec / m). Ventilation resistance value is within 10 seconds per cycle by KES-F8-AP1 air permeability tester by sending air to the sample at range L and piston speed 2cm / sec, and releasing and sucking it through the sample into the atmosphere. Is measured using a semiconductor differential pressure gauge.

<Peel strength>
Evaluation was made according to JIS L 1089 (unit: cN).
The composite fabric knitted fabric of size 2.5 x 9 cm and the nanofiber nonwoven fabric were peeled about 3 cm in advance, and the peel strength when peeled at a gripping distance of 2 cm and a test speed of 100 mm / min is the MAX point (from the larger) 5 Measurements were made at five locations and five MIN points (from the smallest), and the average value was determined.

<Bending softness>
Evaluation was made according to the slit method (G method) (unit: cN). The test conditions are as follows. A surface on which a nanofiber nonwoven fabric of a test sample having a size of 7 cm × 7 cm is laminated is placed on the slit plate, and the slit groove direction is aligned in the course direction (lateral direction of the knitted fabric) from the slit width of 5 mm. The maximum resistance stress when pressed by a slit bar (speed 100 mm / min) was measured by an autograph so as to be perpendicular to the loop row (room temperature 20 ° C .; humidity 65%). A schematic diagram of the measurement is shown in FIG.

  The evaluation results for each sample are shown in Table 1.

  From Table 1, the composite fabric of Example 1 and 2 showed the value equivalent to the moisture permeability of the comparative example 5 which did not laminate | stack a nanofiber nonwoven fabric, and it was shown that it is excellent in moisture permeability. Further, the air resistance was also good, indicating that the wind resistance was excellent. Further, the bending resistance showed a good value. Thus, it was shown that the composite fabric of the present invention is thin and soft and excellent in windproof property and heat retaining property.

  On the other hand, in Comparative Example 1, since the surface ratio of the polyurethane yarn is low, the adhesion of the nanofiber nonwoven fabric is not sufficient, and the bending resistance is higher than in Examples 1 and 2 (the fabric is hard). became. Also in Comparative Example 2 and Comparative Example 3 (conventional knitted fabric), the adhesiveness of the nanofiber nonwoven fabric was not sufficient because the surface ratio of the polyurethane yarn was low. In Comparative Example 4, the adhesion between the nanofiber nonwoven fabric and the knitted fabric was sufficient because an adhesive layer was used, but the bending resistance was inferior. Furthermore, in Comparative Example 5 in which the nanofiber nonwoven fabric was not laminated, the value of the airflow resistance was low, indicating that the windproof property and the heat retaining property were inferior.

[Test Example 1]
For the composite fabrics obtained in Examples 1 and 2 and Comparative Examples 4 and 5, the underwear was sewn and evaluated for heat retention, stuffiness, touch, and lightness (subject: age 20-30s; male 3 3 females). The evaluation method is as follows.

Thermal insulation: In a room with an air temperature of 25 ° C., cold air of 10 ° C. was flowed from a hose with a diameter of 20 cm from a position 20 cm away, and how it was felt was evaluated according to the following indices.
○: warm △: slightly cold ×: cold

Feeling of stuffiness: The feeling of stuffiness in clothes after performing 30 steps of step-up / down step up / down motion was evaluated by the following index.
○: No stuffiness △: Some stuffiness x: stuffiness

Touch: The following indicators evaluated how the skin feels when worn or handled by hand.
○: Soft △: Normal ×: Hard

Lightness: How the weight feeling when worn or handled by hand was evaluated by the following index.
○: Light △: Normal ×: Heavy

  From Table 2, the composite fabric of the present invention gave good results in any evaluation of heat retention, feeling of stuffiness, touch and lightness. On the other hand, the composite fabric of Comparative Example 4 in which the nanofiber nonwoven fabric and the knitted fabric were bonded by a heat-sealing film had no problem in heat retention and stuffiness, but was more than in Examples 1 and 2 in terms of touch and lightness. Inferior results were shown. Furthermore, it was shown that the fabric of Comparative Example 5 in which the nanofiber nonwoven fabric was not laminated had good stuffiness, touch and lightness, but sufficient heat retention could not be obtained.

Claims (7)

A composite fabric obtained by directly laminating a nanofiber nonwoven fabric composed of ultrafine fibers having a diameter in a direction perpendicular to the fiber axis of 50 nm or more and less than 1.5 μm on at least one surface of a sheet-shaped body. The composite fabric according to claim 1, wherein the sheet-shaped body is a woven fabric, a knitted fabric, or a nonwoven fabric. The composite fabric according to claim 1 or 2, wherein the component constituting the nanofiber nonwoven fabric is a urethane elastomer. The composite fabric according to claim 3, wherein the same component as that constituting the nanofiber nonwoven fabric is exposed at a surface ratio of 45% or more on the surface on which the nanofiber nonwoven fabric of the sheet shape is laminated. Claim airflow resistance by KES-F8-AP1 is at 0.2 KPa · s / m or more and moisture permeability, characterized in that at 3000cm ³ / 24h · ^{m 2} or more in JIS L 1099 A-2 Method 1 The composite fabric in any one of -4. The composite fabric according to any one of claims 1 to 5, which is in the form of a glove or an inner wear. A step of directly performing electrospinning on at least one surface of the sheet-shaped body, and laminating a nanofiber nonwoven fabric made of ultrafine fibers having a diameter in the direction perpendicular to the fiber axis of 50 nm or more and less than 1.5 μm on the sheet-shaped body. A method for producing a composite fabric comprising:

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