JP5643633B2 - Non-woven - Google Patents

Description

  The present invention relates to a nonwoven fabric having a multilayer structure having elasticity.

  As a conventional technique related to a nonwoven fabric having elasticity using elastic fibers, for example, a technique described in Patent Document 1 is known. The nonwoven fabric described in this document is formed by laminating a spunbond nonwoven fabric made of inelastic fibers on each surface of a meltblown nonwoven fabric or a spunbond nonwoven fabric made of elastic fibers. In order to impart stretchability to the nonwoven fabric, it is necessary to subject the inelastic fiber to plastic deformation by performing a stretching treatment. However, if it is attempted to increase the stretchability by increasing the degree of stretching, the inelastic fibers exceed the limit of plastic deformation, and the nonwoven fabric is torn. It is conceivable to use a blend of polypropylene resin and polyethylene resin to the inelastic fiber or to use an ethylene-propylene copolymer as a raw material for the inelastic fiber so that the inelastic fiber is easily plastically deformed. In that case, it becomes economically disadvantageous. In addition, smooth spinning of the fiber may be hindered.

  Patent Document 2 includes a first polymer component and a second polymer component, in which the first component has greater elasticity than the second component, and the first and second components are A bonded web is arranged in a substantially distinct area extending longitudinally along the length of at least a portion of the strand, the second web comprising an area that forms at least a portion of the peripheral surface of the strand. Have been described. In this web, since the first polymer component and the second polymer component are in close contact with each other in the strand constituting the web, the stretchability of the highly elastic polymer component is likely to be hindered by the less elastic polymer component. Therefore, the inherent stretchability of the highly elastic polymer component is not sufficiently exhibited. In order to make the stretchability of the polymer component having high elasticity remarkable, the proportion of the polymer component having high elasticity in the strand should be relatively high, and the proportion of the polymer component having low elasticity should be relatively low. Can be considered. However, since this web is maintained in the form of a web by fusing polymer components having low elasticity, reducing the ratio of the polymer component having low elasticity leads to a decrease in the strength of the web.

  Patent Document 3 describes a composite elastic nonwoven fabric obtained by laminating an elastomer spunbond web on each surface of an elastomer meltblown web. However, since this nonwoven fabric is in a state where the elastic resin is exposed on the surface thereof, the nonwoven fabric exhibits an unpleasant sticky feeling peculiar to the elastic resin. Therefore, when the nonwoven fabric is wound and stored, for example, blocking between adjacent nonwoven fabrics is likely to occur, and the feeding is likely to be hindered.

JP 62-84143 A JP 2002-522653 A Japanese National Patent Publication No. 9-500936

  Therefore, the subject of this invention is providing the nonwoven fabric which has a stretching property which can eliminate the fault which the prior art mentioned above has.

The present invention is a nonwoven fabric in which the second elastic fiber is disposed on one surface of the elastic fiber layer including the first elastic fiber, and is stretchable in at least one direction,
The first elastic fiber includes a first resin component made of an elastic resin and a second resin component made of an inelastic resin, and the second resin component exists at least part of the fiber surface continuously in the length direction. And a nonwoven fabric in which the ratio of the second resin component in the first elastic fiber is 70 to 96% by mass.

  According to the present invention, there is provided a nonwoven fabric having high stretchability, good texture, and prevention of delamination between layers.

  Hereinafter, the present invention will be described based on preferred embodiments thereof. The nonwoven fabric of the present invention has a multilayer structure. The nonwoven fabric of the present invention having a multilayer structure has a first elastic fiber layer containing first elastic fibers. A second elastic fiber, which is an elastic fiber different from the first elastic fiber, is disposed on one surface of the first elastic fiber layer. The first elastic fiber layer imparts a good texture to the nonwoven fabric of the present invention and imparts a certain degree of stretchability. On the other hand, the second elastic fiber disposed on one surface of the first elastic fiber layer mainly has good stretchability in the nonwoven fabric of the present invention.

  The nonwoven fabric of the present invention has, for example, (i) a structure in which the second elastic fiber is disposed on one surface of the first elastic fiber layer including the first elastic fiber, or (ii) two first elastic fiber layers. The second elastic fiber is arranged between the two. When the nonwoven fabric of this invention has the structure of (i), it is preferable to use the surface where the 1st elastic fiber layer exists as an outer surface (exposed surface) of this nonwoven fabric. When it has the structure of (ii), it is preferable to use any one of two 1st elastic fiber layers as an outer surface (exposed surface) of this nonwoven fabric. When the structure of (ii) is adopted among the structures of (i) and (ii), there is an appropriate thickness feeling even if the basis weight of the nonwoven fabric is low due to the tooth-shaped drawing process described later. It is preferable because a nonwoven fabric having a good texture is obtained, and blocking is effectively prevented when the nonwoven fabric is rolled up. The two first elastic fiber layers are made of a fiber material, and any of the first elastic fiber layers includes the first elastic fibers. If the first elastic fiber is included, the two first elastic fiber layers may have the same fiber composition or different fiber compositions. As the first elastic fiber contained in these first elastic fiber layers, a composite fiber containing a first resin component and a second resin component is used.

  The first resin component constituting the first elastic fiber is made of an elastic resin, and the elastic resin is a component that imparts elasticity to the first elastic fiber. On the other hand, the second resin component is made of a non-elastic resin, and the non-elastic resin imparts a good texture to the first elastic fiber and enhances the bonding property (fusion property) between the constituent fibers of the nonwoven fabric of the present invention, It is a component for preventing delamination between layers and increasing the strength of the nonwoven fabric of the present invention as a whole.

  The first resin component in the first elastic fiber extends continuously in the length direction of the first elastic fiber. On the other hand, the second resin component is present continuously in the length direction on at least a part of the fiber surface of the first elastic fiber. Examples of the fiber form of the first elastic fiber include a core-sheath type composite fiber having a first resin component as a core and a second resin component as a sheath, and a first resin component and a second resin component in the cross section of the fiber. And side-by-side type composite fibers that are parallel to each other. The core-sheath type composite fiber includes those crimped by stretching due to the eccentricity of the core. However, it is preferable to use a concentric core-sheath composite fiber rather than an eccentric core-sheath composite fiber. The reason for this is that the concentric core-sheath composite fiber is less likely to be partially broken by the inelastic resin as the second resin component during stretching than the eccentric core-sheath composite fiber, and as a result, the first resin component This is because the elastic component is difficult to be exposed on the fiber surface, and a non-woven fabric excellent in touch is easily obtained.

  The nonwoven fabric of this invention has one of the characteristics in the ratio of the 1st resin component and 2nd resin component in a 1st elastic fiber. Specifically, in the first elastic fiber, the ratio of the second resin component is set to 70 to 96 mass%, preferably 80 to 90 mass%. On the other hand, the ratio of the first resin component is set to 4 to 30% by mass, preferably 10 to 20% by mass. In short, in the first elastic fiber, the ratio of the second resin component is relatively higher than the ratio of the first resin component. Accordingly, in the first elastic fiber, the ratio of the first resin component exposed on the fiber surface is low, and the second resin component is mainly exposed on the fiber surface. Advantages of using the first elastic fiber having such characteristics are, for example, as described in the following (a) to (d).

(A) In a fiber made of a normal inelastic resin, a fiber necking phenomenon occurs at the time of drawing, and stress concentrates on the necking portion, so that the fiber is easily broken. However, the non-elastic resin that is the second resin component of the first elastic fiber is mainly exposed on the surface, for example, the first elastic fiber has a core-sheath structure, so that the sheath is easily stretched. Following this, the fiber can be stretched to a high magnification without breaking. Thereby, a non-woven fabric with high strength is obtained after stretching.
(B) As described above, the second resin component is an inelastic resin. The non-elastic resin is less sticky than the elastic resin and exhibits a good texture. Also, when the raw fabric is obtained by winding after forming the nonwoven fabric, the elastic resin is exposed on both sides of the nonwoven fabric because the second resin component, which is an inelastic resin, is mainly exposed on the fiber surface. Compared with the case where it is carrying out, it becomes difficult to block at least one side. As a result, when the material is fed out after being stored, a product that does not interfere with the feeding is obtained.
(C) The non-elastic resin that is the sheath is stretched by stretching, and then the first elastic fiber is slightly contracted by the elastic resin that is the core, so that fine wrinkles are formed on the fiber surface. As a result, the first elastic fiber has a good touch.
(D) When the nonwoven fabric is stretched by a concavo-convex roll, which will be described later, small ridges and small ridges extending in a streak-like manner in a direction intersecting with the stretch direction of the nonwoven fabric are alternately formed on the surface of the nonwoven fabric. Is done. The first elastic fiber layer extends once when stretched, but then contracts to a certain extent. Therefore, when the elastic fiber is used for the first elastic fiber layer, it is excessive compared to the case where the non-elastic fiber is used for the first elastic fiber layer. The fiber is prevented from floating and becomes minute in the thickness direction, resulting in a regular and minute gather structure. Thereby, the external appearance of a nonwoven fabric looks like a stretchable cloth and becomes favorable. Here, if the ratio of the second resin component, which is an inelastic resin in the first elastic fiber, is less than 70% by mass, the fiber returns to the original length after the stretching, so that a minute gather structure is formed. Difficult and uncomfortable. Further, in order to obtain such a fine gather structure, the residual strain of the first elastic fiber layer is preferably 25 to 90%, more preferably 40 to 70%, and the portion where the second elastic fiber is disposed. The residual strain is preferably 25% or less, more preferably 3 to 13%.

  The first elastic fiber having the advantages as described above exhibits a good texture while exhibiting elasticity. And when the 1st elastic fiber which has such a property is contained in the layer which makes the outermost surface in the nonwoven fabric of this invention, the nonwoven fabric of this invention becomes a thing with a further favorable texture.

  In addition, the first elastic fiber is flexible because the fiber itself is soft when compared to a fiber of the same thickness made of 100% non-elastic fiber (because the rigidity is low), Also by this, the nonwoven fabric of the present invention has a good texture.

  Furthermore, when the first elastic fiber is a core-sheath type composite fiber, light is easily diffusely reflected at the interface between the core component and the sheath component due to the difference in refractive index between the core component and the sheath component. Further, as described above, fine wrinkles are formed on the fiber surface after stretching, and light is likely to be irregularly reflected on the fiber surface. As a result, the non-woven fabric of the present invention has high concealability. The high concealability of the nonwoven fabric is advantageous in that when the nonwoven fabric is used as a constituent member of an absorbent article such as a disposable diaper or a sanitary napkin, it is difficult to visually recognize the absorbed body fluid from the outside.

  In addition, the inelastic resin as the second resin component is also a bonding component (fusion component) in the nonwoven fabric of the present invention. Therefore, because the ratio of the second resin component in the first elastic fiber is high, the fibers constituting the nonwoven fabric of the present invention are reliably bonded to each other by the bonding component made of inelastic resin. Yes. As a result, the non-woven fabric of the present invention is effectively prevented from being separated from each other and has an increased strength.

  Constructing the first elastic fiber from a composite fiber of an elastic resin and a non-elastic resin is advantageous from the viewpoint of increasing the light resistance of the first elastic fiber. The reason for this is as follows. It is known that elastic fibers generally have lower light resistance than non-elastic fibers. Therefore, when the first elastic fiber is made of 100% elastic resin, such a fiber is inferior in light resistance. On the other hand, by configuring the first elastic fiber from a composite fiber of an elastic resin and a non-elastic resin, compared to a case where the first elastic fiber is composed of 100% elastic resin by the amount of the non-elastic fiber, The light resistance of one elastic fiber can be relatively enhanced.

  The above-described various advantages arise by making the ratio of the non-elastic resin that is the second resin component in the first elastic fiber higher than the ratio of the elastic resin that is the first resin component. Increasing the proportion of inelastic resin has a negative effect. Therefore, in the nonwoven fabric of the present invention, the second elastic fiber is disposed on one surface of the first elastic fiber layer, and the second elastic fiber imparts high stretchability to the entire nonwoven fabric. From this viewpoint, the second elastic fiber is preferably composed of 100% elastic resin. As described above, the elastic resin has a sticky feeling peculiar to the elastic resin. However, if the first elastic fiber layer is used as a use surface (for example, when the elastic resin is disposed between the two first elastic fiber layers). Since the second elastic fiber is difficult to be exposed on the surface of the nonwoven fabric, even if the second elastic fiber is composed of 100% elastic resin, the texture of the nonwoven fabric of the present invention is not adversely affected.

  In addition, as described above, a fiber generally composed of 100% elastic resin is inferior in light resistance. However, even if the second elastic fiber is made of 100% elastic resin, the second elastic fiber is not directly exposed to light if the second elastic fiber is not used and the first elastic fiber layer is used. Therefore, the risk of deterioration of the second elastic fiber due to low light resistance is low.

  As described above, the second elastic fiber is preferably composed of 100% elastic resin, but the second elastic fiber may contain inelastic resin in addition to elastic resin. Since the second elastic fiber contains an inelastic resin, the proportion of the binding component as a whole of the nonwoven fabric is increased, peeling between layers is prevented, the strength of the nonwoven fabric is improved, and blocking when the nonwoven fabric is used as a scroll is prevented. There is an advantage that you can. When the second elastic fiber includes an inelastic resin, the second elastic fiber is a single fiber obtained by blending and melt-mixing the elastic resin and the inelastic resin, so that the ratio of reducing the stretch property is small. preferable. The melt mixing may be in a uniform solution state or a sea-island-incompatible state, but is preferably in a uniform solution state from the viewpoint that blocking can be further prevented. By using resins having good compatibility, it becomes possible to achieve a uniform dissolution state. The dissolved and mixed state can be confirmed by observing the second elastic fiber using a transmission electron microscope (TEM) or a scanning electron microscope (SEM). Further, the second elastic fiber includes an elastic resin and a non-elastic resin, and the non-elastic resin is made of a composite fiber in which at least a part of the fiber surface of the second elastic fiber is continuously present in the length direction. Is preferable in that it is difficult to cause yarn breakage during fiber molding. Examples of such a composite fiber include a core-sheath type composite fiber and a side-by-side type composite fiber, similar to the first elastic fiber described above.

  When the second elastic fiber is made of a single fiber or a composite fiber containing an elastic resin and an inelastic resin, the ratio of the inelastic resin in the second elastic fiber is lower than the ratio of the inelastic resin in the first elastic fiber. It is preferable. The reason for this is that, as described above, the second elastic fiber is mainly used for imparting stretchability to the nonwoven fabric of the present invention. This is because it is advantageous to reduce the number. From this point of view, the ratio of the inelastic resin in the second elastic fiber is 5 to 30% by mass, particularly 5 to 15% by mass, provided that the ratio of the inelastic resin in the first elastic fiber is lower. preferable.

  Examples of the arrangement form of the second elastic fibers include a form in which staple fibers or continuous filaments of the second elastic fibers are randomly deposited on one surface of the first elastic fiber layer. In this case, the arrangement site of the second elastic fiber may be composed of 100% of the second elastic fiber, or may contain other elastic fiber or non-elastic fiber in addition to the second elastic fiber. . As another arrangement form, a form in which a plurality of continuous filaments are aligned in one direction at a predetermined interval can be mentioned. The arrangement form may be appropriately determined according to the degree of stretch required for the nonwoven fabric of the present invention and the specific application of the nonwoven fabric.

  It is preferable that the arrangement | positioning site | part of a 2nd elastic fiber is comprised from the web formed by the melt blown method, for example, and the web formed by the spun bond method. These web forming methods are well known in the art. In particular, when the second elastic fiber is manufactured by a melt blown method to form a web, there is an advantage that the water pressure resistance of the nonwoven fabric is increased. The high water pressure resistance of the nonwoven fabric is advantageous when the nonwoven fabric of the present invention is used as a constituent member of absorbent articles such as disposable diapers and sanitary napkins. On the other hand, in order to arrange the second elastic fiber in a state where a plurality of continuous filaments are aligned in one direction at a predetermined interval, for example, Japanese Patent Application Laid-Open No. 2008-179128 related to the previous application of the present applicant. What is necessary is just to employ | adopt the method of FIG.

  Whereas the arrangement form of the second elastic fibers is as described above, the arrangement form of the first elastic fibers includes, for example, a form in which the staple fibers or continuous filaments are randomly deposited. With such an arrangement, the first elastic fiber layer including the first elastic fibers is formed. Specific examples of the structure of the first elastic fiber layer include a web formed by a melt blown method, a web formed by a spunbond method, a web formed by a card method, and the like. When the 2nd elastic fiber is arrange | positioned between two 1st elastic fiber layers, and the nonwoven fabric is formed, each 1st elastic fiber layer may be comprised only from the 1st elastic fiber, or 1st In addition to the elastic fibers, other elastic fibers and non-elastic fibers may be included. When the first elastic fiber layer includes other elastic fibers and inelastic fibers in addition to the first elastic fibers, the ratio of the other elastic fibers and inelastic fibers is 30% by mass or less, particularly 15% by mass. The following is preferable.

In the nonwoven fabric of the present invention, regardless of the number of layers constituting the nonwoven fabric, the basis weight of the first elastic fiber layer containing the first elastic fibers, 3 to 20 g / m ^2, especially at 4~10g / m ² It is preferable from the viewpoint of imparting sufficient stretchability to the nonwoven fabric of the present invention and imparting a good texture. When disposing the second elastic fiber between the two first elastic fiber layers, the basis weights of the two first elastic fiber layers may be the same or different. The two first elastic fiber layers may have the same fiber composition or different fiber compositions. On the other hand, the arrangement amount of the second elastic fiber is preferably 0.5 to 15 g / m ² , particularly 1 to 8 g / m ² from the viewpoint of imparting sufficient stretchability to the nonwoven fabric of the present invention. The basis weight of the entire nonwoven fabric depends on its specific application, but when the nonwoven fabric is used as a constituent member of an absorbent article such as a disposable diaper or a sanitary napkin, the basis weight is the number of layers constituting the nonwoven fabric. Regardless, it is preferably 10 to 50 g / m ² , particularly 12 to 18 g / m ² . Since the nonwoven fabric of the present invention has sufficient stretching force, strength, concealability and touch, the basis weight of the entire nonwoven fabric can be reduced. In relation to the basis weight of the nonwoven fabric, the nonwoven fabric has a thickness of 0.1 to 2.5 mm, particularly 0.8 to 0.5 g / cm ² regardless of the number of layers constituting the nonwoven fabric. It is preferable that it is 1.3 mm. This thickness can be determined, for example, by the following method. First, a nonwoven fabric is cut | judged to the magnitude | size of 100 mm x 100 mm, and let this be a measurement piece. A plate of 12.5 g (diameter 56.4 mm) is placed on a measuring table of a smooth surface plate installed almost horizontally, and the position of the upper surface of the plate in this state is set as a reference point A for measurement. Next, the plate is removed, the measurement piece is placed on the measurement table, the plate is placed again thereon, and the position of the upper surface of the plate is defined as B. And the thickness of a nonwoven fabric is calculated | required from the difference of A and B. FIG. A laser displacement meter (manufactured by Keyence Corporation, CCD laser displacement sensor LK-080) can be used for position measurement of the upper surface of the plate.

  In the nonwoven fabric of this invention which has a multilayer structure, it is preferable that each layer is couple | bonded in the joint part formed discontinuously. By adopting such a bonding form, the nonwoven fabric of the present invention can sufficiently stretch and contract the first elastic fiber and the second elastic fiber existing between the bonding sites, and the nonwoven fabric itself has sufficient stretchability. Become. Such a binding site can be a consolidated site formed by, for example, hot embossing. Further, it may be a fusion site formed by ultrasonic bonding. Furthermore, it may be an adhesion site joined by an adhesive. Alternatively, it may be a binding site formed by the method described in Japanese Patent Application Laid-Open No. 2008-179128 related to the previous application of the present applicant. For example, the bonding sites can be formed in the form of scattered dots over the entire area of the nonwoven fabric. In this case, as the shape of the binding site, for example, a circle, an ellipse, a polygon, or a combination thereof can be adopted.

  The nonwoven fabric of the present invention can be expanded and contracted in at least one direction in the plane. In this case, when the first elastic fibers and the second elastic fibers are randomly arranged, the nonwoven fabric can be expanded and contracted in any direction within the plane. When the first elastic fiber and / or the second elastic fiber are arranged in a state oriented in a specific direction within the surface of the nonwoven fabric, the stretchability in the orientation direction becomes higher than the other directions. . The degree of stretchability of the present invention is preferably such that the maximum elongation is 30 to 500%, particularly 100 to 300%. The maximum elongation is a value measured in the direction in which the value becomes the largest in the plane of the nonwoven fabric. Further, the strength at 100% elongation is preferably 30 to 300 cN / 50 mm, particularly 80 to 200 cN / 50 mm in the same direction as the measurement direction of the maximum elongation. Further, after 100% elongation, the strength when returning to 50% elongation (return 50% elongation strength) is 15 to 150 cN / 50 mm, particularly 30 to 100 cN / 50 mm in the same direction as the measurement direction of maximum elongation. It is preferable. The maximum strength of the nonwoven fabric is 400 to 4000 cN / 50 mm, particularly 2000 to 3000 cN / 50 mm in the same direction as the measurement direction of the maximum elongation, and 400 to 4000 cN / 50 mm, particularly 1000 to 2000 cN / in the direction orthogonal to the measurement direction. It is preferable that it is 50 mm. Further, the residual strain of the nonwoven fabric is preferably 6 to 15%, particularly 6 to 12%, particularly 6 to 11% in the same direction as the measurement direction of the maximum elongation.

  The various physical properties are measured by the following methods. A rectangular test piece is cut out in a size of 200 mm in the stretch direction of the nonwoven fabric having stretch properties (after the development of stretch properties) and 50 mm in the direction perpendicular thereto. A test piece is attached to a tensile tester (Autograph AG-1k NIS manufactured by Shimadzu Corporation). The distance between chucks is 150 mm. The test piece is stretched at a speed of 300 mm / min in the stretching direction of the nonwoven fabric, and the load at that time is measured. The load at the maximum point at that time is the maximum strength. In addition, when the length of the test piece at that time is B and the length of the original test piece is A, {(BA) / A} × 100 is the maximum elongation (%). Also, a 100% elongation cycle test is performed, and the strength at 100% elongation is obtained from the load at 100% elongation. Furthermore, after 100% elongation, the ratio of the length that does not return immediately after returning to the origin at the same speed is measured, and the value is taken as the residual strain. Further, the strength at the time of 50% elongation is obtained from the load at the time of 50% elongation during the return.

  The nonwoven fabric of the present invention has the above-mentioned stretch properties, and on the surface of the nonwoven fabric, small ridges and small ridges extending in a streak-like manner in a direction crossing the stretch direction of the nonwoven fabric are alternately formed. It is preferable that Thereby, when the cross section of the thickness direction along the expansion-contraction direction of a nonwoven fabric is observed, the surface of this nonwoven fabric becomes a micro uneven structure. Due to such a concavo-convex structure, the nonwoven fabric of the present invention has a better texture.

  The small ridges and the small ridges may extend continuously in a direction intersecting with the stretch direction of the nonwoven fabric, particularly in a substantially orthogonal direction, or may extend discontinuously. When viewed in a cross section in the thickness direction along the stretch direction, it is preferable that the width of the ridges and the ridges is 30 to 2000 μm, particularly 100 to 800 μm, from the point that the surface texture of the nonwoven fabric becomes higher. This width may be the same in the ridges and the recesses or may be different. For the same reason, the height difference from the lowest part of the concave ridge to the highest part of the convex ridge is preferably 40 to 1000 μm, particularly preferably 100 to 600 μm. This width and height difference is obtained by cutting the nonwoven fabric in the thickness direction along the stretch direction, and observing the cut surface under a no load and in a non-stretched state (ie, relaxed state) using a microscope. It can be measured.

  When the above-mentioned small ridges and small ridges extend the nonwoven fabric of the present invention and release the extended state, the first elastic fiber layer containing the first elastic fibers is disposed on the second elastic fiber. Formed when it contracts more slowly. It is preferable that the arrangement | positioning site | part of the 1st elastic fiber layer containing a 1st elastic fiber and a 2nd elastic fiber has the expansion-contraction characteristic which such a phenomenon expresses. In order for the arrangement | positioning site | part of the 1st elastic fiber layer containing a 1st elastic fiber, and a 2nd elastic fiber to have such an expansion-contraction characteristic, for example, the intensity | strength-distortion curve of the 1st elastic fiber layer containing a 1st elastic fiber The expansion / contraction characteristics of both may be adjusted so that the rising slope of the strength-strain curve of the second elastic fiber placement site is larger than the rising slope of the second elastic fiber. In addition, when the strength of the first elastic fiber (at 70% elongation) is 40% or less, particularly 5 to 20% of the strength of the second elastic fiber, the above-described stretch characteristic is more remarkably exhibited. preferable.

  Moreover, in order to express the above-mentioned expansion / contraction characteristic more remarkably, the strength of the arrangement part of the second elastic fiber-the strength of the first elastic fiber layer including the first elastic fiber with respect to the strength of the return of the strain curve- The return strength of the strain curve is preferably 30% or less, particularly 5 to 15%. By doing so, when the stretched nonwoven fabric is released from the stretched state, the nonwoven fabric shrinks without resistance. Therefore, even if the basis weight of the second elastic fiber is set low, a nonwoven fabric having a high shrinking force can be obtained. Since it becomes easy, it is preferable. Moreover, it is preferable at the point by which the floating of the excess fiber of the 1st elastic fiber layer by extending | stretching process is suppressed.

  In addition, the arrangement | positioning site | part of a 2nd elastic fiber is the deposition site | part, when the staple fiber or continuous filament of a 2nd elastic fiber is deposited on one side of the 1st elastic fiber layer at random. Say. When the second elastic fibers composed of a plurality of continuous filaments are arranged so as to be aligned in one direction at a predetermined interval, it refers to an aggregate of the plurality of second elastic fibers.

  The measurement method of the intensity-strain curve is as follows. The nonwoven fabric is brought into a natural state (relaxed state) and cut into a size of 200 mm in the direction of expansion and contraction and 50 mm in a direction orthogonal thereto, to obtain a rectangular test piece. This test piece is marked with a distance of 150 mm between the chucks. This test piece is peeled into the first elastic fiber layer including the first elastic fibers and the arrangement site of the second elastic fibers. When the first elastic fiber layer and the arrangement site are not obtained in a sheet form and the second elastic fiber is made of an elastomer resin, the nonwoven fabric is subjected to the following measurement, and then the second elastic fiber is subjected to the second elasticity. The first elastic fiber layer is obtained by dissolving and removing the fiber with toluene or the like, and the following measurement is performed again on the first elastic fiber layer. And the value which deducted the measurement result obtained about the 1st elastic fiber layer from the measurement result obtained about the nonwoven fabric can be calculated | required as a 2nd elastic fiber part.

  The peeled first elastic fiber layer and the arrangement site are mounted on a tensile tester (Autograph AG-1kNIS manufactured by Shimadzu Corporation). The distance between chucks is 150 mm as described above, and chucking is performed at the marking portion. The test piece is stretched in the stretching direction of the nonwoven fabric at a speed of 300 mm / min, and after 100% stretching, immediately returns to the origin at the same speed, and the 100% stretching cycle test is performed, whereby the first elastic fiber layer and the above-mentioned The intensity-distortion curve of the arrangement site is obtained. The rising slope of the strength-strain curve (strength of the first elastic fiber layer including the first elastic fiber and the second elastic fiber) is the value when the elongation is 70%. It is assumed that the slope having a larger strength at the amount of elongation is larger. The return strength of the strength-strain curve is the strength when the strength returns to 70% after 100% elongation. In the case where the elongation does not reach 100%, 70% of the maximum elongation is taken as 100%, and the same measurement is performed.

  Next, the detail of the 1st elastic fiber and 2nd elastic fiber which are used in the nonwoven fabric of this invention is demonstrated. As described above, the first elastic fiber includes an elastic resin and an inelastic resin as constituent components. An elastic resin is a resin that exhibits substantially elastic characteristics. When an external force is applied and stretched by a factor of 1.5, the external force is removed and then returned to its original length. It means a resin that returns to 1.25 times or less. On the other hand, the non-elastic resin shows substantially inelastic characteristics, and when the external force is applied and stretched by a factor of 1.5, the external force is removed and the length is immediately restored. It means something that does not return to less than 1.25 times the original length.

  Examples of the elastic resin in the first elastic fiber include a thermoplastic elastomer and rubber. It is particularly preferable to use a thermoplastic elastomer. This is because the thermoplastic elastomer can be melt-spun using an extruder in the same manner as a normal thermoplastic resin, and the fibers thus obtained are easily heat-sealed. Thermoplastic elastomers include SBS (styrene / butadiene / styrene block copolymer), SIS (styrene / isoprene / styrene block copolymer), SEBS (styrene / ethylene / butylene / styrene block copolymer), and SEPS (styrene).・ Styrene elastomers such as ethylene / propylene / styrene block copolymers), polypropylene elastomers such as propylene-α olefin copolymers, olefin elastomers such as ethylene-propylene copolymers and ethylene-α olefin copolymers, Examples thereof include polyester elastomers and polyurethane elastomers. These can be used individually by 1 type or in combination of 2 or more types. In particular, use of a styrene-based elastomer, an olefin-based elastomer, or a combination thereof is preferable in terms of moldability, stretchability, and cost of the first elastic fiber.

  Examples of the inelastic resin in the first elastic fiber include polyolefins such as polyethylene (PE) and polypropylene (PP); polyesters such as low melting point polyethylene terephthalate; polyamides and the like. These resins can be used singly or in combination of two or more.

  In the first elastic fiber, additives (catalyst, polymerization terminator, antistatic agent, anti-degradation agent, yellowing agent, softening agent, plasticizer, antiblocking agent, viscosity reducing agent, coloring agent) Etc.) is added, when the amount of the additive is 2% by mass or less based on the mass of the first elastic fiber, the effect of the additive on the stretchability of the first elastic fiber is Since it is small, the additive is treated as being contained in each resin component. On the other hand, when the additive amount exceeds 2% by mass with respect to the mass of the first elastic fiber, the additive has a great effect on the stretchability of the first elastic fiber. Treat as an ingredient.

  It is preferable that the first elastic fiber has a thickness of 8 to 25 μm, particularly 10 to 20 μm from the viewpoint of obtaining a non-woven fabric having good touch and excellent breathability and concealability. The thickness said here is the thickness after performing the extending | stretching process in the suitable manufacturing method of the nonwoven fabric mentioned later.

  On the other hand, when the second elastic fiber is made of 100% elastic resin, the same elastic resin as that exemplified above with respect to the first elastic fiber can be used. When the second elastic fiber is composed of a composite fiber containing an elastic resin and a non-elastic resin, the elastic resin and the non-elastic resin can be the same as those exemplified above for the first elastic fiber. . In particular, the second elastic fiber is preferably a fiber manufactured by a melt blown method and made of 100% elastic resin from the viewpoint that it is easy to make the second elastic fiber thin to some extent. By making the second elastic fiber thin to a certain extent, it is possible to achieve both air permeability and concealment. The high concealability of the nonwoven fabric is advantageous in that when the nonwoven fabric is used as a constituent member of an absorbent article such as a disposable diaper or a sanitary napkin, it is difficult to visually recognize the absorbed body fluid from the outside. From this viewpoint, when the second elastic fiber is manufactured by the melt blown method, the thickness is preferably 2 to 25 μm, particularly preferably 10 to 20 μm. On the other hand, when the second elastic fiber is manufactured by a spunbond method, the thickness is preferably 8 to 30 μm, particularly 12 to 22 μm. When the second elastic fiber is manufactured by the method described in Japanese Patent Application Laid-Open No. 2008-179128 related to the previous application of the present applicant, the thickness is 30 to 200 μm, particularly 70 to 150 μm. It is preferable that

  When the second elastic fiber is composed only of an elastic resin, the second elastic fiber is preferably thicker than the first elastic fiber. The difference in thickness between the two fibers is more preferably 1.0 to 5.0 μm, and still more preferably 1.5 to 3.0 μm. This increases the interfiber distance of the second elastic fiber. The increase in the distance between the fibers of the second elastic fibers means that, in the manufacturing process of the nonwoven fabric in the form in which the second elastic fibers are arranged between the two first elastic fiber layers, when bonding using hot embossing or the like, This is advantageous in that the first elastic fibers contained in the pair of first elastic fiber layers are easily joined directly. This is because the first elastic fibers contained in the pair of first elastic fiber layers are directly bonded to each other, so that a nonwoven fabric having high strength and air permeability and less strength reduction due to stretching can be obtained. Further, since the second elastic fiber is not directly exposed on the surface of the nonwoven fabric, even if the second elastic fiber is thicker than the first elastic fiber, the touch of the nonwoven fabric is not affected.

  As a preferred combination of the first elastic fiber and the second elastic fiber, the first elastic fiber is composed of a core-sheath type composite fiber composed of a core of SEPS or ethylene-propylene copolymer and a sheath of polypropylene, The combination which consists of a single component fiber which an elastic fiber consists of SEPS100% is mentioned. As another preferable combination, the first elastic fiber is a core-sheath type composite fiber including an ethylene-propylene copolymer core and a polyethylene sheath, and the second elastic fiber is an ethylene-α-olefin copolymer 100. The combination which consists of the single component fiber which consists of% is mentioned. As yet another preferred combination, the first elastic fiber is composed of a core-sheath type composite fiber composed of a propylene-α-olefin copolymer core and a polypropylene sheath, and the second elastic fiber is a propylene-α-olefin copolymer. The combination which consists of a single component fiber which consists of 100% is mentioned. By using such a combination, when the first elastic fiber and the second elastic fiber are bonded using thermal bonding such as heat embossing in the manufacturing process of the nonwoven fabric of the present invention, the same type of resin is bonded. Since it contributes, it can join without requiring a high pressure compared with the case where this combination is not used. The fact that a high pressure is not required means that the fiber is hardly cut at the boundary of the embossed part, and as a result, a nonwoven fabric having a high maximum strength can be obtained.

  Next, the suitable manufacturing method of the nonwoven fabric of this invention is demonstrated. Here, description will be made by taking as an example the production of a nonwoven fabric in which the second elastic fibers are disposed between the two first elastic fiber layers. First, a first web or non-woven fabric to be one first elastic fiber layer is manufactured. Examples of the method for producing the web or nonwoven fabric include a spun bond method, a melt blown method, a spinning blow method, and a card method. In order to spin the first elastic fiber made of a composite fiber containing an elastic resin and an inelastic resin by these methods, a known spinning nozzle for the composite fiber may be used.

  Next, a 2nd elastic fiber is arrange | positioned on a 1st web or a nonwoven fabric. As a method for arranging the second elastic fibers, for example, a spunbond method, a melt blown method, a spinning blown method, a card method, or the like can be used. If these arrangement | positioning methods are employ | adopted, the 2nd elastic fiber which consists of a staple fiber or a continuous filament will be deposited at random. On the other hand, when the method described in FIG. 4 of Japanese Patent Application Laid-Open No. 2008-179128 described above is adopted, the second elastic fiber can be aligned in one direction with a plurality of continuous filaments at predetermined intervals. It can be arranged in the state. In this case, the second elastic fiber may be laminated with the first elastic fiber in a molten state or a solidified state. When the second elastic fiber is laminated in a molten state, it is preferable not to perform thermal bonding such as heat embossing on the laminated body.

  Thus, if the 2nd elastic fiber is arrange | positioned on a 1st web or a nonwoven fabric, the 2nd web or nonwoven fabric containing a 1st elastic fiber will be arrange | positioned on it. The method for producing the web or nonwoven fabric can be the same as the method for producing the first web or nonwoven fabric.

Next, partial bonding is applied to the constituent fibers in the thickness direction of the laminated body thus obtained. For the partial coupling, for example, a heat embossing device including a combination of an embossing roll and an anvil roll in which a large number of convex portions are formed on the peripheral surface, an ultrasonic coupling device, or the like is used. When performing partial bonding, the ratio of the total area of the binding sites in the target nonwoven fabric is 3 to 30%, particularly 5 to 15%, which gives sufficient and strength to the target nonwoven fabric, From the viewpoint of preventing delamination. For the same reason, the area of each binding site is preferably set to 0.10 to 0.80 mm ² .

  The nonwoven fabric obtained in this way has a certain degree of stretchability, but due to the non-elastic fibers contained in the first elastic fibers, sufficient stretchability tends to be hindered. Therefore, in this production method, it is advantageous to subject the nonwoven fabric after partial bonding to stretching. For the stretching process, for example, a stretching apparatus including a pair of concavo-convex rolls in which large-diameter portions and small-diameter portions are alternately formed in the axial length direction can be used. The nonwoven fabric can be stretched in a direction perpendicular to the conveying direction of the nonwoven fabric by keeping the uneven roll in mesh and passing the nonwoven fabric between both rolls. Such a stretching apparatus is described, for example, in FIG. 2 of Japanese Patent Application Laid-Open No. 2007-138374 related to the previous application of the present applicant.

  Or the extending | stretching apparatus provided with a pair of tooth space roll in which the tooth | gear and the tooth root were alternately formed in the circumferential direction can also be used as an extending | stretching apparatus. The non-woven fabric can be stretched in the conveying direction of the non-woven fabric by keeping the tooth gap roll meshed and passing the non-woven fabric between both rolls. Such a stretching apparatus is described, for example, in FIG. 4 of Japanese Patent Laid-Open No. 2008-179128 described above.

  The non-elastic resin contained in the first elastic fiber is plastically deformed by stretching the nonwoven fabric with the above-described stretching device. When the second elastic fiber contains an inelastic resin, the inelastic resin is also plastically deformed. As a result, the stretched nonwoven fabric can freely expand and contract within the range in which the inelastic resin is plastically deformed. Surprisingly, even when the non-elastic resin in the first elastic fiber is plastically deformed by stretching the non-woven fabric by the above-described stretching apparatus, peeling or the like is caused between the elastic resin and the non-elastic resin in the first elastic fiber. The present inventors have confirmed that this does not occur.

  In particular, by stretching the nonwoven fabric with the stretching device provided with the above-mentioned tooth gap roll and releasing the stretching, small convex strips and small concave strips extending in a streak shape in a direction intersecting the expansion and contraction direction on the surface of the nonwoven fabric. The part can be formed successfully.

  In addition, the nonwoven fabric before the stretching process, other nonwoven fabrics (for example, stretchable nonwoven fabrics, stretchable nonwoven fabrics, non-stretchable nonwoven fabrics, and non-stretchable nonwoven fabrics), films (for example, moisture permeable films, moisture permeable films, laminates) Film, apertured film, stretchable film, stretchable film, etc.) or paper (including stretchable paper with crepe), etc. are joined by heat (for example, heat embossing, ultrasonic sealing and hot air blowing) The composite nonwoven fabric may be obtained by bonding with an adhesive or the like. The obtained composite nonwoven fabric has properties such as high strength, high concealment, and leakproofness. This bonding or bonding may be performed in an intermittent pattern or may be performed entirely. A non-woven fabric before stretching and another non-woven fabric, film or paper are bonded with heat or an adhesive to obtain a composite non-woven fabric, and then the composite non-woven fabric is stretched by performing the stretching process on the composite non-woven fabric. Can be obtained. Especially non-stretched nonwoven fabric, stretchable nonwoven fabric, stretchable film (non-moisture permeable film, laminate film, perforated film, unstretched moisture permeable film (impermeable to moisture before stretching but expresses moisture permeability after stretching) Film), a moisture permeable film, preferably a moisture permeable film), or a stretchable paper to obtain a composite nonwoven fabric, and by stretching the composite nonwoven fabric, the stretchable nonwoven fabric, the stretchable film or The extensible paper preferably has fine irregularities on the surface in the cross section in the thickness direction along the stretch direction. The stretchable nonwoven fabric part has fine irregularities that match the irregularities, so that it can be integrated with an extensible nonwoven fabric, film, and paper to obtain a cloth-like appearance and has sufficient elasticity while having stretchability. It is preferable at the point which becomes a thing.

  The obtained nonwoven fabric may be used as it is. In the stretched state, other nonwoven fabrics (for example, stretchable nonwoven fabrics, stretchable nonwoven fabrics, non-stretchable nonwoven fabrics and non-stretchable nonwoven fabrics), films (for example, moisture permeable films, moisture permeable films, apertured films, stretchable materials) Film, stretchable film, etc.), paper (including stretchable paper with crepe), etc., and thermally bonded (for example, heat embossing, ultrasonic sealing, fusion by hot air blowing, etc.) or by adhesive You may join and use. This bonding or bonding may be performed in an intermittent pattern or may be performed entirely. Moreover, it can also sew with a cloth, a nonwoven fabric, a film, or paper in the state which expanded the obtained nonwoven fabric.

  In the bonding, when an adhesive is used, the first resin component is used as the first elastic fiber as a core in order to prevent the stretch property and strength from being reduced due to the penetration of the adhesive into the elastic resin. It is preferable to use a core-sheath type composite fiber having a resin component as a sheath, and to dispose an adhesive on the first elastic fiber layer side including the first elastic fiber.

  Moreover, the 1st elastic fiber layer containing a 1st elastic fiber may be an intermediate | middle layer, without being distribute | arranged to the surface of a nonwoven fabric. Furthermore, although it is desirable that the first elastic fiber and the second elastic fiber be directly joined, other fibers or films can be interposed therebetween. Moreover, the surface where the 2nd elastic fiber is arrange | positioned can also be made into a use surface, when the one where a friction is higher is preferable by a use.

  The nonwoven fabric of the present invention thus obtained is suitably used as a constituent member of absorbent articles such as disposable diapers and sanitary napkins. Specifically, liquid-permeable sheets (including surface sheets, sublayers, etc.) located on the skin side of the absorbent body, sheets constituting the outer surface of disposable diapers, waist parts, waist parts, leg parts, etc. It can be used as a sheet, a three-dimensional gather, and the like for imparting elastic stretchability. Moreover, it can be used as a sheet or the like for forming a wing of a sanitary napkin. Furthermore, even if it is other site | parts, it can be used for the site | part etc. which want to provide a stretching property. In addition to these uses, it can also be used for various uses such as medical disposable clothing, cleaning sheets, eye patches, masks, bandages, etc. by taking advantage of its good texture, stretchability, breathability and the like.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited to such examples. Unless otherwise specified, “%” and “part” mean “% by mass” and “part by mass”, respectively.

[Example 1]
A core-sheath type composite fiber having a core made of styrene / ethylene / propylene / styrene block copolymer (SEPS) as an elastic resin and a sheath made of polypropylene (PP) as an inelastic resin is used as the first elastic fiber. The mass ratio of SEPS and PP used was 20:80. A spinning blower was used for fiber forming, and a first surface web made of first elastic fibers having a fiber diameter of 15 μm was obtained on a conveyor net.

  Next, using SEPS, a second elastic fiber having a fiber diameter of 17 μm was laminated on the first surface web by a meltblown apparatus to obtain an intermediate web.

Further, in the same manner as the formation of the first surface web described above, the first elastic fiber was laminated on the intermediate web to form the second surface web. Thus, a laminate having a three-layer structure was obtained. The basis weight of the first and second surface webs was 15 g / m ² and the basis weight of the intermediate web was 10 g / m ² . The obtained laminate was joined by an ultrasonic embossing device. The joining conditions were an area ratio of 12% and a circular dot diameter of 0.8 mm. The laminated body after joining was stretched to obtain a target nonwoven fabric. The stretching process was performed by stretching to 2.1 times (110%) in the MD direction, which is the direction in which the nonwoven fabric expands and contracts most, using a pair of tooth-shaped meshing teeth.

  The physical properties shown in Table 1 were measured for the obtained nonwoven fabric. The measuring method is as described above. In addition, each physical property was performed about MD direction which is a direction where a nonwoven fabric stretches most. However, the maximum intensity was also performed in the CD direction. Moreover, the following reference | standard evaluated the blocking of the obtained nonwoven fabric, the external appearance, and the touch. The results are shown in Table 1. The obtained non-woven fabric could be stretched to 100% by hand and returned to 11% from that state. The stretching can be performed with a light force and can be stretched to a high elongation. Further, this nonwoven fabric had fine irregularities on its surface, was excellent in touch, had no delamination, and had high air permeability.

<Evaluation of blocking>
The non-stretched nonwoven fabric was wound up once to obtain a 500 m-long original fabric, and then stored for 5 days at 50 ° C. (humidity was good). The temperature was returned to room temperature, and the feeding property at 50 m from the winding core was evaluated. The case where it can be easily unwound is marked as ◎, and some sticking is observed, but the case where it can be unwound to the extent that it can be used is marked as ○, and the case where it is difficult to use because of sticking is marked as x.

<Appearance evaluation>
According to the visual observation of the panel, those having a good appearance (at least 3 points) on at least one side of the nonwoven fabric were marked with ◯, and those with less than 3 points were marked with ×. The evaluation was performed by five people with a five-step evaluation from 1 to 5 points, and the average score was obtained. The evaluation criteria are 5 points for preferable ones (having a minute wave shape and a fabric tone), 4 points for slightly preferable items, 3 points for normal items, 2 points for slightly unfavorable items (not preferable items) One having a large surface undulation such as rubber and rubber gathers was taken as one point.

<Evaluation of touch>
The touch of each surface of the nonwoven fabric was evaluated. For the touched surface, at least one of the touched surfaces (three or more points) may be marked with ◯, and less than three points with x. The evaluation was performed by five grades from 1 point to 5 points by 5 people, and the average score was obtained. Evaluation criteria are 5 (preferably soft and non-sticky), 4 (slightly preferable), 3 (normal), 2 (slightly unfavorable), unfavorable (hard or sticky) 1).

[Example 2]
A nonwoven fabric was obtained in the same manner as in Example 1 except that 3.0 times (200%) stretching was performed in the MD direction. The obtained nonwoven fabric was measured and evaluated in the same manner as in Example 1. The results are shown in Table 1. This nonwoven fabric could be stretched up to 170% by hand and returned to 12% from that state.

Example 3
A nonwoven fabric was obtained in the same manner as in Example 1 except that polyethylene (PE) was used as the inelastic resin for the first elastic fiber. The obtained nonwoven fabric was measured and evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 4
A nonwoven fabric was obtained in the same manner as in Example 1 except that the mass ratio of the core and the sheath in the first elastic fiber was 30:70. The obtained nonwoven fabric was measured and evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 5
A nonwoven fabric was obtained in the same manner as in Example 1 except that the second elastic fiber having a fiber diameter of 10 μm was used. This nonwoven fabric was higher in hiding than the nonwoven fabrics of the other examples. The obtained nonwoven fabric was measured and evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 6
As the second elastic fiber, a core-sheath type composite fiber containing an elastic resin and an inelastic resin was used. SEPS was used as the elastic resin, and this was placed on the core. PP was used as the inelastic resin, and this was placed in the sheath. The mass ratio of SEPS to PP was 90:10. The core-sheath type composite fiber had a fiber diameter of 17 μm. Except for these, a nonwoven fabric was obtained in the same manner as in Example 1. The obtained nonwoven fabric was measured and evaluated in the same manner as in Example 1. The results are shown in Table 1. This nonwoven fabric had good embossing adhesion, and delamination was less likely to occur than the nonwoven fabrics of other examples.

Example 7
A core-sheath type composite fiber having a core made of styrene / ethylene / propylene / styrene block copolymer (SEPS) as an elastic resin and a sheath made of polypropylene (PP) as an inelastic resin is used as the first elastic fiber. Using. The mass ratio of SEPS and PP was 20:80. A spinning blower was used for fiber forming, and a first surface web made of first elastic fibers having a fiber diameter of 15 μm was obtained on a conveyor net.

Next, SEPS and PP were blended at a mass ratio of 80:20, and the second elastic fiber was laminated on the first surface web by a melt blown device to obtain a laminate having a two-layer structure. The basis weight of the first surface web was 15 g / m ² , and the basis weight of the second elastic fiber was 10 g / m ² . Thereafter, embossing was performed in the same manner as in Example 1. Hot melt was applied to the first elastic fiber side of the laminate thus obtained. A microporous moisture-permeable sheet 20 g / m ² containing calcium carbonate was bonded to the coated surface, and the laminated body after the bonding was stretched to obtain a moisture-permeable composite nonwoven fabric having leak-proof properties. . The stretching process is performed by first stretching 1.3 times (30%) in the CD direction of the nonwoven fabric using a pair of tooth-shaped meshing teeth in which a large diameter portion and a small diameter portion are alternately formed in the axial length direction. Then, using a pair of tooth gap rolls in which teeth and roots are alternately formed in the circumferential direction, the nonwoven fabric is stretched up to 1.5 times (50%) in the MD direction, which is the direction in which the nonwoven fabric stretches most. It was. The obtained composite nonwoven fabric was subjected to the same measurement and evaluation as in Example 1. The results are shown in Table 1. The obtained moisture-permeable composite nonwoven fabric had good stretchability in both directions and had sufficient strength. This was used as a stretchable back sheet of the diaper so that the MD direction of the nonwoven fabric was the lateral direction of the diaper (when worn). The obtained diaper was able to stretch greatly compared to the one using a non-stretchable backsheet, easy to wear, excellent fit when worn, and easy to move because the entire diaper stretches.

[Comparative Example 1]
A non-woven fabric was obtained in the same manner as in Example 1 except that inelastic fibers made of PP were used instead of the first elastic fibers, and the first web was formed using a spinning blower apparatus. The obtained nonwoven fabric was measured and evaluated in the same manner as in Example 1. The results are shown in Table 1. This non-woven fabric had low strength due to inelastic fibers being cut after stretching.

[Comparative Example 2]
A nonwoven fabric was obtained in the same manner as in Example 1 except that the mass ratio of the elastic resin and the non-elastic resin of the first elastic fiber was 50:50. The obtained nonwoven fabric was measured and evaluated in the same manner as in Example 1. The results are shown in Table 1. In this nonwoven fabric, the strength of the first elastic fiber was low, and the maximum strength of the entire nonwoven fabric was lowered. In addition, since the first elastic fiber returned to the original length after stretching, the stretch of the fiber was small and the thickness became thin, and the touch was lowered.

Claims (4)

The second elastic fiber is disposed on one surface of the elastic fiber layer including the first elastic fiber, and is a non-woven fabric that can expand and contract in at least one direction,
The first elastic fiber includes a first resin component made of an elastic resin and a second resin component made of an inelastic resin, and the second resin component exists at least part of the fiber surface continuously in the length direction. and it is made of composite fibers, and Ri ratio 70 to 96% by mass of the second resin component in the first elastic fiber,
The second elastic fiber includes a single fiber including an elastic resin and an inelastic resin, or an elastic resin and an inelastic resin, and the inelastic resin continuously exists in the length direction at least a part of the fiber surface. Made of composite fiber,
Ratio of the non-elastic resin in the second elastic fibers, that is lower than the ratio of the non-elastic resin in the first elastic fiber nonwoven fabric. The nonwoven fabric according to claim 1 , wherein the proportion of the non-elastic resin in the second elastic fiber is 5 to 30% by mass. Small ridges and small ridges extending in a streak-like manner in a direction intersecting with the expansion / contraction direction are alternately formed on the surface of the nonwoven fabric, whereby the surface becomes minute irregularities in the cross section in the thickness direction along the expansion / contraction direction. The nonwoven fabric according to claim 1 or 2 . A composite nonwoven fabric in which the nonwoven fabric according to any one of claims 1 to 3 and an extensible nonwoven fabric, an extensible film, or an extensible paper are bonded by heat or an adhesive, A composite nonwoven fabric having a surface with minute irregularities in a cross section in the thickness direction along the stretching direction.