WO2016060238A1 - Nonwoven fabric - Google Patents

Abstract

A nonwoven fabric (1A) according to the present invention has multiple thermally fusion-bonded parts (12) which are formed by thermally fusing-bonding intersection points between constituent fibers (11) to each other. The constituent fibers (11) include highly-stretchable fibers. In each of the constituent fibers (11), there is a large diameter portion (17) between adjacent two thermally fusion-bonded parts (12, 12), wherein the large diameter portion (17) has a larger fiber diameter and is sandwiched between two small diameter portions (16, 16) each having a smaller fiber diameter. Each of the constituent fibers (11) is so configured that the hydrophilicity of each of the smaller diameter portions (16) is smaller than that of the larger diameter portion (17).

Description

Non-woven

The present invention relates to a nonwoven fabric.

The applicant previously arranged a web containing low-stretch non-elastic fibers on one side of the web containing elastic fibers, and subjected the air-through hot air treatment to these webs to intersect the fibers. Proposed a technique relating to a non-woven fabric produced by stretching a fiber sheet formed by integrating these webs to stretch the low-elasticity non-elastic fiber, and then releasing the stretching of the fiber sheet. (Patent Document 1). In the method for producing a nonwoven fabric described in Patent Document 1, when a fiber sheet is stretched, a stretching apparatus including a pair of concavo-convex rolls that can be engaged with each other is used. In addition to Patent Document 1, for example, Patent Documents 2, 4, and 5 describe techniques for stretching using such a stretching apparatus including a pair of concave and convex rolls.

As another technique, Patent Document 3 discloses a technique relating to a water-permeable nonwoven fabric provided with a water-permeability imparting agent for textiles.

JP 2008-7924 A JP 2013-189745 A Japanese Patent Laid-Open No. 2000-178876 JP 2010-119861 A JP 2012-67426 A

The nonwoven fabric manufactured by the manufacturing method described in Patent Document 1 is formed to include elastic fibers and non-elastic fibers whose thickness along the longitudinal direction is not uniform. Thus, when the thickness of the non-elastic fiber is not uniform, the touch is good. However, there is no description regarding improvement of dry touch properties with little liquid remaining on the surface.

In Patent Document 2, it is essential to use stretchable fibers, that is, elastic fibers. And although patent document 2 has description of making the fiber diameter of a fiber thin with an extending | stretching apparatus, it is not described at all about the improvement of dry touch property with few liquid residues on the surface.

Moreover, since the water-permeable nonwoven fabric described in Patent Document 3 is provided with a water-permeability imparting agent, there is little liquid residue on the surface and dry touch properties are improved. However, Patent Document 3 relates to changing the hydrophilicity by stretching the constituent fibers to form a portion having a small fiber diameter and a portion having a large fiber diameter, and stretching the fiber to which the oil agent is attached. I don't expect anything.

The nonwoven fabric manufactured by the manufacturing method described in Patent Document 1 is formed to include elastic fibers and non-elastic fibers whose thickness along the longitudinal direction is not uniform. Thus, when the thickness of the non-elastic fiber is not uniform, the touch is good. However, there was a need to improve the feel.

In Patent Document 2, it is essential to use stretchable fibers, that is, elastic fibers. And in patent document 2, although there exists description of making the fiber diameter of a fiber thin with an extending | stretching apparatus, the part with a thin fiber diameter and the part with a large fiber diameter are formed in one fiber, and fiber There is no description on what position the boundary between the narrow diameter part and the thick part is arranged.

In Patent Document 4, there is no description regarding the use of high elongation fibers. In addition, Patent Document 4 does not describe anything about reducing the fiber diameter of the fiber by a drawing device, and includes a portion having a small fiber diameter and a portion having a large fiber diameter in one fiber. No assumptions are made about the formation.

Moreover, in patent document 5, nothing is described regarding using a high elongation fiber. Further, Patent Document 5 describes that the core sheath is peeled off by a stretching device to reduce the fiber diameter, but in what position the boundary between the thin part and the thick part is arranged. Is not described at all.

Therefore, an object of the present invention is to provide a non-woven fabric that can eliminate the above-mentioned drawbacks of the prior art.

The present invention (first invention) relates to a nonwoven fabric provided with a plurality of fusion parts formed by heat-sealing intersections of constituent fibers. The constituent fiber includes a high elongation fiber, and pays attention to one constituent fiber, and the constituent fiber is sandwiched between two small-diameter portions having a small fiber diameter between the adjacent fused portions. And a large diameter portion having a large fiber diameter. The hydrophilicity of the small diameter part is smaller than the hydrophilicity of the large diameter part.

The present invention (second invention) relates to a nonwoven fabric provided with a plurality of fused portions formed by heat-sealing the intersections of the constituent fibers. The constituent fibers include high elongation fibers. Paying attention to one of the constituent fibers, the constituent fiber has a large diameter portion having a large fiber diameter sandwiched between two small diameter portions having a small fiber diameter between the adjacent fused portions. ing. The changing point from the small diameter portion adjacent to the fusion portion to the large diameter portion is arranged within a range of 1/3 of the interval between the fusion portions adjacent to the fusion portion.

FIG. 1 is a perspective view showing an embodiment of the nonwoven fabric of the present invention (first invention). FIG. 2 is a schematic diagram showing a cross section in the thickness direction of the nonwoven fabric shown in FIG. FIG. 3 is a diagram illustrating a state in which the constituent fibers constituting the nonwoven fabric shown in FIG. 1 are fixed at the heat-sealing portion. FIG. 4 is a schematic view showing a manufacturing apparatus suitably used for manufacturing the nonwoven fabric shown in FIG. FIG. 5 is a schematic diagram illustrating an extending portion included in the manufacturing apparatus illustrated in FIG. 4. 6 is a cross-sectional view taken along the line VI-VI shown in FIG. FIG. 7A to FIG. 7C are explanatory views for explaining a state in which a plurality of small diameter portions and large diameter portions are formed in one constituent fiber between adjacent fused portions.

FIG. 8 is a perspective view showing an embodiment of the nonwoven fabric of the present invention (second invention). FIG. 9 is a schematic diagram showing a cross section in the thickness direction of the nonwoven fabric shown in FIG. FIG. 10 is a diagram for explaining a state in which the constituent fibers constituting the nonwoven fabric shown in FIG. 8 are fixed at the heat fusion part. FIG. 11 is a schematic diagram showing a manufacturing apparatus suitably used for manufacturing the nonwoven fabric shown in FIG. FIG. 12 is a schematic diagram illustrating an extending portion included in the manufacturing apparatus illustrated in FIG. 11. 13 is a cross-sectional view taken along line VI-VI shown in FIG. 14 (a) to 14 (c) are explanatory views for explaining a state in which a plurality of small diameter portions and large diameter portions are formed in one constituent fiber between adjacent fused portions.

Detailed Description of the Invention

Hereinafter, the present invention (first invention) will be described based on preferred embodiments with reference to the drawings.
FIG. 1 shows a perspective view of a nonwoven fabric 1A (hereinafter also referred to as “nonwoven fabric 1A”) which is an embodiment of the present invention (first invention). FIG. 2 is a schematic diagram showing a cross section in the thickness direction of the nonwoven fabric 1A shown in FIG. FIG. 3 is an enlarged schematic view of the constituent fibers 11 of the nonwoven fabric 1A shown in FIG. As shown in FIG. 3, the nonwoven fabric 1 </ b> A is a nonwoven fabric provided with a plurality of fusion portions 12 formed by thermally fusing the intersections of the constituent fibers 11. Here, the intersection of the constituent fibers 11 is also a joint point of the constituent fibers 11. The joint point is formed by heat-sealing the constituent fibers 11. That is, the joining point is the fused portion 12. And in this embodiment, as shown in FIG. 1, the nonwoven fabric 1A is a nonwoven fabric having a concavo-convex structure in which streaky ridges 13 and ridges 14 extending in one direction (X direction) are alternately arranged. is there. Specifically, as shown in FIG. 2, the nonwoven fabric 1 </ b> A is adjacent to a plurality of ridges 13 in which the cross-sectional shapes of both the front and back surfaces a and b are convex upward in the thickness direction (Z direction). It has the concave line part 14 located between the convex line parts 13 and 13 which fit. The concave stripe part 14 has a concave shape in which the cross-sectional shapes of the front and back surfaces a and b are both upward in the thickness direction (Z direction) of the nonwoven fabric. In other words, as for the concave strip part 14, the cross-sectional shape of front and back both surfaces a and b has comprised the convex shape toward the downward direction of the thickness direction (Z direction) of a nonwoven fabric. Each of the plurality of ridges 13 extends continuously in one direction (X direction) of the nonwoven fabric 1A, and each of the plurality of ridges 14 also extends in the one direction X of the nonwoven fabric 1A. I am doing. The ridges 13 and the ridges 14 are parallel to each other and are alternately arranged in a direction (Y direction) orthogonal to the one direction (X direction).

In addition, the nonwoven fabric 1A has a top region 13a, a bottom region 13b, and a side region 13c located between these 13a and 13b in a cross-sectional view of the nonwoven fabric 1A as shown in FIG. And the top part of the protruding item | line part 13 is formed from the top part area | region 13a, and the bottom part of the grooved part 14 is formed from the bottom part area | region 13b. The top region 13a, the bottom region 13b, and the side region 13c extend continuously in one direction (X direction) of the nonwoven fabric 1A. As shown in FIG. 2, the top region 13a, the bottom region 13b, and the side region 13c are cross-sectional views of the nonwoven fabric 1A, and divide the thickness of the nonwoven fabric 1A in the Z direction into three equal parts. Are divided into a top region 13a, a central region in the thickness direction (Z direction) as a side region 13c, and a lower region in the thickness direction (Z direction) as a bottom region 13b. The said division is measured by the following method.

[Method of dividing top region 13a, bottom region 13b, and side region 13c]
The non-woven fabric 1A was cut in the Y direction using a feather razor (part number FAS-10, manufactured by Feather Safety Razor Co., Ltd.), and the site measured with a scanning electron microscope (JCM-5100 (trade name) manufactured by JEOL Ltd.) Enlarged to a size (10 to 100 times) that can be fully measured and measured, and divides the thickness of the non-woven fabric 1A in the Z direction into three equal parts, and the upper region in the thickness direction (Z direction) is the top region 13a, the thickness direction The central region in the (Z direction) is distinguished as the side region 13c, and the lower region in the thickness direction (Z direction) is distinguished as the bottom region 13b.
When analyzing from a commercially available diaper or the like, a cold spray is sprayed on the target diaper or the like to cool the diaper or the like, thereby reducing the adhesive strength. Then, each material is carefully peeled off to obtain a target nonwoven fabric, which is cut and measured as described above.

As will be described later, the nonwoven fabric 1A is manufactured by subjecting the fiber sheet 1a to a concavo-convex process using a pair of concavo- convex rolls 401 and 402 meshing with each other. The one direction (X direction) of the nonwoven fabric 1A described above is the same direction as the machine direction (MD, flow direction) when the nonwoven fabric 1A is manufactured by performing uneven processing on the fiber sheet 1a. The direction (Y direction) orthogonal to the direction (X direction) is the same direction as the orthogonal direction (CD, roll axis direction) orthogonal to the machine direction (MD, flow direction).

The constituent fibers 11 of the nonwoven fabric 1A include high elongation fibers. Here, the high elongation fiber included in the constituent fiber 11 means not only a fiber having a high elongation at the raw material fiber stage but also a fiber having a high elongation at the stage of the manufactured nonwoven fabric 1A. As the “high elongation fiber”, excluding stretchable fibers that have elasticity (elastomer) and expand and contract, for example, as described in paragraph [0033] of JP 2010-168715, melt spinning is performed at a low speed to form a composite After obtaining the fiber, the heat-extensible fiber, which is obtained by changing the crystal state of the resin by heating and / or crimping without stretching, or polypropylene or polyethylene Fibers manufactured using relatively low spinning speeds using a resin such as polyethylene, polypropylene-polypropylene copolymers with low crystallinity, or fibers manufactured by dry blending polyethylene into polypropylene and spinning, etc. Is mentioned. Among these fibers, the high elongation fiber is preferably a core-sheath type composite fiber having heat-fusibility. The core-sheath type composite fiber may be a concentric core-sheath type, an eccentric core-sheath type, a side-by-side type, or a deformed type, but is preferably a concentric core-sheath type. Whatever form the fiber takes, from the viewpoint of producing a nonwoven fabric that is soft and soft to the touch, the fineness of the high elongation fiber may be 1.0 dtex or more at the raw material stage. Preferably, it is 2.0 dtex or more, more preferably 10.0 dtex or less, more preferably 8.0 dtex or less, specifically, 1.0 dtex or more and 10.0 dtex or less. Preferably, it is 2.0 dtex or more and 8.0 dtex or less. In this specification, the touch is a characteristic obtained by sensory evaluation of a sense when touching the skin in a state that does not contain a liquid. Moreover, the dry touch property mentioned later is the characteristic obtained by sensory evaluation of the feeling at the time of touching skin in the state containing the liquid residue. Therefore, dry touch and touch are different characteristics.

The constituent fibers 11 of the nonwoven fabric 1A may be configured to include other fibers in addition to the high elongation fibers, but are preferably configured only from inelastic fibers, and have a small diameter near the fusion point. In order to increase the number of fibers with low hydrophilicity, it is preferable that all fusion points are formed of high-stretch fibers, and therefore, it is more preferable that the fibers are composed of high-stretch fibers only. . Other fibers include, for example, a non-heat-extensible core-sheath-type heat-fusible composite fiber containing two components having different melting points, or a fiber that does not inherently have heat-fusibility ( Examples thereof include natural fibers such as cotton and pulp, rayon and acetate fibers). In the case where the nonwoven fabric 1A0 is configured to include other fibers in addition to the high elongation fibers, the proportion of the high elongation fibers in the nonwoven fabric 1A0 is preferably 50% by mass or more, and more preferably 80% by mass or more. And particularly preferably 100% by weight.

The heat-extensible fiber, which is an example of a high-stretch fiber, is a composite fiber that has been subjected to an unstretched or weakly stretched treatment at the raw material stage. For example, a first resin component that constitutes a core portion and a sheath portion And a second resin component containing a polyethylene resin, the first resin component having a higher melting point than the second resin component. A 1st resin component is a component which expresses the heat | fever extensibility of this fiber, and a 2nd resin component is a component which expresses heat-fusibility. The melting points of the first resin component and the second resin component were determined by thermal analysis of a finely cut fiber sample (sample weight 2 mg) using a differential scanning calorimeter (DSC6200 manufactured by Seiko Instruments Inc.) at a heating rate of 10 ° C./min. The melting peak temperature of each resin is measured and defined by the melting peak temperature. When the melting point of the second resin component cannot be clearly measured by this method, the resin is defined as “resin having no melting point”. In this case, the temperature at which the second resin component is fused to such an extent that the strength of the fusion point of the fiber can be measured is used as the temperature at which the molecular flow of the second resin component begins, and this is used instead of the melting point.

As above-mentioned, as a 2nd resin component which comprises a sheath part, the polyethylene resin is included. Examples of the polyethylene resin include low density polyethylene (LDPE), high density polyethylene (HDPE), and linear low density polyethylene (LLDPE). In particular, a high density polyethylene having a density of 0.935 g / cm ³ or more and 0.965 g / cm ³ or less is preferable. The second resin component constituting the sheath is preferably a polyethylene resin alone, but other resins can also be blended. Other resins to be blended include polypropylene resin, ethylene-vinyl acetate copolymer (EVA), ethylene-vinyl alcohol copolymer (EVOH), and the like. However, as for the 2nd resin component which comprises a sheath part, it is preferable that 50 mass% or more in the resin component of a sheath part is 70 to 100 mass% especially polyethylene resin. The polyethylene resin preferably has a crystallite size of 10 nm or more and 20 nm or less, and more preferably 11.5 nm or more and 18 nm or less.

As the first resin component constituting the core portion, a resin component having a melting point higher than that of the polyethylene resin that is a constituent resin of the sheath portion can be used without any particular limitation. Examples of the resin component constituting the core include polyolefin resins such as polypropylene (PP) (excluding polyethylene resin), polyester resins such as polyethylene terephthalate (PET), and polybutylene terephthalate (PBT). Furthermore, polyamide-based polymers, copolymers having two or more resin components, and the like can also be used. A plurality of types of resins can be blended and used. In this case, the melting point of the core is the melting point of the resin having the highest melting point. Since the nonwoven fabric can be easily manufactured, the difference between the melting point of the first resin component constituting the core part and the melting point of the second resin component constituting the sheath part (the former-the latter) is 20 ° C. or higher. It is preferable that it is 150 degrees C or less.

The preferred orientation index of the first resin component in the thermally stretchable fiber, which is an example of a high elongation fiber, is naturally different depending on the resin used. For example, when the first resin component is a polypropylene resin, the orientation index is 60% or less. More preferably, it is 40% or less, More preferably, it is 25% or less. When the first resin component is polyester, the orientation index is preferably 25% or less, more preferably 20% or less, and still more preferably 10% or less. On the other hand, the second resin component preferably has an orientation index of 5% or more, more preferably 15% or more, and still more preferably 30% or more. The orientation index is an index of the degree of orientation of the polymer chain of the resin constituting the fiber.

The orientation index of the first resin component and the second resin component is determined by the method described in paragraphs [0027] to [0029] of JP 2010-168715 A. A method for achieving the orientation index as described above for each resin component in the heat-extensible fiber is described in paragraphs [0033] to [0036] of Japanese Patent Application Laid-Open No. 2010-168715.

Further, the elongation of the high elongation fiber is 100% or more, preferably 200% or more, more preferably 250% or more, and preferably 800% or less at the raw material stage. More preferably, it is 500% or less, more preferably 400% or less, specifically, preferably 100% or more and 800% or less, more preferably 200% or more and 500% or less, and still more preferably 250%. More than 400%. By using a high elongation fiber having an elongation in this range, the fiber is successfully stretched in a stretching apparatus, and a change point 18 from a small diameter portion 16 to a large diameter portion 17 described later becomes a fusion portion 12. Adjacent and good touch. Further, the elongation of the high elongation fiber is 60% or more, preferably 70% or more, more preferably 80% or more, preferably 200% or less, at the stage of the nonwoven fabric. More preferably, it is 150% or less, more preferably 120% or less, specifically 60% or more and 200% or less, more preferably 70% or more and 170% or less, and further preferably 80% or more and 150% or less. is there. In particular, it is preferable that the elongation of the nonwoven fabric produced with a high elongation fiber ratio of 100% is in the above range.

The elongation of the high elongation fiber conforms to JISL-1015, and the measurement is based on the measurement environment temperature and humidity of 20 ± 2 ℃, 65 ± 2% RH, the tensile tester's gripping distance is 20mm, and the tensile speed is 20mm / min. And In addition, when collecting fibers from an already manufactured non-woven fabric and measuring the elongation, when the gripping interval cannot be 20 mm, that is, when the length of the fiber to be measured is less than 20 mm, the gripping interval is set. Measure by setting to 10 mm or 5 mm.

The ratio of the first resin component to the second resin component (mass ratio, the former: latter) in the high elongation fiber is 10:90 to 90:10, particularly 20:80 to 80:20, especially in the raw material stage. It is preferably 50:50 to 70:30. As the fiber length of the high elongation fiber, one having an appropriate length is used according to the method for producing the nonwoven fabric. For example, when the nonwoven fabric is manufactured by the card method as described later, the fiber length is preferably about 30 to 70 mm.

The fiber diameter of the high elongation fiber is appropriately selected according to the specific use of the nonwoven fabric at the raw material stage. When a nonwoven fabric is used as a constituent member of an absorbent article such as a surface sheet of an absorbent article, it is preferable to use one having a thickness of 10 μm or more, particularly preferably 15 μm or more, and one having a thickness of 35 μm or less. It is preferable to use a material having a thickness of 30 μm or less, and specifically, a material having a thickness of 10 μm to 35 μm, particularly 15 μm to 30 μm is preferable. The fiber diameter is measured by the following method.

[Measurement of fiber diameter]
As the fiber diameter, the fiber diameter (μm) is measured by observing the cross section of the fiber at 200 to 800 times using a scanning electron microscope (JCM-5100 manufactured by JEOL Ltd.). The cross section of the fiber is obtained by cutting the fiber using a feather razor (product number FAS-10, manufactured by Feather Safety Razor Co., Ltd.). For each extracted fiber, the fiber diameter when approximated to a circle is measured at five locations, and the average value of the five measured values is taken as the fiber diameter.

In the raw material stage, in the case of using a heat-extensible fiber, which is an example of a high elongation fiber, in addition to the above-described heat-extensible fiber, Japanese Patent No. 4131852, Japanese Patent Application Laid-Open No. 2005-350836, Japanese Patent Application Laid-Open No. 2007-2007 The fibers described in JP-A-303035, JP-A 2007-204899, JP-A 2007-204901, JP-A 2007-204902, and the like can also be used.

As shown in FIG. 3, the nonwoven fabric of the present invention (first invention) pays attention to one constituent fiber 11 among the constituent fibers 11 of the nonwoven fabric 1 </ b> A, and the constituent fibers 11 are adjacent to the fused portion 12. , 12 has a large-diameter portion 17 having a large fiber diameter sandwiched between two small- diameter portions 16, 16 having a small fiber diameter. Specifically, as shown in FIG. 3, paying attention to one constituent fiber 11 of the constituent fibers 11 of the nonwoven fabric 1A, a fusion formed by heat-sealing the intersection with the other constituent fibers 11 A small diameter portion 16 having a small fiber diameter extends from the landing portion 12 with substantially the same fiber diameter. Then, paying attention to the single constituent fiber 11, the large-diameter portion 17 having a fiber diameter larger than that of the small-diameter portion 16 between the small- diameter portions 16 and 16 extending from the adjacent fusion portions 12 and 12. Are extended with substantially the same fiber diameter. More specifically, the nonwoven fabric 1A pays attention to one constituent fiber 11, and from one fused portion 12 of adjacent fused portions 12, 12, toward the other fused portion 12, It has constituent fibers 11 arranged in the order of a small diameter portion 16 on the side of the attachment portion 12, one large diameter portion 17, and a small diameter portion 16 on the side of the other fusion portion 12. Further, as shown in FIG. 3, the nonwoven fabric 1 </ b> A pays attention to one constituent fiber 11 among the constituent fibers 11 of the nonwoven fabric 1 </ b> A, and has a large-diameter portion 17 between adjacent fusion portions 12, 12. The constituent fiber 11 is provided with a plurality of (two in the nonwoven fabric 1A). More specifically, the nonwoven fabric 1A pays attention to one constituent fiber 11, and from one fused portion 12 of adjacent fused portions 12, 12, toward the other fused portion 12, Constituent fibers arranged in the order of the small-diameter portion 16 on the bonding portion 12 side, the first large-diameter portion 17, the small-diameter portion 16, the second large-diameter portion 17, and the small-diameter portion 16 on the other fused portion 12 side. 11. As described above, the low-rigidity small-diameter portion 16 is adjacent to the fused portion 12 where the stiffness of the nonwoven fabric 1A is increased, so that the flexibility of the nonwoven fabric 1A is improved and the touch is improved. Moreover, the softness | flexibility of the nonwoven fabric 1A improves further and the touch becomes further better, so that the small diameter part 16 with a low rigidity is provided in the constituent fiber 11 in multiple numbers. In the nonwoven fabric 1A, focusing on one constituent fiber 11, preferably one large-diameter portion 17 is provided between the adjacent fusion portions 12 and 12 from the viewpoint of improving the touch and reducing the strength of the nonwoven fabric. More, more preferably 1 or more, and preferably 5 or less, more preferably 3 or less, specifically preferably 1 or more and 5 or less, more preferably 1 or more and 3 Has less than one.

The ratio (L ₁₆ / L ₁₇ ) of the fiber diameter (diameter L ₁₆ ) of the small diameter part 16 to the fiber diameter (diameter L ₁₇ ) of the large diameter part 17 is preferably 0.5 or more, more preferably 0.55 or more. And preferably it is 0.8 or less, More preferably, it is 0.7 or less, Specifically, Preferably it is 0.5 or more and 0.8 or less, More preferably, it is 0.55 or more and 0.7 or less. Specifically, the fiber diameter (diameter L ₁₆ ) of the small-diameter portion 16 is preferably 5 μm or more, more preferably 6.5 μm or more, particularly preferably 7.5 μm or more from the viewpoint of improving the touch and reducing the strength of the nonwoven fabric. And preferably 28 μm or less, more preferably 20 μm or less, particularly preferably 16 μm or less, specifically preferably 5 μm or more and 28 μm or less, more preferably 6.5 μm or more and 20 μm or less, particularly preferably 7. It is 5 μm or more and 16 μm or less. The fiber diameter (diameter L ₁₇ ) of the large diameter portion 17 is preferably 10 μm or more, more preferably 13 μm or more, particularly preferably 15 μm or more, preferably 35 μm or less, more preferably 25 μm or less, from the viewpoint of improving the touch. The thickness is particularly preferably 20 μm or less, specifically, preferably 10 μm or more and 35 μm or less, more preferably 13 μm or more and 25 μm or less, and particularly preferably 15 μm or more and 20 μm or less.
The fiber diameters (the diameters L ₁₆ and L ₁₇ ) of the small diameter part 16 and the large diameter part 17 are measured in the same manner as the fiber diameter measurement described above.

Further, the nonwoven fabric of the present invention (first invention) is formed such that the hydrophilicity of the small-diameter portion 16 is smaller than the hydrophilicity of the large-diameter portion 17. In order to impart such a change in hydrophilicity to the fiber, the nonwoven fabric 1A may be manufactured according to the manufacturing method described later.

The “hydrophilicity” referred to in the present invention (first invention) is judged based on the contact angle of the fiber measured by the method described below. Specifically, a low hydrophilicity is synonymous with a large contact angle, and a high hydrophilicity is synonymous with a small contact angle.

[Measurement method of contact angle]
A plurality of constituent fibers 11 of the nonwoven fabric 1A are randomly extracted, and the constituent fibers 11 including the small diameter portion 16 and the large diameter portion 17 are selected from the extracted constituent fibers 11, and the position of the small diameter portion 16 in the constituent fibers 11 and The contact angle of water at the position of the large diameter portion 17 is measured. As a measuring device, an automatic contact angle meter MCA-J manufactured by Kyowa Interface Science Co., Ltd. is used. Distilled water is used to measure the contact angle. The amount of liquid ejected from an ink jet type water droplet ejection part (manufactured by Cluster Technology, Inc., pulse injector CTC-25 with a pore diameter of 25 μm) is set to 15 picoliters, and the water droplets are positioned at the small diameter part 16 and the large diameter part. It is dripped just above the center of each of the 17 positions. The state of dripping is recorded on a high-speed recording device connected to a horizontally installed camera. The recording device is preferably a personal computer incorporating a high-speed capture device from the viewpoint of image analysis later. In this measurement, an image is recorded every 17 msec. In the recorded video, the first image in which water droplets land on the selected constituent fibers 11 is attached to the attached software FAMAS (software version is 2.6.2, the analysis method is the droplet method, and the analysis method is θ / 2. Method, image processing algorithm is non-reflective, image processing image mode is frame, threshold level is 200, and curvature correction is not performed). Calculate the contact angle. The selected constituent fiber 11 is cut into a fiber length of about 1 mm, and the fiber is placed on a sample table of a contact angle meter and kept horizontal. Two different contact angles are measured for the small diameter portion 16 and the large diameter portion 17 of one fiber. Measure the contact angle of N = 5 small diameter parts 16 and large diameter part 17 to one decimal place, and average the measured values of 10 places (rounded to the first decimal place). It is defined as the contact angle of the diameter portion 17.

The difference between the contact angle of the small-diameter portion 16 and the contact angle of the large-diameter portion 17 (the former-the latter) is 1 degree or more, particularly 5 degrees or more from the viewpoint of improving the dry touch property with little liquid remaining on the surface of the nonwoven fabric 1A Further, it is preferably 10 degrees or more, preferably 25 degrees or less, particularly preferably 20 degrees or less, and further preferably 15 degrees or less. For example, the difference in contact angle is preferably 1 degree or more and 25 degrees or less, more preferably 5 degrees or more and 20 degrees or less, and still more preferably 10 degrees or more and 15 degrees or less. Specifically, the contact angle of the small diameter portion 16 is 60 degrees or more, particularly 70 degrees or more, more preferably 80 degrees or more, and is preferably 100 degrees or less, particularly 95 degrees or less, and more preferably 90 degrees or less. preferable. For example, the contact angle of the small diameter portion 16 is preferably 60 degrees or more and 100 degrees or less, more preferably 70 degrees or more and 95 degrees or less, and still more preferably 80 degrees or more and 90 degrees or less. The contact angle of the large-diameter portion 17 is 55 degrees or more, particularly 60 degrees or more, more preferably 65 degrees or more, preferably 90 degrees or less, particularly 85 degrees or less, and more preferably 80 degrees or less. . For example, the contact angle of the large-diameter portion 17 is preferably 55 degrees or greater and 90 degrees or less, more preferably 60 degrees or greater and 85 degrees or less, and even more preferably 65 degrees or greater and 80 degrees or less.

Further, as shown in FIG. 3, the nonwoven fabric of the present invention (first invention) focuses on one constituent fiber 11 among the constituent fibers 11 of the nonwoven fabric 1 </ b> A, and has a small diameter portion 16 adjacent to the fused portion 12. The change point 18 from the large diameter portion 17 to the large diameter portion 17 is arranged within a range of ３ of the interval T between the fusion portions 12 and 12 adjacent to the fusion portion 12. Here, the change point 18 of the nonwoven fabric of the present invention (first invention) is a large diameter portion 17 extending from a small diameter portion 16 extending with a small fiber diameter and a fiber diameter larger than the small diameter portion 16. It does not include a part that continuously changes gradually or a part that continuously changes over a plurality of stages, and means a part where the fiber diameter changes extremely. When the one constituent fiber 11 is a core-sheath-type composite fiber, the change point 18 of the nonwoven fabric of the present invention (first invention) is the first resin component constituting the core part and the sheath part. It does not include a state in which the fiber diameter is changed by peeling with the second resin component to be configured, and means a portion where the fiber diameter is changed by stretching.

Further, the fact that the change point 18 is arranged within a range of 1/3 of the interval T between the adjacent fused portions 12 and 12 from the fused portion 12 means that the constituent fibers 11 of the nonwoven fabric 1A are randomly extracted. As shown in FIG. 3, the constituent fibers 11 can be observed between adjacent fused portions 12 and 12 of the constituent fibers 11 using a JCM-5100 (trade name) manufactured by JEOL Ltd. as a scanning electron microscope. (100 times to 300 times). Next, the interval T between the centers of the adjacent fused portions 12 and 12 is divided into three equal parts, and the region AT on the side of one fused portion 12, the region BT on the side of the other fused portion 12, and the center region CT Break down. This means that the change point 18 is arranged in the area AT or the area BT. Further, the non-woven fabric 1A in which the change point 18 is disposed within a range of 1/3 of the interval T between the adjacent fused portions 12 and 12 from the fused portion 12 means that the constituent fibers 11 of the non-woven fabric 1A are 20 When extracted randomly, the constituent fiber 11 in which the change point 18 is arranged in the region AT or the region BT means a nonwoven fabric in which at least one of the 20 constituent fibers 11 is present. Specifically, from the viewpoint of improving touch, it is preferably 1 or more, more preferably 5 or more, and particularly preferably 10 or more.

As will be described later, the nonwoven fabric 1A of the present embodiment extends not only the side region 13c but also the top region 13a that is the top of the ridge 13 and the bottom region 13b that is the bottom of the concave 14 by stretching, The fiber density of the whole nonwoven fabric is lower than the raw material nonwoven fabric before stretching. Thereby, the liquid permeability and air permeability of the nonwoven fabric 1A as a whole are improved. Among the top region 13a, the bottom region 13b, and the side region 13c, the side region 13c is particularly easy to be stretched and the fiber density is likely to decrease. In the side region 13c, liquid permeability and air permeability are particularly good. It has improved.

1 A of nonwoven fabrics of this embodiment form the fiber density of the side part area | region 13c smaller than the fiber density of the top part area | region 13a which is the top part of the protruding item | line part 13, and the fiber density of the bottom part area | region 13b which is the bottom part of the groove part 14. Has been. Here, the fiber density is the mass of the fiber per unit volume of the nonwoven fabric 1A. High fiber density means that the amount of fibers present per unit volume of the nonwoven fabric 1A is large and the distance between fibers is small. Low fiber density means that the amount of fibers present per unit volume of the nonwoven fabric 1A is small and the distance between fibers is large. In addition, the site | part with a high fiber density has high capillary force, and the site | part with a low fiber density has low capillary force.

As shown in FIG. 2, the nonwoven fabric 1 </ b> A is a cross-sectional view, and the nonwoven fabric 1 </ b> A is a fiber in the side region 13 c between the top (top region 13 a) of the ridge 13 and the bottom (bottom region 13 b) of the recess 14. The density is the smallest. Accordingly, in the side region 13c, the amount of fibers present per unit volume of the nonwoven fabric 1A is the smallest and the inter-fiber distance is the largest. As a whole, the nonwoven fabric 1A has improved air permeability and liquid permeability. improves. Furthermore, when the fiber density of the side region 13c is formed to be the smallest, the ridge portion 13 can easily follow the movement of the wearer's skin, and good skin contact can be realized. In order to impart such a fiber density to the side region 13c, the nonwoven fabric 1A may be manufactured according to the manufacturing method described later.

The ratio (D ₁₅ / D ₁₃ , D ₁₅ / D ₁₄ ) of the fiber density (D ₁₅ ) of the side region 13c to the fiber density (D ₁₃ ) in the top region 13a or the fiber density (D ₁₄ ) in the bottom region 13b. ) Is preferably 0.15 or more, more preferably 0.2 or more, and preferably 0.9 or less, more preferably 0.8 or less, and specifically preferably 0.15 or more. 0.9 or less, more preferably 0.2 or more and 0.8 or less. The specific value of the fiber density of the nonwoven fabric 1A is such that the fiber density (D ₁₃ ) in the top region 13a is preferably 80 / mm ² or more, more preferably 90 / mm ² or more, and Preferably it is 200 / mm ² or less, more preferably 180 / mm ² or less, specifically, preferably 80 / mm ² or more and 200 / mm ² or less, more preferably 90 / mm ² or more. 180 pieces / mm ² or less. Also, the fiber density _{(D 14)} of the bottom area 13b, preferably 80 present / mm ² or more, more preferably 90 present / mm ² or more, and preferably 200 present / mm ² or less, more preferably 180 / mm ² or less, specifically, preferably 80 / mm ² or more and 200 / mm ² or less, more preferably 90 / mm ² or more and 180 / mm ² or less. The fiber density of the side region 13c _{(D 15)} is preferably 30 present / mm ² or more, more preferably 40 present / mm ² or more, and preferably 80 present / mm ² or less, more preferably 70 / mm ² or less, specifically, preferably 30 / mm ² or more and 80 / mm ² or less, more preferably 40 / mm ² or more and 70 / mm ² or less. The fiber density of the top region 13 a is measured at a position near the top of the ridge 13. The fiber density of the bottom region 13b is measured at a position near the bottom point of the concave strip portion 14. The method for measuring the fiber density is as follows.

[Measuring method of fiber density in top region 13a, bottom region 13b or side region 13c]
The nonwoven fabric is cut using a feather razor (part number FAS-10, manufactured by Feather Safety Razor Co., Ltd.), and the fiber density in the top region 13a is obtained when the thickness of the cut surface of the nonwoven fabric is divided into three equal parts in the Z direction. The vicinity of the apex of the ridge 13 that is the portion of the region is magnified using a scanning electron microscope (adjusted to a magnification capable of measuring 30 to 60 fiber cross-sections; 150 to 500 times), and per fixed area (0.5 mm ^2). ) Of the cross section of the fiber cut by the cut surface. Next, it converts into the number of cross sections of the fiber per 1 mm < ² >, and makes this the fiber density in the top region 13a. The measurement is performed at three locations, and the average is the fiber density of the sample. Similarly, the fiber density in the bottom region 13b is obtained by measuring the vicinity of the bottom point of the concave portion 14 which is a lower portion when the thickness of the cut surface of the nonwoven fabric is equally divided into three in the Z direction. Similarly, the fiber density of the side region 13c is determined by measuring the central part when the thickness of the cut surface of the nonwoven fabric is equally divided into three in the Z direction. As the scanning electron microscope, JCM-5100 (trade name) manufactured by JEOL Ltd. is used.

Moreover, 1 A of nonwoven fabrics of this embodiment are the number of the fibers which have the change point 18 in the constituent fiber which the number of the fibers which have the change point 18 in the constituent fiber which comprises the side region 13c comprises the top region 13a and the bottom region 13b. More are formed. Thereby, the top region 13a can easily follow the movement of the wearer's skin, and good skin contact can be realized. The side region 13c with respect to the number of fibers having the change point 18 in the constituent fibers constituting the top region 13a (N ₁₃ ) or the number of fibers having the change point 18 in the component fibers constituting the bottom region 13b (N ₁₄ ) The ratio (N ₁₅ / N ₁₃ , N ₁₅ / N ₁₄ ) of the number (N ₁₅ ) of fibers having the change point 18 in the constituent fibers constituting is preferably 2 or more, more preferably 5 or more, and preferably Is 20 or less, more preferably 20 or less. Specifically, it is preferably 2 or more and 20 or less, more preferably 5 or more and 20 or less. Further, regarding the specific value of the number of fibers having the change point 18 of the nonwoven fabric 1A, the number of fibers having the change point 18 (N ₁₃ ) in the constituent fibers constituting the top region 13a is preferably one or more, and more Preferably it is 5 or more, and preferably 15 or less, more preferably 15 or less, specifically, preferably 1 or more and 15 or less, more preferably 5 or more and 15 or less. . The number (N ₁₄ ) of fibers having the change point 18 in the constituent fibers constituting the bottom region 13b is preferably 1 or more, more preferably 5 or more, and preferably 15 or less, more preferably Is 15 or less, and specifically, preferably 1 or more and 15 or less, more preferably 5 or more and 15 or less. The number (N ₁₅ ) of fibers having the change point 18 in the constituent fibers constituting the side region 13c is preferably 5 or more, more preferably 10 or more, and preferably 20 or less, The number is preferably 20 or less, specifically, preferably 5 or more and 20 or less, and more preferably 10 or more and 20 or less. The method for measuring the number of fibers having the change point 18 is as follows.

[Measurement method of the number of fibers having the change point 18 in the constituent fibers constituting the top region 13a, the bottom region 13b, or the side region 13c]
As for the number of fibers having the change point 18 in the constituent fibers 11 constituting the top region 13a, scanning electrons are scanned around the apex of the ridge 13 which is the upper part when the thickness of the nonwoven fabric is equally divided into three in the Z direction. Using a microscope, magnified observation (adjusted to a magnification capable of measuring 30 to 60 fiber cross sections; 50 to 500 times), 20 constituent fibers 11 constituting the top region 13a were randomly extracted, and 20 constituent fibers 11 were extracted. The number of fibers having the change point 18 in the is counted. When there are one or more change points 18 between the fused portions, the number of fibers having the change points 18 is set, and when there are a plurality of change points 18, the number is also set to one. This is the number of fibers having the change point 18 in the constituent fibers constituting the top region 13a. The measurement is performed at three places, and the average is the number of fibers having the change point 18 in the constituent fibers constituting the top region 13a of the sample. Similarly, regarding the number of fibers having the change point 18 in the constituent fibers 11 constituting the bottom region 13b, the vicinity of the bottom point of the concave portion 14 which is a lower portion when the thickness of the nonwoven fabric is equally divided into three in the Z direction. Determine by measuring. Similarly, the number of fibers having the change point 18 in the constituent fibers 11 constituting the side region 13c is obtained by measuring the central portion when the thickness of the nonwoven fabric is equally divided into three in the Z direction. As the scanning electron microscope, JCM-5100 (trade name) manufactured by JEOL Ltd. is used.

1 A of nonwoven fabrics of this embodiment are the disposable diapers which have the surface sheet arrange | positioned at the skin opposing surface side, the back sheet arrange | positioned at the non-skin opposing surface side, and the absorber interposed between the said both sheets, for example. Or it is used for absorbent articles, such as a sanitary napkin. In particular, of the constituent members of the absorbent article, the top sheet is formed from the nonwoven fabric 1A, or a liquid-permeable sublayer disposed between the top sheet and the absorbent body is formed from the nonwoven fabric 1A. Can be. When the surface sheet is formed of the nonwoven fabric 1A, the nonwoven fabric 1A is a nonwoven fabric having a concavo-convex structure, and therefore, the contact area ratio with the skin is lowered and it is further difficult to rub. Moreover, when the said surface sheet or the said sublayer is formed with the nonwoven fabric 1A, since the nonwoven fabric 1A is a nonwoven fabric of a concavo-convex structure, compression resistance improves, a feeling of cushion improves, and the return of body fluid can be prevented.

The thickness of the nonwoven fabric 1A, the entire thickness of when the side view of the nonwoven fabric 1A and sheet thickness T _S, the local thickness of the nonwoven fabric 1A curved in its irregularities and the layer thickness T _L. Sheet thickness _{T S} is may be adjusted as appropriate depending on the application, when used as a topsheet or sublayer of the absorbent article is preferably at least 0.5 mm, more preferably at least 1 mm, and preferably 7mm or less, 5 mm or less More specifically, 0.5 mm or more and 7 mm or less are preferable, and 1 mm or more and 5 mm or less are more preferable. By setting it as this range, the bodily fluid absorption speed | velocity at the time of use is quick, the liquid return from an absorber is suppressed, and also moderate cushioning property is realizable.

The layer thickness T _L may be different in each part in the nonwoven fabric 1A, and may be appropriately adjusted depending on the application. When used as a surface sheet or sublayer of an absorbent article, the layer thickness T _L1 of the top region 13a is preferably 0.1 mm or more, more preferably 0.2 mm or more, and 3.0 mm or less. Is preferably 2.0 mm or less, specifically 0.1 mm or more and 3.0 mm or less, more preferably 0.2 mm or more and 2.0 mm or less. The layer thickness T _L2 of the bottom region 13b is preferably 0.1 mm or more, more preferably 0.2 mm or more, and preferably 3.0 mm or less, more preferably 2.0 mm or less. Is preferably from 0.1 mm to 3.0 mm, more preferably from 0.2 mm to 2.0 mm. The layer thickness T _L3 of the side region 13c is preferably 0.1 mm or more, more preferably 0.2 mm or more, and preferably 3.0 mm or less, more preferably 2.0 mm or less. Specifically, it is preferably from 0.1 mm to 3.0 mm, and more preferably from 0.2 mm to 2.0 mm. By setting it as this range, the bodily fluid absorption speed | velocity at the time of use is quick, the liquid return from an absorber is suppressed, and also moderate cushioning property is realizable.

The sheet thickness T _S and the layer thickness T _L are measured by the following methods.
Method of measuring the thickness of the sheet _{T S} is in a state of applying a load of 0.05kPa nonwoven. 1A, measured by using a thickness gauge. A laser displacement meter manufactured by OMRON Corporation is used for the thickness measuring instrument. Thickness is measured at 10 points, and the average value is calculated as the thickness.
Measurement of layer thickness T _L, by enlarging the cross section of the sheet by Keyence Corporation Ltd. digital microscope VHX-900 by about 20 times, to measure the thickness of each layer.

When the nonwoven fabric 1A is viewed in plan, the pitch between the top regions 13a adjacent to each other in the Y direction may be appropriately adjusted depending on the application, and is preferably 1 mm or more when used as a surface sheet or sublayer of an absorbent article. 5 mm or more is more preferable, 15 mm or less is preferable, 10 mm or less is more preferable, specifically, 1 mm or more and 15 mm or less is preferable, and 1.5 mm or more and 10 mm or less is more preferable.

The basis weight of the nonwoven fabric 1A depends on the specific use of the nonwoven fabric 1A, but when used as a surface sheet or sublayer of an absorbent article, the average value of the entire sheet is preferably 15 g / m ² or more, and 20 g / m m ² or more is more preferable, and 50 g / m ² or less is preferable, 40 g / m ² or less is more preferable, specifically, 15 g / m ² or more and 50 g / m ² or less is preferable, and 20 g / m ² or more and 40 g. / M ² or less is more preferable.

Further, a fiber treating agent is attached to the surface of the constituent fiber 11 of the nonwoven fabric 1A. In particular, it is preferable that the fiber treatment agent is attached to the surface of the high elongation fiber in the constituent fibers 11 at the raw material stage. The fiber treatment agent preferably includes a spreadable component, and more preferably includes a spreadable component and a hydrophilic component. Here, the spreadable component refers to a component that, when attached to the surface of the fiber, easily spreads on the surface of the fiber at a low temperature and has excellent fluidity at a low temperature. Examples of such a spreadable component include a silicone resin having a low glass transition point and a flexible molecular chain. As the silicone resin, a polyorganosiloxane having a Si—O—Si chain as the main chain is preferable. Used. When the fiber treatment agent adhering to the fiber surface contains a spreadable component and a hydrophilic component, the spreadable component tends to spread when the fiber is stretched, and the hydrophilic component Is difficult to spread, and it is considered that the hydrophilicity of the stretched portion of the fiber changes.

Unless otherwise specified, the “fiber treatment agent” that is the standard for the content of the fiber treatment agent-containing component, such as a spreadable component, is “fiber treatment agent attached to the nonwoven fabric”. It is not a fiber treatment agent before adhesion. When the fiber treatment agent is attached to the uneven nonwoven fabric, the fiber treatment agent is usually diluted with an appropriate solvent such as water, so the content of the fiber treatment agent-containing component, for example, a fiber treatment agent of a spreadable component is used. The content in it can be based on the total mass of the diluted fiber treatment agent.

Also, whether or not it is a spreadable component is determined as follows. Specifically, the fiber treatment agent to be determined is applied to the surface of the high elongation fiber to which no other fiber treatment agent has been applied, and the hydrophilicity of the high elongation fiber to which the fiber treatment agent has been applied is described above. Measured based on [Measurement method of contact angle]. Next, the high elongation fiber to which the fiber treatment agent is applied is stretched 2.0 times to form the small diameter portion 16 and the large diameter portion 17. And the hydrophilicity in the formed large diameter part 17 is measured based on the above-mentioned [Measuring method of a contact angle]. And when the difference between the measured hydrophilicity of the high elongation fiber before stretching and the measured hydrophilicity of the large diameter portion 17 is 10 degrees or more, the component contained in the fiber treatment agent is ductile. Judge as an ingredient. In other words, the constituent fiber 11 having the small diameter portion 16 and the large diameter portion 17 is selected from the constituent fibers of the nonwoven fabric 1A, and the water contacts at the position of the small diameter portion 16 and the position of the large diameter portion 17 in the constituent fiber 11. The angle is measured based on the above-described [Measuring Method of Contact Angle]. And when the difference between the measured contact angle of the small-diameter portion 16 and the measured contact angle of the large-diameter portion 17 is 10 degrees or more, a spreadable component is contained in the fiber treatment agent. to decide. Moreover, when judging in the constituent fibers of the nonwoven fabric used in products such as commercially available diapers, the target nonwoven fabric is peeled off from the product, and the treatment agent is extracted using ethanol or an ethanol / methanol mixed solvent. Perform component analysis. Thus, the above-described measurement is performed on the identified component, and it is determined whether or not each component is a spreadable agent.

As the polyorganosiloxane, either a linear one or a cross-linked two-dimensional or three-dimensional network structure can be used. Preferably it is substantially linear.

Specific examples of suitable polyorganosiloxanes are alkylalkoxysilanes, arylalkoxysilanes, alkylhalosiloxane polymers or cyclic siloxanes, and the alkoxy groups are typically methoxy groups. As the alkyl group, an alkyl group which may have a side chain having 1 to 18 carbon atoms, preferably 1 to 8 carbon atoms, particularly 1 to 4 carbon atoms is suitable. Examples of the aryl group include a phenyl group, an alkylphenyl group, and an alkoxyphenyl group. Instead of an alkyl group or an aryl group, a cyclic hydrocarbon group such as a cyclohexyl group or a cyclopentyl group, or an aralkyl group such as a benzyl group may be used.

Preferred examples of the most typical polyorganosiloxane include polydimethylsiloxane, polydiethylsiloxane, polydipropylsiloxane and the like, with polydimethylsiloxane being particularly preferred.

The molecular weight of the polyorganosiloxane is preferably a high molecular weight. Specifically, the weight average molecular weight is preferably 100,000 or more, more preferably 150,000 or more, still more preferably 200,000 or more, preferably 1,000,000. Hereinafter, more preferably 800,000 or less, still more preferably 600,000 or less. Two or more types of polyorganosiloxanes having different molecular weights may be used as the polyorganosiloxane. When two or more types of polyorganosiloxanes having different molecular weights are used, one of them has a weight average molecular weight of preferably 100,000 or more, more preferably 150,000 or more, further preferably 200,000 or more, and preferably Is not more than 1 million, more preferably not more than 800,000, still more preferably not more than 600,000. The other one has a weight average molecular weight of preferably less than 100,000, more preferably not more than 50,000, more preferably 30,000. It is 5,000 or less, more preferably 20,000 or less, preferably 2000 or more, more preferably 3000 or more, and still more preferably 5000 or more. A preferable blending ratio (the former: latter) of the polyorganosiloxane having a weight average molecular weight of 100,000 or more and the polyorganosiloxane having a weight average molecular weight of less than 100,000 is a mass ratio, preferably 1:10 to 4: 1. More preferably, it is 1: 5 to 2: 1.

The weight average molecular weight of the polyorganosiloxane is measured using GPC. The measurement conditions are as follows. The calculated molecular weight is calculated with polystyrene.
Separation column: GMHHR-H + GMHHR-H (cation)
Eluent: L Farmin DM20 / CHCl ₃
Solvent flow rate: 1.0 ml / min
Separation column temperature: 40 ° C

The content of the polyorganosiloxane in the fiber treatment agent is preferably 1% by mass or more, more preferably 5% by mass or more, and more preferably 30% by mass or less from the viewpoint of increasing the change in the hydrophilicity of the fiber. Is preferable, and 20 mass% or less is still more preferable. Specifically, the content of the polyorganosiloxane in the fiber treatment agent is preferably 1% by mass or more and 30% by mass or less, and more preferably 5% by mass or more and 20% by mass or less.

Commercially available products can be used as the polyorganosiloxane. For example, “KF-96H-1 million Cs” manufactured by Shin-Etsu Chemical Co., Ltd., “SH200 Fluid 1000000 Cs” manufactured by Toray Dow Corning Co., Ltd., and Shin-Etsu Chemical Co., Ltd. “KM-903” manufactured by company or “BY22-060” manufactured by Toray Dow Corning Co., Ltd. can be used.

As the hydrophilic component, a zwitterionic surfactant or a nonionic surfactant can be used.

Examples of zwitterionic surfactants include alkyl (C1-30) betaines, alkyl (C1-30) amidoalkyl (C1-4) dimethylbetaine, alkyl (C1-30) Betaine-type zwitterionic surfactants such as dihydroxyalkyl (1-30 carbon atoms) betaine, sulfobetaine-type amphoteric surfactants, alanine type [alkyl (1-30 carbon atoms) aminopropionic acid type, alkyl (carbon Formula 1 to 30) Iminodipropionic acid type and the like] Amphoteric surfactant, Glycine type such as alkylbetaine [Alkyl (C1 to C30) aminoacetic acid type and the like] Amino acid type amphoteric surfactant such as amphoteric surfactant, Examples thereof include aminosulfonic acid type amphoteric surfactants such as alkyl (having 1 to 30 carbon atoms) taurine type. Of these, betaine-type zwitterionic surfactants are preferred, alkyl (C1-30) betaines are more preferred, and alkylbetaines having 16-22 carbon atoms (eg, stearyl) are particularly preferred.

Examples of nonionic surfactants include polyhydric alcohol fatty acid esters such as glycerin fatty acid esters, poly (preferably n = 2 to 10) glycerin fatty acid esters, sorbitan fatty acid esters (preferably those having 8 to 8 carbon atoms of fatty acids). 60), polyoxyalkylene (added mole number 2-20) alkyl (carbon number 8-22) amide, polyoxyalkylene (added mole number 2-20) alkyl (carbon number 8-22) ether, polyoxyalkylene-modified silicone And amino-modified silicone.

The fiber treatment agent preferably contains a hydrophobic component in addition to the spreadable component and the hydrophilic component. Examples of the hydrophobic component include alkyl phosphate esters, anionic surfactants represented by the following general formula (1) (hereinafter also simply referred to as “anionic surfactants”), and the like.

(Wherein Z represents an ester group, an amide group, an amine group, a polyoxyalkylene group, an ether group or a linear or branched alkyl chain having 1 to 12 carbon atoms, which may contain a double bond; R ₁ and R ₂ each independently represents an ester group, an amide group, a polyoxyalkylene group, an ether group or a linear or branched alkyl group having 2 to 16 carbon atoms, which may contain a double bond. , X represents —SO ₃ M, —OSO ₃ M or —COOM, and M represents H, Na, K, Mg, Ca or ammonium.)

Alkyl phosphate esters are incorporated into fiber treatment agents for the purpose of improving the properties of raw cotton through the card machine and the uniformity of the web, thereby improving the productivity of the nonwoven fabric and preventing the quality from deteriorating. . Specific examples of the alkyl phosphate ester include those having a saturated carbon chain such as stearyl phosphate ester, myristyl phosphate ester, lauryl phosphate ester, palmityl phosphate ester, oleyl phosphate ester, palmitoleyl phosphate ester, etc. Examples include unsaturated carbon chains and those having side chains in these carbon chains. More preferably, it is a completely neutralized or partially neutralized salt of a mono- or dialkyl phosphate ester having 16 to 18 carbon chains. Examples of the alkyl phosphate ester salt include alkali metals such as sodium and potassium, ammonia, and various amines. Alkyl phosphate ester can be used individually by 1 type or in mixture of 2 or more types.

The blending ratio of the alkyl phosphate ester is preferably 5% by mass or more, more preferably 10% by mass or more from the viewpoint of card machine passability and web uniformity, etc., and also depends on the polyorganosiloxane resulting from the heat treatment. From the viewpoint of not hindering the hydrophobicity of the fiber, it is preferably 30% by mass or less, more preferably 25% by mass or less.

The content ratio (the former: latter) of the polyorganosiloxane and the alkyl phosphate ester in the fiber treatment agent is preferably 1: 5 to 10: 1, more preferably 1: 2 to 3: 1 in terms of mass ratio. It is.

The anionic surfactant represented by the above general formula (1) refers to a component that does not contain the alkyl phosphate ester. Moreover, the anionic surfactant represented by the above general formula (1) can be used singly or in combination of two or more.

Examples of the anionic surfactant in which X in the general formula (1) is —SO ₃ M, that is, the hydrophilic group is a sulfonic acid or a salt thereof, include, for example, a dialkylsulfonic acid or a salt thereof. Specific examples of the dialkyl sulfonic acid include dioctadecyl sulfosuccinic acid, didecyl sulfosuccinic acid, ditridecyl sulfosuccinic acid, di-2-ethylhexyl sulfosuccinic acid, and the like, and dicarboxylic acids such as dialkyl sulfosuccinic acid and dialkyl sulfoglutaric acid. Saturated fatty acids and unsaturated fatty acids such as compounds sulfonated at the alpha position, 2-sulfotetradecanoic acid 1-ethyl ester (or amide) sodium salt, 2-sulfohexadecanoic acid 1-ethyl ester (or amide) sodium salt Alpha sulfo fatty acid alkyl esters (or amides) sulfonated at the α-position of esters (or amides), dialkyl alkenes obtained by sulfonating internal olefins of hydrocarbon chains and unsaturated fatty acids Such as sulfonic acid can be mentioned. The number of carbon atoms in each of the two-chain alkyl groups of the dialkyl sulfonic acid is preferably 4 or more and 14 or less, particularly 6 or more and 10 or less.

Specific examples of the anionic surfactant in which the hydrophilic group is sulfonic acid or a salt thereof include the following anionic surfactants.

Examples of the anionic surfactant in which X in the general formula (1) is —OSO ₃ M, that is, the hydrophilic group is sulfuric acid or a salt thereof, include dialkyl sulfates, and specific examples thereof include 2-ethylhexyl. Compounds with sulfated alcohols such as sodium sulfate and sodium 2-hexyldecyl sulfate, and alcohols with branched chains such as polyoxyethylene 2-hexyldecyl sulfate and polyoxyethylene 2-hexyldecyl sulfate And hydroxy fatty acid esters (or 12-sulfate stearic acid 1-methyl ester (or amide) 3-sulfate hexanoic acid 1-methyl ester (or amide) And compounds obtained by sulfating amides).

More specific examples of the anionic surfactant in which the hydrophilic group is sulfuric acid or a salt thereof include the following anionic surfactants.

As the anionic surfactant in which X in the general formula (1) is —COOM, that is, the hydrophilic group is a carboxylic acid or a salt thereof, a dialkylcarboxylic acid can be mentioned, and specific examples thereof include 11-ethoxyhepta. Hydroxy fatty acid chlorides, such as compounds in which the hydroxy moiety of hydroxy fatty acids such as sodium decanecarboxylate and sodium 2-ethoxypentacarboxylate is alkoxylated and the fatty acid moiety is sodiumated, and the amino group of amino acids such as sarcosine and glycine are alkoxylated And compounds obtained by reacting carboxylic acid in the amino acid part with sodium, and compounds obtained by reacting fatty acid chloride with the amino group of arginic acid.

Specific examples of the anionic surfactant in which the hydrophilic group is a carboxylic acid or a salt thereof include the following anionic surfactants.

The blending ratio of the anionic surfactant represented by the general formula (1) is preferably 1% by mass or more, more preferably 5% by mass or more. If the hydrophilicity is too high, the liquid tends to be held. From the viewpoint of impairing dryness, it is preferably 20% by mass or less, more preferably 13% by mass or less. The blending ratio of the anionic surfactant represented by the general formula (1) is preferably 1% by mass or more and 20% by mass or less, and more preferably 5% by mass or more and 13% by mass or less.

The content ratio (the former: the latter) of the polyorganosiloxane and the anionic surfactant represented by the general formula (1) in the fiber treatment agent is preferably 1: 3 to 4: 1 in terms of mass ratio. The ratio is preferably 1: 2 to 3: 1.

Furthermore, the fiber treatment agent uses an anionic surfactant or a cationic surfactant in addition to a spreadable component, a hydrophilic component, an alkyl phosphate ester, and an anionic surfactant. Can do.

Examples of anionic surfactants include alkyl phosphate sodium salt, alkyl ether phosphate sodium salt, dialkyl phosphate sodium salt, dialkyl sulfosuccinate sodium salt, alkylbenzene sulfonate sodium salt, alkyl sulfonate sodium salt, alkyl sulfate sodium salt, secondary Examples include alkyl sulfate sodium salt (all alkyls preferably have 6 to 22 carbon atoms, particularly preferably 8 to 22 carbon atoms). These may use other alkali metal salts such as potassium salts in place of sodium salts.

Examples of the cationic surfactant include alkyl (or alkenyl) trimethyl ammonium halide, dialkyl (or alkenyl) dimethyl ammonium halide, alkyl (or alkenyl) pyridinium halide, and these compounds have 6 or more carbon atoms. Those having 18 or less alkyl groups or alkenyl groups are preferred. Examples of the halogen in the halide compound include chlorine and bromine.

The fiber treatment agent may further contain a treatment agent such as an anti-sticking agent such as modified silicone, a fiber colorant, or a lubricant.

As a method for attaching the fiber treatment agent to the surface of the constituent fibers 11, various known methods can be employed without any particular limitation. For example, application by spraying, application by a slot coater, application by roll transfer, immersion in a fiber treatment agent, and the like can be mentioned. These treatments may be performed on the fibers before being made into a web, or after the fibers are made into a web by various methods. However, it is necessary to perform the treatment before the stretching treatment described later. The fiber having the fiber treatment agent attached to the surface is dried at a temperature sufficiently lower than the melting point of the polyethylene resin (for example, 120 ° C. or less) by, for example, a hot air blowing type dryer.

The non-woven fabric of the present invention (first invention) includes a fusing step of heat-sealing intersections of constituent fibers of a fiber web including a high elongation fiber to which a fiber treating agent is applied, at the fusing portion, and the fusing After the step, the nonwoven fabric is produced by a method for producing a nonwoven fabric comprising a drawing step of drawing the fused fiber web in one direction. One embodiment of the method for producing a nonwoven fabric of the present invention (first invention) will be described with reference to FIG. 4 taking the preferred method for producing the nonwoven fabric 1A as an example. FIG. 4 schematically shows a preferable manufacturing apparatus 100 used in the method for manufacturing the nonwoven fabric 1A. The manufacturing apparatus 100 is suitably used for manufacturing an air-through nonwoven fabric. The manufacturing apparatus 100 includes a web forming unit 200, a hot air processing unit 300, and an extending unit 400 in this order from the upstream side to the downstream side of the manufacturing process.

The web forming unit 200 is provided with a web forming apparatus 201 as shown in FIG. A card machine is used as the web forming apparatus 201. As a card machine, the thing normally used in the technical field of an absorbent article can be used without a restriction | limiting in particular. Depending on the specific use of the nonwoven fabric 1A, another web manufacturing apparatus, such as an airlaid apparatus, may be used instead of the card machine.

The hot air processing unit 300 includes a hood 301 as shown in FIG. Inside the hood 301, hot air can be blown by an air-through method. The hot air processing unit 300 includes an endless conveyor belt 302 made of a breathable net. The conveyor belt 302 circulates in the hood 301. The conveyor belt 302 is made of a resin such as polyethylene terephthalate or a metal.

The temperature of the hot air blown in the hood 301 and the heat treatment time are preferably adjusted so that the intersections of the high elongation fibers included in the constituent fibers 11 of the fiber web 10 are heat-sealed. Specifically, the temperature of the hot air is preferably adjusted to a temperature that is 0 ° C. to 30 ° C. higher than the melting point of the resin having the lowest melting point among the constituent fibers 11 of the fiber web 10. The heat treatment time is preferably adjusted to 1 to 5 seconds depending on the temperature of the hot air. Further, from the viewpoint of encouraging further entanglement between the constituent fibers 11, the wind speed of the hot air is preferably about 0.3 m / sec to 1.5 m / sec. Further, the conveying speed is preferably about 5 m / min to 100 m / min.

As shown in FIGS. 4 and 5, the extending portion 400 includes a pair of concave and convex rolls 401 and 402 that can be engaged with each other. The pair of concave and convex rolls 401 and 402 are formed so as to be heatable, and are formed by alternately arranging large-diameter convex portions 403 and 404 and small-diameter concave portions (not shown) in the roll axis direction. The uneven rolls 401 and 402 may or may not be heated, but the heating temperature when heating the uneven rolls 401 and 402 makes it easy to stretch the high elongation fibers included in the constituent fibers 11 of the fiber sheet 1a described later. From the viewpoint, it is preferable to be not less than the glass transition point of the resin having the highest glass transition point in the high elongation fiber and not more than the melting point of the resin having the lowest melting point in the high elongation fiber. More preferably, the temperature is 10 ° C. higher than the glass transition point of the fiber and 10 ° C. lower than the melting point, more preferably 20 ° C. higher than the glass transition point of the fiber and 20 ° C. lower than the melting point. It is. For example, when a fiber having a core / sheath structure of PET (core) having a glass transition point of 67 ° C. and a melting point of 258 ° C./PE (sheath) having a glass transition point of −20 ° C. and a melting point of 135 ° C. is used as the fiber. The temperature is preferably 67 ° C. or higher and 135 ° C. or lower, more preferably 77 ° C. or higher and 125 ° C. or lower, still more preferably 87 ° C. or higher and 115 ° C. or lower.

In the manufacturing apparatus 100, as shown in FIG. 6, the interval (pitch) between the large-diameter convex portions 403, 403 adjacent to each other in the roll axis direction of the uneven roll 401 and the roll axis direction of the uneven roll 402 are adjacent to each other. The spacing (pitch) between the large-diameter convex portions 404 and 404 is the same spacing (pitch) w, and the spacing (pitch) w is such that the high elongation fibers included in the constituent fibers 11 of the fiber sheet 1a are successfully used in the stretching apparatus. From the viewpoint of extending and extending the previously described change point from the small-diameter portion to the large-diameter portion adjacent to the fused portion and improving the touch, it is preferably 1 mm or more, particularly preferably 1.5 mm or more. And, it is preferably 10 mm or less, particularly preferably 8 mm or less, specifically, preferably 1 mm or more and 10 mm or less, particularly preferably 1.5 mm or more and 8 mm or less. A. From the same viewpoint, as shown in FIG. 6, the pushing amount t of the pair of concavo-convex rolls 401 and 402 (the distance between the apex of the large-diameter convex portion 403 and the apex of the large-diameter convex portion 404 adjacent in the roll axis direction) is The thickness is preferably 1 mm or more, particularly preferably 1.2 mm or more, and preferably 3 mm or less, particularly preferably 2.5 mm or less, and specifically preferably 1 mm or more and 3 mm or less. Especially preferably, it is 1.2 mm or more and 2.5 mm or less. From the same viewpoint, the mechanical stretch ratio is preferably 1.5 times or more, particularly preferably 1.7 times or more, and preferably 3.0 times or less, particularly preferably 2.8. More specifically, it is preferably 1.5 times or more and 3.0 times or less, and particularly preferably 1.7 times or more and 2.8 times or less.

The manufacturing method of 1 A of nonwoven fabrics using the manufacturing apparatus 100 which has the above structure is demonstrated.
First, as shown in FIG. 4, a web forming apparatus 201, which is a card machine, uses, as a raw material, short fiber-like constituent fibers 11 having high elongation fibers to which a fiber treating agent has already been applied. To form the fiber web 10 (web forming step). The fiber web 10 manufactured by the web forming apparatus 201 is in a state where the constituent fibers 11 are loosely entangled with each other, and has not yet achieved shape retention as a sheet.

Next, as shown in FIG. 4, the fiber sheet 1a is formed by thermally fusing the intersections of the constituent fibers 11 of the fiber web 10 including the high elongation fibers at the fusion part 12 (fusing step). Specifically, the fiber web 10 is conveyed onto the conveyor belt 302, and hot air is blown in an air-through manner while passing through the hood 301 by the hot air processing unit 300. When hot air is thus blown by the air-through method, the constituent fibers 11 of the fiber web 10 are further entangled, and at the same time, the intersection of the entangled fibers is thermally fused (see FIG. 7 (a)) to form a sheet. A fiber sheet 1a having a shape-retaining property is manufactured.

Next, as shown in FIG. 4, the fused fiber web 1a is stretched in one direction (stretching step). Specifically, the fused fiber web 1a having a shape retaining property as a sheet is conveyed between a pair of concave and convex rolls 401 and 402, as shown in FIGS. 7 (a) to 7 (c). In addition, the fiber web 1a is stretched, and a large fiber diameter is sandwiched between two small- diameter portions 16 and 16 having a small fiber diameter in one constituent fiber 11 between adjacent fusion portions 12 and 12. The large diameter portion 17 is formed, and the change point 18 from the small diameter portion 16 to the large diameter portion 17 is set to 1/3 of the interval T between the fusion portions 12, 12 adjacent to the fusion portion 12. Form within the range. Specifically, as shown in FIG. 7A, the fiber sheet 1a in which the intersections of the constituent fibers 11 are thermally fused at the fusion part 12 is conveyed between a pair of concave and convex rolls 401 and 402. Then, the fiber web 1a is stretched in the orthogonal direction (CD, roll axis direction) orthogonal to the machine direction (MD, flow direction). When the fiber sheet 1a is stretched in the orthogonal direction (CD, roll axis direction), the adjacent fused portions 12, 12 fixing the constituent fibers 11 shown in FIG. Is actively stretched in the orthogonal direction (CD, roll axis direction). In particular, as shown in FIG. 7B, local contraction is likely to occur first in the vicinity of each fusion part 12 that fixes the constituent fibers 11, and 1 between the adjacent fusion parts 12, 12. With respect to the constituent fiber 11, two small- diameter portions 16, 16 are formed at both ends, and a portion sandwiched between the two small- diameter portions 16, 16 becomes a large-diameter portion 17. A large-diameter portion 17 sandwiched between 16 is formed. In this way, local contraction is likely to occur in the vicinity of each fusion part 12, so that the change point 18 from the small diameter part 16 to the large diameter part 17 is adjacent to the fusion part 12 adjacent to the fusion part 12. It is formed within a range of 1/3 of the interval T between the twelve.

Then, with respect to one constituent fiber 11 between some adjacent fused portions 12 and 12, as shown in FIG. 7 (c), in a state where there is a room for expansion (extension margin), It is stretched in the orthogonal direction (CD, roll axis direction), the large diameter portion 17 between the adjacent fused portions 12, 12 is stretched, and the small diameter portion 16 is formed in the large diameter portion 17. Become.

When the region between the adjacent fused portions 12 and 12 in one constituent fiber 11 is positively stretched, the spreadable component of the fiber treatment agent attached to the surface of the constituent fiber 11 is a low temperature. Is excellent in fluidity, so that it flows along with the elongation of the fiber and is maintained attached to the surface of the small diameter portion 16. On the other hand, among the fiber treatment agent attached to the surface of the constituent fiber 11, components other than the spreadable component are stretched when the region between the adjacent fused portions 12, 12 is actively stretched. As a result, it cannot flow, and the state of adhering to the surface of the small diameter portion 16 cannot be maintained. Therefore, the composition ratio of the attached fiber treatment agent varies between the surface of the small diameter portion 16 and the surface of the large diameter portion 17 formed by stretching the region between the adjacent fusion portions 12 and 12. To do. Specifically, only a spreadable component easily adheres to the surface of the small diameter portion 16, while a fiber treatment agent containing a spreadable component and a hydrophilic component is formed on the surface of the large diameter portion 17. It comes to adhere. Therefore, the hydrophilicity of the small diameter portion 16 tends to be smaller than the hydrophilicity of the large diameter portion 17. In particular, when the above-described polyorganosiloxane is used as a spreadable component, since the polyorganosiloxane itself is hydrophobic, the hydrophilicity of the small diameter portion 16 becomes smaller than the hydrophilicity of the large diameter portion 17. easy.

As described above, according to the method for manufacturing the nonwoven fabric 1A using the manufacturing apparatus 100, the nonwoven fabric 1A including the constituent fibers 11 shown in FIG. 3 and having a smaller hydrophilicity of the small diameter portion 16 than that of the large diameter portion 17 is obtained. It can be manufactured continuously and efficiently. As shown in FIG. 4, the manufactured nonwoven fabric 1 </ b> A is once wound up and stored in the form of a roll, and then is unwound from the roll and used. Alternatively, processing is performed in the subsequent process line of the manufacturing apparatus 100 for the nonwoven fabric 1A, and the target product is continuously manufactured.

As shown in FIG. 3, the nonwoven fabric 1 </ b> A manufactured as described above pays attention to one constituent fiber 11 among the constituent fibers 11, and the small diameter portion 16 adjacent to the fusion portion 12 to the large diameter portion 17. Since the change point 18 is arranged within a range of ３ of the interval T between the adjacent fused portions 12, 12 from the fused portion 12, it is soft and good in terms of touch. In particular, if a plurality of small-diameter portions 16 are formed between the adjacent fused portions 12 and 12 while paying attention to one constituent fiber 11, the touch is further improved. From the viewpoint of easily exhibiting such an effect, the constituent fibers 11 are preferably made of only high elongation fibers.

If elastic fibers are contained in the constituent fibers 11, the nonwoven fabric is stretched while being contracted. Therefore, even if the manufacturing method of the nonwoven fabric 1A and the mechanical stretch ratio are the same, the fiber diameter hardly changes. Therefore, the change point 18 which is a part where the fiber diameter changes extremely is difficult when the elastic fiber is contained in the constituent fiber 11, and the part which changes gradually from the small diameter part 16 to the large diameter part 17 continuously. Is easily formed. The continuously and gradually changing portion formed in this way is not necessarily stretched locally near the fusion point because it contains elastic fibers, and is observed randomly rather than near the fusion point. Become so. In addition, it is preferable that the constituent fibers 11 do not include elastic fibers from the viewpoint of further improving the touch.

Further, the nonwoven fabric 1A includes the constituent fibers 11 in which the hydrophilicity of the small diameter portion 16 is smaller than the hydrophilicity of the large diameter portion 17. Accordingly, since the portion having a reduced hydrophilicity (small diameter portion 16) is dispersed on the surface of the nonwoven fabric 1A, the nonwoven fabric 1A has less liquid residue on the surface and improves the dry touch property, and the small diameter portion 16 reduces the interfiber distance. Spreads and liquid permeability improves.

Further, the nonwoven fabric 1A is a nonwoven fabric having a concavo-convex structure, and the fiber density of the side region 13c is smaller than the fiber density of the top region 13a and the fiber density of the bottom region 13b. Therefore, since the interfiber distance of the side region 13c is wider than the interfiber distance of the top region 13a and the bottom region 13b, the air permeability and liquid permeability are improved as the whole nonwoven fabric 1A. Furthermore, when the fiber density of the side region 13c is formed to be the smallest, the ridge portion 13 can easily follow the movement of the wearer's skin, and good skin contact can be realized.

Further, the nonwoven fabric 1A is a nonwoven fabric having a concavo-convex structure, and the number of change points 18 of one constituent fiber 11 constituting the side region 13c is changed by the one constituent fiber 11 constituting the top region 13a. More than the number of the change points 18 which the number of the points 18 and the one component fiber 11 which comprises the bottom region 13b have are formed. For this reason, since the portion having a reduced hydrophilicity (small diameter portion 16) is dispersed in the side region 13c, the liquid residue on the surface is further reduced and the dry touch property is further improved. Spreading liquid permeability is improved.

Next, the present invention (second invention) will be described below based on the preferred embodiment with reference to the drawings.
FIG. 8 is a perspective view of a nonwoven fabric 1B (hereinafter also referred to as “nonwoven fabric 1B”) which is an embodiment of the present invention (second invention). FIG. 9 is a schematic diagram showing a cross section in the thickness direction of the nonwoven fabric 1B shown in FIG. FIG. 10 is an enlarged schematic view of the constituent fibers 11 of the nonwoven fabric 1B shown in FIG. As shown in FIG. 8, the nonwoven fabric 1 </ b> B is a nonwoven fabric provided with a plurality of fusion portions 12 (see FIG. 10) formed by heat-sealing the intersections of the constituent fibers 11. And in this embodiment, as shown in FIG. 8, the nonwoven fabric 1B is a nonwoven fabric having a concavo-convex structure in which streaky ridges 13 and ridges 14 extending in one direction (X direction) are alternately arranged. is there. Specifically, as shown in FIG. 9, the nonwoven fabric 1B is adjacent to a plurality of ridges 13 in which the cross-sectional shapes of the front and back surfaces a and b are both convex upward in the thickness direction (Z direction). It has the concave line part 14 located between the convex line parts 13 and 13 which fit. The concave stripe part 14 has a concave shape in which the cross-sectional shapes of the front and back surfaces a and b are both upward in the thickness direction (Z direction) of the nonwoven fabric. In other words, as for the concave strip part 14, the cross-sectional shape of front and back both surfaces a and b has comprised the convex shape toward the downward direction of the thickness direction (Z direction) of a nonwoven fabric. And the some protruding item | line part 13 is continuously extended in one direction (X direction) of the nonwoven fabric 1B, respectively, and the several groove part 14 is also groove shape extended continuously in the one direction X of the nonwoven fabric 1B. I am doing. The ridges 13 and the ridges 14 are parallel to each other and are alternately arranged in a direction (Y direction) orthogonal to the one direction (X direction).

In addition, the nonwoven fabric 1B has the top part area | region 13a, the bottom part area | region 13b, and the side part area | region 13c located between these 13a, 13b in the cross sectional view of the nonwoven fabric 1B, as shown in FIG. And the top part of the protruding item | line part 13 is formed from the top part area | region 13a, and the bottom part of the grooved part 14 is formed from the bottom part area | region 13b. The top region 13a, the bottom region 13b, and the side region 13c extend continuously in one direction (X direction) of the nonwoven fabric 1B. As shown in FIG. 9, the top region 13a, the bottom region 13b, and the side region 13c are cross-sectional views of the nonwoven fabric 1B, and the thickness in the Z direction of the nonwoven fabric 1B is equally divided into three, and the upper portion in the thickness direction (Z direction). Are divided into a top region 13a, a central region in the thickness direction (Z direction) as a side region 13c, and a lower region in the thickness direction (Z direction) as a bottom region 13b. The said division is measured by the following method.

[Method of dividing top region 13a, bottom region 13b, and side region 13c]
Using a feather razor (part number FAS-10, manufactured by Feather Safety Razor Co., Ltd.), the nonwoven fabric 1B was cut in the Y direction and measured with a scanning electron microscope (JCM-5100 (trade name) manufactured by JEOL Ltd.). The area to be expanded is enlarged to a size that can be measured (10 to 100 times), the thickness of the nonwoven fabric 1B is divided into three equal parts, and the upper part in the thickness direction (Z direction) is the top region 13a. The central portion in the thickness direction (Z direction) is distinguished as a side region 13c, and the lower portion in the thickness direction (Z direction) is distinguished as a bottom region 13b.
When analyzing from a commercially available diaper or the like, a cold spray is sprayed on the target diaper or the like to solidify the hot melt adhesive. Then, each material is carefully peeled off to obtain a target nonwoven fabric, which is cut and measured as described above.

As will be described later, the nonwoven fabric 1B is manufactured by performing uneven processing on the fiber sheet 1a using a pair of uneven rolls 401 and 402 meshing with each other. The one direction (X direction) of the nonwoven fabric 1B described above is the same direction as the machine direction (MD, flow direction) when the nonwoven fabric 1B is manufactured by performing uneven processing on the fiber sheet 1a. The direction (Y direction) orthogonal to the direction (X direction) is the same direction as the orthogonal direction (CD, roll axis direction) orthogonal to the machine direction (MD, flow direction).

The constituent fibers 11 of the nonwoven fabric 1B include high elongation fibers. Here, the high elongation fiber included in the constituent fiber 11 means not only a fiber having a high elongation at the raw material fiber stage, but also a fiber having a high elongation at the stage of the manufactured nonwoven fabric 1B. As the “high elongation fiber”, excluding stretchable fibers that have elasticity (elastomer) and expand and contract, for example, as described in paragraph [0033] of JP 2010-168715, melt spinning is performed at a low speed to form a composite After obtaining the fiber, the heat-extensible fiber, which is obtained by changing the crystal state of the resin by heating and / or crimping without stretching, or polypropylene or polyethylene Fibers manufactured using relatively low spinning speeds using a resin such as polyethylene, polypropylene-polypropylene copolymers with low crystallinity, or fibers manufactured by dry blending polyethylene into polypropylene and spinning, etc. Is mentioned. Among these fibers, the high elongation fiber is preferably a core-sheath type composite fiber having heat-fusibility. The core-sheath type composite fiber may be a concentric core-sheath type, an eccentric core-sheath type, a side-by-side type, or a deformed type, but is preferably a concentric core-sheath type. Whatever form the fiber takes, from the viewpoint of producing a nonwoven fabric that is soft and soft to the touch, the fineness of the high elongation fiber may be 1.0 dtex or more at the raw material stage. Preferably, it is 2.0 dtex or more, more preferably 10.0 dtex or less, more preferably 8.0 dtex or less, specifically, 1.0 dtex or more and 10.0 dtex or less. Preferably, it is 2.0 dtex or more and 8.0 dtex or less.

The constituent fiber 11 of the nonwoven fabric 1B may be configured to include other fibers in addition to the high elongation fiber, but is preferably composed only of inelastic fibers, and is composed only of high elongation fibers. More preferably. Other fibers include, for example, a non-heat-extensible core-sheath-type heat-fusible composite fiber containing two components having different melting points, or a fiber that does not inherently have heat-fusibility ( Examples thereof include natural fibers such as cotton and pulp, rayon and acetate fibers). When the nonwoven fabric 1B0 includes other fibers in addition to the high elongation fibers, the proportion of the high elongation fibers in the nonwoven fabric 1B0 is preferably 50% by mass or more, and more preferably 80% by mass or more. And preferably 100% by mass or less, more preferably 100% by mass or less, specifically preferably 50% by mass or more and 100% by mass or less, and more preferably 80% by mass. % Or more and 100% by mass or less is preferable.

The heat-extensible fiber, which is an example of a high-stretch fiber, is a composite fiber that has been subjected to an unstretched or weakly stretched treatment at the raw material stage. For example, a first resin component that constitutes a core portion and a sheath portion And a second resin component containing a polyethylene resin, the first resin component having a higher melting point than the second resin component. A 1st resin component is a component which expresses the heat | fever extensibility of this fiber, and a 2nd resin component is a component which expresses heat-fusibility. The melting points of the first resin component and the second resin component were determined by thermal analysis of a finely cut fiber sample (sample weight 2 mg) using a differential scanning calorimeter (DSC6200 manufactured by Seiko Instruments Inc.) at a heating rate of 10 ° C./min. The melting peak temperature of each resin is measured and defined by the melting peak temperature. When the melting point of the second resin component cannot be clearly measured by this method, the resin is defined as “resin having no melting point”. In this case, the temperature at which the second resin component is fused to such an extent that the strength of the fusion point of the fiber can be measured is used as the temperature at which the molecular flow of the second resin component begins, and this is used instead of the melting point.

As above-mentioned, as a 2nd resin component which comprises a sheath part, the polyethylene resin is included. Examples of the polyethylene resin include low density polyethylene (LDPE), high density polyethylene (HDPE), and linear low density polyethylene (LLDPE). In particular, a high density polyethylene having a density of 0.935 g / cm ³ or more and 0.965 g / cm ³ or less is preferable. The second resin component constituting the sheath is preferably a polyethylene resin alone, but other resins can also be blended. Other resins to be blended include polypropylene resin, ethylene-vinyl acetate copolymer (EVA), ethylene-vinyl alcohol copolymer (EVOH), and the like. However, as for the 2nd resin component which comprises a sheath part, it is preferable that 50 mass% or more in the resin component of a sheath part is 70 to 100 mass% especially polyethylene resin. The polyethylene resin preferably has a crystallite size of 10 nm or more and 20 nm or less, and more preferably 11.5 nm or more and 18 nm or less.

As the first resin component constituting the core portion, a resin component having a melting point higher than that of the polyethylene resin that is a constituent resin of the sheath portion can be used without any particular limitation. Examples of the resin component constituting the core include polyolefin resins such as polypropylene (PP) (excluding polyethylene resin), polyester resins such as polyethylene terephthalate (PET), and polybutylene terephthalate (PBT). Furthermore, polyamide-based polymers, copolymers having two or more resin components, and the like can also be used. A plurality of types of resins can be blended and used. In this case, the melting point of the core is the melting point of the resin having the highest melting point. Since the nonwoven fabric can be easily manufactured, the difference between the melting point of the first resin component constituting the core part and the melting point of the second resin component constituting the sheath part (the former-the latter) is 20 ° C. or higher. It is preferable that it is 150 degrees C or less.

The preferred orientation index of the first resin component in the thermally stretchable fiber, which is an example of a high elongation fiber, is naturally different depending on the resin used. For example, when the first resin component is a polypropylene resin, the orientation index is 60% or less. More preferably, it is 40% or less, More preferably, it is 25% or less. When the first resin component is polyester, the orientation index is preferably 25% or less, more preferably 20% or less, and still more preferably 10% or less. On the other hand, the second resin component preferably has an orientation index of 5% or more, more preferably 15% or more, and still more preferably 30% or more. The orientation index is an index of the degree of orientation of the polymer chain of the resin constituting the fiber.

The orientation index of the first resin component and the second resin component is determined by the method described in paragraphs [0027] to [0029] of JP 2010-168715 A. A method for achieving the orientation index as described above for each resin component in the heat-extensible fiber is described in paragraphs [0033] to [0036] of Japanese Patent Application Laid-Open No. 2010-168715.

Further, the elongation of the high elongation fiber is preferably 100% or more at the raw material stage, more preferably 200% or more, still more preferably 250% or more, and 800% or less. It is preferably 500% or less, more preferably 400% or less, specifically preferably 100% or more and 800% or less, more preferably 200% or more and 500% or less, Preferably they are 250% or more and 400% or less. By using a high elongation fiber having an elongation in this range, the fiber is successfully stretched in a stretching apparatus, and a change point 18 from a small diameter portion 16 to a large diameter portion 17 described later becomes a fusion portion 12. Adjacent and good touch.

The elongation of the high elongation fiber conforms to JISL-1015, and the measurement is based on the measurement environment temperature and humidity of 20 ± 2 ° C, 65 ± 2% RH, the tensile tester gripping distance of 20mm, and the tensile speed of 20mm / min. And In addition, when collecting fibers from an already manufactured non-woven fabric and measuring the elongation, when the gripping interval cannot be 20 mm, that is, when the length of the fiber to be measured is less than 20 mm, the gripping interval is set. Measure by setting to 10 mm or 5 mm.

The ratio of the first resin component to the second resin component (mass ratio, the former: latter) in the high elongation fiber is 10:90 to 90:10, particularly 20:80 to 80:20, especially in the raw material stage. It is preferably 50:50 to 70:30. As the fiber length of the high elongation fiber, one having an appropriate length is used according to the method for producing the nonwoven fabric. For example, when the nonwoven fabric is manufactured by the card method as described later, the fiber length is preferably about 30 to 70 mm.

The fiber diameter of the high elongation fiber is appropriately selected according to the specific use of the nonwoven fabric at the raw material stage. When a nonwoven fabric is used as a constituent member of an absorbent article such as a surface sheet of an absorbent article, it is preferable to use one having a thickness of 10 μm or more, particularly preferably 15 μm or more, and one having a thickness of 35 μm or less. It is preferable to use a material having a thickness of 30 μm or less, and specifically, a material having a thickness of 10 μm to 35 μm, particularly 15 μm to 30 μm is preferable. The fiber diameter is measured by the following method.

[Measurement of fiber diameter]
The fiber diameter (μm) is measured by using a scanning electron microscope (JCM-5100 manufactured by JEOL Ltd.) and observing the cross section of the fiber at 200 to 800 times. The cross section of the fiber is obtained by cutting the fiber using a feather razor (product number FAS-10, manufactured by Feather Safety Razor Co., Ltd.). For each extracted fiber, the fiber diameter when approximated to a circle is measured at five locations, and the average value of the five measured values is taken as the fiber diameter.

In the raw material stage, in the case of using a heat-extensible fiber, which is an example of a high elongation fiber, in addition to the above-described heat-extensible fiber, Japanese Patent No. 4131852, Japanese Patent Application Laid-Open No. 2005-350836, Japanese Patent Application Laid-Open No. 2007-2007 The fibers described in JP-A-303035, JP-A 2007-204899, JP-A 2007-204901, JP-A 2007-204902, and the like can also be used.

As shown in FIG. 10, the nonwoven fabric of the present invention (second invention) pays attention to one constituent fiber 11 among the constituent fibers 11 of the nonwoven fabric 1B, and the constituent fibers 11 are adjacent to the fused portion 12. , 12 has a large-diameter portion 17 having a large fiber diameter sandwiched between two small- diameter portions 16, 16 having a small fiber diameter. Specifically, as shown in FIG. 10, focusing on one constituent fiber 11 of the constituent fibers 11 of the nonwoven fabric 1B, a fusion formed by heat-sealing the intersection with the other constituent fibers 11 is performed. A small diameter portion 16 having a small fiber diameter extends from the landing portion 12 with substantially the same fiber diameter. Then, paying attention to the single constituent fiber 11, the large-diameter portion 17 having a fiber diameter larger than that of the small-diameter portion 16 between the small- diameter portions 16 and 16 extending from the adjacent fusion portions 12 and 12. Are extended with substantially the same fiber diameter. More specifically, the nonwoven fabric 1B pays attention to one constituent fiber 11, and from one fused portion 12 of adjacent fused portions 12, 12, toward the other fused portion 12, It has constituent fibers 11 arranged in the order of a small diameter portion 16 on the side of the attachment portion 12, one large diameter portion 17, and a small diameter portion 16 on the side of the other fusion portion 12. Further, as shown in FIG. 10, the nonwoven fabric 1 </ b> B focuses on one constituent fiber 11 among the constituent fibers 11 of the nonwoven fabric 1 </ b> B, and has a large diameter portion 17 between the adjacent fusion portions 12, 12. The constituent fiber 11 is provided with a plurality (two in the nonwoven fabric 1B). More specifically, the nonwoven fabric 1B pays attention to one constituent fiber 11, and from one fused portion 12 of adjacent fused portions 12, 12, toward the other fused portion 12, Constituent fibers arranged in the order of the small-diameter portion 16 on the bonding portion 12 side, the first large-diameter portion 17, the small-diameter portion 16, the second large-diameter portion 17, and the small-diameter portion 16 on the other fused portion 12 side. 11. As described above, the low-rigidity small-diameter portion 16 is adjacent to the fused portion 12 where the stiffness of the nonwoven fabric 1B is increased, thereby improving the flexibility of the nonwoven fabric 1B and improving the touch. Moreover, the softness | flexibility of the nonwoven fabric 1B improves further and the touch becomes further better, so that there are many small diameter parts 16 with a plurality of large diameter parts 17, in other words, the constituent fiber 11 has low rigidity. The nonwoven fabric 1B pays attention to one constituent fiber 11, and preferably has one large-diameter portion 17 between the adjacent fused portions 12, 12, from the viewpoint of improving the touch and reducing the strength of the nonwoven fabric. More, more preferably 1 or more, and preferably 5 or less, more preferably 3 or less, specifically preferably 1 or more and 5 or less, more preferably 1 or more and 3 Has less than one.

The ratio (L ₁₆ / L ₁₇ ) of the fiber diameter (diameter L ₁₆ ) of the small diameter part 16 to the fiber diameter (diameter L ₁₇ ) of the large diameter part 17 is preferably 0.5 or more, more preferably 0.55 or more. And preferably it is 0.8 or less, More preferably, it is 0.7 or less, Specifically, Preferably it is 0.5 or more and 0.8 or less, More preferably, it is 0.55 or more and 0.7 or less. Specifically, the fiber diameter (diameter L ₁₆ ) of the small-diameter portion 16 is preferably 5 μm or more, more preferably 6.5 μm or more, particularly preferably 7.5 μm or more from the viewpoint of improving the touch and reducing the strength of the nonwoven fabric. And preferably 28 μm or less, more preferably 20 μm or less, particularly preferably 16 μm or less, specifically preferably 5 μm or more and 28 μm or less, more preferably 6.5 μm or more and 20 μm or less, particularly preferably 7. It is 5 μm or more and 16 μm or less. The fiber diameter (diameter L ₁₇ ) of the large diameter portion 17 is preferably 10 μm or more, more preferably 13 μm or more, particularly preferably 15 μm or more, preferably 35 μm or less, more preferably 25 μm or less, from the viewpoint of improving the touch. The thickness is particularly preferably 20 μm or less, specifically, preferably 10 μm or more and 35 μm or less, more preferably 13 μm or more and 25 μm or less, and particularly preferably 15 μm or more and 20 μm or less.
The fiber diameters (the diameters L ₁₆ and L ₁₇ ) of the small diameter part 16 and the large diameter part 17 are measured in the same manner as the fiber diameter measurement described above.

Further, as shown in FIG. 10, the nonwoven fabric of the present invention (second invention) pays attention to one constituent fiber 11 among the constituent fibers 11 of the nonwoven fabric 1 </ b> B, and a small-diameter portion 16 adjacent to the fused portion 12. The change point 18 from the large diameter portion 17 to the large diameter portion 17 is arranged within a range of ３ of the interval T between the fusion portions 12 and 12 adjacent to the fusion portion 12. Here, the change point 18 of the nonwoven fabric of the present invention (second invention) is a large diameter portion 17 extending from a small diameter portion 16 extending with a small fiber diameter and a fiber diameter larger than that of the small diameter portion 16. It does not include a part that continuously changes gradually or a part that continuously changes over a plurality of stages, and means a part where the fiber diameter changes extremely. In the case where the single constituent fiber 11 is a core-sheath type composite fiber, the change point 18 of the nonwoven fabric of the present invention (second invention) is the first resin component constituting the core part and the sheath part. It does not include a state in which the fiber diameter is changed by peeling with the second resin component to be configured, and means a portion where the fiber diameter is changed by stretching.

In addition, the fact that the change point 18 is arranged within a range of 1/3 of the interval T between the adjacent fused portions 12 and 12 from the fused portion 12 means that the constituent fibers 11 of the nonwoven fabric 1B are randomly extracted. As shown in FIG. 10, using JCM-5100 (trade name) manufactured by JEOL Ltd. as a scanning electron microscope, the constituent fibers 11 are bonded between adjacent fusion portions 12 and 12. Enlarge it so that it can be observed (100 to 300 times). Next, the interval T between the centers of the adjacent fused portions 12 and 12 is divided into three equal parts, and the region AT on the side of one fused portion 12, the region BT on the side of the other fused portion 12, and the center region CT Break down. This means that the change point 18 is arranged in the area AT or the area BT. Further, the non-woven fabric 1B in which the change point 18 is disposed within a range of 1/3 of the interval T between the adjacent fused portions 12 and 12 from the fused portion 12 means that the constituent fibers 11 of the non-woven fabric 1B are 20 When extracted randomly, the constituent fiber 11 in which the change point 18 is arranged in the region AT or the region BT means a nonwoven fabric in which at least one of the 20 constituent fibers 11 is present. Specifically, from the viewpoint of improving touch, it is preferably 1 or more, more preferably 5 or more, and particularly preferably 10 or more.

As will be described later, the nonwoven fabric 1B of the present embodiment extends not only the side region 13c but also the top region 13a that is the top of the ridge 13 and the bottom region 13b that is the bottom of the concave 14 by stretching, The fiber density of the whole nonwoven fabric is lower than the raw material nonwoven fabric before stretching. Thereby, the liquid permeability and air permeability of the whole nonwoven fabric 1B are improving. Among the top region 13a, the bottom region 13b, and the side region 13c, the side region 13c is particularly easy to be stretched and the fiber density is likely to decrease. In the side region 13c, liquid permeability and air permeability are particularly good. It has improved.

The nonwoven fabric 1B of the present embodiment is formed such that the fiber density of the side region 13c is smaller than the fiber density of the top region 13a that is the top of the protruding portion 13 and the fiber density of the bottom region 13b that is the bottom of the recessed portion 14. Has been. Here, the fiber density is the mass of the fiber per unit volume of the nonwoven fabric 1B. High fiber density means that the amount of fibers present per unit volume of the nonwoven fabric 1B is large and the distance between fibers is small. Low fiber density means that the amount of fibers present per unit volume of the nonwoven fabric 1B is small and the distance between fibers is large. In addition, the site | part with a high fiber density has high capillary force, and the site | part with a low fiber density has low capillary force.

As shown in FIG. 9, the nonwoven fabric 1 </ b> B is a cross-sectional view, and the nonwoven fabric 1 </ b> B is a fiber in a side region 13 c between the top portion (top region 13 a) of the ridge 13 and the bottom portion (bottom region 13 b) of the recess 14. The density is the smallest. Therefore, in the side region 13c, the amount of fibers existing per unit volume of the nonwoven fabric 1B is the smallest, the interfiber distance is the largest, and the nonwoven fabric 1B as a whole has improved air permeability and liquid permeability. improves. Furthermore, when the fiber density of the side region 13c is formed to be the smallest, the ridge portion 13 can easily follow the movement of the wearer's skin, and good skin contact can be realized. In order to impart such a fiber density to the side region 13c, the nonwoven fabric 1B may be manufactured according to the manufacturing method described later.

The ratio (D ₁₅ / D ₁₃ , D ₁₅ / D ₁₄ ) of the fiber density (D ₁₅ ) of the side region 13c to the fiber density (D ₁₃ ) in the top region 13a or the fiber density (D ₁₄ ) in the bottom region 13b. ) Is preferably 0.15 or more, more preferably 0.2 or more, and preferably 0.9 or less, more preferably 0.8 or less, and specifically preferably 0.15 or more. 0.9 or less, more preferably 0.2 or more and 0.8 or less. The specific value of the fiber density of the nonwoven fabric 1B is such that the fiber density (D ₁₃ ) in the top region 13a is preferably 80 / mm ² or more, more preferably 90 / mm ² or more, and Preferably it is 200 / mm ² or less, more preferably 180 / mm ² or less, specifically, preferably 80 / mm ² or more and 200 / mm ² or less, more preferably 90 / mm ² or more. 180 pieces / mm ² or less. Also, the fiber density _{(D 14)} of the bottom area 13b, preferably 80 present / mm ² or more, more preferably 90 present / mm ² or more, and preferably 200 present / mm ² or less, more preferably 180 / mm ² or less, specifically, preferably 80 / mm ² or more and 200 / mm ² or less, more preferably 90 / mm ² or more and 180 / mm ² or less. The fiber density of the side region 13c _{(D 15)} is preferably 30 present / mm ² or more, more preferably 40 present / mm ² or more, and preferably 80 present / mm ² or less, more preferably 70 / mm ² or less, specifically, preferably 30 / mm ² or more and 80 / mm ² or less, more preferably 40 / mm ² or more and 70 / mm ² or less. The fiber density of the top region 13 a is measured at a position near the top of the ridge 13. The fiber density of the bottom region 13b is measured at a position near the bottom point of the concave strip portion 14. The method for measuring the fiber density is as follows.

[Measuring method of fiber density in top region 13a, bottom region 13b or side region 13c]
The nonwoven fabric was cut using a feather razor (part number FAS-10, manufactured by Feather Safety Razor Co., Ltd.), and the fiber density in the top area 13a was obtained by dividing the thickness of the cut surface of the nonwoven fabric into three equal parts in the Z direction. The vicinity of the apex of the ridge 13 which is the upper part is magnified using a scanning electron microscope (adjusted to a magnification capable of measuring 30 to 60 fiber cross-sections; 150 to 500 times), and per fixed area (0.5 mm) ² ) Count the number of cross-sections of the fibers cut by the cut surface. Next, it converts into the number of cross sections of the fiber per 1 mm < ² >, and makes this the fiber density in the top region 13a. The measurement is performed at three locations, and the average is the fiber density of the sample. Similarly, the fiber density in the bottom region 13b is obtained by measuring the vicinity of the bottom point of the concave portion 14 which is a lower portion when the thickness of the cut surface of the nonwoven fabric is equally divided into three in the Z direction. Similarly, the fiber density of the side region 13c is determined by measuring the central part when the thickness of the cut surface of the nonwoven fabric is equally divided into three in the Z direction. As a scanning electron microscope, JCM-5100 (trade name) manufactured by JEOL Ltd. is used.

Further, in the nonwoven fabric 1B of the present embodiment, the number of fibers having the change point 18 in the constituent fibers constituting the side region 13c is the number of fibers having the change point 18 in the constituent fibers constituting the top region 13a and the bottom region 13b. More are formed. Thereby, the top region 13a can easily follow the movement of the wearer's skin, and good skin contact can be realized. The side region 13c with respect to the number of fibers having the change point 18 in the constituent fibers constituting the top region 13a (N ₁₃ ) or the number of fibers having the change point 18 in the component fibers constituting the bottom region 13b (N ₁₄ ) The ratio (N ₁₅ / N ₁₃ , N ₁₅ / N ₁₄ ) of the number (N ₁₅ ) of fibers having the change point 18 in the constituent fibers constituting is preferably 2 or more, more preferably 5 or more, and preferably Is 20 or less, more preferably 20 or less. Specifically, it is preferably 2 or more and 20 or less, more preferably 5 or more and 20 or less. Moreover, regarding the specific value of the number of fibers having the change point 18 of the nonwoven fabric 1B, the number of fibers having the change point 18 (N ₁₃ ) in the constituent fibers constituting the top region 13a is preferably one or more, and further Preferably it is 5 or more, and preferably 15 or less, more preferably 15 or less, specifically, preferably 1 or more and 15 or less, more preferably 5 or more and 15 or less. . The number (N ₁₄ ) of fibers having the change point 18 in the constituent fibers constituting the bottom region 13b is preferably 1 or more, more preferably 5 or more, and preferably 15 or less, more preferably Is 15 or less, and specifically, preferably 1 or more and 15 or less, more preferably 5 or more and 15 or less. The number (N ₁₅ ) of fibers having the change point 18 in the constituent fibers constituting the side region 13c is preferably 5 or more, more preferably 10 or more, and preferably 20 or less, The number is preferably 20 or less, specifically, preferably 5 or more and 20 or less, and more preferably 10 or more and 20 or less. The method for measuring the number of fibers having the change point 18 is as follows.

[Measurement method of the number of fibers having the change point 18 in the constituent fibers constituting the top region 13a, the bottom region 13b, or the side region 13c]
As for the number of fibers having the change point 18 in the constituent fibers 11 constituting the top region 13a, scanning electrons are scanned around the apex of the ridge 13 which is the upper part when the thickness of the nonwoven fabric is equally divided into three in the Z direction. Using a microscope, magnified observation (adjusted to a magnification capable of measuring 30 to 60 fiber cross sections; 50 to 500 times), 20 constituent fibers 11 constituting the top region 13a were randomly extracted, and 20 constituent fibers 11 were extracted. The number of fibers having the change point 18 in the is counted. When there are one or more change points 18 between the fused portions, the number of fibers having the change points 18 is set, and when there are a plurality of change points 18, the number is also set to one. This is the number of fibers having the change point 18 in the constituent fibers constituting the top region 13a. The measurement is performed at three places, and the average is the number of fibers having the change point 18 in the constituent fibers constituting the top region 13a of the sample. Similarly, regarding the number of fibers having the change point 18 in the constituent fibers 11 constituting the bottom region 13b, the vicinity of the bottom point of the concave portion 14 which is a lower portion when the thickness of the nonwoven fabric is equally divided into three in the Z direction. Determine by measuring. Similarly, the number of fibers having the change point 18 in the constituent fibers 11 constituting the side region 13c is obtained by measuring the central portion when the thickness of the nonwoven fabric is equally divided into three in the Z direction. As a scanning electron microscope, JCM-5100 (trade name) manufactured by JEOL Ltd. is used.

The nonwoven fabric 1B of this embodiment is, for example, a disposable diaper having a top sheet disposed on the skin facing surface side, a back sheet disposed on the non-skin facing surface side, and an absorber interposed between the both sheets. Or it is used for absorbent articles, such as a sanitary napkin. In particular, among the constituent members of the absorbent article, the top sheet is formed from the nonwoven fabric 1B, or a liquid-permeable sublayer disposed between the top sheet and the absorbent body is formed from the nonwoven fabric 1B. Can be. If the said surface sheet is formed with the nonwoven fabric 1B, since the nonwoven fabric 1B is a nonwoven fabric of uneven structure, a contact area rate with skin will become low and it will become difficult to rub further. Moreover, when the said surface sheet or the said sublayer is formed with the nonwoven fabric 1B, since the nonwoven fabric 1B is a nonwoven fabric of a concavo-convex structure, compression resistance improves, a feeling of cushion improves, and the return of body fluid can be prevented.

The thickness of the nonwoven fabric 1B, the entire thickness of when the side view of the nonwoven fabric 1B and sheet thickness T _S, the local thickness of the nonwoven fabric 1B curved in its irregularities and the layer thickness T _L. Sheet thickness _{T S} is may be adjusted as appropriate depending on the application, when used as a topsheet or sublayer of the absorbent article is preferably at least 0.5 mm, more preferably at least 1 mm, and preferably 7mm or less, 5 mm or less More specifically, 0.5 mm or more and 7 mm or less are preferable, and 1 mm or more and 5 mm or less are more preferable. By setting it as this range, the bodily fluid absorption speed | velocity at the time of use is quick, the liquid return from an absorber is suppressed, and also moderate cushioning property is realizable.

The layer thickness _TL may be different at each site in the nonwoven fabric 1B, and may be appropriately adjusted depending on the application. When used as a surface sheet or sublayer of an absorbent article, the layer thickness T _L1 of the top region 13a is preferably 0.1 mm or more, more preferably 0.2 mm or more, and 3.0 mm or less. Is preferably 2.0 mm or less, specifically 0.1 mm or more and 3.0 mm or less, more preferably 0.2 mm or more and 2.0 mm or less. The layer thickness T _L2 of the bottom region 13b is preferably 0.1 mm or more, more preferably 0.2 mm or more, and preferably 3.0 mm or less, more preferably 2.0 mm or less. Is preferably from 0.1 mm to 3.0 mm, more preferably from 0.2 mm to 2.0 mm. The layer thickness T _L3 of the side region 13c is preferably 0.1 mm or more, more preferably 0.2 mm or more, and preferably 3.0 mm or less, more preferably 2.0 mm or less. Specifically, it is preferably from 0.1 mm to 3.0 mm, and more preferably from 0.2 mm to 2.0 mm. By setting it as this range, the bodily fluid absorption speed | velocity at the time of use is quick, the liquid return from an absorber is suppressed, and also moderate cushioning property is realizable.

The sheet thickness T _S and the layer thickness T _L are measured by the following methods.
Method of measuring the thickness of the sheet _{T S} is in a state of applying a load of 0.05kPa nonwoven 1B, measured using a thickness gauge. A laser displacement meter manufactured by OMRON Corporation is used for the thickness measuring instrument. Thickness is measured at 10 points, and the average value is calculated as the thickness.
The layer thickness _TL is measured by enlarging the cross section of the sheet with a Keyence digital microscope VHX-900 by about 20 times to measure the thickness of each layer.

When the nonwoven fabric 1B is viewed in plan, the pitch between the top regions 13a adjacent to each other in the Y direction may be appropriately adjusted depending on the application, and is preferably 1 mm or more when used as a surface sheet or sublayer of an absorbent article. 5 mm or more is more preferable, 15 mm or less is preferable, 10 mm or less is more preferable, specifically, 1 mm or more and 15 mm or less is preferable, and 1.5 mm or more and 10 mm or less is more preferable.

The basis weight of the nonwoven fabric 1B depends on the specific use of the nonwoven fabric 1B, but when used as a surface sheet or sublayer of an absorbent article, the average value of the entire sheet is preferably 15 g / m ² or more, and 20 g / m ^2. m ² or more is more preferable, and 50 g / m ² or less is preferable, 40 g / m ² or less is more preferable, specifically, 15 g / m ² or more and 50 g / m ² or less is preferable, and 20 g / m ² or more and 40 g. / M ² or less is more preferable.

Further, a small amount of fiber treatment agent such as fiber colorant, antistatic property agent, lubricant, hydrophilic agent may be attached to the surface of the constituent fiber 11 of the nonwoven fabric 1B at the raw material stage.

As a method for attaching the fiber treatment agent to the surface of the constituent fibers 11, various known methods can be employed without any particular limitation. For example, application by spraying, application by a slot coater, application by roll transfer, immersion in a fiber treatment agent, and the like can be mentioned. These treatments may be performed on the fibers before being made into a web, or after the fibers are made into a web by various methods. However, it is necessary to perform the process before the hot air blowing process described later. The fiber having the fiber treatment agent attached to the surface is dried at a temperature sufficiently lower than the melting point of the polyethylene resin (for example, 120 ° C. or less) by, for example, a hot air blowing type dryer.

The non-woven fabric of the present invention (second invention) comprises a fusing step of forming a fiber sheet by thermally fusing intersections of constituent fibers of a fiber web containing high elongation fibers at a fusing portion, and the fiber sheet. It is manufactured by the manufacturing method of a nonwoven fabric provided with the extending process extended | stretched to one direction. One embodiment of the method for producing a nonwoven fabric of the present invention (second invention) will be described with reference to FIG. 11 by taking the above-described preferred method for producing nonwoven fabric 1B as an example. FIG. 11 schematically shows a preferable manufacturing apparatus 100B used in the method for manufacturing the nonwoven fabric 1B. The manufacturing apparatus 100B is suitably used for manufacturing an air-through nonwoven fabric. The manufacturing apparatus 100B includes a web forming unit 200, a hot air processing unit 300, and an extending unit 400 in this order from the upstream side to the downstream side of the manufacturing process.

The web forming unit 200 is provided with a web forming apparatus 201 as shown in FIG. A card machine is used as the web forming apparatus 201. As a card machine, the thing normally used in the technical field of an absorbent article can be used without a restriction | limiting in particular. Depending on the specific use of the nonwoven fabric 1B, another web manufacturing apparatus, such as an airlaid apparatus, can be used instead of the card machine.

The hot air processing unit 300 includes a hood 301 as shown in FIG. Inside the hood 301, hot air can be blown by an air-through method. The hot air processing unit 300 includes an endless conveyor belt 302 made of a breathable net. The conveyor belt 302 circulates in the hood 301. The conveyor belt 302 is made of a resin such as polyethylene terephthalate or a metal.

The temperature of the hot air blown in the hood 301 and the heat treatment time are preferably adjusted so that the intersections of the high elongation fibers included in the constituent fibers 11 of the fiber web 10 are heat-sealed. Specifically, the temperature of the hot air is preferably adjusted to a temperature that is 0 ° C. to 30 ° C. higher than the melting point of the resin having the lowest melting point among the constituent fibers 11 of the fiber web 10. The heat treatment time is preferably adjusted to 1 to 5 seconds depending on the temperature of the hot air. Further, from the viewpoint of encouraging further entanglement between the constituent fibers 11, the wind speed of the hot air is preferably about 0.3 m / sec to 1.5 m / sec. Further, the conveying speed is preferably about 5 m / min to 100 m / min.

As shown in FIGS. 11 and 12, the stretching unit 400 includes a pair of concave and convex rolls 401 and 402 that can be engaged with each other. The pair of concave and convex rolls 401 and 402 are formed so as to be heatable, and are formed by alternately arranging large-diameter convex portions 403 and 404 and small-diameter concave portions (not shown) in the roll axis direction. The uneven rolls 401 and 402 may or may not be heated, but the heating temperature when heating the uneven rolls 401 and 402 makes it easy to stretch the high elongation fibers included in the constituent fibers 11 of the fiber sheet 1a described later. From the viewpoint, it is preferable to be not less than the glass transition point of the resin having the highest glass transition point in the high elongation fiber and not more than the melting point of the resin having the lowest melting point in the high elongation fiber. More preferably, the temperature is 10 ° C. higher than the glass transition point of the fiber and 10 ° C. lower than the melting point, more preferably 20 ° C. higher than the glass transition point of the fiber and 20 ° C. lower than the melting point. It is. For example, when a fiber having a core / sheath structure of PET (core) having a glass transition point of 67 ° C. and a melting point of 258 ° C./PE (sheath) having a glass transition point of −20 ° C. and a melting point of 135 ° C. is used as the fiber. The temperature is preferably 67 ° C. or higher and 135 ° C. or lower, more preferably 77 ° C. or higher and 125 ° C. or lower, still more preferably 87 ° C. or higher and 115 ° C. or lower.

Further, in the manufacturing apparatus 100B, as shown in FIG. 13, the interval (pitch) between the large-diameter convex portions 403, 403 adjacent to each other in the roll axis direction of the uneven roll 401 and the roll axis direction of the uneven roll 402 are adjacent to each other. The spacing (pitch) between the large-diameter convex portions 404 and 404 is the same spacing (pitch) w, and the spacing (pitch) w is such that the high elongation fibers included in the constituent fibers 11 of the fiber sheet 1a are successfully used in the stretching apparatus. From the viewpoint of extending and extending the previously described change point from the small-diameter portion to the large-diameter portion adjacent to the fused portion and improving the touch, it is preferably 1 mm or more, particularly preferably 1.5 mm or more. And preferably 10 mm or less, particularly preferably 8 mm or less, specifically preferably 1 mm or more and 10 mm or less, particularly preferably 1.5 mm or more and 8 mm. It is below. From the same viewpoint, as shown in FIG. 13, the pressing amount t of the pair of concave and convex rolls 401 and 402 (the distance between the vertex of the large-diameter convex portion 403 and the vertex of the large-diameter convex portion 404 adjacent in the roll axis direction) is The thickness is preferably 1 mm or more, particularly preferably 1.2 mm or more, and preferably 3 mm or less, particularly preferably 2.5 mm or less, and specifically preferably 1 mm or more and 3 mm or less. Especially preferably, it is 1.2 mm or more and 2.5 mm or less. From the same viewpoint, the mechanical stretch ratio is preferably 1.5 times or more, particularly preferably 1.7 times or more, and preferably 3.0 times or less, particularly preferably 2.8. More specifically, it is preferably 1.5 times or more and 3.0 times or less, and particularly preferably 1.7 times or more and 2.8 times or less.

The manufacturing method of the nonwoven fabric 1B using the manufacturing apparatus 100B which has the above structure is demonstrated.
First, as shown in FIG. 11, the web forming unit 200 uses the short fiber-shaped constituent fiber 11 having high elongation fibers as a raw material, and the fiber web 10 is formed by the web forming apparatus 201 which is a card machine ( Web forming step). The fiber web 10 manufactured by the web forming apparatus 201 is in a state where the constituent fibers 11 are loosely entangled with each other, and has not yet achieved shape retention as a sheet.

Next, as shown in FIG. 11, the fiber sheet 1 a is formed by heat-sealing the intersections of the constituent fibers 11 of the fiber web 10 including high elongation fibers at the fusion part 12 (fusing step). Specifically, the fiber web 10 is conveyed onto the conveyor belt 302, and hot air is blown in an air-through manner while passing through the hood 301 by the hot air processing unit 300. When hot air is thus blown by the air-through method, the constituent fibers 11 of the fiber web 10 are further entangled, and at the same time, the intersection of the entangled fibers is thermally fused (see FIG. 14 (a)) to form a sheet. A fiber sheet 1a having a shape-retaining property is manufactured.

Next, as shown in FIG. 11, the fused fiber web 1a is stretched in one direction (stretching step). Specifically, the fused fiber web 1a having a shape-retaining property as a sheet is conveyed between a pair of concave and convex rolls 401 and 402, as shown in FIGS. 14 (a) to 14 (c). In addition, the fiber web 1a is stretched, and a large fiber diameter is sandwiched between two small- diameter portions 16 and 16 having a small fiber diameter in one constituent fiber 11 between adjacent fusion portions 12 and 12. The large diameter portion 17 is formed, and the change point 18 from the small diameter portion 16 to the large diameter portion 17 is set to 1/3 of the interval T between the fusion portions 12, 12 adjacent to the fusion portion 12. Form within the range. Specifically, as shown in FIG. 14A, the fiber sheet 1a in which the intersections of the constituent fibers 11 are heat-sealed at the fusion part 12 is conveyed between a pair of concave and convex rolls 401 and 402. Then, the fiber web 1a is stretched in the orthogonal direction (CD, roll axis direction) orthogonal to the machine direction (MD, flow direction). When the fiber sheet 1a is stretched in the orthogonal direction (CD, roll axis direction), the adjacent fused portions 12, 12 fixing the constituent fibers 11 shown in FIG. Is actively stretched in the orthogonal direction (CD, roll axis direction). In particular, as shown in FIG. 14B, local contraction is likely to occur first in the vicinity of each fusion part 12 that fixes the constituent fibers 11, and 1 between the adjacent fusion parts 12, 12. With respect to the constituent fiber 11, two small- diameter portions 16, 16 are formed at both ends, and a portion sandwiched between the two small- diameter portions 16, 16 becomes a large-diameter portion 17. A large-diameter portion 17 sandwiched between 16 is formed. In this way, local contraction is likely to occur in the vicinity of each fusion part 12, so that the change point 18 from the small diameter part 16 to the large diameter part 17 is adjacent to the fusion part 12 adjacent to the fusion part 12. It is formed within a range of 1/3 of the interval T between the twelve.

Then, with respect to one constituent fiber 11 between some adjacent fused portions 12, 12, as shown in FIG. 14 (c), in a state in which there is left a room for expansion (extension margin), It is stretched in the orthogonal direction (CD, roll axis direction), the large diameter portion 17 between the adjacent fused portions 12, 12 is stretched, and the small diameter portion 16 is formed in the large diameter portion 17. Become.

As mentioned above, according to the manufacturing method of the nonwoven fabric 1B using the manufacturing apparatus 100B, the nonwoven fabric 1B provided with the structural fiber 11 shown in FIG. 10 can be manufactured continuously and efficiently. As shown in FIG. 11, the manufactured nonwoven fabric 1B is once wound up and stored in the form of a roll, and then is unwound from the roll and used. Or in the post-process line of the manufacturing apparatus 100B of the nonwoven fabric 1B, a process is given and the target product is manufactured continuously.

As shown in FIG. 10, the nonwoven fabric 1 </ b> B manufactured as described above pays attention to one constituent fiber 11 among the constituent fibers 11, and the small diameter portion 16 to the large diameter portion 17 adjacent to the fused portion 12. Since the change point 18 is arranged within a range of ３ of the interval T between the adjacent fused portions 12, 12 from the fused portion 12, it is soft and good in terms of touch. In particular, if a plurality of small-diameter portions 16 are formed between the adjacent fused portions 12 and 12 while paying attention to one constituent fiber 11, the touch is further improved. From the viewpoint of easily exhibiting such an effect, the constituent fibers 11 are preferably made of only high elongation fibers.

If elastic fibers are contained in the constituent fibers 11, the nonwoven fabric is stretched while being contracted. Therefore, even if the manufacturing method of the nonwoven fabric 1B and the mechanical stretch ratio are the same, the fiber diameter hardly changes. Therefore, the change point 18 which is a part where the fiber diameter changes extremely is difficult when the elastic fiber is contained in the constituent fiber 11, and the part which changes gradually from the small diameter part 16 to the large diameter part 17 continuously. Is easily formed. The continuously and gradually changing portion formed in this way is not necessarily stretched locally near the fusion point because it contains elastic fibers, and is observed randomly rather than near the fusion point. Become so. In addition, it is preferable that the constituent fibers 11 do not include elastic fibers from the viewpoint of further improving the touch.

Moreover, the nonwoven fabric 1B is a nonwoven fabric with a concavo-convex structure, and the fiber density of the side region 13c is smaller than the fiber density of the top region 13a and the fiber density of the bottom region 13b. Therefore, since the interfiber distance of the side region 13c is wider than the interfiber distance of the top region 13a and the bottom region 13b, the air permeability and liquid permeability are improved as the entire nonwoven fabric 1B. Furthermore, when the fiber density of the side region 13c is formed to be the smallest, the ridge portion 13 can easily follow the movement of the wearer's skin, and good skin contact can be realized.

Moreover, the nonwoven fabric 1B is a nonwoven fabric with a concavo-convex structure, and the number of change points 18 included in one constituent fiber 11 constituting the side region 13c is changed by one constituent fiber 11 constituting the top region 13a. More than the number of the change points 18 which the number of the points 18 and the one component fiber 11 which comprises the bottom region 13b have are formed. Therefore, it becomes easy for the ridge 13 to follow the movement of the wearer's skin, and there is an effect of realizing good skin contact.

The nonwoven fabric of this invention (1st invention) is not restrict | limited at all to the nonwoven fabric 1A of the above-mentioned this embodiment, It can change suitably.
Moreover, the manufacturing method of the nonwoven fabric of this invention (1st invention) is not restrict | limited to the manufacturing method of the above-mentioned embodiment at all, and can be changed suitably.

For example, as shown in FIG. 1, the nonwoven fabric 1 </ b> A is a nonwoven fabric having a concavo-convex structure in which streaky ridges 13 and ridges 14 extending in one direction (X direction) are alternately arranged. It may be a non-woven fabric having a three-dimensional concavo-convex structure that is arranged at regular intervals so as to form rows intermittently in each direction of the X direction and the Y direction and forms a staggered arrangement pattern. Further, from the viewpoint of improving the shape retention of the concavo-convex structure, the concavo-convex structure non-woven fabric may be disposed on another non-woven fabric and bonded, or the concavo-convex structure non-woven fabric may be embossed. Moreover, the nonwoven fabric 1A may be a nonwoven fabric having a flat structure instead of the uneven structure.

Moreover, according to the manufacturing method of 1 A of nonwoven fabrics using the manufacturing apparatus 100 mentioned above, although the fiber web 1a is extended | stretched in the orthogonal direction (CD, roll axial direction) orthogonal to a machine direction (MD, flow direction). The film may be stretched in the machine direction (MD, flow direction). Thus, when extending | stretching to a machine direction (MD, a flow direction), the convex part with which a pair of uneven | corrugated roll 401,402 which meshes | engages mutually should just be distribute | arranged to the surrounding surface so that a rotating shaft direction may be followed.

Moreover, according to the manufacturing method of 1 A of nonwoven fabrics using the manufacturing apparatus 100 mentioned above, between the web formation process using the web formation part 200 and the melt | fusion process using the hot air processing part 300, or the hot air processing part 300 is used. You may provide the application | coating process which uses a fiber treatment agent application part between a melt | fusion process and the extending | stretching process using the extending part 400. FIG. The coating process may be performed before the stretching process using the stretching unit 400.

The nonwoven fabric of this invention (2nd invention) is not restrict | limited to the nonwoven fabric 1B of this embodiment mentioned above at all, It can change suitably.
Moreover, the manufacturing method of the nonwoven fabric of this invention (2nd invention) is not restrict | limited at all to the manufacturing method of the above-mentioned embodiment, It can change suitably.

For example, as shown in FIG. 8, the nonwoven fabric 1B is a nonwoven fabric having a concavo-convex structure in which streak-like convex portions 13 and concave portions 14 extending in one direction (X direction) are alternately arranged. It may be a non-woven fabric having a three-dimensional concavo-convex structure that is arranged at regular intervals so as to form rows intermittently in each direction of the X direction and the Y direction and forms a staggered arrangement pattern. Further, from the viewpoint of improving the shape retention of the concavo-convex structure, the concavo-convex structure non-woven fabric may be disposed on another non-woven fabric and bonded, or the concavo-convex structure non-woven fabric may be embossed. Moreover, the nonwoven fabric 1B may be a nonwoven fabric with a flat structure instead of the uneven structure.

Moreover, according to the manufacturing method of the nonwoven fabric 1B using the manufacturing apparatus 100B mentioned above, although the fiber web 1a is extended | stretched in the orthogonal direction (CD, roll axial direction) orthogonal to a machine direction (MD, flow direction). The film may be stretched in the machine direction (MD, flow direction). Thus, when extending | stretching to a machine direction (MD, a flow direction), the convex part with which a pair of uneven | corrugated roll 401,402 which meshes | engages mutually should just be distribute | arranged to the surrounding surface so that a rotating shaft direction may be followed.

The description omitted in one embodiment described above and the requirements of only one embodiment can be applied to other embodiments as appropriate, and the requirements in each embodiment can be appropriately changed between the embodiments. Can be substituted.

The following non-woven fabrics are further disclosed with respect to the embodiment described above.

<1>
A non-woven fabric provided with a plurality of fusion parts formed by heat-sealing the intersections of the constituent fibers,
The constituent fibers include high elongation fibers,
Paying attention to one of the constituent fibers, the constituent fiber has a large diameter portion having a large fiber diameter sandwiched between two small diameter portions having a small fiber diameter between the adjacent fused portions. And
A nonwoven fabric in which the hydrophilicity of the small diameter portion is smaller than the hydrophilicity of the large diameter portion.

<2>
The difference between the contact angle of the small diameter portion and the contact angle of the large diameter portion (the former-the latter) is 1 degree or more, more preferably 5 degrees or more, more preferably 10 degrees or more, preferably 25 degrees or less, More preferably, it is 20 degrees or less, more preferably 15 degrees or less, specifically, preferably 1 degree or more and 25 degrees or less, more preferably 5 degrees or more and 20 degrees or less, more preferably 10 degrees or more and 15 degrees or less. The nonwoven fabric as described in <1>.
<3>
The contact angle of the small diameter portion is preferably 60 degrees or more, more preferably 70 degrees or more, more preferably 80 degrees or more, preferably 100 degrees or less, more preferably 95 degrees or less, and more preferably 90 degrees or less. Specifically, the nonwoven fabric according to <1> or <2>, which is preferably 60 ° to 100 °, more preferably 70 ° to 95 °, and still more preferably 80 ° to 90 °.
<4>
The contact angle of the large-diameter portion is preferably 55 degrees or more, more preferably 60 degrees or more, more preferably 65 degrees or more, preferably 90 degrees or less, more preferably 85 degrees or less, more preferably 80 degrees or less. Specifically, any one of the above items <1> to <3>, preferably 55 ° to 90 °, more preferably 60 ° to 85 °, and still more preferably 65 ° to 80 °. The nonwoven fabric described in 1.
<5>
The ratio (L ₁₆ / L ₁₇ ) of the fiber diameter (diameter L ₁₆ ) of the small diameter portion to the fiber diameter (diameter L ₁₇ ) of the large diameter portion is preferably 0.5 or more, more preferably 0.55 or more, And it is preferably 0.8 or less, more preferably 0.7 or less, specifically, preferably 0.5 or more and 0.8 or less, more preferably 0.55 or more and 0.7 or less. The nonwoven fabric according to any one of 1> to <4>.
<6>
The changing point from the small diameter part adjacent to the fusion part to the large diameter part is arranged within a range of 1/3 of the interval between the fusion parts adjacent to the fusion part,
The non-woven fabric is a non-woven fabric having a concavo-convex structure in which streaky ridges and ridges extending in one direction are alternately arranged,
The non-woven fabric has a top region, a bottom region, and a side region located therebetween,
The top of the ridge is formed from the top region, the bottom of the ridge is formed from the bottom region,
The side region is configured with respect to the number (N ₁₃ ) of fibers having change points in the constituent fibers constituting the top region or the number of fibers (N ₁₄ ) having change points in the constituent fibers constituting the bottom region. The ratio (N ₁₅ / N ₁₃ , N ₁₅ / N ₁₄ ) of the number of fibers (N ₁₅ ) having a change point in the constituent fibers is preferably 2 or more, more preferably 5 or more, and preferably 20 or less. The nonwoven fabric according to any one of <1> to <5>, more preferably 20 or less, specifically 2 or more and 20 or less, preferably 5 or more and 20 or less.
<7>
A fiber treating agent is attached to the constituent fibers,
The nonwoven fabric according to any one of <1> to <6>, wherein the fiber treatment agent contains a spreadable component.
<8>
The absorbent article according to <7>, wherein the spreadable component is a component that, when attached to a fiber surface, easily spreads on the fiber surface at a low temperature and has excellent fluidity at a low temperature.
<9>
The non-woven fabric according to <7> or <8>, wherein the spreadable component is polyorganosiloxane.
<10>
The non-woven fabric according to <9>, wherein the polyorganosiloxane is selected from polydimethylsiloxane, polydiethylsiloxane, and polydipropylsiloxane.
<11>
The nonwoven fabric according to any one of <7> to <10>, wherein the fiber treatment agent further contains a hydrophilic component.

<12>
The hydrophilic component according to <11>, wherein the hydrophilic component uses a zwitterionic surfactant or a nonionic surfactant.
<13>
The zwitterionic surfactant is a betaine-type zwitterionic surfactant, preferably an alkyl (one having 30 to 30 carbon atoms) betaine, more preferably an alkyl betaine having 16 to 22 carbon atoms (eg stearyl). 12>.
<14>
The nonionic surfactant is glycerin fatty acid ester, poly (preferably n = 2 to 10) glycerin fatty acid ester, sorbitan fatty acid ester, polyhydric alcohol fatty acid ester (all preferably having 8 to 60 carbon atoms of fatty acid), Polyoxyalkylene (added mole number 2 to 20) alkyl (carbon number 8 to 22) amide, polyoxyalkylene (added mole number 2 to 20) alkyl (carbon number 8 to 22) ether, polyoxyalkylene-modified silicone, amino-modified The nonwoven fabric according to <12>, selected from silicones.
<15>
The nonwoven fabric according to any one of <7> to <14>, wherein the fiber treatment agent further contains a hydrophobic component.
<16>
The non-woven fabric according to <15>, wherein the hydrophobic component is selected from an alkyl phosphate ester, an anionic surfactant represented by the following general formula (1), and the like.

(Wherein Z represents an ester group, an amide group, an amine group, a polyoxyalkylene group, an ether group or a linear or branched alkyl chain having 1 to 12 carbon atoms, which may contain a double bond; R ₁ and R ₂ each independently represents an ester group, an amide group, a polyoxyalkylene group, an ether group or a linear or branched alkyl group having 2 to 16 carbon atoms, which may contain a double bond. , X represents —SO ₃ M, —OSO ₃ M or —COOM, and M represents H, Na, K, Mg, Ca or ammonium.)
<17>
The nonwoven fabric according to <16>, wherein the alkyl phosphate ester is a completely neutralized or partially neutralized salt of a mono- or dialkyl phosphate ester having 16 to 18 carbon chains.
<18>
The nonwoven fabric according to any one of the above items <1> to <17>, wherein the constituent fibers are composed of only high elongation fibers.

<19>
High-stretch fibers, excluding stretchable fibers that have elasticity (elastomer) and expand and contract, are subjected to heat treatment and / or crimping treatment without drawing treatment after melt spinning at low speed to obtain a composite fiber. Heat-extensible fibers whose length changes by changing the crystalline state of the resin by heating, or fibers produced under relatively low spinning speed using a resin such as polypropylene or polyethylene, or The non-woven fabric according to the above <18>, which is selected from polyethylene-polypropylene copolymer having a low crystallinity, or fibers produced by dry blending and spinning polyethylene in polypropylene.
<20>
The non-woven fabric according to <18> or <19>, wherein the ratio of the high elongation fiber in the nonwoven fabric is 50% by mass or more, preferably 80% by mass or more, and particularly preferably 100% by mass.
<21>
The high elongation fiber means not only a fiber having a high elongation at the raw material fiber stage, but also a fiber having a high elongation at the stage of the produced nonwoven fabric. The nonwoven fabric of any one.
<22>
The elongation of the high elongation fiber is preferably 100% or more at the raw material stage, more preferably 200% or more, still more preferably 250% or more, and 800% or less. More preferably 500% or less, still more preferably 400% or less, specifically 100% to 800%, preferably 200% to 500%, more preferably 250% to 400%. The nonwoven fabric according to any one of the above items <18> to <21>.
<23>
The elongation of the high elongation fiber is 60% or more, preferably 70% or more, more preferably 80% or more, preferably 200% or less, at the nonwoven fabric stage. Preferably it is 150% or less, more preferably 120% or less, specifically 60% or more and 200% or less, more preferably 70% or more and 170% or less, and further preferably 80% or more and 150% or less. The nonwoven fabric according to any one of <18> to <22>.
<24>
The change point from the small diameter part adjacent to the fusion part to the large diameter part is arranged within a range of 1/3 of the interval between the fusion parts adjacent to the fusion part. The nonwoven fabric according to any one of> to <23>.
<25>
The nonwoven fabric according to any one of <1> to <24>, in which a plurality of the large-diameter portions are arranged between the adjacent fused portions, paying attention to one of the constituent fibers.
<26>
The non-woven fabric according to any one of <1> to <25>, wherein the non-woven fabric is a non-woven fabric having a concavo-convex structure in which streaky ridges and ridges extending in one direction are alternately arranged.
<27>
The non-woven fabric has a top region, a bottom region, and a side region located therebetween,
The top of the ridge is formed from the top region, the bottom of the ridge is formed from the bottom region,
The nonwoven fabric according to <26>, wherein the fiber density in the side region is smaller than the fiber density in the top region and the fiber density in the bottom region.
<28>
The non-woven fabric has a top region, a bottom region, and a side region located therebetween,
The top of the ridge is formed from the top region, the bottom of the ridge is formed from the bottom region,
The number of fibers having change points in the constituent fibers constituting the side region, the number of fibers having change points in the constituent fibers constituting the top region, and the change point in the constituent fibers constituting the bottom region The non-woven fabric according to <25> or <27>, which is more than the number of.
<29>
From the constituent fiber obtained by adhering the fiber treatment agent to the constituent fiber before the stretching treatment and drying the fiber web containing the constituent fiber at a temperature sufficiently lower than the melting point of the polyethylene resin (for example, 120 ° C. or less) The nonwoven fabric according to <7>, which is formed.
<30>
The nonwoven fabric according to any one of <1> to <29>, wherein the intersection between the constituent fibers is a joining point, and the joining point is the fusion part.
<31>
An absorbent article having a top sheet disposed on the skin facing surface side, a back sheet disposed on the non-skin facing surface side, and an absorbent body interposed between the both sheets,
The absorbent article, wherein the top sheet is formed of the nonwoven fabric according to any one of <1> to <30>.

<32>
A non-woven fabric provided with a plurality of fusion parts formed by heat-sealing the intersections of the constituent fibers,
The constituent fibers include high elongation fibers,
Paying attention to one of the constituent fibers, the constituent fiber has a large diameter portion having a large fiber diameter sandwiched between two small diameter portions having a small fiber diameter between the adjacent fused portions. And
The change point from the small diameter part adjacent to the fusion part to the large diameter part is arranged within a range of 1/3 of the interval between the fusion parts adjacent to the fusion part, The nonwoven fabric according to any one of 1> to <30>.

<33>
The fiber diameter (diameter L ₁₆ ) of the small diameter portion is preferably 5 μm or more, more preferably 6.5 μm or more, particularly preferably 7.5 μm or more, and preferably 28 μm or less, more preferably 20 μm or less, particularly Preferably it is 16 micrometers or less, Specifically, Preferably they are 5 micrometers or more and 28 micrometers or less, More preferably, they are 6.5 micrometers or more and 20 micrometers or less, Especially preferably, they are 7.5 micrometers or more and 16 micrometers or less, The nonwoven fabric as described in said <32>.
<34>
The fiber diameter (diameter L ₁₇ ) of the large diameter portion is preferably 10 μm or more, more preferably 13 μm or more, particularly preferably 15 μm or more, preferably 35 μm or less, more preferably 25 μm or less, particularly preferably 20 μm or less. Specifically, the nonwoven fabric according to any one of the above <32> or <32>, which is preferably 10 μm to 35 μm, more preferably 13 μm to 25 μm, and particularly preferably 15 μm to 20 μm.
<35>
The change point is the nonwoven fabric according to any one of <32> to <34>, wherein the fiber diameter is changed by stretching.
<36>
Any one of the above items <32> to <35>, wherein the nonwoven fabric has one or more, preferably 5 or more, more preferably 10 or more of the constituent fibers having the change point in the 20 constituent fibers. The nonwoven fabric described in 1.
<37>
The number (N ₁₃ ) of fibers having the change point in the constituent fibers constituting the top region is preferably 1 or more, more preferably 5 or more, and preferably 15 or less, more preferably 15 The absorbent article according to the above <6>, which is not more than the present, and specifically preferably not less than 1 and not more than 15 and more preferably not less than 5 and not more than 15.
<38>
The number (N ₁₄ ) of fibers having the change point in the constituent fibers constituting the bottom region is preferably 1 or more, more preferably 5 or more, and preferably 15 or less, more preferably 15 The non-woven fabric according to the above <6> or <37>, which is not more than this, specifically preferably not less than 1 and not more than 15 and more preferably not less than 5 and not more than 15.
<39>
The number (N ₁₅ ) of fibers having the change point in the constituent fibers constituting the side region is preferably 5 or more, more preferably 10 or more, and preferably 20 or less, more preferably It is 20 or less, specifically, preferably 5 or more and 20 or less, more preferably 10 or more and 20 or less, according to any one of the above <6>, <37> or <38> Non-woven fabric.

<40>
The non-woven fabric according to any one of <32> to <39>, wherein the constituent fibers are composed only of inelastic fibers.
<41>
The fineness of the high elongation fiber is preferably 1.0 dtex or more, more preferably 2.0 dtex or more, and preferably 10.0 dtex or less at the raw material stage, and 8.0 dtex or less. The non-woven fabric according to any one of the above <32> to <40>, more preferably 1.0 dtex or more and 10.0 dtex or less, and more preferably 2.0 dtex or more and 8.0 dtex or less. .
<42>
The nonwoven fabric according to any one of the above items <32> to <41>, in which a plurality of the large diameter portions are arranged between the adjacent fused portions by paying attention to one of the constituent fibers.
<43>
Paying attention to one of the constituent fibers, the above-mentioned <32> to-having the large-diameter portion of not less than 1 and not more than 5, preferably not less than 1 and not more than 3, between the adjacent fused portions. The nonwoven fabric according to any one of <42>.

<44>
The non-woven fabric according to any one of <32> to <43>, wherein the non-woven fabric is a non-woven fabric having a concavo-convex structure in which streaky ridges and recesses extending in one direction are alternately arranged.
<45>
The non-woven fabric has a top region, a bottom region, and a side region located therebetween,
The top of the ridge is formed from the top region, the bottom of the ridge is formed from the bottom region,
The nonwoven fabric according to <44>, wherein the fiber density in the side region is smaller than the fiber density in the top region and the fiber density in the bottom region.
<46>
The non-woven fabric is a non-woven fabric having a concavo-convex structure in which streaky ridges and ridges extending in one direction are alternately arranged,
The non-woven fabric has a top region, a bottom region, and a side region located therebetween,
The top of the ridge is formed from the top region, the bottom of the ridge is formed from the bottom region,
Ratio (D ₁₅ / D ₁₃ ) of fiber density (D ₁₅ ) of the wall portion between the bottom region and the fiber density (D ₁₃ ) in the top region or the fiber density (D ₁₄ ) in the bottom region , D ₁₅ / D ₁₄ ) is preferably 0.15 or more, more preferably 0.2 or more, and preferably 0.9 or less, more preferably 0.8 or less. Specifically, The nonwoven fabric according to any one of <32> to <45>, which is 0.15 or more and 0.9 or less, preferably 0.2 or more and 0.8 or less.
<47>
Fiber density at the top region _{(D 13)} is preferably 80 present / mm ² or more, more preferably 90 present / mm ² or more, and preferably 200 present / mm ² or less, more preferably 180 lines / Mm ² or less, specifically, 80 / mm ² or more and 200 / mm ² or less, preferably 90 / mm ² or more and 180 / mm ² or less, according to <46>.
<48>
Fiber density at the bottom region _{(D 14)} is preferably 80 present / mm ² or more, more preferably 90 present / mm ² or more, and preferably 200 present / mm ² or less, more preferably 180 lines / mm ² or less, specifically, 80 present / mm ² or more 200 present / mm ² or less, preferably 90 present / mm ² or more 180 lines / mm ² or less is the <46> or <47> The nonwoven fabric described.
<49>
The fiber density (D ₁₅ ) in the bottom region is preferably 30 fibers / mm ² or more, more preferably 40 fibers / mm ² or more, and preferably 80 fibers / mm ² or less, more preferably 70 fibers / mm ^2. and mm ^{2 or} less, specifically, 30 present / mm ² or more eighty / mm ² or less, either preferably at forty / mm ² or more 70 yarns / mm ² or less wherein the <46> - <48> Or the nonwoven fabric according to 1.
<50>
The number of fibers having change points in the constituent fibers constituting the side region, the number of fibers having change points in the constituent fibers constituting the top region, and the change point in the constituent fibers constituting the bottom region The nonwoven fabric according to any one of the above items <45> to <49>, which is more than the number of.

<51>
A fusion process in which the intersection of the constituent fibers of the fiber web including the high elongation fiber to which the fiber treatment agent is applied is thermally fused at the fusion part;
A non-woven fabric manufacturing method comprising a stretching step of stretching the fused fiber web in one direction after the fusing step,
In the stretching step, the fiber web is stretched, and the fiber having a large fiber diameter is sandwiched between two small-diameter portions having a small fiber diameter between one of the constituent fibers between the adjacent fused portions. A method for producing a nonwoven fabric, in which a diameter portion is formed and the hydrophilicity of the small diameter portion is made smaller than the hydrophilicity of the large diameter portion.

<52>
In the stretching step, the fiber sheet is stretched, and the fiber having a large fiber diameter is sandwiched between two small-diameter portions having a small fiber diameter in one constituent fiber between the adjacent fused portions. <51> wherein the diameter portion is formed, and the changing point from the small diameter portion to the large diameter portion is formed within a range of 1/3 of the interval between the fusion portions adjacent to the fusion portion. The manufacturing method of the nonwoven fabric as described in any one of.
<53>
The manufacturing apparatus used in the method for manufacturing the nonwoven fabric includes a stretching section,
The extending portion includes a pair of first concavo-convex rolls and second concavo-convex rolls that can be engaged with each other,
The interval (pitch) w between large-diameter convex portions adjacent to each other in the roll axis direction of the first concave-convex roll and the interval (pitch) w between large-diameter convex portions adjacent to each other in the roll axis direction of the second concave-convex roll are: It is preferably 1 mm or more, particularly preferably 1.5 mm or more, and preferably 10 mm or less, particularly preferably 8 mm or less, specifically 1 mm or more and 10 mm or less, preferably 1.5 mm or more. The manufacturing method of the nonwoven fabric as described in said <52> which is 8 mm or less.
<54>
The pushing amount t of the first concavo-convex roll and the second concavo-convex roll (the interval between the vertex of the large-diameter convex portion of the first concavo-convex roll adjacent to the roll axis direction and the vertex of the large-diameter convex portion of the second concavo-convex roll) is , Preferably 1 mm or more, particularly preferably 1.2 mm or more, and preferably 3 mm or less, particularly preferably 2.5 mm or less, specifically 1 mm or more and 3 mm or less, preferably 1 The method for producing a nonwoven fabric according to any one of <52> or <53>, which is 2 mm or more and 2.5 mm or less.

<55>
The mechanical stretching ratio of the first uneven roll and the second uneven roll is preferably 1.5 times or more, particularly preferably 1.7 times or more, and preferably 3.0 times or less, Particularly preferably 2.8 times or less, specifically 1.5 times or more and 3.0 times or less, preferably 1.7 times or more and 2.8 times or less, <52> to <54 > The manufacturing method of the nonwoven fabric any one of.
<56>
A nonwoven fabric produced by the production method according to any one of <51> to <55>.
<57>
An absorbent article having a top sheet disposed on the skin facing surface side, a back sheet disposed on the non-skin facing surface side, and an absorbent body interposed between the both sheets,
The absorbent article, wherein the top sheet is formed of the nonwoven fabric according to any one of <32> to <50>, <56>.

Hereinafter, the nonwoven fabric of the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited by the examples.

[Example 1A]
The nonwoven fabric of Example 1A of the form shown in FIG.1 and FIG.2 was manufactured using the manufacturing apparatus 100 shown in FIG. The constituent fibers supplied to the manufacturing apparatus 100 are shown in Table 1 below. The composition of the fiber treatment agent applied to the constituent fibers is as shown in Table 1. The fiber treatment agent contains polyorganosiloxane as a spreadable component, and is hydrophilic in addition to the spreadable component. And a hydrophobic component (alkyl phosphate ester, anionic surfactant). As shown in Table 1, the constituent fiber is a fiber made of only high elongation fiber and having no elasticity (elastomer). The high elongation fiber was a concentric core-sheath type composite fiber having a core part made of polyethylene terephthalate and a sheath part made of polyethylene. The elongation of the high elongation fiber was 350%. Moreover, regarding the manufacturing apparatus 100, the distance (pitch) between the large-diameter convex portions 404, 404 included in the pair of concave and convex rolls 401, 402 is 2.0 mm, and the pressing amount of the pair of concave and convex rolls 401, 402 is 1. 2 mm, and the mechanical draw ratio was 1.9 times. In addition, application | coating of the fiber treatment agent to a constituent fiber was before the extending process.

[Example 2A]
Regarding the manufacturing apparatus 100 in Example 1A, an example is obtained in the same manner as in Example 1A except that the pressing amount of the pair of concave and convex rolls 401 and 402 is changed to 1.4 mm and the mechanical stretch ratio is changed to 2.1 times. A 2A nonwoven fabric was produced.

Example 3A
Regarding the manufacturing apparatus 100 in Example 1A, the example was changed in the same manner as in Example 1A, except that the pushing amount of the pair of concave and convex rolls 401 and 402 was changed to 1.6 mm and the mechanical stretch ratio was changed to 2.3 times. A 3A nonwoven fabric was produced.

Example 4A
A nonwoven fabric of Example 4A was produced in the same manner as Example 1A except that the composition of the fiber treatment agent in Example 1A was changed as shown in Table 1.

[Example 5A]
The composition of the fiber treatment agent in Example 1A was changed as shown in Table 1. Moreover, regarding the manufacturing apparatus 100 in Example 1A, the pressing amount of the pair of concave and convex rolls 401 and 402 was changed to 1.4 mm, and the mechanical stretch ratio was changed to 2.1 times. Except for these, the nonwoven fabric of Example 5A was produced in the same manner as Example 1A.

[Example 6A]
The composition of the fiber treatment agent in Example 1A was changed as shown in Table 1. Moreover, regarding the manufacturing apparatus 100 in Example 1A, the pressing amount of the pair of concave and convex rolls 401 and 402 was changed to 1.6 mm, and the mechanical stretching ratio was changed to 2.3 times. A nonwoven fabric of Example 6A was produced in the same manner as Example 1A except for the above.

Example 7A
The fiber treatment agent in Example 1A was changed as shown in Table 1. The fiber treatment agent applied to the constituent fibers does not contain a spreadable component but contains a hydrophilic component. Other than that was carried out similarly to Example 1A, and manufactured the nonwoven fabric of Example 7A.

[Example 8A]
The composition of the fiber treatment agent in Example 1A was changed as shown in Table 1. Moreover, regarding the manufacturing apparatus 100 in Example 1A, the pressing amount of the pair of concave and convex rolls 401 and 402 was changed to 1.6 mm, and the mechanical stretching ratio was changed to 2.3 times. Otherwise, the nonwoven fabric of Example 8A was produced in the same manner as Example 1A.

Example 9A
The composition of the fiber treatment agent in Example 1A was changed as shown in Table 1. Moreover, regarding the manufacturing apparatus 100 in Example 1A, the pressing amount of the pair of concave and convex rolls 401 and 402 was changed to 1.6 mm. A nonwoven fabric of Example 9A was produced in the same manner as Example 1A except for the above.

[Comparative Example 1A]
The constituent fibers in Example 1A were changed as shown in Table 1. The fiber treatment agent applied to the constituent fibers does not contain a spreadable component but contains a hydrophilic component. Moreover, application | coating of the fiber treatment agent to a constituent fiber was performed after the extending process. Except for these, a nonwoven fabric of Comparative Example 1A was produced in the same manner as Example 1A.

<Evaluation>
Regarding the nonwoven fabrics of Examples 1A to 9A and Comparative Example 1A, the thickness was measured by the method described above, and the basis weight of the nonwoven fabric was calculated. The results are shown in Table 1 below. Moreover, the contact angle of the small diameter part 16 and the large diameter part 17 was measured by the method mentioned above. The results are shown in Table 1 below.
Further, with respect to the nonwoven fabrics of Examples 1A to 9A and Comparative Example 1A, the liquid remaining property, dry touch property, and touch were evaluated by the following methods. The results are shown in Table 1 below.

[Evaluation of liquid residue]
The absorber was taken out from the commercially available product name “Water Absorbing Safety for Safe Medium Weight (˜80 cc)” (made in 2014) of Kao Corporation, and the removed absorber was placed horizontally. A 200 mm × 100 mm rectangle in which the nonwoven fabrics of Examples 1A to 7A or Comparative Example 1A are arranged on this absorbent body, and a cylindrical portion (inner diameter 10 mm, height 40 mm) is further arranged on the nonwoven fabric. A shaped acrylic plate was placed. Under the condition that the pressure by the acrylic plate was 0.5 kPa, 20 g of artificial urine was collectively injected into the cylindrical portion at a rate of 5 g / sec. After 7 seconds, the acrylic plate was removed, a commercially available tissue paper 2PL product was folded three times, and an absorbent paper having a size of about 5 cm × about 12 cm was placed on the inlet, and pressure was applied at 0.5 kpa for 5 seconds. Thereafter, the pressure was removed, and the weight (g) of the tissue paper that absorbed the artificial urine was measured. The weight (g) of the tissue paper before absorption of artificial urine was subtracted from this weight, and the value was defined as the remaining liquid amount (mg) remaining on the nonwoven fabric. The smaller the value of the remaining liquid amount (mg), the higher the liquid remaining property, and the higher the evaluation.

The composition of artificial urine is as follows. 1.94% by mass of urea, 0.7954% by mass of sodium chloride, 0.11058% by mass of magnesium sulfate (septahydrate), 0.06208% by mass of calcium chloride (dihydrate), 0.19788% by mass of potassium sulfate , Polyoxyethylene lauryl ether 0.0035 mass% and ion-exchanged water (remaining amount).

[Evaluation of dry touch of nonwoven fabric]
The dry touch property of the nonwoven fabric was measured in accordance with the “153.0-02 REPEATED Liquid Strike-Through Time” method of EDANA (European Nonwoven Fabric Manufacturers Association) using a strike-through time measuring device Lister manufactured by Lenzing Technik. Liquid Strike-Through Time indicates the time (seconds) required for a predetermined amount of physiological saline to pass from the front surface to the back surface of the nonwoven fabric. Specifically, ten sheets of dedicated filter paper were placed on the pedestal of the testing machine, and a nonwoven fabric was placed thereon. Next, a strike-through plate having electrodes is placed on the non-woven fabric, and 10 ml of physiological saline (4.5 g of sodium chloride in 500 mL) is introduced from a liquid inlet connected to the strike-through plate, and then the power supply of the testing machine Put. The test machine measured the time (seconds) from the state in which the physiological saline touched the electrode until the physiological saline passed through the nonwoven fabric, the water level dropped, and the electrode was not in contact with the electrode. The measurement was performed three times, and the average value was defined as the liquid permeation time of the nonwoven fabric. The shorter the liquid permeation time, the less liquid remaining on the surface, indicating better dry touch properties.

[Evaluation of touch]
The touch of the nonwoven fabric was subjected to sensory evaluation by 10 adult women. Specifically, scoring was performed on the basis of the following score, and the average value of all the members in each nonwoven fabric was rounded to the nearest whole number.
5 points: The touch of the nonwoven fabric is very good.
4 points: The touch of the nonwoven fabric is good.
3 points: The feel of the nonwoven fabric is normal.
2 points: The touch of the nonwoven fabric is bad.
1 point: The touch of the nonwoven fabric is very bad.

According to the results shown in Table 1, it was found that the hydrophilicity of the small diameter portion 16 and the hydrophilicity of the large diameter portion 17 changed in the nonwoven fabrics of Examples 1A to 9A compared to the nonwoven fabric of Comparative Example 1A. Regarding the nonwoven fabrics of Examples 1A to 9A, the hydrophilicity of the small diameter portion 16 is smaller than the hydrophilicity of the large diameter portion 17. Further, it was found that the nonwoven fabrics of Examples 1A to 9A had less liquid residue on the surface and better dry touch properties than the nonwoven fabric of Comparative Example 1A. In addition, the nonwoven fabrics of Examples 1A to 9A were found to have the same or better nonwoven fabric feel in addition to the effect of better dry touch properties than the nonwoven fabric of Comparative Example 1A.

Hereinafter, the nonwoven fabric of the present invention (second invention) will be described in more detail with reference to examples. However, the scope of the present invention (second invention) is not limited in any way by such embodiments.

[Example 1B]
Using the manufacturing apparatus 100B shown in FIG. 11, the nonwoven fabric of Example 1B having the configuration shown in FIGS. 8 and 9 was manufactured. The constituent fibers supplied to the manufacturing apparatus 100B are shown in Table 2 below. As shown in Table 2, the constituent fiber is a fiber made of only a high elongation fiber and having no elasticity (elastomer). The high elongation fiber was a concentric core-sheath type composite fiber having a core part made of polyethylene terephthalate and a sheath part made of polyethylene. The elongation of the high elongation fiber was 350%. In addition, regarding the manufacturing apparatus 100B, the distance (pitch) between the large-diameter convex portions 404, 404 included in the pair of concave and convex rolls 401, 402 is 2 mm, and the pressing amount of the pair of concave and convex rolls 401, 402 is 1.2 mm. Yes, and the mechanical draw ratio was 1.9 times.

[Example 2B]
Regarding the manufacturing apparatus 100B in Example 1B, the push-in amount of the pair of concavo- convex rolls 401 and 402 is changed to 1.6 mm, and the mechanical stretching ratio is changed to 2.3 times. A nonwoven fabric was produced.

[Example 3B]
Regarding the manufacturing apparatus 100B in Example 1B, the amount of pressing of the pair of concave and convex rolls 401 and 402 is changed to 2.0 mm, and the mechanical stretching ratio is changed to 2.7 times, in the same manner as in Example 1B. A nonwoven fabric was produced.

[Example 4B]
Regarding the constituent fibers in Example 1B, the nonwoven fabric of Example 4B was produced in the same manner as Example 1B, except that the elongation of the high elongation fiber was changed to 250%.

[Example 5B]
Regarding the constituent fibers in Example 2B, the nonwoven fabric of Example 5B was manufactured in the same manner as Example 2B, except that the elongation of the high elongation fiber was changed to 250%.

[Example 6B]
Regarding the constituent fibers in Example 3B, the nonwoven fabric of Example 6B was produced in the same manner as Example 3B, except that the elongation of the high elongation fiber was changed to 250%.

[Comparative Example 1B]
The constituent fiber in Example 1B was changed to a composite fiber that had already been drawn. Specifically, the elongation of the composite fiber was 80% drawn fiber. A nonwoven fabric of Comparative Example 1B was produced in the same manner as Example 1B except that the fiber was changed.

[Comparative Example 2B]
Regarding the constituent fiber in Example 3B, the composite fiber was changed to an already drawn composite fiber. Specifically, the elongation of the composite fiber was 80% drawn fiber. A nonwoven fabric of Comparative Example 2B was produced in the same manner as Example 3B except that the fiber was changed.

[Comparative Example 3B]
By the method according to the manufacturing method described in Patent Document 1, the nonwoven fabric of Comparative Example 3B was formed so as to include the high elongation fiber that is the constituent fiber in Example 4B and the elastic fiber. In addition, the pushing amount of the pair of concave and convex rolls 401 and 402 and the mechanical stretching ratio are the same as in Example 4B.

[Comparative Example 4B]
By the method according to the manufacturing method described in Patent Document 1, the nonwoven fabric of Comparative Example 4B was formed so as to include the high elongation fiber that is the constituent fiber in Example 6B and the elastic fiber. In addition, the pushing amount of the pair of concave and convex rolls 401 and 402 and the mechanical stretching ratio are the same as in Example 6B.

<Evaluation>
Regarding the nonwoven fabrics of Examples 1B to 6B and Comparative Examples 1B to 4B, the existence ratio of the change point 18 from the small diameter portion 16 to the large diameter portion 17 is evaluated by the following method. 18 positions were measured. Moreover, the fiber diameter of the small diameter part 16 and the large diameter part 17 was measured by the method mentioned above. The results are shown in Table 2 below.
Further, with respect to the nonwoven fabrics of Examples 1B to 6B and Comparative Examples 1B to 4B, the fiber density in the top region 13a, the bottom region 13b or the side region 13c, and the top region 13a, the bottom region 13b or the side by the method described above. The number of change points 18 in the area 13c was measured. The results are shown in Table 2 below.
Further, with respect to the nonwoven fabrics of Examples 1B to 6B and Comparative Examples 1B to 4B, the touch and liquid permeability were evaluated by the following methods. The results are shown in Table 2 below.

[Evaluation of the ratio of change points 18]
The 20 constituent fibers of the nonwoven fabric were extracted at random, and each constituent fiber was magnified 110 times using a scanning electron microscope: JCM-5100 (trade name) manufactured by JEOL Ltd. The presence or absence of the changing point 18 from the large diameter portion 17 to the large diameter portion 17 was observed. The existence ratio was calculated as follows. Abundance ratio (%) = number of fibers having changing point 18/20 fibers × 100
Here, as described above, the change point 18 is a part that continuously changes gradually from a small diameter part to a large diameter part or a part that continuously changes over a plurality of stages, and a core part of a constituent fiber. It means a part where the fiber diameter changes extremely without including the state in which the fiber diameter changes by peeling between the 1 resin component and the second resin component constituting the sheath.

[Evaluation of the position of the change point 18]
When there is a change point 18, the interval T between the adjacent fusion portions 12, 12 is divided into three equal parts, the region AT on one fusion portion 12 side, the region BT on the other fusion portion 12 side, The area is divided into a central area CT. And it observed that the change point 18 was distribute | arranged to any of said area | region AT, said area | region BT, or center area | region CT.
<Evaluation results>
A: Among fibers having change points, there are a plurality of fibers having change points in the region AT or the region BT and also in the central region CT.
B: Among fibers having changing points, there are a plurality of fibers having changing points only in the region AT or the region BT.
C: Among fibers having change points, there are a plurality of fibers having change points only in the central region CT.

[Evaluation of the feel of nonwoven fabric]
Twenty monitors were touched in a state where the nonwoven fabric was not visible, and the touches such as flexibility, softness, and cushioning properties were comprehensively evaluated according to the following five criteria. The results are shown as an average value of 20 people.
<Evaluation criteria>
5: Very good 4: Good 3: Normal 2: Bad 1: Very bad In addition, if the average evaluation result of 20 people is 4 or more, improvement of the touch is recognized by the user and high evaluation is obtained. Is a level that can be expected.

[Evaluation of liquid permeability of nonwoven fabric]
The liquid permeability of the non-woven fabric was measured according to the “153.0-02 REPEATED Liquid Strike-Through Time” method of EDANA (European Non-woven Industries Association) using a strike-through time measuring device Lister manufactured by Lenzing Technik. Liquid Strike-Through Time indicates the time (seconds) required for a predetermined amount of physiological saline to pass from the front surface to the back surface of the nonwoven fabric. Specifically, ten sheets of dedicated filter paper were placed on the pedestal of the testing machine, and a nonwoven fabric was placed thereon. Next, a strike-through plate having electrodes was placed on the nonwoven fabric, and physiological saline (Otsuka Pharmaceutical Co., Ltd., Otsuka Pharmaceutical Co., Ltd. 10 ml of the product name was put in, and then the tester was turned on.From the state in which the physiological saline touched the electrode, the physiological saline passed through the nonwoven fabric, the water level dropped, and the electrode was not in contact with the electrode. The average time was taken as the liquid permeation time of the nonwoven fabric, and the shorter the liquid permeation time, the better the liquid permeability.

According to the results of Table 2, the non-woven fabrics of Examples 1B to 6B have a change point 18 from the small diameter portion 16 to the large diameter portion 17 in the region AT or region as compared with the non-woven fabrics of Comparative Example 1B to Comparative Example 4B. The presence of the small-diameter portion 16 having a low rigidity so as to be adjacent to the fused portion 12 that is present in the BT, in other words, the stiffness of the nonwoven fabric is increased, so that the flexibility of the nonwoven fabric is improved and the touch is good. I understood.
Furthermore, since the nonwoven fabrics of Example 1B to Example 6B have many change points 18 in the side region 13c, the ridges 13 can easily follow the movement of the wearer's skin and have a good touch. I understood. In addition, the nonwoven fabrics of Examples 1B to 6B were found to have good liquid permeability because the positions of the change points 18 are many in the side region 13c and the fiber density in the side region 13c is low.

Further, according to the results of Table 2, since the nonwoven fabrics of Comparative Examples 1B to 2B use stretched fibers having low elongation, the first resin component constituting the core portion of the constituent fibers by stretching, and the sheath portion Peeling occurs between the constituent second resin components. For this reason, the peeled portion of the sheath is caught on the skin, and the touch is lowered. Since it is difficult to maintain the uneven shape and the core portion is exposed and water-repellent, the liquid passing time is reduced. Next, the nonwoven fabric of Comparative Example 3B has a configuration in which elastic fibers are contained in the nonwoven fabric of Example 4B. As described above, when elastic fibers are contained, the nonwoven fabric is stretched while being contracted. Therefore, even when the mechanical draw ratio is the same, it is difficult to form a change point, and the fiber density is not easily lowered. Thereby, the nonwoven fabric of Comparative Example 3B is less likely to produce an effect of improving the touch and liquid permeability. Next, the nonwoven fabric of Comparative Example 4B has a configuration in which elastic fibers are contained in the nonwoven fabric of Example 6B. As described above, when elastic fibers are contained, the nonwoven fabric is stretched while being contracted. Therefore, it is difficult to make a change point that is a part where the fiber diameter changes extremely in the present application, and from the small diameter portion 16 to the large diameter portion 17 continuously. A site that gradually changes is likely to be formed. In the nonwoven fabric of Comparative Example 4B, the continuously and gradually formed portion is not observed near the fusion point because it contains elastic fibers and is not easily stretched locally near the fusion point. Thereby, the nonwoven fabric of Comparative Example 4B is less likely to have an effect of improving the touch and improving liquid permeability.

According to the present invention (first invention), there is little liquid residue on the surface and dry touch properties are improved.

According to the present invention (second invention), the touch can be further improved.

Claims (57)

1. A non-woven fabric provided with a plurality of fusion parts formed by heat-sealing the intersections of the constituent fibers,
   The constituent fibers include high elongation fibers,
   Paying attention to one of the constituent fibers, the constituent fiber has a large diameter portion having a large fiber diameter sandwiched between two small diameter portions having a small fiber diameter between the adjacent fused portions. And
   A nonwoven fabric in which the hydrophilicity of the small diameter portion is smaller than the hydrophilicity of the large diameter portion.
2. The nonwoven fabric according to claim 1, wherein a difference between the contact angle of the small diameter portion and the contact angle of the large diameter portion (the former-the latter) is 1 degree or more and 25 degrees or less.
3. The non-woven fabric according to claim 1 or 2, wherein a contact angle of the small diameter portion is 60 degrees or more and 100 degrees or less.
4. The nonwoven fabric according to any one of claims 1 to 3, wherein a contact angle of the large diameter portion is 55 degrees or more and 90 degrees or less.
5. The ratio (L ₁₆ / L ₁₇ ) of the fiber diameter (diameter L ₁₆ ) of the small diameter portion to the fiber diameter (diameter L ₁₇ ) of the large diameter portion is 0.5 or more and 0.8 or less. The nonwoven fabric of any one of these.
6. The changing point from the small diameter part adjacent to the fusion part to the large diameter part is arranged within a range of 1/3 of the interval between the fusion parts adjacent to the fusion part,
   The non-woven fabric is a non-woven fabric having a concavo-convex structure in which streaky ridges and ridges extending in one direction are alternately arranged,
   The non-woven fabric has a top region, a bottom region, and a side region located therebetween,
   The top of the ridge is formed from the top region, the bottom of the ridge is formed from the bottom region,
   The side region is configured with respect to the number (N ₁₃ ) of fibers having change points in the constituent fibers constituting the top region or the number of fibers (N ₁₄ ) having change points in the constituent fibers constituting the bottom region. The ratio (N ₁₅ / N ₁₃ , N ₁₅ / N ₁₄ ) of the number (N ₁₅ ) of fibers having change points in the constituent fibers is 2 or more and 20 or less, according to any one of claims 1 to 5. Non-woven fabric.
7. A fiber treating agent is attached to the constituent fibers,
   The nonwoven fabric according to any one of claims 1 to 6, wherein the fiber treatment agent contains a spreadable component.
8. The absorbent article according to claim 7, wherein the spreadable component is a component that, when attached to the surface of the fiber, easily spreads on the surface of the fiber at a low temperature and has excellent fluidity at a low temperature.
9. The nonwoven fabric according to claim 7 or 8, wherein the spreadable component is polyorganosiloxane.
10. The nonwoven fabric according to claim 9, wherein the polyorganosiloxane is selected from polydimethylsiloxane, polydiethylsiloxane, and polydipropylsiloxane.
11. The nonwoven fabric according to any one of claims 7 to 10, wherein the fiber treatment agent further contains a hydrophilic component.
12. The nonwoven fabric according to claim 11, wherein the hydrophilic component is a zwitterionic surfactant or a nonionic surfactant.
13. The nonwoven fabric according to claim 12, wherein the zwitterionic surfactant is a betaine-type zwitterionic surfactant.
14. The nonionic surfactant is selected from glycerin fatty acid ester, polyglycerin fatty acid ester, sorbitan fatty acid ester, polyhydric alcohol fatty acid ester, polyoxyalkylene alkylamide, polyoxyalkylene alkyl ether, polyoxyalkylene-modified silicone, and amino-modified silicone. The nonwoven fabric according to claim 12, which is selected.
15. The nonwoven fabric according to any one of claims 7 to 14, wherein the fiber treatment agent further contains a hydrophobic component.
16. The nonwoven fabric according to claim 15, wherein the hydrophobic component is selected from an alkyl phosphate ester, an anionic surfactant represented by the following general formula (1), and the like.
    

    

    (Wherein Z represents an ester group, an amide group, an amine group, a polyoxyalkylene group, an ether group or a linear or branched alkyl chain having 1 to 12 carbon atoms, which may contain a double bond; R ₁ and R ₂ each independently represents an ester group, an amide group, a polyoxyalkylene group, an ether group or a linear or branched alkyl group having 2 to 16 carbon atoms, which may contain a double bond. , X represents —SO ₃ M, —OSO ₃ M or —COOM, and M represents H, Na, K, Mg, Ca or ammonium.)
17. The nonwoven fabric according to claim 16, wherein the alkyl phosphate ester is a completely or partially neutralized salt of a mono- or dialkyl phosphate ester having a carbon chain of 16 to 18.
18. The nonwoven fabric according to any one of claims 1 to 17, wherein the constituent fibers are composed of high elongation fibers only.
19. The high elongation fiber is obtained by performing heat treatment and / or crimping treatment without drawing treatment after obtaining a composite fiber by melt spinning at low speed except for elastic fiber that has elasticity and stretches. Heat-extensible fibers whose length changes due to the change in the crystalline state of the resin resulting from heating, or fibers produced under relatively low spinning speeds using resins such as polypropylene and polyethylene, or crystallinity The nonwoven fabric according to claim 18, which is selected from a low-polyethylene-polypropylene copolymer, or a fiber produced by dry blending and spinning polyethylene into polypropylene.
20. The nonwoven fabric according to claim 18 or 19, wherein a ratio of high elongation fibers in the nonwoven fabric is 50 mass% or more.
21. The high elongation fiber means not only a fiber having a high elongation at the stage of a raw material fiber but also a fiber having a high elongation at a stage of the produced nonwoven fabric. The nonwoven fabric according to item.
22. The nonwoven fabric according to any one of claims 18 to 21, wherein the elongation of the high elongation fiber is 100% or more and 800% or less at a raw material stage.
23. The nonwoven fabric according to any one of claims 18 to 22, wherein the elongation of the high elongation fiber is 60% or more and 200% or less at the stage of the nonwoven fabric.
24. The change point from the small diameter part adjacent to the fusion part to the large diameter part is arranged within a range of 1/3 of the interval between the fusion parts adjacent to the fusion part. 24. The nonwoven fabric according to any one of 1 to 23.
25. The nonwoven fabric according to any one of claims 1 to 24, wherein a plurality of the large-diameter portions are arranged between the adjacent fused portions, paying attention to one of the constituent fibers.
26. The non-woven fabric according to any one of claims 1 to 25, wherein the non-woven fabric is a non-woven fabric having a concavo-convex structure in which streaky ridges and ridges extending in one direction are alternately arranged.
27. The non-woven fabric has a top region, a bottom region, and a side region located therebetween,
    The top of the ridge is formed from the top region, the bottom of the ridge is formed from the bottom region,
    The nonwoven fabric according to claim 26, wherein the fiber density in the side region is smaller than the fiber density in the top region and the fiber density in the bottom region.
28. The non-woven fabric has a top region, a bottom region, and a side region located therebetween,
    The top of the ridge is formed from the top region, the bottom of the ridge is formed from the bottom region,
    The number of fibers having change points in the constituent fibers constituting the side region, the number of fibers having change points in the constituent fibers constituting the top region, and the change point in the constituent fibers constituting the bottom region The nonwoven fabric according to claim 25 or 27, wherein the number is greater than
29. The fiber treatment agent is formed from constituent fibers obtained by adhering a fiber web containing the constituent fibers to the constituent fibers before the stretching treatment and drying the fiber web at a temperature sufficiently lower than the melting point of the polyethylene resin. The nonwoven fabric according to 7.
30. The nonwoven fabric according to any one of claims 1 to 29, wherein an intersection between the constituent fibers is a joining point, and the joining point is the fusion part.
31. An absorbent article having a top sheet disposed on the skin facing surface side, a back sheet disposed on the non-skin facing surface side, and an absorbent body interposed between the both sheets,
    The absorbent article, wherein the surface sheet is formed of the nonwoven fabric according to any one of claims 1 to 30.
32. A non-woven fabric provided with a plurality of fusion parts formed by heat-sealing the intersections of the constituent fibers,
    The constituent fibers include high elongation fibers,
    Paying attention to one of the constituent fibers, the constituent fiber has a large diameter portion having a large fiber diameter sandwiched between two small diameter portions having a small fiber diameter between the adjacent fused portions. And
    The change point from the small-diameter portion adjacent to the fused portion to the large-diameter portion is disposed within a range of ３ of the interval between the fused portions adjacent to the fused portion. 31. The nonwoven fabric according to any one of 1 to 30.
33. The small diameter portion of the fiber diameter (diameter _{L 16),} the nonwoven fabric according to claim 32 is 5μm or more 28μm or less.
34. The nonwoven fabric according to any one of claims 32 and 33, wherein a fiber diameter (diameter L ₁₇ ) of the large diameter portion is 10 µm or more and 35 µm or less.
35. The nonwoven fabric according to any one of claims 32 to 34, wherein the change point is formed by changing a fiber diameter by stretching.
36. The non-woven fabric according to any one of claims 32 to 35, wherein the non-woven fabric has 1 or more and 5 or more constituent fibers having the change point in 20 constituent fibers.
37. The absorbent article according to claim 6, wherein the number (N ₁₃ ) of fibers having the change point in the constituent fibers constituting the top region is 1 or more and 15 or less.
38. The nonwoven fabric according to claim 6 or 37, wherein the number (N ₁₄ ) of fibers having the changing point in the constituent fibers constituting the bottom region is 1 or more and 15 or less.
39. 39. The nonwoven fabric according to claim 6, 37 or 38, wherein the number (N ₁₅ ) of fibers having the change point in the constituent fibers constituting the side region is 5 or more and 20 or less.
40. The nonwoven fabric according to any one of claims 32 to 39, wherein the constituent fibers are composed of inelastic fibers only.
41. The nonwoven fabric according to any one of claims 32 to 40, wherein the fineness of the high elongation fiber is 1.0 dtex or more and 10.0 dtex or less at a raw material stage.
42. The nonwoven fabric according to any one of claims 32 to 41, wherein a plurality of the large-diameter portions are arranged between the adjacent fused portions by paying attention to one of the constituent fibers.
43. The non-woven fabric according to any one of claims 32 to 42, wherein paying attention to one of the constituent fibers, the non-woven fabric according to any one of claims 32 to 42, wherein one or more and five or less large-diameter portions are provided between the adjacent fused portions. .
44. The non-woven fabric according to any one of claims 32 to 43, wherein the non-woven fabric is a non-woven fabric having a concavo-convex structure in which streaky ridges and ridges extending in one direction are alternately arranged.
45. The non-woven fabric has a top region, a bottom region, and a side region located therebetween,
    The top of the ridge is formed from the top region, the bottom of the ridge is formed from the bottom region,
    The nonwoven fabric according to claim 44, wherein the fiber density in the side region is smaller than the fiber density in the top region and the fiber density in the bottom region.
46. The non-woven fabric is a non-woven fabric having a concavo-convex structure in which streaky ridges and ridges extending in one direction are alternately arranged,
    The non-woven fabric has a top region, a bottom region, and a side region located therebetween,
    The top of the ridge is formed from the top region, the bottom of the ridge is formed from the bottom region,
    Ratio (D ₁₅ / D ₁₃ ) of the fiber density (D ₁₅ ) of the wall portion between the bottom region and the fiber density (D ₁₃ ) in the top region or the fiber density (D ₁₄ ) in the bottom region , D ₁₅ / D ₁₄ ) is 0.15 or more and 0.9 or less, and the nonwoven fabric according to any one of claims 32 to 45.
47. The fiber density _{(D 13)} in the top zone, 80 present / mm ² or more 200 present / mm ² or less nonwoven fabric according to claim 46.
48. The fiber density _{(D 14)} in the bottom zone, 80 present / mm ² or more 200 present / mm ² or less nonwoven fabric according to claim 46 or 47.
49. The fiber density _{(D 15)} of the bottom zone, 30 lines / mm ² or more eighty / mm ² or less nonwoven fabric according to any one of claims 46-48 is.
50. The number of fibers having change points in the constituent fibers constituting the side region, the number of fibers having change points in the constituent fibers constituting the top region, and the change point in the constituent fibers constituting the bottom region The nonwoven fabric according to any one of claims 45 to 49, wherein the number of the nonwoven fabrics is larger than the number of the nonwoven fabrics.
51. A fusion process in which the intersection of the constituent fibers of the fiber web including the high elongation fiber to which the fiber treatment agent is applied is thermally fused at the fusion part;
    A non-woven fabric manufacturing method comprising a stretching step of stretching the fused fiber web in one direction after the fusing step,
    In the stretching step, the fiber web is stretched, and the fiber having a large fiber diameter is sandwiched between two small-diameter portions having a small fiber diameter between one of the constituent fibers between the adjacent fused portions. A method for producing a nonwoven fabric, in which a diameter portion is formed and the hydrophilicity of the small diameter portion is made smaller than the hydrophilicity of the large diameter portion.
52. In the stretching step, the fiber sheet is stretched, and the fiber having a large fiber diameter is sandwiched between two small-diameter portions having a small fiber diameter in one constituent fiber between the adjacent fused portions. The diameter portion is formed, and the changing point from the small diameter portion to the large diameter portion is formed within a range of 1/3 of the interval between the fusion portions adjacent to the fusion portion. The manufacturing method of the nonwoven fabric as described.
53. The manufacturing apparatus used in the method for manufacturing the nonwoven fabric includes a stretching section,
    The extending portion includes a pair of first concavo-convex rolls and second concavo-convex rolls that can be engaged with each other,
    The interval between the large-diameter convex portions adjacent to each other in the roll axis direction of the first concave-convex roll and the interval between the large-diameter convex portions adjacent to each other in the roll axis direction of the second concave-convex roll are from 1 mm to 10 mm. 52. A method for producing a nonwoven fabric according to 52.
54. 54. The method for producing a nonwoven fabric according to any one of claims 52 and 53, wherein an indentation amount of the first uneven roll and the second uneven roll is 1 mm or more and 3 mm or less.
55. The method for producing a nonwoven fabric according to any one of claims 52 to 54, wherein a mechanical stretch ratio of the first uneven roll and the second uneven roll is 1.5 times or more and 3.0 times or less.
56. A nonwoven fabric produced by the production method according to any one of claims 51 to 55.
57. An absorbent article having a top sheet disposed on the skin facing surface side, a back sheet disposed on the non-skin facing surface side, and an absorbent body interposed between the both sheets,
    The absorbent article, wherein the topsheet is formed of the nonwoven fabric according to any one of claims 32 to 50 and 56.
    
    

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