JP6440449B2 - Absorbent articles - Google Patents

Description

  The present invention relates to absorbent articles such as sanitary napkins and disposable diapers.

  As a surface sheet of an absorbent article, one having a concavo-convex structure in which streaky ridges and ridges extending in one direction are alternately arranged in the width direction is known. For example, the present applicant has proposed a surface sheet obtained by linearly bonding a sheet for forming irregularities in which a plurality of hook-shaped portions are formed in parallel to each other between the hook-shaped portions (see Patent Document 1). ).

  Patent Document 2 describes a surface sheet formed of a liquid-permeable fiber nonwoven fabric and shaped into a wave shape. The wave shape is continuously formed in the longitudinal direction of the surface sheet. The corrugated top and bottom extend in a direction intersecting the longitudinal direction of the topsheet. The density of the fibers in the wall region between the corrugated top and bottom regions is lower than the fiber density in the top or bottom region.

JP 2002-165830 A JP 2008-1113866 A

  According to the surface sheet of patent document 1, the effect that the liquid with comparatively high viscosity taken in between the hook-shaped parts can be isolated from a wearer's skin is exhibited. However, it is desired to further improve the absorbability when a large amount of urine or a relatively low viscosity liquid is supplied. Moreover, in the technique of patent document 2, since the convex part and recessed part which are extended in the width direction of an absorbent article are formed in the surface sheet, when a lot of liquids are supplied, it leaks from the both ends of the width direction. (So-called side leakage) and may cause the skin of the wearer to be sticky.

  Therefore, the subject of this invention is providing the absorbent article which can eliminate the fault which the prior art mentioned above has.

  The present invention comprises an absorbent article having a longitudinal direction and a width direction, comprising a liquid-permeable surface sheet that forms a skin contact surface, a back sheet, and an absorbent body interposed between the two sheets. The top sheet is composed of a non-woven fabric having a concavo-convex structure in which strip-like ridges and recesses extending in the longitudinal direction are alternately arranged in the width direction, and is joined to an adjacent lower sheet in the recess, The non-woven fabric in which a protruding portion has a hollow structure between the lower sheet, the lower sheet is made of an aggregate of fibers, and the fiber density of the aggregate of fibers constitutes the surface sheet An absorbent article having a fiber density higher than that of the present invention is provided.

  According to the absorbent article of the present invention, it is possible to reliably suppress discomfort caused by the excretion fluid coming into contact with the wearer's skin, and to effectively utilize the absorption capacity of the absorber.

FIG. 1 is a perspective view showing an incontinence pad according to an embodiment of the present invention. 2A is an enlarged cross-sectional view taken along the line II-II of FIG. 1, and FIG. 2B is a diagram showing the back surface (surface on the non-skin contact surface side) of the absorbent body of the incontinence pad shown in FIG. is there. FIG. 3 is a partially broken perspective view showing an enlarged main portion of the incontinence pad shown in FIG. FIG. 4 is an enlarged schematic view of the main part in FIG. FIG. 5 is a diagram for explaining a state in which the constituent fibers constituting the nonwoven fabric shown in FIG. 3 are fixed at the heat fusion part. FIG. 6 is a partially extracted enlarged plan view of the skin contact surface of the incontinence pad, showing an example of the arrangement of the joint portion between the concave strip portion of the top sheet and the lower sheet. FIG. 7 is an explanatory diagram of the function and effect of the present invention. FIG. 8 is a schematic view showing a manufacturing apparatus suitably used for manufacturing the nonwoven fabric shown in FIG. 9 is a cross-sectional view taken along the line DD of FIG. FIG. 10A to FIG. 10C 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. 11 is a partially enlarged plan view of an absorbent body showing another example of the arrangement of the compression parts that form the high-density part. FIG. 12 is a cross-sectional view showing another absorber that can be used in the present invention.

The present invention will be described below based on preferred embodiments with reference to the drawings.
FIG. 1 is a perspective view of an incontinence pad 10 (hereinafter also simply referred to as “incontinence pad 10”) according to an embodiment of the present invention. 2A is an enlarged cross-sectional view taken along the line II-II in FIG. 1, and FIG. 2B is a view showing the back surface (surface on the non-skin contact surface side) of the absorbent body of the incontinence pad 10 shown in FIG. It is.

  As shown in FIGS. 1 and 2A, the incontinence pad 10 includes a liquid-permeable top sheet 2 that forms a skin contact surface, a liquid-impermeable back sheet 3, and a space between the two sheets 2 and 3. The absorbent body 4 is provided. Liquid impermeability includes liquid impermeability. The incontinence pad 10 has a vertically long shape, and has a longitudinal direction X and a width direction Y. The longitudinal direction X coincides with the wearer's front-rear direction when the incontinence pad 10 is worn, and the width direction Y is a direction orthogonal to the longitudinal direction X in the plan view of the incontinence pad 10. The incontinence pad 10 has an oval shape in plan view.

  The top sheet 2 and the back sheet 3 extend from the periphery of the absorber 4. On the surface (non-skin contact surface) on the back sheet 3 side of the incontinence pad 10, an adhesive portion (not shown) for fixing to underwear such as shorts is provided. The skin contact surface is a surface directed to the wearer's skin side when worn in the absorbent article or a component thereof, and the non-skin contact surface is the wearer's skin when worn in the absorbent article or component thereof. It is the surface that is directed to the side opposite to the skin side (usually the underwear side).

The absorbent body 4 of the incontinence pad 10 includes an absorbent core 40 and a core wrap sheet 41 that wraps the absorbent core 40. The absorptive core 40 can be comprised from the laminated fiber body of liquid absorbing fibers, such as a pulp, for example, and the mixed fiber body of this liquid absorbing fiber and a water absorbing polymer. Examples of the liquid-absorbing fibers constituting the absorbent core 40 include cellulose-based hydrophilic fibers such as pulp fibers, rayon fibers, cotton fibers, and cellulose acetate. In addition to cellulose-based hydrophilic fibers, polyolefin fibers such as polyethylene and polypropylene, and condensation fibers such as polyester and polyamide may be included. Examples of water-absorbing polymers include sodium polyacrylate, (acrylic acid-vinyl alcohol) copolymer, cross-linked sodium polyacrylate, (starch-acrylic acid) graft copolymer, and (isobutylene-maleic anhydride) copolymer. Examples thereof include a polymer and a saponified product thereof, and polyaspartic acid. Each of the fibers and the water-absorbing polymer can be used alone or in combination of two or more.
As the core wrap sheet 41, a water-permeable fiber sheet such as tissue paper or nonwoven fabric is preferably used. The core wrap sheet 41 may wrap the entire absorbent core 40 with one sheet, or may wrap the entire absorbent core 40 with two or more core wrap sheets. The skin contact surface side and the non-skin contact surface side of the absorbent core 40 may be covered with separate sheets.

The thickness of the absorber 4 is preferably 1 mm or more, more preferably 2 mm or more, preferably 15 mm or less, more preferably 10 mm or less, and preferably 1 mm or more and 15 mm or less, more preferably 2 mm or more and 10 mm or less. is there.
The thickness of the absorber 4 is measured by the following method.
The thickness T is measured using a peacock precision measuring instrument (model R1-C) which is a micrometer having two parallel pressure surfaces (a fixed pressure surface and a movable pressure surface). Measurement is performed at 5 mm and a pressure of 100 kPa or less. A 20 mm × 20 mm plate (weight: 5.4 g) is placed on the test piece, the measuring element movable pressurizing surface is operated at a speed of 2 mm / s, applied to the plate, and the value immediately after stabilization is read. The pressure between the pressing surfaces (pressure applied to the test piece) is 1.3 kPa or less.

  As the forming material of the back sheet 3, various materials conventionally used for the back sheet of the absorbent article can be used without particular limitation. For example, a liquid-impermeable or water-repellent resin film, a resin film, A laminate sheet with a non-woven fabric can be used.

  Leak-proof cuffs 8 extending in the longitudinal direction are respectively provided at positions on both sides in the width direction Y on the skin contact surface side of the incontinence pad 10. The leak-proof cuff 8 has a free end 8a and a fixed area 8b extending in the longitudinal direction. The fixed area 8b is located on the top sheet 2. The leak-proof cuff 8 is fixed to the top sheet 2 in the fixing region 8b. Further, the fixing region 8b of the leak-proof cuff 8 extends outward in the width direction Y, and the extending portion and the width direction extending portion of the back sheet 3 are joined to form the side flap 7. . In the leak-proof cuff 8, an elastic member 8c extending along the longitudinal direction X is attached in a stretched state at a position at or near the free end 8a. A plurality of elastic members 8c are arranged substantially parallel to each other. The portion where the plurality of elastic members 8c are attached forms a planar elastic region 8d. The planar elastic region 8d has a predetermined length along the width direction Y and extends along the longitudinal direction X at least at the position of the wearer's excretory part. The planar elastic region 8d can be expanded and contracted along the longitudinal direction X. As the elastic member 8c contracts, the leak-proof cuff 8 has a planar elastic structure in which the position between the free end 8a and the fixed end 8b rises in a substantially L shape toward the wearer's body. The region 8d is in contact with the wearer's skin and prevents side leakage of the liquid.

  As shown in FIG. 2A and FIG. 3, the surface sheet 2 in the incontinence pad 10 according to the present embodiment has stripe-like protruding ridges 13 and ridges 14 extending in the longitudinal direction alternately arranged in the width direction. It is comprised from the nonwoven fabric 1 of the uneven structure. Moreover, as shown in FIG. 2A and FIG. 3, the topsheet 2 is joined to the adjacent second sheet 6 (lower sheet) at the joint 14 s at the joint 14, and the convex strip part. 13 has a hollow structure with the second sheet 6. As shown in FIG. 5, the nonwoven fabric 1 constituting the top sheet 2 includes fibers 11 having a large diameter portion 17 and small diameter portions 16 and 16 having different fiber diameters.

The non-woven fabric 1 constituting the top sheet 2 will be described in more detail.
FIG. 3 shows a perspective view of the nonwoven fabric 1 (hereinafter also referred to as “nonwoven fabric 1”) used as the top sheet 2 in the incontinence pad 10 of the present embodiment. FIG. 4 is a schematic diagram showing a cross section in the thickness direction of the nonwoven fabric 1 shown in FIG. 3. FIG. 5 is an enlarged schematic view of the constituent fibers 11 of the nonwoven fabric 1 shown in FIG. As shown in FIG. 3, the nonwoven fabric 1 is a nonwoven fabric provided with a plurality of fused portions 12 (see FIG. 5) formed by thermally fusing the intersections of the constituent fibers 11. Moreover, in the nonwoven fabric 1 which comprises the surface sheet 2, as shown in FIG. 3, the "one direction" where the protruding line part 13 and the recessed line part 14 extend is the same direction as the longitudinal direction X of the incontinence pad 10, In the nonwoven fabric 1, “one direction” in which the ridges 13 and the recesses 14 extend is also referred to as an X direction.

  More specifically, as shown in FIG. 4, the nonwoven fabric 1 includes a plurality of ridge portions 13 in which the cross-sectional shapes of 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 adjacent convex line parts 13 and 13. FIG. As for the concave-line part 14, the cross-sectional shape of front and back both surfaces a and b has comprised the concave shape toward the upper direction of the thickness direction (Z direction) of a nonwoven fabric. In other words, as for the concave stripe 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 1, and each of the plurality of ridges 14 extends continuously in one direction X of the nonwoven fabric 1. 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).

  The concavo-convex structure of the nonwoven fabric 1 composed of the ridges 13 and the ridges 14 is preferably formed at least in the central region in the width direction Y of the incontinence pad 10. As a result, the uneven structure can be provided in a part that is most likely to come into contact with the wearer's skin, so that the above-described effects such as prevention of stickiness are more reliably exhibited.

  The constituent fiber 11 of the nonwoven fabric 1 includes 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 produced nonwoven fabric 1. 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 under relatively low spinning speeds using resins 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 is 1.0 dtex or more and 10.0 dtex or less at the raw material stage. Is preferable, and more preferably 2.0 dtex or more and 8.0 dtex or less.

  The constituent fibers 11 of the nonwoven fabric 1 may be configured to include other fibers in addition to the high elongation fibers, but are preferably configured only from the high elongation fibers. 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 1 is configured to include other fibers in addition to the high elongation fibers, the proportion of the high elongation fibers in the nonwoven fabric 1 is preferably 50% by mass to 100% by mass, and more preferably It is 80 mass% or more and 100 mass% or less.

  The heat-extensible fiber, which is a high-stretch fiber, is a composite fiber that has been subjected to unstretched or weakly stretched treatment at the raw material stage. For example, the first resin component that forms the core and the sheath And a second resin component containing a polyethylene resin, and the first resin component has 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 a 1st resin component which comprises a core part, the resin component whose melting | fusing point is higher than the polyethylene resin which is a constituent resin of a sheath part can be especially used without a restriction | limiting. 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 production of the nonwoven fabric becomes easy, the difference (the former-the latter) 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 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 heat-extensible fiber, which is 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 may be 60% or less. Preferably, it is 40% or less, more preferably 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 JP2010-168715A. Moreover, the method in which each resin component in the thermally stretchable conjugate fiber achieves the orientation index as described above is described in paragraphs [0033] to [0036] of JP-A No. 2010-168715.

  Further, the elongation of the high elongation fiber is preferably 100% or more and 800% or less, more preferably 200% or more and 500% or less, and further preferably 250% or more and 400% or less at the raw material stage. By using the high elongation fiber having the elongation in this range, the fiber is successfully stretched in the stretching apparatus, and the changing point from the small diameter portion to the large diameter portion described above is adjacent to the fusion portion. , The touch becomes good.

  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 (mass ratio, the former: latter) of the first resin component and the second resin component 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 preferable that it is 50: 50-70: 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 depending on the specific use of the nonwoven fabric at the raw material stage. When the nonwoven fabric is used as a constituent member of an absorbent article such as a surface sheet of the absorbent article, it is preferable to use a nonwoven fabric having a size of 10 μm to 35 μm, particularly 15 μm to 30 μm. The fiber diameter is measured by the following method.

[Measurement of fiber diameter]
As the fiber diameter of the fiber, the diameter (μm) of the fiber 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, as the heat-extensible fiber that is 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. 2007-303035, The fibers described in JP 2007-204899 A, JP 2007-204901 A, and JP 2007-204902 A can also be used.

  As shown in FIG. 5, the nonwoven fabric 1 pays attention to one constituent fiber 11 among the constituent fibers 11 of the nonwoven fabric 1, and the constituent fiber 11 is between the adjacent fusion portions 12 and 12. It is preferable to have a large diameter portion 17 having a large fiber diameter sandwiched between two small diameter portions 16 and 16 having a small fiber diameter. Specifically, as shown in FIG. 5, focusing on one constituent fiber 11 among the constituent fibers 11 of the nonwoven fabric 1, a fusion formed by thermally fusing an intersection with another constituent fiber 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. Specifically, the non-woven fabric 1 focuses on one constituent fiber 11 and moves from one fused part 12 to the other fused part 12 of the adjacent fused parts 12, 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.

As described above, the low-rigidity small-diameter portion 16 is adjacent to the fused portion 12 where the rigidity of the nonwoven fabric 1 is increased, so that the flexibility of the nonwoven fabric 1 is improved and the touch is improved. Moreover, the softness | flexibility of the nonwoven fabric 1 improves further and the touch becomes still more favorable, so that the small diameter part 16 with low rigidity is provided in the component fiber 11 in multiple numbers.
As shown in FIG. 5, the nonwoven fabric 1 focuses on one constituent fiber 11 among the constituent fibers 11 of the nonwoven fabric 1, and includes a plurality of large-diameter portions 17 between the adjacent fusion portions 12, 12. (2 in the nonwoven fabric 1) It has the constituent fiber 11 provided. Specifically, the non-woven fabric 1 focuses on one constituent fiber 11 and moves from one fused part 12 to the other fused part 12 of the adjacent fused parts 12, 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. The nonwoven fabric 1 pays attention to one constituent fiber 11, and preferably has one large-diameter portion 17 between adjacent fused portions 12, 12 from the viewpoint of improving the touch and reducing the strength of the nonwoven fabric. 5 or less, more preferably 1 or more and 3 or less.

The ratio (L ₁₆ / L ₁₇ ) of the fiber diameter (diameter L ₁₆ ) of the small diameter portion 16 to the fiber diameter (diameter L ₁₇ ) of the large diameter portion 17 is preferably 0.5 or more and 0.8 or less, more preferably 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 and 28 μm or less, more preferably 6.5 μm or more and 20 μm or less, and particularly preferably 7.5 μm or more and 16 μm or less from the viewpoint of improving the touch. is there. The fiber diameter (diameter L ₁₇ ) of the large diameter portion 17 is 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 from the viewpoint of improving the touch.
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.

  In addition, as shown in FIG. 5, the nonwoven fabric 1 focuses on one of the constituent fibers 11 of the constituent fibers 11 of the nonwoven fabric 1, and moves from the small diameter portion 16 adjacent to the fused portion 12 to the large diameter portion 17. It is preferable that the change point 18 is arranged within a range of １ ／ of the interval T between the fusion parts 12, 12 adjacent to the fusion part 12. Here, the change point 18 of the nonwoven fabric of the present invention is continuously from the small diameter portion 16 extending with a small fiber diameter to the large diameter portion 17 extending with a fiber diameter larger than the small diameter portion 16. It means a part where the fiber diameter changes extremely in one step without including a part that gradually changes or a part that continuously changes over a plurality of stages. Moreover, when the said one component fiber 11 is a heat | fever extensible composite fiber, the change point 18 of the nonwoven fabric of this invention is the 1st resin component which comprises a core part, and 2nd resin which comprises a sheath part. It does not include a state in which the fiber diameter is changed by peeling between the components, and it means a part where the fiber diameter is changed by stretching.

  Further, the fact that the changing 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 1 are randomly extracted. As shown in FIG. 5, the constituent fiber 11 is made of JCM-5100 (trade name) manufactured by JEOL Ltd. as a scanning electron microscope. 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 1 in which the changing point 18 is disposed within a range of 1/3 of the interval T between the adjacent fused portions 12, 12 from the fused portion 12 is the number of the constituent fibers 11 of the non-woven fabric 1 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 the touch, it is preferably 1 or more, more preferably 5 or more, and particularly preferably 10 or more.

  As shown in FIG. 4, the nonwoven fabric 1 is composed of a top region 13 a, a bottom region 13 b, and a side region 13 c positioned therebetween when the nonwoven fabric 1 is viewed in cross section along the thickness direction Z. The top region 13a, the bottom region 13b, and the side region 13c extend continuously in one direction (X direction) of the nonwoven fabric 1. The top region 13a, the bottom region 13b, and the side region 13c, when the nonwoven fabric 1 is viewed in a cross-section along the thickness direction Z, divides the thickness of the nonwoven fabric 1 in the Z direction into three equal parts, The top region 13a is distinguished from the central region as the side region 13c and the lower region as the bottom region 13b.

  As will be described later, the nonwoven fabric 1 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 longitudinal direction X of the nonwoven fabric 1 described above is the same direction as the machine direction (MD, flow direction) when the nonwoven fabric 1 is manufactured by performing uneven processing on the fiber sheet 1a (see FIG. 8). The direction Y orthogonal to the X direction is the same direction as the orthogonal direction (CD, roll axis direction) orthogonal to the machine direction (MD, flow direction).

As shown in FIG. 4, when the nonwoven fabric 1 is observed along the thickness direction Z, the fiber density of the side region 13c is lower than the fiber density of the top region 13a and the fiber density of the bottom region 13b. The fiber density is the number of fibers per unit area in the cross section of the nonwoven fabric 1. Therefore, the side region 13c is a sparse region in which the number of fibers is small (the interfiber distance is large) compared to the top region 13a and the bottom region 13b.
And as for the nonwoven fabric 1, as shown in FIG. 3, 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 recessed part 14 is formed from the bottom part area | region 13b. Therefore, the ridges 13 of the nonwoven fabric 1 constituting the top sheet 2 each have a side region 13c on both sides sandwiching the top region 13a, and the top region 13a between the top region 13a and the joint 14s. A side region 13c having a lower fiber density is formed.
Due to the fact that the fiber density of the side region 13c is lower than the top region 13a or the top region 13a and the bottom region 13b, the liquid that has entered between the ridges 13 is projected via the side regions 13c. It moves to the inside of the hollow space under the part 13 or the second sheet 6, and the transferred liquid is unlikely to return to the top region 13 a that forms a surface in contact with the skin. Thereby, the discomfort etc. by excretion fluid contacting a wearer's skin can be prevented more reliably.

The ratio (D _13c / D _13a , D _13c / D _13a ) of the fiber density (D _13c ) of the side region 13c to the fiber density (D _13a ) in the top region 13a or the fiber density (D _13b ) in the bottom region 13b ) Is preferably 0.15 or more and 0.9 or less, more preferably 0.2 or more and 0.8 or less. Specifically, the specific value of the fiber density of the nonwoven fabric 1 is such that the fiber density (D _13a ) in the top region 13a is preferably 90 / mm ² or more and 200 / mm ² or less, more preferably 100 / mm ² or more 180 lines is / mm ² or less. Also, the fiber density _{(D 13b)} at the bottom area 13b is preferably 80 present / mm ² or more 200 present / mm ² or less, more preferably 90 present / mm ² or more 180 lines / mm ² or less. The fiber density of the side region 13c _{(D 13c)} is preferably 30 lines / mm ² or more eighty / mm ² or less, more preferably 40 present / mm ² or more 70 yarns / mm ² or less. The method for measuring the fiber density is as follows.

[Measuring method of fiber density in top region 13a, bottom region 13b and side region 13c]
The nonwoven fabric is cut along the thickness direction Z using a feather razor (product number FAS-10, manufactured by Feather Safety Razor Co., Ltd.). Regarding the fiber density in the top region 13a, the top region 13a, which is the upper part when the thickness of the cut surface of the nonwoven fabric is divided into three equal parts in the Z direction, is magnified using a scanning electron microscope (fiber cross section is 30 to 30). The magnification is adjusted so that about 60 fibers can be measured (150 to 500 times), and the number of cross-sections of fibers cut by the cut surface per fixed area (about 0.5 mm ² ) is counted. 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 lower part when the thickness of the cut surface of the nonwoven fabric is divided into three equal parts in the Z direction. Similarly, the fiber density of the side region 13c is obtained by measuring the central portion when the thickness of the cut surface of the nonwoven fabric is divided into three equal parts in the Z direction. Note that JCM-5100 (trade name) manufactured by JEOL Ltd. is used as the scanning electron microscope.

In the nonwoven fabric 1, the number of fibers having change points in the constituent fibers constituting the side region 13c constitutes the number of fibers having change points 18 in the constituent fibers constituting the top region 13a, and the bottom region 13b. More than the number of fibers having the change point 18 in the constituent fibers is formed. 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 _13a ) or the number of fibers having the change point 18 in the component fibers constituting the bottom region 13b (N _13b ) The ratio (N _13c / N _13a , N _13c / N _13b ) of the number (N _13c ) of fibers having changing points in the constituent fibers to be formed is preferably 2 or more and 20 or less, more preferably 5 or more and 20 or less. Specifically, regarding the specific value of the number of fibers having the change point 18 of the nonwoven fabric 1, the number of fibers having the change point 18 (N _13a ) in the constituent fibers constituting the top region 13a is preferably one or more. 15 or less, more preferably 5 or more and 15 or less. Further, the number (N _13b ) of fibers having the change point 18 in the constituent fibers constituting the bottom region 13b is preferably 1 or more and 15 or less, more preferably 5 or more and 15 or less. Further, the number (N _13c ) of fibers having the change point 18 in the constituent fibers constituting the side region 13c is preferably 5 or more and 20 or less, 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]
Regarding the number of fibers having the change point 18 in the constituent fibers 11 constituting the top region 13a, the vicinity of the top of the top region 13a, which is an upper part when the thickness of the nonwoven fabric is divided into three equal parts in the Z direction, The fiber cross section is enlarged (adjusted to a magnification capable of measuring about 30 to 60 fiber cross sections; 50 to 500 times), 20 constituent fibers 11 constituting the top region 13a are randomly extracted, and 20 constituent fibers 11 are extracted. The number of fibers having the change point 18 in the is counted. 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 bottom region 13b, which is a lower part 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 thickness of the nonwoven fabric 1, the entire thickness of when the side view of the nonwoven fabric 1 and the sheet thickness T _S, the local thickness of the nonwoven fabric 1 that is curved to the irregularities and the layer thickness T _L. Sheet thickness _{T S} is preferably 0.5mm or more 7mm or less, more preferably 5mm or 1.0 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.

Layer thickness _{T L} may be different at each site in the non-woven fabric 1 is preferably a layer thickness _{T L1} of the top region 13a is 0.1mm or more 3.0mm or less, 0.2 mm or more 2.0mm or less Is more preferable. The layer thickness T _L2 of the bottom region 13b is preferably 0.1 mm or greater and 3.0 mm or less, and more preferably 0.2 mm or greater and 2.0 mm or less. The layer thickness T _L3 of the side region 13c is preferably 0.1 mm or greater and 3.0 mm or less, and more preferably 0.2 mm or greater and 2.0 mm or less. The relationship between the layer thicknesses T _L1 , T _L2 , and T _L3 is within this range, so that the body fluid absorption speed during use is fast, the liquid return from the absorber is suppressed, and an appropriate cushioning property is realized. it can.

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 1 is 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.
Layer thickness T _L of assay, by expanding the cross section of the sheet by Keyence digital microscope VHX-900 by about 20 times, to measure the thickness of each layer.

When the nonwoven fabric 1 is viewed in plan, the pitch between the tops of the ridges 13 adjacent in the Y direction is preferably 1 mm or more and 15 mm or less, and more preferably 1.5 mm or more and 10 mm or less. The height H (see FIG. 3) of the ridge 13 is preferably 0.5 mm to 5 mm, and more preferably 1 mm to 3 mm. The height H is measured under a no load by observing a cross section in the thickness direction Z of the nonwoven fabric 1 with a microscope.
The basis weight of the nonwoven fabric 1 is preferably 15 g / ^{m 2} or more 50 g / ^{m 2} or less the average value of the entire sheet, 20 g / ^{m 2} or more 40 g / ^{m 2} or less is more preferable.

A small amount of fiber treatment agent such as fiber colorant, antistatic property agent, lubricant, hydrophilic agent may be adhered to the surface of the constituent fiber 11 of the nonwoven fabric 1 at the raw material stage.
As a method for attaching the fiber treatment agent to the surface of the constituent fiber 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.

  As shown in FIGS. 2 and 3, the top sheet 2 in the incontinence pad 10 of the present embodiment is a second sheet 6 as an adjacent lower sheet in each of the concave portions 14 of the nonwoven fabric 1 constituting the top sheet 2. And are joined by thermal fusion. The lower sheet in the present embodiment is a second sheet 6 made of an aggregate of thermoplastic resin fibers disposed between the top sheet 2 and the absorber 4. As the aggregate of thermoplastic resin fibers, a nonwoven fabric can be generally used.

The concave strip portion 14 of the surface sheet 2 is continuously joined to the second sheet 6 along the longitudinal direction of the incontinence pad 10 as shown in FIG. 3 and the nonwoven fabric 1 made of thermoplastic resin fibers. The joining portion 14s extends over the entire longitudinal direction of the portion where the top sheet 2 and the second sheet 6 overlap. As shown in FIG. 6, by continuously joining the concave strip portion 14 of the top sheet 2 and the second sheet 6, the liquid that has migrated onto the second sheet 6 below the convex strip portion 13 is transferred to the adjacent convex strip portion. 13 can be efficiently diffused in the longitudinal direction X while preventing the downward movement. Therefore, the absorption capacity in a wide range in the longitudinal direction of the absorbent body 4 can be more effectively utilized while more reliably suppressing the discomfort caused by the excretion fluid coming into contact with the wearer's skin.
However, it is not hindered to form the top sheet 2 and the second sheet 6 intermittently along the longitudinal direction X.

In the incontinence pad 10, the top sheet 2 and the second sheet 6, more specifically, the non-woven fabric 1 constituting the top sheet 2 and the aggregates of fibers constituting the second sheet 6 each include fibers of thermoplastic resin. In the joint portion 14s described above, the concave strip portion 14 of the topsheet 2 and the second sheet 6 are integrally heat-pressed and heat-sealed by heat sealing.
In the joining part 14s by heat fusion, neither the constituent fiber of the nonwoven fabric 1 constituting the top sheet 2 nor the constituent fiber of the assembly of fibers constituting the second sheet 6 may maintain the fiber form. preferable. In order not to maintain the form of the fiber, it is preferable that the heating temperature by heat sealing is equal to or higher than the melting point of the constituent fibers of one or both of the nonwoven fabric and the fiber assembly. The melting point of the constituent fiber in the case of a composite fiber composed of two components having different melting temperatures is the melting point of the component having the lowest melting point.
Since the joining portion 14s has such a configuration, the liquid that has migrated onto the second sheet 6 under the ridge 13 is efficiently diffused in the longitudinal direction X while preventing the liquid from moving under the adjacent ridge 13. Can be made. Therefore, the absorption capacity in a wide range in the longitudinal direction of the absorbent body 4 can be more effectively utilized while more reliably suppressing the discomfort caused by the excretion fluid coming into contact with the wearer's skin.

Moreover, it is preferable that the joining part 14s of the concave line part 14 and the second sheet 6 (lower sheet) is liquid-impermeable. The liquid impermeability here means that the liquid does not pass through the top sheet 2 or the second sheet 6.
Examples of the method for forming the liquid-impermeable joining portion 14s include a method in which the topsheet 2 and the second sheet 6 are heat-sealed so that the constituent fibers of both do not maintain the fiber form.

Instead of joining the top sheet 2 to the lower sheet such as the second sheet 6 by thermal fusion, the second sheet 6 (lower sheet) may be joined by other joining means such as joining with an adhesive such as a hot melt adhesive. ).
The joining of the top sheet 2 and the second sheet 6 is not limited to the above-described heat fusion, and other joining means such as joining with an adhesive such as a hot melt adhesive may be employed. The second sheet 6 can be made shorter in the longitudinal direction X and the width direction Y than the top sheet 2. Alternatively, the length of the second sheet 6 in the longitudinal direction X and the width direction Y can be the same as that of the top sheet 2.

  Nonwoven fabrics obtained by various production methods can be used as the aggregate of thermoplastic resin fibers constituting the second sheet 6. For example, an air-through nonwoven fabric in which heat-bonding points between fibers are formed on a fiber web obtained by the card method or airlaid method, and a heat-bonding point between fibers is formed on a fiber web obtained by the card method by a heat roll method. Various nonwoven fabrics such as heat roll nonwoven fabric, heat embossed nonwoven fabric, spun lace nonwoven fabric, needle punched nonwoven fabric, and resin bonded nonwoven fabric can be used.

The non-woven fabric constituting the second sheet 6 is preferably a long-fiber non-woven fabric in which the constituent fibers are oriented in the longitudinal direction X. The long fiber nonwoven fabric is a nonwoven fabric composed of long fibers, and examples thereof include a spunbond nonwoven fabric and a spunlace nonwoven fabric.
Moreover, as a nonwoven fabric which comprises the second sheet | seat 6, nonwoven fabrics other than a long-fiber nonwoven fabric can also be used, for example, various constituents, such as a heat roll nonwoven fabric, a heat embossed nonwoven fabric, a spunlace nonwoven fabric, in which the constituent fibers are oriented in the longitudinal direction X Nonwoven fabrics can also be used. About these nonwoven fabrics, whether the constituent fibers are oriented in the longitudinal direction X can be determined by the following method.
The degree of orientation of the fiber is measured as a MOR value with a microwave molecular orientation meter MOA-6004 (manufactured by Oji Scientific Instruments). The degree of orientation of the fiber is an average value of 5 samples.

  By orienting the constituent fibers of the second sheet 6 in the longitudinal direction X, the liquid that has moved to the hollow space under the ridge 13 or the second sheet 6 moves under the ridge 13 to the adjacent ridge 13. It becomes easier to diffuse in the longitudinal direction without causing side leakage and stickiness.

In the incontinence pad 10 of the present embodiment, the fiber density of the aggregate of the fibers that constitute the second sheet 6 is higher than the fiber density of the nonwoven fabric 1 that constitutes the top sheet 2.
In the case of having a plurality of regions having different fiber densities in the thickness direction as in the nonwoven fabric 1 used in the present embodiment, the fiber density (D _13a ) of the nonwoven fabric constituting the top sheet 2 is the fiber at the top of the ridge 13. Density. Also, the fiber density of the fiber aggregate constituting the second sheet 6 (D _6), the nonwoven fabric constituting the top sheet 2 and the fiber density in the non-bonded portion 6a which is not joined.

The fiber density (D13a) at the top of the ridge 13 is measured in the same manner as the fiber density in the top region 13a. The fiber density (D ₆ ) of the aggregate of fibers constituting the second sheet 6 is also the thickness of the aggregate of fibers constituting the second sheet 6 using a feather razor (part number FAS-10, manufactured by Feather Safety Razor Co., Ltd.). Except for cutting along the direction Z and magnifying the cut surface at the non-joint portion in the fiber assembly, as described above [Method for measuring fiber density in the top region 13a, the bottom region 13b, and the side region 13c] Cut in the same way. The fiber density of the non-joined portion 6a of the second sheet 6 is preferably measured by observing the cut surface of the second sheet 6 at a portion facing the top (top region 13a) of the ridge 13.

Top of the convex portion with respect to the fiber density of the (top area _{13a) (D} 13a), the ratio of the fiber density of the second sheet _{6 (D 6) (D 13a} / D 6) is preferably 1.1 or more, more preferably 2 or more.

As shown in FIGS. 1A and 2B, the absorbent body 4 in the incontinence pad 10 of the present embodiment has high-density portions 43 formed at a plurality of locations in the width direction Y by embossing. Yes. The high density portion 43 is formed so as to have a higher density than the portions 44 and 44 (hereinafter also referred to as a low density portion 44) located on both sides in the width direction, and extend in the longitudinal direction X, respectively. That is, in the absorbent body 4, the high density portions 43 and the low density portions 44 are alternately arranged.
Moreover, each of the high density part 43 is formed in the position which overlaps with the top part of the protruding item | line part 13, as shown to Fig.2 (a). More specifically, the high-density portion 43 extends in the longitudinal direction X and is formed in a plurality of rows in the width direction Y. Each of the high-density portions 43 is continuous with the top of the ridge 13 along the longitudinal direction X. Are overlapping.
The high density portion 43 in the present embodiment is formed by pressing between an embossing roll provided with a convex portion and a groove portion alternately extending in the circumferential direction or the axial direction and an anvil roll having a smooth surface on the circumferential surface. And in each high-density part 43, the thickness of the absorber 4 is thin compared with the other part. Moreover, the non-skin contact surface side surface of the absorber 4 is a surface on the embossing roll side, and the high density portion 43 is formed on the non-skin contact surface side surface of the absorber 4 on the embossing roll circumferential surface. It has a recess corresponding to the ridge.

The high density portion 43 may be formed only by pressurization, but may be formed by heating simultaneously with pressurization.
The number of high-density portions 43 formed in the width direction Y of the absorbent body 4 and overlapping with the tops of the ridges 13 of the topsheet 2 is plural, preferably 3 or more, more preferably 5 or more, and further Preferably it is 8 or more.
The high-density portion 43 has a length in the width direction Y of preferably 20 mm or more, more preferably 50 mm or more. Further, the high-density portion 43 has a continuous length in the longitudinal direction X of preferably 30% or more, more preferably 50% or more, and still more preferably 100% with respect to the total length in the same direction of the absorbent body 4. It is.
Moreover, the high-density part 43 may be formed continuously in the longitudinal direction X of the absorbent body 4 as shown in FIG. Alternatively, the long, high-density portions 43 may be intermittently formed along the longitudinal direction X of the absorber 4. In that case, the length L3 of the high-density portion 43 in the longitudinal direction X is preferably 0.5 mm or more, more preferably 1 mm or more, and the length L3 of the high-density portion 43 is equal to the length L3. It is preferably 5% or more, more preferably 30% or more of the total length L5 with the length between the high-density portions 43 and 43 adjacent to each other in the longitudinal direction X.

The ratio (D ₃ / D ₄ ) of the density (D ₄ ) of the low density portion 44 to the density (D ₃ ) of the high density portion 43 is preferably 1.5 or more, and more preferably 3 or more. The density of the high-density part 43 and the low-density part 44 is narrow from the absorbent body 4 to the entire region in the thickness direction from the absorber 4 using a feather razor (part number FAS-10, manufactured by Feather Safety Razor Co., Ltd.). Each sample is cut out, the mass of each sample is measured, and the measured mass is obtained by dividing the measured area by the volume calculated by multiplying the planar view area by the thickness of the sample. The thickness of the sample is measured under no load before cutting out from the absorber.

According to the incontinence pad 10 of the present embodiment, the top sheet 2 is composed of the nonwoven fabric 1 having a concavo-convex structure having the ridges 13 and the ridges 14 extending in the longitudinal direction X, and the second sheet 6 is configured. Since the fiber density of the aggregate of fibers is higher than the fiber density of the nonwoven fabric 1, when the liquid A such as urine is supplied to the skin contact surface side, the liquid A is, as shown in FIG. 13 quickly enters between the two sides of the top of the ridge 13, particularly from the side region 13 c described above, onto the second sheet 6 below the ridge 13.
And the liquid B which has moved on or in the second sheet 6 under the ridge 13 has a difference in density between the nonwoven fabric 1 and the second sheet 6, and the recess 14 is joined to the second sheet 6. Since the hollow structure inside the ridge 13 is easily maintained during wearing, it is difficult to return to the portion of the ridge 13 in contact with the skin. Thereby, the discomfort due to the excretion fluid coming into contact with the skin of the wearer can be more reliably suppressed.

  From the viewpoint of achieving such an effect, the hydrophilicity of the second sheet 6 (lower sheet) is preferably higher than that of the top sheet 2. The hydrophilicity of the second sheet 6 and the hydrophilicity of the top sheet 2 are determined by measuring the contact angle of water with the fibers constituting the second sheet 6 and the contact angle of water with the constituent fibers of the nonwoven fabric 1 constituting the top sheet 2. It is determined that the hydrophilicity of the smaller corner is small.

Moreover, according to the incontinence pad 10 of this embodiment, since it has the high-density part 43 in the part which overlaps with the top part (top part area | region 13a) of the protruding item | line part 13 of the nonwoven fabric 1, in the absorber 4, it is below the protruding item | line part 13. The liquid B transferred onto the second sheet 6 is absorbed by the high density portion 43 after flowing along the longitudinal direction X on the low density portion 44.
Thereby, the absorption capacity of the wide range of the longitudinal direction of the absorber 4 can be utilized effectively, suppressing the discomfort by excretion liquid contacting a wearer's skin reliably.

  It is preferable that the second sheet 6 and the absorbent body 4, the absorbent sheet constituting the absorbent body 4, and the absorbent body 4 and the back sheet 3 are joined with an adhesive, respectively. When the members are joined with an adhesive, solid coating with a slot coater or the like may be used, but pattern coating is preferred. Preferable examples of the pattern coating application include spiral patterns, dot patterns, stripe patterns (striped patterns), lattice patterns, checkered patterns, and the like.

  In the incontinence pad 10 of the present embodiment, the nonwoven fabric 1 used as the top sheet 2 is a fusion that forms a fiber sheet by thermally fusing the intersections of the constituent fibers of the fiber web containing high elongation fibers at the fusion part. It is suitably manufactured by a method for manufacturing a nonwoven fabric comprising a step and a stretching step of stretching the fiber sheet in one direction. One embodiment of the method for producing the nonwoven fabric 1 used as the top sheet 2 will be described with reference to FIG. FIG. 8 schematically shows a preferable manufacturing apparatus 100 used in the method for manufacturing the nonwoven fabric 1. 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, an extending unit 400, and a lower sheet joining unit 500 in this order from the upstream side to the downstream side of the manufacturing process.

  As shown in FIG. 8, the web forming unit 200 includes a web forming apparatus 201. 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. Instead of the card machine, other web manufacturing apparatuses such as airlaid apparatuses can be used.

  As shown in FIG. 8, the hot air processing unit 300 includes a hood 301. 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 1b are heat-sealed. More specifically, the temperature of the hot air is preferably adjusted to a temperature higher by 0 ° C. to 30 ° C. than the melting point of the resin having the lowest melting point among the constituent fibers 11 of the fiber web 1b. The heat treatment time is preferably adjusted to 1 to 5 seconds according to the temperature of the hot air. Moreover, it is preferable that the wind speed of a hot air is about 0.3 m / sec-1.5 m / sec from a viewpoint of encouraging the further entanglement of the constituent fibers 11. Moreover, it is preferable that a conveyance speed is about 5 m / min-100 m / min.

  The extending | stretching part 400 is provided with a pair of uneven | corrugated roll 401,402 which can mutually mesh | engage as shown in FIG.8 and FIG.9. 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. is there. For example, when the core / sheath fiber is used as the fiber, 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. 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. 9, 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 stretching and extending the previously described small-diameter portion to the large-diameter portion adjacent to the fusion-bonded portion to improve the touch, it is preferably 1 mm or more and 10 mm or less, particularly preferably 1.5 mm or more. 8 mm or less. From the same viewpoint, as shown in FIG. 10, the pushing 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 to each other in the roll axis direction) is The thickness is preferably 1 mm or more and 3 mm or less, and particularly preferably 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 and 3.0 times or less, and particularly preferably 1.7 times or more and 2.8 times or less.

  The lower sheet bonding portion 500 includes a concavo-convex roll 402 and a flat roll 501 having a smooth surface, and has a concavo-convex shape between the large-diameter convex portion 404 of the concavo-convex roll 402 and the peripheral surface of the flat roll 501. The nonwoven fabric 1 and the second sheet 6 (lower sheet) are joined by heating and pressing.

The manufacturing method of the nonwoven fabric 1 using the manufacturing apparatus 100 which has the above structure is demonstrated.
First, as shown in FIG. 8, in the web forming unit 200, a short fiber-shaped constituent fiber 11 having a heat-extensible composite fiber that is a high elongation fiber is used as a raw material, and a web forming apparatus 201 that is a card machine is used. A fiber web 1b is formed (web forming step). The fiber web 1b manufactured by the web forming apparatus 201 is in a state where its constituent fibers 11 are loosely entangled with each other, and has not yet achieved shape retention as a sheet.

  Next, as shown in FIG. 8, the fiber sheet 1 a is formed by thermally fusing the intersections of the constituent fibers 11 of the fiber web 1 b including the high elongation fibers at the fusion part 12 (fusing step). Specifically, the fiber web 1b 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 1b are further entangled, and at the same time, the intersection of the entangled fibers is thermally fused (see FIG. 10 (a)) to form a sheet-like shape. A fiber sheet 1a having shape retention is produced.

  Next, as shown in FIG. 8, the fused fiber sheet 1a is stretched in one direction (stretching step). Specifically, the fused fiber sheet 1a having a shape-retaining property as a sheet is conveyed between a pair of concavo-convex rolls 401 and 402, as shown in FIGS. 10 (a) to 10 (c). In addition, the fiber sheet 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 be 1/3 of the interval T between the fusion portions 12 and 12 adjacent to the fusion portion 12. Form within the range. Specifically, as shown in FIG. 10A, 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 sheet 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. 10B, local contraction is likely to occur first in the vicinity of each fusion part 12 that fixes the constituent fibers 11, and 1 between 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 first 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.

  And about the one component fiber 11 between some adjacent fusion | melting parts 12 and 12, as shown in FIG.10 (c), in the state which left the room (extension margin) which can be extended | stretched, further 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 a plurality of small diameter portions 16 are formed in the large diameter portion 17. become.

  In the stretching step, the small diameter portion 16 and the large diameter portion 17 are formed from the high elongation fiber, and at the same time, the large diameter convex portion 403 of the concave / convex roll 401 and the large diameter convex portion of the concave / convex roll 401 in the fiber sheet 1a. A portion located between the portions 404 is extended more than other portions. In this case, since the constituent fiber of the fiber sheet 1a is a high elongation fiber, even if it is stretched, it is not cut and is successfully stretched. The part located between the large diameter convex part 403 of the uneven | corrugated roll 401 and the large diameter convex part 404 of the uneven | corrugated roll 401 among the fiber sheets 1a is the side area 13c of the protruding item | line part 13 in the target nonwoven fabric 1. FIG. Therefore, the fiber distance is not cut in the side region 13c by the above-described stretching, and the inter-fiber distance is increased as compared to before stretching. As a result, the fiber density of the side region 13c is lower than other parts, and air permeability is improved. And since the cut | disconnection has not arisen in the fiber which comprises the side part area | region 13c, the intensity | strength of the protruding item | line part 13 is maintained at a high level. As a result, even if a load is applied to the ridge 13, the ridge 13 is not easily crushed.

The nonwoven fabric 1 manufactured as described above is conveyed to the sheet joining portion of the lower sheet joining portion 500 while being deformed into the uneven shape by the uneven roll 402. The sheet joining portion is supplied with the strip-shaped nonwoven fabric 6 for the second sheet unwound from the roll-shaped roll 6 ′, and the uneven nonwoven fabric 1 is in a state of being overlapped with the strip-shaped nonwoven fabric 6. Introduced between the uneven roll 402 and the flat roll 501. Between the concave-convex roll 402 and the flat roll 501, the concave strip portion and the strip-shaped nonwoven fabric 6 in the concave-convex nonwoven fabric 1 are between the large-diameter convex portion 404 of the concave-convex roll 402 and the peripheral surface of the flat roll 501. To be joined by being heated and pressurized. In this manner, the topsheet 2 made of nonwoven fabric 1, the composite sheet 8 0 of the strip joined to the second sheet 6 can be obtained in the concave portion 14. Composite sheet 8 0 of the strip, after winding, or is introduced into the production line of the incontinence pad 10, without winding up, is introduced into the production line of the incontinence pad 10.

As mentioned above, although this invention was demonstrated based on the preferable embodiment, the absorbent article of this invention is not restrict | limited to this embodiment mentioned above at all, and can be changed suitably. For example, the above embodiment is an example in which the present invention is applied to the incontinence pad 10, but instead, the present invention is applied to other absorbent articles such as sanitary napkins, panty liners, and disposable diapers. Also good.
In addition, the second sheet 6 made of a nonwoven fabric may have the same or shorter length in one or both of the longitudinal direction X and the width direction Y of the absorbent article. Moreover, the absorbent article may not have a leak-proof cuff.

  Moreover, the absorber in this invention may be comprised from the absorbent sheet 42 like the absorber 4 shown in FIG. The absorbent body 4 shown in FIG. 12 is composed of a laminate in which an absorbent sheet 42 is laminated in two or more layers. The laminate of two or more layers may be a laminate obtained by folding a single absorbent sheet and bonding the layers between them, or by laminating multiple sheets of absorbent sheets. Things can be used. Moreover, it is good also as an absorber by which an additional absorptive sheet | seat was distribute | arranged to the interlayer of one or more layers of a laminated body of two or more layers, and one part was made thick. As the absorbent sheet, an absorbent sheet containing a fiber material and a water-absorbing polymer is preferably used. In addition, as the absorbent sheet, the constituent fibers and the constituent fibers and the water-absorbing polymer are bonded to each other through an adhesive force generated in the water-absorbing polymer in a wet state or a binder such as an adhesive or an adhesive fiber added separately. A sheet or the like can be preferably used. Further, as an absorbent sheet, an absorbent sheet manufactured by the method described in JP-A-8-246395, a pulverized pulp supplied in an air stream, and a water-absorbing polymer are deposited, and then an adhesive (for example, vinyl acetate) is deposited. A dry sheet solidified with an adhesive, PVA, etc.), an absorbent sheet obtained by applying a hot-melt adhesive between paper and non-woven fabric and then spraying a superabsorbent polymer, spunbond or melt blown non-woven fabric An absorbent sheet obtained by blending a highly water-absorbing polymer during the process can also be used. These absorbent sheets can also be used as an absorber having a single layer structure without being laminated in two or more layers. In addition, the layers between the layers may not be bonded.

This invention discloses the following absorbent articles further regarding embodiment mentioned above.
<1>
A liquid permeable top sheet that forms a skin contact surface, a back sheet and an absorbent article interposed between both sheets, and an absorbent article having a longitudinal direction and a width direction,
The top sheet is composed of a nonwoven fabric having a concavo-convex structure in which strip-like ridges and recesses extending in the longitudinal direction are alternately arranged in the width direction, and is joined to the adjacent lower sheet in the recesses, The protruding line portion has a hollow structure between the lower sheet,
The lower sheet comprises an aggregate of fibers, and the fiber density of the aggregate of fibers is higher than the fiber density of the nonwoven fabric constituting the top sheet.

<2>
The absorbent article according to <1>, wherein the constituent fibers of the lower sheet are oriented in the longitudinal direction.
<3>
The absorbent article according to <1> or <2>, wherein the lower sheet is made of a long-fiber nonwoven fabric.
<4>
The absorbent article according to any one of <1> to <3>, wherein the hydrophilicity of the lower sheet is higher than that of the top sheet.
<5>
The thickness of the absorber is preferably 1 mm or more, more preferably 2 mm or more, and preferably 15 mm or less, more preferably 10 mm or less, preferably 1 mm or more and 15 mm or less, more preferably 2 mm or more and 10 mm or less. The absorbent article according to any one of <1> to <4>.

<6>
The absorbent article according to any one of <1> to <5>, wherein the nonwoven fabric includes fibers having a large diameter portion and a small diameter portion having different fiber diameters.
<7>
The absorbent article according to any one of <1> to <6>, wherein the nonwoven fabric includes a plurality of fusion parts formed by heat-sealing intersections between constituent fibers.
<8>
The absorbent article according to any one of <1> to <7>, wherein the constituent fibers of the nonwoven fabric include high elongation fibers.
<9>
The absorbent article according to <8>, wherein the high elongation fiber is a core-sheath type composite fiber having heat-fusibility.
<10>
The absorption according to <8> or <9>, wherein the fineness of the high elongation fiber is 1.0 dtex or more and 10.0 dtex or less, preferably 2.0 dtex or more and 8.0 dtex or less at the raw material stage. Sex goods.
<11>
The absorption according to any one of <8> to <10>, wherein the proportion of the high elongation fiber in the nonwoven fabric is 50% by mass or more and 100% by mass or less, preferably 80% by mass or more and 100% by mass or less. Sex goods.

<12>
The constituent fiber of the non-woven fabric has a large-diameter portion with a large fiber diameter sandwiched between two small-diameter portions with a small fiber diameter between adjacent fused portions when focusing on one constituent fiber. The absorbent article according to any one of <1> to <11>.
<13>
The absorbent fiber article according to <12>, wherein the one constituent fiber includes a plurality of large-diameter portions between adjacent fused portions.
<14>
The constituent fibers of the non-woven fabric are provided with one or more large diameter portions of not less than one, preferably not less than one and not more than three, between adjacent fused portions when paying attention to one constituent fiber 11. The absorbent article according to <12> or <13>.
<15>
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 and 0.8 or less, and more preferably 0.8. The absorbent article according to any one of <12> to <14>, which is 55 or more and 0.7 or less.

<16>
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 and 0.8 or less, more preferably 0. The absorbent article according to any one of <12> to <15>, which is from .55 to 0.7.

The fiber diameter (diameter L ₁₆ ) of the small diameter portion is preferably 5 μm or more and 28 μm or less, more preferably 6.5 μm or more and 20 μm or less, and particularly preferably 7.5 μm or more and 16 μm or less, <12> to <16> The absorbent article according to any one of 1.
<18>
The fiber diameter (diameter L ₁₇ ) of the large diameter portion is 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, any one of <12> to <17> 2. The absorbent article according to 1.
<19>
When the constituent fibers of the nonwoven fabric are focused on one constituent fiber, the change point from the small diameter portion adjacent to the fusion portion to the large diameter portion is the interval T between the fusion portions adjacent to the fusion portion. The absorbent article according to any one of <12> to <18>, which is disposed within a range of 1/3 of the above.

<20>
The non-woven fabric has a top region, a bottom region, and a side region located between these when viewed in cross-section along the thickness direction Z,
The absorbent article according to any one of <1> to <19>, wherein the top of the ridge is formed from a top region and the bottom of the concave is formed from a bottom region.
<21>
The absorbent article according to <20>, wherein the fiber density in the side region is lower than the fiber density in the top region and the fiber density in the bottom region.
<22>
The ratio (D _13c / D _13a , D _13c / D _13a ) of the fiber density (D _13c ) in the side area to the fiber density (D _13a ) in the top area or the fiber density (D _13b ) in the bottom area ) Is preferably 0.15 or more and 0.9 or less, more preferably 0.2 or more and 0.8 or less, according to <20> or <21>.
<23>
Fiber density at the top region 13a _{(D 13a)} is preferably 90 present / mm ² or more 200 present / mm ² or less, 180 lines / mm ² or less and more preferably 100 / mm ² or more, the <20 The absorbent article according to any one of> to <22>.
<24>
Fiber density at the bottom area 13b _{(D 13b)} is preferably 80 present / mm ² or more 200 present / mm ² or less, more preferably 90 present / mm ² or more 180 lines / mm ² or less, the <20 The absorbent article according to any one of> to <23>.
<25>
Fiber density of the side region 13c _{(D 13c)} is preferably 30 lines / mm ² or more eighty / mm ² or less, more preferably 40 present / mm ² or more 70 yarns / mm ² or less, the <20 The absorbent article according to any one of> to <24>.

<26>
The number of fibers having change points in the constituent fibers constituting the side region is the number of fibers having change points in the constituent fibers constituting the top region, and the change in the constituent fibers constituting the bottom region. The absorbent article according to any one of <29> to <35>, wherein the absorbent article is formed more than the number of fibers having points.
<27>
The side region is configured with respect to the number of fibers (N _13a ) having change points in the constituent fibers constituting the top region, or the number of fibers (N _13b ) having change points in the constituent fibers constituting the bottom region. The ratio (N _13c / N _13a , N _13c / N _13b ) of the number (N _13c ) of fibers having change points in the constituent fibers is preferably 2 or more and 20 or less, more preferably 5 or more and 20 or less. The absorbent article according to any one of 21> to <26>.
<28>
Regarding the specific value of the number of fibers having a change point of the nonwoven fabric, the number of fibers (N _13a ) having a change point in the constituent fibers constituting the top region is preferably 1 or more and 15 or less, more preferably Is 5 or more and 15 or less, The absorbent article as described in any one of the above items <21> to <27>.
<29>
Regarding the specific value of the number of fibers having the change point of the nonwoven fabric, the number of fibers (N _13b ) having the change point 18 in the constituent fibers constituting the bottom region is preferably 1 or more and 15 or less, and further The absorbent article according to any one of <21> to <28>, preferably 5 or more and 15 or less.
<30>
Regarding the specific value of the number of fibers having the change point of the nonwoven fabric, the number of fibers (N _13c ) having the change point 18 in the constituent fibers constituting the side region is preferably 5 or more and 20 or less, More preferably, the absorbent article according to any one of <21> to <29>, wherein the number is 10 or more and 20 or less.

<31>
Sheet thickness _{T S} of the nonwoven fabric is at 0.5mm or 7mm or less, preferably is less than 1.0mm 5mm or less, the <1> to absorbent article according to any one of <30>.
<32>
The absorptivity according to any one of <1> to <31>, wherein the layer thickness T _L1 of the top region is 0.1 mm to 3.0 mm, preferably 0.2 mm to 2.0 mm. Goods.
<33>
The absorptivity according to any one of <1> to <32>, wherein the layer thickness T _L2 of the bottom region is 0.1 mm to 3.0 mm, preferably 0.2 mm to 2.0 mm. Goods.
<34>
The layer thickness _{T L3} of the side area is at 0.1mm or 3.0mm or less, preferably 0.2mm or more 2.0mm or less, the <1> to absorption according to any one of <33> Sex goods.
<35>
The pitch between the tops of the ridges adjacent to each other in the width direction Y is 1 mm or more and 15 mm or less, preferably 1.5 mm or more and 10 mm or less, according to any one of <1> to <34>. Absorbent article.
<36>
The absorbent article according to any one of the above items <1> to <34>, wherein a height H of the protruding portion is 0.5 mm or more and 5 mm or less, preferably 1 mm or more and 3 mm or less.
<37>
The basis weight of the nonwoven fabric is a 15 g / ^{m 2} or more 50 g / ^{m 2} or less the average value of the entire sheet, preferably is 20 g / ^{m 2} or more 40 g / ^{m 2} or less, but more preferably, the <1> - The absorbent article according to any one of <36>.
<38>
The absorbent article according to any one of <1> to <37>, wherein the lower sheet is a spunbond nonwoven fabric or a spunlace nonwoven fabric.
<39>
The ratio (D _13a / D ₆ ) of the fiber density (D ₆ ) of the lower sheet or the second sheet, which is the lower sheet, to the fiber density (D _13a ) of the top (top region 13a) of the ridge. The absorbent article according to any one of <1> to <38>, preferably 1.1 or more, more preferably 2 or more.

<40>
The absorbent body has a high density portion at a plurality of locations in the width direction where the fiber density is higher than the portions located on both sides in the width direction, and each of the high density portions overlaps with the top of the ridge portion. The absorbent article according to any one of <1> to <38>, wherein
<41>
The high-density portion extends in the longitudinal direction and is formed in a plurality of rows in the width direction, and each of the high-density portions continuously overlaps the top of the ridge portion along the longitudinal direction. The absorbent article according to <40>.
<42>
The number of high-density portions formed in the width direction Y of the absorbent body and overlapping the tops of the ridges of the topsheet is plural, preferably 3 or more, more preferably 5 or more, and still more preferably 8 More than a book. The absorbent article as described in <40> or <41>.
<43>
The high-density part is the absorbent article according to any one of <40> to <42>, wherein the length in the width direction Y is preferably 20 mm or more, more preferably 50 mm or more.
<44>
The absorptivity according to any one of <40> to <43>, wherein as the high-density portion, a high-density portion having a shape long in the longitudinal direction X is continuously formed along the longitudinal direction X of the absorbent body. Goods.
<45>
The high-density portion has a continuous length in the longitudinal direction X of preferably 30% or more, more preferably 50% or more, and still more preferably 100% with respect to the total length in the same direction of the absorber. The absorbent article according to any one of <40> to <44>.
<46>
The absorption according to any one of <40> to <45>, wherein the high-density portion has a shape that is long in the longitudinal direction X, and a plurality of the high-density portions are intermittently formed along the longitudinal direction X of the absorbent body 4. Sex goods.
<47>
The length L3 of the high-density part in the longitudinal direction X is preferably 0.5 mm or more, more preferably 1 mm or more, and the absorbent article according to any one of the above <40> to <46>.
<48>
The length L3 of the high-density portion is preferably 5% or more, more preferably 30% or more of the total length L5 of the length L3 and the length between the high-density portions adjacent to each other in the longitudinal direction X. The absorbent article according to any one of <40> to <47>.
<49>
The ratio (D ₃ / D ₄ ) of the density (D ₄ ) of the low density part to the density (D ₃ ) of the high density part is preferably 1.5 or more, more preferably 3 or more, <40 The absorbent article according to any one of> to <48>.

<50>
The top sheet and the lower sheet include fibers of thermoplastic resin, and the concave portion is joined to the lower sheet by thermal fusion, and the top sheet and the lower sheet are joined at the joint. The absorbent article according to any one of the above items <1> to <49>, in which the constituent fibers are not maintaining the fiber form.
<51>
The absorbent article according to any one of <1> to <50>, wherein a joint portion between the concave stripe portion and the lower sheet is liquid-impermeable.
<52>
The absorbent article according to any one of <1> to <51>, wherein the joint is formed continuously in the longitudinal direction.

10 Incontinence pads (absorbent articles)
DESCRIPTION OF SYMBOLS 1 Nonwoven fabric 1a Fiber sheet 1b Fiber web 2 Top sheet 3 Back sheet 4 Absorber 6 Second sheet (lower sheet)
11 constituent fibers 12 fused portion 13 convex portion 14 concave-convex portions 14s joint 16 small diameter portion 17 large diameter portion 18 change point 43 the high density portion 100 manufacturing apparatus 200 web forming section 201 web forming apparatus 300 hot-air treatment part 400 extending portion 401, 402 Concave and convex roll 403, 404 Large diameter convex part 500 Lower sheet joint part

Claims (9)

A liquid permeable top sheet that forms a skin contact surface, a back sheet and an absorbent article interposed between both sheets, and an absorbent article having a longitudinal direction and a width direction,
The top sheet is composed of a nonwoven fabric having a concavo-convex structure in which strip-like ridges and recesses extending in the longitudinal direction are alternately arranged in the width direction, and is joined to the adjacent lower sheet in the recesses, The protruding line portion has a hollow structure between the lower sheet,
The lower sheet is made of aggregate of fibers, rather higher than the fiber density of the nonwoven fabric fiber density of the aggregate of the fibers constituting the surface sheet,
The absorbent body has a high density portion at a plurality of locations in the width direction where the fiber density is higher than the portions located on both sides in the width direction, and each of the high density portions overlaps with the top of the ridge portion. Absorbent article formed in .   The absorbent article according to claim 1, wherein the constituent fibers of the lower sheet are oriented in the longitudinal direction.   The absorptive article according to claim 2 in which said lower sheet consists of a long-fiber nonwoven fabric.   The absorptive article according to any one of claims 1 to 3 whose hydrophilicity of said lower sheet is higher than said surface sheet. The high-density portion extends in the longitudinal direction and is formed in a plurality of rows in the width direction, and each of the high-density portions continuously overlaps the top of the ridge portion along the longitudinal direction. The absorbent article according to any one of claims 1 to 4 . The top sheet and the lower sheet include fibers of thermoplastic resin, and the concave portion is joined to the lower sheet by thermal fusion, and the top sheet and the lower sheet are joined at the joint. The absorptive article given in any 1 paragraph of Claims 1-5 in which the constituent fiber of is not maintaining the form of a fiber. The absorbent article according to any one of claims 1 to 6 , wherein a joint portion between the concave strip portion and the lower sheet is liquid-impermeable. The absorptive article according to any one of claims 1 to 7 in which said joined part is formed continuously in the longitudinal direction. 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 absorbent article according to any one of claims 1 to 8 , wherein a fiber density in the side region is lower than a fiber density in the top region.

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