TW201622669A - Absorbent product - Google Patents

Abstract

An absorbent product including a front surface sheet (2) which comprises nonwoven fabric (1) having a corrugated structure composed of ridges (13) and grooves (14) extending in the longitudinal direction and disposed alternately in the width direction Y. The front surface sheet (2) has been bonded to an adjoining lower sheet (6) at the grooves (14). The nonwoven fabric (1) was formed from at least high-elongation fibers as a raw material. The lower sheet (6) comprises a mass of thermoplastic resin fibers. The ridges (13) have a hollow structure. In the ridges (13), the lateral zones (14c) have a lower fiber density than both the top zones (13a) and the bottom zones (13b).

Description

Absorbent article

The present invention relates to an absorbent article such as a menstrual napkin or disposable diaper.

As the front sheet of the absorbent article, a ridge structure having a stripe shape extending in one direction and a concave-convex structure in which the groove portions are alternately arranged in the width direction are known. For example, the present applicant has proposed a front sheet in which a sheet for forming an unevenness in which a plurality of pleated portions are formed in parallel with each other is linearly joined to a base sheet between the pleated portions (see Patent Document 1). .

Patent Document 2 describes a front sheet formed of a liquid permeable fibrous nonwoven fabric and shaped into a wave shape. The wave shape is continuously formed along the length direction of the front sheet. The top and bottom of the wave shape extend in a direction crossing the longitudinal direction of the front sheet. The wall portion between the top and bottom regions of the wave shape has a lower fiber density than the top or bottom region.

Patent Document 3 describes a front sheet having a ridge-like convex portion continuous in the longitudinal direction of the absorbent article at a predetermined interval in the width direction of the absorbent article. On both sides of each convex portion, a dot-shaped concave embossing is alternately applied to the right adjacent position and the left adjacent position at intervals in the longitudinal direction of the absorbent article, and the concave embossing is arranged in a staggered manner as a whole.

[Previous Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open Publication No. 2002-165830

Patent Document 2: Japanese Patent Laid-Open Publication No. 2008-113866

Patent Document 3: Japanese Patent Laid-Open Publication No. 2013-244256

According to the front sheet of Patent Document 1, it is possible to provide an effect of isolating the liquid having a relatively high viscosity between the crease portions and the skin of the wearer. However, further improvement is desired regarding the absorbency in the case where a large amount of urine or a liquid having a relatively low viscosity is supplied. Further, in the technique described in Patent Document 2, since the convex portion and the concave portion extending in the width direction of the absorbent article are formed on the front surface sheet, when a large amount of liquid is supplied, leakage from both ends in the width direction occurs. (so-called side leakage) or a sticky feeling on the wearer's skin.

Further, in the technique described in each of the above-mentioned patent documents, since the convex portion and the concave portion extending in either of the longitudinal direction and the width direction of the absorbent article are formed on the front sheet, the gas permeability in the direction is ensured. However, with respect to the direction orthogonal thereto, the convex portion becomes an obstacle to ventilation. As described above, in the prior art, it is difficult to ensure sufficient gas permeability in both the longitudinal direction and the width direction on the skin facing surface side of the absorbent article.

The present invention provides an absorbent article comprising a front sheet which forms a liquid permeability of a skin contact surface, a back sheet, and an absorbent body interposed between the sheets, and has a longitudinal direction and a width direction.

The front sheet includes a strip-like ridge portion extending in the longitudinal direction and a non-woven fabric having a concave-convex structure in which the concave strip portions are alternately arranged in the width direction, and the concave strip portion is joined to the adjacent lower side sheet.

The above non-woven fabric is made of at least a high elongation fiber.

The lower side sheet contains an aggregate of fibers of a thermoplastic resin.

The ridge portion has a hollow structure between the nonwoven fabric and the lower sheet.

The non-woven fabric has a top region, a bottom region, and a side portion between the same In the region, the top of the ridge portion is formed by the top portion, and the bottom portion of the concave portion is formed by the bottom portion.

The fiber density in the side region is lower than either the fiber density of the top region and the fiber density of the bottom region.

1‧‧‧nonwoven

1a‧‧‧Fiber sheets

1b‧‧‧Fiber

2‧‧‧Front sheet

3‧‧‧Back sheet

4‧‧‧Acceptor

4a‧‧‧lateral edge

6‧‧‧Bottom sheet

6a‧‧‧non-joining

6'‧‧‧ Winding

7‧‧‧The Peripheral Department

8‧‧‧ leak-proof cuffs

8a‧‧‧Free end

8b‧‧‧Fixed area

8c‧‧‧Flexible components

8d‧‧‧Flexible area

10‧‧‧Sanitary pads

10A‧‧‧ front area

10B‧‧‧ Rear area

10C‧‧‧Central Area

11‧‧‧Fiber

12‧‧‧Fuse Department

13‧‧‧Rocks

13a‧‧‧Top area

13b‧‧‧ bottom area

13c‧‧‧Side area

14‧‧‧ recessed section

14s‧‧‧ joints

16‧‧‧Little Trails Department

17‧‧‧The Great Trails Department

18‧‧‧Change point

40‧‧‧Absorbable core

41‧‧‧Package

42‧‧‧Absorbable sheet

43‧‧‧High-density department

44‧‧‧ Low Density Department

100‧‧‧ manufacturing equipment

200‧‧‧Net Formation Department

201‧‧‧ net forming device

300‧‧‧Hot Air Treatment Department

301‧‧ hood

302‧‧‧ conveyor belt

400‧‧‧Extension

401‧‧‧ bump roll

402‧‧‧ bump roll

403‧‧‧ Large diameter convex

404‧‧‧ Large diameter convex

500‧‧‧Bottom sheet joint

501‧‧‧Smooth roller

a, b‧‧‧ front and back

A‧‧‧Liquid

B‧‧‧Liquid

AT‧‧‧Area

BT‧‧‧ area

CT‧‧‧Central Area

H‧‧‧ Height

L3‧‧‧ length

L5‧‧ ‧ total length

T‧‧‧injection

T‧‧‧ interval

W‧‧‧ interval

X‧‧‧ length direction

Y‧‧‧Width direction

Z‧‧‧ Thickness direction

Fig. 1 is a perspective view showing a sanitary pad as an embodiment of the present invention.

Figure 2 is an enlarged cross-sectional view taken along line II-II of Figure 1.

Figure 3 is a cross-sectional view of the absorbent body for the sanitary pad shown in Figure 1.

Fig. 4 is a partially broken perspective view showing an enlarged main part of the skin facing side of the sanitary pad shown in Fig. 1;

Fig. 5 is a schematic enlarged view of a main part of Fig. 4.

Fig. 6 is a view for explaining a state in which the constituent fibers constituting the nonwoven fabric shown in Fig. 4 are fixed to each other by a heat fusion portion.

Figure 7 is a plan view of the skin facing surface of the sanitary pad shown in Figure 1.

Fig. 8 is a schematic view showing a manufacturing apparatus preferably used for manufacturing the nonwoven fabric shown in Fig. 4.

Figure 9 is a cross-sectional view taken along line IX-IX of Figure 8.

(a), (b), and (c) of FIG. 10 are explanatory views for explaining a case where a plurality of small-diameter portions and large-diameter portions are formed in one of the constituent fibers between the adjacent fusion portions.

Fig. 11 is a perspective view showing an incontinence pad as another embodiment of the present invention.

Fig. 12 (a) is an enlarged cross-sectional view taken along line II-II of Fig. 11, and Fig. 12 (b) is a view showing a back surface (a surface on the non-skin contact surface side) of the absorbent body of the incontinence pad shown in Fig. 11.

Fig. 13 is a partially broken perspective view showing the main part of the incontinence pad shown in Fig. 11 in an enlarged manner.

Fig. 14 is a partially enlarged plan view showing a skin contact surface of an incontinence pad in an arrangement example of a joint portion between a concave portion of a front sheet and a lower sheet.

Fig. 15 is a partially enlarged plan view showing an absorbent body of another example of the arrangement of the compression portion forming the high-density portion.

Fig. 16 is an explanatory view showing the effects of the present invention.

Hereinafter, the present invention will be described based on preferred embodiments thereof with reference to the drawings.

Fig. 1 is a perspective view showing a sanitary pad 10 (hereinafter also referred to simply as "sanitary pad 10") as an embodiment of the present invention. Figure 2 is an enlarged cross-sectional view taken along line II-II of Figure 1.

As shown in FIGS. 1 and 2, the sanitary pad 10 includes a liquid-permeable front sheet 2 for forming a skin contact surface, a liquid-impermeable back sheet 3, and two sheets 2 interposed therebetween. 3 absorbers 4. Liquid impermeability includes liquid impermeability. The sanitary 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 front and rear directions of the wearer when the sanitary pad 10 is worn, and the width direction Y is a direction orthogonal to the longitudinal direction X when the sanitary pad 10 is viewed from above. The sanitary pad 10 has a plan view elliptical shape in which the central portion in the longitudinal direction is tapered.

The portions of the front sheet 2 and the back sheet 3 which extend from the periphery of the absorbent body 4 are joined to each other at the peripheral edge portion 7 of the panty liner 10. An adhesive portion (not shown) that is fixed to the undergarment such as a pair of shorts is provided on the surface (non-skin contact surface) of the back sheet 3 of the panty liner 10. The skin contact surface is the side of the absorbent article or the constituent member that faces the wearer's skin side when worn, and the non-skin contact surface is the opposite of the wearer's skin side when worn in the absorbent article or its constituent members. The side (usually the side of the panties).

The absorbent body 4 of the sanitary pad 10 includes the absorbent sheet 42, and more specifically, the absorbent sheet 42 includes a laminated body in which two or more layers are laminated. The laminate of two or more layers may be a sheet in which an absorbent sheet is folded as shown in, for example, FIG. 3, and the layers are laminated to form a laminate, or a single sheet of the absorbent sheet may be laminated to a plurality of sheets. And carry on the layer. Further, an additional absorbent sheet may be disposed between the layers of the two or more layers or on one surface to form a single absorbent sheet. Part of the thick-walled absorber.

In the sanitary pad 10, as the absorbent sheet 42, an absorbent sheet containing a fibrous material and a water-absorptive polymer is used. As the absorbent sheet, it is preferable to use an adhesive force generated by a water-absorbent polymer in a wet state or an adhesive such as an adhesive or an adhesive which is additionally added to form an interfiber or a constituent. The fiber and the water-absorbing polymer are combined to form a sheet. Further, as the absorbent sheet, an absorbent sheet produced by the method described in JP-A-H08-246395 can be used; after the pulverized pulp and the water-absorbing polymer supplied with the gas flow are deposited, Applying a hot-melt adhesive to a dry sheet, a paper or a non-woven fabric which is solidified by an adhesive (for example, a vinyl acetate-based adhesive, PVA (polyvinyl alcohol), etc.), and then spread An absorbent sheet obtained by superabsorbent polymer; an absorbent sheet obtained by blending a superabsorbent polymer in a step of producing a spunbond or meltblown nonwoven fabric. These absorbent sheets may be used in the form of an absorbent body having a single layer structure without laminating two or more layers. Also, the layers may not be connected between the layers.

The thickness of the absorber 4 is preferably 0.1 mm or more, more preferably 0.5 mm or more, further preferably 5 mm or less, more preferably 2 mm or less, further preferably 0.1 mm or more and 5 mm or less, and further preferably 0.5 or less. Mm or more and 2 mm or less. The thickness of the absorber 4 was measured by the following method.

The thickness T was measured using a PIACOCK type precision measuring device (Model R1-C) which has two parallel pressing surfaces (fixed pressing surface and movable pressing surface). The measurement was carried out under the conditions that the probe movable pressing surface had a diameter of 5 mm and a pressure of 100 kPa or less. The size of the test piece for measurement is set to be equal to or larger than the size of the following flat plate. A 20 mm × 20 mm flat plate (mass 5.4 g) was placed on the test piece, and the probe movable pressing surface was operated at a speed of 2 mm/s, and the plate was abutted to read the value immediately after stabilization. The pressure between the pressure surfaces (pressure applied to the test piece) was 1.3 kPa or less.

As a material for forming the back sheet 3, it can be used for absorption without any particular limitation. As the various materials of the back sheet of the article, for example, a liquid impervious or water-repellent resin film, a laminated film of a resin film and a non-woven fabric, or the like can be used.

As shown in FIG. 2 and FIG. 4, the topsheet 2 of the sanitary pad 10 of the present embodiment includes stripe-like ridges 13 and strips 14 extending in one direction and alternately arranged in the width direction. Non-woven fabric 1 of uneven structure. Further, as shown in FIGS. 2 and 4, the front sheet 2 is joined to the adjacent lower side sheet 6 at the joint portion 14s by the concave strip portion 14, and the ridge portion 13 is between the nonwoven fabric 1 and the lower side sheet 6. Has a hollow structure. The nonwoven fabric 1 constituting the front sheet 2 includes fibers 11 having large diameter portions 17 and small diameter portions 16 and 16 having mutually different fiber diameters as shown in FIG. 6 below.

The nonwoven fabric 1 constituting the front sheet 2 will be described in more detail.

Fig. 4 is a perspective view showing the nonwoven fabric 1 (hereinafter also referred to as "nonwoven fabric 1") used as the top sheet 2 in the sanitary pad 10 of the present embodiment. Fig. 5 is a schematic view showing a cross section of the nonwoven fabric 1 shown in Fig. 4 in the thickness direction. Fig. 6 is an enlarged schematic view showing the constituent fibers 11 of the nonwoven fabric 1 shown in Fig. 4. As shown in Fig. 4, the nonwoven fabric 1 includes a plurality of nonwoven fabrics (see Fig. 6) in which the fusion portions 12 (see Fig. 6) formed by thermally fusing the intersections of the constituent fibers 11 are provided. Further, in the nonwoven fabric 1, as shown in FIG. 4, the "one direction" in which the ridge portions 13 and the concave strip portions 14 extend is the same as the longitudinal direction X of the sanitary pad 10, and is also expressed as one direction (X). direction).

More specifically, as shown in FIG. 5, the nonwoven fabric 1 has a plurality of ridge portions 13 whose cross-sectional shapes of the front and back sides a and b are convex toward the upper side in the thickness direction (Z direction); The strip portion 14 is located between adjacent rib portions 13, 13. The cross-sectional shape of both the front and back sides a and b of the concave strip portion 14 is concave toward the upper side in the thickness direction (Z direction) of the nonwoven fabric. In other words, the cross-sectional shapes of the front and back surfaces a and b of the concave strip portion 14 are convex toward the lower side in the thickness direction (Z direction) of the nonwoven fabric. Further, the plurality of ridge portions 13 are continuously extended in one direction (X direction) of the nonwoven fabric 1, and the plurality of the concave strip portions 14 also have a groove shape continuously extending in the direction X of the nonwoven fabric 1. The ridge portion 13 and the groove portion 14 are parallel to each other and alternately arranged in a direction (Y direction) orthogonal to the one direction (X direction).

As shown in Fig. 5, when the non-woven fabric 1 is cross-sectionally observed in the thickness direction Z, the nonwoven fabric 1 includes a top portion 13a, a bottom portion 13b, and a side portion 13c between them. The top region 13a, the bottom region 13b, and the side region 13c continuously extend in one direction (X direction) of the nonwoven fabric 1. When the non-woven fabric 1 is cross-sectionally observed in the thickness direction Z, the top region 13a, the bottom region 13b, and the side region 13c divide the thickness of the non-woven fabric 1 into three equal parts, and the portion above the thickness direction Z as the top region. 13a, the center portion is referred to as a side portion 13c, and the lower portion is referred to as a bottom portion 13b to be distinguished. The top of the ridge portion 13 is formed by the top portion 13a. The bottom of the groove portion 14 is formed by the bottom portion 13b.

As described below, the nonwoven fabric 1 is manufactured by performing uneven processing on the fiber sheet 1a by the pair of uneven rolls 401 and 402. The longitudinal direction X of the nonwoven fabric 1 is the same as the machine direction (MD, flow direction) when the nonwoven fabric 1 is produced by the uneven processing of the fiber sheet 1a (see FIG. 8), and is orthogonal to the X direction of the nonwoven fabric 1 The direction Y is the same direction as the orthogonal direction (CD, roller direction) orthogonal to the machine direction (MD, flow direction).

As shown in Fig. 5, when the nonwoven fabric 1 is observed along the thickness direction Z, the fiber density of the side portion 13c is lower than the fiber density of the top portion 13a and the fiber density of the bottom portion 13b. The fiber density refers to the number of fibers per unit area of the cross section of the nonwoven fabric 1. Therefore, the number of fibers in the side portion 13c is smaller than that in the top portion 13a and the bottom portion 13b (the distance between the fibers is large), and becomes a loose region. Therefore, the air permeability of the side portion 13c becomes higher than that of the top portion 13a and the bottom portion 13b. As a result, the sanitary pad of the present embodiment using the nonwoven fabric 1 as the front sheet 2 is in the worn state, the air flows along the groove portion 14, and in the ridge portion 13, the air is along the side portion 13c. The direction perpendicular to the ridge portion 13 flows. In this way, the sanitary pad of the present embodiment has a structure in which air flows in any of the longitudinal direction X and the width direction Y on the opposite side of the skin. Therefore, the skin on the opposite side of the skin is excellent in air permeability and is not easily worn. It’s stuffy. And by Since the ridge portion 13 including the nonwoven fabric 1 and the concave strip portion 14 are alternately formed, the uneven structure of the front sheet 2 easily follows the action of the wearer in the wearing state of the sanitary pad 10, and the touch of the skin is good.

In particular, as shown in FIG. 1 , each side edge of the sanitary pad 10 is formed into a combined curve shape, and each of the side edges is convexly curved toward the outer side in the width direction in the longitudinal direction front region 10A and the rear region 10B, and In the longitudinal direction central portion 10C, the side edges are convexly curved toward the inner side in the width direction, whereby the width in the longitudinal direction central portion 10C is minimized, whereby it is easy to efficiently discharge toward the outer side in the width direction Y. steam. Thereby, it is also less likely to cause sultry heat in the wearing state of the sanitary pad 10.

Fiber density region 13c of the side portions (D _13c) with respect to the fiber density (D _13a) top region 13a of, or fiber density (D _13b) of the region 13b of the bottom of the ratio _{(D 13c / D 13a, D} 13c / D 13a) It is preferably 0.15 or more and 0.9 or less, and more preferably 0.2 or more and 0.8 or less. Specifically, regarding the value of the fiber density of the nonwoven fabric 1, the fiber density (D _13a ) of the top region 13a is preferably 90 pieces/mm ² or more and 200 pieces/mm ² or less, and more preferably 100 pieces/mm ² or more. And 180 pieces/mm ² or less. Further, the fiber density (D _13b ) of the bottom portion 13b is preferably 80 pieces/mm ² or more and 200 pieces/mm ² or less, and more preferably 90 pieces/mm ² or more and 180 pieces/mm ² or less. Further, the fiber density (D _13a ) of the side portion 13c is preferably 30 pieces/mm ² or more and 80 pieces/mm ² or less, and more preferably 40 pieces/mm ² or more and 70 pieces/mm ² or less. The method for measuring the fiber density is as follows.

[Method for Measuring Fiber Density of Top Region 13a, Bottom Region 13b, and Side Region 13c]

The nonwoven fabric was cut in the thickness direction Z using a Feather razor (product number FAS-10, manufactured by Feather Safety Razor Co., Ltd.). Regarding the fiber density of the top region 13a, a scanning electron microscope is used to magnify the top region 13a which is a portion above the thickness of the cut surface of the nonwoven fabric divided into three equal portions in the Z direction (adjusted to a fiber profile of 30) ~60 or so magnifications, 150 to 500 times), the number of sections of the fibers cut by the cut surface was counted for each fixed area (about 0.5 mm ² ). Next, the number of sections of the fiber per 1 mm ² is converted into the fiber density of the top region 13a. The measurement system was carried out on three sites, and the average value was taken to determine the fiber density of the sample. Similarly, the fiber density of the bottom region 13b is determined by measuring a portion below the thickness of the cut surface of the nonwoven fabric divided into three equal portions in the Z direction. Similarly, the fiber density of the side portion region 13c is determined by measuring the thickness of the cut surface of the non-woven fabric in the center of the three-dimensional portion in the Z direction. Further, as a scanning electron microscope, JCM-5100 (trade name) manufactured by JEOL Ltd. was used.

As described above, the fiber density (D _13c ) of the side portion 13c of the ridge portion 13 is preferably 30 pieces/mm ² or more and 80 pieces/mm ² or less, and more preferably 40 pieces/mm ² or more and 70 pieces. /mm ² or less. That is, although it is preferable that the fiber density of the side portion 13c is lower than the fiber density of the top portion 13a and the bottom portion 13b, the fiber density of the side portion 13c is preferably not zero. In other words, the fiber density of the side portion 13c is preferably more than 0/mm ² . The fact that the fiber density of the side portion 13c is zero means that a through hole is formed in the side portion 13c. Therefore, in the present embodiment, it is preferable that the through hole is not formed in the side portion 13c. When the fiber density of the side portion 13c is zero, that is, when the through hole is formed in the side portion 13c, it is easy to generate liquid return through the through hole, or the ridge portion 13 is easily crushed. When the number of through holes is reduced in order to prevent the occurrence of such a through hole, the flowability of the air in the direction orthogonal to the ridge portion 13 is lowered. As described above, when the through hole is formed in the side portion 13c, various problems occur. On the other hand, if the fiber density of the side portion 13c is lowered as in the present embodiment, the liquid return or the ridge portion 13 can be prevented from being crushed. Further, the advantage of the fluidity of the air in the direction orthogonal to the ridge portion 13 is ensured.

The uneven structure of the nonwoven fabric 1 including the ridge portion 13 and the concave strip portion 14 is preferably formed at least in a central region in the width direction Y of the sanitary pad 1. Thereby, since the uneven structure can be provided in the part which is most likely to contact the skin of the wearer, the above-described effect of preventing sultry heat or the effect of following the action of the wearer can be surely exhibited. Especially, the way to make these effects more obvious In the surface, it is preferable that the front sheet 2 has a concavo-convex structure over the entire area of the inner peripheral portion 7 (see FIG. 1).

In the sanitary pad 10 of the present embodiment, it is preferable that at least the longitudinal direction central portion 10C, each side edge 4a of the absorber 4 is linear, and the direction in which the side edge 4a extends is set to The uneven structure, that is, the direction in which the ridge portions 13 and the groove portions 14 extend is substantially parallel. Thereby, the front sheet 2 is easily bent at the side edge 4a of the absorber 4, and the wearing discomfort of the sanitary pad 10 is reduced. The so-called "substantially parallel" includes the case of being completely parallel and the case where the angle is within 3 degrees.

The constituent fibers 11 of the nonwoven fabric 1 contain high elongation fibers. Here, the high-elongation fiber included in the constituent fiber 11 refers not only to a fiber having a high elongation at the stage of the raw material fiber but also to a fiber having a high elongation at the stage of the nonwoven fabric 1 to be produced. The "high-strength fiber" is a low-speed melting, as described in paragraph [0033] of JP-A-2010-168715, in addition to the elastic fiber (elastic body). After the conjugate fiber is obtained by spinning, the heat-expandable fiber obtained by heating to change the crystal state of the resin and extending length without heating treatment and/or crimping treatment is obtained; or, a resin made of a resin such as propylene or polyethylene, which is produced by setting a spinning speed to a relatively low condition; or a polyethylene-polypropylene copolymer having a low degree of crystallization, or a polyethylene blended with polypropylene. Fiber made from silk, etc. Among these fibers, the high elongation fiber is preferably a core-sheath type composite fiber having heat fusion properties. The core-sheath type composite fiber may be a concentric core sheath type, and may be an eccentric core sheath type, and may be a side-by-side type or a profiled type, and particularly preferably a concentric core sheath type. The fineness of the high elongation fiber is preferably 1.0 dtex or more and 10.0 dtex or less in the raw material stage, from the viewpoint of producing a nonwoven fabric having a good softness and a good touch, etc., regardless of the form of the fiber. Good is 2.0dtex or more and 8.0dtex or less.

The constituent fibers 11 of the nonwoven fabric 1 may be composed of other fibers in addition to the high elongation fibers, but are preferably composed only of high elongation fibers. As other fibers, for example The core-sheath type heat-fusible composite fiber which has the non-thermal extensibility which consists of the two-components of the melting point, and the fiber which does not have heat-fus Or acetate fiber, etc.). In the case where the nonwoven fabric 1 contains a high elongation fiber and also contains other fibers, the ratio of the high elongation fiber in the nonwoven fabric 1 is preferably 50% by mass or more and 100% by mass or less, and more preferably 80% by mass. The above is 100% by mass or less.

The heat-expandable composite fiber of the high-elongation fiber is a composite fiber which has been subjected to the unstretching treatment or the weak elongation treatment in the raw material stage, and has, for example, a first resin component constituting the core portion and a second resin component constituting the sheath portion. The resin component has a first resin component having a higher melting point than the second resin component. The first resin component is a component that exhibits thermal elongation of the fiber, and the second resin component is a component that exhibits heat fusion properties. The melting point of the first resin component and the second resin component is a finely cut fiber sample (sample weight: 2 mg) at a temperature increase rate of 10 ° C/min using a differential scanning calorimeter (DSC6200 manufactured by Seiko Instruments Co., Ltd.). Thermal analysis was carried out, and the melting peak temperature of each resin was measured and defined by the melting peak temperature. When the melting point of the second resin component cannot be clearly determined by this method, the resin is defined as "a resin having no melting point". In this case, the temperature at which the molecules of the second resin component start to flow, and the temperature at which the second resin component is fused to the extent that the strength of the fusion point of the fiber can be measured is used as the softening point, and the melting point is used instead.

The second resin component constituting the sheath portion contains a polyethylene resin as described above. 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 portion is preferably a polyethylene resin alone, but may be blended with other resins. Examples of the other resin to be blended include a polypropylene resin, an ethylene-vinyl acetate copolymer (EVA), and an ethylene-vinyl alcohol copolymer (EVOH). However, the second resin component constituting the sheath portion is preferably a polyethylene resin in an amount of 50% by mass or more, particularly 70% by mass or more and 100% by mass or less based on the resin component of the sheath portion. Further, the polyethylene resin preferably has a crystallite size of 10 nm or more and 20 nm or less, more preferably 11.5 nm or more and 18 nm or less.

As the first resin component constituting the core portion, a resin component of a polyethylene resin having a melting point higher than that of the sheath portion can be used without particular limitation. Examples of the resin component constituting the core portion include polyolefin resins (excluding polyethylene resins) such as polypropylene (PP), polyethylene terephthalate (PET), and polybutylene terephthalate (PBT). ) such as a polyester resin. Further, a polyamine polymer or a resin component may be used as a copolymer of two or more kinds. It may be used by blending a plurality of resins. In this case, the melting point of the core is the melting point of the resin having the highest melting point. The difference between the melting point of the first resin component constituting the core portion and the melting point of the second resin component constituting the sheath portion (the former - the latter) is preferably 20 ° C or higher, and more preferably Below 150 °C.

The preferred orientation index of the first resin component in the thermally extensible composite fiber as the high elongation fiber is naturally different depending on the resin to be used. For example, when the first resin component is a polypropylene resin, the orientation index is preferably 60% or less, more preferably 40% or less, further preferably 25% or less. When the first resin component is a polyester, the orientation index is preferably 25% or less, more preferably 20% or less, still more preferably 10% or less. On the other hand, the second resin component preferably has an alignment index of 5% or more, more preferably 15% or more, still more preferably 30% or more. The alignment index is an index of the degree of alignment of the polymer chains constituting the resin of the fiber. In addition, the index of elasticity of the first resin component and the second resin component is the above value, and the heat-expandable composite fiber is elongated by heating.

The alignment index of the first resin component and the second resin component is determined by the method described in paragraphs [0027] to [0029] of JP-A-2010-168715. Moreover, the method of achieving the orientation index as described above in each of the resin components in the thermally extensible conjugate fiber is described in paragraphs [0033] to [0036] of JP-A-2010-168715.

Further, the elongation of the high elongation fiber is preferably 100% or more, more preferably 200% or more, and still more preferably 250% or more in the raw material stage. Moreover, the elongation of the high elongation fiber is The raw material stage is preferably 800% or less, particularly preferably 500% or less, and more preferably 400% or less. Specifically, 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 still more preferably 250% or more and 400% or less in the raw material stage. By using a high elongation fiber having an elongation in the range, the fiber is smoothly stretched in the stretching device, and the change point from the small diameter portion to the large diameter portion is adjacent to the fusion portion, and the skin touches The feeling is getting good.

The elongation of the high elongation fiber is determined according to JIS L-1015 under the conditions of measuring the ambient temperature and humidity of 20 ± 2 ° C, 65 ± 2% RH, the clamp interval of the tensile tester of 20 mm, and the tensile speed of 20 mm / min. Benchmark. In addition, when the elongation is measured by taking the fiber from the non-woven fabric produced by itself, when the jig interval cannot be 20 mm, that is, when the length of the measured fiber is less than 20 mm, the jig interval is set to 10 mm or 5 mm. The measurement was carried out.

The ratio of the first resin component to the second resin component in the thermally extensible conjugate fiber of the high elongation fiber (mass ratio, the former: the latter) is preferably 10:90 to 90:10 at the raw material stage, and particularly preferably 20 : 80~80:20, especially better 50:50~70:30. The fiber length of the heat-expandable composite fiber corresponds to the manufacturing method of the nonwoven fabric, and an appropriate length is used. In the case where the nonwoven fabric is produced by the carding method as described below, the fiber length is preferably about 30 to 70 mm.

The fiber diameter of the heat-expandable composite fiber as the high-elongation fiber is appropriately selected depending on the specific use of the nonwoven fabric in the raw material stage. When a non-woven fabric is used as a constituent member of an absorbent article such as a front sheet of an absorbent article, it is preferably used in an amount of 10 μm or more and 35 μm or less, particularly preferably 15 μm or more and 30 μm or less. The above fiber diameter was measured by the following method.

[Determination of fiber diameter of fibers]

The fiber diameter of the fiber was measured by using a microscope VH-8000 (manufactured by KEYENCE) to enlarge the cross section of the fiber to 200 to 800 times. Diameter (μm). The cross section of the fiber was obtained by cutting a fiber using a Feather razor (product number FAS-10, manufactured by Feather Safety Razor Co., Ltd.). Regarding the extracted one fiber, the fiber diameter when the shape was approximated to a circle was measured at five locations, and the average value of the five points of the respective measured values was defined as the diameter of the fiber.

In the raw material stage, as the high elongation fiber, that is, the heat-expandable composite fiber, in addition to the above-mentioned heat-expandable composite fiber, Japanese Patent No. 4131852, Japanese Patent Laid-Open Publication No. 2005-350836, and Japanese Patent Laid-Open No. 2007 can be used. A fiber described in, for example, Japanese Laid-Open Patent Publication No. 2007-204901, Japanese Patent Laid-Open No. Hei. No. 2007-204901, and Japanese Patent Laid-Open No. Hei. No. 2007-204902.

The nonwoven fabric 1 is preferably such that, as shown in Fig. 6, when one of the constituent fibers 11 of the nonwoven fabric 1 is formed, the constituent fibers 11 have a fiber diameter sandwiched between the adjacent fusion portions 12 and 12 The smaller diameter portion 17 of the smaller two small diameter portions 16 and 16 having a larger fiber diameter. Specifically, as shown in FIG. 6, when one of the constituent fibers 11 of the nonwoven fabric 1 is made to constitute the fiber 11, the fusion portion 12 formed by thermally fusing the intersection with the other constituent fibers 11 has a small fiber diameter. The small diameter portion 16 is formed by extending substantially the same fiber diameter. In addition, when focusing on the one constituent fiber 11, the large-diameter portion 17 having a small fiber diameter and a large diameter portion 16 between the small-diameter portions 16 and 16 extending from the adjacent fusion portions 12 and 12 It is formed by extending substantially the same fiber diameter. As will be described in detail, when one constituent fiber 11 is focused on, the nonwoven fabric 1 has a small diameter from the fusion portion 12 of the adjacent fusion portions 12 and 12 toward the other fusion portion 12, and has a side of the fusion portion 12 in this order. The constituent fibers 16 of the portion 16 and the one large diameter portion 17 and the small diameter portion 16 on the other fusion portion 12 side.

As described above, the low-diameter portion 16 having a low rigidity so as to be adjacent to the fusion portion 12 which is a portion where the rigidity of the nonwoven fabric 1 is increased is improved, and the softness of the nonwoven fabric 1 is improved, and the skin feel is improved. In addition, the more the large-diameter portion 17 is provided, in other words, the small-diameter portion 16 having the lower rigidity of the constituent fibers 11 is formed, the softness of the nonwoven fabric 1 is further improved, and the skin feel is further improved.

As shown in FIG. 6, when one of the constituent fibers 11 of the nonwoven fabric 1 is focused on the constituent fibers 11, the nonwoven fabric 1 has a plurality of adjacent fusion portions 12 and 12 (two in the nonwoven fabric 1). The large diameter portion 17 constitutes the fiber 11. As will be described in detail, when one constituent fiber 11 is focused on, the nonwoven fabric 1 has a small diameter from the fusion portion 12 of the adjacent fusion portions 12 and 12 toward the other fusion portion 12, and has a side of the fusion portion 12 in this order. The constituent fibers 16 of the portion 16, 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 fusion portion 12 side. When the nonwoven fabric 1 is focused on one of the constituent fibers 11, it is preferable to provide one or more of the adjacent fusion portions 12 and 12 from the viewpoint of improving the touch of the skin and preventing the strength of the nonwoven fabric from being lowered. In addition, it is preferable to provide one or more and three or less from the viewpoint of improving the touch of the skin and the strength of the non-woven fabric.

The small-diameter portion 16 of the fiber diameter (L ₁₆₎ with respect to the large diameter portion 17 of the fiber diameter (L ₁₇₎ of the ratio (L ₁₆ / L ₁₇₎ is preferably 0.5 or more and 0.8 or less, and further 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, from the viewpoint of improving the touch of the skin. Μm or more and 16 μm or less. The fiber diameter (diameter L ₁₇ ) of the large diameter portion 17 is preferably 10 μm or more 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 feeling of the skin.

The fiber diameters (diameters L ₁₆ and L ₁₇ ) of the small diameter portion 16 and the large diameter portion 17 were measured in the same manner as the measurement of the fiber diameter of the above fibers.

In the case of the non-woven fabric 1, when the fiber 11 is formed of one of the constituent fibers 11 of the nonwoven fabric 1, the change point 18 from the small-diameter portion 16 adjacent to the fusion portion 12 to the large-diameter portion 17 is shown. Preferably, it is disposed within a range of one third of the interval T between the fused portion 12 and the adjacent fused portions 12 and 12. Here, the change point 18 of the nonwoven fabric 1 does not include the continuous change from the small-diameter portion 16 which is extended by the smaller fiber diameter to the large-diameter portion 17 which has a fiber diameter larger than the fiber diameter of the small-diameter portion 16. Change in parts or continuously throughout multiple stages The part, but the part of the fiber whose diameter is extremely variable. In the case where the one constituent fiber 11 is a thermally extensible conjugate fiber, the change point 18 of the nonwoven fabric 1 does not include a relationship between the first resin component constituting the core portion and the second resin component constituting the sheath portion. A state in which the fiber diameter is changed by peeling, but a portion where the fiber diameter always changes due to elongation.

Further, the change point 18 is disposed in the range of 1/3 of the interval T between the fusion portion 12 and the adjacent fusion portions 12 and 12, and the constituent fibers 11 of the nonwoven fabric 1 are randomly extracted and used as shown in FIG. The JCM-5100 (trade name) manufactured by JEOL Ltd. of the scanning electron microscope is used to observe the constituent fibers 11 in a manner (100 times to 300 times) between the adjacent fusion portions 12 and 12 constituting the fibers 11. Zoom in and observe. Then, the distance T between the centers of the adjacent fusion portions 12 and 12 is divided into three equal parts, and is divided into a region AT on the side of the fusion portion 12, a region BT on the side of the other fusion portion 12, and a central region CT. Further, it means that the change point 18 is disposed in the above-described area AT or the above-described area BT. In addition, the non-woven fabric 1 in which the change point 18 is disposed in the range of 1/3 of the interval T between the fusion portion 12 and the adjacent fusion portions 12 and 12 means that when the constituent fibers 11 of the 20 nonwoven fabrics 1 are randomly extracted, The constituent fibers 11 in which the change point 18 is disposed in the region AT or the region BT have at least one nonwoven fabric in the 20 constituent fibers 11 . Specifically, from the viewpoint of improving the touch of the skin, it is preferably one or more, more preferably five or more, and still more preferably 10 or more.

The nonwoven fabric 1 is formed such that the number of fibers having the change point 18 in the constituent fibers 11 constituting the side portion 13c is larger than the number of fibers having the change point 18 in the constituent fibers 11 constituting the top portion 13a, and the bottom portion 13b is formed. The number of fibers having the change point 18 in the constituent fibers 11 is large. The number of fibers (N _13c ) having the change point 18 in the constituent fibers 11 constituting the side portion 13c is relative to the number of fibers (N _13a ) having the change point 18 in the constituent fibers 11 constituting the top portion _13a , or constitutes The ratio (N _13c /N _13a , N _13c /N _13a ) of the number of fibers (N _13b ) having the change point 18 in the constituent fibers 11 of the bottom portion 13b is preferably 2 or more and 20 or less, and further preferably 5 Above and below 20. Specifically, with respect to the specific value of the number of fibers having the change point 18 of the nonwoven fabric 1, the number of fibers (N _13c ) having the change point 18 in the constituent fibers 11 constituting the side portion 13c is preferably 5 or more. Further, it is 20 or less, and more preferably 10 or more and 20 or less. Further, the number of fibers (N _13a ) having the change point 18 in the constituent fibers 11 constituting the top region 13a is preferably one or more and 15 or less, and more preferably five or more and 15 or less. Further, the number of fibers (N _13b ) having the change point 18 in the constituent fibers 11 constituting the bottom portion 13b is preferably one or more and 15 or less, and more preferably five or more and 15 or less. The method for determining the number of fibers having the change point 18 is as follows.

[Method of Measuring the Number of Fibers Having Change Point 18 among the constituent fibers of the top region 13a, the bottom region 13b, or the side region 13c]

The number of fibers having the change point 18 in the constituent fibers 11 constituting the top region 13a is magnified by scanning electron microscopy near the apex of the top region 13a which is the portion above the thickness of the nonwoven fabric divided into three equal portions in the Z direction. Observed (adjusted to a fiber profile to measure a magnification of about 30 to 60, 50 to 500 times), 20 randomly selected constituent fibers 11 constituting the top portion 13a, and 20 fibers having a change point 18 in the constituent fibers 11 Count. This is taken as the number of fibers having the change point 18 among the constituent fibers constituting the top region 13a. The measurement system was carried out on three sites, and the average value thereof was taken as the number of fibers having the change point 18 among the constituent fibers constituting the top region 13a of the sample. Similarly, the number of fibers having the change point 18 in the constituent fibers 11 constituting the bottom portion 13b is measured in the vicinity of the bottom portion of the bottom portion 13b which is the portion below the thickness of the nonwoven fabric divided into three equal portions in the Z direction. And find it. In the same manner, the number of fibers having the change point 18 in the constituent fibers 11 constituting the side portion 13c is determined by measuring the position at the center when the thickness of the nonwoven fabric is divided into three equal portions in the Z direction. Further, as a scanning electron microscope, JCM-5100 (trade name) manufactured by JEOL Ltd. was used.

Regarding the thickness of the nonwoven fabric 1, the thickness of the entire non-woven fabric 1 is set to the sheet thickness T _S , and the thickness of the non-woven fabric 1 which is bent by the unevenness is set as the layer thickness T _L . The sheet thickness T _S may be appropriately adjusted depending on the application, and is preferably 0.5 mm or more and 7 mm or less, more preferably 1.0 mm or more and 5 mm or less when used as a front sheet or a secondary layer of an absorbent article. By setting it as this range, the body fluid absorption speed at the time of use is faster, and it can suppress the liquid-repelling body of a self-absorber, and can implement moderate cushioning property. Further, even if a load is applied, the shape of the ridge portion 13 can be maintained.

The layer thickness T _L may be different between the respective portions in the nonwoven fabric 1 and may be appropriately adjusted depending on the use. The layer thickness T _{L1 of the} top region 13a is preferably 0.1 mm or more and 3.0 mm or less, more preferably 0.2 mm or more and 2.0 mm or less. The layer thickness T _{L2 of the} bottom portion 13b is preferably 0.1 mm or more and 3.0 mm or less, more preferably 0.2 mm or more and 2.0 mm or less. The layer thickness T _{L3 of the} side portion 13c is preferably 0.1 mm or more and 3.0 mm or less, more preferably 0.2 mm or more and 2.0 mm or less. The relationship between the thicknesses T _L1 , T _L2 , and T _L3 of each layer is set to this range, and the body fluid absorption speed at the time of use is fast, and the liquid return of the self-absorber can be suppressed, thereby achieving moderate cushioning properties.

The sheet thickness T _S and the layer thickness T _L were measured by the following methods.

The measurement method of the sheet thickness T _S was carried out using a thickness measuring device while applying a load of 0.05 kPa to the nonwoven fabric 1. The thickness gauge was a laser displacement meter manufactured by OMRON. The thickness measurement was carried out at 10 points, and the average value of these was calculated to be the thickness.

The layer thickness T _L was measured by amplifying the cross section of the sheet by about 20 times with a digital microscope VHX-900 manufactured by KEYENCE, thereby measuring the thickness of each layer.

When the nonwoven fabric 1 is viewed from above, the distance between the tops of the ridge portions 13 adjacent to each other in the Y direction is preferably 1 mm or more and 15 mm or less, more preferably 1.5 mm or more and 10 mm or less. The height H (see FIG. 4) of the ridge portion 13 is preferably 0.5 mm or more and 5 mm or less, more preferably 1 mm or more and 3 mm or less. The height H is a cross section of the thickness direction Z of the nonwoven fabric 1 observed by a microscope, and is measured under no load.

Further, the basis weight of the nonwoven fabric 1 as a whole and the average value was good regardless of 15g / m ² or more and 50g / m ² or less, more preferably 20g / m ² or more and 40g / m ² or less.

On the surface of the constituent fibers 11 of the nonwoven fabric 1, a small amount of a fiber treating agent such as a fiber coloring agent, an antistatic property agent, a lubricant, and a hydrophilic agent may be attached to the raw material stage.

As a method of attaching the fiber treating agent to the surface constituting the fiber 11, various known methods can be employed without particular limitation. For example, application by spraying, application by a slit coater, application by transfer, immersion in a fiber treatment agent, etc. are mentioned. These treatments can be carried out on the fibers before the webization, or after the fibers are networked by various methods. However, it is necessary to perform the treatment before the hot air blowing treatment described below. The fiber to which the fiber treatment agent is adhered on the surface is dried, for example, by a hot air blow dryer at a temperature sufficiently lower than the melting point of the polyethylene resin (for example, 120 ° C or lower).

As shown in Fig. 2 and Fig. 4, the top sheet 2 in the sanitary pad 10 of the present embodiment is attached to the underside of the non-woven fabric 1 constituting the front sheet 2 by heat fusion. The sheet 6 is joined. In the present embodiment, the lower side sheet 6 is a second sheet 6 which is disposed between the front sheet 2 and the absorbent body 4 and which comprises an aggregate of fibers of a thermoplastic resin. As the aggregate of the fibers of the thermoplastic resin, a nonwoven fabric can be generally used.

The concave portion 14 of the front sheet 2 is continuously joined to the second sheet 6 in the longitudinal direction of the sanitary pad 10, and the engaging portion 14s is disposed between the sealing portions 7 at both end portions in the longitudinal direction, and is interposed therebetween The length direction X of the sanitary pad 10 is intermittently formed. By intermittently joining the front sheet 2 and the second sheet 6, the air permeability between the two sheets can be ensured, and the sultry heat of the sanitary pad 10 in the worn state can be further reduced. However, the front sheet 2 and the second sheet 6 may be continuously joined over the entire length direction X.

The joining of the front sheet 2 and the second sheet 6 is not limited to the above-described heat fusion, and other joining methods such as bonding using an adhesive such as a hot-melt adhesive may be employed. The length of the second sheet 6 in the longitudinal direction X and the width direction Y can be made shorter than that of the front sheet 2. Alternatively, the length of the second sheet 6 in the longitudinal direction X and the width direction Y may be the same as that of the front sheet 2.

By joining the front sheet 2 having the uneven structure to the flat second sheet 6, the uneven structure of the front sheet 2 is such that even if a load is applied thereto, the hollow structure of the ridge portion 13 is less likely to be flattened. For example, it is preferable that the ridge portion maintains the hollow structure in a state where the sanitary pad 10 is applied with a load of 4 g/cm ² from the side of the front sheet 2, and it is preferable to apply a load of 20 g/cm ² . In this state, the ridge portion can maintain the hollow structure. The term "maintainable hollow structure" means that after the load is applied, there is also a space inside the ridge portion 13, and the shape of the space is allowed to be deformed before the load is applied. Whether or not there is a space inside the ridge portion 13 is formed by cutting a joint of the front sheet and the second sheet 6 in the thickness direction Z, and observing the cross section by a microscope. The load of 4 g/cm ² is intended to mount the sanitary pad 10 to the shorts, and the pressure applied to the panty liner 10 when the pants are worn. The load of 20 g/cm ² is assumed to be the pressure applied to the panty liner 10 when the wearer sits on the chair in the wearing state of the panty liner 10.

When the constituent fibers of the nonwoven fabric 1 are high elongation fibers, the ridge portions 13 are also less likely to be crushed with respect to the load. Specifically, in the manufacturing method of the nonwoven fabric 1 described below, when the nonwoven fabric 1 is produced by extending the fiber sheet 1a (see FIG. 8), if the fiber is cut by stretching, even if the ridge portion 13 is formed, The strength of compression is also reduced. On the other hand, by using the high elongation fiber, the fiber is less likely to be cut during the elongation of the fiber sheet 1a, and the low fiber density side portion 13c can be smoothly formed, and the ridge portion can be effectively prevented. The strength of 13 is reduced.

As the aggregate of the fibers constituting the thermoplastic resin of the second sheet 6, a nonwoven fabric obtained by various production methods can be used. For example, a hot air non-woven fabric which forms a thermal fusion point of fibers with each other by a hot air method using a fiber obtained by a carding method or an air spinning method, and a fiber web obtained by a carding method by a hot roll method may be used to form heat of fibers. Various non-woven fabrics such as heat roller non-woven fabric, hot embossed non-woven fabric, spunlace non-woven fabric, needle-punched non-woven fabric, resin bonded non-woven fabric, and the like.

In particular, as the nonwoven fabric, a fluffy nonwoven fabric having an apparent density of 0.005 g/cm ³ or more and 0.5 g/cm ³ or less, particularly 0.01 g/cm ³ or more and 0.1 g/cm ³ or less is preferably used. By using a fluffy nonwoven fabric as the second sheet 6, the second sheet 6 functions as a spacer between the barrier absorbent 4 and the front sheet 2, and promotes the circulation of air between the absorbent body 4 and the front sheet 2. Thereby, the sultry heat of the sanitary pad 10 in the wearing state is further prevented. As the fluffy nonwoven fabric, for example, a hot air non-woven fabric, an air-laid non-woven fabric, a resin-bonded non-woven fabric, or the like can be preferably used.

Further, in at least the longitudinal direction central portion 10C of the sanitary pad 10, the width of the absorbent body 4 is narrower than either the width of the front sheet 2 and the width of the second sheet 6, whereby the front sheet is easily held. The width of the material 2 and the side of the left and right sides of the second sheet 6 are in a dry state in a portion extending from the side edge 4a (see FIG. 2) of the absorber 4 to the outside in the width direction. As a result, even after the absorbent body 4 absorbs the liquid, the water vapor permeability of the left and right side portions of the sanitary pad 10 is not easily broken. Therefore, the sultry heat in the wearing state is further reduced.

In the sanitary pad 10 of the present embodiment, the nonwoven fabric 1 used as the topsheet 2 is preferably manufactured by a manufacturing method of a non-woven fabric having the following steps: a fusing step in which a high elongation is included by using a fusing portion The fiber fibers of the fiber web are thermally fused to form a fiber sheet at an intersection thereof, and an extending step of extending the fiber sheet in one direction. Regarding one embodiment of the manufacturing method of the nonwoven fabric 1 used as the front sheet 2, a preferred manufacturing method of the nonwoven fabric 1 will be described as an example, and will be described with reference to FIG. A preferred manufacturing apparatus 100 for the manufacturing method of the nonwoven fabric 1 is schematically illustrated in FIG. The manufacturing apparatus 100 is preferably used by a manufacturer of hot air non-woven fabrics. The manufacturing apparatus 100 is provided with the mesh forming part 200, the hot air processing part 300, the extension part 400, and the lower side sheet joining part 500 from the upstream side of the manufacturing process toward the downstream side.

As shown in FIG. 8, the mesh forming unit 200 is provided with a mesh forming device 201. As the net forming device 201, a carding machine is used. As the carding machine, the same as the usual user in the technical field of the absorbent article can be used without particular limitation. Other net making devices, such as air spinning devices, may be used in place of the carding machine.

As shown in FIG. 8, the hot air processing unit 300 is provided with a cover 301. In the cover 301, hot air can be blown by hot air. Further, the hot air treatment unit 300 is provided with a ring including a gas permeable mesh. Conveyor belt 302. The conveyor belt 302 is wrapped around the cover 301. The conveyor belt 302 is formed of a resin such as polyethylene terephthalate or a metal.

The temperature of the hot air blown in the cover 301 and the heat treatment time are preferably adjusted so as to be thermally fused at the intersection of the high elongation fibers contained in the constituent fibers 11 of the fiber web 1b. More specifically, the temperature of the hot air is preferably adjusted to a temperature of 0 ° C to 30 ° C higher than the melting point of the resin having the lowest melting point in the constituent fibers 11 of the fiber web 1 b. The heat treatment time is preferably adjusted to 1 second to 5 seconds in accordance with the temperature of the hot air. Further, from the viewpoint of promoting further entanglement between the constituent fibers 11, the wind speed of the hot air is preferably about 0.3 m/sec to 1.5 m/sec. Further, the conveying speed is preferably about 5 m/min to 100 m/min.

As shown in FIGS. 8 and 9, the extending portion 400 includes a pair of uneven rollers 401 and 402 that can mesh with each other. The pair of uneven rollers 401 and 402 are formed to be heated, and are formed by alternately arranging the large-diameter convex portions 403 and 404 and the small-diameter concave portions (not shown) in the roller axis direction. The embossing rolls 401 and 402 may be heated or not heated, and the heating temperature in the case of heating the embossing rolls 401 and 402 is easy to extend the high elongation fiber contained in the constituent fibers 11 of the fiber sheet 1a described below. Preferably, the glass transition point of the resin having the highest glass transition point in the high elongation fiber is equal to or lower than the melting point of the resin having the lowest melting point in the high elongation fiber. More preferably, it is higher than the temperature at which the glass transition point of the fiber is 10 ° C or higher and 10 ° C lower than the melting point, and further preferably higher than the temperature of the glass transition point of the fiber by 20 ° C or higher and lower than the melting point by 20 ° C. . For example, when a PE (sheath) having a glass transition point of 67 ° C, a melting point of 258 ° C, a glass transition point of -20 ° C, and a melting point of 135 ° C is used as the fiber in the core/sheath structure of the fiber, The temperature is preferably from 67 ° C to 135 ° C, more preferably from 77 ° C to 125 ° C, and further preferably from 87 ° C to 115 ° C.

Further, as shown in FIG. 9, in the manufacturing apparatus 100, the interval (pitch) between the large-diameter convex portions 403 and 403 adjacent to each other in the roll axis direction of the uneven roller 401 is opposite to the roll axis direction of the uneven roller 402. The interval (pitch) between the adjacent large-diameter convex portions 404 and 404 is the same interval (between With respect to the interval w, the high elongation fiber contained in the constituent fiber 11 of the fiber sheet 1a is smoothly stretched in the stretching device, and the small diameter portion to the large diameter portion described above The point of change is adjacent to the fusion portion, and the skin feel is preferably from 1 mm to 10 mm, more preferably from 1.5 mm to 8 mm. From the same point of view, as shown in FIG. 10, the amount of pressing t of the pair of embossing rolls 401, 402 (the apex of the large-diameter convex portion 403 adjacent to the roll axis direction and the apex of the large-diameter convex portion 404) It 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. Further, from the same viewpoint, the mechanical stretching 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 joining portion 500 includes the uneven roller 402 and a smooth roller 501 having a smooth surface, and the uneven fabric 1 and the lower sheet are formed between the large-diameter convex portion 404 of the uneven roller 402 and the peripheral surface of the smoothing roller 501. 6 is joined by heating and pressurization.

A method of manufacturing the nonwoven fabric 1 using the manufacturing apparatus 100 having the above configuration will be described.

First, as shown in Fig. 8, in the net forming portion 200, a short fiber-like constituent fiber 11 having a heat-expandable composite fiber as a high elongation fiber is used as a raw material, and a net forming device 201 as a carding machine is used. The web 1b is formed (web forming step). The web 1b manufactured by the net forming device 201 is in a state in which the constituent fibers 11 are sparsely intertwined with each other, and the shape retaining property as a sheet is not obtained.

Then, as shown in FIG. 8, the fiber sheet 1a is formed by thermally fusing the intersections of the constituent fibers 11 of the fiber web 1b containing the high elongation fibers by the fusing portion 12 (fusion step). Specifically, the fiber web 1b is conveyed on the conveyor belt 302, and the hot air processing unit 300 blows hot air by hot air while passing through the inside of the cover 301. When the hot air is blown by the hot air, the constituent fibers 11 of the fiber web 10 are further entangled with each other, and at the same time, the intersection of the fibers entangled with each other is thermally fused (refer to FIG. 10(a)), thereby producing a sheet-like shape retaining property. Fiber sheet 1a.

Then, as shown in Fig. 8, the fused web 1a is extended in one direction (extension step). Specifically, the fused fiber web 1a having the shape retaining property as a sheet is conveyed between the pair of embossing rolls 401 and 402, and the web 1a is made as shown in Figs. 10(a) to 10(c). One of the constituent fibers 11 extending between the adjacent fusion portions 12 and 12 forms a large diameter portion 17 having a large fiber diameter sandwiched between the two small diameter portions 16 and 16 having a small fiber diameter, and The change point 18 from the small diameter portion 16 to the large diameter portion 17 is formed within a range of one third of the interval T between the fusion portion 12 and the adjacent fusion portions 12 and 12. As described in detail, the fiber sheet 1a which is thermally fused by the fusion portion 12 at the intersection of the constituent fibers 11 as shown in Fig. 10(a) is conveyed between the pair of embossing rolls 401 and 402, so that the web 1a is along It extends in the orthogonal direction (CD, roller direction) orthogonal to the machine direction (MD, flow direction). When the fiber sheets 1a are extended in the orthogonal direction (CD, roll direction), the regions of the fused portions 12, 12 adjacent to each other of the fixed constituent fibers 11 shown in Fig. 10(a) are orthogonal to each other. The direction (CD, roll direction) is actively stretched. In particular, as shown in FIG. 10(b), in the vicinity of the respective fused portions 12 of the fixed constituent fibers 11, first, local shrinkage is likely to occur, and one of the adjacent fused portions 12 and 12 is formed as a fiber 11, Two small diameter portions 16 and 16 are formed at both ends, and a portion sandwiched between the two small diameter portions 16 and 16 serves as a large diameter portion 17, and a large diameter portion 17 sandwiched between the two small diameter portions 16 and 16 is formed. As described above, in the vicinity of each of the fused portions 12, local contraction is likely to occur first. Therefore, the change point 18 from the small-diameter portion 16 to the large-diameter portion 17 is formed at the interval from the fused portion 12 to the adjacent fused portions 12 and 12 Within 1/3 of T.

Further, as for the one of the adjacent ones of the welded portions 12 and 12, the fibers 11 are formed, as shown in Fig. 10(c), in a state where the stretchable space (elongation margin) remains, and further along the orthogonal The direction (CD, roll axis direction) extends, and the large diameter portion 17 between the adjacent fusion portions 12 and 12 extends, and a plurality of small diameter portions 16 are formed in the large diameter portion 17.

In the stretching step, the large-diameter convex portion 403 of the uneven roller 401 and the large-diameter convex portion 404 of the uneven roller 402 are formed in the fiber sheet 1a while the small-diameter portion 16 and the large-diameter portion 17 are formed of the high-elongation fibers. The part is longer than the other parts. In this case, due to the fiber sheet Since the constituent fibers of 1a are high-elongation fibers, they are not cut even if they are stretched, and the stretching is smoothly performed. Since the portion of the fiber sheet 1a between the large-diameter convex portion 403 of the uneven roller 401 and the large-diameter convex portion 404 of the uneven roller 402 is the side portion 13c of the convex strip portion 13 in the target nonwoven fabric 1, it is borrowed. By the above stretching, the fibers are not cut in the side portion 13c, and the distance between the fibers is increased before the elongation. As a result, the fiber density of the side portion 13c is lower than that of other portions, and the gas permeability is improved. Further, since the fibers constituting the side portion 13c are not cut, the strength of the ridge portion 13 is maintained at a high level. As a result, even if a load is applied to the ridge portion 13, the ridge portion 13 is less likely to be crushed.

The nonwoven fabric 1 manufactured as described above is directly conveyed to the sheet merging portion of the lower sheet joining portion 500 in a state of being deformed into a concave-convex shape by the uneven roller 402. The strip-shaped non-woven fabric 6 for the second sheet which is wound up from the roll-like wound material 6' is supplied to the sheet merging portion, and the non-woven fabric 1 having the uneven shape is placed in a state of being overlapped with the strip-shaped non-woven fabric 6, and is introduced into the unevenness. Between the roller 402 and the smoothing roller 501. Between the uneven roller 402 and the smoothing roller 501, the concave portion portion and the strip-shaped non-woven fabric 6 in the uneven-shaped non-woven fabric 1 are heated between the large-diameter convex portion 404 of the uneven roller 402 and the circumferential surface of the smoothing roller 501. And joined by pressurization. In this manner, a strip-shaped composite sheet 8 in which the front sheet 2 including the nonwoven fabric 1 is joined to the lower sheet 6 is obtained. The strip-shaped composite sheet 8 is introduced into the manufacturing line of the sanitary pad 10 after being wound up, or introduced into the manufacturing line of the sanitary pad 10 without being taken up.

Fig. 11 is a perspective view showing an incontinence pad 10 (hereinafter also referred to simply as "incontinence pad 10") as another embodiment of the present invention. Fig. 12 (a) is an enlarged cross-sectional view taken along line II-II of Fig. 11, and Fig. 12 (b) is a view showing a back surface (a surface on the non-skin contact surface side) of the absorbent body of the incontinence pad 10 shown in Fig. 11 . In addition, in the embodiment shown in FIG. 11 to FIG. 16 described below, the embodiment shown in FIGS. 1 to 10 will be described in detail with respect to the aspects which are not particularly described. In addition, in FIGS. 11 to 16, the same members as those shown in FIGS. 1 to 10 are denoted by the same reference numerals.

As shown in FIG. 1 and FIG. 2( a ), the incontinence pad 10 has a liquid permeability forming a skin abutting surface. The front sheet 2, the liquid impervious back sheet 3, and the absorber 4 interposed between the two sheets 2 and 3. 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 is the same as the front and rear directions of the wearer when the incontinence pad 10 is worn, and the width direction Y is the direction orthogonal to the longitudinal direction X when the incontinence pad 10 is viewed. The incontinence pad 10 has an elliptical shape in plan view.

The front sheet 2 and the back sheet 3 are extended from the periphery of the absorber 4. An adhesive portion (not shown) that is fixed to the undergarment such as a pair of shorts is provided on the surface (non-skin contact surface) of the back sheet 3 of the incontinence pad 10.

The absorbent body 4 of the incontinence pad 10 includes an absorbent core 40 and a core sheet 41 covering the absorbent core 40. The absorbent core 40 may include a fiber deposit of liquid-absorbent fibers such as pulp, or a mixed fiber stack of the liquid-absorbent fibers and the water-absorbent polymer. Examples of the liquid-absorbent fiber constituting the absorbent core 40 include cellulose-based hydrophilic fibers such as pulp fibers, ray fibers, cotton fibers, and cellulose acetate. In addition to the cellulose-based hydrophilic fiber, a polyolefin-based fiber such as polyethylene or polypropylene, a condensed fiber such as polyester or polyamide may be contained. Examples of the water-absorbing polymer include sodium polyacrylate, (acrylic acid-vinyl alcohol) copolymer, sodium polyacrylate crosslinked body, (starch-acrylic acid) graft copolymer, and (isobutylene-maleic anhydride) copolymer. And its saponification, polyaspartic acid and the like. The fiber and the water-absorptive polymer may be used alone or in combination of two or more. As the clad core material 41, a water permeable fibrous sheet such as toilet paper or non-woven fabric is preferably used. Further, the packaged core material 41 may be coated with the entire absorbent core 40 by a single sheet, or the entire core of the absorbent core 40 may be coated with two or more packages of the core material, for example, may be coated with different sheets. The skin contact surface side of the absorbent core 40 and the non-skin contact surface side.

The thickness of the absorber 4 is preferably 1 mm or more, more preferably 2 mm or more, further preferably 15 mm or less, more preferably 10 mm or less, further preferably 1 mm or more and 15 mm or less, and further preferably 2 mm or more and 10 mm. the following. The thickness of the absorbent body 4 is determined by the method described above.

A leak-proof flange 8 extending in the longitudinal direction is provided at a position on both sides of the width direction Y of the skin contact surface side of the incontinence pad 10, respectively. The leak-proof cuff 8 has a free end 8a and a fixed area 8b extending in the longitudinal direction. The fixing area 8b is located on the front sheet 2. Further, the leakage preventing flange 8 is fixed to the front sheet 2 at the fixing region 8b. Further, the fixing region 8b of the leakage preventing flange 8 is extended to the outside in the width direction Y, and the extending portion is joined to the extending portion in the width direction of the back sheet 3 to form the side flaps 7. In the leak-preventing crest 8, an elastic member 8c extending in the longitudinal direction X is attached to the free end 8a at or near the free end 8a. The elastic members 8c are arranged in a plurality of 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 specific length in the width direction Y, and extends at least in the longitudinal direction X at a position of the opposing portion of the wearer's excretion portion. Further, the planar elastic region 8d can be expanded and contracted in the longitudinal direction X. By contracting the elastic member 8c, the position between the free end 8a of the leak-proof cuff 8 and the fixed end 8b rises in a substantially L-shape toward the body side of the wearer, and the planar elastic region 8d abuts against the wearer's Skin, preventing side leakage of liquids.

As shown in Fig. 12 (a) and Fig. 13, the front sheet 2 of the incontinence pad 10 of the present embodiment includes stripe-like ridge portions 13 and recessed portions 14 extending in the longitudinal direction and alternately arranged in the width direction. Non-woven fabric 1 made of concave and convex structure. Further, as shown in Fig. 12 (a) and Fig. 13, the front sheet 2 is joined to the adjacent second sheet 6 (lower sheet) at the joint portion 14s by the groove portion 14, and the ridge portion 13 is engaged with The second sheet 6 has a hollow structure between them. As shown in Fig. 6 as described above, the nonwoven fabric 1 constituting the front sheet 2 includes fibers 11 having large diameter portions 17 and small diameter portions 16 and 16 having mutually different fiber diameters.

The nonwoven fabric 1 constituting the front sheet 2 will be described in more detail.

Fig. 13 is a perspective view showing the nonwoven fabric 1 used as the front sheet 2 in the incontinence pad 10 of the present embodiment. As shown in Fig. 13, the nonwoven fabric 1 includes a plurality of nonwoven fabrics (see Fig. 6) in which the fusion portions 12 (see Fig. 6) formed by thermally fusing the intersections of the constituent fibers 11 are provided. Further, in the nonwoven fabric 1 constituting the front sheet 2, as shown in Fig. 13, the ridge portion 13 and the concave portion 14 are extended. The "one direction" is the same as the longitudinal direction X of the incontinence pad 10, and the "one direction" in which the ridge portion 13 and the concave portion 14 are extended in the nonwoven fabric 1 is expressed as the X direction.

More specifically, as shown in FIG. 5 described above, the nonwoven fabric 1 has a plurality of ridge portions 13 whose cross-sectional shapes of the front and back sides a and b are convex toward the upper side in the thickness direction (Z direction). And a concave portion 14 located between adjacent rib portions 13, 13. The cross-sectional shape of both the front and back sides a and b of the concave strip portion 14 is concave toward the upper side in the thickness direction (Z direction) of the nonwoven fabric. In other words, the cross-sectional shapes of the front and back surfaces a and b of the concave strip portion 14 are convex toward the lower side in the thickness direction (Z direction) of the nonwoven fabric. Further, the plurality of ridge portions 13 are continuously extended in one direction (X direction) of the nonwoven fabric 1, and the plurality of the concave strip portions 14 also have a groove shape continuously extending in the direction X of the nonwoven fabric 1. The ridge portion 13 and the groove portion 14 are parallel to each other, and are alternately arranged in a direction (Y direction) orthogonal to the one direction (X direction).

It is preferable that the uneven structure of the nonwoven fabric 1 including the ridge portion 13 and the concave strip portion 14 is formed at least in a central region in the width direction Y of the incontinence pad 10. Thereby, since the uneven structure can be provided in the part which is most easily contacted with the wearer's skin, the effect of the above-mentioned anti-stickiness is more reliably exerted.

The constituent fibers 11 of the nonwoven fabric 1 contain high elongation fibers. Further, the constituent fibers 11 of the nonwoven fabric 1 may be composed of other fibers in addition to the high elongation fibers, and are preferably composed only of high elongation fibers. Examples of high elongation fibers and other fibers are as described above.

As shown in Fig. 3 as described above, the top of the non-woven fabric 1 rib portion 13 is formed by the top portion 13a, and the bottom portion of the concave strip portion 14 is formed by the bottom portion 13b. Therefore, the ridge portions 13 of the nonwoven fabric 1 constituting the front sheet 2 have side portions 13c on both sides of the sandwich top portion 13a, respectively, and a fiber density is formed between the top portion 13a and the joint portion 14s. 13a low side region 13c. Since the fiber density of the side portion 13c is lower than the top portion 13a, or the top portion 13a and the bottom portion 13b, the liquid entering the ridge portions 13 is in contact with each other. The body is transferred to the hollow space under the ridge portion 13 or the second sheet 6 via the side portion 13c, and the transferred liquid is not easily returned to the top region 13a which forms the surface contacting the skin. Thereby, it is possible to more reliably prevent the unpleasant feeling caused by the excretion liquid contacting the wearer's skin.

The nonwoven fabric 1 is formed such that the number of fibers having a change point among the constituent fibers constituting the side portion 13c is larger than the number of fibers having the change point 18 among the constituent fibers constituting the top portion 13a, and the constituent fibers constituting the bottom portion 13b. The number of fibers having a change point 18 is large. The number of fibers (N _13c ) having a change point in the constituent fibers constituting the side portion 13c is relative to the number of fibers (N _13a ) having the change point 18 among the constituent fibers constituting the top portion _13a , or constitutes the bottom portion 13b. The ratio (N _13c /N _13a , N _13c /N _13b ) of the number of fibers (N _13b ) having the change point 18 in the constituent fibers is preferably 2 or more and 20 or less, and 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 (N _13a ) having the change point 18 among the constituent fibers constituting the top region 13a is preferably one or more and 15 or more. Below the root, it is more preferably 5 or more and 15 or less. Moreover, the number of fibers (N _13b ) having the change point 18 among the constituent fibers constituting the bottom region 13b is preferably one or more and 15 or less, and more preferably five or more and 15 or less. Moreover, the number of fibers (N _13c ) having the change point 18 among the constituent fibers constituting the side portion 13c is preferably 5 or more and 20 or less, and more preferably 10 or more and 20 or less. The method for determining the number of fibers having the change point 18 is as follows.

As shown in Figs. 12 and 13, the front sheet 2 in the incontinence pad 10 of the present embodiment is thermally bonded to each other by the heat-fusion of the concave portion 14 of the nonwoven fabric 1 constituting the front sheet 2. The second sheet 6 of the side sheets is joined. In the present embodiment, the lower side sheet is a second sheet 6 which is disposed between the front sheet 2 and the absorbent body 4 and which comprises an aggregate of fibers of a thermoplastic resin. As the aggregate of the fibers of the thermoplastic resin, a nonwoven fabric can be generally used.

The non-woven fabric 1 of the concave portion 14 of the front sheet 2 and the fiber containing the thermoplastic resin is continuously joined to the second sheet 6 along the longitudinal direction of the incontinence pad 10 as shown in Fig. 13, and the joint portion 14s is spread over the front sheet. The length of the portion where the material 2 overlaps the second sheet 6 is the entire length direction. Such as As shown in Fig. 14, by continuously joining the concave portion 14 of the front sheet 2 and the second sheet 6, the liquid-oriented ridges on the second sheet 6 under the ridge portion 13 can be prevented from being transferred. The portion 13 is transferred downward, and the liquid is efficiently diffused in the longitudinal direction X. Therefore, it is possible to more reliably suppress the unpleasant feeling caused by the excretion liquid contacting the skin of the wearer, and to more effectively utilize the absorption capacity in a wide range in the longitudinal direction of the absorbent body 4. However, the front sheet 2 and the second sheet 6 may be formed intermittently in the longitudinal direction X.

In the incontinence pad 10, the front sheet 2 and the second sheet 6, and more specifically, the nonwoven fabric 1 constituting the front sheet 2 and the fibers constituting the second sheet 6 respectively comprise fibers of a thermoplastic resin. In the joint portion 14s, the concave portion 14 of the front sheet 2 and the second sheet 6 are integrally heat-sealed by heat sealing and heat-sealed.

In the joint portion 14s to be thermally fused, it is preferable that the constituent fibers of the nonwoven fabric 1 constituting the front sheet 2 and the fibers constituting the second sheet 6 do not maintain the form of fibers. In order not to maintain the form of the fiber, it is preferred that the heating temperature of the heat seal be equal to or higher than the melting point of the constituent fibers of one of the nonwoven fabric and the fiber assembly. In the case of a composite fiber including two components having different melting temperatures, the melting point of the constituent fibers is the melting point of the component having the lowest melting point.

By having this configuration of the joint portion 14s, it is possible to prevent the liquid transferred to the second sheet 6 under the ridge portion 13 from being displaced downward toward the side ridge portion 13, and to efficiently diffuse the liquid in the longitudinal direction X. Therefore, it is possible to more reliably suppress the unpleasant feeling caused by the excretion liquid contacting the skin of the wearer, and to more effectively utilize the absorption capacity in a wide range in the longitudinal direction of the absorbent body 4.

Further, it is preferable that the joint portion 14s of the concave strip portion 14 and the second sheet member 6 (lower sheet member) is liquid-impermeable. The term "liquid impermeability" as used herein means that the liquid does not pass through the front sheet 2 or the second sheet 6.

The method of forming the liquid-impermeable joint portion 14s is such that the front sheet 2 and the second sheet 6 are thermally fused in such a manner that the constituent fibers of the two sheets do not maintain the fibers. Law and so on.

Instead of joining the lower sheet such as the front sheet 2 and the second sheet 6 by heat fusion, another joining method such as bonding by using an adhesive such as a hot-melt adhesive or the second sheet 6 may be used ( The lower side sheet) is joined.

The joining of the front sheet 2 and the second sheet 6 is not limited to the above-described heat fusion, and other joining methods such as bonding using an adhesive such as a hot-melt adhesive may be employed. The second sheet 6 can make the length X and the width direction Y shorter than the front sheet 2. Alternatively, the length of the second sheet 6 in the longitudinal direction X and the width direction Y may be the same as that of the front sheet 2.

As the nonwoven fabric constituting the second sheet 6, it is preferable to form a long-fiber nonwoven fabric in which the fibers are aligned in the longitudinal direction X. The term "long-fiber nonwoven fabric" refers to a nonwoven fabric containing long fibers, and examples thereof include a spunbond nonwoven fabric and a spunlace nonwoven fabric.

Further, as the non-woven fabric constituting the second sheet 6, a non-woven fabric other than the long-fiber nonwoven fabric may be used. For example, various non-woven fabrics such as a heat roller nonwoven fabric, a heat embossed nonwoven fabric, and a spunlace nonwoven fabric which are arranged in the longitudinal direction X of the fibers may be used. . Regarding these non-woven fabrics, whether or not the constituent fibers are aligned in the longitudinal direction X can be determined by the following method.

The orientation of the fibers was measured by a microwave molecular alignment meter MOA-6004 (manufactured by Oji Scientific Instruments Co., Ltd.) in the form of a MOR (modulus of rupture) value. The orientation of the fibers was set to an average of 5 points of the number of samples.

By aligning the constituent fibers of the second sheet 6 in the longitudinal direction X, the liquid transferred to the hollow space under the ridge portion 13 or the liquid of the second sheet 6 is not transferred to the side ridge portion under the ridge portion 13. 13 down, and easy to spread in the length direction, more difficult to produce side leakage or sticky feeling.

In the incontinence pad 10 of the present embodiment, the fiber density of the aggregate of fibers constituting the second sheet 6 is higher than the fiber density of the nonwoven fabric 1 constituting the topsheet 2.

When the nonwoven fabric 1 used in the present embodiment has a plurality of regions having different fiber densities in the thickness direction, the fiber density (D _13a ) of the nonwoven fabric constituting the front sheet 2 is the fiber density at the top of the ridge portion 13. . Moreover, the fiber density (D ₆ ) of the aggregate of the fibers constituting the second sheet 6 is the fiber density of the non-joining portion 6a which is not joined to the nonwoven fabric constituting the front sheet 2.

The fiber density (D _13a ) at the top of the ridge portion 13 was measured in the same manner as the fiber density of the top portion 13a. The fiber density (D ₆ ) of the aggregate of the fibers constituting the second sheet 6 is a collection of fibers constituting the second sheet 6 using a Feather razor (product number FAS-10, manufactured by Feather Safety Razor Co., Ltd.). The thickness direction Z is cut, and the cut surface of the non-joining portion in the aggregate of the fibers is enlarged and observed, and the fiber density of the above [top region 13a, bottom region 13b, and side region 13c) is used. The measurement method is cut in the same manner. The fiber density of the non-joining portion 6a of the second sheet 6 is preferably measured by observing the cut surface of the portion of the second sheet 6 that faces the top portion (the top portion 13a) of the ridge portion 13.

The second sheet material fiber density (D ₆₎ relative to the top (top region 13a) of the protruding strip portion of the fiber density (D _13a) of the ratio (D _13a / D _{6) 6} is preferably of 1.1 or more, and further preferably 2 or more.

In the absorber 4 of the incontinence pad 10 of the present embodiment, as shown in FIGS. 12(a) and 12(b), a high-density portion is formed in a plurality of portions in the width direction Y by embossing. 43. The density of the high-density portion 43 is higher than the portions 44 and 44 (hereinafter also referred to as the low-density portion 44) on both sides in the width direction, and is formed to extend in the longitudinal direction X, respectively. In other words, in the absorber 4, the high-density portion 43 and the low-density portion 44 are alternately arranged in parallel.

Further, as shown in FIG. 12(a), each of the high-density portions 43 is formed at a position overlapping the top of the ridge portion 13. As described in detail, the high-density portion 43 extends in the longitudinal direction X, and a plurality of rows are formed in the width direction Y, and each of the high-density portions 43 and the top of the ridge portion 13 continuously overlap in the longitudinal direction X.

The high-density portion 43 in the present embodiment is formed by pressurizing between an embossing roll having a convex portion and a groove portion extending in the circumferential direction or the axial direction and an anvil roll having a smooth surface on the circumferential surface. In the high-density portion 43, the thickness of the absorber 4 is thinner than other portions. Further, the surface of the absorbent body 4 on the non-skin contact surface side is the surface on the embossing roll side, and the high-density portion 43 is absorbed. The surface of the body 4 on the non-skin contact surface side has a concave portion corresponding to the ridge portion of the circumferential surface of the embossing roll.

The high-density portion 43 can be formed only by pressurization, or can be formed by heating while pressurizing.

The number of the high-density portions 43 which are formed in the width direction Y of the absorber 4 and overlap the top of the ridges 13 of the front sheet 2 are plural, preferably three or more, more preferably five or more. It is preferably 8 or more.

The length of the high-density portion 43 in the width direction Y is preferably 20 mm or more, and more preferably 50 mm or more. Further, the length of the high-density portion 43 continuous in the longitudinal direction X is preferably 30% or more, more preferably 50% or more, and still more preferably 100%, with respect to the entire length of the absorbent body 4 in the same direction.

Further, the high-density portion 43 may be formed continuously in the longitudinal direction X of the absorber 4 in a shape in which the high-density portion 43 having a long shape in the longitudinal direction X is formed in the longitudinal direction X as shown in FIG. The high-density portion 43 having a long shape is intermittently formed along the longitudinal direction X of the absorber 4. In this case, the length L3 of the longitudinal direction X of the high-density portion 43 is preferably 0.5 mm or more, more preferably 1 mm or more, and the length L3 of the high-density portion 43 is the length L3 and the length direction X. The total length L5 of the lengths of the adjacent high-density portions 43 and 43 is preferably 5% or more, and more preferably 30% or more.

Low density portion 44. (D ₄₎ with respect to the ratio of the density (D ₃₎ of the high density portion 43 of (D ₃ / D ₄₎ is preferably 1.5 or more, and further preferably 3 or more. The density of the high-density portion 43 and the low-density portion 44 was measured by using a Feather razor (product number FAS-10, manufactured by Feather Safety Razor Co., Ltd.), and a sample of a thin portion throughout the thickness direction was cut out from each portion of the absorber 4. The mass of each sample was measured, and the mass measured was divided by the volume calculated by multiplying the thickness of the sample by the plan view area. The thickness of the sample was measured without load before being cut out from the absorber.

According to the incontinence pad 10 of the present embodiment, the front sheet 2 includes the nonwoven fabric 1 having the uneven structure of the ridge portion 13 and the concave portion 14 extending in the longitudinal direction X, and constitutes the second When the fiber density of the aggregate of the fibers of the sheet 6 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 quickly enters the ridge portion 13 as shown in FIG. Between each other, the two side portions of the top of the ridge portion 13, particularly the side portion 13c, are transferred to the second sheet 6 under the ridge portion 13.

Further, regarding the liquid B transferred onto or in the second sheet 6 under the ridge portion 13, due to the density difference between the nonwoven fabric 12 and the second sheet 6, and the concave portion 14 is joined to the second sheet 6 Since the structure in which the inside of the ridge portion 13 is hollow is easily maintained during wearing, the liquid B is less likely to return to the portion of the ridge portion 13 that contacts the skin. Thereby, it is possible to more reliably suppress the unpleasant feeling caused by the excretion liquid contacting the wearer's skin.

From the viewpoint of exerting this effect, it is preferred that the second sheet 6 (lower sheet) has a higher hydrophilicity than the front sheet 2. The hydrophilicity of the second sheet 6 and the hydrophilicity of the front sheet 2 are determined by measuring the contact angle of water with respect to the fibers constituting the second sheet 6 and the contact angle of water with the constituent fibers of the nonwoven fabric 1 constituting the front sheet 2. The smaller the contact angle, the less hydrophilic.

Further, according to the incontinence pad 10 of the present embodiment, the portion of the absorber 4 that overlaps the top (top region 13a) of the ridge portion 13 of the nonwoven fabric 1 has the high-density portion 43, and thus is transferred to the ridge portion 13 The liquid B on the second sheet 6 flows in the longitudinal direction X on the low-density portion 44 and is absorbed by the high-density portion 43.

Thereby, it is possible to surely suppress the unpleasant feeling caused by the excretion liquid contacting the skin of the wearer, and to effectively utilize the absorption capacity in a wide range in the longitudinal direction of the absorbent body 4.

The interlayer between the second sheet 6 and the absorber 4, the absorbent sheet constituting the absorbent body 4, and the absorbent body 4 and the back sheet 3 are preferably joined by an adhesive. In the case where the members are joined by an adhesive, it may be a full coating by a slit coater or the like, preferably a pattern coating. Preferred examples of the pattern applied by the pattern coating include a spiral pattern, a dot pattern, a stripe pattern (striped pattern), a lattice pattern, a checkerboard pattern, and the like.

Hereinabove, the present invention has been described based on preferred embodiments thereof, but the present invention The absorbent article is not limited to the above-described embodiment, and can be appropriately changed. For example, the above embodiment is an example in which the present invention is applied to a sanitary pad or an incontinence pad, and the present invention may be applied to other absorbent articles such as menstrual sanitary napkins or disposable diapers.

Further, in the embodiment shown in FIG. 11, the length of the second sheet 6 including the nonwoven fabric in one or both of the longitudinal direction X and the width direction Y of the incontinence pad 10 may be the same as that of the front sheet 2. It can also be shorter. Moreover, the incontinence pad 10 may also be a person who does not have a leak-proof cuff.

In the above embodiment, the present invention further discloses the following absorbent article.

<1> An absorbent article comprising a front sheet which forms a liquid permeability of a skin contact surface, a back sheet, and an absorber interposed between the sheets, and having a longitudinal direction and a width direction The front sheet includes a strip-like ridge portion extending in the longitudinal direction and a non-woven fabric having a concave-convex structure in which the concave strip portions are alternately arranged in the width direction, and the concave strip portion is joined to the adjacent lower side sheet. The nonwoven fabric is made of at least a high elongation fiber, and the lower sheet comprises an aggregate of fibers of a thermoplastic resin, and the ridge portion has a hollow structure between the nonwoven fabric and the lower sheet, and the nonwoven fabric has a top portion. a region, a bottom region, and a side region between the same, wherein a top portion of the ridge portion is formed by the top portion, and a bottom portion of the concave portion is formed by the bottom portion, and a fiber density of the side portion is higher than the top portion Any of the fiber density of the region and the fiber density of the bottom region described above are low.

(2) The absorbent article according to the above aspect, wherein the absorbent article has at least the uneven structure in a central region in the width direction of the absorbent article.

The absorbent article according to the above aspect, wherein the convex portion is maintained in a state in which the absorbent article is loaded with a load of 4 g/cm ² from the side of the front sheet. structure.

The absorbent article according to any one of the above aspects, wherein the joining of the front sheet and the lower sheet is intermittently performed in a direction in which the ridge portion extends.

The absorbent article according to any one of the above-mentioned items, wherein the width of the absorbent body is larger than the width of the front sheet and the Any one of the widths of the lower sheet is narrow, and each side edge of the absorbent body is linear in the central portion of at least the longitudinal direction of the absorbent article, and extends from the ridge portion and the concave portion The directions are roughly parallel.

The absorbent article according to any one of the above aspects, wherein the side edges of the absorbent article have a combined curve shape, and the absorbent article is in a front region of the longitudinal direction thereof and In the rear region, each side edge is convexly curved toward the outer side in the width direction, and in the central portion in the longitudinal direction, each side edge is convexly curved toward the inner side in the width direction, whereby the width of the central portion in the longitudinal direction is the narrowest.

The absorbent article according to any one of the above aspects, wherein the front sheet is joined to the back sheet at a peripheral portion of the absorbent article, and the front sheet is The entire area of the region on the inner side of the peripheral portion has the above-described uneven structure.

The absorbent article according to any one of the above aspects, wherein the absorbent article has a load of 20 g/cm ² from the side of the front sheet, the convex portion The hollow structure can be maintained.

The absorbent article according to any one of the above aspects, wherein the absorbent body comprises an absorbent sheet comprising a fibrous material and a water-absorptive polymer.

The absorbent article according to the above aspect, wherein the absorbent body comprises a laminate in which the absorbent sheet is laminated in two or more layers.

The absorbent article according to any one of the above aspects, wherein the thickness of the absorbent body is preferably 0.1 mm or more, more preferably 0.5 mm or more, and further preferably 5 mm or less. More preferably, it is 2 mm or less, and further preferably 0.1 mm or more and 5 mm or less, and further preferably 0.5 mm or more and 2 mm or less.

The absorbent article according to any one of the above aspects, wherein the lower sheet contains an apparent density of 0.005 g/cm ³ or more and 0.5 g/cm ³ or less, particularly 0.01 g/ A fluffy non-woven fabric of cm ³ or more and 0.1 g/cm ³ or less.

The absorbent article according to any one of the above aspects, wherein the nonwoven fabric comprises fibers having a large diameter portion and a small diameter portion having different fiber diameters.

The absorbent article according to any one of the above aspects, wherein the non-woven fabric includes a plurality of fusion portions formed by thermally fusing the intersections of the constituent fibers.

The absorbent article according to any one of the above aspects, wherein the fiber density D _13c of the side region is relative to the fiber density D _{13a of} the top region or the fiber of the bottom region The ratio of the density D _13b (D _13c /D _13a , D _13c /D _13a ) is preferably 0.15 or more and 0.9 or less, and more preferably 0.2 or more and 0.8 or less.

<16> above <1> to <15> of the absorbent article according to any one of the aspects, wherein the fiber density of said top area D _13a is preferably 90 / mm ² or more and 200 / mm ² or less, and further It is preferably 100 pieces/mm ² or more and 180 pieces/mm ² or less.

<17> above <1> to <16> The absorbent article of any one of claims, wherein the fiber density of the bottom of the area D _13b is preferably 80 / mm ² or more and 200 / mm ² or less, and further It is preferably 90 pieces/mm ² or more and 180 pieces/mm ² or less.

<18> above <1> to <17> The absorbent article according to any of one of claims, wherein the fiber density of the side area 30 is preferably D _13c / mm ² and not more than 80 / mm ² or less, Further, it is preferably 40 pieces/mm ² or more and 70 pieces/mm ² or less.

The absorbent article according to any one of the above aspects, wherein the high elongation fiber is a core-sheath type composite fiber having heat fusion properties.

The absorbent article according to any one of the above-mentioned items, wherein the high elongation fiber has a fineness of preferably 1.0 dtex or more and 10.0 dtex or less, more preferably 2.0 dtex. Above and below 8.0dtex.

The absorbent article according to any one of the above aspects, wherein the above The ratio of the above-mentioned high elongation fibers in the nonwoven fabric is preferably 50% by mass or more and 100% by mass or less, and more preferably 80% by mass or more and 100% by mass or less.

The absorbent article according to any one of the above-mentioned <1>, wherein the constituent fibers are adjacent to each other in the constituent fibers of the non-woven fabric. There is a large diameter portion having a large fiber diameter sandwiched between two small diameter portions having a small fiber diameter.

<23> The absorbent article according to the above <22>, wherein, when one of the constituent fibers is focused on, a plurality of the large diameter portions are provided between the adjacent fusion portions.

<24> The absorbent article according to the above <22>, wherein, in the case of one of the constituent fibers, it is preferable to have one or more and five adjacent ones of the adjacent fusion portions. Further, the large diameter portion described below is preferably one or more and three or less.

<25> The <22> The absorbent article according to the described <24>, in which the small-diameter portion 16 of the fiber diameter (L ₁₆₎ with respect to the large-diameter portion of the fiber diameter (L ₁₇₎ The ratio (L ₁₆ /L ₁₇ ) is preferably 0.5 or more and 0.8 or less, and more preferably 0.55 or more and 0.7 or less.

The absorbent article according to any one of the above aspects, wherein the small diameter portion has a fiber diameter (diameter L ₁₆ ) of preferably 5 μm or more and 28 μm or less, more preferably 6.5. It is not more than μm and not more than 20 μm, and particularly preferably 7.5 μm or more and 16 μm or less.

In the absorbent article according to any one of the above aspects, the fiber diameter (diameter L ₁₇ ) of the large diameter portion is preferably 10 μm or more and 35 μm or less, and more preferably 13 μm. The above is 25 μm or less, and particularly preferably 15 μm or more and 20 μm or less.

The absorbent article according to any one of the above-mentioned items, wherein the small-diameter portion adjacent to the fusion portion is in contact with the large-diameter portion The change point is disposed within a range of one third of the interval T between the fusion portion and the adjacent fusion portion.

The absorbent article according to any one of the above aspects, wherein the nonwoven fabric comprises fibers having a large diameter portion and a small diameter portion having different fiber diameters, and the nonwoven fabric is formed. Among the constituent fibers constituting the side region, the number of fibers having a change point from the small-diameter portion adjacent to the fusion portion to the large-diameter portion has the above-described change point among the constituent fibers constituting the top region. The number of fibers and the number of fibers having the above-described change points among the constituent fibers constituting the bottom region are large.

The absorbent article according to the above aspect, wherein the number of fibers (N _13c ) having the change point in the constituent fibers constituting the side region is the same as the constituent fibers constituting the top region. The ratio of the number of fibers (N _13a ) at the point of change or the number of fibers (N _13b ) having the above-described change points in the constituent fibers of the bottom region (N _13c /N _13a , N _13c /N _13b ) It is preferably 2 or more and 20 or less, and more preferably 5 or more and 20 or less.

The absorbent article according to the above <30>, wherein the number of fibers (N _13a ) having the change point among the constituent fibers constituting the top region is preferably one or more and 15 or less, and further It is preferably 5 or more and 15 or less.

<32> The absorbent article according to the above-mentioned <30>, wherein the number of fibers (N _13b ) having the change point among the constituent fibers constituting the bottom region is preferably one or more and 15 Hereinafter, it is more preferably 5 or more and 15 or less.

The absorbent article according to any one of the above-mentioned <30>, wherein the number of fibers (N _13c ) having the change point among the constituent fibers constituting the side region is preferably 5 More than 20 roots, more preferably 10 or more and 20 or less.

The absorbent article according to any one of the above aspects, wherein the sheet thickness T _{S of the} nonwoven fabric is preferably 0.5 mm or more and 7 mm or less, more preferably 1.0 mm or more and 5 mm. the following.

The absorbent article according to any one of the above aspects, wherein the layer thickness T _L1 of the top region of the nonwoven fabric is preferably 0.1 mm or more and 3.0 mm or less, more preferably 0.2. Above mm and below 2.0mm.

The absorbent article according to any one of the above aspects, wherein the layer thickness T _L2 of the bottom region of the nonwoven fabric is preferably 0.1 mm or more and 3.0 mm or less, more preferably 0.2. Above mm and below 2.0mm.

The absorbent article according to any one of the above aspects, wherein the layer thickness T _L3 of the side portion of the nonwoven fabric is preferably 0.1 mm or more and 3.0 mm or less, more preferably 0.2 mm or more and 2.0 mm or less.

The absorbent article according to any one of the aspects of the present invention, wherein the non-woven fabric has the direction in which the ridge portion and the concave portion extend, that is, the X direction, and The direction orthogonal to the Y direction, and the distance between the tops of the ridge portions adjacent in the Y direction is preferably 1 mm or more and 15 mm or less, more preferably 1.5 mm or more and 10 mm or less.

The absorbent article according to any one of the above aspects, wherein the height of the ridge portion is preferably 0.5 mm or more and 5 mm or less, more preferably 1 mm or more and 3 mm or less.

The absorbent article according to any one of the above-mentioned items, wherein the basis weight of the nonwoven fabric is preferably 15 g/m ² or more and 50 g/m ² or less, based on the average value of the whole. More preferably, it is 20 g/m ² or more and 40 g/m ² or less.

The absorbent article according to any one of the above aspects, wherein the lower sheet is a set of fibers comprising a thermoplastic resin disposed between the front sheet and the absorbent body. The second sheet of the body.

The absorbent article according to any one of the above aspects, wherein the lower sheet comprises an aggregate of fibers, and the aggregate of the fibers has a higher fiber density than the front sheet. The fiber density of the above non-woven fabric.

The absorbent article according to the above <42>, wherein the constituent fibers of the lower sheet are aligned in the longitudinal direction.

<44> The absorbent article according to the above <42>, wherein the lower sheet comprises a long fiber nonwoven fabric.

<45> The absorbent article according to any one of the above aspects, wherein the lower sheet has a higher hydrophilicity than the front sheet.

The absorbent article according to any one of the above aspects, wherein the thickness of the absorbent body is preferably 1 mm or more, more preferably 2 mm or more, further preferably 15 mm or less. It is preferably 10 mm or less, more preferably 1 mm or more and 15 mm or less, further preferably 2 mm or more and 10 mm or less.

The absorbent article according to any one of the above aspects, wherein the nonwoven fabric comprises fibers having a large diameter portion and a small diameter portion having different fiber diameters.

The absorbent article according to any one of the above aspects, wherein the non-woven fabric includes a plurality of fusion portions formed by thermally fusing the intersections of the constituent fibers.

The absorbent article according to any one of the above aspects, wherein the constituting fibers of the nonwoven fabric comprise high elongation fibers.

The absorbent article according to the above <49>, wherein the high elongation fiber is a core-sheath type composite fiber having heat fusion properties.

The absorbent article according to the above-mentioned item, wherein the high elongation fiber has a fineness of 1.0 dtex or more and 10.0 dtex or less, preferably 2.0 dtex or more and 8.0 dtex or less in the raw material stage.

The absorbent article according to any one of the items <49> to <51>, wherein The ratio of the high elongation fibers 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.

The absorbent article according to any one of the above-mentioned items, wherein the constituent fibers of the non-woven fabric are sandwiched between adjacent fusion portions when focusing on one constituent fiber. A large diameter portion having a large fiber diameter of two small diameter portions having a small fiber diameter.

The absorbent article according to the above aspect, wherein the one of the constituent fibers has a plurality of large diameter portions between the adjacent fusion portions.

<55> The absorbent article according to the above-mentioned <53>, wherein the constituent fibers of the non-woven fabric are one or more and 5 between adjacent fusion portions when focusing on one constituent fiber 11. The one or more large diameter portions are preferably one or more and three or less.

The absorbent article according to any one of the above aspects, wherein the fiber diameter (diameter L ₁₆ ) of the small diameter portion is larger than the fiber diameter (diameter L ₁₇ ) of the large diameter portion. The ratio (L ₁₆ /L ₁₇ ) is preferably 0.5 or more and 0.8 or less, and more preferably 0.55 or more and 0.7 or less.

The absorbent article according to any one of the above-mentioned, wherein the fiber diameter (diameter L ₁₆ ) of the small diameter portion is larger than the fiber diameter (diameter L ₁₇ ) of the large diameter portion. The ratio (L ₁₆ /L ₁₇ ) is preferably 0.5 or more and 0.8 or less, and more preferably 0.55 or more and 0.7 or less.

The absorbent article according to any one of the above aspects, wherein the small diameter portion has a fiber diameter (diameter L ₁₆ ) of preferably 5 μm or more and 28 μm or less, more preferably 6.5. It is not more than μm and not more than 20 μm, and particularly preferably 7.5 μm or more and 16 μm or less.

The absorbent article according to any one of the above-mentioned items, wherein the fiber diameter (diameter L ₁₇ ) of the large diameter portion is preferably 10 μm or more and 35 μm or less, and more preferably 13 μm. The above is 25 μm or less, and particularly preferably 15 μm or more and 20 μm or less.

The absorbent article according to any one of the above-mentioned, wherein the constituent fibers of the non-woven fabric are oriented from a small diameter portion adjacent to the fusion portion to a large diameter when focusing on one constituent fiber. The change point of the portion is disposed within a range of one third of the interval T between the fusion portion and the adjacent fusion portion.

The absorbent article according to any one of the above aspects, wherein the non-woven fabric has a top region, a bottom region, and a side between them when viewed in a cross section in the thickness direction Z. a portion region, and a top portion of the ridge portion is formed by a top portion, and a bottom portion of the concave portion is formed by a bottom portion.

The absorbent article according to the above <61>, wherein the side region has a fiber density lower than a fiber density of the top region and a fiber density of the bottom region.

The absorbent article according to the above <61> or <62> wherein the fiber density (D _13c ) of the side region is relative to the fiber density (D _13a ) of the top region or the fiber of the bottom region The ratio of the density (D _13b ) (D _13c /D _13a , D _13c /D _13a ) is preferably 0.15 or more and 0.9 or less, and more preferably 0.2 or more and 0.8 or less.

The absorbent article according to any one of the above-mentioned items, wherein the top portion _13a preferably has a fiber density (D _13a ) of 90 pieces/mm ² or more and 200 pieces/mm ^{2 .} Hereinafter, it is more preferably 100 pieces/mm ² or more and 180 pieces/mm ² or less.

The absorbent article according to any one of the above aspects, wherein the bottom portion _13b preferably has a fiber density (D _13b ) of 80 pieces/mm ² or more and 200 pieces/mm ^{2 .} Hereinafter, it is more preferably 90 pieces/mm ² or more and 180 pieces/mm ² or less.

The absorbent article according to any one of the above aspects, wherein the side portion 13c has a fiber density (D _13c ) of preferably 30 pieces/mm ² or more and 80 pieces/mm. ² or less, further preferably 40 pieces/mm ² or more and 70 pieces/mm ² or less.

The absorbent article according to any one of the above-mentioned <60>, wherein the number of fibers having a change point among the constituent fibers constituting the side region is formed to constitute the top region. The number of fibers having a change point in the constituent fibers and the number of fibers having a change point among the constituent fibers constituting the bottom region are large.

The absorbent article according to any one of the above aspects, wherein the number of fibers (N _13c ) having a change point among the constituent fibers constituting the side region is opposite to the top portion The ratio of the number of fibers (N _13a ) having a change point in the constituent fibers of the region or the number of fibers (N _13b ) having a change point among the constituent fibers constituting the bottom region (N _13c /N _13a , N _{13c )} /N _13b ) is preferably 2 or more and 20 or less, and more preferably 5 or more and 20 or less.

The absorbent article according to any one of the above-mentioned <62>, wherein the specific value of the number of fibers having a change point of the nonwoven fabric has a change in the constituent fibers constituting the top region. The number of fibers (N _13a ) of the dots is preferably 1 or more and 15 or less, and more preferably 5 or more and 15 or less.

The absorbent article according to any one of the above-mentioned <62>, wherein the specific value of the number of fibers having a change point of the nonwoven fabric has a change in the constituent fibers constituting the bottom region. The number of fibers (N _13b ) at the point 18 is preferably one or more and 15 or less, and more preferably five or more and 15 or less.

The absorbent article according to any one of the above aspects, wherein the specific value of the number of fibers having a change point of the nonwoven fabric has a constituent fiber constituting the side region. The number of fibers (N _13c ) at the point of change 18 is preferably 5 or more and 20 or less, and more preferably 10 or more and 20 or less.

The absorbent article according to any one of the above-mentioned items, wherein the sheet thickness T _S of the nonwoven fabric is 0.5 mm or more and 7 mm or less, preferably 1.0 mm or more and 5 mm or less.

The absorbent article according to any one of the above aspects, wherein the layer thickness T _L1 of the top region is 0.1 mm or more and 3.0 mm or less, preferably 0.2 mm or more and 2.0 mm. the following.

The absorbent article according to any one of the above aspects, wherein the layer thickness T _L2 of the bottom region is 0.1 mm or more and 3.0 mm or less, preferably 0.2 mm or more and 2.0 mm. the following.

The absorbent article according to any one of the above aspects, wherein the side layer region has a layer thickness T _L3 of 0.1 mm or more and 3.0 mm or less, preferably 0.2 mm or more and 2.0. Below mm.

The absorbent article according to any one of the above aspects, wherein the distance between the tops of the ridge portions adjacent to each other in the width direction Y is 1 mm or more and 15 mm or less. It is 1.5 mm or more and 10 mm or less.

The absorbent article according to any one of the above aspects, wherein the height H of the ridge portion is 0.5 mm or more and 5 mm or less, preferably 1 mm or more and 3 mm or less.

The absorbent article according to any one of the above-mentioned items, wherein the basis weight of the nonwoven fabric is more preferably 15 g/m ² or more and 50 g/ m ² or less is preferably 20 g/m ² or more and 40 g/m ² or less.

The absorbent article according to any one of the above aspects, wherein the lower sheet is a spunbonded nonwoven fabric or a spunlace nonwoven fabric.

The absorbent article according to any one of the above aspects, wherein the lower sheet or the second sheet as the lower sheet has a fiber density (D ₆ ) relative to The ratio (D _13a / D ₆ ) of the fiber density (D _13a ) of the top (top region 13a) of the above-mentioned ridge portion is preferably 1.1 or more, and more preferably 2 or more.

The absorbent article according to any one of the above aspects, wherein the absorbent body has a fiber density higher than a portion located on both sides in the width direction at a plurality of portions in the width direction. a density portion, and each of the high density portions is formed on the ridge portion The position where the top overlaps.

The absorbent article according to the above aspect, wherein the high-density portion extends in the longitudinal direction and forms a plurality of rows in the width direction, and each of the high-density portions is along the longitudinal direction and the ridge portion. The tops overlap continuously.

The absorbent article according to the above-mentioned item <81>, wherein the number of the high-density portions which are formed in the width direction Y of the absorbent body and overlaps the top of the ridge portion of the front sheet is The plurality of roots are preferably three or more, more preferably five or more, and still more preferably eight or more.

In the absorbent article according to any one of the above aspects, the length of the high-density portion in the width direction Y is preferably 20 mm or more, and more preferably 50 mm or more.

The absorbent article according to any one of the above-mentioned items, wherein the high-density portion has a shape in which a high-density portion having a long length in the longitudinal direction X is along the longitudinal direction of the absorbent body. Formed continuously.

The absorbent article according to any one of the above aspects, wherein the length of the high-density portion continuous in the longitudinal direction X is preferably 30 in the same direction as the length of the absorbent body. More than %, more preferably 50% or more, and still more preferably 100%.

The absorbent article according to any one of the above aspects, wherein the high-density portion has a long shape in the longitudinal direction X and intermittently along the longitudinal direction X of the absorbent body 4. There are a plurality of forms.

In the absorbent article according to any one of the above aspects, the length L3 of the longitudinal direction X of the high-density portion is preferably 0.5 mm or more, and more preferably 1 mm or more.

The absorbent article according to any one of the above-mentioned items, wherein the length L3 of the high-density portion is between the length L3 and the high-density portion adjacent to each other in the longitudinal direction X. The total length L5 of the length is preferably 5% or more, more preferably 30% or more.

<90> The <81> The absorbent article of one of claims to <89>, in which the density (D ₄₎ with respect to the density of the low density portion of the high-density portion of the (D ₃₎ of the ratio (D ₃ /D ₄ ) is preferably 1.5 or more, and more preferably 3 or more.

The absorbent article according to any one of the above aspects, wherein the front sheet and the lower sheet contain fibers of a thermoplastic resin, and the concave portion is thermally fused. The lower side sheet is joined, and the constituent fibers of the front sheet and the lower sheet do not maintain the form of fibers in the joint portion.

The absorbent article according to any one of the above aspects, wherein the joint portion between the concave portion and the lower sheet is liquid-impermeable.

The absorbent article according to any one of the above aspects, wherein the joint portion is continuously formed in the longitudinal direction.

<94> An absorbent article comprising: a front sheet which forms a liquid permeability of a skin contact surface, a back sheet, and an absorbent body interposed between the sheets, and has a longitudinal direction In the width direction, the front sheet includes a stripe-like ridge portion extending in the longitudinal direction and a non-woven fabric having a concave-convex structure in which the concave strip portions are alternately arranged in the width direction, and the concave strip portion and the adjacent lower side In the sheet joining, the ridge portion has a hollow structure between the lower sheet and the lower sheet, and the lower sheet includes an aggregate of fibers, and the aggregate of the fibers has a higher fiber density than the non-woven fabric constituting the front sheet Fiber density.

The absorbent article according to the above <94>, wherein the constituent fibers of the lower sheet are aligned in the longitudinal direction.

<96> The absorbent article according to the above <94>, wherein the lower sheet comprises a long fiber nonwoven fabric.

The absorbent article according to any one of the above aspects, wherein the lower sheet has a higher hydrophilicity than the front sheet.

The absorbent article according to any one of the above aspects, wherein the thickness of the absorbent body is preferably 1 mm or more, more preferably 2 mm or more, further preferably 15 mm or less. It is preferably 10 mm or less, more preferably 1 mm or more and 15 mm or less, further preferably 2 mm or more and 10 mm or less.

The absorbent article according to any one of the above aspects, wherein the nonwoven fabric comprises fibers having a large diameter portion and a small diameter portion having different fiber diameters.

The absorbent article of any one of the above-mentioned <94> to <99>, wherein The non-woven fabric includes a plurality of fusion portions formed by thermally fusing the intersections of the constituent fibers.

The absorbent article according to any one of the above-mentioned <94>, wherein the constituting fibers of the nonwoven fabric comprise high elongation fibers.

The absorbent article according to the above <101>, wherein the high elongation fiber is a core-sheath type composite fiber having heat fusion properties.

The absorbent article according to the above-mentioned <101>, wherein the high elongation fiber has a fineness of 1.0 dtex or more and 10.0 dtex or less, preferably 2.0 dtex or more and 8.0 dtex or less in the raw material stage.

The absorbent article according to any one of the above-mentioned, wherein the ratio of the high elongation fibers 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.

The absorbent article according to any one of the above-mentioned <94>, wherein the constituent fibers of the nonwoven fabric are sandwiched between adjacent fusion portions when focusing on one constituent fiber. A large diameter portion having a large fiber diameter of two small diameter portions having a small fiber diameter.

The absorbent article according to the above <105>, wherein the one constituent fiber has a plurality of large diameter portions between adjacent fusion portions.

The absorbent article according to the above-mentioned <105>, wherein the constituent fibers of the nonwoven fabric are focused on one constituent fiber 11 and are adjacent to each other. One or more and five or less large diameter portions are provided, and it is preferable to have one or more and three or less.

The absorbent article according to any one of the above-mentioned <10>, wherein the fiber diameter (diameter L ₁₆ ) of the small diameter portion is larger than the fiber diameter (diameter L ₁₇ ) of the large diameter portion. The ratio (L ₁₆ /L ₁₇ ) is preferably 0.5 or more and 0.8 or less, and more preferably 0.55 or more and 0.7 or less.

The absorbent article according to any one of the above-mentioned <10>, wherein the fiber diameter (diameter L ₁₆ ) of the small diameter portion is larger than the fiber diameter (diameter L ₁₇ ) of the large diameter portion. The ratio (L ₁₆ /L ₁₇ ) is preferably 0.5 or more and 0.8 or less, and more preferably 0.55 or more and 0.7 or less.

In the absorbent article according to any one of the above-mentioned items, the fiber diameter (diameter L ₁₆ ) of the small diameter portion is preferably 5 μm or more and 28 μm or less, and more preferably 6.5. It is not more than μm and not more than 20 μm, and particularly preferably 7.5 μm or more and 16 μm or less.

The absorbent article according to any one of the above-mentioned <10>, wherein the large diameter portion has a fiber diameter (diameter L ₁₇ ) of preferably 10 μm or more and 35 μm or less, more preferably 13 μm. The above is 25 μm or less, and particularly preferably 15 μm or more and 20 μm or less.

The absorbent article according to any one of the above-mentioned <10>, wherein the constituent fibers of the non-woven fabric are oriented from a small diameter portion adjacent to the fusion portion to a large diameter when focusing on one constituent fiber. The change point of the portion is disposed within a range of one third of the interval T between the fusion portion and the adjacent fusion portion.

The absorbent article of any one of the above-mentioned <94> to <112>, wherein When the non-woven fabric is viewed in a cross section in the thickness direction Z, it has a top region, a bottom region, and a side region between the same, and the top of the ridge portion is formed by the top region, and the bottom portion of the concave portion is the bottom region. form.

The absorbent article according to the above <113>, wherein the side region has a fiber density lower than a fiber density of the top region and a fiber density of the bottom region.

The absorbent article according to the above <113>, wherein the fiber density (D _13c ) of the side region is relative to the fiber density (D _13a ) of the top region or the fiber of the bottom region The ratio of the density (D _13b ) (D _13c /D _13a , D _13c /D _13a ) is preferably 0.15 or more and 0.9 or less, and more preferably 0.2 or more and 0.8 or less.

The absorbent article according to any one of the above-mentioned <11>, wherein the top region 13a preferably has a fiber density (D _13a ) of 90 / mm ² or more and 200 / mm ² Hereinafter, it is more preferably 100 pieces/mm ² or more and 180 pieces/mm ² or less.

The absorbent article according to any one of the above-mentioned <11>, wherein the bottom portion _13b preferably has a fiber density (D _13b ) of 80 pieces/mm ² or more and 200 pieces/mm ^{2 .} Hereinafter, it is more preferably 90 pieces/mm ² or more and 180 pieces/mm ² or less.

The absorbent article according to any one of the above-mentioned <11>, wherein the side region 13c preferably has a fiber density (D _13c ) of 30 pieces/mm ² or more and 80 pieces/mm. ² or less, further preferably 40 pieces/mm ² or more and 70 pieces/mm ² or less.

<119> The absorbent article according to any one of the above-mentioned <11> to <118>, wherein the number of fibers having a change point among the constituent fibers constituting the side region is formed to be a constituent fiber constituting the top region. The number of fibers having a change point therein and the number of fibers having a change point of constituent fibers constituting the bottom region are large.

The absorbent article according to any one of the above aspects, wherein the number of fibers (N _13c ) having a change point among the constituent fibers constituting the side region is opposite to the top portion The ratio of the number of fibers (N _13a ) having a change point in the constituent fibers of the region or the number of fibers (N _13b ) having a change point among the constituent fibers constituting the bottom region (N _13c /N _13a , N _{13c )} /N _13b ) is preferably 2 or more and 20 or less, and more preferably 5 or more and 20 or less.

The absorbent article according to any one of the above-mentioned <11>, wherein the specific value of the number of fibers having a change point of the nonwoven fabric has a change in the constituent fibers constituting the top region. The number of fibers (N _13a ) of the dots is preferably 1 or more and 15 or less, and more preferably 5 or more and 15 or less.

The absorbent article according to any one of the above-mentioned <11>, wherein the specific value of the number of fibers having a change point of the nonwoven fabric has a change in constituent fibers constituting the bottom region. The number of fibers (N _13b ) at the point 18 is preferably one or more and 15 or less, and more preferably five or more and 15 or less.

The absorbent article according to any one of the above-mentioned <11>, wherein the specific value of the number of fibers having a change point of the nonwoven fabric has a constituent fiber constituting the side region. The number of fibers (N _13c ) at the point of change 18 is preferably 5 or more and 20 or less, and more preferably 10 or more and 20 or less.

The absorbent article according to any one of the above-mentioned <94>, wherein the sheet thickness T _S of the nonwoven fabric is 0.5 mm or more and 7 mm or less, preferably 1.0 mm or more and 5 mm or less.

The absorbent article according to any one of the above aspects, wherein the top layer has a layer thickness T _L1 of 0.1 mm or more and 3.0 mm or less, preferably 0.2 mm or more and 2.0 mm. the following.

The absorbent article according to any one of the above aspects, wherein the layer thickness T _L2 of the bottom region is 0.1 mm or more and 3.0 mm or less, preferably 0.2 mm or more and 2.0 mm. the following.

The absorbent article according to any one of the above aspects, wherein the side layer region has a layer thickness T _L3 of 0.1 mm or more and 3.0 mm or less, preferably 0.2 mm or more and 2.0. Below mm.

The absorbent article according to any one of the above aspects, wherein the distance between the tops of the ridge portions adjacent to each other in the width direction Y is 1 mm or more and 15 mm or less. It is 1.5 mm or more and 10 mm or less.

In the absorbent article according to any one of the above aspects, the height H of the ridge portion is 0.5 mm or more and 5 mm or less, preferably 1 mm or more and 3 mm or less.

In the absorbent article according to any one of the above aspects, the basis weight of the non-woven fabric is preferably 15 g/m ² or more and 50 g/ m ² or less is preferably 20 g/m ² or more and 40 g/m ² or less.

The absorbent article according to any one of the above aspects, wherein the lower sheet is a spunbonded nonwoven fabric or a spunlace nonwoven fabric.

The absorbent article according to any one of the above aspects, wherein the lower sheet or the second sheet as the lower sheet has a fiber density (D ₆ ) relative to The ratio (D _13a / D ₆ ) of the fiber density (D _13a ) of the top (top region 13a) of the above-mentioned ridge portion is preferably 1.1 or more, and more preferably 2 or more.

The absorbent article according to any one of the above-mentioned items, wherein the absorbent body has a fiber density higher than a portion located on both sides in the width direction at a plurality of portions in the width direction. The density portion is formed at a position overlapping the top of the ridge portion.

The absorbent article according to the above aspect, wherein the high-density portion extends in the longitudinal direction and forms a plurality of rows in the width direction, and each of the high-density portions is along the longitudinal direction and the ridge The tops of the sections overlap continuously.

The absorbent article according to the above-mentioned <133>, wherein the number of the high-density portions which are formed in the width direction Y of the absorbent body and overlaps the top of the ridge portion of the front sheet is The plurality of roots are preferably three or more, more preferably five or more, and still more preferably eight or more.

The absorbent article of any one of the above-mentioned <133> to <135>, wherein The length of the high-density portion in the width direction Y is preferably 20 mm or more, and more preferably 50 mm or more.

The absorbent article according to any one of the above-mentioned items, wherein the high-density portion having a shape elongated in the longitudinal direction X is along the longitudinal direction of the absorbent body. X is formed continuously.

The absorbent article according to any one of the above-mentioned items, wherein the length of the high-density portion continuous in the longitudinal direction X is preferably 30 in the same direction as the length of the absorbent body. More than %, more preferably 50% or more, and still more preferably 100%.

The absorbent article according to any one of the above-mentioned items, wherein the high-density portion has a shape elongated in the longitudinal direction X and intermittently along the longitudinal direction X of the absorbent body 4. There are a plurality of forms.

In the absorbent article according to any one of the above aspects, the length L3 of the longitudinal direction X of the high-density portion is preferably 0.5 mm or more, and more preferably 1 mm or more.

The absorbent article according to any one of the above-mentioned items, wherein the length L3 of the high-density portion is between the length L3 and the high-density portion adjacent in the longitudinal direction X. The total length L5 of the length is preferably 5% or more, more preferably 30% or more.

<142> The <133> to <141> in the absorbent article of any one of the aspects, wherein the density (D ₄₎ with respect to the density of the low density portion of the high-density portion of the (D ₃₎ of the ratio (D ₃ /D ₄ ) is preferably 1.5 or more, and more preferably 3 or more.

The absorbent article according to any one of the above aspects, wherein the front sheet and the lower sheet comprise fibers of a thermoplastic resin, and the concave portion is thermally fused. The lower side sheet is joined, and the constituent fibers of the front sheet and the lower sheet do not maintain the form of fibers in the joint portion.

The absorbent article according to any one of the above aspects, wherein the joint portion between the concave portion and the lower sheet is liquid-impermeable.

The absorbent article according to any one of the above aspects, wherein the joint portion is continuously formed in the longitudinal direction.

[Industrial availability]

According to the present invention, it is possible to provide an absorbent article in which the uneven structure of the front sheet easily follows the action of the wearer, and the air permeability on the opposite side of the skin is good, and the stuffiness in the worn state is less likely to occur.

Moreover, according to the absorbent article of the present invention, the unpleasant feeling caused by the excretion liquid contacting the skin of the wearer can be reliably suppressed, and the absorption capacity of the absorbent body can be effectively utilized.

1‧‧‧nonwoven

2‧‧‧Front sheet

11‧‧‧Fiber

13‧‧‧Rocks

14‧‧‧ recessed section

14s‧‧‧ joints

H‧‧‧ Height

X‧‧‧ length direction

Y‧‧‧Width direction

Z‧‧‧ Thickness direction

Claims (31)

An absorbent article comprising a front sheet which forms a liquid permeability of a skin contact surface, a back sheet, and an absorbent body interposed between the two sheets, and having a longitudinal direction and a width direction, the front surface The sheet material includes a strip-shaped ridge portion extending in the longitudinal direction and a non-woven fabric having a concave-convex structure in which the concave strip portions are alternately arranged in the width direction, and the concave strip portion is joined to the adjacent lower side sheet, and the non-woven fabric is joined to the sheet. At least the high elongation fiber is used as a raw material, the lower sheet material comprises an aggregate of fibers of a thermoplastic resin, and the ridge portion has a hollow structure between the nonwoven fabric and the lower sheet, and the nonwoven fabric has a top region and a bottom portion. a region, and a side region between the same, wherein a top portion of the ridge portion is formed by the top portion, a bottom portion of the concave portion is formed by the bottom portion, and a fiber density of the side portion is higher than a fiber of the top portion Any of the density and the fiber density of the above bottom region are low. The absorbent article according to claim 1, wherein the central region in the width direction of the absorbent article has at least the uneven structure. The absorbent article of claim 1, wherein the ridge portion maintains a hollow structure in a state in which the absorbent article is loaded with a load of 4 g/cm ² from the side of the front sheet. The absorbent article of claim 1, wherein the joining of the front sheet and the lower sheet is intermittently performed in a direction in which the ridge portion extends. The absorbent article according to claim 1, wherein in the central portion of at least the longitudinal direction of the absorbent article, the width of the absorbent body is larger than the width of the front sheet and Any one of the widths of the lower sheet is narrow, and each side edge of the absorbent body is linear in the central portion of at least the longitudinal direction of the absorbent article, and extends from the ridge portion and the concave portion The directions are roughly parallel. The absorbent article according to claim 1, wherein each side edge of the absorbent article has a shape of a combined curve, and the absorbent article is curved in a convex shape in a front direction and a rear region in a longitudinal direction thereof. Further, in the central portion in the longitudinal direction, each side edge is convexly curved toward the inner side in the width direction, whereby the width of the central portion in the longitudinal direction becomes the narrowest. The absorbent article according to claim 1, wherein the top sheet is joined to the back sheet at a peripheral portion of the absorbent article, and the front sheet has the uneven structure over a region inward of the peripheral portion. . The absorbent article of claim 1, wherein the ridge portion maintains a hollow structure in a state in which the absorbent article is loaded with a load of 20 g/cm ² from the side of the front sheet. The absorbent article of claim 1, wherein the nonwoven fabric comprises fibers having a large diameter portion and a small diameter portion having mutually different fiber diameters. The absorbent article according to claim 1, wherein the nonwoven fabric comprises a plurality of fusion portions formed by thermally fusing the intersections of the constituent fibers. The absorbent article of the requested item 1, wherein the fiber density of the side area D _13c relative to the fiber density of said top area D _13a, or the ratio of fiber area density of said bottom i.e. the D _13b D _13c / D _13a or D _13c /D _13b is 0.15 or more and 0.9 or less. The absorbent article of claim 1, wherein the constituent fibers are sandwiched between adjacent fusion portions when one of the constituent fibers of the nonwoven fabric is focused on The large diameter portion having a large fiber diameter in the two small diameter portions having a small fiber diameter. In the absorbent article of claim 12, when one of the constituent fibers is focused on, a plurality of the large diameter portions are provided between the adjacent fusion portions. The absorbent article according to claim 12, wherein the ratio of the fiber diameter L ₁₆ of the small-diameter portion to the fiber diameter L ₁₇ of the large-diameter portion, that is, L ₁₆ /L ₁₇ is 0.5 or more and 0.8 or less. The absorbent article according to claim 12, wherein the small diameter portion has a fiber diameter L ₁₆ of 5 μm or more and 28 μm or less. The absorbent article according to claim 12, wherein the large diameter portion has a fiber diameter L ₁₇ of 10 μm or more and 35 μm or less. The absorbent article of claim 12, wherein the non-woven fabric comprises fibers having a large diameter portion and a small diameter portion having mutually different fiber diameters, and wherein the non-woven fabric has a self-adjacent one of the constituent fibers constituting the side portion The number of fibers of the small diameter portion of the fusion portion to the large diameter portion is larger than the number of fibers having the change point among the constituent fibers constituting the top portion, and the constituent fibers constituting the bottom portion. The number of fibers of the above change points is large. The absorbent article according to claim 1, wherein the lower sheet is a second sheet disposed between the front sheet and the absorbent body and comprising an aggregate of fibers of a thermoplastic resin. The absorbent article of claim 1, wherein the lower side sheet comprises an aggregate of fibers, and the aggregate of the fibers has a fiber density higher than a fiber density of the nonwoven fabric constituting the front sheet. The absorbent article of claim 1, wherein the constituent fibers of the lower side sheet are aligned in the longitudinal direction. The absorbent article of claim 1, wherein the lower side sheet comprises long fibers not woven cloth. The absorbent article of claim 1, wherein the lower side sheet has a higher hydrophilicity than the front sheet. The absorbent article according to claim 1, wherein the plurality of portions of the absorbent body in the width direction have a high density portion having a higher fiber density than a portion on both sides in the width direction, and the high density portion is formed in the same manner as the above The position where the tops of the ridges overlap. The absorbent article according to claim 23, wherein the number of the high-density portions which are formed in the width direction of the absorbent body and overlaps with the top of the ridge portion of the front sheet is plural. The absorbent article according to claim 23 or 24, wherein the high-density portion having a shape elongated in the longitudinal direction as the high-density portion is continuously formed along the longitudinal direction of the absorbent body. The absorbent article according to claim 23, wherein the high-density portion has a shape elongated in the longitudinal direction, and a plurality of portions are intermittently formed along the longitudinal direction of the absorbent body. The absorbent article according to claim 23, wherein the high-density portion extends in the longitudinal direction and forms 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 claim 1, wherein the front sheet and the lower sheet comprise fibers of a thermoplastic resin, and the concave portion is joined to the lower sheet by heat fusion, and the front portion is formed at the joint portion The constituent fibers of the sheet and the lower sheet do not maintain the form of the fibers. The absorbent article according to claim 1, wherein the joint portion between the concave strip portion and the lower side sheet is liquid-impermeable. The absorbent article of claim 1, wherein the joint portion is continuously formed in the longitudinal direction to make. The absorbent article of claim 1, wherein the ratio of the fiber density D ₆ of the lower sheet or the second sheet as the lower sheet to the fiber density D _13a of the top region is D ₆ /D _13a It is 1.1 or more.