Pant-type disposable diaper

Abstract

To provide an underpants type disposable diaper capable of being pulled up to a proper position and reducing liquid spill such as urine.SOLUTION: A diaper 1 comprises an absorbent body 10 and an exterior body 5. The exterior body 5 includes an outer layer nonwoven fabric 51 and an inner layer nonwoven fabric 52, and on each of an abdominal side part A and a back side part B, there is formed a folded part 51a obtained by folding the outer layer nonwoven fabric 51 to a skin facing surface side along a waist opening end. The exterior body 5 has a pair of side panels 15, the folded part 51a has an end part region joined by a junction 53. The side panel 15 has: a first region E1 formed of the folded part 51a; and a second region E2 which is adjacent to the first region E1 and where the inner layer nonwoven fabric is exposed. A friction coefficient of the outer layer nonwoven fabric 51 and a friction coefficient of the inner layer nonwoven fabric 52 are different from each other. A depth of a fold on the first region E1 is deeper than a depth of the fold on the second region E2.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a pant-type disposable diaper.

Background Art

[0002] Typically, a pant-type disposable diaper includes an absorbent body having an absorber for absorbing excrement such as urine, and a stretchable outer wrapper located on the non-skin-facing side of the absorbent body. Thereby, the outer wrapper fits around the wearer's waist and torso, providing a good wearing feeling.

[0003] Patent Document 1 discloses an absorbent article having an absorbent body and a torso portion, the bending rigidity of the inner non-woven fabric portion constituting the torso portion being higher than that of the skin-side sheet portion constituting the torso portion, for the purpose of making it difficult to leave rubber marks around the wearer's torso. It is also disclosed in the same document that by setting the coefficient of friction MIU of the skin-side sheet portion to at least 0.25, the article has flexibility.

[0004] Patent Document 2 discloses an absorbent article in which the outer sheet constituting the elastic belt region has a surface roughness of at least about 1.7 mm and the outer sheet is folded inward.

[0005] Patent Document 3 discloses a wearable article formed of a non-woven fabric substrate in which at least a part of the surface facing the clothing has a roughness of at least about 16.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0007] When wearing a panty-type disposable diaper, it is common to wear it by pulling up the outer cover. However, if the diaper is worn with the outer cover pulled up too much, the liquid discharge portion may come into close contact with the skin-facing surface of the diaper, and sufficient space required for liquid absorption may not be secured between the diaper and the wearer. As a result, liquid leakage such as urine leakage may occur. Regarding the prevention of leakage caused by appropriately positioning such a wearing position, the techniques of Patent Documents 1 to 3 have not been studied at all.

[0008] Therefore, an object of the present invention is to provide a panty-type disposable diaper that is easy to pull up to an appropriate position and reduces liquid leakage such as urine.

Means for Solving the Problems

[0009] The present invention has a longitudinal direction corresponding to the front-back direction of the wearer and a width direction orthogonal to the longitudinal direction, and has a ventral portion arranged on the ventral side of the wearer, a dorsal portion arranged on the dorsal side of the wearer, and a crotch portion located between the ventral portion and the dorsal portion. A panty-type disposable diaper having an absorbent body disposed in a region from the ventral portion to the dorsal portion, and an outer cover disposed on the non-skin-facing surface side of the absorbent body. The outer cover includes an outer layer nonwoven fabric forming the non-skin-facing surface of the outer cover and an inner layer nonwoven fabric forming the skin-facing surface of the outer cover. In each of the ventral portion and the dorsal portion, a folded-back portion is formed in which the outer layer nonwoven fabric is folded back along the waist opening end toward the skin-facing surface side. The outer cover includes a pair of side panels extending outward in the width direction of the absorbent body. In the folded-back portion of the side panel, at its end region, the non-skin-facing surface of the outer layer nonwoven fabric and the skin-facing surface of the inner layer nonwoven fabric are joined by a joining portion. The skin-facing surface of the side panel consists of a folded-back portion of the outer nonwoven fabric and has a first region located outward in the longitudinal direction from the joint portion and a second region adjacent to the first region inward in the longitudinal direction and where the inner nonwoven fabric is exposed on the skin-facing surface. The coefficient of friction of the outer nonwoven fabric and the coefficient of friction of the inner nonwoven fabric are different from each other. In a natural state, a plurality of folds extending in the longitudinal direction are formed along the width direction on at least the skin-facing surface of the side panel. The present invention provides a pant-type disposable diaper in which the depth of the fold in the first region is greater than the depth of the fold in the second region.

Advantages of the Invention

[0010] According to the present invention, there is provided a pant-type disposable diaper that is easy to pull up to an appropriate position and reduces liquid leakage such as urine.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0012] Hereinafter, the present invention will be described with reference to the drawings based on its preferred embodiments. FIGS. 1 and 2 show a pant-type disposable diaper (hereinafter also simply referred to as "diaper") 1 which is an embodiment of an absorbent article.

[0013] The diaper 1 shown in FIGS. 1 and 2 has a ventral part A arranged on the ventral side of the wearer in the worn state of the diaper 1, a dorsal part B arranged on the dorsal side of the wearer, and a crotch part C located between them. The diaper 1 has a longitudinal direction X corresponding to the direction in the front-back direction of the wearer, that is, the direction extending from the ventral part A through the crotch part C to the dorsal part B, and a width direction Y orthogonal to this. As shown in FIG. 2, the diaper 1 is formed symmetrically with respect to the longitudinal center line CL that extends in the longitudinal direction X and bisects the diaper 1 in the width direction Y.

[0014] The diaper 1 includes an absorbent body 10 having an absorber 4 to be described later in the central region in the width direction Y. In addition to this, it includes an outer wrapper 5 arranged on the side farther from the wearer's body than the absorbent body 10, that is, the non-skin facing side. The outer wrapper 5 in the present embodiment is continuously arranged from the ventral part A to the dorsal part B on the non-skin facing side of the absorbent body 10.

[0015] The outer wrapper 5 shown in FIG. 2 is formed to have a larger planar area than the absorbent body 10 and has an extension part extending outward from the peripheral edge of the absorbent body 10. Among this extension part, the parts located outside the width direction Y from the virtual extension lines of both side edges along the longitudinal direction X of the absorbent body 10 constitute a pair of side panels 15, 15. The pair of side panels 15 are formed on each of the ventral part A and the dorsal part B. The outer wrapper 5 has both side edge parts along the longitudinal direction X of the side panels 15 joined to each other in the ventral part A and the dorsal part B, respectively, thereby forming a pair of side seal parts S, S, a waist opening WH through which the wearer's torso passes, and a pair of leg openings LH through which the wearer's lower limbs pass.

[0016] As used herein, the "skin-facing surface" refers to the surface of the absorbent article or its component member (e.g., the top sheet) that faces the wearer's skin side when the absorbent article is worn, that is, the side relatively closer to the wearer's skin, and the "non-skin-facing surface" refers to the surface of the absorbent article or its component member that faces the side opposite to the skin side when the absorbent article is worn, that is, the side relatively farther from the wearer's skin. Here, the "when worn" means the state in which the normal proper wearing position, that is, the correct wearing position of the absorbent article is maintained.

[0017] Also as used herein, the "deployed and stretched state" means a state in which the diaper 1 is separated at the side seal portion S to be in a deployed state, and the deployed diaper 1 is expanded until each elastic member is stretched to the design dimensions (the same as the dimensions when flattened in a state where the influence of the elastic member is completely excluded). The "natural state" means a state in which no external force is applied to the diaper 1 or its component members.

[0018] As shown in FIG. 2, the absorbent main body 10 has a rectangular shape in a plan view in the deployed and stretched state of the diaper 1. The absorbent main body 10 is arranged in the longitudinal direction X continuously with the ventral side portion A, the crotch portion C, and the dorsal side portion B. The absorbent main body 10 is arranged in the central region in the width direction Y of the outer wrapper 5 with its longitudinal direction coinciding with the longitudinal direction X of the diaper 1. A part or all of the regions on the non-skin-facing surface of the absorbent main body 10 are joined to the skin-facing surface of the outer wrapper 5 by a joining method such as an adhesive.

[0019] As shown in FIG. 3, the absorbent main body 10 includes a liquid-permeable top sheet 2 that forms its skin-facing surface, a liquid-impermeable or liquid-hardly-permeable or water-repellent back sheet 3 that forms its non-skin-facing surface, and a liquid-retaining absorber 4 disposed between both sheets 2 and 3. The top sheet 2, the back sheet 3, and the absorber 4 are integrated by a known joining method such as an adhesive. The total length in the longitudinal direction X of the absorbent main body 10 is substantially the same as the total length in the longitudinal direction X of the absorber 4, and both end edges located before and after in the longitudinal direction of the absorber 4 are in the same positions as both end edges located before and after in the longitudinal direction of the absorbent main body 10.

[0020] The absorber 4 preferably includes at least an absorbent core 40 having liquid retention property, and further includes a core wrap sheet 41 covering the outer surface thereof. The absorber 4 has a rectangular shape in plan view, similar to the absorbent main body 10, and is arranged in the longitudinal direction X continuously from the ventral side portion A to the dorsal side portion B.

[0021] As the top sheet 2 and the back sheet 3, various types conventionally used for this kind of absorbent article can be used without particular limitation. For example, as the top sheet 2, various non-woven fabrics, perforated films, etc. can be used. For example, as the back sheet 3, a resin film, a laminate of a resin film and a non-woven fabric, etc. can be used. Typically, the absorbent core 40 is mainly composed of a water-absorbing material, and the water-absorbing material contains one or more selected from fiber materials such as wood pulp and water-absorbing polymers. The core wrap sheet 41 has liquid permeability and is typically made of paper, non-woven fabric, etc. The core wrap sheet 41 may be omitted.

[0022] As shown in FIG. 3, on both sides along the longitudinal direction X on the skin-facing surface of the absorbent main body 10, a pair of leak-proof cuffs 6, 6 are provided, which are composed of a liquid-resistant or water-repellent and breathable cuff-forming sheet 60 and a cuff-forming elastic member 61. In this embodiment, each of the pair of leak-proof cuffs 6, 6 is folded in half along the longitudinal direction, and the cuff-forming elastic member 61 is arranged in an extended state between two opposing cuff-forming sheets 60, and the opposing sheets are joined to form them.

[0023] The leak - proof cuff 6 shown in Fig. 3 has a base end portion 65 fixed to the absorbent main body 10 and a free end portion 67 to which the elastic member 61 is fixed. In the base end portion 65 of the present embodiment, the cuff - forming sheet 60 is joined and fixed between the surface sheet 2 and the back - surface sheet 3 of the absorbent main body 10. The free end portion 67 of the present embodiment is formed by folding back a single cuff - forming sheet 60, and one or a plurality of cuff - forming elastic members 61 are arranged in an extended state in the longitudinal direction X between the pair of folded - back cuff - forming sheets 60. When the elastic member 61 contracts during the wearing of the diaper 1, the leak - proof cuff 6 stands up at least in the crotch portion C.

[0024] As shown in Fig. 2, the outer wrapper 5 forms the outer shape of the diaper 1 in a deployed and extended state, and the peripheral edge of the outer wrapper 5 forms the contour lines of the abdominal side portion A, the crotch portion C, and the back side portion B, respectively. As shown in Fig. 2, in the crotch portion C of the outer wrapper 5, both side edges along the longitudinal direction X of the outer wrapper 5 are curved in an arc shape convex toward the center in the width direction Y, and the central region in the longitudinal direction X is constricted inward in the width direction Y.

[0025] As shown in Fig. 2, the outer wrapper 5 has an outer - layer non - woven fabric 51 that forms the non - skin - facing surface, which is the outer surface of the diaper 1, and an inner - layer non - woven fabric 52 that is arranged on the skin - facing surface side of the outer - layer non - woven fabric 51 and forms the skin - facing surface of the outer wrapper 5. The side panel 15 also has the outer - layer non - woven fabric 51 and the inner - layer non - woven fabric 52 in the same configuration as the outer wrapper 5 described above and is arranged continuously in the width direction Y.

[0026] In the present embodiment, the side panel 15 and the exterior body 5 including the same are configured such that the coefficient of friction of the outer nonwoven fabric 51 and the coefficient of friction of the inner nonwoven fabric 52 are different from each other. As the coefficients of friction of the outer nonwoven fabric 51 and the inner nonwoven fabric 52 being different from each other, for example, at least one of the mean deviation of the coefficient of friction MMD, the mean coefficient of friction MIU, the static coefficient of friction, and the dynamic coefficient of friction as described later can be mentioned, but it is not limited thereto. In order to configure the coefficient of friction of the outer nonwoven fabric 51 and the coefficient of friction of the inner nonwoven fabric 52 to be different from each other, for example, nonwoven fabrics with different manufacturing methods can be used, a lubricant can be applied or added to the nonwoven fabric, or a nonwoven fabric containing crimped fibers or the like as described later can be used.

[0027] The exterior body 5 shown in FIG. 2 preferably has a plurality of elastic members 55, 56, 57 disposed between the outer nonwoven fabric 51 and the inner nonwoven fabric 52. These elastic members are joined by a method such as an adhesive between the outer nonwoven fabric 51 and the inner nonwoven fabric 52. These elastic members 55, 56, 57 may be the same as each other or different from each other.

[0028] As shown in FIG. 2, the exterior body 5 of the present embodiment has a body circumferential elastic member 55 located outward of the absorbent body 10 in the longitudinal direction X and an inner elastic member 56 located inward of both ends of the absorbent body 10 in the longitudinal direction X. The elastic members 56, 57 disposed at positions overlapping the absorbent body 10 in the longitudinal direction X may be arranged so as not to exhibit elastic stretchability in a region overlapping the absorbent body 10 in the thickness direction by processes such as finely dividing.

[0029] The exterior body 5 including the side panel 15 has a plurality of filamentous or strip-shaped elastic members 55, 56 arranged in an extended state in the width direction Y on each of the ventral part A and the dorsal part B, and the plurality of elastic members 55, 56 are arranged at predetermined intervals in the longitudinal direction X. All of these elastic members 55, 56 are arranged between the outer nonwoven fabric 51 and the inner nonwoven fabric 52. By arranging each elastic member 55, 56, the exterior body 5 including the side panel 15 is configured to be stretchable in the width direction Y. Further, in the natural state or the worn state of the diaper, an annular waist gather (fold) that is substantially continuous over the entire circumference is formed in the region including the peripheral edge (waist opening edge) WE of the waist opening. It is preferable that this fold extends in the longitudinal direction and a plurality of them are arranged along the width direction Y, which is the extending direction of the elastic members 55, 56.

[0030] As shown in FIGS. 1 and 2, in the side panel 15 which is a part of the exterior body 5, one or a plurality of filamentous or strip-shaped elastic members 57 are arranged in an extended state at the leg edge LS that forms the opening edge of each leg opening LH. The elastic member 57 is arranged outward in the width direction of the absorbent body 10 and is arranged at a position around the wearer's leg in the worn state of the diaper 1. That is, the elastic member 57 is a leg elastic member for forming a leg gather. The elastic member 57 is arranged between the outer nonwoven fabric 51 and the inner nonwoven fabric 52. By arranging the elastic member 57, an annular leg gather that is substantially continuous over the entire circumference is formed at the opening edge of each leg opening LH. The elastic member 57 may be the same as or different from each of the above-described elastic members 55, 56.

[0031] As shown in FIG. 2, the elastic member 57 in the present embodiment is arranged to be curved corresponding to a shape in which both side edges along the longitudinal direction X of the exterior body 5 are constricted inward in the width direction Y toward the central region in the longitudinal direction X. Both end regions of the elastic member 57 are arranged to extend in the width direction Y, and both end portions 57a, 57a of the elastic member 57 are arranged in the side seal portion S and the region in the vicinity thereof in the side panel 15, respectively. Alternatively, the elastic member 57 may be arranged to extend along the longitudinal direction X.

[0032] As shown in FIG. 2, in each of the ventral side portion A and the dorsal side portion B of the outer package 5, at least the outer layer nonwoven fabric 51 is folded back along the waist opening end WE toward the skin-facing surface side, whereby the folded-back portion 51a is continuously formed. The folded-back portion 51a at the position where the absorbent main body 10 exists has its end region joined to the skin-facing surface of the absorbent main body 10 at the position where the absorbent main body 10 exists.

[0033]

[0032] On the other hand, as shown in FIG. 4, at the position where the absorbent main body 10 does not exist, that is, at the folded-back portion 51a located on the side panel 15, at its end region, the non-skin-facing surface of the outer layer nonwoven fabric 51 constituting the folded-back portion 51a and the skin-facing surface of the inner layer nonwoven fabric 52 are joined by the joining portion 53. The joining portion 53 is preferably formed inward (toward the crotch portion C side) of both side edges in the longitudinal direction X of the absorbent main body 10. In addition to the side panel 15, the joining portion 53 may be formed continuously or discontinuously also at the position where the absorbent main body 10 overlaps in the outer package 5. The folded-back portion 51a in the present embodiment is in a mode where its end is not joined, but instead, it may be joined by the joining portion 53 so as to include the end of the folded-back portion 51a. Since the outer layer nonwoven fabric 51 is folded back along the waist opening end WE toward the skin-facing surface side, the non-skin-facing surface of the outer layer nonwoven fabric 51 at a position other than the folded-back portion 51a constitutes the outer surface of the diaper 1, and the continuous surface of this surface and the outer layer nonwoven fabric 51 located at the folded-back portion 51a is directed toward the wearer's skin side to constitute the skin-facing surface.

[0034]

[0033] Focusing on the side panel 15, each side panel 15 includes a first region E1 located on the waist opening end WE side, which is outward in the longitudinal direction X from the joining portion 53, with reference to the inner end in the longitudinal direction X, which is the formation position of the joining portion 53. The skin-facing surface in the first region E1 is constituted by the folded-back portion 51a, that is, the outer layer nonwoven fabric 51. The first region E1 is preferably formed continuously in the width direction Y on the skin-facing surface of each side panel 15 and in addition, on the skin-facing surface of the outer package 5.

[0035] In addition to this, each side panel 15 includes a second region E2 located on the thigh portion C side, which is inward in the longitudinal direction X from the joint portion 53. The second region E2 is located inward in the longitudinal direction from the first region E1, and the first region E1 and the second region E2 are adjacent to each other. The skin-facing surface in the second region E2 is constituted by the inner non-woven fabric 52. That is, the skin-facing surface of the second region E2 has a portion where the inner non-woven fabric 52 is exposed. Both the skin-facing surface in the first region E1 and the skin-facing surface of the second region E2 preferably constitute surfaces that come into contact with the skin of the wearer. On the other hand, both the non-skin-facing surface of the first region E1 and the non-skin-facing surface of the second region E2 are constituted by the outer non-woven fabric 51 in the exterior body 5. Since the skin-facing surface of the side panel 15 has the above-described configuration, in combination with the difference in the friction coefficients of the above-described outer non-woven fabric 51 and inner non-woven fabric 52, the diaper 1 can be easily pulled up to an appropriate position.

[0036] As described above, in the natural state, it is preferable that the side panel 15 has folds formed therein. These folds preferably extend in the longitudinal direction X and are arranged in a plurality along the width direction Y, and are also preferably formed at least on the skin-facing surface of the side panel 15. In addition to this, it is preferable that the depth of the folds in the first region E1 is greater than the depth of the folds in the second region E2. It is preferable that this relationship of the fold depth is also satisfied in the worn state of the diaper. With such a configuration, not only the difference in the friction coefficients of the outer non-woven fabric 51 and the inner non-woven fabric 52, but also the difference in friction caused by the difference in the depth of the folds can reduce the excessive pulling up of the diaper 1 and prevent leakage of liquids such as urine.

[0037] In order to make the depths of the folds in the respective regions E1 and E2 different, for example, when joining the outer nonwoven fabric 51 and the inner nonwoven fabric 52 with an adhesive or the like, the application pattern of the adhesive may be made different between the first region E1 and the second region E2, or the elongation ratios of the respective elastic members 55, 56, and 57 may be arranged to be different. Specifically, as the application pattern of the adhesive, at the planned formation position of the first region E1, the adhesive is applied in a discontinuous pattern having non-coated portions of the adhesive in a spiral shape, a dotted shape, a stripe shape, etc., and at the planned formation position of the second region E2, the adhesive is continuously applied over the entire surface of each nonwoven fabric 51 and 52. Also, those with a high elongation ratio of the elastic member may be used in the first region E1, and those with a low elongation ratio of the elastic member may be used in the second region E2.

[0038] Also, the depths D1 and D2 of the folds in the respective regions E1 and E2 can be regarded as being the same as the thicknesses of the respective regions E1 and E2 in their natural states. The depth of the fold can be, for example, a measured value using a non-contact laser displacement meter (laser head LK-2100 manufactured by KEYENCE Corporation, displacement meter RV 3-55 R). The pressure during thickness measurement is 0.5 g / cm 2 shall be.

[0039] The ratio (D1 / D2) of the depth D1 of the fold in the first region E1 to the depth D2 of the fold in the second region E2 is preferably 1.1 or more, more preferably 2.0 or more, still more preferably 4.5 or more, and realistically 15 or less. The depth D1 of the fold in the first region E1 is preferably 3.5 mm or more, more preferably 5.0 mm or more, still more preferably 7.0 mm or more, and preferably 15 mm or less, more preferably 12 mm or less, still more preferably 10 mm or less. The depth D2 of the fold in the second region E2 is preferably 0.5 mm or more, more preferably 1 mm or more, still more preferably 1.5 mm or more, and preferably 3.5 mm or less, more preferably 2.5 mm or less, still more preferably 1.5 mm or less.

[0040] The diaper 1 having the above configuration uses two types of non-woven fabrics having different coefficients of friction as the constituent materials of the outer body 5, and constitutes a plurality of regions different from friction at the portion in contact with the wearer's skin in the side panel, whereby the diaper 1 can be worn at an appropriate position. Specifically, in the case of a pant-type disposable diaper, it is common to hold the outer body and pull it upward toward the wearer. However, when wearing the diaper, the diaper 1 may be worn in a state where it is pulled up excessively. As a result, the liquid excretion part such as the urethra may be in close contact with the skin-facing surface of the diaper, and sufficient space necessary for liquid absorption may not be secured between the diaper and the wearer.

[0041] Regarding this point, according to the present invention, by forming the skin-facing surface of the first region located on the waist opening end side with an outer layer non-woven fabric having less friction, it is possible to easily pull up the diaper. Further, by forming the skin-facing surface of the second region on the crotch side of the first region with an inner layer non-woven fabric having a large friction, an appropriate frictional force is generated between the diaper and the wearer's skin, and excessive pulling up of the diaper 1 can be prevented. Then, the liquid excretion part such as the urethra does not come into close contact with the skin-facing surface of the diaper, and a space necessary for liquid absorption can be secured between the diaper and the wearer. In addition to this, by making the depth of the fold formed in the second region smaller than the depth of the fold formed in the first region, the contact area between the non-woven fabric and the wearer's skin on the skin-facing surface of the second region is increased, and the frictional force generated between the non-woven fabric and the wearer's skin is increased. Also in this regard, excessive pulling up of the diaper 1 can be prevented, and a space necessary for liquid absorption can be secured between the diaper and the wearer. As a result, the absorption performance of the excreted liquid can be enhanced, and leakage of the liquid to the outside of the diaper can be prevented.

[0042] As an embodiment of the configuration regarding the difference in the coefficient of friction between the outer nonwoven fabric 51 and the inner nonwoven fabric 52, it is preferable that the average coefficient of friction MIU of the inner nonwoven fabric 52 is higher than the average coefficient of friction MIU of the outer nonwoven fabric 51. With such a configuration, excessive pulling up of the diaper 1 can be prevented, and it is possible to effectively and easily secure the space necessary for liquid absorption between the diaper and the wearer. In order to configure the coefficient of friction of the outer nonwoven fabric 51 and the coefficient of friction of the inner nonwoven fabric 52 to be different from each other, for example, nonwoven fabrics with different manufacturing methods such as air-through nonwoven fabric, spunbond nonwoven fabric, meltblown nonwoven fabric, and spunlace nonwoven fabric are used, or a lubricant or softener is applied or added to the nonwoven fabric, or the composition of the constituent resin of the nonwoven fabric is changed, or the fiber diameter, fiber fusion area, and fusion rate are controlled, or a nonwoven fabric containing crimped fibers or the like is used.

[0043] The average coefficient of friction MIU of the nonwoven fabric can be measured by the following method. First, the nonwoven fabrics to be measured, such as the outer nonwoven fabric 51 and the inner nonwoven fabric 52, are taken out from the diaper respectively. When the constituent members of the diaper are fixed to other constituent members by an adhesive, fusion, etc. at the time of taking out, after blowing cold air of a cold spray onto the fixed part to peel off other constituent members, the adhesive adhering to the constituent member to be measured is removed by dissolving it using an organic solvent. This operation is common to all measurements in this specification. Next, artificial leather (manufactured by Idemitsu Techno Fibre Co., Ltd., Supplier Ray PBZ13001) is attached to the contactor in the KES-FB4 surface tester (manufactured by Kato Tech Co., Ltd.). The above-mentioned artificial leather is a pseudo-skin assuming the skin of the wearer and is common in the measurement method in this specification. Then, one surface of the nonwoven fabric to be measured and the surface of the artificial leather are brought into contact, and under the state where a load of 0.23 kPa is applied, the contactor with the artificial leather attached is moved horizontally at a constant speed of 0.1 cm / sec for 3 cm. This measurement is performed at three different positions, and the arithmetic mean value is taken as the average coefficient of friction MIU. The lower the average coefficient of friction MIU, the less the friction and the easier it is to slide.

[0044] The average coefficient of friction MIU of the outer nonwoven fabric 51 is preferably 0.05 or more, more preferably 0.1 or more, still more preferably 0.15 or more, and preferably 1.5 or less, more preferably 1.0 or less, still more preferably 0.5 or less. The average coefficient of friction MIU of the inner nonwoven fabric 52 is preferably 0.1 or more, more preferably 0.2 or more, still more preferably 0.3 or more, and preferably 1.6 or less, more preferably 1.1 or less, still more preferably 0.8 or less, provided that it is higher than the average coefficient of friction MIU of the outer nonwoven fabric 51.

[0045] Furthermore, the difference in the average coefficient of friction MIU obtained by subtracting the average coefficient of friction MIU of the inner nonwoven fabric 52 from the average coefficient of friction MIU of the outer nonwoven fabric 51 is preferably 0.01 or more, more preferably 0.05 or more, still more preferably 0.10 or more, and preferably 1.0 or less, more preferably 0.80 or less, still more preferably 0.50 or less. The above-mentioned difference in the average coefficient of friction MIU is provided that the average coefficient of friction MIU of the outer nonwoven fabric 51 is higher than the average coefficient of friction MIU of the inner nonwoven fabric 52.

[0046] As another embodiment of the configuration regarding the difference in the coefficient of friction between the outer nonwoven fabric 51 and the inner nonwoven fabric 52, the static coefficient of friction between the outer nonwoven fabric 51 constituting the folded-back portion 51a, which is the skin-facing surface of the first region E1, and the above-mentioned artificial leather surface (i.e., the pseudo-skin surface assuming the wearer's skin) is preferably greater than the static coefficient of friction between the inner nonwoven fabric 52 constituting the skin-facing surface of the second region E2 and the above-mentioned artificial leather surface. A large static coefficient of friction means a large frictional force in the stationary state between the diaper 1 and the wearer's skin in the worn state of the diaper. Therefore, by having such a configuration, it is possible to prevent the diaper from shifting after wearing at the waist opening end WE and its vicinity, and to maintain the worn state at an appropriate position even after wearing the diaper 1, and to secure a space required for liquid absorption between the diaper and the wearer. As a result, while further improving the fit of the diaper, the liquid leakage prevention performance is further improved. Such a configuration can be achieved, for example, by using non-woven fabrics with different manufacturing methods such as air-through non-woven fabrics, spunbond non-woven fabrics, meltblown non-woven fabrics, and spunlace non-woven fabrics, applying or adding lubricants and softeners to the non-woven fabrics, changing the composition of the constituent resin of the non-woven fabrics, controlling the fiber diameter, fiber fusion area, and fusion rate, or using non-woven fabrics containing crimped fibers and the like.

[0047] The coefficient of static friction can be measured, for example, by the following method. First, attach artificial leather to the contactor in the KES-FB4 surface tester. Next, bring one surface of the non-woven fabric to be measured into contact with the surface of the artificial leather, and with a load of 0.23 kPa applied, move the contactor with the attached artificial leather horizontally at a constant speed of 0.1 cm / sec for 3 cm to obtain a graph showing the relationship between the moving distance and the mean coefficient of friction MIU. Then, read the maximum value of the mean coefficient of friction MIU in that graph. Measure this at three different positions, and take the arithmetic mean value as the coefficient of static friction.

[0048] The coefficient of static friction of the outer non-woven fabric 51 is preferably 0.03 or more, more preferably 0.15 or more, preferably 0.50 or less, and more preferably 0.30 or less. The coefficient of static friction of the inner non-woven fabric 52 is preferably 0.05 or more, more preferably 0.20 or more, preferably 1.0 or less, and more preferably 0.70 or less, on the condition that it is lower than the coefficient of static friction of the outer non-woven fabric 51.

[0049] As yet another embodiment of the configuration regarding the difference in the coefficient of friction between the outer nonwoven fabric 51 and the inner nonwoven fabric 52, it is preferable that the coefficient of kinetic friction between the inner nonwoven fabric 52 constituting the skin-facing surface of the second region E2 and the surface of the artificial leather described above (i.e., the pseudo-skin surface assuming the skin of the wearer) is greater than the coefficient of kinetic friction between the outer nonwoven fabric 51 constituting the folded-back portion that is the skin-facing surface of the first region E1 and the surface of the artificial leather described above. A large coefficient of kinetic friction means that the frictional force between the diaper 1 and the skin of the wearer generated when pulling up the diaper is large. Therefore, by having such a configuration, when the diaper 1 is worn, it is easy to slide in the first region E1, and the handling performance such as pulling up during diaper wearing can be improved. In addition to this, since an appropriate force that resists the pulling force of the diaper can be expressed in the second region E2, excessive pulling of the diaper 1 can be prevented, and sufficient space required for liquid absorption can be secured between the diaper and the wearer. As a result, the absorption performance of the excreted liquid can be enhanced, and liquid leakage to the outside of the diaper can be further prevented. Such a configuration can be achieved, for example, by using members such as air-through nonwoven fabric or spunbond nonwoven fabric as the outer nonwoven fabric 51, or by applying a softening agent, reducing the fiber fineness, crimping the fibers, controlling the fiber orientation in the longitudinal direction of the diaper, or increasing the fused area of the fibers, and using members such as spunbond nonwoven fabric or meltblown nonwoven fabric as the inner nonwoven fabric 52, or by increasing the fiber fineness, controlling the fiber orientation in the width direction of the diaper, or applying a treatment to increase the fused area of the fibers.

[0050] The coefficient of kinetic friction is taken as the value of the coefficient of mean kinetic friction MIU when it converges after exceeding the maximum point of the coefficient of mean kinetic friction MIU closest to the measurement start position from the graph showing the relationship between the moving distance and the coefficient of mean kinetic friction MIU obtained by the measurement of the coefficient of static friction described above.

[0051] The coefficient of kinetic friction of the outer nonwoven fabric 51 is preferably 0.02 or more, more preferably 0.15 or more, preferably 0.75 or less, and more preferably 0.45 or less, on the condition that it is lower than the coefficient of static friction of the nonwoven fabric. The coefficient of kinetic friction of the inner nonwoven fabric 52 is preferably 0.04 or more, more preferably 0.18 or more, and preferably 0.80 or less, more preferably 0.55 or less, on the condition that it is higher than the coefficient of kinetic friction of the outer nonwoven fabric 51.

[0052] Regarding the nonwoven fabric constituting the side panel 15, the preferable physical properties of the average coefficient of friction MIU, the coefficient of static friction, and the coefficient of kinetic friction described above may satisfy only one of them, may satisfy any two of them, or may satisfy all of them.

[0053] Specific methods for satisfying at least one of the preferable physical properties of the average coefficient of friction MIU, the coefficient of static friction, and the coefficient of kinetic friction described above include, for example, the following forms. The forms described below may be adopted alone or in combination of a plurality. In one embodiment, as the constituent resins of the nonwoven fabrics 51 and 52, a resin composed of a polymer of a single monomer and a copolymer resin are each included, and the content of the copolymer component in the constituent fibers of the outer nonwoven fabric 51 is made less than the content of the copolymer component in the constituent fibers of the inner nonwoven fabric 52. In this case, it is also preferable that the copolymer component has a structure including monomer units having a lower molecular weight than the monomer units of the polymer of the single monomer. Specifically, polypropylene and an ethylene-propylene copolymer can be used as the constituent resins of the fibers. By adopting such a structure, the outer nonwoven fabric 51, which is a nonwoven fabric with a reduced copolymer component, has a relatively hard structure, and it is easy to lower each coefficient of friction.

[0054] As another embodiment configured to have different coefficients of friction, there is a configuration in which the amount of softening agent or lubricant applied to the outer nonwoven fabric 51 is made larger than the amount of softening agent or lubricant applied to the inner nonwoven fabric 52. As at least one of the softening agent and the lubricant, fatty acid amides such as stearic acid amide, oleic acid amide, and erucic acid amide can be used. The addition amounts of the softening agent and the lubricant are each independently preferably 0.05% by mass or more and preferably 1% by mass or less on the condition that the outer nonwoven fabric 51 > the inner nonwoven fabric 52. Thereby, it is easy to make each coefficient of friction of the outer nonwoven fabric 51 lower than that of the inner nonwoven fabric 52.

[0055] As yet another embodiment configured to have different coefficients of friction, there is a form in which the fiber diameter of the outer nonwoven fabric 51 is made thinner than the fiber diameter of the inner nonwoven fabric 52. Specifically, on the condition that the average fiber diameter of the outer nonwoven fabric 51 is smaller than the average fiber diameter of the inner nonwoven fabric 52, the fiber diameters of the nonwoven fabrics are each independently preferably 5 μm or more, more preferably 10 μm or more, from the viewpoint of facilitating the configuration of reducing friction. Also, from the viewpoint of preventing sagging of the nonwoven fabric, on the condition that the average fiber diameter of the outer nonwoven fabric 51 is smaller than the average fiber diameter of the inner nonwoven fabric 52, the fiber diameters of the nonwoven fabrics are each independently preferably 25 μm or less, more preferably 15 μm or less. The fiber diameter is the arithmetic mean value when measuring 10 fibers using a microscope or an electron microscope. Thereby, it is easy to make each coefficient of friction of the outer nonwoven fabric 51 lower than that of the inner nonwoven fabric 52.

[0056] As yet another embodiment configured to have different coefficients of friction, there is a form in which the area ratio of the emboss formed on the outer nonwoven fabric 51 is made larger than the area ratio of the emboss formed on the inner nonwoven fabric 52. Specifically, on the condition that the emboss area ratio of the outer nonwoven fabric 51 > the emboss area ratio of the inner nonwoven fabric 52, the emboss area ratios of the nonwoven fabrics are each independently preferably 12% or less, more preferably 10% or less. Thereby, it is easy to make each coefficient of friction of the outer nonwoven fabric 51 lower than that of the inner nonwoven fabric 52.

[0057] As yet another embodiment configured to have different friction coefficients, there is a form in which the hydrophilicity of the outer nonwoven fabric 51 is lower than that of the inner nonwoven fabric 52. That is, it is preferable that the relationship of "contact angle of the outer nonwoven fabric 51 < contact angle of the inner nonwoven fabric 52" holds. Specifically, on the condition that the contact angle of the outer nonwoven fabric 51 < the contact angle of the inner nonwoven fabric 52, the contact angle of each nonwoven fabric is, independently, preferably 90° or more, more preferably 100° or more, and still more preferably 120° or more. The adjustment of the hydrophilicity includes, for example, changing the type and content of the resin contained in each nonwoven fabric, or subjecting the constituent fibers or nonwoven fabric to a hydrophilic treatment or a hydrophobic treatment. Thereby, it is easy to make each friction coefficient of the outer nonwoven fabric 51 lower than that of the inner nonwoven fabric 52.

[0058] As yet another embodiment configured to have different friction coefficients, there is a method in which crimped fibers described later are used as the constituent fibers of the outer nonwoven fabric 51 and crimped fibers are not used as the constituent fibers of the inner nonwoven fabric 52. Thereby, it is easy to make each friction coefficient of the outer nonwoven fabric 51 lower than that of the inner nonwoven fabric 52.

[0059] When the side panel 15 includes the elastic member 57, it is preferable that the diaper 1 has different friction coefficients between the waist opening end WE side in the side panel 15 and the crotch part C side of the side panel 15 with reference to the position of the end portion 57a of the elastic member 57. Specifically, the position of the end portion 57a of the elastic member 57 in the longitudinal direction X is preferably the boundary between the first region E1 and the second region E2 in FIG. 2, or the boundary between the first region E1 and the second region E2 is outside the longitudinal direction X with respect to the position of the end portion 57a in the longitudinal direction X. When a plurality of elastic members 57 are arranged or when they are precut, the reference position of the end portion 57a is based on the end portion of the elastic member 57 located on the outermost side in the longitudinal direction X. With such a configuration, a regional difference in the magnitude of friction occurs at the waist opening, and it is possible to easily pull up the diaper immediately after pulling it up, and to hold it at a more optimal wearing position without pulling up the wearing position too much. Such a configuration can be achieved by appropriately adjusting, for example, the folding length along the longitudinal direction X of the folding portion 51a, the position of the joint portion 53, or the arrangement position of the elastic member 57.

[0060] As described above, when the exterior body 5 including the side panel 15 is provided with a plurality of elastic members 55 and 56 and is configured to be stretchable in the width direction Y, it is preferable that the first region E1 includes a plurality of stretchable regions. Specifically, as shown in FIG. 2, the first region E1 in each of the ventral side portion A and the dorsal side portion B preferably has a first stretchable region 91 located closer to the waist opening end WE when viewed along the longitudinal direction, and a second stretchable region 92 adjacent to the first stretchable region 91 and located on the crotch portion C side of the first stretchable region 91. It is also preferable that both the first stretchable region 91 and the second stretchable region 92 stretch in the width direction Y. Further, it is preferable that the stretch stress in the width direction Y of the first stretchable region 91 is different from the stretch stress in the width direction Y of the second stretchable region 92. With such a configuration, appropriate stretch stress can be generated according to the uneven shape of the wearer's body shape in the waist portion, and the fit of the diaper is further improved.

[0061] The first stretchable region 91 in the present embodiment has a plurality of torso elastic members 55, and the second stretchable region 92 has an inner elastic member 56. Further, in the present embodiment, the first stretchable region 91 is located between the waist opening end WE and the end 10a of the absorbent body 10 when viewed along the longitudinal direction X of the first region E1, and the second stretchable region 92 is located on the crotch portion C side of the end 10a of the absorbent body 10 in the first region E1.

[0062] In addition to this, as shown in FIG. 2, when the second region E2 is an inner stretchable region 93 configured to be stretchable in the width direction Y by providing at least a plurality of elastic members 57, it is preferable that the stretch stresses in the width direction Y of the stretchable regions 91 and 92 in the first region E1 and the stretch stress of the inner stretchable region 93 in the second region E2 have a predetermined relationship.

[0063] Specifically, the expansion / contraction stress Fa in the width direction Y of the first expansion / contraction region 91 is preferably smaller than the expansion / contraction stress Fb in the width direction Y of the second expansion / contraction region 92. Also, the expansion / contraction stress Fc in the width direction Y of the inner expansion / contraction region 93 is preferably a value intermediate between the above-described expansion / contraction stress Fa and the expansion / contraction stress Fb. That is, it is preferable that the expansion / contraction stress increases in the order of Fa < Fc < Fb. With such a configuration, appropriate expansion / contraction stress can be exhibited according to the uneven shape in the waist part and the lower abdomen, the fit of the diaper can be improved, and leakage of liquid in the front-rear direction can be prevented.

[0064] The expansion / contraction stress can be measured by the following method. First, the side seal part S of the diaper 1 is peeled off, the diaper 1 is put in a deployed state, and in that state, the measurement target part of the expansion / contraction stress in the side panel 15 is cut out as a measurement sample having a rectangular shape in plan view. Specifically, in the longitudinal direction X of the first region E1, from a position 5 mm away from the waist opening WH side with respect to the elastic member 55 located closest to the waist opening WH side, to a position where there are no elastic members between the elastic member 55 located closest to the crotch side in the longitudinal direction X and the elastic member 56 located closest to the waist opening WH side, the region up to the position where there are no elastic members is cut out, and this is used as the measurement sample of the first expansion / contraction region 91. When a sample of this region cannot be cut out, the measurement sample of the first expansion / contraction region 91 is cut out from the waist opening end WE. Also, in the longitudinal direction X of the first region E1, one end of the sample is a position where there are no elastic members between the elastic member 55 located closest to the crotch side in the longitudinal direction X and the elastic member 56 located closest to the waist opening WH side. Also, in the longitudinal direction X of the first region E1, the other end of the sample is a position between the part that overlaps with the outer layer folded-back end portion in the thickness direction in the deployed state of the diaper and the elastic member 56 located closest to the crotch side. The region from one end to the other end of the above-described sample is cut out, and this is used as the measurement sample of the second expansion / contraction region 92. When a sample of this region cannot be cut out, the measurement sample of the second expansion / contraction region 92 is cut out from the same position as the outer layer folded-back end portion in the thickness direction. Furthermore, in the longitudinal direction X of the second region E2, a region between a portion that overlaps with the outer layer folded-back end portion in the thickness direction and a position up to the crotch-side end portion of the side seal portion is cut out, and this is used as a measurement sample for the inner expansion / contraction region 93.

[0065] Regarding each cut-out measurement sample, measure the length in the direction corresponding to the longitudinal direction (X direction) of the diaper 1 and the length in the direction corresponding to the width direction (Y direction), that is, the total length between the side seal portions S, S. Next, fix the measurement sample between the chucks of a tensile testing machine (for example, "RTA-100" manufactured by Orientec Co., Ltd., etc.) so that the width direction (Y direction) of the measurement sample coincides with the tensile direction. The distance between the chucks is set to 100 mm. Then, fix the measurement sample between the chucks, and at a speed of 300 mm / min, increase the distance between the chucks to a length at which the elongation of the measurement sample becomes 80, and then measure the tensile load (N) when the elongation of the measurement sample is decreased to a length at which the elongation becomes 71, and this is taken as the stress (N) of the measurement sample.

[0066] The elongation of the measurement sample is the ratio of the length in the width direction of the measurement sample extended in the width direction to the total length in the width direction (Y direction) between the side seal portions S, S when the total length in the width direction between the side seal portions S, S is set to 100. That is, the length in the width direction of the measurement sample with an elongation of 100 is equal to the total length in the width direction (Y direction) between the side seal portions S, S. For example, when the total length is 350 mm, the length in the width direction of the measurement sample with an elongation of 80 is 280 mm, and the length in the width direction of the measurement sample with an elongation of 71 is 250 mm. Then, a value obtained by dividing the obtained stress (N) by the length in the longitudinal direction (X direction) measured in advance is taken as the expansion / contraction stress (N / mm) of the measurement sample.

[0067] The expansion / contraction stress Fa in the width direction Y of the first expansion / contraction region 91 is preferably 0.8 or more, more preferably 1.0 or more, preferably 7.0 or less, and more preferably 6.0 or less. The expansion / contraction stress Fb in the width direction Y of the second expansion / contraction region 92 is preferably 0.8 or more, more preferably 1.0 or more, preferably 7.0 or less, and more preferably 6.0 or less. The expansion and contraction stress Fc in the width direction Y of the inner expansion and contraction region 93 is preferably 0.8 or more, more preferably 1.0 or more, and preferably 7.0 or less, more preferably 6.0 or less.

[0068] In order to satisfy the relationships of the above-described expansion and contraction stresses Fa, Fb, and Fc, it is preferable to satisfy at least one of the following configurations (1) to (3), for example. (1) The thicknesses of the elastic members arranged in each expansion and contraction region are in the order of the elastic member 55 arranged in the first expansion and contraction region 91 < the elastic member 57 arranged in the inner expansion and contraction region 93 < the elastic member 56 arranged in the second expansion and contraction region 92, being thickest. (2) The elongation ratios of the elastic members arranged in each expansion and contraction region are in the order of the elastic member 55 arranged in the first expansion and contraction region 91 < the elastic member 57 arranged in the inner expansion and contraction region 93 < the elastic member 56 arranged in the second expansion and contraction region 92, being largest. (3) The intervals between adjacent elastic members arranged in each expansion and contraction region are in the order of the first expansion and contraction region 91 > the inner expansion and contraction region 93 > the second expansion and contraction region 92, being smallest.

[0069] The first expansion and contraction region 91 and the second expansion and contraction region 92 may be specified by the following method based on the above-described configurations (1) to (3). First, along the longitudinal direction X, sequentially measure the thickness of the elastic member of the configuration (1), the elongation ratio of the elastic member of the configuration (2), or the interval between the elastic members of the configuration (3) from the waist opening end WE toward the crotch part C side. Regarding the above configuration (1), in the first region E1, when the thickness of the elastic member f2 to be measured becomes greater than the thickness of the immediately preceding measured elastic member f1, the region from the elastic member closest to the waist opening end WE to the immediately preceding measured elastic member f1 is specified as the first stretchable region 91. Further, the region from the elastic member f2 to be measured to the elastic member located closest to the crotch part C side in the first region E1 is specified as the second stretchable region 92. The "thickness of the elastic member" refers to the thickness of the elastic member in the non-stretched state, and when the elastic member is in the form of a thread, it is represented by the diameter of its cross-section. When the elastic member is composed of a bundle of a plurality of elastic fibers, a sample obtained by cutting out the elastic member from the outer package body at a certain length (e.g., 100 mm) may be used, and the weight per unit length may be represented as the "thickness (fineness) of the elastic member" from the length and mass of the sample.

[0070] Regarding the above configuration (2), in the first region E1, when the elongation ratio of the elastic member f2 to be measured becomes higher than the elongation ratio of the immediately preceding measured elastic member f1, the region from the elastic member closest to the waist opening end WE to the immediately preceding measured elastic member f1 is specified as the first stretchable region 91, and in the first region E1, the region from the elastic member f2 to be measured to the elastic member located closest to the crotch part C side is specified as the second stretchable region 92.

[0071] The measurement of the elongation ratio of the elastic member is shown below. First, the diaper is brought into a state where it is maximally stretched in the stretching direction of the elastic member, and two marks are made on the elastic member from above the outer layer nonwoven fabric at regular intervals L0 (e.g., 100 mm) in the stretching direction using an oil-based pen. At this time, since the ink of the oil-based pen penetrates from the outer layer nonwoven fabric, the above marks can be made on the elastic member. Next, the portion between the two marks is cut out from the elastic member in the diaper. The length L1 of the cut-out elastic member is measured in the non-stretched state. Then, the elongation ratio is obtained by the following formula [I]. Elongation ratio (%) = (L0 / L1) × 100 ··· [I]

[0072] Regarding the above configuration (3), in the first region E1, an elastic member is specified in which the interval between adjacent elastic members in the longitudinal direction X is smaller than the interval between adjacent elastic members on the waist opening end WE side, and the region from the specified elastic member to the elastic member located on the most crotch part C side in the first region E1 is specified as the second stretchable region 92. Further, the region from the elastic member adjacent to the waist opening end WE side of the specified elastic member to the elastic member located on the most waist opening end WE side is specified as the first stretchable region 91.

[0073] Specific methods for satisfying the relationship between the above-described first region E1 and second region E2 include, for example, the following forms. The forms described below may be employed alone or in combination of a plurality. By adopting the following configuration, a fold shape that continuously extends in one direction is likely to be formed in the first region E1, and a discontinuous fold shape is likely to be formed in the second region E2. As a result, the depth of the fold formed in the second region becomes smaller than the depth of the fold formed in the first region.

[0074] In one embodiment, in the first region E1, the elastic members 55 are arranged to extend in the width direction Y so that only the stretching stress along the width direction Y is generated, and in the second region E2, the elastic members 57 are arranged to have a portion intersecting both the longitudinal direction X and the width direction Y, so that stretching stress is expressed in both the longitudinal direction X and the width direction Y. Thereby, the depth of the fold formed in the second region can be made smaller than the depth of the fold formed in the first region.

[0075] As another embodiment for making the depth of the fold formed in the second region smaller than the depth of the fold formed in the first region, a configuration is provided in which the interval between adjacent elastic members 55 arranged in the first region E1 is made larger than the interval between adjacent elastic members 57 arranged in the second region E2.

[0076] In the second region E2, it is preferable that the pleats are formed in the waist opening and the crotch region, and there is a portion where no pleat is formed between the waist opening and the crotch region. In order to achieve such a configuration, for example, as shown in FIG. 2, the elastic member 57 may be curved and arranged to include both a portion arranged to extend in the longitudinal direction X or the width direction Y and a portion arranged to intersect the longitudinal direction X and the width direction Y.

[0077] As the outer nonwoven fabric 51 and the inner nonwoven fabric 52 constituting the exterior body 5, nonwoven fabrics produced by various manufacturing methods can be used. Specific examples thereof include spunbond nonwoven fabric, air-through nonwoven fabric, spunlace nonwoven fabric, heat roll nonwoven fabric, meltblown nonwoven fabric, or laminated nonwoven fabrics thereof. The outer nonwoven fabric 51 and the inner nonwoven fabric 52 may each independently have a single-layer structure or a multilayer structure. Further, the outer nonwoven fabric 51 and the inner nonwoven fabric 52 may each independently be non-elastic or may have elasticity.

[0078] From the viewpoint of efficiently satisfying the above-described relationship of the coefficient of friction and making the texture such as flexibility good, it is preferable that the outer nonwoven fabric 51 includes crimped fibers as its constituent fibers. The crimped fibers are fibers having a crimp form in a spiral shape, a zigzag shape, a U shape, or a combination thereof. Such a nonwoven fabric containing such fibers can be obtained, for example, by manufacturing a nonwoven fabric using heat-shrinkable and uncrimped composite fibers such as a core-sheath type or a side-by-side type, and then heating the nonwoven fabric to cause the fibers to exhibit crimps. Alternatively, in the manufacturing method of a spunbond nonwoven fabric, fibers having crimps generated during spinning are generated by spinning fibers in a side-by-side type, and the nonwoven fabric can be obtained by depositing these fibers.

[0079] When the outer nonwoven fabric 51 contains crimped fibers, the outer nonwoven fabric 51 preferably has a multi-layer structure including a fiber layer containing crimped fibers, and the fiber layer containing crimped fibers is preferably arranged so as to be located on the outermost surface of the outer nonwoven fabric 51. That is, it is preferable that both the outer surface of the exterior body 5 and the skin-facing surface of the folded-back portion 51a are formed by the fiber layer containing the crimped fibers of the outer nonwoven fabric 51. With such a configuration, while more efficiently satisfying the relationship of the friction coefficient described above, the touch feeling such as flexibility can be made even better. Such an outer nonwoven fabric 51 can be obtained, for example, by laminating and joining a nonwoven fabric such as a spunbond nonwoven fabric containing crimped fibers and another nonwoven fabric in a laminated state.

[0080] When the outer nonwoven fabric 51 contains crimped fibers, from the viewpoint of efficiently satisfying the relationship of the friction coefficient described above and making the touch feeling such as flexibility good, the content of the crimped fibers in the outer nonwoven fabric 51 is preferably 1.0% by mass or more, more preferably 10% by mass or more, preferably 99% by mass or less, and more preferably 80% by mass or less. The content of the crimped fibers can be measured, for example, by randomly collecting 10 regions of 1 cm from the nonwoven fabric and measuring the ratio of the number of crimped fibers to the total number of fibers with a scanning electron microscope (SEM). Crimped fibers mean fibers having a crimp number of 1 or more measured according to JIS L1015. 2 The content of the crimped fibers can be measured by randomly collecting 10 regions of 1 cm from the nonwoven fabric and measuring the ratio of the number of crimped fibers to the total number of fibers with a scanning electron microscope (SEM). Crimped fibers mean fibers having a crimp number of 1 or more measured according to JIS L1015.

[0081] From the viewpoint of improving both the touch feeling and the wearing feeling, the total areal weight of the outer nonwoven fabric 51 is preferably 12 g / m 2 or more, more preferably 15 g / m 2 or more, preferably 50 g / m 2 or less, more preferably 40 g / m 2 or less. From the same viewpoint, the total areal weight of the inner nonwoven fabric 52 is preferably 13 g / m 2 or more, more preferably 15 g / m 2 or more, preferably 50 g / m 2 or less, more preferably 40 g / m 2 or less.

[0082] In the above-described embodiments, each of the expansion / contraction regions 91, 92, 93 had elasticity by arranging a plurality of elastic members 55, 56, 57 between the outer nonwoven fabric 51 and the inner nonwoven fabric 52. However, a sheet-like elastic member may be arranged between the outer nonwoven fabric 51 and the inner nonwoven fabric 52. Further, either one or both of the outer nonwoven fabric 51 and the inner nonwoven fabric 52 may be formed of an expansion / contraction sheet that expands and contracts in the width direction Y. As such an expansion / contraction sheet, various known ones can be used. For example, the expansion / contraction sheet described in JP-A-2008-179128, the expansion / contraction sheet described in JP-A-2007-22066, and the expansion / contraction nonwoven fabric manufactured by the method for manufacturing an expansion / contraction nonwoven fabric described in JP-A-2007-22066 can also be used.

[0083] Typically, the expansion / contraction sheet is formed by joining a plurality of elastic filaments arranged to extend in one direction without intersecting each other in a substantially non-extended state over the entire length thereof to one surface of a single nonwoven fabric or between two nonwoven fabrics. When an expansion / contraction nonwoven fabric is used as the outer nonwoven fabric 51 or the inner nonwoven fabric 52, it is preferable that each elastic filament is arranged to extend along the width direction Y.

[0084] As described above, the preferred embodiments of the present invention have been described. However, the present invention is not limited to the above-described embodiments. For example, in the diaper of the above-described embodiment, the inner nonwoven fabric 52 is not folded back to the skin-facing side along the waist opening end WE. However, in addition to the outer nonwoven fabric 51, the inner nonwoven fabric 52 may be further folded back. In this case, the outer nonwoven fabric 51 extends from the edge in the longitudinal direction X of the inner nonwoven fabric 52 and is folded back to the skin-facing side of the inner nonwoven fabric 52.

[0085] In addition, in the diaper of the above-described embodiment, in the deployed and extended state, the outer wrapper 5 was continuously arranged on the ventral part A, the lower crotch part C, and the dorsal part B. However, the outer wrapper 5 may be divided into a dorsal outer wrapper arranged on the back side of the wearer and a ventral outer wrapper arranged on the ventral side, and may not be arranged on the lower crotch part C. In this case, the absorbent main body is fixed by bridging between the dorsal outer wrapper and the ventral outer wrapper.

[0086] Regarding the above-described embodiment, the following pant-type disposable diaper is further disclosed. <1> It has a longitudinal direction corresponding to the front-back direction of the wearer and a width direction orthogonal to the longitudinal direction, and has a ventral part arranged on the ventral side of the wearer, a dorsal part arranged on the back side of the wearer, and a lower crotch part located between the ventral part and the dorsal part. A pant-type disposable diaper having an absorbent main body arranged in a region from the ventral part to the dorsal part and an outer wrapper arranged on the non-skin-facing surface side of the absorbent main body. The outer wrapper includes an outer-layer nonwoven fabric forming the non-skin-facing surface of the outer wrapper and an inner-layer nonwoven fabric forming the skin-facing surface of the outer wrapper. In each of the ventral part and the dorsal part, a folded-back part is formed in which the outer-layer nonwoven fabric is folded back along the waist opening end to the skin-facing surface side. The outer wrapper includes a pair of side panels extending outward in the width direction of the absorbent main body. In the folded-back part of the side panel, at its end region, the non-skin-facing surface of the outer-layer nonwoven fabric and the skin-facing surface of the inner-layer nonwoven fabric are joined by a joining part. The skin-facing surface of the side panel has a first region formed of the folded-back part of the outer-layer nonwoven fabric and located outward in the longitudinal direction from the joining part, and a second region adjacent to the first region inward in the longitudinal direction and in which the inner-layer nonwoven fabric is exposed on the skin-facing surface. The friction coefficient of the outer-layer nonwoven fabric and the friction coefficient of the inner-layer nonwoven fabric are different from each other. In the natural state, a plurality of folds extending in the longitudinal direction are formed along the width direction on at least the skin-facing surface of the side panel. The depth of the fold in the first region is greater than the depth of the fold in the second region, a pant-type disposable diaper.

[0087] <2> The ratio of the depth of the fold in the first region to the depth of the fold in the second region is 1.1 or more, preferably 2.0 or more, more preferably 4.5 or more, and preferably 15 or less, the pant-type disposable diaper according to <1>. <3> The depth of the fold in the first region is 3.5 mm or more and 15 mm or less, preferably 5.0 mm or more and 12 mm or less, more preferably 7.0 mm or more and 10.0 mm or less, the pant-type disposable diaper according to <1> or <2>. <4> The depth of the fold in the second region is 0.5 mm or more and 3.5 mm or less, preferably 1.0 mm or more and 2.5 mm or less, more preferably 1.5 mm or more and 10.0 mm or less, the pant-type disposable diaper according to any one of <1> to <3>.

[0088] <5> The average coefficient of friction MIU of the inner nonwoven fabric is higher than the average coefficient of friction MIU of the outer nonwoven fabric, the pant-type disposable diaper according to any one of <1> to <4>. <6> The average coefficient of friction MIU of the outer nonwoven fabric is 0.05 or more and 1.5 or less, preferably 0.1 or more and 1.0 or less, more preferably 0.15 or more and 0.5 or less, the pant-type disposable diaper according to <5>. <7> The average coefficient of friction MIU of the inner nonwoven fabric is 0.1 or more and 1.6 or less, preferably 0.2 or more and 1.1 or less, more preferably 0.3 or more and 0.8 or less, the pant-type disposable diaper according to <5> or <6>. <8> The difference in the average coefficient of friction MIU obtained by subtracting the average coefficient of friction MIU of the inner nonwoven fabric from the average coefficient of friction MIU of the outer nonwoven fabric is 0.01 or more and 1.0 or less, preferably 0.05 or more and 0.80 or less, more preferably 0.10 or more and 0.50 or less. The pant-type absorbent article according to any one of <5> to <7> above.

[0089] <9> The static coefficient of friction between the nonwoven fabric constituting the skin-facing surface of the first region and the pseudo-skin surface assuming the skin of the wearer is greater than the static coefficient of friction between the nonwoven fabric constituting the skin-facing surface of the second region and the pseudo-skin surface assuming the skin of the wearer. The pant-type absorbent article according to any one of <1> to <8> above. <10> The static coefficient of friction between the nonwoven fabric constituting the skin-facing surface of the first region and the pseudo-skin surface is 0.03 or more and 0.50 or less, preferably 0.15 or more and 0.30 or less. The disposable pant-type diaper according to <9> above. <11> The static coefficient of friction between the nonwoven fabric constituting the skin-facing surface of the second region and the pseudo-skin surface is 0.05 or more and 1.0 or less, preferably 0.20 or more and 0.70 or less. The disposable pant-type diaper according to <9> or <10> above.

[0090] <12> The kinetic coefficient of friction between the nonwoven fabric constituting the skin-facing surface of the second region and the pseudo-skin surface assuming the skin of the wearer is greater than the kinetic coefficient of friction between the nonwoven fabric constituting the skin-facing surface of the first region and the pseudo-skin surface assuming the skin of the wearer. The disposable pant-type diaper according to any one of <1> to <11> above. <13> The kinetic coefficient of friction between the nonwoven fabric constituting the skin-facing surface of the first region and the pseudo-skin surface assuming the skin of the wearer is 0.02 or more and 0.75 or less, preferably 0.15 or more and 0.45 or less. The disposable pant-type diaper according to <12> above. <14> The kinetic coefficient of friction between the nonwoven fabric constituting the skin-facing surface of the second region and the pseudo-skin surface assuming the skin of the wearer is 0.04 or more and 0.80 or less, preferably 0.18 or more and 0.55 or less. The disposable pant-type diaper according to <12> or <13> above. <15> Both the nonwoven fabric constituting the skin-facing surface of the first region and the nonwoven fabric constituting the skin-facing surface of the second region each contain, in their constituent fibers, a resin composed of a polymer of a single monomer and a copolymer resin. The content of the copolymer component in the constituent fibers of the nonwoven fabric constituting the skin-facing surface of the first region is less than the content of the copolymer component in the constituent fibers of the nonwoven fabric constituting the skin-facing surface of the second region. The pant-type disposable diaper according to any one of <12> to <14>.

[0091] <16> Both the nonwoven fabric constituting the skin-facing surface of the first region and the nonwoven fabric constituting the skin-facing surface of the second region each contain at least one of a softening agent and a lubricant. The content of at least one of the softening agent and the lubricant in the nonwoven fabric constituting the skin-facing surface of the second region is greater than the content thereof in the nonwoven fabric constituting the skin-facing surface of the first region. The pant-type disposable diaper according to any one of <12> to <15>. <17> The fiber diameter of the nonwoven fabric constituting the skin-facing surface of the first region is thinner than the fiber diameter of the nonwoven fabric constituting the skin-facing surface of the second region. The pant-type disposable diaper according to any one of <12> to <16>. <18> The embossed area ratio of the nonwoven fabric constituting the skin-facing surface of the first region is larger than the embossed area ratio of the nonwoven fabric constituting the skin-facing surface of the second region. The pant-type disposable diaper according to any one of <12> to <17>. <19> The hydrophilicity of the nonwoven fabric constituting the skin-facing surface of the first region is lower than the hydrophilicity of the nonwoven fabric constituting the skin-facing surface of the second region. The pant-type disposable diaper according to any one of <12> to <18>.

[0092] <20> The side panel is provided with an elastic member at a position located around the wearer's leg in the worn state of the diaper. The side panel has different friction coefficients on the waist opening end side and the crotch side with reference to the end position of the elastic member, the disposable diaper in the form of pants according to any one of <1> to <19>. <21> The outer layer nonwoven fabric contains crimped fibers, the disposable diaper in the form of pants according to any one of <1> to <20>. <22> The outer layer nonwoven fabric has a multilayer structure including a layer containing crimped fibers, The layer is located on the outermost surface of the outer layer nonwoven fabric, the disposable diaper in the form of pants according to any one of <1> to <21>. <23> The outer package further includes a plurality of elastic members arranged between the outer layer nonwoven fabric and the inner layer nonwoven fabric, The outer package is configured to be stretchable in the width direction, When looking along the longitudinal direction of the first region, the stretching stress in the width direction in the first stretching region located closer to the waist opening end is smaller than the stretching stress in the width direction in the second stretching region located closer to the crotch, The stretching stress in the width direction in the second region is of a magnitude intermediate between the stretching stress in the first stretching region and the stretching stress in the second stretching region, the disposable diaper in the form of pants according to any one of <1> to <22>.

Explanation of reference numerals

[0093] 1 Disposable diaper in the form of pants 10 Absorbent body 15 Side panel 5 Outer package 51 Outer layer nonwoven fabric 51a Folded-back portion 52 Inner layer nonwoven fabric A Abdominal side B Back side C Crotch E1 First region E2 Second region WE Waist opening end X Longitudinal direction Y Width direction

Claims

Claim 1 It has a longitudinal direction corresponding to the front-back direction of the wearer and a width direction orthogonal to the longitudinal direction, and has a ventral part arranged on the ventral side of the wearer, a dorsal part arranged on the dorsal side of the wearer, and a crotch part located between the ventral part and the dorsal part, A pant-type disposable diaper having an absorbent body arranged in the region from the ventral part to the dorsal part and an outer wrapper arranged on the non-skin-facing surface side of the absorbent body, The outer wrapper includes an outer layer nonwoven fabric forming the non-skin-facing surface of the outer wrapper and an inner layer nonwoven fabric forming the skin-facing surface of the outer wrapper, In each of the ventral part and the dorsal part, a folded-back part is formed where the outer layer nonwoven fabric is folded back along the waist opening end toward the skin-facing surface side, The outer wrapper includes a pair of side panels extending outward in the width direction of the absorbent body, In the folded-back part of the side panel, at its end region, the non-skin-facing surface of the outer layer nonwoven fabric and the skin-facing surface of the inner layer nonwoven fabric are joined by a joining part, The skin-facing surface of the side panel has a first region formed by the folded-back part of the outer layer nonwoven fabric and located outward in the longitudinal direction from the joining part, and a second region adjacent to and inward in the longitudinal direction from the first region and where the inner layer nonwoven fabric is exposed on the skin-facing surface, The coefficient of friction of the outer layer nonwoven fabric and the coefficient of friction of the inner layer nonwoven fabric are different from each other, In a natural state, a plurality of folds extending in the longitudinal direction are formed along the width direction on at least the skin-facing surface of the side panel, The pant-type disposable diaper in which the depth of the fold in the first region is greater than the depth of the fold in the second region. Claim 2 The pant-type disposable diaper according to claim 1, wherein the average coefficient of friction MIU of the inner layer nonwoven fabric is higher than the average coefficient of friction MIU of the outer layer nonwoven fabric. Claim 3 The pant-type disposable diaper according to claim 1 or 2, wherein the static coefficient of friction between the nonwoven fabric constituting the skin-facing surface of the first region and the pseudo-skin surface assuming the skin of the wearer is greater than the static coefficient of friction between the nonwoven fabric constituting the skin-facing surface of the second region and the pseudo-skin surface assuming the skin of the wearer. Claim 4 The pant-type disposable diaper according to any one of claims 1 to 3, wherein the dynamic coefficient of friction between the nonwoven fabric constituting the skin-facing surface of the second region and the pseudo-skin surface assuming the skin of the wearer is greater than the dynamic coefficient of friction between the nonwoven fabric constituting the skin-facing surface of the first region and the pseudo-skin surface assuming the skin of the wearer. Claim 5 The side panel is provided with an elastic member at a position around the wearer's leg in the state where the diaper is worn. The side panel has different friction coefficients on the waist opening end side and the crotch side with reference to the end position of the elastic member. The pant-type disposable diaper according to any one of claims 1 to 4.

6. The outer nonwoven fabric contains crimped fibers. The pant-type disposable diaper according to any one of claims 1 to 5.

7. The outer nonwoven fabric has a multilayer structure including a layer containing crimped fibers. The layer is located on the outermost surface of the outer nonwoven fabric. The pant-type disposable diaper according to any one of claims 1 to 6.

8. The outer body further includes a plurality of elastic members disposed between the outer nonwoven fabric and the inner nonwoven fabric. The outer body is configured to be stretchable in the width direction. When viewed along the longitudinal direction of the first region, the stretching stress in the width direction in the first stretching region located closer to the waist opening end is smaller than the stretching stress in the width direction in the second stretching region located closer to the crotch. The stretching stress in the width direction in the second region is of an intermediate magnitude between the stretching stress in the first stretching region and the stretching stress in the second stretching region. The pant-type disposable diaper according to any one of claims 1 to 7.

9. The side panel is provided with an elastic member at a position around the wearer's leg in the state where the diaper is worn. The longitudinal position of the end of the elastic member is the boundary between the first region and the second region, or the boundary between the first region and the second region is longitudinally outward of the longitudinal position of the end. The pant-type disposable diaper according to any one of claims 1 to 8.

10. The joint portion is formed inward of both side edges in the longitudinal direction of the absorbent body. The pant-type disposable diaper according to any one of claims 1 to 9.

11. The outer nonwoven fabric consists of a single nonwoven fabric. The pant-type disposable diaper according to any one of claims 1 to 10.

12. The outer nonwoven fabric and the inner nonwoven fabric are joined by an adhesive, and the application pattern of the adhesive is different between the first region and the second region, or The outer package has a plurality of elastic members, and the elongation ratio of the plurality of elastic members arranged in the first region is higher than the elongation ratio of the plurality of elastic members arranged in the second region, so that the depth of the fold in the first region is larger than the depth of the fold in the second region. The disposable diaper in any one of claims 1 to 11, which is a pants type.

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