CN115484910B

CN115484910B - absorbent article

Info

Publication number: CN115484910B
Application number: CN202180031572.4A
Authority: CN
Inventors: 桑畑耕平; 富田美奈
Original assignee: Kao Corp
Current assignee: Kao Corp
Priority date: 2020-05-27
Filing date: 2021-05-27
Publication date: 2023-08-29
Anticipated expiration: 2041-05-27
Also published as: GB2610963A; DE112021002929T5; JP2021186679A; WO2021241685A1; GB202218186D0; CN115484910A

Abstract

The invention provides an absorbent article (1) comprising a skin contact sheet (10) having a concave-convex area (P). The concave-convex region (P) has a plurality of convex portions (41) each having a length in the first direction (Y) longer than a length in the second direction (X), and concave portions (31) located between the convex portions in the first direction or the second direction. The concave part (31) has a low basis weight part (32) having a lower basis weight of the fibrous material than the convex part (41). In the absorbent article (1), an elastic member (19) is arranged along a first direction (Y) at a position on the non-skin-facing surface side of the skin contact sheet (10). Preferably, in the concave-convex area (P), a plurality of low-basis weight portion rows in which a plurality of low-basis weight portions (32) are arranged along the second direction (X) are formed at intervals in the first direction (Y).

Description

Absorbent article

Technical Field

The present invention relates to an absorbent article such as a disposable diaper, a urine collection pad, an incontinence pad, and a sanitary napkin.

Background

An absorbent article such as a disposable diaper generally has a sheet that contacts the skin of the wearer. It is known that from the viewpoint of skin contact, ventilation, and the like, an absorbent article having a concave-convex shape is formed on the skin-facing surface of such a sheet.

For example, patent document 1 describes an absorbent article in which first compressed concave portions arranged in a predetermined pattern and raised portions formed by a first layer are formed in a front sheet formed by stacking a first layer and a second layer, and second compressed concave portions that do not reach a second layer are formed in the raised portions.

The present inventors have previously proposed an absorbent article in which a plurality of fusion-bonded portions and protrusions are formed in a front sheet of a laminate including a first nonwoven fabric and a second nonwoven fabric, the fusion-bonded portions being formed by fusion-bonding the first nonwoven fabric and the second nonwoven fabric to each other at peripheral portions of openings, the protrusions being formed by projecting the first nonwoven fabric in a direction away from the second nonwoven fabric at portions other than the fusion-bonded portions, the fusion-bonded portions having a plurality of projecting portions projecting toward the sub-layers, and the sub-layers being partially pressed by the projecting portions when the front sheet is pressed toward the sub-layers (patent document 2).

Further, the present inventors have previously proposed an absorbent article having an inelastic region in which an elastic member is not disposed between an elastic region in which the elastic member is disposed and an absorbent core, wherein a front sheet has a portion in which an uneven region is overlapped with the inelastic region, wherein the uneven region has protrusions disposed in a predetermined pattern, and longitudinal grooves and lateral grooves formed continuously between the protrusions, and wherein the degree of bending of the longitudinal grooves is greater than that of the lateral grooves (patent document 3).

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 2006-263296

Patent document 2: japanese patent laid-open publication No. 2018-088997

Patent document 3: japanese patent laid-open publication No. 2019-076499

Disclosure of Invention

The present invention relates to an absorbent article including a skin contact sheet having a concave-convex area, which is in contact with the skin of a wearer in a worn state, and having a longitudinal direction corresponding to the front-rear direction of the wearer and a transverse direction orthogonal to the longitudinal direction.

Preferably, the concave-convex region has a first direction and a second direction orthogonal to the first direction, and each of the concave-convex regions has a plurality of convex portions having a length in the first direction longer than a length in the second direction, and concave portions located between the convex portions in the first direction or the second direction.

Preferably, the concave portion has a low grammage portion having a smaller grammage of the fiber material than the convex portion.

Preferably, the elastic member is disposed in the first direction at a position closer to the non-skin-facing surface than the skin contact piece.

Drawings

Fig. 1 schematically shows an expanded plan view of a skin-facing surface side (inner surface side) in an expanded and elongated state of a disposable diaper as an embodiment of an absorbent article of the present invention.

Fig. 2 is a sectional view of fig. 1 at II-II.

Fig. 3 is a plan view showing a front sheet (skin contact sheet) of the disposable diaper according to the first embodiment.

Fig. 4 is an enlarged plan view showing a part of the concave-convex area P of the skin contact sheet shown in fig. 3 in an enlarged manner.

Fig. 5 is a plan view of the convex portion of the skin contact sheet overlapping the elastic member and a sectional view corresponding thereto, fig. 5 (a) is a view showing the convex portion before deformation, and fig. 5 (b) is a view showing the convex portion after deformation.

Fig. 6 is a cross-sectional view showing an example of the arrangement relationship between the uneven area of the skin contact sheet and the elastic member.

Fig. 7 is a cross-sectional view showing another example of the arrangement relationship between the uneven area of the skin contact sheet and the elastic member.

Fig. 8 is a cross-sectional view showing still another example of the arrangement relationship between the uneven area of the skin contact sheet and the elastic member.

Fig. 9 is a view showing an example of a cross-sectional structure of a skin contact sheet according to another embodiment.

Fig. 10 is a view corresponding to fig. 4 showing a further embodiment of the uneven area in the skin contact sheet.

Fig. 11 is a view corresponding to fig. 4 showing a further embodiment of the uneven area in the skin contact sheet.

Fig. 12 is a view corresponding to fig. 4 showing a further embodiment of the uneven area in the skin contact sheet.

Fig. 13 is a perspective view showing a further embodiment of the uneven area in the skin contact sheet.

Fig. 14 is a partially cut-away perspective view showing a stretchable sheet that can be used for the elastic member of the present invention.

Detailed Description

In the sheet having the concave-convex shape, the larger the normal size of the convex portion which is in contact with the skin of the wearer, the more easily the convex portion follows the skin of the wearer, and thus, a good skin touch is easily obtained. However, when the convex portion is overlapped with the elastic member having elasticity in one direction, the convex portion may collapse entirely due to contraction of the elastic member, and the collapsed portion may be in close contact with the skin, thereby reducing air permeability. Patent documents 1 to 3 do not disclose a technique for solving the problem of the convex portion collapsing due to the shrinkage of the elastic member.

The invention provides an absorbent article which can effectively inhibit the collapse of a convex part caused by the shrinkage of an elastic member without damaging the touch feeling of the skin generated by the convex part.

The present invention will be described below with reference to the drawings based on preferred embodiments.

Fig. 1 and 2 show a basic structure of a disposable diaper 1 (hereinafter also simply referred to as diaper 1) as an embodiment of an absorbent article of the present invention.

As shown in fig. 1 and 2, the diaper 1 has a liquid-permeable front sheet 12, a liquid-impermeable back sheet 13, and an absorber 14 disposed between the two sheets 12, 13. The liquid impermeability of the back sheet 13 also includes a concept of liquid impermeability, and the back sheet 13 includes a case of being constituted of a water repellent sheet or the like in addition to a case where liquid does not pass through at all. As will be described later, the front sheet 12 has a structure in which the skin facing surface has a concave-convex area P, PS, and the concave-convex area P, PS is omitted in fig. 1 and 2.

Fig. 1 is a view showing an unfolded and extended state of a diaper 1. The diaper 1 has a longitudinal direction X corresponding to the front-rear direction of the wearer ₁ And with the longitudinal direction X ₁ Orthogonal transverseIn the Y direction ₁ . In addition, the diaper 1 will have a longitudinal direction X ₁ The total length 3 of (a) can be divided into a side portion a disposed on the front side of the wearer when worn, a back portion B disposed on the back side of the wearer when worn, and a crotch portion C located between the side portion a and the back portion B.

The diaper 1 is a disposable diaper of a developed type, and fastening tapes 17 are provided on both side edges of the back side portion B, and fastening regions 18 for fastening the fastening tapes 17 are provided on the outer surface of the abdomen side portion a.

In the present specification, the term "developed and extended state" of the diaper 1 means a state in which the diaper 1 is brought into a developed state and the developed state is expanded to a state in which the elastic members of the respective portions are extended to have a designed size (the same size as when the diaper is expanded into a planar shape in a state in which the influence of the elastic members is removed). The "skin-facing surface" is a surface facing the skin of the wearer when the diaper or a component (e.g., an absorber) thereof is concerned, and the "non-skin-facing surface" is a surface facing the opposite side of the skin of the wearer when the diaper is worn. That is, the skin-facing surface is a surface on the side facing the skin of the wearer, and the non-skin-facing surface is a surface on the side facing away from the skin of the wearer. "when worn" and "wearing state" refer to a state in which the diaper is worn while maintaining an appropriate wearing position.

The absorbent body 14 of the diaper 1 has an absorbent core 14a and a core-covering sheet 14b including the absorbent core 14a.

The absorbent core 14a may be composed of, for example, a fiber laminate of liquid absorbent fibers such as pulp fibers, or a mixed fiber laminate of liquid absorbent fibers and a water absorbent polymer. Examples of the liquid-absorbent fibers include pulp fibers, rayon fibers, cotton fibers, cellulose-based hydrophilic fibers such as cellulose acetate, and the like. In addition to cellulose-based hydrophilic fibers, fibers hydrophilized with a surfactant or the like for fibers formed of synthetic resins such as polyolefin, polyester, polyamide, and the like can be used.

As the core wrap 14b, for example, tissue paper or water-permeable nonwoven fabric can be used. The core-spun sheet 14b may cover the entire absorbent core 14a with 1 sheet, or may cover the absorbent core 14a by combining 2 or more sheets. As the back sheet 13, a resin film which is impermeable to liquid or water repellent, a laminate of a resin film and a nonwoven fabric, or the like can be used.

In the longitudinal direction X of the diaper 1 ₁ A three-dimensional wrinkle formation sheet 15 having a three-dimensional wrinkle formation elastic member 15a is disposed on both sides of the wearer, and three-dimensional wrinkles rising toward the skin of the wearer are formed in the crotch portion C in the worn state by contraction of the three-dimensional wrinkle formation elastic member 15 a.

Further, the leg elastic members 16 are disposed in an extended state at the portions of the crotch portion C disposed around the legs, and the crotch portion C in a worn state forms leg gathers that improve fit around the legs of the wearer by contracting the leg elastic members.

In the present embodiment, the extension and contraction directions of the three-dimensional fold forming elastic member 15a and the leg elastic members 16 are respectively equal to the longitudinal direction X of the diaper 1 ₁ And consistent.

The diaper 1 of the present embodiment has a longitudinal direction X from the absorber 4 in the back side portion B ₁ Is directed in the direction X ₁ An outboard extending waist flap portion WF. The waist wing WF is formed by a longitudinal direction X of the absorbent body 4 ₁ Is further directed in the direction X ₁ Is formed by a part extending outside the sleeve. In the present embodiment, the waist wing WF extends from the end edge of the absorber 4 in the longitudinal direction X ₁ Is composed of a three-dimensional fold forming sheet 15 extending outward of the front sheet 12 and the back sheet 13. The sheets are bonded to each other at the extending portions of the absorbent body 4 from the end edges by a known bonding method such as an adhesive, heat sealing, and ultrasonic sealing. The waist wing WF corresponds to the waist circumference of the wearer when the diaper 1 is worn.

In the diaper 1 of the present embodiment, as shown in fig. 1, in the waist wing WF of the back side portion B, the waist elastic member 19 is provided so as to extend in the lateral direction Y ₁ The upper extension is configured in an extended state. By contraction of the waist elastic member 19, waist gathers are formed in the waist portion disposed on the back side of the wearer. In the present embodiment, the waist elastic member 19 is disposed between the front sheet 12 and the back sheet 13 in the waist panel WF along the lateral direction Y ₁ In an elongated shapeAnd (5) fixing the state. The diaper 1 may have the waist elastic member 19 in the waist wing WF of the abdomen-side portion a. In the present embodiment, the extension and contraction direction of the waist elastic member 19 is the same as the lateral direction Y of the diaper 1 ₁ And consistent.

The diaper 1 has a skin contact sheet 10 which contacts the skin of the wearer in the wearing state of the diaper. The skin contact sheet 10 has a concave-convex area in which a plurality of convex portions and concave portions are formed, and in the worn state, the concave-convex area, more specifically, the convex portions are in contact with the skin of the wearer.

In the diaper 1 of the present embodiment, the front sheet 12 is the skin contact sheet 10, and the skin-facing surface of the front sheet 12 has uneven regions.

As shown in fig. 3, the front sheet 12, i.e., the skin contact sheet 10 of the present embodiment has a sheet shape located in the lateral direction Y ₁ A central region M at the center of the (c) and a pair of side regions S, S located on both sides of the central region M. The central region M and the pair of side regions S, S each have a concave-convex region, and the convex and concave portions in these two regions M, S are formed by different arrangement patterns. Hereinafter, the concave-convex area P in the central area M is referred to as a "central concave-convex area P", and the concave-convex area PS in the side area S is referred to as a "side concave-convex area PS".

In the skin contact sheet 10 of the present embodiment, the central uneven area P has a first direction Y and a second direction X orthogonal to the first direction Y. In the present embodiment, the first direction Y is the transverse direction Y of the diaper 1 ₁ In agreement with the longitudinal direction X of the diaper 1 in the second direction X ₁ And consistent. The central concave-convex area P is formed over the entire area of the central area M.

The central concave-convex area P has a plurality of convex portions 41 having a length in the first direction Y longer than a length in the second direction X. Hereinafter, the convex portion 41 longer in the first direction Y is also referred to as a "long convex portion 41". The concave-convex region P may have a plurality of long convex portions 41 and a plurality of concave portions 31 located between the long convex portions 41 in either one of the first direction Y and the second direction X.

The long protruding portion 41 of the present embodiment has a substantially diamond shape in plan view, and has a major axis direction aligned with the first direction Y and a minor axis direction aligned with the second direction X.

In the central concave-convex region P, as shown in fig. 3 and 4, the long convex portions 41 are formed in a state of being dispersed in the first direction Y and the second direction X.

More specifically, as shown in fig. 3, the long protrusions 41 are arranged in a staggered manner, and a plurality of longitudinal protrusion rows R5 are formed in the first direction Y, in which the long protrusions 41 are arranged along the second direction X.

The arrangement positions of the long protrusions 41 of the longitudinal protrusion rows R5 adjacent to each other in the first direction Y are shifted by a half pitch in the second direction X. The long protrusions 41 of the longitudinal protrusion rows R5 adjacent to each other in the first direction Y are arranged such that a part of the long protrusions 41 overlap each other in the second direction X.

Longitudinal protrusion rows R5 of the long protrusions 41 whose positions in the second direction X coincide with each other are formed at equal intervals in the first direction Y. With this configuration, the size of each of the long protruding portion 41 and the large recessed portion 31 described later can be easily made uniform, and the skin feel and ventilation due to the uneven region P can be further improved.

In the central uneven region P, a plurality of rows of the lateral convex rows R6, in which the plurality of long convex portions 41 are arranged along the first direction Y, are formed in the second direction X. The lateral protrusion rows R6 of the long protrusions 41 whose positions in the first direction Y coincide with each other are formed at equal intervals in the second direction X from each other.

In the present embodiment, the central concave-convex area P has a plurality of concave portions 31, 33 located between the long convex portions 41 in the first direction Y and the second direction X. The central concave-convex area P has 2 kinds of concave portions 31, 33 different in size. Hereinafter, the large concave portion 31 is referred to as a "large concave portion 31", and the small concave portion 33 is referred to as a "small concave portion 33".

In the present embodiment, the central concave-convex region P has large concave portions 31 between the end edges of the long convex portions 41 of the longitudinal convex portion row R5 in the second direction X and between the end edges of the long convex portions 41 of the lateral convex portion row R6 in the first direction Y.

The large concave portion 31 of the present embodiment has a low grammage portion 32 having a smaller grammage of the fiber material than the long convex portion 41. The low basis weight portion 32 may be a low fiber accumulation portion in which the basis weight of the fiber material is smaller than that of the long protruding portion 41 and the fiber material is present, or may be an opening penetrating the skin contact sheet 10 without the fiber material. The low grammage portion 32 is preferably the above-described hole from the viewpoint of facilitating deformation of the long protruding portion 41 described later.

The large concave portion 31 of the present embodiment has a high-density portion 35 (see a cross-sectional view of fig. 5 (a)) at the peripheral edge portion of the low-gram-weight portion 32, which is formed by high-density fiber material by embossing or the like. Instead of this structure, the large concave portion 31 may not have the high density portion 35 at the peripheral edge portion of the low grammage portion 32. In the plan views (plan views) of fig. 4 and 5, the high-density portion 35 is omitted.

As shown in fig. 3 and 4, the low grammage portions 32 formed in the large concave portions 31 are also arranged in a staggered manner. In more detail, the plurality of low basis weight portions 32 are arranged along the second direction X in longitudinal low basis weight portion rows R1 at intervals in the first direction Y. The arrangement positions of the low grammage portions 32 of the longitudinal low grammage portion rows R1 adjacent to each other in the first direction Y are shifted by a half pitch in the second direction X.

The longitudinal low grammage portion rows R1 of the plurality of rows are formed at equal intervals in the first direction Y. The interval between the longitudinal low grammage portion rows R1 in the first direction Y is a distance between the centerlines of the longitudinal low grammage portion rows R1 in the first direction Y that are 2 equal to each other when the sizes of the low grammage portions forming the low grammage portion rows are different.

In the central uneven region P, a plurality of rows of lateral low grammage portion rows R2, which are arranged along the first direction Y, are formed in the second direction X.

In fig. 4, a region where the longitudinal low basis weight portion row R1 overlaps the longitudinal convex portion row R5 in the first direction Y is denoted by a symbol f.

In the central concave-convex region P, the long convex portions 41 and the large concave portions 31 are alternately arranged in the first direction Y and the second direction X. That is, the longitudinal concave-convex rows R10 in which the long convex portions 41 and the large concave portions 31 are alternately arranged along the second direction X are formed in a plurality of rows in the first direction Y.

The positions of the long protrusions 41 and the positions of the large recesses 31 of the longitudinal concave-convex rows R10 adjacent to each other in the first direction Y are shifted by half a pitch in the second direction X.

The central concave-convex region P of the present embodiment has a pair of small concave portions 33, 33 sandwiching the long convex portion 41 in the second direction X on both sides of the large concave portion 31 in the first direction Y. The pair of small recesses 33, 33 are arranged in series along the second direction X, and a plurality of rows of the pair of small recesses 33, 33 are formed at regular intervals in the first direction Y. The positions of the small concave portions 33 forming a row of the pair of small concave portions 33, 33 adjacent in the first direction Y coincide in the second direction X.

In the diaper 1, an elastic member is disposed along the first direction Y on the non-skin-facing surface side of the skin contact sheet 10. In the present embodiment, a waist elastic member 19 is disposed in an elongated state along the first direction Y on the non-skin-facing surface side of the skin contact sheet 10, which is the front sheet 12, and the waist elastic member 19 is formed so as to exhibit stretchability along the first direction Y.

In the diaper 1 of the present embodiment, the waist elastic member 19 overlaps the central uneven region P in the waist wing WF.

The long convex portion 41 of the present embodiment has a portion a overlapping the large concave portion 31 in the first direction Y [ refer to fig. 5 (a) ]. When the waist elastic member 19 exhibiting stretchability in the first direction Y contracts, the central uneven region P is compressed in the first direction Y, and the skin contact sheet 10 deforms. Specifically, since the large concave portion 31 is compressed in the first direction Y, the portion a of the long convex portion 41 overlapping with the large concave portion 31 in the first direction Y is also compressed in the first direction Y. The long protruding portion 41 compressed in the first direction Y is deformed such that the portion a overlapping the large recessed portion 31 in the first direction Y is bent inward [ see fig. 5 (b) ]. Such deformation caused by the contraction of the elastic member is hereinafter also referred to as "inward folding", and the portion capable of being inward folded is also referred to as "inward folded portion a".

As described above, in the diaper 1 of the present embodiment, by partially deforming the long protruding portion 41, it is possible to effectively suppress the entire protruding portion from collapsing due to the contraction of the elastic member 19 without impairing the skin feel caused by the long protruding portion 41. In this way, the convex shape of the long convex portion 41 is well maintained in the central concave-convex region P, so that the skin contact sheet 10 can be suppressed from being in close contact with the skin of the wearer, and the choke heat in the diaper 1 in the worn state can be suppressed, thereby providing good ventilation.

From the viewpoint of further improving the feel and air permeability of the skin, it is preferable that the long protruding portion 41 is folded inward by contraction of the elastic member 19, and the state before the folding is restored by extension of the elastic member 19.

In the central concave-convex region P of the present embodiment, the long convex portion 41 overlaps with the longitudinal low grammage portion row R1 in the first direction Y. The large concave portion 31 has a low grammage portion 32 having lower rigidity than other portions. According to this structure, the large concave portion 31 is more easily compressed in the first direction Y by the contraction of the elastic member 19 [ refer to fig. 5 (b) ]. With this compression, the portion a of the long protruding portion 41 overlapping the large recessed portion 31 in the first direction Y is more easily compressed in this direction Y, and thus the inward folding of the long protruding portion 41 is more easily generated [ refer to fig. 5 (b) ].

In the present embodiment, the inward fold portion a is located on the skin-facing surface side of the low basis weight portion 32. The elastic member 19 is located on the non-skin-facing surface side of the low basis weight portion 32.

From the viewpoint of improving the ventilation in the diaper 1, it is preferable that the long protruding portions 41 are folded in a plurality of portions. For example, the concave-convex region P preferably has a region f in which a plurality of longitudinal low basis weight portion rows R1 and longitudinal convex portion rows R5 overlap in the first direction Y.

From the viewpoint of facilitating the occurrence of the inward folding in the long protruding portion 41, the elongation stress of the elastic member 19 is preferably 8cN/10mm or more, more preferably 10cN/10mm or more, still more preferably 50cN/10mm or less, still more preferably 40cN/10mm or less, yet still more preferably 8cN/10mm or more and 50cN/10mm or less, still more preferably 10cN/10mm or more and 40cN/10mm or less. Elongation stress was measured by the following method.

[ method for measuring elongation stress ]

From the diaper in the developed and stretched state, an elastic member disposed at a position overlapping with the concave-convex region P and a region exhibiting stretchability in the elastic member were cut out by 50mm in the stretch direction. The cut test pieces were clamped to a pair of chucks of a TENSILON tensile tester (RTC-1210A, manufactured by ORIENTEC). The distance between chucks at this time was set to 10mm. Then, after the sample piece was elongated at a speed of 50mm/min until the distance between chucks became 40mm, the tensile load (cN/10 mm) at which the distance between chucks was recovered to 38mm was measured. This measurement was repeated 3 times, and the average (average of tensile loads when the distance between chucks was returned to 38 mm) was used as the elongation stress (cN/10 mm).

In the case where the low basis weight portion 32 is a low fiber-accumulating portion, the basis weight of the fiber material in the low basis weight portion 32 is preferably in the following range from the viewpoint of making the long protruding portion 41 more likely to be folded inwards.

The gram weight of the fiber material in the low gram weight portion 32 is preferably 10% or less, more preferably 20% or less, relative to the gram weight of the fiber material in the long protruding portion 41.

The grammage of the fibrous material in the low grammage portion 32 is preferably 30g/m ² Hereinafter, it is more preferably 20g/m ² The following is given.

The inward folded portion a of the inward folded long convex portion 41 is formed by a valley portion v recessed into the long convex portion 41 and a peak portion m on the skin-facing surface side of the valley portion [ see fig. 5 (b) ]. From the viewpoint of easier formation of the peak m, the long protruding portion 41 preferably has a portion where the constituent fibers of the skin contact sheet 10 are oriented in the second direction X. The portion oriented in the second direction X is not easily subjected to the force of compressing the low grammage portion 32, that is, the force of contracting in the first direction Y, so that the peak m in the folded-in portion a is easily formed.

In addition, from the viewpoint of easier formation of the valley portions v, the long protruding portions 41 preferably have portions in which the constituent fibers of the skin contact sheet 10 are oriented in the first direction Y. The portion oriented along the first direction Y is susceptible to a force compressing the low grammage portion 32, that is, a force contracting in the first direction Y, and therefore the valley portions v in the folded-in portion a are easily formed.

From the viewpoint of easier formation of the folded-in portion a, it is preferable that the long protruding portion 41 has a portion in which the constituent fibers of the skin contact sheet 10 are oriented in the first direction Y, and has portions in which the constituent fibers are oriented in the second direction X on both sides of the portion oriented in the first direction Y.

The orientation of the fibers in the sheet can be confirmed by the following method, for example. First, the sheet to be evaluated is peeled off by cold spraying or the like and taken out from the absorbent article. The taken out sheet was cut into a square shape in plan view having a length of 2cm along the second direction X and a length of 2cm along the first direction Y by a cutter or the like, and the square shape was used as a measurement sheet. The measuring piece is cut so as to include the long protruding portion 41. Then, the long convex portion in the measurement piece is observed with a microscope (for example, digital microscope VHX-1000 manufactured by KEYENCE corporation) at a magnification of 60 to 200 times. For any fiber observed in a certain observation area (for example, 1mm square), two points at which the length of the fiber is maximum in the area are determined. Then, an angle between a straight line connecting the two ends and the first direction Y is measured. The measurement was performed for at least 3 observation regions, and the fiber orientation direction was obtained from the arithmetic average of the angles measured for a total of 30 or more fibers. The fiber orientation direction is determined to be oriented in the first direction Y when the angle with the first direction Y is 45 degrees or less, and is determined to be oriented in the second direction X when the angle with the first direction Y exceeds 45 degrees. In the measurement of the fiber orientation, it is preferable to observe the fiber at a magnification at which 10 or more fibers can be confirmed in this region.

From the viewpoint of making the long protruding portion 41 more likely to be folded inwards, the long protruding portion 41 preferably satisfies the following expression (1) when the elastic member 19 is maximally stretched.

La>H1……(1)

La: half of the length L1 of the long protrusion 41 in the first direction Y

H1: height of the long convex part 41

The length L1 of the long protruding portion 41 in the first direction Y is the maximum length of the long protruding portion 41 in the direction Y (see fig. 4).

In addition, H1 was measured by a thickness measuring instrument in a state where a load of 0.05kPa was applied to the skin contact sheet 10. As the thickness measuring device, for example, a laser displacement meter (LK-080, manufactured by KEYENCE Co., ltd.) is used.

From the same viewpoints as described above, when one half (L1/2) of the length of the long protruding portion 41 in the first direction Y is La and the height of the long protruding portion 41 is H1 (see fig. 5 (a)), the La/H1 ratio, which is the ratio of La to H1, is preferably 1.5 or more, more preferably 2.0 or more, still more preferably 15.0 or less, still more preferably 10.0 or less, still more preferably 1.5 or more and 15.0 or less, and still more preferably 2.0 or more and 10.0 or less.

From the same point of view as described above, when the length of the long protruding portion 41 in the first direction Y is L1 (see fig. 4) and the length of the long protruding portion 41 in the second direction X is L2 (see fig. 4), the ratio L1/L2 of L1 to L2 is preferably 1.5 or more, more preferably 1.8 or more, still more preferably 5.0 or less, still more preferably 3.0 or less, still more preferably 1.5 or more and 5.0 or less, still more preferably 1.8 or more and 3.0 or less.

From the viewpoint of further compressing the low grammage portion 32 and making the inward folding of the long protruding portion 41 more likely to occur, when the length of the long protruding portion 41 in the second direction X is L2 (see fig. 4) and the length of the low grammage portion 32 in the second direction X is L5 (see fig. 4), the ratio of L5 to L2, i.e., L5/L2, is preferably 0.3 or more, more preferably 0.4 or more, still more preferably 0.8 or less, still more preferably 0.7 or less, still more preferably 0.3 or more and 0.8 or less, still more preferably 0.4 or more and 0.7 or less.

From the viewpoint of being more likely to receive the force of compressing the low grammage portion 32 in the first direction Y and causing the inward folding in the long convex portion 41 to be more likely to occur, when the length of the long convex portion 41 in the second direction X is L2 (see fig. 4) and the length of the low grammage portion 32 in the first direction Y is L6 (see fig. 4), the ratio L6/L2 of L6 to L2 is preferably 0.3 or more, more preferably 0.4 or more, still more preferably 1.5 or less, still more preferably 1.0 or less, still more preferably 0.3 or more and 1.5 or less, and still more preferably 0.4 or more and 1.0 or less.

The long protruding portion 41 of the present embodiment has only 1 portion a overlapping the large recessed portion 31 in the first direction, that is, the folded-in portion a in the first direction Y.

When the length of the long protruding portion 41 in the first direction Y is L1 (see fig. 4), and the length of the inward folded portion a in the first direction Y is L10 (see fig. 5 (b)), the ratio of L10 to L1, i.e., L10/L1, is preferably 0.2 or more, more preferably 0.3 or more, still more preferably 0.8 or less, still more preferably 0.7 or less, still more preferably 0.2 or more and 0.8 or less, still more preferably 0.3 or more and 0.7 or less. The length L10 of the inward folded portion a in the first direction Y is the maximum length along the first direction Y of the valley portion v in the long convex portion 41 of the inward fold [ refer to fig. 5 (b) ].

As described in the third and fourth embodiments described later, when the long protruding portion 41 has a plurality of folded-in portions a along the first direction Y, the length L10 of the folded-in portions a in the first direction Y is the sum of the lengths of the plurality of folded-in portions a in the first direction Y. For example, as described in the third embodiment, 1 long convex portion 41 has 2 inward folded portions a ₁ 、a ₂ In the case of (a), the length L10 of the inward fold in the first direction Y is the 2 inward folds a ₁ 、a ₂ Is the sum of the lengths in the first direction Y.

From the viewpoint of further improving the feel of the skin in the uneven region P, the dimensions of the long protruding portion 41 and the low grammage portion 32 are preferably in the following ranges.

The length L1 (see fig. 4) of the long protruding portion 41 in the first direction Y is preferably 4.0mm or more, more preferably 6.0mm or more, still more preferably 35.0mm or less, still more preferably 25.0mm or less, still more preferably 4.0mm or more and 35.0mm or less, still more preferably 6.0mm or more and 25.0mm or less.

The length L2 (see fig. 4) of the long protruding portion 41 in the second direction X is preferably 2.0mm or more, more preferably 3.0mm or more, still more preferably 7.0mm or less, still more preferably 5.0mm or less, still more preferably 2.0mm or more and 7.0mm or less, still more preferably 3.0mm or more and 5.0mm or less.

The height H1 of the long protruding portion 41 (see fig. 5 (a)) is preferably 0.5mm or more, more preferably 0.8mm or more, still more preferably 4.0mm or less, still more preferably 3.0mm or less, still more preferably 0.5mm or more and 4.0mm or less, still more preferably 0.8mm or more and 3.0mm or less.

The length L6 (see fig. 4) of the low grammage portion 32 in the first direction Y is preferably 0.8mm or more, more preferably 1.0mm or more, still more preferably 10.0mm or less, still more preferably 7.0mm or less, still more preferably 0.8mm or more and 10.0mm or less, still more preferably 1.0mm or more and 7.0mm or less.

The length L5 (see fig. 4) of the low grammage portion 32 in the second direction X is preferably 0.8mm or more, more preferably 1.0mm or more, still more preferably 6.0mm or less, still more preferably 4.0mm or less, still more preferably 0.8mm or more and 6.0mm or less, still more preferably 1.0mm or more and 4.0mm or less.

The central concave-convex area P of the present embodiment has both large concave portions 31 and small concave portions 33 (see fig. 3). The small recess 33 of the present embodiment has an opening (not shown) as a low basis weight portion. The small recess 33 may be a structure not having a low grammage portion.

Even if the elastic member exhibiting stretchability in the first direction Y contracts, the long protruding portion 41 of the present embodiment does not fold inward in the portion sandwiched between the small recessed portions 33 in the second direction X. As described above, the central concave-convex region P may have the concave portion 33 which does not contribute to the inward folding of the long convex portion 41.

Examples of the concave portion 33 that does not contribute to the inward folding of the long convex portion 41 include a concave portion having a length of less than 0.5mm in the first direction Y, a concave portion that does not have a low grammage portion and is formed by isostatic densification by embossing, and the like.

In the diaper 1 of the present embodiment, the waist elastic member 19 can be formed along the lateral direction Y ₁ And (5) telescoping. The waist elastic member 19 and the central concave-convex region P are arranged in the longitudinal direction X ₁ The end portions of the diaper 1, specifically, the waist wing WF at the back side portion B are overlapped. In the diaper 1 of the present embodiment, since the central concave-convex region P having the inwardly foldable long convex portion 41 is disposed on the waist circumference (waist portion) of the wearer in the wearing state, the skin contact sheet 10 is easily attached to the waist circumference, and the concave-convex region P can maintain a more excellent ventilation property, and is less prone to generate stuffiness.

As shown in fig. 6, in the diaper 1 of the present embodiment, a waist elastic member 19 is disposed in an extended state between a front sheet 12 and a back sheet 13 as skin contact sheets 10 in a waist wing WF, and the front sheet 12 and the waist elastic member 19 are overlapped in a direct contact state. This structure is preferable in that the contraction force (elongation stress) of the elastic member 19 is easily applied to the large concave portion 31 or the low grammage portion 32, and the inward folding of the long convex portion 41 is more easily generated.

The skin contact sheet 10 may overlap with an elastic member disposed so as to exhibit stretchability in the first direction, with another member interposed between the skin contact sheet 10 and the elastic member. For example, as shown in fig. 7 and 8, the front sheet 12 as the skin contact sheet 10 may be overlapped with the elastic member 19 disposed so as to exhibit stretchability in the first direction Y with the absorbent body 14 interposed therebetween. In this case, from the viewpoint of further imparting a contraction force (elongation stress) of the elastic member 19 to the large concave portion 31 or the low grammage portion 32, it is preferable that the absorbent core 14a has a core low grammage portion 14c having a low grammage of the absorbent material, and the elastic member 19, the concave-convex region P having the long convex portion 41 capable of being folded inward, and the core low grammage portion 14c overlap.

The core low grammage portion 14c may be a low fiber-forming portion where the forming material of the absorbent core 14a is present but the grammage is smaller than that of a portion other than the core low grammage portion 14c in the absorbent core 14a, or may be a penetrating portion where the forming material is not present and penetrates the absorbent core 14 a.

In the case where the core low grammage portion 14c is a low fiber accumulating portion, the grammage of the absorbent material in the core low grammage portion 14c in the absorbent core 14a is preferably greater than 0%, more preferably 20% or more, still more preferably 80% or less, still more preferably 60% or less, still more preferably greater than 0% and 80% or less, still more preferably 20% or more and 60% or less, with respect to the grammage of the absorbent material in the portion other than the core low grammage portion 14c, from the viewpoint of further imparting the contraction force (elongation stress) of the elastic member 19 to the core low grammage portion 32.

From the same point of view as described above, in the case where the core low basis weight portion 14c is a low fiber accumulating portion, the basis weight of the absorbent material of the core low basis weight portion 14c is preferably more than 0g/m ² More preferably40g/m ² The above is preferably 500g/m ² Hereinafter, more preferably 400g/m ² Hereinafter, it is more preferably more than 0g/m ² And 500g/m ² Hereinafter, it is more preferably 40g/m ² Above and 400g/m ² The following is given.

In the embodiment shown in fig. 7, the first direction Y of the long protrusions 41 and the extending direction of the elastic members 19 are the same as the lateral direction Y of the diaper ₁ And consistent. On the other hand, the core low grammage portion 14c is in the longitudinal direction X ₁ Extending upwardly.

In the embodiment shown in fig. 8, the first direction Y of the long protruding portion 41, the extending direction of the elastic member 19, and the extending direction of the core low basis weight portion 14c are the same as the longitudinal direction X of the diaper ₁ And consistent. As described above, when the first direction Y of the long protruding portion 41 in the concave-convex region P coincides with the extending direction of the core low grammage portion 14c, it is preferable in terms of further improving the fit of the skin contact sheet 10.

As shown in fig. 7 and 8, it is possible to pass through the material capable of being along the transverse direction Y ₁ The contractions of the stretchable elastic member 19 may cause inward folding of the inward folding protrusions 41 in the concave-convex regions P, or may be caused by the inward folding of the protrusions in the longitudinal direction X ₁ The expansion and contraction of the elastic member causes the inward folding of the inward folding convex portion 41 in the concave-convex region P. That is, the first direction of the long convex portion 41 in the concave-convex region P can be made to be the transverse direction Y of the diaper 1 ₁ The first direction may be aligned with the longitudinal direction X ₁ And consistent.

In the embodiment shown in fig. 8, it is preferable to be able to follow the longitudinal direction X ₁ The stretchable elastic member and the concave-convex region P having the inwardly foldable long convex portion 41 are arranged in the longitudinal direction X ₁ The center portion of the diaper 1 is overlapped, and more preferably, the crotch portion C is overlapped. With such a configuration, the skin contact sheet 10 can be more effectively prevented from adhering to the skin of the wearer, and stuffiness caused by excrement such as urine absorbed into the absorber 14 and so-called liquid return in which liquid once absorbed into the absorber 14 moves to the front sheet 12 side due to the influence of body pressure of the wearer or the like can be more effectively prevented.

In the skin contact sheet 10 of the present embodiment, the side uneven area PS has the convex portions 47 and the concave portions 37 arranged in a staggered manner. The convex portion 47 in the side concave-convex area PS may be folded in by the contraction of the elastic member, or may not be folded in by the contraction of the elastic member.

The description of the central concave-convex area P described above can be applied to the case where the convex portion 47 in the side concave-convex area PS is folded inward.

Fig. 9 to 13 show another embodiment of the skin contact sheet of the present invention. The skin contact sheet according to the second to sixth embodiments described later will be mainly described with respect to the constituent parts different from those of the embodiment (first embodiment) shown in fig. 1 to 8, and the same constituent parts are denoted by the same reference numerals, and the description thereof will be omitted. The constituent parts not specifically described can be applied to the description of the first embodiment.

As shown in fig. 5 and 6, the skin contact sheet 10 of the first embodiment has a single-layer structure, and the inside of the long protruding portion 41 is solid. The non-skin-facing surface of the skin contact sheet 10 is flat in an elongated state along the first direction Y. The "extended state along the first direction Y" refers to a state in which the skin contact sheet 10 having the inwardly foldable convex portion 41 is extended in the following manner.

The diaper 1 in the developed state was developed to a design size (the same size as when developed in a planar state in a state in which the influence of the elastic member was completely removed) along the first direction Y, and the skin contact sheet 10 of the diaper 1 was marked with 2 marks in the first direction Y with a constant interval L0 (for example, 100 mm) using an oil pen. Next, the skin-contact sheet 10 is taken out from the diaper 1, and the skin-contact sheet 10 is stretched in the first direction Y until the distance between 2 marks in the sheet 10 becomes the length of the above-described constant interval L0. This state is referred to as "elongation state along the first direction Y".

Instead of the sheet having a single-layer structure, the skin contact sheet 10a of the second embodiment may be a composite sheet in which the first sheet 21 and the second sheet 22 are laminated to each other at a plurality of joining portions 36, as shown in fig. 9. In this case, the first sheet 21 is formed with a long convex portion 41 protruding in a direction away from the second sheet 22 at a portion other than the concave portions 31 and 33.

In the stretched state along the first direction Y, the surface of the composite sheet 10a formed by the second sheet 22, i.e., the non-skin-facing surface, is flat. In the composite sheet 10a, the inside of the long protruding portion 41 is hollow and has a two-layer structure of the first sheet 21 and the second sheet 22, so that the force of compression of the low grammage portion 32 is easily concentrated on the first sheet 21, and the long protruding portion 41 formed by the first sheet 21 is easily folded in.

The skin contact pieces 10b and 10c of the third and fourth embodiments shown in fig. 10 and 11 are different from the skin contact piece 10 of the first embodiment in the pattern of the concave-convex area P.

As shown in fig. 10, in the skin contact sheet 10b according to the third embodiment, the long protrusions 41 are arranged in a staggered manner, and the concave portions 31a having 4 low basis weight portions 32a are formed between the long protrusions 41 in the second direction X. The longitudinal concave-convex rows R11 in which the long convex portions 41 and the concave portions 31a are alternately arranged along the second direction X are formed in a plurality of rows along the first direction Y.

In the third embodiment, the arrangement positions of the long convex portions 41 and the arrangement positions of the concave portions 31a of the longitudinal concave-convex rows R11 adjacent to each other in the first direction Y are shifted by a half pitch in the second direction X, respectively.

Further, between the long protrusions 41 in the first direction Y, 2 sets of 2 low basis weight portions 32a (a pair of low basis weight portions 32a, 32 a) arranged along the second direction X are arranged, and these 4 low basis weight portions 32a and long protrusions 41 are alternately arranged along the second direction X.

The longitudinal concave-convex line R11 is constituted by a long convex line R4 formed by a plurality of long convex portions 41 arranged at intervals along the second direction X, and a pair of low basis weight portions 32a, 32a arranged in the second direction X between the long convex portions 41, and 2 low basis weight portion lines R3 arranged at intervals along the direction X.

In the third embodiment, the longitudinal uneven row R11 has a region f in which each long convex portion 41 and 2 low basis weight portions 32a aligned in the first direction Y overlap in the first direction Y ₁ 、f ₂ . In other words, the long convex portion 41 has a region where 2 overlaps the low grammage portion 32a in the first direction Y. The long protruding portion 41 is located at the first side of the low grammage portions 32a, 32aOverlapping region f on Y ₁ 、f ₂ In (2), the inward folding occurs preferentially by the contraction of the elastic member 19. That is, the long protruding portion 41 of the third embodiment has a plurality of inward folded portions a along the first direction Y ₁ 、a ₂ By contraction of the elastic member exhibiting stretchability in the first direction Y, the plurality of folded-in portions a ₁ 、a ₂ Each with an inward fold.

In the third embodiment, the long convex portion 41 has an inward folded portion a at 2 along the first direction Y ₁ 、a ₂ The long protruding portion 41 may have 3 or more inward folds along the first direction Y.

As shown in fig. 11, the skin contact sheet 10c of the fourth embodiment has long protrusions 41 arranged in a staggered manner, and concave portions 31b are formed between the long protrusions 41 in the second direction X, and the concave portions 31b have a quadrangular large low basis weight portion 32b and 4 small low basis weight portions 32c located on the outer side of the large low basis weight portion 32b in the substantially diagonal direction. The longitudinal concave-convex rows R13 in which the long convex portions 41 and the concave portions 31b are alternately arranged along the second direction X are formed in a plurality of rows along the first direction Y.

In the fourth embodiment, the arrangement positions of the long convex portions 41 and the arrangement positions of the concave portions 31b of the longitudinal concave-convex rows R13 adjacent to each other in the first direction Y are shifted by a half pitch in the second direction X.

In the longitudinal concave-convex row R13, the large and low grammage portions 32b and the long convex portions 41 are alternately arranged along the second direction X.

In addition, 2 small low grammage portions 32c arranged on both sides of the large low grammage portion 32b in the first direction Y are arranged along the second direction X, and these 2 low grammage portions 32c and the long convex portions 41 are alternately arranged along the second direction X.

The longitudinal concave-convex row R13 is constituted by: a long protrusion row R8 formed by a plurality of long protrusions 41 arranged at intervals along the second direction X; a pair of small low basis weight portions 32c, 32c arranged in the second direction X between the long protruding portions 41, and 2 low basis weight portion rows R7 arranged at intervals along the direction X; and large and low grammage portion columns R9 arranged at intervals along the second direction X.

In the fourth embodiment, the concave-convex array is arranged in the longitudinal directionIn R13, each of the long protruding portions 41 has a region f overlapping the large and low grammage portion 32b in the first direction Y ₄ And a region f overlapping with 2 small low grammage portions 32c in the first direction Y ₃ 、f ₅ These 3 sites. Region f at these 3 sites ₃ 、f ₄ 、f ₅ In the same manner as in the third embodiment, the inward folding occurs preferentially by the contraction of the elastic member 19. That is, the long protruding portion 41 of the fourth embodiment has 3 portions of the inward folded portion a along the first direction Y ₃ 、a ₄ 、a ₅ The inward folded parts a at these 3 positions are formed by contraction of the elastic member exhibiting stretchability in the first direction Y ₃ 、a ₄ 、a ₅ The inward folding occurs respectively.

In the concave-convex areas in the first to fourth embodiments, the long convex portions 41 and the concave portions 31 are arranged in a dispersed state, but the long convex portions 41 and the concave portions 31 may be continuously present in one direction.

As shown in fig. 12, the skin contact piece 10d of the fifth embodiment has a ridge-groove shape on the skin facing surface. Specifically, the continuous convex portions 41a forming the ridge portion extending in the first direction Y and the continuous concave portions 31d forming the groove portion extending in the same direction as the continuous convex portions 41a are alternately arranged along the second direction X. The skin-facing surface of the skin contact sheet 10d has a wavy concave-convex shape (not shown) when viewed in a direction orthogonal to the extending direction of the continuous convex portion 41a and the continuous concave portion 31 d.

The continuous concave portion 31d in the fifth embodiment has a plurality of low basis weight portions 32 at intervals along the first direction Y, and the arrangement positions of the low basis weight portions 32 in the continuous concave portion 31d adjacent in the second direction X are uniform in the first direction Y. That is, the longitudinal concave-convex rows R15 in which the low grammage portions 32 of the continuous convex portions 41a and the continuous concave portions 31d are alternately arranged along the second direction X are formed in a plurality of rows along the first direction Y.

In the fifth embodiment, in the longitudinal concave-convex rows R15 aligned along the second direction X, each continuous convex portion 41a has a plurality of regions f overlapping the low grammage portion 32 in the first direction Y ₉ . Region f at these multiple locations ₉ In the third embodiment In the same manner, the inward folding occurs preferentially by the contraction of the elastic member 19. That is, the long protruding portion 41 of the fifth embodiment has a plurality of inward folded portions a along the first direction Y ₉ By contraction of the elastic member exhibiting stretchability in the first direction Y, the plurality of folded-in portions a ₉ The inward folding occurs respectively.

As shown in the fifth embodiment, in the case where the concave-convex area has the continuous convex portion 41a and the continuous concave portion 31d, the length L1 of the long convex portion in the first direction Y is the entire length (30 mm) of the convex portion in the first direction Y when the continuous convex portion 41a is assumed to be a convex portion per unit area (30 mm square).

In addition, the inward folded part a in the first direction Y ₉ If the continuous convex portion 41a is a convex portion per unit area (30 mm square), the length L10 of the continuous convex portion is an inward folded portion a existing in the convex portion per unit area ₉ In the first direction Y. Such an inward fold a ₉ The sum L10 of the lengths in the first direction Y is an average value of the projections per unit area of 10 continuous projections 41a selected arbitrarily and 5 positions selected arbitrarily. In this case, the "convex portion per unit area" is set as the inward folded portion a of the convex portion ₉ The number of (2) is in the range of the maximum number.

As shown in fig. 13, the skin contact piece 10e of the sixth embodiment has a plurality of long protruding portions 41b protruding toward the skin-facing surface side and recessed portions 31d, and the non-skin-facing surface side of the long protruding portions 41b is open to form a space. In such a skin contact sheet 10e, the back side of the concave portion 31d, that is, the non-skin-facing surface side of the concave portion 31d protrudes toward the non-skin-facing surface side, and when the skin contact sheet 10e is viewed from the non-skin-facing surface side, the portion protruding toward the back side of the concave portion 31d becomes a convex portion protruding toward the non-skin-facing surface side. The skin-facing surface side of the concave portion 31d is open to form a space. The long protruding portions 41b and the recessed portions 31d are alternately and continuously arranged in the respective 2 directions intersecting each other in a plan view over the entire surface of the skin contact sheet 10 e.

In the sixth embodiment, the concave portion 31d has the low fiber accumulating portion described above as the low basis weight portion 32 d.

The materials forming the respective parts of the diaper according to the above embodiment will be described in detail. As the back sheet 13 and the absorber 14, materials conventionally used in absorbent articles can be used without particular limitation. As the back sheet 13, a resin film which is difficult to be permeable to liquid, a laminate of a resin film and a nonwoven fabric, or the like can be used. As the absorbent body 14, an aggregate of hydrophilic fibers such as wood pulp and hydrophilized synthetic fibers, or a material for retaining a water-absorbent polymer in the aggregate can be used as the absorbent core 14 a. The same material as that of the front sheet 12 can be used for the package sheet 14 b. As the sheet 15 for forming three-dimensional wrinkles, a water repellent nonwoven fabric can be used.

As the front sheet 12 of the skin contact sheet 10, for example, a liquid-permeable nonwoven fabric or the like conventionally used in absorbent articles can be used. Examples of the nonwoven fabric include a hot air nonwoven fabric, a spunbond nonwoven fabric, a spunlaced nonwoven fabric, a meltblown nonwoven fabric, a resin bonded nonwoven fabric, and a needled nonwoven fabric. A laminate obtained by combining 2 or more of these nonwoven fabrics may also be used.

As the fibers constituting the nonwoven fabric, fibers formed of various thermoplastic resins can be used. Examples of the thermoplastic resin include polyolefin such as polyethylene and polypropylene, polyester such as polyethylene terephthalate, polyamide such as nylon 6 and nylon 66, polyacrylic acid, polyalkylmethacrylate, polyvinyl chloride, polyvinylidene chloride, and the like. These resins can be used singly or as a mixture of 2 or more. The fiber may be used in the form of a composite fiber such as a core-sheath type fiber or a side-by-side type fiber.

Examples of the elastic members 15a, 16, and 19 include synthetic rubbers such as styrene-butadiene, isoprene, and chloroprene rubber, natural rubber, EVA, elastic polyolefin, and polyurethane. As the form of the elastic member, a linear elastic member (such as a rubber wire) having a rectangular, square, circular, elliptical, polygonal or the like cross section, a belt-like elastic member (such as a flat rubber), a multifilament-like elastic member, or the like can be preferably used.

Further, as the elastic members 15a, 16, and 19, the stretchable sheet 130 may be used. As shown in fig. 14, the stretchable sheet 130 is a member in which a plurality of elastic threads 131 arranged so as not to cross each other and extend in one direction are joined to stretchable nonwoven fabrics 132, 133 in a substantially non-stretched state over the entire length thereof.

Each elastic yarn 131 is joined to the first and second nonwoven fabrics 132, 133. The first nonwoven fabric 132 and the second nonwoven fabric 133 may be the same type of nonwoven fabric, or may be different types of nonwoven fabrics. The same nonwoven fabric as used herein refers to a nonwoven fabric having the same structure as the nonwoven fabric in terms of manufacturing process, type of constituent fibers, fiber diameter and length of constituent fibers, thickness and grammage of the nonwoven fabric. At least one of these is different and is called a different kind of nonwoven fabric. The term "elasticity" refers to a property that can be extended and that returns to a length of 125% or less of the original length when a force is released from a state of being extended by 100% with respect to the original length (a length of 200% of the original length).

Each of the nonwoven fabrics 132 and 133 is a stretchable nonwoven fabric. The nonwoven fabrics 132 and 133 can be stretched in the same direction as the direction in which the elastic strands 131 extend. The term "extendable" includes: (a) The constituent fibers of the nonwoven fabrics 132 and 133 are themselves elongated; (b) Even if the constituent fibers themselves do not elongate, the fibers bonded at the intersections separate from each other, or the three-dimensional structure formed of a plurality of fibers by bonding the fibers to each other changes in structure, or the constituent fibers are torn or the fibers are relaxed and stretched, so that the nonwoven fabric as a whole extends.

The nonwoven fabrics 132, 133 may be stretched in a state of the material before being joined to the elastic yarn 131. Alternatively, the elastic yarn 131 is processed so that the material cannot be stretched before being joined to the elastic yarn 131, but is stretched after being joined to the elastic yarn 131, thereby forming a stretchable nonwoven fabric. Specific methods for stretching the nonwoven fabric include heat treatment, roll-to-roll stretching, meshing stretching by tooth grooves and gears, and stretching by a tenter.

Each elastic strand 131 is substantially continuously present throughout the entire length of the stretchable panel 130. The elastic yarn 131 contains an elastic resin. The elastic filaments 131 are arranged so as to extend in one direction without intersecting each other. However, the accidental crossing of the elastic threads 131 due to the unavoidable variation of the manufacturing conditions of the stretchable sheet 130 is allowed. The elastic filaments 131 may extend linearly or may extend in a zigzag manner as long as they do not intersect with each other.

The stretchable sheet 130 has a structure in which the elastic filaments 131 are arranged between the 2 nonwoven fabrics 132 and 133 that can be stretched, and instead of the stretchable sheet, a stretchable sheet having a structure in which the elastic filaments 131 are arranged on one surface of the 1 nonwoven fabrics that can be stretched may be used. In this case, the elastic yarn 131 is exposed.

The skin contact sheet of the present invention can be manufactured by a known manufacturing method.

For example, the skin contact sheet 10 of the first embodiment can be manufactured by a manufacturing method having the steps of: a step of forming concave and convex portions by giving concave-convex shapes to the sheet; and forming a low grammage portion in the recess. In this manufacturing method, a sheet is introduced between an embossing convex roll and a flat roll which are disposed opposite to each other to impart a concave-convex shape, and then a low basis weight portion is formed in a concave portion of the concave-convex shape by ultrasonic treatment or the like.

The composite sheet (skin contact sheet 10 a) according to the second embodiment can be produced by the production method described in japanese patent application laid-open No. 2018-099883. The manufacturing method comprises the following steps: a step of imparting a concave-convex shape to the first sheet 21; a superposing step of superposing the second sheet 22 on the first sheet 21; and an ultrasonic treatment step of applying ultrasonic vibration to the two sheets 21, 22. In the step of imparting the uneven shape, the first sheet 21 is introduced into the engagement portion of the first roller and the second roller to be deformed into the uneven shape while rotating the first roller and the second roller having the uneven surface portion engaged with each other. The above-described overlapping step holds the first sheet 21 deformed into the concave-convex shape on the first roller and conveys the same, and overlaps the second sheet 22 on the first sheet 21 being conveyed. In the ultrasonic treatment step, ultrasonic vibration is applied between the convex portion of the first roller and the ultrasonic welding head of the ultrasonic welding machine by sandwiching the two overlapped sheets 21 and 22 therebetween, so that the low basis weight portion 32 formed by the opening penetrating the skin contact sheet 10a is formed.

In order to form the low basis weight portion 32 formed of the hole, a known cutting mechanism that can partially cut the sheet deformed into the concave-convex shape may be used in addition to the ultrasonic treatment. Examples of the cutting mechanism include a cutting device having a cutter roll and an anvil roll, and a cutting blade having a shape corresponding to the outline of the opening on the outer peripheral surface of the cutter roll.

The present invention has been described above based on preferred embodiments, but the present invention is not limited to the above embodiments and can be appropriately modified.

For example, the skin contact sheet 10 of the first embodiment has the central concave-convex region P and the side concave-convex regions PS located on both sides thereof, but the long convex portions 41 and the concave portions 31, 33 having the same pattern as the central concave-convex region P may be formed over the entire surface of the skin contact sheet 10.

The concave-convex area P may have an area overlapping the elastic member 19 and an area not overlapping the elastic member 19. In this case, the width in the first direction Y may be the same or different between the convex portion in the region overlapping the elastic member 19 and the convex portion in the region not overlapping the elastic member 19. For example, the width of the convex portion in the first direction in the region overlapping the elastic member 19 can be smaller than the width of the convex portion in the first direction in the region not overlapping the elastic member 19.

The shape of the low grammage portion 32 may be any shape that is long in the first direction Y. For example, the shape of the low basis weight portion 32 may be rectangular, elliptical, oblong, triangular, pentagonal, hexagonal, star-shaped, heart-shaped, or the like.

The absorbent article of the present invention may be a pants-type (pull-up) disposable diaper instead of the developed disposable diaper, or may be a pants-type or normal non-pants-type sanitary napkin, incontinence pad, panty liner, or the like.

With respect to the above embodiments, the present invention further discloses the following absorbent articles.

<1>

An absorbent article comprising a skin contact sheet having a concave-convex area, which is in contact with the skin of a wearer in a wearing state, and having a longitudinal direction corresponding to the front-rear direction of the wearer and a transverse direction orthogonal to the longitudinal direction,

the concave-convex area has a first direction and a second direction orthogonal to the first direction, and has a plurality of convex portions each having a length in the first direction longer than a length in the second direction, and concave portions located between the convex portions in the first direction or the second direction,

The concave portion has a low grammage portion having a grammage less than that of the fibrous material than the convex portion,

an elastic member is disposed in the first direction at a position closer to the non-skin-facing surface than the skin contact piece.

<2>

The absorbent article according to the above <1>,

in the concave-convex area, a plurality of low grammage portion columns of the low grammage portions are arranged along a second direction, a plurality of columns are formed at intervals in a first direction,

the convex portion has an inward folded portion that deforms so as to bend toward the inside of the convex portion at a portion sandwiched between the concave portions in the second direction by contraction of the elastic member.

<3>

The absorbent article according to the above <2>,

the inward fold is located on the skin-facing surface side of the low grammage portion.

<4>

The absorbent article according to the above <1>,

in the concave-convex area, a plurality of low grammage portion rows in which the plurality of low grammage portions are arranged along the second direction are formed at intervals in the first direction.

<5>

The absorbent article according to the above <2> or <4>,

the low grammage portion columns of the plurality of columns are formed at equal intervals in the first direction.

<6>

The absorbent article according to any one of the above items <1> to <5>,

the elastic member is disposed so as to exhibit stretchability in a first direction.

<7>

The absorbent article according to any one of the above items <1> to <6>,

the elastic member has an elongation stress of 8cN/10mm or more and 50cN/10mm or less, preferably 10cN/10mm or more and 40cN/10mm or less.

<8>

The absorbent article according to any one of the above items <1> to <7>,

the elastic member is located on the non-skin-facing surface side of the low basis weight portion.

<9>

The absorbent article according to any one of the above items <1> to <8>,

the grammage of the fiber material in the low grammage portion is 10% or less, preferably 20% or less, of the fiber material in the protruding portion having a length longer than the length in the second direction.

<10>

The absorbent article according to any one of the above items <1> to <9>,

the fiber material in the low gram weight part has a gram weight of 30g/m ² Hereinafter, it is preferably 20g/m ² The following is given.

<11>

The absorbent article according to any one of the above items <1> to <10>,

the low basis weight portion is formed by an opening penetrating the skin contact piece.

<12>

The absorbent article according to any one of the above items <1> to <11>,

when the length of the convex portion in the second direction is L2 and the length of the low grammage portion in the second direction is L5, the ratio of L5 to L2, i.e., L5/L2, is 0.3 or more, preferably 0.3 or more and 0.8 or less, and more preferably 0.4 or more and 0.7 or less.

<13>

The absorbent article according to any one of the above items <1> to <12>,

when the length of the convex portion in the second direction is L2 and the length of the low grammage portion in the first direction is L6, the ratio of L6 to L2, i.e., L6/L2, is 0.3 or more, preferably 0.3 or more and 1.5 or less, and more preferably 0.4 or more and 1.0 or less.

<14>

The absorbent article according to any one of the above items <1> to <13>,

the convex portion has one or more portions sandwiched between the low grammage portions in a second direction along the first direction,

when the length of the protruding portion in the first direction is L1 and the sum of the lengths of the portions sandwiched between the low grammage portions in the first direction is L10, the ratio L10/L1 of L10 to L1 is 0.2 or more, preferably 0.2 or more and 0.8 or less, and more preferably 0.3 or more and 0.7 or less.

<15>

The absorbent article according to any one of the above items <1> to <14>,

the convex portion has a portion in which constituent fibers of the skin contact sheet are oriented in a second direction.

<16>

The absorbent article according to any one of the above items <1> to <15>,

the protruding portion has a portion in which constituent fibers of the skin contact piece are oriented in a first direction.

<17>

The absorbent article according to any one of the above items <1> to <16>,

The convex portion satisfies the following formula (1) when the elastic member is maximally stretched:

La>H1……(1)

la: half the length L1 of the protrusion in the first direction,

h1: the height of the convex part.

<18>

The absorbent article of <17>,

the La/H1 ratio, which is the ratio of La to H1, is 1.5 to 15.0, preferably 2.0 to 10.0.

<19>

The absorbent article according to any one of the above items <1> to <18>,

the skin contact sheet is a composite sheet in which a first sheet and a second sheet are laminated and joined to each other at a plurality of joining portions,

the first sheet is formed with the convex portion protruding in a direction away from the second sheet at a portion other than the concave portion,

in the elongated state along the first direction, the face of the composite sheet formed by the second sheet is flat.

<20>

The absorbent article according to any one of the above items <1> to <19>,

when the length of the convex portion in the second direction is L2 and the length of the convex portion in the first direction is L1, the ratio of L1 to L2, i.e., L1/L2, is 1.5 to 5.0, preferably 1.8 to 3.0.

<21>

The absorbent article according to any one of the above items <1> to <20>,

the elastic member is capable of telescoping in the lateral direction,

The elastic member overlaps with an end portion of the absorbent article in the longitudinal direction of the concave-convex area.

<22>

The absorbent article according to any one of the above items <1> to <21>,

the elastic member is capable of telescoping along the longitudinal direction,

the elastic member overlaps with a central portion of the absorbent article in the longitudinal direction of the concave-convex area.

<23>

In the absorbent article of <22>,

having an absorbent core comprising an absorbent material,

the absorbent core has a core low grammage portion of the absorbent material extending in the longitudinal direction,

the elastic member, the concave-convex area, and the core low grammage portion overlap.

<24>

In the absorbent article of <23>,

the grammage of the core low grammage portion is greater than 0% and 80% or less, more preferably 20% or more and 60% or less, relative to the grammage of the absorbent material in the portion other than the core low grammage portion.

<25>

In the absorbent article of <23> or <24>,

the core low grammage portion has a grammage of greater than 0g/m ² And 500g/m ² Hereinafter, it is more preferably 40g/m ² Above and 400g/m ² The following is given.

<26>

The absorbent article according to any one of the above items <1> to <25>,

the elastic member is composed of a stretchable sheet in which a plurality of elastic filaments are bonded to an extensible nonwoven fabric.

<27>

The absorbent article according to any one of the above items <1> to <26>,

the concave-convex area has an area overlapping the elastic member and an area not overlapping the elastic member,

the width of the convex portion in the first direction in the region overlapping the elastic member is smaller than the width of the convex portion in the first direction in the region not overlapping the elastic member.

Industrial applicability

The present invention can provide an absorbent article capable of effectively suppressing collapse of a convex portion due to shrinkage of an elastic member without impairing the feel of the skin caused by the convex portion. The absorbent article has good air permeability.

Claims

1. An absorbent article comprising a skin contact sheet having a concave-convex area deformed into a concave-convex shape, the concave-convex area being in contact with the skin of a wearer in a wearing state, and having a longitudinal direction corresponding to the front-rear direction of the wearer and a transverse direction orthogonal to the longitudinal direction, the absorbent article characterized in that:

an elastic member is disposed in the first direction at a position closer to the non-skin-facing surface than the skin contact sheet, and a plurality of low-basis weight portions of the plurality of low-basis weight portions are arranged in the second direction in the concave-convex region at intervals in the first direction,

the convex portion has an inward folded portion which is deformed in such a manner that a portion overlapping the concave portion in the first direction is bent toward the inside of the convex portion by contraction of the elastic member,

the convex portions are formed in a dispersed state in the first direction and the second direction,

the convex portions and the low grammage portions are alternately arranged along the second direction.

2. The absorbent article of claim 1, wherein:

3. The absorbent article of claim 1 or 2, wherein:

4. The absorbent article of claim 1 or 2, wherein:

5. The absorbent article of claim 1 or 2, wherein:

the elastic member has an elongation stress of 8cN/10mm or more and 50cN/10mm or less.

6. The absorbent article of claim 1 or 2, wherein:

7. The absorbent article of claim 1 or 2, wherein:

the grammage of the fiber material in the low grammage portion is 10% or less relative to the grammage of the fiber material in the convex portion having the length in the first direction longer than the length in the second direction.

8. The absorbent article of claim 1 or 2, wherein:

the fiber material in the low gram weight part has a gram weight of 30g/m ² The following is given.

9. The absorbent article of claim 1 or 2, wherein:

10. The absorbent article of claim 1 or 2, wherein:

when the length of the convex portion in the second direction is L2 and the length of the low grammage portion in the second direction is L5, the ratio of L5 to L2, i.e., L5/L2, is 0.3 to 0.8.

11. The absorbent article of claim 1 or 2, wherein:

When the length of the convex portion in the second direction is L2 and the length of the low grammage portion in the first direction is L6, the ratio of L6 to L2, i.e., L6/L2, is 0.3 to 1.5.

12. The absorbent article of claim 1 or 2, wherein:

when the length of the protruding portion in the first direction is L1 and the sum of the lengths of the portions sandwiched between the low grammage portions in the first direction is L10, the ratio L10/L1 of L10 to L1 is 0.2 to 0.8.

13. The absorbent article of claim 1 or 2, wherein:

14. The absorbent article of claim 1 or 2, wherein:

15. The absorbent article of claim 1 or 2, wherein:

La>H1 ……（1）

la: half the length L1 of the protrusion in the first direction,

H1: the height of the convex part.

16. The absorbent article of claim 15, wherein:

the La/H1 ratio, which is the La/H1 ratio, is 1.5 to 15.0.

17. The absorbent article of claim 1 or 2, wherein:

18. The absorbent article of claim 1 or 2, wherein:

when the length of the convex portion in the second direction is L2 and the length of the convex portion in the first direction is L1, the ratio L1/L2 of L1 to L2 is 1.5 to 5.0.

19. The absorbent article of claim 1 or 2, wherein:

the elastic member is capable of telescoping in the lateral direction,

20. The absorbent article of claim 1 or 2, wherein:

The elastic member is capable of telescoping along the longitudinal direction,

21. The absorbent article of claim 20, wherein:

having an absorbent core comprising an absorbent material,

22. The absorbent article of claim 21, wherein:

the core low grammage portion has a grammage ratio of greater than 0% and 80% or less relative to the grammage of the absorbent material in a portion other than the core low grammage portion.

23. The absorbent article of claim 21, wherein:

the core low grammage portion has a grammage of greater than 0g/m ² And 500g/m ² The following is given.

24. The absorbent article of claim 1 or 2, wherein:

25. The absorbent article of claim 1 or 2, wherein: