CN116940319A

CN116940319A - Underpants-shaped disposable diaper

Info

Publication number: CN116940319A
Application number: CN202180095225.8A
Authority: CN
Inventors: 大坪俊文
Original assignee: Unicharm Corp
Current assignee: Unicharm Corp
Priority date: 2021-03-31
Filing date: 2021-12-10
Publication date: 2023-10-24
Also published as: WO2022209034A1; JP2022157105A

Abstract

An underpants-shaped disposable diaper (1) comprising: an absorbent body (10) comprising an absorbent core (11); and a waist portion (20) capable of stretching and contracting in a transverse direction, wherein, assuming that a stretched state of the waist portion (20) when stretched in the transverse direction until a size identical to a size of a single sheet-like member constituting the waist portion (20) is defined as a maximum stretched state, the waist portion (20) has a region (71) in the maximum stretched state in at least a portion outside the absorbent core (11) in the transverse direction when the waist portion (20) is stretched in the transverse direction until a size of 70% of the size of the single sheet-like member.

Description

Underpants-shaped disposable diaper

Technical Field

The present invention relates to a pants-shaped disposable diaper.

Background

In the pants-like disposable diaper, in order to prevent the diaper from slipping off the body (waist) of the wearer when the diaper is worn, it is generally widely adopted to enhance contraction around the waist by disposing as many waist elastic members (e.g., elastic strands) as possible so as to bring the diaper into close contact with the body of the wearer. For example, patent document 1 discloses a pants-like absorbent article in which a plurality of waist elastic members 52 are arranged in a waist portion E positioned around the waist and extending in the circumferential direction.

CITATION LIST

Patent literature

Patent document 1: japanese patent application laid-open No. 2001-314441

Disclosure of Invention

Technical problem

When wearing a pant-like diaper having waist elastic members (elastic strands arranged in the waist portion as described in patent document 1), there is a risk that the contraction force generated by the waist elastic members leaves linear or belt-like rubber marks on the skin of the wearer or causes skin pain, thereby causing the wearer to feel uncomfortable. On the other hand, when the contractive force is weakened so that the rubber mark is less liable to be left, there is a risk that the waist portion slides off from the wearer's body.

The present invention has been made in view of the conventional problems such as the above-mentioned problems, and an aspect of the present invention is to provide a pants-shaped disposable diaper capable of reducing discomfort caused by marks left on the skin of the wearer by elastic members while suppressing slipping of the waist portion when the diaper is worn.

Solution to the problem

One main aspect of the present invention for achieving the above-described aspects is a pants-shaped disposable diaper having a vertical direction, a lateral direction, and a front-rear direction intersecting each other, the pants-shaped disposable diaper comprising: an absorbent body comprising a liquid-absorbent core; and a waist portion capable of stretching and contracting in a transverse direction, the waist portion having a region in a maximum stretched state in at least a part of a portion located outside the absorbent core in the transverse direction when the waist portion is stretched in the transverse direction until the waist portion reaches the size of the sheet member itself constituting the waist portion, and the waist portion being stretched in the transverse direction until the waist portion reaches 70% of the size of the sheet member itself.

Other features of the invention besides those described above will become more apparent upon reading the description of the specification and upon reference to the drawings.

Advantageous effects of the invention

According to the present invention, it is possible to provide a pants-like disposable diaper capable of reducing discomfort caused by marks left on the skin of the wearer by elastic members when the diaper is worn, while suppressing slipping of the waist portion.

Drawings

Fig. 1: is a schematic perspective view of the diaper 1.

Fig. 2: is a plan view of the diaper 1 in the unfolded and maximum stretched condition.

Fig. 3: is a schematic cross-sectional view taken along line A-A in fig. 2.

Fig. 4: is a schematic cross-sectional view taken along line B-B in fig. 2.

Fig. 5: to show a schematic cross-section taken in the vertical direction when the diaper 1 is being worn.

Fig. 6: fig. 6A and 6B are schematic cross-sectional views showing a stretched state of the waist portion 20 of the diaper 1.

Fig. 7: fig. 7A and 7B are schematic views showing examples of a method of stretching the diaper 1 in the lateral direction.

Fig. 8: fig. 8A is a schematic view showing a state in which a wearer wears a conventional pants-like diaper 2 (comparative example). Fig. 8B is a schematic view showing a state in which the pants-like diaper 1 of the present embodiment is worn by a wearer.

Fig. 9: is a schematic diagram showing a modified example of the front low-scalability region 61.

Detailed Description

At least the following matters will be clarified by the description of the present specification and the accompanying drawings.

A pant-like disposable diaper having a vertical direction, a lateral direction, and a front-rear direction intersecting each other, comprising: an absorbent body comprising a liquid-absorbent core; and a waist portion capable of stretching and contracting in a transverse direction, the waist portion having a region in a maximum stretched state in at least a part of a portion located outside the absorbent core in the transverse direction when the waist portion is stretched in the transverse direction until the waist portion reaches the size of the sheet member itself constituting the waist portion, and the waist portion being stretched in the transverse direction until the waist portion reaches 70% of the size of the sheet member itself.

According to the pants-like disposable diaper described above, the region having the size equal to the size in the maximum stretched state is formed in the specific region of the waist portion located outside the absorbent core in the lateral direction, which makes it easy for the waist portion to come into face-to-face contact with the skin of the wearer in this region. Therefore, when the diaper is put on (in a 70% stretched state), the region which maintains a flat shape is brought into close contact with the waist of the wearer to be reinforced, so that the positional deviation of the waist portion is less liable to occur. Further, the waist portion is liable to maintain a flat shape, and thus the contraction force (pressure) caused by the waist elastic member or the like is dispersed. This inhibits the formation of linear marks on the wearer's skin and/or inhibits pain. This may make the wearer less prone to discomfort.

In the pants-like disposable diaper, it is desirable that the waist portion has a front waist portion and a rear waist portion, the front waist portion having an area in a maximum stretched state in at least a part of a portion located outside the absorbent core in the lateral direction when the waist portion is stretched in the lateral direction until the size of the waist portion reaches 70% of the size of the sheet-like member itself.

According to the pants-like disposable diaper described above, the portion of the front waist portion which is located outside the absorbent core in the lateral direction and which is in contact with the vicinity of the groin of the wearer is easily kept in a flat shape when the diaper is put on. This suppresses the pressure of the elastic cord or the like from locally acting on the groin. Thus, it is less likely to generate a strong contractive force around the groin and the wearer is likely to feel uncomfortable.

In the pants-like disposable diaper, it is desirable that the waist portion has a front waist portion and a rear waist portion, the rear waist portion having an area in a maximum stretched state in at least a part of a portion located outside the absorbent core in the lateral direction when the waist portion is stretched in the lateral direction until the size of the waist portion reaches 70% of the size of the sheet-like member itself.

According to the pants-like disposable diaper described above, the area in contact with the buttocks (the area of the rear waist portion located outside the absorbent core in the lateral direction) that is prone to perspiration is liable to remain flat when the diaper is put on. Therefore, heat is less likely to be trapped between the rear waist portion and the skin of the wearer, and sweat can be effectively evaporated. Thus, the stuffiness and the rash of the buttocks are suppressed, making the wearer less likely to feel uncomfortable.

In the pants-like disposable diaper, it is desirable that the rear waist portion includes a skin side sheet and a non-skin side sheet covered on a non-skin side of the skin side sheet, and that a through hole penetrating the non-skin side sheet in a thickness direction is provided in at least a part of an area of the non-skin side sheet in a maximum stretched state.

According to the pants-like disposable diaper described above, even if the rear waist portion stretches and contracts in the lateral direction when the diaper is worn, the region of the non-skin side sheet in the most stretched state (the rear low-stretch region) is less likely to contract, and is likely to maintain a flat shape. Thus, the through holes provided in this region are less prone to shrink in the lateral direction. Thus, the through holes are less prone to clogging, so that the air permeability and the evaporation function are less prone to be impaired. In addition, this improves the visibility of the through-holes when seen from the outside (non-skin side) of the diaper, thereby easily making the user recognize that the diaper has good breathability.

In the pants-like disposable diaper, it is desirable that an extensible region that stretches and contracts in the lateral direction is provided on each of both sides in the lateral direction of the region in the maximum stretched state in the waist portion.

According to the pants-shaped disposable diaper described above, when the diaper is put on, the region in the maximum stretched state (front low stretch region) is pulled to both sides in the lateral direction, brought into close contact with the skin of the wearer to be reinforced, and pulled tight. This inhibits the area from slipping off the wearer's skin. Thus, good fit can be achieved while making the wearer less prone to discomfort.

In the pants-shaped disposable diaper, it is desirable that the waist portion has a front waist portion and a rear waist portion, and in the case where the width in the lateral direction of the region in the maximum stretched state of any one of the front waist portion and the rear waist portion is larger than the width in the lateral direction of the region in the maximum stretched state of the other waist portion, the contraction force in the lateral direction of the other waist portion is larger than the contraction force in the lateral direction of the one waist portion.

According to the pants-shaped disposable diaper, when the diaper is worn, the waist portion on one side is easily pulled to both sides in the lateral direction by the contraction force of the waist portion on the other side. Therefore, the region of the waist portion on one side in the maximum stretched state (low stretch region) is liable to maintain a flat shape. This makes it easy to suppress the situation in which the waist elastic or the like leaves a linear trace on the skin of the wearer and/or causes pain.

In the pants-like disposable diaper, it is desirable that the waist portion has a skin side sheet and a non-skin side sheet overlapped in the thickness direction, and in at least a part of a portion located outside the absorbent core in the lateral direction, the waist portion has a non-joined portion in a region in a maximum stretched state, the non-joined portion being a portion in which the skin side sheet and the non-skin side sheet are not joined to each other.

According to the pants-like disposable diaper described above, in the region where the skin side sheet of the front waist portion is liable to make surface-to-surface contact with the skin of the wearer (the region located outside the absorbent core in the lateral direction), the skin side sheet is not joined with the non-skin side sheet, and thus the flexibility of the skin side sheet is increased. Therefore, the feel near the groin of the wearer can be improved. Furthermore, since the feel of the outer portion (on the non-skin side sheet side) becomes soft, this makes it easy to give the wearer the impression that the diaper is soft.

In the pants-like disposable diaper, it is desirable that the pants-like disposable diaper further include a main body joining portion joining the waist portion to the non-skin side of the absorbent main body, and in a region overlapping the main body joining portion when seen in the thickness direction, the tensile strength of the skin side sheet in the maximum stretched state and further stretched 5% in the vertical direction is greater than the tensile strength of the non-skin side sheet in the maximum stretched state and further stretched 5% in the vertical direction.

According to the pants-shaped disposable diaper described above, by making the 5% tensile strength of the skin-side sheet in the vertical direction as large as possible, the skin-side sheet can resist the pulling force even when the skin-side sheet is pulled down by the absorbent body when the absorbent body absorbs urine or the like and its weight increases. This makes the skin side panels easy to contact with the skin of the wearer while maintaining their planar shape. This makes it easy to suppress the situation in which the waist elastic or the like leaves a linear trace on the skin of the wearer and/or causes pain.

In the pants-shaped disposable diaper, it is desirable that the waist portion has a front waist portion and a rear waist portion, a pair of side joint portions are provided in both end portions in the lateral direction, the pair of side joint portions annularly connect the front waist portion and the rear waist portion, and a shortest distance from any one side joint portion to the other side joint portion along a surface of the front waist portion is longer than a shortest distance from the any one side joint portion to the other side joint portion along a surface of the rear waist portion at a specific position in the vertical direction.

According to the pants-shaped disposable diaper described above, since the contact area of the front waist portion with the skin of the wearer is larger than that of the rear waist portion, the portion of the front waist portion in the maximum stretched state (front low stretch region) is liable to be in contact with the skin of the wearer in a planar manner. This makes it easy to suppress the situation in which the waist elastic or the like leaves a linear trace on the skin of the wearer and/or causes pain.

In the pants-shaped disposable diaper, it is desirable that the waist portion has a front waist portion having a front low-stretchability region having reduced stretchability compared to other regions, and a rear waist portion having a rear first stretchability region which is a region overlapping the front low-stretchability region with respect to the vertical direction, and a rear second stretchability region which is a region adjacent to and above the rear first stretchability region, and a contractile force in the transverse direction of the rear first stretchability region acting on the region having a unit length in the vertical direction is larger than a contractile force in the transverse direction of the rear second stretchability region acting on the region having a unit length in the vertical direction.

According to the pants-like disposable diaper described above, the larger the contraction force in the lateral direction in the rear first stretchable region, the more easily the front low stretchable region is pulled and widened in the lateral direction. Therefore, making the contraction force in the lateral direction in the rear first stretchable region stronger than the contraction force in the lateral direction in the rear second stretchable region makes it possible to make the front low stretchable region more easily maintain the planar shape.

In the pants-shaped disposable diaper, it is desirable that the front waist portion has a front first stretchable region which is a region overlapping the front low stretchable region with respect to a vertical direction and is adjacent to both sides in a lateral direction of the front low stretchable region, and a contraction force in the lateral direction acting on a region having a unit length in the vertical direction in the rear first stretchable region is larger than a contraction force in the lateral direction acting on a region having a unit length in the vertical direction in the front low stretchable region and the front first stretchable region.

According to the pants-shaped disposable diaper described above, the contraction force in the lateral direction acting on the waist portion gradually increases from the front side to the rear side along the waist portion. This may, for example, make the skin of the wearer less prone to discomfort due to sudden changes in the contractive force in the waist portion of the diaper.

In the pants-shaped disposable diaper, it is desirable that the front waist portion has a front first stretchable region which is a region overlapping the front low stretchable region with respect to a vertical direction and is adjacent to both sides in a lateral direction of the front low stretchable region, and a front second stretchable region which is a region adjacent to and above the front low stretchable region and the front first stretchable region in a vertical direction, each of the front first stretchable region and the front second stretchable region is provided with a plurality of linear elastic elements, and a pitch in a vertical direction of the linear elastic elements arranged in the front second stretchable region is larger than a pitch in a vertical direction of the linear elastic elements arranged in the front first stretchable region.

According to the pants-shaped disposable diaper described above, the larger the vertical-direction interval between the front waist elastic members, the smaller the total contact area of the front waist elastic members with the skin of the wearer. Thus, linear traces of the front waist elastic are less prone to remain on the skin of the wearer when the diaper is worn. Thus, by increasing the spacing of the front waist elastics in the front second extensibility region, the trace of the front waist elastics is less likely to remain throughout the front waist portion including the front low extensibility region and the front second extensibility region adjacent to and above the front low extensibility region. This also makes the wearer less prone to discomfort.

In the pants-like disposable diaper, it is desirable that each of the rear first stretchable region and the rear second stretchable region is provided with a plurality of linear elastic members, and that the pitch in the vertical direction of the linear elastic members arranged in the rear second stretchable region is larger than the pitch in the vertical direction of the linear elastic members arranged in the rear first stretchable region.

According to the pants-shaped disposable diaper described above, since the interval between the rear waist elastic members in the rear first stretchable region is narrow, the contraction force of the rear waist elastic members acting on the rear first stretchable region tends to increase. Thus, the front low-stretchability region and the front first-stretchability region are easily pulled to both sides in the lateral direction by the rear first-stretchability region. This can prevent the rear first stretch zone from becoming loose and can allow the front first stretch zone to easily maintain a flat shape when the diaper is worn.

Examples

Hereinafter, a pant-like disposable diaper (hereinafter also referred to as "diaper 1") will be described as an example of the pant-like absorbent article according to the present invention. However, the pant-like diaper according to the present invention is also applicable to pant-like absorbent articles other than diapers, such as pant-like sanitary napkins and other pant-like absorbent articles.

Structure of diaper 1

Fig. 1 is a schematic perspective view of a diaper 1. Fig. 2 is a plan view of the diaper 1 in an unfolded and maximally stretched state. Fig. 3 is a schematic cross-sectional view taken along line A-A in fig. 2. Fig. 4 is a schematic cross-sectional view taken along line B-B in fig. 2. Note that in this specification, the "maximum stretched state" of the diaper 1 refers to a state in which the whole (whole product) of the diaper 1 is stretched to almost eliminate wrinkles, and particularly, refers to a state in which the diaper is stretched until the size of the constituent parts of the diaper 1 reaches the size of the sheet-like parts themselves constituting the parts (size matching or approaching; for example, until the difference reaches within ±5%). For example, the term "maximum stretched state" means that the front waist portion 30 is stretched until the size of the front waist portion 30 reaches the size of the skin-side panels 31 themselves constituting the front waist portion 30 (see fig. 3).

In the pant-like state shown in fig. 1, the diaper 1 has a vertical direction, a lateral direction, and a front-rear direction intersecting each other, and has a waist opening BH and a pair of leg openings LH and LH. The upper side in the vertical direction corresponds to the waist opening side, and the lower side corresponds to the crotch side. Further, the front side in the front-rear direction corresponds to the abdomen side of the wearer, and the rear side corresponds to the back side of the wearer. Further, in the unfolded state in fig. 2, the diaper 1 has a longitudinal direction and a transverse direction intersecting each other. The longitudinal direction is a direction that coincides with the vertical direction in fig. 1, and corresponds to the longitudinal direction of the absorbent main body 10. The transverse direction coincides with the transverse direction in fig. 1. Further, as shown in fig. 3, the direction in which the constituent members of the diaper 1 overlap each other is the thickness direction. In the thickness direction, the side that contacts the wearer's skin is the skin side, and the side opposite to the skin side is the non-skin side.

The diaper 1 has a liquid-absorbent main body 10 and a waist portion 20, which is arranged on the non-skin side of the absorbent main body 10. The waist portion 20 includes a front waist portion 30 corresponding to the front body of the diaper 1 and a rear waist portion 40 corresponding to the rear body of the diaper 1. That is, the diaper 1 in the present embodiment is a so-called three-piece pant-like diaper including an absorbent main body 10 as a first member (which contacts the crotch of the wearer and absorbs excretions such as urine), a front waist section 30 as a second member (which covers the front side portion of the wearer), and a rear waist section 40 as a third member (which covers the back side portion of the wearer). However, the diaper 1 is not limited to three-piece type, and may be a two-piece pant-like diaper having a waist portion 20 and an absorbent main body 10 integrally formed with a front body portion and a rear body portion.

In the developed state in fig. 2, in a state in which the front waist portion 30 and the rear waist portion 40 are arranged in parallel with each other at a spacing in the longitudinal direction, the absorbent main body 10 spans between the front waist portion 30 and the rear waist portion 40, and the end portions 10ea and 10eb of the absorbent main body 10 in the longitudinal direction (longitudinal direction) are respectively connected and fixed to the skin sides of the nearest waist portions 30 and 40, forming a substantially H-shaped outer shape in plan view. The absorbent main body 10 in this state is then folded once at a folding position, which is the center position CL in the length direction. In this folded state, the front waist portion 30 and the rear waist portion 40 facing each other are joined and connected to each other at the two side portions 30sw and 40sw in the lateral direction, forming a pair of side joint portions 50 and 50. That is, the front waist portion 30 and the rear waist portion 40 are formed in a loop shape by the pair of side joint portions 50 and 50. Thereby, the diaper 1 is formed in a pant-like state in which the waist opening BH and the pair of leg openings LH and LH are formed as shown in fig. 1. Note that the side joint portions 50 are formed by well-known joining means such as welding or bonding.

Absorbent body 10

As shown in fig. 3 and 4, the absorbent main body 10 has an absorbent core 11 that absorbs excreted liquid, a top sheet 12 that is arranged on the skin side in the thickness direction with respect to the absorbent core 11, and a back sheet 13 that is arranged on the non-skin side with respect to the absorbent core 11. However, the absorbent body 10 may also include other sheet-like components. For example, a second sheet (not shown) may be provided between the top sheet 12 and the absorbent core 11 in the thickness direction.

The absorbent core 11 is a member that absorbs and retains excreted liquid such as urine, and is formed, for example, of liquid-absorbent fibers (e.g., pulp fibers) containing superabsorbent polymers (SAP). It is noted that the outer peripheral surface of the absorbent core 11 may be covered with a liquid-permeable sheet-like member, such as tissue or nonwoven (e.g., the core-covering sheet 11b in fig. 4).

The topsheet 12 is a liquid permeable sheet made of a hydrophilic breathable nonwoven, spunbond nonwoven, or similar material. The backsheet 13 has a double-layer structure including a liquid-impermeable sheet 13a and a hydrophobic outer sheet 13b disposed on the non-skin side of the liquid-impermeable sheet 13 a. The liquid impermeable sheet 13a may be a resin film or the like, and the outer sheet 13b may be a flexible nonwoven sheet.

In both side portions in the lateral direction of the absorbent main body 10, a pair of leakage preventing wall portions 15 are provided to extend in the longitudinal direction (the longitudinal direction of the absorbent main body 10), respectively. In the present embodiment, the leakage preventing wall portion 15 is formed of the above-described outer sheet 13 b. In particular, in the transverse direction (the traverse direction), a portion of the outer sheet 13b exceeds both end portions 11es and 11es of the absorbent core 11, and is folded toward the skin side at folding positions, which are the outer ends 15es1 and 15es2 as shown in fig. 4. The pair of leakage preventing wall portions 15 is formed by further folding the outer sheet 13b at a plurality of positions on the skin side with respect to the absorbent core 11. At the skin-side end portion (front end portion) of each leakage preventing wall portion 15, a leakage preventing wall elastic member 16 (such as an elastic string) in a state stretched in the longitudinal direction (longitudinal direction of the absorbent main body 10) is attached. When the diaper 1 is put on, the leakage preventing wall portion 15 rises from the rising point (i.e., the outer ends 15es and 15 es) toward the skin side of the wearer, and therefore, the diaper 1 is fitted to the crotch of the wearer due to the stretchability formed by the leakage preventing wall elastic members 16.

Further, at both side portions in the transverse direction of the absorbent main body 10, leg elastic members 17 (such as elastic strands) in a state stretched in the longitudinal direction (the longitudinal direction of the absorbent main body 10) are attached. When the diaper 1 is put on, both side portions of the absorbent main body 10 contract due to the stretchability formed by the leg elastic members 17, and the diaper 1 is easily fitted around the legs of the wearer.

Front waist portion 30

As shown in fig. 3, the front waist portion 30 includes: a skin-side sheet 31 arranged on the skin side in the thickness direction; a non-skin side sheet 32 covered adjacent to the non-skin side of the skin side sheet 31; and a front waist elastic member 35 (hereinafter also simply referred to as "waist elastic member 35") provided between the skin side sheet 31 and the non-skin side sheet 32 in the thickness direction. The front waist portion 30 basically has a two-layer structure composed of the skin side sheet 31 and the non-skin side sheet 32, but may also have a three-layer or more-layer structure (including a skin surface sheet 36 and the like described later) in part. As shown in fig. 2, the skin side sheet 31 is a sheet-like member having a rectangular shape in a plan view, and is made of SMS nonwoven fabric or the like. Similarly, the non-skin side sheet 32 is also a sheet-like member having a rectangular shape in plan view, and is made of a spunbond nonwoven fabric or the like. Further, as the sheet-like member (especially the non-skin side sheet 32) constituting the front waist portion 30, a nonwoven fabric sheet (so-called perforated nonwoven fabric sheet) having a plurality of through holes penetrating the sheet-like member in the thickness direction may be used. Providing through holes in the sheet may improve breathability.

The front waist portion 30 of the present embodiment has a folded-back portion 32f in which an upper end portion (front end portion in the longitudinal direction) of the non-skin side sheet 32 is folded back from the non-skin side to the skin side and from the upper side to the lower side in the vertical direction. By covering a portion (upper end portion) of the skin-side sheet 31 with the folded-back portion 32f, the upper end edge of the skin-side sheet 31 is prevented from sticking into the skin of the wearer. However, the folded-back portion 32f is not necessarily provided.

The plurality of waist elastic members 35 are linear elastic members formed of elastic strands or the like, and are attached in a state stretched in the lateral direction while being arranged side by side in the vertical direction between the skin side sheet 31 and the non-skin side sheet 32. The front waist portion 30 fits around the front waist of the wearer due to the stretchability created by the waist elastics 35.

The waist elastic member 35 may be attached using an adhesive such as a hot melt adhesive. For example, the waist elastic member 35 may be attached in the following manner: the hot melt adhesive is applied to the waist elastic member 35, and the waist elastic member 35 is stretched at a predetermined stretch coefficient and sandwiched between the skin-side sheet 31 and the non-skin-side sheet 32. That is, the skin side sheet 31 and the non-skin side sheet 32 are joined with an adhesive via the waist elastic member 35. Further, the waist elastic member 35 may be attached by applying an adhesive to the side of the skin side panel 31 and the side of the non-skin side panel 32.

In addition, the front waist portion 30 may have a skin surface sheet 36. As shown in fig. 3, the skin surface sheet 36 is a sheet-like member arranged to cover the upper end 10ea (front end portion in the longitudinal direction) of the absorbent main body 10 from the skin side, and functions as a cover sheet. This prevents the upper end edge of the absorbent body 10 from poking into the skin of the wearer when the diaper 1 is worn. The skin surface sheet 36 is made of SMS nonwoven or similar material. Here, it is not necessary to provide the skin surface sheet 36.

The front waist portion 30 is joined to the non-skin-side surface of the absorbent main body 10 by a main body joining portion 23 formed of an adhesive such as a hot melt adhesive (see fig. 3). The main body joint section 23 is formed by applying an adhesive in a spiral pattern, an omega-shaped pattern, or the like in a region where the front waist section 30 and the absorbent main body 10 overlap when viewed in the thickness direction.

Rear waist portion 40

The rear waist portion 40 is substantially identical in structure to the front waist portion 30. That is, the rear waist portion 40 includes: a skin side sheet 41 arranged on the skin side in the thickness direction; a non-skin side sheet 42 covered adjacent to the non-skin side of the skin side sheet 41; and a rear waist elastic member 45 (hereinafter also simply referred to as "waist elastic member 45") provided between the skin side sheet 41 and the non-skin side sheet 42 in the thickness direction. The construction of these components is substantially the same as that of the front waist portion 30.

However, the outer shape of the rear waist portion 40 is different from the outer shape of the front waist portion 30. Specifically, as shown in fig. 2, the rear waist portion 40 includes a buttock cover 40b, and in the vertical direction, the buttock cover 40b has a substantially trapezoidal shape below the side joining portion 50 (side portion 40 sw). In the buttock cover 40b, the width in the lateral direction increases from the lower side to the upper side in the vertical direction. The buttocks cover 40b is provided so that the rear waist section 40 can cover the buttocks of the wearer when the diaper 1 is worn.

The rear waist portion 40 is joined to the non-skin-side surface of the absorbent main body 10 by a main body joining portion 24 formed of an adhesive such as a hot melt adhesive (see fig. 3). The body engagement portion 24 is formed in substantially the same manner as the body engagement portion 23.

Low-stretch region

As described above, the waist elastic members 35 and 45 are attached to the waist portion 20 (30, 40) of the diaper 1 in a state stretched in the transverse direction. The waist portion 20 has stretchability along its periphery (waist opening BH) due to the contractive force exhibited by the waist elastic members 35 and 45.

However, in the case where a strong contractive force generated by the waist elastic members 35 and 45 acts on the entire region of the waist portion 20 (30, 40), the contractive force in the entire waist portion 20 becomes more likely to become strong, resulting in a risk that the wearer feels uncomfortable due to linear marks generated by the waist elastic members 35 and 45 or discomfort due to skin pain of the wearer. Therefore, in the diaper 1 of the present embodiment, the region where the contraction force generated by the waist elastic members 35 and 45 is reduced (the low stretch region described later) compared with other regions is provided in at least a part of the waist portion 20, the situation that rubber marks remain on the skin of the wearer is suppressed.

The waist elastic member 35 provided in the front waist portion 30 of the diaper 1 includes: a continuous elastic member 35s continuous from one end (side engaging portion 50) to the other end (side engaging portion 50) in the lateral direction; and discontinuous elastic members 35c that are at least partially discontinuous in the lateral direction, respectively. In fig. 2, in the front waist portion 30, a plurality of continuous elastic members 35s, are arranged in an upper region in the vertical direction, and a plurality of discontinuous elastic members 35c, are arranged in a region adjacent to and below the region in which the continuous elastic members 35s are arranged.

Each discontinuous elastic member 35c has a discontinuous portion 61 in a central portion in the lateral direction, represented by a hatched portion in fig. 2. In the discontinuous portion 61, the contraction force generated by the waist elastic member 35 becomes weak or no contraction force is generated. That is, in the front waist portion 30, the region where the discontinuous portion 61 is formed is a low-stretchability region where the contractive force generated by the waist elastic member 35 is reduced as compared with other regions. Hereinafter, the discontinuous portion 61 will also be referred to as the front low-stretch region 61.

For example, the front low-stretchability region 61 is formed as follows. First, in the manufacturing step of the front waist portion 30, the waist elastic 35 in a state stretched in the lateral direction is adhered to the skin-side sheet 31 and the non-skin-side sheet 32 constituting the front waist portion 30. At this time, in the region where the discontinuous portions 61 are formed, the waist elastic 35 is not adhered to the skin-side sheet 31 and the non-skin-side sheet 32. Next, in the vicinity of the central position in the transverse direction, the waist elastic 35 disposed in the region overlapping the discontinuous portion 61 is cut. Then, the cut waist elastic member 35 contracts from the cut position to both outer sides in the lateral direction, and then stops contracting at the position of the end portion in the lateral direction of the discontinuous portion 61 (the position where the waist elastic member 35 is adhered). Thus, a portion of each waist elastic member 35 (discontinuous elastic member 35 c) becomes discontinuous in the lateral direction, and the front low-stretch region 61 is formed in the discontinuous portion. Thus, the operation of forming the discontinuous portion by contracting the partial range of the waist elastic 35 is also referred to as "back cut".

It should be noted that the front low-stretch region 61 may be formed by a method other than back cutting. For example, the following method may be employed: the front low stretch region 61 where the stretching/contraction force is reduced is formed by attaching the waist elastic 35 by applying an adhesive on the entirety of the front waist portion 30 and then cutting the waist elastic 35 at a plurality of positions in a predetermined region (region where the discontinuous portion 61 is to be formed) so that the waist elastic 35 becomes discontinuous.

In fig. 2, in the front waist portion 30, a region overlapping with the front low-stretchability region 61 with respect to the vertical direction and adjoining at both outer sides in the lateral direction of the front low-stretchability region 61 is defined as a front first-stretchability region 62 (a region that is shaded in the front waist portion 30 and has a length H61 in the vertical direction in fig. 2). Further, in the vertical direction, the adjoining region above the front low-stretchability region 61 and the front first-stretchability region 62 is defined as a front second-stretchability region 63 (a region that is a framed portion in the front waist portion 30 and has a length H63 in the vertical direction in fig. 2). The front first stretch region 62 and the front second stretch region 63 are regions in which the contraction force of the continuous elastic member 35s or the discontinuous elastic member 35c in the lateral direction is stronger than that in the front low stretch region 61.

Further, similarly to the front waist portion 30, the rear waist elastic member 45 provided in the rear waist portion 40 includes: a continuous elastic member 45s continuous from one end to the other end in the lateral direction; and discontinuous elastic members 45c, each of which is at least partially discontinuous in the lateral direction.

Each discontinuous elastic member 45c has a discontinuous portion 71 in a central portion in the lateral direction, represented by a hatched portion in fig. 2. In the discontinuous portion 71, the contraction force generated by the waist elastic 45 becomes weak or no contraction force is generated. That is, in the rear waist portion 40, the region where the discontinuous portion 71 is formed is a low-stretchability region in which the contractive force generated by the waist elastic member 45 is reduced as compared with other regions. Hereinafter, the discontinuous portion 71 is also referred to as a rear low-stretchability region 71. Similar to the front low extensibility region 61, the back low extensibility region 71 may be formed by subjecting some of the back waist elastic members 45 to back cutting. However, it is not necessary to provide the rear low stretch zone 71 in the rear waist portion 40 of the diaper 1. That is, all of the rear waist elastic members 45 may be continuous elastic members 45s.

Further, in the rear waist section 40, a region overlapping with the front low-stretchability region 61 in the vertical direction is defined as a rear first-stretchability region 81 (this region is a hatched portion in the rear waist section 40 in fig. 2, having a length H61 in the vertical direction). Further, a region adjacent to and above the rear first stretchable zone 81 in the vertical direction is defined as a rear second stretchable zone 82 (this region is a framed portion in the rear waist portion 40 in fig. 2, having a length H63 in the vertical direction).

Fig. 5 is a schematic cross-sectional view taken in the vertical direction showing the diaper 1 when the diaper 1 is put on. Fig. 5 shows a state in which a cross section of the waist portion 20 of the diaper 1 is viewed from above in the vertical direction along arrow B at a position corresponding to the view of fig. 4. In the front waist portion 30, due to the stretchability resulting from the discontinuous elastic members 35c provided in the front first stretchable zone 62, a contractive force along the waist of the wearer acts greatly in this zone when the diaper 1 is put on. On the other hand, in the front low stretch region 61, by subjecting some of the waist elastic 35 to back cutting, the stretch is reduced, and thus the contractive force along the waist of the wearer is reduced. Accordingly, the front low stretch region 61 is pulled to both sides in the lateral direction by the contraction force of the front first stretch region 62, and therefore the front low stretch region 61 in the front waist portion 30 is liable to come into surface-to-surface contact with the skin (front side) of the wearer when being stretched in the lateral direction.

Similarly, in the rear waist section 40, the contractive force along the waist of the wearer acts largely in the rear first contractive region 81 due to the stretchability generated by the continuous elastic members 45s and the discontinuous elastic members 45c provided in this region. On the other hand, in the rear low stretch region 71, the contractive force along the waist of the wearer is weakened. Accordingly, the rear low extensibility-region 71 is pulled to both sides in the lateral direction by the contractive force of the rear first extensibility-region 81, and therefore, the rear low extensibility-region 71 in the rear waist section 40 is liable to come into surface-to-surface contact with the skin (back side) of the wearer when being pulled in the lateral direction.

Fig. 6A and 6B are schematic cross-sectional views showing a stretched state of the waist portion 20 of the diaper 1. Fig. 6A shows a state in which the waist portion 20 is stretched in the transverse direction until the size of the waist portion 20 reaches the size in its maximum stretched state, and fig. 6B shows a state in which the waist portion 20 is stretched in the transverse direction until the size of the waist portion 20 reaches 70% of the size in its maximum stretched state. Note that in fig. 6B, the state in which the waist portion 20 is stretched in the transverse direction until the dimension of the waist portion 20 reaches 70% of the dimension in its maximum stretched state refers to a state corresponding to the stretched state of the waist portion 20 when the diaper 1 is put on by the wearer shown in fig. 5.

In the maximum stretched state in fig. 6A, the skin side sheet 31 and the non-skin side sheet 32 constituting the front waist portion 30 in the waist portion 20 are stretched in the lateral direction until the size of the entirety of each of the sheets 31 and 32 is equal to the size thereof. In other words, the dimension in the lateral direction of the front waist portion 30 is equal to the dimension when the skin side sheet 31 and the non-skin side sheet 32 are stretched 100% in the lateral direction. Therefore, the front low stretch region 61 in the front waist portion 30 is also in a state of being stretched by 100% in the lateral direction. Hereinafter, in a state in which the waist portion 20 is stretched 100% in the transverse direction (maximum stretched state), the dimension in the transverse direction of the waist portion 20 is defined as WE100, and the dimension in the transverse direction of the front low stretch region 61 is defined as W61.

Similarly, in the maximum stretched state, the skin side sheet 41 and the non-skin side sheet 42 constituting the rear waist portion 40 in the waist portion 20 are in a state stretched by 100% in the transverse direction, i.e., stretched until the overall size of each of the skin side sheet 41 and the non-skin side sheet 42 is equal to its own size (WE 100). Therefore, the rear low stretch region 71 in the rear waist portion 40 is also in a state of being stretched by 100% in the lateral direction. Hereinafter, the dimension in the lateral direction of the rear low-stretchability region 71 is defined as W71.

Next, in the 70% stretched state of fig. 6B, in the case where the waist portion 20 is stretched in the transverse direction until the size of the waist portion 20 reaches 70% of the size in its maximum stretched state, the size in the transverse direction of the waist portion 20 is defined as WE70, that is, 70% of WE 100. On the other hand, regarding the front low stretch region 61, its maximum stretched state is maintained by being stretched laterally outward by the contractive force of the front first stretch region 62 on both sides in the lateral direction. That is, the dimension of the front low stretch region 61 in the lateral direction in the 70% stretched state is equal to the dimension W61 of the front low stretch region 61 in the maximum stretched state.

Note that the dimension W61 of the front low stretch region 61 in the maximum stretched state (100% stretched state) and 70% stretched state of the waist portion 20 may be measured, for example, as follows. Fig. 7A and 7B are schematic views showing examples of a method of stretching the diaper 1 in the lateral direction. In stretching the diaper 1 in the transverse direction, a well-known tensile tester (e.g., a universal material tester manufactured by Instron corporation) may be used.

First, in fig. 7A, rod jigs 120A and 120B for supporting the diaper 1 are attached to the upper chuck 110 and the lower chuck of the tensile testing machine 100, respectively. The space L0 between the jigs 120A and 120B is adjusted to be equal to or smaller than the dimension in the transverse direction of the waist portion 20 of the diaper 1 in the natural state. Then, both end portions in the transverse direction of the waist portion 20 of the diaper 1 are fixed to be hooked to the jigs 120A and 120B, respectively, so as not to be displaced. It is desirable to provide an anti-slip member (e.g., a rough skin-like member) on the surface of each of the jigs 120A and 120B so that the diaper 1 is not displaced.

As shown in fig. 7B, after the diaper 1 is set in the tensile testing machine 100, the diaper 1 is stretched at a predetermined stretching speed (for example, 100 mm/min) until the space between the jigs 120A and 120B reaches L1 (L1 > L0), which is repeated a plurality of times (for example, twice). The length of the space L1 is the same as the WE100 in the maximum stretched state (100% stretched state) and the WE70 in the 70% stretched state (see fig. 5A and 5B). In the maximum stretched state of the diaper 1, and in the stretched state corresponding to 70% of the maximum stretched state, the length of the discontinuous portion 61 (i.e., the front low stretch region 61) of the discontinuous elastic member 35c shown in fig. 2 is measured, so that the length W61 in the lateral direction of the front low stretch region 61 can be obtained.

As depicted in fig. 6A and 6B, by forming an area having a size equal to that thereof in the maximum stretched state in a specific area of the waist portion 20 of the diaper 1 located outside the absorbent core 11 in the lateral direction, the waist portion 20 is made to easily come into face-to-face contact with the skin of the wearer in the area. Accordingly, the front low stretch region 61 (the rear low stretch region 71) that maintains a flat shape can be brought into close contact with the body (waist) of the wearer for reinforcement, so that the waist portion can be prevented from slipping off. The pressure of the waist elastic members 35 and 45 is dispersed on a plane, and thus, when the diaper 1 is worn, contraction force (pressure) of the waist elastic members 35 and 45 can be prevented from leaving linear marks or causing pain on the skin of the wearer. This may make the wearer less prone to discomfort. It is to be noted that, in practice, there may be a dimensional error of about ±5% in the dimension WE61 (WE 71) in the transverse direction of the front low stretch region 61 (rear low stretch region 71) in the maximum stretch state and the 70% stretch state. However, an error of about ±5% does not hinder the above effect.

In particular, in the front waist portion 30, the region on the outer side in the lateral direction of the absorbent core 11 is a portion that contacts the vicinity of the groin of the wearer when the diaper 1 is worn. When a strong contractive force acts around the groin, such force tends to cause itching or pain, which tends to cause discomfort to the wearer. In contrast, in the diaper 1 of the present embodiment, the sheet-like member is easily maintained in a flat shape at a portion (front low stretch region 61) of the front waist portion 30 that contacts the vicinity of the groin of the wearer when the diaper 1 is worn. This suppresses the pressure of the waist elastic 35 (e.g., elastic strands or the like) from locally acting on the groin. Therefore, a strong contractive force is not easily generated around the groin, and thus the wearer is not easily made uncomfortable.

In the front waist portion 30, front first stretchable regions 62 stretched and contracted in the lateral direction are provided on both sides in the lateral direction of the front low stretchable region 61 in the maximum stretched state. When the diaper 1 is put on, the front low stretch region 61 is pulled to both sides in the lateral direction by the contractive force of the front first stretch region 62, and is brought into close contact with the skin of the wearer to be reinforced and pulled tight. Therefore, even in the case where the contraction force in the lateral direction acting on the front low stretch region 61 itself is small, the front low stretch region 61 is easily prevented from slipping off from the skin of the wearer. Therefore, good fitting is easily maintained, and the wearer may also be less likely to feel uncomfortable.

Further, similarly to the front low stretch region 61 of the front waist portion 30, in the rear low stretch region 71 of the rear waist portion 40, the dimension in the transverse direction in the 70% stretched state is equal to the dimension W71 in the transverse direction in the maximum stretched state. That is, in a specific region of the rear waist portion 40 located outside the absorbent core 11 in the lateral direction, a region having a size equal to that thereof in the maximum stretched state is formed, and in this region, the rear waist portion 40 is liable to come into face-to-face contact with the skin of the wearer.

The region of the rear waist portion 40 located outside the absorbent core 11 in the lateral direction is a portion that contacts buttocks when the diaper 1 is worn, wherein the buttocks sweat more easily than the front side. Thus, when the rear waist portion 40 contracts in this region, a space is formed between the skin of the wearer and the sheet-like member, which makes it easy for heat to stagnate in this space. Thus, there is a risk of causing stuffiness and rashes. In contrast, in the diaper 1 of the present embodiment, the sheet-like member is easily maintained in a flat shape at a portion (the rear low stretch region 71) which is in contact with the buttocks which are prone to sweat when the diaper is put on. This makes it difficult for heat to be retained and makes it possible to efficiently evaporate sweat from the surface of the sheet member. This suppresses stuffiness and rash of the buttocks, making the wearer less prone to discomfort.

Further, in the case of using a perforated nonwoven having a plurality of through holes as the non-skin side sheet 42 constituting the rear waist portion 40, it is recommended that at least some of the through holes be arranged at positions overlapping with the rear low stretch region 71. That is, when the waist portion 20 is in the 70% stretched state, it is recommended that the through holes penetrating the non-skin side sheet 42 in the thickness direction be provided in the region of the non-skin side sheet 42 whose size is equal to that in the maximum stretched state and which does not overlap the absorbent core 11. The rear waist portion 40 (waist portion 20) stretches and contracts in the transverse direction when the diaper 1 is worn. However, even during such stretching and shrinking, the rear low stretch region 71 tends to maintain a maximally stretched state and a flat shape. Therefore, the through holes provided in the rear low-stretchability region 71 are also less prone to shrink in the lateral direction, so that the shape of the holes is easily maintained. Thus, the breathability and evaporation function are also not easily compromised. Further, this improves the visibility of the through hole when seen from the outside (non-skin side), and this makes it easy for the user to think of good air permeability.

Further, in the 70% stretched state of the diaper 1, in the case where the width in the transverse direction of the region in the maximum stretched state (low stretch region) of any one of the front waist portion 30 and the rear waist portion 40 is larger than the width in the transverse direction of the region in the maximum stretched state (low stretch region) of the other waist portion, it is desirable that the contraction force in the transverse direction of the other waist portion is larger than the contraction force in the transverse direction of the any one waist portion. The term "contractive force" herein refers to a force that is generated when the elastic member attempts to return from the stretched state to the original state.

For example, in fig. 6B, the width W61 of the front low stretch region 61 in the front waist portion 30 is greater than the width W71 of the rear low stretch region 71 in the rear waist portion 40. In this case, the contraction force in the lateral direction of the rear waist portion 40 is made preferably larger than the contraction force in the lateral direction of the front waist portion 30. Note that the present invention also includes a case in which the width W61 of the front low-stretch region 61 or the width W71 of the rear low-stretch region 71 is zero, that is, a case in which no low-stretch region is provided in either one of the rear side and the front side.

With this configuration, when the diaper 1 is worn, the front waist portion 30 is easily pulled to both sides in the lateral direction by the contraction force of the rear waist portion 40. Thus, the wide front low-stretch region 61 is easy to maintain a flat shape. Further, in contrast to fig. 6B, in the case where the width W61 of the front low stretch region 61 in the front waist portion 30 is smaller than the width W71 of the rear low stretch region 71 in the rear waist portion 40, the contraction force in the lateral direction of the front waist portion 30 is made larger than the contraction force in the lateral direction of the rear waist portion 40. In this case, since the rear waist portion 40 is easily pulled to both sides in the lateral direction by the contraction force of the front waist portion 30, the rear low stretch region 71 is easily maintained in a flat shape. This tends to inhibit the waist elastics 35 and 45 or the like from leaving linear marks on the wearer's skin and/or causing pain.

The contraction force in the lateral direction of the front waist portion 30 and the rear waist portion 40 can be measured using the tensile testing machine 100 described in fig. 7. For example, in the waist portion 20, the pair of side joint portions 50, 50 are peeled off, the absorbent main body 10 is cut at the center position CL (see fig. 2) in the longitudinal direction, and the front waist portion 30 and the rear waist portion 40 are separated, ready for a sample for a tensile test. Then, both ends in the lateral direction of the samples (the front waist portion 30 and the rear waist portion 40) are held by the upper chuck 110 and the lower chuck 110 (in which the jigs 120A and 120B are removed). The both ends in the lateral direction were pulled in the same manner as described above until the distance between the upper chuck 110 and the lower chuck 110 reached WE70 (70% tensile state), and the force at this time was measured. By performing such a tensile test, the magnitude of the contraction force between the front waist portion 30 and the rear waist portion 40 can be compared.

In the case where the contraction force in the lateral direction of the rear waist portion 40 is greater than the contraction force in the lateral direction of the front waist portion 30, the contraction amount in the lateral direction of the rear waist portion 40 is greater than the contraction amount in the lateral direction of the front waist portion 30. In this case, as shown in fig. 5 and 6, the positions of the side engaging portions 50 and 50 of the waist portion 20 become a state shifted to the rear side in the front-rear direction. That is, at a specific position in the vertical direction, the shortest distance from the first side joint portion 50 to the second side joint portion 50 along the surface of the front waist portion 30 is longer than the shortest distance from the first side joint portion to the second side joint portion along the surface of the rear waist portion 40. In fig. 6B, the distance (w62+w61+w62) between the side engaging portion 50 on one side and the side engaging portion 50 on the other side along the surface of the front waist portion 30 is longer than the distance (W40) between the side engaging portion 50 on one side and the side engaging portion 50 on the other side along the surface of the rear waist portion 40. Therefore, the contact area of the front waist portion 30 with the wearer's skin is larger than that of the rear waist portion 40, and the portion of the front waist portion 30 in the maximum stretched state (the front low stretch region 61) is liable to be in wider contact with the wearer's skin. This makes it easy to suppress the waist elastic member 35 or the like from leaving a linear trace and/or causing pain.

Further, the positions of the side engaging portions 50 and 50 are shifted rearward in the front-rear direction, so that the buttocks of the wearer are liable to be covered by the rear waist portion 40 positively when the diaper 1 is worn. Fig. 8A is a schematic view (comparative example) showing a state in which a wearer wears a conventional pants-like diaper 2. Fig. 8B is a schematic view showing a state in which the pants-like diaper 1 of the present embodiment is worn by a wearer.

In the pant-like diaper 2 of the comparative example shown in fig. 8A, the contraction force in the transverse direction acts uniformly on the front waist portion 30 and the rear waist portion 40, and therefore the side joint portions 50 are located at the center positions in the front-rear direction during use. In this state, the length in the lateral direction of the rear waist portion 40 (the distance between the side joint portions 50 and 50) is defined as W40A, and the angle between the tangential direction and the horizontal direction of the end edge portion of the buttock cover 40b is defined as θ1.

In contrast, in the diaper 1 shown in fig. 8B, the position of the side joint portions 50 is shifted rearward in the front-rear direction during use. In this case, the length W40B (the distance between the side joint portions 50 and 50) of the rear waist portion 40 in the lateral direction becomes shorter than W40A in fig. 8A (W40A > W40B). Therefore, the length in the lateral direction of the buttock cover 40b is also shorter as compared with fig. 8A, and the angle θ2 formed between the tangential direction and the horizontal direction of the end edge portion of the buttock cover 40b becomes larger than the angle θ1 of the comparative example (θ1< θ2). Accordingly, in the rear waist portion 40 of the diaper 1, the buttocks of the wearer are easily covered deeper by the buttocks cover 40b, so that the fit around the buttocks of the wearer can be enhanced.

Further, the waist portion 20 of the diaper 1 has, in at least a part of the region located outside the absorbent core 11 in the lateral direction, a non-joined portion where the skin side sheet 31 (41) and the non-skin side sheet 32 (42) are not joined to each other. In fig. 3, in the front low stretch region 61 (region in the maximum stretched state), the skin side sheet 31 and the non-skin side sheet 32 constituting the front waist portion 30 are not joined to each other, and the non-joined portion is positioned across the entire front low stretch region 61 (the range indicated by W61 in fig. 2) in the lateral direction. As described above, in the front low stretch region 61, the region located outside the absorbent core 11 in the lateral direction is the region in the front waist portion 30 where the skin side sheet 31 is liable to come into surface-to-surface contact with the skin generation surface of the wearer. Since the skin side sheet 31 is not joined to the non-skin side sheet 32 in this region, the flexibility of the skin side sheet 31 is increased as compared with the case where the skin side sheet is joined to the non-skin side sheet in this region. Therefore, the texture of the skin side sheet 31 in the vicinity of the groin of the wearer can be enhanced when the diaper 1 is worn. In addition, in this region, the flexibility of the non-skin side sheet 32 is also enhanced, and the tactile sensation from the external touch becomes soft, which makes it easier to give the wearer or the like the impression that the diaper 1a is soft.

Further, with respect to the body-engaging portions 23 and 24 that engage the waist portion 20 (30, 40) and the absorbent body 10, it is desirable that the 5% tensile strength in the vertical direction of the skin-side sheet 31 (41) is greater than the 5% tensile strength in the vertical direction (longitudinal direction) of the non-skin-side sheet 32 (42) in the regions overlapping the body-engaging portions 23 and 24, respectively, when seen in the thickness direction. Here, "5% tensile strength" of the sheet member in the vertical direction means a tensile strength of the sheet member when the sheet member in the maximum tensile state is stretched by an additional length of 5% in the vertical direction. That is, it means the magnitude of a force in the vertical direction acting on the region having a unit length in the lateral direction when the sheet member is stretched 5% from the maximum stretched state. Therefore, a 5% tensile strength of the skin side sheet 31 (41) in the vertical direction being greater than a 5% tensile strength of the non-skin side sheet 32 (42) in the vertical direction means that the skin side sheet 31 (41) is less likely to be stretched in the vertical direction.

When the absorbent body absorbs excrement such as urine while wearing the diaper 1, the weight of the absorbent body 10 may be increased and may tend to hang down in the vertical direction. At this time, in the portion joined to the absorbent main body 10 by the main body joining portion 23 (24), the skin-side sheet 31 (41) is pulled down by the absorbent main body 10. Therefore, if the 5% tensile strength of the skin side sheet 31 (41) in the vertical direction is small, as the weight of the absorbent main body 10 increases, the skin side sheet 31 (41) is pulled down and stretched in the vertical direction, thereby causing a risk that the skin side sheet 31 (41) cannot maintain its planar shape or the fit of the diaper 1 is deteriorated. In contrast, if the 5% tensile strength of the skin-side sheet 31 (41) in the vertical direction is made as large as possible, the skin-side sheet 31 (41) tends to resist the pulling force even if the skin-side sheet 31 (41) is pulled down by the main body engagement portion 23 (24) when the weight of the absorbent main body 10 increases, the skin-side sheet 31 (41) tends to maintain its planar shape, so that the deterioration of the fit of the diaper 1 is more easily suppressed. This tends to inhibit the waist elastic 35 or the like from leaving a linear trace and/or causing pain. In the present embodiment, since a spunbond nonwoven fabric is used as the non-skin side sheet 32 (42) and an SMS nonwoven fabric having a relatively higher tensile strength than the spunbond nonwoven fabric is used as the skin side sheet 31 (41), the above-described relationship is easily achieved.

Further, it is more desirable that the 5% tensile strength in the vertical direction is higher than the 5% tensile strength in the lateral direction in both the skin side sheet 31 (41) and the non-skin side sheet 32 (42). That is, it is desirable that the sheet-like member constituting the waist portion 20 be stretched less in the vertical direction than in the lateral direction. With this configuration, even if the waist portion 20 is pulled downward in the vertical direction with an increase in the weight of the absorbent main body 10, the sheet-like member itself is not easily pulled in the vertical direction, and thus the waist portion 20 as a whole can be prevented from slipping down. On the other hand, since the waist portion 20 is more easily stretched in the transverse direction than in the vertical direction, the waist portion is easily fitted around the waist of the wearer in accordance with stretching and contraction of the waist elastic members 35 and 45 in the transverse direction.

It should be noted that the tensile strength can be measured using the tensile testing machine 100 shown in fig. 7. For example, the skin side sheet 31 and the non-skin side sheet 32 in the front waist portion 30 are peeled off, and a strip-shaped test piece having a predetermined width in the lateral direction is cut out from each of the skin side sheet 31 and the non-skin side sheet 32, and a sample is prepared. Then, the measurement is only carried out according to the following steps: the two ends of the sample in the vertical direction were held by chucks 110 and 110 of the tensile tester 100, and the magnitudes of the forces when the sample was stretched in the vertical direction until the length reached 105% of the maximum stretched state were measured and compared.

Further, it is desirable that in the rear waist section 40, the contraction force in the transverse direction acting on the region having a unit length in the vertical direction in the rear first stretchable region 81 described in fig. 2 is larger than the contraction force in the transverse direction acting on the region having a unit length in the vertical direction in the rear second stretchable region 82. The rear first expansion/contraction region 81 is provided at a position overlapping with the front low expansion/contraction region 61 with respect to the vertical direction (within the range of H61 in fig. 2). Therefore, the larger the contraction force in the lateral direction in the rear first stretch region 81, the more easily the front low stretch region 61 is stretched and widened in the lateral direction. Therefore, by making the contraction force in the lateral direction in the rear first stretchable zone 81 stronger than the contraction force in the lateral direction in the rear second stretchable zone 82, the front low-stretch zone 61 is made easier to maintain a flat shape, whereby occurrence of a situation in which the waist elastic member 35 leaves marks or the like on the skin of the wearer can be prevented.

The contractive forces in the rear first and second zones 81, 82 may be measured as follows: a strip-shaped sample having a predetermined length in the vertical direction and extending in the lateral direction is cut from the respective regions, and the sample is subjected to a tensile test using the tensile testing machine 100 described above.

Further, it is desirable that the contraction force in the lateral direction acting on the region having a unit length in the vertical direction in the rear first stretchable region 81 of the rear waist portion 40 is larger than the contraction force in the lateral direction acting on the region having a unit length in the vertical direction in the front low stretchable region 61 and the front first stretchable region 62 of the front waist portion 30. With this configuration, in the range in the vertical direction of H61 in fig. 2, the contraction force in the lateral direction acting on the waist portion 20 becomes stronger in the order of the front low stretchability region 61, the front first stretchability region 62, and the rear first stretchability region 81. That is, the contraction force in the transverse direction acting on the waist portion 20 gradually increases from the front side to the rear side along the waist portion. This makes it possible, for example, to make the wearer's skin less likely to be uncomfortable due to an abrupt change in the contractive force in the waist portion of the diaper 1. It should be noted that the measurement of the contractive force in each region is performed using the tensile testing machine 100, and is basically the same as that described above.

Further, it is desirable that in the front waist portion 30 of the diaper 1, the average spacing in the vertical direction of the continuous elastic members 35s disposed in the front second stretchable zone 63 is larger than the average spacing in the vertical direction of the discontinuous elastic members 35c disposed in the front first stretchable zone 62. The larger the spacing of the front waist elastic 35 in the vertical direction, the smaller the total contact area of the front waist elastic 35 with the wearer's skin in this region. Therefore, the linear trace of the front waist elastic member 35 is less likely to remain on the skin of the wearer when the diaper 1 is worn. Thus, by increasing the spacing of the continuous elastic members 35s in the front second stretch region 63, the trace of the front waist elastic 35 is made less likely to remain on the entire front waist portion 30 (including the front low stretch region 61 and the front second stretch region 63 adjacent to and above the front low stretch region 61). In addition, this also makes the wearer less prone to discomfort.

However, contrary to the above-described configuration, the average pitch in the vertical direction of the discontinuous elastic members 35c arranged in the front first stretchable zone 62 may be set to be larger than the average pitch in the vertical direction of the continuous elastic members 35s arranged in the front second stretchable zone 63. In this case, the trace of the front waist elastic member 35 is less likely to remain on the skin of the wearer in the front first stretch region 62, and thus the trace of the front waist elastic member 35 is less likely to be left in the lower region of the front waist portion 30 (including the front low stretch region 61) in the vertical direction. That is, the trace of the front waist elastic member 35 can be made less likely to remain in sensitive skin portions such as the leg portions and the groin portions when the diaper 1 is put on.

Further, it is desirable that in the rear waist section 40, the average pitch in the vertical direction of the rear waist elastic members 45 arranged in the rear first stretchable zone 81 is narrower than the average pitch in the vertical direction of the rear waist elastic members 45 arranged in the rear second stretchable zone 82. With this configuration, the contraction force of the rear waist elastic member 45 acting on the rear first stretchable zone 81 is liable to be larger than the contraction force of the rear second stretchable zone 82 by an amount corresponding to the narrow pitch. Therefore, the front low stretchability region 61 and the front first stretchability region 62 are easily pulled to both sides in the lateral direction by the rear first stretchability region 81. This makes it less likely that the rear first stretchable zone 81 will come loose and more likely to maintain its planar shape when the diaper 1 is worn.

Further, as shown in fig. 4, in the lateral direction, the end portion 61es1 on one side of the front low expansion region 61 is located on one side of the rising point 15es1 with respect to one side of the leakage preventing wall portion 15, and the end portion 61es2 on the other side of the front low expansion region 61 is located on the other side of the rising point 15es2 with respect to the other side of the leakage preventing wall portion 15. That is, in the front waist portion 30, the width W61 in the lateral direction of the front low stretch region 61 is larger than the distance W15 in the lateral direction between the rising points 15es and 15es of the leakage preventing wall portion 15 (W61 > W15). Therefore, the contraction force generated by the waist elastic member 35 is less likely to act on the leakage preventing wall portion 15 when the diaper 1 is worn, and this makes it easy for the pair of leakage preventing wall portions 15 to maintain the raised state while maintaining the distance W15 without folding and deforming the leakage preventing wall portion 15. This makes the wearer less prone to discomfort and more prone to inhibit lateral leakage of fecal material.

Further, as shown in fig. 2, in the lateral direction, the one end portion 61es1 of the front low stretch region 61 is located on one side with respect to the one end portion 10es1 of the absorbent main body 10, and the other end portion 61es2 of the front low stretch region 61 is located on the other side with respect to the other end portion 10es2 of the absorbent main body 10. That is, in the front waist portion 30, the width W61 in the lateral direction of the front low stretch region 61 is larger than the width W10 in the lateral direction of the absorbent main body 10 (W61 > W10). The two end portions 10es1 and 10es2 in the transverse direction of the absorbent main body 10 respectively form a part of the corresponding leg openings LH of the diaper 1 and are easily pressed against the groin of the wearer. Therefore, in the case where the waist elastic member 35 is arranged to overlap with the both end portions 10es1 and 10es2 in the lateral direction of the absorbent main body 10, the waist elastic member 35 is liable to be pressed against the skin in the vicinity of the wearer's leg, with the risk of being liable to form rubber marks. In contrast, in the diaper 1 of the present embodiment, the contraction force generated by the waist elastic member 35 is less likely to act on both end portions 10es1 and 10es2 in the transverse direction of the absorbent main body 10 and the regions outside thereof, and thus is less likely to form rubber marks in the regions around the legs of the wearer.

However, the extent in the lateral direction of the front low-stretchability region 61 may be modified as follows. Fig. 9 is a schematic diagram showing a modified example of the front low-scalability region 61. Fig. 9 is a schematic view corresponding to fig. 2, showing the diaper 1 in a state of maximum extension when it is unfolded. In the modified example in fig. 9, in the lateral direction, the end portion 61es1 on one side of the front low stretch region 61 is located on the other side with respect to the end portion 10es1 on one side of the absorbent main body 10, and is located on one side with respect to the end portion 11es1 on one side of the absorbent core 11. The other end portion 61es2 of the front low stretch region 61 is located on one side with respect to the other end portion 10es2 of the absorbent main body 10 and on the other side with respect to the other end portion 11es1 of the absorbent core 11. In this case, some of the front waist elastic members 35 are arranged to overlap with both end portions in the lateral direction of the absorbent main body 10, and therefore, in the overlapped portion, the absorbent main body 10 is pressed against the skin of the wearer due to the contraction force generated by the front waist elastic members 35. This makes it less likely to leave rubber marks around the legs of the wearer, while the fit of the absorbent main body 10 can be enhanced.

Subsequently, in a region in the lateral direction between the outer side end 10es (e.g., the end 10es2 on the other side in the lateral direction) and the side joining portion 50 (the side joining portion 50 on the other side in the lateral direction) of the absorbent main body 10 in fig. 2, it is desirable that the width W61s in the lateral direction of the front low stretch region 61 is narrower than the width W62s of the front first stretch region 62 adjacent to and outside the front low stretch region 61 in the lateral direction (W61 s < W62 s). In the front waist portion 30, the front low stretch region 61 is provided to be wider, which makes the contraction force weak as a whole, and there is a risk of insufficient fitting of the front side of the wearer. Therefore, in the regions located on both sides in the lateral direction of the front low stretch region 61, the front first stretch region 62 is made larger than the front low stretch region 61, which makes the contractive force of the waist elastic member 35 liable to act. Therefore, it is possible to suppress deterioration of the fitting degree of the front waist portion 30 on the wearer's front side while making it less likely to leave rubber marks, as compared with the case where the front first stretch region 62 is narrower than the front low stretch region 61.

However, a configuration may be adopted in which the width W61s in the lateral direction of the front low-stretch region 61 is larger than the width W62s of the front first-stretch region 62 adjacent to the outside of the front low-stretch region 61 in the lateral direction (W61 s > W62 s). According to the above configuration, since the contraction force acting on the front waist portion 30 is smaller than in the above case, the absorbent main body 10 can be made less prone to contract. Further, the range in which the contraction force generated by the waist elastic member 35 is less likely to act becomes larger on both sides in the lateral direction of the absorbent main body 10, and thus it is possible to make it less likely that rubber marks are formed in the skin around the leg portions on the wearer's front side.

Further, as shown in fig. 2, it is desirable that the length H61 in the vertical direction of the front low-elasticity region 61 is longer than the length H63 in the vertical direction of the front second-elasticity region 63 adjacent to and above the front low-elasticity region 61 (H61 > H63). In other words, in the front waist portion 30, the length in the vertical direction of the portion where the front low-stretchability region 61 is desirably formed (corresponding to H61) is longer than the length in the vertical direction of the portion where the front low-stretchability region 61 is not formed (corresponding to H63). Therefore, in a larger range in the vertical direction of the front waist portion 30, the contraction force in the lateral direction caused by the waist elastic member 35 is weakened, the absorbent core 11 is less likely to contract, and rubber marks are less likely to be formed on the skin of the wearer.

On the other hand, contrary to the case shown in fig. 2, the length H61 in the vertical direction of the front low-stretchability region 61 may be equal to or smaller than the length H63 in the vertical direction of the front second-stretchability region 63 (h61+.h63). In other words, in the front waist portion 30, the length in the vertical direction of the portion where the front low-stretchability region 61 is formed (corresponding to H61) may be equal to or smaller than the length in the vertical direction of the portion where the front low-stretchability region 61 is not formed (corresponding to H63). With the above-described configuration, the contraction force of the waist elastic member 35 acting on the front waist portion 30 can be increased as compared with the case where the length H61 is greater than the length H63. For example, in the case where the diaper is large in size or it is desired to prevent deterioration of fit around the waist of the wearer, it is desired that the front waist portion 30 have a certain strength of stretchability. Therefore, in this case, by adjusting the length to satisfy H61 Σ63, the positional deviation and the deterioration of the fit when wearing the diaper 1 can be suppressed.

Other embodiments

Although the embodiments of the present invention have been described above, the above-described embodiments are merely for the convenience of understanding the present invention and are not intended to limit the explanation of the present invention. Further, the present invention may be modified or improved within the scope of the gist of the present invention, and needless to say, equivalents thereof are also included in the present invention.

In the diaper 1, the areas of the front waist portion 30 and the rear waist portion 40 may be adjusted such that the area ratio of the front waist portion 30 and the rear waist portion 40 is within a predetermined range. For example, in the case where the area of the front waist portion 30 is between 30 and 50, the area of the rear waist portion 40 is desirably between 50 and 70, and more desirably the area ratio of the front waist portion 30 and the rear waist portion 40 is 35:65. By making the area of the rear waist portion 40 larger than the area of the front waist portion 30, the contraction pressure can be reduced even in the case where the stress in the rear waist portion 40 is large, so that discomfort to the wearer is less likely to be caused.

In the above-described embodiments, such examples are described: in the waist portion 20 of the diaper 1, since the rear waist portion 40 is contracted to a greater extent in the transverse direction (waistline direction) than the front waist portion 30, the side joint portions 50 and 50 are displaced to the rear side in the front-rear direction (see fig. 5 and the like). However, a structure may also be adopted in which the front waist portion 30 contracts to a greater extent than the rear waist portion 40, and the side joint portions 50 and 50 are displaced to the front side in the front-rear direction. In this case, it is desirable that the width in the lateral direction of the rear low-stretch region 71 is larger than the width in the lateral direction of the front low-stretch region 61. With this configuration, the same effect as that obtained on the front side in the above-described embodiment can be obtained on the rear side.

List of reference numerals

1 a diaper (underpants-shaped disposable diaper),

2 diapers (underpants-type disposable diapers) (comparative examples),

an absorbent body is provided at 10 which,

11, 11b comprises a core sheet,

a 12-top sheet, a top sheet,

13 back sheet, 13a liquid impermeable sheet, 13b outer sheet,

15 leakage preventing wall parts, 16 leakage preventing wall elastic parts, 17 leg elastic parts,

a 20-waist portion,

23, 24,

30 front waist portion, 30sw side portions, 31 skin side panels,

32 non-skin side panels, 32f folded back portions,

35 waist elastic member (front waist elastic member),

35s continuous elastic members, 35c discontinuous elastic members,

36. the surface-area sheet of the skin,

40. a rear waist portion of the waist portion,

40b buttock cover, 40sw side portions,

41 skin side panels, 42 non-skin side panels, 42f folded back portions,

45 waist elastic (rear waist elastic),

45s continuous elastic members, 45c discontinuous elastic members,

50 a side engagement portion,

61 a front low-stretch zone (discontinuous portion),

62 front first region of stretchability, 63 front second region of stretchability,

71 a rear low-stretchability region (discontinuous portion),

81 rear first region of stretchability, 82 rear second region of stretchability,

A 100-degree tensile testing machine,

a 110 chuck is provided with a plurality of clamping heads,

120A, 120B,

BH waist opening, LH leg opening

CL center position (longitudinal direction, length direction)

Claims

1. A pant-like disposable diaper having a vertical direction, a lateral direction, and a front-rear direction intersecting each other, comprising:

an absorbent body comprising a liquid-absorbent core; and

a waist portion capable of stretching and contracting in a lateral direction,

the maximum stretching state is a stretching state of the waist portion when the waist portion is stretched in the transverse direction until the waist portion reaches the size of the sheet-like member itself constituting the waist portion, and when the waist portion is stretched in the transverse direction until the waist portion reaches 70% of the size of the sheet-like member itself, the waist portion has an area in the maximum stretching state in at least a part of a portion located outside the absorbent core in the transverse direction.

2. The pant-like disposable diaper according to claim 1, wherein,

the waist portion has a front waist portion and a rear waist portion, and

When the waist portion is stretched in the transverse direction until the waist portion reaches 70% of the size of the sheet-like member itself, the front waist portion has an area in a maximum stretched state in at least a part of a portion located outside the absorbent core in the transverse direction.

3. The pant-like disposable diaper according to claim 1 or 2, wherein,

the waist portion has a front waist portion and a rear waist portion, and

when the waist portion is stretched in the transverse direction until the size of the waist portion reaches 70% of the size of the sheet-like member itself, the rear waist portion has an area in a maximum stretched state in at least a part of a portion located outside the absorbent core in the transverse direction.

4. The pant-like disposable diaper according to claim 3, wherein,

the rear waist portion includes: a skin side panel; and a non-skin side sheet covering the non-skin side of the skin side sheet, and

at least a part of the region of the non-skin side sheet in the maximum stretched state is provided with a through hole penetrating the non-skin side sheet in the thickness direction.

5. The pant-like disposable diaper according to any of claims 1 to 4, wherein,

On each of both sides in the transverse direction of the region in the maximum stretched state in the waist portion, there is provided a stretchable region that stretches and contracts in the transverse direction.

6. The pant-like disposable diaper according to any of claims 1 to 5, wherein,

the waist portion has a front waist portion and a rear waist portion, and

in the case where the width in the lateral direction of the region in the maximum stretched state of any one of the front and rear waist portions is larger than the width in the lateral direction of the region in the maximum stretched state of the other waist portion, the contraction force in the lateral direction of the other waist portion is larger than the contraction force in the lateral direction of the one waist portion.

7. The pant-like disposable diaper according to any of claims 1 to 6, wherein,

the waist portion has a skin side sheet and a non-skin side sheet overlapped in the thickness direction, and

in at least a part of a portion located outside the absorbent core in the transverse direction, the waist portion has a non-joined portion in a region in a maximum stretched state, the non-joined portion being a portion in which the skin side sheet and the non-skin side sheet are not joined to each other.

8. The pant-like disposable diaper according to claim 7, wherein,

the pant-like disposable diaper further includes a main body engagement portion which engages the waist portion on the non-skin side of the absorbent main body, and

in the region overlapping the main body joint portion when seen in the thickness direction, the tensile strength of the skin-side sheet in the maximum tensile state and further stretched 5% in the vertical direction is greater than the tensile strength of the non-skin-side sheet in the maximum tensile state and further stretched 5% in the vertical direction.

9. The pant-like disposable diaper according to any of claims 1 to 8, wherein,

the waist portion has a front waist portion and a rear waist portion,

a pair of side joint portions provided in both ends in the lateral direction, the pair of side joint portions annularly connecting the front waist portion and the rear waist portion, and

at a specific position in the vertical direction, the shortest distance from any one side joint portion to the other side joint portion along the surface of the front waist portion is longer than the shortest distance from the any one side joint portion to the other side joint portion along the surface of the rear waist portion.

10. The pant-like disposable diaper according to any of claims 1 to 9, wherein,

the waist portion has a front waist portion and a rear waist portion,

the front waist portion has a front low-extensibility region in which extensibility is reduced as compared to other regions,

the rear waist portion has a rear first stretchable region which is a region overlapping with the front low stretchable region with respect to a vertical direction and a rear second stretchable region which is a region adjacent to and above the rear first stretchable region, and

the contraction force in the lateral direction acting on the region having a unit length in the vertical direction in the rear first stretchable region is larger than the contraction force in the lateral direction acting on the region having a unit length in the vertical direction in the rear second stretchable region.

11. The pant-like disposable diaper according to claim 10, wherein,

the front waist portion has a front first stretchability region which is a region overlapping the front low stretchability region with respect to the vertical direction and is adjacent to both sides in the lateral direction of the front low stretchability region,

The contraction force in the lateral direction acting on the region having a unit length in the vertical direction in the rear first stretchable region is larger than the contraction force in the lateral direction acting on the region having a unit length in the vertical direction in the front low stretchable region and the front first stretchable region.

12. The pant-like disposable diaper according to claim 10 or 11, wherein,

the front waist portion has a front first stretchability region which is a region overlapping the front low stretchability region with respect to the vertical direction and adjacent to both sides in the lateral direction of the front low stretchability region, and a front second stretchability region which is a region adjacent to and above the front low stretchability region and the front first stretchability region in the vertical direction,

each of the front first stretchable region and the front second stretchable region is provided with a plurality of linear elastic elements, and

the spacing in the vertical direction of the linear elastic elements arranged in the front second region of extensibility is greater than the spacing in the vertical direction of the linear elastic elements arranged in the front first region of extensibility.

13. The pant-like disposable diaper according to any of claims 10 to 12, wherein,

each of the rear first stretchable region and the rear second stretchable region is provided with a plurality of linear elastic members, and

the spacing in the vertical direction of the linear elastic members disposed in the rear second stretchable region is larger than the spacing in the vertical direction of the linear elastic members disposed in the rear first stretchable region.