CN107106376B

CN107106376B - Disposable diaper having a disposable diaper

Info

Publication number: CN107106376B
Application number: CN201580071171.6A
Authority: CN
Inventors: 卫藤友美; 中嶋海阳; 田中嘉则
Original assignee: Unicharm Corp
Current assignee: Unicharm Corp
Priority date: 2014-12-26
Filing date: 2015-12-25
Publication date: 2020-09-08
Anticipated expiration: 2035-12-25
Also published as: JPWO2016104753A1; WO2016104753A1; JP6479049B2; CN107106376A; KR102520783B1; KR20170098230A

Abstract

Provided is a disposable diaper provided with a side flap which can improve the bonding strength with a waist belt and has a good skin feel. A disposable diaper (10) is provided with: a diaper main body (16) and a pair of waist belts (17) for connecting front and rear waist regions (11, 12), wherein the pair of waist belts (17) are joined to the diaper main body (16) by joining lines (18A, 18B) that are closer to a longitudinal center line (P) from a leg opening (15) side toward a waist opening (14) side, the diaper main body (16) has side flaps (40) that extend in a longitudinal direction (Y) outside a transverse direction (X) at both side edge portions of an absorber (23), the side flaps (40) have high-rigidity regions (41) having higher rigidity than other regions at edge portions extending along the leg openings (15), and both end portions (41A, 41B) of the high-rigidity regions (41) are located at the joining lines (18A, 18B).

Description

Disposable diaper having a disposable diaper

Technical Field

The present invention relates to a disposable diaper.

Background

Conventionally, there is known a disposable diaper including: a diaper main body having an absorber, the diaper main body having a front waist region, a rear waist region, and a crotch region located between the front waist region and the rear waist region; a pair of waist belts for connecting the front waist region and the rear waist region; the waist is opened; and a pair of leg openings. For example, in a disposable diaper disclosed in patent document 1, a pair of waist belts are joined to a diaper main body via a joining line that is closer to a longitudinal centerline from a leg opening side toward a waist opening side, and a pair of side flaps are formed on the diaper main body laterally outward of an absorbent body. The side flaps are formed of a plurality of sheet members stacked together, and have substantially uniform rigidity as a whole. The side flaps are joined to the waist band by means of joining lines, forming leg openings together with the waist band.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 9-10261

Disclosure of Invention

Problems to be solved by the invention

The diaper described in patent document 1 can give the wearer an impression of underwear, as compared with a diaper in which the front and rear waist regions are formed by an endless waist belt and a diaper in which the front and rear waist regions and the crotch region are formed by an integrated sheet member.

However, in the diaper described in patent document 1, when the joining strength at the joining portion between the waist band and the side flap is relatively low when the diaper is pulled up by holding the waist band, the side flap is likely to be broken in the vicinity of the end portion on the leg portion opening side of the joining line. On the other hand, if the rigidity of the entire side flap is increased in order to increase the joining strength, the flexibility of the side flap is impaired, and the skin feel is deteriorated.

The invention aims to provide a disposable diaper which is an improvement of the prior art and is provided with a side flap which can improve the bonding strength with a waist belt and has good skin touch.

Means for solving the problems

A disposable diaper of the present invention has a longitudinal direction and a transverse direction, and a longitudinal centerline that bisects the dimension in the transverse direction, and includes: a diaper main body having an absorber, the diaper main body having a front waist region, a rear waist region, and a crotch region located between the front waist region and the rear waist region; a pair of waist belts for connecting the front waist region and the rear waist region; the waist is opened; and a pair of leg openings.

In the diaper of the present invention, the pair of waist belts are joined to the diaper main body at joining lines which are spaced from each other from the leg opening side toward the waist opening side in the front waist region and the rear waist region, the diaper main body has side flaps extending in the longitudinal direction outside the lateral direction at both side edge portions of the absorbent body, the side flaps have high-rigidity regions having higher rigidity than other regions at edge portions extending along the leg openings, and both end portions of the high-rigidity regions are located on the joining lines.

The diaper body includes: a liquid permeable inner layer sheet; a liquid impermeable outer sheet; the absorber is positioned between the inner layer sheet and the outer layer sheet; and a pair of side sheets disposed on both sides of the absorbent body, wherein the high-rigidity region is formed by disposing separate elastic sheets on the side sheets, so that the side sheets are bonded to the body in a planar manner without gaps at leg opening edges, thereby preventing the leakage of excrement.

The side sheet has a 1 st sheet located on the skin-facing surface side and a 2 nd sheet located on the non-skin-facing surface side, and the elastic sheet is located between the 1 st and 2 nd sheets, so that both side edge portions of the elastic sheet are not exposed to the outside and are not peeled off or do not make contact with the skin and give a sense of incongruity.

The elastic sheet is disposed on at least one of the skin-facing surface side and the non-skin-facing surface side of the side sheet, and therefore elasticity can be imparted to the non-elastic side sheet.

Since the plurality of leg elastic bodies extending in the longitudinal direction are arranged in the high rigidity region, the fit at the leg opening edge portion can be improved together with the elastic sheet.

The leg elastic bodies are disposed between the laminated sheet members in the high rigidity region, and the plurality of waist elastic bodies are disposed in the waist band, and the leg elastic bodies and the waist elastic bodies do not overlap each other in the thickness direction of the sheet members.

Since the width dimension of the high rigidity region is 3mm to 30mm, the leg opening edge portion can be attached to the thigh of the wearer in a planar manner.

ADVANTAGEOUS EFFECTS OF INVENTION

According to one or more embodiments of the disposable diaper of the present invention, the side flap has a high rigidity region having higher rigidity than the rigidity of the other region at the edge portion extending along the leg opening, and both ends of the high rigidity region are located on the join line, so that the joining strength between the waist band and the side flap is increased at the end portion on the leg opening side of the join line, and the side flap can be prevented from being damaged. In addition, in the side flap, since the high-rigidity region is located at the edge of the side flap forming the leg opening and the rigidity of the other region is relatively low, the flexibility of the side flap can be maintained and the skin feel can be improved.

Drawings

Fig. 1 is a perspective view of a diaper showing an example of a disposable diaper according to embodiment 1 of the present invention.

Fig. 2 is a plan view of a diaper extended in the longitudinal and transverse directions and in a state in which the inner surface of the waist belt and the inner surface of the diaper main body are in contact with each other.

Fig. 3 is an expanded plan view of the diaper in which the joining line between the front and rear waist regions of the diaper is released and the diaper main body and the waist belt are extended in the longitudinal and lateral directions.

Fig. 4 is a sectional view taken along line IV-IV of fig. 2.

Fig. 5 is an enlarged view of the area surrounded by the V line of fig. 4.

Fig. 6 (a) is a partially enlarged view of the region surrounded by the line v (a) of fig. 3. Fig. 6 (b) is a partially enlarged view of the region surrounded by the line v (b) of fig. 3.

Fig. 7 is a front view of the diaper in a contracted state in which the inner surface of the front waist region and the inner surface of the rear waist region are in contact with each other.

Fig. 8 is a front view of the diaper showing the worn state.

Figure 9 is a side view of the diaper in a worn state.

Fig. 10 is a cross-sectional view of the diaper 10 similar to fig. 5, which is an example of a modification.

Detailed Description

The embodiments described below relate to a disposable diaper shown in fig. 1 to 10 as an example of the present invention, and include not only an indispensable configuration of the invention but also an alternative and preferable configuration. In fig. 2 to 4, each elastic body discussed later is in the following state: the member having the elastic bodies attached thereto is stretched against the contraction force thereof to such an extent that the gathers of the member having the elastic bodies attached thereto due to the contraction force in the lateral direction X and the longitudinal direction Y appear to be substantially disappeared by natural vision.

Referring to fig. 1 to 3, a diaper 10 as an example of a disposable diaper of the present invention includes: a longitudinal direction Y and a transverse direction X orthogonal to the longitudinal direction Y; a non-skin-facing surface opposite to the skin-facing surface; a longitudinal center line P for bisecting the length dimension of the transverse direction X; and a transverse center line Q bisecting the length dimension in the longitudinal direction Y, including a front waist region 11, a rear waist region 12, and a crotch region 13 located between the front waist region 11 and the rear waist region 12. The diaper 10 is generally symmetrical about a longitudinal centerline P and has a waist opening 14 and a pair of leg openings 15.

The diaper 10 includes: a diaper main body 16 having an absorber 23 extending in the longitudinal direction Y; and a pair of waist belts 17 for connecting the front waist region 11 and the rear waist region 12. The pair of waist belts 17 are disposed substantially symmetrically with respect to the longitudinal centerline P, and are joined to the diaper main body 16 by joining lines (seal lines) 18A, 18B formed of a plurality of independent seal portions, which are located closer to the longitudinal centerline P from the leg openings 15 side toward the waist opening 14 side. The sealing portion is formed by a known bonding means, for example, various thermal bonding means such as hot embossing and sonic processing. At the

joining lines

18A, 18B, the skin-facing surface of the waist belt 17 and the skin-facing surface of the diaper main body 16 are fixed to each other. By having this joining form, the

joining lines

18A, 18B do not contact the body of the wearer and cause discomfort or irritation. As long as the effects of the present embodiment described later are obtained, the

bonding wires

18A and 18B can use a known bonding means such as a hot-melt adhesive, in addition to a thermal bonding means. The waist belt 17 is formed of a pair of elastic sheets (japanese: パネル), but may be formed of the same sheet material as the diaper main body 16 by a manufacturing method described later.

< diaper Main body >

Referring to fig. 3 to 5, the diaper main body 16 is defined by a front end edge 16a and a rear end edge 16b which are separated and opposed in the longitudinal direction Y and both

side edges

16c, 16d which are separated and opposed in the lateral direction X, and the diaper main body 16 includes: a front end portion 20A located between the front edges 16 a; a rear end portion 20B located between the rear edges 16B; and an intermediate portion 20C located between the front end portion 20A and the rear end portion 20B. The front end edge 16a and the rear end edge 16b are substantially symmetrical with respect to the longitudinal center line P and extend in a convex shape outward in the longitudinal direction Y. The front end portion 20A is located in the front waist region 11 of the diaper 10, the rear end portion 20B is located in the rear waist region 12 of the diaper 10, and the intermediate portion 20C is located in the crotch region 13.

The diaper main body 16 includes: a liquid-permeable inner sheet 21 positioned on the skin-facing surface; a liquid-impermeable outer sheet 22 positioned on the non-skin-facing surface; an absorber 23 positioned between the inner sheet 21 and the outer sheet 22; and a liquid-impermeable or liquid-impermeable leakage-preventive sheet 24 positioned between the absorbent body 23 and the outer sheet 22. A pair of side sheets 25 are disposed on both sides of the inner layer sheet 21 and the outer layer sheet 22, and the pair of side sheets 25 are spaced apart from each other in the transverse direction X and extend in the longitudinal direction Y in a state of being interposed between the inner layer sheet 21 and the outer layer sheet 22. The diaper main body 16 further includes side flaps 40 each including a portion of the side panel 25 extending outward in the lateral direction X from both side edges of the inner sheet 21, the outer sheet 22, and the leakproof sheet 24 (i.e., a region excluding the inner sheet 21, the outer sheet 22, and the leakproof sheet 24 on the lateral outer side of the absorbent body 23).

The inner layer sheet 21 has a generally octagonal shape, preferably having a mass of about 15g/m²～35g/m²Preferably about 18g/m²～24g/m²The hydrophilic-treated hydrophobic through-air fiber nonwoven fabric, spunbond fiber nonwoven fabric, point-bonded fiber nonwoven fabric, and the like. Outer coverThe sheet 22 and the inner sheet 21 have substantially the same shape and the same size, and have a mass of about 15g/m²～30g/m²Preferably about 18g/m²～24g/m²The hydrophobic spunbond/hot melt/spunbond (hereinafter referred to as SMS) fiber nonwoven fabric or spunbond fiber nonwoven fabric.

The absorbent body 23 has a front end edge 23a and a rear end edge 23b which are curved convexly outward in the longitudinal direction Y, and both side edges 23c extending along the longitudinal direction Y between the front end edge and the rear end edge, and includes a liquid-absorbent core shaped into a desired shape and a liquid-diffusing core covering sheet such as tissue paper which covers the liquid-absorbent core. As the liquid-absorbent core, wood fluff pulp, superabsorbent polymer particles, or a mixture thereof can be used. The liquid-absorbent core and the core covering sheet can be joined to each other by a known joining means such as a hot melt adhesive.

The leakproof sheet 24 is disposed so as to cover at least the entire non-skin-facing surface (bottom surface) of the absorbent body 23, and can be joined between the absorbent body 23 and the outer sheet 22 by a known joining means such as a hot melt adhesive. The leakproof sheet 24 can be, for example, a liquid-impermeable, preferably liquid-impermeable and air-permeable plastic film, and the leakproof sheet 24 covers the entire non-skin-facing surface of the absorbent body 23, thereby preventing body fluid absorbed by the absorbent body 23 from leaking to the outside of the diaper 10. Although not shown, the leakproof sheet 24 may be formed of a sheet having decorative elements such as patterns and colors, and the decorative elements may be made to transmit through the outer sheet 22 having a desired light transmittance.

Referring to fig. 4 and 5, the pair of side sheets 25 are disposed on both sides of the absorber 23 in the transverse direction X, and are joined between the leakproof sheet 24 and the inner sheet 21 by a known joining means such as a hot melt adhesive. The side sheet 25 is formed of a 1 st sheet 25A located on the absorbent body 23 side and a 2 nd sheet 25B located on the outer sheet 22 side, and the two

sheets

25A and 25B are joined by a known means such as a hot melt adhesive. As the side sheet 25, for example, a sheet having a mass of about 10g/m can be used²～30g/m²A hydrophobic SMS fiber nonwoven fabric or a spunbond fiber nonwoven fabric.

Between the outer edge of the 1 st sheet 25A and the outer edge of the 2 nd sheet 25B, a plurality of leg elastic members 26 extending in the longitudinal direction and leg elastic members 27 located on the skin-facing surface side of the leg elastic members 26 are arranged. The side panel 40 has a high rigidity region 41 in which the leg elastic sheet 27 is disposed, and a low rigidity region 42 formed only by the side sheet 25 and located on the inner side in the transverse direction X of the high rigidity region 41. The high rigidity region 41 has a higher rigidity than the low rigidity region 42 because the number of stacked sheets is larger than that of the low rigidity region 42. In order to form a region having higher rigidity than the low rigidity region 42 along the leg opening edge portion, a portion formed by bending the side sheet 25 may be formed in the region instead of the leg elastic sheet 27 or in addition to the leg elastic sheet 27, or an inelastic auxiliary sheet may be disposed.

The leg elastic members 26 are formed of a plurality of thread-like or strand-like elastic members that are attached so as to be contractible in an extended state along the longitudinal direction Y between the front end edge 16a and the rear end edge 16b of the diaper main body 16. The leg elastic sheet 27 is a belt-like elastic member attached to the diaper main body 16 so as to be stretchable in the longitudinal direction Y from the front end edge 16a to the rear end edge 16b, and is formed of a flat rubber belt or an elastically stretchable fiber nonwoven fabric made of elastic fibers. By disposing the leg elastic members 26 and the leg elastic pieces 27 on both side portions of the diaper body 16, leg elastic regions (the same regions as the high stiffness regions 41) are formed on the outer portions of both side edges 23c of the absorbent member 23 in the lateral direction X. Referring to fig. 3, since the leg elastic sheets 27 extend from the front end edge 16a to the rear end edge 16B of the diaper body 16, both ends of the high rigidity region 41, that is, both ends 41A, 41B in the longitudinal direction Y are positioned at the

join lines

18A, 18B. In the present embodiment, the side sheet 25 is formed of two

sheets

25A and 25B, but may be formed by bending and fixing a single fiber nonwoven fabric, or may be formed of an extended portion of the outer sheet 22. The leg elastic sheet 27 may be disposed on the skin-facing surface side or the non-skin-facing surface side of the side sheet 25, but as in the present embodiment, by being disposed between the 1 st sheet 25A and the 2 nd sheet 25B, it is possible to prevent the side edge portion from being exposed to the outside and being peeled therefrom, and to reduce the discomfort caused by the side edge portion directly contacting the skin.

< waist Belt >

Referring to fig. 2 and 3, the waist belt 17 has both end edges (front end edge, rear end edge) 17a, 17B joined to the diaper main body 16 by joining

lines

18A, 18B, a lower side edge 17c forming the leg opening 15 together with both

side edges

16c, 16d of the diaper main body 16, and an upper side edge 17d forming the waist opening edge. The waist belt 17 is divided into an upper portion 51 located on the waist opening side (1 st side edge side) and a lower portion 52 located on the leg opening side (2 nd side edge side). The width-directional dimensions of the upper and lower portions are about 30% to 70%, and preferably have a magnitude of 50%, of the width dimension W1 of the waist belt 17, respectively. Thus, for example, in the case of the M size of a typical adult diaper, the width dimension W1 of the waist belt 17 is about 70mm, and the width dimensions of the upper and

lower portions

51, 52 are about 35 mm.

The waist belt 17 has an inner layer 31 and an outer layer 32 formed of a waist panel 30 made of a fibrous nonwoven fabric. A plurality of waist

elastic members

33, 34 made of a string-like or strand-like elastic material are attached between the inner layer 31 and the outer layer 32 so as to be contractible in an extended state. The waist

elastic bodies

33, 34 include an upper waist elastic body 33 disposed in the upper portion 51 and a lower waist elastic body 34 disposed in the lower portion 52.

A waist elastic sheet 35 formed of an elastic fiber nonwoven fabric is disposed on the lower side edge 17c side of the waist sheet 30. The waist elastic sheet 35 is disposed so that a part thereof overlaps the lowermost lower waist elastic body 34. Further, a part of the waist panel 30 is folded inward at the upper side edge 17d side, and the folded state is fixed. A plurality of upper waist elastic members 33 are disposed at the bent portions 36. In addition, it is preferable that the upper waist elastic body 33 disposed in the bent portion 36 and the upper waist elastic body 33 disposed in the body portion other than the bent portion 36 in the waist panel 30 are offset in the thickness direction. This avoids concentration of extension stress caused by overlapping of the upper waist elastic body 33 in the thickness direction, and can achieve fit to the body over a wide range. Further, since the bent portion 36 is located at the waist opening edge portion, the light transmittance is locally lowered, and the underwear-like appearance is obtained like pants.

In the present embodiment, 10 upper waist elastic bodies 33 are disposed in the upper portion 51 of the waist belt 17, and 6 upper waist elastic bodies 33 (including elastic bodies disposed in the bent portions 36) disposed on the side of the waist opening have a thickness of 450dtex to 500dtex and are fixed in a state of being extended by 3.0 to 3.5 times. The 4 elastic members of the upper waist elastic member 33 disposed on the leg opening side have a thickness of 600dtex to 650dtex and are fixed in a state of being stretched 2.5 times to 3.0 times. 7 lower waist elastic bodies 34 are arranged in the lower portion 52, and the lower waist elastic bodies 34 are fixed in a state of being stretched 2.5 to 3.0 times, with a thickness of 600dtex to 650 dtex. The interval (separation dimension) between the upper waist elastic body 33 and the lower waist elastic body 34 is equal, and is 5.0mm to 6.0 mm.

In the waist belt 17, since the lower waist elastic member 34 and the waist elastic sheet 35 are disposed in the lower portion 52, the extension stress per unit area in the lateral direction X of the lower portion 52 is higher than the extension stress per unit area in the lateral direction X of the upper portion 51. By thus making the elongation stress of the upper portion 51 relatively low, it becomes easy to expand the waist opening when worn. On the other hand, the lower portion 52 has a relatively high extension stress, and therefore can be stably fitted to the body of the wearer at the leg hole to exert a required holding force. In particular, when the diaper 10 is a so-called low-waist type diaper having a shallow rise and the width dimension of the waist belt 17 is smaller than the width dimension of the diaper main body and is likely to be displaced by movement of the wearer during wearing, the lower portion 52 is stably attached to the body, and the displacement thereof can be suppressed.

< method for measuring elongation stress >

The elongation stress of the upper portion 51 and the elongation stress of the lower portion 52 were measured by the following method using a tensile tester manufactured by instron japan ltd (japanese: インストロンジャパンカンパニーリミテッド). First, the absorbent body 23 is removed from the diaper 10, the regions forming the front waist region 11 and the rear waist region 12 extending in the girth direction are cut out to obtain a ring-shaped elastic sheet, the elastic sheet is cut at the center portion of the width dimension (the center portion in the longitudinal direction Y) with a cut line extending in the girth direction to obtain a ring-shaped sample 1 corresponding to the front waist region 11 and the upper portion 11A of the rear waist region 12 and a ring-shaped sample 2 corresponding to the lower portion 11B of the front waist region 11 and the rear waist region 12, and the dimensions (K1, K2) of the samples 1 and 2 in the contracted state are measured.

First, in the case of measuring the elongation stress of the sample 1, the separation distance between the upper and lower hooks of the tensile tester is adjusted to the length dimension K1 in the contracted state of the sample 1, and then one end of the sample 1 (a portion corresponding to the central portion 17f in the longitudinal direction of the waist belt 17 shown in fig. 7) is attached to the upper hook (anchor), and the other end of the sample 1 (a portion corresponding to the central portion 17e in the longitudinal direction of the waist belt 17 shown in fig. 7) is attached to the lower hook (movable element). Before the elongation, the distance between the hooks was finely adjusted so that the elongation stress became 0.1N. Thereafter, the tensile testing machine was set to a circulation mode, and the upper hook was moved at a tensile speed of 300 mm/min. For example, in the case where the dimension K1 at the time of contraction is 244mm for the sample 1 (upper portion), the operation of returning the sample 1 to the origin after further elongating it by 235mm is repeated twice, and the forward stress at the time point of the 2 nd elongation by 56mm and the backward stress at the time point of the 2 nd elongation by 181mm are measured to be the elongation stress of the sample 1. On the other hand, the elongation stress of sample 2 was also determined by the same measurement method as sample 1.

As a result of the measurement by the above-described measurement method, the relief stress of sample 1 was 1.082N, and the relief stress of sample 2 was 1.083N, which were all substantially the same in magnitude. Therefore, the extension stress when extending in the girth direction is substantially the same in the front waist region 11 and the rear waist region 12, and the whole of the front waist region 11 and the rear waist region 12 can be expanded with a relatively small force when worn. On the other hand, the return stress of sample 1 is 3.476N and the return stress of sample 2 is 4.557N. Therefore, the leg opening sides of the front and

rear waist regions

11 and 12 can be said to be closer to the body than the waist opening side in the worn state.

The lower waist elastic body 34 disposed in the lower portion 52 is attached at a lower extension ratio than the upper waist elastic body 33 disposed in the upper portion 51. Specifically, the difference between the extension ratio of the lower waist elastic body 34 and the extension ratio of the upper waist elastic body 33 is 0.5 times or less. Specifically, the extension ratio of the upper waist elastic body 33 is 3.2 to 3.7 times, and the extension ratio of the lower waist elastic body 34 is 2.7 to 3.2 times. By setting the extension ratio of the lower waist elastic body 34 to be relatively low in this manner, the contraction amount of the lower portion 52 is reduced as compared with the contraction amount of the upper portion 51, and the leg openings are not extremely reduced in the contracted state as compared with the extended state, and the feet can easily pass through the leg openings. Further, the leg openings are made larger by making the dimension in the contracted state of the leg opening edge portions larger than the state in which the waist elastic sheet 35 is not arranged, and setting the difference in the extension stress between the upper and

lower portions

51, 52 is realized not by adjusting the pitch and the number of the upper waist elastic body 33 and the lower waist elastic body 34 but by arranging the waist elastic sheet 35 in the lower portion 52, so that even in the case where the lower portion 52 has a relatively high extension stress, the lower portion 52 can be attached in a planar manner to the skin to suppress the skin from getting tangled.

The thickness of the lower waist elastic body 34 is preferably larger than the thickness of the upper waist elastic body 33. By setting the thickness of the lower waist elastic body 34 relatively large in this manner, a relatively large extension stress can be exerted at a low magnification, and the fit of the leg-opening edge portions can be achieved.

Referring to fig. 2 and 3, in the extended state in which the diaper 10 is developed by peeling the join line 18A, the length L3 of the upper edge 17d of the waist belt 17 is larger than the length L4 of the lower edge 17c, and is trapezoidal in shape. Specifically, for example, in a typical M-size diaper, the length dimension L5 of the upper edge 17d (the length dimension of the upper portion 51) of the waist belt 17 is 550mm to 600mm, the length dimension L6 of the lower edge 17c (the length dimension of the lower portion 52) is 300mm to 350mm, and the width dimension W1 is 60mm to 95 mm. In the contracted state of the waist belt 17, the length L6 of the lower portion 52 is smaller than the length L5 of the upper portion 51. The length L6 of the lower portion 52 is 50% to 80% of the length L5 of the upper portion 51 in the extended state and the contracted state of the waist belt 17.

Referring to fig. 6 (a) and 6 (B), the waist belt 17 is contractibly joined in an extended state to the front end portion 20A and the rear end portion 20B of the diaper main body 16 via joining

lines

18A and 18B so that the 1 st side edge 17c side is on the leg opening edge side and the 2 nd side edge 17d side is on the waist opening edge side. In the present embodiment, an angle θ 1, which is an angle between an imaginary line 62 orthogonal to the waist opening edge (extending parallel to the longitudinal center line P) and a boundary line 60 between the waist band 17 and the diaper main body 16, which forms the inner edge of the joint line 18A, and the waist opening edge, and an angle θ 2, which is an angle between an imaginary line 64 orthogonal to the waist opening edge and a boundary line 63 between the inner edge of the joint line 18B and the waist opening edge, are the same at an intersection point 61 between the boundary line and the waist opening edge. However, the angles θ 1 and θ 2 may be different from each other in size as needed, and in this case, the front side (ventral side) and the back side (back side) of the diaper 10 can be easily recognized when worn.

When the diaper 10 is worn, a force that a wearer or a wearing assistant grips the waist belt 17 and pulls it up and a force that the waist

elastic bodies

33 and 34 pull it in the girth direction are concentrated, and stress is concentrated at the intersection points 61 and 63 between the waist opening and the joining line 18A, and breakage is likely to occur. At the join line 18A, the plurality of sheets are joined and integrated by the heat-fusion means, not by the hot-melt adhesive, and therefore, the rigidity becomes relatively high, and even if this force is concentrated, breakage of the diaper 10 can be suppressed. In order to prevent breakage from the intersection points 61, 63, the bonding strength may be locally improved by increasing the bonding area of the

entire bonding wires

18A, 18B or the portion on the

intersection point

61, 63 side than the bonding area of the other portion, or a reinforcing sheet may be attached to the region including the portion to improve the sheet strength.

Referring to fig. 3, the dimension L2 in the longitudinal direction Y of the absorbent body 23 is about 65% to 95% of the dimension L1 in the longitudinal direction Y of the diaper 10 (diaper main body 16). In general, the dimension in the longitudinal direction of the absorbent body is about 60% of the dimension in the longitudinal direction of the diaper, and the area of the portion formed only by the sheet member located outside the absorbent body of the diaper in the longitudinal direction becomes relatively large. In the present embodiment, the absorbent body 23 has a length dimension that can sufficiently exhibit the required absorption performance, and the area of the portion located outside the absorbent body 23 in the longitudinal direction Y and formed only of the sheet member is relatively small, so that the absorbent body can be manufactured with less material, and the manufacturing cost can be suppressed. Further, since the front end edge 23a and the rear end edge 23b of the absorbent body 23 are closer to the front end edge 16a and the rear end edge 16b of the diaper main body 16 than in a normal diaper, the worn state is a low-waisted and simple wearing form in which the waist opening is positioned below the umbilical region.

Referring to fig. 7, the diaper 10 has a shape in which the entire waist opening is curved to be convex downward. That is, since the lateral center portions of the front and

rear waist regions

11, 12 are located below the both side portions thereof, a more compact impression can be obtained and the appearance is superior compared to a conventional diaper in which the longitudinal dimensions of the upper and lower regions are the same and the longitudinal dimension of the upper region is larger than the longitudinal dimension of the lower region.

Referring to fig. 8, when the waist belt 17 is pulled up while the diaper 10 is worn, stress concentrates at the

join lines

18A and 18B. In particular, at the end portion 45 on the leg-opening 15 side at the

join lines

18A, 18B, the 2 nd side edge 17B of the waist belt 17 is pulled upward relative to the position in the unworn state (the position of the 2 nd side edge 17B shown by the imaginary line in fig. 5), so that the tensile stress is increased, and breakage is likely to occur. In the diaper 10 of the present embodiment, since the both

end portions

41A, 41B of the high rigidity region 41 extend to the end portion 45 of the

join lines

18A, 18B, the number of sheets stacked at the end portion 45 is larger than that of the low rigidity region 42 (see fig. 6), and the joint strength at the seal portion is increased. Thus, even when stress is concentrated on the end portion 45 of the joining

line

18A, 18B, the side flap 40 can be effectively prevented from being damaged at the end portion 45 and the vicinity thereof. In addition, in the side flap 40, the low rigidity region 42 having flexibility is positioned inside the high rigidity region 41, and therefore, the skin feel can be improved.

Referring again to fig. 5, in consideration of the balance between the adhesiveness of the high rigidity region 41 and the skin touch of the low rigidity region 42, the width W2 of the high rigidity region 41 is preferably in the range of about 3mm to 30mm, and more preferably in the range of about 5mm to 15 mm. In addition, the leg elastic bodies 26 and the lower waist elastic body 34 are arranged so as not to overlap each other in the thickness direction Z. This can suppress the concentration of the tensile force generated by the

elastic bodies

26 and 34 at one point on the

join lines

18A and 18B (see the enlarged view in fig. 8), and thus make it more difficult for the diaper to be broken. In addition, in the plan view shown in fig. 2, a part of the leg elastic members 26 is positioned further outward in the lateral direction X than the lower waist elastic member 34, and the leakage of excrement from the leg opening edge portions can be effectively prevented.

As described above, in the diaper 10, the edge portion of the bent portion 36 on the side of the waist opening 14 forms a high waist stiffness region in which the portion where the bent portion 36 is located has higher stiffness than the other portions of the waist belt 17, similarly to the leg openings 15. Therefore, when the diaper 10 is worn, fingers can be hooked to the boundary portion between the high-rigidity waist region and the region adjacent thereto and having relatively low rigidity, and the diaper 10 can be pulled up. The boundary portion is easily bent due to the difference in rigidity, and the high rigidity waist region is more convex than the adjacent portion, so that the finger is easily hooked on the convex portion, and the pull-up operation is easily performed. Further, since the waist high rigidity region extends to the joining

lines

18A, 18B of the front and

rear waist regions

11, 12, the number of sheets stacked at the end portions of the joining

lines

18A, 18B on the side of the waist opening 14 increases, so that the joining strength increases, and the occurrence of breakage from the end portions can be prevented.

The diaper 10 of the present embodiment can give an impression like underwear as compared with a diaper having front and rear waist regions formed by an endless waist belt, and is suitable as a low waist type (low waist type) having a relatively shallow rise which is preferred as light incontinence for adults. When the diaper 10 is used as a diaper for incontinence, it is preferable that the thickness dimension of the absorbent body 23 is made relatively small and no leakage preventing flaps rising toward the wearer are formed on the skin-facing surface side of the absorbent body 23. In order to give an impression like underwear and to improve flexibility, the number of sheet members to be stacked in the low rigidity region 42 is preferably two or less, more preferably one. On the other hand, two or more (preferably 2 to 3) sheet members are stacked in the high rigidity region 41, and an elastic material (for example, a leg elastic body) is preferably arranged.

Referring to fig. 9, the waist elastic sheet 35 gradually becomes narrower in the upper portion 51 of the leg opening 15 from the both

end portions

35A, 35B on the joining

lines

18A, 18B side toward the central portion 35C in the girth direction, and becomes narrowest in the central portion (narrowest portion) 35C. Similarly, the leg elastic sheets 27 are gradually narrowed from the both

end portions

27A and 27B located on the joining

lines

18A and 18B toward the central portion (narrowest portion) 27C in the girth direction, and are also narrowest in the central portion 27C. By providing the waist elastic sheet 35 and the leg elastic sheets 27 with such shapes, the root portions of the thighs most likely to generate gaps with the diaper 10 in the body of the wearer are stably fitted to the both

end portions

27A, 27B, 35A, 35B of the two sheets located on the side of the

join lines

18A, 18B, and the

central portions

27C, 35C are brought into contact with the vicinities of the waistline bones and the outer portions of the thighs which are the least moving in the body, whereby material costs can be suppressed and appropriate fit to the body can be achieved as compared with a case where the entire elastic sheets are formed with the same width dimension. Further, since the wide region can be positioned on the hip side by slightly displacing the narrowest portion 35C of the waist elastic sheet 35 and the narrowest portion 27C of the leg elastic sheet 27 to the front side with respect to the central portions of the respective longitudinal dimensions, the front portions of the leg openings are larger than the rear portions and are closer to the line of the leg openings of the undergarment, and the undergarment can be easily attached to the body together with the undergarment.

< modification example >

Fig. 10 is a cross-sectional view of the diaper 10 similar to fig. 5, which is an example of a modification. In the present modification, in the high rigidity region 41, an auxiliary sheet 70 made of a fibrous nonwoven fabric having elasticity or inelasticity is fixed to the skin-facing surface side of the side sheet 25 (or the 1 st side sheet 25A) with an adhesive. By disposing the auxiliary sheet 70 in the high rigidity region 41 in this manner, the number of laminated layers becomes larger than the number of laminated layers of the low rigidity region 42, and the difference in rigidity between the two

regions

41 and 42 becomes clear. The auxiliary sheet 70 may be fixed to the non-skin-facing surface side of the side sheet 25, not to the skin-facing surface side of the side sheet 25, or may be formed of a plurality of sheets instead of one sheet.

Various known materials generally used for such articles can be used for each constituent member constituting the diaper 10 of the present invention without limitation, except for the materials described in the specification. In the specification and claims, the terms "1 st" and "2 nd" are used to distinguish the same elements, positions, and the like for the sake of simplicity.

Description of the reference numerals

10. A diaper; 11. a front waist region; 12. a rear waist region; 13. a crotch region; 14. the waist is opened; 15. a leg opening; 16. a diaper body; 17. a waist belt; 18A, 18B, bonding wires; 21. an inner layer sheet; 22. an outer layer sheet; 23. an absorbent body; 25. a side panel; 26. a leg elastic body; 30. an elastic sheet; 33. a waist elastic body; 40. a side flap panel; 41. a high stiffness region; 42. a low stiffness region; 70. an elastic sheet; p, longitudinal center line; x, transverse direction; y, longitudinal direction.

Claims

1. A disposable diaper having a longitudinal direction and a transverse direction, and a longitudinal centerline bisecting the dimension in the transverse direction, comprising: a diaper main body having an absorber, which has a front waist region, a rear waist region, and a crotch region located between the front waist region and the rear waist region; a pair of waist belts for connecting the front waist region and the rear waist region; the waist is opened; and a pair of leg openings, the disposable diaper being characterized in that,

the pair of waist belts are joined to the diaper main body at joining lines that are spaced from the leg opening sides toward the waist opening sides in the front and rear waist regions,

the diaper main body has side flaps extending in the longitudinal direction outside the lateral direction of both side edge portions of the absorbent body, the side flaps having high-rigidity regions with higher rigidity than other regions at edge portions extending along the leg openings, both end portions of the high-rigidity regions being located on the joining line,

the diaper body includes: a liquid permeable inner layer sheet; a liquid impermeable outer sheet; the absorber is positioned between the inner layer sheet and the outer layer sheet; and a pair of side sheets disposed on both side portions of the absorbent body, the side sheets being provided with separate elastic sheets to form the high-rigidity region,

the side sheet has a 1 st sheet on the skin-facing surface side and a 2 nd sheet on the non-skin-facing surface side, and the elastic sheet is located between the 1 st sheet and the 2 nd sheet.

2. A disposable diaper having a longitudinal direction and a transverse direction, and a longitudinal centerline bisecting the dimension in the transverse direction, comprising: a diaper main body having an absorber, which has a front waist region, a rear waist region, and a crotch region located between the front waist region and the rear waist region; a pair of waist belts for connecting the front waist region and the rear waist region; the waist is opened; and a pair of leg openings, the disposable diaper being characterized in that,

a plurality of leg elastic bodies extending in the longitudinal direction are arranged in the high rigidity region,

the leg elastic bodies are disposed between the laminated sheet members in the high rigidity region, a plurality of waist elastic bodies are disposed in the waist band, and the leg elastic bodies and the waist elastic bodies do not overlap each other in the thickness direction of the sheet members.

3. The diaper according to claim 1 or 2,

the width dimension of the high rigidity region is 3mm to 30 mm.