Pant-type disposable diaper

Abstract

A pant-type disposable diaper (1) has an absorbent main body (10) and a waist circumference portion (20) which is stretchable in a left-right direction, wherein the waist circumference portion (20) has a belly side waist circumference portion (30) and a back side waist circumference portion (40), the belly side waist circumference portion (30) and the back side waist circumference portion (40) are connected in a ring shape by a pair of side joints (50A, 50B), and in a natural state, a shortest distance (W30s) along a surface of the belly side waist circumference portion (30) from one side joint (50A) to the other side joint (50B) at a certain position in an up-down direction is greater than a shortest distance (W40s) along a surface of the back side waist circumference portion (40) from one side joint (50A) to the other side joint (50B).

Description

Technical Field

[0001] This invention relates to disposable underwear-type diapers. Background Technology

[0002] In the past, in order to prevent the diaper from sagging off the wearer's body (waistline) during wear, most disposable underwear-type diapers have adopted the following measures: as many elastic waistbands or other elastic components as possible are provided to strengthen the waistband and make the diaper fit snugly against the wearer's body. For example, Patent Document 1 discloses an underwear-type absorbent article in which multiple elastic waistbands 52 are arranged circumferentially in the waistband portion E located at the waist.

[0003] Prior art literature

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2001-314441 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] Generally, when wearing panty-style diapers, the wearer inserts their legs (feet) into the openings with the waistband and leg openings open. In conventional panty-style diapers like those in Patent Document 1, because a uniform contraction force acts along the circumference of the waistband, the front (abdominal) and back (dorsal) sides easily open equally when the waistband and leg openings are opened. However, since the human leg is shaped to protrude towards the toes (front), the wearer's toes can easily get caught on the front (abdominal) edge of the leg openings and waistband openings, creating a problem of difficulty in wearing (difficulty in smoothly inserting the legs).

[0008] The present invention was made in view of the aforementioned problems, and its object is to provide a pant-type disposable diaper that allows for easy and smooth leg insertion during wear.

[0009] Solution for solving the problem

[0010] The main invention for achieving the above-mentioned objective is a disposable underwear-type diaper, which has intersecting vertical, horizontal, and front-back directions. The disposable underwear-type diaper has an absorbent body that can absorb liquid and a waistband that can stretch in the horizontal direction. The waistband is characterized by having a ventral waistband and a dorsal waistband, which are connected in a ring shape by a pair of lateral joints. In its natural state, at a certain position in the vertical direction, the shortest distance along the surface of the ventral waistband from one lateral joint to the other lateral joint is greater than the shortest distance along the surface of the dorsal waistband from one lateral joint to the other lateral joint.

[0011] Other features of the invention will become apparent from the description and accompanying drawings.

[0012] The effects of the invention

[0013] According to the present invention, a pant-type disposable diaper is provided that allows for easy and smooth leg insertion during wear. Attached Figure Description

[0014] Figure 1 This is a rough 3D diagram of Diaper 1.

[0015] Figure 2 This is a top view of diaper 1 in its unfolded and fully extended state.

[0016] Figure 3 yes Figure 2 A rough cross-sectional view at line A-A.

[0017] Figure 4 yes Figure 2 A rough cross-section at line B-B.

[0018] Figure 5 This is a diagram showing a schematic cross-section of diaper 1 in its natural state, in the vertical direction.

[0019] Figure 6 This is a top view of diaper 1 in its unfolded and natural state.

[0020] Figure 7 This diagram illustrates the method of comparing the shortest distance between a pair of lateral joints 50A and 50B on the ventral waist portion 30 and the dorsal waist portion 40.

[0021] Figure 8A and Figure 8B This is a diagram illustrating an example of a method for stretching diaper 1 in the left-right direction.

[0022] Figure 9It is a graph showing the results of measuring the contraction force when the waist circumference 20 is expanded and the contraction force when the waist circumference 20 is contracted during actions such as putting on diapers 1.

[0023] Figure 10 This is a diagram showing a modified example of the ventral low-twist region 61. Detailed Implementation

[0024] Based on the description in this specification and the accompanying drawings, at least the following will become clear.

[0025] A disposable diaper in the form of underwear has intersecting vertical, horizontal, and front-back directions. The diaper has an absorbent body and a waistband that can stretch in the horizontal direction. The waistband has a ventral waistband and a dorsal waistband, which are connected in a ring shape by a pair of lateral joints. In its natural state, at a certain position in the vertical direction, the shortest distance along the surface of the ventral waistband from one lateral joint to the other is greater than the shortest distance along the surface of the dorsal waistband from one lateral joint to the other.

[0026] Based on this type of underwear-style disposable diaper, when the waistband is opened from a natural position during wear, the abdominal waistband, which is already wider than the back waistband, can be opened even more easily. Therefore, when the wearer inserts their feet into the waistband opening and leg opening, the toes are less likely to get caught on the edge of the abdominal waistband, allowing for smooth leg insertion.

[0027] In this underwear-type disposable diaper, it is preferable that when the waist portion is extended in the left-right direction until it becomes 85% of the size of the single piece of the sheet member constituting the waist portion, at a certain position in the up-down direction, the shortest distance along the surface of the abdominal waist portion from one side joint to the other side joint is greater than the shortest distance along the surface of the back waist portion from one side joint to the other side joint.

[0028] Based on this type of disposable underwear diaper, when the waist and leg openings are actually widened (to 85% elongation) during the wearing action, the ventral waist opening is wider than the back waist opening. Therefore, it is difficult for the wearer's toes to get caught on the edge of the ventral waist opening. As a result, it is easier and smoother to insert the legs.

[0029] In this underwear-type disposable diaper, preferably, the shortest distance along the surface of the abdominal waistband from one side joint to the other side joint at the lower end of the waistband in the vertical direction is greater than the shortest distance along the surface of the back waistband from one side joint to the other side joint.

[0030] Based on this type of disposable underwear diaper, when the leg opening is actually widened during the wearing action, the lower edge of the abdominal waistband widens more than the lower edge of the back waistband. Therefore, it is difficult for the wearer's toes to get caught in the leg opening of the abdominal waistband. Thus, the action of inserting the leg into the leg opening, which is difficult to visually confirm from the outside of the diaper, can be performed smoothly during the wearing action.

[0031] In this underwear-type disposable diaper, it is preferable that the contractile force in the left-right direction of the back waistband is greater than the contractile force in the left-right direction of the abdominal waistband.

[0032] Based on this type of disposable underwear diaper, when the waistband is widened during the wearing action, the abdominal waistband tends to widen more easily in the left and right directions compared to the back waistband, making it difficult for the wearer's toes to get caught on the abdominal waistband. Therefore, it is easier to smoothly extend the legs into the waistband opening and leg opening.

[0033] In this underwear-type disposable diaper, it is preferable that the left-right contraction force acting on the area per unit length in the vertical direction within the lower 1 / 4 range of the abdominal waistband is less than the left-right contraction force acting on the area per unit length in the vertical direction within the upper 3 / 4 range of the abdominal waistband.

[0034] In this type of disposable underwear-style diaper, the lower end of the abdominal waistband (the area extending 1 / 4 from the bottom) forms part of the leg opening. Therefore, if the lateral contraction force at this lower end weakens, the leg opening can be easily widened during diaper-wearing. Thus, when caregivers or others put on diapers for infants or other wearers with their hands inside the leg opening and the opening widened, the abdominal (front) side of the leg opening can be easily widened. This prevents the wearer's toes from getting caught on the abdominal (front) side of the leg opening.

[0035] In this underwear-type disposable diaper, it is preferable that the left-right contraction force acting on the area per unit length in the vertical direction within the upper half of the waist portion is less than the left-right contraction force acting on the area per unit length in the vertical direction within the lower half of the waist portion.

[0036] In this type of disposable diaper, the lateral elasticity in the upper half of the waistband is weakened, making it easier to widen the waistband opening. Therefore, when caregivers or others put on the diaper for infants or young children with their hands inside the waistband opening and the opening already widened, the waistband opening can be easily widened. This also makes it easier for the wearer's legs to fit into the waistband opening.

[0037] In this underwear-type disposable diaper, it is preferable that the shrinkage force when the waist portion is stretched in the left-right direction until it becomes 85% of the size of the single piece of the sheet member constituting the waist portion is more than twice the shrinkage force when the waist portion is contracted in the left-right direction until it changes from 85% to 77% of the size of the single piece of the sheet member constituting the waist portion.

[0038] Based on this type of underwear-style disposable diaper, even when the waistband is widened as much as possible to prevent the wearer's legs from getting caught, the excessive tightness exerted when the waistband contracts and fits against the wearer's skin can be suppressed, making it difficult for the wearer to feel uncomfortable.

[0039] In this underwear-type disposable diaper, preferably, the absorbent body has an absorbent core, the abdominal waistband has an abdominal low-stretch region with lower contractile force in the left-right direction than other regions, and the width of the abdominal low-stretch region in the left-right direction is greater than the width of the absorbent core in the left-right direction.

[0040] In this type of disposable underwear diaper, the highly rigid absorbent core is difficult to contract in the lateral direction. Therefore, the low-elasticity area on the abdomen, which overlaps with the absorbent core, also has difficulty contracting in the lateral direction. Thus, by setting the low-elasticity area on the abdomen in a larger lateral direction than the absorbent core, the abdomen waistband as a whole is difficult to contract in the lateral direction. Consequently, between a pair of lateral joints, the lateral length of the abdomen waistband tends to become longer than the lateral length of the back waistband, preventing the wearer's legs from getting caught during diaper wearing.

[0041] In this underwear-type disposable diaper, preferably, the abdominal waistband has a first abdominal stretching region that is adjacent to the two sides of the abdominal low stretching region in the left and right directions and has a greater contraction force in the left and right directions than the abdominal low stretching region, and the width of the abdominal low stretching region in the left and right directions is greater than the sum of the widths of the first abdominal stretching region in the left and right directions.

[0042] In this type of disposable underwear-style diaper, the proportion of the low-elasticity area on the abdominal side waistband is greater than that of the first elasticity area on the abdominal side, resulting in a larger portion of the abdominal side waistband that reaches its maximum elongation (i.e., the low-elasticity area). Therefore, the abdominal side waistband tends to expand in the lateral direction, making it more difficult for the wearer's legs to get caught during diaper wearing.

[0043] In this underwear-type disposable diaper, preferably, in the natural state of the abdominal waistband, the distance between the outer end of the absorbent core in the left-right direction and the inner end of the first abdominal stretchable area is greater than the width of the first abdominal stretchable area in the left-right direction.

[0044] Based on this type of underwear-style disposable diaper, by making the area with low elasticity and high softness on the abdominal waistband larger than the first elastic area on the abdominal side with high elasticity, it is easier to expand the abdominal waistband from its natural state.

[0045] ===Implementation Methods===

[0046] As an example of the absorbent underwear-type articles involved in this invention, a disposable diaper (hereinafter also referred to as "diaper 1") is used for illustration. However, the diaper-type articles involved in this invention can also be applied to absorbent underwear-type sanitary napkins, other absorbent underwear-type articles, and other absorbent underwear-type articles other than diapers.

[0047] <Composition of Diaper 1>

[0048] Figure 1 This is a rough 3D diagram of Diaper 1. Figure 2 This is a top view of diaper 1 in its unfolded and fully extended state. Figure 3 yes Figure 2 A rough cross-sectional view at line A-A. Figure 4 yes Figure 2A schematic cross-sectional view at line B-B. In this specification, the term "maximum elongation state" for diaper 1 refers to a state in which the diaper 1 as a whole (the entire product) is elongated until it is almost wrinkle-free. Specifically, it refers to a state in which the dimensions of each component constituting diaper 1 are the same as (consistent with or close to) the dimensions of the individual sheet components constituting those components, for example, dimensions with an error within ±5%. For example, it refers to a state in which the abdominal waistband 30, described later, is elongated until it becomes the same size as the individual skin side sheet 31 constituting the abdominal waistband 30 (see reference...). Figure 3 ).

[0049] Diaper 1 Figure 1 The underwear shown has intersecting vertical, horizontal, and front-back directions, and has a waist opening BH and a pair of leg openings LH and LH.

[0050] The upper side of the waistband opening corresponds to the lower side, and the lower side corresponds to the crotch opening. Additionally, the front side corresponds to the wearer's abdomen, and the back side corresponds to the wearer's back. Figure 2 In its unfolded state, diaper 1 has intersecting longitudinal and transverse directions. The longitudinal direction is along... Figure 1 The vertical direction is equivalent to the length direction of the absorbent body 10. The horizontal direction is along... Figure 1 The left and right directions within. Additionally, such as... Figure 3 As shown, the direction in which the material layers constituting diaper 1 are laid is defined as the thickness direction. In the thickness direction, the side that comes into contact with the wearer's skin is defined as the skin side, and the opposite side is defined as the non-skin side.

[0051] The diaper 1 has an absorbent body 10 and a waistband 20 disposed on the non-skin side of the absorbent body 10. Furthermore, the waistband 20 has a ventral waistband 30 corresponding to the front panel of the diaper 1 and a dorsal waistband 40 corresponding to the back panel of the diaper 1. That is, the diaper 1 of this embodiment is a so-called three-part type underwear-type diaper, with the absorbent body 10 as the first part, which rests against the wearer's crotch and absorbs urine and other excrement; the ventral waistband 30 as the second part, which covers the wearer's ventral side; and the dorsal waistband 40 as the third part, which covers the wearer's dorsal side. However, the diaper 1 is not limited to a three-part type; it can also be a two-part type underwear-type diaper with the waistband 20 and absorbent body 10 integrally formed by the front and back panels.

[0052] exist Figure 2In its unfolded state, with the abdominal waist section 30 and the back waist section 40 arranged parallel to each other in a longitudinally spaced manner, an absorbent body 10 is placed between them. The longitudinal ends 10ea and 10eb of the absorbent body 10 are respectively joined and fixed to the skin side of the nearest waist section 30 and 40, giving it a roughly H-shaped appearance when viewed from above. From this state, the absorbent body 10 is folded in half with its central position CL in the longitudinal direction as the folding position. In this folded state, the side portions 30sw and 40sw of the abdominal waist section 30 and the back waist section 40, facing each other, are joined and connected to each other in the left and right directions, forming a pair of lateral joints 50, 50. That is, the abdominal waist section 30 and the back waist section 40 are formed into a ring shape by the pair of lateral joints 50, 50. Thus, it becomes... Figure 1 The diaper 1 is in the form of an underwear-like garment, with a waist opening BH and a pair of leg openings LH, LH as shown. Furthermore, the side joints 50 are formed by known joining methods such as melting or bonding.

[0053] (Absorbent Subject 10)

[0054] like Figure 3 as well as Figure 4 As shown, the absorbent body 10 includes: an absorbent core 11 for absorbing excrement; a top sheet 12 disposed on the skin side in the thickness direction of the absorbent core 11; and a bottom sheet 13 disposed on the non-skin side of the absorbent core 11. However, the absorbent body 10 may also include other sheet members. For example, a sub-sheet (not shown) may be provided between the top sheet 12 and the absorbent core 11 in the thickness direction.

[0055] The absorbent core 11 is a component that absorbs and retains excretory fluids such as urine, and can be formed, for example, from absorbent fibers such as pulp fibers incorporating highly absorbent polymers (SAP). Alternatively, the outer peripheral surface of the absorbent core 11 can also be made of a liquid-permeable sheet component such as thin paper or nonwoven fabric (e.g., Figure 4 The core-coated sheet 11b) is covered.

[0056] The top sheet 12 is a liquid-permeable sheet, such as a hydrophilic hot-air nonwoven fabric or spunbond nonwoven fabric. The bottom sheet 13 is a double-layer structure consisting of a liquid-impermeable sheet 13a and a hydrophobic outer sheet 13b disposed on its non-skin side. The liquid-impermeable sheet 13a can be, for example, a resin film, and the outer sheet 13b can be, for example, a soft nonwoven fabric.

[0057] On both sides of the absorbent body 10 in the left-right direction, a pair of leak-proof wall portions 15 are provided along the longitudinal direction (the length direction of the absorbent body 10). In this embodiment, the leak-proof wall portions 15 are formed by the aforementioned outer sheet 13b. Specifically, in the left-right direction (lateral direction), a portion of the outer sheet 13b extends outward beyond the two ends 11es, 11es of the absorbent core 11, and as shown... Figure 4 The diaper is bent towards the skin at the outer ends 15es1 and 15es2. Furthermore, by bending at multiple points closer to the skin than the absorbent core 11, a pair of leak-proof wall portions 15 are formed. At the skin-side ends (terminal portions) of the leak-proof wall portions 15, elastic members 16, such as elastic bands, are installed in a longitudinally elongated state (the length direction of the absorbent body 10). When the diaper 1 is worn, based on the elasticity of these leak-proof wall members 16, the leak-proof wall portions 15 stand upright towards the wearer's skin, starting from the outer ends 15es and 15es, and match the wearer's crotch area.

[0058] Furthermore, on both sides of the absorbent body 10 in the left-right direction, elastic leg members 17, such as rubber bands, are installed in a state of elongation along the longitudinal direction (the length direction of the absorbent body 10). When the diaper 1 is worn, based on the elasticity of the leg members 17, the two sides of the absorbent body 10 contract, easily matching the wearer's leg circumference.

[0059] (Waist circumference 30)

[0060] like Figure 3 As shown, the abdominal waist portion 30 includes: a skin side sheet 31 disposed on the skin side in the thickness direction; a non-skin side sheet 32 ​​laminated adjacent to the non-skin side of the skin side sheet 31; and an abdominal waist elastic member 35 (hereinafter referred to as "waist elastic member 35") disposed between the skin side sheet 31 and the non-skin side sheet 32 ​​in the thickness direction. The abdominal waist portion 30 is basically a double-layer structure of skin side sheet 31 and non-skin side sheet 32, but it may also have a configuration of three or more layers, including, for example, the skin sheet 36 described later. The skin side sheet 31 is Figure 2 The sheet member shown is rectangular in shape when viewed from above, and is formed, for example, from SMS nonwoven fabric. The non-skin side sheet 32 ​​is also a rectangular sheet member when viewed from above, and is formed, for example, from spunbond nonwoven fabric.

[0061] The abdominal waistband 30 of this embodiment has a folded-back portion 32f where the upper end (front end in the longitudinal direction) of the non-skin side panel 32 is folded back from the non-skin side to the skin side and from the upper to the lower side in the vertical direction. By covering a portion (upper end) of the skin side panel 31 with this folded-back portion 32f, the upper edge of the skin side panel 31 can be prevented from digging into the wearer's skin. However, it is not necessary to provide the folded-back portion 32f.

[0062] The waist elastic member 35 is, for example, a linear elastic member made of rubber bands, and multiple such members are arranged vertically between the skin side panel 31 and the non-skin side panel 32, and are installed in a state of extension in the lateral direction. Through the elasticity of this waist elastic member 35, the abdominal waist section 30 matches the abdominal waist of the wearer.

[0063] The waist elastic member 35 can be installed using an adhesive such as a hot melt adhesive. For example, the waist elastic member 35 can be installed by applying a hot melt adhesive to the waist elastic member 35 and elongating it to a specified elongation ratio, then sandwiching it between the skin side panel 31 and the non-skin side panel 32. That is, the skin side panel 31 and the non-skin side panel 32 are joined together with an adhesive through the waist elastic member 35. Alternatively, the waist elastic member 35 can also be installed by applying adhesive to both the skin side panel 31 and the non-skin side panel 32.

[0064] Additionally, the flank waist area 30 may also have a skin panel 36. For example... Figure 3 As shown, the skin cover 36 is a sheet member arranged to cover the upper end 10ea (the front end in the longitudinal direction) of the absorbent body 10 from the skin side, and functions as a cover. Therefore, when wearing the diaper 1, the upper edge of the absorbent body 10 can be prevented from digging into the wearer's skin. The skin cover 36 is formed, for example, from SMS nonwoven fabric. However, the skin cover 36 may not be necessary.

[0065] The abdominal waist portion 30 is joined to the non-skin side of the absorbent body 10 via a main body joint 23 made of an adhesive such as a hot melt adhesive (see reference). Figure 3 The body joint 23 is formed by applying an adhesive in a spiral or Ω-shaped pattern in the area where the ventral waist portion 30 overlaps with the absorbent body 10 when viewed in the thickness direction.

[0066] (Back and waist circumference 40)

[0067] The back waist portion 40 has a configuration substantially the same as that of the abdominal waist portion 30. Specifically, the back waist portion 40 includes: a skin-side sheet 41 disposed on the skin side in the thickness direction; a non-skin-side sheet 42 laminated adjacent to the non-skin side of the skin-side sheet 41; and a back waist elastic member 45 (hereinafter also simply referred to as "waist elastic member 45") disposed between the skin-side sheet 41 and the non-skin-side sheet 42 in the thickness direction. The configuration of each member is almost identical to that of the abdominal waist portion 30.

[0068] On the other hand, the shape of the back waist section 40 differs from that of the ventral waist section 30. Specifically, as... Figure 2Thus, the back waist portion 40 has a hip cover 40b that is approximately trapezoidal in shape, located on the lower side in the vertical direction compared to the side joint portion 50 (side portion 40sw). In the hip cover 40b, by setting the hip cover 40b so that its width increases from the lower side to the upper side in the vertical direction, the back waist portion 40 can cover the wearer's hips when the diaper 1 is worn.

[0069] The back waist section 40 is joined to the non-skin side of the absorbent body 10 via a main body joint 24 made of an adhesive such as a hot melt adhesive (see reference). Figure 3 The main body joint 24 is formed in a substantially identical manner to the main body joint 23.

[0070] <Regarding low-expansion areas>

[0071] As described above, in the waist section 20 (30, 40) of the diaper 1, the waist elastic members 35, 45 are installed in a state of elongation in the left and right directions. Furthermore, the contraction force exhibited by these waist elastic members 35, 45 imparts elasticity to the waist section 20 in the left and right directions (circumferential direction of the waist opening BH).

[0072] On the other hand, when the waist elastic members 35 and 45 exert a strong contractile force on the entire area of ​​the waist portion 20 (30, 40), the waist opening BH and leg opening LH become difficult to open, making it difficult for the wearer to insert their legs into the waist opening BH and leg opening LH when wearing the diaper 1. Especially on the front (abdominal) side of the diaper 1, there is a possibility that the wearer's toes may get caught on the edge of the waist opening BH and leg opening LH. Therefore, in the diaper 1 of this embodiment, at least a portion of the waist portion 20 is provided with a region where the contractile force formed by the waist elastic members 35 and 45 is lower than that of other regions (such as the low-elasticity abdominal region 61 described later), making it easier to open the waist portion 20 and thus allowing the wearer's legs to be inserted smoothly.

[0073] The waist elastic member 35 of the abdominal waistband portion 30 of the diaper 1 has: a continuous elastic member 35s extending from one end (side joint 50) in the left-right direction to the other end (side joint 50); and a discontinuous elastic member 35c that is at least partially discontinuous in the left-right direction. Figure 2 In the middle, a plurality of continuous elastic members 35s, 35s... are arranged in the upper region of the abdominal waist circumference 30 in the vertical direction, and a plurality of discontinuous elastic members 35c, 35c... are arranged in the lower region adjacent to the region where the continuous elastic members 35s are arranged.

[0074] The discontinuous elastic member 35c has a central portion in the left-right direction composed of... Figure 2The discontinuity 61 shown by the diagonal line indicates that the contraction force formed by the waist elastic member 35 is weaker or non-existent in this discontinuity 61. That is, the area in the abdominal waist portion 30 where the discontinuity 61 is formed becomes a low-elasticity region with reduced contraction force formed by the waist elastic member 35 compared to other areas. Hereinafter, the discontinuity 61 will also be referred to as the abdominal low-elasticity region 61.

[0075] The low-elasticity region 61 on the ventral side is formed, for example, by the following method. First, in the manufacturing process of the ventral waist portion 30, a waist elastic member 35, which is elongated in the left-right direction, is bonded to the skin side panel 31 and the non-skin side panel 32 constituting the ventral waist portion 30. At this time, the waist elastic member 35 is not bonded to the skin side panel 31 and the non-skin side panel 32 in the area where the discontinuity portion 61 is formed. Next, the waist elastic member 35 disposed in the area overlapping with the discontinuity portion 61 is cut near the center position in the left-right direction. Then, the cut waist elastic member 35 contracts outwards in the left-right direction from the cut position, and stops contracting at both ends of the discontinuity portion 61 in the left-right direction (the positions where the waist elastic member 35 is bonded). As a result, a portion of the waist elastic member 35 (discontinuous elastic member 35c) becomes discontinuous in the left-right direction, and the low-elasticity region 61 on the ventral side is formed in this discontinuous portion. Thus, the action of forming a discontinuous section by contracting a portion of the waist elastic member 35 is also called "cutback".

[0076] Alternatively, the low-elasticity zone 61 on the ventral side can be formed by methods other than cutting. For example, an adhesive can be pre-applied to the entire ventral waist portion 30 before installing the waist elastic member 35, and the waist elastic member 35 can be cut at multiple locations in a specified area (the area where the discontinuity 61 is formed) to create a discontinuity, thereby forming a low-elasticity zone 61 on the ventral side with reduced elasticity in this area.

[0077] exist Figure 2 In the middle, the area in the abdominal waist circumference 30 that overlaps with the abdominal low stretch region 61 in the vertical direction and is adjacent to the two outer sides of the abdominal low stretch region 61 in the horizontal direction is defined as the first abdominal stretch region 62. Figure 2 The vertical length of the abdominal waist portion 30, as shown by the mesh pattern, is H61. Furthermore, the area adjacent to the upper side of the abdominal low stretch region 61 and the abdominal first stretch region 62 in the vertical direction is designated as the abdominal second stretch region 63. Figure 2The vertical length of the abdominal waist portion 30 shown in outline is H63. The first abdominal stretching region 62 and the second abdominal stretching region 63 are regions that, compared with the low abdominal stretching region 61, are more strongly affected by the lateral contraction force formed by the continuous elastic member 35s or the discontinuous elastic member 35c.

[0078] In addition, similar to the abdominal waist portion 30, the back waist elastic member 45 provided in the back waist portion 40 has: a continuous elastic member 45s that extends from one end in the left-right direction to the other end; and a discontinuous elastic member 45c that is at least partially discontinuous in the left-right direction.

[0079] The discontinuous elastic member 45c has a central portion in the left-right direction. Figure 2 The discontinuity 71, shown by the diagonal lines, weakens or eliminates the contractile force generated by the waist elastic member 45. That is, the area in the back waist portion 40 with the discontinuity 71 becomes a low-elasticity region with reduced contractile force generated by the waist elastic member 45 compared to other areas. Hereinafter, the discontinuity 71 will also be referred to as the back low-elasticity region 71. Similar to the ventral low-elasticity region 61, the back low-elasticity region 71 can be formed by cutting off a portion of the back waist elastic member 45. However, the back low-elasticity region 71 may not be necessary in the back waist portion 40 of the diaper 1. That is, the back waist elastic member 45 may be entirely composed of continuous elastic members 45s.

[0080] Additionally, the area in the back waist section 40 that overlaps with the abdominal low stretch area 61 in the vertical direction is designated as the back first stretch area 81. Figure 2 The vertical length of the back waist portion 40, as shown in the mesh pattern, is H61. Additionally, the area adjacent to the upper side of the first back stretch region 81 in the vertical direction is designated as the second back stretch region 82. Figure 2 The length of the back waist section 40, shown in outline, is H63 in the vertical direction.

[0081] Figure 5 This is a diagram showing a schematic cross-section of diaper 1 in its natural state, in the vertical direction. Figure 5 In, for example, in relation to Figure 4The image shows a cross-section of the waist section 20 of the diaper 1 viewed from above, at a position corresponding to view B. The term "natural state" refers to the state of the diaper 1 after being placed for a predetermined time. For example, after removing the diaper 1 from its packaging, the abdominal waist section 30 and the back waist section 40 are stretched outwards in the left and right directions to reach their maximum extension. This maximum extension is maintained for a predetermined time (e.g., 15 seconds), after which the stretching of the diaper 1 is released, and it is placed on a flat surface such as a table. The state after being placed flat on such a surface for 5 minutes is defined as the natural state.

[0082] Figure 6 This is a top view of diaper 1 in its unfolded and natural state. Figure 6 Is with General Figure 5 The diagram shows the diaper 1 in its natural state, with the side seams 50, 50 separated and unfolded into the abdominal waistband 30 and the back waistband 40. (The last sentence appears to be incomplete and possibly refers to a diagram or diagram.) Figure 6 When the diaper 1 is unfolded in its natural state, the waist sections 30 and 40 are contracted in the left and right directions due to the elastic force exerted by the elastic members 35 and 45, respectively. The amount of contraction varies depending on the magnitude of the elastic force exerted by the elastic members 35 and 45. Therefore, the length (width) of the waist sections 30 and 40 in their natural state is different in the left and right directions. Figure 6 In certain situations, the lower the waistline (30mm and 40mm), the greater its lateral length (width). Furthermore, in a natural diaper 1, the waistline (30mm and 40mm) contracts laterally, creating multiple folds on the surface. However, in... Figure 5 , Figure 6 For ease of explanation, such folds are not shown.

[0083] exist Figure 5 as well as Figure 6In its natural state, the diaper 1's abdominal waistband 30 exhibits elasticity due to the discontinuous elastic member 35c provided in the first abdominal stretchable region 62, resulting in a relatively large contraction force along the left-right direction (waistband direction). On the other hand, in the abdominal low stretchable region 61, a portion of the waistband elastic member 35 experiences reduced elasticity due to cutting or other reasons, thus weakening the contraction force along the left-right direction (waistband direction). As a result, due to the contraction force of the first abdominal stretchable region 62, the abdominal low stretchable region 61 is stretched to both sides in the left-right direction, becoming elongated until it almost reaches its maximum elongation. In other words, the area within the abdominal waistband 30 where the abdominal low stretchable region 61 is located becomes elongated until it reaches a size almost identical to the individual dimensions of the sheet members constituting the abdominal waistband 30 (skin side sheet 31 and non-skin side sheet 32). Furthermore, a size almost identical to the individual dimensions of the sheet members refers to a size that includes an error of approximately ±5% relative to the sheet member's overall dimensions.

[0084] On the other hand, the contraction force along the waist is weakened in the back waist section 40 in the back low stretch region 71. However, compared with the abdominal low stretch region 61, the back low stretch region 71 has a shorter length and smaller area in the left and right directions. Therefore, the contraction force of the back waist section 40 as a whole is greater than that of the abdominal waist section 30.

[0085] As a result, through the contraction force acting on the back waist portion 40 in the left-right direction (waistline), the abdominal waist portion 30 is stretched to both sides in the left-right direction (waistline), thus positioning the pair of lateral joints 50, 50 connecting the abdominal waist portion 30 and the back waist portion 40 as follows: Figure 5 It moves in that direction towards the rear (back side). Therefore, at a certain position in the vertical direction, the distance W30s along the surface of the abdominal waist circumference 30 from one side joint 50 (set as 50A) to the other side joint 50 (set as 50B) is greater than the distance W40s along the surface of the back waist circumference 40 from one side joint 50A to the other side joint 50B (W30s > W40s).

[0086] That is, in Figure 6When comparing the same position in the vertical direction when the parts are unfolded, the length (width) of the abdominal waist portion 30 in the left-right direction is greater than the length (width) of the back waist portion 40 in the left-right direction. Specifically, in the vertical direction, the shortest distance W30s along the surface of the abdominal waist portion 30 from one side joint 50A to the other side joint 50B, located at a position (a certain position) below the upper end of the abdominal waist portion 30, is greater than the shortest distance W40s along the surface of the back waist portion 40 from one side joint 50A to the other side joint 50B, located at a position (a certain position) below the upper end of the back waist portion 40, located at the same position as the abdominal waist portion 30, located at the same position as the other side joint 50B.

[0087] Therefore, during the wearing of diaper 1, when the waist opening BH and leg opening LH of the waist section 20 are widened from a natural position, the abdominal waist section 30, which is originally wider than the back waist section 40, can be widened even more. Thus, when the wearer inserts their feet into the waist opening BH and leg opening LH, the wearer's toes are less likely to get caught on the edge of the abdominal waist section 30, allowing for smooth leg insertion.

[0088] In addition, as a method for comparing the shortest distance between a pair of lateral joints 50A and 50B in the abdominal waistband 30 and the dorsal waistband 40 in the diaper 1 in its natural state, the following methods can be listed as an example. Figure 7 This diagram illustrates the method of comparing the shortest distance between a pair of lateral joints 50A and 50B on the ventral waist portion 30 and the dorsal waist portion 40.

[0089] First, regarding the diaper 1 in its natural state, use a clamp 150 (such as a round-headed clip) to grasp one of the two side joints 50A and 50B, and suspend the diaper 1 from above. Figure 7 In this state, the diaper 1 is formed by the clamp 150 gripping the side joint 50B and suspending the diaper 1.

[0090] Furthermore, the diaper 1 in its suspended state is visually inspected from the back (rear side) along the horizontal direction.

[0091] Therefore, the side joint 50A on the opposite side to the side joint 50B held by the clamp 150 can be visually confirmed. This is because, as Figure 5 As described, the side joints 50, 50 in the waist section 20 move toward the rear side in the front-back direction.

[0092] Thus, in a natural state, when one of the side joints (50B) is grasped and viewed from the rear in the front-to-back direction while the diaper 1 is hanging, if at least half of the other side joint (50A) can be visually confirmed, it can be said that the shortest distance between the side joints in the abdominal waist circumference 30 is greater than the shortest distance between the side joints in the back waist circumference 40. Furthermore, the state that "more than half of the side joint 50A can be visually confirmed" refers to the surface of one side of the side joint 50A in the front-to-back direction (i.e.,...) Figure 2 The state in which more than half of the area (either of the 40sw and 30sw surfaces) can be visually confirmed.

[0093] Furthermore, preferably, when the diaper 1 is put on, and the waist circumference 20 is actually expanded, at a certain position in the vertical direction, the length (width) of the abdominal waist circumference 30 in the horizontal direction is greater than the length (width) of the back waist circumference 40 in the horizontal direction. Generally speaking, when the waist circumference 20 is expanded during the action of putting on the diaper 1, it is more common for the waist circumference 20 to be expanded to about 85% of its maximum elongation state (100% elongation state). That is, preferably, in the left-right direction, when the waist portion 20 is extended in the left-right direction until it becomes 85% of the size of the single piece of the sheet member constituting the waist portion 20 (e.g., skin side pieces 31, 41, etc.) (85% elongation state), at a certain position in the up-down direction, the shortest distance along the surface of the abdominal waist portion 30 from one side joint 50A to the other side joint 50B is greater than the shortest distance along the surface of the back waist portion 40 from one side joint 50A to the other side joint 50B.

[0094] With this configuration, when the waist opening BH and leg opening LH of the waist section 20 are actually widened during the wearing action of the diaper 1 (to an 85% stretched state), the abdominal waist section 30 is widened more than the back waist section 40. Therefore, it is difficult for the wearer's toes to hook onto the edge of the abdominal waist section 30. As a result, the leg insertion action is easier and smoother.

[0095] Furthermore, when putting on diaper 1, the following actions are performed first: the wearer inserts both legs into the open waist opening BH, and then extends the legs one by one through the leg openings LH. While the action of inserting the legs into the waist opening BH can be visually confirmed from the outside of diaper 1, the action of extending the legs through the leg openings LH is difficult to visually confirm from the outside of diaper 1. Therefore, compared to the action of inserting the legs into the waist opening BH, the action of extending the legs through the leg openings LH carries a higher risk of the legs getting caught.

[0096] Therefore, more preferably, when wearing the diaper 1, at the lower edge of the waist portion 20 forming the leg opening LH, the length (width) of the ventral waist portion 30 in the left-right direction is greater than the length (width) of the back waist portion 40 in the left-right direction. That is, in the left-right direction, when the waist portion 20 is extended in the left-right direction until it becomes 85% of the size of the single piece of the sheet member constituting the waist portion 20 (e.g., skin side pieces 31, 41), the shortest distance along the surface of the ventral waist portion 30 from one side joint 50A to the other side joint 50B at the lower end position of the ventral waist portion 30 is greater than the shortest distance along the surface of the back waist portion 40 from one side joint 50A to the other side joint 50B at the lower end position of the back waist portion 40.

[0097] With this configuration, when the leg opening LH is actually widened during the wearing action of diaper 1, the lower edge of the abdominal waist 30 is widened more than the lower edge of the back waist 40. Therefore, it is difficult for the wearer's toes to catch on the leg opening LH of the abdominal waist 30. Thus, it is easier and smoother to insert the leg into the leg opening LH, which is not easily visible.

[0098] In addition, the shortest distances (W30s, W40s) between the lateral joints 50, 50 of the abdominal waist 30 and the back waist 40 in the maximum elongation state (100% elongation state) and the 85% elongation state can be measured, for example, by the following method. Figure 8A and Figure 8B This is a diagram illustrating an example of a method for stretching diaper 1 in the left-right direction. When stretching diaper 1 in the left-right direction, a known tensile testing machine (e.g., the Instron Universal Testing Machine) can be used.

[0099] First of all, Figure 8A In the tensile testing machine 100, rod-shaped clamps 120A and 120B for supporting the diaper 1 are respectively installed on the upper and lower chucks 110. The distance L0 between clamps 120A and 120B is adjusted to be less than or equal to the left-right dimension of the waist portion 20 of the diaper 1 in its natural state. Next, the two ends of the waist portion 20 of the diaper 1 in the left-right direction are respectively hooked onto clamps 120A and 120B and fixed to prevent displacement. Preferably, anti-slip members (e.g., fish skin-like members) are provided on the surfaces of clamps 120A and 120B to prevent the diaper 1 from shifting.

[0100] After setting the diaper 1 on the tensile testing machine 100, as follows Figure 8BIn this manner, the stretching is performed at a specified speed (e.g., 100 mm / min) until the gap between clamps 120A and 120B reaches L1 (L1 > L0). After the gap reaches L1, the stretching is returned at a specified speed until the gap becomes L0 again. This action is repeated multiple times (e.g., twice). Furthermore, when the gap L1 is set to the maximum stretch state (100% stretch state) and the 85% stretch state, the shortest distances (W30s, W40s) between the lateral joints 50, 50 of the abdominal waist section 30 and the back waist section 40 are measured respectively.

[0101] Furthermore, preferably, when the waist section 20 is stretched to 85% of its full length, the lateral contraction force of the back waist section 40 is greater than that of the lateral contraction force of the abdominal waist section 30. Here, "contraction force" refers to the force exerted by the elastic member when it returns from its stretched state to its initial state. With this configuration, when the waist section 20 is expanded during the wearing action of the diaper 1, the abdominal waist section 30 expands more easily in the lateral direction compared to the back waist section 40, making it difficult for the wearer's toes to get caught on the abdominal waist section 30. Therefore, it is easier and smoother to insert the legs into the waist opening BH and leg opening LH of the diaper 1.

[0102] The lateral contraction force of the abdominal waist 30 and the back waist 40 can be used Figure 8A and Figure 8B The tensile testing machine 100 described herein is used for the measurement. For example, in the waist portion 20, a pair of side joints 50, 50 are peeled apart, and the absorbent body 10 is placed at the central position CL in the length direction (refer to...). Figure 2 The abdominal waist section 30 and the back waist section 40 are separated and used as samples for tensile testing. Furthermore, with the clamps 120A and 120B removed, the upper and lower chucks 110 and 110 are held at both ends of the sample (abdominal waist section 30 and back waist section 40) in the left and right directions, and stretched using the same method as described above until the distance between the upper and lower chucks 110 and 110 reaches 85% of the maximum elongation. The force at this point is measured. By performing this tensile test, the magnitude of the contraction force of the abdominal waist section 30 and the back waist section 40 can be compared.

[0103] Furthermore, preferably, when the abdominal waist circumference 30 is divided into four equal parts in the vertical direction, the lateral contraction force acting per unit length in the vertical direction within the lower 1 / 4 of the area is less than the lateral contraction force acting per unit length in the vertical direction within the upper 3 / 4 of the area. That is, as Figure 6In this case, if the area obtained by dividing the abdominal waist circumference 30 into four equal parts in the vertical direction is designated as 30A to 30D from the top, it can be set such that the lateral contraction force acting on each unit length of the vertical direction in the 30D area is less than the lateral contraction force acting on each unit length of the vertical direction in the 30A, 30B, and 30D areas.

[0104] The area 30D at the lower end of the abdominal waistband 30 is part of the leg opening LH when the diaper 1 is shaped like underwear. Therefore, if the lateral contraction force at this lower end weakens, the leg opening LH can be easily widened during the wearing action of the diaper 1. Thus, when a caregiver or other person puts the diaper 1 on an infant or other wearer with their hand already widened by inserting it into the leg opening LH, the abdominal (front) side of the leg opening LH can be easily widened. This prevents the wearer's toes from getting caught on the abdominal (front) side of the leg opening LH.

[0105] The lateral contraction force in each area (30A-30D) of the abdominal waist circumference 30 can be used Figure 8A and Figure 8B The tensile testing machine 100 is used to perform the test as follows: First, the abdominal waist portion 30 is separated from the back waist portion 40 and the absorbent body 10. Next, the abdominal waist portion 30 is cut along the left-right direction to divide it into regions 30D and 30A to 30C, which are then used as samples. Next, each sample is mounted on the tensile testing machine 100, and a tensile test is performed on each sample according to the above procedure to determine the shrinkage force.

[0106] Alternatively, it can be set such that the lateral contraction force acting per unit length in the vertical direction within the upper half of the waist portion 20 is less than the lateral contraction force acting per unit length in the vertical direction within the lower half of the waist portion 20. That is, it can also be set such that... Figure 6 The contractile force in the left-right direction of regions 30A and 30B of the abdominal waist portion 30 and the back waist portion 40, which act on each unit length of the region in the vertical direction, is less than the contractile force in the left-right direction of regions 30C and 30D of the abdominal waist portion 30 and the back waist portion 40, which act on each unit length of the region in the vertical direction.

[0107] In this configuration, the lateral contraction force in the upper half of the waistband 20 is weakened, making it easier to widen the waistband opening BH of the diaper 1. Therefore, when a caregiver or other person needs to put on the diaper 1 for an infant or other wearer, with the waistband opening BH already widened by inserting their hand through it, the waistband opening BH can be easily widened. This also makes it easier for the wearer's legs to enter the waistband opening BH.

[0108] The elasticity in the upper (30A, 30B) and lower (30C, 30D) areas of the waist circumference 20 can also be utilized. Figure 8A and Figure 8B The tensile testing machine 100 was used for the measurement. First, the absorbent body 10 was removed from the waist section 20, and the waist section 20 was cut off along the left and right directions at the center in the vertical direction to obtain samples. Next, it was compared with... Figure 8A and Figure 8B Similarly, by mounting each sample onto fixtures 120A and 120B respectively to perform a tensile test, the lateral contraction force in the upper and lower regions of the waist circumference 20 can be measured.

[0109] Furthermore, during the wearing of diaper 1, after the waistband 20 is expanded and the wearer's legs are inserted, the waistband 20 contracts to match the wearer's body. If the tightness created by the waistband 20 is too strong at this time, it may cause discomfort to the wearer. Therefore, in diaper 1, the tightness of the waistband 20 during the contraction process is reduced as much as possible to minimize discomfort to the wearer.

[0110] Figure 9 This is a graph showing the results of measuring the contractile force when the waistband 20 is expanded and the contractile force when the waistband 20 is contracted during actions such as putting on diaper 1. The contractile force was measured as follows: First, diaper 1 was prepared as the test subject, and a commercially available conventional underwear-type diaper was prepared as a comparative example. Furthermore, using... Figure 8A and Figure 8B The tensile testing machine 100 is used to perform tensile tests on diaper 1 and the comparative example diaper under specified test conditions.

[0111] As experimental conditions, according to Figure 8A and Figure 8BThe method described involves mounting the diaper 1 on a tensile testing machine 100 and performing a tensile test until the distance between clamps 120A and 120B changes from L0 = 140 mm to L1 = 290 mm. Here, the distance L1 = 345 mm when the waist portion 20 of the diaper 1 is stretched to its maximum elongation, and L1 = 290 mm is a size corresponding to the maximum size at which the waist portion 20 is expanded during the wearing action of the diaper 1 (i.e., the aforementioned 85% elongation state). Furthermore, during the stretching process until L1 becomes 290 mm (85% elongation state), the contraction force at which a predetermined size (e.g., 55%, 66%, and 77% of the maximum elongation state) is measured. Additionally, the size at which L1 reaches 77% of the maximum elongation state (77% elongation state) is the maximum size envisioned as the size for a wearer to wear the diaper 1. Similarly, the size at 55% (55% elongation) is the minimum size envisioned as the size when the wearer wears diaper 1, and 66% is the intermediate size between the maximum and minimum.

[0112] Next, the shrinkage force was measured when the waist portion 20 of the diaper 1 was contracted from L1 = 290 mm (85% elongation) to L0 (natural state) and L1 reached a specified size (e.g., 77%, 66%, and 55% of the maximum elongation). The same experiment was performed on a comparative example to measure the shrinkage force, and the results are shown below. Figure 9 .

[0113] according to Figure 9 It can be seen that, in the case of diaper 1 and either of the comparative examples, the contraction force when the waist portion 20 is contracted is less than the contraction force when the waist portion 20 is stretched and expanded.

[0114] On the other hand, regarding the magnitude of the contractile force, in the comparative example, the contractile force when the waistband is stretched to 85% is 9.65 N, while the contractile force when shrinking from 85% to 77% is 5.04 N. That is, in the comparative example of the panty-type diaper (conventional diaper), a tightening force equivalent to more than half the contractile force when the waistband is expanded during the wearing action acts on the wearer's waist.

[0115] In contrast, in the diaper 1 of this embodiment, the contraction force when the waistband 20 is stretched to 85% is 9.02 N, and the contraction force when it shrinks from 85% to 77% is 3.98 N. That is, it is known that in the diaper 1 of this embodiment, the tightening force acting on the wearer's waist is less than half of the contraction force when the waistband 20 is expanded during the wearing action. Furthermore, the contraction force (tightening force) itself is lower than that of the comparative example. This is because, by providing a low-elasticity area 61 on the ventral side (and a low-elasticity area 71 on the back) in the waistband 20 of the diaper 1, the tightening force when the waistband 20 contracts is weaker than in conventional products. Therefore, during the wearer's movements, even if the waistband 20 is expanded as much as possible to prevent the wearer's legs from getting caught, excessive tightening force can be suppressed when the waistband 20 contracts and matches the wearer's skin, making it less likely for the wearer to experience discomfort.

[0116] Additionally, in the abdominal waistband 30 of diaper 1, such as Figure 2 As shown, the width W61 of the lateral low-elasticity region 61 in the left-right direction is greater than the width W11 of the absorbent core 11 in the left-right direction (W61 > W11). Because the highly rigid absorbent core 11 is difficult to contract in the left-right direction, the lateral low-elasticity region 61 is also difficult to contract in the left-right direction in the portion overlapping with the absorbent core 11. Therefore, by setting the lateral low-elasticity region 61 within a range larger than that of the absorbent core 11 in the left-right direction, the lateral waist portion 30 as a whole is difficult to contract in the left-right direction. Consequently, between the pair of lateral joints 50, 50, the length of the lateral waist portion 30 in the left-right direction easily becomes longer than the length of the back waist portion 40 in the left-right direction, which can prevent the wearer's legs from getting caught on the lateral waist portion 30 during the wearing action of the diaper 1.

[0117] Furthermore, in the abdominal waist portion 30, the width W61 of the abdominal low stretchable area 61 in the left-right direction is greater than the sum of the widths W62 of the abdominal first stretchable areas 62 on both sides (2×W62) (W61>2×W62). Thus, if the proportion occupied by the abdominal low stretchable area 61 in the left-right direction of the abdominal waist portion 30 is greater than the proportion occupied by the abdominal first stretchable area 62, the portion of the abdominal waist portion 30 that reaches its maximum stretch state becomes larger. Therefore, the abdominal waist portion 30 easily expands in the left-right direction, making it easier to prevent the wearer's legs from getting caught on the abdominal waist portion 30 during the wearing of the diaper 1.

[0118] Additionally, in diaper 1 in its natural state, such as Figure 6As shown, the distance W61e between the outer end 61es of the low-elasticity ventral region 61 and the outer end 11es of the absorbent core 11 in the left-right direction is greater than the maximum width W62m of the first elastic ventral region 62 in the left-right direction (W61e > W62m). That is, in the ventral waistband 30 of the diaper 1, the region with low elasticity and high softness, namely the low-elasticity ventral region 61, is larger than the highly elastic first elastic ventral region 62. As a result, it is easier to open the ventral waistband 30 from its natural state.

[0119] In addition, such as Figure 4 As shown, in the left-right direction, the end 61es1 of one side of the low-elasticity abdominal region 61 is positioned closer to the starting point 15es1 of one side of the leak-proof wall portion 15, and the end 61es2 of the other side of the low-elasticity abdominal region 61 is positioned closer to the starting point 15es2 of the other side of the leak-proof wall portion 15. That is, in the abdominal waistband portion 30, the width W61 of the low-elasticity abdominal region 61 in the left-right direction is greater than the distance W15 between the starting points 15es and 15es of the leak-proof wall portion 15 in the left-right direction (W61 > W15). Therefore, when the diaper 1 is worn, the contraction force formed by the waistband elastic member 35 is difficult to act on the leak-proof wall portion 15, and the pair of leak-proof wall portions 15 will not bend or deform, and can easily maintain an upright state while maintaining the distance W15. As a result, the wearer is less likely to experience discomfort, and side leakage of excrement can be easily suppressed.

[0120] In addition, such as Figure 2 As shown, in the left-right direction, the end 61es1 of one side of the low-elasticity abdominal region 61 is positioned closer to the end 10es1 of one side of the absorbent body 10, and the end 61es2 of the other side of the low-elasticity abdominal region 61 is positioned closer to the end 10es2 of the absorbent body 10. That is, in the abdominal waistband 30, the width W61 of the low-elasticity abdominal region 61 in the left-right direction is greater than the width W10 of the absorbent body 10 in the left-right direction (W61 > W10). The two ends 10es1 and 10es2 of the absorbent body 10 in the left-right direction form part of the leg opening LH of the diaper 1, which is a part that can be easily pressed onto the groin area of ​​the wearer. Therefore, assuming that the waist elastic member 35 is arranged overlapping the two ends 10es1 and 10es2 in the left and right directions of the absorbent body 10, the waist elastic member 35 is easily pressed against the skin near the wearer's leg circumference, which may easily cause rubber band marks.

[0121] In contrast, in the diaper 1 of this embodiment, the two ends 10es1, 10es2 in the left and right directions of the absorbent body 10 and the area outside thereon are less likely to be subjected to the contractile force formed by the waist elastic member 35, and therefore, it is less likely to cause rubber band marks on the wearer's leg area.

[0122] However, the range in the left and right directions of the ventral low-twist region 61 can also be deformed as follows. Figure 10 This is a diagram showing a deformed example of the ventral low-twist region 61. Figure 10 This illustrates the scenario where diaper 1 is unfolded and set to its maximum elongation state, which is in contrast to... Figure 2 The corresponding diagram.

[0123] exist Figure 10 In a modified example, in the left-right direction, the end 61es1 of one side of the low-elasticity abdominal region 61 is positioned further to the other side than the end 10es1 of one side of the absorbent body 10 and further to the other side than the end 11es1 of one side of the absorbent core 11. Furthermore, the end 61es2 of the other side of the low-elasticity abdominal region 61 is positioned further to the other side than the end 10es2 of the other side of the absorbent body 10 and further to the other side than the end 11es1 of the other side of the absorbent core 11. In this case, since a portion of the abdominal waist elastic member 35 is arranged overlapping with the two ends of the absorbent body 10 in the left-right direction, the absorbent body 10 is pressed against the wearer's skin by the contractile force exhibited by the abdominal waist elastic member 35 at this overlapping portion. Therefore, it is less likely to cause elastic band marks on the wearer's leg area, and the fit of the absorbent body 10 is improved.

[0124] Furthermore, it is preferable that, in Figure 2 In the region between the outer end 10es (e.g., the end 10es2 on the other side in the left-right direction) of the absorbent main body 10 and the side joint 50 (the side joint 50 on the other side in the left-right direction), the width W61s of the abdominal low stretch region 61 in the left-right direction is smaller than the width W62 of the abdominal first stretch region 62 adjacent to the outer side of the abdominal low stretch region 61 in the left-right direction (W61s < W62). In the abdominal waist portion 30, because the abdominal low stretch region 61 is set large, the overall contractile force is weakened, and there is a possibility that the fit to the wearer's abdomen will be insufficient. Therefore, in the regions on both sides of the abdominal low stretch region 61 in the left-right direction, the abdominal first stretch region 62 is larger than the abdominal low stretch region 61, making it easier for the contractile force of the waist elastic member 35 to be applied. Therefore, compared to the case where the first stretchable area 62 on the abdomen is smaller than the low stretchable area 61 on the abdomen, it is less likely to cause elastic band marks on the wearer's abdomen, and it can suppress the deterioration of the fit of the waist circumference 30 on the abdomen.

[0125] On the other hand, the width W61s of the low-elasticity abdominal region 61 in the left-right direction can also be configured such that it is greater than the width W62s of the first abdominal elastic region 62 adjacent to the outer side of the low-elasticity abdominal region 61 in the left-right direction (W61s > W62s). With this configuration, the contractile force acting on the abdominal waist circumference 30 is smaller compared to the above-described case, thus making the absorbent body 10 more difficult to contract. Furthermore, the area where the contractile force formed by the waist elastic member 35 is less effective on both sides of the absorbent body 10 in the left-right direction becomes larger, thus reducing the likelihood of elastic band marks on the skin near the wearer's abdominal thighs.

[0126] In addition, preferably, such as Figure 2 As shown, the vertical length H61 of the low-elasticity abdominal region 61 is greater than the vertical length H63 of the second abdominal elastic region 63 adjacent to the upper side of the low-elasticity abdominal region 61 (H61 > H63). In other words, in the abdominal waist portion 30, the length of the portion where the low-elasticity abdominal region 61 is formed in the vertical direction (equivalent to H61) is greater than the length of the portion where the low-elasticity abdominal region 61 is not formed (equivalent to H63). As a result, the lateral contraction force formed by the waist elastic member 35 is weakened over a large area in the vertical direction of the abdominal waist portion 30, making it difficult for the absorbent core 11 to contract, and also making it less likely to cause elastic band marks on the wearer's skin.

[0127] On the other hand, it can also be with Figure 2 In contrast to the case shown, the length H61 of the abdominal low-elasticity region 61 in the vertical direction is set to be less than or equal to the length H63 of the abdominal second elasticity region 63 in the vertical direction (H61≤H63). In other words, it can also be set such that the length of the portion of the abdominal waistband 30 in which the abdominal low-elasticity region 61 is formed in the vertical direction (equivalent to H61) is less than or equal to the length of the portion in which the abdominal low-elasticity region 61 is not formed (equivalent to H63). With such a configuration, the contractile force of the waist elastic member 35 acting on the abdominal waistband 30 can be increased compared to the case where H61 is greater than H63. For example, in cases where the diaper size is large, or where it is undesirable to reduce the fit at the wearer's waist, it is preferable that the abdominal waistband 30 has a certain degree of elasticity. Therefore, in such cases, by adjusting H61≤H63, positional shift and reduced fit when wearing the diaper 1 can be suppressed.

[0128] Alternatively, a back-feeding band 90 can be provided on the non-skin side of the waistband 40 on the back of the diaper 1 (see reference). Figure 2 as well as Figure 3The post-processing belt 90 is a strip-shaped belt member used when discarding the diaper 1. For example, after rolling up the used diaper 1 from the crotch side to the waist opening side, the post-processing belt 90 is used to fix it in a rolled-up state, thereby maintaining the diaper 1 in a compact shape for disposal. When the contraction force in the left-right direction of the abdominal waist portion 30 is less than the contraction force in the left-right direction of the back waist portion 40, when the used diaper 1 is rolled up with the back waist portion 40 on the outside (i.e., the abdominal waist portion 30 on the inside), the volume of the rolled-up diaper 1 can be reduced by contracting the outer back waist portion 40. Furthermore, by fixing the rolled-up diaper 1 in this way by the post-processing belt 90 provided on the back waist portion 40, the diaper 1 can be disposed of in a more compact shape, improving the convenience for the user.

[0129] Furthermore, preferably, in the vertical direction, the average stress of the waist elastic member 45 disposed in region H61 of the back waist portion 40 is greater than the average stress of the waist elastic member 45 disposed in region H63 of the back waist portion 40. Since a low-elasticity abdominal region 61 is provided in region H61 of the abdominal waist portion 30, the contractile force generated by the abdominal waist portion 30 is smaller compared to region H63. That is, the contractile force of the abdominal waist portion 30 in region H61 is weak, making it prone to collapsing off the wearer's body.

[0130] Therefore, the area corresponding to H61 of the back waist portion 40 and the ventral waist portion 30 has a stronger contractile force than the area corresponding to H63. Thus, in the H61 area, the ventral waist portion 30 is easily stretched laterally by the back waist portion 40, which helps to suppress the overall reduction in contractile force. Therefore, when wearing the diaper 1, the ventral waist portion 30 and the back waist portion 40 can be prevented from sagging off the wearer's body.

[0131] Furthermore, more preferably, the average stress of the waist elastic member 45 in region H61u, which is located above the center in the vertical direction within region H61 of the back waist portion 40, is greater than the average stress of the waist elastic member 45 in region H61d, which is located below the center in the vertical direction within region H61 of region H61. Since the lower vertical region within region H61 of the back waist portion 40 is close to the leg opening LH, by making the stress in this region weaker than that in the upper vertical region within region H61, excessive tightening force is less likely to act on the wearer's leg opening, thus reducing discomfort when wearing the diaper 1. In this embodiment, since the back low-elasticity region 71 is provided in a manner that partially overlaps with region H61d of the back waist portion 40, the stress of the waist elastic member 45 is reduced more easily in region H61d compared to region H61u.

[0132] ===Other Implementation Methods===

[0133] The embodiments of the present invention have been described above. However, the above embodiments are configurations designed to facilitate understanding of the present invention and are not intended to limit the interpretation of the invention. Furthermore, the present invention can be modified and improved without departing from its concept, and the present invention naturally includes equivalent configurations.

[0134] In diaper 1, the areas of the abdominal waistband 30 and the back waistband 40 can be adjusted such that their area ratio is within a specified range. For example, it is preferable that the area of ​​the abdominal waistband 30 is in the range of 30 to 50, and the area of ​​the back waistband 40 is in the range of 50 to 70. More preferably, the area ratio of the abdominal waistband 30 to the back waistband 40 is set to 35:65. By setting the area of ​​the back waistband 40 to be larger than that of the abdominal waistband 30, even in cases where the stress on the back waistband 40 is high, the tightening pressure will be reduced, making it less likely for the wearer to experience discomfort.

[0135] Explanation of reference numerals in the attached figures

[0136] 1 diaper (disposable diaper in underwear style),

[0137] 10 Absorbent Subjects

[0138] 11 absorbent core, 11b core-coated sheet,

[0139] 12 films,

[0140] 13 film, 13a liquid-proof film, 13b outer packaging film.

[0141] 15 Leak-proof wall section, 16 Leak-proof wall elastic component, 17 Leg retaining elastic component,

[0142] 20 waist area

[0143] 23 Main body joint, 24 Main body joint,

[0144] 30 Abdominal waist circumference, 30sw side circumference,

[0145] 31 skin side images,

[0146] 32 non-skin side panels, 32F folded-back section.

[0147] 35. Waist elastic component (abdominal waist elastic component)

[0148] 35s continuous elastic member, 35c discontinuous elastic member.

[0149] 36 skin slices

[0150] 40 Back and side waist area,

[0151] 40b hip bra, 40sw side bra.

[0152] 41 Skin side view, 42 Non-skin side view, 42f Folded-back section

[0153] 45. Waist elastic component (back side waist elastic component)

[0154] 45s continuous elastic member, 45c discontinuous elastic member.

[0155] 50 lateral joint, 50A and 50B lateral joints,

[0156] 61. Ventral low-extension region (discontinuous part)

[0157] 62. Ventral first stretching region, 63. Ventral second stretching region.

[0158] 71. Low-twist area on the dorsal side (discontinuous part),

[0159] 81. First retractable area on the dorsal side; 82. Second retractable area on the dorsal side.

[0160] Post-90s processing tape,

[0161] 100 Tensile Testing Machine

[0162] 110 chuck,

[0163] 120A and 120B fixtures

[0164] 150 calipers

[0165] BH waist opening, LH leg opening

[0166] CL central position (longitudinal and length direction).

Claims

1. A disposable diaper in the form of underwear, wherein the disposable diaper has intersecting vertical, horizontal, and front-back directions. The aforementioned disposable underwear-type diaper has an absorbent main body with liquid absorption and a waistband that can stretch in the aforementioned left and right directions, characterized in that... The aforementioned absorbent body has an absorbent core. The aforementioned waist section includes an abdominal waist section and a back waist section. The aforementioned ventral waist section and the aforementioned back waist section do not have a through hole in the aforementioned front-to-back direction. The aforementioned abdominal waist portion and the aforementioned back waist portion are connected in a ring shape by a pair of lateral joints. Under natural conditions, At a certain position in the vertical direction, The shortest distance along the surface of the abdominal waist region from one side joint to the other side joint is greater than the shortest distance along the surface of the dorsal waist region from one side joint to the other side joint. The aforementioned back waist section has a skin-side panel disposed on the skin side and a non-skin-side panel laminated in a manner adjacent to the non-skin side of the aforementioned skin-side panel. The upper part of the aforementioned skin side panel on the back waist area was not folded back. The aforementioned non-skin side panel of the back waistband has a folded portion at its upper end that folds back from the non-skin side to the skin side and from the upper side to the lower side. The lower end of the aforementioned folded-back section is located above the upper end of the aforementioned absorbent main body. The aforementioned waist section includes a discontinuous elastic member having a discontinuous portion in the aforementioned left-right direction. The aforementioned discontinuous elastic member has a portion located on one side of the discontinuous portion in the left-right direction and a portion located on the other side of the discontinuous portion in the left-right direction. The aforementioned one-sided portion and the aforementioned other-sided portion are positioned at the same location in the aforementioned vertical direction. In the aforementioned left-right direction, the inner end of one side portion and the inner end of the other side portion are located on the outer side of the absorbent core.

2. The disposable diaper in the underwear type as described in claim 1, characterized in that, When the waist section is extended in the aforementioned left-right direction until it becomes 85% of the single-unit size of the sheet member constituting the waist section, At a certain position in the aforementioned vertical direction, The shortest distance along the surface of the abdominal waist region from the side joint of one of the aforementioned parties to the side joint of the other party is greater than the shortest distance along the surface of the dorsal waist region from the side joint of one of the aforementioned parties to the side joint of the other party.

3. The disposable diaper in the underwear type as described in claim 2, characterized in that, At the lower end of the waist section in the above vertical direction, The shortest distance along the surface of the abdominal waist region from the side joint of one of the aforementioned parties to the side joint of the other party is greater than the shortest distance along the surface of the dorsal waist region from the side joint of one of the aforementioned parties to the side joint of the other party.

4. The disposable diaper of the underwear type as described in claim 2 or 3, characterized in that, The contraction force in the left-right direction of the back waist section is greater than the contraction force in the left-right direction of the abdominal waist section.

5. A disposable diaper in the form of underwear, wherein the disposable diaper has intersecting vertical, horizontal, and front-back directions. The aforementioned disposable underwear-type diaper has an absorbent main body with liquid absorption and a waistband that can stretch in the aforementioned left and right directions, characterized in that... The aforementioned absorbent body has an absorbent core. The aforementioned waist section includes an abdominal waist section and a back waist section. The aforementioned ventral waist section and the aforementioned back waist section do not have a through hole in the aforementioned front-to-back direction. The aforementioned abdominal waist portion and the aforementioned back waist portion are connected in a ring shape by a pair of lateral joints. Under natural conditions, At a certain position in the vertical direction, The shortest distance along the surface of the abdominal waist region from one side joint to the other side joint is greater than the shortest distance along the surface of the dorsal waist region from one side joint to the other side joint. The aforementioned waist section includes a discontinuous elastic member having a discontinuous portion in the aforementioned left-right direction. The aforementioned discontinuous elastic member has a portion located on one side of the discontinuous portion in the left-right direction and a portion located on the other side of the discontinuous portion in the left-right direction. The aforementioned one-sided portion and the aforementioned other-sided portion are positioned at the same location in the aforementioned vertical direction. In the aforementioned left-right direction, the inner ends of both the aforementioned one-sided portion and the aforementioned other-sided portion are located on the outer side of the absorbent core. The contractile force in the left-right direction acting on a unit length area in the vertical direction within a 1 / 4 range from the bottom side of the aforementioned abdominal waist portion is less than the contractile force in the left-right direction acting on a unit length area in the vertical direction within a 3 / 4 range from the top side of the aforementioned abdominal waist portion.

6. A disposable diaper in the form of underwear, wherein the disposable diaper has intersecting vertical, horizontal, and front-back directions. The aforementioned disposable underwear-type diaper has an absorbent main body with liquid absorption and a waistband that can stretch in the aforementioned left and right directions, characterized in that... The aforementioned waist section includes an abdominal waist section and a back waist section. The aforementioned ventral waist section and the aforementioned back waist section do not have a through hole in the aforementioned front-to-back direction. The aforementioned abdominal waist portion and the aforementioned back waist portion are connected in a ring shape by a pair of lateral joints. Under natural conditions, At a certain position in the vertical direction, The shortest distance along the surface of the abdominal waist region from one side joint to the other side joint is greater than the shortest distance along the surface of the dorsal waist region from one side joint to the other side joint. The aforementioned back waist section has a skin-side panel disposed on the skin side and a non-skin-side panel laminated in a manner adjacent to the non-skin side of the aforementioned skin-side panel. The upper part of the aforementioned skin side panel on the back waist area was not folded back. The aforementioned non-skin side panel of the back waistband has a folded portion at its upper end that folds back from the non-skin side to the skin side and from the upper side to the lower side. The lower end of the aforementioned folded-back section is located above the upper end of the aforementioned absorbent main body. The contractile force in the left-right direction acting on the area per unit length in the vertical direction within the upper half of the waist portion is less than the contractile force in the left-right direction acting on the area per unit length in the vertical direction within the lower half of the waist portion.

7. The disposable diaper of the underwear type as described in any one of claims 1, 5, and 6, characterized in that, The shrinkage force when the waist portion is stretched in the left-right direction until it becomes 85% of the size of the single piece of the sheet member constituting the waist portion is more than twice the shrinkage force when the waist portion is contracted in the left-right direction until it changes from 85% to 77% of the size of the single piece of the sheet member constituting the waist portion.

8. The disposable diaper of the underwear type as described in any one of claims 1, 5, and 6, characterized in that, The aforementioned ventral waist region has a low-elasticity ventral area where the contraction force in the left-right direction is lower than that of other regions. The width of the aforementioned ventral low-extension region in the left-right direction is greater than the width of the absorbent core provided in the aforementioned absorbent body in the left-right direction.

9. The disposable diaper of the underwear type as described in claim 8, characterized in that, The aforementioned abdominal waist portion has a first abdominal stretching region that is adjacent to both sides of the aforementioned abdominal low stretching region in the left-right direction and whose contraction force in the left-right direction is greater than that of the aforementioned abdominal low stretching region. The width of the aforementioned ventral low-extension region in the left-right direction is greater than the sum of the widths of the aforementioned ventral first extension region in the left-right direction.

10. The disposable diaper in the underwear type as described in claim 9, characterized in that, In the natural state of the aforementioned abdominal waist area, The distance between the outer end of the absorbent core in the left-right direction and the inner end of the first ventral stretching region is greater than the width of the first ventral stretching region in the left-right direction.

Images